Development of Capacity and Level-of-Service for Uninterrupted Exclusive Motorcycle Lanes in Malaysia

In developing ASEAN countries, the key road accident problems arise from the high proportion of motorcycles in the mixed vehicle population. Considering that motorcycles are popular mode of personal travel and that they are highly numbered on the roads, the provision of exclusive motorcycle lanes is expected to reduce accidents and improve motorcycle safety. Studies have proven that segregation is the best engineering practice to save lives of motorcyclists. Acknowledging these benefits, the Malaysian government has adopted a policy to provide exclusive motorcycle facilities along its new highways and federal roads. The need to provide this special facility has brought to light the deficiencies in studies related on motorcycle traffic sciences, operations and facility design. This research initially attempts to establish the characteristics of key components of a motorcycle-traffic system in Malaysia, i.e. the motorcyclerider unit, motorcyclist space requirement and riding manner along motorcycle lane of various lane widths. Then, it seeks to establish the fundamental motorcycle speed-flow-density relationships along uninterrupted motorcycle lanes in Malaysia. This would enable the maximum motorcycle flow, critical speed and critical density at capacity conditions to be estimated. Finally the level-of-service criteria for an exclusive motorcycle lane facility would be developed, thus allowing the motorcycle design charts and tables to be produced. To understand the key components of a motorcycle-traffic system, digital recordings of motorcyclists along the existing motorcycle lanes in Malaysia were captured. Basic dimensions of a motorcycle/rider unit were directly measured. The separation distance between side-by-side motorcyclists was obtained by employing the digital recording technique. The motorcyclist operating space was then established. Three-stages of field and experimental studies was conducted to observe the motorcyclists riding manner along various lane widths from low to high volume conditions. To establish the fundamental motorcycle speed-flow-density relationships and to develop the level-of-service criteria, the aggregated data from 8 sites ranging from the stable flow to unstable conditions were plotted. A simple linear regression analysis was conducted on the motorcycle speed on motorcycle density function to obtain the best linear regression equation that describes the relationship. Once the motorcycle speed-density relationship was established, the motorcycle speed-flow and motorcycle flow-density relationships were derived. The demarcation of the level-of service boundaries for the uninterrupted exclusive motorcycle lanes was guided by the volume-capacity ratio (v/c) and service flow rates. Results of the research revealed that the small- and medium-sized type motorcycles (150 c.c. and below) are the commonly used type in Malaysia. A single static motorcyclist spans about 0.8 m wide, but requires a mean width of 1.3 m to operate. In a lane width of 1.7 m or below, motorcycle flow applies the lane or headway concept. While in lanes of width between 1.7 m and 3.4 m, the motorcycle flow adopts the space concept. This highlights that 1.7 m is the optimum lane width where motorcyclists would travel in a single file, even during low speeds and high motorcycle flow conditions. There is not enough space for faster motorcyclists to pass the slower ones within the 1.7 m motorcycle lanes. In the headway concept (W ≤ 1.7 m), capacity is reached at a maximum motorcycle flow of 3306 mc/hr/lane, corresponding to a critical speed of 13 km/hr and critical density of 235 mc/km/lane. As for the space concept (1.7 m < W ≤ 3.4 m), capacity occurs at a maximum motorcycle flow of 2207 mc/hr/m. This corresponds to a critical motorcycle speed of 13 km/hr and critical motorcycle density of 0.166 mc/m2 (or space of 6.0 m2/mc). Based on the speed-flow-density relationships and the volume-capacity ratio, the level-of-service boundaries were demarcated. Subsequently, tables and charts of maximum motorcycle flow rates related to level-ofservices for different motorcycle lane widths were developed. The outcome provides useful input in developing design guidelines for motorcycle facilities in countries with high number of motorcycles in the effort to curb motorcycle safety problems. This study is seen as an initial effort to fill the missing link in basic research of motorcycle traffic sciences, operations and facility design that existed among various land transportation facilities, thus contributing new knowledge to the field of transportation engineering

Variable Flux Profile Optimization of a High Flux Solar Simulator

A High Flux Solar Simulator (HFSS) provides artificial solar radiation using an array of high- intensity discharge lamps attached to ellipsoidal reflectors to focus their light to a point where high temperatures can be achieved. High flux solar simulators are used for solar thermal and thermochemical research. They provide high-flux radiation used for controlled lab-scaled experimentation as an alternative to concentrated solar power systems which depends on sunlight, which is intermittent. In this project, a HFSS model is developed consisting of ten 2.5 KW metal halide lamps mounted in a truncated ellipsoidal reflector with variable flux profile capability. The novel variability in flux profile is useful in achieving different ranges of temperatures with different flux profile configurations that can be used for a wide range of solar thermal, thermochemical, and photovoltaic research applications. The variation in the flux profile of the solar simulator model is achieved by changing the angle of the lamp module with respect to the target, changing the distance between the arc of the bulb and the focal point of the reflector and by varying the power of the lamps. Ray-tracing simulation software, Trace-Pro is used to analyze the variation in the flux profile with respect to the change in parameters of the solar simulator, and a relationship is determined by fitting various curve fit types, and a piecewise worked the best. This relationship is used to define the optimization model for obtaining the optimal configuration of the HFSS model using a trust-region reflective optimization method. The objective of the optimization model is to reduce the sum of the squared difference between the user-defined flux profile and the flux profile of the solar simulator model obtained by varying its parameters. Several user-defined flux profile configurations are tested. The optimization model was able to approximate the user-defined flux profile within the achievable limits of the flux profile of the solar simulator. Thus, reducing the effort in manually adjusting the parameters of the high flux solar simulator

Cardiovascular risk factor surveillance and physical activity among the Dubai population, UAE

