Chapter 3: Synthetic and Biological (Natural) Base Stocks

2009 ◽  
pp. 47-47-53 ◽  
Author(s):  
Syed Q. A. Rizvi
Keyword(s):  
Natural Base

(-)-Strempeliopine, stereoselective total synthesis and the determination of absolute configuration

1986 ◽  
Vol 51 (8) ◽  
pp. 1731-1742 ◽  
Author(s):  
Josef Hájíček ◽  
Jan Trojánek
Keyword(s):  
Circular Dichroism ◽  
Total Synthesis ◽  
Absolute Configuration ◽  
Determination Of Absolute Configuration ◽  
Natural Base ◽  
The Absolute ◽  
Circular Dichroïsm

A synthesis of (±)-strempeliopine (II) is described, the key step of which is the stereoselective reductive rearrangement of 18-methylene-1,2-dehydroaspidospermidine (XI). The absolute configuration of the natural (-)-base II was determined as (2S, 7R, 20R, 21R) on the basis of its synthesis from (+)-18-methylenevincadifformine (XVII) the configuration of which was derived from a comparison of circular dichroism properties of bases with a β-anilinoacrylate chromophore. The biogenesis of the alkaloids of the schizozygane type is discussed.

scholarly journals THE DYNAMICS OF DISTRIBUTION AND FEATURE OF THE DEVELOPMENT OF AMERICAN WHITE BUTTERFLY (HYPHANTRIA СUNEA DRURY) ON THE VYNNYTSYA REGION

2019 ◽  
pp. 152-162
Author(s):  
Pavel Verheles ◽  
Natalya Pinchuk ◽  
Tatyana Kovalenko
Keyword(s):  
Population Density ◽  
Land Tenure ◽  
Forest Steppe ◽  
Private Land ◽  
Stages Of Development ◽  
Natural Base ◽  
General Aspects ◽  
The Right

The results of study of dynamics of quantity of the American white butterfly are reflected in the article, taking into account chronology of population density of districts of area. It is indicated on actuality of problematiki of adjusting of this dangerous quarantine wrecker, taking into account his harmfulness and wide specialization. The results of statistical account of quantity of wrecker are generalized as a quarantine object in the cut of districts of the Winnitca area. The division of character of settling of territory a wrecker is conducted in the variants of private land-tenure and different economies. On the basis of own researches the feed natural base of wrecker is appraised at the level of region and conclusions are done about the prospects of growth of his quantity in default of quarantine measures. The stages of development of wrecker are in detail analysed and confronted with the proper stages characteristic in general under conditions of the right-bank Forest-steppe of Ukraine. The conclusions about the general aspects of prevalence of wrecker and separate factors of optimization of defence of the fruit planting at the level of area awas done.

Excitation Energies from a Partially Spin-Restricted Wave Function

2007 ◽  
Vol 3 (1) ◽  
pp. 65-69 ◽  
Author(s):  
V.N. Glushkov
Keyword(s):  
Wave Function ◽  
Excited States ◽  
Electron Correlation ◽  
Electronic Excitation ◽  
Slater Determinant ◽  
Molecular Orbitals ◽  
Reference Configuration ◽  
Excitation Energies ◽  
Hartree Fock ◽  
Natural Base

A singe Slater determinant consisting of restricted and unrestricted, in spins, parts is proposed to construct a reference configuration for singlet excited states having the same symmetry as the ground one. A partially restricted Hartree-Fock approach is developed to derive amended equations determining the spatial molecular orbitals for singlet excited states. They present the natural base to describe the electron correlation in excited states using the wellestablished spin-annihilated perturbation theories. The efficiency of the proposed method is demonstrated by calculations of electronic excitation energies for the Be atom and LiH molecule.

Students' landscaping preferences for open spaces for their campus environment

2019 ◽  
Vol 30 (1) ◽  
pp. 87-98 ◽  
Author(s):  
Ahmad Hami ◽  
Babak Abdi
Keyword(s):  
Leisure Time ◽  
Spatial Organization ◽  
Positive Association ◽  
Landscape Patterns ◽  
Open Spaces ◽  
Campus Environment ◽  
Different Types ◽  
Natural Base ◽  
Curved Paths ◽  
Student Socialization

This study seeks to find appropriate landscape patterns of campus based on students’ preferences. A photo questionnaire containing scenes of different types of campus landscapes was distributed among 200 students in University of Tabriz, Iran. The results emphasized the importance of vegetation, seating areas and water features of campuses. Also, students prefer open spaces consisting of lawn and grass (M = 3.31, S.D. = 1.00). Students also prefer a campus, which has a natural base, landscape elements and seating places, while the least preferred (M = 2.96, S.D. = 0.89) scenes comprise a large amount of hardscape. Students had a different preference for landscaping of open study area and leisure time place where the studying area should be designed with vertical natural elements. Shading trees and benches were also highlighted as very important furniture for these places. In terms of spatial organization, the content analysis revealed that these areas should be open and spacious. Places for leisure time need to be decorated with informal landscape design for creating a pleasant view. Designing a landscape with various forms will make these places more pleasant. Scenes of curved paths and colourful plants for these places showed a positive association with student socialization activities.

