Physical properties of cutlet-clay ceramic

A series of ceramic based on (x) cullet-(l00-x) clay has successfully been made by slip casting followed by sintering at 800°C. The sample density has been determined using the Archimedes method while their hardness by the Vickers Hardness Test. Meanwhile, the thermal shrinkage has been measured at 900°C. It is found that the density is in the range of 2.03–2.27gem-3, increases as the amount of cullet is increased. Meanwhile their hardness up to 0.38 GPa can easily be obtained. The thermal shrinkage is found to be 2.9–11.9%, increases with the increasing of cullet content up to 60 wt%

Mechanical and Biodegradable Properties of Hydroxyapatite Coated Magnesium Deposited by Cold Spray

Proses semburan sejuk yang mudah dan telah diubahsuai digunakan untuk menyalut serbuk hidrosiapatit ke atas substrat magnesium tulen yang dipanaskan kepada 350°C atau 550°C dan dihaluskan permukaan samada 240 atau 2000 gred kekasaran dengan jarak ‘standoff’ 20 mm atau 40 mm. Prosedur ini diulang lima dan sepuluh kali. Satu reka bentuk faktorial pecahan (24-1) telah digunakan untuk menjelaskan faktor-faktor proses yang memberi kesan kepada ketebalan, kekuatan dan modulus elastik sampel. Analisis kaedah tindihan digunakan untuk menentukan nilai domain yang optimum. Kemudian, kaedah kecuraman digunakan untuk mengesah dan memindahkan nilai domain yang optimum. Sifat mekanik yang maksimum telah diperolehi pada jarak 30mm, gred kekasaran permukaan Ra=0.14 dan 460°C suhu pemanasan substrat yang menghasilkan salutan optimum dengan ketebalan 49.77μm, 462.61 MPa kekuatan dan 45.69 GPa modulus elastik. Lapisan hidroksiapatit tidak menunjukkan perubahan fasa pada suhu 550°C. Daya mikroskop atom menunjukkan topografi lapisan seragam dan mikroskop imbasan elektron menunjukkan ikatan yang baik antara lapisan bersalut dan substrat. Kajian biodegradasi menunjukkan bahawa lapisan apatit tulang yang terbentuk di atas permukaan lapisan selepas 24 jam boleh menggalakkan ikatan tulang dengan tisu hidup dan meningkatkan jangka hayat lapisan. Kajian kehilangan berat menunjukkan bioaktiviti bagi sampel bersalut lebih baik berbanding dengan sampel tidak bersalut. Ujian lekatan mendedahkan bahawa pengurangan kekuatan ikatan datang dari pembubaran lapisan kimia yang berterusan. Selepas 24 jam rendaman, kekuatan ikatan adalah 40 MPa. Ujian percepatan kakisan menunjukkan bahawa lapisan hidroksiapatit melindungi dan mencegah magnesium daripada kakisan dalam persekitaran mengakis. _________________________________________________________________________________________________________________________ A simple and modified cold spray process was developed in which hydroxyapatite powder was coated onto pure magnesium substrates preheated to 350°C or 550°C and ground to either 240 grit or 2000 grit surface roughness, with standoff distances of 20 mm or 40 mm. The procedure was repeated five and ten times. A fractional factorial design (24-1) was applied to elucidate the process factors that significantly affected the thickness, nanohardness and elastic modulus of the coating sample. The overlaid method analysis was employed to determine trade off optimal values from multiple responses. Then, steepest method was used to reconfirm and relocate the optimal domain. The maximum mechanical properties of the coating were determined at 30mm standoff distance, surface roughness Ra=0.14μ and 460°C substrate heating temperature which accommodate the optimum coating of 49.77μm thickness, 462.61 MPa nanohardness and 45.69 GPa elastic modulus. The hydroxyapatite coatings did not show any phase changes at 550°C. Atomic force microscopy revealed a uniform coating topography and scanning electron microscopy revealed good bonding between the coated layers and the substrates. The biodegradable study suggested that bone-like apatite layer formed on the surface of the coatings at 2 hours may promote bone bonding with living tissues and increase the longevity of coatings. The mass loss experiment concluded that coated sample shows a better bioactivity compared to uncoated sample. The adhesion test revealed that reduction of bond strength comes mostly from the continuation of chemical dissolution of coatings. After 24 hours of immersion, the bond strength was 40 MPa which satisfied the requirement for bioimplant application. The accelerated corrosion test concluded that the hydroxyapatite coating remarkably protects and prevent magnesium from corrosion in the corrosive environment

