• Title/Summary/Keyword: ${\Delta}h$

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Fixation and Histochemistry of Biological Tissues Using the Microwave Fixator Equipped with Infrared-Temperature Sensor (적외선 온도감응기를 장착한 마이크로파 고정기에 의한 생체조직 고정효과와 조직화학적 특성)

  • 신길상;민소연;김완종;손태호
    • The Korean Journal of Zoology
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    • v.38 no.3
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    • pp.417-425
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    • 1995
  • The present study was carried out to investigate the effect of microwave fixation in comparison with that of chemical fixation in preparing the microscopic samples. The microwave fixator was equipped with infrared-temperature sensor, and that was designed to compensate air temperature in the microwave fixator. In the microwave fixation, rat tongue was well preserved in terms of muscular fasciculus and pancreas stained by Feulgen reagents showed clear reaction products in the nucleus. Reaction products by PAS method in duodenal villi appeared specifically at the goblet cells. In electron microscopy, pancreatic cellular components such as secretory granules and collagen bundles were well preserved in both fixations. In aspect of histochemical reaction and electron microscopy, high quality was due to the protein content of microwave fixed specimen. The microwave fixation method saved total duration engaging microscopic preparation.

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Nonstoichiometry of the Ytterbium Oxide (산화 이테르븀의 비화학양론)

  • Chul Hyun Yo;Hyung Rak Kim;Kwon Sun Roh;Kyu Hong Kim;Eung Ju Oh
    • Journal of the Korean Chemical Society
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    • v.36 no.4
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    • pp.511-516
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    • 1992
  • The x-values of the nonstoichiometric compound YbO$_x$ have been measured in a temperature range of 600 to 1150$^{\circ}C$ under oxygen partial pressure of 1.00 ${\times}$ 10$^{-2}$ atm∼atmospheric air pressure. The values are varied between 1.55453 and 1.60794 in the conditions. The enthalpy of the formation for x' in YbO$_{1.5+x'}$(${\Delta}$H$_f$) was 1.55, 1.18, and 1.05 kJ/mol under the above conditions, respectively. The electrical conductivities of the oxides or ${\sigma}$ have been measured in the temperature range from 600 to 1100$^{\circ}C$ under oxygen partial pressure of 1.00 ${\times}$ 10$^{-5}$ ∼ 2.00 ${\times}$ 10$^{-1}$ atm. They varied from 10$^{-9}$ to 10$^{-5}$ ohm$^{-1}$ cm$^{-1}$ within the semiconductor range. The Arrhenius plots of the electrical conductivities show a linearity and the activation energy for the conduction was about 1.7eV. The oxygen partial pressure dependence of the conductivity or 1/n value increases with the pressure. The nonstoichiometric conduction mechanism of the oxide was discussed in terms of the x values, ${\sigma}$ values, and the thermodynamic data.

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Effect of Various Gluten-free Flours on Quality Characteristics and Antioxidant Activities of Cookies (전분의 종류를 달리하여 제조한 Gluten-free 쿠키의 품질특성 및 항산화 활성 비교)

  • Joung, Ki Youeng;Song, Ka-Young;O, Hyeonbin;Zhang, Yangyang;Shin, So Yeon;Kim, Young-Soon
    • Korean journal of food and cookery science
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    • v.33 no.2
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    • pp.127-136
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    • 2017
  • Purpose: This study examined the effect of different gluten-free flours on the properties of cookies. Methods: Each gluten-free cookie was made from wheat, brown rice, buckwheat, corn, sorghum, teff, or black rice. Results: Baking loss was highest on sorghum (18.85%) and the lowest on teff (12.73%). The spread factor was highest on brown rice (8.20) and lowest on corn (7.60). The density was similar in all samples (1 g/mL). pH was the highest on buckwheat (6.45) and lowest on wheat (5.96). While L-value, a-value and b-value were lowest on black rice, the ${\Delta}E-value$ was the highest on black rice (35.57). The hardness was highest on wheat (30.28 N) and lowest on teff (14.87 N). The polyphenol and flavonoid content was the highest on buckwheat ($25.97{\mu}g\;GAE/mg$) and the flavonoid content was the highest on black rice ($24.33{\mu}g\;QE/mg$). The DPPH IC50 value was highest on wheat ($352.41{\mu}g/mL$) and lowest on black rice ($33.59{\mu}g/mL$). The ABTS $IC_{50}$ value was highest on wheat ($349.30{\mu}g/mL$) and lowest on black rice ($57.72{\mu}g/mL$). The results of the sensory properties revealed color to be highest on corn (7.33). The top grain was similar in all the samples (5.43-6.57). Flavor was highest on black rice and teff (6.43-6.48). The softness was the highest on wheat, sorghum, teff, and black rice (6.48-7.05). Sweetness was highest on sorghum, teff, and black rice (6.19-6.71). The overall preference also was highest on sorghum, teff, and black rice (6.14-6.48). Conclusion: Gluten-free flours can improve the quality characteristics and antioxidant activities of cookies.

