Search results for: project based learning
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 34441

Search results for: project based learning

7231 Mixed Matrix Membranes Based on [M₂(DOBDC)] (M = Mg, Co, Ni) and Polydimethylsiloxane for CO₂/N₂ Separation

Authors: Hyunuk Kim, Yang No Yun, Muhammad Sohail, Jong-Ho Moon, Young Cheol Park

Abstract:

Metal-organic frameworks (MOFs), which are emerging absorbents assembled from metal ions and organic ligands, have attracted attention for their permanent porosity and design of tunable pore size. These microporous materials showed interesting properties for CO₂ storage and separation. In particular, MOFs with high surface area and open metal sites showed the remarkable adsorption capacity and selectivity for CO₂. [Mg₂ (DOBDC)] (DOBDC = 2,5-dioxidobenzene-1,4-dicarboxylate) (MOF-74 or CPO-27) is a well-known absorbent showing an exceptionally high CO₂ sorption capacity at low partial pressure and room temperature. In this work, we synthesized [M₂(DOBDC)(DMF)₂] (M = Mg, Co, Ni) and determined their single-crystal structures by X-ray crystallography. The removal of coordinated guest molecules generates Lewis acidic sites and showed high CO₂ adsorption affinity. Both CO₂ adsorption capacity and surface area are much higher than reported values in literature. To fabricate MMMs, microcrystalline [M₂ (DOBDC)(DMF)₂] was synthesized by microwave reaction and dispersed in PDMS solution. The MMMs with a various amount of [M₂ (DOBDC)(DMF) ₂] in PDMS were fabricated by a solution casting method. [M₂ (DOBDC)(DMF)₂]@PDMS membrane showed higher CO2 permeability and CO₂/N₂ selectivity than those of PDMS. Therefore, we believe that MMMs combining polymer and MOFs provide new materials for CO₂ separation technology.

Keywords: metal-organic frameworks, mixed matrix membrane, CO2/N2 separation, polydimethylsiloxane (PDMS)

Procedia PDF Downloads 200
7230 Statistical Mechanical Approach in Modeling of Hybrid Solar Cells for Photovoltaic Applications

Authors: A. E. Kobryn

Abstract:

We present both descriptive and predictive modeling of structural properties of blends of PCBM or organic-inorganic hybrid perovskites of the type CH3NH3PbX3 (X=Cl, Br, I) with P3HT, P3BT or squaraine SQ2 dye sensitizer, including adsorption on TiO2 clusters having rutile (110) surface. In our study, we use a methodology that allows computing the microscopic structure of blends on the nanometer scale and getting insight on miscibility of its components at various thermodynamic conditions. The methodology is based on the integral equation theory of molecular liquids in the reference interaction site representation/model (RISM) and uses the universal force field. Input parameters for RISM, such as optimized molecular geometries and charge distribution of interaction sites, are derived with the use of the density functional theory methods. To compare the diffusivity of the PCBM in binary blends with P3HT and P3BT, respectively, the study is complemented with MD simulation. A very good agreement with experiment and the reports of alternative modeling or simulation is observed for PCBM in P3HT system. The performance of P3BT with perovskites, however, seems as expected. The calculated nanoscale morphologies of blends of P3HT, P3BT or SQ2 with perovskites, including adsorption on TiO2, are all new and serve as an instrument in rational design of organic/hybrid photovoltaics. They are used in collaboration with experts who actually make prototypes or devices for practical applications.

Keywords: multiscale theory and modeling, nanoscale morphology, organic-inorganic halide perovskites, three dimensional distribution

Procedia PDF Downloads 152
7229 Burnout Recognition for Call Center Agents by Using Skin Color Detection with Hand Poses

Authors: El Sayed A. Sharara, A. Tsuji, K. Terada

Abstract:

Call centers have been expanding and they have influence on activation in various markets increasingly. A call center’s work is known as one of the most demanding and stressful jobs. In this paper, we propose the fatigue detection system in order to detect burnout of call center agents in the case of a neck pain and upper back pain. Our proposed system is based on the computer vision technique combined skin color detection with the Viola-Jones object detector. To recognize the gesture of hand poses caused by stress sign, the YCbCr color space is used to detect the skin color region including face and hand poses around the area related to neck ache and upper back pain. A cascade of clarifiers by Viola-Jones is used for face recognition to extract from the skin color region. The detection of hand poses is given by the evaluation of neck pain and upper back pain by using skin color detection and face recognition method. The system performance is evaluated using two groups of dataset created in the laboratory to simulate call center environment. Our call center agent burnout detection system has been implemented by using a web camera and has been processed by MATLAB. From the experimental results, our system achieved 96.3% for upper back pain detection and 94.2% for neck pain detection.

Keywords: call center agents, fatigue, skin color detection, face recognition

Procedia PDF Downloads 292
7228 PathoPy2.0: Application of Fractal Geometry for Early Detection and Histopathological Analysis of Lung Cancer

Authors: Rhea Kapoor

Abstract:

Fractal dimension provides a way to characterize non-geometric shapes like those found in nature. The purpose of this research is to estimate Minkowski fractal dimension of human lung images for early detection of lung cancer. Lung cancer is the leading cause of death among all types of cancer and an early histopathological analysis will help reduce deaths primarily due to late diagnosis. A Python application program, PathoPy2.0, was developed for analyzing medical images in pixelated format and estimating Minkowski fractal dimension using a new box-counting algorithm that allows windowing of images for more accurate calculation in the suspected areas of cancerous growth. Benchmark geometric fractals were used to validate the accuracy of the program and changes in fractal dimension of lung images to indicate the presence of issues in the lung. The accuracy of the program for the benchmark examples was between 93-99% of known values of the fractal dimensions. Fractal dimension values were then calculated for lung images, from National Cancer Institute, taken over time to correctly detect the presence of cancerous growth. For example, as the fractal dimension for a given lung increased from 1.19 to 1.27 due to cancerous growth, it represents a significant change in fractal dimension which lies between 1 and 2 for 2-D images. Based on the results obtained on many lung test cases, it was concluded that fractal dimension of human lungs can be used to diagnose lung cancer early. The ideas behind PathoPy2.0 can also be applied to study patterns in the electrical activity of the human brain and DNA matching.

