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Fulltext Non-Supported Nickel-Based Coral Sponge-Like Porous Magnetic Alloys for Catalytic Production of Syngas and Carbon Bio-Nanofilaments via a Biogas Decomposition Approach

Ali B, Tasirin SM, Aminayi P, Yaakob Z, Ali NT, Noori W

Nanomaterials (Basel), 2018 Dec 14;8(12).
PMID: 30558256 DOI: 10.3390/nano8121053

Porous Ni, Ni-Co, Ni-Fe, and Ni-Cu magnetic alloys with a morphology similar to a giant barrel sponge were synthesized via a facile co-precipitation procedure and then by hydrogen reduction treatment. For the first time, the non-supported alloys with their unique morphology were employed in catalytic biogas decomposition (CBD) at a reaction temperature of 700 °C and 100 mL min-1 to produce syngas and carbon bio-nanofilaments, and the catalysts' behavior, CH₄ and CO₂ conversion, and the carbon produced during the reaction were investigated. All of the equimolar alloy catalysts showed good activity and stability for the catalytic biogas decomposition. The highest sustainability factor (0.66) and carbon yield (424%) were accomplished with the Ni-Co alloy without any significant inactivation for six hours, while the highest carbon efficiency of 36.43 was obtained with the Ni-Co catalyst, which is considered relatively low in comparison with industry standards, indicating a low carbon production process efficiency, possibly due to the relatively high biogas flow rate. The higher activity of the Ni-Co alloy catalyst was associated with the synergistic impact between nickel and cobalt, allowing the catalyst to maintain a high stability throughout the reaction period. Moreover, highly uniform, interwoven carbon bio-nanofilaments with a parallel and fishbone structure were achieved.

Matched MeSH terms: Maintenance
Acoustially-mediated microfluidic nanofiltration through graphene films

Ang KM, Yeo LY, Hung YM, Tan MK

Nanoscale, 2017 May 18;9(19):6497-6508.
PMID: 28466906 DOI: 10.1039/c7nr01690e

We exploit the possibility of enhancing the molecular transport of liquids through graphene films using amplitude modulated surface acoustic waves (SAWs) to demonstrate effective and efficient nanoparticle filtration. The use of the SAW, which is an extremely efficient means for driving microfluidic transport, overcomes the need for the large mechanical pumps required to circumvent the large pressure drops encountered in conventional membranes for nanoparticle filtration. 100% filtration efficiency was obtained for micron-dimension particulates, decreasing to only 95% for the filtration of particles of tens of nanometers in dimension, which is comparable to that achieved with other methods. To circumvent clogging of the film, which is typical with all membrane filters, a backwash operation to flush the nanoparticles is incorporated simply by reversing the SAW-induced flow such that 98% recovery of the initial filtration rate is recovered. Given these efficiencies, together with the low cost and compact size of the chipscale SAW devices, we envisage the possibility of scaling out the process by operating a large number of devices in parallel to achieve typical industrial-scale throughputs with potential benefits in terms of substantially lower capital, operating and maintenance costs.

Matched MeSH terms: Maintenance
Neurophysiological symptoms and aspartame: What is the connection?

Choudhary AK, Lee YY

Nutr Neurosci, 2018 Jun;21(5):306-316.
PMID: 28198207 DOI: 10.1080/1028415X.2017.1288340

Aspartame (α-aspartyl-l-phenylalanine-o-methyl ester), an artificial sweetener, has been linked to behavioral and cognitive problems. Possible neurophysiological symptoms include learning problems, headache, seizure, migraines, irritable moods, anxiety, depression, and insomnia. The consumption of aspartame, unlike dietary protein, can elevate the levels of phenylalanine and aspartic acid in the brain. These compounds can inhibit the synthesis and release of neurotransmitters, dopamine, norepinephrine, and serotonin, which are known regulators of neurophysiological activity. Aspartame acts as a chemical stressor by elevating plasma cortisol levels and causing the production of excess free radicals. High cortisol levels and excess free radicals may increase the brains vulnerability to oxidative stress which may have adverse effects on neurobehavioral health. We reviewed studies linking neurophysiological symptoms to aspartame usage and conclude that aspartame may be responsible for adverse neurobehavioral health outcomes. Aspartame consumption needs to be approached with caution due to the possible effects on neurobehavioral health. Whether aspartame and its metabolites are safe for general consumption is still debatable due to a lack of consistent data. More research evaluating the neurobehavioral effects of aspartame are required.

