Search results for: behavioral tests
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 5361

Search results for: behavioral tests

4071 Exploring Coping Strategies among Caregivers of Children Who Have Survived Cancer

Authors: Noor Ismael, Somaya Malkawi, Sherin Al Awady, Taleb Ismael

Abstract:

Background/Significance: Cancer is a serious health condition that affects individuals’ quality of life during and after the course of this condition. Children who have survived cancer and their caregivers may deal with residual physical, cognitive or social disabilities. There is little research on caregivers’ health and wellbeing after cancer. To the authors’ best knowledge; there is no specific research about how caregivers cope with everyday stressors after cancer. Therefore, this study aimed to explore the coping strategies that caregivers of children who have survived cancer utilize to overcome everyday stressors. Methods: This study utilized a descriptive survey design. The sample consisted of 103 caregivers, who visited the health and wellness clinic at a national cancer center (additional demographics are presented in the results). The sample included caregivers of children who were off cancer treatments for at least two years from the beginning of data collection. The institution’s internal review board approved this study. Caregivers who agreed to participate completed the survey. The survey collected caregiver reported demographic information and the Brief COPE which measures caregivers' frequency of engaging in certain coping strategies. The Brief COPE consisted of 14 coping sub-scales, which are self-distraction, active coping, denial, substance use, use of emotional support, use of instrumental support, behavioral disengagement, venting, positive reframing, planning, humor, acceptance, religion, and self-blame. Data analyses included calculating sub-scales’ scores for the fourteen coping strategies and analysis of frequencies of demographics and coping strategies. Results: The 103 caregivers who participated in this study were 62% mothers, 80% married, 45% finished high school, 50% do not work outside the house, and 60% have low family income. Result showed that religious coping (66%) and acceptance (60%) were the most utilized coping strategies, followed by positive reframing (45%), active coping (44%) and planning (43%). The least utilized coping strategies in our sample were humor (5%), behavioral disengagement (8%), and substance-use (10%). Conclusions: Caregivers of children who have survived cancer mostly utilize religious coping and acceptance in dealing with everyday stressors. Because these coping strategies do not directly solve stressors like active coping and planning coping strategies, it is important to support caregivers in choosing and implementing effective coping strategies. Knowing from our results that some caregivers may utilize substance use as a coping strategy, which has negative health effects on caregivers and their children, there must be direct interventions that target these caregivers and their families.

Keywords: caregivers, cancer, stress, coping

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4070 Effect of Different Sterilization Processes on Drug Loaded Silicone-Hydrogel

Authors: Raquel Galante, Marina Braga, Daniela Ghisleni, Terezinha J. A. Pinto, Rogério Colaço, Ana Paula Serro

Abstract:

The sensitive nature of soft biomaterials, such as hydrogels, renders their sterilization a particularly challenging task for the biomedical industry. Widely used contact lenses are now studied as promising platforms for topical corneal drug delivery. However, to the best of the authors knowledge, the influence of sterilization methods on these systems has yet to be evaluated. The main goal of this study was to understand how different pairs drug-hydrogel would interact under an ozone-based sterilization method in comparison with two conventional processes (steam heat and gamma irradiation). For that, Si-Hy containing hydroxylethyl methacrylate (HEMA) and [tris(trimethylsiloxy)silyl]propyl methacrylate (TRIS) was produced and soaked in different drug solutions, commonly used for the treatment of ocular diseases (levofloxacin, chlorhexidine, diclofenac and timolol maleate). The drug release profiles and main material properties were evaluated before and after the sterilization. Namely, swelling capacity was determined by water uptake studies, transparency was accessed by UV-Vis spectroscopy, surface topography/morphology by scanning electron microscopy (SEM) and mechanical properties by performing tensile tests. The drug released was quantified by high performance liquid chromatography (HPLC). The effectiveness of the sterilization procedures was assured by performing sterility tests. Ozone gas method led to a significant reduction of drug released and to the formation of degradation products specially for diclofenac and levofloxacin. Gamma irradiation led to darkening of the loaded Si-Hys and to the complete degradation of levofloxacin. Steam heat led to smoother surfaces and to a decrease of the amount of drug released, however, with no formation of degradation products. This difference in the total drug released could be the related to drug/polymer interactions promoted by the sterilization conditions in presence of the drug. Our findings offer important insights that, in turn, could be a useful contribution to the safe development of actual products.

Keywords: drug delivery, silicone hydrogels, sterilization, gamma irradiation, steam heat, ozone gas

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4069 Studies on Biojetfuel Obtained from Vegetable Oil: Process Characteristics, Engine Performance and Their Comparison with Mineral Jetfuel

Authors: F. Murilo T. Luna, Vanessa F. Oliveira, Alysson Rocha, Expedito J. S. Parente, Andre V. Bueno, Matheus C. M. Farias, Celio L. Cavalcante Jr.

Abstract:

Aviation jetfuel used in aircraft gas-turbine engines is customarily obtained from the kerosene distillation fraction of petroleum (150-275°C). Mineral jetfuel consists of a hydrocarbon mixture containing paraffins, naphthenes and aromatics, with low olefins content. In order to ensure their safety, several stringent requirements must be met by jetfuels, such as: high energy density, low risk of explosion, physicochemical stability and low pour point. In this context, aviation fuels eventually obtained from biofeedstocks (which have been coined as ‘biojetfuel’), must be used as ‘drop in’, since adaptations in aircraft engines are not desirable, to avoid problems with their operation reliability. Thus, potential aviation biofuels must present the same composition and physicochemical properties of conventional jetfuel. Among the potential feedtstocks for aviation biofuel, the babaçu oil, extracted from a palm tree extensively found in some regions of Brazil, contains expressive quantities of short chain saturated fatty acids and may be an interesting choice for biojetfuel production. In this study, biojetfuel was synthesized through homogeneous transesterification of babaçu oil using methanol and its properties were compared with petroleum-based jetfuel through measurements of oxidative stability, physicochemical properties and low temperature properties. The transesterification reactions were carried out using methanol and after decantation/wash procedures, the methyl esters were purified by molecular distillation under high vacuum at different temperatures. The results indicate significant improvement in oxidative stability and pour point of the products when compared to the fresh oil. After optimization of operational conditions, potential biojetfuel samples were obtained, consisting mainly of C8 esters, showing low pour point and high oxidative stability. Jet engine tests are being conducted in an automated test bed equipped with pollutant emissions analysers to study the operational performance of the biojetfuel that was obtained and compare with a mineral commercial jetfuel.

