bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Inlet Air Pre-Cooling of Natural Draft Dry Cooling Towers-Wetted Medium Issue
Authors: He Suoying , Zhang Guanhong , Xu Yi , Sun Fengzhong 
Published: September 2017

Dry cooling towers are an alternative cooling method when large quantities of water are not available. Examples of the proposed applications are the enhanced geothermal and concentrated solar thermal (CST) power plants in arid or semi-arid areas, like south-western United States, Australia, western Asia, north-western China and the rest of the world. Natural draft dry cooling towers (NDDCTs) have received widespread attention because they do not consume water, have low maintenance requirements and cause small parasitic losses. Unfortunately, the performance of a NDDCT is severely reduced when the ambient air is hot, which is because the NDDCT is driven by buoyancy effect and relies solely on air to cool the working fluid. The present study introduces inlet air pre-cooling using wetted media, which combines dry and wet cooling. The wet cooling system only operates at high ambient temperatures to assist dry cooling. However, wetted-medium cooling introduces extra pressure drop which reduces the air flow passing through the NDDCT and thus impairs the tower heat rejection. To this end, this paper takes into account the trade-off between the wetted-medium cooling and the extra pressure drop. Early studies find that the performance of NDDCTs can be improved by wetted-medium evaporative pre-cooling when the ambient air is hot and dry. However, the pre-cooling enhancement is seasonal-dependent and is significantly affected by wetted media. To further investigate the effect of wetted medium type on pre-cooling performance, the current study simulates a pre-cooled NDDCT using five selected wetted media (i.e., three film and two trickle media) based on a self-developed MATLAB program. The innovations of the current study are: (1) two typical types of wetted media with the potential of evaporative pre-cooling are comparatively studied to give suggestions for future pre-cooling design; (2) the characteristics of wetted media suitable for evaporative pre-cooling of NDDCTs are summarized.
The simulation finds that the media with high or low cooling efficiencies and pressure drops are not promising while those media with middle cooling efficiencies and pressure drops intend to produce much performance enhancement of the studied NDDCT. The film medium, Cellulose7060 with pressure drops of 28.6–272.1 Pa/m and cooling efficiency range of 44.7–88.5% is most promising for such pre-cooling enhancement. For the studied NDDCT, the critical temperatures below which the tower performance does not benefit but is hindered by wetted-medium pre-cooling are 28, 16, 30, 26 and 26°C for cellulose7090, cellulose7060, PVC1200, Trickle125 and Trickle100, respectively (ambient humidity of 20% and medium thickness of 200mm). The pre-cooling enhancements can go up to 100% by 200mm-thick cellulose7060 at extreme hot and dry climate (i.e., ambient temperature of 50°C and humidity of 20%). The simulation will give instructions for the design of pre-cooled NDDCTs.
A Bladeless Turbocompressor Concept: Shear Driven Gas Compression With Deformable Structures: Part 2 — Operating Principles and Theory
Authors: Heshmat Hooshang , Córdova José Luis 
Published: September 2017

