The structural and electrical properties of the SrTa2O6/In0.53Ga0.47As/InP system

The structural and electrical properties of SrTa₂O₆(SrTaO)/n-In_0.53GaAs_0.47(InGaAs)/InP structures where the SrTaO was grown by atomic vapor deposition, were investigated. Transmission electron microscopy revealed a uniform, amorphous SrTaO film having an atomically flat interface with the InGaAs substrate with a SrTaO film thickness of 11.2 nm. The amorphous SrTaO films (11.2 nm) exhibit a dielectric constant of ∼20, and a breakdown field of >8 MV/cm. A capacitance equivalent thickness of ∼1 nm is obtained for a SrTaO thickness of 3.4 nm, demonstrating the scaling potential of the SrTaO/InGaAs MOS system. Thinner SrTaO films (3.4 nm) exhibited increased non-uniformity in thickness. From the capacitance-voltage response of the SrTaO (3.4 nm)/n-InGaAs/InP structure, prior to any post deposition annealing, a peak interface state density of ∼2.3 × 10¹³ cm⁻² eV⁻¹ is obtained located at ∼0.28 eV (±0.05 eV) above the valence band energy (E_v) and the integrated interface state density in range E_v + 0.2 to E_v + 0.7 eV is 6.8 × 10¹² cm⁻². The peak energy position (0.28 ± 0.05 eV) and the energy distribution of the interface states are similar to other high-k layers on InGaAs, such as Al₂O₃ and LaAlO₃, providing further evidence that the interface defects in the high-k/InGaAs system are intrinsic defects related to the InGaAs surface.     

Computation of the fluence of fast neutrons in the reactor pressure vessel of Unit I of Kozloduy NPP

The procedure of computation of the fluence of fast neutrons in the pressure vessel of the WWER-440 reactor of Unit I of the Kozloduy NPP, Bulgaria, by the method of the discrete ordinates using the neutron transport code TORT and the cross-section library SAILOR is outlined. The principal results for cycles 16, 17 and 18 are reported, together with a comparison between measured weight specific activities of ⁵⁴Mn (a product of the reaction ⁵⁴Fe(n,p)⁵⁴Mn) in shavings taken from different locations on the inner surface of weld no.4 of the pressure vessel of unit I after the end of cycles 17 and 18 and the corresponding predicted values on the basis of the computed fluence of fast neutrons at these locations.     

1,8‐Naphthalimides as Blue Emitting Fluorophores for Polymer Materials

The copolymerization of 1,8‐naphthalimide derivatives (as fluorophore) with acrylonitrile has been investigated. The photophysical characteristics of monomeric and polymeric fluorophores in N,N‐dimethylformamide solution have been determined and discussed. During copolymerization, no changes in the chromophoric systems of the fluorophore occur. The influence of the studied monomeric 1,8‐naphthalimide fluorophores upon the structurally bleached polyacrylonitrile has been determined. Infrared absorption characteristics of the polymerizable 4‐alkoxy‐ and 4‐allyloxy‐N‐substituted‐1,8‐naphthalimides have been measured and discussed. The effect of the substituents upon the vibration frequencies of the carbonyl and allylic groups has been established.

Blue fluorescent polyacrylonitrile copolymers with 1,8‐naphthalimides side‐group.     

The Anti-Lightning Protection System of the Andyrchi Facility

The system of anti-lightning protection measures set up under the high mountain conditions of the Andyrchi facility at the Baksan Neutrino Observatory of the RAS INR is described. A number of practical recommendations for the anti-lightning protection of the electronic equipment at physics installations that have long lines of communication between their physical quantity sensors and recording instruments are given.     

Synthesis, gastroprotective, antisecretory and anti-Helicobacter effect of N-[3-(3-(1-piperidinylmethyl) phenoxy)propyl]-hydroxyacetamide 2-hydroxypropane-1,2,3-tricarboxylate bismuth (3+) complex (MX1)-MX1

Dental stone molds are convenient for fabricating facial prostheses, but they tend to break when repeatedly used to make duplicate prostheses. This study investigated the use of an inexpensive plastic mesh, die hardener, and PVC pipe segment to reinforce stone mold test samples that were broken in compression on an Instron testing machine. The samples reinforced with PVC pipe surpassed the load limit of the Instron machine. The samples reinforced with both die hardener and mesh were 13% more resistant to breakage than the control samples made of stone alone. Samples reinforced only with mesh were 3% weaker than the control samples.     

