• Journal of the Korea Concrete Institute
• /
• v.21 no.4
• /
• pp.531-537
• /
• 2009

In this study alkali reactivity of crushed stone was conducted according to the ASTM C 227 that is traditional mortar bar test, and C 1260 that is accelerated mortar bar test method. The morphology and chemical composition of products formed in mortar bar, 3 years after the mortar bar tests had been performed, were examined using scanning electron microscopy (SEM) with secondary electron imaging (SEI) and electron probe microanalysis (EPMA) with backscattered electron imaging (BSEI). The crushed stone used in this study was not identified as being reactive by ASTM C 227. However, mortar bars exceeded the limit for deleterious expansion in accelerated mortar bar test used KOH solution. The result of SEM (SEI) analysis, after the ASTM C 227 mortar bar test, confirmed that there were no reactive products and evidence of reaction between aggregate particles and cement paste. However, mortar bars exposed to alkali solution (KOH) indicated that crystallized products having rosette morphology were observed in the interior wall of pores. EPMA results of mortar bar by ASTM C 227 indicated that white dots were observed on the surface of particles and these products were identified as Al-ASR gels. It can be considered that the mortar bar by ASTM C 227 started to appear sign of alkali-silica reaction in normal condition. EPMA results of the mortar bar by ASTM C 1260 showed the gel accumulated in the pores and diffused in to the cement matrix through cracks, and gel in the pores were found to be richer in calcium compared to gel in cracks within aggregate particles. In this experimental study, damages to mortar bars due to alkali-silica reaction (ASR) were observed. Due to the increasing needs of crushed stones, it is considered that specifications and guidelines to prevent ASR in new concrete should be developed.

• Korean Chemical Engineering Research
• /
• v.50 no.6
• /
• pp.1034-1042
• /
• 2012

This study was performed by using an LFR (laminar flow reactor), which can be used to carry out different types of research on coal. In this study, an LFR was used to analyze coal flames, tar and soot yields, and structures of chars for two coals depending on their volatile content. The results show that the volatile content and oxygen concentration have a significant effect on the length and width of the soot cloud and that the length and width of the cloud under combustion conditions are less than those under a pyrolysis atmosphere. At sampling heights until 50 mm, the tar and soot yields of Berau (sub-bituminous) coal, which contains a large amount of volatile matter, are less than those of Glencore A.P. (bituminous) coal because tar is oxidized by the intrinsic oxygen component of coal and by radicals such as OH-. On the other hand, at sampling heights above 50 mm, the tar and soot yields of Berau coal are higher than those of Glencore A.P. coal by reacted residual volatile matter, tar and light gas in char and flame. With above results, it is confirmed that the volatile matter content and the intrinsic oxygen component in a coal are significant parameters for length and width of the soot cloud and yields of the soot. In addition, the B.E.T. results and the images of samples (SEM) obtained from the particle separation system of the sampling probe support the above results pertaining to the yields; the results also confirm the pore development on the char surface caused by devolatilization.

• Tuberculosis and Respiratory Diseases
• /
• v.66 no.6
• /
• pp.444-450
• /
• 2009

