Importance of thermoanalytical methods for quality control in the car building industry

Mechanical and dynamic methods of thermal analysis are most advantageous for quality control of inorganic and organic materials which are used in car building industry.     

Industrial standardization of thermal analysis in Japan

To satisfy the needs for industrial standards for thermal analysis in the Japanese polymer industry, round-robin tests of differential scanning calorimetry (DSC), thermogravimetry (TG), thermomechanical analysis (TMA) and thermodilatometry (TD) have been carried out recently. The results are discussed in this short review. The DSC applications tested were not only for determination of transition temperature but also for measurements of the transition heat and heat capacity. The TG task group did not aim at longterm thermal endurance studies, but relative thermal stability in molding and estimation of filler content, residual solvent content, etc. TMA was found to be a useful tool for measuring softening temperature and heat distortion temperature, especially for high-temperature engineering plastics, instead of the Vicat test which has temperature limitations. For temperature calibration of DSC and TG, ICTA-NIST certified reference materials were used together with other potential temperature standards; some inorganic substances and alloys were not found to be preferable to pure metals. For TMA and TD metal plates were found to be very useful for temperature calibration. Analysis of the round-robin test results also clarified present status of practical applications of thermal analysis, such as reproducibility and causes of errors. Plenary lecture     

Evaluation of the thermal stability of biodiesel blends of castor oil and passion fruit

The diversity of raw materials and technological routes employed in the biodiesel production has resulted in products with different chemical properties. This non-uniformity in the biodiesel composition may influence to the fuel quality. The aim of this study was to evaluate biodiesel blends of passion fruit and castor oil in different proportions and their thermal stability. Biodiesel blends of passion fruit and castor oil presented parameters in the standards of the Petroleum, Natural Gas and Biofuels National Agency. The TG curves indicated that castor oil biodiesel was more stable. Passion fruit biodiesel has a high content of oleic and linoleic acids, which are more susceptible to oxidation. Biodiesel blend of passion fruit and castor oil 1:1 increased the thermal stability in relation to passion fruit biodiesel. Biodiesel blend of passion fruit and castor oil 1:2 presented higher thermal stability, because castor oil has a high content of ricinoleic acid.     

Thermal standards from the laboratory of the government chemist

The Laboratory of the Government Chemist (LGC) is a focal point for the production, analysis and certification of reference materials. Within the field of thermal analysis the LGC is concerned with the development of purity standards and materials certified for enthalpy of fusion and melting point. For some time the LGC has been concerned with the significant differences in purity data which can be produced by the different manufactures' differential scanning calorimeters. This paper will highlight the initiatives the LGC is undertaking in overcoming this uncertainty in purity measurements through the use of certified thermal standards.     

离子色谱在我国建材行业中的应用进展

对国内建材行业相关标准中涉及的离子检测方法进行总结;概述了离子色谱在建材中常见的氯离子、硫酸根、氟离子检测中的应用进展,并对其在建材行业中的应用前景进行了展望。离子色谱法具有快速,选择性好,灵敏度高等优点,在建材行业中会得到越来越广泛的应用。     

广州蓄能水电厂2012年度水环境质量与评价

通过对广州蓄能水电厂库区水质及渗水进行监测,评价水库水质现状、富营养化水平、对混凝土的腐蚀性及渗水对水工建筑物的腐蚀作用。2012年3月及9月两次采集库区及渗水共54个样品,按照国标或行业标准进行检测,并对污染物含量进行分析。评价结果表明,电厂水库水质良好,各测点所测项目均符合《地表水环境质量标准》（GB3838-2002）Ⅲ类水标准;根据天然水化学特征评定上、下库各测点均属低矿化度的极软水;根据水库理化指标评价,水库水体整体营养水平属中营养状态,未出现富营养化现象;根据碳酸盐类含量评定,水库水对水工建筑混凝土具有弱-中腐蚀性;渗水中p H、总碱度、碳酸根含量较水库水中含量高,说明施工支洞及其它厂房坝体建筑受到一定程度侵蚀。本次监测评价为广州蓄能水电厂的水资源保护和进一步开展水资源利用提供参考,同时为广州蓄能水电厂下一年度监测方案调整提供依据。     