Keywords: fractals, histopathological analysis, image processing, lung cancer, Minkowski dimension

Procedia PDF Downloads 173
7227 Quality Parameters of Offset Printing Wastewater

Authors: Kiurski S. Jelena, Kecić S. Vesna, Aksentijević M. Snežana

Abstract:

Samples of tap and wastewater were collected in three offset printing facilities in Novi Sad, Serbia. Ten physicochemical parameters were analyzed within all collected samples: pH, conductivity, m - alkalinity, p - alkalinity, acidity, carbonate concentration, hydrogen carbonate concentration, active oxygen content, chloride concentration and total alkali content. All measurements were conducted using the standard analytical and instrumental methods. Comparing the obtained results for tap water and wastewater, a clear quality difference was noticeable, since all physicochemical parameters were significantly higher within wastewater samples. The study also involves the application of simple linear regression analysis on the obtained dataset. By using software package ORIGIN 5 the pH value was mutually correlated with other physicochemical parameters. Based on the obtained values of Pearson coefficient of determination a strong positive correlation between chloride concentration and pH (r = -0.943), as well as between acidity and pH (r = -0.855) was determined. In addition, statistically significant difference was obtained only between acidity and chloride concentration with pH values, since the values of parameter F (247.634 and 182.536) were higher than Fcritical (5.59). In this way, results of statistical analysis highlighted the most influential parameter of water contamination in offset printing, in the form of acidity and chloride concentration. The results showed that variable dependence could be represented by the general regression model: y = a0 + a1x+ k, which further resulted with matching graphic regressions.

Keywords: pollution, printing industry, simple linear regression analysis, wastewater

Procedia PDF Downloads 231
7226 A Bibliometric Analysis on Filter Bubble

Authors: Misbah Fatma, Anam Saiyeda

Abstract:

This analysis charts the introduction and expansion of research into the filter bubble phenomena over the last 10 years using a large dataset of academic publications. This bibliometric study demonstrates how interdisciplinary filter bubble research is. The identification of key authors and organizations leading the filter bubble study sheds information on collaborative networks and knowledge transfer. Relevant papers are organized based on themes including algorithmic bias, polarisation, social media, and ethical implications through a systematic examination of the literature. In order to shed light on how these patterns have changed over time, the study plots their historical history. The study also looks at how research is distributed globally, showing geographic patterns and discrepancies in scholarly output. The results of this bibliometric analysis let us fully comprehend the development and reach of filter bubble research. This study offers insights into the ongoing discussion surrounding information personalization and its implications for societal discourse, democratic participation, and the potential risks to an informed citizenry by exposing dominant themes, interdisciplinary collaborations, and geographic patterns. In order to solve the problems caused by filter bubbles and to advance a more diverse and inclusive information environment, this analysis is essential for scholars and researchers.

Keywords: bibliometric analysis, social media, social networking, algorithmic personalization, self-selection, content moderation policies and limited access to information, recommender system and polarization

Procedia PDF Downloads 113
7225 A Case Study of Clinicians’ Perceptions of Enterprise Content Management at Tygerberg Hospital

Authors: Temitope O. Tokosi

Abstract:

Healthcare is a human right. The sensitivity of health issues has necessitated the introduction of Enterprise Content Management (ECM) at district hospitals in the Western Cape Province of South Africa. The objective is understanding clinicians’ perception of ECM at their workplace. It is a descriptive case study design of constructivist paradigm. It employed a phenomenological data analysis method using a pattern matching deductive based analytical procedure. Purposive and s4nowball sampling techniques were applied in selecting participants. Clinicians expressed concerns and frustrations using ECM such as, non-integration with other hospital systems. Inadequate access points to ECM. Incorrect labelling of notes and bar-coding causes more time wasted in finding information. System features and/or functions (such as search and edit) are not possible. Hospital management and clinicians are not constantly interacting and discussing. Information turnaround time is unacceptably lengthy. Resolving these problems would involve a positive working relationship between hospital management and clinicians. In addition, prioritising the problems faced by clinicians in relation to relevance can ensure problem-solving in order to meet clinicians’ expectations and hospitals’ objective. Clinicians’ perception should invoke attention from hospital management with regards technology use. The study’s results can be generalised across clinician groupings exposed to ECM at various district hospitals because of professional and hospital homogeneity.

Keywords: clinician, electronic content management, hospital, perception, technology

Procedia PDF Downloads 231
7224 Chatter Prediction of Curved Thin-walled Parts Considering Variation of Dynamic Characteristics Based on Acoustic Signals Acquisition

Authors: Damous Mohamed, Zeroudi Nasredine

Abstract:

High-speed milling of thin-walled parts with complex curvilinear profiles often encounters machining instability, commonly referred to as chatter. This phenomenon arises due to the dynamic interaction between the cutting tool and the part, exacerbated by the part's low rigidity and varying dynamic characteristics along the tool path. This research presents a dynamic model specifically developed to predict machining stability for such curved thin-walled components. The model employs the semi-discretization method, segmenting the tool trajectory into small, straight elements to locally approximate the behavior of an inclined plane. Dynamic characteristics for each segment are extracted through experimental modal analysis and incorporated into the simulation model to generate global stability lobe diagrams. Validation of the model is conducted through cutting tests where acoustic intensity is measured to detect instabilities. The experimental data align closely with the predicted stability limits, confirming the model's accuracy and effectiveness. This work provides a comprehensive approach to enhancing machining stability predictions, thereby improving the efficiency and quality of high-speed milling operations for thin-walled parts.

