Search results for: macro and microscopic appearances
518 Immunologically Non-Treated Vascular Xenografts in Long-Term Survival Animals
Authors: W. G. Kim, J. M. Chang, W. S. Kim
Abstract:
Immunologically non-treated and acellularized porcine xenografts were implanted as an arterial graft in goats and comparatively analyzed for the explanted grafts with gross observation, as well as light microscopy and immunohistochemistry, following the predetermined periods. For immunologically non-treated xenografts, bilateral porcine carotid arteries were harvested, and after short-term freezing at -70°C, were implanted into goats. The preparation of acellularized xenograft vessels has been performed with Nacl-SDS solution and stored at the freezer until use. The goats were randomly assigned for three periods of observation (3, 6, and 12 months after implantation), four animals were observed at each of these times. Periodic ultrasonographic examinations were performed during observation period. Following the predetermined periods, the explanted grafts were analyzed. Among 12 animals, one goat died prematurely, and a total of 22 grafts were evaluated. Gross observations revealed non-thrombotic patent smooth lumens. Microscopic examinations of the explanted grafts showed satisfactory cellular reconstruction up to the 12-month observation period. The proportions of CD3 positive T lymphocytes among inflammatory cells infiltrations were very low. In conclusion, these findings, as a whole, suggest that porcine vessel xenografts can be clinically acceptably implanted in the goats as a form of small-diameter vascular graft, regardless of the acellularized xenograft or immunologically non-treated xenograft.Keywords: xenograft, arterial graft, long-term survival animals, immunology
Procedia PDF Downloads 340517 Countercyclical Capital Buffer in the Polish Banking System
Authors: Mateusz Mokrogulski, Piotr Śliwka
Abstract:
The aim of this paper is the identification of periods of excessive credit growth in the Polish banking sector in years 2007-2014 using different methodologies. Due to the lack of precise guidance in CRD IV regarding methods of calculating the credit gap and related deviations from the long-term trends, a few filtering methods are applied, e.g. Hodrick-Prescott and Baxter-King. The solutions based on the switching model are also proposed. The next step represent computations of both the credit gap, and the counter cyclical capital buffer (CCB) rates on a quarterly basis. The calculations are carried out for the entire banking sector in Poland, as well as for its components (commercial and co-operative banks), and different types of loans. The calculations show vividly that in the analysed period there were the times of excessive credit growth. However, the results are different for the above mentioned sub-sectors. Of paramount importance here are mortgage loans, where the outcomes are distorted by high exchange rate fluctuations. The research on the CCB is now going to gain popularity as the buffer will soon become one of the tools of the macro prudential policy under CRD IV. Although the presented method is focused on the Polish banking sector, it can also be applied to other member states. Especially to the Central and Eastern European countries, that are usually characterized by smaller banking sectors compared to EU-15.Keywords: countercyclical capital buffer, CRD IV, filtering methods, mortgage loans
Procedia PDF Downloads 313516 Making New Theoretical Insights into Violence: The Temporal and Spatial Relevance of Blood Spatter Crime Scene Investigations
Authors: Simone Jane Dennis
Abstract:
This paper leverages the spatial and temporal investigative strategy utilized by crime scene investigators – blood spatter work– to engage with the real and metaphorical memorialization of blood-soaked places. It uses this key trope with phenomenological sensibility, to trace the physical and temporal movement of blood outbound from the human body to sites beyond. Working backward, as crime scene investigators do, this paper traces the importance of both space and time and their confluence, to developing a comprehensive theory of violence. To do this work, the paper engages a range of geo-violent scales, from murder scenes to genocides, to both engage an extraordinarily replete literature of bloodshed across history and to move beyond analyses of how significance is assigned to the sites in which blood comes to rest to instead consider the importance of space and time to the structure of violence itself. It is in this regard that the kind of investigative work upon which blood spatter analysis depends is crucial: it engages time and space in reverse to understand the microscopic relations between bodies, places, and numerous (biological, clock, and seasonal) temporalities. Considering the circumstances under which blood escaped a body, the details of its destination in place, and the temporal circumstances of corporal departure, is crucial to making new knowledge about the peculiar temporality and spatiality of violence itself.Keywords: blood, crime scenes, temporality, violence
Procedia PDF Downloads 61515 Assessing Antimicrobial Activity of Various Plant Extracts on Midgutmicroflora of Aedesaegypti
Authors: V. Baweja, K. K. Gupta, V. Dubey, C. Keshavam
Abstract:
Antimicrobial activity of six indigenous plants such as Tulsi Ocimum sanctum, Neem Azadirachta indica, Aloe vera, Turmeric Curcuma longa, Lantana Lantana camara, and Clove Syzygium aromaticum was assessed against the gut microbiota of the dengue fever mosquito Aedes aegypti, keeping in view that the presence of midgut bacteria may affect the ability of the vector to transmit pathogens. Eleven different types of bacterial clones were isolated from the midgut of lab-reared fourth instar larvae of Aedes aegypti and were grown on LB agar medium at an optimum temperature of 25 ºC. Identification of these bacteria was done on the basis of their colony characteristic such as colony size, shape, opacity, elevation, consistency, and growth. Light microscopic studies of the gut microbiota revealed dominance of Gram-negative cocci over gram positive cocci and bacilli and Gram-negative bacilli. Identification of species was done by chemical characterization of the colonies. Crude extracts of all test plants were screened for their antimicrobial activities against gut microbiota by disc diffusion assay. The zone of exclusion seen after 24 hr of incubation in different assays revealed the most potent antibacterial activities in neem followed by clove and turmeric. Lantana and Aloe vera were least effective.Keywords: plant extract, aedes, dengue, antimicrobial activity
