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Plasma treatment of gelatin photography 等离子体处理明胶摄影
IF 0.8 Q4 CHEMISTRY, MULTIDISCIPLINARY Pub Date : 2019-04-01 DOI: 10.2478/acs-2019-0005
Blanka Zachariášová, Katarína Haberová, M. Oravec, V. Jančovičová
Abstract Plasma pre-treatment represents the key enabler technology for microfine cleaning, surface activation and plasma coating of almost all types of materials — from plastics, metals and glasses to textiles, composites and photographs. More and more conventional industrial treatment methods are being replaced by plasma technology in order to make processes more effective and environmentally friendly. This study is oriented on the characterization of a photographic image on two types of photographic paper (glossy and matt photographic paper with a barite layer), and monitoring the effects induced by the Atmospheric Discharge with Runaway Electrons (ADRE) plasma in air atmosphere on the photographic image layers. To evaluate their long-term stability before/after plasma treatment, degradation of black and white gelatin photographic components upon accelerated light aging using Q-SUN was investigated and the photoinduced changes were recorded by FTIR spectroscopy, densitometry and colorimetry. The results obtained demonstrated that the plasma discharge had no significant destructive effect on the photographic image as only negligible changes in the structure of the gelatin were detected due to plasma processing. Consequently, it can be concluded that low-temperature ADRE plasma in air atmosphere has the potential for successful applications in microbial decontamination and purification of damaged gelatin photographs.
等离子体预处理是几乎所有类型材料(从塑料、金属和玻璃到纺织品、复合材料和照片)的微细清洗、表面活化和等离子体涂层的关键技术。越来越多的传统工业处理方法正被等离子体技术所取代,以使处理过程更有效和环保。本研究针对两种类型的照相纸(有重晶石层的光面照相纸和亚光照相纸)上的摄影图像进行表征,并监测大气中失控电子大气放电(ADRE)等离子体对摄影图像层的影响。为了评价其在等离子体处理前后的长期稳定性,采用Q-SUN研究了黑白明胶照相成分在加速光老化过程中的降解情况,并通过FTIR光谱、密度测定法和比色法记录了光致变化。结果表明,等离子体放电对照相图像没有显著的破坏性影响,因为等离子体处理只检测到明胶结构的可忽略不计的变化。因此,可以得出结论,低温ADRE等离子体在空气气氛中具有成功应用于微生物去污和纯化受损明胶照片的潜力。
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引用次数: 1
On local aromaticity of selected model aza-[n]circulenes (n = 6, 7, 8 and 9): Density functional theoretical study 关于所选模型aza-[n]环状物(n=6,7,8,9)的局部芳香性:密度泛函理论研究
IF 0.8 Q4 CHEMISTRY, MULTIDISCIPLINARY Pub Date : 2019-04-01 DOI: 10.2478/acs-2019-0011
D. Cagardová, Vladimír Lukes, J. Matúska, Peter Poliak
Abstract A computational study using density functional theory is reported for selected model aza[n]circulenes (n = 6, 7, 8 and 9) and their derivatives consisting of pyrrole and benzene units. Local aromaticity of central rings was discussed and analyzed using theoretical structural indices. Depending on their molecular structures, energies of the highest occupied and lowest unoccupied molecular orbitals change from –5.23 eV to –4.08 eV and from –1.97 eV to –0.41 eV, respectively. Based on B3LYP calculated optimal geometries, electronic structure of molecules and their charge transport properties resulted in the suggestion of three planar molecules containing three or four pyrrole units as potential candidates for p-type semiconductors. Hole drift mobilities for ideal stacked dimers of these potential semiconductors were calculated and they range from 0.94 cm2·V−1·s−1 to 7.33 cm2·V−1·s−1.
