Search results for: diagnostic tests
1084 Seismic Protection of Automated Stocker System by Customized Viscous Fluid Dampers
Authors: Y. P. Wang, J. K. Chen, C. H. Lee, G. H. Huang, M. C. Wang, S. W. Chen, Y. T. Kuan, H. C. Lin, C. Y. Huang, W. H. Liang, W. C. Lin, H. C. Yu
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The hi-tech industries in the Science Park at southern Taiwan were heavily damaged by a strong earthquake early 2016. The financial loss in this event was attributed primarily to the automated stocker system handling fully processed products, and recovery of the automated stocker system from the aftermath proved to contribute major lead time. Therefore, development of effective means for protection of stockers against earthquakes has become the highest priority for risk minimization and business continuity. This study proposes to mitigate the seismic response of the stockers by introducing viscous fluid dampers in between the ceiling and the top of the stockers. The stocker is expected to vibrate less violently with a passive control force on top. Linear damper is considered in this application with an optimal damping coefficient determined from a preliminary parametric study. The damper is small in size in comparison with those adopted for building or bridge applications. Component test of the dampers has been carried out to make sure they meet the design requirement. Shake table tests have been further conducted to verify the proposed scheme under realistic earthquake conditions. Encouraging results have been achieved by effectively reducing the seismic responses of up to 60% and preventing the FOUPs from falling off the shelves that would otherwise be the case if left unprotected. Effectiveness of adopting a viscous fluid damper for seismic control of the stocker on top against the ceiling has been confirmed. This technique has been adopted by Macronix International Co., LTD for seismic retrofit of existing stockers. Demonstrative projects on the application of the proposed technique are planned underway for other companies in the display industry as well.Keywords: hi-tech industries, seismic protection, automated stocker system, viscous fluid damper
Procedia PDF Downloads 3531083 Parental Drinking and Risky Alcohol Related Behaviors: Predicting Binge Drinking Trajectories and Their Influence on Impaired Driving among College Students
Authors: Shiran Bord, Assaf Oshri, Matthew W. Carlson, Sihong Liu
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Background: Alcohol-impaired driving (AID) and binge drinking are major health concerns among college students. Although the link between binge drinking and AID is well established, knowledge regarding binge drinking patterns, the factors influencing binge drinking, and the associations between consumption patterns and alcohol-related risk behaviors is lacking. Aims: To examine heterogeneous trajectories of binge drinking during college and tests factors that might predict class membership as well as class membership outcomes. Methods: Data were obtained from a sample of 1,265 college students (Mage = 18.5, SD = .66) as part of the Longitudinal Study of Violence Against Women (N = 1,265; 59.3% female; 69.2% white). Analyses were completed in three stages. First, a growth curve analysis was conducted to identify trajectories of binge drinking over time. Second, growth curve mixture modeling analyses were pursued to assess unobserved growth trajectories of binge drinking without predictors. Lastly, parental drinking variables were added to the model as predictors of class membership, and AID and being a passenger of a drunk driver were added to the model as outcomes. Results: Three binge drinking trajectories were identified: high-convex, medium concave and low-increasing. Parental drinking was associated with being in high-convex and medium-concave classes. Compared to the low-increasing class, the high convex and medium concave classes reported more AID and being a passenger of a drunk driver more frequently. Conclusions: Parental drinking may affect children’s later engagement in AID. Efforts should focus on parents' education regarding the consequences of parental modeling of alcohol consumption.Keywords: alcohol impaired driving, alcohol consumption, binge drinking, college students, parental modeling
Procedia PDF Downloads 2801082 The Effect of Vertical Integration on Operational Performance: Evaluating Physician Employment in Hospitals
Authors: Gary Young, David Zepeda, Gilbert Nyaga
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This study investigated whether vertical integration of hospitals and physicians is associated with better care for patients with cardiac conditions. A dramatic change in the U.S. hospital industry is the integration of hospital and physicians through hospital acquisition of physician practices. Yet, there is little evidence regarding whether this form of vertical integration leads to better operational performance of hospitals. The study was conducted as an observational investigation based on a pooled, cross-sectional database. The study sample comprised over hospitals in the State of California. The time frame for the study was 2010 to 2012. The key performance measure was hospitals’ degree of compliance with performance criteria set out by the federal government for managing patients with cardiac conditions. These criteria relate to the types of clinical tests and medications that hospitals should follow for cardiac patients but hospital compliance requires the cooperation of a hospital’s physicians. Data for this measure was obtained from a federal website that presents performance scores for U.S. hospitals. The key independent variable was the percentage of cardiologists that a hospital employs (versus cardiologists who are affiliated but not employed by the hospital). Data for this measure was obtained from the State of California which requires hospitals to report financial and operation data each year including numbers of employed physicians. Other characteristics of hospitals (e.g., information technology for cardiac care, volume of cardiac patients) were also evaluated as possible complements or substitutes for physician employment by hospitals. Additional sources of data included the American Hospital Association and the U.S. Census. Empirical models were estimated with generalized estimating equations (GEE). Findings suggest that physician employment is positively associated with better hospital performance for cardiac care. However, findings also suggest that information technology is a substitute for physician employment.Keywords: physician employment, hospitals, verical integration, cardiac care
Procedia PDF Downloads 3951081 Reinforcing Effects of Natural Micro-Particles on the Dynamic Impact Behaviour of Hybrid Bio-Composites Made of Short Kevlar Fibers Reinforced Thermoplastic Composite Armor
Authors: Edison E. Haro, Akindele G. Odeshi, Jerzy A. Szpunar
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Hybrid bio-composites are developed for use in protective armor through positive hybridization offered by reinforcement of high-density polyethylene (HDPE) with Kevlar short fibers and palm wood micro-fillers. The manufacturing process involved a combination of extrusion and compression molding techniques. The mechanical behavior of Kevlar fiber reinforced HDPE with and without palm wood filler additions are compared. The effect of the weight fraction of the added palm wood micro-fillers is also determined. The Young modulus was found to increase as the weight fraction of organic micro-particles increased. However, the flexural strength decreased with increasing weight fraction of added micro-fillers. The interfacial interactions between the components were investigated using scanning electron microscopy. The influence of the size, random alignment and distribution of the natural micro-particles was evaluated. Ballistic impact and dynamic shock loading tests were performed to determine the optimum proportion of Kevlar short fibers and organic micro-fillers needed to improve impact strength of the HDPE. These results indicate a positive hybridization by deposition of organic micro-fillers on the surface of short Kevlar fibers used in reinforcing the thermoplastic matrix leading to enhancement of the mechanical strength and dynamic impact behavior of these materials. Therefore, these hybrid bio-composites can be promising materials for different applications against high velocity impacts.Keywords: hybrid bio-composites, organic nano-fillers, dynamic shocking loading, ballistic impacts, energy absorption
Procedia PDF Downloads 1111080 Adverse Curing Conditions and Performance of Concrete: Bangladesh Perspective
Authors: T. Manzur
