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|Nºmero de publicaciµn
|Tipo de publicaciµn
|Nºmero de solicitud
|Fecha de publicaciµn
|9 Ene 2007
|Fecha de presentaciµn
|4 Ago 2003
|Fecha de prioridad
|7 Sep 1999
|TambiÕn publicado como
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|Neil J. Goldfine, Darrell E. Schlicker, David C. Clark, Karen E. Walrath, Volker Weiss, William M. Chepolis, Andrew P. Washabaugh, Vladimir A. Zilberstein, Vladimir Tsukernik
|Cesionario original
|Jentek Sensors, Inc.
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|BiBTeX, EndNote, RefMan
|Citas de patentes (32), Citada por (14), Clasificaciones (18), Eventos legales (3)
|Enlaces externos: USPTO, Cesiµn de USPTO, Espacenet
This application is a divisional of U.S. application Ser. No. 09/666,879, filed Sep. 20, 2000 now U.S. Pat. No. 6,657,429, which is a Continuation-in-Part of U.S. application Ser. No. 09/656,723 filed Sep. 7, 2000 now abandoned which claims the benefit of U.S. Provisional Application No. 60/203,744 filed May 12, 2000, No. 60/155,038 filed Sep. 20, 1999 and U.S. Provisional Application No. 60/152,828 filed Sep. 7, 1999; which claims the benefit of U.S. application Ser. No. 09/350,502, filed Jul. 9, 1999, now U.S. Pat. No. 6,198,279, which is a Divisional of U.S. application Ser. No. 09/122,980 filed Jul. 27, 1998, now U.S. Pat. No. 5,966,011, which is a Divisional of U.S. application Ser. No. 08/702,276 filed Aug. 23, 1996, now U.S. Pat. No. 5,793,206 which claims the benefit of U.S. Provisional Application No. 60/002,804 filed Aug. 25, 1995; and of U.S. application Ser. No. 09/039,190 filed Mar. 13, 1998 which claims the benefit of U.S. Provisional Application No. 60/041,958 filed Apr. 3, 1997 and No. 60/039,622 filed Mar. 13, 1997; and of U.S. application Ser. No. 09/182,693 filed Oct. 29, 1998, now U.S. Pat. No. 6,188,218, which claims the benefit of U.S. Provisional Application No. 60/063,534 filed Oct. 29, 1997, which claims the benefit of U.S. Provisional Application No. 60/069,604 filed Dec. 15, 1997, which claims the benefit of U.S. Provisional Application No. 60/104,526 filed Oct. 16, 1998. The entire teachings of the above applications and patents are incorporated herein by reference.
The invention was supported, in whole or in part, by a Contract Number DTRS57-96-C-00108 from the Department of Transportation, Federal Aviation Administration, by Contract Number N00421-97-C-1120 from the Department of the Navy. The Government has certain rights in the invention.
The technical field of this invention is that of nondestructive materials characterization, particularly quantitative, model-based characterization of surface, near-surface, and bulk material condition for flat and curved parts or components using eddy-current sensors. Characterization of bulk material condition includes (1) measurement of changes in material state caused by fatigue damage, creep damage, thermal exposure, or plastic deformation; (2) assessment of residual stresses and applied loads; and (3) assessment of processing-related conditions, for example from shot peening, roll burnishing, thermal-spray coating, or heat treatment. It also includes measurements characterizing material, such as alloy type, and material states, such as porosity and temperature. Characterization of surface and near-surface conditions includes measurements of surface roughness, displacement or changes in relative position, coating thickness, and coating condition. Each of these also includes detection of electromagnetic property changes associated with single or multiple cracks. Spatially periodic field eddy-current sensors have been used to measure foil thickness, characterize coatings, and measure porosity, as well as to measure property profiles as a function of depth into a part, as disclosed in U.S. Pat. Nos. 5,015,951 and 5,453,689.
Conventional eddy-current sensing involves the excitation of a conducting winding, the primary, with an electric current source of prescribed frequency. This produces a time-varying magnetic field at the same frequency, which in turn is detected with a sensing winding, the secondary. The spatial distribution of the magnetic field and the field measured by the secondary is influenced by the proximity and physical properties (electrical conductivity and magnetic permeability) of nearby materials. When the sensor is intentionally placed in close proximity to a test material, the physical properties of the material can be deduced from measurements of the impedance between the primary and secondary windings. Traditionally, scanning of eddy-current sensors across the material surface is then used to detect flaws, such as cracks.
For the inspection of structural members in an aircraft, power plant, etc., it is desirable to detect and monitor material damage, crack initiation and crack growth due to fatigue, creep, stress corrosion cracking, etc. in the earliest stages possible in order to verify the integrity of the structure. This is particularly critical for aging aircraft, where military and commercial aircraft are being flown well beyond their original design lives. This requires increased inspection, maintenance, and repair of aircraft components, which also leads to escalating costs. For example, the useful life of the current inventory of aircraft in the U.S. Air Force (e.g., T-38, F-16, C-130E/H, A-10, AC/RC/KC-135, U-2, E-3, B-1B, B-52H) is being extended an additional 25 years at least [Air Force Association, 1997, Committee, 1997]. Similar inspection capability requirements also apply to the lifetime extension of engine components [Goldfine, 1998].
Safely supporting life extension for structures requires both rapid and cost effective inspection capabilities. The necessary inspection capabilities include rapid mapping of fatigue damage and hidden corrosion over wide areas, reduced requirements for calibration and field standards, monitoring of difficult-to-access locations without disassembly, continuous on-line monitoring for crack initiation and growth, detection of cracks beneath multiple layers of material (e.g., second layer crack detection), and earlier detection of cracks beneath fastener heads with fewer false alarms. In general, each inspection capability requires a different sensor configuration.
The use of eddy-current sensors for inspection of critical locations is an integral component of the damage tolerance and retirement for cause methods used for commercial and military aircraft. The acceptance and successful implementation of these methods over the last three decades has enabled life extension and safer operation for numerous aircraft. The corresponding accumulation of fatigue damage in critical structural members of these aging aircraft, however, is an increasingly complex and continuing high priority problem. Many components that were originally designed to last the design life of the aircraft without experiencing cracking (i.e., safe life components) are now failing in service, both because aircraft remain in service beyond original design life and, for military aircraft, because expanded mission requirements expose structures to unanticipated loading scenarios. New life extension programs and recommended repair and replacement activities are often excessively burdensome because of limitations in technology available today for fatigue detection and assessment. Managers of the Aircraft Structural Integrity Program (ASIP) are often faced with difficult decisions to either replace components on a fleet-wide basis or introduce costly inspection programs.
Furthermore, there is growing evidence that (1) multiple site damage or multiple element damage may compromise fail safety in older aircraft, and (2) significant fatigue damage, with subsequent formation of cracks, may occur at locations not considered critical in original fatigue evaluations. In application of damage tolerance, inspection schedules are often overly conservative because of limitations in fatigue detection capability for early stage damage. Even so, limited inspection reliability has led to numerous commercial and military component failures.
A better understanding of crack initiation and short crack growth behavior also affects both the formulation of damage tolerance methodologies and design modifications on new aircraft and aging aircraft. For safe-life components, designed to last the life of the aircraft, no inspection requirements are typically planned for the first design life. Life extension programs have introduced requirements to inspect these "safe-life" components in service since they are now operating beyond the original design life. However, there are also numerous examples of components originally designed on a safe-life basis that have failed prior to or near their originally specified design life on both military and commercial aircraft.
For safe-life components that must now be managed by damage tolerance methods, periodic inspections are generally far more costly than for components originally designed with planned inspections. Often the highest cost is associated with disassembly and surface preparation. Additionally, readiness of the fleet is directly limited by time out of service and reduced mission envelopes as aircraft age and inspection requirements become more burdensome. Furthermore, the later an inspection uncovers fatigue damage the more costly and extensive the repair, or the more likely replacement is required. Thus, inspection of these locations without disassembly and surface preparation is of significant advantage; also, the capability to detect fatigue damage at early stages can provide alternatives for component repair (such as minimal material removal and shotpeening) that will permit life extension at a lower cost than current practice.
In general, fatigue damage in metals progresses through distinct stages. These stages can be characterized as follows [S. Suresh, 1998]: (1) substructural and microstructural changes which cause nucleation of permanent damage, (2) creation of microscopic cracks, (3) growth and coalescence of these microscopic flaws to form 'dominant' cracks, (4) stable propagation of the dominant macrocrack, and (5) structural instability or complete fracture.
Although there are differences of opinion within the fatigue analysis community, Suresh defines the third stage as the demarcation between crack initiation and propagation. Thus, the first two of the above stages and at least the initial phase of Stage 3 are generally thought of, from a practical engineering perspective, as the crack initiation phase.
In Stage 1, microplastic strains develop at the surface even at nominal stresses in the elastic range. Plastic deformation is associated with movement of linear defects known as dislocations. In a given load cycle, a microscopic step can form at the surface as a result of localized slip forming a "slip line". These slip lines appear as parallel lines or bands commonly called "persistent slip bands" (PSBs). Slip band intrusions become stress concentration sites where microcracks can develop.
Historically, X-ray diffraction and electrical resistivity are among the few nondestructive methods that have been explored for detection of fatigue damage in the initiation stages. X-ray diffraction methods for detection of fatigue damage prior to microcracking have been investigated since the 1930's [Regler, 1937; Regler, 1939]. In these tests, fatigue damage was found to be related to diffraction line broadening. More recently Taira [1966], Kramer [1974] and Weiss and Oshida [1984] have further developed the X-ray diffraction method. They proposed a self-referencing system for characterization of damage, namely the ratio of dislocation densities as measured 150 micrometers below the surface to that measured 10–50 micrometers below the surface. The data obtained to date suggest that in high strength aluminum alloys the probability of fatigue failure is zero for dislocation density ratios of 0.6 or below. However, it is generally impractical to make such measurements in the field.
Electrical resistivity also provides a potential indication of cumulative fatigue damage. This is supported by theory, since an increase in dislocation density results in an increase in electrical resistivity. Estimates suggest that, in the case of aluminum, depending on the increase in the density of dislocations in the fatigue-damage zone, the resistivity in the fatigue-affected region may increase by up to 1% prior to formation of microcracks. These estimates are based on dislocation densities in the fatigue-damage zone up to between 2(1011 cm−2 to 1012 cm−2 and a resistivity factor of 3.3(10−19 ((cm3 [Friedel, 1964].
Aspects of the inventions described herein involve novel inductive sensors for the measurement of the near surface properties of conducting and magnetic materials. These sensors use novel winding geometries that promote accurate modeling of the response, eliminate many of the undesired behavior in the response of the sensing elements in existing sensors, provide increased depth of sensitivity by eliminating the coupling of spatial magnetic field modes that do not penetrate deep into the material under test (MUT), and provide enhanced sensitivity for crack detection, localization, crack orientation, and length characterization. The focus is specifically on material characterization and also the detection and monitoring of precrack fatigue damage, as well as detection and monitoring of cracks, and other material degradation from testing or service exposure.
Methods are described for determining anisotropic material property variations with spatially periodic field eddy current sensors. Sensors with extended portions for forming the magnetic field, when placed in proximity to a MUT, provide a directionally dependent measure of the electromagnetic properties of the MUT, such as the electrical conductivity or magnetic permeability. Measurements of the material properties with varying orientations of the sensor with respect to the material property variation directions then provides a technique for determining the properties of interest.
For example, when measurements of the electrical conductivity are made in orthogonal directions on roller burnished metals such as aluminum, the anisotropy associated with the cold working and the quality of the process can be determined. Similarly, measurements of the magnetic permeability in orthogonal directions can be used to ascertain the level of fatigue damage, thermal damage, and stress level. The orientation and value of the maximum and minimum electrical property values can be determined from a continuous rotation of a spatially periodic field eddy-current sensor and can be used to determine the direction and magnitude of an applied load or the orientation and depth of a crack. Multiple frequency excitations can be used to vary the effective depth of penetration of the magnetic field into the test material, thereby extending the capability to measure electrical property variations with depth from the surface.
