bluuebunny/crossref_metadata_2025_split huggingface dataset:
Teaching Gas Turbine Technology to Undergraduate Students in Sweden
Authors: Aslanidou Ioanna , Zaccaria Valentina , Pontika Evangelia , Zimmerman Nathan , Kalfas Anestis I. , Kyprianidis Konstantinos G. 
Published: August 2018

This paper addresses the teaching of gas turbine technology in a third-year undergraduate course in Sweden and the challenges encountered. The improvements noted in the reaction of the students and the achievement of the learning outcomes is discussed. The course, aimed at students with a broad academic education on energy, is focused on gas turbines, covering topics from cycle studies and performance calculations to detailed design of turbomachinery components. It also includes economic aspects during the operation of heat and power generation systems and addresses combined cycles as well as hybrid energy systems with fuel cells.
The course structure comprises lectures from academics and industrial experts, study visits, and a comprehensive assignment. With the inclusion of all of these aspects in the course, the students find it rewarding despite the significant challenges encountered. An important contribution to the education of the students is giving them the chance, stimulation, and support to complete an assignment on gas turbine design. Particular attention is given on striking a balance between helping them find the solution to the design problem and encouraging them to think on their own.
Feedback received from the students highlighted some of the challenges and has given directions for improvements in the structure of the course, particularly with regards to the course assignment. This year, an application developed for a mobile phone in the Aristotle University of Thessaloniki for the calculation of engine performance will be introduced in the course. The app will have a supporting role during discussions and presentations in the classroom and help the students better understand gas turbine operation. This is also expected to reduce the workload of the students for the assignment and spike their interest.
Additive Manufacturing of Honeycombs Seal Strips
Authors: Geisen Ole , Kersting Lisa , Masseling Lukas , Bogner Jan Pascal , Schleifenbaum Johannes Henrich 
Published: August 2018

Laser-Powder Bed Fusion (L-PBF) is an additive manufacturing technique used to melt metal material into solid three-dimensional parts. While offering a high degree of design freedom, L-PBF still has technical restrictions, like the achievable surface roughness, resolution and the need for support structures in overhanging areas. [1]
Currently, L-PBF is used mainly to produce small batches of parts and prototypes. [2] In order to fully industrialize the technology, the research campus in Aachen is investigating possible future applications in turbomachinery while developing the corresponding processes with industry partners.
Sealing systems, like honeycomb seal strips in gas turbines often require time-consuming joining and assembly operations that can be avoided by building up the structure monolithically using L-PBF.
The following process development study proves the feasibility of manufacturing honeycombs with L-PBF using the Nickel-based super-alloy Inconel 718 (IN718) on an EOS M290 machine. Here, we have evaluated the economic aspects of different build orientations of the seal strips. Afterwards, we conducted a systematic parameter study with continuous and pulsed wave laser emission and investigated the resulting wall thicknesses. A reduction in wall thickness of about 30% can be observed when a modulated laser is used.
Multiphase CFD Modeling of External Oil Flow From a Journal Bearing
Authors: Berthold Martin , Morvan Hervé , Jefferson-Loveday Richard , Rothwell Benjamin C. , Young Colin 
Published: August 2018

High loads and bearing life requirements make journal bearings a potential choice for use in high power, epicyclic gearboxes in jet engines. Particularly in a planetary configuration the kinematic conditions are complex. With the planet gears rotating about their own axis and orbiting around the sun gear, centrifugal forces generated by both motions interact with each other and affect the external flow behavior of the oil exiting the journal bearing.
Computational Fluid Dynamics (CFD) simulations using the Volume of Fluid (VoF) method are carried out in ANSYS Fluent [1] to numerically model the two-phase flow behavior of the oil exiting the bearing and merging into the air surrounding the bearing.
This paper presents an investigation of two numerical schemes that are available in ANSYS Fluent to track or capture the air-oil phase interface: the geometric reconstruction scheme and the compressive scheme. Both numerical schemes are used to model the oil outflow behavior in the most simplistic approximation of a journal bearing: a representation, rotating about its own axis, with a circumferentially constant, i.e. concentric, lubricating gap. Based on these simplifications, a three dimensional (3D) CFD sector model with rotationally periodic boundaries is considered.
A comparison of the geometric reconstruction scheme and the compressive scheme is presented with regards to the accuracy of the phase interface reconstruction and the time required to reach steady state flow field conditions. The CFD predictions are validated against existing literature data with respect to the flow regime, the direction of the predicted oil flow path and the oil film thickness. Based on the findings and considerations of industrial requirements, a recommendation is made for the most suitable scheme to be used.
With a robust and partially validated CFD model in place, the model fidelity can be enhanced to include journal bearing eccentricity. Due to the convergent-divergent gap and the resultant pressure field within the lubricating oil film, the outflow behavior can be expected to be very different compared to that of a concentric journal bearing. Naturally, the inlet boundary conditions for the oil emerging from the journal bearing into the external environment must be consistent with the outlet conditions from the bearing. The second part of this paper therefore focuses on providing a method to generate appropriate inlet boundary conditions for external oil flow from an eccentric journal bearing.
Meander-Like Shape Optimization of the Stator-Rotor Platform Cavity
Authors: Juangphanich Paht , Paniagua Guillermo 
Published: August 2018

