Determination of InN/Diamond Heterojunction Band Offset by X-ray Photoelectron Spectroscopy

Diamond is not only a free standing highly transparent window but also a promising carrier confinement layer for InN based devices, yet little is known of the band offsets in InN/diamond system. X-ray photoelectron spectroscopy was used to measure the energy discontinuity in the valence band offset (VBO) of InN/diamond heterostructure. The value of VBO was determined to be 0.39 ± 0.08 eV and a type-I heterojunction with a conduction band offset (CBO) of 4.42 ± 0.08 eV was obtained. The accurate determination of VBO and CBO is important for the application of III-N alloys based electronic devices.     

Contamination of the transformer oil of power transformers and shunting reactors by metal-containing colloidal particles

The results of a measurement of the contamination of the oil in 66 transformers by metal-containing colloidal particles, formed as a result of the interaction of the oil with the structural materials (the copper of the windings, the iron of the tank and core etc.), and also the results of measurements of the optical turbidity of the oil in 136 transformers when they were examined at the Power Engineering Research and Development Center Company are presented. Methods of determining the concentration of copper and iron in transformer oil are considered. The limiting values of the optical turbidity factors, the copper and iron content are determined. These can serve as a basis for taking decisions on whether to replace the silica gel of the filters for continuously purifying the oil of power transformers and the shunting reactors in addition to the standardized oil contamination factors, namely, the dielectric loss tangent and the acidity number of the oil.     

Preparation of polyester fibre from polyethylene terephthalate modified with caprolactam

Conclusions A process for preparation of modified Lavsan fibre using caprolactam as the modifier has been proposed and has been checked out on the pilot plant of the Mogilevsk Khimvolokno Industrial Association.The introduction of pentamethylene units into the polyethylene terephthalate macromolecules increases the ability of the fibre to sorb disperse dyes. The modified fibre can be dyed at 100°C without carriers, to a tone of medium intensity.In technological processing of the modified polyester fibre, a decrease in thread defectiveness and breakage in the processes of spinning and weaving is observed. In physico-mechanical indices, the thread and finished semi-wool fabric conform to first grade material.The authors express their thanks to coworkers of the Minsk worsted combine for processing the experimental lot of modified polyester.Translated from Khimicheskie Volokna, No. 3, pp. 37–38, May–June, 1989.     

Culture medium for protocorm differentiation in Dendrodium candidum Wall. ex Lindl

Effects of basal culture medium, sucrose concentration, natural extracts and phytohormones on protocorm differentiation were studied. The suitable medium for protocorm differentiation has been found to be 1/2Ms basal medium plus 2% w/v sucrose, 2mg/L BA, 0.2mg/L NAA and 20% (w/v) potato extract.     

Study of Interaction between Technogenic Radionuclides and Floodplain Soils by Partitioning via Sequential Chemical Extraction

Several fractions of technogenic radionuclides were separated from floodplain soil by sequential extraction, among them radiocolloids of ⁶⁰Co and Eu nuclides associated with components of polymeric organomineral films [Fe(III) and Al(III) oxides and hydroxides] and organomineral complexes of ⁶⁰Co, ¹³⁷Cs, and Eu nuclides with humic compounds. Changing the oxidizing agent, H₂O₂, for chromic acid in the sequential extraction procedure allowed a considerable increase in the yield of the radionuclides to the solution: from 6.5 to 46% for ⁶⁰Co, from 1.4 to 36% for ¹³⁷Cs, and from 5.2-8.5 to 23-32% for the Eu isotopes.     

EEG-study of perception of two-dimensional images of three-dimensional objects

We developed a corneal thickness mapping system with ultrasound biomicroscopy (UBM). Perpendicular section ultrasonic echo images of cornea within a radius of 2.5 mm from the center of the cornea in normal eyes were digitized and analyzed with a computer. Pachymetric maps were then represented by a color scale. Individual corneal thickness mapping will be necessary in refractive surgery and helpful in understanding pathologic states.     

Evaluation of the efficacy of thiamine and pyridoxine in the treatment of symptomatic diabetic peripheral neuropathy

Our purpose in this study was to determine the effects of cheilectomy on the mechanics of dorsiflexion of the first metatarsophalangeal (MTP) joint. Ten fresh-frozen cadaver feet were utilized, of which two demonstrated radiographic evidence of hallux rigidus. Each specimen was rigidly mounted on a custom-made slide tray that was articulated with a hinge mechanism designed to dorsiflex the first MTP joint. Range-of-motion measurements were made on the first MTP joint. Cheilectomy of 30% of the metatarsal head diameter was performed. Lateral radiographs with the beam centered on the MTP joint were taken with the joint at neutral, 20 degrees, 40 degrees, and at the limits of dorsiflexion. This process was repeated after a 50% cheilectomy was performed. The radiographs were examined for changes in joint congruence and in patterns of surface motion as the hallux moved from neutral to full dorsiflexion. Instant centers of rotation were determined by a method first described by Rouleaux. We constructed surface velocity vectors to describe patterns of motion of the first MTP joint. The mean dorsiflexion of the first MTP joint was 67.9 degrees and increased to 78.3 degrees after 30% cheilectomy. The increase in dorsiflexion was significantly greater in the two specimens with hallux rigidus (33%) than in the other specimens (12.1%). After both levels of cheilectomy, the proximal phalanx demonstrated pivoting at the resection site on the metatarsal head. This pivoting resulted in abnormal motion patterns across the MTP joint. Normal sliding motion predominated in early dorsiflexion, with compression peaking at the end stage of dorsiflexion, producing jamming of the articular surfaces. Cheilectomy significantly increased dorsiflexion of the MTP joint, but resulted in abnormal motion patterns. The increase in dorsiflexion resulted from pivoting of the proximal phalanx on the metatarsal head, resulting in anomalous velocity vectors and compression across the MTP joint.