Procedia PDF Downloads 397514 Numerical Multi-Scale Modeling of Rubber Friction on Rough Pavements Using Finite Element Method
Authors: Ashkan Nazari, Saied Taheri
Abstract:
Knowledge of tire-pavement interaction plays a crucial role in designing safer and more reliable tires. Characterizing the tire-pavement frictional interaction leads to a better understanding of vehicle performance in braking and acceleration. In this work, we devise a multi-scale simulation approach to incorporate the effect of pavement surface asperities in different length-scales. We construct two- and three-dimensional Finite Element (FE) models to simulate the interaction between a rubber block and a rough pavement surface with asperities in different scales. To achieve this, the road profile is scanned via a laser profilometer and the obtained asperities are implemented in an FE software (ABAQUS) in micro and macro length-scales. The hysteresis friction, which is due to the dissipative nature of rubber, is the main component of the friction force and therefore is the subject of study in this work. Using different scales not only will assist in characterizing the pavement asperities with sufficient details but also, it is highly effective in preventing extreme local deformations and stress gradients which results in divergence in FE simulations. The simulation results will be validated with experimental results as well as the results reported in the literature.Keywords: friction, finite element, multi-scale modeling, rubber
Procedia PDF Downloads 130513 Numerical Homogenization of Nacre
Authors: M. Arunachalam, M. Pandey
Abstract:
Nacre, a biological material that forms the inner-layer of sea shells can achieve high toughness and strength by way of staggered arrangement of strong tablets with soft and weak organic interface. Under applied loads the tablets slide over the adjacent tablets, thus generating inelastic deformation and toughness on macroscopic scale. A two dimensional finite element based homogenization methodology is adopted for obtaining the effective material properties of Nacre using a representative volume element (RVE) at finite deformations. In this work, the material behaviour for tablet and interface are assumed to be Isotropic elastic and Isotropic elastic-perfectly plastic with strain softening respectively. Numerical experiments such as uniaxial tension test along X, Y directions and simple shear test are performed on the RVE with uniform displacement and periodic constraints applied at the RVE boundaries to obtain the anisotropic homogenized response and maximum local stresses within each constituents of Nacre. Homogenized material model is then tested for macroscopic structure under three point bending condition and the results obtained are comparable with the results obtained for detailed microstructure based structure, thus homogenization provides a bridge between macroscopic scale and microscopic scale and homogenized material properties obtained from microstructural (RVE) analysis could be used in large scale structural analysis.Keywords: finite element, homogenization, inelastic deformation, staggered arrangement
Procedia PDF Downloads 313512 A Hybrid Traffic Model for Smoothing Traffic Near Merges
Authors: Shiri Elisheva Decktor, Sharon Hornstein
Abstract:
Highway merges and unmarked junctions are key components in any urban road network, which can act as bottlenecks and create traffic disruption. Inefficient highway merges may trigger traffic instabilities such as stop-and-go waves, pose safety conditions and lead to longer journey times. These phenomena occur spontaneously if the average vehicle density exceeds a certain critical value. This study focuses on modeling the traffic using a microscopic traffic flow model. A hybrid traffic model, which combines human-driven and controlled vehicles is assumed. The controlled vehicles obey different driving policies when approaching the merge, or in the vicinity of other vehicles. We developed a co-simulation model in SUMO (Simulation of Urban Mobility), in which the human-driven cars are modeled using the IDM model, and the controlled cars are modeled using a dedicated controller. The scenario chosen for this study is a closed track with one merge and one exit, which could be later implemented using a scaled infrastructure on our lab setup. This will enable us to benchmark the results of this study obtained in simulation, to comparable results in similar conditions in the lab. The metrics chosen for the comparison of the performance of our algorithm on the overall traffic conditions include the average speed, wait time near the merge, and throughput after the merge, measured under different travel demand conditions (low, medium, and heavy traffic).Keywords: highway merges, traffic modeling, SUMO, driving policy
Procedia PDF Downloads 101511 Macroeconomic Measure of Projectification: An Empirical Study of Pakistani Economy
Authors: Shafaq Rana, Hina Ansar
Abstract:
Projectification is an emerging phenomenon in Western economies. The projects have become the key driver of the economic actions. The impact of projectification is understudy for over a decade. A methodology was developed to measure the degree of projectification at economical level, which was later adapted to measure the degree of projectification in Germany, Norway, and Iceland; and compared the differences in these project societies, considering their industrial structure, organizational size, and the share of project work. Using the same methodology, this study aims to provide empirical evidence of the project work in the context of Pakistan –a developing nation, keeping into consideration the macroeconomic measures, qualitative and quantitative measures of the project i/c GDP, monetary measures, and project success. The research includes a qualitative pre-study to define these macro-measures in the country-specific context and a quantitative study to measure the project work w.r.t hours working in the organizations on projects. The outcome of this study provides the key data on the projectification in a developing economy, which will help industry practitioners and decision-makers to examine the consequences of projectification and strategize, respectively. This study also provides a foundation for further research in individual sectors of the country while exploring different macroeconomic questions, including the effect of projectification on project productivity, income effects, and labor market.Keywords: developing economy, Pakistan, project work, projectification
