Critical gap analysis of merging sections at Kuala Lumpur middle ring road

At merging sections, drivers normally slow down and sometimes need to stop while seeking a suitable gap before merging with the mainstream. Thus, there will always be several observed rejected gaps and an accepted gap which can be used to determine the smallest average gap, so-called critical gap. This study was carried out to determine critical gap values at selected merging sections at the Jalan Tun Razak and the DUKE Expressway uses the Maximum Likelihood method. Data were collected by using videotaping method and the gap acceptance data were extracted for analysis. A gap acceptance event at highway merging sections in this study was redefined due to unavailability of stopping vehicles at the ramp junction. Therefore, the gap data were estimated starting from a ramp’s vehicle passing the end of gore marking to where it merges with the mainstream. The analysis of the critical gap takes into consideration accepted gaps greater than 5 seconds to avoid forced entry due to lead impedance of successive vehicles on mainstream. The critical gap values obtained in this study, according to vehicle classification were ranged between 4.5 to 5.0 seconds, which are slightly smaller if compared to critical gap values for particularly left turn from minor movement at priority junction of the Arahan Teknik (Jalan) 11/87 and the United States Highway Capacity Manual 2000. The findings shall help to study driving behavior of local drivers, especially at priority control facilities such as merging sections

Preventive and curative activity of garlic extract on gentamicin-induced oxidative stress

Background: Nephrotoxicity is a serious side effect of using gentamicin. Garlic is an important component in the complementary medicine. The aim of this study was to find out whether garlic has ameliorative effects on gentamicin-induced nephrotoxicity. Methods: 50 male Wistar rats were divided into 5 groups of 10; I: They kept in the same condition as others without receiving any drug for 10 days and then sacrificed. II: Rats in this group were injected intraperitoneally (i.p.) with 100 mg/kg of gentamicin for 10 consecutive days and then sacrificed. Group III: Rats in this group received garlic juice 20 mg/kg intraperitoneally for 10 days and then sacrificed. IV: Rats in this group received gentamicin for 10 days, then received 20 mg/kg garlic intraperitoneally for the next 10 days and then sacrificed on day 20th. V: Rats in this group received a combination of intraperitoneal gentamicin and garlic 20 mg/kg for 10 days and then sacrificed. Serum blood urea nitrogen (BUN) and creatinine (Cr) were measured and the kidneys were processed for histopathological examinations. All specimens were examined for morphologic parameters involving tubular cells. Findings: The post administration of garlic after gentamicin treatment potentially attenuated the serum levels of BUN and Cr. The pathology damage scores indicated that post administration of garlic after 10 days of gentamicin treatment attenuated the damage score significantly. Conclusion: We concluded that garlic is a nephroprotective drug to attenuate tubular injury by gentamicin

An Electronically Reconfigurable Patch Antenna Design for Polarization Diversity with Fixed Resonant Frequency

In this paper, an electronically polarization reconfigurable circular patch antenna with fixed resonant frequency operating at Wireless Local Area Network (WLAN) frequency band (2.4-2.48 GHz) is presented. The structure of the proposed design consists of a circular patch as a radiating element fed by coaxial probe, cooperated with four equal-length slits etched on the edge along x-axis and y-axis. A total of four switches was used and embedded across the slits at specific locations, thus controlled the length of the slits. By activating and deactivating the switches (ON and OFF) across the slits, the current on the patch is changed, thus modifying the electric field and polarization of the antenna. Consequently, the polarization excited by the proposed antenna can be switched into three types, either linear polarization, left-hand circular polarization or right-hand circular polarization. This paper proposes a simple approach that able to switch the polarizations and excited at the same operating frequency. Simulated and measured results of ideal case (using copper strip switches) and real case (using PIN diode switches) are compared and presented to demonstrate the performance of the antenna

Degradation Of Methylene Blue Using CuO Prepared Using Conventional Solid State Method

