682 research outputs found

    Characteristics of Civil Defense Search and Rescue Units, Turkey, 2008-2009

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    Background Search and rescue (SAR) is a component of emergency and disaster response. SAR teams are limited in number; thus, collecting information on their characteristics may facilitate the establishment of mutual agreement protocols between countries. The objective of this study was to evaluate the characteristics of the Turkish Civil Defense SAR Units. Methods This descriptive study was conducted in 11 provinces of Turkey from July 2008 to October 2009. Interviews, observations and records were used to gather data, and descriptive statistics are presented. To evaluate the adequacy of personnel and equipment, a Likert-type scoring system was used (0-4 points). Results The size and population density of regions served by SAR Units varied. The mean duration of ground transportation from SAR Unit bases to the furthest provinces in their regions was 4.0±1.2 hours. The mean gathering and loading times were 70.5±42.3 and 48.6±18.0 minutes, respectively. The total employment ratio was 55.6%. The surface and underwater rescue section showed the highest functional sufficiency (3.3±0.7). The mean value for adequacy of SAR equipment was 2.6. Deficiencies were identified in periodic medical check-ups, preventive health measures and after-mission medical examinations for the personnel. Conclusion There is a need for standardization and improvement in various characteristics of SAR Units

    Bergmann-Thomson energy-momentum complex for solutions more general than the Kerr-Schild class

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    In a very well-known paper, Virbhadra's research group proved that the Weinberg, Papapetrou, Landau and Lifshitz, and Einstein energy-momentum complexes ``coincide'' for all metrics of Kerr-Schild class. A few years later, Virbhadra clarified that this ``coincidence'' in fact holds for metrics more general than the Kerr-Schild class. In the present paper, this study is extended for the Bergmann-Thomson complex and it is proved that this complex also ``coincides'' with those complexes for a more general than the Kerr-Schild class metric.Comment: RevTex, 12 page

    Teleparallel Energy-Momentum Distribution of Static Axially Symmetric Spacetimes

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    This paper is devoted to discuss the energy-momentum for static axially symmetric spacetimes in the framework of teleparallel theory of gravity. For this purpose, we use the teleparallel versions of Einstein, Landau-Lifshitz, Bergmann and Mo¨\ddot{o}ller prescriptions. A comparison of the results shows that the energy density is different but the momentum turns out to be constant in each prescription. This is exactly similar to the results available in literature using the framework of General Relativity. It is mentioned here that Mo¨\ddot{o}ller energy-momentum distribution is independent of the coupling constant λ\lambda. Finally, we calculate energy-momentum distribution for the Curzon metric, a special case of the above mentioned spacetime.Comment: 14 pages, accepted for publication in Mod. Phys. Lett.

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    The presence of organophosphorus compounds (OPs) in the environmental counterparts has become an important problem because of their toxicity. In this study, the photocatalytic degradation reactions of the three OPs with hydroxyl radical were investigated by both experimental and quantum chemical methods. Photocatalytic degradation kinetics of the examined organophosphorus compounds were investigated under UV-A irradiation using TiO2 as the photocatalyst. The effects of the initial concentrations on the degradation rate have been examined. There was an observable loss of OPs in the presence of TiO2 photocatalyst under UV-A at 0.2 g TiO2 per 100 mL. The quantum chemical calculations have been carried out by the density functional theory (DFT) at B3LYP/6-31g(d) level. The reaction pathways were modelled to find the most probable mechanism for OPs with the OH radical and to determine the primary intermediates. The rate constants of the eight reaction paths were calculated by the transition state theory. Conductor-like polarizable continuum model (CPCM) was used as the solvation model with the intention of understanding the water effect. The theoretical results were in agreement with experimental ones. © 2021 Serbian Chemical Society. All rights reserved.18,164Acknowledgement. The authors of this research has greatfully acknowledgemented to financially support of Tekirdag Namık Kemal University Research Project with the project number of NKUBAP.01.GA.18.164

    Severe Acute Respiratory Syndrome Type 2-Causing Coronavirus: Variants and Preventive Strategies

