Japanese submarine I-363

I-363 was an Imperial Japanese Navy Type D1 transport submarine. Completed and commissioned in July 1944, she served in World War II and conducted transport missions between Japan and outlying islands until she was converted into a "kaiten" suicide attack torpedo carrier. She survived the war, but sank after striking a mine in the weeks immediately following its conclusion.
Construction and commissioning.
"I-363" was laid down on 1 May 1943 by Kure Navy Yard at Kure, Japan, with the name Submarine No. 5463. She was renamed I-363 on 20 October 1943 and provisionally attached to the Yokosuka Naval District that day. She was launched on 12 December 1943 and was completed and commissioned on 8 July 1944.
Service history.
Upon commissioning, "I-363" was attached formally to the Yokosuka Naval District and was assigned to Submarine Squadron 11 for workups. She departed Hikari on 8 August 1944. With her workups complete, she was reassigned to Submarine Squadron 7 on 15 September 1944.
Transport missions.
On 9 October 1944, "I-363" departed Yokosuka bound for Mereyon Island at Woleai in the Caroline Islands on her first transport mission, carrying 75 metric tons of food and supplies and 15 metric tons of other cargo. En route, he stopped at Truk from 21 to 24 October 1944, where she picked up another 10 metric tons of cargo for Mereyon consisting of food and uniforms. She arrived at Mereyon on 28 October 1944, unloaded five tons of fuel and supplies, embarked seven passengers, and got back underway the same day. She returned to Truk on 31 October 1944, unloaded 33 metric tons of fuel oil, embarked 83 Imperial Japanese Navy Air Service personnel, and put back to sea on 2 November 1944 bound for Yokosuka, which she reached on 15 November 1944. She got underway from Yokosuka on 30 November 1944 for a training exercise, but returned the same day after her commanding officer suffered an injury.
"I-363" departed Yokosuka on 10 November 1944 for her second transport voyage carrying a cargo of 88 metric tons of food, 10 metric tons of ammunition, and 10 metric tons of other supplies, this time setting course for Marcus Island, which she reached on 17 November 1944. After unloading her cargo and embarking 60 passengers, she left the same day bound for Yokosuka, where she arrived on 26 December 1944. She then began an overhaul.
With the overhaul complete, "I-363" put to sea from Yokosuka on 5 March 1945 for her third supply voyage, again bound for Marcus Island. She arrived at Marcus on 13 March 1945, unloaded her cargo, and headed back to Yokosuka. During her voyage, Submarine Squadron 7 was deactivated on 20 March 1945 and she was reassigned to Submarine Division 15. She reached Yokosuka on 30 March 1945.
"Kaiten" carrier.
While "I-363" was on her return voyage from Marcus Island, U.S. forces captured advanced bases and anchorages in the Kerama Islands southwest of Okinawa between 26 and 29 March 1945, and shortly after her arrival at Yokosuka, the Battle of Okinawa began when U.S. forces landed on Okinawa itself on 1 April 1945. After reaching Yokosuka, "I-363" was converted from a transport submarine into a "kaiten" suicide attack torpedo carrier, the conversion involving the removal of her deck gun and "Daihatsu"-class landing craft and their replacement with fittings allowing her to carry five "kaitens" on her deck,
First "kaiten" mission.
By 28 May 1945, "I-363" was part of the "Todoroki" ("Thunderclap") "Kaiten" Group along with the submarines , , and . With five "kaitens" on board, she got underway from the "kaiten" base at Hikari that day bound for a patrol area between Okinawa and Ulithi Atoll.
On 15 June 1945, "I-363" sighted a convoy southeast of Okinawa. With the seas too rough for her to launch her "kaitens", she attacked with conventional torpedoes instead. Her commanding officer believed she sank one merchant ship, although in fact she inflicted no damage. On 18 June, she received orders to end her patrol and proceed to Hirao, Japan, which she reached on 28 June 1945. She moved on to Kure on 29 June 1945.
Second "kaiten" mission.
Assigned to the "Tamon" "Kaiten" Group along with the submarines , , , , and , "I-363" departed Hikari on 8 August 1945, the last of the group′s submarines to get underway. She was assigned a patrol area north of Palau, but on 12 August 1945 received orders to instead patrol in the Sea of Japan to defend the Japanese archipelago against a possible Soviet invasion. She was on the surface northwest of Kyushu on 14 August 1945 when aircraft of United States Navy Task Force 38 strafed her, killing two members of her crew but inflicting only minor damage on her.
End of war.
On 15 August 1945, while "I-363" was at sea, World War II ended with Emperor Hirohito′s "Jewel Voice Broadcast" announcing the cessation of hostilities between Japan and the Allies. "I-363" arrived at Kure on 18 August 1945 and surrendered to the Allies on 2 September 1945, the same day that Japan formally surrendered in a ceremony aboard the battleship in Tokyo Bay.
Loss.
On 27 October 1945, "I-363" got underway from Kure bound for Sasebo. She was off the coast of Miyazaki Prefecture on 29 October 1945 when she struck a mine that had been laid during World War II. She sank with the loss of 36 lives. There were 10 survivors. She was stricken from the Navy list on 10 November 1945.
Final disposition.
The Fukada Salvage Company refloated "I-363"′s wreck on 26 January 1966. The wreck was scrapped at Etajima.
Commemoration.
"I-363"′s periscope is on display at the "I-363" memorial at the Nagasako Cemetery, a former Imperial Japanese Navy cemetery at Kure.


Bukit Batok West MRT station

Bukit Batok West MRT station is a proposed Mass Rapid Transit (MRT) station on the Jurong Region Line located along the boundary of Bukit Batok and Jurong East planning areas, Singapore.
History.
On 9 May 2018, LTA announced that Bukit Batok West station would be part of the proposed Jurong Region line (JRL). The station will be constructed as part of Phase 2, JRL (East), consisting of 7 stations between Tengah and Pandan Reservoir, and is expected to be completed in 2028.
Contract J108 for the design and construction of Bukit Batok West Station and associated viaducts was awarded to John Holland Pty Ltd – McConnell Dowell South East Asia Pte Ltd Joint Venture (JV) at a sum of S$265.4 million in March 2020. Construction will start in 2020, with completion in 2028. Contract J108 also includes the design and construction of Tengah Plantation Station and Tengah Park Station, and associated viaducts.
Initially expected to open in 2027, the restrictions on the construction due to the COVID-19 pandemic has led to delays in the JRL line completion, and the date was pushed to 2028.
Location.
The station complex will be situated next to the PIE slip road at the junction with Bukit Batok Road and Jurong Town Hall Road. It is located in the Bukit Batok planning area in Bukit Batok West Subzone, parallel to the PIE, surrounded by housing estate to the north and south.
Access to the station will be via 5 exits located either side of the PIE.


Akeytsu

Akeytsu is a 3D animation and rigging software focused on the game development market. It was built to create large volumes of 3D animation with simple tools.
History.
Akeytsu is developed by the company Nukeygara, which was co-founded in 2014 in Lyon, France by Aurélien Charrier. He is an animator with 12 years experience in the video game industry. His aim with Akeytsu was to build a feature set that was intuitive and easy to use. The beta version was found to be a simple focused tool concentrated on animation. Akeytsu was launched on Steam engine in 2016.


No 6 mine

The No 6 mine is an Israeli metal-cased anti-tank blast mine. It is a direct copy of the Russian TM-46 mine, the only notable difference being the filling cap, which is domed on the TM-46 and flat on the No 6. It can be fitted with the No 61 pressure fuze or a No 62A tilt rod fuze. The mine is found in the Falkland Islands, Israel, Lebanon and Oman.


Argent Ventures

Argent Ventures, LLC. is a privately held real estate company based in New York City that most notably owned the land under Grand Central Terminal and the land around of Metro-North Railroad railway tracks in the New York City metropolitan area from 1994 to 2018.
Properties.
Among other high-profile buildings currently owned are:
The company was spun off in 1996 by Andrew Penson from Amroc Investments, which specializes in turning around distressed properties.
Two of its earlier properties that have since been sold included:
Metro-North assets.
In the breakup of the Penn Central Railroad in 1976, the land under Midtown Manhattan's Grand Central Terminal and its associated tracks continued to be owned by Penn Central Corporation but leased to the Metropolitan Transportation Authority's Metro-North Railroad. The railroad's Hudson Line and Harlem Line was also owned by the Penn Central holding company and leased to Metro-North. Penn Central as a holding company changed its name to American Premier Underwriters in March 1994. It in turn was absorbed by the American Financial Group.
On December 6, 2006, the United States Department of Transportation announced Midtown TDR Ventures LLC had purchased the rights from American Financial. As part of the transaction the lease with the MTA was renegotiated through February 28, 2274.
The New York Post reported in 2007 that Midtown TDR was controlled by Penson and Venture. The Post noted that the MTA would pay $2.24 million in rent in 2007, but had an option to buy the station and tracks in 2017, although Argent was able to extend the option date another 15 years to 2032. Venture had desired the air rights for possible future development above the tracks. At the time, Argent still owned the Hudson Line and most of the Harlem Line, except for the section of track north of Dover Plains on the Harlem Line, which was owned by the MTA.
In November 2018, the MTA proposed purchasing the Hudson and Harlem Lines as well as the Grand Central Terminal for up to $35.065 million, plus a discount rate of 6.25%. The purchase would include all inventory, operations, improvements, and maintenance associated with each asset, except for the air rights over Grand Central. At the time, the Hudson and Harlem Lines were owned by the Penn Central holding company, while the Grand Central Terminal was owned by Midtown TDR Ventures. Under the terms of the leases for each asset, the MTA would only be able to exercise an option to purchase the three assets before October 2019.
The MTA wanted to purchase the assets in order to avoid future double-payments on its existing leases for these assets. If the option were exercised, the closing of the sale was not proposed to occur until at least April 2020. The MTA's finance committee approved the proposed purchase on November 13, 2018, and the purchase was approved by the full board two days later. Under the terms of the deal, the MTA purchased Grand Central Terminal, as well as the Hudson Line from Grand Central to a point north of Poughkeepsie, and the Harlem Line from Grand Central to Dover Plains.
Acquisition.
In July 2019, Argent Ventures has taken over Princeton 's University Square office building from RXR Realty and The Blackstone Group.


