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Development of sensor-based machinery vibration assessment system for effective faults diagnostic in condition based maintenance using machine learning / Syed Mohd Syafiq Syed Mahmud
No full textRotating machines such as turbines, motors, pumps, and fans generally generate the
vibration when operate under normal condition. However, the presence of excessive force
within the component of rotating machine can produce the high level of vibration.
Without a systematic monitoring system, a high vibration can accelerate the machine
wear, consume excess power, and damage the equipment. Consequently, the machine
requires to shut down for maintenance and resulting unplanned downtime and increase
the cost of maintenance. Furthermore, high level of vibration also can affect the machine
performance and even worse affect the safety problems in engineered systems. High
vibration caused by imbalance and misalignment become a major issue and leading to
component damage such as shaft, seals, coupling and bearings in various rotating
engineering application. Misalignments occurred when rotational centerlines are not
collinear while imbalance is occurred when shaft geometric and mass centerline are not
coincided. In a traditional way, the vibration data are present in plot such as orbit, time
waveform, spectrum etc. However, to analysis and diagnose the vibration fault required
a skilled worker who has vast experience, high technical knowledge, and expertise in
vibration analysis. Furthermore, to diagnose the vibration fault would consume more time
before final maintenance decision can be made. Therefore, the advance monitoring
system that can diagnose the machinery fault is developed to supervise machine condition
effectively. The system is build based on sophisticated deep learning program language
by using modern python program to provide an assist and support in supervised the trend,
performance of the machine and provide recommend decision. By using Convolutional
Neural Network (CNN) method in deep learning offer a higher accuracy in prediction and
detecting the vibration faults. The system is develop using 1D Convolutional Neural
Network that can provide very simple in structure, easy to understand and flexible in
design. Based on the validation result, the system successfully to achieve 100% accuracy in predict and detection each vibration faults correctly. In addition to this, the system is
assessed with difference type of input data and the system achieve low accuracy when
reducing the training data and using unprocessed data. However, this method required a
huge number of training and validation dataset in order to get a better accuracy in predict
and detecting the vibration faults. The fewer dataset could provide a result in a poor
approximation and subsequently produce an incorrect interpretation of vibration faults
A study on correlation between workload and stress level among secondary school teachers / Oumsree Ananthakumarl
No full textWorkload is the amount of work performed by someone usually within a specific time.
In occupational safety and health settings, dealing with workload can be stressful and
serve as a stressor for employees. Stress is felt as a pressure or burden often caused due
to increase in workload, role conflict and not enough support from co-workers. Teaching
career is a Nobel work but yet demanding career. Because of extended hours and heavy
workloads, teachers are in danger of being overworked and not taking serious care about
their own mental and physical health. The aimed of this research is to determine the
correlation between workload and stress level among secondary school teachers. It is a
cross-sectional study which use stratified sampling method to choose the schools.
Workload is calculated using HSE Management Standards Indicator Tools questionnaire.
Stress level calculated using International Stress Management Association United
Kingdom (ISMAUK) questionnaire. Research result shows that, 55.0% of the teachers are
having workload demand on sometimes and the stress level among school teachers are in
medium level which is 50.0%. Moreover, the Pearson coefficient value shows 0.005,
therefore there is significant correlation between workload and stress level among
secondary school teachers. This reveals that the teaching profession is no more the
profession of a little stress
Evaluation of safety health and environment at selected area: Construction site / Ahmad Azwan Anuar
No full textDue to the complexity and unpredictability of the operations, the construction industry has
a high prevalence of serious and fatal occupational injuries. Efforts to reduce workplace accidents
through various safety improvement methods have reached a roadblock after decades of effort.
Department of Occupational Safety and Health (DOSH) reports that the construction industry's
safety has improved, but a closer examination indicates that it still lags below most other industries.
