• Journal of Electrochemical Science and Technology
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• v.7 no.3
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• pp.218-227
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• 2016

The light harvesting efficiency is counted as an important factor in the power conversion efficiency of DSSCs. There are two measures to improve this parameter, including enhancing the dye-loading capacity and increasing the light trapping in the photoanode structure. In this paper, these tasks are addressed by introducing a macro-porous silicon (PSi) substrate as photoanode. The effects of the novel photoanode structure on the DSSC performance have been investigated by using energy dispersive X-ray spectroscopy, photocurrent-voltage, UV-visible spectroscopy, reflectance spectroscopy, and electrochemical impedance spectroscopy measurements. The results indicated that bigger porosity percentage of the PSi structure improved the both anti-reflective/light-trapping and dye-loading capacity properties. PSi based DSSCs own higher power conversion efficiency due to its remarkable higher photocurrent, open circuit voltage, and fill factor. Percent porosity of 64%, PSi(III), resulted in nearly 50 percent increment in power conversion efficiency compared with conventional DSSC. This paper showed that PSi can be a good candidate for the improvement of light harvesting efficiency in DSSCs. Furthermore, this study can be considered a valuable reference for more investigations in the design of multifunctional devices which will profit from integrated on-chip solar power.

• Journal of Microbiology
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• v.43 no.1
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• pp.11-16
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• 2005

Matrix metalloproteinase (MMP)-9 plays an important role in the pathogenesis of bronchial asthma. Neovastat, having significant antitumor and antimetastatic properties, is classified as a naturally occurring multifunctional antiangiogenic agent. We evaluated the therapeutic effect of Neovastat on airway inflammation in a mouse model of asthma. BALB/c mice were immunized subcutaneously with ovalbumin (OVA) on days 0, 7, 14, and 21 and challenged with inhaled OVA on days 26, 29, and 31. Neovastat was administrated by gavage (5 mg/kg body weight) three times with 12 h intervals, beginning 30 min before OVA inhalation. On day 32, mice were challenged with inhaled methacholine, and enhanced pause (Penh) was measured as an index of airway hyperresponsiveness. The severity of airway inflammation was determined by differential cell count of bronchoalveolar lavage (BAL) fluid. The MMP-9 concentration in BAL fluid samples was measured by ELISA, and MMP-9 activity was measured by zymography. The untreated asthma group showed an increased inflammatory cell count in BAL fluid and Penh value compared with the normal control group. Mice treated with Neovastat had significantly reduced Penh values and inflammatory cell counts in BAL fluid compared with untreated asthmatic mice. Furthermore, mice treated with Neovastat showed significantly reduced MMP-9 concentrations and activity in BAL fluid. These results demonstrate that Neovastat might have new therapeutic potential for airway asthmatic inflammation.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.12
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• pp.767-775
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• 2014

New material design has obtained tremendous attention in material science community as the performance of new materials, especially in nano length scale, could be greatly improved to applied in modern industry. In certain conditions limiting experimental synthesis of these new materials, new approach by computer simulation has been proposed to be applied, being able to save time and cost. Recent development of computer systems with high speed, large memory, and parallel algorithms enables to analyze individual atoms using first principle calculation to predict quantum phenomena. Beyond the quantum level calculations, mesoscopic scale and continuum limit can be addressed either individually or together as a multi-scale approach. In this article, we introduced current endeavors on material design using analytical theory and computer simulations in multi-length scales and on multi-physical properties. Some of the physical phenomena was shown to be interconnected via a cross-link rule called 'cross-property relation'. It is suggested that the computer simulation approach by multi-physics analysis can be efficiently applied to design new materials for multi-functional characteristics.