Physicochemical Properties of Crosslinked Potato Starch (가교결합 감자 전분의 이화학적 특성)

  • Kim, Hyang-Sook;Lee, Young-Eun
    • Korean Journal of Food Science and Technology
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    • v.28 no.3
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    • pp.573-579
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    • 1996
  • Crosslinked potato starches (XP), from 2,400 to 1,900 anhydroglucose units per crosslinked (AGU/CL), were prepared by reacting with epichlorohydrin. Some of the physicochemical properties of the XPs were then compared with those of native potato and cowpea starches. Crosslinking decreased moisture, protein and ash contents but had no effect on phosphorus content. Water binding capacities of the XPs increased as the degree of crosslinking increased, and that of the XP with 2,100 AGU/CL approached the value of cowpea starch. The absorption maxima of the starch-iodine complex shifted from 594 to 580 nm. Granule size increased slightly and surface appearance of the granule became rough when crosslinked. Both native and crosslinked potato starches showed B type X-ray diffraction pattern, and the relative crystallinity was not affected by crosslinking. Gelatinization temperature and the heat of gelatinization, measured by differential scanning calorimeter (DSC), did not change within the range of crosslinking tested. From X-ray and DSC data, it was concluded that the crosslinking ocurred in the amorphous region of the starch granule.

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Comparison of Opened Rates and Quality Characteristics of Frozen Baby-clam In-shell Tapes philippinarum Prepared by Different Processing Method (제조방법을 달리하여 제조한 껍질붙은 냉동바지락(Tapes philippinarum)의 껍질 개패율 및 품질특성 비교)

  • Park, Si-Young;Kang, Kyung-Hun;Lee, Jae-Dong;Yoon, Moon-Joo;Kang, Young-Mi;Seoung, Tae-Jong;Kweon, Su-Hyun;Choo, Yi-Kwon;Kim, Jeong-Gyun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.49 no.6
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    • pp.743-749
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    • 2016
  • We compared two different processing methods for preparing high quality frozen in-shell baby clam products. In the first method, sand and mud were removed from the clams, then they were vacuum packed in polyethylene film, boiled at $97^{\circ}C$ for 6 min, and snap frozen in a cold air blast freezer (sample 1). The second processing method was similar, except the boiling process was excluded (sample 2). Both frozen products were boiled for 4 min, and then shucked and minced. Various quality metrics, such as the opening rates of shells, chemical composition, pH, volatile basic nitrogen (VBN), salinity, thiobarbituric acid (TBA), amino-N, total amino acids and free amino acids were measured, and sensory evaluation was conducted. The opening rates of shells of sample 1 and sample 2 were 98.3% and 4.67%, respectively. The proximate composition of sample 1 and sample 2 was 75.2% and 78.7% moisture, 19.7% and 16.2% crude protein, 2.45 and 2.2% crude lipid, 2.8% and 2.1% ash, and 2.1% and 1.9% salinity, respectively. The L, a, b and ${\Delta}E$ values were similar: 48.6 and 49.2, 3.9 and 3.9, 15.7 and 15.5, and 50.7 and 50.1 for sample 1 and sample 2, respectively. The sensory evaluation score of sample 1 was higher than that of sample 2. Sample 1 was deemed to be superior to sample 2; therefore, we determined that the boiling process is needed for manufacturing high-quality frozen clam products.

Study on the Quality Characteristics and Retarding Retrogradation of Pound Cakes containing Teff (Eragrostis tef) Flour (테프(Eragrostis tef) 분말을 첨가한 파운드케이크의 품질 특성 및 노화 억제 분석)

