Search results for: roll forming

Authors: Hattie Hope Makumbe, Bhekisisa Dlamini, Frederick Tabit

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Listeria monocytogenes is one of the most important foodborne pathogens associated with ready-to-eat (RTE) food. This study investigated the incidence of Listeria monocytogenes in 80 RTE food sold in the formal (dairy and processed meat) and informal markets (vegetable salads, beef stew, and rice) of Johannesburg, South Africa. High Enterobacteriaceae, S. aureus, and E. coli counts were obtained, which ranged from 1.9-7.5 log CFU/g. Listeria monocytogenes microbial counts in the food samples ranged from 3.5-6.0 log colony forming unit per gram except in cooked rice. The Listeria monocytogenes isolates were identified using biochemical tests and confirmed with the Biolog identification system and PCR analyses. The percentage incidence for Listeria monocytogenes in ready to eat food was 12.5%. When Minimum Inhibitory Concentrations were under consideration, all disinfectants were effective against Listeria monocytogenes strains. For antimicrobial work, rates of resistance amongst the antibiotics ranged from 17-100%. Therefore, more effective preventive control strategies for Listeria monocytogenes are needed to reduce the prevalence of the pathogen in RTE food that is sold in Johannesburg.

Keywords: Listeria monocytogenes, Listeria species, ready to eat food, sanitiser efficacy

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Authors: Phanwipa Pangsri, Yawariyah Weahayee

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The lactic acid bacteria (LAB) were isolated from 10 samples of fermented foods (Sa-tor-dong and Bodo) in South locality of Thailand. The 23 isolates of lactic acid bacteria were selected, which were exhibited a clear zone and growth on MRS agar supplemented with CaCO3. All of lactic acid bacteria were tested on morphological and biochemical. The result showed that all isolates were Gram’s positive, non-spore forming but only 10 isolates displayed catalase negative. The 10 isolates including BD 1.1, BD 1.2, BD 2.1, BD2.2, BD 2.3, BD 3.1, BD 4.1, BD 5.2, ST4.1, and ST 5.2 were selected for inhibition activity determination. Only 2 strains (ST 4.1 and BD 2.3) showed inhibition zone on agar, when using Escherichia coli sp. as target strain. The ST 4.1 showed highest inhibition zone on agar, which was selected for probiotic property testing. The ST4.1 isolate could grow in MRS broth containing a high concentration of sodium chloride 6%, bile salts 7%, pH 4-10 and vary temperature at 15-45^oC.

Keywords: lactic acid bacteria, probiotic, antimicrobial, probiotic property testing

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Authors: A-Q. Nguyen. A. Amrhar, J. Zambrano, G. Brown, O.A. Yeste-Ojeda, R. Jr. Landry

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Since the presence of Next Generation Air Transportation System (NextGen), Automatic Dependent Surveillance-Broadcast (ADS-B) has raised specific concerns related to the privacy and security, due to its vulnerable, low-level of security and limited payload. In this paper, the authors introduce and analyze the combination of Pulse Amplitude Modulation (PAM) and Phase Shift Keying (PSK) Modulation in conventional ADS-B, forming Secure ADS-B (SADS-B) avionics. In order to demonstrate the potential of this combination, Hardware-in-the-loop (HIL) simulation was used. The tests' results show that, on the one hand, SADS-B can offer five times the payload as its predecessor. This additional payload of SADS-B can be used in various applications, therefore enhancing the ability and efficiency of the current ADS-B. On the other hand, by using the extra phase modulated bits as a digital signature to authenticate ADS-B messages, SADS-B can increase the security of ADS-B, thus ensure a more secure aviation as well. More importantly, SADS-B is compatible with the current ADS-B In and Out. Hence, no significant modifications will be needed to implement this idea. As a result, SADS-B can be considered the most promising approach to enhance the capability and security of ADS-B.

Keywords: ADS-B authentication, ADS-B security, NextGen ADS-B, PSK signature, secure ADS-B

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Authors: Dominique Arrouays, Songchao Chen, Anne C. Richer-De-Forges

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Soils are at the crossing of many issues such as food and water security, sustainable energy, climate change mitigation and adaptation, biodiversity protection, human health and well-being. They deliver many ecosystem services that are essential to life on Earth. Therefore, there is a growing demand for soil information on a national and global scale. Unfortunately, many countries do not have detailed soil maps, and, when existing, these maps are generally based on more or less complex and often non-harmonized soil classifications. An estimate of their uncertainty is also often missing. Thus, there are not easy to understand and often not properly used by end-users. Therefore, there is an urgent need to provide end-users with spatially exhaustive grids of essential soil properties, together with an estimate of their uncertainty. One way to achieve this is digital soil mapping (DSM). The concept of DSM relies on the hypothesis that soils and their properties are not randomly distributed, but that they depend on the main soil-forming factors that are climate, organisms, relief, parent material, time (age), and position in space. All these forming factors can be approximated using several exhaustive spatial products such as climatic grids, remote sensing products or vegetation maps, digital elevation models, geological or lithological maps, spatial coordinates of soil information, etc. Thus, DSM generally relies on models calibrated with existing observed soil data (point observations or maps) and so-called “ancillary co-variates” that come from other available spatial products. Then the model is generalized on grids where soil parameters are unknown in order to predict them, and the prediction performances are validated using various methods. With the growing demand for soil information at a national and global scale and the increase of available spatial co-variates national and continental DSM initiatives are continuously increasing. This short review illustrates the main national and continental advances in Europe, the diversity of the approaches and the databases that are used, the validation techniques and the main scientific and other issues. Examples from several countries illustrate the variety of products that were delivered during the last ten years. The scientific production on this topic is continuously increasing and new models and approaches are developed at an incredible speed. Most of the digital soil mapping (DSM) products rely mainly on machine learning (ML) prediction models and/or the use or pedotransfer functions (PTF) in which calibration data come from soil analyses performed in labs or for existing conventional maps. However, some scientific issues remain to be solved and also political and legal ones related, for instance, to data sharing and to different laws in different countries. Other issues related to communication to end-users and education, especially on the use of uncertainty. Overall, the progress is very important and the willingness of institutes and countries to join their efforts is increasing. Harmonization issues are still remaining, mainly due to differences in classifications or in laboratory standards between countries. However numerous initiatives are ongoing at the EU level and also at the global level. All these progress are scientifically stimulating and also promissing to provide tools to improve and monitor soil quality in countries, EU and at the global level.

