• Journal of Electrochemical Science and Technology
• /
• v.15 no.1
• /
• pp.67-95
• /
• 2024

Direct alcohol fuel cells (DAFCs) have gained much attention as promising energy conversion devices due to their ability to utilize alcohol as a fuel source. In this regard, Molybdenum-based electrocatalysts (Mo-ECs) have emerged as a substitution for expensive Pt and Ru-based co-catalyst electrode materials in DAFCs, owing to their unique electrochemical properties useful for alcohol oxidation. The catalytic activity of Mo-ECs displays an increase in alcohol oxidation current density by several folds to 1000-2000 mA mg_Pt^-1, compared to commercial Pt and PtRu catalysts of 10-100 mA mg_Pt^-1. In addition, the methanol oxidation peak and onset potential have been significantly reduced by 100-200 mV and 0.5-0.6 V, respectively. The performance of Mo-ECs in both acidic and alkaline media has shown the potential to significantly reduce the Pt loading. This review aims to provide a comprehensive overview of the bifunctional mechanism involved in the oxidation of alcohols and factors affecting the electrocatalytic oxidation of alcohol, such as synthesis method, structural properties, and catalytic support materials. Furthermore, the challenges and prospects of Mo-ECs for DAFCs anode materials are discussed. This in-depth review serves as valuable insight toward enhancing the performance and efficiency of DAFC by employing Mo-ECs.

• Animal Bioscience
• /
• v.37 no.8
• /
• pp.1408-1417
• /
• 2024

Objective: This study investigated the effects of dietary supplementation with lysolecithins (LPC) on growth performance, nutrient digestibility, blood profiles, immunity, and liver health in broiler chickens. Methods: A cohort of 240 one-day-old male Arbor Acres broilers of comparable weight was divided into four treatment groups, each comprising six replicates of 10 birds. The groups were defined as follows: positive control with recommended metabolizable energy (PC+ME), negative control with 90 kcal/kg reduced ME (NC+ME), PC supplemented with 300 mg/kg LPC (PC+LPC), and NC supplemented with 300 mg/kg LPC (NC+LPC). Results: LPC supplementation led to a statistically significant reduction in the feed conversion ratio (p = 0.05) and a decrease in the proportion of abdominal fat and the liver (p<0.05). Digestibility of dry matter was also enhanced (p<0.05). Malondialdehyde concentrations in the liver were significantly reduced by LPC (p<0.01), with a noteworthy interaction between energy levels and LPC affecting this reduction (p<0.05). Serum levels of interleukin-6 were reduced on day 21, and both endotoxin and interleukin-6 levels were lower on day 42. Notably, a significant interaction was observed between the energy levels and LPC on relative liver weight and endotoxin concentrations in the serum (p<0.05). Conclusion: The study concluded that LPC positively affects growth performance, nutrient digestibility, immune response, and antioxidative capacity in broiler chickens, affirming its value as a beneficial feed additive in poultry nutrition.

• Journal of the Korean Wood Science and Technology
• /
• v.52 no.2
• /
• pp.118-133
• /
• 2024

The sapwood portion of fast-growing teak is mostly ignored due to its inferior quality. One of the possibilities for utilizing sapwood waste is to convert it into activated carbon that has good adsorption capabilities. The raw materials used in this research were sapwood of 14-year-old fast-growing teak sapwood (FTS) waste, which was taken from three trees from community forests in Wonosari, Gunungkidul, Yogyakarta Special Region. FTS waste was taken from the bottom of the tree up to a height of 1.3 m. The activation process is conducted with an activation temperature of 750℃, 850℃, and 950℃. The heating duration consists of three variations: 30 min, 60 min, and 90 min. The quality evaluation parameters of activated carbon include yield, moisture content, volatile matter content, ash content, fixed carbon content, adsorption capacity of benzene, adsorption capacity of methylene blue, and adsorption capacity of iodine. The results showed that the activated carbon produced had the following quality parameters: yield of 75.61%; moisture content of 1.27%; volatile matter content of 9.98%; ash content of 5.43%; fixed carbon content of 84.58%; benzene absorption capacity of 8.58%; methylene blue absorption capacity of 87.73 mg/g; and iodine adsorption capacity of 948.19 mg/g. It can be concluded that activated carbon from FTS waste has good iodine adsorption, which fulfilled the SNI 06-3730-1995 quality standard. Due to the iodine adsorption ability of FTS waste activated carbon, the conversion of FTS waste to activated carbon is categorized as a potential method to increase the value of this material.