Cable harness

A cable harness, also known as a wire harness, wiring harness, cable assembly, wiring assembly or wiring loom, is an assembly of electrical cables or wires which transmit signals or electrical power. The cables are bound together by a durable material such as rubber, vinyl, electrical tape, conduit, a weave of extruded string, or a combination thereof.
Commonly used in automobiles, as well as construction machinery, cable harnesses provide several advantages over loose wires and cables. For example, many aircraft, automobiles and spacecraft contain many masses of wires which would stretch over several kilometers if fully extended. By binding the many wires and cables into a cable harness, the wires and cables can be better secured against the adverse effects of vibrations, abrasions, and moisture. By constricting the wires into a non-flexing bundle, usage of space is optimized, and the risk of a short is decreased. Since the installer has only one harness to install (as opposed to multiple wires), installation time is decreased and the process can be easily standardized. Binding the wires into a flame retardant sleeve also lowers the risk of electrical fires.
Production.
Cable harnesses are usually designed according to geometric and electrical requirements. A diagram is then provided (either on paper or on a monitor) for the assembly preparation and assembly.
The wires are first cut to the desired length, usually using a special wire-cutting machine. The wires may also be printed on by a special machine during the cutting process or on a separate machine. After this, the ends of the wires are stripped to expose the metal (or "core") of the wires, which are fitted with any required terminals or connector housings. The cables are assembled and clamped together on a special workbench, or onto a pin board ("assembly board"), according to the design specification, to form the cable harness. After fitting any protective sleeves, conduit, or extruded yarn, the harness is either fitted directly in the vehicle or shipped.
In spite of increasing automation, hand manufacture continues to be the primary method of cable harness production in general, due to the many different processes involved, such as:
It is difficult to automate these processes, with major suppliers still using manual means of production, only automating portions of the process. Manual production remains more cost effective than automation, especially with small batch sizes.
Pre-production can be automated in part. This affects:
A wire harness must also be manufactured with a terminal, defined as "a device designed to terminate a conductor that is to be affixed to a post, stud, chassis, another tongue, etc., to establish an electrical connection." Some types of terminals include ring, tongue, spade, flag, hook, blade, quick-connect, offset and flagged.
Once a cable harness has been produced, it is often subject to various tests to ensure its quality and functionality. A test board can be used to measure the harness' electrical capabilities. This is achieved through the input of data about a circuit which one or more cable harnesses will be part of being programmed into the test board. The harness is then measured for its ability to function in the simulated circuit.
Another popular test method for a cable harness is a 'pull test', in which the harness is attached to a machine that pulls the harness at a constant rate. This test then measures the cable harness' strength and electrical conductivity when pulled against a minimum standard to ensure that cable harnesses are consistently effective and safe.
In sound engineering.
The cable harnesses used in sound reinforcement and recording studios are called "multicores", also known as "snakes" or "looms". They carry audio signals between a mixing console and stage box. Modern digital mixing consoles typically use a single twisted pair cable rather than a traditional analog multicore.
Industry quality standard.
Although customer specifications take the highest priority when creating cable harnesses of a certain quality, in North America if no such specifications are found the quality standards of a cable harness are standardized by the IPC's publication IPC/WHMA-A-620 for minimal requirements for cable harnesses. This publication is reviewed frequently to ensure that the standards published remain of an acceptable standard in light of potential changes to the industry or technology that may occur. The IPC/WHMA-A-620 publication has standards for a wide range of elements within a cable harness, including but not limited to electrostatic discharge protection, conduit, installation and repairs, crimping, pull-test requirements, and other operations that are critical to the production and function of cable harnesses. The standards mandated by the IPC differ based on a product's classification under one of three defined product classes. These classes are:


Julie Katzman

Julie Katzman (born December 6, 1961) is the Executive Vice-President and Chief Operating Officer of the Inter-American Development Bank.
Early career.
After starting her career in Chicago and London, Katzman joined Lehman Brothers in New York in their high yield finance group where she worked on many high-profile M&A transactions in the late 1980s and the 1990s. She then moved to Lehman's private equity group where she was part of Lehman's extraordinarily successful first externally raised fund of $1.25 billion which had returns of over 35%, making investments in industries ranging from media to consumer products to defense. Katzman's experience as a director began while at Lehman Brothers, when, after leading Computervision Corporation's restructuring in 1992, she joined their board of directors. She also served as a member of Computervision's audit committee. She later joined the boards of Loral Aerospace and Space Systems/Loral, serving on the audit committee, after the Lehman Fund and Loral Corporation completed the acquisition of The Ford Motor Company's $1.9 billion defense business. Katzman left Lehman as one of the firm's youngest Managing Directors.
After leaving Lehman Brothers, she was a co-founder and partner of Violy, Byorum & Partners, a Latin America focused investment banking and strategic advisory firm that was consistently ranked as one of the top 10 M&A advisors in that region. While at VB&P, Katzman advised a number of the region's most influential business groups across a broad range of industries.
In government.
At the Inter-American Development Bank, Katzman is Chief Operating Officer and manages the overall operations of the Bank, with over 4,000 staff and consultants and 29 offices.
Non-profit work.
Katzman currently serves on the board of directors of the MacArthur Foundation, one of the 10 largest foundations in the United States with over $6 billion in assets. She is the chairperson of the audit committee and is a member of foundation's investment and institutional policy (governance) committees. Katzman also serves on other not for profit boards of directors including the Advisory Council of MIT Media Lab.


Riefler escapement

The Riefler escapement is a mechanical escapement for precision pendulum clocks invented and patented by German instrument maker Sigmund Riefler in 1889. It was used in the astronomical regulator clocks made by his German firm Clemens Riefler from 1890 to 1965, which were perhaps the most accurate all-mechanical pendulum clocks made.
An escapement is the mechanism in a mechanical clock that gives the pendulum precise impulses to keep it swinging, and allows the gear train to advance a set amount with each pendulum swing, moving the clock hands forward at a steady rate. The Riefler escapement was an improvement of the deadbeat escapement, the previous standard for precision clocks. In the deadbeat, the force to keep the pendulum swinging is applied by the teeth of the escape wheel sliding alternately against two angled pallets on arms attached to the pendulum. Therefore, slight variations in the friction of the pallets and in the torque from the escape wheel are passed on to the pendulum, disturbing its motion.
How it works.
In the Riefler escapement, the energy required to keep the pendulum swinging is instead supplied by bending the short straight spring strip which suspends the pendulum. The upper end of the suspension spring is not attached to a fixed support as in most clocks, but instead is attached to a heavy metal bearer, which pivots on two aligned knife-edges on its underside which rest on flat agate plates. The bending point of the suspension spring is in alignment with the line of contact of the knife-edges. When the pendulum passes its bottom point, the escape wheel is unlocked and pushes the bearer, and the bearer pivots suddenly on its knife edges by a small angle, flexing the spring. The spring is bent by a small amount in addition to that caused by the swing of the pendulum, and thus provides the impulse for the next swing. So the suspension spring is used for two functions: suspending the pendulum and giving it impulse.
The escapement has better performance than the deadbeat because the force from the pallets, with its variability, is applied not to the pendulum but to the bearer. The escapement has no contact with the pendulum below the suspension spring. The pendulum is free of disturbance from the escape wheel for most of each swing and the only work it has to do is to unlock the escape wheel once per second. This operation is performed near the ideal place, at the center of each swing.
The Riefler escape wheel and pallets are of a special design. There are actually two escape wheels mounted on the same shaft and two surfaces on each of the two pallet pins. The front locking wheel has forward pointing teeth rather like a dead-beat escapement, and catches on the flat surface of the pallet to lock the wheel. The rear impulse wheel has teeth with a sloping surface facing the direction of rotation. The round part of each pallet is acted upon by this surface to give the impulse.
Riefler clocks.
Clemens Riefler precision regulator clocks achieved accuracies of 10 milliseconds per day, and were guaranteed to be within 30 milliseconds. With over 600 made, they were one of the most widely used astronomical regulators, and became the highest standard for timekeeping in the early 20th century. They were used worldwide in astronomical observatories, naval observatories, and as primary standards for electrical time dissemination services, which delivered time signals by telegraph wire. Riefler clocks had internal switch contacts for this purpose, which delivered a 1 Hz time signal to external equipment. The first time standard for the United States, provided by the Bureau of Standards (now NIST), was from 1904 to 1929 generated by Riefler clocks.
In addition to the Riefler escapement, Riefler clocks' mechanism had several other innovations which were responsible for their accuracy. They were one of the first clocks to use a pendulum rod made of the low thermal expansion alloy invar, to prevent the pendulum from changing length with temperature changes, causing error. The most accurate models were mounted in a low pressure tank to eliminate the effect of changes in atmospheric pressure on the pendulum. They were powered by a gravity remontoire, a small weight which was wound up by an electric motor every 30 seconds, to eliminate the effect of changes in drive force on the mechanism.
Working Riefler precision pendulum clocks on display to the public are located at the Deutsches Museum in Munich, the National Watch and Clock Museum in Columbia PA, the Musée international d'horlogerie in La Chaux-de-Fonds and the Musée d'horlogerie in Le Locle (both in Switzerland), the Deutsches Uhrenmuseum in Furtwangen, and at the US Naval Observatory (by appointment only) in Washington DC. The clock at Carleton College in Northfield, MN is currently not on display, awaiting the completion of a new display space in Anderson Hall.


