Search results for: free surface

Authors: Umesh Kumar, Arun Kumar Shukla, B. V. V. Ravindra Babu

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The paper presents a compact tri band Curved U-Slot patch antenna with improved bandwidth and isolation characteristics. The proposed antenna excited by coaxial feed resonates at tri band of 2.8 GHz, 4.1 GHz and 5.7 GHz for VSWR ≤ 1.5 with an improved bandwidth of 99.7% and also for getting high gain antenna of 11.31 dB. A 2×2 MIMO is developed using the proposed antenna giving an excellent isolation of 28 dB between the two antennas. The simulation results of return loss, Mutual Coupling, Gain, VSWR, Surface Current Distribution and Electrical Distribution are presented. By keeping the substrate thickness constant over various dielectric constants, simulations were carried out using MATLAB® and HFSS (High Frequency Structure Simulator) software.

Keywords: performance analysis, curved U-slot patch, antenna with enhanced bandwidth, isolation for mimo systems

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Authors: Henrique C. C. Andrade, Ana Beatriz C. G. Silva, Fernando Luiz B. Ribeiro, Samir Maghous, Jose Claudio F. Telles, Eduardo M. R. Fairbairn

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The present paper aims at developing a parallel computational model for numerical simulation of poromechanics analyses of heterogeneous reservoirs. In the context of macroscopic poroelastoplasticity, the hydromechanical coupling between the skeleton deformation and the fluid pressure is addressed by means of two constitutive equations. The first state equation relates the stress to skeleton strain and pore pressure, while the second state equation relates the Lagrangian porosity change to skeleton volume strain and pore pressure. A specific algorithm for local plastic integration using a tangent operator is devised. A modified Cam-clay type yield surface with associated plastic flow rule is adopted to account for both contractive and dilative behavior.

Keywords: finite element method, poromechanics, poroplasticity, reservoir analysis

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Authors: Daniella R. Mulinari, Araujo J. F. Marina, Gabriella S. Lopes

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Natural fibers are used in polymer composites to improve mechanical properties, substituting inorganic reinforcing agents produced by non-renewable resources. The present study investigates the tensile, flexural and impact behaviors of palm fibers-high density polyethylene (HDPE) composite as a function of volume fraction. The surface of the fibers was modified by mercerization treatments to improve the wetting behavior of the apolar HDPE. The treatment characterization was obtained by scanning electron microscopy, X-Ray diffraction and infrared spectroscopy. Results evidence that a good adhesion interfacial between fibers-matrix causing an increase strength and modulus flexural as well as impact strength in the modified fibers/HDPE composites when compared to the pure HDPE and unmodified fibers reinforced composites.

Keywords: palm fibers, polymer composites, mechanical properties, high density polyethylene (HDPE)

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Authors: Shalini Attri

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Silence has been 'scriptured' in women within dominating social structures, as the modes of speaking and behaving which deny women free investiture to language. A woman becomes the product of ideological constructions as language substantiates andro-centric bias. Constrained from writing/speaking in the public sphere, women have traditionally been confined to expressing themselves in writing private poetry, letters or diaries. The helplessness of a woman is revealed in the ways in which she is expected to speak a language, which, in fact, is man-made. There are visible binaries of coloniser- colonised; Western-Eastern; White-Black, Nature-Culture, even Male-Female that contribute significantly to our understanding of the concept of representation and its resultant politics. Normally, an author is labeled as feminist, humanist, or propagandist and this process of labeling correspond to a sense of politics besides his inclination to a particular field. One cannot even think of contemporary literature without this representational politics. Thus, each and every bit of analysis of a work of literature demands a political angle to be dealt with. Besides literature, the historical facts and manuscripts are also subject to this politics. The image of woman as someone either dependent on man or is exploited by him only provides half the picture of this representational politics. The present paper is an attempt to study Panchali’s (Draupadi of Mahabharata) voiceless articulation and her representation as a strong woman in Chitra Divakurani’s The Palace of Illusions.

Keywords: politics, representation, silence, social structures

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Authors: Sakapas Saengchai, Vilasinee Jintalikhitdee, Mathinee Khongsatid, Nattapol Pourprasert

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This paper studied the preparing education enter the ASEAN Community by the year 2015 the Ministry of Education has policy on ASEAN Charter, including the dissemination of information to create a good attitude about ASEAN, development of students' skills appropriately, development of educational standards to prepare for the liberalization of education in the region and Youth Development as a vital resource in advancing the ASEAN community. Preparing for the liberalization of education Commission on Higher Education (CHE) has prepared Thailand strategic to become ASEAN and support the free trade in higher education service; increasing graduate capability to reach international standards; strengthening higher educational institutions; and enhancing roles of educational institutions in the ASEAN community is main factor in set up long-term education frame 15 years, volume no. 2. As well as promoting Thailand as a center for education in the neighbor countries. As well as development data centers of higher education institutions in the region make the most of the short term plan is to supplement the curriculum in the ASEAN community. Moreover, provides a teaching of English and other languages used in the region, creating partnerships with the ASEAN countries to exchange academics staff and students, research, training, development of joint programs, and system tools in higher education.