• Textile Coloration and Finishing
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• v.33 no.3
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• pp.161-167
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• 2021

Polymer nanocomposite is considered a great alternative to solve the limitations that exist in a simple combination material, as well as to produce multifunctional and high-performance results. In this research, PVA/bentonite nanocomposite films were prepared based on the presence or absence of modification of nano-clay(bentonite) a SUPERGEL^® product, modification conditions and content, and the structural variation of the prepared PVA/bentonite nanocomposite films were examined. The effect of variations in the internal structure of the nanocomposite on mechanical and thermal properties was investigated. As a result of evaluating the thermal characteristics of the PVA/bentonite nanocomposite film based on the concentration of the modified bentonite, it was verified that the thermal characteristics and stability were improved because of interaction between the polymer and the modified nano-clay.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.2
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• pp.53-58
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• 2022

One of the most promising emerging technologies for the next generation of nonvolatile memory devices based on resistive switching (RS) is the resistive random-access memory mechanism. To date, RS effects have been found in many transition metal oxides. However, no clear evidence has been reported that ZnO-based resistive transition mechanisms could be associated with strong correlation effects. Here, we investigated N, F-co-doped ZnO (NFZO), which shows bipolar RS. Conducting micro spectroscopic studies on exposed surfaces helps tracking the behavioral change in systematic electronic structural changes during low and high resistance condition of the material. The significant difference in electronic conductivity was observed to attribute to the field-induced oxygen vacancy that causes the metal-insulator Mott transition on the surface. In this study, we showed the strong correlation effects that can be explored and incorporated in the field of multifunctional oxide electrons devices.

• Journal of Microbiology and Biotechnology
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• v.32 no.9
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• pp.1098-1102
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• 2022

The placenta is a captivating multifunctional organ of fetal origin and plays an essential role during pregnancy by intimately connecting mother and baby. This study explicates placental pathology and information about 25 placentas collected from the mothers infected with novel coronavirus (SARS-COV-2). So far, congenital transmission of SARS-CoV-2 seems to be remarkably uncommon in spite of many cases of COVID-19 during pregnancy. Out of the 25 placental tissue samples collected, none has shown gene expression of SARS-CoV-2 when confirmed by RT-PCR. At the same time, nasal and throat swab samples collected from newborns of SARS-CoV-2-positive mothers correspondingly tested negative by RT-PCR. The shielding properties of placental barriers against viral infections from mothers to newborns remains a mystery. Major histopathological findings have been recorded as choriodecidual tissue with necrosis, intramural fibrin deposition, chorionic villi with fibrosis, and calcification. Moreover, although recent findings are insufficient to prove direct placental transmission of COVID-19, the abundance of angiotensin-converting enzymes-2 (ACE-2) on the placental surface could potentially contribute to unpleasant outcomes during pregnancy as SARS-CoV-2 gains access to human cells via ACE-2. Finally, the significance of these findings is vague and needs further study.

• Structural Engineering and Mechanics
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• v.81 no.3
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• pp.267-280
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• 2022

Multiscale structure has attracted significant interest due to its high stiffness/strength to weight ratios and multifunctional performance. However, most of the existing concurrent topology optimization works are carried out under deterministic load conditions. Hence, this paper proposes a robust concurrent topology optimization method based on the bidirectional evolutionary structural optimization (BESO) method for the design of structures composed of periodic microstructures subjected to uncertain dynamic loads. The robust objective function is defined as the weighted sum of the mean and standard deviation of the module of dynamic structural compliance with constraints are imposed to both macro- and microscale structure volume fractions. The polynomial chaos expansion (PCE) method is used to quantify and propagate load uncertainty to evaluate the objective function. The effective properties of microstructure is evaluated by the numerical homogenization method. To release the computation burden, the decoupled sensitivity analysis method is proposed for microscale design variables. The proposed method is a non-intrusive method, and it can be conveniently extended to many topology optimization problems with other distributions. Several numerical examples are used to validate the effectiveness of the proposed robust concurrent topology optimization method.

