bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two-Phase Refrigerant Mixture (R-407C) Flow in Smooth Meso-Scale Heat Exchangers
Authors: Shariff Yasir M. , Ravigururajan T. S. 
Published: November 2021

Abstract
The paper presents results from an experimental study on refrigerant mixture flow (R-407C) in which the heat transfer coefficient was measured across a range of heat and mass fluxes. Flow characteristics in smooth horizontal mesochannels were measured for two different conditions, 1) subcooled and 2) saturated boiling with diameters of 1.59, 2.78, and 3.97 mm and a length of 50.8 mm in refrigerant mixture (R-407C). Experiments were performed at heat fluxes of 2 and 11 kW/m2 for the subcooled boiling and 15 and 29 kW/m2 for the saturated boiling. The mass flux was varied from 0.45 to 1.55 kg/min and the refrigerant was subcooled to 8°C. The saturated boiling experiments were conducted for ΔTsat = 0 to 27°C. The heat transfer coefficients were found to be dependent on channel size, heat flux, and mass flux variations. For smaller channel diameters, the heat transfer rate significantly increased as compared to larger channel diameters. The results showed an increase of 100% in heat transfer coefficient when compared to traditional and micro-channel boiling characteristics.
Numerical Simulation of RF Heating for a SIC Vapor Growth System
Authors: Ma R.-H. , Zhang H. , Prasad V. , Ha S. , Skowronski M. 
Published: November 2021

Abstract
A numerical model has been developed to calculate the magnetic potential and temperature distribution in a RF heating system used for a SiC vapor growth system. The magnetic vector potential is calculated by solving the Maxwell equations. The heating power generated in the graphite susceptor is obtained using the Joules law. The temperature profile in a growth chamber is then calculated by solving the energy transport equation with induction heat as a source term. Two sets of grid system have been used to speed up the calculation. The frequency of RF heating and coil current are found to have significant impact on heat generation and its distribution in the graphite susceptor. The maximum temperature in the crucible has a linear relationship with the input power; however, the power input does not influence significantly the temperature gradient. To optimize the heating system for a SiC vapor growth system, the current, frequency, and geometry need to be carefully designed.
Numerical Study of EHD-Enhanced Forced Convection Using Two-Way Coupling
Authors: Huang M. , Lai F. C. 
Published: November 2021

Abstract
In this paper, numerical results are presented for heat transfer enhancement using electric field in forced convection in a horizontal channel. The electric field is generated by charging a wire electrode located at the center of the channel with direct current at a high voltage. The main objective of the present study is to verify the assumption that is commonly used in the numerical study of this kind of problems, which assumes the electric field can modify the flow field but not vice versa (i.e., the so-called one-way coupling). To this end, numerical solutions have been obtained for a wide range of governing parameters (Vo = 10, 12.5, 15 and 17.5 kV as well as ui = 0.0759 to 1.2144 m/s) using both one-way and two-way couplings. Using the two-way coupling approach, the possible modification of the electric field by the primary flow, which was previously neglected, is accounted for. The results obtained using these two approaches, in terms of the flow, temperature, and electric fields as well as the heat transfer enhancement, are thoroughly examined. In addition, their influence over the flow stability is investigated. Finally, the conclusion about the validity of the one-way coupling is reached at the end of the study.
Magnetic Control of Transport Phenomena in CZ Crystal Growth Processes
Authors: Gunzburger M. , Ozugurlu E. , Turner J. , Zhang H. 
Published: November 2021

Abstract
Magnetic fields have been widely used in industry to enhance the performance of crystal growth processes. However, no attempts have been made at applying optimization strategies to effect optimal enhancements. Here, a mathematical formulation and computational techniques are presented to describe optimal control and design strategies for the suppression of turbulent motions in the melt and the minimization of temperature gradients in the crystal in Czochralski crystal growth processes. It is shown that an axial magnetic field can effectively suppress convection in Czochralski growth of silicon. Other control parameters such as crystal and crucible rotation rates are found to be less effective.
Mathematical Modeling of Transient Flow and Heat Transfer in Gas Stirred Molten Steel
Authors: Xia J. L. , Ahokainen T. 
Published: November 2021

