Zaidi mohd ripin

• University of Science Malaysia

The safety of coaches in frontal crashes is attracting attention in various countries. Coach crash studies are done based on standard postures. Occupants travelling long distances in coaches may fall asleep, with postures that can be different from the standard posture. This paper investigates the effects of different sleeping postures on occupant...

The Trunk Impairment Scale Version 2.0 (TIS 2.0) measures the motor impairment of the trunk after a stroke through the evaluation of dynamic sitting balance and co-ordination of trunk movement. Evaluations by physiotherapists depend on their ability in detecting minor changes in motion and observing limb movements and these can be time consuming an...

ABSTRACT Purpose: Work-related musculoskeletal disorders (WMSDs) during bed-to-wheelchair and wheelchair-to-commode transfers are a significant concern, yet prior assessments often focused on specific subtasks, overlooking potential cumulative risks. Methods: this study employed Xsens Inertial Measurement Units (IMUs) and force plates integrated...

Several low-cost force plates have been proposed as alternatives for laboratory-grade force plates. Nevertheless, the inability to quantify bilateral ground reaction force (GRF) prevents these inexpensive force plates from being used for biomechanical analysis and certain clinical metric acquisition. This study developed deep-learning models, such...

A “no-lift” policy in healthcare discourages manual patient lifting to reduce worker injuries. This study explores modifications to a floor lift (NEAR-1) to align with this policy. NEAR-1 features a shorter lower lifting arm and a redesigned sling, enabling patients to (a) transfer in a sitting position, unlike a floor lift’s semi-reclining positio...

The Vertical bearing offset is vital for the safe and efficient operation of marine shafting systems. The bearing offset is made relative to the shaft and must be tested for various operational conditions to prevent overheating, whipping, vibration, and wear that can lead to costly repairs and downtime. The offset of each bearing is achieved by min...

The demanding nature of frond cutting, which requires high cutting force, often leads to extensive physical exertion and fatigue. This study investigates the potential of utilising a pole-mounted mechanised chainsaw to minimise the pulling effort required to overcome the friction forces during oil palm harvesting. The powered chainsaw demonstrates...

Custom force plates developed from digital bathroom scales are demonstrated to be an alternative to laboratory-grade force plates. Nevertheless, applying custom force plates are questionable as the measurement accuracy has not been thoroughly validated. This study evaluated the validity of a custom force plate constructed from a digital bathroom sc...

Background: Adopting patient transfer assistive devices in healthcare is challenging, and poor decision-making can lead to low adoption. This study aims to demonstrate a technique of the decision-making process of selec- tion of patient transfer assistive devices based on work-related musculoskeletal disorders (WMSDs) risk, nurses’ instantaneous em...

This paper presents the experimental and finite element analysis of surface asperity geometry during the running-in phase of rolling contact. Previous research efforts typically relied on simulating various shapes of asperity geometry to elucidate rough surface characteristics. However, this approximation did not accurately represent the actual sur...

A high prevalence of work-related musculoskeletal disorders (WMSDs) has been reported among nurses as a result of the injuries caused by patient transfer and handling. This review examines the impact of motorised and non-motorised lifting devices on reducing physical stress during wheelchair transfers among nurses. Systematic electronic database se...

INTRODUCTION: Virtual reality (VR) holds promise for stroke rehabilitation. However, many existing VR systems requires users to stand while playing, posing a potential falling risk for stroke patients. This study investigated the effects of a custom-developed VR system that focus on trunk rehabilitation in stable sitting position on muscle activiti...

Frontal collisions of coaches contribute to more than half of the total number of casualties in traffic accidents, making it important to study frontal collisions of coaches. This literature review covers regulations, injury criteria, and factors influencing occupant injury, primarily referenced national standards on seat stability, and occupant sa...

In this study, palm olein-based grease with a micro-molybdenum disulfide (MoS2) additive has been developed. The grease was prepared using various MoS2 concentrations to investigate the role of additives in improving grease performance. A four-ball tribological test was conducted to investigate the surface morphology, wear depth, and volume loss of...

Post-stroke trunk rehabilitation often necessitates additional equipment or clinical assistance, which poses challenges in resource-limited settings. Although stable-sitting trunk exercises offer cost-effective alternatives, studies on their immediate effects are limited. Hence, this study aimed to investigate the immediate effects of five common s...

