• 제목/요약/키워드: Micro formulation

검색결과 87건 처리시간 0.02초

Development of Sustainable Releasing Micro Formulation System using γ-Irradiation Technique to Control Phytophthora Blight Disease

  • Park, Hae-Jun;Kim, Hwa-Jung;Kim, Dong Ho
    • 방사선산업학회지
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    • 제5권4호
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    • pp.305-311
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    • 2011
  • We introduced a novel sustainable slow-releasing agrochemical formulation, a biopolymer bound to silica, for controlling plant diseases. The formulation was obtained through the following process. Curdlan, sodium silicate ($Na_2SiO_3$) and isopropyl alcohol were dissolved in DDW (Deionized-distilled water). The resultant solution was then irradiated using a $^{60}Co$ ${\gamma}$-irradiator (150 TBq of capacity; ACEL, Canada) at KAERI. The resultant solution was treated with phosphorous acid ($H_3PO_3$). Finally, we obtained a novel biopolymer-silica microsized formulation containing phosphorous acid ($H_3PO_3$) from the solution. The morphology of the complex was characterized using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). SEM and TEM images revealed that the curdlan-silica formulation has a particle size ranging from 1 to $3{\mu}m$ with high stability. We also detected that $H_3PO_3$ was distributed within the formulation through energy dispersive X-ray spectroscopy (EDX) analysis. $H_3PO_3$ was sustain-released from the formulation in water. Based on our results, it seems effectively that one or two applications of the formulation during a cropping season will assist in controlling various plant diseases.

감마선 조사기술을 이용한 미량원소 비료 나노제제 제조 (Preparation of a Nanosized Micro Element Fertilizer Formulation by using Gamma-irradiation Technique)

  • 박해준;김화정
    • 방사선산업학회지
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    • 제4권4호
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    • pp.347-352
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    • 2010
  • In this study, we addressed a novel nanosized curdlan-silica complex, which is curdlan bound to silica, for the development of a sustain-releasing micro element fertilizer formulation. The complex was obtained as follow steps; First, Curdlan polymer, sodium silicate ($Na_2SiO_3$) and isopropyl alcohol were dissolved in DDW. Next the resultant solution was irradiated by $^{60}Co$ gamma-irradiator (150 TBq of capacity; ACEL, Canada). Then $MgSO_4$ was treated with the resultant solution. The obtained colloidal solution was dried by freeze dryer. Finally, we obtained a novel nanosized curdlan-silica formulation containing $MgSO_4$ from the colloidal solution. The morphology of the complex was characterized by using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The nanosized curdlan-silica complex has a particle size ranging from 20 to 80 nm and high stability. Our results suggested that the nano-complex can be applicable to use in various sustain-releasing formulation for pesticide delivery system (PDS).

A new four-unknown refined theory based on modified couple stress theory for size-dependent bending and vibration analysis of functionally graded micro-plate

  • Amar, Lemya Hanifi Hachemi;Kaci, Abdelhakim;Yeghnem, Redha;Tounsi, Abdelouahed
    • Steel and Composite Structures
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    • 제26권1호
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    • pp.89-102
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    • 2018
  • This work investigates a novel plate formulation and a modified couple stress theory that introduces a variable length scale parameter is presented to discuss the static and dynamic of functionally graded (FG) micro-plates. A new type of third-order shear deformation theory of Reddy that use only 4 unknowns by including undetermined integral variables is proposed in this study. The equations of motion are derived from Hamilton's principle. Analytical solutions are obtained for a simply supported micro-plate. Numerical examples are presented to examine the effect of the length scale parameter on the responses of micro-plates. The obtained results are compared with the previously published results to demonstrate the correctness of the present formulation.

불확실 변수에 대한 구배 최소화를 이용한 강건 최적 설계와 마이크로 자이로스코프에의 응용 (Robust Design in Terms of Minimization of Sensitivity to Uncertainty and Its Application to Design of Micro Gyroscopes)

  • 한정삼;곽병만
    • 대한기계학회논문집A
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    • 제26권9호
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    • pp.1931-1942
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    • 2002
  • In this paper a formulation of robust optimization is presented and illustrated by a design example of vibratory micro gyroscopes in order to reduce the effect of variations due to uncertainties in MEMS fabrication processes. For the vibratory micro gyroscope considered it is important to match the resonance frequencies of the vertical (sensing) and lateral (driving) modes as close as possible to attain a high sensing sensitivity. A deterministic optimization in which the difference of both the sensing and driving natural frequencies is minimized as an objective function results in highly enhanced performance but apt to be very sensitive to fabrication errors. The formulation proposed is to attain robustness of the performance by including the sensitivity of the response with respect to uncertain variables as a term of objective function to be minimized. This formulation is simple and practically applicable since no detail statistical information on fabrication errors is required. The geometric variables, beam width, length and thickness of vibratory micro gyroscopes are adopted as design variables and at the same time considered as uncertain variables because here occur the fabrication errors. A robustness test in terms of a percentage yield by using the Monte Carlo simulation has shown that the robust optimum produces twice more acceptable designs than the deterministic optimum. Improvement of robustness becomes bigger as the amount of fabrication errors is assumed larger. Considering that the magnitude of fabrication errors and uncertainties in a MEMS structure are comparatively large, the present method is illustrated to be a viable approach for a robust MEMS design.

