WorldWideScience

Sample records for controlled volumetric heating

  1. Coolability of volumetrically heated particle beds

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Muhammad

    2017-03-22

    In case of a severe nuclear reactor accident, with loss of coolant, a particle bed may be formed from the fragmentation of the molten core in the residual water at different stages of the accident. To avoid further propagation of the accident and maintain the integrity of the reactor pressure vessel, the decay heat of the particle bed must be removed. To better understand the various thermo-hydraulic processes within such heat-generating particle beds, the existing DEBRIS test facility at IKE has been modified to be able to perform novel boiling, dryout and quenching experiments. The essential experimental data includes the pressure gradients measured by 8 differential pressure transducers along the bed height as a function of liquid and vapour superficial velocities, the determination of local dryout heat fluxes for different system pressures as well as the local temperature distribution measured by a set of 51 thermocouples installed inside the particle bed. The experiments were carried out for two different particle beds: a polydispersed particle bed which consisted of stainless steel balls (2 mm, 3 mm and 6 mm diameters) and an irregular particle bed which consisted of a mixture of steel balls (3 mm and 6 mm) and irregularly shaped Al{sub 2}O{sub 3} particles. Additionally, all experiments were carried out for different flow conditions, such as the reference case of passive 1D top-flooding, 1D bottom flooding (driven by external pumps and different downcomer configurations) and 2D top-/bottom-/lateral flooding with a perforated downcomer. In this work, it has been observed that for both particle beds with downcomer configurations an open downcomer leads to the best coolability (dryout heat flux = 1560 kW/m{sup 2}, polydispersed particle bed, psys = 1 bar) of the particle bed, mainly due to bottom-flow with enhanced natural convection. It has also been shown that a potential lateral flow via a perforation of the downcomer does not bring any further improvements

  2. Analytical solution to laser short-pulse heating of microsized metal wire: volumetric and surface heat source considerations

    National Research Council Canada - National Science Library

    Yilbas, B.S; Al-Dweik, A.Y

    2012-01-01

    .... The volumetric heat source resembles absorption by irradiated field according to Lambert’s Beer law while a surface heat source represents short pulse heating through high intensity thermal contact at the surface...

  3. A novel cortical thickness estimation method based on volumetric Laplace-Beltrami operator and heat kernel.

    Science.gov (United States)

    Wang, Gang; Zhang, Xiaofeng; Su, Qingtang; Shi, Jie; Caselli, Richard J; Wang, Yalin

    2015-05-01

    Cortical thickness estimation in magnetic resonance imaging (MRI) is an important technique for research on brain development and neurodegenerative diseases. This paper presents a heat kernel based cortical thickness estimation algorithm, which is driven by the graph spectrum and the heat kernel theory, to capture the gray matter geometry information from the in vivo brain magnetic resonance (MR) images. First, we construct a tetrahedral mesh that matches the MR images and reflects the inherent geometric characteristics. Second, the harmonic field is computed by the volumetric Laplace-Beltrami operator and the direction of the steamline is obtained by tracing the maximum heat transfer probability based on the heat kernel diffusion. Thereby we can calculate the cortical thickness information between the point on the pial and white matter surfaces. The new method relies on intrinsic brain geometry structure and the computation is robust and accurate. To validate our algorithm, we apply it to study the thickness differences associated with Alzheimer's disease (AD) and mild cognitive impairment (MCI) on the Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset. Our preliminary experimental results on 151 subjects (51 AD, 45 MCI, 55 controls) show that the new algorithm may successfully detect statistically significant difference among patients of AD, MCI and healthy control subjects. Our computational framework is efficient and very general. It has the potential to be used for thickness estimation on any biological structures with clearly defined inner and outer surfaces. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Simulation of parameters of hydraulic drive with volumetric type controller

    Science.gov (United States)

    Mulyukin, V. L.; Boldyrev, A. V.; Karelin, D. L.; Belousov, A. M.

    2017-09-01

    The article presents a mathematical model of volumetric type hydraulic drive controller that allows to calculate the parameters of forward and reverse motion. According to the results of simulation static characteristics of rod’s speed and the force of the hydraulic cylinder rod were built and the influence of the angle of swash plate of the controller at the characteristics profile is shown. The results analysis showed that the proposed controller allows steplessly adjust the speed□ц of hydraulic cylinder’s rod motion and the force developed on the rod without the use of flow throttling.

  5. Study of Volumetrically Heated Ultra-High Energy Density Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Rocca, Jorge J. [Colorado State Univ., Fort Collins, CO (United States)

    2016-10-27

    Heating dense matter to millions of degrees is important for applications, but requires complex and expensive methods. The major goal of the project was to demonstrate using a compact laser the creation of a new ultra-high energy density plasma regime characterized by simultaneous extremely high temperature and high density, and to study it combining experimental measurements and advanced simulations. We have demonstrated that trapping of intense femtosecond laser pulses deep within ordered nanowire arrays can heat near solid density matter into a new ultra hot plasma regime. Extreme electron densities, and temperatures of several tens of million degrees were achieved using laser pulses of only 0.5 J energy from a compact laser. Our x-ray spectra and simulations showed that extremely highly ionized plasma volumes several micrometers in depth are generated by irradiation of gold and Nickel nanowire arrays with femtosecond laser pulses of relativistic intensities. We obtained extraordinarily high degrees of ionization (e.g. we peeled 52 electrons from gold atoms, and up to 26 electrons from nickel atoms). In the process we generated Gigabar pressures only exceeded in the central hot spot of highly compressed thermonuclear fusion plasmas.. The plasma created after the dissolved wires expand, collide, and thermalize, is computed to have a thermal energy density of 0.3 GJ cm-3 and a pressure of 1-2 Gigabar. These are pressures only exceeded in highly compressed thermonuclear fusion plasmas. Scaling these results to higher laser intensities promises to create plasmas with temperatures and pressures exceeding those in the center of the sun.

  6. Transient thermal camouflage and heat signature control

    Science.gov (United States)

    Yang, Tian-Zhi; Su, Yishu; Xu, Weikai; Yang, Xiao-Dong

    2016-09-01

    Thermal metamaterials have been proposed to manipulate heat flux as a new way to cloak or camouflage objects in the infrared world. To date, however, thermal metamaterials only operate in the steady-state and exhibit detectable, transient heat signatures. In this letter, the theoretical basis for a thermal camouflaging technique with controlled transient diffusion is presented. This technique renders an object invisible in real time. More importantly, the thermal camouflaging device instantaneously generates a pre-designed heat signature and behaves as a perfect thermal illusion device. A metamaterial coating with homogeneous and isotropic thermal conductivity, density, and volumetric heat capacity was fabricated and very good camouflaging performance was achieved.

  7. Integral transform solution of natural convection in a square cavity with volumetric heat generation

    Directory of Open Access Journals (Sweden)

    C. An

    2013-12-01

    Full Text Available The generalized integral transform technique (GITT is employed to obtain a hybrid numerical-analytical solution of natural convection in a cavity with volumetric heat generation. The hybrid nature of this approach allows for the establishment of benchmark results in the solution of non-linear partial differential equation systems, including the coupled set of heat and fluid flow equations that govern the steady natural convection problem under consideration. Through performing the GITT, the resulting transformed ODE system is then numerically solved by making use of the subroutine DBVPFD from the IMSL Library. Therefore, numerical results under user prescribed accuracy are obtained for different values of Rayleigh numbers, and the convergence behavior of the proposed eigenfunction expansions is illustrated. Critical comparisons against solutions produced by ANSYS CFX 12.0 are then conducted, which demonstrate excellent agreement. Several sets of reference results for natural convection with volumetric heat generation in a bi-dimensional square cavity are also provided for future verification of numerical results obtained by other researchers.

  8. Control and design of volumetric composition in pultruded hybrid fibre composites

    DEFF Research Database (Denmark)

    Madsen, Bo; Hashemi, Fariborz; Tahir, Paridah

    2016-01-01

    Hybrid composites consist of two of more fibre phases in a common matrix phase. This is a challenge for the control and design of the volumetric composition and microstructural uniformity of such composites. In the present study, a model is presented for the prediction of the complete volumetric ...... fibre weight mixing ratios. To demonstrate the suitability of the model, simulations are performed for four different cases of volumetric composition in hybrid kenaf/glass composites....

  9. Point, surface and volumetric heat sources in the thermal modelling of selective laser melting

    Science.gov (United States)

    Yang, Yabin; Ayas, Can

    2017-10-01

    Selective laser melting (SLM) is a powder based additive manufacturing technique suitable for producing high precision metal parts. However, distortions and residual stresses within products arise during SLM because of the high temperature gradients created by the laser heating. Residual stresses limit the load resistance of the product and may even lead to fracture during the built process. It is therefore of paramount importance to predict the level of part distortion and residual stress as a function of SLM process parameters which requires a reliable thermal modelling of the SLM process. Consequently, a key question arises which is how to describe the laser source appropriately. Reasonable simplification of the laser representation is crucial for the computational efficiency of the thermal model of the SLM process. In this paper, first a semi-analytical thermal modelling approach is described. Subsequently, the laser heating is modelled using point, surface and volumetric sources, in order to compare the influence of different laser source geometries on the thermal history prediction of the thermal model. The present work provides guidelines on appropriate representation of the laser source in the thermal modelling of the SLM process.

  10. A Stable Carbon Nanotube Nanofluid for Latent Heat-Driven Volumetric Absorption Solar Heating Applications

    Directory of Open Access Journals (Sweden)

    Nathan Hordy

    2015-01-01

    Full Text Available Recently, direct solar collection through the use of broadly absorbing nanoparticle suspensions (known as nanofluids has been shown as a promising method to improve efficiencies in solar thermal devices. By utilizing a volatile base fluid, this concept could also be applied to the development of a direct absorption heat pipe for an evacuated tube solar collector. However, for this to happen or for any other light-induced vapor production applications, the nanofluid must remain stable over extended periods of time at high temperatures and throughout repetitive evaporation/condensation cycles. In this work, we report for the first time a nanofluid consisting of plasma-functionalized multiwalled carbon nanotubes (MWCNTs suspended in denatured alcohol, which achieves this required stability. In addition, optical characterization of the nanofluid demonstrates that close to 100% of solar irradiation can be absorbed over a relatively small nanofluid thickness.

  11. Magnetic Resonance Imaging Volumetric Analysis of the Putamen in Children with ADHD: Combined Type versus Control

    Science.gov (United States)

    Wellington, Tasha McMahon; Semrud-Clikeman, Margaret; Gregory, Amanda Louise; Murphy, Jennifer Mary; Lancaster, Jack Lynn

    2006-01-01

    Objective: Volumetric differences in the putamen of boys with ADHD combined subtype with psychopathic traits and controls are investigated. Method: The putamen in 24 archival magnetic resonance imaging scans of 12 boys in residential treatment with symptoms of ADHD and psychopathic traits and 12 community control boys are analyzed using Display…

  12. Heat capacities and volumetric changes in the glass transition range: a constitutive approach based on the standard linear solid

    Science.gov (United States)

    Lion, Alexander; Mittermeier, Christoph; Johlitz, Michael

    2017-09-01

    A novel approach to represent the glass transition is proposed. It is based on a physically motivated extension of the linear viscoelastic Poynting-Thomson model. In addition to a temperature-dependent damping element and two linear springs, two thermal strain elements are introduced. In order to take the process dependence of the specific heat into account and to model its characteristic behaviour below and above the glass transition, the Helmholtz free energy contains an additional contribution which depends on the temperature history and on the current temperature. The model describes the process-dependent volumetric and caloric behaviour of glass-forming materials, and defines a functional relationship between pressure, volumetric strain, and temperature. If a model for the isochoric part of the material behaviour is already available, for example a model of finite viscoelasticity, the caloric and volumetric behaviour can be represented with the current approach. The proposed model allows computing the isobaric and isochoric heat capacities in closed form. The difference c_p -c_v is process-dependent and tends towards the classical expression in the glassy and equilibrium ranges. Simulations and theoretical studies demonstrate the physical significance of the model.

  13. Point, surface and volumetric heat sources in the thermal modelling of selective laser melting

    NARCIS (Netherlands)

    Yang, Y.; Ayas, C.; Brabazon, Dermot; Naher, Sumsun; Ul Ahad, Inam

    2017-01-01

    Selective laser melting (SLM) is a powder based additive manufacturing technique suitable for producing high precision metal parts. However, distortions and residual stresses within products arise during SLM because of the high temperature gradients created by the laser heating. Residual stresses

  14. Fully determined scaling laws for volumetrically heated convective systems, a tool for assessing habitability of exoplanets

    Science.gov (United States)

    Vilella, Kenny; Kaminski, Edouard

    2017-05-01

    The long-term habitability of a planet rises from its ability to generate and maintain an atmosphere through partial melting and volcanism. This question has been mainly addressed in the framework of plate tectonics, which may be too specific to apply to the wide range of internal dynamics expected for exoplanets, and even to the thermal evolution of the early Earth. Here we propose a more general theoretical approach of convection to build a regime diagram giving the conditions for partial melting to occur, in planetary bodies, as a function of key parameters that can be estimated for exoplanets, their size and internal heating rate. To that aim, we introduce a refined view of the Thermal Boundary Layer (TBL) in a convective system heated from within, that focuses on the temperature and thickness of the TBL at the top of the hottest temperature profiles, along which partial melting shall first occur. This ;Hottest Thermal Boundary Layer; (HotTBL) is first characterized using fully theoretical scaling laws based on the dynamics of thermal boundary layers. These laws are the first ones proposed in the literature that do not rely on empirical determinations of dimensionless constants and that apply to both low Rayleigh and high Rayleigh convective regimes. We show that the scaling laws can be successfully applied to planetary bodies by comparing their predictions to full numerical simulations of the Moon. We then use the scaling laws to build a regime diagram for exoplanets. Combined with estimates of internal heating in exoplanets, the regime diagram predicts that in the habitable zone partial melting occurs in planets younger than the Earth.

  15. Suction controlled drying and wetting cycle effects on the volumetric behaviour of a lime-treated high plasticity clay

    Directory of Open Access Journals (Sweden)

    Rosone Marco

    2016-01-01

    Full Text Available The paper presents some experimental results collected on samples recovered from an experimental embankment obtained by compacting a lime-treated clay. Samples were collected soon after the in situ compaction and they were cured in controlled environmental conditions for at least 18 months. Mercury intrusion porosimetry tests (MIP were carried out on freeze-dried specimens to characterize the microstructure of the material. In order to assess the durability of the improved material, laboratory tests focused on the effects of cyclic variations of the degree of saturation on the water retention properties and the volumetric behaviour of the stabilized clay. Collected results show that the lime-treated clay undergoes an almost irreversible volumetric behaviour; this irreversible contraction is associated to severe drying processes, while wetting paths do not produce significant volumetric deformations.

  16. Magnetic resonance imaging volumetric findings in children with Asperger syndrome, nonverbal learning disability, or healthy controls.

    Science.gov (United States)

    Semrud-Clikeman, Margaret; Fine, Jodene Goldenring; Bledsoe, Jesse; Zhu, David C

    2013-01-01

    The purpose of the present study was to evaluate selected regions of interest in children and adolescents with nonverbal learning disabilities (NVLD), Asperger syndrome (AS), and age-matched healthy controls using magnetic resonance imaging (MRI). It was hypothesized that children with AS would show larger volumes of the amygdala and hippocampal regions than the other groups. It was also hypothesized that both clinical groups would show differences in the caudate and anterior cingulate cortex (ACC). There were a total of 89 children in the final sample (31 controls, 29 NVLD, 29 AS). Each child completed a MRI scan as well as basic cognitive screening measures. High-resolution T1-weighted MR volumetric images were acquired. The volume of gray matter, white matter, cerebrospinal fluid (CSF), amygdala, hippocampus, and anterior cingulate cortex (ACC) was obtained. The hypothesis that the AS group would show larger hippocampal and amygdala volumes than the other groups was confirmed. For the AS and NVLD groups, the ACC was found to be significantly smaller than that of the control group. These results suggest that the ACC and amygdala/hippocampal regions are deficient in children with AS, likely contributing to difficulty with modulating of emotional reactivity.

  17. Control challenges in domestic heating systems

    DEFF Research Database (Denmark)

    Thybo, Honglian; Larsen, Lars F. S.; Weitzmann, Peter

    2007-01-01

    The objective of this paper is to analyze domestic heating applications and identify unfavorable building constructions and control challenges to be addressed by high performance heating control systems. Heating of domestic houses use a large amount of the total energy consumption in Scandinavia....... Hence the potential of reducing energy consumption by applying high performance control is vast. Indoor climate issues are becoming more in focus, which also leads to a demand for high performance heating systems. The paper presents an analysis of how the building elements of today's domestic houses...... with water based floor heating affect the control challenge. The analysis is documented with simulation results....

  18. Follow-up after gamma knife radiosurgery for vestibular schwannomas: volumetric and axial control rates

    NARCIS (Netherlands)

    Timmer, F.C.A.; Hanssens, P.E.; Haren, A.E. van; Overbeeke, J.J. van; Mulder, J.J.S.; Cremers, C.W.R.J.; Graamans, K.

    2011-01-01

    OBJECTIVES/HYPOTHESIS: A prospective long-term follow-up study was conducted to evaluate the results of gamma knife radiosurgery (GKRS) for vestibular schwannoma (VS) patients. Both axial and volumetric measurements are used to determine tumor size during follow-up. STUDY DESIGN: Individual

  19. Pressure Controlled Heat Pipe for Precise Temperature Control Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research project will develop Pressure Controlled Heat Pipes (PCHPs) for precise temperature control (milli-Kelvin level). Several...

  20. Magnetic Resonance Spectroscopic Imaging and Volumetric Measurements of the Brain in Patients with Postcancer Fatigue: A Randomized Controlled Trial

    Science.gov (United States)

    Prinsen, Hetty; Heerschap, Arend; Bleijenberg, Gijs; Zwarts, Machiel J.; Leer, Jan Willem H.; van Asten, Jack J.; van der Graaf, Marinette; Rijpkema, Mark; van Laarhoven, Hanneke W. M.

    2013-01-01

    Background Postcancer fatigue is a frequently occurring problem, impairing quality of life. Until now, little is known about (neuro) physiological factors determining postcancer fatigue. For non-cancer patients with chronic fatigue syndrome, certain characteristics of brain morphology and metabolism have been identified in previous studies. We investigated whether these volumetric and metabolic traits are a reflection of fatigue in general and thus also of importance for postcancer fatigue. Methods Fatigued patients were randomly assigned to either the intervention condition (cognitive behavior therapy) or the waiting list condition. Twenty-five patients in the intervention condition and fourteen patients in the waiting list condition were assessed twice, at baseline and six months later. Baseline measurements of 20 fatigued patients were compared with 20 matched non-fatigued controls. All participants had completed treatment of a malignant, solid tumor minimal one year earlier. Global brain volumes, subcortical brain volumes, metabolite tissue concentrations, and metabolite ratios were primary outcome measures. Results Volumetric and metabolic parameters were not significantly different between fatigued and non-fatigued patients. Change scores of volumetric and metabolic parameters from baseline to follow-up were not significantly different between patients in the therapy and the waiting list group. Patients in the therapy group reported a significant larger decrease in fatigue scores than patients in the waiting list group. Conclusions No relation was found between postcancer fatigue and the studied volumetric and metabolic markers. This may suggest that, although postcancer fatigue and chronic fatigue syndrome show strong resemblances as a clinical syndrome, the underlying physiology is different. Trial Registration ClinicalTrials.gov NCT01096641 PMID:24040301

  1. Magnetic resonance spectroscopic imaging and volumetric measurements of the brain in patients with postcancer fatigue: a randomized controlled trial.

    Directory of Open Access Journals (Sweden)

    Hetty Prinsen

    Full Text Available BACKGROUND: Postcancer fatigue is a frequently occurring problem, impairing quality of life. Until now, little is known about (neuro physiological factors determining postcancer fatigue. For non-cancer patients with chronic fatigue syndrome, certain characteristics of brain morphology and metabolism have been identified in previous studies. We investigated whether these volumetric and metabolic traits are a reflection of fatigue in general and thus also of importance for postcancer fatigue. METHODS: Fatigued patients were randomly assigned to either the intervention condition (cognitive behavior therapy or the waiting list condition. Twenty-five patients in the intervention condition and fourteen patients in the waiting list condition were assessed twice, at baseline and six months later. Baseline measurements of 20 fatigued patients were compared with 20 matched non-fatigued controls. All participants had completed treatment of a malignant, solid tumor minimal one year earlier. Global brain volumes, subcortical brain volumes, metabolite tissue concentrations, and metabolite ratios were primary outcome measures. RESULTS: Volumetric and metabolic parameters were not significantly different between fatigued and non-fatigued patients. Change scores of volumetric and metabolic parameters from baseline to follow-up were not significantly different between patients in the therapy and the waiting list group. Patients in the therapy group reported a significant larger decrease in fatigue scores than patients in the waiting list group. CONCLUSIONS: No relation was found between postcancer fatigue and the studied volumetric and metabolic markers. This may suggest that, although postcancer fatigue and chronic fatigue syndrome show strong resemblances as a clinical syndrome, the underlying physiology is different. TRIAL REGISTRATION: ClinicalTrials.gov NCT01096641.

  2. Optimal Control of Solar Heating System

    KAUST Repository

    Huang, Bin-Juine

    2017-02-21

    Forced-circulation solar heating system has been widely used in process and domestic heating applications. Additional pumping power is required to circulate the water through the collectors to absorb the solar energy. The present study intends to develop a maximum-power point tracking control (MPPT) to obtain the minimum pumping power consumption at an optimal heat collection. The net heat energy gain Qnet (= Qs − Wp/ηe) was found to be the cost function for MPPT. The step-up-step-down controller was used in the feedback design of MPPT. The field test results show that the pumping power is 89 W at Qs = 13.7 kW and IT = 892 W/m2. A very high electrical COP of the solar heating system (Qs/Wp = 153.8) is obtained.

  3. Space shuttle heat pipe thermal control systems

    Science.gov (United States)

    Alario, J.

    1973-01-01

    Heat pipe (HP) thermal control systems designed for possible space shuttle applications were built and tested under this program. They are: (1) a HP augmented cold rail, (2) a HP/phase change material (PCM) modular heat sink and (3) a HP radiating panel for compartment temperature control. The HP augmented cold rail is similar to a standard two-passage fluid cold rail except that it contains an integral, centrally located HP throughout its length. The central HP core helps to increase the local power density capability by spreading concentrated heat inputs over the entire rail. The HP/PCM modular heat sink system consists of a diode HP connected in series to a standard HP that has a PCM canister attached to its mid-section. It is designed to connect a heat source to a structural heat sink during normal operation, and to automatically decouple from it and sink to the PCM whenever structural temperatures are too high. The HP radiating panel is designed to conductively couple the panel feeder HPs directly to a fluid line that serves as a source of waste heat. It is a simple strap-on type of system that requires no internal or external line modifications to distribute the heat to a large radiating area.

  4. Effect of rhythmic gymnastics on volumetric bone mineral density and bone geometry in premenarcheal female athletes and controls.

    Science.gov (United States)

    Tournis, S; Michopoulou, E; Fatouros, I G; Paspati, I; Michalopoulou, M; Raptou, P; Leontsini, D; Avloniti, A; Krekoukia, M; Zouvelou, V; Galanos, A; Aggelousis, N; Kambas, A; Douroudos, I; Lyritis, G P; Taxildaris, K; Pappaioannou, N

    2010-06-01

    Weight-bearing exercise during growth exerts positive effects on the skeleton. Our objective was to test the hypothesis that long-term elite rhythmic gymnastics exerts positive effects on volumetric bone mineral density and geometry and to determine whether exercise-induced bone adaptation is associated with increased periosteal bone formation or medullary contraction using tibial peripheral quantitative computed tomography and bone turnover markers. We conducted a cross-sectional study at a tertiary center. We studied 26 elite premenarcheal female rhythmic gymnasts (RG) and 23 female controls, aged 9-13 yr. We measured bone age, volumetric bone mineral density, bone mineral content (BMC), cortical thickness, cortical and trabecular area, and polar stress strength index (SSIp) by peripheral quantitative computed tomography of the left tibia proximal to the distal metaphysis (trabecular) at 14, 38 (cortical), and 66% (muscle mass) from the distal end and bone turnover markers. The two groups were comparable according to height and chronological and bone age. After weight adjustment, cortical BMC, area, and thickness at 38% were significantly higher in RG (P < 0.005-0.001). Periosteal circumference, SSIp, and muscle area were higher in RG (P < 0.01-0.001). Muscle area was significantly associated with cortical BMC, area, and SSIp, whereas years of training showed positive association with cortical BMC, area, and thickness independent of chronological age. RG in premenarcheal girls may induce positive adaptations on the skeleton, especially in cortical bone. Increased duration of exercise is associated with a positive response of bone geometry.

  5. Enhanced gamma ray sensitivity in bismuth triiodide sensors through volumetric defect control

    Energy Technology Data Exchange (ETDEWEB)

    Johns, Paul M.; Baciak, James E.; Nino, Juan C., E-mail: pauljohns@ufl.edu [Nuclear Engineering Program, Department of Materials Science and Engineering, University of Florida, 100 Rhines Hall, Gainesville, Florida 32611 (United States)

    2016-08-29

    Some of the more attractive semiconducting compounds for ambient temperature radiation detector applications are impacted by low charge collection efficiency due to the presence of point and volumetric defects. This has been particularly true in the case of BiI{sub 3}, which features very attractive properties (density, atomic number, band gap, etc.) to serve as a gamma ray detector, but has yet to demonstrate its full potential. We show that by applying growth techniques tailored to reduce defects, the spectral performance of this promising semiconductor can be realized. Gamma ray spectra from >100 keV source emissions are now obtained from high quality Sb:BiI{sub 3} bulk crystals with limited concentrations of defects (point and extended). The spectra acquired in these high quality crystals feature photopeaks with resolution of 2.2% at 662 keV. Infrared microscopy is used to compare the local microstructure between radiation sensitive and non-responsive crystals. This work demonstrates that BiI{sub 3} can be prepared in melt-grown detector-grade samples with superior quality and can acquire the spectra from a variety of gamma ray sources.

  6. Enhanced gamma ray sensitivity in bismuth triiodide sensors through volumetric defect control

    Science.gov (United States)

    Johns, Paul M.; Baciak, James E.; Nino, Juan C.

    2016-08-01

    Some of the more attractive semiconducting compounds for ambient temperature radiation detector applications are impacted by low charge collection efficiency due to the presence of point and volumetric defects. This has been particularly true in the case of BiI3, which features very attractive properties (density, atomic number, band gap, etc.) to serve as a gamma ray detector, but has yet to demonstrate its full potential. We show that by applying growth techniques tailored to reduce defects, the spectral performance of this promising semiconductor can be realized. Gamma ray spectra from >100 keV source emissions are now obtained from high quality Sb:BiI3 bulk crystals with limited concentrations of defects (point and extended). The spectra acquired in these high quality crystals feature photopeaks with resolution of 2.2% at 662 keV. Infrared microscopy is used to compare the local microstructure between radiation sensitive and non-responsive crystals. This work demonstrates that BiI3 can be prepared in melt-grown detector-grade samples with superior quality and can acquire the spectra from a variety of gamma ray sources.

  7. Aggregated Control of Domestic Heat Pumps

    DEFF Research Database (Denmark)

    Nielsen, Kirsten M.; Andersen, Palle; Pedersen, Tom S.

    2013-01-01

    A challenge in Denmark in the near future is to balance the electrical grid due to a large increase in the renewable energy production mainly from wind turbines. In this work an aggregated control system using heat pumps in single family houses to help balancing the grid is investigated. The cont...

  8. Enhancement of Heat Exchanger Control Using Improved PID Controller

    Directory of Open Access Journals (Sweden)

    Gopalakrishna G.

    2009-08-01

    Full Text Available The Proportional, Integral and Derivative (PID controllers are widely used in industrial applications. Their popularity comes from their robust performance and also from their functional simplicity. Temperature control of double tube heat exchanger system is presented and ant colony algorithm for optimizing PID parameters of temperature controller is presented in this paper on the basis of conventional PID controller. Temperature controller based on ant colony optimization for double tube heat exchanger is designed. Simulation results show that, for the case of heat exchanger system, ACO-PID is good model and generalize well. The closed loop unit step response obtained with the proposed PID compares favorably with the one achieved using a conventional PID controller with dynamic closed-loop simulation. More important, the proposed approach takes a fraction of the time spent by the standard technique, without the need of perturbing the closed-loop system.

  9. Volumetric water control in a large-scale open canal irrigation system with many smallholders: The case of Chancay-Lambayeque in Peru

    NARCIS (Netherlands)

    Vos, J.M.C.; Vincent, L.F.

    2011-01-01

    Volumetric water control (VWC) is widely seen as a means to increase productivity through flexible scheduling and user incentives to apply just enough water. However, the technical and social requirements for VWC are poorly understood. Also, many experts assert that VWC in large-scale open canals

  10. Temperature-dependent dynamic control of the TCA cycle increases volumetric productivity of itaconic acid production by Escherichia coli.

    Science.gov (United States)

    Harder, Björn-Johannes; Bettenbrock, Katja; Klamt, Steffen

    2018-01-01

    Based on the recently constructed Escherichia coli itaconic acid production strain ita23, we aimed to improve the productivity by applying a two-stage process strategy with decoupled production of biomass and itaconic acid. We constructed a strain ita32 (MG1655 ΔaceA Δpta ΔpykF ΔpykA pCadCs), which, in contrast to ita23, has an active tricarboxylic acid (TCA) cycle and a fast growth rate of 0.52 hr-1 at 37°C, thus representing an ideal phenotype for the first stage, the growth phase. Subsequently we implemented a synthetic genetic control allowing the downregulation of the TCA cycle and thus the switch from growth to itaconic acid production in the second stage. The promoter of the isocitrate dehydrogenase was replaced by the Lambda promoter (pR ) and its expression was controlled by the temperature-sensitive repressor CI857 which is active at lower temperatures (30°C). With glucose as substrate, the respective strain ita36A grew with a fast growth rate at 37°C and switched to production of itaconic acid at 28°C. To study the impact of the process strategy on productivity, we performed one-stage and two-stage bioreactor cultivations. The two-stage process enabled fast formation of biomass resulting in improved peak productivity of 0.86 g/L/hr (+48%) and volumetric productivity of 0.39 g/L/hr (+22%) in comparison to the one-stage process. With our dynamic production strain, we also resolved the glutamate auxotrophy of ita23 and increased the itaconic acid titer to 47 g/L. The temperature-dependent activation of gene expression by the Lambda promoters (pR /pL ) has been frequently used to improve protein or, in a few cases, metabolite production in two-stage processes. Here we demonstrate that the system can be as well used in the opposite direction to selectively knock-down an essential gene (icd) in E. coli to design a two-stage process for improved volumetric productivity. The control by temperature avoids expensive inducers and has the potential

  11. Force Field Benchmark of Organic Liquids: Density, Enthalpy of Vaporization, Heat Capacities, Surface Tension, Isothermal Compressibility, Volumetric Expansion Coefficient, and Dielectric Constant

    Science.gov (United States)

    2011-01-01

    The chemical composition of small organic molecules is often very similar to amino acid side chains or the bases in nucleic acids, and hence there is no a priori reason why a molecular mechanics force field could not describe both organic liquids and biomolecules with a single parameter set. Here, we devise a benchmark for force fields in order to test the ability of existing force fields to reproduce some key properties of organic liquids, namely, the density, enthalpy of vaporization, the surface tension, the heat capacity at constant volume and pressure, the isothermal compressibility, the volumetric expansion coefficient, and the static dielectric constant. Well over 1200 experimental measurements were used for comparison to the simulations of 146 organic liquids. Novel polynomial interpolations of the dielectric constant (32 molecules), heat capacity at constant pressure (three molecules), and the isothermal compressibility (53 molecules) as a function of the temperature have been made, based on experimental data, in order to be able to compare simulation results to them. To compute the heat capacities, we applied the two phase thermodynamics method (Lin et al. J. Chem. Phys.2003, 119, 11792), which allows one to compute thermodynamic properties on the basis of the density of states as derived from the velocity autocorrelation function. The method is implemented in a new utility within the GROMACS molecular simulation package, named g_dos, and a detailed exposé of the underlying equations is presented. The purpose of this work is to establish the state of the art of two popular force fields, OPLS/AA (all-atom optimized potential for liquid simulation) and GAFF (generalized Amber force field), to find common bottlenecks, i.e., particularly difficult molecules, and to serve as a reference point for future force field development. To make for a fair playing field, all molecules were evaluated with the same parameter settings, such as thermostats and barostats

  12. Influence of Actively Controlled Heat Release Timing on the Performance and Operational Characteristics of a Rotary Valve, Acoustically Resonant Pulse Combustor

    KAUST Repository

    Lisanti, Joel

    2017-01-05

    The influence of heat release timing on the performance and operational characteristics of a rotary valve, acoustically resonant pulse combustor is investigated both experimentally and numerically. Simulation results are obtained by solving the quasi-1D Navier-Stokes equations with forced volumetric heat addition. Experimental efforts modify heat release timing through modulated fuel injection and modification of the fluid dynamic mixing. Results indicate that the heat release timing has a profound effect on the operation and efficiency of the pulse combustor and that this timing can be difficult to control experimentally.

  13. Heat Control via Torque Control in Friction Stir Welding

    Science.gov (United States)

    Venable, Richard; Colligan, Kevin; Knapp, Alan

    2004-01-01

    In a proposed advance in friction stir welding, the torque exerted on the workpiece by the friction stir pin would be measured and controlled in an effort to measure and control the total heat input to the workpiece. The total heat input to the workpiece is an important parameter of any welding process (fusion or friction stir welding). In fusion welding, measurement and control of heat input is a difficult problem. However, in friction stir welding, the basic principle of operation affords the potential of a straightforward solution: Neglecting thermal losses through the pin and the spindle that supports it, the rate of heat input to the workpiece is the product of the torque and the speed of rotation of the friction stir weld pin and, hence, of the spindle. Therefore, if one acquires and suitably processes data on torque and rotation and controls the torque, the rotation, or both, one should be able to control the heat input into the workpiece. In conventional practice in friction stir welding, one uses feedback control of the spindle motor to maintain a constant speed of rotation. According to the proposal, one would not maintain a constant speed of rotation: Instead, one would use feedback control to maintain a constant torque and would measure the speed of rotation while allowing it to vary. The torque exerted on the workpiece would be estimated as the product of (1) the torque-multiplication ratio of the spindle belt and/or gear drive, (2) the force measured by a load cell mechanically coupled to the spindle motor, and (3) the moment arm of the load cell. Hence, the output of the load cell would be used as a feedback signal for controlling the torque (see figure).

  14. A volumetric meter chip for point-of-care quantitative detection of bovine catalase for food safety control

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Xingye; Hu, Jie; Choi, Jane Ru; Huang, Yalin; Wang, Xuemin [The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi' an Jiaotong University, Xi' an, 710049 (China); Bioinspired Engineering and Biomechanics Center (BEBC), Xi' an Jiaotong University, Xi' an, 710049 (China); Lu, Tian Jian, E-mail: tjlu@mail.xjtu.edu.cn [Bioinspired Engineering and Biomechanics Center (BEBC), Xi' an Jiaotong University, Xi' an, 710049 (China); Xu, Feng, E-mail: fengxu@mail.xjtu.edu.cn [The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi' an Jiaotong University, Xi' an, 710049 (China); Bioinspired Engineering and Biomechanics Center (BEBC), Xi' an Jiaotong University, Xi' an, 710049 (China)

    2016-09-07

    A volumetric meter chip was developed for quantitative point-of-care (POC) analysis of bovine catalase, a bioindicator of bovine mastitis, in milk samples. The meter chip displays multiplexed quantitative results by presenting the distance of ink bar advancement that is detectable by the naked eye. The meter chip comprises a poly(methyl methacrylate) (PMMA) layer, a double-sided adhesive (DSA) layer and a glass slide layer fabricated by the laser-etching method, which is typically simple, rapid (∼3 min per chip), and cost effective (∼$0.2 per chip). Specially designed “U shape” reaction cells are covered by an adhesive tape that serves as an on-off switch, enabling the simple operation of the assay. As a proof of concept, we employed the developed meter chip for the quantification of bovine catalase in raw milk samples to detect catalase concentrations as low as 20 μg/mL. The meter chip has great potential to detect various target analytes for a wide range of POC applications. - Highlights: • The meter chip is a standalone point-of-care diagnostic tool with visible readouts of quantification results. • A fast and low cost fabrication protocol (~3 min and ~$0.2 per chip) of meter chip was proposed. • The chip may hold the potential for rapid scaning of bovine mastitis in cattle farms for food safety control.

  15. Modular control of fusion power heating applications

    Energy Technology Data Exchange (ETDEWEB)

    Demers, D. R.

    2012-08-24

    This work is motivated by the growing demand for auxiliary heating on small and large machines worldwide. Numerous present and planned RF experiments (EBW, Lower Hybrid, ICRF, and ECH) are increasingly complex systems. The operational challenges are indicative of a need for components of real-time control that can be implemented with a moderate amount of effort in a time- and cost-effective fashion. Such a system will improve experimental efficiency, enhance experimental quality, and expedite technological advancements. The modular architecture of this control-suite serves multiple purposes. It facilitates construction on various scales from single to multiple controller systems. It enables expandability of control from basic to complex via the addition of modules with varying functionalities. It simplifies the control implementation process by reducing layers of software and electronic development. While conceived with fusion applications in mind, this suite has the potential to serve a broad range of scientific and industrial applications. During the Phase-I research effort we established the overall feasibility of this modular control-suite concept. We developed the fundamental modules needed to implement open-loop active-control and demonstrated their use on a microwave power deposition experiment.

  16. 3D Volumetric Measurements of GH Secreting Adenomas Correlate with Baseline Pituitary Function, Initial Surgery Success Rate, and Disease Control.

    Science.gov (United States)

    Tirosh, Amit; Papadakis, Georgios Z; Chittiboina, Prashant; Lyssikatos, Charalampos; Belyavskaya, Elena; Keil, Meg; Lodish, Maya B; Stratakis, Constantine A

    2017-06-01

    There is scarce data on the clinical utility of volume measurement for growth hormone (GH)-secreting pituitary adenomas. The current study objective was to assess the association between pituitary adenoma volumes and baseline endocrine evaluation, initial surgical success rate, and disease control among patients with acromegaly. A retrospective cohort study was conducted at a clinical research center including patients with acromegaly due to GH-secreting pituitary adenomas. Baseline hormonal evaluation and adenoma characteristics according to MRI were collected. Volumetric measurements of pituitary adenomas were performed using a semi-automated lesion segmentation and tumor-volume assessment tools. Rates of post-operative medical treatment, radiation therapy, and re-operation were gathered from the patients' medical records. Twenty seven patients (11 females) were included, median age 21.0 years (interquartile range 29 years, range 3-61 years). Patients harboring adenomas with a volume <2 000 mm 3 had higher chance to achieve disease remission [94.1% (n=16) vs. 50.0% (n=4), p<0.05]. Adenoma volumes positively correlated with baseline plasma GH levels before and after oral glucose administration, and with plasma IGF-I and PRL levels. Adenoma volume had negative correlation with morning plasma cortisol levels. Finally, patients harboring larger adenomas required 2nd surgery and/or medical treatment more often compared with subjects with smaller adenomas. Accurate 3D volume measurement of GH-secreting pituitary adenomas may be used for the prediction of initial surgery success and for disease control rates among patients with a GH-secreting pituitary adenomas and performs better than standard size assessments. © Georg Thieme Verlag KG Stuttgart · New York.

  17. Tank waste remediation system heat stress control program report, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Carls, D.R.

    1995-09-28

    Protecting employees from heat stress within tank farms during the summer months is challenging. Work constraints typically experienced in tank farms complicate the measures taken to protect employees from heat stress. TWRS-Industrial Hygiene (IH) has endeavored to control heat stress injuries by anticipating, recognizing, evaluating and controlling the factors which lead or contribute to heat stress in Tank Farms. The TWRS Heat Stress Control Program covers such areas as: employee and PIC training, communication of daily heat stress alerts to tank farm personnel, setting work/rest regimens, and the use of engineering and personal protective controls when applicable. The program has increased worker awareness of heat stress and prevention, established provisions for worker rest periods, increased drinking water availability to help ensure worker hydration, and allowed for the increased use of other protective controls to combat heat stress. The TWRS Heat Stress Control Program is the cornerstone for controlling heat stress among tank farm employees. The program has made great strides since it`s inception during the summer of 1994. Some improvements can still be made to enhance the program for the summer of 1996, such as: (1) procurement and use of personal heat stress monitoring equipment to ensure appropriate application of administrative controls, (2) decrease the need for use of containment tents and anti-contamination clothing, and (3) providing a wider variety of engineering and personal protective controls for heat stress prevention

  18. PREDICTIVE CONTROL SYSTEM SYNTHESIS OF DISTRICT HEATING SYSTEM

    Directory of Open Access Journals (Sweden)

    Dobrotin S.A.

    2011-08-01

    Full Text Available A combined system of building heating predictive control has been synthesized in the research. Following algorithms are described: adaptive algorithm of very short-term temperature forecast and algorithm of anticipatory control of heat supply to building heating taking into account different outside climate influence on elevations of a building.

  19. Application of Predictive Control in District Heating Systems

    DEFF Research Database (Denmark)

    Palsson, Olafur Petur; Madsen, Henrik; Søgaard, Henning Tangen

    1993-01-01

    . A district heating system is an example of a non-stationary system, and the model parameters have to be time varying. Hence, the classical predictive control theory has to be modified. Simulation experiments are performed in order to study the performance of modified predictive controllers. The systems ape......In district heating systems, and in particular if the heat production cakes place at a combined heat and power (CHP) plant, a reasonable control strategy is to keep the supply temperature from the district heating plant as low as possible. However, the control is subject to some restrictions...

  20. Fusible heat sink for EVA thermal control

    Science.gov (United States)

    Roebelen, G. J., Jr.

    1975-01-01

    The preliminary design and analysis of a heat sink system utilizing a phase change slurry material to be used eventually for astronaut cooling during manned space missions is described. During normal use, excess heat in the liquid cooling garment coolant is transferred to a reusable/regenerable fusible heat sink. Recharge is accomplished by disconnecting the heat sink from the liquid cooling garment and placing it in an on board freezer for simultaneous slurry refreeze and power supply electrical rechange.

  1. AUTOMATIC CONTROL SYSTEM OF HEAT PUMP STATION GAS COOLER AT THE WIDE RANGE OF HEAT LOAD

    Directory of Open Access Journals (Sweden)

    Juravleov A.A.

    2008-08-01

    Full Text Available There is examined the structure the of control system of gas cooler of heat pump station, which uses the carbon dioxide as the working fluid in the transctitical thermodynamical cycle. It is analiyed the structure of the complex: heat pump station – district heating system.

  2. COMPARATIVEANALYSIS OF ADVANCED CONTROLLERS IN A HEAT EXCHANGER

    OpenAIRE

    P. Sivakumar

    2013-01-01

    Temperature control of the shell and tube heat exchanger is characteristics of nonlinear, time varying and time lag. Since the temperature control with conventional PID controller cannot meet a wide range of precision temperature control requirement, we design temperature control system of the shell and tube heat exchanger by combining fuzzy and PID control methods in this paper. The simulation and experiments are carried out; making a comparison with conventional PID control showing that fuz...

  3. CT-based evaluation of volumetric bone density in fragility fractures of the pelvis-a matched case-control analysis.

    Science.gov (United States)

    Schönenberg, D; Guggenberger, R; Frey, D; Pape, H-C; Simmen, H-P; Osterhoff, G

    2017-11-13

    This matched case-control study compared the computed tomography (CT)-based regional bone density of patients with fragility fractures of the sacrum to a control without fracture. Patients with a sacral fracture demonstrated a significantly lower regional bone density of the sacrum, the sacral bone density not being correlated with the BMD by DXA of the spine. The aim of this study is to compare the computed tomography-based regional bone density measured by Hounsfield units (HUs) in patients with and without fragility fractures of the sacrum. Patients aged ≥ 50 years with a fragility fracture of the sacrum were compared to patients of similar age and gender who had a fall from standing height without fracture (n = 46). A matched case-control analysis was conducted by retrospective chart review and assessment of areal bone mineral density by lumbar DXA and by volumetric regional HU measurements in uncalibrated CT scans of the sacrum. Patients with a sacral fracture (age 74 ± 11 years) showed a lower bone density in the body of S1 (HU 85 ± 22) when compared to the matched control group without fracture (age 73 ± 10 years, HU 125 ± 37, p fractures of the sacrum demonstrated a lower regional volumetric bone density of the sacrum when compared to a cohort without a fracture. Local sacral volumetric bone density as measured by CT seems to be independent from the areal BMD as measured by DXA of the lumbar spine. level III.

  4. An Integrated Control System for Heating and Indoor Climate Applications

    DEFF Research Database (Denmark)

    Tahersima, Fatemeh

    2012-01-01

    Low temperature hydronic heating and cooling systems connected to renewable energy sources have gained more attention in the recent decades. This is due to the growing public awareness of the adverse environmental impacts of energy generation using fossil fuel. Radiant hydronic sub-floor heating...... in terms of energy efficiency, associated energy cost and occupants’ thermal comfort is the main objective to be fulfilled via design of an integrated controller. We also proposed control strategies to manage energy consumption of the building to turn domestic heat demands into a flexible load in the smart...... which geothermal heat pump, solar driven heat pumps and the other types are categorized as renewable or renewable energy sources. In the present study, we investigated modeling and control of hydronic heat emitters integrated with a ground-source heat pump. Optimization of the system performance...

  5. Improved district heating substation efficiency with a new control strategy

    Energy Technology Data Exchange (ETDEWEB)

    Gustafsson, Jonas; Delsing, Jerker; van Deventer, Jan [Div. of EISLAB, Dept. of Computer Science and Electrical Engineering, Luleaa University of Technology, 97187 Luleaa (Sweden)

    2010-06-15

    In this paper, we describe a new alternative control approach for indirectly connected district heating substations. Simulations results showed that the new approach results in an increased {delta} T across the substation. Results were obtained for both ideal and non-ideal operation of the system, meaning that less water must be pumped through the district heating network, and a higher overall fuel efficiency can be obtained in the district heating power plants. When a higher fuel efficiency is achieved, the usage of primary fuel sources can be reduced. Improved efficiency also increases the effective heat transfer capacity of a district heating network, allowing more customers to be connected to an existing network without increasing the heating plant or network capacity. Also, if combined heat and power plants are used to produce the heat, the increased {delta} T will result in a further improved overall fuel efficiency, as more electricity can be produced with colder cooling water. The idea behind the new control method is to consider the temperature of the water supplying the district heating substation with heat, often referred to as the primary supply temperature. This represents a logical next step, as currently, the only parameter generally taken into account or measured when controlling the temperature level of the radiator circuit is the local outdoor temperature. In this paper we show how the primary supply temperature together with thermodynamic knowledge of the building can be used to maximize the {delta} T across the district heating substation. (author)

  6. Dynamics Analysis of Frequency-Controlled Volumetric Hydraulic Drive with Power Supplied from the Built-in Pneumatic-Hydraulic Accumulator

    Directory of Open Access Journals (Sweden)

    Yu. Yu. Zuev

    2015-01-01

    Full Text Available The paper offers a volumetric hydraulic drive structure consisting of an unregulated pump, hydraulic motor, and energy accumulation block with pneumatic-hydraulic accumulator (PHA. Drive control is provided through frequency modification of current arriving at the asynchronous electric drive (AED from the frequency changer.The paper describes drive advantages when the energy accumulation block is set to allow power accumulation both from the AED and in recuperation regimes with moving outlet drive link with assisting loads. It offers simulation models and computer programmes to analyze a non-stationary movement of the outlet link of volumetric hydraulic drive with frequency control (VHD-FC with hydraulic motor power supplied from the PHA. The paper examines acceleration regimes of motor axis under different loads and presents PHA energy characteristics and algorithms to find desirable operational non-displaced and constructional accumulator capacities that provide motor outlet link acceleration up to the necessary speed. It presents graphs to show changing motor axis angle speed and PHA-displaced fluid volume as well as energy and PHA power during its discharge versus acceleration time of the motor axis. These dependences are obtained through varying different parameters of the system, namely: inertia, viscous friction, constant load moment, and volumetric displacement.The paper shows that decrease of inertia load and use of hydraulic motor with high volume constants result in the most essentially reduced acceleration time. Setting the PHA allows more than 2.5 times decreasing acceleration time of the motor axis. At the same time, because of the evidently complicated VHD-FC, taking decision on the sound PHA design and parameters must be based on the integration analysis of requirements. These requirements concern the VHD-FC reliability and performance in standard and failure modes as well as the technical-and-economic indexes and operation

  7. TEMPERATURE DISTRIBUTION MONITORING AND ANALYSES AT DIFFERENT HEATING CONTROL PRINCIPLES

    DEFF Research Database (Denmark)

    Simone, Angela; Rode, Carsten; Olesen, Bjarne W.

    2010-01-01

    control sensor which was already installed. The room was heated by means of electrical radiators, which should be able to control the indoor environment to guarantee the desired thermal conditions for the occupants and to supply heat according to desired load patterns. Five series of experiments were done...

  8. Toolchain for User-Centered Intelligent Floor Heating Control

    DEFF Research Database (Denmark)

    Agesen, Mads Kronborg; Larsen, Kim Guldstrand; Mikučionis, Marius

    2016-01-01

    Floor heating systems are important components of nowadays home-automation setups. The control of a floor heating system is a nontrivial task and the present solutions essentially implement variants of a simple bang-bang controller that opens for a hot water circulation in a room if its current...... floor heating control based on a chain of tools that allow us to gather the sensor readings from the actual hardware and use the state-of-the-art controller synthesis tool UPPAAL Stratego in order to synthesise abstract control strategies that are then executed on the real hardware platform provided...

  9. Heat exchanger modeling and identification for control of waste heat recovery systems in diesel engines

    NARCIS (Netherlands)

    Feru, E.; Willems, F.P.T.; Rojer, C.; Jager, B. de; Steinbuch, M.

    2013-01-01

    To meet future CO2 emission targets, Waste Heat Recovery systems have recently attracted much attention for automotive applications, especially for long haul trucks. This paper focuses on the development of a dynamic counter-flow heat exchanger model for control purposes. The model captures the

  10. Absorption Cycle Heat Pump Model for Control Design

    DEFF Research Database (Denmark)

    Vinther, Kasper; Just Nielsen, Rene; Nielsen, Kirsten Mølgaard

    2015-01-01

    Heat pumps have recently received increasing interest due to green energy initiatives and increasing energy prices. In this paper, a nonlinear dynamic model of a single-effect LiBr-water absorption cycle heat pump is derived for simulation and control design purposes. The model is based...... on an actual heat pump located at a larger district heating plant. The model is implemented in Modelica and is based on energy and mass balances, together with thermodynamic property functions for LiBr and water and staggered grid representations for heat exchangers. Model parameters have been fitted...... to operational data and different scenarios are simulated to investigate the operational stability of the heat pump. Finally, this paper provides suggestions and examples of derivation of lower order linear models for control design. © Copyright IEEE - All rights reserved....

  11. Model-based control of district heating supply temperature

    Energy Technology Data Exchange (ETDEWEB)

    Saarinen, Linn

    2010-11-15

    A model-based control strategy for the supply temperature to a district heating network was tested during three weeks at Idbaecken's CHP plant. The aim was to increase the electricity efficiency by a lower supply temperature, without risking the delivery reliability of heat to the district heating customers. Simulations and tests showed that at high loads, the mean supply temperature could be reduced by 4 deg C and the electricity production could be increased by 2.5%

  12. Genetic and epigenetic control of plant heat responses

    Directory of Open Access Journals (Sweden)

    Junzhong eLiu

    2015-04-01

    Full Text Available Plants have evolved sophisticated genetic and epigenetic regulatory systems to respond quickly to unfavorable environmental conditions such as heat, cold, drought, and pathogen infections. In particular, heat greatly affects plant growth and development, immunity and circadian rhythm, and poses a serious threat to the global food supply. According to temperatures exposing, heat can be usually classified as warm ambient temperature (about 22-27℃, high temperature (27-30℃ and extremely high temperature (37-42℃, also known as heat stress for the model plant Arabidopsis thaliana. The genetic mechanisms of plant responses to heat have been well studied, mainly focusing on elevated ambient temperature-mediated morphological acclimation and acceleration of flowering, modulation of plant immunity and circadian clock by high temperatures, and thermotolerance to heat stress. Recently, great progress has been achieved on epigenetic regulation of heat responses, including DNA methylation, histone modifications, histone variants, ATP-dependent chromatin remodeling, histone chaperones, small RNAs, long non-coding RNAs and other undefined epigenetic mechanisms. These epigenetic modifications regulate the expression of heat-responsive genes and function to prevent heat-related damage. This review focuses on recent progresses regarding the genetic and epigenetic control of heat responses in plants, and pays more attention to the role of the major epigenetic mechanisms in plant heat responses. Further research perspectives are also discussed.

  13. Hybrid Heat Pipes for High Heat Flux Spacecraft Thermal Control Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Grooved aluminum/ammonia Constant Conductance Heat Pipes (CCHPs) are the standard for thermal control in zero-gravity. Unfortunately, they are limited in terms of...

  14. Supervisory Model Predictive Control of the Heat Integrated Distillation Column

    DEFF Research Database (Denmark)

    Meyer, Kristian; Bisgaard, Thomas; Huusom, Jakob Kjøbsted

    2017-01-01

    This paper benchmarks a centralized control system based on model predictive control for the operation of the heat integrated distillation column (HIDiC) against a fully decentralized control system using the most complete column model currently available in the literature. The centralized control...

  15. Plug and Play Process Control of a District Heating System

    DEFF Research Database (Denmark)

    Trangbaek, Klaus; Knudsen, Torben; Skovmose Kallesøe, Carsten

    2009-01-01

    The main idea of plug and play process control is to initialise and reconfigure control systems automatically. In this paper these ideas are applied to a scaled laboratory model of a district heating pressure control system.  First of all this serves as a concrete example of plug and play control...

  16. The predictive protective control of the heat exchanger

    Science.gov (United States)

    Nevriva, Pavel; Filipova, Blanka; Vilimec, Ladislav

    2016-06-01

    The paper deals with the predictive control applied to flexible cogeneration energy system FES. FES was designed and developed by the VITKOVICE POWER ENGINEERING joint-stock company and represents a new solution of decentralized cogeneration energy sources. In FES, the heating medium is flue gas generated by combustion of a solid fuel. The heated medium is power gas, which is a gas mixture of air and water steam. Power gas is superheated in the main heat exchanger and led to gas turbines. To protect the main heat exchanger against damage by overheating, the novel predictive protective control based on the mathematical model of exchanger was developed. The paper describes the principle, the design and the simulation of the predictive protective method applied to main heat exchanger of FES.

  17. Heating tar sands formations while controlling pressure

    Science.gov (United States)

    Stegemeier, George Leo [Houston, TX; Beer, Gary Lee [Houston, TX; Zhang, Etuan [Houston, TX

    2010-01-12

    Methods for treating a tar sands formation are described herein. Methods may include heating at least a section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. A pressure in the majority of the section may be maintained below a fracture pressure of the formation. The pressure in the majority of the section may be reduced to a selected pressure after the average temperature reaches a temperature that is above 240.degree. C. and is at or below pyrolysis temperatures of hydrocarbons in the section. At least some hydrocarbon fluids may be produced from the formation.

