Displaying publications 61 - 80 of 201 in total

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  1. Abu N, Othman N, W Hon K, Nazarie WF, Jamal R
    Biomark Med, 2020 05;14(7):525-537.
    PMID: 32462912 DOI: 10.2217/bmm-2019-0241
    Background: Finding a new target or a new drug to overcome chemoresistance is difficult due to the heterogenous nature of cancer. Meta-analysis was performed to combine the analysis of different microarray studies to get a robust discovery. Materials & methods: Herein, we analyzed three microarray datasets on combination of folinic acid, fluorouracil, and oxaliplatin drugs (FOLFOX) resistance that fit our inclusion/exclusion criteria and performed a meta-analysis using the OmiCC system. Results: We identified several deregulated genes and we discovered HNF4A as a hub gene. We performed functional validation and observed that by targeting HNF4A, HCT116 cells were more sensitive toward both oxaliplatin and 5-fluorouracil significantly. Conclusion: Our findings show that HNF4A could be a potential target in overcoming FOLFOX chemoresistance in colorectal cancer.
  2. Chandrasekaran S, Baba AA, Othman N, Jayakumar CR
    Chemotherapy, 1994 Sep-Oct;40(5):357-61.
    PMID: 7956460
    The frustration and disappointment in managing advanced cancers of the nose and paranasal sinuses are well known. We report a case of a successful treatment of such a tumour in a 37-year-old soldier, using a combination of therapy including surgery, chemotherapy and radiation. Each mode of treatment is discussed.
  3. Ahmad A, Jamil SNAM, Shean Yaw Choong T, Abdullah AH, Mastuli MS, Othman N, et al.
    Polymers (Basel), 2019 Dec 04;11(12).
    PMID: 31817283 DOI: 10.3390/polym11122011
    This paper describes the preparation, characterisation, and potential application of flexible palm oil-based polyurethane foam (PUF) as a support for iron-silica (Fe-Si) adsorbent. Fe-Si/polyurethane composite (Fe-Si/PUC) was prepared by impregnating Fe-Si adsorbent onto the surface of PUF by using a novel immersion-drying method. Morphological analysis of Fe-Si/PUC proved that Fe-Si was successfully impregnated onto the surface of PUF. Compression test and thermogravimetric analysis were carried out to determine the flexibility and thermal stability of Fe-Si/PUC, respectively. The Fe-Si/PUC removed 90.0% of 10 ppm methylene blue (MB) from aqueous solution in 60 min. The reusability study showed that Fe-Si/PUC removed 55.9% of MB on the seventh cycle. Hence, the synthesis of Fe-Si/PUC opens up a new path of implementing palm oil-based PUF to assist in the recovery of an adsorbent for environmental clean-up. The mechanism of physical interaction during the impregnation of Fe-Si adsorbent onto PUF was proposed in this paper.
  4. Othman N, Tahir MS, Joremi L
    Heliyon, 2022 Nov;8(11):e11903.
    PMID: 36458305 DOI: 10.1016/j.heliyon.2022.e11903
    The Covid-19 pandemic has led to a surge in demand for oleochemicals, due to the increased demand for cleaning and disinfectants products. Since Malaysia is one of the world's largest palm oil producers, the demand for oleochemicals will be a key driver supporting the Malaysian palm oil industry. Palm oil is used in millions of products, from foods to soaps, personal care products cosmetics, and biodiesel feedstock. Currently, palm oil related exports are still highly dependent on the upstream segments such as crude palm oil (CPO), with a total contribution to the overall industry of 81.4%. In comparison, that downstream contribution is still low at about 18.6%. It is thus important to expand the production and export of high-value-added palm oil downstream products, including oleochemicals products. Therefore, this study aims to assess Malaysia's relative competitiveness in oleochemical products as compared to the main oil and fat producing countries - namely Indonesia, China, the European Union (EU) member states, the United States and Argentina. We examine the trade competitiveness by using the Revealed Trade Advantage (RTA) developed by Vollrath (1991) and utilizing yearly data spanning from 1999 until 2019. We also analyze the duration of comparative advantage using Kaplan-Meier Analysis. The results indicate that Malaysia has higher and more stable trade advantages relative to other main producers of oleochemical products.
