bluuebunny/crossref_metadata_2025_split huggingface dataset:
Processing Multicomponent Blade Tip Timing Experimental Data by Independent Component Analysis
Authors: Rizzetto Elena , Carassale Luigi 
Published: September 2022

Abstract
Blade tip timing (BTT) is a simple, robust, and nonintrusive method for measuring the rotor blade vibrations in turbomachinery. Using this method, the analysis of vibrations characterized by multiple spectral components typical, for example, of flutter is challenging. This chapter proposes a probabilistic method able to separate and identify multiple harmonic components sampled according to a BTT-like schema. The data are divided into batches of fixed length called snapshots, which are interpreted as realization of random vectors. The statistical properties of the subspace spanned by such random vectors is used to identify the number of components present in the signal (i.e., number of active modes), to separate the components and estimate their frequency and amplitude. These results are obtained by applying sequentially the principal component analysis (PCA), the independent component analysis (ICA), and the harmonic matching (HM). The proposed technique is applied to experimental data obtained from a test rig with fixed disk and traveling load. The time-resolved measurements are resampled according to the sampling pattern induced by specified sensor spacing.
Viscoelastic Properties of Bioprinted Alginate Microbeads Compared to Their Bulk Hydrogel Analogs
Authors: Roberge Cassandra L. , Kingsley David M. , Cornely Lexie R. , Spain Connor J. , Fortin Aiyana G. , Corr David T. 
Published: September 2022

Abstract
Hydrogel microbeads are engineered spherical microgels widely used for biomedical applications in cell cultures, tissue engineering, and drug delivery. Their mechanical and physical properties (i.e., modulus, porosity, diffusion) heavily influence their utility by affecting encapsulated cellular behavior, biopayload elution kinetics, and stability for longer term cultures. There is a need to quantify these properties to guide microbead design for effective application. However, there are few techniques with the μN-level resolution required to evaluate these relatively small, compliant constructs. To circumvent mechanically testing individual microbeads, researchers often approximate microbead properties by characterizing larger bulk gel analogs of the same material formulation. This approach provides some insight into the hydrogel properties. However, bulk gels possess key structural and mechanical differences compared to their microbead equivalents, which may limit their accuracy and utility as analogs for estimating microbead properties. Herein, we explore how microbead properties are influenced by hydrogel formulation (i.e., alginate concentration, divalent cation crosslinker, and crosslinker concentration), and whether these trends are accurately reflected in bulk gel analogs. To accomplish this, we utilize laser direct-write bioprinting to create 12 × 12 arrays of alginate microbeads and characterize all 144 microbeads in parallel using a commercially available microcompression system. In this way, the compressive load is distributed across a large number of beads, thus amplifying sample signal. Comparing microbead properties to those of their bulk gel analogs, we found that their trends in modulus, porosity, and diffusion with hydrogel formulation are consistent, yet bulk gels exhibit significant discrepancies in their measured values.
Comparing Instrumentation Selection Techniques for Vibration Testing
Authors: Khan Moheimin , Wilbanks Justin , Smith Chandler , Walsh Timothy , Owens Brian 
Published: September 2022

Abstract
Vibration testing of complex aerospace structures requires substantial pretest planning. Ground and flight testing of structures can be costly to execute in terms of time and money, so it is pertinent that tests are properly set up to capture mode shapes or dynamics of interest. One of the most important planning tasks is the placement of sensors to acquire measurements for control and characterization of the results. In this paper, we will examine two techniques that can leverage available output from finite element modeling to intelligently place accelerometers for a vibration test to capture the structural dynamics throughout a specified frequency range with a data acquisition channel budget. These two techniques are effective independence (EI) and optimal experimental design (OED). Both methods will be applied to an aerospace structure. Effects of the chosen sets on system equivalent reduction and expansion process (SEREP) are detailed alongside simpler comparison metrics, like the auto-modal assurance criterion (auto-MAC). In addition to comparing the resulting instrumentation sets, the application of the two approaches will be compared in terms of the inputs required, the information obtained from their application, and the computation time requirements. Both OED and EI offer an effective method for selecting an instrumentation set for a given vibration test. EI is a straightforward, computationally inexpensive approach that provides effective instrumentation sets. OED provides an effective alternative that is less sensitive to the impact of local modes and leads to a natural ranking of importance for each chosen degree-of-freedom (DOF).
The Characteristics of a Novel After-Burner Used for Metal-Supported Planar SOFC System
Authors: Li Siyuan , Zhang Zhe , Li Guoxiang , Bai Shuzhan 
Published: September 2022

