Displaying publications 281 - 300 of 665 in total

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  1. Formant frequencies of Malay vowels produced by Malay children aged between 7 and 12 years
    Ting HN, Zourmand A, Chia SY, Yong BF, Abdul Hamid B
    J Voice, 2012 Sep;26(5):664.e1-6.
    PMID: 22285457 DOI: 10.1016/j.jvoice.2011.08.008
    The formant frequencies of Malaysian Malay children have not been well studied. This article investigates the first four formant frequencies of sustained vowels in 360 Malay children aged between 7 and 12 years using acoustical analysis. Generally, Malay female children had higher formant frequencies than those of their male counterparts. However, no significant differences in all four formant frequencies were observed between the Malay male and female children in most of the vowels and age groups. Significant differences in all formant frequencies were found across the Malay vowels in both Malay male and female children for all age groups except for F4 in female children aged 12 years. Generally, the Malaysian Malay children showed a nonsystematic decrement in formant frequencies with age. Low levels of significant differences in formant frequencies were observed across the age groups in most of the vowels for F1, F3, and F4 in Malay male children and F1 and F4 in Malay female children.
    Matched MeSH terms: Analysis of Variance
  2. Production of biofuel from waste cooking palm oil using nanocrystalline zeolite as catalyst: process optimization studies
    Taufiqurrahmi N, Mohamed AR, Bhatia S
    Bioresour Technol, 2011 Nov;102(22):10686-94.
    PMID: 21924606 DOI: 10.1016/j.biortech.2011.08.068
    The catalytic cracking of waste cooking palm oil to biofuel was studied over different types of nano-crystalline zeolite catalysts in a fixed bed reactor. The effect of reaction temperature (400-500 °C), catalyst-to-oil ratio (6-14) and catalyst pore size of different nanocrystalline zeolites (0.54-0.80 nm) were studied over the conversion of waste cooking palm oil, yields of Organic Liquid Product (OLP) and gasoline fraction in the OLP following central composite design (CCD). The response surface methodology was used to determine the optimum value of the operating variables for maximum conversion as well as maximum yield of OLP and gasoline fraction, respectively. The optimum reaction temperature of 458 °C with oil/catalyst ratio=6 over the nanocrystalline zeolite Y with pore size of 0.67 nm gave 86.4 wt% oil conversion, 46.5 wt% OLP yield and 33.5 wt% gasoline fraction yield, respectively. The experimental results were in agreement with the simulated values within an experimental error of less than 5%.
    Matched MeSH terms: Analysis of Variance
  3. Fulltext Stages of change and health-related quality of life among employees of an institution
    Liau SY, Shafie AA, Ibrahim MI, Hassali MA, Othman AT, Mohamed MH, et al.
    Health Expect, 2013 Jun;16(2):199-210.
    PMID: 21645189 DOI: 10.1111/j.1369-7625.2011.00702.x
    BACKGROUND: Transtheoretical Model of change has been used successfully in promoting behaviour change.

    OBJECTIVE: To examine the relationships between health-related quality of life (HRQoL) scores with the stages of change of adequate physical activity and fruit and vegetables intake.

    DESIGN: This was a cross-sectional study conducted among employees of the main campus and Engineering campus of Universiti Sains Malaysia (USM) during October 2009 and March 2010.

    MAIN VARIABLES STUDIED: Data on physical activity and fruit and vegetable intake was collected using the WHO STEPS instrument for chronic disease risk factors surveillance. The Short Form-12 health survey (SF-12) was used to gather information on participants' HRQoL. The current stages of change are measured using the measures developed by the Pro-Change Behaviour Systems Incorporation.

    STATISTICAL ANALYSIS: One way ANOVA and its non-parametric equivalent Kruskal-Wallis were used to compare the differences between SF-12 scores with the stages of change.

    RESULTS: A total of 144 employees were included in this analysis. A large proportion of the participants reported inadequate fruits and vegetable intake (92.3%) and physical activity (84.6%). Mean physical and mental component scores of SF-12 were 50.39 (SD = 7.69) and 49.73 (SD = 8.64) respectively. Overall, there was no statistical significant difference in the SF-12 domains scores with regards to the stages of change for both the risk factors.

