Search results for: structural composites
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 5121

Search results for: structural composites

4041 Thiourea Modified Cadmium Sulfide Film for Solar Cell Application

Authors: Rupali Mane

Abstract:

Cadmium sulfide (Cds) thin films were chemically deposited at room temperature, from aqueous ammonia solution using CdCl₂ (Cadmium chloride) as a Cd²⁺ and CS(NH₂)₂ (Thiourea) as S² ion sources. ‘as-deposited’ films were uniform, well adherent to the glass substrate, secularly reflective and yellowish in color. The ‘as-deposited ’Cds layers grew with nano-crystalline in nature and exhibit cubic structure, with blue-shift in optical band gap. The films were annealed in air atmosphere for two hours at different temperatures and further characterized for compositional, structural, morphological and optical properties. The XRD and SEM studies clearly revealed the systematic changes in morphological and structural form of Cds films with an improvement in the crystal quality. The annealed films showed ‘red-shift’ in the optical spectra after thermal treatment. The Thiourea modified CdS film could be good to provide solar cell application.

Keywords: cadmium sulfide, thin films, nano-crystalline, XRD

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4040 Properties of Hot-Pressed Alumina-Graphene Composites

Authors: P. Rutkowski, G. Górny, L. Stobierski, D. Zientara, W. Piekarczyk, K. Tran

Abstract:

The polycrystalline dense alumina shows thermal conductivity about 30 W/mK and very high electrical resistivity. These last two properties can be modified by introducing commercial relatively cheap graphene nanoparticles which, as two-dimensional flakes show very high thermal and electrical properties. The aim of this work is to show that it is possible to manufacture the anisotropic alumina-graphene material with directed multilayer graphene particles. Such materials can show the anisotropic properties mentioned before.

Keywords: alumina, composite, hot-pressed, graphene, properties

Procedia PDF Downloads 273
4039 Localization of Frontal and Temporal Speech Areas in Brain Tumor Patients by Their Structural Connections with Probabilistic Tractography

Authors: B.Shukir, H.Woo, P.Barzo, D.Kis

Abstract:

Preoperative brain mapping in tumors involving the speech areas has an important role to reduce surgical risks. Functional magnetic resonance imaging (fMRI) is the gold standard method to localize cortical speech areas preoperatively, but its availability in clinical routine is difficult. Diffusion MRI based probabilistic tractography is available in head MRI. It’s used to segment cortical subregions by their structural connectivity. In our study, we used probabilistic tractography to localize the frontal and temporal cortical speech areas. 15 patients with left frontal tumor were enrolled to our study. Speech fMRI and diffusion MRI acquired preoperatively. The standard automated anatomical labelling atlas 3 (AAL3) cortical atlas used to define 76 left frontal and 118 left temporal potential speech areas. 4 types of tractography were run according to the structural connection of these regions to the left arcuate fascicle (FA) to localize those cortical areas which have speech functions: 1, frontal through FA; 2, frontal with FA; 3, temporal to FA; 4, temporal with FA connections were determined. Thresholds of 1%, 5%, 10% and 15% applied. At each level, the number of affected frontal and temporal regions by fMRI and tractography were defined, the sensitivity and specificity were calculated. At the level of 1% threshold showed the best results. Sensitivity was 61,631,4% and 67,1523,12%, specificity was 87,210,4% and 75,611,37% for frontal and temporal regions, respectively. From our study, we conclude that probabilistic tractography is a reliable preoperative technique to localize cortical speech areas. However, its results are not feasible that the neurosurgeon rely on during the operation.

Keywords: brain mapping, brain tumor, fMRI, probabilistic tractography

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4038 An Enzyme Technology - Metnin™ - Enables the Full Replacement of Fossil-Based Polymers by Lignin in Polymeric Composites

Authors: Joana Antunes, Thomas Levée, Barbara Radovani, Anu Suonpää, Paulina Saloranta, Liji Sobhana, Petri Ihalainen

Abstract:

Lignin is an important component in the exploitation of lignocellulosic biomass. It has been shown that within the next years, the yield of added-value lignin-based chemicals and materials will generate renewable alternatives to oil-based products (e.g. polymeric composites, resins and adhesives) and enhance the economic feasibility of biorefineries. In this paper, a novel technology for lignin valorisation (METNIN™) is presented. METNIN™ is based on the oxidative action of an alkaliphilic enzyme in aqueous alkaline conditions (pH 10-11) at mild temperature (40-50 °C) combined with a cascading membrane operation, yielding a collection of lignin fractions (from oligomeric down to mixture of tri-, di- and monomeric units) with distinct molecular weight distribution, low polydispersity and favourable physicochemical properties. The alkaline process conditions ensure the high processibility of crude lignin in an aqueous environment and the efficiency of the enzyme, yielding better compatibility of lignin towards targeted applications. The application of a selected lignin fraction produced by METNIN™ as a suitable lignopolyol to completely replace a commercial polyol in polyurethane rigid foam formulations is presented as a prototype. Liquid lignopolyols with a high lignin content were prepared by oxypropylation and their full utilization in the polyurethane rigid foam formulation was successfully demonstrated. Moreover, selected technical specifications of different foam demonstrators were determined, including closed cell count, water uptake and compression characteristics. These specifications are within industrial standards for rigid foam applications. The lignin loading in the lignopolyol was a major factor determining the properties of the foam. In addition to polyurethane foam demonstrators, other examples of lignin-based products related to resins and sizing applications will be presented.

