Structural and textural evolution of zirconia nanocrystals induced by thermal treatment

Nanometric tetragonal and monoclinic zirconia was synthesized from zirconyl chloride by the modified forced hydrolysis method. Phase transitions and morphological changes accompanying zirconia calcination in the temperaure range 600–1000 °C were studied by XRD, HR-TEM techniques and N2-porosimetry. Ageing of the amorphous hydrous zirconia at 100 °C for 48 h in the mother solution and its subsequent calcination at 600 °C for 6 h strongly favoured formation of single-phase tetragonal ZrO2 of the thermal stability enhanced by 250 °C. Influence of the calcination temperature on phase composition, grain size, grain boundaries and pore structure of the resultant ZrO2 material was analyzed

Racial differences in systemic sclerosis disease presentation: a European Scleroderma Trials and Research group study

Objectives. Racial factors play a significant role in SSc. We evaluated differences in SSc presentations between white patients (WP), Asian patients (AP) and black patients (BP) and analysed the effects of geographical locations.Methods. SSc characteristics of patients from the EUSTAR cohort were cross-sectionally compared across racial groups using survival and multiple logistic regression analyses.Results. The study included 9162 WP, 341 AP and 181 BP. AP developed the first non-RP feature faster than WP but slower than BP. AP were less frequently anti-centromere (ACA; odds ratio (OR) = 0.4, P < 0.001) and more frequently anti-topoisomerase-I autoantibodies (ATA) positive (OR = 1.2, P = 0.068), while BP were less likely to be ACA and ATA positive than were WP [OR(ACA) = 0.3, P < 0.001; OR(ATA) = 0.5, P = 0.020]. AP had less often (OR = 0.7, P = 0.06) and BP more often (OR = 2.7, P < 0.001) diffuse skin involvement than had WP.AP and BP were more likely to have pulmonary hypertension [OR(AP) = 2.6, P < 0.001; OR(BP) = 2.7, P = 0.03 vs WP] and a reduced forced vital capacity [OR(AP) = 2.5, P < 0.001; OR(BP) = 2.4, P < 0.004] than were WP. AP more often had an impaired diffusing capacity of the lung than had BP and WP [OR(AP vs BP) = 1.9, P = 0.038; OR(AP vs WP) = 2.4, P < 0.001]. After RP onset, AP and BP had a higher hazard to die than had WP [hazard ratio (HR) (AP) = 1.6, P = 0.011; HR(BP) = 2.1, P < 0.001].Conclusion. Compared with WP, and mostly independent of geographical location, AP have a faster and earlier disease onset with high prevalences of ATA, pulmonary hypertension and forced vital capacity impairment and higher mortality. BP had the fastest disease onset, a high prevalence of diffuse skin involvement and nominally the highest mortality

Synthesis of nanostructured tetragonal ZrO2 of enhanced thermal stability

Hydrous zirconia particles of nanometric dimensions were synthesized via forced hydrolysis of zirconyl chloride. Prolonged aging at 100°C in the mother liquor and subsequent calcination produced a single-phase tetragonal ZrO2 of enhanced thermal stability with the narrow size and pore distributions. The influence of the preparation conditions on the phase composition of the resultant zirconium dioxide was examined using structural (XRD, SEM/TEM) and spectroscopic (Raman) methods, supported by thermal analysis (DTA/TG, DSC) and N2-porosimetry. The nature of the parent salt, pH of the solution, the temperature of precipitation and aging, were found to be the key parameters of the successful synthesis. The sequence of mechanistic steps invoked to account for the formation of t-ZrO2 was rationalized using the concepts of zirconium aquatic chemistry

Influence of increasing doses of em-a preparation on properties of arable soils. Part II. Chemical properties

