• Title/Summary/Keyword: nRP

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Separation of liquiritin, glycyrrhizic acid and glabridin from licorice by RP-HPLC (RP-HPLC를 이용한 감초에서 liquiritin, glycyrrhizic acid, glabridin의 분리)

  • Tian, Minglei;Yan, Hongyuan;Row, Kyung Ho
    • Analytical Science and Technology
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    • v.21 no.2
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    • pp.102-108
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    • 2008
  • Reversed-phase high performance liquid chromatography (RP-HPLC) was used for the simultaneous determination of liquiritin (LQ), glycyrrhizic acid (GA) and glabridin from licorice. An optimized run condition was selected with a binary gradient elution of methanol-water which ramped 35/65 to 80/20 (vol. %) in 0.0-8.0 min and a flow rate of 1.0 mL/min. A good linearity was obtained between 0.2 mg/mL and 1.0 mg/mL for LQ and GA, and 0.01 mg/mL-0.2 mg/mL for glabridin with the relative standard deviations less than 0.90% (n=5). The developed method was successfully applied to determination of the three components from licorice samples. The mean recoveries of three components are 80.79% for liquiritin, 89.71% for glycyrrhizic acid and 72.50% for glabridin.

Comparison of the ability of Reciproc and Reciproc Blue instruments to reach the full working length with or without glide path preparation

  • Adiguzel, Mehmet;Tufenkci, Pelin
    • Restorative Dentistry and Endodontics
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    • v.43 no.4
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    • pp.41.1-41.7
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    • 2018
  • Objectives: The purpose of the present study was to compare the mean preparation times and frequency with which Reciproc and Reciproc Blue instruments reached the full working length in mandibular molars, with or without glide path preparation. Materials and Methods: Previously untreated mesiobuccal and mesiolingual canals with completely formed apices were randomly divided into 6 groups (n = 50) depending on the usage of Reciproc (RC; VDW), Reciproc Blue (RC Blue; VDW), C-Pilot (CP; VDW), and R-Pilot (RP; VDW) files: RC, RC Blue, RC + C-Pilot (RC-CP), RC-Blue + C-Pilot (RC Blue-CP), RC+R-Pilot (RC-RP), and RC Blue + R-Pilot (RC Blue-RP). A glide path was prepared using the hand-operated C-Pilot or the machine-operated R-Pilot instruments, respectively. The ${\chi}^2$ test, analysis of variance, and the Tukey post hoc test were used for statistical comparisons. Results: No statistically significant differences were observed in the distribution of the frequency of reaching the full working length in the RC (94%), RC Blue (88%), RC-CP (94%), RC Blue-CP (90%), RC-RP (96%), and RC Blue-RP (92%) groups (p > 0.05). Conclusions: Preparation of a glide path did not have a significant effect on reaching the full working length using these systems.

Influence of Adding Recovered Protein from Processing Wastewater on the Quality of Mechanically Separated Chicken Meat Surimi Like-Material

  • Cortez-Vega, William Renzo;Fonseca, Gustavo Graciano;Bagatini, Daniela Cardozo;Prentice, Carlos
    • Food Science of Animal Resources
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    • v.37 no.2
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    • pp.162-167
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    • 2017
  • Functional and nutritional soluble proteins can be recovered from surimi (and surimi-like material) processing wastewater, reducing environmental problems and the cost of an irresponsible waste disposal. Recovered proteins may be added back at a low percentage to surimi products. The aim of this work was to evaluate the effect of the addition of soluble recovered proteins (RP), obtained from mechanically separated chicken meat surimi-like material (MSCM-SLM) processing wastewater by acidic pH-shifting, on the composition and texture of RP-MSCM-SLM, with RP contents of 0, 10, 20 and 30% (w/w) in the mixture. For that, proximate composition and gel properties were evaluated. The fat content of the MSCM-SLM was significantly reduced to 11.98% and protein increased to 83.64% (dry basis) after three washing cycles. The addition of 30% RP in the MSCM-SLM significantly augmented the protein content to 93.45% and reduced fat content from to 2.78%. On the other hand, the addition of RP was responsible for a drastic decrease in texture parameters, reaching 252.36 g, 185.23 g.cm, and 6.97 N for breaking force, gel strength and cutting strength, respectively, when 30% of RP was included in the MSCM-SLM. It was concluded that the obtained intermediary product (RP-MSCM-SLM) is a good option to applications in processed meat products where high texture parameters are dispensable, e.g., emulsified inlaid frankfurter-type sausages, but high protein content and low fat content desired.