  5. Othman NH, Othman N, Juhdi NH
    Front Psychol, 2022;13:738729.
    PMID: 35242071 DOI: 10.3389/fpsyg.2022.738729
    This study investigates the moderating effect of students' programs on entrepreneurship education aimed at pre-start-up and its effect on the students' behavior. This study also attempts the level of entrepreneurship education and pre-start-up behavior among students. A survey was carried out among 441 final year students, including 214 students from business programs, and 227 students from non-business programs. Data were analyzed using IBM SPSS 22 and SmartPLS 3.3.0, to perform descriptive and multi-group analysis (MGA), including assessment of measurement invariance of the composite model (MICOM). The results reveal that all direct relationships were supported. It was also found that student programs do have a moderating effect on the relationship between entrepreneurship education and pre-start-up behavior. Furthermore, the results discovered that risk control is a crucial component of entrepreneurship education and should be highlighted in the curriculum. This study contributes to the literature by considering student programs as a moderator, a comparatively new factor in the pre-start-up behavior among university students at the tertiary level. Therefore, entrepreneurship education must be properly designed, and the co-curriculum must be properly organized, so that entrepreneurship will be the preferred career choice in the future.
  6. Othman N, Kamarudin SK
    ScientificWorldJournal, 2014;2014:768604.
    PMID: 24616642 DOI: 10.1155/2014/768604
    Many problems associated with the mixing process remain unsolved and result in poor mixing performance. The residence time distribution (RTD) and the mixing time are the most important parameters that determine the homogenisation that is achieved in the mixing vessel and are discussed in detail in this paper. In addition, this paper reviews the current problems associated with conventional tracers, mathematical models, and computational fluid dynamics simulations involved in radiotracer experiments and hybrid of radiotracer.
  7. Abedini A, Daud AR, Abdul Hamid MA, Kamil Othman N
    PLoS One, 2014;9(3):e90055.
    PMID: 24608715 DOI: 10.1371/journal.pone.0090055
    Colloidal Fe3O4 nanoparticles were synthesized using a gamma-radiolysis method in an aqueous solution containing iron chloride in presence of polyvinyl alcohol and isopropanol as colloidal stabilizer and hydroxyl radical scavenger, respectively. Gamma irradiation was carried out in a 60Co gamma source chamber at different absorbed doses. Increasing the radiation dose above a certain critical dose (100 kGy) leads to particle agglomeration enhancement, and this can influence the structure and crystallinity, and consequently the magnetic properties of the resultant particles. The optimal condition for formation of Fe3O4 nanoparticles with a uniform and narrow size distribution occurred at a dose of 100 kGy, as confirmed by X-ray diffractometry and transmission electron microscopy. A vibrating sample magnetometry study showed that, when radiation dose increased, the saturation and remanence magnetization decreased, whereas the coercivity and the remanence ratio increased. This magnetic behavior results from variations in crystallinity, surface effects, and particle size effects, which are all dependent on the radiation dose. In addition, Fourier transform infrared spectroscopy was performed to investigate the nature of the bonds formed between the polymer chains and the metal surface at different radiation doses.
  8. Lai MY, Rafieqin N, Lee PYL, Amir Rawa MS, Dzul S, Yahaya N, et al.
    Trop Biomed, 2021 Sep 01;38(3):248-253.