Procedia PDF Downloads 110510 The Aquatic Plants Community in the Owena-Idanre Section of the Owena River of Ondo State
Authors: Rafiu O. Sanni, Abayomi O. Olajuyigbe, Nelson R. Osungbemiro, Rotimi F. Olaniyan
Abstract:
The Owena River lies within the drainage basins of the Oni, Siluko, and Ogbesse rivers. The river’s immediate surroundings are covered by dense forests, interspersed by plantations of cocoa, oil palm, kolanut, bananas, and other crops. The objectives were to identify the aquatic plants community, comprising the algae and aquatic macrophytes, observe their population dynamics in relation to the two seasons and identify their economic importance, especially to the neighbouring community. The study sites were determined using a stratified sampling method. Three strata were marked out for sampling namely strata I (upstream)–5 stations, strata II (reservoir) –2 stations, and strata III (outflow) 2 stations. These nine stations were tagged st1, st2, st3…st9. The aquatic macrophytes were collected using standard methods and identified at the University of Ibadan herbarium while the algal samples were collected using standard methods for microalgae. The periphytonic species were scraped from surfaces of rocks (perilithic), sucked with large syringe from mud (epipellic), scraped from suspended logs, washed from roots of aquatic angiosperms (epiphytic), as well as shaken from other particles such as suspended plant parts. Some were collected physically by scooping floating thallus of non-microscopic multicellular forms. The specimens were taken to the laboratory and observed under a microscope with mounted digital camera for photomicrography. Identification was done using Prescott.Keywords: aquatic plants, aquatic macrophytes, algae, Owena river
Procedia PDF Downloads 552509 Modeling and Simulation of Pad Surface Topography by Diamond Dressing in Chemical-Mechanical Polishing Process
Authors: A.Chen Chao-Chang, Phong Pham-Quoc
Abstract:
Chemical-mechanical polishing (CMP) process has been widely applied on fabricating integrated circuits (IC) with a soft polishing pad combined with slurry composed of micron or nano-scaled abrasives for generating chemical reaction to remove substrate or film materials from wafer. During CMP process, pad uniformity usually works as a datum surface of wafer planarization and pad asperities can dominate the microscopic pad-slurry-wafer interaction. However, pad topography can be changed by related mechanism factors of CMP and it needs to be re-conditioned or dressed by a diamond dresser of well-distributed diamond grits on a disc surface. It is still very complicated to analyze and understand kinematic of diamond dressing process under the effects of input variables including oscillatory of diamond dresser and rotation speed ratio between the pad and the diamond dresser. This paper has developed a generic geometric model to clarify the kinematic modeling of diamond dressing processes such as dresser/pad motion, pad cutting locus, the relative velocity of the diamond abrasive grits on pad surface, and overlap of cutting for prediction of pad surface topography. Simulation results focus on comparing and analysis kinematics of the diamond dressing on certain CMP tools. Results have shown the significant parameters for diamond dressing process and also discussed. Future study can apply on diamond dresser design and experimental verification of pad dressing process.Keywords: kinematic modeling, diamond dresser, pad cutting locus, CMP
Procedia PDF Downloads 248508 Moderators of the Relationship between Entrepreneurial Self-Efficacy and Expected Firm Growth
Authors: Laszlo Szerb, Zsofia Voros
Abstract:
In this article, we seek to answer why many attempts to empirically link entrepreneurial self-efficacy to growth expectations have failed. While doing so, we reconcile the literature on entrepreneurial self-efficacy and overconfidence. By analyzing GEM APS (Global Entrepreneurship Monitor Adult Population Survey) data, we show that early-stage entrepreneurs’ self-efficacy statements are systematically inflated. Our results also indicate that entrepreneurial overconfidence is fading and its form changes as business owners learn and gather experience. In addition, by using Ajzen’s Theory of Planned Behavior (2006) as a modeling framework, we illustrate that early stage business owners’ overconfidence results in overly high firm growth expectations. However, the changes in the form of overconfidence and the adjustments of expectations on market conditions as a venture ages alter the relationship between overconfidence and growth expectations across the business life-cycle stages. Overall, our study empirically links young entrepreneurs’ overconfidence to their growth expectations at the firm level. This link is important to establish as expected growth was linked to realized growth both on micro and macro levels. Moreover, we detected several moderators of this relationship providing a potential answer to why many studies failed to link entrepreneurial self-efficacy to growth expectations.Keywords: self-efficacy, overconfidence, entrepreneurship, expected growth
Procedia PDF Downloads 265507 Experimental and Numerical Studies on Earthquake Shear Rupture Generation
Authors: Louis N. Y. Wong
Abstract:
En-echelon fractures are commonly found in rocks, which appear as a special set of regularly oriented and spaced fractures. By using both experimental and numerical approaches, this study investigates the interaction among them, and how this interaction finally contributes to the development of a shear rupture (fault), especially in brittle natural rocks. Firstly, uniaxial compression tests are conducted on marble specimens containing en-echelon flaws. The latter is cut by using the water abrasive jet into the rock specimens. The fracturing processes of these specimens leading to the formation of a fault are observed in detail by the use of a high speed camera. The influences of the flaw geometry on the production of tensile cracks and shear cracks, which in turn dictate the coalescence patterns of the entire set of en-echelon flaws are comprehensively studied. Secondly, a numerical study based on a recently developed contact model, flat-joint contact model using the discrete element method (DEM) is carried out to model the present laboratory experiments. The numerical results provide a quantitative assessment of the interaction of en-echelon flaws. Particularly, the evolution of the stress field, as well as the characteristics of new crack initiation, propagation and coalescence associated with the generation of an eventual shear rupture are studied in detail. The numerical results are found to agree well with the experimental results obtained in both microscopic and macroscopic observations.Keywords: discrete element method, en-echelon flaws, fault, marble
