bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heat Transfer Characteristics of Mixed Convective Magnetohydrodynamic Counter-current Two-Phase Flow in Rotating Inclined Microporous Channel With Slip Velocity and Asymmetric Thermal Boundary Conditions Using LTNE Model
Authors: Rani Hari Ponnamma , Leela V. , Nagabhushana Pulla , Reddy R. Gangadhara 
Published: August 2021

Abstract
The heat transfer characteristics of a mixed convective two-phase flow in an inclined rotating microporous channel kept in a transverse magnetic field are investigated numerically. The counterflow arrangement is assumed within the channel. Slip velocity and asymmetric thermal boundary conditions are assumed. The governing energy equation involves the local thermal non-equilibrium (LTNE) between the two phases. The LTNE implications of the control parameters on the flow field variables and the average Nusselt number, Nu, are highlighted, and pertinent observations are documented. When confined to a few specific cases, the current results are consistent with previous research work. The effect of inclination angle on fluid velocity is determined by the wall temperature difference ratio. According to the findings, for certain values of the wall temperature differential ratio, the velocity increases with the angle; however, it takes on a dual character for other values. The Nusselt number (Nu) is expected to increase with the Biot number, Hartmann number, and rotation parameter, while Nu decreases as the Knudsen number increases. The results also show that as the wall temperature ratio increases, the Nu converges to a common minimum value. This research combines computational fluid dynamics (CFD) simulation and artificial neural network (ANN) analysis. The database was generated from the validated CFD model covering a range of control parameters arising in the system. The multilayer perceptron (MLP) networks were trained using this CFD data set to predict Nu. It is observed that the predicted data given by the ANN model is in good accordance with the estimated values of Nu. The average relative error in Nu's prediction is found to be ±2%.
A Novel Approach for Bounding the Stress Experienced by the Core of Utility-Scale Printed Circuit Heat Exchangers Under Thermohydraulic Loads
Authors: Katz Alon , Messner Mark C. , Ranjan Devesh 
Published: August 2021

Abstract
Printed circuit heat exchangers (PCHEs) have rapidly gained popularity since being introduced nearly three decades ago, and they are currently widely deployed in the petrochemical and aviation industry. Their compactness, thermohydraulic efficiency, inherent suitability for high temperature/pressure fluids containment, and demonstrated durability are some of the reasons the nuclear industry is seeking to adopt this technology as well. However, the relatively strict nuclear-related regulatory design code, especially when classified as critical to the safety of the reactors, is posing challenges to adopting the technology. From stress analysis point of view, one undesirable feature of PCHEs is their geometrical complexity, which is implied by their multilength-scale features. As a result, a full-scale model of a utility-scale exchanger cannot simply be solved on a computer because meshing such components results in a vast number of degrees-of-freedom. This work seeks to address the challenge of stress analyses to PCHEs by presenting a method to simplify the geometry of PCHE designs. The models proposed by this work can be practically analyzed on a standard computer and provide a path for implementing ASME design rules. The analyses presented herein are divided into five separate investigations. Each is carried out to incrementally simplify the analyzed model by addressing features such as the shapes of the flow passages, the complex distribution of stress in large components, the three-dimensionality of the stress and strain, the thermal stresses caused by thermohydraulic operation observed experimentally and more.
Neuromodulation Applications for Chronic Pain
Authors: Persaud-Sharma Dharam , William Mallet John , Panjeton Geoffrey Danial , Ogbemudia Blessing , Ahmad Affan , Coombes Stephen , Antony Ajay 
Published: August 2021

Abstract
Chronic back pain is highly prevalent worldwide, affecting over 10% of the global population. It is a complex medical problem that affects individuals, families, and communities and has a costly economic impact through an impaired workforce. Pain mechanisms are complicated and include biological, psychological, and social components that can combine to drive unique pain experiences. Beyond conservative management with multimodal pharmacotherapy and more invasive surgical intervention for an identifiable anatomical abnormality, there are limited therapies for the resolution of chronic pain. However, exciting technological developments in spinal cord stimulation have renewed interest in neuromodulation for patients with refractory pain after both conservative and surgical management. Here, we review the efficacy of spinal cord stimulator technologies and other related technologies, including dorsal root ganglion stimulators and peripheral nerve stimulators, as well as highlight future areas of research.
Robotic Tensegrity Structure With a Mechanism Mimicking Human Shoulder Motion
Authors: Li Lengxue , Kim Sunhong , Park Junho , Choi Youngjin , Lu Qiang , Peng Dongliang 
Published: August 2021

