831 research outputs found
UTHM water quality classification based on sub index
River or stream at their source is unpolluted, but as water flow downstream, the river or lake is receiving point and non-point pollutant source. Ammoniacal nitrogen (NH3- N) and suspended solids (SS) strongly influences the dynamics of the dissolved oxygen in the water. Studies on monitoring this parameter were conducted for a river or lake but limited to the small man-made lake. This study is initiate to determine the changes in water quality of UTHM watershed as the water flows from upstream to downstream. The monitoring of NH3-N and TSS were monitored at two sampling schemes, 1) at the two-week interval and, 2) at a daily basis followed by the determination of the water quality sub-index particularly SIAN and SISS. The results showed that the two lakes in UTHM watershed were classified as polluted. In conclusion, the remedial action should be implemented to improve the water quality to meet the requirements at least to meet the recreational purpose
Minimal model for beta relaxation in viscous liquids
Contrasts between beta relaxation in equilibrium viscous liquids and glasses
are rationalized in terms of a double-well potential model with
structure-dependent asymmetry, assuming structure is described by a single
order parameter. The model is tested for tripropylene glycol where it accounts
for the hysteresis of the dielectric beta loss peak frequency and magnitude
during cooling and reheating through the glass transition.Comment: Phys. Rev. Lett. (in press
Mechanical properties of old concrete—UHPFC interface
The uniqueness of Ultra-High Performance Fiber Concrete (UHPFC) is its extremely low porosity gives its low permeability and high durability, making it potentially suitable for rehabilitation and retrofitting reinforced concrete structures or for use as a new construction material. This experimental study was performed to assess the bond strength between UHPFC as a repair material and Normal Concrete (NC) substrate as an old material; split tensile strength and slant shear tests were performed to quantify the bond strength in indirect tension and shear respectively, also the correlation between split tensile strength and slant shear were studied. The result showed that UHPFC has been cured by steam, gives high bond strength at the early age of the repair process, and interacts well with the surface of NC, as a result the failure occurred mostly in the NC substrate. A good correlation between the slant shear test results and the split tensile test results has been observed
Gasification of oil palm empty fruit bunches (OPEFB) briquettes for bio-syngas production
Gasification of Oil Palm Empty Fruit Bunches (OPEFB) briquettes was investigated in an air blown 4.5 kW allothermal fluidized bed gasifier to examine the effects of bed temperature (600-800 °C) and equivalence ratio (λ = 0.25) on bio-syngas yield and composition. In addition, physicochemical and thermochemical characterization of the fuel properties of the OPEFB briquettes were also examined. The results demonstrate that pelletization improved the solid biomass fuel (SBF) properties of OPEFB including moisture content and higher heating value (HHV). The gasification of OPEFB briquettes produced bio-syngas comprising H2, CO, CO2, CH4 as well as solid biochar with a HHV higher than the original OPEFB briquettes. The highest yield of H2 was obtained at 600 °C while HHV of the bio-syngas was within the range 4-8 MJ/Nm3 for air gasification in fluidized bed gasifiers. In addition, agglomeration of bed materials did not occur during OPEFB briquettes gasification despite its high bed agglomeration potential (BAP). In conclusion, the gasification of OPEFB briquettes into bio-syngas and biochar is a practical route for bioenergy production in Malaysia
Compressive Stress-Strain Behavior of Composite Ordinary and Reactive Powder Concrete
The deterioration of reinforced concrete structures is a major social problem. To minimize this problem and ensure effective structural management, the number and extent of repair interventions must be kept at the lowest probable level. Good bond is one of the main requirements for successful repair. The main aim of this study was to investigate the compressive stress-strain behaviour of the composite specimens consist of ordinary concrete (OC) substrate as old concrete and reactive powder concrete (RPC) as a retrofitting material, by using different types of OC substrate surface preparation methods. The results showed that the composite OC/RPC specimens were able to behave closely to individual OC, in the case of using OC substrate with surface prepared by sand blasted
The relationship between substrate roughness parameters and bond strength of ultra high-performance fiber concrete
The bonding that exists between the old concrete and the new concrete depends largely on the quality of substrate surface preparation. The accurate representation of substrate surface roughness can help determine very precisely the correct bonding behavior. In this work, an experimental investigation was carried out to quantify the normal concrete (NC) substrate roughness parameters and evaluate their relationship with the bonding performance of ultra high-performance fiber concrete (UHPFC), used as a repair material. The bond strength was quantified based on the results of the pull-off test, splitting cylinder tensile test, and the slant shear test. Three types of NC substrate surface preparation were used: as-cast (without surface preparation) as reference, wire-brushed, and sand-blasted (SB); the roughness of which was determined using an optical three-dimensional (3D) surface metrology device (Alicona
