Search results for: turbojet performances

Authors: Shirin Zubair

Abstract:

Keeping in view the segregation of space(s) experienced by young women and men at puberty in Pakistan and the socially constructed and performative aspect of gender identity by Western theorists of gender and self, this paper will explore Pakistani youth’s differential, gendered performances. Specifically focused on Pakistani youth’s perceptions and experiences of sexuality, extramarital and same-sex relationships in constructing and performing gendered identities as manifested through their talk, the research will also draw upon recent theories of space in cultural studies and postcolonial discourses. The data cited has been culled from two different studies conducted at universities in the city of Multan. Informal, unstructured group discussions of women and men aged between twenty and twenty nine years of age were recorded separately among groups of friends and cohorts studying at two different universities. The findings clearly show both young women and men doing the boundary work in identity construction in private and public spaces: talking of sexuality, sexual desire and sexual relationships, women tend to safely couch their articulations in euphemisms: distance themselves from the Western concepts of sexual liberation ; while young men’s exhibitionism in boasting of their sexual prowess and sexual encounters as well as the use of sexually explicit and tabooed words frequently in their intimate conversations shows a clear departure from and a contestation of the normative public discourses. Further the findings illustrate that young men conform to the patriarchal ideologies by constructing heterosexual identities whereas young women initiate discourse on same-sex relationships. The data also reveals that the private identities of these young Pakistanis are different from their public identities, as it is in their intimate conversations and private (or safe) spaces that they talk about their pre-marital sexual activities and love affairs. These intimate and safe spaces thus emerge as subversion and contestation of their public identity, as sex and sexuality are tabooed subjects in public discourses.

Keywords: sexuality, gender, identity, performance

Procedia PDF Downloads 310

Authors: O. Elkana, O Heyman, S. Hamdan, M. Franko, J. Vatine

Abstract:

Objective: To investigate whether a direct link exists between perceived pain (PP) and executive functions (EF), above and beyond the influence of depression symptoms, in the context of medical rehabilitation. Design: Cross-sectional study. Setting: Rehabilitation Hospital. Participants: 125 medical records of hospitalized patients were screened for matching to our inclusion criteria. Only 60 patients were found fit and were asked to participate. 19 decline to participate on personal basis. The 41 neurologically intact patients (mean age 46, SD 14.96) that participated in this study were in their sub-acute stage of recovery, with fluent Hebrew, with intact upper limb (to neutralize influence on psychomotor performances) and without an organic brain damage. Main Outcome Measures: EF were assessed using the Wisconsin Card Sorting Test (WCST) and the Stop-Signal Test (SST). PP was measured using 3 well-known pain questionnaires: Pain Disability Index (PDI), The Short-Form McGill Questionnaire (SF-MPQ) and the Pain Catastrophizing Scale (PCS). Perceived pain index (PPI) was calculated by the mean score composite from the 3 pain questionnaires. Depression symptoms were assessed using the Patient Health Questionnaire (PHQ-9). Results: The results indicate that irrespective of the presence of depression symptoms, PP is directly correlated with response inhibition (SST partial correlation: r=0.5; p=0.001) and mental flexibility (WSCT partial correlation: r=-0.37; p=0.021), suggesting decreased performance in EF as PP severity increases. High correlations were found between the 3 pain measurements: SF-MPQ with PDI (r=0.62, p<0.001), SF-MPQ with PCS (r=0.58, p<0.001) and PDI with PCS (r=0.38, p=0.016) and each questionnaire alone was also significantly associated with EF; thus, no specific questionnaires ‘pulled’ the results obtained by the general index (PPI). Conclusion: Examining the direct association between PP and EF, beyond the contribution of depression symptoms, provides further clinical evidence suggesting that EF and PP share underlying mediating neuronal mechanisms. Clinically, the importance of assessing patients' EF abilities as well as PP severity during rehabilitation is underscored.

Keywords: depression, executive functions, mental-flexibility, neuropsychology, pain perception, perceived pain, response inhibition

Procedia PDF Downloads 222

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

Abstract:

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

Keywords: gold, layer, polymer, macromolecular

Procedia PDF Downloads 370

Authors: B. Dehghan, T. Toppi, M. Aprile, M. Motta

Abstract:

The environmental concerns related to global warming and ozone layer depletion along with the growing worldwide demand for heating and cooling have brought an increasing attention toward ecological and efficient Heating, Ventilation, and Air Conditioning (HVAC) systems. Furthermore, since space heating accounts for a considerable part of the European primary/final energy use, it has been identified as one of the sectors with the most challenging targets in energy use reduction. Heat pumps are commonly considered as a technology able to contribute to the achievement of the targets. Current research focuses on the full load operation and seasonal performance assessment of three gas-driven absorption heat pump cycles. To do this, investigations of the gas-driven air-source ammonia-water absorption heat pump systems for small-scale space heating applications are presented. For each of the presented cycles, both full-load under various temperature conditions and seasonal performances are predicted by means of numerical simulations. It has been considered that small capacity appliances are usually equipped with fixed geometry restrictors, meaning that the solution mass flow rate is driven by the pressure difference across the associated restrictor valve. Results show that gas utilization efficiency (GUE) of the cycles varies between 1.2 and 1.7 for both full and partial loads and vapor exchange (VX) cycle is found to achieve the highest efficiency. It is noticed that, for typical space heating applications, heat pumps operate over a wide range of capacities and thermal lifts. Thus, partially, the novelty introduced in the paper is the investigation based on a seasonal performance approach, following the method prescribed in a recent European standard (EN 12309). The overall result is a modest variation in the seasonal performance for analyzed cycles, from 1.427 (single-effect) to 1.493 (vapor-exchange).

Keywords: absorption cycles, gas utilization efficiency, heat pump, seasonal performance, vapor exchange cycle

Procedia PDF Downloads 89

Authors: Daly M. J, Condron C, Mulhall C, Eppich W, O'Neill J.

Abstract:

Introduction: In contemporary clinical cardiology, comprehensive and holistic bedside evaluation including accurate cardiac auscultation is in decline despite having positive effects on patients and their outcomes. Methods: Scripted histories and scoring checklists for three clinical scenarios in cardiology were co-created and refined through iterative consensus by a panel of clinical experts; these were then paired with recordings of auscultatory findings from three actual patients with known valvular heart disease. A wearable vest with embedded pressure-sensitive panel speakers was developed to transmit these recordings when examined at the standard auscultation points. RCSI medical students volunteered for a series of three formative long case examinations in cardiology (LC1 – LC3) using this hybrid simulation. Participants were randomised into two groups: Group 1 received individual teaching from an expert trainer between LC1 and LC2; Group 2 received the same intervention between LC2 and LC3. Each participant’s long case examination performance was recorded and blindly scored by two peer participants and two RCSI examiners. Results: Sixty-eight participants were included in the study (age 27.6 ± 0.1 years; 74% female) and randomised into two groups; there were no significant differences in baseline characteristics between groups. Overall, the median total faculty examiner score was 39.8% (35.8 – 44.6%) in LC1 and increased to 63.3% (56.9 – 66.4%) in LC3, with those in Group 1 showing a greater improvement in LC2 total score than that observed in Group 2 (p < .001). Using the novel checklist, intraclass correlation coefficients (ICC) were excellent between examiners in all cases: ICC .994 – .997 (p < .001); correlation between peers and examiners improved in LC2 following peer grading of LC1 performances: ICC .857 – .867 (p < .001). Conclusion: Hybrid simulation and quantitative grading improve learning, standardisation of assessment, and direct comparisons of both performance and acumen in clinical cardiology.

