Search results for: modified montmorillonite

Authors: G. Valentis, Q. Berthelot

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Nowadays the trend to develop ever more intelligent and autonomous systems often takes its inspiration in the living beings on Earth. Some simple isolated systems are able, once brought together, to form a strong and reliable system. When trying to adapt the idea to man-made systems it is not possible to include in their program everything the system may encounter during its life cycle. It is, thus, necessary to make the system able to take decisions based on other criteria such as its past experience, i.e. to make the system learn on its own. However, at some point the acquired knowledge depends also on environment. So the question is: if system environment is modified, how could the system respond to it quickly and appropriately enough? Here, starting from reinforcement learning to rate its decisions, and using adaptive learning algorithms for gain and loss reward, the system is made able to respond to changing environment and to adapt its knowledge as time passes. Application is made to a robot finding an exit in a labyrinth.

Keywords: reinforcement learning, neural network, autonomous systems, adaptive learning, changing environment

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Authors: Yangsu Kwon, Hyo-Gyoung Kwak

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Nonlinear tendon constitutive model for nonlinear analysis of pre-stressed concrete structures are presented. Since the post-cracking behavior of concrete structures, in which bonded reinforcements such as tendons and/or reinforcing steels are embedded, depends on many influencing factors(the tensile strength of concrete, anchorage length of reinforcements, concrete cover, and steel spacing) that are deeply related to the bond characteristics between concrete and reinforcements, consideration of the tension stiffening effect on the basis of the bond-slip mechanism is necessary to evaluate ultimate resisting capacity of structures. In this paper, an improved tendon model, which considering the slip effect between concrete and tendon, and effect of tension stiffening, is suggested. The validity of the proposed models is established by comparing between the analytical results and experimental results in pre-stressed concrete beams.

Keywords: bond-slip, prestressed concrete, tendon, ultimate strength

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Authors: Maciej Szeląg, Stanisław Fic

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The impact of elevated temperatures on the construction materials manifests in change of their physical and mechanical characteristics. Stresses and thermal deformations that occur inside the volume of the material cause its progressive degradation as temperature increase. Finally, the reactions and transformations of multiphase structure of cementitious composite cause its complete destruction. A particularly dangerous phenomenon is the impact of thermal shock – a sudden high temperature load. The thermal shock leads to a high value of the temperature gradient between the outer surface and the interior of the element in a relatively short time. The result of mentioned above process is the formation of the cracks and scratches on the material’s surface and inside the material. The article describes the use of computer image analysis techniques to identify and assess the structure of the cluster cracks on the surfaces of modified cement pastes, caused by thermal shock. Four series of specimens were tested. Two Portland cements were used (CEM I 42.5R and CEM I 52,5R). In addition, two of the series contained metakaolinite as a replacement for 10% of the cement content. Samples in each series were made in combination of three w/b (water/binder) indicators of respectively 0.4; 0.5; 0.6. Surface cracks of the samples were created by a sudden temperature load at 200°C for 4 hours. Images of the cracked surfaces were obtained via scanning at 1200 DPI; digital processing and measurements were performed using ImageJ v. 1.46r software. In order to examine the cracked surface of the cement paste as a system of closed clusters – the dispersal systems theory was used to describe the structure of cement paste. Water is used as the dispersing phase, and the binder is used as the dispersed phase – which is the initial stage of cement paste structure creation. A cluster itself is considered to be the area on the specimen surface that is limited by cracks (created by sudden temperature loading) or by the edge of the sample. To describe the structure of cracks two stereological parameters were proposed: A ̅ – the cluster average area, L ̅ – the cluster average perimeter. The goal of this study was to compare the investigated stereological parameters with the mechanical properties of the tested specimens. Compressive and tensile strength testes were carried out according to EN standards. The method used in the study allowed the quantitative determination of defects occurring in the examined modified cement pastes surfaces. Based on the results, it was found that the nature of the cracks depends mainly on the physical parameters of the cement and the intermolecular interactions on the dispersal environment. Additionally, it was noted that the A ̅/L ̅ relation of created clusters can be described as one function for all tested samples. This fact testifies about the constant geometry of the thermal cracks regardless of the presence of metakaolinite, the type of cement and the w/b ratio.