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    COVID-19 vaccines have constituted a substantial scientific leap in countering severe acute respiratory syndrome type 2-causing coronavirus (SARS-CoV-2), and worldwide implementation of vaccination programs has significantly contributed to the global pandemic effort by saving many lives. However, the continuous evolution of the SARS-CoV-2 viral genome has resulted in different variants with a diverse range of mutations, some with enhanced virulence compared with previous lineages. Such variants are still a great concern as they have the potential to reduce vaccine efficacy and increase the viral transmission rate. This review summarizes the significant variants of SARS-CoV-2 encountered to date (December 2021) and discusses a spectrum of possible preventive strategies, with an emphasis on physical and materials science

    Metal-based nanoparticles for combating antibiotic resistance

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    The resistance to antibiotics in combating bacteria is a serious worldwide problem. The search for new approaches to address antibacterial resistance is therefore of crucial importance and seeking alternatives for the treatment and control of bacterial diseases associated with resistant strains, which is in need of urgent action. There is an ongoing interest in metal-based nanoparticles (MBNPs) and their usage synergy with antibiotics due to their unique properties, such as overcoming bacterial resistance, reducing acute toxicity compared to their sizes, and allowing dosage reduction of active pharmaceutical ingredients. Combining MBNPs and antibiotics not only enhances the antibacterial effect but also allows the inhibition of biofilm production. Furthermore, MBNPs and antibiotics incorporated in polymeric biomaterial matrix have been widely studied to improve their efficiency and devoid the resistance. However, these studies need to be combined in a literature review. Polymeric biomaterials offer high mechanical stability with improved biocompatibility. Moreover, their use makes a single dose of administration of the final product with extended antibiotic half-life possible while slowly releasing their reservoir, which is an advantage in continuously combating resistance. This review focuses on different promising biomedical strategies for enhancing the bactericidal efficacy of antibiotics by the synergistic use of MBNPs, antibiotics, and polymeric biomaterials together to combat the resistance of different bacterial strains. In addition, it is prospected to guide opportunities for new research for future biomedical applications

    An improved lumped element nonlinear circuit model for a circular CMUT cell

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    Cataloged from PDF version of article.This paper describes a correction and an extension in the previously published large signal equivalent circuit model for a circular capacitive micromachined ultrasonic transducer (CMUT) cell. The force model is rederived so that the energy and power is preserved in the equivalent circuit model. The model is able to predict the entire behavior of CMUT until the membrane touches the substrate. Many intrinsic properties of the CMUT cell, such as the collapse condition, collapse voltage, the voltage-displacement interrelation and the force equilibrium before and after collapse voltage in the presence of external static force, are obtained as a direct consequence of the model. The small signal equivalent circuit for any bias condition is obtained from the large signal model. The model can be implemented in circuit simulation tools and model predictions are in excellent agreement with finite element method simulations. © 2012 IEEE

    Bivariate sea-ice assimilation for global-ocean analysis–reanalysis

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    In the last decade, various satellite missions have been monitoring the status of the cryosphere and its evolution. Besides sea-ice concentration data, available since the 1980s, sea-ice thickness retrievals are now ready to be used in global operational prediction and global reanalysis systems. Nevertheless, while univariate algorithms are commonly used to constrain sea-ice area or volume, multivariate approaches have not yet been employed due to the highly non-Gaussian distribution of sea-ice variables together with the low accuracy of thickness observations. This study extends a 3DVar system, called OceanVar, which is routinely employed in the production of global/regional operational/reanalysis products, to process sea-ice variables. The tangent/adjoint versions of an anamorphosis operator are used to locally transform the sea-ice anomalies into Gaussian control variables and back, minimizing in the latter space. The benefit achieved by such a transformation is described. Several sensitivity experiments are carried out using a suite of diverse datasets. The sole assimilation of the CryoSat-2 provides a good spatial representation of thickness distribution but still overestimates the total volume that requires the inclusion of Soil Moisture and Ocean Salinity (SMOS) mission data to converge towards the observation estimates. The intermittent availability of thickness data can lead to potential jumps in the evolution of the volume and requires a dedicated tuning. The use of the merged L4 product CS2SMOS shows the best skill score when validated against independent measurements during the melting season when satellite data are not available. This new sea-ice module is meant to simplify the future coupling with ocean variables
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