Displaying publications 21 - 40 of 88 in total

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  1. Wicaksono FD, Arshad YB, Sihombing H
    Heliyon, 2020 Apr;6(4):e03607.
    PMID: 32346625 DOI: 10.1016/j.heliyon.2020.e03607
    This paper presents the novel approach of the Norm-dist Monte-Carlo fuzzy analytic hierarchy process (NMCFAHP) to incorporate probabilistic and epistemic uncertainty due to human's judgment vagueness in multi-criteria decision analysis. Normal distribution is applied as the most appropriate distribution model to approximate the probability distribution function of the criteria and alternatives within Monte-Carlo simulation. To test the applicability of the proposed NMCFAHP, the case study of non-destructive test (NDT) technology selection is performed in the Petroleum Company in Borneo, Indonesia. When compared with the conventional triangular fuzzy-AHP, the proposed NMCFAHP method reduces the standard error of mean values by 90.4-99.8% at the final evaluation scores. This means that the proposed NMCFAHP significantly involves fewer errors when dealing with fuzzy uncertainty and stochastic randomness. The proposed NMCFAHP delivers reliable performance to overcome probabilistic uncertainty and epistemic vagueness in the group decision making process.
  2. Al-Amshawee SKA, Yunus MYBM
    Environ Res, 2023 Feb 15;219:115115.
    PMID: 36574794 DOI: 10.1016/j.envres.2022.115115
    The incorporation of a spacer among membranes has a major influence on fluid dynamics and performance metrics. Spacers create feed channels and operate as turbulence promoters to increase mixing and reduce concentration/temperature polarization effects. However, spacer geometry remains unoptimized, and studies continue to investigate a wide range of commercial and custom-made spacer designs. The in-depth discussion of the present systematic review seeks to discover the influence of Reynolds number or solution flowrate on flow hydrodynamics throughout a spacer-filled channel. A fast-flowing solution sweeping one membrane's surface first, then the neighboring membrane's surface produces good mixing action, which does not happen commonly at laminar solution flowrates. A sufficient flowrate can suppress the polarization layer, which may normally require the utilization of a simple feed channel rather than complex spacer configurations. When a recirculation eddy occurs, it disrupts the continuous flow and effectively curves the linear fluid courses. The higher the flowrate, the better the membrane performance, the higher the critical flux (or recovery rate), and the lower the inherent limitations of spacer design, spacer shadow effect, poor channel hydrodynamics, and high concentration polarization. In fact, critical flow achieves an acceptable balance between improving flow dynamics and reducing the related trade-offs, such as pressure losses and the occurrence of concentration polarization throughout the cell. If the necessary technical flowrate is not used, the real concentration potential for transport is relatively limited at low velocities than would be predicted based on bulk concentrations. Electrodialysis stack therefore may suffer from the dissociation of water molecules. Next studies should consider that applying a higher flowrate results in greater process efficiency, increased mass transfer potential at the membrane interface, and reduced stack thermal and electrical resistance, where pressure drop should always be indicated as a consequence of the spacer and circumstances used, rather than a problem.
  3. Al-Amshawee SKA, Yunus MYBM
    PMID: 37620701 DOI: 10.1007/s11356-023-28727-y
    Electrodialysis desalination uses ion exchange membranes, membrane spacers, and conductors to remove salt from water. Membrane spacers, made of polymeric strands, reduce concentration polarization. These spacers have properties such as porosity and filament shape that affect their performance. One important property is the spacer-bulk attack angle. This study systematically reviews the characteristics of a 45° attack angle of spacers and its effects on concentration polarization and fluid dynamics. Membrane spacers in a channel create distinct flow fields and concentration profiles. When set at a 45° attack angle, spacers provide greater turbulence and mass-heat transfer than traditional spacers. This is because both the transverse and longitudinal filaments become diagonal in relation to the bulk flow direction. A lower attack angle (<45°) results in a lower pressure drop coupled with a decline in wakes and stream disruption because when the filaments are more parallel to the primary fluid direction, the poorer their affect. This research concludes that membrane spacers with a 45° spacer-bulk attack angle function optimally compared to other angles.