Procedia PDF Downloads 252506 PDMS-Free Microfluidic Chips Fabrication and Utilisation for Pulsed Electric Fields Applications
Authors: Arunas Stirke, Neringa Bakute, Gatis Mozolevskis
Abstract:
A technology of microfluidics is an emerging tool in the field of biology, medicine and chemistry. Microfluidic device is also known as ‘lab-on-a-chip’ technology [1]. In moving from macro- to microscale, there is unprecedented control over spatial and temporal gradients and patterns that cannot be captured in conventional Petri dishes and well plates [2]. However, there is not a single standard microfluidic chip designated for all purposes – every different field of studies needs a specific microchip with certain geometries, inlet/outlet, channel depth and other parameters to precisely regulate the required function. Since our group is studying an effect of pulsed electric field (PEF) to the cells, we have manufactured a microfluidic chip designated for high-throughput electroporation of cells. In our microchip, a cell culture chamber is divided into two parallel channels by a membrane, meanwhile electrodes for electroporation are attached to the wall of the channels. Both microchannels have their own inlet and outlet, enabling injection of transfection material separately. Our perspective is to perform electroporation of mammalian cells in two different ways: (1) plasmid and cells are injected in the same microchannel and (2) injected into separate microchannels. Moreover, oxygen and pH sensors are integrated on order to analyse cell viability parameters after PEF treatment.Keywords: microfluidics, chip, fabrication, electroporation
Procedia PDF Downloads 76505 Tokenism and Invisible Labor of Black Women Within Social Work Education
Authors: LaShawnda N. Fields, Valandra
Abstract:
As part of a larger study, this particular line of inquiry focuses on experiences of tokenism and invisible labor expected of Black women within social work education. Black women faculty members and doctoral students participated in semi-formal, in-depth interviews. All participants were identified as members of schools of social work within Carnegie-designated R-1 institutions. Several participants believed that their race independently and the intersection of their race and gender was often misrepresented by their institution as an indication of a diverse and equitable environment. These women believed they were often solicited to participate in visual materials and make public appearances to benefit the school while feeling invisible. Most of the Black women interviewed, whether faculty members or doctoral students, were the sole Black person or one of very few Black women at these schools of social work. Similarly, the Black doctoral students spoke of being “paraded around” as a prized show horse while enduring a toxic culture that lacks inclusion. These women expressed frustration and disappointment as their images and scholarship were featured on websites and within marketing materials, not the pride and joy such exposure should elicit. These experiences of tokenism were taking place while the women constantly received messages of not being good enough or not a good fit at their institution. Invisible labor refers to work that is not compensated nor formally recognized. This labor is primarily committee work and student support. Representation of Black women faculty members is limited at these research-intensive schools of social work resulting in these women being sought out by students across disciplines. Similarly, the Black women doctoral students are informally recruited as peer mentors to support those students rising in the ranks behind them. Though this work is rooted in retention efforts, it is never identified as such. All participants identified committee work related to their identities as another way they find themselves engaged in work that often goes unrecognized and underappreciated. Committee work is usually tied to identity work, such as diversity, equity, and inclusion though it rarely translates to action and improvements. This qualitative study provides insight into the lived experiences of an at-risk and under-represented demographic. Institutions can better understand how they can support this demographic. These Black women scholars have been invited into these institutions but have not historically been granted full access. These women have survived unsavory conditions through sheer determination and support found mostly outside their schools of social work. Utilizing this data as a springboard for informed and action-oriented strategic planning would allow institutions to create inclusive and equity cultures that result in Black women thriving versus simply surviving.Keywords: education, equity, invisible labor, tokenism, intersectionality
Procedia PDF Downloads 85504 Novel Hybrid Ceramic Nanocomposites Fabricated by Rapid Sintering Technology
Authors: Iftikhar Ahmad, Abulhakim Almajid
Abstract:
Alumina (Al2O3) is an attractive structural ceramic however; brittleness turns Al2O3 down for advanced applications. Development of multi-phase phase ceramics systems is promising to curtail the brittleness and the incorporation of strong/elastic graphene, as third phase, into dual phase (Al2O3-SiC) is striking for mechanical upgrading purpose. Thin graphene nanosheets (GNS) were prepared by thermal exfoliation process and reinforced into dual phase ceramic system. The hybrid nanocomposite was consolidated by novel HF-IH (high-frequency induction heating) sintering furnace at 1500 °C under 50 MPa in vacuum conditions. Structural features and grain size of the resulting nanocomposite were analyzed by SEM and TEM whilst the mechanical properties were assessed by microhardness and nanoindentation techniques. The fracture toughness of the hybrid nanocomposites was appraised by direct crack measurement method. Electron microscopic investigations confirmed the preparation of thin (< 10 nm) graphene nanosheets (GNS). HF-IH sintering route condensed the three-phase (GNS-Al2O3-SiC) hybrid nanocomposite system to > 99% relative densities. SEM of the hybrid nanocomposites fractured surfaces revealed even distribution of the nanocomposite constituents and changed in fracture-mode. Structurally, 88% grain reduction into hybrid nanocomposite was also obtained. Mechanically, enhanced fracture toughness (50%) and hardness (53%) were also achieved for hybrid nanocomposites were attained against bench marked monolithic Al2O3.Keywords: alumina, graphene, hybrid nanocomposites, rapid sintering