Matched MeSH terms: Sleep Initiation and Maintenance Disorders/chemically induced; Sleep Initiation and Maintenance Disorders/diagnosis
Association between night-shift work, sleep quality and metabolic syndrome

Lim YC, Hoe VCW, Darus A, Bhoo-Pathy N

Occup Environ Med, 2018 10;75(10):716-723.
PMID: 30032104 DOI: 10.1136/oemed-2018-105104

OBJECTIVES: Occupational factors, particularly night-shift work, are attracting growing interest as a possible determinant of metabolic syndrome (MetS). This study aimed to determine the association between night-shift work and MetS, and assess whether sleep quality is a mediating factor.
METHODS: A cross-sectional study was conducted among Malaysian manufacturing workers, aged 40-65 years old. They completed a self-administered questionnaire on sociodemographics, lifestyle and family history, and the Pittsburgh Sleep Quality Index (PSQI) questionnaire. Waist circumference, blood pressure, fasting blood sugar, triglycerides and high-density lipoprotein levels were measured. Baron and Kenny's method, Sobel test and multiple mediation models with bootstrapping were used to determine whether the PSQI global score or its components mediated the association between night-shift work and MetS.
RESULTS: Of the 494 participants, 177 (36%) worked night shift and 51% were men. The prevalence of MetS was 37%. Night-shift work was independently associated with a twofold increase in the risk of MetS (adjusted OR: 1.92, 95% CI 1.24 to 2.97). However, the association between night-shift work and MetS did not appear to be modified by sex. Night-shift workers also reported significantly poorer sleep quality, longer sleep latency, shorter sleep duration, sleep disturbances and daytime dysfunction. Robust mediation analysis nonetheless showed that neither PSQI global score nor its components mediated the association between night-shift work and MetS.
CONCLUSION: Early screening and management of MetS and the development of programmes to improve sleep quality should be carried out among night-shift workers. Future research should investigate other modifiable mediators linking night-shift work and MetS.

Matched MeSH terms: Sleep Initiation and Maintenance Disorders/physiopathology*
Fulltext Factors affecting the cold flow behaviour of biodiesel and methods for improvement - a review

Edith, Odeigah, Janius, Rimfiel B., Robiah Yunus

Pertanika Journal of Science & Technology, 2012;20(1):1-14.
MyJurnal

Biodiesel is an attractive renewable energy source, which is suitable as a substitute to the non-renewablepetroleum diesel. However, it is plagued by its relatively bad cold flow behaviour. In this review, the factorsaffecting the cold flow of biodiesel, vis-à-vis the contradicting requirement of good cold flow and good ignitionproperties, are discussed. Fuel filter plugging, and crystallization of biodiesel are considered, together with thecold flow properties such as Pour Point (PP), Cloud Point (CP), Cold Filter Plugging Point (CFPP) and LowTemperature Filterability Test (LTFT). In addition, various methods used to improve the cold flow of biodieselare also presented, with a special emphasis laid on the effects of these methods in reducing the Cloud Point.Strategies to improve cold flow, and yet maintaining the good ignition quality of biodiesel, are also proposed.As far as the cold flow of biodiesel is concerned, desirable attributes of its esters are short, unsaturated andbranched carbon chains. However, these desirable attributes present opposing properties in terms of ignitionquality and oxidation stability. This is because esters with short, unsaturated and branched carbon chainspossess very good cold flow but poor ignition quality and oxidation stability. The target is therefore to producebiodiesel with good cold flow, sufficient ignition quality, and good oxidation stability. This target proves tobe quite difficult and is a major problem in biodiesel research. New frontiers in this research might be thedesign of the new cold flow improvers that is similar to those used in the petroleum diesel but is tailored forbiodiesel. Genetic modifications of the existing feedstock are also desirable but the food uses of this particularfeedstock should always be taken into consideration.

Matched MeSH terms: Maintenance
Fulltext Dynamic Optimization for Controller Tuning with Embedded Safety and Response Quality Measures

Ahamad, I.S., Choong, T.S.Y., Yunus, R., Chuah, T.G., Vassiliadis, V.S.

