Seismic behavior of RC columns internally confined by CFRP strips

Halim, Nur Hajarul Falahi Abdul,Alih, Sophia C.,Vafaei, Mohammadreza Techno-Press 2021 Advances in concrete construction Vol.12 No.3

During past decades fiber-reinforced polymer (FRP) sheets have been externally bonded to structural elements to increase their axial, shear, or bending capacity. FRP bars also have been widely used to replace the steel reinforcements in columns subjected to a harsh environment. In this study, carbon fiber-reinforced polymer (CFRP) strips were used as the transverse reinforcement for concrete columns. Although FRP bars have already been used as the transverse reinforcement in concrete columns, the efficiency and feasibility of CFRP strips have not been investigated. CFRP strips are flexible; therefore, they can be easily shaped as spirals to confine the concrete core of columns. The efficiency of CFRP strips for the confinement of the concrete core was examined through a series of quasi-static cyclic tests on four full-scale columns that had similar size and longitudinal reinforcements. One of the columns was selected as the reference, and steel spirals transversally reinforced it. CFRP strips transversally reinforced the other three columns with different widths and spacing. The obtained results showed that the number of cracks in the CFRP-confined columns was less than the reference column. The length of cracks in the CFRP-confined columns was also relatively shorter. Besides, the CFRP-confined columns had a larger ultimate load, effective yield strength, and displacement ductility ratio compared with the reference column.

The Level of Teaching Knowledge Preschool Teachers in Malaysia

Abdul Halim Masnan,Nur Ellina Anthony,Nur Arifah Syahindah Zainudin 환태평양유아교육연구학회 2019 Asia-Pacific journal of research in early childhoo Vol.13 No.2

A quality teaching model includes elements such as teaching knowledge, skills, and attitudes. This study seeks to discover the level of teaching knowledge of preschool teachers. The methodology of the study is a qualitative methods using case study. The instruments used were interviews and document analysis while the respondents who received excellent teaching awards were identified using purposive sampling. The two excellent preschool teachers were interviewed. Results of the study found that the knowledge of the teachers was found to increase through their experience and adopted various methods of teaching to help the children understand the learning. An appropriate teaching method was used to capture and retain the children’s attention as well as improve their ranking and achievement. Overall, preschool teachers are aware that the method of teaching plays an important role in the teaching and learning process.

Low Frequency Vibration Energy Harvester Using Stopper-Engaged Dynamic Magnifier for Increased Power and Wide Bandwidth

Halim, Miah Abdul,Kim, Dae Heum,Park, Jae Yeong The Korean Institute of Electrical Engineers 2016 Journal of Electrical Engineering & Technology Vol.11 No.3

We present a piezoelectric energy harvester with stopper-engaged dynamic magnifier which is capable of significantly increasing the operating bandwidth and the energy (power) harvested from a broad range of low frequency vibrations (<30 Hz). It uses a mass-loaded polymer beam (primary spring-mass system) that works as a dynamic magnifier for another mass-loaded piezoelectric beam (secondary spring-mass system) clamped on primary mass, constituting a two-degree-of-freedom (2-DOF) system. Use of polymer (polycarbonate) as the primary beam allows the harvester not only to respond to low frequency vibrations but also generates high impulsive force while the primary mass engages the base stopper. Upon excitation, the dynamic magnifier causes mechanical impact on the base stopper and transfers a secondary shock (in the form of impulsive force) to the energy harvesting element resulting in an increased strain in it and triggers nonlinear frequency up-conversion mechanism. Therefore, it generates almost four times larger average power and exhibits over 250% wider half-power bandwidth than those of its conventional 2-DOF counterpart (without stopper). Experimental results indicate that the proposed device is highly applicable to vibration energy harvesting in automobiles.

