• Title/Summary/Keyword: Energy balance approach

Search Result 127, Processing Time 0.03 seconds

Nursing approach to energy (Qi) flow (에너지 흐름(기(氣))의 간호학적 접근)

  • Kim, Myung-Ja;Lee, Myung-Suk
    • Journal of East-West Nursing Research
    • /
    • v.3 no.1
    • /
    • pp.7-16
    • /
    • 1998
  • This paper reviewed the concept of the energy flow in east and west. The differences in the views of the energy flow between oriental and western thought were compaired according to the ontological point of view. Human body take up energy and material on open system which maintains homeostasis. Human and environment are continuously interacting in a state of co-existence. Human has energy field called "aura" and seven chakra in energy outflow moving came as meridian. Qi is an invisible cosmic energy helping the fundamental human activity and changes. The basic action of Qi is helping the human growth and development, maintain the body temperature and preventing the intrusion of microorganism. In the normal healthy organism, all are maintained in balance and in a continuous circulation of Qi, while illness is the result of the disturbed Qi flow in the aspect of Qi-theory. Although there are differences between oriental and western medicine in approaches to clients, the basic point of view and philosophy have many similarities on fundamental level. An understanding of the basic thought of energy flow and oriental concept of energy flow implies a more comprehensive meaning than the perspective of unitary transformation discussed in modern western thought of energy flow. Now we should avoid narrow view of energy concept and regard energy flow as an integrated concept with Korean culture. Regarding Qi-theory which provides a comprehensive and humanistic and ethical foundation for nursing philisophy through this overview, it is hoped that a contribution will be made to the development of nursing intervention which is suitable to Korean context.

  • PDF

Simple Design Method of the Engine Enclosure Considering Cooling and Noise Reduction (냉각과 소음을 고려한 엔진 차폐 구조의 간편한 설계 방법)

  • 최재웅;김관엽;이희준
    • Journal of KSNVE
    • /
    • v.9 no.1
    • /
    • pp.184-188
    • /
    • 1999
  • Noise regulation of heavy construction machinery is getting stricter: 3 dB per every 4 year in European community. To meet this requirement many engineers have adopted the enclosing structures with thick absorbing materials and small opening, This increases internal temperature of the enclosure which have engine systems such as electric equipment that are vulnerable to heat, and engine block and muffler that can be regarded as heat sources. So noise control engineers have to consider a coupling problem: combining heat balance and noise reduction. This paper describes this approach by introducing simple heat transfer theory and SEA. The enclosing system of the loader whose enclosing structure consists of two rooms is investigated to show the validity of this method. The results represent that the simple heat transfer theory can be useful to estimate cooling performance when it is linked together by the back pressure theory in duct system. and the radiated noise can also be estimated by the SEA. Therefore a designer can use these approaches to define the opening ratio of an enclosure and the mass flow rate of air considering radiating noise.

  • PDF

Design of Ultra-sonication Pre-Treatment System for Microalgae CELL Wall Degradation

  • Yang, Seungyoun;Mariappan, Vinayagam;Won, Dong Chan;Ann, Myungsuk;Lee, Sung Hwa
    • International journal of advanced smart convergence
    • /
    • v.5 no.2
    • /
    • pp.18-23
    • /
    • 2016
  • Cell walls of microalgae consist of a polysaccharide and glycoprotein matrix providing the cells with a formidable defense against its environment. Anaerobic digestion (AD) of microalgae is primarily inhibited by the chemical composition of their cell walls containing biopolymers able to resist bacterial degradation. Adoption of pre-treatments such as thermal, thermal hydrolysis, ultrasound and enzymatic hydrolysis have the potential to remove these inhibitory compounds and enhance biogas yields by degrading the cell wall, and releasing the intracellular algogenic organic matter (AOM). This paper preproposal stage investigated the effect of different pre-treatments on microalgae cell wall, and their impact on the quantity of soluble biomass released in the media and thus on the digestion process yields. This Paper present optimum approach to degradation of the cell wall by ultra-sonication with practical design specification parameter for ultrasound based pretreatment system. As a result of this paper presents, a microalgae system in a wastewater treatment flowsheet for residual nutrient uptake can be justified by processing the waste biomass for energy recovery. As a conclusion on this result, Low energy harvesting technologies and pre-treatment of the algal biomass are required to improve the overall energy balance of this integrated system.

