bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Tomographic Image Reconstruction Method: Using a Hybrid Genetic Algorithm
Authors: Lyons Donald P. , Kihm Ken D. 
Published: July 2023

Abstract
A new tomographic image reconstruction method is introduced using a hybrid genetic algorithm. Both traditional genetic algorithms and a hybrid genetic algorithm associated with the concurrent simplex method are described and the merits of each are discussed. For the purposes of discussion, results from simple axisymmetric phantom test data are shown for the traditional and the hybrid genetic algorithm approaches. This new methodology shows the potential of alleviating difficulties with existing tomographic algorithms under the constraint of limited projection data.
Stress Analysis and Design Improvement for Commercial Vehicle Frames With Bolted Joints
Authors: Kim Yoon Young , Kim Jin Gon , Choi Seok Hwan 
Published: July 2023

Abstract
Structural failures such as crack initiation often arise near the bolted parts of the side member and trunnion bracket of some commercial vehicles. To prevent these problems, a designer should be able to analyze with confidence the bolted joints of the structures, and this will require a reliable and practically simple bolted joint modelling technique. Once the modelling technique is established with experimental verification, the key design varibles must be identified in order to alleviate the level of the stress concentration near the problem region.
The purpose of this paper consists of two major parts: the establishment of a simple and practical bolted joint modelling technique and the determination of the key design variables for design improvement. Utilizing the established joint modelling technique, a number of finite element calculations are carried out for the analysis of the system consisting of the vehicle side member and trunnion bracket. The numerical results have indicated that the torsional rigidity of the frame cross section and the trunnion bracket size are critical design variables.
Vibration Transmission Characteristics of Helical Gear System With Lead Error
Authors: Park Chan Il , Lee Jang Moo 
Published: July 2023

Abstract
Nowdays reduction of gear noise in power transmission is very important, because the noise regulation is severe and demand of customer on noise is increased. To reduce gear noise, it is necessary to understand the vibration transmission characteristics of helical gear system. In this work, we designed test rigs for study of vibration transmission characteristics. By using these test rigs, root strain, rotational gear vibration, bearing vibration and sound pressure level are measured under varying rpm and torque. The frequency characteristics of rotational gear vibration and gear noise on the effect of lead error are discussed. Also, the relationship between gear vibration, bearing vibration and sound pressure level is discussed.
A Method to Predict the Precipitation Hardening Response of a Particle Strengthened Aluminum-Lithium Alloy
Authors: Fragomeni James M. , Hillberry Ben M. 
Published: July 2023

Abstract
Aluminum-Lithium alloys offer some attractive benefits over conventional aluminum alloys for aerospace structural applications. The benefits for the aerospace community include a weight-saving improvement as well as an increase strength and elastic modulus. The addition of lithium to aluminum increases the strength through heat treatment by a precipitation hardening process. This document describes an approach or method for predicting the precipitation hardening response for aluminum-lithium alloys using a given minimum number of experimental tests. The overall approach is based on the dislocation mechanics, particle coarsening, thermodynamics, and particle strengthening mechanisms applicable to precipitation hardened alloys. The method eliminates the need to know or determine several of the microstructural constants required for predicting the precipitation hardening response of a particle strengthened alloy. Thus, using the aluminum-lithium demonstration alloy, a minimum number of four tensile tests was utilized to predict the variation in strength with aging time, aging temperature, and composition, for the underaged, peak-aged, and overaged conditions.
Pulse and Power Three-Phase Plasma Generators, Possible Applications
Authors: Rutberg Ph. G. , Kolikov V. A. , Laskin B. M. , Safronov A. A. , Polovtsev I. S. 
Published: July 2023

Abstract
The existence of plasma generators with the ability to fit the requirements of different technological processes appears to be the basic point for the introduction of modern plasma systems. The use of plasma heat is one of the most promising areas for development in the chemical industry. Considerable intensification of chemical processes allows for reduction of the reaction area and processing time These factors allow creation of reactors with small overall dimensions, higher capacity and with more attractive economic characteristics.
Modeling of Thermal Treatment of Solid Wastes in Electric Arc Melters for Material Recovery
Authors: Wenger Ashley K. , Farouk Bakhtier , Wittle J. Kenneth 
Published: July 2023

Abstract
Processing hazardous solid wastes in a DC are melter offers several advantages over other competitive methods, including the ability to vary the mixture chemistry without impacting the energy input. This decoupling allows the melter to be operated in conditions which enhance material recovery. Predictive models can play a useful role in suggesting feed additives or operating conditions to achieve this goal. This paper describes the use of a model to investigate metal recovery through volatilization in batch melters. Chlorinated species are shown to be an effective additive; the potential to simultaneously treat solid wastes and chlorinated organics is also confirmed. At similar oxidation-reduction potentials the amount of chlorine, irrespective of molecular form, is found to determine the volatilization, with a linear relationship between chlorine feed amount and volatilization. In more reducing conditions, greater metal volatilization occurs.
Corrosion Screening Tests With Ni-Base Alloys in Supercritical Water Containing Hydrochloric Acid and Oxygen
Authors: Boukis N. , Franz G. , Friedrich C. , Habicht W. , Ebert K. 
Published: July 2023

