bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Correlation for Temperature Rise Correction of Heat Flux Gages
Authors: Mukerji Debjit , Eaton John K. , Moffat Robert J. 
Published: January 2022

Abstract
Experimental and numerical studies of turbulent heat transfer near a step change in wall temperature have been conducted in connection with an error analysis of small, transient, heat flux gages. The surface temperature of such a gage typically rises above the temperature of the surrounding metal wall, which influences the heat flux to the gage. Data from such gages must be corrected for the effect of this temperature rise. The correction is typically made by superposition using an unheated starting-length correlation, a procedure that has been in practice for many years.
In the present work, experimental data from a small, isothermal calorimeter were compared with output from STAN7, a 2-D turbulent boundary layer code, and with predictions based on a textbook correlation. The experiments and the numerical predictions agree within +/−6%, but the correlation underpredicts the required correction by 15–20% over the first half-boundary layer thickness downstream of the step change. As a consequence, data from small gages cannot be properly corrected using the accepted correlation.
A new expression is proposed for Stanton number downstream of a step in wall temperature, which can be used as an accurate correction algorithm for use with small gages.
Local Hyperthermic Treatment of Solid Tumors: Interplay Between Thermal Dose and Physiological Parameters
Authors: Griffin Robert J. , Ogawa Atsushi , Shakil Abdus , Song Chang W. 
Published: January 2022

Abstract
Reduction of tumor blood flow during hyperthermia may impair the ability of the tumor vasculature to dissipate heat and lead to greater tumor cell killing. We are currently testing a new compound (KB-R8498) which has been found to reduce tumor blood flow. One hour after an i.v. or an i.p. injection of KB-R8498 the blood flow in SCK tumors of A/J mice was reduced to 40%–70% of control. The blood flow in 6 A/J mouse normal tissues one hour after drug treatment was mostly unchanged. Control tumors grew to four times the starting volume in 6 days. An injection of 10 mg/kg KB-R8498 caused a growth delay of about 2 days. After tumors were heated at 42.5°C for 60 min, there was a delay of 4 days in tumor growth. When i.p. or i.v. injections of KB-R8498 were given and the tumors were heated at 42.5°C for 60 min, there was a growth delay of over 10 days. The implications for clinical hyperthermia treatments are discussed.
The Kinetics of Thermal Damage: Estimation and Evaluation of Model Coefficients
Authors: Pearce John , Liao Wen Huang , Thomsen Sharon 
Published: January 2022

Abstract
Successful use of kinetic models of thermal damage processes depends critically upon the identification of a quantitative measure of thermal damage. Most clinically relevant processes are qualitative in nature and are not easily studied by the standard Arrhenius formulation. Quantitative markers of thermal damage include: 1) loss of birefringence properties in muscle and collagen, 2) loss of hemoglobin from red blood cells, 3) uptake of enzymatically active dyes and 4) diffusion of dyes across vessel walls. When a quantitative marker is used the kinetic coefficients estimated from experiments over different time scales are significantly different. Application of coefficients determined in long term studies (exposure times on the order of hours) to short term exposures (electrosurgical coagulation or short laser pulses) is questionable and often leads to counter-intuitive predictions of damage boundaries. Short term exposures, on the other hand, are by definition not of constant temperature and often defy estimation of the coefficients from the transient history. We present and compare several sets of estimated thermal damage coefficients for similar and differing processes and a preliminary method for extracting estimates from transient histories.
A Theoretical FE-Based Model Developed to Predict the Relative Contribution of Convective and Diffusive Transport Mechanisms for the Maintenance of Local Equilibria Within Cortical Bone
Authors: Tate Melissa L. Knothe , Niederer Peter 
Published: January 2022

Abstract
Whereas diffusion has been shown to be the major contributing mechanism for mass transfer in the extravascular spaces of organs and soft tissues, it is unlikely that diffusion alone can account for sufficient molecular transport in the porous yet relatively impermeable tissue of cortical bone. An alternate mechanism for such mass transfer is intrinsic to the functional role of cortical bone in transferring loads within the musculoskeletal system. Namely, it has been proposed that mechanical loading causes minute deformations within the poroelastic tissue of cortical bone, resulting in extravascular fluid displacements. This biophysical phenomenon is referred to as load-induced interstitial or extravascular fluid flow.
In order to establish the role of convective transport mechanisms for maintenance of healthy bone metabolism and to investigate the potential role of convective transport (via load-induced fluid flow) for processes associated with functional adaptation, we developed a theoretical osteon model based on finite element methods. A study designed to simulate short term transport (circa 1 second or half a gait cycle) in a single osteon corroborated the hypothesis that diffusion alone is insufficient for molecular transport between the blood supply and remotely lying bone cells. Simulations of long term transport (circa one day) showed that convection via load-induced flow can be expected to improve this transport significantly.
Use of a Genetic Algorithm in Near-Infrared Imaging
Authors: Jones Matthew R. 
Published: January 2022