Keywords: chatter, curved thin-walled part, semi-discretization method, stability lobe diagrams

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7223 Autonomy and Other Variables Related to the Expression of Love among Saudi Couples

Authors: Reshaa Alruwaili

Abstract:

The primary aim of this study was to examine the hypothesis presented by Self Determination theory which suggests that autonomy impacts positively the expression of love. Other hypotheses were also examined which suggest that other variables explain the expression of love, including: dyadic adjustment (dyadic consensus, dyadic satisfaction and dyadic cohesion), couple satisfaction, age, gender, the length of marriage, number of children and attachment styles. The participants were Saudi couples, which provided the opportunity to consider the influence of Saudi culture on the expression of love. A questionnaire was employed to obtain measures of all the relevant variables, including a measure of expression of love that was built from 27 items, constituting verbal, physical and caring features, and a measure of autonomy based on three features: authorship, interest-taking and susceptibility. Data were collected from both members of 34 Saudi couples. Descriptive analysis of both expression of love and autonomy was conducted. Correlation and regression were used to assess the relationships between expression of love and autonomy and other variables. Results indicated that Saudi couples who most often express their love tend to be more than somewhat autonomous. Not much difference was found between husbands and wives in expressing love, although wives were slightly more autonomous than husbands. Expression of love was enhanced by the autonomy of the participants to a greater extent when dyadic satisfaction was controlled, since the latter was negatively correlated with autonomy and had no effect on the expression of love. Basic psychological needs, dyadic consensus and dismissive-avoidant attachment improve the expression of love, while it is decreased by the number of children.

Keywords: autonomy, determination theory, expression of love, dyadic adjustment

Procedia PDF Downloads 228
7222 The Amount of Information Processing and Balance Performance in Children: The Dual-Task Paradigm

Authors: Chin-Chih Chiou, Tai-Yuan Su, Ti-Yu Chen, Wen-Yu Chiu, Chungyu Chen

Abstract:

The purpose of this study was to investigate the effect of reaction time (RT) or balance performance as the number of stimulus-response choices increases, the amount of information processing of 0-bit and 1-bit conditions based on Hick’s law, using the dual-task design. Eighteen children (age: 9.38 ± 0.27 years old) were recruited as the participants for this study, and asked to assess RT and balance performance separately and simultaneously as following five conditions: simple RT (0-bit decision), choice RT (1-bit decision), single balance control, balance control with simple RT, and balance control with choice RT. Biodex 950-300 balance system and You-Shang response timer were used to record and analyze the postural stability and information processing speed (RT) respectively for the participants. Repeated measures one-way ANOVA with HSD post-hoc test and 2 (balance) × 2 (amount of information processing) repeated measures two-way ANOVA were used to test the parameters of balance performance and RT (α = .05). The results showed the overall stability index in the 1-bit decision was lower than in 0-bit decision, and the mean deflection in the 1-bit decision was lower than in single balance performance. Simple RTs were faster than choice RTs both in single task condition and dual task condition. It indicated that the chronometric approach of RT could use to infer the attention requirement of the secondary task. However, this study did not find that the balance performance is interfered for children by the increasing of the amount of information processing.

Keywords: capacity theory, reaction time, Hick’s law, balance

Procedia PDF Downloads 446
7221 Mapping of Adrenal Gland Diseases Research in Middle East Countries: A Scientometric Analysis, 2007-2013

Authors: Zahra Emami, Mohammad Ebrahim Khamseh, Nahid Hashemi Madani, Iman Kermani

Abstract:

The aim of the study was to map scientific research on adrenal gland diseases in the Middle East countries through the Web of Science database using scientometric analysis. Data were analyzed with Excel software; and HistCite was used for mapping of the scientific texts. In this study, from a total of 268 retrieved records, 1125 authors from 328 institutions published their texts in 138 journals. Among 17 Middle East countries, Turkey ranked first with 164 documents (61.19%), Israel ranked second with 47 documents (15.53%) and Iran came in the third place with 26 documents. Most of the publications (185 documents, 69.2%) were articles. Among the universities of the Middle East, Istanbul University had the highest science production rate (9.7%). The Journal of Clinical Endocrinology & Metabolism had the highest TGCS (243 citations). In the scientific mapping, 7 clusters were formed based on TLCS (Total Local Citation Score) & TGCS (Total Global Citation Score). considering the study results, establishment of scientific connections and collaboration with other countries and use of publications on adrenal gland diseases from high ranking universities can help in the development of this field and promote the medical practice in this regard. Moreover, investigation of the formed clusters in relation to Congenital Hyperplasia and puberty related disorders can be research priorities for investigators.

Keywords: mapping, scientific research, adrenal gland diseases, scientometric

Procedia PDF Downloads 268
7220 The Genetic Basis of the Lack of Impulse Control: What is Provided for the Criminal Law?