摘要利用密度泛函理论对所选模型氮杂环(n=6,7,8,9)及其由吡咯和苯单元组成的衍生物进行了计算研究。利用理论结构指数对中心环的局部芳香性进行了讨论和分析。根据其分子结构,最高被占据和最低未被占据分子轨道的能量分别从–5.23 eV变为–4.08 eV和从–1.97 eV变至–0.41 eV。基于B3LYP计算的最佳几何结构、分子的电子结构及其电荷传输特性,提出了含有三个或四个吡咯单元的三个平面分子作为p型半导体的潜在候选者。计算了这些潜在半导体的理想堆叠二聚体的空穴漂移迁移率,其范围为0.94 cm2·V−1·s−1至7.33 cm2·V–1·s–1。
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引用次数: 1
Influence of hydrotalcite preparation conditions on its physico-chemical properties 水滑石制备条件对其理化性能的影响
IF 0.8 Q4 CHEMISTRY, MULTIDISCIPLINARY Pub Date : 2019-04-01 DOI: 10.2478/acs-2019-0017
M. Mališová, M. Horňáček, P. Hudec, J. Mikulec, V. Jorík, E. Hájeková
Abstract The aim of the research was to prepare and characterize hydrotalcite synthesized under different preparation conditions. The most common hydrotalcite preparation is the co-precipiaton method. The preparation process strongly influences the catalytic properties of hydrotalcite; therefore, optimal conditions have to be determined. During the study, seven samples of the catalyst were prepared in the pH range from 8 to 12 and the synthesis temperature range from 25 to 55 °C. Based on several catalyst properties, optimal synthesis pH 10 was found. Ideal temperature of the preparation was determined to be 35 °C, but the temperature does not have a significant effect on the catalyst properties.
摘要本研究的目的是制备和表征在不同制备条件下合成的水滑石。最常见的水滑石制备方法是共沉淀法。制备工艺对水滑石的催化性能有很大影响;因此,必须确定最佳条件。在研究过程中,在8至12的pH范围和25至55°C的合成温度范围内制备了7个催化剂样品。基于几种催化剂的性质,找到了最佳合成pH 10。制备的理想温度确定为35°C,但温度对催化剂性能没有显著影响。
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引用次数: 2
Agile manoeuvres using model predictive control 使用模型预测控制的敏捷机动
IF 0.8 Q4 CHEMISTRY, MULTIDISCIPLINARY Pub Date : 2019-04-01 DOI: 10.2478/acs-2019-0019
Kristína Fedorová, Peter Bakaráč, M. Kvasnica
Abstract This paper shows how model predictive control (MPC) can be used to perform agile manoeuvres in a pendulum-on-a-cart system, which is an abstraction of many mechanical systems commonly used in the industry, such as cranes. Specifically, the problem of moving a cart on which a pendulum is mounted using a free joint is rapidly moved from one position to another one while mitigating the swings of the pendulum. To achieve this goal, an optimization-based MPC strategy is employed that selects the control moves while minimizing the chosen cost function and, simultaneously, enforcing constraint satisfaction. As the controlled system is nonlinear, two options are considered. The first one solves the nonlinear MPC problem in an approximate fashion using the so-called random shooting approach. The second method is based on the first one approximating the nonlinear system by a linear one, followed by applying convex MPC techniques. The performance of both strategies was compared by means of real-time experiments.
