Search results for: strain rate effect

Authors: He Li Wen, Meng Qing Xiang, Li De Yong, Zhang Ya Wei, Ren Li Ping

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Stress always exerts some extent adverse effects on the animal production, food safety and quality concerns. Stress is commonly-seen in livestock industry, but there is rare literature focusing on the effects of nutrition stress. What’s more, the research always concentrates on the effect of single stress additionally, there is scarce information about the stress effect on waterfowl like goose as they are commonly thought to be tolerant to stress. To our knowledge, it is not always true. The object of this study was to evaluate the response of growing Greylag geese offered different fiber sources to the comprehensive stress, primarily involving the procedures of fasting, transport, capture, etc. The birds were randomly selected to rear with the diets differing in fiber source, being corn straw silage (CSS), steam-exploded corn straw (SECS), steam-exploded wheat straw (SEWS), and steam-exploded rice straw (SERS), respectively. Blood samples designated for the determination of stress status were collected before (pre-stress ) and after (post-stress ) the stressors carried out. No difference (P>0.05) was found on the pre-stress blood parameters of growing Greylags fed alternative fiber sources. Irrespective of the dietary differences, the comprehensive stress decreased (P<0.01) the concentration of SOD and increased (P<0.01) that of CK. Between the dietary treatments, the birds fed CSS had a higher (P<0.05)post-stress concentration of MDA than those offered SECS, along with a similarity to those fed the other two fiber sources. There was no difference (P>0.05) found on the stress response of the birds fed different fiber sources. In conclusion, SOD and CK concentration in blood may be more sensitive in indicating stress status and dietary fiber source exerted no effect on the stress response of growing Greylags. There is little chance to improve the stress status by ingesting different fiber sources.

Keywords: blood parameter, fiber source, Greylag goose, stress

Procedia PDF Downloads 521

Authors: Tamar Khardziani, Violeta Berikashvili, Amrosi Chkuaseli, Vladimir Elisashvili

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The main objectives of this proposal are to develop low-cost, innovative, and competitive technologies for the production of mycelial biomass of medicinal mushrooms as a natural food supplement for poultry. To fulfill this task, industrial strains of Lentinus edodes, Ganoderma lucidum, and Pleurotus ostreatus were used in this study. The solid-state fermentation (SSF) of wheat grains, wheat bran, and soy flour was performed in flasks and bags. Among nine mushroom strains, P. ostreatus 2191 appeared to be the most productive in protein biomass accumulation in the SSF of wheat bran. All mushrooms produced exopolysaccharide with the highest yield of 5-8 mg/mL depending on fungal strain and growth substrate. Supplementation of medium with 1% glycerol and 2-4% peptone favored mushroom growth and protein accumulation. Among inorganic nitrogen sources, KNO₃ also provided high biomass and protein production. The SSF of all growth substrates was accompanied by the secretion of cellulase and xylanase activities. The highest CMCase activity (12-13 U/g) was revealed in the cultivation of P. ostreatus 2191 using wheat bran as a growth substrate and ammonium sulfate or yeast extract as a nitrogen source, whereas the highest xylanase activity was detected in the fermentation of soy flour supplemented with peptone. Acknowledgments: This work was supported by the Shota Rustaveli National Science Foundation of Georgia (Grant number STEM-22-2077).

Keywords: mushrooms, plant raw materials, fermentation, biomass protein, cellulase

Procedia PDF Downloads 82

Authors: Hussein Bizimana, Osman Sönmez

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Constructed wetlands are current the most widely recognized waste water treatment option, especially in developing countries where they have the potential for improving water quality and creating valuable wildlife habitat in ecosystem with treatment requirement relatively simple for operation and maintenance cost. Lack of grey waste water treatment facilities in Kigali İnstitute of Science and Technology in Rwanda, causes pollution in the surrounding localities of Rugunga sector, where already a problem of poor sanitation is found. In order to treat grey water produced at Kigali İnstitute of Science and Technology, with high BOD concentration, high nutrients concentration and high alkalinity; a Horizontal Sub-surface Flow pilot-scale constructed wetland was designed and can operate in Kigali İnstitute of Science and Technology. The study was carried out in a sedimentation tank of 5.5 m x 1.42 m x 1.2 m deep and a Horizontal Sub-surface constructed wetland of 4.5 m x 2.5 m x 1.42 m deep. The grey waste water flow rate of 2.5 m3/d flew through vegetated wetland and sandy pilot plant. The filter media consisted of 0.6 to 2 mm of coarse sand, 0.00003472 m/s of hydraulic conductivity and cattails (Typha latifolia spp) were used as plants species. The effluent flow rate of the plant is designed to be 1.5 m3/ day and the retention time will be 24 hrs. 72% to 79% of BOD, COD, and TSS removals are estimated to be achieved, while the nutrients (Nitrogen and Phosphate) removal is estimated to be in the range of 34% to 53%. Every effluent characteristic will meet exactly the Rwanda Utility Regulatory Agency guidelines primarily because the retention time allowed is enough to make the reduction of contaminants within effluent raw waste water. Treated water reuse system was developed where water will be used in the campus irrigation system again.

