A common practice in psychiatry when treating patients is the concurrent administration of anticholinergics along with antipsychotics, either to prevent or treat extrapyramidal syndrome reactions from occurring. However, most antipsychotics have inherent anticholinergic properties themselves. Therefore, this subtype of these patients have a higher than usual risk of developing anticholinergic side-effects, of which the central nervous manifestations can mimic psychosis, and may cloud judgement on patients’ progress towards their treatment.
MeSH terms: Case Reports; Humans; Malaysia; Psychotic Disorders; Cholinergic Antagonists
Six groups of adult male Sprague Dawley rats, each consisting of six animals were used throughout the experiment. The gastroprotective effects of aqueous plant extract alone, honey alone or honey in combination with ethanolic or aqueous extracts of A. conyzoides and cimetidine were investigated in rats against ethanol-HClinduced gastric ulcer. Efficacy was assessed by determination of ulcer index and inhibition percentage. Oral administration of ethanol-HCl (5 ml kg-1 body weight) to fasted rats produced extensive lesions of gastric mucosa (Group 1). Pre-treatment with honey (2.5 g kg-1 body weight) alone (Group 2), aqueous plant extract alone (10% w/v 5 ml kg-1) (Group 3), or honey in combination with each of alcoholic extract (10% w/w 5 ml kg-1) (Group 4), aqueous extract (10% w/w 5 ml kg-1) (Group 5) or cimetidine (10 mg/ml honey 5 ml kg-1) (Group 6) orally 30 minutes before administration of absolute ethanol-HCl significantly (p < 0.05) protected gastric lesions by 46.74%, 61.50%, 76.68%, 78.39% and 56.55% respectively. Although the mechanism of gastric protection is unknown, honey in combination with each plant extract appears to increase the resistance of gastric mucosal cells to the necrotizing effect of strong irritants in the absolute ethanol-HCl mixture. The results suggest that honey in combination with each plant extract might be beneficial in the treatment of a variety of diseases in which gastric mucosal injury is present. KEYWORDS: Honey, A. conyzoides, cimetidine, rats, ulcer
Six groups of adult male Sprague Dawley rats, each consisting of six animals were used throughout the experiment. The gastroprotective effects of aqueous plant extract alone, honey alone or honey in combination with ethanolic or aqueous extracts of A. conyzoides and cimetidine were investigated in rats against ethanol-HCl induced gastric ulcer. Efficacy was assessed by determination of ulcer index and inhibition percentage. Oral administration of ethanol-HCl (5 ml kg-1 body weight) to fasted rats produced extensive lesions of gastric mucosa (Group 1). Pre-treatment with honey (2.5 g kg-1 body weight) alone (Group 2), aqueous plant extract alone (10% w/v 5 ml kg-1) (Group 3), or honey in combination with each of alcoholic extract (10% w/w 5 ml kg-1) (Group 4), aqueous extract (10% w/w 5 ml kg-1) (Group 5) or cimetidine (10 mg/ml honey 5 ml kg-1) (Group 6) orally 30 minutes before administration of absolute ethanol-HCl significantly (p < 0.05) protected gastric lesions by 46.74%, 61.50%, 76.68%, 78.39% and 56.55% respectively. Although the mechanism of gastric protection is unknown, honey in combination with each plant extract appears to increase the resistance of gastric mucosal cells to the necrotizing effect of strong irritants in the absolute ethanol-HCl mixture. The results suggest that honey in combination with each plant extract might be beneficial in the treatment of a variety of diseases in which gastric mucosal injury is present.
