Water Network Optimization with Wastewater Regeneration Models

The conventional water network synthesis approach greatly simplifies wastewater treatment units by using fixed recoveries, creating a gap for their applicability to industrial processes. This work describes a unifying approach combining various technologies capable of removing all the major types of contaminants through the use of more realistic models. The following improvements are made over the typical superstructure-based water network models. First, unit-specific shortcut models are developed in place of the fixed contaminant removal model to describe contaminant mass transfer in wastewater treatment units. Shortcut wastewater treatment cost functions are also incorporated into the model. In addition, uncertainty in mass load of contaminants is considered to account for the range of operating conditions. Furthermore, the superstructure is modified to accommodate realistic potential structures. We present a modified Lagrangean-based decomposition algorithm in order to solve the resulting nonconvex mixed-integer nonlinear programming (MINLP) problem efficiently. Several examples are presented to illustrate the effectiveness and limitations of the algorithm for obtaining the global optimal solutions.The authors would like to acknowledge financial support from the National Science Foundation for financial support under grant CBET-1437668, the program “Estancias de movilidad en el extranjero “Jose Castillejo” para jóvenes doctores” (JC2011-0051) of the Spanish Ministerio de Educación, and from the University of Alicante (GRE11-19)

Ergonomic interventions: comparisons between footrest and anti-fatigue mat in reducing lower leg muscle discomforts during prolonged standing

Ergonomics is a science focusing on the study of human fit, decreasing human fatigue and discomfort through the design of new product. Prevention related to workers injury and illness such as muscle discomfort is part of the main goals in ergonomics interventions. Thus, this present study investigates the effectiveness of ergonomic interventions such as footrest and floor conditions in reducing workers lower leg muscle discomforts during prolonged standing. The main objective of this study was to determine and compare the lower leg muscles discomfort (exertion percentage (%)) of Gastrocnemius and Tibialis Anterior among the respondents using the two ergonomic interventions (footrest and anti-fatigue mat). About 60 healthy subjects were recruited to stand for 2 hours (120 minutes) while using the two interventions in different session with one week interval between each test session. During standing, lower leg muscle discomfort of Gastrocnemius and Tibialis Anterior muscles were continuously monitored. Changes in lower leg muscle discomforts over standing time were measured using the surface Electromyography (sEMG). In this study, the sEMG readings showed that the percentage of exertion (%) were increasing with time (within 120 minutes) on muscles for both legs with the usage of the interventions (footrest and anti-fatigue mat). However, the percentage of exertion (%) from the sEMG readings were lower compared to previous studies. The independent t-test was used to find the mean changes on exertion percentage (%) between each muscles of both legs for the two interventions. Results found that there were significant exertion percentage at certain time with 15 minutes time period within the 120 minutes standing. This study showed that the ergonomic interventions (anti-fatigue mat and footrest) gives a low number of exertion percentage (%), showing a reduced muscle discomfort to the lower leg muscles compared to previous studies and interventions. In comparisons with footrest, this study showed that anti-fatigue mat is more applicable for the assembly workers in the industrial factory. The data produced by the comparisons between the two interventions can be useful especially to the Department of Occupational Safety and Health Malaysia (DOSH) in enhancing the safety and wellbeing of industrial workers in Malaysia

Health care workers safety: screening and immunization: a review

The paper puts forth the need for health care workers safety whilst undertaking their job on a daily basis. Presently there are number of factors that are directly linked to the safety of health care workers. However, Occupational Health is very important and useful for health workers that are exposed to their job hazards. Every year, many lives are lost because of the spread of infections in hospitals. Every hospital’s occupational health departments should ensure that all new staff are vaccinated to protect them against microorganisms carried by other patients, and with vaccinated against preventable diseases. This will help to prevent the health workers from occupational exposure to patients’ blood or any other bodily substances, including injury from sharp objects, and also guarantees that the new employees does not infect the patients with infectious diseases. Furthermore, all the new staff should be screened for blood borne pathogenic diseases