Abstract
Corrosion of reactor material during oxidation of hazardous organic waste containing chloride proceeds very fast and constitutes one major problem in SCWO applications.
The following Ni-base alloys were tested within the framework of our experimental program: Inconel 625 and 686, Hastelloy C-276, Nicrofer 5923 and 6025, and Haynes alloy 214. Test tubes were fabricated from these materials and exposed to SCWO conditions, without organics, at temperatures up to 600 °C and pressures up to 34 MPa.
Higher concentrated HCl solutions or the combination of oxygen and HCl cause strong surface destruction.
The corrosion measured was higher at lower temperatures and at higher pressures, if all other conditions remained constant.
The most severe corrosion — general corrosion with SCC and pitting — appeared at temperatures near the critical temperature, i.e. in the preheater and cooling sections of the test tubes. The corrosion products were insoluble in supercritical water and formed thick layers in the supercritical part of the reactor. Under these layers only minor corrosion occurred.
Spray Unsteadiness in Coaxial Airblast Atomizers
Authors: Hardalupas Y. , Tsai R.-F. , Whitelaw J. H. 
Published: July 2023

Abstract
Experiments have been performed with two coaxial atomizers, the first with an annular stream of air surrounding a central jet of water and the second a commercial airblast atomizer with air swirl. They quantify the deterministic unsteadiness of the droplet flow caused by the break-up process in terms of the mean and temporal fluctuations of the droplet surface area and provide links between atomizing air and liquid flow conditions and the amplitude of the droplet flow unsteadiness with distance from the nozzle exit. Time dependent measurements of droplet surface area in the spray were obtained by image processing of high speed photographs to detect the temporal fluctuations of the attenuation of the incident light and by a Mie scattering technique to detect the intensity of the light scattered by droplets illuminated by a laser sheet. Mie scattering was preferred, because of improved measurement accuracy and lower cost. The spray unsteadiness due to the break-up process was quantified in terms of the spectrum of the energy of the fluctuations of the droplet surface area within a frequency range associated with the break-up process. With the coaxial atomizer, the energy of the deterministic unsteadiness varied between 50% and 65% of the total energy of the spectrum and remained in the droplet flow at least up to 150 liquid jet diameters downstream of the break-up region and its energy increased with the reduction of the air or liquid flowrates, although higher energy was correlated with faster attenuation with the downstream distance from the exit plane, caused by the redistribution of droplets by the gas flow turbulence.
A Sectional Coupling Approach for the Simulation of Multi-Phase Reacting Flow in a Bent Reactor
Authors: Chang S. L. , Zhou C. Q. , Lottes S. A. , Bouillard J. X. , Petrick M. 
Published: July 2023

Abstract
Multi-phase reacting flows of a bent fluidized catalytic cracking (FCC) reactor have been simulated using the ICRKFLO code. A new sectional coupling approach has been developed to handle the complex geometry, which divides the reactor into two sections at the bend and performs computations for the two sections successively. The computational results show that the ICRKFLO code incorporated with the new sectional coupling approach can predict product yields very well compared with experimental data and can be used to identify critical processes and parameters which may be modified to improve the quality and quantity of the FCC products.
Effects of Moisture on the Dynamic and Impact Properties of Pultruded Glass-Epoxy Composite Beams
Authors: Barpanda Dev , Kowsika Murthy V. S. L. N. , Mantena P. Raju 
Published: July 2023

Abstract
The pultrusion manufacturing process offers an increased market potential for the cost-effective production of high modulus and light-weight composite structural elements such as beams, trusses and stiffeners. These members must be qualified for performing over a wide range of in-situ conditions which include both static and dynamic loading under harsh environmental conditions. The interaction of these variables is expected to alter their dynamic and mechanical properties. To utilize the full potential of pultruded composites in structural applications, their response to environmental degradation must be thoroughly evaluated. In previous research, the effects of temperature, frequency, post-curing, along with the type and placement of fibers on the dynamic flexural properties of glass/epoxy and hybrid glass-graphite/epoxy pultruded composites were characterized. The sensitivity of damping and the glass transition temperature (Tg) to various levels of induced porosity and debonding agents was also investigated.
This paper presents the effects of moisture on the dynamic and impact properties of pultruded E-glass/epoxy (EPON 9500, a low Tg resin) composites with varying volume fractions. The dynamic mechanical analysis (DMA) technique was employed to investigate the degrading effects of moisture on the loss factor and Tg. Low-velocity impact tests were conducted on a similar set of specimens. An attempt has been made to correlate the impact characteristics in terms of crack initiation and propagation energies with the Tg and damping. Results indicate a lowering of the glass transition temperature with increasing moisture content along with an increase in the loss factor; which could be attributed to factors such as plasticization of the polymeric matrix, microcracks and debonding. This was accompanied by a reduction in the peak load to failure, initiation and propagation energies during impact. A reduction in the width of the glass-transition region was observed with an increase in moisture content, which is expected to have a detrimental effect on the long-term application of these pultruded composites.
Steady State Flow Between Two Rotating Cones
Authors: Ponsonnaille O. , Ouibrahim A. 
Published: July 2023