Pertanika Journal of Science & Technology, 2011;19(2):397-414.
MyJurnal

Controller tuning is needed to select the optimum response for the controlled process. This work presents a new tuning procedure of PID controllers with safety and response quality measures on a non-linear process model by optimization procedure, with a demonstration of two tanks in series. The model was developed to include safety constraints in the form of path constraints. The model was then solved with a new optimization solver, NLPOPT1, which uses a primal-dual interior point method with a novel non-monotone line search procedure with discretized penalty parameters. This procedure generated a grid of optimal PID tuning parameters for various switching of steadystates to be used as apredictor of PID tunings for arbitrary transitions. The interpolation of tuning parameters between the available parameters was found to be capable to produce state profiles with no violation on the safety measures, while maintaining the quality of the solution with the final set points targeted achievable.

Matched MeSH terms: Maintenance
Fulltext The effects of airflow on oven temperatures and cakes qualities

Shahapuzi, N.S., Taip, F. S., Aziz, N., Ahmedov, A.

Pertanika Journal of Science & Technology, 2015;23(2):339-350.
MyJurnal

The presence of airflow during heating process is expected to increase heat uniformity in a closed heating chamber. Circulation of hot air increases the percentage of convective heat transfer. In this study effects of airflow on oven temperature, cake temperature and several cake qualities were investigated. Experimental studies were conducted in convective oven using two different baking modes; with and without airflow. During baking, oven temperatures and internal cake temperature were measured, and images of cake expansion were captured. Results of the study showed that the presence of airflow could maintain the oven temperature within a small range of set point temperature. Temperature in the oven exhibited ±5.5°C fluctuation, approximately 3.5% overshoot that occurred continuously during baking with airflow. On the contrary, higher overshoot (ranging from 15 to 30%) was observed in oven temperature without airflow. Airflow also showed a significant effect (p

Matched MeSH terms: Maintenance
Fulltext Maintenance performance measurement: a review

Hasnida Abdul Samat, Shahrul Kamaruddin, Ishak Abdul Azid

Pertanika Journal of Science & Technology, 2011;19(2):199-211.
MyJurnal

Maintenance is a vital system in a manufacturing company. The maintenance objectives are to ensure that the machine is in good condition, serviceable and safe to be operated in producing quality products. However, the system usually imposes a high cost system due to its ineffective activities. Therefore, this paper was written to review the factors affecting the maintenance effectiveness and methods used to measure its performance. In this paper, maintenance performance measurement methods are categorized into three groups, based on holistic, machine, and value factors. Each group is discussed based on the principles and techniques of the maintenance performance measurement methods, along with the example of its applications in the industry. The most common methods used are the holistic approach, overall equipment effectiveness (OEE), and balance score-card (BSC). These various methods have their own benefits and drawbacks, according to the area of measurement.

Matched MeSH terms: Maintenance
Fulltext Microstructure analysis, physical and thermal properties of al2o3-al2tio5 functionally graded ceramics for the application of car brake rot

Oo, Z., Sujan, D., Rong Kimberly, F. P

Pertanika Journal of Science & Technology, 2015;23(1):153-161.
MyJurnal

Aluminium titanate (AT) (Al2TiO5) is a promising engineering material because of its low thermal expansion coefficient, excellent thermal shock resistance, good refractoriness and non-wetting with most metals. Functionally graded material (FGM) is generally a particulate composite with continuously varying volume fractions. FGMs are alternative materials for dental implants, building materials and ballistic protection. It has been of great interest to future engines, internal combustion engines, metal cutting and other high temperature engineering application. There has been a demand for an adequate disc brake that requires less maintenance in the automotive manufacturing industry. FGM, the next evolution of layered structure, consists of graded compositions that are dispersed across the ceramic which produces a gradual improvement in the properties across the ceramic at a steady pace.

Matched MeSH terms: Maintenance
Fulltext Vegetative swale for treatment of stormwater runoff from construction site

Ismail, A. F., Sapari, N., Abdul Wahab, M. M.

