483 research outputs found
GEOTHERMAL ENERGY OF THE REPUBLIC OF SRPSKA AND HYDROCHEMICAL ASPECTS OF ITS EXPLORATION AND EXPLOITATION
One of the most used renewable energy sources worldwide is geothermal energy. It represents the heat, originated by natural processes happen in the Earth interior. The hot springs phenomena are the most frequent natural manifestation of geothermal activity. Geothermal potentiality of some area can be estimated based on geothermal gradient. Geothermal gradient is a conductive terrestrial parameter that represents the degree of increasing of the Earth temperature vs. depth. It is usually expressed in ⁰C/m or ⁰C/km. Different areas have different thermal gradients and thus different geothermal potential. Generally, higher geothermal gradients correspond to areas containing more geothermal energy. Geothermal characteristics of the territory of the Republic of Srpska are closely related to its complex geological setting. It is the reason why geothermal characteristics are different from area to area. Higher geothermal potentiality is recognised in the northern parts of the entity, in the first order in Semberija, Posavina and Banja Luka regions. The use of geothermal energy with different fluid temperatures can be considered throughthe Lindal diagram, who firstly proposed acomprehensive scale with appropriate temperatures for different uses. High temperature fluids are mostly used for electricity production and moderate and low temperature fluids for the direct use.Despite the fact that the territory of the Republic of Srpska has favourable geothermal properties, utilization of this kind of renewable energy resource is inadequate. Especially indicative are data about the use of geothermal energy by heat pumps (in bad sense) in comparison with praxis of developed countries. Chemical composition of thermal waters plays very important role and can be used in its exploration stage, for analyses of possibility of its use and for prediction of exploitation effects, as well. This kind of renewable energyresource, highly ecologically recommended, must be considered more seriously in the future in the Republic of Srpska. Furthermore, it must be put into the energy strategic documentsin appropriate manner
Establishment and initial characterization of SOX2-overexpressing NT2/D1 cell clones
SOX2, a universal marker of pluripotent stem cells, is a transcription factor that helps control embryonic development in vertebrates; its expression persists in neural stem/progenitor cells into adulthood. Considering the critical role of the SOX2 transcription factor in the regulation of genes required for self-renewal and pluripotency of stem cells, we developed and characterized SOX2-overexpressing NT2/D1 cell clones. Using Southern blot and semi-quantitative RT-PCR, we confirmed integration and expression of exogenous SOX2 in three NT2/D1 cell clones. Overexpression of the SOX2 gene was detected in two of these clones. SOX2 overexpression in NT2/D1 cell clones resulted in altered expression of key pluripotency genes OCT4 and NANOG. Furthermore, SOX2-overexpressing NT2/D1 cell clones entered into retinoic acid-dependent neural differentiation, even when there was elevated SOX2 expression. After 21 days of induction by retinoic acid, expression of neural markers (neuroD1 and synaptophysin) was higher in induced cell clones than in induced parental cells. The cell clone with SOX2 overexpression had an approximately 1.3-fold higher growth rate compared to parental cells. SOX2 overexpression did not increase the population of cells undergoing apoptosis. Taken together, we developed two SOX2-overexpressing cell clones, with constitutive SOX2 expression after three weeks of retinoic acid treatment. SOX2 overexpression resulted in altered expression of pluripotency-related genes, increased proliferation, and altered expression of neural markers after three weeks of retinoic acid treatment
Simple point-ion electrostatic model explains the cation distribution in spinel oxides
The A2BO4 spinel oxides are distinguished by having either a normal (N) or an inverse (I) distribution of the A, B cations on their sublattices. A point-ion electrostatic model parametrized by the oxygen displacement parameter u and by the relative cation valencies ZA vs ZB provides a simple rule for the structural preference for N or I: if ZA>ZB the structure is normal for u>0.2592 and inverse for u0.2578. This rule is illustrated for the known spinel oxides, proving to be ∼98% successful. © 2010 The American Physical Society
PCR amplification and sequence analysis of the rat Sox3 gene
Sox3 gen je jedan od markera najranijih faza razvića nervnog sistema kičmenjaka koji je uključen u kontrolu diferencijacije nervnih prekursora. Uprkos činjenici da je genom pacova sekvenciran i javno dostupan, samo parcijalna sekvenca Sox3 gena ove vrste je bila deponovana u bazi podataka. U ovom radu smo primenom PCR-a, sekvenciranja i bioinformatičke analize generisali kompletnu kodirajuću sekvencu Sox3 gena pacova. Analiza dobijene sekvence je pokazala da Sox3 gen kodira protein od 449 amino kiselina. Uporedna analiza ortologih SOX3 proteina pacova i čoveka pokazala je visok stepen evolutivne očuvanosti. Identifikacija i karakterizacija Sox3 gena pacova doprineće boljem razumevanju njegove uloge tokom razvića nervnog sistema i omogućiće bolji uvid u evoluciju ovog gena kod vertebrata.The Sox3 gene is considered to be one of the earliest neural markers in vertebrates, playing a role in specifying neuronal fate. Despite the completion of a rat genome sequencing project, only a partial sequence of the rat Sox3 gene has been available in the public database. Using PCR, sequencing, and bioinformatics tools, in this study we have determined the complete coding sequence of the rat Sox3 gene encoding 449 amino acids. Comparative analysis of rat and human SOX3 proteins revealed a high degree of conservation. Identification of the rat Sox3 gene sequence would help in understanding the biological roles of this gene and provide insight into evolutionary relationships with vertebrate orthologs
Određivanje preostalog životnog veka i strategije zamene malouljnih prekidača na osnovu dinamičke analize rizika: doktorske disertacije
The main goal of this dissertation is to estimate the remaining useful
life of minimum oil circuit breakers (CB) based on data collected
during their regular inspection.
