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The electronic and optical characteristics of molybdenum disulphide (MoS2) film significantly vary with its thickness, and thus a rapid and accurate estimation of the number of MoS2 layers is critical in practical applications as well as in basic researches. Various existing methods are currently available for the thickness measurement, but each has drawbacks. Transmission electron microscopy allows actual counting of the MoS2 layers, but is very complicated and requires destructive processing of the sample to the point where it will no longer be useable after characterization. Atomic force microscopy, particularly when operated in the tapping mode, is likewise time-consuming and suffers from certain anomalies caused by an improperly chosen set point, that is, free amplitude in air for the cantilever. Raman spectroscopy is a quick characterization method for identifying one to a few layers, but the laser irradiation causes structural degradation of the MoS2. Optical microscopy works only when MoS2 is on a silicon substrate covered with SiO2 of 100~300 nm thickness. The last two optical methods are commonly limited in resolution to the micrometer range due to the diffraction limits of light. We report here a method of measuring the distribution of the number of MoS2 layers using a low voltage field emission electron microscope with acceleration voltages no greater than 1 kV. We found a linear relationship between the FESEM contrast and the number of MoS2 layers. This method can be used to characterize MoS2 samples at nanometer-level spatial resolution, which is below the limits of other methods.

In Fe-3%Si-0.3%C steel sheet, a relatively strong //ND texture can evolve in the surface layer through the α→γ→α phase transformation in relatively low vacuum (4 Pa) for an annealing time of 10 min and at a cooling rate of 20 K/s. Oxidation of the steel sheet surface prevents the evolution of the //ND texture. However, vacuum-annealing under a vacuum pressure of 1.3×10-3 Pa causes decarburization of the steel sheet, which suppresses oxidation of the steel sheet surface, and subsequent annealing in wet hydrogen of 363 K in dew points causes a columnar grain structure with the //ND texture. After the two-step-annealing (the vacuum annealing under a vacuum pressure of 1.3×10-3 Pa and subsequent decarburizing annealing in wet hydrogen of 363 K in dew points), the decarburized steel sheet exhibits good soft magnetic properties in NO with 3%Si, W15/50 (core loss at 1.5T and 50 Hz) = 2.47 W/kg and B50 (magnetic flux density at 5000 A/m) = 1.71 T.

In this study, the synthesis of porous titania-silica (TiO2-SiO2) composite aerogel at ambient pressure by using non-hazardous chemicals as a source of silica was investigated. TiO2-SiO2 composite aerogels were characterised and their photocatalytic performances were investigated for the removal efficiency of acetaldehyde and NO(x) under UV light. Results showed that porous composite aerogel with aggregated morphology, high surface area and an increased mesoporosity were formed. TiO2-SiO2(1.8) composite, with high Ti/Si ratio, showed the best results in terms of photocatalytic removal of acetaldehyde and nitrogen oxide.

Demand for air conditioners is steadily increasing due to global warming and improved living standards. The noise, as well as the performance of air conditioners, are recognized as one of the crucial factors that determine the air conditioners&rsquo, values. The performance and noise of the air conditioner are mostly determined by those of its outdoor unit, which in turn depend on those of the cooling fan unit. Therefore, a cooling fan unit of high-performance and low noise is essential for air-conditioner manufacturers and developers. In this paper, the flow performance and flow noise of the entire outdoor unit with an axial cooling fan in a split-type air-conditioner were investigated. First, a virtual fan tester constructed by using about 18 million grids is developed for highly resolved flow simulation. The unsteady Reynolds-Averaged Navier&ndash, Stokes equations are numerically solved by using finite-volume computational fluid dynamics techniques. To verify the validity of the numerical analysis, the predicted P&ndash, Q curve of the cooling fan in a full outdoor unit is compared with the measured one. There was an excellent agreement between the two curves. The further detailed analysis identifies the coherent vortex structures between the fan blade tip and fan orifice, which adversely affect the flow performance and causes flow noise. Based on this analysis, the optimization of fan orifice was carried out using the response surface method with three geometric parameters: inlet radius, neck length, and outlet angel of the orifice. The optimum layout for the high flow rate is proposed under the understanding that the increased flow rate can be converted to noise reduction. The additional computation using the proposed optimum orifice shows that the flow rate is increased by 4.6% at the operating point. Finally, the engineering sample was manufactured by using the optimum design, and the measured data confirmed that the flow rate were increased by 2.1%, the noise reduction was made by 2.8 dBA, and the power consumption is reduced by 4.0% at the operating rotational speed.

Diffusion annealing has been performed to investigate the influence of diffusion parameters on the diffusion behavior of 3.2% Si-grain-oriented steel coated with Al using plasma vapor deposition (PVD). When Fe-Si steel sheets coated with Al-PVD were annealed at 1373 K, a single-phase solution of Al with uniform concentration was formed in α-Fe without intermetallic phases. It was confirmed that Kirkendall voids nucleate during interdiffusion between solid Al and Fe in the annealing process and volume fraction of Kirkendall voids decreased as the heating rate increased. Rapid heating (55 K/s) can prevent the formation of Kirkendall voids, possibly by reducing the time available for interdiffusion between solid Al and Fe. The results show that the alloying of 2 wt% Al was achieved without the formation of interme-tallic phases and Kirkendall voids, and that this alloy can increase resistivity and reduce eddy current loss. This was found to results in reduced core loss by ~10%.

