An artificial light source generator includes at least one luminescent set and a projection plane. The luminescent set includes a light source, a parabolic mirror, a supporting seat, a first lens array, and a second lens array. The light source is disposed at the focus of the parabolic mirror, so that light beams generated by the light source are transmitted in a parallel direction through the parabolic mirror. The supporting seat is for supporting the light source. The first lens array has a plurality of first lens units, and each of the first lens units has a first focal distance. The second lens array has a plurality of second lens units. The distance between the second lens array and the first lens array is 0.5 to 1.5 times the first focal distance. A suitable distance exists between the projection plane and the luminescent set, so that the light beams passing through each of the second lens units cover the entire projection plane. Therefore, the projection plane has excellent illumination uniformity.

1. Field of the Invention
The present invention relates to an artificial light source generator, and more particularly to an artificial light source generator capable of simulating natural light in a large area.
2. Description of the Related Art
As public awareness about environmental protection and energy conservation is on the rise, many efforts are being made to developed solar cell modules. However, one of the major challenges for development of solar cell module is testing after manufacturing. The intensity of natural light (sunlight) changes at different points of a day and is difficult to control artificially, so solar cell modules are generally not placed outdoors for testing. In conventional testing, an artificial light source is used indoors to simulate sunlight, so as to obtain relevant product characteristics of the solar cell modules.
Two conventional testing methods are described below. In the first method, a flash xenon lamp is used with a flash time of about tens of milliseconds each time, which covers a flash area of more than 1*1 square meter, and can meet the uniformity requirements by means of the profile design of lighting fixtures and lamps. The disadvantage of this method is that the flash time is too short, so it is difficult to obtain correct or sufficient voltage and current data. Further, light soaking or hot spot tests that require light irradiation for a long time cannot be performed in this testing method.
FIG. 1 shows a schematic view of a projection plane in the second conventional testing method. A plurality of sets of continuum lamps (for example, 6 sets) is used for irradiation, so as to form six illumination regions 11 on a projection plane 10. The lamps may be tungsten lamps, metal-composite lamps, xenon lamps, or other light sources capable of emitting lights stably and achieving a required spectrum after being filtered by a filter mirror. The lamps are arranged adjacent to one another in a specific manner so that the illumination uniformity of the projection plane 10 meets certain requirements. If necessary, a shading material (for example, wire net) is applied between the lamps and the projection plane 10, so as to reduce the light on a certain region to meet the illumination uniformity required for the whole projection plane 10.
The disadvantage of this method is that the position and intensity of each lamp and the density of the wire net must be adjusted to achieve the required uniformity, which is rather difficult and labor-consuming. Generally, it takes about ten days to make one adjustment. Whenever the attenuation of a certain lamp differs from that of the other lamps, the adjustment must be made again. For example, if the lamp on the top left corner of the illumination region 11 is attenuated too fast, the illumination region 11 will be darker than the other illumination regions, and a readjustment will be needed. In addition, if the overall uniformity deteriorates due to the shift of a certain component, a readjustment will also be needed.
Therefore, it is necessary to provide an artificial light source generator to solve the above problems.


Described is a process for determining excitants, attractants, incitants and stimulants for members of the Class Crustacea including but not limited to Penaeus setiferus, Penaeus aztecus, Penaeus vannamei and Procambrus clarkii. The apparatus for carrying out the process includes static tank flow-through tank and Y-maze each equipped with variable-focus camera. Also described is a method for exciting and/or attracting and/or stimulating and/or inciting members of the Class Crustacea including but not limited to Penaeus setiferus, Penaeus aztecus and Penaeus vannamei (referred to collectively as Penaeus spp.), as well as Procambrus clarkii, using various dilute aqueous solutions of molecules including but not limited to N-acetyl-D-Glucosamine which is an epimeric mixture of isomers having the structures: ##STR1## as well as feeding compositions of mixtures for feeding members of the Class Crustacea including (i) prior art feeding compositions and admixed therewith (ii) Crustacea Class-exciting and/or attracting and/or stimulating and/or inciting amounts and concentrations of excitants, attractants, stimulants and/or incitants which include molecules including but not limited to the compounds having the structures: ##STR2##