Using the proposed approach, CB’s with the highest risk can be
identified, whose failure can cause the greatest economic
consequences, but also consequences for the stability of the power
system. By determining the reliability and risk of minimum oil CB’s,
it is possible to see what influence has the place of installation on the
aging process. In this way, a correlation is established between the
values of voltage drops and other categories such as: feeder type,
voltage level, year of production, number of disconnected short-circuit
currents.
The end result of the CB’s analysis is the possibility of knowing its
aging process, classification of the state of all CB’s based on the risk
of failure, knowledge of the impact of CB’s replacement on the
availability of the power station, without additional investment in new
equipment or labor
Multiphysics simulation of corona discharge induced ionic wind
Ionic wind devices or electrostatic fluid accelerators are becoming of
increasing interest as tools for thermal management, in particular for
semiconductor devices. In this work, we present a numerical model for
predicting the performance of such devices, whose main benefit is the ability
to accurately predict the amount of charge injected at the corona electrode.
Our multiphysics numerical model consists of a highly nonlinear strongly
coupled set of PDEs including the Navier-Stokes equations for fluid flow,
Poisson's equation for electrostatic potential, charge continuity and heat
transfer equations. To solve this system we employ a staggered solution
algorithm that generalizes Gummel's algorithm for charge transport in
semiconductors. Predictions of our simulations are validated by comparison with
experimental measurements and are shown to closely match. Finally, our
simulation tool is used to estimate the effectiveness of the design of an
electrohydrodynamic cooling apparatus for power electronics applications.Comment: 24 pages, 17 figure
1-Ferrocenyl-3-(4-methylanilino)propan-1-one
In the title ferrocene derivative, [Fe(C5H5)(C15H16NO)], the dihedral angle between the best planes of the benzene and the substituted cyclopentadienyl ring is 83.4 (1)°. The presence of a methyl substituent in the para position of the aniline group does not alter the crystal packing compared to that of 3-anilino-1-ferrocenylpropan-1-one [Leka et al. (2012 ▶). Acta Cryst. E68, m229]. The molecules are connected into centrosymmetric dimers via N—H⋯O hydrogen bonds. In addition, C—H⋯O and C—H⋯N contacts stabilize the crystal packing
Anti-toxocara antibodies in patients with suspected visceral larva migrans and evaluation of environmental risk of human infection in Belgrade, Serbia
Toxocariasis is a frequent zoonotic parasitosis in Serbia. The aim of the study was to examine anti-Toxocara IgG antibodies in serum and cerebrospinal fluid (CSF) in patients with suspected visceral larva migrans (VLM) in Belgrade, and to estimate the prevalence of T. canis eggs in dog fecal deposits collected in green public areas. A total of 145 patients were examined by ELISA. In 26.39% (38/144) of serum samples, T canis IgG were detected, and in 6 CSF samples, 2 were positive for antibodies. Seropositivity was detected in 26.1% (34/130) adults and 33.3% (5/15) children. A total number of 155 fresh dog feces were collected in five public parks in Belgrade where T canis eggs were identified with a prevalence of 33.55% (52/155). Based on the high prevalence of parasite eggs, we estimated a high risk of human infection by T canis eggs in public green areas in Belgrade
Members of the CREB/ATF and AP1 family of transcription factors are involved in the regulation of SOX18 gene expression
The SOX18 transcription factor plays an important role in endothelial cell specification, angiogenesis and atherogenesis. By profiling transcription factor interactions (TranSignal TM TF Protein Array) we identified several transcription factors implicated in angiogenesis that have the ability to bind to the SOX18 optimal promoter region in vitro. In this report we focused our attention on distinct transcription factors identified by the array as belonging to AP-1 and CREB/ATF protein families. In particular, we analyzed the effects of CREB, JunB, c-Jun and ATF3 on SOX18 gene expression. Functional analysis revealed that CREB acts as a repressor, while JunB, c-Jun and ATF3 act as activators of SOX18 promoter activity. Our findings indicate that a transcriptional network that includes CREB, JunB, c-Jun and ATF3 could be involved in angiogenesis-related transcriptional regulation of the SOX18 gene
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