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Validation of a method for ethanol analysis in biological and non-biological samples and its toxicological application 生物和非生物样品中乙醇分析方法的验证及其毒理学应用
Pub Date : 2021-07-12 DOI: 10.2298/hemind201201016k
E. Kostić, M. Vujović, B. Milosavljevic
A simple, cost-effective and fast headspace gas chromatography method coupled with flame ionization detection (HS-GC/FID) for determination of ethanol was developed and validated for clinical and forensic toxicology purposes. HS-GC/FID is often used for alcohol determination in different biological and non-biological samples. The calibration dependence of the method was linear in the range from 0.15 to 4.00 g dm-3 (r2=0.999) with adequate accuracy (99?106 %) and precision. The limit of detection (LOD) was 0.006 g dm-3. The method was quantitative (LOQ) above 0.020 g dm-3. The new method was successfully used for determination of ethanol in biological samples of intoxicated patients, car accidents participants, participants in criminal acts, and postmortem samples, non-biological samples such as alcoholic beverages, alcohol-based herbal preparations, cosmetic preparations, etc. This method is easy to perform, making it suitable not only for the routine applications in clinical biochemistry and forensic laboratories, but also in different fields of industry (e.g. for pharmaceutical preparations, cosmetics, dietary supplements, etc.). Some of the applications for ethanol determination in different samples related to various clinical-forensic cases are presented.
建立了一种简单、经济、快速的顶空气相色谱-火焰电离检测(HS-GC/FID)测定乙醇的方法,并对其进行了验证,用于临床和法医毒理学目的。HS-GC/FID常用于不同生物和非生物样品的酒精含量测定。该方法在0.15 ~ 4.00 g dm-3范围内呈线性关系(r2=0.999),准确度为99?106%)和精度。检测限(LOD)为0.006 g dm-3。该方法定量限在0.020 g dm-3以上。该方法可成功地用于醉酒病人、车祸参与者、犯罪行为参与者、尸体样品、非生物样品(如酒精饮料、酒精类中草药制剂、化妆品制剂等)中乙醇的测定。该方法操作简单,不仅适用于临床生物化学和法医实验室的常规应用,而且适用于不同的工业领域(如药物制剂、化妆品、膳食补充剂等)。一些应用乙醇测定在不同的样品相关的各种临床法医案件提出。
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引用次数: 0
Glazing effect for producing environmentally friendly ceramics for cladding applications 用于生产包覆应用的环保陶瓷的玻璃效果
Pub Date : 2021-07-12 DOI: 10.2298/hemind210112017p
A. E. Pavlycheva, S. E. Pikalov, G. Selivanov
This paper presents results of comparative studies of environmental safety of ceramic materials, based on a low-plasticity clay with the introduction of galvanic sludge, boric acid and titanium dioxide in 3 different combinations. The experimental samples were manufactured under 15 MPa pressing pressure and at the maximum firing temperature of 1050 oC. Prior to the toxicological experiments, diurnal extracts of the materials into the model neutral and acidic media were obtained. The toxicological safety was determined by using the Daphnia mortality method, and by comparing the maximum permissible concentrations of heavy metals for drinking and household water with the heavy metals? concentrations in diurnal extracts. The presented data show that the combined introduction of all the investigated additives results in the glazing effect of ceramic particles surfaces so that an environmentally safe material can be produced that exhibits sufficiently high-performance properties. The use of low-plastic clay and electroplating sludge expands the raw material base for producing ceramics and allows the disposal of environmentally hazardous compounds of heavy metals contained in electroplating sludge. Ceramic materials based on the developed charge composition can be used for producing items for external cladding for buildings and structures.