Statistics also shows a decrease in the number of the recorded cases since 2019 but it was only
because most construction projects were put on hold due to COVID-19. Accidents in construction
site impacts the project performance, including delays in project completion, increases in project
costs, decreased productivity, and poor perceptions of the company. Accidents result from a
combination of contributing causes and in order to improve the overall safety performance, it is
necessary to investigate the root causes. This study examined reported accident cases kept by
DOSH and carried out questionnaires survey to the construction team to collect data. The finding
of this study identified the category of the factors; unsafe method, human element, unsafe
equipment, job site conditions, management and unique nature of the industry. The results
concluded that the main cause of construction accidents are worker’s attitude, negligence, poor
site management, failure to use PPE and working at high level
Computational fluid dynamics (CFD) analysis of human upper airway in sleep apnea patients under various breathing conditions / Wan Mohd Faizal Wan Abd Rahim
No full textObstructive Sleep Apnea (OSA) is a sleeping disorder that has troubled a sizeable population. There is an active area of research on OSA that intends to understand the airflow mechanism better and treat patients more effectively. These help medical practitioners or surgeons in the decision-making process of treating diseased airways. Moreover, the flow mechanisms and patterns of the airflow in the airway can be visualised in a Three-Dimensional (3D) space. Research is needed to enhance the diagnosis technique and future upper airway surgical therapy quality. ENT doctors can utilise the data analysed on the specific flow mechanism of the upper airways to detect probable obstruction locations and lead them to the anatomical blockage site for surgical treatments. Computational fluid dynamic (CFD) analysis was used as a solution tool to evaluate the overall breathing conditions, including inhalation, exhalation, light
breathing (during resting), and heavy breathing (during running). A medical imaging technique extracted the 3D model from the Computed Tomography (CT) scan images. Mesh generation and simulation were carried out via CFD software to evaluate the flow mechanism related to OSA patients. A Steady-state Reynold Averaged Navier-Stoke (RANS) with the k-ro Shear Stress Transport (SST) turbulence model was utilised. The airflow characteristics were quantified using pressure distribution, skin friction coefficient, velocity profile, Reynolds number, Turbulent Reynolds Number, and Turbulent Kinetic Energy (TKE). Contour plots at different planes were used to visualise the airflow distribution as it passed through different cross-sectional areas of the airway. The results-revealed-that-a smaller cross-sectional area of the airway caused, an increase in airflow parameters. Because of this discovery, the TKE can show the severity and location of the obstruction during breathing and the flow mechanism concentration. It is anticipated that this study will produce significant results by visualising the concentration in TKE or airflow mechanisms and characteristics of a patient's airway during comprehensive breathing. The findings of this study suggest that TKE may assist the practitioner in improving the diagnosis technique and the quality of future upper airway surgical therapy. Finally, CT scan data was used to create a 3D model of the patient's airway using the Mimic software. The simulation was carried out using the ANSYS FLUENT simulation software package. The current findings are beneficial to medical practitioners who work in the research field. The researchers hope to provide a clear representation of the characteristics of airflow
Pelaksanaan fiqh ayat kurikulum bersepadu tahfiz : Analisis penguasaan pelajar dan keberkesanannya terhadap hafazan al-Quran di Mittis Sabak Bernam / Syukr Abdul Hay Kamat
No full textKurikulum Bersepadu Tahfiz melalui KPM telah menyediakan platform pengajian tahfiz dan akademik secara integrasi. Melalui Hifz Al-Qur’ān KBT pelajar berpeluang mempelajari hafazan, dan kefahaman makna al-Qur’ān disamping mata pelajaran akademik yang lain. Pembelajaran Fiqh Ayat didapati kurang diberikan perhatian berbanding hafazan dalam pendidikan Tahfiz. Kajian ini bertujuan untuk mengkaji keberkesanan Fiqh Ayat terhadap hafazan pelajar tahfiz di MITTIS Sabak Bernam. Justeru penggunaan kaedah mix method dapat memenuhi keperluan kajian ini. Hasil dapatan soal selidik dianalisis menggunakan aplikasi Statistical Package for the Social Sciences (SPSS) sementara kajian kualitatif menggunakan analisis tematik. Dapatan analisis kesuluruhan soal selidik terhadap 103 responden mendapati nilai min 3.40 dengan interpretasi sederhana menunjukkan tahap pembelajaran, penguasaan dan keberkesanan Fiqh Ayat di MITTIS perlu diberikan perhatian sewajarnya. Dapatan kajian menunjukkan bahawa penguasaan Fiqh Ayat pelajar dapat ditambahbaik melalui faktor pengajaran guru dan pembelajaran pelajar. Hasil dapatan kajian turut mengesahkan bahawa Fiqh Ayat dapat memberi kesan terhadap penguasaan kefahaman ayat dan hafazan pelajar MITTIS. Diharapkan kajian ini dapat dimanfaatkan oleh institusi tahfiz bagi merealisasikan kemenjadian pelajar tahfiz KBT