  • Joung, Ki Youeng;Song, Ka-Young;O, Hyeonbin;Zhang, Yangyang;Shin, So Yeon;Kim, Young-Soon
    • Journal of the East Asian Society of Dietary Life
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    • v.27 no.1
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    • pp.41-49
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    • 2017
  • This study investigated the effects of teff flour on the properties of pound cakes. Five types of pound cakes were made by addition of 0% (Control), 5% (TF5), 10% (TF10), 15% (TF15), and 20% (TF20) of teff flour based on wheat flour. Specific gravity of pound cake batter showed no significant differences among samples as 0.54 (p<0.05). Baking loss was the highest in the control at 5.92% and the lowest in TF20 at 5.27%. Batter yield was the highest in TF20 at 94.73% and the lowest in control at 94.08%. Moisture content was the highest in TF20 at 23.68% and the lowest in control at 21.32%. pH showed no significant differences among samples at 7.61~7.65 (p<0.05). a-values of crumb significantly increased while L-values and b-values significantly decreased with added teff flour amounts. (p<0.05). ${\Delta}E$ values significantly increased with teff flour at 34.32~49.24 (p<0.05). Hardness was lowest in TF20 at $180.60g/cm^2$. Springiness was the lowest in TF20 at 85.37%. Cohesiveness showed no significant differences among samples (p<0.05). Chewiness was the lowest in TF20 at 172.17 g. Hardness more rapidly increased in control at $273.13{\sim}26,123.33g/cm^2$ than that of pound cakes with teff flour. Avrami exponent (n) was the highest in the control at 3.5987 and the lowest in TF20 at 1.2144. In sensory evaluation, flavor of TF20 was higher than that of the control at 4.43. Overall acceptability had a higher score in TF20 than in the control. It is considered that addition of 20% teff flour can improve the quality characteristics and retard retrogradation of pound cake.

Design and Fabrication of K Band Push-Push Dielectric Resonator Oscillator (K 대역 Push-Push 유전체 공진기 발진기 설계 및 제작)

  • 정재권;박승욱;김인석
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.7
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    • pp.613-624
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    • 2002
  • Electrical characteristics of two types of 20 GHz Push-Push GaAs MESFET dielectric resonator oscillators having Wilkinson and T-junction power combiners for the output stage have been investigated and compared. So we have explained that the output power and phase noise properties of the Push-push FET DRO are depending on return loss and isolation characteristics of power combiner at the fundamental and the second harmonic frequencies. A Push-push oscillator for suppressing the fundamental frequency of 10 GHz and enhancing the second harmonic of 20 GHz has been designed and fabricated in microstrip configuration on 20 mil thick RT-Duroid($\varepsilon$$_{r}$ = 2.52) Teflon substrate. Return loss and isolation characteristics of T-junction and Wilkinson have been measured at the fundamental frequency of 10.2 GHz and the second harmonic frequency of 20.5 GHz. At the fundamental frequency, -12 dB return loss and -3.7 dB isolation have been measured for the T-junction power combiner, and -14 dB return loss and -11 dB isolation fur the Wilkinson power combiner. At the second harmonic frequency, -10 dB return loss and -7.5 dB isolation have been obtained for the T-junction power combiner, and -23 dB return loss and -22 dB isolation for the Wilkinson power combiner. As a result, we have confirmed that the oscillator based on the Wilkinson power combiner with better retrun loss and isolation characteristics produces more output power and better phase noise characteristics..

Improvement of Microwave Heating Properties of Frozen Starch by Spray of Surface Materials (Maltodextrin류의 표면도포에 의한 냉동전분의 Microwave 가열특성 개선)

  • Kim, Eun-Mi;Han, Hye-Kyung;Kim, In-Ho
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.7
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    • pp.1035-1040
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    • 2005
  • This study was conducted to investigate the surface spraying effect of materials on the rheological properties of frozen starch with microwave heating. Microwave helps reduce cooking time by high temperature, but swiftly snatches moisture from foods such as frozen starches (buns and noodles etc) and makes surface of foods harder. Four types of maltodextrin materials have been prepared for different concentration solutions and sprayed on surface doughs of sheet type. Sprayed dough samples were Quickly frozen at $-70^{\circ}C$ and wrapped with polypropylene film. All the treated samples were kept at 0, -20 and $-50^{\circ}C$, and then taken out periodically for measurement of the quality during storage. The quality attributes evaluated after heating with microwave energy include sensory quality retrogradation, texture, surface color and microstructure. The quality of frozen starches deteriorated with long term storage even at low temperatures of -20 and $-50^{\circ}C$, and the spray materials were found to improve the textural and physical properties of frozen starches in the microwave heating. Particularly, maltodextrin with D.E value of $9\~12$ had the most desirable effects of quality improvement.