Our invention is drawn to a process for determining excitants, stimulants, attractants and incitants for members of the Class Crustacea and a method for exciting, inciting, stimulating and/or attracting members of the Class Crustacea by means of placing within a body of saline water near a surface or throughout the volume to which such Crustacea are desired to be attracted, stimulated, incited and/or excited, a Crustacea attracting, stimulating, inciting and/or exciting concentration and quantity of at least one of the substances:
(i) N-acetyl-D-Glucosamine, an epimeric mixture of compounds having the structures: ##STR3## (ii) S-methyl methionine sulfonium halides defined according to the structure: ##STR4## (wherein X is chloro or bromo); (iii) methionine having the structure: ##STR5## (iv) trimethyl amine oxide hydrate having the structure: ##STR6## (v) 1-octen-3-ol having the structure: ##STR7## (a mixture of isomers having the structures: ##STR8## (vi) methional having the structure: ##STR9## (vii) dimethyl sulfoxide having the structure: ##STR10## (viii) 50:50 mole:mole mixture of skatole/indole, skatole having the structure: ##STR11## indole having the structure: ##STR12## (ix) propionthetin halides having the structure: ##STR13## wherein X is chloro or bromo; (x) ammonium chloride; PA1 (xi) ammonium acetate; PA1 (xii) acetic acid having the structure: ##STR14## (xiii) glucose; (xiv) "raw sugar" (sucrose and "impurities"); PA1 (xv) Thaumatin (known as TALIN.RTM. a trademark of the Tate and Lyle Company Limited of the United Kingdom), a mixture Thaumatin B, Thaumatin I and Thaumatin II, the liquid/the liquid chromatograms of which are indicated in FIGS. 23 and 24 attached hereto and described, infra. Thaumatin I is shown also by the symbol: EQU Lys.sup.46, Asp.sup.113, Asp.sup.137 ! PA1 as further specifically described in U.S. Pat. No. 5,221,624 issued on Jun. 22, 1993 the specification of which is incorporated herein by reference; PA1 (xvi) 2-methyl-3-(methyldithio)furan having the structure: ##STR15## (xvii) aqueous ammonia; (xviii) yeast extract; PA1 (xix) D-Glucosamine, an epimeric mixture of compounds having the structures: ##STR16## (xx) 2-methyl-3-furanthiol (also known as "OXYCYCLOTHIONE-030.TM.", a trademark of International Flavors & Fragrances Inc.) having the structure: ##STR17## (also hereinafter referred to as "ASIE" substance(s)) as well as feeding compositions containing (i) one or more of such "ASIE" substances admixed with (ii) prior art feeding compositions. PA1 (i) N-acetyl-D-Glucosamine, an epimeric mixture of compounds having the structures: ##STR19## (ii) at least one S-methyl methionine sulfonium halide having the structure: ##STR20## (wherein X is a chloride anion or a bromide anion); (iii) methionine having the structure: ##STR21## (iv) trimethyl amine oxide hydrate having the structure: ##STR22## (v) (R)(S) 1-octen-3-ol having the structure: ##STR23## (a mixture of isomers having the structures: ##STR24## (vi) methional having the structure: ##STR25## (vii) dimethyl sulfoxide having the structure: ##STR26## (viii) 50:50 mole:mole mixture of skatole/indole, skatole having the structure: ##STR27## indole having the structure: ##STR28## (ix) propionthetin halides having the structure: ##STR29## wherein X is a chloride anion or a bromide anion; (x) ammonium chloride; PA1 (xi) ammonium acetate; PA1 (xii) acetic acid having the structure: ##STR30## (xiii) glucose; (xiv) raw sugar (sucrose and "impurities") for example, Osceola Brown Sugar marketed by Osceola Farms Inc. of Pahokee, Fla. (the headspace analysis for which is set forth in FIG. 27 described in detail, infra); PA1 (xv) Thaumatin (known as TALIN.RTM. a trademark of the Tate and Lyle Company Limited of the United Kingdom), a mixture Thaumatin B, Thaumatin I and Thaumatin II, the liquid/the liquid chromatograms of which are indicated in FIGS. 23 and 24 attached hereto and described, infra. Thaumatin I is shown also by the symbol: EQU Lys.sup.46, Asp.sup.113, Asp.sup.137 ! PA1 as further specifically described in U.S. Pat. No. 5,221,624 issued on Jun. 22, 1993 the specification of which is incorporated herein by reference; PA1 (xvi) 2-methyl-3-(methyldithio)furan (also called "MOS" or "METHYLOXYCYCLOSULFIDE.TM.", a trademark of International Flavors & Fragrances Inc.) having the structure: ##STR31## (xvii) aqueous ammonia; (xviii) yeast extract; PA1 (xix) D-Glucosamine, an epimeric mixture of compounds having the structures: ##STR32## (xx) 2-methyl-3-furanthiol (also known as "OXYCYCLOTHIONE-030.TM.", a trademark of International Flavors & Fragrances Inc.) having the structure: ##STR33## taken alone, or in combination with naturally occurring excitants, stimulants, attractants and/or incitants for the Class Crustacea such as natural Crustacean/cephalopod extracts to the vicinity of said desired location or volume. Our invention also describes a process for exciting, attracting, stimulating and/or inciting a member of the Class Crustacea within a volume of water inhabited by such member of the Class Crustacea comprising the step of applying an aqueous solution containing a Crustacean-exciting, attracting, inciting and/or stimulating concentration of one of the above materials (designated as "ASIE" materials) to the vicinity of said volume inhabited by said member of the Class Crustacea. PA1 (a) static holding tank means containing (i) a volume of water and (ii) at least one live member of the Class Crustacea within said volume of saline water; PA1 (b) pump-injected test solution feeding means for pumping aqueous solutions at variable or constant flow rates of test substance into the static holding tank means; PA1 (c) visible light generating and guidance means for guiding visible wavelength light of variable or preferably constant intensity into said volume of water in said static holding tank means; PA1 (d) first variable power source means for engaging the visible light generating means; PA1 (e) second variable power source means for engaging the pump generated feeding means; and PA1 (f) variable focus/focal length video camera or camcorder recording means for recording the movements of one or more specified body appendages and/or the lateral direction and velocity of one or more specified body appendages of one or more of the members of the Class Crustacea when the pump injected feeding means and visible light generating means are engaged; PA1 (a) flow-through holding tank means where varying concentrations of test solutions are fed in at the inlet of the holding tank means and flow through the holding tank to an exit portal while a member of the Class Crustacea is positioned within the "flow-through" holding tank. The holding tank contains (i) flowing saline water and (ii) at least one live member of the Class Crustacea within the flowing saline water; PA1 (b) pump-injected test solution feeding means for pumping aqueous solutions at variable or preferably constant flow rates of test solution into an orifice in front of the entry portal into the flow-through holding tank; PA1 (c) visible light generating and guidance means for guiding visible wavelength light of variable or preferably constant intensity into the volume of water flowing in the flow-through holding tank; PA1 (d) a first variable power source for energizing or "engaging" the visible light generating means; PA1 (e) a valuable power source for energizing or "engaging" the pump injection feeding means (the pump has variable heads so that the flow rate of the added chemical solution (containing at least one "ASIE") may be added to the basic flow of saline water through the flow-through holding tank); PA1 (f) variable focal length video camera or camcorder recording means for recording the movements and/or the lateral direction and velocity of one or more members of the Class Crustacea when the pump injection feeding means is engaged and when the visible light generating means is engaged; and PA1 (g) specially designed camera platform and blind means (a part of our invention) the purpose of which is to shield the observer from the test animal in order to prevent the test animal from being extraneously stressed and/or distracted. (The variable focal length video camera or camcorder recording means is mounted within the specially designed camera platform and blind means.) PA1 (1) a horizontal static substantially rectangular planar base located in an "X-Y" plane, having an upper surface and having two substantially parallel ends parallel to the "X" axis and two substantially parallel ends parallel to the "Y" axis; with one end parallel to the "Y" axis being along a line designated "E.sub.1 "; PA1 (2) a vertically disposed substantially rectangular planar frame located in a "Y-Z" plane, substantially perpendicular to said horizontal static planar base and having two parallel ends parallel to the "Y" axis and two parallel ends parallel to the "Z" axis, one of said ends parallel to the "Y" axis being contiguous with said static planar base along a first end, said line E.sub.1 of said static planar base, parallel to the "Y" axis, said frame having a first orifice therethrough permitting visible wavelength radiation to be transmitted therethrough; PA1 (3) a continuous right angle-shaped horizontal/vertical planar base/frame movable platform movable in both the "X" and "Y" (or lateral) directions consisting of (i) a substantially rectangular horizontal lamina located in the "X-Y" plane facing and within the planar framework of said horizontal static planar base (1) plane and having an upper surface and a lower surface continuously and sealably juxtaposed in a direction parallel to line E.sub.1 along a line designated E.sub.2 said line E.sub.2 being proximate said line E.sub.1 with (ii) a substantially rectangular vertical lamina located in the "Y-Z" plane facing and within the planar framework of said vertically disposed frame (2) and containing a vertically disposed visible wavelength radiation shield (blind) having a second orifice therethrough located opposite to and being planarly parallel to and within the planar framework of said first orifice in said vertically disposed frame, said right angle-shaped movable platform being located on rollers juxtaposed with and immediately adjacent said lower surface of said right angle-shaped movable platform and said upper surface of said horizontal static base; PA1 (4) a substantially rectangular rotating planar base having an upper surface and a lower surface and having two parallel ends parallel to the "Y" axis and two parallel ends parallel to the "X-Z" plane, being rotatable about a vertex line E.sub.3 in a hinge manner having a direction parallel to each of lines E.sub.1 and E.sub.2 and being substantially proximate lines E.sub.1 and E.sub.2 along a first parallel hinge end in the "Y" direction parallel to the "Y" axis, having variable manually-controllable rotation movement means located at an end of said rotating planar base opposite said first parallel hinge end, and opposite the location of said line E.sub.3, the direction of rotation of said rotating base being from the location of the "X-Y" plane of said right angle-shaped movable platform towards the location of the "Y-Z" plane of said right angle-shaped movable platform about the said vertex line E.sub.3 ; and PA1 (5) a video camera or camcorder fixedly mounted on the upper surface of said rotating planar base, comprising a housing and a lens located in said housing, the focal plane of said lens being substantially parallel to and at a controllably variable distance from the plane of said first orifice of said vertically disposed frame and said second orifice of said visible wavelength radiation shield with said lens, said first orifice and said second orifice all having a common line of vision, PA1 (i) Taurine, the compound having the structure: ##STR36## (ii) Guanidine, the compound having the structure: ##STR37## (iii) Betaine, the compound having the structure: ##STR38## (iv) citric acid, the compound having the structure: ##STR39## (v) Pyruvic acid, the compound having the structure: ##STR40## (vi) Ferulic acid, the compound having the structure: ##STR41## (vii) Vanillin, the compound having the structure: ##STR42## (viii) Isovaleraldehyde, the compound having the structure: ##STR43## (ix) trans-2-hexenal, the compound having the structure: ##STR44## (x) Citral, the mixture of compounds having the structures: ##STR45## PA1 I. The following "alginate" mixture is prepared in the following manner: PA1 II. Feed Mixing Protocol: PA1 A=Antennule flicking; PA1 AN.sub.2 =Antennae movement; PA1 M=Maxilliped movement; PA1 MP=Mouthpart movement; and PA1 D=Dactyl movement (in the characteristic "feeding" motion).
Aquatic animals utilize water-borne "chemical signals" (chemical stimuli) to identify and orient toward potential food sources, to escape predators and locate mates. These specific chemical signals are recognized in spite of the chemical complexity of aquatic environments. Therefore, the chemical environment of aquatic animals is vitally important, both physiologically and behaviorally, to understand the status and role of animals in the aquatic environment. The function of specific chemical signals becomes even more significant in a managed biological system (i.e., aquaculture ponds or tanks) that is optimized for production of a single aquatic species (e.g., members of the Penaeus genus of the Class Crustacea) since these chemical signals regulate feeding behavior and possibly control reproduction. Because feeds are a significant expense in most aquaculture operations, the need to maximize feeding rates and reduce wasted feed, thereby lowering production costs and the possible lowering of bacterial/viral infections is paramount to economic success.
The importance of chemoattractants and/or feeding stimulants in improving both initial palatability and overall feeding rates as a means to reduce wasted feed is now fully recognized. The feed quality and environmental conditions (i.e., water quality and current patterns) have direct effects on the effectiveness of feed attractants and feed stimulants. For these reasons, food detection and feeding stimulation ultimately determine the commercial value of an aquatic feed.
A number of attempts at obtention of efficacious feeding stimulants for various aquatic species and for creation of appropriate testing apparatus having a high degree of efficiency for determining good stimulants and attractants for aquatic species are set forth in the literature. Thus, U.S. Pat. No. 4,250,835 issued Feb. 17, 1981 and U.S. Pat. No. 4,249,480 issued Feb. 10, 1981 disclose apparatus and methods for rearing shrimp through the larvae stage wherein the shrimp are subjected to controlled conditions and a common enclosure for the male and female adult shrimp is provided which permits uncontrolled access of the shrimp to one another and wherein the shrimp are maintained through a plurality of cycles of mating, spawning and hatching. The system disclosed provides filtration means for filtering the medium of the common enclosure and with collecting means for harvesting hatched shrimp at preselected times from the common enclosure medium as the medium moves into the filtration means. U.S. Pat. No. 4,828,829 of May 9, 1989 discloses a visual fish attractant that aids in the dispersion of traditional scent and taste attractants. The fish attractant compositions include one or more oils, such as mineral oil, cod liver oil, menhaden oil, herring oil, anise oil, salmon oil, as well as pigments, fragrances, fish scent, dispersed pigments, and light-reflective particles that act both as a visual attractant and as an aid to controlled dispersion of the oil and scent compositions.
Lombardo, et al, Comp.Biochem.Physiol., Vol. 101C, No. 2, pages 389-398, 1992, "Amino Acids and Derivatives as Food-Finding Signals in the Freshwater Snail Planorbarius corneus (L.)" discloses the behavioral responses of the freshwater snail to various amino acids including l-aspartic acid, d-alanine, histamine, proline and aspartame.
It should be pointed out, however, that the compounds having the structures: ##STR18## wherein X is a "univalent anion" such as chloride ion or bromide ion are used to attract in a gel vertebrate fish such as red snapper and carp in Japanese Published Application J91/27231 (Nakajima) abstracted at Chem. Abstracts, Volume 115:113303n. The disclosure of Japanese Published Application 91/27231 does not detract from the patentability of the instant invention.
Nothing in the prior art, however, discloses the efficient process for attracting, inciting, stimulating and/or exciting members of the Class Crustacea from or in a volume of water inhabited by said member(s) of the Class Crustacea in or to a desired location or volume within a body of water by applying at least one of the specific materials found to be useful in our invention, to wit the "ASIE" substances found to be so useful in our invention. Furthermore, nothing in the prior art discloses feeding compositions containing such "ASIE" substances admixed with prior art feeding materials for such members of the Class Crustacea.