Abstract
A novel after-burner used for the heat-up and normal operating conditions of a metal-supported planar solid oxide fuel cell (SOFC) system, is designed and experimentally studied in this paper. The burner construction and the calculation of maximum burner power are shown in detail. Meanwhile, its static characteristics are researched through the influence of excess air ratio (ER), air velocity, inlet air temperature, and fuel utilization rate (Uf) and its transient characteristics are researched through the processes of burner start-up, burner operating state switch, and stack start-up. The results suggest that the best ER value gets larger with the increased burner power. The air velocity is better controlled within 3 m/s to prevent the influence of a lifted flame. High inlet air temperature can extend the lean combustion range and reduces incomplete combustion products, but large ER mutations should still be avoided. In the case of anode off-gas combusting with cathode off-gas, there are nearly zero emissions. Meanwhile, the flue gas temperature decreases to about 760 °C because of enlarged heat loss, but it is minimally influenced by Uf. Under the static condition, the optimal point with both controlled temperature and lowest emissions can be obtained in a wide range, and the after-burner can well adapt to various operating states of the stack. Under the transient condition, the after-burner has good response performance with much shorter time in burner start-up and burner operating state switch than conventional porous media ones. It can start up the stack in 1715 s.
Effect of Hydraulic Diameter and Surface Roughness on Additively-Manufactured Offset Strip Fin Heat Exchanger Performance
Authors: Baker T. M. , Manahan M. P. , Lynch S. P. , Reutzel E. W. 
Published: September 2022

Abstract
Compact heat exchangers with air-side offset strip fins are commonly used where liquid-to-air heat transfer is required. The fins provide increased surface area for the air-side heat transfer, and the liquid is pumped through channels that are transverse to the air-flow direction. Traditionally-manufactured offset strip fin (OSF) heat exchangers are typically made by stamping sheet metal to produce fins with a sinusoidal or near square-wave fashion. These stamped sheets are then brazed or welded to the liquid channels. A plethora of empirical data and correlations exists to predict the heat transfer and pressure drop on the air-side of traditionally manufactured offset strip fin heat exchangers. Recently, additively-manufactured (AM) offset strip fin heat exchangers have been shown to provide manufacturing benefits, such as the ability to remove complicated liquid manifold welds as well as enhanced fin and oil channel features. Furthermore, they provide a convenient reference point for comparing the heat exchanger performance to that of a traditionally-manufactured equivalent. The present investigation shows empirical data from six additively-manufactured offset strip fin coupons of varying fin spacing and fin height to produce two groups of hydraulic diameters: 2.6 mm and 4.1 mm. The surface roughness of these coupons is notably different than traditionally-manufactured offset strip fins. The heat transfer and pressure drop behavior are compared to the correlations for traditionally-manufactured heat exchangers as well as ones derived specifically for ones that were additively manufactured.
Filling critical gaps in the space-time record of High Lava Plains and co-Columbia River Basalt Group rhyolite volcanism
Authors: Swenton Vanessa M. , Streck Martin J. , Miggins Daniel P. , McIntosh William C. 
Published: September 2022

