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  1. Analysis of the effects and relationship of perceived handwritten signature's size, graphical complexity, and legibility with dynamic parameters for forged and genuine samples
    Ahmad SM, Ling LY, Anwar RM, Faudzi MA, Shakil A
    J Forensic Sci, 2013 May;58(3):724-31.
    PMID: 23527753 DOI: 10.1111/1556-4029.12075
    This article presents an analysis of handwritten signature dynamics belonging to two authentication groups, namely genuine and forged signature samples. Genuine signatures are initially classified based on their relative size, graphical complexity, and legibility as perceived by human examiners. A pool of dynamic features is then extracted for each signature sample in the two groups. A two-way analysis of variance (ANOVA) is carried out to investigate the effects and the relationship between the perceived classifications and the authentication groups. Homogeneity of variance was ensured through Bartlett's test prior to ANOVA testing. The results demonstrated that among all the investigated dynamic features, pen pressure is the most distinctive which is significantly different for the two authentication groups as well as for the different perceived classifications. In addition, all the relationships investigated, namely authenticity group versus size, graphical complexity, and legibility, were found to be positive for pen pressure.
    Matched MeSH terms: Analysis of Variance
  2. Fulltext Kebolehulangan respons auditori keadaan mantap pada golongan dewasa lanjut umur bermasalah pendengaran sensorineural
    Akmaliza Ali, Ellin Fariza Selamat
    Jurnal Sains Kesihatan Malaysia, 2010;8(1):19-24.
    MyJurnal
    Kajian terdahulu mendapati Respons Auditori Keadaan Mantap (ASSR) mempunyai variasi yang besar dalam meramal ambang pendengaran, manakala kebolehulangan ASSR masih kurang dilaporkan. Kajian ini bertujuan untuk menentukan kebolehulangan ASSR dalam menilai ambang pendengaran golongan dewasa lanjut umur yang bermasalah pendengaran sensorineural. Seramai 15 orang subjek berumur antara 55 hingga 75 tahun terlibat dalam kajian ini. Ambang pendengaran ditentukan menggunakan audiometri nada tulen (PTA) dan ASSR pada frekuensi 0.5, 1, 2 dan 4 kHz, di mana ASSR diulang pada 0.5 dan 1 kHz. Secara keseluruhannya, nilai ambang ASSR adalah lebih tinggi daripada PTA. ANOVA satu hala menunjukkan perbezaan antara ambang PTA dan ASSR adalah tidak signifikan pada semua frekuensi. Terdapat korelasi yang signifikan antara ambang PTA dan ambang ASSR pada 0.5 kHz (r = 0.77, p < 0.05), 1 kHz (r = 0.45, p < 0.05), 2 kHz (r = 0.58, p < 0.05) dan 4 kHz (r = 0.73, p < 0.05). Ujian t berpasangan menunjukkan tiada perbezaan signifikan antara ujian ASSR pertama dan ASSR ulangan pada frekuensi 0.5 kHz (t = 2.09, p > 0.05) dan 1 kHz (t = 0.436, p > 0.05). Korelasi Pearson menunjukkan korelasi yang sederhana di antara dua pengukuran ASSR pada 0.5 kHz (r = 0.68, p < 0.001) dan 1 kHz (r = 0.60, p < 0.001). Hasil kajian ini mendapati bahawa ambang pendengaran ASSR tidak berubah secara signifikan jika diulang uji dan ujian ASSR boleh disarankan sebagai alternatif kepada PTA dalam menentukan ambang pendengaran golongan dewasa lanjut usia bermasalah pendengaran sensorineural.
    Matched MeSH terms: Analysis of Variance
  3. Analysis of 2-category data from two matched samples
    Lee J
    Med J Malaysia, 1975 Dec;30(2):103-9.
    PMID: 1228374
    Matched MeSH terms: Analysis of Variance
  4. Fulltext Evaluation of Bond Strength and Load Deflection Rate of Multi-stranded Fixed Retainer Wires: AnIn-VitroStudy
    Samson RS, Varghese E, Uma E, Chandrappa PR
    Contemp Clin Dent, 2018 3 31;9(1):10-14.
    PMID: 29599576 DOI: 10.4103/ccd.ccd_632_17
    Background: Fixed orthodontic retainers must be well retained on the tooth surfaces, allow physiologic movement of teeth and exert minimal forces on the teeth to be retained. Previous studies analyzed the bond strength and amount of deflection caused due to the debonding force but not the magnitude of force needed for unit deformation.