Keywords: cement paste, cluster cracks, elevated temperature, image analysis, metakaolinite, stereological parameters

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Authors: Sidra Saleemi, Arsalan Khan, Urooj Baig, Tahir Jamil

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In this research, it was examined that some residual amount of bleaching chemicals left in the liquor, this amount is more in Batch-wise process as compared to continuous process. These chemicals can be recovered and reused for bleaching by adding more quantity of fresh bleaching chemicals and water, this quantity will be required to balance the recipe for fabric. This liquor is recovered and samples were bleached with different modified recipe of liquor for both processes i.e. Batch-wise and continuous process. Every time good results were achieved with negligible variation in the quality parameter between the fabric bleached with fresh liquor and the fabric bleached with Recovered Liquor. Additionally, samples were dyed, and found that dyeing can be done easily on samples bleached with recover liquor.

Keywords: bleaching process, hydrogen peroxide, sodium hydroxide, liquor recovery

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Authors: El H. Bouziani, H. A. Reguieg Yssaad

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The phytotoxicity of heavy metals can be expressed on roots and visible part of plants and is characterized by molecular and metabolic answers at various levels of organization of the whole plant. The present study was undertaken on two varieties of broad bean Vicia faba (Sidi Aïch and Super Aguadulce). The device was mounted on a substrate prepared by mixing sand, soil and compost, the substrate was artificially contaminated with three doses of lead nitrate [Pb(NO3)2] 0, 500 and 1000 ppm. Our objective is to follow the behavior of plant opposite the stress by evaluating the physiological parameters. The results reveal a reduction in the parameters of the productivity (chlorophyll and proteins production) with an increase in the osmoregulators (soluble sugars and proline).These results show that the production of broad bean is strongly modified by the disturbance of its internal physiology under lead exposure.

Keywords: broad bean, lead, stress, physiological parameters, phytotoxicity

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Authors: Burak Yigit Katanalp, Murat Tastan, Perviz Ahmedzade, çIgdem Canbay Turkyilmaz, Emrah Turkyilmaz

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This study evaluated the mechanical and rheological performance of fly ash-based geopolymer at high temperatures. A series of laboratory tests were conducted on neat bitumen and three modified bitumen samples, which incorporated fly ash-based geopolymer at various percentages. Low-calcium fly ash was used as the alumina-silica source. The dynamic shear rheometer and rotational viscometer were employed to determine high-temperature properties, while conventional tests such as penetration and softening point were used to evaluate the physical properties of bitumen. The short-term aging resistance of the samples was assessed using the rolling thin film oven. The results show that geopolymer has a compromising effect on bitumen properties, with improved stiffness, enhanced mechanical strength, and increased thermal susceptibility of the asphalt binder.

Keywords: bitumen, geopolymer, modification, dynamic mechanical analysis

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Authors: Jedli Hedi, Hedfi Hachem, Abdessalem Jbara, Slimi Khalifa

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Natural and modified clay were used as an adsorbent for CO2 capture. Sample of clay was subjected to acid treatments to improve their textural properties, namely, its surface area and pore volume. The modifications were carried out by heating the clays at 120 °C and then by acid treatment with 3M sulphuric acid solution at boiling temperature for 10 h. The CO2 adsorption capacities of the acid-treated clay were performed out in a batch reactor. It was found that the clay sample treated with 3M H2SO4 exhibited the highest Brunauer–Emmett–Teller (BET) surface area (16.29–24.68 m2/g) and pore volume (0.056–0.064 cm3/g). After the acid treatment, the CO2 adsorption capacity of clay increased. The CO2 adsorption capacity of clay increased after the acid treatment. The CO2 adsorption by clay, were characterized by SEM, FTIR, ATD-ATG and BET method. For describing the phenomenon of CO2 adsorption for these materials, the adsorption isotherms were modeled using the Freundlich and Langmuir models. CO2 adsorption isotherm was found attributable to physical adsorption.