Background: Biomarkers for cancer have several potential clinical uses, including the following: early cancer detection, monitoring for recurrence prognostication, and risk stratification. However, no biomarker has been shown to have adequate sensitivity and specificity. Many investigators have tried to validate biomarkers for the early detection and recurrence of lung cancer. To evaluate plasma G-CSF as such a biomarker, protein levels were measured and were found to correlate with the clinicopathological features of primary lung tumors. Methods: Between December 2006 and May 2008, 100 patients with histologically-validated primary lung cancer were enrolled into this study. To serve as controls, 127 healthy volunteers were enrolled into this study. Plasma G-CSF levels were measured in lung cancer patients using the sandwich ELISA system (R & D inc.) prior to treatment. Results: The mean plasma G-CSF levels were 12.2$\pm$0.3 pg/mL and 46.0$\pm$3.8 pg/mL (mean$\pm$SE) in the normal and in the cancer groups, respectively. In addition, plasma G-CSF levels were higher in patients with early lung cancer than in healthy volunteers (p<.001). Plasma G-CSF levels were higher in patients who were under 65 years old or smokers. Within the cancer group, plasma G-CSF levels were higher in patients with non small cell lung cancer than in patients with small cell lung cancer (p<.05). Overall, plasma G-CSF levels were shown to increase dependent upon the type of lung cancer diagnsosed. In the order from highest to lowest, the levels of plasma G-CSF tended to decrease in the following order: large cell carcinoma, squamous cell carcinoma, adenocarcinoma, and bronchioloalveolar carcinoma. Plasma G-CSF levels tended to be higher in patients with advanced TNM stage than in localized TNM stage (I, II

• Journal of Bio-Environment Control
• /
• v.25 no.4
• /
• pp.334-342
• /
• 2016

In order to evaluate the modified installation methods of roof ventilation devices, derived from the previous experiment ('investigation into the optimum capacity of roof ventilation devices and their deployment'), the conventional and modified (improved) roof ventilation systems were installed in the single-span plastic greenhouse for growing oriental melons. The roof vents ($60{\varphi}$) and roof fans (maximum air capacity of $38m^3/min$) were installed in the spacing of 15m (FT, modified 'side vent+roof fan' ventilation) and 6m (TT, modified 'side vent+roof vent' ventilation) respectively on the roof of greenhouses for the modified roof ventilation treatments, and 20m (FC, conventional 'side vent+roof fan' ventilation) and 8m (TC, conventional 'side vent+roof vent' ventilation) for the conventional ones. The stem diameter, leaf blade lengh, petiole length, and leaf width were lower in the FT and TT treatments than those in the conventional treatments, FC and TC. Although the fruit weight and total yields were slightly lower in the FT and TT treatments, the marketable fruit ratio (%) were higher, as a result of increased fruiting ratio (%) in these treatments, than those of FC and TC. The marketable yields (kg/10a) in the FT and TT treatments were 8,391 kg/10a and 7,283 kg/10a, which were respectively 661 kg/10a and 487 kg/10a higher than those in the treatments of FC and TC. The modified installation methods of roof fan resulted in production of more female flowers and lower fruit drop ratio (%) compared to conventional meathods. In the treatment of the conventional ventilation with roof vent, the fruit weight, fruit length & width, and flesh thickness were higher than in other treatments, but there were no significant differences in the fruit width and flesh thickness among the treatments.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.46 no.3
• /
• pp.75-85
• /
• 2009

This work proposes a 13b 100MS/s 0.13um CMOS ADC for 3G communication systems such as two-carrier W-CDMA applications simultaneously requiring high resolution, low power, and small size at high speed. The proposed ADC employs a four-step pipeline architecture to optimize power consumption and chip area at the target resolution and sampling rate. Area-efficient high-speed high-resolution gate-bootstrapping circuits are implemented at the sampling switches of the input SHA to maintain signal linearity over the Nyquist rate even at a 1.0V supply operation. The cascode compensation technique on a low-impedance path implemented in the two-stage amplifiers of the SHA and MDAC simultaneously achieves the required operation speed and phase margin with more reduced power consumption than the Miller compensation technique. Low-glitch dynamic latches in sub-ranging flash ADCs reduce kickback-noise referred to the differential input stage of the comparator by isolating the input stage from output nodes to improve system accuracy. The proposed low-noise current and voltage references based on triple negative T.C. circuits are employed on chip with optional off-chip reference voltages. The prototype ADC in a 0.13um 1P8M CMOS technology demonstrates the measured DNL and INL within 0.70LSB and 1.79LSB, respectively. The ADC shows a maximum SNDR of 64.5dB and a maximum SFDR of 78.0dB at 100MS/s, respectively. The ABC with an active die area of $1.22mm^2$ consumes 42.0mW at 100MS/s and a 1.2V supply, corresponding to a FOM of 0.31pJ/conv-step.

