bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clearance flow field characteristics of Kaplan turbine under different flange clearance
Authors: Zhang Y L , Wu Y B , Wei J W , Wang Z W , Zhou L J 
Published: June 2022

Abstract
Flange clearance flow is a complex flow phenomenon in axial flow units. Clearance vortex and vortex cavitation caused by it have always been the focus of research at home and abroad. In this paper, the steady cavitation calculation of Kaplan turbine with blade tip clearance width of 0.5mm, 1mm and 2mm is carried out under four working conditions. The energy characteristics, clearance flow characteristics and cavitation characteristics of the runner under different clearances are analyzed. Results show that: The energy characteristics of the runner domain are greatly affected by the tip clearance width. When ω/D increases by 1%, the power coefficient P
* decreases by 0.83%~1.45%, and the efficiency η decreases by 0.3%~0.5%. With the increase of the clearance width, the diameter of the clearance leakage vortex band becomes thicker, and the vortex length gradually extends to the outflow edge of the blade, and the included Angle with the blade suction surface gradually increases. The cavitation type of the tip area is mostly leaking vortex cavitation when there is a tiny clearance. Clearance cavitation and leakage vortex cavitation grow as tip clearance rises, and the interaction between them is reinforced.
Pressure fluctuation measurement in pressure vessels
Authors: Kapali A , Neopane H P , Chitrakar S , Shrestha K P , Sapkota P 
Published: June 2022

Abstract
Pressure vessels are mechanical devices that act as a reservoir of fluids at pressure more or less than atmospheric pressure. This research focuses on the application of the pressure vessel for hydraulic testing of hydro turbines to maintain uniform velocity profile and to suppress the pressure surge in the pipeline. An initial assumption for the design of a thin-walled horizontal type pressure vessel with the ellipsoidal type of head is based on the mathematical relations as per ASME code, Section VIII, Division I, for an operating pressure of 0.3 MPa and design pressure of 0.6 MPa. The pressure vessel has been placed, close to outlet of the main pump to prevent the water hammering in the pipeline. The measurement of the pressure fluctuations at the inlet, outlet, and inside of the vessel, due to the dynamic action of fluid forced by the pump are recorded. The study attempts to relate the use of pressure vessels to generate stable flow and pressure at the outlet for hydraulic testing of turbines.
Turbine blade strike tests for evaluation and optimization of fish-friendly turbine
Authors: Meng L , Chen R , Wang X , Zhang C Y , Zheng Y , Tian Y J 
Published: June 2022

Abstract
Widening the knowledge for fish injury and mortality mechanism caused by pressure, shear stress and blade strikes inside turbine was constructive for optimizing fish-friendly turbine design and turbine operation regime. A special designed test equipment was applied for simulating the rotating blade inside turbine passage, anesthetized fish (crucian carp) was placed on the route of the blade for strike tests. The fish length, blade thickness, strike angle, and strike speed were independent variables during the tests, the injury rate, degree of injury and mortality rate were analysed according to observation or anatomical examination after repeated tests. The injury types were classified into: imbalance, ribs broken, gill cover broken, internal hemorrhage and death. The injury severity was directly affected by strike speed under same blade thickness and fish length. The ratio of blade thickness and fish length also affect the injury rate. Multiple injuries can be observed on one fish after tests, and combined injuries are more likely to lead to death. In the fish-friendly turbine design, blade thickness in the leading edge and blade numbers shall be carefully considered and the rotational speed shall be calculated.
Analysis and research on sluice gate flow of a hydropower station under different working conditions
Authors: Xu Yang , Li Zheng gui , Gong Chengyong , Guan Zhijun , Ma Biao 
Published: June 2022

