2,329 research outputs found

    Comparison Study On Pinch-Hitting Vibration Signal Analysis for Automotive Bearing: I-KazTM and I-Kaz 3D

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    Rotating machines are now an essential part of the automotive industry. Meanwhile, a bearing is playing the most important component of rotating machinery. To sustain the system's smooth running, maintenance methods such as preventive maintenance, breakdown maintenance, and predictive maintenance are used. Under preventive maintenance, vibration analysis is used to diagnose machines bearing faults. The main objective is to recognize bearing defects in a mechanical device by acquiring signals from the bearing using data acquisition hardware. This analysis is conducted under various load torque conditions, speeds, and defect types. A modular hardware configuration consisting of an accelerometer acquires the vibration signal. The signals are analyzed by using I-kazTM and I-kaz 3D signal analysis and its main objective is to observe the degree of dispersion data from its mean point.  This analysis resolves the issues associated with time domain analysis. This pinch-hitting analysis research was conducted in two stages.  The first stage is an experimental process that uses 3 types of bearings, the healthy (BL), inner race fault (IRF), and defect at outer race (ORF) bearing on the Machine Fault Simulator and forces with a different type of speed (1000, 1500 and 2500 rpm) and load variation (0.0564, 0.564 and 1.1298 N-m). In the second stage, computing the coefficient value and plots of signal’s I-kazTM and I-kaz 3D based on the bearings type were done accordingly. As a result, the analysis for detecting inner race fault, the deviation percentage averages calculation obtained the I-kazTM coefficient shows a better result with 96.86% by comparing to the I-kaz 3D that achieves 94.20%. Similarly, for the outer race defect, I-kazTM lead with 65.40% compared to I-kaz 3D with only 54.82%.  &nbsp

    Comparison Study On Pinch-Hitting Vibration Signal Analysis for Automotive Bearing: I-KazTM and I-Kaz 3D

    Get PDF
    Rotating machines are now an essential part of the automotive industry. Meanwhile, a bearing is playing the most important component of rotating machinery. To sustain the system's smooth running, maintenance methods such as preventive maintenance, breakdown maintenance, and predictive maintenance are used. Under preventive maintenance, vibration analysis is used to diagnose machines bearing faults. The main objective is to recognize bearing defects in a mechanical device by acquiring signals from the bearing using data acquisition hardware. This analysis is conducted under various load torque conditions, speeds, and defect types. A modular hardware configuration consisting of an accelerometer acquires the vibration signal. The signals are analyzed by using I-kazTM and I-kaz 3D signal analysis and its main objective is to observe the degree of dispersion data from its mean point.  This analysis resolves the issues associated with time domain analysis. This pinch-hitting analysis research was conducted in two stages.  The first stage is an experimental process that uses 3 types of bearings, the healthy (BL), inner race fault (IRF), and defect at outer race (ORF) bearing on the Machine Fault Simulator and forces with a different type of speed (1000, 1500 and 2500 rpm) and load variation (0.0564, 0.564 and 1.1298 N-m). In the second stage, computing the coefficient value and plots of signal’s I-kazTM and I-kaz 3D based on the bearings type were done accordingly. As a result, the analysis for detecting inner race fault, the deviation percentage averages calculation obtained the I-kazTM coefficient shows a better result with 96.86% by comparing to the I-kaz 3D that achieves 94.20%. Similarly, for the outer race defect, I-kazTM lead with 65.40% compared to I-kaz 3D with only 54.82%.  &nbsp

    Virtual Machine based Autonomous Web Server

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    Enterprises are turning to Internet technology to circulate information, interact with potential customers and establish an e-commerce business presence. These activities are depending highly on Web server and maintaining good server security has been a requirement for avoiding any malicious attacks especially web defacements and malware. Web server administrators should be alert and attentive to the status of the server at all time. They need to be persistent in monitoring the server in order to detect any attempted attacks. This is an advantage for a web server that is maintained by a big company that has a big budget to hire a knowledgeable web server administrator, for a new established small company it will only burden their expenses. To overcome this problem, this paper proposes a low cost system called Autonomous Web Server Administrator (AWSA) that is fully developed using open source software. AWSA combines several computing concepts such as Virtual Machine, Intrusion Detection System and Checksum. AWSA offers a Virtual Machine based Web server that has the ability to automatically detect intrusions and reconstruct corrupted data or the file system without any human intervention