Utilization of ultra-high performance fibre concrete (UHPFC) for rehabilitation–a review
Under normal circumstances, reinforced concrete structures (RCS) show excellent performance in terms of durability and structural behaviour except for the zones that are subjected to severe mechanical or cyclic loading and aggressive environmental conditions. Therefore the methods of rehabilitation or strengthening of these zones should be reliable, effective and economical. Today, many scientists, academics and engineers understood the extremely low porosity and low permeability characteristics of ultra high performance fibre concrete (UHPFC) giving its enhanced durability over high performance concrete (HPC), thus making it potentially suitable for rehabilitation and retrofitting problematic RCS. The advantages of utilising the technology of UHPFC in repairing works includes (i) decrease the working time needed for the rehabilitation works; and (ii) increase the serviceability and durability to an extent where
Graphical User Interface (GUI) Controlled Mobile Robot
The advanced design and development of robotic technology in producing multi task are
increasingly. In this paper presents about designing and developing mobile robot model that can be
controlled using Graphical User Interface (GUI) via wireless protocol. This paper focuses on the
control mobile robot by using the GUI as navigation control and the user can get a view an image and
real time video on visual basic software. To address the problem of sired based control, XBee wireless
communication circuit was used in mobile robot through a computer command. The development of
this mobile robot consists of a chassis, a graphical user interface (GUI), XBee module, DC gear motor,
camera, track wheels and microcontroller type PIC18F4550. Differential driving method using L298
circuit was used to control movement of the robot. In mechanical design, the wheel track has been used
instead of conventional wheels to enable the robot to travel through different types of surfaces or rough
terrain. In addition, wireless cameras was attached to the robot as a system of monitoring function.
Finally, the robot will be designed to control wireless remote control that can control robots. Wireless
remote control allows the user of an environment that is unsafe or dangerous device and evades wires
or cables interfere with the movement of the robot
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New Thermal Taste Actuation Technology for Future Multisensory Virtual Reality and Internet
Today’s virtual reality (VR) applications are mainly based on audio, visual, and haptic interactions between human and virtual world. Integrating the sense of taste into VR is difficult since we are dependent on chemical-based taste delivery systems. Therefore, developing a proper non-chemical digital taste actuation technology can unlock taste experiences in VR applications such as gaming, multisensory entertainment, remote dining, and online shopping. This paper presents the ‘Thermal Taste Machine’, a new digital taste actuation technology that can effectively produce and modify thermal taste sensations on the tongue. This device changes the temperature of the surface of the tongue within a short period of time (from 25 ◦ C to 40 ◦ C while heating and from 25 ◦ C to 10 ◦ C while cooling). We tested this device on human subjects and described the experience of thermal taste using 20 known (taste and non-taste) sensations. Our results suggested that rapidly heating the tongue produce sweetness, fatty/oiliness, electric taste, warmness, and reduced the sensibility for metallic taste. Similarly, participants reported that the cooling the tongue produced mint taste, pleasantness, and coldness. By conducting an another user study on the perceived sweetness of sucrose solutions after the thermal stimulation, we found that heating the tongue significantly enhanced the intensity of sweetness for both thermal tasters and non-thermal tasters. Also, we found that faster temperature rise on the tongue produce more intense sweet sensations for thermal tasters. We believe that this technology will be useful in two ways: First, it can produce taste sensations without using chemicals for the individuals who are sensitive to thermal taste. Second, the temperature rise of the device can be used as a way to enhance the intensity of sweetness. We believe that this technology can be used to digitally produce and enhance taste sensations in future virtual reality applications. The key novelties of this paper are as follows: 1. Development of a thermal taste actuation technology for stimulating the human taste receptors, 2. Characterization of the thermal taste produced by the device based on a set of taste related sensations and non-taste related sensations, 3. Research on enhancing the intensity for sucrose using thermal stimulation, 4. Research on how different speeds of heating affect the intensity of sweetness produced by thermal stimulation
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