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Wyszukujesz frazę "reaction" wg kryterium: Temat


Tytuł:
Detonation Reaction Characteristics for CL-20 and CL-20-based Aluminized Mixed Explosives
Autorzy:
Liu, D.
Chen, L.
Wang, C.
Wu, J.
Tematy:
detonation reaction zone
aluminum reaction
interfacial particle velocity
interferometry
Pokaż więcej
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Powiązania:
https://bibliotekanauki.pl/articles/358308.pdf  Link otwiera się w nowym oknie
Opis:
The interfacial particle velocities for CL-20 and CL-20-based aluminized mixed explosives were measured by interferometry in order to analyze the aluminum reactions in the latter. The reaction characteristics were obtained, as well as a better understanding of the effects of aluminum powder on the detonation reaction zone length. Two functions were used to fit the particle velocity-time profiles, and their intersection was the corresponding Chapman-Jouget (CJ) point. From these profiles, the detonation reaction zone length and the aluminum reaction were then analyzed. CL-20-based explosives have a short reaction time (48 ns for a high CL-20 content), while the reaction time of CL-20/Al explosives increased with the aluminum content and particle size. Micron-scale aluminum particles barely reacted in the CL-20 detonation reaction zone, but instead reacted with the detonation products after the CJ point. This reduced the detonation pressure; however, the aluminum reaction can slow down the decrease in particle velocities. The start times of small-particle aluminum reactions were earlier than those of the larger particles. The 2-3-μm aluminum particles start to react within 1 μs after the CJ point, while the 200-nm particles may start to react in the reaction zone.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of the Progress of Reaction in the Preparation of tetra-Functional GAP using FTIR Spectroscopy
Autorzy:
Adak, Prasanta Kumar
Meena, Ashish Kumar
Ghosh, Mrinal
Sutar, Vikas
Jain, Mukesh
Banerjee, Shaibal
Tematy:
energetic binder
FTIR
reaction kinetics
reaction profiling
t-GAP
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Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Powiązania:
https://bibliotekanauki.pl/articles/59115336.pdf  Link otwiera się w nowym oknie
Opis:
Glycidyl azide polymer (GAP) with tetra hydroxyl functional groups or t-GAP is a potential energetic polymeric binder for application in both high energy propellants and high explosives. t-GAP is synthesized via azidation of the precursor tetrafunctional poly-epichlorohydrine (t-PECH) with sodium azide in DMSO solvent medium. In this article, process optimization and progress of chemical reaction for preparation of t-GAP is studied using FTIR spectroscopy and an attempt is made to predict the reaction kinetics with concentration profiling. The characteristic vibrational features corresponding to C‒N3 of t-GAP and C‒Cl of t-PECH have been used to monitor the progress of reaction.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Decomposition Pathways for Aqueous Hydroxylammonium Nitrate Solutions: a DFT Study
Autorzy:
Izato, Y.
Koshi, M.
Miyake, A.
Tematy:
hydroxylamine nitrate
reaction pathway
liquid-phase reaction
density functional theory
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Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Powiązania:
https://bibliotekanauki.pl/articles/357968.pdf  Link otwiera się w nowym oknie
Opis:
Hydroxylammmonium nitrate (hydroxylamine nitrate, HAN) is one of the most promising candidates as a replacement for commonly used liquid mono-propellants such as hydrazine. The reaction pathways involved in the initial and the catalytic decomposition of HAN in aqueous solution were determined using quantum chemistry calculations incorporating solvent effects. Optimized structures were obtained for the reactants, products and transition states at the ωB97XD/6-311++G(d,p)/SCRF = (solvent = water) level of theory and the total electron energies of these structures were calculated at the CBS-QB3 level of theory. In the initial decomposition, the ion-neutral NH3OH+-HNO3 reaction, the neutral-neutral NH3O-HNO3 reaction and the HNO3 self-decomposition pathways were all found to have reasonable energy barriers, with values of 91.7 kJ/mol, 88.7 kJ/mol and 89.8 kJ/mol, respectively. The overall reaction resulting from any of these pathways can be written as: HAN → HONO + HNO + H2O. The ionic reaction is dominant during the initial decomposition of HAN in aqueous solution because NH3OH+ and NO3– are the major species in such solutions. We also developed six catalytic mechanisms and each of these schemes provided the same global reaction: NH2OH + HONO → N2O + 2H2O. The t-ONONO2 oxidizing scheme is the most plausible based on the energy barrier results.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A meta-analysis of influence of yoga activities on reaction time as a component of skill related fitness
Autorzy:
Ghuntla, Tejas P.
Dholakiya, Jyoti R.