Norms for the emissions of NO x are becoming stricter and stricter, leading to an increase in the research interest for the development of novel gas cleaning technologies. In this study, the use of titania (TiO 2 ) produced from Ti-salt flocculated sludge, mixed with mortar, has been investigated as a cost-effective novel solution for the removal of these pollutant gases. This work not only presents an advanced solution for sludge reduction but also proposes a novel production method of TiO 2 powders from waste water and investigates the potential use of this material blinded with mortar for a novel application which is air purification. Detailed characterization of the produced TiO 2 powders was performed and results showed that the primary particles present a uniform size and spherical shape with a diameter of less than 50 nm. The main constitutive elements were Ti, O, C and P, where the Ti content was found to increase slightly with increasing temperature. The anatase phase was observed at 600 °C and 800 °C and converted to rutile structure at 1000 °C. Two contents (i.e. 3.0 and 5.0 wt%) of TiO 2 were tested for mixing with mortar and photocatalytic properties of the mortar containing TiO 2 were evaluated for the removal of NO x and were found to be similar to commercial TiO 2 (P-25) in terms of photocatalytic activity. Further investigations under direct sunlight were conducted after 28 days of water curing to evaluate the removal of NO x . The NO rejection was about 50% after 5 h.

The friction behavior of human skin is determined by the complex interplay of the material and sur-face properties of the skin, as well as the contacting material, and strongly depends on the contact parameters(e.g., pressure and sliding velocity) and the presence of substances such as water, sweat, or skin surface lipidsat the interface. Including a study on the effect of a surface's physical roughness for skin sliding over the surface,various studies have been conducted to understand human tactile sensibility. However, to investigate products inrelation to human tactile sensibility, more objective research is needed. This study performed sliding experimentsbetween the skin and the surfaces of phone cases to understand how the texture, friction, and stick-slip char-acteristics are related. Eight phone case surfaces with different topologies and chemical (or mechanical) com-patibilities with skin were prepared and tested multiple times. Keywords finger(손가락), friction(마찰), skin tribology(피부 트라이볼로지), biotribology(바이오 트라이볼로지), haptics(햅틱스), tactile(촉감), phone case(휴대폰 케이스), touch(터치)

부영양화 방지를 위하여 규제되는 총인(Total-phosphorous, T-P) 농도가 0.2~2 mg/L 이하로 변경됨에 따라, 응집 처 리 과정에서 인의 제거를 시도하게 되었다. 따라서 본 연구는 실제 하수종말처리장의 생물학적 처리수를 시료로 하여 티탄염 농도, pH 등의 인자가 인 제거에 미치는 특성에 대하여 검토하였다. 또한 실제 현장에서 가장 많이 사용되는 침강식 침전조와 가압부상식 침전조에 티탄염을 적용하여 인 제거 효율 및 슬러지 활용 가능성을 조사하였다. 응집제 로 티탄염을 사용하는 경우 인 제거효율이 기존에 사용하는 황산 알루미늄(Al2(SO4)3, Alum)과 유사하였다. 하향 침강 방식의 침전조와 가압부상방식의 침전조 모두 기준치 이하로 모두 현장 적용이 가능하였다. 생성된 산화티탄의 성분 은 원수에 포함된 무기물과 투입된 티탄염 성분으로 구성되었다. 티탄염 응집 후 생성된 슬러지를 소성하여 산화티탄 을 제조하였다. 시판되고 있는 P-25 제품과 유사한 광촉매 활성을 가지고 있어 슬러지에서 생성된 산화티탄도 기존에 사용하는 제품시장에 대체 사용이 가능할 것으로 판단된다.

Graphical abstractDisplay Omitted Highlights? FE modelling of Cu pillar bumps of different types. ? Stress distribution in solder interface and TSV interface. ? Reliability of conical frustum type is excellent than other types. The through silicon via (TSV) is a technology for vertical interconnection between multiple chips that employ a hole bored through a Si wafer and stack chips, which is good for securing a number of I/O per unit area reducing the electric resistance. On the other hand, vertical multi-layers are structurally more unstable than a single-layer but are vulnerable to a thermo-mechanical effect. Therefore, in this study, finite element analysis (FEA) of a three-dimensional (3D) multi-layer semiconductor with TSV was carried out to examine the changes in thermo-mechanical stress at the bonding interface with different models of Cu pillar bumps and Sn-3.5Ag solder bumps. A numerical simulation was carried out with different models, such as a plate type, pin type, skirt type, zigzag type and conical frustum type. The height and diameter of each solder bump were 10µm and 30µm, respectively. The distribution of Von Mises stress occurred more at the solder joint interface and TSV joint interface. At the solder joint interface, the stress in the skirt type (100.6MPa) was approximately double that in the conical frustum type (53.1MPa). At the TSV joint interface, the stress in the plate type (17.2MPa) was higher than that in the other types. The stress values were similar in the other types except for plate type Cu pillar bump. Stress in the solder and TSV joint interface was caused partly by the difference in properties between the two materials. In particular, mismatch in the coefficient of thermal expansion (CTE) had the greatest effect on the stress distribution.

