• Journal of Biosystems Engineering
• /
• 제31권6호
• /
• pp.474-481
• /
• 2006

In this paper, a new type blow head was developed and pneumatic application system was evaluated. The blow head had one operating factor, inserting length of collecting plate, that was directly related to discharge rate and application pattern. To determine Proper blow head arrangement and application height, a blow head set was tested. Three-way ANOVA was conducted to investigate relationships between CV value, the discharge rate and inserting length of collecting plate. The discharge rate and inserting length of collecting plate were statistically significant at p=0.01, affecting uniformity of application pattern. The best CV value among the application tests was 23.3% when the application rate and application height was 23.5 g/sec and 80 cm respectively. The worst CV value was 63.3% in 111.4 g/sec. Therefore, it is necessary to increase number of blow head in a section of the boom in improve application uniformity.

• 한국농공학회지
• /
• 제43권2호
• /
• pp.105-111
• /
• 2001

This study is performed to develop an agricultural hydraulic structure for collecting and draining pipe using polymer concrete. The water permeability of collecting and draining pipe shows an 5.917$\ell$/$\textrm{cm}^2$/h, it is more 190 times as large as in the world maximum rainfall. The external pressure on the collecting and draining pipe is in the range of 1.85~5.25tf/m under 2-edge test, 2.6~6.2tf/m under sand mat and the vertical displacement is in the range of 0.48~1.06mm, 1.01~1.89mm, respectively. Also, an increasing rate of external pressure on the developed pipe is higher than that of PVC pipe to the variation of t/D. Accordingly, the pipe developed in this study will be used widely in agricultural hydraulic structures such as collecting and draining structure.

• Journal of Biosystems Engineering
• /
• 제43권1호
• /
• pp.21-29
• /
• 2018

Purpose: The objective of this study is to evaluate the performance of the conical solar concentrator (CSC) system, whose design is focused on increasing its collecting efficiency by determining the optimal conical angle through a theoretical study. Methods: The design and thermal performance analysis of a solar concentrator system based on a $45^{\circ}$ conical concentrator were conducted utilizing different mass flow rates. For an accurate comparison of these flow rates, three equivalent systems were tested under the same operating conditions, such as the incident direct solar radiation, and ambient and inlet temperatures. In order to minimize heat loss, the optimal double tube absorber length was selected by considering the law of reflection. A series of experiments utilizing water as operating fluid and two-axis solar tracking systems were performed under a clear or cloudless sky. Results: The analysis results of the CSC system according to varying mass flow rates showed that the collecting efficiency tended to increase as the flow rate increased. However, the collecting efficiency decreased as the flow rate increased beyond the optimal value. In order to optimize the collecting efficiency, the conical angle, which is a design factor of CSC, was selected to be $45^{\circ}$ because its use theoretically yielded a low heat loss. The collecting efficiency was observed to be lowest at 0.03 kg/s and highest at 0.06 kg/s. All efficiencies were reduced over time because of variations in ambient and inlet temperatures throughout the day. The maximum efficiency calculated at an optimum flow rate of 0.06 kg/s was 85%, which is higher than those of the other flow rates. Conclusions: It was reasonable to set the conical angle and mass flow rate to achieve the maximum CSC system efficiency in this study at $45^{\circ}$ and 0.06 kg/s, respectively.

• 토지주택연구
• /
• 제10권2호
• /
• pp.53-58
• /
• 2019

Particulate matter (PM) is designated as a group 1 carcinogen by the International Agency for Research on Cancer (IARC) of the World Health Organization (WHO). In South Korea, the health threat caused by PM is the most serious level internationally. Therefore, in order to solve the urban PM problem, it is important to develop the technology that can control PM efficiently. In this study, CFD(Computational Fluid Dynamics) simulation was performed for PM pre-filter (type 1-3 with different PM collecting room) to develop a high-efficiency PM collecting device. The complex flow field and the local flow phenomenon inside the PM collecting device were understood with CFD simulation by changing the shape and size of the pre-filter. The PM removal performance can be described with flow rate through the device and PM removal efficiency. The type-1 pre-filter with 5x5 size collecting room was confirmed to have the highest efficiency. Based on the analysis results, the optimal type of pre-filter could be developed and it would be applied as an element technology included in the PM collecting device.

• 한국환경과학회지
• /
• 제22권9호
• /
• pp.1187-1197
• /
• 2013

The result of a small electrostatic precipitator which is in order to decrease indoor air pollution for optimal efficiency was shown as follows. Although the closer distance between the discharge electrode and dust collecting electrode shows the better throughput efficiency by forming strong electrostatic Field, it does not have profound impact in case of optimal dust collecting area. G.P(gas passage) which is the distance from dust collecting electrode to dust collecting electrode is a crucial factor to decide dust collecting efficiency. The narrower distance of G.P shows the better throughput efficiency whereas it decreases when the distance is too narrow since sparks ensue by increasing the capacity of electrostatic charging system 5 mm regards as optimal efficiency in this experiment. Although the higher voltage shows the higher dust collecting efficiency overall, the experiment was not able to keep performing since the sparks which decrease dust collecting efficiency ensue over 40 kV. The efficient and safe voltage state is considered 3.6 kV in this experiment. The most crucial factor for dust collecting efficiency of an electrostatic precipitator which is in order to decrease indoor air pollution is applied voltage. In addition, optimal raw gas flow rate(2.4 m/sec) is more important factor than the excessive increase of dust collecting area.

