Abstract The adsorption of enantiomeric and racemic forms of methionine on the silver electrode s... more Abstract The adsorption of enantiomeric and racemic forms of methionine on the silver electrode surface was studied by surface–enhanced Raman scattering spectroscopy (SERS) as a function of pH value of the solution and the electrode potential, as well. Results for d –methionine were analogous to these for l -methionine, as expected. However, in the case of racemic mixture of d,l -methionine in acidic pH the spectral effects were different than those observed for monolayers built of pure enantiomer ( d or l ). This effect was discussed in terms of interplay between surface-molecule and intermolecular interactions between adjacent methionine molecules at the Ag surface.
The Vectron locomotives are a Siemens proposal covering locomotives dedicated to both passenger a... more The Vectron locomotives are a Siemens proposal covering locomotives dedicated to both passenger and freight traffic, capable of operating under a wide range of supply voltages (multi-system, single-system, etc. versions are offered), on both normal and broad-gauge track. A diesel version was also designed for operation on non-electrified lines. The Vectron locomotives are a variant of the Eurosprinter ones, developed in the early 1990s and enriched by the operation experience acquired, both on the German or Austrian railway network and in other EU countries (acceptance to operate as part of the liberalization of the common market). To date, circa 1,500 Eurosprinter locomotives have been sold, primarily in Europe and also in the USA, where they are operated in moderate climate, and both the Mediterranean one and the cold Scandinavian winters. Keywords: electric locomotives, multisystem voltage locomotives, Vectron, Siemens
Lokomotywy Vectron to propozycja koncernu Siemens obejmująca lokomotywy przeznaczone zarówno do o... more Lokomotywy Vectron to propozycja koncernu Siemens obejmująca lokomotywy przeznaczone zarówno do obsługi ruchu pasażerskiego, jak i towarowego, przystosowane do eksploatacji pod szerokim zakresem napięć zasilania (oferowana jest wersja wielosystemowa, jednosystemowa itp.), zarówno na torze normalnym, jak i szerokim. Zaprojektowano również wersję spalinową do eksploatacji na liniach niezelektryfikowanych. Lokomotywy Vectron stanowią rozwinięcie platformy Eurosprinter, powstałej na początku lat 90. oraz wzbogacanej o uzyskane doświadczenia eksploatacyjne, zarówno na sieci ko-lejowej Niemiec czy Austrii, jak i innych krajów należących do UE (swoboda prowadzenia przewozów w ramach liberalizacji wspólnego rynku). Dotychczas sprzedano ponad 1500 lokomotyw Vectron, przede wszystkim w Europie, a także w USA, gdzie są eksploatowane zarówno w warunkach klimatu śródziemnomorskiego, jak i mroźnych skandynawskich zim. Słowa kluczowe: lokomotywy elektryczne, lokomotywy wielosystemowe, Vectron, Sie...
W Polsce, w 2020 roku funkcjonowało dziesięciu producentów taboru kolejowego, będących zarówno po... more W Polsce, w 2020 roku funkcjonowało dziesięciu producentów taboru kolejowego, będących zarówno podmiotami polskimi (Pesa, Newag), jak i filiami obcych koncernów (Siemens, Bombardier, Alstom, Stadler). Podobny podział można uznać za umowny, ponieważ ww. filie zatrudniają w większości polskich specjalistów lub menedżerów i korzystają z polskich poddostawców, a polskie podmioty do produkcji używają w znacznej części komponentów importowanych. Obecnie produkowany jest tabor kolejowy w szerokim zakresie – od zespołów trakcyjnych po lokomotywy, z napędem elektrycznym i spalinowym, przystosowane do kursowania zarówno po torze normalnym, jak i szerokim. W polskich zakładach powstają także pociągi metra, w większości na eksport. W zamówieniach przewoźników na nowy tabor jest wykorzystywane dofinansowanie w ramach programów pomocowych UE. Słowa kluczowe: producenci taboru kolejowego, Polska, PKP
Celem tej pracy jest pokazanie, iz spektroskopia ramanowska, w tym zjawisko SERS, moze byc metodą... more Celem tej pracy jest pokazanie, iz spektroskopia ramanowska, w tym zjawisko SERS, moze byc metodą enancjoselektywną, tzn. metal pokryty filmem związku chiralnego (α-aminokwasu) bedzie mial zmienione widmo oscylacyjne przy porownywaniu jednego (bądź drugiego) enancjomeru aminokwasu z widmem mieszaniny racemicznej. Zatem aminokwasy (cysteina, fenyloalanina i metionina) byly adsorbowane na powierzchni metalu (srebra) w określonym czasie (monowarstwy SAM) lub z udzialem narzuconego potencjalu. Impulsem do zweryfikowania tezy, ze zjawisko powierzchniowego rozproszenia ramanowskiego (SERS) moze byc metodą enancjoselektywną, posluzyly wcześniej opublikowane w literaturze prace poświecone chiralnym powierzchniom, ktore badano nie tylko wykorzystując spektroskopie oscylacyjną, ale takze technike STM. Pojecie chiralnej powierzchni mozna określic jako strukture utworzoną przez związek chiralny stabilizowany przez wiązania wodorowe pomiedzy zaadsorbowanymi cząsteczkami. W tej pracy badano α-ami...