Pertanika Journal of Science & Technology, 2014;22(1):55-64.
MyJurnal

Land development, especially construction works, increase storm water volumes and pollution loads into rivers and lakes. The temporary drainage system at construction sites, particularly during the construction stage discharges a large amount of pollutants that can damage the aquatic system of the receiving water bodies. The potential of vegetative swale to alleviate this problem was evaluated. The size of the constructed vegetative swale was 7cm deep, 400cm long and 15cm wide at the bottom, and 17cm wide at the top. The experiment was conducted batch wise by filling the storage tank with the run-off water from the construction site. The water was allowed to flow through a pipe into the retention basin to maintain uniform flow before it entered the swale. The study showed that the run-off infiltrated through the soil at a rate of 489.6 mm/hr. Samples of surface run-off and infiltration water were collected at the end and the bottom of the swale. The results indicate that chemical oxygen demand (COD), total suspended solid (TSS), turbidity, iron and zinc were reduced by 85.4%, 80.8%, 36.4%, 52.8% and 96.0%, respectively, by surface flow and 91.1%, 98.8%, 58.2% 55.5% and 98.1%, respectively, by infiltration. Removal of nitrate and phosphorus by the planted vegetation was 69.4% and 21.1%, respectively, by infiltration. However, nutrient removal by surface flow was negligible. In conclusion, the vegetative swale was able to improve the water quality of the storm water run-off from the construction site from Class V to Class III, according to the Interim National Water Quality Standards for Malaysia.

Matched MeSH terms: Maintenance
Fulltext Trend analysis of water quality at Sungai Sarawak

Yuhani Jamian, Zainap Lamat, Nurazura Rali

Pertanika Journal of Science & Technology, 2017;25(105):55-62.
MyJurnal

Sungai Sarawak is the most important river in Sarawak. This study was aimed at assessing water quality in the selected stations from Satok bridge to the downstream, Muara Tebas, located along Sungai Sarawak. Water quality trend analysis was conducted to determine the correlation between the water quality parameters. Trend analysis was carried out using Mann-Kendall Test because data collected was non-parametric. Next, Spearman rank was used in order to determine the correlation between parameters. The results obtained and the observation made in this study reveals that the trend exists only for Chemical Oxygen Value (COD). But there are trends for Biochemical Oxygen Demand, (BOD), Dissolved Oxygen (DO), Total Suspended Solid (TSS), Ammoniacal Nitrogen (NH4N) and Turbidity to decrease or increase with no trends between 2007 and 2011. The correlation between parameters is not very strong because there are many determinants of water quality parameters. The result from this study would provide useful information for water quality management in order to maintain and improve the water quality of Sungai Sarawak.

Matched MeSH terms: Maintenance
Fulltext Fuzzy-controlled humidity variation by Silica gel and Nitrogen gas in an atmospheric chamber

Ali Ghahraei, Nurul Amziah Md Yunus, Izhal Abdul Halin, Nasri Sulaiman

Pertanika Journal of Science & Technology, 2017;25(102):133-142.
MyJurnal

Controlled humidity environment is of significance in many scientific researches and experiments. In most laboratory-scale atmospheric chambers, an electrical temperature-based control system is used to adjust humidity. Since these chambers are not affordable in every laboratory, other low cost chambers using nitrogen gas or silica gel are used to adjust humidity. In this paper, a mechanism was developed to control the relative humidity in closed lab-scale chambers. Humidification is done by spraying water through a blower fan while de-humidification is by pumping air through silica gel as well as nitrogen gas injection. A Mamdani type fuzzy controller was designed to control the components and relative humidity. The results show the proposed system and controller can adjust and maintain relative humidity from 41% to 100% with maximum overshoot of 1% and the maximum range of error of steady state of 1.2 %.

Matched MeSH terms: Maintenance
Fulltext Multisensor automatic balancing model for DARwIn-OP on uneven terrain

Muhamad Khuzaifah Ismail, Meng Cheng Lau, Mohammad Faidzul Nasrudin, Haslina Arsha

Pertanika Journal of Science & Technology, 2017;25(106):181-188.
MyJurnal

The walking of a humanoid robot needs to be robust enough in order to maintain balance in a dynamic environment especially on uneven terrain. A walking model based on multi-sensor is proposed for a Robotis DARwIn-OP robot named as Leman. Two force sensitive resistor (FSRs) on both feet equipped to Leman to estimate the zero moment point (ZMP) alongside with accelerometer and gyrosensor embedded in the body for body state estimation. The results show that the FSRs can successfully detect the unbalanced walking event if the protuberance exists on the floor surface and the accelerometer and gyrosensor (Inertial Measurement Unit, IMU) data are recorded to tune the balancing parameter in the model.