Abstract
The development of noninvasive medical imaging techniques over the last several decades has greatly increased the ability of physicians to detect and diagnose disease and injury. Near-infrared imaging is a modality which uses red and near-infrared radiation to probe biological tissues. There are several advantages to using near-infrared radiation. One advantage is that information regarding both the structure and functional status of tissue can be obtained. Another advantage is that it is possible to continuously monitor tissue using near-infrared imaging. However, unlike x-rays near-infrared radiation is highly scattered by biological tissues, so conventional image reconstruction techniques are not applicable. This paper describes a preliminary investigation into the use of an image reconstruction technique based on a genetic algorithm. Numerical simulations of continuous-wave relative transmission measurements through a cylindrical object are used as the inputs to the image reconstruction algorithm. Tomographic images of the object obtained using a genetic algorithm are compared with an image obtained using a gradient based algorithm. These results show that the genetic algorithm is more robust than the gradient based algorithm.
Ice Front Propagation Monitoring in Tissue Using Visible Light Transmission: Behavior Prediction Using Photon Diffusion Model
Authors: Otten David M. , Rubinsky Boris 
Published: January 2022

Abstract
A two-dimensional finite difference diffusion model was developed to analyze the effects of a propagating ice front on the continuous wave intensity transmission across a tissue sample. The calculated diffusion model transmissions for a transilluminating emitter/detector fiber configuration were compared to experimentally obtained transmissions for consecutive ice front positions within the tissue sample. The diffusion model was able to predict the transmission behavior for this fiber configuration given the absorption and scattering coefficients of the frozen and unfrozen tissue. Calibration algorithms for similar fiber probe placements based on this model may eventually be used with real-time transmission measurements to allow visible light monitoring of ice front position in tissue. This demonstration has potentially important medical applications in cryopreservation (freezing of biological materials for preservation) and cryosurgery (destruction of tissue by freezing).
Energy Level Concept and its Application to Improvement of Absorption Heat Transformer
Authors: Ishida Masaru , Ji Jun 
Published: January 2022

Abstract
A graphical exergy study based on energy-utilization diagrams (EUDs) is performed on the multiple-compartment generator and multiple-compartment absorber in close-to-equilibrium operation in a single stage absorption heat transformer (SAHT). The working fluid considered for the heat transformer is water-lithium bromide. This analysis provides detailed information on internal phenomena such as the driving forces and the distribution of the exergy loss in each subsystem. The results show that the multiple-compartment absorber can improve the temperature lift and exergy efficiency, whereas the multiple-compartment generator can extend the heat source temperature range. The effect of solution concentration is also investigated.
Modeling and Experimental Investigation of Dynamics of a Directly Combined Binary Turbine System Using Steam and R123
Authors: Tanzawa Yoshiaki , Terashima Yukio , Amano Yoshiaru , Kato Ryo , Hashizume Takumi , Usui Akira 
Published: January 2022

Abstract
The binary turbine system that employs steam as the primary working fluid has used R11 as the secondary working fluid, because R11 has good characteristics as a working fluid in power plants. However, substitute LBMs (low boiling-temperature mediums compared with water) are being developed because of the destruction of the ozone layer by CFCs. In this paper, modeling and experimental investigations into the dynamics of a directly combined binary turbine system using R123 instead of R11 are described. The system consists mainly of a steam- and an R123-turbine, an R123 vapor generator, and an AC generator. The dynamic behavior of the system is discussed from the viewpoint of the network theory. The components of the system are represented as two- or three-port elements of the network and the vapor flow rate and shaft torque are appropriated as the through variable, and the vapor pressure and rotational speed as the across variable. As a result, a very simple network model based on the dynamics of various turbine systems like this was derived. The validity of the model was proven through comparison with our experimental results, which are the frequency responses examined with respect to generator load changes. In addition, we demonstrate that the model is very effective in predicting the dynamic behavior and power generation mechanism of directly combined binary turbine systems.
How the Water Section in the Hat Cycle Can Be an Efficient Power Output Modulator
Authors: Di Maria Francesco , Desideri Umberto 
Published: January 2022

Abstract
After a long period during which theoretical analyses were presented on evaporative gas turbine cycles, such as the HAT (Humid Air Turbine) and CHAT (Cascaded Humid Air Turbine), the first experimental plant with water recovery is currently under construction at the Lund Institute of Technology in Sweden. The pilot plant is due to start in evaporative mode in May 1998, and this represents the first step for the validation of the humid air turbine concept.
One of the main points of interest is the power modulation which should be possible controlling the evaporated water flow rate. If the whole compressed air flow rate is introduced into the evaporator the possibilities to vary its water content are scarce if the temperatures in the recuperator are not changed. A solution to this problem has been patented by Vattenfall AB, and consists in bypassing a fraction of the air entering the evaporator directly into the recuperator.
In this paper a detailed study of the different evaporation modes is presented from the point of view of both the first and second law analysis. The thermodynamic analysis will also be compared with the operational flexibility that the by-pass solution offers. Applications to some commercial turbines, which are most suited to use in HAT cycle mode, will also be presented.
The Impact of Imperfect Intercooling on Combined Cycle Performance
Authors: Sivasubramanian J. , Balasubramaniam L. , Ramayya A. Venkata 
Published: January 2022