Keywords: cardiology, clinical skills, long case examination, hybrid simulation, checklist

Procedia PDF Downloads 87

Authors: Oyuna Weina

Abstract:

This study examines how musicians use visual and zoological metaphors for singing technique and voice quality in a genre of traditional music called urtiin duu (‘long song’) in Alshaa, Inner Mongolia, China. Previous studies have discussed melodic contour in Mongol music, but little study of the intersection of singing technique, visual and zoological metaphors has yet been undertaken. The purpose of this study is to address this lack by analysing urtiin duu itself, traditional pedagogy and performances, all of which have been inspired and are assessed by reference to nature and mobile pastoral herding practices. This study investigates the visual and zoological metaphors related to urtiin duu especially colour, the shape of the circle and animals in the Mongol community. Urtiin duu singing is associated with certain colours in song texts, in selection of repertoire and in the status of singers. Musicians also use colour to describe timbre. These colours in turn reference worship of nature, religions, and daily practices of most Mongols in Alshaa. Moreover, voice quality and singing technique are often related to the animals not only in song text but also in the approach to breathing and to melodic contour. Additionally, the concept of boronhoi (‘the shape of circle’), not only is applied to the melodic contour but also to the voice quality and singing technique. These three factors illustrate the connections among nature, spiritual world and everyday herding life of Mongols. These different connections provide evidence of multi-layered meanings. In contemporary Alshaa, urtiin duu singers received Western musical training from the city and returned to their homelands to perform urtiin duu. In doing so, they are also trying to reconnect with the history, nature and spiritual world in order to achieve their ideal sound. Within a multicultural society, singers negotiate amongst themselves, and with ethnic groups, audiences and government officials. The power of the metaphor therefore assists and reconnects the strength of regional identity and ethnic identity in Alshaa.

Keywords: Alshaa, urtiin duu, visual, zoological metaphors

Procedia PDF Downloads 335

Authors: Prashant Das, Tushar Singh, Virendra Byadwal

Abstract:

The present study attempted to understand the role of cognitive flexibility and employee engagement in predicting employees’ turnover intentions. Employee turnover is a significant problem that many organizations are facing these days. Employee turnover is not only extremely expensive for the employer but also results in poor production levels. In developing countries like India, organizations once believed to have most stable employees, are facing major turnover problems. One such organization is banking organizations. Due to globalization, banks are now changing their work scenarios under which the employees have many different roles to perform. Cognitive flexibility which refers to an individual’s ability to shift cognitive sets and to adapt to one’s changing environment, thus seems to be an important factor that are responsible for the employee turnover in organizations. It is hypothesized that those with higher cognitive flexibility would be more able to adapt to the changing work demands of the organizations and thus would show less turnover intentions. Another factor that seems to be important in predicting turnover is employee engagement. Kahn referred to engagement in terms of the harnessing of organization members’ selves to their work roles [by which they] employ and express themselves physically, cognitively, and emotionally during role performances. Studies have shown a strong relationship between employee engagement and turnover intentions. Those with higher engagement with their jobs have found to show low turnover intentions. This study thus hypothesizes that employees with higher engagement will show lower levels of turnover intentions. A total of 150 bank employees (75 from private and 75 from public) participated in this study. They were administered Cognitive Flexibility Scale, Gallup Questionnaire and Intention to Stay Questionnaire along with another questionnaire asking for their demographic details. Results of the study revealed that employees with higher levels of cognitive flexibility and employee engagement show lover levels of turnover intentions. However, the effect is more prominent in case of employees of private banks. Demographic characteristics such as level of the employee and years of engagement in the current job have also been found to be influencing the relationship between cognitive flexibility, employee engagement and turnover intentions. Results of the study are interpreted in accordance to the prevalent literature and theoretical positions.

Keywords: cognitive flexibility, employee engagement, organization, turnover intentions

Procedia PDF Downloads 403

Authors: Ntachobazi bosco

Abstract:

Tourism Development and Planning in Rwanda: Rwanda, a small landlocked country located in the heart of Africa, has experienced significant growth in its tourism industry in recent years. The country’s stunning natural beauty, rich cultural heritage, and warm hospitality have made it an attractive destination for travelers from around the world. However, to ensure sustainable tourism development and planning, the Rwandan government has implemented various strategies and policies to promote responsible tourism practices. Infrastructure Development: To support the growth of the tourism industry, the Rwandan government has invested heavily in infrastructure development. This includes the construction of new hotels, resorts, and lodges, as well as the upgrading of existing facilities. The government has also improved the country’s transportation network, including the construction of new airports and the upgrading of existing ones. Conservation Efforts: Rwanda is home to several national parks and reserves, including the famous Volcanoes National Park, which is known for its mountain gorilla populations. To protect these natural wonders, the Rwandan government has implemented conservation efforts, such as the establishment of protected areas and the development of sustainable tourism practices. Community-Based Tourism: Community-based tourism is a key component of Rwanda’s tourism development strategy. The government has established several community-based tourism programs, which aim to involve local communities in the tourism industry and provide them with economic benefits. These programs include homestays, village tours, and cultural performances. Sustainable Tourism Practices: To promote sustainable tourism practices, the Rwandan government has implemented several initiatives, such as the use of eco-friendly accommodations and the promotion of responsible wildlife viewing practices. The government has also established the Rwanda Tourism Board, which is responsible for promoting and regulating the tourism industry. Challenges and Opportunities: Despite the growth of the tourism industry in Rwanda, several challenges need to be addressed, such as the lack of skilled labor and the need for more infrastructure development. However, there are also several opportunities for the industry, such as the potential for ecotourism and the growth of the meetings, incentives, conventions, and exhibitions (MICE) market.

Keywords: tourism, in rwanda, developent, in africa

Procedia PDF Downloads 41

Authors: S. K. Ghosh, C. Srivastava, P. K. Limaye, V. Kain

Abstract:

Electroplated hard chromium is widely known in coatings and surface finishing, automobile and aerospace industries because of its excellent hardness, wear resistance and corrosion properties. However, its precursor, Cr+6 is highly carcinogenic in nature and a consensus has been adopted internationally to eradicate this coating technology with an alternative one. The search for alternate coatings to electroplated hard chrome is continuing worldwide. Various alloys and nanocomposites like Co-W alloys, Ni-Graphene, Ni-diamond nanocomposites etc. have already shown promising results in this regard. Basically, in this study, electroless Ni-P alloys with excellent corrosion resistance was taken as the base matrix and incorporation of tungsten as third alloying element was considered to improve the hardness and wear resistance of the resultant alloy coating. The present work is focused on the preparation of Ni–W–P coatings by electrodeposition with different content of phosphorous and its effect on the electrochemical, mechanical and tribological performances. The results were also compared with Ni-W alloys. Composition analysis by EDS showed deposition of Ni-32.85 wt% W-3.84 wt% P (designated as Ni-W-LP) and Ni-18.55 wt% W-8.73 wt% P (designated as Ni-W-HP) alloy coatings from electrolytes containing of 0.006 and 0.01M sodium hypophosphite respectively. Inhibition of tungsten deposition in the presence of phosphorous was noted. SEM investigation showed cauliflower like growth along with few microcracks. The as-deposited Ni-W-P alloy coating was amorphous in nature as confirmed by XRD investigation and step-wise crystallization was noticed upon annealing at higher temperatures. For all the coatings, the nanohardness was found to increase after heat-treatment and typical nanonahardness values obtained for 400°C annealed samples were 18.65±0.20 GPa, 20.03±0.25 GPa, and 19.17±0.25 for alloy coatings Ni-W, Ni-W-LP and Ni-W-HP respectively. Therefore, the nanohardness data show very promising results. Wear and coefficient of friction data were recorded by applying a different normal load in reciprocating motion using a ball on plate geometry. Post experiment, the wear mechanism was established by detail investigation of wear-scar morphology. Potentiodynamic measurements showed coating with a high content of phosphorous was most corrosion resistant in 3.5wt% NaCl solution.

