Zinc oxide nanowires (ZnO NWs) have an efficacious place in nanoworld due to their tremendous properties and applications. In the present work, structural and electrical properties of ZnO NWs have been modified by carbon (C) ions- beam irradiation. With ion-beam energy of 0.8MeV, the physical behaviors of NWs have been studied under different doses from 1×1012 to 1×1014 ions/cm2. The microstructural and Raman spectroscopy studies showed that the wurtzite crystal structure of the ZnO NWs has been changed into disordered amorphous one under high C ion doses. Whereas, the XRD results showed that Zn nanoparticles are fabricated at high C ion-beam irradiation on ZnO NWs. Scanning electron microscopy (SEM) depicts the formation of cross junctions and parallel junctions between ZnO NWs after C ion irradiation. DC conductivity measurements have confirmed that the conductivity of NWs decreases with increase in C ion doses. It is concluded that the lattice defects significantly contribute to decrease in the conductivity of ZnO NWs.
In order to optimize the extraction of gelatin from pangasius catfish skin, a response surface method (RSM) involving a Central Composite Design (CCD) was applied. Four variables, namely NaOH concentration (0-0.3 N), acetic acid concentration (0.025-0.125 N), extraction time (2-4 h) and extraction temperature (40-80°C) were selected as independent variables for the optimization using RSM. The dependent variable was calculated by hydroxyproline recovery. The optimum conditions for extraction were produced by a pre-treatment of 0.2 N NaOH and 0.1 N acetic acid along with hot water extraction at 63.7°C for 2.41 h. The results showed that the predicted response by RSM (68.53%) closely matched the experimental response of 68.16%. The results indicated that the extracted gelatin possessed high gel strength (438 g) and high content of imino acid (proline and hydroxyproline) (18.01%) with a viscosity of 4.67 mPa s. The results showed that RSM was a great optimizing tool for extraction of gelatin from pangasius catfish skin. The gelatin was also proven to have significantly (p<0.05) higher quality of physicochemical properties than those from bovine skin gelatin.
The data used in this study consisted of milk yield (kg) taken at approximately fortnightly intervals from Gir x Friesian crossbred dairy cattle raised at Institut Haiwan Kluang, Malaysia. The data were first edited, smoothed and then fitted with mono-, di- and triphasic logistic functions. In general, parameter estimates for the first lactation were reasonable. However, for the second lactation the estimates were erratic and unreasonable because this was the atypical lactation for which the multiphasic functions were obviously unsuitable. Residual mean squares for the di- and triphasic functions of the first lactation were very similar (0.0002 and 0.0004, respectively) and smaller for the monophasic function (0.0894). For the second lactation, residual mean squares for the triphasic function (0.001) was the lowest compared to those for the mono- and diphasic functions (0.0345 and 0.0315). For the first lactation, the monophasic function did not fit the data well because it had large residuals. The di- and triphasic functions were almost similar in fitting the lactation and had low residuals. For the second lactation, both the mono- and diphasic functions did not fit the data very well and had rather large residuals. The triphasic function was the most fitting and had small residuals. Derived functions were generally lower for the first lactation than the second lactation: initial milk yields (4.88 to 6.0 kg versus 9.9 to 11.8 kg); peak milk yields (5.8 to 9.6 kg versus 12.8 to 15.7 kg) and 305-day milk yields (1147.7 to 1328.6 kg versus 1687.4 to 2296.1 kg).
