Non equilibrium anisotropic excitons in atomically thin ReS2_2

We present a systematic investigation of the electronic properties of bulk and few layer ReS$_2$ van der Waals crystals using low temperature optical spectroscopy. Weak photoluminescence emission is observed from two non-degenerate band edge excitonic transitions separated by $\sim$ 20 meV. The comparable emission intensity of both excitonic transitions is incompatible with a fully thermalized (Boltzmann) distribution of excitons, indicating the hot nature of the emission. While DFT calculations predict bilayer ReS$_2$ to have a direct fundamental band gap, our optical data suggests that the fundamental gap is indirect in all cases

Non equilibrium anisotropic excitons in atomically thin ReS2

We present a systematic investigation of the electronic properties of bulk and few layer ReS2 van der Waals crystals using low temperature optical spectroscopy. Weak photoluminescence emission is observed from two non-degenerate band edge excitonic transitions separated by similar to 20 meV. The comparable emission intensity of both excitonic transitions is incompatible with a fully thermalized (Boltzmann) distribution of excitons, indicating the hot nature of the emission. While DFT calculations predict bilayer ReS2 to have a direct fundamental band gap, our optical data suggests that the fundamental gap is indirect in all cases

Luminescent and scintillation properties of Ce3+ doped Ca2RMgScSi3O12 (R = Y, Lu) single crystalline films

The work is dedicated to the growth and investigation of the luminescent and scintillation properties of single crystalline films (SCFs) of Ca2-xR1+xMg1+xSc1-xSi3O12:Ce (R = Y, Lu) mixed garnets with x = 0-0.25, grown using the liquid phase epitaxy method onto Y3Al5O12 substrates from PbO-B2O3 based flux. The absorption, luminescent and scintillation properties of Ca2-xY1+xMg1+xSc1-xSi3O12:Ce and Ca2-xLu1+xMg1+xSc1-xSi3O12:Ce SCFs with x = 0 and 0.25 were investigated and compared with the reference YAG:Ce and LuAG:Ce SCFs. Using the Ca2+, Mg2+ and Si4+ alloying, the Ce3+ emission spectra in Ca2-xR1+xMg1+xSc1-xSi3O12:Ce (R = Y, Lu; x = 0-0.25) SCFs can be notably extended in the red range in comparison with YAG: Ce and LuAG: Ce SCFs due to the increase of crystal field strength and Ce3+ multicenter creation in the dodecahedral positions of the lattices of these mixed garnet compounds. Due to the formation of Ce4+ ions, the as-grown Ca2-xR1+xMg1+xSc1-xSi3O12:Ce (R = Y, Lu) SCFs at x = 0 and 0.25 show relatively low light yield. However, after annealing in reducing atmosphere (95% N-2 + 5% H-2) at T > 1000 degrees C, a recharging Ce4+ -> Ce3+ takes place. After that, these SCFs possess the light yield about of 30% and 31% in comparison with the reference YAG: Ce and LuAG: Ce SCFs, respectively, and a fast scintillation response with the decay times in the ns range under a-particles excitation by Pu-239 (5.15 MeV) source

Numerical investigations of aviation fuel combustion in the turbine engine GTM-140

Artykuł przedstawia trójwymiarowe obliczenia numeryczne spalania w miniaturowym silniku turbinowym GTM-140. Głównym celem pracy jest zrozumienie procesów zachodzących w zastosowanej komorze spalania. Została przeprowadzona analiza strat przepływu w silniku turbinowym. Przedstawiono wyniki w postaci pól temperatury, ciśnienia oraz prędkości z uwzględnieniem przepływu cold flow oraz przepływu reakcyjnego. Został użyty model turbulencji k-s (RANS), jako model spalania posłużył Non-Premixed Equilibrium Model oraz Dicrete Phase Model jako model z odparowaniem kropel paliwa.This article presents three-dimensional numerical calculations of combustion in the GTM-140 miniature turbine engine. The main aim of this work is to understand the processes occurring in the combustion chamber. Flow losses analysis in the turbine engine was conducted. The paper shows the results as the fields of temperature, pressure and velocity including the "coldflow" and the flow with reaction. The k-s (RANS) Turbulence Model and Non-Premixed Equilibrium Model for combustion was used. The particles of fluid droplets were described by the Discrete Phase Model