    Aims: This study aims to evaluate and compare the bond strength and load deflection rate (LDR) of three different fixed retainer wires.

    Materials and Methods: The wires were divided into three Groups: A - three-stranded twisted ligature wire, B - Bond-A-Braid (Reliance Orthodontics), and C - three-stranded twisted lingual retainer wire (3M Unitek). Twenty models were prepared for each group with a passive 15 mm long lingual retainer wire bonded to two lower incisors. An occlusogingival force was applied to the wire until it debonded. For LDR, three-point bending test was done at 0.5 mm deflection. These forces were measured using a Universal Instron Testing Machine.

    Statistical Analysis: Mean bond strength/LDR and pairwise comparisons were analyzed with one-way ANOVA and Tukey's honest significant differencepost hoctest, respectively.

    Results: Group C exhibited the highest mean bond strength and LDR of 101.17N and 1.84N, respectively. The intergroup comparisons were all statistically significant.

    Conclusion: Compared to the other two wire types, Group C might be better retained on the teeth due to its higher bond strength. With its relatively higher LDR value, it may resist deformation from occlusal forces, thereby reducing inadvertent tooth movement and yet remain flexible enough to allow physiologic tooth movements.

    Matched MeSH terms: Analysis of Variance
  5. Fulltext Organizational commitment among public employees: a case study in a public university
    Mohamed Fajil Abdul Batau, Ahmad Shah Pakeer Mohamed
    Malaysian Journal of Social Sciences and Humanities, 2016;1(2):9-16.
    MyJurnal
    This study examines the factors that influence organizational commitment among public employees in
    residential colleges in the University of Malaya. A total of 100 employees representing 12 colleges
    responded to the questionnaires that were designed to measure their motivation and level of
    commitment. The data obtained were analyzed using correlation, analysis of variance and regression
    analysis were used in order to achieve the objectives of the study. The findings of this study indicated
    that there are significant and positive relationships between all factors (employment compensation,
    training and development, career development and management support) with organization
    commitment. Furthermore, the findings also showed a directional relationship between independent
    and dependent variables by which the public employees at the colleges have positive commitment to
    the organization when the management provides attractive training and development, career
    development and good management support. In addition, the findings indicated that career
    development was the most dominant factor influencing organizational commitment followed by
    training development and job compensation. However, management support factor does not affect the
    organizational commitment among public employees compared to the other factors.
    Matched MeSH terms: Analysis of Variance
  6. Contactless Visualization of Latent Fingerprints on Nonporous Curved Surfaces of Circular Cross Section-A Statistical Evaluation on the Materials as Plane Mirror
    Low WZ, Khoo BE, Abdullah AFLB
    J Forensic Sci, 2018 Jul;63(4):1092-1098.
    PMID: 29178492 DOI: 10.1111/1556-4029.13702
    A new contactless technique for latent fingerprint visualization on nonporous curved surfaces of circular cross section was introduced by Low et al. (1). The technique utilizes a plane mirror to convey the light rays toward the inspected surfaces for latent fingerprint visualization. This research activity came up as an extension of the previous study which utilized an aluminum plate as the plane mirror to illuminate the inspected surfaces. Dulling spray was used to increase the diffuse component of the reflective aluminum plate. However, the amount of dulling spray will affect the uniformity of the illumination on the inspected curved surfaces. In this study, a study on the new materials for the plane mirror was carried out. Coated aluminum, opal, and ground glass diffusers were selected as the new materials. The performance of the new materials was compared to the aluminum based on the quality of the captured images on various nonporous cylindrical surfaces. A statistical approach known as randomized complete block design was used to design the experiment. The quality of the captured images was obtained using Spectral Image Validation and Verification. Two-way analysis of variance and Fisher's least significant difference test were used to analyze the quality of the images. From the results of the statistical analysis, coated aluminum has the best performance compared to aluminum, opal, and ground glass diffusers.
