bluuebunny/crossref_metadata_2025 huggingface dataset:
Antipsychotic medicines in Australian community practice: Effectiveness, adverse effects and quality of life for people with schizophrenia
Authors: Harvey Carol , Hawthorne Graeme , Favilla Amanda , Graham Carolyn , Herrman Helen
Published: February 2012

Introduction

Atypical antipsychotics are increasingly recommended as first‐line treatments in international clinical guidelines. However, recent meta‐analyses and effectiveness studies have found few differences between typicals and atypicals. We aimed to assess the use of atypical and typical antipsychotic medicines, their perceived effectiveness and tolerability, and associated health‐related quality of life among Australian community patients with an established diagnosis of schizophrenia or related disorders.

Methods

A random sample of people with schizophrenia spectrum disorders (n = 83) attending four public mental health clinics, and their treating clinicians and family carers, completed questionnaires on the effectiveness, acceptability and side‐effects of current, previous and early antipsychotic medicine. Medicine use was determined from clinical notes. The Assessment of Quality of Life, Drug Attitude Inventory and Friendship Scale were also used.

Results

A significant shift over time towards atypical medicine use was reported: 66% of current antipsychotic use. Perceived effectiveness, satisfaction and side‐effects did not differ when comparing medicine type (typical/depot/atypical) for early, previous and current medicines used. Health‐related quality of life was associated with reported side‐effects, but not with current medicine type. Agreement was poor between patients, case managers and carers about medicine use.

Discussion

Consistent with recent effectiveness trials, the findings suggest that any differences in the experience of typical and atypical antipsychotics of patients with established illnesses are obscured in the complex setting of real‐world practice. Further, poor agreement between patients, case managers and carers about medicine use may indicate that they each have different understandings of the medicines that are being used.
Elderly suicide in Chinese populations
Authors: Ho Emily C.L. , Chiu Helen F.K. , Chong Mian‐Yoong , Yu Xin , Kundadak Ganesh , Kua Ee Heok
Published: February 2012

Introduction

Studies on suicide rate in the elderly have shown vast differences in different regions. This review summarizes the literature on the elderly suicide trend in Chinese populations, namely China, Hong Kong, Taiwan and Singapore, comparing these data to those in the USA and the UK.

Methods

We reviewed 22 articles which we retrieved from a computerized search on elderly suicide in Chinese population from the above four regions.

Results

These studies reported a general downward trend in elderly suicide, with higher rates in the Asian Chinese population. These studies also reported a higher rate of elderly male suicide compared to elderly female, with hanging being the most common method in urban areas.

Discussion

Looking into suicide prevention programs and their relationship with the suicide trend, we hope to bring across a strong message that suicide is preventable. We also hope to encourage more research in this field, especially in preventive medicine, targeting at‐risk individuals in the community.
Globalization and the Kalashnikov: Public–Private Networks in the Trafficking and Control of Small Arms
Authors: Bolton Matthew , Sakamoto Eiko Elize , Griffiths Hugh
Published: February 2012

This article will show how trends of globalization have transformed both the proliferation of and efforts to control small arms and light weapons (SALW). We first examine how the distribution of small arms has become more diffused, moving away from a state‐centric model of ‘arms transfers’ to circulations of SALW through outsourced networks comprising a myriad of public and private actors. We then show how the post‐Cold War international environment has allowed progressive norm entrepreneurs like middle powers and NGOs greater voice in determining SALW policy. Simultaneously, however, it has also allowed great power states and defense companies to benefit from the legitimacy of associating with human rights groups, ‘capturing’ the SALW policy process, particularly the Arms Trade Treaty, in a way that protects their interests. Efforts to transfer, exchange and control small arms and light weapons are thus indicative of wider global political processes in which power is diffused through multilayered networks and complexes. Exploring the policy implications, we argue that these networks enable actors to augment their power and capacity through alliances with other agents, but simultaneously constrain their scope of action and ability to control the process. This makes it more difficult for actors representing the public interest to override those acting in private or particularist interests.

Policy Implications

Globalization makes it more difficult for those making policy in the public interest to constrain and resist capture by private interests, or to control the direction of the process when there are many actors involved. Therefore:

 Global policy success requires a thorough understanding of how to navigate and operate in multilevel, multi‐actor, multinational and multi‐scale networks.

 Global policy makers and activists need to become increasingly familiar with operating strategically in networks and complexes of public and private actors, selecting allies and contractors who share values and interests that are consistent with the intended policy outcomes.

 A smaller, more coherent campaign network can sometimes be more effective and mobilize more strategically than a broad‐based, diffused coalition.

 Rather than focusing simply on state‐centric treaties, global policy making around multifaceted issues like SALW proliferation may be better served by created multilayered ‘regime complexes’, incorporating a network of mutually reinforcing institutions, norms, treaties, programs, embargoes and campaigns.
Use of a modified shell technique for three‐dimensional bone grafting: description of a technique
Authors: Stimmelmayr M , Güth J‐F , Schlee M , Göhring TN , Beuer F
Published: February 2012

Background:  Defects of the alveolar crest often lead to three‐dimensional bone loss after tooth extraction. Therefore, hard tissue grafting is required prior to implant placement. Different techniques have been described in the literature.