Abstract
Transient two phase flow and heat transfer in a gas-stirred steel ladle are numerically investigated. An Eulerian two fluid approach is used. The drag, lift and turbulent dispersion forces are taken into account for the interface interactions. Different interface heat transfer correlations such as Ranz-Marshall and Hughmark relations are used to examine the influence of heat transfer between gas-liquid interface on the flow. The flow pattern, the histories of both gas and molten steel temperatures, and the thermal stratification history are presented. Results show that gas injection can homogenize thermal field and result in a thermal stratification of about 2 °C only (not complete homogenization). The different heat transfer correlations examined for the bubble-liquid interface have negligible impact on the flow and thermal fields. Predictions are compared with experimental data measured in an industrial ladle and a reasonable agreement is achieved.
Analysis of the Effect of Heating Control Conditions on Temperature Distribution in a Wafer During Rapid Thermal Processing With Lamp Heaters
Authors: Hirasawa Shigeki , Suzuki Tadashi , Maruyama Shigenao , Takeuchi Yuhei 
Published: November 2021

Abstract
To unify temperature distribution in a wafer during rapid thermal processing, we calculated the effect of the heating control conditions on temperature distributions in the wafer during heat-up and at steady state by using a program for analyzing three-dimensional radiative heat transfer. We calculated optimum monitoring positions on the wafer in order to minimize the temperature distribution in the wafer. The effects of rotating the wafer, the spacing between the wafer and the shielding ring, the number of monitoring positions, and the initial non-uniform temperature distribution were also calculated. The minimum steady temperature distribution in the wafer at the optimum condition was calculated as ±0.1 K during 100 K/s heat-up and ±0.02 K at 1273 K steady state. We also developed a rapid parallel-computation technique to find the optimum heating control conditions for the whole heating process.
The Effect of Packing Microstructure on the Effective Conductivity of Random Sphere Packing for Sintering Applications
Authors: Lee S. H.-K. , Siu W. W. M. , Ip S. C.-H. 
Published: November 2021

Abstract
Sintering is a thermally activated solid diffusion process. Study of the heat transfer process is one of the key elements for the improvement of sintering technology. Within sphere packings, the three-dimensional interconnected network of spheres and the interconnected pore structures are very complex. In order to bypass this complexity, typically, the porous medium approach has been used for applications allow relative coarse resolution. However, for sintering studies, the traditional effective conductivity determination may not be directly applicable. Firstly, the porosity variation may be very rigorous due to the non-uniform densification process with a stiff temperature gradient. Furthermore, a fine control volume is required for the fine temperature resolution for studying the effect on unbalance densification rate within packings. Therefore, it is necessary to investigate the dependence of the effective conductivity of the small packing on the detailed packing parameters, such as coordination number and the contact radius ratio. Indeed, this study was one of the first attempts to investigate such effect. A numerical study was performed. The results showed that porosity is indeed not the unique parameter for describing the packing structure while the mean coordination number and the mean contact radius ratio are more appropriate for small population size of spheres. With the developed correlation, the effective conductivity can be directly determined for any packing with the known mean coordination number and the known contact radius ratio without requiring any empirical determination.
Nanolithography With a NSOM Tip: Part I — Numerical Simulations
Authors: Fang Nicholas , Zhang Xiang , Xi Min 
Published: November 2021