Keywords: ASEAN community, education, institution, dissemination of information

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Authors: Ana Corberan-Vallet, Karen C. Florez, Ingrid C. Marino, Jose D. Bermudez

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In 2016, the Region of the Americas was declared free of measles, a viral disease that can cause severe health problems. However, since 2017, measles has reemerged in Venezuela and has subsequently reached neighboring countries. In 2018, twelve American countries reported confirmed cases of measles. Governmental and health authorities in Colombia, a country that shares the longest land boundary with Venezuela, are aware of the need for a strong response to restrict the expanse of the epidemic. In this work, we apply a Bayesian hierarchical Poisson model with an underlying cluster structure to describe disease incidence in Colombia. Concretely, the proposed methodology provides relative risk estimates at the department level and identifies clusters of disease, which facilitates the implementation of targeted public health interventions. Socio-demographic factors, such as the percentage of migrants, gross domestic product, and entry routes, are included in the model to better describe the incidence of disease. Since the model does not impose any spatial correlation at any level of the model hierarchy, it avoids the spatial confounding problem and provides a suitable framework to estimate the fixed-effect coefficients associated with spatially-structured covariates.

Keywords: Bayesian analysis, cluster identification, disease mapping, risk estimation

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Authors: Naveed Ejaz, Liaqat Ali, Amer Nusair

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Thermal barrier coatings (TBCs) serve as thermal barriers against the high temperature of the hot regions of the aircraft turbine engines keeping the surface of the turbine blades, vanes and combustion chamber at comparatively lower temperature. The life of these coatings depends on many in-service environmental factors. Among these factors, the behavior of the bond coat as well as the top coat at high temperature aggravated by the corrosive environments having S, V, Na and Cl plays a key role. The incorporation of the 5-15% CaZrO3 in YSZ coatings was studied after hot corrosion in vanadium oxide environment. It was observed that the reactivity of the V gradually switched from Y to Ca making CaV2O4 instead of YVO4; the percentage of CaV2O4 increased with the increase of CaZrO3 in YSZ. It eventually prevented leaching out of the Y from YSZ leaving the YSZ without any harmful phase change. The thermal insulation was found to be improved in case of CaZrO3 incorporated YSZ coatings as compared to only YSZ coating.

Keywords: hot corrosion, thermal barrier coatings, yttria stabilized zirconia, calcium zirconate

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Authors: Martin A. Curry

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Madeline Island is a small island community in Wisconsin, USA. Located in Lake Superior, it has been home to the Anishinaabe/Ojibway people for 1000s of years and is known as Moningwankuaning Minis-"The Island of the Golden Breasted Woodpecker". The community relies on summer tourism as its source of income, with a small population of 400 year-round residents. Supervisor Martin A. Curry (Ojibway/German descent) has been working on a fiscally responsible, environmentally principled and culturally centered approach to waste diversion and recycling. The tenets of this program encompass plastics, paper, food waste, local farming, energy production and art education. Through creative writing for the local newspaper and creative interactions, Martin has worked to engage the community in a more robust interest in waste diversion, including setting up a free-will donation store that incorporates elder volunteering opportunities, a compost program that works with the local community garden, biodiesel production and an art program that works with children from the local island school to make paper, grow local food and paint murals. The entirety of this program is based on the Ojibway concept of Mino-Bimadiiziwiin- "The Good Life" and benefits the community and its guests and represents a microcosm of the global dilemmas of waste and recycling.

Keywords: recycling, waste diversion, island, Native American, art

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Authors: Onkar Nath Verma, Nitish Kumar Singh, Raghvendra, Pravin Kumar, Prabhakar Singh

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The perovskite type electrolyte material LaAlO3 was prepared by solution based auto-combustion method using Al (NO3)3.6H2O, La2O3 with dilute nitrate acid (HNO3) as precursors and citric acid (C6H8O7.H2O) as a fuel. The synthesis protocol gave an easy processing of the LaAlO3 nano-particles. The XRD measurement revealed that the material has single phase with space group R-3c (rhombohedral). Thermal behavior was measured by simultaneous differential thermal analysis and thermo gravimetric analysis (DTA-TGA). The compact pellet density was determined. Also, the surface morphology was studied using scanning electron microscopy (SEM). The conductivity of LaAlO3 was measured employing LCR meter and found to increase with increasing temperature. This increase in conductivity may be attributed to increased mobility of oxide ion.