Keywords: biojetfuel, babaçu oil, oxidative stability, engine tests

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4068 Neurocognitive and Executive Function in Cocaine Addicted Females

Authors: Gwendolyn Royal-Smith

Abstract:

Cocaine ranks as one of the world’s most addictive and commonly abused stimulant drugs. Recent evidence indicates that the abuse of cocaine has risen so quickly among females that this group now accounts for about 40 percent of all users in the United States. Neuropsychological studies have demonstrated that specific neural activation patterns carry higher risks for neurocognitive and executive function in cocaine addicted females thereby increasing their vulnerability for poorer treatment outcomes and more frequent post-treatment relapse when compared to males. This study examined secondary data with a convenience sample of 164 cocaine addicted male and females to assess neurocognitive and executive function. The principal objective of this study was to assess whether individual performance on the Stroop Word Color Task is predictive of treatment success by gender. A second objective of the study evaluated whether individual performance employing neurocognitive measures including the Stroop Word-Color task, the Rey Auditory Verbal Learning Test (RALVT), the Iowa Gambling Task, the Wisconsin Card Sorting Task (WISCT), the total score from the Barratte Impulsiveness Scale (Version 11) (BIS-11) and the total score from the Frontal Systems Behavioral Scale (FrSBE) test demonstrated differences in neurocognitive and executive function performance by gender. Logistic regression models were employed utilizing a covariate adjusted model application. Initial analyses of the Stroop Word color tasks indicated significant differences in the performance of males and females, with females experiencing more challenges in derived interference reaction time and associate recall ability. In early testing including the Rey Auditory Verbal Learning Test (RALVT), the number of advantageous vs disadvantageous cards from the Iowa Gambling Task, the number of perseverance errors from the Wisconsin Card Sorting Task (WISCT), the total score from the Barratte Impulsiveness Scale (Version 11) (BIS-11) and the total score from the Frontal Systems Behavioral Scale, results were mixed with women scoring lower in multiple indicators in both neurocognitive and executive function.

Keywords: cocaine addiction, gender, neuropsychology, neurocognitive, executive function

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4067 A Current Problem for Steel Bridges: Fatigue Assessment of Seams´ Repair

Authors: H. Pasternak, A. Chwastek

Abstract:

The paper describes the results from a research project about repair of welds. The repair was carried out by grinding the flawed seams and re-welding them. The main task was to determine the FAT classes of original state and after repair of seams according to the assessment procedures, such as nominal, structural and effective notch stress approach. The first part shows the results of the tests, the second part encloses numerical analysis and evaluation of results to determine the fatigue strength classes according to three assessment procedures.

Keywords: cyclic loading, fatigue crack, post-weld treatment, seams’ repair

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4066 Investigation of Riprap Stability on Roughness Bridge Pier in River Bend

Authors: A. Alireza Masjedi, B. Amir Taeedi

Abstract:

In this research, by placing the two cylindrical piers without roughness and with roughness with riprap around its, they proceeded to a series of tests. Experiments were done by three relative diameters of riprap with density 2.1 and one rate of discharge 27 lit/s under pure water condition. In each experiment, flow depth measured in terms of failure threshold then stability number calculated by using data obtained. The results of the research showed that the riprap stability in pier with roughness is more pier without roughness because of the pier with roughness is sharp-pointed and reduced horseshoe vortex.

Keywords: riprap stability, roughness, river bend, froude number

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4065 Effect of Riprap Stability on Roughness Bridge Pier in River Bend

Authors: Alireza Masjedi, Amir Taeedi

Abstract:

In this research, by placing the two cylindrical piers without roughness and with roughness with riprap around its, they proceeded to a series of tests. Experiments were done by three relative diameters of riprap with density 2.1 and one rate of discharge 27 lit/s under pure water condition. In each experiment, flow depth measured in terms of failure threshold then stability number calculated by using data obtained. The results of the research showed that the riprap stability in pier with roughness is more pier without roughness because of the pier with roughness is sharp-pointed and reduced horseshoe vortex.

Keywords: riprap stability, roughness, river bend, froude number

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4064 Impact of Gaming Environment in Education

Authors: Md. Ataur Rahman Bhuiyan, Quazi Mahabubul Hasan, Md. Rifat Ullah

Abstract:

In this research, we did explore the effectiveness of the gaming environment in education and compared it with the traditional education system. We take several workshops in both learning environments. We measured student’s performance by providing a grading score (by professional academics) on their attitude in different criteria. We also collect data from survey questionnaires to understand student’s experiences towards education and study. Finally, we examine the impact of the different learning environments by applying statistical hypothesis tests, the T-test, and the ANOVA test.

