bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical Modeling of Thermal Materials Processing Systems
Authors: Jaluria Yogesh 
Published: December 2021

Abstract
The numerical modeling of the heat and mass transfer and of the fluid flow processes in manufacturing, particularly in the thermal processing of materials, is discussed in this paper. Several important processes such as polymer extrusion, glass fiber drawing, chemical vapor deposition, and casting are considered in detail. The governing equations, the relevant boundary conditions and the basic approach to numerically model many of these processes are presented. The importance of material properties in an accurate mathematical and numerical modeling is brought out, along with the coupling between the process and the resulting characteristics. The concerns and computational difficulties that arise due to various aspects such as the non-Newtonian behavior of plastics, exponential temperature dependence of glass viscosity, complex geometry, free surface flow, conjugate transport, material movement, chemical reactions, and phase change are considered. Some of the important methods to treat these complexities are presented. A few typical numerical results are presented on some important materials processing systems.
Eulerian Finite Element Analysis of 3D Machining
Authors: Madhavan V. , Olovsson L. , Swargam S. C. , Agarwal R. 
Published: December 2021

Abstract
We describe here the development and testing of a capability for finite element simulation of practical machining operations such as turning and milling, using 3D multi-material, explicit dynamic, Eulerian finite element analysis. In these simulations the workpiece material and the air surrounding it are modeled using Eulerian finite elements and the flow of the workpiece material into the air as a result of the action of the Lagrangian tool can be freely tracked.
Tension tests and Taylor impact tests are simulated using the traditional Lagrangian approach as well as the Eulerian approach. Comparison of the results is used to understand the factors affecting the solution accuracy. Simulations of orthogonal machining using this technique show that the side flow of the chip is simulated realistically. Simulations of oblique machining with various rake and inclination angles confirm that the chip flow angle is independent of the rake angle. Inertial effects cause the chip flow angle to differ from the inclination angle as the weight of the chip increases. Simulations of turning and end milling show that chip formation and flow can be simulated ab-initio. The simulation capability described here can provide accurate results for various outputs of interest and is also computationally efficient, allowing a typical analysis to be completed within a day.
A Study of Multiple Heat Sources on a Flat Plate Heat Pipe Using Point Source Approach
Authors: Keng Tan Boon 
Published: December 2021

Abstract
An analytical approach has been employed to study liquid flows in an isotropic wick structure of a flat plate heat pipe with multiple heat sources so as to determine the optimum heat pipe performance. In this study, the heat sources have been modeled as point sources using the Dirac Delta function to describe the heat distribution. The two dimensional pressure and velocity distribution are shown and discussed. The study has been extended to locate the positions of the multiple heat sources for optimum heat pipe performance. The optimum performance of the heat pipe is accomplished when the minimum pressure drop is attained across the wick structure.
Modelling the Rolling Motion of a Momentum Driven Droplet
Authors: Khan Aman M. , Holdo Arne E. 
Published: December 2021

Abstract
Free surfaces, with their associated surface tension energy, play a prominent role in many areas of fluid dynamics. The motions of these free surfaces and the effects of the controlling forces become particularly relevant when considering small droplets or small scale flows in micro-structural domains. Surface tension, in conjunction with structural interaction (as characterised by the contact angle), may also give rise to tractions that are capable of driving the motion of the fluid (as seen in porous media).
The effects of surface tension on the momentum driven motion of a small droplet of honey were first investigated by Dussan and Davis (1974). The qualitative experimental observations made by these authors led to the formulation of a kinematic analysis in which the basic assumption was that the interface rolls onto or off of the solid substrate. In the present work we initially look at how numerical Computational Fluid Dynamic (CFD) modelling can be used to repeat the previous authors’ work, and subsequently, we use the basic model to extend their analysis.
The motion of a small droplet of honey (1 cm3), moving under the influence of gravity, is modelled. The droplet is initially at rest in a semi-hemispherical configuration upon a plane inclined at 30° to the horizontal. Massless computational particles are introduced in a semicircular configuration close to the droplet surface. The particles are at a constant radial distance from the centre of the droplet and are used to mimic dye or marker particles at the free surface. The motion of the droplet and associated particles, in time, is presented. The resulting motions are compared with existing experimental data (Dussan and Davis, 1974).
Using CFD modelling and marker particles we represent numerically the experimental work of Dussan and Davis (1974). Using CFD modelling, dimensional analysis and marker particles within the fluid domain gives an improved insight into the tractions and motions present within the droplet fluid flow.
An Investigation of Reactor Core Isolation Cooling (RCIC) Turbine Exhaust Line Dynamics at LaSalle Nuclear Generating Station
Authors: Ramsden Kevin B. , Randels Raubin 
Published: December 2021

