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Методы и средстваТеория и практика судебной экспертизы Том 17, № 4 (2022) 18 ВведениеОдной из основных задач геммологической экспертизы является определение природы ювелирных камней. Для решения данной задачи и распознавания их отличий от синтетических аналогов и имитаций применяются в основном традиционные методы минералогических исследований: многочисленные оптические методы, опре-деление твердости и плотности, рентгеновские методы, позволяющие определить элементный состав камней.Для исследования состава и свойств различных минералов в минералогии широко используется инфракрасная спектроскопия [1-3]. Минералы -это преимущественно твердые вещества, поэтому для регистрации их спектров применяют различные
Аннотация. Приведены экспериментальные данные о влиянии сахарного колера на УФ-спектр жидкостей, содержащих танины. Показано, что присутствие колера в спиртосодержащих жидкостях типа коньяков оказывает значительное влияние на величину оптической плотности при 280 нм, а следовательно, и на результаты количественн ого определения танинов в коньяках спектрофотометрическим методом. При исследовании соединений фенольной природы целесообразным представляется комплексный подход, включающий ряд методик: химическое тестирование на наличие танинов, регистрацию и анализ спектра в УФ-области, количественное определение дубильных веществ перманганатометрическим методом.
Tests of different oiling agents conducted at Kapron LLC allow recommending Limanol D65 spinning oiling agent and Convidol 207A finishing agent (Schill und Seilacher) for use in PA textile fibre technology to improve its processability. No alternatives to the traditionally used 22N spinning agent and N-02 finishing agent (Ivkhimprom OJSC) were found among domestic oiling agents.The complex, multistage process of manufacturing polyamide (PA) textile fibres [1] is characterized by a multitude of controllable and uncontrollable parameters which are often independent of each other. The quality and physicomechanical and textile-process properties of the finished fibre are determined to a great degree by the conditions of spinning, drawing, and textile-finishing treatment [2], including oiling of the fibre, where textile auxiliaries and oiling agents spinning and finishing are used.In the technology for manufacture of PA textile complex fibre at Kapron LLC (Engels), moistening and oiling of the fibre are combined during spinning on the spinning machine and because the oiling agent is washed off during finishing, it is applied again in winding the fibre on bobbin-winding machines.The composition of both the spinning and the finishing oiling agents can vary as a function of the requirements of the consumers of the fibres and due to the appearance of more efficient antistatic oiling agents and emulsifiers [3][4][5][6][7].Traditionally, oiling compositions have been mixtures of derivatives of fats, oils, and appropriate emulsifiers and wetting agents. The oiling composition should be almost neutral, should not corrode the equipment, and should be easily washed off the fibre. It should not permanently color the fibres, be oxidized on them, should not be toxic, and if possible, should not have an unpleasant odor. In addition, the following requirements are imposed on oiling compositions used in spinning fibres: adequate stability, which excludes separation during prolonged storage, and a high degree of dispersity which allows a thin elastic film, which is not destroyed during subsequent drawing, to form on the fibre. Thermal stability, necessary for manufacture of textured fibres is also important for the spinning oiling agent; when an oiling agent is heated in the air of industrial premises, toxic substances should not be liberated [3][4][5]. The oiling agents whose characteristics are reported in Table 1 are currently used in production of PA textile fibre.The basic functions of a spinning oiling agent are regulation of the friction coefficient, reduction of static charge, moistening of the fibre, increase in the coherence of the filaments, and providing for normal evolution of drawing and twisting. A domestic spinning oiling agent product 22N in the form of an aqueous emulsion containing (11-14)±1% preparatory agents (TU 6-14-246-76, manufactured by IvKhimprom OJSC) was used* at Kapron LLC. 22N is a composite of anion-active and nonionogenic emulsifiers and fatty acid salts in mineral oil, and the hydrogen index (pH) of a...
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