In this study, the synthesis of porous titania-silica (TiO2-SiO2) composite aerogel at ambient pressure by using non-hazardous chemicals as a source of silica was investigated. TiO2-SiO2 composite aerogels were characterised and their photocatalytic performances were investigated for the removal efficiency of acetaldehyde and NO(x) under UV light. Results showed that porous composite aerogel with aggregated morphology, high surface area and an increased mesoporosity were formed. TiO2-SiO2(1.8) composite, with high Ti/Si ratio, showed the best results in terms of photocatalytic removal of acetaldehyde and nitrogen oxide.

The incorporation of zirconia onto the silica supports of platinum catalysts improved the selective reduction of NO by hydrogen in comparison to platinum catalysts supported on silica and alumina. The catalysts were characterized by X-ray diffraction, transmission electron microscopy, the temperature-programmed desorption of ammonia, X-ray photoelectron spectroscopy, and the adsorption of carbon monoxide. Their performances were examined in a flow microreactor and by in situ IR spectroscopy. The incorporation of zirconia onto silica created many strong acid sites and stabilized the dispersed platinum. It aided the adsorption of NO and enhanced the formation of ammonia on the platinum catalysts, even in the presence of excess oxygen. The formation of ammonia from NO and the subsequent removal of NO through reaction with ammonia considerably improved the conversion of NO and the yield of N2. The presence of zirconia also improved the stability of the supported platinum against hydrothermal treatment.

The texture can be evolved through the γ to α transformation by cooling in Fe-Si alloy systems. Oxygen in the annealing atmosphere hampers the evolution of the texture. The texture evolution is associated with the fact that the {100} faces are elastically compliant so that the texture can develop in a manner consistent with minimization of strain energy. By alloying Mn to Fe-Si alloys, the texture evolves in relatively high oxygen containing annealing atmosphere. The role of Mn in the texture evolution appears to be preventing formation of surface oxides, which modify the elastic modulus of metal surface, thereby suppress the development of the correct texture.

Four kinds of MFI-meso zeolites with both micro- and mesopores were prepared, characterized, and their catalytic activities were evaluated in the liquid-phase degradation of high-density, low-density, and linear low-density polyethylene (HDPE, LDPE, and LLDPE) in order to discuss their catalytic performance in relation to their porous characteristics and acidity. MFI-syn that was synthesized from partially dissolved MFI zeolite and MFI-sda that was prepared by using a special structure directing agent exhibited highly ordered mesopores with strong acidity and achieved high conversions, about 95%, even with small catalyst loadings (HDPE/catalyst = 20 g/0.05 g) at 380 °C. However, MFI-oxy prepared from an oxyacid-added mixture exhibited a poor catalytic activity because of its low acidity and small pore volume. MFI-alk prepared by an alkali treatment exhibited irregular mesopores and medium conversions. MFI-meso zeolites were especially suitable for the degradation of HDPE and LLDPE, which required a high external surface for the initial degradation of polyethylene and a rapid mass transfer, resulting in a higher catalytic activity. The enhancement of catalytic activity in the degradation of LDPE by the introduction of mesopores was relatively small because of its rapid initial degradation.

A two-step rolling–annealing process has been developed to increase the 〈1 1 1〉//ND (γ fiber) component in the recrystallization texture of a copper-bearing bake hardening steel. The two step process comprises the first rolling by a low reduction in thickness and subsequent annealing at 780 °C, followed by the second rolling by a high reduction and subsequent annealing at 780 °C. The first rolling process aims at seeding the γ fiber oriented grains, so that they can grow at the expense of differently oriented grains developed in the second rolling process. In this way the density of γ fiber component in the recrystallization texture of the bake hardening steel much increases compared with that in the conventional one-step rolling–annealing process.

Polyacetal is used as a part of the lower arm ball joint in the automobile chassis system. It is used as the bushing material, which is in contact with the steel ball on stud under the grease-lubricated condition. In an automobile chassis system, environmental factors reduce the durability of the automotive components. While driving, the grease is contaminated with dust particles and water. Introduction of the dust particles and water into the ball joint increases the wear of the bushing. The damage or the failure of the ball joint can generate noise and lead to uncomfortable driving conditions. Also, it will reduce the durability of other components in the chassis system. Since the ball joint is directly exposed to external environments, it is necessary to investigate the effect of contaminants on the wear of the bushing. In this study, the wear behaviour of the polyacetal bushing for inflow of dust particles and water were investigated. The ball-on-disk type wear test was used for the sliding tests. The disk specimen was made with polyacetal material and the ball specimen was made with steel. The wear volume increased with the amount of the dust particles up to 1.5 g/10 ml and then decreased. The surface was covered with the dust particles, so the dust layer had to be removed to further wear out the surface. The wear volume increased with the amount of the water. When grease was contaminated with water, a water layer, instead of the grease layer, formed on the surface during sliding.

