Beach erosion triggered by river mouth dredging as a measure against river mouth closure

On a pocket beach, the impact of the formation of the wave-shelter zone and the maintenance dredging of a river mouth reaches the entire pocket beach, and overall beach changes are triggered, devastating the natural environment. These topographic changes owing to anthropogenic factors took place at many coasts in Japan with the development of the coastal zone. We investigated this issue, taking the Haraoka and Tatara coasts in Chiba Prefecture as examples. Although several measures have been taken such as the sand back pass to mitigate the erosion, problems have not yet been solved. We discuss the reality and propose several measures to solve these problems

Topographic changes on Ajigura beach triggered by elongation of offshore breakwater

On Ajigaura Beach in Ibaraki Prefecture, Japan, severe beach erosion has occurred. Despite beach nourishment as a measure against beach erosion, wave run-up damage occurred in the south part of the beach where the foreshore was narrowed. The topographic changes of the beach were investigated on the basis of past aerial photographs and bathymetric survey data, and a numerical simulation using the BG model (a three-dimensional model for predicting beach changes based on Bagnold???s concept) was carried out. The measured and calculated results were in good agreement. It was concluded that the beach changes at Ajigaura Beach were triggered by northward longshore sand transport, which was induced by the wave-sheltering effect of the offshore breakwater

Essays on river mechanics

CER92-93-PYJ-5.Presented by the Graduate Students in CE 717 - River Mechanics (Spring 1993).Includes bibliographical references.April 1993

Formulation of risperidone in floating microparticles to alleviate its extrapyramidal side effects

Risperidone is effective in the treatment of positive as well as negative symptoms of schizophrenia. But, there is a strong correlation between plasma levels of risperidone and its adverse effects. Objective: This study aimed to develop risperidone in floating microparticles to overcome its extrapyramidal side effects. Methods: Floating microparticles were prepared using Eudragit S100, hydroxypropylmethyl cellulose (HPMC), Gelucires (Gelucire 43/01 pellets, Gelucire 44/14 and Gelucire 50/13), Geleol mono and diglyceride NF, glyceryl monostearate, Compritol 888 ATO, methyl-betacyclodextrin (MβCD) and hydroxypropyl-betacyclodextrin (HPβCD), by emulsion solvent diffusion technique. In-vitro experiments were conducted to optimize formulation parameters regarding floating ability, yield value, drug loading and in-vitro release properties. The best formula was investigated for its in-vivo floating ability and for its pharmacokinetics as well as its extrapyramidal side effects in human volunteers. Results: The optimized floating microparticles showed promising in-vitro experiment performance with floating ability up to 95.93% for 12 h. Also, this floating ability was confirmed using in-vivo x-ray studies. Pharmacokinetics studies revealed significant (p < 0.05) lower Cmax, longer Tmax and higher AUC values for the optimized formula compared to the marketed oral product (Risperidal® 4 mg tablets) indicating gradually release properties which lead to high treatment efficacy of the drug with obvious reduced extrapyramidal side effects. Conclusion: These results proved that formulating risperidone as floating microparticles is a suitable dosage form for overcoming risperidone side effects

Performance of some rice (Oryza sativa L.) cultivars under water shortage and high temperature stress

Water shortage and heat are the most devastating abiotic stresses threating global food security. To understand the behavior of germplasm under both abiotic stresses, thirteen rice genotypes were selected for the study to make evaluation under water shortage and heat stress condition. The results showed that the year mean squares were significant and highly significant for all agronomical traits except, flag leaf area, number of tillers plant-1, number of panicles plant-1, 100 grain weight, grain yield plant-1 and harvest index indicated overall wide differences of weather during both years. Environments mean squares were found to be highly significant over all traits were used, indicating that all environments showed significant differences. The highly significant differences were observed among genotypes and G x E interaction for all characteristics except, panicle length. Concerning the cultivars performance across three environments, the cultivars Giza 178, Giza 179, Sakha 107, Hybrid 1, Hybrid 2 gave the best desirable values over normal, drought and heat stress conditions so, these cultivars are considered to play vital role in breeding program to enhancement for drought and heat stresses and have high yield potential. The highly significant and positive correlation were found among the all traits under investigation except with flag leaf angle, leaf rolling and sterility percentage. The results will further help to utilize the genotypes for further crop improvement breeding programs