  18. Areal and volumetric bone mineral density and geometry at two levels of protein intake during caloric restriction: a randomized, controlled trial.

    Science.gov (United States)

    Sukumar, Deeptha; Ambia-Sobhan, Hasina; Zurfluh, Robert; Schlussel, Yvette; Stahl, Theodore J; Gordon, Chris L; Shapses, Sue A

    2011-06-01

    Weight reduction induces bone loss by several factors, and the effect of higher protein (HP) intake during caloric restriction on bone mineral density (BMD) is not known. Previous study designs examining the longer-term effects of HP diets have not controlled for total calcium intake between groups and have not examined the relationship between bone and endocrine changes. In this randomized, controlled study, we examined how BMD (areal and volumetric), turnover markers, and hormones [insulin-like growth factor 1 (IGF-1), IGF-binding protein 3 (IGFBP-3), 25-hydroxyvitamin D, parathyroid hormone (PTH), and estradiol] respond to caloric restriction during a 1-year trial using two levels of protein intake. Forty-seven postmenopausal women (58.0 ± 4.4 years; body mass index of 32.1 ± 4.6 kg/m(2) ) completed the 1-year weight-loss trial and were on a higher (HP, 24%, n = 26) or normal protein (NP, 18%, n = 21) and fat intake (28%) with controlled calcium intake of 1.2 g/d. After 1 year, subjects lost 7.0% ± 4.5% of body weight, and protein intake was 86 and 60 g/d in the HP and NP groups, respectively. HP compared with NP diet attenuated loss of BMD at the ultradistal radius, lumbar spine, and total hip and trabecular volumetric BMD and bone mineral content of the tibia. This is consistent with the higher final values of IGF-1 and IGFBP-3 and lower bone-resorption marker (deoxypyridinoline) in the HP group than in the NP group (p bone loss at certain sites in postmenopausal women. Copyright © 2011 American Society for Bone and Mineral Research.

  19. Volumetric Heat Generation and Consequence Raise in Temperature Due to Absorption of Neutrons from Thermal up to 14.9 MeV Energies

    CERN Document Server

    Massoud, E

    2003-01-01

    In this work, the heat generation rate and the consequence rise in temperature due to absorption of all neutrons from thermal energies (E<0.025) up to 14.9 MeV in water, paraffin wax, ordinary concrete and heavy concrete and heavy concrete as some selected hydrogenous materials are investigated. The neutron flux distributions are calculated by both ANISN-code and three group method in which the fast neutrons are expressed by the removal cross section concept while the other two groups (epithermal and thermal) are treated by the diffusion equation. The heat generation can be calculated from the neutron macroscopic absorption of each material or mixture multiplied by the corresponding neutron fluxes. The rise in temperature is then calculated by using both of the heat generation and the thermal conductivity of the selected materials. Some results are compared with the available experimental and theoretical data and a good agreement is achieved.

  20. Maximum-power-point tracking control of solar heating system

    KAUST Repository

    Huang, Bin-Juine

    2012-11-01

    The present study developed a maximum-power point tracking control (MPPT) technology for solar heating system to minimize the pumping power consumption at an optimal heat collection. The net solar energy gain Q net (=Q s-W p/η e) was experimentally found to be the cost function for MPPT with maximum point. The feedback tracking control system was developed to track the optimal Q net (denoted Q max). A tracking filter which was derived from the thermal analytical model of the solar heating system was used to determine the instantaneous tracking target Q max(t). The system transfer-function model of solar heating system was also derived experimentally using a step response test and used in the design of tracking feedback control system. The PI controller was designed for a tracking target Q max(t) with a quadratic time function. The MPPT control system was implemented using a microprocessor-based controller and the test results show good tracking performance with small tracking errors. It is seen that the average mass flow rate for the specific test periods in five different days is between 18.1 and 22.9kg/min with average pumping power between 77 and 140W, which is greatly reduced as compared to the standard flow rate at 31kg/min and pumping power 450W which is based on the flow rate 0.02kg/sm 2 defined in the ANSI/ASHRAE 93-1986 Standard and the total collector area 25.9m 2. The average net solar heat collected Q net is between 8.62 and 14.1kW depending on weather condition. The MPPT control of solar heating system has been verified to be able to minimize the pumping energy consumption with optimal solar heat collection. © 2012 Elsevier Ltd.

  1. Graphitization of oil palm trunk chip with controlled heating condition

    Science.gov (United States)

    Karim, N. A.; Ghazali, C. M. R.; Ramli, M. M.; Halin, D. S. C.; Nainggolan, I.

    2017-09-01

    The purpose of this study is to synthesize the synthetic graphite from oil palm trunk at lower temperature (various heating temperatures, 500 °C, 800 °C and 1,000 °C) with controlled condition and study the physical properties and characterization of the graphite obtained. After heat treatment process, the samples were characterized by X-Ray Diffraction (XRD) and analyzed using X'Pert Highscore Plus software. The morphological study was carried out by using Field Emission Electro Scanning Microscope (FESEM). Based on the analysis, by heating of the sample at 800 °C, the amorphous carbon and nanocrystalline graphite were observed.

  2. Finite approximate controllability for semilinear heat equations in noncylindrical domains

    Directory of Open Access Journals (Sweden)

    Menezes Silvano B. de

    2004-01-01

    Full Text Available We investigate finite approximate controllability for semilinear heat equation in noncylindrical domains. First we study the linearized problem and then by an application of the fixed point result of Leray-Schauder we obtain the finite approximate controllability for the semilinear state equation.

  3. Analysis of Decentralized Control for Absorption Cycle Heat Pumps

    DEFF Research Database (Denmark)

    Vinther, Kasper; Just Nielsen, Rene; Nielsen, Kirsten Mølgaard

    2015-01-01

    Email Print Request Permissions This paper investigates decentralized control structures for absorption cycle heat pumps and a dynamic nonlinear model of a single-effect LiBr-water absorption system is used as case study. The model has four controllable inputs, which can be used to stabilize...

  4. A control model for district heating networks with storage

    NARCIS (Netherlands)

    Scholten, Tjeert; De Persis, Claudio; Tesi, Pietro

    2014-01-01

    In [1] pressure control of hydraulic networks is investigated. We extend this work to district heating systems with storage capabilities and derive a model taking the topology of the network into account. The goal for the derived model is that it should allow for control of the storage level and

  5. Volumetric composition of nanocomposites

    DEFF Research Database (Denmark)

    Madsen, Bo; Lilholt, Hans; Mannila, Juha

    2015-01-01

    Detailed characterisation of the properties of composite materials with nanoscale fibres is central for the further progress in optimization of their manufacturing and properties. In the present study, a methodology for the determination and analysis of the volumetric composition of nanocomposites...... significant figures. The plotting of the measured nanocomposite density as a function of the nanofibre weight content is shown to be a first good approach of assessing the porosity content of the materials. The known gravimetric composition of the nanocomposites is converted into a volumetric composition....... An analytical model, previously established for conventional fibre composites, is used for the analysis of the volumetric composition. For the aluminosilicate/polylactate nanocomposites, based on the established linear relationship between the porosity content and the fibre volume content, the fibre correlated...

  6. Nanomodified heat-accumulating materials controlled by a magnetic field

    Science.gov (United States)

    Shchegolkov, Alexander; Shchegolkov, Alexey; Dyachkova, Tatyana; Bodin, Nikolay; Semenov, Alexander

    2017-11-01

    The paper presents studies of nanomodified heat-accumulating materials controlled by a magnetic field. In order to obtain controlled heat-accumulating materials, synthetic motor oil CASTROL 0W30, ferromagnetic particles, CNTs and paraffin were used. Mechanically activated carbon nanotubes with ferromagnetic particles were used for the nanomodification of paraffin. Mechanoactivation ensured the production of ferromagnetic particles with an average particle size of 5 µm. Using an extrusion plant, a mixture of CNTs and ferromagnetic particles was introduced into the paraffin. Further, the nanomodified paraffin in a granular form was introduced into synthetic oil. To conduct experimental studies, a contactless method for measuring temperature was used. The thermal contact control with the help of the obtained nanomodified material is possible with a magnetic induction of 1250 mT, and a heat flux of about 74 kW/m2 is provided at the same time.

  7. 1-D diffusion based solidification model with volumetric expansion and shrinkage effect: A semi-analytical approach

    Science.gov (United States)

    Monde, Aniket D.; Chakraborty, Prodyut R.

    2017-10-01

    Volumetric expansion and shrinkage due to different densities of solid and liquid phases are common phenomena during solidification process. Simple analytical models addressing effect of volumetric expansion/shrinkage during solidification are rarely found. The few existing 1-D solidification models are valid only for semi-infinite domain with limitations of their application for finite domain size. The focus of the present work is to develop a 1-D semi-analytical solidification model addressing effects of volumetric expansion/shrinkage in a finite domain. The proposed semi-analytical scheme involves finding simultaneous solution of transient 1-D heat diffusion equations at solid and liquid domain coupled at the interface by Stefan condition. The change of the total domain length during solidification due to volumetric expansion/shrinkage is addressed by using mass conservation. For validation of the proposed model, solidification of water in a finite domain is studied without considering volumetric expansion/shrinkage effect and results are compared with those obtained from existing enthalpy updating based numerical model. After validation, case studies pertaining to volumetric expansion and shrinkage are performed considering solidification of water and paraffin respectively and physically consistent results are obtained. The study is relevant for understanding unidirectional crystal growth under the effect of controlled boundary condition.

  8. Exhaust bypass flow control for exhaust heat recovery

    Science.gov (United States)

    Reynolds, Michael G.

    2015-09-22

    An exhaust system for an engine comprises an exhaust heat recovery apparatus configured to receive exhaust gas from the engine and comprises a first flow passage in fluid communication with the exhaust gas and a second flow passage in fluid communication with the exhaust gas. A heat exchanger/energy recovery unit is disposed in the second flow passage and has a working fluid circulating therethrough for exchange of heat from the exhaust gas to the working fluid. A control valve is disposed downstream of the first and the second flow passages in a low temperature region of the exhaust heat recovery apparatus to direct exhaust gas through the first flow passage or the second flow passage.

  9. Thermoelectric Exhaust Heat Recovery with Heat Pipe-Based Thermal Control

    Science.gov (United States)

    Brito, F. P.; Martins, Jorge; Hançer, Esra; Antunes, Nuno; Gonçalves, L. M.

    2015-06-01

    Heat pipe (HP)-based heat exchangers can be used for very low resistance heat transfer between a hot and a cold source. Their operating temperature depends solely on the boiling point of their working fluid, so it is possible to control the heat transfer temperature if the pressure of the HP can be adjusted. This is the case of the variable conductance HPs (VCHP). This solution makes VCHPs ideal for the passive control of thermoelectric generator (TEG) temperature levels. The present work assesses, both theoretically and experimentally, the merit of the aforementioned approach. A thermal and electrical model of a TEG with VCHP assist is proposed. Experimental results obtained with a proof of concept prototype attached to a small single-cylinder engine are presented and used to validate the model. It was found that the HP heat exchanger indeed enables the TEG to operate at a constant, optimal temperature in a passive and safe way, and with a minimal overall thermal resistance, under part load, it effectively reduces the active module area without deprecating the temperature level of the active modules.

  10. Thermal control of electronic equipment by heat pipes; Controle thermique de composants electroniques par caloducs

    Energy Technology Data Exchange (ETDEWEB)

    Groll, M.; Schneider, M. [Stuttgart Univ. (Germany). Inst. fuer Kernenergetik und Energiesysteme; Sartre, V.; Chaker Zaghdoudi, M.; Lallemand, M. [Institut National des Sciences Appliquees (INSA), 69 - Villeurbanne (France). Centre de Thermique de Lyon, Upresa CNRS

    1998-05-01

    In the frame of the BRITE-EURAM european programme (KHIEPCOOL project), a literature survey on the main beat pipe and micro heat pipe technologies developed for thermal control of electronic equipment has been carried out. The conventional heat pipes are cylindrical, flat or bellow tubes, using wicks or axial grooves as capillary structures. In the field of micro heat pipes, the component interconnection substrate. The best performances were achieved with Plesch`s axially grooved flat miniature heat pipe, which is able to transfer a heat flux of about 60 W.cm{sup -2}. Theoretical models have shown that the performance of micro heat pipe arrays increase with increasing tube diameter, decreasing tube length and increasing heat pipe density. The heat pipe technologies are classified and compared according to their geometry and location in the system. A list of about 150 references, classified according to their subjects, is presented. (authors) 160 refs.

  11. Mold Heating and Cooling Pump Package Operator Interface Controls Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Josh A. Salmond

    2009-08-07

    The modernization of the Mold Heating and Cooling Pump Package Operator Interface (MHC PP OI) consisted of upgrading the antiquated single board computer with a proprietary operating system to off-the-shelf hardware and off-the-shelf software with customizable software options. The pump package is the machine interface between a central heating and cooling system that pumps heat transfer fluid through an injection or compression mold base on a local plastic molding machine. The operator interface provides the intelligent means of controlling this pumping process. Strict temperature control of a mold allows the production of high quality parts with tight tolerances and low residual stresses. The products fabricated are used on multiple programs.

  12. Optimal Control of Diesel Engines with Waste Heat Recovery System

    NARCIS (Netherlands)

    Willems, F.P.T.; Donkers, M.C.F.; Kupper, F.

    2014-01-01

    This study presents an integrated energy and emission management strategy for a Euro-VI diesel engine with Waste Heat Recovery (WHR) system. This Integrated Powertrain Control (IPC) strategy optimizes the CO2-NOx trade-off by minimizing the operational costs associated with fuel and AdBlue

  13. The heat treatment of steel. A mathematical control problem

    Energy Technology Data Exchange (ETDEWEB)

    Hoemberg, Dietmar; Kern, Daniela

    2009-07-21

    The goal of this paper is to show how the heat treatment of steel can be modelled in terms of a mathematical optimal control problem. The approach is applied to laser surface hardening and the cooling of a steel slab including mechanical effects. Finally, it is shown how the results can be utilized in industrial practice by a coupling with machine-based control. (orig.)

  14. Modeling and Experimental Validation of a Volumetric Expander Suitable for Waste Heat Recovery from an Automotive Internal Combustion Engine Using an Organic Rankine Cycle with Ethanol

    Directory of Open Access Journals (Sweden)

    José Galindo

    2016-04-01

    Full Text Available Waste heat recovery (WHR in exhaust gas flow of automotive engines has proved to be a useful path to increase the overall efficiency of internal combustion engines (ICE. Recovery potentials of up to 7% are shown in several works in the literature. However, most of them are theoretical estimations. Some present results from prototypes fed by steady flows generated in an auxiliary gas tank and not with actual engine exhaust gases. This paper deals with the modeling and experimental validation of an organic Rankine cycle (ORC with a swash-plate expander integrated in a 2 L turbocharged petrol engine using ethanol as working fluid. A global simulation model of the ORC was developed with a maximum difference of 5%, validated with experimental results. Considering the swash-plate as the main limiting factor, an additional specific submodel was implemented to model the physical phenomena in this element. This model allows simulating the fluid dynamic behavior of the swash-plate expander using a 0D model (Amesim. Differences up to 10.5% between tests and model results were found.

  15. Clinical application of controlled aliasing in parallel imaging results in a higher acceleration (CAIPIRINHA)-volumetric interpolated breathhold (VIBE) sequence for gadoxetic acid-enhanced liver MR imaging.

    Science.gov (United States)

    Yu, Mi Hye; Lee, Jeong Min; Yoon, Jeong-Hee; Kiefer, Berthold; Han, Joon Koo; Choi, Byung-Ihn

    2013-11-01

    To determine whether a controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) technique can improve the image quality of three-dimensional (3D), T1-weighted gradient echo (T1w-GRE) imaging compared with the use of a standard, parallel acquisition technique (PAT). Sixty-four patients who underwent liver MR on a 3 Tesla (T) scanner, were included in this study. Twenty minutes after the injection of 0.025 mmole/kg of gadoxetic acid, 3D T1w-GRE imaging (volumetric interpolated breathhold examination [VIBE]) was acquired twice using a generalized autocalibrating partially parallel acquisition (384 × 250 matrix, acceleration factor [AF] of 2) and a CAIPIRINHA (384 × 380 matrix, AF of 4), respectively. Qualitative image analysis was performed for two image sets. CAIPIRINHA-VIBE showed better hepatic vessel clarity and lesion conspicuity than standard VIBE (P spatial resolution, T1-weighted imaging with better image quality compared with a standard VIBE. Copyright © 2013 Wiley Periodicals, Inc.

  16. The Use Of Multifrequency Induction Heating For Temperature Distribution Control

    Directory of Open Access Journals (Sweden)

    Smalcerz A.

    2015-06-01

    Full Text Available The paper presents possibilities of controlling temperature field distribution in inductively heated charge. The change of its distribution was obtained using the sequential one-, two-, and three-frequency heating. The study was conducted as a multi-variant computer simulation of hard coupled electromagnetic and temperature fields. For the analysis, a professional calculation software package utilizing the finite element method, Flux 3D, was used. The problem of obtaining an appropriate temperature distribution in the heated charge of a complex shape is very important in many practical applications. A typical example is hardening of gear wheels. For such an application, it is necessary to obtain (on the surface and at a desired depth an uniform temperature distribution on the tooth face, top land and bottom land of the gear. The obtained temperature should have proper distribution and value. Such a distribution is very difficult to achieve.

  17. Control of microwave heating of peritoneal dialysis solutions.

    Science.gov (United States)

    Deutschendorf, A F; Wenk, R E; Lustgarten, J; Mason, P

    1994-01-01

    To determine if microwave heating of dialysis solutions to 37 degrees C produced focal overheating (hot spots) and caramelization of dextrose. In vitro determination of conditions for controlling time, temperature, and procedures. Bags had been stored at ambient room temperature. Solution and external bag surface temperature determinations. Dextrose degradation products determined spectrophotometrically. Microscopy for potential caramel precipitates. A microwave oven with no rotation tray produced uneven heating of bags of two commercially available concentrations of dialysis solutions. The greatest hot spots were evident in spike ports. External bag surface temperatures were within 0.20 degrees C of reservoir temperatures. Initial solution temperatures correlated with temperatures of the solutions after microwave heating (r = 0.895). No statistically significant differences were found between dextrose degradation product concentrations of unheated and heated solutions, including hot spots. No precipitates were observed microscopically. Despite the presence of solution hot spots in bag infusion ports, 37 degrees C temperatures were achievable in the bag reservoirs with no evidence of increased glucose degradation. This outcome is assured if the initial temperature and the microwave conditions (procedure, time, mixing of solution) are held constant, and the external bag temperatures are measured after heating.

  18. Analysis and control of nonlinear dynamical behavior with applications to selected interfacial and volumetric materials-related phenomena

    Science.gov (United States)

    Gupta, Arnab

    2000-10-01

    The objective of this study was to apply recently developed concepts in the area of nonlinear dynamics to a spectrum of materials-related problems. New models were developed to describe the Portevin---Le Chatelier (PLC) effect and the growth of thin films by ballistic deposition. In addition, a variety of control strategies were developed, intended to favorably alter the dynamical behavior of nonlinear systems. A generalized mathematical description of the PLC effect was presented in the form of delay differential equations. Existing dislocation evolution equations from literature were modified by including a time-delay effect and shown to reproduce experimentally measured characteristics. A new model, based on evolution of the fraction of mobile dislocations due to pinning and depinning by solute atoms, was developed is. The temperature and strain-rate conditions for the PLC effect were mathematically established based on this model. The existence of critical strains and negative strain-rate sensitivity was also explained. A cellular automata-based simple model was developed separately to study slip behavior during inhomogeneous deformation. The change in reloading time and serration amplitude of stress with applied strain-rate from simulations showed good agreement with experimental results. Existing models of chemisorption, thin film growth, plastic instabilities, and voltage collapse in electrical power systems were studied using established techniques for characterizing nonlinear processes. Simple feedback methods including derivative control were used to stabilize certain instabilities in these model systems. The robustness of the control methods was evaluated. Three new feedback methods for control were developed and successfully applied to stabilize an unstable fixed point in a model for dissociative chemisorption of a diatomic gas. A discrete model was developed to simulate the phenomena of surface growth by ballistic deposition. Three parameters were

  19. The efficacy of radiant heat controls on workers' heat stress around the blast furnace of a steel industry.

    Science.gov (United States)

    Giahi, Omid; Darvishi, Ebrahim; Aliabadi, Mohsen; Khoubi, Jamshid

    2015-01-01

    Workers' exposure to excessive heat in molten industries is mainly due to radiant heat from hot sources. The aim of this study was to evaluate the efficacy of radiant heat controls on workers heat stress around a typical blast furnace. Two main interventions were applied for reducing radiant heat around the blast furnace of a steel industry located in western Iran. These included using a heat absorbing system in the furnace body and installing reflective aluminum barrier in the main workstation. Heat stress indexes were measured before and after each intervention using the digital WBGT-meter. The results showed MRT and WBGT indexes decreased by 20 °C and 3.9 °C, respectively after using heat absorbing system and also decreased by 18.6 °C and 2.5 °C, respectively after installing a reflective barrier. These indexes decrease by 26.5 °C and 5.2 °C, respectively due to the simultaneous application of the two interventions which were statistically significant (p heat control at source can be considered as a first solution for reducing radiant heat of blast furnaces. However, the simultaneous application of interventions could noticeably reduce worker heat stress. The results provide reliable information in order to implement the effective heat controls in typical hot steel industries.

  20. Boundary control of nonlinear coupled heat systems using backstepping

    KAUST Repository

    Bendevis, Paul

    2016-10-20

    A state feedback boundary controller is designed for a 2D coupled PDE system modelling heat transfer in a membrane distillation system for water desalination. Fluid is separated into two compartments with nonlinear coupling at a membrane boundary. The controller sets the temperature on one boundary in order to track a temperature difference across the membrane boundary. The control objective is achieved by an extension of backstepping methods to these coupled equations. Stability of the target system via Lyapunov like methods, and the invertibility of the integral transformation are used to show the stability of the tracking error.

  1. The algorithms for control of heating massive material

    Directory of Open Access Journals (Sweden)

    Karol Kostúr

    2008-03-01

    Full Text Available In numerous technological processes a change on the output follows change on the input pending specific time. This time is called dead time and if this time is too large, it causes problems in the control. This contribution is aimed at analyzing the algorithms of discreet regulation of the systems with dead time. Verified were classical PID regulator and a regulator using Dead Beat method. The control was also tried with Dead interval method. The regulators were tested by simulation and in the electrical laboratory furnace. The task was to control the temperature inside the material heated by furnace power.

  2. Earliest Deadline Control of a Group of Heat Pumps with a Single Energy Source

    NARCIS (Netherlands)

    Fink, J.; van Leeuwen, Richard Pieter

    2016-01-01

    In this paper, we develop and investigate the optimal control of a group of 104 heat pumps and a central Combined Heat and Power unit (CHP). The heat pumps supply space heating and domestic hot water to households. Each house has a buffer for domestic hot water and a floor heating system for space

  3. Pipeline heating method based on optimal control and state estimation

    Energy Technology Data Exchange (ETDEWEB)

    Vianna, F.L.V. [Dept. of Subsea Technology. Petrobras Research and Development Center - CENPES, Rio de Janeiro, RJ (Brazil)], e-mail: fvianna@petrobras.com.br; Orlande, H.R.B. [Dept. of Mechanical Engineering. POLI/COPPE, Federal University of Rio de Janeiro - UFRJ, Rio de Janeiro, RJ (Brazil)], e-mail: helcio@mecanica.ufrj.br; Dulikravich, G.S. [Dept. of Mechanical and Materials Engineering. Florida International University - FIU, Miami, FL (United States)], e-mail: dulikrav@fiu.edu

    2010-07-01

    In production of oil and gas wells in deep waters the flowing of hydrocarbon through pipeline is a challenging problem. This environment presents high hydrostatic pressures and low sea bed temperatures, which can favor the formation of solid deposits that in critical operating conditions, as unplanned shutdown conditions, may result in a pipeline blockage and consequently incur in large financial losses. There are different methods to protect the system, but nowadays thermal insulation and chemical injection are the standard solutions normally used. An alternative method of flow assurance is to heat the pipeline. This concept, which is known as active heating system, aims at heating the produced fluid temperature above a safe reference level in order to avoid the formation of solid deposits. The objective of this paper is to introduce a Bayesian statistical approach for the state estimation problem, in which the state variables are considered as the transient temperatures within a pipeline cross-section, and to use the optimal control theory as a design tool for a typical heating system during a simulated shutdown condition. An application example is presented to illustrate how Bayesian filters can be used to reconstruct the temperature field from temperature measurements supposedly available on the external surface of the pipeline. The temperatures predicted with the Bayesian filter are then utilized in a control approach for a heating system used to maintain the temperature within the pipeline above the critical temperature of formation of solid deposits. The physical problem consists of a pipeline cross section represented by a circular domain with four points over the pipe wall representing heating cables. The fluid is considered stagnant, homogeneous, isotropic and with constant thermo-physical properties. The mathematical formulation governing the direct problem was solved with the finite volume method and for the solution of the state estimation problem

  4. Research on central heating system control strategy based on genetic algorithm

    Science.gov (United States)

    Ding, Sa; Yang, Jianhua; Lu, Wei; Duan, Zhipeng

    2017-03-01

    The central heating is a major way of warming in northeast China in winter, however, the traditional heating method is inefficient, intensifying the energy consumption. How to improve the heating efficiency and reduce energy waste attracts more and more attentions in our country. In this paper, the mathematical model of heat transfer station temperature control system was established based on the structure of central heating system. The feedforward-feedback control strategy was used to overcome temperature fluctuations caused by the pressurized heating exchange system. The genetic algorithm was used to optimize the parameters of PID controller and simulation results demonstrated that central heating temperature achieved well control effect and meet stabilization requirements.

  5. Development of a heat pump thermal control system for spacecraft

    Science.gov (United States)

    Ogushi, T.; Murakami, M.; Tanaka, N.; Koda, T.; Hirai, T.

    This paper describes a concept of a thermal control system that has three operating modes, i.e., heat pump operation, liquid-pumped two-phase fluid loop operation, and their combination. The system is controlled to maintain desired temperature levels of payloads in the presence of wide fluctuation of thermal loads. The way of system-control and the key elements, such as a cold plate, an accumulator, and a space-use compressor are investigated. Boiling heat transfer coefficient of two-phase flow going upward or downward in a vertical evaporator pipe is investigated experimentally for predicting the coefficient in the cold plate in reduced gravity. The empirical results indicate that annular flow is dominant flow regime in space and the heat transfer coefficient is predictable from the correlation by Chen. A prototype oil-free compressor for space use is constructed, and the performance and durability are experimentally investigated. Sufficient performance and more than 2500 hours of continuous operation was obtained.

  6. Computer-assisted animation of volumetric objects

    Science.gov (United States)

    Ten, Sergey V.; Savchenko, Andrei V.; Pasko, Alexander A.; Savchenko, Vladimir V.

    1996-03-01

    Generation of animation sequence of a deformed volumetric object on networked workstations is discussed. We use several deformation types: space mapping controlled by points linked to features of an object, deformation with an algebraic sum and metamorphosis. These deformations are directly applied to interpolated volume data with following polygonization of an isosurface for visualization.

  7. MODELING OF THE HEAT PUMP STATION CONTROLABLE LOOP OF AN INTERMEDIATE HEAT-TRANSFER AGENT (Part II

    Directory of Open Access Journals (Sweden)

    Sit M.L.

    2011-08-01

    Full Text Available It is studied the model of the heat pump station controllable loop of an intermediate heat-transfer agent for the use in wineries. There are demonstrated transients after the disturbing action of the temperature on the input of cooling jacket of the fermentation stirred tank. There are compared different control laws of the object.

  8. Microprocessor control of a ground water heat pump. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

    This project was a demonstration of the energy savings available to a small well-insulated facility when a properly designed heat pump is operated against a source of constant temperature ground water or pond water. To date, we have assembled the electronic logging devices required to prove the resultant savings. Data to date, (15 November, 1980) is sparse as we are just entering a full heating season. It is expected that a complete data log will be submitted next spring. Initial energy savings computations follow - the system efficiency is impressive. A typical winter day savings is about $24.00 or $720.00 monthly. The system utilizes the 55/sup 0/F ground water directly for summer cooling. The summer savings are estimated to be about $18.00/day or $540.00 monthly. Circuits and diagrams of the microprocessor control system and data logger are presented. Some sample data are included. (WHK)

  9. Active Disturbance Rejection Control of a Heat Integrated Distillation Column

    DEFF Research Database (Denmark)

    Al-Kalbani, Fahad; Zhang, Jie; Bisgaard, Thomas

    2016-01-01

    Heat integrated distillation column (HiDC) is the most energy efficient distillation approach making efficient utilization of internal heat integration through heat pump. The rectifying section acts as a heat source with high pressure, while the stripping section operates as a heat sink with low...

  10. Control systems for ITER diagnostics, heating and current drive

    Energy Technology Data Exchange (ETDEWEB)

    Simrock, Stefan, E-mail: stefan.simrock@iter.org

    2016-11-15

    The ITER Diagnostic, Heating and Current Drive systems might appear, on the face of it, to have very different control requirements. There are approximately 45 diagnostic systems, including magnetic sensors for plasma position and shape determination, imaging systems in the IR and visible, Thompson scattering for electron temperature and density, neutron detectors and collective scattering for alpha particle density and energy distribution. The H&CD systems encompass Electron Cyclotron Heating, using 24 1MW, 170 GHz gyrotrons and 5 steerable launchers to deliver 20 MW to the plasma, Ion Cyclotron Heating, using 8 3MW, 40–55 MHz sources and two multi-element launchers to deliver 20 MW to the plasma, and 2 Negative Ion Neutral Beam Injectors, each of which can deliver up to 16.5 MW of 1 MeV beams to the plasma. Although there are substantial differences in the needs for protection, when handling multi-MW heating systems, and in data throughput for many diagnostics, the formal processes needed to translate system requirements into Instrumentation and Control are identical. Due to the distributed procurement of ITER sub-systems and the need to integrate as painlessly as possible to CODAC, the formal processes, together with a substantial degree of standardization, are even more than usually essential. Starting from the technical, safety and protection, integration and operation requirements, a loop of functional analysis and signal listing is used to generate the controller configuration and the conceptual architecture. These elements in their turn lead to the physical and software design. The paper will describe the formal processes of control system design and the methods used by the ITER project to achieve the standardization of systems engineering practices. These have been applied to several use-cases covering all operation relevant phases such as plasma operation, maintenance, testing and conditioning. There are a number of running contracts that are developing

  11. Control of heat transfer in engine coolers by Lorentz forces

    Science.gov (United States)

    Karcher, C.; Kühndel, J.

    2016-09-01

    In engine coolers of off-highway vehicles convective heat transfer at the coolant side is a limiting factor of both efficiency and performance density of the cooler. Here, due to design restrictions, backwater areas and stagnation regions appear that are caused by flow deflections and cross-sectional expansions. As appropriate coolants, mixtures of water and glysantine are commonly used. Such coolants are characterized by their electrical conductivity of some S/m. This gives rise to control coolant flow and therefore convective heat transfer by means of Lorentz forces. These body forces are generated within the weakly conducting fluid by the interactions of an electrical current density and a localized magnetic field both of which being externally superimposed. In application this may be achieved by inserting electrodes in the cooler wall and a corresponding arrangement of permanent magnets. In this paper we perform numerical simulations of such magnetohydrodynamic flow in three model geometries that are frequently apparent in engine cooling applications: Carnot-Borda diffusor, 90° bend, and 180° bend. The simulations are carried out using the software package ANSYS Fluent. The present study demonstrates that, depending on the electromagnetic interaction parameter and the specific geometric arrangement of electrodes and magnetic field, Lorentz forces are suitable to break up eddy waters and separation zones and are thus significantly increasing convective heat transfer in these areas. Furthermore, the results show that due to the action of the Lorentz forces the hydraulic pressure losses can be reduced.

  12. Controlling the heating mode of heat pumps with the TRIANA three step methodology

    NARCIS (Netherlands)

    Toersche, Hermen; Bakker, Vincent; Molderink, Albert; Nykamp, Stefan; Hurink, Johann L.; Smit, Gerardus Johannes Maria

    2012-01-01

    Heat pump based heating systems are increasingly becoming an economic and efficient alternative for domestic gas heating systems. Concentrations of heat pump installations do consume large amounts of electricity, causing significant grid distribution and stability issues when the diversity factor is

  13. Method for reducing excess heat supply experienced in typical Chinese district heating systems by achieving hydraulic balance and improving indoor air temperature control at the building level

    DEFF Research Database (Denmark)

    Zhang, Lipeng; Gudmundsson, Oddgeir; Thorsen, Jan Eric

    2016-01-01

    A common problem with Chinese district heating systems is that they supply more heat than the actual heat demand. The reason for this excess heat supply is the general failure to use control devices to adjust the indoor temperature and flow in the building heating systems in accordance with the a.......03 kg NOx per heating square meter for a typical case in Harbin.......A common problem with Chinese district heating systems is that they supply more heat than the actual heat demand. The reason for this excess heat supply is the general failure to use control devices to adjust the indoor temperature and flow in the building heating systems in accordance...... with the actual heat demand. This results in 15-30% of the total supplied heat being lost. This paper proposes an integrated approach that aims to reduce the excess heat loss by introducing pre-set thermostatic radiator valves combined with automatic balancing valves. Those devices establish hydraulic balance...

  14. Control of distributed heat transfer mechanisms in membrane distillation plants

    KAUST Repository

    Laleg-Kirati, Taous-Meriem

    2017-01-05

    Various examples are provided that are related to boundary control in membrane distillation (MD) processes. In one example, a system includes a membrane distillation (MD) process comprising a feed side and a permeate side separated by a membrane boundary layer; and processing circuitry configured to control a water production rate of the MD process based at least in part upon a distributed heat transfer across the membrane boundary layer. In another example, a method includes determining a plurality of estimated temperature states of a membrane boundary layer separating a feed side and a permeate side of a membrane distillation (MD) process; and adjusting inlet flow rate or inlet temperature of at least one of the feed side or the permeate side to maintain a difference temperature along the membrane boundary layer about a defined reference temperature based at least in part upon the plurality of estimated temperature states.

  15. Driving Fast Flows with Volumetric Current Drive

    Science.gov (United States)

    Milhone, Jason; Endrizzi, D.; Flanagan, K.; Nornberg, M. D.; Peterson, E. E.; Forest, C. B.

    2017-10-01

    Volumetric current drive has been shown to be an efficient method for driving fast flows with high Rm for studying the onset of flow-driven plasma instabilities. High performance plasmas are produced with 20 kW of electron cyclotron heating (ECH) and thermally emissive lanthanum hexaboride cathodes. Plasma flow is achieved by injecting current through the plasma across an externally applied weak magnetic field setting up a J × B body force on the plasma volume. Two scenarios for volumetric current drive have been demonstrated. The first injects current across a weak uniform axial magnetic field driving a Keplerian-like flow for magneto-rotational instability (MRI) studies. The second injects current across a weak quadrupole magnetic field for driving a von Karman-like flow for dynamo studies. First results measuring velocity and ion temperature profiles measured by a Fabry-Perot interferometer are shown. Detailed mach probe flow measurements show stronger flow shear in volumetric current drive compared to previous edge-driven plasma flow experiments. Worked funded by NSF and DOE.

  16. Earliest Deadline Control of a Group of Heat Pumps with a Single Energy Source

    Directory of Open Access Journals (Sweden)

    Jiří Fink

    2016-07-01

    Full Text Available In this paper, we develop and investigate the optimal control of a group of 104 heat pumps and a central Combined Heat and Power unit (CHP. The heat pumps supply space heating and domestic hot water to households. Each house has a buffer for domestic hot water and a floor heating system for space heating. Electricity for the heat pumps is generated by a central CHP unit, which also provides thermal energy to a district heating system. The paper reviews recent smart grid control approaches for central and distributed levels. An online algorithm is described based on the earliest deadline first theory that can be used on the aggregator level to control the CHP and to give signals to the heat pump controllers if they should start or should wait. The central controller requires only a limited amount of privacy-insensitive information from the heat pump controllers about their deadlines, which the heat pump controllers calculate for themselves by model predictions. In this way, a robust heat pump and CHP control is obtained, which is able to minimize energy demand and results in the desired thermal comfort for the households. The simulations demonstrate fast computation times due to minor computational and communication overheads.

  17. Heat stress related dairy cow mortality during heat waves and control periods in rural Southern Ontario from 2010-2012.

    Science.gov (United States)

    Bishop-Williams, Katherine E; Berke, Olaf; Pearl, David L; Hand, Karen; Kelton, David F

    2015-11-27

    Heat stress is a physiological response to extreme environmental heat such as heat waves. Heat stress can result in mortality in dairy cows when extreme heat is both rapidly changing and has a long duration. As a result of climate change, heat waves, which are defined as 3 days of temperatures of 32 °C or above, are an increasingly frequent extreme weather phenomenon in Southern Ontario. Heat waves are increasing the risk for on-farm dairy cow mortality in Southern Ontario. Heat stress indices (HSIs) are generally based on temperature and humidity and provide a relative measure of discomfort which can be used to predict increased risk of on-farm dairy cow mortality. In what follows, the heat stress distribution was described over space and presented with maps. Similarly, on-farm mortality was described and mapped. The goal of this study was to demonstrate that heat waves and related HSI increases during 2010-2012 were associated with increased on-farm dairy cow mortality in Southern Ontario. Mortality records and farm locations for all farms registered in the CanWest Dairy Herd Improvement Program in Southern Ontario were retrieved for 3 heat waves and 6 three-day control periods from 2010 to 2012. A random sample of controls (2:1) was taken from the data set to create a risk-based hybrid design. On-farm heat stress was estimated using data from 37 weather stations and subsequently interpolated across Southern Ontario by geostatistical kriging. A Poisson regression model was applied to assess the on-farm mortality in relation to varying levels of the HSI. For every one unit increase in HSI the on-farm mortality rate across Southern Ontario increases by 1.03 times (CI95% (IRR) = (1.025,1.035); p = ≤ 0.001). With a typical 8.6 unit increase in HSI from a control period to a heat wave, mortality rates are predicted to increase by 1.27 times. Southern Ontario was affected by heat waves, as demonstrated by high levels of heat stress and increased on-farm mortality

  18. A comparison of substantia nigra T1 hyperintensity in Parkinson's disease dementia, Alzheimer's disease and age-matched controls: Volumetric analysis of neuromelanin imaging

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Won Jin; Park, Ju Yeon; Yun, Won Sung; Jeon, Ji Yeong; Moon, Yeon Sil; Kim, Hee Jin; Han, Seol Heui [Konkuk University School of Medicine, Seoul (Korea, Republic of); Kwak, Ki Chang; Lee, Jong Min [Dept. of Biomedical Engineering, Hanyang University, Seoul (Korea, Republic of)

    2016-09-15

    Neuromelanin loss of substantia nigra (SN) can be visualized as a T1 signal reduction on T1-weighted high-resolution imaging. We investigated whether volumetric analysis of T1 hyperintensity for SN could be used to differentiate between Parkinson's disease dementia (PDD), Alzheimer's disease (AD) and age-matched controls. This retrospective study enrolled 10 patients with PDD, 18 patients with AD, and 13 age-matched healthy elderly controls. MR imaging was performed at 3 tesla. To measure the T1 hyperintense area of SN, we obtained an axial thin section high-resolution T1-weighted fast spin echo sequence. The volumes of interest for the T1 hyperintense SN were drawn onto heavily T1-weighted FSE sequences through midbrain level, using the MIPAV software. The measurement differences were tested using the Kruskal-Wallis test followed by a post hoc comparison. A comparison of the three groups showed significant differences in terms of volume of T1 hyperintensity (p < 0.001, Bonferroni corrected). The volume of T1 hyperintensity was significantly lower in PDD than in AD and normal controls (p < 0.005, Bonferroni corrected). However, the volume of T1 hyperintensity was not different between AD and normal controls (p = 0.136, Bonferroni corrected). The volumetric measurement of the T1 hyperintensity of SN can be an imaging marker for evaluating neuromelanin loss in neurodegenerative diseases and a differential in PDD and AD cases.

  19. Central model predictive control of a group of domestic heat pumps, case study for a small district

    NARCIS (Netherlands)

    van Leeuwen, Richard Pieter; Fink, J.; Smit, Gerardus Johannes Maria; Helfert, Markus; Krempels, Karl-Heinz; Donnellan, Brian; Klein, Cornel

    2015-01-01

    In this paper we investigate optimal control of a group of heat pumps. Each heat pump provides space heating and domestic hot water to a single household. Besides a heat pump, each house has a buffer for domestic hot water and a floor heating system for space heating. The paper describes models and

  20. On the controllability and energy sensitivity of heat-integrated desiccant adsorption dryers

    NARCIS (Netherlands)

    Atuonwu, J.C.; Straten, van G.; Deventer, van H.C.; Boxtel, van A.J.B.

    2012-01-01

    This work studies the controllability of heat-integrated zeolite adsorption dryers. Mean product moisture content, temperature and vitamin C concentration (representative of product quality) are considered as controlled variables. Set-point tracking and disturbance rejection controllability metrics

  1. Economic Model Predictive Control for Hot Water Based Heating Systems in Smart Buildings

    DEFF Research Database (Denmark)

    Awadelrahman, M. A. Ahmed; Zong, Yi; Li, Hongwei

    2017-01-01

    This paper presents a study to optimize the heating energy costs in a residential building with varying electricity price signals based on an Economic Model Predictive Controller (EMPC). The investigated heating system consists of an air source heat pump (ASHP) incorporated with a hot water tank...

  2. Integration of Heat Pumps in Distribution Grids: Economic Motivation for Grid Control

    NARCIS (Netherlands)

    Nykamp, Stefan; Molderink, Albert; Bakker, Vincent; Toersche, Hermen; Hurink, Johann L.; Smit, Gerardus Johannes Maria

    2012-01-01

    Electric heat pumps combined with heat buffers are important elements in smart grids since they together allow to shift the consumption of electricity in time. In this paper the effects of different control algorithms for heat pumps on the investment costs for distribution grids are investigated.

  3. Integration of heat pumps in distribution grids: economic motivation for grid control

    NARCIS (Netherlands)

    Nykamp, Stefan; Molderink, Albert; Bakker, Vincent; Toersche, Hermen; Hurink, Johann L.; Smit, Gerardus Johannes Maria

    2012-01-01

    Electric heat pumps combined with heat buffers are important elements in smart grids since they together allow to shift the consumption of electricity in time. In this paper the effects of different control algorithms for heat pumps on the investment costs for distribution grids are investigated.

  4. Control and prevention of ice formation and accretion on heat exchangers for ventilation systems

    DEFF Research Database (Denmark)

    Rahimi, Maral; Afshari, Alireza

    2015-01-01

    In cold climates, the application of mechanical ventilation systems with heat recovery like are airto-air exchangers is used for reducing energy consumption for heating buildings by transferring heat exhausted air to supply air. However, increase efficiency of heat exchanger results in lower...... exhaust air temperatures and Ice formation on heat exchanger fins, which can cause problem and is not favourable. Therefore, prevention and control of ice formation on heat exchangers is necessary. The existing methods are divided into two different methods: active and passive ice control methods....... The active methods are e.g. bypass, recirculation, preheating. The passive methods relate to the surface characteristics of the heat exchanger fins as they have effect on ice formation in initial phase. All these methods have varying levels of success, cost, and effectiveness, which are depending on the heat...

  5. Influence of heat cost allocation on occupants' control of indoor environment in 56 apartments

    DEFF Research Database (Denmark)

    Andersen, Søren; Andersen, Rune Korsholm; Olesen, Bjarne W.

    2016-01-01

    and heat cost savings at the expense of thermal comfort and air quality. The differences in average temperature, average CO2 concentration and average vapour pressure were 2.8 °C, 161 ppm, and 93 Pa, respectively between apartments with collective and individual heat cost allocation....... of this paper was to study the indoor environment in buildings with collective and individual heat cost allocation plans, to investigate how the heat cost allocation influenced occupant behaviour and how occupants controlled the indoor environment. The effects of the heat cost allocation type were studied......-structured interviews showed a strong influence of the heat cost allocation plan on the occupants' control strategies. Occupants whose heating bills were based on floor area focused on a healthy and comfortable indoor environment. Occupants whose heating bills were based on meter readings focused on energy conservation...

  6. Contribution of domestic heating systems to smart grid control

    DEFF Research Database (Denmark)

    Tahersima, Fatemeh; Stoustrup, Jakob; Meybodi, Soroush Afkhami

    2011-01-01

    . We have investigated how much power imbalance could be compensated, provided that a certain, yet user adjustable, level of residents' thermal comfort is satisfied. It is shown that the large heat capacity of the concrete floor alleviates undesired temperature fluctuations. Therefore, incorporating......How and to what extent, domestic heating systems can be helpful in regaining power balance in a smart grid, is the question to be answered in this paper. Our case study is an under-floor heating system supplied with a geothermal heat pump which is driven by electrical power from the grid. The idea...

  7. A SIMPLIFIED PREDICTIVE CONTROL FOR A SHELL AND TUBE HEAT EXCHANGER

    OpenAIRE

    S.RAJASEKARAN,; Dr.T.KANNADASAN

    2010-01-01

    In this paper a simplified predictive control design is applied for the controlling a temperature of a fluid stream using the shell and tube heat exchanger. The predictive control design based on Dynamic Matrix Control (DMC) involves the complicated inversion computation for higher dimensional matrix. Using DMC for controlling a temperature of the shell and tube heat exchanger, there is still a need for optimization of conversation of energy. The simplified predictive control is based on DMC,...

  8. Heat

    CERN Document Server

    Lawrence, Ellen

    2016-01-01

    Is it possible to make heat by rubbing your hands together? Why does an ice cube melt when you hold it? In this title, students will conduct experiments to help them understand what heat is. Kids will also investigate concepts such as which materials are good at conducting heat and which are the best insulators. Using everyday items that can easily be found around the house, students will transform into scientists as they carry out step-by-step experiments to answer interesting questions. Along the way, children will pick up important scientific skills. Heat includes seven experiments with detailed, age-appropriate instructions, surprising facts and background information, a "conclusions" section to pull all the concepts in the book together, and a glossary of science words. Colorful, dynamic designs and images truly put the FUN into FUN-damental Experiments.

  9. Description of emission control using fluidized-bed, heat-exchange technology

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, G.J.; Grogan, P.J.

    1980-06-01

    Environmental effects of fluidized-bed, waste-heat recovery technology are identified. The report focuses on a particular configuration of fluidized-bed, heat-exchange technology for a hypothetical industrial application. The application is a lead smelter where a fluidized-bed, waste-heat boiler (FBWHB) is used to control environmental pollutants and to produce steam for process use. Basic thermodynamic and kinetic information for the major sulfur dioxide (SO/sub 2/) and NO/sub x/ removal processes is presented and their application to fluidized-bed, waste heat recovery technology is discussed. Particulate control in fluidized-bed heat exchangers is also discussed.

  10. Implementation of Fuzzy Logic Based Temperature-Controlled Heat ...

    African Journals Online (AJOL)

    This paper discusses the performance analysis of a heat exchanger using simulations for an Adaptive Network based Fuzzy Inference System toolbox developed with MATLAB. The plant transfer function is derived based on process reaction curve obtained from a heat exchanger pilot plant and then the model is used to ...

  11. Linear programming control of a group of heat pumps

    NARCIS (Netherlands)

    Fink, J.; van Leeuwen, Richard Pieter; Hurink, Johann L.; Smit, Gerardus Johannes Maria

    2015-01-01

    For a new district in the Dutch city Meppel, a hybrid energy concept is developed based on bio-gas co-generation. The generated electricity is used to power domestic heat pumps which supply thermal energy for domestic hot water and space heating demand of households. In this paper, we investigate

  12. Demand Controlled Economizer Cycles: A Direct Digital Control Scheme for Heating, Ventilating, and Air Conditioning Systems,

    Science.gov (United States)

    1984-05-01

    includes a heating coil and thermostatic control to maintain the air in this path at an elevated temperature, typically around 80 degrees Farenheit (80 F...1238 Aug 1 1236 1237 52 1074 1126 50 1033 1083 Sep 8 8 5W 862 7T 600 678 75 603 7r Oct 51 400 451 119 204 323 115 207 322 ov 64 123 287 187 71 258

  13. Evaluation of the workers exposure to heat and presenting intervention to control heat stress in profile factory

    Directory of Open Access Journals (Sweden)

    Motamedzade Majid

    2014-10-01

    Full Text Available Background & Objectives : Exposure to heat is a significant problem in the Industries. The present study aimed at the evaluation of thermal risk, measurement of heat stress index, and proposing a plan for heat control in cutting and welding units in profile factory . Methods : The data of study was analyzed through the measurement of physical parameters with digital WBGT device and silvered Kata thermometer. Workers’ thermal comfort was calculated based on predicted mean voted (PMV and predicted percentage of dissatisfied (PPD with regard to the computed parameters. In order to control heat stress, an aluminum-insulated wall was used and airflow velocity was increased in cutting and welding units. Results : The results of the WBGT index before and after the intervention using the shield were 30.8° C and 23.2° C, and by increasing airflow velocity were 30° C and 29.5° C respectively. In addition, the obtained results for PMV and PPD by using the shield were 1.38 and %44, and by increasing airflow velocity they were %90 and 2.56 respectively. The results confirmed by using the shield the measured WBGT index was lower than the occupational exposure limit (28 ◦ c. Conclusion : The results showed that by appropriate designing and using control methods, such as insulation shield and increased airflow velocity, optimal thermal comfort based on national heat exposure limits could be reached .

  14. Improving the Efficiency of the Heat Pump Control System of Carbon Dioxide Heat Pump with Several Evaporators and Gas Coolers

    Directory of Open Access Journals (Sweden)

    Sit M.L.

    2016-12-01

    Full Text Available The problem of coordination of the values of the refrigerant flow through the evaporators and gas coolers of the heat pump for the simultaneous production of heat and cold is studied. The compensation of the variations of the total flow through the evaporators is implemented using the variation of the capacity of the compressor and a corresponding change in flow through the auxiliary gas cooler of the heat pump. Control system of this gas cooler is constructed using the invariance principle of the output value (outlet temperature of the heated agent with respect to perturbations on the control channel (the refrigerant flow through the gas cooler. Principle of dual-channel compensation of the disturbance and advancing signal on input of control valve of the refrigerant through the gas cooler is ensured. Due to proposed solution, the intensity of the disturbances on the flow of refrigerant is reduced. Due to proposed technical solution power consumed by the heat pump compressor drive under transients is decreased.

  15. Quantifying demand flexibility of power-to-heat and thermal energy storage in the control of building heating systems

    DEFF Research Database (Denmark)

    Finck, Christian; Li, Rongling; Kramer, Rick

    2018-01-01

    In the future due to continued integration of renewable energy sources, demand-side flexibility would be required for managing power grids. Building energy systems will serve as one possible source of energy flexibility. The degree of flexibility provided by building energy systems is highly...... restricted by power-to-heat conversion such as heat pumps and thermal energy storage possibilities of a building. To quantify building demand flexibility, it is essential to capture the dynamic response of the building energy system with thermal energy storage. To identify the maximum flexibility a building......’s energy system can provide, optimal control is required. In this paper, optimal control serves to determine in detail demand flexibility of an office building equipped with heat pump, electric heater, and thermal energy storage tanks. The demand flexibility is quantified using different performance...

  16. Induction heating processes optimization a general optimal control approach

    CERN Document Server

    Favennec, Y; Bay, F

    2003-01-01

    A general automatic optimization procedure coupled to a finite element induction heating process simulation has been developed. The mathematical model and the numerical methods are presented along with results validating the model. The first part of this paper presents the direct induction heating mathematical model, the related main numerical choices and especially the ultra-weak coupling procedure. The general optimization problem is then presented with the full detailed transposition of the ultra-weak coupling procedure to the adjoint problem. Numerical results provided at the end prove the efficiency and robustness of the adjoint model in optimizing induction heating processes.

  17. Control Strategies to Conserve Energy in All-Air Heating Ventilation and Air Conditioning Systems.

    Science.gov (United States)

    1979-05-14

    York, ASHRAE, Inc. American Society of Heating, Refrigerating and Air- Conditioning Engineers. "Standards for Natural and Mechanical Ventilation ...or REPoRT a P61mO0 COVERED 1 Control Strategies to Conserve Energy in All-Air Heating Ventilation and Air Conditioning THESIS 14Systems o ~~~sGOG...Morrison, William James (M. S., Civil Engineering) Control Strategies to Conserve Energy in All-Air Heating Ventilation and Air Conditioning Systems Report

  18. Volumetric graphics in liquid using holographic femtosecond laser pulse excitations

    Science.gov (United States)

    Kumagai, Kota; Hayasaki, Yoshio

    2017-06-01

    Much attention has been paid to the development of three-dimensional volumetric displays in the fields of optics and computer graphics, and it is a dream of we display researchers. However, full-color volumetric displays are challenging because many voxels with different colors have to be formed to render volumetric graphics in real three-dimensional space. Here, we show a new volumetric display in which microbubble voxels are three-dimensionally generated in a liquid by focused femtosecond laser pulses. Use of a high-viscosity liquid, which is the key idea of this system, slows down the movement of the microbubbles, and as a result, volumetric graphics can be displayed. This "volumetric bubble display" has a wide viewing angle and simple refresh and requires no addressing wires because it involves optical access to transparent liquid and achieves full-color graphics composed on light-scattering voxels controlled by illumination light sources. In addition, a bursting of bubble graphics system using an ultrasonic vibrator also has been demonstrated. This technology will open up a wide range of applications in three-dimensional displays, augmented reality and computer graphics.

  19. Rapid mapping of volumetric errors

    Energy Technology Data Exchange (ETDEWEB)

    Krulewich, D.; Hale, L.; Yordy, D.

    1995-09-13

    This paper describes a relatively inexpensive, fast, and easy to execute approach to mapping the volumetric errors of a machine tool, coordinate measuring machine, or robot. An error map is used to characterize a machine or to improve its accuracy by compensating for the systematic errors. The method consists of three steps: (1) modeling the relationship between the volumetric error and the current state of the machine; (2) acquiring error data based on length measurements throughout the work volume; and (3) optimizing the model to the particular machine.

  20. Temperature control for kinetic refolding of heat-denatured ovalbumin.

    Science.gov (United States)

    Tani, F; Shirai, N; Onishi, T; Venelle, F; Yasumoto, K; Doi, E

    1997-07-01

    The folding of heat-denatured ovalbumin, a non-inhibitory serpin with a molecular size of 45 kDa, was examined. Ovalbumin was heat-denatured at 80 degrees C under nonreducing conditions at pH 7.5 and then cooled either slowly or rapidly. Slow cooling allowed the heat-denatured ovalbumin to refold to its native structure with subsequent resistance to digestion by trypsin. Upon rapid cooling, by contrast, the heat-denatured molecules assumed the metastable non-native conformations that were susceptible to trypsin. The non-native species were marginally stable for several days at a low temperature, but the molecules were transformed slowly into the native conformation. Considering data from size-exclusion chromatography and from analyses of CD, intrinsic tryptophan fluorescence, and adsorption of the dye 1-anilinonaphthalene-8-sulfonate, we postulated that the non-native species that accumulated upon rapid cooling were compact but structureless globules with disordered side chains collectively as a folding intermediate. Temperature-jumped CD experiments revealed biphasic kinetics for the refolding process of heat-denatured ovalbumin, with the features of increasing and subsequently decreasing amplitude of the rapid and the slow phases, respectively, with the decrease in folding temperature. The temperature dependence of the refolding kinetics indicated that the yield of renaturation was maximal at about 55 degrees C. These findings suggested the kinetic partitioning of heat-denatured ovalbumin between alternative fates, slow renaturation to the native state and rapid collapse to the metastable intermediate state. Analysis of disulfide pairing revealed the formation of a scrambled form with non-native disulfide interactions in both the heat-denatured state and the intermediate state that accumulated upon rapid cooling, suggesting that non-native disulfide pairing is responsible for the kinetic barriers that retard the correct folding of ovalbumin.