Keywords: enzyme, lignin valorisation, polyol, polyurethane foam

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4037 Monitoring a Membrane Structure Using Non-Destructive Testing

Authors: Gokhan Kilic, Pelin Celik

Abstract:

Structural health monitoring (SHM) is widely used in evaluating the state and health of membrane structures. In the past, in order to collect data and send it to a data collection unit on membrane structures, wire sensors had to be put as part of the SHM process. However, this study recommends using wireless sensors instead of traditional wire ones to construct an economical, useful, and easy-to-install membrane structure health monitoring system. Every wireless sensor uses a software translation program that is connected to the monitoring server. Operational neural networks (ONNs) have recently been developed to solve the shortcomings of convolutional neural networks (CNNs), such as the network's resemblance to the linear neuron model. The results of using ONNs for monitoring to evaluate the structural health of a membrane are presented in this work.

Keywords: wireless sensor network, non-destructive testing, operational neural networks, membrane structures, dynamic monitoring

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4036 Full-Potential Investigation of the Electronic and Magnetic Properties of CdCoTe and CdMnTe Diluted Magnetic Semiconductors

Authors: A.Zitouni, S.Bentata, B.Bouadjemi, T.Lantri, W. Benstaali, Z.Aziz, S.Cherid

Abstract:

We investigate the structural, electronic and magnetic properties of the diluted magnetic semiconductors (DMSs) CdCoTe and CdMnTe in the zinc blende phase with 25% of Co and Mn. The calculations are performed by the recent ab initio full potential augmented plane waves (FP_L/APW) method within the spin polarized density-functional theory (DFT) and the generalized gradient approximation GGA. Structural properties are determined from the total energy calculations and we found that these compounds are stable in the ferromagnetic phase. We discuss the electronic structures, total and partial densities of states and total magnetic moments. The calculated densities of states presented in this study identify the half-metallic of CdCoTe and CdMnTe.

Keywords: electronic structure, half-metallic, magnetic moment, total and partial densities of states

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4035 Hope as a Predictor for Complicated Grief and Anxiety: A Bayesian Structural Equational Modeling Study

Authors: Bo Yan, Amy Y. M. Chow

Abstract:

Bereavement is recognized as a universal challenging experience. It is important to gather research evidence on protective factors in bereavement. Hope is considered as one of the protective factors in previous coping studies. The present study aims to add knowledge by investigating hope at the first month after death to predict psychological symptoms altogether including complicated grief (CG), anxiety, and depressive symptoms at the seventh month. The data were collected via one-on-one interview survey in a longitudinal project with Hong Kong hospice users (sample size 105). Most participants were at their middle age (49-year-old on average), female (72%), with no religious affiliation (58%). Bayesian Structural Equation Modeling (BSEM) analysis was conducted on the longitudinal dataset. The BSEM findings show that hope at the first month of bereavement negatively predicts both CG and anxiety symptoms at the seventh month but not for depressive symptoms. Age and gender are controlled in the model. The overall model fit is good. The current study findings suggest assessing hope at the first month of bereavement. Hope at the first month after the loss is identified as an excellent predictor for complicated grief and anxiety symptoms at the seventh month. The result from this sample is clear, so it encourages cross-cultural research on replicated modeling and development of further clinical application. Particularly, practical consideration for early intervention to increase the level of hope has the potential to reduce the psychological symptoms and thus to improve the bereaved persons’ wellbeing in the long run.

Keywords: anxiety, complicated grief, depressive symptoms, hope, structural equational modeling

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4034 The Influence of Mycelium Species and Incubation Protocols on Heat and Moisture Transfer Properties of Mycelium-Based Composites

Authors: Daniel Monsalve, Takafumi Noguchi

Abstract:

Mycelium-based composites (MBC) are made by growing living mycelium on lignocellulosic fibres to create a porous composite material which can be lightweight, and biodegradable, making them suitable as a sustainable thermal insulation. Thus, they can help to reduce material extraction while improving the energy efficiency of buildings, especially when agricultural by-products are used. However, as MBC are hygroscopic materials, moisture can reduce their thermal insulation efficiency. It is known that surface growth, or “mycelium skin”, can form a natural coating due to the hydrophobic properties in the mycelium cell wall. Therefore, this research aims to biofabricate a homogeneous mycelium skin and measure its influence on the final composite material by testing material properties such as thermal conductivity, vapour permeability and water absorption by partial immersion over 24 hours. In addition, porosity, surface morphology and chemical composition were also analyzed. The white-rot fungi species Pleurotus ostreatus, Ganoderma lucidum, and Trametes versicolor were grown on 10 mm hemp fibres (Cannabis sativa), and three different biofabrication protocols were used during incubation, varying the time and surface treatment, including the addition of pre-colonised sawdust. The results indicate that density can be reduced by colonisation time, which will favourably impact thermal conductivity but will negatively affect vapour and liquid water control. Additionally, different fungi can exhibit different resistance to prolonged water absorption, and due to osmotic sensitivity, mycelium skin may also diminish moisture control. Finally, a collapse in the mycelium network after water immersion was observed through SEM, indicating how the microstructure is affected, which is also dependent on fungi species and the type of skin achieved. These results help to comprehend the differences and limitations of three of the most common species used for MBC fabrication and how precise engineering is needed to effectively control the material output.