Keywords: perovskite, LaAlO3, XRD, SEM, DTA-TGA, SOFC

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Authors: Talat Baran

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Palladium-catalyzed Suzuki coupling reactions are powerful ways for synthesis of biaryls compounds and so far different palladium sources as have been used in catalyst systems. However, the high cost of the ligands using as support materials for palladium ion and so researchers have explored alternative low-cost support materials such as silica, cellule and zeolite. A natural polymer chitosan is suitable for support material because of it unique properties such as eco-friendly, renewable, abundant, low cost, biodegradable and it has free reactive -NH2 and –OH groups. Especially, pendant amino groups of chitosan can easily react with carbonyl groups of aldehyde or ketone by Schiff base formation and thus palladium ions can coordinate with imine groups of Schiff base. This purpose, in this study, firstly a new chitosan Schiff base supported palladium (II) catalyst was synthesized and its chemical structure was characterized with FT-IR, SEM/EDAX, XRD, TG-DTG, ICP-OES and magnetic moment techniques. Then catalytic performance of the catalyst was investigated in Suzuki cross coupling reactions under simple and fast microwave heating methods. Also, recycle activity of palladium catalyst was tested under optimum condition and the catalyst showed long life time. At the end of catalytic performance tests of chitosan supported palladium (II) catalysts indicated high turnover numbers, turnover frequency and selectivity with very small loading catalyst

Keywords: catalyst, chitosan, Schiff base, Suzuki coupling

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Authors: R. F. Louh, Cathy Chou, Victor Wang, Howard Yan

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The aim of this study is to manufacture titania and reduced graphene oxide (TiO2/rGO) composite nanofibers via electrospinning (ESP) of precursor fluid consisted of titania sol containing polyvinylpyrrolidone (PVP) and titanium isopropoxide (TTIP) and GO solution. The GO nanoparticles were derived from Hummers’ method. A metal grid ring was used to provide the bias voltage to reach higher ESP yield and nonwoven fabric with dense network of TiO2/GO composite nanofibers. The ESP product was heat treated at 500°C for 2 h in nitrogen atmosphere to acquire TiO2/rGO nanofibers by thermal reduction of GO and phase transformation into anatase TiO2. The TiO2/rGO nanofibers made from various volume fractions of GO solution by ESP were analyzed by FE-SEM, TEM, XRD, EDS, BET and FTIR. Such TiO2/rGO fibers having photocatalytic property, high specific surface area and electrical conductivity can be used for photovoltaics and chemical sensing applications.

Keywords: electrospinning process, titanium oxide, thermally reduced graphene oxide, composite nanofibers

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Authors: Wahid Dianbudiyanto, Shou Heng Liu

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Capacitive deionization (CDI) is a prospective desalination technology, which can be operated at low voltage, low temperature and potentially consume low energy for brackish water desalination. To obtain the optimal electrosorption, an electrode should possess high electrical conductivity, large surface area, good wettability, highly mesoporous structure which provide efficient pathways for ion distribution. In this work, a 3D structure graphene was fabricated using hydrothermal method which is assisted with microwave treatments to form 3D rGO (3DG-Mw-Hyd). The prepared samples have excellent specific capacitance (189.2 F / g) and ultrahigh electrosorption capacity (30 mg/g) for the desalination of 500 mg / l NaCl. These results are superior to the electrode which is fabricated only using the hydrothermal method without microwave assistance (3DG-Hyd) and traditional reflux method. Physical characterizations such as SEM, TEM, and XRD have been used to study the property difference of the materials. The preliminary results show that 3DG-Mw-Hyd is one of the promising electrodes for CDI in the practical applications.

Keywords: capacitive deionization, graphene, microwave, hydrothermal, electrosorption

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Authors: Mohammad Hossein Modarressi, Mozhgan Mondeali, Khabat Barkhordari, Ali Etemadi

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The COVID-19 pandemic, caused by SARS-CoV-2, has led to significant concerns worldwide due to its catastrophic effects on public health. The SARS-CoV-2 infection is initiated with the binding of the receptor-binding domain (RBD) in its spike protein to the ACE2 receptor in the host cell membrane. Due to the error-prone entity of the viral RNA-dependent polymerase complex, the virus genome, including the coding region for the RBD, acquires new mutations, leading to the appearance of multiple variants. These variants can potentially impact transmission, virulence, antigenicity and evasive immune properties. S477N mutation located in the RBD has been observed in the SARS-CoV-2 omicron (B.1.1. 529) variant. In this study, we investigated the consequences of S477N mutation at the molecular level using computational approaches such as molecular dynamics simulation, protein-protein interaction analysis, immunoinformatics and free energy computation. We showed that displacement of Ser with Asn increases the stability of the spike protein and its affinity to ACE2 and thus increases the transmission potential of the virus. This mutation changes the folding and secondary structure of the spike protein. Also, it reduces antibody neutralization, raising concern about re-infection, vaccine breakthrough and therapeutic values.