Organizational Justice, Job Satisfaction and Islamic Spirituality among Malaysian SME Employees

Abdul Halim Bin Abdul MANAF,Mohamed SULAIMAN,Suhaimi Mhd SARIF,Abdul Kadir OTHMAN 한국유통과학회 2022 The Journal of Asian Finance, Economics and Busine Vol.9 No.1

The role of Islamic spirituality in the relationship between organizational justice (OJ) and job satisfaction is investigated in this study (JS). The three components of OJ in this study are distributive, procedural, and interactional justice. Islamic spirituality (IS) is founded on piety values, and IS was used as a moderating factor in this study to alter the link between OJ and JS among Malaysian employees of small and medium enterprises (SMEs). Four hundred sets of the questionnaire were issued using a simple random selection procedure, yielding 276 completed responses, suggesting a 69 percent response rate. Multiple Linear Regression Analysis (MLRA) was used to test the proposed relationships. The findings of the study demonstrate that the three OJ aspects have a considerable impact on employee JS, indicating the significance of these elements in ensuring that employees are satisfied with their jobs. IS, on the other hand, had no effect on the link between the OJ dimensions and JS. This research has added to the existing body of knowledge by giving further empirical evidence on the impact of OJ aspects on employee JS in SMEs, notably in Malaysia.

Low Frequency Vibration Energy Harvester Using Stopper-Engaged Dynamic Magnifier for Increased Power and Wide Bandwidth

Miah Abdul Halim,Dae Heum Kim,Jae Yeong Park 대한전기학회 2016 Journal of Electrical Engineering & Technology Vol.11 No.3

We present a piezoelectric energy harvester with stopper-engaged dynamic magnifier which is capable of significantly increasing the operating bandwidth and the energy (power) harvested from a broad range of low frequency vibrations (<30 Hz). It uses a mass-loaded polymer beam (primary spring-mass system) that works as a dynamic magnifier for another mass-loaded piezoelectric beam (secondary spring-mass system) clamped on primary mass, constituting a two-degree-of-freedom (2-DOF) system. Use of polymer (polycarbonate) as the primary beam allows the harvester not only to respond to low frequency vibrations but also generates high impulsive force while the primary mass engages the base stopper. Upon excitation, the dynamic magnifier causes mechanical impact on the base stopper and transfers a secondary shock (in the form of impulsive force) to the energy harvesting element resulting in an increased strain in it and triggers nonlinear frequency up-conversion mechanism. Therefore, it generates almost four times larger average power and exhibits over 250% wider half-power bandwidth than those of its conventional 2-DOF counterpart (without stopper). Experimental results indicate that the proposed device is highly applicable to vibration energy harvesting in automobiles.

Design and Fabrication of Cylindrical Structure based Non-resonant, Frequency Up-converted Electromagnetic Energy Harvester using Non-magnetic ball

MD. Abdul Halim Miah(할림 미아),Ye-Eun Na(나예은),Sang-IL Han(한상일),Sung-Min Park(박성민),Jong-Hwi Lee(이종휘),Chan-Yang Kim(김찬양),Jae-Hyun Kim(김재현),Jae-Yeong Park(박재영) 대한전기학회 2013 대한전기학회 학술대회 논문집 Vol.2013 No.7

Sustainable Machining of Hardened Inconel 718: A Comparative Study

Nurul Hayati Abdul Halim,Che Hassan Che Haron,Jaharah Abdul Ghani 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.7

Recent trends in metal cutting shows the increasing of demand at the global stage for the application of eco-friendly machining approaches in order to eliminate the adverse effects of conventional cutting fluids. Thus, this experimental work was conducted to evaluate the performance of sustainable cooling techniques of cryogenic carbon dioxide (CO2), Minimum Quantity Lubrication (MQL), cryogenic liquid nitrogen (LN2) and dry cutting on machinability of Inconel 718. For the cryogenic CO2 approach, a new concept of cryogenic cooling technique was introduced for efficient and consistent cooling performance. The findings displayed cryogenic CO2 as a promising coolant since it resulted in slower tool wear rate compared to cryogenic LN2 and dry cutting, while being more effective in decreasing cutting forces and surface roughness compared to other approaches. Its adequate and consistent cooling efficiently disperses the generated heat and creates an ideal cutting condition for the tool and workpiece to interact with each another during cutting. In contrast to MQL cutting, the usefulness of CO 2 was supplanted due to the resulting shorter tool life. As such, the MQL approach is preferred as it extends the tool life longer by 67.2% with the maximum volume of material removal as compared to cryogenic CO2. Its lubrication impact shows effectiveness in diminishing the tool wear rate than the cooling effect by the cryogenic CO2. However, from the viewpoint of sustainability, MQL could be less preferable due to unpleasant odour and settling of MQL mist around the cutting area.