Performance characteristics of crumb rubber modified asphalt mixed with reclaimed asphalt pavement and waste engine oil / Md Zahid Hossain Khan
No full textThis study aimed to characterize the reclaimed asphalt pavement (RAP) mixes for the preparation of asphaltic concrete wearing course with 14 mm nominal maximum aggregate size (ACW14) mix. The RAP was incorporated with two waste materials comprising a 6% crumb rubber (CR) (by weight of virgin binder) as a binder modifier to enhance the rheological properties of the asphalt binder and 15% of waste engine oil (WEO) (by weight of aged binder) as a rejuvenator to restore the properties of the aged binder. A total of five different asphalt mixes were prepared where a replacement of 0%, 30%, 50%, 70%, and 100% RAP aggregates are incorporated in the mix (R0, R30, R50, R70, and R100). The Marshall method was used to determine the optimum binder content (OBC). Finally, the mechanical performances, resilient modulus (MR), indirect tensile fatigue, moisture susceptibility, and mass loss (ML) tests of the five ACW14 mixes were conducted and analysed. Based on the results, it was found that 15% WEO (by weight of aged binder) was able to soften the extracted aged binder. In addition, the OBC gradually decreased with the addition of RAP content. The R0 recorded the highest OBC value (5.9%), while the OBC values of R30, R50, R70, and R100 mixes were 5.8, 5.7, 5.5, and 5.5%, respectively. Furthermore, the results showed that the Marshall parameters, moisture susceptibility, and ML values of the RAP mixes
complied with the criteria outlined by the Public Works Department Malaysia. According to the MR performance, the MR increased with the increment in RAP content, and R100 obtained the highest value. The moisture susceptibility test revealed that all RAP mixes were more resistant to moisture damage as the tensile strength ratio (TSR) values were higher than the standard value. In terms of fatigue resistance, the R30, R50, and R70 mixes showed better performance than the R0, while the R100 mix showed approximately 5% less resistance to fatigue than the R0. The ML test indicated that all RAP mixes exhibited highly ravelling resistance. Statistically, the amount of RAP and binder used significantly affected the ACW14 mix’s design performance
Synthesis, characterization and application of menthol-based low transition temperature mixtures for the vortex- assisted dispersive liquid-liquid microextraction of pyrethroids from water samples / Siti Amira Mat Hussin
No full textIn this study, three newly menthol-based natural low transition temperature mixtures (LTTMs) were successfully synthesized. DL-menthol as hydrogen bond acceptor (HBA) meanwhile thymol, sesamol and 3-hydroxybenzoic acid were selected as hydrogen bond donor (HBD). The characterization of LTTMs was monitored and studied by polarizing optical microscopy (POM), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and Nuclear Magnetic Resonance (NMR). In addition, density, viscosity and water content of LTTMs were determined to analyse their solvent characteristics. Thermogravimetric analysis (TGA) was studied to identify the thermal stability. These LTTMs have been applied as green extraction solvents in vortex-assisted dispersive liquid-liquid microextraction (VA-DLLME) for the extraction of pyrethroid pesticides determined by high-performance liquid chromatography with a diode-array detector (HPLC-DAD). Several key parameters that affect pyrethroid extraction efficiency were identified and optimized. After optimization, the LTTM-VA-DLLME method was found to be able to detect pyrethroids in the range of 0.5 - 1000.0 μg L-1 with good linearity (R2 = 0.9988-0.9995). The relative standard deviation of inter-day and intra-day precisions were 2.2 - 5.0 % (n = 5) and 1.2 - 1.9% (n = 7) respectively. The limit of detection (LODs) and limit of quantification (LOQs) were in the range of 0.05 - 0.10 μg L-1 and 0.18 - 0.35 μg L-1, respectively. The optimized method can successfully determine pyrethroids in water samples with good recoveries of 73–111%