Keywords: digital soil mapping, global soil mapping, national and European initiatives, global soil mapping products, mini-review

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Authors: Ali Bayram, Burak Uz, Remzi Yiğiter

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The impairment of lipid metabolism in the central nervous system has been suggested as a critical factor of Alzheimer’s disease (AD) pathogenesis. Homo sapiens acyl-coenyme A synthetase short-chain family member 2 (ACSS2) gene encodes the enzyme acetyl-Coenzyme A synthetase (AMP forming; AceCS) providing acetyl-coenzyme A (Ac-CoA) for various physiological processes, such as cholesterol and fatty acid synthesis, as well as the citric acid cycle. We investigated ACSS2, transcript variant 1 (ACSS2*1), mRNA levels in the peripheral blood mononuclear cells (PBMC) of patients with AD and compared them with the controls. The study group comprised 50 patients with the diagnosis of AD who have applied to Gaziantep University Faculty of Medicine, and Department of Neurology. 49 healthy individuals without any neurodegenerative disease are included as controls. ACSS2 mRNA expression in PBMC of AD/control patients was 0.495 (95% confidence interval: 0.410-0.598), p= .000000001902). Further studies are needed to better clarify this association.

Keywords: Alzheimer’s disease, ACSS2 Genes, mRNA expression, RT-PCR

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Authors: Hasan Muslemani, Xi Liang, Kathi Kaesehage, Francisco Ascui, Jeffrey Wilson

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The creation of a market for lower-carbon steel products, here called ‘green steel’, has been identified as an important means to support the introduction of breakthrough emission reduction technologies into the steel sector. However, the definition of what ‘green’ entails in the context of steel production, the implications on the competitiveness of green steel products in local and international markets, and the necessary market mechanisms to support their successful market penetration remain poorly explored. This paper addresses this gap by holding semi-structured interviews with international sustainability experts and commercial managers from leading steel trade associations, research institutes and steelmakers. Our findings show that there is an urgent need to establish a set of standards to define what ‘greenness’ means in the steelmaking context; standards that avoid market disruptions, unintended consequences, and opportunities for greenwashing. We also highlight that the introduction of green steel products will have implications on product competitiveness on three different levels: 1) between primary and secondary steelmaking routes, 2) with traditional, lesser green steel, and 3) with other substitutable materials (e.g. cement and plastics). This paper emphasises the need for steelmakers to adopt a transitional approach in deploying different low-carbon technologies, based on their stage of technological maturity, applicability in certain country contexts, capacity to reduce emissions over time, and the ability of the investment community to support their deployment. We further identify market mechanisms to support green steel production, including carbon border adjustments and public procurement, highlighting a need for implementing a combination of complementary policies to ensure the products’ roll-out. The study further shows that the auto industry is a likely candidate for green steel consumption, where a market would be supported by price premiums paid by willing consumers, such as those of high-end luxury vehicles.

Keywords: green steel, decarbonisation, business model innovation, market analysis

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Authors: Ximena Castillo, Jaime Pizarro

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This research describes the development of a very cheap mesoporous silica material similar to hexagonal mesoporous silica (HMS) and using a silicate extract as precursor. This precursor is obtained from cheap fly ash by an easy calcination process at 850 °C and a green extraction with water. The obtained mesoporous fly ash material had a surface area of 282 m2 g-1 and a pore size of 5.7 nm. It was functionalized with ethylene diamino moieties via the well-known SAMMS method, followed by a DRIFT analysis that clearly showed the successful functionalization. An excellent adsorbent was obtained for the adsorption of sulfate anions by the solid’s modification with copper forming a copper-ethylenediamine complex. The adsorption of sulfates was studied in a batch system ( experimental conditions: pH=8.0; 5 min). The kinetics data were adjusted according to a pseudo-second order model with a high coefficient of linear regression at different initial concentrations. The adsorption isotherm that best fitted the experimental data was the Freundlich model. The maximum sulfate adsorption capacity of this very cheap fly ash based adsorbent was 146.1 mg g-1, 3 times greater than the values reported in literature and commercial adsorbent materials.