Conceptual design and prototype of smart calling system research

This study is conducted with the intention of designing, developing and testing a prototype of a Smart Calling System for Mechanical Engineering Department (MED) in Polytechnic Sultan Azlan Shah (PSAS), Behrang Perak. The MED building is consists of 3 floors of staff offices, 4 floors of classrooms and a total of 1388 students. As this involves a large number of students, there is a frequent movement of students flow into the department office to meet their relevant lecturers. The current communication method in MED which is using telephone and PA system is not very effective and has created an unpleasant environment in the staff s office. Therefore the objective of this study is to develop a Smart Calling System for the communication purpose in the MED offices. This study was planned based on the Design Process Model (DPM) activity. Results of the developed prototype showed that it provides a better communication tool between the lecturers and students

Vibration exposure and work-musculoskeletal disorders among traffic police riders in Malaysia: a review

Background: The traffic police force is one of the occupations that utilize motorcycles as the main mode of transport. The main ergonomic hazard with the constant use of motorcycles is exposure of riders to vibration while riding their motorcycles, which can potentially lead to work.related musculoskeletal disorders (WMSDs). Objective: This review is meant to provide an overview of the available vibration exposure with WMSDs for traffic police riders and to review the related guidelines. Method: This study involved comprehensive search of database from 1945 to 2015. Published research paper that reported on the vibration exposure, prevalence, and/or risk factors of WMSDs and occupational riders were assessed and reviewed. Result: The review suggests that the main factors involving vibration in motorcycles come from the motorcycles itself, the posture of the hands and arms during the gripping of the handlebars, the surrounding environment, and the period of riding motorcycles. Majority of the studies agreed that police riders had higher percentage of WMSDs especially in lower back, neck, and shoulder. Conclusion: Overall, police riders have a high incidence of WMSDs, which in combination with exposure to vibrations with prolonged sitting and static posture may increase their susceptibility to WMSDs. Further research is required to explore the level of exposure to vibrations and WMSDs among traffic police riders, its potentially consequences, and ways to reduce exposure and risk associated with vibrations and WMSDs

Prevalence of safety equipment and helmet use among school students commuting to school in South Selangor, Malaysia

A cross-sectional observational study was conducted on the use of helmets and other safety equipment for child pillion riders while going to a school in Sri Serdang, Selangor, Malaysia. The objective of this study was to analyze and report the proportion of children wearing helmets and other safety equipment while riding pillion on a motorcycle. The prevalence of helmet use among the students as pillion riders was low (47.88%) compared to the adults (75.21%). This was unsatisfactory. There is a distinct lack of awareness of the benefits of helmets in helping to save lives and reducing injuries. Hence, there is a need for other safety equipment to provide additional safety protection for child pillion riders to counter the lack of safety equipment use while riding pillion. The Malaysian Ministry of Transport could benefit from this study with the information gained for safety equipment use among school students

High-powered police motorcycle: muscle discomfort among Malaysian traffic police riders

Discomfort due to riding a motorcycle is an issue that need to be addressed as it has long-term effects of musculoskeletal disorders on motorcyclists especially among occupational motorcyclist. Thus, this study was conducted to analyse the rating of muscle discomfort and correlation with the risk factors among traffic police riders. A cross-sectional study was carried out among 137 male traffic police riders (high-powered motorcycle) with the age between 20 to 39 years old. The 100-mm visual analogue scale questionnaire included ratings of perceived discomfort scales for 20 specific body regions was used in the study. The results indicate that the lower back (left and right) were the highest mean of discomfort which were 56.6 mm and 55.9 mm respectively. This followed with right (48.5±36.2 mm) and left (48.4±30.3 mm) upper back, and right hand (47.0±33.0 mm). The mean of overall discomfort ratings for all regions were more than 20 mm. Besides, there is a strong positive significant correlation between duration of ridings (hours) and overall discomfort ratings (p<0.01, r=0.785) and moderate positive correlation between year of traffic police motorcycle riding experience and overall discomfort ratings (p<0.01, r=0.410). As a conclusion, cumulative riding hours, riding experience and no support of the back area of the body in motorcycle seat, are the most concern in this study as this are the contributing factors to the muscle discomfort among traffic police riders while riding high-powered motorcycle. Thus, this study suggested an additional feature is needed in current motorcycle design in order to enhance comforts of traffic police riders. Also, it will improve the condition of traffic police riders’ discomfort and indirectly also improve their work and health performance as well as productivity