Performance evaluation of the BioSculptor® system as a CAD/CAM tool for transtibial residual limb shape monitoring and generation of socket interface roughness / Nur Afiqah Hamzah
No full textMultiple factors cause residual limb volume fluctuation, such as amputee's age, health
level, and activity level. With the introduction of Computer-aided design and Computeraided
manufacturing (CAD/CAM) in the 1980s, the technology has globally changed the
fabrication and delivery of prosthetics and orthotics products to amputees. One of the
functions of CAD/CAM required is to capture the variation in size and shape of the
residual limbs. This thesis was designed to study one of the commercial CAD/CAM
systems, the BioSculptor® CAD/CAM system, in capturing transtibial residual limb
circumference profiles because there is a limited study done on real subjects for this
particular system. Three objectives identified to assess the efficacy and accuracy of the
system's components (Bioscanner, Bioshape, and Biomill) and compared the data with
the circumferential profiles obtained with the conventional standard tape measurement
method. To determine and evaluate the accuracy and the efficacy of the system, active
and non-active amputees were recruited to conduct a walking activity for 5 to 25 minutes
of walking intervals. Findings showed, both manual and BioSculptor® ‘s Bioscanner
measurements gave a general comparable linear pattern. Smallest differences can be seen
especially the circumference measurements near the mid-patella tendons. Likewise,
pressure- areas of the limb showed only an average of 2.28% differences in measurement
between the two techniques. The initial study conducted showed high reliability and
repeatability of intra-class correlation (ICC) >0.9. The mean circumferences between the
two methods revealed that Bioscanner gave a higher estimation for both amputees.
Bioscanner also identified the non-consistence volume change at different locations of the circumference profiles. Both amputees had a significant volume increase at the distal
end of the limbs (7.35% change in non-active and 8.83% in active amputees). The
residual limb volume's percentage differences were consistent with 2.4% to 9.3%.
Additionally, Pearson's coefficient correlation resulted in a high correlation between the
digital and manual, ranging from 0.973 to 1 with P<0.05. The advancement of the
CAD/CAM system allows users to select the level of surface roughness of the milling
products. Surprisingly, there is a lack of study on different surface roughness from
milling processes at liner-residual limb interface. Assessment of the effect of different
surface roughness from milling processes allowed personalized socket-limb interface
based on the amputee's level of activity. To examine the possible effect of different
surface roughness on limb shape management, this feature on Biomill was studied. Three
surface parameters (arithmetic average (Ra), root mean square roughness (Rq), and tenpoint
height (Rz) were chosen, and the results of different surface roughness
(STANDARD, FINE, COARSE, and FAST) compared with a liner that had been
fabricated conventionally. The Ra values of the conventional liner, 8.43 μm, were
determined to be in-between the Ra values of STANDARD and FAST surfaces, which
were 8.33 μm and 8.58 μm, respectively. Cutting conditions, such as the feed rate,
maximum depth of cut, and speed rate, directly affected the roughness of the surface. By
acknowledging the potential of BioSculptor ®, the results of this study would provide
guidelines for prosthetists in managing residual limb volume change
Influence of plant growth regulators on content of Azadirachtin and proteome profile in neem callus under jasmonic acid and salt stress conditions / Sharmilla Ashokhan
No full textFor centuries, neem (Azadirachta indica L.) has been utilized as a primary source of medicine due to its antimicrobial, larvacidal, antimalarial, and antifungal properties. Its potential as an effective biopesticide has recently garnered attention, especially towards efficient and continuous production of its bioactive compounds. The present study investigated the effect of the plant growth regulators (PGRs) thiadiazuron (TDZ) and 2, 4-dichlorophenoxyacetic acid (2, 4-D) on the induction of callus and subsequent comparative proteomic analyses upon abiotic stress (salt and jasmonic acid (JA)) induction. The callus cultures were initiated from leaf and petiole explants and cultured on Murashige and Skoog (MS) medium supplemented with TDZ (0.2–0.6 mg/L) and 2,4-D (0.2–0.6 mg/L), either applied individually or in combination. Callus was successfully induced from both explant types at different rates, where media with 0.6 mg/L of TDZ resulted in the highest fresh weight (3.38 ± 0.08 g). A culture duration of six weeks resulted in the production