Keywords: clay, acid treatment, CO2 capture, adsorption mechanism

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Authors: Hyun-Kyu Cho, Jun-Su Kim, Choon-Geun Huh, Geon Lee Young-Chul Park

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In this study, the relationship between flow properties and fluid projection distance look into connection for shape variations of foam monitor. A numerical analysis technique for fluid analysis of a foam monitor was developed for the prediction. Shape of foam monitor the flow path of fluid flow according to the shape, The fluid losses were calculated from flow analysis result.. The modified model used the length increase model of the flow path, and straight line of the model. Inlet pressure was 7 [bar] and external was atmosphere codition. am. The results showed that the length increase model of the flow path and straight line of the model was improved in the nozzle projection distance.

Keywords: injection performance, finite element method, foam monitor, Projection distance

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Authors: Muhammad Danish Khan, Imran Naeem, Mudassar Imran

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In this article, we study time-space Fractional Advection-Dispersion (FADE) equation and time-space Fractional Whitham-Broer-Kaup (FWBK) equation that have a significant role in hydrology. We introduce suitable transformations to convert fractional order derivatives to integer order derivatives and as a result these equations transform into Partial Differential Equations (PDEs). Then the Lie symmetries and corresponding optimal systems of the resulting PDEs are derived. The symmetry reductions and exact independent solutions based on optimal system are investigated which constitute the exact solutions of original fractional differential equations.

Keywords: modified Riemann-Liouville fractional derivative, lie-symmetries, optimal system, invariant solutions

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Authors: T. O Babarinde, F. A Oyawale, O. S Ohunakin, R. O Ohunakin, R. O Leramo D.S Adelekan

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This paper presents an experimental study of R600a, environment-friendly refrigerants with low global warming potential (GWP), zero ozone depletion potential (ODP), as a substitute for R134a in domestic refrigerator. A refrigerator designed to work with R134a was used for this experiment, the capillary for this experiment was not varied at anytime during the experiment. 40, 60, 80g, charge of R600a were tested against 100 g of R134a under the designed capillary length of the refrigerator, and the performance using R600a was evaluated and compared with its performance when R134a was used. The results obtained showed that the design temperature and pull-down time set by International Standard Organisation (ISO) for small refrigerator was achieved using both 80g of R600a and 100g of R134a but R134a has earlier pulled down time than using R600a. The average coefficient of performance (COP) obtained using R600a is 17.7% higher than that of R134a while the average power consumption is 42.5 % lower than R134a, which shows that R600a can be used as replacement for R134a in domestic refrigerator without necessarily need to modified the capillary.

Keywords: domestic refrigerator, experimental, R600a, R134a

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Authors: Badr M. Alshammari, T. Guesmi

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This study presents a modified version of the artificial bee colony (ABC) algorithm by including a local search technique for solving the non-convex economic power dispatch problem. The local search step is incorporated at the end of each iteration. Total system losses, valve-point loading effects and prohibited operating zones have been incorporated in the problem formulation. Thus, the problem becomes highly nonlinear and with discontinuous objective function. The proposed technique is validated using an IEEE benchmark system with ten thermal units. Simulation results demonstrate that the proposed optimization algorithm has better convergence characteristics in comparison with the original ABC algorithm.

