Earticle

소규모 하수처리장의 경우 유입수량의 변동폭이 크고 하수관거 노후화로 인한 불명수 유입 등에 의해 하수처리 운영이 어 려운 것으로 보고되고 있다. 특히, 동절기 수온저하로 인한 전반적인 운영문제가 많아 본 연구에서는 산악지역에 위치한 소 규모 하수처리시설의 운영현황과 온도에 따른 수질변화를 분석하였다. BOD, COD, SS의 경우 온도에 따라 방류수 수질 농 도가 크게 변화하는 것으로 나타났으며, 특히 COD가 많은 영향을 받는 것으로 나타났다. 이에 한시적으로 동절기 수온 저 하 대책을 적용하고자 생물반응조 수위를 0.4m 상승시켰으며, 생물반응조 덮개를 설치하고 운영하였을 때 결과를 비교 분 석한 결과 유의미한 개선효과가 발생하였다. 이외 동절기 생물반응조 처리효율 저하에 대한 개선방안을 생물반응조 체류시 간 연장하는 방안으로 생물반응조 규격을 확대하는 방안, 유량조정조를 신설하고 외부반송하는 방안, 무산소에 산기장치를 설치하여 동절기 비상시 호기조로 사용하는 개선방안을 제시하였다. 본 연구결과는 동절기 소규모 하수처리시설 운영방안 에 대한 기초자료로 활용될 수 있을 것으로 판단된다.

In the case of small-scale sewage treatment plants, it is reported that the amount of inflow fluctuates and it is difficult to operate the sewage treatment due to the inflow of unknown water due to the aging of sewage pipes. In particular, there are many overall operational problems due to the decrease in water temperature in winter. In this study, the operation status of small-scale sewage treatment facilities located in mountainous areas and water quality changes according to temperature were analyzed. It was found that the concentration of BOD, COD, and SS in effluent water was greatly changed depending on the temperature, and it was found that COD was particularly affected. Accordingly, the water level of the bioreactor was raised by 0.4m in order to temporarily apply measures to lower the water temperature in winter. As a result of comparing and analyzing the results when the bioreactor was covered and operated, a significant improvement effect occurred. In addition, a plan to improve the treatment efficiency of the bioreactor in winter is to extend the residence time of the bioreactor, a plan to expand the bioreactor specification, a new flow control tank and transport it to the outside, and an oxygen-free air diffuser to be used as an aerobic tank in case of an emergency in winter. The improvement plan was suggested. The results of this study are expected to be used as basic data for the operation plan of small-scale sewage treatment facilities in winter.

In this study, a computational work to investigate the influence of a turbulent wake flow by a rectangular prism with different aspect ratio, which is installed at the inlet of a diffuser. The k-ω model was adopted to simulate the turbulence. The continuity and time averaged Navier-stokes equations were solved by a implicit finite volume scheme. The computational results are qualitatively well compared to existing experimental data by PIV. The results show that the velocity recovery of the subsonic diffuser is dependent on the aspect ratio of rectangular prism.

Approximately a decade has passed since LED lighting became popular, and numerous studies have been conducted on the fires and their causes related to LED lighting. However, research on the combustion characteristics and the risk of combustion expansion according to the material of the external diffuser plate (PC, PMMA, PS) remains insufficient. This study collected 22 types of commercially available diffuser plate samples and conducted re-experiments, TG-DTA, EGA, and FT-IR analysis to investigate the combustion characteristics and the risk of combustion spread to the floor combustibles by the materials. The diffuser plates made of PS, which have the highest risk of combustion expansion, are commonly found in square or rectangular shapes, suggesting they are the most widely distributed in the market. It is noted that if the diffuser plate is made of flame-retardant material like PC, the combustion would be limited to the LED light itself. However, in the case of non-flame-retardant materials like PS, the fire could spread through the floor combustibles and potentially the entire room, which could lead to misjudgment of the fire’s cause. Therefore, it is crucial to strive for the distribution of flame-retardant material diffuser plates.