  4. Win TT, Yusuf Y, Jaafar H
    Malays J Med Sci, 2013 Mar;20(2):10-6.
    PMID: 23983572 MyJurnal
    Many studies on the role of apoptosis in cancer development and management have been undertaken. Apoptotic activity depends partly on the balance between anti-apoptotic (Bcl-2) and pro-apoptotic (Bax) activities. This study compared Bcl-2 and Bax expression in the tumour cells and endothelial cells of tumour blood vessels in soft tissue sarcoma, and examined the association of these with tumour characteristics.
  5. Nurul Nazierah Mohd Yusri, Kartini Kamaruddin, Hamidah Mohd Saman, Nuraini Tutur
    Scientific Research Journal, 2018;15(1):47-58.
    MyJurnal
    Sewage sludge is a by-product generated within the wastewater treatment process. Severe concern arised as the sludge are massively been dumped to the landfill and it may affect the environment. Many studies had been conducted in reusing the sewage sludge as construction material, where it is one of the optional ways to solve the issue. In this study, dried sewage sludge was incinerated with two different temperatures in order to produce sewage sludge ash (SSA), which are 800°C and 1000°C. Afterfew processes, this SSA then reused in mortar as cementreplacement with the replacement percentage of 5%, 10%, 15% and 20% by weight. The strength performance of mortar specimens was investigated after 7, 28, 60 and 90 days of curing. From the results, it is clearly showed that the compressive strength of all mortar specimens increased when the period of curing was prolonged. Moreover, almost all compressive strength of SSA mortars was higher than the control mortar. Therefore, there is potential to reuse this waste material as part of construction materials and hence, its plays an important role for future researches in minimisation of waste.
  6. Mohd Hafiz Abu Hassan, Syaza Azhari, Muhammad Anas Yuzairi Mohd Yusri
    MyJurnal
    Gold nanoparticles (AuNPs) are a highly versatile compound to be used in sensing components due to their unique physicochemical and optical properties. Due to its flexibility for surface conjugation, glutathione disulfide-linked gold nanoparticle (AuNP-GSSG) was produced in this study to assess its sensing performance as a colorimetric sensor for human chorionic gonadotropin (HCG). Spectroscopic characterization of AuNP-GSSG confirmed the conjugation of GSSG onto the surfaceofAuNPs.AuNP-GSSGalsoshowedhighsensoryperformancewithgoodlinearityandlowdetectionlimit.However,due to the high percentage of interference, usage of AuNP-GSSG as an HCG sensor requires further pre-treatment step to reduce the interference and increase the sensoraccuracy.
  7. Ahmad Rasdan Ismail, Baba Md Deros, Mohd Yusri Mohd Yusof, Mohd Hanifiah Mohd Haniff, Isa Halim
    MyJurnal
    Environmental factors such as temperature, lighting and noise have very significant impact to workers’ health, safety, comfort, performance and productivity. In an ergonomically design industrial work environment, these factors need to be control at their optimum levels. The main objective of this study is to find the effect of temperature, illuminance and sound pressure level on workers’ productivity in automotive industry. To perform this study a workstation in an automotive component manufacturing was selected as the location of the study. Results of data analysis showed there were relationships between temperature, illuminance and noise on workers’ productivity. Later, the authors’ developed multiple linear equation models to represent the relationships between temperature, illuminance and noise on the workers’ productivity. These multiple linear equation models could be used to predict the production rate for the workstation by referring to the value of temperature, illuminance and noise level.
  8. Yusri, Othman A. Karim, Khairul Nizam Abdul Maulud, Mohd. Ekhwan Toriman
    Penggunaan tanah boleh mengakibatkan perubahan fungsi dari masa ke masa, sesuai dengan tujuan pembangunan. Kawasan Bandar Pekanbaru terdiri daripada 12 sub-kawasan persekutuan dengan jumlah keluasan kira-kira 632.26 km2. Tujuan kajian adalah untuk menganalisis perubahan guna tanah daripada aspek ruang dan masa. Data guna tanah yang diambil kira dalam analisis ini adalah peta guna tanah 1992 dan 2004. Hasil analisis dengan menggunakan perisian ArcView GIS versi 3.2 mendapati bahawa telah berlaku penurunan guna tanah signifikan, iaitu jenis perkebunan dan hutan tahun 2004. Peningkatan jenis lain-lain, penggunaan tanah seperti permukiman dan tumbuhan/semak tahun 2004 telah berlaku. Perubahan ini merupakan pengaruh daripada pembangunan bandar. Sebaliknya, pembangunan bandar boleh memberi impak negatif terhadap sekitaran jika pola perubahan guna tanah dirancang tanpa pengurusan yang baik.
