Effect of zirconia additives on the activity of the Cr/SiO2 catalyst in isobutane dehydrogenation

A new approach to the preparation of modified silica-based supports is suggested to obtain Crcontaining catalysts for paraffin hydrocarbon dehydrogenation. CrOx/ZrO2, CrOx/SiO2, and CrOx/nZrO2–SiO2 (n = 0.5, 1.0, and 2.0 ZrO2 monolayers) catalysts have been synthesized by incipient-wetness impregnation. The catalysts have been characterized by X-ray diffraction, diffuse reflectance spectroscopy, and temperature-programmed reduction with hydrogen. Their catalytic properties were investigated in the reaction of isobutane dehydrogenation. The state of the supported chromium depends considerably on the nature of the support. The formation of Cr2O3 particles, which show low activity in the dehydrogenation reaction, takes place in the CrOx/SiO2 catalyst, while chromium in the CrOx/ZrO2 catalyst is in a highly dispersed, X-ray-amorphous state. The addition of ZrO2 to CrOx/SiO2 increases the amount of chromium in the highly dispersed Cr(V) and Cr(VI) states, thus enhancing the isobutane dehydrogenation activity of the catalyst

Al2O3/SiO2 materials with bimodal pore size distribution as support for heterogeneous catalysts

The Al2O3/SiO2 materials prepared by impregnation of mesoporous silica with water solution of Al(NO3)3·9H2O were suggested to be used as supports for catalyst of high-temperature catalytic reactions. It was shown that the distribution of Al2O3 component inside wide pores of silica (10-50 nm) occurs with the formation of Al2O3 layer in case of low loading and porous layer or particles, if Al2O3 loading increases. Thus, materials with bimodal pore size distribution were obtained. The Cr-containing catalysts were prepared on the basis of these supports and tested in the process of isobutane dehydrogenation at 540 °C. It was observed that the activity of the obtained Cr/Al2O3/SiO2 materials was comparable with the one for Cr/Al2O3 catalyst. Thus, the suggested Al2O3/SiO2 materials with unique porous structure are promising to be used as supports for catalysts for high-temperature reactions.</jats:p

Regional Museum of the Ural: the Problem of Attracting the Target Audience

В статье рассмотрена проблема привлечения внимания к богатому наследию региональной культуры Урала. На примере музея-заповедника деревянного зодчества и уральской росписи в Нижней Синячихе описаны различные формы работы музея с посетителями. Автор обосновывает необходимость разработки новых экскурсионных программ, включающих игровые занятия и мастер-классы, интерактивную деятельность на специальных игровых площадках.The article deals with the problem of drawing attention to the rich heritage of regional culture of children and parents of the Museum-Reserve of Wooden Architecture and Ural painting in Nizhny Sinyachikha. The purpose is to analyze the possibilities of environmental and industrial design to attract children and adults to the museum; the effectiveness of building a design concept. The author substantiates the need to develop new excursion programs, including interactive activities on a special playground

A Case of Occupational Rhinitis Caused by Rice Powder in the Grain Industry

Rice is the major staple food in a large part of the world, especially in Asia. Hypersensitivity reactions to rice are rare. Moreover, cases of occupational allergies induced by inhalation of rice powder are uncommon. We report a 31-year-old male with work-related rhinitis and conjunctivitis symptoms caused by occupational exposure to rice powder in the grain industry. He showed positive responses to rice extracts on a skin prick test, and a high level of serum specific IgE to rice was detected by ELISA. Occupational rhinitis was confirmed by a nasal provocation test with rice extracts. An IgE ELISA inhibition test showed cross-creativity between rice and various grass pollen extracts. These findings suggest that the inhalation of rice powder can induce IgE-mediated occupational rhino-conjunctivitis, which may be derived from cross-reactivity to major grass pollens

Pathophysiological classification of chronic rhinosinusitis

BACKGROUND: Recent consensus statements demonstrate the breadth of the chronic rhinosinusitis (CRS) differential diagnosis. However, the classification and mechanisms of different CRS phenotypes remains problematic. METHOD: Statistical patterns of subjective and objective findings were assessed by retrospective chart review. RESULTS: CRS patients were readily divided into those with (50/99) and without (49/99) polyposis. Aspirin sensitivity was limited to 17/50 polyp subjects. They had peripheral blood eosinophilia and small airways obstruction. Allergy skin tests were positive in 71% of the remaining polyp subjects. IgE was<10 IU/ml in 8/38 polyp and 20/45 nonpolyp subjects (p = 0.015, Fisher's Exact test). CT scans of the CRS without polyp group showed sinus mucosal thickening (probable glandular hypertrophy) in 28/49, and nasal osteomeatal disease in 21/49. Immunoglobulin isotype deficiencies were more prevalent in nonpolyp than polyp subjects (p < 0.05). CONCLUSION: CRS subjects were retrospectively classified in to 4 categories using the algorithm of (1) polyp vs. nonpolyp disease, (2) aspirin sensitivity in polyposis, and (3) sinus mucosal thickening vs. nasal osteomeatal disease (CT scan extent of disease) for nonpolypoid subjects. We propose that the pathogenic mechanisms responsible for polyposis, aspirin sensitivity, humoral immunodeficiency, glandular hypertrophy, eosinophilia and atopy are primary mechanisms underlying these CRS phenotypes. The influence of microbial disease and other factors remain to be examined in this framework. We predict that future clinical studies and treatment decisions will be more logical when these interactive disease mechanisms are used to stratify CRS patients

EAACI position paper on occupational rhinitis

The present document is the result of a consensus reached by a panel of experts from European and non-European countries on Occupational Rhinitis (OR), a disease of emerging relevance which has received little attention in comparison to occupational asthma. The document covers the main items of OR including epidemiology, diagnosis, management, socio-economic impact, preventive strategies and medicolegal issues. An operational definition and classification of OR tailored on that of occupational asthma, as well as a diagnostic algorithm based on steps allowing for different levels of diagnostic evidence are proposed. The needs for future research are pointed out. Key messages are issued for each item

Effect of zirconia additives on the activity of the Cr/SiO2 catalyst in isobutane dehydrogenation

A new approach to the preparation of modified silica-based supports is suggested to obtain Crcontaining catalysts for paraffin hydrocarbon dehydrogenation. CrOx/ZrO2, CrOx/SiO2, and CrOx/nZrO2–SiO2 (n = 0.5, 1.0, and 2.0 ZrO2 monolayers) catalysts have been synthesized by incipient-wetness impregnation. The catalysts have been characterized by X-ray diffraction, diffuse reflectance spectroscopy, and temperature-programmed reduction with hydrogen. Their catalytic properties were investigated in the reaction of isobutane dehydrogenation. The state of the supported chromium depends considerably on the nature of the support. The formation of Cr2O3 particles, which show low activity in the dehydrogenation reaction, takes place in the CrOx/SiO2 catalyst, while chromium in the CrOx/ZrO2 catalyst is in a highly dispersed, X-ray-amorphous state. The addition of ZrO2 to CrOx/SiO2 increases the amount of chromium in the highly dispersed Cr(V) and Cr(VI) states, thus enhancing the isobutane dehydrogenation activity of the catalyst

The influence of support properties on state of supported CrOx and activity of chromium oxide catalysts in dehydrogenation of hydrocarbons.

SSCI-VIDE+ATARI+FCA:NSPInternational audienceNon