Keywords: gamification, game-based learning, education, statistical analysis, human-computer interaction

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4063 Public Health Campaign to Eradicate Hepatitis C Virus during the Covid-19 Emergency in the North-East of Italy

Authors: Emanuela Zilli, Antonio Madia, Milvia Marchiori, Paola Anello, Chiara Cabbia, Emanuela Velo, Delia Campagnolo, Michele Scomazzon, Emanuela Salvatico, S. Tikvina, Antonio Miotti

Abstract:

Hepatitis C is an inflammation of the liver caused by the hepatitis C virus (HCV). Antiviral medicines can cure more than 95% of cases of hepatitis C infection, but access to diagnosis and treatment remains low. The ULSS 6 Euganea – Health Trust has implemented a campaign to eradicate hepatitis C in the province of Padua (North-East of Italy), which can be subdivided into three areas: North (300.000 inhabitants), Centre (400.000) and South (300.000). In September 2021, the project was launched in the Northern area; a set of brochures was distributed in outpatient services, general practitioners’ clinics and offices, community pharmacy services, social health districts, and through social networks. The Hepatology Service contacted 460 patients selected by the Clinical Laboratory (positivity for HCV antibodies): 83 patients (18.0%) had been already cured of HCV infection, missing or deceased; 377 patients (82.0%) met the criteria to be eligible for HCV eradication therapy and were therefore included in a Day Service specific agenda and followed by a multidisciplinary team of healthcare professionals, with a dedicated telephone line. Haemato-chemical tests, general medical check-ups and ultrasound tests with fibroscan were performed. Patients were tested for Sars-CoV-2 positivity; those not yet vaccinated against Covid-19 were encouraged to complete the vaccination scheme. All 377 patients (100%) received HCV eradication therapy at the community pharmacy service; a detailed explanation of how to take their medication was provided. At the end of the first phase, Covid-19 vaccination rate was 100% (377/377), including patients already vaccinated and new-vaccinated. Check-up appointments were arranged after 2 or 3 months, according to the treatment plan. The awareness campaign and the organization of HCV eradication therapy service by ULSS 6 Euganea are proving to be effective; the project is now going to be applied to Central and Southern areas of the province (1.132 patients).

Keywords: public health, HCV-eradication, Covid-19 emergency, health communication strategies

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4062 Effect of Varying Zener-Hollomon Parameter (Temperature and Flow Stress) and Stress Relaxation on Creep Response of Hot Deformed AA3104 Can Body Stock

Authors: Oyindamola Kayode, Sarah George, Roberto Borrageiro, Mike Shirran

Abstract:

A phenomenon identified by our industrial partner has experienced sag on AA3104 can body stock (CBS) transfer bar during transportation of the slab from the breakdown mill to the finishing mill. Excessive sag results in bottom scuffing of the slab onto the roller table, resulting in surface defects on the final product. It has been found that increasing the strain rate on the breakdown mill final pass results in a slab resistant to sag. The creep response for materials hot deformed at different Zener–Holloman parameter values needs to be evaluated experimentally to gain better understanding of the operating mechanism. This study investigates this identified phenomenon through laboratory simulation of the breakdown mill conditions for various strain rates by utilizing the Gleeble at UCT Centre for Materials Engineering. The experiment will determine the creep response for a range of conditions as well as quantifying the associated material microstructure (sub-grain size, grain structure etc). The experimental matrices were determined based on experimental conditions approximate to industrial hot breakdown rolling and carried out on the Gleeble 3800 at the Centre for Materials Engineering, University of Cape Town. Plane strain compression samples were used for this series of tests at an applied load that allow for better contact and exaggerated creep displacement. A tantalum barrier layer was used for increased conductivity and decreased risk of anvil welding. One set of tests with no in-situ hold time was performed, where the samples were quenched after deformation. The samples were retained for microstructure analysis of the micrographs from the light microscopy (LM), quantitative data and images from scanning electron microscopy (SEM) and energy dispersive X-ray (EDX), sub-grain size and grain structure from electron back scattered diffraction (EBSD).

Keywords: aluminium alloy, can-body stock, hot rolling, creep response, Zener-Hollomon parameter

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4061 Influential Parameters in Estimating Soil Properties from Cone Penetrating Test: An Artificial Neural Network Study

Authors: Ahmed G. Mahgoub, Dahlia H. Hafez, Mostafa A. Abu Kiefa

Abstract:

The Cone Penetration Test (CPT) is a common in-situ test which generally investigates a much greater volume of soil more quickly than possible from sampling and laboratory tests. Therefore, it has the potential to realize both cost savings and assessment of soil properties rapidly and continuously. The principle objective of this paper is to demonstrate the feasibility and efficiency of using artificial neural networks (ANNs) to predict the soil angle of internal friction (Φ) and the soil modulus of elasticity (E) from CPT results considering the uncertainties and non-linearities of the soil. In addition, ANNs are used to study the influence of different parameters and recommend which parameters should be included as input parameters to improve the prediction. Neural networks discover relationships in the input data sets through the iterative presentation of the data and intrinsic mapping characteristics of neural topologies. General Regression Neural Network (GRNN) is one of the powerful neural network architectures which is utilized in this study. A large amount of field and experimental data including CPT results, plate load tests, direct shear box, grain size distribution and calculated data of overburden pressure was obtained from a large project in the United Arab Emirates. This data was used for the training and the validation of the neural network. A comparison was made between the obtained results from the ANN's approach, and some common traditional correlations that predict Φ and E from CPT results with respect to the actual results of the collected data. The results show that the ANN is a very powerful tool. Very good agreement was obtained between estimated results from ANN and actual measured results with comparison to other correlations available in the literature. The study recommends some easily available parameters that should be included in the estimation of the soil properties to improve the prediction models. It is shown that the use of friction ration in the estimation of Φ and the use of fines content in the estimation of E considerable improve the prediction models.

Keywords: angle of internal friction, cone penetrating test, general regression neural network, soil modulus of elasticity

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4060 Visual and Verbal Imagination in a Bilingual Context

Authors: Erzsebet Gulyas

Abstract:

Our inner world, our imagination, and our way of thinking are invisible and inaudible to others, but they influence our behavior. To investigate the relationship between thinking and language use, we created a test in Hungarian using ideas from the literature. The test prompts participants to make decisions based on visual images derived from the written information presented. There is a correlation (r=0.5) between the test result and the self-assessment of the visual imagery vividness and the visual and verbal components of internal representations measured by self-report questionnaires, as well as with responses to language-use inquiries in the background questionnaire. 56 university students completed the tests, and SPSS was used to analyze the data.