ABSTRAK Kajian sistematik ini bertujuan untuk menyiasat kesan getaran fokus (FV) terhadap tonus otot, parameter kinematik dan fungsi motor pada individu yang menghidapi penyakit strok, Parkinson dan sklerosis berbilang. Kajian ini juga bertujuan untuk menentukan pengaruh parameter getaran seperti frekuensi dan amplitud, tempoh sesi stimuli, dan jum...

This review investigates the effectiveness of assistive devices in mitigating work-related musculoskeletal disorders (WMSDs) among nurses during patient transfer tasks. It encompasses lateral transfer and repositioning devices such as air-assisted devices, friction-reducing sheets, and sliding boards, as well as vertical lifting tools like ceiling...

ABSTRAK Kajian-kajian terkini mengenai intervensi awal yang memainkan peranan penting dalam meningkatkan plastisiti neural ketika sesi rehabilitasi strok secara relatif masih terhad. Objektif kajian ini adalah untuk menyiasat keberkesanan pelbagai intervensi yang dilaksanakan dalam tempoh sebulan selepas strok bagi meningkatkan pemulihan anggota ba...

ABSTRAK Kajian ini bertujuan untuk menilai keberkesanan intensiti rawatan latihan batang tubuh pada kawalan batang tubuh pesakit strok dengan skor Skala Kerosakan Batang Tubuh (TIS). Kajian kepustakaan berstruktur telah dilakukan dalam beberapa pangkalan data daripada artikel diindeks pertama sehingga Disember 2022, termasuk PubMed, Web of Science,...

Concern over commercial mineral-based grease’s impact on the environment and its unrenewable resources requires a more sustainable alternative in lubrication. In this research, a palm olein-based grease was developed, and the effect of particle size of molybdenum disulphide (MoS 2 ) additives on the grease performance was experimentally evaluated....

Background: Work-related musculoskeletal disorders (WMSDs) are prevalent among healthcare professionals, including nurses, therapists, doctors, and paramedics, due to the potential injuries incurred during patient transfer and handling. This review aimed to assess the effectiveness of existing interventions in reducing the risks of WMSDs in this po...

Mineral oil-based lubricants have been widely used for their beneficial properties. However, their environmental impact and toxicity have raised concerns, resulting in a search for sustainable and environmentally friendly alternatives. This study investigates the tribological behavior of palm olein-based grease with copper nanoparticles additive co...

Hand force data is critical in evaluating work-related musculoskeletal disorders (WMSDs). Nevertheless, earlier studies on oil palm workers relied on estimated or laboratory measurements, which may not accurately reflect the actual hand forces. This study is the first report on the field measurement of hand forces for palm oil harvesters using a ch...

3D printed thermoplastic polyurethanes of different shore hardness were used to make hip protectors for the prevention of osteoporotic hip fracture, which was then tested. The result was used to develop a support vector regression model to estimate the effect of the protector shore hardness, shell thickness, and infill density on the impact attenua...

Purpose: Despite the proven benefits of motorized lifting devices in reducing the physical stresses experienced by nurses during patient transfers, the low adoption of these devices remains limited. The study aimed to assess the perceptions of nurses regarding the new motorized lifting device (NEAR-1) in terms of their perceived workload and usabi...

A cylindrical micro-perforated panel (MPP) can be used to absorb the sound of a flow system in a circular duct of a vacuum cleaner. A cascaded cylindrical MPP is a special class type where two cylindrical MPPs are arranged in a series to improve sound attenuation. The manufacturing of MPP primarily involves the machining of micro-perforations, beca...

Purpose The high prevalence of musculoskeletal disorders (MSDs) among healthcare workers is partly attributed to the low adoption of patient transfer assistive devices. This study aimed to evaluate the nurses’ perceived workload, technology acceptance, and emotional states during the use of the sliding board (SB) and mechanical intervention in the...

Motorcycle riders are exposed to prolonged hand-transmitted vibration that can lead to hand numbness and trembling and, in extreme cases, disorders such as the Hand-arm Vibration syndrome (HAVs). The vibration of a motorcycle handle is the result of two major excitation forces, namely the engine vibration and the road-tire vibration. Operating the...