    PMID: 34362867 DOI: 10.47665/tb.38.3.065
    Through the regional control programme, Malaysia has been successfully reducing the incidence of Plasmodium falciparum and Plasmodium vivax infections. However, the incidence of zoonotic malaria Plasmodium knowlesi infection is increasing and now has been the major cause of malaria in Malaysia especially Malaysian Borneo. The emergence of knowlesi infection has threatened the malaria elimination programme which the government aims to reduce the overall malaria infections by 2020. Unlike other benign human Plasmodium spp., P. knowlesi can cause fatal infections. The aim of this study was to determine the incidence and distribution of five human malaria parasites including P. knowlesi in Peninsular Malaysia and Malaysian Borneo. A total of 112 blood samples were collected from seven states and district hospitals in Peninsular Malaysia and Malaysian Borneo from year 2015 to 2016. The samples were examined by microscopy and further confirmed by nested PCR assay targeting 18S rRNA gene of Plasmodium spp. Following the nested PCR assays, a total of 54 (48.2%) samples were positive for P. knowlesi infections, 12 (10.7%) cases were positive for P. vivax infections, followed by 7 (6.3%) cases of P. falciparum and 4 (3.5%) cases of P. malariae. There were 3 cases (2.7%) of mixed infections (P. knowlesi/P. vivax). However, no cases were identified as P. ovale. A total of 32 (28.6%) cases were found as negative infections. LoopMediated Isothermal Amplification Assay (LAMP) was performed to confirm inconclusive results produced by microscopy and nested PCR. P. knowlesi showed the highest prevalence in Sarawak (n= 30), Sabah (n=13), Pulau Pinang (n=5) and Pahang (n=6). PCR and LAMP was not able to detect a large number of microscopy positive samples due to DNA degradation during storage and shipping. Among all the states involved in this study, the highest prevalence of P. knowlesi infection was found in Sabah and Sarawak.
  9. Cools P, van Lieshout L, Koelewijn R, Addiss D, Ajjampur SSR, Ayana M, et al.
    PLoS Negl Trop Dis, 2020 06;14(6):e0008231.
    PMID: 32544158 DOI: 10.1371/journal.pntd.0008231
    BACKGROUND: Nucleic acid amplification tests (NAATs) are increasingly being used as diagnostic tools for soil-transmitted helminths (STHs; Ascaris lumbricoides, Trichuris trichiura, Necator americanus, Ancylostoma duodenale and A. ceylanicum), Strongyloides stercoralis and Schistosoma in human stool. Currently, there is a large diversity of NAATs being applied, but an external quality assessment scheme (EQAS) for these diagnostics is lacking. An EQAS involves a blinded process where test results reported by a laboratory are compared to those reported by reference or expert laboratories, allowing for an objective assessment of the diagnostic performance of a laboratory. In the current study, we piloted an international EQAS for these helminths (i) to investigate the feasibility of designing and delivering an EQAS; (ii) to assess the diagnostic performance of laboratories; and (iii) to gain insights into the different NAAT protocols used.

    METHODS AND PRINCIPAL FINDINGS: A panel of twelve stool samples and eight DNA samples was validated by six expert laboratories for the presence of six helminths (Ascaris, Trichuris, N. americanus, Ancylostoma, Strongyloides and Schistosoma). Subsequently this panel was sent to 15 globally dispersed laboratories. We found a high degree of diversity among the different DNA extraction and NAAT protocols. Although most laboratories performed well, we could clearly identify the laboratories that were poorly performing.

    CONCLUSIONS/SIGNIFICANCE: We showed the technical feasibility of an international EQAS for the NAAT of STHs, Strongyloides and Schistosoma. In addition, we documented that there are clear benefits for participating laboratories, as they can confirm and/or improve the diagnostic performance of their NAATs. Further research should aim to identify factors that explain poor performance of NAATs.

  10. Wong WK, Foo PC, Olivos-Garcia A, Noordin R, Mohamed Z, Othman N, et al.
    Acta Trop, 2017 Aug;172:208-212.