本文介绍了以低塑性粘土为研究对象,引入电污泥、硼酸和二氧化钛三种不同组合对陶瓷材料环境安全性的比较研究结果。实验样品在15 MPa的压力下,在1050℃的最高烧成温度下制备。在毒理学实验之前,将这些材料的日提取物放入模型中性和酸性介质中。毒理学安全性采用水蚤死亡率法,并通过比较饮用水和家庭用水中重金属的最大允许浓度与重金属?日萃取物的浓度。所提供的数据表明,所有所研究的添加剂的组合引入导致陶瓷颗粒表面的上釉效果,从而可以生产出具有足够高性能的环保材料。低塑性粘土和电镀污泥的使用扩大了生产陶瓷的原料基础,并允许处理电镀污泥中含有的对环境有害的重金属化合物。基于所开发的电荷组合物的陶瓷材料可用于生产建筑物和结构的外部包层物品。
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引用次数: 0
Microbial bioremediation of heavy metals 重金属的微生物修复
Pub Date : 2021-04-16 DOI: 10.2298/HEMIND200915010V
Ana Volarić, Z. Svirčev, Dragana Tamindžija, D. Radnović
Heavy metal pollution is one of the most serious environmental problems, due to metal ions persistence, bioavailability, and toxicity. There are many conventional physical and chemical techniques traditionally used for environmental clean-up. Due to several drawbacks regarding these methods, the use of living organisms, or bioremediation, is becoming more prevalent. Biotechnological application of microorganisms is already successfully implemented and is in constant development, with many microbial strains successfully removing heavy metals. This paper provides an overview of the main heavy metal characteristics and describes the interactions with microorganisms. Key heavy metal resistance mechanisms in microorganisms are described, as well as the main principles and types of heavy metal bioremediation methods, with details on successful pilot scale bioreactor studies. Special attention should be given to indigenous bacteria isolated from the polluted environments since such species are already adapted to contamination and possess resistance mechanisms. Utilization of bacterial biofilms or consortia could be advantageous due to higher resistance and a combination of several metabolic pathways, and thus, the possibility to remove several heavy metals simultaneously. Novel technologies covered in this review, such as nanotechnology, genetic engineering, and metagenomics, are being introduced to the field of bioremediation in order to improve the process. To conclude, bioremediation is a potentially powerful solution for cleaning the environment.
由于重金属离子的持久性、生物利用度和毒性,重金属污染是最严重的环境问题之一。有许多传统的物理和化学技术传统上用于环境清理。由于这些方法的一些缺点,使用活生物体,或生物修复,正变得越来越普遍。微生物的生物技术应用已经成功实施,并在不断发展,许多微生物菌株成功地去除重金属。本文综述了重金属的主要特征,并描述了与微生物的相互作用。介绍了微生物对重金属的主要抗性机制,以及重金属生物修复方法的主要原理和类型,并详细介绍了成功的中试规模生物反应器研究。应特别注意从污染环境中分离出来的本地细菌,因为这些物种已经适应污染并具有抗性机制。利用细菌生物膜或细菌联合体可能是有利的,因为它们具有更高的抗性和几种代谢途径的结合,因此有可能同时去除几种重金属。本综述所涉及的新技术,如纳米技术、基因工程和宏基因组学,正在被引入生物修复领域,以改进这一过程。综上所述,生物修复是清洁环境的一个潜在的强有力的解决方案。
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引用次数: 2
Control of the size and compositional distributions in a milling process by using a reverse breakage matrix approach 用反向破碎矩阵法控制铣削过程中尺寸和成分的分布
Pub Date : 2021-03-02 DOI: 10.2298/HEMIND201027004B
Nemanja Bojanić, Aleksandar Fišteš, T. Došenović, A. Takaci, M. Brdar, K. Yoneda, D. Rakic
A method based on the reverse breakage matrix approach is proposed for controlling the effects that milling has on the particle size distribution and composition of the comminuted material. Applicability, possibilities, and limitations of the proposed method are tested on examples related to the process of wheat flour milling. It has been shown that the reverse matrix approach can be successfully used for defining the particle size distribution of the input material leading to the desired, predetermined particle size and compositional distribution in the output material. Moreover, we have illustrated that it is possible to simultaneously control both, input and output particle size distribution, together with the composition of the output material.