Feeding compositions including excitants, attractants, stimulants and incitant

Board of Regents, University of Texas System


The invention relates to methods for potentiating, enhancing or restoring glucose responsivity in pancreatic islets or cells. The methods can be used as therapies for diseases caused by, or coincident with, aberrant glucose metabolism, such as Type II Diabetes Mellitus.

Diabetes is one of the most prevalent chronic diseases in the United States, and a leading cause of death, afflicting over 400 million diabetics in the world today. Estimates based on the 1993 National Health Interview Survey (NHIS) indicate that diabetes has been diagnosed in 1% of the U.S. population age <45 years, 6.2% of those age 45-64 years, and 10.4% of those age >65 years. As of 1995, an estimated 8 million persons in the United States were reported to have this chronic condition.
The total cost of diabetes in the United States has been estimated at $92 billion annually, including expenditures on medical products, hospitalization and the value of lost work. Substantial costs to both society and its citizens are incurred not only for direct costs of medical care for diabetes, but also for indirect costs, including lost productivity resulting from diabetes-related morbidity and premature mortality. Persons with diabetes are at risk for major complications, including diabetic ketoacidosis, end-stage renal disease, diabetic retinopathy and amputation. There are also a host of less directly related conditions, such as hypertension, heart disease, peripheral vascular disease and infections, for which persons with diabetes are at substantially increased risk.
Diabetes mellitus is a heterogeneous group of metabolic diseases which lead to chronic elevation of glucose in the blood (hyperglycemia). Diabetes is characterized by pancreatic islet destruction or dysfunction leading to loss of glucose regulation. The two major types of diabetes mellitus are Type I, also known as "insulin-dependent diabetes" ("IDDM") or "juvenile-onset diabetes", and Type II, also known as "non-insulin dependent" ("NIDDM") or "maturity-onset diabetes".
IDDM results from an autoimmune-mediated destruction of pancreatic β cells with consequent loss of insulin production, which results in hyperglycemia. Type I diabetics require insulin replacement therapy to ensure survival. While medications such as injectable insulin and oral hypoglycemics allow diabetics to live longer, diabetes remains the third major killer, after heart disease and cancer. However, these medications do not control blood sugar levels well enough to prevent swinging between high and low blood sugar levels, with resulting damage to the kidneys, eyes, and blood vessels. Data from the Diabetes Control and Complications Trial (DCCT) show that intensive control of blood glucose significantly delays complications of diabetes, such as retinopathy, nephropathy, and neuropathy, compared with conventional therapy consisting of one or two insulin injections per day. Intensive therapy in the DCCT included multiple injection of insulin three or more times per day or continuous subcutaneous insulin infusion (CSII) by external pump. Insulin pumps are one of a variety of alternative approaches to subcutaneous multiple daily injections (MDI) for approximating physiological replacement of insulin.
Type II diabetes is characterized by hyperglycemia in the presence of higher-than-normal levels of plasma insulin (hyperinsulinemia) and represents over 90% of all cases and occurs most often in overweight adults over 40 years of age. Progression of Type II diabetes is associated with increasing concentrations of blood glucose, coupled with a relative decrease in the rate of glucose-induced insulin secretion. In Type II diabetes, tissue processes which control carbohydrate metabolism are believed to have decreased sensitivity to insulin and therefore occurs not from a lack of insulin production, but a decreased sensitivity to increased glucose levels in the blood and an inability to respond by producing insulin. Alternatively, diabetes may result from various defects in the molecular machinery that mediate the action of insulin on its target cells, such as a lack of insulin receptors on their cell surfaces. Treatment of Type II diabetes therefore frequently does not require administration of insulin but may be based on diet and lifestyle changes, augmented by therapy with oral hypoglycemic agents such as, for example, sulfonylurea.
The endocrine portion of the pancreas is composed of the islets of Langerhans, which appear as rounded clusters of islet cells embedded within the exocrine pancreas. Four kinds of islet cells compose the endocrine portion of the pancreas: (1) alpha (α) cells, constituting 20% of islet cells, which secret glucagon, a hormone which raises blood sugar levels; (2) beta (β) cells, which secrete insulin, a hormone which lowers blood sugar levels; (3) delta (δ) cells, which secrete growth hormone inhibiting hormone (GHIH) or somatostatin, a hormone which inhibits the secretion of insulin and glucagon; and (4) φ cells, or pancreatic polypeptide (PP) cells, which synthesize pancreatic polypeptide. Glucagon acts on several tissues to make energy available in the intervals between eating. In the liver, glucagon causes breakdown of glycogen and promotes gluconeogenesis from amino acid precursors. Pancreatic polypeptide inhibits pancreatic exocrine secretion of bicarbonate and enzymes, causes relaxation of the gallbladder, and decreases bile secretion. Insulin is known to cause the storage of excess nutrients arising during and shortly after eating. The major target organs for insulin are the liver, muscle and fat-organs specialized for storage of energy.
The most abundant cell in the islets, constituting 60-80% of the cells, is the insulin-producing β cell. The β cells of the human fetal pancreas are different from adult pancreatic β cells in that they release little or no insulin in response to glucose. (See, e.g., Tuch, B. E. et al. (1992) J. Endocrin. 132:159-67). This has been observed in both humans and rodents, and resembles the delayed insulin response to glucose observed in patients with Type II diabetes or malignant insulinoma. (Hellerström and Swenne (1991) Diabetes 40(2):89-93; Tuch et al., supra). The inability of fetal β cells to produce insulin in response to glucose is not believed to be due to an inability to process insulin precursors. Adult human β cells synthesize preproinsulin and convert this into proinsulin (hPI) in the endoplasmic reticulum. Thereafter, hPI is split into insulin and C-peptide via a regulated pathway in the secretory granules. The rate of conversion of hPI in the adult β cell is high, resulting in a low hPI:insulin ratio both as regards to content and secretion (Gold, et al. (1981) Diabetes 30:77-82). This is also observed for fetal β cells, suggesting that β cell immaturity is not due to differences in the storage and release of proinsulin. (Tuch et al., supra). The acute release of both hPI and insulin from the fetal β cell in response to an increase in Ca2+ and cAMP suggests that the cell releases its secretory products via a regulated, rather than a constitutive pathway. (Rhodes and Halban (1987) J. Cell Biol. 105:145-53).
The lack of glucose responsiveness in fetal β cells is thought to be due to immature glucose metabolism. The molecular mechanism underlying glucose-induced insulin secretion in adult β cells involves the closure of ATP-sensitive K+ (KATP) channels in the plasma membrane, thereby inhibiting K+ efflux through K+ATP channels, leading to depolarization of the cell membrane. (Jones, P. M. and Persaud, S. J. (1998) Endocrine Reviews 19(4):429-61; Mendonca et al., supra; Cook, D. L. and Hales C. N. (1984) Nature (London) 311:271-73). Consequently, cytosolic Ca2+ concentration increases as a result of the membrane depolarization and Ca2+ influx through L-type (voltage-sensitive) Ca2+ channels. Glucose raises the intracellular concentration of cAMP and of regulators derived from membrane phospholipids, including inositol triphosphate (IP3), diacylglycerols (DAG), arachidonic acid (AA) and phosphatidic acid. (See Jones and Persaud, supra). It has been suggested that reduced insulin secretion in response to glucose reflects the uncoupling between glucose metabolism and membrane cell depolarization. (Mendonca et al., supra). Studies indicate that the ATP-sensitive K+ channel, although fully developed, is not properly regulated in the fetal β cell and that the deficient secretory response to glucose may reflect an immature mitochondrial glucose metabolism resulting in an inability to close the otherwise normal ATP-sensitive K+ channel. (Hellerström and Swenne, supra.).
Pancreatic development occurs in discrete stages and is regulated by endocrine hormones produced by pancreatic cells themselves or by other tissues. In the rat, the pancreatic anlage forms at embryonic ("e") day 10.5 ("e10.5") by fusion of the dorsal and ventral pancreatic primordial buds that arise as protrusions from the duodenal endoderm. (Pictet, R. and Rutter, W. J. (1972) "Development of the Embryonic Endocrine Pancreas." In D. Steiner and N. Freinkel (eds.) Handbook of Physiology, The Endocrine Pancreas, Vol. 1, Section 8, Am. Physiol. Soc., pp. 25-66; Myrsén-Axcrona, U. et al. (1997) Regulatory Peptides 68:165-75). Islet hormones appear sequentially in the developing pancreas: for example, glucagon appears at e10 in mouse and e11 in rat, insulin producing cells appear in e12, somatostatin producing cells appear at e17. (See Myrsén-Axcrona et al., supra). It is thought that pancreatic islet cells differentiate in response to endocrine signals from a common precursor cell in the pancreatic ducts. Sometime between the end of the rat fetal stage (e21) and neonatal stages (post-birth) the fetal β cells acquire the ability to secrete insulin in response to glucose. The insulin response at this age is monophasic and is not blocked by Ca2+ antagonists. A clear biphasic pattern of insulin secretion in response to glucose is detected only 3 days after birth. (Mendonca, A. C. et al. (1998) Brazilian J. Med. Biol. Res. 31(6):841-46). The mechanism by which this "gain of function" or "gain of glucose responsivity" is achieved is not known, nor have the factors that regulate the maturation and gain of function been identified or characterized. In addition, the physiological changes associated with gain of glucose responsivity in pancreatic β cells are not known.
The instant invention is based on the discovery that a factor, "peptide yY" or "PYY", triggers gain of function in glucose non-responsive fetal and adult islets which leads to glucose responsivity, and therefore provides therapies for diseases affecting glucose metabolism such as Type II diabetes.