Methods:  In this case report three‐dimensional hard tissue grafting was performed with a modified shell technique and autogenous bone harvested from the mandibular ramus. The shells were trimmed to a thickness of 1 mm and placed to recontour the ideal shape of the alveolar ridge. The shells were then fixed with micro titanium screws, and the gap between the shells and the alveolar ridge was filled with autogenous bone chips.

Results:  Wound healing was uneventful. Consolidation of the bone graft showed almost no resorption and the implant was placed into vital bone.

Conclusions:  The described shell technique for rebuilding three‐dimensional alveolar defects showed promising results and could be an alternative treatment to other hard tissue grafting techniques.
Insulin secretory capacity and insulin sensitivity in impaired fasting glucose in Japanese
Authors: Mitsui Rie , Fukushima Mitsuo , Taniguchi Ataru , Nakai Yoshikatsu , Aoyama Sae , Takahashi Yoshitaka , Tsuji Hideaki , Yabe Daisuke , Yasuda Koichiro , Kurose Takeshi , Kawakita Toshiko , Seino Yutaka , Inagaki Nobuya
Published: February 2012

Aims/Introduction:  Impaired fasting glucose (IFG) increases the risk of developing diabetes mellitus (DM). This study was carried out to characterize Japanese patients who have fasting glucose levels (FPG) between 100 and 109 mg/dL (IFG100–109).

Materials and Methods:  A total of 1383 Japanese participants were examined by oral glucose tolerance test. We compared insulin secretory capacity (insulinogenic index) and insulin sensitivity (ISI composite) of IFG100–109/normal glucose tolerance (NGT; 100 ≤ FPG < 110 mg/dL and 2‐h postchallenge glucose level (2‐hPG) < 140 mg/dL) with NGT (100 mg/dL < FPG and 2‐hPG < 140 mg/dL) and IFG110–125/NGT (110 ≤ FPG < 126 mg/dL and 2‐hPG < 140 mg/dL). In addition, IFG100–109 patients were analyzed in three subgroups according to glucose intolerance by 2‐hPG.

Results:  Of the three categories of IFG100–109, IFG100–109/DM had the lowest insulinogenic index despite an ISI composite showing only a small decline from IFG100–109/NGT through IFG100–109/IGT (100 ≤ FPG < 110 mg/dL and 140 ≤ 2‐hPG < 200 mg/dL) to IFG100–109/DM (100 ≤ FPG < 110 mg/dL and 200 mg/dL < 2‐hPG). By multiple regression analysis, the insulinogenic index showed a significant relationship with 2‐h PG levels. Both insulinogenic index and ISI composite were decreased significantly from NGT through IFG100–109/NGT to IFG110–125/NGT.

Conclusions:  Although impaired early‐phase insulin secretion plays the more important role in the elevation of postchallenge glucose in IFG100–109 patients, both impaired early‐phase insulin secretion and decreased insulin sensitivity are involved in the deterioration of FPG in Japanese. In addition, insulin secretory defect and decreased insulin sensitivity already have begun in patients with IFG100–109.(J Diabetes Invest, doi: 10.1111/j.2040‐1124.2012.00201.x, 2012)
Purinergic neuromuscular transmission is absent in the colon of P2Y1 knocked out mice
Authors: Gallego Diana , Gil Víctor , Martínez‐Cutillas Míriam , Mañé Noemí , Martín Maria Teresa , Jiménez Marcel
Published: February 2012

Key points 

Neural‐mediated relaxation occurs in the gastrointestinal tract. To accomplish this function, two neurotransmitters, ATP or a related purine and nitric oxide, are released by inhibitory motorneurons.

The type of purinergic receptor is still under debate but previous data using a classical pharmacological approach (receptor agonists and antagonists) suggested that P2Y1 receptors are responsible for purinergic neurotransmission in the gastrointestinal tract.

In the present study we used a genetically modified mouse in which P2Y1 receptors had been knocked out.

P2Y1‐deficient mice had functional nitrergic neurotransmission but purinergic neurotransmission was absent.

The present work confirms the hypothesis demonstrating that P2Y1 receptors mediate the purinergic component of the smooth muscle relaxation in the gastrointestinal tract.
The Solution of Temperature Development in the Entrance Region of an MHD Channel by the B. G. Galerkin Method
Authors: LeCroy R. C. , Eraslan A. H.
Published: February 2012

The general mathematical problem of MHD thermal entrance regions is formulated for a parallel plate channel by including Joule heating, viscous dissipation, and the effect of axial conduction. The associated eigenvalue problem is solved by the B. G. Galerkin method and the results are presented for constant wall temperature and constant wall heat flux conditions. It is shown that the particular method has distinct computational advantages over the classical form of solutions. The constant wall temperature case is investigated by employing the solutions of the eigenvalue problem and it is concluded that the axial conduction has considerable effect on the temperature development for low values of Peclet number.
Migrational Properties for the Steady Forced Vaporization of Water
Authors: Erikson T. A. , Tykodi R. J.
Published: February 2012