    Matched MeSH terms: Analysis of Variance
  7. Salvinia molesta dan pistia stratiotes sebagai agen fitoremediasi dalam rawatan air sisa kumbahan
    Marlia M. Hanafiah, Nan Hamiza Syazira Megat Mohamad, Nur Izzah Hamna Abd. Aziz
    Sains Malaysiana, 2018;47:1625-1634.
    Akumulasi logam berat dan bahan pencemar ke dalam ekosistem akuatik memberi impak negatif kepada alam sekitar dan organisma akuatik. Salvinia molesta dan Pistia stratiotes merupakan spesies yang mempunyai kadar pertumbuhan yang cepat dan berkemampuan dalam mengakumulasi logam berat dan menyerap nutrien menjadikan ia sesuai digunakan untuk merawat air sisa melalui kaedah bioteknologi iaitu fitoremediasi. Kajian ini dijalankan untuk menentukan kualiti air sisa kumbahan sebelum dan selepas rawatan menggunakan kaedah fitoremediasi. Selain itu, objektif kajian ini juga adalah untuk menilai keberkesanan Salvinia molesta dan Pistia stratiotes sebagai agen fitoremediasi bagi rawatan air sisa. Sampel tumbuhan akuatik berbeza berat iaitu 10, 20 dan 30 g diuji untuk rawatan tersebut. Ujian ANOVA satu hala menunjukkan perbezaan kadar pengurangan jumlah pepejal terampai dan ammoniakal nitrogen yang bererti (p<0.05) bagi 10, 20 dan 30 g Pistia stratiotes dan Salvinia molesta sepanjang kajian dijalankan iaitu daripada hari 0 sehingga hari ke-7. Keputusan kajian juga menunjukkan 30 dan 20 g Pistia stratiotes dan Salvinia molesta dapat menyingkirkan jumlah pepejal terampai dan ammoniakal nitrogen dengan lebih cepat berbanding berat tumbuhan 10 g. Ujian ANOVA satu hala juga tidak menunjukkan perbezaan yang bererti bagi kadar pengurangan jumlah pepejal terampai dan ammoniakal nitrogen antara Pistia stratiotes dan Salvinia molesta.
    Matched MeSH terms: Analysis of Variance
  8. Morphological characterization and selection for high yielding and powdery mildew resistant pea (pisum sativum) lines
    Ajmal Iqbal, Shahen Shah, Mohammad Nisar, Abdul Ghafoor
    Sains Malaysiana, 2017;46:1727-1734.
    Twenty lines of Pisum sativum particularly developed for high yield and resistant to powdery mildew were evaluated along with two parents (Falloner and 11760-3ER) and two checks (Climex and a local cultivar) with the objectives to determine morphological characterization, yield potential and resistance to powdery mildew. On the basis of one way cluster, the 24 lines were mainly grouped into four clusters, especially on the vegetative and yield contributing traits. It was observed that the tall and high yielding lines were grouped in cluster-III while the dwarf and high yielding lines were grouped in cluster-IV. Analysis of variance (ANOVA) showed significant difference (p<0.05) in the yield of 24 pea lines. The average grain yield of the 24 pea lines ranged from 22.87 to 102.54 g. The highest grain yield was produced by PL-4 (102.54 g plant-1) followed by PL-5 (82.14 g plant-1). Of the 24 pea lines, two lines (PL-4 and PL-5) were highly resistant to powdery mildew disease. Therefore, the newly developed PL-4 and PL-5 lines were high yielding and highly resistant. Among the 19 morphological traits, six (Eigenvalue >1.0) contributed more than 80% variability among the materials.
    Matched MeSH terms: Analysis of Variance
  9. Impact of Article Page Count and Number of Authors on Citations in Disability Related Fields: A Systematic Review Article
    Ahmed A, Adam M, Ghafar NA, Muhammad M, Ebrahim NA
    Iran J Public Health, 2016 Sep;45(9):1118-1125.
    PMID: 27957456
    BACKGROUND: Citation metrics and total publications in a field has become the gold standard for rating researchers and viability of a field. Hence, stimulating demand for citation has led to a search for useful strategies to improve performance metric index. Meanwhile, title, abstract and morphologic qualities of the articles attract researchers to scientific publications. Yet, there is relatively little understanding of the citation trend in disability related fields. We aimed to provide an insight into the factors associated with citation increase in this field. Additionally, we tried to know at what page number an article might appear attractive to disability researchers needs. Thus, our focus is placed on the article page count and the number of authors contributing to the fields per article.

    METHODS: To this end, we evaluated the quantitative characteristics of top cited articles in the fields with a total citation (≥50) in the Web of Science (WoS) database. Using one-way independent ANOVA, data extracted spanning a period of 1980-2015 were analyzed, while the non-parametric data analysis uses Kruskal-Walis test.

