12 research outputs found
ИЗМЕРЕНИЕ ХАРАКТЕРИСТИК ВОЗДУХА В ВЕРХНЕЙ ЗОНЕ ПОМЕЩЕНИЯ ПРИ ГОРЕНИИ БУМАЖНОЙ ПРОДУКЦИИ
Experimental studies of the dynamics of temperature, transmittance coefficient and forward scatter of radiation in the smoke under the ceiling space when burning paper where conducted. Behavior of main signs of fire at an early stage, common for the mentioned type of inflammables, was studied.Проведены экспериментальные исследования динамики температуры, коэффициента пропускания и рассеивания вперед излучения дымом под потолком помещения при горении бумажной продукции. Изучено поведение основных признаков пожара на ранней стадии, характерное для данного типа пожарной нагрузки.
КОНСТРУКЦИЯ И АЛГОРИТМ РАБОТЫ ЛАЗЕРНОГО КОМБИНИРОВАННОГО ПОЖАРНОГО ИЗВЕЩАТЕЛЯ
The point optical smoke detector is currently the most effective means of fire detection at the early stage of its occurrence. The urgent task for this type of detector is to increase its sensitivity to «black» smoke and ensure resilience to the effects of electromagnetic interference and particle smoke origin.The objective of this work is to develop a structure and algorithm of point combined fire detector that provides high sensitivity to various types of fumes, detection rate and high noise immunity. The decision of the current objective is carried out using the proposed optical scheme of the dual-channel devices of smoke detection (for control of the radiation intensities scattered by smoke particles and passed through the smoke).The design and algorithm of the combined fire detector comprising a dual-channel laser device of smoke detection and carbon monoxide detector is developed.The results of the made detector tests indicate about its increased in comparison with the conventional single-channel point smoke fire detector sensitivity to various types of fumes and detection rate of fires. The high functional characteristics of the detector are provided with application additional channel of smoke detection (to intensity change of transmitted radiation through it) created by the requirements for unrestricted entry of smoke in the area of control and effective algorithm for processing of recorded signals. Точечный оптический дымовой пожарный извещатель остается в настоящее время наиболее эффективным средством обнаружения пожара на ранней стадии его появления. Актуальной задачей для данного типа извещателя является повышение его чувствительности к «черным» дымам и обеспечение устойчивости к воздействию электромагнитных помех и частиц не дымового происхождения. Целью настоящей работы являлась разработка конструкции и алгоритма работы точечного комбинированного пожарного извещателя, обеспечивающего высокую чувствительность к различным типам дымов, скорость их обнаружения и высокую помехоустойчивость.Решение поставленной цели осуществлено использованием предложенной оптической схемы двухканального устройства обнаружения дыма (по контролю интенсивностей излучения, рассеянного частицами дыма и прошедшего через дым).Разработана конструкция и алгоритм работы комбинированного пожарного извещателя, включающего двухканальное лазерное устройство обнаружения дыма и датчик угарного газа.Результаты тестовых испытаний изготовленного извещателя свидетельствуют о его повышенной в сравнении с обычным одноканальным точечным дымовым пожарным извещателем чувствительности к различным типам дымов и скорости обнаружения возгораний. Высокие функциональные характеристики извещателя обеспечиваются применением дополнительного канала обнаружения дыма (по изменению интенсивности проходящего через него излучения), созданными условиями беспрепятственного захода дыма в зону контроля и эффективным алгоритмом обработки регистрируемых сигналов.
Epoxidation of Fatty Acid Methyl Esters with Hydrogen Peroxide Catalyzed by Peroxopolyoxotungstate PW4 Encapsulated in the MIL-100(Cr) Framework
The MIL-100(Cr), PW12@MIL-100(Cr) and PW4@MIL-100(Cr) catalysts were prepared and characterized through XRD, FTIR, BET, SEM, EDS and Raman spectroscopy. A comparison of the catalytic properties of the synthesized materials in the epoxidation of FAMEs with hydrogen peroxide was made. The PW4@MIL-100(Cr) catalyst exhibited the highest catalytic activity and provided a high selectivity for the formation of epoxides. The effects of the reaction temperature, catalyst loading, reaction time and FAME:hydrogen peroxide molar ratio on the reaction performance were investigated, and the optimal process conditions were determined. An epoxide yield of 73% with a selectivity of 77% could be obtained using PW4@MIL-100(Cr) after 4 h at 40 °C. The catalytic stability test showed that PW4@MIL-100(Cr) could be easily separated and reused without any treatment for at least five consecutive cycles without a loss of activity or selectivity
MEASUREMENT OF AIR CHARACTERISTICS IN THE UPPER ZONE OF THE ROOM WITH BURNING PAPER
Experimental studies of the dynamics of temperature, transmittance coefficient and forward scatter of radiation in the smoke under the ceiling space when burning paper where conducted. Behavior of main signs of fire at an early stage, common for the mentioned type of inflammables, was studied
Catalytic Conversion of Glycerol to Lactic Acid Over Cu-Based Catalysts