Keywords: economic power dispatch, artificial bee colony, valve-point loading effects, prohibited operating zones

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Authors: Safia Hasan Varachhia, Neela Badrie, Marsha Singh

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Genetic modification of food is an innovative technology that offers a host of benefits and advantages to consumers. Consumer attitudes towards GM food and GM technologies can be identified a major determinant in conditioning market force and encouraging policy makers and regulators to recognize the significance of consumer influence on the market. This study aimed to investigate and evaluate the extent of consumer awareness, knowledge, perception and acceptance of GM foods and its associated health risks and benefit in Trinidad and Tobago, West Indies. The specific objectives of this study were to (determine consumer awareness to GM foods, ascertain their perspectives on health and safety risks and ethical issues associated with GM foods and determine whether labeling of GM foods and ingredients will influence consumers’ willingness to purchase GM foods. A survey comprising of a questionnaire consisting of 40 questions, both open-ended and close-ended was administered to 240 shoppers in small, medium and large-scale supermarkets throughout Trinidad between April-May, 2015 using convenience sampling. This survey investigated consumer awareness, knowledge, perception and acceptance of GM foods and its associated health risks/benefits. The data was analyzed using SPSS 19.0 and Minitab 16.0. One-way ANOVA investigated the effects categories of supermarkets and knowledge scores on shoppers’ awareness, knowledge, perception and acceptance of GM foods. Linear Regression tested whether demographic variables (category of supermarket, age of consumer, level of were useful predictors of consumer’s knowledge of GM foods). More than half of respondents (64.3%) were aware of GM foods and GM technologies, 28.3% of consumers indicated the presence of GM foods in local supermarkets and 47.1% claimed to be knowledgeable of GM foods. Furthermore, significant associations (P < 0.05) were observed between demographic variables (age, income, and education), and consumer knowledge of GM foods. Also, significant differences (P < 0.05) were observed between demographic variables (education, gender, and income) and consumer knowledge of GM foods. In addition, age, education, gender and income (P < 0.05) were useful predictors of consumer knowledge of GM foods. There was a contradiction as whilst 35% of consumers considered GM foods safe for consumption, 70% of consumers were wary of the unknown health risks of GM foods. About two-thirds of respondents (67.5%) considered the creation of GM foods morally wrong and unethical. Regarding GM food labeling preferences, 88% of consumers preferred mandatory labeling of GM foods and 67% of consumers specified that any food product containing a trace of GM food ingredients required mandatory GM labeling. Also, despite the declaration of GM food ingredients on food labels and the reassurance of its safety for consumption by food safety and regulatory institutions, the majority of consumers (76.1%) still preferred conventionally produced foods over GM foods. The study revealed the need to inform shoppers of the presence of GM foods and technologies, present the scientific evidence as to the benefits and risks and the need for a policy on labeling so that informed choices could be taken.

Keywords: genetically modified foods, income, labeling consumer awareness, ingredients, morality and ethics, policy

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Authors: Mohammad D. H. Beg, John O. Akindoyo, Suriati Ghazali, Abdullah A. Mamun

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In this study, composites were fabricated from oil palm empty fruit bunch fiber and poly(lactic) acid by extrusion followed by injection moulding. Surface of the fiber was pre-treated by ultrasound in an alkali medium and treatment efficiency was investigated by scanning electron microscopy (SEM) analysis and Fourier transforms infrared spectrometer (FTIR). Effect of fiber treatment on composite was characterized by tensile strength (TS), tensile modulus (TM) and impact strength (IS). Furthermore, biostrong impact modifier was incorporated into the treated fiber composite to improve its impact properties. Mechanical testing showed an improvement of up to 23.5% and 33.6% respectively for TS and TM of treated fiber composite above untreated fiber composite. On the other hand incorporation of impact modifier led to enhancement of about 20% above the initial IS of the treated fiber composite.

Keywords: fiber treatment, impact modifier, natural fibers, ultrasound

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Authors: Jeff A. Tysinger, Dawn P. Tysinger

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There has been considerable growth in online learning. Researchers continue to explore the impact various methods of delivery. Podcasting is a popular method for sharing information. The purpose of this study was to examine the impact of student motivation and the perception of the acquisition of knowledge in an online environment of a skill-based class. 25 students in a school psychology graduate class completed a pretest and posttest examining podcast use and familiarity. In addition, at the completion of the course they were administered a modified version of the Instructional Materials Motivation Survey. The four subscales were examined (attention, relevance, confidence, and satisfaction). Results indicated that students are motivated, they perceive podcasts as positive instructional tools, and students are successful in acquiring the needed information. Additional benefits of using podcasts and recommendations in school psychology training are discussed.