Siliceous mesoporous molecular sieve (Si-MCM-41) material with highly ordered hexagonal pore arrangement was synthesized at 373 K for 8-days duration by hydrothermal method, dried at 393 K and calcined at 823 K in N2 atmosphere. The calcined Si-MCM-41 was later functionalized with 10-50 wt. % monoethanolamine (MEA) by impregnation method and dried in vacuum at 343 K. The MEA-Si-MCM-41 samples were characterized for their physicochemical properties with FTIR, XRD, TGA, HRTEM, FESEM, BET and elemental analysis. XRD results showed that the intensity of the characteristic peaks of Si-MCM-41 reduces with increasing loading of MEA indicating that the MEA molecules are loaded in the pores as well as on the surface of Si-MCM-41. The appearance of FTIR peaks corresponding to N-H, C-N and C-H bonds suggested that Si-MCM-41 has been functionalized with MEA. The presence of Si-O-Si peaks in FTIR spectra of MEA-Si-MCM-41 samples indicates that the hexagonal pore arrangement remains intact and this is supported by HRTEM images. FESEM images show that MEA-Si-MCM-41 samples became agglomerated with increase loading of MEA. TGA analyses show that the MEA-Si-MCM-41 samples are thermally stable up to 528 K. N2 adsorption-desorption isotherms show that the textural properties of Si-MCM-41 material slowly change from a mesoporous material to non-porous material as the MEA loading increases due to pore filling effect during functionalization with MEA. Detection of N, C and H by elemental analysis confirms the presence of MEA in MEA-Si-MCM-41 samples.
The design of microring resonators (MRRs) for serial configuration, integrated in the lateral scheme was presented and simulated using 3D electromagnetic simulator based on finite integration technique. The device model is embedded on the high index contrast (HIC) structure of silicon-on-insulator with monomodal cavity for TE-mode polarizations. From the proposed model, we varied the MRRs order, waveguides separation distance and ring radius, in order to evaluate the influence of those parameters on the device performance in terms of loss, free spectral range (FSR) and quality factor (Q-factor). Upon varying the gap distances, it was found that the highest Q-factor value of the proposed design was 1275 obtained at gap separation of 150 nm for ring radius of 6 μm, while the largest FSR was 24 nm. The trade-offs between device compactness, optical bandwidth and Q-factor are also presented.
Biodegradable polymeric films, obtained from chitosan/natural rubber latex (CS/NRL) blends with different compositions, have been prepared by wetting process. The blends were characterized by dynamic mechanical thermal analysis (DMTA) and found that the CS/NRL blends are thermodynamically incompatible. This is evident from the presence of two glass transitions, corresponding to CS and NRL phases in the blend. The mechanical properties of the CS/NRL blends were improved with increasing the amount of chitosan and after surface treatment with sulphuric acid due to the sulfonate ionic interaction. The dielectric properties was determined using Precision LCR meter in the frequency range 75 kHz up to 30 MHz. After CS/NRL surface treatment with sulphuric acid at high content of chitosan showed the highest dielectric constant. The surface properties of the CS/NRL blend films before and after surface treatment were confirmed by atomic force microscopy (AFM), respectively.
Proliferasi tumor filodes tertumpu terutama pada bahagian stroma yang dianggap sebagai komponen neoplastik bagi tumor filodes. Reseptor Estrogen (ER) yang memainkan peranan dalam payudara neoplastik juga terlibat dalam perkembangan tumor filodes. ERβ adalah satu jenis klon ER yang dilaporkan hadir pada stroma tumor payudara manakala pengekspresan aktin otot licin (SMA) di stroma dapat membandingkan gred histologi tumor filodes. Kami membandingkan pengekspresan ERβ dengan SMA pada komponen stroma tumor filodes menggunakan teknik tisu mikroarai (TMA). TMA dibentuk ke atas 77 kes tumor filodes (46 benigna, 17 pinggiran dan 14 malignan) menggunakan jarum berdiameter 0.6 mm (Alphelys Plaisir, Perancis) dan pewarnaan imunohistokimia dijalankan menggunakan penanda molekul ERβ dan SMA. Tumor filodes kerap hadir pada wanita berusia lebih daripada 40 tahun dengan tumor filodes benigna menunjukkan median umur pesakit paling rendah (p=0.017). Ekspresi ERβ dalam komponen stroma meningkat dengan gred histologi tumor. Sementara SMA menunjukkan ekspresi pada 62.8, 41.2 dan 57.1%, masing-masing bagi tumor filodes benigna, pinggiran dan malignan. Kedua-dua ERβ (p=0.024) dan SMA lebih cenderung hadir pada wanita ≥40 tahun. Kajian menunjukkan hubungan signifikan antara ko-pengekspresan ERβ dan SMA (p=0.047) dan 65.5% daripadanya adalah wanita berumur lebih daripada 40 tahun. Ekspresi SMA yang tinggi pada stroma tumor filodes benigna mungkin menunjukkan potensi proliferasi tumor ini untuk menjadi malignan. Ekspresi tinggi ERβ dengan tumor filodes malignan dan hubungannya dengan SMA mencadangkan ko-pengekspresan kedua-dua penanda molekul ini mungkin berperanan dalam tumorigenesis stroma tumor filodes.