Keywords: fly ash, mesoporous materials, SAMMS, sulfate

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Authors: Carolyn B. Mires, David L. Lee, David B. McNaughton

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High school students’ with emotional and behavioral disorders (EBD) are one of the most underserved populations in today's schools. Using a multiple case study methodology, interviews were conducted to examine current practices and perceptions of the communication practices of teachers working with high school students with EBD. These interviews involved questions about general communication instances which occurred each week, communication strategies used each week, and how progress was being made on forming relationships with parents. Results confirm previous researchers’ hypotheses regarding methods, purposes, and regularity of positive communication incidences. Communication that met the positive goals of nurturing and maintaining relationships was open and frequent, reciprocal, and informal. Limitations are discussed as well as issues of trustworthiness. The case study concludes with a discussion and suggestions for high school special educators of students with EBD.

Keywords: emotional behavioral disorders, high school adolescence, home-school communication, relationships between parents and schools

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Authors: Nikhil Padhye

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Recently a new phenomenon for bonding of polymeric films in solid-state, at ambient temperatures well below the glass transition temperature of the polymer, has been reported. This is achieved by bulk plastic compression of polymeric films held in contact. Here we analyze the process of cold-rolling of polymeric films via finite element simulations and illustrate a flexible and modular experimental rolling-apparatus that can achieve bonding of polymeric films through cold-rolling. Firstly, the classical theory of rolling a rigid-plastic thin-strip is utilized to estimate various deformation fields such as strain-rates, velocities, loads etc. in rolling the polymeric films at the specified feed-rates and desired levels of thickness-reduction(s). Predicted magnitudes of slow strain-rates, particularly at ambient temperatures during rolling, and moderate levels of plastic deformation (at which Bauschinger effect can be neglected for the particular class of polymeric materials studied here), greatly simplifies the task of material modeling and allows us to deploy a computationally efficient, yet accurate, finite deformation rate-independent elastic-plastic material behavior model (with inclusion of isotropic-hardening) for analyzing the rolling of these polymeric films. The interfacial behavior between the roller and polymer surfaces is modeled using Coulombic friction; consistent with the rate-independent behavior. The finite deformation elastic-plastic material behavior based on (i) the additive decomposition of stretching tensor (D = De + Dp, i.e. a hypoelastic formulation) with incrementally objective time integration and, (ii) multiplicative decomposition of deformation gradient (F = FeFp) into elastic and plastic parts, are programmed and carried out for cold-rolling within ABAQUS Explicit. Predictions from both the formulations, i.e., hypoelastic and multiplicative decomposition, exhibit a close match. We find that no specialized hyperlastic/visco-plastic model is required to describe the behavior of the blend of polymeric films, under the conditions described here, thereby speeding up the computation process .

Keywords: Polymer Plasticity, Bonding, Deformation Induced Mobility, Rolling

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Authors: Chien Chon Chen, Chun Mei Chu, Chuan Ju Wang, Chih Yuan Chen, Ker Jer Huang

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Cesiumiodide with Na doping (CsI(Na)) solution or melt is easily forming three- dimension dendrites on the free surface. The defects or bobbles form inside the CsI(Na) during the solution or melt solidification. The defects or bobbles can further effect the x-ray path in the CsI(Na) crystal and decrease the scintillation characteristics of CsI(Na). In order to enhance the CsI(Na) scintillated property we made single crystal of CsI(Na) column in the anodic aluminum oxide (AAO) template by hydraulic pressure injection method. It is interesting that when CsI(Na) melt is confined in the small AAO channels, the column grow as stable single column without any dendrites. The high aspect ratio (100~10000) of AAO and nano to sub-micron channel structure which is a suitable template for single of crystal CsI(Na) formation. In this work, a new low-cost approach to fabricate scintillator crystals using anodic aluminum oxide (AAO) rather than Si is reported, which can produce scintillator crystals with a wide range of controllable size to optimize their performance in X-ray detection.

Keywords: cesiumiodide, AAO, scintillator, crystal, X-ray

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Authors: Stefanie Siebenhütter

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Men and women use minority and majority languages differently and with varying confidence levels. This paper contrasts gendered differences in language use with socioeconomic status and age factors of minority language speakers in Southeast Asia. Language use and competence are conditioned by the variable of gender. Potential reasons for this variation by examining gendered language awareness and sociolinguistic attitudes will be given. Moreover, it is analyzed whether women in multilingual minority speakers’ society function as 'leaders of linguistic change', as represented in Labov’s sociolinguistic model. It is asked whether the societal role expectations in collectivistic cultures influence the model of linguistic change. The findings reveal speaking preferences and suggest predictions on the prospective language use, which is a stable situation of multilingualism. The study further exhibits differences between male and females identity-forming processes and shows why females are the leaders of (socio-) linguistic change.