Methods and reagents for treating glucose metabolic disorders


Fluoropolymer is advantageously foamed by first forming a composite structure of a layer of the fluoropolymer to be foamed and a layer of different material such as a different fluoropolymer not to be foamed, followed by heating the composite structure to the foamable state for the layer of fluoropolymer to be foamed, pressurizing the heated composite structure with supercritical carbon dioxide, rapidly depressurizing the heated composite structure, whereby the foamable layer foams and the other layer foams less or not at all, and cooling the foamed composite structure.

Composite wire insulation has been made by coextruding melt-fabricable fluoropolymer coating onto wire, which coating is foamed as it leaves the extruder, and a solid fluoropolymer skin onto the foaming coating, such as disclosed in U.S. Pat. Nos. 4,711,811 and 4,716,073. The presence of the foaming during the extrusion and the coming together of the coextruded fluoropolymers makes it difficult to control the thicknesses of the two layers forming the wire insulation, which is especially important as the thickness of these two layers is decreased to provide smaller diameter insulated wire. In addition, the adhesion between the layers (foam and skin) suffers from the foaming action occurring as the adhesion between the layers is forming.
Foamed tubing, i.e. tubing with a foamed sidewall, is desirable for forming more flexible and/or lightweight tubing, but it is very difficult to make foamed tubing because there is no center wire to support the tubing during solidification from the molten extrudate. Moreover, the foaming of the molten extrudate reduces melt strength, furthering the tendency of the tubing to sag and deform, especially as the wall thickness and/or diameter of the tubing increases.
There is a need for the ability to form foamed fluoropolymer structures which do not have the foregoing problems.

Method of forming foamed fluoropolymer composites


Embodiments of the invention may generally provide a small volume electrochemical plating cell. The plating cell generally includes a fluid basin configured to contain a plating solution therein, the fluid basin having a substantially horizontal weir. The cell further includes an anode positioned in a lower portion of the fluid basin, the anode having a plurality of parallel channels formed therethrough, and a base member configured to receive the anode, the base member having a plurality of groves formed into an anode receiving surface, each of the plurality of grooves terminating into an annular drain channel. A membrane support assembly configured to position a membrane immediately above the anode in a substantially planar orientation with respect to the anode surface is provided, the membrane support assembly having a plurality of channels and bores formed therein.

1. Field of the Invention
Embodiments of the present invention generally relate to a low volume electrochemical processing cell and methods for electrochemically depositing a conductive material on a substrate.
2. Description of the Related Art
Metallization of sub-quarter micron sized features is a foundational technology for present and future generations of integrated circuit manufacturing processes. More particularly, in devices such as ultra large scale integration-type devices, i.e., devices having integrated circuits with more than a million logic gates, the multilevel interconnects that lie at the heart of these devices are generally formed by filling high aspect ratio, i.e., greater than about 4:1, interconnect features with a conductive material, such as copper or aluminum. Conventionally, deposition techniques such as chemical vapor deposition (CVD) and physical vapor deposition (PVD) have been used to fill these interconnect features. However, as the interconnect sizes decrease and aspect ratios increase, void-free interconnect feature fill via conventional metallization techniques becomes increasingly difficult. Therefore, plating techniques, i.e., electrochemical plating (ECP) and electroless plating, have emerged as promising processes for void free filling of sub-quarter micron sized high aspect ratio interconnect features in integrated circuit manufacturing processes.
In an ECP process, for example, sub-quarter micron sized high aspect ratio features formed into the surface of a substrate (or a layer deposited thereon) may be efficiently filled with a conductive material, such as copper. ECP plating processes are generally two stage processes, wherein a seed layer is first formed over the surface features of the substrate, and then the surface features of the substrate are exposed to an electrolyte solution, while an electrical bias is applied between the seed layer and a copper anode positioned within the electrolyte solution. The electrolyte solution generally contains ions to be plated onto the surface of the substrate, and therefore, the application of the electrical bias causes these ions to be urged out of the electrolyte solution and to be plated onto the biased seed layer.
Conventional chemical plating cells generally utilize a horizontally positioned plating cell and a pivot-type substrate immersion process. However, pivotal immersion processes are known to generate bubbles on the substrate surface as a result of the varying immersion angle generated by the pivotal immersion apparatuses. These bubbles are known to cause plating uniformity problems, and therefore, minimization of bubbles is desirable. Further, during the pivotal immersion process of conventional plating cells the substrate surface is not parallel to the anode of the plating cell, and therefore, the electric field across the surface of the substrate is not constant, which also causes uniformity problems.
Therefore, there is a need for an improved electrochemical plating cell configured to provide for an immersion process that includes maintaining the substrate at a constant immersion angle during both the immersion and plating processes.


A method for manufacturing a semiconductor device includes calculating a correction amount for correcting a dimension error generated in a pattern, by using an area and a total length of sides of a perimeter of the pattern included in each grid region of a plurality of mesh-like grid regions made by virtually dividing a pattern creation region of an exposure mask, exposing the pattern whose dimension has been corrected by the correction amount onto a substrate on which a resist film is coated, developing the resist film after the exposing, and processing the substrate by using a resist pattern after the developing.