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Concrete is the predominant construction material in Bangladesh. In large projects, stringent quality control procedures are usually followed under the supervision of experienced engineers and skilled labors. However, in the case of small projects and particularly at distant locations from major cities, proper quality control is often an issue. It has been found from experience that such quality related issues mainly arise from inappropriate proportioning of concrete mixes and improper curing conditions. In most cases external curing method is followed which requires supply of adequate quantity of water along with proper protection against evaporation. Often these conditions are found missing in the general construction sites and eventually lead to production of weaker concrete both in terms of strength and durability. In this study, an attempt has been made to investigate the performance of general concreting works of the country when subjected to several adverse curing conditions that are quite common in various small to medium construction sites. A total of six different types of adverse curing conditions were simulated in the laboratory and samples were kept under those conditions for several days. A set of samples was also submerged in normal curing condition having proper supply of curing water. Performance of concrete was evaluated in terms of compressive strength, tensile strength, chloride permeability and drying shrinkage. About 37% and 25% reduction in 28-day compressive and tensile strength were observed respectively, for samples subjected to most adverse curing condition as compared to the samples under normal curing conditions. Normal curing concrete exhibited moderate permeability (close to low permeability) whereas concrete under adverse curing conditions showed very high permeability values. Similar results were also obtained for shrinkage tests. This study, thus, will assist concerned engineers and supervisors to understand the importance of quality assurance during the curing period of concrete.Keywords: adverse, concrete, curing, compressive strength, drying shrinkage, permeability, tensile strength
Procedia PDF Downloads 2001079 The Relation of Motivation and Reward with Volunteer Satisfaction: Empirical Evidence from Omani Non-Profit Organization
Authors: Ali Al Shamli, Talal AlMamari
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Background: The relationship between motivation and satisfaction is posited to be mediated by reward. In this study, the motivation construct was measured by a motivation scale. The scale when factor analysed generated five factors. These factors were referred as; 1) leisure motivation, 2) egoistic motivation, 3) external motivation, 4) purposive, and 5) material motivation. The reward construct was measured by using a five-item scale whereas the satisfaction construct was measured by using a 13-item scale. The scale when factor analysed produced three factors which are referred as; 1) satisfaction A, 2) satisfaction B, and 3) satisfaction C. Objective: The main purpose of the present paper was to find out the relation of motivation and reward with volunteer satisfaction at national sports organizations (NPSOs) in Oman. Methods: This current study adopts a cross-sectional design as the data collection is done only once whereas the mode of administration was postal questionnaire where each questionnaire was posted, completed, and returned using the self-addressed envelope after its completion. The population of the study consisted of (160) boards and directors members of NPSOs (Non-Profit Sports Organization Services) in Oman from all 43 sports club. Results: The findings provided new empirical evidence that supported the argument of the relationship between motivation and satisfaction is indeed, mediated by reward. However, this study differs in that the relationship was tested based on the first-order constructs which were derived from the underlying dimensions of both motivation and satisfaction constructs. It was established that the relationships between motivation B and motivation C with satisfaction A are mediated by reward. Conclusion: In light of study findings, there is a direct relationship between developmental motivation and experiential satisfaction, a direct relationship between social motivation and relational satisfaction, as well as personal motivation and relational satisfaction, is mediated by reward. Therefore, Omani volunteers are less reliant on the reward as evidenced by the direct relationship between motivation A and satisfaction and between motivation C and satisfaction A. More tests in different settings will provide more understanding on volunteer motivation.Keywords: non-profit sports organization, sport and reward, volunteers in sport, satisfaction in sport
Procedia PDF Downloads 4611078 A Hard Day's Night: Persistent Within-Individual Effects of Job Demands and the Role of Recovery Processes
Authors: Helen Pluut, Remus Ilies, Nikos Dimotakis, Maral Darouei
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This study aims to examine recovery from work as an important daily activity with implications for workplace behavior. Building on affective events theory and the stressor-detachment model as frameworks, this paper proposes and tests a comprehensive within-individual model that uncovers the role of recovery processes at home in linking workplace demands (e.g., workload) and stressors (e.g., workplace incivility) to next-day organizational citizenship behaviors (OCBs). Our sample consisted of 126 full-time employees in a large Midwestern University. For a period of 16 working days, these employees were asked to fill out 3 electronic surveys while at work. The first survey (sent out in the morning) measured self-reported sleep quality, recovery experiences the previous day at home, and momentary effect. The second survey (sent out close to the end of the workday) measured job demands and stressors as well as OCBs, while the third survey in the evening assessed job strain. Data were analyzed using Hierarchical Linear Modeling (HLM). Results indicated that job demands and stressors at work made it difficult to unwind properly at home and have a good night’s sleep, which had repercussions for next day’s morning effect, which, in turn, influenced OCBs. It can be concluded that processes of recovery are vital to an individual’s daily effective functioning and behavior at work, but recovery may become impaired after a hard day’s work. Thus, our study sheds light on the potentially persistent nature of strain experienced as a result of work and points to the importance of recovery processes to enable individuals to avoid such cross-day spillover. Our paper will discuss this implication for theory and practice as well as potential directions for future research.Keywords: affect, job demands, organizational citizenship behavior, recovery, strain
Procedia PDF Downloads 1391077 Change in Self-Reported Personality in Students of Acting
Authors: Nemanja D. Kidzin
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The field of personality change has recently garnered increased attention, while the psychology of acting has remained relatively understudied. This research tried to contribute to the both research field by investigating whether the process of acting can lead to personality changes in acting students and, if so, in what manner. It was hypothesized that significant differences would be observed in self-reported personality traits of acting students between the beginning and end of their role preparation. The study also examined potential moderator variables, including the reported personality traits of the roles portrayed by the students, empathy, disintegration, and years of formal acting education. The sample comprised 47 students of acting from the Faculty of Dramatic Arts (first to fourth-year) and the Faculty of Modern Arts (first-year students only). The research involved two waves of testing, conducted at the beginning (T1) and end (T2) of the semester. Personality traits (measured using the HEXACO-60 self-report version), empathy (measured using the Questionnaire of Cognitive and Affective Empathy, QCAE), and disintegration (measured using the DELTA9, 10-item version) were assessed at both T1 and T2, while the personality of the role (measured using the HEXACO-60 observer version) was assessed at T2. Repeated-measures t-tests revealed significant differences in emotionality and conscientiousness between T1 and T2. Additionally, an index of absolute personality change was significantly different from 0 for all traits, indicating personality change. The average test-retest correlation for HEXACO traits was 0.57, lower than that proposed in similar research. However, the personality of the role, empathy, and disintegration did not explain the changes in students' personality traits as moderator variables. The magnitude of personality change was highest among fourth-year students, with no significant differences observed among the remaining three years of study. Overall, the findings suggest the presence of personality changes or trait variability in acting students. However, these changes cannot be conclusively attributed to the process of role preparation. Further research with more stringent methodologies is needed to better understand the role of acting in personality change.Keywords: personality change, psychology of acting, empathy, disintegraton