Miocene rhyolitic volcanism of eastern Oregon, USA, can be divided into two main episodes. Mantle plume upwelling is thought to have generated Columbia River Basalt Group (CRBG) lavas and coeval &gt;16.5−15 Ma silicic volcanism trending north−south from northeast Oregon to northern Nevada. Rhyolite volcanism of the 12−0 Ma High Lava Plains province has been ascribed to either buoyancy-driven westward plume spreading or to slab rollback and mantle convection spanning from southeast Oregon to Newberry Volcano to the west. The apparent ca. 15−12 Ma eruptive hiatus suggests that rhyolites of these provinces were a product of separate processes, yet this gap was based on incomplete data. The lack of data on ∼33 of the total ∼50 rhyolitic eruptive centers in the area where the two provinces overlap (117−119°W, 43−44°N) yields only tenuous relationships between these two provinces.
We acquired 40Ar/39Ar ages for 29 previously unanalyzed rhyolite centers that confirm the existence of a rhyolitic eruptive episode concurrent with CRBG flood basalt volcanism. Rhyolite eruptions gradually initiated at ca. 17.5 Ma, and our new ages indicate that peak intensity of the first eruptive episode occurred between 16.3 Ma and 14.4 Ma. We refine the ca. 15−12 Ma rhyolitic eruptive hiatus to 14.4−12.1 Ma, where strong recommencement of rhyolite eruptions began with Beatys Butte at 12.05 Ma. We find two prominent fluxes in rhyolitic eruptive activity after 12.1 Ma as opposed to one continuous, age-progressive trend, at 12.1−9.6 Ma and 7.7−5.1 Ma, which are separated by an ∼2 m.y. period of decreased rhyolite volcanism. Rhyolite eruptions were scarce after 5.1 Ma, at which point most eruptions were associated with Newberry Volcano. Periodicity of rhyolite volcanism along the High Lava Plains demands more punctuated basalt inputs than what continuous partial melting from west-spreading plume material should generate.
Our new data suggest that regional rhyolite eruptions are a series of episodic events related to the arrival and storage of mafic mantle magmas. Paucity in rhyolite eruptions from 14.4 Ma to 12.1 Ma is related to decreased flux of CRBG flood basalt magmas at ca. 15 Ma. Strong recommencement of rhyolite volcanism at 12.1 Ma is related to continued Northwest Basin and Range extension and a peak rotation rate of Siletzia affecting regional lithosphere weakened by CRBG volcanism. Waning rhyolitic eruptive activity from ca. 9.6 Ma to 7.7 Ma reflects a regional transition in the primary mode of accommodation of extension from Northwest Basin and Range normal faulting to extension and shearing of the Brothers Fault Zone. Rhyolite volcanism between 7.7 Ma and 5.1 Ma was driven by continued regional extension in an area less affected by CRBG magmatism. Post-5.1 Ma rhyolite eruptions occurred within crust not influenced by CRBG magmatism but impacted by both regional extension and the Cascadia subduction zone.
The Cretaceous-Paleogene contact in the Tornillo Group of Big Bend National Park, West Texas, USA
Authors: Lehman Thomas M. , Cobb Jacob , Sylvester Paul , Souders A. Kate 
Published: September 2022

Abstract
The Cretaceous-Paleogene (K-Pg) contact interval is constrained by vertebrate fossil sites at seven sites in the Tornillo Group and lies within an 80–100-m stratigraphic section between the top of the Javelina Formation and the base of the “log jam sandstone” marker bed in the Black Peaks Formation. In western exposures of this interval, the highest occurrence of in situ dinosaur specimens and the lowest occurrence of Paleocene mammal specimens are separated by an unusual conglomerate bed. This thin conglomerate bed coincides with the contact between Cretaceous and Paleogene strata and contains reworked Cretaceous fossils. It is superficially similar to conglomerate beds elsewhere attributed to the effects of tsunamis generated by the Chicxulub impact; however, the maximum depositional age of ca. 63 Ma based on detrital zircons indicates that the conglomerate was deposited about three million years after the K-Pg boundary event. Paleocene mammalian fossils from immediately above the conglomerate bed represent a fauna that can be no older than the middle Torrejonian (To2 interval zone). The contact between Cretaceous and Paleocene strata is therefore disconformal and represents a hiatus of at least three million years. A condensed section occurs at the westernmost exposure of the K-Pg contact, where at least 80 m of strata are absent below the conglomerate bed; these strata are present in exposures farther east. This condensed section likely records an erosional event resulting from uplift and deformation of the nearby Terlingua monocline. Although the 80 m of strata below the conglomerate bed are poorly fossiliferous, several clearly in situ dinosaur specimens indicate that this entire interval is Late Cretaceous in age. There is no compelling evidence for preservation of the K-Pg boundary event horizon at any of the seven sites in the Tornillo Group, and so the hiatus represented at the Cretaceous/Paleocene contact here likely also includes some part of latest Cretaceous time. Mammalian specimens from sites in the “log jam sandstone,” ~40 m above the middle Torrejonian sites, represent an early Tiffanian fauna (Ti1 interval zone). Latest Torrejonian (To3) sites have not been recognized, and therefore a second disconformity likely coincides with the base of the “log jam sandstone” marker horizon in the Black Peaks Formation.
Characteristic Analysis of the Dynamics of Shock Wave Propagation in a Medium with a Nonuniform Density Distribution
Authors: Poroshyna Ya. E. , Lopato A. I. , Utkin P. S. 
Published: September 2022