    PMID: 28506795 DOI: 10.1016/j.actatropica.2017.05.017
    Crude soluble antigen (CSA) produced from Entamoeba histolytica trophozoite is conventionally used for serodiagnosis of invasive amoebiasis. However, high background seropositivities by CSA-assay in endemic areas complicate the interpretation of positive result in clinical settings. Instead, incorporating a second assay which indicates active or recent infection into the routine amoebic serology could possibly complement the limitations of CSA-assay. Hence, the present study aimed to evaluate the diagnostic efficacies of indirect ELISAs using CSA and excretory-secretory antigen (ESA) for serodiagnosis of amoebic liver abscess (ALA). Reference standard for diagnosis of ALA at Hospital Universiti Sains Malaysia is based on clinical presentation, radiological imaging and positive indirect haemagglutination assay (titer ≥256). Five groups of human serum samples collected from the hospital included Group I - ALA diagnosed by the reference standard and pus aspirate analysis using real-time PCR (n=10), Group II - ALA diagnosed by the reference standard only (n=41), Group III - healthy control (n=45), Group IV - other diseases control (n=51) and Group V - other infectious diseases control (n=31). For serodiagnosis of ALA serum samples (Group I and II), CSA-ELISA showed sensitivities of 100% for both groups, while ESA-ELISA showed sensitivities of 100% and 88%, respectively. For serodiagnosis of non-ALA serum samples (Group III, IV and V), CSA-ELISA showed specificities of 91%, 75% and 100%, respectively; while ESA-ELISA showed specificities of 96%, 98% and 100%, respectively. Indirect ELISAs using CSA and ESA have shown distinct strength for serodiagnosis of ALA, in terms of sensitivity and specificity, respectively. In conclusion, parallel analysis by both assays improved the overall efficacies of amoebic serology as compared to either single assay.
  11. Othman NA, Sockalingam SN, Mahyuddin A
    Haemophilia, 2015 Sep;21(5):605-11.
    PMID: 25757137 DOI: 10.1111/hae.12657
    This case-controlled study aimed to evaluate the existing oral health status in children and adolescents with haemophilia. A total of 50 haemophilia patients and 50 matched controls aged seven to 16 years were recruited into the study. Clinical examination was carried out to determine dental caries experience, oral hygiene status and gingival condition in these two groups. Information regarding previous dental history, oral hygiene practices and dietary habits were also obtained. No significant difference was found in mean caries experience in primary and secondary dentitions (P = 0.86 and 0.32) and in Simplified Oral Hygiene Index (OHI-S, P = 0.20) between both groups. However, a significantly higher proportion of haemophilia patients (24%) had better oral hygiene status as compared to the controls (2%, P = 0.004). Furthermore, there was a significant difference in Modified Gingival Index (MGI, P = 0.02) between the two groups with the study group having less gingival inflammation. A total of 88% (n = 44) of the haemophilia patients were registered and received dental treatment in specialist dental clinics. More than half (56%, n = 28) had frequent dental visits and only one-third of the haemophilia patients had history of hospitalization due to oral problems. There was no significant difference in oral hygiene practices and dietary habits between both groups. In general, haemophilia children and adolescents in this study had similar caries experience, a significantly better oral hygiene status and gingival health as compared to healthy controls. The main reason for this is the multidisciplinary approach implemented by medical health-care professionals as primary care provider and the dental team.
  12. Wahab MSA, Zaini MH, Ali AA, Sahudin S, Mehat MZ, Hamid HA, et al.
    BMC Complement Med Ther, 2021 Apr 01;21(1):110.
    PMID: 33794868 DOI: 10.1186/s12906-021-03287-1
    BACKGROUND: The use of herbal and dietary supplement (HDS) in health and disease management has gained global attention. HDS are generally accepted by the public and are associated with positive health behaviours. However, several reports have been documented with regards to their potential adverse effects and interaction with conventional medicines. Limited data is currently available on the use of HDS among elderly population in Malaysia. This present study aims to investigate the prevalence of and pattern of HDS use among a sample of community-dwelling elderly in a suburban town in Malaysia.

    METHODS: A cross-sectional survey was conducted between March and May 2019 among the elderly aged ≥60 years old. The participants with the following criteria were included in the study: aged ≥60 years, residing in Puncak Alam and able to understand Malay or English language. Data were collected using a pre-validated questionnaire. All statistical analysis was conducted using IBM SPSS ver. 23.