• Applied Chemistry for Engineering
• /
• v.35 no.5
• /
• pp.429-437
• /
• 2024

Dry reforming of methane (DRM) uses natural gas and carbon dioxide as reactants to produce hydrogen, potentially providing a solution for reducing greenhouse gas emissions and offering an alternative carbon-free energy source. However, since DRM is highly endothermic, its application and commercialization are limited by rapid temperature decrease and resulting catalyst inactivation. Consequently, research into catalyst development and reactor design to mitigate temperature decline is essential. In this study, computational fluid dynamics (CFD) is utilized to develop a multiphysics simulation platform for DRM within a fixed-bed reactor, employing two types of spherical catalysts: eggshell and uniform types. Our findings indicate that the eggshell model can maintain a higher temperature at the reactor's core than the uniform catalyst model by approximately 20 K. Furthermore, the eggshell model demonstrates superior methane conversion and hydrogen yield due to its ability to suppress excessively rapid reactions. These results underscore the benefits of eggshell catalysts in highly endothermic reactors, such as those used in DRM processes. The developed simulation platform can be used to assess various combinations of reactor and catalyst designs and further optimize their dimensions and operational protocols.

• Korean Association of Arts Management
• /
• no.58
• /
• pp.5-47
• /
• 2021

This paper is a story about five middle-aged men in their 50s who suddenly began their photographic activities as they reached middle age. In the perspective of Borudieu's cultural capital theory, this study observes five men in their 50s by implementing in-depth interviews about the motivation behind taking photographs, the experience of photography activities, and the rewards of these activities. The theory has undergone a theoretical revision with the criticism that factors other than the class can be influential. Based on these ideas, I have proceeded my study by preferentially grasping the notion of the 'field' in accordance with the specific history of Korean society. Therefore, this study sought to more specifically understand the various photographic activities of middle-class men in their 50s by referring Coskuner-Balli and Thompson's argument(2013), which revised 2018's cultural captial theory and proposed the concept of 'subordinate cultural capital' and 'leisure capital' who proposed by Backlund, E. A. & Kuentzel, W. F.(2013). As a middle-class men in their 50s, research participants have grown up and worked in a social atmosphere where economic capital is recognized as an individual's ability. However, they are faced with the value that the knowledge and taste towards culture and arts is one's identity. In addition to the subjective deprivation that arises from this situation, the lifespan characteristic of their age that it is on the brink of the old age appeared to have influenced them to put their psychological motivation immediately into practice. Economic capital was the main conversion terms to move form interest to practice, which includes 'time' as a resource as well as money. With the cultural practices being expanded since their creation of photographs, the reason that these expansions can be maintained more actively lies in their identity as 'cultural artist' that is consolidated in new relationships in the sharing of photographic activities. In this way, photographic activities grant a symbolic status of 'a middle-aged man who actively builds and expresses his identity' through the conversion of accumulating cultural capital and the conversion into social capital. Furthermore, the recognized scope of the symbolic capital acquired by the research participants is in the domain of the private life that is family and acquaintance. Especially, they were gaining a great psychological reward from their children's recognition that they are not just a 'breadwinner' but 'dad who cultivates himself with a culture and arts'. Accordingly, by considering that 'generation' other than class can be a meaningful discussion point when understanding Korea society from the perspective of cultural theory, this study is meaningful that a more flexible understanding of cultural theory can give a glimpse into the possibility of a more specific and diverse approach that will arise in the discussion of culture and arts education.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.14 no.1
• /
• pp.81-94
• /
• 2003