  9. Azizan Ahmad, Siti Aminah Mohd Noor, Mohd Reduan Abu Bakar, Mohd. Yusri Abdul Rahman
    Ionic conductivity of composite polymer electrolyte PVC-Al2O3-LiClO4 as a function of Al2O3 concentration has been studied. The electrolyte samples were prepared by solution casting technique. Their ionic conductivity was measured using impedance spectroscopy technique. It was observed that the conductivity of the electrolyte varies with Al2O3 concentration. The highest room temperature conductivity of the electrolyte of 3.43 × 10-10 S.cm-1 was obtain at 25% by weight of Al2O3 and that without Al2O3 filler was found to be 2.43 × 10-11 S.cm-1. The glass transition temperature decreases with the increase of Al2O3 percentage due to the increasing amorphous state, meanwhile the degradation temperature increases with the increase of Al2O3 percentage. Both of these thermal properties influence the enhancement of the conductivity value. The morphology of the samples shows the even distribution of the Al2O3 filler in the samples. However, the filler starts to agglomerate in the sample when high percentage of Al2O3 is being used. In conclusion, the addition of Al2O3 filler improves the ionic conductivity of PVC-Al2O3-LiCIO4 solid polymer electrolyte.
  10. Nur Azrina Mohd Azman, Md Pauzi Abdullah, Mohammad Yusri Hassan, Dalila Mat Said, Faridah Hussin
    MyJurnal
    Malaysia has introduced a new Time of Use (ToU) tariff scheme known as Enhanced ToU (EToU) for
    commercial and industrial customers. EToU is a more detailed pricing scheme where one day time frame
    is divided into six period blocks as compared to only two period blocks in the existing ToU. Mid-peak
    tariff is introduced to the existing peak and off-peak tariff. Off-peak rate for EToU is significantly lower
    than the existing off-peak rate but the peak rate is much higher. EToU is designed to motivate users to
    reduce their consumption during peak hours or shift the load to mid-peak or off-peak hours, which if
    done correctly can reduce the electricity bill while maintaining electricity consumption. This new EToU
    scheme will benefit consumers if they are able to shift consumption from peak-hours into mid-peak
    or off-peak hours. This paper assesses the amount of load shifting that is required based on customers’
    load profile and EToU rates. The load profile data of an office building in Putrajaya, Malaysia is used
    as a case study.
  11. Naik VR, Wan Faiziah WA, Musa MY
    Indian J Pathol Microbiol, 2009 1 13;52(1):86-7.
    PMID: 19136792
    Choristoma is a benign tumor where new bone formation occurs. It occurs exclusively in the flat bones of the skull and face. These are slow growing lesions that are usually completely asymptomatic and only present when there is a disruption in the function of the organ due to its large size as it grows. These choristomas can rarely occur in soft tissues especially in the head, eye, tongue, or extremities. Choristomas of the soft tissues are very rare. Only 61 cases of choristomas of the tongue have been reported in literature. Here we report a case of choristoma in the base of the tongue in a 25-year-old Malay female.
  12. Lim ZF, Rajendran P, Musa MY, Lee CF
    Vis Comput Ind Biomed Art, 2021 May 20;4(1):14.