Abstract
The RELAP5 Mod 3.1 computer code has been utilized to study the causes of exhaust line rupture disk actuation that occurred without indication of overpressure conditions. A series of cases have been investigated to determine the conditions in the RCIC upstream steam supply as well as the exhaust piping that would lead to dynamic behavior capable of causing exhaust system rupture disk failure. It has been demonstrated that the presence of moisture in the turbine and/or its immediate exhaust piping, are necessary to achieve the pressures necessary to fail the rupture disk. The upstream steam supply conditions can significantly influence the transient, particularly if saturated water is able to enter the turbine. Saturated water ingestion to the turbine can lead to significantly higher exhaust pressure behavior. The upstream supply conditions cannot, however, result in rupture disk failure if there is not water present in the turbine/exhaust line at startup. This paper discusses the modeling methods, as well as the results obtained from the computer simulation.
Analysis of Passive Water Hammer
Authors: Husaini Syed M. , Arastu Asif H. , Qashu Riyad 
Published: December 2021

Abstract
This paper presents a methodology for the calculation of the severity a type of water hammer called “passive water hammer”. The passage of a cold water column followed by hot saturated water through a restricting orifice causes a reduction in flow velocity and a corresponding increase in pressure. The term passive water hammer was given to this mechanism because there is no active flow intervention required for its initiation. This type of water hammer has been observed in heater drain systems of power plants. An example is given for the calculation of pressure surge and pipe segment forces due to this mechanism.
An Adaptive Domain Decomposition Scheme for Parallel Smooth Particle Hydrodynamics Regional Weather Model
Authors: Kumar Gopal N. 
Published: December 2021

Abstract
Smooth Particle Hydrodynamics (SPH) method is a lagrangian technique used to describe and model complex fluid flows. Being a lagrangian method, it is gridless and the particles themselves carry all the information relating to the flow. By nature of its formulation, SPH method can easily incorporate complex physics of particle interactions. This makes it an attractive candidate for modeling regional weather and weather forecasting. As the SPH method deals with particle interactions in a local sense, it is good for domain decomposition. This makes SPH ideal for parallel computations. The main bottleneck arises from the need to find neighboring particles to determine local interactions. Finding neighbors is achieved by sorting the particles based on some appropriate key value. In order to have high parallel efficiency, one would have to allocate the particles equally amongst the available processors for good load balancing. This calls for an adaptive domain reallocation and for a sorting methodology that is specifically tailored for this. This paper presents a new parallel sorting scheme that guarantees that the available processors have close to equal number of particles.
Cavity Pressure and Part Quality in the Injection Molding Process
Authors: Angstadt David C. , Coulter John P. 
Published: December 2021