Keywords: constructed wetlands, hydraulic conductivity, grey waste water, cattails

Procedia PDF Downloads 611

Authors: Toyosi Yewande Tunde-Akintunde, Grace Oluwatoyin Ogunlakin, Bosede Folake Olanipekun

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Peppers are excellent sources of nutrients but its high moisture content makes it susceptible to spoilage. Drying, a common processing method, results in a reduction of these nutrients in the final product. Pre-treatment of pepper before drying can be used to reduce the level of degradation of nutrients. Thus this study investigated the effect of pre-treatment (hot water blanching and soaking in brine-sodium chloride) and drying methods (oven, microwave and sun) on selected quality parameters (proximate composition, capsaicin, reducing sugar and phenolic content, pH, total solid (TS), Titratable acidity (TA), water absorption capacity (WAC) and colour) of pepper. The protein and moisture content value ranged from 9.09 to 10.23% and 5.63 to 8.48% respectively. Sun dried samples had the highest value while oven dried samples had the lowest. Brine treated samples had higher protein but lower moisture content than blanched samples. Capsaicin, reducing sugar and phenolic content values ranged from 0.68 to 0.87 mg/dm3; 3.18 to 3.79 µg/ml; and 40.67 to 84.01 mg GAE/100 g d.m respectively. The sun dried samples had higher values while the lowest values were from microwave dried samples. The brine treated samples had higher values in capsaicin while the blanched samples had higher reducing sugar and phenolic contents. The values of L, a* and b* for the dried pepper varied from 58.76 to 63.13; 7.09 to 7.34; and 11.79 to 12.36 respectively. Oven dried samples had the lowest values for a*, while its L values were the highest. The L and a* values for brine treated samples were higher than blanched samples. The pre-treatment and drying method considered resulted in different values of the quality parameters considered which indicates that drying and pre-treatment has an effect on the quality of the final dried pepper samples.

Keywords: Bell pepper, microwave drying, oven drying, quality, sun drying

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Authors: Sheela Tiwari, R. Naresh, R. Jha

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The paper presents an investigation into the effect of neural network predictive control of UPFC on the transient stability performance of a multi-machine power system. The proposed controller consists of a neural network model of the test system. This model is used to predict the future control inputs using the damped Gauss-Newton method which employs ‘backtracking’ as the line search method for step selection. The benchmark 2 area, 4 machine system that mimics the behavior of large power systems is taken as the test system for the study and is subjected to three phase short circuit faults at different locations over a wide range of operating conditions. The simulation results clearly establish the robustness of the proposed controller to the fault location, an increase in the critical clearing time for the circuit breakers and an improved damping of the power oscillations as compared to the conventional PI controller.

Keywords: identification, neural networks, predictive control, transient stability, UPFC

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Authors: Nermin Mahmoud Gohar, Aisha Tarek Noour

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Learner satisfaction has been a vital field of interest in the literature. Accordingly, the paper will explore the reasons behind individual differences in motivation and satisfaction. This study examines the effect of both; Herzberg’s and Maslow’s theories on learners satisfaction. A self-administered questionnaire was used to collect data from learners who were geographically widely spread around the College of Maritime Transport and Technology (CMTT) at the Arab Academy for Science, Technology and Maritime Transport (AAST&MT) in Egypt. One hundred and fifty undergraduates responded to a questionnaire survey. Respondents were drawn from two branches in Alexandria and Port Said. The data analysis used was SPSS 22 and AMOS 18. Factor analysis technique was used to find out the dimensions under study verified by Herzberg’s and Maslow’s theories. In addition, regression analysis and structural equation modeling were applied to find the effect of the above-mentioned theories on maritime transport learners’ satisfaction. Concerning the limitation of this study, it used the available number of learners in the CMTT due to the relatively low population in this field.

Keywords: motivation, satisfaction, needs, education, Herzberg’s and Maslow’s theories

Procedia PDF Downloads 438

Authors: Seyed Hamed Hashemi Sohi, Gerald Jo Denoga

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Machining or metal cutting is one of the most widely used production processes in industry. The quality of the process and the resulting machined product depends on parameters like tool geometry, material, and cutting conditions. However, the relationships of these parameters to the cutting process are often based mostly on empirical knowledge. In this study, computer modeling and simulation using LS-DYNA software and a Smoothed Particle Hydrodynamic (SPH) methodology, was performed on the orthogonal metal cutting process to analyze three-dimensional deformation of AISI 1045 medium carbon steel during machining. The simulation was performed using the following constitutive models: the Power Law model, the Johnson-Cook model, and the Zerilli-Armstrong models (Z-A). The outcomes were compared against the simulated results obtained by Cenk Kiliçaslan using the Finite Element Method (FEM) and the empirical results of Jaspers and Filice. The analysis shows that the SPH method combined with the Zerilli-Armstrong constitutive model is a viable alternative to simulating the metal cutting process. The tangential force was overestimated by 7%, and the normal force was underestimated by 16% when compared with empirical values. The simulation values for flow stress versus strain at various temperatures were also validated against empirical values. The SPH method using the Z-A model has also proven to be robust against issues of time-scaling. Experimental work was also done to investigate the effects of friction, rake angle and tool tip radius on the simulation.