AbstractThis paper proposes a three degrees-of-freedom tensegrity structure with a mechanism inspired by the ligamentous structure of the shoulder. The proposed mechanism simulates the wide motion ranges of the human shoulder joint and is composed of 3 rigid bodies and 16 steel wires with 3 mutually perpendicular rotating axes. Since it belongs to the class 1 tensegrity structure that the rigid bodies do not make any contact with each other, the joint has a certain amount of flexibility, which not only can help protect its mechanism from external impacts but also can prevent human injury that might happen when the mechanism and humans interact each other. Moreover, the proposed mechanism can be manufactured using fewer materials than a fully rigid mechanism, and thus, it can be made in a lightweight fashion and reduce the inertial effects as well. Finally, to actuate the robotic shoulder, the cables connected to each motor are able to drive the rotating shafts of the joint mechanism.
Analytical Modeling of Machining Forces and Friction Characteristics in Ultrasonic-Assisted Turning Process
Authors: Airao Jay , Nirala Chandrakant K. 
Published: August 2021

Abstract
Intermittent cutting characteristics of ultrasonic-assisted turning (UAT), compared with conventional turning (CT), has shown a significant enhancement in the machinability of hard-to-cut materials. The enhancement in machinability is associated with machining forces and friction characteristics of the process. The present article covers an analytical approach to predict the output responses such as machining forces and friction characteristics in UAT and CT processes. Specific cutting energy (SCE) for a particular work-piece material was considered to predict the output responses. The predictions were made by considering the conventional machining theories. Experiments for the UAT and the CT of SS 304 were carried out to validate the predicted model. The results from the analytical model showed that the shear angle increases and the tool work-piece contact ratio (TWCR) decrease with an increase in amplitude and frequency of vibration. The results obtained from the analytical model were found to be in close agreement with the experimental ones, with an approximate error of 2–20%.
Impact of Cooling Injection on Shock Wave Over a Flat Tip in High Pressure Turbine
Authors: Ma Haiteng , Zeng Wei , Jiang Hongmei , Hong Jun 
Published: August 2021

AbstractCooling design of highly loaded turbine blade tips is challenged by the scarcity of experimental data and the lack of physical understanding in cooling and overtip leakage (OTL) interaction under transonic conditions. To address these issues, this paper carried out transient thermal measurements through infrared thermography on a transonic flat tip with and without cooling injection. Experimental data of Nusselt number and cooling effectiveness were obtained and compared with computational fluid dynamics (CFD) results for numerical validation. Both experimental data and simulation results show that cooling injection drastically augments tip Nusselt number near pressure side (PS) which is upstream of ejection, and in areas around coolant holes. Moreover, a strikingly low Nusselt number stripe is observed downstream of cooling injection from one of the holes in aft portion of blade. The strip is directed transverse to local OTL streamline flowing from pressure to suction side (SS) and sprawls to adjacent coolant wakes. Further numerical analyses concluded that cooling injection changes tip aerodynamics and overtip shock wave structure fundamentally. Oblique shock waves across the uncooled flat tip are replaced by a confined shock train downstream of cooling injection and between cooling holes, which is constituted by two shocks normal to local OTL flow coming from pressure side. Across the first shock, density and pressure increases abruptly, contributing to thickening of tip boundary layer and the plummet of skin friction on tip surface, which is responsible for the sharp decline of tip Nusselt number and therefore, formation of low heat transfer stripe downstream cooling injection.
Global Optimization of a Transonic Fan Blade Through AI-Enabled Active Subspaces
Authors: Lopez Diego I. , Ghisu Tiziano , Shahpar Shahrokh 
Published: August 2021