  1. Modeling and dynamic control simulation of unitary gas engine heat pump

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Yang [Department of Thermal Energy Engineering, Tianjin University, Tianjin 300072 (China)], E-mail: Zhaoyang@tju.edu.cn; Haibo Zhao; Zheng Fang [Department of Thermal Energy Engineering, Tianjin University, Tianjin 300072 (China)

    2007-12-15

    Based on the dynamic model of the gas engine heat pump (GEHP) system, an intelligent control simulation is presented to research the dynamic characteristics of the system in the heating operation. The GEHP system simulation model consists of eight models for its components including a natural gas engine, a compressor, a condenser, an expansion valve, an evaporator, a cylinder jacket heat exchanger, an exhaust gas heat exchanger and an auxiliary heater. The intelligent control model is composed of the prediction controller model and the combined controller model. The Runge-Kutta Fehlberg fourth-fifth order algorithms are used to solve the differential equations. The results show that the model is very effective in analyzing the effects of the control system, and the steady state accuracy of the intelligent control scheme is higher than that of the fuzzy controller.

  2. Advanced control for ground source heat pump systems

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Patrick [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gehl, Anthony C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Liu, Xiaobing [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-09-01

    Ground source heat pumps (GSHP), also known as geothermal heat pumps (GHP), are proven advanced HVAC systems that utilize clean and renewable geothermal energy, as well as the massive thermal storage capacity of the ground, to provide space conditioning and water heating for both residential and commercial buildings. GSHPs have higher energy efficiencies than conventional HVAC systems. It is estimated, if GSHPs achieve a 10% market share in the US, in each year, 0.6 Quad Btu primary energy consumption can be saved and 36 million tons carbon emissions can be avoided (Liu et al. 2017). However, the current market share of GSHPs is less than 1%. The foremost barrier preventing wider adoption of GSHPs is their high installation costs. To enable wider adoption of GSHPs, the costeffectiveness of GSHP applications must be improved.

  3. Flow distribution control characteristics in marine gas turbine waste-heat recovery system. Phase 2: Flow distribution control in waste-heat steam generators

    Science.gov (United States)

    Kuo, S. C.; Shu, H. T.

    1982-07-01

    The effect of flow distribution control on the design and performance of marine gas turbine waste heat steam generators was investigated. Major design requirements and critical problems associated with a waste heat steam generator were reviewed, and an existing two dimensional heat exchanger model based on the compact heat exchanger design criteria and the relaxation approach was modified and updated to estimate the waste heat steam generator performance at any inlet gas flow distribution. Performance estimates were made of the steam generator using uniform velocity distribution, and also actual flow distribution data available (at the diffuser inlet) with and without flow distribution controls, all at design and off design operating conditions of the gas turbine engine. Results indicate that the exit steam temperatures of the baseline waste heat steam generator with and without flow distribution controls would be 725 F and 450 F, respectively, for a constant design flow ratio of 7.9 lb/sec, and for a constant exit temperature of 700 F, the water flow rates would be 8.1 lb/sec and 6.6 lb/sec, respectively.

  4. Economic COP Optimization of a Heat Pump with Hierarchical Model Predictive Control

    DEFF Research Database (Denmark)

    Tahersima, Fatemeh; Stoustrup, Jakob; Rasmussen, Henrik

    2012-01-01

    bills by involving feedback control in a previous study, this paper has continued the same line of argument and has investigated effects of a priori knowledge on weather forecast and electricity price profile to alleviate the total electricity cost subject to constraints on resident's thermal comfort....... The proposed control strategy is a leap forward towards balanced load control in Smart Grids where individual heat pumps in detached houses contribute to preserve load balance through intelligent electricity pricing policies.......A low-temperature heating system is studied in this paper. It consists of hydronic under-floor heating pipes and an air/ground source heat pump. The heat pump in such a setup is conventionally controlled only by feed-forwarding the ambient temperature. Having shown >10% cut-down on electricity...

  5. Elimination of Oscillations in a Central Heating System using Pump Control

    DEFF Research Database (Denmark)

    Andersen, Palle; Pedersen, Tom Søndergaard; Stoustrup, Jakob

    2000-01-01

    In central heating systems with thermostatic valve temperature control it is a well known fact that room temperature oscillations may occur when the heat demand becomes low due to the non-linear behavior of the control loop. This is not only discomforting but it also increases the energy cost...... of heating the room. Using the pump speed as an active part in control is it shown that the room temperature may be stabilized in a wider interval of heat demand. The idea is to control the pump speed in a way that keeps the thermostatic valve within a suitable operating area using an estimate of the valve...... position. The position is estimated from the pump terminals, using the pump flow and the pump differential pressure. The concept is tested on a small central heating test bench. The results show that it is possible to stabilize the room temperature even at part load conditions...

  6. Numerical simulation of side heating for controlling angular ...

    Indian Academy of Sciences (India)

    Side heating; finite element analysis; element birth and death method; manual metal arc welding; angular distortions. ... Element birth and death technique is used to simulate the filler material deposition. ... Institute of Engineering Education and Research, Nashik (Affiliated to University of Pune), Nashik, 422 003, India ...

  7. Numerical simulation of side heating for controlling angular ...

    Indian Academy of Sciences (India)

    is the non-uniform heating of material during the welding process, which in turn produces plastic strains and residual stress owing to the mismatch of thermal expansions in the weld and sur- rounding material. The residual stress and plastic strain are inherent in the welding process: they interact to produce distortion in ...

  8. Hydronic Heating Retrofits for Low-Rise Multifamily Buildings - Phase 1: Boiler Control Replacement and Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Dentz, J.; Henderson, H.

    2012-04-01

    The ARIES Collaborative, a Department of Energy Building America research team, partnered with NeighborWorks America affiliate Homeowners' Rehab Inc. (HRI) of Cambridge, MA to implement and study improvements to the heating system in one of the non-profit's housing developments. The heating control systems in the 42-unit Columbia CAST housing development were upgraded in an effort projected to reduce heating costs by 15 to 25 percent.

  9. Control apparatus and method for efficiently heating a fuel processor in a fuel cell system

    Science.gov (United States)

    Doan, Tien M.; Clingerman, Bruce J.

    2003-08-05

    A control apparatus and method for efficiently controlling the amount of heat generated by a fuel cell processor in a fuel cell system by determining a temperature error between actual and desired fuel processor temperatures. The temperature error is converted to a combustor fuel injector command signal or a heat dump valve position command signal depending upon the type of temperature error. Logic controls are responsive to the combustor fuel injector command signals and the heat dump valve position command signal to prevent the combustor fuel injector command signal from being generated if the heat dump valve is opened or, alternately, from preventing the heat dump valve position command signal from being generated if the combustor fuel injector is opened.

  10. HEAT PUMP STATION WITH CARBON DIOXIDE AS A WORKING FLUID ENERGY EFFICIENCY GROWTH IN COMBINED DISTRICT HEATING SYSTEM DUE TO ITS CONTROL SYSTEM OPTIMIZATION

    Directory of Open Access Journals (Sweden)

    Sit B.M.

    2008-04-01

    Full Text Available A diagram of the heat pump station (HPS for the central heat supply station of the district heating system, which gets the power from the CHP plant is examined. A block diagram of the control of the system and compressor pressure control system are examined. The description of the control laws of evaporator at the variable heat load of the HPS and control laws of the gas cooler taking into account the goal of achieving the maximum of COP of HPS is shown as well.

  11. Building America Case Study: Boiler Control Replacement for Hydronically Heated Multifamily Buildings, Cambridge, Massachusetts (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2014-11-01

    The ARIES Collaborative, a U.S. Department of Energy Building America research team, partnered with NeighborWorks America affiliate Homeowners' Rehab Inc. (HRI) of Cambridge, Massachusetts, to study improvements to the central hydronic heating system in one of the nonprofit's housing developments. The heating controls in the three-building, 42-unit Columbia Cambridge Alliance for Spanish Tenants housing development were upgraded. Fuel use in the development was excessive compared to similar properties. A poorly insulated thermal envelope contributed to high energy bills, but adding wall insulation was not cost-effective or practical. The more cost-effective option was improving heating system efficiency. Efficient operation of the heating system faced several obstacles, including inflexible boiler controls and failed thermostatic radiator valves. Boiler controls were replaced with systems that offer temperature setbacks and one that controls heat based on apartment temperature in addition to outdoor temperature. Utility bill analysis shows that post-retrofit weather-normalized heating energy use was reduced by 10%-31% (average of 19%). Indoor temperature cutoff reduced boiler runtime (and therefore heating fuel consumption) by 28% in the one building in which it was implemented. Nearly all savings were obtained during night which had a lower indoor temperature cut off (68 degrees F) than day (73 degrees F). This implies that the outdoor reset curve was appropriately adjusted for this building for daytime operation. Nighttime setback of heating system supply water temperature had no discernable impact on boiler runtime or gas bills.

  12. Model predictive control of a waste heat recovery system for automotive diesel engines

    NARCIS (Netherlands)

    Feru, E.; Willems, F.; De Jager, B.; Steinbuch, M.

    2014-01-01

    In this paper, a switching Model Predictive Control strategy is designed for an automotive Waste Heat Recovery system with two parallel evaporators. The objective is to maximize Waste Heat Recovery system output power, while satisfying safe operation under highly dynamic disturbances from the

  13. Application of a New Dynamic Heating System Model Using a Range of Common Control Strategies

    Directory of Open Access Journals (Sweden)

    Joshua Fong

    2016-06-01

    Full Text Available This research investigates the overall heating energy consumptions using various control strategies, secondary heat emitters, and primary plant for a building. Previous research has successfully demonstrated that a dynamic distributed heat emitter model embedded within a simplified third-order lumped parameter building model is capable of achieving improved results when compared to other commercially available modelling tools. With the enhanced ability to capture transient effects of emitter thermal capacity, this research studies the influence of control strategies and primary plant configurations on the rate of energy consumption of a heating system. Four alternative control strategies are investigated: zone feedback; weather-compensated; a combination of both of these methods; and thermostatic control. The plant alternative configurations consist of conventional boilers, biomass boilers, and heat pumps supporting radiator heating and underfloor heating. The performance of the model is tested on a primary school building and can be applied to any residential or commercial building with a heating system. Results show that the new methods reported offer greater detail and rigor in the conduct of building energy modelling.

  14. Hydronic Heating Retrofits for Low-Rise Multifamily Buildings: Boiler Control Replacement and Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Dentz, J.; Henderson, H.; Varshney, K.

    2014-09-01

    The ARIES Collaborative, a U.S. Department of Energy Building America research team, partnered with NeighborWorks America affiliate Homeowners' Rehab Inc. (HRI) of Cambridge, Massachusetts, to study improvements to the central hydronic heating system in one of the nonprofit's housing developments. The heating controls in the three-building, 42-unit Columbia Cambridge Alliance for Spanish Tenants housing development were upgraded. Fuel use in the development was excessive compared to similar properties. A poorly insulated thermal envelope contributed to high energy bills, but adding wall insulation was not cost-effective or practical. The more cost-effective option was improving heating system efficiency. Efficient operation of the heating system faced several obstacles, including inflexible boiler controls and failed thermostatic radiator valves. Boiler controls were replaced with systems that offer temperature setbacks and one that controls heat based on apartment temperature in addition to outdoor temperature. Utility bill analysis shows that post-retrofit weather-normalized heating energy use was reduced by 10%-31% (average of 19%). Indoor temperature cutoff reduced boiler runtime (and therefore heating fuel consumption) by 28% in the one building in which it was implemented. Nearly all savings were obtained during night which had a lower indoor temperature cut off (68 degrees F) than day (73 degrees F). This implies that the outdoor reset curve was appropriately adjusted for this building for daytime operation. Nighttime setback of heating system supply water temperature had no discernable impact on boiler runtime or gas bills.

  15. Feasibility of using phase change materials to control the heat of hydration in massive concrete structures.

    Science.gov (United States)

    Choi, Won-Chang; Khil, Bae-Soo; Chae, Young-Seok; Liang, Qi-Bo; Yun, Hyun-Do

    2014-01-01

    This paper presents experimental results that can be applied to select a possible phase change material (PCM), such as a latent heat material (LHM), to control the hydration heat in mass concrete structures. Five experimental tests (microconduction, simplified adiabatic temperature rise, heat, and compressive strength tests) were conducted to select the most desirable LHM out of seven types of inorganic PCM used in cement mortar and to determine the most suitable mix design. The results of these experimental tests were used to assess the feasibility of using PCM to reduce hydration heat in mass concrete that was examined. The experimental results show that cement mortar containing barium- [Ba(OH)2 · 8H2O] based PCM has the lowest amount of total hydration heat of the cement pastes. The barium-based PCM provides good latent heat properties that help to prevent volume change and microcracks caused by thermal stress in mass concrete.

  16. Feasibility of Using Phase Change Materials to Control the Heat of Hydration in Massive Concrete Structures

    Directory of Open Access Journals (Sweden)

    Won-Chang Choi

    2014-01-01

    Full Text Available This paper presents experimental results that can be applied to select a possible phase change material (PCM, such as a latent heat material (LHM, to control the hydration heat in mass concrete structures. Five experimental tests (microconduction, simplified adiabatic temperature rise, heat, and compressive strength tests were conducted to select the most desirable LHM out of seven types of inorganic PCM used in cement mortar and to determine the most suitable mix design. The results of these experimental tests were used to assess the feasibility of using PCM to reduce hydration heat in mass concrete that was examined. The experimental results show that cement mortar containing barium- [Ba(OH2·8H2O] based PCM has the lowest amount of total hydration heat of the cement pastes. The barium-based PCM provides good latent heat properties that help to prevent volume change and microcracks caused by thermal stress in mass concrete.

  17. Control and simulation of a HTGR-GT combined heat and power plant

    Energy Technology Data Exchange (ETDEWEB)

    Kikstra, J.F. [ECN Nuclear Research, Petten (Netherlands)

    1998-09-01

    In the Dutch INCOGEN research program, a small modular High Temperature Gas-cooled Reactor - Gas Turbine (HTGR-GT) system for Combined Heat and Power (CHP) generation was studied. In a CHP plant off-design operation is of high importance, since the heat demand can vary considerably (in particular for district heating)and at the same time has to be fulfilled at every moment. In this study two typical CHP-systems are considered: (1) coproduction of electricity and industrial steam (10 bar 220C) and (2) coproduction of electricity and hot water for district heating (supply temperature 125C). For these two systems the layout and off-design conditions giving optimum efficiency have been established. It can be concluded that the conditions in the reactor core can be held fairly constant, although optimum temperatures and flows in the system vary strongly with the heat to power ratio. For the design of a control system, the process conditions which have to be controlled and possible control input variables have been identified. Subsequently, a control structure is proposed in which both electrical and heat demand can be followed. The control system uses mainly inventory control and control of compressor inlet temperature, while during fast transients bypass-control can be used to prevent thermal stresses. In order to test different control structures, a dynamic, first principles model is under construction. The model is based on one-dimensional heat-, mass- and momentum balances, thermodynamic fluid properties and semi-empirical correlations for e.g. heat transfer and compressor performance. Principles of the system modelling are described and an example of a model of a sub-unit is given. 12 refs.

  18. Transformed Fourier and Fick equations for the control of heat and mass diffusion

    National Research Council Canada - National Science Library

    Guenneau, S; Petiteau, D; Zerrad, M; Amra, C; Puvirajesinghe, T

    2015-01-01

    We review recent advances in the control of diffusion processes in thermodynamicsand life sciences through geometric transforms in the Fourier and Fick equations,which govern heat and mass diffusion, respectively...

  19. Local Measurement of Fuel Energy Deposition and Heat Transfer Environment During Fuel Lifetime Using Controlled Calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Don W. Miller; Andrew Kauffmann; Eric Kreidler; Dongxu Li; Hanying Liu; Daniel Mills; Thomas D. Radcliff; Joseph Talnagi

    2001-12-31

    A comprehensive description of the accomplishments of the DOE grant titled, ''Local Measurement of Fuel Energy Deposition and Heat Transfer Environment During Fuel Lifetime using Controlled Calorimetry''.

  20. Control and regulation of heat pumps. A collation of present knowledge. Reglering av vaermepumpar. Kunskapssammanstaellning

    Energy Technology Data Exchange (ETDEWEB)

    Engblom, P.; Lindgren, S.; Tammisto, O.

    1986-01-01

    This report presents a collation of various systems for controlling heat pumps. Operating experience has been collected in order to investigate how various installations operate in practice. In several cases, it has not been possible to operate the heat pumps as originally planned as a result of too high a temperature in the heat sink. This has usually resulted in an inability to operate the plan in such a way as to produce heat at as low a cost as would have been the case had the plant been operating correctly. Present-day understanding of how various factors affect the selection of technically and economically correct control system for heat pump operation is not satisfactory, and so the report concludes with specific recommendations for necessary research and development work.

  1. [Air quality control systems: heating, ventilating, and air conditioning (HVAC)].

    Science.gov (United States)

    Bellucci Sessa, R; Riccio, G

    2004-01-01

    After a brief illustration of the principal layout schemes of Heating, Ventilating, and Air Conditioning (HVAC), the first part of this paper summarizes the standards, both voluntary and compulsory, regulating HVAC facilities design and installation with regard to the question of Indoor Air Quality (IAQ). The paper then examines the problem of ventilation systems maintenance and the essential hygienistic requirements in whose absence HVAC facilities may become a risk factor for people working or living in the building. Lastly, the paper deals with HVAC design strategies and methods, which aim not only to satisfy comfort and air quality requirements, but also to ensure easy and effective maintenance procedures.

  2. Turbulence Control Through Selective Surface Heating Using Microwave Radiation

    Science.gov (United States)

    2013-05-01

    air channel of wind tunnel ,(facility) , ,S S sc S tsP P P . Calibration has been performed for five positions of reference pressure probe across... big project. Here it is simply supposed that the bottom part of model (it is not shown in Fig.4.5b) is made of a radiotransparent dielectric...before the model burnout that enable only a limited number of test runs. The main drawback of the MW heating resultd from the non-uniformity of energy

  3. System design and installation for RS600 programmable control system for solar heating and cooling

    Science.gov (United States)

    1978-01-01

    Procedures for installing, operating, and maintaining a programmable control system which utilizes a F8 microprocessor to perform all timing, control, and calculation functions in order to customize system performance to meet individual requirements for solar heating, combined heating and cooling, and/or hot water systems are described. The manual discusses user configuration and options, displays, theory of operation, trouble-shooting procedures, and warranty and assistance. Wiring lists, parts lists, drawings, and diagrams are included.

  4. TECHNICAL BASIS DOCUMENT OF MARSSIM FIELD CALIBRATION FOR QUANTIFICATION OF CS-137 VOLUMETRICALLY CONTAMINTED SOILS IN THE BC CONTROLLED AREA USING A 4 BY 4 BY 16 INCH SODIUM IODIDE DETECTOR

    Energy Technology Data Exchange (ETDEWEB)

    PAPPIN JL

    2007-10-26

    The purpose of this paper is to provide the Technical Basis and Documentation for Field Calibrations of radiation measurement equipment for use in the MARSSIM Seeping Surveys of the BC Controlled Area (BCCA). The Be Controlled Area is bounded on tt1e north by (but does not include) the BCCribs & Trenches and is bounded on the south by Army Loop Road. Parts of the BC Controlled Area are posted as a Contamination Area and the remainder is posted as a Soil Contamination Area. The area is approximately 13 square miles and divided into three zones (Zone A , Zone B. and Zone C). A map from reference 1 which shows the 3 zones is attached. The MARSSIM Scoping Surveys are intended 10 better identify the boundaries of the three zones based on the volumetric (pCi/g) contamination levels in the soil. The MARSSIM Field Calibration. reference 2. of radiation survey instrumentation will determine the Minimum Detectable Concentration (MDC) and an algorithm for converting counts to pCi/g. The instrumentation and corresponding results are not intended for occupational radiation protection decisions or for the release of property per DOE Order 5400.5.

  5. NIFS joint research meeting on plasma facing components, PSI, and heat/particle control

    Energy Technology Data Exchange (ETDEWEB)

    Yamashina, T. [Hokkaido Univ., Sapporo (Japan)

    1997-10-01

    The LHD collaboration has been started in 1996. Particle and heat control is one of the categories for the collaboration, and a few programs have been nominated in these two years. A joint research meeting on PFC, PSI, heat and particle meeting was held at NIFS on June 27, 1997, in which present status of these programs were reported. This is a collection of the notes and view graphs presented in this meeting. Brief reviews and research plan of each program are included in relation to divertor erosion and sputtering, impurity generation, hydrogen recycling, edge plasma structure, edge transport and its control, heat removal, particle exhaust, wall conditioning etc. (author)

  6. Technology Solutions Case Study: Boiler Control Replacement for Hydronically Heated Multifamily Buildings, Cambridge, Massachusetts

    Energy Technology Data Exchange (ETDEWEB)

    None

    2014-11-01

    The ARIES Collaborative, a U.S. Department of Energy Building America research team, partnered with NeighborWorks America affiliate Homeowners' Rehab Inc. (HRI) of Cambridge, Massachusetts, to study improvements to the central hydronic heating system in one of the nonprofit's housing developments. The heating controls in the three-building, 42-unit Columbia Cambridge Alliance for Spanish Tenants housing development were upgraded. Fuel use in the development was excessive compared to similar properties. A poorly insulated thermal envelope contributed to high energy bills, but adding wall insulation was not cost-effective or practical. The more cost-effective option was improving heating system efficiency, which faced several obstacles, including inflexible boiler controls and failed thermostatic radiator valves. Boiler controls were replaced with systems that offer temperature setbacks and one that controls heat based on apartment temperature in addition to outdoor temperature. Utility bill analysis shows that post-retrofit weather-normalized heating energy use was reduced by 10%-31% (average of 19%). Indoor temperature cutoff reduced boiler runtime (and therefore heating fuel consumption) by 28% in the one building in which it was implemented. Nearly all savings were obtained during night which had a lower indoor temperature cut off (68°F) than day (73° F). This implies that the outdoor reset curve was appropriately adjusted for this building for daytime operation. Nighttime setback of heating system supply water temperature had no discernable impact on boiler runtime or gas bills.

  7. Experiment and simulation of temperature characteristics of intermittently-controlled ground heat exchanges

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Qing; Li, Ming; Yu, Ming [Department of Thermal Engineering, Jilin University, Changchun (China)

    2010-06-15

    Because of poor heat transfer coefficients of soil/rock, ground source heat pumps (GSHP) or underground thermal energy storage (UTES) systems always occupy a large area and need many ground heat exchangers. This initial energy investment is so heavy that it cannot be used on a large-scale. Intermittent operation can reduce the extreme temperatures around the ground heat exchangers (GHEs) and keep the temperature in reasonable range. The aim of this study is to implement an experiment and develop a dynamic model of hydronic heating systems of GSHP in order to get a more fair comparison of energy efficiency between continuously controlled and intermittently controlled systems. Factors such as thermal inertia, temperature levels and lag time are also considered to see how they affect the efficiency. It is shown that temperature variation is related to the intermittent period and that intermittence prolongs the heat transfer without reaching at an utmost temperature (operation limitation). An effectively controlled intermittent process can optimize the capacity of heat exchange units so as to achieve better application of the ground energy. Additionally, the intermittent control can decrease the number of GHEs of GSHP and UTES systems and keep better working conditions. (author)

  8. Plug and Play Process Control Applied to a District Heating System

    DEFF Research Database (Denmark)

    Knudsen, Torben; Trangbæk, Klaus; Kallesøe, Carsten Skovmose

    2008-01-01

    The general ideas within plug and play process control (PTC) are to initialize and reconfigure control systems just by plug and play. In this paper these ideas are applied to a district heating pressure control problem. First of all this serves as a concrete example of PTC, secondly some of the f...

  9. Novel Thermal Control Concepts Using Micro Heat Pipes - Spacecraft Thermal Control

    National Research Council Canada - National Science Library

    Peterson, G

    2001-01-01

    ...; Flexible polymer heat pipes have been fabricated and modeled; Theses polymer heat pipes offer a greater degree of flexibility and a potentially higher effective thermal conductivity than any previously developed...

  10. Development of a real-time system for ITER first wall heat load control

    Science.gov (United States)

    Anand, Himank; de Vries, Peter; Gribov, Yuri; Pitts, Richard; Snipes, Joseph; Zabeo, Luca

    2017-10-01

    The steady state heat flux on the ITER first wall (FW) panels are limited by the heat removal capacity of the water cooling system. In case of off-normal events (e.g. plasma displacement during H-L transitions), the heat loads are predicted to exceed the design limits (2-4.7 MW/m2). Intense heat loads are predicted on the FW, even well before the burning plasma phase. Thus, a real-time (RT) FW heat load control system is mandatory from early plasma operation of the ITER tokamak. A heat load estimator based on the RT equilibrium reconstruction has been developed for the plasma control system (PCS). A scheme, estimating the energy state for prescribed gaps defined as the distance between the last closed flux surface (LCFS)/separatrix and the FW is presented. The RT energy state is determined by the product of a weighted function of gap distance and the power crossing the plasma boundary. In addition, a heat load estimator assuming a simplified FW geometry and parallel heat transport model in the scrape-off layer (SOL), benchmarked against a full 3-D magnetic field line tracer is also presented.

  11. Evaluation of radio-frequency heating in controlling Salmonella enterica in raw shelled almonds.

    Science.gov (United States)

    Jeong, Seul-Gi; Baik, Oon-Doo; Kang, Dong-Hyun

    2017-08-02

    This study was conducted to investigate the efficacy of radio-frequency (RF) heating to reduce Salmonella enterica serovars Enteritidis, Typhimurium, and Senftenberg in raw shelled almonds compared to conventional convective heating, and the effect of RF heating on quality by measuring changes in the color and degree of lipid oxidation. Agar-grown cells of three pathogens were inoculated onto the surface or inside of raw shelled almonds using surface inoculation or the vacuum perfusion method, respectively, and subjected to RF or conventional heating. RF heating for 40s achieved 3.7-, 6.0-, and 5.6-log reductions in surface-inoculated S. Enteritidis, S. Typhimurium, and S. Senftenberg, respectively, whereas the reduction of these pathogens following convective heating for 600s was 1.7, 2.5, and 3.7 log, respectively. RF heating reduced internally inoculated pathogens to below the detection limit (0.7 logCFU/g) after 30s. However, conventional convective heating did not attain comparable reductions even at the end of treatment (600s). Color values, peroxide values, and acid values of RF-treated (40-s treatment) almonds were not significantly (P>0.05) different from those of nontreated samples. These results suggest that RF heating can be applied to control internalized pathogens as well as surface-adhering pathogens in raw almonds without affecting product quality. Copyright © 2017. Published by Elsevier B.V.

  12. Controlling Price-Responsive Heat Pumps for Overload Elimination in Distribution Systems

    DEFF Research Database (Denmark)

    Csetvei, Zsuzsa; Østergaard, Jacob; Nyeng, Preben

    2011-01-01

    This paper investigates the possibility of applying electric heat pumps with the control-by-price-concept in order to avoid overload in a local distribution system. The proposed control algorithm is based upon a centrally dispatched real-time market price, reflecting the state of a larger power...... system, and is extended with a local price control for overload elimination on the corresponding feeder. The paper presents the mathematical models of a two-node system with price-responsive heat pumps, the chosen methodology of the central price calculation, and the proposed local feedback control...

  13. On the Specific Heat Capacity of CuO Nanofluid

    OpenAIRE

    Le-Ping Zhou; Bu-Xuan Wang; Xiao-Feng Peng; Xiao-Ze Du; Yong-Ping Yang

    2010-01-01

    This paper reviews briefly the definition of heat capacity and clarifies the defined specific heat capacity and volumetric heat capacity. The specific heat capacity and volumetric heat capacity, with our measured experimental data for CuO nanofluids, are discussed as an illustrating example. The result indicates that the specific heat capacity of CuO nanofluid decreases gradually with increasing volume concentration of nanoparticles. The measurement and the prediction from the thermal equilib...

  14. The algorithms for control of heating massive material

    OpenAIRE

    Karol Kostúr; Ján Kačur

    2008-01-01

    In numerous technological processes a change on the output follows change on the input pending specific time. This time is called dead time and if this time is too large, it causes problems in the control. This contribution is aimed at analyzing the algorithms of discreet regulation of the systems with dead time. Verified were classical PID regulator and a regulator using Dead Beat method. The control was also tried with Dead interval method. The regulators were tested by simulation and in ...

  15. Optimal Operation and Stabilising Control of the Concentric Heat-Integrated Distillation Column

    DEFF Research Database (Denmark)

    Bisgaard, Thomas; Skogestad, Sigurd; Huusom, Jakob Kjøbsted

    2016-01-01

    A systematic control structure design method is applied on the concentric heat integrated distillation column (HIDiC) separating benzene and toluene. A degrees of freedom analysis is provided for identifying potential manipulated and controlled variables. Optimal operation is mapped and active...... constraints are identified for constructing the supervisory control layer. The fundamental problem of obtaining a stabilising control structure is addressed resulting in the regulatory control layer design. A supervisory control layer is devised and combined with the regulatory control layer. The control...

  16. Application of horizontal spiral coil heat exchanger for volatile organic compounds (VOC) emission control.

    Science.gov (United States)

    Deshpande, P M; Dawande, S D

    2013-04-01

    The petroleum products have wide range of volatility and are required to be stored in bulk. The evaporation losses are significant and it is a economic as well as environmental concern, since evaporative losses of petroleum products cause increased VOC in ambient air. Control of these losses poses a major problem for the storage tank designers. Ever rising cost of petroleum products further adds to the gravity of the problem. Condensation is one of the technologies for reducing volatile organic compounds emissions. Condensation is effected by condenser, which is basically a heat exchanger and the heat exchanger configuration plays an important role. The horizontal spiral coil heat exchanger is a promising configuration that finds an application in VOC control. This paper attempts to understand underlying causes of emissions and analyse the option of horizontal spiral coil heat exchanger as vent condenser.

  17. Probing Conformational Change of Bovine Serum Albumin–Dextran Conjugates under Controlled Dry Heating

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Shuqin; Li, Yunqi; Zhao, Qin; Li, Ji; Xia, Qiuyang; Zhang, Xiaoming; Huang, Qingrong (Rutgers); (Chinese Aca. Sci.); (Jiangnan)

    2015-04-29

    The time-dependent conformational change of bovine serum album (BSA) during Maillard reaction with dextran under controlled dry heating has been studied by small-angle X-ray scattering, fluorescence spectroscopy, dynamic light scattering, and circular dichroism analysis. Through the research on the radii of gyration (Rg), intrinsic fluorescence, and secondary structure, conjugates with dextran coating were found to inhibit BSA aggregation and preserve the secondary structure of native BSA against long-time heat treatment during Maillard reaction. The results suggested that the hydrophilic dextran was conjugated to the compact protein surface and enclosed it and more dextran chains were attached to BSA with the increase of the heating time. The study presented here will be beneficial to the understanding of the conformational evolution of BSA molecules during the dry-heating Maillard reaction and to the control of the protein–polysaccharide conjugate structure.

  18. Temperature Control at DBS Electrodes using Heat Sink: Experimentally Validated FEM Model of DBS lead Architecture

    Science.gov (United States)

    Elwassif, Maged M.; Datta, Abhishek; Rahman, Asif; Bikson, Marom

    2012-01-01

    There is a growing interest in the use of Deep Brain Stimulation for the treatment of medically refractory movement disorders and other neurological and psychiatric conditions. The extent of temperature increases around DBS electrodes during normal operation (joule heating and increased metabolic activity) or coupling with an external source (e.g. MRI) remains poorly understood and methods to mitigate temperature increases are being actively investigated. We developed a heat transfer finite element method simulation of DBS incorporating the realistic architecture of Medtronic 3389 leads. The temperature changes were analyzed considering different electrode configurations, stimulation protocols, and tissue properties. The heat-transfer model results were then validated using micro-thermocouple measurements during DBS lead stimulation in a saline bath. FEM results indicate that lead design (materials and geometry) may have a central role in controlling temperature rise by conducting heat. We show how modifying lead design can effectively control temperature increases. The robustness of this heat-sink approach over complimentary heat-mitigation technologies follows from several features: 1) it is insensitive to the mechanisms of heating (e.g. nature of magnetic coupling); 2) does not interfere with device efficacy; and 3) can be practically implemented in a broad range of implanted devices without modifying the normal device operations or the implant procedure. PMID:22764359

  19. Process conditions and volumetric composition in composites

    DEFF Research Database (Denmark)

    Madsen, Bo

    2013-01-01

    The obtainable volumetric composition in composites is linked to the gravimetric composition, and it is influenced by the conditions of the manufacturing process. A model for the volumetric composition is presented, where the volume fractions of fibers, matrix and porosity are calculated as a fun......The obtainable volumetric composition in composites is linked to the gravimetric composition, and it is influenced by the conditions of the manufacturing process. A model for the volumetric composition is presented, where the volume fractions of fibers, matrix and porosity are calculated...

  20. Development of a new controller for simultaneous heating and cooling of office buildings

    DEFF Research Database (Denmark)

    Maccarini, Alessandro; Afshari, Alireza; Hultmark, Göran

    2016-01-01

    This paper aims to develop a new controller to regulate the supply water temperature of a room-temperature loop integrated in a novel HVAC for office buildings. The main feature of the room-temperature loop is its ability to provide simultaneous heating and cooling by circulating water...... of the controller was tested by modelling two office rooms connected to the room-temperature loop. Standard internal heat gains and construction thermal properties were selected. To evaluate potential energy savings, the new controller was compared with the simple controller previously developed. Simulations...... with a temperature of about 22 °C. Therefore, the same supply water temperature is delivered to all the thermal zones in the building, no matter whether a single zone needs heating or cooling. In previous studies, the supply water temperature varied between 20 °C and 23 °C, according to outdoor air temperature...

  1. Linear Active Disturbance Rejection Control of Waste Heat Recovery Systems with Organic Rankine Cycles

    Directory of Open Access Journals (Sweden)

    Fang Fang

    2012-12-01

    Full Text Available In this paper, a linear active disturbance rejection controller is proposed for a waste heat recovery system using an organic Rankine cycle process, whose model is obtained by applying the system identification technique. The disturbances imposed on the waste heat recovery system are estimated through an extended linear state observer and then compensated by a linear feedback control strategy. The proposed control strategy is applied to a 100 kW waste heat recovery system to handle the power demand variations of grid and process disturbances. The effectiveness of this controller is verified via a simulation study, and the results demonstrate that the proposed strategy can provide satisfactory tracking performance and disturbance rejection.

  2. Hydronic Heating Retrofits for Low-Rise Multifamily Buildings: Boiler Control Replacement and Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Dentz, J.; Henderson, H.; Varshney, K.

    2013-10-01

    The ARIES Collaborative, a U.S. Department of Energy Building America research team, partnered with NeighborWorks America affiliate Homeowners' Rehab Inc. of Cambridge, Massachusetts, to implement and study improvements to the central hydronic heating system in one of the nonprofit's housing developments. The heating control systems in the three-building, 42-unit Columbia Cambridge Alliance for Spanish Tenants housing development were upgraded.

  3. Improvement on control system of the JT-60 radio frequency heating system

    Energy Technology Data Exchange (ETDEWEB)

    Shinozaki, Shin-ichi; Moriyama, Shinichi; Hiranai, Shinichi [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Sato, Fumiaki [Nippon Advanced Technology Co., Ltd., Tokai, Ibaraki (Japan)

    2003-03-01

    On the JT-60 radio frequency (RF) heating system, the decrease in the activity ratio was a problem because of the deterioration of the control system. To improve the reliability, we replaced CAMAC system for a power injection control system, which was a main cause of the trouble, with the microprocessor system. And, a function of computer supported programming function of RF power injection form was introduced, which contributed to reduce a load of operators. Furthermore, personal computers with network communication were introduced to improve a maintenance ability of the control system. As a result, the activity ratio of the RF heating system was improved significantly. (author)

  4. Solar heating and cooling system installed at RKL Controls Company, Lumberton, New Jersey

    Science.gov (United States)

    1981-01-01

    The final results of the design and operation of a computer controlled solar heated and cooled 40,000 square foot manufacturing building, sales office, and computer control center/display room are summarized. The system description, test data, major problems and resolutions, performance, operation and maintenance manual, equipment manufacturers' literature, and as-built drawings are presented. The solar system is composed of 6,000 square feet of flat plate collectors, external above ground storage subsystem, controls, absorption chiller, heat recovery, and a cooling tower.

  5. Installation package for integrated programmable electronic controller and hydronic subsystem - solar heating and cooling

    Science.gov (United States)

    1978-01-01

    A description is given of the Installation, Operation, and Maintenance Manual and information on the power panel and programmable microprocessor, a hydronic solar pump system and a hydronic heating hot water pumping system. These systems are integrated into various configurations for usages in solar energy management, control and monitoring, lighting control, data logging and other solar related applications.

  6. Testing the control systems of district heating substations under operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Koskelainen, R.; Ohvanainen, M.

    1996-12-31

    This research project `Testing the control systems of district heating substations under operating conditions` has been carried out at the Laboratory of Energy Economics and Power Plant Engineering at Helsinki University of Technology. A well-operating control system improves comfort of living and quality of district heating. In addition it saves energy. Testing of the control systems is a part of appropriate quality control and inspection. The aim of this research has been to develop a testing method for control systems of district heating substations. Operation of the control equipment has been studied in order to define the demands of a measuring method and equipment. Measurements have been done mainly in residential buildings under operating conditions and by changing the set value of the domestic hot water temperature. Several control problems occurred with temperature: oscillation, floating, deviation from the set value and transient fluctuations. Most of the problems occurred in controlling the domestic water temperature. A testing method should be developed so that all control problems are taken into account. Special attention should be paid to measuring time, sampling time, measuring sensors and equipment. The results of this study show that two separate testing methods should be developed. One should test whether the control equipment operates well or not. The other test should analyze the operation of control equipment and also find out what causes the control problems

  7. Volumetric Differences in Cerebellar Lobes in Individuals from Multiplex Alcohol Dependence Families and Controls: Their Relationship to Externalizing and Internalizing Disorders and Working Memory.

    Science.gov (United States)

    Hill, Shirley Y; Lichenstein, Sarah D; Wang, Shuhui; O'Brien, Jessica

    2016-12-01

    Offspring from families with multiple cases of alcohol dependence have a greater likelihood of developing alcohol dependence and related substance use disorders. Greater susceptibility for these disorders may be related to cerebellar morphology. Because posterior regions of the cerebellum are associated with cognitive abilities, we investigated whether high-risk offspring would display regionally specific differences in cerebellar morphology and whether these would be related to working memory performance. The relationship to externalizing and internalizing psychopathology was of interest because cerebellar morphology has previously been associated with a cognitive affective syndrome. A total of 131 participants underwent magnetic resonance imaging (MRI) with volumes of the cerebellar lobes obtained with manual tracing. These individuals were from high-risk (HR) for alcohol dependence families (N = 72) or from low-risk (LR) control families (N = 59). All were enrolled in a longitudinal follow-up that included repeated clinical assessments during childhood and young-adulthood prior to the scan that provided information on Axis I psychopathology. The Working Memory Index of the Wechsler Memory Scale was given at the time of the scan. Larger volumes of the corpus medullare and inferior posterior lobes and poorer working memory performance were found for the HR offspring relative to LR controls. Across all subjects, a significant positive association between working memory and total volume of corpus of the cerebellum was seen, controlling for familial risk. Presence of an internalizing or externalizing disorder interacting with familial risk was also associated with volume of the corpus medullare.

  8. High Volumetric Energy Density Hybrid Supercapacitors Based on Reduced Graphene Oxide Scrolls.

    Science.gov (United States)

    Rani, Janardhanan R; Thangavel, Ranjith; Oh, Se-I; Woo, Jeong Min; Chandra Das, Nayan; Kim, So-Yeon; Lee, Yun-Sung; Jang, Jae-Hyung

    2017-07-12

    The low volumetric energy density of reduced graphene oxide (rGO)-based electrodes limits its application in commercial electrochemical energy storage devices that require high-performance energy storage capacities in small volumes. The volumetric energy density of rGO-based electrode materials is very low due to their low packing density. A supercapacitor with enhanced packing density and high volumetric energy density is fabricated using doped rGO scrolls (GFNSs) as the electrode material. The restacking of rGO sheets is successfully controlled through synthesizing the doped scroll structures while increasing the packing density. The fabricated cell exhibits an ultrahigh volumetric energy density of 49.66 Wh/L with excellent cycling stability (>10 000 cycles). This unique design strategy for the electrode material has significant potential for the future supercapacitors with high volumetric energy densities.

  9. Design Fluida Temperature Control in Heat Exchanger using Model Predictive Control Algoritm

    Directory of Open Access Journals (Sweden)

    Fatimah Ekasari Masturi

    2014-03-01

    Full Text Available Heat Exchanger merupakan suatu alat proses pertukaran panas, berfungsi untuk memindahkan panas antara dua fluida yang berbeda temperatur dan dipisahkan oleh suatu sekat pemisah. Pada proses perpindahan panas ini terdapat delay time sehingga dibutuhkan suatu kontroller agar diperoleh temperatur fluida sesuai dengan kriteria yang diinginkan, tidak terdapat energi yang terbuang, serta pemanfaatan sumber energi yang tersedia benar-benar dapat lebih efisien. Model Predictive Control (MPC telah berhasil diaplikasikan di berbagai industri proses, karena kemampuannya untuk mengatasi berbagai masalah multivariabel kontrol seperti interaksi, waktu tunda dan batasan. Keuntungan dari MPC karena kedua variabel, yaitu variabel manipulasi dan variabel kontrol, dihitung dengan menggunakan teknik optimasi. Pengendalian terhadap pendekatan linear plant dengan Kontroler MPC menggunakan parameter Hp (prediksi horizon= 20 Hc(kontrol horizon= 4 matriks pembobot Q=1 R=0.1  dapat menghasilkan respon yang stabil tanpa adanya overshoot serta mampu mencapai setpoint yang diinginkan yaitu 70°C, pada beban tetap (nominal ataupun beban bervariasi sekitar 20 % dari beban nominal dengan waktu steady state 35s.

  10. Nanoscale control of heat generation with plasmonic nanostructures

    OpenAIRE

    Morales Dalmau, Jordi

    2013-01-01

    [ANGLÈS] During the last 25 years nanotechnology has become a transvers field either in research and everyday's live. In this work we present a method which can control temperature down to nanoscale thanks to plasmonic properties of gold nanoparticles. Moreover, we open a new field named "thermal engineering" which has the aim of performing adaptable thermal maps for every purpose at nanoscale. [CASTELLÀ] Durante los últimos 25 años la nanotecnología se ha situado como un importante campo ...

  11. HEAT PUMP GAS COOLER CONTROL USING CRITERION OF MINIMUM OF EXERGY LOSSSES

    Directory of Open Access Journals (Sweden)

    Sit M.L.

    2014-08-01

    Full Text Available This paper focuses on the development of the criterion of optimality of transients of the control system, based on the minimum of exergy losses in the gas cooler of carbon dioxide heat pump. It is noted that the exergy quality criterion has a clear physical meaning, as compared with the integral quadratic criterion in which the choice of the coefficients in the integrand is not justified. Mathematic model of heat exchanger is obtained using the method of solving differential equations, without going to the irrational transfer functions. The model is reduced to transfer functions of the first and second order with the delay. The continuous temperature control system of heat pump gas cooler is considered. It is shown, that one of the versions of the control system for the minimization of the proposed criterion can be a combined control system using both the principle of the negative feedback and the principle of the invariance related to a number of disturbances affecting the processes of heat transfer in the heat exchanger.

  12. Divertor heat and particle control experiments on the DIII-D tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Mahdavi, M.A; Baker, D.R. [General Atomics, San Diego, CA (United States); Allen, S.L. [Lawrence Livermore National Lab., CA (United States)] [and others

    1994-05-01

    In this paper we present a summary of recent DIII-D divertor physics activity and plans for future divertor upgrades. During the past year, DIII-D experimental effort was focused on areas of active heat and particle control and divertor target erosion studies. Using the DIII-D Advanced Divertor system we have succeeded for the first time to control the plasma density and demonstrate helium exhaust in H-mode plasmas. Divertor heat flux control by means of D{sub 2} gas puffing and impurity injection were studied separately and in, both cases up to a factor of five reduction of the divertor peak heat flux was observed. Using the DiMES sample transfer system we have obtained erosion data on various material samples in well diagnosed plasmas and compared the results with predictions of numerical models.

  13. SU-E-T-426: Feasibility of Stereotactic Body Radiation Therapy (SBRT) Treatment of Pancreatic Cancer Using Volumetric Modulated Arc Therapy (VMAT) with Active Breathing Control (ABC)

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y; Jackson, J; Davies, G; Herman, J; Forbang, R Teboh [John Hopkins University, Baltimore, MD (United States)

    2015-06-15

    Purpose: SBRT shows excellent tumor control and toxicity rates for patients with locally advanced pancreatic cancer (PCA). Herein, we evaluate the feasibility of using VMAT with ABC for PCA SBRT. Methods: Nine PCA patients previously treated via SBRT utilizing 11-beam step-and-shoot IMRT technique in our center were retrospectively identified, among whom eight patients received 3300cGy in 5 fractions while one received 3000cGy in 5 fractions. A VMAT plan was generated on each patient’s planning CT in Pinnacle v9.8 on Elekta Synergy following the same PCA SBRT clinical protocol. Three partial arcs (182°–300°, 300°-60°, and 60°-180°) with 2°/4° control-point spacing were used. The dosimetric difference between the VMAT and the original IMRT plans was analyzed. IMRT QA was performed for the VMAT plans using MapCheck2 in MapPHAN and the total delivery time was recorded. To mimic the treatment situation with ABC, where patients hold their breath for 20–30 seconds, the delivery was intentionally interrupted every 20–30 seconds. For each plan, the QA was performed with and without beam interruption. Gamma analysis (2%/2mm) was used to compare the planned and measured doses. Results: All VMAT plans with 2mm dose grid passed the clinic protocol with similar PTV coverage and OARs sparing, where PTV V-RxDose was 92.7±2.1% (VMAT) vs. 92.1±2.6% (IMRT), and proximal stomach V15Gy was 3.60±2.69 cc (VMAT) vs. 4.80±3.13 cc (IMRT). The mean total MU and delivery time of the VMAT plans were 2453.8±531.1 MU and 282.1±56.0 seconds. The gamma passing rates of absolute dose were 94.9±3.4% and 94.5±4.0% for delivery without and with interruption respectively, suggesting the dosimetry of VMAT delivery with ABC for SBRT won’t be compromised. Conclusion: This study suggests that PCA SBRT using VMAT with ABC is a feasible technique without compromising plan dosimetry. The combination of VMAT with ABC will potentially reduce the SBRT treatment time.

  14. Online and Compositional Learning of Controllers with Application to Floor Heating

    DEFF Research Database (Denmark)

    Larsen, Kim Guldstrand; Mikučionis, Marius; Muniz, Marco

    2016-01-01

    Controller synthesis for stochastic hybrid switched systems, like e.g. a floor heating system in a house, is a complex computational task that cannot be solved by an exhaustive search though all the control options. The state-space to be explored is in general uncountable due to the presence of c...... of the whole state-space. For additional scalability we propose and apply a compositional synthesis approach. Finally, we demonstrate the applicability of the methodology to a concrete floor heating system of a real family house....

  15. Solar heating and cooling system installed at RKL Controls Company, Lumberton, New Jersey. Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-03-01

    Solar heating and cooling of a 40,000 square foot manufacturing building, sales offices and the solar computer control center/display room are described. Information on system description, test data, major problems and resolutions, performance, operation and maintenance manual, manufacturer's literature and as-built drawings are provided also. The solar system is composed of 6000 square feet of Sunworks double glazed flat plate collectors, external above ground storage subsystem, controls, ARKLA absorption chiller, heat recovery and a cooling tower.

  16. Research on temperature control with numerical regulators in electric resistance furnaces with indirect heating

    Science.gov (United States)

    Diniş, C. M.; Popa, G. N.; Iagăr, A.

    2016-02-01

    The paper is an analysis of two-positions (hysteresis) regulators, self-tuned PID controller and PID controller for temperature control used for indirect heat resistance furnaces. For PID controller was used three methods of tuning: Ziegler-Nichols step response model, Cohen-Coon tuning rules and Ziegler-Nichols tuning rules. In experiments it used an electric furnace with indirect heating with active power of resistance of 1 kW/230V AC and a numerical temperature regulator AT-503 type (ANLY). It got a much better temperature control when using the Cohen-Coon tuning rules method than those of Ziegler-Nichols step response method and Ziegler-Nichols tuning rules method.

  17. Intelligent Integration between Human Simulated Intelligence and Expert Control Technology for the Combustion Process of Gas Heating Furnace

    Directory of Open Access Journals (Sweden)

    Yucheng Liu

    2014-01-01

    Full Text Available Due to being poor in control quality of the combustion process of gas heating furnace, this paper explored a sort of strong robust control algorithm in order to improve the control quality of the combustion process of gas heating furnace. The paper analyzed the control puzzle in the complex combustion process of gas heating furnace, summarized the cybernetics characteristic of the complex combustion process, researched into control strategy of the uncertainty complex control process, discussed the control model of the complex process, presented a sort of intelligent integration between human-simulated intelligence and expert control technology, and constructed the control algorithm for the combustion process controlling of gas heating furnace. The simulation results showed that the control algorithm proposed in the paper is not only better in dynamic and steady quality of the combustion process, but also obvious in energy saving effect, feasible, and effective in control strategy.

  18. Control strategy on the double-diffusive convection in a nanofluid layer with internal heat generation

    Science.gov (United States)

    Mokhtar, N. F. M.; Khalid, I. K.; Siri, Z.; Ibrahim, Z. B.; Gani, S. S. A.

    2017-10-01

    The influences of feedback control and internal heat source on the onset of Rayleigh-Bénard convection in a horizontal nanofluid layer is studied analytically due to Soret and Dufour parameters. The confining boundaries of the nanofluid layer (bottom boundary-top boundary) are assumed to be free-free, rigid-free, and rigid-rigid, with a source of heat from below. Linear stability theory is applied, and the eigenvalue solution is obtained numerically using the Galerkin technique. Focusing on the stationary convection, it is shown that there is a positive thermal resistance in the presence of feedback control on the onset of double-diffusive convection, while there is a positive thermal efficiency in the existence of internal heat generation. The possibilities of suppress or augment of the Rayleigh-Bénard convection in a nanofluid layer are also discussed in detail.

  19. Cost-effective control systems for solar heating and cooling applications. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Pejsa, J. H.; Bassett, W. W.; Wenzler, S. A.; Nguyen, K. H.; Olson, T. J.

    1978-09-01

    A methodology has been defined to arrive at control recommendations for a variety of climate control system designs, applications and regions, and the results are presented in two parts. Part I consists of a literature and market-place survey, involving control strategies, functions, sensors, actuators, and the controllers themselves. Part II represents the bulk of the study effort - an attempt to simulate and evaluate system performance for several representative residential and commercial heating and cooling designs and thus to derive improved performance techniques within cost-effective control systems. (MHR)

  20. Design of fishtail divetor for heat load control during long-pulse operation on EAST tokamak

    Science.gov (United States)

    Zhang, Xiao Dong; Huang, Yi Yun; Yao, Da Mao; Xiao, Bin Jia; Wu, Jie Feng; Qian, Jin Ping; Zhuang, Hui Dong; Zhang, Yang; EAST Team

    2017-10-01

    A new divertor concept, FishTail Divertor (FTD), is proposed and designed on EAST tokamak. The basic idea is to design and install an active coil near the strike point under the low divertor target. Applying the AC-current in this coil, the strike point along the radial and poloidal direction can be moved like a swing of fishtail by the additional alternating magnetic field. As a result, the wetted area of the heat flux is spread out, and thereby the averaged heat load is reduced. The heat flux on the divertor target has been simulated by using ANSYS combined with EFIT. It shows that the heat load on the carbon surface of the divertor can be reduced by a factor of 2/3 by applying this fishtail swing. Based on the simulations and preliminary engineering design, it is found that FTD has following advantages compare with other divertor concepts, such as the Snowflake divertor, X-divertor, Super-X divertor, and X-point target divertor: (1) Uniform distribution of the heat flux on the divertor plate; (2) Reliable control of heat load on the divertor plate; (3) Little effect on the plasma shape and X-point location; (4) Feasibility from the engineering and technology point of view.

  1. The active disturbance rejection control approach to stabilisation of coupled heat and ODE system subject to boundary control matched disturbance

    Science.gov (United States)

    Guo, Bao-Zhu; Liu, Jun-Jun; AL-Fhaid, A. S.; Younas, Arshad Mahmood M.; Asiri, Asim

    2015-08-01

    We consider stabilisation for a linear ordinary differential equation system with input dynamics governed by a heat equation, subject to boundary control matched disturbance. The active disturbance rejection control approach is applied to estimate, in real time, the disturbance with both constant high gain and time-varying high gain. The disturbance is cancelled in the feedback loop. The closed-loop systems with constant high gain and time-varying high gain are shown, respectively, to be practically stable and asymptotically stable.

  2. Pulse Mask Controlled HFAC Resonant Converter for high efficiency Industrial Induction Heating with less harmonic distortion

    Directory of Open Access Journals (Sweden)

    Nagarajan Booma

    2016-04-01

    Full Text Available This paper discusses about the fixed frequency pulse mask control based high frequency AC conversion circuit for industrial induction heating applications. Conventionally, for induction heating load, the output power control is achieved using the pulse with modulation based converters. The conventional converters do not guarantee the zero voltage switching condition required for the minimization of the switching losses. In this paper, pulse mask control scheme for the power control of induction heating load is proposed. This power control strategy allows the inverter to operate closer to the resonant frequency, to obtain zero voltage switching condition. The proposed high frequency AC power conversion circuit has lesser total harmonic distortion in the supply side. Modeling of the IH load, design of conversion circuit and principle of the control scheme and its implementation using low cost PIC controller are briefly discussed. Simulation results obtained using the Matlab environment are presented to illustrate the effectiveness of the pulse mask scheme. The obtained results indicate the reduction in losses, improvement in the output power and lesser harmonic distortion in the supply side by the proposed converter. The hardware results are in good agreement with the simulation results.

