Exploring the Unitarity Triangle through CP violation observables in Bs→K+K−B_s \to K^+ K^-

We discuss the determination of the CKM parameters from the forthcoming $CP$ violation observables in $B_s \to K^+ K^-$ decays. Combining the information on mixing induced CP violation in $B_s \to K^+ K^-$, with the $B_d \to J/\psi K_s$ precision observable $\sin 2\beta$ and the $B^0_s$--$\bar{B^0_s}$ mixing phase $\phi_s$, we propose a determination of the unitarity triangle $(\bar\rho, \bar\eta)$. Computing the penguin parameters $(r, \theta)$ within QCD factorization yield precise determination of $(\bar\rho, \bar\eta)$, reflected by a weak dependence on the $\theta$ which is shown as a second order effect. The impact of the direct CP violation observable $C_{KK}$ on the penguin parameters are investigated and a lower bound on $C_{KK}$ is extracted. We also discuss the effect of the $B^0_s$--$\bar{B^0_s}$ new physics mixing phase on the penguin parameters $(r, \theta)$ and $S_{KK}$. Using the SU(3)-flavour symmetry argument and the current $B$-factories data provided by the $B_d \to \pi^+ \pi^-$ modes, we complement the $B_s \to K^+ K^-$ CP-violating observables in a variety of ways, in particular we find that $S_{KK}>0$. Finally we analyze systematically the SU(3)-symmetry breaking factor within QCD factorization.Comment: 22 pages, 6 figures, typos corrected, reference and some remarks adde

South African HIV-1 Subtype C Transmitted Variants With A Specific V2 Motif Show Higher Dependence On aα4β7 For Replication

Background: The integrin aα4β7 mediates the trafficking of immune cells to the gut associated lymphoid tissue (GALT) and is an attachment factor for the HIV gp120 envelope glycoprotein. We developed a viral replication inhibition assay to more clearly evaluate the role of aα4β7 in HIV infection and the contribution of viral and host factors. Results: Replication of 60 HIV-1 subtype C viruses collected over time from 11 individuals in the CAPRISA cohort were partially inhibited by antibodies targeting aα4β7. However, dependence on aα4β7 for replication varied substantially among viral isolates from different individuals as well as over time in some individuals. Among 8 transmitted/founder (T/F) viruses, aα4β7 reactivity was highest for viruses having P/SDI/V tri-peptide binding motifs. Mutation of T/F viruses that had LDI/L motifs to P/SDI/V resulted in greater aα4β7 reactivity, whereas mutating P/SDI/V to LDI/L motifs was associated with reduced aα4β7 binding. P/SDI/V motifs were more common among South African HIV subtype C viruses (35%) compared to subtype C viruses from other regions of Africa

Investigation of magnetohydrodynamic slip flow for Maxwell nanofluid over a vertical surface with Cattaneo-Christov heat flux in a saturated porous medium

Recently, there has been considerable attention given to a sophisticated fluid system known as the Maxwell nanofluid, which incorporates chemical reactions and the Cattaneo-Christov heat flux. This system has garnered significant interest due to its potential significance in various fields, including heat transfer, chemical engineering, and nanotechnology. Therefore, this numerical investigation proposes a new model for the steady two-dimensional flow of a homogeneous Maxwell nanofluid towards a vertical stretching sheet that incorporated within a porous medium, aimed at revealing the fluid's dynamic and thermal characteristics. The model is specifically tailored for nanofluids and includes thermal radiation, chemical reactions and slip conditions. It is presumed that the viscosity of the Maxwell nanofluid changes with variations in temperature. The governing partial differential equations and corresponding boundary conditions for the nanofluid flow problem are derived in a suitable manner, based on physically valid assumptions and validated experimental correlations. MATHEMATICA software is used to perform arithmetic simulations of the energy, mass concentration, and momentum equations. The simulations are carried out using the fourth-order Runge-Kutta technique in conjunction with the shooting method. Numerical and visual techniques are utilized to examine how the physical parameters that control the model influence it. Subsequent to evaluating our data against prior findings, the reliability and precision of the proposed method are verified. The findings show that the nanofluid's velocity detracts when the slip velocity, Maxwell parameter, magnetic forces, viscosity parameter, and porous parameter rise. The temperature field, which is affected by these parameters, shows the opposite tendency, on the other hand. In addition, the suction parameter application results in a drop in the concentration, temperature, and velocity of the nanofluid

Preparation of N-Si-P-GaSe Heterojunctions Based on an Amorphous GaSe Layer Without Impurities and Study of Their Electrical Properties

The electrical and photoelectric properties of anisotype n-Si−p-GaSe heterojunctions obtained as a result of the deposition of a GaSe thin layer on a cold n-Si single crystal substrate by the thermal evaporation method were studied. It was determined that the height of the potential barrier in thermal annealing structures at T = 200 °C during t = 3 hours occurs due to the decrease in the density of states of local levels located near the Fermi level in the amorphous layer. The mechanism of photosensitivity in an isotype heterostructures was analyzed and it was found that the photosensitivity of the heterojunction increases as a result of a decrease in the surface density of state at the contact boundary of the components, by thermal means. The spectral distribution of the quantum efficiency in the n‑Si – p‑GaSe heterojunction was studied and their perspective was determined