Abstract
Extensive research has been conducted in an attempt to develop reliable models or indicators for determining product quality based on process information. Relationships between part quality and process variables such as nozzle temperature, hydraulic pressure and cavity pressure have been established using methods such as statistical process control, regression analysis and artificial neural networks. Ideally, these models would be used to determine part quality without direct inspection. If a level of confidence equivalent to that obtained by traditional methods (e.g., SQC) could be achieved, “quality by inspection” could be eliminated. Two drawbacks to these models are that they are specific to the machine/mold/polymer (M/M/P) combination being studied and they require a significant amount of “up-front” process data for model formulation. A method for “normalizing” pressure data obtained from a range of machine/mold/polymer configurations to yield essentially one curve or attribute denoting acceptable part quality would greatly enhance the utility of P-t data in a manufacturing setting. The objective of the present research is to examine the effects on the temporal cavity pressure due to changes in the mold geometry and to investigate methods for obtaining generic pressure data for various geometries. Cavity pressure data was collected using geometric inserts fitted into a standard ASTM tensile specimen cavity. The pressure data was analyzed to determine the correlation between cavity pressure and part quality for three part geometries studied. A discussion of the utility of the pressure is presented and an attempt is made to find a geometry independent cavity pressure attribute for use in determining part quality.
Experimental Analysis of Particle Filtration in Resin Transfer Molding of Preceramic Polymer Based Ceramic Composites
Authors: Erdal Merve , Ambrosoni Letizia A. 
Published: December 2021

Abstract
The study of particle filtration in resin transfer molding of liquid preceramic polymer (PCP) based ceramic composites with filler particles is the topic of our current research, in order to prevent particle filtering during impregnation and to achieve a uniform particle distribution within the composite. This study targets an experimental analysis of filtration that will be coupled to previously developed filtration models. For reliable filtration data, the properties of the particle-PCP suspension must be known (predictable) and the suspension quality reproducible. This paper presents the initial stage of the experimental work, which consists of standardization of particle-polymer suspension preparation and its characterization. A methodology for optimal (homogeneous suspension with low agglomeration) steric stabilization of polymer / SiC particle suspensions is presented. The results Blackglas™1 preceramic of the characterization of the suspensions through visual inspection (SEM) and rheological measurements are reported. With the achievement of well-dispersed, low viscosity suspensions with reproducible properties, our current work is in the adaptation of electrostatic spraying and laser particle counting technology for the detection of particle size distribution and concentration to be used in subsequent filtration experiments.
Application of a Bubble-Induced Turbulence Model to Subcooled Boiling in a Vertical Pipe
Authors: Mat Mahmut D. , Kaplan Yüksel , Ilegbusi Olusegun J. 
Published: December 2021

Abstract
Subcooled boiling of water in a vertical pipe is numerically investigated. The mathematical model involves solution of transport equations for vapor and liquid phase separately. Turbulence model considers the turbulence production and dissipation by the motion of the bubbles. The radial and axial void fractions, temperature and velocity profiles in the pipe are calculated. The estimated results are compared to experimental data available in the literature. It is found that while present study satisfactorily agrees with experimental data in the literature, it improves the prediction at lower void fractions.
Characterization of Permeability for Solid Freeform Fabricated Porous Structures
Authors: Erdal Merve , Ertoz Levent , Güçeri Selçuk 
Published: December 2021

Abstract
Fused deposition based solid freeform fabrication technique allows manufacturing of potential functional preforms for subsequent Resin Transfer Molding. In this study, the transport property (permeability) of solid freeform fabricated porous preform geometries are investigated. Specifically the effect of pore geometry and network on the permeability is sought. Wet (saturated) permeability experiments were performed for various pore geometries with different viscosity liquids. For all fluids and preform structures investigated in this study, the porous flow exhibited Darcian behavior. The permeability is affected by changes in order of magnitude of fluid viscosity, the effect considerably significant in low porosity preforms. Current work concentrates on dry permeability measurement and development of numerical permeability models for ordered pore geometries (as produced through SFF) that will be compared with experimental results.
Towards Controllability of Injection Molding
Authors: Kazmer David , Hatch David 
Published: December 2021