Abstract
Due to its ability of recording images of surfaces with subwavelength resolution, near-field scanning optical lithography (NSOL) provides a prospective solution for nanolithography. A variety of different photolithography processes at the nanoscale have been realized. However, the development of polymerization at optical near field is yet an unexplored area to researchers. In this paper, we report a series of computerized simulations to investigate some basic phenomena in NSOL.
In this work, we introduce a cylindrical model to represent the metal-coated NSOM tip illuminated by a Gaussian beam. Using numerical method to solve the Maxwell equations to determine light intensity distribution, we applied the result of intensity profile for the first time to study the induced photo-polymerization from reaction kinetic equations of continuum media. We then studied the dependence of curing height and curing radius upon exposure time, with the optimized aperture size and tip sample distance. It has been demonstrated in this work the feasibility of nanolithography with NSOM tip, which would provide a new pathway to nanofabrication.
Nanolithography With a NSOM Tip: Part II — Experiments
Authors: Fang Nicholas , Sun Cheng , Wan Zhiliang , Zhang Xiang 
Published: November 2021

Abstract
We present in this paper a nanolithographic method by introducing a local photo-polymerization in the proximity of tapered optical fiber tip immersed in photocurable resin. The metallic apertured tip, when approached to a solid substrate at a few nanometers distance, delivers UV light to the vicinity of the tip apex and forms a subwavelength light source. The confined light source permits the polymerization to occur locally at the tip extremity, thus allowing generation of micronic/nanometric polymer features. The nanometric positioning control, realized by a commercial AFM operating in tapping mode, ensures the automation of nanolithographic process. The preliminary results presented here validate the concept of near field scanning optical lithography.
Flow Monitoring in Liquid Composite Moulding Based on Linear Direct Current Sensing Technique
Authors: Luthy Thierry , Ermanni Paolo 
Published: November 2021

Abstract
On-line monitoring of the Liquid Composite Moulding (LCM) process is a key element to improve part quality and to reduce manufacturing cost. In this context, direct current (DC) resistance measurement is a promising sensing technique allowing to track both flow front position and degree of curing of the resin during injection. An original measurement technique called Linear Direct Current (LDC) based on the same physical principle as DC was developed to record the flow front position continuously and not only at discrete nodes location. Preliminary measurements in a 1D-flow channel have shown the large influence of the hardware configuration on the accuracy of the LDC system. Further flow experiments were conducted with the support of an embedded print plate in the flow channel as LDC sensor. These 2D measurements have demonstrated the relative good accuracy and stability of the LDC system. Evaluation criteria include qualitative comparison between visual- and LDC-monitoring system with regard to position and shape of the flow front. A software was developed in-house to display the 2D flow front position based on the information delivered by the LDC-system. This study has shown the potential of this original technique to monitor LCM-injection processes. Next steps will include the application of the LDC-technology in a real industrial environment to support the fabrication of complex shaped 3D-structures.
Effect of Time-Dependent Boundary Conditions on Epidermal Tissue Damage During Port Wine Stain Laser Surgery
Authors: Aguilar Guillermo , Valdes Sergio H. Diaz , Nelson J. Stuart , Lavernia Enrique J. 
Published: November 2021

Abstract
Port wine stain (PWS) birthmarks are a congenital and progressive vascular malformation of the dermis, involving capillaries, which occurs in approximately 0.7% of children. The objective of laser surgery for this and similar conditions is to cause selective thermal damage, thrombosis, and, eventually, permanent photocoagulation in the PWS vessels. To achieve this, the radiated laser light is set at a specific wavelength, which is highly absorbed by the blood vessels’ hemoglobin (the major chromophore in blood). Unfortunately, the PWS vessels do not absorb all energy radiated — a significant amount is also absorbed by hemoglobin in the ectatic capillaries of the upper dermis. This unwanted absorption causes two problems: firstly, insufficient heat generation within the targeted vessels leads to poor clinical results, and, secondly, there is an increased risk of damage to the overlying epidermis.
In current PWS laser therapy, cryogen spray cooling (CSC) is used effectively to cool and protect selectively the epidermis (tens of micrometers thick) prior to the laser pulse, while minimally cooling the blood vessels. The thermal response of the system is characterized by time and/or temperature dependent boundary conditions. However, in many recent studies, the boundary conditions induced by CSC are regarded as constant. In the present work we study the effects of time-dependent boundary conditions on the overall epidermal thermal damage after PWS laser therapy. We use computer models to simulate the laser light distribution, heat diffusion, and tissue damage, and introduce experimentally determined time-dependent boundary conditions measured for custom-made and commercial atomizing nozzles. We show that time-dependent boundary conditions have a significant effect in the optimal laser dose required to induce photocoagulation of PWS blood vessels while preserving the epidermis.
Mechanical Properties of Novel Nanocrystalline Materials
Authors: Narayan J. , Wang H. , Kvit A. 
Published: November 2021