    Visual performance and motorcycle safety-related impacts of various high beam headlight intensities

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    In Malaysia, the three main types of motorcycle accidents include collision with passenger cars, collision with other motorcycles and single-motorcycle accidents. An accident may occur due to the lack of road design consistency and visibility where most drivers make more errors in the absence of geometric features. One of the most important barriers to the more frequent use of high beam headlight is the length of visibility of the headlight beam in relation to the stopping distance of a vehicle. Furthermore, it is crucial to evaluate the current limits on the luminous intensity of high beam headlights that is considered visible for a driver to come to a stop. Therefore, this first stage study summarizes and investigates the stopping sight distances, braking distances that allow for the evaluation of the vehicle's performance to increase the capability of both the driver and vehicle with regard to safety. A total of ten experiments were carried out with a passenger car, the Perodua Myvi, on a road within a local university. The results found that Stopping Sight Distance (SSD) could be used to determine the SSD graph by considering the velocity (v0), driver’s perception reaction time (tR), coefficient of breaking friction (fT), gravitational constant (g), deceleration rate (a) and roadway grade (G). The study also concludes that SSD could be used to determine the SSD graph by considering the velocity (v0), driver’s perception reaction time (tR), coefficient of breaking friction (fT), gravitational constant (g), deceleration rate (a) and roadway grade (G). Ultimately, the study also indicates that the time to switch to hi-beam (Automatic High Beam – AHB) is at SSD distance (meter or second)

    Gender specific decrease of a set of circulating Nacylphosphatidyl ethanolamines (NAPEs) in the plasma of Parkinson’s disease patients

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    Introduction: Current markers of Parkinson's disease (PD) fail to detect the early progression of disease state. Conversely, current omics techniques allow the investigation of hundreds of molecules potentially altered by disease conditions. Based on evidence previously collected by our group in a mouse model of PD, we speculated that a particular set of circulating lipids might be significantly altered by the pathology. Objectives: The aim of current study was to evaluate the potential of a particular set of N-acyl-phosphatidylethanolamines (NAPEs) as potential non-invasive plasma markers of ongoing neurodegeneration from Parkinson's disease in human subjects. Methods: A panel of seven NAPEs were quantified by LC-MS/MS in the plasma of 587 individuals (healthy controls, n = 319; Parkinson's disease, n = 268); Random Forest classification and statistical modeling was applied to compare Parkinson's disease versus controls. All p-values obtained in different tests were corrected for multiplicity by controlling the false discovery rate (FDR). Results: The results indicate that this panel of NAPEs is able to distinguish female PD patients from the corresponding healthy controls. Further to this, the observed downregulation of these NAPEs is in line with the results in plasma of a mouse model of Parkinson's (6-OHDA). Conclusions: In the current study we have shown the downregulation of NAPEs in plasma of PD patients and we thus speculate that these lipids might serve as candidate biomarkers for PD. We also suggest a molecular mechanism, explaining our findings, which involves gut microbiota

    Community acquired and post-transfusion hepatitis C is there a difference?

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    We analyzed 77 consecutive hepatitis C antibody positive patients to compare the history, laboratory data and histological features of community acquired (CA) and post-transfusion (PT) hepatitis C. Forty-six patients had CA and 31 PT hepatitis C. Mean age in both groups was same (45.67 vs 46 years). Male to female ratio was 2:1 in the CA group and 1:2.4 in the PT group. Mean duration between jaundice and first presentation was 8.9 years in the CA group and the mean duration between transfusion and first presentation was 9.8 years in PT group. No significant difference was found between two groups in the laboratory data. Liver biopsy was done in 32 patients (19 CA and 13 PT group). Mean histological score for disease activity was 9.3 in both groups, although more (68%) patients in the CA group had cirrhosis with chronic active hepatitis, (CAH) as compared to the PT (54%) group. Hepatitis C is an important cause of CA hepatitis. PT hepatitis C is more common in females because of increased likelihood of receiving transfusion for obstetric and gynaecological reasons. There is no significant difference in the laboratory and histological features between CA and PT hepatitis C

    Preparation and Characterization of pH- and Temperature-responsive by Different Composition Chitosan-P(MAA-co-NIPAM) Hydrogel for Drug Delivery System / S. Z. M. Rasib ...[et al.]

