• Title/Summary/Keyword: Phase Balance

Search Result 519, Processing Time 0.024 seconds

A Theoretical Approach on the Pressure Drop in Two-phase Particle-laden Flows (고체입자가 부상된 이상유동에서 압력강하에 대한 해석적 접근)

  • Kim Seyun;Lee Kye-Bock
    • Journal of Energy Engineering
    • /
    • v.14 no.1
    • /
    • pp.11-17
    • /
    • 2005
  • The purpose of this research is to develop the model of pressure drop per unit pipe length due to the turbulence modulations in particle-laden flows which can be applied to various fluid conditions. The wake behind a particle, particle size, loading ratio and density difference between two phases of particle-laden flow was considered. The frictional pressure drop was modeled with the force balance in control volume. The numerical results show good agreements with available experimental data and the model success-fully predicted the mechanism of the pressure drop in particle-laden flows.

Evaluation of Gait Stability using Medio-Lateral Inclination Angle in Male Adults (좌·우 기울기각도를 이용한 남자 성인의 보행안정성 평가)

  • Chang, Jae-Kwan;Yoon, Suk-Hoon
    • Korean Journal of Applied Biomechanics
    • /
    • v.20 no.3
    • /
    • pp.261-266
    • /
    • 2010
  • Human body is hard to be in perfect balance during walking. Most of time the trunk is supported by one leg and the center of mass(COM) falls to the contralateral side. Thus, dynamic variables such as the velocity of the COM should be considered when gait stability is evaluated. The purpose of this study was to investigate whether the extrapolated center of mass(XCom) which utilized the COM position and its velocity, is appropriate to evaluate gait stability. Ten healthy adults participated in this study and performed 3 different types of gaits(normal(NG), hands on waists(HWG), and hands on shoulders(HSG)) onto 4 different types of obstacle(obstacle height: 0%, 30%, 40% and 50% of leg length). Medio-lateral Com-CoP and XCom-CoP inclination angle were calculated during support phase. For all condition, greater M-L XCoM-CoP inclination angles were found(p<.05) compared with those of matched obstacle height CoM-CoP. Especially, M-L XCoM-CoP inclination angle at 50% height revealed the best condition for monitoring dynamic stability. Significantly increased in M-L XCoM-CoP inclination angle was found(p<.05) as obstacle height increased on NG and HWG.

Clinical Experiment Results of Cerec Inlab using Vita9 (VITA VM9 Zirconia powder를 이용한 Cerec inlab의 임상증례에 관하여)

  • Jung, Hyo-Kyung;kim, Jeong-Sook;Lee, Jong-Do
    • Journal of Technologic Dentistry
    • /
    • v.29 no.2
    • /
    • pp.119-128
    • /
    • 2007
  • Although there are many different ways that restorations can be made, it can be said that the biocompatibility of abutment and crown is very important in this experiment. When placed in the actual oral cavity, the differences were obvious. Compared to In-ceram Aluminium, the structure that is obtained after firing reveals a particularly homogeneous distribution of the crystal and glass phase. The In-ceram aluminium system had many problems, such as having weak tensile strength, and having low bonding strength due to the shrinking that occurs after firing. Because of the opaque finish of the metal frame, the two may look similar from the outside, but it is evident that there are differences between using a metal frame and In-ceram. VITA VM9 has been designed as a special ceramic featuring a fine structure or stabilized Zro2 substructures, and so the VITA VM9 excels in its light refraction and reflection behavior, which is similar to natural teeth. It also has outstanding chemical balance, which presents advantages such as considerably reduced accumulation of plaque on the ceramic surface.? This ultimately results in easier care and cleaning for the patient.

  • PDF

TRAIL and Bortezomib: Killing Cancer with Two Stones

  • Qureshi, Muhammad Zahid;Romero, Mirna Azalea;Attar, Rukset;Javed, Zeeshan;Farooqi, Ammad Ahmad
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.16 no.4
    • /
    • pp.1671-1674
    • /
    • 2015
  • Cancer genomics and proteomics have undergone considerable broadening in the past decades and increasingly it is being realized that solid/liquid phase microarrays and high-throughput resequencing have provided platforms to improve our existing knowledge of determinants of cancer development, progression and survival. Loss of apoptosis is a widely and deeply studied process and different approaches are being used to restore apoptosis in resistant cancer phenotype. Modulating the balance between pro-apoptotic and anti-apoptotic proteins is essential to induce apoptosis. It is becoming more understood that pharmacological inhibition of the proteasome might prove to be an effective option in improving TRAIL induced apoptosis in cancer cells. Keeping in view rapidly accumulating evidence of carcinogenesis, metastasis, resistance against wide ranging therapeutics and loss of apoptosis, better knowledge regarding tumor suppressors, oncogenes, pro-apoptotic and anti-apotptic proteins will be helpful in translating the findings from benchtop to bedside.

