Displaying publications 121 - 140 of 418 in total

Abstract:
Sort:
  1. Pezhman Ghadimi, Noordin Mohd Yusof, Muhamad Zameri Mat Saman, Mahmood Asadi
    MyJurnal
    Academic and corporate interest in sustainable product and process development has risen considerably
    in recent years. This can be seen by the number of papers published and in particular by special issued of journals. This paper reports the results of a review of published peer-reviewed literature from 1987 to 2012 to provide an up-to-date picture of sustainability and sustainable assessment. A structured methodology is followed to narrow down the search from around 3500 papers to 111. A variety of different sustainability assessment methodologies are reviewed in two classified research areas: product sustainability assessment and process sustainability assessment. In presenting a detailed taxonomy of product and process sustainability assessment methods, the paper also outlines the advantages and weaknesses of the sustainability assessment methods. The review sheds light on the weak points of current research in this area. The paper also highlights several key issues which have to be taken into account in attempting to develop a product or process sustainability assessment research paradigm for future applications in manufacturing systems.
  2. Arbaiah, O., Badrul, H.A.S., Marzukhi, M.I., Mohd Yusof, Badaruddin, M., Mohd Adam
    MyJurnal
    Outbreak management in disaster has to be planned and implemented prior to, during and after the disaster is over. The risk of outbreaks following disaster is related to the size, health status and living conditions of the displaced population. The risk is increased due standing water in floods for vector borne diseases, overcrowding, inadequate water and sanitation and poor access to health care. The 2006-2007 flood in Johore resulted in 2 episodes of food poisoning and an outbreak of coxsackie A24 acute haemorrhagic conjunctivitis. Only 19,667 (12.5%) of the 157,018 displaced persons suffered from communicable diseases which comprised of acute respiratory disease 7361(28%), skin infection 4241(19%), acute gastroenteritis 1872(8%) and conjunctivitis 589 (2%). The routine disease surveillance and environmental control were enhanced to cover the relief centers and flood areas. Risk assessment of communicable disease carried out resulted in prompt control measures and good coverage of preventive activities. In conclusion the Johore State Health Department has successfully manage the outbreaks during the major flood.
  3. Noraishah Othmanl, Nor Pa' iza M. Hasani, Juhari Mohd Yusof, Roslan Yahya, Mohd Amirul Syafiq
    MyJurnal
    Flow measurement is a critical element for liquid resources monitoring for various applications in many industrial systems. The purposes of the study are to determine the flow rate of liquid system in flow rig using radiotracer techniques and to compare the result with that obtained by the conventional flow meters. The flow rig consists of 58.7m long and 20cm diameter pipeline that can accommodate about 0.296m3 of liquid. Tap water was used as liquid flow in pipeline and conventional flow meters were also installed at the flow rig. Radiotracer was injected as a sharp pulse into the inlet p.peline. The pulse was monitored at the inlet and various points along the outlet pipeline using collimated scintillation detector. The peak to peak and total count methods were applied for radiotracer techniques and showed the comparable results with conventional flow meter.
  4. Salmah Moosa, Seri Chempaka Mohd. Yusof, Ruzalina Bahrin, Maizatul Akmam Md. Nasir
    MyJurnal
    Radiation processing of food materials by gamma-radiation is a well-established method for
    microbial decontamination and insect disinfestation. Irradiation of spices at doses ranging from
    10 to 30 kGy has been reported to result in complete elimination of microorganisms with
    negligible changes in the flavour quality. The effect of gamma-radiation on microflora and
    vanillin content of cured vanilla beans in the dose range of 5 - 50 kGy has been investigated, but
    its effect on other major aroma compounds and vanillin glucoside (vanillin aroma precursor)
    remaining after curing have not been studied so far. Vanillin (4-hydroxy-3-methoxybenzaldehyde)
    is one such compound used as a flavouring agent and as a dietary component. It is the major
    component of natural vanilla, which is one of the most widely used and important flavouring
    materials throughout the world. Vanillin is an antioxidant capable of protecting membrane
    against lipid peroxidation and DNA against strand breaks induced by reactive oxygen species.