1. Field of the Invention
The present invention relates to a method for manufacturing semiconductor devices, and a method for forming a pattern onto an exposure mask. For example, the present invention relates to a method of correcting a dimension error generated in transferring and printing a pattern of a mask to a wafer or in a subsequent wafer process, by adjusting dimensions of the pattern on the mask at each position when forming the pattern for manufacturing a semiconductor device. Particularly, the dimension error herein is based on an assumption that an error occurs when a certain figure or a figure group affects the dimension of a figure at a distant position.
2. Description of the Related Art
First, in manufacturing an LSI, an exposure mask is produced using a mask writing apparatus, etc. Next, a pattern on the exposure mask is exposed onto the resist on a silicon wafer (Si wafer) by using an optical scanner or a stepper. Then, through various steps, such as resist development and etching, a pattern of one layer is formed. An LSI is manufactured by repeating such a pattern manufacturing step some tens of times. These days an electron beam exposure apparatus is mainly used for writing or "drawing" a mask, but there are cases of using light beams. As to an apparatus for exposing a pattern of a mask, a light beam, whose wavelength is approximately 193 nm, is currently used as mentioned above. Moreover, a technique of utilizing an extreme ultraviolet light (EUV), an electron beam, or and an X-ray, whose wavelength is approximately 10 nm, has also been studied.
Regarding forming a pattern for one layer of the LSI, it goes through various steps as stated above. One of the problems of the LSI pattern formed through such various steps is that although each pattern is approximately uniform at the time of completion when seen from a local point (that is, locally, the difference with respect to the design dimension is almost uniform), the pattern dimension changes gradually when seen from the point of the whole of reticle or the whole of the inner side of a chip formed on a wafer (that is, the difference with respect to the design dimension changes gradually in the chip).
FIG. 34 shows an example of a state of a pattern dimension variation when seen from the point of the whole of the chip inside. An error shown in FIG. 34 will be called a global CD (critical dimension) error. Some examples are described below.
As the first example, there is a phenomenon called a flare generated when transferring and printing a pattern of a mask onto an Si wafer by using an optical stepper. This phenomenon is a pattern dimension variation generated by diffused reflection due to surface coarseness of a mask and/or a lens, and if there is a position where the pattern density is high, dimensions of other figures existing within several mm from the position concerned are changed by several nm to several tens of nm approximately. The phenomenon is generated not only in an optical transfer apparatus or a scanner, which is currently mainly used and utilizing an ArF (argon fluoride) excimer laser (wavelength of 193 nm) but also in an exposure apparatus (EUV stepper), which is expected to be used in the future and utilizing a wavelength of the EUV (Extreme Ultra Violet) region.
As the second example, there is a phenomenon called a loading effect generated at the time of dry etching performed for the Si wafer in the semiconductor manufacturing process. The dry etching is a step of, after forming a resist pattern by exposing and developing a resist film, etching a film in the underlying layer of the resist pattern serving as a mask, by using plasma. In this manufacturing step, the amount of a by-product created by the etching changes depending on the area of an exposed underlying layer (namely, pattern density). That is, an etching speed varies depending upon the amount of the by-product, thereby changing an etched dimension, which is the phenomenon of the loading effect. Consequently, the change of dimension depends upon the density of the pattern. For this reason, under the influence of a position where the pattern density is high, dimensions of figures existing in a region within several cm from the position are changed by several nm to several tens of nm.
In addition to the above stated cause, the loading effect also occurs due to a CMP (Chemical Mechanical Polishing) step or development of the resist, thereby changing dimensions of a pattern depending upon the density thereof.
As mentioned above, there are many phenomena by which dimensions of figures existing in a region within several mm to several cm from a position where the pattern density is high are changed by several nm to several tens of nm by under the influence of the density. For increasing the integration degree of a semiconductor integrated circuit, it is necessary to further enhance the formation accuracy in addition not only to miniaturize the figure. However, the phenomenon above mentioned hinders to raise the accuracy, which is an obstacle in advancing the high integration. The method of correcting the dimension change resulting from such a flare or a loading effect will be called global CD correction or GCD correction. The following can be cited as examples of the method of correcting the global CD. There is a method of correcting a figure dimension at each position to correct a dimension change produced in a semiconductor manufacturing step (refer to, e.g., Japanese Unexamined Patent Publication No. 2003-43661 (JP-A-2003-43661)). In this reference document (JP-A-2003-43661), a method is proposed that when calculating a correction amount, the LSI pattern is virtually divided into a plurality of mesh-like grids to use the density of a pattern inside the grid.
However, since this method is only an approximated correction as described below, it becomes difficult to further improve the high precision. This will be hereinafter described. First, formulation of a global CD error is explained. Then, the conventional method and its problem will be explained.
Now, with reference to the reference document (JP-A-2003-43661), the formulation of a global CD error will be described. An LSI pattern is divided into regions (mesh) each of which is sufficiently smaller than the distance of the influence range of a global CD error. The size of each mesh is defined to be ΔL×ΔL. When the center coordinate of the i-th mesh is defined to be xi=(xi, yi), an amount δl(xi), which is a dimension amount of a figure existing in the i-th mesh increased by a global CD error, can be expressed by the following equation (1). In this specification, it will be hereafter described as the coordinates xi=(xi, yi) or as the coordinates x=(x, y).
                              δ                                                                          l                                      (                              x                i                            )                                      =                                            γ              d                                                                  ∑                j                                                                            g                                                        (                                                                  x                        i                                            -                                              x                        j                        ′                                                              )                                                                                ρ                    0                                                                          (                                          x                      j                      ′                                        )                                                                                Δ                  L                  2                                                              +                                    γ              p                                                  f                                            (                                  x                  i                                )                                                                        (        1        )
Alternatively, regarding the size of the mesh to be sufficiently small, if expressed by an integral expression, it can be the following equation (2).
                              δ                                                                          l                                      (              x              )                                      =                                            γ              d                                                                  ∫                A                                                                            g                                                        (                                          x                      -                                              x                        ′                                                              )                                                                                ρ                    0                                                                          (                                          x                      ′                                        )                                                                                ⅆ                                      x                    ′                                                                                +                                    γ              p                                                  f                                            (                                  x                  i                                )                                                                        (        2        )
In the equations (1) and (2), the first term expresses a dimension change depending on the density of a pattern. In the loading effect generated in etching a wafer, this term corresponds to a dimension change depending on the density. The second term expresses a dimension change depending on only a position. In etching a wafer, this term corresponds to a dimension change generated due to unevenness of plasma used for the etching. In the equations (1) and (2), a pattern area density of the i-th mesh in the design is defined to be ρ0(xi)=ρ0(xi, yi). Influence of density of a certain position on other position is expressed as g(x)=g(x, y), and represented by standardized functions as shown in the following equations (3) and (4).
                                          ∑            j                                          ∑                          g                                            (                                                                            x                      i                                        -                                          x                      j                                                        ,                                                            y                      i                                        -                                          y                      j                                                                      )                                                    =        1                            (        3        )                                                      ∫            A                                                        g                                            (                x                )                                                                ⅆ              x                                      =                                            ∫                              -                ∞                            ∞                                                                  ∫                                  -                  ∞                                ∞                                                                            g                                                        (                                          x                      ,                      y                                        )                                                                                ⅆ                  x                                                                  ⅆ                  y                                                              =          1                                    (        4        )
The global CD error depending upon the density can be expressed by a coefficient γd. Since g(x) is standardized as mentioned above, γ indicates a difference between dimensions in the cases of the pattern density being 1 and 0. The value of γ varies depending upon a process concerned. For example, in the loading effect generated in dry etching, the value of γ varies from 5 to 20 nm. That is, depending upon a pattern density, the dimension changes from 5 up to 20 nm at the maximum.
A distribution function g(x)=g(x, y) of the loading effect can be expressed by the following equation (5-1) or equation (5-2), for example. Alternatively, other suitable functions can be utilized by the apparatus used for etching etc.g(x)=(1/πσL2)exp[−(x−x′)2/σL2]  (5-1)g(x)=(γ1/πσL12)exp[−(x−x′)2/σL12]+(γ2/πσL22)exp[−(x−x′)2/σL22]  (5-2)
where γ1+γ2=1. Alternatively, to be more general, the following equations (6-1) and (6-2) are used.
                              g                                (            x            )                          =                              ∑            k                                                        (                                                γ                  k                                /                                  πσ                  Lk                  2                                            )                                                  exp                                            [                                                      -                                                                  (                                                  x                          -                                                      x                            ′                                                                          )                                            2                                                        /                                      σ                    Lk                    2                                                  ]                                                                        (                  6                                -                              1                )                                1        =                              ∑            k                                          γ            k                                              (                  6                                -                              2                )
σL, σL1, σL2, . . . herein are the indications (influence range) of the distance of the range of the global CD error, and they are approximately from several 100 μm to several cm, for example. It is supposed that the size of a mesh is sufficiently smaller than the distance of the influence range of a global CD error as mentioned above, and it may be σL/10, for example. In the cases of σL being 1 mm and 1 cm, the sizes of meshes may be set to be 0.1 mm and 1 mm respectively.
Moreover, in the equations (1) and (2), a CD error depending on the position within a mask surface is defined to be γp×f(x, y). f(x, y) is defined to be a standardized function, whose maximum value is 1. By performing such definition, γp is equivalent to a maximum error of the global CD error depending on only a position. Moreover, Σ is calculated by summing in each small region.
Next, the conventional method will be explained. According to the conventional one, for example the method described in the Patent Document 1, a dimension of a figure at a position (xi, yi) is reduced by L0(xi, yi) in the following equation (7).
                                          L            0                                          (                          x              i                        )                          =                                            γ              d                                                                  ∑                j                                                                            g                                                        (                                                                  x                        i                                            -                                              x                        j                        ′                                                              )                                                                                ρ                    0                                                                          (                                          x                      j                      ′                                        )                                                                                Δ                  L                  2                                                              +                                    γ              p                                                  f                                            (                                  x                  i                                )                                                                        (        7        )
where ρ0(xi)=ρ0(xi, yi) is a density of the original pattern. In the conventional method, it is very simple because the dimension increased by the global CD error, that is L0(xi, yi) obtained from the equation (7), is subtracted from the dimension of the original figure. Therefore, it is not so accurate because of the following reason. That is, when calculating a dimension correction amount from the density of the original pattern and changing the dimension of the pattern by the calculated amount, since the dimension changes after being corrected, the density of the pattern corrected differs from the original pattern density. On the other hand, if it is supposed that the original pattern density is not changed and is kept, since the dimension is changed by L0(xi, yi) by using a process apparatus or a lithography apparatus for the pattern, it becomes as designed. However, as mentioned above, since the pattern density after correcting differs from that of the original pattern, the dimension after correcting cannot be the one as designed. That is, the exact dimension correction amount cannot be obtained by the above equation (7) for correcting, thereby becoming difficult to achieve an accurate global CD correction.
In addition, although it is not for correcting a global CD error, some documents are disclosed in which a solution is calculated for an equation for correcting the proximity effect generated by irradiation of an electron beam (refer to, e.g., Japanese Patent No. 3469422 and the U.S. Pat. No. 5,863,682).