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    In this paper, (chitosan-poly(methacrylic acid-co-N-isopropylacrylamide)) [Chitosan-P(MAA-co-NIPAM)], a multi-responsive hydrogel was successfully fabricated by free-radical polymerization in aqueous media. Chitosan was crosslinked with P(MAA-co-NIPAM) network as a suggestion to improve the efficiency of chitosan as a drug carrier. Due to the hydrophilic and hydrophobic characteristics of MAA and NIPAM monomers presented in the network, the swelling behaviour at different pH and temperature was investigated in this paper. The composition, morphological stability, swelling behavior at various pH and temperature environment of the Chitosan-P(MAA-co-NIPAM) hydrogel were studied using Fourier transform infra-red (FT-IR), Field Emission Scanning Electron Microscopy (FESEM) and swelling test by weight ratio of the hydrogel. This study found that additional feed of MAA and NIPAM monomers during polymerization increased the amount of PMAA and PNIPAM crosslinked in the hydrogel. As a result, the value of LCST increased from 32℃ to more than 37℃. The swelling ratio of the hydrogel was found to be maximum at pH 7 which is suitable to be used in body system especially in human blood of pH 7.4. Thus, the role of Chitosan-P(MAA-co-NIPAM) as a carrier of a drug in drug delivery system has been approved

    Dipotassium disulfanilamidate trihydrate

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    Ergogenic, anti-diabetic and antioxidant attributes of selected Malaysian herbs: characterisation of flavonoids and correlation of functional activities

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    In the present work, aqueous ethanolic (60% ethanol) extracts from selected Malaysian herbs including Murraya koenigii L. Spreng, Lawsonia inermis L., Cosmos caudatus Kunth, Piper betle L., and P. sarmentosum Roxb. were evaluated for their ergogenic, anti-diabetic and antioxidant potentials. Results showed that the analysed herbs had ergogenic property and were able to activate 5'AMP-activated protein kinase (AMPK) in a concentration dependant manner. The highest AMPK activation was exhibited by M. koenigii extract which showed no significant (p > 0.05) difference with green tea (positive control). For anti-diabetic potential, the highest α-glucosidase inhibition was exhibited by M. koenigii extract with IC50 of 43.35 ± 7.5 μg/mL, which was higher than acarbose (positive control). The determinations of free radical scavenging activity and total phenolics content (TPC) indicated that the analysed herbs had good antioxidant activity. However, C. caudatus extract showed superior antioxidant activity with IC50 against free radical and TPC of 21.12 ± 3.20 μg/mL and 221.61 ± 7.49 mg GAE/g, respectively. RP-HPLC analysis established the presence of flavonoids in the herbs wherein L. inermis contained the highest flavonoid (catechin, epicatechin, naringin and rutin) content (668.87 mg/kg of extract). Correlations between the analyses were conducted, and revealed incoherent trends. Overall, M. koenigii was noted to be the most potent herb for enhancement of AMPK activity and α-glucosidase inhibition but exhibited moderate antioxidant activity. These results revealed that the selected herbs could be potential sources of natural ergogenic and anti-diabetic/antioxidant agents due to their rich profile of phenolics. Further analysis in vivo should be carried out to further elucidate the mechanism of actions of these herbs as ergogenic aids and anti-diabetic/antioxidant agents

    Intertwining the arts and sciences to stimulate a creative mind

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    From the basic motion of a simple pendulum, which acts as a tool that turns a blank canvas into pure abstract art, this particular concept has been applied to science-related art to showcase its tremendous impact on scientific, psychological and educational fields. The Art and Science Program is a collaborative artistic program between the committees from the Chemical and Energy School of Engineering, UTM, and Sekolah Tun Fatimah (STF), with the aim of examining the impacts of the rotational motion of the pendulum which can generate mesmerizing art on blank mahjong papers. The outcome of the art has been influenced by various factors, such as the viscosity of the paint used, the flowrate of the paint drip, the velocity of the paint-pendulum-modelled dripper, the position of the release point, and the motion of the dripper arising from the resultant force of multiple interacting forces. By showing the interconnections between pendulum motion, gravitational force, potential and kinetic energies, and the fundamentals of fluid dynamics, artistic abstract paintings can be created from the science of mechanics. Intertwining the arts and sciences that has been the main focus of this program can garner greater appreciation, even embraced, as it results in a significant effect on the development of both creative and critical thinking among the participants and committees
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