    The present work was aimed to study the effect of gamma-radiation processing on the major
    aroma compounds of cured vanilla beans and also to investigate possible enhancement in vanillin
    content by the radiolytic breakdown of vanillin glucoside present already. Cured vanilla beans
    were irradiated (5, 10, 15, 20 and 30 kGy) and the vanillin content of control and irradiated
    samples were analysed, respectively for possible enhancement of vanillin content by radiolysis of
    vanillin glucoside. Radiolytic breakdown of glycosidic precursors of aroma constituents and
    consequent release of free aroma was shown to result in the enhancement of aroma quality of
    these products. Since a considerable amount of vanillin exists as its glycosidic precursor in cured
    vanilla pods, a possible enhancement in yield of vanillin by radiation processing is thus expected.
    Hence the highly stable oxygen–carbon linkage between vanillin and glucose limits the possible
    enhancement of aroma quality of irradiated beans.
  5. Norimah A.Karim, Nik Shanita Safii, Safiah Mohd Yusof, Norazliana Mohd Noor, Zawiah Ahmad, Tee, E Siong
    MyJurnal
    This paper reports the nutrition knowledge of Malaysian elderly, as part of a nationwide study to evaluate the status of nutrition knowledge, attitude and practice (KAP) of food and nutrition among various communities in Malaysia. A total of 906 elderly, age ranging between 60 to 96 years old, with mean age 67.4 ± 6.7 years representing all states in Malaysia participated in the study. An interview administered questionnaire was used to assess the nutrition knowledge and to collect demographic data of the elderly. Subjects were in the 60-65 years (51%) and more than 65 years (49%) age category. There were 46% Malays, 32% Chinese, 6% Indians while the remaining 16% comprised of other minority groups in Malaysia such as Iban, Kadazan, Melanau, Orang Asli and others. More than half of the elderly (54%) had no formal education, 36% completed primary schooling and only 9% finished secondary education. Overall 73% elderly were categorized as having poor nutrition knowledge, 18% moderate and only 9% good. The minority groups had the highest percentage of poor nutrition knowledge (91%) while the Chinese had the highest percentage of good nutrition knowledge (11%). More female (78%) than male (67%) had poor nutrition knowledge, in contrast to more male (10%) than female (8%) with good nutrition knowledge. Chi square test showed that there was a significant correlation between educational status and nutrition knowledge. This was reflected in the results which showed that 81% elderly with no formal education were categorized in the poor nutrition knowledge group. Majority of the elderly did not know about foods to be consumed most (88%), or to be eaten least (87%). Only a quarter to a third of the elderly responded correctly to questions on nutrient function and content. The question on foods with high salt was well responded by the elderly (65%). It is quite discouraging to show that a majority of Malaysian elderly had poor nutrition knowledge. This study indicated that appropriate nutrition education interventions need to be implemented to improve the shortcomings of nutrition knowledge among the Malaysian elderly.