Surface deformation in the running-in phase is crucial as it may affect the lifetime of the mechanical system. However, deformation at this phase is very small as it occurs within the asperities and is almost undetectable using conventional mass loss or the wear depth measurement technique. This study aimed to experimentally evaluate the evolution...

Bed to stretcher patient transfer by nurses involves significant manual force at various postures and could lead to work-related musculoskeletal disorders (WMSDs). Motorized Patient Transfer Device (MPTD) is a newly available patient transfer intervention and its WMSDs risk have not yet been studied. The existing REBA assessment is unable to track...

Wear during running-in of rolling contact occurs at the surface asperities level and cannot be assessed using a conventional mass loss technique due to the very small changes. The purpose of this paper is to propose an in-situ wear volume measurement using the BAC technique. The experimental work is conducted in-situ and a fixed datum is set as a r...

Aim: This study aimed to evaluate the efficacy of patient transfer assistive devices in reducing the risk of work-related musculoskeletal disorders (WMSDs) among nurses. Review method: PubMed, Scopus, Google Scholar, and the Cochrane Database of Systematic Reviews were searched to identify studies with a quantitative assessment of the efficacy o...

The characteristics of the Parkinson’s disease tremor reported previously are not applicable to the full spectrum of severity. The characteristics of high- and low-amplitude tremors differ in signal regularity and frequency dispersion, a phenomenon that indicates characterisation should be studied separately based on the severity. The subclinical t...

Mary Ann Liebert Logo 3D Printing and Additive ManufacturingAhead of Print Optimization of the Impact Attenuation Capability of Three-Dimensional Printed Hip Protector Produced by Fused Deposition Modeling Using Response Surface Methodology Suleiman Abimbola Yahaya, Zaidi Mohd Ripin, and Mohamad Ikhwan Zaini Ridzwan Published Online:12 Jul 2021 htt...

Objective Prolonged exposure to hand‐arm vibration (HAV) at the workplace is associated with hand‐arm vascular syndrome (HAVS). This study aimed to determine the prevalence and the factors associated with the vascular and neurological complications of HAVS among tire shop workers in Kelantan, Malaysia. Methods A cross‐sectional study involving 200...

Fabrication of microperforated panel (MPP) using an additive manufacturing (AM) process produced imperfect perforations with an irregular shape, inconsistent size, and rough inner surface (due to burr formation). This imperfect hole condition leads to a significant deviation between measured and modeled acoustic properties. This study aims to intro...

An innovative 3D printed hip protector has been designed and tested to decrease the possibility of hip fracture in a sideways fall to a hard surface. The main design purpose was to create custom fit hip protector, reduce the manufacturing period and make the protector comfortable to wear. This work compares the new energy shunting 3D printed hip pr...

Objectives. Exposure to hand–arm vibration (HAV) is associated with hand–arm vascular syndrome (HAVS), which is characterized by musculoskeletal complications. However, evidence on this matter has been inconclusive. Therefore, this study aimed to determine and compare the prevalence of musculoskeletal complications of HAVS between a high-exposure (...

Determining the efficacy of hip protectors designed to reduce the menace of the alarming rise in hip fracture due to fall among the elderly population is particularly challenging. Hip protector evaluation has been done using different soft tissue surrogate and at different energy level to determine the effectiveness of various hip protectors. Howev...

This study presents a development of simple expansion tube attach with micro-perforated cylindrical panel (MPCP) to improve the acoustic performance. A simulation based boundary element method (BEM) was carried out using PLM Simcenter 3D. The model was constructed in three dimensional in CAD NX Nastran 12 application and then meshing into small ele...

There have been different types of simplified femoral geometry incorporated into test systems for testing the biomechanical effectiveness of hip protectors. However, the effect of the simplification of femoral geometry in simulated sideways impact experiment has not been reported. In this study, an actual femoral geometry was fabricated and examine...

Various mechanical and biomechanical test systems to evaluate the effectiveness of hip protectors designed to prevent hip fracture as a result of falls were examined in this review. The articles considered were selected systematically. The effect of differences in design criteria was demonstrated, and it was observed that the impact energy employed...