Abstract
Process control has been recognized as an important means of improving the performance and consistency of thermoplastic parts. However, no single control strategy or system design has been universally accepted, and molding systems continue to produce defective components during production. The capability of the injection molding process is limited by the thermal and flow dynamics of the heated polymer melt.
This paper discusses some of the difficulties posed by complex and distributed nature of the injection molding process. The flow and thermal dynamics of the process are analyzed with respect to transport and rheology. Then, two novel processing methods are described to enable in-cycle flow, pressure, and thermal control. Simulation and experimental results demonstrate effectiveness of these innovations to increase the consistency and flexibility in polymer processing. Such system design changes simplify the requisite control structures while improving the process robustness and productivity.
Crustal thickness of the Grenville orogen: A Mesoproterozoic Tibet?
Authors: Brudner Adam , Jiang Hehe , Chu Xu , Tang Ming 
Published: December 2021

AbstractThe Grenville Province on the eastern margin of Laurentia is a remnant of a Mesoproterozoic orogenic plateau that comprised the core of the ancient supercontinent Rodinia. As a protracted Himalayan-style orogen, its orogenic history is vital to understanding Mesoproterozoic tectonics and paleoenvironmental evolution. In this study, we compared two geochemical proxies for crustal thickness: whole-rock [La/Yb]N ratios of intermediate-to-felsic rocks and europium anomalies (Eu/Eu*) in detrital zircons. We compiled whole-rock geochemical data from 124 plutons in the Laurentian Grenville Province and collected trace-element and geochronological data from detrital zircons from the Ottawa and St. Lawrence River (Canada) watersheds. Both proxies showed several episodes of crustal thickening and thinning during Grenvillian orogenesis. The thickest crust developed in the Ottawan phase (~60 km at ca. 1080 Ma and ca. 1045 Ma), when the collision culminated, but it was still up to 20 km thinner than modern Tibet. We speculate that a hot crust and several episodes of crustal thinning prevented the Grenville hinterland from forming a high Tibet-like plateau, possibly due to enhanced asthenosphere-lithosphere interactions in response to a warm mantle beneath a long-lived supercontinent, Nuna-Rodinia.
When did the North Anatolian fault reach southern Marmara, Turkey?
Authors: Karabacak Volkan , Sançar Taylan , Yildirim Gökhan , Uysal I. Tonguç 
Published: December 2021

AbstractWe dated syntectonic calcites on fault planes from the southern branch of the western North Anatolian fault (NAF) in northern Turkey using U-Th geochronology. We selected strike-slip faults that are kinematically related to the current regional strain field. The isotopic ages cluster around different periods during the past ~700 k.y. The most prominent cluster peak of 510.5 ± 9.5 ka (1σ) is consistent with the maximum cumulative strike-slip offset data and tectonic plate motions measured by GPS data, highlighting the fact that the present configuration of the NAF in the southern Marmara region started at ca. 500 ka or earlier. These new isotopic ages, combined with previous considerations of regional tectonics, reveal that faulting along the western NAF initiated primarily in the southern Marmara region at least a few hundred thousand years earlier than the timing suggested for the northern branch of the western NAF. This study presents an innovative approach to constrain the timing of initiation of currently active fault segments along the NAF in southern Marmara. U-Th geochronology of fault-hosted calcite thus has a wide application in determining absolute ages of fault episodes in wider shear zones along plate boundaries.
Mimetics of the Arg-Gly-Asp Sequence: Synthesis and Studies of the Antiaggregative Properties
Authors: Gribovskaya O. V. , Martinovich V. P. , Rodko E. V. , Rasyuk E. D. , Ryabtseva T. V. , Golubovich V. P. 
Published: December 2021

Abstract—
It is known that the Arg-Gly-Asp sequence in the fibrinogen molecule is key in binding to the receptors on the surface of platelets. We searched for the compounds which were able to inhibit the binding and synthesized the following analogs of this sequence: 2-acetoxybenzoyl-Arg-βAla-Asp, 4-piperidinecarbonyl-βAla-Asp, and 4-aminobezoyl-βAla-Asp. These compounds were shown to inhibit the platelets aggregation in a different degree. The 2-acetoxybenzoyl-Arg-βAla-Asp analog demonstrated the highest inhibitory activity. A decrease in the expression of the CD62p and CD63 markers on platelets was also found after the action of the Arg-Gly-Asp analogs, confirming the ability of these compounds to block the fibrinogen binding sites for the GP IIb/IIIa glycoprotein receptors.
Molecular Dynamics Study of Escherichia coli Thymidine Phosphorylase in a Complex with 3'-Azidothymidine Inhibitor and Phosphate
Authors: Timofeev V. I. , Zhukhlistova N. E. , Kuranova I. P. 
Published: December 2021