Keywords: metal cutting, smoothed particle hydrodynamics, constitutive models, experimental, cutting forces analyses

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Authors: Manendra Singh Parihar, Sandip Ghosh Chowdhury

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Austenitic stainless steels are widely used and give a good combination of properties. When this steel is plastically deformed, a phase transformation of the metastable Face Centred Cubic Austenite to the stable Body Centred Cubic (α’) or to the Hexagonal close packed (ԑ) martensite may occur, leading to the enhancement in the mechanical properties like strength. The work was based on variant selection and corresponding texture analysis for the strain induced martensitic transformation during deformation of the parent austenite FCC phase to form the product HCP and the BCC martensite phases separately, obeying their respective orientation relationships. The automated method for reconstruction of the parent phase orientation using the EBSD data of the product phase orientation is done using the MATLAB and TSL-OIM software. The method of triplets was used which involves the formation of a triplet of neighboring product grains having a common variant and linking them using a misorientation-based criterion. This led to the proper reconstruction of the pre-transformation phase orientation data and thus to its microstructure and texture. The computational speed of current method is better compared to the previously used methods of reconstruction. The reconstruction of austenite from ԑ and α’ martensite was carried out for multiple samples and their IPF images, pole figures, inverse pole figures and ODFs were compared. Similar type of results was observed for all samples. The comparison gives the idea for estimating the correct sequence of the transformation i.e. γ → ε → α’ or γ → α’, during deformation of AISI 304 austenitic stainless steel.

Keywords: variant selection, reconstruction, EBSD, austenitic stainless steel, martensitic transformation

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Authors: Ammar Asma, Bouafia Nabiha, Ben Cheikh Asma, Ezzi Olfa, Mahjoub Mohamed, Sma Nesrine, Chouchène Imed, Boussarsar Hamadi, Njah Mansour

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Background: Ventilator-associated pneumonia (VAP) is currently recognized as one of the most relevant causes of morbidity and mortality among intensive care unit (ICU) patients worldwide. Identifying modifiable risk factors for VAP could be helpful for future controlled interventional studies aiming at improving prevention of VAP. The purposes of this study were to determine the incidence and risk factors for VAP in in a Tunisian medical ICU. Materials / Methods: A retrospective case-control study design based on the prospective database collected over a 14-month period from September 15th, 2015 through November 15th, 2016 in an 8-bed medical ICU. Patients under ventilation for over 48 h were included. The number of cases was estimated by Epi-info Software with the power of statistical test equal to 90 %. Each case patient was successfully matched to two controls according to the length of mechanical ventilation (MV) before VAP for cases and the total length of MV in controls. VAP in the ICU was defined according to American Thoracic Society; Infectious Diseases Society of America guidelines. Early onset or late-onset VAP were defined whether the infectious process occurred within or after 96 h of ICU admission. Patients’ risk factors, causes of admission, comorbidities and respiratory specimens collected were reviewed. Univariate and multivariate analyses were performed to determine variables associated with VAP with a p-value < 0.05. Results: During the period study, a total of 169 patients under mechanical ventilation were considered, 34 patients (20.11%) developed at least one episode of VAP in the ICU. The incidence rate for VAP was 14.88/1000 ventilation days. Among these cases, 9 (26.5 %) were early-onset VAP and 25 (73.5 %) were late-onset VAP. It was a certain diagnosis in 66.7% of cases. Tracheal aspiration was positive in 80% of cases. Multi-drug resistant Acinerobacter baumanii was the most common species detected in cases; 67.64% (n=23). The rate of mortality out of cases was 88.23% (n= 30). In univariate analysis, the patients with VAP were statistically more likely to suffer from cardiovascular diseases (p=0.035) and prolonged duration of sedation (p=0.009) and tracheostomy (p=0.001), they also had a higher number of re-intubation (p=0.017) and a longer total time of intubation (p=0.012). Multivariate analysis showed that cardiovascular diseases (OR= 4.44; 95% IC= [1.3 - 14]; p=0.016), tracheostomy (OR= 4.2; 95% IC= [1.16 -15.12]; p= 0.028) and prolonged duration of sedation (OR=1.21; 95% IC= [1.07, 1.36]; p=0.002) were independent risk factors for the development of VAP. Conclusion: VAP constitutes a therapeutic challenge in an ICU setting, therefore; strategies that effectively prevent VAP are needed. An infection control-training program intended to all professional heath care in this unit insisting on bundles and elaboration of procedures are planned to reduce effectively incidence rate of VAP.

Keywords: case control study, intensive care unit, risk factors, ventilator associated pneumonia

Procedia PDF Downloads 396

Authors: Eui Jun Jeong, Hye Rim Lee, Ji Hye Yoo

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Recent studies have verified the significant relationship of user personality with Internet use. However, in game studies, little research has emphasized on the effects of personality traits on game addiction. This study examined whether big five personality traits affect game addiction with control of psychological, social, and demographic factors. Specifically, using data from a survey of 789 game users in Korea, we conducted a regression analysis to see the associations of psychological (loneliness/depression), social (activities with family/friends), self-efficacy (game/general), gaming (daily gaming time/perception), demographic (age/gender), and personality traits (extraversion, neuroticism conscientiousness, agreeableness, & openness) with the degree of game addiction. Results showed that neuroticism increase game addiction with no effect of extraversion on the addiction. General self-efficacy negatively affected game addiction, whereas game self-efficacy increased the degree of game addiction. Loneliness enhanced game addiction while depression showed a negative effect on the addiction. Results and implications are discussed.