Procedia PDF Downloads 371503 Maturity Transformation Risk Factors in Islamic Banking: An Implication of Basel III Liquidity Regulations
Authors: Haroon Mahmood, Christopher Gan, Cuong Nguyen
Abstract:
Maturity transformation risk is highlighted as one of the major causes of recent global financial crisis. Basel III has proposed new liquidity regulations for transformation function of banks and hence to monitor this risk. Specifically, net stable funding ratio (NSFR) is introduced to enhance medium- and long-term resilience against liquidity shocks. Islamic banking is widely accepted in many parts of the world and contributes to a significant portion of the financial sector in many countries. Using a dataset of 68 fully fledged Islamic banks from 11 different countries, over a period from 2005 – 2014, this study has attempted to analyze various factors that may significantly affect the maturity transformation risk in these banks. We utilize 2-step system GMM estimation technique on unbalanced panel and find bank capital, credit risk, financing, size and market power are most significant among the bank specific factors. Also, gross domestic product and inflation are the significant macro-economic factors influencing this risk. However, bank profitability, asset efficiency, and income diversity are found insignificant in determining the maturity transformation risk in Islamic banking model.Keywords: Basel III, Islamic banking, maturity transformation risk, net stable funding ratio
Procedia PDF Downloads 408502 Recovery and Εncapsulation of Μarine Derived Antifouling Agents
Authors: Marina Stramarkou, Sofia Papadaki, Maria Kaloupi, Ioannis Batzakas
Abstract:
Biofouling is a complex problem of the aquaculture industry, as it reduces the efficiency of the equipment and causes significant losses of cultured organisms. Nowadays, the current antifouling methods are proved to be labor intensive, have limited lifetime and use toxic substances that result in fish mortality. Several species of marine algae produce a wide variety of biogenic compounds with antibacterial and antifouling properties, which are effective in the prevention and control of biofouling and can be incorporated in antifouling coatings. In the present work, Fucus spiralis, a species of macro algae, and Chlorella vulgaris, a well-known species of microalgae, were used for the isolation and recovery of bioactive compounds, belonging to groups of fatty acids, lipopeptides and amides. The recovery of the compounds was achieved through the application of the ultrasound- assisted extraction, an environmentally friendly method, using green, non-toxic solvents. Moreover, the coating of the antifouling agents was done by innovative encapsulation and coating methods, such as electro-hydrodynamic process. For the encapsulation of the bioactive compounds natural matrices were used, such as polysaccharides and proteins. Water extracts that were incorporated in protein matrices were considered the most efficient antifouling coating.Keywords: algae, electrospinning, fatty acids, ultrasound-assisted extraction
Procedia PDF Downloads 335501 Malachite Ore Treatment with Typical Ammonium Salts and Its Mechanism to Promote the Flotation Performance
Authors: Ayman M. Ibrahim, Jinpeng Cai, Peilun Shen, Dianwen Liu
Abstract:
The difference in promoting sulfurization between different ammonium salts and its anion's effect on the sulfurization of the malachite surface was systematically studied. Therefore, this study takes malachite, a typical copper oxide mineral, as the research object, field emission scanning electron microscopy and energy-dispersive X-ray analysis (FESEM‒EDS), X-ray photoelectron spectroscopy (XPS), and other analytical and testing methods, as well as pure mineral flotation experiments, were carried out to examine the superiority of the ammonium salts as the sulfurizing reagent of malachite at the microscopic level. Additionally, the promoting effects of ammonium sulfate and ammonium phosphate on the malachite sulfurization of xanthate-flotation were compared systematically from the microstructure of sulfurized products, elemental composition, chemical state of characteristic elements, and hydrophobicity surface evolution. The FESEM and AFM results presented that after being pre-treated with ammonium salts, the adhesion of sulfurized products formed on the mineral surface was denser; thus, the flake radial dimension product was significantly greater. For malachite sulfurization flotation, the impact of ammonium phosphate in promoting sulfurization is weaker than ammonium sulfate. The reason may be that hydrolyzing phosphate consumes a substantial quantity of H+ in the solution, which hastens the formation of the copper-sulfur products, decreasing the adhesion stability of copper-sulfur species on the malachite surface.Keywords: sulfurization flotation, adsorption characteristics, malachite, hydrophobicity
Procedia PDF Downloads 61500 A Review on the Challenge and Need of Goat Semen Production and Artificial Insemination in Nepal
Authors: Pankaj K. Jha, Ajeet K. Jha, Pravin Mishra
Abstract:
Goat raising is a popular livestock sub-commodity of mixed farming system in Nepal. Besides food and nutritional security, it has an important role in the economy of many peoples. Goat breeding through AI is commonly practiced worldwide. It is a very basic tool to speed up genetic improvement and increase productivity. For the goat genetic improvement program, the government of Nepal has imported some specialized exotic goat breeds and semen. Some progress has been made in the initiation of selective breeding within the local breeds and practice of AI with imported semen. Importance of AI in goats has drawn more attention among goat farmers. However, importing semen is not a permanent solution at national level; rather, it is more important to develop and establish its own frozen semen production technique. Semen quality and its relationship with fertility are said to be a major concern in animal production, hence accurate measurement of semen fertilizing potential is of great importance. The survivability of sperm cells depends on semen quality. Survivability of sperm cells is assessed through visual and microscopic evaluation of spermatozoal progressive motility and morphology. In Nepal, there is lack of scientific information on seminal attributes of buck semen, its dilution, cooling and freezing technique under management conditions of Nepal. Therefore, the objective of this review was to provide brief information about breeding system, semen production and artificial insemination in Nepalese goat.Keywords: artificial insemination, goat, Nepal, semen