Abstract—Using a molecular dynamics method, the state of the dimeric thymidine phosphorylase molecule fromEscherichia coliin a complex with noncompetitive enzyme inhibitor 3'-azidothymidine and phosphate ion was studied on a trajectory of 50 ns. Previously obtained atomic coordinates of a complex of thymidine phosphorylase with azidothymidine and sulfate at a resolution of 1.52 Å were used as a starting model. It was demonstrated that both subunits of a dimeric enzyme molecule function asynchronously in a given time interval; moreover, each subunit maintains an open conformation. It was found that the nature of ligand at the nucleoside center affects the binding strength of phosphate in the phosphate center. In a complex with an inhibitor, both ligands over the entire time interval remain bound to the enzyme, while the release of phosphate from the active center is observed when simulating the behavior of thymidine phosphorylase in the presence of phosphate and thymidine substrate. The stabilizing effect of azidothymidine on phosphate binding is consistent with the behavior of azidothymidine as a noncompetitive inhibitor of thymidine phosphorylase.
Heavy metal toxicity and mortality—association between density of heavy metal bands and cause specific hospital admissions and mortality: population based cohort study
Authors: Martikainen Pekka , Korhonen Kaarina , Tarkiainen Lasse 
Published: December 2021

AbstractObjectiveTo assess the association between area level density of heavy metal bands and cause specific hospital admissions and mortality.DesignLongitudinal register based cohort study.Setting311 municipalities in Finland.Participants3 644 944 people aged 15 to 70 residing in Finland at the end of 2001.Main outcome measuresHospital admission and mortality from all causes, internal causes, alcohol attributable causes, accidental injury and violence, suicide or self-harm, and mental health related causes. Appendicitis and toxic effects of metals were negative control outcomes.ResultsDuring 50.4 million person years of follow-up in 2002-17, 4 237 807 person years with hospital admissions were observed and 221 912 individuals died. Mortality in municipalities with a moderate density of heavy metal bands (<5.7 per 10 000 inhabitants) was lower than in municipalities with no heavy metal bands. Hospital admission rates were lower in municipalities with heavy metal bands compared with those with none. These associations could be explained partly by differences in the sociodemographic characteristics of residents in these municipalities. After adjustment for individual characteristics and area level cultural and economic characteristics—proportion of the population with no religious affiliation, unemployment rate, and per capita expenditure on culture and education—large cities with a high density of heavy metal bands (8.2-11.2 per 10 000) showed a mortality advantage (hazard ratio 0.92, 95% confidence interval 0.88 to 0.96). In contrast, the association for hospital admission was fully attenuated (incidence rate ratio 0.99, 95% confidence interval 0.92 to 1.06). The cause specific analysis showed similar results, with the association most pronounced for alcohol attributable mortality (hazard ratio 0.83, 95% confidence interval 0.75 to 0.93 for cities with a high density of heavy metal bands) and alcohol attributable hospital admissions (incidence rate ratio 0.84, 95% confidence interval 0.74 to 0.97 for cities with a high density of heavy metal bands) in the fully adjusted models. No association with heavy metal band density was found for the analysis using appendicitis as a negative control outcome.ConclusionsThe study found no evidence for adverse health outcomes with increasing density of heavy metal bands. Cities with a high density of heavy metal bands showed slightly lower rates of mortality and of hospital admissions for alcohol related problems and self-harm. Although residual confounding remains a problem in observational studies, vibrant local heavy metal scenes—comparable to many other forms of cultural capital—might help to promote health through healthier lifestyles, better coping mechanisms, and a stronger sense of community.