The theory underlying a novel method of gas compression driven by shear flow for next generation turbo-machinery is presented. The concept is based on the conversion of shaft power into hydrodynamic pressure and fluid flow that occur in the shear flow between a smooth rotating disk and a compliant surface counterface. This also holds for the inverse process, where gas expansion through the gap between the compliant surface and a shaft-mounted disk converts gas pressure into rotating power and torque.
This is a logical evolutionary step that leverages the proven functionality of self-actuated fluid film compliant foil bearings and seals which operate in the hydrodynamic regime. Thus, as in these devices, the process of compression induced by shear flow is dominated by the balance between pressure and viscous forces which are in turn enhanced and controlled by tribological effects arising between the fluid film and the geometry of the counterface compliant surface.
A model based on the compressible Reynolds equation coupled to the thin-plate theory formulation for compliant foil deflection is presented and parametrically solved to predict pressure, flow rate, and shear losses. The smooth disk and four-pad (sectored) compliant counterface effective size (7.6 mm < r < 14.1 mm), disk operating speed (50,000 to 360,000 rpm), nominal initial gap (0.03 mm < h0 < 0.635 mm), and overall operating conditions chosen for the parametric study correspond to those envisioned for eventual practical integration of miniaturized external combustion bladeless gas turbine engines and turbocompressors. Theoretical performance curves reporting flow versus pressure as well as compression power requirements versus speed were obtained. The predictions of the analysis are compared to results obtained experimentally on a proof of concept engine and presented in a companion paper.
The simplicity of the bladeless geometry makes it amenable to deployment in multistage configurations, so that in conjunction with its foil bearing predecessors, this novel technology will result in low cost, ultra-high speed, high specific power and power density, high efficiency, oil-free and maintenance-free engines — attractive for many practical applications, ranging from military micro-UAV propulsion and portable power systems, to domestic combined heat and power turboalternators, and even micro-compressors for portable medical devices. As a point of reference, it is anticipated that a 10-stage bladeless compressor based on a compression stage as described herein would have a size comparable to that of a 355 mL soda can delivering a flow of 1 kg/min of compressed air.
Studies on Several Fly Ashes and Their Modified Materials for CO2 Capture
Authors: Yan Junjie , Zhao Chuanwen , Wang Peng , Lu Ping 
Published: September 2017

In recent years, global warming and climate change caused by the greenhouse gas emissions has given rise to widespread concerns. CO2 has been considered as the principal greenhouse gas of interest, and fossil-fuel-fired power plants have been deemed as the largest stationary sources of CO2 emission. It is imperative to capture CO2 from these sources to reduce the global CO2 emissions. Lately, capturing CO2 from flue gas using solid absorbents shows promising for CO2 abatement. For the cost-effective CO2 capture process and the recycling of environmental pollutants, deprecated resources have been utilized for CO2 capture from flue gas.
In this work, fly ashes derived from different raw materials were tried as solid CO2 sorbents for flue gas treatment. To improve their CO2 capture capacities, the ashes were modified by different polyamines. An experimental demonstration on CO2 capture behaviors of fresh ashes and modified sorbents in simulated flue gas atmosphere of 40°C, 15% CO2 + 15% H2O and balanced N2 was presented in detail with a fixed-bed reactor system. CO2 capture capacities of fresh ashes were calculated as 0.56 mmolCO2/g, 0.32 mmolCO2/g, 0.44 mmolCO2/g and 0.83 mmolCO2/g, respectively. By contrast, CO2 capture capacities of amine-modified samples had been enhanced as 0.38 mmolCO2/g, 0.65 mmolCO2/g, 1.07 mmolCO2/g, 0.85 mmolCO2/g and 1.17 mmolCO2/g. The optimal sample of TEPA-modified biomass ash (TEPA-BA) with CO2 capture capacity of 1.17mmolCO2/g was screened. The optimal candidate was then selected for further investigation of the effects of temperature, CO2 concentration and H2O concentration on its CO2 capture behaviors. The results indicated that CO2 capture capacity would increase with the increase of temperature in the range of 30 to 40 °C and decrease with the increase of temperature in the range of 40 to 60°C, increase with the increase of CO2 concentration in the range of 5% to 20%, increase with the increase of H2O concentration in the range of 0% to 15% and decrease with the increase of H2O concentration in the range of 15% to 20%. The results in this work could provide basic data as a guidance for further applying the sorbents in practical operations.
Evaluation and Application of Hard Coatings for Steam Turbine
Authors: Yan Liang , Nakatani Yujiro , Yamada Masayuki , Abe Toru , Kitaguchi Koichi , Ono Yasunori , Yamamoto Kenji , Munemasa Jun 
Published: September 2017