Keywords: game addiction, big five personality, social activities, self-efficacy, loneliness, depression

Procedia PDF Downloads 571

Authors: Shivahari Revathi Venkateswaran

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Segmenting customers plays a significant role in churn prediction. It helps the marketing team with proactive and reactive customer retention. For the reactive retention, the retention team reaches out to customers who already showed intent to disconnect by giving some special offers. When coming to proactive retention, the marketing team uses churn prediction model, which ranks each customer from rank 1 to 100, where 1 being more risk to churn/disconnect (high ranks have high propensity to churn). The churn prediction model is built by using XGBoost model. However, with the churn rank, the marketing team can only reach out to the customers based on their individual ranks. To profile different groups of customers and to frame different marketing strategies for targeted groups of customers are not possible with the churn ranks. For this, the customers must be grouped in different segments based on their profiles, like demographics and other non-controllable attributes. This helps the marketing team to frame different offer groups for the targeted audience and prevent them from disconnecting (proactive retention). For segmentation, machine learning approaches like k-mean clustering will not form unique customer segments that have customers with same attributes. This paper finds an alternate approach to find all the combination of unique segments that can be formed from the user attributes and then finds the segments who have uplift (churn rate higher than the baseline churn rate). For this, search algorithms like fast search and recursive search are used. Further, for each segment, all customers can be targeted using individual churn ranks from the churn prediction model. Finally, a UI (User Interface) is developed for the marketing team to interactively search for the meaningful segments that are formed and target the right set of audience for future marketing campaigns and prevent them from disconnecting.

Keywords: churn prediction modeling, XGBoost model, uplift segments, proactive marketing, search algorithms, retention, k-mean clustering

Procedia PDF Downloads 73

Authors: Seyed Abolhasan Naeini, Saeideh Mohammadi

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Rapid urban development leads to the construction of urban tunnels for transport. Passage of tunnels under the surface structures and utilities prompted the changes in the site conditions and hence alteration of the dynamic response of surface structures. Therefore, in this study, the effect of the interaction of tunnel-superstructure on the site response is investigated numerically. For this purpose, Fast Lagrangian Analysis of Continua (FLAC 2D) is used, and stratification and properties of soil layers are selected based on the line No 7 of Tehran subway. The superstructure is modeled both as an equivalent surcharge and the actual structure, and the results are compared. A comparison of the results shows that consideration of structure geometry is necessary for dynamic analysis and it leads to the changes in displacements and accelerations. Consequently, the geometry of the superstructure should be modeled completely instead of the application of an equivalent load. The effect of tunnel diameter and depth on the settlement of superstructures is also studied. Results show that when the tunnel depth and diameter grow, the settlements increase considerably.

Keywords: tunnel, FLAC2D, settlement, dynamic analysis

Procedia PDF Downloads 134

Authors: Boualem Mekimah, Abderraouf Messai, Abdelkrim Belhedri

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Dielectric substrates have an important attention in the fabrication of microstrip patch antennas. The effects of the uniaxial anisotropy and the loss tangent on resonant frequencies of microstrip patches consist of two perfectly conducting rectangular patches in stacked and offset configuration, embedded in a bilayer medium containing isotropic or uniaxial anisotropic materials. The Green’s functions are discussed in detail and numerical results are validated by comparing the computed results with previously published data. The numerical results show, that the uniaxial anisotropy has more effects on resonant frequencies according to the optical axis. However, the loss tangent of dielectric substrates has almost no effect on resonant frequencies, but it strongly affects the imaginary parts of the resonant frequencies of the antenna. The dielectric constant has no effect on the separation in terms of frequencies.

Keywords: resonant frequencies, loss tangent, microstrip patches, stacked, anisotropic materials, optical axis

Procedia PDF Downloads 436

Authors: Vu Hoang Thu Huong

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Background and Purpose: The effects of Extracorporeal Shockwave Therapy (ESWT) in the participants with knee osteoarthritis (KOA) were unclear on physical performance although its effects on pain had been investiagted. This study aims to explore the effects of ESWT on pain relief and physical performance on KOA. Methods: The studies with the randomized controlled design to investigate the effects of ESWT on KOA were systematically searched using inclusion and exclusion criteria through seven electronic databases including Pubmed etc. between 1990 and Dec 2022. To summarize those data, visual analog scale (VAS) or pain scores were determined for measure of pain intensity. Range of knee motion, or the scores of physical activities including Lequesne index (LI), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were determined for measure of physical performances. The first evaluate after treatment period was define as the effect of post-treatment period or immediately effect; and the last evaluate was defined as the effect of following period or the end effect in our study. Data analysis was performed using RevMan 5.4.1 software. A significant level was set at p<0.05. Results: Eight studies (number of participant= 499) reporting the ESWT effects on mild-to-moderate severity (Grades I to III Kellgren–Lawrence) of KOA were qualified for meta-analysis. Compared with sham or placebo group, the ESWT group had a significant decrease of VAS rest score (0.90[0.12~1.67] as mean difference [95% confidence interval]) and pain score WOMAC (2.49[1.22~3.76]), and a significant improvement of physical performance with a decrease of the scores of WOMAC activities (8.18[3.97~12.39]), LI (3.47[1.68~5.26]), and KOOS (5.87[1.73~ 10.00]) in the post-treatment period. There were also a significant decrease of WOMAC pain score (2.83[2.12~3.53]) and a significant decrease of the scores of WOMAC activities (9.47[7.65~11.28]) and LI (4.12[2.34 to 5.89]) in the following period. Besides, compared with other treatment groups, ESWT also displayed the improvement in pain and physical performance, but it is not significant. Conclusions: The ESWT was effective and valuable method in pain relief as well as in improving physical activities in the participants with mild-to-moderate KOA. Clinical Relevance: There are the effects of ESWT on pain relief and the improvement of physical performance in the with KOA.