  3. Nonlinear Adaptive Dynamic Output-Feedback Power-Level Control of Nuclear Heating Reactors

    Directory of Open Access Journals (Sweden)

    Zhe Dong

    2013-01-01

    Full Text Available Due to the high safety performance of small nuclear reactors, there is a promising future for small reactors. Nuclear heating reactor (NHR is a small reactor that has many advanced safety features such as the integrated arrangement, natural circulation at any power levels, self-pressurization, hydraulic control rod driving, and passive residual heating removing and can be applied to the fields of district heating, seawater desalination, and electricity production. Since the NHR dynamics has strong nonlinearity and uncertainty, it is meaningful to develop the nonlinear adaptive power-level control technique. From the idea of physically based control design method, a novel nonlinear adaptive power-level control is given for the NHR in this paper. It is theoretically proved that this newly built controller does not only provide globally asymptotic closed-loop stability but is also adaptive to the system uncertainty. Numerical simulation results show the feasibility of this controller and the relationship between the performance and controller parameters.

  4. Demonstration of leapfrogging for implementing nonlinear model predictive control on a heat exchanger.

    Science.gov (United States)

    Sridhar, Upasana Manimegalai; Govindarajan, Anand; Rhinehart, R Russell

    2016-01-01

    This work reveals the applicability of a relatively new optimization technique, Leapfrogging, for both nonlinear regression modeling and a methodology for nonlinear model-predictive control. Both are relatively simple, yet effective. The application on a nonlinear, pilot-scale, shell-and-tube heat exchanger reveals practicability of the techniques. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  5. Supervisory control of a heavy-duty diesel engine with an electrified waste heat recovery system

    NARCIS (Netherlands)

    Feru, E.; Murgovski, N.; Jager, B. de; Willems, F.P.T.

    2016-01-01

    This paper presents an integrated energy and emission management strategy, called Integrated Power- train Control(IPC), for an Euro-VI diesel engine with an electrified waste heat recovery system. This strategy optimizes the CO – NOx 2 trade-off by minimizing the operational costs associated with

  6. Electric space heating scheduling for real-time explicit power control in active distribution networks

    DEFF Research Database (Denmark)

    Costanzo, Giuseppe Tommaso; Bernstein, Andrey; Chamorro, Lorenzo Reyes

    2015-01-01

    This paper presents a systematic approach for abstracting the flexibility of a building space heating system and using it within a composable framework for real-time explicit power control of microgrids and, more in general, active distribution networks. In particular, the proposed approach is de...

  7. A predictive model for smart control of a domestic heat pump and thermal storage

    NARCIS (Netherlands)

    van Leeuwen, Richard Pieter; Gebhardt, I.; de Wit, J.B.; Smit, Gerardus Johannes Maria

    The purpose of this paper is to develop and validate a predictive model of a thermal storage which is charged by a heat pump and used for domestic hot water supply. The model is used for smart grid control purposes and requires measurement signals of flow and temperature at the inlet and outlet of

  8. Central Control of Heat Pump for Smart Grid Purposes Tested on Single Family Houses

    DEFF Research Database (Denmark)

    Pedersen, Tom S.; Andersen, Palle; Nielsen, Kirsten M.

    2013-01-01

    A challenge in Denmark in the near future is to balance the electrical grid due to a large increase in the renewable energy production mainly from wind turbines. In this work a central control system using heat pumps in single family houses to help balancing the grid is investigated. The central...

  9. Shape optimization and optimal control for transient heat conduction problems using an isogeometric approach

    NARCIS (Netherlands)

    Wang, Z.; Turteltaub, S.R.; Abdalla, M.M.

    2017-01-01

    This work is concerned with the development of a framework to solve shape optimization problems for transient heat conduction problems within the context of isogeometric analysis (IGA). A general objective functional is used to accommodate both shape optimization and passive control problems

  10. Influence of room heating on ambulatory blood pressure in winter: a randomised controlled study.

    Science.gov (United States)

    Saeki, Keigo; Obayashi, Kenji; Iwamoto, Junko; Tanaka, Yuu; Tanaka, Noriyuki; Takata, Shota; Kubo, Hiroko; Okamoto, Nozomi; Tomioka, Kimiko; Nezu, Satoko; Kurumatani, Norio

    2013-06-01

    Previous studies have proposed that higher blood pressure (BP) in winter is an important cause of increased mortality from cardiovascular disease during the winter. Some observational and physiological studies have shown that cold exposure increases BP, but evidence from a randomised controlled study assessing the effectiveness of intensive room heating for lowering BP was lacking. The present study aimed to determine whether intensive room heating in winter decreases ambulatory BP as compared with weak room heating resulting in a 10°C lower target room temperature when sufficient clothing and bedclothes are available. We conducted a parallel group, assessor blinded, simple randomised controlled study with 1:1 allocation among 146 healthy participants in Japan from November 2009 to March 2010. Ambulatory BP was measured while the participants stayed in single experimental rooms from 21:00 to 8:00. During the session, participants could adjust the amount of clothing and bedclothes as required. Compared with the weak room heating group (mean temperature ± SD: 13.9 ± 3.3°C), systolic morning BP (mean BP 2 h after getting out of bed) of the intensive room heating group (24.2 ± 1.7°C) was significantly lower by 5.8 mm Hg (95% CI 2.4 to 9.3). Sleep-trough morning BP surges (morning BP minus lowest night-time BP) in the intensive room heating group were significantly suppressed to about two thirds of the values in the weak room heating group (14.3 vs 21.9 mm Hg; pheating decreased morning BP and the morning BP surge in winter.

  11. A Review of Heating and Temperature Control in Microfluidic Systems: Techniques and Applications

    Directory of Open Access Journals (Sweden)

    Marie-Caroline Jullien

    2013-01-01

    Full Text Available This review presents an overview of the different techniques developed over the last decade to regulate the temperature within microfluidic systems. A variety of different approaches has been adopted, from external heating sources to Joule heating, microwaves or the use of lasers to cite just a few examples. The scope of the technical solutions developed to date is impressive and encompasses for instance temperature ramp rates ranging from 0.1 to 2,000 °C/s leading to homogeneous temperatures from −3 °C to 120 °C, and constant gradients from 6 to 40 °C/mm with a fair degree of accuracy. We also examine some recent strategies developed for applications such as digital microfluidics, where integration of a heating source to generate a temperature gradient offers control of a key parameter, without necessarily requiring great accuracy. Conversely, Temperature Gradient Focusing requires high accuracy in order to control both the concentration and separation of charged species. In addition, the Polymerase Chain Reaction requires both accuracy (homogeneous temperature and integration to carry out demanding heating cycles. The spectrum of applications requiring temperature regulation is growing rapidly with increasingly important implications for the physical, chemical and biotechnological sectors, depending on the relevant heating technique.

  12. A Review of Heating and Temperature Control in Microfluidic Systems: Techniques and Applications

    Science.gov (United States)

    Miralles, Vincent; Huerre, Axel; Malloggi, Florent; Jullien, Marie-Caroline

    2013-01-01

    This review presents an overview of the different techniques developed over the last decade to regulate the temperature within microfluidic systems. A variety of different approaches has been adopted, from external heating sources to Joule heating, microwaves or the use of lasers to cite just a few examples. The scope of the technical solutions developed to date is impressive and encompasses for instance temperature ramp rates ranging from 0.1 to 2,000 °C/s leading to homogeneous temperatures from −3 °C to 120 °C, and constant gradients from 6 to 40 °C/mm with a fair degree of accuracy. We also examine some recent strategies developed for applications such as digital microfluidics, where integration of a heating source to generate a temperature gradient offers control of a key parameter, without necessarily requiring great accuracy. Conversely, Temperature Gradient Focusing requires high accuracy in order to control both the concentration and separation of charged species. In addition, the Polymerase Chain Reaction requires both accuracy (homogeneous temperature) and integration to carry out demanding heating cycles. The spectrum of applications requiring temperature regulation is growing rapidly with increasingly important implications for the physical, chemical and biotechnological sectors, depending on the relevant heating technique. PMID:26835667

  13. CO2 as a heat pump working fluid for retrofitting hydronic heating systems in Western Europe

    Energy Technology Data Exchange (ETDEWEB)

    Enkemann, T.; Kruse, H. [FKW Research Center for Refrigeration and Heat Pumps, University of Hannover, Hannover (Germany); Oostendorp, P.A. [TNO Institute of Environmental Sciences, Energy Research and Process Innovation TNO-MEP, Apeldoorn (Netherlands)

    1998-12-31

    The use of heat pumps instead of conventional heating systems seems to be a promising way to reduce CO2 emissions contributing to the global warming impact in the field of space heating. Concerning the equipment of new buildings one can see a growing market for heat pumps in some cases due to governmental supporting measures. Since the number of existing buildings is much higher than the number of new buildings, the use of heat pumps should also be expanded to this market. Due to the design of the older systems with high supply temperatures of the hydronic heating system the application of existing heat pumps is limited. The transcritical process with CO2 seems to be promising for this application. Cycle calculations considering the typical design of existing heating systems were made to obtain information about the cycle characteristics and the energetic behavior of a CO2 heat pump in such a system. The calculations were done for an air to water heat pump since this type is better suited for all-purpose installation for retrofit. It was found that a control of the high side pressure of the heat pump cycle is recommended to achieve a high COP for all seasonary conditions of the heat sink and the heat source as well as for the behavior of the volumetric heating capacity. The use of an internal heat exchanger is however not recommended since the advantages concerning COP and the behavior of the volumetric heating capacity is negligible while it leads to significantly higher discharge temperatures. Seasonal performance factors (SPF) were estimated on the basis of cycle calculations. For a heating system with design supply and return temperatures of 70C and 50C a value of 2.8 was found. In order to optimize the heat pump performance, a modification of the usual design of the heating system is proposed. The temperature difference between supply and return should be enlarged by reducing the mass flow of the water in the existing hydronic system. Calculations show that

  14. Receding horizon H∞ guaranteed cost tracking control for microwave heating medium with temperature-dependent permittivity.

    Science.gov (United States)

    Zhong, Jiaqi; Liang, Shan; Xiong, Qingyu

    2018-01-10

    This paper considers the temperature spectrum tracking control of microwave heating model, in the presence of asymmetrical input saturation, nonhomogeneous Neumann boundary condition and temperature-dependent permittivity. The sufficient condition for the existence of receding horizon H∞ guaranteed cost control is proposed based on the derived finite-dimensional ordinary differential equation (ODE) error model. Furthermore, by on-line updating and solving linear matrix inequalities (LMIs) optimization problem, the constrained tracking controller can be obtained in the sense of minimizing H∞ norm and satisfying the quadratic cost performance. The proposed control strategy is implemented on a one-dimensional cavity heating model and its performance is evaluated through the simulation. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

  15. Energy Savings and Economics of Advanced Control Strategies for Packaged Heat Pumps

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Weimin; Huang, Yunzhi; Katipamula, Srinivas

    2012-10-31

    Pacific Northwest National Laboratory (PNNL), with funding from the U.S. Department of Energy’s (DOE’s) Building Technologies Program (BTP), evaluated a number of control strategies for packaged cooling equipment that can be implemented in an advanced controller, which can be retrofit into existing packaged heat pump units to improve their operational efficiency. This report documents the results of that analysis.

  16. AUTOMATIC CONTROL SYSTEM FOR THE HEAT PUMP EMBEDDED IN THE MILK PASTEURIZATION AND COOLING INSTALLATION, part II

    Directory of Open Access Journals (Sweden)

    Sit M.L.

    2013-04-01

    Full Text Available The goal of the present work is to elaborate the scheme of the disturbance compensation system, which is influencing the level of refrigerant consumption in evaporators and gas coolers of the heat pump embedded in the milk pasteurization and cooling installation, as well as, to design the automatic control system for the heat-exchanger with two output parameters – the water temperature at the outlet of the primary and secondary heat-carrying agent circuits by adjusting the consumption level in the secondary heat-carrying agent circuit and by adjusting the heat exchange surface area. System structures are based on principles of the coordinated control and the multidimensional systems control. The proposed structural scheme of the coordinated system for control of the consumption in evaporators, both water heating and cooling segments, is more accurate in transient processes than alternative systems of non-integrated control of the working agent consumption in each evaporator. The heat exchanger control system with two controls controlling segments (controlling the heat exchange surface area and controlling the consumption level in the secondary coolant circuit has proven to have good transient characteristics.

  17. Distributed Control of Heat Conduction in Thermal Inductive Materials with 2D Geometrical Isomorphism

    Directory of Open Access Journals (Sweden)

    Chia-Yu Chou

    2014-09-01

    Full Text Available In a previous study we provided analytical and experimental evidence that some materials are able to store entropy-flow, of which the heat-conduction behaves as standing waves in a bounded region small enough in practice. In this paper we continue to develop distributed control of heat conduction in these thermal-inductive materials. The control objective is to achieve subtle temperature distribution in space and simultaneously to suppress its transient overshoots in time. This technology concerns safe and accurate heating/cooling treatments in medical operations, polymer processing, and other prevailing modern day practices. Serving for distributed feedback, spatiotemporal H ∞ /μ control is developed by expansion of the conventional 1D-H ∞ /μ control to a 2D version. Therein 2D geometrical isomorphism is constructed with the Laplace-Galerkin transform, which extends the small-gain theorem into the mode-frequency domain, wherein 2D transfer-function controllers are synthesized with graphical methods. Finally, 2D digital-signal processing is programmed to implement 2D transfer-function controllers, possibly of spatial fraction-orders, into DSP-engine embedded microcontrollers.

  18. Optimisation of local heat networks by implementing modern control systems; Optimierung von Nahwaermenetzen mit moderner Regeltechnik

    Energy Technology Data Exchange (ETDEWEB)

    Siepmann, G. [Kieback und Peter GmbH und Co. KG, Berlin (Germany)

    2003-10-01

    In the community of Finnentrop, a local heat supply system balancing economic efficiency and environmental sustainability has been planned and implemented. The state-of-the-art control engineering connects and incorporates all installation components, ranging from heating through to substations optimizing all parts of the installation to ensure that only heat actually requested by the consumers is generated and transported. Flow temperature and revolutions of the pumps are controlled in accordance with the actual demand. The carrier of the installation itself performs the optimizations. The network data is also available to the malfunction management and accessible via interfaces for economical and statistical purposes. The installation in Finnentrop is a good example of how local heat networks and installations can be optimized by implementing modern control engineering. A further example is the technology 'Hast-Akku' which combines energy management and storage management intelligently. (orig.) [German] In Nahwaermeversorgungssystemen koennen durch den Einsatz moderner Regeltechnik erhebliche Energiesparpotenziale geschaffen werden. Gleichzeitig wird die Betriebssicherheit erhoeht, die Betriebsfuehrung optimiert und der Komfort fuer Waermekunden verbessert. Ein Beispiel dafuer ist das Nahwaerme-Projekt in der sauerlaendischen Gemeinde Finnentrop. (orig.)

  19. Magnetization transfer ratio in Alzheimer disease: comparison with volumetric measurements.

    Science.gov (United States)

    Ridha, B H; Symms, M R; Tozer, D J; Stockton, K C; Frost, C; Siddique, M M; Lewis, E B; MacManus, D G; Boulby, P A; Barker, G J; Rossor, M N; Fox, N C; Tofts, P S

    2007-05-01

    Alzheimer disease (AD) is accompanied by macroscopic atrophy on volumetric MR imaging. A few studies have also demonstrated reduction in magnetization transfer ratio (MTR), suggesting microstructural changes in remaining brain tissue. This study assessed the value of measuring MTR in addition to volumetric MR in differentiating patients with AD from control subjects. Volumetric T1-weighted images and 3D MTR maps were obtained from 18 patients with AD and 18 age-matched control subjects. Whole-brain (WB) and total hippocampal (Hc) volumes were measured using semiautomated techniques and adjusted for total intracranial volume. Mean MTR was obtained for WB and in the Hc region. Histogram analysis was performed for WB MTR. Among patients, associations between volumetric and MTR parameters and the Mini-Mental State Examination (MMSE) were explored. Patients with AD had significantly reduced WB volume (P<.0001) and mean WB MTR (P=.002) and Hc volume (P<.0001) and Hc mean MTR (P<.0001) compared with control subjects. Histogram analysis of WB MTR revealed significant reduction in the 25th percentile point in patients with AD (P=.03). Both WB volume and mean MTR were independently associated with case-control status after adjusting for the other using linear regression models. However, measuring Hc mean MTR added no statistically significant discriminatory value over and above Hc volume measurement alone. Of all MR imaging parameters, only WB volume was significantly correlated with MMSE (r=0.47, P=.048). This study demonstrates the independent reduction of WB volume and mean MTR in AD. This suggests that the 2 parameters reflect complementary aspects of the AD pathologic lesion at macrostructural and microstructural levels.

  20. Volumetric Properties of the Mixture Tribromomethane CHBr3 + C6H12 Cyclohexane (VMSD1211, LB4213_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Tribromomethane CHBr3 + C6H12 Cyclohexane (VMSD1211, LB4213_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  1. Volumetric Properties of the Mixture Cyclohexane C6H12 + C12H22 Bicyclohexyl (VMSD1211, LB3527_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C12H22 Bicyclohexyl (VMSD1211, LB3527_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  2. Volumetric Properties of the Mixture Tetrachloroethene C2Cl4 + C6H12 Cyclohexane (VMSD1211, LB4408_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Tetrachloroethene C2Cl4 + C6H12 Cyclohexane (VMSD1211, LB4408_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  3. Volumetric Properties of the Mixture Cyclohexene C6H10 + C6H12 Cyclohexane (VMSD1211, LB4459_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexene C6H10 + C6H12 Cyclohexane (VMSD1211, LB4459_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  4. Volumetric Properties of the Mixture Trichloroethene C2HCl3 + C6H12 Cyclohexane (VMSD1211, LB5131_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Trichloroethene C2HCl3 + C6H12 Cyclohexane (VMSD1211, LB5131_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  5. Optimal Design of a Thermoelectric Cooling/Heating System for Car Seat Climate Control (CSCC)

    Science.gov (United States)

    Elarusi, Abdulmunaem; Attar, Alaa; Lee, Hosung

    2017-04-01

    In the present work, the optimum design of thermoelectric car seat climate control (CSCC) is studied analytically in an attempt to achieve high system efficiency. Optimal design of a thermoelectric device (element length, cross-section area and number of thermocouples) is carried out using our newly developed optimization method based on the ideal thermoelectric equations and dimensional analysis to improve the performance of the thermoelectric device in terms of the heating/cooling power and the coefficient of performance (COP). Then, a new innovative system design is introduced which also includes the optimum input current for the initial (transient) startup warming and cooling before the car heating ventilation and air conditioner (HVAC) is active in the cabin. The air-to-air heat exchanger's configuration was taken into account to investigate the optimal design of the CSCC.

  6. Spacecraft Radiator Freeze Protection Using a Regenerative Heat Exchanger with Bypass Setpoint Temperature Control

    Science.gov (United States)

    Ungar, Eugene K.

    2008-01-01

    Spacecraft radiators are sized for their maximum heat load in their warmest thermal environment, but must operate at reduced heat loads and in colder environments. For systems where the radiator environment can be colder than the working fluid freezing temperature, radiator freezing becomes an issue. Radiator freezing has not been a major issue for the Space Shuttle and the International Space Station (ISS) active thermal control systems (ATCSs) because they operate in environments that are warm relative to the freezing point of their external coolants (Freon-21 and ammonia, respectively). For a vehicle that lands at the Lunar South Pole, the design thermal environment is 215K, but the radiator working fluid must also be kept from freezing during the 0 K sink of transit. A radiator bypass flow control design such as those used on the Space Shuttle and ISS requires more than 30% of the design heat load to avoid radiator freezing during transit - even with a very low freezing point working fluid. By changing the traditional ATCS architecture to include a regenerating heat exchanger inboard of the radiator and by using a regenerator bypass flow control valve to maintain system setpoint, the required minimum heat load can be reduced by more than half. This gives the spacecraft much more flexibility in design and operation. The present work describes the regenerator bypass ATCS setpoint control methodology. It includes analytical results comparing the performance of this system to the traditional radiator bypass system. Finally, a summary of the advantages of the regenerator bypass system are presented.

  7. Adaptive individual-cylinder thermal state control using intake air heating for a GDCI engine

    Energy Technology Data Exchange (ETDEWEB)

    Roth, Gregory T.; Sellnau, Mark C.

    2016-08-09

    A system for a multi-cylinder compression ignition engine includes a plurality of heaters, at least one heater per cylinder, with each heater configured to heat air introduced into a cylinder. Independent control of the heaters is provided on a cylinder-by-cylinder basis. A combustion parameter is determined for combustion in each cylinder of the engine, and control of the heater for that cylinder is based on the value of the combustion parameter for combustion in that cylinder. A method for influencing combustion in a multi-cylinder compression ignition engine, including determining a combustion parameter for combustion taking place in a cylinder of the engine and controlling a heater configured to heat air introduced into that cylinder, is also provided.

  8. An Optimal Control Approach for an Overall Cryogenic Plant Under Pulsed Heat Loads

    CERN Document Server

    Gómez Palacin, Luis; Blanco Viñuela, Enrique; Maekawa, Ryuji; Chalifour, Michel

    2015-01-01

    This work deals with the optimal management of a cryogenic plant composed by parallel refrigeration plants, which provide supercritical helium to pulsed heat loads. First, a data reconciliation approach is proposed to estimate precisely the refrigerator variables necessary to deduce the efficiency of each refrigerator. Second, taking into account these efficiencies, an optimal operation of the system is proposed and studied. Finally, while minimizing the power consumption of the refrigerators, the control system maintains stable operation of the cryoplant under pulsed heat loads. The management of the refrigerators is carried out by an upper control layer, which balances the relative production of cooling power in each refrigerator. In addition, this upper control layer deals with the mitigation of malfunctions and faults in the system. The proposed approach has been validated using a dynamic model of the cryoplant developed with EcosimPro software, based on first principles (mass and energy balances) and the...

  9. Translational control of small heat shock genes in mesophilic and thermophilic cyanobacteria by RNA thermometers.

    Science.gov (United States)

    Cimdins, Annika; Klinkert, Birgit; Aschke-Sonnenborn, Ursula; Kaiser, Friederike M; Kortmann, Jens; Narberhaus, Franz

    2014-01-01

    Cyanobacteria constitute a heterogeneous phylum of oxygen-producing, photosynthetic prokaryotes. They are susceptible to various stress conditions like heat, salt, or light stress, all inducing the cyanobacterial heat shock response (HSR). Cyanobacterial small heat shock proteins (sHsps) are known to preserve thylakoid membrane integrity under stress conditions, thereby protecting the photosynthesis machinery. In Synechocystis sp PCC 6803, synthesis of the sHsp Hsp17 is regulated by an RNA thermometer (RNAT) in the 5'-untranslated region (5'-UTR) of the hsp17 mRNA. RNATs are direct temperature sensors that control expression of many bacterial heat shock and virulence genes. They hinder translation at low temperatures by base pairing, thus blocking ribosome access to the mRNA.   To explore the temperature range in which RNATs act, we studied various RNAT candidates upstream of sHsp genes from mesophilic and thermophilic cyanobacteria. The mesophilic cyanobacteria Anabaena variabilis and Nostoc sp chromosomally encode two sHsps each. Reporter gene studies suggested RNAT-mediated post-transcriptional regulation of shsp expression in both organisms. Detailed structural analysis of the two A. variabilis candidates revealed two novel RNAT types. The first, avashort, regulates translation primarily by masking of the AUG translational start codon. The second, featuring an extended initial hairpin, thus named avalong, presumably makes use of complex tertiary interaction. The 5'-UTR of the small heat shock gene hspA in the thermophile Thermosynechococcus elongatus is predicted to adopt an extended secondary structure. Structure probing revealed that the ribosome binding site was blocked at temperatures below 55 °C. The results of this study demonstrate that cyanobacteria commonly use RNATs to control expression of their small heat shock genes.

  10. Control of wave-driven turbulence and surface heating on the mixing of microplastic marine debris

    Science.gov (United States)

    Kukulka, T.; Lavender Law, K. L.; Proskurowski, G. K.

    2016-02-01

    Buoyant microplastic marine debris (MPMD) is a pollutant in the ocean surface boundary layer (OSBL) that is submerged by turbulent transport processes. Langmuir circulation (LC) is a turbulent process driven by wind and surface waves that enhances mixing in the OSBL. Sea surface cooling also contributes to OSBL turbulence by driving convection. On the other hand, sea surface heating stratifies and stabilizes the water column to reduce turbulent motion. We analyze observed MPMD surface concentrations in the Atlantic and Pacific Oceans to reveal a significant increase in MPMD concentrations during surface heating and a decrease during surface cooling. Turbulence resolving large eddy simulations of the OSBL for an idealized diurnal heating cycle suggest that turbulent downward fluxes of buoyant tracers are enhanced at night, facilitating deep submergence of plastics, and suppressed in heating conditions, resulting in surface trapped MPMD. Simulations agree with observations if enhanced mixing due to LC is included. Our results demonstrate the controlling influence of surface heat fluxes and LC on turbulent transport in the OSBL and on vertical distributions of buoyant marine particles.

  11. Precision of laboratory methods based on protein solubility in quality control of heat treated feedstuffs

    Directory of Open Access Journals (Sweden)

    Palić Dragan V.

    2012-01-01

    Full Text Available Some of feedstuffs used as raw materials in feed industry contain anti-nutritional factors that negatively influence their quality. One of them is soybean, which is, prior to oil extraction, referred to as full-fat soybean (FFSB. Anti-nutritional factors in raw FFSB can be destroyed by moderate heating, but both over- and under heat processing limits the availability of soybean amino acids. Among laboratory procedures that are available for assessing the degree of FFSB heat treatment, two methods, i.e. Protein dispersibility index (PDI and protein solubility in potassium hydroxide (PSKOH, are based on protein solubility, which was claimed to be the most reliable indicator of the degree of FFSB heat treatment. This paper presents the results of an inter-laboratory study conducted to establish precision of the PDI and PSKOH methods by determining their reproducibility limits. Five samples of FFSB were heat-treated at temperatures between 110 and 164 °C and analyzed by six laboratories for PDI and PSKOH. Established reproducibility limit for PDI method of 8.87 index units found in this study appeared to be too wide, indicating a low precision of this method. PSKOH method produced very good reproducibility limit of 8.56% and could be recommended as a preferred method for FFSB quality control in feed laboratories.

  12. Geochemical implications of production and storage control by coupling a direct-use geothermal system with heat networks

    NARCIS (Netherlands)

    Daniilidis, Alexandros; Scholten, Tjardo; Hooghiem, Joram; Persis, Claudio De; Herber, Rien

    2017-01-01

    This paper outlines a method in which the heat production of a geothermal system is controlled in relation to the demand from a district-heating network. A model predictive control strategy is designed, which uses volume measurements in the storage tank, and predictions of the demand, to regulate

  13. Utility-controlled customer-side thermal-energy-storage tests: heat storage

    Energy Technology Data Exchange (ETDEWEB)

    Rizy, D.T.

    1982-02-01

    Customer-side thermal energy storage has been identified as a load-management option available to the electric utility industry. The tests described here are part of the US DOE national program for the research, development, and demonstration of electric load management using utility-controlled customer-side thermal energy storage for residential load management. Five heat storage tests are described in order to: collect reliable load-research data; delineate and solve installation problems; establish maintainability; determine customer and utility acceptance; and generate cost data to determine the potential of utility-controlled customer-side storage as a load-management option. The results are expected to assist the utility industry in making local load-management decisions and to assist DOE in establishing research and development priorities in load management. The utilities tested four types of heat storage systems: central ceramic brick; concrete slab; heat pump with storage; and pressurized hot water storage. Results of installing and operating the storage systems indicate that these residential heat storage systems are not fully commercial in their present state for use as a load-management option and the technology requires further development. Also, the numerous operational problems experienced by the utilities and high costs of installing and maintaining the storage equipment resulted in poor acceptance of the technology by the utilities and customers.

  14. Fractional-Order Identification and Control of Heating Processes with Non-Continuous Materials

    Directory of Open Access Journals (Sweden)

    Riccardo Caponetto

    2016-11-01

    Full Text Available The paper presents a fractional order model of a heating process and a comparison of fractional and standard PI controllers in its closed loop system. Preliminarily, an enhanced fractional order model for the heating process on non-continuous materials has been identified through a fitting algorithm on experimental data. Experimentation has been carried out on a finite length beam filled with three non-continuous materials (air, styrofoam, metal buckshots in order to identify a model in the frequency domain and to obtain a relationship between the fractional order of the heating process and the different materials’ properties. A comparison between the experimental model and the theoretical one has been performed, proving a significant enhancement of the fitting performances. Moreover the obtained modelling results confirm the fractional nature of the heating processes when diffusion occurs in non-continuous composite materials, and they show how the model’s fractional order can be used as a characteristic parameter for non-continuous materials with different composition and structure. Finally, three different kinds of controllers have been applied and compared in order to keep constant the beam temperature constant at a fixed length.

  15. Heat Transfer Fluid Temperature Control in a Thermoelectric Solar Power Plant

    Directory of Open Access Journals (Sweden)

    Lourdes A. Barcia

    2017-07-01

    Full Text Available Thermoelectric solar plants transform solar energy into electricity. Unlike photovoltaic plants, the sun’s energy heats a fluid (heat transfer fluid (HTF and this, in turn, exchanges its energy, generating steam. Finally, the steam generates electricity in a Rankine cycle. One of the main advantages of this double conversion (sun energy to heat in the HTF-Rankine cycle is the fact that it facilitates energy storage without using batteries. It is possible to store the heat energy in melted salts in such a way that this energy will be recovered when necessary, i.e., during the night. These molten salts are stored in containers in a liquid state at high temperature. The HTF comes into the solar field at a given temperature and increases its energy thanks to the solar collectors. In order to optimize the sun to HTF energy transference, it is necessary to keep an adequate temperature control of the fluid at the output of the solar fields. This paper describes three different algorithms to control the HTF output temperature.

  16. Pressure Pump Power Control in the Primary Circuit of the Heat Exchange System

    Directory of Open Access Journals (Sweden)

    Shilin Aleksandr

    2017-01-01

    Full Text Available In this paper we consider the problem of speed in hot water systems where highly efficient plate heat exchanger is used. Especially marked the problem which is connected with long transition drive of constant speed exceeding the time of the heat exchanger accumulative tank emptying more than twice. As a regulating element in the heat exchange system there was proposed to use asynchronous electric drive of pressure pump in the primary circuit of the heat exchanger. For correct use of such electric drive we solved the problem of control object mathematical model synthesis, which has non-linear properties, in particular, the transfer coefficient of the circuit can vary in more than 6 times. At the same time there was revealed the dependence of the transfer coefficient on the motor speed, which must be considered in the controller synthesis. In conclusion we suggested the solutions of regulators synthesis tasks with customizable settings for speed and switchable structure between relay λ and PI regulators.

  17. Using heat to control the sample spinning speed in MAS NMR.

    Science.gov (United States)

    Mihaliuk, Eugene; Gullion, Terry

    2011-10-01

    A new approach using temperature to control the spinning speed of a sample rotor in magic-angle spinning NMR is presented. Instead of an electro-mechanical valve that regulates the flow of drive gas to control the spinning speed in traditional MAS NMR systems, we use a small heater wire located directly in the stator. The sample spinning speed is controlled very accurately with a surprisingly low heating power of 1 W. Results on a benchtop unit demonstrate the capability of the system. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. High-volumetric performance aligned nano-porous microwave exfoliated graphite oxide-based electrochemical capacitors.

    Science.gov (United States)

    Ghaffari, Mehdi; Zhou, Yue; Xu, Haiping; Lin, Minren; Kim, Tae Young; Ruoff, Rodney S; Zhang, Q M

    2013-09-20

    Ultra-high volumetric performance electrochemical double layer capacitors based on high density aligned nano-porous microwave exfoliated graphite oxide have been studied. Elimination of macro-, meso-, and larger micro-pores from electrodes and controlling the nano-morphology results in very high volumetric capacitance, energy, and power density values. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Instrument-free exothermic heating with phase change temperature control for paper microfluidic devices

    Science.gov (United States)

    Singleton, Jered; Zentner, Chris; Buser, Josh; Yager, Paul; LaBarre, Paul; Weigl, Bernhard H.

    2013-03-01

    Many infectious diseases, as well as some cancers, that affect global health are most accurately diagnosed through nucleic acid amplification and detection. There is a great need to simplify nucleic acid-based assay systems for use in global health in low-resource settings as well as in settings that do not have convenient access to laboratory staff and equipment such as doctors' offices and home care settings. In developing countries, unreliable electric power, inadequate supply chains, and lack of maintenance for complex diagnostic instruments are all common infrastructure shortfalls. Many elements of instrument-free, disposable, nucleic acid amplification assays have been demonstrated in recent years. However, the problem of instrument-free,1 low-cost, temperature-controlled chemical heating remains unsolved. In this paper we present the current status and results of work towards developing disposable, low-cost, temperature-controlled heaters designed to support isothermal nucleic acid amplification assays that are integrated with a two-dimensional paper network. Our approach utilizes the heat generated through exothermic chemical reactions and controls the heat through use of engineered phase change materials to enable sustained temperatures required for nucleic acid amplification. By selecting appropriate exothermic and phase change materials, temperatures can be controlled over a wide range, suitable for various isothermal amplification methods, and maintained for over an hour at an accuracy of +/- 1°C.

  20. Nonlinear Lyapunov-based boundary control of distributed heat transfer mechanisms in membrane distillation plant

    KAUST Repository

    Eleiwi, Fadi

    2015-07-01

    This paper presents a nonlinear Lyapunov-based boundary control for the temperature difference of a membrane distillation boundary layers. The heat transfer mechanisms inside the process are modeled with a 2D advection-diffusion equation. The model is semi-descretized in space, and a nonlinear state-space representation is provided. The control is designed to force the temperature difference along the membrane sides to track a desired reference asymptotically, and hence a desired flux would be generated. Certain constraints are put on the control law inputs to be within an economic range of energy supplies. The effect of the controller gain is discussed. Simulations with real process parameters for the model, and the controller are provided. © 2015 American Automatic Control Council.

  1. Modelling, simulation and geometric optimization of cross flow recuperative heat exchanger based on controllability condition number

    Directory of Open Access Journals (Sweden)

    Stević Dalibor

    2017-01-01

    Full Text Available This paper presents the algebraic mathematical model of cross - flow heat exchanger derived on the basis of transport approach. Theirs operation in the face of variable loads is usually controlled by manipulating inlet fluid temperatures or mass flow rates, where the controlled variable is usually the output temperature of principal flow. The aim of this paper is to optimize the geometry of a tube with the inlet flow of principal incompressible fluid and an external cross - country flow of compressible fluid, based on performance index expressed throughout its controllability characteristics. Thus the condition number has been used to provide the necessary information on the best situation for control of the exchanger under consideration. This concept can also provide us with information about the easiest operating condition to control a particular output. A transient model of a cross-flow heat exchanger is developed, where an implicit formulation is used for transient numerical solutions. The condition number performed throughout the ratio of geometric parameters of tube is optimized, subject to volume constraints, based on the optimum operation in terms of output controllability. The reported optimized aspect ratio, water mass flow rate and output controllability are studied for different external properties of the tube.

  2. OPTIMAL CONTROL OF A NONLINEAR COUPLED ELECTROMAGNETIC INDUCTION HEATING SYSTEM WITH POINTWISE STATE CONSTRAINTS

    Directory of Open Access Journals (Sweden)

    Irwin Yousept

    2010-07-01

    Full Text Available An optimal control problem arising in the context of 3D electromagnetic induction heating is investigated. The state equation is given by a quasilinear stationary heat equation coupled with a semilinear time harmonic eddy current equation. The temperature-dependent electrical conductivity and the presence of pointwise inequality state-constraints represent the main challenge of the paper. In the first part of the paper, the existence and regularity of the state are addressed. The second part of the paper deals with the analysis of the corresponding linearized equation. Some suffcient conditions are presented which guarantee thesolvability of the linearized system. The final part of the paper is concerned with the optimal control. The aim of the optimization is to find the optimal voltage such that a desired temperature can be achieved optimally. The corresponding first-order necessary optimality condition is presented.

  3. The study of thermal processes in control systems of heat consumption of buildings

    Science.gov (United States)

    Tsynaeva, E.; A, Tsynaeva

    2017-11-01

    The article discusses the main thermal processes in the automated control systems for heat consumption (ACSHC) of buildings, schematic diagrams of these systems, mathematical models used for description of thermal processes in ACSHC. Conducted verification represented by mathematical models. It was found that the efficiency of the operation of ACSHC depend from the external and internal factors. Numerical study of dynamic modes of operation of ACSHC.

  4. Heat and Mass Transfer Remote Control in Bioreactors of Technological Lines

    Directory of Open Access Journals (Sweden)

    Viktorija M. Mel’nick

    2017-10-01

    Full Text Available Background. The main problems that arise when using equipment for cultivation are to ensure the heat and mass transfer processes in devices, presence of turbulent and stagnant zones, high-energy consumption, low heat transfer coefficients when working with viscous fluids. Objective. The aim of the paper is the experimental determination of the remote control heat transfer advantages in production line bioreactors using ultrasonic beam compared to contact methods. Methods. An experimental study of the heat and mass transfer process in a bioreactor on the stand with UZP-6-1 immersion unit of the ultrasonic radiator with radiation frequency 42 kHz is carried out. Results. Sound waves emitted into a liquid form a concentration zone of passable sound energy in the confocal vessel form of a cylindrical surface and force the liquid to move along the inner surface of the glass along the ascending cylindrical spiral, forming a motive flow throughout the volume, causing peripheral layers of liquid and bottom layers to move in a horizontal and vertical planes, without leaving stagnant zones. The closer to the coincidence angle is the directed ultrasonic beam the greater is the effectiveness of the driving flow. Conclusions. The use of sound waves allows obtaining a high-quality product in technological lines based on bioreactors with minimal risk for the technological process. Radiation parameters and working volume physic-mechanical properties change allow fully using the properties of resonant manifestations of the sound wave influence on the working liquid with minimal costs.

  5. Output feedback control of heat transport mechanisms in parabolic distributed solar collectors

    KAUST Repository

    Elmetennani, Shahrazed

    2016-08-05

    This paper presents an output feedback control for distributed parabolic solar collectors. The controller aims at forcing the outlet temperature to track a desired reference in order to manage the produced heat despite the external disturbances. The proposed control strategy is derived using the distributed physical model of the system to avoid the loss of information due to model approximation schemes. The system dynamics are driven to follow reference dynamics defined by a transport equation with a constant velocity, which allows to control the transient behavior and the response time of the closed loop. The designed controller depends only on the accessible measured variables which makes it easy for real time implementation and useful for industrial plants. Simulation results show the efficiency of the reference tracking closed loop under different working conditions.

  6. Development of a control logic for nuclear heating operation for primary system for SMART

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Jae Kwang; Kang, H. O.; Yoon, J. H.; Kim, K. K.; Lee, D. J

    2000-11-01

    A nuclear heating concept is adopted in the SMART compared with the commercial nuclear power plant using the primary coolant pumps for heating the primary system. In this report, five options of heatup control logic are proposed and each option is evaluated using MMS code. In option 1, control rod is controlled by a signal of difference in require heatup rate (dT/dt)req. and actual heatup rate (dT/dt)act., which is calculated from the measured value of core outlet temperature. In option 2, control rod is controlled by a signal of difference in reference temperature and actual measured temperature. In option 3, control rod is controlled by a signal of difference in required core power Qcore and actual measured core power N. Primary side temperature difference in measured values between steam generator (SG) inlet and outlet is used in determining Qcore in option 3. Because of this dependency on difference in measured temperature Qcore, in conjunction with measurement channel error in temperature, involves certain uncertainty during specially low flow conditions where primary side temperature difference in SG inlet and outlet is very small. Option 4 is a modified version of option 3. In option 4, SG outlet temperature is not needed to calculate Qcore. However a compensating program which enable Qcore to be evaluated without SG outlet temperature is needed. In option 5, control rod is controlled by a signal of difference in required preset step core power Qcore and actual measured core power N. From the simulation results it is concluded that option 5 using step power setting during heatup operation is suitable for as a heatup control logic for SMART.

  7. Dynamic Modeling and Control of Distributed Heat Transfer Mechanisms: Application to a Membrane Distillation Module

    KAUST Repository

    Eleiwi, Fadi

    2015-12-01

    Sustainable desalination technologies are the smart solution for producing fresh water and preserve the environment and energy by using sustainable renewable energy sources. Membrane distillation (MD) is an emerging technology which can be driven by renewable energy. It is an innovative method for desalinating seawater and brackish water with high quality production, and the gratitude is to its interesting potentials. MD includes a transfer of water vapor from a feed solution to a permeate solution through a micro-porous hydrophobic membrane, rejecting other non-volatile constituents present in the influent water. The process is driven by the temperature difference along the membrane boundaries. Different control applications and supervision techniques would improve the performance and the efficiency of the MD process, however controlling the MD process requires comprehensive mathematical model for the distributed heat transfer mechanisms inside the process. Our objective is to propose a dynamic mathematical model that accounts for the time evolution of the involved heat transfer mechanisms in the process, and to be capable of hosting intermittent energy supplies, besides managing the production rate of the process, and optimizing its energy consumption. Therefore, we propose the 2D Advection-Diffusion Equation model to account for the heat diffusion and the heat convection mechanisms inside the process. Furthermore, experimental validations have proved high agreement between model simulations and experiments with less than 5% relative error. Enhancing the MD production is an anticipated goal, therefore, two main control strategies are proposed. Consequently, we propose a nonlinear controller for a semi-discretized version of the dynamic model to achieve an asymptotic tracking for a desired temperature difference. Similarly, an observer-based feedback control is used to track sufficient temperature difference for better productivity. The second control strategy

  8. Computational prediction and control of energy consumption for heating in building structures

    Science.gov (United States)

    Jarošová, Petra; Vala, Jiří

    2017-07-01

    The significance of reasonable prediction and control of energy consumption in building structures follows from the natural requirements of the development of new materials, structures and technologies, as well as from the formal ones from European directives. This paper presents the method based on the generalized multiplicative Fourier decomposition, applied to a model of a building as certain thermal system. The design of the computational algorithm highlights the important contribution of solar radiation, as well as the design and control of the heating equipments. One illustrative numerical example shows the results of the practical implementation of this algorithm in the MATLAB environment.

  9. Non-Linear Advanced Control of the LHC Inner Triplet Heat Exchanger Test Unit

    CERN Document Server

    Blanco-Viñuela, E; De Prada-Moraga, C; Cristea, S

    2002-01-01

    The future Large Hadron Collider (LHC) at CERN will include eight interaction region final focus magnet systems, the so-called "Inner Triplet", one on each side of the four beam collision points. The Inner Triplets will be cooled in a static bath of pressurized He II nominally at 1.9 K. This temperature is a control parameter and has very severe constraints in order to avoid the transition from the superconducting to normal resistive state. The main difference in these special zones with respect to a regular LHC cell is higher dynamic heat load unevenly distributed which modifies largely the process characteristics and hence the controller performance. Several control strategies have already been tested at CERN in a pilot plant (LHC String Test) which reproduced a LHC half-cell. In order to validate a common control structure along the whole LHC ring, a Nonlinear Model Predictive Control (NMPC) has been developed and implemented in the Inner Triplet Heat Exchanger Unit (IT-HXTU) at CERN. Automation of the Inn...

  10. Experimental and numerical evaluations on palm microwave heating for Red Palm Weevil pest control

    Science.gov (United States)

    Massa, Rita; Panariello, Gaetano; Pinchera, Daniele; Schettino, Fulvio; Caprio, Emilio; Griffo, Raffaele; Migliore, Marco Donald

    2017-03-01

    The invasive Red Palm Weevil is the major pest of palms. Several control methods have been applied, however concern is raised regarding the treatments that can cause significant environmental pollution. In this context the use of microwaves is particularly attractive. Microwave heating applications are increasingly proposed in the management of a wide range of agricultural and wood pests, exploiting the thermal death induced in the insects that have a thermal tolerance lower than that of the host matrices. This paper describes research aiming to combat the Red Palm pest using microwave heating systems. An electromagnetic-thermal model was developed to better control the temperature profile inside the palm tissues. In this process both electromagnetic and thermal parameters are involved, the latter being particularly critical depending on plant physiology. Their evaluation was carried out by fitting experimental data and the thermal model with few free parameters. The results obtained by the simplified model well match with both that of a commercial software 3D model and measurements on treated Phoenix canariensis palms with a ring microwave applicator. This work confirms that microwave heating is a promising, eco-compatible solution to fight the spread of weevil.

  11. 3D dynamic simulation of heat transfer and melt flow in an inductively heated crystallization furnace for mc-silicon with PID temperature control

    Science.gov (United States)

    Bellmann, M. P.; Lindholm, D.; Sørheim, E. A.; Mortensen, D.; M'Hamdi, M.

    2013-11-01

    A heat transfer model of a semi-industrial induction furnace has been build, using a 3D finite element model in order to analyze the entire process cycle, based on the heating, melting, solidification and cooling phases of a multi-crystalline square ingot. In the modeling of the entire process, heat transfer phenomena such as radiation and conduction in the furnace have been taken into account. A PID (Proportional Integral Differential) control algorithm has been implemented into the model for adjusting the power input in the heaters, so that the heater temperature is kept at prescribed time-varying values. The furnace model and the PID control algorithm are validated by temperature measurements from a crystallization experiment. Subsequently the validated model was used to investigate the melt flow field and its impact on the solid-liquid interface shape.

  12. The relative importance of water vapour and dust in controlling the variability in radiative heating of the summertime Saharan heat low

    Science.gov (United States)

    Marsham, John H.; Parker, Douglas J.; Todd, Martin C.; Banks, Jamie R.; Brindley, Helen E.; Garcia-Carreras, Luis; Roberts, Alexander J.; Ryder, Claire L.

    2017-04-01

    The summertime Sahara heat low (SHL) is a key component of the West African monsoon (WAM) system but is a key source of uncertainty in global models. There is considerable uncertainty over the relative importance of water vapour and dust concentrations in controlling the radiation budget over the Sahara. This limits our ability to explain the variability and trends in the SHL and WAM systems, and so hampers our ability to reduce model biases. Here we use in situ observations from Fennec supersite-1 in the central Sahara from June 2011 and 2012, as well as satellite retrievals from GERB, to quantify how total column water vapour (TCWV) and dust aerosols control day-to-day variability in the energy balance in observations and ECMWF reanalyses (ERA-I). Results show that the earth-atmosphere system is radiatively heated in June 2011 and 2012. While we are not able to completely disentangle the roles of water vapour, clouds and dust from the observations, the analysis demonstrates that TCWV provides a far stronger control on TOA net radiation, and so the net heating of the earth-atmosphere system, than AOD does. Variations in dust provide a much stronger control on surface heating, but the reduction in surface heating associated with high dust loadings are largely compensated by associated increases in atmospheric heating, and so dust control on net TOA radiation is weak. Dust and TCWV are both important for direct atmospheric heating. ERA-I assimilated radiosondes from the Fennec campaign but uses a monthly dust climatology, and so cannot capture the impact of daily variations in dustiness. Despite this, ERA-I managed to capture the control of TOA net flux by TCWV, with a positive correlation (r = 0.6) between observed and modelled TOA net radiation. Variations in surface net radiation, and so the vertical profile of radiative heating, are not captured in ERA-I, given it does not capture variations in dust. Results show that ventilation of the SHL by cool moist air

  13. Heat Pump Water Heaters: Controlled Field Research of Impact on Space Conditioning and Demand Response Characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Parker, Graham B.; Widder, Sarah H.; Eklund, Ken; Petersen, Joseph M.; Sullivan, Greg

    2015-10-05

    A new generation of heat pump water heaters (HPWH) has been introduced into the U.S. market that promises to provide significant energy savings for water heating. Many electric utilities are promoting their widespread adoption as a key technology for meeting energy conservation goals and reducing greenhouse gas emissions. There is, however, considerable uncertainty regarding the space conditioning impact of an HPWH installed in a conditioned space. There is also uncertainty regarding the potential for deployment of HPWHs in demand response (DR) programs to help manage and balance peak utility loads in a similar manner as conventional electric resistance water heaters (ERWH). To help answer these uncertainties, controlled experiments have been undertaken over 30 months in a matched pair of unoccupied Lab Homes located on the campus of the Pacific Northwest National Laboratory (PNNL) in Richland, Washington.

  14. Transcriptional profile of breast muscle in heat stressed layers is similar to that of broiler chickens at control temperature.

    Science.gov (United States)

    Zahoor, Imran; de Koning, Dirk-Jan; Hocking, Paul M

    2017-09-20

    In recent years, the commercial importance of changes in muscle function of broiler chickens and of the corresponding effects on meat quality has increased. Furthermore, broilers are more sensitive to heat stress during transport and at high ambient temperatures than smaller egg-laying chickens. We hypothesised that heat stress would amplify muscle damage and expression of genes that are involved in such changes and, thus, lead to the identification of pathways and networks associated with broiler muscle and meat quality traits. Broiler and layer chickens were exposed to control or high ambient temperatures to characterise differences in gene expression between the two genotypes and the two environments. Whole-genome expression studies in breast muscles of broiler and layer chickens were conducted before and after heat stress; 2213 differentially-expressed genes were detected based on a significant (P broilers compared with control and heat-stressed layers. Expression of these genes was further increased in heat-stressed broilers. Differences in gene expression between broiler and layer chickens under control and heat stress conditions suggest that damage of breast muscles in broilers at normal ambient temperatures is similar to that in heat-stressed layers and is amplified when broilers are exposed to heat stress. The patterns of gene expression of the two genotypes under heat stress were almost the polar opposite of each other, which is consistent with the conclusion that broiler chickens were not able to cope with heat stress by dissipating their body heat. The differentially expressed gene networks and pathways were consistent with the pathological changes that are observed in the breast muscle of heat-stressed broilers.

  15. Modeling and Control of a Parallel Waste Heat Recovery System for Euro-VI Heavy-Duty Diesel Engines

    NARCIS (Netherlands)

    Feru, E.; Willems, F.P.T.; Jager, B. de; Steinbuch, M.

    2014-01-01

    This paper presents the modeling and control of a waste heat recovery system for a Euro-VI heavy-duty truck engine. The considered waste heat recovery system consists of two parallel evaporators with expander and pumps mechanically coupled to the engine crankshaft. Compared to previous work, the

  16. Volumetric composition in composites and historical data

    DEFF Research Database (Denmark)

    Lilholt, Hans; Madsen, Bo

    2013-01-01

    guidance to the optimal combination of fibre content, matrix content and porosity content, in order to achieve the best obtainable properties. Several composite materials systems have been shown to be handleable with this model. An extensive series of experimental data for the system of cellulose fibres...... and polymer (resin) was produced in 1942 – 1944, and these data have been (re-)analysed by the volumetric composition model, and the property values for density, stiffness and strength have been evaluated. Good agreement has been obtained and some further observations have been extracted from the analysis.......The obtainable volumetric composition in composites is of importance for the prediction of mechanical and physical properties, and in particular to assess the best possible (normally the highest) values for these properties. The volumetric model for the composition of (fibrous) composites gives...

  17. Feedback control and heat transfer measurements in a Rayleigh-Bénard convection cell

    Science.gov (United States)

    Vial, M.; Hernández, R. H.

    2017-07-01

    We report experimental results on the heat transfer and instability onset of a Rayleigh-Bénard convection cell of aspect ratios 6:3:1 filled with a high Prandtl aqueous solution of glycerol under feedback control. We investigate the transient and stationary response of both local temperature readings and heat transfer fluxes on the Rayleigh Bénard cell in both conductive and convective states when we perform two independent feedback control actions on both hot and cold walls. We evaluate the performance of both controllers to maintain a temperature gradient independently if the system is below or above the convection threshold. As the convection cell can be rotated at 180° about the shorter axis of the cell, it was possible to perform transitions between thermal conduction and convection regimes and vice versa under a constant temperature difference maintained by both independent controllers. The experimental setup provided an accurate measurement of the critical Rayleigh number and the evolution of the Nusselt number as a function of the Rayleigh number in the moderately supercritical regime (R a formed by 6 transverse rolls throughout the range of Rayleigh numbers.

  18. Volumetric calibration of multi-axis machine tools through parametric way

    Science.gov (United States)

    Khan, Abdul Wahid; Chen, Wuyi

    2008-12-01

    A methodology was implemented to evolve the volumetric errors of multiaxis machine tools through a parametric way. The volumetric error was calibrated and evaluated in the workspace arbitrarily by implementing parametric methods and techniques. In parametric method linear displacement errors and angular displacement errors were measured through a laser interferometer with combination of a newly developed three-line measuring method to measure the prismatic joints for efficient and quick error meterage. Besides these, squareness errors between the axes were also quantified by using reversal method. Volumetric accuracy portrayed the real error picture between the workpiece and cutting tool or end effectors or a measuring probe. So positional errors, straightness errors, angular errors and squareness errors were quantified and transformed into volumetric accuracy by using generalized homogenous transformation matrices, whereas forward kinematics technique was used as a tool. Measured results can be used to compensate the volumetric errors to achieve high precision in manufacturing and measurement through physical compensation, making correction, adjustment or improvement through software. Reported here is the volumetric accuracy results carried on a multi-axis CNC milling machine under controlled environmental conditions and as per the standard procedure and practice.

  19. Nonequilibrium volumetric response of shocked polymers

    Energy Technology Data Exchange (ETDEWEB)

    Clements, B E [Los Alamos National Laboratory

    2009-01-01

    Polymers are well known for their non-equilibrium deviatoric behavior. However, investigations involving both high rate shock experiments and equilibrium measured thermodynamic quantities remind us that the volumetric behavior also exhibits a non-equilibrium response. Experiments supporting the notion of a non-equilibrium volumetric behavior will be summarized. Following that discussion, a continuum-level theory is proposed that will account for both the equilibrium and non-equilibrium response. Upon finding agreement with experiment, the theory is used to study the relaxation of a shocked polymer back towards its shocked equilibrium state.

  20. Mathematical model and minimal measurement system for optimal control of heated humidifiers in neonatal ventilation.

    Science.gov (United States)

    Verta, Antonella; Schena, Emiliano; Silvestri, Sergio

    2010-06-01

    The control of thermo-hygrometric conditions of gas delivered in neonatal mechanical ventilation appears to be a particularly difficult task, mainly due to the vast number of parameters to be monitored and the control strategies of heated humidifiers to be adopted. In the present paper, we describe the heat and fluid exchange occurring in a heated humidifier in mathematical terms; we analyze the sensitivity of the relative humidity of outlet gas as a function of thermo-hygrometric and fluid-dynamic parameters of delivered gas; we propose a control strategy that will enable the stability of outlet gas thermo-hygrometric conditions. The mathematical model is represented by a hyper-surface containing the functional relations between the input variables, which must be measured, and the output variables, which have to remain constant. Model sensitivity analysis shows that heated humidifier efficacy and stability of outlet gas thermo-hygrometric conditions are principally influenced by four parameters: liquid surface temperature, gas flow rate, inlet gas temperature and inlet gas relative humidity. The theoretical model has been experimentally validated in typical working conditions of neonatal applications. The control strategy has been implemented by a minimal measurement system composed of three thermometers, a humidity sensor, and a flow rate sensor, and based on the theoretical model. Outlet relative humidity, contained in the range 90+/-4% and 94+/-4%, corresponding with temperature variations in the range 28+/-2 degrees C and 38+/-2 degrees C respectively, has been obtained in the whole flow rate range typical of neonatal ventilation from 1 to 10 L/min. We conclude that in order to obtain the stability of the thermo-hygrometric conditions of the delivered gas mixture: (a) a control strategy with a more complex measurement system must be implemented (i.e. providing more input variables); (b) and the gas may also need to be pre-warmed before entering the humidifying

  1. Radiation heat transfer calculations using a control-angle, control-volume-based discrete ordinates method

    Energy Technology Data Exchange (ETDEWEB)

    Chai, J.C.; Lee, H.S.; Patankar, S.V. (Minnesota Univ., Minneapolis (United States) NASA, Lewis Research Center, Cleveland, OH (United States))

    1993-01-01

    A control-angle, control-volume-based discrete ordinates method (CA - CV DOM) is presented in this paper. A detailed formulation of the discretization equation is presented in two-dimensional Cartesian coordinate system. The procedure can be extended to curvilinear coordinate system with minor modifications. The step and modified-exponential schemes are used in this study. Present results converged to the grid independent solutions quickly and compared favorably against other published results for six test problems. 27 refs.