Matched MeSH terms: Maintenance
Fulltext DC-link capacitor voltage regulation with effort-reduction fuzzy logic control for three-level inverter-based shunt active power filter

Nashiren Farzilah, Mailah, Yap Hoon, Mohd Amran, Mohd Radzi

Pertanika Journal of Science & Technology, 2017;25(102):11-20.
MyJurnal

Shunt active power filter (SAPF) is the most effective solution for current harmonics. In its controller, DC-link capacitor voltage regulation algorithm with either proportional-integral (PI) or fuzzy logic control (FLC) technique has played a significant role in maintaining a constant DC voltage across all the DC-link capacitors. However, PI technique performs poorly with high overshoot and significant time delay under dynamic state conditions, as its parameters are difficult to be tuned without requiring complete knowledge of the designated system. Although FLC technique has been developed to overcome limitations of PI technique, it is mostly developed with high complexity thereby increases computational burden of the designed controller. This paper presents a fuzzy-based DC-link capacitor voltage regulation algorithm with reduced computational efforts to enhance performance of three-phase three-level neutralpoint diode clamped (NPC) inverter-based SAPF in overall DC-link voltage regulation. The proposed method is called effort-reduction FLC technique. The proposed algorithm is developed and evaluated in MATLAB-Simulink. Moreover, conventional algorithm with PI technique is tested for comparison purposes. Simulation results have confirmed improvement achieved by the proposed algorithm in comparison to the conventional algorithm.

Matched MeSH terms: Maintenance
Fulltext A review: methodologies review of magnetic water treatment as green approach of water pipeline system

Athirah Othman, Johan Sohaili, Nur Sumaiyyah Supian

Pertanika Journal of Science & Technology, 2019;27(1):281-296.
MyJurnal

This review is aimed to present an in-depth review of several methodologies on magnetic
water treatment (MWT) that are employed as scale treatment in water pipeline and to
critically discuss each method in order to determine the best outcome of MWT. The
magnetically assisted water in pipeline in various applications are presented, argued and
best variables are listed according to the performance of each MWT. The advantages and
limitations of MWT are discussed and the main outcome from the review summarize the
best method in MWT, especially in effectiveness of treating scale in terms of sustained
environment benefits. Magnetic field application in water treatment has the potential to
improve the water pipeline performance and lifetime. The application is also significant in
controlling the growth of scale in upcoming system. Both of these benefits lead to healthier
water treatment, increasing and maintaining the lifetime and performance of water system.

Matched MeSH terms: Maintenance
Fulltext In vitro and In vivo Antioxidant Evaluation and Estimation of Total Phenolic, Flavonoidal Content of Mimosa pudica L

Patro G, Bhattamisra SK, Mohanty BK, Sahoo HB

Pharmacognosy Res, 2016;8(1):22-8.
PMID: 26941532 DOI: 10.4103/0974-8490.171099

OBJECTIVE: Mimosa pudica Linn. (Mimosaceae) is traditionally used as a folk medicine to treat various ailments including convulsions, alopecia, diarrhea, dysentery, insomnia, tumor, wound healing, snake bite, etc., Here, the study was aimed to evaluate the antioxidant potential of M. pudica leaves extract against 2, 2-diphenyl-1-picrylhydrazyl (DPPH) (in vitro) and its modulatory effect on rat brain enzymes.
MATERIALS AND METHODS: Total phenolic, flavonoid contents, and in vitro antioxidant potential against DPPH radical were evaluated from various extracts of M. pudica leaves. In addition, ethyl acetate extract of Mimosa pudica leaves (EAMP) in doses of 100, 200, and 400 mg/kg/day were administered orally for 7 consecutive days to albino rats and evaluated for the oxidative stress markers as thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) from rat brain homogenate.
RESULTS: The ethyl acetate extract showed the highest total phenolic content and total flavonoid content among other extracts of M. pudica leaves. The percentage inhibition and IC50 value of all the extracts were followed dose-dependency and found significant (P < 0.01) as compared to standard (ascorbic acid). The oxidative stress markers as SOD, CAT, and GSH were increased significantly (P < 0.01) at 200 and 400 mg/kg of EAMP treated animals and decreased significantly the TBARS level at 400 mg/kg of EAMP as compared to control group.
CONCLUSION: These results revealed that the ethyl acetate extract of M. pudica exhibits both in vitro antioxidant activity against DPPH and in vivo antioxidant activity by modulating brain enzymes in the rat. This could be further correlated with its potential to neuroprotective activity due to the presence of flavonoids and phenolic contents in the extract.
SUMMARY: Total phenolic, flavonoid contents and in-vitro antioxidant potential were evaluated from various extracts of M. pudica leaves. Again, in-vivo antioxidant evaluation from brain homogenate on oxidative stress markers as TBARS, SOD, CAT and GSH from rat was investigated. Our findings revealed that M. pudica possesses both in-vitro and in-vivo antioxidant activity due to presence of phenolics and flavonoids.
KEYWORDS: 2; 2-diphenyl-1-picrylhydrazyl; Brain homogenate; Flavonoids; Mimosa pudica; Oxidative stress