Abstract The tautomerism of 20 forms of diazinones was studied by the DFT and MP2 methods combine... more Abstract The tautomerism of 20 forms of diazinones was studied by the DFT and MP2 methods combined with the aug-cc-pVDZ basis set, and, for a few structures, at the CCSD/aug-cc-pVDZ level. The energy barriers were estimated for the most probable keto–enol and amine–imine equilibria and for all OH rotations. The stabilization of diazinones primarily depends on vicinity of the N-atoms and position of the external OH/ O group. The intramolecular interaction between heteroatomic groups additionally stabilized the lactam NH C O and enol N OH systems. Six diazinones is non-Kekulean and destabilized by over 24 kcal/mol. When DFT and MP2 calculations yielded vague results, the CCSD/aug-cc-pVDZ was used. Thus it was arbitrated that 3H-pirimidin-4-one is more stable than pirimidin-4-ol by as little as ca. 0.05 kcal/mol in agreement with experimental references; 1H-pirimidin-2-one is more stable than pirimidin-2-ol and 1H-pyrazin-2-one is more stable than pyrazin-2-ol by ca. 4 kcal/mol and ca. 2.4 kcal/mol, respectively. The barriers in the NH/NH, NH/OH tautomeric equilibria were predicted to exceed 45 and 30 kcal/mol, respectively, and the barriers for OH rotation to not exceed 9 kcal/mol. The keto–enol stabilization energy differences were shown to decrease monotonically with distance between the interaction centers and the second N-atom. Because, the localized C O bond enforces double bond localization, the HOMA aromaticity of keto forms is significantly smaller than that of the hydroxy tautomers. Our previous finding that the non-Kekulean tautomers exhibit aromaticity higher than the corresponding Kekulean forms with exactly one match was again well documented.
Ten rolling stock manufacturers were operating in Poland in 2020. These were both domestic enterp... more Ten rolling stock manufacturers were operating in Poland in 2020. These were both domestic enterprises (Pesa, Newag) as well as branches of foreign concerns (Siemens, Bombardier, Alstom, Stadler). A similar division can be deemed conventional since the aforementioned enterprises employ mostly Polish specialists or managers – and work with Polish subcontractors. On the other hand, Polish manufacturers use mainly imported components in the production process. The range of the currently manufactured rolling stock is quite wide – from multiple units to locomotives with electric and diesel drives, adapted to run on both standard and broad gauge tracks. Polish plants also manufacture underground train-sets, mostly for export. New rolling stock orders placed by operators are carried out with the support of EU funding programmes. Keywords: rolling stock manufacturers, Poland, PKP
The adsorption of both (L- and D-) enantiomeric forms of cysteine on the silver electrode surface... more The adsorption of both (L- and D-) enantiomeric forms of cysteine on the silver electrode surface was studied by surface-enhanced Raman scattering spectroscopy (SERS) as a function of electrode potential and pH value of the solution. It was demonstrated that at potentials more positive than -0.7 V (for pH 3) or -0.8 V (for pH 2 or lower), in acidic environment L-cysteine molecules are adsorbed mainly as P(H) (gauche) conformer, in zwitterionic form with the COO- groups close to the surface. At more negative potentials, NH3+ groups deprotonate at the surface with simultaneous weakening of the interaction of the carboxylic groups with the surface. Spectroscopic evidence for at least partial protonation of the COO- groups at strongly acidic solutions was given by observing the C=O stretching band at frequency lowered by about 30 cm(-1) in comparison with that observed for crystalline cysteine hydrochloride. It points to the considerable enhancement of the strength of hydrogen bonds and may be ascribed to the formation of cyclic L-cysteine dimers at the electrode surface. In neutral and alkaline solutions, adsorbed L-cysteine molecules have deprotonated amino groups at wide potential range. Similar spectroelectrochemical experiments were performed for D-cysteine and for a racemic mixture of D,L-cysteine. As expected, results for D-cysteine were similar to those for L-cysteine. However, for racemic mixture at acidic pH, the spectral effects corresponding to potential-induced transition from adsorbed zwitterions to neutral molecule were considerably smaller. This effect was discussed in terms of stereoselective dimerization of cysteine molecule at the electrode surface.