  2. Geometric optimization of cross-flow heat exchanger based on dynamic controllability

    Directory of Open Access Journals (Sweden)

    Alotaibi Sorour

    2008-01-01

    Full Text Available The operation of heat exchangers and other thermal equipments in the face of variable loads is usually controlled by manipulating inlet fluid temperatures or mass flow rates, where the controlled variable is usually one of the output temperatures. The aim of this work is to optimize the geometry of a tube with internal flow of water and an external cross-flow of air, based on its controllability characteristics. Controllability is a useful concept both from theoretical and practical perspective since it tells us if a particular output can be controlled by a particular input. This concept can also provide us with information about the easiest operating condition to control a particular output. A transient model of a tube in cross-flow is developed, where an implicit formulation is used for transient numerical solutions. The aspect ratio of the tube is optimized, subject to volume constraints, based on the optimum operation in terms of controllability. The reported optimized aspect ratio, water mass flow rate and controllability are studied for deferent external properties of the tube.

  3. The importance of control considerations for heat exchanger network synthesis: a case study

    Directory of Open Access Journals (Sweden)

    Oliveira S.G.

    2001-01-01

    Full Text Available Cost optimization in the synthesis decision tree often leads to a reduced degree of freedom which degrades the process's ability to reject disturbances as a consequence of low controllability. In fact, Heat Exchanger Networks (HENs obtained by traditional synthesis procedures that ignore controllability aspects must be evaluated in this context a posteriori. The aim of this work was to develop a procedure that includes RGA and SVD measures of controllability, which are solely based on steady state information, thereby freeing the synthesis procedure of the cumbersome dynamic analysis. When a structure is defined during a traditional HEN synthesis procedure, a degree of freedom analysis is approached as a simulation problem. Next, an optimization is performed, since new variables are usually added to increase the degree of freedom of the HEN in order to render it controllable. A key point in the proposed procedure is the inference of controllability based on the proposed controllability measures, which also provide a control scheme by pairing controlled and manipulated variables during the process design. A HEN reported in the literature is used to illustrate the proposed procedure. The steady state simulator Aspen Plus and the dynamic simulator Aspen Dynamics (Aspentech, Inc. were employed.

  4. Proportional and Integral Thermal Control System for Large Scale Heating Tests

    Science.gov (United States)

    Fleischer, Van Tran

    2015-01-01

    The National Aeronautics and Space Administration Armstrong Flight Research Center (Edwards, California) Flight Loads Laboratory is a unique national laboratory that supports thermal, mechanical, thermal/mechanical, and structural dynamics research and testing. A Proportional Integral thermal control system was designed and implemented to support thermal tests. A thermal control algorithm supporting a quartz lamp heater was developed based on the Proportional Integral control concept and a linearized heating process. The thermal control equations were derived and expressed in terms of power levels, integral gain, proportional gain, and differences between thermal setpoints and skin temperatures. Besides the derived equations, user's predefined thermal test information generated in the form of thermal maps was used to implement the thermal control system capabilities. Graphite heater closed-loop thermal control and graphite heater open-loop power level were added later to fulfill the demand for higher temperature tests. Verification and validation tests were performed to ensure that the thermal control system requirements were achieved. This thermal control system has successfully supported many milestone thermal and thermal/mechanical tests for almost a decade with temperatures ranging from 50 F to 3000 F and temperature rise rates from -10 F/s to 70 F/s for a variety of test articles having unique thermal profiles and test setups.

  5. Randomized controlled trial on postoperative pulmonary humidification after total laryngectomy: External humidifier versus heat and moisture exchanger

    NARCIS (Netherlands)

    Mérol, Jean-Claude; Charpiot, Anne; Langagne, Thibault; Hémar, Patrick; Ackerstaff, Annemieke H.; Hilgers, Frans J. M.

    2012-01-01

    Objectives/Hypothesis: Assessment of immediate postoperative airway humidification after total laryngectomy (TLE), comparing the use of an external humidifier (EH) with humidification through a heat and moisture exchanger (HME). Study Design: Randomized controlled trial (RCT). Methods: Fifty-three

  6. Randomized controlled trial on postoperative pulmonary humidification after total laryngectomy: external humidifier versus heat and moisture exchanger

    NARCIS (Netherlands)

    Mérol, J.-C.; Charpiot, A.; Langagne, T.; Hémar, P.; Ackerstaff, A.H.; Hilgers, F.J.M.

    2012-01-01

    Objectives/Hypothesis: Assessment of immediate postoperative airway humidification after total laryngectomy (TLE), comparing the use of an external humidifier (EH) with humidification through a heat and moisture exchanger (HME). Study Design: Randomized controlled trial (RCT). Methods: Fifty-three

  7. ANALYSIS, OPTIMAL CONTROL, AND SIMULATION OF CONDUCTIVE-RADIATIVE HEAT TRANSFER

    Directory of Open Access Journals (Sweden)

    Peter Philip

    2011-01-01

    Full Text Available This article surveys recent results regarding the existence of weaksolutions to quasilinear partial differential equations(PDEcouplednonlocally by the integral operator of the radiosity equation, modeling conductive-radiative heat transfer. Both the stationary and the transient case are considered. For the stationary case, an optimal control problem with control constraints is presented withfirst-order necessary optimality conditions, where recent results on the solution theory of the linearized state equation allow to close a previous gap.Afinite volume scheme for the discretization of the stationary system is described and, based on this scheme, a numerical computation of the temperaturefield(solution of the state equationis shown as well as the numerical solution to a realistic control problem in the context of industrial applications in crystal growth.

  8. Influence of controlling vibrations on heat transfer in floating zone crystal growth*

    Science.gov (United States)

    Fedyushkin, A. I.

    The crystal growth processes of monocrystals are strongly vibrational sensitive systems and in particular it concerns to a floating zone method as presence of a free surface and two fronts of crystallization and melting that aggravate it The given work is devoted to numerical investigations of the influence of controlling vibrations on heat transfer during crystal growth by floating zone technique Normal and weightless environment conditions are considered Mathematical simulation is performed on the numerical solutions of basis unsteady Navier-Stokes equations for incompressible fluid flows and energy equation 2D axisymmetric geometry was used in model Marangoni convection and radiation condition on the curvature free surface were taken in account The calculations of the shape of a free surface of a liquid zone and influences on it of a corner of wetting force of weight and size of factor of a superficial tension are carried out The simulations of convective heat transfer for real curvature free surface of a liquid zone with and without the taking into account of the following factors parameters of radiation rotations natural and Marangoni convection and vibrations are carried out The given calculations are carried out for semiconductors melts with Prandtl number Pr 1 and for oxides Pr 1 The influence of vibrations of a crystal on melt flow and on the wide of dynamic and thermal boundary layers at melt-crystal interface is studied The action of vibrations on an enhancement of heat fluxes at the melt crystal interface is shown

  9. Heat Tolerance of the Brown Recluse Spider (Araneae: Sicariidae): Potential for Pest Control.

    Science.gov (United States)

    Cramer, Kenneth L; Zagar, Lindsey M

    2016-02-01

    The brown recluse spider, Loxosceles reclusa Gertsch & Mulaik, is a well-known venomous spider common in the south-central United States where infestations can reach thousands of individuals in a single structure. Bites from this spider pose a risk of dermonecrotic lesions (loxoscelism) or, rarely, more serious systemic effects. The heat tolerance of this spider is understudied but may offer an alternative pest control solution to pesticides or fumigation, both of which have their disadvantages. We subjected brown recluse spiders to increasing temperatures to establish the upper lethal temperature (LT). Using probit analysis to generate probability of mortality at increasing temperatures, we then exposed adult spiders to the observed LT50 to simulate whole-room heat treatment. Laboratory results predict exposure to 48°C for 130 min will achieve 100% mortality of adult spiders. Field tests need to be conducted to determine the efficacy of heat treatment in a variety of real-world situations. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Control of Hyperbolic Heat Transfer Mechanisms Application to the Distributed Concentrated Solar Collectors

    KAUST Repository

    Elmetennani, Shahrazed

    2017-04-01

    This dissertation addresses the flow control problem in hyperbolic heat transfer mechanisms. It raises in concentrated distributed solar collectors to enhance their production efficiency under the unpredictable variations of the solar energy and the external disturbances. These factors which are either locally measured (the solar irradiance) or inaccessible for measurement (the collectors’ cleanliness) affect the source term of the distributed model and represent a major difficulty for the control design. Moreover, the temperature in the collector can only be measured at the boundaries. In this dissertation, we propose new adaptive control approaches to provide the adequate level of heat while coping with the unpredictable varying disturbances. First, we design model based control strategies for a better efficiency, in terms of accuracy and response time, with a relatively reduced complexity. Second, we enhance the controllers with on-line adaptation laws to continuously update the efficient value of the external conditions. In this study, we approach the control problem using both, the infinite dimensional model (late lumping) and a finite dimensional approximate representation (early lumping). For the early lumping approach, we introduce a new reduced order bilinear approximate model for system analysis and control design. This approximate state representation is then used to derive a nonlinear state feedback resorting to Lyapunov stability theory. To compensate for the external disturbances and the approximation uncertainties, an adaptive controller is developed based on a phenomenological representation of the system dynamics. For the late lumping approach, we propose two PDE based controllers by stabilization of the reference tracking error distributed profile. The control laws are explicitly defined as functions of the available measurement. The first one is obtained using a direct approach for error stabilization while the second one is derived through a

  11. Density control and plasma edge characterisation of ECRH heated plasmas in the TJ-II stellarator

    Energy Technology Data Exchange (ETDEWEB)

    Tabares, F.L. E-mail: tabares@ciemat.es; Tafalla, D.; Branas, B.; Cal, E. de la; Garcia-Cortes, I.; Estrada, T.; Pastor, I.; Herranz, J.; Luna, E. de la; Medina, F

    2001-03-01

    In the 1999 experimental campaign, the Spanish stellarator, TJ-II (R=1.5 m, a<0.22 m, B{sub 0}<1 T) has been operated under a broad range of parameters, including changes in the magnetic configuration, working gas (H{sub 2} vs He), microwave heating power (100-600 kW, two independent lines at 53.2 GHz, second harmonic X-mode) and plasma-wall interaction conditions (wall conditioning, poloidal vs toroidal limiter). Although a close coupling between the plasmas and the TJ-II vacuum vessel is naturally present in most conditions, a good control of central plasma values has been achieved for both atomic species even under conditions close to the highest power density (n{sub e0}<1.7x10{sup 13} cm{sup -3}, T{sub e0}<1.3 keV). For this purpose, a careful control of wall conditions has been required. In addition, the low electron density and temperature of TJ-II edge plasmas have led to a significant reduction of the expected plasma-wall interaction. In this work, the issues of plasma density control and edge characteristics for the different plasma species and heating power are addressed. Results of new edge diagnostics, as a thermal lithium beam and a supersonic helium beam, among others are presented.

  12. Temperature distribution in Risø Flexhouse Room 3 with different heating control principles

    DEFF Research Database (Denmark)

    Simone, Angela; Rode, Carsten

    2009-01-01

    in winter and spring 2009 to study the distribution of local temperatures in the room – particularly with the purpose to compare with the temperature measured and logged by the heating control sensor which was already installed in the room. The measured data shall be used together with mathematical models......This report presents the measurements of local thermal conditions in one room (“Room 3”) of the so-called “Flexouse” located at Risø DTU. The house is part of Risø DTU’s SYSLAB facility used to study the interaction of different facilities that supply and use energy. The facility has been used...

  13. Geochemical implications of production and storage control by coupling a direct-use geothermal system with heat networks

    OpenAIRE

    Daniilidis, Alexandros; Scholten, Tjardo; Hooghiem, Joram; De Persis, Claudio; Herber, Rien

    2017-01-01

    This paper outlines a method in which the heat production of a geothermal system is controlled in relation to the demand from a district-heating network. A model predictive control strategy is designed, which uses volume measurements in the storage tank, and predictions of the demand, to regulate the production of the geothermal system in real time. The implications of such time-varying production for the reservoir are investigated using a 2D reactive transport reservoir model. As a case stud...

  14. Multi-scale Control and Enhancement of Reactor Boiling Heat Flux by Reagents and Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Manglik, R M; Athavale, A; Kalaikadal, D S; Deodhar, A; Verma, U

    2011-09-02

    The phenomenological characterization of the use of non-invasive and passive techniques to enhance the boiling heat transfer in water has been carried out in this extended study. It provides fundamental enhanced heat transfer data for nucleate boiling and discusses the associated physics with the aim of addressing future and next-generation reactor thermal-hydraulic management. It essentially addresses the hypothesis that in phase-change processes during boiling, the primary mechanisms can be related to the liquid-vapor interfacial tension and surface wetting at the solidliquid interface. These interfacial characteristics can be significantly altered and decoupled by introducing small quantities of additives in water, such as surface-active polymers, surfactants, and nanoparticles. The changes are fundamentally caused at a molecular-scale by the relative bulk molecular dynamics and adsorption-desorption of the additive at the liquid-vapor interface, and its physisorption and electrokinetics at the liquid-solid interface. At the micro-scale, the transient transport mechanisms at the solid-liquid-vapor interface during nucleation and bubblegrowth can be attributed to thin-film spreading, surface-micro-cavity activation, and micro-layer evaporation. Furthermore at the macro-scale, the heat transport is in turn governed by the bubble growth and distribution, macro-layer heat transfer, bubble dynamics (bubble coalescence, collapse, break-up, and translation), and liquid rheology. Some of these behaviors and processes are measured and characterized in this study, the outcomes of which advance the concomitant fundamental physics, as well as provide insights for developing control strategies for the molecular-scale manipulation of interfacial tension and surface wetting in boiling by means of polymeric reagents, surfactants, and other soluble surface-active additives.

  15. Dynamic m6A mRNA methylation directs translational control of heat shock response

    Science.gov (United States)

    Zhou, Jun; Wan, Ji; Gao, Xiangwei; Zhang, Xingqian; Qian, Shu-Bing

    2015-01-01

    The most abundant mRNA post-transcriptional modification is N6-methyladenosine (m6A) that has broad roles in RNA biology1-5. In mammalian cells, the asymmetric distribution of m6A along mRNAs leaves relatively less methylation in the 5′ untranslated region (5′UTR) compared to other regions6,7. However, whether and how 5′UTR methylation is regulated is poorly understood. Despite the crucial role of the 5′UTR in translation initiation, very little is known whether m6A modification influences mRNA translation. Here we show that in response to heat shock stress, m6A is preferentially deposited to the 5′UTR of newly transcribed mRNAs. We found that the dynamic 5′UTR methylation is a result of stress-induced nuclear localization of YTHDF2, a well characterized m6A “reader”. Upon heat shock stress, the nuclear YTHDF2 preserves 5′UTR methylation of stress-induced transcripts by limiting the m6A “eraser” FTO from demethylation. Remarkably, the increased 5′UTR methylation in the form of m6A promotes cap-independent translation initiation, providing a mechanism for selective mRNA translation under heat shock stress. Using Hsp70 mRNA as an example, we demonstrate that a single site m6A modification in the 5′UTR enables translation initiation independent of the 5′ end m7G cap. The elucidation of the dynamic feature of 5′UTR methylation and its critical role in cap-independent translation not only expands the breadth of physiological roles of m6A, but also uncovers a previously unappreciated translational control mechanism in heat shock response. PMID:26458103

  16. Green chemistry volumetric titration kit for pharmaceutical ...

    African Journals Online (AJOL)

    Stopcock SC and Spring Sp models of Econoburette (Calibrated, RTC (NR), Ministry of Small Scale Industries, Government of India), developed for semimicro volumetric titration of pharmaceutical formulations are reported. These are economized and risk free titration where pipette is replaced by an inbuilt pipette and ...

  17. Application of multi-model switching predictive functional control on the temperature system of an electric heating furnace.

    Science.gov (United States)

    Xu, Weide; Zhang, Junfeng; Zhang, Ridong

    2017-05-01

    A method of multi-model switching based predictive functional control is proposed and applied to the temperature control system of an electric heating furnace. The control strategies provide the effective and independent control modes of the electric heating furnace temperature in order to obtain improved control performance. The method depends on conventional implementation of the multi-model switching state, which requires some endeavors to tune the switching model in the model predictive control and allows a reduction of the calculation compared with the weighted multiple model algorithms. In order to test the advantage of the proposed method, experimental equipment is set up and experiments are done on the temperature process of a heating furnace, which verify the validity and effectiveness of the proposed algorithm. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  18. Is the gas hydrate film growth controlled by intrinsic kinetic or heat transfer?

    Energy Technology Data Exchange (ETDEWEB)

    Peng, B.Z.; Chen, G.J.; Sun, C.Y.; Yang, L.Y.; Luo, H. [China Univ. of Petroleum, Beijing (China). State Key Laboratory of Heavy Oil Processing

    2008-07-01

    Gas hydrates are non-stoichiometric crystalline inclusion compounds. They are composed of water molecules encaging guest gas molecules like natural gas components. When water contacts with a hydrate former in liquid or a gas state under suitable temperature and pressure conditions, hydrates usually form and grow in the form of a film at the interface between the two fluid phases. The growth behavior of this type of film is of significant importance with respect to the various components of hydrate production, such as the storage and transportation of natural gas and desalination. However, questions remain regarding the control steps of hydrate film growth. This paper discussed a study that systematically measured the lateral growth rates of methane (CH{sub 4}) and carbon dioxide (CO{sub 2}) hydrates film by suspending individual gas bubbles in water. In order to determine the correlation between the hydrate film growth rate and the driving force, modeling of hydrate film growth by intrinsic kinetics and heat transfer was conducted. The temperature difference between the moving hydrate film front and the bulk water was calculated to evaluate the contribution of heat transfer to hydrate film growth rate. The paper discussed the experiment, with reference to the equipment and material; experimental procedure; and data processing. A simulation of the hydrate film growth revealed that heat transfer had little contribution to hydrate film growth, and the intrinsic kinetic was the main control step for CH{sub 4} and CO{sub 2} hydrate film growth. 16 refs., 2 tabs., 5 figs.

  19. HEAT RECUPERATION

    Directory of Open Access Journals (Sweden)

    S. L. Rovin

    2011-01-01

    Full Text Available Heat recovery is an effective method of shortening specific energy consumption. new constructions of recuperators for heating and cupola furnaces have been designed and successfully introduced. two-stage recuperator with computer control providing blast heating up to 600 °C and reducing fuel consumption by 30% is of special interest.

  20. Nonlinear observer-based Lyapunov boundary control of distributed heat transfer mechanisms for membrane distillation plant

    KAUST Repository

    Eleiwi, Fadi

    2016-09-19

    This paper presents a nonlinear observer-based Lyapunov control for a membrane distillation (MD) process. The control considers the inlet temperatures of the feed and the permeate solutions as inputs, transforming it to boundary control process, and seeks to maintain the temperature difference along the membrane boundaries around a sufficient level to promote water production. MD process is modeled with advection diffusion equation model in two dimensions, where the diffusion and convection heat transfer mechanisms are best described. Model analysis, effective order reduction and parameters physical interpretation, are provided. Moreover, a nonlinear observer has been designed to provide the control with estimates of the temperature evolution at each time instant. In addition, physical constraints are imposed on the control to have an acceptable range of feasible inputs, and consequently, better energy consumption. Numerical simulations for the complete process with real membrane parameter values are provided, in addition to detailed explanations for the role of the controller and the observer. (C) 2016 Elsevier Ltd. All rights reserved.

  1. Heating and thermal control of brazing technique to break contamination path for potential Mars sample return

    Science.gov (United States)

    Bao, Xiaoqi; Badescu, Mircea; Sherrit, Stewart; Bar-Cohen, Yoseph; Campos, Sergio

    2017-04-01

    The potential return of Mars sample material is of great interest to the planetary science community, as it would enable extensive analysis of samples with highly sensitive laboratory instruments. It is important to make sure such a mission concept would not bring any living microbes, which may possibly exist on Mars, back to Earth's environment. In order to ensure the isolation of Mars microbes from Earth's Atmosphere, a brazing sealing and sterilizing technique was proposed to break the Mars-to-Earth contamination path. Effectively, heating the brazing zone in high vacuum space and controlling the sample temperature for integrity are key challenges to the implementation of this technique. The break-thechain procedures for container configurations, which are being considered, were simulated by multi-physics finite element models. Different heating methods including induction and resistive/radiation were evaluated. The temperature profiles of Martian samples in a proposed container structure were predicted. The results show that the sealing and sterilizing process can be controlled such that the samples temperature is maintained below the level that may cause damage, and that the brazing technique is a feasible approach to breaking the contamination path.

  2. {delta}-FeOOH: a superparamagnetic material for controlled heat release under AC magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Chagas, Poliane; Candido da Silva, Adilson [ICEx, Universidade Federal de Minas Gerais, Departamento de Quimica (Brazil); Caetano Passamani, Edson [Universidade Federal do Espirito Santo, Departamento de Fisica (Brazil); Ardisson, Jose Domingos [Centro de Desenvolvimento da Tecnologia Nuclear (Brazil); Alves de Oliveira, Luiz Carlos [ICEx, Universidade Federal de Minas Gerais, Departamento de Quimica (Brazil); Domingos Fabris, Jose [Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM) (Brazil); Paniago, Roberto M. [ICEx, Universidade Federal de Minas Gerais, Departamento de Fisica (Brazil); Monteiro, Douglas Santos; Pereira, Marcio Cesar, E-mail: mcpqui@gmail.com [Instituto de Ciencia, Engenharia e Tecnologia, UFVJM (Brazil)

    2013-04-15

    Experimental evidences on its in vitro use reveal that {delta}-FeOOH is a material that release-controlled amount of heat if placed under an AC magnetic field. {delta}-FeOOH nanoparticles were prepared by precipitating Fe(OH){sub 2} in alkaline solution followed by fast oxidation with H{sub 2}O{sub 2}. XRD and {sup 57}Fe Moessbauer spectroscopy data confirmed that {delta}-FeOOH is indeed the only iron-bearing compound in the produced sample. TEM images evidence that the averaged particle sizes for this {delta}-FeOOH sample is 23 nm. Magnetization measurements indicate that these {delta}-FeOOH particles behave superparamagnetically at 300 K; its saturation magnetization was found to be 13.2 emu g{sup -1}; the coercivity and the remnant magnetization were zero at 300 K. The specific absorption rate values at 225 kHz were 2.1, 6.2, and 34.2 W g{sup -1}, under 38, 64, and 112 mT, respectively. The release rate of heat can be directly controlled by changing the mass of {delta}-FeOOH nanoparticles. In view of these findings, the so-prepared {delta}-FeOOH is a real alternative to be further tested as a material for medical practices in therapies involving magnetic hyperthermia as in clinical oncology.

  3. District heating in Lyons: self-monitoring and administrative control; Chauffage urbain de Lyon: autosurveillance et controle de l`Administration

    Energy Technology Data Exchange (ETDEWEB)

    Lartigue, D. [SLEC / PRODITH, 69 - Lyon (France)

    1996-12-31

    The district heat and cold system of Lyon city (France) is presented, with emphasis on the environmental performances of its boiler, burner and dust cleaning systems. Pollutant emissions are continuously monitored, controlled and regulated: the sensing and monitoring system is described together with the data acquisition and processing systems, allowing for a real time control of the plants and the whole heating system. Relations with the local administration and audits for ISO 14000 certification are also discussed

  4. Automatic diameter control system applied to the laser heated pedestal growth technique

    Directory of Open Access Journals (Sweden)

    Andreeta M.R.B.

    2003-01-01

    Full Text Available We described an automatic diameter control system (ADC, for the laser heated pedestal growth technique, that reduces the diameter fluctuations in oxide fibers grown from unreacted and non-sinterized pedestals, to less than 2% of the average fiber diameter, and diminishes the average diameter fluctuation, over the entire length of the fiber, to less than 1%. The ADC apparatus is based on an artificial vision system that controls the pulling speed and the height of the molten zone within a precision of 30 mum. We also show that this system can be used for periodic in situ axial doping the fiber. Pure and Cr3+ doped LaAlO3 and pure LiNbO3 were usedas model materials.

  5. Automatic control of electric thermal storage (heat) under real-time pricing. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Daryanian, B.; Tabors, R.D.; Bohn, R.E. [Tabors Caramanis and Associates, Inc. (United States)

    1995-01-01

    Real-time pricing (RTP) can be used by electric utilities as a control signal for responsive demand-side management (DSM) programs. Electric thermal storage (ETS) systems in buildings provide the inherent flexibility needed to take advantage of variations in prices. Under RTP, optimal performance for ETS operations is achieved under market conditions where reductions in customers` costs coincide with the lowering of the cost of service for electric utilities. The RTP signal conveys the time-varying actual marginal cost of the electric service to customers. The RTP rate is a combination of various cost components, including marginal generation fuel and maintenance costs, marginal costs of transmission and distribution losses, and marginal quality of supply and transmission costs. This report describes the results of an experiment in automatic control of heat storage systems under RTP during the winter seasons of 1989--90 and 1990--91.

  6. Effect of sacrum-perineum heat therapy on active phase labor pain and client satisfaction: a randomized, controlled trial study.

    Science.gov (United States)

    Taavoni, Simin; Abdolahian, Somayeh; Haghani, Hamid

    2013-09-01

    Reduction of labor pain is one of the most important aspects of obstetric care. Heat therapy, typically applied to the woman's back, lower abdomen, groin, and/or perineum during last stage of labor, is an easy pain relief method that does not require highly skilled care. The effectiveness of heat therapy applied to the perineum during the first stage of labor has not been evaluated. This study aimed to evaluate the effectiveness of heat therapy for pain and woman's satisfaction during physiological labor. Sixty primiparous women aged 18-35 years old were randomly assigned to heat therapy and control groups. Pain and satisfaction scores were measured by visual analog scale. The measurements of satisfaction were accomplished after birth. Data were analyzed by using the t-test and chi-square Mean pain scores in the heat therapy group were significantly lower than the control group (P < 0.05). The mean satisfaction score in the heat therapy group was significantly higher than in the control group (P < 0.05). Heat therapy, an inexpensive complementary treatment with low risk, can reduce the intensity of pain and increase mothers' satisfaction with care during the active phase of labor. Wiley Periodicals, Inc.

  7. Demand control on room level of the supply air temperature in an air heating and ventilation system

    DEFF Research Database (Denmark)

    Polak, Joanna; Afshari, Alireza; Bergsøe, Niels Christian

    2017-01-01

    The aim of this study was to investigate a new strategy for control of supply air temperature in an integrated air heating and ventilation system. The new strategy enables demand control of supply air temperature in individual rooms. The study is based on detailed dynamic simulations of a combined...... air heating and ventilation system in a high performance single family house using BSim simulation software. The provision of the desired thermal conditions in different rooms was examined. Results show that the new control strategy can facilitate maintaining of desired temperatures in various rooms....... Moreover, this control strategy enables controlled temperature differentiation between rooms within the house and therefore provides flexibility and better balance in heat delivery. Consequently, the thermal conditions in the building can be improved....

  8. Investigation of the Dominant Processes controlling Volume, Heat, and Freshwater Transports through the Bering Strait

    Science.gov (United States)

    Nguyen, A. T.; Woodgate, R. A.; Heimbach, P.

    2016-02-01

    The 85-km wide Bering Strait serves as the only connection between the Pacific and Arctic oceans. Recent observations have shown increases in northward volume, heat and freshwater fluxes through this narrow and shallow strait, with implications for the prolongation of the ice-free season and enhancement of nutrient supply to the ecosystems in the Chukchi Sea. Further downstream the increased flux influences watermass transformations, heat and freshwater budgets, and stratification in the upper Arctic Ocean. Thus, quantifying the mechanisms that control the mean and variability of the flow through this vital gateway is important for understanding and predicting changes in the Arctic. Here, to identify these key mechanisms, we use 14 years of mooring observations from the Bering Strait and the non-linear inverse-modeling framework of the Arctic Sub-polar gyre sTate Estimate (ASTE). ASTE is a synthesis of the MITgcm coupled ocean-sea ice model with all available satellite and in-situ observations of sea ice and ocean, including hydrographic and mooring data from the Beaufort Sea and the major Arctic gateways (Fram, Bering, and Davis straits), and is developed using the estimation infrastructure of the ECCO consortium. In ASTE's optimization mode, after 19 iterations, misfits to ITP hydrography and SSM/I ice concentration have reduced by 80% and 50% respectively. With ASTE as the baseline solution, we use the "adjoint" tool to compute the sensitivity of the model transports of volume and water properties at the Bering Strait to a set of control variables including ocean hydrography and atmospheric forcing. The partition of dominant sensitivities is connected to the data in two ways: the data serve as a guide to the interpretation of the controlling process while the model sensitivity can provide insights into processes which can be further tested with additional observations.

  9. Fault Diagnosis for the Heat Exchanger of the Aircraft Environmental Control System Based on the Strong Tracking Filter

    Science.gov (United States)

    Ma, Jian; Lu, Chen; Liu, Hongmei

    2015-01-01

    The aircraft environmental control system (ECS) is a critical aircraft system, which provides the appropriate environmental conditions to ensure the safe transport of air passengers and equipment. The functionality and reliability of ECS have received increasing attention in recent years. The heat exchanger is a particularly significant component of the ECS, because its failure decreases the system’s efficiency, which can lead to catastrophic consequences. Fault diagnosis of the heat exchanger is necessary to prevent risks. However, two problems hinder the implementation of the heat exchanger fault diagnosis in practice. First, the actual measured parameter of the heat exchanger cannot effectively reflect the fault occurrence, whereas the heat exchanger faults are usually depicted by utilizing the corresponding fault-related state parameters that cannot be measured directly. Second, both the traditional Extended Kalman Filter (EKF) and the EKF-based Double Model Filter have certain disadvantages, such as sensitivity to modeling errors and difficulties in selection of initialization values. To solve the aforementioned problems, this paper presents a fault-related parameter adaptive estimation method based on strong tracking filter (STF) and Modified Bayes classification algorithm for fault detection and failure mode classification of the heat exchanger, respectively. Heat exchanger fault simulation is conducted to generate fault data, through which the proposed methods are validated. The results demonstrate that the proposed methods are capable of providing accurate, stable, and rapid fault diagnosis of the heat exchanger. PMID:25823010

  10. Fault diagnosis for the heat exchanger of the aircraft environmental control system based on the strong tracking filter.

    Science.gov (United States)

    Ma, Jian; Lu, Chen; Liu, Hongmei

    2015-01-01

    The aircraft environmental control system (ECS) is a critical aircraft system, which provides the appropriate environmental conditions to ensure the safe transport of air passengers and equipment. The functionality and reliability of ECS have received increasing attention in recent years. The heat exchanger is a particularly significant component of the ECS, because its failure decreases the system's efficiency, which can lead to catastrophic consequences. Fault diagnosis of the heat exchanger is necessary to prevent risks. However, two problems hinder the implementation of the heat exchanger fault diagnosis in practice. First, the actual measured parameter of the heat exchanger cannot effectively reflect the fault occurrence, whereas the heat exchanger faults are usually depicted by utilizing the corresponding fault-related state parameters that cannot be measured directly. Second, both the traditional Extended Kalman Filter (EKF) and the EKF-based Double Model Filter have certain disadvantages, such as sensitivity to modeling errors and difficulties in selection of initialization values. To solve the aforementioned problems, this paper presents a fault-related parameter adaptive estimation method based on strong tracking filter (STF) and Modified Bayes classification algorithm for fault detection and failure mode classification of the heat exchanger, respectively. Heat exchanger fault simulation is conducted to generate fault data, through which the proposed methods are validated. The results demonstrate that the proposed methods are capable of providing accurate, stable, and rapid fault diagnosis of the heat exchanger.

  11. Fault diagnosis for the heat exchanger of the aircraft environmental control system based on the strong tracking filter.

    Directory of Open Access Journals (Sweden)

    Jian Ma

    Full Text Available The aircraft environmental control system (ECS is a critical aircraft system, which provides the appropriate environmental conditions to ensure the safe transport of air passengers and equipment. The functionality and reliability of ECS have received increasing attention in recent years. The heat exchanger is a particularly significant component of the ECS, because its failure decreases the system's efficiency, which can lead to catastrophic consequences. Fault diagnosis of the heat exchanger is necessary to prevent risks. However, two problems hinder the implementation of the heat exchanger fault diagnosis in practice. First, the actual measured parameter of the heat exchanger cannot effectively reflect the fault occurrence, whereas the heat exchanger faults are usually depicted by utilizing the corresponding fault-related state parameters that cannot be measured directly. Second, both the traditional Extended Kalman Filter (EKF and the EKF-based Double Model Filter have certain disadvantages, such as sensitivity to modeling errors and difficulties in selection of initialization values. To solve the aforementioned problems, this paper presents a fault-related parameter adaptive estimation method based on strong tracking filter (STF and Modified Bayes classification algorithm for fault detection and failure mode classification of the heat exchanger, respectively. Heat exchanger fault simulation is conducted to generate fault data, through which the proposed methods are validated. The results demonstrate that the proposed methods are capable of providing accurate, stable, and rapid fault diagnosis of the heat exchanger.

  12. Analysis and Experimental Investigation of Optimum Design of Thermoelectric Cooling/Heating System for Car Seat Climate Control (CSCC)

    Science.gov (United States)

    Elarusi, Abdulmunaem; Attar, Alaa; Lee, HoSung

    2018-02-01

    The optimum design of a thermoelectric system for application in car seat climate control has been modeled and its performance evaluated experimentally. The optimum design of the thermoelectric device combining two heat exchangers was obtained by using a newly developed optimization method based on the dimensional technique. Based on the analytical optimum design results, commercial thermoelectric cooler and heat sinks were selected to design and construct the climate control heat pump. This work focuses on testing the system performance in both cooling and heating modes to ensure accurate analytical modeling. Although the analytical performance was calculated using the simple ideal thermoelectric equations with effective thermoelectric material properties, it showed very good agreement with experiment for most operating conditions.

  13. Temperature control at DBS electrodes using a heat sink: experimentally validated FEM model of DBS lead architecture.

    Science.gov (United States)

    Elwassif, Maged M; Datta, Abhishek; Rahman, Asif; Bikson, Marom

    2012-08-01

    There is a growing interest in the use of deep brain stimulation (DBS) for the treatment of medically refractory movement disorders and other neurological and psychiatric conditions. The extent of temperature increases around DBS electrodes during normal operation (joule heating and increased metabolic activity) or coupling with an external source (e.g. magnetic resonance imaging) remains poorly understood and methods to mitigate temperature increases are being actively investigated. We developed a heat transfer finite element method (FEM) simulation of DBS incorporating the realistic architecture of Medtronic 3389 leads. The temperature changes were analyzed considering different electrode configurations, stimulation protocols and tissue properties. The heat-transfer model results were then validated using micro-thermocouple measurements during DBS lead stimulation in a saline bath. FEM results indicate that lead design (materials and geometry) may have a central role in controlling temperature rise by conducting heat. We show how modifying lead design can effectively control temperature increases. The robustness of this heat-sink approach over complimentary heat-mitigation technologies follows from several features: (1) it is insensitive to the mechanisms of heating (e.g. nature of magnetic coupling); (2) it does not interfere with device efficacy; and (3) can be practically implemented in a broad range of implanted devices without modifying the normal device operations or the implant procedure.

  14. Temperature control at DBS electrodes using a heat sink: experimentally validated FEM model of DBS lead architecture

    Science.gov (United States)

    Elwassif, Maged M.; Datta, Abhishek; Rahman, Asif; Bikson, Marom

    2012-08-01

    There is a growing interest in the use of deep brain stimulation (DBS) for the treatment of medically refractory movement disorders and other neurological and psychiatric conditions. The extent of temperature increases around DBS electrodes during normal operation (joule heating and increased metabolic activity) or coupling with an external source (e.g. magnetic resonance imaging) remains poorly understood and methods to mitigate temperature increases are being actively investigated. We developed a heat transfer finite element method (FEM) simulation of DBS incorporating the realistic architecture of Medtronic 3389 leads. The temperature changes were analyzed considering different electrode configurations, stimulation protocols and tissue properties. The heat-transfer model results were then validated using micro-thermocouple measurements during DBS lead stimulation in a saline bath. FEM results indicate that lead design (materials and geometry) may have a central role in controlling temperature rise by conducting heat. We show how modifying lead design can effectively control temperature increases. The robustness of this heat-sink approach over complimentary heat-mitigation technologies follows from several features: (1) it is insensitive to the mechanisms of heating (e.g. nature of magnetic coupling); (2) it does not interfere with device efficacy; and (3) can be practically implemented in a broad range of implanted devices without modifying the normal device operations or the implant procedure.

  15. Cockayne syndrome: a diffusion tensor imaging and volumetric study.

    Science.gov (United States)

    Koob, Mériam; Rousseau, François; Laugel, Vincent; Meyer, Nicolas; Armspach, Jean-Paul; Girard, Nadine; Dietemann, Jean-Louis

    2016-11-01

    Cockayne syndrome (CS) is a rare disorder characterized by severe brain atrophy, white matter (WM) hypomyelination and basal ganglia calcifications. This study aimed to quantify atrophy and WM abnormalities using diffusion tensor imaging (DTI) and volumetric analysis, to evaluate possible differences between CS subtypes and to determine whether DTI findings may correspond to a hypomyelinating disorder. 14 patients with CS and 14 controls underwent brain MRI including DTI and a volumetric three-dimensional T 1 weighted sequence. DTI analysis was made through regions of interest within the whole brain to obtain fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values and in the left centrum semiovale to obtain DTI eigenvalues. The Student's t-test was used to compare patients and controls, and CS subtypes. Given the small number of patients with CS, they were pooled into two groups: moderate (CS1/CS3) and severe (CS2/cerebro-oculo-facio-skeletal syndrome). Total brain volume in CS was reduced by 57%, predominantly in the infratentorial area (68%) (p < 0.001). Total brain volume reduction was greater in the severe group, but there was no difference in the degree of infratentorial atrophy in the two groups (p = 0.7). Mean FA values were lower, whereas ADC was higher in most of the WM in patients with CS (p < 0.05). ADC in the splenium of the corpus callosum and the posterior limb of the internal capsule and FA in the cerebral peduncles were significantly different between the two groups (p < 0.05). Mean ADC values corresponded to a hypomyelinating disorder. All DTI eigenvalues were higher in patients with CS, mainly for transverse diffusivity (+51%) (p < 0.001). DTI and volumetric analysis provide quantitative information for the characterization of CS and may be particularly useful for evaluating therapeutic intervention. Advances in knowledge: DTI combined with volumetric analysis provides additional information useful for not

  16. Transformed Fourier and Fick equations for the control of heat and mass diffusion

    Directory of Open Access Journals (Sweden)

    S. Guenneau

    2015-05-01

    Full Text Available We review recent advances in the control of diffusion processes in thermodynamics and life sciences through geometric transforms in the Fourier and Fick equations, which govern heat and mass diffusion, respectively. We propose to further encompass transport properties in the transformed equations, whereby the temperature is governed by a three-dimensional, time-dependent, anisotropic heterogeneous convection-diffusion equation, which is a parabolic partial differential equation combining the diffusion equation and the advection equation. We perform two dimensional finite element computations for cloaks, concentrators and rotators of a complex shape in the transient regime. We precise that in contrast to invisibility cloaks for waves, the temperature (or mass concentration inside a diffusion cloak crucially depends upon time, its distance from the source, and the diffusivity of the invisibility region. However, heat (or mass diffusion outside cloaks, concentrators and rotators is unaffected by their presence, whatever their shape or position. Finally, we propose simplified designs of layered cylindrical and spherical diffusion cloaks that might foster experimental efforts in thermal and biochemical metamaterials.

  17. Transformed Fourier and Fick equations for the control of heat and mass diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Guenneau, S.; Petiteau, D.; Zerrad, M.; Amra, C. [Aix–Marseille Université, UMR CNRS 7249, Centrale Marseille, Institut Fresnel, 13013 Marseille (France); Puvirajesinghe, T. [Aix–Marseille Université, UMR CNRS 7258, UMR INSERM 1068, Centre de Recherche en Cancérologie de Marseille, Institut Paoli-Calmettes, 13009 Marseille (France)

    2015-05-15

    We review recent advances in the control of diffusion processes in thermodynamics and life sciences through geometric transforms in the Fourier and Fick equations, which govern heat and mass diffusion, respectively. We propose to further encompass transport properties in the transformed equations, whereby the temperature is governed by a three-dimensional, time-dependent, anisotropic heterogeneous convection-diffusion equation, which is a parabolic partial differential equation combining the diffusion equation and the advection equation. We perform two dimensional finite element computations for cloaks, concentrators and rotators of a complex shape in the transient regime. We precise that in contrast to invisibility cloaks for waves, the temperature (or mass concentration) inside a diffusion cloak crucially depends upon time, its distance from the source, and the diffusivity of the invisibility region. However, heat (or mass) diffusion outside cloaks, concentrators and rotators is unaffected by their presence, whatever their shape or position. Finally, we propose simplified designs of layered cylindrical and spherical diffusion cloaks that might foster experimental efforts in thermal and biochemical metamaterials.

  18. Dominant control of agriculture and irrigation on urban heat island in India.

    Science.gov (United States)

    Kumar, Rahul; Mishra, Vimal; Buzan, Jonathan; Kumar, Rohini; Shindell, Drew; Huber, Matthew

    2017-10-25

    As is true in many regions, India experiences surface Urban Heat Island (UHI) effect that is well understood, but the causes of the more recently discovered Urban Cool Island (UCI) effect remain poorly constrained. This raises questions about our fundamental understanding of the drivers of rural-urban environmental gradients and hinders development of effective strategies for mitigation and adaptation to projected heat stress increases in rapidly urbanizing India. Here we show that more than 60% of Indian urban areas are observed to experience a day-time UCI. We use satellite observations and the Community Land Model (CLM) to identify the impact of irrigation and prove for the first time that UCI is caused by lack of vegetation and moisture in non-urban areas relative to cities. In contrast, urban areas in extensively irrigated landscapes generally experience the expected positive UHI effect. At night, UHI warming intensifies, occurring across a majority (90%) of India's urban areas. The magnitude of rural-urban temperature contrasts is largely controlled by agriculture and moisture availability from irrigation, but further analysis of model results indicate an important role for atmospheric aerosols. Thus both land-use decisions and aerosols are important factors governing, modulating, and even reversing the expected urban-rural temperature gradients.

  19. The use of mechanical ventilation with heat recovery for controlling radon and radondaughter concentrations in houses

    Science.gov (United States)

    Nazaroff, W. W.; Boegel, M. L.; Hollowell, C. D.; Roseme, G. D.

    An energy research house in Maryland was found to have radon concentrations far in excess of recommended guidelines. A mechanical ventilation system with heat recovery was installed in this house to test its effectiveness as an energy-efficient control technique for indoor radon. Radon concentration was monitored continuously for 2 weeks under varying ventilation conditions [0.07-0.8 air changes per hour (ach)] and radondaughter concentrations were measured by grab-sample techniques about nine times daily during this period. At ventilation rates of 0.6 ach and higher, radon-daughter levels dropped below guidelines for indoor concentrations. Comparison with other studies indicates that indoor radon buildup may be a problem in a considerable portion of houses characterized by their low infiltration rates. The use of mechanical ventilation systems with air-to-air heat exchangers may offer a practical, cost-effective and energy-efficient means of alleviating not only the radon problem specifically but also the general deterioration of indoor air quality in many houses designed or retrofitted to achieve low infiltration.

  20. Comparison of Two Potassium-Filled Gas-Controlled Heat Pipes

    Science.gov (United States)

    Bertiglia, F.; Iacomini, L.; Moro, F.; Merlone, A.

    2015-12-01

    Calibration by comparison of platinum resistance thermometers and thermocouples requires transfer media capable of providing very good short-term temperature uniformity and temperature stability over a wide temperature range. This paper describes and compares the performance of two potassium-filled gas-controlled heat pipes (GCHP) for operation over the range from 420° C to 900° C. One of the heat pipes has been in operation for more than 10 years having been operated at temperature for thousands of hours, while the other was commissioned in 2010 following recently developed improvements to both the design, assembly, and filling processes. It was found that the two devices, despite differences in age, structure, number of wells, and filling processes, realized the same temperatures within the measurement uncertainty. The results show that the potassium-filled GCHP provides a durable and high-quality transfer medium for performing thermometer calibrations with very low uncertainties, over the difficult high-temperature range from 420° C to 900° C.

  1. Introduction of fractional elements for improvising the performance of PID controller for heating furnace using AMIGO tuning technique

    Directory of Open Access Journals (Sweden)

    Amlan Basu

    2016-09-01

    Full Text Available The paper demonstrates about melioration of integer order and fractional order model of heating furnace. Both models are being placed in closed loop along with the proportional integral derivative (PID controller and fractional order proportional integral derivative (FOPID controller so that the various time domain performance characteristics of the heating furnace can be meliorated. The tuning parameters (Kp, Ki and Kd of the controllers has been found using the Astrom-Hagglund tuning technique and the differ-integrals (λ and μ are found using the Nelder-Mead optimisation technique.

  2. Combined surface and volumetric occlusion shading

    KAUST Repository

    Schott, Matthias O.

    2012-02-01

    In this paper, a method for interactive direct volume rendering is proposed that computes ambient occlusion effects for visualizations that combine both volumetric and geometric primitives, specifically tube shaped geometric objects representing streamlines, magnetic field lines or DTI fiber tracts. The proposed algorithm extends the recently proposed Directional Occlusion Shading model to allow the rendering of those geometric shapes in combination with a context providing 3D volume, considering mutual occlusion between structures represented by a volume or geometry. © 2012 IEEE.

  3. Surface hardening of titanium alloys with melting depth controlled by heat sink

    Science.gov (United States)

    Oden, Laurance L.; Turner, Paul C.

    1995-01-01

    A process for forming a hard surface coating on titanium alloys includes providing a piece of material containing titanium having at least a portion of one surface to be hardened. The piece having a portion of a surface to be hardened is contacted on the backside by a suitable heat sink such that the melting depth of said surface to be hardened may be controlled. A hardening material is then deposited as a slurry. Alternate methods of deposition include flame, arc, or plasma spraying, electrodeposition, vapor deposition, or any other deposition method known by those skilled in the art. The surface to be hardened is then selectively melted to the desired depth, dependent on the desired coating thickness, such that a molten pool is formed of the piece surface and the deposited hardening material. Upon cooling a hardened surface is formed.

  4. Optimal control of the power adiabatic stroke of an optomechanical heat engine.

    Science.gov (United States)

    Bathaee, M; Bahrampour, A R

    2016-08-01

    We consider the power adiabatic stroke of the Otto optomechanical heat engine introduced in Phys. Rev. Lett. 112, 150602 (2014)PRLTAO0031-900710.1103/PhysRevLett.112.150602. We derive the maximum extractable work of both optomechanical normal modes in the minimum time while the system experiences quantum friction effects. We show that the total work done by the system in the power adiabatic stroke is optimized by a bang-bang control. The time duration of the power adiabatic stroke is of the order of the inverse of the effective optomechanical-coupling coefficient. The optimal phase-space trajectory of the Otto cycle for both optomechanical normal modes is also obtained.

  5. Internal Thermal Control System Hose Heat Transfer Fluid Thermal Expansion Evaluation Test Report

    Science.gov (United States)

    Wieland, P. O.; Hawk, H. D.

    2001-01-01

    During assembly of the International Space Station, the Internal Thermal Control Systems in adjacent modules are connected by jumper hoses referred to as integrated hose assemblies (IHAs). A test of an IHA has been performed at the Marshall Space Flight Center to determine whether the pressure in an IHA filled with heat transfer fluid would exceed the maximum design pressure when subjected to elevated temperatures (up to 60 C (140 F)) that may be experienced during storage or transportation. The results of the test show that the pressure in the IHA remains below 227 kPa (33 psia) (well below the 689 kPa (100 psia) maximum design pressure) even at a temperature of 71 C (160 F), with no indication of leakage or damage to the hose. Therefore, based on the results of this test, the IHA can safely be filled with coolant prior to launch. The test and results are documented in this Technical Memorandum.

  6. Metabolic Heat Regenerated Temperature Swing Adsorption for CO2, Thermal and Humidity Control Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Metabolic heat regenerated Temperature Swing Adsorption (MTSA) technology is proposed for a Portable Life Support System to remove and reject heat and carbon dioxide...

  7. A Novel Heat Pipe Plate for Passive Thermal Control of Fuel Cells Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR project aims to develop a lightweight, highly thermally and electrically conductive heat pipe plate for passive removal of the heat from the individual...

  8. MR volumetric assessment of endolymphatic hydrops

    Energy Technology Data Exchange (ETDEWEB)

    Guerkov, R.; Berman, A.; Jerin, C.; Krause, E. [University of Munich, Department of Otorhinolaryngology Head and Neck Surgery, Grosshadern Medical Centre, Munich (Germany); University of Munich, German Centre for Vertigo and Balance Disorders, Grosshadern Medical Centre, Marchioninistr. 15, 81377, Munich (Germany); Dietrich, O.; Flatz, W.; Ertl-Wagner, B. [University of Munich, Institute of Clinical Radiology, Grosshadern Medical Centre, Munich (Germany); Keeser, D. [University of Munich, Institute of Clinical Radiology, Grosshadern Medical Centre, Munich (Germany); University of Munich, German Centre for Vertigo and Balance Disorders, Grosshadern Medical Centre, Marchioninistr. 15, 81377, Munich (Germany); University of Munich, Department of Psychiatry and Psychotherapy, Innenstadtkliniken Medical Centre, Munich (Germany)

    2014-10-16

    We aimed to volumetrically quantify endolymph and perilymph spaces of the inner ear in order to establish a methodological basis for further investigations into the pathophysiology and therapeutic monitoring of Meniere's disease. Sixteen patients (eight females, aged 38-71 years) with definite unilateral Meniere's disease were included in this study. Magnetic resonance (MR) cisternography with a T2-SPACE sequence was combined with a Real reconstruction inversion recovery (Real-IR) sequence for delineation of inner ear fluid spaces. Machine learning and automated local thresholding segmentation algorithms were applied for three-dimensional (3D) reconstruction and volumetric quantification of endolymphatic hydrops. Test-retest reliability was assessed by the intra-class coefficient; correlation of cochlear endolymph volume ratio with hearing function was assessed by the Pearson correlation coefficient. Endolymph volume ratios could be reliably measured in all patients, with a mean (range) value of 15 % (2-25) for the cochlea and 28 % (12-40) for the vestibulum. Test-retest reliability was excellent, with an intra-class coefficient of 0.99. Cochlear endolymphatic hydrops was significantly correlated with hearing loss (r = 0.747, p = 0.001). MR imaging after local contrast application and image processing, including machine learning and automated local thresholding, enable the volumetric quantification of endolymphatic hydrops. This allows for a quantitative assessment of the effect of therapeutic interventions on endolymphatic hydrops. (orig.)

  9. A fusible heat sink concept for extravehicular activity /EVA/ thermal control

    Science.gov (United States)

    Roebelen, G. J., Jr.

    1976-01-01

    This paper describes the preliminary design and analysis of a heat sink system, utilizing a phase change slurry material, to be used for astronaut and equipment cooling during manned space missions. During normal use, excess heat in the liquid cooling garment (LCG) coolant is transferred to a regenerable fusible heat sink. Recharge is accomplished by disconnecting the heat sink from the liquid cooling garment and placing it in an onboard freezer for simultaneous slurry refreeze and power supply recharge.

  10. Optical Coating Performance and Thermal Structure Design for Heat Reflectors of JWST Electronic Control Unit

    Science.gov (United States)

    Quijada, Manuel A.; Threat, Felix; Garrison, Matt; Perrygo, Chuck; Bousquet, Robert; Rashford, Robert

    2008-01-01

    The James Webb Space Telescope (JWST) consists of an infrared-optimized Optical Telescope Element (OTE) that is cooled down to 40 degrees Kelvin. A second adjacent component to the OTE is the Integrated Science Instrument Module, or ISIM. This module includes the electronic compartment, which provides the mounting surfaces and ambient thermally controlled environment for the instrument control electronics. Dissipating the 200 watts generated from the ISIM structure away from the OTE is of paramount importance so that the spacecraft's own heat does not interfere with the infrared light detected from distant cosmic sources. This technical challenge is overcome by a thermal subsystem unit that provides passive cooling to the ISIM control electronics. The proposed design of this thermal radiator consists of a lightweight structure made out of composite materials and low-emittance metal coatings. In this paper, we will present characterizations of the coating emittance, bidirectional reflectance, and mechanical structure design that will affect the performance of this passive cooling system.

  11. Daytime Solar Heating Controls Downy Mildew Peronospora belbahrii in Sweet Basil.

    Science.gov (United States)

    Cohen, Yigal; Rubin, Avia E

    2015-01-01

    The biotrophic oomycete Peronospora belbahrii causes a devastating downy mildew disease in sweet basil. Due to the lack of resistant cultivars current control measures rely heavily on fungicides. However, resistance to fungicides and strict regulation on their deployment greatly restrict their use. Here we report on a 'green' method to control this disease. Growth chamber studies showed that P. belbahrii could hardly withstand exposure to high temperatures; exposure of spores, infected leaves, or infected plants to 35-45 °C for 6-9 hours suppressed its survival. Therefore, daytime solar heating was employed in the field to control the downy mildew disease it causes in basil. Covering growth houses of sweet basil already infected with downy mildew with transparent infra-red-impermeable, transparent polyethylene sheets raised the daily maximal temperature during sunny hours by 11-22 °C reaching 40-58 °C (greenhouse effect). Such coverage, applied for a few hours during 1-3 consecutive days, had a detrimental effect on the survival of P. belbahrii: killing the pathogen and/or suppressing disease progress while enhancing growth of the host basil plants.

  12. Daytime Solar Heating Controls Downy Mildew Peronospora belbahrii in Sweet Basil.

    Directory of Open Access Journals (Sweden)

    Yigal Cohen

    Full Text Available The biotrophic oomycete Peronospora belbahrii causes a devastating downy mildew disease in sweet basil. Due to the lack of resistant cultivars current control measures rely heavily on fungicides. However, resistance to fungicides and strict regulation on their deployment greatly restrict their use. Here we report on a 'green' method to control this disease. Growth chamber studies showed that P. belbahrii could hardly withstand exposure to high temperatures; exposure of spores, infected leaves, or infected plants to 35-45 °C for 6-9 hours suppressed its survival. Therefore, daytime solar heating was employed in the field to control the downy mildew disease it causes in basil. Covering growth houses of sweet basil already infected with downy mildew with transparent infra-red-impermeable, transparent polyethylene sheets raised the daily maximal temperature during sunny hours by 11-22 °C reaching 40-58 °C (greenhouse effect. Such coverage, applied for a few hours during 1-3 consecutive days, had a detrimental effect on the survival of P. belbahrii: killing the pathogen and/or suppressing disease progress while enhancing growth of the host basil plants.

