Dian Darina Indah Daruis

Study of Noise, Vibration and Harshness (NVH) for Malaysian Army (MA) 3-Tonne Trucks

Moving vehicle will produce dynamic excitation and can be categorized in the study of noise, vibration and harshness (NVH). Studies of NVH can resolve issues associated with the use of a vehicle comfort. Exposure to some level of noise and vibration can be classified as a danger to vehicle passengers if they are exposed in a standard eight-hour time period. Therefore NVH aspect is the most important aspect in selecting a military vehicle other than the factor of safety, reliability, fuel consumption and maintenance costs. This study was carried out on Malaysian Army (MA) 3-tonne truck drivers who are exposed to noise and vibration produced by the truck. Vibration exposure at seat, steering wheel and body floor was measured using tri-axial and single axis accelerometers which were connected to a Brüel & Kjær Type 3649 vibration analyser, while noise exposure was measured at the drivers ear position using a DuO smart noise monitor. From the results obtained, both vibration and noise pressure levels increased proportionally with the increasing speed of the truck. In the long-term, will have an impact on the health of the truck drivers.

Correlation between Whole Body Vibration Exposure and I-KazTM 3D Coefficient for Malaysian Army 3-Tonne Truck Drivers

Exposure to high levels of whole body vibration (WBV) from the seat can present risks to health and safety and cause injuries to drivers. This study presents a study on WBV exposure to Malaysian Army 3-tonne truck drivers using the method defined in International Standard ISO 2631-1:1997. The vehicle that was chosen for this study was based on the highest number of vehicles available within the Malaysian Army services. 3-tonne truck is the most widely used in Malaysian Army services. WBV from the drivers were measured using tri-axial accelerometer and was connected to Brüel & Kjær Vibration Analyser Type 3649, which is capable to produce raw data to calculate the vibration dose value (VDV). The raw data from each axis were analyzed using statistical analysis method, Integrated Kurtosis Algorithm for Z-notch Filter (I-kazTM) 3D to determine the vibration values in relation to varying speed of the vehicle. Based on the results, WBV experienced by the drivers can be presented in VDV and I-kazTM 3D coefficient which the value will increase proportional to the truck speed.

Investigation of oil palm harvesters' postures using RULA analysis

Manual workers in agricultural industry are frequently exposed to work related discomfort and pain while performing their work tasks. This leads to common health problems such as Work-related Musculoskeletal Disorders (WMSDs) which occur due to the feeling of discomfort while performing daily tasks, which in turn affect their work performance. An interview was conducted with three palm oil harvesters to gather information regarding their body part discomfort and general view on working conditions. Consequently, a video camera was used to record the postures and movements of these harvesters while performing their tasks. The Digital Human Modeling Software (DHMS) was used to analyze the postures by using Rapid Upper Limb Assessment (RULA) analysis. The findings showed that the harvesters experienced body part discomfort mainly on the upper body limbs. Based on the RULA analysis, all recorded postures were unsafe hence immediate actions should be implemented to ensure safe and comfortable working conditions. The main problems were their repetitive movements, awkward postures and heavy tools used when performing the work tasks. Necessary actions should be taken to minimize work risk.

The Treated Cellulose Micro/Nano Fibers (CMNF) from Bioresources in Malaysia

Cellulose Micro/Nano fibers (CMNF) from various plants which is Resak (Vatica spp.) waste, Merbau (Intsia bijuga) waste, banana (Musa acuminata) pseudo-stem and pineapple (Ananas comosus) leaf fibers have been isolated and characterized. Isolation of microfibril cellulose from raw fibers was achieved using alkaline treatment and bleaching. The treated and untreated samples were characterized using x-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). Characterizations of treated and untreated samples were compared. The comparison between those treated and untreated samples giving different crystallite size, crystallinity, arrangement of CMNF and surface morphology from different plants. Hence, with these information different nanocomposite from CMNF can be constructed and manipulated for various application.