Objectives：Developmental reading disorder is a condition which manifests significant developmenttal delay in reading ability or persistent errors. About 3-7% of school-age children have this condition. The purpose of the present study was to validate the diagnostic values of Word/Nonword Reading Test and Letter-Symbol Discrimination Task for the purpose of overcoming the caveats of Basic Learning Skills Test. Methods：Sixty-three reading-disordered patients(mean age 10.48 years old) and sex, age-matched 77 normal children(mean age 10.33 years old) were selected by clinical evaluation and DSM-IV criteria. Reading I and II of Basic Learning Skills Test, Word/Nonword Reading Test, and Letter-Symbol Discrimination Task were carried out to them. Word/Nonword Reading Test：One hundred usual highfrequency words and one hundred meaningless nonwords were presented to the subjects within 1.2 and 2.4 seconds, respectively. Through these results, automatized phonological processing ability and conscious letter-sound matching ability were estimated. Letter-Symbol Discrimination Task：mirror image letters which reading-disordered patients are apt to confuse were used. Reliability, concurrent validity, construct validity, and discriminant validity tests were conducted. Results：Word/Nonword Reading Test：the reliability(alpha) was 0.96, and concurrent validity with Basic Learning Skills test was 0.94. The patients with developmental reading disorders differed significantly from normal children in Word/Nonword Reading Test performances. Through discriminant analysis, 83.0% of original cases were correctly classified by this test. Letter-Symbol Discrimination Task：the reliability(alpha) was 0.86, and concurrent validity with Basic Learning Skills test was 0.86. There were significant differences in scores between the patients and normal children. Factor analysis revealed that this test were composed of saccadic mirror image processing, global accuracy, mirror image processing deficit, static image processing, global vigilance deficit, and inattention-impulsivity factors. By discriminant analysis, 87.3% of the patients and normal children were correctly classified. Conclusion：The patients with developmental reading disorders had deficits in automatized visuallexical route, morpheme-phoneme conversion mechanism, and visual information processing. These deficits were reliably and validly evaluated by Word/Nonword Reading Test and Letter-Symbol Discrimination Task.

• Journal of Intelligence and Information Systems
• /
• v.17 no.2
• /
• pp.119-128
• /
• 2011

The Sensor technology and portable device capability able to collect recent user information and the information about the surrounding environment haven been highly developed. A user can be made use of various contents and the option is also extending with this technology development. In particular, the initial portable device had simply a call function, but now that has evolved into 'the 4th screen' which including movie, television, PC ability. also, in the past, a portable device to provided only the services of a SMS, in recent years, it provided to interactive video service, and it include technology which providing various contents. Also, it is rising as media which leading the consumption of contents, because it can be used anytime, anywhere. However, the contents available for the nature of user's handheld devices are limited. because it is very difficult for making the contents separately according to various device specification. To find a solution to this problem, the study on one contents from several device has been progressing. The contents conversion technology making use of the profile of device out of this study comes to the force and profile study has been progressing for this. Furthermore, Demand for a user is also increased and the study on the technology collecting, analyzing demands has been making active progress. And what is more, Grasping user's demands by making use of this technology and the study on the technology analyzing, providing contents has been making active progress as well. First of all, there is a method making good use of ZigBee, Bluetooth technology about the sensor for gathering user's information. ZigBee uses low-power digital radio for wireless headphone, wireless communication network, and being utilized for smart energy, automatic home system, wireless communication application and wireless sensor application. Bluetooth, as industry standards of PAN(Personal Area Networks), is being made of use of low power wireless device for the technology supporting data transmission such as drawing file, video file among Bluetooth device. With analyzing the collected information making use of this technology, it utilizes personalized service based on network knowledge developed by ETRI to service contents tailor-made for a user. Now that personalized service builds up network knowledge about user's various environments, the technology provides context friendly service constructed dynamically on the basis of this. The contents to service dynamically like this offer the contents that it converses with utilizing device profile to working well. Therefore, this paper suggests the system as follow. It collects the information, for example of user's sensitivity, context and location by using sensor technology, and generates the profile as a means of collected information as sensor. It collects the user's propensity to the information by user's input and event and generates profile in the same way besides the gathered information by sensor. Device transmits a generated profile and the profile about a device specification to proxy server. And proxy server transmits a profile to each profile management server. It analyzes profile in proxy server so that it selects the contents user demand and requests in contents server. Contents server receives a profile of user portable device from device profile server and converses the contents by using this. Original source code of contents convert into XML code using the device profile and XML code convert into source code available in user portable device. Thus, contents conversion process is terminated and user friendly system is completed as the user transmits optimal contents for user portable device.