In order to improve solid particle erosion (SPE) resistance for steam turbine blades and nozzles, in corporation with Kobe Steel, Ltd., evaluation of hard coatings of TiN and TiAlN deposited by the Arc Ion Plating (AIP®) process was performed to verify applicability to an actual steam turbine. The results of high-temperature steam oxidation tests and room-temperature sand erosion tests showed that the TiAlN coating had high-temperature stability superior to that of the TiN coating, and erosion resistance far superior to that in the case of the conventional CrC thermal spray coating and boronizing treatment. High-temperature fatigue and creep tests showed that the characteristic strength of the blade material with the TiAlN coating was equal or superior to that of the base blade material.
On the basis of the results of comprehensive evaluation, it was confirmed that the TiAlN hard coating has excellent applicability to an actual steam turbine and it was successfully applied to steam turbine blades of power plants in Japan.
Healing Response of a Structural Hamstring Injury: Perfusion Imaging 8-Week Follow-Up
Authors: Kellermann Marion , Lutter Christoph , Hotfiel Thilo 
Published: September 2017

Context: Hamstring injuries are frequently observed in various sports disciplines both in elite and recreational sport. Objective: To quantify intramuscular tissue perfusion via contrast-enhanced ultrasound in the acute phase and during the healing of a structural muscle injury confirmed by high-resolution magnetic resonance imaging. Design: Case study. Setting: Laboratory environment. Patient: A 32-year-old wakeboarder (height = 176 cm, body weight = 76 kg, and body mass index = 24.5 kg/m2) with an acute indirect muscle injury of the semimembranosus muscle. Main Outcome Measures: Average values of quantifiable contrast-enhanced ultrasound, represented as peak enhancement and wash-in area under the curve, as well as conventional ultrasound, 1.5T magnetic resonance imaging were assessed at 48-hour, 3-week, and 8-week postinjury. Results: Average values of the quantitative perfusion analysis at 48-hour and 8-week postinjury revealed an approximate 5-fold increase in peak enhancement, and the wash-in area under the curve increased more than 3-fold in the center of the lesion. Magnetic resonance imaging, performed 48 hours after the injury to gather reference data as gold standard, revealed a grade III structural muscle tear. Conclusions: The authors are able to demonstrate significant changes in intramuscular tissue perfusion in the center of the structural lesion as well as in the adjacent tissue. Quantifiable contrast-enhanced ultrasound seems to be able to gather relevant data for the assessment and monitoring of muscle injuries and could be established as a valuable tool for further studies focusing on healing processes or therapeutic interventions.
Economic impact of ulipristal acetate on surgical procedures for uterine fibroids in France
Authors: Fernandez Hervé , Jourdain Olivier , Villefranque Vincent , Lehmann Matthieu , Lafuma Antoine , Trancart Matthieu 
Published: September 2017

ObjectiveTo assess the budget impact of using ulipristal acetate (UPA) 5 mg to treat women with uterine fibroids (UF) causing moderate to severe symptoms.DesignWe modelled trends in the number of surgical procedures for symptomatic UF, with and without the use of UPA for preoperative or intermittent treatment and assessed the budget impact of UPA use from the French national healthcare insurance system perspective.SettingA French national hospital database (PMSI) that records admissions and relative procedures to public and private hospitals.ParticipantsWomen eligible for surgical procedures for uterine fibroids.Main outcome measuresEconomic impact of UPA treatment.ResultsThis study based on observational retrospective data shows that the current use of UPA in its preoperative indication was associated with 5645 fewer surgeries from 2013 to 2015. Extrapolation suggests 17 885 fewer surgeries from 2016 to 2019. Overall, preoperative use of UPA results in substantial cost savings for the French national healthcare insurance system, with a cumulated budget impact estimated at €−5 million from 2013 to 2015 and €−13.5 million from 2016 to 2019. In addition, treating women nearing the menopause (≥48 years old) with intermittent treatment from 2017 to 2019 could produce an incremental cost saving of €19 million.ConclusionsThis study shows that the use of UPA in women eligible for surgical procedures for UF is associated with considerable savings for the French national healthcare insurance system in both preoperative and intermittent indications by decreasing the need to perform surgeries.
Impact of chronic obstructive pulmonary disease on patients with aortic aneurysms: a nationwide retrospective cohort study in Taiwan
Authors: Liao Kuang-Ming , Chen Chung-Yu 
Published: September 2017

