DefibViz: A Visualization Tool for the Assessment of Electrode Parameters on Transthoracic Defibrillation Thresholds

DefibViz is a software application developed for defibrillation simulation and visualization. It exploits both surface techniques and methods for the interactive exploration of volumetric datasets for the analysis of transthoracic defibrillation simulation results. DefibViz has a graphical user interface for the specification of the shape, size, position, and applied voltage of a defibrillator's electrodes. An option is provided for using 3D slice plane widgets, which operate on the volumetric datasets, such that the distribution of the voltage gradient induced by an electric shock can be visually inspected in various tissues throughout the myocardium and torso. One goal of DefibViz is to enhance understanding of how electrode parameters relate to the change of the voltage gradient distribution throughout the heart, which may help lead to optimal defibrillator design. DefibViz is significant, in that, it is built by using an open-source graphics and visualization framework providing a platform for subsequent modifiability and extensibility. Moreover, it integrates simulation and visualization techniques, which previously required the running of several independent software executables, into an enhanced, seamless, and comprehensive software application.     

Assessment of passive autocatalytic recombiners' capabilities in case of Zr oxidation during station blackout scenario for TVSA and TVSM fuel assemblies of WWER 1000

This paper presents the investigation of Passive Autocatalytic Recombiners' (PARs) capabilities for hydrogen recombination in case of Station blackout scenario. The assessment was performed for both types of WWER fuel assemblies – the old Modernistic type of fuel assemblies (TVSM) and recently installed new Alternative type of fuel assemblies (TVSA) in Kozloduy NPP. The main difference between both types of fuel assemblies is the different geometries, masses of internals materials as well as different burnable poisons. To investigate the PARs' capabilities it has been performed comparison of fuel behaviour of both types of fuel assemblies.To perform this analysis it has been used MELCOR “input model” for Kozloduy Nuclear Power Plant (KNPP) WWER-1000. The model was developed at the Institute for Nuclear Research and Nuclear Energy (INRNE) for investigation of severe accident scenarios. The model provides a significant analytical capability for the Bulgarian technical specialists, working in the field of the NPP safety, for analysis of core and containment damaged states and the estimation of radionuclides' release outside fuel cladding.To assess the PARs' capabilities it was used the acceptance criterion for containment integrity to be 8% hydrogen concentration. This criterion was based on the decision of RSK (Germany commission for reactor safety).Generally, based on the performed analyses it was made a conclusion that using both types of fuel assemblies it was not disturbance of PARs' capabilities and safety criterion of NPP.     

Mn+Sb2O3 Thermite/Intermetallic Delay Compositions

The binary Mn+Sb₂O₃ pyrotechnic composition was investigated for mining detonator time delay applications. EKVI thermodynamic modelling predicted two maxima in the adiabatic reaction temperature. The local maximum, at a manganese fuel content of ca. 36 wt‐%, corresponds to a pure thermite‐type redox reaction: 3 Mn+Sb₂O₃→3 MnO+2Sb. The overall maximum in the adiabatic reaction temperature (ca. 1640 K), at the fuel‐rich composition of 49 wt‐% Mn, is consistent with the reaction 5 Mn+Sb₂O₃→3 MnO+2 MnSb, i.e. a combination of the standard thermite with an additional exothermic intermetallic reaction. XRD analysis of combustion residues confirmed the formation of MnSb and Mn₂Sb for fuel‐rich compositions. Burn rates were measured using delay elements assembled into commercial detonators. The d₅₀ particle sizes were 23.4 and 0.92 μm for the Mn fuel and Sb₂O₃ oxidant powders, respectively. The delay elements comprised rolled lead tubes with a length of 44 mm and an outer diameter of 6.4 mm. The rolling action compacted the pyrotechnic compositions to 74 ± 2 % theoretical maximum density. The burning rate increased linearly from 4.2 to 9.4 mm s⁻¹ over the composition range 25–50 wt‐% Mn.     

Naturally occurring phenolic compounds as promising antimycotoxin agents: Where are we now?

Mycotoxins are metabolites produced by molds that contaminate food commodities, are harmful to both humans and animals, as well as cause economic losses. Many countries have set regulatory limits and strict thresholds to control the level of mycotoxins in food and feedstuffs. New technologies and strategies have been developed to inhibit toxigenic fungal invasion and to decontaminate mycotoxins. However, many of these strategies do not sufficiently detoxify mycotoxins and leave residual toxic by-products. This review focuses on the use of phenolic compounds obtained from botanical extracts as promising bioagents to inhibit fungal growth and/or to limit mycotoxin yields. The mechanism of these botanicals, legislation concerning their use, and their safety are also discussed. In addition, recent strategies to overcome stability and solubility constraints of phenolic compounds to be used in food and feed stuffs are also mentioned.     