A Study on the Sustainable Characteristics of Sustainable Architectural Space viewed in the Eco-Aesthetic perspective - Focusing on korean traditional residential space - (생태 미학적 관점에서 본 지속가능한 건축 공간 특성에 관한 연구 - 한국 전통 주거 공간을 중심으로 -)

  • Yang, Eun-Ji;Kim, Kai-Chun
    • Korean Institute of Interior Design Journal
    • /
    • v.21 no.4
    • /
    • pp.31-39
    • /
    • 2012
  • Ecosystem and environment have been a serious challenge facing the modern society. It's been the new paradigm from ecological view of the world and the alternative based on Orientalism. From the Oriental standpoint, ecological aesthetics and sustainable architecture are no longer new, which then servers the background of this study. The nature and the space, the life where the human is harmonized and integrated and the wish to make the balance through that life are the basic philosophy which the Orientalism has pursued. Based on such a basic concept, the study is intended to review the connectivity, expression approach and the features in Korean traditional residential space based on previous studies on ecological aesthetics and sustainable architecture. Such attempt is meaningful in seeking the possibility of presenting the new frame as well as forming the various views to the traditional space and spatial recognition. The nature was categorized into tangible element and intangible element and also direct approach and indirect approach before evaluating the characteristics. Sustainable architecture is not the concept to simply maintain or sustain the environment, but plays more important role in economical aspect. Traditional space accommodates the nature and circulation principle and the circulation in the nature controls the energy and enhances the efficiency, playing significant role. The nature itself serves the alternative energy and has the aesthetic element in such a way of concealing itself. This study is intended to analyze the Byulseo Jeongwon which formed many relations with the nature and the residential space, thereby identifying the expression characteristics of eco-aesthetic sustainable architect. This study offers the answers with regard to the coexistence of the expression characteristics of sustainable architecture with the nature, space and the human from eco aesthetic viewpoint as well as the solution in dealing with the ecological and environmental challenges. Furthermore, it suggested the possibility that the traditional space would possibly be succeedable in new and creative way and sought the way for coexistence among the nature, space and human and eco aesthetics, and finally paved the pivotal foundation as the sustainable design alternative in future.

  • PDF

Assessing the resilience of urban water management to climate change

  • James A. Griffiths
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2023.05a
    • /
    • pp.32-32
    • /
    • 2023
  • Incidences of urban flood and extreme heat waves (due to the urban heat island effect) are expected to increase in New Zealand under future climate change (IPCC 2022; MfE 2020). Increasingly, the mitigation of such events will depend on the resilience of a range Nature-Based Solutions (NBS) used in Sustainable Urban Drainage Schemes (SUDS), or Water Sensitive Urban Design (WSUD) (Jamei and Tapper 2019; Johnson et al 2021). Understanding the impact of changing precipitation and temperature regimes due climate change is therefore critical to the long-term resilience of such urban infrastructure and design. Cuthbert et al (2022) have assessed the trade-offs between the water retention and cooling benefits of different urban greening methods (such as WSUD) relative to global location and climate. Using the Budyko water-energy balance framework (Budyko 1974), they demonstrated that the potential for water infiltration and storage (thus flood mitigation) was greater where potential evaporation is high relative to precipitation. Similarly, they found that the potential for mitigation of drought conditions was greater in cooler environments. Subsequently, Jaramillo et al. (2022) have illustrated the locations worldwide that will deviate from their current Budyko curve characteristic under climate change scenarios, as the relationship between actual evapotranspiration (AET) and potential evapotranspiration (PET) changes relative to precipitation. Using the above approach we assess the impact of future climate change on the urban water-energy balance in three contrasting New Zealand cities (Auckland, Wellington, Christchurch and Invercargill). The variation in Budyko curve characteristics is then used to describe expected changes in water storage and cooling potential in each urban area as a result of climate change. The implications of the results are then considered with respect to existing WSUD guidelines according to both the current and future climate in each location. It was concluded that calculation of Budyko curve deviation due to climate change could be calculated for any location and land-use type combination in New Zealand and could therefore be used to advance the general understanding of climate change impacts. Moreover, the approach could be used to better define the concept of urban infrastructure resilience and contribute to a better understanding of Budyko curve dynamics under climate change (questions raised by Berghuijs et al 2020)). Whilst this knowledge will assist in implementation of national climate change adaptation (MfE, 2022; UNEP, 2022) and improve climate resilience in urban areas in New Zealand, the approach could be repeated for any global location for which present and future mean precipitation and temperature conditions are known.