    CONCLUSIONS: There were some evidence of positive relationship between stages of change of physical activity and fruit and vegetable intake with SF-12 scores. Further studies need to be conducted to confirm this association.

    Matched MeSH terms: Analysis of Variance
  4. Differences in physician attitudes towards patient-centredness: across four medical specialties
    Chan CM, Ahmad WA
    Int J Clin Pract, 2012 Jan;66(1):16-20.
    PMID: 22171901 DOI: 10.1111/j.1742-1241.2011.02831.x
    Aims: There is limited study on patient-centred attitudes with regards to the patient–physician relationship in physicians. The objective of this study was to examine and compare physician attitudes toward patient-centredness in four different medical settings.
    Methods: The present study utilised a cross-sectional survey design and purposive sampling to recruit physicians from a single academic medical centre via face-to-face interviews. Patient-centred attitudes of physicians specialising in surgery, oncology, obstetrics and gynaecology and primary care
    (N = 78) were compared on the Patient–Practitioner Orientation Scale (PPOS) using an independent one-way analysis of variance (ANOVA). The four medical
    specialties comprised the four levels, with role orientation (patient-centred orientation vs. doctor-centred orientation) as the dependent measure.
    Results: A significant level of difference (p < 0.001) was found between the four specialisations:
    oncologists were found to have the highest level of patient-centeredness, followed by obstetricians & gynaecologists and primary care physicians, with surgeons being the least patient-centred among specialisations sampled.
    Conclusion: These data are the first from the South-East Asian region to demonstrate differences in
    physician attitudes between medical specialties. Our findings prompt further investigation and confirmation as to whether physicians with particular attitudinal traits are attracted to any particular specialties of medicine, or if physician attitudes are acquired through professional experience and training. In addition, this study offers better insight into the attitudinal differences of physician between medical specialities.
    Questionnaire: Patient–Practitioner Orientation Scale; PPOS
    Matched MeSH terms: Analysis of Variance
  5. Fulltext A randomized, double-blind, placebo-controlled trial on the effect of long-acting testosterone treatment as assessed by the Aging Male Symptoms scale
    Ho CC, Tong SF, Low WY, Ng CJ, Khoo EM, Lee VK, et al.
    BJU Int, 2012 Jul;110(2):260-5.
    PMID: 22093057 DOI: 10.1111/j.1464-410X.2011.10755.x
    Study Type - Therapy (RCT). Level of Evidence 1b. What's known on the subject? and What does the study add? Testosterone deficiency syndrome can be treated with testosterone replacement in the form of injectable, transdermal, buccal and oral preparations. Long-acting i.m. testosterone undecanoate 1000 mg, which is given at 10-14 week intervals, has been shown to be adequate for sustaining normal testosterone levels in hypogonadal men. This study confirms that long-acting i.m. testosterone undecanoate is effective in improving the health-related quality of life in men with testosterone deficiency syndrome as assessed by the improvement in the Aging Male Symptoms scale. Testosterone treatment can be indicated in men who have poor health-related quality of life resulting from testosterone deficiency syndrome.
    Matched MeSH terms: Analysis of Variance
  6. Evaluation of the marginal fit of a zirconia ceramic computer-aided machined (CAM) crown system
    Baig MR, Tan KB, Nicholls JI
    J Prosthet Dent, 2010 Oct;104(4):216-27.
    PMID: 20875526 DOI: 10.1016/S0022-3913(10)60128-X
    The marginal fit of crowns is a concern for clinicians, and there is no conclusive evidence of any one margin configuration yielding better results than others in terms of marginal fit.
    Matched MeSH terms: Analysis of Variance
  7. A packed bed membrane reactor for production of biodiesel using activated carbon supported catalyst
    Baroutian S, Aroua MK, Raman AA, Sulaiman NM
    Bioresour Technol, 2011 Jan;102(2):1095-102.
