Synthetic And Mechanistic Features Of Base-catalyzed Homoenolization And Homoketonization

The behavior of a variety of homoenolate anions generated either by hydrolysis of polycyclic ethers (homoketonization) or by base-catalyzed hydrogen abstraction from polycyclic ketones (homoenolization) has been investigated.;A series of polycyclic derivatives of cyclopropanol were prepared and the base-catalyzed ketonization of the corresponding cyclopropoxides was examined to establish the regio- and stereochemistry of the ring cleavage. The examples derived from 2.2.1 and 2.2.2 ketones, by Simmons-Smith cyclopropanation of their silyl enol ethers, were found to undergo ring expansion preferentially while less-strained analogs gave the (alpha)-methyl derivatives of the initial ketone. In all cases of ring expansion, the cleavage proceeds with high stereoselectivity favoring inversion of configuration upon protonation (deuteration).;A novel means of generating the 2-trimethylsilyl ethers of substituted homoquadricyclenes was discovered. Base-catalyzed ketonization of these derivatives was found to yield either the tricyclo 3.2.1.0(\u272,7) or 3.3.0.0(\u272,8) octanone skeletons depending upon the substitution at the 8-position of the starting material.;The Simmons-Smith reaction with t-butyldimethylsilyl enol ether of some polycyclic ketones under concentrated conditions led to cyclopropanation and isomerization to furnish the ring expanded allylic silyl ethers.;The behavior of the 7,7-dimethyltricyclo 3.3.1.0(\u272,7) nonan-6-ones under strongly basic conditions was examined to determine the effect of the three-membered ring for comparison with earlier findings for the 3.2.1.0(\u272,4) analogs. While the endo isomer was found to be stable, the exo isomer readily rearranged to 8,8-dimethyltricyclo 4.3.0.0(\u272,4) nonan-7-one. Experiments in t-BuOD were carried out to establish the several sites of deuterium incorporation in the initial ketones. These results clearly revealed that the three membered ring influences both the regio- and stereochemistry of (beta)-enolate formation. The observed differences for the exo and endo isomers of the 3.3.1.0(\u272,4) nonanones can be attributed to conformational differences.;Some support for this proposal was provided by the reactivities of endo-9,9-dimethyltricyclo 5.3.1.0(\u272,6) undecan-8-one, endo-3-t-butyl-3-methylbicyclo 3.2.1 octan-2-one and endo-9-t-butyl-9-methyltricyclo 5.3.1.0(\u272,6) undecan-8-one under strongly basic conditions.;Homoenolization of the 3,3-dimethyl-7-spirocyclopropyl and -7-isopropylidene derivatives of norcamphor provide efficient syntheses of the corresponding 3,3-dimethyl-5-substituted norcamphors. Hydrogenolysis of the 5-spirocyclopropyl derivative furnished the hitherto unknown 3,3,5,5-tetramethylcamphor

European's biochemical engineering to face the megatrends and associated challenges beyond 2020

info:eu-repo/semantics/publishedVersio

Santvarų topologijos ir formos optimizavimas genetiniais algoritmais

In the paper the global optimization problem of truss systems is studied.  The genetic algorithms are employed for the optimization. As the objective function the structure mass is treated; the constraints include equilibrium, local stability and other requirements.  All the truss system characteristics needed for genetic algorithm are obtained via finite element solution. Topology optimization of truss system is performed using original modified genetic algorithm, while the shape optimization – using ordinary genetic algorithm. Numerical solutions are presented. The obtained solutions are compared with global extremes obtained using full search algorithm.  All the numerical examples are solved using original software.Straipsnyje nagrinėjamas strypinių sistemų (santvarų) globaliosios optimizacijos uždavinys. Optimizavimui naudojami genetiniai algoritmai. Tikslo funkcija imama konstrukcijos masė, kurią stengiamasi minimizuoti nepažeidžiant iš anksto nustatytų apribojimų (pusiausvyros, stabilumo ir kt.).  Visos genetiniam algoritmui reikalingos santvaros charakteristikos skaičiuojamos baigtinių elementų metodu. Santvarų topologijos optimizavimas atliekamas autorių modifikuotu genetiniu algoritmu, o formos optimizavimas – paprastu genetiniu algoritmu. Pateikiami skaitiniai pavyzdžiai. Gauti sprendiniai lyginami su globaliaisiais ekstremumais, gautais perrinkimo būdu. Visi uždaviniai išspręsti su autorių sukurta originalia programine iranga

