Search results for: chemical analyses

Authors: Marina Borgert Moraes, Gilmar Patrocinio Thim

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It is still unknown how the presence of nanoparticles such as graphene oxide (GO) or carbon nanotubes (CNT) influence the curing process and the final mechanical properties as well. In this work, kinetic and mechanical properties of the nanocomposites were analyzed, where the kinetic process was followed by DSC and the mechanical properties by DMA as well as mechanical tests. Initially, CNT was annealed at high temperature (1800 °C) under vacuum atmosphere, followed by a chemical treatment using acids and ethylenediamine. GO was synthesized through chemical route, washed clean, dried and ground to #200. The presence of functional groups on CNT and GO surface was confirmed by XPS spectra and FT-IR. Then, nanoparticles and acetone were mixed by sonication in order to obtain the composites. DSC analyses were performed on samples with different curing cycles (1h 80 °C + 2h 120 °C; 3h 80 °C + 2h 120 °C; 5h 80 °C) and samples with different times at constant temperature (120 °C). Mechanical tests were performed according to ASTM D638 and D790. Results showed that the kinetic process and the mechanical strength are very dependent on the presence of graphene and functionalized-CNT in the nanocomposites, and the GO reinforced samples had a slightly bigger improvement compared to functionalized CNT.

Keywords: carbon nanotube, epoxy resin, graphene oxide, nanocomposite

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Authors: C. Alexandridou, G. N. Angelopoulos, F. A. Coutelieris

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Construction industry in Greece consumes annually more than 25 million tons of natural aggregates originating mainly from quarries. At the same time, more than 2 million tons of construction and demolition waste are deposited every year, usually without control, therefore increasing the environmental impact of this sector. A potential alternative for saving natural resources and minimize landfilling, could be the recycling and re-use of Concrete and Demolition Waste (CDW) in concrete production. Moreover, in order to conform to the European legislation, Greece is obliged to recycle non-hazardous construction and demolition waste to a minimum of 70% by 2020. In this paper characterization of recycled materials - commercially and laboratory produced, coarse and fine, Recycled Concrete Aggregates (RCA) - has been performed. Namely, X-Ray Fluorescence and X-ray diffraction (XRD) analysis were used for chemical and mineralogical analysis respectively. Physical properties such as particle density, water absorption, sand equivalent and resistance to fragmentation were also determined. This study, first time made in Greece, aims at outlining the differences between RCA and natural aggregates and evaluating their possible influence in concrete performance. Results indicate that RCA’s chemical composition is enriched in Si, Al, and alkali oxides compared to natural aggregates. X-ray diffraction (XRD) analyses results indicated the presence of calcite, quartz and minor peaks of mica and feldspars. From all the evaluated physical properties of coarse RCA, only water absorption and resistance to fragmentation seem to have a direct influence on the properties of concrete. Low Sand Equivalent and significantly high water absorption values indicate that fine fractions of RCA cannot be used for concrete production unless further processed. Chemical properties of RCA in terms of water soluble ions are similar to those of natural aggregates. Four different concrete mixtures were produced and examined, replacing natural coarse aggregates with RCA by a ratio of 0%, 25%, 50% and 75% respectively. Results indicate that concrete mixtures containing recycled concrete aggregates have a minor deterioration of their properties (3-9% lower compression strength at 28 days) compared to conventional concrete containing the same cement quantity.

Keywords: chemical and physical characterization, compressive strength, mineralogical analysis, recycled concrete aggregates, waste management

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Authors: S. Redjala, N. Ait Hocine, M. Gratton, N. Poirot, R. Ferhoum, S. Azem

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Polycarbonate (PC) is a promising polymer with high transparency in the range of the visible spectrum and is used in various fields, for example medical, electronic, automotive. Its low weight, chemical inertia, high impact resistance and relatively low cost are of major importance. In recent decades, some materials such as metals and ceramics have been replaced by polymers because of their superior advantages. However, some characteristics of the polymers are highly modified under the effect of ultraviolet (UV) radiation and temperature. The changes induced in the material by such aging depend on the exposure time, the wavelength of the UV radiation and the temperature level. The UV energy is sufficient to break the chemical bonds leading to a cleavage of the molecular chains. This causes changes in the mechanical, thermal, optical and morphological properties of the material. The present work is focused on the study of the effects of aging under ultraviolet (UV) radiation and under different temperature values on the physical-chemical and mechanical properties of a PC. Thus, various investigations, such as FTIR and XRD analyses, SEM and optical microscopy observations, micro-hardness measurements and monotonic and cyclic tensile tests, were carried out on the PC in the initial state and after aging. Results have shown the impact of aging on the properties of the PC studied. In fact, the MEB highlighted changes in the superficial morphology of the material by the presence of cracks and material de-bonding in the form of debris. The FTIR spectra reveal an attenuation of the peaks like the hydroxyl (OH) groups located at 3520 cm-1. The XRD lines shift towards a larger angle, reaching a maximum of 3°. In addition, Vickers micro-hardness measurements show that aging affects the surface and the core of the material, which results in different mechanical behaviours under monotonic and cyclic tensile tests. This study pointed out effects of aging on the macroscopic properties of the PC studied, in relationship with its microstructural changes.