Lajos Tisza

Count Lajos Tisza de Borosjenő et Szeged (12 September 1832 - 26 January 1898) was a Hungarian politician, who served as Minister besides the King between 1892 and 1894. He was the younger brother of Kálmán Tisza and uncle of István Tisza. Tisza took part in the Hungarian politics from 1861, he was a supporter of the Austro-Hungarian Compromise of 1867. After the great flood at Szeged in 1879 he was the responsible for the reconstruction of the town. Szeged regards him as a hero since then because Lajos Tisza conducted the performance of the complicated task of the town's reconstruction with distinguished cooperation and a good organizational skill. Lajos Tisza received the title of Count from Emperor Franz Joseph for his works in the reconstruction of Szeged in 1883. However, the childless Lajos Tisza conferred his title on his politician nephew Stephen Tisza with the consent of the Monarch on 16 February 1897.
Until his death he was the chairman of the National Association of Forestry. On Szeged the Lajos Tisza Boulevard and the Széchenyi Square's sculpture cherishes his memory. The sculpture prepared by János Fadrusz in 1904, who said this about his masterpiece: "I will characterize junior Hungary, today's Hungary with this sculpture, not only Lajos Tisza. The heroes of the work are today's Hungary's heroes. That's why symbolic is the town of Szeged's story, our good king and our nation dared resolute and not slackened was reborne with his work."


Ragnvald Einbu

Ragnvald Pedersson Einbu (January 10, 1870 – July 4, 1943) was a Norwegian woodcarver and painter.
Einbu was born in Lesja, the son of Peder Johannesson Einbu and Marit Syversdotter Enebo. He was the brother of astronomer Sigurd Einbu (1866–1946). In 1915 he married Berta Marie Martinusdatter (1888–1974).
Einbu is known principally for having decorated church interiors in several places in Norway and for a wide range of decoration tasks in public buildings and private homes. In 1896, he attended the Norwegian National Academy of Craft and Art Industry. He subsequently came in contact with Anders Sandvig at Maihaugen and worked with the decorations in connection with the restoration of the Isum Chapel ("Isum kapell") from Sør-Fron which was completed in 1910.
Einbu died in Lesja.


Yi Xing

Yi Xing (, 683–727), born Zhang Sui (), was a Chinese astronomer, mathematician, inventor, mechanical engineer, philosopher, and Buddhist monk of the Tang dynasty (618–907). His astronomical celestial globe featured a clockwork escapement mechanism, the first in a long tradition of Chinese astronomical clockworks.
Science and technology.
Terrestrial-astronomical survey.
In the early 8th century, the Tang court put Yi Xing in charge of a terrestrial-astronomical survey. This survey had many purposes. It was established in order to obtain new astronomical data that would aid in the prediction of solar eclipses. The survey was also initiated so that flaws in the calendar system could be corrected and a new, updated calendar installed in its place. The survey was also essential in determining the measurement of the length of meridian arc-although Yi Xing, who did not know the Earth was spherical, did not conceptualize his measurements in these terms. This would resolve the confusion created by the earlier practice of using the difference between shadow lengths of the sun observed at the same time at two places to determine the ground distance between them.
Yi Xing had thirteen test sites established throughout the empire, extending from Jiaozhou in Vietnam — at latitude 17°N — to the region immediately south of Lake Baikal — latitude 50°N. There were three observations done for each site, one for the height of polaris, one for the shadow lengths of summer, and one for the shadow lengths of winter. The latitudes were deciphered from this data, while the Tang calculation for the length of one degree of meridian was fairly accurate compared to modern calculations. Yi Xing understood the variations in the length of a degree of meridian, and criticized earlier scholars who permanently fixed an estimate for shadow lengths for the duration of the entire year.
The escapement and celestial globe.
Yi Xing was famed for his genius, known to have calculated the number of possible positions on a go board game (though without a symbol for zero as he had difficulties expressing the number). He, along with his associate, the mechanical engineer and politician Liang Lingzan, is best known for applying the earliest-known escapement mechanism to a water-powered celestial globe. However, Yi Xing's mechanical genius and achievements were built upon the knowledge and efforts of previous Chinese mechanical engineers, such as the statesman and master of gear systems Zhang Heng (78–139) of the Han Dynasty, the mechanical engineer Ma Jun (200–265) of the Three Kingdoms, and the Daoist Li Lan (c. 450) of the Southern and Northern Dynasties period.
It was the earlier Chinese inventor Zhang Heng during the Han dynasty who was the first to apply hydraulic power (i.e. a waterwheel and water clock) in mechanically-driving and rotating his equatorial armillary sphere. The arrangement followed the model of a water-wheel using the drip of a clepsydra (see water clock), which ultimately exerted force on a lug to rotate toothed-gears on a polar-axis shaft. With this, the slow computational movement rotated the armillary sphere according to the recorded movements of the planets and stars. Yi Xing also owed much to the scholarly followers of Ma Jun, who had employed horizontal jack-wheels and other mechanical toys worked by waterwheels. The Daoist Li Lan was an expert at working with water clocks, creating steelyard balances for weighing water that was used in the tank of the clepsydra, providing more inspiration for Yi Xing. Like the earlier water-power employed by Zhang Heng and the later escapement mechanism in the astronomical clock tower engineered and erected by Su Song (1020–1101), Yi Xing's celestial globe employed water-power in order for it to rotate and function properly. The British biochemist, historian, and sinologist Joseph Needham states (Wade–Giles spelling):
In regards to mercury instead of water (as noted in the quote above), the first to apply liquid mercury for motive power of an armillary sphere was Zhang Sixun in 979 AD (because mercury would not freeze during winter). During his age, the Song dynasty (960–1279) era historical text of the "Song Shi" mentions Yi Xing and the reason why his armillary sphere did not survive the ages after the Tang (Wade–Giles spelling):
Earlier Tang era historical texts of the 9th century have this to say of Yi Xing's work in astronomical instruments in the 8th century (Wade–Giles spelling):
Buddhist scholarship.
Yi Xing wrote a commentary on the "Mahavairocana Tantra". This work had a strong influence on the Japanese monk Kūkai and was key in his establishment of Shingon Buddhism.
In his honor.
At the Tiantai-Buddhist Guoqing Temple of Mount Tiantai in Zhejiang Province, there is a Chinese pagoda erected directly outside the temple known as the Memorial Pagoda of Monk Yi Xing. His tomb is also located on Mount Tiantai.


Kuntsevskaya (Bolshaya Koltsevaya line)

Kuntsevskaya is a station on the Bolshaya Koltsevaya line of the Moscow Metro which is currently under construction. It will be opened in 2021.


Engineer Amphibian Command


YM-III mine

The YM-III or YM-3 is a circular ABS plastic cased Iranian minimum metal anti-tank blast mine. It is a copy of the Chinese Type 72 non-metallic anti-tank mine. The mine uses a blast-resistant fuze, which relies on gradual application of pressure to trigger it. The mine is found in Afghanistan, Bosnia, Iran, and Iraq.