    RESULTS: Overall, 336 out of 400 elderly responded to the survey, achieving a response rate of 84%. This study observed that almost 50% of the respondents were using at least one type of HDS in the past one month of the survey. Among HDS non-users, most of them preferred to use modern medicines (62.6%, 114/182). Among the HDS users, 75.3% (116/154) were using at least one type of modern medicine (prescription or over-the-counter medicine). Multivariate analysis showed that having good to excellent perceived health (adjusted OR = 2.666, 95% CI = 1.592-4.464), having felt sick at least once in the past one month (adjusted OR = 2.500, 95% CI = 1.426-4.383), and lower body mass index (adjusted OR = 0.937, 95% CI = 0.887-0.990) were associated with HDS use. It was noted that only a small percentage of HDS users (16.2%, 25/154) had informed healthcare providers on their HDS use.

    CONCLUSION: The use of HDS is common among the elderly sampled. Hence, healthcare providers should be more vigilant in seeking information of HDS use for disease management in their elderly patients. Campaigns that provide accurate information regarding the appropriate use of HDS among the elderly are pertinent to prevent misinformation of the products.

  13. Wellson, R., Othman, N., Matias-Peralta, H.M.
    MyJurnal
    Algae biodiesel is undeniably very promising as an energy substitute for fossil fuel. It mass cultivation though requires huge capital investment. The aim of this study was to find a simple, inexpensive and tolerable media for algae growth. The optimal growth conditions for algae growth were studied. Botryococcus sp. was isolated from Sembrong Dam in Johor, Malaysia. In this study, two media were used, namely bold’s basal medium (BBM) and synthetic media from nitrogen and phosphorus compound. The synthetic media consisted of ammonium chloride and monopotassium phosphate that were blended together and modified into desired ratios. The N: P ratio of 1.5:1 yielded the highest chlorophyll-a concentration and the optimal growth conditions of algae for both media were at 6000 Lux, pH 7 and 30 rpm. The BMM had the highest algae growth, 3.25 x 107cell/ml while the synthetic media yielded a maximum cell concentration of up to 1.025 x 107 cell/ml which is 68.5% lower compared with BBM. The findings of this study point to the importance of large scale production of algae useful for industrial production of biodiesel.
  14. Othman N, Masarudin MJ, Kuen CY, Dasuan NA, Abdullah LC, Md Jamil SNA
    Nanomaterials (Basel), 2018 Nov 07;8(11).
    PMID: 30405074 DOI: 10.3390/nano8110920
    The combination of compounds with different classes (hydrophobic and hydrophilic characters) in single chitosan carrier is a challenge due to the hydrophilicity of chitosan. Utilization of l-ascorbic acid (LAA) and thymoquinone (TQ) compounds as effective antioxidants is marred by poor bioavailability and uptake. Nanoparticles (NPs) solved the problem by functioning as a carrier for them because they have high surface areas for more efficient delivery and uptake by cells. This research, therefore, synthesized chitosan NPs (CNPs) containing LAA and TQ, CNP-LAA-TQ via ionic gelation routes as the preparation is non-toxic. They were characterized using electron microscopy, zetasizer, UV⁻VIS spectrophotometry, and infrared spectroscopy. The optimum CNP-LAA-TQ size produced was 141.5 ± 7.8 nm, with a polydispersity index (PDI) of 0.207 ± 0.013. The encapsulation efficiency of CNP-LAA-TQ was 22.8 ± 3.2% for LAA and 35.6 ± 3.6% for TQ. Combined hydrophilic LAA and hydrophobic TQ proved that a myriad of highly efficacious compounds with poor systemic uptake could be encapsulated together in NP systems to increase their pharmaceutical efficiency, indirectly contributing to the advancement of medical and pharmaceutical sectors.
  15. Mohd-Radzi NHS, Karuppannan KV, Abdullah-Fauzi NAF, Mohd-Ridwan AR, Othman N, Muhammad Abu Bakar AL, et al.
    Biodivers Data J, 2022;10:e89752.