ObjectivesAortic aneurysm (AA) is a leading cause of death worldwide. Chronic obstructive pulmonary disease (COPD) is a risk factor for AA, and the prognoses of COPD patients with AA who underwent/did not undergo an operation warrant investigation.DesignA nationwide retrospective cohort study.SettingWe included patients with AA older than 18 years who received their first AA diagnosis between 2005 and 2011 in Taiwan.ParticipantsThis study enrolled 3263 COPD patients with AA before propensity score matching and 2127 COPD patients with AA after propensity score matching.Outcome measuresThe main outcomes were all-cause mortality and rehospitalisation for AA or operation. The outcomes of COPD patients with AA and COPD patients without AA during an 8-year follow-up period were examined using Cox proportional hazards models.ResultsIn the AA population, patients with COPD showed higher rates of mortality and rehospitalisation than patients without COPD with adjusted HRs of 1.12 (95% CI 1.03 to 1.22) and 1.11 (95% CI 1.01 to 1.23), respectively, after propensity score matching. Analysis of the patients who underwent an operation revealed that the rates of mortality of COPD and non-COPD patients were not significantly different. In contrast, among the patients who did not receive an operation, patients with COPD showed a higher mortality rate than patients without COPD with an adjusted HR of 1.11 (95% CI 1.0 to 1.22).ConclusionsThe outcomes of COPD patients with AA undergoing an operation were improved, but the mortality rate of non-COPD patients with AA remained high. An effective treatment to reduce mortality in this group warrants further investigation.
Effect of Baduanjin exercises on elevated blood lipid levels of middle-aged and elderly individuals: protocol for a systematic review and meta-analysis of randomised controlled trials
Authors: Wen Junmao , Lin Tong , Jiang Chenguang , Peng Rui , Wu Wei 
Published: September 2017

ObjectiveTo assess the safety and effect on elevated blood lipid levels of Baduanjin exercises in middle-aged and elderly individuals.MethodsA systematic literature search for articles up to March 2017 will be conducted using seven databases: PubMed, Embase, Cochrane Library, Chinese National Knowledge Infrastructure, Chinese Science and Technology Periodicals Database, Chinese BioMedical Database and Wanfang Data. Inclusion criteria are randomised controlled trials of Baduanjin exercises that examine blood lipid levels in middle-aged and elderly individuals. The primary outcome measures will be total cholesterol, triglycerides, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol. Stata V.13.0 software will be used for data synthesis, sensitivity analysis, metaregression, subgroup analysis and risk of bias assessment. A funnel plot will be developed to evaluate reporting bias and Begg and Egger tests will be used to assess funnel plot symmetries. We will use the Grading of Recommendations Assessment, Development and Evaluation system to assess the quality of evidence.Ethics and disseminationThis systematic review will be submitted to a peer-reviewed journal. Our findings will provide information about the safety of Baduanjin exercises for middle-aged and elderly individuals and their effect on elevated blood lipid levels.Trial registration numberPROSPERO CRD 42017060613.
Study protocol for a matter of heart: a qualitative study of patient factors driving overuse of cardiac catheterisation
Authors: Herwig Anna , Weltermann Birgitta 
Published: September 2017

