Pyroelectric detector arrays

A pyroelectric detector array and the method for using it are described. A series of holes formed through a silicon dioxide layer on the surface of a silicon substrate forms the mounting fixture for the pyroelectric detector array. A series of nontouching strips of indium are formed around the holes to make contact with the backside electrodes and form the output terminals for individual detectors. A pyroelectric detector strip with front and back electrodes, respectively, is mounted over the strips. Biasing resistors are formed on the surface of the silicon dioxide layer and connected to the strips. A metallized pad formed on the surface of layer is connected to each of the biasing resistors and to the film to provide the ground for the pyroelectric detector array

Reusable thermal cycling clamp

A reusable metal clamp for retaining a fused quartz ampoule during temperature cycling in the range of 20 deg C to 1000 deg C is described. A compressible graphite foil having a high radial coefficient of thermal expansion is interposed between the fused quartz ampoule and metal clamp to maintain a snug fit between these components at all temperature levels in the cycle

Schistosomiasis and malignancy

It is generally accepted that schistosomiasis, if not causative, is at least associated with malignancy. In this review, the epidemiology of schistosomiasis and bladder carcinoma, as well as the role of chronic bladder infection, are discussed togetherwith known carcinogenic factors, possible abnormal vitamin metabolism and/or deficiencies and factors that influence conjugated carcinogens. Experimental evidence is briefly examined and recent work from the Far East on schistosomiasis and colon carcinoma reviewed

Temperature profiles in high gradient furnaces

Accurate temperature measurement of the furnace environment is very important in both the science and technology of crystal growth as well as many other materials processing operations. A high degree of both accuracy and precision is acutely needed in the directional solidification of compound semiconductors in which the temperature profiles control the freezing isotherm which, in turn, affects the composition of the growth with a concomitant feedback perturbation on the temperature profile. Directional solidification requires a furnace configuration that will transport heat through the sample being grown. A common growth procedure is the Bridgman Stockbarger technique which basically consists of a hot zone and a cold zone separated by an insulator. In a normal growth procedure the material, contained in an ampoule, is melted in the hot zone and is then moved relative to the furnace toward the cold zone and solidification occurs in the insulated region. Since the primary path of heat between the hot and cold zones is through the sample, both axial and radial temperature gradients exist in the region of the growth interface. There is a need to know the temperature profile of the growth furnace with the crystal that is to be grown as the thermal load. However it is usually not feasible to insert thermocouples inside an ampoule and thermocouples attached to the outside wall of the ampoule have both a thermal and a mechanical contact problem as well as a view angle problem. The objective is to present a technique of calibrating a furnace with a thermal load that closely matches the sample to be grown and to describe procedures that circumvent both the thermal and mechanical contact problems

Numerical modeling of Bridgman growth of PbSnTe in a magnetic field

In this work we study heat and mass transport, fluid motion, and solid/liquid phase change in the process of steady Bridgman growth of Pb(.8)Sn(.2)Te (LTT) in an axially-imposed uniform magnetic field under terrestrial and microgravity conditions. In particular, this research is concerned with the interrelationships among segregation, buoyancy-driven convection, and magnetic damping in the LTT melt. The main objectives are to provide a quantitative understanding of the complex transport phenomena during solidification of the nondilute binary of LTT, to provide estimates of the strength of magnetic field required to achieve the desired diffusion-dominated growth, and to assess the role of magnetic damping for space and earth based control of the buoyancy-induced convection. The problem was solved by using FIDAP and numerical results for both vertical and horizontal growth configurations with respect to the acceleration of gravity vector are presented

Book Reviews

Principles of Cardiac Arrhythmias. 3rd ed. By Edward K. Chung. Pp. xiii 809. Illustrated. Baltimore: Williams &Wilkins. 1983.Ethical Issues in Reproductive Medicine. Ed. by M. Reidy. Pp. 176. Illustrated. RI9,60. Dublin: Gill & Macmillan. 1982.From Parasitic Infection to Parasitic Disease (Contribution to Microbiology and Immunology, vol. 7). Ed. by P. L. Gigase and E. A. C. van Marck. Pp. ix + 269. Illustrated. DM 216,-. Basle: S. Karger. 1983.Prolonged Arrest of Cancer (New Horizons in Oncology, vol. I). Ed. by B. A. Stoll. Pp. xiv + 454. Illustrated. £25,75. London: John Wiley. 1982.Pediatric Angiography. Ed. by P. Stanley. Pp. xv + 425. Illustrated. Baltimore: Williams & Wilkins. 1982.Thin-needle Aspiration Biopsy (Major Problems in Pathology, vol. 14). By W. J. Frable. Pp. X\'iii + 358. Illustrated. £42,25. Philadelphia: \'(t B. Saunders. 1983.Essentials of Pulmonary Medicine. By M. H. Williams. Pp. xi + 190. Illustrated. Philadelphia: W. B. Saunders. 1982.Noninvasive Assessment of the Cardiovascular System: Diagnostic Principles and Techniques. Ed. by E. B. Diethrich. Pp. xxiii + 319. Illustrated. £25,75. London: Wright PSG. 1982.Periodic Abstinence for Family Planning. Ed. by R. L. Kleinman. Pp. 60. Illustrated. £1,75 (in K only). London: IPPF Medical Publications. 1983

Semantic Context Forests for Learning-Based Knee Cartilage Segmentation in 3D MR Images

The automatic segmentation of human knee cartilage from 3D MR images is a useful yet challenging task due to the thin sheet structure of the cartilage with diffuse boundaries and inhomogeneous intensities. In this paper, we present an iterative multi-class learning method to segment the femoral, tibial and patellar cartilage simultaneously, which effectively exploits the spatial contextual constraints between bone and cartilage, and also between different cartilages. First, based on the fact that the cartilage grows in only certain area of the corresponding bone surface, we extract the distance features of not only to the surface of the bone, but more informatively, to the densely registered anatomical landmarks on the bone surface. Second, we introduce a set of iterative discriminative classifiers that at each iteration, probability comparison features are constructed from the class confidence maps derived by previously learned classifiers. These features automatically embed the semantic context information between different cartilages of interest. Validated on a total of 176 volumes from the Osteoarthritis Initiative (OAI) dataset, the proposed approach demonstrates high robustness and accuracy of segmentation in comparison with existing state-of-the-art MR cartilage segmentation methods.Comment: MICCAI 2013: Workshop on Medical Computer Visio

Microgravity science at Langley Research Center

Although space research is still in an embryonic state, a combination of Earth based and space flight experiments are being coupled to yield a better understanding of the complex interaction of heat and fluid flow on the dynamics of crystal growth. Continued efforts on the ground as well as additional flight opportunities are needed to continue the drive to fully understand the advantages, both scientifically and economically, of microgravity crystal growth

Automated segmentation and analysis of normal and osteoarthritic knee menisci from magnetic resonance images: data from the Osteoarthritis Initiative

OBJECTIVE: To validate an automatic scheme for the segmentation and quantitative analysis of the medial meniscus (MM) and lateral meniscus (LM) in magnetic resonance (MR) images of the knee