• Korean Journal of Food Science and Technology
• /
• v.49 no.3
• /
• pp.304-310
• /
• 2017

The aim of this study was to compare the physicochemical properties of domestic and imported commercial plain wheat flour and dough. Four types of domestic wheat flour (DW; DW1-4) were compared to four types of imported wheat flour (IW; IW1-4). DWs exhibited lower moisture content, lightness (L), and whiteness, and higher protein content, redness (a), and yellowness (b), than those exhibited by IWs. Solvent retention capacity of DWs and IWs was similar; however, DWs showed higher gluten performance index. Pasting properties, analyzed by rapid visco analyzer (RVA), were similar for DW1, DW2, and IWs; however, DW3 and DW4 showed different RVA patterns. Considering that DW3 and DW4 were organic wheat flour, possible incorporation of damaged kernel might increase amylase activities resulting in decreased peak viscosity. Dough resistance (108.4-159.9 g) and extensibility (11.8-16.7 mm) of IWs were higher than those of DWs (78.0-118.7 g, 8.7-12.5 mm, respectively).

• Journal of Embryo Transfer
• /
• v.28 no.3
• /
• pp.177-184
• /
• 2013

The objective of this study was to analyze the accuracy of estrus detection of heat detector and analysis of estrus behavior (mounting and mounted), and the evaluation of conditions required for improving reproductive efficiency in Holstein dairy cows fitted with a estrous detector. The heat detection system consists of estrous detector based on wireless sensor and an electric bulletin board displayed estrus behavior data. When cow mounting other cows, the accuracy of estrus behavior displayed an electric bulletin board were 87.5% (mounting other cows only), 100% (mounting other cows but not standing), 80.0% (mounting other cows with standing for 1~4 seconds), 90.0% (mounting other cows but not standing for 1~4 seconds), 80% (mounting other cows with standing for more than 5 seconds) and 90.0% (mounting other cows but not standing for more than 5 seconds). When cow mounted other cows, the accuracy of estrus behavior displayed an electric bulletin board were 100% (mounted other cows but not standing), 100% (mounted other cows with standing for 1~4 seconds), 100% (mounted other cows but not standing for 1~4 seconds) and 100% (mounted other cows with standing for more than 5 seconds). Circadian distribution of first observed in estrus were 59.1% (am 8~pm 6) and 40.9% (pm 6~am 8). Distribution for the number of estrus behavior were 40.9% (less than 3 times), 36.4% (4~6 times) and 22.7% (more than 4 times). The conception rates relative to interval from first estrus behavior to insemination for estrus periods were 23.1% (less than 11 hours) and 55.6% (12~20 hours).

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.40 no.1
• /
• pp.29-36
• /
• 2004

This study deals with an analysis on the sinking resistance for the model purse seine, in the case of different netting material and sinkers. The experiment was carried out using rune simplified model seines of knotless nettings. Dimension of model seines 420cm for corkline and 85cm for seine depth, three groups of models rigged 25, 45 and 60g with the same weighted sinkers in water were used. These were named PP-25, PA-25, PES-25, PP-45, PA-45, PES-45, PP-60, PA-60 and PES-60 seine. The densitie($\rho$) of netting materials were 0.91g/cm$cm^3$, 1.14g/cm$cm^3$ and 1.38g/cm$m^3$. Experiments carried out in the observation channel in a flume tank under still water conditions. Sinking motion was recorded by the one set of TV-camera for VTR, and reading coordinate carried out by the video digitization system. Differential equations were derived from the conservation of momenta of the model purse seines and used to determine the sinking speeds of the depths of leadline and the other portions of the seines. An analysis carried out by simultaneous differential equations for numerical method by sub-routine Runge-Kutta-Gill The results obtained were as follows : 1. Average sinking speed of leadline for the model seines rigged 60g with the same weighted sinkers in water was fastest for 12.2cm/sec of PES seine, followed by 11.4cm/sec of PA and 10.7cm/sec of PP seines. 2. The coefficient of resistance for netting of seine was estimated to be $K_D=0.09(\frac{\rho}{\rho_w})^4$ 3. The coefficient of resistance for netting bundle of seine was estimated to be $C_R=0.91(\frac{\rho}{\rho_w})$ 4. In all seines, the calculated depths of leadline closely agreed with the measured ones, each 25g, 45g, 60g of weighted sinkers were put into formulas meas.=1.04cal., meas.=0.99cal. and meas.=0.98 cal.

