The present study deals with the sound absorption performance of natural fibres from the oil palm frond (OPF), mainly considered agricultural waste. Therefore, this study aimed to investigate the sound absorption performance of OPF fibre-reinforced composite under normal incidence sound. The materials used were OPF particles and urea-formaldehyde was used as an adhesive. The particleboards were produced with three particle sizes and four target densities. The absorption coefficient of normal incidence sound (α_n) was tested using an impedance tube. The effects of particle size and bulk density were also evaluated. The findings reveal thatα_n exceeded 0.45 at 1000 Hz and could reach 0.95 above 3.3 kHz. This occurred when the bulk density of the OPF composite particleboards ranged between 0.3–0.4 g/cm³, and the particle size varied between medium to coarse. The results also indicated that the absorption frequency and the degree of α_n significantly increased as the bulk density decreased. Therefore, OPF fibres can be used to create sound-absorbing composite particleboards.

An early detection control system for high-speed and objectivity welding defects is needed. Visual Inspection (VT) is an important method and the initial stage before a welded material will be tested at destructive testing. So far, VT has only used human vision, which takes a protracted process and is highly subjective. This paper will contribute to the VT method to control the Friction Stir Welding (FSW) process by detecting the flash defect using image processing and Convolutional Neural Network (CNN). Thus, flash defects in the FSW process can be minimised and detected as early as possible. Image processing and CNN serve as a substitute for human vision. The selection of CNN is considered suitable for detecting an image because the process is fast and detects key features without human supervision, which is carried out by a continuous learning process. 620 images from the FSW process were processed into two groups of datasets. It was processed with two types of CNN architecture, including AlexNet and VGG16. Based on the VT results by CNN, the AlexNet model showed a detection accuracy of 91.03%, while the VGG16 model showed a detection accuracy of 77.35%. From these results, CNN’s success in conducting VT on FSW process control is relatively high and can play a more significant role in checking the results of the FSW process. Therefore, the possibility of flash defects can be minimised and detected as early as possible.

Bicycles are one of the sports equipment as well as a mode of transportation that is environmentally friendly, when using a bicycle, all members of the body perform movements. In this study, a tricycle with a delta concept was made, that is 2 wheels behind and 1 wheel in front. This bike is designed to help stroke sufferers perform physical rehabilitation independently by pedaling a bicycle. To find out the benefits of bicycles to help cure strokes, especially the legs of the patient, a stroke test were carried out for 1 month (30 days) by 4 stroke patients, who were the respondents in this research. Each respondent pedaled the bike once every 3 days, so the amount of therapy became 9 times a month for each respondent. During pedaling respondents vital sign was recorded, the value of heart recovery rate (HRR) and amount of energy consumption were calculated. To find out the usefulness of bicycle therapy for stroke patients, 4 stroke sufferers were also selected who were doing stroke rehabilitation as respondents in this research, but did not pedal a bicycle. Furthermore, all respondents, whether bicycle therapy or not, performed a fitness test using the six minute walking test (6-MWT) test method. The method is used to determine the maximum oxygen volume capacity (VO2 max) of a person who walks on a certain path for 6 minutes. From the test, it can be seen that the distance taken by the respondent after walking for 6 minutes. The distance traveled is converted in the form of VO2 Max capacity. The test results shows that respondent therapy using a bicycle has a significant increase in body fitness, compared to respondent therapy without using a bicycle.

The purpose of this research is to develop procedures for using a tricycle bike to conduct the physical rehabilitation for stroke patients. The procedure needed to complete the design of the bike for post-stroke patients, so the bike as therapeutic tools can be utilized properly by therapists to help stroke patients recover their health. The procedure is based on standard stroke therapy procedures commonly performed in public hospitals in Indonesia. The procedure includes instructions ranging from the early stages of examination, bicycle pedal activities to fitness examinations of patients undergoing therapy. Examination of the patient’s health condition includes examining heart rate, intensity of breath, examination of muscle strength and postural scale stroke patients. If the patients already meet this initial inspection, then the patient is allowed to test the bike. The patient’s condition inspection performed again after the completion of the paddle test. During the paddle test some important things, namely: the amount of sucking oxygen (VO2 max), heart rate, and a paddle speed are documented. As an example of the application procedure, 6 people stoke patients are chosed as respondents for cycling test. The respondent are susc as A, B, C, D, E and F. All respondents are stroke patients above 50 years. Respondents A, B, and C therapy 3 times a week, while respondents D, E, and F do therapy every 10 days in 1 month. After 30 days of therapy pedal, it can be seen that the respondent A, B, C VO2max increased significantly compared to respondents’ D, E, and F. The increase in the number of sucking the oxygen is proportional to the energy pedal that can be issued by the respondent. These means the procedures were arranged can be used as a guide to physical therapy stroke patients using tricycle bike.

According to the survey to the wheelchair users in Surabaya, it is found that 70% of the respondents want to have activities inside or outside their home independently. Therefore, a wheelchair that can satisfy their requirements is on demand. In this research we used an integrated product development to design a wheelchair. We simulated the ergonomic design by a method so called RULA for static load 150 kg. This proposed wheelchair is an ergonomic wheelchair. It is a wheelchair, that satisfies the safety regulations. By using a joystick, a user can control the wheelchair to move forward and backward, to set the seat up and down as convenience as they want to. We hope that this wheelchair can help the physical handicaps to move more freely and have more activities than before. Abstract in Bahasa Indonesia : Hasil kuisioner yang disebarkan ke pemakai kursi roda di kota Surabaya pada akhir 2005 dan awal 2006 menunjukkan bahwa 70% reponden tidak menginginkan lagi didampingi oleh seorang pemandu para saat mereka beraktifitas di dalam maupun di luar rumah. Sehingga, sebagai transportasi yang sangat dibutuhkan oleh penderita cacat kaki, kursi roda perlu untuk dikembangkan berdasarkan permintaan dan keinginan mereka. Pada makalah ini akan dipaparkan metode pengembangkan kursi roda yang didasarkan pada metode pengembangan produk terintegrasi. Melalui analisa kekuatan material pada beban statis 150 kg dan simulasi kenyamanan dengan metode RULA, dapat dirancang sebuah kursi roda yang aman dan nyaman, dapat bergerak maju mundur, tempat duduk dapat naik turun serta seluruh gerakannya dikontrol sendiri oleh pemakai kursi roda. Pengembangan kursi roda ini diharapkan dapat meningkatkan ruang gerak penderita cacat kaki dalam beraktifitas. Kata kunci: kursi roda, transportasi, aman, nyaman, simulasi, RULA.