Adaptation Experience of Living Kidney Donors after Donation (생체 신장 공여자의 공여 후 적응 경험)

  • Kang, Da-Hai-Som;Yang, Jinhyang
    • Journal of Korean Academy of Nursing
    • /
    • v.46 no.2
    • /
    • pp.271-282
    • /
    • 2016
  • Purpose: This study was done to explore adaptation experience of living kidney donors after donation. Specific aims were to identify challenges donors face in the process of adaptation following surgery and how they interact with recipients and other people. Methods: Grounded theory methodology was utilized. Participants were 13 living kidney donors at six months or more after donation. Data were collected by in-depth interviews with individual participants. Data were analyzed using constants comparative method with theoretical saturation. Results: A core category emerged as 'keeping the fences of my family in spite of vulnerability'. The adaptation process after donation was manifested in four phases: exploration, balance, maintenance, and acclimatization. Phenomenon was perception of vulnerability. Strategies to manage the vulnerability were assessing changes of body awareness, tailoring regimen to one's own body condition, coping with health problems, keeping restoration of health, and ruminating on the meaning of one's kidney donation. Consequences were reestablishing family well-being, realizing the values of one's kidney donation, and living with uncertainty. Conclusion: Findings of the study indicate that there is a need for health professionals to understand the vulnerability of living kidney donors and help their family system maintain a healthy and productive life. The results of this study can be used to develop phase-specific, patient-centered, and tailored interventions for living kidney donors.

Design of an Asymmetrical Three-phase Inverter for Load Balancing and Power Factor Correction Based on Power Analysis

  • Mokhtari, M.;Golshannavaz, S.;Nazarpour, D.;Aminifar, F.
    • Journal of Electrical Engineering and Technology
    • /
    • v.6 no.3
    • /
    • pp.293-301
    • /
    • 2011
  • This paper presents a novel theoretical method based on power analysis to obtain voltage reference values for an inverter-based compensator. This type of compensator, which is installed in parallel with the load, is usually referred to as the active filter. The proposed method is tailored to design the compensator in such a way that it can simultaneously balance the asymmetric load, as well as correct the power factor of the supply side. For clarity, a static compensator is first considered and a recursive algorithm is utilized to calculate the reactance values. The algorithm is then extended to calculate voltage reference values when the compensator is inverter based. It is evident that the compensator would be asymmetric since the load is unbalanced. The salient feature associated with the proposed method is that the circuit representation of system load is not required and that the load is recognized just by its active and reactive consumptions. Hence, the type and connection of load do not matter. The validity and performance of the new approach are analyzed via a numerical example, and the obtained results are thoroughly discussed.

Effects of Task-Specific Obstacle Crossing Training on Functional Gait Capability in Patients with Cerebellar Ataxia: Feasibility Study

  • Park, Jin-Hoon
    • The Journal of Korean Physical Therapy
    • /
    • v.27 no.2
    • /
    • pp.112-117
    • /
    • 2015
  • Purpose: The purpose of this study was to examine the effects of a task-specific obstacle crossing rehabilitation program on functional gait ability in patients with cerebellar ataxia. Overall, we sought to provide ataxia-specific locomotor rehabilitation guidelines for use in clinical practice based on quantitative evidence using relevant analysis of gait kinematics including valid clinical tests. Methods: Patients with cerebellar disease (n=13) participated in obstacle crossing training focusing on maintenance of dynamic balance and posture, stable transferring of body weight, and production of coordinated limb movements for 8 weeks, 2 times per week, 90 minutes per session. Throughout the training of body weight transfer, the instructions emphasized conscious perception and control of the center of body stability, trunk and limb alignment, and stepping kinematics during the practice of each walking phase. Results: According to the results, compared with pre-training data, foot clearance, pre-&post-obstacle distance, delay time, and total obstacle crossing time were increased after intervention. In addition, body COM measures indicated that body sway and movement variability, therefore posture stability during obstacle crossing, showed improvement after training. Based on these results, body sway was reduced and stepping pattern became more consistent during obstacle crossing gait after participation in patients with cerebellar ataxia. Conclusion: Findings of this study suggest that task-relevant obstacle crossing training may have a beneficial effect on recovery of functional gait ability in patients with cerebellar disease.