• Journal of Korean Home Economics Education Association
• /
• v.22 no.4
• /
• pp.109-138
• /
• 2010

This study examined how practical reasoning process is reflected in the 2007 revised home economics textbook of the 7th grade that is being used in schools since 2010. For a textbook analysis of the components of practical reasoning process, 12 published textbooks were all analyzed, and analysis areas were decided by reconstructing the textbook system into introduction, body contents, learning activities, evaluation. Analysis criteria were extracted from the previous literatures. Practical reasoning process was classified into Valued Ends, Context and Background, Alternatives and Means, on sequence, and Action and Reflection. As a result of analyzing categories and problems that practical reasoning process is reflected in the textbook, firstly, here was a category, which Valued Ends was absent in the practical reasoning process. In the relevant category, general problem solving progress and practical reasoning process could not be differentiated, and activity was developed with 'strategies for solution' as objective. Second, there was a category that the practical reasoning process was reflected in body contents. In this category, knowledge, concept, principle, and theory were insufficiently dealt with. Third, there was a category that reflected components of practical reasoning process but was covered with general problem solving process. Fourth, there was a category that described theme of sub-unit and body contents from the different curriculum perspectives. A curriculum perspective works as the foundation of preparing class contents or consistency of methods when developing lessons. Therefore, confusion might occur when a teacher plans a class with this kind of textbook. Fifth, a category that suggested partial components of practical reasoning process was shown the most and this category is difficult to maximize effects of practical reasoning process.

• Clinical and Experimental Pediatrics
• /
• v.46 no.1
• /
• pp.56-66
• /
• 2003

Purpose : Human umbilical vein endothelial cells(HUVECs) play an important role in regulating blood flow by releasing vasoactive substances. It has been reported that endothelial impairment and dysfunction might be a primary cause of placental vascular disease, which is manifested clinically as preeclampsia in mother and intrauterine growth restriction in fetus. Furthermore, the frequency of apoptotic changes is increased in umbilical and placental tissues from growth-restricted pregnancies. However, the various mechanisms of umbilical endothelial cell apoptosis have not been broadly proposed. We investigate the effects of amiloride derivatives on apoptotic death of HUVECs and identify their ionic mechanism. Methods : HUVECs were purchased from Clonetics, and cultured on endothelial cell growth medium. MTT assay and flow cytometry were used for assessing cytotoxic effect and confirming the apoptosis. Changes in intracellular ion concentrations were measured with specific fluorescent dyes and fluorescence imaging analysis system. Results : Amiloride derivatives elicited cytotoxic effects on HUVECs with dose-dependent manners and the rank order of potency is HMA($IC_{50}\;11.2{\mu}M$), MIA>EIPA>>amiloride. HMA-induced cytotoxicity is dependent on extra- and intracellular pH, that is, increase extra- and intracellular pH augmented the cytotoxic effects of HMA. HMA dose-dependently reduced intracellular major ions, such as $K^+$ and $Cl^-$. Interestingly, the depletion of intracellular ions induced by HMA was also significantly enhanced at alkaline extracellular pH. Conclusion : Amiloride derivatives induce apoptosis of HUVECs with dose and pH dependent manners. They reduce intracellular $K^+$ and $Cl^-$ concentration, which is also extracellular pH dependent.