Juniper online journal material science最新文献

{"title":"Which is the Future for Organic Monolithic Composite Materials for Analytical Applications?","authors":"E. J. Carrasco-Correa","doi":"10.19080/jojms.2020.06.555684","DOIUrl":"https://doi.org/10.19080/jojms.2020.06.555684","url":null,"abstract":"The quest for methodologies which allows the quantification of low amounts of analytes in complicated matrices, the improvement in efficiency and reduction of costs have been a real challenge in the last years. In this sense, the preparation of novel materials in separation and sample preparation have been widely developed. Particularly, the appearance of porous organic polymers in the latest 80s and its more recently combination with other materials from different nature have offer a perfect opportunity to overcome the limitation of conventional silica particles. In this manuscript, a short state-of-the art combined with a viewpoint of the porous organic polymer composites and the possible direction that should be taken in the near future have been considered.","PeriodicalId":87320,"journal":{"name":"Juniper online journal material science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48332718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Promising Metamaterials for Optoelectronics based on Polymer Nanocomposites","authors":"Ushakov Nm","doi":"10.19080/jojms.2020.06.555682","DOIUrl":"https://doi.org/10.19080/jojms.2020.06.555682","url":null,"abstract":", Cu/Cu 2 O (CuO), ZnO, CdS nanoparticles stabilized in low density polyethylene (LDPE) were selected as polymer nanocomposites as objects of study. The studies were carried out both on powder samples and on materials in the form of a film with a thickness of 15-50 microns and plates with a thickness of 400-1000 microns. The synthesis of metal-containing nanocomposites was carried out by the method of high-speed thermal decomposition of solutions of metal-containing compounds. Iron pentacarbonyl was used as starting compounds to obtain iron-containing nanoparticles, and corresponding acetates were used for copper and zinc-containing ones. Obtaining nanomaterials was carried out in a solution-melt of polyethylene in purified mineral oil in an argon atmosphere at the decomposition temperature of the above precursors. The gas feed rate was controlled in such a way as to ensure fast and complete removal of ligands and solvent from the reactor. The calculated amount of the solution containing the precursor was introduced into the melt of high-pressure polyethylene with vigorous stirring. After washing the oil with hexane in a Soxhlett apparatus, the samples were dried in vacuum and stored until studies in air began. The resulting materials were powders whose color depended on the concentration and nature of the nanoparticles. The materials necessary for the study of the mold were made from the materials obtained by hot pressing. samples The basic electrophysical and optical properties of samples with different of nanoparticles nanoparticles in the LDPE the sizes of which depend on the concentration and nature of the The sizes of and zinc containing nanoparticles in the studied were: 1-10nm, 10-25nm and respectively. The results of measuring the passage of direct current through copper-containing nanocomposites at different showed that contact phenomena are clearly at low temperatures. With a further increase in temperature, the resistance of the sample decreases, and the current throughput increases, which reflects the semiconductor nature of the studied nanomaterials. The study of the temperature dependences of the passage of current through copper-containing samples of nanocomposites revealed an interesting feature, which consists in observing the current hysteresis during heating and cooling of the samples. The conductivity, dielectric constant, and dielectric loss tangent of copper-containing nanocomposites were studied, and the concentration dependence of these properties was determined for these materials. With an increase in the concentration of nanoparticles in the polymer matrix, the dielectric constant increases by six times, losses at a frequency of 1 MHz increase by a factor of three, and conductivity increases by almost times. A specific feature of the electrophysical properties of nanocomposites on copper-containing nanoparticles in a in electrical conductivity","PeriodicalId":87320,"journal":{"name":"Juniper online journal material science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46002902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Using Rock Mechanics Concepts in Tectonic settings","authors":"Rwo Kersten","doi":"10.19080/jojms.2020.06.555681","DOIUrl":"https://doi.org/10.19080/jojms.2020.06.555681","url":null,"abstract":"Faulting, folding and subduction zones are the result of forces exceeding the strength of the rock in the earth crust and mantle, hence, if the yield/failure limits can be determined, the maximum value of the acting force