AbstractThe increased need to design higher performing aerodynamic shapes has led to design optimization cycles requiring high-fidelity CFD models and high-dimensional parametrization schemes. The computational cost of employing global search algorithms on such scenarios has typically been prohibitive for most academic and industrial environments. In this paper, a novel strategy is presented that leverages the capabilities of artificial neural networks for regressing complex unstructured data, while coupling them with dimensionality reduction algorithms. This approach enables employing global-based optimization methods on high-dimensional applications through a reduced computational cost. This methodology is demonstrated on the efficiency optimization of a modern jet engine fan blade with constrained pressure ratio. The outcome is compared against a state-of-the-art adjoint-based approach. Results indicate that the strategy proposed achieves comparable improvements to its adjoint counterpart with a reduced computational cost and can scale better to multi-objective optimization applications.
Investigating Gas Turbine Internal Cooling Using Supercritical CO2 at Higher Reynolds Numbers for Direct Fired Cycle Applications
Authors: Searle Matthew , Roy Arnab , Black James , Straub Douglas , Ramesh Sridharan 
Published: August 2021

Abstract
Experimental and numerical investigations of three variants of internal cooling configurations—dimples only, ribs only, and ribs with dimples have been explored at process conditions (96 °C and 207 bar) with sCO2 as the coolant. The designs were chosen based on advanced internal cooling features typically used for air-breathing gas turbines. The experimental study described utilizes additively manufactured square channels with the cooling features over a range of Reynolds number from 80,000 to 250,000. Nusselt number is experimentally calculated utilizing the Wilson Plot method and three heat transfer characteristics—augmentation in Nusselt number, friction factor, and overall thermal performance factor (TPF) are reported. To explore the effect of surface roughness introduced due to additive manufacturing, two baseline flow cases are considered—a conventional smooth tube and an additively manufactured square tube. A companion computational fluid dynamics (CFD) simulation is also performed for the corresponding cooling configurations reported in the experiments using the Reynolds-averaged Navier–Stokes (RANS) based turbulence model. Both experimental and computational results show increasing Nusselt number augmentation as higher Reynolds numbers are approached, whereas prior work on internal cooling of air-breathing gas turbines predict a decay in the heat transfer enhancement as Reynolds number increases. Comparing cooling features, it is observed that the “ribs only” and “ribs with dimples” configurations exhibit higher Nusselt number augmentation at all Reynolds numbers compared with the “dimples only” and the “no features” configurations. However, the frictional losses are almost an order of magnitude higher in the presence of ribs.
Rhabdophane Th-Pb ages indicate reactivation of Mesoarchean structures in west Pilbara Craton during breakup of Greater India and Australia-Antarctica
Authors: Rasmussen Birger , Zi Jian-Wei , Muhling Janet R. 
Published: August 2021

Abstract
Uranium-Th-Pb dating of phosphate minerals in very low-grade metasedimentary rocks from the Archean Pilbara Craton, Western Australia, has revealed a long history of deformation and fluid flow during the Paleoproterozoic. However, this technique has not detected evidence for fluid flow along craton margins during Phanerozoic rifting and breakup. We report the use of in situ Th-Pb geochronology of rhabdophane, a hydrous light rare earth element phosphate, to date fluid flow in shale from the 2.76 Ga Mount Roe Basalt from drill hole number 6 of the Archean Biosphere Drilling Program (ABDP6), northwestern Pilbara Craton. Thorium-Pb dating of rhabdophane in carbonaceous shale yields three main populations with weighted mean 208Pb/232Th ages of 152 ± 6 Ma, 132 ± 4 Ma, and 119 ± 4 Ma, which indicates phosphate growth up to 2.64 b.y. after deposition. The rhabdophane ages are coeval with three major breakup events in eastern Gondwana: separation of Southwest Borneo and Argoland from Australia (ca. 156–152 Ma), breakup of Greater India from Australia (ca. 140–135 Ma), and separation of Greater India/India from Antarctica (ca. 123 Ma). The proximity of drill hole ABDP6 to major Mesoarchean faults and shear zones on the craton margin, which are parallel to rift propagation and basin development, points to episodic reactivation of ancient crustal structures &gt;2.8 b.y. after their formation. Our results also highlight the potential of rhabdophane as a U-Th-Pb geochronometer for dating low-temperature (&lt;200 °C) fluid flow and hydrous alteration. The migration of Mesozoic fluids through Archean shales adds weight to questions about the origin of geochemical signals in ancient altered rocks and how to extract information about the early environment and biosphere.
Late Weichselian ice-sheet flow directions in the Russian northern Barents Sea from high-resolution imagery of submarine glacial landforms
Authors: Dowdeswell Julian A. , Montelli Aleksandr , Akhmanov Grigorii , Solovyeva Marina , Terekhina Yana , Mironyuk Sergey , Tokarev Mikhail 
Published: August 2021