    PMID: 20888219 DOI: 10.1016/j.biortech.2010.08.076
    In this study, a novel continuous reactor has been developed to produce high quality methyl esters (biodiesel) from palm oil. A microporous TiO2/Al2O3 membrane was packed with potassium hydroxide catalyst supported on palm shell activated carbon. The central composite design (CCD) of response surface methodology (RSM) was employed to investigate the effects of reaction temperature, catalyst amount and cross flow circulation velocity on the production of biodiesel in the packed bed membrane reactor. The highest conversion of palm oil to biodiesel in the reactor was obtained at 70 °C employing 157.04 g catalyst per unit volume of the reactor and 0.21 cm/s cross flow circulation velocity. The physical and chemical properties of the produced biodiesel were determined and compared with the standard specifications. High quality palm oil biodiesel was produced by combination of heterogeneous alkali transesterification and separation processes in the packed bed membrane reactor.
    Matched MeSH terms: Analysis of Variance
  8. Utilization of sludge palm oil as a novel substrate for biosurfactant production
    Wan Nawawi WM, Jamal P, Alam MZ
    Bioresour Technol, 2010 Dec;101(23):9241-7.
    PMID: 20674345 DOI: 10.1016/j.biortech.2010.07.024
    This paper introduces sludge palm oil (SPO) as a novel substrate for biosurfactant production by liquid state fermentation. Potential strains of microorganism were isolated from various hydrocarbon-based sources at palm oil mill and screened for biosurfactant production with the help of drop collapse method and surface tension activity. Out of 22 isolates of microorganism, the strain S02 showed the highest bacterial growth with a surface tension of 36.2 mN/m and was therefore, selected as a potential biosurfactant producing microorganism. Plackett-Burman experimental design was employed to determine the important nutritional requirement for biosurfactant production by the selected strain under controlled conditions. Six out of 11 factors of the production medium were found to significantly affect the biosurfactant production. K(2)HPO(4) had a direct proportional correlation with the biosurfactant production while sucrose, glucose, FeSO(4), MgSO(4), and NaNO(3) showed inversely proportional relationship with biosurfactant production in the selected experimental range.
    Matched MeSH terms: Analysis of Variance
  9. The feasibility study of crude palm oil transesterification at 30 °C operation
    Sim JH, Kamaruddin AH, Bhatia S
    Bioresour Technol, 2010 Dec;101(23):8948-54.
    PMID: 20675129 DOI: 10.1016/j.biortech.2010.07.039
    The objective of this research is to investigate the potential of transesterification of crude palm oil (CPO) to biodiesel at 30 degrees C. The mass transfer limitations problem crucial at 30 degrees C due to the viscosity of CPO has been addressed. The process parameters that are closely related to mass transfer effects like enzyme loading, agitation speed and reaction time were optimized. An optimum methanol to oil substrate molar ratio at 6.5:1 was observed and maintained throughout the experiments. The optimum operating condition for the transesterification process was found at 6.67 wt% of enzyme loading and at 150 rpm of agitation speed. The corresponding initial reaction and FAME yield obtained at 6 h were 89.29% FAME yield/hr and 85.01%, respectively. The 85% FAME yield obtained at 30 degrees C operation of CPO transesterification shows that the process is potentially feasible for the biodiesel synthesis.
    Matched MeSH terms: Analysis of Variance
  10. Lipase-catalyzed dimethyl adipate synthesis: response surface modeling and kinetics
    Chaibakhsh N, Rahman MB, Basri M, Salleh AB, Abd-Aziz S
    Biotechnol J, 2010 Aug;5(8):848-55.
    PMID: 20632329 DOI: 10.1002/biot.201000063
    Dimethyl adipate (DMA) was synthesized by immobilized Candida antarctica lipase B-catalyzed esterification of adipic acid and methanol. To optimize the reaction conditions of ester production, response surface methodology was applied, and the effects of four factors namely, time, temperature, enzyme concentration, and molar ratio of substrates on product synthesis were determined. A statistical model predicted that the maximum conversion yield would be 97.6%, at the optimal conditions of 58.5 degrees C, 54.0 mg enzyme, 358.0 min, and 12:1 molar ratio of methanol to adipic acid. The R(2) (0.9769) shows a high correlation between predicted and experimental values. The kinetics of the reaction was also investigated in this study. The reaction was found to obey the ping-pong bi-bi mechanism with methanol inhibition. The kinetic parameters were determined and used to simulate the experimental results. A good quality of fit was observed between the simulated and experimental initial rates.