Keywords: S477N, COVID-19, molecular dynamic, SARS-COV2 mutations

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Authors: Ofosuhene O. Apenteng, Noor Azina Ismail

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Over the last several years, concern has developed over how to minimize the spread of HIV/AIDS epidemic in many countries. AIDS epidemic has tremendously stimulated the development of mathematical models of infectious diseases. The transmission dynamics of HIV infection that eventually developed AIDS has taken a pivotal role of much on building mathematical models. From the initial HIV and AIDS models introduced in the 80s, various improvements have been taken into account as how to model HIV/AIDS frameworks. In this paper, we present the impact of migration on the spread of HIV/AIDS. Epidemic model is considered by a system of nonlinear differential equations to supplement the statistical method approach. The model is calibrated using HIV incidence data from Malaysia between 1986 and 2011. Bayesian inference based on Markov Chain Monte Carlo is used to validate the model by fitting it to the data and to estimate the unknown parameters for the model. The results suggest that the migrants stay for a long time contributes to the spread of HIV. The model also indicates that susceptible individual becomes infected and moved to HIV compartment at a rate that is more significant than the removal rate from HIV compartment to AIDS compartment. The disease-free steady state is unstable since the basic reproduction number is 1.627309. This is a big concern and not a good indicator from the public heath point of view since the aim is to stabilize the epidemic at the disease equilibrium.

Keywords: epidemic model, HIV, MCMC, parameter estimation

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Authors: Pinar Erturk, Sevde Altuntas, Fatih Buyukserin

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In order to obtain an effective integration between an implant and a bone, implant surfaces should have similar properties to bone tissue surfaces. Especially mimicry of the chemical, mechanical and topographic properties of the implant to the bone is crucial for fast and effective osseointegration. Titanium-based biomaterials are more preferred in clinical use, and there are studies of coating these implants with oxide layers that have chemical/nanotopographic properties stimulating cell interactions for enhanced osseointegration. There are low success rates of current implantations, especially in craniofacial implant applications, which are large and vital zones, and the oxide layer coating increases bone-implant integration providing long-lasting implants without requiring revision surgery. Our aim in this study is to examine bone-cell behavior on titanium implants with an aluminum oxide layer (AAO) on effective osseointegration potential in the deformation of large zones with difficult spontaneous healing. In our study, aluminum layer coated titanium surfaces were anodized in sulfuric, phosphoric, and oxalic acid, which are the most common used AAO anodization electrolytes. After morphologic, chemical, and mechanical tests on AAO coated Ti substrates, viability, adhesion, and mineralization of adult bone cells on these substrates were analyzed. Besides with atomic layer deposition (ALD) as a sensitive and conformal technique, these surfaces were coated with pure alumina (5 nm); thus, cell studies were performed on ALD-coated nanoporous oxide layers with suppressed ionic content too. Lastly, in order to investigate the effect of the topography on the cell behavior, flat non-porous alumina layers on silicon wafers formed by ALD were compared with the porous ones. Cell viability ratio was similar between anodized surfaces, but pure alumina coated titanium and anodized surfaces showed a higher viability ratio compared to bare titanium and bare anodized ones. Alumina coated titanium surfaces, which anodized in phosphoric acid, showed significantly different mineralization ratios after 21 days over other bare titanium and titanium surfaces which anodized in other electrolytes. Bare titanium was the second surface that had the highest mineralization ratio. Otherwise, titanium, which is anodized in oxalic acid electrolyte, demonstrated the lowest mineralization. No significant difference was shown between bare titanium and anodized surfaces except AAO titanium surface anodized in phosphoric acid. Currently, osteogenic activities of these cells on the genetic level are investigated by quantitative real-time polymerase chain reaction (qRT-PCR) analysis results of RUNX-2, VEGF, OPG, and osteopontin genes. Also, as a result of the activities of the genes mentioned before, Western Blot will be used for protein detection. Acknowledgment: The project is supported by The Scientific and Technological Research Council of Turkey.