Helmsley Building

The Helmsley Building is a 35-story building at 230 Park Avenue between East 45th and 46th streets in Midtown Manhattan, just north of Grand Central Terminal in New York City. It was built in 1929 as the New York Central Building and was designed by Warren & Wetmore in the Beaux-Arts style. It was the tallest structure in the "Terminal City" complex around Grand Central prior to the completion of what is now the MetLife Building.
The Helmsley Building carries vehicular traffic through its base: traffic exits and enters the Park Avenue Viaduct through two portals passing under the building. The lobby of the building is between the vehicular portals. Flanking the viaduct's ramps are passageways connecting 45th and 46th streets, with entrances to Grand Central Terminal.
Before the construction of Grand Central Terminal, the area to the north of the predecessor Grand Central Depot was occupied by an open-air rail yard; the tracks and depot were operated by the New York Central Railroad. After the terminal was completed in 1913, the tracks were buried under a series of buildings that were constructed over the tracks as part of the Terminal City development. The New York Central Building was erected for the railroad between 1927 and 1929 as the last major structure to be built within Terminal City. It was renamed the New York General Building in 1958 and the Helmsley Building in 1978, though ownership was changed several times afterward. The building and its lobby were designated as New York City Landmark spaces in 1987.
Site.
The Helmsley Building straddles the ramps of the Park Avenue Viaduct in Midtown Manhattan, bounded by 45th Street to the south, Vanderbilt Avenue to the west, 46th Street to the north, and Depew Place to the east. Its address is 230 Park Avenue. It is just north of Grand Central Terminal and the MetLife Building. The Helmsley Building measures north-south and west-east. The Helmsley Building was developed as part of the original "Terminal City" complex above Grand Central Terminal's rail yards.
Design.
The Helmsley Building was designed by Warren & Wetmore. The design is influenced by that of the Manhattan Municipal Building, which spanned Chambers Street in Lower Manhattan, with side wings projecting to the west and east. The wings slightly resemble the "court of honor" designed by Reed and Stem, another collaborator in the Grand Central project.
The eastern and western wings are each 15 stories tall, while a centrally positioned tower rises another 20 stories. The lowest four stories comprise the base, which include the lobbies and the viaduct ramps. The eleven stories above it comprise an office block with a floor plan shaped like an irregular "H" aligned west–east. The western wings project further than the eastern wings, and the center of the northern facade curves slightly inward. The 20-story tower has a floor plan measuring . It terminates in a pyramidal roof with an octagonal base.
The building has of office space. Of this, the lower 15 floors each have an area of and the upper 20 floors each cover . The building was erected with forty elevators, but only twenty-five are in use.
Facade.
The facade of the four-story base is composed of limestone and Texas pink granite. It includes bronze grilles as well as sculptures depicting industrial progress. There is a clock atop the base, located above the ground with a diameter of . The clock is flanked by a figure of the god Mercury on the left, representing transportation, and a figure of the goddess Ceres on the right, representing Industry. The composition measures tall by wide and was designed by Edward McCartan. The windows on the base contain one of four types of display-window designs: the original designs installed with the rest of the building in 1929, and one of three modifications. The pedimental sculptures were carved by the Ardolino Brothers.
The upper stories are faced with brick. The northern facade of the fifth through 15th stories curve along the wings. The facade of this section contains paired sash windows with decorative metal spandrels, as well as limestone keystones above the windows on the 15th story. Above the 15th floor is a cornice with 78 terracotta bison heads, which symbolize industry. The cornice also contains images of Mercury's winged helmet, winged wheels representing advancement, scrolls of wisdom, wheels of progress, and other motifs. The 15th story of the eastern facade had a sky bridge that connected to 466 Lexington Avenue until the bridge was demolished in 1982.
The 16th through 35th-story facades contain identical decorative elements on all sides. Like the lower stories, these are faced with brick and contain paired sash windows. Above the 28th floor are limestone keystones over the windows, as well as a cornice with brackets. There is an ornate entablature above the 31st floor; keystones above the 32nd-floor windows; bracketed keystones above the 33rd floor windows; and an observation deck on the 33rd floor. The last full floor, the 34th floor, has three pairs of windows on all sides, protruding from the roof as dormers.
The top of the Helmsley Building is a pyramid and capped by an ornate cupola. The roof was lit at night by electric floodlights and torches with up to 100,000 candlepower. At the pinnacle were "32-marine-type fixtures" that each had a capacity of up to 100 watts. The cupola had oval openings and was topped by a glass ball with a 6,000 watt lantern. Eight projectors, one from each corner of the octagon's base, also illuminated the roof. The lighting made the Helmsley Building into a point of interest that could be seen from several miles away. When the Helmsley Building was completed, the copper roof was gilded, but by the late 1950s had been painted green. The gilding was restored in the 1970s and removed in 2002.
Features.
Structural features.
The building uses of steel, of which went into the foundation. There are two levels of tracks underneath the building. Due to the different track layouts on each level, the columns on each level were offset, preventing through-columns from being built. Furthermore, the tracks were electrified and more than 700 trains passed through each day. As a solution, girders were installed above the lower track level, and the steel frame for the building was placed upon these girders and insulated with vibration-proof mats and cork tubes.
The Helmsley Building did not have basements because that space was occupied by the tracks. Because of this, the machinery, utilities, and storage areas were installed on the 15th floor.
Lobby.
Inside the base are two S-ramps carrying Park Avenue to the Park Avenue Viaduct. The western ramp carries southbound traffic and the eastern ramp carries northbound traffic, The two arcades are located on the outside of the ramps, connecting 45th and 46th streets. The arcades contain shopfronts on the sides facing away from the viaduct's ramps: the west side of the western arcade and the east side of the eastern arcade. The arcades are connected to Grand Central North, a system of passageways that lead to Grand Central, which opened in 1999.
The lobby is located in the median of the two ramps between 45th and 46th streets, with passageways to either side of the roadways. The interior is designed to evoke New York Central's "prowess". This is evidenced in the walls, which are made of marble, as well as the detailing of the bronze, where the railroad's initials are repeated many times. A vestibule leads from 46th Street and contains multi-pane windows, bronze doors, a chandelier, and a pair of flanking vestibules with small storefronts. Another nearly-identical but smaller vestibule on the southern end, near 45th Street, leads to the western walkway.
The lobby itself contains bronze chandeliers and an elaborate cornice with brackets and friezes. There are thirty-two elevators, grouped in eight banks of four, labeled "A" through "H". The elevator banks are double-height arched vestibules, with marble frames around the elevator openings, as well as bronze-ornamented elevator indicators. The elevators contain elaborately decorated bronze doors painted "Chinese red", with the railroad's initials. The elevator cab interiors contain Chinese red walls with wood moldings, as well as ceilings with gift domes and painted cloudscapes. The elevator banks and cabs are similar, with minor variations.
History.
In the 19th century, the New York Central Railroad lines north of Grand Central Depot in Midtown Manhattan were served exclusively by steam locomotives, and the rising traffic soon caused accumulations of smoke and soot in the Park Avenue Tunnel, the only approach to the depot. After a fatal crash in 1902, the New York state legislature passed a law to ban all steam trains in Manhattan by 1908. New York Central's vice president William J. Wilgus proposed electrifying the line and building a new electric-train terminal underground, a plan that was implemented almost in its entirety. The old Grand Central Depot was torn down in phases and replaced by the current Grand Central Terminal. Construction on Grand Central Terminal started on June 19, 1903, and the new terminal was opened on February 2, 1913.
Passenger traffic on the commuter lines into Grand Central more than doubled in the years following the terminal's completion. The terminal spurred development in the surrounding area, particularly in Terminal City, a commercial and office district created above where the tracks were covered. Terminal City soon became Manhattan's most desirable commercial and office district. A 1920 "New York Times" article said, "With its hotels, office buildings, apartments and underground streets it not only is a wonderful railroad terminal, but also a great civic centre." Most of these buildings were designed by Warren & Wetmore, which had also designed the terminal itself.
Planning and construction.
Early plans.
Following Grand Central Terminal's completion, one of the first plans for development on the Helmsley Building's current site took place in 1914, when the Winter Sports Club secured an option from New York Central to build property on the east side of Park Avenue between 45th and 46th streets. The development of Terminal City had included the construction of the Park Avenue Viaduct, surrounding Grand Central Terminal. The first part of the viaduct had opened in 1919, carrying traffic from Park Avenue and 40th Street to Vanderbilt Avenue and 45th Street. Initially, only the western leg of the present-day viaduct was open to traffic, and there was a severe bottleneck at Vanderbilt Avenue and 45th Street. As such, the city government refused to issue construction permits for buildings on Park Avenue between 45th and 46th streets until the bottleneck was resolved. The city started negotiating with New York Central to open the eastern leg of the viaduct, although the railroad was holding out unless it was granted property on Park Avenue. At the time, New York Central had planned to build two buildings, one on either side of Park Avenue.
New York Central proposed a single 16-story building over Park Avenue in 1922. Two years later, New York Central and the city reached an agreement to build a single building over Park Avenue, in exchange for an extension of Vanderbilt Avenue from 45th to 47th Streets, and the completion of the viaduct through the new building over Park Avenue. The project to complete the Park Avenue Viaduct proceeded after the proposal was certified by Charles L. Craig, the city controller, in 1925. The final plan for the New York Central Building above Park Avenue was not completed until February 1927. As part of the plan, the viaduct's roadways would cross over 45th Street without intersection, descending to ground level within the building. The plan also included provisions for the extension of Park Avenue's sidewalks from 46th to 45th Streets through the building.
Construction.
New York Central was responsible for all of the component projects of construction, including the viaduct ramps and the pedestrian walkways, while the city government provided support. The collaboration was described by "The New York Times" as "a fine example of the way in which private undertakings, when intelligently coordinated with municipal interests, can bring about a real public improvement".
Construction of the foundation started in December 1926. At that time, New York Central opened bids for the procurement of of steel. Warren and Wetmore filed building plans in February 1927, and a contract for of steel was awarded to the McClintic-Marshall Company the next month. James Stewart & Company were hired to place the foundation's piers deep. That July, New York Central awarded the general construction contract to James Stewart & Company. Because the steel beams were so large, they could not be moved through city streets, so they were delivered by rail. The steelwork had reached the ground level by November 1927. The building topped out on April 5, 1928, though Chauncey Depew, the chairman of the railroad's board of directors, had died several hours before the topping-out ceremony.
New York Central use.
The New York Central Building received a temporary occupancy certificate in December 1928, and its roof was first lit in January 1929. However, the building was not considered completed until September 25, 1929, when all construction was finished. According to later sources, the building was considered to be the last major project erected as part of Terminal City. New York Central moved its administrative headquarters to the 32nd and 33rd floors, while the remaining floors were leased to tenants. The 32nd floor had a boardroom with English wood paneling gifted by the Van Swearingen brothers (who were railroad barons), as well as the president's and chairman's suites.
The Railway Express Agency moved all its departments into one floor of the New York Central Building in April 1930. There were other railroad-related tenants such as equipment manufacturer Symington Company, as well as the American Brake Shoe and Foundry Company, and the Delaware and Hudson Railway. In the first decades of the building's history, its other tenants included publisher McCall Company, paper manufacturer Eastern Manufacturing Company, and Colonial Airlines. Salvatore Maranzano, a boss for the American Mafia, had an office on the ninth floor, where he worked for the Eagle Building Corporation. On September 10, 1931, he was killed by hitmen sent by Lucky Luciano and Vito Genovese, ambitious underlings whom Maranzano had hired Vincent "Mad Dog" Coll to kill.
The New York Central Building's windows were blacked out as a safety measure during World War II. During the 1950s, New York Central undertook a multi-million-dollar restoration of the building, and in 1958, put the building up for lease. That year, Irving Brodsky of the New York Bank for Savings assumed a 50-year leasehold and renamed it the New York General Building. Upon the New York Central's Building's renaming, the "C" and "T" on the facade's plaque were chiseled into "G" and "E" respectively. The renaming is sometimes credited to Harry Helmsley, a later owner of the building; he said that the change had been made for cost-saving reasons.
Subsequent use.
Helmsley ownership.
New York Central had merged with the Pennsylvania Railroad in 1968 to form the Penn Central Railroad. The same year, the New York Central Building was sold to the General Tire & Rubber Company. After Penn Central went bankrupt in 1970, it sought to sell its properties. By the next year, Penn Central trustees had signed contracts to sell the New York General Building. The proceedings were delayed for several years, as federal judge John P. Fullam refused to approve the sale of the New York General Building, while approving four of Penn Central's other sales. In December 1975, the trustees petitioned Fullam to sell the building to the New York Bank for Savings for $7 million in cash and $19 million in a 33.5-year mortgage. The sale was finalized early the next year. The major ownership stake was sold to Harry Helmsley's company Helmsley-Spear Management in 1977.
After Helmsley's purchase, both the exterior and interior of the New York General Building were restored. The green rusted-copper roof, which suffered from leaks, was gilded and waterproofed. The facade was also extensively cleaned. The clock and other ornaments on the facade were also gilded, floodlights were activated at the top and bottom, and the letters were installed on the facade. The building became known as the Helmsley Building in December 1978, following the refurbishment project's completion. According to Harry Helmsley, the renaming was suggested by his wife Leona. Despite the name, the Helmsleys were only one of several stakeholders in 230 Park Avenue Associates, which owned the building.
The New York City Landmarks Preservation Commission designated the Helmsley Building and its first-floor interior as official city landmarks in 1987. The first-floor interior designation included the lobby, seven of the eight elevator banks, and the entrance vestibules. "The New York Times" reported in 2011 that the building's interior landmark designation was difficult to maintain. The lobbies had to be cleaned every month, and restoration of the building's landmarked elevators required an artist to repaint the elevators' ceiling frescoes by hand.
A connection from the Grand Central North passageways to the building's pedestrian arcades was announced in 1994 and opened in 1999. After Harry Helmsley died in early 1996, Leona transferred the building's management to the Helmsley-Noyes Company. Leona Helmsley maintained her offices in the Helmsley Building.
Further sales.
The Helmsley Building was owned by Helmsley-Spear until August 1998, when it was sold to the Max Capital Management Corporation for $225 million. The terms of the sale stipulated that the building would not be renamed again. Max Capital subsequently hired Skidmore, Owings & Merrill to design the building's $50 million renovation. Starting in 2000, the building's arcades were shut down one at a time for renovation. The advertising boards in the arcades were removed, and the mezzanine floors in the arcades were demolished to double the ceiling height. Light shafts, TV screens, and bronze storefronts were installed as well. The gilding was removed during the renovation as well. In 2002, the owners stopped lighting certain rooms inside the Helmsley Building during nights in December. When the room-lighting had occurred in previous years, the rooms would be lit so the pattern on the facade resembled a cross; it was controversial among Jewish residents of Park Avenue, but according to Max Capital, the lighting pattern was stopped for security reasons.
In 2005, the Helmsley Building was sold again to Istithmar, an investment firm owned by the royal family of Dubai, for $705 million. Two years later, it was sold to Goldman Sachs in 2007 for over $1 billion. Following a 2010 renovation, the Helmsley Building became the first building erected prior to World War II to receive a Leadership in Energy and Environmental Design certification for green buildings. In May 2015, the Helmsley Building was sold for $1.2 billion to property firm RXR Realty.
Tenants.
, tenants at the Helmsley Building include 5W Public Relations (5WPR), Cornell University, Comerica Bank, Elsevier, Encyclopædia Britannica, HSH Nordbank AG, LexisNexis, the New York Court of Appeals, Novartis, Powermat, Simon Property Group, Six Flags, Stanley Hand Tools, Tokio Marine Management, and Voya Financial. In addition, a food hall called Urban Space opened in within the Helmsley Building in 2014.
Critical reception.
Early critics had mixed reviews of the building. George Shepard Chappell, writing for "The New Yorker" in 1928 and 1929, called it "a dramatic stop sign at the end of the thoroughfare", and described the lobby's styles as ranging "from Pullman to Paramount". Harry F. Cunningham reviewed the building much more harshly in a 1928 issue of "The American Yearbook", calling the building "one of the greatest steps in the present backward tendency shown in American architecture" for its rejection of modernist styles In a book published in 1932, W. Parker Chase called the Helmsley Building "the most remarkable office building in the world", saying that the construction of the George Washington Bridge—then the world's longest suspension bridge—was about as complex as the Helmsley Building's construction.
Later reviews were more positive. Nathan Silver wrote in his 1967 book "Lost New York": "With its outline and decoration, [the Helmsley Building] was able to indicate clearly its relationship to the height of a man." John Tauranac, in a guidebook published in 1978, said that the design was "absolutely glorious". Paul Goldberger of "The New York Times" wrote in 1978 that the Helmsley Building "picks up on the architectural elements of Park Avenue, but transforms them into something more exuberant". Christopher Gray, writing for the same newspaper, stated in 1996: "The middle section is handsome, but the top explodes like a Caribbean coral formation." A partner at Kohn Pederson Fox said in 1984 that the gilding of the Helmsley Building "is rather excessive, and not architecturally appropriate".
The building's clock also received critical attention. Architecture critic Royal Cortissoz called the clock "one of the most conspicuous sculptural decorations ever erected in the city". The "New York Daily News" editorial team expressed disappointment that the clock was not more prominent, and that there was no clock tower.