New data for the steady forced vaporization of water has been obtained. Experiments were conducted in five tube bores ringing from 1.9 to 9.5 mm in tube radius at three bath temperatures. The data were normalized and, by applying classical thermodynamic principles to irreversible processes that were conducted steadily, resistances to vaporization were derived. Values of 3.16, 6.06, and 13.7 μmole/sec-mm2 were derived as equipment-independent properties of water in steady forced vaporization at bath temperatures of 50, 25, and 4 deg C, respectively. Convection currents in the liquid were identified as the primary factor that governs steady vaporization by forced means.
A Calorimeter Apparatus to Measure the Enthalpy Difference of Heavy Water
Authors: Nowak E. S. , Chan J.
Published: February 2012

A nonflow calorimeter apparatus to measure the enthalpy difference of saturated liquid heavy water from 100 to 350 deg F was designed and developed. The reliability of the apparatus and associated instrumentation was evaluated by conducting a series of measurements on the empty calorimeter and on the calorimeter when it contained a sample of saturated light water. The apparatus yielded information on the enthalpy differences of liquid light water corresponding to temperature changes of 40 deg F accurate to within ±0.4 percent and reproducible to ±0.1 percent.
A New Correlation of Pool-Boiling Data Including the Effect of Heating Surface Characteristics
Authors: Mikic B. B. , Rohsenow W. M.
Published: February 2012

The standard approach which relates heat transfer in nucleate boiling to heat transfer to the superheated layer averaged over the time between two successive departures of a bubble from a given site is extended in order to relate the heat flux to the wall superheat through the heating surface characteristic. It was found that the q/A versus ΔT relation depends on the cavity size distribution over the surface. For a known distribution of cavity size, the q/A versus ΔT relation may be predicted, or for unknown characteristics of the boiling surface it is sufficient to have boiling data at one pressure in order to predict the q/A versus ΔT relation of other pressure levels for the same surface and the same liquid. The latter was tried on a wide range of experimental data including water and three organic liquids with good results.
The Mechanism of and Stability Criterion for Nucleate Pool Boiling of Sodium
Authors: Shai I. , Rohsenow W. M.
Published: February 2012

Experimental data for sodium boiling on horizontal surfaces containing artificial cavities at heat fluxes of 20,000 to 300,000 Btu/ft2 hr and pressures between 40 to 106 mm Hg were obtained. Observations are made for stable boiling, unstable boiling and “bumping.” Some recorded temperature variations in the solid close to the nucleating cavity are presented. It is suggested that for liquid metals the time for bubble growth and departure is a very small fraction of the total bubble cycle, hence the delay time during which a thermal layer grows is the most significant part of the process. On this basis the transient conduction heat transfer is solved for a periodic process, and the period time is found to be a function of the degree of superheat, the heat flux and the liquid thermal properties. A simplified model for stability of nucleate pool boiling of liquid metals is postulated from which the minimum heat flux for stable boiling can be found as a function of liquid-solid properties, liquid pressure, the degree of superheat, and the cavity radius and depth. At relatively low heat fluxes, convection currents have significant effects on the period time of bubble formation. An empirical correlation is proposed, which takes into account the convection effects, to match the experimental results.
Pool Boiling Heat Transfer From Teflon-Coated Stainless Steel
Authors: Vachon R. I. , Nix G. H. , Tanger G. E. , Cobb R. O.
Published: February 2012

Stainless steel specimens have been coated with Teflon to produce nonwetted surfaces. The data indicate improved pool boiling heat transfer with a 0.0003-in. coating as compared to an uncoated specimen. However, thicker coatings were found to insulate the surface and impede the rate of heat transfer. Nonwetting is explained as the mechanism for enhanced heat transfer.
A Pressure Pulse Model for Two-Phase Critical Flow and Sonic Velocity
Authors: Moody F. J.
Published: February 2012

Pressure pulse transmission in a flowing mixture provides the basis for a theoretical formulation of two-phase critical flow and sonic velocity. Homogeneous and separated phases are considered, showing that phase pattern plays an important role in pulse transmission. Graphs are presented for critical flow and sonic velocity of steam-water mixtures, based on no phase change or heat transfer across the pulse. The present model predicts most available data with homogeneous and separated phase patterns and suggests quality ranges for which each pattern applies.
Heat-Conduction Problems With Melting or Freezing
Authors: Cho S. H. , Sunderland J. E.
Published: February 2012

An exact solution is presented for the temperature distribution and rate of change of phase for a semi-infinite body where the change of phase occurs over a range of temperatures. The surface temperature is instantaneously changed to and held at a temperature different from the phase-change temperature range and the initial temperature. The transient temperature distribution and rate of melting are also determined for a finite slab in which one or two phase changes take place. The slab is initially at a constant temperature and the temperature of one face is instantaneously changed so that a phase change takes place. The other surface of the slab is insulated. An exact closed form solution is presented for the temperature distribution in the newly formed phase and Goodman’s integral technique is used to find the temperature distribution in the initially existing phase.
Statistical Estimation and Elimination of Thermal Network Model Errors
Authors: Browne B. H.
Published: February 2012