Method for manufacturing semiconductor devices, and method for forming a pattern onto an exposure mask


A magneto-optical disk which reproduces information with an optical pickup head which uses an electromagnetic force as the driving force is provided. Other areas than at least the recording track are magnetized uniformly in a direction of canceling the influence of external magnetic field applied by the optical pickup head or a recording pattern having a frequency higher than modulation transfer function (MTF) of the optical pickup head is recorded to the other areas than at least the recording track. Read signals SP12 and SP14 from the magneto-optical disk are low in bit error rate.

Conventionally, the magneto-optical disk is known as a rewritable disk-shaped recording medium. Recently, various techniques have been developed for improving the recording density of the magneto-optical disk. One such technique has recently been disclosed in the Japanese Unexamined Application Publication No. 290496 of 1994, for example.
The playback technique disclosed in the above Japanese Unexamined Application Publication is a magnetic domain wall displacement detection type ultra-high resolution magneto-optical playback technique, called "DWDD (domain wall displacement detection)", used on a magneto-optical disk having at least three magnetic layers: displacement layer, switching layer and memory layer and which exploits the fact that the magnetic domain recorded in the memory layer will substantially be extended in the displacement layer. DWDD is to detect a magnetic domain wall displaced in an area in the displacement layer that corresponds to an area where a magnetic coupling between the memory and displacement layers corresponding to an area in the switching layer, irradiated with a read laser light for reading information signal and having reached a temperature higher than the Curie temperature, is broken, whereby a magnetic domain recorded in the memory layer is substantially extended in size in the displacement layer to increase read carrier signal.
The DWDD-based magneto-optical playback method (will be referred to as "DWDD playback method" hereunder) will be described in detail herebelow. In FIG. 1A, a magneto-optical disk to which the DWDD playback method is applied is generally indicated with a reference 100. As shown, the magneto-optical disk 100 is constructed of three magnetic layers including a displacement layer 101, switching layer 102 and memory layer 103. In the magneto-optical disk 100, the memory layer 103 is magnetized in different directions of arrows M1 and M2 as shown in FIG. 1A because of forward and reverse spins to record data as long as a magnetic domain. In this magneto-optical disk 100, a boundary between two successive magnetic domains 104 magnetized in different directions is a domain wall 105. It should be noted that an arrow R in FIG. 1A indicates the rotating direction of the magneto-optical disk 100.
When a read laser light BM is incident upon the magneto-optical disk 100, a temperature is distributed there as shown in FIG. 1B since the laser light BM provides a local heating. It should be noted that a reference Ts indicates a Curie temperature of the switching layer 102 and an area Dp in the switching layer 102 where the temperature is higher than the Curie temperature Ts will be demagnetized. In the magneto-optical disk 100, the demagnetization in the switching layer 102 will lead to disappearance of the force of switched connection between the demagnetized area Dp in the switching layer 102 and the memory layer 103. Thus in the magneto-optical disk 100, the domain wall having a lower coercivity as an area in the displacement layer 101 that corresponds to the area Dp is singly displaced toward a higher-temperature side indicated with an arrow S in FIG. 1A. Such a displacement of the domain wall will take place each time the domain wall existing in the displacement layer 101 correspondingly to each recorded mark in the memory layer 103 reaches an isothermal curve of the temperature Ts as the magneto-optical disk 100 is scanned. With detection of such a domain wall displacement, data recorded in the memory layer 103 of the magneto-optical disk 100 is substantially extended and read. It should be noted that the domain wall is displaced to near a spot where the temperature is highest, for example, the rear of a beam spot.
The DWDD playback method is one of the important playback methods permitting to read a very large signal from a very small recording domain, as well, of which the period is smaller than the critical optical resolution of a read laser light, with a high density without having to change the wavelength of the read laser light, numerical aperture (NA) of objective lens, etc. Say, the DWDD playback method allows to considerably improve the recording density in the scanning direction of laser beam spot.
On the other hand, the recording methods includes mainly two types: optical modulation and magnetic field modulation. The magnetic field modulation permits to record a mark in smaller size and increase the volume of data to be recorded correspondingly.
In the magnetic field modulation type recording, a recording laser light whose output level is higher than at the time of disk playback is projected onto the magneto-optical disk 100, a modulation magnetic field corresponding to a signal to be recorded is applied to the magneto-optical disk 100 to write the signal to be recorded, as a mark, to a desired recording track. FIG. 2 shows the relation in shape between a beam spot SP defined by a write laser light on a recording track 100a and the mark 110 recorded to the memory layer 103 of the magneto-optical disk 100.
In the field modulation type recording, with the write laser light being projected onto the magneto-optical disk 1A, record is sequentially made by a modulated field to a hot spot 111 taking place nearly in the center of the beam spot SP correspondingly to the shape of the beam spot SP, with the result that the mark 110 will be recorded there, as shown in FIG. 22. Where the hot spot 111 takes place depends upon the shape of the beam spot SP. So, when the beam spot SP is generally circular as shown in FIG. 2, the recorded mark 110 will be shaped to copy the rear end of the hot spot 111. Namely, the mark 110 thus recorded will have a fletching-like shape. More specifically, the shape of an edge portion 110a, defining the profile, of the recorded mark 110 depends upon the curvature of the rear end of the beam spot SP. It should be noted that the temperature of the hot spot 111 will exceed a temperature higher than the Curie temperature in the memory layer 103 and it is different from a temperature of a hot spot taking place due to irradiation of a read laser light at the time of disk playback.
In the DWDD playback method, the mark 110 recorded by the field modulation type recording is reproduced by detecting a displacement of the edge portion 110a developed by heating with a projected read laser light. Thus, the DWDD playback method can improve the linear density of the magneto-optical disk.
In the production of the above-mentioned magneto-optical disk, a recording layer to which information is recorded, a protective layer for the recording layer, etc. are formed on a substrate. The layers just formed are magnetized in different directions, which will cause noises when information is written to or read from the disk. Once information is recorded to the disk, the noises to the recording track on the magneto-optical disk disappear. However, since recording is made only the recording track, so the disk will remain magnetized in different directions. In a disk having a small track pitch, the remaining nonuniform magnetization will cause a cross talk which degrades the signal S/N (signal-to-noise) ratio and hence the signal quality.
To solve this problem, the magneto-optical disk is initial-formatted in the final process of the production or just before shipment from the factory. Generally, the bulk erase method is used for initial formatting of mass-produced magneto-optical disks. In this method, the magneto-optical disks are placed in a furnace at a temperature higher than the Curie point of them to momentarily be heated to a high temperature so that the disk will be magnetized uniformly in the same direction. However, the ultra-high resolution magneto-optical disk such as DWDD type disk, even if processed by the bulk erase method, incurs much noise during information recording or reproduction and shows no good detrack characteristic at the time of disk playback.
Also, the biaxial actuator for focusing and tracking a light beam scanning a magneto-optical disk generally uses an electromagnetic force as the driving force and so it is provided with a magnetic circuit including a magnet. The magnet included in the magnetic circuit produces a leakage flux under the influence of which noises will be increased during recording or reproduction of information to or from the magneto-optical disk.

Disc-shaped recording medium, manufacturing method thereof, and disc drive device


A portable vertical rotary grill includes a support structure, a power source, a motor, and a grill. The support structure is preferably a tripod, but other support structures may also be used. The power source is preferably two D size dry cell batteries. A battery holder is preferably fastened to a top of the motor. The motor assembly is fastened to a top of the support structure with a chain. A thrust bearing is attached to an output shaft of the motor. The thrust bearing is supported by a thrust plate which is fastened to an outer housing of the motor. A chain collar is attached to the output shaft of the motor at an end thereof. A chain with a hook on an end thereof extends downward from the chain collar. The grill is preferably supported by three chains which are equally spaced around the circumference of the grill. The three chains are joined at their ends and placed on the hook.

1. Field of the Invention
The present invention relates generally to rotary grills and more specifically to a portable vertical rotary grill which allows food items to be evenly cooked over a campfire.
2. Discussion of the Prior Art
There are at least two patents directed at providing a vertical rotary grill. U.S. Pat. No. 4,732,138 to Vos discloses several embodiments of campfire cookers and at least one which may be rotated. U.S. Pat. No. 5,297,534 to Louden discloses a stationary vertical rotary grill. Neither of these designs disclose a portable vertical rotary grill which may be operated by two D size batteries.
Accordingly, there is a clearly felt need in the art for a portable vertical rotary grill which may be easily transported from one area to another, vertically rotates a grill surface over a ground fire, and may be driven by two D size batteries.