Procedia PDF Downloads 681076 Public Debt and Fiscal Stability in Nigeria
Authors: Abdulkarim Yusuf
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Motivation: The Nigerian economy has seen significant macroeconomic instability, fuelled mostly by an overreliance on fluctuating oil revenues. The rising disparity between tax receipts and government spending in Nigeria necessitates government borrowing to fund the anticipated pace of economic growth. Rising public debt and fiscal sustainability are limiting the government's ability to invest in key infrastructure that promotes private investment and growth in Nigeria. Objective: This paper fills an empirical research vacuum by examining the impact of public debt on fiscal sustainability in Nigeria, given the significance of fiscal stability in decreasing poverty and the constraints that an unsustainable debt burden imposes on it. Data and method: Annual time series data covering the period 1980 to 2022 exposed to conventional and structural breaks stationarity tests and the Autoregressive Distributed Lag estimation approach were adopted for this study. Results: The results reveal that domestic debt stock, debt service payment, foreign reserve stock, exchange rate, and private investment all had a major adverse effect on fiscal stability in the long and short run, corroborating the debt overhang and crowding-out hypothesis. External debt stock, prime lending rate, and degree of trade openness, which boosted fiscal stability in the long run, had a major detrimental effect on fiscal stability in the short run, whereas foreign direct investment inflows had an important beneficial impact on fiscal stability in both the long and short run. Implications: The results indicate that fiscal measures that inspire domestic resource mobilization, sustainable debt management techniques, and dependence on external debt to boost deficit financing will improve fiscal stability and drive growth.Keywords: ARDL co-integration, debt overhang, debt servicing, fiscal stability, public debt
Procedia PDF Downloads 561075 Factors Associated with Oral Cavity Colonization by Candida albicans
Authors: Nwafia Ifeyinwa Nkeiruka, Nwafia Walter Chukwuma
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Since the early 1980’s fungi have emerged as major causes of human diseases, especially among immunocompromised. The most commonly isolated yeast is Candida albicans and constitutes the 4th most common nosocomial BSI in humans. It is progressive and cumulative and become more complex over time.It can even lead to leaky gut syndrome that causes food and environmental allergies. It is worthy of note that all the available data on oral Candida risk factors in humans were documented essentially using data from studies conducted in other areas, hence there is need for comparative and complementary information from the South eastern part of Nigeria. Method: 200 subjects of all age groups of both sexes were randomly examined,by swabbing their palatine mucosa and dorsal tongue with sterile cotton wool,then cultured into Sabouraud dextrose agar plates supplemented with antibiotics and incubated aerobically at 37 degree for 48 hrs. Identification of Candida albicans was done by germ tubes tests, chlamydospores production on cornmeal agar supplemented with 1% Tween 80.Sugar and nitrogen assimilation test using API 20C Auxanogram and potassium nitrate agar. Results: Out of 30 samples that were positive for candida, 15 (50%) were candida albicans. Using the anova test (P < 0.05) this variation is significant (P = 0016). followed by C. dublinensis 3 (13%), C. tropicalis 3 (10%), C. pseudotropicalis 3 (10%), C, glabrata 2 (7%), C. parapsilosis 2 (7%) and lastly C. krusei 1 (3%).However, 53% of the patients were female while 47% were male. Among the HIV positive isolates.67% were HIV isolates not on drugs while 33% positives isolates were on drugs and the percentages of candida species in these patients were as follows C. albicans were 45% followed by C. glabrata and C.tropicalis which were 17% each, C.parapsilosis, C.dubliensis and C.pseudotropicalis were all 8% each. Conclusion: Oral Candidiasis is a marker of systemic diseases and in some cases, it may be the first clinical presentation. There is need for more intensive clinical and laboratory monitoring and possible early intervention to prevent the reoccurrence and resistance to treatment.Keywords: oral cavity, Candida species, oral Candidiasis, risk factors
Procedia PDF Downloads 3621074 Dynamic Test for Stability of Columns in Sway Mode
Authors: Elia Efraim, Boris Blostotsky
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Testing of columns in sway mode is performed in order to determine the maximal allowable load limited by plastic deformations or their end connections and a critical load limited by columns stability. Motivation to determine accurate value of critical force is caused by its using as follow: - critical load is maximal allowable load for given column configuration and can be used as criterion of perfection; - it is used in calculation prescribed by standards for design of structural elements under combined action of compression and bending; - it is used for verification of theoretical analysis of stability at various end conditions of columns. In the present work a new non-destructive method for determination of columns critical buckling load in sway mode is proposed. The method allows performing measurements during the tests under loads that exceeds the columns critical load without losing its stability. The possibility of such loading is achieved by structure of the loading system. The system is performed as frame with rigid girder, one of the columns is the tested column and the other is additional two-hinged strut. Loading of the frame is carried out by the flexible traction element attached to the girder. The load applied on the tested column can achieve values that exceed the critical load by choice of parameters of the traction element and the additional strut. The system lateral stiffness and the column critical load are obtained by the dynamic method. The experiment planning and the comparison between the experimental and theoretical values were performed based on the developed dependency of lateral stiffness of the system on vertical load, taking into account semi-rigid connections of the column's ends. The agreement between the obtained results was established. The method can be used for testing of real full-size columns in industrial conditions.Keywords: buckling, columns, dynamic method, end-fixity factor, sway mode
Procedia PDF Downloads 3501073 Comparative Proteomic Profiling of Planktonic and Biofilms from Staphylococcus aureus Using Tandem Mass Tag-Based Mass Spectrometry
Authors: Arifur Rahman, Ardeshir Amirkhani, Honghua Hu, Mark Molloy, Karen Vickery
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Introduction and Objectives: Staphylococcus aureus and coagulase-negative staphylococci comprises approximately 65% of infections associated with medical devices and are well known for their biofilm formatting ability. Biofilm-related infections are extremely difficult to eradicate owing to their high tolerance to antibiotics and host immune defences. Currently, there is no efficient method for early biofilm detection. A better understanding to enable detection of biofilm specific proteins in vitro and in vivo can be achieved by studying planktonic and different growth phases of biofilms using a proteome analysis approach. Our goal was to construct a reference map of planktonic and biofilm associated proteins of S. aureus. Methods: S. aureus reference strain (ATCC 25923) was used to grow 24 hours planktonic, 3-day wet biofilm (3DWB), and 12-day wet biofilm (12DWB). Bacteria were grown in tryptic soy broth (TSB) liquid medium. Planktonic growth was used late logarithmic bacteria, and the Centres for Disease Control (CDC) biofilm reactor was used to grow 3 days, and 12-day hydrated biofilms, respectively. Samples were subjected to reduction, alkylation and digestion steps prior to Multiplex labelling using Tandem Mass Tag (TMT) 10-plex reagent (Thermo Fisher Scientific). The labelled samples were pooled and fractionated by high pH RP-HPLC which followed by loading of the fractions