Thomas Savin

Thomas Savin (1826 – 23 July 1889) was a British railway engineer who was the contractor who built many railways in Wales and the Welsh borders from 1857 to 1866. He also in some cases was an investor in such schemes.
Early life.
Savin was born in Shropshire at Llwynymaen near Oswestry in 1826. He married in 1852 Eliza Hughes with whom he had two sons who survived him. He initially worked in Oswestry running a mercery business in partnership with Edward Morris, who subsequently purchased then sold the Van lead mines.
Railway contractor.
In 1857 Savin formed a partnership with David Davies to build the Vale of Clwyd Railway. The partnership was the principal contractor for many of the lines that became the Cambrian Railways. The partnership was dissolved in 1860. He also had an interest in or worked on a number of secondary and minor railways, including the Oswestry and Newtown Railway, Brecon and Merthyr Tydfil Junction Railway, the Hereford, Hay and Brecon Railway, the narrow gauge Corris Railway, the Kington & Eardisley Railway, the Bishop's Castle Railway. and Aberystwith and Welsh Coast Railway which connected the interior of mid-Wales from Machynlleth to the coast with the completion of the line and the opening of Aberystwyth station in 1864, and became part of the Cambrian Railways in 1865.
Savin followed up the opening of the last-named line with the creation of Aberystwyth's Castle Hotel to capitalise on the local seaside trade. He bought Castle House and converted it into a large hotel. He produced 'probably the first package holiday deal' whereby tickets bought by passengers at various railway stations in parts of England would entitle the buyer not only to the journey to and from Aberystwyth but board and lodging at the resort. It was opened in June 1865 while still incomplete but he had to stop work after £80,000 had been spent on it when he became bankrupt amid the failure of Overend, Gurney in 1866, at which point his enterprises involved a total of about £1.5 million. It was sold for £10,000 in March 1867 when it was purchased to become the first building for the University College of Wales.
Industry.
Savin owned a number of industrial companies across Wales. He owned a colliery, The New British Coalpit, at Coed-y-go, served by a branch line he built privately off the Oswestry & Newtown line, which carried twenty wagons of coal daily each way before the colliery closed in 1869.
He was the owner of the Cooper's Lime Rocks limestone quarry at Porthywaen in 1872, which suffered from a significant accident. Kegs of gunpowder were hauled up the incline to the magazine in the quarry. As the most recent set of kegs were being moved into the magazine, an empty wagon broke loose and collided at high speed with one of the kegs. The resulting explosion killed six workers employed by Savin.
Politics and other interests.
David Davies had entered active politics in 1865 when he unsuccessfully fought at Cardiganshire in the General Election. Later that year Savin was briefly mentioned as a possible Liberal candidate for Brecon. Savin served in local politics in Oswestry, to whose borough council he was elected in 1856, became Mayor of the town in 1866, and was alderman from 1871 until his death. He left the Liberal party and became a Conservative because of his support for Benjamin Disraeli's stance over Bulgaria and Turkey against Russia in the 1870s.
Savin served in the volunteer force as lieutenant in the Montgomeryshire Rifles and was captain of the 15th (Oswestry) company of the Shropshire Rifle Volunteers in 1864. He was also a Fellow of the Royal Horticultural Society and Associate Member of the Institution of Civil Engineers.
Later life.
Savin died at his home, Ivy House, in Salop Road, Oswestry on 23 July 1889, aged 63, and was buried in Oswestry Cemetery on 26 July (Section D, Grave 34).