A study on the prevalence of musculoskeletal disorders among health care workers at a private medical centre

A study was conducted among healthcare workers performing manual handling tasks at a private medical center (PMC) in Selangor to determine the prevalence of musculoskeletal disorders (MSDs). A total of 103 workers of the PMC were selected through simple random sampling which comprise of 32 respondents for administrative group and another 71 respondents for operative group of Malaysian citizen, not pregnant and never been involved with any type of accident that involved musculoskeletal system. Modified questionnaire was used to gather the information of respondents. In this study, Body Parts Symptoms Survey (BPSS) form was used to determine which of 12 body parts were exposed to the MSDs risks that can be associated with manual handling tasks. For assessment of manual handling, a posture-based analysis system for Rapid Entire Body Assessment (REBA) responsive to musculoskeletal risks in various tasks was used. Lower back region indicated the highest prevalence (21.4%) of MSDs among workers in PMC followed by shoulder (14.6%) and neck (13.6%). For assessment of manual handling, there was significant difference of REBA score between administrative and operational workers (Z = 3.501, p = 0.001). Manual handling was significantly associated with MSDs that involved all body parts for operative workers while for administrative workers, manual handling was significantly associated with shoulder (r = 0.376, p = 0.034), upper back (r = 0.473, p = 0.010), elbow (r = 0.397, p = 0.024), lower back (r = 0.337, p = 0.050) and arm (r = 0.478, p = 0.016). In conclusion, the prevalence of MSDs among healthcare workers is high at lower back region and there was significant association between manual handling and MSDs among them.

Assessment of Hand-Arm Vibration Exposure among Motorcyclist in Malaysia

Motorcyclists are road users that highly exposed to hand-arm vibration that may contribute to body discomfort and fatigue that eventually will lead to road accidents and injuries. The two main objectives of this study are to identify the body parts that experience discomfort among motorcyclist and to understand the vibration exposure effect on different road types. In this study, two research methodologies were used; first, a survey questionnaire of 100 motorcyclists and second, an experimental study on hand-arm vibration (HAV) measurement exposed on motorcyclist using accelerometer mounted on the right side handlebars of the motorcycle. Two male respondents with a different weight range, 45-65 kg and >70 kg are selected for this experiment. The experiment was conducted on two different types of roads: tarmac road and pave road within a speed limit of 20-40 m/s2. Results of the study showed that the motorcyclist usually experienced body discomfort at lower back, upper back, wrist, buttock and neck area. The root-mean-square (r.m.s) frequency-weighted acceleration on the handlebars of the motorcycles was in the range of 0.07 m/s r.m.s for the tarmac road and 0.42 m/s r.m.s for the pave road. This value shows that different road type is affecting the vibration exposed to the motorcyclist. Clearly there’s a vibration felt by the motorcyclist but not on the degree of causing pain but a prolonged exposure to this vibration may induce discomfort and injuries.

A STUDY OF MUSCULOSKELETAL DISORDERS AMONG VISUAL DISPLAY TERMINAL WORKERS

This study investigated the effectiveness of workstation ergonomic intervention in reducing musculoskeletal disorders (MSD) in Visual Display Terminal (VDT) workers. The study was carried out at one of a Multinational Company in Petaling Jaya, Selangor. Sixty Heavy VDT workers were selected randomly as case study respondents. Questionnaires were given to 60 respondents to investigate their awareness in ergonomic intervention, job-related factors that contributing to musculoskeletal disorders, as well as MSD severity and symptoms among them. Then, 30 workers who are heavy VDT users were selected to receive the education and ergonomics interventions, whereas another 30 receive the education and ergonomic intervention, whereas another 30 workers were assigned as a control group. The two groups were then crossedover after sixth week, and follow-up questionnaire s we given to all of them once again. The results for both questionnaires, before and after the ergonomics intervention, were then analyzed for this case study. The interventions include ergonomics leaflets, ergonomic posters, online ergonomic education and ergonomic working posture guidance. The outcomes suggested that a participation in an ergonomics program, even though in a short duration and minimally disruptive to the normal workplace routine, can still contribute to a rapid effect on improving work posture. Although improper posture is associated to be the main risk factor for work-related musculoskeletal disorders, multigroup and long-term randomized trial are required to establish the effectiveness or workstation ergonomic intervention in reducing musculoskeletal disorders in VDT workers. In conclusion, there is significant evidence that individualized ergonomic interventions may contribute to improve work-related posture and reduce MSD injuries for VDT workers.