Keywords: gender, identity construction, multilingual minorities, linguistic change, social networks

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Authors: Serap Durkut, A. Eser Elcin, Y. Murat Elcin

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Stimuli-sensitive polymeric hydrogels have received extensive attention in the biomedical field due to their sensitivity to physical and chemical stimuli (temperature, pH, ionic strength, light, etc.). This study describes the rheological properties of a novel thermoresponsive poly(N-vinylcaprolactam)-g-collagen hydrogel. In the study, we first synthesized a facile and novel synthetic carboxyl group-terminated thermo-responsive poly(N-vinylcaprolactam)-COOH (PNVCL-COOH) via free radical polymerization. Further, this compound was effectively grafted with native collagen, by utilizing the covalent bond between the carboxylic acid groups at the end of the chains and amine groups of the collagen using cross-linking agent (EDC/NHS), forming PNVCL-g-Col. Newly-formed hybrid hydrogel displayed novel properties, such as increased mechanical strength and thermoresponsive characteristics. PNVCL-g-Col showed low critical solution temperature (LCST) at 38ºC, which is very close to the body temperature. Rheological studies determine structural–mechanical properties of the materials and serve as a valuable tool for characterizing. The rheological properties of hydrogels are described in terms of two dynamic mechanical properties: the elastic modulus G′ (also known as dynamic rigidity) representing the reversible stored energy of the system, and the viscous modulus G″, representing the irreversible energy loss. In order to characterize the PNVCL-g-Col, the rheological properties were measured in terms of the function of temperature and time during phase transition. Below the LCST, favorable interactions allowed the dissolution of the polymer in water via hydrogen bonding. At temperatures above the LCST, PNVCL molecules within PNVCL-g-Col aggregated due to dehydration, causing the hydrogel structure to become dense. When the temperature reached ~36ºC, both the G′ and G″ values crossed over. This indicates that PNVCL-g-Col underwent a sol-gel transition, forming an elastic network. Following temperature plateau at 38ºC, near human body temperature the sample displayed stable elastic network characteristics. The G′ and G″ values of the PNVCL-g-Col solutions sharply increased at 6-9 minute interval, due to rapid transformation into gel-like state and formation of elastic networks. Copolymerization with collagen leads to an increase in G′, as collagen structure contains a flexible polymer chain, which bestows its elastic properties. Elasticity of the proposed structure correlates with the number of intermolecular cross-links in the hydrogel network, increasing viscosity. However, at 8 minutes, G′ and G″ values sharply decreased for pure collagen solutions due to the decomposition of the elastic and viscose network. Complex viscosity is related to the mechanical performance and resistance opposing deformation of the hydrogel. Complex viscosity of PNVCL-g-Col hydrogel was drastically changed with temperature and the mechanical performance of PNVCL-g-Col hydrogel network increased, exhibiting lesser deformation. Rheological assessment of the novel thermo-responsive PNVCL-g-Col hydrogel, exhibited that the network has stronger mechanical properties due to both permanent stable covalent bonds and physical interactions, such as hydrogen- and hydrophobic bonds depending on temperature.

Keywords: poly(N-vinylcaprolactam)-g-collagen, thermoresponsive polymer, rheology, elastic modulus, stimuli-sensitive

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Authors: Ruqia Nazir, Robin Perutz

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Collision-induced dissociation (CID) can be used to study the intrinsic properties of ions in the gas phase.1 Decay pathways of transition metal difluoride complexes of titanium, zirconium, hafnium, and ruthenium were studied by CID in an ESI-Ion trap mass spectrometer. Furthermore, the decay pathways of multiply charged anions (MCAs) of titanium and zirconium were also studied. The CID results are illustrated by the behaviour of (Cp*)₂TiF₂, which initially forms the ions [M-F-]⁺, [M+Na]⁺, and [M+K]⁺. The [(Cp*₂)TiF⁺ ion decays on resonant excitation to lose HF forming [Cp*(C₅Me₄CH₂)Ti]⁺ (Figure). The other major ion, [(Cp*)₂TiF₂+Na]⁺, decays on resonant excitation with production of [(Cp*)₂TiF₂]⁺ and [C₅Me₄CH₂]⁺. We also report the behaviour of Cp₂MF₂ (M = Zr, Hf) and Ru(PMe₃)₄F₂. The decay pathway of the multiply charged anions (MCAs), notably TiF₆²⁻ and ZrF₆²⁻ was concluded to be ionic fragmentation with loss of F⁻ rather than electron detachment.

Keywords: collision induced dissociation, transition metal difluoride comolexes, multiply charged anions, mass spectrometry

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Authors: Shaira Karishma Sheriff, Zarinah Hamid

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The Arab Spring, which commenced during the end of 2010 and accelerated during 2011, was caused primarily due to poverty, unemployment and a general recession in the Middle East and North African (MENA) region. The core motivation of this revolution could be said to be the need for political, economic and social reforms that the region desires to experience. Though GDP growth has been significant in the region, the income distribution mechanism in MENA countries has been ineffective. This results in low levels of education, substandard health care facilities, unemployment, and poverty. This paper argues that MENA countries have great potential for experiencing socioeconomic development by being less dependent on oil exports and enhancing their services sector through better education which would eventually lead to job creation. Furthermore, the region can encourage better trade and political integration by forming transparent and accountable governments. The notion of Nation-State needs to be addressed and the countries in the region need to look for ways to develop effective supra-national institutions for better political and economic integration that goes beyond geographical borders.