Keywords: motivation, online learning, pedagogy, podcast

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Authors: Rukhsana Shaheen, Tahira Ifraq

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Interest based transactions led the advent of Islamic banking. In order to provide an alternative to Interest based banking, financial transactions found in classical books of fiqh were employed. Musharakah, Mudarabah, Murabahah Salam, Ijara, and some other modes were adopted. These modes were modified so that they can be adopted for banking and satisfy the needs of customers. Since the inception of Islamic banking, these modes are being used and with the passage of time, are being molded and experimented with to cater different kinds of customers and requirements. Human efforts cannot be errorless. These modes too bear legal defects which need an in-depth scrutiny and refinement. The aim of this paper is to dig the basis and rulings of these modes in classical books of fiqh and analyze its modification and adoption in Islamic banking and the legal defects that these modes are bearing. Paper will prove itself fruitful by providing remedies for the legal defects.

Keywords: financial instruments, legal defects, remedies, Islamic banking

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Authors: Shiwei Deng, Yang Bao

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In this paper, we present a model-based regression test suite reducing approach that uses EFSM model dependence analysis and probability-driven greedy algorithm to reduce software regression test suites. The approach automatically identifies the difference between the original model and the modified model as a set of elementary model modifications. The EFSM dependence analysis is performed for each elementary modification to reduce the regression test suite, and then the probability-driven greedy algorithm is adopted to select the minimum set of test cases from the reduced regression test suite that cover all interaction patterns. Our initial experience shows that the approach may significantly reduce the size of regression test suites.

Keywords: dependence analysis, EFSM model, greedy algorithm, regression test

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Authors: Mario Gómez, José Carlos Rodríguez

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This paper analyzes innovation trends in South Korea by means of the number of patent applications filed by residents and nonresidents during the period 1965 to 2012. Making use of patent data released by the World Intellectual Property Organization (WIPO), we search for the presence of multiple structural changes in patent application series in this country. These changes may suggest that firms’ innovative activity has been modified as a result of implementing some science, technology and innovation (STI) policies. Accordingly, the new regulations implemented in this country in the last decades have influenced its innovative activity. The question conducting this research is thus how STI policies in South Korea have influenced its innovation activity. The results confirm the existence of multiple structural changes in the series of patent applications resulting from alternative STI policies implemented during these years.

Keywords: econometric methods, innovation activity, Korea, patent applications, science, technology and innovation policy, STI

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Authors: Illyas Isa, Siti Nur Akmar Mohd Yazid, Norhayati Hashim

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We report a simple, green and cost effective synthesis of graphene via chemical reduction of graphene oxide in alkaline aqueous solution. Extensive characterizations have been studied to confirm the formation of graphene in sodium carbonate solution. Cyclic voltammetry was used to study the electrochemical properties of the prepared graphene-modified glassy carbon electrode using potassium ferricyanide as a redox probe. Based on the result, with the addition of graphene to the glassy carbon electrode the current flow increases and the peak also broadens as compared to graphite and graphene oxide. This method is fast, cost effective, and green as nontoxic solvents are used which will not result in contamination of the products. Thus, this method can serve for the preparation of graphene which can be effectively used in sensors, electronic devices and supercapacitors.

