Corrosion properties of chromia based eco - friendly coatings on mild steel

Ceramic nanocrystalline coatings of chromium oxide (III) on steel S235JRH-1.0038 (EN 10025-1) were prepared using the liquid precursor plasma spraying (LPPS) method from ammonia dichromate (VI). Their structure and anti – corrosion properties were compared to the standard chromium oxide (III) coating prepared by thermal spraying. The newly prepared coatings had very high adhesion and minimal porosity. Anticorrosion properties were characterized by the means of the electrochemical impedance spectroscopy (EIS), measuring the charge transfer resistance Rct and capacitance of electrical double layer CPEdl in the 0,5 mol/l NaCl. Coatings of Cr2 O3 prepared by the LPPS method showed unambiguously improved anti - corrosion properties

Incorporation of tungsten metal fibers in a metal and ceramic matrix

Tungsten fibers have high tensile strength but a poor oxidation resistance at elevated temperatures. Using this first characteristic and to prevent oxidation of tungsten coated composite materials in which the primary requirement: reinforcement against destruction or deformation, was studied on tungsten fibers and tungsten wires which were coated by applying the metal and ceramic powders via plasma spraying device in plasma generator WSP®. Deposition took place in an atmosphere of Ar + 7 % H2, sufficient to reduce the oxidized trace amounts of tungsten

Selective Dimerization of Ethylene to 1-Butene with a Porous Catalyst

Current heterogeneous catalysts lack the fine steric and electronic tuning required for catalyzing the selective dimerization of ethylene to 1-butene, which remains one of the largest industrial processes still catalyzed by homogeneous catalysts. Here, we report that a metal–organic framework catalyzes ethylene dimerization with a combination of activity and selectivity for 1-butene that is premier among heterogeneous catalysts. The capacity for mild cation exchange in the material MFU-4l (MFU-4l = Zn[subscript 5]Cl[subscript 4](BTDD)[subscript 3], H[subscript 2]BTDD = bis(1H-1,2,3-triazolo[4,5-b],[4′,5′-i])dibenzo[1,4]dioxin) was leveraged to create a well-defined and site-isolated Ni(II) active site bearing close structural homology to molecular tris-pyrazolylborate complexes. In the presence of ethylene and methylaluminoxane, the material consumes ethylene at a rate of 41,500 mol per mole of Ni per hour with a selectivity for 1-butene of up to 96.2%, exceeding the selectivity reported for the current industrial dimerization process.Saudi AramcoAmerican Society for Engineering Education. National Defense Science and Engineering Graduate Fellowship3M CompanyResearch Corporation for Science Advancement. Cottrell Scholars ProgramAlfred P. Sloan Foundatio

Incorporation of tungsten metal fibers in a metal and ceramic matrix

Tungsten fibers have high tensile strength but a poor oxidation resistance at elevated temperatures. Using this first characteristic and to prevent oxidation of tungsten coated composite materials in which the primary requirement: reinforcement against destruction or deformation, was studied on tungsten fibers and tungsten wires which were coated by applying the metal and ceramic powders via plasma spraying device in plasma generator WSP®. Deposition took place in an atmosphere of Ar + 7 % H2, sufficient to reduce the oxidized trace amounts of tungsten

VIBROTHERMOGRAPHY FOR IMPACT DAMAGE DETECTION IN COMPOSITES STRUCTURES

The paper investigates modelling aspects related to application of vibrothermography for detection of barely visible impact damage in composite structures. Low-velocity impact tests were performed to introduce multiple delaminations into carbon/epoxy composite plate. Damage severity was revealed using well-established non-destructive evaluation techniques. Vibrothermography was used subsequently to show good agreement with classical damage detection techniques. Following these experimental investigations, numerical simulations were performed to assess feasibility and sensitivity of vibrothermography for impact damage detection. Numerical results were validated using experimental data showing very good qualitative and encouraging quantitative agreement. The study demonstrates that virtual impact damage detection using vibrothermography can be performed as part of structural design to assess sensitivity of the method in real engineering applications. Copyright © 2012 John Wiley & Sons, Ltd

Boronized steels with corundum-baddeleyite coatings

The paper describes preparation and properties of anti-corrosion and anti-abrasive coatings from corundum-baddeleyite ceramics deposited on surface of low-carbon boronized steel S235JRH-1.0038 (EN 10025-1) by plasma spraying method. Adhesive interlayers Fe2B reaches bond strength of up to 20 MPa in the pull-off tests, the ZrO2 - Al2O3 - SiO2 coatings have a value of fracture adhesion of 4 - 6 MPa. Hardness of these ceramic coatings on steel is as high as 1 800 HV100 and its polarization resistance is 1 600 Ω/cm2 to 4 000 Ω/cm2

ASSOCIATION OF FAMILIAL AND ENVIRONMENTAL FACTORS WITH ASTHMA AND ALLERGIC DISEASES IN UKRAINIAN CHILDREN POPULATION

Background. Asthma and other allergic diseases as influenced by environmental and familial factors might be targeted using preventive measures. These diseases are a matter of some urgency in Ukraine because of the clinical, social and economic importance of childhood.Objective. The aim of this study was to investigate the relationship between prevalence of asthma, spastic bronchitis, allergic rhinitis, atopic eczema, unspecified hypersensitization and some selected environmental and familial factors in a population sample of 6 to14-yrs old Western Ukraine schoolchildren.Methods. The data set of the study was collected using a questionnaire-based survey, containing the data of 4871 urban and rural children aged 6 to 14 years. Correlation of asthma and allergic disease with familial and environmental factors was examined by means of multivariate logistic regression.Results. Increased risk of asthma (1.7 %) was associated with the urban residence (OR=1.8; p=0.04) and high parental education (OR=1.8; p=0.02); spastic bronchitis (6.2%) – with parental allergy (OR=1.3; p=0.03); atopic eczema (6.2 %) – with younger age (OR=1.3; p=0.03), high parental education (OR=1.3; p=0.03), parental allergy (OR=1.4; p=0.02), tobacco smoke at home (OR=0.7; p=0.01) and household density (OR=0.6; p=0.001); diagnosis of unspecified allergic sensitization (11.8 %) was related to high parental education (OR=1.2; p=0.03),parental employment (OR=0.8; p=0.02) and pets at home (OR=1.2; p=0.06).Conclusions. This study identifies that lifestyle and building factors are associated with an altered prevalence of common childhood allergic disease. Prevention may need to address the minimization of potential risk-factorsKEY WORDS: asthma, environmental factors, children

Microdeletion of target sites for insulator protein CTCF in a chromosome 11p15 imprinting center in Beckwith-Wiedemann syndrome and Wilms' tumor

We have analyzed several cases of Beckwith-Wiedemann syndrome (BWS) with Wilms' tumor in a familial setting, which give insight into the complex controls of imprinting and gene expression in the chromosome 11p15 region. We describe a 2.2-kbp microdeletion in the H19/insulin-like growth factor 2 (IGF2)-imprinting center eliminating three target sites of the chromatin insulator protein CTCF that we believe here is necessary, but not sufficient, to cause BWS and Wilms' tumor. Maternal inheritance of the deletion is associated with IGF2 loss of imprinting and up-regulation of IGF2 mRNA. However, in at least one affected family member a second genetic lesion (a duplication of maternal 11p15) was identified and accompanied by a further increase in IGF2 rnRNA levels 35-fold higher than control values. Our results suggest that the combined effects of the H19//GF2-imprinting center microdeletion and 11p15 chromosome duplication were necessary for manifestation of BWS