Optimization of oil heat treatment process to enhance rubberwood properties using response surface methodology

Rubberwood is an eco-friendly wood. Natural rubber is considered as the excellent agricultural product and it was utilized in many industries. The natural durability is very low in rubberwood. In dry as well as in green condition, it can be affected by wood borers and fungus. The objectives of this study are to determine the effect of resistance to white rot fungus, to assess the significant changes on the physical properties, chemical properties and mechanical properties of rubberwood after the heat treatment (172 - 228°C) in palm oil and to optimize the heating variables to enhance the properties of rubberwood treated with oil using response surface methodology. The colour of oil heattreated rubberwood becomes uniformly darker. Hydrophobicity, dimensional stability and fungal resistance were improved by the heat treatment with respect to increase in treatment temperature. However, the mechanical properties of treated rubberwood were reduced compared to the untreated wood. The treatment resulted in changes to the wood chemical constituents, mainly the degradation of hemicelluloses which is believed to be principal reason for alterations in wood properties. The oil heat treatment reduced the chemical constituents by 11.7 % in total in the rubberwood. The depolymerization of hemicellulose results in reduction on bending strength of wood. The maximum reduction in Modulus of Rupture, Modulus of Elasticity, Compression and Shear were approximately 47%, 8%, 21% and 33% respectively compared to the control specimen. This study shows that there is some reduction in density and equilibrium moisture content and positive high in moisture excluding efficiency values. The density of rubberwood was decreased gradually from 629 kgm-3 (untreated) to about 591 kgm-3 (at 228°C/180min). The Equilibrium Moisture Content also decreased from 12.42 % to 7.97 % (at 228°C/180min). The density reduction was probably due to the hemicelluloses and cellulose degradation. The higher moisture excluding efficiency value indicated that the wood is stable and excludes water after oil heat treatment process. The treated wood has moisture excluding efficiency value in the range between 28-50% depending upon the treatment temperature and time. The fungal resistance effect on the treated rubberwood was examined by exposing the wood to white rot fungi (Pycnoporus sanguineus) for 12 weeks and the weight loss was determined. The samples were tested at 13 different treatment conditions. Among those conditions, the lowest weight loss (8.23 %) was observed at 228°C and 180 min, with the decay by Pycnoporus sanguineus for rubberwood species. This research helps in improving various properties of rubberwood and biological durability by oil heat treatment process. Thus with the outcome of this research, the optimized heat treatment conditions could be suggested by the response surface methodology models to enhance the quality of rubberwood

Radio frequency interference: The study of rain effect on radio signal attenuation = [Interferens frekuensi radio: Kajian kesan hujan pada pengecilan isyarat radio]

The intensity of radio waves received by radio telescopes is always not subject to human control. In the millimetre band, the propagation of the electromagnetic waves is severely affected by rain rate, dust particle size and drop size in the terms of attenuation, noise and depolarization. At the frequency above 10 GHz, the absorption and scattering by rain cause a reduction in the transmitted signal amplitude which will lead to the reducing of the availability, reliability and performance on the communications link. In this study, the rain effect on radio signal has been investigated. Spectrum analyzer and weather stations were used to obtain the RFI level and rain rate data respectively. The radio frequency interference (RFI) pattern due to rain factor was determined. This will benefit radio astronomer in managing sites for radio observation for radio astronomy purposes