  • PDF

A DYNAMIC SIMULATION OF THE SULFURIC ACID DECOMPOSITION PROCESS IN A SULFUR-IODINE NUCLEAR HYDROGEN PRODUCTION PLANT

  • Shin, Young-Joon;Chang, Ji-Woon;Kim, Ji-Hwan;Park, Byung-Heung;Lee, Ki-Young;Lee, Won-Jae;Chang, Jong-Hwa
    • Nuclear Engineering and Technology
    • /
    • v.41 no.6
    • /
    • pp.831-840
    • /
    • 2009
  • In order to evaluate the start-up behavior and to identify, through abnormal operation occurrences, the transient behaviors of the Sulfur Iodine(SI) process, which is a nuclear hydrogen process that is coupled to a Very High Temperature Gas Cooled Reactor (VHTR) through an Intermediate Heat Exchanger (IHX), a dynamic simulation of the process is necessary. Perturbation of the flow rate or temperature in the inlet streams may result in various transient states. An understanding of the dynamic behavior due to these factors is able to support the conceptual design of the secondary helium loop system associated with a hydrogen production plant. Based on the mass and energy balance sheets of an electrodialysis-embedded SI process equivalent to a 200 $MW_{th}$ VHTR and a considerable thermal pathway between the SI process and the VHTR system, a dynamic simulation of the SI process was carried out for a sulfuric acid decomposition process (Second Section) that is composed of a sulfuric acid vaporizer, a sulfuric acid decomposer, and a sulfur trioxide decomposer. The dynamic behaviors of these integrated reactors according to several anticipated scenarios are evaluated and the dominant and mild factors are observed. As for the results of the simulation, all the reactors in the sulfuric acid decomposition process approach a steady state at the same time. Temperature control of the inlet helium is strictly required rather than the flow rate control of the inlet helium to keep the steady state condition in the Second Section. On the other hand, it was revealed that the changes of the inlet helium operation conditions make a great impact on the performances of $SO_3$ and $H_2SO_4$ decomposers, but no effect on the performance of the $H_2SO_4$ vaporizer.

Process fault diagnostics using the integrated graph model

  • Yoon, Yeo-Hong;Nam, Dong-Soo;Jeong, Chang-Wook;Yoon, En-Sup
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1991.10b
    • /
    • pp.1705-1711
    • /
    • 1991
  • On-line fault detection and diagnosis has an increasing interest in a chemical process industry, especially for a process control and automation. The chemical process needs an intelligent operation-aided workstation which can do such tasks as process monitoring, fault detection, fault diagnosis and action guidance in semiautomatic mode. These tasks can increase the performance of a process operation and give merits in economics, safety and reliability. Aiming these tasks, series of researches have been done in our lab. Main results from these researches are building appropriate knowledge representation models and a diagnosis mechanism for fault detection and diagnosis in a chemical process. The knowledge representation schemes developed in our previous research, the symptom tree model and the fault-consequence digraph, showed the effectiveness and the usefulness in a real-time application, of the process diagnosis, especially in large and complex plants. However in our previous approach, the diagnosis speed is its demerit in spite of its merits of high resolution, mainly due to using two knowledge models complementarily. In our current study, new knowledge representation scheme is developed which integrates the previous two knowledge models, the symptom tree and the fault-consequence digraph, into one. This new model is constructed using a material balance, energy balance, momentum balance and equipment constraints. Controller related constraints are included in this new model, which possesses merits of the two previous models. This new integrated model will be tested and verified by the real-time application in a BTX process or a crude unit process. The reliability and flexibility will be greatly enhanced compared to the previous model in spite of the low diagnosis speed. Nexpert Object for the expert system shell and SUN4 workstation for the hardware platform are used. TCP/IP for a communication protocol and interfacing to a dynamic simulator, SPEEDUP, for a dynamic data generation are being studied.