Chitosan Immobilized Aggregated Methylobacterium oryzae CBMB20 for Plant Growth Promotion (PGP) in Tomato for Mitigation of Salinity Stress

김용헌 ( Md Abdul Halim ),사동민 ( Mak Chanratana ),( Shamim Ahmed ),( Yongheon Kim ),( Tongmin Sa ) 한국환경농학회 2017 한국환경농학회 학술대회집 Vol.2017 No.-

Successful colonization of bio-inoculants face hostile environmental conditions like salinity in the rhizosphere of plant. The survivability and adaptation under stress is a major concern for bio-inoculants. Thus, the current study were focused on survivability improvement of the chitosan aggregated Methylobacterium oryzae CBMB20 and pant growth promotion (PGP) of tomato plant under salt stress. At different temperature (4, 30, 40 and 50℃) the capability of the bio-inoculant with either liquid or chitosan based formulation was observed for 3 months of storage and used to examine the effect on tomato plant under salt stress. Furthermore, the poly-β-hydroxybuterate (PHB) content, exopolysaccharide (EPS) production, biofilm formation, and microbial cell hydrophobicity as physiological parameter were studied. It was revealed that the aggregated exposed statistically significant over non-aggregated bioinoculants. In addition, to tolerate UV, heat, desiccation, low temperature, starvation, and H2O2 potentiality were higher for the aggregated M. oryzae CBMB20 than other. Particularly, chitosan immobilized aggregated M. oryzae CBMB20 exhibit 4 to 30℃ optimum storage temperature and 24.67, 36.65 and 59.53% reduction in cfu counts after 90 days of storage at temperatures 4, 30 and 40℃), respectively. Moreover, chitosan immobilized aggregated M. oryzae CBMB20 evinced by 1.9, 1.6 and 1.9-times seed germination, seedling vigor index and plant dry weight, consequently under salt. Hence, chitosan boost the lodging the aggregated bacterial cells that prompt the bio-inoculants survivability and salt stress adeptness in the rhizosphere which leads the growth and development of tomato plant.

Selecting Tanker Steaming Speeds under Uncertainty: A Rule-Based Bayesian Reasoning Approach

N.S.F. ABDUL RAHMAN,R.MD. HANAFLAH,A.F. AHMAD NAJIB,W.M.Z. ABDUL HALIM 국제이네비해양경제학회 2015 International Journal of e-Navigation and Maritime Vol.2 No.1

In the tanker industry, there are a lot of uncertain conditions that tanker companies have to deal with.For example, the global financial crisis and economic recession, the increase of bunker fuel prices and global climate change. Such conditions have forced tanker companies to change tankers speed from full speed to slow speed, extra slow speed and super slow speed. Due to such conditions, the objective of this paper is to present a methodology for determining vessel speeds of tankers that minimize the cost of the vessels under such conditions. The four levels of vessel speed in the tanker industry will be investigated and will incorporate a number of uncertain conditions. This will be done by developing a scientific model using a rule-based Bayesian reasoning method. The proposed model has produced 96 rules that can be used as guidance in the decision making process. Such results help tanker companies to determine the appropriate vessel speed to be used in a dynamic operational environmental.

Prediction of breakthrough curves for light hydrocarbons adsorption on 4A molecular sieve zeolite

Muthanna Jabbar Ahmed,Abdul Halim Abdul Karim Mohammed,Abdul Amir Hassan Kadhum 한국화학공학회 2010 Korean Journal of Chemical Engineering Vol.27 No.3

Breakthrough curves for the adsorption of methane, ethane, and propane mixture on 4A molecular sieve zeolite were obtained experimentally and theoretically at a constant temperature of 301 K. The equilibrium model and linear driving force model were used to predict the experimental breakthrough curves for this multi component mixture. The equilibrium model gave a satisfactory fit for experimental data. The model equations were solved by a numerical method based on backward finite difference with a fixed griding technique. The effect of feed flow rate (0.385-3.465 l/min), feed concentration (60.72-182.16 mmole/l), and adsorbates composition (11.73-20.11%) on the breakthrough curves were examined.