Keywords: alumina, craniofacial implant, MG-63 cell line, osseointegration, oxalic acid, phosphoric acid, sulphuric acid, titanium

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Authors: Robert Long, Hiroaki Watanabe

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This longitudinal study examines the grammatical errors of Japanese university students’ dialogues with a native speaker over an academic year. The L2 interactions of 15 Japanese speakers were taken from the JUSFC2018 corpus (April/May 2018) and the JUSFC2019 corpus (January/February). The corpora were based on a self-introduction monologue and a three-question dialogue; however, this study examines the grammatical accuracy found in the dialogues. Research questions focused on a possible significant difference in grammatical accuracy from the first interview session in 2018 and the second one the following year, specifically regarding errors in clauses per 100 words, global errors and local errors, and with specific errors related to parts of speech. The investigation also focused on which forms showed the least improvement or had worsened? Descriptive statistics showed that error-free clauses/errors per 100 words decreased slightly while clauses with errors/100 words increased by one clause. Global errors showed a significant decline, while local errors increased from 97 to 158 errors. For errors related to parts of speech, a t-test confirmed there was a significant difference between the two speech corpora with more error frequency occurring in the 2019 corpus. This data highlights the difficulty in having students self-edit themselves.

Keywords: clause analysis, global vs. local errors, grammatical accuracy, L2 output, longitudinal study

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Authors: Marisa Rio, Sharanya Bola, Richard H. W. Funk, Gerald Gerlach

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Cell migration, wound healing and regeneration are some of the physiological phenomena in which electric fields (EFs) have proven to have an important function. Physiologically, cells experience electrical signals in the form of transmembrane potentials, ion fluxes through protein channels as well as electric fields at their surface. As soon as a wound is created, the disruption of the epithelial layers generates an electric field of ca. 40-200 mV/mm, directing cell migration towards the wound site, starting the healing process. In vitro electrotaxis, experiments have shown cells respond to DC EFs polarizing and migrating towards one of the poles (cathode or anode). A standard electrotaxis experiment consists of an electrotaxis chamber where cells are cultured, a DC power source and agar salt bridges that help delaying toxic products from the electrodes to attain the cell surface. The electric field strengths used in such an experiment are uniform and homogeneous. In contrast, the endogenous electric field strength around a wound tend to be multi-field and non-homogeneous. In this study, we present a custom device that enables electrotaxis experiments in non-homogeneous DC electric fields. Its main feature involves the replacement of conventional metallic electrodes, separated from the electrotaxis channel by agarose gel bridges, through electrolyte-filled microchannels. The connection to the DC source is made by Ag/AgCl electrodes, incased in agarose gel and placed at the end of each microfluidic channel. An SU-8 membrane closes the fluidic channels and simultaneously serves as the single connection from each of them to the central electrotaxis chamber. The electric field distribution and current density were numerically simulated with the steady-state electric conduction module from ANSYS 16.0. Simulation data confirms the application of nonhomogeneous EF of physiological strength. To validate the biocompatibility of the device cellular viability of the photoreceptor-derived 661W cell line was accessed. The cells have not shown any signs of apoptosis, damage or detachment during stimulation. Furthermore, immunofluorescence staining, namely by vinculin and actin labelling, allowed the assessment of adhesion efficiency and orientation of the cytoskeleton, respectively. Cellular motility in the presence and absence of applied DC EFs was verified. The movement of individual cells was tracked for the duration of the experiments, confirming the EF-induced, cathodal-directed motility of the studied cell line. The in vitro monolayer wound assay, or “scratch assay” is a standard protocol to quantitatively access cell migration in vitro. It encompasses the growth of a confluent cell monolayer followed by the mechanic creation of a scratch, representing a wound. Hence, wound dynamics was monitored over time and compared for control and applied the electric field to quantify cellular population motility.

Keywords: DC non-homogeneous electric fields, electrotaxis, microfluidic biochip, wound healing

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Authors: Mona Mahmoud Abou Samra, Alaa Hamed Salama, Ghada Awad, Soheir Said Mansy

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Proniosomes are well documented for topical drug delivery and preferred over other vesicular systems because they are biodegradable, biocompatible, non-toxic, possess skin penetration ability and prolong the release of drugs by acting as depot in deeper layers of skin. Proniosome drug delivery was preferred due to improved stability of the system than niosomes. The present investigation aimed at formulation development and performance evaluation of proniosomal gel as a vesicular drug carrier system for antifungal drug tolnaftate. Proniosomes was developed using different nonionic surfactants such as span 60 and span 65 with cholesterol in different molar ratios by the Coacervation phase separation method in presence or absence of either lecithin or phospholipon 80 H. Proniosomal gel formulations of tolnaftate were characterized for vesicular shape & size, entrapment efficiency, rheological properties and release study. The effect of surfactants and additives on the entrapment efficiency, particle size and percent of drug released was studied. The selected proniosomal formulations for topical delivery of tolnaftate was subjected to a microbiological study in male rats infected with Trichophyton rubrum; the main cause of Tinea Pedis compared to the free drug and a market product and the results was recorded.