Procedia PDF Downloads 202499 Intercultural Education through Literature Reception: An in-Depth Study of the Cultural and Literary Relations of Romania and China during 1948-2018
Authors: Iulia Elena Gîță
Abstract:
According to the sociological theory of literature, constraints on the creation and share of cultural works can be placed between two extremes: one with a high level of politicization and the other with a high level of commercialization. The overall objective of the present research is to follow the principles of Sociology of Translation to closely map and analyse the publishing activity of Romania concerning China and Chinese literature during four stages of Romanian history between 1948-2018. This paper proposes, thus, an extended approach to literature, to its cultural, political and economic reception. In achieving the proposed objectives, the research expands far beyond the literary text itself, to its macro context, analysing, through quantitative research methods, a statistical database created based on two phases - the first part containing literary and non-fictional works that address and discuss issues related to China; the second part includes literary translations of Chinese literature into Romanian, either by direct translation or by an intermediate language. Throughout this paper we will map not only the number of works, but also the topics approached by writers along the two periods of the political life of Romania.Keywords: bilateral relations, Chinese literature, intercultural understanding, international relations, socio-cultural reception, socio-political constraints, publishing
Procedia PDF Downloads 124498 Somatic Embryogenesis of Lachenalia viridiflora, a Critically Endangered Ornamental Geophyte with High Floricultural Potential
Authors: Vijay Kumar, Mack Moyo, Johannes Van Staden
Abstract:
Lachenalia viridiflora is a critically endangered bulbous plant with high potential on the international floriculture market. In the present study, an efficient protocol for in vitro plantlet regeneration through somatic embryogenesis was developed. Embryogenic callus was established on Murashige and Skoog (MS) basal medium supplemented with various concentrations and combinations of picloram and thidiazuron (TDZ). A high number of SEs (28.5 ± 1.49) with at different developmental stages of somatic embryos (SEs: globular embryos, torpedo and cotyledon embryo with bipolar characteristics) was obtained on Murashige and Skoog (MS) (Murashige and Skoog 1962) medium with 2.5 μM picloram, and 1.0 μM TDZ. Histological and scanning electron microscopic (SEM) analysis confirmed the presence of somatic embryos. Mature somatic embryos germinated and developed into plantlets after 6 weeks on half/full strength MS medium. High plant regeneration frequency (91.11 %) was achieved on full-strength MS medium supplemented with 5 μM phloroglucinol (PG). Well-developed healthy plantlets were successfully acclimatized in the greenhouse with a survival rate of 80%. The result of this study is beneficial in the mass propagation of high-quality Lachenalia viridiflora clonal plants for the commercial horticultural market and also provides a platform for future genetic transformation studies on the plant.Keywords: horticultural plant, Lachenalia viridiflora, phloroglucinol, somatic embryogenesis, thidiazuron
Procedia PDF Downloads 623497 Microstructure and Tribological Properties of AlSi5Cu2/SiC Composite
Authors: Magdalena Suśniak, Joanna Karwan-Baczewska
Abstract:
Microstructure and tribological properties of AlSi5Cu2 matrix composite reinforced with SiC have been studied by microscopic examination and basic tribological properties. Composite material was produced by the mechanical alloying and spark plasma sintering (SPS) technique. The mixture of AlSi5Cu2 chips with 0, 10, 15 wt. % of SiC powder were placed in 250 ml mixing jar and milled 40 hours. To prevent the extreme cold welding the 1 wt. % of stearic acid was added to the powder mixture as a process control agent. Mechanical alloying provide to obtain composites powder with uniform distribution of SiC in matrix. Composite powders were poured into a graphite and a pulsed electric current was passed through powder under vacuum to consolidate material. Processing conditions were: sintering temperature 450°C, uniaxial pressure 32MPa, time of sintering 5 minutes. After SPS process composite samples indicate higher hardness values, lower weight loss, and lower coefficient of friction as compared with the unreinforced alloy. Light microscope micrograph of the worn surfaces and wear debris revealed that in the unreinforced alloy the prominent wear mechanism was the adhesive wear. In the AlSi5Cu2/SiC composites, by increasing of SiC the wear mechanism changed from adhesive and micro-cutting to abrasive and delamination for composite with 20 SiC wt. %. In all the AlSi5Cu2/SiC composites, abrasive wear was the main wear mechanism.Keywords: aluminum matrix composite, mechanical alloying, spark plasma sintering, AlSi5Cu2/SiC composite
Procedia PDF Downloads 380496 Multiscale Model of Blast Explosion Human Injury Biomechanics
Authors: Raj K. Gupta, X. Gary Tan, Andrzej Przekwas
Abstract:
Bomb blasts from Improvised Explosive Devices (IEDs) account for vast majority of terrorist attacks worldwide. Injuries caused by IEDs result from a combination of the primary blast wave, penetrating fragments, and human body accelerations and impacts. This paper presents a multiscale computational model of coupled blast physics, whole human body biodynamics and injury biomechanics of sensitive organs. The disparity of the involved space- and time-scales is used to conduct sequential modeling of an IED explosion event, CFD simulation of blast loads on the human body and FEM modeling of body biodynamics and injury biomechanics. The paper presents simulation results for blast-induced brain injury coupling macro-scale brain biomechanics and micro-scale response of sensitive neuro-axonal structures. Validation results on animal models and physical surrogates are discussed. Results of our model can be used to 'replicate' filed blast loadings in laboratory controlled experiments using animal models and in vitro neuro-cultures.Keywords: blast waves, improvised explosive devices, injury biomechanics, mathematical models, traumatic brain injury