Solenoid

A solenoid (, from the Greek "sōlēnoeidḗs", "pipe-shaped") is a type of electromagnet, the purpose of which is to generate a controlled magnetic field through a coil wound into a tightly packed helix. The coil can be arranged to produce a uniform magnetic field in a volume of space when an electric current is passed through it. The term "solenoid" was coined in 1823 by André-Marie Ampère to designate a helical coil.
In the study of electromagnetism, a solenoid is a coil whose length is substantially greater than its diameter. The helical coil of a solenoid does not necessarily need to revolve around a straight-line axis; for example, William Sturgeon's electromagnet of 1824 consisted of a solenoid bent into a horseshoe shape.
In engineering, the term may also refer to a variety of transducer devices that convert energy into linear motion. In simple terms, a solenoid converts electrical energy into mechanical work. The term is also often used to refer to a solenoid valve, an integrated device containing an electromechanical solenoid which actuates either a pneumatic or hydraulic valve, or a solenoid switch, which is a specific type of relay that internally uses an electromechanical solenoid to operate an electrical switch; for example, an automobile starter solenoid or linear solenoid. Solenoid bolts, a type of electromechanical locking mechanism, also exist. In electromagnetic technology, a solenoid is an actuator assembly with a sliding ferromagnetic plunger inside the coil. Without power, the plunger extends for part of its length outside the coil; applying power pulls the plunger into the coil. Electromagnets with fixed cores are not considered solenoids.
Infinite continuous solenoid.
An infinite solenoid has infinite length but finite diameter. "Continuous" means that the solenoid is not formed by discrete finite-width coils but by many infinitely thin coils with no space between them; in this abstraction, the solenoid is often viewed as a cylindrical sheet of conductive material.
Inside.
The magnetic field inside an infinitely long solenoid is homogeneous and its strength neither depends on the distance from the axis nor on the solenoid's cross-sectional area.
This is a derivation of the magnetic flux density around a solenoid that is long enough so that fringe effects can be ignored. In Figure 1, we immediately know that the flux density vector points in the positive "z" direction inside the solenoid, and in the negative "z" direction outside the solenoid. We confirm this by applying the right hand grip rule for the field around a wire. If we wrap our right hand around a wire with the thumb pointing in the direction of the current, the curl of the fingers shows how the field behaves. Since we are dealing with a long solenoid, all of the components of the magnetic field not pointing upwards cancel out by symmetry. Outside, a similar cancellation occurs, and the field is only pointing downwards.
Now consider the imaginary loop "c" that is located inside the solenoid. By Ampère's law, we know that the line integral of B (the magnetic flux density vector) around this loop is zero, since it encloses no electrical currents (it can be also assumed that the circuital electric field passing through the loop is constant under such conditions: a constant or constantly changing current through the solenoid). We have shown above that the field is pointing upwards inside the solenoid, so the horizontal portions of loop "c" do not contribute anything to the integral. Thus the integral of the up side 1 is equal to the integral of the down side 2. Since we can arbitrarily change the dimensions of the loop and get the same result, the only physical explanation is that the integrands are actually equal, that is, the magnetic field inside the solenoid is radially uniform. Note, though, that nothing prohibits it from varying longitudinally, which in fact, it does.
Outside.
A similar argument can be applied to the loop "a" to conclude that the field outside the solenoid is radially uniform or constant. This last result, which holds strictly true only near the center of the solenoid where the field lines are parallel to its length, is important as it shows that the flux density outside is practically zero since the radii of the field outside the solenoid will tend to infinity.
An intuitive argument can also be used to show that the flux density outside the solenoid is actually zero. Magnetic field lines only exist as loops, they cannot diverge from or converge to a point like electric field lines can (see Gauss's law for magnetism). The magnetic field lines follow the longitudinal path of the solenoid inside, so they must go in the opposite direction outside of the solenoid so that the lines can form a loop. However, the volume outside the solenoid is much greater than the volume inside, so the density of magnetic field lines outside is greatly reduced. Now recall that the field outside is constant. In order for the total number of field lines to be conserved, the field outside must go to zero as the solenoid gets longer.
Of course, if the solenoid is constructed as a wire spiral (as often done in practice), then it emanates an outside field the same way as a single wire, due to the current flowing overall down the length of the solenoid.
Quantitative description.
Applying Ampère's circuital law to the solenoid (see figure on the right) gives us
where formula_2 is the magnetic flux density, formula_3 is the length of the solenoid, formula_4 is the magnetic constant, formula_5 the number of turns, and formula_6 the current. From this we get
This equation is valid for a solenoid in free space, which means the permeability of the magnetic path is the same as permeability of free space, μ0.
If the solenoid is immersed in a material with relative permeability μr, then the field is increased by that amount:
In most solenoids, the solenoid is not immersed in a higher permeability material, but rather some portion of the space around the solenoid has the higher permeability material and some is just air (which behaves much like free space). In that scenario, the full effect of the high permeability material is not seen, but there will be an effective (or apparent) permeability "μ"eff such that 1 ≤ "μ"eff ≤ "μ"r.
The inclusion of a ferromagnetic core, such as iron, increases the magnitude of the magnetic flux density in the solenoid and raises the effective permeability of the magnetic path. This is expressed by the formula
where "μ"eff is the effective or apparent permeability of the core. The effective permeability is a function of the geometric properties of the core and its relative permeability. The terms relative permeability (a property of just the material) and effective permeability (a property of the whole structure) are often confused; they can differ by many orders of magnitude.
For an open magnetic structure, the relationship between the effective permeability and relative permeability is given as follows:
where "k" is the demagnetization factor of the core.
Finite continuous solenoid.
A finite solenoid is a solenoid with finite length. Continuous means that the solenoid is not formed by discrete coils but by a sheet of conductive material. We assume the current is uniformly distributed on the surface of the solenoid, with a surface current density "K"; in cylindrical coordinates:
The magnetic field can be found using the vector potential, which for a finite solenoid with radius "R" and length "l" in cylindrical coordinates formula_12 is
where
Here, formula_20, formula_21, and formula_22 are complete elliptic integrals of the first, second, and third kind.
Using
the magnetic flux density is obtained as
On the symmetry axis, the radial component vanishes, and the axial field component is
Inside the solenoid, far away from the ends (formula_27), this tends towards the constant value formula_28.
Finite non-continuous solenoid estimate.
For the case in which the radius is much larger than the length of the solenoid, the magnetic flux density through the centre of the solenoid (in the "z" direction, parallel to the solenoid's length, where the coil is centered at "z"=0) can be estimated as the flux density of a single circular conductor loop:
For cases in which the radius is not large compared to the length, this estimate can be further refined by summating it over "N" number of wire turnings/coils at different positions along "z".
Irregular solenoids.
Within the category of finite solenoids, there are those that are sparsely wound with a single pitch, sparsely wound with varying pitches (varied-pitch solenoid), or those with a varying radius for different loops (non-cylindrical solenoids). They are called irregular solenoids. They have found applications in different areas, such as sparsely wound solenoids for wireless power transfer, varied-pitch solenoids for magnetic resonance imaging (MRI), and non-cylindrical solenoids for other medical devices.
The calculation of the intrinsic inductance and capacitance cannot be done using those for the traditional solenoids, i.e. the tightly wound ones. New calculation methods were proposed for the calculation of intrinsic inductance(codes available at ) and capacitance. (codes available at )
Inductance.
As shown above, the magnetic flux density formula_2 within the coil is practically constant and given by
where "μ"0 is the magnetic constant, formula_5 the number of turns, formula_6 the current and formula_3 the length of the coil. Ignoring end effects, the total magnetic flux through the coil is obtained by multiplying the flux density formula_2 by the cross-section area formula_36:
Combining this with the definition of inductance
the inductance of a solenoid follows as
A table of inductance for short solenoids of various diameter to length ratios has been calculated by Dellinger, Whittmore, and Ould.
This, and the inductance of more complicated shapes, can be derived from Maxwell's equations. For rigid air-core coils, inductance is a function of coil geometry and number of turns, and is independent of current.
Similar analysis applies to a solenoid with a magnetic core, but only if the length of the coil is much greater than the product of the relative permeability of the magnetic core and the diameter. That limits the simple analysis to low-permeability cores, or extremely long thin solenoids. The presence of a core can be taken into account in the above equations by replacing the magnetic constant "μ0" with "μ" or "μ0μr", where "μ" represents permeability and "μr" relative permeability. Note that since the permeability of ferromagnetic materials changes with applied magnetic flux, the inductance of a coil with a ferromagnetic core will generally vary with current.
Applications.
Electromechanical solenoid.
Electromechanical solenoids consist of an electromagnetically inductive coil, wound around a movable steel or iron slug (termed the armature). The coil is shaped such that the armature can be moved in and out of the space in the center of the coil, altering the coil's inductance and thereby becoming an electromagnet. The movement of the armature is used to provide a mechanical force to some mechanism, such as controlling a solenoid valve. Although typically weak over anything but very short distances, solenoids may be controlled directly by a controller circuit, and thus have very quick reaction times.
The force applied to the armature is proportional to the change in inductance of the coil with respect to the change in position of the armature and the current flowing through the coil (see Faraday's law of induction). The force applied to the armature will always move the armature in a direction that increases the coil's inductance.
Electromechanical solenoids are commonly seen in electronic paintball markers, pinball machines, dot matrix printers, and fuel injectors. Some residential doorbells make use of electromechanical solenoids, whereby electrification of the coil causes the armature to strike metal chime bars.
Proportional solenoid.
Included in this category of solenoids are the uniquely designed magnetic circuits that effect analog positioning of the solenoid plunger or armature as a function of coil current. These solenoids, whether axial or rotary, employ a flux carrying geometry that both produces a high starting force (torque), and has a section that quickly begins to saturate magnetically. The resulting force (torque) profile as the solenoid progresses through its operational stroke is nearly flat or descends from a high to a lower value. The solenoid can be useful for positioning, stopping mid-stroke, or for low velocity actuation; especially in a closed loop control system. A uni-directional solenoid would actuate against an opposing force or a dual solenoid system would be self cycling. The proportional concept is more fully described in SAE publication 860759 (1986).
Focusing of the magnetic field and its attendant flux metering, as illustrated in the SAE paper, is required to produce a high starting force at the start of the solenoid stroke and to maintain a level or declining force as the solenoid moves through its displacement range. This is quite contrary to that experienced with normal diminishing air gap types of solenoids. The focusing of the magnetic field to the working air gap initially produces a high mmf (ampere turns) and relatively low flux level across the air gap. This high product of mmf x flux (read energy) produces a high starting force. As the plunger is incremented (ds) the energy of motion, F∙ds, is extracted from the air gap energy. Inherent with the plunger increment of motion, the air gap permeance increases slightly, the magnetic flux increases, the mmf across the air gap decreases slightly; all of which results in maintaining a high product of mmf x flux. Because of the increased flux level a rise in ampere-turns drops elsewhere in the ferrous circuit (predominately in the pole geometry) causes the reduction of air gap ampere-turns and, therefore, the reduced potential energy of the field at the air gap. Further incrementing of the plunger causes a continuing decrease of the solenoid force thus creating an ideal condition for motion control as controlled by the current to the solenoid coil. The aforementioned pole geometry, having a linearly changing path area, produces a nearly linear change in force. An opposing spring force or a dual ended solenoid (two coils) allows over and back motion control. Closed loop control improves the linearity and stiffness of the system.
Rotary solenoid.
The rotary solenoid is an electromechanical device used to rotate a ratcheting mechanism when power is applied. These were used in the 1950s for rotary snap-switch automation in electromechanical controls. Repeated actuation of the rotary solenoid advances the snap-switch forward one position. Two rotary actuators on opposite ends of the rotary snap-switch shaft, can advance or reverse the switch position.
The rotary solenoid has a similar appearance to a linear solenoid, except that the armature core is mounted in the center of a large flat disk, with three inclined raceways coined into the underside of the disk. These grooves align with raceways on the solenoid body, separated by ball bearings in the races.
When the solenoid is activated, the armature core is magnetically attracted toward the stator pole, and the disk rotates on the ball bearings in the races as it moves towards the coil body. When power is removed, a spring on the disk rotates it back to its starting position both rotationally and axially.
The rotary solenoid was invented in 1944 by George H. Leland, of Dayton, Ohio, to provide a more reliable and shock/vibration tolerant release mechanism for air-dropped bombs. Previously used linear (axial) solenoids were prone to inadvertent releases. U.S. Patent number 2,496,880 describes the electromagnet and inclined raceways that are the basis of the invention. Leland's engineer, Earl W. Kerman, was instrumental in developing a compatible bomb release shackle that incorporated the rotary solenoid. Bomb shackles of this type are found in a B-29 aircraft fuselage on display at the National Museum of the USAF in Dayton, Ohio. Solenoids of this variety continue to be used in countless modern applications and are still manufactured under Leland's original brand "Ledex", now owned by Johnson Electric.
Appearing on the market in the 1980s, the solely rotary solenoid with a balanced 3-lobed iron vane rotor offered improved vibration isolation by eliminating the axial motion of the rotor. This device allowed proportional, quiet positioning as well as a rapid rotation for uses such as mail sorters and conveyor gating. Then followed a permanent magnet rotor version (U.S. Patent 5,337,030; 1994 ) that provided rapid, electrical, bi-directional rotation.
Rotary voice coil.
A rotary voice coil is a rotational version of a solenoid. Typically the fixed magnet is on the outside, and the coil part moves in an arc controlled by the current flow through the coils. Rotary voice coils are widely employed in devices such as disk drives. The working part of a moving coil meter is also a type of rotary voice coil that pivots around the pointer axis, a hairspring is usually used to provide a weak nearly linear restoring force.
Pneumatic solenoid valve.
A pneumatic solenoid valve is a switch for routing air to any pneumatic device, usually an actuator, allowing a relatively small signal to control a large device. It is also the interface between electronic controllers and pneumatic systems.
Hydraulic solenoid valve.
Hydraulic solenoid valves are in general similar to pneumatic solenoid valves except that they control the flow of hydraulic fluid (oil), often at around 3000 psi (210 bar, 21 MPa, 21 MN/m2). Hydraulic machinery uses solenoids to control the flow of oil to rams or actuators. Solenoid-controlled valves are often used in irrigation systems, where a relatively weak solenoid opens and closes a small pilot valve, which in turn activates the main valve by applying fluid pressure to a piston or diaphragm that is mechanically coupled to the main valve.
Solenoids are also in everyday household items such as washing machines to control the flow and amount of water into the drum.
Transmission solenoids control fluid flow through an automatic transmission and are typically installed in the transmission valve body.
Automobile starter solenoid.
In a car or truck, the starter solenoid is part of an automobile engine's ignition system. The starter solenoid receives a large electric current from the car battery and a small electric current from the ignition switch. When the ignition switch is turned on (i.e. when the key is turned to start the car), the small electric current forces the starter solenoid to close a pair of heavy contacts, thus relaying the large electric current to the starter motor. This is a type of relay.
Starter solenoids can also be built into the starter itself, often visible on the outside of the starter. If a starter solenoid receives insufficient power from the battery, it will fail to start the motor and may produce a rapid, distinctive "clicking" or "clacking" sound. This can be caused by a low or dead battery, by corroded or loose connections to the battery, or by a broken or damaged positive (red) cable from the battery. Any of these will result in some power to the solenoid, but not enough to hold the heavy contacts closed, so the starter motor itself never spins, and the engine fails to start.


