bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling and Simulation of a Balanced Vane Pump
Authors: Giuffrida A. , Lanzafame R. 
Published: November 2021

Abstract
Literature concerning balanced vane pumps is fairly rich but covers solutions usually for power steering applications.
The pump considered and modelled in this work presents fixed displacement, pressure balanced rotor like in the ones used for power steering but is different from them since the pumping effect of the chambers under each vane is not wasted as if the pump had a higher displacement under the same conditions.
Beginning from the real geometry of the pump, this work presents the mathematical model and its simulation developed in AMESim.
A Novel Approach to Active Vibration Isolation With Electrohydraulic Actuators
Authors: Zhang Yisheng , Alleyne Andrew 
Published: November 2021

Abstract
This paper presents a novel reformulation of the standard active vibration control problem for large systems to take advantage of the natural dynamics of a particular type of actuator: the electrohydraulic actuator. The standard linear vibration control problem set-up is followed by details of the limitations to this standard approach for electrohydraulic systems. This root of the problems lies in the attempt to utilize the electrohydraulic actuation system to provide a particular force. Previous work (Alleyne & Liu, 1999) has shown the inherent limitations to force tracking for these systems. To circumvent the limitations, the problem is reformulated as a velocity tracking one, which lends itself naturally to the dynamics of electrohydraulic systems. Subsequently, a SISO controller can be readily designed for the velocity tracking problem using standard controller design tools. Although the controller design is relatively standard, experimental results are given which demonstrate the efficacy of the problem reformulation.
Hydraulic Emulation of Injection Moulding
Authors: Guerrier Paul K. , Edge Kevin A. 
Published: November 2021

Abstract
The control of injection moulding is an active area for research. The inject phase of the moulding process which includes filling and packing is of particular importance. New control strategies have traditionally been evaluated either in simulation or through full scale testing. Both methods have advantages and disadvantages. This paper details the hydraulic load emulation of the filling and packing phases using the hardware-in-the-loop technique which is a compromise between these two methods. With suitable controller design successful load emulation is demonstrated.
Robust Nonlinear Control of a Novel Indexing Valve Plate Pump
Authors: Zhang X. , Nair S. S. , Manring N. D. 
Published: November 2021

Abstract
A robust adaptive pressure control strategy is proposed for a novel indexing variable-displacement pump. In the proposed approach, parametric uncertainties and unmodeled dynamics are identified to the extent possible using a model free learning network and used to de-couple the dynamics using physical insights derived from careful reduced order modeling. The swash plate motion control is then carefully designed to provide the desired pressure response characteristics showing improved performance with learning. The proposed control framework and designs are validated using a detailed nonlinear simulation model.
New Type of Hydraulic Rotary Actuator; Development and Application in a Large Telerobotic Manipulator System
Authors: Haas John R. 
Published: November 2021

Abstract
This paper describes a new type of hydraulic rotary actuator specifically developed to provide precision motion control in a very large, man rated, underwater telerobotic manipulator system. The high pressure, high torque rotary actuators are hydrostatically balanced, provide continuous rotation, constant torque output, exhibit minimal “stick-slip” and zero backlash. It is believed that the combination of features and the performance exhibited by these actuators represent an improvement in actuator technology to such an extent as to make projects previously determined unfeasible, now practical. Features of particular design value are a very large diameter through bore, and a truly modular design permitting use as an integral structural member. This paper will address design rationale, operating principles, key design features, product development highlights, an astronaut trainer case study, future development and potential applications.
Heating Effect of Pulsating Flow in Hydraulic Hoses
Authors: Ijas Mika J. , Ellman Asko U. 
Published: November 2021