Effects of Warm-up Performance on SI Engine with Exhaust Heat Recovery System (배기열 회수장치 적용에 따른 SI 엔진의 웜업 성능에 미치는 영향)

  • Park, Kyoun-Suk;Suh, Ho-Cheol;Park, Sun-Hong;Kim, In-Tae;Jang, Sung-Wook
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.19 no.6
    • /
    • pp.53-60
    • /
    • 2011
  • The effect of exhaust heat recovery system can be evaluated by two well known method. First method is to measure the time duration from engine start under cold coolant temperature till coolant get warmed. By this methodology coolant warming duration can be index of warm-up effect. Second method is to analyze heat balance of the engine during warm-up phase under steady engine operation so that wasted energy by losses such as cooling and exhaust can be index of warm-up effect. This study focused on evaluation of warming-up effect by both methodology above mentioned using 2L SI engine under from idle to 2000rpm steady condition. Results, idle operation showed low heat recovery efficiency but under higher engine speed condition, remarkable heat recovery efficiency improvement was observed. In 2000rpm steady condition, warm-up duration of engine is decreased by exhaust heat recovery system.

Development of Simulator for Evaluation Balance by Using Vestibuloocular Reflex (전정안구반사를 이용한 평형감각 평가용 시뮬레이터의 개발)

  • 임승관;김규겸;정호춘;진달복;김민선;박병림
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
    • /
    • 1997.11a
    • /
    • pp.157-162
    • /
    • 1997
  • The purpose of this study was to develop a sinusoidal rotatory chair systim for evaluating the vestibular function in patients suffered from vertigo with vestibualr disorders. The sinusoidal rotatory chair system is composed of a rotatory chair systim and softwares. Maximum velocity of the rotatiry chair was upto 60 degree per second and frequency range was 0.01 to 0.64 Hz. To evaluate the vestibular function in vertigo patients, vestibuloocular reflex was measured by sinusoidal rotation of the whole body about vertical axis in the darkness, and optokinetic nystagmus, visual vestibuloocular reflex , and visual supression test were also performed. Eye movement was measured by means of a electronystgmograph amplifier through Ag-AgCI surface electrodes. Gain, phase, and symmetry were obtained from analysis of the eye movement ineuced by vestibular or visual stimulation. In healthy adults, sinusoidal rotation of the shole body produced nystagmus, of which gain was directly proportional to the velocity of stimulation. The gain of visual vestibuloocular reflex or optokinetic nystagmus, and it was suppressed markedly by visual suppression test. These results suggest that the sinusoieal rotatory chair systim which was developed by this study can evaluate the vestibular function quantitatively, also this system is very useful to diagnose and to dstimate the vestibualr function during recovery from vertigo

  • PDF

Design and Performance Evaluation for a Fuel Cell/Battery Hybrid Mini-Bus Based on a Simulation (시뮬레이션 기반 연료전지/2차전지 하이브리드 미니버스의 설계 및 성능 평가)

  • Kim, Min-Jin;Kong, Nak-Won;Lee, Won-Yong;Kim, Chang-Soo
    • Journal of Hydrogen and New Energy
    • /
    • v.18 no.1
    • /
    • pp.60-66
    • /
    • 2007
  • In terms of the vehicle efficiency, a fuel cell hybrid system has advantages compared to a conventional internal combustion engine and a fuel cell alone-powered system. The efficiency of the fuel cell hybrid vehicle mainly depends on the maximum power of the fuel cell and therefore it is important to decide the design value of the fuel cell maximum power. In this paper, to estimate the performance of the fuel cell hybrid mini-bus in the design phase the simulator based on the models for the fuel cell stack, the electric battery, the fuel cell balance of plant, the controller, and the vehicle itself is proposed. Additionally, the hybrid mini-bus efficiencies with several different fuel cell powers are simulated for a city driving schedule and are compared on another. Consequently, the proposed simulation scheme is useful to determine the best design value of the fuel cell hybrid vehicles.