A new approach is developed for estimating and correcting digital thermal network errors based upon achieving statistical reconciliation between model predictions and observed results. The development is preceded by a review of the general theory of thermal networks and the development of the canonical forms of networks and their error models. Application of the technique promises improved thermal prediction accuracy of complex systems using simplified network models.
An Experimental Study of Ammonia as a Reactive Transpiration Coolant—Porous Body Cooling
Authors: Gorton R. L.
Published: February 2012

The effect of ammonia as a reactive coolant in porous body cooling was studied experimentally. Energy rejection to the ammonia coolant flowing through an electrically heated porous nichrome plate was measured. The energy absorption due to ammonia dissociation was determined and was found to account for up to 65 percent of the total energy absorption. System variables were chosen to be in the range of interest to transpiration cooling applications.
Local Temperature Variations of a Transpiration-Cooled Wall Due to Radiant Heating
Authors: Anderson J. E.
Published: February 2012

When the porous wall of a transpiration-cooled device is subject to a radiant heat flux, the maximum temperature of the solid wall material rises above the average temperature of the gas at the wall. A model of this phenomenon amenable to theoretical analysis is considered. Calculated results, in terms of the temperature difference between the solid and the gas, are presented in terms of five parameters: The dimensionless blowing parameter, which depends on the size of the holes in the porous wall; the porosity of the wall; the ratio of solid to gas thermal conductivity; the front-surface thermal boundary layer thickness; and the ratio of radiant to total heat flux to the wall.
Temperature Distributions in Laminar Flat Plate Shear Flow
Authors: Emery A. F. , Brettman K. F.
Published: February 2012

An approximate solution to the heat transfer coefficient on a flat plate in a linear shearing flow is given. It is shown that high shearing rates may significantly increase the local heat transfer coefficients.
Convective Instabilities in Fully Developed Flows
Authors: Sherman M.
Published: February 2012

This paper considers the possibility of inducing a convective secondary flow in the fully developed channel flow of a quasi-incompressible (Boussinesq) fluid. Instabilities of this type can only occur when the temperature gradient in the direction of the body force exceeds a certain critical value. This temperature gradient is proportional to the Rayleigh number of the fluid. We find that for channels of arbitrary cross section, the critical Rayleigh number is Rc ≥ 1360 (h/d)4 where h is the arbitrary channel’s maximum dimension in the body force direction and d is the diameter of an equal area circular channel. For two special geometries it is possible to improve the foregoing lower bound estimate to the critical Rayleigh number. In a circular channel Rc ≥ 3450 and in a square channel Rc ≥ 2480.
Electrohydrodynamic Condensation Heat Transfer
Authors: Choi H. Y.
Published: February 2012

This paper describes the results of an investigation of the effects of strong electric fields on condensation heat transfer. Freon-113 is condensed inside a vertical tube, and the condensate interface is stressed by a radial d-c field. The effect of the field on condensing heat transfer can be summarized as follows: (a) The condensing heat transfer coefficient increases significantly with the electric field; (b) the increase is related to the appearance of instability waves at the liquid film interface. These effects suggest that the average liquid film thickness is significantly reduced at high electric field intensities. A tentative correlation is presented for the high field data. The correlation is presented in terms of modified Nusselt and Rayleigh numbers in which the characteristic length is the most unstable wavelength in the system, and the driving force acting on the film is an equivalent electrohydrodynamic force.
Heat Transfer in an LTV Falling Film Evaporator: A Theoretical and Experimental Analysis
Authors: Kroll J. E. , McCutchan J. W.
Published: February 2012

Two slightly differing mathematical models were developed to describe the heat transfer in the long tube vertical falling film process. The process was investigated experimentally with a 3/4 in. dia tube for various lengths up to 13 ft, for flow rate Reynold’s numbers from 1000 to 13000, for temperature differences of the order of 20 deg F, and for vacuum conditions down to 160 deg F. A comparison of theoretical and experimental results was made and was found to be in good agreement; that is, within 10 percent.
Heat Transfer From Spheres Into Subcooled Liquid Sodium During Forced Convection
Authors: Witte L. C. , Baker L. , Haworth D. R.
Published: February 2012

Heat transfer rates from 1/2-in-dia spheres were measured as the sphere moved through a pool of subcooled liquid sodium. Measurements were made at atmospheric pressure and with sodium at 572 and 842 deg F. Sphere temperatures ranged up to 3600 deg F. Heat transfer rates up to 3.6 × 107 Btu/hr sq ft were calculated from the experimental data. It was shown in this study that large amounts of subcooling in the liquid sodium and motion of the sphere tend to prevent the formation of vapor at the surface of high-temperature spheres. These experimental data were correlated by a theory in which it was assumed that highly superheated liquid sodium would be in contact with a high-temperature sphere.
Coupled Periodic Heat and Mass Transfer Through a Permeable Slab With Vapor Adsorption
Authors: Jeric M. Z. , Nottage H. B.
Published: February 2012