Novel inspection methods are described herein that relate to new surface mountable eddy-current sensors. These thin, conformable sensors can be mounted on conducting or magnetic materials, metals for example, and used to monitor crack initiation and growth by periodically measuring the sensor response to the material properties beneath the sensor footprint. Spatially periodic field eddy-current sensors, such as the Meandering Winding Magnetometer (MWM), can provide absolute properties measurements using single sensing elements or arrays of sensing elements (MWM-Arrays) located throughout the primary winding meanders. In one embodiment, one of the sensing elements in an array of sensing elements can be located in a place of minimal damage and can be used a reference for the measurement. The change in the electrical property exceeding the background noise level can also be used as an indicator for substantial changes in the MUT condition. In another embodiment, one of the elements can be left in "air" so that an "air" measurement can be used as the reference. In another embodiment of this method, the temperature of the MUT can be varied as a method of verifying the response of the individual sensing elements. The sensing elements can also be calibrated from the measured responses at several temperature levels and knowledge of the temperature dependence of the MUT properties. Alternatively, the use of a temperature sensor can allow the measurements to be compensated for temperature variations. While windings are typically used as the sensing elements, to provide an absolute or differential measurement of the material properties, other embodiments include the use of magnetoresistive elements and SQUIDS.
In another embodiment, the capability of a spatially periodic field eddy current sensor to provide reliable measurements with a sufficiently large gap (stand off) between the surfaces also provides the capability to monitor initiation of stress corrosion cracking and propagation of stress corrosion cracks. The MWM sensor or MWM-Arrays should not modify the environment that is causing the stress corrosion cracking and, for example, do not create tight crevices between the monitored surface and the MWM. Additionally, in one embodiment the substrate of the MWM sensor perforated between the windings further minimizes any differences between the bulk environment and the environment in the gap between the MWM and the measured surface. Also, in another embodiment a deep penetration surface mounted MWM or MWM-Array can be mounted on the inside skin to monitor hidden corrosion or cracking on the opposite side of the skin. For example, second or third layer corrosion and cracking can be monitored with an MWM-Array mounted on the inside of the third layer. Guides or conduits can be used to permit scanning eddy-current sensors to inspect through the permanently mounted eddy-current sensor. Furthermore, remote actuators can be used to vary the location of the drive and sense windings relative to the MUT.
When mounted to the test article, the sensor can be flexible to conform to the shape of the surface of the MUT. The sensor may also be mounted in difficult-to-access locations where only the connection leads or cables for connecting to the sensor leads are readily accessible. An example would be the mounting of a sensor between layers of materials or beneath fasteners such as those used in aircraft. Sealant materials can provide mechanical support and environmental protection for the sensor. In addition, electronics components can be placed near the sensing elements to provide signal amplification from the sensor. The mounted electromagnetic sensor may be a dielectrometer. Additional sensors can also be used in conjunction with the mounted electromagnetic sensor, such as a strain gauge or a temperature gauge.
Methods for characterizing MUT property variations over wide areas. Scanning of spatially periodic field eddy-current sensors over a surface permits the creation of images of the absolute material properties beneath the sensor. Patterns in the images of the properties, such as the electrical conductivity, can indicate locations of damage. Furthermore, multiple frequency or multiple orientation measurements can be used to characterize the damage, such as distinguishing cracks from fretting damage, determining crack size or morphology, detecting hidden corrosion or cracks, determining properties of coating layers, and differentiating damage from manufacturing conditions. The capability to create images of damage allows the extent of the damage to be identified so that the size and type of patches can be determined. For areas of wide-spread or distributed fatigue damage, identifying locations of damage can be used to schedule future inspections or repair and replacement actions. In one embodiment, the flexible sensor can be mounted to a compliant layer that is affixed to a substrate that approximates the shape of the surface of the MUT. In another embodiment, two or more sensing elements can be situated to pass over the same flaw with a single scan. The signals from the individual sensing elements can then be processed and combined to enhance the flaw signal.
The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
A description of preferred embodiments of the invention follows. To safely support life extension for aging structures and to reduce weight and maintenance/inspection costs for new structures requires both rapid and cost effective inspection capabilities. In particular, continuous monitoring of crack initiation and growth requires the permanent mounting of sensors to the component being monitored and severely limits the usefulness of calibration or reference standards, especially when placed in difficult-to-access locations on aging or new structures.
Permanent and surface mounting of conventional eddy-current sensors is not performed. One reason for this is the calibration requirements for the measurements and another is the variability between probes. Conventional eddy-current techniques require varying the proximity of the sensor (or lift-off) to the test material or reference part by rocking the sensor back and forth or scanning across a surface to configure the equipment settings and display. For example, for crack detection the lift-off variations is generally displayed as a horizontal line, running from right to left, so that cracks or other material property variations appear on the vertical axis. Affixing or mounting the sensors against a test surface precludes this calibration routine. The probe-to-probe variability of conventional eddy-current sensors prevents calibrating with one sensor and then reconnecting the instrumentation to a second (e.g., mounted) sensor for the test material measurements. Measured signal responses from nominally identical probes having inductance variations less than 2% have signal variations greater than 35% [Auld, 1999]. These shortcomings are overcome with spatially periodic field eddy-current sensors, as described herein, that provide absolute property measurements and are reproduced reliably using micro-fabrication techniques. Calibrations can also be performed with duplicate spatially periodic field sensors using the response in air or on reference parts prior to making the connection with the surface mounted sensor.
The capability to characterize fatigue damage in structural materials, along with the continuous monitoring of crack initiation and growth, has been demonstrated. A novel eddy-current sensor suitable for these measurements, the Meandering Winding Magnetometer Array (MWM™-Array), is described in U.S. Pat. Nos. 5,015,951, 5,453,689, and 5,793,206. The MWM is a "planar," conformable eddy-current sensor that was designed to support quantitative and autonomous data interpretation methods. These methods, called grid measurement methods, permit crack detection on curved surfaces without the use of crack standards, and provide quantitative images of absolute electrical properties (conductivity and permeability) and coating thickness without requiring field reference standards (i.e., calibration is performed in "air," away from conducting surfaces). The use of the MWM-Array for fatigue mapping and on-line fatigue monitoring has also been described [Goldfine, 1998 NASA]. This inspection capability is suitable for on-line fatigue tests for coupons and complex components, as well as for monitoring of difficult-to-access locations on both military and commercial aircraft.
The MWM structure can be produced using micro-fabrication techniques typically employed in integrated circuit and flexible circuit manufacture. This results in highly reliable and highly repeatable (i.e., essentially identical) sensors, which has inherent advantages over the coils used in conventional eddy-current sensors. As indicated by Auld and Moulder, for conventional eddy-current sensors "nominally identical probes have been found to give signals that differ by as much as 35%, even though the probe inductances were identical to better than 2%" [Auld, 1999]. This lack of reproducibility with conventional coils introduces severe requirements for calibration of the sensors (e.g., matched sensor/calibration block sets). In contrast, duplicate MWM sensor tips have nearly identical magnetic field distributions around the windings as standard micro-fabrication (etching) techniques have both high spatial reproducibility and resolution. As the sensor was also designed to produce a spatially periodic magnetic field in the material under test (MUT), the sensor response can be accurately modeled which dramatically reduces calibration requirements. For example, in some situations an "air calibration" can be used to measure an absolute electrical conductivity without calibration standards, which makes the MWM sensor geometry well-suited to surface mounted or embedded applications where calibration requirements will be necessarily relaxed.
An efficient method for converting the response of the MWM sensor into material or geometric properties is to use grid measurement methods. These methods map the magnitude and phase of the sensor impedance into the properties to be determined and provide for a real-time measurement capability. The measurement grids are two-dimensional databases that can be visualized as "grids" that relate two measured parameters to two unknowns, such as the conductivity and lift-off (where lift-off is defined as the proximity of the MUT to the plane of the MWM windings). For the characterization of coatings or surface layer properties, three-dimensional versions of the measurement grids can be used. Alternatively, the surface layer parameters can be determined from numerical algorithms that minimize the least-squares error between the measurements and the predicted responses from the sensor.
An advantage of the measurement grid method is that it allows for real-time measurements of the absolute electrical properties of the material. The database of the sensor responses can be generated prior to the data acquisition on the part itself, so that only table lookup operation, which is relatively fast, needs to be performed. Furthermore, grids can be generated for the individual elements in an array so that each individual element can be lift-off compensated to provide absolute property measurements, such as the electrical conductivity. This again reduces the need for extensive calibration standards. In contrast, conventional eddy-current methods that use empirical correlation tables that relate the amplitude and phase of a lift-off compensated signal to parameters or properties of interest, such as crack size or hardness, require extensive calibrations and instrument preparation.
Similar two-dimensional images of the measured conductivity have been obtained on actual military components.
Fatigue damage can also create variations in the magnetic permeability, as indicated in
This ability to map the spatial extent of the wide area fatigue provides information that can be used to improve the selection of patch location and size, thereby potentially improving the reliability of the repairs and reducing follow-on maintenance costs. The MWM measured conductivity information may also be used to identify specific regions that require fastener inspections, as well as to support inspection, maintenance scheduling and redesign efforts. This is important because the locations of these areas are not always intuitive, since the structural response is affected by design features such as window edge stiffeners, lap joints, and doublers, and by maintenance features such as patches and repairs in sometimes unforeseen ways.
Surface mounted MWM-Arrays have also demonstrated an on-line capability to monitor cumulative fatigue damage during load cycling.
The ability to continuously monitor fatigue specimens while being loaded provides a capability to create samples with very early stage fatigue damage.
SEM examinations confirmed the presence and locations of cracks in the specimens. SEM examinations of Specimen #34 revealed a few microcracks, ranging from 0.0004 to 0.0036 inches (10 to 90 (m) on the surface of the hole monitored by MWM. The 0.0036 inch long intermittent crack was in the area monitored by Elements 3 and 4 of the MWM. A crack in this location is consistent with the MWM response of
The reliable detection of the onset of fatigue damage and the number of cycles to crack initiation, Ni, can be performed automatically using trend detection algorithms. An example detection algorithm is to use a simple hypothesis test to build a first set of statistics (e.g., standard deviations) for the no damage MWM conductivity data at the beginning of the test and also a second set of statistics for a moving window of most recent data. This grouping of data is illustrated in
Another aspect of the invention described here relates to unique geometries for fatigue specimens that intentionally shape the stress distribution so that the damage initiation sites will lie within the area under inspection by a surface mounted eddy-current sensor.
With a traditional dogbone design, fatigue damage starts in the middle of the specimen but is not localized along the length of the samples. Thus, there is no guarantee that the fatigue damage will initiate beneath the surface mounted sensor. The new specimen geometries described here, and illustrated in
To provide complete coverage when the sensor is scanned across a part or when a crack propagates across the sensor, perpendicular to the extended portions of the primary winding, secondary elements 58 in adjacent meanders of the primary are offset along the length of the meander. The dummy elements 60 are used to maintain the periodic symmetry of the magnetic field and the extension elements 62 are used to minimize differences in the coupling of the magnetic field to the various sensing elements, as described in patent application Ser. No. 09/182,693. Additional primary winding meander loops, which only contain dummy elements, can also be placed at the edges of the sensor to help maintain the periodicity of the magnetic field for the sensing elements nearest the sensor edges. The secondary elements are set back from the cross-connection portions 53 of the primary winding meanders to minimize end effects on the measurements.
The connection leads 64 to the secondary elements are perpendicular to the primary winding meanders, which creates a "T" shape and necessitates the use of a multi-layer structure in fabricating the sensor. The sensor of
An advantage of the sensor of
The rosette configuration is most useful for crack detection and location around circularly symmetric regions, such as around fasteners. The rosette configuration can also be used in areas where the stress distribution and the crack initiation point and growth direction may not be known because of complex component geometry or service related repairs.
The MWM-Array configurations of
The MWM sensors embodied in
The sensors can also be embedded between layers of a structure, such as between layers of a lap joint or under repairs using composites or metal doublers, possibly with a sealant or other fillers to support compressive loads. This is illustrated in the cross-sectional view of
Since processing of the measured responses through the measurement grids provides the capability for each sensing element to be individually lift-off compensated and access to each element is not required for calibration, the sensor can be covered with a top coat of sealant to provide protection from any hazardous environments. Furthermore, the sensor can intentionally be set off a surface, or fabricated with a porous (or liberally perforated. e.g. at 249 in