Matched MeSH terms: Sleep Initiation and Maintenance Disorders
Fulltext Potential Nutraceutical Benefits of In Vivo Grown Saffron (Crocus sativus L.) As Analgesic, Anti-inflammatory, Anticoagulant, and Antidepressant in Mice

Khan A, Muhamad NA, Ismail H, Nasir A, Khalil AAK, Anwar Y, et al.

Plants (Basel), 2020 Oct 22;9(11).
PMID: 33105854 DOI: 10.3390/plants9111414

Crocus sativus, a medicinally important herbaceous plant, has been traditionally used to cure coughs, colds, insomnia, cramps, asthma, and pain. Moreover, the therapeutic applications of saffron include its immunomodulatory and anticancer properties. The current experimental analysis was performed to explore the potential nutraceutical efficacy of corm, leaf, petal, and stigma of saffron ethanolic extracts as analgesic, anti-inflammatory, anticoagulant, and antidepressant using hot plate, carrageenan-induced paw edema, capillary tube and forced swim test, respectively in mice. The results indicated that among all the extracts, stigma ethanolic extract (SEE) represented maximum latency activity (72.85%) and edema inhibition (77.33%) followed by petal ethanolic extract (PEE) with latency activity and edema inhibition of 64.06 and 70.50%, respectively. Corm ethanolic extract (CEE) and leaf ethanolic extract (LEE) displayed mild analgesic activity of 22.40% and 29.07%, respectively. Additionally, LEE (53.29%) and CEE (47.47%) exhibited mild to moderate response against inflammation. The coagulation time of SEE (101.66 s) was almost equivalent to the standard drug, aspirin (101.66 s), suggesting a strong anticoagulant effect followed by PEE (86.5 s). LEE (66.83 s) represented moderate inhibitory effect on coagulation activity while CEE (42.83 s) showed neutral effect. Additionally, PEE and SEE also expressed itself as potential antidepressants with immobility time ≤76.66 s, while CEE (96.50 s) and LEE (106.83 s) indicated moderate to mild antidepressant efficacy. Based on the in vivo activities, saffron extract, particularly SEE and PEE, can be used as a potential nutraceutical and therapeutic agent due to its significant pharmacological activities.

Matched MeSH terms: Sleep Initiation and Maintenance Disorders
Fulltext Improved Power System Stability Using Backtracking Search Algorithm for Coordination Design of PSS and TCSC Damping Controller

Niamul Islam N, Hannan MA, Mohamed A, Shareef H

PLoS One, 2016;11(1):e0146277.
PMID: 26745265 DOI: 10.1371/journal.pone.0146277

Power system oscillation is a serious threat to the stability of multimachine power systems. The coordinated control of power system stabilizers (PSS) and thyristor-controlled series compensation (TCSC) damping controllers is a commonly used technique to provide the required damping over different modes of growing oscillations. However, their coordinated design is a complex multimodal optimization problem that is very hard to solve using traditional tuning techniques. In addition, several limitations of traditionally used techniques prevent the optimum design of coordinated controllers. In this paper, an alternate technique for robust damping over oscillation is presented using backtracking search algorithm (BSA). A 5-area 16-machine benchmark power system is considered to evaluate the design efficiency. The complete design process is conducted in a linear time-invariant (LTI) model of a power system. It includes the design formulation into a multi-objective function from the system eigenvalues. Later on, nonlinear time-domain simulations are used to compare the damping performances for different local and inter-area modes of power system oscillations. The performance of the BSA technique is compared against that of the popular particle swarm optimization (PSO) for coordinated design efficiency. Damping performances using different design techniques are compared in term of settling time and overshoot of oscillations. The results obtained verify that the BSA-based design improves the system stability significantly. The stability of the multimachine power system is improved by up to 74.47% and 79.93% for an inter-area mode and a local mode of oscillation, respectively. Thus, the proposed technique for coordinated design has great potential to improve power system stability and to maintain its secure operation.