Copper (I, II) oxide powders were tested for glycerol conversion to lactic acid under alkaline conditions. Fresh and spent catalysts were characterized using powder X-ray diffraction, Scanning Electron Microscopy/Energy Dispersive X-ray Spectroscopy, the BET-nitrogen adsorption method and FTIR spectroscopy. In all cases, an almost complete in situ reduction of Cu (I, II) oxides into metallic Cu was observed, even after one catalytic run. Moreover, all the samples of spent catalysts showed similar catalytic activity regardless of their initial form and particle size. Commercial copper powders, prepared copper powders and in situ reduced copper catalysts were tested under the same conditions to compare their catalytic activity. It was shown that the in situ reduced copper catalyst had similar activity to the specially prepared copper powders and much higher activity compared to the commercial copper powders. The in situ reduced copper catalyst exhibited rather high stability. The glycerol conversion and lactic acid selectivity were about 98% and 70%, respectively, after ten catalytic cycles
Mechanism Analysis and Kinetic Modelling of Cu NPs Catalysed Glycerol Conversion into Lactic Acid
Mechanism analysis and kinetic modeling of glycerol conversion into lactic acid in the alkaline media with and without heterogeneous catalyst Cu NPs are reported. The reaction pathways were determined in agreement with the experimental results and comprise several types of reactions, namely dehydrogenation, hydrogenolysis, dehydration and C–C cleavage. Experimental concentration-time profiles were obtained in a slurry batch reactor at different glycerol, NaOH and Cu NPs concentrations in a temperature range of 483–518 K. Power law, Langmuir–Hinshelwood (LH) and Eley–Rideal (ER) models were chosen to fit the experimental data. The proposed reaction pathways and obtained kinetic model adequately describe the experimental data. The reaction over Cu NPs catalyst in the presence of NaOH proceeds with a significantly lower activation barrier (Ea = 81.4 kJ∙mol−1) compared with the only homogeneous catalytic conversion (Ea = 104.0 kJ∙mol−1). The activation energy for glycerol hydrogenolysis into 1,2-propanediol on the catalyst surface without adding hydrogen is estimated of 102.0 kJ∙mol−1. The model parameters obtained in this study would be used to scale an industrial unit in a reactor modeling
СONSTRUCTION AND THE ALGORITHM OPERATION OF THE LASER COMBINED FIRE DETECTOR
The point optical smoke detector is currently the most effective means of fire detection at the early stage of its occurrence. The urgent task for this type of detector is to increase its sensitivity to «black» smoke and ensure resilience to the effects of electromagnetic interference and particle smoke origin.The objective of this work is to develop a structure and algorithm of point combined fire detector that provides high sensitivity to various types of fumes, detection rate and high noise immunity. The decision of the current objective is carried out using the proposed optical scheme of the dual-channel devices of smoke detection (for control of the radiation intensities scattered by smoke particles and passed through the smoke).The design and algorithm of the combined fire detector comprising a dual-channel laser device of smoke detection and carbon monoxide detector is developed.The results of the made detector tests indicate about its increased in comparison with the conventional single-channel point smoke fire detector sensitivity to various types of fumes and detection rate of fires. The high functional characteristics of the detector are provided with application additional channel of smoke detection (to intensity change of transmitted radiation through it) created by the requirements for unrestricted entry of smoke in the area of control and effective algorithm for processing of recorded signals
Interference immunity fire alarm system on the basis of a laser fiber optic smoke detector
Приведено описание конструкции лазерного оптоволоконного дымового извещателя, обеспечивающего повышенную устойчивость к воздействию электромагнитных полей систем пожарной сигнализации, использующих его в качестве средства обнаружения пожара. Обнаружение дыма данным извещателем осуществляется по уменьшению регистрируемой приемником излучения интенсивности светового потока вследствие частичного поглощения и рассеянии его на частицах дыма. Высокая помехоустойчивость системы пожарной сигнализации на базе лазерного оптоволоконного извещателя, обусловлена отсутствием подводимых к извещателю от прибора приемо-контрольных длинных электропроводных линий питания и связи, играющих роль эффективных приемных антенн случайных электромагнитных полей. Изложены результаты апробации работоспособности предложенной конструкции извещателя, свидетельствующие о его высокой чувствительности обнаружения возгорания. The work describes the construction of a laser fiber-optic smoke detector that has enhanced immunity to electromagnetic fields of a fire alarm system, by using it as a mean of fire detection. The assessment of smoke concentration in this detector is conducted by reduction of the registered luminous flux radiation due to its partial absorption and scattering on the smoke particles. High interference immunity of fire alarm systems based on the use of a laser fiber-optic detector is conditioned by the absence of long power supply lines and connection with the control device that are used as effective receiving aerials of random electromagnetic fields. The results are presented on the tests for efficiency of the proposed construction of the detector proving its high sensitivity of fire detection
SPECIFIC CHELATE-LIKE CATALYSIS IN AMIDATION REACTION OF FATTY ACID METHYL ESTERS
Specific chelate-like pre-reaction complexes were detected in amidation reaction of fatty acid methyl esters and dimethylaminopropylamine catalyzed by aminoalcohols.Работа выполнена при финансовой поддержке Российского Научного Фонда (проект №19-73-00276)