IOP Conf. Series: Materials Science and Engineering最新文献

{"title":"Optical luminescence studies of diffusion times at the potassium ethyl xanthate adsorption layer on the surface of sphalerite minerals","authors":"R. Todoran, D. Todoran, E. Anitas, Z. Szakács","doi":"10.1088/1757-899X/144/1/012012","DOIUrl":"https://doi.org/10.1088/1757-899X/144/1/012012","url":null,"abstract":"We propose reflectance measurements as a method for the evaluation of the kinetics of adsorption processes, to compute the diffusion times of the adsorption products at the thin layers formed at the sphalerite natural mineral-potassium ethyl xanthate solution interface. The method is based on the intensity measurement of the reflected monochromatic radiation obtained from the mineral-xanthate thin layer as a function of time. These determinations were made at the thin layer formed between the sphalerite or activated sphalerite natural minerals with potassium ethyl xanthate, for different solutions concentrations and pH values at constant temperature. Diffusion times of desorbed molecular species into the liquid bring important information about the global kinetics of the ions in this phase during adsorption processes at interfaces. Analysing the time dependence of this parameter one concluded on the diffusion properties of the xanthate molecule in the solution depending on its concentration and pH, knowing that at the initial time these molecules had a uniform spread. This method enabled us to determine that, in time interval of approximately 35 minutes to achieve dynamic equilibrium in the formation of the interface layer, one had three different kinetic behaviours of our systems. In the first 5-8 min one had highly adsorbent character, the state of equilibrium is followed by low adsorbent properties. Gaining information on the adsorption kinetics in the case of xanthate on mineral surface leads to the optimization of the industrial froth flotation process.","PeriodicalId":359151,"journal":{"name":"IOP Conf. Series: Materials Science and Engineering","volume":"101 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133222410","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":"A numerical solution to the cattaneo-mindlin problem for viscoelastic materials","authors":"S. Spinu, D. Cerlinca","doi":"10.1088/1757-899X/145/4/042033","DOIUrl":"https://doi.org/10.1088/1757-899X/145/4/042033","url":null,"abstract":"The problem of the frictional mechanical contact with slip and stick, also referred to as the Cattaneo-Mindlin problem, is an important topic in engineering, with applications in the modeling of particle-flow simulations or in the study of contact between rough surfaces. In the frame of Linear Theory of Elasticity, accurate description of the slip-stick contact can only be achieved numerically, due to mutual interaction between normal and shear contact tractions. Additional difficulties arise when considering a viscoelastic constitutive law, as the mechanical response of the contacting materials depends explicitly on time. To overcome this obstacle, an existing algorithm for the purely elastic slip-stick contact is coupled with a semi-analytical method for viscoelastic displacement computation. The main advantage of this approach is that the contact model can be divided in subunits having the same structure as that of the purely elastic frictionless contact model, for which a well-established solution is readily available. In each time step, the contact solver assesses the contact area, the pressure distribution, the stick area and the shear tractions that satisfy the contact compatibility conditions and the static force equilibrium in both normal and tangential directions. A temporal discretization of the simulation windows assures that the memory effect, specific to both viscoelasticity and friction as a path-dependent processes, is properly replicated.","PeriodicalId":359151,"journal":{"name":"IOP Conf. Series: Materials Science and Engineering","volume":"145 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129357760","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":"Knowledge portal for Six Sigma DMAIC process","authors":"N. Thanh-Dat, K. Claudiu, R. Zobia, L. Lobonț","doi":"10.1088/1757-899X/145/6/062011","DOIUrl":"https://doi.org/10.1088/1757-899X/145/6/062011","url":null,"abstract":"Knowledge plays a crucial role in success of DMAIC (Define, Measure, Analysis, Improve, and Control) execution. It is therefore necessary to share and renew the knowledge. Yet, one problem arising is how to create a place where knowledge are collected and shared effectively. We believe that Knowledge Portal (KP) is an important solution for the problem. In this article, the works concerning with requirements and functionalities for KP are first reviewed. Afterwards, a procedure with necessary tools to develop and implement a KP for DMAIC (KPD) is proposed. Particularly, KPD is built on the basis of free and open-source content and learning management systems, and Ontology Engineering. In order to structure and store knowledge, tools such as Protégé, OWL, as well as OWL-RDF Parsers are used. A Knowledge Reasoner module is developed in PHP language, ARC2, MySQL and SPARQL endpoint for the purpose of querying and inferring knowledge available from Ontologies. In order to validate the availability of the procedure, a KPD is built with the proposed functionalities and tools. The authors find that the KPD benefits an organization in constructing Web sites by itself with simple steps of implementation and low initial costs. It creates a space of knowledge exchange and supports effectively collecting DMAIC reports as well as sharing knowledge created. The authors’ evaluation result shows that DMAIC knowledge is found exactly with a high success rate and a good level of response time of