• Title/Summary/Keyword: Bio-Engineering

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Reduction of Variable Illumination Effect on Pixel Gray-levels of Machine Vision

  • Suh S. R.;Huang J. K.;Kim Y. T.;Yoo S. N.;Choi Y. S.;Sung J. H.
    • Agricultural and Biosystems Engineering
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    • v.5 no.1
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    • pp.5-9
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    • 2004
  • This study was carried out to develop methods of reducing the effect of solar illumination on pixel gray-levels of machine vision for agricultural field use. Two kinds of monochrome CCD cameras with manual and auto-iris lenses were used to take pictures within a range of 15 to 120 klux of solar illumination. A camera having more precise automatic control functions gave much better result. Four kinds of indices using pixel gray-level of the $99\%$ white DRS (diffuse reflectance standard) as a reference were tried to compensate pixel gray-levels of an image for variable illumination. Coefficients of variation of the indices within a range of illumination were used as a criterion for comparison. The study concluded that an index of (A+B)/A, where A is gray-level of the $99\%$ DRS and B is gray-level of the tested material, gave the best consistency in the range of solar illumination.

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Evaluation of the grouting in the sandy ground using bio injection material

  • Kim, Daehyeon;Park, Kyungho
    • Geomechanics and Engineering
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    • v.12 no.5
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    • pp.739-752
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    • 2017
  • This study was intended to evaluate the improved strength of the ground by applying the bio grouting method to a loose sandy ground. The injection material was prepared in the form of cement-like powder, with the bio injection material produced by microbial reactions. The grouting test was conducted under the conditions similar to the field where the bio injection material can be applied. In addition, the injection materials (cement and sodium silicate No. 3) used for Labile Waterglass (LW) method and the conventional grouting methodwere prepared through a two-solution one-step process. The injection into the specimens was done at a pressure of 150 kPa and then, with a bender element, their moduliof elasticity were measured on the 7th, 14th, 21st and 28th curingdays to analyze their strengths according to the duration of curing. It was confirmed that in all injection materials the moduli of elasticity increased over time. In particular, when 30% of the bio injection material was added to 100% cement, the modulus of elasticity tended to increase by about 15%. This confirmed that the applicability became higher when the bio injection material was used in place of the conventional sodium silicate.

BioPlace: A Web-Based Collaborative Environment for Effective Genome Research

  • Ahn, Geon-Tae;Kim, Jin-Hong;Kang, Kyung-Mi;Lee, Myung-Joon;Han, In-Seob
    • Journal of Microbiology and Biotechnology
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    • v.14 no.5
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    • pp.1081-1085
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    • 2004
  • Genome research has become very popular in most nations. In order to enhance the efficiency of collaboration among genome research groups, ways to store and share data, communicate with each other, be guided through right research strategies, and to easily use well-established databases. In addition, since techniques and softwares for genome research groups are well established, a similar research road map could commonly be applied. In this study, we developed a web-based work place for effective genome research, named 'BioPlace.' From the beginning of writing a proposal, research members can work on the same environment with convenient aid to share files or data. BioPlace provides various ways of collaboration methods among genome researchers. The BioPlace system supports two types of workplaces, namely 'Personal Workspace' and 'Team Workspace.' For each BioPlace user, a Persona] Workspace is provided, while a Team Workspace is provided for each group with the same purpose. In addition, BioPlace provides a 'General Research Road Map' for genome research, and several Korean user interfaces for BLAST, PDB, and Primer3. We expect that BioPlace may facilitate collaboration of genome research among the experienced scientists and help beginners in many different ways as well.

Performance Analysis of a Vacuum Pyrolysis System

  • Ju, Young Min;Oh, Kwang Cheol;Lee, Kang Yol;Kim, Dae Hyun
    • Journal of Biosystems Engineering
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    • v.43 no.1
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    • pp.14-20
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    • 2018
  • Purpose: The purpose of this study was to investigate the performance of a vacuum pyrolysis system, to analyze bio-oil characteristics, and to examine the applicability for farm-scale capacity. Methods: The biomass was pyrolyzed at 450, 480, and $490^{\circ}C$ on an electric heat plate in a vacuum reactor. The waste heat from the heat exchanger of the reactor was recycled to evaporate water from the bio-oil. The chemical composition of the bio-oil was analyzed by gas chromatography-mass spectrometry (GC-MS). Results: According to the analysis, the moisture content (MC) in the bio-oil was approximately 9%, the high heating value (HHV) was approximately 26 MJ/kg, and 29 compounds were identified. These 29 compounds consisted of six series of carbohydrates, 17 series of lignins, and six series of resins. Conclusions: Owing to low water content and the oxygen content, the HHV of the bio-oil produced from the vacuum reactor was higher by about 6 MJ/kg than that of the bio-oil produced from a fluidized bed reactor.

Synthesis and Properties of Bio-Thermoplastic Polyurethanes with Different Isocyanate Contents

  • Li, Xiang Xu;Sohn, Mi Hyun;Cho, Ur Ryong
    • Elastomers and Composites
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    • v.54 no.3
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    • pp.225-231
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    • 2019
  • Bio-based polyester polyol was synthesized via esterification between azelaic acid and isosorbide. After esterification, bio-based polyurethanes were synthesized using polyester polyol, 1,3-propanediol as the chain extender, and 4,4'-diphenylmethane diisocyanate, in mixing ratios of 1:1:1.5, 1:1:1.8, 1:1:2, and 1:1:2.3. The bio TPU (Thermoplastic Polyurethane) samples were characterized by using FT-IR (Fourier Transform Infrared Spectroscopy), TGA (Thermal Gravimetric Analysis), DSC (Differential Scanning Calorimetry), and GPC (Gel Permeation Chromatography). The mechanical properties (tensile stress and hardness) were obtained by using UTM, a Shore A tester, and a Taber abrasion tester. The viscoelastic properties were tested by an Rubber Processing Analyzer in dynamic strain sweep and dynamic frequency test modes. The chemical resistance was tested with methanol by using the swelling test method. Based on these results, the bio TPU synthesized with the ratio of 1:1:2.3, referred to as TPU 4, showed the highest thermal decomposition temperature, the largest molecular weight, and most compact matrix structure due to the highest ratio of the hard segment in the molecular structure. It also presented the highest tensile strength, the largest elongation, and the best viscoelastic properties among the different bio TPUs synthesized herein.