Periodic flow of heat and mass, with temperature and vapor-concentration cycles applied at one surface of a permeable slab, is solved analytically for an adsorption-desorption isotherm linear with vapor concentration and with temperature. Magnitude of the energy-transfer coupling effect is demonstrated for water vapor and fiberboard, where differences in time lags for heat and mass transfer at the slab surface opposite to the periodic input may produce an energy outflow when an inflow would be expected.
Transient Response of an Intrinsic Thermocouple
Authors: Henning C. D. , Parker R.
Published: February 2012

Where rapid heating is encountered, as in a prompt-burst nuclear reactor, a thermocouple with a rapid time-response is necessary to monitor the temperature of the specimen in question. Because all thermocouples have some mass, they cannot have an infinitely fast response. However, an intrinsic-type thermocouple has less thermal inertia than the usual welded-bead type. Thus it is a natural choice for the measurement of transient surface temperatures of conducting solids. In this report an analytical expression is obtained for the transient response of an intrinsic thermocouple. In support of the analysis, experimental data are presented which were obtained by means of a capacitor bank pulse-heating technique. It is concluded that thermocouple wires of small diameter and low thermal conductivity respond the fastest. As an example, a 1-mil constantan wire on a copper substrate produces 95 percent of the steady-state emf in 3 μsec.
Experimental Study of the Effects of an Ultrasonic Field in a Nucleate Boiling System
Authors: Schmidt F. W. , Torok D. F. , Robinson G. E.
Published: February 2012

The effect of an ultrasonic field on the heat transfer in a flash boiling system is reported. The amount of heat transfer per unit volume of fluid was found to be a function of the following parameters: liquid superheat, system pressure, and the impurities in the fluid. The introduction into the system of an ultrasonic field at a frequency of 26 kc and an electrical power input to the transducer of 40 w resulted in the formation of cavitation within the fluid. The presence of the cavitation under certain conditions resulted in a significant increase in the bubble turbulence in the system and the rate of heat transfer. The improvement was noted only when operating in specific ranges of the foregoing parameters and the fluid flow rate. The effects of fluid impurities were determined since both distilled and tap water were used as the working fluid.
Laminar Transfer From Isothermal Spanwise Strips on a Flat Plate
Authors: Sogin H. H.
Published: February 2012

The Rubesin-Klein-Tribus method is used to calculate rates of heat transfer by forced convection from two isothermal spanwise strips in tandem. The general results are applicable to either laminar or turbulent flow. Predictions of laminar transfer are based on Eckert’s step function. In experimentation, naphthalene cast in trays is used to simulate the isothermal strips while the inert material between them simulates the adiabatic wall. The velocities range from about 40 to 90 ft/sec, and the air temperature from 72 to 88 F. The boundary layer is shown to be laminar. The theoretical and experimental results are found to be in good agreement, confirming the calculation method and Eckert’s step function. The experimentation is extended to an array of several equally spaced strips in tandem. Effects of roughness and spanwise diffusion are noted.
Heat Transfer in Flow Through Rotating Ducts
Authors: Kuo C. Y. , Iida H. T. , Taylor J. H. , Kreith F.
Published: February 2012

Experimentally measured heat-transfer coefficients and visually observed flow phenomena for water flowing through an electrically heated rotating pipe with various inserts are reported. Convection heat transfer in flow through a rotating pipe or a rotating annulus was found to be an exceedingly complex mechanism which can not be treated adequately in terms of conventional parameters, but requires a detailed understanding of wave and vortex phenomena which were visually observed and photographed. Heat-transfer coefficients were measured in completely as well as partially filled flow channels. Three distinct flow regimes were observed in all cases; transition between regimes was found to depend on the rotational speed, but not on the axial flow velocity. Stationary vortexes and a counterrotational fluid motion were observed.
A Six-Part Survey: Rocket Heat-Transfer Literature
Authors: Irvine Thomas F. , Graham R. W. , Morrell G. , Turnacliff R. D. , Robinson J. H. , Englar K. G. , Deissler R. G. , Bartz D. R. , McManus H. N. , Soehngen Erich E.
Published: February 2012

The survey has been divided into the following parts: Rocket-Engine Heat Sources; Rocket Cooling Techniques; Nozzle Wall Materials; Variable Fluid-Property Effects; Predictions of Thermal Properties; Flow Separation and Acoustic Effects.
Heat Transfer and Effectiveness for a Turbulent Boundary Layer With Tangential Fluid Injection
Authors: Seban R. A.
Published: February 2012

Experimental results are presented for the effectiveness and for the heat-transfer coefficient for a film cooling system in which air was used both for the film and for the free-stream fluids. Injection occurred at a single tangential slot near the leading edge of the plate and the slot size was varied. All flows were turbulent and the injection velocities covered a range from much less to much greater than the free-stream velocity. Correlations are realized for both the effectiveness and for the heat-transfer coefficient and, as in the past experience with such systems, separate specifications are needed for injection velocities greater and less than the free-stream velocity.
Geometric Factors for Radiative Heat Transfer Through an Absorbing Medium in Cartesian Co-ordinates
Authors: Oppenheim A. K. , Bevans J. T.
Published: February 2012