Keywords: mechanical properties, physical-chemical properties, polycarbonate, UV aging, temperature aging

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Authors: Hounyèmè Romuald, Maxime Logez, Mama Daouda, Argillier Christine

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In view of the very strong degradation of aquatic ecosystems, it is urgent to set up monitoring systems that are best able to report on the effects of the stresses they undergo. This is particularly true in developing countries, where specific and relevant quality standards and funding for monitoring programs are lacking. The objective of this study was to make a relevant and objective choice of physicochemical parameters informative of the main stressors occurring on African lakes and to identify their alteration thresholds. Based on statistical analyses of the relationship between several driving forces and the physicochemical parameters of the Nokoué lagoon, relevant Physico-chemical parameters were selected for its monitoring. An innovative method based on Bayesian statistical modeling was used. Eleven Physico-chemical parameters were selected for their response to at least one stressor and their threshold quality standards were also established: Total Phosphorus (<4.5mg/L), Orthophosphates (<0.2mg/L), Nitrates (<0.5 mg/L), TKN (<1.85 mg/L), Dry Organic Matter (<5 mg/L), Dissolved Oxygen (>4 mg/L), BOD (<11.6 mg/L), Salinity (7.6 .), Water Temperature (<28.7 °C), pH (>6.2), and Transparency (>0.9 m). According to the System for the Evaluation of Coastal Water Quality, these thresholds correspond to” good to medium” suitability classes, except for total phosphorus. One of the original features of this study is the use of the bounds of the credibility interval of the fixed-effect coefficients as local weathering standards for the characterization of the Physico-chemical status of this anthropized African ecosystem.

Keywords: driving forces, alteration thresholds, acadjas, monitoring, modeling, human activities

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Authors: Mohammad Reza Ameri, Ali Massumi, Mohammad Haghbin

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Non-linear static analysis, commonly referred to as pushover analysis, is a powerful tool for assessing the seismic response of structures. A suitable lateral load pattern for pushover analysis can bring the results of this simple, quick and low-cost analysis close to the realistic results of nonlinear dynamic analyses. In this research, four samples of 10- and 15 story (two- and four-bay) reinforced concrete frames were studied. The lateral load distribution patterns recommended in FEMA 273/356 guidelines were applied to the sample models in order to perform pushover analyses. The results were then compared to the results obtained from several nonlinear incremental dynamic analyses for a range of earthquakes. Finally, a lateral load distribution pattern was proposed for pushover analysis of medium-rise reinforced concrete buildings based on the results of nonlinear static and dynamic analyses.

Keywords: lateral load pattern, nonlinear static analysis, incremental dynamic analysis, medium-rise reinforced concrete frames, performance based design

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Authors: Sadia Ameen, M. Nazim, Hyumg-Kee Seo, Hyung-Shik Shin

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TiO2 nanotube (NT) arrays were grown on titanium (Ti) foil substrate by electrochemical anodic oxidation and utilized as working electrode to fabricate a highly sensitive and reproducible chemical sensor for the detection of harmful phenyl hydrazine chemical. The fabricated chemical sensor based on TiO2 NT arrays electrode exhibited high sensitivity of ~40.9 µA.mM-1.cm-2 and detection limit of ~0.22 µM with short response time (10s).

Keywords: TiO2 NT, phenyl hydrazine, chemical sensor, sensitivity, electrocatalytic properties

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Authors: Zellagui Rahima, Chaumont Denis, Boughelout Abderrahman, Adnane Mohamed

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Thin films of CdxZn1-xS were deposed by chemical bath deposition on glass substrates for photovoltaic applications. The thin films CdZnS were synthesized by chemical bath (CBD) with different deposition protocols for optimized the parameter of deposition as the temperature, time of deposition, concentrations of ion and pH. Surface morphology, optical and chemical composition properties of thin film CdZnS were investigated by SEM, EDAX, spectrophotometer. The transmittance is 80% in visible region 300 nm – 1000 nm; it has been observed in that films the grain size is between 50nm and 100nm measured by SEM image and we also note that the shape of particle is changing with the change in concentration. This result favors of application these films in solar cells; the chemical analysis with EDAX gives information about the presence of Cd, Zn and S elements and investigates the stoichiometry.

Keywords: thin film, solar cells, transmition, cdzns

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Authors: Felora Rafiei, Shahram Shoaei

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The aim of this studies was to evaluate effect of nitroxin, super nitro plus and biophosphorus on yield and yield components of maize (Zea mays) under different levels of chemical fertilizers in the condition of normal and difficiet irrigation. Experiment laid out as split plot factorial based on randomized complete block design with three replications. Main plots includes two irrigation treatments of 70 (I1), 120(I2) mm evaporation from class A pan. Sub plots were biological fertilizer and chemical fertilizer as factorial biological fertilizer consisting of nitroxin: Azospirillium lipoferum, Azospirillium brasilens, Azotobacter chroococcum Azotobacter agilis (108 CFU ml-1) (B1), super nitro plus (Azospirillium spp, + Pseudomonas fluorescence + Bacillus subtilis (108 CFU ml-1) + biological fungicide) (B2), biophosphorus (Pseudomonas spp + Bacillus spp (107 CFU ml-1) (B3), and chemical fertilizer consisting of NPK (C1), N5oP5oK5o (C2) and NoPoKo (C3).The results showed that usage of biological fertilizer have positive effects on chemical fertilizers use efficiency and tolerance to drought stress in maize. Also with use of biological fertilizer can decrease usage of chemical fertilizers.