    RESULTS: Articles with 11 to 20 pages attract more citations followed by those within the range of zero to 10. Articles with upward 21 pages are the least cited. Surprisingly, articles with more than two authors are significantly (P<0.05) less cited and the citation decreases as the number of authors increased.

    CONCLUSION: Collaborative studies enjoy wider utilization and more citation, yet discounted merit of additional pages and limited collaborative research in disability field is revealed in this study.

    Matched MeSH terms: Analysis of Variance
  10. Estimates of genetic parameters of certain characters in Hevea brasiliensis
    Tan H, Mukherjee TK, Subramaniam S
    Theor Appl Genet, 1975 Jan;46(4):181-90.
    PMID: 24419927 DOI: 10.1007/BF00281668
    Heritability estimates of five quantitative characters, namely, yield, girth, girth increment, virgin bark and renewed bark thickness, of the breeding Phase III Hevea families have been obtained by variance component analyses. In general, the combined heritability estimates for various characters were low to moderate. The heritabilities of these characters based on female variance components, however, were high, suggesting that considerable improvement of each of the characters could be achieved in properly designed experiments.Estimates of heritability for average yields (Range: 0.11-0.34) over different years showed that the first three years' yield was adequate for predicting estimates of genetic variance for the average of five years' yield.Correlation studies on yield with other characters indicated considerable influence of environment, with genetic correlations accounting for about 0.07 to 0.36 in the characters studied.Expected direct response to selection in yield and correlated response in yield to selection for girth at opening and virgin bark thickness have been calculated using three arbitrary values of selection intensity. The efficiency of the correlated response was found to be approximately half that of the direct response. However, the indirect selection for yield using virgin bark thickness appeared to be more favourable than that using the girth at opening favoured by earlier workers.
    Matched MeSH terms: Analysis of Variance
  11. Flux model development and synthesis optimization for an enhanced GO embedded nanocomposite membrane through FFD and RSM approach
    Abdul Wahab MS, Abd Rahman S, Abu Samah R
    Heliyon, 2020 Nov;6(11):e05610.
    PMID: 33305039 DOI: 10.1016/j.heliyon.2020.e05610
    A two-level full factorial design was used to analyze several factors involved in PSF-GO-Pebax thin film nanocomposite membranes development. Permeate flux was chosen as a single response for four possible factors: Pebax selective layer concentration, amount of GO load to Pebax selective layer, Pebax-GO selective layer thickness, and amount of GO load to PSF substrate. The study is aimed at factors interaction and contribution towards the highest permeation flux via FFD and RSM approach. R2 obtained from the ANOVA is 0.9937 with Pebax concentration as the highest contributing factor. Pebax concentration-amount of GO load to PSF substrate is the only interaction contributing to the highest flux. A regression analysis concluded the study with model development and an optimized condition for the membrane design.
    Matched MeSH terms: Analysis of Variance
  12. Fulltext Design of Experiment on Concrete Mechanical Properties Prediction: A Critical Review
    Chong BW, Othman R, Putra Jaya R, Mohd Hasan MR, Sandu AV, Nabiałek M, et al.
    Materials (Basel), 2021 Apr 09;14(8).
    PMID: 33918757 DOI: 10.3390/ma14081866
    Concrete mix design and the determination of concrete performance are not merely engineering studies, but also mathematical and statistical endeavors. The study of concrete mechanical properties involves a myriad of factors, including, but not limited to, the amount of each constituent material and its proportion, the type and dosage of chemical additives, and the inclusion of different waste materials. The number of factors and combinations make it difficult, or outright impossible, to formulate an expression of concrete performance through sheer experimentation. Hence, design of experiment has become a part of studies, involving concrete with material addition or replacement. This paper reviewed common design of experimental methods, implemented by past studies, which looked into the analysis of concrete performance. Several analysis methods were employed to optimize data collection and data analysis, such as analysis of variance (ANOVA), regression, Taguchi method, Response Surface Methodology, and Artificial Neural Network. It can be concluded that the use of statistical analysis is helpful for concrete material research, and all the reviewed designs of experimental methods are helpful in simplifying the work and saving time, while providing accurate prediction of concrete mechanical performance.