提出了一种基于反向破碎矩阵的方法来控制磨矿对粉碎物料粒度分布和组成的影响。通过与小麦粉制粉过程有关的实例,对所提出方法的适用性、可能性和局限性进行了测试。结果表明,逆矩阵法可以成功地用于确定输入材料的粒度分布,从而得到所需的、预定的输出材料的粒度和成分分布。此外,我们已经说明,可以同时控制两者,输入和输出粒度分布,以及输出材料的组成。
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引用次数: 0
Effects of water pretreatment on properties of pellets made from beech particles 水预处理对山毛榉颗粒制粒性能的影响
Pub Date : 2021-03-02 DOI: 10.2298/HEMIN191224007P
J. Popović, M. Popović, Milanka Djiporović-Momčilović, Ana Prahin, V. Dodevski, Ivana Gavrilović-Grmuša
Particles of beech wood were treated with hot water at the temperature of 150 oC, during 60 min, prior to the pelleting process. The applied hot water pretreatment affected the chemical composition and heating value of particles. Two groups of pellets, designated as PT 10 and PT 20, were produced from treated beech particles, with the moisture content of particles being 10.5 and 20.5 %, respectively. Pellets from nontreated beech particles (PNT) served as controls to assess the hot water pretreatment effects on the pellet properties. Both, the applied pretreatment, and the particle moisture content, affected properties of the obtained pellets. The heating value of PT 10 ad PT 20 pellets has increased for ~6 and 1 %, respectively. The mineral (ash) content in treated pellets decreased for about 24 % in comparison to that in PNT pellets. In addition, the bulk (apparent) density of pellets has increased for 21 % (PT 10) and 10 % (PT 20), as a consequence of the hot water pretreatment of particles. The specific density of PT 10 pellets was for 16 % higher, while the equilibrium moisture content (after conditioning at RH 68 % and 20.1?C) was for about 32 % lower in comparison to the respective properties of PNT pellets.
山毛榉木颗粒在150℃的温度下,在60分钟内用热水处理,然后进行造粒过程。应用热水预处理影响了颗粒的化学成分和热值。以处理过的山毛榉颗粒为原料,制备了两组颗粒,分别为PT 10和PT 20,颗粒含水量分别为10.5%和20.5%。以未经处理的山毛榉颗粒(PNT)为对照,评价热水预处理对颗粒性能的影响。所应用的预处理和颗粒含水量都影响所获得的球团的性能。PT 10和PT 20球团的热值分别提高了6%和1%。与PNT颗粒相比,处理过的颗粒中的矿物(灰分)含量降低了约24%。此外,由于颗粒的热水预处理,颗粒的体积(表观)密度增加了21% (PT 10)和10% (PT 20)。与PNT球团的性能相比,PT 10球团的比密度提高了16%,而平衡水分含量(在相对湿度为68%和20.1℃后)降低了约32%。
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引用次数: 2
Miscanthus x giganteus as a building material - lightweight concrete 作为建筑材料的芒草——轻质混凝土
Pub Date : 2021-01-01 DOI: 10.2298/HEMIND201116013S
Ivana Zoran Šekler, Sunčica Vještica, V. Jankovic, S. Stefanović, V. Ristić
A perennial plant Miscanthus x giganteus has found its habitat and multiple applications in Europe, despite the fact that it originates from Asia. This study presents the potential use of this plant in new lightweight concrete materials so-called bio-concretes. The above-ground part of the plant was harvested, dried, crushed, and mixed with binders in different proportions. After casting and drying, the samples were characterized physical and mechanical properties. The results have shown that the sample with a higher content of binders while smaller miscanthus granulation and casted in molds under higher pressure exhibited the highest values of the compressive strength and density. In specific, the density was in the order of magnitude of that reported for other types of lightweight concrete with organic fillers, such as sawdust-based concrete ("Durisol"), which further justifies the use of miscanthus for these purposes.
