Cyclopentyl Trisilanol Silsesquioxanes – Modified Natural Rubber (CpSSQ(OH)3 – ENR-50) Nanocomposite In The Presence Of Tin (II) Chloride Dihydrate

A nanocomposite comprising cyclopentyl trisilanol silsesquioxanes (CpSSQ(OH)3) and 50% epoxidized natural rubber (ENR-50) was prepared at reflux temperature with Tin (II) chloride dihydrate (SnCl2.2H2O) as catalyst. SnCl2.2H2O was found to be an affective catalyst to promote ring opening in ENR-50 and tailored it to CpSSQ(OH)3 via chemical reaction. The generation of carbonyl functional groups arising from epoxide ring opening can be clearly seen in FTIR spectra. 1H and 29Si NMR analyses further proved that the incorporation of CpSSQ(OH)3 in ENR-50 occured. TGA studies showed a degradation temperature with 10% weight decreased and DSC thermogram indicates a single Tg. Single peak in XRD diffractogram at 2-Theta angle further confirmed the surface modification

Dissipation of chlorpyrifos in a Malaysian agricultural soil: a comparison between a field experiment and simulation by the VARLEACH and PERSIST models

A comparison of the dissipation of chlorpyrifos in a Malaysian agricultural soil was undertaken using data from a field experiment and simulation by the PERSIST model. The study was carried out at an oil palm estate located close to the Kuala Lumpur International Airport (KLIA), Sepang, Selangor (for field experiment). The plots were treated with chlorpyrifos at the manufacturer’s recommended dosage. Soil samples were collected according to the sampling schedule at intervals of 0, 1, 3, 7, 14, 21, 30, 60 and 90 days. Residues of chlorpyrifos in soil from the field trial were analyzed in the laboratory. Simulation of chlorpyrifos leaching and persistency was done using two computer-run software VARLEACH and PERSIST. Generally, predicted data for chlorpyrifos residue obtained using the VARLEACH and PERSIST models was found to be well matched with the observed data from the field trial. The PERSIST Prediction for chlorpyrifos residue in soils planted with oil palm trees was found to be accurate and conformed to the results observed in the field trial

Flowering pattern and reproductive efficiency in mungbean.

A large proportion of flowers abort during development due to vascular tissue limitation in the distal part of rachis resulting in lower yield in mungbean [Vigna radiata (L.) Wilczek]. Flowering pattern and its relationships with pod retention, reproductive efficiency and yields in 10 local mungbean genotypes were assessed at Mymensingh, Bangladesh in two consecutive years of 2006 and 2007. The number and pattern of flower production, pod retention and reproductive efficiency (RE, percent pod set to opened flowers) varied among the genotypes. Results revealed that the genotypes, which produced higher number of flowers within a shorter period (10-15 days) after commencement of flowering also produced higher yields, attributed from higher number of flowers and pods. In contrast, low yielding genotypes showed reverse trends. However, low yielding genotypes had higher RE than high yielding ones. It further revealed that the genotype with early-formed flowers had higher podset and retention capacity than later-formed ones. The implication of relationships between flower production and RE for mungbean seed yield is also discussed

Camel in Sudan: future prospects

According to FAO statistics, camel population in Sudan ranks the second in the world after Somalia with 4.5 millions heads. This population is quite important while the camel production appears, at least officially, very low. With a meat production of 49,880 tons and a milk production of 120,000 tons, camel production is far away from the potential. Even if these data did not cover the entire reality, it is obvious that camel production in Sudan is insufficiently valorized. Meat from young camels has been reported to be comparable in taste and texture to beef. Inspite of the increase in local camel meat consumption to 63,000 tons in 2009, yet camel meat is common in some parts of the country and milk consumption under gariss form is popular in rural areas where camel is generally reared. Camel diseases are the major constrains of production such as trypanosomiasis and mastitis. The research has to push in that way in order to innovate camel meat and milk sector. The modernization of meat and milk processing could be the motor for the improvement of camel production. Both in terms of research and of development, the identification of the main constraints for the camel sector is the way to propose a fruitful strategy. (Résumé d'auteur

The Suaineadh Project : a stepping stone towards the deployment of large flexible structures in space

The Suaineadh project aims at testing the controlled deployment and stabilization of space web. The deployment system is based on a simple yet ingenious control of the centrifugal force that will pull each of the four daughters sections apart. The four daughters are attached onto the four corners of a square web, and will be released from their initial stowed configuration attached to a central hub. Enclosed in the central hub is a specifically designed spinning reaction wheel that controls the rotational speed with a closed loop control fed by measurements from an onboard inertial measurement sensor. Five other such sensors located within the web and central hub provide information on the surface curvature of the web, and progression of the deployment. Suaineadh is currently at an advanced stage of development: all the components are manufactured with the subsystems integrated and are presently awaiting full integration and testing. This paper will present the current status of the Suaineadh project and the results of the most recent set of tests. In particular, the paper will cover the overall mechanical design of the system, the electrical and sensor assemblies, the communication and power systems and the spinning wheel with its control system