Keywords: political reforms, social reforms, economic development, nation-state, economic integration

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Authors: Clarissa Delariarte

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With the aim of helping the poorest of the poor achieve quality education, Psychology students supported and served as teacher assistants to its Early Childhood Education Center in two barangays since the program began in 1999. Making use of qualitative approach, the impact of the program to 29 alumni who served as teacher assistants between 2000-2014 was assessed. Results show that the impact to the alumni is in cognitive as well as social-emotional in terms of feelings of deep satisfaction and sense of volunteerism which is being carried out in their respective workspaces. They also expressed positive feelings of inspiration, gratefulness and happiness. A wider perspective in life, being confident, creative and resourceful was also articulated as concrete impacts. It is concluded that the program had an impact on helping the helper and is a concrete manifestation of the academe being successful in its commitment of forming individuals into becoming integrated and compassionate in the service of the Church and Society. It implies that more opportunities of helping others be provided to students since, in the final analysis, is actually an opportunity of helping the helper be of better service to others.

Keywords: applied psychology, life skill, qualitative research, quality education

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Authors: Bernd Engel, Hassan Raheem Hassan

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Rotary draw bending is a method used for tube forming. During the tube bending process, the neutral axis moves towards the inner arc and the wall thickness changes in the cross section of the tube. Wall thinning of the tube takes place at the extrados, whereas wall thickening of the tube occurs at the intrados. This paper investigates the tube bending with rotary draw bending process using thick-walled tubes and different material properties (16Mo3 and 10CrMo9-10). The experimental tests and finite element simulations are used to calculate the variable characteristics (wall thickness distribution, neutral axis shifting and longitudinal strain distribution). These results are compared with results of a plasto-mechanical model. Moreover, the cross section distortion is investigated in this study. This study helped to get bends with smaller wall factor for different material properties.

Keywords: rotary draw bending, thick wall tube, material properties, material influence

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Authors: Ahmed H. Abdullah, Pavel Kroupa

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Globular clusters (GC) are important objects for tracing the early evolution of a galaxy. We study the correlation between the cluster population and the global properties of the host galaxy. We found that the correlation between cluster population (NGC) and the baryonic mass (Mb) of the host galaxy are best described as 10 −5.6038Mb. In order to understand the origin of the U -shape relation between the GC specific frequency (SN) and Mb (caused by the high value of SN for dwarfs galaxies and giant ellipticals and a minimum SN for intermediate mass galaxies≈ 1010M), we derive a theoretical model for the specific frequency (SNth). The theoretical model for SNth is based on the slope of the power-law embedded cluster mass function (β) and different time scale (Δt) of the forming galaxy. Our results show a good agreement between the observation and the model at a certain β and Δt. The model seems able to reproduce higher value of SNth of β = 1.5 at the midst formation time scale.

Keywords: galaxies: dwarf, globular cluster: specific frequency, number of globular clusters, formation time scale

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Authors: Napat Hataivichian

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The effect of transition metal doping on Pt/Al2O3 catalyst used in propane dehydrogenation reaction at 500˚C was studied. The preparation methods investigated were sequential impregnation (Pt followed by the 2nd metal or the 2nd metal followed by Pt) and co-impregnation. The metal contents of these catalysts were fixed as the weight ratio of Pt per the 2nd metal of around 0.075. These catalysts were characterized by N2-physisorption, TPR, CO-chemisorption and NH3-TPD. It was found that the impregnated 2nd metal had an effect upon reducibility of Pt due to its interaction with transition metal-containing structure. This was in agreement with the CO-chemisorption result that the presence of Pt metal, which is a result from Pt species reduction, was decreased. The total acidity of bimetallic catalysts is decreased but the strong acidity is slightly increased. It was found that the stability of bimetallic catalysts prepared by co-impregnation and sequential impregnation where the 2nd metal was impregnated before Pt were better than that of monometallic catalyst (undoped Pt one) due to the forming of Pt sites located on the transition metal-oxide modified surface. Among all preparation methods, the sequential impregnation method- having Pt impregnated before the 2nd metal gave the worst stability because this catalyst lacked the modified Pt sites and some fraction of Pt sites was covered by the 2nd metal.

Keywords: alumina, dehydrogenation, platinum, transition metal

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Authors: Perumalsamy Muthiah, Murugesan Thanapalan

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The remains of cheese production contain nutritional value added proteins viz., α-Lactalbumin, β-Lactoglobulin representing 80- 90% of the total volume of milk entering the process. Although several possibilities for cheese-whey exploitation have been assayed, approximately half of world cheese-whey production is not treated but is discarded as effluent. It is necessary to develop an effective and environmentally benign extraction process for the recovery of value added cheese whey proteins. Recently aqueous two phase system (ATPS) have emerged as potential separation process, particularly in the field of biotechnology due to the mild conditions of the process, short processing time, and ease of scale-up. In order to design an ATPS process for the recovery of cheese whey proteins, development of phase diagram and the effect of system parameters such as pH, types and the concentrations of the phase forming components, temperature, etc., on the partitioning of proteins were addressed in order to maximize the recovery of proteins. Some of the practical problems encountered in the application of aqueous two-phase systems for the recovery of Cheese whey proteins were also discussed.