Abstract
Some hydraulic actuators operate periodically. The periodic motion led to pulsating pressure in a hose. Pulsating pressure in the hoses led to problems with reliability of hoses and fittings. When there is high pressure oscillation in the hose, the whole hose arrangement vibrates and strains structure of the hose. If the moving hose touches somewhere the friction of abrasion warms the hose. On the other hand the hose bloats periodically all the time because of the pressure oscillation. When the hose bloats deformation of the rubber and the hose structure rises temperature. There are longitudinal and radial motions between hose linings and hose reinforcements so the friction rises temperature of the hose. The static pressure loss and the oscillation of the hose increase the temperature of the hose.
This paper concentrates to study how pressure oscillation and the hose bloating rise temperature of the hoses. The examinee hoses were measured by three different measurement ways. By means of a servo valve the pressure oscillation was produced to the examinee hoses. The all hoses (steel pipe, thermoplastic hose, heavy-duty with 2 reinforcement and extra heavy-duty with 3 reinforcement) were measured in the same time. The warming effect of abrasion was studied by help of a thermograph camera. The main result was that the warming was caused by the abrasion of the moving hoses.
A Novel Cooling Enhancement in Microelectronic Devices and Systems Using Oscillatory Impinging Air Jets
Authors: Chiriac Victor Adrian , Lee Tien -Yu Tom , Rosales Jorge Luis 
Published: November 2021

Abstract
A new cooling technique is proposed to simultaneously enhance the heat transfer and significantly reduce the prohibitive high temperatures usually reached by high-powered chips embedded in the last generation of packages. A comparison between flow and heat transfer characteristics for several types of microelectronic cooling arrangements was conducted using a numerical investigation. The maximum temperature and local heat transfer coefficient were determined on a single heated chip cooled by a channel flow, a steady impinging jet, and an oscillatory impinging jet at a Reynolds number of 600. A uniform inlet velocity was used for the channel flow calculation, and the upper and lower channel walls confined the jets. The calculation domain for the three simulations was identical; the steady jet configuration had an inlet jet width twice that of the unsteady jet.
The results indicate that the unsteady nature of the confined impinging jet greatly enhances the removal of heat transfer and reduces the high temperatures on the heated chip. The jet core becomes distorted and buckles beyond a critical Reynolds number of 600, which leads to a sweeping motion of its tip (stagnation point). As a result of the combined buckling/sweeping jet motion, the cooled area is significantly enhanced. A comparison between the unsteady impinging jet and the stationary impinging jet reveals that the heat transfer enhancement provided by the unsteady jet is at least two times better. A 25% cooling enhancement is observed when compared with the channel flow technique, yet the jet uses a flow rate 6.3 times lower, therefore a smaller pumping power.
The new cooling method does not require the incorporation of costly heat sinks and heat spreaders, or the unnecessary increase of pumping power/blower work, yet provides effective cooling at significantly reduced manufacturing/operating costs.
Computation of Natural Convection in Channels With Staggered Pin Fins
Authors: Boyalakuntla Dhanunjay S. , Murthy Jayathi Y. , Amon Cristina H. 
Published: November 2021

Abstract
In this paper we numerically analyze the possibility of using buoyant flow in the display panel of a laptop for electronics cooling. A three-dimensional channel with a staggered pin fin array is analyzed using an unstructured finite volume method. A uniform heat flux is applied on the inner wall; the outer wall is exposed to the ambient. A single periodic module is selected in the lateral direction. In the axial direction, however, the entire height of the display channel is considered. A range of Rayleigh numbers, panel inclinations and staggering arrangements are considered, and local and global flow and heat transfer results are obtained. The results are useful in designing augmented cooling schemes in portable electronics.
Thermal Design Analysis of Free Space Optical Interconnect (FSOI) Package Module
Authors: Chiriac Victor Adrian , Lee Tien-Yu Tom 
Published: November 2021