Abstract
This paper is devoted to the numerical study of shock wave (SW) propagation in a medium with a nonuniform density distribution. The mathematical model is based on the Euler equations, which are solved in the shock-attached frame. This approach makes it possible to carry out an accurate characteristic analysis of the problem. First, the problems of SW propagation in a medium with finite-length segments with linearly increasing and decreasing density are considered. The obtained results are compared with the known analytical solutions. Then the case of a continuous change in the density of the medium in front of the SW according to the sinusoidal law is considered. The resulting flow is described and explained using the results for the case of a linear density gradient.
Utilisation of growth monitoring service by mothers of infants in Mettu town, Southwest Ethiopia
Authors: Tufa Yohanis , Mitiku Abeza , Shemsu Shuayib , Bidira Kebebe 
Published: September 2022

BackgroundGrowth monitoring (GM) is a preventive activity that serves as the core function in an integrated child health and nutrition programme. In most developing nations, including Ethiopia, however, the use of GM service is insufficient. Hence, the purpose of this study was to evaluate the use of GM services and associated characteristics among mothers of infants in Mettu town, Southwest Ethiopia.ObjectiveTo assess the utilisation of GM service by mothers of infants in Mettu town, Southwest Ethiopia, 2021.MethodA community-based cross-sectional study was conducted among 354 randomly selected mothers with children aged 0–23 months old from 25 June to 27 July 2021 in Mettu town. EpiData V.4.6.0 was used to enter data, which were then exported to SPSS V.25 for analysis. Simple binary and multivariable logistic regression analyses were performed to identify factors associated with GM service utilisation.ResultsA total of 354 study participants were included in the study, yielding a response rate of 95.2%. The proportion of GM service utilisation was 25.2% (95% CI: 20.24% to 29.33%). In multivariable regression analysis, age of index child 0–11 months (AOR (adjusted OR)=1.58; 95% CI: 1.052 to 3.713), early postnatal care (PNC) (AOR=1.72; 95% CI: 1.657 to 6.467), middle tertile wealth status (AOR=0.108; 95% CI: 0.047 to 0.319) and lower tertile wealth status (AOR=0.073; 95% CI: 0.013 to 0.874), utilisation of family health cards (AOR=2.09; 95% CI: 1.384 to 5.343) and taking ≤30 min to reach the nearest health facility (AOR=2.23; 95% CI: 2.061 to 7.350) were significantly associated with GM service utilisation.Conclusion and recommendationIn this study, only one-fourth of mothers with children aged 0–23 months old were using GM services. GM service utilisation was found to be significantly associated with child age, early PNC visit, wealth status, utilisation of family health cards and time taking ≤30 min to reach the nearest health facility. Hence, appropriate strategies that promote and encourage GM service utilisation should be designed.
Assessment of physical fitness during pregnancy: validity and reliability of fitness tests, and relationship with maternal and neonatal health – a systematic review
Authors: Romero-Gallardo Lidia , Roldan Reoyo Olga , Castro-Piñero Jose , May Linda E , Ocón-Hernández Olga , Mottola Michelle F , Aparicio Virginia A , Soriano-Maldonado Alberto 
Published: September 2022

ObjectivesTo systematically review studies evaluating one or more components of physical fitness (PF) in pregnant women, to answer two research questions: (1) What tests have been employed to assess PF in pregnant women? and (2) What is the validity and reliability of these tests and their relationship with maternal and neonatal health?DesignA systematic review.Data sourcesPubMed and Web of Science.Eligibility criteriaOriginal English or Spanish full-text articles in a group of healthy pregnant women which at least one component of PF was assessed (field based or laboratory tests).ResultsA total of 149 articles containing a sum of 191 fitness tests were included. Among the 191 fitness tests, 99 (ie, 52%) assessed cardiorespiratory fitness through 75 different protocols, 28 (15%) assessed muscular fitness through 16 different protocols, 14 (7%) assessed flexibility through 13 different protocols, 45 (24%) assessed balance through 40 different protocols, 2 assessed speed with the same protocol and 3 were multidimensional tests using one protocol. A total of 19 articles with 23 tests (13%) assessed either validity (n=4), reliability (n=6) or the relationship of PF with maternal and neonatal health (n=16).ConclusionPhysical fitness has been assessed through a wide variety of protocols, mostly lacking validity and reliability data, and no consensus exists on the most suitable fitness tests to be performed during pregnancy.PROSPERO registration numberCRD42018117554.
Tumorous expression of NAC1 restrains antitumor immunity through the LDHA-mediated immune evasion
Authors: Ren Yijie , Kumar Anil , Das Jugal K , Peng Hao-Yun , Wang Liqing , Balllard Darby , Xiong Xiaofang , Ren Xingcong , Zhang Yi , Yang Jin-Ming , Song Jianxun 
Published: September 2022

