Search results for: Shahrul Azam Abdullah
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 542

Search results for: Shahrul Azam Abdullah

422 Dynamic Mechanical Thermal Properties of Arenga pinnata Fibre Reinforced Epoxy Composite: Effects of Alkaline Treatment

Authors: Abdul Hakim Abdullah, Mohamad Syafiq Abdul Khadir

Abstract:

In present investigations, thermal behaviours of Arenga pinnata fibres prior and after alkaline treatment were studied. The alkaline treatments were applied on the Arenga pinnata fibres by immersing in the alkaline solution, 6% sodium hydroxide (NaOH). Using hand lay-out technique, composites were fabricated at 20% and 40% by Arenga pinnata fibres weight contents. The thermal behaviours of both untreated and treated composites were determined by employing Dynamic Mechanical Analysis (DMA). The results show that the TAP owned better results of Storage Modulus (E’), Loss Modulus (E”) and Tan Delta temperatures ranges from 0°C to 60°C.

Keywords: composites, Arenga pinnata fibre, alkaline treatment, dynamic mechanical properties

Procedia PDF Downloads 332
421 Change Point Analysis in Average Ozone Layer Temperature Using Exponential Lomax Distribution

Authors: Amjad Abdullah, Amjad Yahya, Bushra Aljohani, Amani Alghamdi

Abstract:

Change point detection is an important part of data analysis. The presence of a change point refers to a significant change in the behavior of a time series. In this article, we examine the detection of multiple change points of parameters of the exponential Lomax distribution, which is broad and flexible compared with other distributions while fitting data. We used the Schwarz information criterion and binary segmentation to detect multiple change points in publicly available data on the average temperature in the ozone layer. The change points were successfully located.

Keywords: binary segmentation, change point, exponentialLomax distribution, information criterion

Procedia PDF Downloads 146
420 Active Learning: Increase Learning through Engagement

Authors: Jihan Albayati, Kim Abdullah

Abstract:

This poster focuses on the significance of active learning strategies and their usage in the ESL classroom. Active learning is a big shift from traditional lecturing to active student engagement which can enhance and enrich student learning; therefore, engaging students is the core of this approach. Students learn more when they participate in the process of learning such as discussions, debates, analysis, synthesis, or any form of activity that requires student involvement. In order to achieve active learning, teachers can use different instructional strategies that are conducive to learning and the selection of these strategies depends on student learning outcomes. Active learning techniques must be carefully designed and integrated into the classroom to increase critical thinking and student participation. This poster provides a concise definition of active learning and its importance, instructional strategies, active learning techniques and their impact on student engagement. Also, it demonstrates the differences between passive and active learners.

Keywords: active learning, learner engagement, student-centered, teaching strategies

Procedia PDF Downloads 451
419 Dividend Policy, Overconfidence and Moral Hazard

Authors: Richard Fairchild, Abdullah Al-Ghazali, Yilmaz Guney

Abstract:

This study analyses the relationship between managerial overconfidence, dividends, and firm value by developing theoretical models that examine the condition under which managerial overconfident, dividends, and firm value may be positive or negative. Furthermore, the models incorporate moral hazard, in terms of managerial effort shirking, and the potential for the manager to choose negative NPV projects, due to private benefits. Our models demonstrate that overconfidence can lead to higher dividends (when the manager is overconfident about his current ability) or lower dividends (when the manager is overconfident about his future ability). The models also demonstrate that higher overconfidence may result in an increase or a decrease in firm value. Numerical examples are illustrated for both models which interestingly support the models’ propositions.