Tematy:
yoga activities
auditory reaction time
visual reaction time
fitness
effect
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Wydawca:
Akademia Tarnowska
Powiązania:
https://bibliotekanauki.pl/articles/26917700.pdf  Link otwiera się w nowym oknie
Opis:
Introduction: Yoga practices are known to have beneficial effect on cognitive functions. Reaction is a purposeful voluntary response to external stimuli. Reaction time is a component of skill related fitness. Humans gives response to different external environmental stimuli with different speed. Majority of daily work is done in response to visual and auditory stimuli. Yoga practices may improve reaction time. Objectives: To study influence of yoga practices on auditory reaction time and visual reaction time. Methods: Researchers used the Preferred Reporting Items for Systematic Reviews and Meta- Analyses (PRISMA) guidelines for reporting systematic reviews and meta-analysis. Researchers searched articles on PubMed, Google scholar and by manual search. Searched articles were screened for relevancy. By use of inclusion and exclusion criteria potential articles were selected. Results: Out of 287articles, finally 5 studies included in current meta-analysis. Yoga activities has effect on visual reaction time (VRT): SMD = 3.06, 95% CI = –0.66–6.78, P < 0.01 and auditory reaction time (ART): SMD = 2.86, 95% CI = –0.37–6.09. Conclusion: Yogic activities can provide beneficial effect on reaction time. Improved reaction time is important for reactive activity like sports. Yoga can be useful as a part of training in skill related work. There is wide scope for further studies to evaluate beneficial effects of yoga activities.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Selective Approaches to α- and β-Arylated Vinyl Ethers
Autorzy:
Funes-Ardoiz, Ignacio
Furman, Bartłomiej
Domzalska-Pieczykolan, Anna
Bolm, Carsten
Wydawca:
Wiley
Cytata wydawnicza:
Angew. Chem. Int. Ed. 2022, 61, e202109801 ; https://doi.org/10.1002/anie.202109801
Opis:
Polish National Agency for Academic Exchange for the Iwanowska Scholarship (No. PPN/IWA/2018/1/00009/U/00001); National Science Centre of Poland for ETIUDA No. UMO-2019/32/T/ST4/00099; University of La Rioja; “Beronia”; Projekt DEAL
We developed simple and efficient protocols for palladium-catalyzed regioselective a- and b-arylations of structurally diverse vinyl ethers. Both catalytic methods proceed under relatively mild reactions conditions applying to a broad substrate range including more complex compounds providing arylated glucal or isochromene. Lacking the common requirement of a large reagent excess, the transformations are highly economic and limiting the waste production. Results from computational studies (DFT) provided insight into the key factors determining the pronounced regioselectivities of the investigated reactions.
Dostawca treści:
Repozytorium Centrum Otwartej Nauki
Artykuł
Tytuł:
Kto się boi księcia Metternicha?
Autorzy:
Tarnawski, Eduard
Tematy:
conservatism, reaction, liberalism
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Wydawca:
Szkoła Główna Handlowa w Warszawie
Powiązania:
https://bibliotekanauki.pl/articles/630372.pdf  Link otwiera się w nowym oknie
Opis:
Th e author proposes a test for the propensity of being a reactionary that he calls ”Metternich test”, although Robert Stewart Castlereagh (1769–1822) could also be called as an examiner. Undoubtedly only Russian tsars can be considered reactionary monarchs, starting from Nicholas I (1796–1855). To judge whether president Putin is a reactionary we need authority of Alexandr Solzhenitsyn (1918–2008). Although Henry Kissinger is called Metternich of 20th century, he is not suit for the function of examiner. Author elaborates on the faith Metternich had in love as a force that makes politics possible. A person that can’t understand the life of other people, cannot understand history. Aft er Nicholas I became tsar all Russian doctinaires, such as Sergey Uvarov (1786–1855), Konstantin Leontiev (1831–1891) and Konstantin Pobedonostsev 1827–1907), formulated principles of reaction. The paper ends with Wacław Nałkowski’s (1851–1911) critique of Henryk Sienkiewicz as a reactionary.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
How familiarity warps representation in the face space
Autorzy:
Chauhan, Vassiki
Gobbini, M. Ida
Kotlewska, Ilona
Tang, Sunny
Opis:
Recognition of familiar as compared to unfamiliar faces is robust and resistant to marked image distortion or degradation. Here we tested the flexibility of familiar face recognition with a morphing paradigm where the appearance of a personally familiar face was mixed with the appearance of a stranger (Experiment 1) and the appearance of one's own face with the appearance of a familiar face and the appearance of a stranger (Experiment 2). The aim of the two experiments was to assess how categorical boundaries for recognition of identity are affected by familiarity. We found a narrower categorical boundary for the identity of personally familiar faces when they were mixed with unfamiliar identities as compared to the control condition, in which the appearance of two unfamiliar faces was mixed. Our results suggest that familiarity warps the representational geometry of face space, amplifying perceptual distances for small changes in the appearance of familiar faces that are inconsistent with the structural features that define their identities. Significance statement Familiar faces are recognized robustly despite image degradation, differences in lighting, head position, or distance. Here, we investigated the flexibility of familiar face recognition with two separate experiments using a morphing paradigm. Our data suggest that a familiar face occupies a sector of perceptual face space that is expanded relative to its extent based on differences in measured physical similarity. This expansion in representational space may be part of a more general mechanism that could explain how learning can facilitate processing of behaviorally relevant stimuli.
Dostawca treści:
Repozytorium Uniwersytetu Jagiellońskiego
Artykuł
Tytuł:
Magnetic recykling of complex catalysts immobilized on thiol-functionalized polymer supports
Autorzy:
Bączek, N
Strzelec, K.
Wąsikowska, K.
Tematy:
encapsulation
magnetic recycling
epoxy resin
supported catalysts
Heck reaction
hydrogenation reaction
Pokaż więcej
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Powiązania:
https://bibliotekanauki.pl/articles/779554.pdf  Link otwiera się w nowym oknie
Opis:
In this work, the application of the thiol-functionalized epoxy resin encapsulated on magnetic core as supports for palladium catalysts is reported. The study focuses on obtaining of heterogeneous catalysts which can be separated by magnetic field. Palladium complex catalyst [PdCl2(PhCN)2] has been heterogenized by anchoring to these supports via ligand exchange reaction. The characterization of polymeric supports and heterogenized palladium catalysts has involved research methods like time-of-flight secondary ion mass spectrometry (TOF-SIMS), scanning electron microscopy (SEM) and nitrogen BET surface area measurements. The activity and stability during long-term use of the investigated catalytic systems were tested in a Heck and hydrogenation reaction. The influence of the type of thiols used as epoxy hardeners and the morphology of the supports on the catalytic properties of epoxy-supported palladium catalysts was discussed.
Dostawca treści:
Biblioteka Nauki
Artykuł

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