The experiment was conducted to determine the feed intake and body weight (BW) change of Boer goats supplemented with a commercial concentrate pellet and combinations of concentrate and soya waste. Twelve male goats were divided into three groups. Each group was randomly allocated to each of the three treatment diets: Napier grass (Pennisetum purpureum) ad libitum and concentrate pellet at rate of 2.0% of BW, daily (T1); Napier grass ad libitum and concentrate pellet at rate of 1.4% of BW and soya waste at rate of 0.5% of BW, daily (T2) and Napier grass ad libitum and concentrate pellet at rate of 0.9% of BW and soya waste at rate of 0.5% of BW, daily (T3). The results indicated that supplementation of concentrate pellet together with soya waste (T2 or T3) significantly (p<0.05) decreased intakes of grass dry matter (DM), total DM and total crude protein compared to the solely concentrate pellet group (T1). However, BW gain was significantly (p<0.05) higher in T2 treatment compared with the T1 or T3 treatments. Supplementation of concentrate pellet with soya waste (T2 or T3) significantly (p<0.05) improved the feed conversion efficiency and reduced the feed cost of goats compared with solely concentrate pellet group (T1). The results indicated that grass intake and feed cost can be reduced by replacing concentrate pellet with soya waste in the diet of goats where soya waste is available.
Lesser known wood species (LKS) have the potentials to become alternative sources of timber supply for wood based industries if their properties can be improved. In this study, Mahang wood (Macaranga sp.) was impregnated 15% (w/v) low molecular weight phenol formaldehyde (LMWPF) followed by compressing in a hot press at 70, 60 and 50% compression ratios (CR). The treated wood was partially dried in an oven at 65°C until 10% moisture content and subsequently followed by curing at 150°C for 30 min in a hot press. The results showed that the phenolic compreg technique had successfully increased the dimensional stability and mechanical properties of the wood. The polymer retention calculated based on weight gain regardless of compression ratio was approximately 30%. The majority of the properties were improved by the degree of compression in a hot press. Nevertheless, thickness swelling and swelling coefficient increased which were due to spring back effect. As regards to specific strength (strength to density ratio), the compreg wood displayed lower strength and stiffness in lateral direction compared with untreated solid wood. However, the specific compressive strength perpendicular to grain and hardness of the compreg wood were superior than untreated solid wood. The treatment had also changed the wood into highly resistant to fungal decay.
A study was carried out to determine the process parameters and optimization for the hydrolysis of protein precipitate from cockle (Anadara granosa) meat wash water. Precipitation of the protein in the wash water was done using pH manipulation (pH3-8). The precipitate was hydrolyzed using hydrochloric acid (HCl) and optimized for HCl volume, HCl concentration and hydrolysis time using response surface methodology (RSM) based on a central composite rotatable design. Based on the results, hydrolysis of cockle meat wash water precipitate was carried out by precipitation of the wash water at pH4. Optimum condition for the hydrolysis of 2.0 g of cockle meat wash water precipitate was 25 mL of 1 N HCl for 10 h which resulted in nitrogen content (NC) of 0.7% and degree of hydrolysis (DH) of 55%. NC and DH were significantly influenced only by the hydrolysis time.