Keywords: knee osteoarthritis, extracorporeal shockwave therapy, pain relief, physical performance, shockwave

Procedia PDF Downloads 89

Authors: Y. Melis, E. Apicella, E. Dozio, L. Mendolicchio

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Introduction: Feeding and Eating Disorders (FED) represent the psychiatric pathology with the highest mortality rate and one of the major disorders with the highest psychiatric and clinical comorbidity. The vagus nerve represents one of the main components of the sympathetic and parasympathetic nervous system and is involved in important neurophysiological functions. In FED, there is a spectrum of symptoms which with TaVNS (Transcutaneous Auricular Vagus Nerve Stimulation) therapy, is possible to have a therapeutic efficacy. Materials and Methods: Sample subjects are composed of 15 female subjects aged > 18 ± 51. Admitted to a psychiatry community having been diagnosed according to DSM-5: anorexia nervosa (AN) (N= 9), bulimia nervosa (BN) (N= 5), binge eating disorder (BED) (N= 1). The protocol included 9 weeks of Ta-VNS stimulation at a frequency of 1.5-3.5 mA for 4 hours per day. The variables detected are the following: Heart Rate Variability (HRV), Hamilton Depression Rating Scale (HAMD-HDRS-17), Body Mass Index (BMI), Beck Anxiety Index (BAI). Results: Data analysis showed statistically significant differences between recording times (p > 0.05) in HAM-D (t0 = 18.28 ± 5.31; t4 = 9.14 ± 7.15), in BAI (t0 = 24.7 ± 10.99; t4 = 13.8 ± 7.0). The reported values show how during (T0-T4) the treatment there is a decay of the degree in the depressive state, in the state of anxiety, and an improvement in the value of BMI. In particular, the BMI in the AN-BN sub-sample had a minimum gain of 5% and a maximum of 11%. The analysis of HRV did not show a clear change among subjects, thus confirming the discordance of the activity of the sympathetic and parasympathetic nervous system in FED. Conclusions: Although the sample does not possess a relevant value to determine long-term efficacy of Ta-VNS or on a larger population, this study reports how the application of neuro-stimulation in FED may become a further approach therapeutic. Indeed, substantial improvements are highlighted in the results and confirmed hypotheses proposed by the study.

Keywords: feeding and eating disorders, neurostimulation, anxiety disorders, depression

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Authors: Tauhidur Rahman, Gitartha Kalita

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In this study a four span box girder bridge is considered and effect of the rotational and translational earthquake ground motion have been thoroughly investigated. This study is motivated by the fact that in many countries the translational and rotational components of earthquake ground motion, especially rocking, is not adequately considered in analysing the overall response of the structures subjected to earthquake ground excitations. Much consideration is given to only the horizontal components of the earthquake ground motion during the response analysis of structures. In the present research work, P waves, SV waves and Rayleigh wave excitations are considered for different angle of incidence. In the present paper, the four span bridge is model considering the effects of vertical and rocking components of P, SV and Rayleigh wave excitations. Ground responses namely displacement, velocity and acceleration of the substructures of the bridge have been considered for rotational and translational effects in addition to the horizontal ground motion due to earthquake and wind.

Keywords: ground motion, response, rotational effects, translational effects

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Authors: Mohieddine Benghersallah, Mohamed Zakaria Zahaf, Ali Medjber, Idriss Tibakh

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The objective of this study is to analyse the effects of cutting parameters on surface roughness in dry face milling using statistical techniques. We studied the effect of the microstructure of AISI 52100 steel on machinability before and after hardening. The machining tests were carried out on a high rigidity vertical milling machine with a 25 mm diameter face milling cutter equipped with micro-grain bicarbide inserts with PVD (Ti, AlN) coating in GC1030 grade. A Taguchi L9 experiment plan is adopted. Analysis of variance (ANOVA) was used to determine the effects of cutting parameters (Vc, fz, ap) on the roughness (Ra) of the machined surface. Regression analysis to assess the machinability of steel presented mathematical models of roughness and the combination of parameters to minimize it. The recorded results show that feed per tooth has the most significant effect on the surface condition for both steel treatment conditions. The best roughnesses were obtained for the hardened AISI 52100 steel.

Keywords: machinability, heat treatment, microstructure, surface roughness, Taguchi method