Severe accident management strategy verification for VVER-1000 (V320) reactor

Severe accident analysis of a reactor is an important aspect in evaluation of source term. This in turn helps in emergency planning and Severe Accident Management (SAM). The use of the Severe Accident Management Guideline (SAMG) is required for accident situation which is not handled adequately through the use of Emergency Operating Procedures (EOP), thus leading to a partial or a total core melt. Actions recommended in the SAMG aim at limiting the risk of radiologically significant radioactive releases in the short- and mid-term (a few hours to a few days). Initiation of SAMG for VVER-1000 is considered at two core exit temperatures viz. 650 °C as a desirable entry temperature and 980 °C as a backup action. Analyses have been carried out for VVER-1000 (V320) for verification of some of the strategies namely water injection in primary and secondary circuit. These strategies are analysed for a high and low pressure primary circuit transients. Station Black Out (SBO) is one such high pressure transient for which core heat can be removed by natural circulation of the primary circuit inventory by maintaining the secondary side inventory. This strategy has been verified where the feed water injection to secondary side of SG is considered from external power sources (e.g. mobile DG sets) as suggested in SAM guidelines. The second transient, a low pressure event is analysed for verification of the SG flooding and core flooding strategies. The analysis shows that SG flooding is not adequate to arrest the degradation of the core. In case of core flooding strategy, the analyses show that core flooding is not adequate to arrest the degradation of the core for the large break LOCA where as for small break LOCA the injections through available safety systems are adequate. The assessments are carried out with integral severe accident computer code ASTEC V1.3.     

Plastic Degradation by Extremophilic Bacteria

Intensive exploitation, poor recycling, low repeatable use, and unusual resistance of plastics to environmental and microbiological action result in accumulation of huge waste amounts in terrestrial and marine environments, causing enormous hazard for human and animal life. In the last decades, much scientific interest has been focused on plastic biodegradation. Due to the comparatively short evolutionary period of their appearance in nature, sufficiently effective enzymes for their biodegradation are not available. Plastics are designed for use in conditions typical for human activity, and their physicochemical properties roughly change at extreme environmental parameters like low temperatures, salt, or low or high pH that are typical for the life of extremophilic microorganisms and the activity of their enzymes. This review represents a first attempt to summarize the extraordinarily limited information on biodegradation of conventional synthetic plastics by thermophilic, alkaliphilic, halophilic, and psychrophilic bacteria in natural environments and laboratory conditions. Most of the available data was reported in the last several years and concerns moderate extremophiles. Two main questions are highlighted in it: which extremophilic bacteria and their enzymes are reported to be involved in the degradation of different synthetic plastics, and what could be the impact of extremophiles in future technologies for resolving of pollution problems.     

Synthesis, characterization and antimicrobial activity of conjugates based on fluoroquinolon-type antibiotics and gelatin

Different fluoroquinolon-type antibiotics were conjugated to gelatin with the aim to synthesize biomacromolecules with antimicrobial properties. The covalent linkage of the antibiotic was performed by a radical process involving the residues in the side chains of gelatin able to undergo oxidative modifications. The conjugation of antibiotic moieties onto the protein structure was confirmed by FT-IR, UV–Vis, fluorescence, and calorimetric analyses. Biocompatibility tests were performed on human bone marrow mesenchymal stromal cells and the antibacterial properties of bioactive polymers were investigated by appropriate tests against Klebsiella pneumoniae and Escherichia coli. With regard to the tests conducted in the presence of E. coli, a minimum inhibitory concentration (MIC) ranging from 0.05 to 0.40 μg mL^?1 was recorded, while in the presence of K. pneumoniae this concentration varies from 0.10 to 1.60 μg mL^?1. In all the conjugates, the drug moieties retain their biological activity and the MIC values are lower than the resistance parameters of fluoroquinolon-type antibiotics versus Enterobacteriacae. The collected data suggest a broad range of applications, from biomedical to pharmaceutical and food science for all conjugates.     

Security and Privacy Frameworks for Access Control Big Data Systems

In the security and privacy fields, Access Control (AC) systems are viewed as the fundamental aspects of networking security mechanisms. Enforcing AC becomes even more challenging when researchers and data analysts have to analyze complex and distributed Big Data (BD) processing cluster frameworks, which are adopted to manage yottabyte of unstructured sensitive data. For instance, Big Data systems’ privacy and security restrictions are most likely to failure due to the malformed AC policy configurations. Furthermore, BD systems were initially developed toped to take care of some of the DB issues to address BD challenges and many of these dealt with the “three Vs” (Velocity, Volume, and Variety) attributes, without planning security consideration, which are considered to be patch work. Some of the BD “three Vs” characteristics, such as distributed computing, fragment, redundant data and node-to node communication, each with its own security challenges, complicate even more the applicability of AC in BD.
This paper gives an overview of the latest security and privacy challenges in BD AC systems. Furthermore, it analyzes and compares some of the latest AC research frameworks to reduce privacy and security issues in distributed BD systems, which very few enforce AC in a cost-effective and in a timely manner. Moreover, this work discusses some of the future research methodologies and improvements for BD AC systems. This study is valuable asset for Artificial Intelligence (AI) researchers, DB developers and DB analysts who need the latest AC security and privacy research perspective before using and/or improving a current BD AC framework.     

Antiepileptic drug utilization in out-patients--a prescribing pattern study

Antiepileptic drug utilization for the treatment of different epileptic seizures had been investigated for 10 years in Bulgaria (1985-1994). The data were collected from ambulatory cards of 10,132 epileptic out-patients as well as from pharmacists' sales records. The results were expressed in DDD/1,000 inhabitants/year. During the period 1985-1989 the drug mostly prescribed had been phenobarbital both in mono- and polytherapy, but during the second period (1990-1994) it had been replaced to a high extent by carbamazepine and valproates. Polytherapy had given up its place to monotherapy in all forms of epileptic seizures during the 10-year period of investigation.