Abstract
A detailed thermal analysis for the FSOI (Free Space Optical Interconnect) technology incorporating VCSEL (Vertical Cavity Surface Emitting Laser) devices is performed using commercially available software. FSOI is one of the latest technologies used to transmit information at high-speed to/from a microprocessor to memory device via photons. Due to large heat dissipation and compact packaging design, temperature and associated thermal strain/stress could reach high values in the FSOI assembly, causing serious reliability and quality problems. Several design options are investigated in order to provide optimal thermal management for the FSOI module, and maintain VCSEL temperatures within reasonable limits. Convective cooling results for both organic and ceramic boards are investigated.
For designs with organic boards and without any thermal enhancement, the VCSEL temperature is well above the acceptable limit of 85°C at an ambient temperature of 30°C. The sequential inclusion of pedestals, board thermal vias, conductive rings between the optical modules, and metallic (Al) rods will significantly enhance the module thermal performance and reduce VCSEL temperature to 46°C. The presence of thermal vias in the organic board is critical; however, if the copper area percentage in the via block vs. the die area is above 3%, the VCSEL temperatures will remain constant.
The ceramic boards provide a good thermal solution, as VCSEL temperatures remain below the upper limit without including any thermal vias in the board. The comparison between the effect of convective air speed on FSOI with ceramic versus organic boards reveals that the VCSEL temperature is slightly higher (less than 2°C) for the case incorporating a ceramic board. However, the ceramic board has no thermal vias, compared to the 100% copper via block in the organic board. Hence, the same results are accomplished with much less complexity in the ceramic substrate design alternative. This option is suggested for manufacturing purposes, with improved thermal performances.
Design of Generator Acoustic Blanket and its Impact on Generator Cooling Performance
Authors: Tong Wei 
Published: November 2021

Abstract
Generator noise is one of the primary concerns in generator designs. The most cost-effective way to deal with the noise issue is to incorporate the reduction of sound pressure level in an early design stage. Once a generator is manufactured, it is often expensive to modify the design for reducing noise levels. For old generators with high sound pressure levels, an effective method to lower the generator noise exposure is to employ acoustic blankets wrapped on the generator external surfaces. However, with the application of acoustic blankets, heat transfer through generator walls can be greatly reduced, leading to the higher generator core temperature and higher generator cooling load.
This paper has addressed the design of generator acoustic blankets and its impact on generator cooling performance. The analysis has shown that the influence of acoustic blankets on the generator thermal performance is low or moderate. This suggests that the current acoustic blanket design is feasible. Results from this study have been used to optimize the blanket design.
A Natural Circulation Model of the Closed Loop, Two-Phase Thermosyphon for Electronics Cooling
Authors: Haider S. I. , Joshi Yogendra K. , Nakayama Wataru 
Published: November 2021

Abstract
The study presents a model for the two-phase flow and heat transfer in the closed loop, two-phase thermosyphon (CLTPT) involving co-current natural circulation. Most available models deal with two-phase thermosyphons with counter-current circulation within a closed, vertical, wickless heat pipe. The present research focuses on CLTPTs for electronics cooling that face more complex two-phase flow patterns than the vertical heat pipes, due to closed loop geometry and smaller tube size. The present model is based on mass, momentum, and energy balances in the evaporator, rising tube, condenser, and the falling tube. The homogeneous two-phase flow model is used to evaluate the friction pressure drop of the two-phase flow imposed by the available gravitational head through the loop. The saturation temperature dictates both the chip temperature and the condenser heat rejection capacity. Thermodynamic constraints are applied to model the saturation temperature, which also depends upon the local heat transfer coefficient and the two-phase flow patterns inside the condenser. The boiling characteristics of the enhanced structure are used to predict the chip temperature. The model is compared with experimental data for dielectric working fluid PF-5060 and is in general agreement with the observed trends. The degradation of condensation heat transfer coefficient due to diminished vapor convective effects, and the presence of subcooled liquid in the condenser are expected to cause higher thermal resistance at low heat fluxes. The local condensation heat transfer coefficient is a major area of uncertainty.
Thermal Conductivity of Si/SiGe Superlattices
Authors: Huxtable Scott T. , Abramson Alexis R. , Majumdar Arun , Tien Chang-Lin , LaBounty Chris , Fan Xiaofeng , Zeng Gehong , Bowers John E. , Shakouri Ali , Croke Edward T. 
Published: November 2021