Silas Hoadley

Silas Hoadley (1786 – December 28, 1870) was an American clockmaker.
Biography.
Hoadley was born in Bethany, Connecticut and was a cousin of the architect and builder David Hoadley. He received little formal education before becoming apprentice carpenter to his uncle Calvin Hoadley. In 1809 his apprenticeship ended, and he formed a clock-making partnership in Plymouth, Connecticut with Eli Terry and Seth Thomas as Terry, Thomas & Hoadley.
The partners gradually withdrew to create their own firms – Terry in 1810, Thomas in 1814 – leaving Silas Hoadley as sole owner. He continued to make clocks until 1849.
Hoadley was a Freemason of high standing and one of the most respected and oldest members of Harmony lodge, No. 42 F. and A. M. having been intimately associated with the lodge in Watertown, Connecticut in 1817. his lodge bears testimony that "His heart was in the right place, with a hand as open as the day to meeting charity, of him it may be truly said an honest man is the noblest work of god".
Hoadley was elected to the Connecticut General Assembly several times, and in 1844 to the Connecticut State Senate. He died at Plymouth, Connecticut.
Family Life.
Hoadley was married to Sarah N. Painter Hoadley (they are buried together in West Cemetery, and share a stone). His children where Milo, born July 25, 1809, married Sarah E. Scoville; George Thompson, born September 11, 1811, married Eunice Tomlinson; Luther Hopkins, born July 29, 1813, married first, Jane E. Welton, second Ellen Nicholson; Sarah Jane, born June 22, 1817, married September 1832, Hon. Henry A. Mitchel of Bristol, CT; Mary ann, born may 4, 1814, married first, September 2, 1836, George B. Semour, Washington, CT, second, June 17, George Tomlinson of Plymouth, CT
Death.
Hoadley died on December 28, 1870 and is interred at West Cemetery in Plymouth, Connecticut.


John Buck (winemaker)

John Kenneth Buck is chairman of Te Mata Estate winery and is widely recognised for his contributions to fine wine and the New Zealand wine industry.
Career.
Buck was involved in wine judging in New Zealand and Australia for many years, beginning in 1969 after he published a book on the subject called "Take a Little Wine". In 1979, he became chairman of judges for the national wine show. He was the first New Zealander to hold this position.
Buck was also chairman of the board of the Hawke's Bay Opera House and the patron of Cranford Hospice. In 1991, he founded the Hawke's Bay charity wine auction, and has been previously chairman of Hawkes Bay Vintners, which he helped establish. From 1991 to 1996, he served as chairman of the New Zealand Wine Institute. He has represented the wine industry at international trade negotiations, gaining access to the European Union, and had a regular wine series on Radio New Zealand as well as fronting documentaries for the same network in the Spectrum series.
Since 1974, Buck and his wife Wendy have managed New Zealand's oldest winery, Te Mata Estate. They live in the Coleraine Vineyard opposite the winery, have three sons who work at Te Mata — Jonathan, Nick and Tobias Buck — and six grandchildren. Coleraine — the red wine made from the Buck family vineyard — has repeatedly been named New Zealand's greatest red wine, and has achieved many accolades in New Zealand and internationally.
Recognition.
Buck has earned many awards over the years for his leadership in wine and the arts. He was awarded the New Zealand 1990 Commemoration Medal in 1990, and appointed an Officer of the Order of the British Empire, for services to the wine industry, in the 1995 Queen's Birthday Honours. He was made a fellow of the Wine Institute of New Zealand in 2000, and awarded an honorary doctorate by Lincoln University in 2001.
In 2012, Buck was inducted into the New Zealand Wine Hall of Fame. In the 2013 New Year Honours, Buck was appointed a Companion of the New Zealand Order of Merit for services to the wine industry and the arts. He was also one of only 150 attendees at the International Wine Trade Dinner at London's Vintners' Hall in 2013, held by the Worshipful Company of Vintners in celebration of the 650th anniversary of the Company's first Royal Charter.


Bill Guiry

William J. Guiry was an Irish Gaelic footballer. His championship career at senior level with the Limerick and Dublin county teams lasted two seasons from 1896 until 1897.
Guiry first played competitive football with the Commercials club in Limerick. He later joined the Kickhams club in Dublin and enjoyed championship success with both clubs.
Commercials represented Limerick in the 1896 championship, with Guiry lining out and winning a first All-Ireland medal. A year later he lined out with Dublin and won a second consecutive All-Ireland medal. Guiry also won a set of Munster and Leinster medals.


Carroll LeTellier

Carroll LeTellier (born 1928) was a US Army Major General and both a Korean War and Vietnam War combat veteran, serving with the US Army Corps of Engineers. As a Brigadier General (United States), he commanded ENGCOM, headquartered then in Frankfurt, Germany. In 1976, LeTellier retired from the military at the rank of Major general (United States) to a private civilian practice at Sverdrup Civil, Inc., the then 6th largest architecture and civil engineering firm in the United States, which he in turn retired from as vice president in 2002.
Education.
The Citadel, The Military College of South Carolina awarded Major general (United States) Carroll LeTellier a BS in civil engineering '49, MIT awarded LeTellier a Master in Civil Engineering, and The Citadel subsequently also awarded LeTellier a Doctorate in Civil Engineering (Honoris causa '99).
Awards and decorations.
LeTellier's military decorations include the Distinguished Service Medal (U.S. Army), 5 awards of the Legion of Merit, the Bronze Star Medal, and the Air Medal. The Major General was inducted into the mere 212 member US National Academy of Engineering.
See also.
List of members of the National Academy of Engineering (Civil)


Willor Lee Guilford

Willor Lee Guilford (born 1912) was an African American actress. She had substantial parts in several films including at least three Oscar Micheaux films.
Early life.
She was born January 13, 1912.
Career.
She portrayed the victim of a stalker in "Ten Minutes to Live". In the film, she receives a note from the villain telling her she will be killed in 10 minutes.
Later life.
Guilford opened a millinery shop in Brooklyn, New York (Willor's Hat Shop") after retiring from her film career. She eventually retired to Jacksonville, Florida.


Juan Orozco

Juan Orozco (born 14 April 1937 and died on February 15, 2020) Spanish luthier and guitar impresario who lived in New York from 1965 to 1995, where he had a famous guitar shop at 156, 56th Street in the 1970s to 1990s.
He is the third in a family of guitar makers (his father, Juan Orozco, built guitars in Spain, Uruguay and Brazil). He was actively involved in the development of classic guitars in the mid-1970s (starting as early as 1969) together with great Japanese luthiers like Matsuoka, Tamura, Masaki Sakurai and Yairi, who then developed guitars for Tama, Ibanez and Aria (at that time the small workshop where they worked was in the company Hoshino Gakki who own Tama and Ibanez). They also built guitars in the Kohno-Sakurai style (models #8, #10, #15) that were sold with the "Juan Orozco, Luthier" label. Later the Orozco guitars were equipped with a very characteristic headstock, different from the Fleta-style headstocks they had first. In the majority of user reviews, the majestic volume and sonorous bass sound of Juan Orozco guitars are emphasised.
Juan Orozco III is still active in the guitar business, in particular with the "Aranjuez" strings that he developed, and guitar cases. He also organised guitar concerts and is well known by many great guitar players and luthiers.
Achievements.
The granting of the cross of officer of the Order of Civil Merit on 24 June 1977.