is established. The rock strength for various temperatures and stress ratios is defined by the Mohr envelope and accepting that the vertical stress component can either be the minimum or the maximum principal stress, the limits of the maximum or minimum principal stress can be determined. By combining these values with the temperature gradients, thermal models and density variations the yield envelopes are determined and illustrated for a base case, a thermal, collision and subduction model. For verification of the results obtained the yield envelopes are transposed onto pressure temperature values of known metamorphic facies diagrams as well as a comparison between predicted and actual seismicity in subduction zones.","PeriodicalId":87320,"journal":{"name":"Juniper online journal material science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45623689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Composite Recycling Techniques: A Literature Review","authors":"Penghui Wang","doi":"10.19080/jojms.2020.06.555679","DOIUrl":"https://doi.org/10.19080/jojms.2020.06.555679","url":null,"abstract":"Composite materials have gained increased popularity for the manufacture of components and structures in various fields, such as in the aviation industry. However, with the increased use of composite materials, an increased amount of composite material waste is generated [1,2] and new end-of-life (EoL) and disposability issues emerge [3]. For example, at the end of the useful life of an aircraft-as in the case of the Boeing 747 in Figure 1, usable and high-valued parts are sold or reused, while the airframe and the remaining components are disposed in landfills or incinerated [1,3,4]. However, this approach is not sustainable or highly viable for composite-based aircraft structures and components-such as the composite-based Boeing 787 in Figure 2, and presents a wide array of environmental concerns. First, the available landfill space is decreasing, while at the same time its cost is increasing [1] due to increased disposal and end-of-life regulations. Additionally, certain composite materials are classified as hazardous waste due to their high pollution characteristics, and as such cannot be disposed in landfills or incinerated at the end of their useful life without further treatment [3]. Furthermore, by disposing or incinerating composite materials, finite resources are being consumed [5] and valuable materials are destroyed [6].","PeriodicalId":87320,"journal":{"name":"Juniper online journal material science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45485196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular Engineering of DNA-inspired Janus base nanomaterials.","authors":"Wuxia Zhang, Yupeng Chen","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":87320,"journal":{"name":"Juniper online journal material science","volume":"5 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7946152/pdf/nihms-1576404.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25467983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design and Analysis of a Novel CPT System with Soft Ferromagnetic Material Cores and Electromagnetic Resonant Coupling for EVs","authors":"J. Duan, William Weiji Wang","doi":"10.19080/jojms.2019.05.555668","DOIUrl":"https://doi.org/10.19080/jojms.2019.05.555668","url":null,"abstract":"This paper describes a novel contactless power transfer (CPT) system with geometrically improved H-shape ferromagnetic cores and electromagnetically prospective modelling analysis methods for wireless power transmitting (WPT) applications of electric vehicles (EVs). A CPT prototype, using optimized H-shaped magnetic couplers and series-to-series (SS) compensation, is proposed to address and ensure the maximization of system efficiency, power transfer ratings, and air gaps of coupling coils. By focusing on the main factors such as various system operating frequencies, different geometric designs of coils, changeable inductive coupling distances, electromagnetic field performances and actual phase angle deviations when the inductive coupling system tends to be stable with its waveforms, this small-sized H-shape CPT system has been analytically considered and modelled in a finite-element method (FEM) environment, resulting in a maximum system efficiency of 59.5%, a coil transmitting efficiency of 83.8% and a maximum power output of 42.81 kW on the load end when the resonant coupling of CPT system tends to occur within a range of calculated resonant frequencies, with an air gap of 10 mm. Moreover, the system efficiency and coil transmitting efficiency can reach 47.75% and 77.22%, respectively, and the highest RMS real power to load can achieve 31.95 kW with an air gap of 20 mm. Besides, with an air gap of 30mm, this H-shape CPT system is measured to output 20.39-kW RMS power, along with the maximum system efficiency and coil efficiency of 41.78% and 63.23%, respectively. Furthermore, the improvements of flux linkage, magnetic