Abstract
The cross-plane and in-plane thermal conductivity of four Si/Si0.7Ge0.3 superlattice structures with periods from 45 Å to 300 Å are experimentally investigated using the 3-ω measurement technique. The experiment is conducted over a temperature range from 70 to 340 K. Results indicate that the cross-plane thermal conductivity decreases with decreasing period thickness (i.e. increasing number of interfaces per unit length). The superlattice with the shortest period exhibits a cross-plane thermal conductivity similar to that of a SiGe alloy. The in-plane thermal conductivity follows a similar decreasing trend with period thickness for the three larger period superlattices, but jumps to higher values for the shortest period superlattice. Additionally, the in-plane conductivity can be 3–4 times higher than the cross-plane value.
Real Time Sub-Micron Thermal Imaging Using Thermoreflectance
Authors: Christofferson James , Vashaee Daryoosh , Shakouri Ali , Melese Philip 
Published: November 2021

Abstract
Thermal measurements on a sub-micron scale are non-trivial, but are important for the characterization of modern semiconductor and opto-electronic devices. In this paper we will discuss the application of the thermoreflectance method for real time sub-micron thermal imaging. By using light in the visible spectrum, the diffraction limit, and thus spatial resolution is improved over a traditional infrared camera based on blackbody emission. With active excitation of the sample and frequency domain filtering, thermal images with 100mK temperature resolution are obtained. Experiments performed on semiconductor micro-coolers and micro-heaters are presented.
Scanning Thermal Microscopy Study of Dissipation in Current-Carrying Carbon Nanotubes
Authors: Shi L. , Kim P. , Plyasunov S. , Bachtold A. , McEuen P. L. , Majumdar A. 
Published: November 2021

Abstract
The temperature distribution of current-carrying carbon nanotubes (CNs) have been measured by scanning thermal microscopy. The thermal imaging results support that multiwall (MW) CNs and semiconducting single wall (SW) CNs are diffusive and dissipative, while metallic SWCNs change from non dissipative at low electric fields to dissipative at high fields due to optical phonon emission. The temperature rise in a 4.5 μm long MWCN was of order 40 K for a power input of 22 μW and increased linearly with power input. There existed a large temperature drop at the tube-substrate interface due to a weak contact thermal conductance about 0.1 W/m-K. For the MWCN, comparable amount of Joule heat was lost from the tube bulk to the substrate and from the tube to the metal contacts.
Visualization of Supercritical Carbondioxide Pseudo-Boiling Inside a Rectangular Channel
Authors: Sakurai K. , Ko H. S. , Okamoto K. , Madarame H. 
Published: November 2021

Abstract
The characteristics of the supercritical fluids should be precisely investigated for the next generation nuclear power reactor, i.e., Super-critical water Cooled Reactor (SCR). There are few experiments for visual observation especially in forced convection, because of the difficulty of the experiment.
A Model for the Structural Mechanisms in the Regulation of Microvessel Permeability by cAMP
Authors: Fu Bingmei M. , Chen Bin 
Published: November 2021

Abstract
To investigate the microstructural mechanisms of decreasing microvascular permeability induced by the enhancement of intraendothelial adenosine 3’,5’-cyclic monophosphate (cAMP) levels, we extended the previous analytical model developed by Fu et al. (J. Biomech. Eng., 1994) for the interendothelial cleft to include multiple junction strands in the cleft and an interface between the surface glycocalyx layer and the cleft entrance. Based on the electron microscopic observation by Adamson et al. (Am. J. Physiol., 1998), that elevation of intracellular cAMP levels would increase number of tight junction strands, numerical method was applied to test the case in which there are two junction strands in the cleft and there are large discontinuous breaks and a small continuous slit in each strand. Results from this two-junction-strand and two-pore model can successfully account for the experimental data for the decreased permeability to water (Adamson et al. Am. J. Physiol., 1998), small and intermediate-sized solutes (Fu et al., Am. J. Physiol., 1998) by cAMP.
Flow Dynamics During Machine Perfusion Preservation of Livers
Authors: Purohit Saurin P. , Nelson Joshua , Zhang Jian , Clemens Mark G. , Lee Charles Y. 
Published: November 2021