  6. Barakatun Nisak Mohd Yusof, Ruzita Abd. Talib, Norimah A. Karim, Nor Azmi Kamarudin, Fatimah Arshad
    MyJurnal
    White and whole meal breads have been classified as high glycemic index (GI) foods which in turn produce the greatest rise in blood glucose. One of the commercial bread products in Malaysia known as Brown breads (BB) has been recently marketed as a healthy choice for diabetics due to its low GI value. This study was conducted to examine the effect of BB when eaten with different fillings on blood glucose response among healthy individuals and to describe the influences of these fillings in reducing blood glucose response. Five test meals using BB (BB eaten with baked beans, BB eaten with vegetable, BB eaten with apple, BB eaten with roast chicken and BB eaten with seaweeds) had been prepared for this study. Postprandial blood glucose response was determined for each test meal and reference food (glucose) that contained 50 g carbohydrate respectively. A total of 21 healthy subjects were recruited by advertisement to participate. Only 20 subjects (15 males, 5 females, Mean + SD Age : 24.4 + 3.7 years; BMI 23.4 + 3.0 kgm-2) completed this study. After an overnight fast, subjects consumed BB eaten with fillings according to the assigned group given and three repeated tests of reference food (glucose). Fasting capillary blood glucose samples were taken at time 0 and at 15, 30, 45, 60, 90 and 120 min respectively after the meal began. The blood glucose response was obtained by calculating the incremental area under the curve (AUC). Blood glucose response after consuming reference food (251.8 + 12.1 mmol.min/L) was significantly higher than all the test meals (p < 0.05). Among the test meals, BB eaten with baked beans produced the highest rise in blood glucose (97.0 + 16.9 mmol.min/L) whereas BB eaten with seaweeds demonstrated the lowest response in blood glucose (33.3 + 6.5 mmol.min/L) and the difference was statistically significant (p < 0.05). The postprandial blood glucose response after ingestion of BB when eaten with vegetable was 73.3 + 19.1 mmol.min/L followed by BB eaten with apple (58.9 + 12.2 mmol.min/L) and BB eaten with roast chicken (56.5 + 10.1 mmol.min/L). Generally, BB when eaten with fillings produced a slow rise in blood glucose response than the reference food. Combining this BB with fillings had the effect of reducing the postprandial blood glucose further.
  7. Mohd Ihsani Mahmood, Idayu Badilla Idris, Rosnah Sutan, Hasanain Faisal Ghazi, Rozita Hod, Hanizah Mohd. Yusof
    MyJurnal
    Men’s health remain unclear term for majority of general population as well as physician worlwide. Nowadays there is an increase interest in addressing men’s requirement in health care as a separate branch. When discussing about men’s health, it is fair to say that even a man himself does not know much about men’s health. Most of them think that men’s health is just a discussion on sex. This thought is not entirely right. The scope of men’s health is actually larger than the male sex organ itself. To define men’s health, we have to look at man holistically.
  8. Norfariha Che Mohamed, Khoo Kok Siong, Hapizah Nawawi, Mohd Yusmiaidil Putera Mohd Yusof
    MyJurnal
    The aims of this study are to estimate the equivalent dose to the skin, eyes and thyroid in intra- and extra-oral imaging examination and to compare the dose-area product (DAP) derived from the calculation method with Diagnostic Reference Levels (DRL) that has been provided by the Malaysian Ministry of Health (MOH). Dose equivalent is measured by placing Thermoluminescence Dosimeter (TLD-100H) in the anthropomorphic RANDO phantom. Exposure is performed using intra-oral X-ray machine ActeonSatelec X-Mind® and extra-oral X-ray machine InstrumentariumOP300®, and the value is compared to the equivalent dose of the International Commission on Radiological Protection (ICRP) dose limit. DAP value for both examinations was obtained by using formula and comparing them with the DRL from MOH. The average dose equivalent of intra- and extra-oral radiographic examination is lower than the ICRP dose limit. The doses derived from both examinations did not exceed the prescribed levels when compared with DRL. The doses calculated for intra-oral examination of molar maxillary, molar mandibular and interproximal (bitewing) was 0.880 mGy while periapical examination of the anterior maxillary and mandibular was 0.688 mGy and occlusal examination was 1.100 mGy. For the panoramic examination the dose was 0.011 mGy.m2 while lateral cephalometric examination was 0.0054 mGy.m2. The doses obtained from this study were within the dose limit and predetermined level. This shows that a patient receives the minimum dose for both dental radiographic examinations with the optimum level of safety which meets the ALARA concept.
  9. Mohd Yusof Baharuddin, Ng, Woon Shih, Chan, Ting Kai, Jia, Chengli, Fazri Wasli
    MyJurnal
    Journal of Sports Science and Physical Education 7(1): Received: 10 January 2018, Accepted: 15 February 2018 – The purpose of this study was to investigate the muscle activation of the quadriceps and the hamstrings muscle during forward lunge. The study was performed using wireless electromyography (EMG) sensor placed on the interest muscles. The parameter used was the root mean square value during forward lunges activity. The results demonstrated that the rectus femoris muscle was more dominant than the biceps femoris muscle during the initial movement when the knee was in flexion direction and the feet was in dorsiflexion. A linear relationship was initiated between the raw data and RMS value of the EMG signal of the rectus femoris and biceps femoris. The motions elicit eccentric activations of the hamstring muscle groups during lunge activity.