Cardiopulmonary exercise testing is a non-invasive physiological test which incorporates the conventional method of exercise stress test with a more advanced breath-to-breath ventilatory analysis. The physiological parameters obtained from the test help to illustrate the cardiovascular, respiratory and metabolic responses to physical exertion. Individual's functional capacity and aerobic fitness is reflected by the value of maximal oxygen consumption (VO2 max) obtained from the cardiopulmonary exercise test. This non-invasive and sophisticated test is regarded as a valuable assessment tool in research and clinical practice. Cardiopulmonary exercise test has been extensively utilized to define the mechanisms of exercise intolerance in various clinical disorders, to evaluate responses to therapy and indicate disease prognosis. Emerging data obtained from the use of the cardiopulmonary exercise testing in the research field, has led to its extensive clinical usage. It is now utilized as an integral part of the patients' clinical evaluation in the field of respiratory and cardiovascular medicine, sports medicine, surgery as well as occupational and rehabilitative medicine. It has a clinical role in assessing patient's functional capacity, monitoring disease progression and response to therapy, predicting prognosis, and perioperative morbidity and mortality, as well as constructing and monitoring training and rehabilitative programs. This article aims to give an overview of the physiological profiles obtained from cardiopulmonary exercise testing, its methodological aspects, as well as its utility in research and clinical practice. KEYWORDS: Cardiopulmonary, exercise, physiology, respiratory medicine, oxygen consumption
We evaluated the use of Desflurane anaesthesia in this prospective observational audit in the University of Malaya Medical Centre Day Surgery Unit. Fifty ASA I-II unpremedicated day surgery patients received fentanyl and propofol induction after preoxygenation. Desflurane was introduced initially at 2% and the concentration was increased gradually to 4%, then 6%, 8% and 10% in nitrous oxide and oxygen. Patients breathed spontaneously throughout the surgery. Desflurane was switched off at the end of surgery and patients breathed 100% oxygen. The haemodynamic effect, perioperative complications and recovery profiles were recorded. Systolic arterial pressure and heart rate decreased after induction of anaesthesia but returned to baseline value at discharge. Adverse airway event such as coughing and postoperative nausea and vomiting are two unwanted complications. KEYWORDS: Desflurane, day surgery, propofol induction
MeSH terms: Ambulatory Surgical Procedures; Hospitals; Humans; Malaysia; Medical Audit
Six cooling towers and eleven sources of potable water in a university campus in Kuala Lumpur were surveyed for the presence of legionellae. One nonmedical building cooling tower and three hot water systems from one ward of the hospital tested positive for Legionella, two of which contained Legionella pneumophila serogroup 1. The identification of Legionella was based on isolation, immunofluorescence and polymerase chain reaction (PCR).
Malaysia, like many aspiring developing countries, is undergoing a health transition that has seen the concomitant decrease in communicable diseases and increase in chronic diseases due to urbanization, modernization and ageing population. Health in the Malaysian society will thus increasingly focus on emerging problems that are both chronic and infectious in nature, such as, heart disease, diabetes, cancer, mental health, hepatitis and HIV/AIDS. Re-emerging diseases previously well-controlled, such as, tuberculosis for instance is another addition to these immediate health issues facing Malaysian society today. Despite the tremendous health gains and above average health status that Malaysians now enjoy, we are compelled to take stock of these urgent issues as well as to anticipate and handle serious challenges to our health in the 21st century. In this paper, we review the changing trends and discuss related challenges in disease pattern, environmental health, demographic impacts on health, migration influxes and health, effects of globalization on health, mental health and wellness as well as fundamental access and equality in health care. Being proactive, resilient and innovative, Malaysian society would forge ahead towards our Vision for Health in this new era. KEYWORDS: Society and health, health trends and issues, Vision for Health, Malaysia
Sea bass (Lates calcarifer) is an economically important fish in Malaysia. In this study, a genomic library of L. calcarifer was constructed. Genomic DNA was isolated from the muscle tissue of sea bass, sheared by nebulisation, blunt-end repaired and ligated into the pCR®4Blunt- TOPO® plasmid vector. The ligation mixture was then transformed into Escherichia coli. In order to characterize the constructed genomic library, plasmid DNA was extracted from randomly selected recombinant clones. Gel electrophoresis showed that these recombinant clones contain inserts with a size range of 0.5 kb - 3.5 kb, with an average size of 1.7 kb. DNA sequencing was then carried out using the extracted DNA plasmid as template, and a total of 121 random sequences were generated from the L. calcarifer genomic library. Analysis of these sequences implies that the library is representative of L. calcarifer genome. Based on sequence similarity database searches, 17% of the random sequences were found to have significant BLAST hits, indicating that they represent L. calcarifer genes. Analysis using the Repeat Masker program reveals that 35% of the random sequences were identified as repeat elements. Initial characterization of this genomic library indicates that it is a potentially useful resource in the study of the L. calcarifer genome.