Recombinant human glycosylasparaginase catalyzes hydrolysis of L-asparagine

Cryptosporidium parvum causes persistent diarrhea in young children in developing countries. To determine the interaction between nutritional status and cryptosporidiosis, an open cohort of 1064 children younger than 3 y of age was followed for 1441 child-years by weekly diarrhea recall visits. A total of 5072 weight and 4264 height measurements was made. There were no tendencies of low weight (P = 0.38) or height (P = 0.16) in children who acquired cryptosporidiosis. Cryptosporidiosis in infancy was accompanied by an estimated weight loss of 392 g (95% CI: 247, 538 g) in boys and 294 g (95% CI: 109, 479 g) in girls, corresponding to 3.7% and 2.9% of mean weight, respectively, at 2 y of age. No significant catch-up growth covered for this loss in weight. A similar effect in linear growth was shown (P = 0.02). Although it has been suggested that the effect of infections on nutrition is usually transient because of catch-up growth, the present study suggests that cryptosporidiosis in infancy has a permanent effect on growth.     

Joint Russian and Bulgarian Academies of Sciences Database of Intermolecular Potentials and Diffusion Coefficients for Components of the CVD Processes in Microelectronics

The goal of the database (DB) EPIDIF-JRB is to promote the modeling of gas-phase transport processes in CVD technologies in microelectronics. The transport properties (molecular diffusion coefficients, viscosity, and thermal conductivity) of pure gases and gas mixtures in the temperature range 250 to 2000K and at a pressure <0.1MPa are calculated using (1) the Chapman–Enskog method in binary collision approximation and (2) the three-parameter Lennard–Jones (m–6) intermolecular potentials (IP) with 8<m<100 for interactions of atoms and quasi-spherical molecules, and (3) the four-parameter m–6–3 Stockmayer IP for dipole molecules. In addition to the IP parameters a _ii , a _jj , and a _ij , the DB also supplies their variance–covariance matrix. For heavy globular molecules [such as CF₄, SiH₄, Si(CH₃)₄, and WF₆], the influence of the vibrational excitation on their effective size is considered. In this case, the isotropic Lennard–Jones (m–6) IP with temperature-dependent parameters was defined. At present, the DB EPIDIF-JRB contains 40 species of importance to Si gas-phase epitaxy processes and IP parameters for 820 pair interactions. It can be used to calculate the viscosity of pure gases and gas mixtures with any k components (k<11), and their binary diffusion coefficients, and to estimate their uncertainty as well.     

Lipopolysaccharide and interleukin 1 augment the effects of hypoxia and inflammation in human pulmonary arterial tissue

The combined effects of hypoxia and interleukin 1, lipopolysaccharide, or tumor necrosis factor alpha on the expression of genes encoding endothelial constitutive and inducible nitric oxide synthases, endothelin 1, interleukin 6, and interleukin 8 were investigated in human primary pulmonary endothelial cells and whole pulmonary artery organoid cultures. Hypoxia decreased the expression of constitutive endothelial nitric oxide synthase (NOS-3) mRNA and NOS-3 protein as compared with normoxic conditions. The inhibition of expression of NOS-3 corresponded with a reduced production of NO. A combination of hypoxia with bacterial lipopolysaccharide, interleukin 1 beta, or tumor necrosis factor alpha augmented both effects. In contrast, the combination of hypoxia and the inflammatory mediators superinduced the expression of endothelin 1, interleukin 6, and interleukin 8. Here, we have shown that inflammatory mediators aggravate the effect of hypoxia on the down-regulation of NOS-3 and increase the expression of proinflammatory cytokines in human pulmonary endothelial cells and whole pulmonary artery organoid cultures.     

VVER-1000 radial reflector modeling by diffusion nodes

The two commonly used approaches to describe the VVER radial reflectors in diffusion codes, by core-reflector albedos and by a ring of diffusion assembly size nodes, are discussed. The advantages and disadvantages of the first approach are presented first, then the Koebke's equivalence theory is outlined and its implementation for the VVER radial reflectors is discussed. Results for the VVER-1000 reactor are presented.     

Erweiterung des Eigenschaftspotentials der Legierung Al Mg5Si2Mn durch eine gezielte Wärmebehandlung

To enlarge the mechanical properties in castings, appropriate heat treating is essential. Heat treatable aluminium alloys only reach best possible properties as a result of heat treating. This exposition deals with the investigation of an ideal solution heat treatment temperature and artificial ageing parameters for an AlMgSi cast alloy, to be precise MAXXALLOY®—59, in permanent mould casting. The determination of temperature and holding time parameters for the heat treatment have been conducted by relevant literature research, calculations with software Thermo-Calc®, castings and differential scanning calorimetry tests. For verification of ascertained values, extensive microscopic examinations and mechanical tests (tensile tests and measurements of hardness) have been performed. The results indicate that cast parts in heat treated condition and T4 (8 days naturally aged) compared to as-cast parts show remarkable higher tensile, hardness and ductility values. For that reason the chosen parameters for solution annealing, based on scientific examinations, have been proved to be optimal.