  10. Puteri Nor Khatijah Abd Hamid, Abdul Aziz Tajuddin, Mohd Fahmi Mohd Yusof, Rokiah Hashim
    MyJurnal
    The particleboards were fabricated using Rhizophora spp. wood particles with particles size less than 74 μm. The corn starch was used as a bio-adhesive in the fabrication of Rhizophora spp. particleboards. The corn starch bonded particleboards were fabricated at 5% and 10% corn starch based on dry mass of Rhizophora spp. wood particles. The measurement of mass attenuation coefficients of the particleboards were made at low and intermediate photon energies. The mass attenuation coefficient at low photon energy was measured using X-ray fluorescent (XRF) configuration based on attenuation of Kα1 X-ray energies between 16.59 and 25.26 keV given by niobium, molybdenum, palladium and tin metal plates. The calculated mass attenuation coefficients of samples were compared to the theoretical values mass attenuation coefficients of water calculated using the photon cross-section database (XCOM). The results showed that mass attenuation coefficients of 10% corn starch added Rhizophora spp. particleboards were in good agreement of water within 7.96 and 4.94% for 5% and 10% corn starch Rhizophora spp. Particleboards, respectively compared to 14.57 and 16.16% in binderless Rhizophora spp. particleboards and raw Rhizophora spp. wood, respectively.
  11. Mohd Fahmi Mohd Yusof, Nur Amirah Nabila Ramli, Mohd Fahrizuan Md Yusop, Reduan Abdullah
    MyJurnal
    This study evaluates the ImageJ software as dosimetric tools for analyzing the film dosimeter in high energy photons and electrons. The percentage depth dose of photons of 6 and 10 MV and electrons of 6 and 9 MeV were measured using the Gafchromic EBT2 film dosimeter. The films were scanned and analyzed using the Verisoft software and ImageJ. The beam profiles at nominal photon and electron beam parameters were also evaluated using the two methods. The PDD measured in ImageJ at high energy photons were in good agreement within 1% percentage of discrepancy at all depths in comparison to the Verisoft software. The PDD measured in ImageJ at high energy electrons also showed good agreement to Verisoft software within 8% percentage of discrepancy at all depths. The measured flatness of beam profiles at Dmax, R50, R80 and R90 in ImageJ were also in good agreement to Verisoft software with flatness value between 4 and 8%. The results indicated the suitability of ImageJ software as dosimetric tool for analyzing EBT2 film dosimeter at high energy photon and electrons.
  12. Zulkifli Mohd Yusof, Syed Ahmad Ezahar Syed Ambon, Junaidy Mohamad Hashim
    MyJurnal
    Journal of Sports Science and Physical Education 5(1): 49-64, 2016 - The aim of this study is
    to assess health related physical fitness of MSKPPM soccer players (Veteran Category).