Keberkesanan Baja Kalsium dan Pengairan Terhadap Kandungan Kalsium dalam Tisu Tanaman Mangga (Mangifera Indica, L) Pada Tanah Berkapur

Satu penyelidikan ladang telah dijalankan untuk menilai keberkesanan baja kalsium dan pengairan terhadap kandungan kalsium dalam tisu tanaman mangga (Mangifera indica, L) dan kejadian buah reput dalam mangga (BRDM) pada tanah berkapur di mana dijalankan juga penilaian dan pengkelasan tanah (mengikut Sistem Jabatan Pertanian Malaysia dan Pengkelasan Keupayaan Kesuburan). Dua kadar pengairan [tanpa pengairan (T) dan pengairan (A)] x tiga sumber baja Ca [tanpa baja Ca (CO), baja Ca(N03h (CN) dan baja Biomin Ca (CF)] berfaktorial disusun menggunakan Rekabentuk Rawak Blok Lengkap dengan empat replikasi. Pemeriksaan dan penilaian tanah berkapur [Bukit Bintang Sederhana (BBS), Bukit Bintang Dalam (BBD) dan Bukit Bintang Cetek (BBC)] menunjukkan bahawa tanah ini berlom dengan kandungan lempung di antara 18-35% dan kelodak > 30%. Kadar infiltrasi yang rendah (0. 14-1.30 em jam-I). Tanah ini juga berpH tinggi (7.23-8.44) dan kandungan karbon at > 50 g kg-I. Manakala kedalaman tanah ke lapisan padat berbeza-beza di mana BBS adalah 50-100 em, BBD adalah > 100 em dan BBC <50 em. Kelas kesesuaian tanah BBS adalah 3t(ed), BBD adalah 3t(d) dan BBC adalah 5eR(td). Kelas keupayaan kesuburan tanah BBS dan BBD adalah Ldb dan BBC adalah L'L"db. Tanah BBS dan BBD sesuai untuk kebanyakan tanaman manakala BBC terhad kepada tanaman yang berakar eetek sahaja

Salinity triggers proline sysnthesis in peanut leaves

To investigate the magnitude of proline accumulation under different salinity levels, a salinity-imposed experiment was conducted. The peanut seedlings were cultured hydroponically for 7 days before imposing salinity and then grown further for another 7 days under salinity-loaded condition. Results showed that shoot dry matter, relative water content, chlorophyll and K+ decreased significantly with increasing salinity. In contrast, Na+, hydrogen peroxide and proline increased with increasing salinity level. Free proline content increased abruptly at medium and high salinity levels. Interestingly, the lowest level of dry matter (an indicator of tolerance/sensitivity) accompanied by the highest accumulation of proline at 200 mM NaCl puts a question mark on the well-documented role of proline in relation to salinity tolerance. The underlying mechanism is discussed in detail in the current study

World Distribution of Heterobostrycus aequalis Waterhouse (Coleoptera: Bostrychidae).

Heterobostrychus aequalis is a major pest of seasoned hardwood. It attacks many timber and wood from other plant species and caused damage to a broad range of wood products. Their attacks are confined to starch-rich sapwood and often unsuspected until the emergence hole and frass is produced. The repeated introduction of this pest into new areas indicates that it is poorly inspected and ignored. In some cases, this species succeed in establishing its population in the wild. Hence, by providing the world wide distribution of this pest could be the pioneer step in developing better prevention, monitoring, quarantine and control programmes. From the review, it was found that H. aequalis distribute dominantly in tropical and sub-tropical areas. It is widely distributed in Asia, particularly Southeast Asia to Oceania, some parts of Africa, Central America and Caribbean region. The distribution map derived indicates the limits of distribution for H. aequalis to be 40° north and south of the equator. The recent reports and records showed that this pest is potentially becoming a high-risk pest and can establish its population whenever the condition is favourable