본 연구에서는 오존공정의 효율적인 설계 및 운영을 목적으로 전달효율을 평가하기 위한 모델을 선정하고, 그 모델식을 오존설비를 운영하고 있는 정수장에 적용하여 운영 조건별 오존전달 효율을 모의하여 분석하였다. 또한 실공정과의 데이터 비교를 통하여 모델의 정확성을 확인하였으며, 데이터의 정확성을 높이기 위해 운영인자(기포지름)를 보정하여 실공정과의 오차를 개선하였다. 시험결과 다양한 운영조건이 오존전달 효율에 영향을 미치고 있었으며, 특히, 산기관의 설치위치 및 수온에 의해 오존전달 효율의 변화가 큰 것으로 조사되었다. 또한 오존전달 모델을 M정수장을 대상으로 모의한 결과 실제 데이터와 유사한 결과를 얻을 수 있었으며, 오차를 최소화하기 위해 기포지름에 보정계수를 반영한 결과와 실공정의 데이터가 매우 비슷한 결과값을 나타내고 있었다.

This studies suggest model for efficient design and operation of the ozone process, that can be acquisition and analysis of real-time data for the ozone transfer efficiency. By using this program, the ozone transfer efficiency is evaluated due to the variety of operating conditions, and these data compared with the current operating process to confirm the accuracy of modeling. Also, the current process errors are improved by compensating the operating parameters of the model such as bubble diameters. In modeling test results, ozone transfer efficient is affected by a variety of operating conditions that are large swings by installation level of the fine diffuser and water temperature among them. And the modeling of M water treatment plant was obtained similar data. In order to minimize data errors, the simulation results, which is reflected the bubble diameter correction factor, were able to obtain very accurate data.

Peoples live the most of the day in an indoor. Therefore, the various technical system is used in order to be agreeable more and efficiently maintain the inner climate. Diffuser is played the important role among the air conditioner and it has enough to note as to a selection. Recently, the predictive assessment of the indoor thermal environment in which we use CFD and air environment is actively made. And the result of being performed by carefully considering the air specific of a diffuser is rare. Therefore, in this, each type of the diffuser for indoor air specific was carefully analyzed. It expects to be used as the boundary condition of a diffuser, when the predictive assessment of the indoors thermal environment and air environment is made by using CFD.

In this study, we have modeled a wide angle diffuser with rectangular prism and tried to investigate the influence of a turbulent wake flow by PIV and a numerical simulation using computational fluid dynamics based on steady-state Navier-Stokes equation and standard k-ε model. A commercial CFD program, FLUENT, is used on the analysis. The turbulent wake is generated by a rectangular prism, which is installed at the diffuser. The results show that it is possible to flow control by installing a rectangular prism within the diffuser and velocity recovery is the highest in aspect ratio 1:1.

In this study, a experimental work to investigate the influence of a turbulent wake flow on the velocity distribution of a diffuser with PIV method. The turbulent wake is generated by a rectangular prism, which is installed at the inlet of a diffuser. The results show that the velocity recovery of the subsonic diffuser is dependent on the height and location of rectangular prism. It is found that a certain height of the rectangular prism to generate the turbulent wake give a better velocity recovery, compared with no rectangular prism.

This study was performed to analyze the effect on driving performance by identifying the flow characteristics of the rear diffuser such as drag coefficient, lift coefficient, velocity vector, velocity streamlines, turbulence kinetic energy and vortex-core region according to the angle of the sedan rear diffuser and the shape of the divider. The angle of the diffuser was analyzed at 2° intervals from 0° to 18°, and the divider was analyzed by changing from one to five. The three-dimensional modeling was performed using CATIA V5 and the vehicle model was selected as a sedan car in the form of an LF Sonata. The CFD analysis was performed in order to identify the flow characteristics of rear diffuser using ANSYS CFX 14.5.7. For each model, the analysis was performed under each condition with speeds of 80km/h, 100km/h, 120km/h, 140km/h. The results of the flow analysis showed that the rear diffuser angle was the best result in driving stability at 6°. The results of the study on the number of dividers showed the best result value in driving stability when the rear diffuser angle was 6° and the divider was 3 and selected as the optimal shape.

In this study, the flow characteristics at the front and the rear side of the diffuser installed in the AHU for Offshore HVAC system were studied. Set up the rectangular prism of which height is H at diffuser inlet duct, the flow control methods were considered using PIV and CFD numerical analysis. Average flow velocity was increased by 37% and the degree of flow uniformity was 96.7% at x/H =1.5.