on a nanoflow UPLC system (Eksigent UPLC system, AB SCIEX). Mass spectrometry (MS) data were collected on an Orbitrap Elite (Thermo Fisher Scientific) Mass Spectrometer. Protein identification and relative quantitation of protein levels were performed using Proteome Discoverer (version 1.3, Thermo Fisher Scientific). After the extraction of protein ratios with Proteome Discoverer, additional processing, and statistical analysis was done using the TMTPrePro R package. Results and Discussion: The present study showed that a considerable proteomic difference exists among planktonic and biofilms from S. aureus. We identified 1636 total extracellular secreted proteins, of which 350 and 137 proteins of 3DWB and 12DWB showed significant abundance variation from planktonic preparation, respectively. Of these, simultaneous up-regulation in between 3DWB and 12DWB proteins such as extracellular matrix-binding protein ebh, enolase, transketolase, triosephosphate isomerase, chaperonin, peptidase, pyruvate kinase, hydrolase, aminotransferase, ribosomal protein, acetyl-CoA acetyltransferase, DNA gyrase subunit A, glycine glycyltransferase and others we found in this biofilm producer. On the contrary, simultaneous down-regulation in between 3DWB and 12DWB proteins such as alpha and delta-hemolysin, lipoteichoic acid synthase, enterotoxin I, serine protease, lipase, clumping factor B, regulatory protein Spx, phosphoglucomutase, and others also we found in this biofilm producer. In addition, we also identified a big percentage of hypothetical proteins including unique proteins. Therefore, a comprehensive knowledge of planktonic and biofilm associated proteins identified by S. aureus will provide a basis for future studies on the development of vaccines and diagnostic biomarkers. Conclusions: In this study, we constructed an initial reference map of planktonic and various growth phase of biofilm associated proteins which might be helpful to diagnose biofilm associated infections.Keywords: bacterial biofilms, CDC bioreactor, S. aureus, mass spectrometry, TMT
Procedia PDF Downloads 1691072 Listening to the Voices of Teachers Who Are Dyslexic: The Careers, Professional Development, and Strategies Used by of Teachers Who Are Dyslexic
Authors: Jane Mullen
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Little research has been undertaken on adult dyslexia and the impact it has on those who have professional careers. There are many complexities behind the career decisions people make, but for teachers who are dyslexic, it can be even more complex. Dyslexia particularly impacts on written and verbal communication, as well as planning and organisation skills which are essential skills for a teacher. As the teachers are aware of their areas of weakness many, make the conscious decision not to disclose their disability at work. In England, the reduction to three attempts to pass the compulsory English and Maths tests prior to undertaking teacher training may mean that dyslexics are now excluded from trying to enter the profession. Together with the fact that dyslexic teachers often chose to remain ‘hidden’ the situation appears to be counter to the inclusive rhetoric that dominates the current educational discourse. This paper is based on in-depth narrative research that has been undertaken with a small group of teachers who are dyslexic in England and firstly explores the strategies and resources that the teachers have found useful. The narratives of the teachers are full of difficulties as well as diversity, consequently, the paper secondly examines how life experiences have impacted on the way the teachers see their dyslexia and how it affects them professionally. Using a narrative methodology enables the teachers to tell their ‘stories’ of how they feel their dyslexia impacts on their lives professionally. The first interview centred around a limited number of semi structured questions about family background, educational experiences, career development, management roles and professional disclosure. The second interview focused on the complexities of being a teacher who is dyslexic and to ‘unlock’ some of their work based narratives visual elicitation was used. Photographs of work-based strategies, issues or concerns were sent to the researcher and these were used as the basis for discussion in the second interview. The paper concludes by discussing possible reasonable adjustments and professional development that might benefit teachers who are dyslexic.Keywords: dyslexia, life history, narrative, professional, professional development, strategies, teachers
Procedia PDF Downloads 2191071 Load Transfer of Steel Pipe Piles in Warming Permafrost
Authors: S. Amirhossein Tabatabaei, Abdulghader A. Aldaeef, Mohammad T. Rayhani
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As the permafrost continues to melt in the northern regions due to global warming, a soil-water mixture is left behind with drastically lower strength; a phenomenon that directly impacts the resilience of existing structures and infrastructure systems. The frozen soil-structure interaction, which in ice-poor soils is controlled by both interface shear and ice-bonding, changes its nature into a sole frictional state. Adfreeze, the controlling mechanism in frozen soil-structure interaction, diminishes as the ground temperature approaches zero. The main purpose of this paper is to capture the altered behaviour of frozen interface with respect to rising temperature, especially near melting states. A series of pull-out tests are conducted on model piles inside a cold room to study how the strength parameters are influenced by the phase change in ice-poor soils. Steel model piles, embedded in artificially frozen cohesionless soil, are subjected to both sustained pull-out forces and constant rates of displacement to observe the creep behaviour and acquire load-deformation curves, respectively. Temperature, as the main variable of interest, is increased from a lower limit of -10°C up to the point of melting. During different stages of the temperature rise, both skin deformations and temperatures are recorded at various depths along the pile shaft. Significant reduction of pullout capacity and accelerated creep behaviour is found to be the primary consequences of rising temperature. By investigating the different pull-out capacities and deformations measured during step-wise temperature change, characteristics of the transition from frozen to unfrozen soil-structure interaction are studied.Keywords: Adfreeze, frozen soil-structure interface, ice-poor soils, pull-out capacity, warming permafrost
Procedia PDF Downloads 1101070 Dry Binder Mixing of Field Trial Investigation Using Soil Mix Technology: Case Study on Contaminated Site Soil
Authors: Mary Allagoa, Abir Al-Tabbaa
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The study explores the use of binders and additives, such as Portland cement, pulverized fuel ash, ground granulated blast furnace slag, and MgO, to decrease the concentration and leachability of pollutants in contaminated site soils. The research investigates their effectiveness and associated risks of using the binders, with a focus on Total Heavy metals (THM) and Total Petroleum Hydrocarbon (TPH). The goal of this research is to evaluate the performance and effectiveness of binders and additives in remediating soil pollutants. The study aims to assess the suitability of the mixtures for ground improvement purposes, determine the optimal dosage, and investigate the associated risks. The research utilizes physical (unconfined compressive strength) and chemical tests (batch leachability test) to assess the efficacy of the binders and additives. A completely randomized design one-way ANOVA is used to determine the significance within mix binders of THM. The study also employs incremental lifetime cancer risk assessments (ILCR) and other indexes to evaluate the associated risks. The study finds that Ground Granulated Blast Furnace Slag (GGBS): MgO is the most effective binder for remediation, particularly when using low dosages of MgO combined with higher dosages of GGBS binders on TPH. The results indicate that binders and additives can encapsulate and immobilize pollutants, thereby reducing their leachability and toxicity. The mean unconfined compressive strength of the soil ranges from 285.0- 320.5 kPa, while THM levels are less than 10 µg/l in GGBS: MgO and CEM: PFA but below 1 µg/l in CEM I based. The ILCR ranged from 6.77E-02 - 2.65E-01 and 5.444E-01 – 3.20 E+00, with the highest values observed under extreme conditions. The hazard index (HI), Risk allowable daily dose intake (ADI), and Risk chronic daily intake (CDI) were all less than 1 for the THM. The study identifies MgO as the best additive for use in soil remediation.Keywords: risk ADI, risk CDI, ILCR, novel binders, additives binders, hazard index