Authors: Amir Bastani

Abstract:

The result of the research in the field of human behavioural genetics demonstrates a genetic contribution of behavioural differences in aggression, violence, drug and substance abuse, antisocial personality disorder and other related traits. As the field of human behavioural genetics progresses and achieves credibility, the criminal accused continue to use its types of evidence into the criminal law. One of the most important genetic factors which controls certain neurotransmitters like dopamine and serotonin is the Monoamine Oxidase Acid A (MAOA) gene, known as the 'warrior gene'. The high-profile study by Caspi and colleagues in 2002 showed that the combination between one type of variation of the MAOA gene and childhood maltreatment noticeably predisposes a person to antisocial behaviour. Moreover, further scientific research shows that individuals with the MAOA gene have to some degree difficulties in controlling their impulses. Based on the evidence of MAOA, some criminal accused claimed difficulties in self-control. In the first case – the famous case of Mobley – the court rejected the MAOA evidence on the ground of the lack of scientific support. In contrast, in other cases after the Mobley trial, courts accepted the evidence of MAOA. In this paper, the issue of lack of impulse control produced by the MAOA gene and cases which relied on the MAOA evidence and successfully being accepted will be reviewed in detail. Finally, the anticipation of the paper for the future use of the MAOA evidence in criminal cases will be presented.

Keywords: genetic defence, criminal responsibility, MAOA, self-control

Procedia PDF Downloads 468
7219 Effect of Early Therapeutic Intervention for the Children With Autism Spectrum Disorders: A Quasi Experimental Design

Authors: Sultana Razia

Abstract:

The number of children whose social, communication and behavior pattern is affected due to mental and developmental conditions is on the rise. Most of these conditions develop to uncontrollable levels because of ignorance and unaware about their child’s condition. The many myths surrounding mental or developmental conditions are a major cause of families of affected children to develop bitterness and to shy off from seeking appropriate help in time. Several early intervention programs have been put in place, and the number of beneficiaries of these programs is increasing by the day. This research seeks to look into early intervention programs and their effectiveness. The purpose of this study was to investigate the effect of early therapeutic intervention for the children with autism spectrum disorder. Participants were 140 children with autism spectrum disorder from Autism Corner in a selected rehabilitation center of Bangladesh. This study included children who are at age of 18-month to 36-month and who were taking occupational therapy and speech and language therapy from the autism center. They were primarily screened using M-CHAT; however, children with other physical disability or medical conditions excluded. 3-months interventions of 6 sessions per week are a minimum of 45-minutes long per session, one to one interaction followed by parent-led structured home-based therapy were provided. The results indicated that early intensive therapeutic intervention improve understanding, social skills and sensory skills. It can be concluded that therapeutic early intervention a positive effect on diminishing symptoms of Autism Spectrum Disorder.

Keywords: M-CHAT, ASD, sensory cheeklist, OT

Procedia PDF Downloads 67
7218 Comparative Syudy Of Heat Transfer Capacity Limits of Heat Pipe

Authors: H. Shokouhmand, A. Ghanami

Abstract:

Heat pipe is simple heat transfer device which combines the conduction and phase change phenomena to control the heat transfer without any need for external power source. At hot surface of heat pipe, the liquid phase absorbs heat and changes to vapor phase. The vapor phase flows to condenser region and with the loss of heat changes to liquid phase. Due to gravitational force the liquid phase flows to evaporator section.In HVAC systems the working fluid is chosen based on the operating temperature. The heat pipe has significant capability to reduce the humidity in HVAC systems. Each HVAC system which uses heater, humidifier or dryer is a suitable nominate for the utilization of heat pipes. Generally heat pipes have three main sections: condenser, adiabatic region and evaporator.Performance investigation and optimization of heat pipes operation in order to increase their efficiency is crucial. In present article, a parametric study is performed to improve the heat pipe performance. Therefore, the heat capacity of heat pipe with respect to geometrical and confining parameters is investigated. For the better observation of heat pipe operation in HVAC systems, a CFD simulation in Eulerian- Eulerian multiphase approach is also performed. The results show that heat pipe heat transfer capacity is higher for water as working fluid with the operating temperature of 340 K. It is also observed that the vertical orientation of heat pipe enhances it’s heat transfer capacity.

Keywords: heat pipe, HVAC system, grooved heat pipe, heat pipe limits

Procedia PDF Downloads 366
7217 Heat Pipe Thermal Performance Improvement in H-VAC Systems Using CFD Modeling

Authors: H. Shokouhmand, A. Ghanami

Abstract:

Heat pipe is a simple heat transfer device which combines the conduction and phase change phenomena to control the heat transfer without any need for external power source. At hot surface of the heat pipe, the liquid phase absorbs heat and changes to vapor phase. The vapor phase flows to condenser region and with the loss of heat changes to liquid phase. Due to gravitational force, the liquid phase flows to evaporator section. In HVAC systems, the working fluid is chosen based on the operating temperature. The heat pipe has significant capability to reduce the humidity in HVAC systems. Each HVAC system which uses heater, humidifier or dryer is a suitable nominate for the utilization of heat pipes. Generally, heat pipes have three main sections: condenser, adiabatic region, and evaporator.Performance investigation and optimization of heat pipes operation in order to increase their efficiency is crucial. In the present article, a parametric study is performed to improve the heat pipe performance. Therefore, the heat capacity of the heat pipe with respect to geometrical and confining parameters is investigated. For the better observation of heat pipe operation in HVAC systems, a CFD simulation in Eulerian- Eulerian multiphase approach is also performed. The results show that heat pipe heat transfer capacity is higher for water as working fluid with the operating temperature of 340 K. It is also showed that the vertical orientation of heat pipe enhances its heat transfer capacity.