Background: Prolonged exposure to hand-arm vibration is associated with a disorder of the vascular, neurological, and musculoskeletal systems of the upper limb known as hand-arm vibration syndrome (HAVS). Currently, the evidence of HAVS in tropical environments is limited. Objectives: To determine the prevalence and severity of HAVS among tyre s...

There is a lack of evidence that either conventional observational rating scale or biomechanical system is a better tremor assessment tool. This work focuses on comparing a biomechanical system and the Movement Disorder Society–sponsored revision of the Unified Parkinson’s Disease Rating Scale in terms of test-retest reliability. The Parkinson’s di...

Introduction Cumulative lifetime exposure to vibration is believed to contributes to more severe complications of HAVS. Objectives To determine the prevalence of neurological component of HAVS and the correlation between lifetime vibration dose (LVD) and the neurological severity of HAVS among tyre shop workers in Kelantan. Methods A cross-sectio...

In this article fatigue behavior of aluminum alloy at elevated temperature is studied. Fatigue failure is a major failure mode of failure where the cyclic load is applied to the machine element. Hence certainly it is important to know the fatigue behavior of the machine element at elevated temperature, aluminum alloy is excessively used in industry...

There are various wireless and wearable tremor assessment technologies available currently. In order to produce a reliable tremor assessment system to be used in practice, there is a need to improve the system in terms of processing time and quantification parameters. The future system should include an algorithm to separate postural and rest tremo...

Motorcycle riders are exposed to hand-transmitted vibration of the hand-arm system due to the vibration of the handle and extended exposure can result in numbness and trembling. One feasible solution to attenuate the handle vibration is by using a dynamic vibration absorber (DVA). In this work a DVA is designed and mounted on the motorcycle handle...

This paper explains the development of a lower limb stroke rehabilitation machine designed for subacute stroke patients. the system is capable of measuring the muscle force and providing goal-oriented feedback in real-time and running in two different rehabilitation modes. the mean value of engagement metric of healthy subjects using this machine w...

Objective: The objectives of this study were to determine the prevalence and severity of HAVS among tyre shop workers in Kota Bharu, Kelantan. Method: A cross-sectional study involving 100 tyre shop workers in Kota Bharu, Kelantan was conducted. Data was collected by interviewing the workers using Malay Translated HAVS questionnaire and measurement...

Despite the advancement of the tremor assessment systems, the current technology still lacks a method that can objectively characterize tremors in relative segmental movements. This paper presents a measurement system which quantifies multi-degrees-of-freedom coupled relative motions of hand–arm tremor, in terms of joint angular displacement. In-la...

This paper describes the design and development of an energy harvester based on the electromagnetic system to harvest energy in the form of low-frequency vibration. The target low frequency is around 4-10Hz which is from bridge vibration. The governing equation for electromagnetic coupling is presented. The data acquisition of the measurement test...

Wear measurement of rolling contact during running-in is challenging because the mass loss is minor and the wear track change is almost undetectable. To overcome this limitation, wear is monitored by measuring the nano-scale deformation of the surface asperities of the roller in a rolling contact using the infinite focus microscope (IFM). An accura...

This paper presents the development of low frequency electromagnetic energy harvester device integrated with low threshold voltage diode multiplier circuitry. The electromagnetic generator was designed and fabricated to demonstrate the concept and the functionality of the readout circuitry. The dimension of electromagnetic energy device is 75mm x 1...

The vibration in the rolling axis of a grass trimmer contributes to the hand arm vibration at its handle. One method to reduce the handle vibration of this engine is by attenuating the engine rolling vibration using an optimum layout of the engine mounts. Using the frequency‑dependent stiffness and loss factor properties of the rubber mount, a new...

This paper presents low frequency electromagnetic energy harvester device integrated with low threshold voltage diode multiplier circuity. The electromagnetic generator was designed and fabricated to demonstrate the concept and the functionality of the readout circuitry. The dimension of electromagnetic energy device is 75mm × 140mm. Compared to th...

A vibro-acoustic effect, in which the classical plate equation is coupled to the acoustic wave equation, was utilised to optimally tune a double-layered flexible micro-perforated panel (MPP), to achieve higher sound absorption coefficient and wider frequency band. The first nine modes considered in the present modelling study were obtained by using...

