• Journal of ILASS-Korea
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• v.28 no.3
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• pp.143-149
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• 2023

Amidst the drive towards carbon neutrality, interest in renewable synthetic e-fuels is rising rapidly. These fuels, generated through the synthesis of atmospheric carbon and green hydrogen, offer a sustainable solution, showing advantages like high energy density and compatibility with existing infrastructure. The physical properties of e-fuels can be different from those of conventional gasoline based on manufacturing methods, which requires investigations into how the physical properties of e-fuels affect the fuel injection characteristics. This study performs a comparative analysis between conventional and Fischer-Tropsch (F-T) synthetic gasoline (e-gasoline) across various fuel temperatures, including the cold start condition. The fuel properties of F-T synthetic and conventional gasoline are analyzed using a gas chromatography-mass spectrometry technique and the injection rates are measured using a Bosch-tube injection rate meter. The F-T synthetic gasoline exhibited higher density and kinematic viscosity, but lower vapor pressure compared to the conventional gasoline. Both fuels showed an increase in injection rate as the fuel temperature decreased. The F-T synthetic gasoline showed higher injection rates compared to conventional gasoline regardless of the fuel temperature.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.3
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• pp.455-462
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• 2023

In this study, an automatic spraying lubrication system was developed to maintain the cleanliness of the switchgear when detecting the movement of the track through the switchgear. To develop this system, an air tank, valve block, and spray nozzle were designed, and the safety was secured through the pressure test of the prototype after designing the air tank. Furthermore, the environmental aspect was considered by minimizing the use of lubricant by enabling the mixing of air and lubricant through the production of a valve using the Venturi principle. The performance evaluation was conducted by implementing (producing) the injection system, and the product developed in this study was deemed installable in actual switchgear. It is expected that the proposed system will enable the maintenance of the cleanliness of the track during switching and reduce faults and malfunctions caused by switchgear defects.

• Journal of Wellbeing Management and Applied Psychology
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• v.6 no.2
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• pp.9-13
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• 2023

Purpose: In this study, we would like to make a technical proposal to solve the odor problem in pig houses. Through this, we would like to suggest an effective way to reduce the odor generated in the pig house as a solution to civil complaints. Research design, data and methodology: Conduct direct visits to pig farms where many civil complaints about bad odor occur, and identify the problems of each farm. Identify elements related to odor control, such as structure, facility, equipment, odor management method, and ventilation type. Through this, the technology to be applied to reduce odor and the solution to the odor problem are presented. Results: The results of major improvements are as follows: 1. Improvement of the structure of the barn or composting shed to an airtight type 2. Improvement of the pig manure treatment structure using the slope inside the barn 3. Establishment of ventilation and cooling systems 4. Automation of the mist spray system. Conclusions: As a result, as practical measures, sealing of facilities using winch curtains, construction of air conditioning systems using negative pressure ventilation, and management systems using AIoT systems were presented. It is judged that this study can be helpful in determining the grievances caused by civil complaints of tenant livestock farms and the direction of facility improvement in the future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.487-493
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• 2020

Recently, the ministry of environment banned the use of the existing airless method using the spray in painting industrial facilities. Therefore, it is necessary to develop a pressure-roller attached to existing airless painting systems. The hole design of the SUS piping and drum-bases of pressure-rollers currently developed and sold have not been studied in detail, so their efficiency is questionable. In particular, if sufficient paint is not supplied to both ends of the roller, it is necessary to rework with a brush after painting. Therefore, the holes of the drum base need to be distributed so that the paint can flow to both ends of the roller. In this study, numerical analysis was performed to determine the effects of the hole design in the SUS piping and drum-base on the flow patterns of the paint and to suggest more efficient design measures. The analysis results showed that the uniform placement of the holes in the SUS piping is good for the balanced inflow of the paint. For the drum-base, the paint can flow better into both ends of the roller when the holes are concentrated and machined on both ends of the drum-base.

• Journal of Biosystems Engineering
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• v.7 no.2
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• pp.30-35
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• 1983

To investigate the factors affecting the transportability of spray droplets, the maximum distance, the effective distance, the ratio of even distribution, and the diameters of particles were measured in accordance with the different pressure levels of power sprayer using 3 hole swath type nozzle, and the results are summerized as follows; 1. The distance of the most dense point from the nozzle was shortened by 0.5 meter with the 100-meter-long hose. The maximum reaching distances were reduced by 1.5 and 1.0 meters for the 13m/m and the 8.5 m/m hoses respectively, and the effective distance were reduced by 0.5 meter for both cases. 2. The effective distance can not be extended beyond 14 meters even if the length of hose is minimized at the rated pump pressure 28 kg/$cm^2$, it was 1 meter longer for 13m/m hose compared to the 8.5m/m one. 3. In case of 13m/m hose, the most dense point can be extended further by 0.5 meter increasing the pump pressure by 8 kg/$cm^2$, and the maximum distance and effective distance were increased by 2.0 and 0.5 meters respectively. There was no significant effect of pressure changes on the transportability in case of 8.5m/m hose. 4. Both the reduction of hose length and the increase of pump pressure influenced in large extent to the atomization effect of droplets. It was noticed that the diameter of droplet is related to the pump pressure and inside diameter of hose. 5. The pressure drop in 100-meter-long and l3m/m hose was 5~7kg/$cm^2$ at the pump pressure range of 25~33kg/$cm^2$, and it is an equivalent of 2% per 10 meter length of hose.