열에 대한 응력이 최소가 되는 최적조합을 판단하여 Taguchi 실험계획법의 망대특성을 이용한 열응력 값에 대한 평균의 평균값이 높을수록 신뢰성이 좋은 영향을 주는 요인으로 결정하여 실험을 진행하였다. Fig. 7는 솔더 계면에서의 신뢰성의 반응들을, Fig. 8은 TSV 계면에서의 신뢰성의 반응들을 수치로 나타낸 것 이다. Fig. 7과 Fig. 8에서 보이는 바와 같이 두 계면에서의 열응력에 대한 신뢰성 반응의 경향은 비슷하게 나타남을 확인 할 수 있다. TSV의 직경이 증가할수록 솔더의 두께가 감소할수록 TSV 피치가 감소할수록 언더필의 두께가 증가 할수록 신뢰성에 좋은 영향을 미친다는 것을 확인할 수 있었다. 솔더의 두께와 TSV 피치의 변수는 사이즈가 바뀜에 그래프가 일정한 형상을 나타내지만 TSV 직경과 언더필의 두께의 변수는 그래프의 형상이 일정하지 않음을 확인할 수 있다. 이는 TSV 직경과 언더필의 두께의 변수를 어떻게 결정하느냐가 접합부의 신뢰성에 많은 영향을 미친다는 것을 의미한다

Platinum catalysts supported on silicas with various physicochemical properties were prepared in order to investigate the effect of silica characteristics on their platinum dispersion and catalytic activity in the oxidation of carbon monoxide. Although titania-incorporation into silica and further treatment of the impregnated platinum precursor with hydrogen peroxide were effective for improving the dispersion and stability of platinum catalysts supported on silicas, regardless of the characteristic of the silicas, the platinum catalysts supported on fumed silica with a medium level of surface hydroxyl group concentration exhibited the highest catalytic activity among those supported on mesoporous silica, silica gel, and precipitated silica. The required properties of the highly active platinum catalyst seemed to be a high dispersion of platinum, the formation of a stable titania layer, and the generation of strong acid sites. By contrast, the precipitated silica with a small surface area and high concentration of surface hydroxyl groups was not appropriate for a catalytic support for platinum catalysts.

Aim: Thromboxane A synthase (TBXAS1) converts prostaglandin H to thromboxane A, a potent constrictor of smooth respiratory muscle. Thus, functional alterations of the TBXAS1 gene may contribute to aspirin-intolerant asthma (AIA). Materials & methods: We investigated the relationship between SNPs in the TBXAS1 gene and AIA. Asthmatics (n = 470) were categorized into AIA (20% or greater decreases in forced expiratory volume in 1 s [FEV1], or 15% to 19% decreases in FEV1 with naso-ocular or cutaneous reactions) and aspirin-tolerant asthma (ATA). A total of 101 SNPs were genotyped. mRNA expression of the TBXAS1 gene by peripheral blood mononuclear cells and plasma thromboxane B2 (TXB2) concentrations were measured by reverse transcriptase (RT)-PCR and ELISA. Results: Logistic regression analysis showed that the rare allele frequency of rs6962291 in intron 9 was significantly lower in the AIA group (n = 115) than in the ATA group (n = 270) (pcorr = 0.04). The linear regression analysis revealed a strong association of rs6962291 with the aspirin challenge-induced FEV1 fall (p = 0.003). RT-PCR revealed an exon-12-deleted splice variant. We measured TBXAS1 mRNA levels in peripheral blood mononuclear cells. The mRNA levels of the full-length wild-type and splice variant were significantly higher in the TT homozygotes than in the AA homozygotes of rs6962291 (1.00 ± 0.18 vs 0.57 ± 0.03 and 1.00 ± 0.18 vs 0.21 ± 0.05, p = 0.047 and 0.001, respectively). The plasma TXB2 level was significantly lower in rs6962291 AA carriers than in rs6962291 TT (p = 0.016) carriers. Conclusion: The rare allele of rs6962291 may play a protective role against aspirin hypersensitivity via a lower catalytic activity of the TBXAS1 gene, attributed to the increase of a nonfunctioning isoform of TBXAS1. Original submitted 26 August 2010; Revision submitted 29 October 2010.

Pt–MnO x catalysts without any alkali or transition metals were prepared and their performance in the selective catalytic reduction (SCR) of NO by H 2 was examined. Their physicochemical properties were investigated using X-ray diffraction (XRD), extended X-ray adsorption fine structure (EXAFS), and X-ray photoelectron spectroscopy (XPS). The adsorption and removal of NO during H 2 -SCR were monitored by an in situ FT-IR spectrophotometer. The co-presence of MnO and MnO 2 on Pt–MnO x was confirmed by EXAFS and XPS. NO was adsorbed on them as nitrate and nitrite, which were subsequently transformed to NH x species by the introduction of H 2 . The NH x species adsorbed on the acid sites of manganese oxide were active in the reduction of NO, although a direct reduction by H 2 was also possible. The conversion of NO over the Pt(2.0)–MnO x catalyst was maximized to 64% at around 100 °C and fell with further increases in temperature. The N 2 yield over the Pt(2.0)–MnO x catalyst was 30% at the same condition, indicating that about a half of NO was converted to N 2 . On the contrary, the Pt(2.0)/SiO 2 catalyst exhibited very low N 2 yield, 10%, because N 2 O was highly produced. The reaction between the hydrogen atoms activated on the platinum and the activated NO on the manganese oxide was considered essential for H 2 -SCR, and NH 3 that formed as an intermediate effectively participated to the selective reduction.