 Background: Regular practicing of physical activity is considered to be one of the easiest and cost effective ways of improving and maintaining health, and avoiding diseases like diabetes mellitus, cardiovascular diseases, obesity and others. Purpose: The study aims to determine the prevalence of physical activity among the Dubai population and the effect of associated factors, as well as assess the knowledge, practice and attitudes of the Dubai population

Soil salinity-sodicity and land use suitability in the Fordwah Eastern Sadiqia (South) irrigated area

Soil salinity / Sodic soils / Soil classification / Soil surveys / Soil analysis / Groundwater development / Water table / Water quality / Land use / Irrigation canals / Farmer participation / Surface drainage / Subsurface drainage / Soil reclamation / Waterlogging / Pakistan / Fordwah Eastern Sadiqia / Bahawalnagar District

Detecting Spam Review through Spammer’s Behavior Analysis

Online reviews about the purchase of a product or services provided have become the main source of user opinions. To gain profit or fame usually spam reviews are written to promote or demote some target products or services. This practice is known as review spamming. In the last few years, different methods have been suggested to solve the problem of review spamming but there is still a need to introduce new spam review detection method to improve accuracy results. In this work, researchers have studied six different spammer behavioral features and analyzed the proposed spam review detection method using weight method. An experimental evaluation was conducted on a benchmark dataset and achieved 84.5% accuracy

ACUTE RESPIRATORY DISTRESS SYNDROME-A CONCISE CLINICAL REVIEW

Acute Respiratory Distress Syndrome (ARDS) is a challenging and deadly disease faced by critical care specialists. The literature concerning ARDS has been increasing for the last 12 years and there are now many options available to treat this disease. However, not all of these options work and some may even be harmful to patients. The purpose of this paper is to provide the reader with a review of the new criteria for ARDS definition and to discuss the pros and cons of the various treatment options now available

The rise and rise of neurosurgery: academic journey of a young department in a developing country

The Section of Neurosurgery, part of the Department of Surgery, and the Mind and Brain Service Line at the Aga Khan University Hospital Karachi, has come a long way since its recognition in mid-90s. Although the program itself was recognized in late 90’s and the first resident graduated in 2004, it wasn\u27t until 2008 that it assumed its current shape of a formal, structured training program. Currently it has six full-time faculty members, one part-time faculty member, two instructors, and a team of 12 residents. Following are few of the innovations introduced within the program over the last few years

Motorcyclist Braking Performance in Stopping Distance Situations.

Motorcycle braking distance is one of the main components of motorcycle stopping sight distance. Motorcycle braking performance in different situations was not consistent in published literature. This research measured the riders’ braking distances and decelerations to both unexpected and expected objects. For braking maneuvers to an expected object, 89 motorcycle riders released the accelerator and applied the brake as quickly as possible following activation of a light beside the road of both dry and wet pavements. As for an unexpected object, 16 nonalerted subjects were confronted with the need to stop for an unexpected object along the roadway. Vehicle speeds, braking distances, and average deceleration were computed for each braking maneuver. Results showed that the deceleration varied among the riders in which 90% of riders’ decelerations were at least 2.75 m/s2 under wet conditions, whereas 90% of all riders decelerated at least 3.3 m/s2 on dry pavements. Overall, the motorcycle braking distance is more than the braking distance of passenger cars. These findings suggest that in countries where motorcycles are heavily used, their roads should be investigated for provisions of adequate motorcycle stopping sight distance, especially if the roads were designed according to AASHTO guidelines

Investigation of the laxative, spasmolytic and prokinetic properties of aqueous methanol extract of Buxus sempervirens Linn (Buxaceae)

Purpose: To investigate the spasmolytic and laxative properties of Buxus sempervirens Linn (Buxaceae) in rabbits and mice.Methods: Aqueous methanol extract (AqMeBS) as well as the dichloromethane (DCMF) and aqueous (AqF) fractions of Buxus sempervirens were investigated on isolated rabbit jejunum to explore its antispasmodic effect, relative to the standard drug, verapamil. Laxative and prokinetic potentials of 250 and 500 mg/kg doses of AqMeBS extract were evaluated in mice and compared to that of negative (normal saline) and positive (carbachol) control groups. The effects of AqMeBS and carbachol were also tested in mice pretreated with atropine (10 mg/kg). Single dose, acute oral toxicity study on AqMeBS was also executed in mice at 4000, 8000 and 12000 mg/kg doses.Results: AqMeBS, DCMF and AqF significantly inhibited the rhythmic contractility of jejunum with 0.961, 0.0327 and 0.242 mg/mL, respectively, as median effective concentrations (EC50). In addition, AqMeBS, DCMF and AqF significantly relaxed the contractions due to K+, with EC50 of 1.85, 0.05 and 1.07 mg/mL, respectively. Ca2+ concentration response curves (CCRCs) were shifted to the right by AqMeBS and DCMF, in the same manner as verapamil. In the in vivo experiments, AqMeBS produced significant (p &lt; 0.0001) laxative and prokinetic effects at 250 and 500 mg/kg doses and was comparable to that of carbachol. The acute toxicity study showed that AqMeBS was associated with one mortality at the highest tested dose (12000 mg/kg).Conclusion: These results provide the pharmacological basis for the traditional use of B. sempervirens Linn as a laxative and prokinetic remedy in the management of constipation.Keywords: Buxus sempervirens, Calcium channel blocker, Prokinetic, Laxative, Spasmolyti

COVID-19: Today's Ambiguity, Tomorrow's Uncertainty and After Tomorrow's Questions

Guest Comment by Prof. Dr Hamid Yahya Hussain on the COVID-19 Pandemi