Metasomatism and Intrusion in Jamaica

1942 ◽  
Vol 79 (3) ◽  
pp. 161-178 ◽  
Author(s):  
C. T. Trechmann
Keyword(s):  
Upper Cretaceous ◽  
Middle Eocene ◽  
Carbonaceous Shale ◽  
Blue Mountain ◽  
Natural Base ◽  
Granodiorite Porphyry

The nearest known pre-Cretaceous rocks to Jamaica are Jurassic in Western Cuba, and Carboniferous in Colombia, Venezuela, and Honduras, all about 500 miles away. The evolution of Jamaica seems to have been somewhat as follows. Andine (?) orogenesis on or near the site took place, accompanied by magmatic invasion; the rocks are nowhere seen “in situ”, but they have supplied pebbles of granite, granodiorite, porphyry, hornfels, vein stuff, and limestones, more or less foliated or marmorized, but not gneisses nor schists. There is no evidence that any of them are older than Cretaceous, but they go to form the oldest beds of the island, the massive Blue Mountain purple conglomerates whose composition varies from place to place and of which no natural base is seen. Interbedded with these conglomerates are fossiliferous shales and Rudist limestones of Upper Senonian to Maestrichtian age. Low down, however, there is in Eastern Jamaica a bed of algal and foraminiferal limestone, without Rudistae, which was partly torn up and incorporated as rolled pebbles in the conglomerate. Some of these pebbles contain Camerina dickersoni Palmer, a foraminifer of Upper Cretaceous age, so the pebbles are but little older than the conglomerate containing them. Laramide orogenesis took place and this series was invaded by granodiorite and other intrusions. The uplifted area was eroded and some of the igneous and associated Cretaceous rocks exposed to denudation. Depression occurred and Lower or Lower Middle Eocene Carbonaceous shale or Richmond Beds, a Flysch-like series of limestones, shales, and conglomerates, were deposited.

scholarly journals Performance of Rosin Modified Antifouling Coated on Mild Steel Surface at Various Immersion Orientation

2019 ◽  
Vol 8 (12) ◽  
pp. 5562-5565
Keyword(s):  
Steel Substrate ◽  
Oyster Shell ◽  
Antifouling Paint ◽  
Good Efficiency ◽  
Marine Fouling ◽  
Abnormal Growth ◽  
Testing Method ◽  
Pine Tree ◽  
Efficient Protection ◽  
Natural Base

Steel is one of materials that been used as a hull to build a ship. Steel are well known as strong, easy to fabricate and can withstand higher loading. Major problem for steel in shipbuilding are corrosion and marine fouling. Antifouling paint are applied at underwater hull paint to protect and slowing the microorganism growth, plant and animal that attached to the ship bottom hull. Important additive in antifouling paint known as Tributyltin (TBT) was previously observed good efficiency in prevent marine growth, however International Maritime Organization (IMO), in 2008 banned the usage of TBT due to abnormal growth of oyster shell. Thus, it is crucial to focus on an environmentally friendly antifouling paint and additive. Rosin modified paint is one of natural base of paint matrix that extract from pine tree. Performance of rosin modified with commercial biocide additive at various orientation are evaluate by referring to standard testing method on antifouling panels in shallow submergence. Rosin modified base observed good interaction with primer and steel substrate. Rosin modified antifouling (AF) coating for orientation 0º, 90º and 180º shows less than 4% marine growth after 30 days of immersion. AF coated at 0º and 90º -a orientation observe efficient protection with no marine growth occurred after 30 days of immersion.

scholarly journals A riqueza e composição de formigas como indicadores dos efeitos do manejo florestal de baixo impacto em floresta tropical no estado do Acre

2013 ◽  
Vol 37 (1) ◽  
pp. 163-173 ◽  
Author(s):  
Patricia Nakayama Miranda ◽  
Elder Ferreira Morato ◽  
Marco Antonio Oliveira ◽  
Jacques Hubert Charles Delabie
Keyword(s):  
Natural Base

A sustentabilidade da extração madeireira seletiva depende de avaliações de impacto e monitoramento dos fatores abióticos, vegetação e fauna. Os objetivos deste trabalho foram estimar e comparar a riqueza e composição de formigas em área de manejo florestal sustentável de baixo impacto, no Projeto de Assentamento Chico Mendes, no Acre. As coletas foram realizadas com armadilhas pitfall e extrator de Winkler, em 30 parcelas de 10 x 10 m. As parcelas foram igualmente distribuídas em três tratamentos: (1) manejo - base de árvores exploradas em 2007; (2) queda natural - base de árvores caídas naturalmente em área não manejada; e (3) controle - parcela sem queda de árvore na mesma área não manejada. Para a caracterização da vegetação, foram tomadas medidas das variáveis: densidade arbórea e arbustiva, área basal arbórea e de árvores caídas, espessura de serapilheira e cobertura de dossel. A densidade arbórea foi significantemente maior no tratamento controle que no manejo. Diferenças significativas foram encontradas em cobertura de dossel entre os tratamentos controle e manejo e controle e queda natural. Foram coletadas 88 espécies de formigas, distribuídas em sete subfamílias. Não houve diferença na riqueza de espécies entre os tratamentos. Embora menor similaridade tenha sido encontrada entre os tratamentos manejo e controle, não foram observadas grandes diferenças na composição entre eles. Esses resultados indicaram que, nessa área, a atividade de extração madeireira de baixo impacto não afetou a assembleia de formigas, portanto, funcionalmente, essa forma de manejo não acarretou alterações no ecossistema em relação aos serviços associados às formigas.

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