Abstract
The flow between two rotating cones has been widely considered for a best understanding of the performances of the centrifuges of type to plates which have applications in the alimentary industry.
Most of the theoretical investigations have considered the solutions of the flow between two rotating cones either by linearizations of the Navier Stokes equations, or by approximations from analysis of the different associated nondimensional flow parameters (such as Reynolds, Taylor, Rosby and Eckman numbers). In this work, the whole Navier Stokes equations are considered in such a flow and the solutions found by postulating the unknown velocity field components and the pressure as functions series. The three components of the velocity field are determined.
Experiments have been conducted in order to validate the theoretical results. L.D.A. velocity field measurements of the axial and tangential components have shown an agreement with the corresponding theoretical results.
Nonlinear Flow Properties of Viscoelastic Surfactant Solutions
Authors: Fischer Peter , Rehage Heinz 
Published: July 2023

Abstract
This contribution gives a quantitative description of nonlinear rheological properties of viscoelastic surfactant solutions. Therefore we compare the experimental observed rheological properties with the theoretical proposed material functions of the Giesekus model. A complete description of the linear and nonlinear properties is accessible especially by keeping the model’s free parameter constant. Further several empirically relations are automatically derived from the Giesekus model.
Viscoelastic Properties of Electrorheological Fluids
Authors: Choi Youn D. , Kim Sang G. 
Published: July 2023

Abstract
Electrorheological (ER) fluid’s storage shear modulus (G’) and loss factor (η) have been directly measured using small amplitude forced oscillating rheometer as a function of oscillating frequency, strain amplitude and applied electric field. Two types of experiment were performed; (a) frequency sweep and (b) amplitude sweep. Two kinds of sample were employed for this experiment; cornstarch in corn oil and zeolite particles in silicone oil.
The storage shear modulus (G’) was a strong function of driving frequency. Generally, G’ increased with driving frequency. On the other hand, the loss factor (η) was not well behaved as storage modulus, but as the driving frequency increases η slightly decreases was the trend of the material’s characteristics.
Also G’ was a strong function of strain amplitude. Generally, G’ decreased with increasing strain, but η increases slightly with increasing strain amplitude. For G’, cornstarch in corn oil ER fluid has higher values than zeolite based fluid as we increased the applied electric field. On the other hand, zeolite based fluid has higher values for η.
There is a reasonable agreement between theory and experiment.
Valve Stiction in Reciprocating Compressors
Authors: Prasad B. G. Shiva , Panayil Daniel 
Published: July 2023

Abstract
Stiction is a common phenomenon observed in day to day life. It also plays an important role in determining the dynamics and reliability of reciprocating compressor valves. However, researchers in the field of compressor technology have paid very little attention for assessing its effects, let alone for understanding the basic mechanisms responsible for its occurrence. Fortunately or unfortunately, it is also a problem of serious concern in magnetic recording devices, and researchers in the area of tribology have done comparatively detailed studies for understanding the same. Those studies have blamed molecular attraction, surface tension, viscous forces and micro capillary evacuation as the underlying causes for this phenomenon.
This experimental investigation concentrated mainly on identifying the dominant parameters and understanding the way they influence valve stiction. Experiments were conducted to quantify stiction in the case of a compressor valve, which was later modified and shown to reduce its effect.
Geometric Design and Analysis of an Axial Vane Rotary Compressor
Authors: Orndorff Raymond L. , Thompson Gregory J. , Smith James E. 
Published: July 2023

Abstract
Demand for smaller and more fuel efficient vehicles has brought about the need for smaller and lighter automotive air conditioning compressors. A relatively new rotary mechanism has the potential to fulfill this need. The mechanism is comprised of stators containing toroidal cams, vanes, and a rotor. The rotor contains equally spaced slots for the vanes to slide through.
Cam profiles are investigated to determine the desired vane motion for high speed application. Analyses are used with varying geometries to determine the effect of the geometric parameters on compressor performance. It was found that up to 90% of the vane’s frictional power losses could be avoided by allowing the cams to rotate. Volumetric efficiency could be increased by locating the cam lobes close to the rotor to form a dynamic seal. The bearing analysis found that with a certain numbers of lobes and vanes, the bearing loads are theoretically non-existent.
Exergy-Economics of a District Heating System
Authors: Cornelissen R. L. , Hirs G. G. , Lie A. B. K. , van Steenderen P. 
Published: July 2023

