Influence Of Engineered Soil Media Composition To The Hydraulic Performance In Rain Garden System

Stormwater had been identified as one of the factor that causes surface runoff on the ground. The runoff is caused by the inability of the water to infiltrate into the soil, causing the water to stay on the ground and causes major problems such as flooding and water ponds. Rain garden is one of the best management practice approach in handling this matter. A rain garden promotes infiltration to the soil beneath, reducing the surface runoff thus solving floods problems. The objective of this study is to investigate the effects of soil media composition to the hydraulic performance in a rain garden system. Three types of soil media composition is used, which are fine river sand, coarse river sand, and leaf composts, which are made up of shredded dry leaves. The study is done by using sand column to represent a bioretention system, which are divided into three layers; the drainage layer, soil filter layer and ponding layer at the top. In order to analyse the hydraulic performance of the system, a few parameters had been identified as indicators in this study, which are the flow of water, soil hydraulic conductivity, water removal efficiency, and water holding capacity. A coarser grain material had been known to give a greater flow and hydraulic conductivity, however, an addition of fine sand and leaf composts helps in water removal and water drainage, which is also a good parameter for a better rain garden system. Keywords: rain garden, best management practice, hydraulic conductivity, soil media composition, water removal efficienc

Super slim multiband inverted-F antenna for GSM/DCS/PCS operation

This paper presents the design of a super slim multiband wrapped inverted-F antenna that covers the frequency bands allocated for GSM, DCS and PCS wireless services. In the first step, the quarter-wavelength size (at 850 MHz) open-end arm of an inverted-F radiator is folded and meandered. Then the antenna is wrapped using a fourth-order folding technique to reduce its projection area to only 40 x 10 x 3mm. Full wave EM simulations show that the antenna excites a lower mode resonance at about 850MHz and a higher one at about 1900MHz. Its radiation pattern is nearly omni-directional with a gain of about 2.5dBi at the lower band and 4.6dBi at the upper band. A prototype of the proposed antenna is fabricated and tested. A close agreement between simulated and measured result is achieved. The measured 6-dB return loss or VSWR 3:1 bandwidths for the lower and upper resonances are 200MHz (770 to 970 MHz) and 280MHz (1710 to 1990 MHz) respectively. These bandwidths are sufficient to cover GSM 850/900/1800/1900MHz, DCS 1800MHz and PCS 1900MHz bands. Because of its compact volume the proposed antenna is a very attractive candidate for modern slim size portable transceivers

Wet-spinning of PEDOT:PSS/functionalized-SWNTs composite: A facile route toward production of strong and highly conducting multifunctional fibers

With the aim of fabricating multifunctional fibers with enhanced mechanical properties, electrical conductivity and electrochemical performance, we develop wet-spinning of composite formulation based on functionalized PEG-SWNT and PEDOT:PSS. The method of addition and loading are directly correlated to the quality and the ease of spinnability of the formulation and to the mechanical and electrical properties of the resultant fibers. Both the fiber modulus (Y) and strength (σ) scaled linearly with PEG-SWNT volume fraction (Vf). A remarkable reinforcement rate of dY/dVf = 417 GPa and dσ/dVf = 4 GPa were obtained when PEG-SWNTs at Vf ≤ 0.02. Further increase of PEG-SWNTs loading (i.e. up to Vf 0.12) resulted in further enhancements up to 22.8 GPa and 254 MPa in Modulus and ultimate stress, respectively. We also show the enhancement of electrochemical supercapacitor performance of composite fibers. These outstanding mechanical, electrical and electrochemical performances place these fibers among the best performing multifunctional composite fibers

Influence Of Engineered Soil Media Composition To The Hydraulic Performance In Rain Garden System