Abstract The adsorption of enantiomeric and racemic forms of methionine on the silver electrode s... more Abstract The adsorption of enantiomeric and racemic forms of methionine on the silver electrode surface was studied by surface–enhanced Raman scattering spectroscopy (SERS) as a function of pH value of the solution and the electrode potential, as well. Results for d –methionine were analogous to these for l -methionine, as expected. However, in the case of racemic mixture of d,l -methionine in acidic pH the spectral effects were different than those observed for monolayers built of pure enantiomer ( d or l ). This effect was discussed in terms of interplay between surface-molecule and intermolecular interactions between adjacent methionine molecules at the Ag surface.
The Vectron locomotives are a Siemens proposal covering locomotives dedicated to both passenger a... more The Vectron locomotives are a Siemens proposal covering locomotives dedicated to both passenger and freight traffic, capable of operating under a wide range of supply voltages (multi-system, single-system, etc. versions are offered), on both normal and broad-gauge track. A diesel version was also designed for operation on non-electrified lines. The Vectron locomotives are a variant of the Eurosprinter ones, developed in the early 1990s and enriched by the operation experience acquired, both on the German or Austrian railway network and in other EU countries (acceptance to operate as part of the liberalization of the common market). To date, circa 1,500 Eurosprinter locomotives have been sold, primarily in Europe and also in the USA, where they are operated in moderate climate, and both the Mediterranean one and the cold Scandinavian winters. Keywords: electric locomotives, multisystem voltage locomotives, Vectron, Siemens
Lokomotywy Vectron to propozycja koncernu Siemens obejmująca lokomotywy przeznaczone zarówno do o... more Lokomotywy Vectron to propozycja koncernu Siemens obejmująca lokomotywy przeznaczone zarówno do obsługi ruchu pasażerskiego, jak i towarowego, przystosowane do eksploatacji pod szerokim zakresem napięć zasilania (oferowana jest wersja wielosystemowa, jednosystemowa itp.), zarówno na torze normalnym, jak i szerokim. Zaprojektowano również wersję spalinową do eksploatacji na liniach niezelektryfikowanych. Lokomotywy Vectron stanowią rozwinięcie platformy Eurosprinter, powstałej na początku lat 90. oraz wzbogacanej o uzyskane doświadczenia eksploatacyjne, zarówno na sieci ko-lejowej Niemiec czy Austrii, jak i innych krajów należących do UE (swoboda prowadzenia przewozów w ramach liberalizacji wspólnego rynku). Dotychczas sprzedano ponad 1500 lokomotyw Vectron, przede wszystkim w Europie, a także w USA, gdzie są eksploatowane zarówno w warunkach klimatu śródziemnomorskiego, jak i mroźnych skandynawskich zim. Słowa kluczowe: lokomotywy elektryczne, lokomotywy wielosystemowe, Vectron, Sie...
W Polsce, w 2020 roku funkcjonowało dziesięciu producentów taboru kolejowego, będących zarówno po... more W Polsce, w 2020 roku funkcjonowało dziesięciu producentów taboru kolejowego, będących zarówno podmiotami polskimi (Pesa, Newag), jak i filiami obcych koncernów (Siemens, Bombardier, Alstom, Stadler). Podobny podział można uznać za umowny, ponieważ ww. filie zatrudniają w większości polskich specjalistów lub menedżerów i korzystają z polskich poddostawców, a polskie podmioty do produkcji używają w znacznej części komponentów importowanych. Obecnie produkowany jest tabor kolejowy w szerokim zakresie – od zespołów trakcyjnych po lokomotywy, z napędem elektrycznym i spalinowym, przystosowane do kursowania zarówno po torze normalnym, jak i szerokim. W polskich zakładach powstają także pociągi metra, w większości na eksport. W zamówieniach przewoźników na nowy tabor jest wykorzystywane dofinansowanie w ramach programów pomocowych UE. Słowa kluczowe: producenci taboru kolejowego, Polska, PKP
Celem tej pracy jest pokazanie, iz spektroskopia ramanowska, w tym zjawisko SERS, moze byc metodą... more Celem tej pracy jest pokazanie, iz spektroskopia ramanowska, w tym zjawisko SERS, moze byc metodą enancjoselektywną, tzn. metal pokryty filmem związku chiralnego (α-aminokwasu) bedzie mial zmienione widmo oscylacyjne przy porownywaniu jednego (bądź drugiego) enancjomeru aminokwasu z widmem mieszaniny racemicznej. Zatem aminokwasy (cysteina, fenyloalanina i metionina) byly adsorbowane na powierzchni metalu (srebra) w określonym czasie (monowarstwy SAM) lub z udzialem narzuconego potencjalu. Impulsem do zweryfikowania tezy, ze zjawisko powierzchniowego rozproszenia ramanowskiego (SERS) moze byc metodą enancjoselektywną, posluzyly wcześniej opublikowane w literaturze prace poświecone chiralnym powierzchniom, ktore badano nie tylko wykorzystując spektroskopie oscylacyjną, ale takze technike STM. Pojecie chiralnej powierzchni mozna określic jako strukture utworzoną przez związek chiralny stabilizowany przez wiązania wodorowe pomiedzy zaadsorbowanymi cząsteczkami. W tej pracy badano α-ami...