Electromagnetic acoustic noise emission in variable speed induction motor is influenced by the characteristics of Pulse Width Modulation (PWM) output from the inverter. In this paper, correlation between electromagnetic excitation from an induction motor driven by an open loop vector control inverter and the radiated electromagnetic acoustic noise...

Engine mounts are used for engine vibration isolation. The dynamic performance of the mount depends on the orientation. Measurements of the dynamic properties of engine mounts are usually performed in the axial direction because of the problem related to actuator loading direction and set up costs. Impact technique is developed here to measure the...

In this paper, noise and vibration characterization measurement based on Source-Path Receiver model is conducted on a variable speed induction motor emitting electromagnetic acoustic noise. Tracing of PWM output signal from motor inverter, experimental modal analysis, spectral test, and operational deflection shape analysis were conducted. Spectral...

An engine mounting system is the primary vibration isolator of the engine from the chassis. The frequency-dependent stiffness and loss factor present a more accurate representation of a rubber mount as opposed to the frequency-independent damping model. In this article, dynamic optimization of an engine mounting system considering the frequency-dep...

The surface of the inner race of a detachable roller bearing is monitored periodically to determine the deterioration pattern under normal conditions together with the vibration level. The surface of the inner race is scanned using an infinite focus microscope to evaluate surface properties utilizing the 2D and 3D parameters. Both parameters succes...

The intermittent transient contact of the piston skirt and cylinder liner is related to the secondary motion of the piston. The instantaneous piston secondary motion measured using laser displacement sensors can indicate whether the piston skirt is in contact with the cylinder liner. The force of the impacting piston skirt on the cylinder liner can...

The problem with wind induced noise exists in any electronic device used in the outdoor that incorporates microphone components mounted underneath small opened cavities within its body. Due to the complexity nature of the problem, efforts in trying to experimentally understand the flow induced noise problem has lengthened product development cycle...

In the drum brake system analysis, the drum is assumed to be perfectly round and this is the case as reported by simulation work done elsewhere. The true effect of roundness of the drum on the brake torque has never been investigated. In this study, a brake drum of a motorcycle is subjected to the roundness test, the brake torque test and the linin...

This paper describes the wind induced noise measurement of a two-way radio inside a wind tunnel by measuring the sound pressure level transmitted to a receiver unit placed inside the anechoic chamber. Anechoic chamber was used to isolate receiver from other outside noise. The transmitted wind noise was delivered by the receiver unit speaker and mea...

Noise generated from wind flow over a two-way radio could jeopardize communication effectiveness. A pair of two-way radio was studied where a unit (a transmitter)was placed inside a wind tunnel and the other unit (a receiver)was placed inside the anechoic chamber in order to isolate it from external noise. A speaker was located at a distance near t...

This paper presents the development wearable inertial sensors in hand arm tremor measurement. Three inertial measurement units, each with a triaxial accelerometer and a triaxial gyroscope were strapped on hand, lower arm and upper arm respectively for tremor data acquisition. The measurement device was selected based on the specifications of the co...

The study presents the electroless N-P-Cg-SiC composite coating on cast AlSi (ADC12) alloy where the bath temperature is maintained at 90°C, pH level is controlled between 4.5 to 5.0 and stirred at 450 rpm with mechanical stirrer to avoid particles sedimentation. The increase of the coating film thickness is very insignificant after one hour of coa...

The study presents the effect of heat treatment on electroless N-P-Cg-SiC composite coated cast AlSi (ADC12) alloy. No significant changes are noted on the average surface roughness and surface morphology of the coating film with different heat treatment processes. The growth of the hard Ni3P phase in the electroless Ni-P-Cg-SiC composite coating a...

A nonlinear model of the piston with reciprocating, lateral and rotational degree of freedom is developed to investigate the piston secondary motion and the induced vibration behavior of the engine block by the piston slap. The model parameters are obtained from mobility measurement. The gap between the piston skirt and the cylinder liner is modele...

An expansion chamber muffler with the use of a micro-perforated panel (MPP) was developed to improve the acoustic performance. A simulation was carried out using the SysNoise application in the LMS Virtual Lab based on the boundary element method, and the model was verified with the transmission loss measurement using the two-load method and showed...