[Siakap (Lates calcarifer) merupakan spesies ikan yang penting dari segi ekonomi di Malaysia. Dalam kajian ini, satu perpustakaan genom L. calcarifer telah dibina. DNA genom telah dipencil daripada tisu otot L. calcarifer, diserpih secara nebulisasi, dibaiki hujung tumpul dan diligasi ke dalam vektor plasmid pCR®4Blunt-TOP®. Campuran ligasi seterusnya telah ditransformasikan ke dalam Escherichia coli. Bagi mencirikan perpustakaan genom yang terhasil, DNA plasmid telah diekstrak daripada klon-klon rekombinan yang dipilih secara rawak. Elektroforesis gel agaros menunjukkan klon-klon rekombinan ini membawa selitan DNA yang bersaiz di antara 0.5 kb - 3.5 kb, dengan purata saiz 1.7 kb. Seterusnya, penjujukan DNA telah dijalankan dengan menggunakan DNA plasmid yang diperoleh sebagai templat. Sebanyak 121 jujukan rawak telah dihasilkan daripada perpustakaan genom L. calcarifer ini. Analisis jujukan rawak memberikan implikasi yang perpustakaan ini adalah representatif bagi genom L. calcarifer. Berdasarkan persamaan dengan jujukan dalam pangkalan data, 17% jujukan rawak ini didapati mempunyai keputusan BLAST yang bermakna, yang menunjukkan mereka mewakili gen L. calcarifer. Analisis dengan menggunakan perisian RepeatMasker menunjukkan sebanyak 25% jujukan rawak ini dikenal pasti sebagai unsur berulang. Pencirian awal terhadap perpustakaan genom ini menunjukkan ia berpotensi sebagai sumber yang berguna dalam kajian genom L. calcarifer].
Stem cells, also known as mother cells are capable of undergoing both cell division and differentiation. The most primitive stem cells are totipotent cells which are capable of producing a complete organism from one cell. There are two types of haemopoietic stem cells depending on their developmental stages known as embryo and adult haemopoietic stem cells. Studies showed that only 0.01-0.05% of total bone marrow cell population consists of haemopoietic stem cells. This small population of stem cells exists in three different sizes with different characteristics. In addition, the microenvironment which contains various regulatory molecules plays an important role in the differentiation of stem cells into specific adult cells.
[Sel stem juga dikenali sebagai sel induk berupaya untuk menjalani kedua-dua proses pembahagian dan pembezaan sel. Sel stem yang paling primitif iaitu sel totipoten berupaya untuk membentuk satu organisma lengkap daripada satu sel. Sel stem hemopoietik terdiri daripada dua jenis bergantung kepada peringkat perkembangan individu iaitu sel stem hemopoietik embrio dan dewasa. Kajian mendapati hanya 0.01-0.05% daripada keseluruhan populasi sel sumsum tulang berupaya bertindak sebagai sel stem hemopoietik. Daripada julat yang kecil ini sel stem hemopoietik wujud dalam tiga saiz yang mempunyai ciri yang berbeza. Selain daripada itu mikrosekitaran yang mempunyai molekul-molekul regulatori yang berbeza-beza juga memainkan peranan yang penting dalam pembezaan sel stem kepada sel-sel matang yang spesifik].
In this work we use an analytical technique to analyse the effect of a vertical uniform magnetic field on the onset of steady Benard-Marangoni convection in a horizontal layer of electrically conducting fluid subject to a uniform vertical temperature gradient in the asymptotic limit short waves. We found that in the limit of short waves, the leading order expression for the marginal curve is not affected by the magnetic field.