The degradation of methylene blue (MB) dye onto copper oxide (CuO) synthesized using solid state method was investigated in a batch adsorption process. Copper Oxide (CuO) was successfully synthesized using solid state synthesis which involves heat treatment with temperatures ranging from 400 oC to 600 oC. The optimum preparation temperature was 600 oC resulting in 8.5% MB removal. XRD analysis shows that the crystal system of CuO is a monoclinic system and therefore all the diffraction peaks has been indexed using the CuO monoclinic phase. The obtained parameters were a = 4.6860 Å, b = 3.4280 Å, c = 5.1330 Å with a volume cell of 81.84 Å3. SEM analysis indicates that a standard particle size for CuO is 37.0μm and that it has irregular surface. The effect of initial dye concentration (100 ppm-600 ppm), contact time (24-48 hours) and solution temperature (30 ⁰C) were also evaluated. Highest removal percentage of MB was observed in MB concentration of 600 ppm. A longer contact time of 48 hours was shown to be more effective than 24 hours. The adsorption of MB onto CuO has higher efficiency at larger concentration difference, longer contact time and higher temperature used during synthesizing CuO

Role of membrane surface charge and complexation-ultrafiltration for heavy metals removal: a mini review

Membrane technology is a promising water purification unit operation from household use to industrial application owing to its simplicity of operation, efficient recovery and minimum need for chemical and space allocation. Due to that reason, study on the membrane applications have becoming more popular among scientific community nowadays and one of the applications is removal of heavy metal using ultrafiltration (UF). However, a stand-alone UF will be not able to carry out the removal of heavy metals effectively. Certain modification is required in order to enhance its rejection via unique facilitated mechanism. Thus in this review, role of surface charge interaction as well as the method of complexation-ultrafiltration were discussed

The squared Commutativity degree of dihedral groups

The commutativity degree of a finite group is the probability that a random pair of elements in the group commute. Furthermore, the n-th power commutativity degree of a group is a generalization of the commutativity degree of a group which is defined as the probability that the n-th power of a random pair of elements in the group commute. In this paper, the n-th power commutativity degree for some dihedral groups is computed for the case n equal to 2, called the squared commutativity degree

Finite Element Analysis and Vibration Testing of a Simple Replicate Beam-Type Aircraft Wing with and without Secondary Structure Attached

Ground vibration testing (GVT) is one of the most critical testing procedures for an airplane certification. With proper GVT, analysts can determine the stiffness distribution, natural frequencies, mode shapes and structural damping of each airplane components which are needed for flutter analysis and dynamic loads analysis. Hence the results from GVT are highly important. The problem identified in this paper is one that misleads the structural designing and might result in catastrophic situations, if proper attention is not given to the GVT results. During GVT, technicians and engineers attempt to instrument most of the primary components of the airplane, totally avoiding secondary structures such as bungees, gears, control surfaces, etc. The secondary structures are also of equal importance as the primary structures so that analysts can identify the in-phase and out-of- phase modes. If not, the tuning of the stiffness of the primary structure might not be accurate for flutter analysis, especially when the in-phase and out-of-phase modes are near to the structural modes of the primary structure. The goal of this paper is to recreate the above mentioned problem of the in-phase and out-of-phase mode for a small wing-gear like structure. The detailed objectives and methodologies of the work include, simulating the modal experiments and finite element analysis (FEA) on a free-free beam (primary structure) with and without flexible links (secondary structure) attached to them, determining the stiffness distribution and modal characteristics of the primary structure and the secondary structures, using GVT and FEA. Characterizing the in-phase and out-of- phase modes which involves both primary and secondary structure by signal processing and using simplified beam model (stick model) is another important goal of this research

Aktivitas Siswa dalam Proses Pembelajaran Fisika dengan Menggunakan Model Pembelajaran Inkuiri Terbimbing (Guided Inquiry)

The purpose of this study is to observe how the student activity is, student learning outcomes, and students' response to the teacher's implemented activity in learning process by using a guided inquiry learning model. The subject is 20 science students in third grade in Islamic Senior High School Darussalam. This study is a qualitative descriptive with descriptive statistics approach. Technique of data collection is done through tests, observation sheet of teachers and students activities, and questionnaires. The data is processed using a statistical percentage. Based on the results of data analysis, they show that there are increased activities of students using guided inquiry learning model. They can be seen from the average percentage which increases; at the first meeting is 84.21%, the second meeting is 88, 16%, and the third meeting is 94, 08%. Besides, student learning outcomes increase from the first to third meeting; the percentage of the first meeting is 70%, the second meeting is 75% and the third meeting is 85%. Eventually, the students' response to the teacher's implemented activity in the learning process of Physics by using guided inquiry learning model during the three meetings is very good. That is because the use of guided inquiry learning model can improve students activity and students learning outcomes in Rectilinear Motion material, therefore it is recommended to be used for other relevant materials