• Asian-Australasian Journal of Animal Sciences
• /
• v.24 no.12
• /
• pp.1718-1728
• /
• 2011

Two experiments were conducted to investigate the in vitro ability of keratinase to hydrolyze soybean glycinin and ${\beta}$-conglycinin and to evaluate the in vivo effects of keratinase when included in corn-soybean diets with different levels of crude protein and fed to nursery pigs. In experiment 1, a saturated keratinase solution (1 ml) was added to two blank controls of either glycinin or ${\beta}$-conglycinin resulting in the hydrolysis of 94.74% glycinin and 88.89% ${\beta}$-conglycinin. In experiment 2, 190 pigs (8.3${\pm}$0.63 kg BW) were allotted to one of four treatments in a 2${\times}$2 factorial arrangement on the basis of body weight, and sex was balanced among the pens. The effects of crude protein (19 vs. 22%) and keratinase (0 vs. 0.05%) were studied. Each treatment was applied to six pens with seven (two pens) or eight pigs per pen. Pigs were fed the experimental diets for 21 d. Weight gain and feed conversion ratio were improved (p<0.05) with keratinase supplementation while feed intake was reduced (p<0.05). Keratinase supplementation increased (p<0.05) the apparent total tract digestibility of dry matter, energy, crude protein and phosphorus. Keratinase supplementation also increased n-butyric acid in the cecum and colon, lactobacilli and total anaerobe counts in the colon as well as the ratio of villus height to crypt depth in the ileum. Additionally, fecal score, ammonia nitrogen and branch chain volatile fatty acids in the colon, E. coli and total aerobe counts in the colon, crypt depth in the jejunum and ileum as well as serum interleukin-1 and interleukin-6 concentrations were also decreased (p<0.05) by keratinase supplementation. A reduction in dietary crude protein decreased (p<0.05) colon ammonia nitrogen concentration and cecal propionic acid and branch chain volatile fatty acid concentrations. In addition, cecal E. coli counts, colon total anaerobe counts, ileal crypt depth, and serum interleukin-1 and interleukin-6 concentrations were also decreased (p<0.05) with the reduction of dietary crude protein. With the exception of fecal scores, there were no significant interactions between crude protein and keratinase. This study provides evidence that dietary keratinase supplementation improved nursery pig performance by improving intestinal morphology and ecology, thus improving nutrient digestibility and alleviating the inflammatory response.

• Journal of Life Science
• /
• v.28 no.7
• /
• pp.778-785
• /
• 2018

Autophagy is a complex signaling process and has been implicated in tumor suppression and anticancer therapy resistance. Autophagy can produce tumor-suppressive effect by inducing autophagic cell death, either in collaboration with apoptosis. In this current study, we found that celecoxib (CCB), a nonsteroidal anti-inflammatory drug (NSAID) with multifaceted effects, induced autophagy including enhanced LC3 conversion (LC3-I to LC3-II) and reduced autophagy substrate protein p62 level in multidrug-resistant (MDR) cancer cells. CCB sensitized human multidrug resistant (MDR) cancer cells to the ansamycin-based HSP90 inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG), a benzoquinoid ansamycin, which causes the degradation of several oncogenic and signaling proteins, by inducing autophagic cell death and apoptosis. CCB significantly augmented 17-AAG-mediated level of LC3-II/LC-I, indicating the combined effect of 17-AAG and CCB on the induction of autophagy. Autophagic degradation of mutant p53 (mutp53) and activation of caspase-3 in 17-AAG-treated MDR cells were accelerated by CCB. Inhibition of caspase-3-mediated apoptotic pathway by Z-DEVD-FMK, a caspase-3 inhibitor, did not completely block CCB-induced cell death in MCF7-MDR cells. In addition, treatment of MDR cells with Z-DEVD-FMK failed to prevent activation of autophagy by combined treatment with 17-AAG and CCB. Based on our findings, the ability of clinically used drug CCB to induce autophagy has important implications for its development as a sensitizing agent in combination with Hsp90 inhibitor of MDR cancer.

• Applied Chemistry for Engineering
• /
• v.9 no.3
• /
• pp.355-360
• /
• 1998

Reduction activity of precious metal-loaded HZSM-5 for NO has been studied and was compared to that of Cu-HZSM-5 in the presence of excess oxygen. It was found that among the catalysts used in this study, Ru-HZSM-5 was the most active catalyst for the reduction of NO to $N_2$ in the absence of hydrocarbon reductant. The highest conversion obtained was 45%. No severe inhibition of water vapor to the reduction was observed. It is suggested that the higher catalytic activity of Ru-HZSM-5 may result from the better ability to oxidize NO to $NO_2$ in the presence of excess oxygen. A proposed reaction mechanism for the reduction of NO to $N_2$ in the presence of excess oxygen is that NO is oxidized to $NO_2$ on the surface of Ru-HZSM-5 catalyst and the adsorbed $NO_2$ on the surface is then decomposed to $N_2$. $NO_2$ is supposed to the reaction.