Keywords: biological fertilizer, chemical fertilizer, yield component, yield, corn

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Authors: Anna S. Tolkacheva, Sergey N. Shkerin, Kirill G. Zemlyanoi, Olga G. Reznitskikh, Pavel D. Khavlyuk

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Calcium oxovanadates with garnet related structure are multifunctional oxides in various fields like photoluminescence, microwave dielectrics, and magneto-dielectrics. For example, vanadate garnets are self-luminescent compounds. They attract attention as RE-free broadband excitation and emission phosphors and are candidate materials for UV-based white light-emitting diodes (WLEDs). Ca₅M₄(VO₄)₆ (M = Mg, Zn, Co, Ni, Mn) compounds are also considered promising for application in microwave devices as substrate materials. However, the relation between their structure, composition and physical/chemical properties remains unclear. Given the above-listed observations, goals of this study are to synthesise Ca₅M₄(VO₄)₆ (M = Mg, Zn, Ni) and to study their thermal and electrical properties. Solid solutions Ca₅Mg₄₋ₓMₓ(VO₄)₆ (0 ≤ x ≤ 4) where M is Zn and Ni have been synthesized by sol-gel method. The single-phase character of the final products was checked by powder X-ray diffraction on a Rigaku D/MAX-2200 X-ray diffractometer using Cu Kα radiation in the 2θ range from 15° to 70°. The dependence of thermal properties on chemical composition of solid solutions was studied using simultaneous thermal analyses (DSC and TG). Thermal analyses were conducted in a Netzch simultaneous analyser STA 449C Jupiter, in Ar atmosphere, in temperature range from 25 to 1100°C heat rate was 10 K·min⁻¹. Coefficients of thermal expansion (CTE) were obtained by dilatometry measurements in air up to 800°C using a Netzsch 402PC dilatometer; heat rate was 1 K·min⁻¹. Impedance spectra were obtained via the two-probe technique with an impedance meter Parstat 2273 in air up to 700°C with the variation of pH₂O from 0.04 to 3.35 kPa. Cation deficiency in Ca and Mg sublattice under the substitution of MgO with ZnO up to 1/6 was observed using Rietveld refinement of the crystal structure. Melting point was found to decrease with x changing from 0 to 4 in Ca₅Mg₄₋ₓMₓ(VO₄)₆ where M is Zn and Ni. It was observed that electrical conductivity does not depend on air humidity. The reported study was funded by the RFBR Grant No. 17–03–01280. Sample attestation was carried out in the Shared Access Centers at the IHTE UB RAS.

Keywords: garnet structure, electrical conductivity, thermal expansion, thermal properties

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Authors: S. Benessam, T. H. Debieche, A. Drouiche, F. Zahi, S. Mahdid

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The intensive use of the chemical fertilizers and the pesticides in agriculture often produces a contamination of the groundwater by organic pollutants. The irrigation and/or rainwater transport the pollutants towards groundwater or water surface. Among these pollutants, one finds the nitrogen, often observed in the agricultural zones in the nitrate form. In order to understand the form and chemical mobility of nitrogen in groundwater, this study was conducted. A two-monthly monitoring of the parameters physicochemical and chemistry of water of the alluvial plain of Nil river (North-eastern Algerian) were carried out during the period from November 2013 to January 2015 as well as an in-situ investigation of the various chemical products used by the farmers. The results show a raise concentration of nitrates in the wells (depth < 20 m) of the plain, which the concentrations arrive at 50 mg/L (standard of potable water). On the other hand in drillings (depth > 20 m), one observes two behaviors. The first in the upstream part, where the aquifer is unconfined and the medium is oxidizing, one observes the weak nitrate concentrations, indicating its absorption by the ground during the infiltration of water towards the groundwater. The second in the central and downstream parts, where the groundwater is locally confined and the reducing medium, one observes an absence of nitrates and the appearance of nitrites and ammonium, indicating the reduction of nitrates. The projection of the analyses on diagrams Eh-pH of nitrogen has enabled to us to determine the intervals of variation of the nitrogen forms. This study also highlighted the effect of the rains, the pumping and the nature of the geological formations in the form and the mobility of nitrogen in the plain.