Abstract
The rationality design of the sluice gate directly influences the flood control capacity of hydropower stations. To demonstrate the rationality of the creation of the spillway gate of a hydropower station in the Yellow River Basin, this paper adopts the method of combining model test with a mathematical model to study the pressure, flow velocity, and water level changes of the spillway gate of the hydropower station under the working conditions of check flood and design flood. The research results show that there is no negative pressure in the whole flood discharge sluice dam section under check flood and desert flood conditions. The pressure characteristics of each area of the sluice floor are good, and the velocity distribution is uniform. However, the outflow velocity of the reinforced cage section is greater than the anti-scour velocity of the river under the two working conditions, which impacts the downstream river, so it is necessary to increase the length of the reinforced cage section appropriately. The water flow falls twice in the spillway dam section. The initial position of the first fall is the same under two working conditions. However, the falling depth decreases with the decrease of reservoir water level. The second fall position moves backward with the reduction of the water level. This paper provides a theoretical reference for the demonstration of flood discharge capacity of other hydropower stations through the analysis and research of the flood discharge sluice state of this hydropower station.
Green Ammonia as a flexible hydro-electricity carrier for Nepal
Authors: Neupane B , Bhattarai S , Shah A K , Thapa B S 
Published: June 2022

Abstract
An increase in the installed capacity of Hydroelectricity in Nepal in 2022 by 122% compared to that in 2021 is a major milestone in power production in the country. This increase in electricity production will make the country self-sufficient in electricity for the first time in the last three decades. The future growth of hydropower installations in Nepal is expected to rise much beyond the local consumption and is forecasted to reach as much as 3500 MW surplus energy by 2028. Most of the hydropower projects built and under construction are run-off -river type, due to which the power generation is highly seasonal and results in the poor load factor. There is a need for Nepal to plan the effective use of surplus power and the seasonality variation of hydro-energy. Producing green ammonia from hydroelectricity and its utilization in industries and commercial sectors can be one of the options for the storage and transportation of surplus hydroelectricity in Nepal in the future. With the flexibility of usage, and given the fact that the required technologies and infrastructures for safer transportation, distribution, and ammonia application are already in place; ammonia can be a viable option to be a hydro-electricity carrier of the future in Nepal. This paper studies the potentials of ammonia as a hydroelectricity carrier and its application as a chemical commodity in the industries and transportation sector. The different chemical attributes of ammonia along with the production technologies, economies of ammonia production, storage, transportation, and its subsequent application are studied. This study concludes that utilization of ammonia as a hydro-energy carrier and its usage as a chemical commodity in the industries, green fuel in the transportation sector can be a good opportunity to lead the country towards sustainable and renewable energy economy.
Time-domain model and optimization for single-axis kinetic energy harvesters driven by arbitrary non-harmonic excitation
Authors: Struwig Michael N , Niesler Thomas , Wolhuter Riaan , Strauss Johann 
Published: June 2022

Abstract
Energy harvesting is employed to extend the life of battery-powered devices, however, demanding applications such as wildlife tracking collars, the operating conditions impose size and weight constraints. They also only provide non-harmonic mechanical motion, which renders much of the existing literature inapplicable, which focuses on harvesting energy from harmonic mechanical sources. As a solution, we propose an energy harvesting architecture that consists of variable number of evenly-spaced magnets, forming a fixed assembly that is free to move through a series of evenly-spaced coils, and is supported by a magnetic spring. We present an electromechanical model for this architecture, and evolutionary optimization process that finds the model parameters which describe the time-domain behaviour observed in ground truth measurements. The resulting model can predict the time-domain behaviour of the energy harvester for any configuration of the proposed architecture and for any mechanical excitation. We also propose an optimization process that, using the electromechanical model, optimizes the energy harvester configuration to maximize the power delivered to a resistive load. The resulting optimized harvester design is specific to the particular kind of non-harmonic mechanical excitation to which it will be exposed. To demonstrate the effectiveness of our proposed model and optimization procedure, we constructed four energy harvesters, each with different configurations, and compared their measured behaviour with that predicted by the model, given an excitation that approximates footstep-like motion. We show that the model predictions were consistently within 25% of the RMS load voltage. We then synthesize an optimal energy harvester using the proposed optimization process. The resulting optimal design was constructed and tested using the same footstep-like excitation, and delivered an average power of 1.526 mW to a 30Ωload. This is a 2.8-fold improvement over an unoptimized reference design. We conclude that our proposed behavioural model and optimization process allows the determination of energy harvester designs that are optimized for a non-harmonic and specific input excitation.
A Multicenter, Randomized, Double-Blind, Split-Body Clinical Trial Evaluating the Efficacy and Outcomes of a Topical Product Pre and Post Aesthetic Surgical Body Procedures
Authors: Casas Laurie A , Claytor R Brannon , Zeidler Kamakshi R , Shridharani Sachin M , Cohen Steven R , Khanna Julie J , Gould Daniel J , Yates Essie K , Lultschik Shantel , Bell Michaela , Widgerow Alan D 
Published: June 2022

Abstract

Background
Skin preconditioning prior to and following procedures, has previously been demonstrated to hasten and optimize healing, and decrease the symptoms and signs associated with invasive surgery. These trials involved the use of multiple topical products. In an effort to control costs and to increase patient compliance, a single surgical product was developed, with actives aimed at decreasing swelling, bruising, induration, and internal fibrous banding.