The operational deflection shapes were used to identify the mode of vibration for the brake shoes in drum brake squeal. The measurement of the operational deflection shapes of the brake shoes during drum brake squeal, which was in the torsional mode, was similar to that of the modes obtained from the experimental modal analysis of the brake shoes u...

Drum brake squeal is modelled as friction excited vibration based on the binary flutter mechanism which requires the convergence of two modes experimentally identified using Modal Assurance Criterion. Transient analysis is carried out to determine the brake drum response under braking condition and the model produces squeal mode at 2026 Hz comparab...

An experimental technique for measuring the distinct modes of piston secondary motion is described in this study. The measurement system consists of three laser displacement sensors with the laser spots aimed at the piston crown, where the target area is machined with flat slot and a 45° slope profile to provide the necessary reflective angle in or...

Kertas kerja ini membincangkan perhubungan antara penyelenggaraan dan pemilihan pengikat bagi meningkatkan prestasi sesuatu produk dari segi jangka hayat dan struktur fizikal. Di dalam kertas kerja ini, indek kebolehsenggaraan diukur berdasarkan digraf peleraian yang dinilai bergantung kepada jenis pengikat yang digunakan dan kriteria pemasangan. L...

This paper discusses the use of the Taguchi method of experimental design in optimizing process parameters of adhesion strength between tile and mortar bed. The effects of four process parameters of force, thinset mortar thickness, shape of ribs and vibration motor speed have been explored. The primary response under study is the adhesion strength....

Integrated Definition for Function which is also known as IDEF is a well structured modeling method that corresponds to a manufacturing system. For IDEF3, it is a process description capturing method created to capture descriptions of specific sequence activities. This article discusses the details of how IDEF3 is implemented and applied in mapping...

Construction industry is very important to the developing country like Malaysia. Many challenges and difficulties must be faced by the developers of this particular field. Warszawski et. al [1] has reported that there are four serious problems in the construction industry today; low labour efficiency, high accident rate at construction sites, poor...

Prolonged use of electric grass trimmer exposes the user to the risk of hand-arm vibration syndrome. A simple approach for the suppression of hand-arm vibration in electric grass trimmer is presented. The proposed system is a tuned vibration absorber (TVA). Modal analysis and operating deflection shape analysis of the electric grass trimmer were ca...

Passive mufflers are widely used to reduce the exhaust noise level in vehicles and machines. One of the basic geometry of muffler is simple expansion chamber. In this paper, a new type of expansion chamber muffler is proposed, where micro-perforated panel (MPP) is applied on it. In this study, MPP is used to replace the porous material in the muffl...

A two degree-of-freedom model of a drum brake system is developed to investigate the criteria for unstable condition under friction-induced vibration instability mechanisms of both flutter instability and negative friction-velocity instability. This model considers the drum as the main component that is subjected to the friction-induced vibration....

The secondary motion of the piston head of a motorized engine is captured using two laser displacement sensors to obtain the piston motion and tilt angle. The controlled parameters of the measurement are engine speed, quantity of oil and oil–fuel mixture and its ratio. The reduction in friction force is more significant at dead center at high speed...

Orbital sander is widely used in the automotive repair, composite manufacturing and in fabrication of metallic panels product. However, the use of orbital sander will lead the user to health hazard associated with Hand Arm Vibration Syndrome (HAVs). Development of aftermarket active vibration cancellation (AVC) pad is explored in this paper where t...

Passive mufflers are widely used to reduce the exhaust noise level in vehicles and machines. One of the basic geometry of muffler is simple expansion chamber. Previous work in general was based on infinitely stiff backing wall. In this paper micro-perforated panel (MPP) is used in the simple expansion chamber to act as the sound absorber. In this s...

This study presents electroless Ni-P-Cg (graphite)-SiC composite coating deposition onto piston rings of a small two stroke utility engine at 90°C under Cg (10 g/l) and SiC (8 g/l) concentration at agitation speeds of 160 rpm. Coating showed compact embedding of Cg and SiC particles in Ni matrix, uniformly and largely distributed in coating by mech...

Rubber engine mounts are commonly used to provide vibration attenuation. The loss factor and dynamic stiffness of engine mount provide fundamental information of the energy dissipation. The objectives of this work are to study the frequency-dependant stiffness and loss factor of engine rubber mount and to determine the effect of the orientation ang...