This paper describes the effect of pro-degradant additives (PDA) on photo-oxidative aging of polypropylene (PP) films after being time accelerated in UV-weathering chamber. Thin films (0.12 mm) containing these additives were prepared by sheeting process. The effect of UV on PP films in the presence of these additives was investigated. Changes in the PP films appearance, tensile properties and carbonyl index (CI) were used to investigate the degradation behavior. The films became completely pulverised after 100 h of photo-oxidative treatment and could not be tested further. Films containing PDA showed rapid loss in tensile properties within 100 h of photo-oxidative aging. In addition, the CI results of photo-oxidative films increased with increasing PDA amount within the time interval of aging and the activity was due to the mechanism reaction of PP with PDA particles. During the aging process the material becomes denser due to tighter packing and incorporation of oxygen into the amorphous regions of the polymer. The results indicated that the presence of PDA contributed to the photo degradation and the activity was very much influenced by the amount PDA.
Working environmental conditions in automotive industry are very challenging to the human workers. Meanwhile, products quality is very much dependent on workers’ health, safety and comfort in their working environment. Environmental factors, such as temperature, illuminance and humidity levels have significant effect on workers’ performance at the production line. In this experiment, temperature, humidity, illuminance levels and productivity rate were observed in a control room. An automotive manufacturing firm production line was chosen to be simulated in the control room to observe the temperature, relative humidity, illuminance and worker’s productivity rate. The experimental data collected was analyzed using Response Surface Method (RSM). RSM is an analysis technique, which combined statistical systems and mathematical methods. It can be applied for research and development, reform and optimize a process, which involves several design variables. As a result, the combined effect of temperature, illuminance and humidity toward productivity can be clearly seen. Optimum environmental factor cannot be predicted using first order RSM analysis because it gives low reliability for obtaining the optimum level. Thus, a second order RSM analysis was generated for obtaining the optimum level of environmental factors.
Suatu kajian telah dijalankan untuk menentukan potensi makroinvertebrat bentik sebagai penunjuk biologi di hulu Sungai
Ikan, Terengganu. Sebanyak lima stesen pensampelan telah dipilih untuk pensampelan makroinvertebrat bentik dan
analisis kualiti air. Pensampelan makroinvertebrat bentik telah dilakukan menggunakan jaring Surber dan analisis
kualiti air dilakukan menurut kaedah APHA. Piawaian Kualiti Air Kebangsaan (NWQS) telah digunakan untuk menilai
parameter kualiti air di kawasan kajian dan hasil menunjukkan Sungai Ikan berada dalam keadaan baik iaitu kelas I
hingga II. Ujian ANOVA satu hala menunjukkan bahawa kesemua parameter air yang diuji adalah seragam di sepanjang
kawasan kajian (p>0.05, α=0.05). Sebanyak 2 filum, 3 kelas, 8 order, 39 famili dan 1353 individu telah dikenal pasti dan
didominasi oleh famili Baetidae, Siphlonuridae, Simuliidae, Chironomidae dan Elmidae. Famili dominan didapati hadir
pada hampir kesemua stesen pensampelan. Memandangkan kualiti air adalah baik dan tidak berubah sepanjang kawasan
kajian, ujian CCA dilakukan untuk memperlihatkan faktor persekitaran lain yang mempengaruhi sebaran makroinvertebrat
terutamanya famili dominan. Hasil ujian CCA menunjukkan pengaruh persekitaran yang khusus terhadap famili tertentu
dan mempunyai pengaruh yang kuat terhadap sebaran makroinvertebrat bentik. Ujian korelasi menunjukkan batuan
besar mempunyai pengaruh besar terhadap sebaran famili Baetidae, Siphlonuridae dan sub-famili Orthocladiinae,
manakala komposisi pasir pula mempunyai pengaruh terhadap famili Elmidae. Hasil kajian ini menunjukkan dalam
ekosistem yang bersih, faktor persekitaran habitat adalah kritikal untuk diambil kira dalam menentukan taksa tertentu
yang sesuai digunakan sebagai penunjuk biologi ekosistem sungai rekreasi.