    Matched MeSH terms: Analysis of Variance
  13. Fulltext Brain activation display functional asymmetry in response to action, background and tonal frequency during a pitch memory processing: an fMRI study
    Ahmad Nazlim Yusoff, Khairiah Abdul Hamid, Farah Nabila Ab Rahman, Mazlyfarina Mohamad, Khairiah Abdul Hamid, Siti Zamratol-Mai Sarah Mukari
    Jurnal Sains Kesihatan Malaysia, 2018;16(1):35-44.
    MyJurnal
    In this study, the asymmetry of the main effects of action, background and tonal frequency during a pitch memory processing
    were investigated by means of brain activation. Eighteen participants (mean age 27.6 years) were presented with low and
    high frequency tones in quiet and in noise. They listen, discriminate and recognize the target tone against the final tone
    in a series of four distracting tones. The main effects were studied using the analysis of variance (ANOVA) with action (to
    wring (rubber bulb) vs. not to wring), background (in quiet vs. in noise) and frequency (low vs. high) as the factors (and
    levels respectively). The main effect of action is in the right pre-central gyrus (PCG), in conformation with its contralateral
    behavior. The main effect of background indicated the bilateral primary auditory cortices (PAC) and is right lateralized,
    attributable to white noise. The main effect of frequency is also observed in PAC but bilaterally equal and attributable to
    low frequency tones. Despite the argument that the temporo-spectral lateralization dichotomy is not especially rigid as
    revealed by the main effect of frequency, right lateralization of PAC for the respective main effect of background clearly
    demonstrates its functional asymmetry suggesting different perceptual functionality of the right and left PAC.
    Matched MeSH terms: Analysis of Variance
  14. Fulltext Teknik peer instruction dengan analisis sumber-sumber sejarah: kekekalan kemahiran pemikiran kritikal?
    M. Kaviza
    Malaysian Journal of Social Sciences and Humanities, 2019;4(8):61-74.
    MyJurnal
    Kajian eksperimental ini bertujuan untuk mengenal pasti kesan teknik Peer Instruction dengan analisis sumber-sumber sejarah terhadap kekekalan kemahiran berfikir kritikal. Seramai 25 orang murid Tingkatan Empat melalui teknik persampelan bertujuan terlibat dalam kajian ini. Instrumen ujian pemikiran kritikal yang diadaptasi yang telah disahkan pakar penilai dan mempunyai nilai kebolehpercayaan yang baik merupakan instrumen kajian ini. Data kajian ini dianalisis secara inferensi iaitu ujian ANOVA Satu Hala dengan pengukuran berulang melalui perisian IBM SPSS. Dapatan kajian ini menunjukkan bahawa teknik Peer Instruction dengan analisis sumber-sumber sejarah adalah berkesan terhadap kekekalan kemahiran berfikir kritikal dalam kalangan murid. Implikasi kajian ini telah mencadangkan kepada guru-guru Sejarah pada semua peringkat persekolahan untuk melaksanakan teknik Peer Instruction dengan analisis sumber-sumber sejarah untuk memupuk kemahiran berfikir kritikal yang beterusan dalam kalangan murid.
    Matched MeSH terms: Analysis of Variance
  15. Fulltext MARKOWITZ THEORY IN PORTFOLIO OPTIMIZATION FOR HEAVY TAILED ASSETS
    WONG GHEE CHING, CHE MOHD IMRAN CHE TAIB
    UMT Journal of Undergraduate Research, 2019;1(3):1-14.
    MyJurnal
    This paper aims at solving an optimization problem in the presence of heavy tail behavior of financial assets. The question of minimizing risk subjected to a certain expected return or maximizing return fora given expected risk are two objective functions to be solved using Markowitz model. The Markowitz based strategies namely the mean variance portfolio, minimum variance portfolio and equally weighted portfolio are proposed in conjunction with mean and variance analysis of the portfolio. The historical prices of stocks traded at Bursa Malaysia are used for empirical analysis. We employed CAPM in order to investigate the performance of the Markowitz model which was benchmarked with risk adjusted KLSE Composite Index. We performed a backtesting study of portfolio optimization techniques defined under modern portfolio theory in order to find the optimal portfolio. Our findings showthat the mean variance portfolio outperformed the other two strategies in termsof performance of investment for heavy tailed assets.
