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Mathematical and numerical analyses have been performed to examine the close link between Fabry–Pérot resonance and natural-resonance frequencies. For the mathematical analysis, the conditions resulting in minimum magnitudes of reflection coefficients in frequency-domain are derived for air-backed and metal-backed low-loss non-dispersive (or weakly dispersive) dielectric samples with relative complex permittivity εr and thickness L for free-space wave propagation at normal incidence. The close relation between Fabry–Pérot resonance and natural-resonance frequencies is demonstrated for three di ...Более
This study presents the initial structural model of L-haloacid dehalogenase (DehLBHS1) from Bacillus megaterium BHS1, an alkalotolerant bacterium known for its ability to degrade halogenated environmental pollutants. The model provides insights into the structural features of DehLBHS1 and expands our understanding of the enzymatic mechanisms involved in the degradation of these hazardous pollutants. Key amino acid residues (Arg40, Phe59, Asn118, Asn176, and Trp178) in DehLBHS1 were identified to play critical roles in catalysis and molecular recognition of haloalkanoic acid, essential for effi ...Более
L-Cysteine is a semi-essential and proteinogenic amino acid, with the formula HO2CCH (NH2) CH2SH. L-cysteine is mostly found in protein-rich foods. In this study, catalysts consisting of cobalt (Co) supported on carbon nanotubes (CNTs) were prepared using the sodium borohydride (NaBH4) reduction method. These catalysts were characterized by means of energy-dispersive x-ray (EDX) with scanning electron microscopy (SEM), temperature-programmed reduction (TPR), and temperature-programmed oxidation (TPO) techniques. Characterization results confirmed the successful preparation of the desired catal ...Более
There are mounting concerns over the high concentrations of non-biogenic, toxic halogenated organic compounds being liberated into the ecosystem. Therefore, this study’s isolation of a novel bacterium from a contaminated stream in Fatsa, Ordu, Turkey, adept in degrading 2,2-dichloropropionic (of 2,2-DCP) is a welcome endeavor. The ability of the bacterial isolate to utilize 2,2-DCP as the sole carbon and energy source was discovered when the bacterium was observed to grow well on liquid minimal media containing 20 mM of 2,2-DCP, showing a doubling time of 14.2 h. The following genetic and bioc ...Более
Fertilizer recommendations for phosphorus (P) are generally based on the soil content of plant available P and the amount of P exported by the harvested crop. In countries of the former Soviet Union (SU), a widespread method is the Machigin extraction. The relationships between soil P contents extracted with this and other European methods are not well established. Here, we compare the Machigin soil P extraction method with the Calcium Ammonium Lactate P(CAL) procedure that is commonly used in Central Europe. Both methods were tested with 94 soil samples originating from Kyrgyzstan, Ukraine, a ...Более
In this paper we present the information security awareness rate of students in Kyrgyz Republic, where there is a rapid pace of formation and development of the information society. The survey was conducted with a sample of 172 students from different departments of the university. Our research study showed that despite the huge number of reports about computer crimes in the web, the knowledge about cybercrime is quite low and students are mostly not aware of many aspects of computer crime. Analysis was done to determine dependence of information security awareness rate on computer literacy ra ...Более
Plants can be used as biological indicators in assessing the damage done by bioaccumulation of heavy metals and their negative impact on the environment. In the present research, Roman nettle (Urtica pilulifera L.) was employed as a bioindicator for cadmium (Cd) pollution. The comparisons between unexposed and exposed plant samples revealed inhibition of the root growth (∼25.96% and ∼45.92% after treatment with 100 and 200 µmol/L Cd concentrations, respectively), reduction in the total soluble protein quantities (∼53.92% and ∼66.29% after treatment with 100 and 200 µmol/L Cd concentrations, re ...Более
The fields in which lead (Pb) finds application in the modern world have increased dramatically in recent years. As a consequence of this intensive utilization of Pb, its toxicity tends to pose more and more environmental problems. The aim of this study was to evaluate the genotoxic potential of Pb and to characterize some physiological parameters in Secale cereale under Pb stress. Plants were subjected to different exposure levels of Pb (0, 100, 200 and 400 µmol/L) for two weeks. At the end of the experimental period, the effects of Pb exposure on the photosynthetic pigments content (chloroph ...Более
Zeki SEVEROĞLU | İlhan DOĞAN | Gülbübü KURMANBEKOVA
Uncontrolled and unplanned urbanization and industrialization due to increase of population and rapid industrial development have created severe environmental problems in Kyrgyzstan during the last few decades. In this study, Juniperus virginiana, a dioecious species, was employed in order to make assessment of the heavy metal pollution rate in the area and of the heavy metal pollution impact on the mineral nutrient status of the plant. For this study, leaf (washed and unwashed) and bark samples of J. virginiana, and its co-located soil samples were collected from eight different stations, all ...Более
Benzo[c]cinnoline (BCC) molecules were electrochemically grafted onto a glassy carbon (GC) surface in nonaqueous media, and the modified surface was characterized using cyclic voltammetry (CV) with redox probes. Blockage of the electron transfer on the modified surface was observed using redox probes. Electrocatalytic effect of 2BCC modified GC (2BCC-GC) electrode surface towards to the electrochemical reduction of dioxygen was also investigated. A mechanistic scheme for the electrochemical catalysis was proposed. To clarify the mechanism of the dioxygen reduction, a less basic film of 2-benzo ...Более
Present work aims to create a benzoylglycine (BG)-modified glassy carbon (GC) substrate exploiting the electroreduction of diazonium salts. Dopamine was used to confirm the attachment of benzoylglycine molecules onto the glassy carbon surface by observing the blockage of the electron transfer using cyclic voltammetry (CV). BG-modified GC surface (BG-GC) was also characterized by Raman spectroscopy and electrochemical impedance spectroscopy (EIS) techniques. The ellipsometric thickness of the BG film was measured as approximately 14 nm for seven CV cycles. The electrocatalytic effect of BG-GC e ...Более
Wind speed is the most important parameter in the design and study of wind energy conversion systems. Probability density functions, such as the Weibull and Rayleigh, are often used in wind speed and wind energy analyses. In this study, statistical methods were used to analyze the wind speed data of Bishkek in the northern region of Kyrgyzstan. Measured daily time series of wind speed data were obtained from the State Meteorological Station in Bishkek, Kyrgyzstan, over a three-year period from 2003 to 2005. The probability density distributions are derived from the time series data and the dis ...Более