Comparison of UAV images processing softwares

Recently, the aircrafts tend to be replaced by unmanned, light, simple, aerial vehicles (UAVs), same can be said about the field of aerial photogrammetry. UAV system besides the standard airframe and engine includes main processor board, Inertial Navigation System (INS), Global Positions Systems (GPS), telemetry module. For areal imaging purposes there can be a photo camera mounted too. The images taken by the areal camera can later be processed by software which is specialized for photogrammetry. The project of testing Pix4d Mapper (Switzerland) and PhotoMod (Russia) software programs is described in this paper. Pix4d Mapper is software specialized for UAV images proceedings meanwhile PhotoMod is designed for common photogrammetry proceedings. PhotoMod request some special photogrammetric knowledge from the user. There were 36 images processed producing ortho-mosaic and surface model. The results are further described in the paper

Įstatymo samprata.

Under the Constitution of the Republic of Lithuania a law (statute) is a universal mean to ensure the implementation of the constitutional principle of the equality of individuals (as courts and other state institutions as well as officials are not sovereign and obey exceptionally the laws). It is not possible to ensure the equality of individuals if decisions made in each individual case are not based on clear rides of general character. This is determined not only by a possibility of abuse of office by institutions and officials who have wide powers unrestricted by general rides but also by absence of an objective equality standard. Pursuant to the Constitution, all individuals are (must be) equal before the law and the ndes of general character can ensure the equality. Only the ndes of general character can he set forth in a law. Exceptions must be envisaged by the Constitution, for example, approving the state budget drawn up of the norms of individual character. All the primary (establishing original rights and duties) standards of law must be consolidated in laws. This means that even laws cannot envisage the rules of individual character that are not based on the rules of general character. As legality of laws is assessed according to their conformity with the Constitution, in Lithuania laws do not have the typical aspect of the supreme legal power. They can only have the specific legal power attributed to them. Taking into consideration the analysis of the features of law carried out in the thesis, a law of the Republic of Lithuania is defined as follows: (I) the Seimas or the nation - (2) enacted laws pursuant to the special procedure envisaged by the Constitution and the laws, (3) that are in line with the Constitution; (4) a law is an official written document (5) expressing the lawmakers’ will (6) to set primary rules (7) that hold a specific legal power and (8) general rules of behaviour (9) sanctioned with the state control.Terminas „Įstatymas" vartojamas kefiomis prasmėmis. Apie Įstatymus kalbame kaip apie bendras taisykles, kaip apie teisės normas fiksuojančius aktus, kalbame ir kaip apie specifinę teisės normų aktų kategoriją - „Įstatymą, griežtąja prasme". Tačiau netgi įstatymas griežtąja prasme" nėra apibrėžiamas vienareikšmiškai. Teoriniu lygmeniu kyla nemažai ginčų dėl to, ar vienas arba kitas konkretus požymis priskirtinas Įstatymui. Nuo seno bene daugiausia ginčų kelia įstatymo bendrumo požymis. Pastaruoju metu plačiai išplitus konstitucionalizmo įdėjome, vle daugiau abepnlų kyla ir dėl „tradicinių" požymių - aukščiausia teisinė galia, pirminis aktas ir pan. Šiame straipsnyje įstatymo sampratą (faktiškai įstatymo požymius, per kuriuos ta samprata atsiskleidžia) stengiamasi analizuoti kompleksiškai, t. y. integruojant ne vien teorinį (kas buvo daroma nuo Antikos laikų), bet ir pozityvųjj teisinį aspektą. Taigi remiantis Lietuvos Respublikos Konstitucija bandoma Įvertinti ir pagristi, ar tam tikri „teoriniai" Įstatymo požymiai turi adekvatų teisinĮ turinj ir gali būti laikomi teisiškai reikšmingais Įstatymo požymiais. Atlikus įstatymo požymių analizę, straipsnio pabaigoje pateikiama įstatymo samprata pirmiausia grindžiama galiojančia Lietuvos Respublikos Konstitucija