  13. Low-Cost Control System Built Upon Consumer-Based Electronics For Supervisory Control Of A Gas-Operated Heat Pump

    Energy Technology Data Exchange (ETDEWEB)

    Wetherington Jr, G Randall [ORNL; Vineyard, Edward Allan [ORNL; Mahderekal, Isaac [ORNL; Abu-Heiba, Ahmad [ORNL

    2017-06-01

    A preliminary evaluation of the performance of a consumer-based control system was conducted by the Oak Ridge National Laboratory (ORNL) and Southwest Gas as part of a cooperative research and development agreement (CRADA) authorized by the Department of Energy (DOE) (Mahderekal et al. (2013). The goal of the research was to evaluate the low-cost approach as a solution for implementing a supervisory control system for a residential gas-operated heat pump. The design incorporated two consumer-based micro-controllers; the Arduino Mega-2650 and the BeagleBone (white). Ten five-ton heat pump systems were designed, fabricated, and operationally tested in the Las Vega NV region. A robust data set was produced that allowed detailed assessment of the reliability and the operational perfromance of the newly developed control system. Experiences gained from the test provided important points of improvement for subsequent evolution of the heat pump technology.

  14. Low order modelling and closed-loop thermal control of a ventilated plate subject to a heat source disturbance

    Science.gov (United States)

    Videcoq, E.; Girault, M.; Petit, D.

    2012-11-01

    A multi-input multi-output (MIMO) thermal control problem in real-time is investigated. An aluminum slab is heated on one side by a radiative heat source and cooled on the other side by a fan panel. Starting from a nominal steady state configuration of heat source power and ventilation level, the objective is to control temperature at 4 chosen locations on the rear side when the thermal system is subject to a perturbation: the heat source power. The 4 actuators are the ventilation levels of 4 fans. The hypothesis of small inputs and temperature responses deviations is made, resulting in the assumption of a linear control problem. The originality of this work is twofold: (i) instead of a (large-sized) classical heat transfer model built from spatial discretization of local partial differential equations governing physics over the system domain, a low order model is identified from experimental data using the Modal Identification Method, (ii) this low order model is used to perform state feedback control in real time through a Linear Quadratic Gaussian (LQG) compensator.

  15. Smooth and robust solutions for Dirichlet boundary control of fluid-solid conjugate heat transfer problems

    KAUST Repository

    Yan, Yan

    2015-01-01

    We study a new optimization scheme that generates smooth and robust solutions for Dirichlet velocity boundary control (DVBC) of conjugate heat transfer (CHT) processes. The solutions to the DVBC of the incompressible Navier-Stokes equations are typically nonsmooth, due to the regularity degradation of the boundary stress in the adjoint Navier-Stokes equations. This nonsmoothness is inherited by the solutions to the DVBC of CHT processes, since the CHT process couples the Navier-Stokes equations of fluid motion with the convection-diffusion equations of fluid-solid thermal interaction. Our objective in the CHT boundary control problem is to select optimally the fluid inflow profile that minimizes an objective function that involves the sum of the mismatch between the temperature distribution in the fluid system and a prescribed temperature profile and the cost of the control.Our strategy to resolve the nonsmoothness of the boundary control solution is based on two features, namely, the objective function with a regularization term on the gradient of the control profile on both the continuous and the discrete levels, and the optimization scheme with either explicit or implicit smoothing effects, such as the smoothed Steepest Descent and the Limited-memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS) methods. Our strategy to achieve the robustness of the solution process is based on combining the smoothed optimization scheme with the numerical continuation technique on the regularization parameters in the objective function. In the section of numerical studies, we present two suites of experiments. In the first one, we demonstrate the feasibility and effectiveness of our numerical schemes in recovering the boundary control profile of the standard case of a Poiseuille flow. In the second one, we illustrate the robustness of our optimization schemes via solving more challenging DVBC problems for both the channel flow and the flow past a square cylinder, which use initial

  16. Risk factors for deaths during the 2009 heat wave in Adelaide, Australia: a matched case-control study

    Science.gov (United States)

    Zhang, Ying; Nitschke, Monika; Krackowizer, Antoinette; Dear, Keith; Pisaniello, Dino; Weinstein, Philip; Tucker, Graeme; Shakib, Sepehr; Bi, Peng

    2017-01-01

    The extreme heat wave in Australia in 2009 resulted in significantly increased number of daily deaths. The circumstances that lead to deaths during extreme heat have not been explored before in Australia. This study aims to identify the individual and community risk factors for deaths during this extreme heat wave in Adelaide. A matched case-control study was conducted. Cases were those who died in the Adelaide metropolitan area during the heat wave period. For each case, two community controls were randomly selected, matched by age and gender. Face-to-face or telephone interviews were conducted to collect data of demographic information, living environment, social support, health status and behavioural changes during the heat wave. Descriptive analysis, as well as simple and multiple conditional logistic regressions were performed. In total, 82 deaths and 164 matched community controls were included in the analysis, with a median age of 77.5 (range 26.6-100.7). The multiple logistic regression model indicated that, compared with controls, the risk of death during the heat wave was significantly increased for people living alone (AOR = 42.31, 95 % CI 2.3, 792.8) or having existing chronic heart disease (AOR = 22.4, 95 % CI 1.7, 303.0). In addition, having air conditioning in bedrooms (AOR = 0.004, 95 % CI 0.00006, 0.28) and participating in social activities more than once a week (AOR = 0.011, 95 % CI 0.0004, 0.29) indicated significant protective effects. We have identified factors that could significantly impact on the likelihood of deaths during heat waves. Our findings could assist in the development of future intervention programs and policies to reduce mortality associated with a warmer climate.

  17. Bypass valve and coolant flow controls for optimum temperatures in waste heat recovery systems

    Science.gov (United States)

    Meisner, Gregory P

    2013-10-08

    Implementing an optimized waste heat recovery system includes calculating a temperature and a rate of change in temperature of a heat exchanger of a waste heat recovery system, and predicting a temperature and a rate of change in temperature of a material flowing through a channel of the waste heat recovery system. Upon determining the rate of change in the temperature of the material is predicted to be higher than the rate of change in the temperature of the heat exchanger, the optimized waste heat recovery system calculates a valve position and timing for the channel that is configurable for achieving a rate of material flow that is determined to produce and maintain a defined threshold temperature of the heat exchanger, and actuates the valve according to the calculated valve position and calculated timing.

  18. Design and test of a self-controlled heat pipe radiator.

    Science.gov (United States)

    Swerdling, B.; Hembach, R.

    1973-01-01

    A 15,000-W spacecraft waste heat rejection system utilizing heat pipe radiator panels has been investigated. Of the several concepts initially identified, a series system was selected for more in-depth analysis. As a demonstration of system feasibility, a nominal 500-W radiator panel has been designed, built, and bench tested. The panel, which is a module of the 15,000-W system, consists of a variable conductance heat pipe (VCHP) header, and six isothermalizer heat pipes attached to a radiator. The thermal load to the VCHP is supplied by a Freon 21 liquid loop via an integral heat exchanger. This paper describes the results of the system studies and the radiator design. Also presented are test data on the VCHP, heat exchanger and isothermalizer heat pipes.

  19. Physics responsible for heating efficiency and self-controlled temperature rise of magnetic nanoparticles in magnetic hyperthermia therapy.

    Science.gov (United States)

    Shaterabadi, Zhila; Nabiyouni, Gholamreza; Soleymani, Meysam

    2017-10-06

    Magnetic nanoparticles as heat-generating nanosources in hyperthermia treatment are still faced with many drawbacks for achieving sufficient clinical potential. In this context, increase in heating ability of magnetic nanoparticles in a biologically safe alternating magnetic field and also approach to a precise control on temperature rise are two challenging subjects so that a significant part of researchers' efforts has been devoted to them. Since a deep understanding of Physics concepts of heat generation by magnetic nanoparticles is essential to develop hyperthermia as a cancer treatment with non-adverse side effects, this review focuses on different mechanisms responsible for heat dissipation in a radio frequency magnetic field. Moreover, particular attention is given to ferrite-based nanoparticles because of their suitability in radio frequency magnetic fields. Also, the key role of Curie temperature in suppressing undesired temperature rise is highlighted. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Volumetric Properties of the Mixture Tribromomethane CHBr3 + C6H12 Cyclohexane (VMSD1112, LB4219_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Tribromomethane CHBr3 + C6H12 Cyclohexane (VMSD1112, LB4219_V)' providing data by calculation of mass density in the single-phase region(s) from low-pressure dilatometric measurements of the molar excess volume at variable mole fraction and constant temperature.

  1. Volumetric Properties of the Mixture Benzene C6H6 + C6H12 Cyclohexane (VMSD1221, LB3969_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Benzene C6H6 + C6H12 Cyclohexane (VMSD1221, LB3969_V)' providing data from direct dilatometric measurement of molar excess volume at variable mole fraction and constant pressure and temperature, in the single-phase region(s).

  2. Volumetric Properties of the Mixture Cyclohexene C6H10 + C6H12 Cyclohexane (VMSD1112, LB4460_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexene C6H10 + C6H12 Cyclohexane (VMSD1112, LB4460_V)' providing data by calculation of mass density in the single-phase region(s) from low-pressure dilatometric measurements of the molar excess volume at variable mole fraction and constant temperature.

  3. Heat Health Messages: A Randomized Controlled Trial of a Preventative Messages Tool in the Older Population of South Australia

    Directory of Open Access Journals (Sweden)

    Monika Nitschke

    2017-08-01

    Full Text Available This study explores the efficacy of providing targeted information to older individuals to prevent adverse health outcomes during extreme heat. Participants ≥65 years of age (n = 637 were recruited from previous population-based studies and randomized into intervention and control groups. The intervention group received evidence-based information leaflets and summarised “Beat the Heat” tips. Post summer 2013–2014, participants responded to questions about their behaviours and their health experiences. Chi square analysis and risk ratios (RR were used to determine the difference in effects. Responses were received from 216 intervention subjects and 218 controls. Behaviour modification during extreme heat was similar in both groups except for significant increases in the use of cooling systems and the use of a wet cloth to cool the skin in the intervention group. Both actions were recommended in the information package. More people in the intervention group also claimed to have had adequate heat health information. After adjusting for confounders, the RR for self-reported heat stress experienced during summer 2014 indicated a 63% (RR 0.37; 95% CI: 0.22–0.63 reduction in the intervention group compared to the control group. Access to intensive prevention information may have contributed to this positive outcome, indicating the potential usefulness of targeted heat-health information for seniors.

  4. Optimum radiator control to reach a low district heating return temperature; Optimal radiatorreglering foer att naa laag fjaerrvaermereturtemperatur

    Energy Technology Data Exchange (ETDEWEB)

    Ljunggren, Patrick; Wollerstrand, Janusz [Lund Univ. (Sweden). Energy Sciences

    2005-12-15

    system that has been analysed give approximately 12 deg C improved cooling of primary water. Flow optimization of a low temperature adjusted system can give another 3-4 deg C improved cooling. It is interesting to see that even a perfectly designed system can be flow optimized; with almost 2 deg C improved cooling as result. If the radiator heat exchanger in the substation is 100 per cent oversized, the primary return temperature will be reduced up to 1,5 deg C. A majority, 61 per cent, of the amount of district heating sold in Sweden is covered by some kind of flow accounting. If a low and a high temperature space heating system is compared a definite difference can be noticed, up to 18,000 SEK lower cost for delivered heat for a building with 100 apartments with a low temperature system. One can state that, in large buildings, there is economic space for investments with purpose to improve the cooling. Even the domestic hot water circuit in the substation can be modified for best possible cooling. One of the possible solutions is demand side control of the domestic hot water temperature and implementation of flow limitation in the domestic hot water heater. It can be shown that the heater's heat exchanger can be overloaded with at least 20 per cent, without a decrease in hot water temperature below comfortable level (45 deg C), and at the same time improve the cooling of primary water.

  5. One Low-cost Quartz Lamp Radiation Aerodynamic Heating Simulation Experiment System with Control Law Flexible Adjustment Feature

    Directory of Open Access Journals (Sweden)

    Wang Decheng

    2015-01-01

    Full Text Available The quartz lamp radiation aerodynamic heating simulation experiment system plays an important role on the structure strength heat experiment. In order to reduce its price and enhance flexibility on control law design of experiment system, a design method for low-cost quartz lamp radiation aerodynamic heating simulation experiment system with control law flexible adjustment feature is proposed. The hardware part is constructed by taking Digital Signal Processor (DSP as an implementing agency controller. The feedback temperature after processed is computed by DSP. But the experiment process control value is computed by computer. The feedback temperature and experiment process control value data are transferred by serial communication model between DSP and computer. The experiment process relation data is saved by computer with EXCEL file, including the given target spectrum, the feedback temperature and the control value. The results of experiments on system identification, PID spectrum tracking, different zone control and the open loop control show the effectiveness of the proposed method.

  6. Method and apparatus for active control of combustion rate through modulation of heat transfer from the combustion chamber wall

    Science.gov (United States)

    Roberts, Jr., Charles E.; Chadwell, Christopher J.

    2004-09-21

    The flame propagation rate resulting from a combustion event in the combustion chamber of an internal combustion engine is controlled by modulation of the heat transfer from the combustion flame to the combustion chamber walls. In one embodiment, heat transfer from the combustion flame to the combustion chamber walls is mechanically modulated by a movable member that is inserted into, or withdrawn from, the combustion chamber thereby changing the shape of the combustion chamber and the combustion chamber wall surface area. In another embodiment, heat transfer from the combustion flame to the combustion chamber walls is modulated by cooling the surface of a portion of the combustion chamber wall that is in close proximity to the area of the combustion chamber where flame speed control is desired.

  7. Volumetric polymerization shrinkage of contemporary composite resins

    Directory of Open Access Journals (Sweden)

    Halim Nagem Filho

    2007-10-01

    Full Text Available The polymerization shrinkage of composite resins may affect negatively the clinical outcome of the restoration. Extensive research has been carried out to develop new formulations of composite resins in order to provide good handling characteristics and some dimensional stability during polymerization. The purpose of this study was to analyze, in vitro, the magnitude of the volumetric polymerization shrinkage of 7 contemporary composite resins (Definite, Suprafill, SureFil, Filtek Z250, Fill Magic, Alert, and Solitaire to determine whether there are differences among these materials. The tests were conducted with precision of 0.1 mg. The volumetric shrinkage was measured by hydrostatic weighing before and after polymerization and calculated by known mathematical equations. One-way ANOVA (a or = 0.05 was used to determine statistically significant differences in volumetric shrinkage among the tested composite resins. Suprafill (1.87±0.01 and Definite (1.89±0.01 shrank significantly less than the other composite resins. SureFil (2.01±0.06, Filtek Z250 (1.99±0.03, and Fill Magic (2.02±0.02 presented intermediate levels of polymerization shrinkage. Alert and Solitaire presented the highest degree of polymerization shrinkage. Knowing the polymerization shrinkage rates of the commercially available composite resins, the dentist would be able to choose between using composite resins with lower polymerization shrinkage rates or adopting technical or operational procedures to minimize the adverse effects deriving from resin contraction during light-activation.

  8. Efficient volumetric estimation from plenoptic data

    Science.gov (United States)

    Anglin, Paul; Reeves, Stanley J.; Thurow, Brian S.

    2013-03-01

    The commercial release of the Lytro camera, and greater availability of plenoptic imaging systems in general, have given the image processing community cost-effective tools for light-field imaging. While this data is most commonly used to generate planar images at arbitrary focal depths, reconstruction of volumetric fields is also possible. Similarly, deconvolution is a technique that is conventionally used in planar image reconstruction, or deblurring, algorithms. However, when leveraged with the ability of a light-field camera to quickly reproduce multiple focal planes within an imaged volume, deconvolution offers a computationally efficient method of volumetric reconstruction. Related research has shown than light-field imaging systems in conjunction with tomographic reconstruction techniques are also capable of estimating the imaged volume and have been successfully applied to particle image velocimetry (PIV). However, while tomographic volumetric estimation through algorithms such as multiplicative algebraic reconstruction techniques (MART) have proven to be highly accurate, they are computationally intensive. In this paper, the reconstruction problem is shown to be solvable by deconvolution. Deconvolution offers significant improvement in computational efficiency through the use of fast Fourier transforms (FFTs) when compared to other tomographic methods. This work describes a deconvolution algorithm designed to reconstruct a 3-D particle field from simulated plenoptic data. A 3-D extension of existing 2-D FFT-based refocusing techniques is presented to further improve efficiency when computing object focal stacks and system point spread functions (PSF). Reconstruction artifacts are identified; their underlying source and methods of mitigation are explored where possible, and reconstructions of simulated particle fields are provided.

  9. Control of Advanced Reactor-Coupled Heat Exchanger System: Incorporation of Reactor Dynamics in System Response to Load Disturbances

    Directory of Open Access Journals (Sweden)

    Isaac Skavdahl

    2016-12-01

    Full Text Available Alternative control schemes for an Advanced High Temperature Reactor system consisting of a reactor, an intermediate heat exchanger, and a secondary heat exchanger (SHX are presented in this paper. One scheme is designed to control the cold outlet temperature of the SHX (Tco and the hot outlet temperature of the intermediate heat exchanger (Tho2 by manipulating the hot-side flow rates of the heat exchangers (Fh/Fh2 responding to the flow rate and temperature disturbances. The flow rate disturbances typically require a larger manipulation of the flow rates than temperature disturbances. An alternate strategy examines the control of the cold outlet temperature of the SHX (Tco only, since this temperature provides the driving force for energy production in the power conversion unit or the process application. The control can be achieved by three options: (1 flow rate manipulation; (2 reactor power manipulation; or (3 a combination of the two. The first option has a quicker response but requires a large flow rate change. The second option is the slowest but does not involve any change in the flow rates of streams. The third option appears preferable as it has an intermediate response time and requires only a minimal flow rate change.

  10. Efficacy of heat-inactivated hepatitis B vaccine in haemodialysis patients and staff. Double-blind placebo-controlled trial

    NARCIS (Netherlands)

    Desmyter, J.; Colaert, J.; de Groote, G.; Reynders, M.; Reerink-Brongers, E. E.; Lelie, P. N.; Dees, P. J.; Reesink, H. W.

    1983-01-01

    The efficacy of a heat-inactivated hepatitis B vaccine, 3 micrograms of surface antigen (HBsAg), given at 0, 1, 2, and 5 months, was evaluated in 401 haemodialysis patients in 18 centres by a placebo-controlled, double-blind, randomised trial. The attack-rate of hepatitis B virus (HBV) infections in

  11. Efficacy of a heat inactivated hepatitis B vaccine in male homosexuals: outcome of a placebo controlled double blind trial

    NARCIS (Netherlands)

    Coutinho, R. A.; Lelie, N.; Albrecht-van Lent, P.; Reerink-Brongers, E. E.; Stoutjesdijk, L.; Dees, P.; Nivard, J.; Huisman, J.; Reesink, H. W.

    1983-01-01

    The efficacy of a heat inactivated hepatitis B virus vaccine, containing 3 micrograms hepatitis B surface antigen (HBsAg), was studied in a high risk group of 800 susceptible homosexual men by a randomised placebo controlled double blind trial. At the trial end point (21.5 months), 17 hepatitis B

  12. In situ soil temperature and heat flux measurements during controlled surface burns at a southern Colorado forest site

    Science.gov (United States)

    W. J. Massman; J. M. Frank; W. D. Shepperd; M. J. Platten

    2003-01-01

    This study presents in situ soil temperature measurements at 5-6 depths and heat flux measurements at 2-5 depths obtained during the fall/winter of 2001/ 2002 at seven controlled (surface) fires within a ponderosa pine forest site at the Manitou Experimental Forest in central Colorado. Six of these burns included three different (low, medium, and high) fuel loadings...

  13. A study of heat-transfer processes in a countercurrent cyclone heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    M.G. Abuov; P.A. Kovgan [TOO Gornoe Byuro (Mining Bureau), Alma Aty (Kazakhstan)

    2009-07-01

    Heat-transfer processes in a countercurrent cyclone heat exchanger are investigated on a pilot installation. Volumetric coefficients of heat transfer from gases to a flow of solid particles are determined during operation with tangentially swirled flow of gas suspension, separation of solid particles on the heat-exchanger walls, and deceleration of flue gas flows as they collide with the charge mixture fed to the apparatus.

  14. Differential control of Salmonella heat shock operons by structured mRNAs.

    Science.gov (United States)

    Cimdins, Annika; Roßmanith, Johanna; Langklotz, Sina; Bandow, Julia E; Narberhaus, Franz

    2013-08-01

    DnaK-DnaJ-GrpE and GroES-GroEL are the major chaperone machineries in bacteria. In many species, dnaKJ and groESL are encoded in bicistronic operons. Quantitative proteomics revealed that DnaK and GroEL amounts in Salmonella dominate over DnaJ and GroES respectively. An imperfect transcriptional terminator in the intergenic region of dnaKJ is known to result in higher transcript levels of the first gene. Here, we examined the groESL operon and asked how the second gene in a heat shock operon can be preferentially expressed and found that an RNA structure in the 5'untranslated region of groES is responsible. The secondary structure masks the Shine-Dalgarno (SD) sequence and AUG start codon and thereby modulates translation of groES mRNA. Reporter gene assays combined with structure probing and toeprinting analysis revealed a dynamic temperature-sensitive RNA structure. Following an increase in temperature, only the second of two RNA hairpins melts and partially liberates the SD sequence, thus facilitating translation. Translation of groEL is not temperature-regulated leading to an excess of the chaperonin in the cell at low temperature. Discussion in a broader context shows how structured RNA segments can differentially control expression of temperature-affected operons in various ways. © 2013 John Wiley & Sons Ltd.

  15. Controlling of upconversion nanoparticle luminescence at heating and optical clearing of adipose tissue

    Science.gov (United States)

    Yanina, Irina Yu.; Volkova, Elena K.; Tuchina, Daria K.; Konyukhova, Julia G.; Kochubey, Vyacheslav I.; Tuchin, Valery V.

    2017-07-01

    The luminescence spectra of a polymer film with embedded upconversion nanoparticles (UCNPs) were measured through 0.1-0.3 mm adipose tissue layer at heating in a wide temperature range. Heating and application of optical clearing agents improved intensity of UCNP fluorescence significantly.

  16. Experimental validation of a dynamic waste heat recovery system model for control purposes

    NARCIS (Netherlands)

    Feru, E.; Kupper, F.; Rojer, C.; Seykens, X.L.J.; Scappin, F.; Willems, F.P.T.; Smits, J.; Jager, B. de; Steinbuch, M.

    2013-01-01

    This paper presents the identification and validation of a dynamic Waste Heat Recovery (WHR) system model. Driven by upcoming CO2 emission targets and increasing fuel costs, engine exhaust gas heat utilization has recently attracted much attention to improve fuel efficiency, especially for

  17. Cost Efficient Optimization Based Supervisory Controller for Supermarket Subsystems with Heat Recovery

    DEFF Research Database (Denmark)

    Minko, Tomasz; Wisniewski, Rafal; Bendtsen, Jan Dimon

    2015-01-01

    In this paper, we present a simple modelling approach for a thermal system, which consists of heating, ventilation, air conditioning system (HVAC) and a vapor compression cycle (VCC) system, with one loop heat recovery. In addition a simple model for water tank is presented, in which the reclaimed...

  18. Distribuição volumétrica e diâmetro de gotas de pontas de pulverização de energia hidráulica para controle de corda-de-viola Volumetric distribution and droplet size of hydraulic spraying nozzles for the control of scarlet morningglory

    Directory of Open Access Journals (Sweden)

    M.C Ferreira

    2011-09-01

    Full Text Available As pontas de pulverização são responsáveis pela formação das gotas, e cada ponta apresenta características próprias relacionadas ao espectro de gotas e perfil de deposição, específicas para determinados alvos. Este trabalho teve o objetivo de caracterizar o diâmetro e a uniformidade das gotas e o perfil de distribuição volumétrica das pontas de pulverização AI 110015 e TTI 110015, bem como seu efeito sobre a mortalidade de corda-de-viola, com herbicida pré-emergente, associado ou não a adjuvantes. Avaliou-se o número de plantas emergidas e os pesos secos da parte aérea e radicular das plantas. Os perfis de distribuição volumétrica para a altura de 40 cm foram avaliados em mesa de deposição. A partir dos perfis de distribuição, simulou-se o padrão de deposição ao longo da barra de pulverização. O espectro do diâmetro de gotas foi determinado em analisador de tamanho de partículas por difração de luz laser . O herbicida diuron + hexazinona foi eficiente no controle em préemergência de corda-de-viola, podendo ser utilizado polimetil siloxano organomodificado ou óleo mineral como adjuvantes, associados às pontas de pulverização AI 110015 ou TTI 110015. O uso de adjuvantes proporcionou aumento no diâmetro mediano volumétrico e redução na porcentagem de gotas com diâmetro inferior a 100 µm. O espaçamento sugerido entre os bicos na barra de pulverização foi de 70 cm para o modelo AI 110015 e 80 cm para o modelo TTI 110015.Nozzles are responsible for the formation of drops, with each side presenting its own characteristics related to droplet deposition spectrum and profile specific to certain targets. This study aimed to characterize the diameter and uniformity of the droplets and volumetric distribution profile of nozzles AI 110015 and 110015 TTI, as well as their effect on the mortality of scarlet morningglory, using pre-emergent herbicide, alone or combined with adjuvants. The number of emerging

  19. Experimental analysis of energy performance of a ventilated window for heat recovery under controlled conditions

    DEFF Research Database (Denmark)

    Appelfeld, David; Svendsen, Svend

    2011-01-01

    balance of the ventilated window and clarified the methodology for thermal performance evaluation. Comparison between windows with and without ventilation using the window-room-ventilation heat balance revealed that a ventilated window can potentially contribute to energy savings. In addition......A ventilated window in cold climates can be considered as a passive heat recovery system. This study carried out tests to determine the thermal transmittance of ventilated windows by using the Guarded Hot Box. By testing under defined boundary conditions, the investigation described the heat......, it was found that a significant part of preheating occurred through the window frames, which positively influenced the heat recovery of the window but increased the heat loss. Results also showed that increasing air flow decreased the recovery efficiency until the point when the additional thermal...

  20. Control of Single-room Ventilation with Regenerative Heat Recovery for Indoor Climate and Energy Performance

    DEFF Research Database (Denmark)

    Smith, Kevin Michael; Svendsen, Svend

    2016-01-01

    The Danish government will seek energy-efficiency improvements to meet their targeted aims. Single-room ventilation with heat recovery allows simple installation through the façade and may be broadly deployed in apartments. Danish building regulations require greater than 80% heat recovery in new...... constructions and will soon require 85%. The development of single-room ventilation units may aim for these requirements as a result. The exhaust temperatures in highly efficient heat exchangers may approach outdoor levels. The cold exhaust cannot contain ample moisture, so vapour will condense on the heat...... exchanger. Available literature suggests that uncoated rotary heat exchangers transfer this condensate to the supply air, so the drying capacity of the ventilation system may be severely limited. This could raise indoor relative humidities to unsafe levels, which could promote the growth of dust...

  1. Characterization of dynamic thermal control schemes and heat transfer pathways for incorporating variable emissivity electrochromic materials into a space suit heat rejection system

    Science.gov (United States)

    Massina, Christopher James

    The feasibility of conducting long duration human spaceflight missions is largely dependent on the provision of consumables such as oxygen, water, and food. In addition to meeting crew metabolic needs, water sublimation has long served as the primary heat rejection mechanism in space suits during extravehicular activity (EVA). During a single eight hour EVA, approximately 3.6 kg (8 lbm) of water is lost from the current suit. Reducing the amount of expended water during EVA is a long standing goal of space suit life support systems designers; but to date, no alternate thermal control mechanism has demonstrated the ability to completely eliminate the loss. One proposed concept is to convert the majority of a space suit's surface area into a radiator such that the local environment can be used as a radiative thermal sink for rejecting heat without mass loss. Due to natural variations in both internal (metabolic) loads and external (environmental) sink temperatures, radiative transport must be actively modulated in order to maintain an acceptable thermal balance. Here, variable emissivity electrochromic devices are examined as the primary mechanism for enabling variable heat rejection. This dissertation focuses on theoretical and empirical evaluations performed to determine the feasibility of using a full suit, variable emissivity radiator architecture for space suit thermal control. Operational envelopes are described that show where a given environment and/or metabolic load combination may or may not be supported by the evaluated thermal architecture. Key integration considerations and guidelines include determining allowable thermal environments, defining skin-to-radiator heat transfer properties, and evaluating required electrochromic performance properties. Analysis also considered the impacts of dynamic environmental changes and the architecture's extensibility to EVA on the Martian surface. At the conclusion of this work, the full suit, variable emissivity

  2. Heat pumps in combined heat and power systems

    DEFF Research Database (Denmark)

    Ommen, Torben Schmidt; Markussen, Wiebke Brix; Elmegaard, Brian

    2014-01-01

    Heat pumps have previously been proposed as a way to integrate higher amounts of renewable energy in DH (district heating) networks by integrating, e.g., wind power. The paper identifies and compares five generic configurations of heat pumps in DH systems. The operational performance...... of the considered cases. When considering a case where the heat pump is located at a CHP (combined heat and power) plant, a configuration that increases the DH return temperature proposes the lowest operation cost, as low as 12 EUR MWh-1 for a 90 °C e 40 °C DH network. Considering the volumetric heating capacity......, a third configuration is superior in all cases. Finally, the three most promising heat pump configurations are integrated in a modified PQ-diagram of the CHP plant. Each show individual advantages, and for two, also disadvantages in order to achieve flexible operation....

  3. HIFU treatment time reduction through heating approach optimisation.

    Science.gov (United States)

    Coon, Joshua; Todd, Nick; Roemer, Robert

    2012-01-01

    This study evaluated the HIFU treatment time reductions attainable for several scan paths when optimising the heating approach used (single, discrete pulses versus volumetric scanning) and the paths' focal zone heating locations'; number (N(FZL)), spacings, sequencing order, number of heating cycles (N(CYCLES)), and heating times. Also evaluated were the effects of focal zone size, increased tissue absorptivity due to heating, and optimisation technique. Treatments of homogeneous constant property tumours were simulated for several simple generic tumour shapes and sizes. The concentrated heating approach (which delivered the desired thermal dose to each location in one discrete heating pulse (N(CYCLES) = 1)) was compared to the fractionated heating approach (which dosed the tumour using multiple, shorter pulses repeatedly scanned around the heating path (i.e. 'volumetric scanning' with N(CYCLES) > 1)). Treatment times were minimised using both simultaneous, collective pulse optimisation (which used full a priori knowledge of the interacting effects of all pulses) and sequential, single pulse optimisation (which used only the information from previous pulses and cooling of the current pulse). Optimised concentrated heating always had shorter treatment times than optimised fractionated heating, and concentrated heating resulted in less normal tissue heating. When large, rapid tissue absorptivity changes were present (doubled or quadrupled immediately after heating) the optimal ordering of the scan path's sequence of focal zone locations changed. Concentrated heating yields significant treatment time reductions and less normal tissue heating when compared to all fractionated scanning approaches, e.g. volumetric scanning.

  4. The Optimized Operation of Gas Turbine Combined Heat and Power Units Oriented for the Grid-Connected Control

    Science.gov (United States)

    Xia, Shu; Ge, Xiaolin

    2016-04-01

    In this study, according to various grid-connected demands, the optimization scheduling models of Combined Heat and Power (CHP) units are established with three scheduling modes, which are tracking the total generation scheduling mode, tracking steady output scheduling mode and tracking peaking curve scheduling mode. In order to reduce the solution difficulty, based on the principles of modern algebraic integers, linearizing techniques are developed to handle complex nonlinear constrains of the variable conditions, and the optimized operation problem of CHP units is converted into a mixed-integer linear programming problem. Finally, with specific examples, the 96 points day ahead, heat and power supply plans of the systems are optimized. The results show that, the proposed models and methods can develop appropriate coordination heat and power optimization programs according to different grid-connected control.

  5. Controlled Cavitation for Scale-Free Heating, Gum Hydration and Emulsification in Food and Consumer Products

    Science.gov (United States)

    Mancosky, Douglas G.; Milly, Paul

    Cavitation is defined as the sudden formation and collapse of bubbles in liquid by means of a mechanical force. As bubbles rapidly form and collapse, pressurized shock waves, localized heating events and tremendous shearing forces occur. As microscopic cavitation bubbles are produced and collapse, shockwaves are given off into the liquid, which can result in heating and/or mixing, similar to ultrasound. These shockwaves can provide breakthrough benefits for the heating of liquids without scale buildup and/or the mixing of liquids with other liquids, gases or solids at the microscopic level to increase the efficiency of the reaction.

  6. Loop Heat Pipe with Thermal Control Valve for Passive Variable Thermal Link Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Future Lunar Landers and Rovers will require variable thermal links that can reject heat during daytime, and passively shut-off during lunar night. During the long...

  7. Natural Heat-Sinking Control Method for High-Speed Actuation of the SMA

    Directory of Open Access Journals (Sweden)

    Tamio Arai

    2008-11-01

    Full Text Available This paper describes two methodologies for increasing the actuation speed of the shape memory alloy (SMA actuator in ambient environment. The first method involves the implementation of a simple, light-weight heat sink, which consists only of a combination of an outer metal tube with the silicone grease, but able to cool the heated alloy effectively. The second method describes a high current pulse actuation that actuates the alloy fastly using pulses in the milliseconds order. We hypothesize that a fast actuation of the SMA results in small increase in temperature, due to energy transformation from heat energy to the kinetic energy in the SMA. This new heating method revolutionizes the actuation of the alloy for a significantly faster response.

  8. Loop Heat Pipe with Thermal Control Valve for Passive Variable Thermal Link Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Loop heat pipes (LHPs) can provide variable thermal conductance needed to maintain electronics and batteries on Lunar/Martian rovers/landers within desired...

  9. Utilization of a heat pump in pig breeding for energy saving and climate and ammonia control

    Energy Technology Data Exchange (ETDEWEB)

    Riva, Giovanni; Pedretti, Ester Foppa [Ancona Univ., Ancona (Italy); Fabbri, Claudio [Centro Ricerche Produzioni Animali, Reggio Emilia (Italy)

    2000-12-01

    The performance of three heating systems was analysed in closed-cycle pig farm (farrowing and weaning section). Three adjoining rooms were heated using one of the following systems: a reversible air to air heat pump (HP) for both heating and cooling; a standard liquid petroleum gas (LPG) boiler for heating coupled with mechanical ventilation for summer cooling; and natural ventilation with emergency convective heating. Their energy consumption and influence on production parameters were compared. Fifteen groups of sow and their litters were housed in succession in each room from the end of pregnancy through weaning (5 cycles). Temperature and humidity and production parameters (i.e. feed conversion index) were measured for each cycle and room. In the case of HP, the ammonia emissions produced in, and extracted from, the breeding room were also determined. The HP consistently maintained both temperature and humidity around optimal values (average 26.2degC and 64.2% relative humidity) and allowed primary energy savings of 11% compared with the LPG heater. The piglets weaned in the HP room showed better growth performance. Finally, the air processed by the HP contained less than half the ammonia concentrations recorded in the naturally ventilated room. (Author)

  10. A Technique for Volumetric CSG Based on Morphology

    DEFF Research Database (Denmark)

    Bærentzen, Jakob Andreas; Christensen, Niels Jørgen

    2001-01-01

    In this paper, a new technique for volumetric CSG is presented. The technique requires the input volumes to correspond to solids which fulfill a voxelization suitability criterion. Assume the CSG operation is union. The volumetric union of two such volumes is defined in terms of the voxelization...

  11. Radio frequency heating: a potential method for post-harvest pest control in nuts and dry products

    Science.gov (United States)

    Wang, Shao-jin; Tang, Ju-ming

    2004-01-01

    The multi-billion dollar US tree nut industries rely heavily on methyl bromide fumigation for postharvest insect control and are facing a major challenge with the mandated cessation by 2005 of its use for most applications. There is an urgent need to develop effective and economically viable alternative treatments to replace current phytosanitary and quarantine practices in order to maintain the competitiveness of US agriculture in domestic and international markets. With the reliable heating block system, the thermal death kinetics for fifth-instar codling moth, Indianmeal moth, and navel orangeworm were determined at a heating rate of 18 °C/min. A practical process protocol was developed to control the most heat resistant insect pest, fifth-instar navel orangeworm, in in-shell walnuts using a 27 MHz pilot scale radio frequency (RF) system. RF heating to 55 °C and holding in hot air for at least 5 min resulted in 100% mortality of the fifth-instar navel orangeworm. Rancidity, sensory qualities and shell characteristics were not affected by the treatments. If this method can be economically integrated into the handling process, it should have excellent potential as a disinfestation method for in-shell walnuts. PMID:15362185

  12. Hardening by cooling rate control and post-firing heat treatment in Pd-Ag-Sn alloy for bonding porcelain.

    Science.gov (United States)

    Yu, Young-Jun; Seol, Hyo-Joung; Cho, Mi-Hyang; Kim, Hyung-Il; Kwon, Yong Hoon

    2016-01-01

    The aim of this study was to determine the hardening effect by controlling the cooling rate during the porcelain firing process and performing an additional post-firing heat treatment in a Pd-Ag-Sn alloy. The most effective cooling rate for alloy hardening was determined by cooling the specimens at various cooling rates after oxidation treatment. A subsequent porcelain firing simulation followed by cooling at the selected cooling rate was performed. A post-firing heat treatment was then done at 600°C in a porcelain furnace. The hardening mechanism was characterized by a hardness test, X-ray diffraction, field emission scanning electron microscopy and energy dispersive X-ray spectroscopy. Alloy softening occurred during the porcelain firing process followed by cooling at a controlled cooling rate. A post-firing heat treatment allowed apparent precipitation hardening. It is advisable to perform a postfiring heat treatment at 600°C in a porcelain furnace by annealing metal substructure after porcelain fusing.

  13. AUTOMATED SYSTEM OF OPERATIONAL CONTROL HEATING AND AIR CONDITIONING OF BUILDINGS

    Directory of Open Access Journals (Sweden)

    PETRENKO A. O.

    2016-08-01

    microclimate in the buildings of different functions when you change the factors that affect it. This will create a system of automatic control of technological space heating and cooling processes, which will adapt to the changes in the factors that affect the indoor climate of buildings for different purposes.

  14. Impact of Turbocharger Non-Adiabatic Operation on Engine Volumetric Efficiency and Turbo Lag

    Directory of Open Access Journals (Sweden)

    S. Shaaban

    2012-01-01

    Full Text Available Turbocharger performance significantly affects the thermodynamic properties of the working fluid at engine boundaries and hence engine performance. Heat transfer takes place under all circumstances during turbocharger operation. This heat transfer affects the power produced by the turbine, the power consumed by the compressor, and the engine volumetric efficiency. Therefore, non-adiabatic turbocharger performance can restrict the engine charging process and hence engine performance. The present research work investigates the effect of turbocharger non-adiabatic performance on the engine charging process and turbo lag. Two passenger car turbochargers are experimentally and theoretically investigated. The effect of turbine casing insulation is also explored. The present investigation shows that thermal energy is transferred to the compressor under all circumstances. At high rotational speeds, thermal energy is first transferred to the compressor and latter from the compressor to the ambient. Therefore, the compressor appears to be “adiabatic” at high rotational speeds despite the complex heat transfer processes inside the compressor. A tangible effect of turbocharger non-adiabatic performance on the charging process is identified at turbocharger part load operation. The turbine power is the most affected operating parameter, followed by the engine volumetric efficiency. Insulating the turbine is recommended for reducing the turbine size and the turbo lag.

  15. The influence of high heat input and inclusions control for rare earth on welding in low alloy high strength steel

    Science.gov (United States)

    Chu, Rensheng; Mu, Shukun; Liu, Jingang; Li, Zhanjun

    2017-09-01

    In the current paper, it is analyzed for the influence of high heat input and inclusions control for rare earth on welding in low alloy high strength steel. It is observed for the structure for different heat input of the coarse-grained area. It is finest for the coarse grain with the high heat input of 200 kJ / cm and the coarse grain area with 400 kJ / cm is the largest. The performance with the heat input of 200 kJ / cm for -20 °C V-shaped notch oscillatory power is better than the heat input of 400 kJ / cm. The grain structure is the ferrite and bainite for different holding time. The grain structure for 5s holding time has a grain size of 82.9 μm with heat input of 200 kJ/cm and grain size of 97.9 μm for 10s holding time. For the inclusions for HSLA steel with adding rare earth, they are Al2O3-CaS inclusions in the Al2O3-CaS-CaO ternary phase diagram. At the same time, it can not be found for low melting calcium aluminate inclusions compared to the inclusions for the HSLA steel without rare earth. Most of the size for the inclusions is between 1 ~ 10μm. The overall grain structure is smaller and the welding performance is more excellent for adding rare earth.

  16. Remote control systems for space heating. Product overview 2010 and recommendations - Final report; Fernsteuerungen fuer Raumheizungen. Produktuebersicht 2010 und Empfehlungen - Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Geilinger, E.; Bush, E. [Bush Energie GmbH, Felsberg (Switzerland); Venzin, T. [Hochschule fuer Technik und Wirtschaft (HTW) Chur, Chur (Switzerland); Nipkow, J. [Arena, Zuerich (Switzerland)

    2010-09-15

    Saving space heating energy by remote control: A remote-controlled space heating system allows a person to lower the room temperature in homes that go unoccupied for periods of time to the lowest temperature that's safe to keep the pipes from freezing while they're away. Comfort is guaranteed because the desired room temperature or mode can be activated in time before the guests arrive, via text message, phone or the internet. As most people simply leave unoccupied homes heated, the remote-controlled system saves up to 70% of heating energy when used actively. Market overview and product features: This report presents remote control devices that are currently available on the market. Their advantages and disadvantages are discussed as well as their technical features and function. Most of them are universal remote controls that have various uses, including temperature control. The report also discusses requirements that not all the examined products meet. Some lack an emergency power supply, the possibility for manual control or the ability to check the current temperature of the home from a remote location. Better planning for remote control: The critical issue proved not to be the remote control device itself, but the heating systems. Unfortunately, they often don't provide an option to be extended by remote control. We therefore call on the manufacturers to equip all new heating systems with options for remote control. It would also be helpful and desirable to provide information on the internet or in the technical documentation on how to connect a remote control device and which products are suitable - both for existing and new heating systems. If the system cannot be retrofitted, it should be described whether and how a central remote control with room thermostat can be installed. Improving communication: In this study, remote control and heating suppliers were interviewed as well as planners, installers and users of remote-controlled heating

  17. UV-Heat Treatments for the Control of Foodborne Microbial Pathogens in Chicken Broth

    Directory of Open Access Journals (Sweden)

    M. Gouma

    2015-01-01

    Full Text Available This investigation established the process criteria for using UV-C light and mild heat (UV-H treatment to inactivate 5-Log10 cycles (performance criterion of common foodborne pathogen populations, Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus, when inoculated in chicken broth. To define the target microorganism and the proper UV-H treatment conditions (including UV dose, treatment time, and temperature that would achieve the stated performance criterion, mathematical equations based on Geeraerd’s model were developed for each microorganism. For the sake of comparison, inactivation equations for heat treatments were also performed on the same chicken broth and for the same microorganisms. L. monocytogenes was the most UV-H resistant microorganism at all temperatures, requiring a UV dose between 6.10 J/mL (5.6 min and 2.26 J/mL (2.09 min to achieve 5-Log10 reductions. In comparison with UV treatments at room temperatures, the combination of UV and mild heat allowed both the UV dose and treatment time to be reduced by 30% and 63% at 55°C and 60°C, respectively. Compared to heat treatments, the UV-H process reduced the heating time for 5-Log10 reductions of all the investigated microorganisms in chicken broth from 20-fold to 2-fold when the operating temperature varied from 53 to 60°C.

  18. Area and volumetric density estimation in processed full-field digital mammograms for risk assessment of breast cancer.

    Directory of Open Access Journals (Sweden)

    Abbas Cheddad

    Full Text Available INTRODUCTION: Mammographic density, the white radiolucent part of a mammogram, is a marker of breast cancer risk and mammographic sensitivity. There are several means of measuring mammographic density, among which are area-based and volumetric-based approaches. Current volumetric methods use only unprocessed, raw mammograms, which is a problematic restriction since such raw mammograms are normally not stored. We describe fully automated methods for measuring both area and volumetric mammographic density from processed images. METHODS: The data set used in this study comprises raw and processed images of the same view from 1462 women. We developed two algorithms for processed images, an automated area-based approach (CASAM-Area and a volumetric-based approach (CASAM-Vol. The latter method was based on training a random forest prediction model with image statistical features as predictors, against a volumetric measure, Volpara, for corresponding raw images. We contrast the three methods, CASAM-Area, CASAM-Vol and Volpara directly and in terms of association with breast cancer risk and a known genetic variant for mammographic density and breast cancer, rs10995190 in the gene ZNF365. Associations with breast cancer risk were evaluated using images from 47 breast cancer cases and 1011 control subjects. The genetic association analysis was based on 1011 control subjects. RESULTS: All three measures of mammographic density were associated with breast cancer risk and rs10995190 (p0.10 for risk, p>0.03 for rs10995190. CONCLUSIONS: Our results show that it is possible to obtain reliable automated measures of volumetric and area mammographic density from processed digital images. Area and volumetric measures of density on processed digital images performed similar in terms of risk and genetic association.

  19. Modelling and control of heat-integrated distillation columns: An industrial case study

    DEFF Research Database (Denmark)

    Mauricio Iglesias, Miguel; Johansen, Kristoffer; Jørgensen, Sten Bay

    of energy wasted increases, questioning the economics of implementation of heat integration. Modelling is the foremost tool in assessment of chemical process dynamics. In the case of distillation, an extensive literature deals with classic distillation columns whereas much less has been investigated...... in the industrial case is composed of two distillation columns in series (operated at 3.5 and 1.5 bar) for recovery of ethanol from a pseudo-binary mixture (heavy key water). Heat recovery is carried out both backward (from the two bottoms flow to the feed) and forward (from the first condensate to the second......Energy requirements of distillation processes account for a large percentage of the total energy consumption of the chemical industry. Hence, strategies for heat recovery have been extensively implemented in industrial processes during the last decades. However, operation (including start...

  20. Involvement of DNA methylation in the control of cell growth during heat stress in tobacco BY-2 cells.

    Science.gov (United States)

    Centomani, Isabella; Sgobba, Alessandra; D'Addabbo, Pietro; Dipierro, Nunzio; Paradiso, Annalisa; De Gara, Laura; Dipierro, Silvio; Viggiano, Luigi; de Pinto, Maria Concetta

    2015-11-01

    The alteration of growth patterns, through the adjustment of cell division and expansion, is a characteristic response of plants to environmental stress. In order to study this response in more depth, the effect of heat stress on growth was investigated in tobacco BY-2 cells. The results indicate that heat stress inhibited cell division, by slowing cell cycle progression. Cells were stopped in the pre-mitotic phases, as shown by the increased expression of CycD3-1 and by the decrease in the NtCycA13, NtCyc29 and CDKB1-1 transcripts. The decrease in cell length and the reduced expression of Nt-EXPA5 indicated that cell expansion was also inhibited. Since DNA methylation plays a key role in controlling gene expression, the possibility that the altered expression of genes involved in the control of cell growth, observed during heat stress, could be due to changes in the methylation state of their promoters was investigated. The results show that the altered expression of CycD3-1 and Nt-EXPA5 was consistent with changes in the methylation state of the upstream region of these genes. These results suggest that DNA methylation, controlling the expression of genes involved in plant development, contributes to growth alteration occurring in response to environmental changes.

  1. Effect of the inter-block spacing on the thermal performance of a PCM based heat sink

    Energy Technology Data Exchange (ETDEWEB)

    Faraji, M.; El Qarnia, H. [Cadi Ayyad Univ., Marrakech (Morocco). Faculte des sciences Semlalia, Dept. de physique, Laboratoire de mecanique des fluides et d' energetique; El Khadir, L. [Cadi Ayyad Univ., Marrakech (Morocco). Faculte des sciences Semlalia, Dept. de physique, Laboratoire d' tomatique de l' Environnement et Procedes de Transferts

    2010-07-01

    Advanced electronic devices require efficient thermal control systems. Heat transfer analysis of such systems is challenging because of constraints regarding space limitations, power consumption and noise level. This study considered the problem of melting and natural convection in a rectangular enclosure heated with 3 heat sources with a constant and uniform volumetric heat generation. The heat sources were protruding and mounted on a vertical conducting plate. Conjugate conduction in a plate and heat sources coupled with natural convection and melting process were examined in an effort to determine the effects of the inter-blocks spacing ratio on the thermal performance of the cooling PCM-heat sink. The percentage contribution of substrate heat conduction on the total removed heat from heat sources was also investigated. Correlations were derived for the non- dimensional secured working time and the corresponding melt fraction. In order to investigate the thermal behaviour of the proposed heat sink, a mathematical model was developed based on the mass, momentum and energy conservation equations. The results revealed that for lower inter-blocks spacing, the dimensionless secured working time needed by the chips to reach the critical temperature was maximized. The highest inter-blocks spacing ratio provoked a sudden rise in chip temperatures and thus reduced the dimensionless secured working time. It was concluded that this approach can be used in the design of PCM-based cooling systems. 9 refs., 2 tabs., 4 figs.

  2. Predictive Control of Hydronic Floor Heating Systems using Neural Networks and Genetic Algorithms

    DEFF Research Database (Denmark)

    Vinther, Kasper; Green, Torben; Østergaard, Søren

    2017-01-01

    . Additionally, weather disturbances such as solar heat gain can be anticipated and compensated for, while taking into account the slow dynamics of the floor. Together with a genetic algorithm, they provide a way to search for optimal future set-point sequences, when convexity and continuity in the solution......This paper presents the use a neural network and a micro genetic algorithm to optimize future set-points in existing hydronic floor heating systems for improved energy efficiency. The neural network can be trained to predict the impact of changes in set-points on future room temperatures...

  3. Hydraulic Control Method for Heating Systems of High-Rise Buildings

    Science.gov (United States)

    Makarov, D.; Chernenkov, V.; Likhachev, I.

    2017-11-01

    The following article reflects the ideas of possibility to increase energy efficiency of heating systems in high-rise buildings. The article also includes the principle ways of high-rise building heating systems operation as well as traditional engineering decisions aimed at the elimination of the increased pressure effect in heaters. The main disadvantages of such decisions are also presented for the reader. Moreover, the article offers the way of operation for the above-mentioned systems together with the equipment that implements this operation. An economic impact from such energy-saving technology application has been also evaluated.

  4. Linear and volumetric dimensional changes of injection-molded PMMA denture base resins.

    Science.gov (United States)

    El Bahra, Shadi; Ludwig, Klaus; Samran, Abdulaziz; Freitag-Wolf, Sandra; Kern, Matthias

    2013-11-01

    The aim of this study was to evaluate the linear and volumetric dimensional changes of six denture base resins processed by their corresponding injection-molding systems at 3 time intervals of water storage. Two heat-curing (SR Ivocap Hi Impact and Lucitone 199) and four auto-curing (IvoBase Hybrid, IvoBase Hi Impact, PalaXpress, and Futura Gen) acrylic resins were used with their specific injection-molding technique to fabricate 6 specimens of each material. Linear and volumetric dimensional changes were determined by means of a digital caliper and an electronic hydrostatic balance, respectively, after water storage of 1, 30, or 90 days. Means and standard deviations of linear and volumetric dimensional changes were calculated in percentage (%). Statistical analysis was done using Student's and Welch's t tests with Bonferroni-Holm correction for multiple comparisons (α=0.05). Statistically significant differences in linear dimensional changes between resins were demonstrated at all three time intervals of water immersion (p≤0.05), with exception of the following comparisons which showed no significant difference: IvoBase Hi Impact/SR Ivocap Hi Impact and PalaXpress/Lucitone 199 after 1 day, Futura Gen/PalaXpress and PalaXpress/Lucitone 199 after 30 days, and IvoBase Hybrid/IvoBase Hi Impact after 90 days. Also, statistically significant differences in volumetric dimensional changes between resins were found at all three time intervals of water immersion (p≤0.05), with exception of the comparison between PalaXpress and Futura Gen. Denture base resins (IvoBase Hybrid and IvoBase Hi Impact) processed by the new injection-molding system (IvoBase), revealed superior dimensional precision. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  5. Comparing the analgesic effect of heat patch containing iron chip and ibuprofen for primary dysmenorrhea: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Navvabi Rigi Shahindokht

    2012-08-01

    Full Text Available Abstract Background Primary dysmenorrhea is a common and sometimes disabling condition. In recent years, some studies aimed to improve the treatment of dysmenorrhea, and therefore, introduced several therapeutic measures. This study was designed to compare the analgesic effect of iron chip containing heat wrap with ibuprofen for the treatment of primary dysmenorrhea. Methods In this randomized (IRCT201107187038N2 controlled trial, 147 students (18–30 years old with the diagnosis of primary dysmenorrhea were enrolled considering the CONSORT guideline. Screening for primary dysmenorrhea was done by a two-question screening tool. The participants were randomly assigned into one of the intervention groups (heat Patch and ibuprofen. Data regarding the severity and emotional impact of the pain were recorded by a shortened version of McGill Pain Questionnaire (SF-MPQ. Student's t test was used for statistical analysis. Results The maximum and minimum pain severities were observed at 2 and 24 hours in both groups. The severity of sensual pain at 8, 12, and 24 hours was non-significantly less in the heat Patch group. There was also no significant difference between the groups regarding the emotional impact of pain at the first 2, 4, 8, 12 and 12 hours of menstruation. Conclusions Heat patch containing Iron chip has comparable analgesic effects to ibuprofen and can possibly be used for primary dysmenorrhea. Trial registration IRCT201107187038N2

  6. Performance Evaluation of HP/ORC (Heat Pump/Organic Rankine Cycle) System with Optimal Control of Sensible Thermal Storage

    DEFF Research Database (Denmark)

    Do Carmo, Carolina Madeira Ramos; Dumont, Olivier; Nielsen, Mads Pagh

    2016-01-01

    energy in periods of no thermal energy demand and reverses the heat pump cycle to supply electrical power. A dynamic model based on empirical data of this system is used to determine the annual performance. Furthermore, this work assesses the benefits of different control strategies that address...... of the users. Results show that real load control logic can lessen the adverse effects of cycling in the compressor of the system as well as increase the thermal demand (up to 33%) and the electrical demand (max. 8.4%) covered by renewable energy (solar). However, the extension of these improvements is highly...