Heat flux conveyed by diffuse radiation from surface A1 and A2 through an absorbing medium is expressed by the relation Q1−2=J1 ∫A1×A2f(l12)(cosθ1cosθ2/πl122)dA1dA2 where J1 is the radiosity of A1 (sum of the emitted, reflected, and transmitted flux per unit area), l12 is the radiation beam (the distance between surface elements dA1 and dA2), θ1 and θ2 are the angles between the radiation beam and the normals to the surface elements, and f(l12) is the function describing the absorption law. The foregoing four-dimensional integral is transformed into a sum of one-dimensional integrals for the cases of opposite-parallel and adjoining-perpendicular rectangles. The results are suitable for numerical integration with any total absorption law obtained from the actual distribution of monochromatic absorptivities over the whole spectrum.
The Influence of Bypass Channels on the Laminar Flow Heat-Transfer and Fluid Friction Characteristics of Shell and Tube Heat Exchangers
Authors: Test Frederick L.
Published: February 2012

This paper discusses the effect of tube bundle to shell clearance, mean oil temperature, mean water temperature, and oil flow rate on the shell-side heat-transfer film coefficients and pressure losses for laminar flow in unbaffled and cross-baffled heat exchangers. The results for cross-baffled heat exchangers can be correlated by considering the flow to be a combination of flows parallel to the tubes and across the tubes.
An Analytical Study of Laminar Film Condensation: Part 1—Flat Plates
Authors: Chen Michael Ming
Published: February 2012

The boundary-layer equations of momentum and energy are written in a modified integral form and solved for the case of laminar film condensation along a vertical flat plate. The analysis differs from previous works by employing the more realistic boundary condition of stationary vapor at large distances instead of zero velocity gradient at the interface. Solutions for both the liquid film and vapor boundary layer are given for the case μvρv ≪ μρ. Velocity and temperature profiles are obtained using perturbation method and the modified integral boundary-layer equations. The results show a significant negative velocity gradient at the interface as a result of vapor drag except for small values of kΔt/μλ. Theoretical heat-transfer coefficients are computed and found to be lower than previous theories, especially for low Prandtl numbers. Comparison with experimental heat-transfer data is given. The heat-transfer results are also presented in the form of an approximate formula for ease of application.
Heat Transfer by a Turbulently Flowing Fluid-Solids Mixture in a Pipe
Authors: Tien C. L.
Published: February 2012

Analysis is made on the heat transfer by a turbulently flowing fluid with suspended small solid particles in a circular pipe. Temperatures in the system are assumed to be less than about 1000 F, so that radiation effects are negligible. The loading ratio of solids to gas based on mass is less than or equal to one in the present investigation. The governing equations for the system are derived as two coupled linear equations. With approximations, the governing equations with their boundary conditions reduce to a form of the corresponding governing equation for the one-phase heat-transfer system. Computations of the solution are accomplished by use of the solutions in one-phase case. The final results are compared with existing experimental data and are discussed.
Analysis, Results, and Interpretation for Radiation Between Some Simply-Arranged Gray Surfaces
Authors: Sparrow E. M. , Gregg J. L. , Szel J. V. , Manos P.
Published: February 2012

A detailed analysis has been made to obtain both physical insight and numerical results for radiation between gray surfaces. In particular, it was desired to examine the common assumption that the incident radiation is uniformly distributed over a surface. To lift this assumption, the radiation problem must be formulated in terms of integral equations. The study was carried out for two simple configurations: Two plates sharing a common edge, and two parallel plates. Solutions of the governing integral equations were found for a wide range of geometric and radiative conditions. A detailed interpretation is made of the results, and comparisons with the predictions from the simplified theory of uniform incident radiation are presented.
Film-Boiling Heat Transfer From a Horizontal Surface
Authors: Berenson P. J.
Published: February 2012

Taylor-Helmholtz Hydrodynamic Instability and its significance with regard to film boiling heat transfer from a horizontal surface is discussed. It is shown that near the minimum film-boiling heat flux, the bubble spacing and growth rate is determined by Taylor Instability neglecting the effect of fluid depth and viscosity. Utilizing a simplified geometrical model, an analytical expression for the heat-transfer coefficient near the minimum in film pool boiling from a horizontal surface was derived. Combining this equation with the available correlation for the minimum heat flux yields an analytical equation for the temperature difference at the minimum, which defines the location of the minimum point. The above equations agree with the available experimental measurements made on n-pentane and carbon tetrachloride within ±10 per cent.
Transient Temperature in a Melting Solid
Authors: Sunderland J. E. , Grosh R. J.
Published: February 2012

A method of analysis is given for determining the temperature distribution in a semi-infinite, homogeneous solid initially at a constant temperature and then suddenly heated by convection so that a phase change occurs and the new phase is removed upon formation. The method appears applicable to problems involving melting, freezing, or sublimation and to situations where the environment temperature and heat-transfer coefficient vary with time. It consists of calculating the temperature before the phase change occurs, during the transient process of phase change, and after steady-state conditions are obtained if such is possible. During the transient process, a numerical or graphical method of solution may be used which is an extension of the Binder [1] method. Numerical results obtained with a digital computer are given for the case where the environment temperature and coefficient of heat transfer are constant and provide a method for determining the velocity and position of the moving phase front.
An Exact Solution of the Compressible-Flow Characteristics in Constant-Area Passages With Simultaneous Friction and Constant Heat Flux
Authors: Noyes R. N.
Published: February 2012

