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Vanadium redox flow batteries (VRFB) are a fertile energy storage technology especially for customized storage applications with special energy and power requirements. The dimensioning and control of these storages is mostly calculated beforehand using battery models in embedded simulation structures. To cover various stack designs, chemistries, application strategies and system architectures, battery simulation models should be validated with different experimental input data and thus show universal functionality. In this study the functionality of a grey box VRFB model using current, voltage and state of charge (SOC) of a 10 kW/100 kWh VRFB as input data are validated for an adapted input data set using of a 5 kW/10 kWh VRFB. This model is designed for stationary applications of VRFB only. The contribution of this study is (i) to apply a suitable SOC conversion method to the raw data from the used 5 kW VRFB system, (ii) to adapt the modeling code for broader use and integration of the SOC conversion, (iii) to validate the functionality and (iv) to investigate the influence of constant current and constant voltage phases in the raw data on the accuracy of the model. A comparison of experimental data between different redox flow batteries shows that most VRFB measure the open circuit voltage (OCV) to calculate the SOC of the battery. Using the calculated SOC as an input data the proposed simulation model need to be adapted and a method is applied to use OCV input data for model validation. Although simulation models in general often assume linearity between SOC and OCV, the study showed sufficient accuracy using polynomic fitting of second order. Applying a parametrization process the results of the simulation model are compared to the raw data and the scope of application of the grey box VRFB model is defined. While using the dominant constant current phase for the charging and discharging cycle, the grey box simulation model has been sufficiently parametrized and validated for adapted input data. [ABSTRACT FROM AUTHOR]

Carbon fiber composites are prohibitively expensive for a wide array of applications that would greatly benefit from their superior specific strength and specific stiffness. Replacing the market-dominant carbon fiber precursor material, polyacrylonitrile, with a low-cost alternative would significantly reduce the cost of carbon fiber production. Commodity polymers may provide such an alternative thanks to their abundance and ease of production into fibers. This review presents state-of-the-art carbon fiber production from polyacrylonitrile, an overview of melt-spinnable alternative precursors broadly, and an in-depth review of the latest advances in the synthesis of carbon fibers from low-cost, commodity thermoplastics such as polyethylene, polyamide, polystyrene, polyester, and poly(vinyl chloride). [Display omitted] [ABSTRACT FROM AUTHOR]

The authors of this article were guided by the desire to show the profitability of using renewable energy sources and to facilitate decisions for future investors as to their choice. The article classifies energy sources and methods for converting renewable energy sources (RES) and presents a technical comparison of two electricity supply systems: a photovoltaic system and a household wind farm for a selected building. A residential, single-family building, inhabited by a family of three, was adopted for analysis. Photovoltaics, the use of solar radiation energy to produce electricity, is classified next to wind farms as the most dynamically developing renewable energy technology. When analysing in terms of technology renewable conversion methods that provide us with electricity, the better installation is the photovoltaic installation. By analysing the cost of renewable energy conversion technologies that provide us with electricity, the photovoltaic system becomes more beneficial, because with a similar investment price we get a much shorter payback period than in the case of a backyard wind power station.

Common snow monitoring instruments based on hydrostatic pressure such as snow pillows are often influenced by various disturbing effects, which result in a reduced quality of the snow cover and snow water equivalent estimates. Such disturbing effects include energy transport into the snowpack, wind fields, and variations of snow properties within the snowpack (e.g., ice layers). Recently, it has been shown that Cosmic-Ray Neutron Probes (CRNP) are a promising technique to monitor snow pack development. CRNP can provide larger support and need lower maintenance compared to conventional sensors. These instruments are sensitive to the intensity of epithermal neutrons that are produced in the soil by cosmic radiation and are widely used to determine soil moisture in the upper decimeters of the ground. The application of CRNP for snow monitoring is based on the principle that snow water moderates the epithermal neutron intensity, which can be directly related to the snow water equivalent (SWE) of the snow pack. In this study, long-term CRNP measurements in the Pinios Hydrologic Observatory (PHO), Greece, were used to test different methods for converting neutron count rates to snow pack characteristics: (i) linear regression, (ii) standard N0-calibration function, (iii) a physically-based calibration approach, and (iv) thermal to epithermal neutron ratio. For this, a sonic sensor located near the CRNP was used to compare CRNP-derived snow pack dynamics with snow depth measurements. We found that the above-ground CRNP is well-suited for measurement of field scale SWE, which is in agreement with findings of other studies. The analysis of the accuracy of the four conversion methods showed that all methods were able to determine the mass of the snow pack during the snow events reasonably well. The N0-calibration function and the physically-based calibration function performed best and the thermal to epithermal neutron ratio performed worst. Furthermore, we found that SWE determination with above-ground CRNP can be affected by other influences (e.g., heavy rainfall). Nevertheless, CRNP-based SWE determination is a potential alternative to established method like snow depth-based SWE methods, as it provides SWE estimate for a much larger scales (12–18 ha).