Keywords: heat pipe, HVAC system, grooved heat pipe, CFD simulation

Procedia PDF Downloads 491
7216 Supersonic Flow around a Dihedral Airfoil: Modeling and Experimentation Investigation

Authors: A. Naamane, M. Hasnaoui

Abstract:

Numerical modeling of fluid flows, whether compressible or incompressible, laminar or turbulent presents a considerable contribution in the scientific and industrial fields. However, the development of an approximate model of a supersonic flow requires the introduction of specific and more precise techniques and methods. For this purpose, the object of this paper is modeling a supersonic flow of inviscid fluid around a dihedral airfoil. Based on the thin airfoils theory and the non-dimensional stationary Steichen equation of a two-dimensional supersonic flow in isentropic evolution, we obtained a solution for the downstream velocity potential of the oblique shock at the second order of relative thickness that characterizes a perturbation parameter. This result has been dealt with by the asymptotic analysis and characteristics method. In order to validate our model, the results are discussed in comparison with theoretical and experimental results. Indeed, firstly, the comparison of the results of our model has shown that they are quantitatively acceptable compared to the existing theoretical results. Finally, an experimental study was conducted using the AF300 supersonic wind tunnel. In this experiment, we have considered the incident upstream Mach number over a symmetrical dihedral airfoil wing. The comparison of the different Mach number downstream results of our model with those of the existing theoretical data (relative margin between 0.07% and 4%) and with experimental results (concordance for a deflection angle between 1° and 11°) support the validation of our model with accuracy.

Keywords: asymptotic modelling, dihedral airfoil, supersonic flow, supersonic wind tunnel

Procedia PDF Downloads 128
7215 Renal Transplant, Pregnancy, and Complications: A Literature Review

Authors: Sara Iqbal

Abstract:

Introduction:Renal transplant is increasingly one of the most popular transplants within the UK; with an aging population along with obesity epidemic we are witnessing increasing rates of diabetes – one of the commonest indications for renal transplant. However, the demand is far greater than supply. Many donors are provided by women of child-bearing age; however the long-term effects are still uncertain. Aim:Determine pregnancy outcomes and complications of women of child-bearing age following renal donation. Methods: A review of the current available literature was preformed using MEDLINE and EMBASE up to 2014. Search criteria included key terms such as pregnancy outcome post-renal donor, pregnancy outcomes and complications. Relevant articles were selected based on pure methodological medical research, after careful analysis, they were recorded within this review. Results: Out of 1141 women involved in transplant studies, 574 pregnancies reported having donated a single-renal donor prior to pregnancy. Of which a staggering miscarriage rate 32.4% (n=186) was reported, amongst this other complications included gestational hypertension of 10% (n=59) and gestational diabetes 2.3% (n=13). Other significantly noted complications included chronic hypertension, low-birth weights, and pregnancy-related death. Conclusions: After unilateral renal donor transplant, haemodynamics change along with pregnancy, predisposing women to developing several complications compared to pregnancies with no history any renal-donor transplant. Despite this, further investigation is required in order to accurately determine the safety of renal-donors in women of child-bearing age.

Keywords: renal transplant, pregnancy, complications, medical and health sciences

Procedia PDF Downloads 268
7214 Heat Pipes Thermal Performance Improvement in H-VAC Systems Using CFD Modeling

Authors: M. Heydari, A. Ghanami

Abstract:

Heat pipe is simple heat transfer device which combines the conduction and phase change phenomena to control the heat transfer without any need for external power source. At hot surface of heat pipe, the liquid phase absorbs heat and changes to vapor phase. The vapor phase flows to condenser region and with the loss of heat changes to liquid phase. Due to gravitational force the liquid phase flows to evaporator section.In HVAC systems the working fluid is chosen based on the operating temperature. The heat pipe has significant capability to reduce the humidity in HVAC systems. Each HVAC system which uses heater, humidifier or dryer is a suitable nominate for the utilization of heat pipes. Generally heat pipes have three main sections: condenser, adiabatic region and evaporator.Performance investigation and optimization of heat pipes operation in order to increase their efficiency is crucial. In present article, a parametric study is performed to improve the heat pipe performance. Therefore, the heat capacity of heat pipe with respect to geometrical and confining parameters is investigated. For the better observation of heat pipe operation in HVAC systems, a CFD simulation in Eulerian- Eulerian multiphase approach is also performed. The results show that heat pipe heat transfer capacity is higher for water as working fluid with the operating temperature of 340 K. It is also showed that the vertical orientation of heat pipe enhances it’s heat transfer capacity.

Keywords: heat pipe, HVAC system, grooved heat pipe, heat pipe limits

Procedia PDF Downloads 440
7213 Conversion of Glycerol to 3-Hydroxypropanoic Acid by Genetically Engineered Bacillus subtilis

Authors: Aida Kalantari, Boyang Ji, Tao Chen, Ivan Mijakovic

Abstract:

3-hydroxypropanoic acid (3-HP) is one of the most important biomass-derivable platform chemicals that can be converted into a number of industrially important compounds. There have been several attempts at production of 3-HP from renewable sources in cell factories, focusing mainly on Escherichia coli, Klebsiella pneumoniae, and Saccharomyces cerevisiae. Despite the significant progress made in this field, commercially exploitable large-scale production of 3-HP in microbial strains has still not been achieved. In this study, we investigated the potential of Bacillus subtilis to be used as a microbial platform for bioconversion of glycerol into 3-HP. Our recombinant B. subtilis strains overexpress the two-step heterologous pathway containing glycerol dehydratase and aldehyde dehydrogenase from various backgrounds. The recombinant strains harboring the codon-optimized synthetic pathway from K. pneumoniae produced low levels of 3-HP. Since the enzymes in the heterologous pathway are sensitive to oxygen, we had to perform our experiments in micro-aerobic conditions. Under these conditions, the cell produces lactate in order to regenerate NAD+, and we found the lactate production to be in competition with the production of 3-HP. Therefore, based on the in silico predictions, we knocked out the glycerol kinase (glpk), which in combination with growth on glucose, resulted in improving the 3-HP titer to 1 g/L and the removal of lactate. Cultivation of the same strain in an enriched medium improved the 3-HP titer up to 7.6 g/L. Our findings provide the first report of successful introduction of the biosynthetic pathway for conversion of glycerol into 3-HP in B. subtilis.