A distinct element approach has been introduced for simulating the plugging performance of granular lost circulation materials (LCM) in a fracture. This approach solves the fully coupled fracture walls, fluid and particles system in an interactive environment. The effects of the particle shape, size distribution and concentration on the fracture-plugging performance of the granular LCM have been investigated using the three-dimensional particle flow code (PFC3D). The simulated results showed that the irregular granular LCM could plug a fracture width larger than the sieving granulation by single-particle bridging type. The particle size distribution (PSD) of LCM dominates the plugging depth and efficiency in a fracture and there exists an optimum concentration for maximum effect of LCM additives.
Pembentukan-tikso merupakan teknologi baharu untuk menghasilkan produk hampir siap dalam keadaan separa pepejal. Proses ini dapat mengurangkan makropengasingan, keliangan serta memerlukan daya pembentukan yang rendah. Sehingga kini, terdapat beberapa aloi aluminium seperti gred A319, A356 dan A357 digunakan untuk pemprosesan logam separa pepejal. Oleh itu, terdapat permintaan untuk mempelbagaikan aloi aluminium daripada gred yang lain untuk pemprosesan logam separa pepejal. Kajian ini membincangkan tentang permodelan termodinamik untuk meramal perubahan sifat aloi aluminium gred A319 apabila kandungan elemen pengaloian seperti tembaga, mangan dan ferum dipelbagaikan agar memenuhi kriteria pemprosesan logam separa pepejal. Kesemua pengiraan dalam kerja permodelan ini menggunakan perisian komersial ‘Java-based Material Properties’ (JMatPro). Pengiraan termodinamik berdasarkan persamaan ‘Scheil’ digunakan untuk menentukan julat suhu pemejalan (∆T), kepekaan pecahan cecair (dfL/ dT) dan suhu tingkap pemprosesan (∆T30/50). Daripada pengiraan termodinamik, didapati suhu pemejalan aloi yang telah ditingkatkan %bt kandungan tembaga, mangan dan ferum menurun daripada 130 kepada 113°C manakala suhu eutektik meningkat daripada 510 kepada 515°C. Kepekaan pecahan cecair pula berkurangan daripada 0.017 kepada 0.007°C-1 manakala suhu tingkap pemprosesan menurun daripada 26 kepada 24°C. Tindak balas perduaan eutektik pula berlaku antara 30 dan 50% pecahan cecair untuk kesemua kumpulan aloi. Gambarajah fasa digunakan untuk mengetahui fasa sebatian antara logam seperti β-Al5FeSi dan Al2Cu yang terbentuk dalam aloi tersebut. Hasil daripada permodelan termodinamik ini menunjukkan kesesuaian aloi yang dipelbagaikan %bt elemen tembaga, mangan dan ferum digunakan untuk pemprosesan logam separa pepejal.
Calcination temperature greatly influences the total basicity and surface area of catalysts. Investigations were conducted on calcium and niobium (CaO-Nb2O5) mixed oxides catalysts prepared via conventional solid state method (oxides were mixed and ground in agate mortar) and calcined at different temperatures ranging from 300-800oC for 5 h. The catalysts were then characterized by using X-ray diffraction (XRD), CO2 temperature-programmed desorption (TPD- CO2), Brunauer-Emmett-Teller (BET) surface area analyzer and scanning electron microscope (SEM). The formation of Ca(OH)2 and CaCO3 at lower calcination temperatures (< 600oC) reduced the surface area of the catalyst and masked the basic active sites, hence lowered the total basicity of the catalyst. Besides, low surface area and total basicity were observed at higher calcination temperatures (> 600oC), due to sintering of the fine crystals, which promotes cluster agglomeration. Thus, the optimum calcination temperature for CaO/Nb2O5 mixed oxides was 600oC, which produced the largest surface area (7 m2/g) and total basicity (1301 μmol/g). The biodiesel was produced via transesterification of palm oil, methanol and the catalysts calcined at various temperatures. CaO/Nb2O5 mixed oxide calcined at 600oC showed the highest biodiesel conversion (98%) with methanol/oil molar ratio of 12, 3 wt.% of catalyst, a reaction temperature of 65oC and reaction time of 2 h.