queries.","PeriodicalId":359151,"journal":{"name":"IOP Conf. Series: Materials Science and Engineering","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127173206","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":"Recent researches concerning the obtaining of functional textiles based on conductive yarns","authors":"A. Leon, L. Manea, L. Hristian","doi":"10.1088/1757-899X/145/3/032005","DOIUrl":"https://doi.org/10.1088/1757-899X/145/3/032005","url":null,"abstract":"Modem textile industry is influenced both by consumers' lifestyle and by novel materials. Functional textiles can be included into the group of technical textiles. The functional activity can be shortly interpreted as \"sense - react - adapt\" to the environment while traditional materials meet only passive protective role, a barrier between body and environment. Functional materials cross the conventional limits because they are designed for specific performances, being part of domains as: telemedicine, medicine, aeronautics, biotechnology, nanotechnology, protective clothes, sportswear, etc. This paper highlights the most recent developments in the field of using conductive yarns for obtaining functional textiles. Conductive fabrics can be done by incorporating into the textile structure the conductive fibers / yarns. The technologies differ from embroidering, sewing, weaving, knitting to braiding and obtaining nonwovens. The conductive fabrics production has a quickly growth because it is a high demand for these textiles used for data transfer in clothing, monitoring vital signs, germ-free garments, brain-computer interface, etc. Nowadays it is of high interest surface treatments of fibers/yarns which can be considered as a novel kind of textile finishing. There are presented some researches related to obtaining conductive yarns by coating PET and PP yarns with PANi conductive polymer.","PeriodicalId":359151,"journal":{"name":"IOP Conf. Series: Materials Science and Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129909552","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":"The comparison of predictive scheduling algorithms for different sizes of job shop scheduling problems","authors":"I. Paprocka, W. Kempa, C. Grabowik, K. Kalinowski, D. Krenczyk","doi":"10.1088/1757-899X/145/4/042019","DOIUrl":"https://doi.org/10.1088/1757-899X/145/4/042019","url":null,"abstract":"In the paper a survey of predictive and reactive scheduling methods is done in order to evaluate how the ability of prediction of reliability characteristics influences over robustness criteria. The most important reliability characteristics are: Mean Time to Failure, Mean Time of Repair. Survey analysis is done for a job shop scheduling problem. The paper answers the question: what method generates robust schedules in the case of a bottleneck failure occurrence before, at the beginning of planned maintenance actions or after planned maintenance actions? Efficiency of predictive schedules is evaluated using criteria: makespan, total tardiness, flow time, idle time. Efficiency of reactive schedules is evaluated using: solution robustness criterion and quality robustness criterion. This paper is the continuation of the research conducted in the paper [1], where the survey of predictive and reactive scheduling methods is done only for small size scheduling problems.","PeriodicalId":359151,"journal":{"name":"IOP Conf. Series: Materials Science and Engineering","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129751005","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":"Contributions regarding chemical composition variation in ultrasonic field overlaying welding","authors":"G. Amza, V. Petrescu, D. Niṭoi, C. Amza, A. Dimitrescu, Z. Apostolescu","doi":"10.1088/1757-899X/145/7/072008","DOIUrl":"https://doi.org/10.1088/1757-899X/145/7/072008","url":null,"abstract":"Paper presents a new reconditioning method based on ultrasonic field and analyses the modificated structure composition in three zone: filler material, thermal influenced zone, and base material. Also, chemical composition variation as a result of ultrasonic wave influence is studied besides the ultrasonic wave influence on dilution process.","PeriodicalId":359151,"journal":{"name":"IOP Conf. Series: Materials Science and Engineering","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123132335","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":"The dynamics of the fungal aerospores Alternaria sp. and Cladosporium sp. in Parisian atmospheric air, in France","authors":"V. M. Brezoczki","doi":"10.1088/1757-899X/144/1/012003","DOIUrl":"https://doi.org/10.1088/1757-899X/144/1/012003","url":null,"abstract":"The bioallergens occurring naturally in the atmospheric air are microorganisms, pollen grains, plant seeds, leaf and stem scrap, or their protein molecules. The presence of various airborne fungal spores determines a high allergenic potential for public health. This effect is due to the high number of produced spores, which under favourable meteorological conditions (dry weather and wind) reach the surrounding air. This paper traces the dynamics of two types of fungi, Alternaria sp and Cladosporium sp, fungi which can be found outdoors, in the surrounding air, as well as indoors, inside houses (especially the conidia of Cladosporium sp). The effects of these fungal spores on human health are varies, ranging from seasonal allergies (hay fever, rhinitis, sinusitis etc.) to sever afflictions of the respiratory system, onset of asthma, disfunctionalities of the nervous systems, of the immune system, zymoses etc. The monitoring of the dynamics of the aerospores Alternaria sp and Cladosporium sp was carried out between 2010 and 2013, over a period of 42 weeks during one calendar year, from February to the end of September, in the surrounding air in the French capital, Paris. The regional