Displaying publications 1 - 20 of 116 in total

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  1. Ahmed N, Shihabudin M.T, Ab Rahman S
    MyJurnal
    Introduction: Hamstring tendon (HT) and bone patellar tendon bone (BPTB) are the commonly used
    autograft in an anterior cruciate ligament reconstruction surgery. The BPTB is said to have more incidence of
    anterior knee pain compared to HT. The study aimed to compare the severity of knee pain during Islamic
    prayer kneeling. Methods: A cross sectional cohort analysis of patients undergoing ACL reconstruction surgery
    using BPTB with HT autografts was conducted to determine differences in postoperative pain while kneeling
    and ability to pray in normal position. Kneeling during prayer and the ability to sit while performing prayer
    were assessed at 3rd, 4th, 5th and 6th month. Results: There were no significant differences in mean pain score
    while kneeling at 3rd, 4th, 5th and 6th month. The mean difference of patient’s ability to perform normal
    prayers for BPTB (3.56+1.16) and HT (3.30+1.05) was found insignificant. The average number of patients in
    both groups was able to pray between 3 to 4 months post operatively as full range of motion of knee is
    allowed within this period. Total 49 patients (BPTB 23, HT 26) out of 60 were able to pray normally within 4
    months post-operation. Mostly delayed due to anterior knee pain. Conclusion: There is no different in term of
    knee pain during kneeling while performing Islamic prayer between those who had their ACL reconstructed
    either using BPTB or HT autograft.
  2. Ahmed N, Shihabudin M.T., Ab Rahman S
    MyJurnal
    Hamstring tendon (HT) and bone patellar tendon bone (BPTB) are the commonly used autograft in an anterior cruciate ligament reconstruction surgery. The BPTB is said to have more incidence of anterior knee pain compared to HT. The study aimed to compare the severity of knee pain during Islamic prayer kneeling. Methods: A cross sectional cohort analysis of patients undergoing ACL reconstruction surgery using BPTB with HT autografts was conducted to determine differences in postoperative pain while kneeling and ability to pray in normal position. Kneeling during prayer and the ability to sit while performing prayer were assessed at 3rd, 4th, 5thand 6thmonth. Results:There were no significant differences in mean pain score while kneeling at 3rd, 4th, 5thand 6thmonth. The mean difference of patient’s ability to perform normal prayers for BPTB (3.56+1.16) and HT (3.30+1.05) was found insignificant. The average number of patients in both groups was able to pray between 3 to 4 months post operatively as full range of motion of knee is allowed within this period. Total 49 patients (BPTB 23, HT 26) out of 60 were able to pray normally within 4 months post-operation. Mostly delayed due to anterior knee pain. Conclusion: There is no different in term of knee pain during kneeling while performing Islamic prayer between those who had their ACL reconstructed either using BPTB or HT autograft.
  3. Settar S. Keream, Ahmed N Abdalla, Mohd Razali Bin Daud
    MyJurnal
    A new Nonlinear Dynamic Inverse (NDI) method is proposed to minimise the ripple torque in an induction motor. This method is based on field oriented with space vector pulse width modulation (SVPWM). The nonlinear dynamic inverse controller cancelled a non-desirable response of the induction motor and enhancing the performance. This cancellation attempts by careful nonlinear algebraic equations. First, a mathematical model of induction motor and decoupling between two inputs have achieved. Then the desired new dynamic is derived from implementing the proposed nonlinear dynamic inverse controller (NDIC) technique that reserves some benefits such as fast torque control, minimum ripple torque, and fast speed response. Also, the proposed method significantly reduced the torque ripple which is the major concerns of the classical hysteresis-based in direct torque control (DTC) and feedback linearization control (FLC) scheme and have an effect on the stator current distortion. Finally, the simulation results with MATLAB/Simulink achieved for a 2-hp induction motor (IM) drive. The results are verification proved that the proposed (NDI-SVPWM) system achieves smaller torque ripple about 0.4% and faster torque response than the conventional SVM-based on proportional integral (PI-DTC) method.