一种多年生植物芒草(Miscanthus x giganteus)在欧洲找到了它的栖息地和多种用途,尽管它起源于亚洲。这项研究展示了这种植物在新型轻质混凝土材料——生物混凝土中的潜在用途。植物的地上部分被收获,干燥,粉碎,并与不同比例的粘合剂混合。在浇注和干燥后,对样品的物理力学性能进行了表征。结果表明,黏结剂含量高、芒粒量小、浇铸压力高的样品抗压强度和密度最高。具体而言,密度与其他类型的轻质混凝土报告的有机填料,如木屑基混凝土(“Durisol”)的数量级相当,这进一步证明了将芒草用于这些目的是合理的。
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引用次数: 0
Hydrodynamics and mass transfer in Kühni extraction columns k<s:1> hni萃取柱的流体力学与传质
Pub Date : 2021-01-01 DOI: 10.2298/HEMIND201204014S
M. Sovilj, Momčilo Đ. Spasojević
This work provides a review of hydrodynamic characteristics and mass transfer in the K?hni extraction columns. The experiments, as reported in the literature, were performed in the presence and absence of mass transfer. The results showed that the Sauter mean drop diameter was strongly affected by the rotor speed and interfacial tension, whereas the effects of the dispersed and continuous velocities were negligible. Empirical correlations for the Sauter mean drop diameter, taken from the literature, were discussed. It was experimentally determined that the dispersed-phase holdup depended to a great extent on the rotor speed, mass transfer direction between the phases, physical characteristics of fluids in the liquid-liquid system, and the dispersed-phase flowrate whereas it increased with the increase in mixing in the two-phase system and the ratio of phase flowrates. On the other hand, it has been shown that the mass transfer rate increases with increasing the level of back mixing. It was found that the mass transfer coefficient depends on the rotor speed and the direction of mass transfer between the phases. At the same time, it has been shown that the mass transfer coefficient depends relatively little on the phase flowrates. An empirical correlation was proposed for prediction of the overall mass transfer coefficient based on dimensionless numbers. Also, novel empirical correlations for prediction of the Sherwood number in the continuous phase were presented based on the dispersed-phase holdup, Reynolds number, and mass transfer direction between the phases. Empirical correlations based on dimensionless numbers can be considered as a useful tool for the design of the K?hni columns.
本文综述了K?Hni萃取柱。实验,如文献报道的,是在存在和不存在传质的情况下进行的。结果表明:转子转速和界面张力对索特平均液滴直径的影响较大,而分散速度和连续速度对索特平均液滴直径的影响可以忽略;讨论了从文献中得到的索特平均液滴直径的经验相关性。实验结果表明,分散相含率在很大程度上取决于转子转速、两相传质方向、液-液体系中流体的物理特性和分散相流量,而随着两相体系混合量的增加和相流比的增大而增大。另一方面,传质速率随反混程度的增加而增加。结果表明,传质系数与转子转速和两相传质方向有关。同时,研究表明,传质系数对相流量的依赖相对较小。提出了一种基于无因次数的总传质系数的经验关联预测方法。此外,基于弥散相含率、雷诺数和相间传质方向,提出了预测连续相中舍伍德数的新经验关联。基于无因次数的经验相关性可以被认为是设计K?hni列。
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引用次数: 0
Extraction of ammonium nickel sulfate hexahydrate by hydrometallurgical process from the hyperaccumulating plant Odontarrhena muralis – case study from Serbia 湿法冶金法从超富集植物蛇尾草中提取六水硫酸镍铵-以塞尔维亚为例
Pub Date : 2021-01-01 DOI: 10.2298/hemind210701027m
B. Marković, Dragan M. Randjelovic, G. Jovanović, G. Tomović, K. Jakovljević, Tomica Mišljenović, M. Sokić
Phytomining is a new promising technique that is based on using hyperaccumulating plants which biomass is utilized as a bio-ore for metal extraction. The Ni-hyperaccumulating species Odontarrhena muralis is widely distributed on ultramafic soils in Serbia, and could be a promising candidate for Ni agromining. In the present study, efficiency of a hydrometallurgical process for Ni recovery using biomass of O. muralis wild population through the synthesis of Ni salts from plant ash in the form of ammonium nickel sulfate hexahydrate, Ni(NH4)2(SO4)2 6H2O ? (ANSH) was assessed. The average Ni content in the plant from ultramafic sites in West Serbia was up to 3.300 g kg-1. The mass yield of ANSH crystals from the crude ash was ~12 % with the average purity of 73 % were obtained. By optimizing the purification process before precipitation of ANSH crystals, it is possible to obtain salt crystals of higher purity, which increases the economic profitability of this process. The results of this preliminary study on wild population of O. muralis show the increased potential for implementation of phytomining practices as an alternative way of Ni extraction on ultramafic sites in Serbia.