Micro-Grids Reliability Enhancement Under Different Penetration Levels of Hybrid DG Units

  • Essam, M.;Atwa, Y.M.;El-Saadany, Ehab F.;Conti, Stefania;Rizzo, Santi Agatino
    • Journal of Electrical Engineering and Technology
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    • 제13권4호
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    • pp.1407-1418
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    • 2018
  • Novel mechanism of customized adequacy formulation is proposed in order to enhance micro grids system reliability. The mechanism accounts for 2-levles of load curtailment, and is mainly based on probabilistic load profile and hybrid Distributed Generation (DG) units modeling. The two load curtailments are needed in order to ensure adequate technical constraints at steady state condition during islanding mode of operation. The effectiveness of the proposed formulation has been verified using system independent analytical expressions for the evaluation of both reliability and Expected Energy Not Served (EENS) indices. The evaluation has examined the impact of different penetration levels of Hybrid DG Units in case study islands. Results show the enhancement of the overall distribution system reliability and the recommended conditions for successful islanding mode of operation.

Micro-scale dependent static stress and strain analyses of thickness-stretching micro plate in sport application

  • Mingjun Xia
    • Advances in concrete construction
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    • 제15권5호
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    • pp.349-358
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    • 2023
  • Aim of this work is investigating effect of thickness-stretching formulation on the quasi three-dimensional analysis of micro plate based on a thickness-stretched and shear deformable model through principle of virtual work and micro-scale dependent constitutive relations. Governing differential equations are derived in terms of five unknown functions and the analytical solution is derived using Navier's technique. To explore effect of thickness stretching model on the static results, a comparison between the results with and without thickness stretching effect is presented.

결정소성학에 의한 미세 성형공정의 유한요소해석 (Finite Element Analysis of Micro Forming Process by Crystal Plasticity)

  • 김흥규;오수익
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2001년도 춘계학술대회 논문집
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    • pp.209-212
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    • 2001
  • It is known that the mim forming processes show somewhat different phenomena compared with the conventional metal forming processes, namely, the size effect, enhanced friction effect and etc. Such typical phenomena, however, are not predicted by the conventional finite element analysis, which has been an efficient numerical tool to predict the metal forming processes. It is due to the fact that the constitutive relations used does not describe the microstructural characteristics of the materials. In the present investigation, the finite element formulation using the rate-dependent rigid plastic crystal plasticity model of the face-centered cubic materials is conducted to predict the micro mechanical behaviors during the mim forming processes. The finite element analysis, however, provides mesh-dependent solutions for the intragranular deformations. Therefore, the couple stress energy is additionally introduced into the variational principle and formulated within the framework of the rigid plastic finite element method to obtain mesh-independent solutions. Micro deformations of single crystal and bicrystal with various orientations are calculated to show the potential of the developed formulation.

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구배 지수에 근거한 강건 최적 설계 기법을 이용한 공진형 미소탐침의 강건 최적화 (Robust Optimization of a Resonant-type Micro-probe Using Gradient Index Based Robust Optimal Design Method)

  • 한정삼;곽병만
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.1254-1261
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    • 2003
  • In this paper we present a simple and efficient robust optimal design formulation and its application to a resonant-type micro probe. The basic idea is to use the Gradient Index (GI) to improve robustness of the objective and constraint functions. In the robust optimal design procedure, a deterministic optimization for performance of MEMS structures is followed by design sensitivity analysis with respect to uncertainties such as fabrication errors and change of operating conditions. During the process of deterministic optimization and sensitivity analysis, dominant performance and uncertain variables are identified to define GI. The GI is incorporated as a term of objective and constraint functions in the robust optimal design formulation to make both performance and robustness improved. While most previous approaches for robust optimal design require statistical information on design variations, the proposed GI based method needs no such information and therefore is cost-efficient and easily applicable to early design stages. For the micro probe example, robust optimums are obtained to satisfy the targets for the measurement sensitivity and they are compared in terms of robustness and production yield with the deterministic optimums through the Monte Carlo simulation.

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핵비등에서의 기포거동에 관한 수치해석 (Numerical Simulation of Bubble Motion During Nucleate Boiling)

    • 대한기계학회논문집B
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    • 제25권3호
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    • pp.389-396
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    • 2001
  • Direct numerical simulation of bubble growth and merger process on a single nucleation site during partial nucleate boiling is performed. The equations governing conservation of mass, momentum and energy are solved using a finite difference method combined with a level set method for capturing the vapor-liquid interface. The level set method is modified to include the effects of phase change at the interface and contact angle at the wall. Also, a simplified formulation for predicting the evaporative heat flux in a thin liquid micro-layer is developed and incorporated into the level set formulation. Based on the numerical results, the bubble growth and merger pattern and its effect on the heat transfer are discussed.

Markov 연쇄 MCM을 이용한 마이크로 흐름센서 열전달 해석 (Thermal Transfer Analysis of Micro Flow Sensor using by Markov Chain MCM)

  • 차경환;김태용
    • 한국정보통신학회논문지
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    • 제12권12호
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    • pp.2253-2258
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    • 2008
  • 산화물 반도체 감지막이 동작온도에 따라 감응특성을 가지는 마이크로 흐름센서를 설계하기 위해서 통계적 수법에 기초한 Markov 체인 MCM을 이용하여 기초방정식을 정식화하고 마이크로 소자의 열 전달특성을 해석하였다. 계산 결과를 통하여 기존 유한차분법이 가지는 계산 정밀도와 차이가 없음을 확인하였다. 본 논문에서 제안한 Markov 체인 MCM을 활용하면 다양한 마이크로 소자의 열전달 특성과 같은 물리적 특성을 해석하고 설계하는데 유용할 것으로 판단된다.