摘要本文展示了如何使用模型预测控制(MPC)在车载摆动系统中执行敏捷操作,该系统是工业中常用的许多机械系统(如起重机)的抽象。具体而言,使用自由接头移动安装有摆锤的推车的问题会从一个位置快速移动到另一个位置,同时减轻摆锤的摆动。为了实现这一目标,采用了一种基于优化的MPC策略,该策略选择控制动作,同时最小化所选的成本函数,同时强制满足约束。由于受控系统是非线性的,因此考虑了两种选择。第一种方法使用所谓的随机射击方法以近似的方式解决非线性MPC问题。第二种方法是基于第一种方法,用线性方法近似非线性系统,然后应用凸MPC技术。通过实时实验对两种策略的性能进行了比较。
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引用次数: 1
Synthesis, crystal structure, infrared spectrum, and thermal properties of [Ni(1,10-phenanthroline)3](fumarate)·9H2O complex with hydrogen bonded supramolecular layers involving fumarate anions 含富马酸阴离子的氢键超分子层[Ni(1,10-菲罗啉)3](富马酸)·9H2O配合物的合成、晶体结构、红外光谱和热性能
IF 0.8 Q4 CHEMISTRY, MULTIDISCIPLINARY Pub Date : 2019-04-01 DOI: 10.2478/acs-2019-0009
A. Uhrinová, J. Černák
Abstract From the aqueous-ethanolic system Ni(OH)2—H2fum—phen (H2fum = fumaric acid, phen = 1,10-phenanthroline), novel complex [Ni(phen)3](fum)·9H2O (1) was isolated and characterized by chemical analyses and FT-IR spectroscopy. Results of single crystal X-ray structure analysis have shown that the ionic crystal structure of 1 is built of [Ni(phen)3]2+ complex cations, fumarate dianions and nine crystallographically independent water molecules of crystallization. The Ni(II) atom exhibits hexa-coordination by three phen ligands with mean Ni-N bond length of 2.090 Å. Water molecules form hydrophilic supramolecular layers with fumarate dianions via extended network of O—H···O type hydrogen bonds with O···O distances from the range of 2.676(2)—2. 916(2) Å; hydrophobic complex cations are embedded between these layers. Thermal study of 1 has shown that endothermic dehydration in the temperature range of 95—195 °C takes at least two steps of the process. Graphical Abstract Crystal structure of [Ni(phen)3]fum·9H2O (phen = 1,10-phenanthroline; H2fum = fumaric acid) which is built of supramolecular layers formed by hydrogen bonded water solvate molecules and fum dianions and between the supramolecular layers embedded [Ni(phen)3]2+ complex cations is described here.
摘要从Ni(OH)2-H2fum-phen(H2fum=富马酸,phen=1,10-菲罗啉)乙醇水溶液体系中分离得到新型配合物[Ni(phen)3](fum)·9H2O(1),并用化学分析和红外光谱对其进行了表征。单晶X射线结构分析结果表明,1的离子晶体结构是由[Ni(phen)3]2+复合阳离子、富马酸二胺离子和9个结晶水分子组成的。Ni(II)原子通过三个phen配体表现出六配位,平均Ni-N键长为2.090Å。水分子通过O-H··O型氢键的扩展网络与富马酸二阴离子形成亲水性超分子层,O··O距离在2.676(2)-2范围内。916(2)Å;疏水性复合阳离子嵌入在这些层之间。对1的热研究表明,在95-195°C的温度范围内吸热脱水至少需要两个步骤。本文描述了[Ni(phen)3]fum·9H2O(phen=1,10-菲罗啉;H2fum=富马酸)的晶体结构,该晶体由氢键水溶剂化物分子和fum二胺离子形成的超分子层以及嵌入[Ni(Phn)3]2+复合阳离子的超分子层之间构建。
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引用次数: 1
Thermodynamics of primary antioxidant action of flavonols in polar solvents 黄酮醇在极性溶剂中主要抗氧化作用的热力学研究
IF 0.8 Q4 CHEMISTRY, MULTIDISCIPLINARY Pub Date : 2019-04-01 DOI: 10.2478/acs-2019-0016
M. Michalík, J. Rimarčík, Vladimír Lukes, E. Klein
Abstract Very recently, a report on the antioxidant activity of flavonoids has appeared, where authors concluded that Hydrogen Atom Transfer mechanism represents the thermodynamically preferred mechanism in polar media (https://doi.org/10.1016/j.foodres.2018.11.018). Unfortunately, serious errors in the theoretical part of the paper led to incorrect conclusions. For six flavonols (galangin, kaempferol, quercetin, morin, myricetin, and fisetin), reaction enthalpies related to three mechanisms of the primary antioxidant action were computed. Based on the obtained results, the role of intramolecular hydrogen bonds (IHB) in the thermodynamics of the antioxidant effect is presented. Calculations and the role of solvation enthalpies of proton and electron in the determination of thermodynamically preferred mechanism is also briefly explained and discussed. The obtained results are in accordance with published works considering the Sequential Proton-Loss Electron-Transfer thermodynamically preferred reaction pathway.