    Besides that, this study also aims to see whether there is any differences based on the health
    related components of physical fitness according to age group. The samples of this study were
    40 soccer players who were involved in a selection, aged between 40 to 49 years. Test battery
    used in this study is Prudential FITNESSGRAM® by Cooper Institute for Aerobic Research
    (1992) which includes PACER 20 meter Multistage run, push up, curl up, trunk lift and body
    mass index (BMI). Data analysis showed that there is significant difference on the different
    components of health related physical fitness for the different age groups. Age 40-41, Pacer
    [min: 24.66; SD: 2.88], curl up [min:33.33; SD: 5.20], push up [min: 46.83; SD: 3.65], trunk
    lift [min: 43.16;SD: 13.58] and BMI [min:42.46; SD: 5.99]. Age 42-43, Pacer [min: 24.38; SD:
    2.29], curl up [min:41.08; SD: 9.26], push up [min: 48.41; SD: 6.12], trunk lift [min: 47.16;SD:
    9.35] and BMI [min:42.66; SD: 5.40]. Age 44-45, Pacer [min: 24.36; SD: 2.66], curl up
    [min:39.75; SD: 9.69], push up [min: 48.00; SD: 5.81], trunk lift [min: 45.92;SD: 9.51] and
    BMI [min:41.69; SD: 5.62]. Age 46-47, Pacer [min: 20.65; SD: 3.51], curl up [min: 19.40; SD:
    1.67], push up [min: 44.20; SD: 1.78], trunk lift [min: 30.60;SD: 8.50] and BMI [min: 33.92;
    SD: 4.13]. Age 48-49, Pacer [min: 27.26; SD: 0.55], curl up [min: 17.00; SD: 3.60], push up
    [min: 47.33; SD: 2.88], trunk lift [min: 29.00;SD: 8.18] and BMI [min: 30.23; SD: 3.45]. The
    results of this study can be used by the coaches in Malaysia to ensure that players involved in
    any tournaments has excellent fitness level and to avoid from making aggressive actions which
    may cause tense situation among players. The results of this study is hope to convince all
    players and coaches on the importance of good physical fitness as it will positively affect the level of playing to be more effective and high quality.
  13. Anderios F, Zulaikah Mohamed, Ratnam S, Mohd Yusof Ibrahim, Tajul Ariffin Mohd Awang
    Sains Malaysiana, 2008;37(2).
    The emergence of primate malaria known as Plasmodium knowlesi in humans, which is always misdiagnosed by microscopy as P. malariae, has contribute to the needs of nucleic acid based technology to be applied in detection and differentiation of malaria parasites. The target DNA sequence of the 18SrRNA gene was amplified by a nested PCR assay for detection and identification of Plasmodium species in 31 Giemsa-stained blood smears examined as P. malariae. The assay demonstrated three samples identified as positive to genus-specific primers but negative to all species-specific primers. Three cases of misdiagnosed species were detected. The samples were diagnosed as P. malariae microscopically, but detected as P. falciparum by PCR assay. Twenty five out of 31 samples were detected as P. knowlesi. None of the samples diagnosed microscopically as P. malariae were identified as P. malariae with the nested PCR assay. Over 80.6% of all malaria cases in this study showed naturally acquired P. knowlesi infections.
  14. Hasniyati Muin, Norhidayah Mohd Taufek, Hanan Mohd Yusof, Raji Ameenat Abiodun, Shaharudin Abdul Razak
    Sains Malaysiana, 2015;44:511-516.
    A dietary study was conducted to assess the use of mushroom stalk (MM), Pleurotus sajor caju, an agriculture waste and
    soy bean meal (SBM) as partial and complete replacement of fishmeal (FM) in tilapia fingerling diets. The study was
    conducted for 56 days. The diets were processed into sinking pellets. The experimental diets were formulated to replace
    fish meal protein at 0, 33, 67 and 100% (diet 4, 3, 2 and 1). In this experiment, Nile tilapia fingerlings weighing about
    1.00 g were fed each of four isonitrogenous diet. They were randomly distributed into 12 plastic tanks with each tank
    stocking 20 fish. The experiment was conducted in three replicates for each treatment. All the diets were well accepted
    by the fish. No physical abnormalities were observed in all treatments. Good growth performance was shown in 33%
    replacement (diet 3) of FM diet. However, diet 1 (100% replacement) gave the highest increment in crude protein level
    and the best result of feed conversion ratio (FCR) and protein efficiency ratio (PER). Furthermore, the 100% replacement
    of FM (diet 1) was the best with a production cost of RM2.61/kg.