Phytochemical, Analgesic And Acute Toxicity Study Of Jatropha Curcus Root

Jatropha curcus Linn. is a multipurpose plant in the Euphorbiaceae family. The ethnomedical practice in West Africa showed the application of Jatropha curcus leaves in different forms to cure various ailments like fever, mouth infections, jaundice, guinea worm sores and joint rheumatism. The roots of J. curcus have been used as a decoction for bleeding gums, toothache, eczema, ringworm, and scabies and to cure dysentery. This study therefore assessed the phytochemical and analgesic properties of Jatropha curcus root. The acetic acid induced writhing test in mice was used to study the analgesic effect. The analgesic activity on methanol extract of the root (25mg/kg, 50mg/kg and 100 mg/kg) in the writhing test showed significant reduction of pain induced by acetic acid with the 50mg/kg being more potent. Phytochemical results of the three solvent extracts showed presence of tannins, triterpenes, alkaloids, carbohydrate and flavonoids. The quantitative phytochemical analysis showed that alkaloids (94.0 mg/g) was the highest phytochemical detected in the root while the lowest was saponins and phenols (23.0 mg/g). The results of this investigation may be useful for deriving doses that are safe for human consumption medicinally of Jatropha curcus root. Collectively, this study provides scientific data for the use of Jatropha curcus in the treatment of pains and contribute to the analgesic knowledge of this species. Further study should be carried oot o find out the mechanism of its action and also to isolate, identify and characterize the active agent responsible for these effects in this plant

Analgesic and anti-inflammatory activities of the n-butanol fraction of Vernonia glaberrima

The n-butanol leaf fraction of Vernonia glaberrima was evaluated for its toxicity, analgesic and anti-inflammatory effects. The leaves of V. glaberrima were collected, identified and extracted with methanol using maceration method and the resulting crude methanol extract was then partitioned using different solvents of increasing polarity (hexane, chloroform, ethyl acetate and n-butanol respectively). Preliminary phytochemical screening was conducted on the n-butanol fraction (BF) using standard procedures. The median lethal dose (LD50) of the fraction was determined using Lorke’s method and the analgesic effect was evaluated using acetic acid-induced writhing test in mice, while the anti-inflammatory activity was assessed using carrageenan-induced paw oedema in rats. Secondary metabolites including saponins, tannins, alkaloids, glycosides and flavonoids were found in the fraction. The LD50 of the fraction was 2154 mg/kg indicating the fraction to be moderately toxic. The fraction at 150 mg/kg exhibited 77.6 % inhibition of writhes, higher than the standard drug, piroxicam (10 mg/kg) which had 53.7 % inhibition. The n-butanol fraction at 150 and 250 mg/kg significantly inhibited the carrageenan-induced paw oedema at the 2nd and 4th hour, respectively, while there was no significant inhibition at 500 mg/kg of the fraction. The standard drug was only able to inhibit oedema at the 1st hour. The results showed the n-butanol fraction of V. glaberrima to possess significant analgesic and anti-inflammatory activities thereby validating its traditional use in the treatment of pain and inflammation

Pharmacognostic, elemental and acute toxicity study of Fadogia agrestis root

An aphrodisiac is a type of food or drink that has the effect of making those who eat or drink it more aroused in a sexual way. Aphrodisiacs can be categorized according to their mode of action into three groups: substances that increase libido (i.e. sexual arousal), substances that increase sexual potency (i.e. effectiveness of erection) and substances that increase sexual pleasure. Fadogia agrestis (Schweing. Ex. Hiern), Rubiacea (Hausa: Bakin gagai; English name: Black aphrodisiac) is an erect shrub 1-3 feets high. Fadogia agrestis is a medicinal plant widely used for its reported antibacterial and aphrodisiac activities. The aim of this work is to carry out pharmacognostic standardization and safety profile on Fadogia agrestis root. Chemomicroscopic, physicochemical, elemental, phytochemical and acute toxicity studies were carried out using standard methods. The results obtained also provided scientific basis for the use of in folklore medicine. Chemomicroscopic characters present include; cellulosecell wall, lignified cell wall, tannins, starch, calcium oxalate and cutin. The physicochemical parameters evaluated include: moisture content (7.0%), total ash (10.5%), water soluble ash (4.1%), acid insoluble ash (8.33%), ethanol extract (15.0%), and water extractive value (12.0%). The quantitative phytochemical analysis showed that alkaloids (84.0 mg/g) was the highest phytochemical detected in the stem bark while the lowest was saponins (4.0 mg/g).LD50 of both extracts was above 5000 mg/kg and did not cause mortality in all the tested rats. The results of this investigation may be useful for deriving doses that are safe for human consumption of F. agrestis root.&nbsp