Keywords: mycelium, thermal conductivity, vapor permeability, water absorption

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4033 Polymer-Layered Gold Nanoparticles: Preparation, Properties and Uses of a New Class of Materials

Authors: S. M. Chabane sari S. Zargou, A.R. Senoudi, F. Benmouna

Abstract:

Immobilization of nano particles (NPs) is the subject of numerous studies pertaining to the design of polymer nano composites, supported catalysts, bioactive colloidal crystals, inverse opals for novel optical materials, latex templated-hollow inorganic capsules, immunodiagnostic assays; “Pickering” emulsion polymerization for making latex particles and film-forming composites or Janus particles; chemo- and biosensors, tunable plasmonic nano structures, hybrid porous monoliths for separation science and technology, biocidal polymer/metal nano particle composite coatings, and so on. Particularly, in the recent years, the literature has witnessed an impressive progress of investigations on polymer coatings, grafts and particles as supports for anchoring nano particles. This is actually due to several factors: polymer chains are flexible and may contain a variety of functional groups that are able to efficiently immobilize nano particles and their precursors by dispersive or van der Waals, electrostatic, hydrogen or covalent bonds. We review methods to prepare polymer-immobilized nano particles through a plethora of strategies in view of developing systems for separation, sensing, extraction and catalysis. The emphasis is on methods to provide (i) polymer brushes and grafts; (ii) monoliths and porous polymer systems; (iii) natural polymers and (iv) conjugated polymers as platforms for anchoring nano particles. The latter range from soft bio macromolecular species (proteins, DNA) to metallic, C60, semiconductor and oxide nano particles; they can be attached through electrostatic interactions or covalent bonding. It is very clear that physicochemical properties of polymers (e.g. sensing and separation) are enhanced by anchored nano particles, while polymers provide excellent platforms for dispersing nano particles for e.g. high catalytic performances. We thus anticipate that the synergetic role of polymeric supports and anchored particles will increasingly be exploited in view of designing unique hybrid systems with unprecedented properties.

Keywords: gold, layer, polymer, macromolecular

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4032 Effect of Oxygen Ion Irradiation on the Structural, Spectral and Optical Properties of L-Arginine Acetate Single Crystals

Authors: N. Renuka, R. Ramesh Babu, N. Vijayan

Abstract:

Ion beams play a significant role in the process of tuning the properties of materials. Based on the radiation behavior, the engineering materials are categorized into two different types. The first one comprises organic solids which are sensitive to the energy deposited in their electronic system and the second one comprises metals which are insensitive to the energy deposited in their electronic system. However, exposure to swift heavy ions alters this general behavior. Depending on the mass, kinetic energy and nuclear charge, an ion can produce modifications within a thin surface layer or it can penetrate deeply to produce long and narrow distorted area along its path. When a high energetic ion beam impinges on a material, it causes two different types of changes in the material due to the columbic interaction between the target atom and the energetic ion beam: (i) inelastic collisions of the energetic ion with the atomic electrons of the material; and (ii) elastic scattering from the nuclei of the atoms of the material, which is extremely responsible for relocating the atoms of matter from their lattice position. The exposure of the heavy ions renders the material return to equilibrium state during which the material undergoes surface and bulk modifications which depends on the mass of the projectile ion, physical properties of the target material, its energy, and beam dimension. It is well established that electronic stopping power plays a major role in the defect creation mechanism provided it exceeds a threshold which strongly depends on the nature of the target material. There are reports available on heavy ion irradiation especially on crystalline materials to tune their physical and chemical properties. L-Arginine Acetate [LAA] is a potential semi-organic nonlinear optical crystal and its optical, mechanical and thermal properties have already been reported The main objective of the present work is to enhance or tune the structural and optical properties of LAA single crystals by heavy ion irradiation. In the present study, a potential nonlinear optical single crystal, L-arginine acetate (LAA) was grown by slow evaporation solution growth technique. The grown LAA single crystal was irradiated with oxygen ions at the dose rate of 600 krad and 1M rad in order to tune the structural and optical properties. The structural properties of pristine and oxygen ions irradiated LAA single crystals were studied using Powder X- ray diffraction and Fourier Transform Infrared spectral studies which reveal the structural changes that are generated due to irradiation. Optical behavior of pristine and oxygen ions irradiated crystals is studied by UV-Vis-NIR and photoluminescence analyses. From this investigation we can concluded that oxygen ions irradiation modifies the structural and optical properties of LAA single crystals.

Keywords: heavy ion irradiation, NLO single crystal, photoluminescence, X-ray diffractometer

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4031 The Mediatory Role of Innovation in the Link between Social and Financial Performance

Authors: Bita Mashayekhi, Amin Jahangard, Milad Samavat, Saeid Homayoun

Abstract:

In the modern competitive business environment, one cannot overstate the importance of corporate social responsibility. The controversial link between the social and financial performance of firms has become a topic of interest for scholars. Hence, this study examines the social and financial performance link by taking into account the mediating role of innovation performance. We conducted the Covariance-based Structural Equation Modeling (CB-SEM) method on an international sample of firms provided by the ASSET4 database. In this research, to explore the black box of the social and financial performance relationship, we first examined the effect of social performance separately on financial performance and innovation; then, we measured the mediation role of innovation in the social and financial performance link. While our results indicate the positive effect of social performance on financial performance and innovation, we cannot document the positive mediating role of innovation. This possibly relates to the long-term nature of benefits from investments in innovation.