Dalam makalah ini kesan medan magnet menegak seragam ke atas lengkung sut permulaan olakan mantap Benard-Marangoni dalam lapisan bendalir mengufuk berpengalir elektrik dikaji tertakluk kepada kecerunan suhu yang seragam dalam had asimptot gelombang pendek. Kami dapati medan magnet tidak memberi kesan kepada sebutan utama lengkung sut dalam had gelombang pendek.
MeSH terms: Electricity; Radio Waves; Temperature; Convection; Magnets; Magnetic Fields
This paper offers a technique to create a development index among districts. To determine the weight for each criterion in the index entropy theory was used. Two approaches for criteria normalization were also suggested. The data obtained from 1991 census conducted in Peninsular Malaysia were utilized as illustration.
Kertas ini mencadangkan teknik pembinaan indeks kemajuan daerah. Teori entropy digunakan untuk menentukan pemberat bagi kriteria yang digunakan dalam pembinaan indeks. Dua pendekatan menormalkan data turut dicadangkan. Contoh pembinaan indeks dikemukakan berdasarkan kemudahan asas yang terdapat di daerah-daerah di Semenanjung Malaysia seperti yang diperoleh berdasarkan banci tahun 1991.
MeSH terms: Aspirin; Body Weight; Esterases; Malaysia; Entropy; Censuses
Total Variance (TV) and Generalized Variance (GV) are commonly used as a measure multivariate dispersion. However, these two statistics has some drawbacks. This paper proposes a new measure of multivariate dispersion, named Vectorial Variance (VV) an inner product for set of operators defined on a Hilbert-Smith space. Since, the exact sampling distribution of VV is difficult to find, therefore the asymptotic sampling distribution is obtained.
[Jumlah Varians dan Varians Teritlak kebiasaannya digunakan sebagai ukuran dispersi multivariate. Namun begitu, kedua-dua statistik ini mempunyai beberapa kelemahan. Dalam tulisan ini akan dicadankgan satu ukuran dispersi multivariate yang baru, dikenali sebagai varians bervektor (VV) yang merupakan suatu hasil darab terkedalam bagi set pengoperasi yang tertakrif ke atas suatu ruang Hilbert-Smith. Oleh kerana taburan pensampilan tepat dari statistik vv tersebut sangat sukar untuk ditentukan, maka taburan pensampilan asimtot telah diperolehi].
The development of economy is closely related with the inflation rate of the country. Generally the inflation can be measured by the Consumer Price Index (CPl). The aim of this paper is using overlapping measure and cumulative measure to measure the inflation. In overall, these two methods are adequate for measuring the inflation. As a result, monthly measure is useful because it believe can give a perfect measure (since its sample is large) and can get rid of or smaller the error. Besides that, the value of the weighted CPl and the unweighted CPl are almost same. As the result, the unweighted of CPl is used to measure the inflation. The result of this two methods are satisfactory.