    Matched MeSH terms: Analysis of Variance
  11. Fulltext In vivo analgesic effect of aqueous extract of Tamarindus indica L. fruits
    Khalid S, Shaik Mossadeq WM, Israf DA, Hashim P, Rejab S, Shaberi AM, et al.
    Med Princ Pract, 2010;19(4):255-9.
    PMID: 20516700 DOI: 10.1159/000312710
    To study the effects of Tamarindus indica L. aqueous fruit extract on the antinociceptive activities in rodent models.
    Matched MeSH terms: Analysis of Variance
  12. Optimal conditions for bioremediation of oily seawater
    Zahed MA, Aziz HA, Isa MH, Mohajeri L, Mohajeri S
    Bioresour Technol, 2010 Dec;101(24):9455-60.
    PMID: 20705460 DOI: 10.1016/j.biortech.2010.07.077
    To determine the influence of nutrients on the rate of biodegradation, a five-level, three-factor central composite design (CCD) was employed for bioremediation of seawater artificially contaminated with crude oil. Removal of total petroleum hydrocarbons (TPH) was the dependent variable. Samples were extracted and analyzed according to US-EPA protocols. A significant (R(2)=0.9645, P<0.0001) quadratic polynomial mathematical model was generated. Removal from samples not subjected to optimization and removal by natural attenuation were 53.3% and 22.6%, respectively. Numerical optimization was carried out based on desirability functions for maximum TPH removal. For an initial crude oil concentration of 1g/L supplemented with 190.21 mg/L nitrogen and 12.71 mg/L phosphorus, the Design-Expert software predicted 60.9% hydrocarbon removal; 58.6% removal was observed in a 28-day experiment.
    Matched MeSH terms: Analysis of Variance
  13. Age at menarche of university students in Bangladesh: secular trends and association with adult anthropometric measures and socio-demographic factors
    Hossain MG, Islam S, Aik S, Zaman TK, Lestrel PE
    J Biosoc Sci, 2010 Sep;42(5):677-87.
    PMID: 20529410 DOI: 10.1017/S0021932010000210
    Age at menarche has been shown to be an important indicator for diseases such as breast cancer and ischaemic heart disease. The aim of the present study was to document secular trends in age at menarche and their association with anthropometric measures and socio-demographic factors in university students in Bangladesh. Data were collected from 995 students from Rajshahi University using a stratified sampling technique between July 2004 and May 2005. Trends in age at menarche were examined by linear regression analysis. Multiple regression analysis was used to assess the association of age at menarche with adult anthropometric measures and various socio-demographic factors. The mean and median age of menarche were 13.12+/-1.16 and 13.17 years, respectively, with an increasing tendency among birth-year cohorts from 1979 to 1986. Menarcheal age was negatively associated with BMI (p<0.01), but positively associated with height (p<0.05). Early menarche was especially pronounced among students from urban environments, Muslims and those with better educated mothers. Increasing age at menarche may be explained by improved nutritional status among Bangladeshi populations. Early menarche was associated with residence location at adolescence, religion and mother's education.
    Matched MeSH terms: Analysis of Variance
  14. Fulltext Accumulation of soil carbon and phosphorus contents of a rehabilitated forest
    Haruna Ahmed O, Aainaa Hasbullah N, Ab Majid NM
    ScientificWorldJournal, 2010 Oct 12;10:1988-95.