  4. Kadirgama K, Noor MM, Abd Alla AN
    Sensors (Basel), 2010;10(3):2054-63.
    PMID: 22294914 DOI: 10.3390/s100302054
    Metal cutting processes are important due to increased consumer demands for quality metal cutting related products (more precise tolerances and better product surface roughness) that has driven the metal cutting industry to continuously improve quality control of metal cutting processes. This paper presents optimum surface roughness by using milling mould aluminium alloys (AA6061-T6) with Response Ant Colony Optimization (RACO). The approach is based on Response Surface Method (RSM) and Ant Colony Optimization (ACO). The main objectives to find the optimized parameters and the most dominant variables (cutting speed, feedrate, axial depth and radial depth). The first order model indicates that the feedrate is the most significant factor affecting surface roughness.
  5. Nathan, S., Chowdhury, M.E.H., Anuar, Z.M.Z., Iekhsan, O., Sharifah, S.H., Ahmed, N.
    MyJurnal
    Meat quality is always subject to consumer scrutiny when purchasing from retail markets on
    mislabeling as fresh meat. Repeated cycles of ‘freeze-thaw’ degrade the quality of meat. Existing
    studies have primarily embarked on physical, chemical and biochemical changes induced by
    variable storage conditions. The authentication of fresh versus thawed meat quality can be
    further explored with the data involving a series of biochemical pathways that were largely
    well-studied in living muscle tissues. However, these pathways are less predictable in postslaughter
    condition where muscle turns to meat. In addition, there is far less known about how
    various management or environmental stimuli impact these pathways, either by substrate load
    or altered cellular environment during storage. Though the rate of post-slaughter metabolism
    is quite important in driving meat quality development, it is also fairly well established.
    Alternatively, the biochemical mechanisms responsible for the cessation of postmortem
    metabolism, or protracted carbohydrate metabolism are particularly puzzling. Likewise,
    there is little information about the relationship between volatility profiles of biomolecules
    with regards to functional groups, enzymatic activity, protein solubility and protein surface
    properties in meat during storage. The studies of these changes could be used to distinguish
    between fresh and thawed meat.
  6. Ahmed N, Azra MN
    Curr Environ Health Rep, 2022 Sep;9(3):423-435.
    PMID: 35713850 DOI: 10.1007/s40572-022-00364-6
    PURPOSE OF REVIEW: The purpose of this review is to summarize the impacts of the coronavirus disease 2019 (COVID-19) pandemic on aquaculture input supply, production, distribution, and consumption.

    RECENT FINDINGS: The COVID-19 pandemic-related lockdowns, social distancing, supply chain disruptions, and transport restrictions affect seafood production, distribution, marketing, and consumption. Recommendations are suggested to overcome these challenges. The COVID-19 has led to disruption of aquaculture practices worldwide. The pandemic has adversely affected the aquaculture input supply of fish stocking and feeding, which, in turn, has impacted aquaculture production. Moreover, the COVID-19 crisis has had adverse effects on value addition to aquaculture products, through the restrictions of seafood marketing and exporting. Aquatic food production is vulnerable to the effects of COVID-19 outbreak; hence, adaptation strategies must be developed to cope with the challenges. There is an urgent need for collaboration among key stakeholders to rebuild the supply chain of inputs and fish marketing for sustainable aquaculture practices. International agencies, donors, government and non-governmental organizations, researchers, and policymakers need to develop policies to support aquaculture production and supply chains.

  7. Rifai D, Abdalla AN, Ali K, Razali R
    Sensors (Basel), 2016;16(3):298.
