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Search Results: 1 - 10 of 543 matches for " Iwona Kowalczyk "
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Synthesis, Molecular Structure and Spectral Properties of Quaternary Ammonium Derivatives of 1,1-Dimethyl-1,3-propylenediamine
Iwona Kowalczyk
Molecules , 2008, DOI: 10.3390/molecules13020379
Abstract: 1,1-Dimethyl-3-oxo-1,4-diazepan-1-ium chloride (1) and 1,1-dimethyl-1-carboxymethyl-3-aminopropyl ammonium hydrochloride (2) have been obtained by thereactions of 1,1-dimethyl-1,3-propylenediamine with ethyl chloroacetate and chloroaceticacid, respectively. The products have been characterized by FTIR, Raman and NMRspectroscopy. B3LYP calculations have also been carried out. The screening constants for 13C- and 1H- atoms have been calculated by the GIAO/B3LYP/6-31G(d,p) approach andanalyzed. The FTIR and NMR spectra of the investigated compounds 1 and 2 are inexcellent agreement with the structures optimized by Density Functional Theory (DFT)calculations.
Synthesis and Structural Analysis of Novel Norspermidine Derivatives  [PDF]
Bogumi? Brycki, Iwona Kowalczyk, Justyna Werner, Tomasz Pospieszny, Anna Kozirog
International Journal of Organic Chemistry (IJOC) , 2017, DOI: 10.4236/ijoc.2017.72010
Abstract: A series of new norspermidine derivatives, both nonionic and cationic, have been obtained. Structures of the synthesized compounds have been estab-lished by FTIR, 1H NMR, 13C NMR, 2D NMR, mass spectrometry and elemental analyses. Physicochemical and anti-microbial properties have been discussed.
Study of Cyclic Quaternary Ammonium Bromides by B3LYP Calculations, NMR and FTIR Spectroscopies
Bogumi? Brycki,Adrianna Szulc,Iwona Kowalczyk
Molecules , 2010, DOI: 10.3390/molecules15085644
Abstract: N,N-dioctyl-azepanium, -piperidinium and -pyrrolidinium bromides 1-3, have been obtained and characterized by FTIR and NMR spectroscopy. DFT calculations have also been carried out. The optimized bond lengths, bond angles and torsion angles calculated by B3LYP/6-31G(d,p) approach have been presented. Both FTIR and Raman spectra of 1-3 are consistent with the calculated structures in the gas phase. The screening constants for 13C and 1H atoms have been calculated by the GIAO/B3LYP/6-31G(d,p) approach and analyzed. Linear correlations between the experimental 1H and 13C chemical shifts and the computed screening constants confirm the optimized geometry.
Synthesis, Molecular Structure, Spectral Properties and Antifungal Activity of Polymethylene-α,ω-bis(N,N- dimethyl-N-dodecyloammonium Bromides)
Bogumil Brycki,Iwona Kowalczyk,Anna Kozirog
Molecules , 2011, DOI: 10.3390/molecules16010319
Abstract: Hexamethylene-1,6-bis-(N,N-dimethyl-N-dodecylammonium bromide) (1), pentamethylene-1,5-bis(N,N-dimethyl-N-dodecylammonium bromide) (2), tetramethylene-1,4-bis(N,N-dimethyl-N-dodecylammonium bromide) (3), trimethylene-1,3-bis(N,N-dimethyl-N-dodecylammonium bromide) (4) and ethylene-1,2-bis(N,N-dimethyl-N-dodecylammonium bromide) (5) have been obtained and characterized by FTIR and NMR spectroscopy. DFT calculations have also been carried out. The optimized bond lengths, bond angles and torsion angles calculated by Hartree-Fock/3-21G(d,p) approach have been presented. MIC values for A. niger, P. chrysogenum, C. albicans have been determined and the relationship between MIC and spacer length has been discussed.
Ocena czynników wp ywaj cych na nawrót dolegliwo ci po rozpocz ciu ywienia doustnego u chorych z ostrym zapaleniem trzustki
Janusz Ciok,Jan Dzieniszewski,Iwona Kowalczyk,El?bieta Dr??kiewicz
Polish Gastroenterology , 2003,
Abstract: Wprowadzenie: U niektórych chorych z ostrym zapaleniem trzustki (o.z.t.) po wdro eniu ywienia doustnego stwierdza si nawrót bólu i ponowny wzrost aktywno ci alfa-amylazy. Cel pracy: Obserwacja grupy chorych z o.z.t. w celu oceny cz sto ci wyst powania tego powik ania oraz wykrycia czynników do niego predysponuj cych. Materia i metody: Oceniono 74 parametry kliniczne u 214 chorych z o.z.t. kolejno hospitalizowanych w naszym o rodku. Porównywano cz sto wyst powania tych parametrów w grupie chorych, u których dosz o do nawrotu bólu po rozpocz ciu ywienia doustnego w porównaniu do grupy chorych bez nawrotu bólu. Wyniki: Nawrót bólu po rozpocz ciu ywienia doustnego wyst pi u 41 chorych (19%) a u kolejnych 52 chorych (24%) stwierdzono wzrost aktywno ci alfa-amylazy. Nie by o istotnych ró nic w ocenie ci ko ci choroby pomi dzy grup z nawrotem bólu i bez nawrotu bólu mierzonej za pomoc skali Ransona. Ró nice statystycznie znamienne wyst pi y w odniesieniu do wysokiego poziomu CRP (powyoej 120 mg/dl) - odpowiednio 24 i 16%, OB powy ej 20 mm (25 i 18%) oraz obecno ci pseudotorbieli (76 i 22%) i ropni trzustki (6 i 2%). W grupie chorych z nawrotem bólu cz ciej wykonywano badanie ultrasonograficzne jamy brzusznej (odpowiednio 2,94 i 2,28 badania/przypadek) oraz tomografi komputerow jamy brzusznej (1,23 i 0,67/przypadek). Okres hospitalizacji by d u szy w grupie chorych z nawrotem bólu (18,9 i 13,7 dni). Wnioski: Nawrót bólu po wdro eniu ywienia doustnego stwierdzono u 19% chorych z ostrym zapaleniem trzustki. U wi kszo ci chorych z nawrotem bólu stwierdzono obecno pseudotorbieli (76%) lub ropni trzustki (7%). Chorzy z nawrotem bólu charakteryzowali si d u szym czasem hospitalizacji oraz wi ksz cz sto ci wykonywania badania USG i TK jamy brzusznej.