Keywords: groundwater, nitrogen, mobility, speciation

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Authors: Paulomi Polly Burey, Mark Lynch

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It has been shown that laboratory activities can help cement understanding of theoretical concepts, but it is difficult to deliver such an activity to an online cohort and issues such as occupational health and safety in the students’ learning environment need to be considered. Chemistry, in particular, is one of the sciences where practical experience is beneficial for learning, however typical university experiments may not be suitable for the learning environment of a distance learner. Food provides an ideal medium for demonstrating chemical concepts, and along with a few simple physical and virtual tools provided by educators, analytical chemistry can be experienced by distance learners. Food chemistry experiments were designed to be carried out in a home-based environment that 1) Had sufficient scientific rigour and skill-building to reinforce theoretical concepts; 2) Were safe for use at home by university students and 3) Had the potential to enhance student learning by linking simple hands-on laboratory activities with high-level virtual science. Two main components of the resources were developed, a home laboratory experiment component, and a virtual laboratory component. For the home laboratory component, students were provided with laboratory kits, as well as a list of supplementary inexpensive chemical items that they could purchase from hardware stores and supermarkets. The experiments used were typical proximate analyses of food, as well as experiments focused on techniques such as spectrophotometry and chromatography. Written instructions for each experiment coupled with video laboratory demonstrations were used to train students on appropriate laboratory technique. Data that students collected in their home laboratory environment was collated across the class through shared documents, so that the group could carry out statistical analysis and experience a full laboratory experience from their own home. For the virtual laboratory component, students were able to view a laboratory safety induction and advised on good characteristics of a home laboratory space prior to carrying out their experiments. Following on from this activity, students observed laboratory demonstrations of the experimental series they would carry out in their learning environment. Finally, students were embedded in a virtual laboratory environment to experience complex chemical analyses with equipment that would be too costly and sensitive to be housed in their learning environment. To investigate the impact of the intervention, students were surveyed before and after the laboratory series to evaluate engagement and satisfaction with the course. Students were also assessed on their understanding of theoretical chemical concepts before and after the laboratory series to determine the impact on their learning. At the end of the intervention, focus groups were run to determine which aspects helped and hindered learning. It was found that the physical experiments helped students to understand laboratory technique, as well as methodology interpretation, particularly if they had not been in such a laboratory environment before. The virtual learning environment aided learning as it could be utilized for longer than a typical physical laboratory class, thus allowing further time on understanding techniques.

Keywords: chemistry, food science, future pedagogy, STEM education

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Authors: Adejo Andrew Ojonugwa, Jomboh Jeff Kator, Garkida Adele Dzikwi

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This study investigates the behaviour of textured glass coat to chemical reactions upon application. Samples of textured glass coat developed from mixed post consumer glass were subjected to pH test (ASTM D5464), Chemical resistance test (ASTM D3260 and D1308), Adhesion test (ASTM D3359), and Abrasion test (ASTM D4060). Results shows a pH of 8.50, Chemical resistance of 5% flick rate when reacted with Sodium hydroxide (NaOH), a 3%, 5%, 10%, and 15% discolouration when reacted with Magnesium hydroxide (Mg(OH)2), Hydrogen fluoride (HF), Potassium hydroxide (KOH) and NaOH respectively, an adhesion of 4A and abrasion of 0.2g. The results confirm that the developed textured glass coat is in line with the standard pH range of 8-9, resistant to acid and base except for HF, NaOH, and Mg(OH)₂, good adhesion and abrasion properties, thereby making the coat resistant to chemical degradation and a good engineering material.

Keywords: chemical durability, glass-coat, building, recycling

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Authors: Shokofeh Ebrtahimi

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Let G be the chemical graph of a molecule. The matrix D = [dij ] is called the detour matrix of G, if dij is the length of longest path between atoms i and j. The sum of all entries above the main diagonal of D is called the detour index of G.Chemical graph theory is the topology branch of mathematical chemistry which applies graph theory to mathematical modelling of chemical phenomena.[1] The pioneers of the chemical graph theory are Alexandru Balaban, Ante Graovac, Ivan Gutman, Haruo Hosoya, Milan Randić and Nenad TrinajstićLet G be the chemical graph of a molecule. The matrix D = [dij ] is called the detour matrix of G, if dij is the length of longest path between atoms i and j. The sum of all entries above the main diagonal of D is called the detour index of G. In this paper, a new program for computing the detour index of molecular graphs of nanotubes by heptagons is determineded. Some Conjectures about detour index of Molecular graphs of nanotubes is included.

Keywords: chemical graph, detour matrix, Detour index, carbon nanotube

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Authors: Ernesto Linan, Linda Cruz, Lucero Becerra

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In this paper, a new hybridized algorithm based on Chemical Reaction Optimization and Simulated Annealing is proposed to solve the alignment sequence Problem. The Chemical Reaction Optimization is a population-based meta-heuristic algorithm based on the principles of a chemical reaction. Simulated Annealing is applied to solve a large number of combinatorial optimization problems of general-purpose. In this paper, we propose hybridization between Chemical Reaction Optimization algorithm and Simulated Annealing in order to solve the Sequence Alignment Problem. An initial population of molecules is defined at beginning of the proposed algorithm, where each molecule represents a sequence alignment problem. In order to simulate inter-molecule collisions, the process of Chemical Reaction is placed inside the Metropolis Cycle at certain values of temperature. Inside this cycle, change of molecules is done due to collisions; some molecules are accepted by applying Boltzmann probability. The results with the hybrid scheme are better than the results obtained separately.