Procedia PDF Downloads 8061069 A Prospective Study on the Evaluation of Statins Usage on HbA1c Control among Type 2 Diabetes Mellitus in an Outpatients Setting
Authors: Mohamed A. Hammad, Dzul Azri Mohamed Noor, Syed Azhar Syed Sulaiman, Abeer Kharshid, Nor Azizah Aziz, Tarek M. Elsayed
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Medication safety is always an issue. In 2015, the National Pharmaceutical Control Bureau released a statement requesting all statins manufacturers in Malaysia to include the risk of diabetes information in the drug information leaflet in response to United States Food and Drug Administration (U.S. FDA) report. However, the data regarding this warning label in Malaysia is limited, so there is still some uncertainty whether such risk can also be observed in the Malaysian population or not. The study aims to determine the effect of statins on HbA1c% in type 2 diabetic outpatients in endocrine clinics at Hospital Pulau Pinang between June 2015 and May 2016 in Malaysia. In a prospective cohort study, records of 400 type 2 diabetic patients (control group 104 patients not using statin and treatment group 296 patients using statin) were reviewed to identify demographic criteria and lab tests. The prevalence of glycemic control (Glycated hemoglobin, HbA1C ≤ 7% for patient < 65 years, and < 8% for patient ≥ 65 years) was estimated, according to American Diabetes Association guidelines 2015. The results were presented as descriptive statistics. From 296 patients with Type 2 diabetes using statins cohort with a mean age of 57.52 ± 12.2 years, only 81 (27.4%) cases had controlled glycemia, and 215 (72.6%) had uncontrolled glycemia, CI: 95% (6.3–11.1). While the control group 104 diabetic patients had a mean age 46.1 ± 18 years and distributed among 59 (56.7%) patients with controlled diabetes and 45 (43.3%) cases, had uncontrolled glycemia, CI: 95% (5.2–10.3). The relative risk (RR) of uncontrolled glycemia in diabetic patients used statins was 1.68, and the excessive relative risk (ERR) was 68%. The absolute risk (AR) was 29.3%, and the number needed to harm (NNH) was 4. Diabetic patients using statins have more risk of uncontrolled glycemia than the patients with Type 2 diabetes non-using statins.Keywords: diabetes mellitus, HbA1c, Malaysia, outpatients, statin, type 2, uncontrolled glycemia
Procedia PDF Downloads 2831068 Evaluation of the Cytotoxicity and Genotoxicity of Chemical Material in Filters PM2.5 of the Monitoring Stations of the Network of Air Quality in the Valle De Aburrá, Colombia
Authors: Alejandra Betancur Sánchez, Carmen Elena Zapata Sánchez, Juan Bautista López Ortiz
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Adverse effects and increased air pollution has raised concerns about regulatory policies and has fostered the development of new air quality standards; this is due to the complexity of the composition and the poorly understood reactions in the atmospheric environment. Toxic compounds act as environmental agents having various effects, from irritation to death of cells and tissues. A toxic agent is defined an adverse response in a biological system. There is a particular class that produces some kind of alteration in the genetic material or associated components, so they are recognized as genotoxic agents. Within cells, they interact directly or indirectly with DNA, causing mutations or interfere with some enzymatic repair processes or in the genesis or polymerization of proteinaceous material involved in chromosome segregation. An air pollutant may cause or contribute to increased mortality or serious illness and even pose a potential danger to human health. The aim of this study was to evaluate the effect on the viability and the genotoxic potential on the cell lines CHO-K1 and Jurkat and peripheral blood of particulate matter PM T lymphocytes 2.5 obtained from filters collected three monitoring stations network air quality Aburrá Valley. Tests, reduction of MTT, trypan blue, NRU, comet assay, sister chromatid exchange (SCE) and chromosomal aberrations allowed evidence reduction in cell viability in cell lines CHO-K1 and Jurkat and damage to the DNA from cell line CHOK1, however, no significant effects were observed in the number of SCEs and chromosomal aberrations. The results suggest that PM2.5 material has genotoxic potential and can induce cancer development, as has been suggested in other studies.Keywords: PM2.5, cell line Jurkat, cell line CHO-K1, cytotoxicity, genotoxicity
Procedia PDF Downloads 2631067 Control Algorithm Design of Single-Phase Inverter For ZnO Breakdown Characteristics Tests
Authors: Kashif Habib, Zeeshan Ayyub
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ZnO voltage dependent resistor was widely used as components of the electrical system for over-voltage protection. It has a wide application prospect in superconducting energy-removal, generator de-excitation, overvoltage protection of electrical & electronics equipment. At present, the research for the application of ZnO voltage dependent resistor stop, it uses just in the field of its nonlinear voltage current characteristic and overvoltage protection areas. There is no further study over the over-voltage breakdown characteristics, such as the combustion phenomena and the measure of the voltage/current when it breakdown, and the affect to its surrounding equipment. It is also a blind spot in its application. So, when we do the feature test of ZnO voltage dependent resistor, we need to design a reasonable test power supply, making the terminal voltage keep for sine wave, simulating the real use of PF voltage in power supply conditions. We put forward the solutions of using inverter to generate a controllable power. The paper mainly focuses on the breakdown characteristic test power supply of nonlinear ZnO voltage dependent resistor. According to the current mature switching power supply technology, we proposed power control system using the inverter as the core. The power mainly realize the sin-voltage output on the condition of three-phase PF-AC input, and 3 control modes (RMS, Peak, Average) of the current output. We choose TMS320F2812M as the control part of the hardware platform. It is used to convert the power from three-phase to a controlled single-phase sin-voltage through a rectifier, filter, and inverter. Design controller produce SPWM, to get the controlled voltage source via appropriate multi-loop control strategy, while execute data acquisition and display, system protection, start logic control, etc. The TMS320F2812M is able to complete the multi-loop control quickly and can be a good completion of the inverter output control.Keywords: ZnO, multi-loop control, SPWM, non-linear load
Procedia PDF Downloads 3241066 Perceived Criticism, Anxiety Disorders, Substance Use Disorders in Women with Borderline Personality Disorders
Authors: Ipek Sensu
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Comorbid Axis I disorders are highly common for suicidal borderline personality disorder (BPD) patients, especially substance use disorder and anxiety disorders. Since interpersonal dysfunction is one of the core symptoms in BPD, the purpose of the current study is to examine perceived criticism and anxiety disorders and also substance abuse disorders (SUD) for women with borderline personality disorder (BPD) who attempt suicide at least once in their lifetime. In the current study, it was suggested that the perceived criticism from others and being upset by criticism differ between suicidal women with BPD with comorbidity of anxiety disorders and SUD (separately) and suicidal women with BPD without anxiety disorders and without SUD (separately). The participants in this study included ninety-nine women who have already been diagnosed with borderline personality disorder and also have had at least two episodes of deliberate self-harm, in other words, suicide attempts and/or non-suicidal self-injury (NSSI) in the last five years and at least one episode in the 8-week period before joining the research study and at least one suicide attempt in the previous year. Structured Clinical Interview for DSM-IV Axis I Disorders (SCID) and Social History Interview (SHI) were conducted to determine the comorbid axis I disorders and level of perceived criticism. As a result of the independent sample t-tests, the first hypothesis was rejected, in other words, women with BPD and a comorbid anxiety disorder did not show significantly higher levels of ‘criticized by others’, compared to women with BPD alone. However, the levels of ‘upset at criticism’ were significantly different between suicidal women with BPD with or without any anxiety disorders, which is the second hypothesis. In addition, the third hypothesis was also accepted; this means, women with BPD who had any substance use dependence would show significantly higher levels of 'criticized by others' compared to women with BPD alone. Finally, the fourth hypothesis was partly accepted: that is, women with BPD with alcohol dependence had significantly higher levels of ‘how upset when they expose to criticism’, compared to those without alcohol dependence. Limitations, implications, and directions for future research are discussed.Keywords: anxiety disorders, borderline personality disorders, perceived criticism, substance use disorders