Exoskeleton for human energy augmentation the Shadow Suit concept: Lower extremity development of the Shadow-Suit

To facilitate kinematic changes in expendable exoskeletons, considerations must be placed on the links leading to the end joint(s), where rigid connections with human limbs could lead to uncomfortable experiences for a pilot operating the exoskeleton. To cater to changes in human size while maintaining initial kinematic computation, an additional exoskeleton named the Shadow-Suit is proposed as a control module to provide feedback to the exoskeleton (the outer shell). This Shadow-Suit is an anthropomorphic suit to be attached to the non-anthropomorphic exoskeleton (outer shell), where movements of this suit will be “shadowed” by the outer shell exoskeleton. This paper focuses on the development of the lower extremity of this Shadow-Suit concept. The kinematics of the lower extremity was computed using Denavit-Hartenberg modelling, where the end joint of the lower extremity is predicted during a normal walking stance of the pilot. Sensory feedback was processed by Omron CPM-2A PLC module, in which lag of the reaction of the pneumatic actuator on the outer shell exoskeleton was able to be minimized to the point of ≈1.2 seconds. Result suggest that this concept is able to reduce the excessive torque towards the pilot, while at the same time able to accommodate different pilot limb length without having to change the link length of the exoskeleton.

A Survey on Sleeping Patterns and Fatigue among Pilots in South East Asia

Since commercial aviation started, fatigue among pilots and aircrew has been acknowledged as a human factor safety issue. This survey was conducted between September and December 2009 among airlines pilots. The three main objectives of this study are: to identify sleep patterns, their promoting and interfering factors of airlines pilots. This survey results revealed that most of the pilots do not have any problem to get to sleep and majority of them had never taken any sleeping aids, such as: alcohol or medication. The five sleep interfering factors, which include environmental (i.e. heat, noise and lighting) and physiological (i.e. nature’s call and personal worries) were investigated in this survey. It was found out that personal worries top the list. From this study, it can be concluded that fatigue issue is significant among South East Asian airlines pilot.

Google Forms for Students’ and Teachers’ Self Reflection Practices

The paper looks at how Google docs (forms) were used to collect feedbacks from students in Sociolinguistics classes. Feedbacks collected are on lessons conducted in the classroom. During the set induction and closure of each lesson, students were taught moral values directly through short stories delivered or videos carefully chosen by the lecturer to suit the Kemahiran Insaniah items in Learning Outcomes Kemahiran Insaniah (LOKI) by Ministry of Higher Education (MOHE). Sociolinguistics lessons were conducted as usual. Thirty minutes before classes end, students go to a given link (http://goo.gl/forms/z23Z36YWvZ) using either their laptops or smart phones to answer six (6) questions; one which rates their understanding of the lesson taught, and two questions allow students to reflect on what they have learnt, found most interesting or uninteresting, and they are free to write down their thoughts. Students found typing their responses into Google forms using their smart phones to be easier; and with Google forms, their responses were directly sent to a spreadsheet for easy analysis; and were automatically saved and stored on lecturer’s Google drive. The lecturer gets to monitor students’ understanding and read the summary of responses and reflect on his teaching practices in the classroom. Many decisions can be made from the reflections done by both students and lecturer; for example students reinforced what has been taught to them and lecturer gets to improvise teaching methodology and be aware of students’ differences and accommodate them. After five (5) lessons, it was found that students do remember the moral values inculcated directly to them as most of them wrote about the values in their responses. Additionally, Google forms proved to be a very convenient tool for reflective practices (as compared to students writing their reflections on pieces of paper or diary) in gathering information on what happens in the classroom from the students, as well as it is fast, plus it is free and easy to use web-based application.