Objective Aspirin affects interleukin-4 (IL-4) synthesis; however, the genetic role of IL-4 has not been evaluated in asthmatics with aspirin hypersensitivity. The objective of the study was to examine the influence of single nucleotide polymorphisms (SNPs) in IL-4 gene on aspirin hypersensitivity in asthmatics at the genetic and molecular levels. Methods Aspirin-intolerant (AIA, n= 103 ) and aspirin-tolerant asthmatics (n=2 70 ) were genotyped and functional promoter assays were performed. Results Of 15 S N Ps tested, seven (- 589T > C (rs2243250) in promoter, -33T>C (rs2070874) in the 5'-untranslated region, +4047A>G (rs2243266), + 4144C> G (rs2243267), + 4221C> A (rs2243268), +4367G>A (rs2243270), and +5090A>G (rs2243274) in introns) were significantly associated with AIA risk. The frequency of the rare allele (C) of -589T>C was higher in the AIA group than in the aspirin-tolerant asthmatic group (P corr =0.016), and a gene dose-dependent decline in forced expiratory volume in 1 s was noted after an aspirin challenge (P=0.0009). Aspirin unregulated IL-4 mRNA production in Jurkat T and K562 leukemia cells. A reporter plasmid assay revealed that aspirin augmented IL-4 promoter transactivation with the -589T>C C and -33T>C C alleles, compared with that bearing the -589T> C T and -33T > C T alleles. Further, electrophoretic mobility shift assay showed the formation of nuclear complexes with -33T>C and - 589T > C allele-containing probes; this was augmented by aspirin. The complexes formed with the -33T>C and -589T>C probes were shifted by treatment with anti-CCAAT-enhancer-binding proteins β and anti-nuclear factor of activated T-cells antibodies, respectively, indicating the inclusion of these transcription factors. Conclusion Aspirin may regulate IL4 expression in an allele-specific manner by altering the availability of transcription factors to the key regulatory elements in the IL4 promoter, leading to aspirin hypersensitivity.

In an automobile chassis system, several environmental factors reduce the durability of automotive components. In particular, dust particles entering through rubber seals increase the friction and wear of sliding surfaces. Increased wear causes noise, fracture, and reduced service life of components. In this study, dust particles were collected on the chassis while driving. The particle sizes and ingredients of the dust were analyzed using microscopy, scanning electron microscopy, and energy-dispersive X-ray. It was found that SiO and AlO were the main ingredients of the dust particles. Based on our analysis of the data, wear tests were performed with the rubber seal specimens using a ball-on-disk type sliding wear tester. When SiO and AlO particles came into contact with the rubber seal specimen, two-body and three-body abrasive wear took place. In tests of SiO particles only, the wear volumes of rubber seal specimens were increased by increasing the particle's injection amount and the size of the dust. ...

Nuclear factor-κB (NF-κB) orchestrates the expression of genes responsible for airway inflammation and remodeling in asthma. The activity of NF-κB is tightly regulated by IKBA, which may be modulated by genetic polymorphisms of the IKBA gene. We investigated the association between asthma susceptibility and IKBA gene polymorphisms in a Korean population. Genotyping was performed in BA (bronchial asthma) and NC (normal control). We measured reverse transcription-polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay, and luciferase reporter assays, respectively. A -673A>T (rs2233407) was associated with asthma development in subjects with atopic asthma (odds ratio = 0.56, p = 0.004). The IKBA mRNA level was higher in B-cell lines with the rs2233407 TT genotype compared with those with the AA genotype (p = 0.024). The luciferase activity of the rs2233407 T genotype was higher than that of the A (p = 0.002). The cytoplasmic levels of total IKBA and IKBA [p-S32] were higher in B cell lines of the rs2233407 TT genotype than those of the AA (p = 0.016 and p = 0.036, respectively), whereas nuclear NF-κB activity in cells with the IKBA rs2233407 AA genotype was higher than in cells with the AA (p = 0.038). The IKBA rs2233407 A>T polymorphism may predispose individuals to the development of atopic asthma via regulation of IKBA gene expression at the transcriptional level.

The adsorption of NO and NO2 and their subsequent reduction by hydrazine monohydrate (HDM) over Fe-BEA zeolite were investigated using an FT-IR spectrophotometer equipped with an in-situ cell. Although NO and NO2 molecules were adsorbed on Fe species in an unaltered state, some of them reacted with oxygen atoms, resulting in the adsorption of NO2 and NO 3 − , respectively. The reducing species that had originated from HDM on Fe-BEA selectively reduced these molecules to N2, while a small amount of N2O was formed in the reduction of NO by HDM. NO and NO2 were rapidly reduced by HDM through their adsorbed state even at 150 °C, and Fe species were required for their adsorption and for the formation of reducing species from HDM.

Highly active and stable platinum catalysts for propane combustion were prepared by impregnating platinum on zirconia-incorporated silica by combining the high surface area of silica with the exceptional thermal stability of zirconia. The thermal stability of the platinum catalysts was examined after thermal aging at 800 °C for 50 h. The physico-chemical states of the platinum and zirconia were investigated by using various analytical instruments, CO and H2 chemisorption, and temperature-programmed-desorption of ammonia. The platinum catalysts prepared on the zirconia-incorporated silica and treated with hydrogen peroxide showed high catalytic activity and stability in propane combustion. The high dispersion of platinum and the acid site generation achieved due to the incorporation of zirconia on the silica were responsible for the high activity and stability of the catalysts. Highly active and stable platinum catalysts for propane combustion were prepared by impregnating platinum on zirconia-incorporated silica by combining the high surface area of silica with the exceptional thermal stability of zirconia. The platinum catalysts supported on zirconia-incorporated silica maintained their activity after thermal aging at 800 °C for 50 h.]