These configurations, particularly when applied in a surface mount application, provide new capabilities for fatigue damage monitoring. For example, there is a stated requirement in both military and commercial sectors to more accurately determine the number of cycles to crack initiation, Ni, in fatigue test coupons and component tests. For coupons, this is necessary to determine the fatigue behavior of new alloys and to qualify production runs for materials used in aircraft structures. For fatigue tests of complex structures, determination of both the number of cycles to crack initiation and monitoring of crack propagation and crack propagation rates, da/dN (depth vs. cycles) and dl/dN (length vs. cycles), is required and would provide essential information for both aging aircraft management and newer aircraft design and modification. When cracks initiate in difficult-to-access locations, however, crack propagation rates can not be determined during fatigue testing. Thus, either costly disassembly is required during fatigue tests, or very conservative damage tolerance-based inspection scheduling for in-service aircraft will result. Surface mounting of the sensors substantially reduces the disassembly requirement and allows for more periodic inspections.
This sensor also uses a single primary winding that extends beyond the sensing elements in the x and y directions. This has the specific advantages of eliminating the problem of cross-coupling between individually driven sensing elements and reducing parasitic effects at the edges of the sensor. These parasitic effects are further reduced by the introduction of passive, dummy elements that maintain the periodicity of the sensor geometry. These elements are illustrated in
Furthermore, the distance between the sensing elements and the primary (drive) winding is large enough to minimize coupling of short spatial wavelength magnetic field modes. As a result, the sensing element response is primarily sensitive to the dominant periodic mode. This produces improved depth of sensitivity to the properties of an MUT.
The design of the sensor in
In order to maintain the symmetry for the sensing elements, multiple layers are required for the winding patterns. In
Although the use of multilayer sensors and sensor arrays is widespread in the literature, one unique approach here is the offset combination of absolute and differential elements within a meandering winding structure that provides a spatially periodic imposed magnetic field and has been designed to minimize unmodeled parasitic effects. Specific advantages of this design are that (1) it allows complete coverage with both types of sensing elements when the array is scanned over an MUT, (2) the response of the individual elements can be accurately modeled, allowing quantitative measurements of the MUT properties and proximity, and (3) it provides increased depth of sensitivity. In particular, while U.S. Pat. No. 5,793,206 teaches of the use of numerous sensing elements within each meander of a primary winding, the design of
This combination of both differential and absolute sensing elements within the same footprint of a meandering primary winding is novel and provides new imaging capabilities. The differential elements are sensitive to slight variations in the material properties or proximity while the absolute elements provide the base properties and are less sensitive to small property variations. In one embodiment, the raw differential sensor measurements can be combined with one, some or all of the raw absolute measurements to provide another method for creating a two-dimensional mapping of the absolute material properties (including layer thicknesses, dimensions of an object being imaged, and/or other properties) and proximity. In another embodiment, the property and proximity information obtained from the absolute measurements can be used as inputs for models that relate the differential response to absolute property variations.
One of the issues with planar eddy-current sensors is the placement of the current return for the primary winding. Often the ends of the primary winding are spatially distant from one another, which creates an extraneous and large inductive loop that can influence the measurements. One embodiment for a layout for a primary winding that reduces the effect of this inductive loop is shown in
Grid measurement methods can also be applied to multi-layer sensor constructs. For example,
An alternative method of making connections to the various components of the primary winding elements is shown in
An embodiment of an MWM-Array with multiple sensing elements is shown in
Another embodiment for a layout of the planar primary winding reduces the effect of the primary winding inductive loop as illustrated in
It is also possible to calibrate and verify the integrity of the surface mounted MWM-Arrays by utilizing the accurately modeled and reproducible array geometry and measurement grids so that extensive sets of reference parts are not required. An initial "air" calibration is performed prior to mounting on the surface. This involves taking a measurement in air, for each array element, and then storing the calibration information (e.g., in a computer) for later reference after mounting the sensors. After the sensor has been mounted to a surface, the instrument and probe electronics can be calibrated by connecting to a duplicate sensor so that an air calibration can be performed. After connecting the surface mounted sensor to the instrumentation, the sensor operation and calibration can be verified by measuring the lift-off at each element. The sensor is not operating properly if the lift-off readings are too high, which may result from the sensor being detached from the surface, or if the measurement points no longer fall on a measurement grid, which generally corresponds to a lack of continuity for one of the windings. A final verification involves comparing baseline measurements to other measurement locations that are not expected to have fatigue damage or cracks. This reference comparison can verify sensor operation and may assist in compensating for noise variables such as temperature drift. This may involve using elements of the array that are distant from the areas of high stress concentration.
The electrical conductivity of many test materials is also temperature dependent. This temperature dependence is usually a noise factor that requires a correction to the data. For example,
Thermally induced changes in the electrical conductivity also provide a mechanism for testing the integrity of the sensor. Heating the test material locally, in the vicinity of the MWM-Array should only lead to a change in conductivity, not lift-off, when the array is compressed against the part. Monitoring the conductivity changes with temperature, without significant lift-off changes then verifies the calibration of the sensor and also that the sensor elements themselves are intact.
Another component of the life extension program for aircraft is the rapid and cost-effective inspection of engine components such as the slots of gas turbine disks and spools. Cracks often form in regions of fretting damage. The fretting damage often leads to false positive crack detections with conventional eddy-current sensors, which severely limits the usefulness of conventional eddy-current sensors in this inspection. For a number of disks/spools, ultrasonic (UT) inspection is the current standard inspection method. The current UT threshold for "reliable" detection of cracks in fretting damage regions is thought to be between 0.150 and 0.250 inches but there is an ongoing need to reliably detect smaller cracks, possibly as small as 0.060 to 0.080 inches in length. The JENTEK GridStation (System with the conformable MWM eddy-current sensor and grid measurement methods offers the capability to detect these small cracks in fretting regions, while eliminating the need for crack calibration standards other than to verify performance. Calibration can be performed with the sensor in the middle of any slot on the engine disk. A scan of this slot is then performed first to verify that no crack existed at the calibration location. Then all slots on a disk are inspected without recalibration.
For the inspection of nonmagnetic disks, such as titanium disks, absolute electrical conductivity and proximity (lift-off) measurements can be performed with MWM sensors. When a crack within a slot is encountered, it manifests itself by a distinct and repeatable drop in conductivity.
Table 1 compares the findings of the MWM inspections with the UT inspection. The UT report identified rejected indications (>30%) in nine of the 46 slots (slots # 9, 10, 11, 13, 22, 34, 35, 36, and 45). The disk slots had regions of fretting damage and, according to the UT inspection report, some of the slots contained cracks in the fretting damage regions. In contrast, the MWM with Grid methods reliably detected cracks within fretting damage regions in 14 slots, including all nine slots with rejected UT indications and five additional slots (slot # 1, 8, 14, 23, and 41). For verification, the well-known procedure for taking acetate replicas, that provide a "fingerprint" image of the surface, was adapted for the characterization of the surface condition within the slots. These replicas confirmed the MWM findings and showed images of cracks in fretting damage regions.
Comparison of crack detection by MWM with reported UT
indications for an F110 Stage 2 fan disk.
Crack Length as
Distance from slot
edge to the nearest
by Replicas
crack tip
Yes (E)
0.16 in.
0.23 in.
0.05 in.
0.16 in.
No (A)
No cracks
No cracks
No (A)
~0.015 in.
0.26 in.
No (A)
0.045 in.
(0.20 in.
>0.12 in.
No (A)
No cracks
No cracks
Yes (E)
0.16 in.
0.32 in.
Yes (E)
0.20 in.
0.26 in.
Yes (E)
0.21 in.
0.2 in.
Yes (E)
0.22 in.
0.28 in.
No (A)
0.44 in.
<0.015 in.
Yes (E)
0.28 in.
0.20 in.
Yes (E)
0.13 in.
0.22 in.
No (A)
Possibly 2
0.22 in.
adjacent cracks
(combined length
(0.03 in.)
0.005 to 0.015 in.
0.13 in.
long intermittent
cracks over 0.15
No (A)
No cracks
No cracks
No (A)
No cracks
No cracks
No (A)
Possibly one 0.03
0.29 in.
in. crack?
No (A)
No cracks
No cracks
No (A)
No cracks
No cracks
0.44 in.
0.18 in.
0.19 in
0.16 in.
?No (A)
0.005 to
0.29 in.
0.025 in. long
cracks over
Two adjacent
0.26 in.
cracks (comb.
length (0.04 in.)
plus two 0.05 in.
Possibly 2
cracks, 0.02 in.
each, about 0.1
in. apart
(0. 34 in.
0.25 in.
(0. 440 in
0.16 in.
Not replicated
Not replicated
0.15 in.
0.36 in.
0.15 in.
0.21 in.
A - accept;
E - evaluate (subject to an evaluation for repair/retire decisions);
ART - accept on retest;
ERT - evaluate on retest. These decisions depend on the threshold settings in the application module.
Additional measurements were also performed to illustrate the use of an encoder for determining the position in a slot and sequential thresholds for determining the acceptability of a disk slot. A typical set of measurement scan results is illustrated in
In these tests the protocol for the acceptance decision for each slot is based on a sequential decision process. Two thresholds were used in this process and are denoted by the labels A1 and A2 in
These thresholds are based on statistics for the disks being measured and the training set population. In this case, the threshold level A1 was set to provide an Evaluate decision for a 0.16 inch long crack while the threshold level A2 was set to be near the minimum in normalized conductivity for a 0.080 inch long crack. As the number of disks and slots inspected increases, the threshold levels can be determined with statistical methods based on the probability of detection for a given crack size. Representative threshold levels are A1=0.992 and A2=0.995
The minimum in the normalized conductivity for all of the slots on a disk are illustrated in
The use of MWM sensors and Grid measurement methods can also provide a more meaningful assessment of weld quality than conventional inspection methods. The high cost and complexity of titanium welding are caused by special cleaning and shielding procedures to preclude contamination. Quality control of titanium welds includes, among other things, inspection for contamination. Currently, titanium welds are accepted or rejected based on surface color inspection results, even though the surface color has not been a reliable indicator of weld contamination level.
The capability of the MWM to characterize contamination of the welds was demonstrated on several test specimens. Autogenous GTA welds were fabricated in six titanium Grade 2 plates with shielding gases that included high purity argon, three levels of air contamination, and two levels of CO contamination. The measurements were performed in a point-by-point "scanning" mode across each weld so that each scan included the titanium, Grade 2 base metal, heat-affected zones on each side of a weld, and weld metal. The footprint of the MWM sensor was § in. by § in.
Periodic field eddy-current sensors can also be used to detect overheat damage in gun barrels or other steel components that may be coated with another material or uncoated.
As an example, measurements were performed on two semi-cylindrical samples from a longitudinally sectioned 25-mm gun barrel. The section of this particular gun barrel, located between axial positions 8 in. and 24 in. away from the start of the rifling, had experienced overheating. Sample 2 a (in
These measurements indicate that the MWM probe response was characteristic of a ferromagnetic material. Note that the low-alloy steel is a ferromagnetic material whereas the electrodeposited chromium plating is nonmagnetic unless the plating had been exposed to high temperatures for sufficiently long time to effect diffusion of iron into the deposited plating. At a frequency of 100 kHz, the estimated depth of sensitivity in pure chromium is estimated to be approximately 0.5 mm, which is greater than the thickness of the electrodeposited chromium plating. As result, the MWM "sees" beyond the plated layer of chromium and the measurements reflect the effective permeability and microstructural conditions of the low-alloy steel. Thus, the unique bidirectional permeability measurement capabilities of the MWM provide sensitivity to the property changes caused by overheating. For rapid inspections of gun barrels, cylindrical probes having MWM sensors in both parallel and perpendicular orientations can be used so that a single measurement scans provides both measurements of the effective permeability.
Periodic field eddy-current sensors can also be used to detect and quantify the depth of subsurface cracks. As an example, consider the measurement illustrated in
While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
This present invention is related to:
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|Apparatus and methods for measuring permeability and conductivity in materials using multiple wavenumber magnetic interrogations
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|Apparatus and methods for obtaining increased sensitivity, selectivity and dynamic range in property measurement using magnetometers
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|Apparatus and method for holding a rotatable eddy-current magnetic probe, and for rotating the probe around a boundary
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|Clasificaciµn de EE.UU.
|324/238, 324/240, 324/209
|Clasificaciµn internacional
|Clasificaciµn cooperativa
|Clasificaciµn europea
|3 Abr 2007
|Certificate of correction
|26 Mar 2010
|Fee payment
Year of fee payment: 4
|10 Jun 2014
|Fee payment
Year of fee payment: 8