Методи проектування турбін радіально-осевого типу для когенереційної установки ORC, що використовує в якості робочого тіла силікатне масло (MDM)

The paper describes two methods of design of blading systems of radial-axial turbines for an Organic Rankine Cycle (ORC) cogeneration unit working with silica oil MDM. Preliminary design of the turbine flow part draws on methods of 1D calculation and pre-selection of basic geometric characteristics. Final design involves also methods for construction of 3D geometry and methods of 3D flow calculations of the turbine flow part. 3D numerical calculations of turbine flows are made with the help of the software package IPMFlow, developed based on the earlier codes FlowER and FlowER-U, or using the software complex ANSYS. 100 kW ORC turbine designs with the single-stage radial-axial turbine are elaborated in this paper.Описано два метода проектирования проточных частей турбин радиально-осевого типа для когонерационной установки, работающей по органическому циклу Ренкина, использующей в качестве рабочего тела силикатное масло (MDM). Предварительное проектирование проточной части основано на методе 1D расчетов и предварительного выбора основных геометрических характеристик. Окончательная доводка геометрии проточной части включает в себя также методы построения 3D геометрии и методов 3D расчета течения в проточной части турбины. Модель 3D турбулентного течения реализована в программном комплексе IPMFlow, который является развитием программ FlowER и FlowER-U и программном комплексе ANSYS. Представлены примеры разработанных проточных частей турбин энергетических машин мощностью 100 кВт.Описано два методи проектування проточних частин турбін радіально-осьового типу для когонераціонной установки, що працює по органічному циклу Ренкіна, та використовує в якості робочого тіла силікатне масло (MDM). Попереднє проектування проточної частини базується на методі 1D розрахунків та попереднього вибору основних геометричних характеристик. Остаточний доведення геометрії проточної частини включає в себе також методи побудови 3D геометрії і методів 3D розрахунку течії в проточній частині турбіни. Модель 3D турбулентної течії реалізована в програмному комплексі IPMFlow, який є розвитком програм FlowER і FlowER-U та програмному комплексі ANSYS. Наведено приклади розроблених проточних частин турбін енергетичних машин потужністю 100 кВт

Iron status and survival in diabetic patients with coronary artery disease

Objective-To investigate the impact of iron status on survival in patients with type 2 diabetes and coronary artery disease (CAD). Research Design and Methods-Serum ferritin, transferrin saturation (Tsat), and soluble transferrin receptor (sTfR) were measured in 287 patients with type 2 diabetes and stable CAD (65 ± 9 years of age, 78% men). Results-During a mean follow-up of 45 ± 19 months, there were 59 (21%) deaths and 60 (21%) cardiovascular hospitalizations. Both serum ferritin and sTfR strongly predicted 5-year all-cause mortality rates, independently of other variables (including hemoglobin, measures of renal function, inflammation, and neurohormonal activation). There was an exponential relationship between sTfR and mortality (adjusted hazard ratio [HR] per 1 log mg/L · 4.24 [95% CI 1.43-12.58], P = 0.01), whereas the relationship between ferritin and mortality was U-shaped (for the lowest and the highest quintiles vs. the middle quintile [reference group], respectively: adjusted HR 7.18 [95% CI 2.03-25.46], P = 0.002, and adjusted HR 5.12 [1.48-17.73], P = 0.01). Similar patterns were observed for the composite outcome of all-cause mortality or cardiovascular hospitalization, and in these multivariable models, low Tsat was related to unfavorable outcome. Conclusions-Both low and high serum ferritin (possibly reflecting depleted and excessive iron stores, respectively) along with high serum sTfR (reflecting reduced metabolically available iron) identify patients with type 2 diabetes and CAD who have a poor prognosis. © 2013 by the American Diabetes Association

Light-Induced Gratings in CdMnTeSe:In Crystals

We show that DX-like centers in Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te$\text{}_{1-y}$Se$\text{}_{x}$:In crystal can be used in writing volume holographic gratings. The scattering efficiency is higher than 10% which proves the dispersive character of the light-induced gratings. Two different metastable centers with different lattice relaxation were found in the crystal. Measurements of the power dependence of the degenerate four-wave mixing scattering efficiency testify that both of these centers have negative U properties