    Matched MeSH terms: Analysis of Variance
  16. Fulltext Visual perceptual skills (non-motor) among adults in Selangor of Malaysia
    Mohd Harimi, A.R., Sumithira N., Ashwini S., Mohd Fitri, H., K., Qiu-Ting
    Medicine & Health, 2020;15(2):37-46.
    MyJurnal
    Kemahiran persepsi visual adalah penting bagi golongan dewasa untuk menjalankan aktiviti harian mereka seperti membaca, menulis dan memandu. Kajian ini dijalankan untuk menentukan kemahiran persepsi visual (bukan motor) dalam kalangan golongan dewasa di Selangor, Malaysia. Seramai 120 subjek dari Selangor yang berumur 20 hingga 59 tahun telah dipilih secara rawak dalam kajian keratan rentas ini. Kajian ini melibatkan pengukuran akuiti visual jauh dan dekat menggunakan carta Snellen dan carta penglihatan dekat Universiti Kebangsaan Malaysia (UKM), ujian saringan kognitif menggunakan soal selidik Mini Mental State Examination (MMSE) serta penilaian kemahiran persepsi visual (bukan motor) menggunakan Ujian Kemahiran Persepsi Visual (Bukan Motor)-Revised (TVPS-R). Purata umur subjek ialah 39.41+11.81 tahun. Keputusan menunjukkan purata skor TVPS-R bagi setiap sub-ujian iaitu Visual Discrimination (VD), Visual Memory (VM), Visual-Spatial Relationships (VSR), Visual Form Constancy (VFC), Visual Sequential Memory (VSM), Visual Figure-Ground (VFG) dan Visual Closure (VC) adalah 14.12+1.10, 13.42+1.58, 14.53+1.26, 12.47+1.03, 12.35+2.26, 13.67+1.64 dan 13.73+2.23. Analisis ANOVA menunjukkan skor VD, VM dan VSM dipengaruhi oleh tahap pendidikan (p
    Matched MeSH terms: Analysis of Variance
  17. Fulltext Identifying factors on agent’s sales: a case study in an apparel manufacturing company
    Nor Hasliza, Mat Desa, Siti Zamira Aida, Mat Jusoh
    Trends in Undergraduate Research, 2020;3(1):36-41.
    MyJurnal
    Agents are the most important marketing tools for company to become a successful in business. Agents not only operate as a channel to customers, but they also play an important role in providing customers with a variety of services before and after the sales. The main purpose of this study is to identify the factor influencing agent’s sales at an Apparel Manufacturing company. There are three categories of agents at the company namely, Trial agent, Basic agent and Premium agent. Based on the sales records in May 2018, the sales of product obtained by Trial Agent is lower than Basic and Premium Agents in this company. Therefore, this study aims to determine difference mean on record sales by agent among three categories of agents. This study also investigates the relationship between sales records by agents and years of experienced in business. Data was collected using questionnaire from 46 active agents at the company. Data was analyzed using One-way Analysis of Variance (ANOVA), Pearson correlation coefficient and Multiple Linear Regression. Result showed that there is a statistically significant difference in the mean sales records among the three of agent’s categories. Furthermore, there is a strong positive correlation between sales records by agent and years of experienced in business. Meanwhile, factors of knowledge and skills in business are most contributed to the agent’s sales. This study can help the company to create a strategic business plan and conducting several workshop trainings for agents to increase their knowledge and skills in business.
    Matched MeSH terms: Analysis of Variance
  18. Fulltext New Experimental Zirconia-Reinforced Rice Husk Nanohybrid Composite and the Outcome of Its Surface Roughness and Microhardness in Comparison with Commercialized Nanofilled and Microhybrid Composite Resins
    Lin GSS, Ghani NRNA, Ismail NH, Singbal K, Noorani TY, Mamat N
    Contemp Clin Dent, 2021 03 20;12(1):21-27.
    PMID: 33967533 DOI: 10.4103/ccd.ccd_298_20
    Background: An ideal composite resin should demonstrate smooth surface after polishing and high hardness value to provide long-term success. Thus, this study aimed to compare the surface roughness and microhardness of new experimental zirconia-reinforced rice husk nanohybrid composite (Zr-Hybrid) with commercialized nanofilled (Filtek-Z350-XT) and microhybrid composite (Zmack-Comp) resins before and after artificial ageing.

