Search results for "Mining"
showing 10 items of 1730 documents
SN1 Reactions in Supercritical Carbon Dioxide in the Presence of Alcohols: the Role of Preferential Solvation
2016
Ethanol (3b) inhibits SN1 reactions of alkyl halides 1 in supercritical carbon dioxide (scCO2) and gives no ethers as products. The unexpected behaviour of alcohols 3 in the reaction of alkyl halides 1 with 1,3-dimethoxybenzene (2) in scCO2 under different conditions is rationalised in terms of Bronsted and Lewis acid–base equilibria of reagents, intermediates, additives and products in a singular solvent characterised by: (i) the strong quadrupole and Lewis acid character of carbon dioxide, which hinders SN2 paths by strongly solvating basic solutes; (ii) the weak Lewis base character of carbon dioxide, which prevents it from behaving as a proton sink; (iii) the compressible nature of scCO…
Nonlocal van der Waals Approach Merged with Double-Hybrid Density Functionals: Toward the Accurate Treatment of Noncovalent Interactions
2015
Noncovalent interactions drive the self-assembly of weakly interacting molecular systems to form supramolecular aggregates, which play a major role in nanotechnology and biochemistry. In this work, we present a thorough assessment of the performance of different double-hybrid density functionals (PBE0-DH-NL, revPBE0-DH-NL, B2PLYP-NL, and TPSS0-DH-NL), as well as their parent hybrid and (meta)GGA functionals, in combination with the most modern version of the nonlocal (NL) van der Waals correction. It is shown that this nonlocal correction can be successfully coupled with double-hybrid density functionals thanks to the short-range attenuation parameter b, which has been optimized against ref…
Thermal Analysis, Mechanical and Rheological Behaviour of Melt Manufactured Polyethylene/Liquid Crystal Polymer Blends
2011
Modification of properties of conventional thermoplastics with thermotropic liquid crystal polymers, from one hand, allows decrease their viscosities, substantially facilitating processing conditions, and, from another hand, allows increase their exploitation properties. Orientation of the labile structure of liquid crystal polymer in extrusion or injection moulding causes specific reinforcement (so-called self-reinforcement) to occur in the blends containing liquid crystal polymer. Up to now the effect of self-reinforcement is mostly investigated in the blends, containing considerable amount of liquid crystal polymer. In this research the effect of minor amounts of liquid crystalline co-po…
Kinetische untersuchungen zur reaktionsfähighkeit von chlormethylgruppen in methylendiphenolen
1984
The chloromethyl derivatives of 16 differently substituted methylenediphenols were synthesized for the first time. To compare their reactivity, the solvolysis in methanol and the animolysis with an excess of p-nitroaniline in dimethyl sulfoxide were studied kinetically at 25°C. The rate constants for the methanolysis do not differ very much, beside of the fact that para-chloromethyl derivatives react about 100 times faster than ortho-chloromethyl derivatives. However, for the aminolysis a large acceleration up to 103 was found for compounds having both hydroxyl groups in ortho-position to the methylene bridge. Obviously, the cleavage of the OH bond, which occurs in the rate determining step…
Der einfluß benachbarter grundbausteine auf die ammonolyse von essigsäureestern phenolischer mehrkernverbindungen
1972
Die Ammonolyse der Essigsaureester verschiedener phenolischer Zwei- und Dreikernverbindungen, die neben Methylphenolbausteinen jeweils einen Nitrophenolbaustein enthalten, wurde untersucht. In allen Fallen wird wie bei einkernigen Nitrophenylestern die Esterbindung im Nitrophenolbaustein ammonolytisch gespalten. Wenn die Bausteine uber Methylenbrucken in ortho-Stellung zu den phenolischen Hydroxylgruppen verknupft sind, werden jedoch auch die Esterbindungen in den Methylphenolbausteinen gespalten, obwohl die Ester von Methylphenolen und Mehrkernverbindungen, die nur Methylgruppen als Substituenten tragen, unter gleichen Bedingungen durch Ammoniak nicht angegriffen werden. In ubereinstimmung…
Immunohistochemical localization of nitric oxide synthases
1996
Corrigendum to “Effects of Oleuropein on tumor cell growth and bone remodeling: Potential clinical implications for the prevention and treatment of m…
2021
Evaluation of the retinal nerve fiber layer thickness in smokers
2019
Kompensācija cietušajam par nodarīto kaitējumu kriminālprocesā
2015
Mūsdienās aizvien ir aktuāla morālā kaitējuma kompensācijas noteikšana kriminālprocesā, it sevišķi tāpēc, ka morālam kaitējumam nepastāv precīzi nosakāms naudas ekvivalents. Darba mērķis ir izveidot universālu, ilgspējīgu morālā kaitējuma noteikšanas koncepciju, skaidri noteikt kritērijus, kuri tiesnešiem jāņem vērā, lemjot par kaitējuma kompensācijas apmēru, turklāt izpētīt arī praktiskos jautājumus, kas saistās ar kompensācijas pieteikšanu. Pētījuma rezultātā izstrādāta ilgspējīga morālā kaitējuma koncepcija, kurā noteikti rekomendējoši, taču aptuveni kompensācijas piešķiršanas apmēri, kā arī piedāvāti vairāki Kriminālprocesa likuma grozījumi.
Semantic place recognition for context aware services
2012
Extracting the meaning of the most significant places, which are frequently visited by a mobile user, is a relevant problem in mobile computing. Predicting semantic meaning of such places is useful in many areas. The problem of place semantic annotation of a user location can be challenging for service providers. Awareness of user activities is very important for development of personalized applications, which can be used in health care systems, living systems, etc. Predicting location of mobile users not only enables development of high quality location-based services and applications, but also improves resource reservation in wireless networks. In this research several solutions for seman…