• Korean Journal of Agricultural Science
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• v.49 no.3
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• pp.463-481
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• 2022

Phosphorous (P) is considered to be one of the key essential elements demanded by crop plants. Approximately 70 - 90% of phosphatic fertilizers applied to crops are fixed in soil as Ca, Fe, and Al metal cations, which are insoluble and thus not readily available for plant uptake. Therefore, most soils are deficient in plant available P. This is usually rectified by applying phosphate fertilizers continuously, although this is not economically viable or environmentally acceptable. The present paper reviews the mechanisms involved with phosphate solubilization and mineralization by phosphate solubilizing microorganisms (PSMs) with the associated factors that determine the success. PSMs are effectively involved in mediating the bioavailability of soil P. Their contribution includes mineralization of organic P solubilization of inorganic P minerals, and storing sizable amounts of P in biomass through different mechanisms such as the production of organic and inorganic acids, H₂S, siderophores, exopolysaccharides, and production of enzymes such as phosphatases, phytase, and phosphonatases/C-P lyases, which are capable of chelating the metal ions, forming complexes, and making plant available P. PSMs manifest a wide range of metabolic functions in different environments, resulting in significantly higher plant growth, enhanced soil properties, and increased biological activities. Therefore, development of bio-inoculants with efficient novel PSM strains and further investigations on exploring such strains from diverse ecological niches with multifunctional plant-growth-promoting traits are needed.

• Journal of the Korean Society of Clothing and Textiles
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• v.46 no.3
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• pp.530-544
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• 2022

Titanium exhibits substantial corrosion resistance, strength, and ductility, with a specific gravity of approximately 4.5 and a melting point of approximately 1800℃. It is currently used in aircraft parts and space development. This study considered the thermal characteristics, stealth effects of infrared thermal imaging cameras, electromagnetic shielding, and electrical conductivity of Ti-sputtered materials. Base materials of different densities and types were treated using titanium sputtering. Infrared thermal imaging showed a better stealth effect when the titanium layer was directed toward the outside. The film sample presented a better stealth effect than the fabrics did. In each of the samples subjected to titanium sputtering, when the titanium layer was directed outward, the untreated sample or exposed titanium layer showed surface temperatures lower than those of the samples with the titanium layer oriented toward the heat source. Additionally, after the titanium sputtering treatment, the films conducted electricity (low resistance) better than the fabrics did. All titanium-sputtered specimens presented reduced electromagnetic wave transmission and significantly reduced infrared transmission. These results are expected to apply to military uniforms (soldiers' protective clothing to gain the upper hand on the battlefield), medical sensors, multifunctional intelligent textiles and etc.

• International Journal of Industrial Entomology and Biomaterials
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• v.46 no.2
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• pp.25-33
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• 2023

The liver, a multifunctional organ, plays a vital role in maintaining overall health and well-being by regulating metabolism, detoxification, nutrient storage, hormone balance, and immune function. Liver diseases, such as hepatitis, cirrhosis, fatty liver disease, and liver cancer, have significant clinical implications and remain a global health concern. This article reviews the therapeutic potential of silkworm larvae (Bombyx mori) and explores their underlying molecular mechanisms in protecting against liver diseases. Silkworm larvae are rich in proteins, vitamins, minerals, and n-3 fatty acids, making them a promising candidate for therapeutic applications. The anti-inflammatory mechanisms of silkworm larvae involve modulating the production of cytokine such as TNF-α and interleukins, inflammatory enzymes including cyclooxygenase-2 and macrophage polarization, thereby attenuating liver inflammation. Silkworm larvae also exhibit anti-oxidative effects by scavenging free radicals, reducing intracellular reactive oxygen species and enhancing the liver's antioxidant defense system. Moreover, silkworms have been reported to decrease the serum alcohol concentration and lipid accumulation. Understanding the therapeutic properties of silkworm larvae contributes to the development of innovative strategies for liver injury prevention and treatment. Further research is warranted to elucidate the precise signaling pathways involved in the anti-inflammatory and anti-oxidative effects of silkworm larvae, paving the way for potential therapeutic interventions in liver diseases.