Procedia PDF Downloads 151

Authors: Syahrul Bariah Abdul Hamid, Colin W. Binns, Jun Hui Chih

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The total of obese mothers is growing throughout Asia. Breastfeeding provides the perfect nutrition for infants, by promoting a higher IQ and protecting against childhood and adult diseases. A prospective cohort study was carried out of mothers attending eight antenatal clinics run by the Ministry of Health in Selangor, Malaysia to document the prevalence of obesity and its relationship with breastfeeding outcomes. Mothers were enrolled during the antenatal period and followed up until 6 months postpartum to document breastfeeding outcomes. A total of 652 Malay mothers were recruited for the study a response rate of 93.1 %. The pre-pregnancy body mass index (BMI) of the mothers showed that 36.5% of the mothers were overweight or obese. There were a total of 78 obese mothers in the sample and 41 (52.6%) of these mothers were able to initiate breastfeeding within one hour of birth compared to 238/337 (70.6 %, χ² 9.35, p<0.001) of those with a normal BMI. At 6 months, 23.1 % of obese mothers were exclusively breastfeeding their infants, compared to 56.0 % of the normal BMI mothers. On the other hand, the rate of infant formula feeding was higher in the obese mothers by 53.8 % compared to 19.0 % among normal weight mothers, χ² 37.6, p<0.001). Further analysis suggested these factors were found to be positively associated with discontinued exclusive breastfeeding at 6 months among obese mothers; mothers whom delayed breastfeeding initiation, had health problems during pregnancy, caesarean delivery, reported had insufficient colostrum/milk and babies had sucking problems at or before 4 weeks. Besides that, mothers who perceived their biological mothers had preference towards formula feeding or were ambivalent about the feeding method and had biological mothers without experience in breastfeeding for more than 1 month also were more likely to discontinue exclusive breastfeeding at 6 months. These findings suggested that the greater the pre-pregnant BMI, the earlier the cessation of exclusive breastfeeding and they were also less likely to initiate breastfeeding and have less adequate milk supply. Future investigations of the effects of maternal obesity on breastfeeding outcomes should be conducted along with effective interventions to advance the care of obese women at reproductive age and their children.

Keywords: exclusive breastfeeding, body mass index (BMI), breastfeeding discontinuation, maternal obesity

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Authors: Khalil Khanafer

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This study emphasizes on analyzing the effect of flow conditions and the geometric variation of the microcantilever’s bluff body on the microcantilever detection capabilities within a fluidic device using a finite element fluid-structure interaction model. Such parameters include inlet velocity, flow direction, and height of the microcantilever’s supporting system within the fluidic cell. The transport equations are solved using a finite element formulation based on the Galerkin method of weighted residuals. For a flexible microcantilever, a fully coupled fluid-structure interaction (FSI) analysis is utilized and the fluid domain is described by an Arbitrary-Lagrangian–Eulerian (ALE) formulation that is fully coupled to the structure domain. The results of this study showed a profound effect on the magnitude and direction of the inlet velocity and the height of the bluff body on the deflection of the microcantilever. The vibration characteristics were also investigated in this study. This work paves the road for researchers to design efficient microcantilevers that display least errors in the measurements.

Keywords: fluidic cell, FSI, microcantilever, flow direction

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Authors: Jose Ruiz, Jose Velasquez, Holger Lovon

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Peruvian university buildings are critical structures for which very little research about its seismic vulnerability is available. This paper develops a probabilistic methodology that predicts seismic loss for university buildings with simulated fragility functions. Two university buildings located in the city of Cusco were analyzed. Fragility functions were developed considering seismic and structural parameters uncertainty. The fragility functions were generated with the Latin Hypercube technique, an improved Montecarlo-based method, which optimizes the sampling of structural parameters and provides at least 100 reliable samples for every level of seismic demand. Concrete compressive strength, maximum concrete strain and yield stress of the reinforcing steel were considered as the key structural parameters. The seismic demand is defined by synthetic records which are compatible with the elastic Peruvian design spectrum. Acceleration records are scaled based on the peak ground acceleration on rigid soil (PGA) which goes from 0.05g to 1.00g. A total of 2000 structural models were considered to account for both structural and seismic variability. These functions represent the overall building behavior because they give rational information regarding damage ratios for defined levels of seismic demand. The university buildings show an expected Mean Damage Factor of 8.80% and 19.05%, respectively, for the 0.22g-PGA scenario, which was amplified by the soil type coefficient and resulted in 0.26g-PGA. These ratios were computed considering a seismic demand related to 10% of probability of exceedance in 50 years which is a requirement in the Peruvian seismic code. These results show an acceptable seismic performance for both buildings.

Keywords: fragility functions, university buildings, loss assessment, Montecarlo simulation, latin hypercube

Procedia PDF Downloads 146

Authors: Shamim Ali

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Researchers and teachers have begun developing digital games and model environments for educational purpose; therefore this study examines the effect of a videos game on secondary school students’ language learning motivation. Secondly, it tries to find out the opportunities to develop a decision making process and simultaneously it analyzes the solutions for further implementation in educational setting. Participants were 30 male students randomly assigned to one of the following three treatments: 10 students were assigned to read the game’s story; 10 students were players, who played video game; and, and the last 10 students acted as watchers and observers, their duty was to watch their classmates play the digital video game. A language learning motivation scale was developed and it was given to the participants as a pre- and post-test. Results indicated a significant language learning motivation and the participants were quite motivated in the end. It is, thus, concluded that the use of video games can help enhance high school students’ language learning motivation. It was suggested that video games should be used as a complementary activity not as a replacement for textbook since excessive use of video games can divert the original purpose of learning.