Keywords: corrosion, electrodeposition, nanohardness, Ni-W-P alloy coating

Procedia PDF Downloads 328

Authors: Sadeq Al Yaari, Nassr Almaflehi, Ayman Al Yaari, Adham Al Yaari, Montaha Al Yaari, Aayah Al Yaari, Sajedah Al Yaari

Abstract:

Background: Assessment of language-related functional activities (ALFA) is of vital importance in assessing aphasics’ performance of both sexes. However, the validity and reliability of this language therapeutic test has never been validated in the Arabic medical literature. Purpose: The aim of this study was to validate the test by assessing the language-related functional activities of 100 gender aphasics based in a medical faculty. Design: ALFA Pre-and-posttest was administered twice in three weeks to test the language-related functional activities of 100 gender aphasics. Settings: Al Khars hospital in Al Ahsa’a, Kingdom of Saudi Arabia (KSA). Participants: Sixteen to eight-year-old participants (N = 100 men and women) were enrolled in this experiment. Again, the purpose was to assess their language-related functional activities using ALFA. Procedures: The first step was to translate the English version of ALFA test into the mother tongue of the patients (Arabic). Secondly, the translated text is reviewed and edited by three specialists of Arabic language. Having the test standardized, the third step was to assess language-related functional activities of the participants in natural environment. Assessment took place in three weeks. In the first week, a pre-test was administered to the participants at hand and after two weeks, a post-test was administered to identify whether or not significant differences between the two tests (pre-and-posttest) could be observed. Interventions: Outcomes of the results obtained from the analyses were broadly discussed. Linguistic and statistical comparisons were held to illustrate the findings of this study. Main outcomes and Results: The analysis of the obtained results indicated that the performance of the aphasic participants in the post-test did not differ from that of the pre-test (, respectively). Conclusions & Implications: ALFA was proved to be a valid and reliable test. Moreover, outlined results pointed out the importance of assessing not only gender aphasics’ language, but also their language-related functional activities. Further research is needed to explore how gender aphasics’ verbal and non-verbal performances interact.

Keywords: ALFA, language test, Arab aphasics, validity, reliability, psychoneurolinguistics.

Procedia PDF Downloads 14

Authors: Orit Wolf

Abstract:

Classical music confronts a crucial challenge: updating cherished concert traditions for the digital age. This paper is a journey, and a quest to make classical concerts resonate with a new generation. It's not just about asking questions; it's about exploring the future of classical concerts and their potential to captivate and connect with today's audience in an era defined by change. The younger generation, known for their love of diversity, interactive experiences, and multi-sensory immersion, cannot be overlooked. This paper explores innovative strategies that forge deep connections with audiences whose relationship with classical music differs from the past. The urgency of this challenge drives the transformation of classical concerts. Examining classical concerts is necessary to understand how they can harmonize with contemporary sensibilities. New dimensions in audiovisual experiences that enchant the emerging generation are sought. Classical music must embrace the technological era while staying open to fusion and cross-cultural collaboration possibilities. The role of technology and Artificial Intelligence (AI) in reshaping classical concerts is under research. The fusion of classical music with digital experiences and dynamic interdisciplinary collaborations breathes new life into the concert experience. It aligns classical music with the expectations of modern audiences, making it more relevant and engaging. Exploration extends to the structure of classical concerts. Conventions are challenged, and ways to make classical concerts more accessible and captivating are sought. Inspired by innovative artistic collaborations, musical genres and styles are redefined, transforming the relationship between performers and the audience. This paper, therefore, aims to be a catalyst for dialogue and a beacon of innovation. A set of critical inquiries integral to reshaping classical concerts for the digital age is presented. As the world embraces digital transformation, classical music seeks resonance with contemporary audiences, redefining the concert experience while remaining true to its roots and embracing revolutions in the digital age.

Keywords: new concert formats, reception of classical music, interdiscplinary concerts, innovation in the new musical era, mash-up, cross culture, innovative concerts, engaging musical performances

Procedia PDF Downloads 31

Authors: Sara Khamseh, Kambiz Javanruee, Hamid Khorsand

Abstract:

Plenty of metallic materials are used for biomedical applications like hip joints and screws. Besides, it is reported that metal platforms such as stainless steel show significant deterioration because of wear and friction. The surface of metal substrates has been coated with a variety of multicomponent coatings to prevail these problems. The carbon-based multicomponent coatings such as metal-added amorphous carbon and diamond coatings are crucially important because of their remarkable tribological performance and chemical stability. In the current study, H-D contained Nb: (a-C) multicomponent coatings (H-D: hexagonal diamond, a-C: amorphous carbon) coated on A 304 steel substrates using an unbalanced magnetron (UBM) sputtering system. The effects of Nb and H-D content and ID/IG ratio on microstructure, mechanical and tribological characteristics of (Nb: H-D: a-C) composite coatings were investigated. The results of Raman spectroscopy represented that a-C phase with a Graphite-like structure (GLC with high value of sp2 carbon bonding) is formed, and its domain size increased with increasing Nb content of the coatings. Moreover, the Nb played a catalyst for the formation of the H-D phase. The nanoindentation hardness value of the coatings ranged between ~17 to ~35 GPa and (Nb: H-D: a-C) composite coatings with more H-D content represented higher hardness and plasticity index. It seems that the existence of extra-hard H-D particles straightly increased hardness. The tribological performance of the coatings was evaluated using the pin-on-disc method under the wet environment of SBF (Simulated Body Fluid). The COF value of the (Nb: H-D: a-C) coatings decreased with an increasing ID/IG ratio. The lower coefficient of friction is a result of the lamelliform array of graphitic domains. Also, the wear rate of the coatings decreased with increasing H-D content of the coatings. Based on the literature, a-C coatings with high hardness and H3/E2 ratio represent lower wear rates and better tribological performance. According to the nanoindentation analysis, hardness and H3/E2 ratio of (Nb: H-D: a-C) multicomponent coatings increased with increasing H-D content, which in turn decreased the wear rate of the coatings. The mechanical and tribological potency of (Nb: H-D: a-C) composite coatings on A 304 steel substrates paved the way for the development of innovative advanced coatings to ameliorate the performance of A 304 steel for biomedical applications.

