Search results for: thermoelastic effect
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 14746

Search results for: thermoelastic effect

9256 Plantar Neuro-Receptor Activation in Total Knee Arthroplasty Patients: Impact on Clinical Function, Pain, and Stiffness - A Randomized Controlled Trial

Authors: Woolfrey K., Woolfrey M., Bolton C. L., Warchuk D.

Abstract:

Objectives: Osteoarthritis is the most common joint disease of adults worldwide. Despite total knee arthroplasty (TKA) demonstrating high levels of success, 20% of patients report dissatisfaction with their result. VOXX Wellness Stasis Socks are embedded with a proprietary pattern of neuro-receptor activation points that have been proven to activate a precise neuro-response, according to the pattern theory of haptic perception, which stimulates improvements in pain and function. The use of this technology in TKA patients may prove beneficial as an adjunct to recovery as many patients suffer from deficits to their proprioceptive system caused by ligamentous damage and alterations to mechanoreceptors during the procedure. We hypothesized that VOXX Wellness Stasis Socks are a safe, cost-effective, and easily scalable strategy to support TKA patients through their recovery. Design: Double-blinded, placebo-controlled randomized trial. Participants: Patients scheduled to receive TKA were considered eligible for inclusion in the trial. Interventions: Intervention group (I): VOXX Wellness Stasis socks containing receptor point-activation technology. Control group (C): VOXX Wellness Stasis socks without receptor point-activation technology. Sock use during the waking hours x 6 weeks. Main Outcome Measures: Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) questionnaire completed at baseline, 2 weeks, and 6 weeks to assess pain, stiffness, and physical function. Results: Data analysis using SPSS software. P-values, effect sizes, and confidence intervals are reported to assess clinical relevance of the finding. Physical status classifications were compared using t-test. Within-subject and between-subject differences in the mean WOMAC were analyzed by ANOVA. Effect size was analyzed using Cramer’s V. Consistent improvement in WOMAC scores for pain and stiffness at 2 weeks post op in the I over the C group. The womac scores assessing physical function showed a consistent improvement at both 2 and 6 weeks post op in the I group compared to C group. Conclusions: VOXX proved to be a low cost, safe intervention in TKA to help patients improve with regard to pain, stiffness, and physical function. Disclosures: None

Keywords: osteoarthritis, RCT, pain management, total knee arthroplasty

Procedia PDF Downloads 531
9255 Ultra-Low Loss Dielectric Properties of (Mg1-xNix)2(Ti0.95Sn0.05)O4 Microwave Ceramics

Authors: Bing-Jing Li, Sih-Yin Wang, Tse-Chun Yeh, Yuan-Bin Chen

Abstract:

Microwave dielectric ceramic materials of (Mg1-xNix)2(Ti0.95Sn0.05)O4 for x = 0.01, 0.03, 0.05, 0.07 and 0.09 were prepared and sintered at 1250–1400ºC. The microstructure and microwave dielectric properties of the ceramic materials were examined and measured. The observations shows that the content of Ni2+ ions has little effect on the crystal structure, dielectric constant, temperature coefficient of resonant frequency (τf) and sintering temperatures of the ceramics. However, the quality values (Q×f) are greatly improved due to the addition of Ni2+ ions. The present study showed that the ceramic material prepared for x = 0.05 and sintered at 1325ºC had the best Q×f value of 392,000 GHz, about 23% improvement compared with that of Mg2(Ti0.95Sn0.05)O4.

Keywords: (Mg1-xNix)2(Ti0.95Sn0.05)O4, microwave dielectric ceramics, high quality factor, high frequency wireless communication

Procedia PDF Downloads 484
9254 Corporate Social Responsibility Participation on Organizational Citizenship Behavior in Different Job Characteristic Profiles

Authors: Min Woo Lee, Kyoung Seok Kim

Abstract:

We made an effort to resolve a research question, which is about the relationship between employees’ corporate social responsibility (CSR) participation and their organizational citizenship behavior (OCB), and an effect of profiles of job characteristics. To test the question, we divided sample into two groups that have the profiles of each job characteristic. One group had high level on the five dimensions of job characteristic (D group), whereas another group had low level on the dimensions (R group). As a result, regression analyses showed that the relationship between CSR participation and OCB is positive in the D group, but the relationship is not significant in the R group. The results raise a question to the argument of recent studies showing that there is positive relationship between the CSR and the OCB. Implications and limitations are demonstrated in the conclusion.

Keywords: CSR, OCB, job characteristics, cluster analysis

Procedia PDF Downloads 323
9253 Analytical Solution for Stellar Distance Based on Photon Dominated Cosmic Expansion Model

Authors: Xiaoyun Li, Suoang Longzhou

Abstract:

This paper derives the analytical solution of stellar distance according to its redshift based on the photon-dominated universe expansion model. Firstly, it calculates stellar separation speed and the farthest distance of observable stars via simulation. Then the analytical solution of stellar distance according to its redshift is derived. It shows that when the redshift is large, the stellar distance (and its separation speed) is not proportional to its redshift due to the relativity effect. It also reveals the relationship between stellar age and its redshift. The correctness of the analytical solution is verified by the latest astronomic observations of Ia supernovas in 2020.