Procedia PDF Downloads 1221065 The Use of Spirulina during Aerobic Exercise on the Performance of Immune and Consumption Indicators (A Case Study: Young Men After Physical Training)
Authors: Vahab Behmanesh
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One of the topics that has always attracted the attention of sports medicine and sports science experts is the positive or negative effect of sports activities on the functioning of the body's immune system. In the present research, a course of aerobic running with spirulina consumption has been studied on the maximum oxygen consumption and the performance of some indicators of the immune system of men who have trained after one session of physical activity. In this research, 50 trained students were studied randomly in four groups, spirulina- aerobic, spirulina, placebo- aerobic, and control. In order to test the research hypotheses, one-way statistical method of variance (ANOVA) was used considering the significance level of a=0.005 and post hoc test (LSD). A blood sample was taken from the participants in the first stage test in fasting and resting state immediately after Bruce's maximal test on the treadmill until complete relaxation was reached, and their Vo2max value was determined through the aforementioned test. The subjects of the spirulina-aerobic running and placebo-aerobic running groups took three 500 mg spirulina and 500 mg placebo pills a day for six weeks and ran three times a week for 30 minutes at the threshold of aerobic stimulation. The spirulina and placebo groups also consumed spirulina and placebo tablets in the above method for six weeks. Then they did the same first stage test as the second stage test. Blood samples were taken to measure the number of CD4+, CD8+, NK, and the ratio of CD4+ to CD8+ on four occasions before and after the first and second stage tests. The analysis of the findings showed that: aerobic running and spirulina supplement alone increase Vo2max. Aerobic running and consumption of spirulina increases Vo2max more than other groups (P<0.05), +CD4 and hemoglobin of the spirulina-aerobic running group was significantly different from other groups (P=0.002), +CD4 of the groups together There was no significant difference, NK increased in all groups, the ratio of CD4+ to CD8+ between the groups had a significant difference (P=0.002), the ratio of CD4+ to CD8+ in the spirulina- aerobic group was lower than the spirulina and placebo groups. All in all, it can be concluded that the supplement of spirulina and aerobic exercise may increase Vo2max and improve safety indicators.Keywords: spirulina (Q2), hemoglobin (Q3), aerobic exercise (Q3), residual activity (Q2), CD4+ to CD8+ ratio (Q3)
Procedia PDF Downloads 1211064 Performance Analysis of a Planar Membrane Humidifier for PEM Fuel Cell
Authors: Yu-Hsuan Chang, Jian-Hao Su, Chen-Yu Chen, Wei-Mon Yan
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In this work, the experimental measurement was applied to examine the membrane type and flow field design on the performance of a planar membrane humidifier. The performance indexes were used to evaluate the planar membrane humidifier. The performance indexes of the membrane humidifier include the dew point approach temperature (DPAT), water recovery ratio (WRR), water flux (J) and pressure loss (P). The experiments contain mainly three parts. In the first part, a single membrane humidifier was tested using different flow field under different dry-inlet temperatures. The measured results show that the dew point approach temperature decreases with increasing the depth of flow channel at the same width of flow channel. However, the WRR and J reduce with an increase in the dry air-inlet temperature. The pressure loss tests indicate that pressure loss decreases with increasing the hydraulic diameter of flow channel, resulting from an increase in Darcy friction. Owing to the comparison of humidifier performances and pressure losses, the flow channel of width W=1 and height H=1.5 was selected as the channel design of the multi-membrane humidifier in the second part of experiment. In the second part, the multi-membrane humidifier was used to evaluate the humidification performance under different relative humidity and flow rates. The measurement results indicate that the humidifier at both lower temperature and relative humidity of inlet dry air have higher DPAT but lower J and WRR. In addition, the counter flow approach has better mass and heat transfer performance than the parallel flow approach. Moreover, the effects of dry air temperature, relative humidity and humidification approach are not significant to the pressure loss in the planar membrane humidifier. For the third part, different membranes were tested in this work in order to find out which kind membrane is appropriate for humidifier.Keywords: water management, planar membrane humidifier, heat and mass transfer, pressure loss, PEM fuel cell
Procedia PDF Downloads 2051063 The Relationship of Fast Food Consumption Preference with Macro and Micro Nutrient Adequacy Students of SMP Negeri 5 Padang
Authors: Widari
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This study aims to determine the relationship of fast food consumption preferences with macro and micro nutrient adequacy students of SMP Negeri 5 Padang. This study used a cross sectional study conducted on 100 students of SMP Negeri 5 Padang. The variables studied were fast food preferences, nutrition adequacy macronutrients (carbohydrate, protein, fat, fiber) and micro nutrients (sodium, calcium, iron). Confounding factor in this study was the physical activity level because it was considered quite affecting food consumption of students. Data collected by using a questionnaire food recall as many as 2 x 24 hours to see the history of the respondents eat at school day and on holidays. Then, data processed using software Nutrisurvey and Microsoft Excel 2010. The analysis was performed on samples that have low and medium category on physical activity. The physical activity was not analyzed with another variable to see the strength of the relationship between independent and dependent variables. So that, do restrictions on physical activity variables in an attempt to get rid of confounding in design. Univariate and bivariate analyzes performed using SPSS 16.0 for Windows with Kolmogrov-Smirnov statistical tests, confidence level = 95% (α = 0,05). Results of univariate analysis showed that more than 70% of respondents liked fast food. On average, respondents were malnourished macro; malnourished fiber (100%), carbohydrates (72%), and protein (56%), whereas for fat, excess intake of the respondents (41%). Furthermor, many respondents who have micronutrient deficiencies; 98% for sodium, 96% for iron, and 91% for calcium. The results of the bivariate analysis showed no significant association between fast food consumption preferences with macro and micro nutrient adequacy (p > 0,05). This happens because in the fact not all students who have a preference for fast food actually eat them. To study better in the future, it is expected sampling really like and eat fast food in order to obtain better analysis results.Keywords: fast food, nutritional adequacy, preferences, students
Procedia PDF Downloads 3711062 Antibiotic Resistance and Susceptibility of Bacteria Strains Isolated from Sheep Milk
Authors: Fatima Bouazza, Rachida Hassikou, Lamiae Amallah, Jihane Ennadir, Khadija Khedid