  7. Controllability and stability of 3D heat conduction equation in a submicroscale thin film

    NARCIS (Netherlands)

    Heidari, H.; Zwart, Heiko J.; Malek, Alaeddin

    We obtain a closed form analytic solution for the Dual Phase Lagging equation. This equation is a linear, time-independent partial differential equation modeling the heat distribution in a thin film. The spatial domain is of micrometer and nanometer geometries. We show that the solution is described

  8. Control of melt-crystal interface shape during sapphire crystal growth by heat exchanger method

    Science.gov (United States)

    Wu, Ming; Liu, Lijun; Ma, Wencheng

    2017-09-01

    We numerically investigate the melt-crystal interface shape during the early stage of the solidification process when the crystal diameter increases. The contact angle between the melt-crystal interface and the crucible bottom wall is found obtuse during this stage, which is unfavorable for the crystal quality. We found that the obtuse contact angle is caused by the thermal resistance difference between the sapphire crystal and melt as well as the insufficient cooling effect of the crucible bottom. Two approaches are proposed to suppress the obtuse contact angle. The first approach is to increase the emissivity of the outer surface of crucible bottom. The second approach is to install a heat shield near the crucible bottom. The reduction of the emissivity of the heat shield is also favorable for the suppression of the obtuse contact angle. Compared with the increase of the emissivity of the crucible bottom, the installation of a heat shield is a more effective approach to prevent the appearance of an obtuse contact angle for the sake of reliability since a molybdenum heat shield can be reused and will not induce other impurities.

  9. Optimisation of Control Strategy at the Central Solar Heating Plant in Marstal, Denmark

    DEFF Research Database (Denmark)

    Heller, Alfred

    1999-01-01

    The central solar heating plant at Marstal is monitored since 1996. The data is analysed with focus on the applied constrol strategy for the solar collector field. Variable flow is applied which is not the case at the other plants compared. The project analysed the performance, compared...

  10. Dynamics and control of a heat pump assisted extractive dividing-wall column for bioethanol dehydration

    NARCIS (Netherlands)

    Patraşcu, Iulian; Bildea, Costin Sorin; Kiss, Anton A.

    Recently, a novel heat-pump-assisted extractive distillation process taking place in a dividing-wall column was proposed for bioethanol dehydration. This integrated design combines three distillation columns into a single unit that allows over 40% energy savings and low specific energy requirements

  11. The protein dispersibility index in the quality control of heat-treated ...

    African Journals Online (AJOL)

    The protein despersibility index (PDI) has been claimed to have the most constant response to the heating of FFSBs. In this study, the PDI method has been subjected to an inter-laboratory test, including the participation of eight laboratories. Seven FFSB samples were processed by dry extrusion at temperatures ranging ...

  12. Structural brain alterations of Down's syndrome in early childhood evaluation by DTI and volumetric analyses

    Energy Technology Data Exchange (ETDEWEB)

    Gunbey, Hediye Pinar; Bilgici, Meltem Ceyhan; Aslan, Kerim; Incesu, Lutfi [Ondokuz Mayis University, Faculty of Medicine, Department of Radiology, Kurupelit, Samsun (Turkey); Has, Arzu Ceylan [Bilkent University, National Magnetic Resonance Research Center, Ankara (Turkey); Ogur, Methiye Gonul [Ondokuz Mayis University, Department of Genetics, Samsun (Turkey); Alhan, Aslihan [Ufuk University, Department of Statistics, Ankara (Turkey)

    2017-07-15

    To provide an initial assessment of white matter (WM) integrity with diffusion tensor imaging (DTI) and the accompanying volumetric changes in WM and grey matter (GM) through volumetric analyses of young children with Down's syndrome (DS). Ten children with DS and eight healthy control subjects were included in the study. Tract-based spatial statistics (TBSS) were used in the DTI study for whole-brain voxelwise analysis of fractional anisotropy (FA) and mean diffusivity (MD) of WM. Volumetric analyses were performed with an automated segmentation method to obtain regional measurements of cortical volumes. Children with DS showed significantly reduced FA in association tracts of the fronto-temporo-occipital regions as well as the corpus callosum (CC) and anterior limb of the internal capsule (p < 0.05). Volumetric reductions included total cortical GM, cerebellar GM and WM volume, basal ganglia, thalamus, brainstem and CC in DS compared with controls (p < 0.05). These preliminary results suggest that DTI and volumetric analyses may reflect the earliest complementary changes of the neurodevelopmental delay in children with DS and can serve as surrogate biomarkers of the specific elements of WM and GM integrity for cognitive development. (orig.)

  13. Soil volumetric water content measurements using TDR technique

    Directory of Open Access Journals (Sweden)

    S. Vincenzi

    1996-06-01

    Full Text Available A physical model to measure some hydrological and thermal parameters in soils will to be set up. The vertical profiles of: volumetric water content, matric potential and temperature will be monitored in different soils. The volumetric soil water content is measured by means of the Time Domain Reflectometry (TDR technique. The result of a test to determine experimentally the reproducibility of the volumetric water content measurements is reported together with the methodology and the results of the analysis of the TDR wave forms. The analysis is based on the calculation of the travel time of the TDR signal in the wave guide embedded in the soil.

  14. Characterization and control of the microbial community affiliated with copper or aluminum heat exchangers of HVAC systems.

    Science.gov (United States)

    Schmidt, Michael G; Attaway, Hubert H; Terzieva, Silva; Marshall, Anna; Steed, Lisa L; Salzberg, Deborah; Hamoodi, Hameed A; Khan, Jamil A; Feigley, Charles E; Michels, Harold T

    2012-08-01

    Microbial growth in heating ventilation and air-conditioning (HVAC) systems with the subsequent contamination of indoor air is of increasing concern. Microbes and the subsequent biofilms grow easily within heat exchangers. A comparative study where heat exchangers fabricated from antimicrobial copper were evaluated for their ability to limit microbial growth was conducted using a full-scale HVAC system under conditions of normal flow rates using single-pass outside air. Resident bacterial and fungal populations were quantitatively assessed by removing triplicate sets of coupons from each exchanger commencing the fourth week after their installation for the next 30 weeks. The intrinsic biofilm associated with each coupon was extracted and characterized using selective and differential media. The predominant organisms isolated from aluminum exchangers were species of Methylobacterium of which at least three colony morphologies and 11 distinct PFGE patterns we found; of the few bacteria isolated from the copper exchangers, the majority were species of Bacillus. The concentrations and type of bacteria recovered from the control, aluminum, exchangers were found to be dependent on the type of plating media used and were 11,411-47,257 CFU cm(-2) per coupon surface. The concentration of fungi was found to average 378 CFU cm(-2). Significantly lower concentrations of bacteria, 3 CFU cm(-2), and fungi, 1 CFU cm(-2), were recovered from copper exchangers regardless of the plating media used. Commonly used aluminum heat exchangers developed stable, mixed, bacterial/fungal biofilms in excess of 47,000 organisms per cm(2) within 4 weeks of operation, whereas the antimicrobial properties of metallic copper were able to limit the microbial load affiliated with the copper heat exchangers to levels 99.97 % lower during the same time period.

  15. Volumetric capnography for the evaluation of chronic airways diseases

    Directory of Open Access Journals (Sweden)

    Veronez L

    2014-09-01

    Full Text Available Liliani de Fátima Veronez,1 Monica Corso Pereira,2 Silvia Maria Doria da Silva,2 Luisa Affi Barcaui,2 Eduardo Mello De Capitani,2 Marcos Mello Moreira,2 Ilma Aparecida Paschoalz2 1Department of Physical Therapy, University of Votuporanga (Educational Foundation of Votuporanga, Votuporanga, 2Department of Internal Medicine, School of Medical Sciences, State University of Campinas (UNICAMP, Campinas, Sao Paulo, BrazilBackground: Obstructive lung diseases of different etiologies present with progressive peripheral airway involvement. The peripheral airways, known as the silent lung zone, are not adequately evaluated with conventional function tests. The principle of gas washout has been used to detect pulmonary ventilation inhomogeneity and to estimate the location of the underlying disease process. Volumetric capnography (VC analyzes the pattern of CO2 elimination as a function of expired volume.Objective: To measure normalized phase 3 slopes with VC in patients with non-cystic fibrosis bronchiectasis (NCB and in bronchitic patients with chronic obstructive pulmonary disease (COPD in order to compare the slopes obtained for the groups.Methods: NCB and severe COPD were enrolled sequentially from an outpatient clinic (Hospital of the State University of Campinas. A control group was established for the NCB group, paired by sex and age. All subjects performed spirometry, VC, and the 6-Minute Walk Test (6MWT. Two comparisons were made: NCB group versus its control group, and NCB group versus COPD group. The project was approved by the ethical committee of the institution. Statistical tests used were Wilcoxon or Student’s t-test; P<0.05 was considered to be a statistically significant difference.Results: Concerning the NCB group (N=20 versus the control group (N=20, significant differences were found in body mass index and in several functional variables (spirometric, VC, 6MWT with worse results observed in the NCB group. In the comparison between

  16. Optimum charge of working fluids in horizontal rotating heat pipes

    Science.gov (United States)

    Nakayama, W.; Ohtsuka, Y.; Itoh, H.; Yoshikawa, T.

    The performance of wickless straight heat pipes rotating about their horizontal axes was investigated. The data reported herein were obtained with the copper pipes of 28 and 37 mm ID, 480 mm long with the evaporator and condenser sections each 170 mm long, and distilled water as the working fluid. The transition of two-phase flow in the heat pipe from the stratified to the annular structure occurs at a certain rotational speed (Froude number), and this affects the heat transfer performance. The volumetric percentage of liquid phase in the heat pipe (volumetric charge) determines the transition Froude numbers. For a given Froude number and a heat load, a too lean volumetric charge invites dry-out of the evaporator wall. A too high volumetric charge reduces the area for thin film evaporation and condensation on the rotating wall which dips and leaves the liquid reservoir of the stratified fluid. In the range of Froude numbers less than 13 which include many cases of heat pipe applications to conventional rotating machines, the volumetric charge of 10-14 percent minimizes the wall temperature difference between the evaporator and the condenser.

  17. Heat and moisture exchangers (HMEs) and heated humidifiers (HHs) in adult critically ill patients: a systematic review, meta-analysis and meta-regression of randomized controlled trials.

    Science.gov (United States)

    Vargas, Maria; Chiumello, Davide; Sutherasan, Yuda; Ball, Lorenzo; Esquinas, Antonio M; Pelosi, Paolo; Servillo, Giuseppe

    2017-05-29

    The aims of this systematic review and meta-analysis of randomized controlled trials are to evaluate the effects of active heated humidifiers (HHs) and moisture exchangers (HMEs) in preventing artificial airway occlusion and pneumonia, and on mortality in adult critically ill patients. In addition, we planned to perform a meta-regression analysis to evaluate the relationship between the incidence of artificial airway occlusion, pneumonia and mortality and clinical features of adult critically ill patients. Computerized databases were searched for randomized controlled trials (RCTs) comparing HHs and HMEs and reporting artificial airway occlusion, pneumonia and mortality as predefined outcomes. Relative risk (RR), 95% confidence interval for each outcome and I 2 were estimated for each outcome. Furthermore, weighted random-effect meta-regression analysis was performed to test the relationship between the effect size on each considered outcome and covariates. Eighteen RCTs and 2442 adult critically ill patients were included in the analysis. The incidence of artificial airway occlusion (RR = 1.853; 95% CI 0.792-4.338), pneumonia (RR = 932; 95% CI 0.730-1.190) and mortality (RR = 1.023; 95% CI 0.878-1.192) were not different in patients treated with HMEs and HHs. However, in the subgroup analyses the incidence of airway occlusion was higher in HMEs compared with HHs with non-heated wire (RR = 3.776; 95% CI 1.560-9.143). According to the meta-regression, the effect size in the treatment group on artificial airway occlusion was influenced by the percentage of patients with pneumonia (β = -0.058; p = 0.027; favors HMEs in studies with high prevalence of pneumonia), and a trend was observed for an effect of the duration of mechanical ventilation (MV) (β = -0.108; p = 0.054; favors HMEs in studies with longer MV time). In this meta-analysis we found no superiority of HMEs and HHs, in terms of artificial airway occlusion, pneumonia and

  18. Autologous fat grafting in facial volumetric restoration.

    Science.gov (United States)

    Piombino, Pasquale; Pasquale, Piombino; Marenzi, Gaetano; Gaetano, Marenzi; Dell'Aversana Orabona, Giovanni; Giovanni, Dell'Aversana Orabona; Califano, Luigi; Luigi, Califano; Sammartino, Gilberto; Gilberto, Sammartino

    2015-05-01

    The authors reported their surgical experience about structural fat grafting in the management of facial volumetric deficit. The purpose of this study was to assess the real indications, cosmetic results, complications, and global patient satisfaction of the Coleman technique in redefining facial contours in congenital and postoperative deformities. A retrospective analysis of 32 patients grafted according to Coleman's technique was performed, and the long-term outcomes and patient satisfaction were evaluated. The mean postoperative clinical follow-up was 14 months. The morphological changes were analyzed by comparing the photographic presurgical facial contour and the postoperative correction of soft tissue defects. All consecutive cases reported showed a progressive fat resorption for 3 months after surgery and its stable integration only after this period. Best results were performed in the treatment of genetically determined syndromes, such as the Franceschetti and Romberg syndromes. The authors suggest this surgical technique also for the treatment of unaesthetic cutaneous abscess cavity after incision and drainage. Unsatisfactory outcomes were obtained in the treatment of the posttraumatic facial scar, which needed more surgical procedures.

  19. Iterative reconstruction of volumetric particle distribution

    Science.gov (United States)

    Wieneke, Bernhard

    2013-02-01

    For tracking the motion of illuminated particles in space and time several volumetric flow measurement techniques are available like 3D-particle tracking velocimetry (3D-PTV) recording images from typically three to four viewing directions. For higher seeding densities and the same experimental setup, tomographic PIV (Tomo-PIV) reconstructs voxel intensities using an iterative tomographic reconstruction algorithm (e.g. multiplicative algebraic reconstruction technique, MART) followed by cross-correlation of sub-volumes computing instantaneous 3D flow fields on a regular grid. A novel hybrid algorithm is proposed here that similar to MART iteratively reconstructs 3D-particle locations by comparing the recorded images with the projections calculated from the particle distribution in the volume. But like 3D-PTV, particles are represented by 3D-positions instead of voxel-based intensity blobs as in MART. Detailed knowledge of the optical transfer function and the particle image shape is mandatory, which may differ for different positions in the volume and for each camera. Using synthetic data it is shown that this method is capable of reconstructing densely seeded flows up to about 0.05 ppp with similar accuracy as Tomo-PIV. Finally the method is validated with experimental data.

  20. Nonlinear control and online optimization of the burn condition in ITER via heating, isotopic fueling and impurity injection

    Science.gov (United States)

    Boyer, Mark D.; Schuster, Eugenio

    2014-10-01

    The ITER tokamak, the next experimental step toward the development of nuclear fusion reactors, will explore the burning plasma regime in which the plasma temperature is sustained mostly by fusion heating. Regulation of the fusion power through modulation of fueling and external heating sources, referred to as burn control, is one of the fundamental problems in burning plasma research. Active control will be essential for achieving and maintaining desired operating points, responding to changing power demands, and ensuring stable operation. Most existing burn control efforts use either non-model-based control techniques or designs based on linearized models. These approaches must be designed for particular operating points and break down for large perturbations. In this work, we utilize a spatially averaged (zero-dimensional) nonlinear model to synthesize a multi-variable nonlinear burn control strategy that can reject large perturbations and move between operating points. The controller uses all of the available actuation techniques in tandem to ensure good performance, even if one or more of the actuators saturate. Adaptive parameter estimation is used to improve the model parameter estimates used by the feedback controller in real-time and ensure asymptotic tracking of the desired operating point. In addition, we propose the use of a model-based online optimization algorithm to drive the system to a state that minimizes a given cost function, while respecting input and state constraints. A zero-dimensional simulation study is presented to show the performance of the adaptive control scheme and the optimization scheme with a cost function weighting the fusion power and temperature tracking errors.

  1. Predictive Control of Hydronic Floor Heating Systems using Neural Networks and Genetic Algorithms

    DEFF Research Database (Denmark)

    Vinther, Kasper; Green, Torben; Østergaard, Søren

    2017-01-01

    This paper presents the use a neural network and a micro genetic algorithm to optimize future set-points in existing hydronic floor heating systems for improved energy efficiency. The neural network can be trained to predict the impact of changes in set-points on future room temperatures. Additio...... space is not guaranteed. Evaluation of the performance of multiple neural networks is performed, using different levels of information, and optimization results are presented on a detailed house simulation model.......This paper presents the use a neural network and a micro genetic algorithm to optimize future set-points in existing hydronic floor heating systems for improved energy efficiency. The neural network can be trained to predict the impact of changes in set-points on future room temperatures...

  2. Can the Ocean's Heat Engine Control Horizontal Circulation? Insights From the Caspian Sea

    Science.gov (United States)

    Bruneau, Nicolas; Zika, Jan; Toumi, Ralf

    2017-10-01

    We investigate the role of the ocean's heat engine in setting horizontal circulation using a numerical model of the Caspian Sea. The Caspian Sea can be seen as a virtual laboratory—a compromise between realistic global models that are hampered by long equilibration times and idealized basin geometry models, which are not constrained by observations. We find that increases in vertical mixing drive stronger thermally direct overturning and consequent conversion of available potential to kinetic energy. Numerical solutions with water mass structures closest to observations overturn 0.02-0.04 × 106 m3/s (sverdrup) representing the first estimate of Caspian Sea overturning. Our results also suggest that the overturning is thermally forced increasing in intensity with increasing vertical diffusivity. Finally, stronger thermally direct overturning is associated with a stronger horizontal circulation in the Caspian Sea. This suggests that the ocean's heat engine can strongly impact broader horizontal circulations in the ocean.

  3. Study on several temperature control methods of non heated overflow container

    Science.gov (United States)

    Yang, Haozhe

    2017-04-01

    For a simple water overflow container, we try to find the best solution through which we can keep the temperature as close as possible to the initial temperature without wasting too much water. We build models in time and space. Model in time: We mainly consider convective heat transfer of water and air, heat transfer of container and evaporation of water.we get curves of temperature versus time under different situations. Through calculating and comparing the total water consumption of each program,find out the best plan. Model in space:We build two sub models in the model in space. The difference is the position of added water.we can get some images about the temperature changes with distance in different layers, and find the best strategy.

  4. Electromagnetic control of heat transport within a rectangular channel filled with flowing liquid metal

    Science.gov (United States)

    Modestov, M.; Kolemen, E.; Fisher, A. E.; Hvasta, M. G.

    2018-01-01

    The behavior of free-surface, liquid-metal flows exposed to both magnetic fields and an injected electric current is investigated via experiment and numerical simulations. The purpose of this paper is to provide an experimental and theoretical proof-of-concept for enhanced thermal mixing within fast-flowing, free-surface, liquid-metal plasma facing components that could be used in next-generation fusion reactors. The enhanced hydrodynamic and thermal mixing induced by non-uniform current density near the electrodes appears to improve heat transfer through the thickness of the flowing metal. Also, the outflow heat flux profile is strongly affected by the impact of the J  ×  B forces on flow velocity. The experimental results are compared to COMSOL simulations in order to lay the groundwork for future liquid-metal research.

  5. A randomized, controlled, clinical trial of a chemically-reactive heated humidifier.

    Science.gov (United States)

    Broach, S D; Durbin, C G

    2001-01-01

    Inspired gases can be warmed and humidified in a variety of ways. The effect of a chemically-reactive heated heat and moisture exchanger/hygroscopic condenser humidifier (HME/HCH) on secretions, rate of core body warming, blood loss, and time to extubation was studied in hypothermic post-cardiac surgery patients. Fifty patients with normal ventricular function, undergoing coronary bypass grafting, were randomized to receive either a conventional HME (Gibeck, Humid-Vent 1 [PN 11112], Hudson RCI, Temecula, California) or a chemically-heated HME (Thermax HCH Filter [PN 9302], Enternet Medical, Las Vegas, Nevada) following surgery or on arrival in the ICU. Effects on secretions, core temperature, postoperative bleeding, duration of intubation, and added resistance were measured. The Thermax weighs 67 g and adds 79 mL of dead space. The Humid-Vent 1 weighs 9.4 g and adds 10 mL of dead space. There was no significant difference between the 2 devices in time to extubation, blood loss, or quality or quantity of secretions. Use of the Thermax device, however, resulted in a more rapid rise in body temperature (0.299 degrees C/h with the Thermax vs 0.073 degrees C/h with the Humid-Vent 1, p = 0.001) and more added resistance (0.0672 cm H(2)O/L/s with the Thermax vs 0.0123 cm H(2)O/L/s with the Humid-Vent 1, p = 0.00000172). The Thermax chemically-heated HME results in more rapid warming of mildly hypothermic patients following cardiopulmonary bypass than does a conventional passive HME.

  6. Nonhazardous Chemical Treatments and Smart Monitoring and Control System for Heating and Cooling Systems

    Science.gov (United States)

    2007-06-01

    corrosion project developed extensive corrosion data on cooling tow - ers and steam boiler condensate systems that are part of heating, ventila- tion, and...corrosion coupons in each system. Garratt-Callahan monitored bacteria levels in cooling tow - ers. ERDC/CERL TR-07-20 44 5 Economic Summary...at the Red River Army Depot at a high temperature Dynamometer brake testing sys- tem. At this facility, the ERDC-CERL boiler inspector was impressed

  7. Self-heating of wood pellets and possibilities for its control

    Energy Technology Data Exchange (ETDEWEB)

    Jaervinen, S.; Lehtovaara, J. (Vapo Oy, Jyvaeskylae (Finland)), Email: seppo.jarvinen@vapo.fi, Email: jaakko.lehtovaara@vapo.fi; Siren, P. (Joensuu Univ. (Finland)), Email: pekka.siren@joensuu.fi; Pakkanen, H.; Salo, M.; Alen, R. (Univ. of Jyvaeskylae (Finland). Lab. of Applied Chemistry), Email: hannu.pakkanen@jyu.fi, Email: marja.h.salo@jyu.fi, Email: raimo.j.alen@jyu.fi

    2009-07-01

    The share of moist sawdust in the manufacturing of wood pellets has rapidly increased because of the lack of dry raw materials. however, during the drying process the thermochemical degradation of wood is taking place and some volatile organic compounds (VOCs) are released. The release of VOCs is occurring also during transportation and storage of pellets as a result of the self-heating process leading to the formation of malodorous and toxic emissions such as hexanal and carbon monoxide. In this study, to clarify the chemical background of the self-heating process and the formation of harmful compounds the amount and composition of the lipids, especially the fraction of fatty acids (i.e., both free and esterified acid constituents) in raw materials and pellets were investigated. In addition, the chemical changes in the lipids during different laboratory-, pilot- and plant-scale processes were monitored. The results clearly indicated that the self-heating problem was caused by the moist and fresh Scots pine (Pinus sylvestris) feedstock material having a high amount of fatty acids. The use of dryers seemed to contribute the breakdown of the ester bonds of these acids and the subsequent exothermic autoxidation of unsaturated fatty acids, thus leading to the formation of malodorous aldehydes besides the toxic carbon monoxide. The self-heating could be most effectively diminished by handling the fresh sawdust at elevated temperatures. Furthermore, a prolonged handling time decreased the total amount of the lipids, but not as effectively as an increase in the process temperature. (orig.)

  8. Demonstrating Hybrid Heat Transport and Energy Conversion System Performance Characterization Using Intelligent Control Systems

    Energy Technology Data Exchange (ETDEWEB)

    Ostrum, Lee [Univ. of Idaho and Idaho Falls Center, Idaho Falls, ID (United States); Manic, Milos [Virginia Commonwealth Univ., Richmond, VA (United States)

    2017-09-28

    The debate continues on the magnitude and validity of climate change caused by human activities. However, there is no debate about the need to make buildings, modes of transportation, factories, and homes as energy efficient as possible. Given that climate change could occur with the wasteful use of fossil fuel and the fact that fossil energy costs could and will swing wildly, it is imperative that every effort be made to utilize energy sources to their fullest. Hybrid energy systems (HES) are two or more separate energy producers used together to produce energy commodities. The HES this report focuses on is the use of nuclear reactor waste heat as a source of further energy utilization. Nuclear reactors use a fluid to cool the core and produce the steam needed for the production of electricity. Traditionally this steam, or coolant, is used to convert the energy then cooled elsewhere. The heat is released into the environment without being used further. By adding technologies to nuclear reactors to use the wasted heat, a system can be developed to make more than just electricity and allow for loading following capabilities.

  9. Crystallization Analysis and Control of Ammonia-Based Air Source Absorption Heat Pump in Cold Regions

    Directory of Open Access Journals (Sweden)

    Wei Wu

    2013-01-01

    Full Text Available Energy consumption of heating and domestic hot water is very high and will keep increasing. Air source absorption heat pump (ASAHP was proposed to overcome the problems of low energy efficiency and high air pollution existing in boiler systems, as well as the problem of bad performance under low ambient temperatures for electrical heat pumps. In order to investigate the crystallization possibility of ammonia-salt ASAHP, crystallization margin (evaluated by solution mass concentration at generating temperature ranging from 100 to 150°C, evaporating temperature from −30 to 10°C, and condensing temperature from 30 to 65°C are analyzed. To prevent the NH3–NaSCN solution from crystallizing, ASAHP integrated with pressure booster located between the evaporator and absorber is simulated. Analysis and comparisons show that NH3–NaSCN is easy to crystallize at relatively high generating temperature, low evaporating temperature, and low condensing temperature. But crystallization margin of NH3–LiNO3 can always stay above 5% for most conditions, keeping away from crystallization. Pressure booster can effectively avoid the crystallization problem that will take place in the NH3–NaSCN ASAHP system.

  10. Identification of thermophysical characteristics of materials using heating probe

    OpenAIRE

    Abdelaziz Nasr; Abdulmajeed S. Al-Ghamdi; Mohammad S. Alsoufi

    2016-01-01

    This paper investigates the numerical analysis to determine the thermo-physical characteristics of materials. This method is based on a heating probe kept at a constant temperature and maintained in contact with a cylindrical sample. The heat power dissipated in the sample is measured by the probe. The results address to identify simultaneously the thermal conductivity, the volumetric heat capacity and the heat transfer coefficient using the inverse problem.

  11. Three-dimensional volumetric quantification of fat loss following cryolipolysis.

    Science.gov (United States)

    Garibyan, Lilit; Sipprell, William H; Jalian, H Ray; Sakamoto, Fernanda H; Avram, Mathew; Anderson, R Rox

    2014-02-01

    Cryolipolysis is a noninvasive and well-tolerated treatment for reduction of localized subcutaneous fat. Although several studies demonstrate the safety and efficacy of this procedure, volumetric fat reduction from this treatment has not been quantified. This prospective study investigated the change in volume of fat after cryolipolysis treatment using three-dimensional (3D) photography. A prospective study of subjects treated with cryolipolysis on the flank (love handle) was performed at Massachusetts General Hospital. Volume measurements were performed with a Canfield Scientific Vectra three-dimensional camera and software to evaluate the amount of post procedure volume change. Clinical outcomes were assessed with caliper measurements, subject surveys, and blinded physician assessment of photographs. Eleven subjects were enrolled in this study. Each subject underwent a single cycle of cryolipolysis to one flank. The untreated flank served as an internal control. The follow-up time after treatment was 2 months. The mean amount of calculated absolute fat volume loss using 3D photography from baseline to 2 months follow-up visit was 56.2 ± 25.6 from the treatment site and 16.6 ± 17.6 cc from the control (P fat removal methodology that on average leads to 39.6 cc of fat loss of the treated flank at 2 months after a single treatment cycle. © 2013 Wiley Periodicals, Inc.

  12. Cortical thickness and brain volumetric analysis in body dysmorphic disorder.

    Science.gov (United States)

    Madsen, Sarah K; Zai, Alex; Pirnia, Tara; Arienzo, Donatello; Zhan, Liang; Moody, Teena D; Thompson, Paul M; Feusner, Jamie D

    2015-04-30

    Individuals with body dysmorphic disorder (BDD) suffer from preoccupations with perceived defects in physical appearance, causing severe distress and disability. Although BDD affects 1-2% of the population, the neurobiology is not understood. Discrepant results in previous volumetric studies may be due to small sample sizes, and no study has investigated cortical thickness in BDD. The current study is the largest neuroimaging analysis of BDD. Participants included 49 medication-free, right-handed individuals with DSM-IV BDD and 44 healthy controls matched by age, sex, and education. Using high-resolution T1-weighted magnetic resonance imaging, we computed vertex-wise gray matter (GM) thickness on the cortical surface and GM volume using voxel-based morphometry. We also computed volumes in cortical and subcortical regions of interest. In addition to group comparisons, we investigated associations with symptom severity, insight, and anxiety within the BDD group. In BDD, greater anxiety was significantly associated with thinner GM in the left superior temporal cortex and greater GM volume in the right caudate nucleus. There were no significant differences in cortical thickness, GM volume, or volumes in regions of interest between BDD and control subjects. Subtle associations with clinical symptoms may characterize brain morphometric patterns in BDD, rather than large group differences in brain structure. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  13. Heat sink welding of austenitic stainless steel pipes to control distortion and residual stress

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, H.; Albert, S.K.; Bhaduri, A.K. [Materials Technology Div., Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

    2007-07-01

    Construction of India's Prototype Fast Breeder Reactor (PFBR) involves extensive welding of austenitic stainless steels pipes of different dimensions. Due to high thermal expansion coefficient and poor thermal conductivity of this class of steels, welding can result in significant distortion of these pipes. Attempts to arrest this distortion can lead to high levels of residual stresses in the welded parts. Heat sink welding is one of the techniques often employed to minimize distortion and residual stress in austenitic stainless steel pipe welding. This technique has also been employed to repair welding of the piping of the Boiling Water Reactors (BWRs) subjected to radiation induced intergranular stress corrosion cracking (IGSCC). In the present study, a comparison of the distortion in two pipe welds, one made with heat sink welding and another a normal welds. Pipes of dimensions 350{phi} x 250(L) x 8(t) mm was fabricated from 316LN plates of dimensions 1100 x 250 x 8 mm by bending and long seam (L-seam) welding by SMAW process. Two fit ups with a root gap of 2 mm, land height of 1mm and a groove angle of 70 were prepared using these pipes for circumferential seam (C-seam) welding. Dimensions at predetermined points in the fit up were made before and after welding to check the variation in radius, circumference and and ovality of the pipes. Root pass for both the pipe fit up were carried out using conventional GTAW process with 1.6 mm AWS ER 16-8-2 as consumables. Welding of one of the pipe fit ups were completed using conventions GTAW process while the other was completed using heat sink welding. For second and subsequent layers of welding using this process, water was sprayed at the root side of the joint while welding was in progress. Flow rate of the water was {proportional_to}6 1/minute. Welding parameters employed were same as those used for the other pipe weld. Results of the dimensional measurements showed that there is no circumferential shrinkage in

  14. Additive Effects of Heating and Exercise on Baroreflex Control of Heart Rate in Healthy Males.

    Science.gov (United States)

    Peçanha, Tiago; Forjaz, Claudia Lucia de Moraes; Low, David Andrew

    2017-08-31

    This study assessed the additive effects of passive heating and exercise on cardiac baroreflex sensitivity (cBRS) and heart rate variability (HRV). Twelve healthy young men (25±1 yrs, 23.8±0.5 kg/m(2)) randomly underwent two experimental sessions: heat stress (HS; whole-body heat stress using a tube-lined suit to increase core temperature by ~1°C) and normothermia (NT). Each session was composed of a: pre-intervention rest (REST1); HS or NT interventions; post-intervention rest (REST2); and 14 min of cycling exercise [7 min at 40%HRreserve (EX1) and 7 min at 60%HRreserve (EX2)]. Heart rate and finger blood pressure were continuously recorded. cBRS was assessed using the sequence (cBRSSEQ) and transfer function (cBRSTF) methods. HRV was assessed using the indices SDNN (standard deviation of RR intervals) and RMSSD (root mean square of successive RR intervals). cBRS and HRV were not different between sessions during EX1 and EX2 (i.e. matched heart rate conditions: EX1=116±3 vs. 114±3, EX2=143±4 vs. 142±3 bpm; but different workloads: EX1=50±9 vs. 114±8, EX2=106±10 vs. 165±8 Watts; for HS and NT, respectively; Pheart rates), cBRS and HRV were significantly reduced in HS (cBRSSEQ = 1.6±0.3 vs. 0.6±0.1 ms/mmHg, P<0.01; SDNN = 2.3±0.1 vs. 1.3±0.2 ms, P<0.01). In conclusion, in conditions matched by HR, the addition of heat stress to exercise does not affect cBRS and HRV. Alternatively, in workload-matched conditions, the addition of heat to exercise results in reduced cBRS and HRV compared to exercise in normothermia. Copyright © 2017, Journal of Applied Physiology.

  15. Gas-operated heat pump for monovalent space heating and tap water heating. A seizable contribution to carbon dioxide emission control; Gasbetriebene Waermepumpe zur monovalenten Raumbeheizung und Trinkwassererwaermung. Ein greifbarer Beitrag zur Reduktion der CO{sub 2}-Emissionen

    Energy Technology Data Exchange (ETDEWEB)

    Heikrodt, K.; Heckt, R. [Viessmann Werke GmbH und Co., Allendorf (Germany)

    1999-07-01

    The project had the objectives to develop a Vuilleumier heat pump for space heating and make an experimental study testing it as a heat generator for a heating system for one- and multi-family houses. Apart from monovalent operation, the following boundary conditions were defined: provision for connection to existing heating systems, even radiator heatings with 75 C/60 C, tap water heating, and air-source heat. Performance constant, manufacturing cost, freedom from maintenance, and service life were taken into consideration in the design, rating and construction of the unit. (orig.) [German] Ziel des Vorhabens war die Entwicklung einer Vuilleumier-Waermepumpe zur Raumbeheizung und deren experimentelle Untersuchung als Waermeerzeuger fuer ein Heizungssystem in Ein- und Mehrfamilienhaeusern. Als Rahmebedingungen wurden neben einer monovalenten Betriebsweise auch die moegliche Anbindung an bestehende Heizungssysteme, sogar Radiatorheizungen mit 75 C/60 C, Trinkwassererwaermung und Luft als Waermequelle festgelegt. Leistungszahl, Herstellkosten, Wartungsfreiheit und Lebensdauer wurden in Konzeption, Auslegung und Konstruktion beruecksichtigt. (orig.)

  16. Solenoidal filtering of volumetric velocity measurements using Gaussian process regression

    NARCIS (Netherlands)

    Azijli, I.; Dwight, R.P.

    2015-01-01

    Volumetric velocity measurements of incompressible flows contain spurious divergence due to measurement noise, despite mass conservation dictating that the velocity field must be divergence-free (solenoidal). We investigate the use of Gaussian process regression to filter spurious divergence,

  17. Oscillating side-branch enhancements of thermoacoustic heat exchangers

    Science.gov (United States)

    Swift, Gregory W.

    2003-05-13

    A regenerator-based engine or refrigerator has a regenerator with two ends at two different temperatures, through which a gas oscillates at a first oscillating volumetric flow rate in the direction between the two ends and in which the pressure of the gas oscillates, and first and second heat exchangers, each of which is at one of the two different temperatures. A dead-end side branch into which the gas oscillates has compliance and is connected adjacent to one of the ends of the regenerator to form a second oscillating gas flow rate additive with the first oscillating volumetric flow rate, the compliance having a volume effective to provide a selected total oscillating gas volumetric flow rate through the first heat exchanger. This configuration enables the first heat exchanger to be configured and located to better enhance the performance of the heat exchanger rather than being confined to the location and configuration of the regenerator.

  18. Controlling the molecular structure and physical properties of artificial honeybee silk by heating or by immersion in solvents.

    Science.gov (United States)

    Huson, Mickey G; Church, Jeffrey S; Poole, Jacinta M; Weisman, Sarah; Sriskantha, Alagacone; Warden, Andrew C; Campbell, Peter M; Ramshaw, John A M; Sutherland, Tara D

    2012-01-01

    Honeybee larvae produce silken cocoons that provide mechanical stability to the hive. The silk proteins are small and non-repetitive and therefore can be produced at large scale by fermentation in E. coli. The recombinant proteins can be fabricated into a range of forms; however the resultant material is soluble in water and requires a post production stabilizing treatment. In this study, we describe the structural and mechanical properties of sponges fabricated from artificial honeybee silk proteins that have been stabilized in aqueous methanol baths or by dry heating. Aqueous methanol treatment induces formation of ß-sheets, with the amount of ß-sheet dictated by methanol concentration. Formation of ß-sheets renders sponges insoluble in water and generates a reversibly compressible material. Dry heat treatments at 190°C produce a water insoluble material, that is stiffer than the methanol treated equivalent but without significant secondary structural changes. Honeybee silk proteins are particularly high in Lys, Ser, Thr, Glu and Asp. The properties of the heat treated material are attributed to generation of lysinoalanine, amide (isopeptide) and/or ester covalent cross-links. The unique ability to stabilize material by controlling secondary structure rearrangement and covalent cross-linking allows us to design recombinant silk materials with a wide range of properties.

  19. Controlling the molecular structure and physical properties of artificial honeybee silk by heating or by immersion in solvents.

    Directory of Open Access Journals (Sweden)

    Mickey G Huson

    Full Text Available Honeybee larvae produce silken cocoons that provide mechanical stability to the hive. The silk proteins are small and non-repetitive and therefore can be produced at large scale by fermentation in E. coli. The recombinant proteins can be fabricated into a range of forms; however the resultant material is soluble in water and requires a post production stabilizing treatment. In this study, we describe the structural and mechanical properties of sponges fabricated from artificial honeybee silk proteins that have been stabilized in aqueous methanol baths or by dry heating. Aqueous methanol treatment induces formation of ß-sheets, with the amount of ß-sheet dictated by methanol concentration. Formation of ß-sheets renders sponges insoluble in water and generates a reversibly compressible material. Dry heat treatments at 190°C produce a water insoluble material, that is stiffer than the methanol treated equivalent but without significant secondary structural changes. Honeybee silk proteins are particularly high in Lys, Ser, Thr, Glu and Asp. The properties of the heat treated material are attributed to generation of lysinoalanine, amide (isopeptide and/or ester covalent cross-links. The unique ability to stabilize material by controlling secondary structure rearrangement and covalent cross-linking allows us to design recombinant silk materials with a wide range of properties.

  20. Application of a Novel Liquid Nitrogen Control Technique for Heat Stress and Fire Prevention in Underground Mines.

    Science.gov (United States)

    Shi, Bobo; Ma, Lingjun; Dong, Wei; Zhou, Fubao

    2015-01-01

    With the continually increasing mining depths, heat stress and spontaneous combustion hazards in high-temperature mines are becoming increasingly severe. Mining production risks from natural hazards and exposures to hot and humid environments can cause occupational diseases and other work-related injuries. Liquid nitrogen injection, an engineering control developed to reduce heat stress and spontaneous combustion hazards in mines, was successfully utilized for environmental cooling and combustion prevention in an underground mining site named "Y120205 Working Face" (Y120205 mine) of Yangchangwan colliery. Both localized humidities and temperatures within the Y120205 mine decreased significantly with liquid nitrogen injection. The maximum percentage drop in temperature and humidity of the Y120205 mine were 21.9% and 10.8%, respectively. The liquid nitrogen injection system has the advantages of economical price, process simplicity, energy savings and emission reduction. The optimized heat exchanger used in the liquid nitrogen injection process achieved superior air-cooling results, resulting in considerable economic benefits.

  1. Takagi-Sugeno control of nocturnal temperature in greenhouses using air heating.

    Science.gov (United States)

    Nachidi, M; Rodríguez, F; Tadeo, F; Guzman, J L

    2011-04-01

    A solution to the problem of controlling the minimum temperature in greenhouses using controllers developed from nonlinear models of the system is discussed and applied on a real greenhouse. More precisely, the controllers designed are Takagi-Sugeno type controllers, and the proposed design method is an iterative method based on solving a set of Linear Matrix Inequalities, which ensures stability and performance in closed-loop. The tests in a real greenhouse show that it is possible to design controllers for control of nocturnal temperature that give good performance, and guarantee stability in a wide range of working conditions. Copyright © 2010 ISA. Published by Elsevier Ltd. All rights reserved.

  2. Hierarchical Control Strategy of Heat and Power for Zero Energy Buildings including Hybrid Fuel Cell/Photovoltaic Power Sources and Plug-in Electric Vehicle

    DEFF Research Database (Denmark)

    Ghiasi, Mohammad Iman; Aliakbar Golkar, Masoud; Hajizadeh, Amin

    2016-01-01

    This paper presents a hierarchical control strategy for heat and electric power control of a building integrating hybrid renewable power sources including photovoltaic, fuel cell and battery energy storage with Plug-in Electric Vehicles (PEV) in smart distribution systems. Because of the controll......This paper presents a hierarchical control strategy for heat and electric power control of a building integrating hybrid renewable power sources including photovoltaic, fuel cell and battery energy storage with Plug-in Electric Vehicles (PEV) in smart distribution systems. Because...

  3. Accurate measurements of experimental parameters in supercritical fluid chromatography. I. Extent of variations of the mass and volumetric flow rates.

    Science.gov (United States)

    Tarafder, Abhijit; Guiochon, Georges

    2013-04-12

    Previous reports have highlighted the influence of the properties of the mobile phase flow rate on the column performance achieved in supercritical fluid chromatography (SFC). In SFC both the mass and the volumetric flow rates have unique influences on the chromatographic performance and the determination of their exact values is critical. It is well understood that the mass flow rate stays constant along an SFC system whereas the volumetric flow rate may vary considerably, but the extent of these variations and the role of the individual operating parameters in influencing these variations have not been clearly reported yet. The factors that control the mass and the volumetric flow rates in an SFC system are discussed and the possible extent of variations of these flow rates under different operating pressures and temperatures are demonstrate quantitatively. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Statement on a heat treatment to control Agrilus planipennis

    DEFF Research Database (Denmark)

    Baker, R.; Candresse, T.; Dormannsné Simon, E.

    2012-01-01

    the publication of this scientific opinion, the US Authorities submitted a new proposal to the European Commission, consisting in a new heat treatment (71.1 °C/60 min). The EFSA Panel on Plant Health was asked to consider whether this new proposal was within the scope of the published opinion and, if not...... lists the information required in the checklist presented in the Panel’s draft guidance document on methodology for evaluation of the effectiveness of options to reduce the risk of introduction and spread of organisms harmful to plant health in the EU territory, currently under public consultation...

  5. Size-controlled heating ability of CoFe2O4 nanoparticles for hyperthermia applications

    Science.gov (United States)

    Phong, P. T.; Phuc, N. X.; Nam, P. H.; Chien, N. V.; Dung, D. D.; Linh, P. H.

    2018-02-01

    The magnetic properties and heating capacity of cobalt ferrite (CoFe2O4) nanoparticles 13-24 nm in size were studied. Results showed that the specific absorption rate of the nanoparticles strongly depended on their magnetic properties and particle size. Specific absorption rate values decreased with increased particle size, and the smallest CoFe2O4 nanoparticles (13.5 nm) exhibited the highest specific absorption rate. The mechanism underlying the decrease in specific absorption rate of the CoFe2O4 nanoparticles with increased particle size was also discussed.

  6. Rotating magnetic macrospheres as heating mechanism for remote controlled drug release

    Energy Technology Data Exchange (ETDEWEB)

    Steinke, Franziska [Department of Biomedical Engineering, University of Applied Sciences, Jena (Germany); Andrae, Wilfried [Department of Biomedical Engineering, University of Applied Sciences, Jena (Germany) and Institute for Physical High Technology e. V., Jena (Germany)]. E-mail: wilfried.andrae@t-online.de; Heide, Rainer [Am Steinborn 111, 07749 Jena (Germany); Werner, Christoph [Department of Biomedical Engineering, University of Applied Sciences, Jena (Germany); Bellemann, Matthias Erich [Department of Biomedical Engineering, University of Applied Sciences, Jena (Germany)

    2007-04-15

    A permanent magnetic macrosphere (diameter: 5 mm) spherically seated in an oil bearing inside an experimental capsule (comparable to a hard gelatine capsule size 2) is turned by a rotating magnetic field (H {<=} 5 kA/m; frequency {nu}{<=}500 Hz) and causes a temperature rise up to about 60 deg. C. In order to find further possible improvements, the experimental results were compared to theoretical expectations. First experiments using improved thermal isolation yielded temperatures of about 100 deg. C. The heating can be used as a mechanism to remotely release drugs in the gastrointestinal tract.

  7. Means-End based Functional Modeling for Intelligent Control: Modeling and Experiments with an Industrial Heat Pump System

    DEFF Research Database (Denmark)

    Saleem, Arshad

    2007-01-01

    The purpose of this paper is to present a Multilevel Flow Model (MFM) of an industrial heat pump system and its use for diagnostic reasoning. MFM is functional modeling language supporting an explicit means-ends intelligent control strategy for large industrial process plants. The model is used...... in several diagnostic experiments analyzing different fault scenarios. The model and results of the experiments are explained and it is shown how MFM based intelligent modeling and automated reasoning can improve the fault diagnosis process significantly....

  8. Validation of simultaneous volumetric and HPLC methods for the determination of pridinol mesylate in raw material.

    Science.gov (United States)

    Simionato, Laura D; Ferello, Leonardo; Stamer, Sebastián; Zubata, Patricia D; Segall, Adriana I

    2013-01-01

    Simple, sensitive, and economical simultaneous volumetric and HPLC methods for the determination of pridinol mesylate in raw material have been developed. The volumetric method is based on the reaction of pridinol with sodium lauryl sulphate in diluted sulphuric acid. Dimethyl yellow was used as indicator to detect the end point of the titration in aqueous/organic layer. The HPLC method for the determination of pridinol mesylate employs a reverse phase C18 column at ambient temperature with a mobile phase consisting of acetonitrile: 0.05 M potassium dihydrogen phosphate, pH adjusted to 5.0 (1 : 2, v/v). The flow rate was 0.8 mL/min. Quantitation was achieved with UV detection at 258 nm based on peak area. Both methods were found to be suitable for the quality control of pridinol mesylate in raw material.

  9. Effects of prepolymerized particle size and polymerization kinetics on volumetric shrinkage of dental modeling resins.

    Science.gov (United States)

    Kwon, Tae-Yub; Ha, Jung-Yun; Chun, Ju-Na; Son, Jun Sik; Kim, Kyo-Han

    2014-01-01

    Dental modeling resins have been developed for use in areas where highly precise resin structures are needed. The manufacturers claim that these polymethyl methacrylate/methyl methacrylate (PMMA/MMA) resins show little or no shrinkage after polymerization. This study examined the polymerization shrinkage of five dental modeling resins as well as one temporary PMMA/MMA resin (control). The morphology and the particle size of the prepolymerized PMMA powders were investigated by scanning electron microscopy and laser diffraction particle size analysis, respectively. Linear polymerization shrinkage strains of the resins were monitored for 20 minutes using a custom-made linometer, and the final values (at 20 minutes) were converted into volumetric shrinkages. The final volumetric shrinkage values for the modeling resins were statistically similar (P > 0.05) or significantly larger (P resin and were related to the polymerization kinetics (P resin structures rather than the use of dental modeling resins.

  10. Controls on permafrost thaw in a coupled groundwater-flow and heat-transport system: Iqaluit Airport, Nunavut, Canada

    Science.gov (United States)

    Shojae Ghias, Masoumeh; Therrien, René; Molson, John; Lemieux, Jean-Michel

    2017-05-01

    Numerical simulations of groundwater flow and heat transport are used to provide insight into the interaction between shallow groundwater flow and thermal dynamics related to permafrost thaw and thaw settlement at the Iqaluit Airport taxiway, Nunavut, Canada. A conceptual model is first developed for the site and a corresponding two-dimensional numerical model is calibrated to the observed ground temperatures. Future climate-warming impacts on the thermal regime and flow system are then simulated based on climate scenarios proposed by the Intergovernmental Panel on Climate Change (IPCC). Under climate warming, surface snow cover is identified as the leading factor affecting permafrost degradation, including its role in increasing the sensitivity of permafrost degradation to changes in various hydrogeological factors. In this case, advective heat transport plays a relatively minor, but non-negligible, role compared to conductive heat transport, due to the significant extent of low-permeability soil close to surface. Conductive heat transport, which is strongly affected by the surface snow layer, controls the release of unfrozen water and the depth of the active layer as well as the magnitude of thaw settlement and frost heave. Under the warmest climate-warming scenario with an average annual temperature increase of 3.23 °C for the period of 2011-2100, the simulations suggest that the maximum depth of the active layer will increase from 2 m in 2012 to 8.8 m in 2100 and, over the same time period, thaw settlement along the airport taxiway will increase from 0.11 m to at least 0.17 m.

  11. Volumetric Properties of the Mixture Butan-2-ol C4H10O + C4H10O 2-Methylpropan-2-ol (VMSD1211, LB4536_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Butan-2-ol C4H10O + C4H10O 2-Methylpropan-2-ol (VMSD1211, LB4536_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  12. Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C7H5N Benzonitrile (VMSD1212, LB4249_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C7H5N Benzonitrile (VMSD1212, LB4249_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  13. Volumetric Properties of the Mixture N,N-Dimethylethanamide C4H9NO + C4H10O 2-Methylpropan-2-ol (VMSD1212, LB3723_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture N,N-Dimethylethanamide C4H9NO + C4H10O 2-Methylpropan-2-ol (VMSD1212, LB3723_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  14. Volumetric Properties of the Mixture Nitroethane C2H5NO2 + C4H10O 2-Methylpropan-2-ol (VMSD1111, LB4022_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Nitroethane C2H5NO2 + C4H10O 2-Methylpropan-2-ol (VMSD1111, LB4022_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  15. Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C7H5N Benzonitrile (VMSD1111, LB4243_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C7H5N Benzonitrile (VMSD1111, LB4243_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  16. Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C7H8 Toluene (VMSD1212, LB4110_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C7H8 Toluene (VMSD1212, LB4110_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  17. Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C7H8O Methyl phenyl ether (VMSD1111, LB4970_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C7H8O Methyl phenyl ether (VMSD1111, LB4970_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  18. Volumetric Properties of the Mixture Butanenitrile C4H7N + C4H10O 2-Methylpropan-2-ol (VMSD1111, LB4087_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Butanenitrile C4H7N + C4H10O 2-Methylpropan-2-ol (VMSD1111, LB4087_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  19. Volumetric Properties of the Mixture Water H2O + C4H10O 2-Methylpropan-2-ol (VMSD1111, LB4195_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume A 'Binary Liquid Systems of Nonelectrolytes I' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Water H2O + C4H10O 2-Methylpropan-2-ol (VMSD1111, LB4195_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  20. Volumetric Properties of the Mixture Butan-2-one C4H8O + C4H10O 2-Methylpropan-2-ol (VMSD1211, LB3990_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Butan-2-one C4H8O + C4H10O 2-Methylpropan-2-ol (VMSD1211, LB3990_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  1. Volumetric Properties of the Mixture Nitroethane C2H5NO2 + C4H10O 2-Methylpropan-2-ol (VMSD1212, LB4023_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Nitroethane C2H5NO2 + C4H10O 2-Methylpropan-2-ol (VMSD1212, LB4023_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  2. Volumetric Properties of the Mixture 2-Methylpropan-1-ol C4H10O + C4H10O 2-Methylpropan-2-ol (VMSD1211, LB4537_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture 2-Methylpropan-1-ol C4H10O + C4H10O 2-Methylpropan-2-ol (VMSD1211, LB4537_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  3. Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C6H7N 4-Methylpyridine (VMSD1111, LB4995_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C6H7N 4-Methylpyridine (VMSD1111, LB4995_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  4. Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C6H6 Benzene (VMSD1212, LB4186_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C6H6 Benzene (VMSD1212, LB4186_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  5. Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C6H6 Benzene (VMSD1111, LB4185_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C6H6 Benzene (VMSD1111, LB4185_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  6. Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C6H7N 4-Methylpyridine (VMSD1212, LB5001_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C6H7N 4-Methylpyridine (VMSD1212, LB5001_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  7. Volumetric Properties of the Mixture Butanenitrile C4H7N + C4H10O 2-Methylpropan-2-ol (VMSD1212, LB4090_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Butanenitrile C4H7N + C4H10O 2-Methylpropan-2-ol (VMSD1212, LB4090_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  8. Volumetric Properties of the Mixture Butan-1-ol C4H10O + C4H10O 2-Methylpropan-2-ol (VMSD1211, LB4535_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Butan-1-ol C4H10O + C4H10O 2-Methylpropan-2-ol (VMSD1211, LB4535_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  9. Volumetric Properties of the Mixture Water H2O + C4H10O 2-Methylpropan-2-ol (VMSD1212, LB4197_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume A 'Binary Liquid Systems of Nonelectrolytes I' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Water H2O + C4H10O 2-Methylpropan-2-ol (VMSD1212, LB4197_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  10. Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C7H8 Toluene (VMSD1111, LB4104_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C7H8 Toluene (VMSD1111, LB4104_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  11. Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C7H8O Methyl phenyl ether (VMSD1212, LB4973_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C7H8O Methyl phenyl ether (VMSD1212, LB4973_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  12. Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C4H11N tert-Butylamine (VMSD1211, LB4187_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C4H11N tert-Butylamine (VMSD1211, LB4187_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  13. Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C6H14 Hexane (VMSD1211, LB4540_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C6H14 Hexane (VMSD1211, LB4540_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  14. Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C6H14O Dipropyl ether (VMSD1211, LB3998_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture 2-Methylpropan-2-ol C4H10O + C6H14O Dipropyl ether (VMSD1211, LB3998_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  15. Volumetric Properties of the Mixture N,N-Dimethylethanamide C4H9NO + C4H10O 2-Methylpropan-2-ol (VMSD1111, LB3726_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture N,N-Dimethylethanamide C4H9NO + C4H10O 2-Methylpropan-2-ol (VMSD1111, LB3726_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  16. Volumetric Properties of the Mixture Hex-1-ene C6H12 + C10H12 1,2,3,4-Tetrahydronaphthalene (VMSD1211, LB3980_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Hex-1-ene C6H12 + C10H12 1,2,3,4-Tetrahydronaphthalene (VMSD1211, LB3980_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  17. Volumetric Properties of the Mixture Cyclohexane C6H12 + C8H18O Dibutyl ether (VMSD1111, LB4006_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C8H18O Dibutyl ether (VMSD1111, LB4006_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  18. Volumetric Properties of the Mixture Nitrobenzene C6H5NO2 + C6H12 Cyclohexane (VMSD1212, LB3420_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Nitrobenzene C6H5NO2 + C6H12 Cyclohexane (VMSD1212, LB3420_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  19. Volumetric Properties of the Mixture Cyclohexane C6H12 + C10H18 cis-Bicyclo[4.4.0]decane (VMSD1111, LB3901_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C10H18 cis-Bicyclo[4.4.0]decane (VMSD1111, LB3901_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  20. Volumetric Properties of the Mixture Cyclohexane C6H12 + C8H19N Dibutylamine (VMSD1212, LB3457_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C8H19N Dibutylamine (VMSD1212, LB3457_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  1. Volumetric Properties of the Mixture Cyclohexane C6H12 + C7H16O3 Triethoxymethane (VMSD1111, LB3203_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C7H16O3 Triethoxymethane (VMSD1111, LB3203_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  2. Volumetric Properties of the Mixture Cyclohexane C6H12 + C6H15N Dipropylamine (VMSD1111, LB3520_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C6H15N Dipropylamine (VMSD1111, LB3520_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  3. Volumetric Properties of the Mixture Diethylamine C4H11N + C6H12 Cyclohexane (VMSD1212, LB3450_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Diethylamine C4H11N + C6H12 Cyclohexane (VMSD1212, LB3450_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  4. Volumetric Properties of the Mixture Cyclohexane C6H12 + C7H8O Methyl phenyl ether (VMSD1511, LB4558_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C7H8O Methyl phenyl ether (VMSD1511, LB4558_V)' providing data from direct measurement of low-pressure thermodynamic speed of sound at variable mole fraction and constant temperature, in the single-phase region(s).