and global climate and meteorological conditions are directly involved in the occurrence and development of fungi colonies, the transportation and dispersion of fungal spores in the atmospheric air, as well as in the creation of the environment required for the interaction of chemical and biological components in the air. Knowledge of the dynamics of the studied fungal aerospores, coupled with climate and meteorological changes, offers a series of information on the magnitude of the allergenic potential these airborne spores can determine. Legal regulations in this domain set the allergen risk threshold for the Alternaria sp aerospores at 3500 ÷ 7000 spores/m3 air/week, and for the Cladosporium sp aerospores at 56,000 spores/m3 air/week. Besides these regulations there exist a series of health, social and individual recommendations meant to considerably reduce or even prevent exposure to aerobiological pollution.","PeriodicalId":359151,"journal":{"name":"IOP Conf. Series: Materials Science and Engineering","volume":"296 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120881753","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":"The influence of milling-burnishing successive and simultaneous processes on the surface roughness","authors":"C. Grigoras, G. Brabie, B. Chirita","doi":"10.1088/1757-899X/145/2/022010","DOIUrl":"https://doi.org/10.1088/1757-899X/145/2/022010","url":null,"abstract":"The present techniques do not offer the possibility for milling and burnishing at the same time. The novelty of this study is the development of a new tool and tool holder that allows this processes to take place simultaneous. Magnesium alloys have a wide range of usages in industry; in the past years they seem to be a promising solution to classic implants. Improvements in fatigue and tensile strength need to be made. Heat treatments are difficult to implement, so the solution is a mechanical treatment. The burnishing process offers very good results, but it has difficulties in simultaneous machining with the milling process. Thereby a hydraulic roller burnishing tool and a special tool holder was manufactured to solve this issue. The combined process was carried out on a CNC milling machine. This study seeks to highlight the influence of the milling-burnishing process parameter on the surface roughness in the case of magnesium alloy AZ31B-F. Parameters like speed and feed of cut, burnishing pressure and depth where taken into consideration. It was noted that with the increase of the feed, speed, pressure and depth of burnishing the general percentage improvement of the surface roughness was higher.","PeriodicalId":359151,"journal":{"name":"IOP Conf. Series: Materials Science and Engineering","volume":"117 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130722655","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":"An artificial vision solution for reusing discarded parts resulted after a manufacturing process","authors":"V. Cohal, A. Cohal","doi":"10.1088/1757-899X/145/2/022040","DOIUrl":"https://doi.org/10.1088/1757-899X/145/2/022040","url":null,"abstract":"The profit of a factory can be improved by reusing the discarded components produced. This paper is based on the case of a manufacturing process where rectangular metallic sheets of different sizes are produced. Using an artificial vision system, the shapes and the sizes of the produced parts can be determined. Those sheets which do not respect the requirements imposed are labeled as discarded. Instead of throwing these parts, a decision algorithm can analyze if another metallic sheet with smaller dimensions can be obtained from these. Two methods of decision are presented in this paper, considering the restriction that the sides of the new sheet has to be parallel with the axis of the coordinate system. The coordinates of each new part obtained from a discarded sheet are computed in order to be delivered to a milling machine. Details about implementing these algorithms (image processing and decision respectively) in the MATLAB environment using Image Processing Toolbox are given.","PeriodicalId":359151,"journal":{"name":"IOP Conf. Series: Materials Science and Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131104171","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":"A short overview of upper limb rehabilitation devices","authors":"S. Macovei, I. Doroftei","doi":"10.1088/1757-899X/145/5/052014","DOIUrl":"https://doi.org/10.1088/1757-899X/145/5/052014","url":null,"abstract":"As some studies show, the number of people over 65 years old increases constantly, leading to the need of solution to provide services regarding patient mobility. Diseases, accidents and neurologic problems affect hundreds of people every day, causing pain and lost of motor functions. The ability of using the upper limb is indispensable for a human being in everyday activities, making easy tasks like drinking a glass of water a real challenge. We can agree that physiotherapy promotes recovery, but not at an optimal level, due to limited financial and human resources. Hence, the need of robot-assisted rehabilitation emerges. A robot for upper-limb exercises should have a design that can accurately control interaction forces and progressively adapt assistance to the patients’ abilities and also to record the patient's motion and evolution. In this paper a short overview of upper limb rehabilitation devices is presented. Our goal is to find the shortcomings of the current developed devices in terms of utility, ease of use and costs, for future development of a mechatronic system for upper limb rehabilitation.","PeriodicalId":359151,"journal":{"name":"IOP Conf. Series: Materials Science and Engineering","volume":"200 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114103046","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}