Characteristics of Bearing Capacity under Square Footing on Two-layered Sand (2개층 사질토지반에서 정방형 기초의 지지력 특성)

  • 김병탁;김영수;이종현
    • Journal of the Korean Geotechnical Society
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    • v.17 no.4
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    • pp.289-299
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    • 2001
  • 본 연구는 균질 및 2개층 비균질지반에서 사질토지반 상에 놓인 정방형 기초의 극한지지력과 침하에 대하여 고찰하였다. 본 연구는 얕은기초의 거동에 대한 정방형 기초의 크기, 지반 상대밀도, 기초 폭에 대한 상부층의 두께 비(H/B), 상부층 아래 경계면의 경사($\theta$) 그리고 지반강성비의 영향을 규명하기 위하여 모형실험을 수행하였다. 동일 상대밀도에서 지지력 계수($N_{{\gamma}}$)는 일정하지 않으며 기초 폭에 직접적으로 관련되며 지지력계수는 기초 폭이 증가함에 따라 감소하였다. 기초크기의 영향과 구속압력의 영향을 고려하는 Ueno 방법에 의한 극한지지력의 예측값은 고전적인 지지력 산정식보다 더 잘 일치하며 그 값은 실험값의 65% 이상으로 나타났다. $\theta$=$0^{\circ}$인 2개층 지반의 결과에 근거하여, 극한지지력에 대한 하부층 지반의 영향을 무시할 수 있는 한계 상부층 두께는 기초 폭의 2배로 결정되었다. 그러나, 73%의 상부층 상대밀도인 경우는 침하비($\delta$B) 0.05 이하에서만 이 결과가 유효하였다. 경계면이 경사진 2개층 지반의 결과에 근거하여, 상부층의 상대밀도가 느슨할수록 그리고 상부층의 두께가 클수록 극한지지력에 대한 경계면 경사의 영향은 크지 않는 것으로 나타났다. 경계면의 경사가 증가함에 따른 극한침하량의 변화는 경계면이 수평인 경우($\theta$=$0^{\circ}$)를 기준으로 0.82~1.2(상부층 $D_{r}$=73%인 경우) 그리고 0.9~1.07(상부층 $D_{r}$=50%인 경우) 정도로 나타났다.Markup Language 문서로부터 무선 마크업 언어 문서로 자동 변환된 텍스트를 인코딩하는 경우와 같이 특정한 응용 분야에서는 일반 문자열에 대한 확장 인코딩 기법을 적용할 필요가 있을 수 있다.mical etch-stop method for the etching of Si in TMAH:IPA;pyrazine solutions provides a powerful and versatile alternative process for fabricating high-yield Si micro-membranes. the RSC circle, but also to the logistics system in the SLC circle. Thus, the RSLC model can maximize combat synergy effects by integrating the RSC and the SLC. With a similar logic, this paper develops "A Revised System of Systems with Logistics (RSSL)" which combines "A New system of Systems" and logistics. These tow models proposed here help explain several issues such as logistics environment in future warfare, MOE(Measure of Effectiveness( on logistics performance, and COA(Course of Actions) for decreasing mass and increasing velocity. In particular, velocity in logistics is emphasized.

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Synthesis and Characterization of Vanadium(III) Complexes with N-Donating Ligands (질소 주개 리간드를 갖는 바나듐(III) 착물의 합성과 특성)

  • Sang-Oh Oh;Eun-Young Lyou
    • Journal of the Korean Chemical Society
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    • v.36 no.6
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    • pp.872-878
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    • 1992
  • Some vanadium(III) complexes have been prepared by the reaction of VCl3${\cdot}$3MeCN with ligands and characterized by elemental analysis, 1H-NMR, infrared and UV-Visible spectroscopy. 3,5-lutidine(lutd), 8-hydroxyquinoline(oxine), 1,2-phenylenediamine(phda), ethylenediamine(en), and sym-diphenylethylenediamine(dpen) were chosen as coordinating ligands. ${\nu}$(V-Cl) of lutidine complex occurs at 418 $cm^{-1}$ and the other complexes (oxine, phda, en, dpen) occur at 337∼347 $cm^{-1}$. The value of ${\nu}$(V-Cl) indicates that the former complex has trigonal bipyramid structure and the latter complexes have octahedral structure. The ${\nu}$(C${\equiv}$N) of acetonitrile in oxine and phda complexes are characteristically shifted to about 70 $cm^{-1}$ higher frequency compared with that of free ligand (2260 $cm^{-1}$). The ${\delta}$(C${\equiv}$N) is also shifted to about 60 $cm^{-1}$ higher frequency compared with that of free ligand (377 $cm^{-1}$). Finally each vanadium(III) complex showed the following formulation; [$VCl_3(lutd)_2$], [$VCl(oxine)_2$MeCN]$Cl_2$, [$VCl(phda)_2$MeCN]$Cl_2$, [$VCl_2(en)_2$]Cl, [$VCl_2(dpen)_2$]Cl.

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