Abstract The tautomerism of 20 forms of diazinones was studied by the DFT and MP2 methods combine... more Abstract The tautomerism of 20 forms of diazinones was studied by the DFT and MP2 methods combined with the aug-cc-pVDZ basis set, and, for a few structures, at the CCSD/aug-cc-pVDZ level. The energy barriers were estimated for the most probable keto–enol and amine–imine equilibria and for all OH rotations. The stabilization of diazinones primarily depends on vicinity of the N-atoms and position of the external OH/ O group. The intramolecular interaction between heteroatomic groups additionally stabilized the lactam NH C O and enol N OH systems. Six diazinones is non-Kekulean and destabilized by over 24 kcal/mol. When DFT and MP2 calculations yielded vague results, the CCSD/aug-cc-pVDZ was used. Thus it was arbitrated that 3H-pirimidin-4-one is more stable than pirimidin-4-ol by as little as ca. 0.05 kcal/mol in agreement with experimental references; 1H-pirimidin-2-one is more stable than pirimidin-2-ol and 1H-pyrazin-2-one is more stable than pyrazin-2-ol by ca. 4 kcal/mol and ca. 2.4 kcal/mol, respectively. The barriers in the NH/NH, NH/OH tautomeric equilibria were predicted to exceed 45 and 30 kcal/mol, respectively, and the barriers for OH rotation to not exceed 9 kcal/mol. The keto–enol stabilization energy differences were shown to decrease monotonically with distance between the interaction centers and the second N-atom. Because, the localized C O bond enforces double bond localization, the HOMA aromaticity of keto forms is significantly smaller than that of the hydroxy tautomers. Our previous finding that the non-Kekulean tautomers exhibit aromaticity higher than the corresponding Kekulean forms with exactly one match was again well documented.
Ten rolling stock manufacturers were operating in Poland in 2020. These were both domestic enterp... more Ten rolling stock manufacturers were operating in Poland in 2020. These were both domestic enterprises (Pesa, Newag) as well as branches of foreign concerns (Siemens, Bombardier, Alstom, Stadler). A similar division can be deemed conventional since the aforementioned enterprises employ mostly Polish specialists or managers – and work with Polish subcontractors. On the other hand, Polish manufacturers use mainly imported components in the production process. The range of the currently manufactured rolling stock is quite wide – from multiple units to locomotives with electric and diesel drives, adapted to run on both standard and broad gauge tracks. Polish plants also manufacture underground train-sets, mostly for export. New rolling stock orders placed by operators are carried out with the support of EU funding programmes. Keywords: rolling stock manufacturers, Poland, PKP
The adsorption of both (L- and D-) enantiomeric forms of cysteine on the silver electrode surface... more The adsorption of both (L- and D-) enantiomeric forms of cysteine on the silver electrode surface was studied by surface-enhanced Raman scattering spectroscopy (SERS) as a function of electrode potential and pH value of the solution. It was demonstrated that at potentials more positive than -0.7 V (for pH 3) or -0.8 V (for pH 2 or lower), in acidic environment L-cysteine molecules are adsorbed mainly as P(H) (gauche) conformer, in zwitterionic form with the COO- groups close to the surface. At more negative potentials, NH3+ groups deprotonate at the surface with simultaneous weakening of the interaction of the carboxylic groups with the surface. Spectroscopic evidence for at least partial protonation of the COO- groups at strongly acidic solutions was given by observing the C=O stretching band at frequency lowered by about 30 cm(-1) in comparison with that observed for crystalline cysteine hydrochloride. It points to the considerable enhancement of the strength of hydrogen bonds and may be ascribed to the formation of cyclic L-cysteine dimers at the electrode surface. In neutral and alkaline solutions, adsorbed L-cysteine molecules have deprotonated amino groups at wide potential range. Similar spectroelectrochemical experiments were performed for D-cysteine and for a racemic mixture of D,L-cysteine. As expected, results for D-cysteine were similar to those for L-cysteine. However, for racemic mixture at acidic pH, the spectral effects corresponding to potential-induced transition from adsorbed zwitterions to neutral molecule were considerably smaller. This effect was discussed in terms of stereoselective dimerization of cysteine molecule at the electrode surface.
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