  15. Nurul-Yuziana Mohd-Yusof, Hoh CC, Adura Mohd-Adnan, Wan KL
    The Asian seabass (Lates calcarifer) is one of the most economically important aquaculture fish species in South East Asia. While the biology of the Asian seabass is widely studied, relatively little information is available at the molecular level. This lack of molecular information represents one obstacle to rapid progress in the study of immune responses particularly under aquaculture conditions. In light of this situation, we have undertaken an expressed sequence tag (EST) project on the Asian seabass spleen, the secondary lymphoid organ, for the identification of immune-related genes. A
    total of 2932 ESTs were generated and grouped into 1063 unique transcripts (UTs), which consisted of 104 consensi and 959 singletons. Of these, 51.3% (545/1063) matched to previously identified genes, while 48.7% (518/1063) showed no match. Of the 545 homologous UTs, 102 (9.6%) can be putatively identified as immune-related genes. The identification of the putative immune-related genes provides a meaningful framework in the effort to comprehend the Asian seabass immune system that may lead to an increase in the understanding of the defense mechanisms of and our abilities to
    manage this fish species.
  16. Mohd Yusof Othman, Ahmad Fudholi, Kamaruzzaman Sopian, Mohd Hafiz Ruslan, Muhammad Yahya
    Sains Malaysiana, 2012;41:245-252.
    Sistem pengering suria untuk pengeringan hasil pertanian dan laut telah direka bentuk, dibina dan diuji dalam suasana cuaca di Malaysia. Sistem pengeringan suria yang dibina, diuji untuk mengeringkan rumpai laut Gracilaria changii. Rumpai laut yang dikeringkan mempunyai kandungan air sekitar 95% asas berat basah untuk menghasilkan produk kering yang mempunyai kandungan air 10%. Proses pengeringannya mengambil masa selama kira-kira 7 jam, pada purata keamatan sinaran suria 593 W/m2 dan kadar aliran udara pengering 0.0613 kg/s. Pemadanan tiga model pengeringan telah dilakukan dengan data uji kaji pengeringan rumpai laut menggunakan sistem pengering suria pada suhu udara purata dalam kebuk 50oC dan purata kelembapan relatif udara 20%. Kejituan padanan model ditentukan berdasarkan nilai R2 yang paling tinggi, juga nilai MBE dan RMSE yang paling rendah. Kajian ini mendapati model pengeringan rumpai laut yang sesuai adalah model pengeringan Page dibandingkan dengan model pengeringan yang lain (model pengeringan Newton dan model Henderson dan Pabis).
  17. Mohd. Yusof Hj. Othman, Faridah Hussain, Kamaruzzman Sopian, Baharuddin Yatim, Hafidz Ruslan
    Sains Malaysiana, 2013;42:1319-1325.
    Three different designs of heat exchanger, V-groove, honeycomb and stainless steel wool had been tested to study their effectiveness in improving the overall performance of a photovoltaic/thermal (PV/T) air base solar collector. Heat exchangers were installed horizontally into the channel located at the back side of the PV module. The system was tested at irradiance of 828 W/m2 with mass flow rate spanning from 0.02 kg/s to 0.13 kg/s. It was observed that at mass flow rate of 0.11 kg/s, the maximum thermal efficiency of the system with V-groove is 71%, stainless steel wool is 86% and honeycomb is 87%. The electrical efficiency of the systems is 7.04%, 6.88% and 7.13%, respectively. The experimental results showed that honeycomb design is the most efficient design as heat exchanger. The design which is simple and compact is suitable for building integration.
  18. Ayub Md Som, Nur Farhana Mohd Yusof, Ali, Sherif Abdulbari, Nurafiqah Zawawi
    MyJurnal
    Failure of pancreas can cause uncontrolled blood glucose levels in the body. This research focuses on type 1 diabetes patients who depend on external insulin injection. The Hovorka model was used as the mathematical model in the development of control algorithm for artificial pancreas. However, the model showed a lack of interaction on selected parameters and variables in its glucose-insulin dynamic system. An improvement on the Hovorka equations was done, but no work was carried out to simulate the proposed equations. The objectives of this study are to simulate the modified Hovorka equations using MATLAB and to compare the simulation results between the reference and modified ones. This study showed better interaction among all variables and parameters on its glucose-insulin dynamic system using the modified equations compared to the original equations. The lower administered amount of insulin, Ut at 16.7mU/min and 20mU/min could regulate the blood glucose level at normoglycemic condition throughout the study.