    PMID: 26927123 DOI: 10.3390/s16030298
    Non-destructive eddy current testing (ECT) is widely used to examine structural defects in ferromagnetic pipe in the oil and gas industry. Implementation of giant magnetoresistance (GMR) sensors as magnetic field sensors to detect the changes of magnetic field continuity have increased the sensitivity of eddy current techniques in detecting the material defect profile. However, not many researchers have described in detail the structure and issues of GMR sensors and their application in eddy current techniques for nondestructive testing. This paper will describe the implementation of GMR sensors in non-destructive testing eddy current testing. The first part of this paper will describe the structure and principles of GMR sensors. The second part outlines the principles and types of eddy current testing probe that have been studied and developed by previous researchers. The influence of various parameters on the GMR measurement and a factor affecting in eddy current testing will be described in detail in the third part of this paper. Finally, this paper will discuss the limitations of coil probe and compensation techniques that researchers have applied in eddy current testing probes. A comprehensive review of previous studies on the application of GMR sensors in non-destructive eddy current testing also be given at the end of this paper.
  8. Rifai D, Abdalla AN, Razali R, Ali K, Faraj MA
    Sensors (Basel), 2017 Mar 13;17(3).
    PMID: 28335399 DOI: 10.3390/s17030579
    The use of the eddy current technique (ECT) for the non-destructive testing of conducting materials has become increasingly important in the past few years. The use of the non-destructive ECT plays a key role in the ensuring the safety and integrity of the large industrial structures such as oil and gas pipelines. This paper introduce a novel ECT probe design integrated with the distributed ECT inspection system (DSECT) use for crack inspection on inner ferromagnetic pipes. The system consists of an array of giant magneto-resistive (GMR) sensors, a pneumatic system, a rotating magnetic field excitation source and a host PC acting as the data analysis center. Probe design parameters, namely probe diameter, an excitation coil and the number of GMR sensors in the array sensor is optimized using numerical optimization based on the desirability approach. The main benefits of DSECT can be seen in terms of its modularity and flexibility for the use of different types of magnetic transducers/sensors, and signals of a different nature with either digital or analog outputs, making it suited for the ECT probe design using an array of GMR magnetic sensors. A real-time application of the DSECT distributed system for ECT inspection can be exploited for the inspection of 70 mm carbon steel pipe. In order to predict the axial and circumference defect detection, a mathematical model is developed based on the technique known as response surface methodology (RSM). The inspection results of a carbon steel pipe sample with artificial defects indicate that the system design is highly efficient.
  9. Imad M. Al-Ani, Ahmed N. Abired, Basma E. Mustafa, Emad N. Abdel Wahab, Marwan S. Azzubaidi
    MyJurnal
    Diabetes mellitus has become a serious warning to mankind health all over the world. The management goal of diabetes is to keep blood glucose levels as close as possible to healthy individuals. Medications used to treat diabetes are usually associated with complications and may cause different side effects. Many traditional anti-diabetic plants have become popular in the management of diabetes mellitus. Flaxseed has been used as traditional medicine for centuries.
  10. Ahmed N, Anwar S, Thet Htar T
    Front Chem, 2017;5:36.
    PMID: 28664157 DOI: 10.3389/fchem.2017.00036
    The Plasmodium falciparum Lactate Dehydrogenase enzyme (PfLDH) catalyzes inter-conversion of pyruvate to lactate during glycolysis producing the energy required for parasitic growth. The PfLDH has been studied as a potential molecular target for development of anti-malarial agents. In an attempt to find the potent inhibitor of PfLDH, we have used Discovery studio to perform molecular docking in the active binding pocket of PfLDH by CDOCKER, followed by three-dimensional quantitative structure-activity relationship (3D-QSAR) studies of tricyclic guanidine batzelladine compounds, which were previously synthesized in our laboratory. Docking studies showed that there is a very strong correlation between in silico and in vitro results. Based on docking results, a highly predictive 3D-QSAR model was developed with q(2) of 0.516. The model has predicted r(2) of 0.91 showing that predicted IC50 values are in good agreement with experimental IC50 values. The results obtained from this study revealed the developed model can be used to design new anti-malarial compounds based on tricyclic guanidine derivatives and to predict activities of new inhibitors.
  11. Yap WH, Ahmed N, Lim YM
    Lipids, 2016 10;51(10):1153-1159.