Effect of Storage Time on the Rancidity and Metabolizable Energy of Rice Polishing in Poultry

  • Pasha, T.N.;Khattak, F.M.;Khan, D.R.;Jabbar, M.A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.3
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    • pp.420-425
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    • 2008
  • The storage of rice polishing (RP) with and without addition of antioxidant for sixteen weeks and its effect on rancidity and metabolizable energy values during the summer season was determined. Fifteen Single Comb White Leghorn cockerels of approximately uniform age and weight were procured and kept in metabolic cages under standard feeding and management practices. Five force feeding trials were conducted. In the first trial, fresh RP with 0 weeks of storage (diet 1 and 2) was used followed by four feeding trials with 4 (diet 3, 4), 8 (diet 5, 6), 12 (diet 7, 8), and 16 (diet 9, 10) weeks of storage of RP. The same birds were used in all trails. The birds were fasted for a period of 21 h, followed by force feeding of 20 g of RP with and without antioxidant for all storage periods. The control/fasting group was also maintained to measure endogenous fecal losses. Excreta were collected after 48 h for the determination of AME and TME values of RP. Along with the biological trials, laboratory assay of the RP stored with and without antioxidant was conducted to measure the extent of rancidity in terms of Thiobarbituric acid value (TBA). The TBA values were affected (p<0.05) by storage period and the values increased when the storage period increased from 4 to 16 weeks. However, the TBA values were significantly reduced (p<0.05) when RP was stored after addition of antioxidant when compared with the values obtained from RP stored without antioxidant (diet 3 vs. 4, 5 vs. 6, 7 vs. 8, and 9 vs. 10). The AME MJ/kg and TME MJ/kg values of RP were neither affected by increase in storage period nor addition of antioxidant. The findings of this study revealed that there was no effect of rancidity and storage time on the nutritive value, AME or TME of RP in poultry. However, TBA values were increased with the increase in storage period.

2-Parameter High Frequency Combustion Instability Model (2-파라메타 모델에 의한 고주파 연소불안정 해석)

  • 조용호;윤웅섭
    • Journal of the Korean Society of Propulsion Engineers
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    • v.1 no.2
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    • pp.74-83
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    • 1997
  • The definition of burning admittance and conventional n-$\tau$ stability rating technique are combined to investigate the high frequency combustion instabilities inside the cylindrical combustion chamber. Perturbed flow variables are written as the sum of fluctuating and time-averaged mean quantities on the assumption that the terms of the order higher than unity are sufficiently small, hence linearized governing equations could be formulated. Chamber admittances up and downstream of the flame front calculated with appropriate boundary conditions result in the burning admittance and corresponding n-$\tau$ neutral stability curve. Configurational and operational design factors are tested to detect the unstable wave-induced LOX-RP1 combustion instabilities. Operational design factors, e.g. pressure or O/F ratio, appear less influential to drive high frequency instability while the location of the flame front and configurational factors enhance or deteriorate the stabilities strongly. Conclusively, LOX-RP1 combustion inside the cylindrical combustion chamber is apt to be unstable against long residence time and shortened chamber length.

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The effect of fixation plate use on bone healing during the reconstruction of mandibular defects

  • Hong, Khang Do Gia;Kim, Seong-Gon;Park, Young-Wook
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.45 no.5
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    • pp.276-284
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    • 2019
  • Objectives: This study sought to compare efficiency results between the use of a customized implant (CI) and a reconstruction plate (RP) in mandibular defect reconstruction in an animal model. Materials and Methods: Fifteen rabbits underwent surgery to create a defect in the right side of the mandible and were randomly divided into two groups. For reconstruction of the mandibular defect, the RP group (n=5) received five-hole mini-plates without bone grafting and the CI group (n=10) received fabricated CIs based on the cone-beam computed tomography (CBCT) data taken preoperatively. The CI group was further divided into two subgroups depending on the time of CBCT performance preoperatively, as follows: a six-week CI (6WCI) group (n=5) and a one-week CI (1WCI) group (n=5). Daily food intake amount (DFIA) was measured to assess the recovery rate. Radiographic images were acquired to evaluate screw quantity. CBCT and histological examination were performed in the CI subgroup after sacrifice. Results: The 1WCI group showed the highest value in peak average recovery rate and the fastest average recovery rate. In terms of reaching a 50% recovery rate, the 1WCI group required the least number of days as compared with the other groups ($2.6{\pm}1.3days$), while the RP group required the least number of days to reach an 80% recovery rate ($7.8{\pm}2.2days$). The 1WCI group showed the highest percentage of intact screws (94.3%). New bone formation was observed in the CI group during histological examination. Conclusion: Rabbits with mandibular defects treated with CI showed higher and faster recovery rates and more favorable screw status as compared with those treated with a five-hole mini-plate without bone graft.