Keywords: imagination, internal representations, verbalization, visualization

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4059 Risk-Realistic Decision Support Intervention for Women in the Workplace

Authors: Joshua Midha

Abstract:

This paper provides an evaluation of an intervention designed to promote a risk-realistic environment for women in the workplace and regulate their risk-related decision-making. In past research, women -specifically women of color- are highly risk-averse, and this may prove to be an innate obstacle in gender progress in corporations. By helping women see the risks and the benefits and increasing potential benefits, we can increase the chances of success in the workplace. Our intervention was a success and significantly increased comfort, trust, and frequency in the use of decision-making skills in the workplace. In this paper, we explore the intervention, the methods, the results, and the implications.

Keywords: behavioral economics, decision support, risk, gender equality

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4058 Using Wavelet Uncertainty Relations in Quantum Mechanics: From Trajectories Foam to Newtonian Determinism

Authors: Paulo Castro, J. R. Croca, M. Gatta, R. Moreira

Abstract:

Owing to the development of quantum mechanics, we will contextualize the foundations of the theory on the Fourier analysis framework, thus stating the unavoidable philosophical conclusions drawn by Niels Bohr. We will then introduce an alternative way of describing the undulatory aspects of quantum entities by using gaussian Morlet wavelets. The description has its roots in de Broglie's realistic program for quantum physics. It so happens that using wavelets it is possible to formulate a more general set of uncertainty relations. A set from which it is possible to theoretically describe both ends of the behavioral spectrum in reality: the indeterministic quantum trajectorial foam and the perfectly drawn Newtonian trajectories.

Keywords: philosophy of quantum mechanics, quantum realism, morlet wavelets, uncertainty relations, determinism

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4057 The Establishment and Application of TRACE/FRAPTRAN Model for Kuosheng Nuclear Power Plant

Authors: S. W. Chen, W. K. Lin, J. R. Wang, C. Shih, H. T. Lin, H. C. Chang, W. Y. Li

Abstract:

Kuosheng nuclear power plant (NPP) is a BWR/6 type NPP and located on the northern coast of Taiwan. First, Kuosheng NPP TRACE model were developed in this research. In order to assess the system response of Kuosheng NPP TRACE model, startup tests data were used to evaluate Kuosheng NPP TRACE model. Second, the over pressurization transient analysis of Kuosheng NPP TRACE model was performed. Besides, in order to confirm the mechanical property and integrity of fuel rods, FRAPTRAN analysis was also performed in this study.

Keywords: TRACE, safety analysis, BWR/6, FRAPTRA

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4056 Effects of Active Muscle Contraction in a Car Occupant in Whiplash Injury

Authors: Nisha Nandlal Sharma, Julaluk Carmai, Saiprasit Koetniyom, Bernd Markert

Abstract:

Whiplash Injuries are usually associated with car accidents. The sudden forward or backward jerk to head causes neck strain, which is the result of damage to the muscle or tendons. Neck pain and headaches are the two most common symptoms of whiplash. Symptoms of whiplash are commonly reported in studies but the Injury mechanism is poorly understood. Neck muscles are the most important factor to study the neck Injury. This study focuses on the development of finite element (FE) model of human neck muscle to study the whiplash injury mechanism and effect of active muscle contraction on occupant kinematics. A detailed study of Injury mechanism will promote development and evaluation of new safety systems in cars, hence reducing the occurrence of severe injuries to the occupant. In present study, an active human finite element (FE) model with 3D neck muscle model is developed. Neck muscle was modeled with a combination of solid tetrahedral elements and 1D beam elements. Muscle active properties were represented by beam elements whereas, passive properties by solid tetrahedral elements. To generate muscular force according to inputted activation levels, Hill-type muscle model was applied to beam elements. To simulate non-linear passive properties of muscle, solid elements were modeled with rubber/foam material model. Material properties were assigned from published experimental tests. Some important muscles were then inserted into THUMS (Total Human Model for Safety) 50th percentile male pedestrian model. To reduce the simulation time required, THUMS lower body parts were not included. Posterior to muscle insertion, THUMS was given a boundary conditions similar to experimental tests. The model was exposed to 4g and 7g rear impacts as these load impacts are close to low speed impacts causing whiplash. The effect of muscle activation level on occupant kinematics during whiplash was analyzed.

Keywords: finite element model, muscle activation, neck muscle, whiplash injury prevention

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4055 Effect of Oil Contamination on the Liquefaction Behavior of Sandy Soils

Authors: Seyed Abolhasan Naeini, Mohammad Mahdi Shojaedin

Abstract:

Oil leakage from the pipelines and the tanks carrying them, or during oil extraction, could lead to the changes in the characteristics and properties of the soil. In this paper, conducting a series of experimental cyclic triaxial tests, the effects of oil contamination on the liquefaction potential of sandy soils is investigated. The studied specimens are prepared by mixing the Firoozkuh sand with crude oil in 4, 8 and 12 percent by soil dry weight. The results show that the oil contamination up to 8% causes an increase in the soil liquefaction resistance and then with increase in the contamination, the liquefaction resistance decreases.