text:
No longer do homeowners have to try and make it through an entire weekend of defective plumbing simply to save themselves some money.
Calgary, AB (PRWEB) October 09, 2012
Most of the time a plumbing emergency is beyond the control of the homeowner. These aren't staged events, there is no way to plan for them and when they happen it can often be difficult to bring things back into order. That's why plumbing emergencies on the weekend are often a matter of chagrin: characteristically, plumbing companies charge extra to deploy their staff on the weekend.
This has been standard practice dating back to the beginning of the industry and the impetus behind it is easy to understand. No matter what industry a contractor or a qualified technician is in, the weekend is sacred and most people want to take it off if they can, plumbers being no exception to this rule.
All of this makes ERM Plumbing's recent announcement that weekend plumbing calls will now cost the same as weekday deployments a rather remarkable event. No longer do homeowners have to try and make it through an entire weekend of defective plumbing simply to save themselves some money. As long as they are in Calgary, they can contact ERM and have a fully certified tech at their location in a very short period of time.
This offering is even more notable given the fact that ERM never dispatches an apprentice plumber or a trainee, or at least never dispatches one of these individuals alone. This isn't a company that is cutting the end cost to their client by dropping the quality of the service. The service remains the same, the quality is still there.
Selecting a Calgary plumbing company is very often a matter of understanding which contractor is going to be providing a reliable service. Reliability is one of the hallmark characteristics to look for in the best plumbers, and it's a very difficult trait to pin down. There are certain plumbing outfits that may work great in some situations, but are a completely different service after regular business hours or on the weekend.
One of the reputations that ERM Plumbing & Heating has been able to acquire over the years is a reputation for consistency. Everytime they do a job they are able to get directly to the bottom of the problem, diagnose the situation quickly and efficiently and proceed with an effective solution. It's this efficiency that has led many to regard ERM as one of the top Calgary plumbers available, and their most recent price alteration is likely to pave the way for a new wave of satisfied customers.