  • PDF

Numerical Study on Pulverized Coal Combustion Applying Two-Phase WSGGM (이상 회체가스 가중합산모델을 적용한 미분탄 연소의 수치적 연구)

  • Yu, Myoung-Jong;Kang, Shin-Jae;Baek, Seung-Wook
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.24 no.10
    • /
    • pp.1368-1379
    • /
    • 2000
  • A numerical study on swirling pulverized coal combustion in an axisymmetric enclosure is carried out by applying the 2-phase weighted sum of gray gases model (WSGGM) approach with the discrete ordinate method (DOM) to model the radiative heat transfer equation. In the radiative transfer equation, the same polynomial equation and coefficients for weighting factors as those for gas are adopted for the coal/char particles as a function of partial pressure and particle temperature. The Eulerian balance equations for mass, momentum, energy, and species mass fractions are adopted with the standard and RNG k-${\varepsilon}$ turbulence model, whereas the Lagrangian approach is used for the particulate phase. The eddy-dissipation model is employed for the reaction rate for gaseous mixture, and the single-step and two-step first-order reaction model for the devolatilization process for coal. Special attention is given to establish the thermal boundary conditions on radiative transfer equation By comparing the numerical results with experimental ones, the radiation model used here is confirmed and found to provide an alternative for simulating the radiative transfer.

Dynamic Effects of Bouncing Water Droplets on Superhydrophobic Tungsten Oxide nanowire surfaces

  • Gwak, Geun-Jae;Lee, Mi-Gyeong;Yong, Gi-Jung
    • Proceedings of the Materials Research Society of Korea Conference
    • /
    • 2009.11a
    • /
    • pp.25.1-25.1
    • /
    • 2009
  • The effects of surface energyon the wetting transition for impinging water droplets were experimentally investigated on the chemically modified WOx nanowire surfaces. We could modify the surface energy of the nanostructures through chemisorption of alkyltrichlorosilanes with various carbon chain lengths and by the UV-enhanced decomposition of self assembled monolayer (SAM) molecules chemically adsorbedon the array. Three surface wetting states could be identified through the balance between antiwetting and wetting pressures. This approach establishes simple strategy for the design criteria for water-repellent surface to impinging droplets.

  • PDF

Modeling of Metal Transfer in GMA Welding Process (용융부의 형상을 고려한 GMA 용접 공정의 금속이행 모델링)

  • 이강희;최상균;유중돈
    • Journal of Welding and Joining
    • /
    • v.13 no.2
    • /
    • pp.115-121
    • /
    • 1995
  • As the metal transfer in the GMAW process affects the weld quality and productivity, the mechanism of molten formation and detachment has been investigated at various welding conditions. The force balance and pinch instability models have been widely used to analyze the metal transfer in the globular and spray modes, respectively A new approach is proposed in this work by minimizing the energy of molten drop system. Effects of the surface tension, gravity, electromagnetic and drag forces are considered with no presumed molten drop geometry. Effects of various welding conditions on the metal transfer are explained. The results show that the proposed mode can be applied to the globular and spray transfer modes. When compared with other models, results of the proposed model show better agreements with the available experimental data, which demonstrates the validity of the present model.

  • PDF