Keywords: behavioural corporate finance, dividend policy, overconfidence, moral hazard

Procedia PDF Downloads 307
418 Numerical Study on Enhancement of Heat Transfer by Turbulence

Authors: Muhammad Azmain Abdullah, Ar Rashedul, Mohammad Ali

Abstract:

This paper scrutinizes the influences of turbulence on heat transport rate, Nusselt number. The subject matter of this investigation also deals with the improvement of heat transfer efficiency of the swirl flow obtained by rotating a twisted tape in a circular pipe. The conditions to be fulfilled to observe the impact of Reynolds number and rotational speed of twisted tape are: a uniform temperature on the outer surface of the pipe, the magnitude of velocity of water varying from 0.1 m/s to 0.7 m/s in order to alter Reynolds number and a rotational speed of 200 rpm to 600 rpm. The gyration of twisted tape increase by 17%. It is also observed that heat transfer is exactly proportional to inlet gauge pressure and reciprocally proportional to increase of twist ratio.

Keywords: swirl flow, twisted tape, twist ratio, heat transfer

Procedia PDF Downloads 239
417 Foodborne Disease Risk Factors Among Women in Riyadh, Saudi Arabia

Authors: Abdullah Alsayeqh

Abstract:

The burden of foodborne diseases in Saudi Arabia is currently unknown. The objective of this study was to identify risk factors associated with these diseases among women in Riyadh. A cross-sectional study was carried out from March to July, 2013 where participants’ responses indicated that they were at risk of these diseases through improper food-holding temperature (45.28%), inadequate cooking (35.47%), cross-contamination (32.23%), and food from unsafe sources (22.39%). The claimed food safety knowledge by 22.04% of participants was not evidenced by their reported behaviors (p > 0.05). This is the first study to identify the gap in food safety knowledge among women in Riyadh which needs to be addressed by the concerned authorities in the country by engaging women more effectively in food safety educational campaigns.

Keywords: foodborne diseases, risk factors, knowledge, women, Saudi Arabia

Procedia PDF Downloads 484
416 Baseline Data from Specialist Obesity Clinic in a Large Tertiary Care Facility, Karachi, Pakistan

Authors: Asma Ahmed, Farah Khalid, Sahlah Sohail, Saira Banusokwalla, Sabiha Banu, Inaara Akbar, Safia Awan, Syed Iqbal Azam

Abstract:

Background and Objectives: The level of knowledge regarding obesity as a disease condition and health-seeking behavior regarding its management is grossly lacking. We present data from our multidisciplinary obesity clinic at the large tertiary care facility in Karachi, Pakistan, to provide baseline profiles and outcomes of patients attending these clinics. Methods: 260 who attended the obesity clinic between June 2018 to March 2020 were enrolled in this study. The analysis included descriptive and ROC analysis to identify the best cut-offs of theanthropometric measurements to diagnose obesity-related comorbid conditions. Results: The majority of the studied population were women (72.3%) and employed(43.7%) with a mean age of 35.5 years. Mean BMIwas 37.4, waist circumference was 112.4 cm, visceral fat was 11.7%, and HbA1C was 6.9%. The most common comorbidities were HTN & D.M (33 &31%, respectively). The prevalence of MetS was 16.3% in patients and was slightly higher in males. Visceral fat was the main factor in predicting D.M (0.750; 95% CI: 0.665, 0.836) and MetS (0.709; 95% CI: 0.590, 0.838) compared to total body fat, waist circumference, and BMI. The risk of predicting DM &MetS for the visceral fat above 9.5% in women had the highest sensitivity (80% for D.M & 79% for MetS) and an NPV (92.75% for D.M & 95% for MetS). Conclusions: This study describes and establishes characteristics of these obese individuals, which can help inform clinical practices. These practices may involve using visceral fat for earlier identification and counseling-based interventions to prevent more severe surgical interventions down the line.

Keywords: obesity, metabolic syndrome, tertiary care facility, BMI, waist circumference, visceral fat

Procedia PDF Downloads 127
415 Modeling and Simulations of Surface Plasmon Waveguide Structures

Authors: Moussa Hamdan, Abdulati Abdullah

Abstract:

This paper presents an investigation of the fabrication of the optical devices in terms of their characteristics based on the use of the electromagnetic waves. Planar waveguides are used to examine the field modes (bound modes) and the parameters required for this structure. The modifications are conducted on surface plasmons based waveguides. Simple symmetric dielectric slab structure is used and analyzed in terms of transverse electric mode (TE-Mode) and transverse magnetic mode (TM-Mode. The paper presents mathematical and numerical solutions for solving simple symmetric plasmons and provides simulations of surface plasmons for field confinement. Asymmetric TM-mode calculations for dielectric surface plasmons are also provided.