    PMID: 27540737 DOI: 10.1007/s11745-016-4186-1
    Maslinic acid is a natural pentacyclic triterpenoid which has anti-inflammatory properties. A recent study showed that secretory phospholipase A2 (sPLA2) may be a potential binding target of maslinic acid. The human group IIA (hGIIA)-sPLA2 is found in human sera and their levels are correlated with severity of inflammation. This study aims to determine whether maslinic acid interacts with hGIIA-sPLA2 and inhibits inflammatory response induced by this enzyme. It is shown that maslinic acid enhanced intrinsic fluorescence of hGIIA-sPLA2 and inhibited its enzyme activity in a concentration-dependent manner. Molecular docking revealed that maslinic acid binds to calcium binding and interfacial phospholipid binding site, suggesting that it inhibit access of catalytic calcium ion for enzymatic reaction and block binding of the enzyme to membrane phospholipid. The hGIIA-sPLA2 enzyme is also responsible in mediating monocyte recruitment and differentiation. Results showed that maslinic acid inhibit hGIIA-sPLA2-induced THP-1 cell differentiation and migration, and the effect observed is specific to hGIIA-sPLA2 as cells treated with maslinic acid alone did not significantly affect the number of adherent and migrated cells. Considering that hGIIA-sPLA2 enzyme is known to hydrolyze glyceroacylphospholipids present in lipoproteins and cell membranes, maslinic acid may bind and inhibit hGIIA-sPLA2 enzymatic activity, thereby reduces the release of fatty acids and lysophospholipids which stimulates monocyte migration and differentiation. This study is the first to report on the molecular interaction between maslinic acid and inflammatory target hGIIA-sPLA2 as well as its effect towards hGIIA-sPLA2-induced THP-1 monocyte adhesive and migratory capabilities, an important immune-inflammation process in atherosclerosis.
  12. Hoque M, Pradhan B, Ahmed N, Alamri A
    Sensors (Basel), 2021 Oct 18;21(20).
    PMID: 34696109 DOI: 10.3390/s21206896
    In Australia, droughts are recurring events that tremendously affect environmental, agricultural and socio-economic activities. Southern Queensland is one of the most drought-prone regions in Australia. Consequently, a comprehensive drought vulnerability mapping is essential to generate a drought vulnerability map that can help develop and implement drought mitigation strategies. The study aimed to prepare a comprehensive drought vulnerability map that combines drought categories using geospatial techniques and to assess the spatial extent of the vulnerability of droughts in southern Queensland. A total of 14 drought-influencing criteria were selected for three drought categories, specifically, meteorological, hydrological and agricultural. The specific criteria spatial layers were prepared and weighted using the fuzzy analytical hierarchy process. Individual categories of drought vulnerability maps were prepared from their specific indices. Finally, the overall drought vulnerability map was generated by combining the indices using spatial analysis. Results revealed that approximately 79.60% of the southern Queensland region is moderately to extremely vulnerable to drought. The findings of this study were validated successfully through the receiver operating characteristics curve (ROC) and the area under the curve (AUC) approach using previous historical drought records. Results can be helpful for decision makers to develop and apply proactive drought mitigation strategies.
  13. Biswal BM, Kareem A, Ahmed NM
    Australas Radiol, 2001 Feb;45(1):71-3.
    PMID: 11259979 DOI: 10.1046/j.1440-1673.2001.00883.x
    A patient with nasopharyngeal carcinoma developed clubbing and hypertrophic osteoarthropathy 6 months before radiological detection of secondary deposits in the lung. Another patient with nasopharyngeal carcinoma developed digital clubbing and hypertrophic osteoarthropathy 6 months after the discovery of lung metastases. Development of a paraneoplastic syndrome in the form of hypertrophic osteoarthropathy and digital clubbing is very rare. This manifestation of nasopharyngeal cancers is presented, with a short review of its biology and pathogenesis.
  14. Abdalla AN, Ali K, Paw JKS, Rifai D, Faraj MA
    Sensors (Basel), 2018 Jun 30;18(7).