Stormwater had been identified as one of the factor that causes surface runoff on the ground. The runoff is caused by the inability of the water to infiltrate into the soil, causing the water to stay on the ground and causes major problems such as flooding and water ponds. Rain garden is one of the best management practice approach in handling this matter. A rain garden promotes infiltration to the soil beneath, reducing the surface runoff thus solving floods problems. The objective of this study is to investigate the effects of soil media composition to the hydraulic performance in a rain garden system. Three types of soil media composition is used, which are fine river sand, coarse river sand, and leaf composts, which are made up of shredded dry leaves. The study is done by using sand column to represent a bioretention system, which are divided into three layers; the drainage layer, soil filter layer and ponding layer at the top. In order to analyse the hydraulic performance of the system, a few parameters had been identified as indicators in this study, which are the flow of water, soil hydraulic conductivity, water removal efficiency, and water holding capacity. A coarser grain material had been known to give a greater flow and hydraulic conductivity, however, an addition of fine sand and leaf composts helps in water removal and water drainage, which is also a good parameter for a better rain garden system. Keywords: rain garden, best management practice, hydraulic conductivity, soil media composition, water removal efficienc

Towards the knittability of graphene oxide fibres

Recent developments in graphene oxide fibre (GO) processing include exciting demonstrations of hand woven textile structures. However, it is uncertain whether the fibres produced can meet the processing requirements of conventional textile manufacturing. This work reports for the first time the production of highly flexible and tough GO fibres that can be knitted using textile machinery. The GO fibres are made by using a dry-jet wet-spinning method, which allows drawing of the spinning solution (the GO dispersion) in several stages of the fibre spinning process. The coagulation composition and spinning conditions are evaluated in detail, which led to the production of densely packed fibres with near-circular cross-sections and highly ordered GO domains. The results are knittable GO fibres with Young\u27s modulus of ~7.9 GPa, tensile strength of ~135.8 MPa, breaking strain of ~5.9%, and toughness of ~5.7 MJ m(-3). The combination of suitable spinning method, coagulation composition, and spinning conditions led to GO fibres with remarkable toughness; the key factor in their successful knitting. This work highlights important progress in realising the full potential of GO fibres as a new class of textile

A holistic team approach (HTA) model to curb machinery accidents in power plants.

Machinery accidents have been an important aspect that needs proper attention in all work places in recent years especially power plants. A large number of accident cases have been reported from the year 2018 to 2022. Accident report from DOSH (Department of Safety and Health Malaysia) indicates that a significant number of machinery accident cases occur in power plants while PERKESO (Social Security Organisation Malaysia)has investigated and tabulated accidents based on area of workplace and injury. Research shows that most statistical studies do not comprise of a preventive model to curb machinery accidents, which involves employees and management. A model that comprises of Machinery or Area of work (M) and the type of injury (I) is identified and summed in a form of a scientific equation which results in the possible accident type (α) which is the accident occurred. A Holistic Team Approach (HTA) model is designed that involves a team for each element M and I which comprises of engineers, technicians and operators working in the same area of equipment and a management representative. Each team is assigned to specific accidents according to the M and I element and classified as α-combinations. Teams are sent for incident investigation where preventive actions and reporting are discussed. A decision analysis is performed based on the model that emphasizes two Process Safety Management (PSM) elements which are accident investigation and employee participation. The HTA model is able to reduce machinery accidents by involving the elements of machinery and injury types, which is applicable to workplaces worldwide

Elastic Fiber Supercapacitors for Wearable Energy Storage

The development of wearable devices such as smart watches, intelligent garments, and wearable health-monitoring devices calls for suitable energy storage devices which have matching mechanical properties and can provide sufficient power for a reasonable duration. Stretchable fiber-based supercapacitors are emerging as a promising candidates for this purpose because they are lightweight, flexible, have high energy and power density, and the potential for easy integration into traditional textile processes. An important characteristic that is oftentimes ignored is stretchability-fiber supercapacitors should be able to accommodate large elongation during use, endure a range of bending motions, and then revert to its original form without compromising electrical and electrochemical performance. This article summarizes the current research progress on stretchable fiber-based supercapacitors and discusses the existing challenges on material preparation and fiber-based device fabrication. This article aims to help researchers in the field to better understand the challenges related to material design and fabrication approaches of fiber-based supercapacitors, and to provide insights and guidelines toward their wearability