Procedia PDF Downloads 244495 The Effect of Deficit Financing on Macro-Economic Variables in Nigeria (1970-2013)
Authors: Ezeoke Callistus Obiora, Ezeoke Nneka Angela
Abstract:
The study investigated the effect of deficit financing on macroeconomic variables in Nigeria. The specific objectives included to find out the relationship between deficit financing and GDP, interest rate, inflation rate, money supply, exchange rate and private investment respectively on a time series covering a period of 44 years (1970 – 2013). The Ordinary Least Square multiple regression produced statistics for the coefficient of determination (R2), F-test, t-test used for the interpretation of the study. The findings revealed that Deficit financing has significant positive effect on GDP and exchange rate. Again, deficit financing has a positive and insignificant relationship inflation, money supply and investment. Only interest rate recorded negative yet insignificant relationship with deficit financing. The implications of the findings are that deficit financing can be a veritable tool for boosting economic development in Nigeria, but the influential positively rising exchange rate implies that deficit financing devalues the Naira exchange rate to other currencies indicating that deficit financing can affect Nigerians competitive advantage at the world market. Thus, the study concludes that deficit financing has not encouraged economic growth in Nigeria.Keywords: deficit financing, money supply, exchange rate, inflation, GDP, investment, Nigeria
Procedia PDF Downloads 470494 Simulation Studies of High-Intensity, Nanosecond Pulsed Electric Fields Induced Dynamic Membrane Electroporation
Authors: Jiahui Song
Abstract:
The application of an electric field can cause poration at cell membranes. This includes the outer plasma membrane, as well as the membranes of intracellular organelles. In order to analyze and predict such electroporation effects, it becomes necessary to first evaluate the electric fields and the transmembrane voltages. This information can then be used to assess changes in the pore formation energy that finally yields the pore distributions and their radii based on the Smolchowski equation. The dynamic pore model can be achieved by including a dynamic aspect and a dependence on the pore population density into the pore formation energy equation. These changes make the pore formation energy E(r) self-adjusting in response to pore formation without causing uncontrolled growth and expansion. By using dynamic membrane tension, membrane electroporation in response to a 180kV/cm trapezoidal pulse with a 10 ns on time and 1.5 ns rise- and fall-times is discussed. Poration is predicted to occur at times beyond the peak at around 9.2 ns. Modeling also yields time-dependent distributions of the membrane pore population after multiple pulses. It shows that the pore distribution shifts to larger values of the radius with multiple pulsing. Molecular dynamics (MD) simulations are also carried out for a fixed field of 0.5 V/nm to demonstrate nanopore formation from a microscopic point of view. The result shows that the pore is predicted to be about 0.9 nm in diameter and somewhat narrower at the central point.Keywords: high-intensity, nanosecond, dynamics, electroporation
Procedia PDF Downloads 147493 Bioconcentration Analysis of Iodine Species in Seaweed (Eucheuma cottonii) from Maluku Marine as Alternative Food Source
Authors: Yeanchon H. Dulanlebit, Nikmans Hattu, Gloria Bora
Abstract:
Seaweed is a type of macro algae which are good source of iodine and have been widely used as food and nutrition supplement. One of iodine species that found in ocean plant is iodate. Analysis of iodate in seaweed (Eucheuma cottonii) from coastal area of Maluku has been done. The determination is done by using spectrophotometric method. Iodate in sample is reduced in excess of potassium iodide in the presence of acid solution, and then is reacted with starch to form blue complex. The study found out that the highest wavelength on determination of iodate species using spectrophotometer analysis method is 570 nm. Optimum value to yield maximum absorption is used in this research. Contents of iodate in seawater from coastal area of Ambon Island, Western Seram and Southeast Maluku are 0.2655, 0.2719 and 0.1760 mg/L, respectively. While in seaweeds from Ambon Island, Western Seram, Southeast Maluku-Taar, Ohoidertawun and Wab are 6.3122, 6.3293, 6.2333, 3.7406 and 4.4207 mg/kg in dry weight. Bioconcentration (enrichment) factor of iodate in seaweed (Eucheuma cottonii) from the three samples (cluster) is different; in Coastal area of Ambon Island, Western Seram and Southeast Maluku respectively are 23.78, 23.28 and 27.26.Keywords: bioconcentration, eucheuma cottonii, iodate, iodine, seaweed
Procedia PDF Downloads 214492 Statistical Mechanical Approach in Modeling of Hybrid Solar Cells for Photovoltaic Applications
Authors: A. E. Kobryn
Abstract:
We present both descriptive and predictive modeling of structural properties of blends of PCBM or organic-inorganic hybrid perovskites of the type CH3NH3PbX3 (X=Cl, Br, I) with P3HT, P3BT or squaraine SQ2 dye sensitizer, including adsorption on TiO2 clusters having rutile (110) surface. In our study, we use a methodology that allows computing the microscopic structure of blends on the nanometer scale and getting insight on miscibility of its components at various thermodynamic conditions. The methodology is based on the integral equation theory of molecular liquids in the reference interaction site representation/model (RISM) and uses the universal force field. Input parameters for RISM, such as optimized molecular geometries and charge distribution of interaction sites, are derived with the use of the density functional theory methods. To compare the diffusivity of the PCBM in binary blends with P3HT and P3BT, respectively, the study is complemented with MD simulation. A very good agreement with experiment and the reports of alternative modeling or simulation is observed for PCBM in P3HT system. The performance of P3BT with perovskites, however, seems as expected. The calculated nanoscale morphologies of blends of P3HT, P3BT or SQ2 with perovskites, including adsorption on TiO2, are all new and serve as an instrument in rational design of organic/hybrid photovoltaics. They are used in collaboration with experts who actually make prototypes or devices for practical applications.Keywords: multiscale theory and modeling, nanoscale morphology, organic-inorganic halide perovskites, three dimensional distribution