The aim of the study was to develop response surface methodology (RSM) models for polymer loading, density, dimensional stability, strength and stiffness of compressed wood of sesenduk (Endospermum diadenum) treated with phenol formaldehyde (PF). Central composite design (CCD) using RSM with three processing parameters was studied in their specific ranges: PF concentration (PC) from 24-40%, pre-curing time (PCT), 3-9 h and compression ratio (CR), 70-90%. The experimental design was analysed and interpreted using the Design Expert Software (Stat Ease version 8) and the responses of 3d plots were built using the same software. Quadratic models in terms of PC, PCT and CR were developed for polymer loading, density, reduction in water absorption and modulus of rupture in static bending. Multiple linear equations were developed for anti-swelling efficiency and modulus of elasticity. The experimental values were in good agreement with predicted ones and the models were highly significant with correlation coefficients between 0.626 and 0.926. PC and CR had significant effects on the responses. The range of PCT used did not significantly affect the responses. It was also found that the improvement of properties ranged from moderately to highly correlated with the polymer loading in the compreg wood.
Nata de coco or bacterial cellulose produced by Acetobacter xylinum is a unique type of biocellulose. It contains more than 90% of water. Dried nata was preferred compared to wet form since it is more convenient and portable with stable properties. Therefore, drying process is necessary in order to produce dried nata de coco. Drying method is a key factor that influenced the properties of dried nata de coco produced. The aim of this study was to investigate the effect of different drying methods on morphology, crystallinity, swelling ability and tensile strength of dried nata de coco. Nata de coco samples were dried using three physical drying methods such as oven, tray dryer or freeze dryer until it achieved 3-5% moisture content. Obviously, the three drying techniques produced web-like structured nata de coco and quite similar crystallinity which was in range between 87 and 89%. Freeze dried sample showed the largest swelling capacity and tensile strength which was found to be 148 MPa. Different drying method gave different properties of nata de coco. Therefore, the present work proposed the most suitable drying method can be utilized based on the properties of end product needed.
The otoliths of sea bass (Lates calcarifer) were sampled from 23 locations in Peninsular Malaysia in order to analyse the Sr/Ca, Mg/Ca and Ba/Ca ratios. This study found that these elements/Ca ratios in sea bass otoliths were correlated with the salinity zone (thalassic series) compared with elements/Ca ratios in ambient water. The contradictory pattern of Sr/ Ca ratios and Ba/Ca ratios in otoliths was found according to salinity zone variations. Thus, oligohaline waters showed the highest Ba/Ca ratios while the highest Sr/Ca ratios were recorded for saline waters. The terrigenous enrichment of Ba in water also affects the Ba content in otoliths. The presence of Mg in otoliths acts as a rival to Ba, thus affecting Mg and Ba deposition. Meanwhile, Ba is the tracer for salinity fluctuations based on the partition coefficient (D) and it shows significant changes. However, the elements in otoliths were found to originate indirectly from the water column. The sequence of the elements/Ca ratios in otoliths and ambient water was Sr/Ca>Mg/Ca>Ba/Ca and Sr/Ca>Ba/Ca>Mg/ Ca, respectively.
Human respiratory syncytial virus (RSV) is an important cause of acute respiratory tract infection in infants and young children. Phylogenetic analysis for RSV in Malaysia has not been reported before. We investigated the genetic features of RSV in respiratory specimens from March to August 2011 with molecular methods. From a total of 130 throat swab and nasopharyngeal aspirate specimens, 54 (41.5%) were positive with RSV, identified by in-house real-time reverse transcriptase polymerase chain reaction (rRT-PCR) assay. Thirty-four out of 54 (63.0%) RSV positive patients were children below two years old and two (1.4%) were adults. Phylogenetic analysis showed 39 isolates were genotype GA5, 13 genotypes GA2, one genotype GA1 and one genotype GA7. The findings indicated four genotypes of RSV circulating in the country and the predominant genotype is GA5.