An electro-optic modulator such as a Mach-Zehnder interferometer has a segmented optical transmission network with a series of discrete electrodes for successive segments of the network. Respective modulating signals are supplied to the electrodes along transmission lines whose lengths differ from each other, so that modulating signals applied to the inputs of the transmission lines arrive at their respective electrodes in synchronism with the propagation of an optical signal through the optical transmission network. The modulating transmission lines are disposed lateral to and generally coplanar with the optical transmission network, preferably on a separate substrate. The desired differential in transmission line lengths can be achieved by positioning the input ends of the transmission lines along an edge of the input substrate that is at a desired angle to the optical transmission network.

1. Field of the Invention
This invention relates to electro-optic modulators in which an optical signal is modulated by an electrical signal, and more particularly to modulators in which segmented modulating electrodes are distributed along an optical network.
2. Description of the Related Art
A trade off must normally be made between bandwidth and power when designing an electro-optic modulator that has an extended optical transmission network, such as a Mach-Zehnder interferometer. Longer modulators result in a narrower bandwidth, while shorter modulators have a greater power consumption.
At frequencies above 2 GHz, the electric signal propagates along with the optical signal down the length of the modulator. This allows the electric signal to interact with the optical signal over the length of the modulator. The reason for the reduction in bandwidth in these traveling wave modulators as the modulator length increases is that the propagation speed of the electrical radio frequency (RF) modulating signal is less than the optical propagation speed through the modulator. The modulator operation begins to degrade when the two signals go more than 180.degree. out of phase with each other before the end of the modulator; the amount of phase differential is proportional to the modulator length. Since RF signals have shorter wavelengths at higher frequencies, and therefore go out of phase with the optical signal more rapidly at such frequencies, longer modulators encounter a high frequency bandwidth limitation.
The additional power requirement of a shorter modulator is related to the depth of modulation, which is the ratio of the difference in optical output intensity between the positive and negative RF peaks (the RF signal normally rides on a DC bias), divided by the maximum optical output intensity with zero modulation. The depth of modulation is directly proportional to the modulation drive voltage times the length of the modulator. It decreases as the modulator length is reduced, since the interaction length of the RF and optical signals is reduced. Accordingly, a stronger modulation drive (i.e., greater RF voltage) is required to maintain the same depth of modulation for a shorter modulator. The power required to produce a given depth of modulation varies inversely with the square of the modulator length.
An extended modulator length with a consequent reduction in the RF drive power is disclosed in Schaffner et al. U.S. Pat. No. 5,005,932, issued Apr. 9, 1991 and assigned to Hughes Aircraft Company, the assignee of the present invention. In this approach a periodic electrode structure is used to match the velocity of the optical signal with that of the dominant RF space harmonic. The RF optical signals are perfectly coherent at one frequency so that the modulator response is high at the design frequency, but away from this frequency the modulator response decreases. The frequency response is thus quite limited.
Another time delay modulator is described in Bridges U.S. Pat. No. 5,076,655, issued Dec. 31, 1991 and assigned to Hughes Aircraft Company, and in Bridges et al., "Wave-Coupled LiNbO.sub.3 Electroptic Modulator For Microwave and Millimeter-Wave Modulation", IEEE Photonics Technology Letters, Vol. 3, No. 2, February 1991, pages 133-135. The electrodes of an electro-optic modulator are divided into short sections, with each section connected to its own antenna on the surface of a common substrate. The antennas are then illuminated from the underside of the substrate by a plane wave that is transmitted through the substrate at an angle to the modulator surface; the angle is chosen so that the phase velocity of the incident modulating wave in the direction of the optical waveguide is equal to that of the optical wave. Each antenna thus receives the proper phase to match the phase velocity of the optical wave. Phase errors are kept small by making the sections short, while power requirements are limited because of the extended length of the overall modulator. A simple phase modulator was disclosed, but the same approach was said to work if applied to one arm of a Mach-Zehnder amplitude modulator.
While the modulator described in the Bridges et al. article achieves a desirable combination of relatively broadband operation coupled with a relatively low power consumption, it requires the presence of an RF transmission antenna on the underside of a LiNbO.sub.3 substrate. The substrate material has a large RF index of refraction, and the receiver antennas therefore collect the RF signal more efficiently than would be the case if the signals were transmitted through the air. The result is a bulky three-dimensional structure that requires a large quantity of relatively expensive LiNbO.sub.3. In addition, the angle of the transmission antenna to the LiNbO.sub.3 substrate is critical and would be difficult to maintain in a system subject to environmental conditions other than those found in the laboratory.

Broad band, low power electro-optic modulator apparatus and method with segmented electrodes


A guiding system for use with translucent textile work pieces is disclosed. A free edge (52) of a tubular work piece extends along a continuous processing path and is folded under the work piece to form a hem in the work piece. The work piece is then advanced along the processing path toward a downstream sewing machine (11), whereupon the hem is sewn in the work piece. A lower ply sensing opposed beam sensor (76) upstream of the sewing machine detects a multiple ply leading edge of the folded hem, and is moved by a pneumatic cylinder (88) into a position laterally with respect to the processing path where it will detect the free edge of the folded and sewn hem, and will control a lower work piece guide assembly (34) so as to maintain a proper depth of the hem. This enables the sewing needles (20) of the sewing machine to align the two spaced parallel lines of stitching (68) at the beginning and end of the hem line for minimizing waste in such hem forming operations.

In the production of garments and other textile products in a high volume industrial assembly process in which the work pieces are sewn together, it is important that the sewing equipment provided to the worker be fast and efficient in its operation, and also that the equipment be capable of being quickly and easily loaded with the work pieces by the worker. Further, it is highly desirable that once the work pieces have been properly loaded in position, and the equipment placed in operation, that the equipment accurately form the desired work piece without errors so that the production of "seconds" is avoided.
In the production of garments and other items which are to be purchased as high quality goods, therefore, it is important that the hems and seams connecting the adjacent work pieces be accurately formed, as by the stitching for a hem extending through the edge portion at the raw edge of a folded hem, rather than allowing the stitching to wander off or away from the edge portion. In those instances where a line of stitching in a continuous hem overruns and merges with itself at the beginning and end of the line of the stitching, it is important that the end of the line of stitching and the beginning of the line of stitching be closely aligned with one another. If the beginning and end of the line of stitching are misaligned where they overlap, an undesirable visual appearance will be created and it is likely that the garment will be considered a "second" and refused by the potential purchaser.
For example, when a folded hem is formed at the waist line of a tubular knitted shirt the typical and desirable stitch formation comprises two lines of parallel stitches formed on the external surface of the garment, with connecting stitches on the rear surface holding the former raw edge portion of the hem in place. It is important, then, to make sure that the parallel stitches at the beginning and at the end of the run of stitches about the garment are aligned as they overlap to create a pleasing visual appearance.
The prior art automated work piece guide systems that form hems in the continuous edges of tubular garments, such as the waist hem of a knitted shirt, do not have the consistent ability to align the work pieces with the sewing machine so that overlapping stitches at the beginning and end of a stitch run are aligned. Also, the line, or lines, of stitching may not be aligned with the raw edge in the hem of the garment because the depth of the hem might vary along its length. These problems seem to be generated because the known prior art devices first guide the unfolded raw edge along the processing path until the edge portion is folded over onto the adjacent body portion to form the hem, and then guide the folded edge of the hem along the processing path to a downstream sewing machine.
A guide system of this general type is disclosed in U.S. Pat. No. 4,497,447. If the tension changes in the work piece during the operation of the equipment, or if the folder does not function perfectly, the depth of the folded edge portion of the hem may vary along the length of the hem causing the raw edge of the garment to wander out of alignment with the stitches as the garment advances through the sewing machine. Moreover, when the sewing of the hem in the work piece begins, the alignment of the work piece and the depth of the fold may not be as accurate at the beginning of the sewing cycle as it will be during the middle and end portions of the cycle, so that the line of stitches formed at the beginning of the stitching function may be displaced to one side or the other of the desired stitch track. In this situation, the beginning and ending stitches of an overlapping stitch run may be misaligned and form an undesirable appearance.
What is needed, therefore, but seemingly unavailable in the art is a guiding system for use with multiple ply seam textile work pieces which will repeatedly, accurately, and quickly guide the folded raw edge portion of a work piece toward a hem forming station, for example, to ensure that a uniform hem is sewn into the work piece, and which will ensure that the lines of stitching remain parallel to and aligned with one another along the raw edge of the work piece.

