141 research outputs found
Penularan penyakit beri-beri di penjara Negeri-Negeri Selat: penelitian terhadap sebab dan langkah-langkah kawalannya, 1870-1915
Pembentukan Negeri-negeri Selat (NNS) oleh pihak British pada tahun 1826 telah disusuli dengan kemajuan ekonomi secara langsung memberi kesan kepada suasana sosial dan institusi tempatan. Antara institusi tempatan yang berkembang seiring kemakmuran tersebut ialah penjara. Kepentingan penjara NNS tidak sekadar dilihat dari sudut keselamatan mahu pun sebagai kandang hukuman, seperkara yang lebih penting, banduan merupakan tenaga buruh utama untuk pelbagai keperluan pembangunan sosioekonomi. Namun menjelang suku terakhir abad ke-19, penjara di NNS diancam dengan kadar kematian yang tinggi akibat penularan penyakit beri-beri. Kerjasama dilakukan pihak pengurusan penjara dan pakar-pakar perubatan bermula dengan penelitian teori miasmatik hingga ke pendekatan dietetik, namun kematian di penjara masih berlanjutan. Objektif kajian ini adalah untuk mengesan sebab dan meneliti langkah-langkah pengawalan penyakit beri-beri yang dilaksanakan oleh British ke atas banduan di Penjara Negeri-Negeri Selat dalam tempoh 1870 hingga 1915. Metodologi kajian menggunakan kaedah kualitatif berdasarkan penelitian disiplin sejarah, justeru penelitian dilakukan dengan melihat sumber dari Arkib Negara Kuala Lumpur. Antaranya seperti Straits Settlements Files (SSF), Colonial Office (C.O), laporan-laporan tahunan bagi jabatan penjara dan jabatan perubatan. Analisis yang dilakukan mendapati, pada dekad terawal abad ke-20, usaha British membuahkan hasil apabila pencarian punca penyakit beri-beri ditemui adalah akibat kekurangan Tiamin dalam diet pemakanan, ia sekaligus membawa solusi di penjara NNS dalam masa yang sama menyumbang kepada taraf kesihatan banduan serta perkembangan ilmu perubatan moden
Vibration and acoustic pre-assessment study for free piston engine structure
This paper presents modelling and simulation study of vibration and acoustic for a new free piston engine. The free piston engine is a new engine concept where its piston motion is not restricted by the crankshaft component. The free movement of the piston influenced by forces developed from the fuel combustion process and air compression in the engine. The piston movement has become an issue or a problem which consequently developed vibration to the engine structure because of the unbalance forces. Vibration analysis has been developed using finite element software which is MSC.PATRAN in order to determine the natural frequency and frequency response of the engine structure. Theoretical development of the engine balance motion and frequency response has also been conducted. From the simulation and finite element analysis, the force response pattern of the engine vibration can be determine and compare with its natural frequency. The vibration analysis will then be used as the input data for acoustic analysis of the engine. The acoustic analysis used boundary element method coupled with finite element method to determine the noise level produce by the engine structure. This integration determined the noise - frequency data that affected the engine structure towards the occurrence of engine noise especially when engine is in operation mode
Potensi di luar tempurung : halatuju digitalisasi sejarah di Malaysia
Kajian ini bertujuan untuk mendedahkan kepada tenaga pengajar tentang pendigitalan sejarah dan aplikasi disiplin
baru ini dalam pengajaran dan pembelajaran sejarah Malaysia. Kajian ini merujuk kepada perkembangan di negara
Barat di mana aplikasi digital dan pendekatan pelbagai disiplin telah digunakan untuk memperkasakan bidang
sejarah. Komponen utama dalam pendekatan ini adalah disiplin sejarah dan salah satu disiplin pelengkap adalah
bidang geografi. Sistem maklumat geografi dan aplikasi sistem maklumat geografi berasaskan internet atau dikenali
sebagai Web-based Geographic Information System (web-based GIS) merupakan antara aplikasi yang disarankan
dalam projek digitalisasi sejarah atau pendigitalan sejarah. Hasil kajian menunjukkan betapa pentingnya tenaga
pengajar di Malaysia menggunakan pendekatan sejarah yang inovatif agar dapat memenuhi kehendak generasi Y
yang celik komputer dan inginkan pembaharuan yang menarik dalam pengajaran dan pembelajaran sejarah. Justeru
itu, kajian ini mendedahkan tenaga pengajar kepada pendekatan baharu dan ia penting dalam usaha menarik minat
pelajar terhadap ilmu sejarah serta menghargai kerelevenan sejarah dalam kehidupan seharian. Pendekatan baharu
ini juga dapat memperkasakan ilmu sejarah dengan melibatkan kerjasama kerajaan dan swasta dalam projek
digitalisasi yang dibangunkan
Vibration Performance of a Flow Energy Converter behind Two Side-By-Side Cylinders