植物采矿是一种极具发展前景的新技术,它是以超富集植物为基础,利用生物质作为生物矿石进行金属提取。在塞尔维亚超镁质土壤中广泛分布有镍超富集物种,是一个很有前途的镍农业开采候选物种。在本研究中,通过从植物灰中合成六水硫酸镍铵、Ni(NH4)2(SO4)2 6H2O ?(ANSH)进行评估。在塞尔维亚西部的ultramafic站点中,平均镍含量高达3.300 g kg-1。从粗灰分中得到的ANSH晶体的质量收率为~ 12%,平均纯度为73%。通过优化ANSH结晶沉淀前的提纯工艺,可以获得更高纯度的盐结晶,提高了该工艺的经济效益。本初步研究结果表明,在塞尔维亚的超镁铁遗址上,采用植物提取方法作为镍提取的一种替代方法具有更大的潜力。
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引用次数: 1
Influence of the ringer's solution on wear of vacuum mixed poly(methyl methacrylate) bone cement in reciprocating sliding contact with AISI 316l stainless steel 林格氏溶液对真空混合聚甲基丙烯酸甲酯骨水泥与AISI 316l不锈钢往复滑动接触磨损的影响
Pub Date : 2021-01-01 DOI: 10.2298/HEMIND210105011Z
F. Živić, N. Grujovic, S. Mitrovic, J. Tanaskovic, P. Todorovic
This paper presents microstructural properties and damage behaviour of a vacuum mixed poly(methyl metacrylate) (PMMA) bone cement, during the sliding contact with AISI 316L stainless steel, under micro-loads. Influence of the Ringer's solution on the wear was analysed in comparison to dry contact. The variation of load did not produce any significant change of the wear factor while the increase in the sliding speed induced significant increases in the wear factor, more pronounced in the case of dry sliding. The obtained wear factors were in average higher for the sliding in Ringer's solution than those obtained under dry conditions. Significant fragmentation of the worn tracks, of irregular shapes with broken edges, was observed, slightly more pronounced for the dry contact. Many cavities and voids were formed on the wear track surface, but they did not extend into the bulk material. Higher loads produced more uniform and less fragmented wear tracks. Abrasive, adhesive wear and plastic deformation grooves were observed, as well as fatigue and erosive wear. Fatigue cracks developed in the direction normal to sliding. Network of fine craze cracks was exhibited on the surface of wear tracks, especially pronounced in the case of dry sliding. These results are important since they contribute to understanding the sites of crack initiation, and development mechanisms on the surface of PMMA bone cements, also including synergistic effects of physiological environments pertaining to the non-steady crack and craze behaviour and crack pattern development in PMMA.
本文研究了真空混合聚甲基丙烯酸甲酯(PMMA)骨水泥在微载荷作用下与AISI 316L不锈钢滑动接触时的微观结构性能和损伤行为。与干接触相比,分析了林格氏溶液对磨损的影响。载荷的变化对磨损系数没有显著影响,而滑动速度的增加会引起磨损系数的显著增加,在干滑动情况下更为明显。在林格氏溶液中获得的滑动磨损系数平均高于在干燥条件下获得的磨损系数。观察到磨损的痕迹明显破碎,形状不规则,边缘断裂,干接触稍微明显一些。在磨损轨迹表面形成了许多空腔和空洞,但它们没有延伸到大块材料中。更高的载荷产生更均匀和更少碎片化的磨损轨迹。观察到磨粒磨损、粘着磨损和塑性变形槽,以及疲劳和侵蚀磨损。疲劳裂纹沿与滑动方向垂直发展。磨损轨迹表面呈现网状细裂纹,干滑时更为明显。这些结果非常重要,因为它们有助于理解PMMA骨水泥表面裂缝的起裂位置和发展机制,也包括PMMA非稳态裂缝和开裂行为以及裂缝模式发展的生理环境的协同效应。
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引用次数: 0
Optimization of the active component grinding process and hydrophobization of the obtained powder fire extinguisher 优化有效组分研磨工艺及所得粉末灭火器的疏水性
Pub Date : 2021-01-01 DOI: 10.2298/HEMIND210114012M
Slavica Mihajlović, N. Djordjevic, M. Jovanović, M. Vlahović, Ljubinko Savić, A. Patarić, M. Blagojev