Planting time and mulching effect on onion development and seed production

A field experiment was conducted to evaluate effects of planting time and mulches on bulb growth and seed production of onion (Allium cepa L.) cv. Taherpuri. Planting time and mulches had significant influence on almost all parameters studied. Onion planted on 21 November had better agronomic traits contributing towards yield formation. Growth and seed production was accelerated by black polythene. Seed yield (460.81 kgha-1) was highest in the plots planted on 21 Nov. Seed yield was 529.06 kgha-1 where black polythene mulch was used

Leaf area estimation by linear regression modles for pigenonpea (Cajanus Cajan (L.) Millsp.)

Leaflet length (L) and breadth (B), fresh (LFwt) and dry weights (LDwt) of leaves of 50 samples (500 leaves, 10 in each sample) were used in the prediction model to estimate the leaf area (LA) in pigeonpea (Cajanus cajan cajan (L.) Millsp.). Two of the fifteen linear regression models, appeared more suitable for ease of measurement. These were LA = -17.784 + 6.823 L (Model-1) and LA = 0.5855 + 67.583 LFwt (Model-10). These regression models showed linear relationship when actual leaf area was plotted against predicted one in another 30 leaf samples (300 leaves, 10 in each sample). Moreover, models’ selection indices had high predictive ability represented by high R2 value with minimum error (low means square error and smaller percentage deviation). The selected models appeared unsophisticated but accurate, easy and rapid which can be used for estimation of leaf area of pigeonpea (Morphotype ‘Bogra’)

A study on the determinants of saving in Malaysia / Nurul Wahidah Md Razi

The rapid demographic shift in Malaysia is expected to raise both micro and macro-economic issues. On the microeconomic front, health care, housing, and other related services for the purpose of improving the welfare of the elderly need to be addressed. In addition, macroeconomic issues related to saving, labor productivity, and capital flows also need to receive attention. Due to the inadequacy of recent and comprehensive data and information regarding the behavior of household savers through time, the study designed to increase savings interest. So, this research is to study about what actually the determinants that influences saving behavior in Malaysia. It conducts to determine is there relationship between of income, rate of return, inflation and consumption on saving in Malaysia

Genotypic and Seasonal Variation in Plant Development and Yield Attributes in Tomato (Lycopersicon esculentum Mill.) Cultivars

Morphological attributes and yield of eight genotypes of tomato namely, J-5, Binatomato-5, BARItomato-7, CLN-2026, CLN-2366, CLN-2413, CLN-2418 and CLN-2443 were studied over three seasons. Effects of seasonal and genotypic variations and their combination on plant height, number of primary branches per plant, number of flower clusters per plant, number of fruit clusters per plant, number of fruits per plant, individual fruit weight, fruit yield were significant. Fruit yield and almost all the morphological attributes of tomato genotypes were at peak in winter followed by pre-winter and summer season. Over three seasons, the genotype CLN-2413 produced the highest fruit yield followed by BARI tomato-7 producing the tallest plants with maximum number of primary branches and the highest number of fruits per plant. The genotypes Binatomato-5, CLN-2026 and CLN-2418 ranked 3rd and CLN-2366 and CLN-2443 ranked 4th with respect to yield performance. The genotype J-5 produced the lowest number of fruits per plant and fruit yield. In winter, fruits number and yield were highest in CLN-2413 while BARI tomato-7 carried the statistically same rank

CH4 and CO2 detection by using carbon nanotube-based sensors

This research was carried out to investigate the effect of gas adsorption towards the electrical resistance of carbon nanotubes (CNTs) thin film. CNTs were synthesized by Floating Catalyst Chemical Vapor Deposition (FC-CVD) method on quartz substrate at 950°C under methane gas flow rate of 150 Standard Cubic Centimeters per Minute (SCCM). Then, the electrical resistance of CNTs was measured by exposing the sensors to CO2 and CH4 gases operating at room temperature. The sensors showed high responses to the gaseous molecules. In the same experimental conditions, the recovery of the sensors was different for CO2 and CH4. It was also observed that the CNTs device behaves as a p-type semiconductor when exposed to gaseous molecules. The fabrication process was relatively simple and did not require special techniques