Mixed Ion-Polaron Glasses as New Cathode Materials

Electrical transport in mixed ion-polaron glasses has been investigated in four series of glasses containing transition metal oxides (TMO) namely WO3/MoO3, and Na+/Ag+ ions with the composition xWO3- (30-0.5x)Na2O-(30-0.5x)ZnO-40P2O5, xWO3-(30- 0.5x)Ag2O-(30-0.5x)ZnO-40P2O5, xMoO3-(30-0.5x)Na2O- (30-0.5x)ZnO-40P2O5, and xMoO3-(30-0.5x)Ag2O-(30- 0.5x)ZnO-40P2O5, 0 ≤ x ≤ 60 (mol%). The DC conductivity of Na-glasses up to 30 mol% of WO3 and MoO3 is almost identical due to the dominance of ionic conductivity. In this compositional region, the introduction of tungstate and molybdate units increases the mobility of sodium ions and compensates the decrease in sodium number density. On the other hand, with increasing WO3 and MoO3 content and decreasing Ag+ ion concentration in Ag-glasses the DC conductivity decreases for few orders of magnitude. A significant difference in conductivity is observed for glasses with higher WO3 and MoO3 content. While for glasses containing WO3 the conductivity rapidly increases due to a huge polaronic contribution indicating a turnover from predominantly ionic to polaronic transport, the conductivity for MoO3- glasses decreases in the entire mixed compositional range suggesting dominant ionic transport. The changes in the conduction mechanism with the systematic alternation of the glass composition have been analyzed in correlation with the structural modifications and variations of molybdenum and tungsten in different oxidation states

Structure-Property Correlation in Sodium Borophosphate Glasses Modified with Niobium Oxide

Bulk glasses of the series (100−x)[0.4Na2O-0.2Nb2O5-0.4P2O5]-xB2O3 with x = 0–48 mol% B2O3 were prepared by slow cooling in air. Their glass transition temperature increases within the range of 0–16 mol% B2O3, but further additions of B2O3 result in its decrease. Their structure was investigated by Raman, 11B, and 31P MAS NMR spectroscopy. The relative number of BO4 units decreases with increasing B2O3 content, while the number of BO3 units increases up to 59 % at x = 48. The upfield shift of a broad resonance peak in the 31P MAS NMR spectra is ascribed to an increasing connectedness of the structural network with increasing B2O3 content. A strong Raman band at 916–929 cm−1 shows the presence of NbO6 octahedra in the structural network of these glasses. With the B2O3 addition, a decrease in DC conductivity is observed, which is attributed to the decrease in the concentration of Na+ ions

Sodium-Ion Conductivity and Humidity-Sensing Properties of Na2O-MoO3-P2O5 Glass-Ceramics

A series of glass-ceramics were prepared by heat- treatments of 40Na2O-30MoO3-30P2O5 (in mol%) glass in a temperature range from 380 (Tg) to 490 °C (Tc) and for 1–24 h. The prepared glass-ceramics contain from 2 to 25 wt.% of crystalline NaMoO2PO4. The sodium-ion conductivity in these materials decreases up to one order of magnitude with an increase in the degree of crystallization due to the immobilization of sodium ions in crystalline NaMoO2PO4. The transport of sodium ions in these materials occurs primarily through the dominant continuous glassy phase, and it is weakly affected by the sporadically distributed crystalline grains. However, the prepared glassceramics exhibit high proton conductivity in a humid atmosphere and remarkable humidity-sensing properties ; this could be related to crystalline NaMoO2PO4, which provides sites for water adsorption. The glass-ceramic prepared at 450 °C for 24 h shows the best humidity-sensing performance among all samples, showing an increase in proton conductivity for more than seven orders of magnitude with the increase in relative humidity from 0% to 95%. Under a highly humid atmosphere (95% relative humidity and 25 °C), the proton conductivity of this glass-ceramic reaches 5.2 ×10−3 (Ω cm)−1. Moreover, the electrical response of these materials on the change in the relative humidity is linear and reversible in the entire range of the relative humidity, which indicates that they are novel promising candidates for application as humidity sensors

Skelné a krystalické materiály na bázi fosforečnanů a borofosforečnanů kovů

Práce je rozčleněna do tří v podstatě nezáviských celků, které spolu souvisí: 1. Studium struktury a fyzikálně-chemických vlastností uvedených skel 2. Studium termického chování a mechanismu krystalizace skel 3. Studium korozně-inhibičních vlastností materiálů na bázi borofosforečnanů.Katedra obecné a anorganické chemieDokončená práce s úspěšnou obhajobo