Keywords: chemical reaction optimization, sequence alignment problem, simulated annealing algorithm, metaheuristics

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Authors: Anahita Yarahmadi, Nazanin Mahboobi, Nahid Sadat Rahmatpour Nori, Mohammad Hossein Bijeh Keshavarzi, Mohammad Javad Shakori

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This research aimed at considering biological fertilizer effect and chemical fertilizer on the quantitative characteristics of Sweet wormwood (Artemisia annua L.), an experiment was carried out in factorial design in completely randomized design with 4 replications in an experimental greenhouse which was located in Tehran. Experimental treatment involved chemical fertilizers (Nitrogen, Phosphorus) in4 levels and biological fertilizers in 4 levels (control, Nitroxin, Bio-phosphorus and Vemricompost). Results showed that using biological fertilizers and increasing different levels of chemical fertilizers (N, P) had significant effects on all the characteristics. Considering means comparison showed that biological fertilizers lead to significant enhancement on all the characteristics and among biological fertilizers, Vermicompost treatment has the most effect. Considering means comparison tables of different levels of chemical fertilizer have been found that (N80P80) had the most increase on characteristics.

Keywords: Artemisia annua L, bio-fertilizer, chemical fertilizer, vermicompost

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Authors: Guohua Cao, Xu Dong

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X-ray Fluorescence Molecular Imaging (XFMI) holds great promise as a low-cost molecular imaging modality for biomedical applications with high chemical sensitivity. However, for in vivo biomedical applications, a key technical bottleneck is the relatively low chemical sensitivity of XFMI, especially at a reasonably low radiation dose. In laboratory x-ray source based XFMI, one of the main factors that limits the chemical sensitivity of XFMI is the scattered x-rays. We will present our latest findings on improving the chemical sensitivity of XFMI using excitation beam spectrum optimization. XFMI imaging experiments on two mouse-sized phantoms were conducted at three different excitation beam spectra. Our results show that the minimum detectable concentration (MDC) of iodine can be readily increased by five times via excitation spectrum optimization. Findings from this investigation could find use for in vivo pre-clinical small-animal XFMI in the future.

Keywords: molecular imaging, X-ray fluorescence, chemical sensitivity, X-ray scattering

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Authors: Reda Abdel-Aziz

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Agricultural activities in Egypt generate annually around 35 million tons of waste. Composting is one of the most promising technologies to turnover waste in a more economical way, for many centuries. Composting has been used as a mean of recycling organic matter back into the soil to improve soil structure and fertility. Field experiments were conducted in two governorates, Giza and Al-Monofia, to find out the effect of compost with different rates of chemical fertilizers on growth and yield of corn (Zea mays L.) during two constitutive seasons of 2012 and 2013. The experiment, laid out in a randomized complete block design (RCBD), was carried out on five farmers’ fields in each governorate. The treatments were: unfertilized control, full dose of NPK (120, 30, and 50 kg/acre, respectively), compost at rate of 20 ton/acre, compost at rate of 10 ton/acre + 25% of chemical fertilizer, compost at rate of 10 ton/acre + 50% of chemical fertilizer and compost at rate of 10 ton/acre + 75% of chemical fertilizer. Results revealed a superiority of the treatment of compost at rate of 10 ton/acre + 50% of NPK that caused significant improvement in growth, yield and nutrient uptakes of corn in the two governorates during the two constitutive seasons. Results showed that agricultural waste could be composted into value added soil amendment to enhance efficiency of chemical fertilizer. Composting of agricultural waste could also reduce the chemical fertilizers potential hazard to the environment.

Keywords: agricultural waste, compost, chemical fertilizers, corn production, environment

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Authors: Habes Sameh, Bettahar Asma, Nezli Imad Eddine

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The region of Touggourt is situated in the southern part is Algeria, it receives important quantities of waters, the latter are extracted from the fossil groundwater (the Intercalary Continental and the Terminal Complex). The mineralization of these waters of the Terminal Complex is between 3 and 6,5 g/l and for waters of Intercalary Continental is 1,8 and 8,7 g/l, thus it constitutes an obstacle as for its use. To highlight the origins of this mineralization, we used the hydrochemical tool. So the chemical analyses in our ownership, were treated by means of the software "Statistica", what allowed us to realize an analysis in main components (ACP), the latter showed a competition between sodic or magnesian chlorinated water and calcic bicarbonate water, rich in potassium for the TC, while for the IC, we have a competition between sodic or calcic chlorinated and magnesian water treated with copper sulphate waters. The simulation realized thermodynamics showed a variation of the index of saturation which do not exceed zero, for waters of two aquifer TC and IC, so indicating one under saturation of waters towards minerals, highlighting the influence of the geologic formation in the outcrop on the quality of waters. However, we notice that these waters remain acceptable for the irrigation of plants but must be treated before what are consumed by the human being.