IntroductionOveruse of cardiac catheterisation (CC) for stable coronary artery disease (CAD) is documented in Germany and other regions, although percutaneous coronary interventions do not provide a benefit over medical therapy for stable patients. Various studies investigated health system, physician and patient factors driving non-adherence to guidelines which recommend a stepwise approach with invasive procedures only in case of signs of ischaemia in non-invasive testing. In a larger-scale project, we aim to better understand the patients’ perspective in order to develop an intervention that enhances patient’s acceptance of this stepwise diagnostic approach for stable CAD. As a first step, this qualitative study aims to identify patient factors that prevent and promote the described overuse.Methods and analysisThe exploratory qualitative interview study will include about 20 patients with stable CAD and a history of acute coronary syndrome from two German teaching practices. Narrative, structured interviews designed to last 30 to 90 min will be conducted. The interviews will be analysed using qualitative content analysis by Mayring. The analysis will address the following questions: (1) What are reasons for stable patients to undergo CC? (2) How do patients deal with their heart disease (secondary prevention)? (3) Which processes do patients describe regarding decision-making for non-invasive and invasive coronary procedures? (4) What information needs exist on behalf of patients to better understand the stepwise diagnostic approach outlined in guidelines and thereby avoid low-appropriate CCs? Based on these data, empirical typification will be conducted.Ethics and disseminationEthical approval for the study was obtained. All participants will provide written informed consent. Data will be pseudonymised for analysis. The findings will contribute to the development of an appropriate intervention. Results will be disseminated by conference presentations and journal publications.
Increased efficiency in biomimetic Lewis acid–base pair catalyzed monoacylation of diols by acyl phosphate monoesters
Authors: Li Yuyang , Kluger Ronald 
Published: September 2017

Acyl phosphate monoesters are biomimetic acylation reagents that require coordination to metal ions to react with cis-diol substrates in water. With lanthanide catalysts, outcomes are compromised by (1) the competitive lanthanide-promoted hydrolysis of the acyl phosphate reagents as well as by (2) the high affinity of lanthanum ions for the phosphate monoester by-product. Based on analysis of the mechanism of the process, optimizing reaction conditions can selectively inhibit the lanthanum-promoted hydrolysis of acyl phosphate monoesters. Furthermore, using zinc salts and lead salts in place of lanthanides enhances the reactivity of the reactants and causes less complexation of the metal ion with the by-products.
TUNGSTEN OXIDES FORMATION ON THE INTERFACE OF THE CEMENTED CARBIDE AND THE INCONEL 182 OVERLAYS AT ELEVATED TEMPERATURE UP TO 800∘C
Authors: WANG CHENGDONG , MING WEIWEI , CHEN MING 
Published: September 2017

Inconel 182 overlays is well known as a promising filler material, depositing on the surface of the critical components in nuclear power plants, light water reactor and petrochemical devices. As the deposited surface is usually non-uniform and irregular, the relative anti-impact cemented carbide tool is required. As the cemented carbide cannot withstand high temperature, the tungsten oxides are prone to form at elevated temperature, resulting in catastrophic tool failure. However, few literature reveals the tungsten oxides formation on the interface of the cemented carbide and Inconel 182 overlays at elevated temperature. Therefore, this study investigates the tungsten oxides formation on the interface of the cemented carbide (as well as its TiAlN or TiN coating for comparison) and the Inconel 182 overlays at elevated temperature up to 800∘C. The results show that the tungsten oxides WO[Formula: see text] ([Formula: see text]) are WO2, WO[Formula: see text], WO[Formula: see text] and WO3. They are formed by oxidation or reduction reactions at different combinations of the temperature and the atom percentage of oxygen.
Taking the Pulse of US College Campuses with Location-Based Anonymous Mobile Apps
Authors: Wu Yanqiu , Minkus Tehila , Ross Keith W. 
Published: September 2017

We deploy GPS hacking in conjunction with location-based mobile apps to passively survey users in targeted geographical regions. Specifically, we investigate surveying students at different college campuses with Yik Yak, an anonymous mobile app that is popular on US college campuses. In addition to being campus centric, Yik Yak’s anonymity allows students to express themselves candidly without self-censorship.
We collect nearly 1.6 million Yik Yak messages (“yaks”) from a diverse set of 45 college campuses in the United States. We use natural language processing to determine the sentiment (positive, negative, or neutral) of all of the yaks. We employ supervised machine learning to predict the gender of the authors of the yaks and then analyze how sentiment differs among the two genders on college campuses. We also use supervised machine learning to classify all the yaks into nine topics and then investigate which topics are most popular throughout the US and how topic popularity varies on the different campuses. The results in this article provide significant insight into how campus culture and student’s thinking varies among US colleges and universities.