摘要最近,一篇关于黄酮类化合物抗氧化活性的报道发表了,作者得出结论,氢原子转移机制代表了在极性介质中热力学优选的机制(https://doi.org/10.1016/j.foodres.2018.11.018)。不幸的是,论文理论部分的严重错误导致了错误的结论。计算了六种黄酮醇(高良姜、山奈酚、槲皮素、桑色素、杨梅素和非西汀)与三种主要抗氧化作用机制相关的反应焓。基于所得结果,提出了分子内氢键(IHB)在抗氧化作用热力学中的作用。还简要解释和讨论了质子和电子的溶剂化焓的计算以及在确定热力学优选机理中的作用。考虑到顺序质子损失电子转移热力学优选反应途径,所获得的结果与已发表的工作一致。
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引用次数: 3
Substrate inhibition and pH effect on denitritation with granular biomass 基质抑制和pH对颗粒状生物质反硝化的影响
IF 0.8 Q4 CHEMISTRY, MULTIDISCIPLINARY Pub Date : 2019-04-01 DOI: 10.2478/acs-2019-0013
Stanislava Kecskésová, Zuzana Imreová, Bibiána Kožárová, J. Derco, M. Drtil
Abstract Undissociated HNO2 (up to 2 mg dm−3) was confirmed as substrate inhibitor for granular biomass from a denitritation upflow sludge bed reactor used for biological removal of nitrite. On the contrary, total nitrite nitrogen (N-NO2 up to 500 mg dm−3) and methanol (COD up to 2000 mg dm−3) were not proven to be inhibitors. pH also affected the denitritation efficiency (optimal pH was 5.9). Reduction of HNO2 concentration in the reactor by effluent recycling is recommended.
摘要无缔合HNO2(高达2 mg dm−3)被证实是反硝化上流污泥床反应器中颗粒生物质的底物抑制剂,该反应器用于生物去除亚硝酸盐。相反,总亚硝酸盐氮(N-NO2高达500 mg dm−3)和甲醇(COD高达2000 mg dm−2)未被证明是抑制剂。pH值也影响反硝化效率(最佳pH值为5.9)。建议通过废水再循环降低反应器中HNO2的浓度。
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引用次数: 0
An active indirect solar system for food products drying 一种用于食品干燥的主动间接太阳能系统
IF 0.8 Q4 CHEMISTRY, MULTIDISCIPLINARY Pub Date : 2019-04-01 DOI: 10.2478/acs-2019-0020
A. Noori, Mohammad Jafar Royen, J. Haydary
Abstract An energy independent active indirect solar drying system for the study of food products drying at specific climate conditions was developed and tested. As a model material, sliced tomato was selected because of its short shelf live, high humidity and potential to be a high value dried product. Indirect solar dryer enabled complete protection of the dried material against sunlight, birds, insects, rain and dust during the drying process. The solar dryer system design includes a rectangular section (1000 × 600 × 400) mm chamber and a flat solar collector (1500 × 600 × 100) mm with the surface area of 0.9 m2. Air flow was induced by a fan installed at the inlet of the collector and powered by a photovoltaic solar panel and a battery system. Temperature and humidity of air were monitored at the collector inlet, collector outlet and the drying chamber outlet. The key element of the collector is a 10.5 m long rectangular section aluminum pipe (55 × 35) mm coated with an absorption layer. The maximum dryer capacity is around 3 kg of wet material (sliced tomato) per batch. Average air temperature increase in the collector was measured to be 30 °C during the winter season. Air relative humidity decreased from 21 % to 15 % after passing through the collector. The moisture of tomato slices decreased from the initial value of 92 % down to 22 % during the time of the experiment (30 h). Quality of tomatoes dried using the designed solar dryer differed significantly in color as well as in texture from those dried by the commonly used methods, like an open sun drying system. Equilibrium moisture content of the product was reached after 30 h in December when the maximum outside temperature was 17.6 °C. The tomato mass decreased from 333 g to 33.15 g; the mass loss being approximately 90 %. The heated air temperature and humidity at the dryer inlet and outlet were influenced by the change of the ambient temperature and humidity during the day. Variation of the drying rate with the change of the ambient temperature and humidity was observed. During summer, when the sun radiation increases, the drying time for sliced tomato with 9 mm thickness decreased from 25 h to 15 h. The sample thickness also has an impact on the drying process. When the sample thickness increased from 9 mm to 12 mm, the drying time increased from 15 h to 20 h of active device time.