Keywords: ACP, intercalary, continental, mineralization, SI, Terminal Complex

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Authors: Sami Ayad, Mengshan Lee

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The Sustainable Development Goals (SDGs) were designed to be the best possible blueprint to achieve peace, prosperity, and overall, a better and more sustainable future for the Earth and all its people, and such a blueprint is needed more than ever. The SDGs face many hurdles that will prevent them from becoming a reality, one of such hurdles, arguably, is the chemical pollution and unintended chemical impacts generated through the production of various goods and resources that we consume. Chemical Alternatives Assessment has proven to be a viable solution for chemical pollution management in terms of filtering out hazardous chemicals for a greener alternative. However, the current substitution practice lacks crucial quantitative datasets (exposures and life cycle impacts) to ensure no unintended trade-offs occur in the substitution process. A Chemical Life Cycle Alternative Assessment (CLiCAA) framework is proposed as a reliable and replicable alternative to Life Cycle Based Alternative Assessment (LCAA) as it integrates chemical molecular structure analysis and Chemical Life Cycle Collaborative (CLiCC) web-based tool to fill in data gaps that the former frameworks suffer from. The CLiCAA framework consists of a four filtering layers, the first two being mandatory, with the final two being optional assessment and data extrapolation steps. Each layer includes relevant impact categories of each chemical, ranging from human to environmental impacts, that will be assessed and aggregated into unique scores for overall comparable results, with little to no data. A feasibility study will demonstrate the efficiency and accuracy of CLiCAA whilst bridging both cancer potency and exposure limit data, hoping to provide the necessary categorical impact information for every firm possible, especially those disadvantaged in terms of research and resource management.

Keywords: chemical alternative assessment, LCA, LCAA, CLiCC, CLiCAA, chemical substitution framework, cancer potency data, chemical molecular structure analysis

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Authors: Y. M. Aiyesimi, S. O. Abah, G. T. Okedayo

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A general analysis has been developed to study the chemical reaction effects on unsteady MHD double-diffusive free convective flow over a vertical stretching plate. The governing nonlinear partial differential equations have been reduced to the coupled nonlinear ordinary differential equations by the similarity transformations. The resulting equations are solved numerically by using Runge-Kutta shooting technique. The effects of the chemical parameters are examined on the velocity, temperature and concentration profiles.

Keywords: chemical reaction, MHD, double-diffusive, stretching plate

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Authors: Ieva Jokubauskaite, Alvyra Slepetiene, Danute Karcauskiene, Inga Liaudanskiene, Kristina Amaleviciute

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Soil organic carbon (SOC) is the key soil quality and ecological stability indicator, therefore, carbon accumulation in stable forms not only supports and increases the organic matter content in the soil, but also has a positive effect on the quality of soil and the whole ecosystem. Soil liming is one of the most common ways to improve the carbon sequestration in the soil. Determination of the optimum intensity and combinations of liming in order to ensure the optimal carbon quantitative and qualitative parameters is one of the most important tasks of this work. The field experiments were carried out at the Vezaiciai Branch of Lithuanian Research Centre for Agriculture and Forestry (LRCAF) during the 2011–2013 period. The effect of liming with different intensity (at a rate 0.5 every 7 years and 2.0 every 3-4 years) was investigated in the topsoil of acid moraine loam Bathygleyic Dystric Glossic Retisol. Chemical analyses were carried out at the Chemical Research Laboratory of Institute of Agriculture, LRCAF. Soil samples for chemical analyses were taken from the topsoil after harvesting. SOC was determined by the Tyurin method modified by Nikitin, measuring with spectrometer Cary 50 (VARIAN) at 590 nm wavelength using glucose standards. SOC fractional composition was determined by Ponomareva and Plotnikova version of classical Tyurin method. Dissolved organic carbon (DOC) was analyzed using an ion chromatograph SKALAR in water extract at soil-water ratio 1:5. Spectral properties (E4/E6 ratio) of humic acids were determined by measuring the absorbance of humic and fulvic acids solutions at 465 and 665 nm. Our study showed a negative statistically significant effect of periodical liming (at 0.5 and 2.0 liming rates) on SOC content in the soil. The content of SOC was 1.45% in the unlimed treatment, while in periodically limed at 2.0 liming rate every 3–4 years it was approximately by 0.18 percentage points lower. It was revealed that liming significantly decreased the DOC concentration in the soil. The lowest concentration of DOC (0.156 g kg-1) was established in the most intensively limed (2.0 liming rate every 3–4 years) treatment. Soil liming exerted an increase of all humic acids and fulvic acid bounded with calcium fractions content in the topsoil. Soil liming resulted in the accumulation of valuable humic acids. Due to the applied liming, the HR/FR ratio, indicating the quality of humus increased to 1.08 compared with that in unlimed soil (0.81). Intensive soil liming promoted the formation of humic acids in which groups of carboxylic and phenolic compounds predominated. These humic acids are characterized by a higher degree of condensation of aromatic compounds and in this way determine the intensive organic matter humification processes in the soil. The results of this research provide us with the clear information on the characteristics of SOC change, which could be very useful to guide the climate policy and sustainable soil management.