Keywords: fungal infection, proniosome, tolnaftate, trichophyton rubrum

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Authors: Agata Twardoch

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The processes of commodification of real estate and changes in housing markets have led to a situation where the prices of free market housing in European capitals are significantly higher than the purchasing value of average wages. This phenomenon has many negative social and spatial consequences. At the same time, the attractiveness of real estate as an asset makes these processes progress. Out of concern for sustainable social development, city authorities apply solutions to balance the burdensome effects of codification of housing. One of them is a social provision for housing investments. The article presents a comparative study of solutions applied in selected European capitals, on the example of Warsaw, Paris, London, Berlin, Copenhagen, and Vienna. The study was conducted along with works on expert report for the master plan for Warsaw. The forms of commissions applied in Local Planning Acts were compared, with particular reference to spatial solutions. The results of the analysis made it possible to determine common features of the solutions applied and to establish recommendations for further practice. Major findings of the study indicate that requirement of social provision is achievable in spatial planning documents. Study shows that application of social provision in private housing investments is a useful tool in housing policy against commodification.

Keywords: affordable housing, housing provision, spatial planning, sustainable social development

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Authors: Nguyen Van Que, Nguyen Huy The

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This paper presents combined natural and forced convection of humid air flow. The film condensation of water vapour on a cold floor was investigated using ANSYS Fluent software. User-defined Functions(UDFs) were developed and added to address the issue of film condensation at the surface of the floor. Those UDFs were validated by analytical results on a flat plate. The film condensation model based on mass transfer was used to solve phase change. On the floor, condensation rate was obtained by mass fraction change near the floor. The study investigated effects of inlet velocity, inlet relative humidity and cold floor temperature on the condensation rate. The simulations were done in both 2D and 3D models to show the difference and need for 3D modeling of condensation.

Keywords: heat and mass transfer, convection, condensation, relative humidity, user-defined functions

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Authors: Yoel Agustheo Rinding

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Globalization has made physical borders between countries become more obscure. Due to the free flow of information between countries, issue for instance, environment has become global concern. The concern has grown as the result of endless campaign made by most of the non-governmental organizations (NGOs). By means of this situation, international voluntary initiatives on environmental issues have appeared to be popular among world’s society today especially for youth. AIESEC as international non-governmental organization (INGO) through IGreen Project has initiated environmental international voluntary initiatives concerning in environmental awareness of Bandung’s citizen. Bandung itself is still struggling on solving flood as one of its major problems regardless the fact that Bandung is one of the most developed cities in Indonesia. This paper would like to discuss on how globalization affects AIESEC as an INGO in order to spread its influence and also on how it could build international voluntary initiatives networks. Afterwards, author would like to elaborate how both AIESEC and youth perceive the importance of international voluntary initiatives by using cosmopolitanism approach. In order to get a deep understanding of how this activity works, this paper also would like to explain regarding the management, expected outcomes, and the real impacts of IGreen project towards Bandung. In the end of this paper, author would like to propose solutions on how to utilize international voluntary initiatives as a solution for environmental issues nowadays.

Keywords: AIESEC, cosmopolitanism, environmental issues, globalization, IGreen project, international environmental voluntary initiatives, INGO, youth

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Authors: Behnam Shakerian, Negin Razavi

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The pathogenesis of coronary artery disease is multifactorial. The epicardial fat pad is a localized fat depot lying between the myocardium and the visceral layer of the pericardium. The mechanisms through which epicardial fat pad can cause atherosclerosis are complex. The epicardial fat pad can surround the coronary arteries and contributes to the development and progression of coronary artery disease. Methods: we selected 50 patients who underwent coronary artery angiography for the evaluation of coronary artery disease that results were positive for coronary artery disease. All patients underwent an echocardiographic examination after coronary angiography to measure epicardial fat pad thickness. The epicardial fat pad was defined as an echo-free space between the myocardium's outer wall and the pericardium's visceral layer. Results: The epicardial fat pad was measured on the right ventricle apex in 46 patients. Sixty- five percent of the studied patients were male. The most common vessel with stenosis was the left anterior descending artery. A significant correlation was observed between epicardial fat pad thickness and the severity of coronary artery disease. Discussions: The epicardial fat pad provides a horizon on the pathophysiology of cardiovascular diseases. It directly contributes to the development and progression of coronary artery disease by causing inflammation and endothelial damage. Further investigations are needed to determine whether medical treatment can reduce the mass of epicardial fat pad and can help to improve atherosclerosis. Conclusion: The epicardial fat pad measurement could be used as an indicator of coronary arteries’ atherosclerosis. Therefore, thickness measurement of the epicardial fat pad in the clinical practice could be of assistance in identifying patients at risk and if required, undergoing supplementary diagnosis with coronary angiography.

