Purification of Sulphate Leach Liquor of Spent Raneynickel Catalyst Containing Al and Ni by Solvent Extraction with Organophosphorus-Based Extractants

Rao, Satunuri Venkateswar,Yang, Dong Hyo,Sohn, Jeong Soo,Kim, Soo-Kyung The Scientific World Journal 2012 The Scientific World Journal Vol.2012 No.-

<P>Solvent extraction (SX) separation of Al from Ni sulphate leach liquor (LL) of spent Raneynickel catalyst containing 0.12 M Al and 1.448 M Ni using organophosphorus extractants has been investigated. Optimization of process conditions includes aqueous pH, extractant concentration, phase ratio, and stripping. Comparison of Al extraction efficiency with 0.45 M extractant concentration for TOPS 99, PC 88 A, and Cyanex 272 at an equilibrium pH of 2.23 was 81.8%, 98.6%, and 75%, respectively. The corresponding coextraction of Ni was 0.65, 0.6, and 0.9. Among the three extractants screened, PC 88A showed better extraction efficiency for Al at lower pH values than the others. Using 0.45 M PC 88 A, extraction isotherm was obtained at an aqueous-to-organic (A : O) phase ratio of 1 : 1–3 and O : A ratio of 1 : 1–5, which predicted possible separation of Al in 2 stages at A/O ratio of 2. Quantitative stripping was achieved by H<SUB>2</SUB>SO<SUB>4</SUB>.</P>

Seasonality of Tropical Instability Waves and Its Feedback to the Seasonal Cycle in the Tropical Eastern Pacific

Im, Seul-Hee,An, Soon-Il,Lengaigne, Matthieu,Noh, Yign The Scientific World Journal 2012 The Scientific World Journal Vol.2012 No.-

<P>This study investigated the seasonality of tropical instability waves (TIWs) and its feedback to the seasonal cycle in the tropical eastern Pacific using a high-resolution ocean model covering 1958–2007. The climatological mean of the TIWs featured intraseasonal fluctuations, implying that TIWs are not occurring randomly, but their amplitude is partly in phase from one year to another. This seasonality of TIW activity is attributed to their dependency on the seasonal mean variation of current and temperature. Energy conversion analysis confirmed that the strong variability of TIWs near 4°N was due to the barotropic energy conversion associated with the large meridional shear of NECC and SEC and that at another pole near 2°N was due to the baroclinic energy conversion associated with the temperature front in the mixed layer. The former and latter poles are somehow largely responsible for amplifying the dynamic and thermal eddies of TIWs, respectively. The intensified TIWs during a boreal fall increase the tropical eastern Pacific SST by associating the warm thermal advection by anomalous currents, with a rate of up to 1°C/month in September. Therefore, this leads to interactive feedback between seasonal and intraseasonal variations, that is, TIWs in the tropical eastern Pacific.</P>

Development of Methane and Nitrous Oxide Emission Factors for the Biomass Fired Circulating Fluidized Bed Combustion Power Plant

Cho, Chang-Sang,Sa, Jae-Hwan,Lim, Ki-Kyo,Youk, Tae-Mi,Kim, Seung-Jin,Lee, Seul-Ki,Jeon, Eui-Chan The Scientific World Journal 2012 The Scientific World Journal Vol.2012 No.-

<P>This study makes use of this distinction to analyze the exhaust gas concentration and fuel of the circulating fluidized bed (CFB) boiler that mainly uses wood biomass, and to develop the emission factors of Methane (CH<SUB>4</SUB>), Nitrous oxide (N<SUB>2</SUB>O). The fuels used as energy sources in the subject working sites are Wood Chip Fuel (WCF), RDF and Refused Plastic Fuel (RPF) of which heating values are 11.9 TJ/Gg, 17.1 TJ/Gg, and 31.2 TJ/Gg, respectively. The average concentrations of CH<SUB>4</SUB> and N<SUB>2</SUB>O were measured to be 2.78 ppm and 7.68 ppm, respectively. The analyzed values and data collected from the field survey were used to calculate the emission factor of CH<SUB>4</SUB> and N<SUB>2</SUB>O exhausted from the CFB boiler. As a result, the emission factors of CH<SUB>4</SUB> and N<SUB>2</SUB>O are 1.4 kg/TJ (0.9–1.9 kg/TJ) and 4.0 kg/TJ (2.9–5.3 kg/TJ) within a 95% confidence interval. Biomass combined with the combustion technology for the CFB boiler proved to be more effective in reducing the N<SUB>2</SUB>O emission, compared to the emission factor of the CFB boiler using fossil fuel.</P>

