Disparities in exploitative and exploratory patenting performance across regions: Focusing on the roles of agglomeration externalities

We try to identify the determinants of regional variation in both exploitative and exploratory innovative competencies. Hereby, we focus on how a knowledge-creation mechanism with specialized externalities differs from one with diversified externalities. Innovative competence in the US is measured by local patenting performance; exploitative and exploratory patenting performances are distinguished by the degree of backward citation. Based on the extended knowledge-production function, including the two agglomeration externalities, our findings show that specialized externalities are associated with exploitation, while diversified externalities are positively related with both exploration and exploitation, regardless of industrial sectors.     

Evaluation of physicochemical properties and fermenting qualities of apple wines added with medicinal herbs

To evaluate the possibility for development of apple wine containing medicinal herbs, we have prepared ‘Fuji’ apple (Malus domestica) wines containing pine (Pinus densiflora Siebold et Zuccarini) needle and hwanggi (Radix Astragali)/mistletoe (Viscum album). Normal apple wine was fermented rapidly, but after 40 days fermentation/maturation, the final ethanol content, pH, total acidity, and contents of sugar/organic acid showed similar levels in 3 kinds of apple wines. In other hands, the total phenols content, antocyanins content, and brightness were higher in apple-pine wine and apple-herb wine than in normal apple wine. Apple-herb wine had higher values in total phenol contents, brightness, free amino acid contents, and quenching activity for ABTS free radicals than normal apple wine, and had similar sensory evaluation values with normal apple wine. Taken together, it is supposed that hwanggi and mistletoe might provide functional components to normal apple wine and might be applied to development of functional apple wines.     

Cloning and characterization of the Hansenula polymorpha homologue of the Saccharomyces cerevisiae MNN9 gene

A gene homologous to Saccharomyces cerevisiae MNN9 has been cloned and characterized in the methylotrophic yeast Hansenula polymorpha. This gene was cloned from a H. polymorpha genomic DNA library using the S. cerevisiae MNN9 gene as a probe. The H. polymorpha MNN9 homologue (HpMNN9) contained a 1062 bp open reading frame encoding a predicted protein of 354 amino acids. The deduced amino acid sequence showed 58% and 51% identity, respectively, with the S. cerevisiae and Candida albicans Mnn9 proteins. Disruption of HpMNN9 leads to phenotypic effects suggestive of cell wall defects, including detergent sensitivity and hygromycin B sensitivity. The hygromycin B sensitivity of S. cerevisiae mnn9 null mutant was complemented in the presence of the HpMNN9 gene. The DNA sequence of the H. polymorpha homologue has been submitted to GenBank with the Accession No. AF264786.     

The catalytic activity and surface characterization of Ln2B2O7 (Ln=Sm, Eu, Gd and Tb; B=Ti or Zr) with pyrochlore structure as novel CH4 combustion catalyst

Ln₂B₂O₇ (Ln=Sm, Eu, Gd and Tb; B=Zr or Ti) with pyrochlore structure was prepared by sol–gel method for the high-temperature catalytic combustion. The crystal structure of Ln₂B₂O₇ was identified by XRD and their surface area was about 4 m²/g after calcinations at 1200 °C. Catalytic activity of methane combustion was observed for Ln₂Zr₂O₇ series and the best catalyst was Sm₂Zr₂O₇. Its relative reaction rate per unit surface area at 600 °C was 2 cm³/m² min, which was twice higher than that of Mn-substituted Sr hexaaluminate. From surface analysis by XPS, the low binding energy of each Ln element of Ln₂Zr₂O₇ compared to that of Ln₂Ti₂O₇, gave the catalytic activity of methane combustion.     

Degradation of Thermal Barrier Coatings by Fuel Impurities and CMAS: Thermochemical Interactions and Mitigation Approaches

Degradation of free-standing yttria-stabilized zirconia (YSZ) and CoNiCrAlY coatings (300 μm) due to V₂O₅ and a laboratory-synthesized CMAS was investigated at temperatures up to 1400 °C. Reactions, phase transformations, and microstructural development in coatings were examined by using x-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The molten deposits destabilized the YSZ and reacted with the thermally grown oxide with various phase transformations and reaction product formation. A dense, continuous environmental barrier overlay, based on oxides, applied by electrophoretic deposition was effective in mitigating the molten deposit attack. Enriching CMAS composition with Al promoted the crystallization of anorthite platelets and MgAl₂O₄ spinel, and mitigated CMAS ingression. EPD MgO overlay was also effective in protection against V₂O₅ melt by formation of magnesium vanadates. EPD alumina overlay deposited on thermal barrier coatings with APS 8YSZ and bond-coated IN939 superalloy retained its adhesion and structural integrity after prolonged furnace thermal cycle test at 1100 °C.     

Measurement of zeta potential of macroscopic surfaces with Navier velocity slip exploiting electrokinetic flows in a microchannel

A method devised to measure the zeta potential of macroscopic surfaces with Navier velocity slip non-destructively exploiting electrokinetic flows in a microchannel. For an accurate as well as facile determination of zeta potential using this method, we need a simple relationship between zeta potential and streaming potential for electrokinetic flows in microchannels with consideration of the possibility of the Navier velocity slip. In the present investigation, we derive a semi-analytic formula for this relationship based on a one-dimensional modeling of electrokinetic flow in microchannels, which is as accurate as the numerical solution of the full governing partial differential equations. This formula is expected to allow accurate measurements of zeta potential of various macroscopic surfaces with Navier velocity slip.     

Conjoint analysis for luxury brand outlet malls in Korea with consideration of customer lifetime value

As Asian economies have grown rapidly, Asia has become a new leading market of the luxury goods industry. This paper used conjoint analysis (CA) for the optimal design of a luxury brand outlet mall to maximize the customer lifetime value (CLV). This approach complements a simple CA by considering CLV. The proposed approach is then applied to designing a suburban luxury brand outlet mall in Korea, a new concept to Korea. The results indicate that the optimal design for the outlet mall is the medieval European-style mall, with the linkage to Natural Tourism, which consists of the restaurants with delicious food and the stores with similar ratio between masstige and luxury brands.     

Intrinsic Kinetics of Chlorination of WO<Subscript>3</Subscript> Particles With Cl<Subscript>2</Subscript> Gas Between 973 K and 1223 K (700 °C and 950 °C)

Chlorination is one of the methods applied in extractive metallurgy for the treatment of minerals to obtain valuable metals, such as titanium and zirconium. The possibility of applying chlorination metallurgy to other metals such as tungsten was the major aim of this study. The kinetics of the chlorination of tungsten oxide (WO₃) particles has been investigated by thermogravimetry between 973 K and 1223 K (700 °C and 950 °C) and for partial pressures of chlorine ranging from 15 to 70 kPa. The starting temperature for the reaction of WO₃ with chlorine is determined to be about 920 K (647 °C). The influence of chlorine diffusion through the bulk gas phase and through the particle interstices in the overall rate was analyzed. In the absence of these two mass-transfer steps, a reaction order of 0.5 with respect to chlorine partial pressure, and an activation energy of 183 kJ/mol were determined. For tungsten oxide particles of less than 50-μm size, a complete rate expression has been obtained.