Keywords: surface plasmons, optical waveguides, semiconductor lasers, refractive index, slab dialectical

Procedia PDF Downloads 277
414 Analyzing Electricity Demand Multipliers in the Malaysian Economy

Authors: Hussain Ali Bekhet, Tuan Ab Rashid Bin Tuan Abdullah, Tahira Yasmin

Abstract:

It is very important for electric utility to determine dominant sectors which have more impacts on electricity consumption in national economy system. The aim of this paper is to examine the electricity demand multipliers in Malaysia for (2005-2014) period. Malaysian Input-output tables, 2005 and 2010 are used. Besides, a new concept, electricity demand multiplier (EDM), is presented to identify key sectors imposing great impacts on electricity demand quantitatively. In order to testify the effectiveness of the Malaysian energy policies, it notes that there is fluctuation of the ranking sectors between 2005 and 2010. This could be reflected that there is efficiency with pace of development in Malaysia. This can be good indication for decision makers for designing future energy policies.

Keywords: input-output model, demand multipliers, electricity, key sectors, Malaysia

Procedia PDF Downloads 344
413 Towards an Understanding of Breaking and Coalescence Process in Bitumen Emulsions

Authors: Abdullah Khan, Per Redelius, Nicole Kringos

Abstract:

The breaking and coalescence process in bitumen emulsion strongly influence the performance of the cold mix asphalt (CMA) and this phase separation process is affected by the physio-chemical changes happening at the bitumen/water interface. In this paper, coalescence experiments of two bitumen droplets in an emulsion environment have been carried out by a newly developed test procedure. In this study, different types of emulsifiers were selected to understand the coalescence process with respect to changes in the water phase surface tension due to addition of different surfactants and other additives such as salts. The research showed that the relaxation kinetics of bitumen droplets varied with the type of emulsifier, its concentration as well as with and without presence of salt in the water phase. Moreover, kinetics of the coalescence process was also investigated with the temperature variation.

Keywords: bitumen emulsions, breaking and coalescence, cold mix asphalt, emulsifiers, relaxation, salts

Procedia PDF Downloads 310
412 Optimum Design of Attenuator of Spun-Bond Production System

Authors: Nasser Ghassembaglou, Abdullah Bolek, Oktay Yilmaz, Ertan Oznergiz, Hikmet Kocabas, Safak Yilmaz

Abstract:

Nanofibers are effective material which have frequently been investigated to produce high quality air filters. As an environmental approach our aim is to achieve nanofibers by melting. In spun-bond systems extruder, spin-pump, nozzle package and attenuator are used. Molten polymer which flows from extruder is made steady by spin-pump. Regular melt passes through nozzle holes and forms fibers under high pressure. The fibers pulled from nozzle are shrunk to micron size by an attenuator, after solidification they are collected on a conveyor. In this research different designs of attenuator system have been studied and also CFD analysis have been done on them. Afterwards, one of these designs tested and finally some optimizations have been done to reduce pressure loss and increase air velocity.

Keywords: attenuator, nanofiber, spun-bond, extruder

Procedia PDF Downloads 386
411 Influence of Thermal Processing Methods on Antinutrient of Artocarpus heterophyllus Seeds

Authors: Marina Zulkifli, Mohd Faizal Mashhod, Noriham Abdullah

Abstract:

The aim of this study was to determine the antinutrient compounds of jackfruit (Artocarpus heterophyllus) seeds as affected by thermal processes. Two types of heat treatments were applied namely boiling and microwave cooking. Results of this study showed that boiling caused a significant decrease in phytate content (30.01%), oxalate content (33.22%), saponin content (35.69%) and tannin content (44.58%) as compared to microwave cooking and raw seed. The percentage loss of antinutrient compounds in microwaved seed was: phytate 24.58%, oxalate 27.28%, saponin 16.50% and tannin 32.21%. Hence, these findings suggested that boiling is an effective treatment to reduce the level of toxic compounds in foods.

