• Title/Summary/Keyword: Sample preparation effect.

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Specimen Preparation for Scanning Electron Microscope Using a Converted Sample Stage

  • Kim, Hyelan;Kim, Hyo-Sik;Yu, Seungmin;Bae, Tae-Sung
    • Applied Microscopy
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    • v.45 no.4
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    • pp.214-217
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    • 2015
  • This study introduces metal coating as an effective sample preparation method to remove charge-up caused by the shadow effect during field emission scanning electron microscope (FE-SEM) analysis of dynamic structured samples. During a FE-SEM analysis, charge-up occurs when the primary electrons (input electrons) that scan the specimens are not equal to the output electrons (secondary electrons, backscattered electrons, auger electrons, etc.) generated from the specimens. To remove charge-up, a metal layer of Pt, Au or Pd is applied on the surface of the sample. However, in some cases, charge-up still occurs due to the shadow effect. This study developed a coating method that effectively removes charge-up. By creating a converted sample stage capable of simultaneous tilt and rotation, the shadow effect was successfully removed, and image data without charge-up were obtained.

Effect of Preparation Methods on Yulmoo Kimchi Fermentation (열무 물김치의 담금방법이 발효숙성에 미치는 영향)

  • 장명숙;피재은
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.24 no.6
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    • pp.990-997
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    • 1995
  • Effect of preparation method on Yulmoo kimchi(watery kimchi prepared with Yulmoo, leaf radish) fermentation was investigated by measuring physicochemical, microbiological and sensory properties for 20 days. Yulmoo kimchi was fermented at 4$^{\circ}C$ after keeping at room temperature(27$\pm$0.5$^{\circ}C$) for 8 hours. Four types(A, B, C, D) of Yulmoo kimchi were prepared. Sample A was made without wheat flour paste and red pepper powder and sample B was made with wheat flour paste. Sample C was made with red pepper powder, and sample D was made with wheat flour paste and red pepper powder. pH was slowly lowered and stabled after 10 days in all samples. Total acid content increased in all samples. Reducing sugar content initially increased and decreased thereafter. Especially, reducing sugar content of sample B increased in the early stage of fermentation and maintained initial reducing sugar content after 20 days. Total vitamin C content reduced during fermentation in all samples. Especially initial total vitamin C content of sample D increased more than those of other samples relatiely. Lightness and yellowness showed no difference, but on the other hand redness increased gradually in all samples. The number of lactic acid bactgeria reached maximum value in 10~13 days with the total cell numbers and gradually decreased thereafter in all samples. The number of lactic acid bacteria and total cell number of sample D was much more than those of any other samples. As a result of the sensory evaluation, Yulmoo kimchi showed significant difference in all characteristics. Sample D showed the highest scores in all characteristics before 10 days of fermentation. However, after 10 days sample B showed the highest scores.

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Intergenerational Financial Resource Transfers and Preparation for Later Life in the Middle-Aged (중년기 가정의 세대 간 경제적 자원이전과 노후생활 준비)

  • Kim, Soon-Mi;Koh, Sun-Kang
    • Journal of Family Resource Management and Policy Review
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    • v.16 no.2
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    • pp.59-76
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    • 2012
  • This study examines the relationship between intergenerational financial resource transfers and preparation for later life among the middle-aged. The study sample consists of 1536 middle-aged individuals with at least one living parent and one married child. The level of preparation for later life is dependent upon the level of household economic status. The statistically significant variables predicting the level of preparation for later life include age, education, subjective health status, household income and household assets. Moreover, intergenerational resource transfers are statistically significant factors that explain the level of preparation for later life. The effect of financial transfers from middle-aged parents to their adult children on the level of preparation for later life is the most significant financial transfer variable.