An exact solution is presented for the flow of a compressible fluid in a constant-area passage in which wall friction is present and the total temperature of the fluid rises linearly with distance through the passage. For fluid properties that are invariant with temperature, this is specifically the case of constant heat flux. From this exact solution, an approximate simplified form is derived that should be applicable to predicting flow performance for most types of operation of constant-area heat exchangers.
Buoyancy Effects in Forced Laminar Convection Flow Over a Horizontal Flat Plate
Authors: Mori Yasuo
Published: February 2012

Effects of buoyancy forces in a forced laminar convection flow over a horizontal flat plate is analyzed. It is shown that the solutions may be expanded into power series in Grx/Rex2.5 whose first terms express the solution for the purely forced convection flow. A numerical example is given to show the effects of Grashof number on the velocity profile, the temperature profile, and the Nusselt number.
Radiant Interaction Between Fin and Base Surfaces
Authors: Sparrow E. M. , Eckert E. R. G.
Published: February 2012

Consideration is given to the effects of mutual irradiation occurring between a fin and its adjoining base surfaces. The first part of the analysis deals with black surfaces. It is found that in the range of practical operating conditions, the fin heat loss is significantly reduced by the presence of the base surfaces. Additionally, the base surface heat loss may comprise an important part of the total heat loss from the system. In the second part of the paper, the formulation is extended to include selectively gray surfaces and arbitrary irradiation from external sources. This degree of generality leads to a complex mathematical system composed of several integral equations and a differential equation.
Entrance Effects in a Two-Phase Slug Flow
Authors: Moissis R. , Griffith P.
Published: February 2012

This paper describes quantitatively one stage of the flow development process in equipment working with two-phase mixtures. The kinetics of a Taylor bubble, as it rises behind a series of other bubbles in a gas-liquid slug flow, have been determined. The rise velocity of a bubble is expressed as a function of separation distance from the bubble ahead of it. Using this information, the pattern of development of bubbles which initially enter a tube at regular intervals is determined by means of finite difference calculations. The density and, to a first approximation the pressure drop, of the developing flow are then calculated from continuity considerations. The density distribution in the entrance region is found to be a function of flow rates of the two phases, of distance from the inlet, and of initial bubble size. Density calculated by the present theory is compared with experimental measurements by the present and other investigators. Theory and experiments are in good agreement.
Thermocouple Temperature Disturbances in Low Conductivity Materials
Authors: Beck James V.
Published: February 2012

The axisymmetric transient heat conduction problem of a thermocouple embedded in a low thermal conductivity material is analytically investigated. The thermocouple is positioned normal to a surface which is heated by a time-variable heat flux. The results of the analysis are presented as dimensionless curves for a variation of several dimensionless parameters. The analysis may be used to calculate: (a) The temperature of a thermocouple temperature measurement for a known heat flux. (b) The undisturbed temperature at the location of the thermocouple junction from the transient thermocouple measurement. (c) The undisturbed heat flux just before thermocouple from the thermocouple measurement. It is found that the temperature disturbances in the thermocouple reading due to the presence of the thermocouple itself may be very large. It is shown that in certain cases the disturbance could be as large as 50 per cent of the temperature rise. An example is given in which the disturbance reaches 700 deg F.
Transient, Laminar, Combined Free and Forced Convection in a Duct
Authors: Zeiberg S. L. , Mueller W. K.
Published: February 2012

Transient, laminar, combined free and forced convection in a duct is analyzed under the assumptions of constant fluid properties, and fully developed flow. The transient heating is taken to be a result of wall temperature variations; the wall temperatures vary linearly with the axial co-ordinate of the duct (this is shown to be the only permissible axial dependence, other than no wall temperature variation in the axial direction). Numerical results show that for certain combinations of the Prandtl and Rayleigh numbers, an oscillatory approach to steady state exists. This phenomenon can induce a large reduction of the Nusselt number (compared to steady state) during the transient period.
Unsteady-State Heat Transfer in Solids With Radiation at One Boundary
Authors: Fairall R. S. , Wells R. A. , Belcher R. L.
Published: February 2012

A method is developed for estimating the transient temperature on the surface of a slab initially at some uniform temperature and radiating to a sink at 0 deg R. Results of the calculations using finite difference techniques on an IBM 7090 computer are presented graphically in terms of dimensionless parameters.
Heat Transfer by Combined Forced Convection and Thermal Radiation in a Heated Tube
Authors: Perlmutter M. , Siegel R.
Published: February 2012