    PMID: 34014417 DOI: 10.1186/s42492-021-00080-2
    A numerical simulation of a patient's nasal airflow was developed via computational fluid dynamics. Accordingly, computerized tomography scans of a patient with septal deviation and allergic rhinitis were obtained. The three-dimensional (3D) nasal model was designed using InVesalius 3.0, which was then imported to (computer aided 3D interactive application) CATIA V5 for modification, and finally to analysis system (ANSYS) flow oriented logistics upgrade for enterprise networks (FLUENT) to obtain the numerical solution. The velocity contours of the cross-sectional area were analyzed on four main surfaces: the vestibule, nasal valve, middle turbinate, and nasopharynx. The pressure and velocity characteristics were assessed at both laminar and turbulent mass flow rates for both the standardized and the patient's model nasal cavity. The developed model of the patient is approximately half the size of the standardized model; hence, its velocity was approximately two times more than that of the standardized model.
  13. Buntat Y, Saud MS, Mokhtar M, Kamin Y, Feh LS
    Work, 2016 Oct 17;55(2):481-487.
    PMID: 27689600
    Increase in the occurrence of existing diseases, continual emergence of new or exotic diseases and re-emergence of old diseases have placed increasing demands on biomedical services in Malaysia. Biomedical technicians play an important role in operating biomedical instruments. However, there are no clear specifications about characteristics and traits for these semi-professional employees. Employers in a few studies claimed that biomedical graduates are not ready to enter and face challenges in the job market.
  14. Jayaraj VJ, Avoi R, Gopalakrishnan N, Raja DB, Umasa Y
    Acta Trop, 2019 Sep;197:105055.
    PMID: 31185224 DOI: 10.1016/j.actatropica.2019.105055
    Dengue is fast becoming the most urgent health issue in Malaysia, recording close to a 10-fold increase in cases over the last decade. With much uncertainty hovering over the recently introduced tetravalent vaccine and no effective antiviral drugs, vector control remains the most important strategy in combating dengue. This study analyses the relationship between weather predictors including its lagged terms, and dengue incidence in the District of Tawau over a period of 12 years, from 2006 to 2017. A forecasting model purposed to predict future outbreaks in Tawau was then developed using this data. Monthly dengue incidence data, mean temperature, maximum temperature, minimum temperature, mean relative humidity and mean rainfall over a period of 12 years from 2006 to 2017 in Tawau were retrieved from Tawau District Health Office and the Malaysian Meteorological Department. Cross-correlation analysis between weather predictors, lagged terms of weather predictors and dengue incidences established statistically significant cross-correlation between lagged periods of weather predictors-namely maximum temperature, mean relative humidity and mean rainfall with dengue incidence at time lags of 4-6 months. These variables were then employed into 3 different methods: a multivariate Poisson regression model, a Seasonal Autoregressive Integrated Moving Average (SARIMA) model and a SARIMA with external regressors for selection. Three models were selected but the SARIMA with external regressors model utilising maximum temperature at a lag of 6 months (p-value:0.001), minimum temperature at a lag of 4 months (p-value:0.01), mean relative humidity at a lag of 2 months (p-value:0.001), and mean rainfall at a lag of 6 months (p-value:0.001) produced an AIC of 841.94, and a log-likelihood score of -413.97 establishing it as the best fitting model of the methodologies utilised. In validating the models, they were utilised to develop forecasts with the model selected with the highest accuracy of predictions being the SARIMA model predicting 1 month in advance (MAE: 7.032, MSE: 83.977). This study establishes the effect of weather on the intensity and magnitude of dengue incidence as has been previously studied. A prediction model remains a novel method of evidence-based forecasting in Tawau, Sabah. The model developed in this study, demonstrated an ability to forecast potential dengue outbreaks 1 to 4 months in advance. These findings are not dissimilar to what has been previously studied in many different countries- with temperature and humidity consistently being established as powerful predictors of dengue incidence magnitude. When used in prognostication, it can enhance- decision making and allow judicious use of resources in public health setting. Nevertheless, the model remains a work in progress- requiring larger and more diverse data.
  15. Ibrahim MI, Jusoh YR, Adam NN, Mohamad I
    Iran J Otorhinolaryngol, 2018 Jan;30(96):65-68.
    PMID: 29387667
    Introduction: Primary squamous cell carcinoma (SCC) of the thyroid gland is one of the rarest types of all reported thyroid malignancies worldwide. It is very aggressive in nature and carries a poor prognosis. The surgical resection with adjuvant radiotherapy and chemotherapy is the most recommended treatment despite its poor reported outcome.

