Synthesis and Characteristics of Carbon Nanofibers/Silicon Composites and Application to Anode Materials of Li Secondary Batteries

Among the various synthesizing technologies of carbon nanofibers (CNFs), chemical vapor deposition (CVD) technology, which uses hydrocarbon gas or carbon monoxide as a carbon source gas and pyrolyzes it to grow CNFs on transition metal catalysts, such as Ni, Fe, and Co, has been regarded as the most inexpensive and convenient method to produce CNFs for industrial use. Experimental variables for CVD are source gas, catalyst layers, temperature, and reaction time. Since the particle size of metal catalysts has an influence on the diameter of CNFs, it is possible to control the diameter of CNFs by varying particle sizes of the metal. As such, it is possible to synthesize CNFs selectively through the selective deposition of catalyst metals. In this study, CNFs were grown by CVD on C-fiber textiles, which had catalysts deposited via electrophoretic deposition. The CNFs were coated with a silica layer via hydrolysis of TEOS (tetraethyl orthosilicate), and the CNFs were oxidized by nitric acid. Due to oxidation, a hydroxyl group was created on the CNFs, which was then able to be used as an activation site for the SiO2. CNFs and the CNFs/SiO2 composite can be used in various applications, such as a composite material, electromagnetic wave shielding material, ultrathin display devices, carbon semiconductors, and anode materials of Li secondary batteries. In particular, there is an increasing demand for lightweight, small-scale, and high-capacity batteries for portable electronic devices, such as laptop computers or smart phones, along with the escalating concern of fossil energy depletion. Accordingly, CNFs and CNFs/SiO2 composites are receiving attention for their use as anode materials of Li secondary batteries, which are eco-friendly, lightweight, and high capacity. Therefore, the physicochemical properties and electrochemical performance data of synthesized CNFs and CNFs/SiO2 composite are described in this chapter

Analysis of Initial Baseline Clinical Parameters and Treatment Strategy Associated with Medication Failure in the Treatment of Benign Prostatic Hyperplasia in Korea

Purpose To analyze the baseline clinical factors and medication treatment strategy used in cases with medication treatment failure of benign prostatic hyperplasia (BPH). Methods From January 2006 to December 2009, 677 BPH patients with at least 3 months of treatment with medication were enrolled. We analyzed clinical factors by medication failure (n=161) versus maintenance (n=516), by prostate size (less than 30 g, n=231; 30 to 50 g, n=244; greater than 50 g, n=202), and by prostate-specific antigen (PSA) levels (less than 1.4 ng/mL, n=324; more than 1.4 ng/mL, n=353). Results Age, combination medication rate, PSA, and prostate volume were statistically different between the medication treatment failure and maintenance groups. By prostate size, the PSA and medication failure rates were relatively higher and the medication period was shorter in patients with a prostate size of more than 30 g. The combination medication rate was higher in patients with a prostate size of more than 50 g. The medication failure rate and prostate volume were higher in patients with a PSA level of more than 1.4 ng/mL. However, the combination treatment rate was not significantly different in patients with a PSA level lower than 1.4 ng/mL. Suggestive cutoffs for combination medication are a prostate volume of 34 g and PSA level of 1.9 ng/mL. Conclusions The clinical factors associated with medication failure were age, treatment type, and prostate volume. Combination therapy should be considered more in Korea in patients with a PSA level higher than 1.4 ng/mL and a prostate volume of between 30 and 50 g to prevent medication failure

Compressive Behavior and Mechanical Characteristics and Their Application to Stress-Strain Relationship of Steel Fiber-Reinforced Reactive Powder Concrete