Objectives
This multi-center trial was designed to measure the efficacy of this single product in these mentioned parameters.

Methods
A double-blind, randomized, split body, clinical study was undertaken in 29 patients involving 38 surgical procedures. Assessments included photography, biopsies, ultrasound imaging, and blinded investigator and participant assessments.

Results
Differentiated results between test comparator sides became apparent at postop day 10-14 (as previously observed). Thus, blinded investigator and participant assessment scores demonstrated statistical significance exclusive to the test product side at postop day 10-14 for ecchymoses and then extending to skin discoloration, edema, induration and subcutaneous fibrous banding, at weeks 3, 4, 6, and 12. Ultrasound evaluation confirmed the earlier dissolution of fibrous banding on the test side in the subcutaneous tissue at the 3-6-week postop period. In addition, biopsies assessing the pre-conditioned period prior to surgery confirmed that the topical test product stimulated a remodeled extracellular matrix without comparative changes on the opposite side.

Conclusions
A single peri-surgical product designed for the use with invasive surgery produced significant differences in ecchymosis, skin discoloration, edema, induration and ongoing resolution of fibrous banding over many weeks. This study validation provides an additional adjunct to surgical procedures.

Level of Evidence: 2
Microbial Cell-Free DNA Identifies the Causative Pathogen in Infective Endocarditis and Remains Detectable Longer Than Conventional Blood Culture in Patients with Prior Antibiotic Therapy
Authors: Eichenberger Emily M , Degner Nicholas , Scott Erick R , Ruffin Felicia , Franzone John , Sharma-Kuinkel Batu , Shah Pratik , Hong David , Dalai Sudeb C , Blair Lily , Hollemon Desiree , Chang Eliza , Ho Carine , Wanda Lisa , de Vries Christiaan R , Fowler Vance G , Ahmed Asim A 
Published: June 2022

Abstract

Background
The diagnosis of infective endocarditis (IE) can be difficult, particularly if blood cultures fail to yield a pathogen. This study evaluates the potential utility of microbial cell-free DNA (mcfDNA) as a tool to identify the microbial etiology of IE.

Methods
Blood samples from patients with suspected IE were serially collected. mcfDNA was extracted from plasma and underwent next-generation sequencing. Reads were aligned against a library containing DNA sequences belonging to &gt;1400 different pathogens. mcfDNA from organisms present above a statistical threshold were reported and quantified in molecules per milliliter (MPM). Additional mcfDNA was collected on each subject every 2–3 days for a total of 7 collections or until discharge.

Results
Of 30 enrolled patients with suspected IE, 23 had definite IE, 2 had possible IE, and IE was rejected in 5 patients by modified Duke Criteria. Only the 23 patients with definite IE were included for analysis. Both mcfDNA and blood cultures achieved a sensitivity of 87%. The median duration of positivity from antibiotic treatment initiation was estimated to be approximately 38.1 days for mcfDNA versus 3.7 days for blood culture (proportional odds, 2.952; P = .02771), using a semiparametric survival analysis. mcfDNA (log10) levels significantly declined (−0.3 MPM log10 units, 95% credible interval −0.45 to −0.14) after surgical source control was performed (pre- vs postprocedure, posterior probability &gt;0.99).

