Determination of Physico-chemical properties of selected tropical timbers in Anambra State, South Eastern Nigeria

The analyses on chemical properties of some tropical timbers have been studied. The physical properties of these timbers varied in the pH(4.26 – 6.85) , moisture content(13%-37%), specific gravity(0.16-0.45), charring temperature (61 – 116o C)and porosity index(1.17-2.08%).Also the solubility behaviors of these timbers were mostly insoluble in hot and cold water, NaOH and ethanol and slightly soluble in concentrated HCl and H2SO4 respectively. The Qualitative results show heavy presence of flavonoids, saponins, tannis, glycosides, steroids and terpenoids in some of the timbers.Quantitative determinations were carried out and results show that the woods contain chemical constituents which are useful to both humans and industries.

Desulphurization Efficiency of Snail Shell on Coal-Groundnut Shell Briquette

The diminishing accessibility of wood fuel and the danger of desertification and deforestation call for interest in the use of alternative energy sources. Herein, we studied the properties of bio-briquettes produced from Onyeama coal in Nigeria and groundnut shell used as the desulphurizer, while cassava starch was used as binder with Snail shell. For effective capturing of Sox, snail shell was added. The ratios of coal to groundnut shell (w/w) in the briquette were 90:10, 80:20, 70:30, 60:40 and 50:50, while 1:1, 1.25:1, 1.5:1, 1.75:1 and 2:1 were used as the ratios of calcium to sulphur (Ca/S) in mole/mole. The briquette was then subjected to some physical characteristics and desulphurization was carried out between 300 to 500°C at an interval of 50°C at an airflow rate of 1.2 L/min for 12 minutes. The results illustrated that 88.1% was the highest desulphurization efficiency with 2:1 Ca/S ratio at 500°C. The results showed that the durability ranged between 88.67 and 98.67, the porosity index ranged between 0.19 to 0.41, while the humidity resistance ranged between 95.15 and 99.15%. The best briquette in terms of durability and relative humidity resistance is briquette made of 90% coal with a Ca/S 1:1 desulphurizer ratio, which is preferred for household and cottage industrial applications. However, the use of a Ca/S desulphurizer in the ratio of Ca/S 2:1 at 500 gave better desulphurization.The introduction of SO2 adsorbent also reduced the SOx emitted to the atmosphere.

Increasing Density and Cement Content in Expansive Soils Stabilization:Conflicting or Complementary Procedures for Reducing Swelling?

Present study makes three contributions to the literature of expansive soils: (i) it proposes equations to predict soil swelling based on dry density and cement content, (ii) it checks the developed general equation by predicting the swelling of different expansive soils from literature and (iii) it designs experiments that investigate factors that have a significant influence on swelling. An experimental programme was carried out to analyse the expansion of bentonite-kaolin-cement blends. Different proportions of bentonite-kaolin, cement content, dry density and moisture content were evaluated. A unique relation of the cement/porosity index was obtained for cement stabilized expansive soils swelling; this index has been used before to portray strength, stiffness and loss of mass of stabilized soils and is now shown to be applicable to describe swelling of expansive soils treated with Portland cement. In the present research, cement content and dry density are seen as conflicting parameters regarding the swelling of expansive soils, since increasing Portland cement amount reduces swelling and increasing density (through compaction) causes higher expansion. A general swelling model was proposed and successfully checked with data from the literature, being able to predict the swelling of expansive soils with different densities, expansive mineral, moisture and cement contents.

Effect of Process Parameters on Anodization of AA7075

The influence of the major process parameters for anodizing AA7075 is investigated to obtain an anodized layer with minimum porosity with approximately 15μm thickness. Anodization was carried out in a sulphuric acid bath with well-defined process parameters and the anodized layer thickness & Inter pore distance were measured for the chosen process parameter combinations. Porosity index was calculated and an optimized parameter combination was obtained. Voltage was found out to be most influencing parameter in the determination of porosity and thickness. In addition to this, surface finish of the non-anodized and anodized specimens was also compared. It was found out that surface finish of the specimen decreased after anodization. A statistical data model was prepared for thickness and porosity using the data obtained from experiments.

726. Histological changes in the mammary gland of guinea-pigs during lactation

Certain histological factors of the mammary gland and the DNA content unit per dry weight were studied at four stages of lactation in guinea-pigs.The porosity index, the number of alveoli per field, the number of cells per field and the DNA content, showed maximal values at parturition and minimal values at the peak of lactation, whereas the opposite trend was shown by the value for modal alveolar diameter and the number of cells per modal alveolus.The relationships between these results are discussed.

STUDIES ON THE HORMONAL INDUCTION OF MAMMARY GROWTH AND LACTATION IN THE GOAT

SUMMARY 1. Treatment of spayed virgin goats with oestrogen ('triggering'), following administration of oestrogen and progesterone for 150 days to cause udder development, had no significant effect on the milk yield or on the structure of their udders. 2. Daily injections of 0·5 mg hexoestrol plus 70 mg progesterone for 150 days with or without the final oestrogen 'triggering' treatment induced udders which were virtually free from histological abnormalities and in which the alveolar tissue was homogeneous and compact. The milk yields were reasonably uniform between goats, and the incidence and degree of asymmetry in milk yield between two halves of the udder were no greater than in normally lactating goats. 3. Treatment for 20 weeks with oestrogen alone at daily doses ranging from 0·025 to 0·25 mg grew glands characterized by histological abnormalities previously found in glands developed with higher doses of oestrogen, namely cystic alveoli, papillomatous outgrowths from the epithelium and immature lobules. There was no graded relationship between dose of oestrogen and milk yield, and asymmetry of yield between the two halves of an udder was marked and widespread, particularly in the goats receiving the lowest dose. 4. Total alveolar surface areas of half-udders removed at the peak of lactation were estimated by three related methods, all of which gave high correlations with the milk yields of these udder halves. With only one of these methods, however, was there an appreciable partial correlation between porosity index (surface area/unit volume) and milk yield.