    PMID: 36761586 DOI: 10.3897/BDJ.10.e89752
    Human-elephant conflict (HEC) contributes to the increasing death of Asian elephants due to road accidents, retaliatory killings and fatal infections from being trapped in snares. Understanding the diet of elephants throughout Peninsular Malaysia remains crucial to improve their habitat quality and reduce scenarios of HEC. DNA metabarcoding allows investigating the diet of animals without direct observation, especially in risky conflict areas. The aim of this study was to determine: i) the diet of wild Asian elephants from HEC areas in Peninsular Malaysia using DNA metabarcoding and ii) the influence of distinct environmental parameters at HEC locations on their feeding patterns. DNA was extracted from 39 faecal samples and pooled into 12 groups representing the different sample locations: Kuala Koh, Kenyir, Ulu Muda, Sira Batu, Kupang-Grik, Bumbun Tahan, Belum-Temengor, Grik, Kampung Pagi, Kampung Kuala Balah, Aring 10 and the National Elephant Conservation Centre, which served as a positive control for this study. DNA amplification and sequencing targeted the ribulose-bisphosphate carboxylase gene using the next-generation sequencing Illumina iSeq100 platform. Overall, we identified 35 orders, 88 families, 196 genera and 237 species of plants in the diet of the Asian elephants at HEC hotspots. Ficus (Moraceae), Curcuma (Zingiberaceae), Phoenix (Arecaceae), Maackia (Fabaceae), Garcinia (Clusiaceae) and Dichapetalum (Dichapetalaceae) were the highly abundant dietary plants. The plants successfully identified in this study could be used by the Department of Wildlife and National Parks (PERHILITAN) to create buffer zones by planting the recommended dietary plants around HEC locations and trails of elephants within Central Forest Spine (CFS) landscape.
  16. Mohd-Yusof NS, Abdul-Latiff MAB, Mohd-Ridwan AR, Badrulisham AS, Othman N, Yaakop S, et al.
    Biodivers Data J, 2022;10:e69631.
    PMID: 36761502 DOI: 10.3897/BDJ.10.e69631
    Flying fox (Pteropushypomelanus) belongs to the frugivorous bats, which play a crucial role in maintaining proper functioning of an ecosystem and conservation of the environment. Bats are well-known carriers of pathogenic viruses, such as BatCov RaTG13 from the coronavirus family that share 90.55% with SARS-CoV-2, the pathogen causing recent global pandemic coronavirus disease 19 (COVID-19). However, bats' possible role as a carrier of pathogenic bacteria is less explored. Here, using metabarcoding analysis through high-throughput sequencing, we explored the gut microbiome composition of different island populations on the east and west coasts of Peninsula Malaysia. The 16S rRNA gene in samples from Redang Island, Langkawi Island, Pangkor Island and Tinggi Island was amplified. Bacterial community composition and structure were analysed with α and β diversity metrics. A total of 25,658 operational taxonomic units at 97% similarity were assigned to eight phyla, 44 families, 61 genera and 94 species of microbes. The Proteobacteria was the dominant phylum in all populations. Meanwhile, the genera Enterobacter, Pseudomonas and Klebsiella, isolated in this study, were previously found in the rectum of other fruit bats. Our analyses suggest that Redang Island and Langkawi Island have high bacteria diversity. Thus, we found geographic locality is a strong predictor of microbial community composition and observed a positive correlation between ecological features and bacterial richness.
  17. Abdullah-Fauzi NAF, Karuppannan KV, Mohd-Radzi NHS, Gani M, Mohd-Ridwan AR, Othman N, et al.
    Zool Stud, 2022;61:e60.