Abstract
The objective of this paper is to define the exergetic pay back period. This period can be used for energy efficient systems as part of a more general assessment also including financial aspects. For the conservation of the exergy of natural resources investments with a shorter exergetic pay back period will be preferable. To determine exergy savings of exergy efficient systems the exergetic life cycle assessment has been used.
As an example a district heating system in combination with a cogeneration plant based on natural gas has been selected. The irreversibility taking place during the life cycle of the system due to the construction, operation, dismantling and waste processing is determined and compared with domestic central heating also based on natural gas. The analysis has been performed for four alternative district heating systems. The exergetic pay back period, defined as additional exergy invested divided by exergy saving, is shown to be between 0.07 and 1.2 years. The life cycle exergy saving varies from 24% to 49%, mainly depending on the density of the distribution system. In addition the differences in exergy saving are due to the fact that the small scale alternatives have a smaller gas turbine, which has a lower exergetic efficiency when compared with the big scale projects.
There is no direct relation between the exergetic and financial pay back period in this study. However the financial pay back period is roughly one order of magnitude higher than the exergetic pay back period. From this can be concluded that heat distribution systems with exergetic pay back periods of more than one year have unacceptable financial pay back periods.
An Intuitive and Unified Approach to Teaching Thermodynamics
Authors: Çengel Yunus A. 
Published: July 2023

Abstract
In this paper a “physical” or “intuitive” approach is presented as an alternative to the current “formula based” approach to learning thermodynamics. The new approach is intended to keep the students in touch with the physical roots of the problem at all times, and it is based on the following four fundamental physical relations applied to the system being analyzed:
Mass balance: Mass change = Mass transfer
Energy balance: Energy change = Energy transfer
Entropy balance: Entropy change = Entropy transfer + Entropy generation
Exergy balance: Exergy change = Exergy transfer − Exergy destruction
The relations above are easy to remember and they are applicable to any kind of system undergoing any kind of process. Therefore, they can serve as the starting point for any kind of thermodynamic problem. In their present form, they make physically meaningful strong statements about the fundamentals of thermodynamics that mass and energy are conserved, entropy is generated, and exergy is destroyed during a process. They are sufficiently short to be used as formulas, and they can be used in place of numerous complicated first and second law relations provided that the mechanisms of mass, energy, entropy, and exergy transfer are well-understood.
In this paper we attempt to demonstrate that the basic principles of thermodynamics can be taught with this intuitive and unified approach faster and better. This approach also instills a solid and long-lasting understanding of thermodynamics in students. The proposed approach is intended to supplement the current approaches instead of replacing it. It is most suitable during initial stages of study of energy, entropy, and exergy to establish the physical reasoning behind the formulas, and to help students develop a physical feel. The approach naturally leads into the convenient formula-based approach when the students reach that maturity.
Introduction of Exergy Concepts Using Intuitive Methods
Authors: Petrescu Stoian , Petrescu Valeria , Harman Charles M. 
Published: July 2023

Abstract
Exergy or availability concepts in steady flow are presented in an intuitive manner through use of physical models and accompanying property diagrams. The concept of exergy is explained through the use of reversible steady flow shaft work. The Gouy -Stodola theorem is proven and the processes illustrated using property diagrams. Finally, a comparison is made of the Carnot cycle operated as an engine, as a refrigerator and as a heat pump and exergetic efficiencies are shown for each. The exergetic and energetic Sankey balance diagrams for each of the three cycles are combined and compared to show the similarities and differences in the use of the exergetic method.
Early Introduction of Entropy Concepts in the First Undergraduate Course in Thermodynamics
Authors: Smith Joseph L. 
Published: July 2023

Abstract
A new introductory course in mechanical engineering thermodynamics is described. The course develops the basic concepts as natural extensions of the students previous experience. The first law and the second law are developed simultaneously and with equal emphasis. Entropy, entropy transfer and entropy generation are introduced in a manner analogous to the introduction of energy, energy transfer and generation of heat. Extensive use is made of isolated systems for analysis so that all relevant relations are systematically identified. The PVT, energy and entropy constitutive relations for subsystems are presented separately from the first law and second law relations for a given problem. With the early introduction of entropy, all of the constitutive relations, including entropy, are described at the same time. The concept of mechanical-to-thermal cross coupling within the constitutive relations is introduced and related to the Maxwell-relation partial derivatives. The energy conversion requirement for cross coupling is developed. Control volume and flow system relations are developed from closed system relations in a conventional manner. The course ends with a description of the models for several important energy conversion plants and a discussion of the reason that all practical plants are flow systems.