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This study evaluated the in vitro resistance and susceptibility of Enterobacteriaceae (Escherichia coli and Klebsiella oxytoca strains) and Staphylococci strains, isolated from sheep’s milk, against antibiotics and essential oils from Thymus satureioides and Mentha pulegium. Antibiotic resistance tests were done using disc diffusion while essential oils were extracted by steam distillation, and yields were calculated relative to plant dry matter. Gas chromatography-mass Spectrometry (GC-MS) was used to analyze each oil's chemical composition. The AMC, CTX, FOX, NA, CN, CIP, and OFX were very effective against the E. coli strains tested. Half of the strains were resistant to AMC, 60% to TIC, and 80% to TE. The K. oxytoca was resistant against AMC, FOX, and TIC (100%). Antibiotic-resistant testing on Staphylococci strains indicated Staphylococcus capitis and Staphylococcus chromogenes as the most sensitive. Staphylococcus aureus, Staphylococcus xylosus, and Staphylococcus cohnii ureal exhibited less resistance to OX, TE, PT, E, and P. The M. pulegium resulted in a higher yield of essential oil of 3.2% oil compared to T. satureioides with only 1.85% yield. Staphylococcus aureus, Staphylococcus xylosus, and Staphylococcus cohnii ureal had lower OX, TE, PT, E, and P resistance. M. pulegium yielded 3.2% essential oil compared to 1.85% for T. satureioides. The monoterpene oxygenated derivatives, monoterpene hydrocarbons, and phenols are found in essential oil extracts. T. satureioides essential oil had high antibacterial activity even at low concentrations (0.2; 0.55 g/mL). The Minimal Bactericidal Concentration (MBC) values indicate that the essential oils from the plants analyzed had bactericidal effects on all strains tested and are similar to the Minimal Inhibitory Concentration (MIC) values. The high antibacterial properties of these medicinal plants, against bacteria isolated from sheep’s milk, provide an opportunity to use these medicinal plants in the breeding sector as additives and preservatives in the dairy industry.Keywords: antibiotic resistance, medicinal plants, essential oils, enterobacteriaceae, staphylococci, sheep milk
Procedia PDF Downloads 1601061 Application of Pyridine-based Water-soluble Corrosion Inhibitor in Offshore Sweet Oil Pipeline
Authors: M. S. Yalfani, J. Kohzadi, P. Ghadimi, S. Sobhani, M. Ghadimi
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The use of oil and water-soluble corrosion inhibitors has been established in Iranian oil and gas production systems for a long time. Imidazoline and its derivatives are being extensively used which are known as conventional corrosion inhibitors. This type of product has shown significant performance and low side effects, so that could monopolize the market of inhibitors in this region. However, the price growth of imidazolines, as well as the development of new lower-cost components with similar or even higher performance than imidazoline, have influenced the exclusive market of imidazoline-based products. During the latest years, pyridine and its derivatives have challenged imidazoline due to their remarkable anticorrosive properties and lower prices as well. Recently, we presented a formulated water-soluble inhibitor based on pyridine - an alkyl pyridine quaternary salt (APQS) - which could successfully pass all lab tests and eventually succeeded in being applied in an offshore sweet oil pipeline. The product was able to achieve high corrosion protection (> 90 %) with the LPR technique at low dosages of 15-25 ppm under severe corrosion conditions. Moreover, the lab test results showed that the APQS molecule is able to form a strong and persistent bond with the metal surface. The product was later nominated to be evaluated through a field trial in an offshore sweet oil pipeline where PH2S < 0.05 psi and CO2 is 6.4 mol%. The three-month trial - extended to six months- resulted in remarkable internal protection obtained by continuous injection of 10 ppm inhibitor, which was as low as 1 mpy measured by both weight loss corrosion coupons and online ER probes. In addition, no side effects, such as tight emulsion and stable foaming, were observed. The residual of the corrosion inhibitor was measured at the end of the pipeline to ensure the full coverage of the inhibitor throughout the pipeline. Eventually, these promising results were able to convince the end user to consider pyridine-based inhibitors as a reliable alternative to imidazoline.Keywords: corrosion inhibitor, pyridine, sweet oil, pipeline, offshore
Procedia PDF Downloads 51060 Preparation of Novel Silicone/Graphene-based Nanostructured Surfaces as Fouling Release Coatings
Authors: Mohamed S. Selim, Nesreen A. Fatthallah, Shimaa A. Higazy, Zhifeng Hao, Ping Jing Mo
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As marine fouling-release (FR) surfaces, two new superhydrophobic nanocomposite series of polydimethylsiloxane (PDMS) loaded with reduced graphene oxide (RGO) and graphene oxide/boehmite nanorods (GO-γ-AlOOH) nanofillers were created. The self-cleaning and antifouling capabilities were modified by controlling the nanofillers' shapes and distribution in the silicone matrix. With an average diameter of 10-20 nm and a length of 200 nm, γ-AlOOH nanorods showed a single crystallinity. RGO was made using a hydrothermal process, whereas GO-γ-AlOOH nanocomposites were made using a chemical deposition method for use as fouling-release coating materials. These nanofillers were disseminated in the silicone matrix using the solution casting method to explore the synergetic effects of graphene-based materials on the surface, mechanical, and FR characteristics. Water contact angle (WCA), scanning electron, and atomic force microscopes were used to investigate the surface's hydrophobicity and antifouling capabilities (SEM and AFM). The roughness, superhydrophobicity, and surface mechanical characteristics of coatings all increased the homogeneity of the nanocomposite dispersion. To examine the antifouling effects of the coating systems, laboratory tests were conducted for 30 days using specified bacteria.PDMS/GO-γ-AlOOH nanorod composite demonstrated superior antibacterial efficacy against several bacterial strains than PDMS/RGO nanocomposite. The high surface area and stabilizing effects of the GO-γ-AlOOH hybrid nanofillers are to blame for this. The biodegradability percentage of the PDMS/GO-γ-AlOOH nanorod composite (3 wt.%) was the lowest (1.6%), while the microbial endurability percentages for gram-positive, gram-negative, and fungi were 86.42%, 97.94%, and 85.97%, respectively. The homogeneity of the GO-γ-AlOOH (3 wt.%) dispersion, which had a WCA of 151° and a rough surface, was the most profound superhydrophobic antifouling nanostructured coating.Keywords: superhydrophobic nanocomposite, fouling release, nanofillers, surface coating
Procedia PDF Downloads 2321059 Testing for Endogeneity of Foreign Direct Investment: Implications for Economic Policy
Authors: Liwiusz Wojciechowski
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Research background: The current knowledge does not give a clear answer to the question of the impact of FDI on productivity. Results of the empirical studies are still inconclusive, no matter how extensive and diverse in terms of research approaches or groups of countries analyzed they are. It should also take into account the possibility that FDI and productivity are linked and that there is a bidirectional relationship between them. This issue is particularly important because on one hand FDI can contribute to changes in productivity in the host country, but on the other hand its level and dynamics may imply that FDI should be undertaken in a given country. As already mentioned, a two-way relationship between the presence of foreign capital and productivity in the host country should be assumed, taking into consideration the endogenous nature of FDI. Purpose of the article: The overall objective of this study is to determine the causality between foreign direct investment and total factor productivity in host county in terms of different relative absorptive capacity across countries. In the classic sense causality among variables is not always obvious and requires for testing, which would facilitate proper specification of FDI models. The aim of this article is to study endogeneity of selected macroeconomic variables commonly being used in FDI models in case of Visegrad countries: main recipients of FDI in CEE. The findings may be helpful in determining the structure of the actual relationship between variables, in appropriate models estimation and in forecasting as well as economic policymaking. Methodology/methods: Panel and time-series data techniques including GMM estimator, VEC models and causality tests were utilized in this study. Findings & Value added: The obtained results allow to confirm the hypothesis states the bi-directional causality between FDI and total factor productivity. Although results differ from among countries and data level of aggregation implications may be useful for policymakers in case of providing foreign capital attracting policy.Keywords: endogeneity, foreign direct investment, multi-equation models, total factor productivity
Procedia PDF Downloads 1961058 Influence of Thermal Damage on the Mechanical Strength of Trimmed CFRP
Authors: Guillaume Mullier, Jean François Chatelain