Aims: Cysteinyl leukotrienes are inactivated by acetyl coenzyme A-dependent N-acetyltransferase (NAT). Thus, functional alterations of the NAT gene may contribute to the risk of aspirin-intolerant asthma. Materials & methods: Asthmatics (n = 438) were categorized into aspirin-intolerant asthma (15% or greater decrease in the forced expiratory volume in 1 s or cutaneous reactions, n = 170) or aspirin-tolerant asthma (n = 268) groups. In total, 14 polymorphisms of the NAT2 gene were genotyped by a single-base extension method. Results: The distributions of all loci of the 14 SNPs were in Hardy–Weinberg equilibrium (p > 0.05). Among the 14 SNPs, six common SNPs (minor allele frequency >5%) in a Korean population were used for haplotype construction and further statistical analysis. The logistic regression analysis demonstrated that NAT2 -9246G>C and haplotype 2 (TCACGG) were significantly associated with the risk of aspirin-intolerant asthma. The rare allele frequencies of the SNP and Ht2 were significantly higher in the aspirin-intolerant asthma group than in the aspirin-tolerant asthma group (pcorr = 0.03 and pcorr = 0.02 in codominant model). Conclusion: In a large genetic epidemiology study of aspirin-intolerant asthma in a Korean population, genetic polymorphisms of NAT2 were found to be related to a risk of aspirin hypersensitivity among asthmatics.

Transesterification of triacetin, tributyrin and soybean oil with methanol was examined over rehydrated hydrotalcites (HT-reh), which were previously calcined at 550 °C and exposed to an ambient atmosphere, in order to investigate the effect of the water content on their catalytic activity. Rehydration of a calcined hydrotalcite at 25 °C produced uniform mesopores of around 4 nm diameter, while the removal of water from the HT-reh by pretreatment at 500 °C, formed large heterogeneous mesopores. Methanol was adsorbed and desorbed rapidly in the mesopores of the HT-reh filled with water. The pretreatment of the HT-reh at 500 °C removed both water and carbon dioxide, producing strong basic sites. The high activity of fully rehydrated hydrotalcite in the transesterification of three triglycerides was explained by the generation of Bronsted basic sites and the rapid migration of methanol in the mesopores, while the improved activity of the rehydrated hydrotalcite pretreated at 500 °C by the generation of strong basic sites and empty mesopores due to the removal of water and carbon dioxide.

Nuclear cladding tubes are subjected to low-amplitude flow-induced vibrations (FIVs). Fretting wear occurs when two contacting surfaces are exposed to very low oscillation. Because nuclear cladding tubes are damaged by this fretting wear, it is necessary to try to evaluate the lifetime and improve the wear resistance of the tube. For this purpose, it is very important to clearly understand the damage mechanism of the tubes. Therefore, the present study undertook fretting-wear tests to investigate how the fluid that flows between the tube and the supporting grid affects the fretting wear. The governing damage mechanism consisted of abrasive wear and surface detachment behavior. In the case of the fluid flow environment, most of the wear debris was ejected from the contacting surfaces and this mode had a large effect on the maximum wear depth of the tube or wear amount. Additionally, the tests were performed under the water flow state as well as the water/air flow state. The result is that if the fluid flow...

Four kinds of large port zeolites BEA, FAU, LTL and MOR, were used as catalysts in the dehydration of a large molecule, epiandrosterone, to elucidate the effect of their pore structure on its conversion and the selectivity for 5α-androst-2-en-17-one (Δ2-olefin). Silane masking of the zeolite acid sites, measurement of their epiandrosterone uptake, and theoretical calculations to find the energy-minimized conformation in zeolite pores revealed the roles of pore structure and acid sites in the dehydration. LTL and MOR zeolites showed poor conversion and low selectivity for Δ2-olefin because of the close packing in their linear pores. BEA and FAU zeolites with three-dimensionally connected pores exhibited high conversion. Since the supercages of FAU zeolite provided enough space to allow tilted conformation of epiandrosterone with high preference for the formation of Δ2-olefin, FAU zeolites with a sufficient number of acid sites demonstrated both high conversion and selectivity in the dehydration of epiandrosterone.

Summary Background The peroxisome proliferator-activated receptors (PPAR) are the nuclear hormone receptor superfamily of ligand-activated transcriptional factors. PPAR-gamma (PPARG) activation downregulates production of Th2 type cytokines and eosinophil function. Additionally, treatment with a synthetic PPARG ligand can reduce lung inflammation and IFN-gamma, IL-4, and IL-2 production in experimental allergic asthma. In patients with asthma, PPARG gene expression is known to be associated with the airway inflammatory and remodeling responses. Thus, genetic variants of PPARG may be associated with the development of asthma. Methods We genotyped two single nucleotide polymorphisms on the PPARG gene, + 34C > G (Pro12Ala) and + 82466C > T (His449His), in Korean subjects (839 subjects with asthma and 449 normal controls). Results Association analysis using logistic regression analysis showed that + 82466C > T and haplotypes 1(CC) and 2(CT) were associated with the development of asthma ( p =0.01–0.04). The frequency of PPARG - ht2 was significantly lower in the patients with asthma compared to the normal controls in codominant and dominant models ( p =0.01, p corr =0.03 and p =0.02, p corr =0.03, respectively). Conversely, the frequency of PPARG - ht1 was significantly higher in the patients with asthma compared to the normal controls in the codominant model [ p =0.04, OR: 1.27 (1.01–1.6)]. In addition, the rare allele frequency of + 82466C > T was significantly lower in patients with asthma in comparison to normal controls in the codominant model (OR: 0.78, p =0.04). Thus, polymorphism of the PPARG gene may be linked to an increased risk of asthma development.