[Perkembangan sesuatu ekonomi adalah berkait rapat dengan kadar inflasi dalam sesebuah negara. Secara amnya, inflasi dapat diukur dengan Indeks Harga Pengguna (IHP). Tujuan kertas kerja ini adalah mengukur inflasi dengan menggunakan kaedah data bertindih dan kaedah kumulatif. Pada keseluruhannya kedua-dua kaedah tersebut adalah sesuai digunakan sebagai pengukuran inflasi. Oleh hal yang demikian, pengukuran secara bulanan digunakan kerana dipercayai bahawa ia dapat memberi ukuran yang lebih tepat (saiz sampel yang besar) dan dapat mengelakkan atau mengecilkan ralat berlaku. Selain itu, penggunaan IHP berpemberat dan IHP tanpa pemberat didapati mempunyai nilai yang hampir sama. Oleh itu, nilai IHP tanpa pemberat digunakan dalam pengukuran inflasi. Keputusan yang didapati daripada kedua-dua kaedah tersebut adalah memuaskan]
MeSH terms: Environment; Inflation, Economic; Insufflation; Paper
A study was carried out to determine the distribution of nutrient, chlorophyll-a and the physical properties of water at Setiu Wetland from May-October 2001. Ten sampling stations were selected to represent various locations within the study area. The analyses of dissolved nutrients and chlorophyll-a were carried out based on colorimetric methods while the physical parameters were measured in situ. The results indicated that pH values between 5.15-8.03, dissolved oxygen 4.89-6.85 mg/L, biological oxygen demand 0.04-1.80 mg/L and total suspended solids 1.3-19.7 mg/L. The concentrations of orthophosphate, total dissolved phosphate, nitrate, ammonia, total dissolved nitrogen and chlorophyll-a were in the range of 0.19-2.85 μg P/L, 1.06-25.81 μg P/L, 1.48-89.66 μg N/L. 6.0-125.7 μg N/L. 122.50-432.34 μg N/L and 0.03Â4.32 mg/L, respectively. In addition, the results obtained also suggest possible linkage between land use practices and deteriorations of water quality in the wetland area.
[Satu kajian telah dijalankan untuk menentukan taburan nutrien, klorofil-a dan sifat fizikal air di Tanah Bencah Setiu dari bulan Mei-Oktober 2001. Sepuluh stesen pensampelan telah dipilih untuk mewakili kawasan-kawasan yang berlainan di kawasan kajian. Analisis nutrien terlarut dan klorofil-a dijalankan berdasarkan kaedah kolorimetrik manakala parameter fizikal diukur secara in situ. Hasil kajian menunjukkan bahawa pH mempunyai nilai antara 5.15-8.03, oksigen terlarut 4.89-6.85 mg/L, permintaan oksigen biokimia 0.04-1.80 mg/L dan jumlah pepejal terampai 1.3-19.7 mg/L. Kepekatan ortofosfat, jumlah fosfat terlarut, nitrat, ammonia, jumlah nitrogen terlarut dan klorofil-a adalah masing-Âmasing dalam julat 0.19-2.85 μg P/L, 1.06-25.81 μg P/L, 1.48-89.66 μg N/L, 6.0-125.7 μg N/L, 122.50-432.34 μg N/L dan 0.03-4.32 mg/L. Disamping itu, keputusan yang didapati turut mencadangkan kemungkinan wujudnya hubungan antara kepelbagaian aktiviti guna tanah dan kemerosotan kualiti air di kawasan tanal: bencah].
Artificial neural network (ANN) was used in this study to determine water turbidity by using back propagation algorithm. Three wavelengths which represent reflectance intensity for eight standard samples were used as training input. The finding from the study shows that the trained network with number of epochs of 250,000 and learning rate of 0.001 gave the lowest sum of squared error (SSE) of 0.04. ANN was able to predict the turbidity of water based on the pattern recognition of the reflectance spectrum. The architecture of optimized ANN used in this study was 3:25:1. The average prediction error was 0.02.
[Jaringan neural tiruan (ANN) dengan lagoritma perambatan balik (BP) telah digunakan dalam kajian ini untuk menentukan kekeruhan air. Tiga panjang gelombang yang mewakili serapan bagi lapan sampel telah dipilih sebagai imput latihan. Hasil kajian menunjukkan bagi jaringan terlatih dengan bilangan ulangan latihan 250,000 dan kadar pembelajaran 0.001 telah memberikan nilai SSE yang terendah iaitu 0.04. Dalam kajian ini jaringan ANN didapati boleh menentu dan meramalkan nilai kekeruhan sample air berdasarkan corak serapan pantulan. Arkitektur yang sesuai bagi kajian ini adalah 3:25:1. Purata ralat ramalan adalah 0.02].