Keywords: bacillus subtilis, glycerol, 3-hydroxypropanoic acid, metabolic engineering

Procedia PDF Downloads 244
7212 Incidence of Cancer in Patients with Alzheimer's Disease: A 11-Year Nationwide Population-Based Study

Authors: Jun Hong Lee

Abstract:

Background: Alzheimer`s disease (AD) I: creases with age and is characterized by the premature progressive loss of neuronal cell. In contrast, cancer cells have inappropriate cell proliferation and resistance to cell death. Objective: We evaluated the association between cancer and AD and also examined the specific types of cancer. Patients and Methods/Material and Methods: This retrospective, nationwide, longitudinal study used National Health Insurance Service – Senior cohort (NHIS-Senior) 2002-2013, which was released by the KNHIS in 2016, comprising 550,000 random subjects who were selected from over than 60. The study included a cohort of 4,408 patients who were first diagnoses as AD between 2003 and 2005. To match each dementia patient, 19,150 subjects were selected from the database by Propensity Score Matching. Results: We enrolled 4,790 patients for analysis in this cohort and the prevalence of AD was higher in female (19.29%) than in male (17.71%). A higher prevalence of AD was observed in the 70-84 year age group and in the higher income status group. A total of 540 cancers occurred within the observation interval. Overall cancer was less frequent in those with AD (12.25%) than in the control (18.46%), with HR 0.704 (95% Confidence Intervals (CIs)=0.0.64-0.775, p-Value < 0.0001). Conclusion: Our data showed a decreased incidence of overall cancers in patients with AD similar to previous studies. Patients with AD had a significantly decreased risk of colon & rectum, lung and stomach cancer. This finding lower than but consistent with Western countries. We need further investigation of genetic evidence linking AD to cancer.

Keywords: Alzheimer, cancer, nationwide, longitudinal study

Procedia PDF Downloads 172
7211 The Impact of Board Director Characteristics on the Quality of Information Disclosure

Authors: Guo Jinhong

Abstract:

The purpose of this study is to explore the association between board member functions and information disclosure levels. Based on the literature variables, such as the characteristics of the board of directors in the past, a single comprehensive indicator is established as a substitute variable for board functions, and the information disclosure evaluation results published by the Securities and Foundation are used to measure the information disclosure level of the company. This study focuses on companies listed on the Taiwan Stock Exchange from 2006 to 2010 and uses descriptive statistical analysis, univariate analysis, correlation analysis and ordered normal probability (Ordered Probit) regression for empirical analysis. The empirical results show that there is a significant positive correlation between the function of board members and the level of information disclosure. This study also conducts a sensitivity test and draws similar conclusions, showing that boards with better board member functions have higher levels of information disclosure. In addition, this study also found that higher board independence, lower director shareholding pledge ratio, higher director shareholding ratio, and directors with rich professional knowledge and practical experience can help improve the level of information disclosure. The empirical results of this study provide strong support for the "relative regulations to improve the level of information disclosure" formulated by the competent authorities in recent years.

Keywords: function of board members, information disclosure, securities, foundation

Procedia PDF Downloads 93
7210 Determination of Lithology, Porosity and Water Saturation for Mishrif Carbonate Formation

Authors: F. S. Kadhim, A. Samsuri, H. Alwan

Abstract:

Well logging records can help to answer many questions from a wide range of special interested information and basic petrophysical properties to formation evaluation of oil and gas reservoirs. The accurate calculations of porosity in carbonate reservoirs are the most challenging aspects of well log analysis. Many equations have been developed over the years based on known physical principles or on empirically derived relationships, which are used to calculate porosity, estimate lithology and water saturation; however these parameters are calculated from well logs by using modern technique in a current study. Nasiriya (NS) oilfield is one of giant oilfields in the Middle East, and the formation under study is the Mishrif carbonate formation which is the shallowest hydrocarbon bearing zone in the NS oilfield. Neurolog software (V5, 2008) was used to digitize the scanned copies of the available logs. Environmental corrections had been made as per Schlumberger charts 2005, which supplied in the Interactive Petrophysics software (IP, V3.5, 2008). Three saturation models have been used to calculate water saturation of carbonate formations, which are simple Archie equation, Dual water model, and Indonesia model. Results indicate that the Mishrif formation consists mainly of limestone, some dolomite and shale. The porosity interpretation shows that the logging tools have a good quality after making the environmental corrections. The average formation water saturation for Mishrif formation is around 0.4-0.6.This study is provided accurate behavior of petrophysical properties with depth for this formation by using modern software.

Keywords: lithology, porosity, water saturation, carbonate formation, mishrif formation

Procedia PDF Downloads 370
7209 Contents for the Maintenance and Troubleshooting of Anti-lock Braking System for Automobile Craftsmen in Nigeria

Authors: Arah Abubakar Saidu, Audu Rufai, Abdulkadir Mohammed, Ibrahim Yakubu Umar, Idris Abubakar Mohammed

Abstract:

The study determined the contents for the maintenance and troubleshooting of an anti-lock braking system for automobile craftsmen in Nigeria. Two research questions were raised and answered and two null hypotheses were formulated and tested at a .05 level of significance. The study adopted a descriptive survey research design. The study was conducted in Federal Capital Territory (FCT), Abuja, Kaduna, Kano, Lagos and Plateau States, Nigeria. The targeted population for the study was 99 consisting of all 43 non-teaching Subject Matter Experts (SMEs). The study utilized the whole population of the study. The instruments used for data collection were Anti-lock Braking System Maintenance and Troubleshooting Contents Questionnaire (ABSMTQ). Mean was used to analyze data that answered research questions and Z-test was used in testing the null hypotheses. Findings revealed, among others, that 81 items as content for the maintenance of ABS and 61 items as content for troubleshooting ABS for automobile craftsmen in Nigeria. Based on the findings of the study, the recommended, among others, that the National Board for Technical Education should include the contents for the maintenance and troubleshooting ABS in Motor Vehicle Mechanic Works curriculum used for training automobile craftsmen through the process of curriculum review in order to equip them with the competencies in troubleshooting and maintenance of ABS.