Keywords: COF, mechanical properties, (Nb: H-D: a-C) coatings, wear rate

Procedia PDF Downloads 74

Authors: Bing Lu, Shuang Li, Hongyuan Zhou

Abstract:

The steel–concrete hybrid structure has been extensively employed in high–rise buildings and super high–rise buildings. The light gauge steel–concrete hybrid structure, including light gauge steel structure and concrete hybrid structure, is a new–type steel–concrete hybrid structure, which possesses some advantages of light gauge steel structure and concrete hybrid structure. The seismic behavior and loss assessment of three high–rise buildings with three different concrete hybrid structures were investigated through finite element software, respectively. The three concrete hybrid structures are reinforced concrete column–steel beam (RC‒S) hybrid structure, concrete–filled steel tube column–steel beam (CFST‒S) hybrid structure, and tubed concrete column–steel beam (TC‒S) hybrid structure. The nonlinear time-history analysis of three high–rise buildings under 80 earthquakes was carried out. After simulation, it indicated that the seismic performances of three high–rise buildings were superior. Under extremely rare earthquakes, the maximum inter–storey drifts of three high–rise buildings are significantly lower than 1/50. The inter–storey drift and floor acceleration of high–rise building with CFST‒S hybrid structure were bigger than those of high–rise buildings with RC‒S hybrid structure, and smaller than those of high–rise building with TC‒S hybrid structure. Then, based on the time–history analysis results, the post-earthquake repair cost ratio and repair time of three high–rise buildings were predicted through an economic performance analysis method proposed in FEMA‒P58 report. Under frequent earthquakes, basic earthquakes and rare earthquakes, the repair cost ratio and repair time of three high-rise buildings were less than 5% and 15 days, respectively. Under extremely rare earthquakes, the repair cost ratio and repair time of high-rise buildings with TC‒S hybrid structure were the most among three high rise buildings. Due to the advantages of CFST-S hybrid structure, it could be extensively employed in high-rise buildings subjected to earthquake excitations.

Keywords: seismic behavior, loss assessment, light gauge steel–concrete hybrid structure, high–rise building, time–history analysis

Procedia PDF Downloads 155

Authors: Rachit Ahuja, Ayush Chugh

Abstract:

Aerodynamic forces and moments, as well as tire-road forces largely affects the maneuverability of the vehicle. Car manufacturers are largely fascinated and influenced by various aerodynamic improvements made in formula cars. There is constant effort of applying these aerodynamic improvements in road vehicles. In motor racing, the key differentiating factor in a high performance car is its ability to maintain highest possible acceleration in appropriate direction. One of the main areas of concern in motor racing is balance of aerodynamic forces and stream line the flow of air across the body of the vehicle. At present, formula racing cars are regulated by stringent FIA norms, there are constrains for dimensions of the vehicle, engine capacity etc. So one of the fields in which there is a large scope of improvement is aerodynamics of the vehicle. In this project work, an attempt has been made to design a formula- student (FS) car, improve its aerodynamic characteristics through steady state CFD simulations and simultaneously calculate its lap time. Initially, a CAD model of a formula student car is made using SOLIDWORKS as per the given dimensions and a steady-state external air-flow simulation is performed on the baseline model of the formula student car without any add on device to evaluate and analyze the air-flow pattern around the car and aerodynamic forces using FLUENT Solver. A detailed survey on different add-on devices used in racing application like: - front wing, diffuser, shark pin, T- wing etc. is made and geometric model of these add-on devices are created. These add-on devices are assembled with the baseline model. Steady state CFD simulations are done on the modified car to evaluate the aerodynamic effects of these add-on devices on the car. Later comparison of lap time simulation of the formula student car with and without the add-on devices is done with the help of MATLAB. Aerodynamic performances like: - lift, drag and their coefficients are evaluated for different configuration and design of the add-on devices at different speed of the vehicle. From parametric CFD simulations on formula student car attached with add-on devices, there is a considerable amount of drag and lift force reduction besides streamlining the airflow across the car. The best possible configuration of these add-on devices is obtained from these CFD simulations and also use of these add-on devices have shown an improvement in performance of the car which can be compared by various lap time simulations of the car.

Keywords: aerodynamic performance, front wing, laptime simulation, t-wing

Procedia PDF Downloads 177

Authors: Rodrigo Antunes, Olga Borisevich, David Demange

Abstract:

In future nuclear fusion reactors, tritium self-sufficiency will be ensured by tritium (3H) production via reactions between the fusion neutrons and lithium. To favor tritium breeding, a neutron multiplier must also be used. Both tritium breeder and neutron multiplier will be placed in the so-called Breeding Blanket (BB). For the European Helium-Cooled Pebble Bed (HCPB) BB concept, the tritium production and neutron multiplication will be ensured by neutron bombardment of Li4SiO4 and Be pebbles, respectively. The produced tritium is extracted from the pebbles by purging them with large flows of He (~ 104 Nm3h-1), doped with small amounts of H2 (~ 0.1 vol%) to promote tritium extraction via isotopic exchange (producing HT). Due to the presence of oxygen in the pebbles, production of tritiated water is unavoidable. Therefore, the purging gas downstream of the BB will be composed by Q2/Q2O/He (Q = 1H, 2H, 3H), with Q2/Q2O down to ppm levels, which must be further processed for tritium recovery. A two-stage continuous approach, where zeolite membranes (ZMs) are followed by a catalytic membrane reactor (CMR), has been recently proposed to fulfil this task. The tritium recovery from Q2/Q2O/He is ensured by the CMR, that requires a reduction of the gas flow coming from the BB and a pre-concentration of Q2 and Q2O to be efficient. For this reason, and to keep this stage with reasonable dimensions, ZMs are required upfront to reduce as much as possible the He flows and concentrate the Q2/Q2O species. Therefore, experimental activities have been carried out at the Tritium Laboratory Karlsruhe (TLK) to test the separation performances of different zeolite membranes for H2/H2O/He. First experiments have been performed with binary mixtures of H2/He and H2O/He with commercial MFI-ZSM5 and NaA zeolite-type membranes. Only the MFI-ZSM5 demonstrated selectivity towards H2, with a separation factor around 1.5, and H2 permeances around 0.72 µmolm-2s-1Pa-1, rather independent for feed concentrations in the range 0.1 vol%-10 vol% H2/He. The experiments with H2O/He have demonstrated that the separation factor towards H2O is highly dependent on the feed concentration and temperature. For instance, at 0.2 vol% H2O/He the separation factor with NaA is below 2 and around 1000 at 5 vol% H2O/He, at 30°C. Overall, both membranes demonstrated complementary results at equivalent temperatures. In fact, at low feed concentrations ( ≤ 1 vol% H2O/He) MFI-ZSM5 separates better than NaA, whereas the latter has higher separation factors for higher inlet water content ( ≥ 5 vol% H2O/He). In this contribution, the results obtained with both MFI-ZSM5 and NaA membranes for H2/He and H2O/H2 mixtures at different concentrations and temperatures are compared and discussed.