Keywords: ESG, financial performance, innovation, social performance, structural equation modeling

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4030 Reliability Analysis of Glass Epoxy Composite Plate under Low Velocity

Authors: Shivdayal Patel, Suhail Ahmad

Abstract:

Safety assurance and failure prediction of composite material component of an offshore structure due to low velocity impact is essential for associated risk assessment. It is important to incorporate uncertainties associated with material properties and load due to an impact. Likelihood of this hazard causing a chain of failure events plays an important role in risk assessment. The material properties of composites mostly exhibit a scatter due to their in-homogeneity and anisotropic characteristics, brittleness of the matrix and fiber and manufacturing defects. In fact, the probability of occurrence of such a scenario is due to large uncertainties arising in the system. Probabilistic finite element analysis of composite plates due to low-velocity impact is carried out considering uncertainties of material properties and initial impact velocity. Impact-induced damage of composite plate is a probabilistic phenomenon due to a wide range of uncertainties arising in material and loading behavior. A typical failure crack initiates and propagates further into the interface causing de-lamination between dissimilar plies. Since individual crack in the ply is difficult to track. The progressive damage model is implemented in the FE code by a user-defined material subroutine (VUMAT) to overcome these problems. The limit state function is accordingly established while the stresses in the lamina are such that the limit state function (g(x)>0). The Gaussian process response surface method is presently adopted to determine the probability of failure. A comparative study is also carried out for different combination of impactor masses and velocities. The sensitivity based probabilistic design optimization procedure is investigated to achieve better strength and lighter weight of composite structures. Chain of failure events due to different modes of failure is considered to estimate the consequences of failure scenario. Frequencies of occurrence of specific impact hazards yield the expected risk due to economic loss.

Keywords: composites, damage propagation, low velocity impact, probability of failure, uncertainty modeling

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4029 Theoretical and Experimental Study of Iron Oxide Thin Film

Authors: Fahima Djefaflia, M. Loutfi Benkhedir

Abstract:

The aim of this work was to development and characterisation of iron oxide thin films by spray pyrolysis technique. Influences of deposition parameters pile temperature on structural and optical properties have been studied Thin films are analysed by various techniques of materials. The structural characterization of films by analysis of spectra of X-ray diffraction showed that the films prepared at T=350,400,450 are crystalline and amorphous at T=300C. For particular condition, two phases hematiteFe2O3 and magnetite Fe3O4 have been observed.The UV-Visible spectrophotometer of this films confirms that it is possible to obtain films with a transmittance of about 15-30% in the visible range. In addition, this analysis allowed us to determine the optical gap and disorder of films. We conclude that the increase in temperature is accompanied by a reduction in the optical gap with increasing in disorder. An ab initio calculation for this phase shows that the results are in good agreement with the experimental results.

Keywords: spray pyrolysis technique, iron oxide, ab initio calculation, optical properties

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4028 Unveiling the Domino Effect: Barriers and Strategies in the Adoption of Telecommuting as a Post-Pandemic Workspace

Authors: Divnesh Lingam, Devi Rengamani Seenivasagam, Prashant Chand, Caleb Yee, John Chief, Rajeshkannan Ananthanarayanan

Abstract:

Telecommuting Post-Pandemic: Barriers, Solutions, and Strategies. Amidst the COVID-19 outbreak in 2020, remote work emerged as a vital business continuity measure. This study investigates telecommuting’s modern work model, exploring its benefits and obstacles. Utilizing Interpretive Structural Modelling uncovers barriers hindering telecommuting adoption. A validated set of thirteen barriers is examined through departmental surveys, revealing interrelationships. The resulting model highlights interactions and dependencies, forming a foundational framework. By addressing dominant barriers, a domino effect on subservient barriers is demonstrated. This research fosters further exploration, proposing management strategies for successful telecommuting adoption and reshaping the traditional workspace.

Keywords: barriers, interpretive structural modelling, post-pandemic, telecommuting

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4027 Modern Well Logs Technology to Improve Geological Model for Libyan Deep Sand Stone Reservoir

Authors: Tarek S. Duzan, Fisal Ben Ammer, Mohamed Sula

Abstract:

In some places within Sirt Basin-Libya, it has been noticed that seismic data below pre-upper cretaceous unconformity (PUK) is hopeless to resolve the large-scale structural features and is unable to fully determine reservoir delineation. Seismic artifacts (multiples) are observed in the reservoir zone (Nubian Formation) below PUK, which complicate the process of seismic interpretation. The nature of the unconformity and the structures below are still ambiguous and not fully understood which generates a significant gap in characterizing the geometry of the reservoir, the uncertainty accompanied with lack of reliable seismic data creates difficulties in building a robust geological model. High resolution dipmeter is highly useful in steeply dipping zones. This paper uses FMl and OBMl borehole images (dipmeter) to analyze the structures below the PUK unconformity from two wells drilled recently in the North Gialo field (a mature reservoir). In addition, borehole images introduce new evidences that the PUK unconformity is angular and the bedding planes within the Nubian formation (below PUK) are significantly titled. Structural dips extracted from high resolution borehole images are used to construct a new geological model by the utilization of latest software technology. Therefore, it is important to use the advance well logs technology such as FMI-HD for any future drilling and up-date the existing model in order to minimize the structural uncertainty.

Keywords: FMI (formation micro imager), OBMI (oil base mud imager), UBI (ultra sonic borehole imager), nub sandstone reservoir in North gialo

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4026 Charged Amphiphilic Polypeptide Based Micelle Hydrogel Composite for Dual Drug Release

Authors: Monika Patel, Kazuaki Matsumura

Abstract:

Synthetic hydrogels, with their unique properties such as porosity, strength, and swelling in aqueous environment, are being used in many fields from food additives to regenerative medicines, from diagnostic and pharmaceuticals to drug delivery systems (DDS). But, hydrogels also have some limitations in terms of homogeneity of drug distribution and quantity of loaded drugs. As an alternate, polymeric micelles are extensively used as DDS. With the ease of self-assembly, and distinct stability they remarkably improve the solubility of hydrophobic drugs. However, presently, combinational therapy is the need of time and so are systems which are capable of releasing more than one drug. And it is one of the major challenges towards DDS to control the release of each drug independently, which simple DDS cannot meet. In this work, we present an amphiphilic polypeptide based micelle hydrogel composite to study the dual drug release for wound healing purposes using Amphotericin B (AmpB) and Curcumin as model drugs. Firstly, two differently charged amphiphilic polypeptide chains were prepared namely, poly L-Lysine-b-poly phenyl alanine (PLL-PPA) and poly Glutamic acid-b-poly phenyl alanine (PGA-PPA) through ring opening polymerization of amino acid N-carboxyanhydride. These polymers readily self-assemble to form micelles with hydrophobic PPA block as core and hydrophilic PLL/PGA as shell with an average diameter of about 280nm. The thus formed micelles were loaded with the model drugs. The PLL-PPA micelle was loaded with curcumin and PGA-PPA was loaded with AmpB by dialysis method. Drug loaded micelles showed a slight increase in the mean diameter and were fairly stable in solution and lyophilized forms. For forming the micelles hydrogel composite, the drug loaded micelles were dissolved and were cross linked using genipin. Genipin uses the free –NH2 groups in the PLL-PPA micelles to form a hydrogel network with free PGA-PPA micelles trapped in between the 3D scaffold formed. Different composites were tested by changing the weight ratios of the both micelles and were seen to alter its resulting surface charge from positive to negative with increase in PGA-PPA ratio. The composites with high surface charge showed a burst release of drug in initial phase, were as the composites with relatively low net charge showed a sustained release. Thus the resultant surface charge of the composite can be tuned to tune its drug release profile. Also, while studying the degree of cross linking among the PLL-PPA particles for effect on dual drug release, it was seen that as the degree of crosslinking increases, an increase in the tendency to burst release the drug (AmpB) is seen in PGA-PPA particle, were as on the contrary the PLL-PPA particles showed a slower release of Curcumin with increasing the cross linking density. Thus, two different pharmacokinetic profile of drugs were seen by changing the cross linking degree. In conclusion, a unique charged amphiphilic polypeptide based micelle hydrogel composite for dual drug delivery. This composite can be finely tuned on the basis of need of drug release profiles by changing simple parameters such as composition, cross linking and pH.

Keywords: amphiphilic polypeptide, dual drug release, micelle hydrogel composite, tunable DDS

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4025 Structural Evidence of the Conversion of Nitric Oxide (NO) to Nitrite Ion (NO2‾) by Lactoperoxidase (LPO): Structure of the Complex of LPO with NO2‾ at 1.89å Resolution

Authors: V. Viswanathan, Md. Irshad Ahmad, Prashant K. Singh, Nayeem Ahmad, Pradeep Sharma, Sujata Sharma, Tej P Singh

Abstract:

Lactoperoxidase (LPO) is a heme containing mammalian enzyme which uses hydrogen peroxide (H2O2) to catalyze the conversion of substrates into oxidized products. LPO is found in body fluids and tissues such as milk, saliva, tears, mucosa and other body secretions. The previous structural studies have shown that LPO converts substrates, thiocyanate (SCN‾) and iodide (I‾) ions into oxidized products, hypothiocyanite (OSCN‾) and hypoiodite (IO‾) ions, respectively. We report here a new structure of the complex of LPO with an oxidized product, nitrite (NO2‾). This product was generated from NO using the two step reaction of LPO by adding hydrogen peroxide (H2O2) in the solution of LPO in 0.1M phosphate buffer at pH 6.8 as the first step. In the second step, NO gas was added to the above mixture. This was crystallized using 20% (w/v) PEG-3350 and 0.2M ammonium iodide at pH 6.8. The structure determination showed the presence of NO2‾ ion in the distal heme cavity of the substrate binding site of LPO. The structure also showed that the propionate group, which is linked to pyrrole ring D of the heme moiety, was disordered. Similarly, the side chain of Asp108, which is covalently linked to heme moiety, was also split into two components. As a result of these changes, the conformation of the side chain of Arg255 was altered, allowing it to form new interactions with the disordered carboxylic group of propionate moiety. These structural changes are indicative of an intermediate state in the catalytic reaction pathway of LPO.

Keywords: lactoperoxidase, structure, nitric oxide, nitrite ion, intermediate, complex

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4024 Galtung’s Violence Triangle: We Need to Be Thinking Upside Down

Authors: Michael Fusi Ligaliga

Abstract:

Peace and Conflict Studies (PACS), despite being a new pedagogical discipline, is a growing interdisciplinary academic field that has expanded its presence from the traditional lens of war, conflict, and violence to addressing various social issues impacting society. Family and domestic violence (FDV) has seldom been explored through the PACS lens despite some studies showing that “on average, nearly 20 people per minute are physically abused by an intimate partner in the United States. Over one year, this equates to more than 10 million women and men.” In the Pacific, FDV rates are some of the highest in the world. The friction caused by cultural practices reinforcing patriarchy and male impunity, compounded by historical colonial experiences, as well as the impact of Christianity on the Pacific region, creates a complex social landscape when thinking about and addressing FDV in the Pacific. This paper seeks to re-examine Johan Galtung’s violence triangle (GVT) theory and its application to understanding FDV in the Pacific. Galtung argues that there are three forms of violence – direct, structural, and cultural. Direct violence (DV) is behaviors that threaten life itself or diminishes the ability of a person to meet his or her basic needs. This form of violence is visible because it is manifested in behaviors such as killing, maiming, sexual assault, etc. Structural violence (SV) exists when people do not get equal access to goods and services (health, education, justice) that enable them to reach their full potential. When ideologies embedded in cultural norms and practices are used to justify and advocate acts of violence by shifting the moral parameters from being wrong to right or acceptable, this, according to Galtung, is referred to as Cultural violence (CV).