Keywords: cyclic triaxial test, liquefaction resistance, oil contamination, sandy soil

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4054 Combustion Variability and Uniqueness in Cylinders of a Radial Aircraft Piston Engine

Authors: Michal Geca, Grzegorz Baranski, Ksenia Siadkowska

Abstract:

The work is a part of the project which aims at developing innovative power and control systems for the high power aircraft piston engine ASz62IR. Developed electronically controlled ignition system will reduce emissions of toxic compounds as a result of lowered fuel consumption, optimized combustion and engine capability of efficient combustion of ecological fuels. The tested unit is an air-cooled four-stroke gasoline engine of 9 cylinders in a radial setup, mechanically charged by a radial compressor powered by the engine crankshaft. The total engine cubic capac-ity is 29.87 dm3, and the compression ratio is 6.4:1. The maximum take-off power is 1000 HP at 2200 rpm. The maximum fuel consumption is 280 kg/h. Engine powers aircrafts: An-2, M-18 „Dromader”, DHC-3 „OTTER”, DC-3 „Dakota”, GAF-125 „HAWK” i Y5. The main problems of the engine includes the imbalanced work of cylinders. The non-uniformity value in each cylinder results in non-uniformity of their work. In radial engine cylinders arrangement causes that the mixture movement that takes place in accordance (lower cylinder) or the opposite (upper cylinders) to the direction of gravity. Preliminary tests confirmed the presence of uneven workflow of individual cylinders. The phenomenon is most intense at low speed. The non-uniformity is visible on the waveform of cylinder pressure. Therefore two studies were conducted to determine the impact of this phenomenon on the engine performance: simulation and real tests. Simplified simulation was conducted on the element of the intake system coated with fuel film. The study shows that there is an effect of gravity on the movement of the fuel film inside the radial engine intake channels. Both in the lower and the upper inlet channels the film flows downwards. It follows from the fact that gravity assists the movement of the film in the lower cylinder channels and prevents the movement in the upper cylinder channels. Real tests on aircraft engine ASz62IR was conducted in transients condition (rapid change of the excess air in each cylinder were performed. Calculations were conducted for mass of fuel reaching the cylinders theoretically and really and on this basis, the factors of fuel evaporation “x” were determined. Therefore a simplified model of the fuel supply to cylinder was adopted. Model includes time constant of the fuel film τ, the number of engine transport cycles of non-evaporating fuel along the intake pipe γ and time between next cycles Δt. The calculation results of identification of the model parameters are presented in the form of radar graphs. The figures shows the averages declines and increases of the injection time and the average values for both types of stroke. These studies shown, that the change of the position of the cylinder will cause changes in the formation of fuel-air mixture and thus changes in the combustion process. Based on the results of the work of simulation and experiments was possible to develop individual algorithms for ignition control. This work has been financed by the Polish National Centre for Research and Development, INNOLOT, under Grant Agreement No. INNOLOT/I/1/NCBR/2013.

Keywords: radial engine, ignition system, non-uniformity, combustion process

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4053 Comparative Study of Impedance Parameters for 42CrMo4 Steel Nitrided and Exposed at Electrochemical Corrosion

Authors: M. H. Belahssen, S. Benramache

Abstract:

This paper presents corrosion behavior of alloy 42CrMo4 steel nitrided by plasma. Different samples nitrided were tested. The corrosion behavior was evaluated by electrochemical impedance spectroscopy and the tests were carried out in acid chloride solution 1M. The best corrosion protection was observed for nitrided samples. The aim of this work is to compare equivalents circuits corresponding to Nyquist curves simulated and experimental and select who gives best results of impedance parameters with lowest error.

Keywords: pasma nitriding, steel, alloy 42CrMo4, elecrochemistry, corrosion behavior

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4052 Mortar Positioning Effects on Uniaxial Compression Behavior in Hollow Concrete Block Masonry

Authors: José Álvarez Pérez, Ramón García Cedeño, Gerardo Fajardo-San Miguel, Jorge H. Chávez Gómez, Franco A. Carpio Santamaría, Milena Mesa Lavista

Abstract:

The uniaxial compressive strength and modulus of elasticity in hollow concrete block masonry (HCBM) represent key mechanical properties for structural design considerations. These properties are obtained through experimental tests conducted on prisms or wallettes and depend on various factors, with the HCB contributing significantly to overall strength. One influential factor in the compressive behaviour of masonry is the thickness and method of mortar placement. Mexican regulations stipulate mortar placement over the entire net area (full-shell) for strength computation based on the gross area. However, in professional practice, there's a growing trend to place mortar solely on the lateral faces. Conversely, the United States of America standard dictates mortar placement and computation over the net area of HCB. The Canadian standard specifies mortar placement solely on the lateral face (Face-Shell-Bedding), where computation necessitates the use of the effective load area, corresponding to the mortar's placement area. This research aims to evaluate the influence of different mortar placement methods on the axial compression behaviour of HCBM. To achieve this, an experimental campaign was conducted, including: (1) 10 HCB specimens with mortar on the entire net area, (2) 10 HCB specimens with mortar placed on the lateral faces, (3) 10 prisms of 2-course HCB under axial compression with mortar in full-shell, (4) 10 prisms of 2-course HCB under axial compression with mortar in face-shell-bedding, (5) 10 prisms of 3-course HCB under axial compression with mortar in full-shell, (6) 10 prisms of 3-course HCB under axial compression with mortar in face-shell-bedding, (7) 10 prisms of 4-course HCB under axial compression with mortar in full-shell, and, (8) 10 prisms of 4-course HCB under axial compression with mortar in face-shell-bedding. A combination of sulphur and fly ash in a 2:1 ratio was used for the capping material, meeting the average compressive strength requirement of over 35 MPa as per NMX-C-036 standards. Additionally, a mortar with a strength of over 17 MPa was utilized for the prisms. The results indicate that prisms with mortar placed over the full-shell exhibit higher strength compared to those with mortar over the face-shell-bedding. However, the elastic modulus was lower for prisms with mortar placement over the full-shell compared to face-shell bedding.

Keywords: masonry, hollow concrete blocks, mortar placement, prisms tests

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4051 Use of Short Piles for Stabilizing the Side Slope of the Road Embankment along the Canal

Authors: Monapat Sasingha, Suttisak Soralump

Abstract:

This research presents the behavior of slope of the road along the canal stabilized by short piles. In this investigation, the centrifuge machine was used, modelling the condition of the water levels in the canal. The centrifuge tests were performed at 35 g. To observe the movement of the soil, visual analysis was performed to evaluate the failure behavior. Conclusively, the use of short piles to stabilize the canal slope proved to be an effective solution. However, the certain amount of settlement was found behind the short pile rows.