Keywords: nuclear fusion, gas separation, tritium processes, zeolite membranes

Procedia PDF Downloads 269

Authors: Gabriela Rivadeneyra-Romero, Claudia del C. Gutierrez Torres, Sergio A. Martinez-Delgadillo, Victor X. Mendoza-Escamilla, Alejandro Alonzo-Garcia

Abstract:

Ultrasonic degradation is currently being used in sonochemical reactors to degrade pollutant compounds from aqueous media, as emerging contaminants (e.g. pharmaceuticals, drugs and personal care products.) because they can produce possible ecological impacts on the environment. For this reason, it is important to develop appropriate water and wastewater treatments able to reduce pollution and increase reuse. Pollutants such as textile dyes, aromatic and phenolic compounds, cholorobenzene, bisphenol-A and carboxylic acid and other organic pollutants, can be removed from wastewaters by sonochemical oxidation. The effect on the removal of pollutants depends on the type of the ultrasonic frequency used; however, not much studies have been done related to the behavior of the fluid into the sonoreactors operated at different ultrasonic frequencies. Based on the above, it is necessary to study the hydrodynamic behavior of the liquid generated by the ultrasonic irradiation to design efficient sonoreactors to reduce treatment times and costs. In this work, it was studied the hydrodynamic behavior of the fluid in sonochemical reactors at different frequencies (250 kHz, 500 kHz and 1000 kHz). The performances of the sonoreactors at those frequencies were simulated using computational fluid dynamics (CFD). Due to there is great sound speed gradient between piezoelectric and fluid, k-e models were used. Piezoelectric was defined as a vibration surface, to evaluate the different frequencies effect on the fluid into sonochemical reactor. Structured hexahedral cells were used to mesh the computational liquid domain, and fine triangular cells were used to mesh the piezoelectric transducers. Unsteady state conditions were used in the solver. Estimation of the dissipation rate, flow field velocities, Reynolds stress and turbulent quantities were evaluated by CFD and 2D-PIV measurements. Test results show that there is no necessary correlation between an increase of the ultrasonic frequency and the pollutant degradation, moreover, the reactor geometry and power density are important factors that should be considered in the sonochemical reactor design.

Keywords: CFD, reactor, ultrasound, wastewater

Procedia PDF Downloads 172

Authors: Evren Isen

Abstract:

In grid-connected renewable energy systems, input power is controlled by AC/DC converter or/and DC/DC converter depending on output voltage of input source. The power is injected to DC-link, and DC-link voltage is regulated by inverter controlling the grid current. Inverter performance is considerable in grid-connected renewable energy systems to meet the utility standards. In this paper, modelling and simulation of hysteresis current controlled single-phase grid-connected inverter that is utilized in renewable energy systems, such as wind and solar systems, are presented. 2 kW single-phase grid-connected inverter is simulated in Simulink and modeled in Matlab-m-file. The grid current synchronization is obtained by phase locked loop (PLL) technique in dq synchronous rotating frame. Although dq-PLL can be easily implemented in three-phase systems, there is difficulty to generate β component of grid voltage in single-phase system because single-phase grid voltage exists. Inverse-Park PLL with low-pass filter is used to generate β component for grid angle determination. As grid current is controlled by constant bandwidth hysteresis current control (HCC) technique, average switching frequency and variation of switching frequency in a fundamental period are considered. 3.56% total harmonic distortion value of grid current is achieved with 0.5 A bandwidth. Average value of switching frequency and total harmonic distortion curves for different hysteresis bandwidth are obtained from model in m-file. Average switching frequency is 25.6 kHz while switching frequency varies between 14 kHz-38 kHz in a fundamental period. The average and maximum frequency difference should be considered for selection of solid state switching device, and designing driver circuit. Steady-state and dynamic response performances of the inverter depending on the input power are presented with waveforms. The control algorithm regulates the DC-link voltage by adjusting the output power.

Keywords: grid-connected inverter, hysteresis current control, inverter modelling, single-phase inverter

Procedia PDF Downloads 459

Authors: Mlondi Ndovela

Abstract:

Globally, the manufacturing employment has been declining and the South African manufacturing sector experiences the very same trend. Despite the commonality between the global and South African manufacturing trend, there is an understanding that local areas provide distinct contributions to the provincial/national economy. Therefore, the growth/decline of a particular manufacturing division in one local area may not be evident in another area since economic performances vary from region to region. In view of the above, the study employed the Esteban-Marquillas model of shift-share analysis (SSA) to conduct an empirical analysis of manufacturing employment performance at uMhlathuze Local Municipality in the KwaZulu-Natal province. The study set out two objectives; those are, to quantify uMhlathuze manufacturing jobs that are attributed to the provincial manufacturing employment trends and identify manufacturing divisions are growing/declining in terms of employment. To achieve these objectives, the study sampled manufacturing employment data from 2010 to 2017 and this data was categorised into ten manufacturing divisions. Furthermore, the Esteban-Marquillas model calculated manufacturing employment in terms of two effects, namely; provincial growth effect (PGE) and industrial mix effect (IME). The results show that even though uMhlathuze manufacturing sector has a positive PGE (+230), the municipality performed poorly in terms of IME (-291). A further analysis included other economic sectors of the municipality to draw employment performance comparison and the study found that agriculture; construction; trade, catering and accommodation; and transport, storage and communication, performed well above manufacturing sector in terms of PGE (+826) and IME (+532). This suggests that uMhlathuze manufacturing sector is not necessarily declining; however, other economic sectors are growing faster and bigger than it is, therefore, reducing the employment share of the manufacturing sector. To promote manufacturing growth from a policy standpoint, the government could create favourable macroeconomic policies such as import substitution policies and support labour-intensive manufacturing divisions. As a result, these macroeconomic policies can help to protect local manufacturing firms and stimulate the growth of manufacturing employment.

Keywords: allocation effect, Esteban-Marquillas model, manufacturing employment, regional competitive effect, shift-share analysis

Procedia PDF Downloads 122

Authors: Stefano Barone

Abstract:

Seismic retrofit of buildings through base isolation represents a consolidated protection strategy against earthquakes. It consists in decoupling the ground motion from that of the structure and introducing anti-seismic devices at the base of the building, characterized by high horizontal flexibility and medium/high dissipative capacity. This allows to protect structural elements and to limit damages to non-structural ones. For these reasons, full functionality is guaranteed after an earthquake event. Base isolation is applied extensively to both new and existing buildings. For the latter, it usually does not require any interruption of the structure use and occupants evacuation, a special advantage for strategic buildings such as schools, hospitals, and military buildings. This paper describes the application of seismic isolation to three existing masonry buildings in Italy: Villa “La Maddalena” in Macerata (Marche region), “Giacomo Matteotti” and “Plinio Il Giovane” school buildings in Perugia (Umbria region). The seismic hazard of the sites is characterized by a Peak Ground Acceleration (PGA) of 0.213g-0.287g for the Life Safety Limit State and between 0.271g-0.359g for the Collapse Limit State. All the buildings are isolated with a combination of free sliders type TETRON® CD with confined elastomeric disk and anti-seismic rubber isolators type ISOSISM® HDRB to reduce the eccentricity between the center of mass and stiffness, thus limiting torsional effects during a seismic event. The isolation systems are designed to lengthen the original period of vibration (i.e., without isolators) by at least three times and to guarantee medium/high levels of energy dissipation capacity (equivalent viscous damping between 12.5% and 16%). This allows the structures to resist 100% of the seismic design action. This article shows the performances of the supplied anti-seismic devices with particular attention to the experimental dynamic response. Finally, a special focus is given to the main site activities required to isolate a masonry building.