Keywords: redshift, cosmic expansion model, analytical solution, stellar distance

Procedia PDF Downloads 158
9252 Antagonistic Potential of Epiphytic Bacteria Isolated in Kazakhstan against Erwinia amylovora, the Causal Agent of Fire Blight

Authors: Assel E. Molzhigitova, Amankeldi K. Sadanov, Elvira T. Ismailova, Kulyash A. Iskandarova, Olga N. Shemshura, Ainur I. Seitbattalova

Abstract:

Fire blight is a very harmful for commercial apple and pear production quarantine bacterial disease. To date, several different methods have been proposed for disease control, including the use of copperbased preparations and antibiotics, which are not always reliable or effective. The use of bacteria as biocontrol agents is one of the most promising and eco-friendly alternative methods. Bacteria with protective activity against the causal agent of fire blight are often present among the epiphytic microorganisms of the phyllosphere of host plants. Therefore, the main objective of our study was screening of local epiphytic bacteria as possible antagonists against Erwinia amylovora, the causal agent of fire blight. Samples of infected organs of apple and pear trees (shoots, leaves, fruits) were collected from the industrial horticulture areas in various agro-ecological zones of Kazakhstan. Epiphytic microorganisms were isolated by standard and modified methods on specific nutrient media. The primary screening of selected microorganisms under laboratory conditions to determine the ability to suppress the growth of Erwinia amylovora was performed by agar-diffusion-test. Among 142 bacteria isolated from the fire blight host plants, 5 isolates, belonging to the genera Bacillus, Lactobacillus, Pseudomonas, Paenibacillus and Pantoea showed higher antagonistic activity against the pathogen. The diameters of inhibition zone have been depended on the species and ranged from 10 mm to 48 mm. The maximum diameter of inhibition zone (48 mm) was exhibited by B. amyloliquefaciens. Less inhibitory effect was showed by Pantoea agglomerans PA1 (19 mm). The study of inhibitory effect of Lactobacillus species against E. amylovora showed that among 7 isolates tested only one (Lactobacillus plantarum 17M) demonstrated inhibitory zone (30 mm). In summary, this study was devoted to detect the beneficial epiphytic bacteria from plants organs of pear and apple trees due to fire blight control in Kazakhstan. Results obtained from the in vitro experiments showed that the most efficient bacterial isolates are Lactobacillus plantarum 17M, Bacillus amyloliquefaciens MB40, and Pantoea agglomerans PA1. These antagonists are suitable for development as biocontrol agents for fire blight control. Their efficacies will be evaluated additionally, in biological tests under in vitro and field conditions during our further study.

Keywords: antagonists, epiphytic bacteria, Erwinia amylovora, fire blight

Procedia PDF Downloads 166
9251 Effects of the Ambient Temperature and the Defect Density on the Performance the Solar Cell (HIT)

Authors: Bouzaki Mohammed Moustafa, Benyoucef Boumediene, Benouaz Tayeb, Benhamou Amina

Abstract:

The ambient temperature and the defects density in the Hetero-junction with Intrinsic Thin layers solar cells (HIT) strongly influence their performances. In first part, we presented the bands diagram on the front/back simulated solar cell based on a-Si: H / c-Si (p)/a-Si:h. In another part, we modeled the following layers structure: ZnO/a-Si:H(n)/a-Si:H(i)/c-Si(p)/a-Si:H(p)/Ag where we studied the effect of the ambient temperature and the defects density in the gap of the crystalline silicon layer on the performance of the heterojunction solar cell with intrinsic layer (HIT).

Keywords: heterojunction solar cell, solar cell performance, bands diagram, ambient temperature, defect density

Procedia PDF Downloads 505
9250 Anchorage Effect on Axial Strength of Fiber Reinforced Polymers Confined Rectangular Columns

Authors: Yavuz Yardim

Abstract:

FRP systems have been largely used to improve the performance of structural members, due to their high strength to weight ratio and corrosion resistance. Application of this strengthening procedure in circular columns has resulted quite beneficial in increasing their seismic and axial capacity. Whereas in the rectangular ones, strength enhancement was considerably less due to stress concentration in the corner. In this work three anchorage configurations are tested for their efficiency in increasing the uniformity of confinement pressure in the CFRP strengthened non-circular sections. There is a slight increase in the axial strength of specimens as a general trend. More specifically fan anchorage reached an increase of 17.5% compared to the unanchored specimens. The study shows that uniformity of confining pressure has increased by adding anchorage.