Conclusion
mcfDNA accurately identifies the microbial etiology of IE. Sequential mcfDNA levels may ultimately help to individualize therapy by estimating a patient’s burden of infection and response to treatment.
FAM19A4/miR124-2 Methylation Testing and Human Papillomavirus (HPV) 16/18 Genotyping in HPV-Positive Women Under the Age of 30 Years
Authors: Vink Frederique J , Meijer Chris J L M , Hesselink Albertus T , Floore Arno N , Lissenberg-Witte Birgit I , Bonde Jesper H , Pedersen Helle , Cuschieri Kate , Bhatia Ramya , Poljak Mario , Oštrbenk Valenčak Anja , Hillemanns Peter , Quint Wim G V , del Pino Marta , Kenter Gemma G , Steenbergen Renske D M , Heideman Daniëlle A M , Bleeker Maaike C G 
Published: June 2022

Abstract

Background
High-grade squamous intraepithelial lesions (HSIL) or cervical intraepithelial neoplasia (CIN) grade 2/3 lesions in human papillomavirus (HPV)–positive women &lt;30 years of age have high spontaneous regression rates. To reduce overtreatment, biomarkers are needed to delineate advanced CIN lesions that require treatment. We analyzed the FAM19A4/miR124-2 methylation test and HPV16/18 genotyping in HPV-positive women aged &lt;30 years, aiming to identify CIN2/3 lesions in need of treatment.

Methods
A European multicenter retrospective study was designed evaluating the FAM19A4/miR124-2 methylation test and HPV16/18 genotyping in cervical scrapes of 1061 HPV-positive women aged 15–29 years (690 ≤CIN1, 166 CIN2, and 205 CIN3+). A subset of 62 CIN2 and 103 CIN3 were immunohistochemically characterized by HPV E4 expression, a marker for a productive HPV infection, and p16ink4a and Ki-67, markers indicative for a transforming infection. CIN2/3 lesions with low HPV E4 expression and high p16ink4a/Ki-67 expression were considered as nonproductive, transforming CIN, compatible with advanced CIN2/3 lesions in need of treatment.

Results
FAM19A4/miR124-2 methylation positivity increased significantly with CIN grade and age groups (&lt;25, 25–29, and ≥30 years), while HPV16/18 positivity was comparable across age groups. FAM19A4/miR124-2 methylation positivity was HPV type independent. Methylation-positive CIN2/3 lesions had higher p16ink4a/Ki-67-immunoscores (P = .003) and expressed less HPV E4 (P = .033) compared with methylation-negative CIN2/3 lesions. These differences in HPV E4 and p16ink4a/Ki-67 expression were not found between HPV16/18–positive and non-16/18 HPV–positive lesions.

Conclusions
Compared with HPV16/18 genotyping, the FAM19A4/miR124-2 methylation test detects nonproductive, transforming CIN2/3 lesions with high specificity in women aged &lt;30 years, providing clinicians supportive information about the need for treatment of CIN2/3 in young HPV-positive women.
Incidence, Attributable Mortality, and Healthcare and Out-of-Pocket Costs of Clostridioides difficile Infection in US Medicare Advantage Enrollees
Authors: Yu Holly , Alfred Tamuno , Nguyen Jennifer L , Zhou Jingying , Olsen Margaret A 
Published: June 2022

Abstract

Background
US attributable Clostridioides difficile infection (CDI) mortality and cost data are primarily from Medicare fee-for-service populations, and little is known about Medicare Advantage Enrollees (MAEs). This study evaluated CDI incidence among MAEs from 2012 to 2019 and determined attributable mortality and costs by comparing MAEs with and without CDI occurring in 2018.

Methods
This retrospective cohort study assessed CDI incidence and associated mortality and costs for eligible MAEs ≥65 years of age using the de-identified Optum Clinformatics Data Mart database (Optum; Eden Prairie, Minnesota, USA). Outcomes included mortality, healthcare utilization, and costs, which were assessed via a propensity score–matched cohort using 2018 as the index year. Outcome analyses were stratified by infection acquisition and hospitalization status.

Results
From 2012 to 2019, overall annual CDI incidence declined from 609 to 442 per 100 000 person-years. Although the incidence of healthcare-associated CDI declined overall (2012, 53.2%; 2019, 47.2%), community-associated CDI increased (2012, 46.8%; 2019, 52.8%). The 1-year attributable mortality was 7.9% (CDI cases, 26.3%; non-CDI controls, 18.4%). At the 2-month follow-up, CDI-associated excess mean total healthcare and out-of-pocket costs were $13 476 and $396, respectively. Total excess mean healthcare costs were greater among hospitalized (healthcare-associated, $28 762; community-associated, $28 330) than nonhospitalized CDI patients ($5704 and $2320, respectively), whereas total excess mean out-of-pocket cost was highest among community-associated hospitalized CDI patients ($970).