Keywords: acid soil, carbon sequestration, long–term liming, soil organic carbon

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Authors: A. Afroogh, R. Ramazani Omali, N. Hafezi Moghaddas, A. Nohegar

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Burkh anticline is located in Southeast of Zagros fold-thrust belt in the Fars Province. Geometric analyses of the anticline have been carried out to estimate the closure of the Dehram Group in order to evaluate its potential for gas reservoirs. Geometric analyses of the Burkh anticline indicate that the fold geometry is rather similar to that of the detachment folds. Based on the data from the geometric analysis, seven structural cross section the anticlines are drawn and using the cross sections, a structural contour for Dehram Group is constructed. The calculated values for the anticline closure prohibits this structure as it is not an appropriate host to gas reservoirs.

Keywords: Burkh anticline, Zagros fold-thrust belt, geometric analyses, vertical and horizontal closure, Dehram group

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Authors: Azin Nasrollah Zadeh

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A factorial experiment was applied to evaluate the effect of chemical and biological fertilizer on yield, total nitrogen uptake and NHI of rice. Four biological treatments including:(M1:no fertilizer),( M2:10 ton/ha cow dung ),(M3:20 ton/ha cow dung) and (M4:5 ton/ha azolla compost) and four chemical fertilizer treatments including: (S1: no fertilizer),(S2:40 kg N /ha),(S3:60 kg N /ha) and ( S4:80 kg N /ha ) were compared. Results showed that highest rate of yield (3387 kg/ha) and total nitrogen uptake (81.4 kg/ha) were reached the highest value at M4. Among the chemical fertilizers the highest grain yield (3373 kg/ha) and total nitrogen uptake (87.7) belonged to highest nitrogen level (S4).Also biological and chemical fertilizers were no significant on Harvest index (NHI). Interaction effect of chemical × biological fertilizers didn't show significant difference between all parameters except of yield, as the most grain yield were obtained in M4S4. So it can be concluded that using of bioilogical fertilizers at appropriate rate and type, considering plant requirement, may improve grain yield, nitrogen uptake and use efficiency in rice.

Keywords: azolla, fertilizer, nitrogen uptake, rice, yield

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Authors: Volkan Isbuga, Joman M. Mahmood, Ali Firat Cabalar

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This study presents the site response analysis of mica-sand mixtures available in certain parts of the world including Izmir, a highly populated city and located in a seismically active region in western part of Turkey. We performed site response analyses by employing SHAKE, an equivalent linear approach, for the micaceous soil deposits consisting of layers with different amount of mica contents and thicknesses. Dynamic behavior of micaceous sands such as shear modulus reduction and damping ratio curves are input for the ground response analyses. Micaceous sands exhibit a unique dynamic response under a scenario earthquake with a magnitude of Mw=6. Results showed that higher amount of mica caused higher spectral accelerations.

Keywords: micaceous sands, site response, equivalent linear approach, SHAKE

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Authors: H. Merzouka, D. T. Talantikitea, S. Fettouchib, L. Nessarkb

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Recently New nanosized materials studies are in huge expansion worldwide. They play a fundamental role in various industrial applications thanks their unique and functional properties. Moreover, in recent years, a great effort has been made in design and control fabrication of nano-structured semiconductors such as zinc sulphide. In recent years, much attention has been accorded in doped and co-doped ZnS to improve the ZnS films quality. We present in this work preparation and characterization of ZnS and Cu doped ZnS thin films. Nanoparticles ZnS and Cu doped ZnS films are prepared by chemical bath deposition method (CBD), for various dopant concentrations. Thin films are deposed onto commercial microscope glass slides substrates. Thiourea is used as sulfide ion source, zinc acetate as zinc ion source and copper acetate as Cu ion source in alkaline bath at 90 °C. X-ray diffraction (XRD) analyses are carried out at room temperature on films and powders with a powder diffractometer, using CuK radiation. The average grain size obtained from the Debye–Scherrer’s formula is around 10 nm. Films morphology is examined by scanning electron microscopy. IR spectra of representative sample are recorded with the FTIR between 400 and 4000 cm-1. The transmittance is more than 70 % is performed with the UV–VIS spectrometer in the wavelength range 200–800 nm. This value is enhanced by Cu doping.

Keywords: Cu doped ZnS, nanostructured, thin films, CBD, XRD, FTIR

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Authors: Chhaya Sharma, Dushyant Kumar

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The present work deals with the treatment of wastewater generated by paper industry by using aluminium as anode material. The quantitative and qualitative analyses of chloropenolics have been carried out by using primary clarifier effluent with the help of gas chromatography mass spectrometry. Sixteen chlorophenolics compounds have been identified and estimated. Results indicated that among 16 identified compounds, 7 are 100% removed and overall 66% reduction in chorophenolics compounds have been detected. Moreover, during the treatment, the biodegradability index of wastewater significantly increases, along with 70 % reduction in chemical oxygen demand and 99 % in color.