Keywords: chemical reduction, electrochemical, graphene, green synthesis

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Authors: I. A. Simsek, S. N. Dogan, A. S. Kipcak, E. Morodor Derun, N. Tugrul

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In this study, the drying characteristics of shrimp are studied by using the traditional drying method of oven. Drying temperatures are selected between 60-80°C. Obtained experimental drying results are applied to eleven mathematical models of Alibas, Aghbashlo et al., Henderson and Pabis, Jena and Das, Lewis, Logaritmic, Midilli and Kucuk, Page, Parabolic, Wang and Singh and Weibull. The best model was selected as parabolic based on the highest coefficient of determination (R²) (0.999990 at 80°C) and the lowest χ² (0.000002 at 80°C), and the lowest root mean square error (RMSE) (0.000976 at 80°C) values are compared to other models. The effective moisture diffusivity (Deff) values were calculated using the Fick’s second law’s cylindrical coordinate approximation and are found between 6.61×10⁻⁸ and 6.66×10⁻⁷ m²/s. The activation energy (Ea) was calculated using modified form of Arrhenius equation and is found as 18.315 kW/kg.

Keywords: activation energy, drying, effective moisture diffusivity, modelling, oven, shrimp

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Authors: Amol Lanke, Hadi Hoseinie, Behzad Ghodrati

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OEE has been used in many industries as measure of performance. However due to limitations of original OEE, it has been modified by various researchers. OEE for mining application is special version of classic equation, carries these limitation over. In this paper it has been aimed to modify the OEE for mining application by introducing the weights to the elements of it and termed as Mine Production index (MPi). As a special application of new index MPi shovel has been developed by team of experts and researchers for evaluating the shovel effectiveness. Based on analysis, utilization followed by performance and availability were ranked in this order. To check the applicability of this index, a case study was done on four electrical and one hydraulic shovel in a Swedish mine. The results shows that MPishovelcan properly evaluate production effectiveness of shovels and determine effectiveness values in optimistic view compared to OEE. MPi with calculation not only give the effectiveness but also can predict which elements should be focused for improving the productivity.

Keywords: mining, overall equipment efficiency (OEE), mine production index, shovels

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Authors: Sphiwe Simelane, Daniel Madyira

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The use of natural fibers requires that they should be treated in preparation for their use in Natural Fiber-reinforced polymer composites. This paper reports on the effects of sodium hydroxide (NaOH) treatment on the surface of coconut fibers. The fibers were subjected to 5%, 10%, 15% and 20% NaOH concentrations and soaked for 4 hours and thoroughly rinsed and allowed to dry in the open air for seven days, after which time they were dried in an oven for 30 minutes. Untreated and treated coconut fibers were observed under the Scanning Electron Microscope and it was noted that the surface structure of the fibers was modified differently by the different NaOH concentrations, and the resultant colour of the treated fibers got darker as the solution concentration increased, and the texture felt rougher to the touch as a result of the erosion of the fiber surface. Further, the increase in alkali concentration striped the surface of more constituents, thus exposing “pits” and other surface components rendering the surface rough.

Keywords: coconut fiber, scanning electron microscope, sodium hydroxide, surface treatment

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Authors: Mohammad Mahdi Doustdar, Mohammad Mojtahedpoor

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The effects of flame-holder position, the ratio of flame holder diameter to combustion chamber diameter and injection angle on fuel propulsive droplets sizing and effective mass fraction have been studied by a cold flow. We named the mass of fuel vapor inside the flammability limit as the effective mass fraction. An empty cylinder as well as a flame-holder which are as a simulator for duct combustion has been considered. The airflow comes into the cylinder from one side and injection operation will be done by four nozzles which are located on the entrance of cylinder. To fulfill the calculations a modified version of KIVA-3V code which is a transient, three-dimensional, multi phase, multi component code for the analysis of chemically reacting flows with sprays, is used.

Keywords: KIVA-3V, flame-holder, duct combustion, effective mass fraction, mean diameter of droplets

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Authors: Tetsiki Taniguchi, Yoshio Karasawa

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This paper describes a subarray based low computational design method of multiuser massive multiple input multiple output (MIMO) system. In our previous works, use of large array is assumed only in transmitter, but this study considers the case both of transmitter and receiver sides are equipped with large array antennas. For this aim, receive arrays are also divided into several subarrays, and the former proposed method is modified for the synthesis of a large array from subarrays in both ends. Through computer simulations, it is verified that the performance of the proposed method is degraded compared with the original approach, but it can achieve the improvement in the aspect of complexity, namely, significant reduction of the computational load to the practical level.