Procedia PDF Downloads 145491 An Association between Stock Index and Macro Economic Variables in Bangladesh
Authors: Shamil Mardi Al Islam, Zaima Ahmed
Abstract:
The aim of this article is to explore whether certain macroeconomic variables such as industrial index, inflation, broad money, exchange rate and deposit rate as a proxy for interest rate are interlinked with Dhaka stock price index (DSEX index) precisely after the introduction of new index by Dhaka Stock Exchange (DSE) since January 2013. Bangladesh stock market has experienced rapid growth since its inception. It might not be a very well-developed capital market as compared to its neighboring counterparts but has been a strong avenue for investment and resource mobilization. The data set considered consists of monthly observations, for a period of four years from January 2013 to June 2018. Findings from cointegration analysis suggest that DSEX and macroeconomic variables have a significant long-run relationship. VAR decomposition based on VAR estimated indicates that money supply explains a significant portion of variation of stock index whereas, inflation is found to have the least impact. Impact of industrial index is found to have a low impact compared to the exchange rate and deposit rate. Policies should there aim to increase industrial production in order to enhance stock market performance. Further reasonable money supply should be ensured by authorities to stimulate stock market performance.Keywords: deposit rate, DSEX, industrial index, VAR
Procedia PDF Downloads 156490 Changes in Attitudes of State Towards Orthodox Church: Greek Case after Eurozone Crisis in Alexis Tsipras Era
Authors: Zeynep Selin Balci, Altug Gunal
Abstract:
Religion has always an effect on the policies of states. In the case of religion having a central role in defining identity, especially when becoming an independent state, the bond between religious authority and state cannot easily be broken. As independence of Greece from the Ottoman Empire was acquired at the same time with the creation of its own church under the name of the Church of Greece by declaring its independence from the Greek Orthodox Patriarchate in Istanbul, the new church became an important part of Greek national identity. As the Church has the ability to influence Greeks, its rituals, public appearances, and practices are used to provide support to the state. Although there sometimes have been controversies between church and state, it has always been a fact that church is an integral part of the state, which is proved by that paying the salaries of priest by state payroll and them being naturally civil servants. European Union membership, on the other hand, has a changing impact on this relationship. This impact started to be more visible in 2000 when then government decided to exclude the religion section from identity cards. Church’s reaction was to gather people around recalling their religious identity and followed by redefining the content of nationality, which aspired nationalist fronts. After 2015 when leftist coalition Syriza and its self-described atheist leader came to power, the situation for nationalists and Church became more tangling in addition to the economic crisis started in 2010 and evolved into the Eurozone crisis by affecting not only Greece but also other members. Although the church did not have direct confrontations with the government, the fact that Tsipras refused to take the oath on Bible created tensions because it was not acceptable for a state whose Constitution starts ‘in the name of the Holy, Consubstantial and Indivisible Trinity’. Moreover, austerity measures to overcome the economic crisis, which affected the everyday life of citizens in terms of both prices and salaries, did not harm the church’s economic situation much. Considering church being the second biggest landowner after state and paying no taxes, the fact that church was exempt from austerity measures showed to the government the necessity to find a way to make church contribute to solution for the crisis. In 2018, when the government agreed with the head of the church on cutting off the priests from government payroll automatically meaning to end priests’ civil servant status, it created tensions both for church and in society. As a result of the elections held in July 2019, Tsipras could not have the chance to apply the decision as he left the office. In light of these, this study aims to analyze the position of the church in the economic crisis and its effects on Tsipras term. In order to sufficiently understand this, it is to look at the historical changing points of Church’s influence in Greek’s eyes.Keywords: Eurozone crisis, Greece, Orthodox Church, Tsipras
Procedia PDF Downloads 119489 Influence of the 3D Printing Parameters on the Dynamic Characteristics of Composite Structures
Authors: Ali Raza, Rūta Rimašauskienė
Abstract:
In the current work, the fused deposition modelling (FDM) technique is used to manufacture PLA reinforced with carbon fibre composite structures with two unique layer patterns, 0°\0° and 0°\90°. The purpose of the study is to investigate the dynamic characteristics of each fabricated composite structure. The Macro Fiber Composite (MFC) is embedded with 0°/0° and 0°/90° structures to investigate the effect of an MFC (M8507-P2 type) patch on vibration amplitude suppression under dynamic loading circumstances. First, modal analysis testing was performed using a Polytec 3D laser vibrometer to identify bending mode shapes, natural frequencies, and vibration amplitudes at the corresponding natural frequencies. To determine the stiffness of each structure, several loads were applied at the free end of the structure, and the deformation was recorded using a laser displacement sensor. The findings confirm that a structure with 0°\0° layers pattern was found to have more stiffness compared to a 0°\90° structure. The maximum amplitude suppression in each structure was measured using a laser displacement sensor at the first resonant frequency when the control voltage signal with optimal phase was applied to the MFC. The results confirm that the 0°/0° pattern's structure exhibits a higher displacement reduction than the 0°/90° pattern. Moreover, stiffer structures have been found to perform amplitude suppression more effectively.Keywords: carbon fibre composite, MFC, modal analysis stiffness, stiffness
Procedia PDF Downloads 58