Współcześnie, coraz częściej tradycyjne rolnictwo do poprawy żyzności gleby wykorzystuje niekonwencjonalne preparaty takie jak roztwór Efektywnych Mikroorganizmów (EM). Preparatowi temu przypisuje się szereg pozytywnych efektów, wśród których wskazuje się wzrost żyzności gleb. Jednak stosowanie Efektywnych Mikroorganizmów budzi wiele kontrowersji. Dlatego podjęto wstępne badania dotyczące określenia ewentualnego wpływu preparatu EM na właściwości fizykochemiczne i chemiczne gleb uprawnych. Cel pracy zrealizowano w oparciu o doświadczenie z dwoma glebami (czarna ziemia i gleba płowa), które były inkubowane ze wzrastającymi dawkami preparatu EM-A. Wyniki badań nie potwierdziły pozytywnego wpływu Efektywnych Mikroorganizmów na ilości węgla organicznego, próchnicy czy wzrost pH gleb. Wzrastające dawki preparatu EM-A przyczyniły się do wzrostu ilości przyswajalnego potasu, magnezu, siarki i azotu mineralnego oraz obniżenia wartości S i PWK w glebie płowej. Z kolei w warunkach czarnej ziemi zawartości przyswajalnego potasu, magnezu, siarki, azotu mineralnego oraz kwasowości hydrolitycznej malały, a wartości S i PWK wzrastały wraz ze wzrostem dawki zastosowanego kondycjonera.Today, the traditional agriculture employs increasingly frequently unconventional preparations such as solutions of Effective Microorganisms (EM) to improve soil fertility. These types of preparations are believed to exert a number of positive effects including increased soil fertility. However, the application of Effective Microorganisms arouses numerous controversies. That is why initial experiments were undertaken with the aim to assess possible influence of an EM preparation on physical-and-chemical and chemical properties of arable soils. The aim of the study was realized on the basis of investigations employing two soils - Luvisols and Phaeozems - which were incubated with increasing doses of the experimental EMA preparation. The results of the performed experiments failed to confirm a positive impact of Effective Microorganisms on quantities of organic carbon, humus or increase of soil pH. Increasing doses of the EM-A preparation were found to increase quantities of available potassium, magnesium, sulphur and mineral nitrogen and to decrease S and PWK values in the examined grey-brown podzolic soil. On the other hand, in the case of the proper black earth, concentrations of available potassium, magnesium, sulphur and mineral nitrogen as well as hydrolytic acidity decreased, while S and PWK values increased together with the dose increase of the applied conditioner

Physico-chemical and Chemical Properties of Surface Layers of Selected Soils Located in the Vicinity of the Planned Tomisławice Open-cast Lignite Mine

Organic soils account for a small percentage of agriculturally utilised soils and are used primarily for meadows and pastures. A characteristic feature of these soils is connected with considerable contents of organic matter, which significantly modifies their physico-chemical and chemical properties. Water is another important factor determining productivity parameters of organic soils. Changes in water and air relations contribute to adverse changes in most soil properties, thus deteriorating agricultural value of soils. In view of the fact that in the vicinity of open-cast lignite mines drainage of organic soils is a more frequent phenomenon studies were undertaken to assess physico-chemical and chemical properties of soils located in such areas. Analyses were performed on mean bulk samples coming from surface layers of 7 soil profiles located in the vicinity of the Tomisławice open-cast mine. According to the WRB classification (2006) these soils were: Mollic Gleysol (profiles 1–3), Fibric Sapric Histosol (profile 4), Histic Gleysol (profile 5), Sapric Histosol (profile 6) and Limnic Histosol (profile 7). The study analysed the following physico-chemical properties: soil reaction, hydrolytic exchange (Hex), base saturation (BS), cation exchange capacity (CEC), index of soil complex saturation with base cation (V) as well as organic matter (OM) and total carbon (Ctot) content. The analysed chemical properties included total and available contents of macronutrients (N, P, K, Ca, Mg, S, Na) and microelements (Fe, Zn, Mn, Cu, Ni). Investigated soil properties were assessed on the basis of methods commonly applied in analyses of organic soils. Surface layers of analysed soils were characterised by broad ranges of contents for most investigated properties. Soils classified as Mollic Gleysol (profiles 1–3) had lower contents of M.O. and Ctot at higher values of Hw, BS and CEC in comparison to the other tested deposits. Generally soils from profiles 4–7 were characterised by greater contents of analysed macronutrients, both in their total and available forms. Irrespective of the soil deposit, surface horizons contained the greatest amounts of total nitrogen (4.27–22.25 g•kg-1) and the lowest contents of total sodium (65.73–105.55 mg•kg-1). Available amounts of macronutrients were highest for calcium (1.06–3.66 g•kg-1) and lowest for sodium (8.80–21.36 mg•kg-1). Quantitative variability shown in relation to microelements was considerable, mainly in case of iron, manganese and zinc. At the same time in the surface layers of the analysed soils the greatest amounts of total iron (2.10–32.63 g•kg-1) and available iron (0.47–20.00 g•kg-1) were recorded along with the lowest contents of total nickel (0.90–11.27 mg•kg-1) and available nickel (0.75–4.63 mg•kg-1). Total and available amounts of microelements were generally greater in Mollic Gleysol (profile 1–3). Irrespective of the presented quantitative differences, analysed soils were mostly characterised by limited resources of available phosphorus and potassium, and average levels of available manganese, zinc and copper