BackgroundT cell-mediated antitumor immunity has a vital role in cancer prevention and treatment; however, the immune-suppressive tumor microenvironment (TME) constitutes a significant contributor to immune evasion that weakens antitumor immunity. Here, we explore the relationship between nucleus accumbens-associated protein-1 (NAC1), a nuclear factor of the BTB (broad-complex, Tramtrack, bric a brac)/POZ (Poxvirus, and Zinc finger) gene family, and the TME.MethodsAdoptive cell transfer (ACT) of mouse or human tumor antigen (Ag)-specific CD8+cytotoxic T lymphocytes (CTLs) was tested in an immunocompetent or immunodeficient mouse model of melanoma with or without expression of NAC1. The effects of NAC1 expression on immune evasion in tumor cells were assessed in vitro and in vivo. CRISPR/Cas9, glycolysis analysis, retroviral transduction, quantitative real-time PCR, flow cytometric analysis, immunoblotting, database analyses were used to screen the downstream target and underlying mechanism of NAC1 in tumor cells.ResultsTumorous expression of NAC1 negatively impacts the CTL-mediated antitumor immunity via lactate dehydrogenase A (LDHA)-mediated suppressive TME. NAC1 positively regulated the expression of LDHA at the transcriptional level, which led to higher accumulation of lactic acid in the TME. This inhibited the cytokine production and induced exhaustion and apoptosis of CTLs, impairing their cell-killing ability. In the immunocompetent and immunodeficient mice, NAC1 depleted melanoma tumors grew significantly slower and had an elevated infiltration of tumor Ag-specific CTLs following ACT, compared with the control groups.ConclusionsTumor expression of NAC1 contributes substantially to immune evasion through its regulatory role in LDHA expression and lactic acid production. Thus, therapeutic targeting of NAC1 warrants further exploration as a potential strategy to reinforce cancer immunotherapy, such as the ACT of CTLs.
Efficacy of ultrasound-guided single-injection erector spinae plane block for thoracoscopic wedge resection: a prospective randomized control trial
Authors: Klaibert Beau , Lohser Jens , Tang Raymond , Jew Michael , McGuire Anna , Wilson Jason 
Published: September 2022

BackgroundDespite advances in minimally invasive thoracic surgery, patients remain at risk of adverse pulmonary events with suboptimal postoperative analgesia. Novel methods of regional analgesia are warranted. Our objective was to prospectively evaluate the impact of ultrasound-guided single-injection erector spinae plane (ESP) block with ropivacaine compared with placebo control on standard of care postoperative recovery in subjects undergoing video-assisted thoracoscopic surgery (VATS) wedge resection.MethodsThis prospective, randomized, placebo-controlled, double-blinded study was conducted at a tertiary thoracic surgical center. Consecutive subjects undergoing VATS wedge resection were randomized to receive a single-injection ESP block with 0.5% ropivacaine or 0.9% saline placebo, in addition to the current standard of care of multimodal analgesia including patient-controlled analgesia and surgical local anesthetic wound infiltration. The primary outcome was difference in 40-point Quality of Recovery (QoR-40) on day 1 postoperatively. The secondary outcomes included opioid consumption, Visual Analog Pain Scale (VAS) score, time spent in the postanesthesia care unit (PACU), and block-related and postoperative complications.ResultsEighty subjects were enrolled, 40 in each group, with 76 completing follow-up (38 subjects in each group). There was no difference in the median QoR-40 score between groups, 169.5 for the ropivacaine group and 172.5 for the control group (difference 3, p=0.843). No significant differences existed between groups in all secondary outcomes, with the exception of the ropivacaine group having lower VAS pain scores measured at 1 hour postoperatively and a shorter duration of stay in the PACU of 117 min.ConclusionsFollowing VATS wedge resection, the addition of an ESP block with ropivacaine to standard multimodal analgesia is unlikely to add meaningful clinical value.Trial registration numberNCT03419117.