Keywords: jackfruit, heat treatments, antinutrient compounds, thermal processing

Procedia PDF Downloads 401
410 Synthesizing and Fabrication of Pani-(SnO₂, ZnO)/rGO by Sol-Gel Method to Develop a Biosensor Thin-Films on Top Glass Substrate

Authors: Mohammad Arifin, Huda Abdullah, Norshafadzila Mohammad Naim

Abstract:

The fabricated PANI-(SnO₂, ZnO)/rGO nanocomposite thin films for the E. coli bacteria sensor were investigated. The nanocomposite thin films were prepared by the sol-gel method and deposited on the glass substrate using the spin-coating technique. The internal structure and surface morphology of the thin films have been analyzed by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and atomic force microscopy (AFM). The optical properties of the films were investigated by UV-Vis spectroscopy, Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR). The sensitivity performance was identified by measuring the changing conductivity before and after the incubation of E. coli bacteria using current-voltage (I-V) and cyclic voltammetry (C-V) measurements.

Keywords: PANI-(SnO₂, ZnO)/rGO, nanocomposite, bacteria sensor, thin films

Procedia PDF Downloads 80
409 Robust Variable Selection Based on Schwarz Information Criterion for Linear Regression Models

Authors: Shokrya Saleh A. Alshqaq, Abdullah Ali H. Ahmadini

Abstract:

The Schwarz information criterion (SIC) is a popular tool for selecting the best variables in regression datasets. However, SIC is defined using an unbounded estimator, namely, the least-squares (LS), which is highly sensitive to outlying observations, especially bad leverage points. A method for robust variable selection based on SIC for linear regression models is thus needed. This study investigates the robustness properties of SIC by deriving its influence function and proposes a robust SIC based on the MM-estimation scale. The aim of this study is to produce a criterion that can effectively select accurate models in the presence of vertical outliers and high leverage points. The advantages of the proposed robust SIC is demonstrated through a simulation study and an analysis of a real dataset.

Keywords: influence function, robust variable selection, robust regression, Schwarz information criterion

Procedia PDF Downloads 114
408 The Association of Cone-Shaped Epiphysis and Poland Syndrome: A Case Report

Authors: Mohammad Alqattan, Tala Alkhunani, Reema Al, Aldawish, Felwa Almurshard, Abdullah Alzahrani

Abstract:

: Poland’s Syndrome is a congenital anomaly with two clinical features : unilateral agenesis of the pectoralis major and ipsilateral hand symbrachydactyly. Case presentation: We report a rare case of bilateral Poland’s syndrome with several unique features. Discussion: Poland’s syndrome is thought to be due to a vascular insult to the subclavian axis around the 6th week of gestation. Our patient has multiple rare and unique features of Poland’s syndrome. Conclusion: To our best knowledge, for the first time in the literature we associate Poland’s syndrome with cone-shaped epiphysis of the metacarpals of all fingers. Bilaterality, cleft hand deformity, and dextrocardia, were also rare features in our patient.

Keywords: Poland's syndrome, cleft hand deformity, bilaterality, dextrocardia, cone-shaped epiphysis

Procedia PDF Downloads 96
407 Operator Efficiency Study for Assembly Line Optimization at Semiconductor Assembly and Test

Authors: Rohana Abdullah, Md Nizam Abd Rahman, Seri Rahayu Kamat

Abstract:

Operator efficiency aspect is gaining importance in ensuring optimized usage of resources especially in the semi-automated manufacturing environment. This paper addresses a case study done to solve operator efficiency and line balancing issue at a semiconductor assembly and test manufacturing. A Man-to-Machine (M2M) work study technique is used to study operator current utilization and determine the optimum allocation of the operators to the machines. Critical factors such as operator activity, activity frequency and operator competency level are considered to gain insight on the parameters that affects the operator utilization. Equipment standard time and overall equipment efficiency (OEE) information are also gathered and analyzed to achieve a balanced and optimized production.