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Statistical analysis of metal chelating activity of Centella asiatica and Erythroxylum cuneatum using response surface methodology

The purpose of the study is to evaluate the relationship between the extraction parameters and the metal chelating activity of Centella asiatica (CA) and Erythroxylum cuneatum (EC).The response surface methodology was used to optimize the extraction parameters of methanolic extract of CA and EC with respect to the metal chelating activity. For CA, Run 17 gave optimum chelating activity with IC50 = 0.93mg/mL at an extraction temperature of 25∘C, speed of agitation at 200 rpm, ratio of plant material to solvent at 1 g : 45mL and extraction time at 1.5 hour. As for EC, Run 13 with 60∘C, 200 rpm, 1 g : 35mL and 1 hour had metal chelating activity at IC50 = 0.3817mg/mL. Both optimized extracts were further partitioned using a solvent systemto evaluate the fraction responsible for the chelating activity of the plants.The hexane fraction of CA showed potential activity with chelating activity at IC50 = 0.090 and the ethyl acetate fraction of EC had IC50 = 0.120 mg/mL. The study showed that the response surface methodology helped to reduce the extraction time, temperature and agitation and subsequently improve the chelating activity of the plants in comparison to the conventional method

Использование арахисового масла в качестве присадки к дизельному топливу

As part of the environmental requirements for reducing the toxicity of exhaust gases of internal combustion engines, including diesel engines of tractor and combine harvesters, great attention is paid to various ways of reducing harmful substances in the exhaust gases combustion products. The problem of using energy-saving resources, including renewable energy, various types of alternative fuels is currently solved. In several ways these include using vegetable oils from various agricultural crops, one of which is peanut oil. Its use can help to solve two urgent problems: reducing the toxicity of exhaust gases of internal combustion engines. (Research objective) To analyze the properties of peanut oil as an additive to diesel fuel and evaluate the performance of a diesel engine using this type of fuel. (Materials and methods) The properties of peanut oil differ from those of diesel fuel by higher viscosity and lower heat value. To compensate for these shortcomings, kerosene has been added to the mixture of diesel fuel with peanut oil. In cold climatic conditions, the use of pure peanut oil is difficult, since its cloud point is 3.3 degrees Celsius, which is 20 degrees higher than that of diesel fuel. In the blend composition, the cloud point of the fuel decreases, which makes it possible to use it in colder conditions. (Results and discussion) The authors have conducted a study on the tractor engine D-120 coupled with a brake balancer installation without additional engine adjustments. As a result, they have obtained the characteristics of the engine working on fuel with the addition of peanut oil. The authors have compared the results of the engine operation on pure and mixed diesel fuel, revealed indicators of operating efficiency and toxicity of exhaust gases. (Conclusions) It has been proved experimentally that the addition of peanut oil to diesel fuel leads to a decrease in the specific effective fuel consumption, and also reduces the emission of soot and nitrogen oxides, while the engine power decreases slightly.Реферат. В рамках экологических требований к снижению токсичности отработанных газов двигателей внутреннего сгорания, в том числе тракторных и комбайновых дизелей, большое внимание уделяют различным способам снижения вредных веществ в продуктах сгорания топлива. Решается задача использования энергосберегающих ресурсов, в том числе возобновляемых источников энергии, различных альтернативных видов топлива. К ним относятся растительные масла сельскохозяйственных культур, в том числе арахисовое. (Цель исследования) Проанализировать свойства арахисового масла как добавки к дизельному топливу и оценить показатели работы дизеля на топливе с добавками арахисового масла. (Материалы и методы) Арахисовое масло отличается от дизельного топлива более высокой вязкостью и меньшей теплотой сгорания. В смесь дизельного топлива с арахисовым маслом добавляли керосин для компенсации этих недостатков. В холодных климатических условиях использование арахисового масла в чистом виде затруднено, так как для него температура помутнения составляет 3,3 градуса Цельсия, что на 20 градусов выше, чем у дизельного топлива. В смесевом составе температура помутнения топлива понижается, что позволяет использовать его в более холодных условиях. (Результаты и обсуждение) Провели исследование на тракторном двигателе Д-120 в паре с тормозной балансирной установкой без дополнительных регулировок двигателя. Получили характеристики двигателя при работе на топливе с добавкой арахисового масла. Сравнили результаты работы двигателя на чистом дизельном топливе и смесевом, выявили показатели эффективности работы и токсичности отработанных газов. (Выводы) Экспериментально доказали, что добавка арахисового масла к дизельному топливу сокращает удельный эффективный расход топлива, а также уменьшает выброс сажи и оксидов азота, при этом мощность двигателя снижается незначительно