Keywords: centrifuge test, slope failure, embankment, stability of slope

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4050 An Open Trial of Mobile-Assisted Cognitive Behavioral Therapy for Negative Symptoms in Schizophrenia: Pupillometry Predictors of Outcome

Authors: Eric Granholm, Christophe Delay, Jason Holden, Peter Link

Abstract:

Negative symptoms are an important unmet treatment needed for schizophrenia. We conducted an open trial of a novel blended intervention called mobile-assisted cognitive behavior therapy for negative symptoms (mCBTn). mCBTn is a weekly group therapy intervention combining in-person and smartphone-based CBT (CBT2go app) to improve experiential negative symptoms in people with schizophrenia. Both the therapy group and CBT2go app included recovery goal setting, thought challenging, scheduling of pleasurable activities and social interactions, and pleasure savoring interventions to modify defeatist attitudes, a target mechanism associated with negative symptoms, and improve experiential negative symptoms. We tested whether participants with schizophrenia or schizoaffective disorder (N=31) who met prospective criteria for persistent negative symptoms showed improvement in experiential negative symptoms. Retention was excellent (87% at 18 weeks) and severity of defeatist attitudes and motivation and pleasure negative symptoms declined significantly in mCBTn with large effect sizes. We also tested whether pupillary responses, a measure of cognitive effort, predicted improvement in negative symptoms mCBTn. Pupillary responses were recorded at baseline using a Tobii pupillometer during the digit span task with 3-, 6- and 9-digit spans. Mixed models showed that greater dilation during the task at baseline significantly predicted a greater reduction in experiential negative symptoms. Pupillary responses may provide a much-needed prognostic biomarker of which patients are most likely to benefit from CBT. Greater pupil dilation during a cognitive task predicted greater improvement in experiential negative symptoms. Pupil dilation has been linked to motivation and engagement of executive control, so these factors may contribute to benefits in interventions that train cognitive skills to manage negative thoughts and emotions. The findings suggest mCBTn is a feasible and effective treatment for experiential negative symptoms and justify a larger randomized controlled clinical trial. The findings also provide support for the defeatist attitude model of experiential negative symptoms and suggest that mobile-assisted interventions like mCBTn can strengthen and shorten intensive psychosocial interventions for schizophrenia.

Keywords: cognitive-behavioral therapy, mobile interventions, negative symptoms, pupillometry schizophrenia

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4049 Neuro-Epigenetic Changes on Diabetes Induced-Synaptic Fidelity in Brain

Authors: Valencia Fernandes, Dharmendra Kumar Khatri, Shashi Bala Singh

Abstract:

Background and Aim: Epigenetics are the inaudible signatures of several pathological processes in the brain. This study understands the influence of DNA methylation, a major epigenetic modification, in the prefrontal cortex and hippocampus of the diabetic brain and its notable effect on the cellular chaperones and synaptic proteins. Method: Chronic high fat diet and STZ-induced diabetic mice were studied for cognitive dysfunction, and global DNA methylation, as well as DNA methyltransferase (DNMT) activity, were assessed. Further, the cellular chaperones and synaptic proteins were examined using DNMT inhibitor, 5-aza-2′-deoxycytidine (5-aza-dC)-via intracerebroventricular injection. Moreover, % methylation of these synaptic proteins were also studied so as to correlate its epigenetic involvement. Computationally, its interaction with the DNMT enzyme were also studied using bioinformatic tools. Histological studies for morphological alterations and neuronal degeneration were also studied. Neurogenesis, a characteristic marker for new learning and memory formation, was also assessed via the BrdU staining. Finally, the most important behavioral studies, including the Morris water maze, Y maze, passive avoidance, and Novel object recognition test, were performed to study its cognitive functions. Results: Altered global DNA methylation and increased levels of DNMTs within the nucleus were confirmed in the cortex and hippocampus of the diseased mice, suggesting hypermethylation at a genetic level. Treatment with AzadC, a global DNA demethylating agent, ameliorated the protein and gene expression of the cellular chaperones and synaptic fidelity. Furthermore, the methylation analysis profile showed hypermethylation of the hsf1 protein, a master regulator for chaperones and thus, confirmed the epigenetic involvement in the diseased brain. Morphological improvements and decreased neurodegeneration, along with enhanced neurogenesis in the treatment group, suggest that epigenetic modulations do participate in learning and memory. This is supported by the improved behavioral test battery seen in the treatment group. Conclusion: DNA methylation could possibly accord in dysregulating the memory-associated proteins at chronic stages in type 2 diabetes. This could suggest a substantial contribution to the underlying pathophysiology of several metabolic syndromes like insulin resistance, obesity and also participate in transitioning this damage centrally, such as cognitive dysfunction.

Keywords: epigenetics, cognition, chaperones, DNA methylation

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4048 Performance and Specific Emissions of an SI Engine Using Anhydrous Ethanol–Gasoline Blends in the City of Bogota

Authors: Alexander García Mariaca, Rodrigo Morillo Castaño, Juan Rolón Ríos

Abstract:

The government of Colombia has promoted the use of biofuels in the last 20 years through laws and resolutions, which regulate their use, with the objective to improve the atmospheric air quality and to promote Colombian agricultural industry. However, despite the use of blends of biofuels with fossil fuels, the air quality in large cities does not get better, this deterioration in the air is mainly caused by mobile sources that working with spark ignition internal combustion engines (SI-ICE), operating with a mixture in volume of 90 % gasoline and 10 % ethanol called E10, that for the case of Bogota represent 84 % of the fleet. Another problem is that Colombia has big cities located above 2200 masl and there are no accurate studies on the impact that the E10 mixture could cause in the emissions and performance of SI-ICE. This study aims to establish the optimal blend between gasoline ethanol in which an SI engine operates more efficiently in urban centres located at 2600 masl. The test was developed on SI engine four-stroke, single cylinder, naturally aspirated and with carburettor for the fuel supply using blends of gasoline and anhydrous ethanol in different ratios E10, E15, E20, E40, E60, E85 and E100. These tests were conducted in the city of Bogota, which is located at 2600 masl, with the engine operating at 3600 rpm and at 25, 50, 75 and 100% of load. The results show that the performance variables as engine brake torque, brake power and brake thermal efficiency decrease, while brake specific fuel consumption increases with the rise in the percentage of ethanol in the mixture. On the other hand, the specific emissions of CO2 and NOx present increases while specific emissions of CO and HC decreases compared to those produced by gasoline. From the tests, it is concluded that the SI-ICE worked more efficiently with the E40 mixture, where was obtained an increases of the brake power of 8.81 % and a reduction on brake specific fuel consumption of 2.5 %, coupled with a reduction in the specific emissions of CO2, HC and CO in 9.72, 52.88 and 76.66 % respectively compared to the results obtained with the E10 blend. This behaviour is because the E40 mixture provides the appropriate amount of the oxygen for the combustion process, which leads to better utilization of available energy in this process, thus generating a comparable power output to the E10 mixing and producing lower emissions CO and HC with the other test blends. Nevertheless, the emission of NOx increases in 106.25 %.

Keywords: emissions, ethanol, gasoline, engine, performance

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4047 Regional Hydrological Extremes Frequency Analysis Based on Statistical and Hydrological Models

Authors: Hadush Kidane Meresa

Abstract:

The hydrological extremes frequency analysis is the foundation for the hydraulic engineering design, flood protection, drought management and water resources management and planning to utilize the available water resource to meet the desired objectives of different organizations and sectors in a country. This spatial variation of the statistical characteristics of the extreme flood and drought events are key practice for regional flood and drought analysis and mitigation management. For different hydro-climate of the regions, where the data set is short, scarcity, poor quality and insufficient, the regionalization methods are applied to transfer at-site data to a region. This study aims in regional high and low flow frequency analysis for Poland River Basins. Due to high frequent occurring of hydrological extremes in the region and rapid water resources development in this basin have caused serious concerns over the flood and drought magnitude and frequencies of the river in Poland. The magnitude and frequency result of high and low flows in the basin is needed for flood and drought planning, management and protection at present and future. Hydrological homogeneous high and low flow regions are formed by the cluster analysis of site characteristics, using the hierarchical and C- mean clustering and PCA method. Statistical tests for regional homogeneity are utilized, by Discordancy and Heterogeneity measure tests. In compliance with results of the tests, the region river basin has been divided into ten homogeneous regions. In this study, frequency analysis of high and low flows using AM for high flow and 7-day minimum low flow series is conducted using six statistical distributions. The use of L-moment and LL-moment method showed a homogeneous region over entire province with Generalized logistic (GLOG), Generalized extreme value (GEV), Pearson type III (P-III), Generalized Pareto (GPAR), Weibull (WEI) and Power (PR) distributions as the regional drought and flood frequency distributions. The 95% percentile and Flow duration curves of 1, 7, 10, 30 days have been plotted for 10 stations. However, the cluster analysis performed two regions in west and east of the province where L-moment and LL-moment method demonstrated the homogeneity of the regions and GLOG and Pearson Type III (PIII) distributions as regional frequency distributions for each region, respectively. The spatial variation and regional frequency distribution of flood and drought characteristics for 10 best catchment from the whole region was selected and beside the main variable (streamflow: high and low) we used variables which are more related to physiographic and drainage characteristics for identify and delineate homogeneous pools and to derive best regression models for ungauged sites. Those are mean annual rainfall, seasonal flow, average slope, NDVI, aspect, flow length, flow direction, maximum soil moisture, elevation, and drainage order. The regional high-flow or low-flow relationship among one streamflow characteristics with (AM or 7-day mean annual low flows) some basin characteristics is developed using Generalized Linear Mixed Model (GLMM) and Generalized Least Square (GLS) regression model, providing a simple and effective method for estimation of flood and drought of desired return periods for ungauged catchments.

Keywords: flood , drought, frequency, magnitude, regionalization, stochastic, ungauged, Poland

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4046 Stress Concentration and Strength Prediction of Carbon/Epoxy Composites

Authors: Emre Ozaslan, Bulent Acar, Mehmet Ali Guler

Abstract:

Unidirectional composites are very popular structural materials used in aerospace, marine, energy and automotive industries thanks to their superior material properties. However, the mechanical behavior of composite materials is more complicated than isotropic materials because of their anisotropic nature. Also, a stress concentration availability on the structure, like a hole, makes the problem further complicated. Therefore, enormous number of tests require to understand the mechanical behavior and strength of composites which contain stress concentration. Accurate finite element analysis and analytical models enable to understand mechanical behavior and predict the strength of composites without enormous number of tests which cost serious time and money. In this study, unidirectional Carbon/Epoxy composite specimens with central circular hole were investigated in terms of stress concentration factor and strength prediction. The composite specimens which had different specimen wide (W) to hole diameter (D) ratio were tested to investigate the effect of hole size on the stress concentration and strength. Also, specimens which had same specimen wide to hole diameter ratio, but varied sizes were tested to investigate the size effect. Finite element analysis was performed to determine stress concentration factor for all specimen configurations. For quasi-isotropic laminate, it was found that the stress concentration factor increased approximately %15 with decreasing of W/D ratio from 6 to 3. Point stress criteria (PSC), inherent flaw method and progressive failure analysis were compared in terms of predicting the strength of specimens. All methods could predict the strength of specimens with maximum %8 error. PSC was better than other methods for high values of W/D ratio, however, inherent flaw method was successful for low values of W/D. Also, it is seen that increasing by 4 times of the W/D ratio rises the failure strength of composite specimen as %62.4. For constant W/D ratio specimens, all the strength prediction methods were more successful for smaller size specimens than larger ones. Increasing the specimen width and hole diameter together by 2 times reduces the specimen failure strength as %13.2.