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Preparation and Properties of Waterborne Poly(urethane-urea) Ionomers -Effect of the Type of Neutralizing Agent-

  • Yang, Jung-Eun;Lee, Young-Hee;Koo, Young-Seok;Jung, Young-Jin;Kim, Han-Do
    • Fibers and Polymers
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    • v.3 no.3
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    • pp.97-102
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    • 2002
  • A series of waterbome poly(urethane-urea) anionomers were prepared from isophorone diisocyanate (IPDI), polycaprolactone diol (PCL), dimethylol propionic acid (DMPA), ethylene diamine (EDA), and triethylamine (TEA), NaOH, or Cu($(COOCH_3)_2$) as neutralizing agent. This study was performed to decide the effect of neutralizing agent type on the particle size viscosity, hydrogen bonding index, adhesive strength, antistaticity, antibacterial and mechanical properties. The particle size of the dispersions decreased in the following order: TEA based samples (T-sample), NaOH based samples (N-sample), and Cu($(COOCH_3)_2$) based sample (C-sample). The viscosity of the dispersions increased in the order of C-sample, N-sample, and T-sample. Metal salt based film samples Of and C-sample) had much higher antistaticity than TEA based sample. By infrared spectroscopy, it was found that the hydrogen bonding index (or fraction) of samples decreased in the order of T-sam-pie, N-sample, and C-sample. The adhesive strength and tensile modulus/strength decreased in the order of T-sample, N-sam-pie, and C-sample. The C-sample had strong antibacterial halo, however, T- and N-samples did not

Effect of Sample Preparation on Prediction of Fermentation Quality of Maize Silages by Near Infrared Reflectance Spectroscopy

  • Park, H.S.;Lee, J.K.;Fike, J.H.;Kim, D.A.;Ko, M.S.;Ha, Jong Kyu
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.5
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    • pp.643-648
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    • 2005
  • Near infrared reflectance spectroscopy (NIRS) has become increasingly used as a rapid, accurate method of evaluating some chemical constituents in cereal grains and forages. If samples could be analyzed without drying and grinding, then sample preparation time and costs may be reduced. This study was conducted to develop robust NIRS equations to predict fermentation quality of corn (Zea mays) silage and to select acceptable sample preparation methods for prediction of fermentation products in corn silage by NIRS. Prior to analysis, samples (n = 112) were either oven-dried and ground (OD), frozen in liquid nitrogen and ground (LN) and intact fresh (IF). Samples were scanned from 400 to 2,500 nm with an NIRS 6,500 monochromator. The samples were divided into calibration and validation sets. The spectral data were regressed on a range of dry matter (DM), pH and short chain organic acids using modified multivariate partial least squares (MPLS) analysis that used first and second order derivatives. All chemical analyses were conducted with fresh samples. From these treatments, calibration equations were developed successfully for concentrations of all constituents except butyric acid. Prediction accuracy, represented by standard error of prediction (SEP) and $R^2_{v}$ (variance accounted for in validation set), was slightly better with the LN treatment ($R^2$ 0.75-0.90) than for OD ($R^2$ 0.43-0.81) or IF ($R^2$ 0.62-0.79) treatments. Fermentation characteristics could be successfully predicted by NIRS analysis either with dry or fresh silage. Although statistical results for the OD and IF treatments were the lower than those of LN treatment, intact fresh (IF) treatment may be acceptable when processing is costly or when possible component alterations are expected.

Measurement of Alcohol Contents in Alcoholic Beverages Using a Surface Plasmon Resonance Sensor (표면 플라즈몬 공명 센서를 이용한 주류의 알코올 함량 측정)

  • 조용진;안병학;김철진;김종태
    • Journal of Biosystems Engineering
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    • v.29 no.4
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    • pp.323-328
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    • 2004
  • A surface plasmon resonance (SPR) sensing system, which belonged to a family of thin film refractometry-based sensors, was fabricated to measure the alcohol contents in alcoholic beverages. In this study, a SPR owe was obtained by a photodiode array with 128 pixels and transformed into a refractive index which was calculated by means of the first moment of values below a baseline of 0.85. When the sensing system was applied to Soju, Cheonju, Igwaduju and Tacju highly linear relationships between the refractive index by SPR and the contents of alcohol were obtained. That is, the coefficients of determination in their linear models were 0.992, 0.933, 0.918 and 0.954, respectively. Meanwhile, the effect of sample preparations on the accuracy of measurement was analyzed. As for Soju and Tacju, the best calibration equations were obtained when no sample preparation was applied. The best calibration models for measurement of Cheonju and Igwaduju were obtained through the samples filtered by $C_{18}$ disks.