Keywords: rectangular columns, FRP, confinement, anchorage

Procedia PDF Downloads 357
9249 Effect of Lime Stabilization on E. coli Destruction and Heavy Metal Bioavailability in Sewage Sludge for Agricultural Utilization

Authors: G. Petruzzelli, F. Pedron, M. Grifoni, A. Pera, I. Rosellini, B. Pezzarossa

Abstract:

The addition of lime as Ca(OH)2 to sewage sludge to destroy pathogens (Escherichia coli), was evaluated also in relation to heavy metal bioavailability. The obtained results show that the use of calcium hydroxide at the dose of 3% effectively destroyed pathogens ensuring the stability at high pH values over long period and the duration of the sewage sludge stabilization. In general, lime addition decreased the total extractability of heavy metals indicating a reduced bioavailability of these elements. This is particularly important for a safe utilization in agricultural soils to reduce the possible transfer of heavy metals to the food chain.

Keywords: biological sludge, Ca(OH)2, copper, pathogens, sanitation, zinc

Procedia PDF Downloads 426
9248 By-Line Analysis of Determinants Insurance Premiums : Evidence from Tunisian Market

Authors: Nadia Sghaier

Abstract:

In this paper, we aim to identify the determinants of the life and non-life insurance premiums of different lines for the case of the Tunisian insurance market over a recent period from 1997 to 2019. The empirical analysis is conducted using the linear cointegration techniques in the panel data framework, which allow both long and short-run relationships. The obtained results show evidence of long-run relationship between premiums, losses, and financial variables (stock market indices and interest rate). Furthermore, we find that the short-run effect of explanatory variables differs across lines. This finding has important implications for insurance tarification and regulation.

Keywords: insurance premiums, lines, Tunisian insurance market, cointegration approach in panel data

Procedia PDF Downloads 196
9247 Determinants of Budget Performance in an Oil-Based Economy

Authors: Adeola Adenikinju, Olusanya E. Olubusoye, Lateef O. Akinpelu, Dilinna L. Nwobi

Abstract:

Since the enactment of the Fiscal Responsibility Act (2007), the Federal Government of Nigeria (FGN) has made public its fiscal budget and the subsequent implementation report. A critical review of these documents shows significant variations in the five macroeconomic variables which are inputs in each Presidential budget; oil Production target (mbpd), oil price ($), Foreign exchange rate(N/$), and Gross Domestic Product growth rate (%) and inflation rate (%). This results in underperformance of the Federal budget expected output in terms of non-oil and oil revenue aggregates. This paper evaluates first the existing variance between budgeted and actuals, then the relationship and causality between the determinants of Federal fiscal budget assumptions, and finally the determinants of FGN’s Gross Oil Revenue. The paper employed the use of descriptive statistics, the Autoregressive distributed lag (ARDL) model, and a Profit oil probabilistic model to achieve these objectives. This model permits for both the static and dynamic effect(s) of the independent variable(s) on the dependent variable, unlike a static model that accounts for static or fixed effect(s) only. It offers a technique for checking the existence of a long-run relationship between variables, unlike other tests of cointegration, such as the Engle-Granger and Johansen tests, which consider only non-stationary series that are integrated of the same order. Finally, even with small sample size, the ARDL model is known to generate a valid result, for it is the dependent variable and is the explanatory variable. The results showed that there is a long-run relationship between oil revenue as a proxy for budget performance and its determinants; oil price, produced oil quantity, and foreign exchange rate. There is a short-run relationship between oil revenue and its determinants; oil price, produced oil quantity, and foreign exchange rate. There is a long-run relationship between non-oil revenue and its determinants; inflation rate, GDP growth rate, and foreign exchange rate. The grangers’ causality test results show that there is a mono-directional causality between oil revenue and its determinants. The Federal budget assumptions only explain 68% of oil revenue and 62% of non-oil revenue. There is a mono-directional causality between non-oil revenue and its determinants. The Profit oil Model describes production sharing contracts, joint ventures, and modified carrying arrangements as the greatest contributors to FGN’s gross oil revenue. This provides empirical justification for the selected macroeconomic variables used in the Federal budget design and performance evaluation. The research recommends other variables, debt and money supply, be included in the Federal budget design to explain the Federal budget revenue performance further.

Keywords: ARDL, budget performance, oil price, oil quantity, oil revenue

Procedia PDF Downloads 171
9246 The Effect of Coronavirus on Social Adjustment and Depression of Arak University Students

Authors: Mansour Abdi

Abstract:

The aim of this study has been the investigation of coronavirus influence/impact on social adjustment and depression of Arak University students. The samples of study are 100 available female students at Arak University. They were assessed by the Bell Social Adjustment Questionnaire and Beck Depression. They were asked to answer two situations before the corona outbreak and the present. The result of evaluating/assessing the difference between social adjustment before and after coronavirus was not significant but, the averages indicate a decrease in the adjustment of students before and after the coronavirus. Meanwhile, there was no significant difference in depression findings but, in the present, the average amount of depression indicated an increase than its amount before the corona.

