Search

One of the disadvantages of applying an a-Si:H thin-film transistor (TFT) to an active matrix-addressed liquid crystal (LC) panel is that a TFT with an a-Si:H has a very large photo-leakage current because of the high photo-conductivity of an a-Si:H itself.

The observation of the as-grown crystal surface is an important way of investigating the epitaxial growth mechanism. There are a number of studies on the two-dimensional crystal growth by examining the stacking faults, growth spirals and stacking fault shadows on the as-grown silicon and germanium crystal surfaces. Although a perfect crystal is essential for the manufacture of electronic devices, crystal growth would not proceed without imperfections. Screw dislocations are regarded as constituting the growth nucleus. While the screw structure accompanied by stacking faults is frequently found, the growth nucleus generated by simple screw dislocations is seldom observed. In previous work, we have reported that perfect crystal growth can be achieved by forming defect-free pyramidal hillocks using the temperature pulsing method. Spiral growth layers, stacking faults and the stacking fault shadows on the as-grown III–V compound semiconductor surfaces grown by vapor- and liquid-phase epitaxy have been already reported. This paper presents our recent study of spiral growth layers and the circular growth nucleus.

Abstract: This paper presents theoretical and experimental methods of finding the residual stress in an epoxy plate subjected to rapid cooling on both surfaces. The theoretical residual-stress distributions in a plate are calculated by using the fundamental equations based on the linear viscoelastic theory. The specimens in the experiment are subjected to rapid cooling. The residual stresses are measured by the layer-removal method. The theoretical and experimental results are compared and discussed.

We determine the pressure distribution behind a soft contact lens that is necessary to keep the lens in conformity with an axisymmetric substrate. The substrate consists of two regions: a central portion, the cornea, supposed to be an ellipsoid; and a peripheral region, the sclera, taken to be a sphere. The pressure is obtained as part of a numerical solution of the axisymmetric equilibrium equations for an initially curved, linearly elastic membrane. The relaxed shape of the lens is assumed to be an axisymmetric ellipsoid with a central curvature and a shape factor different from those of the cornea. The variation in the thickness of the lens from its center to edge is approximated by a polynomial. Pressure distributions are obtained for several typical soft contact lens fittings.

Some binary operations of fuzzy numbers are reviewed and a limit of a sequence of fuzzy numbers is defined. Based on these concepts and properties, finite and countable fuzzy random variables are considered and a convergence property of a sequence of fuzzy random variables is shown.

Abstract: This paper discusses the warp and accompanying residual stress in a rectangular epoxy beam produced by water cooling its lower surface. First, the theoretical values of this warp and residual stress are obtained by the linear-viscoelastic theory. The specimen is then subjected to quenching. The variations in the warp are observed. After quenching, the residual stress is measured by a layer-removal method. The experimental and theoretical results are then compared and discussed.

Abstract: The residual stress generated by the molding process of thermosetting resins exerts serious influences upon their mechanical properties. This residual stress is generally classified by two groups: one produced by shrinkage in the curing reaction of monomers, the other produced by the nonuniformity of the temperature distribution in the cooling process. This paper is concerned with the theoretical and experimental analysis of the generation of residual stress of the latter type, using examples of rectangular beams of thermosetting resins quenched on both the upper and lower surfaces. First, a viscoelastic model is applied to make a qualitative prediction of the residual stress in quenched beams.Second, using linear-viscoelastic theory, fundamental equations are derived for the residual stress in a viscoelastic rectangular beam, where an unsteady and nonuniform temperature distribution is assumed in the direction of depth. The theoretical values of the residual stress in rectangular beams are calculated under various quenching conditions for two resins having different viscoelastic characteristics, i.e., epoxy and unsaturated polyester. The theoretical residual-stress distributions agree fairly well with the residual stress measured experimentally at every quenching condition for both resins. The qualitative prediction that the residual stress in quenched beams is compressive in the vicinity of the upper and lower surfaces and is tensile in the inner parts is confirmed. The relaxation modulus of epoxy resin changes more greatly with time and temperature than that of unsaturated polyester resin. The theoretical and experimental analysis shows that the residual stress for the former resin is larger than that for the latter. Therefore, it is concluded that the generation of residual stress is more significant where the relaxation modulus of resin changes greatly with time and temperature.

An 83-year-old morbid woman presented with progredient dyspnoea (New York Heart Association [NYHA] stage IV) and a history of recurrent pulmonary oedema. Owing to type A aortic disection, she underwent aortic surgery 3 years prior (January 2009), which included supracoronary ascending aortic replacement and a proximal aorta-to-prosthesis anastomosis. Transthoracic echocardiography revealed major pulmonary hypertension with an estimated systolic pulmonary pressure of 70-75 mm Hg and severe tricuspid regurgitation. Further investigation, including computed tomography and 3-D transoesophageal echocardiography, revealed rupture of the aortic prothesis with a fistula of the paraprosthetic lumen to the right pulmonary artery. Because of multiple concomitant diseases and severe right-sided heart failure, an interventional approach was initiated. With a complex 3-D-echo-guided intervention, the fistula was successfully closed using a 12-mm Amplatzer ASD Occluder which resulted in a reduction in shunt volume. Postinterventional imaging showed the correct position of the occluder with only a minor residual flow. At 18 months' follow-up, the patient presented with improvement of the preexisting dyspnoea, from NYHA stage IV to NYHA stage II or III. The cardiac ultrasound result indicated a reduction in estimated systolic pulmonary pressure to 45-50 mm Hg. Figure

Background: Mucopolysaccharidosis(MPS) is an autosomal recessive lysosomal storage disorder . Purpose : To describe cardiovascular disease in four patients with MPS Methods: Case 1: A 14-year-old boy, was refered to our echocardiographic laboratory for the follow-up of valvulopathy in the context of Hurler –Scheie MPS I Echocardiography revealed thickening of the mitral valve with increase of the mitral stenosis tricuspid regurgitation and pulmonary hypertension since 2012. Case 2 : A 9-year-old boy (Hurler, MPS I) had history of respiratory failure, coarse facial features, otitis, Umbilical and scrotal hernia. we observe an excessive tissue of the mitral valve with mitral and tricuspid regurgitation pulmonary hypertension on echocardiography. Case 3: A 10-year-old girl (Hurler, MPS I) had an history of glaucoma, Corneal opacities, articular steepness, umbilical hernia and carpal tunnel syndrome. Auscultation revealed mid systolic murmur in the apex and we observe an increase in thickening of the mitral valve with regurgitation and stenosis, and pulmnary hypertension. Case 4 : A 4-year-old boy with Hunter syndrome (MPS II) an history of articular steepness and umbilical hernia. Echocardiography shows an aspect of left ventricular dilatation with globally reduced contraction, central mitral regurgitation and increased distance between Emitral and septum. Conclusion: They are common MPS features including cardiac valve disease, coarse facial features, hepatosplenomegaly, joint restriction and corneal clouding. Hurler, MPS I and Hurler-Scheie have common features regarding cardiovascular disease as thickening of the mitral valve with regurgitation and mitral stenosis who differ from the Hunter syndrom, MPS type II. Figure MPS type I Hurler

The glass formation range in the title system has been investigated and the acid (2.5% HNO3, 1% citric acid) resistivity of the (PbO stabilized) glasses has been determined by weight‐loss measurements.

(a few to about 100 ppm Na) have been carried out by measurements of the C‐V characteristics of metal‐glass‐silicon (MGS) capacitors and stability tests of glass‐passivated diodes.