subset: commoncrawl


text:
Grease fire at Hilbert College extinguished by sprinklers
A grease fire Sunday evening in an apartment building at Hilbert College drew firefighters from five Hamburg fire departments, but the building's sprinkler system extinguished the flames before their arrival, town police reported.
Firefighters from the Big Tree Volunteer Fire Company were dispatched at 6:56 p.m. to the school's Leo House, police said. Firefighters from Armor, Lake Shore, Scranton and Woodlawn Volunteer Fire Companies also responded, police said.
One occupant of the apartment was treated at the scene for minor burns. The 17 occupants of the building's four apartments were housed in a hotel Sunday night while water from the sprinklers was cleaned up, according to a school spokesman.


text:
Charity Skydive Fund Raising with Watford Womens Centre Plus
Take the Watford Women's Centre Plus challenge and experience the thrill of a lifetime.
FUEL Surcharge
Due to the current fuel price increases (aviation fuel), several drop zones are now making a surcharge of up to £30 per person, should this be the case at your selected location London Parachute School will contact you and advise you of this prior to processing your booking. If you choose to jump at a drop zone that has added a fuel surcharge then you will have to raise that extra amount in addition to the £350 minimum amount to jump, eg if the drop zone you choose has added a fuel surcharge of £15 then you will need to raise a minimum of £365


text:
A drink driver head-butted a police officer after he had been stopped for driving erratically in Portadown.
Thirty-two-year-old Thomas Mejeris, Armagh Road, Portadown, admitted driving with excess alcohol, disorderly behaviour, resisting a constable and assaulting a constable on February 1.
Craigavon Magistrates Court heard last Wednesday that at 1.45am a car was seen to be driven erratically on the Garvaghy Road. It was veering from side to side over the white line.
Police signalled it to stop and it stopped at the entrance to Garvaghy Park. There was a female passenger in the front seat and two small children in the rear of the vehicle.
The defendant, who was driving, smell strongly of intoxicating liquor, his nose was bloody and his speech was slurred.
He took a preliminary breath test which gave a reading of 127.
Mejeris struggled with police and had to be placed on the ground and handcuffed. He was lifted to his feet and led to the police vehicle. He swore loudly at police.
At the police vehicle he head-butted an officer who suffered a bump above his left eye.
An evidential breath test gave a reading of 95 - the legal limit is 35.
District Judge, Mr Mervyn Bates, said the defendant had been disqualified in April of last year for four months and in all the circumstances he would require a pre-sentence report.
Adjourning the case until April 16 he imposed an interim driving ban on the defendant.


text:
Four nights of rockin' music
It's a rockin' way to end the week.
Three nights of concerts featuring bands with very unique and different styles will be held at Penn's Peak in Jim Thorpe.
• Tonight, the Dublin band Thin Lizzy entertains at 8 p.m. Tickets are $27 and $32.
• Tomorrow night, some of the best rock music from the 80s will be on stage when Slaughter, headed by the talented Mark Slaughter, is on the stage at 8 p.m. Support acts are Taunted by Tomorrow and Wicked Sins. General admission tickets are $24.
• On Saturday, one of the original Southern rock bands, Molly Hatchet, will be doing all their big hits as well as songs from their newest LP. Opening will be Blackfoot. Tickets at the door are $27.
Thin Lizzy has an all-star lineup of veteran musicians. They include Alumni Scott Gorham, Brian Downey and Darren Wharton along with Viv Campbell (Def Leppard), Marco Mendoza (Whitesnake, Ted Nugent) and Ricky Warwick (The Almighty's).
Thin Lizzy exploded onto the music scene some 30 years ago.
Once lead by Phil Lynott, the band produced classic hits like "Jailbreak," "The Boys Are Back In Town," "Still In Love With You," "Cold Sweat" and "Emerald."
They reached their pinnacle of success in 1983 and a mere three years later, they lost their founding member, Lynott, who died of heart failure and pneumonia at the young age of 36.
Decades have past, but Thin Lizzy still retains their stellar sound and influence, just with a new and improved lineup.
Slaughter is an American heavy metal band formed in Las Vegas by lead vocalist/rhythm guitarist Mark Slaughter and bassist Dana Strum. Both Slaughter and Strum are presently with the band.
The band's biggest hit was "Fly to the Angels," although "Up All Night" and "Spend My Life" also charted.
Slaughter almost had a short lifespan when Mark Slaughter was diagnosed in 1992 with a nodule on his right vocal chord. Fortunately, surgery was a success and Mark was back performing in just a few months.
In 1993, the band faced more hardship when guitarist Tim Kelly was killed in a car accident.
A great friend of Tim's, Jeff Blando, replaced Tim in the group and was received with open arms by Slaughter's legion of fans. Blando remains with Slaughter today, as does long-time member Blas Elias.
Molly Hatchet has been at the Peak in the past and has always attracted large crowds.
"We love it at the venue," said Bobby Ingram, who is owner and guitarist for the band. "All of us were thrilled when we heard we were coming back."
He said the hospitality, the fans, and the acoustics are among the things that the members of Molly Hatchet enjoy at Penn's Peak.
One thing new with Molly Hatchet is the band's latest LP, "Justice." Among the songs on it is "Fly On Wings of Angels," dedicated to Somer Thompson, a 7-year-old Florida girl who was abducted on her way to school and then raped and murdered. Ingram has started the Somer Thompson Foundation and is devoted to bringing awareness to such crimes.
In two years, Molly Hatchet will celebrate their 35th anniversary of the first national or internationl release with their first double live album, "Locked and Loaded."
Blackfoot was originally called "Hammer." The band, renamed Blackfoot, initially had disbanded, but then reformed and remain united.
The band produced the Grammy nominated "Train, Train." Other hits include "Highway Song" and "Baby Blue."