Keywords: EFL, English as a Foreign Language, motivation, video games, EFL learners

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Authors: Mohammed H. Karim, Bestoon M. Faraj

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Introduction: This study aimed to compare the effectiveness of a Dynamic Navigation System (DNS) and a three-dimensional microscope in retrieving broken rotary NiTi files when using trepan burs and the extractor system. Materials and Methods: Thirty maxillary first bicuspids with sixty separate roots were split into two comparable groups based on a comprehensive Cone-Beam Computed Tomography (CBCT) analysis of the root length and curvature. After standardized access opening, glide paths, and patency attainment with the K file (sizes 10 and 15), the teeth were arranged on 3D models (three per quadrant, six per model). Subsequently, controlled-memory heat-treated NiTi rotary files (#25/0.04) were notched 4 mm from the tips and fractured at the apical third of the roots. The C-FR1 Endo file removal system was employed under both guidance to retrieve the fragments, and the success rate, canal aberration, treatment time and volumetric changes were measured. The statistical analysis was performed using IBM SPSS software at a significance level of 0.05. Results: The microscope-guided group had a higher success rate than the DNS guidance, but the difference was insignificant (p > 0.05). In addition, the microscope-guided drills resulted in a substantially lower proportion of canal aberration, required less time to retrieve the fragments and caused minimal change in the root canal volume (p < 0.05). Conclusion: Although dynamically guided trephining with the extractor can retrieve separated instruments, it is inferior to three-dimensional microscope guidance regarding treatment time, procedural errors, and volume change.

Keywords: separated instruments retrieval, dynamic navigation system, 3D video microscope, trephine burs, extractor

Procedia PDF Downloads 72

Authors: Saad Howladar, Mike Dennett

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At first harvest, results showed that salinity (tap water, 100 and 200 mM NaCl) induced a significant decrease in all growth parameters in both Yecora Rojo and Paragon cultivars. The greatest effect of salinity was a decrease in leaf area. The same tendency was observed with specific leaf area, and total fresh and dry weights and their components. Green leaf and tiller numbers were reduced by the same extent in both cultivars. The corresponding final harvest, all growth parameters also reduced with increased salinity. Yield and yield components were also reduced by salinity with similar effects in both cultivars. Chlorophyll fluorescence, expressed as Fv/Fm, and gas exchange parameters were decreased significantly with increase in salinity in both cultivars. In contrast, seed protein content was increased significantly with increase in salinity. Salicylic acid (SA) application induced no significant improvements in growth parameters and yield components.

Keywords: salinity, salicylic acid, growth, chlorophyll fluorescence, gas exchange, yield

Procedia PDF Downloads 425

Authors: Fazilet Özlem Çekiç, Seyda Yılmaz

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Salinity and drought are important environmental problems in the world and have negative effects on plant metabolism. Gamma-aminobutyric acid (GABA), four-carbon non-protein amino acid, is a significant component of the free amino acid pool. GABA is widely distributed in prokaryotic and eukaryotic organisms. Environmental stress factors increase GABA accumulation in plants. Our aim was to evaluate the effect of gibberellic acid (GA) on GABA metabolism system during drought and salt stress factors in Phaseolus vulgaris L. plants. GABA, Glutamate dehydrogenase (GDH) activity, chlorophyll, and lipid peroxidation (MDA) analyses were determined. According to our results we can suggest that GA play a role in GABA metabolism during salt and drought stresses in bean plants. Also GABA shunt is an important metabolic pathway and key signaling allowing to adapt to drought and salt stresses.

Keywords: gibberellic acid, GABA, Phaseolus vulgaris L., salinity, drought

Procedia PDF Downloads 424

Authors: Ying-Ming Su, Mei-Shu Huang

Abstract:

To mitigate the urban heat island effect has become a global issue facing the challenge of climate change. Through literature reviews, plant photosynthesis can reduce the carbon dioxide and mitigate the urban heat island effect relatively. Because there are not enough open space and park, green roof has become an important policy in Taiwan. We selected elementary school buildings in northern New Taipei City as research subjects since elementary school is asked priority to build green roof and important educational place to promote green roof concept. Testo 175-H1 recording device was used to record the temperature and humidity difference between roof surface and interior space below roof with and without green roof for the long-term. We also use questionnaire to investigate the awareness of comfort level of green roof and sensation of teachers and students of the elementary school. The results indicated the temperature of roof without greening was higher than that with greening about 2°C. But sometimes during noontime, the temperature of green roof was higher than that of non-green roof related to the character of the accumulation and dissipation of heat of greening probably. The temperature of interior space below green roof was normally lower than that without green roof about 1°C showed that green roof could lower the temperature. The humidity of the green roof was higher than the one without greening also indicated that green roof retained water better. Teachers liked to combine green roof concept in the curriculum, students wished all classes can take turns to maintain the green roof. Teachers and students that school had integrated green roof concept in the curriculum were more willing to participate in the maintenance work of green roof. Teachers and students who may access and touch the green roof can be more aware of the green roof benefit. We suggest architect to increase the accessibility and visibility of green roof, such as a part of the activity space. This idea can be a reference of the green roof curriculum design.

Keywords: comfort level, elementary school, green roof, heat island effect

Procedia PDF Downloads 416

Authors: Wan Noorul Hafilah Binti Wan Ariffin

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Dam safety management is the crucial infrastructure as dam failure has a catastrophic effect on the community. Dam safety management is the effective framework of key actions and activities for the dam owner to manage the safety of the dam for its entire life cycle. However, maintaining dam safety is a challenging task as there are changes in current dam states. These changes introduce new risks to the dam's safety, which had not been considered when the dam was designed. A new framework has to be developed to adapt to the changes in the dam risk and make the dams resilient. This study proposes a risk-based decision-making adaptation framework for dam safety management. The research focuses on climate change's impact on hydrological situations as it causes floods and damages the dam structure. The risk analysis framework is adopted to improve the dam management strategies. The proposed study encompasses four phases. To start with, measuring the effect by assessing the impact of climate change on embankment dam, the second phase is to analyze the potential embankment dam failures. The third is analyzing the different components of risks related to the dam and, finally, developing a robust decision-making framework.