Method of forming a folded hem and system for guiding a multiple ply seam of a textile work piece


A single-crystal seed, apparatus and process for producing a casting having a single-crystal (SX) microstructure. The seed has a geometry that includes a vertex capable of destabilizing an oxide film that forms at the interface between the seed and a molten metal during the casting process, and thereby promotes a continuous single-crystal grain growth and reduces grain misorientation defects that can initiate from the seed/metal interface.

The present invention generally relates to materials and processes for producing directionally-solidified castings, and particularly to a process and apparatus capable of reducing defects in single-crystal (SX) castings, including but not limited to cast components of gas turbines and other high temperature applications.
Components of gas turbines, such as buckets (blades), nozzles (vanes) and combustor components, are typically formed of nickel, cobalt or iron-base superalloys characterized by desirable mechanical properties at turbine operating temperatures. Because the efficiency of a gas turbine is dependent on its operating temperatures, there is an ongoing effort to develop components, and particularly turbine buckets, nozzles, and combustor components, that are capable of withstanding higher temperatures. As the material requirements for gas turbine components have increased, various processing methods and alloying constituents have been used to enhance the mechanical, physical and environmental properties of components formed from superalloys. For example, buckets, nozzles and other components employed in demanding applications are often cast by unidirectional casting techniques to have directionally-solidified (DS) or single-crystal (SX) microstructures, characterized by an optimized crystal orientation along the crystal growth direction to produce columnar polycrystalline or single-crystal articles.
As known in the art, directional casting techniques for producing DS and SX castings generally entail pouring a melt of the desired alloy into an investment mold held at a temperature above the liquidus temperature of the alloy. One such process is represented in FIGS. 1 and 2 as an apparatus 10 that employs a Bridgman-type furnace to create a heating zone 26 surrounding a shell mold 12, and a cooling zone 42 beneath the mold 12. The zones 26 and 42 may be referred to as "hot" and "cold" zones, respectively, which denote their temperatures relative to the melting temperature of the alloy being solidified. The mold 12 has an internal cavity 14 corresponding to the desired shape of a casting 32 (FIG. 2), represented as a turbine bucket. As such, FIG. 1 represents the cavity 14 as having regions 14a, 14b and 14c that are configured to form, respectively, an airfoil portion 34, shank 36, and dovetail 38 (FIG. 2) of the casting 32. The cavity 14 may also contain cores (not shown) for the purpose of forming internal structures such as cooling passages within the casting 32.
The mold 12 is shown secured to a chill plate 24 and initially placed in the heating zone 26 (Bridgman furnace). The heating zone 26 heats the mold 12 to a temperature above the liquidus temperature of the alloy. The cooling zone 42 is directly beneath the heating zone 26, and operates to cool the mold 12 and the molten alloy 16 within by conduction, convection and/or radiation techniques. For example, the cooling zone 42 may be a tank containing a liquid cooling bath 46, such as a molten metal, or a radiation cooling tank that may be evacuated or contain a gas at ambient or cooled temperature. The cooling zone 42 may also employ gas impingement cooling or a fluidized bed.
An insulation zone 44 defined by a baffle, heat shield or other suitable means is between and separates the heating and cooling zones 26 and 42. The insulation zone 44 serves as a barrier to thermal radiation emitted by the heating zone 26, thereby promoting a steep axial thermal gradient between the mold 12 and the cooling bath 46. The insulation zone 44 has a variable-sized opening 48 that, as represented in FIG. 1, enables the insulation zone 44 to fit closely around the shape of the mold 12 as it is withdrawn from the heating zone 26, through the insulation zone 44, and into the liquid cooling bath 46.
Casting processes of the type represented in FIGS. 1 and 2 are typically carried out in a vacuum or an inert atmosphere. After the mold 12 is preheated to a temperature above the liquidus temperature of the alloy being cast, molten alloy 16 is poured into the mold 12 and the unidirectional solidification process is initiated by withdrawing the base of the mold 12 and chill plate 24 downwardly at a fixed withdrawal rate into the cooling zone 42, until the mold 12 is entirely within the cooling zone 42 as represented in FIG. 2. The insulation zone 44 is required to maintain the high thermal gradient at the solidification front to prevent nucleation of new grains during the directional solidification processes. The temperature of the chill plate 24 is preferably maintained at or near the temperature of the cooling zone 42, such that dendritic growth begins at the lower end of the mold 12 and the solidification front travels upward through the mold 12.
FIGS. 1 and 2 represent a single-crystal seed 28 within a cavity 50 at the bottom of the mold 12. The casting 32 epitaxially grows from the seed 28, such that both the primary and secondary crystal orientations are controlled to yield a single-crystal casting. The seed 28 represented in FIGS. 1 and 2 has a cylindrical shape, which is conventional for directional casting techniques, though other shapes are known. FIGS. 1 and 2 further represent a crystal selector 30 coupling the seed cavity 50 to the mold cavity 14, which ensures that a single crystal enters the cavity 14. A bridge 40 connects protruding sections of the casting 32 with lower sections of the casting 32 so that crystal nucleation at these protruding locations can be suppressed and a unidirectional columnar single crystal forms substantially throughout the casting 32.
Mechanical properties of DS and SX castings depend, to a large degree, on the avoidance of grain misorientation defects, for example, high-angle grain boundaries, equiaxed grains, and other potential defects that may occur as a result of the directional solidification process. The avoidance of such defects in a SX casting depends primarily on whether the crystal orientation of the seed 28 can be successfully extended into the casting 32. For this purpose, the seed 28 must be properly oriented at the bottom of the mold 12. In an ideal situation, when the molten alloy 16 is poured into the mold 12 and makes contact with the seed 28, a portion of the single-crystal seed 28 is re-melted. Then, as the mold 12 is slowly withdrawn from the hot zone 26, continuous epitaxial grain growth occurs to yield a single crystal article with an orientation dictated by the single-crystal seed 28.
Although casting processes of the type represented in FIGS. 1 and 2 are typically carried out in vacuum, a thin oxide film can form at the interface between the molten alloy 16 and the single-crystal seed 28 if the alloy and/or seed 28 contains elements capable of chemically reacting with residual oxygen in the vacuum chamber. It is understood that this oxide film is ceramic in nature and can prohibit continuous grain growth from the seed 28, generate misoriented grains, and cause defects in the final casting 32. The formation of an oxide film at the seed-alloy interface can be inhibited by reducing the availability of oxygen and reactive elements within the alloy. However, most nickel-base superalloys used to form single-crystal castings rely on the presence of aluminum to form Ni3Al (gamma prime) as the primary strengthening phase for alloys used to form articles subjected to high stresses in high temperature environments. For example, René N5 (U.S. Pat. No. 6,074,602) contains about 5 to about 7 weight percent aluminum, and CMSX-10 has a nominal aluminum content of about 5.7 weight percent. The oxide films that form during directional solidification of these alloys have been found to typically be aluminum oxide (Al2O3) mixed with chromium oxide (Cr2O3), nickel monoxide (NiO) and titanium oxide (Ti2O3). Due to the high reactivity of aluminum with oxygen, Al2O3 can form at partial pressures of oxygen being as low as 10−18 at a pouring temperature of about 1500° C., which is equivalent to a vacuum of 10−6 torr if water is assumed to be the only residual gas. However, the vacuum in a Bridgman system is typically not better than 10−3 torr. Furthermore, oxygen may be present as an impurity in the molten alloy 16 and/or seed 28, can be present in the mold 12, and can also form as a result of reactions between the mold 12 and the molten alloy 16.
Aside from excluding aluminum from the alloy being cast, attempts to inhibit the formation of an oxide film at the seed-alloy interface have included excluding aluminum from the seed, as reported in U.S. Pat. No. 6,740,176 and U.S. Published Patent Application No. 2010/0058977. However, if aluminum is a required constituent of the seed and/or the casting alloy, it is very difficult to prevent the formation of an oxide film at the seed-alloy interface.

Unidirectional solidification process and apparatus and single-crystal seed therefor


The invention relates to an apparatus and method for driving high-side switching devices in an H-Bridge circuit. The apparatus includes first and second N-Channel high-side switching devices. Each of the high-side switching devices is associated with, and is selectively driven by, a driver circuit. Each of the driver circuits is associated with, and is powered from, a bootstrap capacitor. The apparatus further includes a cross-couple circuit that is arranged to charge each of the bootstrap capacitors based, at least in part, on whether the low-side switching device that is associated with the other bootstrap capacitor is open or closed.

H-Bridge circuits may be employed as power switching circuits. For example, H-Bridge circuits may be employed as drive circuitry for electrical motors, as drive circuitry for electroluminescent lamp circuits, as DC/AC inverter circuitry, and as regulator output circuitry in switching regulators. Further H-Bridge circuits are employed in a variety of other applications and circuits.
In these and other applications, H-Bridge circuits may be employed to selectively control a direction of current flow through, or the polarity of voltage to, an element. The element may be an inductor, a motor, an electroluminescent lamp circuit, a coil of a transformer, a solenoid, an electrical device, an electrical component, and/or the like.

Bootstrap circuit for H-bridge structure utilizing N-channel high-side fets