Abstract
The locations and orientations of more than 1000 late Quaternary subglacial and ice-marginal landforms, including streamlined sedimentary bed forms, glacitectonic hill-hole pairs, meltwater channels, and eskers, were mapped from blocks of multibeam data (area of 4861 km2) in the little-known Russian Barents Sea. Between Sentralbanken and Admiralty Bank, at ∼75°N, there is evidence for southward ice flow. Ice-flow indicators between Franz Josef Land and Novaya Zemlya show northeast flow into the head of St. Anna Trough. There is also evidence of southeast flow off the bank to the south of Franz Josef Land, and of flow convergence with northeast-flowing ice in Sedov Trough. Northeast flow of ice between Novaya Zemlya and Franz Josef Land suggests that the latter archipelago was not overrun by ice flowing north from the Barents Sea and, therefore, that a subsidiary ice dome was likely on Franz Josef Land. A major ice divide was also present at ∼76°N –77°N in the Russian Barents Sea.
Two-year longitudinal trajectory patterns of albuminuria and subsequent rates of end-stage kidney disease and all-cause death: a nationwide cohort study of biopsy-proven diabetic kidney disease
Authors: Yamanouchi Masayuki , Furuichi Kengo , Hoshino Junichi , Toyama Tadashi , Shimizu Miho , Yamamura Yuta , Oshima Megumi , Kitajima Shinji , Hara Akinori , Iwata Yasunori , Sakai Norihiko , Oba Yuki , Matsuoka Shusaku , Ikuma Daisuke , Mizuno Hiroki , Suwabe Tatsuya , Sawa Naoki , Yuzawa Yukio , Kitamura Hiroshi , Suzuki Yoshiki , Sato Hiroshi , Uesugi Noriko , Ueda Yoshihiko , Nishi Shinichi , Yokoyama Hitoshi , Nishino Tomoya , Samejima Kenichi , Kohagura Kentaro , Shibagaki Yugo , Makino Hirofumi , Matsuo Seiichi , Ubara Yoshifumi , Wada Takashi 
Published: August 2021

IntroductionData on the association between longitudinal trajectory patterns of albuminuria and subsequent end-stage kidney disease (ESKD) and all-cause mortality in diabetic kidney disease (DKD) are sparse.Research design and methodsDrawing on nationally representative data of 329 patients with biopsy-proven DKD and an estimated glomerular filtration rate above 30 mL/min/1.73 m2at the time of biopsy, we used joint latent class mixed models to identify different 2-year trajectory patterns of urine albumin to creatinine ratio (UACR) and assessed subsequent rates of competing events: ESKD and all-cause death.ResultsA total of three trajectory groups of UACR were identified: ‘high-increasing’ group (n=254; 77.2%), ‘high-decreasing’ group (n=24; 7.3%), and ‘low-stable’ group (n=51; 15.5%). The ‘low-stable’ group had the most favorable risk profile, including the baseline UACR (median (IQR) UACR (mg/g creatinine): ‘low-stable’, 109 (50–138); ‘high-decreasing’, 906 (468–1740); ‘high-increasing’, 1380 (654–2502)), and had the least subsequent risk of ESKD and all-cause death among the groups. Although there were no differences in baseline characteristics between the ‘high-decreasing’ group and the ‘high-increasing’ group, the ‘high-decreasing’ group had better control over blood pressure, blood glucose, and total cholesterol levels during the first 2 years of follow-up, and the incidence rates of subsequent ESKD and all-cause death were lower in the ‘high-decreasing’ group compared with the ‘high-increasing’ group (incidence rate of ESKD (per 1000 person-years): 32.7 vs 77.4, p=0.014; incidence rate of all-cause death (per 1000 person-years): 0.0 vs 25.4, p=0.007).ConclusionsDynamic changes in albuminuria are associated with subsequent ESKD and all-cause mortality in DKD. Reduction in albuminuria by improving risk profile may decrease the risk of ESKD and all-cause death.
Are COVID-19 mitigation measures reducing preterm birth rate in China?
Authors: Bian Zheng , Qu Xiaoxian , Ying Hao , Liu Xiaohua 
Published: August 2021