Keywords: operator efficiency, optimized production, line balancing, industrial and manufacturing engineering

Procedia PDF Downloads 699
406 Developing EFL Research Skills of Pre-Master Students through a Suggested Quest Based Learning Strategy

Authors: Heba Mustafa Abdullah

Abstract:

The research aimed at examining the effect of a using a quest based learning strategy on developing EFL Pre-Master Students. The study adopted the quasi-experimental design. The sample of the research consists of a group of 30 students enrolled in Pre-Master program, Curriculum and EFL Instruction Department, Faculty of Graduate Studies in Education Tools of the study included a EFL research skills checklist and EFL research skills test. Results revealed that there were statistically significant differences at 0.01 levels with regard to some research skills. Results were discussed in relation to several factors that affected the language learning process. Finally, the research provided beneficial contributions in relation to manipulating e-learning technologies in general and Quest based learning strategy in particular with respect to EFL research skills.

Keywords: English as foreign language, e-Learning, research skills, quest based learning

Procedia PDF Downloads 414
405 Literacy Performance among Lower Primary School Children : A Malaysian Case Study

Authors: Ratnawati Mohd Asraf, Hazlina Abdullah

Abstract:

Numerous studies on boys’ performance relative to girls’ have been conducted around the globe. However, little has been done in relation to the literacy of primary school boys in the Malaysian context. This paper discusses the results of a study that sought to determine the literacy performance of Grades 1, 2, and 3 primary school students in the state of Selangor, Malaysia. Data on approximately 85,000 students from each grade level were obtained from the Ministry of Education Malaysia, which conducts national screening on literacy and numeracy, or LINUS, in all government primary schools. Teachers’ views were also sought through focus group interviews and journal entries. The results show that although there is an overall improvement in literacy performance in the Malay language among the students as they go into Grades 2 and 3, girls are found to outperform boys in every screening for all grade levels.

Keywords: boys’ underperformance, literacy, literacy performance, reading

Procedia PDF Downloads 294
404 A Filtering Algorithm for a Nonlinear State-Space Model

Authors: Abdullah Eqal Al Mazrooei

Abstract:

Kalman filter is a famous algorithm that utilizes to estimate the state in the linear systems. It has numerous applications in technology and science. Since of the most of applications in real life can be described by nonlinear systems. So, Kalman filter does not work with the nonlinear systems because it is suitable to linear systems only. In this work, a nonlinear filtering algorithm is presented which is suitable to use with the special kinds of nonlinear systems. This filter generalizes the Kalman filter. This means that this filter also can be used for the linear systems. Our algorithm depends on a special linearization of the second degree. We introduced the nonlinear algorithm with a bilinear state-space model. A simulation example is presented to illustrate the efficiency of the algorithm.

Keywords: Kalman filter, filtering algorithm, nonlinear systems, state-space model

Procedia PDF Downloads 347
403 [Keynote Talk]: Evidence Fusion in Decision Making

Authors: Mohammad Abdullah-Al-Wadud

Abstract:

In the current era of automation and artificial intelligence, different systems have been increasingly keeping on depending on decision-making capabilities of machines. Such systems/applications may range from simple classifiers to sophisticated surveillance systems based on traditional sensors and related equipment which are becoming more common in the internet of things (IoT) paradigm. However, the available data for such problems are usually imprecise and incomplete, which leads to uncertainty in decisions made based on traditional probability-based classifiers. This requires a robust fusion framework to combine the available information sources with some degree of certainty. The theory of evidence can provide with such a method for combining evidence from different (may be unreliable) sources/observers. This talk will address the employment of the Dempster-Shafer Theory of evidence in some practical applications.