Keywords: depression, social adjustment student, coronavirus, student

Procedia PDF Downloads 118
9245 Multiple Fault Diagnosis in Digital Circuits using Critical Path Tracing and Enhanced Deduction Algorithm

Authors: Mohamed Mahmoud

Abstract:

This paper has developed an effect-cause analysis technique for fault diagnosis in digital circuits. The main algorithm of our technique is based on the Enhanced Deduction Algorithm, which processes the real response of the CUT to the applied test T to deduce the values of the internal lines. An experimental version of the algorithm has been implemented in C++. The code takes about 7592 lines. The internal values are determined based on the logic values under the permanent stuck-fault model. Using a backtracking strategy guarantees that the actual values are covered by at least one solution, or no solution is found.

Keywords: enhanced deduction algorithm, backtracking strategy, automatic test equipment, verfication

Procedia PDF Downloads 118
9244 Effect of MPPT and THD in Grid-Connected Photovoltaic System

Authors: Sajjad Yahaghifar

Abstract:

From the end of the last century, the importance and use of renewable energy sources have gained prominence, due not only by the fossil fuels dependence reduction, but mainly by environmental reasons related to climate change and the effects to the humanity. Consequently, solar energy has been arousing interest in several countries for being a technology considered clean, with reduced environmental impact. The output power of photo voltaic (PV) arrays is always changing with weather conditions,i.e., solar irradiation and atmospheric temperature. Therefore, maximum power point tracking (MPPT) control to extract maximum power from the PV arrays at real time becomes indispensable in PV generation system. This paper Study MPPT and total harmonic distortion (THD) in the city of Tabriz, Iran with the grid-connected PV system as distributed generation.

Keywords: MPPT, THD, grid-connected, PV system

Procedia PDF Downloads 395
9243 Efficient Model Selection in Linear and Non-Linear Quantile Regression by Cross-Validation

Authors: Yoonsuh Jung, Steven N. MacEachern

Abstract:

Check loss function is used to define quantile regression. In the prospect of cross validation, it is also employed as a validation function when underlying truth is unknown. However, our empirical study indicates that the validation with check loss often leads to choosing an over estimated fits. In this work, we suggest a modified or L2-adjusted check loss which rounds the sharp corner in the middle of check loss. It has a large effect of guarding against over fitted model in some extent. Through various simulation settings of linear and non-linear regressions, the improvement of check loss by L2 adjustment is empirically examined. This adjustment is devised to shrink to zero as sample size grows.

Keywords: cross-validation, model selection, quantile regression, tuning parameter selection

Procedia PDF Downloads 435
9242 Growth of Struvite Crystals in Synthetic Urine Using Magnesium Nitrate

Authors: Reneiloe Seodigeng, John Kabuba, Hilary Rutto, Tumisang Seodigeng

Abstract:

Urine diversion toilets have become popular as a means of solving the challenges in sanitation. As a result, the source-separated urine must be adequately treated so that it can be disposed of safely and valuable struvite can be extracted for use as fertilizer. In this study, synthetic urine was prepared, and struvite crystallisation experiments carried out using magnesium nitrate. The effect of residence time on crystal growth was studied. At residence time of 10, 30 and 60 minutes, mean particle sizes were 17, 34 and 53 µm showing that with higher residence times, larger crystal sizes can be achieved. SEM analysis of the crystal showed that the resultant crystals had the typical morphology of struvite crystals.

Keywords: struvite, magnesium nitrate, crystallisation, urine treatment

Procedia PDF Downloads 158
9241 Attention States in the Sustained Attention to Response Task: Effects of Trial Duration, Mind-Wandering and Focus

Authors: Aisling Davies, Ciara Greene

Abstract:

Over the past decade the phenomenon of mind-wandering in cognitive tasks has attracted widespread scientific attention. Research indicates that mind-wandering occurrences can be detected through behavioural responses in the Sustained Attention to Response Task (SART) and several studies have attributed a specific pattern of responding around an error in this task to an observable effect of a mind-wandering state. SART behavioural responses are also widely accepted as indices of sustained attention and of general attention lapses. However, evidence suggests that these same patterns of responding may be attributable to other factors associated with more focused states and that it may also be possible to distinguish the two states within the same task. To use behavioural responses in the SART to study mind-wandering, it is essential to establish both the SART parameters that would increase the likelihood of errors due to mind-wandering, and exactly what type of responses are indicative of mind-wandering, neither of which have yet been determined. The aims of this study were to compare different versions of the SART to establish which task would induce the most mind-wandering episodes and to determine whether mind-wandering related errors can be distinguished from errors during periods of focus, by behavioural responses in the SART. To achieve these objectives, 25 Participants completed four modified versions of the SART that differed from the classic paradigm in several ways so to capture more instances of mind-wandering. The duration that trials were presented for was increased proportionately across each of the four versions of the task; Standard, Medium Slow, Slow, and Very Slow and participants intermittently responded to thought probes assessing their level of focus and degree of mind-wandering throughout. Error rates, reaction times and variability in reaction times decreased in proportion to the decrease in trial duration rate and the proportion of mind-wandering related errors increased, until the Very Slow condition where the extra decrease in duration no longer had an effect. Distinct reaction time patterns around an error, dependent on level of focus (high/low) and level of mind-wandering (high/low) were also observed indicating four separate attention states occurring within the SART. This study establishes the optimal duration of trial presentation for inducing mind-wandering in the SART, provides evidence supporting the idea that different attention states can be observed within the SART and highlights the importance of addressing other factors contributing to behavioural responses when studying mind-wandering during this task. A notable finding in relation to the standard SART, was that while more errors were observed in this version of the task, most of these errors were during periods of focus, raising significant questions about our current understanding of mind-wandering and associated failures of attention.