of green, brown and cream-coloured callus. The green callus contained the highest amount of anthocyanin, chlorophyll and carotenoid and total phenolic content compared to brown and cream callus. Green callus also exhibited the highest antioxidant potential plus the highest accumulation of azadirachtin (AZA) at 214.53 ± 33.63 mg/G dry weight (DW). However, small amounts of AZA was detected in brown and cream callus. Green callus also profoundly exhibited active cytotoxic activity against SKOV-3 cells. In a further abiotic stress induction and comparative proteomics experiment, green callus was subjected to 0.5 % (w/v) of NaCl and 5 mg/L of JA, which was identified as the optimum concentration for stress treatment. Four protocols derived from either TCA/acetone and/or phenol procedures were evaluated to determine the optimum protein extraction method for neem callus. The TCA-acetone method with inclusion of PVPP recovered highest amount proteins, with superior gel resolution and minimal streaking. The 2-DE technique applied to discover stress-response proteins revealed that proteins associated with oxidoreduction, energy, transcriptional, stress response, respiration and cell division were differentially regulated under salinity stress treatment. Meanwhile, the expression of proteins classified in the group of energy, photosynthesis, protein synthesis, oxidoreduction, and post-transcriptional regulation was altered in the JA-stressed callus. Combining with these outcomes, the accumulation of AZA was noticeably reduced in salt and JA-treated callus, suggesting these tested stress parameters were not effective in improving AZA production in the neem callus. Overall, the present analysis provides valuable information on applying plant tissue culture as an alternative for sustainable production of major bioactive constituents in A. indica. Together, the proteomic results brought forward a possible fundamental representation of the mechanism associated with the salt and JA tolerance in the neem callus
Extraction of proteins from natural rubber latex wastewater for metal removal and its antimicrobial properties / Hairani Tahir
No full textNatural rubber latex plant waste from a centrifuge process contains hev protein. However, these proteins are mostly allergenic. The precipitation process carried out to purified protein from the waste bulk at different pH conditions, namely, from pH 3 to pH 8. The purpose of varying pH condition was to capture specific proteins. Amount of protein collected at different pH measured and it found that greater amounts collected at pH 4 and pH 7. Precipitation also carried out without the use of ammonium sulphate compare the amount of protein collected. Overall, the amount of protein collected from the salt-free condition was lesser by 25 %. The purified protein was then isolated using polyarcryl amide gel Biorad P-60 gel via open column chromatography. Each isolate containing protein introduced to SDS PAGE electrophoresis using benchmark protein marker as a standard to identify the isolated protein. Amongst the proteins isolated, seven types found to match the molecular weight of 20 kDa hevea protein to 40 kDa. Isolated protein was characterized using FTIR to countercheck the existence of protein for the particular isolate and using UV at 280 nm and 595 nm to estimate the concentration of protein in each number of isolates. Each isolate containing protein freeze-dried for storage purposes. Powder samples were more convenient to carry about and occupied smaller space compared to liquid samples, which were more susceptible to degradation or putrefaction, especially at warmer temperatures. The identified proteins were cross-matched with the hevea protein databank proposed earlier and used according to its specific function. At first, Hevein, hev b6, one of the isolated proteins, intended for antifungal study and mangan superoxide dismutase, Hev b10 for metal extraction study, but the limited amount of proteins collected meant that the overall study of precipitated protein undertaken, instead. Freeze-dried precipitated proteins analyzed for traces of metal and it was found that by using AAS, about 2 ppm of copper and 4 ppm of lead were recorded. However, many samples was saved by using ICP and additionally, 254 ppm zinc, 0.013 ppm aluminum, 0.129 ppm of selenium, 0.001 ppm nickel, 0.749 of ferum and 19.7 ppm of magnesium were detected. Proteins collected from different purification techniques exposed to 2 ppm, 5 ppm, 10 ppm, and 20 ppm sets of metal ion concentration to study their binding capability. Results showed that as the concentration of protein was increased, the metal removal intensity was also increased. It also observed that the binding capability differed between metals