Keywords: aqueous two-phase system, phase diagram, extraction, cheese whey

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Authors: Luguang Qi, Chuang Xie

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In recent years, there has been an increase in the number of reports on cocrystal polymorphism and stoichiomorphism. However, the research on the factors that influence these phenomena is limited. Herein, picolinamide (PAM), nicotinamide (NAM), and isonicotinamide (INA) were selected as co-formers to form multicomponent solids with 4-chloro-3-sulfamoylbenzoic acid (CSBA). Six new cocrystal forms of CSBA were discovered, and their crystal structures were determined. It was found that PAM and NAM can only form one cocrystal with CSBA, while INA can form up to four cocrystals, including both cocrystal polymorphism and stoichiomorphism. Molecular electrostatic potential analysis and crystal structure analysis showed that the functional group position of PAM limited the diversity of cocrystal synthons, while the lattice energy limited the diversity of cocrystal synthons when NAM acted as a co-former. Only INA was not subject to these restrictions when forming cocrystals. Finally, the influence of solvents on cocrystals was illustrated by determining the ternary phase diagrams. The mechanism of two similar solvents, ethyl acetate, and acetone, controlling the crystallization of cocrystal polymorphism was analyzed by molecular simulations.

Keywords: cocrystal polymorphism, cocrystal stoichiomorphism, phase diagram, molecular simulation

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Authors: Csilla Dudás, Éva Böszörményi, Bence Kutus, István Pálinkó, Pál Sipos

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In this study the behavior of alpha-D-isosaccharinate (2-hydroxymethyl-3-deoxy-D-erythro-pentonate, ISA−) in alkaline medium in the presence of calcium was studied. At first the Ca–ISA system was studied by Ca-ion selective electrode (Ca-ISE) in neutral medium at T = 25 °C and I = 1 M NaCl to determine the formation constant of the CaISA+ monocomplex, which was found to be logK = 1.01 ± 0.01 for the reaction of Ca2+ + ISA– = CaISA+. In alkaline medium pH potentiometric titrations were carried out to determine the composition and stability constant of the complex(es) formed. It was found that in these systems above pH = 12.5 the predominant species is the CaISAOH complex. Its formation constant was found to be logK = 3.04 ± 0.05 for the reaction of Ca2+ + ISA– + H2O = CaISAOH + H+ at T = 25 °C and I = 1 M NaCl. Solubility measurements resulted in data consistent with those of the potentiometric titrations. Temperature dependent NMR spectra showed that the slow exchange range between the complex and the free ligand is below 5 °C. It was also showed that ISA– acts as a multidentate ligand forming macrochelate Ca-complexes. The structure of the complexes was determined by using ab initio quantum chemical calculations.

Keywords: Ca-ISE potentiometry, calcium complexes, isosaccharinate ion, NMR spectroscopy, pH potentiometry

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Authors: Ziwei Chen, Yujiang Gao

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The rapid urbanization has caused the massive physical space in Chinese cities to be in a state of duplication and dislocation through the rapid development, forming many daily spaces that cannot be standardized, typed, and identified, such as illegal construction. This phenomenon is known as urban spatial redundancy and is often excluded from mainstream architectural discussions because of its 'remaining' and 'excessive' derogatory label. In recent years, some practice architects have begun to pay attention to this phenomenon and tried to tap the value behind it. In this context, the author takes the redundancy phenomenon of resident space as the research object and explores the inspiration to the urban architectural renewal and the innovative residential area model, based on the urban survey of redundant living space in Hongkou District of Shanghai. On this basis, it shows that the changes accumulated in the long-term use of the building can be re-applied to the goals before the design, which is an important link and significance of the existence of an architecture.

Keywords: rapid urbanization, living space redundancy, architectural renewal, residential area model

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Authors: Hafiz Muhammad Umer Aslam, Mohammad Rafiq Khan

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This techno-economic study reports the feasibility of generating thermoelectric power from municipal solid waste (MSW) of Kasur City by incineration process. The data was gathered from different establishments of Kasur, through appropriate permission from their heads, and processed to design different alternative projects for installation of a thermal power plant in the city of Kasur. A technique of discounted cash flow was used to evaluate alternative projects so that their Benefit to Cost Ratio, Net Present Value, Internal Rate of Return and Payback Period can be determined. The study revealed that Kasur City currently consumes 18MWh electricity and generates 179 tons/day MSW. The generated waste has the ability to produce 2.1MWh electricity at the cost of USD 0.0581/unit with an expenditure of USD 3,907,692 as initial fixed investment of forming about 1/7th of consumption of Kasur. The cost from this source, when compared to current rate of electricity in Pakistan (USD 0.1346), is roughly half.

Keywords: Kasur City, resource recovery, thermoelectric power, waste management

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Authors: Im-Nam Jang, Yong-Sik Ahn

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In this study sintered wick was formed in a heat pipe through the process of sintering a mixture of copper powder with particle sizes of 100μm and 200μm, mixed with a pore-forming agent. The heat pipe's thermal resistance, which affects its heat transfer efficiency, is determined during manufacturing according to powder type, thickness of the sintered wick, and filling rate of the working fluid. Heat transfer efficiency was then tested at various inclination angles (0°, 45°, 90°) to evaluate the performance of heat pipes. Regardless of the filling amount and test angle, the 200μm copper powder type exhibited superior heat transfer efficiency compared to the 100μm type. After analyzing heat transfer performance at various filling rates between 20% and 50%, it was determined that the heat pipe's optimal heat transfer capability occurred at a working fluid filling rate of 30%. The width of the wick was directly related to the heat transfer performance.