    PMID: 29966367 DOI: 10.3390/s18072108
    Eddy current testing (ECT) is an accurate, widely used and well-understood inspection technique, particularly in the aircraft and nuclear industries. The coating thickness or lift-off will influence the measurement of defect depth on pipes or plates. It will be an uncertain decision condition whether the defects on a workpiece are cracks or scratches. This problem can lead to the occurrence of pipe leakages, besides causing the degradation of a company’s productivity and most importantly risking the safety of workers. In this paper, a novel eddy current testing error compensation technique based on Mamdani-type fuzzy coupled differential and absolute probes was proposed. The general descriptions of the proposed ECT technique include details of the system design, intelligent fuzzy logic design and Simulink block development design. The detailed description of the proposed probe selection, design and instrumentation of the error compensation of eddy current testing (ECECT) along with the absolute probe and differential probe relevant to the present research work are presented. The ECECT simulation and hardware design are proposed, using the fuzzy logic technique for the development of the new methodology. The depths of the defect coefficients of the probe’s lift-off caused by the coating thickness were measured by using a designed setup. In this result, the ECECT gives an optimum correction for the lift-off, in which the reduction of error is only within 0.1% of its all-out value. Finally, the ECECT is used to measure lift-off in a range of approximately 1 mm to 5 mm, and the performance of the proposed method in non-linear cracks is assessed.
  15. Pazikadin AR, Rifai D, Ali K, Malik MZ, Abdalla AN, Faraj MA
    Sci Total Environ, 2020 May 01;715:136848.
    PMID: 32040994 DOI: 10.1016/j.scitotenv.2020.136848
    The increased demand for solar renewable energy sources has created recent interest in the economic and technical issues related to the integration of Photovoltaic (PV) into the grid. Solar photovoltaic power generation forecasting is a crucial aspect of ensuring optimum grid control and power solar plant design. Accurate forecasting provides significant information to grid operators and power system designers in generating an optimal solar photovoltaic plant and to manage the power of demand and supply. This paper presents an extensive review on the implementation of Artificial Neural Networks (ANN) on solar power generation forecasting. The instrument used to measure the solar irradiance is analysed and discussed, specifically on studies that were published from February 1st, 2014 to February 1st, 2019. The selected papers were obtained from five major databases, namely, Direct Science, IEEE Xplore, Google Scholar, MDPI, and Scopus. The results of the review demonstrate the increased application of ANN on solar power generation forecasting. The hybrid system of ANN produces accurate results compared to individual models. The review also revealed that improvement forecasting accuracy can be achieved through proper handling and calibration of the solar irradiance instrument. This finding indicates that improvements in solar forecasting accuracy can be increased by reducing instrument errors that measure the weather parameter.
  16. Daraz A, Alrajhi H, Basit A, Afzal AR, Alahmadi ANM, Khan IA
    Sci Rep, 2024 Apr 24;14(1):9400.
    PMID: 38658673 DOI: 10.1038/s41598-024-60028-3
    Maintaining a power balance between generation and demand is generally acknowledged as being essential to maintaining a system frequency within reasonable bounds. This is especially important for linked renewable-based hybrid power systems (HPS), where disruptions are more likely to occur. This paper suggests a prominent modified "Fractional order-proportional-integral with double derivative (FOPIDD2) controller" as an innovative HPS controller in order to navigate these obstacles. The recommended control approach has been validated in power systems including wind, reheat thermal, solar, and hydro generating, as well as capacitive energy storage and electric vehicle. The improved controller's performance is evaluated by comparing it to regular FOPID, PID, and PIDD2 controllers. Furthermore, the gains of the newly structured FOPIDD2 controller are optimized using a newly intended algorithm terms as squid game optimizer (SGO). The controller's performance is compared to benchmarks such as the grey wolf optimizer (GWO) and jellyfish search optimization. By comparing performance characteristics such as maximum frequency undershoot/overshoot, and steadying time, the SGO-FOPIDD2 controller outperforms the other techniques. The suggested SGO optimized FOPIDD2 controller was analyzed and validated for its ability to withstand the influence of power system parameter uncertainties under various loading scenarios and situations. Without any complicated design, the results show that the new controller can work steadily and regulate frequency with an appropriate controller coefficient.