    PMID: 20953548 DOI: 10.1100/tsw.2010.196
    The world's tropical rainforests are decreasing at an alarming rate as they are converted to agricultural land, pasture, and plantations. Decreasing tropical forests affect global warming. As a result, afforestation progams have been suggested to mitigate this problem. The objective of this study was to determine the carbon and phosphorus accumulation of a rehabilitated forest of different ages. The size of the study area was 47.5 ha. Soil samples were collected from the 0-, 6-, 12-, and 17-year-old rehabilitated forest. Twenty samples were taken randomly with a soil auger at depths of 0-20 and 20-40 cm. The procedures outlined in the Materials and Methods section were used to analyze the soil samples for pH, total C, organic matter, total P, C/P ratio, yield of humic acid (HA), and cation exchange capacity (CEC). The soil pH decreased significantly with increasing age of forest rehabilitation regardless of depth. Age did not affect CEC of the rehabilitated forest. Soil organic matter (SOM), total C, and total P contents increased with age. However, C/P ratio decreased with time at 0-20 cm. Accumulation of HA with time and soil depth was not consistent. The rehabilitated forest has shown signs of being a C and P sink.
    Matched MeSH terms: Analysis of Variance
  15. Optimization of bioresource material from oil palm trunk core drying using microwave radiation; a response surface methodology application
    Amouzgar P, Khalil HP, Salamatinia B, Abdullah AZ, Issam AM
    Bioresour Technol, 2010 Nov;101(21):8396-401.
    PMID: 20639118 DOI: 10.1016/j.biortech.2010.05.061
    In this study optimization of drying oil palm trunk core lumber (OPTCL) biomass using microwave radiation was reported. Optimizing of the drying conditions using microwave, avoid burning, shrinkage and increasing the permeability of OPT was aimed to develop a new value added material. A set of experiments was designed by central composite design using response surface methodology (RSM) to statistically evaluate the findings. Three independent process variables including time (2-10 min), sample weight (300-1000 g) and input power (660-3300 W) were studied under the given conditions designed by Design Expert software. The results showed the effectiveness of microwave drying in reducing the time and better removal of moisture as compared to that of oven drying with no significant changes. Employing optimum conditions at 6.89 min of time with a microwave power set at 4 for a sample of 1000 g, predicting 14.62% of moisture content.
    Matched MeSH terms: Analysis of Variance
  16. Subcritical water liquefaction of oil palm fruit press fiber in the presence of sodium hydroxide: an optimisation study using response surface methodology
    Mazaheri H, Lee KT, Bhatia S, Mohamed AR
    Bioresour Technol, 2010 Dec;101(23):9335-41.
    PMID: 20656481 DOI: 10.1016/j.biortech.2010.07.004
    Thermal decomposition of oil palm fruit press fiber (FPF) into a liquid product (LP) was achieved using subcritical water treatment in the presence of sodium hydroxide in a high pressure batch reactor. This study uses experimental design and process optimisation tools to maximise the LP yield using response surface methodology (RSM) with central composite rotatable design (CCRD). The independent variables were temperature, residence time, particle size, specimen loading, and additive loading. The mathematical model that was developed fit the experimental results well for all of the response variables that were studied. The optimal conditions were found to be a temperature of 551 K, a residence time of 40 min, a particle size of 710-1000 microm, a specimen loading of 5 g, and a additive loading of 9 wt.% to achieve a LP yield of 76.16%.
    Matched MeSH terms: Analysis of Variance
  17. Effect of preparation conditions of activated carbon from bamboo waste for real textile wastewater
    Ahmad AA, Hameed BH
    J Hazard Mater, 2010 Jan 15;173(1-3):487-93.
    PMID: 19765899 DOI: 10.1016/j.jhazmat.2009.08.111
    This study deals with the use of activated carbon prepared from bamboo waste (BMAC), as an adsorbent for the removal of chemical oxygen demand (COD) and color of cotton textile mill wastewater. Bamboo waste was used to prepare activated carbon by chemical activation using phosphoric acid (H(3)PO(4)) as chemical agent. The effects of three preparation variables activation temperature, activation time and H(3)PO(4):precursor (wt%) impregnation ratio on the color and COD removal were investigated. Based on the central composite design (CCD) and quadratic models were developed to correlate the preparation variables to the color and COD. From the analysis of variance (ANOVA), the most influential factor on each experimental design response was identified. The optimum condition was obtained by using temperature of 556 degrees C, activation time of 2.33 h and chemical impregnation ratio of 5.24, which resulted in 93.08% of color and 73.98% of COD.