An analysis is made to study the heat exchange by combined forced convection and thermal radiation in a tube when there is a specified heat flux imposed at the tube wall. The gas flowing in the tube is assumed transparent to radiation, so that the radiation which is included takes place between the elements of the internal tube surface and between this tube surface and the environment at each end of the tube. The inside surface of the tube is a black emitter and the outside is assumed perfectly insulated. The heat-transfer coefficient for convection alone from the tube wall to the gas is assumed constant. The energy equation governing the heat exchange is solved by two methods which provide results that are in good agreement with each other. Numerical examples of the wall and gas-temperature variations along the tube show the influence of the system parameters such as inlet gas temperature, tube length, and convective heat-transfer coefficient. A simple method is outlined, which can be used under some conditions to obtain an approximate wall-temperature distribution.
The Fusion Times of Slabs and Cylinders
Authors: Baxter D. C.
Published: February 2012

Results for the time required to melt or freeze a slab or cylinder of a pure substance initially at the fusion temperature and with convection at the surface are presented. The “enthalpy-flow temperature” method of Dusinberre and Eyres is used, and the lumped equations solved on an analog computer. Correlated results are given for the ambient temperature ranges cT∞/L up to 2, and Nusselt number greater than 1. These represent an extension of the “no-capacity” solutions of London and Seban. The “enthalpy-flow temperature” method involves use of the dependent variables H(T)=∫0+TcdTandφ(T)=∫0TkdT and so reduces the essential nonlinearity at the fusion temperature to one easily handled in an analog computer simulation.
Prediction of Thermal Conductance of Metallic Surfaces in Contact
Authors: Fenech H. , Rohsenow W. M.
Published: February 2012

A mathematical analysis of a thermal contact is first carried out on an idealized shape of contact point. The thermal conductance is expressed in terms of the thermal conductivities of the metals and of the fluid filling the voids, the real area in contact, the number of contact points per unit area, and the volume average thickness of the void gaps. A method is given for the determination of the above physical properties of a contact. To use this method the following measurements are needed: Two recorded profiles, perpendicular to one another; and a Knoop hardness test on the softer of the two metals making the contact. The last part of the paper is devoted to the experimental verification of the assumptions made in the theoretical analysis and to the application of the method outlined for the case of an iron-aluminum contact. Good agreement was found between the predicted and measured conductance over a range of pressures from 90 to 2600 psi.
Several Magnetohydrodynamic Free-Convection Solutions
Authors: Cramer K. R.
Published: February 2012

The influence of transverse magnetic fields on the laminar free-convection flow of liquid metals over a vertical flat plate and between vertical parallel plates is examined for specific wall temperature variations and Prandtl numbers. The extent of influence on the flow and temperature fields is determined by the magnitude of a nondimensional influence parameter which is the ratio of the magnetic force to the buoyant force. In general, increasing the magnetic field strength decreases the magnitude of the velocity, wall shear, and surfaces heat transfer and increases the temperature throughout the fluid. Analytical results demonstrate that magnetic fields of practical strengths exert considerable influence on liquid metal free-convection flow fields.
Unsteady Laminar Film Condensation on Vertical Plate
Authors: Chung Paul M.
Published: February 2012

The heat transfer associated with unsteady film condensation is analyzed for a vertical plate. The unsteady state is considered to be created by the time-dependent variation of either the uniform wall temperature or the g-force field. From the perturbation-type theoretical treatment, a set of universal variables and functions is derived which describes the unsteady behavior of the film. The universal functions are evaluated and tabulated so that the deviation of the heat transfer from the instantaneous steady-state value can be computed readily. The effect of varying the fluid properties on the unsteady heat transfer is discussed.
Free-Molecule Tube Flow and Adiabatic Wall Temperatures
Authors: Sparrow E. M. , Jonsson V. K. , Lundgren T. S.
Published: February 2012

The processes of mass and convective-energy transport in free-molecule flow are shown to bear useful similarities with the process of energy transport by thermal radiation. These similarities have been applied as a basis for deriving the mass and energy transfer characteristics for free-molecule flow in a circular tube. The net mass flow through tubes of various length-diameter ratios has been calculated as a function of the pressures and temperatures at the inlet and exit of the tube. A throughflow may occur even if the inlet and exit pressures are the same, provided that a temperature difference exists. For a length-diameter ratio in excess of 45, a fully developed mass flow relation applies. The distribution of the adiabatic wall temperature along the tube length has also been determined as a function of system pressures and temperatures and of the tube dimensions. Rather large variations of adiabatic wall temperature may occur for long tubes. The throughflow of energy shows characteristics similar to the throughflow of mass.
Heat Transfer to Pneumatically Conveyed Glass Particles of Fixed Size
Authors: Depew C. A. , Farbar L.
Published: February 2012

The phenomenon of heat transfer to an air stream laden with solid spherical particles flowing up a vertical tube with constant heat flux was investigated experimentally and analytically. Two particle sizes, 30 and 200 microns in diameter, were employed. The air flow conditions were held constant at Reynolds numbers of 13,500 and 27,400 while solids were added up to gravimetric ratios of seven. The analytical treatment parallels available solutions for single-phase flow. An approximate solution was obtained under the assumption that the difference in the temperature of the two phases is small, and that the radial temperature profiles of the two phases in the fully developed region are similar. Qualitative agreement with the experimental results is obtained. Large changes in the local Nusselt number were obtained in the experiments using 30-micron particles, in contrast to small effects due to 200-micron particles.