Abstract
Hypothermic machine perfusion preservation (MPP) has the potential to relieve the current donor shortage problem by providing superior preserved tissue and viable non-heart-beating donor tissue. For the liver, MPP has not improved preservation. Currently, the major cause of damage associated with MPP of livers is unknown. An intravital microscopy study was conducted to investigate the state of sinusoidal perfusion during 24-hour MPP. Fluorescein isothiocynate (FITC)-labeled albumin was utilized to mark the microvascular space while FITC-labeled red blood cells were used to determine the fluid velocity. The results showed that there was an increase in vascular resistance (&gt; 275%) when the liver was perfused with a UW solution for 24 hours at 5°C and with a flow rate of 5 ml/min. This vascular resistance further increased (&gt; 425%) during rewarming (for 1 hour, at 37°C and 15 ml/min). The mean flow velocities increased during initial MPP from 236 ±16 μm/s (mean ± standard error) to 434 ± 20 μm/s and the mean shear stress values increased from 5.3 ± 0.8 dynes/cm2 to 6.5 ± 0.8 dynes/cm2, after 24 hours of MPP the mean flow velocity values and shear stress values decreased (223 ± 13 μm/s and 3.3 ± 0.8 dynes/cm2) respectively. The reason for this was detected by the FITC-labeled albumin, in the tissue. It was evident that these areas (after 24 hours of MPP) also displayed increased blockage. It also appeared from the micrographs and the histology study that the blockage occurred as a result of endothelial cells rounding after 24 hours of MPP. The cells remained rounded even after rewarming the tissue. This could be a mechanism of damage to the liver during 24-hour of MPP.
In Vitro Assessment of the Efficacy of Thermal Therapy in Human Benign Prostatic Hyperplasia Tissue
Authors: Bhowmick Sankha , Bhowmick Pragati , Coad James E. , Bischof John C. 
Published: November 2021

Abstract
Correlation between thermal history and tissue destruction is of considerable importance for successful management of BPH using minimally invasive thermal therapies such as radiofrequency or microwave probes. In order to accomplish this goal, the present in vitro study assesses the cellular viability of BPH tissue subjected to different temperature-times in an experimental matrix. Hyperplastic prostatic tissue was obtained from 8 patients after the surgical removal of the glands for other reasons (typically cancer). A piece of tissue was taken from the lateral lobe of the gland and was then sectioned into multiple thin strips (1mm thick), placed on a coverslip and heated on a thermally controlled copper block to various temperatures (45°C-70°C) for various times (1 minute–60 minutes). After heat treatment, the tissue slices were cultured for 72 hours and viability data was obtained using two independent assays: histology and dye uptake. Results indicate that the hyperplastic prostate tissue showed a progressive histologic increase in irreversible stromal tissue injury with increasing temperature-time severity. A small amount (∼5% or less) of stromal apoptosis was found in the control and mildly treated tissue. Dye uptake studies for stromal viability paralleled the histologic findings for the temperature-time combinations explored in the present study. In vitro thermal injury thresholds for 90% destruction of human BPH tissue were identified at 45°C-60min, 55°C-20min, 60°C-5min and 70°C-2 min. The Arrhenius model of injury was fit to the viability data after controlled heating to obtain parameters that will allow the prediction of injury under variable heating conditions. Arrhenius analysis of both assays showed a break point at 60°C based on 90% normalized survival. The activation energy (E) values for temperatures below and above the break point were 199.05 and 66.04 kJ/mole for the dye uptake study and 162.6 and 62.99 kJ/mole for histology. The corresponding frequency factor (A) values below and above the break point were 1.81 × 1030 and 1.82 × 109 s−1 for dye uptake study and 2.84 × 1024 and 6.64 × 108 s−1 for histology. This study is the first to report Arrhenius parameters for human BPH tissue for supraphysiological thermal therapy and will be useful for prediction of tissue destruction during thermal therapy of BPH in the clinic.