Epoxidized natural rubber (ENR-50) has been used as a compatibilizer for natural rubber-recycled acrylonitrile-butadiene
rubber (NR/NBRr) blends, vulcanized by sulfur. NBR gloves have excellent resistance to punctures, tear and many types
of chemicals, while NR has good physical and mechanical properties. Incorporation of ENR-50 into the rubber blends
has improved processability, stiffness, resilience and excellent oil resistance. NR/NBRr blends were prepared by two-roll
mill with five different compositions with the ENR-50 content fixed at 10 phr. Cure characteristics, mechanical properties
and morphology (SEM) studies were performed to determine the compatibility of NR/NBRr blends in the presence of ENR-
50. The cure characteristics showed that NR/NBRr blends with the presence of ENR-50 have lower scorch time (ts2) and
cure time (t90) than NR/NBRr blends without ENR-50. However, the NR/NBRr blends with ENR-50 exhibited higher minimum
torque (ML
) and maximum torque (MH) which indicated difficult processability of the blends after compatibilization.
Incorporation of ENR-50 into NR/NBRr blends improved all the tensile properties (tensile strength, tensile modulus and
elongation at break) compared with NR/NBRr blends without ENR-50. The improvement in hardness upon compatibilization
is due to an increase in crosslink density. Scanning electron microscopy (SEM images) of the fracture surfaces indicates
that, with the addition of ENR-50 in NR/NBRr blends, better adhesion between NR and NBRr was obtained, thus improving
the compatibility of NR/NBRr blends.
The integration of human knowledge between the medical and health care sciences with revealed knowledge was established since the era of Al-Razi (Rhazes), Ibn Sina (Avicenna), Ibn Rushd (Averroes), AlZahrawi (Albucasis) and others. However, the glorious period of Islamic medicine gradually declined after the period of 'Abbasiyyah and 'Uthmaniyyah. At present, many scholars tend to separate the modern medicine and the revealed knowledge, resulting in the disconnection between these two fields. There is little to suggest the presence of reference collections that integrate the Qur’an and Hadith with medicine. This review aimed to fill that gap. Relevant Qur’anic verses and authentic Hadith of the Prophet Muhammad (peace be upon him; henceforth PBUH) in relation to a specific field in medicine i.e. the anatomy of human musculoskeletal system was extracted. The musculoskeletal system is unique in which it forms the ‘backbone’ of normal human posture. The system plays a vital role in maintaining human daily activities. From this review, it is noted that many Qur’anic verses and Hadith relate to the musculoskeletal system. A few examples include the number human joints and its relationship with the daily prayers (Salah), the daily charitable act recommended to all Muslim, the coccyx bone that is indestructible and shall be the source for human resurrection during the hereafter, and others. These examples necessitate for a more in-depth analysis to enlighten the revealed knowledge from the medical perspective.
CAD accounts for 25% of mortality in Malaysia public hospitals. CABG is one of treatment for patients with CAD, but requires RBC transfusion, which is associated with morbidity and mortality. This study was to evaluate the association between RBC transfusion and morbidity and mortality in CABG patients at the National Heart Centre, Malaysia (IJN). Methods: Retrospective cross-sectional study performed using data from 434 patients who underwent CABG in 2013 and 2014. Subjects had systematic random sampling every fifth subject of the patients in the sequence of dates of the year. Data related to the relationship between RBC transfusion with mortality and morbidity, and the predicting factors captured. Results: 64.3% of CABG patients (n = 279) received RBC transfusion perioperatively. Age, gender, BMI, and EF, were factors that contributed for RBC transfusion. RBC transfusion was a contributor to longer intensive care unit length of stay (ICULOS) and hospital length of stay (HLOS). Multiple logistic regression revealed, for every 1 year increase of age, there is 3.5% higher chance of transfusion. Whereas an increase of 1 kg/m2 of BMI and 1% of EF reduced the odds of RBC transfusion by 13.0% and 3.0% respectively. Conclusions: Age, gender, BMI, and EF determine the probability of needing RBC transfusion during CABG, and RBC transfusion will result in longer ICULOS, and HLOS. Probability of RBC transfusion will be higher in older patients and reduced in those with higher BMI and EF.
This study aims to identify the expression of emotions and how emotions are controlled by adolescents. The sample comprised three male and two female students who were from a secondary school located in Penang. Semi-structured interviews were conducted in this study. Transcribed contents of the interviews were analyzed. The main findings showed generally, adolescents like to have fun, seek to try something new, like to relax with friends, and they also follow their feelings. Female adolescents were found to be sensitive. Generally, adolescents indicated that they were more comforlable sharing problems with friends than with parents. Implications of findings area also discussed.