Kondenzované fosforečnany jako nové antikorozní pigmenty

Katedra anorganické technologieDokončená práce s úspěšnou obhajobo

Duty of confidentiality in pre-hospital emergency care

Tato práce se zabývá problematikou zneužívání a úniku citlivých dat, které se nabyly v rámci poskytování zdravotních služeb, v tomto případě práce cílí konkrétně na přednemocniční neodkladnou péči a zasazuje ji do prostředí zdravotnické záchranné služby. Teoretická část zahrnuje definici tématu, historii, právo na informace o zdravotním stavu pacienta, poodhaluje, za jakých okolností lze povinnou mlčenlivost porušit a zaobírá se postihem za prokázané porušení tohoto práva. Praktická část byla postavena na dotazníkovém šetření, které obsahovalo vědomostní otázky stahující se na povinnou mlčenlivost v PNP. Cílem praktické části bylo zjistit úroveň znalostí týkajících se tohoto tématu, zda zdravotničtí pracovníci dokážou řešit tento problém v terénní práci, popis a analýza odpovědí dotazníkové průzkumu z hlediska stupně vzdělání, délky praxe a profesní pozice u ZZS.This work deals with the issue of misuse and leakage of sensitive data, which were acquired in the provision of health services; in this case the work specifically targets pre-hospital emergency care and places it in the environment of the emergency medical service. The theoretical part includes the definition of the topic, history, the right to information about the patient's health, reveals the circumstances in which mandatory confidentiality may be violated and deals with the penalty for proven violation of this right. The practical part was based on a questionnaire survey, which contained knowledge questions related to mandatory confidentiality in pre-hospital emergency care. The aim of the practical part was to find out the level of knowledge related to this topic, and whether health professionals can solve this problem in field work.Fakulta zdravotnických studiíDoplňující otázky od oponenta: 1. Jak by zněly průzkumné otázky ve Vaší bakalářské práci? 2. Z jakého důvodu rozdávala na ZZS dotazníky jiná osoba než autor? Obhajoba bakalářské práce s prezentací dobrá.Dokončená práce s úspěšnou obhajobo

Kinetics and mechanism of crystallization of borophosphate glasses of the ZnO-B2O3-P2O5 system

Borophosphate glasses of the ZnO-B2O3-P2O5 system were prepared by cooling the melt from 1230 °C. Their crystallization was studied by DSC and X-ray diffraction. The crystallization takes place mostly at 600-800 °C giving at least two crystalline phases with BPO4 as one of the products. The kinetics of the crystallization of borophosphate glass 58.3ZnO-8.3B2O3-33.4P2O5 can be describede be the Šesták-Berggren model, while that of 50ZnO-50B2O3 is better described by the Johnson-Mehl Avrami model. The analysis of the shape and position of the crystallization peak for different sizes of glass powders lead to the conclusion that surface crystallization prevails for the borophosphate glass, While for the borate glass surface crystallization dominates only when the particle size is under 300 um, but internal crystallization prevails in the bulk glass

Termické chování a vlastnosti skel systému BaO-B2O3-P2O5

Borophosphate glasses of the BaO-B2O3-P2O5 ternary system were prepared and studied within the large glass-forming region of the system. Fourteen investigated glass samples of barium borophosphate glasses were discussed for a comparison of the compositional trends in their properties in four compositional series such as A: (100 - ) Ba(PO3)(2)-xB(2)O(3), B: 40BaO-yB(2)O(3)-(60 - y) P2O5, C: (50 - z) BaO-zB(2)O(3)-50P(2)O(5), and D: (60 - w) BaO-wB(2)O(3)-40P(2)O(5). Changes in glass density and molar volume primarily depend on the BaO content in the glasses. The thermal properties were studied with a differential thermal analysis, hot-stage microscopy, and dilatometry. Glass transition temperature increases with a rising B2O3 content most rapidly in the glass series A and B. It reaches its maximum in these series for the glasses containing 20-30 mol%, where the glass network represents a 3D structure interlinked with P-O-B, P-O-P, and B-O-B bridges. The thermal expansion coefficient decreases, in contrast, with the increasing B2O3 content in these ternary glasses as well as their chemical durability. The crystallization of these glasses, in the samples with a low B2O3 content, results in the formation of barium metaphosphate BaP2O6. Certain crystallized samples also contain a small amount of BPO4, and diffraction lines of ternary compounds BaBPO5 and Ba3B(PO4)(3) were revealed in a number of samples. A new compound of the composition Ba5B2P8O28 was identified in the crystallized glass 50BaO-10B(2)O(3)-40P(2)O(5).Borofosfátová skla ternárního systému BaO-B2O3-P2O5 byla připravena a studována v existující šitoké oblasti sklotvornosti. Bylo připraveno 14 borofosfátových skel, jejichž vlastnosti byly diskutovány ve čtyřech kompozičních řadách A: (100 - ) Ba(PO3)(2)-xB2O(3), B: 40BaO-yB2O3-(60 - y) P2O5, C: (50 - z) BaO-zB2O3-50P2O5, a D: (60 - w) BaO-wB2O3-40P2O5. Změny v měrné hmotnosti a molárním objemu skel závisí zejména na obsahu BaO ve sklech. Termické chování skel bylo studováno diferenční termickou analýzou, žárovou mikroskopií a dilatometrií. Hodnota Tg roste s obsahenm B2O3 výrazně v řadách A a B a dosahuje maxima u skel s obsahem 20-30 mol%, kde je vytvářena trojrozměrná strukturní síť propojená vazbami P-O-B, P-O-P, a B-O-B. Naproti tomu s růstem obsahu B2O3 ve sklech klesá koeficient teplotní roztažnosti a chemická odolnost. Byly identidfikovány sloučeniny vznikající při krystalizaci skel a byla nalezena nova sloučenina o složení Ba5B2P8O28 při složení 50BaO-10B2O3-40P2O5