    Matched MeSH terms: Analysis of Variance
  18. Optimization of the operating parameters of a grass trimming machine
    Mallick Z
    Appl Ergon, 2010 Mar;41(2):260-5.
    PMID: 19762006 DOI: 10.1016/j.apergo.2009.07.010
    Hand-arm vibration syndrome (HAVS) is very common among the workers operating power tools and doing similar nature of work for long hours. Grass trimming is one of the operations that involves use of vibrating cutter, and results in hand-arm vibration among workers. In this study, the influence of several operating parameters (length of nylon cutting thread, engine speed and handle material) is investigated in terms of HAV. Data are analyzed via orthogonal array, main effect, signal-to-noise (S/N) ratio, and analysis of variance to determine the appropriate operating parameter levels to minimize HAV. Operating parameters under investigation are found to be influential in controlling HAV generation during grass trimming operation. Experiments are carried out for measuring hand-arm vibration using tri-axial accelerometer conforming the effectiveness of this approach. Results show that 100mm length of nylon thread, 3000+/-400rpm of engine speed and ABS handle material combination results in minimum HAV (HARM) of magnitude 2.76m/s(2). Through this study not only the optimal operating parameter levels for GTM are obtained, but also the main process parameters that affect the HAV are determined. The optimum HAV obtained through appropriate level selection of operating parameters, significantly reduces the occurrence of HAVS among the grass trimmers.
    Matched MeSH terms: Analysis of Variance
  19. Analysis and optimization of flocculation activity and turbidity reduction in kaolin suspension using pectin as a biopolymer flocculant
    Ho YC, Norli I, Alkarkhi AF, Morad N
    Water Sci Technol, 2009;60(3):771-81.
    PMID: 19657173 DOI: 10.2166/wst.2009.303
    The performance of pectin in turbidity reduction and the optimum condition were determined using Response Surface Methodology (RSM). The effect of pH, cation's concentration, and pectin's dosage on flocculating activity and turbidity reduction was investigated at three levels and optimized by using Box-Behnken Design (BBD). Coagulation and flocculation process were assessed with a standard jar test procedure with rapid and slow mixing of a kaolin suspension (aluminium silicate), at 150 rpm and 30 rpm, respectively, in which a cation e.g. Al(3+), acts as coagulant, and pectin acts as the flocculant. In this research, all factors exhibited significant effect on flocculating activity and turbidity reduction. The experimental data and model predictions well agreed. From the 3D response surface graph, maximum flocculating activity and turbidity reduction are in the region of pH greater than 3, cation concentration greater than 0.5 mM, and pectin dosage greater than 20 mg/L, using synthetic turbid wastewater within the range. The flocculating activity for pectin and turbidity reduction in wastewater is at 99%.
    Matched MeSH terms: Analysis of Variance
  20. Using response surface methodology to optimize process parameters and cross-linking agents for production of combined-cross-linked bovine serum albumin gels
    Gan CY, Alkarkhi AF, Easa AM
    J Biosci Bioeng, 2009 Apr;107(4):366-72.
    PMID: 19332294 DOI: 10.1016/j.jbiosc.2008.12.007
    D-optimal design was employed to optimize the mixture of cross-linking agents formulation: microbial transglutaminase (MTGase) and ribose, and the processing parameters (i.e. incubation and heating time) in the mixture in order to obtain combined-cross-linked bovine serum albumin gels that have high gel strength, pH close to neutral and yet medium in browning. Analysis of variance (ANOVA) showed that the contribution of quadratic term to the model over the linear was significant for pH and L* value, whereas linear model was significant for gel strength. Optimization study using response surface methodology (RSM) was performed to the mixture components and process variables and the optimum conditions obtained were: MTGase of 1.34-1.43 g/100 mL, ribose of 1.07-1.16 g/100 mL, incubation time of 5 h at 40 degrees C and heating time of 3 h at 90 degrees C.
    Matched MeSH terms: Analysis of Variance
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