Online monitoring of thermoset post-curing by dynamic mechanical thermal analysis DMTA

Thermosetting moulding compounds are synthetic materials which can be easily formed in the molten state and achieve high temperature stability due to a cross-linking process which takes place during manufacture. To ensure thermal and mechanical properties, post-curing of moulded phenolic resin components is necessary for high quality applications. In the industrial practice, post-curing time–temperature-programs are heuristically acquired. In this paper, dynamical mechanical thermal analysis is employed to determine optimal post-curing conditions for injection moulded parts from phenolic resin.     

Determination of the pseudocomponents and kinetic analysis of selected combustible solid wastes pyrolysis based on Weibull model

The application of thermal analysis to meat products, like all materials, is governed by energy transfer, from which invaluable information on thermodynamics of processes is obtained. Various meat systems have been analyzed with different success ratios. Proteins in meat formed the key area of interest due to their effect on product quality, shelf life, functionality and also their ability to interact with other components. Initially success rates were low owing to lack of sensitivity, results with complex curves, complications in interpretation and a large number of factors affecting the biological system. Later with developments in instrumentation and computer models for better resolution and reproducibility, wider horizons could be covered with easy solutions to complex results. Though thermal analysis has been used exhaustively in meat, research in this area has become stagnant and new areas are being left untouched. This review emphasizes the importance of thermal analysis in the meat industry and also the need to use more advanced equipment for better understanding of the biological changes occurring in muscle during processing and storage.     

Research on Hazardous Waste Removal Management: Identification of the Hazardous Characteristics of Fluid Catalytic Cracking Spent Catalysts

Fluid catalytic cracking (FCC) spent catalysts are the most common catalysts produced by the petroleum refining industry in China. The National Hazardous Waste List (2016 edition) lists FCC spent catalysts as hazardous waste, but this listing is very controversial in the petroleum refining industry. This study collects samples of waste catalysts from seven domestic catalytic cracking units without antimony-based passivation agents and identifies their hazardous characteristics. FCC spent catalysts do not have the characteristics of flammability, corrosiveness, reactivity, or infectivity. Based on our analysis of the components and production process of the FCC spent catalysts, we focused on the hazardous characteristic of toxicity. Our results show that the leaching toxicity of the heavy metal pollutants nickel, copper, lead, and zinc in the FCC spent catalyst samples did not exceed the hazardous waste identification standards. Assuming that the standards for antimony and vanadium leachate are 100 times higher than that of the surface water and groundwater environmental quality standards, the leaching concentration of antimony and vanadium in the FCC spent catalyst of the G set of installations exceeds the standard, which may affect the environmental quality of surface water or groundwater. The quantities of toxic substances in all spent FCC catalysts, except those from G2, does not exceed the standard. The acute toxicity of FCC spent catalysts in all installations does not exceed the standard. Therefore, we exclude “waste catalysts from catalytic cracking units without antimony-based passivating agent passivation nickel agent” from the “National Hazardous Waste List.”     

Thermal characterization of mica–epoxy composite used as insulation material for high voltage machines

The study of mica–epoxy-based composite has a great role in high voltage machines industry. Beside electric properties, this composite should present compatible mechanical and chemical, in this case thermal characteristics to insulate properly the conductor strand, avoiding short-circuits, and leading electrical current with minimal losses. Improvement of the quality is possible through the knowledge of raw materials and system. This study aims to list a complete thermal characterization of mica composite, its components, epoxy resin, anhydride methylhexahydrophtalic, mica tape and zinc naphthenate, and thermoanalytical interactions between them. These data shows intrinsic properties of the system, which is so relevant to its great electrical and thermal performance. Thermal analysis allows the detailed study of curing process and thermal decomposition, predicting and suggesting mechanisms, beside future and possible optimization to the system. Composite system glass transition (T _g) was obtained through an important and very respected methodology, presenting the value of T _g = 138 ± 2 °C, finally characterizing the material.     