ObjectivePreterm birth is the leading cause of child morbidity and mortality globally. We aimed to determine the impact of the COVID-19 mitigation measures implemented in China on 23 January 2020 on the incidence of preterm birth in our institution.DesignLogistic regression analysis was used to investigate the association between the national COVID-19 mitigation measures implemented in China and the incidence of preterm birth.SettingShanghai First Maternity and Infant Hospital, Shanghai China.ParticipantsAll singleton deliveries abstracted from electronic medical record between 1 January 2014 to 31 December 2020.Main outcome measuresPreterm birth rate.ResultsData on 164 107 singleton deliveries were available. COVID-19 mitigation measures were consistently associated with significant reductions in preterm birth in the 2-month, 3-month, 4-month, 5-month time windows after implementation (+2 months, OR 0.80, 95% CI 0.69 to 0.94; +3 months, OR 0.83, 95% CI 0.73 to 0.94; +4 months, OR 0.82, 95% CI 0.73 to 0.92; +5 months, OR 0.84, 95% CI 0.76 to 0.93). These reductions in preterm birth were obvious across various degrees of prematurity, but were statistically significant only in moderate-to-late preterm birth (32 complete weeks to 36 weeks and 6 days) subgroup. The preterm birth difference disappeared gradually after various restrictions were removed (7th–12th month of 2020, OR 1.02, 95% CI 0.94 to 1.11). There was no difference in stillbirth rate across the study time window.ConclusionSubstantial decreases in preterm birth rates were observed following implementation of the national COVID-19 mitigation measures in China. Further study is warranted to explore the underlying mechanisms associated with this observation.
Multicenter phase II trial (SWOG S1609, cohort 51) of ipilimumab and nivolumab in metastatic or unresectable angiosarcoma: a substudy of dual anti-CTLA-4 and anti-PD-1 blockade in rare tumors (DART)
Authors: Wagner Michael J , Othus Megan , Patel Sandip P , Ryan Chris , Sangal Ashish , Powers Benjamin , Budd G Thomas , Victor Adrienne I , Hsueh Chung-Tsen , Chugh Rashmi , Nair Suresh , Leu Kirsten M , Agulnik Mark , Sharon Elad , Mayerson Edward , Plets Melissa , Blanke Charles , Streicher Howard , Chae Young Kwang , Kurzrock Razelle 
Published: August 2021

PurposeAngiosarcoma is a rare aggressive endothelial cell cancer with high mortality. Isolated reports suggest immune checkpoint inhibition efficacy in angiosarcoma, but no prospective studies have been published. We report results for angiosarcoma treated with ipilimumab and nivolumab as a cohort of an ongoing rare cancer study.MethodsThis is a prospective, open-label, multicenter phase II clinical trial of ipilimumab (1 mg/kg intravenously every 6 weeks) plus nivolumab (240 mg intravenously every 2 weeks) for metastatic or unresectable angiosarcoma. Primary endpoint was objective response rate (ORR) per RECIST 1.1. Secondary endpoints include progression-free (PFS) and overall survival, and toxicity. A two-stage design was used.ResultsOverall, there were 16 evaluable patients. Median age was 68 years (range, 25–81); median number of prior lines of therapy, 2. Nine patients had cutaneous and seven non-cutaneous primary tumors. ORR was 25% (4/16). Sixty per cent of patients (3/5) with primary cutaneous scalp or face tumors attained a confirmed response. Six-month PFS was 38%. Altogether, 75% of patients experienced an adverse event (AE) (at least possibly related to drug) (25% grade 3–4 AE); 68.8%, an immune-related AE (irAE) (2 (12.5%), grade 3 or 4 irAEs (alanine aminotransferase/aspartate aminotransferase increase and diarrhea)). There were no grade 5 toxicities. One of seven patients in whom tumor mutation burden (TMB) was assessed showed a high TMB (24 mutations/mb); that patient achieved a partial response (PR). Two of three patients with PDL1 immunohistochemistry assessed had high PDL1 expression; one achieved a PR.ConclusionThe combination of ipilimumab and nivolumab demonstrated an ORR of 25% in angiosarcoma, with three of five patients with cutaneous tumors of the scalp or face responding. Ipilimumab and nivolumab warrant further investigation in angiosarcoma.Trial registration numberNCT02834013.