This work presents a grinding process of monoammonium phosphate (MAP) as an active component in a powder fire extinguisher (PFE). The aim was to determine the grinding time for reaching the optimal particle size of MAP necessary for permanent fire extinguishing. MAP grinding was performed by using a laboratory ceramic ball mill and a vibrating cup mill. The grinding process was controlled by sieving using a 100 ?m sieve at precisely defined time intervals. The efficiency of a PFE depends on the share of the -100 ?m fraction of the active component, which has to exceed 60 %. The optimal grain size with 64 % of fraction of particle size -100 ?m was obtained after 33 min of grinding of ?3000 ?m mm grain size MAP by using a ball mill (single-stage grinding). In two-stage process, by grinding the same initial MAP sample (?3000 ?m) in the vibro mill for 10 min, powder with the upper limit grain size of 300 ?m and the mean grain diameter of 120 ?m was obtained. This sample with a reduced size was further ground in the ceramic ball mill yielding 67.5 % of the fraction of particle size -100 ?m after 19 min. The total time of the two-stage grinding process was 29 min. By analyzing the grinding time of MAP required to get the lowest required share of the fraction of particle size -100 ?m that provides the effectiveness of formed PFE it can be concluded that 64 % of this fraction was obtained after 33 min of single-stage grinding, while only after 26 min in the two-stage process. Thus, the grinding time was reduced by 7 min indicating certain energy savings. Stability and hydrophobicity of the obtained PFE were achieved by coating with magnesium stearate (MgSt) at the content of 2 % in a ball mill for 15 min. The coating was confirmed by the standardized procedure for verification of PFE hydrophobic properties in contact with water drops. To obtained PFE had component mass ratios of MAP:AS:CC:QS:MgSt=55:20:18:5:2 (AS-ammonium sulfate; CC-calcium carbonate, QS-quartz sand) and was further characterized by chemical and granulometric analyses. The fire extinguishing efficiency of the PFE was tested in controlled conditions, whereby fires were initiated by burning solid materials and flammable liquids. In both cases, immediate elimination of flames was achieved, thus proving the efficiency of the PFE obtained in this work for practical applications.
本文介绍了一种磷酸一铵(MAP)作为粉末灭火器(PFE)活性成分的研磨工艺。目的是确定达到永久灭火所需MAP的最佳粒径的研磨时间。利用实验室陶瓷球磨机和振动杯磨机对MAP进行研磨。研磨过程是通过在精确规定的时间间隔内使用100 μ m筛网进行筛分来控制的。PFE的效率取决于有效组分中-100 μ m组分的比例,该比例必须超过60%。采用球磨机(单段磨矿)对- 3000 μ m mm粒径的MAP进行磨矿33 min后,获得了-100 μ m粒径比例为64%的最佳粒度。在两阶段工艺中,通过研磨相同的初始MAP样品(?在振动磨机中研磨10 min,可得到晶粒尺寸上限为300 μ m,平均晶粒直径为120 μ m的粉末。这个样本的大小进一步减少地面的陶瓷球磨机收益率报67.5%的分数粒度-100 ? m 19分钟。之后两级磨削过程的总时间是29分钟。通过分析地图需要的研磨时间粒度的要求的最低分数-100 ? m提供形成pfizer的有效性可以得出结论,64%的分数获得了33分钟的单级研磨后,而在两阶段过程中仅经过26分钟。因此,研磨时间减少了7分钟,节约了一定的能源。采用硬脂酸镁(MgSt)在球磨机中以2%的含量包覆PFE,获得了PFE的稳定性和疏水性。通过验证PFE与水滴接触疏水性的标准化程序对涂层进行了验证。所得PFE的组分质量比为MAP:AS:CC:QS:MgSt=55:20:18:5:2 (AS-硫酸铵;cs -碳酸钙,qs -石英砂),并通过化学和粒度分析进一步表征。PFE的灭火效率在受控条件下进行了测试,其中由燃烧固体材料和易燃液体引发的火灾。在这两种情况下,都实现了立即消除火焰,从而证明了本工作中获得的PFE在实际应用中的效率。
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引用次数: 0
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Chemical Industry
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