Conclusions
CDI represents an important public health burden in the MAE population. Preventive strategies and treatments are needed to improve outcomes and reduce costs for healthcare systems and this growing population of older US adults.
Population-Weighted Seroprevalence From Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection, Vaccination, and Hybrid Immunity Among US Blood Donations From January to December 2021
Authors: Busch Michael P , Stramer Susan L , Stone Mars , Yu Elaine A , Grebe Eduard , Notari Edward , Saa Paula , Ferg Robyn , Manrique Irene Molina , Weil Natalia , Fink Rebecca V , Levy Matthew E , Green Valerie , Cyrus Sherri , Williamson Phillip C , Haynes James , Groves Jamel , Krysztof David , Custer Brian , Kleinman Steve , Biggerstaff Brad J , Opsomer Jean D , Jones Jefferson M 
Published: June 2022

Abstract

Background
Previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and coronavirus disease 2019 (COVID-19) vaccination, independently and combined (“hybrid immunity”), result in partial protection from subsequent infection and strong protection from severe disease. Proportions of the US population who have been infected, vaccinated, or have hybrid immunity remain unclear, posing a challenge for assessing effective pandemic mitigation strategies.

Methods
In this serial cross-sectional study, nationwide blood donor specimens collected during January–December 2021 were tested for anti-spike and anti-nucleocapsid antibodies, and donor COVID-19 vaccination history of ≥1 dose was collected. Monthly seroprevalence induced from SARS-CoV-2 infection, COVID-19 vaccination, or both, were estimated. Estimates were weighted to account for demographic differences from the general population and were compared temporally and by demographic factors.

Results
Overall, 1 123 855 blood samples were assayed. From January to December 2021, the weighted percentage of donations with seropositivity changed as follows: seropositivity due to vaccination without previous infection, increase from 3.5% (95% confidence interval, 3.4%–3.7%) to 64.0%, (63.5%–64.5%); seropositivity due to previous infection without vaccination, decrease from 15.6% (15.2%–16.0%) to 11.7% (11.4%–12.0%); and seropositivity due to hybrid immunity, increase from 0.7% (0.6%–0.7%) to 18.9% (18.5%–19.3%). Combined seroprevalence from infection, vaccination, or both increased from 19.8% (19.3%–20.2%) to 94.5% (93.5%–94.0%). Infection- and vaccination-induced antibody responses varied significantly by age, race-ethnicity, and region, but not by sex.

Conclusions
Our results indicate substantial increases in population humoral immunity from SARS-CoV-2 infection, COVID-19 vaccination, and hybrid immunity during 2021. These findings are important to consider in future COVID-19 studies and long-term pandemic mitigation efforts.
In vivo and in vitro cartilage differentiation from embryonic epicardial progenitor cells
Authors: Marin Sedeno E , Palmquist-Gomes P , Rico-Llanos GA , Ruiz-Villalba A , Perez-Pomares JM , Guadix JA 
Published: June 2022

Abstract

Funding Acknowledgements
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Spanish Ministry of Science and Universities and Consejería de Salud y Familias, Junta de Andalucía.
The presence of cartilage tissue in embryonic and adult hearts of various vertebrate species is a well-recorded fact. However, while the embryonic neural crest has been historically considered as the main source of cardiac cartilage, recently reported results on the wide connective potential of epicardial lineage cells suggest they could also differentiate into chondrocytes. During heart embryogenesis, the epicardial epithelium forms over the originally bare myocardial surface from epicardial progenitor (proepicardial) cells to then give rise to a large population of mesenchymal Epicardial-Derived Cells (EPDCs) that will crucially contribute to the building, growth and maturation of the ventricle and atrioventricular cardiac structures. In this work, we describe the formation of cardiac cartilage clusters from proepicardial cells, both in vivo and in vitro. Our findings report, for the first time, cartilage formation from epicardial progenitor cells in the embryonic heart, and strongly support the concept of proepicardial cells as multipotent connective progenitors. These results are relevant to our understanding of cardiac cell complexity and responses to pathologic stimuli.