This study focused on the development and optimization of a hybrid material formed from sol-gel and chitosan which could be used as a chemical sensing material. It is hoped that this new matrix can overcome certain weaknesses in solÂgel and chitosan materials. Dip-coating technique was used to prepare the film on microscope glass slide which functioned as a solid support. For optimization purposes, thymol blue was chosen as a pH indicator and was entrapped in the film. The film was characterized using uv-Visible Spectrophotometer. Morphology studies of the surface of the film were carried out using Scanning Electron Microscope (SEM). Results indicated that the most suitable solgel: chitosan ratio for hybrid formation was 60:40 after considering the surface morphology of the film, leaching, response time and also the intensities of the spectrum. Besides that, the results also show that the pH indicator could be successfully entrapped inside the hybrid film and would still retain its chemical behavior just as in solution. The sensing material was found to have good repeatability when reacted with buffer solution and showed RSD values of 4.24 % and 5.96 % in buffer solution at pH 2.0 and pH 11.0, respectively. The entrapped indicator also showed good photo stability with RSD of 5.35 % for the duration of 8 hours. However; the reproducibility of the hybrid film was quite low with a RSD value of 18.40 % and 31.22 % at wavelength of 500 nm and 600 nm, respectively due to leaching.
[Penyelidikan ini difokuskan kepada pembangunan dan pengoptimuman bahan hibrid antara sol-gel dan kitosan untuk membentuk suatu matriks baru bagi penyediaan bahan penderia kimia yang dapat mengatasi kekurangan tertentu dalam bahan sol-gel danjuga kitosan. Teknik penyalutan celup telah digunakan untuk penyediaan filem nipis di atas penyokong slaid kaca mikroskop. Untuk tujuan pengoptimuman, timol biru dipilih sebagai penunjuk pH dan dipegunkan di dalam filem. Filem nipis dicirikan menggunakan Spektrofotometer UL-Nampak. Kajian morfologi ke atas permukaan filem pula dilakukan dengan menggunakan Mikroskop Imbasan Elektron (MIE). Keputusan yang diperolehi menunjukkan bahawa nisbah sol-gel:kitosan yang paling sesuai ialah 60:40 dengan mempertimbangkan dari segi morfologi permukaan filem, kelarutresapan, masa rangsangan dan juga keamatan spektrum. Selain itu, keputusan menunjukkan bahawa penunjuk pH berjaya dipegunkan dalam filem hibrid sol-gel-kitosan dan mampu mengekalkan sifat kimianya sebagaimana dalam larutan. Bahan penderia kimia ini didapati mempunyai kebolehulangan yang baik apabila bertindak dengan larutan penimbal dan menunjukkan nilai RSD yang baik iaitu 4.24% dan 5.96% dalam larutan penimbal pH 2.0 dan pH 11.0, masing-masingnya. Penunjuk pH terpegun turut menunjukkan kestabilan foto yang baik (RSD = 5.35%) untuk tempoh 8 jam. Walau bagaimanapun, kebolehasilan filem agak rendah dengan RSD yang bernilai 18.40% dan 31.22 % pada panjang gelombang 550 nm dan 600 nm masing-masing akibat daripada kelarut resapan].
The present study was to investigate the use of granular activated charcoal (GAC) as a potential material for removal of toxic aliphatic compounds by adsorption. Commercial granular charcoal was degassed at 105°C, 300°C and 800°C for a period of twenty-four hours, which was then used as an adsorbent for the adsorption of methylamine, dimethylamine and trimethylamine from their aqueous solutions at 25°C. The time dependence studies showed that four hours are the optimum time for the maximum adsorption of the alkylamines, irrespective of their nature and concentrations (0.005M & 0.01M). Adsorption was greater from higher concentration than lower concentration of adsorbate solution. Lower adsorption of alkylamines was observed when the charcoal was evacuated at high temperature. The adsorption sequence of alkylamines followed the order dimethylamine > trimethylamine > methylamine. The amount of adsorption using different adsorption isotherm, i.e. Freundlich and Langmuir were evaluated. L-type isotherms were also observed for the adsorption data. Further, the Langmuir and Freundlich isotherms were found applicable to the adsorption data and the values of the adsorption capacity i.e. "k" and monolayer adsorption capacity "b" were calculated and in agreement with the adsorption patterns.
