Catalysts for ultrahigh current density oxygen cathodes for space fuel cell applications

The objective was to identify promising electrocatalyst/support systems for oxygen cathodes capable of operating at ultrahigh current densities in alkaline fuel cells. Such cells will require operation at relatively high temperatures and O2 pressures. A number of materials were prepared, including Pb-Ru and Pb-Ir pyrochlores, RuO2 and Pt-doped RuO2, lithiated NiO and La-Ni perovskites. Several of these materials were prepared using techniques that had not been previously used to prepare them. Particularly interesting was the use of the alkaline solution technique to prepare Pt-doped and Pb-Ru pyrochlores in high area form. Also interesting was the use of the fusion (melt) method for preparing the Pb-Ru pyrochlore. Several of the materials were also deposited with platinum. Well-crystallized Pb2Ru2O(7-y) was used to fabricate very high performance O2 cathodes with good stability in room temperature KOH. This material was also found to be stable over a useful potential range at approx. 140 C in concentrated KOH. For some of the samples, fabrication of the gas-fed electrodes could not be fully optimized during this project period. Future work may be directed at this problem. Pyrochlores that were not well-crystallized were found to be unstable in alkaline solution. Very good O2 reduction performance and stability were observed with Pb2RuO(7-y) in a carbon-based gas-fed electrode with an anion-conducting membrane placed on the electrolyte side of the electrode. The performance came within a factor of about two of that observed without carbon. High area platinum and gold supported on several conductive metal oxide supports were examined. Only small improvements in O2 reduction performance at room temperature were observed for Pb2Ru2O(7-y) as a support because of the high intrinsic activity of the pyrochlore. In contrast, a large improvement was observed for Li-doped NiO as a support for Pt. Very poor performance was observed for Au deposited on Li-NiO at approx. 150 C. Nearly reversible behavior was observed for the O2/OH(-) couple for Li-doped NiO at approx. 200 C. The temperature dependence for the O2 reduction was examined

Electrocatalysis for oxygen electrodes in fuel cells and water electrolyzers for space applications

In most instances separate electrocatalysts are needed to promote the reduction of O2 in the fuel cell mode and to generate O2 in the energy storage-water electrolysis mode in aqueous electrochemical systems operating at low and moderate temperatures (T greater than or equal to 200 C). Interesting exceptions are the lead and bismuth ruthenate pyrochlores in alkaline electrolytes. These catalysts on high area carbon supports have high catalytic activity for both O2 reduction and generation. Rotating ring-disk electrode measurements provide evidence that the O2 reduction proceeds by a parallel four-electron pathway. The ruthenates can also be used as self-supported catalysts to avoid the problems associated with carbon oxidation, but the electrode performance so far achieved in the research at Case Western Reserve University (CWRU) is considerably less. At the potentials involved in the anodic mode the ruthenate pyrochlores have substantial equilibrium solubility in concentrated alkaline electrolyte. This results in the loss of catalyst into the bulk solution and a decline in catalytic activity. Furthermore, the hydrogen generation counter electrode may become contaminated with reduction products from the pyrochlores (lead, ruthenium)

Catalysts for ultrahigh current density oxygen cathodes for space fuel cell applications

The objective of this research was to identify promising electrocatalyst/support systems for the oxygen cathode in alkaline fuel cells operating at relatively high temperatures, O2 pressures and current densities. A number of materials were prepared, including Pb-Ru and Pb-Ir pyrochlores, RuO2 and Pt-doped RuO2, and lithiated NiO. Several of these were prepared using techniques that had not been previously used to prepare them. Particularly interesting is the use of the alkaline solution technique to prepare the Pt-doped Pb-Ru pyrochlore in high area form. Well-crystallized Pb(2)Ru(2)O(7-y) was used to fabricate high performance O2 cathodes with relatively good stability in room temperature KOH. This material was also found to be stable over a useful potential range at approximately 140 C in concentrated KOH. Other pyrochlores were found to be either unstable (amorphous samples) or the fabrication of the gas-fed electrodes could not be fully optimized during this project period. Future work may be directed at this problem. High area platinum supported on conductive metal oxide supports produced mixed results: small improvements in O2 reduction performance for Pb(2)Ru(2)O(7-y) but a large improvement for Li-doped NiO at room temperature. Nearly reversible behavior was observed for the O2/OH couple for Li-doped NiO at approximately 200 C

Perovskite oxides: Oxygen electrocatalysis and bulk structure

Perovskite type oxides were considered for use as oxygen reduction and generation electrocatalysts in alkaline electrolytes. Perovskite stability and electrocatalytic activity are studied along with possible relationships of the latter with the bulk solid state properties. A series of compounds of the type LaFe(x)Ni1(-x)O3 was used as a model system to gain information on the possible relationships between surface catalytic activity and bulk structure. Hydrogen peroxide decomposition rate constants were measured for these compounds. Ex situ Mossbauer effect spectroscopy (MES), and magnetic susceptibility measurements were used to study the solid state properties. X ray photoelectron spectroscopy (XPS) was used to examine the surface. MES has indicated the presence of a paramagnetic to magnetically ordered phase transition for values of x between 0.4 and 0.5. A correlation was found between the values of the MES isomer shift and the catalytic activity for peroxide decomposition. Thus, the catalytic activity can be correlated to the d-electron density for the transition metal cations