• Korean journal of applied entomology
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• v.44 no.2
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• pp.115-123
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• 2005

Historical changes of population abundances of European red mite (ERM), Panonychus ulmi (Koch), and two-spotted spider mite (TSSM), Tetranychus urticae (Koch) (Acari: Tetranychidae), were described in selected apple orchards in the National Horticultural Research Institute (NHRI, Suwon, Korea), based on research reports of the NHRI from 1958 to 1998. ERM was an abundant species up to 1970, and TSSM became a dominant species after 1980. The change occurred around mid 1970. Three hypotheses were made to explain the change: TSSM competitively replaces ERM, ground cover weeds are a major influencing factor on movement of TSSM (TSSM movement into trees is accelerated by destroying weeds), and ERM and TSSM populations are regulated by natural enemy complexes when the orchard system is not disrupted. And long-term results of the interaction between two species were projected according to the combination of different orchard management strategies: pesticide sprays (non-selective toxic pesticide spray : heavy pesticide pressure (HPP), and selective soft pesticide spray = low pesticide pressure (LPP)) and weed control methods (grass planting, and clean culture system with herbicides). In the HPP and grass planting system, ERMs are abundant because ERM can avoid competition with TSSM as movement of TSSM to trees are restricted, and natural enemy complexes are destroyed by toxic pesticides. In the HPP and clean culture system, TSSMs are abundant because TSSM moves to trees from early season and competitively replaces ERM. In the LPP and grass planting system, ERMs are abundant because movement of TSSM to trees is reduced, but they do not build up a high population density since their densities are regulated by natural enemy complexes. In the LPP and clean culture system, TSSM moves to trees and competes with ERM, but the competition pressure is reduced because population densities of mites are regulated in a lower level by natural enemy complexes. So, ERM can occurs in late season. Thus, two species can coexist temporarily with more ERM in early season and more TSSM in late season. TSSM abundant phenomenon presented in this study can be partially explained as a result of long-term interaction between ERM and TSSM under the HPP and clean culture system.

• Journal of Animal Environmental Science
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• v.13 no.2
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• pp.105-112
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• 2007

This research was carried out to test and analyse the capability of a fan for development of a sprayer in actual livestock farm. A fan was designed and made to be able to spray agricultural chemicals within 140mm in a maximum scattering range and 100m in an effective scattering range. Accordingly, its' flow rate was $3,600\;m^3/min$, and static pressure was 100 mmAq for a wide area sprayer to be sprayed widely and far. Fan performance, which was given $600\;m^3/min$ flow rate and 500 mmAq total pressure, was tested fur basic experiment. As the result, the axial power showed minimum error, which be designed to keep the fan performance. And power efficiency was the maximum. Sound level was 92.1dB that wasn't enough to environmental standard. If we take the sealed place into consideration, sound level is suitable for environmental standard.

• Journal of Yeungnam Medical Science
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• v.24 no.2
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• pp.162-169
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• 2007

Purpose : It is well known that suspension microlaryngeal surgery produces marked increases in arterial blood pressure and heart rate. In this study, we evaluated the effects of 10% lidocaine preoperatively sprayed for attenuation of the perioperative hemodynamic response during suspension microlaryngeal surgery. Materials and Methods : Fifty American Society of Anesthesiologists (ASA) class 1 patients scheduled for excision of a vocal polyp by suspension laryngoscopy were randomly divided into two groups (n=25 for each group). They were intubated without 10% lidocaine spray (control group) or given 1.5 mg/kg of 10% lidocaine sprayed onto the pharyngolaryngeal and intratracheal sites 90 sec prior to intubation (10% lidocaine group). Anesthesia was maintained using desflurane in $O_2/N_2O$ 50%. The arterial blood pressure and heart rate were measured at preinduction (T0), 1 min (T1), 3 min (T2), 5 min (T3) after tracheal intubation, and 1 min (T4), 3 min (T5), 5 min (T6) and 10 min (T7) after the suspension laryngoscopy. Results : In the 10% lidocaine group, the arterial blood pressure and heart rate at 1 (T1), 3 (T2) min after tracheal intubation and 1 (T4), and 3 (T5) min after suspension laryngoscopy were lower than the same measurements in the control group. Conclusion : 10% lidocaine sprayed onto the pharyngolaryngeal and intratracheal sites before intubation was an effective method for attenuation of the perioperative hemodynamic response during suspension microlaryngeal surgery.

• The Korean Journal of Pesticide Science
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• v.16 no.3
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• pp.230-235
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• 2012

This study was carried out to clarify effects of field location and sprayer on the level of pesticide residue in chilli peppers. As confirmed by statistical analysis, the residue levels in green pepper among three greenhouses did not show significant difference at the first day after spraying with the same engine sprayer and nozzle. But the residue levels in green peppers collected from the exposed outside of crop were 2 times higher than those from the hidden inside. The sampling site was one of variation elements of pesticide residue. The residue levels after application by knapsack engine powered sprayer were 1.7 times higher than those by manual compressed sprayer. As the spraying pressure of the engine power sprayer is 2 times higher than the commonly used pressure of the manual compressed sprayer, the pressure of the sprayer and nozzles were considered to affect on the residue levels in peppers.

• Journal of Energy Engineering
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• v.24 no.3
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• pp.96-108
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• 2015

A passive containment cooling system has been designed to remove the heat inside a containment during accidents without external power supply. In this work, the PCCS was introduced in the APR1400 plant to replace the containment spray system and, then, the thermal-hydraulic performance of the PCCS was analyzed using the system thermal-hydraulic computer code, MARS. A double-ended cold-leg break accident, which is known to induce the maximum pressure in the containment, is simulated, where the thermal hydraulics of the PCCS, the reactor coolant system, and the containment are simultaneously simulated. The results of the calculations showed that the PCCS can replace the existing spray system and that the containment building and its internal structure also play a very important role for the heat removal during the accident. Some sensitivity calculations were carried out to evaluate the model uncertainty and the effects of design parameters. The limitations of the PCCS are also discussed.