[Kajian dilakukan untuk melihat kegunaan arang teraktif granul sebagai bahan berpotensi untuk mengeluarkan sebatian alifatik toksik dengan jerapan. Arang granulat komersial dinyahgas pada 105°C, 300°C dan 800°C untukj angka masa 24 jam dan seterusnya digunakan sebagai penjerap bagi jerapan metilamina, dimetilamina dan trietilamina dari larutan akueus pada 25°C. Kajian kebergantungan masa menunjukkan bahawa masa optimum untuk jerapan maksimum alkil amina ialah 4 jam, tidak kita bentuk dan kepekatan (0.005M & 0.01 M). Pencapaian jerapan adalah lebih tinggi pada kepekatan tinggi dibandingkan dengan larutan jerap berkepekatan rendah. Jerapan rendah oleh alkilamina diperhatikan apabila arang dinyahgas pada suhu tinggi. Susunan jerapan alkilamina diperhatikan apabila arang dinyahgas pada suhu tinggi. Susunan jerapan alkilamina mengikut tertib dimetilamina > trimetilamina > metilamina. Amaun jerapan menggunakan isoterma jerapan berbeza, iaitu Freundlich dan Langmuir telah dinilai Isoterma jenis juga diperhatikan untuk data jerapan. Tambahan pula, isoterma Freundlich dan Langmuir didapati berguna untuk data jerapan dan nilai kapasiti jerapan, iaitu 'k' dan kapasiti jerapan lapisan mono dihitung dan didapati konsisten dengan corak jerapan].
Blends of fiber-reinforced rubber (FRR) based on natural rubber-thermoplastic (NR/LLDPE) and epoxidized natural rubber Âthermoplastic (ENR/LLDPE) reinforced by aramid fibre have been done using melt blending process. Twaron aramid fibres (Teijin-Twaron) used in this project were treated with epoxy adhesion activated and resorcinol formaldehyde latex (RFL). It was found that with increasing amount of aramid fibre led to increase the maximum stress, tensile modulus, impact strength and hardness of the composites while the strain at break decreased rapidly. The results show that the optimum composition of filler loading in NR/LLDPE blend is 20%. However, in the case of the ENR/LLDPE composite, the tensile strength and modulus increase with increasing amount of the fibre above 20%. The results indicate that the interfacial adhesion between ENR/LLDPE and aramid is better than for the NR/LLDPE.
[Penyediaan adunan getah asli termoplastik dan getah asli terepoksida termoplastik yang diperkuat dengan gentian aramid telah dilakukan melalui proses adunan leburan. Gentian aramid yang digunakan adalah gentian pendek Twaron (Teijin-Twaron) yang dirawat dengan bahan pelekat epoksi dan resorcinolformaldehid latex (RFL). Hasil yang diperolehi menunjukkan bahawa kesan penambahan gentian aramid telah meningkatkan tegasan maksima, modulus regangan, kekuatan hentaman dan kekerasan kedua-dua adunan tersebut tetapi menurunkan nilai terikan pada takat putus. Bagi adunan NR/LLDPE didapati komposisi gentian yang paling optima adalah pada 20%. Penambahan gentian aramid seterusnya hanya menurunkan sifat mekanik adunan. Sebaliknya bagi adunan ENR/LLDPE, didapati komposisi gentian melebihi 20% masih menunjukkan peningkatan tegasan maksima dan modulus regangan. Keputusan ini menunjukkan bahawa interaksi antaramuka gentian aramid dan matriks dalam adunan ENR/LLDPE lebih baik berbanding NR/LLDPE].
IAEA in its publication year 2000 has recommended a worksheet for the determination of absorbed dose to water in an electron beam. We evaluated the worksheet via an absorbed dose to water determination work at a local radiotherapy center using a 12 MeV electron beam. We found that if several modifications are made, this IAEA worksheet will become more user-friendly and could facilitate and fasten the process of quality assurance audit. The modifications are given and discussed.