Keywords: direct violence, cultural violence, structural violence, indigenous peacebuilding, samoa

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4023 Seismic Interpretation and Petrophysical Evaluation of SM Field, Libya

Authors: Abdalla Abdelnabi, Yousf Abushalah

Abstract:

The G Formation is a major gas producing reservoir in the SM Field, eastern, Libya. It is called G limestone because it consists of shallow marine limestone. Well data and 3D-Seismic in conjunction with the results of a previous study were used to delineate the hydrocarbon reservoir of Middle Eocene G-Formation of SM Field area. The data include three-dimensional seismic data acquired in 2009. It covers approximately an area of 75 mi² and with more than 9 wells penetrating the reservoir. Seismic data are used to identify any stratigraphic and structural and features such as channels and faults and which may play a significant role in hydrocarbon traps. The well data are used to calculation petrophysical analysis of S field. The average porosity of the Middle Eocene G Formation is very good with porosity reaching 24% especially around well W 6. Average water saturation was calculated for each well from porosity and resistivity logs using Archie’s formula. The average water saturation for the whole well is 25%. Structural mapping of top and bottom of Middle Eocene G formation revealed the highest area in the SM field is at 4800 ft subsea around wells W4, W5, W6, and W7 and the deepest point is at 4950 ft subsea. Correlation between wells using well data and structural maps created from seismic data revealed that net thickness of G Formation range from 0 ft in the north part of the field to 235 ft in southwest and south part of the field. The gas water contact is found at 4860 ft using the resistivity log. The net isopach map using both the trapezoidal and pyramid rules are used to calculate the total bulk volume. The original gas in place and the recoverable gas were calculated volumetrically to be 890 Billion Standard Cubic Feet (BSCF) and 630 (BSCF) respectively.

Keywords: 3D seismic data, well logging, petrel, kingdom suite

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4022 Characterization of Bio-Inspired Thermoelastoplastic Composites Filled with Modified Cellulose Fibers

Authors: S. Cichosz, A. Masek

Abstract:

A new cellulose hybrid modification approach, which is undoubtedly a scientific novelty, is introduced. The study reports the properties of cellulose (Arbocel UFC100 – Ultra Fine Cellulose) and characterizes cellulose filled polymer composites based on an ethylene-norbornene copolymer (TOPAS Elastomer E-140). Moreover, the approach of physicochemical two-stage cellulose treatment is introduced: solvent exchange (to ethanol or hexane) and further chemical modification with maleic anhydride (MA). Furthermore, the impact of the drying process on cellulose properties was investigated. Suitable measurements were carried out to characterize cellulose fibers: spectroscopic investigation (Fourier Transform Infrared Spektrofotometer-FTIR, Near InfraRed spectroscopy-NIR), thermal analysis (Differential scanning calorimetry, Thermal gravimetric analysis ) and Karl Fischer titration. It should be emphasized that for all UFC100 treatments carried out, a decrease in moisture content was evidenced. FT-IR reveals a drop in absorption band intensity at 3334 cm-1, the peak is associated with both –OH moieties and water. Similar results were obtained with Karl Fischer titration. Based on the results obtained, it may be claimed that the employment of ethanol contributes greatly to the lowering of cellulose water absorption ability (decrease of moisture content to approximately 1.65%). Additionally, regarding polymer composite properties, crucial data has been obtained from the mechanical and thermal analysis. The highest material performance was noted in the case of the composite sample that contained cellulose modified with MA after a solvent exchange with ethanol. This specimen exhibited sufficient tensile strength, which is almost the same as that of the neat polymer matrix – in the region of 40 MPa. Moreover, both the Payne effect and filler efficiency factor, calculated based on dynamic mechanical analysis (DMA), reveal the possibility of the filler having a reinforcing nature. What is also interesting is that, according to the Payne effect results, fibers dried before the further chemical modification are assumed to allow more regular filler structure development in the polymer matrix (Payne effect maximum at 1.60 MPa), compared with those not dried (Payne effect in the range 0.84-1.26 MPa). Furthermore, taking into consideration the data gathered from DSC and TGA, higher thermal stability is obtained in case of the materials filled with fibers that were dried before the carried out treatments (degradation activation energy in the region of 195 kJ/mol) in comparison with the polymer composite samples filled with unmodified cellulose (degradation activation energy of approximately 180 kJ/mol). To author’s best knowledge this work results in the introduction of a novel, new filler hybrid treatment approach. Moreover, valuable data regarding the properties of composites filled with cellulose fibers of various moisture contents have been provided. It should be emphasized that plant fiber-based polymer bio-materials described in this research might contribute significantly to polymer waste minimization because they are more readily degraded.

Keywords: cellulose fibers, solvent exchange, moisture content, ethylene-norbornene copolymer

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4021 Physical Properties of Uranium Dinitride UN2 by Using Density Functional Theory (DFT and DFT+U)

Authors: T. Zergoug, S. E. H. Abaidia, A. Nedjar, M. Y. Mokeddem

Abstract:

Physical properties of uranium di-nitride (UN2) were investigated in detail using first principles calculations based on density functional theory. To treat the strong correlation effects caused by 5f Uranium valence electrons, on-site Coulomb interaction correction via the Hubbard-like term, U (DFT+U) was employed. The UN2 structural, mechanical and thermodynamic properties were calculated within DFT and Various U of DFT+U approach. The Perdew–Burke–Ernzerhof (PBE.5.2) version of the generalized gradient approximation (GGA) is used to describe the exchange-correlation with the projector-augmented wave (PAW) pseudo potentials. A comparative study shows that results are improved by using the Hubbard formalism for a certain U value correction like the structural parameter. For some physical properties the variation versus Hubbard U is strong like Young modulus but for others it is weakly noticeable such as the density of state (DOS) or bulk modulus. We noticed also that up from U=7.5 eV, elastic results become not conform to the cubic cell elastic criteria since the C44 values turn out to be negative.