Finite element analysis of heat transfer in transformers from high voltage stations

This present paper presents the modeling and simulation of the thermal transfer in the transformers from the high electric voltage stations using finite element method. As the transformers are of high power and are inversed in oil, a particular interest represents the maintenance of physical and chemical parameters of oil as long a time during operation. For this, one presents the coupled analysis electromagnetic field and thermal field. The procedure of coupled analysis consists of a quantity of heat release when passing electric current through the coil of transformers. The amount of heat affects the chemical properties of the oil. Because overloads occurring in their operation, the chemical properties of the oils worsen in time and may lead to premature aging and scrapping of them. The simulation is based on the creating of a geometrical model which follows the transformer’s sizes and material properties, real constants are established by standards. After the simulations an optimal solution is obtained regarding the correct usage of the transformers.     

Synthesis of a complex additive based on stearyl methacrylate and vinyl acetate for environmentally clean diesel fuel

An additive based on stearyl methacrylate–vinyl acetate copolymer was synthesized by the method of controlled atom transfer radical polymerization. The additive simultaneously improves the low-temperature properties of hydrotreated diesel fuels and enhances their resistance to thermal oxidation to meet the European quality standards. Comparative analysis of the effect exerted on the characteristics of environmentally clean diesel fuel by the synthesized additive and Dodiflow commercial depressor additive was made, and the negative effect of the latter on the thermo oxidative stability of diesel fuel was revealed of the fuel to thermal oxidation was revealed.     

Thermal characterisation of Australian oil shales

There has been a significant research effort on the development of an oil industry based on Australian oil shales. However, to date the research has been based mainly on the processing aspects of oil shale. The thermal analyses of oil shales, while having been the subject of many studies, have been limited to some extent by instrumentation and analytical techniques. This paper reports on thermal analysis studies utilising traditional thermogravimetry/differential thermal analysis (TG/DTA) and differential scanning calorimetry (DSC). The application of modern thermal analysis techniques such as high resolution TG (HRTG) and modulated differential scanning calorimetry (MDSC) is also examined and compared to the traditional methods.     

中药质量控制技术发展展望

本文从中药产业需求、现代化需求、技术需求、机遇与挑战等方面概括了中药质量控制技术发展的背景;讨论了中药质量控制技术对于提高中药药效和安全性、推动产业发展和推进中药国际化的意义;综述了中药质量控制技术的现状,分析了在过程控制、安全性控制、标准品和对照品制备、指纹图谱技术等方面的不足;提出了中药质量控制技术应重点发展以分离和表征技术为主的中药质量控制关键技术、中药安全性控制技术、中药质量控制标准体系、中药质量控制原创性技术和中药标准品、对照品生产技术,制定技术标准,建立具有中药特色的过程控制和产品质量控制标准。     

A new approach to DSC calibration in wax/polymer blending

DSC analysis of wax/polymer blends is carried out between 270 and 420 K. Calibration for melting point and enthalpy is normally carried out using indium (melting point 430 K), which is unsatisfactory for these materials. IUPAC organic standards covering this range tend to sublime and their onset temperatures are variable. Pure alkanes have similar thermal characteristics to wax/polymer blends and some have been well characterised by adiabatic calorimetry. They are being investigated as alternative secondary calibration standards to give more accurate thermal characterisation of wax/polymer blends. Also,n-triacontane can be used to check DSC resolution.     

