Chiral N-protected α-amino aryl-ketones are one of the useful precursors used in the synthesis of various biologically active compounds and can be constructed via Friedel-Crafts acylation of N-protected α-amino acids. One of the drawbacks of this reaction is the utilization of toxic, corrosive and moisture-sensitive acylating reagents. In peptide construction via amide bond formation, N-hydroxy...

friedel–crafts synthesis of triarylmethanes over 3-methyl-1-sulfonicacid imidazolium tetrachloroaluminate under green conditions:in this work, friedel–crafts (fc) alkylation of various arenes with aromatic aldehydes catalyzed by 3-methyl-1-sulfonic acid imidazoliumtetrachloroaluminate {[msim]alcl4}, as a green catalyst, to prepare triarylmethanes (tams) has been carried out. some aromatic aldeh...

Nowadays, application of high speed crafts with large tonnage is of our country's essences. In order to gain high speed, new multi hull crafts are traditional. A hull form having been used recently in frigates is the Trimaran. Trimaran hull form and motion have been extensively studied due to the development of numerical and analytical methods as well as the exploitation of experimental setup. ...

A key challenge in contemporary ecology and conservation is the accurate tracking of the spatial distribution of various human impacts, such as fishing. While coastal fisheries in national waters are closely monitored in some countries, existing maps of fishing effort elsewhere are fraught with uncertainty, especially in remote areas and the High Seas. Better understanding of the behavior of th...

The considered model will be formulated as related to ”the fishing problem” even if the other applications of it are much more obvious. The angler goes fishing. He uses various techniques and he has at most two fishing rods. He buys a fishing ticket for a fixed time. The fishes are caught with the use of different methods according to the renewal processes. The fishes’ value and the inter arriv...

The ocean surgeonfish Acanthurus bahianus, an abundant small herbivore on reefs throughout the tropical west and central Atlantic, is a significant component of Caribbean trapfishery catches. To assess effects of fishing on this species we compared its longevity, survivorship, size and abundance at localities throughout its range that have differing intensities and targets of fishing. Temperatu...

Fish is generally regarded as a primary source of protein for many poor African fishing communities. The present study compared the relative importance of fish as a high-quality dietary protein source with meat in fishing communities in two states in Nigeria. Fifty fishing households in which active fishing was the primary activity and fifty non-fishing households (agriculture being stated as p...

Historically, it has been difficult to balance conservation goals and yield objectives when managing multispecies fisheries that include stocks with various vulnerabilities to fishing. As managers try to maximize yield in mixed-stock fisheries, exploitation rates can lead to less productive stocks becoming overfished. In the late 1990s, population declines of several U.S. West Coast groundfish ...

fishing as one of the most important agricultural sectors has an important role in providing the protein for people. pareh cooperatives despite of having a long history, are faced with problems such as loss of fishing catch compare with previous years, the high cost of purchasing tools and equipments to catch and transportation and location of fishing become unfavorable due to natural and human...