text:
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Reiter Foothills Update - January 22, 2010
Reiter Workshop + 2 attached files
We had a great public workshop on January 13 in Monroe. More than 100 people attended to learn what kinds of volunteer opportunities are available at Reiter, to share their ideas about where to do restoration and where to locate trails, to sign up to be part of a work group, and to get trained to help with citizen patrols.
If you werent able to attend the meeting, you can still sign up to volunteer and/or share your ideas with us.
To offer your suggestions on restoration and/or trail development, please see the attached questions. A map is also attached which you may print and refer to if you like. Please send your response electronically to firstname.lastname@example.com, or mail a hard copy to David Way at 919 North Township, Sedro-Woolley WA 98284.
Training to participate in citizen patrols through our forest watch program is taking place in late January. The training course was very popular and the first session is completely full (60 people signed up). We will offer future training sessions and let you know when those opportunities become available.
Field Days Scheduled
Join us for a field day to learn about how things are progressing at Reiter with restoration and trail development and to share your ideas. Field trips are scheduled for February 6 (restoration), February 20 (motorized trail area), and February 27 (non-motorized trail area), beginning at 10:00 a.m. We will send participants more detail as to location, etc, closer to the field dates. Please contact us at firstname.lastname@example.com to sign up and let us know your contact information (phone and/or e-mail) and which date you would like to join us. The deadlines for signing up for the field days are a week prior to each field day - January 30th for the February 6th field day, February 13th for the 20th filed day, and February 20th for the 27th field day
Progress in the Field
Work continues in Reiter Foothills Forest. At a work party on January 17, more than 40 volunteers showed up, along with three donated tractors, four off-road rigs, and four small trucks to haul wood chips to stabilize stream areas. Volunteers helped with the following projects:
· Picked up garbage dumped on Forks of the Sky State Park.
· Began restoration efforts on three main stream crossings.
· Began restoration efforts at the northern end of Reiter Pond.
· Hauled wood chips to restoration project locations.
· Began restoration on several hundred feet of impacted trail surface.
It was a very successful work party. Folks are excited to get out and help restore impacted areas in hope of getting the Reiter Foothills open as soon as possible. The majority of the volunteers were members of Reiter Trail Watch and other 4x4 recreationists.
Thank you to everyone who showed up for the workshop and for the many on-the-ground work parties. We cant do it without you!
Candace Johnson
Assistant Region Manager, State Lands
Northwest Region
Department of Natural Resources
Past owner of a 2007 Jeep Wrangler named RubyDoo. :super:
PNW4WDA Reigon 1 member
Reiter Trail Watch Treasurer
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Short barrel .357s
View Single Post
September 9, 2012, 05:40 PM
Senior Member
Join Date: July 20, 2005
Location: Indiana
Posts: 10,170
Originally posted by Blue Train
To WebleyMkV, while what you say is correct in that a faster burning powder is more efficient in a shorter barrel, because it's more likely to all be burned within the barrel, I don't think that's necessarily the way to measure efficiency. It may or may not be true that the faster burning powder will produce a higher velocity, though it will probably produce less muzzle flash or blast. I would be more likely to believe that a heavier charge of slower burning powder may in fact produce a higher velocity even at the cost of less efficiency as far as burning powder is concerned. Even so, there's more to it than that.
The key to getting the highest possible velocity is maintaining peak pressure for as long as possible. Whether a fast burning powder or slow burning powder is best for the task depends on both bullet weight and barrel length. Generally, for light bullets and/or short barrels, faster burning powder is preferable. This is because pressure is at or peak when the bullet leaves the case and the powder is mostly, if not completely, burned by the time the bullet leaves the barrel. Slower burning powders are not preferable for short barrels or light bullets because the bullet will likely be well down if not out of the barrel and a good percentage of the powder will burn after the bullet has already left the barrel.
Conversely, slower powders are better for longer barrels and/or heavier bullets. This is because a larger percentage of the powder will burn before the bullet exits the case, thus ensuring that peak pressure is not reached too soon, and because the powder will continue to burn until the bullet is out, or almost out, of the barrel. Slower burning powders are less preferable for light bullets and short barrels because peak pressure is likely to be reached well before the bullet leaves the case, thus reducing the length of time it can be maintained while the bullet travels down the barrel, and because the powder will likely we burnt up well before the bullet exits the barrel thus reducing pressure quickly and allowing the friction of the barrel to slow the bullet's velocity.
If you have a variety of handguns, particularly of the same caliber, you may not want to customize the loads that much. In other words, there's no point in having the same caliber if you use different loads in different guns, though I still understand the object. One might want to use different loads even though you only had one gun. In addition to having a load suitable for shooting 1957 Chevrolets, which would be detestible, you might still have use for wadcutters in your pet .357 revolver.
Sticking to one loading for a given caliber is understandable enough as I do it myself. Both my 2 1/2" S&W M66 and my 4" M28 are loaded with Remington 158gr SJHP. This loading is among the most efficient in my snub and I do not feel that it is markedly inferior to lighter, faster .357 Magnum loadings even from a longer barrel. Of course, I've long thought that 158gr bullets were the best "all purpose" weight for a .357 Magnum.
Ultimately, you can only measure the efficiency of the load by measuring the velocity of the load--in your own gun. That's true for factory ammo, too, about which you may not know anything about the powder. Of course, muzzle flash and blast can still be a concern that you will still want to take into account no matter what the velocity comes out to be.
Yet another reason that I prefer the heavier 140-158gr bullets in a .357 Magnum is that, with full power loadings, the blast and flash does not seem nearly as pronounced though they're still not what I'd describe as "kind and gentle".
Smith, and Wesson, and Me. -H. Callahan
Well waddaya know, one buwwet weft! -E. Fudd
All bad precedents begin as justifiable measures. -J. Caesar
Last edited by Webleymkv; September 10, 2012 at
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Published: December 7, 2009
The birth of Kayden Jace Jenkins on April 15 made this year memorable for his parents, Jemel and Kelley Jenkins of Youngstown. He is the baby brother of Jemel Jr. and Amyah Jenkins.
Sign up for our newsletter to receive daily news directly in your inbox.


text:
- red
This orchid arrangement is designed and sized to be a centerpiece for your home. Our designer selected large cymbidium orchids, tropical flowers and dock leaves and arranged them in a woven pineapple basket to bring the tropics to your home. This the size of this piece demands a large room and table for its display.


text:
Don't miss your chance to see Midnight Red in Philadelphia! Check out the schedule below for the concert date of your choice, then buy your Midnight Red Philadelphia tickets before they sell out!
Looking for Midnight Red tickets in other cities? View all Midnight Red tickets »
Sorry! We couldn't find any events for Midnight Red in Philadelphia.
If you were searching to see if Midnight Red is coming to Philadelphia, then you're in luck! For their latest tour, Midnight Red will indeed hold a concert in Philadelphia. Have an awesome concert experience when you go to see Midnight Red in Philadelphia. Get your Midnight Red tickets Philadelphia and join fellow fans for a concert to remember!


text:
It's Time to Backup Your Digital Photos!
With the prevalence of Digital Photos, we end up with many more photographs than we had back in the film processing days. That adds up to a ton extra snapshots – to make sure you get that 'perfect' picture – comes a larger problem, a lot more photos taking up a lot more hard drive space.
Of course, the more photos you add to your computer, the more risk there is that you lose everything if you hard drive or your computer crashes. Not an ideal situation, to say that least.
It is the right time of year to think about how you care for your online photos. Having just entered into 2008, you need to think about how you are protecting yourself from that next hard drive crash.
The way I look at it, you have a couple of options.
1. Subscribe to an online service that allows you to upload your photos to them. Among many service out there: Google's Picasa, Yahoo's Flickr, and Shutterfly – all popular services. While Google (one of the few times) trails in this area, for $24.95/year allows unlimited uploads, storage, and a 10MB file limit. With a 10.1MP camera, the JPEG images produce end up in the 4-5MB range so that should be plenty. Picasa and Shutterfly may also reduce the size of your original image degrading the quality – although Shutterfly does allow unlimited picture storage today.
2. Your other option is to put in a process so that you protect yourself against the loss of such pictures.
I could write for the next 10 pages about the pros and cons of the two choices, but will attempt to sum it up in a couple of sentences.
For the online option the pros are someone else is worrying about storing your pictures, and you can get to them from anywhere you are at, often for a small feed. The cons are that you're at the mercy of the services if they change their terms, go out of business or have a major disaster – remember online photo storage has only been around for a short period of time – and you must have a high-speed upload connection – cable modems and DSL may not be quick enough for high quality pictures. Another big con is that if you shoot in RAW mode, even Flickr converts it to a JPG, so if retaining the original quality of the photo is important, this may not be an appropriate option.
For the do-it-yourself option, you have to commit to whatever processes you put in place to make sure you are consistent. The buck stops with you, but you can make it more fool and economy proof.
Thus far – I have chosen the do-it-yourself methodology although I have recently considered an upgrade to Flickr Pro at the $24.95 rate. For me, it is both a daily backup (automatic) and an annual archive process. The rest of this post will cover the process I have put in place.
First though, the situation:
For the year 2007 that just ended, I took over 11GB worth of photos from both our Canon PowerShot G7 and the Powershot SD800IS. As I repeat the process, the size of the pictures I took in 2007 was nearly triple the size of the photos in 2006, and 2006 was triple the size of 2005. See a progression -- does this mean 40GB for 2008?
The process I have put in place consists of the following...
First, I have an extra hard drive in my computer that is just for backup purposes. Every night at 10:00PM I have a backup job using a basic ROBOCOPY backup job to copy all my pictures and other important things to the backup drive. That insures if my primary hard drive goes bad, then I still have all the valuable data and pictures backed up!
Secondly, at the beginning of every year – and today is that day – I create and Archive folder on my hard drive and move all of the photos from the previous year into that folder. Once I create that location, I spend a couple of hours removing pictures I do not want to keep and then prepare to move them to media. From there, I create the appropriate number of DVDs via my DVD burner with Roxio Creator DE – this year it was 3 DVDs. Then I take those DVDs, put them in my fire safe and consider that to be relatively safe. In the next couple of years I plan to instead move the DVDs to a safety deposit box at a secure location like a bank.
Just set an annual reminder in Outlook to make sure you do not forget. And with that, in the case of most disasters – all of our photos are protected in multiple ways.
Have you backed up your pictures recently? If not, now is a great time to start!