최근 독거노인과 1인 가구 증가 등 주거 형태 변화 및 미디어 업종의 증가, 전염병 등은 업무형태를 크게 변화시키고 있다. 이로 인해 현대인들의 실내 거주 시간이 늘어나며 실내 공기질 확보에 대한 관심이 늘어나고 있다. 이러한 실내 공기 환경은 외부 요인뿐 아니라 거주자의 생활 패턴의 영향을 크게 받는다. 이에 본 연구에서는 거주 자의 활동 유형을 분석하였으며, 실내 공기질 관리를 위한 최적의 시나리오를 제안하고자 하였다. 이러한 시나리오 계획을 위해 리빙랩에서 생활 활동에 대해 실내 공기질과 생체 활동 신호 분석을 실시하였다. 실험결과를 토대로 가 정 내에서 일어나는 생활 활동을 공기오염도 및 재실자 활동량에 따라 ‘미활동, 비활동, 활동, 주의활동’ 으로 분류하 였다. 따라서 이러한 활동분류로 예측 환기를 진행할 때 실내 공기질의 쾌적함을 관리 할 수 있을 것으로 보인다.

Recent changes in housing types, such as the increase in the elderly living alone and single-person households, as well as an increase in the media industry, and infectious diseases have significantly changed work patterns. As a result, modern people spend more time indoors, and interest in securing IAQ is increasing. This indoor air environment is greatly influenced by the living patterns of residents as well as external factors. Therefore, this study analyzed the types of residents' activities and attempted to propose an optimal scenario for indoor air quality management. In order to plan these scenarios, IAQ and biological activity signal analysis were performed on living activities in the Living Lab. Based on the experimental results, living activities occurring in the home were classified into ‘activity, less activity, proper activity, and caution activity’ according to the air pollution level and the amount of activity. Therefore, it seems that the comfort of indoor air quality can be managed when predictive ventilation is carried out with this activity classification

The purpose of this study is to review the reliability of the CFD. To perform this study, CFD simulations were compared with experimental results based on the performance results of the diffuser line. The results of this study are as follows. 1) Looking at the results of indoor air distribution measurements, Air distribution of indoor through Air of diffuser could judge to be distributed of indoor air evenly. 2) It compared actual data of Cooling experimental and heating experimental with the CFD analysis results. the average error rate of Cooling was 6% and the average error rate of Heating was 6.9%. In air flow case, the air velocity is some different to 0m/s ~ 0.178m/s. Looking at the air flow and the air velocity, two results could judge to be similar to pattern. As a result, the predictions of the indoor thermal and airflow environment through CFD simulation are considered possible.

현대인들은 빠른 생활 속도와 스트레스, 불규칙한 생활 습관으로 인해 정신적, 신체적 건강에 많은 어려 움을 겪고 있다. 아로마테라피는 자연적인 방법으로 심 신의 안정과 치유를 도모하며, 현대인들에게 필요한 휴 식과 회복을 제공하여 일상의 삶에서 중요한 역할을 할 수 있는 대안으로 주목받고 있다. 특히, 아로마 디퓨저는 공기의 질을 개선하고 쾌적 한 환경을 조성하여 기분을 좋게 하고 건강에도 도움이 되므로 전 세계적으로 소비량이 늘어나고 있다. 이와같 이 소비자들의 아로마 디퓨저에 대한 관심과 수요의 급 증에 따라 실용적인 디퓨저 기능과 도구에 관한 발명 디자인과 특허도 중요시되고 있다. 아로마 디퓨저를 통한 아로마테라피의 접근성이 용 이하고 기능적이고 효율적인 요소들이 필요해지면서 보다 높은 효능을 지닌 디퓨저 도구의 개발이 요구되고 있다. 본 연구는 아로마테라피에 사용되는 아로마 디퓨저의 구조를 파악하고 이에 대한 특허 사례분석을 통해 아이디어 적용사례를 분석하며, 신기능 디퓨저 특허 개 발을 통한 아로마테라피 도구의 발명 아이디어 도출에 대해 연구하고자 하였다. 이에 기존 아로마 디퓨저 토출 과정의 단점을 보완 하여 기능성과 편리성을 높인 아로마 디퓨저의 구조에 관한 특허 개발을 진행하였다. 연구의 결과, 기존 제품의 문제점을 파악하여 해결 책으로써 차별화된 효능적인 아이디어에 의한 아로마 디퓨저 구조와 기능을 개발하여 효율성과 편리성을 제 공하는 독창적인 특허 개발 방안을 제시할 수 있었다.