Keywords: decision making, dempster-shafer theory, evidence fusion, incomplete data, uncertainty

Procedia PDF Downloads 397
402 Novel Coprocessor for DNA Sequence Alignment in Resequencing Applications

Authors: Atef Ibrahim, Hamed Elsimary, Abdullah Aljumah, Fayez Gebali

Abstract:

This paper presents a novel semi-systolic array architecture for an optimized parallel sequence alignment algorithm. This architecture has the advantage that it can be modified to be reused for multiple pass processing in order to increase the number of processing elements that can be packed into a single FPGA and to increase the number of sequences that can be aligned in parallel in a single FPGA. This resolves the potential problem of many FPGA resources left unused for designs that have large values of short read length. When using the previously published conventional hardware design. FPGA implementation results show that, for large values of short read lengths (M>128), the proposed design has a slightly higher speed up and FPGA utilization over the the conventional one.

Keywords: bioinformatics, genome sequence alignment, re-sequencing applications, systolic array

Procedia PDF Downloads 495
401 Investigating Fatigue Life in Bolted Flange Connection in Wind Turbine Towers

Authors: Abdullah Salameh, Jamil Renno, Khaled Ali

Abstract:

This paper investigates how fatigue life is influenced by increasing the number and size of bolts under several wind speed averages. The study determined that increasing the size or number of bolts can notably improve the fatigue life of bolted flange connections. Additionally, the curves derived from the assessment data demonstrated a steeper slope for a greater number of bolts, indicating that the percentage increase of adding bolts is not consistent for each additional bolt. Instead, the percentage increment rises exponentially when increasing the number of bolts. However, selecting the most suitable design improvement strategy depends on the specific circumstances. In the majority of cases, the study observed that increasing the number of bolts resulted in significant improvements in fatigue life, regardless of the size of the bolts used.

Keywords: wind turbine tower, flanged connection, number of bolts, size of bolts, fatigue life

Procedia PDF Downloads 50
400 The Effect of Inlet Baffle Position in Improving the Efficiency of Oil and Water Gravity Separator Tanks

Authors: Haitham A. Hussein, Rozi Abdullah, Issa Saket, Md. Azlin

Abstract:

The gravitational effect has been extensively applied to separate oil from water in water and wastewater treatment systems. The maximum oil globules removal efficiency is improved by obtaining the best flow uniformity in separator tanks. This study used 2D computational fluid dynamics (CFD) to investigate the effect of different inlet baffle positions inside the separator tank. Laboratory experiment has been conducted, and the measured velocity fields which were by Nortek Acoustic Doppler Velocimeter (ADV) are used to verify the CFD model. Computational investigation results indicated that the construction of an inlet baffle in a suitable location provides the minimum recirculation zone volume, creates the best flow uniformity, and dissipates kinetic energy in the oil and water separator tank. Useful formulas were predicted to design the oil and water separator tanks geometry based on an experimental model.

Keywords: oil/water separator tanks, inlet baffles, CFD, VOF

Procedia PDF Downloads 326
399 Collaborative Research between Malaysian and Australian Universities on Learning Analytics: Challenges and Strategies

Authors: Z. Tasir, S. N. Kew, D. West, Z. Abdullah, D. Toohey

Abstract:

Research on Learning Analytics is progressively developing in the higher education field by concentrating on the process of students' learning. Therefore, a research project between Malaysian and Australian Universities was initiated in 2015 to look at the use of Learning Analytics to support the development of teaching practice. The focal point of this article is to discuss and share the experiences of Malaysian and Australian universities in the process of developing the collaborative research on Learning Analytics. Three aspects of this will be discussed: 1) Establishing an international research project and team members, 2) cross-cultural understandings, and 3) ways of working in relation to the practicalities of the project. This article is intended to benefit other researchers by highlighting the challenges as well as the strategies used in this project to ensure such collaborative research succeeds.