Flow-induced vibrations of a flexible cantilever plate, placed in various positions behind two side-by-side cylinders, were computationally investigated to determine optimal location for wake-excited energy harvesters. In the present study, the cylinders of equal diameter D were fixed at center-to-center gap ratio of T/D = 1.7 and immersed in sub-critical flow of Reynold number ReD = 10, 000. A three-dimensional Navier-Stokes flow solver in an Arbitrary Lagrangian-Eulerian (ALE) description was closely coupled to a non-linear finite element structural solver that was used to model the dynamics of a composite piezoelectric plate. The cantilever plate was fixed at several positions between 0.5 < x/D < 1.5 and -0.85 < y/D < 0.85 measured from the center gap between cylinders, and their flow-induced oscillations were compiled and analyzed. The results indicate that flexible plates located at the centerline between the cylinder pairs experience the lowest mean amplitude of oscillation. Maximum overall amplitude in oscillation is predicted when flexible plates are located in the intermediate off-center region downstream of both cylinders. Present findings indicate potential to further maximize wake-induced energy harvesting plates by exploiting their favorable positioning in the wake region behind two side-by-side cylinders. © 2019 by the authors
Integration of feedforward neural network and finite element in the draw-bend springback prediction
To achieve accurate results, current nonlinear elastic recovery applications of finite element (FE) analysis
have become more complicated for sheet metal springback prediction. In this paper, an alternative
modelling method able to facilitate nonlinear recovery was developed for springback prediction. The
nonlinear elastic recovery was processed using back-propagation networks in an artificial neural network
(ANN). This approach is able to perform pattern recognition and create direct mapping of the elasticallydriven
change after plastic deformation. The FE program for the sheet metal springback experiment was
carried out with the integration of ANN. The results obtained at the end of the FE analyses were found to
have improved in comparison to the measured data
Simulation of Cathodic Protection on Reinforced Concrete Using BEM / Syarizal Fonna...[et al.]
This study is to simulate the cathodic protection (CP) system on a reinforced concrete (RC) structure using the boundary element method (BEM). For simulation purposes, the RC domain was modeled by a Laplace equation. The boundary condition for the sacrificial anode and cathode (reinforcing steel) were obtained from its polarization curve. By solving the Laplace equation using BEM, all electrical potential values on the RC domain could be determined. Thus, the CP system could be evaluated based on the electrical potential on the reinforcing steel. Two studies were conducted by performing BEM simulation, where the CP system model and geometry for the studies were obtained from a previous researcher. The first study was to compare the simulation with experimental results. The second was to study the influence of several parameters on the electrical potential on the reinforcing steel. The BEM simulation results show that displacement between the anode and reinforcing steel would affect the electrical potential on the reinforcing steel. This was consistent with the experimental result. The simulation results also show that the anode size and conductivity of the concrete would affect the electrical potential on the surface of the reinforcing steel. Therefore, it is important to take account of those parameters in designing and/or evaluating the CP system for RC structures
Stress intensity factors under combined bending and torsion moments
This paper discusses stress intensity factor (SIF) calculations for surface cracks in round bars subjected to combined
torsion and bending loadings. Different crack aspect ratios, a/b, ranging from 0.0 to 1.2 and relative crack depths, a/D, ranging
from 0.1 to 0.6 were considered. Since the loading was non-symmetrical for torsion loadings, a whole finite element model was
constructed. Then, the individual and combined bending and torsion loadings were remotely applied to the model. The equivalent
SIF method, F*
EQ, was then used explicitly to combine the individual SIFs from the bending and torsion loadings. A comparison
was then carried out with the combined SIF, F*
FE, obtained using the finite element analysis (FEA) under similar loadings. It was
found that the equivalent SIF method successfully predicted the combined SIF for Mode I. However, discrepancies between the
results determined from the different approaches occurred when FIII was involved. It was also noted that the predicted F*
FE using
FEA was higher than the F*
EQ predicted through the equivalent SIF method due to the difference in crack face interactions
Finite Element Analysis of J-Integral for Surface Cracks in Round Bars under Combined Mode I Loading
This paper numerically discusses the role of J-integral along the surface crack front in cylindrical bar under combined mode I loading. It is also verified the analytical model derived from the first part of this paper by comparing the results obtained numerically using ANSYS finite element program. It is found that the proposed model capable to predict the J-integral successfully along the crack front but not for the area away from the deepest crack depth. This is probably due to the fact that the problem of singularity
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