Abstract
The effect of imperfect intercooling of the compression stages on the combined cycle performance is studied by characterizing the alteration in performance in terms of degree of imperfect intercooling. A combined cycle configuration with a two stage compressor and a two stage reheat turbine is considered and irreversibilities of various components are studied with regard to the effectiveness of intercooler by making energy and exergy balances. The first and second-law efficiencies are discussed as a function of the level of intercooling and the trade of involved between the additional work input and the availability gain at compressor exit. The irreversibilities of various components are found to increase with a higher level of intercooling while the first and second-law efficiencies of the combined cycle are shown to exhibit a maximum at an optimum pressure ratio. Compared to the case of perfect intercooling, imperfect intercooling is found to result in a significant improvement in the magnitudes of first and second-law efficiencies of the combined cycle.
Loops and Thermodynamics
Authors: Ishida Masaru , Suzuki Takahiro , Yamamoto Masashi 
Published: January 2022

Abstract
Cycles such as a Rankine cycle, Calvin cycle, etc. play important roles. They consist of a set of specific processes and exhibit specific functions by this whole set of processes.
Two methods to examine those specific functions graphically are presented based on thermodynamics. The first method is to trace the ratio of the exergy gained to the energy gained by the circulating substance. The second method is to display release and acceptance of heat-equivalent as well as work-equivalent energies. Those methods reveals that loops have three important features; work (or work-equivalent energy) integration, creation of specific fields, and functions to purify a target component and to reduce wastes. All of these features are keys to create a sustainable society.
On the Definition of Entropy and Temperature and on the Energy Interactions
Authors: Kouremenos D. A. 
Published: January 2022

Abstract
The thermodynamic systems considered here are those that can be described by using only two macroscopic variables. For this purpose the specific volume v and the specific internal energy u are used while the pressure function p(u,v) is supposed to be known. It is shown that by a suitable mathematical transformation of variables, the pair (u,v) can be replaced by the pair of functions temperature T(u,v) and entropy s(u,v) that are defined simultaneously by a proposed generic system of differential equations without using the concept of heat. To show the authenticity of these definitons some solutions of this generic system of differential equations are given and in addition to, the special case of the perfect gas is obtained as one of the results. It is proposed to add to the conventional concepts of work and heat a third constitutive component, the throttling. With it the local efficiency η of a differential themodynamic change can be defined. In addition this allows for the deduction of the relation (pdv + du) ≥ 0 as a consequence. The heat-work energy interactions with a thermodynamic system are taking place mostly through an enclosing boundary wall. As these two different forms of energy flow cross the boundary wall, they undergoe some transformation. As a result, the heat and work flow through the wall from/to the outer space to/from the system considered may change, although its algebraic sum, the total energy transfered, retains its initial value. Vector notation is used to facilitate the description of this transformation of energy crossing a boundary wall.
United States Department of Energy Large Commercial Absorption Chiller Development Program
Authors: Garland Patricia Welesko , DeVault Robert C. , Zaltash Abdi 
Published: January 2022

Abstract
The U.S. Department of Energy (DOE) is working with partners from the gas cooling industry to improve energy efficiency and U.S. competitiveness by using advanced absorption technologies that eliminate the use of chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs), refrigerants that contribute to ozone depletion and global warming. Absorption cooling uses natural gas as the heat source, which produces much lower NOx emissions than oil- or coal-generated electricity. Gas-fired chillers also have the advantage of helping reduce peak electrical usage during summer months. To assist industry in developing advanced absorption cooling technologies, DOE sponsors the Large Commercial Chiller Development Program. The goal of the program is to improve chiller cooling efficiency by 30–50% compared with the best currently available absorption systems.
Compressible Fluid Flow and Heat Transfer Navier-Stokes Predictions on Unstructured Grids
Authors: Marques Nelson P. C. , Pereira José C. F. 
Published: January 2022