Keywords: anti-lock braking system, maintenance, troubleshooting, automobile craftsmen

Procedia PDF Downloads 82
7208 The Rise of Boko Haram in Nigeria: Lesson for Ghana

Authors: Emmanuel Anim

Abstract:

Ghana has been touted as an oasis of peace in Africa following her relatively peaceful democratic elections, proliferated number of the media, and freedom of speech. Besides, the former Gold Coast country is yet to experience any major incidence of terrorism. Nevertheless, the somewhat occasional simmering violence and conflicts arising from political, religious and chieftaincy skirmishes, largely at its northern part portrays that it is not immune to the political violence of terrorism. The predominantly-based qualitative research reveals that current conditions of socio-politico-economic, and religious issues in Ghana places the West African country on the possible sidelines of the phenomenon of terrorism, when its status quo is juxtaposed with the factors enumerated to have culminated in the rise of Boko Haram, and its accompanying insurgency in Nigeria. Arguing from the perspective of the theory of Social Movement, the analyses and discussions note that the current state of affairs in Ghana could foster domestic terrorism in the country. What is more, the research shows that Ghana faces threats from transnational terrorism given the tendency for elements in Ghana to sympathize and subscribe to the ideological dictates and appeals from Boko Haram and other terrorist organizations. As a consequence, the study recommends that adverse conditions of poverty, poor governance, unemployment, and rising levels of (Islamic) religious radicalization should be remedied by economic improvements, good governance, job creation, and de-radicalization programs by government officials to aid mitigate the incidence of terrorism in the country.

Keywords: Boko Haram, Ghana, Nigeria, terrorism

Procedia PDF Downloads 418
7207 Gender Difference in Social Interaction Skills of Autism Using Token Economy and Video Modelling Strategies

Authors: Olusola Akintunde Adediran

Abstract:

This study examined differential effect of Gender difference in social interaction skill of pupils with autism using token economy and video modeling as intervention strategies. A pretest, posttest, control group, quasi-experimental research design was adopted in the study. 17 participants (11 males and 6 females) were selected purposively from 5 centres in Ibadan and randomized into three groups (token economy, video modeling and control groups). Two instruments were used in the study; Autism Spectrum Rating Scale (ASRS) for 299.00 Autistic Disorder (r = 0.82) and Children’s Self-report Social Skill Scale (CS4) (r= 0.93). A descriptive statistics was used to analyse the participants social interaction data based on intervention and gender, while inferential statistics of analysis of covariance (ANCOVA) and scheffe post-hoc measure was used to anlayse three null hypotheses tested at 0.05 level of significance. The results obtained indicated that there was a significant main effect of treatment on social interaction of participants, but there was no significant of main effect of gender on the social interaction of participants, hence, (F(2,14) = .741; p > .05, eta = .050). Lastly, there was no significant interaction effect of treatment and gender of the participants, hence (F(2,10) = 2.177; p > .05, eta 2 = 202). The study has contributed to the frontiers of knowledge by establishing that social interaction of autism is attainable when token economy and video modelling are used as treatment intervention, hence, they should be adopted by the teachers, curriculum planners and other stakeholders.

Keywords: social interaction, token economy, video modelling, autism, gender

Procedia PDF Downloads 135
7206 Relation of Cad/Cam Zirconia Dental Implant Abutments with Periodontal Health and Final Aesthetic Aspects; A Systematic Review

Authors: Amin Davoudi

Abstract:

Aim: New approaches have been introduced to improve soft tissue indices of the dental implants. This systematic review aimed to investigate the effect of computer-aided design and computer-assisted manufacture (CAD/CAM) zirconia (Zr) implant abutments on periodontal aspects. Materials and Methods: Five electronic databases were searched thoroughly based on prior defined MeSH and non-MeSH keywords. Clinical studies were collected via hand searches in English language journals up to September 2020. Interproximal papilla stability, papilla recession, pink and white esthetic score (PES, WES), bone and gingival margin levels, color, and contour of soft tissue were reviewed. Results: The initial literature search yielded 412 articles. After the evaluation of abstracts and full texts, six studies were eligible to be screened. The study design of the included studies was a prospective cohort (n=3) and randomized clinical trial (n=3). The outcome was found to be significantly better for Zr than titanium abutments, however, the studies did not show significant differences between stock and CAD/CAM abutments. Conclusion: Papilla fill, WES, PES, and the distance from the contact point to dental crest bone of adjacent tooth and inter-tooth–implant distance were not significantly different between Zr CAD/CAM and Zr stock abutments. However, soft tissue stability and recession index were better in Zr CAD/CAM abutments.

