Investigating the Awareness of Onsite Mechanization in Malaysian Construction Industry

AbstractThe Malaysian construction industry is vital for the country economy and always played a key role towards the development of national infrastructure. The ever-increasing market competitiveness and the widespread adoption of Industrialized Building System (IBS) by the local contractors derive the industry to improve the existing processes for achieving higher levels of quality and products. This transition from traditional methods of construction give a momentum to the deployment of onsite mechanized equipments. The utilization of mechanized equipments increases construction productivity and as well as reduces the dependency on foreign labour. However, a large amount of construction company's capital is also invested in procuring these equipments. In addition to this, varieties of construction equipments are also required for carrying out these operations. Therefore, the aim of this paper is to investigate the current awareness and application of onsite mechanization in Malaysian construction industry. A questionnaire survey was conducted among a classified group of Construction Industry Development Board of Malaysia (CIDB) G7 Class ‘A’ contractors. The results of the survey show that there is a good understanding of Malaysian contractors towards mechanization. It is also revealed that the adoption of IBS have a direct correlation with the usage of onsite machineries and equipments. Results further indicate that excavation, earthworks, pilling works and structural works have high utilization of mechanized construction equipments. The study will help to find out the existing level of mechanization practices in Malaysian construction industry

A new off-board electrical vehicle battery charger: topology, analysis and design

The extensive use of electric vehicles (EVs) can reduce concerns about climate change and fossil fuel shortages. One of the main obstacles to accepting EVs is the limitation of charging stations, which consists of high-charge batteries and high-energy charging infrastructure. A new transformer-less topology for boost dc-dc converters with higher power density and lower switch stress is proposed in this paper, which may be a suitable candidate for high-power fast-charging battery chargers of EVs. Throughout this paper, two operating modes of the proposed converter, continuous current mode (CCM) and discontinuous current mode (DCM), are analyzed in detail. Additionally, critical inductances and design considerations for the proposed converter are calculated. Finally, real-time verifications based on hardware-in-loop (HiL) simulation are carried out to assess the correctness of the proposed theoretical concepts

Draft genome sequence of arsenic- resistant Microbacterium sp. strain SZ1 isolated from arsenic-bearing gold ores

Microbacterium sp. strain SZ1 isolated from gold ores of a Malaysia gold mine was found to be highly resistant to arsenic. Here, we report the draft genome sequence of SZ1, which may provide further insights into understanding its arsenic resistance mechanism. In this draft genome, a complete set of ars operons and two additional scattered ars genes were encoded

Effects of Cutter Geometrical Features on Machining Polyetheretherketones (PEEK) Engineering Plastic

When polyetheretherketone is used in structural applications it generally undergoes additional machining operations in order to form components. Machining PEEK can be a challenging task for manufacturers, however, especially when using a conventional cutting tool. This paper deals with the influence of a cutter’s geometrical features when machining polyetheretherketones engineering plastic on their machining performances. Three categories of end mills were designed and fabricated with varying rake angles, clearance angles and helix angles to investigate effects on machining surface roughness and burr formation. From the investigations conducted, it is evident that end mill geometrical features (rake angle, clearance angle and helix angle) have significant effects on machining surface roughness and burr formation. Increasing the rake angle and helix angle value will improved the machining surface roughness, however, in the case of varying clearance angles, there are no significant results for the surface roughness produced. It could be observed, however, that a 12° clearance angle produced better surface roughness compared to other angles. The findings from the deliberately conducted experiments can be used for the development of high performance cutting tools, especially for machining polyetheretherketones engineering plastic material

Simulation Modeling The Performance of Ocean Thermal Energy Conversion Power Cycle