    Case Report: A 74-year-old woman presented with a rapidly progressive neck swelling, with hoarseness and compressive symptoms. Physical examination revealed a multilobulated firm thyroid mass with unilateral vocal cord palsy. Histopathological findings confirmed the diagnosis of SCC while radiological investigations and panendoscopy findings ruled out the possibility of other primary tumors. A surgical intervention was performed; however, the patient eventually succumbed to death prior to undergoing an oncological treatment.

    Conclusion: With no standard consensus to guide the management plan, SCC of the thyroid gland presents a great challenge for the managing team to come up with the best treatment option, due to its unfavorable rate of survival.

  16. Yaacof N, Qamaruz Zaman N, Yusup Y, Yusoff S
    Environ Sci Pollut Res Int, 2019 Aug;26(23):24286-24299.
    PMID: 31214886 DOI: 10.1007/s11356-019-05517-z
    Malaysia is the second-largest producer and exporter of palm oil amounting to 39% of world palm oil production and 44% of world exports (MPOB, 2014). An enormous amount of palm oil mill effluent is released during palm oil milling, and the effluent causes a major odor problem. Many methods, such as biofiltering, can be adopted to manage the malodor. However, these methods are expensive and require high maintenance. The separation distance method can be used as an alternative due to its low cost and effectiveness. This research was conducted to verify the performance of three different methods, namely, in-field monitoring by using an olfactometer, CALPUFF model, and Gaussian plume model. Given that no research has compared the three methods, this study examined the effectiveness of the methods and determined which among them is suitable for use in Malaysia. The appropriate separation distances were 1.3 km for in-field monitoring, 1.2 km for the CALPUFF model, and 0.5 for the Gaussian plume model. These different values of separation distance were due to the various approaches involved in each method. This research determined an appropriate means to establish a proper separation distance for reducing odor nuisance in areas around palm oil mills.
  17. Al-Amshawee SKA, Yunus MYBM, Dakhil IH
    PMID: 37308631 DOI: 10.1007/s11356-023-27940-z
    Concentration polarization, which creates a thin boundary layer along the membranes in electrochemical reactors and electrodialysis-related processes, is one of the main issues. Membrane spacers provide swirling motion in the stream and distribute fluid toward the membrane, which effectively breaks the polarization layer and maximizes flux steadily. Membrane spacers and the spacer-bulk attack angle are reviewed systematically in the current study. The study then in-depth reviews a ladder-type configuration composed of longitudinal (0° attack angle) and transverse (90° attack angle) filaments, and its effects on solution flow direction and hydrodynamics. The review discovered that, at the tradeoff of high-pressure losses, a laddered spacer can provide mass transfer and mixing activity along the channel while preserving comparable patterns of concentration near the membrane wall. Pressure losses are driven by a change in the direction of velocity vectors. Dead spots in the spacer design that are created by the large contribution of the spacer manifolds can be reduced using the high-pressure drop. Laddered spacers also permit long, tortuous flow paths, which help to create turbulent flow and prevent concentration polarization. The absence of spacers produces limited mixing and broad polarization effects. A major portion of streamlines changes direction at ladder spacer strands positioned transverse to the main flow by moving in a zigzag manner up and down the filaments of the spacer. Flow at 90° is perpendicular to the transverse wires in [Formula: see text]-coordinate, no change in [Formula: see text]-coordinate.