Keywords: retrofit, masonry buildings, seismic isolation, energy dissipation, anti-seismic devices

Procedia PDF Downloads 46

Authors: Md. Abdul Aziz

Abstract:

Sulfide ion is water soluble, highly corrosive, toxic and harmful to the human beings. As a result, knowing the exact concentration of sulfide in water is very important. However, the existing detection and quantification methods have several shortcomings, such as high cost, low sensitivity, and massive instrumentation. Consequently, the development of novel sulfide sensor is relevant. Nevertheless, electrochemical methods gained enormous popularity due to a vast improvement in the technique and instrumentation, portability, low cost, rapid analysis and simplicity of design. Successful field application of electrochemical devices still requires vast improvement, which depends on the physical, chemical and electrochemical aspects of the working electrode. The working electrode made of bulk gold (Au) and platinum (Pt) are quite common, being very robust and endowed with good electrocatalytic properties. High cost, and electrode poisoning, however, have so far hindered their practical application in many industries. To overcome these obstacles, we developed a sulfide sensor based on an indium tin oxide nanoparticle (ITONP)-modified ITO electrode. To prepare ITONP-modified ITO, various methods were tested. Drop-drying of ITONPs (aq.) on aminopropyltrimethoxysilane-functionalized ITO (APTMS/ITO) was found to be the best method on the basis of voltammetric analysis of the sulfide ion. ITONP-modified APTMS/ITO (ITONP/APTMS/ITO) yielded much better electrocatalytic properties toward sulfide electro-οxidation than did bare or APTMS/ITO electrodes. The ITONPs and ITONP-modified ITO were also characterized using transmission electron microscopy and field emission scanning electron microscopy, respectively. Optimization of the type of inert electrolyte and pH yielded an ITONP/APTMS/ITO detector whose amperometrically and chronocoulοmetrically determined limits of detection for sulfide in aqueous solution were 3.0 µM and 0.90 µM, respectively. ITONP/APTMS/ITO electrodes which displayed reproducible performances were highly stable and were not susceptible to interference by common contaminants. Thus, the developed electrode can be considered as a promising tool for sensing sulfide.

Keywords: amperometry, chronocoulometry, electrocatalytic properties, ITO-nanoparticle-modified ITO, sulfide sensor

Procedia PDF Downloads 106

Authors: Ugwuowo Leonard Chidi, Oparaji Chetachukwu Jecinta., Ogidi Chibuzor Agafenachukwu, Onuoha Rebecca Obianuju

Abstract:

This experiment was conducted to investigate the growth performance, haematology and serum biochemistry indices of broiler birds fed diets containing Neem leaf meal. A total of 96 unsexed day-old broiler birds were allocated to four treatments of T1, T2, T3 and T4 and replicated three times with eight birds per replicate in a Completely Randomized Design. The treatments were diets containing 2.0, 4.0, 6.0 and 8.0% Neem leaf meal respectively. Growth performances, packed cell volume, red blood cell count, haemoglobin, white blood cell count, lymphocytes, mean corpuscular volume, mean corpuscular haemoglobin concentration, platelet count, aspartate amino transaminase, alanine amino transaminase, alkaline phosphate, cholesterol, albumin, globulin, urea, glucose, total protein and creatinine were evaluated. Results showed that there were no significant differences (P>0.05) in all the growth performance parameters among the treatments. The results of the experiment showed that there were significant differences (P<0.05) in all the heamatological and serum biochemistry parameters at finisher phases. Mean corpuscular volume, white blood cell count, lymphocytes, red blood cell count, haemoglobin, platelet count, creatinine and triglyceride increased and were highest in treatment two while treatment four had the least values in mean corpuscular volume, urea, white blood cell, haemoglobin and triglyceride. This implies that the levels of inclusion of Neem leaf meal in this experiment did not affect the growth performance of the broiler chicks but the haematological and serum biochemistry indices were affected. Treatment two with a 4% inclusion level of Neem leaf meal has shown the capacity to replace vaccines and antibiotics in broilers due to the positive effects it had on both the haematological and serum biochemistry.

Keywords: leaf meal, broiler, Aziradicta indica, serum biochemistry, haematology

Procedia PDF Downloads 44

Authors: G. St-Pierre-Lemieux, E. Askari Mahvelati, D. Groleau, P. Proulx

Abstract:

Mathematical modeling has become an important tool for the study of foam behavior. Computational Fluid Dynamic (CFD) can be used to investigate the behavior of foam around foam breakers to better understand the mechanisms leading to the ‘destruction’ of foam. The focus of this investigation was the simple cone foam breaker, whose performance has been identified in numerous studies. While the optimal pumping angle is known from the literature, the contribution of pressure drop, shearing, and centrifugal forces to the foam syneresis are subject to speculation. This work provides a screening of those factors against changes in the cone angle and foam rheology. The CFD simulation was made with the open source OpenFOAM toolkits on a full three-dimensional model discretized using hexahedral cells. The geometry was generated using a python script then meshed with blockMesh. The OpenFOAM Volume Of Fluid (VOF) method was used (interFOAM) to obtain a detailed description of the interfacial forces, and the model k-omega SST was used to calculate the turbulence fields. The cone configuration allows the use of a rotating wall boundary condition. In each case, a pair of immiscible fluids, foam/air or water/air was used. The foam was modeled as a shear thinning (Herschel-Buckley) fluid. The results were compared to our measurements and to results found in the literature, first by computing the pumping rate of the cone, and second by the liquid break-up at the exit of the cone. A 3D printed version of the cones submerged in foam (shaving cream or soap solution) and water, at speeds varying between 400 RPM and 1500 RPM, was also used to validate the modeling results by calculating the torque exerted on the shaft. While most of the literature is focusing on cone behavior using Newtonian fluids, this works explore its behavior in shear thinning fluid which better reflects foam apparent rheology. Those simulations bring new light on the cone behavior within the foam and allow the computation of shearing, pressure, and velocity of the fluid, enabling to better evaluate the efficiency of the cones as foam breakers. This study contributes to clarify the mechanisms behind foam breaker performances, at least in part, using modern CFD techniques.

Keywords: bioreactor, CFD, foam breaker, foam mitigation, OpenFOAM

Procedia PDF Downloads 184

Authors: Jonas Sanon

Abstract:

The valorization of research is becoming a transversal instrument linking different sectors (academic, public and industrial). The practice of valorization seems to impact innovation techniques within companies where, there is often the implementation of industrial conventions of training through research (CIFRE), continuous training programs for employees, collaborations and partnerships around joint research and R&D laboratories focused on the needs of companies to improve or develop more efficient innovations. Furthermore, many public initiatives to support innovation and technology transfer have been developed at the international, European and national levels, with significant budget allocations. Thus, in the context of this work, we tried to analyze the way in which research transfer structures are evaluated within the Saclay ecosystem. In fact, the University-Paris-Saclay is one of the best French universities; it is made up of 10 university components, more than 275 laboratories and is in partnership with the largest French research centers This work mainly focused on how evaluations affected research transfer structures, how evaluations were conducted, and what the managers of research transfer structures thought about assessments. Thus, with the aid of the conducted interviews, it appears that the evaluations do not have a significant impact on the qualitative aspect of research and innovation, but is rather present a directive aspect to allow the structures to benefit or not from the financial resources to develop certain research work, sometimes directed and influenced by the market, some researchers might try to accentuate their research and experimentation work on themes that are not necessarily their areas of interest, but just to comply with the calls for proposed thematic projects. The field studies also outline the primary indicators used to assess the effectiveness of valorization structures as "the number of start-ups generated, the license agreements signed, the structure's patent portfolio, and the innovations of items developed from public research.". Finally, after mapping the actors, it became clear that the ecosystem of the University of Paris-Saclay benefits from a richness allowing it to better value its research in relation to the three categories of actors it has (internal, external and transversal), united and linked by a relationship of proximity of sharing and endowed with a real opportunity to innovate openly.