Synthesis, Spectroscopic and Semiempirical Studies of New Quaternary Alkylammonium Conjugates of Sterols
Bogumi? Brycki,Hanna Koenig,Iwona Kowalczyk,Tomasz Pospieszny
Molecules , 2013, DOI: 10.3390/molecules181214961
Abstract: New quaternary alkylammonium conjugates of steroids were obtained by two step reaction of sterols (ergosterol, cholesterol, dihydrocholesterol) with bromoacetic acid bromide, followed by bimolecular nucleophilic substitution with a long chain tertiary alkylamine. The structures of products were con?rmed by spectral ( 1H-NMR, 13C-NMR, and FT-IR) analysis, mass spectrometry and PM5 semiempirical methods. The pharmacotherapeutic potential of synthesized compounds has been estimated on the basis of Prediction of Activity Spectra for Substances (PASS).
Implementation of Acoustic Analogies in OpenFOAM for Computation of Sound Fields  [PDF]
J. Schmalz, W. Kowalczyk
Open Journal of Acoustics (OJA) , 2015, DOI: 10.4236/oja.2015.52004
Abstract: In this work the turbulence based acoustic sources and the corresponding wave propagation of fluctuating flow values in incompressible fluid flows are considered. Lighthill’s and Curle’s acoustic analogies are implemented in the open source computational fluid dynamics framework OpenFOAM. The main objective of this work is to visualize and localize the dominated sound sources and the resulting values of fluctuating pressure values within the computation domain representing the acoustical near field. This is all done on one mesh and during the iterative computation of the transient fluid flow. Finally the flow field and acoustical results of different simulation cases are presented and the properties of the shown method are discussed.
‘Mountain resorts’: origins and evolution
Andrzej Kowalczyk
Tourism , 2009, DOI: 10.2478/V10106-009-0004-y
Abstract: The paper discusses the background for the emergence of such ‘mountain resorts’, their types and changes in their mode of operation. Some theoretical and practical issues will be illustrated with examples derived from Europe, North America, Asia and Africa.
Proton induced spallation reactions in the energy range 0.1 - 10 GeV
Anna Kowalczyk
Physics , 2008,
Abstract: One of considered nowadays scenarios of proton - nucleus reaction is spallation. Its motivation is based on experimental final-state observations of one heavy nucleus, a small number of light fragments and numerous individual nucleons. It is theoretically described as two step process involving energy deposition in the target nucleus and subsequent evaporation. Several models, based on different assumptions, have been constructed in order to describe the spallation process. The main subject of this work is description of global average properties of proton induced spallation reactions in wide range of projectile energy (0.1 - 10 GeV) and mass of target nuclei. This is investigated within Hadron String Dynamics (HSD) model, based on Boltzmann - Uehling - Uhlenbeck (BUU) equation, supplemented by a statistical evaporation model for the second stage of the reaction. It has been shown that spallation is the most probable scenario of proton - nucleus reaction. Proton induced reactions, in considered here incident energy range, are visibly non-invasive processes. Properties of residual nuclei after the first stage of the reaction are weakly dependent on incident energy, but strongly dependent on mass of target. The second stage of the reaction is a competition of evaporation and fission. Results obtained from the HSD model vary smoothly as function of proton incident energy and mass of target, so interpolation of the results is quite feasible.
Hypersurfaces M^n in S^k x H^n-k+1
Daniel Kowalczyk
Mathematics , 2009,
Abstract: Let $\psi:\M \to \SH$ be an isometric immersion of codimension 1, then there exist symmetric $(1,1)$-tensors $S$ and $f$, a tangent vector field $U$ and a smooth function $\lambda$ on $\M$ that satisfy the compatibility equations of $\SH$. In this paper, we will deal with the converse problem: "Given a Riemannian manifold $\M$ with symmetric $(1,1)$-tensors $S$ and $f$, tangent vector field $U$ and smooth function $\lambda$ satisfying the conditions mentioned above, can $\M$ then be isometrically immersed in $\SH$ in such a way that $(g,S,f,U,\lambda)$ is realized as the induced structure?".
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