Keywords: aluminium anode, chlorophenolics, electrocoagulation, pollution load, wastewater

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Authors: Muhammad Arif Mahmood, Andrei C. Popescu, Mihai Oane, Diana Chioibascu, Carmen Ristoscu, Ion N. Mihailescu

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Powder flow and temperature distributions are recognized as influencing factors during laser melting deposition (LMD) process, that not only affect the consolidation rate but also characteristics of the deposited layers. Herewith, two simplified analytical models will be presented to simulate the powder flow with the inclusion of powder particles size distribution in Gaussian form, under three powder jet nozzles, and temperature analyses during LMD process. The output of the 1st model will serve as the input in the 2nd model. The models will be validated with experimental data, i.e., weight measurement method for powder particles distribution and infrared imaging for temperature analyses. This study will increase the cost-efficiency of the LMD process by adjustment of the operating parameters for reaching optimal powder debit and energy. This research has received funds under the Marie Sklodowska-Curie grant agreement No. 764935, from the European Union’s Horizon 2020 research and innovation program.

Keywords: laser additive manufacturing, powder particles size distribution in Gaussian form, powder stream distribution, temperature analyses

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Authors: N. Majouri, J. Sghaier, M. El Mankibi

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The history of brick manufacturing in south-west Tunisia dates back 1000 years. Most of the bricks are made at local workshops near to the clay supply site. This experimental study aims at studying and comparing the chemical, mineralogical and physical characterization of ancient and recent clay bricks in south-western Tunisia. This was done by collecting a large sample of clay brick specimens from four sites. There was much variability in the properties. The results revealed that there is a difference of up to 50% between old and new bricks; in chemical composition, mineralogy composition and porosity, which are much lower in recent clay bricks.

Keywords: clay bricks, chemical properties, mineralogical properties, physical properties

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Authors: C. F. Kumru, C. Kocatepe, O. Arikan

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In this study, electric field distribution analyses for three pylon models are carried out by a Finite Element Method (FEM) based software. Analyses are performed in both stationary and time domains to observe instantaneous values along with the effective ones. Considering the results of the study, different line geometries is considerably affecting the magnitude and distribution of electric field although the line voltages are the same. Furthermore, it is observed that maximum values of instantaneous electric field obtained in time domain analysis are quite higher than the effective ones in stationary mode. In consequence, electric field distribution analyses should be individually made for each different line model and the limit exposure values or distances to residential buildings should be defined according to the results obtained.

Keywords: electric field, energy transmission line, finite element method, pylon

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Authors: Om Kalthoum Sallem, Saidakilani, Kamiliya Ounaissa, Abdelmajid Abid

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Introduction and purposes: Olive oil is the main oil used in the Mediterranean diet. Virgin olive oil is valued for its organoleptic and nutritional characteristics and is resistant to oxidation due to its high monounsaturated fatty acid content (MUFAs), and low polyunsaturates (PUFAs) and the presence of natural antioxidants such as phenols, tocopherols and carotenoids. The fatty acid composition, especially the MUFA content, and the natural antioxidants provide advantages for health. The aim of the present study was to examine the impact of method of extraction on the chemical profiles of ‘Chemchali’ olive oil variety, which is cultivated in the city of Gafsa, and to compare it with chetoui and chemchali varieties. Methods: Our study is a qualitative prospective study that deals with ‘Chemchali’ olive oil variety. Analyses were conducted during three months (from December to February) in different oil mills in the city of Gafsa. We have compared ‘Chemchali’ olive oil obtained by continuous method to this obtained by superpress method. Then we have analyzed quality index parameters, including free fatty acid content (FFA), acidity, and UV spectrophotometric characteristics and other physico-chemical data [oxidative stability, ß-carotene, and chlorophyll pigment composition]. Results: Olive oil resulting from super press method compared with continuous method is less acid(0,6120 vs. 0,9760), less oxydazible(K232:2,478 vs. 2,592)(k270:0,216 vs. 0,228), more rich in oleic acid(61,61% vs. 66.99%), less rich in linoleic acid(13,38% vs. 13,98 %), more rich in total chlorophylls pigments (6,22 ppm vs. 3,18 ppm ) and ß-carotene (3,128 mg/kg vs. 1,73 mg/kg). ‘Chemchali’ olive oil showed more equilibrated total content in fatty acids compared with the varieties ’Chemleli’ and ‘Chetoui’. Gafsa’s variety ’Chemlali’ have significantly less saturated and polyunsaturated fatty acids. Whereas it has a higher content in monounsaturated fatty acid C18:2, compared with the two other varieties. Conclusion: The use of super press method had benefic effects on general chemical characteristics of ‘Chemchali’ olive oil, maintaining the highest quality according to the ecocert legal standards. In light of the results obtained in this study, a more detailed study is required to establish whether the differences in the chemical properties of oils are mainly due to agronomic and climate variables or, to the processing employed in oil mills.

Keywords: olive oil, extraction method, fatty acids, chemchali olive oil

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