Keywords: research valorization, technology transfer, innovation, evaluation, impacts and performances, innovation policy

Procedia PDF Downloads 45

Authors: Maor Farid, Oleg Gendelman

Abstract:

Equivalent mechanical model of liquid sloshing in partially-filled cylindrical vessel is treated in the cases of free oscillations and of horizontal base excitation. The model is designed to cover both the linear and essentially nonlinear sloshing regimes. The latter fluid behaviour might involve hydraulic impacts interacting with the inner walls of the tank. These impulsive interactions are often modeled by high-power potential and dissipation functions. For the sake of analytical description, we use the traditional approach by modeling the impacts with velocity-dependent restitution coefficient. This modelling is similar to vibro-impact nonlinear energy sink (VI NES) which was recently explored for its vibration mitigation performances and nonlinear response regimes. Steady-state periodic regimes and chaotic strongly modulated responses (CSMR) are detected. Those dynamical regimes were described by the system's slow motion on the slow invariant manifold (SIM). There is a good agreement between the analytical results and numerical simulations. Subsequently, Finite-Element (FE) method is used to determine and verify the model parameters and to identify dominant dynamical regimes, natural modes and frequencies. The tank failure modes are identified and critical locations are identified. Mathematical relation is found between degrees-of-freedom (DOFs) motion and the mechanical stress applied in the tank critical section. This is the prior attempt to take under consideration large-amplitude nonlinear sloshing and tank structure elasticity effects for design, regulation definition and resistance analysis purposes. Both linear (tuned mass damper, TMD) and nonlinear (nonlinear energy sink, NES) passive energy absorbers contribution to the overall system mitigation is firstly examined, in terms of both stress reduction and time for vibration decay.

Keywords: nonlinear energy sink (NES), reduced-order modelling, liquid sloshing, vibration mitigation, vibro-impact dynamics

Procedia PDF Downloads 126

Authors: H. Ferfera-Harrar, T. Benhalima, D. Lerari

Abstract:

Contamination of water, due to the discharge of untreated industrial wastewaters into the ecosystem, has become a serious problem for many countries. In this study, bioadsorbents based on chitosan-g-poly(acrylamide) and montmorillonite (MMt) clay (CTS-g-PAAm/MMt) hydrogel nanocomposites were prepared via free‐radical grafting copolymerization and crosslinking of acrylamide monomer (AAm) onto natural polysaccharide chitosan (CTS) as backbone, in presence of various contents of MMt clay as nanofiller. Then, they were hydrolyzed to obtain highly functionalized pH‐sensitive nanomaterials with uppermost swelling properties. Their structure characterization was conducted by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) analyses. The adsorption performances of the developed nanohybrids were examined for removal of methylene blue (MB) cationic dye from aqueous solutions. The factors affecting the removal of MB, such as clay content, pH medium, adsorbent dose, initial dye concentration and temperature were explored. The adsorption process was found to be highly pH dependent. From adsorption kinetic results, the prepared adsorbents showed remarkable adsorption capacity and fast adsorption rate, mainly more than 88% of MB removal efficiency was reached after 50 min in 200 mg L^-1 of dye solution. In addition, the incorporating of various content of clay has enhanced adsorption capacity of CTS-g-PAAm matrix from 1685 to a highest value of 1749 mg g^-1 for the optimized nanocomposite containing 2 wt.% of MMt. The experimental kinetic data were well described by the pseudo-second-order model, while the equilibrium data were represented perfectly by Langmuir isotherm model. The maximum Langmuir equilibrium adsorption capacity (q_m) was found to increase from 2173 mg g⁻¹ until 2221 mg g⁻¹ by adding 2 wt.% of clay nanofiller. Thermodynamic parameters revealed the spontaneous and endothermic nature of the process. In addition, the reusability study revealed that these bioadsorbents could be well regenerated with desorption efficiency overhead 87% and without any obvious decrease of removal efficiency as compared to starting ones even after four consecutive adsorption/desorption cycles, which exceeded 64%. These results suggest that the optimized nanocomposites are promising as low cost bioadsorbents.

Keywords: chitosan, clay, dye adsorption, hydrogels nanocomposites

Procedia PDF Downloads 102

Authors: L. Vivet, L. Benabou, O. Simon

Abstract:

With highly demanding applications in the field of power electronics, there is an increasing need to have interconnection materials with properties that can ensure both good mechanical assembly and high thermal/electrical conductivities. So far, lead-free solders have been considered an attractive solution, but recently, sintered joints based on nano-silver paste have been used for die attach and have proved to be a promising solution offering increased performances in high-temperature applications. In this work, the main parameters of the bonding process using silver oxalates are studied, i.e., the heating rate and the bonding pressure mainly. Their effects on both the mechanical and thermal properties of the sintered layer are evaluated following an experimental design. Pairs of copper substrates with gold metallization are assembled through the sintering process to realize the samples that are tested using a micro-traction machine. In addition, the obtained joints are examined through microscopy to identify the important microstructural features in relation to the measured properties. The formation of an intermetallic compound at the junction between the sintered silver layer and the gold metallization deposited on copper is also analyzed. Microscopy analysis exhibits a nanoporous structure of the sintered material. It is found that higher temperature and bonding pressure result in higher densification of the sintered material, with higher thermal conductivity of the joint but less mechanical flexibility to accommodate the thermo-mechanical stresses arising during service. The experimental design allows hence the determination of the optimal process parameters to reach sufficient thermal/mechanical properties for a given application. It is also found that the interphase formed between silver and gold metallization is the location where the fracture occurred after the mechanical testing, suggesting that the inter-diffusion mechanism between the different elements of the assembly leads to the formation of a relatively brittle compound.

Keywords: nanoporous structure, silver oxalate, sintering, mechanical strength, thermal conductivity, microelectronic packaging

Procedia PDF Downloads 75

Authors: Masahiro Nochi

Abstract:

This study explores the process in which a Japanese child with congenital blindness deepens understanding of the condition of being “unable to see” and develops the idea of “blind self,” despite having no direct experience of vision. The rehabilitation activities of a child with a congenital visual impairment that were video-recorded from 1 to 6 years old were analyzed qualitatively. The duration of the video was about 80 hours. The recordings were transcribed verbatim, and the episodes in which the child used the words related to the act of “looking” were extracted. Detailed transcripts were constructed referencing the notations of conversation analysis. Characteristics of interactions in those episodes were identified and compared longitudinally. Results showed that the child used the expression "look" under certain interaction patterns and her body expressions and interaction with adults developed in conjunction with the development of language use. Four stages were identified. At the age of 1, interactions involving “look” began to occur. The child said "Look" in the sequence: the child’s “Look,” an adult’s “I’m looking,” certain performances by the child, and the adult’s words of praise. At the age of 3, the child began to behave in accordance with the spatial attributes of the act of "looking," such as turning her face to the adult’s voice before saying, “Look.” She also began to use the expression “Keep looking,” which seemed to reflect her understanding of the temporality of the act of “looking.” At the age of 4, the use of “Look” or “Keep looking” became three times more frequent. She also started to refer to the act of looking in the future, such as “Come and look at my puppy someday.” At the age of 5, she moved her hands toward the adults when she was holding something she wanted to show them. She seemed to understand that people could see the object more clearly when it was in close priximity. About that time, she began to say “I cannot see” to her mother, which suggested a heightened understanding of her own blindness. The findings indicate that as she grew up, the child came to utilize nonverbal behavior before and after the order "Look" to make the progress of the interaction with adults even more certain. As a result, actions that reflect the characteristics of the sighted person's visual experience were incorporated into the interaction chain. The purpose of "Look," with which she intended to attract the adult's attention at first, changed and became something that requests a confirmation she was unable to make herself. It is considered that such a change in the use of the word as well as interaction with sighted adults reflected her heightened self-awareness as someone who could not do what sighted people could do easily. A blind child can gradually deepen their understanding of their own characteristics of blindness among sighted people around them. The child can also develop “blind self” by learning how to interact with others even without direct visual experiences.

Keywords: blindness, child development, conversation analysis, self-concept

Procedia PDF Downloads 101

Authors: U. Gunal, H. I. Turgut, H. Gurler, S. Kaya

Abstract:

There are many ever-increasing and newly emerging problems with rapid population growth in the world. With the increase in people's quality of life in our daily life, acoustic comfort has become an important feature in the textile industry. In order to meet all these expectations in people's comfort areas and survive in challenging competitive conditions in the market without compromising the customer product quality expectations of textile manufacturers, it has become a necessity to bring functionality to the products. It is inevitable to research and develop materials and processes that will bring these functionalities to textile products. The noise we encounter almost everywhere in our daily life, in the street, at home and work, is one of the problems which textile industry is working on. It brings with it many health problems, both mentally and physically. Therefore, noise control studies become more of an issue. Besides, materials used in noise control are not sufficient to reduce the effect of the noise level. The fabrics used in acoustic studies in the textile industry do not show sufficient performance according to their weight and high cost. Thus, acoustic textile products can not be used in daily life. In the thesis study, the attributions used in the noise control and building acoustics studies in the literature were analyzed, and the product with the highest damping value that a textile material will have was designed, manufactured, and tested. Optimum values were obtained by using different material samples that may affect the performance of the acoustic material. Acoustic measurement methods should be applied to verify the acoustic performances shown by the parameters and the designed three-dimensional structure at different values. In the measurements made in the study, the device designed for determining the acoustic performance of the material for both the impedance tube according to the relevant standards and the different noise types in the study was used. In addition, sound records of noise types encountered in daily life are taken and applied to the acoustic absorbent fabric with the aid of the device, and the feasibility of the results and the commercial ability of the product are examined. MATLAB numerical computing programming language and libraries were used in the frequency and sound power analyses made in the study.

Keywords: acoustic, egg crate, fabric, textile

Procedia PDF Downloads 85

Authors: Ayhan Varol, Aysenur Ugurlu

Abstract:

Due to the depletion of fossil fuels and climate change, there is a rising interest in renewable energy sources. In this concept, a wide range of biomass (energy crops, animal manure, solid wastes, etc.) are used for energy production. There has been a growing interest in biomethane production from biomass. Biomethane production from organic wastes is a promising alternative for waste management by providing organic matter stabilization. Anaerobic digestion of organic material produces biogas, and organic substrate is degraded into a more stable material. Therefore, anaerobic digestion technology helps reduction of carbon emissions and produces renewable energy. The hydraulic retention time (HRT) and organic loading rate (OLR), as well as TS (VS) loadings, influences the anaerobic digestion of organic wastes significantly. The optimum range for HRT varies between 15 days to 30 days, whereas OLR differs between 0.5 to 5 g/L.d depending on the substrate type and its lipid, protein and carbohydrate contents. The organic wastes have biogas production potential through anaerobic digestion. In this study, biomethane production potential of wastes like sugar beet bagasse, agricultural residues, food wastes, olive mill pulp, and dairy manure having different characteristics was investigated in mesophilic CSTR reactor, and their performances were compared. The reactor was mixed in order to provide homogenized content at a rate of 80 rpm. The organic matter content of these wastes was between 85 to 94 % with 61% (olive pulp) to 22 % (food waste) dry matter content. The hydraulic retention time changed between 20-30 days. High biogas productions, 13.45 to 5.70 mL/day, were achieved from the wastes studied when operated at 9 to 10.5% TS loadings where OLR varied between 2.92 and 3.95 gVS/L.day. The results showed that food wastes have higher specific methane production rate and volumetric methane production potential than the other wastes studied, under the similar OLR values. The SBP was 680, 585, 540, 390 and 295 mL/g VS for food waste, agricultural residues, sugar beet bagasse, olive pulp and dairy manure respectively. The methane content of the biogas varied between 72 and 60 %. The volatile solids conversion rate for food waste was 62%.

Keywords: biogas production, organic wastes, biomethane, anaerobic digestion

Procedia PDF Downloads 254

Authors: I. A. Yola

Abstract:

Impact of poultry dropping, cow dung and rumen content on utilization and proximate composition of Oreochromis niliticus, Clarias gariepinus and Cyprinus capio in a polyculture system were studied. The research was conducted over a period of 52 weeks. Poultry droppings (PD), cow dung (CD) and rumen content (RC) were applied at three levels 30g,60g and 120g/m2/week, 25g,50g and 100g/m2/week and 22g, 44g and 88g/m2/week treatment, respectively. The control only conventional feed with 40% CP without manure application was used. Physicochemical and biological properties measured were higher in manure pond than control. The difference was statistically significant (P < 0.05) between and within treatments with exception of temperature with a combined mean of 27.900C. The water was consistently alkaline with mean values for pH of 6.61, transparency 22.6cm, conductivity 35.00µhos/cm, dissolved oxygen 4.6 mg/l, biological oxygen demand 2.8mg/l, nitrate and phosphates 0.9mg/l and 0.35mg/l, respectively. The three fish species increase in weight with increased manure rate, with a higher value in PD treatment on C. capio record 340g, O. niloticus weighed 310g and C. gariepinus 280g over the experimental period. Fishes fed supplementary diet (control) grew bigger with highest value on C. capio (685g) O. niloticus (620g) and then C. gariepinus (526g). The differences were statistically significant (P < 0.05). The result of whole body proximate analysis indicated that various manures and rates had an irregular pattern on the protein and ash gain per 100g of fish body weight gain. The combined means for whole fish carcass protein, lipids, moisture, ash and gross energy were 11.84, 2.43, 74.63, 3.00 and 109.9 respectively. The notable exceptions were significant (p < 0.05) increases in body fat and gross energy gains in all fish species accompanied by decreases in percentages of moisture as manure rates increased. Survival percentage decreases from 80% to 70%. It is recommended to use poultry dropping as manure/feeds at the rate of 120kg/ha/week for good performances in polyculture.

Keywords: organic manure, Nile tilapia, African mud fish, common carp, proximate composition

Procedia PDF Downloads 524