Although mechanical properties of concrete under uniaxial compression are important to design concrete structure, current design codes or other empirical equations have clear limitation on the prediction of mechanical properties. Various types of fiber-reinforced reactive powder concrete matrix were tested for making more usable and accurate estimation equations for mechanical properties for ultra high strength concrete. Investigated matrix has compressive strength ranged from 30 MPa to 200 MPa. Ultra high strength concrete was made by means of reactive powder concrete. Preventing brittle failure of this type of matrix, steel fibers were used. The volume fraction of steel fiber ranged from 0 to 2%. From the test results, steel fibers significantly increase the ductility, strength and stiffness of ultra high strength matrix. They are quantified with previously conducted researches about material properties of concrete under uniaxial loading. Applicability of estimation equations for mechanical properties of concrete was evaluated with test results of this study. From the evaluation, regression analysis was carried out, and new estimation equations were proposed. And these proposed equations were applied into stress-strain relation which was developed by previous research. Ascending part, which was affected by proposed equations of this study directly, well fitted into experimental results

The effect of fermented buckwheat on producing L-carnitine enriched oyster mushroom

L-carnitine is biological compound which serves intake of long chain fatty acids into mitochondria. In market, L-carnitine is considered as nutritious supplements for weight-loss. L-carnitine is synthesized in human organ, but most of L-carnitine which human intakes are originated from meat based foods. Oyster mushroom (Pleurotus ostreatus), the second popular edible mushroom in the world, is the main source of L-carnitine after meat and pork. Recently, there were many efforts to study designer foods of which functional ingredients were increased. However most of studies were focused on dairy products. In this study, the fermented buckwheat by Rhizopus oligosporus that contained high L-carnitine contents were used to cultivate oyster mushroom. L-carnitine contents in oyster mushroom were quantified by LC-ESI-MS. Mushroom grown on buckwheat medium had 3.17 to 23.88% higher L-carnitine concentration than normal medium. The mushroom size was increased when 20% (w/w) of buckwheat was added to basal medium. The lightness of mushroom pileus (L*) significantly increased among all the treatments. These results demonstrate that buckwheat and fermented buckwheat is novel substrates to produce L-carnitine enriched functional mushroom.OAIID:RECH_ACHV_DSTSH_NO:A201702463RECH_ACHV_FG:RR00200003ADJUST_YN:EMP_ID:A079459CITE_RATE:FILENAME:태경.pdfDEPT_NM:국제농업기술학과EMAIL:[email protected]_YN:FILEURL:https://srnd.snu.ac.kr/eXrepEIR/fws/file/34dfad8a-5bc9-41cd-8160-c7846937fa22/linkCONFIRM:

ArmA and RmtB Were the Predominant 16S RMTase Genes Responsible for Aminoglycoside-resistant Isolates in Korea

Pathogenic gram-negatives that produce 16S ribosomal RNA methyltransferases (16S RMTases) have already been distributed all over the world. To investigate the predominance of aminoglycoside resistance associated with 16S RMTases in Korea, we collected a total of 222 amikacin resistant Gram-negative clinical isolates from patient specimens between 1999 and 2015 from three hospital banks across Korea. ArmA and nntB were the predominant 16S RMTase genes responsible for aminoglycoside-resistant isolates circulating in Korean community settings although only one rmtA-producing isolate was detected in 2006.1

Concurrence of Ring 21 and Trisomy 21 in Children of Normal Parents

We present a case of two siblings with different chromosome 21 abnormalities that are both de novo [r(21)/i(21p13) mosaicism and rob(14;21)]. Molecular studies using polymorphic markers have shown that these two aberrations had a common maternal origin. However, the parents were cytogenetically and phenotypically normal. This unusual association has not been reported and is considered to be a unique case that should be addressed

A Sporadic Outbreak of Human Brucellosis in Korea

Eleven cases of human brucellosis occurred among livestock workers and a veterinarian who lived and worked in a rural area around Jeongeup City, Jeollabuk-Do, Korea from February 2003 to August 2003. Eight of the patients had taken care of Korean native cattle that were infected with bovine brucellosis and had already been slaughtered. Two of the patients had taken care of dairy cattle, and one case was a veterinarian who acquired the disease through an accidental contact with infected cattle while assisting in calf delivery. Eleven cases were identified by serologic work ups and four cases were identified via positive blood cultures. This study shows that the Republic of Korea is no longer free of human brucellosis, Brucella abortus biotype 1. We reviewed the patients' characteristics and serologic data during the one-year follow up period, and we also discuss on the efficacy and side effects of the rifampin and doxycyline regimen used for the treatment of human brucellosis