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Carbon Fiber Reinforced Plastics (CFRPs) are widely used for advanced applications, in particular in aerospace, automotive and wind energy industries. Once cured to near net shape, CFRP parts need several finishing operations such as trimming, milling or drilling in order to accommodate fastening hardware and meeting the final dimensions. The present research aims to study the effect of the cutting temperature in trimming on the mechanical strength of high performance CFRP laminates used for aeronautics applications. The cutting temperature is of great importance when dealing with trimming of CFRP. Temperatures higher than the glass-transition temperature (Tg) of the resin matrix are highly undesirable: they cause degradation of the matrix in the trimmed edges area, which can severely affect the mechanical performance of the entire component. In this study, a 9.50 mm diameter CVD diamond coated carbide tool with six flutes was used to trim 24-plies CFRP laminates. A 300 m/min cutting speed and 1140 mm/min feed rate were used in the experiments. The tool was heated prior to trimming using a blowtorch, for temperatures ranging from 20°C to 300°C. The temperature at the cutting edge was measured using embedded K-Type thermocouples. Samples trimmed for different cutting temperatures, below and above Tg, were mechanically tested using three-points bending short-beam loading configurations. New cutting tools as well as worn cutting tools were utilized for the experiments. The experiments with the new tools could not prove any correlation between the length of cut, the cutting temperature and the mechanical performance. Thus mechanical strength was constant, regardless of the cutting temperature. However, for worn tools, producing a cutting temperature rising up to 450°C, thermal damage of the resin was observed. The mechanical tests showed a reduced mean resistance in short beam configuration, while the resistance in three point bending decreases with increase of the cutting temperature.Keywords: composites, trimming, thermal damage, surface quality
Procedia PDF Downloads 3201057 The Effect of Satisfaction with the Internet on Online Shopping Attitude With TAM Approach Controlled By Gender
Authors: Velly Anatasia
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In the last few decades extensive research has been conducted into information technology (IT) adoption, testing a series of factors considered to be essential for improved diffusion. Some studies analyze IT characteristics such as usefulness, ease of use and/or security, others focus on the emotions and experiences of users and a third group attempts to determine the importance of socioeconomic user characteristics such as gender, educational level and income. The situation is similar regarding e-commerce, where the majority of studies have taken for granted the importance of including these variables when studying e-commerce adoption, as these were believed to explain or forecast who buys or who will buy on the internet. Nowadays, the internet has become a marketplace suitable for all ages and incomes and both genders and thus the prejudices linked to the advisability of selling certain products should be revised. The objective of this study is to test whether the socioeconomic characteristics of experienced e-shoppers such as gender rally moderate the effect of their perceptions of online shopping behavior. Current development of the online environment and the experience acquired by individuals from previous e-purchases can attenuate or even nullify the effect of these characteristics. The individuals analyzed are experienced e-shoppers i.e. individuals who often make purchases on the internet. The Technology Acceptance Model (TAM) was broadened to include previous use of the internet and perceived self-efficacy. The perceptions and behavior of e-shoppers are based on their own experiences. The information obtained will be tested using questionnaires which were distributed and self-administered to respondent accustomed using internet. The causal model is estimated using structural equation modeling techniques (SEM), followed by tests of the moderating effect of socioeconomic variables on perceptions and online shopping behavior. The expected findings of this study indicated that gender moderate neither the influence of previous use of the internet nor the perceptions of e-commerce. In short, they do not condition the behavior of the experienced e-shopper.Keywords: Internet shopping, age groups, gender, income, electronic commerce
Procedia PDF Downloads 3351056 The Effects of Lipid Emulsion, Magnesium Sulphate and Metoprolol in Amitryptiline-Induced Cardiovascular Toxicity in Rats
Authors: Saylav Ejder Bora, Arife Erdogan, Mumin Alper Erdogan, Oytun Erbas, Ismet Parlak
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Objective: The aim of this study was to evaluate histological, electrical and biochemical effects of metoprolol, lipid emulsion and magnesium sulphate as an alternative method to be used in preventing long QT emergence, that is among the lethal consequences of amitryptiline toxicity. Methods: Thirty Sprague- Dawley male rats were included. Rats were randomly separated into 5 groups. First group was administered saline only while the rest had received amitryptiline 100 mg/kg + saline, 5 mg/kg metoprolol, 20 ml/kg lipid emulsion and 75 mg/kg magnesium sulphate (MgSO4) intraperitoneally. ECG at DI lead, biochemical tests following euthanasia were performed in all groups after 1 hour of administration. Cardiac tissues were removed, sections were prepared and examined. Results: QTc values were significantly shorter in the rest when compared to amitryptiline+ saline group. While lipid emulsion did not affect proBNP and troponin values biochemically as compared to that of the control group, histologically, it was with reduced caspase 3 expression. Though statistically insignificant in the context of biochemical changes, pro-BNP and urea levels were lower in the metoprolol group when compared to controls. Similarly, metoprolol had no statistically significant effect on histological caspase 3 expression in the group that was treated with amitryptiline+metoprolol. On the other hand, there was a statistically significant decrease in Troponin, pro-BNP and urea levels as well as significant decline in histological caspase 3 expression within the MgSO4 group when compared to controls. Conclusion: As still a frequent cause of mortality in emergency units, administration of MgSO4, lipid emulsion and metoprolol might be beneficial in alternative treatment of cardiovascular toxicity caused by tricyclic antidepressant overdose, whether intake would be intentional or accidental.Keywords: amitryptiline, cardiovascular toxicity, long QT, Rat Model
Procedia PDF Downloads 1751055 Security of Database Using Chaotic Systems
Authors: Eman W. Boghdady, A. R. Shehata, M. A. Azem
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Database (DB) security demands permitting authorized users and prohibiting non-authorized users and intruders actions on the DB and the objects inside it. Organizations that are running successfully demand the confidentiality of their DBs. They do not allow the unauthorized access to their data/information. They also demand the assurance that their data is protected against any malicious or accidental modification. DB protection and confidentiality are the security concerns. There are four types of controls to obtain the DB protection, those include: access control, information flow control, inference control, and cryptographic. The cryptographic control is considered as the backbone for DB security, it secures the DB by encryption during storage and communications. Current cryptographic techniques are classified into two types: traditional classical cryptography using standard algorithms (DES, AES, IDEA, etc.) and chaos cryptography using continuous (Chau, Rossler, Lorenz, etc.) or discreet (Logistics, Henon, etc.) algorithms. The important characteristics of chaos are its extreme sensitivity to initial conditions of the system. In this paper, DB-security systems based on chaotic algorithms are described. The Pseudo Random Numbers Generators (PRNGs) from the different chaotic algorithms are implemented using Matlab and their statistical properties are evaluated using NIST and other statistical test-suits. Then, these algorithms are used to secure conventional DB (plaintext), where the statistical properties of the ciphertext are also tested. To increase the complexity of the PRNGs and to let pass all the NIST statistical tests, we propose two hybrid PRNGs: one based on two chaotic Logistic maps and another based on two chaotic Henon maps, where each chaotic algorithm is running side-by-side and starting from random independent initial conditions and parameters (encryption keys). The resulted hybrid PRNGs passed the NIST statistical test suit.Keywords: algorithms and data structure, DB security, encryption, chaotic algorithms, Matlab, NIST
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