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Home Legend 1/2 in. Cork is a naturally "Earth Minded" flooring. Along with the floorings aesthetic beauty, the cork construction provides a natural thermal insulator retaining ambient temperatures in your home. This product has achieved Greenguard Indoor Air Quality Certification and has been tested for more than 10,000 volatile organic compounds, including formaldehyde, to meet these standards. The glueless installation is easy and economical; above grade, on grade and below grade. The flooring is resilient to indentions and is an excellent sound and vibration inhibitor.
California residents: see Proposition 65 information
- Wood Species: Corkwood (Leitneria floridana)
- Each sample is 5 inches in width and 7 inches in length.
- Prefinished Cork Natural Herringbone, Medium Color, Smooth Finish
- Construction: High Density Fiberboard (HDF) Cork Flooring
- Hardwood samples are not returnable


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HOUSTON, March 12 (UPI) -- An attorney for a homeless man ticketed for rummaging through a Houston trash can for food said the law supporting the citation is "crazy."
James Kelly, 44, said he was looking through a trash bin Thursday near Houston City Hall when an officer issued him a citation for "disturbing the contents of a garbage can in [the] downtown business district," the Houston Chronicle reported Tuesday.
"I was just basically looking for something to eat," Kelly said. "I wasn't in a real good mood."
Randall Kallinen, the attorney representing Kelly, said the citation was the result of the city's moves last year to regulate feeding the homeless.
"Now, when they try to feed themselves anyway possible, they make that a crime as well," the lawyer said.
"It's crazy to have a law where you can't look through things that are being discarded," Kallinen said. "People are always looking for cans and so forth -- that's part of recycling."
The police department issued a statement in response to questions about the citation.
"The ordinance is specific to the Central Business District. It is a violation for anyone to remove any contents of any bin, bag or other container that has been placed for collection of garbage, trash or recyclable materials. An officer has probable cause to issue such a citation when a person is seen opening a lid and rummaging through contents of a dumpster or trash can," the statement said.


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Here at Review Centre we work hard to make sure we are the best place on the internet for honest, unbiased consumer reviews - we are grateful for your help in keeping us that way!
Written on: 15/05/2013
Cool price with an awesome support, i like zyma.com.
As far as I am concerned there isn't any provider that can hold a candle to Zyma - Rock on Zyma staff!


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Artist/provateur Banksy has published a handful (actually, two hands' full) of images of his work for download at his website, including versions of each in 1600x1144 or larger resolution.
Serving suggestion:
Prints look best when done on gloss paper using the company printer ink when everyone else is at lunch.
His stuff just cracks me up.


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Former SKYCLAD and current RETURN TO THE SABBAT frontman Martin Walkyier has issued the following statement in response to the news that British all-girl rock band/sex commune ROCKBITCH have decided to cease all gigging activities:"It was with deep regret that I received an email this morning informing me that one of our planet's most unique and enlightened bands had decided to call an end to live-performances. Since first hearing their music, I recognized instantly that ROCKBITCH were among the rare few truly sincere artistes in the music scene today. It will be a tragic occurrence indeed should we never again witness these special ladies transforming a mundane concert hall into a vibrant temple of spiritual and sexual awakening for the evening. It's such a shameful reflection upon our present times, when a band of this extraordinary calibre cannot get the recognition they so rightfully deserve. "I fully appreciate the struggle they've endured, and understand their reasons for feeling as if they can stand this frustration no longer having also experienced prejudice and misunderstanding myself throughout course of my creative career. The general public are largely terrified by the truth, and therefore brand as fools and freaks all who actually speak it. I think it makes them feel safer and more comfortable that way. It is hard work indeed to wake a world which doesn't even realize it's sound asleep. Two thousand years of pious Christianity really has quite a lot to answer for, and when slow-witted humanity finally discovers the true meaning of life, then all shall live and love like ROCKBITCH, I am certain! "Do not lose hope or be faint of heart, for I feel the God and Goddess walking constantly at our sides. For all those who experience life to the limit, each dawn is a fresh adventure, every ending just the start of a brand-new beginning. There will one day come a time when the entire human-race learns that it's far better to fuck than fight with each other, it's just a shame that it will probably take some global nuclear or biological holocaust to teach our species this most basic lesson in life. I hear the distant pulsing of an ancient sexual energy rousing deep inside the belly of Mother Earth, as a giant serpent's heartbeat slowly stirring from its primordial slumber. As a raging whirlwind once awoken, it will sweep away the stagnation and hypocrisy of all that has gone before as part of the endless cosmic cycle of renewal. The cultural rebirth of our civilization, bringing about a drastic and long-overdue reappraisal of the moral, spiritual and economic foundations of human society. I sense a rapidly-approaching age when free-thinkers and lovers may yet have their say, and the 'freak' shall inherit The Earth! May your guardian-spirits be with you always."
MARTIN WALKYIER: ROCKBITCH Were One Of Planet's Most Unique And Enlightened Bands
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Father: Charles Milton ADAMS b: 10 JUL 1826 in Madison County, Ohio
Mother: Selina Jane EWING b: 30 MAY 1832 in Union Co., Ohio
Marriage 1 Sarah Adella WOODWORTH b: 6 MAR 1859
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By Jimmy LaRoue
Midlothian, Va. – VSA Heat 96G coach Gus Donolo said he has never seen a better goalkeeper at defending penalties than Zoe Foxhall.
With her team's Virginia Under-15 Girls State Cup final against PWSI Courage 96 Red tied 3-3 after regulation and overtime on Sunday, Foxhall's skill paid off. She made two saves, on Courage's first and last attempts, and with Heat converting on all four of their attempts, those stops secured the title with a 4-3 shootout win.
VSA Heat 96G have now qualified for the 2012 Region I U.S. Youth Soccer Region I Championships in Hershey, Penn. next June.
"I have had a lot of 'keepers that I've gone through since I started coaching 12 years ago," Donolo said. "And she just has a magnet to the ball against the players that take the PK. She always goes to the correct side. Half of it is guessing, but she also is trained very well to look at the girls' hips when they shoot and how they position their body…She always looks them in the eye."
Kelli Burney, Kristin Schnurr, Becca Callison and Sarah Strachan converted Heat's penalties. It's the second State Cup title for Heat 96G, who led 2-0 with just a few minutes left in regulation. However, Skylar Dowell scored twice for Courage to force overtime.
The Heat scored first early in overtime before Courage rallied once more in the latter stages, scoring on a penalty-kick conversion from Sara Deutsch to force penalties.
Donolo said the players were well prepared despite being forced to penalties in Saturday's semifinal win over FASA Elite Impact. The team stayed in nearby Richmond overnight, ate well Saturday night, then woke up early for breakfast, had an hour of tactical meetings and then spent another 40 minutes watching video and talking more tactics before taking the field.
"We really treat this team like a professional team," Donolo said.
With their place in the Region I tournament secure, the Heat are able to focus on tactics rather than trying to play their way into the field.
"Although every team plays to win, now we can play a little more relaxed knowing that we're already going to regionals," Donolo said.


