Quantitative infrared thermography resolved leakage current problem in cathodic protection system

Leakage current problem can happen in Cathodic Protection (CP) system installation. It could affect the performance of underground facilities such as piping, building structure, and earthing system. Worse can happen is rapid corrosion where disturbance to plant operation plus expensive maintenance cost. Occasionally, if it seems, tracing its root cause could be tedious. The traditional method called line current measurement is still valid effective. It involves isolating one by one of the affected underground structures. The recent methods are Close Interval Potential Survey and Pipeline Current Mapper were better and faster. On top of the mentioned method, there is a need to enhance further by synthesizing with the latest visual methods. Therefore, this paper describes research works on Infrared Thermography Quantitative (IRTQ) method as resolution of leakage current problem in CP system. The scope of study merely focuses on tracing the root cause of leakage current occurring at the CP system lube base oil plant. The results of experiment adherence to the hypothesis drawn. Consequently, res

Hemicellulose Extraction and Characterization of Rice Straw and Leucaena Leucocephala

Local production of agricultural waste is increasing. It is not fully  utilized  and  can cause an environmental issue if it is not handle wisely. Thus, it is important to increase utilization of lignocellulosic biomass by improving their added value and subsequently decrease the agriculture waste. In this study, rice straw and Leucaena leucocephala were subjected to alkali treatment (4% sodium hydroxide) with different concentration ratio of samples to sodium hydroxide (1:10 to 1:50). The physical and chemical properties of extracted hemicelluloses were studied. The yield of hemicellulose was higher from rice straw compared to Leucaena leucocephala. The chemical functional groups present in hemicellulose were confirmed by Fourier tranform infrared spectroscopy (FTIR). The surface morphology and roughness of xylan were examined by scanning electron microscopy (SEM). Keywords: rice straw, hemicellulose, sodium hydroxide, alkal

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

Estimating average daily traffic using alternative method for single carriageway road in Southern Region Malaysia

Average Annual Daily Traffic (AADT) and Average Daily Traffic (ADT) are two parameters that are commonly required by traffic engineers and road designers to design and analyse the traffic operational performance of a road segment. In Malaysia, ADT is normally used to forecast the volume of traffic in the design year as well as to design the pavement thickness. Basically, ADT can be generated using expansion factor estimates from Peak Hour Volume (PHV). Current practice in Malaysia uses an expansion of 10% to estimate ADT from PHV. This paper discusses the results of a study carried out to establish a model for estimating ADT using PHV for single carriageway road. The 24-hours traffic data were collected at 9 sites in the districts of Johor, Malaysia for the period of 14 days. The 7-days data were used to establish the model and the other 7-days data were used to validate the model. For validation purposes, the absolute percent error (APE) for each estimate of ADT obtained from the model was calculated and compared with observed ADT. The statistical test at 95% confidence level was conducted to determine the significance difference between the ADT from actual data and the estimate ADT from model. The result shows that a power-formed trend line (y=axb) suits to the observed data with the coefficient of determination of about 0.90. Validation result shows that the ADT for the model has lesser APE compared with the ADT estimated using the factoring approach. A comparison of both estimated and actual ADT values using t-Test shows that there is no significant difference between the estimated ADT using models and the actual ADT. However, the ADT estimated using the expansion factor of 10% shows the vice versa. Such a finding implies that the model obtained from this study predicts ADT accurately than the current practice

Analyzing the effect of nozzle diameter in fused deposition modeling for extruding polylactic acid using open source 3D printing

Fused deposition modeling (FDM) is one of the Rapid Prototyping (RP) technologies. The 3D Printer has been widely used in the fabrication of 3D products. One of the main issues has been to obtain a high quality for the finished parts. The present study focuses on the effect of nozzle diameter in terms of pressure drop, geometrical error as well as extrusion time. While using polylactic acid (PLA) as a material, the research was conducted using Finite Element Analysis (FEA) by manipulating the nozzle diameter, and the pressure drop along the liquefier was observed. The geometrical error and printing time were also calculated by using different nozzle diameters. Analysis shows that the diameter of the nozzle significantly affects the pressure drop along the liquefier which influences the consistency of the road width thus affecting the quality of the product’s finish. The vital aspect is minimizing the pressure drop to be as low as possible, which will lead to a good quality final product. The results from the analysis demonstrate that a 0.2 mm nozzle diameter contributes the highest pressure drop, which is not within the optimum range. In this study, by considering several factors including pressure drop, geometrical error and printing time, a 0.3 mm nozzle diameter has been suggested as being in the optimum range for extruding PLA material using open-source 3D printing. The implication of this result is valuable for a better understanding of the melt flow behavior of the PLA material and for choosing the optimum nozzle diameter for 3D printing

Horizontal axis wind turbine performance analysis

The present work uses the method of Blade Element Momentum Theory as suggested by Hansen. The method applied to three blade models adopted from Rahgozar S. with the airfoil data used the data provided by Wood D. The wind turbine performance described in term of the thrust coefficient CT, torque coefficient CQ and the power coefficient Cp . These three coefficient can be deduced from the Momentum theory or from the Blade element Theory(BET). The present work found the performance coefficient derived from the Momentum theory tent to over estimate. It is suggested to used the BET formulation in presenting these three coefficients. In overall the Blade Element Momentum Theory follows the step by step as described by Hansen work well for these three blade models. However a little adjustment on the blade data is needed. To the case of two bladed horizontal axis wind turbine, Hansen’s approach works well over if the blade radius is RB the calculation should start from r = 0.1RB

Squirrel cage induction motor scalar control constant V/F analysis

In constant V/f control technique it is assume that the stator resistance and leakage inductance drops are negligible, especially at high speed and small load. In other words, the back emf is comparatively large at high speed and hence these voltage drops can be neglected. By maintaining constant V/f, constant Eg/f and hence constant air-gap flux is assumed. This assumption is however invalid at low speeds since a significant voltage drop appears across the stator impedance. The terminal voltage, V no longer approximates ag. By using MATLAB Simulink, the open-loop constant V/f is simulated. It is shown that the performance of the drive deteriorates at low speeds. The improvement in the performance by applying voltage boost is shown and discussed

A cytotoxicity and sub-acute toxicity study on tea leaves cultivated in Sabah

The present work investigated the cytotoxicity capacity of the MDA-MB-231 (human cancer-derived), A549 (human lung cancer-derived), Caov3 (human ovarian cancer-derived), and HeLa (human cervical cancer-derived) cell lines on a wide range of tea leaves; green tea, black tea, tea waste, and compost from Sabah. A group of male and female Sprague Dawley rats was used to screen the sub-acute toxicity of green tea extract in tea leaves from Sabah for 28 d. Results revealed that the ethanol extract of tea leaves had strong cytotoxic activity against all cancer lines. Tea waste showed higher cytotoxicity when extracted using hot water. The ethanol extract of black tea leaves exhibited the highest inhibitory activity against the proliferation of Caov3, whereas the ethanol extract of green tea leaves exhibited a promising cytotoxic activity against MDA-MB-231 and HeLa cell lines. Toxicity studies showed decreased testes weight and increased liver weight in male rats that were administered with 5000 mg/kg of tea extract. This coincided with the significant increase portrayed by enzyme alanine aminotransferase (ALT) in the serum of treated male rats in the 5000 mg/kg dose group. Moreover, there was an increase of alkaline phosphatase (ALP) and ALT for the female rats in the 5000 mg/kg dose group. The increased levels of ALT and ALP enzymes, as well as liver weight, signified mechanical trauma in the liver of male and female rats in the 5000 mg/kg dose group