Ocean Thermal Energy Conversion (OTEC) is a foundation for an appealing renewable energy technology with regards to its vast and inexhaustible resources of energy, renewability, stability, and sustainable output. The principle of an OTEC power plant is to exploit the energy stored in between the upper layer of warm surface seawater (heat source), and the cold layer of deep seawater (heat sink). The plant operates based on a Rankine cycle to produce electricity between the source and the sink at the minimum temperature difference of approximately 20 K. The main objective of this study is to evaluate the performance of the proposed OTEC closed Rankine cycle using ammonia as the working fluid, to be paralleled with basic OTEC Rankine cycle. Preliminary simulation was performed at the initial stage of the study to validate the simulation model by referring to previous OTEC studies. The same developed model was deployed to test the efficiency of the proposed modified OTEC Rankine cycle, resulting in an enhancement in terms of thermal cycle performance from 3.43% to 7.98%. This study has revealed that the proposed OTEC closed Rankine cycle which introduced an interstage superheating as well as an improved condenser cooling system, augmented the system competence of an OTEC power cycle

Electroless Ni-Co-Cu-P Alloy Deposition in Alkaline Hypophosphite Based Bath

The use of electroless deposition method to deposit nickel alloy attracts attention due to its uniformity, corrosion resistance in neutral media and low friction. Quaternary nickel alloy deposit can be achieved by adding metal ion additive into the plating bath. Furthermore, the use of alkaline bath can accelerate the deposition rate, and provide sufficient thickness for corrosion protection. In this study, an electroless quaternary nickel alloy is deposited on iron coupons by adding cobalt and copper ions in hypophosphite based Ni-P alkaline bath. The nickel alloy deposit surface morphology is studied using scanning electron microscope (SEM) and x-ray fluorescence(XRF). Corrosion behavior of the nickel alloy is investigated using polarization curve measurement in 3.5wt% NaCl aqueous solution. From the results, the elecroless Ni-Co-Cu-P alloy coating produced at higher plating bah pH is harder than the lower bath pH. Higher Co, Cu and P content in the Ni alloy exhibit broader passive area in the polarization curve measurement results

The Effect of Edm Die-sinking Parameters on Material Removal Rate of Beryllium Copper Using Full Factorial Method

The effect of electrical discharge machining (EDM) die-sinking parameters on material removal rate (MRR) of Beryllium Copper (BeCu) was studied. EDM die-sinking is one of the important non-traditional machining processes and it is widely accepted as a standard machining process in the manufacturing of forming tools to produce mould and die. The appropriate parameters were selected to study the influence of operating parameters of BeCu on MRR. Electrolytic copper was selected as electrode with positive polarity. The experiment was done using SODICK AQ35L EDM machine. Two level approach of full factorial design of experiment was applied to design the experimental and the data was analyzed by using analysis of variance (ANOVA) and the optimal combinations of the process parameters were predicted. It is found that peak current was the most significant factor affecting the MRR. Further, pulse on time and pulse off time must be combined with other factors in order to influence the machining characteristics. Finally, machine voltage shows less significant factor for the EDM die-sinking process on BeCu

Molecular dynamics simulations suggest changes in electrostatic interactions as a potential mechanism through which serine phosphorylation inhibits DNA Polymerase β’s activity

DNA polymerase ß is a 39 kDa enzyme that is a major component of Base Excision Repair in human cells. The enzyme comprises two major domains, a 31 kDa domain responsible for the polymerase activity and an 8 kDa domain, which bind ssDNA and has a deoxyribose phosphate (dRP) lyase activity. DNA polymerase ß was shown to be phosphorylated in vitro with protein kinase C (PKC) at serines 44 and 55 (S44 and S55), resulting in loss of its polymerase enzymic activity, but not its ability to bind ssDNA. In this study, we investigate the potential phosphorylation-induced structural changes for DNA polymerase ß using molecular dynamics simulations. The simulations show drastic conformational changes of the polymerase structure as a result of S44 phosphorylation. Phosphorylation-induced conformational changes transform the closed (active) enzyme structure into an open one. Further analysis of the results points to a key hydrogen bond and newly formed salt bridges as potential drivers of these structural fluctuations. The changes observed with S55/44 and S55 phosphorylation were less dramatic and the integrity of the H-bond was not compromised. Thus the phosphorylation of S44 is the major contributor to structural fluctuations that lead to loss of enzymatic activity

Rituximab in rheumatology: single-centre SARS-CoV-2 infection and COVID-19 prevalence.

We describe a coronavirus disease 2019 (COVID-19) prevalence of 20% in rheumatic disease patients treated with rituximab, with 10.3% of these (2% of the entire cohort) having died of COVID-19-related causes