Keywords: large array, massive multiple input multiple output (MIMO), multiuser, singular value decomposition, subarray, zero forcing

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Authors: Mohammadhosein Hasanbeig, Lacra Pavel

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In this paper, we study a distributed control algorithm for the problem of unknown area coverage by a network of robots. The coverage objective is to locate a set of targets in the area and to minimize the robots’ energy consumption. The robots have no prior knowledge about the location and also about the number of the targets in the area. One efficient approach that can be used to relax the robots’ lack of knowledge is to incorporate an auxiliary learning algorithm into the control scheme. A learning algorithm actually allows the robots to explore and study the unknown environment and to eventually overcome their lack of knowledge. The control algorithm itself is modeled based on game theory where the network of the robots use their collective information to play a non-cooperative potential game. The algorithm is tested via simulations to verify its performance and adaptability.

Keywords: distributed control, game theory, multi-agent learning, reinforcement learning

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Authors: Athmane Bakhta, Sebastien Leclaire, David Vidal, Francois Bertrand, Mohamed Cheriet

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This work presents a new three-dimensional variational model proposed for the simulation of ink seepage into paper sheets at the fiber level. The model, inspired by the Hising model, takes into account a finite volume of ink and describes the system state through gravity, cohesion, and adhesion force interactions. At the mesoscopic scale, the paper substrate is modeled using a discretized fiber structure generated using a numerical deposition procedure. A modified Monte Carlo method is introduced for the simulation of the ink dynamics. Besides, a multiphase lattice Boltzmann method is suggested to fine-tune the mesoscopic variational model parameters, and it is shown that the ink seepage behaviors predicted by the proposed model can resemble those predicted by a method relying on first principles.

Keywords: fibrous media, lattice Boltzmann, modelling and simulation, Monte Carlo, variational model

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Authors: Rida B. Arieby, Hameed N. Hameed

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In this work, tensile tests on high density polyethylene have been carried out under various constant strain rate and strain rate jump tests. The dependency of the true stress and specially the variation of volume strain have been investigated, the volume strain due to the phenomena of damage was determined in real time during the tests by an optical extensometer called Videotraction. A modified constitutive equations, including strain rate and damage effects, are proposed, such a model is based on a non-equilibrium thermodynamic approach called (DNLR). The ability of the model to predict the complex nonlinear response of this polymer is examined by comparing the model simulation with the available experimental data, which demonstrate that this model can represent the deformation behavior of the polymer reasonably well.

Keywords: strain rate jump tests, volume strain, high density polyethylene, large strain, thermodynamics approach

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Authors: Nam Don Kim, Jungho Moon, Tae Yun Chung

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This paper proposes an Internet of Things (IoT) based virtualization platform for providing smart tourism services. The virtualization platform provides a consistent access interface to various types of data by naming IoT devices and legacy information systems as pathnames in a virtual file system. In the other words, the IoT virtualization platform functions as a middleware which uses the metadata for underlying collected data. The proposed platform makes it easy to provide customized tourism information by using tourist locations collected by IoT devices and additionally enables to create new interactive smart tourism services focused on the tourist locations. The proposed platform is very efficient so that the provided tourism services are isolated from changes in raw data and the services can be modified or expanded without changing the underlying data structure.

Keywords: internet of things (IoT), IoT platform, serviceplatform, virtual file system (VSF)

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Authors: Wei Jin

Abstract:

Efficient and selective metal recovery from emerging solid waste, such as spent lithium batteries, electronic waste and SCR catalysts, is of great importance from both environmental and resource considerations. In order to overcome the bottlenecks of long flow-sheet and severe secondary pollution in conventional processes, the rational design of 2-electron oxygen reduction reaction (ORR) and capacitive deionization (CDI) nanomaterials were developed for the precise electrochemical metal recovery. It has been demonstrated that the modified carbon nanomaterials can be employed as 2e ORR to produce H2O2 in aqueous solution, in which the metal can be leached out from the solid waste as ions. Moreover, the multi-component metallic solution can be electrochemically extracted with good efficiency and selectivity with the nanoporous aerogel. Each system presents stable performance for long-term operation and can be used in industrial solid waste treatment. This study provides a materials-oriented, cleaner metal recovery approach for strategic metal resources sustainability.