The deactivation of a barium oxide-based NOx storage and reduction (NSR) catalyst with hydrothermal treatment was studied by treating it with 10 vol% water vapor diluted in nitrogen at 850°C. XRD, XPS, SEM, IR of CO adsorption, and the N2 adsorption was used to investigate the physical and chemical changes of the NSR catalyst caused by the hydrothermal treatment. The 12 h hydrothermal treatment decreased its NO2 storage capacity by 20%. However, the hydrothermal treatment significantly decreased its ability to reduce the stored NO2. The formation of an inactive phase consisting of platinum and aluminum is believed to be the cause of the severe deactivation of the NSR catalyst.

Barium oxide-based NO x storage and reduction (NSR) catalysts with different amounts of potassium oxide were prepared to investigate the role of potassium oxide in the aspects of amount and strength of NO 2 storage. The dispersion of barium and potassium oxides on alumina, the amount and state of NO 2 stored on them, and the desorption profiles of NO 2 from them were examined by XRD, N 2 adsorption, electrical conductivity measurement, XPS, FT-IR and TPD techniques. Barium and potassium oxides were mainly loaded in the mesopores of the alumina and the NO 2 was stored by being converted to nitrates. The alumina itself had a small capacity for NO 2 storage, but the impregnation with potassium oxide increased the capacity. The co-loading of potassium oxide and barium oxide enhances the strength of the interaction between the storage material and NO 2 , shifting the desorption peak of NO 2 to a elevated temperature.

SummaryInterleukin (IL)-5 and eotaxin families regulate the development of eosinophilic inflammation of asthma in a co-operative manner. The exposure to airborne lipopolysaccharide (LPS) induces varying degrees of airflow obstruction and neutrophilic airway inflammation. Production of IL-5 and eotaxin subfamily chemokines was analysed in response to Dermatophagoides pteronyssinus allergen (D.p.) according to the presence of specific IgE to D.p., and investigated the mechanism underlying their LPS-mediated regulation of these cytokines in response to the specific allergen. Peripheral blood cells (PBCs) from asthmatics with (group 1) or without (group 2) specific IgE to D.p. and from non-asthmatics with (group 3) or without (group 4) were stimulated with D.p. or LPS. For LPS-mediated inhibition of IL-5 and eotaxin-2 production, LPS-induced cytokines were added to the D.p.-stimulated PBCs. IL-5 and eotaxin-2, but not eotaxin-1 and 3, were significantly increased by D.p.-stimulated-PBCs from group 1, while only eotaxin-2 was elevated in group 3. Eotaxin-2 production was found in monocytes and correlated with the level of specific IgE to D.p. LPS treatment resulted in the decrease in eotaxin-2 and IL-5 production by the D.p.-stimulated PBCs. LPS-induced IL-10 completely inhibited D.p.-stimulated production of eotaxin-2 and IL-5. The differential responses of the eotaxin family to specific antigens suggest that the predominant role of eotaxin-2 and LPS may attenuate eosinophilic inflammation by inhibiting IL-5 and eotaxin-2 synthesis through IL-10 production.

In the past few years, silica-modified titania has drawn increasing attention due to their special properties making them ideal candidates for a wide range of applications. In this study, we report a novel method for the synthesis of silica-modified titania by a sol-gel method using sodium silicate solution (1 M). The hydrolysis and condensation reactions of titanium dioxide (TiO2, Degussa Aeroxide® P25) in sodium silicate solution proceeded with citric acid (3 M) as a catalyst. The orbital shaking method was followed for the removal of sodium salt formed during the sol-gel process. Solvent exchange was carried out using methanol and hexane. Finally, chemical modification of the gel was conducted using trimethylchlorosilane followed by ambient pressure drying. The obtained silica-modified titania was characterised for nanostructural analysis using scanning electron microscopy and transmission electron microscopy. The nitrogen adsorption-desorption measurements were employed to investigate the BET surface area, pore structure and pore volume of specimens. Thermal gravimetric analysis showed exothermic peaks at temperature range of 90-190 °C representing the oxidation of organic groups from--Si-R network. The silica-modified titania showed high photocatalytic activity and an easy recovery using crystal violet as model water pollutant.