A curtain traveling pluviator to reconstitute large scale sand specimens

  • Kazemi, Majid;Bolouri, Jafar B.
    • Geomechanics and Engineering
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    • v.14 no.2
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    • pp.131-139
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    • 2018
  • The preparation of repeatable and uniformly reconstituted soil specimens up to the specified conditions is an essential requirement for the laboratory tests. In this study for large samples replication, the simultaneous usage of the traveling pluviation and curtain raining technique is used to develop a new method, called the curtain travelling pluviator (CTP). This simple and cost effective system is based on the air pluviation approach, whilst reducing the sample production time, can reproduce uniform samples with relative densities ranging from 25% to 96%. In order to investigate the resulting suitability and uniformity from the proposed method, a series of tests is performed. The effect of curtain traveling velocity, curtain width, drop height, and flow rate on the parameters of the sample is thoroughly investigated. Increase in the curtain velocity and drop height leads to the increase in relative density for the sand specimen. Increase in curtain width typically resulted in the reduction of relative density. Test results reveal that the terminal drop height for the sand specimen in this study is more than 500 mm. Relative density contour lines are presented that can be utilized in optimizing the drop height and curtain width parameters. Sample uniformity in the vertical and horizontal orientation is investigated through the sampling containers. Increasing relative density tends to result in the higher sample repeatability and uniformity.

Effect of Preparation on Structure and Magnetic Properties of ZnFe2O4

  • Niyaifar, Mohammad
    • Journal of Magnetics
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    • v.19 no.2
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    • pp.101-105
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    • 2014
  • In this work, Zinc ferrite nanoparticles have been prepared by various methods, conventional (ZC), mechanochemical processing (ZM) and Sol-Gel (ZS) method, to compare their structural and magnetic properties. The cation distribution obtained from XRD shows the degrees of inversions are 4%, 14.8%, and 16.4% from the normal $ZnFe_2O_4$ structure. Fourier transform infrared spectroscopy (FT-IR) confirms changes in cation distribution of $ZnFe_2O_4$ fabricated by sol-gel and mechanochemical processing. The $^{57}Fe$ M$\ddot{o}$ssbauer spectra of the samples were recorded at room temperature. The spectra exhibit a line broadening. The magnetic properties of the samples were studied by vibration sample magnetometer (VSM) at room temperature and the results show that the sample ZM has ferrimagnetic behaviour.

A Study on the Effects of Educational Service Quality of Lifelong Education Institutions on Job Preparation Behavior of Adult Learners (평생교육기관 교육서비스품질이 성인학습자의 취업준비행동에 미치는 영향에 관한 연구)

  • Gil, Min Jae;Park, Jong Woo
    • Journal of Korean Society for Quality Management
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    • v.51 no.1
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    • pp.79-96
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    • 2023
  • Purpose: The purpose of this study is to examine the effects of the educational service quality of lifelong education institutions on the job preparation behavior of adult learners, and to suggest important factors that enhance the job preparation behavior of adult learners and ways to contribute to the improvement of educational service quality. Methods: In this study, 260 adult learners using lifelong educational institutions located in Seoul and Gyeonggi-do were statistically analyzed with SPSS 22.0 as a study sample. Results: First, lecturer expertise, educational environment, educational programs, and administrative services of instructors, which are sub-factors of educational service quality, were all adopted as positive (+) influences on educational satisfaction. Second, the lecturer expertise and educational programs were adopted due to the positive (+) effect on job search efficacy, but the educational environment and administrative services were rejected. Third, educational satisfaction was adopted as a positive (+) effect on job search efficacy. Fourth, educational satisfaction was adopted as a positive (+) effect on job preparation behavior. Fifth, job search efficacy was adopted as a positive effect on job preparation behavior. Conclusion: Based on the research results, it suggests that educational satisfaction and job search efficacy are important variables for adult learners using lifelong education institutions, and provides basic data on variables necessary to increase their job effectiveness in a rapidly changing job environment.