摘要开发并测试了一种用于研究特定气候条件下食品干燥的能量独立主动间接太阳能干燥系统。选择番茄切片作为模型材料是因为它的保质期短、湿度高,并且有可能成为高价值的干燥产品。间接太阳能烘干机能够在烘干过程中完全保护烘干材料免受阳光、鸟类、昆虫、雨水和灰尘的影响。太阳能干燥器系统设计包括一个矩形截面(1000×600×400)mm的腔室和一个表面积为0.9 m2的平面太阳能收集器(1500×600×100)mm。气流是由安装在收集器入口处的风扇引起的,风扇由光伏太阳能电池板和电池系统供电。在收集器入口、收集器出口和干燥室出口监测空气的温度和湿度。收集器的关键元件是一根10.5米长的矩形截面铝管(55×35)毫米,上面涂有吸收层。最大烘干机容量约为每批3公斤湿材料(番茄切片)。在冬季,收集器中的平均空气温度升高为30°C。经过收集器后,空气相对湿度从21%下降到15%。在实验期间(30小时),番茄片的水分从92%的初始值下降到22%。使用设计的太阳能烘干机烘干的番茄在颜色和质地上与使用常用方法(如露天烘干系统)烘干的番茄有显著差异。产品的平衡含水量在12月30小时后达到,当时最高外部温度为17.6°C。番茄的质量从333克下降到33.15克;质量损失大约为90%。干燥器入口和出口处的加热空气温度和湿度受白天环境温度和湿度变化的影响。观察了干燥速率随环境温度和湿度的变化。在夏季,当太阳辐射增加时,厚度为9mm的番茄切片的干燥时间从25小时减少到15小时。样品厚度也对干燥过程有影响。当样品厚度从9mm增加到12mm时,干燥时间从有源器件时间的15h增加到20h。
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引用次数: 5
Remediation potential of bacterial mixed cultures for polychlorinated biphenyls (PCBs) biodegradation 细菌混合培养物对多氯联苯(PCBs)生物降解的修复潜力
IF 0.8 Q4 CHEMISTRY, MULTIDISCIPLINARY Pub Date : 2019-04-01 DOI: 10.2478/acs-2019-0001
H. Horváthová, K. Lászlová, K. Dercová
Abstract Remediation of polychlorinated biphenyls (PCBs) in minimal mineral water media in the presence of bacterial mixed cultures consisting of several individual strains is proposed. Starting from the fact that the properties and features of bacterial strains in mixed cultures can be supplemented and compensated, two-, three- and seven-membered mixed cultures (MC) were performed. The strains used for the construction of the MC were isolated from the waste canal of a former PCB producer. The highest biodegradation of 70 % of the sum of seven defined PCB congeners was achieved by two-membered MC containing the strains Rhodococcus sp. and Stenotrophomonas maltophilia added in the biomass ratio of 1 : 3 and 3 : 1. PCB biodegradation by a seven-membered MC was lower (58 %) but provided several benefits over the less-membered mixed cultures or the individual strains: similarity to naturally occurring microflora, easier preparation of the inocula, certain and repeatable results. Periodical reinoculation of the water media resulted to PCB biodegradation increase to 65 %. Seven-membered MC was applied to the historically PCB contaminated sediment as well, where a 59 % degradation of the sum of seven PCB congeners was determined.