In this study, titania photocatalyst was produced from the wastewater sludge of Ti-salt flocculation. The high photocatalytic activity of titania reported was evaluated based on a single organic substrate. However, the photocatalytic activity is a substrate-specific; one photocatalyst showed different photocatalytic degradation rates for different substrates. Thus, to investigate the substrate-specific photocatalytic activity of titania, various substrates of humic acid (HA), dichloroacetic acid (DCA), rhodamine B (RhB), metsulfuron methyl (M&M) and phenol were used under simulated solar light irradiation. Results showed titania had a high activity rate for RhB, moderate activity for HA and DCA and low activity for M&M and phenol indicating substrate-specific activities. When compared with Degussa-P25, titania showed higher activity for M&M, while the opposite was observed for HA and phenol. The specific-substrate behaviour of titania could depend on specific physicochemical and electronic interactions between titania, substrates, and their intermediates compounds formed.

Eosinophilic infiltration of airway tissue is a central feature of aspirin-induced asthma (AIA). Eotaxins belong to the family of CC chemokines, which coordinate the recruitment of inflammatory cells bearing chemokine (C-C motif) receptor-3 to sites of allergic inflammation. In the present study, the levels of eotaxin-1, eotaxin-2, and eotaxin-3 following an oral aspirin provocation test (APT) were measured, and the relationship between the eotaxin level and clinical parameters in patients with asthma was evaluated.An APT was performed in patients with asthma. Twenty AIA patients and 23 aspirin-tolerant asthma (ATA) patients were identified. Plasma levels of eotaxin-1, eotaxin-2, and eotaxin-3 levels were measured by enzyme-linked immunosorbent assay in the 43 patients with asthma and in 39 control subjects.The proportion of blood eosinophils was significantly higher in asthmatic patients than in control subjects. Nasal polyps were more common in AIA patients than in ATA patients (p0.05). In addition, the eotaxin-1 level was higher in AIA and ATA patients than in control subjects (p0.01 for each). The eotaxin-2 level was higher in ATA patients than in either the AIA patients (p0.05) or control subjects (p0.01). Similarly, the eotaxin-3 level was higher in ATA patients than in control subjects. A trend toward higher plasma levels of eotaxin-1 and eotaxin-3 at baseline and at 4 h after APT administration in the ATA group was noted but was not significant. Eotaxin-2 was also higher in ATA patients than in AIA patients at baseline and at 4 h after the APT.This study shows that eotaxin-2 is differentially secreted in patients with asthma according to aspirin intolerance, and that secretion is not time-dependent in response to the APT in AIA and ATA patients. It therefore appears that eotaxin-2 may be up-regulated and may act differentially in patients with ATA.

The main drawback of flocculation process with dye wastewater is the large amount of unrecyclable sludge which needs disposal. A novel process using Ti-salt flocculation to purify wastewater was developed to produced sludge that can be calcined to produce titania. In this study, iron-doped TiO2 nanomaterial was successfully produced from sludge obtained by the flocculation of dye wastewater with a composite floculant including TiCl4 and FeSO4. The titania was characterised using scanning electron microscopy (SEM/EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD), and the photodecomposition of acetaldehyde. The XDR results showed that the anatase and rutile structures were found after sludge calcination at 550 degrees C and 640 degrees C respectively. The elemental analyses were carried out using EDX. The rutile titania sample consisted of Ti (35.7 wt.%), Fe (14.7 wt.%), O (42.3 wt.%), P (2.6 wt.%) and Ca (4.7 wt.%). The photocatalytic activity was monitored for the photodecomposition of gas acetaldehyde. Iron-doped titania seems to play an important role in increasing the photocatalytic activity under UV light irradiation.

The adsorption of pyridine onto the metal organic framework MIL-101 was investigated by experimental and theoretical methods. The amount of pyridine adsorbed on MIL-101 was extraordinarily large at 20 °C, corresponding to about 950 mg/g of dried MIL-101 and approximately half of the voids being filled. Most of the pyridine that had filled the voids was rapidly removed by evacuation at room temperature, but some of the pyridine was so strongly adsorbed that it was retained even under evacuation at 150 °C. Although IR spectra of the adsorbed pyridine indicated the adsorption of pyridine as pyridinium ions and coordinated pyridine at low temperatures, increasing the adsorption temperature induced partial cleavage of the pyridine rings. The high stabilization energy of pyridine on the coordinative unsaturated sites (CUS) of MIL-101, obtained by theoretical calculation, -103 kJ/mol, supported the strong adsorption of pyridine on the CUS.

The organic molecular porous material 1 obtained by recrystallization of cucurbit[6]uril (CB[6]) from HCl shows a high CO(2) sorption capacity at 298 K, 1 bar. Most interestingly, 1 showed the highest selectivity of CO(2) over CO among the known porous materials so far. The remarkable selectivity of CO(2) may be attributed to the exceptionally high enthalpy of adsorption (33.0 kJ/mol). X-ray crystal structure analysis of CO(2) adsorbed 1 revealed three independent CO(2) sorption sites: two in the 1D channels (A and B) and one in the molecular cavities (C). The CO(2) molecules adsorbed at sorption site A near the wall of the 1D channels interact with 1 through hydrogen bonding and at the same time interact with those at site B mainly through quadrupole-quadrupole interaction in a T-shaped arrangement. Interestingly, two CO(2) molecules are included in the CB[6] cavity (site C), interacting not only with the carbonyl groups of CB[6] but also with each other in a slipped-parallel geometry. The exceptionally selective CO(2) sorption properties of 1 may find useful applications in the pressure swing adsorption (PSA) process for CO(2) separation not only in the steel industry but also in other industries such as natural gas mining.