[IAEA dalam penerbitannya tahun 2000 telah mengesyorkan satu helaian kerja untuk menentukan dos terserap kepada air dalam alur electron. Helaian kerja ini dinilai melalui satu kerja penentuan dos terserap kepada air di satu Pusat radioterapi tempatan menggunakan satu alur electron 12 MeV. Sekiranya beberapa pengubahsuai dibuat, helaian kerja IAEA ini akan menjadi lebih mesra pengguna dan dapat mempermudahkan dan mempercepatkan lagi proses audit jaminan kualiti. Pengubahsuaian ini diberikan dan dibincangkan].
Amang are by-products obtained when tailings are processed into concentrated ores and other economical products such as monazite, (Ce, La, Th)PO4; zircon, ZrSiO4; ilmenite, FeTiO3; struverit; and xenotime, YPO4. Its could be extracted from amang for further usage. Tailings from these ores may have a significant potential to cause elevated radiation exposures. This project was carried out to measure the concentration of uranium and thorium in the waste and products produced after the processing of the amang and ilmenite ore. The concentration of uranium and thorium was determined using gamma ray spectrometer with HPGe detector. The concentration of uranium was determined by measuring the intensity of gamma ray emitted from its daughter nuclei 214Pb at 352 keV and 214Bi at 609 keV while the concentration of thorium was determined by measuring the intensity of gamma rays emitted from its daughter nuclei 228Ac at 911 keV and 208Tl at 583 keV. The concentration of uranium and thorium in ppm obtained in this study are as follows: raw amang (83 -383) and (174 - 1566); ilmenite (149 - 290) and (301- 575); monazite (2303 - 4070) and (9641 – 60061); zircon (963 - 1192) and (353 - 583) and waste (22 - 98) and (44 - 223) respectively. Rutile and iron oxide was obtained from ilmenite. The concentration of uranium and thorium in rutile was 50 and 72 ppm and from iron oxide was 336 and 379 ppm respectively. These values are considered high compare to normal sand and could pose danger to the surrounding.
[Amang adalah hasil sampingan yang diperoleh semasa pengekstrakan tahi timah kepada logam tulennya. Pelbagai hasil yang berekonomi seperti monazit, (Ce,La,Th)YPO4; zirkon, ZrSiO4; ilmenit, FeTiO3; struverit; dan xenotim, YPO4 boleh diekstrak daripada amang bagi kegunaan seterusnya. Pemprosesan tahi bijih ini berkeupayaan mendatangkan pendedahan sinaran yang tidak diingini. Kajian ini dijalankan untuk menentukan kandungan uranium dan torium yang terkandung dalam sisa dan hasil yang dikeluarkan semasa pemprosesan amang dan ilminit. Kepekatan kandungan uranium dan tarium ditentukan menggunakan spektrometer sinar gama dengan pengesan HPGe. Kandungan uranium ditentukan dengan mengukur keamatan sinar gama yang dipancarkan daripada nukleus anaknya, iaitu 214Pb pada tenaga 352 keY dan 214Bi pada tenaga 609 keY, manakala kandungan torium ditentukan dengan mengukur keamatan sinar gama yang dipancarkan oleh nukleus anaknya, iaitu 228Ac pada tenaga 911 keY dan 208Tl pada 583 keY. Kandungan uranium dan torium dalam ppm yang diperoleh daripada kajian ini masing-masing adalah seperti berikut: amang mentah (83 - 383) dan (174 -1566); ilmenit (149 - 290) dan (301 - 575); monazit (2303 - 4070) dan (9641 - 60061); zirkon (963 -1192) dan (353 -583) dan sisa (22 - 98) dan (44 - 223). Kandungan uranium dan torium dalam rutil masing-Âmasing ialah 50 and 72 ppm, manakala dalam ferum oksida ialah 336 dan 379 ppm. Nilai yang diperolehi ini adalah tinggi berbanding dengan pasir biasa semula jadi dan berpotensi mendatangkan kemudaratan kepada persekitaran].