flux density regarding the actual electromagnetic performance produced and the issues on the calculated natural resonant frequencies have been studied by result analysis and comparison of electromagnetic field parameters generated. In addition, the current limitations and further design considerations have been discussed in this paper.","PeriodicalId":87320,"journal":{"name":"Juniper online journal material science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47522349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Composite Materials","authors":"Awham M. Hameed","doi":"10.19080/jojms.2019.05.555664","DOIUrl":"https://doi.org/10.19080/jojms.2019.05.555664","url":null,"abstract":"Composite materials defined as mixtures of two (or more) components; combined physically with each other. One of these components called the reinforcing phase or the discontinuous phase while the other called the matrix or the continuous phase. The final forms of the reinforcing phase component could be particles, or flakes or fibers; while the matrix phase is a multiple; for example, polymer, metal or ceramic. There are so many practical examples of composite systems; such as a concrete reinforced with steel or epoxy resin reinforced with graphite hit fibers and many other examples.","PeriodicalId":87320,"journal":{"name":"Juniper online journal material science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42289451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Conversion of Polymer and Resin Wastes into the Valuable Products","authors":"A. Vedyagin","doi":"10.19080/jojms.2019.05.555660","DOIUrl":"https://doi.org/10.19080/jojms.2019.05.555660","url":null,"abstract":"","PeriodicalId":87320,"journal":{"name":"Juniper online journal material science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45338358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solvent Fractionation of Lignin from Sugarcane Bagasse","authors":"W. F. Tinto","doi":"10.19080/jojms.2018.05.555658","DOIUrl":"https://doi.org/10.19080/jojms.2018.05.555658","url":null,"abstract":"The objective of this work was to examine lignin fractionation from sugarcane bagasse using three organic solvents. Lignin derived from lignocellulosic sources such as sugarcane bagasse can be used as sources of low molecular weight aromatic compounds. These compounds can be used as chemical building blocks for the production of high value materials. In this work, organic solvent fractionation using methanol, ethanol and acetone were used to fractionate lignin from sugarcane bagasse. It was demonstrated that among these solvents the acetone and ethanol fractionated higher concentrations of lignin from bagasse. This indicated that these two solvents can be used to obtain lignin components from which low molecular weight aromatic components can be derived that have various applications.","PeriodicalId":87320,"journal":{"name":"Juniper online journal material science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43756322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Response of Mungbean Yield and Yield Components into Various Levels of Phosphorous","authors":"J. Ahmad","doi":"10.19080/jojms.2018.05.555655","DOIUrl":"https://doi.org/10.19080/jojms.2018.05.555655","url":null,"abstract":"This study was aimed to help the farmers to decide the optimum dose of phosphorous fertilizer whether they can use the recommended dose for achieving higher yield of mungbean in agro climatic condition of Peshawar. Farmers need to know what fertilizer application rate they should use under their conditions for adequate productivity. To obtain these objectives an experiment was carried out at Agricultural Research Farm Agricultural University Peshawar during 2017. Five levels of P i.e. 0, 20, 40, 60 and 80 kg ha-1 on mung bean were studied in the experiment. Mungbean cultivar NM-92 was sown in the experiment. Phosphorus application was significant for all the parameters. Plots treated with 60 kg P ha-1 produced maximum nodules plant-1 (25), pods plant-1 (22), seeds pod-1 (11), 1000 grains weight (40.2 g), biological yield (4595 kg ha-1), grain yield (1139 kg ha-1) and harvest index (28.6 %) as compared with control plots but seeds pod-1, 1000 grains weight, grain yield and harvest index was statistically at par when plots treated with 80 kg P ha-1. Increased in fertilizer has increased these parameters up to some extent and a decreasing trend was observed beyond 40 kg ha-1 phosphorous application. Regarding yield 80% variations was accorded by the phosphorous application. Based on the above facts it is concluded that mungbean cultivar NM-92 applied with 60 kg P ha-1 was better in terms of yield and yield components and may be recommended for cultivation in agro-climatic condition of Peshawar.","PeriodicalId":87320,"journal":{"name":"Juniper online journal material science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43064928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}