Recent progress in additive manufacturing has enabled opportunities to explore novel stator rim geometries which can be implemented to improve cooling strategies in turbomachinery. This paper presents a simplified stationary geometry optimization strategy to produce enhanced stator-rotor cavity sealing and highlights main driving mechanisms.
The stator and rotor rims were designed using a design strategy based on inspiration from the meandering of rivers. A minimum thickness of 2mm was maintained throughout the cavity to ensure a practical implementation. The computational domain comprised of the stator outlet, hub disk leakage cavity, and rotor platform was meshed using NUMECA Int. package, Hexpress. The numerical analysis required 3D Unsteady Reynolds Average Navier-Stokes to replicate vorticial structures using Ansys Fluent. The operating conditions were representative of engine-like conditions, exploring a wide range of massflow ratios from 1 to 3%. The optimization yielded designs that provide 30% reduction in rear platform temperature while minimizing coolant massflow. The applicability of the design was compared against 3D sector in both stationary and in rotation.
Dermatophagoides farinae allergen encapsule for oral immunotherapy with HDM allergic rhinitis
Authors: Zhang Han-zhong , Xie Wei , Wang Ying , Chen Jian , Wen Ting-huan 
Published: August 2018

It is well known that the house dust mites (HDMs) are the most common and potent inhalant allergens world-wide and the allergen immunotherapy (AIT) can efficaciously and safely ameliorate the allergic symptoms. Different formulations and routes of HDMs AIT have been achieved symptomatic improvement with mite allergic rhinitis (AR) and/or asthma. The object of the present article is to observe the efficacy and safety of oral immunotherapy (OIT) by enteric-coated capsules (EC) of Dermatophagoides farinae allergen (Df) with mite AR. A year of single blind placebo trial was applied. A total of 54 AR patients aged 25.8 in average with/without asthma and skin prick test (SPT) positive in HDMs were selected into either active or placebo groups. The OIT started with 5 days of dose rush induction, succeeded by a maintenance dose for 12 months. The efficacy of the treatment was assessed by symptomatic evaluation and laboratory in vivo and in vitro parameters of pre-immunotherapy (pre-IT) and post-immunotherapy (post-IT) statistically. The patients each received a total accumulative dose of 16 715BU Df protein nitrogen, and 87.5% (21/24) subjects achieved symptomatic improvement. The post-IT symptom scores decreased (t=11.07, P<0.001); visual analog scale (VAS) decreased (t=10.68, P<0.001); number of patients required symptom-medication decreased from 23/24 to 3/24 cases (c2=33.57, P<0.001); SPT wheal sizes of both Df and Dp significantly reduced (Df t=2.64, P=0.015 and Dp t=6.01, P<0.001); nasal provocation test (NPT) with the antigen tolerance elevated more than 3 times (c2=9.65, P=0.008). The only unchanged parameter was the tIgE levels (P=0.07). The parameters of placebo group were changed but not significant statistically or negligible. There were no local or general adverse reactions in both groups happened in the one year course of OIT. It is concluded that the newly designed formulation and route of clinical administration by Df EC OIT with AR were comparable to that of Df sublingual IT. The new formulation is more convenient and promising approach to treat AR.
The spatial footprint of injection wells in a global compilation of induced earthquake sequences
Authors: Goebel Thomas H. W. , Brodsky Emily E. 
Published: August 2018

Seismic limits for hard and soft rock
Induced earthquakes from oil, gas, and geothermal energy exploration projects can damage infrastructure and concern the public. However, it remains unclear how far away from an injection site an earthquake can still be triggered. Goebel and Brodsky looked at 18 different earthquake-producing injection sites around the world to address this issue. Injecting fluid into softer layers increased the range for seismic hazard, whereas harder basement rock better confined the fluid. These findings should be considered when regulating and managing projects with the potential to induce seismicity.