Abstract
A second-order accurate finite volume method for solving compressible 2D flows on hybrid structured-unstructured grids is presented. Separate reconstruction and evolution steps are taken to discretize the convective terms. For the reconstruction step, a data-dependent Least-Squares procedure is used, while for the evolution step two recent flux functions are included: the HLLC approximate Riemann solver and the AUSM+ flux vector splitting. Steady-state solutions are obtained with an implicit backward Euler scheme. The assembled system is solved by iterative means (BiCGSTAB, GMRES) with ILU pre-conditioning.
Two internal, steady, 2D flow test cases are presented to validate the code: a supersonic 10° ramp inside a channel and a laminar flow through a double-throated nozzle.
The code proved accurate with the use of both flux functions when comparing the computed results with both an analytical (ramp) and a reference solution (nozzle). The GMRES solver generally required less CPU time until convergence for the inviscid test-case while the BiCGSTAB solver got the edge for the viscous calculations.
Heat Transfer in Reciprocating Compressors: A Review
Authors: Prasad B. G. Shiva 
Published: January 2022

Abstract
Heating is an undesirable effect of the compression process at least as far as compressors are concerned and heat transfer is nature’s way of driving systems towards stability. This has not only provided food for thought for researchers trying to understand its influence and quantify its effects, but also challenged designers to mitigate its impact and develop safe and efficient designs. Also, just as any other unwanted phenomenon would spur curiosity and inventiveness, this has led to the development of a host of new materials both metallic as well as non-metallic to withstand the vagaries of high temperatures, in addition to the toxic environment present in many gas compressors used in pumping and process industries. This paper is an attempt to present some of the problems created by this unwanted phenomenon, review the contributions of some of the past investigators, and kindle more interest for furthering the advancement of compressor technology.
Transient Heat Transfer Approximations for Ground-Source Heat Pump Design
Authors: Stevens James W. 
Published: January 2022

Abstract
Design of ground-source heat pump systems requires an estimation of the heat transfer between a buried pipe and the surrounding ground. Since heat pumps normally operate intermittently, the heat transfer with intermittent boundary conditions is important. While a variety of useful tools exist for numerically determining the heat transfer characteristics of any given system, it is unwieldy to use such tools for rough or preliminary estimates of system sizes. This paper describes the development of accurate simple approximations for the heat transfer from a round pipe buried in an infinite medium with the pipe wall intermittently changing between isothermal and adiabatic conditions. It is shown that the steady-boundary case provides an upper bound on the time-averaged heat transfer from the pipe and a lower bound on the instantaneous heat transfer rate. For a low thermal diffusivity medium, the time averaged intermittent heat transfer rate approaches that of the steady boundary case, while for a high value of thermal diffusivity, the time averaged heat transfer decreases faster than it does in the steady boundary case. The overall heat transfer can be well correlated with simple functions over a range of thermal diffusivities, intermittence intervals, and time.
Comparison of Analytical and Experimental Effectiveness of Four-Row Plate-Fin-Tube Heat Exchangers With Water, R-22 and R-410A
Authors: Chen Tony D. , Conklin James C. , Baxter Van D. 
Published: January 2022

Abstract
The analytical solutions of heat exchanger effectiveness for four-row crossflow, cross-counterflow and cross-parallelflow have been derived in the recent study. The main objective of this study is to investigate the effect of heat exchanger flow configuration on thermal performance with refrigerant mixtures. Difference of heat exchanger effectiveness for all flow arrangements relative to an analytical many-row solution has been analyzed. A comparison of four-row cross counterflow heat exchanger effectiveness between analytical solutions and experimental data with water, R-22, and R-410A is presented.
Numerical Modeling of Conjugate Heat Transfer During Free Liquid Jet Impingement
Authors: Rahman Muhammad M. , Bula Antonio J. , Leland John E. 
Published: January 2022

Abstract
The paper presents the results of numerical simulation of a free jet of high Prandtl number fluid impinging perpendicularly on a solid substrate of finite thickness containing electronics on the opposite surface. The numerical model was developed considering both solid and fluid regions and solved as a conjugate problem. Equations for the conservation of mass, momentum, and energy were solved in the liquid region taking into account the transport processes at the inlet and exit boundaries as well as at the solid-liquid and liquid-gas interfaces. In the solid region, only heat conduction equation was solved. The shape and location of the free surface (liquid-gas interface) was determined iteratively as a part of the solution process by satisfying the kinematic condition as well as the balance of normal and shear forces at this interface. The number of elements in the fluid and solid regions were determined from a systematic grid-independence study. A non-uniform grid distribution was used to adequately capture large variations near the solid-fluid interface. Computed results included the velocity, temperature, and pressure distributions in the fluid, and the local and average heat transfer coefficients at the solid-fluid interface. Computations were carried out to investigate the influence of different operating parameters such as jet velocity, heat flux, plate thickness, and plate material. Numerical results were validated with available experimental data. It was found that the local heat transfer coefficient is maximum at the center of the disk and decreases gradually with radius as the flow moves downstream. The average heat transfer coefficient and the maximum temperature occurring in the solid decreased with increase of disk thickness and increase of thermal conductivity of the disk material.