Matched MeSH terms: Maintenance
Fulltext Provider cost of treating oral potentially malignant disorders and oral cancer in Malaysian public hospitals

Raman S, Shafie AA, Abraham MT, Shim CK, Maling TH, Rajendran S, et al.

PLoS One, 2021;16(5):e0251760.
PMID: 33984051 DOI: 10.1371/journal.pone.0251760

Oral cancer has been recognized as a significant challenge to healthcare. In Malaysia, numerous patients frequently present with later stages of cancers to the highly subsidized public healthcare facilities. Such a trend contributes to a substantial social and economic burden. This study aims to determine the cost of treating oral potentially malignant disorders (OPMD) and oral cancer from a public healthcare provider's perspective. Medical records from two tertiary public hospitals were systematically abstracted to identify events and resources consumed retrospectively from August 2019 to January 2020. The cost accrued was used to estimate annual initial and maintenance costs via two different methods- inverse probability weighting (IPW) and unweighted average. A total of 86 OPMD and 148 oral cancer cases were included. The initial phase mean unadjusted cost was USD 2,861 (SD = 2,548) in OPMD and USD 38,762 (SD = 12,770) for the treatment of cancer. Further annual estimate of initial phase cost based on IPW method for OPMD, early and late-stage cancer was USD 3,561 (SD = 4,154), USD 32,530 (SD = 12,658) and USD 44,304 (SD = 16,240) respectively. Overall cost of late-stage cancer was significantly higher than early-stage by USD 11,740; 95% CI [6,853 to 16,695]; p< 0.001. Higher surgical care and personnel cost predominantly contributed to the larger expenditure. In contrast, no significant difference was identified between both cancer stages in the maintenance phase, USD 700; 95% CI [-1,142 to 2,541]; p = 0.457. A crude comparison of IPW estimate with unweighted average displayed a significant difference in the initial phase, with the latter being continuously higher across all groups. IPW method was shown to be able to use data more efficiently by adjusting cost according to survival and follow-up. While cost is not a primary consideration in treatment recommendations, our analysis demonstrates the potential economic benefit of investing in preventive medicine and early detection.

Matched MeSH terms: Maintenance
Fulltext Association between elder abuse and poor sleep: A cross-sectional study among rural older Malaysians

Yunus RM, Wazid SW, Hairi NN, Choo WY, Hairi FM, Sooryanarayana R, et al.

PLoS One, 2017;12(7):e0180222.
PMID: 28686603 DOI: 10.1371/journal.pone.0180222

OBJECTIVES: To examine the association between elder abuse and poor sleep using a Malay validated version of Pittsburgh Sleep Quality Index (PSQI).
DESIGN: This study was divided into two phases. Phase I tested the construct validity and reliability of the Malay version of PSQI. Phase II was a population-based, cross-sectional study with a multi-stage cluster sampling method. Home-based interviews were conducted by trained personnel using a structured questionnaire, to determine exposure and outcome.
SETTING: Kuala Pilah, a district in Negeri Sembilan which is one of the fourteen states in Malaysia.
PARTICIPANTS: 1648 community-dwelling older Malaysians.
RESULTS: The Malay version of PSQI had significant test re-test reliability with intra-class correlation coefficients of 0.62. Confirmatory factor analyses revealed that one factor PSQI scale with three components (subjective sleep quality, sleep latency, and sleep disturbances) was most suitable. Cronbach's Alpha was 0.60 and composite reliability was 0.63. PSQI scores were highest among neglect (4.11), followed by physical (4.10), psychological (3.96) and financial abuse (3.60). There was a dose-response relationship between clustering of abuse and PSQI scores; 3.41, 3.50 and 3.84 for "no abuse", "1 type of abuse" and "2 types or more". Generalized linear models revealed six variables as significant determinants of sleep quality-abuse, co-morbidities, self-rated health, income, social support and gait speed. Among abuse subtypes, only neglect was significantly associated with poor sleep.
CONCLUSION: The Malay PSQI was valid and reliable. Abuse was significantly associated with poor sleep. As sleep is essential for health and is a good predictor for mortality among older adults, management of abuse victims should entail sleep assessment. Interventions or treatment modalities which focus on improving sleep quality among abuse victims should be designed.

Matched MeSH terms: Sleep Initiation and Maintenance Disorders/diagnosis; Sleep Initiation and Maintenance Disorders/epidemiology; Sleep Initiation and Maintenance Disorders/psychology*

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