The determination technique for U (238U, 235U, 234U) and Th (232Th, 230Th, 228Th) isotopes using alpha spectrometry was developed. The developed technique involved digestion, dissolution, coprecipitation, solvent extraction and electrodeposition methods. The NBS River Sediment and Rocky Flats Soil Standard Reference Materials were analysed to determine the accuracy of the technique. A good accuracy and high percentage recovery of the carrier (70 - 90%) indicated that the developed technique was suitable for U and Th isotopes determination. The technique was used to determine the U and Th concentration in monazite, xenotime and zircon samples. The results showed that the U and Th total concentrations were in the range of 21.03 to 171.25 Bq/g and 27.48 to 242.87 Bq/g respectively.
Kaedah penguraian, pemelarutan, pemendakan bersama, ekstraksi pelarut dan pemendapan elektrik telah dikaji dan digunakan untuk mendapatkan suatu teknik yang terbaik dalam penentuan isotop uranium 234U, 235U & 238U) dan torium 228Th, 230Th & 232Th) menggunakan sistem spektrometri alfa. Kepekatan isotop U dan Th dalam bahan rujukan piawai River Sediment dan Rocky Flats Soil (NBS) telah dianalisis untuk menentukan kejituan teknik yang dibangunkan. Kajian ini mendapati kepekatan isotop yang diperolehi adalah menghampiri nilai teraku (sijil) dan peratus perolehan semula pembawa yang besar (70-90%). Ini menunjukkan teknik yang dibangunkan sesuai digunakan untuk penentuan isotop uranium dan torium. Seterusnya teknik yang dibangunkan telah digunakan untuk menentukan kandungan uranium dan torium dalam sampel monazit, xenotim dan zirkon tempatan. Kepekatan jumlah isotop uranium yang diperolehi didapati berada dalam julat 21.03 - 171.25 Bq/g manakala kepekatan jumlah isotop torium pula terletak antara 27.48 - 242.87 Bq/g.
In this research we introduce an analyzing procedure using the Kullback-Leibler information criteria (KLIC) as a statistical tool to evaluate and compare the predictive abilities of possibly misspecified density forecast models. The main advantage of this statistical tool is that we use the censored likelihood functions to compute the tail minimum of the KLIC, to compare the performance of a density forecast models in the tails. Use of KLIC is practically attractive as well as convenient, given its equivalent of the widely used LR test. We include an illustrative simulation to compare a set of distributions, including symmetric and asymmetric distribution, and a family of GARCH volatility models. Our results on simulated data show that the choice of the conditional distribution appears to be a more dominant factor in determining the adequacy and accuracy (quality) of density forecasts than the choice of volatility model.
The primary source of water on many small islands is the fragile freshwater lens that floats on saline water in its shallow aquifer. The management of such a limited groundwater resource on these islands is seriously constrained by the occurrence of seawater intrusion. Sipadan Island, the renowned and only oceanic island in Malaysia, had experienced in the over-extraction of its groundwater for more than ten years to cater for freshwater demand associated with tourism activities. This paper discusses the output of modelling of seawater intrusion into the island’s aquifer using SEAWAT-2000. The findings indicated that the island’s coastal aquifer has been encroached by seawater. The infiltration of isochlor (chloride concentration) of 2.5 and 45% of seawater and freshwater mixing ratios has moved 63.4 m and 12.7 m inland from the coastline, respectively. The upconing event at the pumping well, as simulated by the three-dimensional model, showed that 14.5% of seawater-freshwater mixing ratio took place below the bottom of each well. Intensive and unregulated exploitation of groundwater from such an unconfined aquifer of the island by pumping wells contributed to the upconing. In order to protect the fresh groundwater resources in the study area from seawater intrusion, adjustment of groundwater pumping rate is needed. This study showed that the model is useful in demonstrating the mechanism and movement of freshwater-seawater interface in the island, and thus provide a powerful management tool for such an aquifer.
Organomontmorillonites were synthesized by grafting cationic surfactants i.e quaternary ammonium compounds into the interlayer space and were characterized using XRD, FTIR and N2 adsorption/ desorption analysis. The organomontmorillonites were applied as catalyst for the esterification of glycerol (GL) with lauric acid (LA). The catalyst which had symmetrical onium salts (tetrabuthylammoniumbromide, TBAB) gave higher activity than that of unsymmetrical onium salts (cetyltrimethylammoniumbromide, CTAB). Over the TBAB-montmorillonite catalyst, glycerol monolaurate was obtained with a selectivity of about 80%, a lauric acid conversion of about 71% and a glycerol monolaurate yield of about 57%.