Keywords: epicardial, fat pad, coronary artery disease, echocardiography

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Authors: R. Nayak, T. Panwar, R. Padhye

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Protective textiles get soiled, stained and even worn during their use, which may not be usable after a certain period due to the loss of protective performance. They need regular cleaning and maintenance, which helps to extend the durability of the clothing, retains their useful properties and ensures that fresh clothing is ready to wear when needed. Generally, the cleaning processes used for various protective clothing include dry-cleaning (using solvents) or wet cleaning (using water). These cleaning processes can alter the fabric surface properties, dimensions, and physical, mechanical and performance properties. The technology of laundering and dry-cleaning has undergone several changes. Sustainable methods and products are available for faster, safer and improved cleaning of protective textiles. We performed a comprehensive and systematic review of green technologies and eco-friendly products for sustainable cleaning of protective textiles. Special emphasis is given on the care and maintenance procedures of protective textiles for protection from fire, bullets, chemical and other types of protective clothing.

Keywords: Sustainable cleaning, protective textiles, ecofriendly cleaning, ozone laundering, ultrasonic cleaning

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Authors: Abhinav Sirvaiya, Karan Gupta, Pankaj Garg

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The global warming due to the increased atmospheric carbon dioxide (CO2) concentration is the most prominent issue of environment that the world is facing today. To solve this problem at global level, sequestration of CO2 in deep and unmineable coal seams has come out as one of the attractive alternatives to reduce concentration in atmosphere. This sequestration technology is not only going to help in storage of CO2 beneath the sub-surface but is also playing a major role in enhancing the coal bed methane recovery (ECBM) by displacing the adsorbed methane. This paper provides the answers for the need of CO2 injection in coal seams and how recovery is enhanced. We have discussed the recent development in enhancing the coal bed methane recovery and the economic scenario of the same. The effect of injection on the coal reservoir has also been discussed. Coal is a good absorber of CO2. That is why the sequestration of CO2 is emerged out to be a great approach, not only for storage purpose but also for enhancing coal bed methane recovery.

Keywords: global warming, carbon dioxide (CO2), CO2 sequestration, enhance coal bed methane (ECBM)

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Authors: Bo-Gaun Chen, Chiung-Hui Huang, Mei-Ching Chiang, Kuo-Hsing Lee, Chia-Chen Ho, Chin-Ping Huang, Chin-Heng Tien

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It is known that the natural dyeing of cloth results moderate color, but with poor color fastness. This study points out the correlation between the macroscopic color fastness of natural dye to the cotton fiber and the microscopic binding energy of dye molecule to the cellulose. With the additive metallic mordant, the new-formed coordination bond bridges the dye to the fiber surface and thus affects the color fastness as well as the color appearance. The density functional theory (DFT) calculation is therefore used to explore the most possible mechanism during the dyeing process. Finally, the experimental results reflect the strong effect of three different metal ions on the natural dyeing clothes.

Keywords: binding energy, color fastness, density functional theory (DFT), natural dyeing, metallic mordant

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Authors: Abdallah Mohamed Kamel Mohamed Ali, Samah Saad Zahran, Mohamed Hamed Rashad

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Background: Flexible flatfoot (FFF) has been considered as a risk factor for several lower limb injuries and mechanical low back pain. This was attributed to the dysfunction of the lumbopelvic-hip complex musculature. Objective: To investigate the influence of FFF on electromyographic activities of erector spinae and multifidus. Methods: A cross-section study was held between an FFF group (20 subjects) and a normal foot group (20 subjects). A surface electromyography was used to assess the electromyographic activity of erector spinae and multifidus. Group differences were assessed by the T-test. Results: There was a significant increase in EMG activities of erector spinae and multifidus in the FFF group compared with the normal group. Conclusion: There is an increase in EMG activities in erector spinae and multifidus in FFF subjects compared with normal subjects.

Keywords: electromyography, flatfoot, low back pain, paraspinal muscles

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Authors: Abigail Parra Parra, Jorge L. Morelos Hernandez, Pedro A. Marquez Agilar, Marina Vlasova, Jesus Colin De La Cruz

Abstract:

Carbothermal reduction of metal oxides is widely used both in metallurgical processes and in the production of oxygen-free refractory ceramics. As a rule, crushed coke and graphite are used as a reducing agent. The products of carbonization of organic compounds are among the innovative reducing agents. The aim of this work was to study the process of reduction of iron oxide (hematite) down to iron by waste active sludge (WAS) carbonization products. WAS was chosen due to the accumulation of a large amount of this type of waste, soil pollution, and the relevance of the development of technologies for its disposal. The studies have shown that the temperature treatment of mixtures WAS-Fe₂O₃ in the temperature range 900-1000 ºC for 1-5 hours under oxygen deficiency is described by the following scheme: WAS + Fe₂O₃→ C,CO + Fe₂O₃→ C + FexO → Fe (amorphous and crystalline). During the heat treatment of the mixtures, strong samples are formed. The study of the electrical conductive properties of such samples showed that, depending on the ratio of the components in the initial mixtures, it is possible to change the values of electrical resistivity from 5.6 Ω‧m to 151.6 Ω‧m When a current is passed through the samples, they are heated from 240 to 378ºC. Thus, based on WAS-Fe₂O₃ mixtures, heating elements can be created that can be used to heat ceramics and concrete.