    Methods: One hundred and eighty standardized disc samples were prepared, of which ninety samples each were used for surface roughness and microhardness test, respectively. They were divided equally into: Group 1 (Filtek-Z350-XT), Group 2 (Zmack-Comp), and Group 3 (Zr-Hybrid). For surface roughness test, all samples were polished with aluminium oxide discs and further subdivided into aged and unaged subgroups, in which composite samples in aged subgroups were subjected to 2500 thermal cycles. Next, all the samples were subjected to surface roughness test using a contact stylus profilometer. As for microhardness test, all the aged and unaged samples were tested using a Vickers hardness machine with a load of 300 kgf for 10 s and viewed under a digital microscope to obtain microhardness value. Data were analyzed using two-way ANOVA followed by post hoc Tukey's honestly significant difference and paired sample t-test with significance level set at P = 0.05.

    Results: In both the aged and unaged groups, Zr-Hybrid showed statistically significantly lower surface roughness (P < 0.05) than Filtek-Z350-XT and Zmack-Comp, but no statistically significant difference was noted between Filtek-Z350-XT and Zmack-Comp (P > 0.05). A similar pattern was noted in microhardness test, whereby Zr-Hybrid showed the highest value (P < 0.05) followed by Filtek-Z350-XT and lastly Zmack-Comp. Besides, significant differences in surface roughness and microhardness were noted between the aged and unaged groups.

    Conclusion: Zr-Hybrid seems to demonstrate better surface roughness and microhardness value before and after artificial ageing.

    Matched MeSH terms: Analysis of Variance
  19. Exploring the effect of ultrasonic power, frequency, and load toward remediation of oil-contaminated beach and oilfield sands using ANOVA
    Mat-Shayuti MS, Tuan Ya TMYS, Abdullah MZ, Othman NH, Alias NH
    Environ Sci Pollut Res Int, 2021 Nov;28(41):58081-58091.
    PMID: 34106401 DOI: 10.1007/s11356-021-14776-8
    Despite the potential shown by previous investigations on the use of ultrasound for the remediation of oil-contaminated sand, the influence and interactions among ultrasonic parameters and oily sand are unclear, leading to possible ineffective treatment and high-power consumption. In order to improve the process efficiency, this work analyzes the effects of ultrasonic power, frequency, and load toward the cleaning of crude oil-contaminated sand, using two different sample positions and sand types. Crude oil-contaminated beach sand and produced sand from offshore oil well were used as samples. They were cleaned in custom-made ultrasonic bath reactor for 10 min with power from 30 to 120 W, frequency covering 25-60 kHz, and sand load of 10-100 g. With experimental design consisting multiple factors and levels, the interactions between factors in all possible combinations were determined using ANOVA (n = 210). From p-value based at 95% confidence interval and extensive F test, the three most significant factors were the sand type, the ultrasonic frequency, and the interaction between sand type and frequency. The best setting for suspended samples involved high frequency of 60 kHz, whereas bottom samples preferred low frequency at 28 kHz. This finding was justified when the acoustic pressure attenuation, standing wave pattern, and surface pitting/cracking were found in correlation with the cleaning results. Overall, the maximum treatment under ultrasonic bath solely gained around 60%, improvable by hybrid cleaning with other techniques such as chemical, biological, mechanical, and thermal.
    Matched MeSH terms: Analysis of Variance
  20. Optimization of Manganese Reduction in Biotreated POME onto 3A Molecular Sieve and Clinoptilolite Zeolites
    Jami MS, Rosli NS, Amosa MK
    Water Environ Res, 2016 Jun;88(6):566-76.
    PMID: 26556067 DOI: 10.2175/106143015X14362865227157
    Availability of quality-certified water is pertinent to the production of food and pharmaceutical products. Adverse effects of manganese content of water on the corrosion of vessels and reactors necessitate that process water is scrutinized for allowable concentration levels before being applied in the production processes. In this research, optimization of the adsorption process conditions germane to the removal of manganese from biotreated palm oil mill effluent (BPOME) using zeolite 3A subsequent to a comparative adsorption with clinoptilolite was studied. A face-centered central composite design (FCCCD) of the response surface methodology (RSM) was adopted for the study. Analysis of variance (ANOVA) for response surface quadratic model revealed that the model was significant with dosage and agitation speed connoting the main significant process factors for the optimization. R(2) of 0.9478 yielded by the model was in agreement with predicted R(2). Langmuir and pseudo-second-order suggest the adsorption mechanism involved monolayer adsorption and cation exchanging.
    Matched MeSH terms: Analysis of Variance
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