Keywords: climate change, embankment dam, failure, risk-informed decision making

Procedia PDF Downloads 172

Authors: Maninder Singh

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The Chandigarh city is under the strain of exponential growth of car density across various neighborhood. The consumerist nature of society today is to be blamed for this menace because everyone wants to own and ride a car. Car manufacturers are busy selling two or more cars per household. The Regional Transport Offices are busy issuing as many licenses to new vehicles as they can in order to generate revenue in the form of Road Tax. The car traffic in the neighborhoods of Chandigarh has reached a tipping point. There needs to be a more empirical and sustainable model of cars per household, which should be based on specific parameters of livable neighborhoods. Sector 22 in Chandigarh is one of the first residential sectors to be established in the city. There is scope to think, reflect, and work out a method to know how many cars we need to sell our citizens before we lose the argument to traffic problems, parking problems, and road rage. This is where the true challenge of a planner or a designer of the city lies. Currently, in Chandigarh city, there are no clear visible answers to this problem. The way forward is to look at spatial mapping, planning, and design of car parking units to address the problem, rather than suggesting extreme measures of banning cars (short-term) or promoting plans for citywide transport (very long-term). This is a chance to resolve the problem with a pragmatic approach from a citizen’s perspective, instead of an orthodox development planner’s methodology. Since citizens are at the center of how the problem is to be addressed, acceptable solutions are more likely to emerge from the car and traffic problem as defined by the citizens. Thus, the idea and its implementation would be interesting in comparison to the known academic methodologies. The novel and innovative process would lead to a more acceptable and sustainable approach to the issue of number of car parks in the neighborhood of Chandigarh city.

Keywords: cars, Chandigarh, neighborhood, sustainable living, walkability

Procedia PDF Downloads 151

Authors: Jin-Uk Park

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Recently, the semiconductor industry is rapidly demanding complicated structures and mass production. From the point of view of mass production, the ETCH industry is concentrating on maintaining the ER (Etch rate) of the wafer edge constant regardless of changes over time. In this study, two major thermal factors affecting process were identified and controlled. First, the filler of the thermal pad was studied. Second, the significant difference of handling the thermal pad during PM was studied.

Keywords: etcher, thermal pad, wet cleaning, thermal conductivity

Procedia PDF Downloads 197

Authors: Abir Dey, Shams Noman

Abstract:

Introduction: Offshore Island is the remote and isolated area from the terrestrial mainland. They are deprived of their needs. The children from an offshore island are usually underserved in the case of health care because it is a remote area where the health care systems are quite poor compared to mainland. So, the proper information is required for appropriate planning to reduce underlying causes behind visual deprivation among the surviving children of the Offshore Island. Purpose: The purpose of this study was to determine ocular morbidities, knowledge, and barriers of eye care services among children in an Offshore Island. Methods: The study team visited, and all data were collected from different rural communities at Sandwip Upazila, Chittagong district for screening the children aged 5-16 years old by doing spot examination. The whole study was conducted in both qualitative and quantitative methods. To determine ocular status of children, examinations were done under skilled Ophthalmologists and Optometrists. A focus group discussion was held. The sample size was 490. It was a community based descriptive study and the sampling method was purposive sampling. Results: In total 490 children, about 56.90% were female and 43.10% were male. Among them 456 were school-going children (93.1%) and 34 were non-school going children (6.9%). In this study the most common ocular morbidity was Allergic Conjunctivitis (35.2%). Other mentionable ocular morbidities were Refractive error (27.7%), Blepharitis (13.8%), Meibomian Gland Dysfunction (7.5%), Strabismus (6.3%) and Amblyopia (6.3%). Most of the non-school going children were involved in different types of domestic work like farming, fishing, etc. About 90.04% children who had different ocular abnormalities could not attend to the doctor due to various reasons. Conclusions: The ocular morbidity was high in rate on the offshore island. Eye health care facility was also not well established there. Awareness should be raised about necessity of maintaining hygiene and eye healthcare among the island people. Timely intervention through available eye care facilities and management can reduce the ocular morbidity rate in that area.

Keywords: morbidities, screening, barriers, offshore island, knowledge

Procedia PDF Downloads 163

Authors: S. R. Nikhashemi, Laily Haj Paim, Ali Khatibi

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Structural Equation Modeling (SEM) was used to test a hypothesized model explaining Malaysian hypermarket customers’ perceptions of brand trust (BT), customer perceived value (CPV) and perceived service quality (PSQ) on building their brand loyalty (CBL) and generating positive word-of-mouth communication (WOM). Self-administered questionnaires were used to collect data from 374 Malaysian hypermarket customers from Mydin, Tesco, Aeon Big and Giant in Kuala Lumpur, a metropolitan city of Malaysia. The data strongly supported the model exhibiting that BT, CPV and PSQ are prerequisite factors in building customer brand loyalty, while PSQ has the strongest effect on prediction of customer brand loyalty compared to other factors. Besides, the present study suggests the effect of the aforementioned factors via customer brand loyalty strongly contributes to generate positive word of mouth communication.

Keywords: brand trust, perceived value, Perceived Service Quality, Brand loyalty, positive word of mouth communication

Procedia PDF Downloads 484