  17. Ansari SA, Devi S, Tenguria S, Kumar A, Ahmed N
    Cytokine, 2014 Aug;68(2):110-7.
    PMID: 24767863 DOI: 10.1016/j.cyto.2014.03.006
    HP0986 protein of Helicobacter pylori has been shown to trigger induction of proinflammatory cytokines (IL-8 and TNF-α) through the activation of NF-κB and also to induce Fas mediated apoptosis of human macrophage cells (THP-1). In this study, we unravel mechanistic details of the biological effects of this protein in a murine macrophage environment. Up regulation of MCP-1 and TNF-α in HP0986-induced RAW 264.7 cells occurred subsequent to the activation and translocation of NF-κB to the cell nucleus. Further, HP0986 induced apoptosis of RAW 264.7 cells through Fas activation and this was in agreement with previous observations made with THP-1 cells. Our studies indicated activation of TNFR1 through interaction with HP0986 and this elicited the aforementioned responses independent of TLR2, TLR4 or TNFR2. We found that mouse TNFR1 activation by HP0986 facilitates formation of a complex comprising of TNFR1, TRADD and TRAF2, and this occurs upstream of NF-κB activation. Furthermore, FADD also forms a second complex, at a later stage, together with TNFR1 and TRADD, resulting in caspase-8 activation and thereby the apoptosis of RAW 264.7 cells. In summary, our observations reveal finer details of the functional activity of HP0986 protein in relation to its behavior in a murine macrophage cell environment. These findings reconfirm the proinflammatory and apoptotic role of HP0986 signifying it to be an important trigger of innate responses. These observations form much needed baseline data entailing future in vivo studies of the functions of HP0986 in a murine model.
  18. Ahmed N, Loke MF, Kumar N, Vadivelu J
    Helicobacter, 2013 Sep;18 Suppl 1:1-4.
    PMID: 24011237 DOI: 10.1111/hel.12069
    We describe features of key additions to the existing pool of publicly accessible Helicobacter pylori genome sequences and sequences of Helicobacter pylori phages from April 2012 to March 2013. In addition, important studies involving H. pylori genomes, especially those pertaining to genomic diversity, disease outcome, H. pylori population structure and evolution are reviewed. High degree of homologous recombination contributes to increased diversity of H. pylori genomes. New methods of resolving H. pylori population structure to an ultrafine level led to the proposal of new subpopulations. As the magnitude of diversity in the H. pylori gene pool becomes more and more clear, geographic and demographic factors should be brought to analysis while identifying disease-specific biomarkers and defining new virulence mechanisms.
  19. Hoque MA, Pradhan B, Ahmed N, Sohel MSI
    Sci Total Environ, 2020 Nov 17.
    PMID: 33248778 DOI: 10.1016/j.scitotenv.2020.143600
    Droughts are recurring events in Australia and cause a severe effect on agricultural and water resources. However, the studies about agricultural drought risk mapping are very limited in Australia. Therefore, a comprehensive agricultural drought risk assessment approach that incorporates all the risk components with their influencing criteria is essential to generate detailed drought risk information for operational drought management. A comprehensive agricultural drought risk assessment approach was prepared in this work incorporating all components of risk (hazard, vulnerability, exposure, and mitigation capacity) with their relevant criteria using geospatial techniques. The prepared approach is then applied to identify the spatial pattern of agricultural drought risk for Northern New South Wales region of Australia. A total of 16 relevant criteria under each risk component were considered, and fuzzy logic aided geospatial techniques were used to prepare vulnerability, exposure, hazard, and mitigation capacity indices. These indices were then incorporated to quantify agricultural drought risk comprehensively in the study area. The outputs depicted that about 19.2% and 41.7% areas are under very-high and moderate to high risk to agricultural droughts, respectively. The efficiency of the results is successfully evaluated using a drought inventory map. The generated spatial drought risk information produced by this study can assist relevant authorities in formulating proactive agricultural drought mitigation strategies.
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