• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 60
  • 29
  • 15
  • 4
  • 4
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 148
  • 41
  • 32
  • 30
  • 26
  • 23
  • 18
  • 17
  • 17
  • 16
  • 16
  • 15
  • 14
  • 13
  • 12
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Syntéza nových typů biologicky aktivních látek s využitím organokovových sloučenin / Synthesis of New Types of Biologically Active Substances Using the Organometallic Compounds

Korotvička, Aleš January 2016 (has links)
This work consists of four separate chapters. Although they are seemingly different projects, they have a common feature - the application of organometallic chemistry. 1. Lusianthridin and denbinobin, the phenanthrene derivatives, can be found in plants of the family Orchidaceae. They exhibit cytostatic activity against cancer of human lung and ovarian and against promyelocytic leukemia. Therefore, new synthetic methods for these substances may be applied in research and development of new bioactive compounds. I prepared 9,10- disubstituted phenanthrenes through reactions of biphenylene with alkynes, which were catalyzed by iridium complexes. Phenanthridine derivatives are found naturally in the group benzo[c]phenanthridine alkaloids. The most famous of these include sanguinarine and chelerythrine. Sanguinarine selectively induces apoptosis (planned cell death) of human cancer cells and, therefore, is investigated as a potential antitumor agent. Chelerythrine selectively inhibits protein kinase C, leading again to apoptosis. I have studied reactions of biphenylene with nitriles catalyzed by rhodium complexes that have not been described yet. By this, I prepared a series of 6-substituted phenanthridines. 2. Carboranes are artificially prepared organic compounds of boron, which are not represented in...
2

Accessing fused and spirocyclic ring formations via carbon - carbon bond activation

Savage, Nikolas Alexander 24 March 2014 (has links)
Carbon-carbon bonds are ubiquitous in synthetic chemistry and constitute the skeletal backbone of a significant number of compounds. Utilizing transition metal mediated catalysis, a wide array of fused and spirocyclic ring systems containing diverse functionalization were accessed. These investigations provide unique ways to prepare carbon frameworks that are otherwise nontrivial to construct using classical approaches. The derivatives were rapidly accessed through optimized methods. / text
3

The business activities of C.C. Washburn

Marquette, Clare Leslie, January 1940 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1940. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 423-435).
4

The banking activities of C.C. Washburn

Marquette, Clare Leslie, January 1937 (has links)
Thesis (M.A.)--University of Wisconsin--Madison, 1937. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 80-82).
5

The business activities of C.C. Washburn

Marquette, Clare Leslie, January 1940 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1940. / Typescript. Vita. Title from title screen (viewed May 9, 2006). Includes bibliographical references (leaves 423-435). Online version of the print original.
6

Regioselective reactions at a diruthenium centre

Wilkinson, Jon N. January 1999 (has links)
No description available.
7

Transition metal catalyzed regioselective carbon-carbon bond formation mediated by transfer hydrogenation

Sam, Brannon 03 September 2015 (has links)
One of the more formidable challenges in the synthesis of complex organic molecules remains the efficient formation of carbon-carbon bonds. The development of a broad class of reactions to achieve this goal involves the addition of carbon based nucleophiles to carbonyl and imine compounds. Until recently, classical approaches to carbon-carbon bond formation generally required the use of stoichiometric pre-formed organometallic reagents to serve as nucleophiles, which translate into stoichiometric organometallic byproducts. In an effort to minimize nucleophile pre-activation and byproduct formation, our lab has developed efficient methods for carbonyl and imine additions via in situ formation of alkyl metal nucleophiles from π-unsaturates. The research reported herein describes our advances in an assortment of transition metal-catalyzed carbon-carbon bond forming reactions mediated by transfer hydrogenation, including regioselective hydrohydroxymethylation, hydrohydroxyfluoroalkylation, and hydroaminomethylation. Additionally, the investigation of regioselective carbonyl vinylation is reported. / text
8

A no-thin-air memory model for programming languages

Pichon-Pharabod, Jean Yves Alexis January 2018 (has links)
Many hardware and compiler optimisations introduced to speed up single-threaded programs also introduce additional, sometimes surprising, behaviours for concurrent programs with shared mutable state. How many of these extra behaviours occur in practice depends on the combination of the hardware, compiler, runtime, etc. that make up the platform. A memory model, which prescribes what values each read of a concurrent program can read, allows programmers to determine whether a program behaves as expected without having to worry about the details of the platform. However, capturing these behaviours in a memory model without also including undesirable "out-of-thin-air" behaviours that do not occur in practice has proved elusive. The memory model of C and C++ allows out-of-thin-air behaviour, while the Java memory model fails to capture some behaviours that are introduced in practice by compiler optimisations. In this thesis, we propose a memory model that forbids out-of-thin-air behaviour, yet allows the behaviours that do occur. Our memory model follows operational intuitions of how the hardware and compilers operate. We illustrate that it behaves as desired on a series of litmus tests. We show that it captures at least some of the expected behaviours, that it forms an envelope around some common compiler optimisations, and that it is implementable on common hardware using the expected compilation schemes. We also show that it supports some established programming idioms.
9

NON-DESTRUCTIVE EVALUATION OF CARBON/CARBON BRAKES USING AIR-COUPLED ULTRASONIC INSPECTION SYSTEMS

Stonawski, Ondrej 01 January 2008 (has links)
This thesis is focused on non-contact air-coupled ultrasonic Non-Destructive Evaluation (NDE) of Carbon-Carbon (C/C) disc brake materials. The minimum detectable defect size in the C/C composite disc brakes up to the maximum thickness of 1 7/16" (36.33 mm) using 120, 225 and 400 kHz transducers was investigated in the experimental section of this thesis. The effect of scanning increment step size on resolution of the final C-scan image was also investigated. The results indicated that the 12.7 mm diameter flat bottom drilled holes were reliably detectable using 225 kHz transducers. The flat bottom drilled holes and the side drilled holes of 6.35 mm in diameter were detectable on the final C-scan images of 225 kHz testing mainly due to the known locations of the defects. Results showed that testing frequency of 120 kHz provides very transparent C-scans. Testing frequency of 225 kHz provides also good transparency and better resolution. Testing frequency of 400 kHz did not provide satisfactory results. No advanced signal filtering techniques were utilized during the experiments. The relationship between the speed of sound in C/C material and the carbon fiber orientation in the carbon matrix needs to be investigated. The air-coupled ultrasonic testing of the C/C composite disc brake samples was conducted at the Center for Non-Destructive Evaluation at Iowa State University.
10

Cobalt- and Nickel-Catalyzed Functionalization of Unactivated C–Hal, C–O and C–H Bonds

Song, Weifeng 07 November 2013 (has links)
No description available.

Page generated in 0.0361 seconds