Keywords: heat pipe, heat transfer performance, effective pore size, capillary force, sintered wick

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Authors: Pompilia Buzatu, Hazim Qiblawey, Albert Odai, Jana Jamaleddin, Mustafa Nasser, Simon J. Judd

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Membrane bioreactor (MBR) technology is challenged by the tendency for the membrane permeability to decrease due to ‘clogging’. Clogging includes ‘sludging’, the filling of the membrane channels with sludge solids, and ‘ragging’, the aggregation of short filaments to form long rag-like particles. Both sludging and ragging demand manual intervention to clear out the solids, which is time-consuming, labour-intensive and potentially damaging to the membranes. These factors impact on costs more significantly than membrane surface fouling which, unlike clogging, is largely mitigated by the chemical clean. However, practical evaluation of MBR clogging has thus far been limited. This paper presents the results of recent work attempting to quantify sludging and clogging based on simple bench-scale tests. Results from a novel ragging simulation trial indicated that rags can be formed within 24-36 hours from dispersed < 5 mm-long filaments at concentrations of 5-10 mg/L under gently agitated conditions. Rag formation occurred for both a cotton wool standard and samples taken from an operating municipal MBR, with between 15% and 75% of the added fibrous material forming a single rag. The extent of rag formation depended both on the material type or origin – lint from laundering operations forming zero rags – and the filament length. Sludging rates were quantified using a bespoke parallel-channel test cell representing the membrane channels of an immersed flat sheet MBR. Sludge samples were provided from two local MBRs, one treating municipal and the other industrial effluent. Bulk sludge properties measured comprised mixed liquor suspended solids (MLSS) concentration, capillary suction time (CST), particle size, soluble COD (sCOD) and rheology (apparent viscosity μₐ vs shear rate γ). The fouling and sludging propensity of the sludge was determined using the test cell, ‘fouling’ being quantified as the pressure incline rate against flux via the flux step test (for which clogging was absent) and sludging by photographing the channel and processing the image to determine the ratio of the clogged to unclogged regions. A substantial difference in rheological and fouling behaviour was evident between the two sludge sources, the industrial sludge having a higher viscosity but less shear-thinning than the municipal. Fouling, as manifested by the pressure increase Δp/Δt, as a function of flux from classic flux-step experiments (where no clogging was evident), was more rapid for the industrial sludge. Across all samples of both sludge origins the expected trend of increased fouling propensity with increased CST and sCOD was demonstrated, whereas no correlation was observed between clogging rate and these parameters. The relative contribution of fouling and clogging was appraised by adjusting the clogging propensity via increasing the MLSS both with and without a commensurate increase in the COD. Results indicated that whereas for the municipal sludge the fouling propensity was affected by the increased sCOD, there was no associated increased in the sludging propensity (or cake formation). The clogging rate actually decreased on increasing the MLSS. Against this, for the industrial sludge the clogging rate dramatically increased with solids concentration despite a decrease in the soluble COD. From this was surmised that sludging did not relate to fouling.

Keywords: clogging, membrane bioreactors, ragging, sludge

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Authors: Mohammed Jibrin Ndejiko

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Modern and current models such as flow cell technology which enhances a non-destructive growth and inspection of the sessile microbial communities revealed a great understanding of biofilms. A continuous flow system was designed to evaluate possibility of biofilm formation by Escherichia coli DH5α on the stainless steel (type 304) under continuous nutrient supply. The result of the colony forming unit (CFU) count shows that bacterial attachment and subsequent biofilm formation on stainless steel coupons with average surface roughness of 1.5 ± 1.8 µm and 2.0 ± 0.09 µm were both significantly higher (p ≤ 0.05) than those of the stainless steel coupon with lower surface roughness of 0.38 ± 1.5 µm. These observations support the hypothesis that surface profile is one of the factors that influence biofilm formation on stainless steel surfaces. The SEM and FESEM micrographs of the stainless steel coupons also revealed the attached Escherichia coli DH5α biofilm and dehydrated extracellular polymeric substance on the stainless steel surfaces. Thus, the fabricated flow system represented a very useful tool to study biofilm formation under continuous nutrient supply.

Keywords: biofilm, flowcell, stainless steel, coupon

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Authors: Subhamita Chakraborty, Shubhabrata Datta, Sujay Kumar Mukherjea, Partha Protim Chattopadhyay

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Manufacturing of multiphase high strength steel in hot strip mill have drawn significant attention due to the possibility of forming low temperature transformation product of austenite under continuous cooling condition. In such endeavor, reliable prediction of temperature profile of hot strip coil is essential in order to accesses the evolution of microstructure at different location of hot strip coil, on the basis of corresponding Continuous Cooling Transformation (CCT) diagram. Temperature distribution profile of the hot strip coil has been determined by using finite volume method (FVM) vis-à-vis finite difference method (FDM). It has been demonstrated that FVM offer greater computational reliability in estimation of contact pressure distribution and hence the temperature distribution for curved and irregular profiles, owing to the flexibility in selection of grid geometry and discrete point position, Moreover, use of finite volume concept allows enforcing the conservation of mass, momentum and energy, leading to enhanced accuracy of prediction.