Magnetic induction in the superconductor (B=H +4πM) in the zero field cooled samples (ZFC) is not equal to zero. Depending upon the chemical environment it has negative value in some and positive values in some others. In the field cooled samples, the magnetization becomes paramagnetic. We have calculated the band structure of one layer of FeAs lattice with spin polarized as well as unpolarized orbitals as a function of doping by Li atoms. For n number of Li atoms (n=0, 1,…, 4), we calculated the band gap at all of the k-points as well as the Fermi energy. The reduced normal state gap was found to lead to superconductivity.
A high-order uniform Cartesian grid compact finite difference scheme for the Goursat problem is developed. The basic idea of high-order compact schemes is to find the compact approximations to the derivatives terms by differentiating centrally the governing equations. Our compact scheme will approximate the derivative terms by involving the higher terms and reducing the number of grid points. The compact finite difference scheme is given for general form of the Goursat problem in uniform domain and illustrates the performance by applying a linear problem. Numerical experiments have been conducted with the new scheme and encouraging results have been obtained. In this paper we present the compact finite difference scheme for the Goursat problem. With the aid of computational software the scheme was programmed for determining the relative errors of linear Goursat problem.
In this paper, a new reliable method called the step variational iteration method (SVIM) based on an adaptation of the variational iteration method (VIM) is presented to solve non–chaotic and chaotic systems. The SVIM uses the general Lagrange multipliers for constructing the correction functional for the problems. The SVIM yields a step analytical solution of the form of a rapidly convergent infinite power series with easily computable terms and obtain a good approximate solution for larger intervals. The accuracy of the presented solution obtained is in an excellent agreement with the previously published solutions.
Dalam kajian ini, kesan surfaktan tak-ionik terhadap kompleks Al(III)-morin telah dijalankan. Surfaktan tak-ionik didapati telah meningkatkan bacaan serapan kompleks Al(III)-morin. Penambahan triton X-100 kepada kompleks Al(III)-morin telah membolehkan penentuan ion Al(III) dalam kuantiti submikrogram pada pH4.00 dijalankan. Bacaan serapan maksimum adalah pada 425 nm dengan serapan molar, ε, 9.31 × 103 l.mol-1cm-1. Graf kalibrasi bagi penentuan ion Al(III) adalah linear daripada 0.03 hingga 2.0 μg mL-1 dengan had pengesanan 0.015 μg mL-1 telah diperoleh dalam kajian ini. Sisihan ralat relatif (r.s.d) ialah 2.2% bagi kepekatan Al(III) 1.0 μg mL-1. Kesan penambahan ion lain terhadap kompleks Al(III)-morin turut dijalankan dan didapati ion Cu(II), Zn(II) dan Pb(II) memberi gangguan yang lebih berbanding ion-ion lain.
The effect of testosteron on Ascaris suum worm load and larval growth were studied. The results revealed that the effect of testosterone on A. suum infection was dose dependent. Administration of 0.5 mg testosterone propionate (TP) for 18 days significantly increased the mice susceptibility to A. suum infection (66.2 ± 11.15 larvae) (mean ± S.E.) when compared to the control. Higher dosage of testosterone (1.0, 2.5 or 5.0 mg TP) did not show any significant effect. The present experiment also showed that administration of testosterone (0.5 mg TP) for 7 days increased the host susceptibility (86.1 ± 5.86 larvae) to A. suum infection compared to the control (14.6 ± 1.71 larvae) (P < 0.001). Similar results were found when the hormone was administered for 14 and 28 days. On the contrary, when gonadectomised mice were given 0.5 mg TP, the level of susceptibility increased (P < 0.001). It is believed that testosterone indirectly influence the parasitic infection through its effect on the lymphoid organs.