Ignorance of the essence of regulations, as well as different approaches regarding the quantities and application of phosphates, their technological justification in food production, especially in meat products, which have led to problems between manufacturers, laboratories, inspection bodies, ministries and the incidence of possible technical barriers to trade, have motivated the Food Safety Agency of B and H (www.fsa.gov.ba), in addition to the already given interpretations, to speak again on this issue and, based on the quality of its scientific and technical opinion, give certain information and recommendations in the development of uniform risk assessment methodologies and thus contribute to the high level of protection of human life and health, and of the interests of consumers and producers. Food additives in Bosnia and Herzegovina are regulated by the current horizontal legislation, consisting of the set of four Books of additives and the part that refers to the use of phosphoric acid and phosphate by the Regulation of the use of food additives other than colors and sweeteners in foods ("Official Gazette", No. 83/08) (1). Standard ISO 13730 defines the spectral method for determination of total phosphorus in meat and meat products, the Annex V of the Rulebook on minced meat, semi-finished and meat products ("Official Gazette", No. 82/13) - vertical regulations are certain specific obligations and rules related only to the specific product, product group or production (2). This method is not selective for natural and added phosphors. To determine the amount of added phosphate to the meat, it is necessary to have a mathematical formula for calculating the amount of added phosphate (phosphoric acid, di-, tri- and polyphosphates) expressed as phosphorus pentoxide P2O5. [ABSTRACT FROM AUTHOR]

As a result of globalization, the world has become a unified market place which expedited international investments. This has created a need for information consumers to be able to analyze financial data via financial statements that are created within their own national currency. To satisfy this demand and be able to make correct decisions, financial statements that are created in foreign currencies need to be converted into national currency. There are various methods that are used for converting foreign currency financial statements into national currency financial statements. These methods are, current rate method, current-noncurrent method, monetary-nonmonetary method and temporal method. In this study, information about different conversion methods is provided and financial statements created using US Dollar ($) is converted into Turkish Liras (TL) via applications and is put forth the influences of conversion operations on financial analysis results. [ABSTRACT FROM AUTHOR]

The National Firearms Forensic Intelligence Database (NFFID © Crown Copyright 2003-2008) was developed by The Forensic Science Service (FSS) as an investigative tool for collating and comparing information from items submitted to the FSS to provide intelligence reports for the police and relevant government agencies. The purpose of these intelligence reports was to highlight current firearm and ammunition trends and their distribution within the country. This study reviews all the trends that have been highlighted by NFFID between September 2003 and September 2008. A total of 8887 guns of all types have been submitted to the FSS over the last 5 years, where an average of 21% of annual submissions are converted weapons. The makes, models, and modes of conversion of these weapons are described in detail. The number of trends identified by NFFID shows that this has been a valuable tool in the analysis of firearms-related crime. [ABSTRACT FROM AUTHOR]

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Abstract: Representing the appearances of surfaces illuminated from different directions has long been an active research topic. While many representation methods have been proposed, the relationships and conversion between different representations have been less well researched. These relationships are important, as they provide (a) an insight as to the different capabilities of the surface representations, and (b) a means by which they may be converted to common formats for computer graphic applications. In this paper, we introduce a single mathematical framework and use it to express three commonly used surface texture relighting representations: surface gradients (Gradient), Polynomial Texture Maps (PTM) and eigen base images (Eigen). The framework explicitly reveals the relations between the three methods, and from this we propose a set of conversion methods. We use 26 rough surface textures illuminated from 36 directions for our experiments and perform both quantitative and qualitative assessments to evaluate the conversion methods. The quantitative assessment uses a normalized root-mean-squared error as metric to compare the original images and those produced by proposed representation methods. The qualitative assessment is based on psychophysical experiments and non-parametric statistics. The results from the two assessments are consistent and show that the original Eigen representation produces the best performance. The second best performances are achieved by the original PTM representation and the conversion between Polynomial Texture Maps (PTM) and eigen base images (Eigen), while the performances of other representations are not significantly different. [Copyright &y& Elsevier]