    PMID: 37007822 DOI: 10.6620/ZS.2022.61-60
    The world's largest terrestrial mammal, Asian elephants, are known to have enormous feeding needs. Several factors such as season, sex, age, and daily activities influence the amount of food required by an individual. Generally, captive elephants have a limited choice of food on a daily basis compared with that of elephants in the wild. Elephants in captivity are fed according to a prepared feeding schedule, whereas wild elephants are free to choose the type of plants that they consume in their natural habitat. In the past, ecological observations have been widely used to determine the diet of wild elephants. However, the molecular approach has never been carried out. In the present study, we aimed to; 1) identify the plant diet of wild Asian elephants in Taman Negara National Park (TNNP) according to their sex and age using high-throughput DNA metabarcoding; and 2) determine the dietary formulation of captive elephants based on the generated plant metabarcoding database. DNA was extracted from 24 individual fecal samples collected using noninvasive sampling techniques from TNNP and the National Elephant Conservation Centre (NECC) Kuala Gandah. Seven pooled samples from male adult, female adult, male subadult, female subadult, male juvenile, female juvenile, and captive elephants were amplified and sequenced targeting the trnL region (50-150 base pairs). The CLC Genomic Workbench and PAST 4.02 software were used for data analysis. In total, 24 orders, 41 families, 233 genera, and 306 species of plants were successfully detected in the diet of the Asian elephants. The most abundant plant genera consumed were Sporobolus (21.88%), Musa (21.48%), and Ficus (10.80%). Plant variation was lower in samples from male elephants than in those from female elephants. The plant species identified were correlated with the nutrient benefits required by elephants. Adults and subadults consumed more plant species than were consumed by juvenile elephants. However, there was no significant difference between ages and sexes. The findings of this study can be used as guidance by the Department of Wildlife and National Parks for the management of captive elephants, especially in NECC Kuala Gandah.
  18. Othman N, Kamarudin SK, Takriff MS, Rosli MI, Engku Chik EM, Meor Adnan MA
    ScientificWorldJournal, 2014;2014:619474.
    PMID: 25170524 DOI: 10.1155/2014/619474
    This paper presents the preliminary steps required for conducting experiments to obtain the optimal operating conditions of a hybrid impeller mixer and to determine the residence time distribution (RTD) using computational fluid dynamics (CFD). In this paper, impeller speed and clearance parameters are examined. The hybrid impeller mixer consists of a single Rushton turbine mounted above a single pitched blade turbine (PBT). Four impeller speeds, 50, 100, 150, and 200 rpm, and four impeller clearances, 25, 50, 75, and 100 mm, were the operation variables used in this study. CFD was utilized to initially screen the parameter ranges to reduce the number of actual experiments needed. Afterward, the residence time distribution (RTD) was determined using the respective parameters. Finally, the Fluent-predicted RTD and the experimentally measured RTD were compared. The CFD investigations revealed that an impeller speed of 50 rpm and an impeller clearance of 25 mm were not viable for experimental investigations and were thus eliminated from further analyses. The determination of RTD using a k-ε turbulence model was performed using CFD techniques. The multiple reference frame (MRF) was implemented and a steady state was initially achieved followed by a transient condition for RTD determination.
  19. Othman N, Zailani SN, Mili N
    J Hazard Mater, 2011 Dec 30;198:103-12.
    PMID: 22023906 DOI: 10.1016/j.jhazmat.2011.10.014
    The extraction of Red 3BS reactive dye from aqueous solution was studied using emulsion liquid membrane (ELM). ELM is one of the processes that have very high potential in treating industrial wastewater consisting of dyes. In this research, Red 3BS reactive dye was extracted from simulated wastewater using tridodecylamine (TDA) as the carrier agent, salicyclic acid (SA) to protonate TDA, sodium chloride as the stripping agent, kerosene as the diluent and SPAN 80 as emulsifier. Experimental parameters investigated were salicyclic acid concentration, extraction time, SPAN 80 concentration, sodium chloride concentration, TDA concentration, agitation speed, homogenizer speed, emulsifying time and treat ratio. The results show almost 100% of Red 3BS was removed and stripped in the receiving phase at the optimum condition in this ELM system. High voltage coalesce was applied to break the emulsion hence, enables recovery of Red 3BS in the receiving phase.
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