The Future of Butyric Acid in Industry

Dwidar, Mohammed,Park, Jae-Yeon,Mitchell, Robert J.,Sang, Byoung-In The Scientific World Journal 2012 The Scientific World Journal Vol.2012 No.-

<P>In this paper, the different applications of butyric acid and its current and future production status are highlighted, with a particular emphasis on the biofuels industry. As such, this paper discusses different issues regarding butyric acid fermentations and provides suggestions for future improvements and their approaches.</P>

Sensitivity and Selectivity on Aptamer-Based Assay: The Determination of Tetracycline Residue in Bovine Milk

Jeong, Sohee,Rhee Paeng, Insook The Scientific World JOURNAL 2012 The Scientific World Journal Vol.2012 No.-

<P>A competitive enzyme-linked aptamer assay (ELAA) to detect tetracycline in milk was performed by using two different aptamers individually; one is 76 mer-DNA aptamer and the other is 57 mer-RNA aptamer. The best optimum condition was obtained without monovalent ion, Na<SUP>+</SUP> and also by adding no Mg<SUP>2+</SUP> ion in the assay buffer, along with RT incubation. The optimized ELAA showed a good sensitivity (LOD of 2.10 × 10<SUP>−8</SUP> M) with a wide dynamic range (3.16 × 10<SUP>−8</SUP> M ~ 3.16 × 10<SUP>−4</SUP> M). In addition, the average R.S.D. across all data points of the curve was less than 2.5% with good recoveries (~101.8%) from the milk media. Thus, this method provides a good tool to monitor tetracycline in milk from MRLs' point of view. However, this ELAA method was not superior to the ELISA method in terms of specificity. This paper describes that it does not always give better sensitivity and specificity in assays even though aptamers have several advantages over antibodies and have been known to be good binders for binding assays.</P>

A Simple Approach for Measuring Emission Patterns of Vapor Phase Mercury under Temperature-Controlled Conditions from Soil

Kim, Ki-Hyun,Yoon, Hye-On,Jung, Myung-Chae,Oh, Jong-Min,Brown, Richard J. C. The Scientific World Journal 2012 The Scientific World Journal Vol.2012 No.-

<P>In an effort to study the possible effects of climate change on the behavior of atmospheric mercury (Hg), we built a temperature–controlled microchamber system to measure its emission from top soils. To this end, mercury vapour emission rates were investigated in the laboratory using top soil samples collected from an urban area. The emissions of Hg, when measured as a function of soil temperature (from ambient levels up to 70°C at increments of 10°C), showed a positive correlation with rising temperature. According to the continuous analyses of the Hg vapor given off by the identical soil samples, evasion rate diminished noticeably with increasing number of repetitions. The experimental results, if examined in terms of activation energy (Ea), showed highly contrasting patterns between the single and repetitive runs. Although the results of the former exhibited Ea values smaller than the vaporization energy of Hg (i.e., <14 Kcal mol<SUP>−1</SUP>), those of the latter increased systematically with increasing number of repetitions. As such, it is proposed that changes in the magnitude of Ea values can be used as a highly sensitive criterion to discriminate the important role of vaporization from other diverse (biotic/abiotic) processes occurring in the soil layer.</P>

A Study on Methane and Nitrous Oxide Emissions Characteristics from Anthracite Circulating Fluidized Bed Power Plant in Korea

Lee, Seehyung,Kim, Jinsu,Lee, Jeongwoo,Jeon, Eui-Chan The Scientific World Journal 2012 The Scientific World Journal Vol.2012 No.-