EFFECT OF THE NUMBER OF REARING KITS ON SELECTED PARAMETERS IN BLOOD OF POLAR FOXES FEMALE

The aim of the research was to determine the effect of the number of rearing kits on selected blood parameters in polar fox females in the fifth week of lactation. The haematological parameters were tested in the blood of polar fox females with small (group A-mean number of pups: 3.5) and large (group B-mean number of pups: 10.7) litter. In female polar foxes rearing 9-13 kits (group B) there was found a lower number of red blood cells, a lower haematocrit value and lower concentration of haemoglobin. No significant (P<0.05) effect of litter size on the number of white blood cells was observed, however there was an essential (P<0.05) increase in the percentage of neutrophiles as well as lowering of lymphocytes in the total count of leucocytes in the female of polar foxes from B group. A large number of pups in litter significantly (P<0.05) lowered the content of glucose in female blood on the 35th day of lactation

FORMACJA KLERYKÓW DO POSŁUGI CHARYTATYWNEJ W ŚWIETLE PROJEKTU NOWEGO RATIO INSTITUTIONIS SACERDOTALIS PRO POLONIA

Posługa charytatywna należy do istotnej działalności Kościoła. Realizowano ją już od czasów apostolskich. Potrzebę budzenia wrażliwości na ludzką biedę i rozwijania różnych form docierania do osób potrzebujących w działalności duszpasterskiej mocno akcentuje papież Franciszek. Ważne jest, aby przyszli duszpasterze nie tylko dobrze znali naturę i misję Kościoła, ale także byli dobrze przygotowani do czekających ich zadań. Powyższe kwestie względem osób objętych formacją seminaryjną uwzględnia projekt nowego Ratio institutionis sacerdotalis pro Polonia, który obecnie oczekuje na zatwierdzenie przez Stolicę Apostolską. W przygotowanym dokumencie znajdują się ważne wytyczne dotyczące formacji seminarzystów do postawy służby oraz dotyczące ich przyszłej działalności charytatywnej w podejmowanej posłudze duszpasterskiej na wzór Jezusa Sługi i Dobrego Pasterza

ECCLESIASTIC LOVE IN EVANGELISATION

Evangelisation is an important part of the Church’s mission and its aim is to bring man to meet with God the Saviour. Preaching the Gospel cannot be reduced to words, but it requires testimony in the form of deeds. Acts of love, for which the best source is the conduct of Jesus, described in the Gospels, are the most credible. The Church not only tries to imitate Jesus, but also to make Him present in God’s words that it preaches and in the ministry of charity. The truth of His infinite love is the most important truth that it communicates to the faithful. Therefore, evangelisation is always a form of communicating God’s love. The testimony of the faith in Christ, confirmed by acts of love, is extremely convincing and clear. Therefore, evangelical activities of the Church must always include Christian caritas, i.e. ministration to the needy

Hematologiczne i biochemiczne parametry krwi koni użytkowanych sportowo i rekreacyjnie