It is well established the efficacy of orthokeratology (OK) treatment in improving refraction and visual acuity (VA) of low myopic subjects. However, limited data is available on high myopes. The purpose of this study was to investigate the changes of refraction, VA and contrast sensitivity (CS) over time in high myopic school children after 1 week of overnight OK treatment. A total of 19 high myopic school children were fitted with OK lenses. Mean refraction at baseline was -6.29±1.25 DS. Refraction was conducted using cross cylinder method and LogMAR chart. CS was evaluated using Pelli-Robson and FACT charts. All measurements were taken at baseline, 1, 2, 3 and 7 days after overnight OK. Data was analyzed using repeated measures of ANOVA. The results showed that refraction and CS were significantly improved throughout the study period (p<0.05). Significant changes in all parameters were noted after the first overnight treatment. Mean refraction and unaided VA after 7 nights of treatment was -0.64±1.17DS and 0.08±0.29, respectively. The results from Pelli-Robson and FACT charts showed improvement comparable to aided baseline values (p>0.05). This study concludes that overnight OK reduces refraction but does not compromise VA and CS in high myopic children within the study period. Further studies are needed to determine the long term impact of OK treatment on visual functions in a larger sample of high myopic children.
This paper discussed on the effectiveness of BAP and NAA growth hormones on establishment of plant regeneration for selected ornamentals; Agapanthus praecox, Justicia betonica and Celosia cristata. Various explants (leaf, stem, shoot tip and bulb) derived from one-month-old aseptic seedlings of A. praecox and C. cristata, as well as explants from intact plants of J. betonica were utilized to achieve complete plant regeneration of these species. MS medium supplemented with various hormones, with an emphasis on BAP and NAA was tested to obtain direct and indirect regeneration. Both A. praecox (bulbs) and C. cristata (shoots) formed complete plantlets on MS added with 0.5-2.0 mg/L BAP and NAA, while direct regeneration was achieved for J. betonica on MS media containing BAP. Several methods were attempted to acclimatize the regenerants, with A. praecox gave the highest percentage of survival rates (96.67%), followed by J. betonica (80.00%) and C. cristata (75.00%).
Currently, bio-pesticide is relatively harmless to human and environment and thus desirable for its use in the control of insect vectors. Bio-pesticide has been increasingly important in both scale commercial agriculture and small plot, subsistence farming. One of the sources for bio-pesticide is ‘tuba’ plant, known as Derris elliptica. Derris elliptica contains bio-active compounds known as rotenone (C23H33O6) which is harmless to plants, highly toxic to many insects and relatively innocuous to mammals. The study was carried out to investigate the appropriate processing parameters with the aimed to acquire high yield of rotenone (mg) and concentration (mg/mL) of the exhaustive extraction process by evaluating the kinetics of the normal soaking extraction (NSE) method. The raw plants were collected from Kota Johor Lama, Johor and sorted to collect the root. The roots were sorted into 2 types of raw material particles size (mm in diameter) prior to the extraction process. Rotenone from the root part was extracted by using a NSE method at ambient temperature of 27±1oC. Three types of solvents and 2 solvent-to-solid ratios were utilized throughout the extraction process. The extraction was carried out for 50 h and the fractions of the liquid crude extract were collected for each interval time (2 h/mL/fraction) and further cleaned up to remove any fine debris prior to the determination of rotenone content (mg) and its concentration (mg/mL) via reverse-phase high performance liquid chromatography (RP-HPLC). From the kinetics result obtained, it was found that the fine Derris elliptica roots with particles size of 0.5 - 2 mm in diameter and solvent-to-solid ratio of 10 mL/g of acetone solvent system were considered the best processing parameters to procure high yield of rotenone and its concentration.