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Whose China?
Whether the exhibition of contemporary art from China currently showing at the Israel Museum is a faithful reflection of the country's art scene or a case of giving the West what it wants, it is worth a visit. Where else can you see a Han Dynasty vase being smashed to smithereens?
"Made in China" is an exhibition whose time has come. Chinese art has long been a hot topic in the international art world: It is a star in art dealing (although its staggering prices are seen as an economic bubble), and Chinese artists show in all the leading international galleries. In the past five years art fairs in China (including Hong Kong) have become de rigueur stops on the annual calendars of art dealers, no less than important art events in the West. In China's big cities, especially Beijing, Shanghai and Hangzhou, new public as well as private art institutions are going up quickly, creating a sense of vitality and excitement. For all these reasons, an exhibition in Israel that showcases the work of contemporary Chinese artists is significant.
The main question that arises from a visit to this exhibit is "What are we seeing?" Is this truly a cross-section of contemporary Chinese art, or only what the West wants to see? The exhibition at the Israel Museum was first shown at the Louisiana Museum of Modern Art in Denmark. This is not an exhibition that was curated in China. Rather, it originated as the Estella Collection from New York, gathered from the world's major collections of contemporary Chinese art. The perspective on Chinese art created in the exhibition, therefore, has been through several filters: the tastes of the collectors, the works that are offered to American collectors, and of course, the sections of the Danish museum and, subsequently, Suzanne Landau, the curator of this exhibition for the Israel Museum.
Mao suits and Chinese opera
Most of the works displayed here are what can be termed "biennale art"; not only because many of them were shown at the biennales of Venice and Istanbul that has been held since 1999 (the year in which Harold Szeemann, then-curator of the Venice Biennale, began to place special emphasis on Chinese art), but mainly because this is spectacular art: Most of the works are very large and present decisive figures that can be taken in at the first glance. Chinese elements can be found in many of them, from Mao suits to allusions to Chinese opera. And so, one wonders once again whether these images are derived from forces in the world of Chinese imagery or whether the Chinese artists successful in the West are the ones who "deliver the goods," allowing the West to see what it wants while basking in a sense of superiority.
In view of the uneven quality of the works presented, the exhibition seems to have given clear preference to quantity over quality. It could have been tightened up, dispensing with certain works, such as the photographs and paintings of Wei Dong (born 1968), which deal with pornographic images and seem to be a Western fantasy about China.
One of the show's better-known pieces is "Bloodlines: The Big Family," a 1995 painting by Zhang Xiaogang (born 1958), which is 226 cm. wide. The painting was executed in oil on canvas, the traditional Western technique preferred by the Chinese government since the beginning of the Communist revolution and the adoption of the Russian Socialist realism style. The subject, a one-child family, the only family model permitted in China, is presented by Xiaogang as a tragic portrait of expressionless faces, identical for the father, mother and child, whose gender is unclear. The figures are differentiated by their clothing: The parents wear gray Mao suits, the child a Red Guards uniform. They are looking forward, but their gaze is not hopeful, as with the Socialist Realist paintings; it is lifeless.
Scrutiny of the past appears repeatedly in the works. Among the most successful of this type are the photographs by Hai Bo (1965), which are outstanding in their delicacy and their relatively modest dimensions. In "Bridge," from 2000, Hai created a diptych of what appears to be an old black-and-white photograph of a bridge, on which two men and a woman are standing; the man's face is turned toward one of the women and he is leaning on a railing. In the second photo, taken at the same place, in color, the man is looking in the same direction, but he is alone, as if unsuccessfully looking for the past. In "Four Seasons," the artist photographed a figure in the same position at the same site in the different seasons. Although this has been done many times before, the quality of Hai's work is outstanding.
Shao Yinong and Mu Chen also deal in memory, in their series "The Assembly Halls." It is a work of cataloging and mapping reminiscent of the photographic activities of the German couple Bernd and Hilla Becher in the 1970s (which had great impact on Israeli photography). The photographs show halls where local political rallies took place during the Cultural Revolution. Some have been converted for other uses, such as religious rituals, while others stand abandoned. While the "Chineseness" of Hai's work does not come to the fore in a major way, in Shao and Mu's photographs the eye sees only through knowledge of the historical context.
As in Hai's works, Xing Danwen's "Sleepwalking" video installation does not need to be "Chinese" to justify its inclusion. It features huge cities, the location of which and sometimes even the perspective from which they were filmed is not clear. Rather, they are presented one after the other against a soundtrack of urban noises and instrumental music, which seems familiar and strange at the same time. A glass box with metalwork affixed to both ends floats in space. According to the gallery notes, these elements are in the style of the Ming Dynasty (1368-1644). Small video images of what looks like tamed nature appear inside the box. Xing Danwen creates the option of escapism within and above reality, and speaks of the not entirely tangible touches of the past in the present.
Cigarette burn calligraphy
Traditional Chinese painting and calligraphy are expressed in many works, through the format of inked and printed scrolls, from Feng Lijun's dramatic "Swimmer" (1963), consisting of six scrolls with a total width of almost 8 meters and a height of 488 cm., to "Digital Series" by Wang Tiande (1960), delicate ink works burned with cigarettes. The works seem like classical landscape paintings, somewhat misty, until one comes closer and realizes that they were created with cigarette burns.
Works documenting calligraphy and bodypainting have come to be identified with contemporary Chinese art. Some have been shown in Israel before, such as those of Zhang Huan, which appeared about a year ago in an exhibition in Tel Aviv. Zhang, one of the most important artists exhibiting in China in the 1990s, who moved to the U.S. in 1998, asked three calligraphers to write on his face (which recalls Israeli Anisa Ashkar's ongoing work), until his face was entirely painted and in fact obliterated. One of the works is Zhang's "My New York," commissioned by the Whitney Museum of American Art, in New York. Zhang designed a bodybuilder's "meat suit" for himself, made of slices of meat, which very much recalls Canadian artist Jana Sterbak's 1987 meat dress. Zhang walked the streets of New York in his outfit, releasing doves into the air. The work expressed criticism of U.S. aggression, perhaps the only work in the exhibit in which the artist's perspective is not only wondering about the West or criticizing Chinese history, but expressing direct criticism of the West.
References to the transition from the cult of Communism to extreme capitalism appear a number of times in the exhibit. The most prominent work on this subject is "People and Cockroaches (Employed Farmer)" from 1998, by Liang Juhui (1959-2006). It is a photograph showing grinding poverty surrounded by images of cockroaches on the walls. Other prominent works are the photograph "Opera" by Miao Xiaochun (1964), a six-meter-wide photo taken in a zoo; a painting by Qiu Shihua (1940), which seems empty at first until a landscape is revealed; and an installation by Ai Weiwei, "Dropping a Han Dynasty Urn" (1957), in which a Han Dynasty vase is dropped, smashing into fragments. This destruction of a work of art from the past alludes to the erasing of the past, as was done during the Cultural Revolution, but also to the present, in which China's past is disappearing in the modernization washing over it.
Made in China: Contemporary Art from the Estella Collection
Curator: Suzanne Landau. The Israel Museum, Jerusalem. Sunday, Monday, Wednesday, Saturday and holidays, 10 A.M.-5 P.M.; Tuesday 4-9 P.M.; Friday and holiday eves 10 A.M.-2 P.M. Until February 2008.
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The Brooklyn buzz has been palpable. The Nets make their official debut in the borough next week at the uber-new Barclays Center on Atlantic Avenue. But before the Nets tip off the season, there is word that they'll have co-tenants. The New York Islanders are headed for Brooklyn starting with the 2015-16 season, The New York Times reports.
The deal between Islanders owner Charles Wang and Barclays owner Bruce Ratner was expected to take place this afternoon.
FishbowlNY was unable to confirm the story, but YES Network's Ian Eagle, the longtime Nets announcer, knew the handwriting was on the Nassau Coliseum wall.
"I'm not surprised," Eagle tells FishbowlNY. "That was not going the way that Charles Wang had hoped for."
Wang had been desperately seeking repairs to the rundown Coliseum in Uniondale, where the Islanders have been since joining the NHL in 1972, or a brand new home on Long Island.
"I think this became the next best option and a chance to latch on to some of the buzz," Eagle says.
Last August, Nassau County voters gave an emphatic no to spend $400 million to upgrade the arena, making Wang's move inevitable, if not completely ideal.
"It's going to be a smaller arena for hockey," Eagle says. "The building was built with basketball in mind."
But Eagle says a few run-throughs were done for Wang and Islanders GM Garth Snow, showing "Barclays on Ice."
"They still are priding themselves on being a multi-purpose arena," Eagle says. "You just look at the amount of events that they've already put in there. They're not resting on their laurels."


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Hi I am using Windows 8.1 Preview. Build Number 9431. And with Internet Explorer 11 version 11.0.9431.228. Updated Version: Preview (KB2898785). I always get a constant IE 11 crashes. Currently I am using F-Secure 2014 Internet Security Preview.
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The BYU Cougars have had an impressive basketball program for a long time. They have had great teams, legendary coaches and great players. The Cougars have even had 10 players win Conference Player of the Year Awards, six First-Team All-Americans and seven Second-Team All-Americans, according to BYUCougars.com. Great success at the college level doesn't always translate to success at the pro level, however.
Although BYU has had 42 players drafted in either the ABA or the NBA, only 21 of them have ever played a regular season game.
This list is the ranking of those 21 players who have played in the NBA (or ABA) out of the Y.
Note: these rankings are based solely on what each player did while playing in the NBA, ABA or in one case, the BAA. What a player did in college was not taken into consideration.
All stats come from Basketball-Reference.com.
See all 21 BYU players who have played in the NBA
Jay Yeomans is a courier by day and a freelance writer by night. He is the creator and lead writer of the website jmoneysports.com. Contact him at email@example.com. Twitter: @jmoneysports


text: From the Sony VX of Ryan Alvarado comes a new video out of San Diego with the Sk858 OGs: Brian Gille, Jimmy Cao, Jamie Palmore, Brandon Lefever, John Lupfer, Spencer Prati, and more. This crew loves downtown San Diego, day or night. Disturbing The Peace premiering this Saturday night, November 3 at Downtown Johnny Browns. All ages!


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Closing Bell: Meeting Tonight About Gowanus Sludge
Tonight the EPA will host a meeting for Red Hook residents concerned about the EPA's proposal to construct a facility in Red Hook that decontaminates the material dredged from the Gowanus Canal Superfund site and uses it as landfill. You can read lots of details about the proposal over at the Red Hook Star Revue. The proposed "contaminated disposal facility" would go in the Gowanus Bay Terminal. There the Gowanus soil would be coalesced into a solid mixture of sand, dredge and cement to create a landfill. According to the Revue, "the plan creates developable land for the GBX's owner, John Quadrozzi, Jr. The land's use would ultimately be the decision of Quadrozzi alone." Quadrozzi first proposed this in the fall, and at that point the EPA's involvement was uncertain. The plan is now in its public comment period, which lasts until April 27th. The public meeting on the matter will be held tonight at 6:30 pm in PS 15 on Sullivan Street (between Van Brunt & Richards).
EPA Seeks Input on Placement of Gowanus Sludge [Red Hook Star Revue]
Developer Wants Gowanus Sludge to Create Landfill [Brownstoner]
Photo by Jim in Times Square


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Production problems with the iPhone 6 could see the release of one of its models delayed to next year, according to analysts.
Apple is expected to release both 4.7-inch and 5.5-inch versions of its new iPhone in the fall. But according to rumours, a bottleneck in production of the 4.7-inch model could push the release of the 5.5-inch model into 2015.