The study was conducted to determine and compare the resting values of haematological and biochemical blood indices in clinically healthy horses competing in show jumping and used for leisure activities. The experiment included twenty adult horses of Polish half-bred and Wielkopolska breed which were subjected to a daily training programme typical of their type of use. Blood samples were collected at rest before feeding from the jugular external vein. Show jumpers had higher (P < 0.05) red blood cell count, haematocrit value and haemoglobin concentration as well as the serum level of total protein, albumin, α2- and γ-globulin, HDL and iron. The level of β-globulin, magnesium and activity of creatine kinase were significantly higher in recreationally used horses. There were no differences in the values of red blood cell parameters (MCV, MCH, MCHC), number of leucocytes and the percentage of their respective kinds, platelets, concentration of urea, creatinine, glucose, triglycerides, total cholesterol, LDL, activity of AST, ALT, LDH and in the content of Na, K, Cl, P, Ca between the tested groups. The results of the present study indicate that the type of training influences some of the resting haematological and biochemical indices in adult horses. Horses used for show jumping have higher aerobic capacity and show a more beneficial lipid profile compared to horses used for recreation.Celem badań było określenie i porównanie spoczynkowych wartości wskaźników hematologicznych i biochemicznych krwi u koni biorących udział w zawodach skokowych i koni użytkowanych rekreacyjnie. Badania przeprowadzono na 20 dorosłych, klinicznie zdrowych koniach rasy wielkopolskiej oraz polskich koniach szlachetnych półkrwi. Konie poddawano codziennemu programowi treningowemu, odpowiadającemu rodzajowi ich użytkowania. Krew do badań pobrano w spoczynku w godzinach rannych przed karmieniem, z żyły szyjnej zewnętrznej. U koni użytkowanych sportowo w pełnej krwi stwierdzono wyższą (P < 0,05) liczbę krwinek czerwonych, wartość hematokrytu i koncentrację hemoglobiny, jak również wyższy poziom białka całkowitego, albumin, α2- i γ-globulin, HDL i żelaza w surowicy krwi. Poziom β-globulin, magnezu i aktywność kinazy kreatynowej były istotnie wyższe u koni użytkowanych rekreacyjnie. Nie odnotowano istotnych różnic w wartościach parametrów czerwonokrwinkowych (MCV, MCH, MCHC), liczbie leukocytów i udziale procentowym poszczególnych form krwinek białych w ogólnej ich ilości oraz liczbie płytek krwi jak również w koncentracji mocznika, kreatyniny, glukozy, triglicerydów, cholesterolu całkowitego, frakcji LDL oraz aktywności AST, ALT, LDH i zawartości Na, K, Cl, P, Ca pomiędzy badanymi grupami. Wyniki badań wskazują, że rodzaj stosowanego treningu wpływa na spoczynkowe wartości hematologiczne i biochemiczne krwi dorosłych koni. Konie wykorzystywane w skokach przez przeszkody charakteryzują się lepszą wydolnością tlenową i korzystniejszym profilem lipidowym krwi w porównaniu do koni użytkowanych rekreacyjnie

WPŁYW LICZBY ODCHOWYWANYCH SZ CZENIĄT NA WYBRANE WSKAŹNIKI KRWI LISIC POLARNYCH

The aim of the research was to determine the effect of the number of rearing kits on selected blood parameters in polar fox females in the fifth week of lactation. The haematological parameters were tested in the blood of polar fox females with small (group A-mean number of pups: 3.5) and large (group B-mean number of pups: 10.7) litter. In female polar foxes rearing 9-13 kits (group B) there was found a lower number of red blood cells, a lower haematocrit value and lower concentration of haemoglobin. No significant (P<0.05) effect of litter size on the number of white blood cells was observed, however there was an essential (P<0.05) increase in the percentage of neutrophiles as well as lowering of lymphocytes in the total count of leucocytes in the female of polar foxes from B group. A large number of pups in litter significantly (P<0.05) lowered the content of glucose in female blood on the 35th day of lactation.Celem badań było określenie wpływu liczby odchowywanych szczeniąt w miocie na wybrane parametry krwi lisic polarnych w piątym tygodniu laktacji. Wskaźniki hematologiczne określono w krwi lisic odchowujących małe (grupa A - średnia liczba szczeniąt: 3,5) i liczne (grupa B – średnia liczba szczeniąt: 10,7) mioty. U samic odchowujących 9- 13 szczeniąt (grupa B) stwierdzono mniejszą liczbę erytrocytów, niższą wartość hematokrytu i mniejszą koncentrację hemoglobiny w krwi. Nie stwierdzono istotnego (P<0,05) wpływu wielkości miotu na ogólną liczbę krwinek białych, odnotowano natomiast istotny (P<0,05) wzrost procentowego udziału neutrocytów oraz obniżenie procentowego udziału limfocytów w krwi lisic z grupy B. W 35-tym dniu laktacji w krwi samic karmiących liczne mioty stwierdzono również istotnie (P<0,05) mniejszą zawartość glukozy

In situ detection of dopamine using nitrogen incorporated diamond nanowire electrode

[[abstract]]Significant difference was observed for the simultaneous detection of dopamine (DA), ascorbic acid (AA), and uric acid (UA) mixture using nitrogen incorporated diamond nanowire (DNW) film electrodes grown by microwave plasma enhanced chemical vapor deposition. For the simultaneous sensing of ternary mixtures of DA, AA, and UA, well-separated voltammetric peaks are obtained using DNW film electrodes in differential pulse voltammetry (DPV) measurements. Remarkable signals in cyclic voltammetry responses to DA, AA and UA (three well defined voltammetric peaks at potentials around 235, 30, 367 mV for DA, AA and UA respectively) and prominent enhancement of the voltammetric sensitivity are observed at the DNW electrodes. In comparison to the DPV results of graphite, glassy carbon and boron doped diamond electrodes, the high electrochemical potential difference is achieved via the use of the DNW film electrodes which is essential for distinguishing the aforementioned analytes. The enhancement in EC properties is accounted for by increase in sp2 content, new C–N bonds at the diamond grains, and increase in the electrical conductivity at the grain boundary, as revealed by X-ray photoelectron spectroscopy and near edge X-ray absorption fine structure measurements. Consequently, the DNW film electrodes provide a clear and efficient way for the selective detection of DA in the presence of AA and UA.[[booktype]]紙