• 대한기계학회논문집
• /
• 제18권2호
• /
• pp.432-445
• /
• 1994

From a theoretical analysis point of view, the 2-stage precipitator is decomposed into two units: charging cell and collecting cell. Collection efficiency predictions of the two-stage parallel-plate electrostatic precipitator have been performed theoretically incorporating with the charging and the collecting cells. Particle trajectorise passing the charging cell have been modeled as a simple one. Particle charge distribution at the outlet of the charging cell is calculated through integration of the present unipolar combined charging rate along the entire particle trajectory, and average charge of particles at the outlet of the charging cell is obtained from the particle charge distribution. As for the collecting cell, the diminution of particle concentration along the longitudinal direction of the collecting cell is investigated considering the conventional Deutsch's theory and the laminar theory. One should note that the collection efficiency formula derived is based on monodisperse aerosols. It has been confirmed through the analysis that predictions of particle charge by applying White's unipolar diffusion charging theory overpredict actual cases in the continuum regime, while predictions by Fuch's unipolar diffusion charging theory indicate the reasonable result in the same regime. Theoretical predictions of collection efficiency are also compared with the available experimental results. Comparisons show that the experimental results are consistently located in the collection efficiency region bounded by the two limits, the Deutsch and the laminar collection efficiencies. Finally design parameters of the 2-stage electrostatic precipitator have been investigated systematically through the one-variable-at-a-time method in terms of collection efficiency. Applied voltages on the corona wire of the charging cell and the plate of the collecting cell, and the average air velocity have been selected as the design parameters.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2003년도 ICCAS
• /
• pp.1945-1950
• /
• 2003

Conceived to acquire personal information for an electronic medical record, the clinical interview contains probing questions. The number and type of inquiries are assumed to fulfill medical protocols, and therefore are deemed essential for treatment - but the rate can and should be controlled. High rates of inquiry merely intimidate the patient and affect replies. The purpose of this paper is to mathematically formulate permissible rates of clinical interviews held during telehomecare virtual visits and designed to avoid patient anxiety. Mental stress is derived as a function of the weight of importance assigned by the patient, virtual visit duration, and the rate of questioning in the direction of greater sensitivity. Two operations are of interest: Collecting and recording information by the provider, and maintaining synchrony of questions and answers by the patient. The Lorentz transformation yields the patient’s view of the operational rates. Conservation of information momentum is postulated and applied before and after replies are recorded. It is shown that the weight of importance designated by the patient to collecting and recording personal information is driven by a singularity that depends on the rate of questioning. The findings should serve as a guideline in interviewer training programs.

• 기본간호학회지
• /
• 제2권2호
• /
• pp.131-137
• /
• 1995

Improving validity and reliability is the important components of clinical laboratory tests. And the quality control of the test should be started with the accurate collection of specimen. Urinalysis is one of the useful and common tests in diseases diagnosis and determining the process of medical treatment. Since urinalysis is requested routinely in hospital setting, the importance of the quality control for urine specimen is often ignored. To improve the validity of urinalysis, a clinical trial was done on the method of collecting urine specimen. The result was as follows : 1. The rate of presumtive UTI(urinary tract infection) was decreased in 21.6% with experiment method for collecting urine specimen. 2. The rate of presumtive UTI in female patients was decreased in 43.2% with the experiment method. 3. The rate of negative urine culture was decreased in 6.6% with the experiment method.

• Plant Resources
• /
• 제8권1호
• /
• pp.13-16
• /
• 2005

This study was conducted to develop effective production system in greenhouse for leaves and stems of Angelica acutiloba by fertilizing of Sta-Green in pots. The results obtained are summarized as follows. Germination rate of Angelica acutiloba seeds collected in 2003 was $13\%$, while germination rate of seeds Collected in 2004 was above $91\%$. Seed germination rate and plant biomass of Angelica acutiloba collected in 2004 were higher than seed gathering in 2003. Especially, plant growth and yield of Angelica acutiloba grown in pot(The pots was filled with soil mixtures of Sta-Green and Peat Moss mixed with 45:55 ratio.) was the highest. These results indicate that leaf and stem production of Angelica acutiloba can be improved by fertilizing of Sta-Green in pots and optimizing seed collecting time in greenhouse.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회B
• /
• pp.2615-2620
• /
• 2007

This paper describes on pressure drop in a circular pipe of refuse collecting system. The flow characteristics inside the circular pipe are analyzed by three-dimensional Navier-Stokes analysis. In numerical analysis, an organic waste is modeled using the data obtained by site survey. Pressure drop obtained by numerical simulation is compared to the value obtained by experimental measurements for the two kinds of pipe; straight and bended type. The pressure drop obtained by numerical simulation has a good agreement with that of experiments. It is noted that the accurate prediction of pressure drop in the waste pipe is very important to determine the performance of turbo blower used in making a suction pressure in the waste pipe. Especially, the pressure drop for an organic waste is analyzed according to the mass flow rate of waste.