Keywords: uranium diNitride, UN2, DFT+U, elastic properties

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4020 Impact Assessment of Lean Practices on Social Sustainability Indicators: An Approach Using ISM Method

Authors: Aline F. Marcon, Eduardo F. da Silva, Marina Bouzon

Abstract:

The impact of lean management on environmental sustainability is the research line that receives the most attention from academicians. Therefore, the social dimension of sustainable development has so far received less attention. This paper aims to evaluate the impact of intra-plant lean manufacturing practices on social sustainability indicators extracted from the Global Reporting Initiative (GRI) parameters. The method is two-phased, including MCDM approach to uncover the most relevant practices regarding social performance and Interpretive Structural Modeling (ISM) method to reveal the structural relationship among lean practices. Professionals from the academic and industrial fields answered the questionnaires. From the results of this paper, it is possible to verify that practices such as “Safety Improvement Programs”, “Total Quality Management” and “Cross-functional Workforce” are the ones which have the most positive influence on the set of GRI social indicators.

Keywords: indicators, ISM, lean, social, sustainability

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4019 Factors Influencing the Resistance of the Purchase of Organic Food and Market Education Process in Indonesia

Authors: Fety Nurlia Muzayanah, Arif Imam Suroso, Mukhamad Najib

Abstract:

The market share of organic food in Indonesia just reaches 0.5-2 percents from the entire of agricultural products. The aim of this research is to analyze the relation of gender, work, age and final education toward the buying interest of organic food, to identify the factors influencing the resistance of the purchase of organic food, and to identify the market education process. The analysis result of Structural Equation Modeling (SEM) shows the factors causing the resistance of the purchase of organic food are the negative attitude toward organic food, the lack of affordable in range for organic food product and the lack of awareness toward organic food, while the subjective norms have no significant effect toward the buying interest. The market education process which can be done is the education about the use of the health of organic food, the organic certification and the economic value.

Keywords: market education, organic food, consumer behavior, structural equation modeling

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4018 Rhythmic Prioritisation as a Means of Compositional Organisation: Analysing Meshuggah’s “do Not Look Down”

Authors: Nicholas Freer

Abstract:

Rhythmic complexity in progressive metal is a developing area of analysis, particularly the interpretation of hyper-metric time spans as hierarchically significant rhythmic units of compositional organisation (Pieslak 2007, Charupakorn 2012, Capuzzo 2018, Calder 2018, Lucas 2018, Hannan 2020). This paper adds to this developing area by considering the relationships between the concepts of tactus, metric imposition, polymeter and rhythmic parallax in the Meshuggah composition “Do Not Look Down”. By considering an architectonic rhythmic framework within “Do Not Look Down” as the controlling organisation mechanism, an exploration of the interaction between distinct rhythmic layers and the composition’s formal segmentation and harmony (as riffs), reveals a pervasive structural misalignment between these elements. By exhibiting how Meshuggah’s manipulations of rhythmic complexities deliberately blur structural boundaries, creating misalignments in a flat approach to temporal partitioning (Nieto 2014), rhythmic characteristics of Meshuggah and the genre of Djent are exposed.

Keywords: hypermeter, rhythmic parallax, meshuggah, temporal partitioning

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4017 Exploring Women's Embodied Experiences of 'the Gaze' in Fitness Cultures

Authors: Amy Clark

Abstract:

To date, the focus of feminist research surrounding men looking at women, with the analysis of how women make sense of looks between women remains limited and scattered. Drawing upon ethnographic data obtained from an on-going research project, this presentation delves into the embodied experiences of female exercisers within a UK ‘working-class’ gym. By exploring the women’s own accounts of their living, breathing and sensing bodies as they exercise, the researcher attempts to understand how they make sense of the gym space, their embodied selves as well as broader constructions of the gendered body. Utilising a feminist phenomenological approach, this research examines the social-structural position of women in a patriarchal system of gender relations, whilst simultaneously acknowledging and analysing the structural, cultural, and historical forces and location, upon individual lived body experiences and gendered embodiment. The discussion is provided on how the gym can be identified as a sexually objectifying environment, and how women make sense and interpret specific ‘gazes’ encountered within the gym.

Keywords: embodiment, feminism, gazes, sociology

Procedia PDF Downloads 357
4016 Usage of Military Spending, Debt Servicing and Growth for Dealing with Emergency Plan of Indian External Debt

Authors: Sahbi Farhani

Abstract:

This study investigates the relationship between external debt and military spending in case of India over the period of 1970–2012. In doing so, we have applied the structural break unit root tests to examine stationarity properties of the variables. The Auto-Regressive Distributed Lag (ARDL) bounds testing approach is used to test whether cointegration exists in presence of structural breaks stemming in the series. Our results indicate the cointegration among external debt, military spending, debt servicing, and economic growth. Moreover, military spending and debt servicing add in external debt. Economic growth helps in lowering external debt. The Vector Error Correction Model (VECM) analysis and Granger causality test reveal that military spending and economic growth cause external debt. The feedback effect also exists between external debt and debt servicing in case of India.