摘要提出了在由几个菌株组成的细菌混合培养物存在的情况下,在最低限度的矿泉水介质中修复多氯联苯(PCBs)的方法。从混合培养中菌株的特性和特征可以得到补充和补偿的事实出发,进行了二元、三元和七元混合培养(MC)。用于构建MC的菌株是从一家前PCB生产商的废水渠中分离出来的。通过以1∶3和3∶1的生物量比添加含有菌株Rhodococcus sp.和嗜麦芽窄食单胞菌的两元MC,实现了七种已定义的多氯联苯同源物之和的70%的最高生物降解。七元MC对多氯联苯的生物降解率较低(58%),但与少元混合培养物或单个菌株相比,它提供了几个好处:与天然存在的微生物群落相似,更容易制备接种物,具有一定的可重复结果。定期重新接种水介质可使多氯联苯的生物降解率提高到65%。七元MC也被应用于历史上受多氯联苯污染的沉积物,其中确定了七种多氯联苯同源物的总降解率为59%。
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引用次数: 1
Batch drying of sliced tomatoes at specific ambient conditions 番茄切片在特定环境条件下的分批干燥
IF 0.8 Q4 CHEMISTRY, MULTIDISCIPLINARY Pub Date : 2018-10-01 DOI: 10.2478/acs-2018-0019
Mohammad Jafar Royen, A. Noori, J. Haydary
Abstract In this work, drying of tomato slices was studied in a laboratory scale batch dryer working at conditions specific for geographical locations with low ambient pressure and low relative humidity of air. Tomato is a perishable farm product with high moisture content. Despite their high value, tomatoes are subjected to wastage and spoilage during their seasonal period; to last longer after harvested, they need to be treated by drying. Drying is one of the most widely used methods of tomato preserving for a longer period of time. This study involves experimental work on tomatoes drying in a tray laboratory batch dryer with the dimensions of (490 × 330 × 310) mm, a load cell-force sensor (range: 0–5 kg), fan (speed: 0–2500 rpm), air flow sensor (0–150 l/min) and a temperature and humidity monitoring system. This study was aimed at the development of a suitable drying method for the production of dehydrated agricultural products under specific air properties and climate conditions such as low ambient pressure and low relative humidity. During the experiment, the average ambient pressure was 82 kPa, and the average relative humidity of air was 20 %. Drying characteristics of tomato slices were determined at three temperature levels, namely: 50 °C, 60 °C and 70 °C,and three air flow rates: 30 l/s, 40 l/s and 50 l/s, for each temperature level. In this study, the effect of temperature, air flow rate, and ambient conditions on the drying rate of tomato slices were studied. The results indicate that during the experiments, tomatoes were dried to the final moisture content of 32.2 % from 92 %. Drying time at 50 °C, 60 °C and 70°C, and air flow of 30 l/s was 17.80 h, 15.80 h, and 14.08 h, respectively. For the air flow rate of 40 l/s, the drying time was 15.0 h, 12.9 h and 11.7 h and for the air flow rate of 50 l/s, the drying time of tomato slices was 14.0 h, 11.6 h and 10.2 h, respectively.
摘要在这项工作中,在实验室规模的间歇式干燥机中,在低环境压力和低空气相对湿度的特定地理位置的条件下,对番茄切片的干燥进行了研究。番茄是一种易腐烂的农产品,水分含量高。尽管西红柿的价值很高,但在季节性时期,它们会被浪费和变质;为了在收获后持续更长时间,它们需要经过干燥处理。干燥是番茄保存时间最长的方法之一。本研究涉及在尺寸为(490×330×310)mm的托盘实验室分批干燥机、称重传感器(范围:0-5 kg)、风扇(转速:0-2500 rpm)、空气流量传感器(0-150 l/min)和温度和湿度监测系统中对番茄进行干燥的实验工作。本研究旨在开发一种合适的干燥方法,用于在特定的空气特性和气候条件下生产脱水农产品,如低环境压力和低相对湿度。在实验期间,平均环境压力为82kPa,空气的平均相对湿度为20%。番茄切片的干燥特性是在三个温度水平下测定的,即:50°C、60°C和70°C,以及三种空气流速:每种温度水平30 l/s、40 l/s和50 l/s。在本研究中,研究了温度、空气流量和环境条件对番茄切片干燥速率的影响。结果表明,在实验过程中,番茄的最终含水量从92%降至32.2%。在50°C、60°C和70°C以及30 l/s的空气流量下的干燥时间分别为17.80小时、15.80小时和14.08小时。对于40l/s的空气流速,番茄片的干燥时间分别为15.0小时、12.9小时和11.7小时;对于50l/s的气流流速,番茄切片的干燥时间为14.0小时、11.6小时和10.2小时。
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引用次数: 3
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Acta Chimica Slovaca
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