New physical principles of contact thermoelectric cooling

We suggest a new approach to the theory of the contact thermoelectric cooling (Peltier effect). The metal-metal, metal-n-type semiconductor, metal-p-type semiconductor, p-n junction contacts are analyzed. Both degenerate and non-degenerate electron and hole gases are considered. The role of recombination in the contact cooling effect is discussed by the first time.Comment: 8 pages, 8 figures, revtex

The Nature of Thermopower in Bipolar Semiconductors

The thermoemf in bipolar semiconductors is calculated. It is shown that it is necessary to take into account the nonequilibrium distribution of electron and hole concentrations (Fermi quasilevels of the electrons and holes). We find that electron and hole electric conductivities of contacts of semiconductor samples with connecting wires make a substantial contribution to thermoemf.Comment: 17 pages, RevTeX 3.0 macro packag

Excitation gap of a graphene channel with superconducting boundaries

We calculate the density of states of electron-hole excitations in a superconductor/normal-metal/superconductor (SNS) junction in graphene, in the long-junction regime that the superconducting gap is much larger than the Thouless energy. If the normal region is undoped, the excitation spectrum consists of neutral modes that propagate along the boundaries - transporting energy but no charge. These ``Andreev modes'' are a coherent superposition of electron states from the conduction band and hole states from the valence band, coupled by specular Andreev reflection at the superconductor. The lowest Andreev mode has an excitation gap, which depends on the superconducting phase difference across the SNS graphene channel. At high doping the excitation gap vanishes and the usual gapless density of states of Andreev levels is recovered. We use our results to calculate the superconducting phase dependence of the thermal conductance of the graphene channel.Comment: 8 pages, 10 figure

Damage buildup in Si under bombardment with MeV heavy atomic and molecular ions

Accumulation of structural disorder in Si bombarded at −196 °C with 0.5 MeV ²⁰⁹Bi₁ and 1 MeV ²⁰⁹Bi₂ ions (the so-called molecular effect) is studied by Rutherford backscattering/channeling spectrometry. Results show that the damage buildup is sigmodal even for such heavy-ion bombardment at liquid nitrogen temperature. This strongly suggests that, for the implant conditions of this study, the buildup of lattice damage cannot be considered as an accumulation of completely disordered regions. Instead, damage-dose curves are well described by a cascade-overlap model modified to take into account a catastrophic collapse of incompletely disordered regions into an amorphous phase after damage reaches some critical level. Results also show that Bi₂ ions produce more lattice damage than Bi₁ ions implanted to the same dose. The ratio of lattice disorder produced by Bi₂ and Bi₁ ions is 1.7 near the surface, decreases with depth, and finally becomes close to unity in the bulk defect peak region. Parameters of collision cascades obtained using ballistic calculations are in good agreement with experimental data. The molecular effect is attributed to a spatial overlap of (relatively dense) collision subcascades, which gives rise to (i) nonlinear energy spike processes and/or (ii) an increase in the defect clustering efficiency with an effective increase in the density of ion-beam-generated defects.Research at StPSTU was supported in part by the Ministry for General and Professional Education of the Russian Federation

Biofeedback treatment of proctogenic constipation in adults

Aim of investigation. To study efficacy of biological feedback treatment (BFT) at proctogenic constipation in adult patients.Material and methods. Overall 30 patients with proctogenic constipation and dyssynergia of pelvic floor muscles i.e. spasm of puborectalis muscle were included in original study and treated by BFT method. Mean age of patients was 31,2±9,8 year, men to women ratio was 1:5.Results. During treatment decrease in difficulty to defecate according to Rome-III criteria was observed in 22 (73,3%) patients. The other 8 (26,7%) patients demonstrated no improvement. According to subjective assessment of rectal evacuatory function by questioning before and after BFT statistically significant reduction of proctogenic constipation symptoms was revealed. By the data of objective investigation (profilometry and electromyography) signs of dyssynergia of pelvic floor muscles were revealed in no patient.Conclusions. The biological feedback is effective treatment method for proctogenic constipation, allowing to reduce symptoms in 73,3% of patients and to correct dyssynergia of pelvic floor muscles in all cases

Experience of rectosacropexy in treatment of patients with rectum prolapse

Aim of investigation. To analyze authors’ experience of rectosacropexy results at prolapse of the rectum. Material and methods. Original study included 137 patients who underwent surgery for prolapse of rectum in the State scientific center of coloproctology from January, 2007 to December, 2013. The main group have included 60 patients (43,8%) who had rectosacropexy, control group included 77 patients (56,2%) after back loop rectopexy.Results. Control examination was carried out in 24 patients (40%) of the main and in 26 patients (33,8%) of the control group. Average time of follow-up was respectively 9,8±2,0 months and 34,2±17,8 months. Relapse was diagnosed in 2 patients (7,6%) after back loop rectopexy. After surgical treatment of rectal prolapse statistically significant improvement of anal sphincter pressure was diagnosed in both groups at I and II degree of sphincter insufficiency. Application of rectosacropexy corrects pelvic floor descent syndrome and evacuatory function of the rectum. No deterioration of large intestinal transit after rectosacropexy was revealed (р>0,05). After back loop rectopexy deterioration of large intestinal emptying (р<0,05) was significant.Conclusions. Rectosacropexy is effective method of rectum prolapse treatment and improves function of anal sphincter in postoperative period, corrects pelvic floor descent syndrome and cause no constipation

Modern approaches to carrying out profound medical examination of servicemen of Security Service of Ukraine.

The study found that the regulatory framework for prophylactic medical examination in the Security Service of Ukraine (SSU) is not fully regulated, this required the development and validation of a new organizational model to improve its efficiency. In the coursw of study proposals for the introduction of a modern model of profound medical examinations of the personnel of the SSU were prepared, their main elements are: first developed and implemented model of a motivated individual responsibility of SSU serviceman for their own health, its conservation, inclination to treatment of identified pathological conditions; development and implementation of military health passport, health passport of managers, health passport of agency, division, institution of the SSU; the definition of the various bulks of the annual medical examination of personnel, depending on age (with expansion of screening tests, depending on the age group); introduction of personal responsibility of heads (managers) of bodies (departments and agencies) of the SSU for the timely undergoing of profound medical examinations by subordinate personnel a clear definition of heads’ responsibilities of health care organs (doctors and medical staff) of the SSU in the profound medical examinations; the development and implementation of a unified system of analysis of the results of medical care facilities of SSU for carrying out of medical examination and definition of its efficiency, the introduction of optimized system for monitoring of undergoing medical examination, reporting on undergoing of profound medical examinations by personnel of agencies, departments, institutions of the SSU. This allowed not only to justify organizational model on improvement of clinical examination of the SSU personnel but to introduce it into the work of all health facilities of the SSU, to significantly optimize conducting clinical examination and improve its performance indicators