Keywords: failure, strength, stress concentration, unidirectional composites

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4045 Simon Says: What Should I Study?

Authors: Fonteyne Lot

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SIMON (Study capacities and Interest Monitor is a freely accessible online self-assessment tool that allows secondary education pupils to evaluate their interests and capacities in order to choose a post-secondary major that maximally suits their potential. The tool consists of two broad domains that correspond with two general questions pupils ask: 'What study fields interest me?' and 'Am I capable to succeed in this field of study?'. The first question is addressed by a RIASEC-type interest inventory that links personal interests to post-secondary majors. Pupils are provided with a personal profile and an overview of majors with their degree of congruence. The output is dynamic: respondents can manipulate their score and they can compare their results to the profile of all fields of study. That way they are stimulated to explore the broad range of majors. To answer whether pupils are capable of succeeding in a preferred major, a battery of tests is provided. This battery comprises a range of factors that are predictive of academic success. Traditional predictors such as (educational) background and cognitive variables (mathematical and verbal skills) are included. Moreover, non-cognitive predictors of academic success (such as 'motivation', 'test anxiety', 'academic self-efficacy' and 'study skills') are assessed. These non-cognitive factors are generally not included in admission decisions although research shows they are incrementally predictive of success and are less discriminating. These tests inform pupils on potential causes of success and failure. More important, pupils receive their personal chances of success per major. These differential probabilities are validated through the underlying research on academic success of students. For example, the research has shown that we can identify 22 % of the failing students in psychology and educational sciences. In this group, our prediction is 95% accurate. SIMON leads more students to a suitable major which in turn alleviates student success and retention. Apart from these benefits, the instrument grants insight into risk factors of academic failure. It also supports and fosters the development of evidence-based remedial interventions and therefore gives way to a more efficient use of means.

Keywords: academic success, online self-assessment, student retention, vocational choice

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4044 The Strategies to Improve the Pedestrian System in the Context of Old Aging

Authors: Yuxiao Jiang, Dong Ma, Mengyu Zhan, Yingxia Yun

Abstract:

China now is entering the phase of old aging and the aging speed is on acceleration. The proportion of the aged citizens in the urban areas is getting larger. Traveling on foot is one of the main travel methods for the old, but the bad walking environment and unsystematic pedestrian system cause inconvenience to the old who travel on foot. The paper analyzes the behavioral characteristics and the spatial preferences of the elderly group as well as the new traffic demands of them, finding out that some problems exist in the current pedestrian system. Thus, the paper proposes strategies in the areas of planning and design, and engineering technology so as to promote the traffic environment and perfect the pedestrian system for the old people.

Keywords: old aging, pedestrian system, perfection strategies, travel characteristics, future demand

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4043 Disconnect between Water, Sanitation and Hygiene Related Behaviours of Children in School and Family

Authors: Rehan Mohammad

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Background: Improved Water, Sanitation and Hygiene (WASH) practices in schools ensure children’s health, well-being and cognitive performance. In India under various WASH interventions in schools, teachers, and other staff make every possible effort to educate children about personal hygiene, sanitation practices and harms of open defecation. However, once children get back to their families, they see other practicing inappropriate WASH behaviors, and they consequently start following them. This show disconnect between school behavior and family behavior, which needs to be bridged to achieve desired WASH outcomes. Aims and Objectives: The aim of this study is to assess the factors causing disconnect of WASH-related behaviors between school and the family of children. It also suggests behavior change interventions to bridge the gap. Methodology: The present study has chosen a mixed- method approach. Both quantitative and qualitative methods of data collection have been used in the present study. The purposive sampling for data collection has been chosen. The data have been collected from 20% children in each age group of 04-08 years and 09-12 years spread over three primary schools and 20% of households to which they belong to which is spread over three slum communities in south district of Delhi. Results: The present study shows that despite of several behavior change interventions at school level, children still practice inappropriate WASH behaviors due to disconnect between school and family behaviors. These behaviors show variation from one age group to another. The inappropriate WASH behaviors being practiced by children include open defecation, wrong disposal of garbage, not keeping personal hygiene, not practicing hand washing practices during critical junctures and not washing fruits and vegetables before eating. The present study has highlighted that 80% of children in the age group of 04-08 years still practice inappropriate WASH behaviors when they go back to their families after school whereas, this percentage has reduced to 40% in case of children in the age group 09-12 years. Present study uncovers association between school and family teaching which creates a huge gap between WASH-related behavioral practices. The study has established that children learn and de-learn the WASH behaviors due to the evident disconnect between behavior change interventions at schools and household level. The study has also made it clear that children understand the significance of appropriate WASH practices but owing to the disconnect the behaviors remain unsettled. The study proposes several behavior change interventions to sync the behaviors of children at school and family level to ensure children’s health, well-being and cognitive performance.

Keywords: behavioral interventions, child health, family behavior, school behavior, WASH

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4042 Approximation of the Time Series by Fractal Brownian Motion

Authors: Valeria Bondarenko

Abstract:

In this paper, we propose two problems related to fractal Brownian motion. First problem is simultaneous estimation of two parameters, Hurst exponent and the volatility, that describe this random process. Numerical tests for the simulated fBm provided an efficient method. Second problem is approximation of the increments of the observed time series by a power function by increments from the fractional Brownian motion. Approximation and estimation are shown on the example of real data, daily deposit interest rates.

Keywords: fractional Brownian motion, Gausssian processes, approximation, time series, estimation of properties of the model

Procedia PDF Downloads 355