Keywords: external debt, military spending, ARDL approach, India

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4015 Growth Mechanism, Structural and Compositional Properties of Cu₂ZnSnS₄ (CZTS) Thin Films Deposited by Sputtering Method from a Compound Target

Authors: Sanusi Abdullahi, Musa Momoh, Abubakar Umar Moreh, Aminu Muhammad Bayawa, Olubunmi Popoola

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Kesterite-type Cu₂ZnSnS₄ (CZTS) thin films were deposited on corning glass from a single quaternary target. In this study, we investigated the growth mechanism and the influence of thin film thickness on the structural and compositional properties of CZTS films. All the four samples (as-deposited inclusive) show peaks corresponding to kesterite-type structure. The diffraction peaks of (112) are sharp and the small characteristics peaks of the kesterite structure such as (220)/ (204) and (312)/ (116) are also clearly observed in X-ray diffraction pattern. These results indicate that the quaternary CZTS would be a potential candidate for solar cell applications.

Keywords: RF sputtering, Cu2ZnSnS4 thin film, annealing, growth mechanism, annealing, growth mechanism, renewable energy

Procedia PDF Downloads 372
4014 Ensemble-Based SVM Classification Approach for miRNA Prediction

Authors: Sondos M. Hammad, Sherin M. ElGokhy, Mahmoud M. Fahmy, Elsayed A. Sallam

Abstract:

In this paper, an ensemble-based Support Vector Machine (SVM) classification approach is proposed. It is used for miRNA prediction. Three problems, commonly associated with previous approaches, are alleviated. These problems arise due to impose assumptions on the secondary structural of premiRNA, imbalance between the numbers of the laboratory checked miRNAs and the pseudo-hairpins, and finally using a training data set that does not consider all the varieties of samples in different species. We aggregate the predicted outputs of three well-known SVM classifiers; namely, Triplet-SVM, Virgo and Mirident, weighted by their variant features without any structural assumptions. An additional SVM layer is used in aggregating the final output. The proposed approach is trained and then tested with balanced data sets. The results of the proposed approach outperform the three base classifiers. Improved values for the metrics of 88.88% f-score, 92.73% accuracy, 90.64% precision, 96.64% specificity, 87.2% sensitivity, and the area under the ROC curve is 0.91 are achieved.

Keywords: MiRNAs, SVM classification, ensemble algorithm, assumption problem, imbalance data

Procedia PDF Downloads 349
4013 Progressive Collapse of Cooling Towers

Authors: Esmaeil Asadzadeh, Mehtab Alam

Abstract:

Well documented records of the past failures of the structures reveals that the progressive collapse of structures is one of the major reasons for dramatic human loss and economical consequences. Progressive collapse is the failure mechanism in which the structure fails gradually due to the sudden removal of the structural elements. The sudden removal of some structural elements results in the excessive redistributed loads on the others. This sudden removal may be caused by any sudden loading resulted from local explosion, impact loading and terrorist attacks. Hyperbolic thin walled concrete shell structures being an important part of nuclear and thermal power plants are always prone to such terrorist attacks. In concrete structures, the gradual failure would take place by generation of initial cracks and its propagation in the supporting columns along with the tower shell leading to the collapse of the entire structure. In this study the mechanism of progressive collapse for such high raised towers would be simulated employing the finite element method. The aim of this study would be providing clear conceptual step-by-step descriptions of various procedures for progressive collapse analysis using commercially available finite element structural analysis software’s, with the aim that the explanations would be clear enough that they will be readily understandable and will be used by practicing engineers. The study would be carried out in the following procedures: 1. Provide explanations of modeling, simulation and analysis procedures including input screen snapshots; 2. Interpretation of the results and discussions; 3. Conclusions and recommendations.

Keywords: progressive collapse, cooling towers, finite element analysis, crack generation, reinforced concrete

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4012 Structural Strength Evaluation and Wear Prediction of Double Helix Steel Wire Ropes for Heavy Machinery

Authors: Krunal Thakar

Abstract:

Wire ropes combine high tensile strength and flexibility as compared to other general steel products. They are used in various application areas such as cranes, mining, elevators, bridges, cable cars, etc. The earliest reported use of wire ropes was for mining hoist application in 1830s. Over the period, there have been substantial advancement in the design of wire ropes for various application areas. Under operational conditions, wire ropes are subjected to varying tensile loads and bending loads resulting in material wear and eventual structural failure due to fretting fatigue. The conventional inspection methods to determine wire failure is only limited to outer wires of rope. However, till date, there is no effective mathematical model to examine the inter wire contact forces and wear characteristics. The scope of this paper is to present a computational simulation technique to evaluate inter wire contact forces and wear, which are in many cases responsible for rope failure. Two different type of ropes, IWRC-6xFi(29) and U3xSeS(48) were taken for structural strength evaluation and wear prediction. Both ropes have a double helix twisted wire profile as per JIS standards and are mainly used in cranes. CAD models of both ropes were developed in general purpose design software using in house developed formulation to generate double helix profile. Numerical simulation was done under two different load cases (a) Axial Tension and (b) Bending over Sheave. Different parameters such as stresses, contact forces, wear depth, load-elongation, etc., were investigated and compared between both ropes. Numerical simulation method facilitates the detailed investigation of inter wire contact and wear characteristics. In addition, various selection parameters like sheave diameter, rope diameter, helix angle, swaging, maximum load carrying capacity, etc., can be quickly analyzed.

Keywords: steel wire ropes, numerical simulation, material wear, structural strength, axial tension, bending over sheave

Procedia PDF Downloads 152