<P>In order to tackle climate change effectively, the greenhouse gas emissions produced in Korea should be assessed precisely. To do so, the nation needs to accumulate country-specific data reflecting the specific circumstances surrounding Korea's emissions. This paper analyzed element contents of domestic anthracite, calorific value, and concentration of methane (CH<SUB>4</SUB>) and nitrous oxide (N<SUB>2</SUB>O) in the exhaust gases from circulating fluidized bed plant. The findings showed the concentration of CH<SUB>4</SUB> and N<SUB>2</SUB>O in the flue gas to be 1.85 and 3.25 ppm, respectively, and emission factors were 0.486 and 2.198 kg/TJ, respectively. The CH<SUB>4</SUB> emission factor in this paper was 52% lower than default emission factor presented by the IPCC. The N<SUB>2</SUB>O emission factor was estimated to be 46% higher than default emission factor presented by the IPCC. This discrepancy can be attributable to the different methods and conditions of combustion because the default emission factors suggested by IPCC take only fuel characteristics into consideration without combustion technologies. Therefore, Korea needs to facilitate research on a legion of fuel and energy consumption facilities to develop country-specific emission factors so that the nation can have a competitive edge in the international climate change convention in the years to come.</P>

Transcriptional Profiling of ESTs from the Biocontrol Fungus <i>Chaetomium cupreum</i>

Zhang, Haiyan,Li, Min The Scientific World Journal 2012 The Scientific World Journal Vol.2012 No.-

<P>Comparative analysis was applied to two cDNA/ESTs libraries (C1 and C2) from <I>Chaetomium cupreum</I>. A total of 5538 ESTs were sequenced and assembled into 2162 unigenes including 585 contigs and 1577 singletons. BlastX analysis enabled the identification of 1211 unigenes with similarities to sequences in the public databases. MFS monosaccharide transporter was found as the gene expressed at the highest level in library C2, but no expression in C1. The majority of unigenes were library specific. Comparative analysis of the ESTs further revealed the difference of <I>C. cupreum</I> in gene expression and metabolic pathways between libraries. Two different sequences similar to the 48-KDa endochitinase and 46-KDa endochitinase were identified in libraries C1 and C2, respectively.</P>

Technological Progress in Generation of Induced Pluripotent Stem Cells for Clinical Applications

Oh, Seung-Ick,Lee, Chang Kyu,Cho, Kyung Jin,Lee, Kyung-Ok,Cho, Ssang-Goo,Hong, Sunghoi The Scientific World Journal 2012 The Scientific World Journal Vol.2012 No.-

<P>Reprogramming of somatic cells into induced pluripotent stem cells (iPSCs) is achieved by viral-mediated transduction of defined transcription factors. Generation of iPSCs is of great medical interest as they have the potential to be a source of patient-specific cells. For the eventual goal of clinical application, it is necessary to overcome the limitations of low reprogramming efficiency and chromosomal abnormalities due to viral DNA integration. In this paper, we summarize the current state of reprogramming technology for generation of iPSCs and also discuss potential approaches to the development of safe iPSCs for personalized cell-based replacement therapy.</P>

Altered Expression of Cellular Bcl-2 in the Progression of Hamster Cholangiocarcinogenesis

Jeon, Byung-suk,Yoon, Byung-IL The Scientific World Journal 2012 The Scientific World Journal Vol.2012 No.-

<P>Bcl-2 is an intracytoplasmic and membrane-associated apoptosis suppressor, and its overexpression is closely associated with survival of malignant tumors, in particular their aggressive behavior and poor prognosis. The role of Bcl-2 is, however, still controversial in cholangiocarcinogenesis because of the discrepancies in the expression of the protein. In the present study, alteration in the expression of Bcl-2 in cholangiocarcinogenesis was investigated by studying the immunoreactivities of this protein in normal, hyperplastic bile ducts with or without dysplastic changes, and neoplastic bile duct cells from a hamster cholangiocarcinoma (ChC) model. Cytoplasmic staining, which reflects high-Bcl-2 immunoreactivity, was negative to very weak in normal and hyperplastic bile ducts without dysplastic changes, while hyperplastic bile ducts with dysplasia indicated heterogeneously strong expression. On the other hand, most of the neoplastic cells of invasive cholangiocarcinomas were negative to weak as much as the level of normal bile ducts. The results suggest that the antiapoptotic factor Bcl-2 plays a limited role in the survival of highly proliferative, potentially dysplastic bile duct cells. However, the role of Bcl-2 in biliary cancer cells was not significant.</P>