Keywords: academic research project, collaborative research, cross-cultural understanding, international research project

Procedia PDF Downloads 216
398 Social Sustainability Quotient of Vertical Habitats

Authors: Abdullah Mohamed, Raipat Vaidehi

Abstract:

With increasing immigration to urban areas, every city is experiencing shortage of housing. Vertical habitats are the only solution to this problem, it is hence important to make sure that these habitats are environmentally, socially and economically sustainable. A lot of work on vertical habitats has already been carried out in terms of environmental and economic sustainability, hence this research aims to study the aspects of social sustainability of the vertical habitats. It being the least studied topic, opens many reals of novelty and uniqueness. In this Research, user perception survey and various mapping methods have been used to study the social sustainability of the existing vertical habitats in the selected cities. The various aspects that can be used to define social sustainability of any place include; safety, equity, accessibility, legibility, imagibility, readability, memorability and ease of movement. This research would help to evolve new strategies in form of design and/or guidelines to make the existing vertical habitats socially sustainable.

Keywords: user lifestyle, user perception, social sustainability, vertical habitats

Procedia PDF Downloads 281
397 Fracture Toughness Properties and FTIR Analysis of Corn Fiber Green Composites

Authors: Ahmed Hashim, Aseel Abdullah

Abstract:

In this work, the fracture toughness of new green composite based on bio-PMMA resin reinforced with randomly short corn natural fiber of constant weight fraction by 10% wt was investigated. The corn fiber surface was modified by mercerization treatment with two different concentrations of sodium hydroxide (3, and 5% NaOH) for 1.5 and 3 hours respectively. The effect of mercerization treatment on the fracture behavior of the green composites was analyzed by FTIR spectra. NaOH concentration of 3% for 1.5 hrs. That was used for corn fiber green composite should the highest improvement in terms of plane strain fracture toughness KIC which increased by 62 % compared to untreated fiber composite material. On the other hand, increased both concentrations of alkali solution to 5% NaOH and time of soaking to 3 hrs. reduced the values of KIC lower than the value of the unfilled material.

Keywords: green composites, fracture toughness, corn natural fiber, bio-PMMA

Procedia PDF Downloads 395
396 Thermal Image Segmentation Method for Stratification of Freezing Temperatures

Authors: Azam Fazelpour, Saeed R. Dehghani, Vlastimil Masek, Yuri S. Muzychka

Abstract:

The study uses an image analysis technique employing thermal imaging to measure the percentage of areas with various temperatures on a freezing surface. An image segmentation method using threshold values is applied to a sequence of image recording the freezing process. The phenomenon is transient and temperatures vary fast to reach the freezing point and complete the freezing process. Freezing salt water is subjected to the salt rejection that makes the freezing point dynamic and dependent on the salinity at the phase interface. For a specific area of freezing, nucleation starts from one side and end to another side, which causes a dynamic and transient temperature in that area. Thermal cameras are able to reveal a difference in temperature due to their sensitivity to infrared radiance. Using Experimental setup, a video is recorded by a thermal camera to monitor radiance and temperatures during the freezing process. Image processing techniques are applied to all frames to detect and classify temperatures on the surface. Image processing segmentation method is used to find contours with same temperatures on the icing surface. Each segment is obtained using the temperature range appeared in the image and correspond pixel values in the image. Using the contours extracted from image and camera parameters, stratified areas with different temperatures are calculated. To observe temperature contours on the icing surface using the thermal camera, the salt water sample is dropped on a cold surface with the temperature of -20°C. A thermal video is recorded for 2 minutes to observe the temperature field. Examining the results obtained by the method and the experimental observations verifies the accuracy and applicability of the method.

Keywords: ice contour boundary, image processing, image segmentation, salt ice, thermal image

Procedia PDF Downloads 291
395 Asset Pricing Puzzle and GDP-Growth: Pre and Post Covid-19 Pandemic Effect on Pakistan Stock Exchange

Authors: Mohammad Azam

Abstract:

This work is an endeavor to empirically investigate the Gross Domestic Product-Growth as mediating variable between various factors and portfolio returns using a broad sample of 522 financial and non-financial firms enlisted on Pakistan Stock Exchange between January-1993 and June-2022. The study employs the Structural Equation modeling and Ordinary Least Square regression to determine the findings before and during the Covid-19 epidemiological situation, which has not received due attention by researchers. The analysis reveals that market and investment factors are redundant, whereas size and value show significant results, whereas Gross Domestic Product-Growth performs significant mediating impact for the whole time frame. Using before Covid-19 period, the results reveal that market, value, and investment are redundant, but size, profitability, and Gross Domestic Product-Growth are significant. During the Covid-19, the statistics indicate that market and investment are redundant, though size and Gross Domestic Product-Growth are highly significant, but value and profitability are moderately significant. The Ordinary Least Square regression shows that market and investment are statistically insignificant, whereas size is highly significant but value and profitability are marginally significant. Using the Gross Domestic Product-Growth augmented model, a slight growth in R-square is observed. The size, value and profitability factors are recommended to the investors for Pakistan Stock Exchange. Conclusively, in the Pakistani market, the Gross Domestic Product-Growth indicates a feeble moderating effect between risk-premia and portfolio returns.

Keywords: asset pricing puzzle, mediating role of GDP-growth, structural equation modeling, COVID-19 pandemic, Pakistan stock exchange

Procedia PDF Downloads 40
394 Impact Modified Oil Palm Empty Fruit Bunch Fiber/Poly(Lactic) Acid Composite

Authors: Mohammad D. H. Beg, John O. Akindoyo, Suriati Ghazali, Abdullah A. Mamun

Abstract:

In this study, composites were fabricated from oil palm empty fruit bunch fiber and poly(lactic) acid by extrusion followed by injection moulding. Surface of the fiber was pre-treated by ultrasound in an alkali medium and treatment efficiency was investigated by scanning electron microscopy (SEM) analysis and Fourier transforms infrared spectrometer (FTIR). Effect of fiber treatment on composite was characterized by tensile strength (TS), tensile modulus (TM) and impact strength (IS). Furthermore, biostrong impact modifier was incorporated into the treated fiber composite to improve its impact properties. Mechanical testing showed an improvement of up to 23.5% and 33.6% respectively for TS and TM of treated fiber composite above untreated fiber composite. On the other hand incorporation of impact modifier led to enhancement of about 20% above the initial IS of the treated fiber composite.

Keywords: fiber treatment, impact modifier, natural fibers, ultrasound

Procedia PDF Downloads 454
393 Spectrum and Prevalence of Candida Infection in Diabetic Foot Ulcers

Authors: Seyed Reza Aghili, Tahereh Shokohi, Lotfollah Davoodi, Zahra Kashi, Azam Moslemi, Mahdi Abastabar, Iman Haghani, Sabah Mayahi, Asoudeh A.

Abstract:

Introduction: In diabetic foot ulcers, if fungal agents such as Candida species penetrate into the cutaneous or depth of ulcer, can increase the degree of the wound and cause Candia infection and make it more difficult to heal. Material & Methods: A cross-sectional study was performed on 100 diabetic foot ulcer patients in 2020 in Sari, Iran. patient's data and wound grade were recorded in a questionnaire. Candida infection was diagnosed with direct microscopic examination and culture of samples. Colony-PCR molecular method was used for ITS region of DNA and then PCR-RFLP with Msp1 enzyme and using HWP1 specific gene to determine species of Candida agent. Results: Of 100 patients, the mean age 62.1 ± 10.8 years, 95% type 2 diabetes, 83%>10 years duration diabetes, 59% male, 66%> poor education level, 99% married, 52% rural, 95% neuropathic symptoms, 88% using antibiotics, 69%HbA1C >9%, and mean ulcer degree 2.6±1.05 were. Candida infection was seen in 13% of the deep tissue of the wound and 7% cutaneous around the wound. The predominant Candida isolated was C. parapsilosis (71.5%), C .albicans (14.3%). Fungal infections caused by mold fungi were not detected. There was a statistically significant relationship between yeast infection and gender, rural, HbA1C and ulcer degree. Conclusion: Mycological evaluations often are ignored. Candida parapsilosis is the most common infectious agent in these patients and may require specific treatment. Therefore, more attention of physicians to Candida infections particularly, early diagnosis and effective treatment can help faster recovery and prevent amputation.

Keywords: diabetic foot ulcer, candida infection, risk factors, c. parapsilosis

Procedia PDF Downloads 163