Keywords: zirconia, CADCAM, periodental, implant

Procedia PDF Downloads 99
7205 Optimization of Hepatitis B Surface Antigen Purifications to Improving the Production of Hepatitis B Vaccines on Pichia pastoris

Authors: Rizky Kusuma Cahyani

Abstract:

Hepatitis B is a liver inflammatory disease caused by hepatitis B virus (HBV). This infection can be prevented by vaccination which contains HBV surface protein (sHBsAg). However, vaccine supply is limited. Several attempts have been conducted to produce local sHBsAg. However, the purity degree and protein yield are still inadequate. Therefore optimization of HBsAg purification steps is required to obtain high yield with better purification fold. In this study, optimization of purification was done in 2 steps, precipitation using variation of NaCl concentration (0,3 M; 0,5 M; 0,7 M) and PEG (3%, 5%, 7%); ion exchange chromatography (IEC) using NaCl 300-500 mM elution buffer concentration.To determine HBsAg protein, bicinchoninic acid assay (BCA) and enzyme-linked immunosorbent assay (ELISA) was used in this study. Visualization of HBsAg protein was done by SDS-PAGE analysis. Based on quantitative analysis, optimal condition at precipitation step was given 0,3 M NaCl and PEG 3%, while in ion exchange chromatography step, the optimum condition when protein eluted with NaCl 500 mM. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis indicates that the presence of protein HBsAg with a molecular weight of 25 kDa (monomer) and 50 kDa (dimer). The optimum condition for purification of sHBsAg produced in Pichia pastoris gave a yield of 47% and purification fold 17x so that it would increase the production of hepatitis B vaccine to be more optimal.

Keywords: hepatitis B virus, HBsAg, hepatitis B surface antigen, Pichia pastoris, purification

Procedia PDF Downloads 148
7204 Navigating Urban Childcare Challenges: Perspectives of Dhaka City Parents

Authors: Md. Shafiullah

Abstract:

This study delves into the evolving landscape of urban childcare in Bangladesh, focusing on the experiences and challenges faced by parents in Dhaka city. This paper argues that the traditional childcare arrangement of city families is inadequate to meet the development needs of children. The study aims to explore the childcare challenges faced by urban parents as they transition from traditional family-based childcare networks to alternative caregiving arrangements amidst urbanization, economic shifts, and social transformations. Utilizing a mixed-method research approach, combining quantitative surveys (n = 200) and four qualitative interviews, the research examines the parental viewpoints on childcare practices and the role of societal norms and values. The study finds childcare crises in both the family and daycare settings. In family care, caregiving suffers from the less availability of grandparents, a lack of skills of caregivers, and a lack of child interaction. As for the daycare, it is affected by the absence of appropriate policies, a lack of quality, health and safety concerns, affordability issues, and cultural concerns. Additionally, the study highlights inadequacies in childcare policies and regulatory frameworks, calling for comprehensive reforms to address the childcare vacuum in urban areas. By shifting the focus from developed to developing countries, this study contributes to the literature and suggests policy implications for Bangladesh and beyond.

Keywords: childcare, child development, childcare policy, daycare, Bangladesh

Procedia PDF Downloads 53
7203 Geometric Morphometric Analysis of Allometric Variation in the Hand Morphology of Adults

Authors: Aleksandr S. Ermolenko

Abstract:

Allometry is an important factor of morphological integration, contributing to the organization of the phenotype and its variability. The allometric change in the shape of the hand is particularly important in primate evolution, as the hand has important taxonomic features. Some of these features are known to parts with the shape, especially the ratio of the lengths of the index and ring fingers (2d: 4d ratio). The hand is a fairly well-studied system in the context of the evolutionary development of complex morphological structures since it consists of various departments (basipodium, metapodium, acropodium) that form a single structure –autopodium. In the present study, we examined the allometric variability of acropodium. We tested the null hypothesis that there would be no difference in allometric variation between the two components. Geometric morphometry based on a procrustation of 16 two-dimensional (2D) landmarks was analyzed using multivariate shape-by-size regressions in samples from 100 people (50 men and 50 women). The results obtained show that men have significantly greater allometric variability for the ring finger (variability in the transverse axis prevails), while women have significantly greater allometric variability for the index finger (variability in the longitudinal axis prevails). The influence of the middle finger on the shape of the hand is typical for both men and women. The influence of the little finger on the shape of the hand, regardless of gender, was not revealed. The results of this study support the hypothesis that allometry contributes to the organization of variation in the human hand.

Keywords: human hand, size and shape, 2d:4d ratio, geometric morphometry

Procedia PDF Downloads 150
7202 The Semiotic Analysis of Thai Social Contexts in Thai Post’s News Articles

Authors: Pakpoom Hannapha

Abstract:

This paper investigates the implications of social and political contexts in Thai Post’s news articles written by a columnist, Khon Plai Soy. Samples included twenty eight news articles published between 28th May 2015 and 28th June 2015 selected and analyzed according to Semiotics including implications, connotation, cultural politics, and Thai usage in newspaper articles. The data analysis can be divided into two parts; first, an analysis of signs/signifiers appearing in the articles and second, an analysis of the columnist’s purposes. This study demonstrated representations of signs in the selected articles that were categorized into four groups: events, actions, persons, and organizations. In this study, implications of the news articles were analyzed in two aspects according to Semiotics. It was found that the columnist mostly points out purposes for education, facts, and personal opinions in his works. Also, he offers some solutions to problems discussed in the articles. The writer often explicated knowledge and facts in accordance with either his personal opinions or problem-solutions. According to the research result, studying the implications of news articles in the Thai Post based on the Semiotic approach can help clarify and understand connotative meanings in terms of contents and the writer’s purposes. This paper can enhance readers’ understanding of Semiotic implications through signs and meanings in the texts and thus be used as a model to explore other political news articles

Keywords: semiotic analysis, Thai social contexts, Thai Post’s news, articles

Procedia PDF Downloads 232