  18. Al-Amshawee SKA, Yunus MYBM, Mohamed HS
    PMID: 37378732 DOI: 10.1007/s11356-023-28433-9
    Electrodialysis desalination is constructed with a number of anion exchange membranes (AEM), cation exchange membranes (CEM), anode, cathode, adjacent silicon gasket integrated membrane spacers, and inlet/outlet holes per cell. At the boundary among an ionic solution and an ion exchange membrane, concentration polarization develops. Spacers placed in between channel's walls function as stream baffles to increase turbulence, improve heat and mass transfer, diminish the laminar boundary layer, and lessen fouling problems. The current study offers a systematic review of membrane spacers, spacer-bulk attack angles, and irregular attack angles. Spacer-bulk attack angle is accountable for variations in the pattern and direction of stream which impact heat-mass transfer and concentration polarization. Irregular attack angles (e.g., 0°, 15°, 30°, 37°, 45°, 55°, 60°, 62°, 70°, 74°, 80°, 90°, 110°, 120°) in the present study were found to provide unique stream patterns due to the spacer's filaments being less or more transverse in respect to the primary solution direction, which may significantly alter heat transfer, mass transport, pressure drop, and overall flow dynamics. Spacer applies shear stress resulting by continuous stream tangent to the membrane exterior, which lessens polarization. In the end, 45° is concluded as the preferred attack angle that offers balanced rates of heat transfer, mass transport, and pressure drop throughout the feed channel while greatly lowering the rate of concentration polarization.
  19. Hossain MS, Roney M, Bin Mohd Yunus MY, Shariffuddin JH
    J Biomol Struct Dyn, 2023 Nov 02.
    PMID: 37916669 DOI: 10.1080/07391102.2023.2276889
    Diabetes affects millions globally and poses treatment challenges. Targeting the enzyme fructose-1,6-bisphosphatase (FBPase) in gluconeogenesis and exploring plant-based therapies offer potential solutions for improving diabetes management while supporting sustainability and medicinal advancements. Utilizing pineapple (Ananas comosus L. Merr.) waste as a source of drug precursors could be valuable for health and environmental care due to its medicinal benefits and abundant yearly biomass production. Therefore, this study conducted a virtual screening to identify potential natural compounds from pineapple that could inhibit FBPase activity. A total of 112 compounds were screened for drug-likeness and ADMET properties, and molecular docking simulations were performed on 20 selected compounds using blind docking. The lead compound, butane-2,3-diyl diacetate, was subjected to 100 ns MD simulations, revealing a binding energy of -5.4 kcal/mol comparable to metformin (-5.6 kcal/mol). The MD simulation also confirmed stable complexes with crucial hydrogen bonds. Glu20, Ala24, Thr27, Gly28, Glu29, Leu30, Val160, Met177, Asp178, and Cys179 were identified as key amino acids that stabilized the human liver FBPase-butane-2,3-diyl diacetate complex, while Tyr215 and Asp218 played a crucial role in the human liver FBPase-Metformin complex. Our study indicates that the lead compound has high intestinal solubility. Therefore, it would show rapid bloodstream distribution and effective action on the target protein, making butane-2,3-diyl diacetate a potential antidiabetic drug candidate. However, further investigations in vitro, preclinical, and clinical trials are required to thoroughly assess its efficacy and safety.Communicated by Ramaswamy H. Sarma.
  20. Huang DM, Sigid MF, Yusup Y, Fadhlullah W, Salleh S
    Mar Environ Res, 2024 Nov 12;203:106833.
    PMID: 39541794 DOI: 10.1016/j.marenvres.2024.106833
    The Strait of Malacca is well-known as an important trade route with high marine biodiversity. Among the organisms residing in the strait are the reef-building hard corals. Studies have shown that climate change and other anthropogenic stressors have induced severe degradation of coral reefs through the disruption of coral productivity and metabolisms. Moreover, in-depth investigations of causal inference of coral degradation and its correlations with potential coral-affecting physicochemical factors within the strait are limited. Hence, this study presents the analyses of the latest bi-decadal time-series trend from 1995 to 2016 of the live hard coral coverage (or live coral cover) and six coral-affecting physicochemical factors (significant wave height, sea surface salinity, particulate inorganic carbon, particulate organic carbon, turbidity, and sea surface temperature) using remote sensing and reanalysis datasets. Their potential correlations were interpreted by implementing meta- and statistical analyses of past coral surveys and remote sensing data. This study revealed the overall persistent bi-decadal decline in live hard coral coverage within the Strait of Malacca and the complex correlations among the factors that correspond to the spatial stratification of the marine environment. Among the six physicochemical factors, sea surface temperature, turbidity, and sea surface salinity were determined to be the most influential parameters on live coral cover distribution within the strait.
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