Keywords: Fe₂O₃, reduction, waste activate sludge, electroconductivity

Procedia PDF Downloads 119

Authors: Z. Mmango, U. Nwodo, L. V. Mabinya, A. I. Okoh

Abstract:

Cellulose and hemicellulose account for a large portion of the world‘s plant biomass. In nature, these polysaccharides are intertwined forming complex materials that requires multiple and expensive treatment processes to free up the raw materials trapped in the matrix. Enzymatic degradation remains as the preferred technique as it is inexpensive and eco-friendly. However, the insufficiencies of enzyme battery systems in the degradation of lignocellulosic complex motivate the search for effective degrading enzymes from bacterial isolates from uncommon environment. The study aimed at the evaluation of actinomycetes isolated from saw dust samples collected from wood factory under bed. Cellulase and xylanase production was screened through organism culture on carboxyl methyl cellulose agar and Birchwood xylan. Halo zone indicating lignocellose utilization was shown by an isolate identified through 16S rRNA gene as Micrococcus luteus. The optimum condition for the production of cellulase and xylanase were incubation temperature of 25 °C, fermentation medium pH 5 and 10, agitation speed of 50 and 200 (rpm) and fermentation incubation time of 96 and 84 (h) respectively. The high cellulose and xylanase activity obtained from this isolate portends industrial relevance.

Keywords: carboxyl methyl cellulose, birchwood xylan, optimization, cellulase, xylanase, micrococcus, DNS method

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Authors: C. C. Igwe

Abstract:

Several parts of Neem tree (Azadirachta indica) are used in traditional medicine in many West African countries for the treatment of various human diseases. The leaf, stem - bark and seed were air dried for 8, 5 and 7 days, respectively. The shells were carfully separated from the seeds, each powdered sample obtained with mechanical miller and 250 mm sieve. The neem samples were individually subjected to extraction with acetone, n-hexane for 48hr and 72 hr, respectively. Physico-chemical and antibacterial evaluation were carried out using standard methods. Results of physico - chemical analyses of the extracted oil from the seed shows that it has a brownish colour, with a smell similar to garlic while the moisture content, refractive index are 0.76% and 1.47 respectively. Other vital chemical results obtained from the neem oil such as saponification value (234.62), acid value (10.84 %), free fatty acid (5.84 %) and peroxide value (10.52%) indicated the oil extracted satisfied standard oils parameters for quality soap and cosmetics production. The antibacterial screening by disc diffusion revealed the oil demonstrated high activity against Staphylococcus aureus. Both the physio-chemical and antibacterial of samples have been certified by National Agency for Food and Drugs Administration and Control. The preliminary results of this study may validate the medicinal value of the plant. Further studies are in progress to clarify the in vivo potentials of neem extracts in the management of human communicable diseases and this is a subject of investigation in our group.

Keywords: anti-bacterial, neem extract, physico-chemical analyses, staphylococcus aureus

Procedia PDF Downloads 53

Authors: Parvin Farzanegi

Abstract:

Background: Diabetes is a metabolic disorder associated with increased free radicals and oxidative stress. The evidence indicates that physical inactivity is a modifiable behavioral risk factor for a wide range of chronic disorders such as diabetes mellitus. We investigated the effects of eight-week aerobic exercise on some antioxidant enzyme activities in postmenopausal women with type 2 diabetes mellitus (T2DM). Methods: sixteen sedentary postmenopausal women with T2DM were randomly assigned to the control (n=8; CG) and exercise group (n=8; EG). The exercise consisted of progressive aerobic training at a moderate intensity (50-70% of the maximum heart rate), for 25-60 min/day, and 3 days/week for 8 weeks. Age, sex, and body mass index were similar in the two groups. Antioxidant status was evaluated by measuring the superoxide dismutase (SOD) and catalase (CAT) activity. Also levels of malondialdehyde (MDA) as an index of lipid peroxidation and glucose in the plasma were measured before and after the intervention. Results: Following the 8 weeks of exercise training, the plasma MDA and glucose levels were significantly reduced in EG compared to CG (P=0.001 and P=0.011 respectively). However, SOD (P=0.017) and CAT (P=0.011) activities were increased in EG compared to CG. Conclusion: The present study suggests regular aerobic exercise appears can exert protective effects against oxidative stress due to its ability to increase antioxidant defense and glucose control in postmenopausal women with T2DM.

Keywords: aerobic exercise, antioxidant, diabetes mellitus, type 2

Procedia PDF Downloads 155