Impact of the addition of sewage sludge, communal compost and effective microorganisms on selected properties of the arablehumus humus level of mineral soil. Part II. Structure state

W pracy przedstawiono wyniki badań oceniających wpływ dodatków osadu i kompostu komunalnego oraz szczepionki efektywnych mikroorganizmów - w postaci roztworu EM-A - na parametry struktury poziomu orno-próchnicznego uprawnej gleby mineralnej. Założono doświadczenie inkubacyjne składające się z 10 kombinacji. Po dziewięciomiesięcznej inkubacji z poszczególnych kombinacji wycięto po 50 modeli agregatów glebowych (V = 1 cm3). Oznaczono takie parametry, jak: dynamiczną i statyczną wodoodporność, stan agregacji wtórnej po dynamicznym i statycznym działaniu wody, pojemność kapilarną oraz mechaniczną wytrzymałość agregatów na ściskanie. Aplikacja zastosowanych dodatków spowodowała poprawę większości ocenianych właściwości. Szczególnie wyraźny był wpływ dawki rekultywacyjnej osadu na wodoodporność statyczną i stan agregacji wtórnej. Zauważono także, iż aplikacja zastosowanych dodatków - większości przypadków - spowodowała wzrost zarówno minimalnej, jak również maksymalnej kapilarnej pojemności wodnej. Nie stwierdzono natomiast znaczącej poprawy odporności na ściskanie. Przedstawione rezultaty potwierdzają sugerowaną w literaturze opinię o bardzo zróżnicowanym wpływie na badane właściwości dodatków organicznych, w zależności od ich typów, dawek, czasu aplikacji oraz właściwości gleb. Zasadną więc wydaje się być kontynuacja podjętych badań z uwzględnieniem wymienionych czynników.The study presents research results the aim of which was to assess the impact of the addition of sludge and communal compost as well as of inoculums of effective microorganisms (in the form of EM-A solution) on structural parameters of the arable-humus level of mineral soil. An incubation experiment consisting of 10 combinations was established and after 9 months of incubation, 50 models of soil aggregates (V = 1 cm3) were cut out from each combination. The following parameters were determined: dynamic and static water resistance, the state of secondary aggregation after dynamic and static water action, capillary capacity and the mechanical resistance of aggregates to compression. The application of the applied additives resulted in improvement of the majority of the evaluated properties. The impact of the reclamation dose of the applied sewage sludge on static water resistance and the state of secondary aggregation was particularly noticeable. It was further observed that the employment of the applied additives (in the majority of cases) led to the increase of both minimal and maximal water capillary capacity. On the other hand, no significant improvement in compression resistance was observed. The presented results corroborate the opinion found in the literature on the subject concerning a very varied impact on the examined properties of organic additives depending on their types, applied doses, time of application as well as soil properties. Therefore, it seems justified to continue the initiated investigations taking into consideration the abovementioned factors