Abstract
We have synthesized nanocrystalline thin films of Cu, Zn, TiN, and WC having uniform grain size in the range of 5 to 100 nm. This was accomplished by introducing a couple of manolayers of materials with high surface and have a weak interaction with the substrate. The hardness measurements of these well-characterized specimens with controlled microstructures show that hardness initially increases with decreasing grain size following the well-known Hall-Petch relationship (H∝d−½). However, there is a critical grain size below which the hardness decreases with decreasing grain size. The experimental evidence for this softening of nanocrystalline materials at very small grain sizes (referred as reverse Hall-Petch effect) is presented for the first time. Most of the plastic deformation in our model is envisioned to be due to a large number of small “sliding events” associated with grain boundary shear or grain boundary sliding. This grain-size dependence of hardness can be used to create functionally gradient materials for improved adhesion and wear among other improved properties.
Automatic Repetitive Remapping Applied to the Solution of Indirect Extrusion
Authors: Verderber Rudy R. 
Published: November 2021

Abstract
This paper describes automatic repetitive remapping applied to the solution of indirect extrusion. The application for indirect extrusion is microforging. The remapping algorithm and automatic remapping are critical in the Lagrangian solution of indirect extrusion. The FEA prediction agrees with a closed form solution of the die extrusion force.
Influence of Fasting Glucose Level on Gastric Cancer Incidence in a Prospective Cohort Study
Authors: Tran Tao Thi , Lee Jeonghee , Gunathilake Madhawa , Cho Hyunsoon , Kim Jeongseon 
Published: November 2021

Abstract

Background:
High fasting glucose has been indicated in relation to a higher risk of gastric cancer, but the majority of studies have focused on diabetes (fasting glucose ≥126 mg/dL). Here, we investigated whether fasting glucose levels, including prediabetic and diabetic levels, influence gastric cancer incidence.

Methods:
A prospective study was conducted with 41,837 participants aged 16 and older who underwent health examinations at the National Cancer Center in South Korea from August 2002 to December 2014. Participants were followed up until December 2017 to identify incident gastric cancer cases. A fasting glucose test was performed based on venous blood samples taken from participants after 8 hours of fasting. We used the Cox proportional hazards regression model to explore the association of fasting glucose levels with gastric cancer incidence.

Results:
We identified 263 incident gastric cancer cases during the follow-up period. A significant association of high fasting glucose with gastric cancer incidence was found for postmenopausal women [hazard ratio (HR) = 1.88; 95% confidence interval (CI) = 1.11–3.20]. There was also a significant association between high fasting glucose and gastric cancer incidence among all participants who were nonsmokers (HR = 1.89; 95% CI = 1.21–2.95), had a BMI &lt; 25 kg/m2 (HR = 1.45; 95% CI = 1.00–2.12), and did not have a first-degree family history of gastric cancer (HR = 1.45; 95% CI = 1.06–1.99).

Conclusions:
Our findings support that high fasting glucose is a risk factor for gastric cancer development in postmenopausal women.

Impact:
Our results provide evidence for future planning and management regarding cancer prevention.
Leveraging Genetic Data to Elucidate the Relationship Between COVID‐19 and Ischemic Stroke
Authors: Zuber Verena , Cameron Alan , Myserlis Evangelos P. , Bottolo Leonardo , Fernandez‐Cadenas Israel , Burgess Stephen , Anderson Christopher D. , Dawson Jesse , Gill Dipender 
Published: November 2021

Background
The relationship between COVID‐19 and ischemic stroke is poorly understood due to potential unmeasured confounding and reverse causation. We aimed to leverage genetic data to triangulate reported associations.