Keywords: simulation, modeling, thermal analysis, coil cooling, contact pressure, finite volume method

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Authors: Ayoti Banerjee, Meenakshi Banerjee

Abstract:

The study of metamorphic reaction textures is important in contributing to our understanding of the evolution of metamorphic terranes. Where preserved, they provide information on changes in the P-T conditions during the metamorphic history of the rock, and thus allow us to speculate on the P-T-t evolution of the terrane. Mafic dykes have attracted the attention of petrologists because they act as window to mantle. This rock represents a mafic dyke of doleritic composition. It is fine to medium grained in which clinopyroxene are enclosed by the lath shaped plagioclase grains to form spectacular ophitic texture. At places, sub ophitic texture was also observed. Grains of pyroxene and plagioclase show very less deformation typically plagioclase showing deformed lamella along with plagioclase-clinopyroxene-phyric granoblastic fabric within a groundmass of feldspar microphenocrysts and Fe–Ti oxides. Both normal and reverse zoning were noted in the plagioclase laths. The clinopyroxene grains contain exsolved phases such as orthopyroxene, plagioclase, magnetite, ilmenite along the cleavage traces and the orthopyroxene lamella form granules in the periphery of the clinopyroxene grains. Garnet corona also develops preferentially around plagioclase at the contact of clinopyroxene, ilmenite or magnetite. Tiny quartz and K-fs grains showed symplectic intergrowth with garnet at a few places. The product quartz formed along with garnet rims the coronal garnet and the reacting clinopyroxene. Thin amphibole corona formed along the periphery of deformed plagioclase and clinopyroxene occur as patches over the magmatic minerals. The amphibole coronas cannot be assigned to a late magmatic stage and are interpreted as reactive being restricted to the contact between clinopyroxene and plagioclase, thus postdating the crystallization of both. The amphibole and garnet do not share grain boundary in the entire rock and is thus pointing towards simultaneous crystallization. Olivine is absent. Spectacular myrmekitic growth of orthoclase and quartz rimming the plagioclase is consistent with the potash metasomatic effects that is also found in other rocks of this region. These textural features are consistent with a phase of fluid induced metamorphism (retrogression). But the appearance of coronal garnet and amphibole exclusive of each other reflects the participation if Ti as the prime reason. Presence of Ti as a reactant phase is a must for amphibole forming reactions whereas it is not so in case of garnet forming reactions although the reactants are the same plagioclase and clinopyroxene in both cases. These findings are well validated by petrographical and textural analysis. In order to obtain balanced chemical reactions that explain formation of amphibole and garnet in the mafic dyke rocks a matrix operation technique called Singular Value Decomposition (SVD) was adopted utilizing the measured chemical compositions of the minerals. The computer program C-Space was used for this purpose and the required compositional matrix. Data fed to C-Space was after doing cation-calculation of the oxide percentages obtained from EPMA analysis. The Garnet-Clinopyroxene geothermometer yielded a temperature of 650 degrees Celsius. The Garnet-Clinopyroxene-Plagioclase geobarometer and Al-in amphibole yielded roughly 7.5 kbar pressure.

Keywords: corona, dolerite, geothermometer, metasomatism, metamorphic reaction texture, retrogression

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Authors: Da Eun Sung

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In today’s world, cyber security has become an important international agenda. As the information age has arrived, the need for cyber defense against cyber attacks is mounting, and the significance of cyber cooperation in the international community is drawing attention. Through the course, international society has agreed that the institutionalization of international norms dealing with cyber space and cyber security is crucial ever. Nevertheless, the West, led by the United States of America, and 'the East', composed of Russia and China, have shown conflicting views on forming international norms and principles which would regulate and ward off the possible threats in cyber space. Thus, the international community hasn’t yet to reach an agreement on cyber security. In other words, the difference between both sides on the approach and understanding of principles, objects, and the definition has rendered such. Firstly, this dissertation will cover the Russia’s perception, strategy, and definition on cyber security through analyzing primary source. Then, it will delve into the two contrasting cyber security strategy between Russia and the US by comparing them. And in the conclusion, it will seek the possible solution for the cooperation in the field of cyber security. It is quite worthwhile to look into Russia’s views, which is the main counterpart to the US in this field, especially when the efforts to institutionalize cyber security by the US-led international community have met with their boundaries, and when the legitimacy of them have been challenged.

Keywords: cyber security, cyber security strategic, international relation in cyberspace, Russia

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Authors: Abhishek Ranga

Abstract:

The study examined the effect of accounting choice and level of disclosure on the firm’s implied cost of equity in Indian environment. For the study accounting choice was classified as aggressive or conservative depending upon the firm’s choice of accounting methods, accounting policies and accounting estimates. Level of disclosure is the quantum of financial and non-financial information disclosed in firm’s annual report, essentially in note to accounts section, schedules forming part of financial statements and Management Discussion and Analysis report. Regression models were developed with cost of equity as a dependent variable and accounting choice, level of disclosure as an independent variable along with selected control variables. Cost of equity was measured using Edward-Bell-Ohlson (EBO) valuation model, to measure accounting choice Modified-Jones-Model (MJM) was used and level of disclosure was measured using a disclosure index essentially drawn from Botosan study. Results indicated a negative association between the implied cost of equity and conservative accounting choice and also between level of disclosure and cost of equity.

Keywords: aggressive accounting choice, conservative accounting choice, disclosure, implied cost of equity

Procedia PDF Downloads 437