Kesan testosteron terhadap bebanan dan pertumbuhan larva Ascaris suum telah dikaji. Hasil kajian menunjukkan bahawa pengaruh testosteron terhadap infeksi A. suum adalah bergantung kepada takaran hormon yang diberikan. Didapati hanya takaran 0.5 mg testosteron propionat (TP) yang diberikan selama 18 hari meninggikan kerentanan mencit (66.2 ± 11.15 larva) (min ± S.E.) terhadap infeksi parasit jika dibandingkan dengan kawalan (38.0 ± 7.13 larva) (P>0.05). Takaran testosteron yang lebih tinggi (1.0, 2.5 atau 5.0 mg TP) tidak menunjukkan kesan yang jelas. Hasil percubaan juga menunjukkan bahawa pemberian hormon (0.5 mg TP) selama 7 hari boleh meningkatkan kerentanan perumah (86.1 ± 5.86 larva) terhadap infeksi A. Summ. Perbandingan dengan kawalan (14.6 ± 1.71 larva) dan menunjukkan perbezaan yang nyata pada P < 0.001. Begitujuga dengan pemberian hormon selama 14 dan 28 hari. Sebaliknya gonadektomi telah mengurangkan kerentanan mencit terhadap infeksi A. suum. Walau bagaimanapun, kesan sebaliknya didapati apabila mencit yang gonadektomi itu diberi suntikan 0.5 mg TP (P < 0.001). Hormon testosteron dipercayai mempengaruhi corak infeksi parasit secara tidak langsung dengan mempengaruhi perkembangan organ-organ limfoid.
Macrobrachium lanchesteri dewasa telah didedahkan selama empat hari di dalam makmal kepada satu siri kepekatan logam kuprum (Cu) dan nikel (Ni). Masa kematian median (LT50) dan kepekatan kematian median (LC50) dikira berdasarkan data kematian yang diperolehi. Di akhir hari yang ke-4, udang yang masih hidup digunakan untuk penentuan biopemekatan logam. Nilai LT50 dan LC50 didapati meningkat dengan pengurangan kepekatan dan masa pendedahan bagi kedua-dua logam (Cu dan Ni). Nilai LC50 untuk 24, 48 dan 96 jam bagi Cu masing-masing adalah 261.6, 171.6 dan 32.3 μg/L dan bagi Ni 30786.3, 28534.7 dan 8056.6 μg/L. Biopemekatan logam Cu dan Ni oleh M. lanchesteri meningkat dengan peningkatan kepekatan pendedahan dan logam Cu didapati lebih toksik terhadap M. lanchesteri berbanding logam Ni.
This study was aimed to characterize the rejection of oil emulsion by two tubular surface filters, namely 13 μm slots and 4 μm circular pores. A 17 mm helix was incorporated inside the filters to increase the wall shear stress. Rejection of oil, throughputs and flux decay were measured at varying shear stresses (Rw) and transmembrane pressures (TMP). The results showed that the13 μm slots produced a fairly good oil rejection of 22 μm at Rw=0.26 Pa and TMP=6.9 kPa, while the circular pores gave the rejection of 14.4 μm at Rw=0.21 Pa and TMP=34.5 kPa. The results suggested that the circular pores filter could achieve a better oil retention under lower TMP, while the slots filter could be satisfactorily operated under moderate shear stress and low TMP. The increase of TMP offered poor oil rejection by both filters and this was also true for slots-helix configuration.
We studied the clusters of GaAs by using the density functional theory simulation to optimize the structure. We determined the binding energy, bond lengths, Fermi energy and vibrational frequencies for all of the clusters. We use the Raman data of nanowires of GaAs to compare our calculated values with the experimental values of the vibrational frequencies. The nanowire of GaAs gives a Raman line at 256 cm-1 whereas in the bipyramidal Ga2As3 the calculated value is 256.33 cm-1. Similarly 285 cm-1 found in the experimental Raman data agrees with 286.21 cm-1 found in the values calculated for Ga2As2 (linear) showing that linear bonds occur in the nanowire. The GaAs is found in two structures zinc-blend as well as wurtzite structures. In the nanowire mixed structures as well as clusters are formed.
This article concerns with a mixed convection peristaltic flow of an electrically conducting fluid in an inclined asymmetric channel. Analysis has been carried out in the presence of Joule heating. The fluid viscosity and thermal conductivity are assumed to vary as a linear function of temperature. A nonlinear coupled governing system is computed. Numerical results were presented for the velocity, pressure gradient, temperature and streamlines. Heat transfer rate at the wall is computed and analyzed. Graphs reflecting the contributions of embedded parameters were discussed.