  19. Aishah Faiqah Mohd Yusof, Prabhakaran P, Nur Diyana Azli, Norrakiah Abdullah Sani, Wan Syaidatul Aqma
    Sains Malaysiana, 2017;46:903-908.
    Pacifier nipples are in permanent contact with saliva and with the oral microflora therefore, act as a favoured site for the growth of biofilms. This research was conducted to identify the bacterial biofilms that has been found on the pacifiers that collected from local child nursery and to analyse the formation of biofilms by Cronobacter sp. during growth in infant formula milk. Pacifiers collected were analysed to obtain colony forming unit (CFU) and isolated bacteria were identified using several biochemical tests according to Bergey's Manual. Biofilm assay of three Cronobacter sp. were conducted using 24 wells microtiter plate and stained with 1% of crystal violet solution at different time interval: 6, 12, 18 and 24 h. The hydrophobicity of the bacterial cell suspension was evaluated using bacterial adhesion to hydrocarbons (BATH) method. Extracellular polymeric substances (EPS) analysis was done to identify percentage of carbohydrate and protein content by using phenol sulphuric acid method and Bradford method, respectively. The results obtained showed that the normal microflora bacteria were the most abundant microorganisms that were found on the pacifier with the main genus isolated was Staphylococcus sp., Enterobacteriaceae sp. and Clostridium sp. Based on biofilm and EPS analysis, Cronobacter sakazakii formed a strong biofilms after 18 h, with carbohydrate was identified as main component of EPS.
  20. Muhammad Jefri Mohd Yusof, Nur Aidasyakirah Mohd Tahir, Fazira Firdaus, Siti Fairus M. Yusoff
    Sains Malaysiana, 2018;47:2055-2061.
    Getah asli cecair (LNR) dihasilkan daripada proses penyahpolimeran getah asli yang menghasilkan rantaian polimer
    lebih pendek dan berat molekular kurang daripada 105
    . Namun, LNR masih mempamerkan tahap degradasi dan ketahanan
    termal yang rendah seperti getah asli, disebabkan oleh kehadiran ikatan karbon ganda dua pada rantaian polimer.
    Dalam kajian ini, penurunan diimida menggunakan pengoksidaan hidrazin hidrat dengan hidrogen peroksida dijalankan
    untuk menghidrogenkan unit tidak tepu LNR. LNR terhidrogen (HLNR) dicirikan menggunakan spektrometer infra-merah
    (FTIR) dan spektrometer resonans magnetik nuklear (NMR). Pengoptimuman parameter tindak balas dilakukan dengan
    memanipulasi parameter masa dan suhu tindak balas berdasarkan kaedah rangsangan permukaan (RSM) dengan
    5-aras-2-faktor reka bentuk komposit putaran tengah (CCRD). Satu model kuadratik yang signifikan telah dihasilkan
    untuk menghubungkan dua parameter tersebut dengan nilai R2 adalah 0.9986, menunjukkan bahawa model yang terhasil
    adalah sangat sepadan dengan data uji kaji. Keputusan kajian menunjukkan bahawa peratus penghidrogenan boleh
    ditingkatkan sehingga 91.2%. Seterusnya, berdasarkan RSM, parameter yang optimum bagi penurunan diimida LNR ini
    didapati pada suhu 55.9o
    C selama 6.7 jam, menghasilkan 80.2% HLNR. Kajian ini telah menunjukkan reka bentuk uji kaji
    secara statistik yang novel bagi menghidrogenkan LNR. Pelbagai variasi peratus penghidrogenan produk HLNR dalam
    kajian ini menyumbang kepada lebih banyak aplikasi produk yang memerlukan peratusan ketepuan unit yang tertentu.
Filters
Contact Us

Please provide feedback to Administrator ([email protected])

External Links