Keywords: electrochemistry, metal recovery, waste steams, nanomaterials

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Authors: Paresh M. Patel, Amit A. Patel, R. H. Parikh

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The present investigation was undertaken to fabricate modified transport fluconazole that belongs to BCS class II and have a poor applicability on topical infection. So to improve topical application, transdermal spray could play a vital role by using ethyl cellulose and Eudragit® S100 as film-forming polymers. Concentration of Eudragit® S100, ethyl cellulose and permeation enhancer (camphor and menthol) were selected as independent variables, whereas drying time, viscosity and in-vitro drug release were selected as dependent variables in factorial design. The viscosity, drying time and in-vitro drug release of the optimize batch B15 was 40.1 cps, 47 sec. and 90.79% respectively. The film of optimized batch was flexible and dermal-adhesive.

Keywords: Eudragit, ethyl cellulose, fluconazole, transdermal spray

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Authors: Agata Chelminska, Joanna Goscianska

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The rapid growth of the world’s population and the resulting economic development have had an enormous influence on the environment. Multiple industrial processes generate huge amounts of wastewater containing dangerous substances, most of which are discharged into water bodies. These contaminants include pharmaceuticals and synthetic dyes. Regardless of the presence of wastewater treatment plants, a lot of pollutants cannot be easily eliminated by well-known technologies. Hence, more effective methods of removing resistant chemicals are being developed. Due to cost-effectiveness as well as the availability of a wide range of adsorbents, a large interest in the adsorption process as an alternative way of water purification has been observed. Clay minerals, e.g., halloysite, are one of the most researched natural adsorbents because of their availability, non-toxicity, high specific surface area, porosity, layered structure, and low cost. The negatively charged surface makes them ideal for binding cations and organic compounds. Halloysite can be subjected to modifications which enhance its adsorptive properties. The aim of the presented research was to apply pure and modified halloysite in removing particular pollutants (tetracycline, tartrazine, and phosphates) from aqueous solutions. Halloysite was modified with alcoholic and aqueous solutions of hexadecyltrimethylammonium bromide (CTAB) and urea in different concentrations and subsequently impregnated with lanthanum(III) chloride. Acidic and basic oxygen groups located on the surface of all materials were determined. Moreover, the adsorbents obtained were characterized by X-ray diffraction, low-temperature nitrogen adsorption, scanning, and transmission electron microscopy. The effectiveness of samples in tetracycline, tartrazine, and phosphates adsorption from the liquid phase was then studied in order to determine their potential application in eliminating contaminants from water reservoirs. Modifiers’ employment enabled obtaining materials that possess better adsorption properties, which makes them useful for removing various pollutants from water. Modifying the pure halloysite with CTAB and urea solutions and impregnating LaCl₃ led to the formation of acidic and basic oxygen functional groups on the surface. Their amount increases with an increasing percentage of lanthanum content. The acid-base properties of materials, as well as the type of functional groups that appear on their surface, have a significant influence on their sorption capacities towards antibiotics, dyes, and phosphate(V) anions. The selected contaminants adsorb onto the halloysite studied following the Langmuir type isotherm. The thermodynamic study indicated that the adsorption was a spontaneous and exothermic process. The adsorption equilibrium was rapidly attained after 120 min of contact time. Research showed that synthesized materials based on halloysite may be applied as adsorbents for antibiotics, organic dyes, and PO₄³- ions which are difficult to eliminate.

Keywords: adsorption processes, halloysite, minerals, water reservoirs pollutants

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