Experimental assessment of slamming coefficients for subsea equipment installations

  • de Oliveira, Allan C;Pestana, Rafael G
    • Ocean Systems Engineering
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    • v.10 no.2
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    • pp.163-179
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    • 2020
  • Considering the huge demand of several types of subsea equipment, as Christmas Trees, PLEMs (Pipeline End Manifolds), PLETs (Pipeline End Terminations) and manifolds for instance, a critical phase is its installation, especially when the equipment goes down through the water, crossing the splash zone. In this phase, the equipment is subject to slamming loads, which can induce impulsive loads in the installation wires and lead to their rupture. Slamming loads assessment formulation can be found in many references, like the Recommended Practice RP-N103 from DNV-GL (2011), a useful guide to evaluate installation loads. Regarding to the slamming loads, RP-N103 adopt some simplifying assumptions, as considering small dimensions for the equipment in relation to wave length, in order to estimate the slamming coefficient CS used in load estimation. In this article, an experimental investigation based on typical subsea structure dimensions was performed to assess the slamming coefficient evaluation, considering a more specific scenario in terms of application, and some reduction of the slamming coefficient is achieved for higher velocities, with positive impact on operability.

INVARIANT MEASURE AND THE EULER CHARACTERISTIC OF PROJECTIVELY ELAT MANIFOLDS

  • Jo, Kyeong-Hee;Kim, Hyuk
    • Journal of the Korean Mathematical Society
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    • v.40 no.1
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    • pp.109-128
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    • 2003
  • In this paper, we show that the Euler characteristic of an even dimensional closed projectively flat manifold is equal to the total measure which is induced from a probability Borel measure on RP$^{n}$ invariant under the holonomy action, and then discuss its consequences and applications. As an application, we show that the Chen's conjecture is true for a closed affinely flat manifold whose holonomy group action permits an invariant probability Borel measure on RP$^{n}$ ; that is, such a closed affinly flat manifold has a vanishing Euler characteristic.

Soap-Free Emulsion Polymerization of Styrene/Butadiene/Acrylonitrile System (Styrene/Butadiene/Acrylonitrile계 무유화제 유화중합)

  • Chung, Huey-Sil;Shin, Young-Jo
    • Applied Chemistry for Engineering
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    • v.4 no.2
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    • pp.284-290
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    • 1993
  • The soap-free emulsion polymerization was carried out for Styrene/Butadiene system with Acrylonitrile as hydrophilic comonomer and KPS as initiator. Under the condition of below 50% conversion, the dependence of Rp on $[AN]^n$ and $[KPS]^n$ was found to be n=1.617-1.050 and n=0.83-0.96 for [AN] and [KPS], respectively. The effect of $[AN]^n$ and $[KPS]^n$ on particle number density (Np) was determined to be n=1.533 and n=0.733, respectively. The highest conversion was obtained under the conditions of pH=5 and ratio of total monomer (g) to water (g)=0.5. The mechanical properties of SBR obtained in this experiment were shown to be inferior to commercial SBR in terms of tensile strength, 300% modulus and elongation. It was found that cure rate of SBR prepared in this experiment was faster than that of commercial SBR.

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Isolation of Phenolic Glucosides from the Stems of Acer tegmentosum Max (산겨릅나무 줄기에서 페놀성 글루코사이드의 분리)

  • Hur, Jong-Moon;Yang, Eun-Ju;Choi, Sun-Ha;Song, Kyung-Sik
    • Applied Biological Chemistry
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    • v.49 no.2
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    • pp.149-152
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    • 2006
  • The chemical constituents of Acer tegmentosum Max which belongs to Aceraceae has never been reported. The stems of A. tegmentosum were extracted with MeOH and then successively partitioned with $CH_2Cl_2$, n-BuOH, and $H_2O$ in order to investigate the major phytochemicals. Two compounds were isolated from the n-BuOH fraction through silica gel and RP-18 column chromatographies. Their chemical structures were elucidated as methyl gallate $4-O-{\beta}-D-glucoside$ and salidroside by comparing their spectral data with those in the literature.