Keywords: attention, mind-wandering, trial duration rate, Sustained Attention to Response Task (SART)

Procedia PDF Downloads 182
9240 Effect of Synthetic Jet on Wind Turbine Noise

Authors: Reda Mankbadi

Abstract:

The current work explores the use of Synthetic Jet Actuators (SJAs) for control of the acoustic radiation of a low-speed transitioning airfoil in a uniform stream. In the adopted numerical procedure, the actuator is modeled without its resonator cavity through imposing a simple fluctuating-velocity boundary condition at the bottom of the actuator's orifice. The orifice cavity, with the properly defined boundary condition, is then embedded into the airfoil surface. High-accuracy viscous simulations are then conducted to study the effects of the actuation on sound radiated by the airfoil. Results show that SJA can considerably suppress the radiated sound of the airfoil in uniform incoming stream.

Keywords: simulations, aeroacoustics, wind turbine noise, synthetic jet actuators (SJAs)

Procedia PDF Downloads 350
9239 Linear Study of Electrostatic Ion Temperature Gradient Mode with Entropy Gradient Drift and Sheared Ion Flows

Authors: M. Yaqub Khan, Usman Shabbir

Abstract:

History of plasma reveals that continuous struggle of experimentalists and theorists are not fruitful for confinement up to now. It needs a change to bring the research through entropy. Approximately, all the quantities like number density, temperature, electrostatic potential, etc. are connected to entropy. Therefore, it is better to change the way of research. In ion temperature gradient mode with the help of Braginskii model, Boltzmannian electrons, effect of velocity shear is studied inculcating entropy in the magnetoplasma. New dispersion relation is derived for ion temperature gradient mode, and dependence on entropy gradient drift is seen. It is also seen velocity shear enhances the instability but in anomalous transport, its role is not seen significantly but entropy. This work will be helpful to the next step of tokamak and space plasmas.

Keywords: entropy, velocity shear, ion temperature gradient mode, drift

Procedia PDF Downloads 384
9238 Phytochemistry and Alpha-Amylase Inhibitory Activities of Rauvolfia vomitoria (Afzel) Leaves and Picralima nitida (Stapf) Seeds

Authors: Oseyemi Omowunmi Olubomehin, Olufemi Michael Denton

Abstract:

Diabetes mellitus is a disease that is related to the digestion of carbohydrates, proteins and fats and how this affects the blood glucose levels. Various synthetic drugs employed in the management of the disease work through different mechanisms. Keeping postprandial blood glucose levels within acceptable range is a major factor in the management of type 2 diabetes and its complications. Thus, the inhibition of carbohydrate-hydrolyzing enzymes such as α-amylase is an important strategy in lowering postprandial blood glucose levels, but synthetic inhibitors have undesirable side effects like flatulence, diarrhea, gastrointestinal disorders to mention a few. Therefore, it is necessary to identify and explore the α-amylase inhibitors from plants due to their availability, safety, and low costs. In the present study, extracts from the leaves of Rauvolfia vomitoria and seeds of Picralima nitida which are used in the Nigeria traditional system of medicine to treat diabetes were tested for their α-amylase inhibitory effect. The powdered plant samples were subjected to phytochemical screening using standard procedures. The leaves and seeds macerated successively using n-hexane, ethyl acetate and methanol resulted in the crude extracts which at different concentrations (0.1, 0.5 and 1 mg/mL) alongside the standard drug acarbose, were subjected to α-amylase inhibitory assay using the Benfield and Miller methods, with slight modification. Statistical analysis was done using ANOVA, SPSS version 2.0. The phytochemical screening results of the leaves of Rauvolfia vomitoria and the seeds of Picralima nitida showed the presence of alkaloids, tannins, saponins and cardiac glycosides while in addition Rauvolfia vomitoria had phenols and Picralima nitida had terpenoids. The α-amylase assay results revealed that at 1 mg/mL the methanol, hexane, and ethyl acetate extracts of the leaves of Rauvolfia vomitoria gave (15.74, 23.13 and 26.36 %) α-amylase inhibitions respectively, the seeds of Picralima nitida gave (15.50, 30.68, 36.72 %) inhibitions which were not significantly different from the control at p < 0.05, while acarbose gave a significant 56 % inhibition at p < 0.05. The presence of alkaloids, phenols, tannins, steroids, saponins, cardiac glycosides and terpenoids in these plants are responsible for the observed anti-diabetic activity. However, the low percentages of α-amylase inhibition by these plant samples shows that α-amylase inhibition is not the major way by which both plants exhibit their anti-diabetic effect.