Thermal characterization of dried extract of medicinal plant by DSC and analytical techniques

The increased search for herbal products has generated an increasing interest in improving the quality control of dried extracts by pharmaceutical industry since these are raw materials of great importance by their quality and versatility. This work aimed at the application of various analytical techniques (thermal analysis, X-ray diffraction, scanning electron microscopy, and infrared Fourier transform spectroscopy) in the characterization of dried extracts of two plants from the Brazilian semiarid region with medicinal properties. The DSC curves for the dried extracts of Ximenia americana L. and Schinopsis brasiliensis Engl. showed that thermal processes occur between 33.50 and 118.58 °C and between 39.17 and 126.14 °C. The X-ray powder diffraction revealed high degree of amorphization, but the dried extract of X. americana L. showed some diffraction peaks of high intensity. The IR spectra showed high variety of metabolites in the extracts dried. Through this study it was possible to verify the feasibility of applying these techniques in the characterization of raw materials from medicinal plants for use in the herbal medicines production.     

铁矿石、锰矿石和铬矿石取样和样品制备技术概况

我国钢铁工业的主要原料铁矿石、锰矿石和铬矿石进口量大,对外依存度分别在80%,55%,95%以上,贸易中经常发生质量纠纷,有些质量纠纷的焦点为取样和样品制备技术。从影响样品代表性的角度概述了铁矿石(包括直接还原铁和热压块)、锰矿石和铬矿石取样和样品制备所涉及的方法标准、品质波动、样品部位、最小份样数、最小份样量、缩分方法、最小留样量和设备的技术要求,分析了取样和样品制备中存在的问题,提出了确保取样和样品制备人员能正确执行方法标准、采取有代表性样品应采取的措施。     

Application of thermal analysis to the cement industry

Methods involving heat measurements have been applied in the cement industry for a long time. Differential thermal analysis (DTA) is used to explain the clinkering reactions, but it is a dynamic method which thus does not allow measurements and calculations of the thermal balance of the reactions to be made. In contrast, high temperature microcalorimetry may be used to measure the enthalpy of the clinkering reactions of industrial raw materials. Results obtained by using this technique allow us to determine the thermal profile of clinkering reactions in the kiln and to quantify the heat exchange in the solid material during its burning.Low temperature conduction microcalorimetry gives information on the hydration mechanism of the cement pastes. In this paper, we review the applications of thermal analysis in the cement industry paying special attention to new methods such as high temperature microcalorimetry.

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Zusammenfassung Seit langer Zeit werden in der Zementindustrie Verfahren mit Wärmemessung angewendet. Zur Erforschung der Verschlackungsreaktionen wird DTA verwendet, was jedoch ein dynamisches Verfahren ist und keine Messungen und Berechnungen bezüglich des thermischen Gleichgewichtes erlaubt. Im Gegensatz dazu kann Hochtemperatur-Mikrokalorimetrie zur Messung der Enthalpie von Verschlackungsreaktionen industrieller Rohstoffe dienen. Mit Hilfe der durch diese Methode erlangten Resultate kann das thermische Profil von Verschlackungsreaktionen im Kiln und der Wärmeaustausch im Festmaterial beim Brennen bestimmt werden.Niedertemperatur-Konduktions-Mikrokalorimetrie liefert Informationen über den Hydratationsmechanismus von Zementleim. Unter spezieller Beachtung neuer Methoden, wie z.B. der Hochtemperatur-Mikrokalorimetrie, wird in diesem Artikel ein Überblick über die Anwendungen der Thermoanalyse in der Zementindustrie gegeben.

     

Corrosion of stainless steel in food and pharmaceutical industry

Stainless steels are widely used in the food and pharmaceutical industry because of their high corrosion resistance and superior mechanical properties. These features are crucial because produced foodstuffs and drugs must comply with high purity and quality standards. Just a proper selection of stainless steel grade can prevent corrosion phenomena that can be detrimental to the whole manufacturing process. Food/drugs production process phases will be here analyzed and discussed with a particular emphasis on the possible corrosion mechanism of stainless steels in those particular operating conditions. Recent advances on the methods to assess corrosion of stainless steels in food and pharmaceutical industries will be disclosed.