Methods and Results

Analyses primarily focused on critical COVID‐19, defined as hospitalization with COVID‐19 requiring respiratory support or resulting in death. Cross‐trait linkage disequilibrium score regression was used to estimate genetic correlations of critical COVID‐19 with ischemic stroke, other related cardiovascular outcomes, and risk factors common to both COVID‐19 and cardiovascular disease (body mass index, smoking and chronic inflammation, estimated using C‐reactive protein). Mendelian randomization analysis was performed to investigate whether liability to critical COVID‐19 was associated with increased risk of any cardiovascular outcome for which genetic correlation was identified. There was evidence of genetic correlation between critical COVID‐19 and ischemic stroke (r
g
=0.29, false discovery rate [FDR]=0.012), body mass index (r
g
=0.21, FDR=0.00002), and C‐reactive protein (r
g
=0.20, FDR=0.00035), but no other trait investigated. In Mendelian randomization, liability to critical COVID‐19 was associated with increased risk of ischemic stroke (odds ratio [OR] per logOR increase in genetically predicted critical COVID‐19 liability 1.03, 95% CI 1.00–1.06,
P
‐value=0.03). Similar estimates were obtained for ischemic stroke subtypes. Consistent estimates were also obtained when performing statistical sensitivity analyses more robust to the inclusion of pleiotropic variants, including multivariable Mendelian randomization analyses adjusting for potential genetic confounding through body mass index, smoking, and chronic inflammation. There was no evidence to suggest that genetic liability to ischemic stroke increased the risk of critical COVID‐19.

Conclusions
These data support that liability to critical COVID‐19 is associated with an increased risk of ischemic stroke. The host response predisposing to severe COVID‐19 is likely to increase the risk of ischemic stroke, independent of other potentially mitigating risk factors.
Photo Essay: Bringing Acupuncture to the People
Authors: Meng Eana 
Published: November 2021

Abstract
This photo essay examines key events in the career of physician-activist Tolbert Small, a doctor for the Black Panther Party and one of the first American doctors to practice acupuncture. It features the historic 1972 Black Panther Party delegation to China where Small first learned about acupuncture, as well as the Harriet Tubman Medical Office where he incorporated acupuncture into his practice.
Reflections on (Re)making History
Authors: Meng Eana 
Published: November 2021

Abstract
Who and what makes history? This essay describes how physician-activist Tolbert Small (b. 1942) has been collecting, preserving, and recording his own history, as well as of those around him. Small has been practicing medicine in California’s San Francisco Bay Area since 1968, serving a diversity of patients: from thousands of community members to revolutionaries such as Angela Davis and George Jackson. A physician for the Black Panther Party from 1970 to 1974, Small joined the party’s 1972 delegation to China, where he witnessed acupuncture. He then integrated the practice into his medical toolkit upon returning home. Small’s personal archives document an important chapter of American social and medical history. His stories, along with those of the revolutionaries who introduced acupuncture into New York City’s Lincoln Detox Center during the 1970s, ask us to revisit conventional historical narratives as well as the way in which acupuncture history is made.
Community Medicine as Racial Justice
Authors: Wu Yi-Li , Dandridge Tenisha 
Published: November 2021

Abstract
Tenisha Dandridge is a cofounder and the current president of the Black Acupuncturist Association (US). She advocates using Chinese medicine and acupuncture to address the racial health disparities afflicting African Americans. In June 2020 an editor of Asian Medicine interviewed her about her career and medical activism. The main themes of the interview include: how racial bias results in disproportionately high rates of morbidity and mortality among African Americans; how the theories and therapies of Chinese medicine are well suited for addressing the psychophysiological harms caused by racial discrimination; why it is important to increase Black representation in the acupuncture profession; and how community-based modes of healing can expand African Americans’ interest in, access to, and utilization of acupuncture and ear seed acupressure.