Keywords: alpha-amylase, Picralima nitida, postprandial hyperglycemia, Rauvolfia vomitoria

Procedia PDF Downloads 191
9237 The Effect of Peer Pressure and Leisure Boredom on Substance Use Among Adolescents in Low-Income Communities in Capetown

Authors: Gaironeesa Hendricks, Shazly Savahl, Maria Florence

Abstract:

The aim of the study is to determine whether peer pressure and leisure boredom influence substance use among adolescents in low-income communities in Cape Town. Non-probability sampling was used to select 296 adolescents between the ages of 16–18 from schools located in two low-income communities. The measurement tools included the Drug Use Disorders Identification Test, the Resistance to Peer Influence and Leisure Boredom Scales. Multiple regression revealed that the combined influence of peer pressure and leisure boredom predicted substance use, while peer pressure emerged as a stronger predictor than leisure boredom on substance use among adolescents.

Keywords: substance use, peer pressure, leisure boredom, adolescents, multiple regression

Procedia PDF Downloads 597
9236 Cosmic Dust as Dark Matter

Authors: Thomas Prevenslik

Abstract:

Weakly Interacting Massive Particle (WIMP) experiments suggesting dark matter does not exist are consistent with the argument that the long-standing galaxy rotation problem may be resolved without the need for dark matter if the redshift measurements giving the higher than expected galaxy velocities are corrected for the redshift in cosmic dust. Because of the ubiquity of cosmic dust, all velocity measurements in astronomy based on redshift are most likely overstated, e.g., an accelerating Universe expansion need not exist if data showing supernovae brighter than expected based on the redshift/distance relation is corrected for the redshift in dust. Extensions of redshift corrections for cosmic dust to other historical astronomical observations are briefly discussed.

Keywords: alternative theories, cosmic dust redshift, doppler effect, quantum mechanics, quantum electrodynamics

Procedia PDF Downloads 296
9235 DNA Methylation Changes Caused by Lawsone

Authors: Zuzana Poborilova, Anna B. Ohlsson, Torkel Berglund, Anna Vildova, Petr Babula

Abstract:

Lawsone is a pigment that occurs naturally in plants. It has been used as a skin and hair dye for a long time. Moreover, its different biological activities have been reported. The present study focused on the effect of lawsone on a plant cell model represented by tobacco BY-2 cell suspension culture, which is used as a model comparable with the HeLa cells. It has been shown that lawsone inhibits the cell growth in the concentration-dependent manner. In addition, changes in DNA methylation level have been determined. We observed decreasing level of DNA methylation in the presence of increasing concentrations of lawsone. These results were accompanied with overproduction of reactive oxygen species (ROS). Since epigenetic modifications can be caused by different stress factors, there could be a connection between the changes in the level of DNA methylation and ROS production caused by lawsone.

Keywords: DNA methylation, lawsone, naphthoquinone, reactive oxygen species

Procedia PDF Downloads 424
9234 Overview and Future Opportunities of Sarcasm Detection on Social Media Communications

Authors: Samaneh Nadali, Masrah Azrifah Azmi Murad, Nurfadhlina Mohammad Sharef

Abstract:

Sarcasm is a common phenomenon in social media which is a nuanced form of language for stating the opposite of what is implied. Due to the intentional ambiguity, analysis of sarcasm is a difficult task not only for a machine but even for a human. Although sarcasm detection has an important effect on sentiment, it is usually ignored in social media analysis because sarcasm analysis is too complicated. While there is a few systems exist which can detect sarcasm, almost no work has been carried out on a study and the review of the existing work in this area. This survey presents a nearly full image of sarcasm detection techniques and the related fields with brief details. The main contributions of this paper include the illustration of the recent trend of research in the sarcasm analysis and we highlight the gaps and propose a new framework that can be explored.

Keywords: sarcasm detection, sentiment analysis, social media, sarcasm analysis

Procedia PDF Downloads 453
9233 The Moderating Role of Test Anxiety in the Relationships Between Self-Efficacy, Engagement, and Academic Achievement in College Math Courses

Authors: Yuqing Zou, Chunrui Zou, Yichong Cao

Abstract:

Previous research has revealed relationships between self-efficacy (SE), engagement, and academic achievement among students in Western countries, but these relationships remain unknown in college math courses among college students in China. In addition, previous research has shown that test anxiety has a direct effect on engagement and academic achievement. However, how test anxiety affects the relationships between SE, engagement, and academic achievement is still unknown. In this study, the authors aimed to explore the mediating roles of behavioral engagement (BE), emotional engagement (EE), and cognitive engagement (CE) in the association between SE and academic achievement and the moderating role of test anxiety in college math courses. Our hypotheses are that the association between SE and academic achievement was mediated by engagement and that test anxiety played a moderating role in the association. To explore the research questions, the authors collected data through self-reported surveys among 147 students at a northwestern university in China. Self-reported surveys were used to collect data. The motivated strategies for learning questionnaire (MSLQ) (Pintrich, 1991), the metacognitive strategies questionnaire (Wolters, 2004), and the engagement versus disaffection with learning scale (Skinner et al., 2008) were used to assess SE, CE, and BE and EE, respectively. R software was used to analyze the data. The main analyses used were reliability and validity analysis of scales, descriptive statistics analysis of measured variables, correlation analysis, regression analysis, and structural equation modeling (SEM) analysis and moderated mediation analysis to look at the structural relationships between variables at the same time. The SEM analysis indicated that student SE was positively related to BE, EE, and CE and academic achievement. BE, EE, and CE were all positively associated with academic achievement. That is, as the authors expected, higher levels of SE led to higher levels of BE, EE, and CE, and greater academic achievement. Higher levels of BE, EE, and CE led to greater academic achievement. In addition, the moderated mediation analysis found that the path of SE to academic achievement in the model was as significant as expected, as was the moderating effect of test anxiety in the SE-Achievement association. Specifically, test anxiety was found to moderate the association between SE and BE, the association between SE and CE, and the association between EE and Achievement. The authors investigated possible mediating effects of BE, EE, and CE in the associations between SE and academic achievement, and all indirect effects were found to be significant. As for the magnitude of mediations, behavioral engagement was the most important mediator in the SE-Achievement association. This study has implications for college teachers, educators, and students in China regarding ways to promote academic achievement in college math courses, including increasing self-efficacy and engagement and lessening test anxiety toward math.

Keywords: academic engagement, self-efficacy, test anxiety, academic achievement, college math courses, behavioral engagement, cognitive engagement, emotional engagement

Procedia PDF Downloads 92
9232 Combination of Silver-Curcumin Nanoparticle for the Treatment of Root Canal Infection

Authors: M. Gowri, E. K. Girija, V. Ganesh

Abstract:

Background and Significance: Among the dental infections, inflammation and infection of the root canal are common among all age groups. Currently, the management of root canal infections involves cleaning the canal with powerful irrigants followed by intracanal medicament application. Though these treatments have been in vogue for a long time, root canal failures do occur. Treatment for root canal infections is limited due to the anatomical complexity in terms of small micrometer volumes and poor penetration of drugs. Thus, infections of the root canal seem to be a challenge that demands development of new agents that can eradicate C. albicans. Methodology: In the present study, we synthesized and screened silver-curcumin nanoparticle against Candida albicans. Detailed molecular studies were carried out with silver-curcumin nanoparticle on C. albicans pathogenicity. Morphological cell damage and antibiofilm activity of silver-curcumin nanoparticle on C. albicans was studied using scanning electron microscopy (SEM). Biochemical evidence for membrane damage was studied using flow cytometry. Further, the antifungal activity of silver-curcumin nanoparticle was evaluated in an ex vivo dentinal tubule infection model. Results: Screening data showed that silver-curcumin nanoparticle was active against C. albicans. Silver-curcumin nanoparticle exerted time kill effect and post antifungal effect. When used in combination with fluconazole or nystatin, silver-curcumin nanoparticle revealed a minimum inhibitory concentration (MIC) decrease for both drugs used. In-depth molecular studies with silver-curcumin nanoparticle on C. albicans showed that silver-curcumin nanoparticle inhibited yeast to hyphae (Y-H) conversion. Further, SEM images of C. albicans showed that silver-curcumin nanoparticle caused membrane damage and inhibited biofilm formation. Biochemical evidence for membrane damage was confirmed by increased propidium iodide (PI) uptake in flow cytometry. Further, the antifungal activity of silver-curcumin nanoparticle was evaluated in an ex vivo dentinal tubule infection model, which mimics human tooth root canal infection. Confocal laser scanning microscopy studies showed eradication of C. albicans and reduction in colony forming unit (CFU) after 24 h treatment in the infected tooth samples in this model. Conclusion: The results of this study can pave the way for developing new antifungal agents with well deciphered mechanisms of action and can be a promising antifungal agent or medicament against root canal infection.

Keywords: C. albicans, ex vivo dentine model, inhibition of biofilm formation, root canal infection, yeast to hyphae conversion inhibition

Procedia PDF Downloads 206
9231 Assessment of Urban Infrastructure and Health Using Principal Component Analysis and Geographic Information System: A Case of Ahmedabad, India

Authors: Anusha Vaddiraj Pallapu

Abstract:

Across the globe, there is a steady increase in people residing in urban areas. Due to this increase in urban population, urban health is affecting. The major issues identified like overcrowding, air pollution, unhealthy diet, inadequate infrastructure, poor solid waste management systems and insufficient access to health facilities, these issues are gradually clearly observed in health statistics of diseases and deaths rapidly increase in urban areas. Therefore, the present study aims to assess the health statistics and infrastructure services at urban areas to know the cause and effect between Infrastructure, its management and diseases (water borne). Most of the Indian cities have the municipal boundaries, which authorized by their respective municipal corporations and development authorities. Generally, cities have various zones under which municipal wards exist. The paper focuses on the city Ahmedabad, at Gujarat state. Ahmedabad Municipal Corporation (AMC) is divided into six zones namely Central zone, West zone, New-West zone, East zone, North zone, and South zone. Each zone includes various wards within it. Incidence of diseases in Ahmadabad which are linked to infrastructure was identified such as water-borne diseases. Later on, the occurrence of water-borne diseases at urban area was examined at each zone level. The study methodology follows four steps i.e. 1) Pre-Field literature study: Study on Sewerage system in urban areas and its best practices and public health status globally and Indian scenario; 2) Field study: Data collection and interviews of stakeholders regarding heal status and issues at each zone and ward level; 3) Post field: Data analysis with qualitative description of each ward of zones, followed by correlation coefficient analysis between sewerage coverage, diseases and density of each ward using geographic information system mapping (GIS); 4) Identification of reasons: Affected health on each of zone and wards followed by correlation analysis on each reason. The results reveal that the health conditions in Ahmedabad municipal zones or boundaries are effected due to the slums created by the migrated people from various rural and urban areas. It is also observed that due to increase in population water supply and sewerage management is affecting. The overall effect on infrastructure is creating the health diseases which detailed in the paper using geographical information system in Indian city.

Keywords: infrastructure, municipal wards, GIS, water supply, sewerage, medical facilities, water borne diseases

Procedia PDF Downloads 210
9230 Effect of Rotation Speed on Microstructure and Microhardness of AA7039 Rods Joined by Friction Welding

Authors: H. Karakoc, A. Uzun, G. Kırmızı, H. Çinici, R. Çitak

Abstract:

The main objective of this investigation was to apply friction welding for joining of AA7039 rods produced by powder metallurgy. Friction welding joints were carried out using a rotational friction welding machine. Friction welds were obtained under different rotational speeds between (2700 and 2900 rpm). The friction pressure of 10 MPa and friction time of 30 s was kept constant. The cross sections of joints were observed by optical microscopy. The microstructures were analyzed using scanning electron microscope/energy dispersive X-ray spectroscopy. The Vickers micro hardness measurement of the interface was evaluated using a micro hardness testing machine. Finally the results obtained were compared and discussed.

Keywords: Aluminum alloy, powder metallurgy, friction welding, microstructure

Procedia PDF Downloads 362
9229 Optimal Design of Polymer Based Piezoelectric Actuator with Varying Thickness and Length Ratios

Authors: Vineet Tiwari, R. K. Dwivedi, Geetika Srivastava

Abstract:

Piezoelectric cantilevers are exploited for their use in sensors and actuators. In this study, a unimorph cantilever beam is considered as a study element with a piezoelectric polymer Polyvinylidene fluoride (PVDF) layer bonded to a substrate layer. The different substrates like polysilicon, stainless steel and silicon nitride are tried for the study. An effort has been made to optimize and study the effect of the various parameters of the device in order to achieve maximum tip deflection. The variation of the tip displacement of the cantilever with respect to the length ratio of the nonpiezoelectric layer to the piezoelectric layer has been studied. The electric response of this unimorph cantilever beam is simulated with the help of finite element analysis software COMSOL Multiphysics.

Keywords: actuators, cantilever, piezoelectric, sensors, PVDF

Procedia PDF Downloads 428
9228 Temperature Profile Modelling in Flexible Pavement Design

Authors: Csaba Tóth, Éva Lakatos, László Pethő, Seoyoung Cho

Abstract:

The temperature effect on asphalt pavement structure is a crucial factor at the design stage. In this paper, by applying the German guidelines for temperature along the asphalt depth is estimated. The aim is to consider temperature profiles in different seasons in numerical modelling. The model is built with an elastic and isotropic solid element with 19 subdivisions of asphalt layers to reflect the temperature variation. Comparison with the simple three-layer pavement system (asphalt layers, base, and subgrade layers) will be followed to see the difference in result without temperature variation along with the depth. Finally, the fatigue life calculation was checked to prove the validity of the methodology of considering the temperature in the numerical modelling.

Keywords: temperature profile, flexible pavement modeling, finite element method, temperature modeling

Procedia PDF Downloads 266
9227 A Dynamic Spatial Panel Data Analysis on Renter-Occupied Multifamily Housing DC

Authors: Jose Funes, Jeff Sauer, Laixiang Sun

Abstract:

This research examines determinants of multifamily housing development and spillovers in the District of Columbia. A range of socioeconomic factors related to income distribution, productivity, and land use policies are thought to influence the development in contemporary U.S. multifamily housing markets. The analysis leverages data from the American Community Survey to construct panel datasets spanning from 2010 to 2019. Using spatial regression, we identify several socioeconomic measures and land use policies both positively and negatively associated with new housing supply. We contextualize housing estimates related to race in relation to uneven development in the contemporary D.C. housing supply.

Keywords: neighborhood effect, sorting, spatial spillovers, multifamily housing

Procedia PDF Downloads 99