2000 Commonwealth Avenue collapse

On January 25, 1971, a luxury condominium building under construction at 2000 Commonwealth Avenue in Brighton, Boston, Massachusetts, collapsed, killing 4 construction workers and injuring 30 others.
History.
The construction of the 2000 Commonwealth Avenue building began in autumn 1969. The building that collapsed was to have contained 133 condominium apartments. The collapse occurred the day before the building's scheduled "top out" day.
Collapse.
The building collapsed while concrete was being poured on the top floor of the building. Two-thirds of the building was destroyed by a progressive collapse. Approximately 100 men were working in or around the building.
A difficult and dangerous search by rescue workers, involving days of digging, led to the recovery from the building's basement of the bodies of the four workers who died in the collapse. The search was postponed for 36 hours while the Boston building commissioner and other experts confirmed the stability of the remaining structure, a delay that angered the coworkers and family members of the missing men.
The four workers killed were:
Papasedero was last seen after the collapse had begun entering the basement garage, where Tintindo and Cingolani, members of his crew, had been working, to search for them.
Cause.
Contributory causes of the collapse included lack of quality control and inspections, concrete weakened when left unprotected from cold weather, deficiencies in shoring and reinforcing bars and overly high construction loads on the roof slab. A commission of inquiry concluded that the primary causes of the collapse were lack of shoring and low concrete strength. On July 23, 1972, Controlled Demolition, Inc., imploded the unfinished building after the completion of the recovery effort.


Kathryn Walt Hall

Kathryn Walt Hall is an attorney, businesswoman and the American ambassador to Austria (1997-2001).
Hall earned an A.B. in Economics from the University of California, Berkeley, and a J.D. from the University of California, Hastings College of Law. She also has a joint MBA from UC California, Berkeley, and Columbia University. Hall began her public career as an Assistant City Attorney in Berkeley, California. She went on to work in the private sector including at Safeway Inc. and was the President of Kathryn Hall Vineyards, Inc., and of Walt Management, Inc., an inner-city housing and development company. Before becoming Ambassador, Hall was Managing Director and Partner of the investment firm Hall Financial Group, Inc. She returned to winemaking in 2001.


John Knibb

John Knibb (1650–1722) was an English clockmaker born in Claydon, Oxfordshire. He produced various clocks and watches including bracket clocks, lantern clocks, longcase clocks, and some wall-clocks, as well as building and maintaining several turret clocks. Even though his main market was catering to customers of modest means, he also dominated the higher-quality sector. Only six of Knibb's watches are known to survive.
Life.
Knibb was born in 1650, the sixth son of Thomas and Elizabeth Knibb of Claydon, Oxfordshire. He was cousin to the clock- and instrument maker Samuel Knibb (1625–70) and younger brother of the distinguished clock- and watchmaker Joseph Knibb (1640–1711).
In about 1664 Knibb moved from Claydon to Oxford to join his elder brother as either an apprentice or an assistant. In 1670 Samuel Knibb died and Joseph moved to London to replace him, leaving John in charge in Oxford. However, John was not a freeman of the City of Oxford, so all the clocks that he made still had to be signed "Joseph Knibb".
In 1672 Knibb applied to become a freeman of Oxford, and the Mayor and City Council proposed that he should be admitted for a fee of £30. Knibb considered this excessive so he asked Brome Whorwood, one of the two MPs for Oxford, to intervene. Under Whorwood's persuasion the Council reduced the fee to 20 marks (£13 6s 8d) and admitted Knibb as a freeman in April 1673.
Knibb and his wife Elizabeth had three sons and five daughters between 1679 and 1695. Four of their daughters predeceased them. Knibb died at Oxford in 1722, followed by his widow Elizabeth in 1726. They are buried at St Cross parish church with their four daughters.
John and Elizabeth were survived by their one remaining daughter and three sons, of whom the youngest, Joseph (born 1695), had been apprenticed to a London clockmaker in 1710. Knibb left young Joseph only one shilling in his will, because he had already inherited a legacy of £200 from his uncle Joseph, who died in 1711.
Knibb had several apprentices during his career. One was Samuel Aldworth, from Childrey, who was apprenticed to Knibb in 1673 and became a freeman of the city with his own clock business in 1689. In 1697 Joseph Knibb retired from London to Hanslope and Aldworth moved to London to succeed him. In 1703 Aldworth married into the Knibb extended family, his bride being Elizabeth Knibb, from Collingtree in Northamptonshire.
Oxford clockmaking in Knibb's time.
Knibb worked in Oxford at a time when clockmaking suddenly flourished in the city. During the Commonwealth of England Oxford had only two or three clockmakers and at times none of them had an apprentice. However, after the restoration of the Stuart monarchy Oxford's number of clockmakers' apprentices increased to five in 1670 and 12 for much of the 1680s. The number of qualified clockmakers with freedom of the city increased more slowly, peaking at seven early in the 1690s.
In the late 1680s and early 1690s apprentices were not replaced after they completed their seven years of training. The number of apprentices fell rapidly, and from the mid-1690s until the mid-1720s there were only ever one or two in the whole of Oxford. This was largely because the market was now fully supplied, sustaining between three and five freemen clockmakers for the corresponding three decades.
Knibb himself took a succession of 10 apprentices between 1673 and 1722. Between 1681 and 1688 he seems to have had three apprentices at the same time, as well as Aldworth as his journeyman.
Work.
In this busy period for clockmaking John Knibb was preeminent. When Joseph moved to London in 1670, John took more responsibility for the business in Oxford. The premises that Knibb took over from his brother were a tenement on the south side of Holywell Street leased from Merton College, Oxford, built in the shadow of the city walls on what had been the town ditch.
Knibb produced bracket clocks, lantern clocks, longcase clocks, and wall clocks. His products were more numerous than his Oxford competitors. He catered for the less expensive segment of the market but he also dominated the higher quality part of the market.
Knibb built and maintained turret clocks. From 1673 until his death in 1722 he maintained the turret clock at Wadham College, Oxford that was probably made by his brother Joseph. He built the turret clock for St John's College, Oxford in 1690 and repaired the clock at St Bartholomew's parish church, Yarnton in 1703.
Six of Knibb's watches are known to survive. One verge watch made in about 1690 is in the Clockmakers' Museum at the Guildhall, London. The Museum of the History of Science, Oxford has three that were also made in about 1690. The collection at Oxford includes one of Knibb's bracket clocks, two of his longcase clocks and one of his wall clocks.
After his brother Joseph died in 1711, his will proved in 1712 bequeathed his farm at Hanslope to Knibb. However, only one clock is known with the inscription "John Knibb Hanslap", so it appears that Knibb continued to work almost exclusively in Oxford.
Civic and social life.
In 1686 Knibb was appointed a member of Oxford City Council. He was elected as one of the Bailiffs in 1688 and from 1690 to 1696. He was elected as one of the Mayor's assistants in 1697, and Keykeeper and assistant member of the Mayor's council in 1700. Knibb was elected Mayor of Oxford twice, in 1698 and 1710. In 1716 he was elected Alderman.
Knibb's friends included the antiquarians Anthony Wood and Thomas Hearne. In 1716 Hearne wrote "This Nibb is a man of so little understanding that he was never known to laugh". However, on learning of Knibb's death in 1722 Hearne wrote that Knibb was "an old, quiet, harmless Man abt. 4 score years of Age."
Blue plaque.
On 26 September 2010 the Oxfordshire Blue Plaques Board unveiled a blue plaque at Claydon to Samuel, Joseph and John Knibb.


Magnetic coupling

A magnetic coupling is a coupling that transfers torque from one shaft to another, but using a magnetic field rather than a physical mechanical connection.
Magnetic shaft couplings are most often used for liquid pumps and propeller systems, since a static, physical barrier can be placed between the two shafts to separate the fluid from the motor operating in air. Magnetic shaft couplings preclude the use of shaft seals, which eventually wear out and fail from the sliding of two surfaces against each another. Magnetic couplings are also used for ease of maintenance on systems that typically require precision alignment, when physical shaft couplings are used, since they allow a greater off axis error between the motor and driven shaft.
Applications.
Some diver propulsion vehicles and remotely operated underwater vehicles use magnetic coupling
to transfer torque from the electric motor to the prop. Magnetic gearing is also being explored for use in utility scale wind turbines as a means of enhancing reliability.
The magnetic coupling has several advantages over a traditional stuffing box.
Some aquarium pumps are magnetic drive pumps -- they use magnetic coupling between the motor on the dry side of an aquarium wall and the propeller/impeller in the water on the other side of that aquarium wall.
With two face-to-face magnetized disks -- one driving magnet on the dry side, and another driven magnet on the wet side of the glass -- there are two options for designing the magnetic pattern on each disk.
One option balances the (attractive) section that transfers torque, with magnetic repulsion near the axis, to nearly cancel out axial load.
The other option designs the magnetic pattern to maximize the torque, and uses a mechanical thrust bearing to resist the attraction between the magnetized disks.
A magnetic stirrer is another example of magnetic coupling.
Magnetic couplings are often synchronous (output shaft speed equals input shaft speed, or 1:1).
The first few gears in the geartrain of an Omega Megasonic wristwatch have no teeth; instead magnetic north and south poles on neighboring gears act like the teeth and trough of neighboring spur gears, as each gear drives the next gear in the chain.
Such magnetic gears, like spur gears, always have gear ratios as the ratios of small integers.
More sophisticated magnetic gearing uses pole pieces to modulate the magnetic field; they can be designed to have gear ratios from 1.01:1 to 1000:1.