USE PROSPECTS IN MICROELECTRONICS FOR POLYCRYSTALLINE SILICON FILM STRUCTURES WITH p–n JUNCTION

The paper discusses perspectives of elaborating microelectronic and optoelectronic devices on polycrystalline silicon films. The I-V features of structures with p-n-junction, formed by using methods of р-type conductivity layer grow, thermal diffusion and ion-implantation of boron atoms into n-type polycrystalline silicon layer are compared. The I-V feature with S-form curve of the investigated structures conditioned by changing of the conductivities of base and grain boundaries under thermal processing are revealed.Polycrystalline silicon, grain boundaries, ion-implantation, microelectronics, negative differential resistance, photodiode, I-V characteristics, Research and Development/Tech Change/Emerging Technologies,

Experimental analytical study of parameters of a discharge positive column in mixture He – Hg

© Research India Publications. The article gives results of probe measurements of parameters of a discharge positive column in gas mixture He - Hg under medium pressures. For the same conditions the author calculated the function of electron distribution by velocities taking into account elastic and non-elastic collisions of electrons with gas mixture atoms and found average energy and drift velocity for electrons. Gas mixture parameters estimation results are compared with data obtained from the probe measurements. The article covers the case when the main component of a mixture is helium, and mercury is given in the form of a minor additive

On solving a linear control problem

The problem of a linear regulator is considered. There is a system of linear differential equations with a quadratic control quality criterion. The method of dynamic programming is applied to the solution of the considered linear problem. As is known, the main difficulty in applying this method is to integrate partial differential equations. In this problem, the obtained optimal control function depends on the solution of the Riccati equation. In [1], conditions were obtained under which there is a solution to such optimal control problems with a quadratic quality criterion. These conditions were obtained along with formulas for minimizing control and for optimal trajectory. But all these statements depended on the ability to solve the matrix Riccati equation under certain boundary conditions given at some time point. To construct a solution to the problem under consideration, a system of 2 n adjoint differential equations is constructed. After splitting the transition matrix of this system into block ones, it is possible to express the state of the system at the time instant t through the state variable and the adjoint variable at the final time instant t 1. A feature of this work is that an example is given, where the solution of the Riccati equation, which determines the optimal solution of the problem, was obtained explicitly

The digital ultrasonic interferometer for quality inspection of piezoelectric crystals

© Medwell Journals, 2016.Researcher refers to hypersonic measurement technique. A digital hypersonic method for quality inspection of piezoelectric crystals. The method is grounded on automatic metering of a time interval between echo pulses and Supersonic Wave Attenuation (SWA) in an inspected article with information output in a digital form. The hardware and functional features of hypersonic system is presented. The method can be used in factory and scientific laboratories to obtain express-information on quality of ingoing materials for fabricated items

Generalized differential transformation method for solving two-interval Weber equation subject to transmission conditions

The main goal of this study is to adapt the classical differential transformation method to solve new types of boundary value problems. The advantage of this method lies in its simplicity, since there is no need for discretization, perturbation or linearization of the differential equation being solved. It is an efficient technique for obtaining series solution for both linear and nonlinear differential equations and differs from the classical Taylor’s series method, which requires the calculation of the values of higher derivatives of given function. It is known that the differential transformation method is designed for solving single interval problems and it is not clear how to apply it to many-interval problems. In this paper we have adapted the classical differential transformation method for solving boundary value problems for two-interval differential equations. To substantiate the proposed new technique, a boundary value problem was solved for the Weber equation given on two non-intersecting segments with a common end, on which the left and right solutions were connected by two additional transmission conditions

Molecular characterization of Echinococcus granulosus isolates from Bulgarian human cystic echinococcosis patients

Although cystic echinococcosis (CE) is highly endemic in Bulgaria, there is still scarce information about species and/or genotypes of the Echinococcus granulosus complex that infect humans. Our study tackled the genetic diversity of E. granulosus complex in a cohort of 30 Bulgarian CE patients. Ten animal E. granulosus isolates from neighboring Greece were additionally included. Specimens were comparatively analyzed for partial sequences of five mitochondrial (mt) (cox I, nad I, rrnS, rrnL, and atp6) and three nuclear (nc) genes (act II, hbx 2, and ef-1α) using a PCR-sequencing approach. All 30 Bulgarian isolates were identified as E. granulosus sensu stricto (s.s.) and were showing identical sequences for each of the three examined partial nc gene markers. Based upon concatenated sequences from partial mtDNA markers, we detected 10 haplotypes: 6 haplotypes (H1-H6) clustering with E. granulosus s.s. (G1) and 4 haplotypes (H9-H13) grouping with E. granulosus s.s. (G3), with H1 and H10 being the most frequent in Bulgarian patients. The haplotypes H1, H4, and H11 were also present in Greek hydatid cyst samples of animal origin. In conclusion, E. granulosus s.s. (G1 and G3 genotypes) is the only causative agent found so far to cause human CE in Bulgaria. However, further studies including larger sample sizes and other additional geographic regions in Bulgaria will have to be performed to confirm our results

Rotational dynamics of copper(II) amino acid complexes by EPR and NMR relaxation methods

Rotational dynamics of the copper(II) bis-complexes with glycine and L-aspartic acid has been studied by EPR and NMR relaxation methods in aqueous solutions at several temperatures. Dynamical parameters obtained by EPR were compared with nuclear magnetic relaxation dispersion (NMRD) results and were found to be in a good agreement. From EPR data dominating trans isomer for Cu(Gly)2 and cis isomer for Cu(L-Asp)2 2- was found. On the basis of distance of closest approach of protons to central ion inferred from NMRD and crystal structure data the average slope angles of axial water molecule to equatorial plane were calculated and axial coordination of only one water molecule in the Cu(L-Asp)2 2- complex was established

Point-of-Care Ultrasound Assessment of Tropical Infectious Diseases—A Review of Applications and Perspectives

The development of good quality and affordable ultrasound machines has led to the establishment and implementation of numerous point-of-care ultrasound (POCUS) protocols in various medical disciplines. POCUS for major infectious diseases endemic in tropical regions has received less attention, despite its likely even more pronounced benefit for populations with limited access to imaging infrastructure. Focused assessment with sonography for HIV-associated TB (FASH) and echinococcosis (FASE) are the only two POCUS protocols for tropical infectious diseases, which have been formally investigated and which have been implemented in routine patient care today. This review collates the available evidence for FASH and FASE, and discusses sonographic experiences reported for urinary and intestinal schistosomiasis, lymphatic filariasis, viral hemorrhagic fevers, amebic liver abscess, and visceral leishmaniasis. Potential POCUS protocols are suggested and technical as well as training aspects in the context of resource-limited settings are reviewed. Using the focused approach for tropical infectious diseases will make ultrasound diagnosis available to patients who would otherwise have very limited or no access to medical imaging

Progress in space weather modeling in an operational environment

YesThis paper aims at providing an overview of latest advances in space weather modeling in an operational environment in Europe, including both the introduction of new models and improvements to existing codes and algorithms that address the broad range of space weather's prediction requirements from the Sun to the Earth. For each case, we consider the model's input data, the output parameters, products or services, its operational status, and whether it is supported by validation results, in order to build a solid basis for future developments. This work is the output of the Sub Group 1.3 "Improvement of operational models'' of the European Cooperation in Science and Technology (COST) Action ES0803 "Developing Space Weather Products and services in Europe'' and therefore this review focuses on the progress achieved by European research teams involved in the action