  5. Volumetric Properties of the Mixture 1,1,2,2-Tetrachloroethane C2H2Cl4 + C6H12 Cyclohexane (VMSD1211, LB4404_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture 1,1,2,2-Tetrachloroethane C2H2Cl4 + C6H12 Cyclohexane (VMSD1211, LB4404_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  6. Volumetric Properties of the Mixture Cyclohexane C6H12 + C8H19N Dibutylamine (VMSD1111, LB3494_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C8H19N Dibutylamine (VMSD1111, LB3494_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  7. Volumetric Properties of the Mixture Cyclohexane C6H12 + C12H27N Tributylamine (VMSD1111, LB3490_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C12H27N Tributylamine (VMSD1111, LB3490_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  8. Volumetric Properties of the Mixture Cyclohexane C6H12 + C10H18 cis-Bicyclo[4.4.0]decane (VMSD1212, LB3895_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C10H18 cis-Bicyclo[4.4.0]decane (VMSD1212, LB3895_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  9. Volumetric Properties of the Mixture Cyclohexane C6H12 + C10H18 trans-Bicyclo[4.4.0]decane (VMSD1212, LB3896_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C10H18 trans-Bicyclo[4.4.0]decane (VMSD1212, LB3896_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  10. Volumetric Properties of the Mixture Cyclohexane C6H12 + C6H15N Triethylamine (VMSD1212, LB3445_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C6H15N Triethylamine (VMSD1212, LB3445_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  11. Volumetric Properties of the Mixture 1,3-Dioxane C4H8O2 + C6H12 Cyclohexane (VMSD1111, LB5124_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture 1,3-Dioxane C4H8O2 + C6H12 Cyclohexane (VMSD1111, LB5124_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  12. Volumetric Properties of the Mixture Cyclohexane C6H12 + C7H8O Methyl phenyl ether (VMSD1412, LB4564_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C7H8O Methyl phenyl ether (VMSD1412, LB4564_V)' providing data by calculation of isentropic compressibility from low-pressure density and thermodynamic speed of sound data at variable mole fraction and constant temperature, in the single-phase region(s).

  13. Volumetric Properties of the Mixture N-Methylethanamide C3H7NO + C6H12 Cyclohexane (VMSD1211, LB4399_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture N-Methylethanamide C3H7NO + C6H12 Cyclohexane (VMSD1211, LB4399_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  14. Volumetric Properties of the Mixture Bromobenzene C6H5Br + C6H12 Cyclohexane (VMSD1111, LB3734_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Bromobenzene C6H5Br + C6H12 Cyclohexane (VMSD1111, LB3734_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  15. Volumetric Properties of the Mixture 1,3-Dioxane C4H8O2 + C6H12 Cyclohexane (VMSD1511, LB5121_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture 1,3-Dioxane C4H8O2 + C6H12 Cyclohexane (VMSD1511, LB5121_V)' providing data from direct measurement of low-pressure thermodynamic speed of sound at variable mole fraction and constant temperature, in the single-phase region(s).

  16. Volumetric Properties of the Mixture Cyclohexane C6H12 + C10H12 1,2,3,4-Tetrahydronaphthalene (VMSD1212, LB3848_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C10H12 1,2,3,4-Tetrahydronaphthalene (VMSD1212, LB3848_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  17. Volumetric Properties of the Mixture Nitrobenzene C6H5NO2 + C6H12 Cyclohexane (VMSD1111, LB3157_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Nitrobenzene C6H5NO2 + C6H12 Cyclohexane (VMSD1111, LB3157_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  18. Volumetric Properties of the Mixture Cyclohexane C6H12 + C6H14O Diisopropyl ether (VMSD1112, LB3862_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C6H14O Diisopropyl ether (VMSD1112, LB3862_V)' providing data by calculation of mass density in the single-phase region(s) from low-pressure dilatometric measurements of the molar excess volume at variable mole fraction and constant temperature.

  19. Volumetric Properties of the Mixture Oxolane C4H8O + C6H12 Cyclohexane (VMSD1212, LB3617_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Oxolane C4H8O + C6H12 Cyclohexane (VMSD1212, LB3617_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  20. Volumetric Properties of the Mixture Cyclohexane C6H12 + C8H18O Dibutyl ether (VMSD1212, LB4004_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C8H18O Dibutyl ether (VMSD1212, LB4004_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  1. Volumetric Properties of the Mixture Cyclohexane C6H12 + C8H10 1,3-Dimethylbenzene (VMSD1111, LB3592_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C8H10 1,3-Dimethylbenzene (VMSD1111, LB3592_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  2. Volumetric Properties of the Mixture Bromobenzene C6H5Br + C6H12 Cyclohexane (VMSD1212, LB3251_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Bromobenzene C6H5Br + C6H12 Cyclohexane (VMSD1212, LB3251_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  3. Volumetric Properties of the Mixture Cyclohexane C6H12 + C6H14O Diisopropyl ether (VMSD1211, LB3553_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C6H14O Diisopropyl ether (VMSD1211, LB3553_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  4. Volumetric Properties of the Mixture Cyclohexane C6H12 + C6H14O Hexan-1-ol (VMSD1212, LB4546_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C6H14O Hexan-1-ol (VMSD1212, LB4546_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  5. Volumetric Properties of the Mixture Nitrobenzene C6H5NO2 + C6H12 Cyclohexane (VMSD1111, LB3475_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Nitrobenzene C6H5NO2 + C6H12 Cyclohexane (VMSD1111, LB3475_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  6. Volumetric Properties of the Mixture Cyclohexane C6H12 + C9H21N Tripropylamine (VMSD1111, LB3491_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C9H21N Tripropylamine (VMSD1111, LB3491_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  7. Volumetric Properties of the Mixture Diethylamine C4H11N + C6H12 Cyclohexane (VMSD1111, LB3472_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Diethylamine C4H11N + C6H12 Cyclohexane (VMSD1111, LB3472_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  8. Volumetric Properties of the Mixture Cyclohexane C6H12 + C9H21N Tripropylamine (VMSD1212, LB3437_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C9H21N Tripropylamine (VMSD1212, LB3437_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  9. Volumetric Properties of the Mixture Cyclohexane C6H12 + C6H14O Diisopropyl ether (VMSD1211, LB3859_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C6H14O Diisopropyl ether (VMSD1211, LB3859_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  10. Volumetric Properties of the Mixture Hex-1-ene C6H12 + C8H10 1,2-Dimethylbenzene (VMSD1212, LB4577_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Hex-1-ene C6H12 + C8H10 1,2-Dimethylbenzene (VMSD1212, LB4577_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  11. Volumetric Properties of the Mixture Oxane C5H10O + C6H12 Cyclohexane (VMSD1111, LB3587_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Oxane C5H10O + C6H12 Cyclohexane (VMSD1111, LB3587_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  12. Volumetric Properties of the Mixture Oxane C5H10O + C6H12 Cyclohexane (VMSD1212, LB3588_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Oxane C5H10O + C6H12 Cyclohexane (VMSD1212, LB3588_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  13. Volumetric Properties of the Mixture Cyclohexane C6H12 + C6H15N Triethylamine (VMSD1111, LB3514_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C6H15N Triethylamine (VMSD1111, LB3514_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  14. Volumetric Properties of the Mixture Hex-1-ene C6H12 + C8H10 1,2-Dimethylbenzene (VMSD1111, LB5004_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Hex-1-ene C6H12 + C8H10 1,2-Dimethylbenzene (VMSD1111, LB5004_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  15. Volumetric Properties of the Mixture Cyclohexane C6H12 + C7H16O3 Triethoxymethane (VMSD1212, LB3206_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C7H16O3 Triethoxymethane (VMSD1212, LB3206_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  16. Volumetric Properties of the Mixture 1,3-Dioxane C4H8O2 + C6H12 Cyclohexane (VMSD1212, LB5126_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture 1,3-Dioxane C4H8O2 + C6H12 Cyclohexane (VMSD1212, LB5126_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  17. Volumetric Properties of the Mixture Cyclohexane C6H12 + C6H15N Dipropylamine (VMSD1212, LB3462_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C6H15N Dipropylamine (VMSD1212, LB3462_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  18. Volumetric Properties of the Mixture Hex-1-ene C6H12 + C12H16 Cyclohexylbenzene (VMSD1211, LB3987_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Hex-1-ene C6H12 + C12H16 Cyclohexylbenzene (VMSD1211, LB3987_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  19. Volumetric Properties of the Mixture Cyclohexane C6H12 + C8H10 1,3-Dimethylbenzene (VMSD1212, LB3593_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C8H10 1,3-Dimethylbenzene (VMSD1212, LB3593_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  20. Volumetric Properties of the Mixture Cyclohexane C6H12 + C12H27N Tributylamine (VMSD1212, LB3438_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C12H27N Tributylamine (VMSD1212, LB3438_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  1. Volumetric Properties of the Mixture Cyclohexane C6H12 + C10H18 trans-Bicyclo[4.4.0]decane (VMSD1111, LB3902_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexane C6H12 + C10H18 trans-Bicyclo[4.4.0]decane (VMSD1111, LB3902_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  2. Volumetric Properties of the Mixture Butylamine C4H11N + C6H12 Cyclohexane (VMSD1111, LB3469_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Butylamine C4H11N + C6H12 Cyclohexane (VMSD1111, LB3469_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  3. Volumetric Properties of the Mixture Butylamine C4H11N + C6H12 Cyclohexane (VMSD1212, LB3467_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Butylamine C4H11N + C6H12 Cyclohexane (VMSD1212, LB3467_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  4. Propagation of a laser beam in a time-varying waveguide. [plasma heating for controlled fusion

    Science.gov (United States)

    Chapman, J. M.; Kevorkian, J.

    1978-01-01

    The propagation of an axisymmetric laser beam in a plasma column having a radially parabolic electron density distribution is reported. For the case of an axially uniform waveguide it is found that the basic characteristics of alternating focusing and defocusing beams are maintained. However, the intensity distribution is changed at the foci and outer-beam regions. The features of paraxial beam propagation are discussed with reference to axially varying waveguides. Laser plasma coupling is considered noting the case where laser heating produces a density distribution radially parabolic near the axis and the energy absorbed over the focal length of the plasma is small. It is found that: (1) beam-propagation stability is governed by the relative magnitude of the density fluctuations existing in the axial variation of the waveguides due to laser heating, and (2) for beam propagation in a time-varying waveguide, the global instability of the propagation is a function of the initial fluctuation growth rate as compared to the initial time rate of change in the radial curvature of the waveguide.

  5. Divertor Heat Flux Control with 3D Stochastic Magnetic Fields during ELM Suppression

    Science.gov (United States)

    Orlov, Dm; Moyer, Ra; Bykov, Io; Evans, Te; Wu, W.; Loarte, A.; Teklu, A.; Watkins, Jg; Wang, H.; Lyons, Bc; Trevisan, Gl; Makowski, Ma; Lasnier, C.; Fenstermacher, Me

    2017-10-01

    Experiments in DIII-D have been performed to modify the divertor heat and particle flux pattern during suppression of ELMs with resonant magnetic perturbation (RMP) fields. In this work, we assessed the impact of small current modulations in a subset of DIII-D I-coils on pedestal profiles, transport and stability as well as divertor conditions. Different I-coil subset ramps were performed allowing for a slow transition of the divertor footprints from n =3 to n =2 and n =1 distributions. We obtained long periods of RMP ELM suppression with slow I-coil quartet ramps. Strong divertor particle flux splitting was observed in these discharges as well as modulation of the divertor heat flux due to changes in toroidal spectrum of applied perturbation. Experimental results are compared to the TRIP3D modeling and to linear M3D-C1 simulations to understand the role of the plasma response on quantitative predictions of the divertor flux splitting. Work supported by US DOE under DE-FC02-04ER54698 and DE-FG02-05ER54809.

  6. Calculation of physiologic dead space: comparison of ventilator volumetric capnography to measurements by metabolic analyzer and volumetric CO2 monitor.

    Science.gov (United States)

    Siobal, Mark S; Ong, Hannah; Valdes, Josephine; Tang, Julin

    2013-07-01

    Calculation of physiologic dead space (dead space divided by tidal volume [VD/VT]) using the Enghoff modification of the Bohr equation requires measurement of the partial pressure of mean expired CO2 (PĒCO2) by exhaled gas collection and analysis, use of a metabolic analyzer, or use of a volumetric CO2 monitor. The Dräger XL ventilator is equipped with integrated volumetric CO2 monitoring and calculates minute CO2 production (VCO2). We calculated PĒCO2 and VD/VT from ventilator derived volumetric CO2 measurements of VCO2 and compared them to metabolic analyzer and volumetric CO2 monitor measurements. A total of 67 measurements in 36 subjects recovering from acute lung injury or ARDS were compared. Thirty-one ventilator derived measurements were compared to measurements using 3 different metabolic analyzers, and 36 ventilator derived measurements were compared to measurements from a volumetric CO2 monitor. There was a strong agreement between ventilator derived measurements and metabolic analyzer or volumetric CO2 monitor measurements of PĒCO2 and VD/VT. The correlations, bias, and precision between the ventilator and metabolic analyzer measurements for PĒCO2 were r = 0.97, r(2) = 0.93 (P monitor for PĒCO2 were r = 0.96 and r(2) = 0.92 (P monitor for VD/VT were r = 0.97 and r(2) = 0.95 (P monitor.

  7. Volumetric Velocity Measurements of Pulsating Flow through a Model Aneurysm

    Science.gov (United States)

    Troolin, Daniel; Amatya, Devesh; Longmire, Ellen

    2010-11-01

    Volumetric 3-component velocimetry (V3V) was used to examine the flow structure inside of a scaled-up transparent urethane model of a saccular aneurysm. The model was fabricated to match the geometry of an in vivo case. Index matching was used to minimize optical distortions caused by the curved walls of the model. The model and a surrounding visualization box were integrated into a custom-built pulse duplicator system with in-line flow meter and pressure transducers. The pulsing frequency and amplitude were controlled independently to generate two flow conditions each having a non-dimensional peak Reynolds (Re) and Womersley (Wo) Number: Re = 250, Wo = 10.4 and Re = 125, Wo = 7.4. Phase-locked and instantaneous measurements of the pulsatile flow upstream, downstream, and within the aneurysm reveal significant three-dimensional features including zones of separation, recirculation, impingement, and relative inactivity. Plots and movies will be shown, and a detailed discussion of the flow and various experimental considerations will be included.

  8. Volumetric associations between uncinate fasciculus, amygdala, and trait anxiety

    Directory of Open Access Journals (Sweden)

    Baur Volker

    2012-01-01

    Full Text Available Abstract Background Recent investigations of white matter (WM connectivity suggest an important role of the uncinate fasciculus (UF, connecting anterior temporal areas including the amygdala with prefrontal-/orbitofrontal cortices, for anxiety-related processes. Volume of the UF, however, has rarely been investigated, but may be an important measure of structural connectivity underlying limbic neuronal circuits associated with anxiety. Since UF volumetric measures are newly applied measures, it is necessary to cross-validate them using further neural and behavioral indicators of anxiety. Results In a group of 32 subjects not reporting any history of psychiatric disorders, we identified a negative correlation between left UF volume and trait anxiety, a finding that is in line with previous results. On the other hand, volume of the left amygdala, which is strongly connected with the UF, was positively correlated with trait anxiety. In addition, volumes of the left UF and left amygdala were inversely associated. Conclusions The present study emphasizes the role of the left UF as candidate WM fiber bundle associated with anxiety-related processes and suggests that fiber bundle volume is a WM measure of particular interest. Moreover, these results substantiate the structural relatedness of UF and amygdala by a non-invasive imaging method. The UF-amygdala complex may be pivotal for the control of trait anxiety.

  9. Effects of Heating on Teflon(Registered Trademark) FEP Thermal Control Material from the Hubble Space Telescope

    Science.gov (United States)

    deGroh, Kim; Gaier, James R.; Hall, Rachelle L.; Norris, Mary Jo; Espe, Matthew P.; Cato, Daveen R.

    1999-01-01

    Metallized Teflon(Registered Trademark) FEP (fluorinated ethylene propylene) thermal control material on the Hubble Space Telescope (HST) is degrading in the space environment. Teflon(Registered Trademark) FEP thermal control blankets (space-facing FEP) retrieved during the first servicing mission (SM1) were found to be embrittled on solar facing surfaces and contained microscopic cracks. During the second servicing mission (SM2) astronauts noticed that the FEP outer layer of the multi-layer insulation (MLI) covering the telescope was cracked in many locations around the telescope. Large cracks were observed on the light shield, forward shell and equipment bays. A tightly curled piece of cracked FEP from the light shield was retrieved during SM2 and was severely embrittled, as witnessed by ground testing. A Failure Review Board (FRB) was organized to determine the mechanism causing the MLI degradation. Density, x-ray crystallinity and solid state nuclear magnetic resonance (NMR) analyses of FEP retrieved during SM1 were inconsistent with results of FEP retrieved during SM2. Because the retrieved SM2 material curled while in space, it experienced a higher temperature extreme during thermal cycling, estimated at 200 C, than the SM1 material, estimated at 50 C. An investigation on the effects of heating pristine and FEP exposed on HST was therefore conducted. Samples of pristine. SM1, and SM2 FEP were heated to 200 C and evaluated for changes in density and morphology. Elevated temperature exposure was found to have a major impact on the density of the retrieved materials. Characterization of polymer morphology of as-received and heated FEP samples by NMR provided results that were consistent with the density results. These findings have provided insight to the damage mechanisms of FEP in the space environment.

  10. Control system pre-feedbacked for the super heated steam temperature in heat recovering units; Sistema de control pre-retroalimentado para la temperatura de vapor sobrecalentado en recuperadores de calor

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Alvarez, Hilario; Madrigal Espinosa, Guadalupe [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    The study that is presented corresponds to the analysis, design and development of a pre-feedbacked control system for the superheated steam temperature regulation in the heat recovery units of a combined cycle thermoelectric power plant. The designs of the feedback controller and the pre-feedback control system were implemented based in a linear model of the tempering zone. This linear model was obtained through the application of parametric identification techniques to the non-linear mathematical model of a combined cycle power plant. [Espanol] El estudio que se presenta corresponde al analisis, diseno y desarrollo de un sistema de control pre-retroalimentado para regular la temperatura de vapor sobrecalentado en los recuperadores de calor de una central termoelectrica de ciclo combinado. Los disenos del controlador retroalimentado y del sistema de control prealimentado se realizaron con base en un modelo lineal de la zona de atemperacion. Este modelo lineal se obtuvo aplicando tecnicas de identificacion parametrica al modelo matematico no-lineal de una central de ciclo combinado.

  11. The membrane-associated transient receptor potential vanilloid channel is the central heat shock receptor controlling the cellular heat shock response in epithelial cells.

    Directory of Open Access Journals (Sweden)

    Zohar Bromberg

    Full Text Available The heat shock response (HSR is a highly conserved molecular response to various types of stresses, including heat shock, during which heat-shock proteins (Hsps are produced to prevent and repair damages in labile proteins and membranes. In cells, protein unfolding in the cytoplasm is thought to directly enable the activation of the heat shock factor 1 (HSF-1, however, recent work supports the activation of the HSR via an increase in the fluidity of specific membrane domains, leading to activation of heat-shock genes. Our findings support the existence of a plasma membrane-dependent mechanism of HSF-1 activation in animal cells, which is initiated by a membrane-associated transient receptor potential vanilloid receptor (TRPV. We found in various non-cancerous and cancerous mammalian epithelial cells that the TRPV1 agonists, capsaicin and resiniferatoxin (RTX, upregulated the accumulation of Hsp70, Hsp90 and Hsp27 and Hsp70 and Hsp90 respectively, while the TRPV1 antagonists, capsazepine and AMG-9810, attenuated the accumulation of Hsp70, Hsp90 and Hsp27 and Hsp70, Hsp90, respectively. Capsaicin was also shown to activate HSF-1. These findings suggest that heat-sensing and signaling in mammalian cells is dependent on TRPV channels in the plasma membrane. Thus, TRPV channels may be important drug targets to inhibit or restore the cellular stress response in diseases with defective cellular proteins, such as cancer, inflammation and aging.

  12. Energy savings and economics of advanced control strategies for packaged air conditioners with gas heat

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Weimin; Katipamula, Srinivas; Huang, Yunzhi; Brambley, Michael R.

    2013-10-01

    This paper presents an evaluation of the potential energy savings from adding advanced control to existing packaged air conditioners. Advanced control options include air-side economizer, multi-speed fan control, demand control ventilation and staged cooling. The energy and cost savings from the different control strategies individually and in combination are estimated using the EnergyPlus detailed energy simulation program for four building types, namely, a small office building, a stand-alone retail building, a strip mall building and a supermarket building. For each of the four building types, the simulation was run for 16 locations covering all 15 climate zones in the U.S. The maximum installed cost of a replacement controller that provides acceptable payback periods to owners is estimated.

  13. Controlling the heat release in HCCI combustion of DME with methanol and EGR

    DEFF Research Database (Denmark)

    Pedersen, Troels Dyhr; Schramm, Jesper; Yanai, Tadanori

    2010-01-01

    , by advancing the injection timing 360 CAD, as an HCCI engine. The compression ratio of the engine was reduced to 14.5 by enlarging the piston bowls. The engine was operated in HCCI mode with DME at an equivalence ratio of 0.25. To retard the combustion timing, methanol was port fuel injected and the optimum......The effects of methanol and EGR on HCCI combustion of dimethyl ether have been tested separately in a diesel engine. The engine was equipped with a common rail injection system which allowed for random injection of DME. The engine could therefore be operated either as a normal DI CI engine or...... quantity required was determined. The added methanol increased the BMEP by increasing the total heat release and retarding the combustion to after TDC. Engine knock was reduced with increasing quantities of methanol. The highest BMEP was achieved when the equivalence ratio of methanol was around 0...

  14. Development of latent fingerprints on thermal paper by the controlled application of heat.

    Science.gov (United States)

    Bond, John W

    2013-05-01

    Apparatus to produce a spatially and temporally uniform heat source is described and this is used to visualize latent fingerprints deposited onto thermal paper by raising the temperature of the paper. Results show an improvement over previous research when fingerprint deposits are aged or the developed fingerprints faint; visualization being enhanced by the use of a blue LED light source of 465 nm peak wavelength. An investigation of the components in fingerprint sweat likely to affect the solubility and hence color change of the dye present in the thermal paper has shown that polar protic solvents able to donate a proton are favored and a polar amino acid found commonly in eccrine fingerprint sweat (lysine) has been shown able to produce the desired color change. Aged fingerprint deposits on thermal paper from a variety of sources up to 4 years old have been visualized with this technique. © 2013 American Academy of Forensic Sciences.

  15. Waste Heat to Power Market Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Elson, Amelia [ICF International, Fairfax, VA (United States); Tidball, Rick [ICF International, Fairfax, VA (United States); Hampson, Anne [ICF International, Fairfax, VA (United States)

    2015-03-01

    Waste heat to power (WHP) is the process of capturing heat discarded by an existing process and using that heat to generate electricity. In the industrial sector, waste heat streams are generated by kilns, furnaces, ovens, turbines, engines, and other equipment. In addition to processes at industrial plants, waste heat streams suitable for WHP are generated at field locations, including landfills, compressor stations, and mining sites. Waste heat streams are also produced in the residential and commercial sectors, but compared to industrial sites these waste heat streams typically have lower temperatures and much lower volumetric flow rates. The economic feasibility for WHP declines as the temperature and flow rate decline, and most WHP technologies are therefore applied in industrial markets where waste heat stream characteristics are more favorable. This report provides an assessment of the potential market for WHP in the industrial sector in the United States.

  16. Bayesian fuzzy logic-based estimation of electron cyclotron heating (ECH) power deposition in MHD control systems

    Energy Technology Data Exchange (ETDEWEB)

    Davoudi, Mehdi, E-mail: mehdi.davoudi@polimi.it [Department of Electrical and Computer Engineering, Buein Zahra Technical University, Buein Zahra, Qazvin (Iran, Islamic Republic of); Davoudi, Mohsen, E-mail: davoudi@eng.ikiu.ac.ir [Department of Electrical Engineering, Imam Khomeini International University, Qazvin, 34148-96818 (Iran, Islamic Republic of)

    2017-06-15

    Highlights: • A couple of algorithms to diagnose if Electron Cyclotron Heating (ECH) power is deposited properly on the expected deposition minor radius are proposed. • The algorithms are based on Bayesian theory and Fuzzy logic. • The algorithms are tested on the off-line experimental data acquired from Frascati Tokamak Upgrade (FTU), Frascati, Italy. • Uncertainties and evidences derived from the combination of online information formed by the measured diagnostic data and the prior information are also estimated. - Abstract: In the thermonuclear fusion systems, the new plasma control systems use some measured on-line information acquired from different sensors and prior information obtained by predictive plasma models in order to stabilize magnetic hydro dynamics (MHD) activity in a tokamak. Suppression of plasma instabilities is a key issue to improve the confinement time of controlled thermonuclear fusion with tokamaks. This paper proposes a couple of algorithms based on Bayesian theory and Fuzzy logic to diagnose if Electron Cyclotron Heating (ECH) power is deposited properly on the expected deposition minor radius (r{sub DEP}). Both algorithms also estimate uncertainties and evidences derived from the combination of the online information formed by the measured diagnostic data and the prior information. The algorithms have been employed on a set of off-line ECE channels data which have been acquired from the experimental shot number 21364 at Frascati Tokamak Upgrade (FTU), Frascati, Italy.

  17. Fabrication of Hollow Silica Microspheres with Orderly Hemispherical Protrusions and Capability for Heat-Induced Controlled Cracking.

    Science.gov (United States)

    Takafuji, Makoto; Hano, Nanami; Alam, Md A; Ihara, Hirotaka

    2017-10-10

    Hollow silica microspheres with orderly protrusions on their outer and inner surfaces were fabricated in three simple steps: (1) suspension polymerization of a polymerizable monomer containing silica nanoparticles to obtain polymeric microspheres with a layered shell of silica particles; (2) sol-gel reaction of tetraethoxysilane (TEOS) on the surface of the microspheres to connect the silica nanoparticles; (3) removal of polymer core by calcination. The shell composed of silica-connected silica nanoparticles remained spherical even after calcination, and the characteristic surface morphology with protrusions were obtained on both inner and outer surfaces. Measurements of the mechanical strength revealed that the compression modulus of the hollow microspheres increased with increasing thickness of the silica layer, which could be controlled by changing the concentration of TEOS in the sol-gel reaction. Rapid heating of the hollow silica microspheres with the thin silica-connected layer led to silica shell cracking, and the cracks were mostly observed in the connecting layer between the silica nanoparticles. The stress was probably concentrated in the connecting layer because of its lower thickness than the nanoparticles. Such characteristic of the hollow microspheres is useful for a capsule with capability for heat-induced controlled cracking caused by internal pressure changes.

  18. Optimal operation and stabilising control of the concentric heat-integrated distillation column (HIDiC)

    DEFF Research Database (Denmark)

    Bisgaard, Thomas; Skogestad, Sigurd; Abildskov, Jens

    2017-01-01

    This paper presents the application of a systematic control configuration design procedure on the HIDiC with a reboiler. The application is illustrated through two case studies of industrial relevance, namely the separation of benzene/toluene and a multicomponent mixture of aromatic compounds. Re...... by controlling both column section pressures and the temperature profile in one of the sections, while the economic variables are controlled by cascade control loops. Guidelines for the design of both the regulatory control layer and the supervisory control layer are provided.......This paper presents the application of a systematic control configuration design procedure on the HIDiC with a reboiler. The application is illustrated through two case studies of industrial relevance, namely the separation of benzene/toluene and a multicomponent mixture of aromatic compounds....... Results of static optimisations and dynamic simulations are presented based on a realistic column model, which accounts for dynamic pressure drops and liquid holdups, dynamic energy balances and more. Using a decentralised control scheme, good stabilising and economic performance are achieved...

  19. Hierarchical Control Strategy of Heat and Power for Zero Energy Buildings including Hybrid Fuel Cell/Photovoltaic Power Sources and Plug-in Electric Vehicle

    DEFF Research Database (Denmark)

    Ghiasi, Mohammad Iman; Aliakbar Golkar, Masoud; Hajizadeh, Amin

    2016-01-01

    complexities and uncertainties in this kind of hybrid system, a hybrid supervisory control with an adaptive fuzzy sliding power control strategy is proposed to regulate the amount of requested fuel from a fuel cell power source to produce the electrical power and heat. Then, simulation results are used......This paper presents a hierarchical control strategy for heat and electric power control of a building integrating hybrid renewable power sources including photovoltaic, fuel cell and battery energy storage with Plug-in Electric Vehicles (PEV) in smart distribution systems. Because...... of the controllability of fuel cell power, this power sources plays the main role for providing heat and electric power to zero emission buildings. First, the power flow structure between hybrid power resources is described. To do so, all necessary electrical and thermal equations are investigated. Next, due to the many...

  20. Specimen size effect in the volumetric shrinkage of cancellous bone measured at two levels of dehydration.

    Science.gov (United States)

    Lievers, W Brent; Lee, Victoria; Arsenault, Simon M; Waldman, Stephen D; Pilkey, A Keith

    2007-01-01

    Water is commonly removed from bone to study its effect on mechanical behaviour; however, dehydration also alters the bone structure. To make matters worse, measuring structural changes in cancellous bone is complicated by a number of factors. Therefore, the goals of this study were to address these issues by (1) comparing Archimedes' method and a helium pycnometer as methods for measuring cancellous bone volume; (2) measuring the apparent dimensional and volumetric tissue shrinkage of cancellous bone at two levels of dehydration; and, (3) identifying whether a size effect exists in cancellous bone shrinkage. Cylindrical specimens (3, 5 and 8.3 mm diameters) of cancellous bone were taken from the distal bovine femur. The apparent dimensions of each cylindrical specimen were measured in a fully hydrated state (HYD), after drying at room temperature (AIR), and after oven drying at 105 degrees C (OVEN). Tissue volume measurements for those three hydration states were obtained using both a helium pycnometer and Archimedes' method. Aluminium foams, which mimic the cancellous structure, were used as controls. The results suggest that the helium pycnometer and Archimedes' method yield identical results in the HYD and AIR states, but that Archimedes' method under-predicts the nominal OVEN volume by incorporating the collagen-apatite porosity. A distinct size effect on volumetric shrinkage is observed (pshrinkage (2% and 7%) at the two dehydration levels is much smaller than the measured volumetric tissue shrinkage (16% and 29%), which results in a reduced dehydrated bone volume fraction.

  1. Volumetric assessment of optic nerve sheath and hypophysis in idiopathic intracranial hypertension.

    Science.gov (United States)

    Hoffmann, J; Schmidt, C; Kunte, H; Klingebiel, R; Harms, L; Huppertz, H-J; Lüdemann, L; Wiener, E

    2014-03-01

    Idiopathic intracranial hypertension is a headache syndrome characterized by increased CSF pressure. Compression of the hypophysis and distension of the optic nerve sheath are reliable imaging signs. The purpose of the study was to validate, in patients with idiopathic intracranial hypertension, MR imaging-based volumetric measurements of the optic nerve sheath and hypophysis as an objective observation method for more accurate diagnosis and posttreatment follow-up. Twenty-three patients with idiopathic intracranial hypertension as well as age-, sex-, and body mass index-matched controls underwent volumetric measurements of the optic nerve, optic nerve sheath, and hypophysis on high-resolution T2-weighted MR images by using a 7-cm surface coil, followed by correlation with CSF opening pressures and clinical symptom scores of visual disturbances and headache. Mean values of optic nerve sheath (341.86 ± 163.69 mm(3) versus 127.56 ± 53.17 mm(3), P 201.30 mm(3) (sensitivity, 86.96%; specificity, 91.30%) and hypophysis volumes of intracranial hypertension diagnosis. In patients with idiopathic intracranial hypertension, no correlations were found between optic nerve sheath and hypophysis volumes and CSF opening pressures or clinical scores of visual disturbances and headache. Semiautomated volumetric measurement of optic nerve sheath and hypophysis has the potential to more accurately diagnose and follow patients with idiopathic intracranial hypertension.

  2. Species and quantity of airborne pollens in Shanghai as monitored by gravitational and volumetric methods.

    Science.gov (United States)

    Sun, Liying; Xu, Yanhua; Wang, Yiwei; Lou, Yueyan; Xu, Yiping; Guo, Yinshi

    2017-03-01

    The prevalence of allergic diseases has markedly increased in the last decades. It is therefore important to assess the distribution of airborne pollen, the most important aeroallergen, for allergic disease prevention and control. To identify the species and quantity of airborne pollens, and observe their distribution characteristics in Shanghai, using gravitational (Durham Sampler) and volumetric (Rotorod Sampler 40) methods simultaneously. In addition, the correlation between both methods was analyzed to provide effective preventive measures for pollen-sensitized individuals. Pollen counts were monitored in the same area from November 1, 2009 to October 31, 2010 by samplers set at the same height and site. Pollen concentrations as well as any association between the two methods were determined. Two pollen concentration peaks in Shanghai were observed from March to May (spring) and September to October (autumn). In spring, tree pollen was the main species, with a predominance of Broussonetia. In autumn, grass pollen predominated, with mostly Humulus. Thirty-two species were identified by both gravitational and volumetric methods. Five and seven additional species were identified exclusively by the gravitational and volumetric methods, respectively. Pollen counts obtained from both devices were significantly correlated (Ppollen counts in central urban Shanghai, showing two annual peaks. Broussonetia and Humulus were the predominant spring and autumn pollens, respectively. Pollen counts obtained by both methods were clearly correlated. Regional airborne pollen monitoring offers preventive measures for sensitized individuals and provides useful clinical information.

  3. Fatigue life estimation for different notched specimens based on the volumetric approach

    Science.gov (United States)

    Zehsaz, M.; Hassanifard, S.; Esmaeili, F.

    2010-06-01

    In this paper, the effects of notch radius for different notched specimens has been studied on the values of stress concentration factor, notch strength reduction factor, and fatigue life duration of the specimens. The material which has been selected for this investigation is Al 2024T3 . Volumetric approach has been applied to obtain the values of notch strength reduction factor and results have been compared with those obtained from the Neuber and Peterson methods. Load controlled fatigue tests of mentioned specimens have been conducted on the 250kN servo-hydraulic Zwick/Amsler fatigue testing machine with the frequency of 10Hz. The fatigue lives of the specimens have also been predicted based on the available smooth S-N curve of Al2024-T3 and also the amounts of notch strength reduction factor which have been obtained from volumetric, Neuber and Peterson methods. The values of stress and strain around the notch roots are required to predict the fatigue life of notched specimens, so Ansys finite element code has been used and non-linear analyses have been performed to obtain the stress and strain distributions around the notches. The plastic deformations of the material have been simulated using multi-linear kinematic hardening and cyclic stress-strain relation. The work here shows that the volumetric approach does a very good job for predicting the fatigue life of the notched specimens.

  4. Fatigue life estimation for different notched specimens based on the volumetric approach

    Directory of Open Access Journals (Sweden)

    Esmaeili F.

    2010-06-01

    Full Text Available In this paper, the effects of notch radius for different notched specimens has been studied on the values of stress concentration factor, notch strength reduction factor, and fatigue life duration of the specimens. The material which has been selected for this investigation is Al 2024T3 . Volumetric approach has been applied to obtain the values of notch strength reduction factor and results have been compared with those obtained from the Neuber and Peterson methods. Load controlled fatigue tests of mentioned specimens have been conducted on the 250kN servo-hydraulic Zwick/Amsler fatigue testing machine with the frequency of 10Hz. The fatigue lives of the specimens have also been predicted based on the available smooth S-N curve of Al2024-T3 and also the amounts of notch strength reduction factor which have been obtained from volumetric, Neuber and Peterson methods. The values of stress and strain around the notch roots are required to predict the fatigue life of notched specimens, so Ansys finite element code has been used and non-linear analyses have been performed to obtain the stress and strain distributions around the notches. The plastic deformations of the material have been simulated using multi-linear kinematic hardening and cyclic stress-strain relation. The work here shows that the volumetric approach does a very good job for predicting the fatigue life of the notched specimens.

  5. Stereotactic Radiosurgery of Central Skull Base Meningiomas-Volumetric Evaluation and Long-Term Outcomes.

    Science.gov (United States)

    Patibandla, Mohana Rao; Lee, Cheng-Chia; Sheehan, Jason

    2017-12-01

    Complete resection of a central skull base meningioma (CSM) is possible, but it is often associated with high morbidity. Stereotactic radiosurgery (SRS) plays an appreciable role in the management of skull base meningiomas. This study aims to apply volumetric methods to assess the CSM response after SRS and correlate it with clinical outcomes. The cohort consisted of 219 patients, of whom 73.9% were female (n = 162), with a median age of 55 years (19-88). SRS was the primary treatment for 45.7% (n = 100), while 37.9% (n = 83) underwent treatment for residual tumors, 14.2% (n = 31) for recurrence, and in 5 with others reasons. The median tumor volume was 4.9 cm 3 (0.3-105 cm 3 ) to a median margin dose of 14 Gy (5-35 Gy). Volumetric analysis of CSM was performed on the SRS scan and each available magnetic resonance image thereafter. The median clinical and imaging follow-ups of the cohort were 72 (24-298) and 66 (18-298) months, respectively. The overall tumor control rate was 83.4% (n = 183) at last follow-up with tumor regression 72.1% (n = 158). Neurologic symptoms were improved after SRS in 6.8% (n = 15), stable in 72.6% (n = 159), and worsened in 20.5% (n = 45). The clinical deterioration usually occurred in the patients with tumor progression (P < 0.001). Following SRS, the volumetric analysis confirmed that tumor response at 3 years reliably projected volumetric change and tumor control at 5 years (R 2  = 0.694) with P < 0.001 and 10 years (R 2  = 0.571) with P = 0.001. SRS affords effective tumor volumetric control and neurologic stability or improvement in the majority of patients with CSMs. The radiologic response of CSM as determined by volumetry at 3 years post-SRS is predictive of long-term tumor response at 5 and 10 years following SRS. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Physical properties of safflower grains. Part II: Volumetric shrinkage

    Directory of Open Access Journals (Sweden)

    Elton A. S. Martins

    Full Text Available ABSTRACT Agricultural products usually have their size reduced during the drying process. The quantification of the reduction in the dimensions is important for the development and optimization of equipment for the post-harvest of the product. The aim of the present study was to evaluate the effect of the variation in the moisture content during drying on the volumetric shrinkage of safflower grains and their respective axes. Safflower grains were harvested with an initial moisture content of approximately 0.445 decimal d.b. (dry basis and subjected to drying in an oven with forced air circulation at 40 °C, until the grains reached a final moisture content of 0.073 ± 0.008 decimal d.b. During drying, the contraction of the axes, unit volumetric shrinkage and volumetric shrinkage of the mass of safflower grains were determined at different moisture contents. Based on these results, it can be concluded that reducing the moisture content causes a reduction in the axes of safflower grains and, consequently, reductions in the unit volumetric shrinkage and volumetric shrinkage of the mass of approximately 16 and 13%, respectively, and both variables can be represented by the linear shrinkage model.

  7. Volumetric fat-water separated T2-weighted MRI

    Energy Technology Data Exchange (ETDEWEB)

    Vasanawala, Shreyas S.; Sonik, Arvind [Stanford University, Lucile Packard Children' s Hospital, Department of Radiology, Palo Alto, CA (United States); Madhuranthakam, Ananth J. [GE Healthcare, Global Applied Science Laboratory, Boston, MA (United States); Venkatesan, Ramesh [GE Healthcare, MR Engineering, Bangalore (India); Lai, Peng; Brau, Anja C.S. [GE Healthcare, Global Applied Science Laboratory, Menlo Park, CA (United States)

    2011-07-15

    Pediatric body MRI exams often cover multiple body parts, making the development of broadly applicable protocols and obtaining uniform fat suppression a challenge. Volumetric T2 imaging with Dixon-type fat-water separation might address this challenge, but it is a lengthy process. We develop and evaluate a faster two-echo approach to volumetric T2 imaging with fat-water separation. A volumetric spin-echo sequence was modified to include a second shifted echo so two image sets are acquired. A region-growing reconstruction approach was developed to decompose separate water and fat images. Twenty-six children were recruited with IRB approval and informed consent. Fat-suppression quality was graded by two pediatric radiologists and compared against conventional fat-suppressed fast spin-echo T2-W images. Additionally, the value of in- and opposed-phase images was evaluated. Fat suppression on volumetric images had high quality in 96% of cases (95% confidence interval of 80-100%) and were preferred over or considered equivalent to conventional two-dimensional fat-suppressed FSE T2 imaging in 96% of cases (95% confidence interval of 78-100%). In- and opposed-phase images had definite value in 12% of cases. Volumetric fat-water separated T2-weighted MRI is feasible and is likely to yield improved fat suppression over conventional fat-suppressed T2-weighted imaging. (orig.)

  8. Metabolic Heat Regenerated Temperature Swing Adsorption for CO2, Thermal and Humidity Control Project

    Data.gov (United States)

    National Aeronautics and Space Administration — MTSA technology specifically addresses the thermal, CO2 and humidity control challenges faced by Portable Life Support Systems (PLSS) to be used in NASA's...

  9. Effect of a controlled burn on the thermophysical properties of a dry soil using a new model of soil heat flow and a new high temperature heat flux sensor

    Science.gov (United States)

    W. J. Massman; J. M. Frank

    2004-01-01

    Some fires can be beneficial to soils but, if a fire is sufficiently intense, soil can be irreversible altered. We measured soil temperatures and heat fluxes at several soil depths before, during, and after a controlled surface burn at Manitou Experimental Forest (southern Colorado, USA) to evaluate its effects on the soil's thermophysical properties (thermal...

  10. Enhanced electrical conductivities of N-doped carbon nanotubes by controlled heat treatment.

    Science.gov (United States)

    Fujisawa, Kazunori; Tojo, Tomohiro; Muramatsu, Hiroyuki; Elías, Ana L; Vega-Díaz, Sofía M; Tristán-López, Ferdinando; Kim, Jin Hee; Hayashi, Takuya; Kim, Yoong Ahm; Endo, Morinobu; Terrones, Mauricio

    2011-10-05

    The thermal stability of nitrogen (N) functionalities on the sidewalls of N-doped multi-walled carbon nanotubes was investigated at temperatures ranging between 1000 °C and 2000 °C. The structural stability of the doped tubes was then correlated with the electrical conductivity both at the bulk and at the individual tube levels. When as-grown tubes were thermally treated at 1000 °C, we observed a very significant decrease in the electrical resistance of the individual nanotubes, from 54 kΩ to 0.5 kΩ, which is attributed to a low N doping level (e.g. 0.78 at% N). We noted that pyridine-type N was first decomposed whereas the substitutional N was stable up to 1500 °C. For nanotubes heat treated to 1800 °C and 2000 °C, the tubes exhibited an improved degree of crystallinity which was confirmed by both the low R value (I(D)/I(G)) in the Raman spectra and the presence of straight graphitic planes observed in TEM images. However, N atoms were not detected in these tubes and caused an increase in their electrical resistivity and resistance. These partially annealed doped tubes with enhanced electrical conductivities could be used in the fabrication of robust and electrically conducting composites, and these results could be extrapolated to N-doped graphene and other nanocarbons.

  11. Control of a high Reynolds number Mach 0.9 heated jet using plasma actuators

    Energy Technology Data Exchange (ETDEWEB)

    Kearney-Fischer, M.; Kim, J.-H.; Samimy, M. [Department of Mechanical Engineering, Gas Dynamics and Turbulence Laboratory, Ohio State University (GDTL/OSU), 2300 West Case Road, Columbus, Ohio 43235-7531 (United States)

    2009-09-15

    The results of particle image velocimetry (PIV) measurements in a high subsonic, heated, jet forced using localized arc filament plasma actuators (LAFPAs) show that LAFPAs can consistently produce significant mixing enhancement over a wide range of temperatures. These actuators have been used successfully in high Reynolds number, high-speed unheated jets. The facility consists of an axisymmetric jet with different nozzle blocks of exit diameter of 2.54 cm and variable jet temperature in an anechoic chamber. The focus of this paper is on a high subsonic (M{sub j}=0.9) jet. Twelve experiments with various forcing azimuthal modes (m=0, 1, and {+-}1) and temperatures (T{sub o}/T{sub a}=1.0, 1.4, and 2.0) at a fixed forcing Strouhal number (St{sub DF}=0.3) have been conducted and PIV results compared with the baseline results to characterize the effectiveness of LAFPAs for mixing enhancement. Centerline velocity and turbulent kinetic energy as well as jet width are used for determining the LAFPAs' effectiveness. The characteristics of large-scale structures are analyzed through the use of Galilean streamlines and swirling strength. Across the range of temperatures collected, the effectiveness of LAFPAs improves as temperature increases. Possible reasons for the increase in effectiveness are discussed.

  12. Performance of the Mechanically Pumped Fluid Loop Rover Heat Rejection System Used for Thermal Control of the Mars Science Laboratory Curiosity Rover on the Surface of Mars

    Science.gov (United States)

    Bhandari, Pradeep; Birur, Gajanana; Bame, David; Mastropietro, A. J.; Miller, Jennifer; Karlmann, Paul; Liu, Yuanming; Anderson, Kevin

    2013-01-01

    The challenging range of landing sites for which the Mars Science Laboratory Rover was designed, required a rover thermal management system that is capable of keeping temperatures controlled across a wide variety of environmental conditions. On the Martian surface where temperatures can be as cold as -123 C and as warm as 38 C, the Rover relies upon a Mechanically Pumped Fluid Loop (MPFL) Rover Heat Rejection System (RHRS) and external radiators to maintain the temperature of sensitive electronics and science instruments within a -40 C to +50 C range. The RHRS harnesses some of the waste heat generated from the Rover power source, known as the Multi Mission Radioisotope Thermoelectric Generator (MMRTG), for use as survival heat for the rover during cold conditions. The MMRTG produces 110 Watts of electrical power while generating waste heat equivalent to approximately 2000 Watts. Heat exchanger plates (hot plates) positioned close to the MMRTG pick up this survival heat from it by radiative heat transfer and supply it to the rover. This design is the first instance of use of a RHRS for thermal control of a rover or lander on the surface of a planet. After an extremely successful landing on Mars (August 5), the rover and the RHRS have performed flawlessly for close to an earth year (half the nominal mission life). This paper will share the performance of the RHRS on the Martian surface as well as compare it to its predictions.

  13. Development of a model system for rapid assessment of insect mortality in heated controlled atmosphere quarantine treatments.

    Science.gov (United States)

    Neven, Lisa G

    2008-04-01

    The development of postharvest quarantine treatments can be both expensive and time-consuming. It is necessary to determine the species and stage of the pest most tolerant to the treatment, if more than one species is the target of the treatment. Initial laboratory studies often include infesting the commodity with various egg and larval stages of the pest and performing treatments and evaluations of the fruit. In collaboration with others, I have previously developed combination high temperature under controlled atmosphere treatments against two quarantine pests in apples (Malus spp.) and peaches and nectarines (both Prunus spp.). I decided to develop an artificial system that can be used for these initial tests without the need for infesting large quantities of the fruit. I tested the system on the immature stages of the pests under regular air and controlled atmospheres by using the controlled atmosphere water bath system. This system can be used for rapid assessment of the most tolerant stage and species of a pest to a combination heat and controlled atmosphere treatment without the expense of infesting, treating, and evaluating the commodity.

  14. Full-spectrum volumetric solar thermal conversion via photonic nanofluids.

    Science.gov (United States)

    Liu, Xianglei; Xuan, Yimin

    2017-10-12

    Volumetric solar thermal conversion is an emerging technique for a plethora of applications such as solar thermal power generation, desalination, and solar water splitting. However, achieving broadband solar thermal absorption via dilute nanofluids is still a daunting challenge. In this work, full-spectrum volumetric solar thermal conversion is demonstrated over a thin layer of the proposed 'photonic nanofluids'. The underlying mechanism is found to be the photonic superposition of core resonances, shell plasmons, and core-shell resonances at different wavelengths, whose coexistence is enabled by the broken symmetry of specially designed composite nanoparticles, i.e., Janus nanoparticles. The solar thermal conversion efficiency can be improved by 10.8% compared with core-shell nanofluids. The extinction coefficient of Janus dimers with various configurations is also investigated to unveil the effects of particle couplings. This work provides the possibility to achieve full-spectrum volumetric solar thermal conversion, and may have potential applications in efficient solar energy harvesting and utilization.

  15. Open loop control of filament heating power supply for large volume plasma device

    Energy Technology Data Exchange (ETDEWEB)

    Sugandhi, R., E-mail: ritesh@ipr.res.in [Institute for Plasma Research, Gandhinagar, Gujarat 382428 (India); Homi Bhabha National Institute, Mumbai 400094 (India); Srivastava, P.K.; Sanyasi, A.K. [Homi Bhabha National Institute, Mumbai 400094 (India); Srivastav, Prabhakar [Institute for Plasma Research, Gandhinagar, Gujarat 382428 (India); Homi Bhabha National Institute, Mumbai 400094 (India); Awasthi, L.M., E-mail: kushagra.lalit@gmail.com [Institute for Plasma Research, Gandhinagar, Gujarat 382428 (India); Homi Bhabha National Institute, Mumbai 400094 (India); Mattoo, S.K. [Homi Bhabha National Institute, Mumbai 400094 (India)

    2017-02-15

    A power supply (20 V, 10 kA) for powering the filamentary cathode has been procured, interfaced and integrated with the centralized control system of Large Volume Plasma Device (LVPD). Software interface has been developed on the standard Modbus RTU communication protocol. It facilitates the dashboard for configuration, on line status monitoring, alarm management, data acquisition, synchronization and controls. It has been tested for stable operation of the power supply for the operational capabilities. The paper highlights the motivation, interface description, implementation and results obtained.

  16. Model Predictive Control of Offshore Power Stations With Waste Heat Recovery

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Chan, Richard; Li, Xiangan

    2016-01-01

    Rankine cycle (ORC) turbogenerator to increase the energy conversion efficiency. Results show a potential reduction of frequency drop up to 40%for a step in the load set-point of 4 MW, compared to proportional–integral control systems. Fuel savings in the range of 2–3% are also expected by optimizing on...... control (MPC) coupled with a steady-state performance optimizer has been developed in the SIMULINK language and is documented in the paper. The test case is the regulation of a power system serving an oil and gas platform in the Norwegian Sea. One of the three gas turbines is combined with an organic...

  17. Comparison of strategies for model predictive control for home heating in future energy systems

    DEFF Research Database (Denmark)

    Vogler-Finck, Pierre Jacques Camille; Popovski, Petar; Wisniewski, Rafal

    2017-01-01

    Model predictive control is seen as one of the key future enabler in increasing energy efficiency in buildings. This paper presents a comparison of the performance of the control for different formulations of the objective function. This comparison is made in a simulation study on a single building...... using historical weather and power system data from Denmark. Trade-offs between energy consumption, comfort and incurred CO2 emissions depending on the chosen objective function are quantified, highlighting the need to carefully select the strategy used in future design and implementation, rather than...

  18. Feedback control for distributed heat transfer mechanisms in direct-contact membrane distillation system

    KAUST Repository

    Eleiwi, Fadi

    2015-09-21

    In this paper, the problem of stabilization and production rate reference tracking for a Direct-Contact Membrane Distillation (DCMD) system is addressed. Sufficient conditions for the asymptotic and exponential stabilization for DCMD system are presented using the Gronwall-Bellman lemma and Linear Matrix Inequalities (LMIs) approaches, respectively. A nonlinear observer is then proposed to estimate the temperature distribution among the DCMD domain. This contributes to propose a reference production rate control design for the DCMD process via observer-based output control approach. Finally, numerical simulations are given to show the effectiveness of the proposed methods.

  19. Theoretical study of heat pump system using CO2/dimethylether as refrigerant

    Directory of Open Access Journals (Sweden)

    Fan Xiao-Wei

    2013-01-01

    Full Text Available Nowadays, HCFC22 is widely used in heat pump systems in China, which should be phased out in the future. Thus, eco-friendly mixture CO2/dimethylether is proposed to replace HCFC22. Compared with pure CO2 and pure dimethylether, the mixture can reduce the heat rejection pressure, and suppress the flammability and explosivity of pure dimethylether. According to the Chinese National Standards on heat pump water heater and space heating system, performances of the subcritical heat pump system are discussed and compared with those of the HCFC22 system. It can be concluded that CO2 /dimethylether mixture works efficiently as a refrigerant for heat pumps with a large heat-sink temperature rise. When mass fraction of dimethylether is increased, the heat rejection pressure is reduced. Under the nominal working condition, there is an optimal mixture mass fraction of 28/72 of CO2/dimethylether for water heater application under conventional condensation pressure, 3/97 for space heating application. For water heater application, both the heating coefficient of performance and volumetric heating capacity increase by 17.90% and 2.74%, respectively, compared with those of HCFC22 systems. For space heating application, the heating coefficient of performance increases by 8.44% while volumetric heating capacity decreases by 34.76%, compared with those of HCFC22 systems. As the superheat degree increases, both the heating coefficient of performance and volumetric heating capacity tend to decrease.

  20. The Helicobacter Eradication Aspirin Trial (HEAT): A Large Simple Randomised Controlled Trial Using Novel Methodology in Primary Care.

    Science.gov (United States)

    Dumbleton, Jennifer S; Avery, Anthony J; Coupland, Carol; Hobbs, F D Richard; Kendrick, Denise; Moore, Michael V; Morris, Clive; Rubin, Greg P; Smith, Murray D; Stevenson, Diane J; Hawkey, Chris J

    2015-09-01

    Clinical trials measuring the effect of an intervention on clinical outcomes are more influential than those investigating surrogate measures but are costly. We developed methods to reduce costs substantially by using existing data in primary care systems, to ask whether Helicobacter pylori eradication would reduce the incidence of hospitalisation for ulcer bleeding in aspirin users. The Helicobacter Eradication Aspirin Trial (HEAT) is a National Institute of Health Research-funded, double-blind placebo controlled randomised trial of the effects of H. pylori eradication on subsequent ulcer bleeding in infected individuals taking aspirin daily, conducted in practices across the whole of England, Wales and Northern Ireland. A bespoke web-based trial management system developed for the trial (and housed within the secure NHS Data Network) communicates directly with the HEAT Toolkit software downloaded at participating practices, which issues queries searching entry criteria (≥ 60 years, on chronic aspirin ≤ 325 mg daily, not on anti-ulcer therapy or non-steroidal anti-inflammatory drugs) for GP review of eligibility. Trial participation is invited using a highly secure automated online mail management system. Interested patients are seen once for consent and breath testing. Those with a positive test are randomised to eradication treatment (lansoprazole, clarithromycin, metronidazole) or placebo, with drug sent by post. Events are tracked by upload of accumulating information in the GP database, patient contact, review of National Hospital Episode Statistics and Office of National Statistics data. HEAT is the largest Clinical Research Network-supported drug trial, with 115,660 invitation letters sent from 850 practices, 22,922 volunteers, and 3038 H. pylori positive patients randomised to active or placebo treatment after 2.5 years of recruitment. 178 practices have performed their first follow-up data search to identify 21 potential endpoints to date. HEAT