Modern individuals are facing many challenges to their mental and physical health due to the fast pace of life, stress, and irregular lifestyle habits. Aromatherapy is gaining attention as an alternative that promotes mental and physical stability and healing through natural methods, providing the necessary rest and recovery for modern people, and playing an important role in daily life. In particular, aroma diffusers are increasingly consumed worldwide as they improve air quality, create a pleasant environment, enhance mood, and contribute to health. With the surge in consumer interest and demand for aroma diffusers, the invention design and patents related to practical diffuser functions and tools are also becoming important. As the accessibility of aromatherapy through aroma diffusers becomes easier, there is a growing need for functional and efficient elements, leading to the demand for the development of diffusers with higher efficacy. This study aims to understand the structure of aroma diffusers used in aromatherapy, analyze patent cases related to them, and derive inventive ideas for aromatherapy tools through the development of new functional diffuser patents. We conducted patent development on the structure of aroma diffusers that enhance functionality and convenience by addressing the shortcomings of existing aroma diffuser discharge processes. As a result of the research, we were able to identify the problems of existing products and present a unique patent development plan that offers efficiency and convenience through a differentiated and effective idea for the structure and function of aroma diffusers.

향을 이용한 아로마테라피는 고대부터 전 세계적으로 종교적 또는 질병치유 목적으로 사용되어 왔다. 최근에는 많은 사람들이 피부관리, 염증치료 등 치유 목적이외에 정신건강을 위하여 아로마테라피를 사용하고 있다. 많은 아로마테라피 디퓨 저들은 다양한 형태와 소재들이 활용되고 있지만 대부분의 제품은 자연적으로 공기 중에 향을 휘산시키거나 양초 등의 열을 이용한 훈증 방식을 채택하고 있다. 우리나라 분청사기는 전통적, 문화적으로 매우 중요한 위치를 차지하고 있다. 우리는 분청 사기의 디자인, 형태, 문양 등을 발전시키고 새로운 제품에 접목시켜 현대사회의 소비자 요구에 부응하여야 한다. 본 연구의 목적은 분청사기와 아로마 디퓨저를 결합하고 소비자가 제품에 대하여 가지고 있는 감성이미지를 추출하여 소비자를 만족시킬 수 있는 아로마 디퓨저를 개발하는 것이다. 그리고 이를 통하여 전통의 긍정적 이미지와 문화 인프라를 구축하고 전통 도자기 를 고부가가치 산업으로 연계하고자 한다.

Aroma therapy was used for religious or healing purpose in the world throughout the history. In these days, numbers of people use aroma therapy for various reasons such as mental health issue. Aroma diffusers are made with various subjects, but most are made with volatilization and candle by using fumigation method. Korea’s a grayish-blue-powdered celadon has insignificant position in both traditional and cultural value. Grayish-blue-powdered celadon must constantly develop its style and design and collaborate with modern product to meet the demand of the today’s market. In this research, it will find the method to develop an aroma diffuser by using a grayish-blue-powdered celadon to meet consumer’s demand. And ultimately, this research will construct a cultural infrastructure based on traditional image and by adding more value on the traditional ceramics market.

The objective of the work was to study the effect of C/N ratio and type of aeration on nitrification rates of activated sludge by advanced wastewater treatment process. The activated sludge from 26 wastewater treatment plants were collected and grouped through A-H depending upon the type of industry and the C/N ratio. The experiment was carried out in lab-scale (20 liters) and pilot plant scale (8000 liters). For the case of pilot plant scale, two type of aeration were studied namely side aeration and overall aeration. The specific nitrification rate (SNR) was calculated and it was correlated with the C/N ratio and the aeration type. No inverse relation between the C/N ratio and the SNR had been established. This result disagree with the earlier study. The SNR for overall aeration was more compared with side aeration for the same dissolved oxygen level in both type of aeration. The difference between SNR of two different type of aeration was about 8.8%.

In structured light 3D measurement field, when the object has smooth surface, it can form a highlight area due to the specular reflection, and the distortion of the object will make a large measurement error. In order to solve this problem, this paper use seven steps sine-phase shift combined with linear diffuser to remove highlight. Firstly, the principle of removing specular with diffuser is analyzed, then the overall design of the system is introduced, which includes 3D reconstruction and system calibration method. Finally the reconstructed experiments are carried out with ceramic plate. Experimental results show that the proposed method can significantly reduce the highlights area of reconstructed image compared with the highlights area without diffuser. The diffuser can obviously inhibited by highlights, although it can not completely remove the highlights, it plays a very important role in reconstructing specular object with more accurate and better quality.