Science
, this issue p.
899
Exercise performance after salbutamol inhalation in non-asthmatic, non-athlete individuals: a randomised, controlled, cross-over trial
Authors: Eckerström Filip , Rex Christian Emil , Maagaard Marie , Rubak Sune , Hjortdal Vibeke Elisabeth , Heiberg Johan 
Published: August 2018

BackgroundAsthma is a frequent diagnosis in competitive sports, and inhaled β2-agonists are commonly used by athletes. Although inhaled β2-agonists do not seem to improve performance in athletes, it has remained uncertain whether they can increase exercise performance in non-athletes.ObjectiveTo investigate the effect of inhaled β2-agonists on exercise performance in healthy non-athlete individuals.MethodsIn a double-blinded, placebo-controlled, cross-over trial, healthy, non-asthmatic, non-athlete individuals were randomised to inhalation of either 900 µg of salbutamol or placebo. Cardiopulmonary exercise testing, dynamic spirometry and impulse oscillometry were performed. The primary outcome was the effect from salbutamol on peak oxygen uptake, whereas secondary outcomes were breathing reserve and ventilation efficiency, and workload, heart rate, breath rate and minute ventilation at peak exercise under influence of salbutamol.ResultsA total of 36 healthy subjects with a mean age of 26±5 years were included. Salbutamol had no effect on peak oxygen uptake compared with placebo, 46.8±1.3 mL/kg/min versus 46.6±1.2 mL/kg/min, p=0.64. Salbutamol had no effect on workload, p=0.20, heart rate, p=0.23, breath rate, p=0.10, or minute ventilation, p=0.26, at peak exercise compared with placebo. Salbutamol lowered oxygen uptake, p=0.04, and workload, p=0.04, at anaerobic threshold compared with placebo. Forced expiratory volume in 1 s, 116%±13% of predicted, and peak expiratory flow, 122%±16% of predicted, increased after inhalation of salbutamol compared with placebo; 109%±13% and 117%±17%, respectively, p<0.01. Breathing reserve was found to be higher, 22%±2%, after salbutamol inhalation than after placebo, 16%±2%, p<0.01.ConclusionInhaled salbutamol did not improve peak oxygen uptake in healthy, non-asthmatic, non-athlete individuals compared with placebo.Trial registration numberNCT02914652.
Multitrait genome association analysis identifies new susceptibility genes for human anthropometric variation in the GCAT cohort
Authors: Galván-Femenía Iván , Obón-Santacana Mireia , Piñeyro David , Guindo-Martinez Marta , Duran Xavier , Carreras Anna , Pluvinet Raquel , Velasco Juan , Ramos Laia , Aussó Susanna , Mercader J M , Puig Lluis , Perucho Manuel , Torrents David , Moreno Victor , Sumoy Lauro , de Cid Rafael 
Published: August 2018

BackgroundHeritability estimates have revealed an important contribution of SNP variants for most common traits; however, SNP analysis by single-trait genome-wide association studies (GWAS) has failed to uncover their impact. In this study, we applied a multitrait GWAS approach to discover additional factor of the missing heritability of human anthropometric variation.MethodsWe analysed 205 traits, including diseases identified at baseline in the GCAT cohort (Genomes For Life- Cohort study of the Genomes of Catalonia) (n=4988), a Mediterranean adult population-based cohort study from the south of Europe. We estimated SNP heritability contribution and single-trait GWAS for all traits from 15 million SNP variants. Then, we applied a multitrait-related approach to study genome-wide association to anthropometric measures in a two-stage meta-analysis with the UK Biobank cohort (n=336 107).ResultsHeritability estimates (eg, skin colour, alcohol consumption, smoking habit, body mass index, educational level or height) revealed an important contribution of SNP variants, ranging from 18% to 77%. Single-trait analysis identified 1785 SNPs with genome-wide significance threshold. From these, several previously reported single-trait hits were confirmed in our sample withLINC01432(p=1.9×10−9) variants associated with male baldness,LDLRvariants with hyperlipidaemia (ICD-9:272) (p=9.4×10−10) and variants inIRF4(p=2.8×10−57), SLC45A2(p=2.2×10−130), HERC2(p=2.8×10−176), OCA2(p=2.4×10−121) andMC1R(p=7.7×10−22) associated with hair, eye and skin colour, freckling, tanning capacity and sun burning sensitivity and the Fitzpatrick phototype score, all highly correlated cross-phenotypes. Multitrait meta-analysis of anthropometric variation validated 27 loci in a two-stage meta-analysis with a large British ancestry cohort, six of which are newly reported here (p value threshold <5×10−9) atZRANB2-AS2,PIK3R1,EPHA7,MAD1L1,CACUL1andMAP3K9.ConclusionConsidering multiple-related genetic phenotypes improve associated genome signal detection. These results indicate the potential value of data-driven multivariate phenotyping for genetic studies in large population-based cohorts to contribute to knowledge of complex traits.
First-principles calculations of electronic structures and ferromagnetism of Fe3Si(001)//MgO(001) films
Authors: Xie Jing , Xie Quan 
Published: August 2018

The first-principles calculations based on density functional theory (DFT) were carried out in investigating electronic structures and ferromagnetism of Fe3Si films epitaxial on MgO(001). Firstly, the various geometric structures of Fe3Si(001)//MgO(001) constructed near lattice constant c = 3.995 Å were optimized to gain the most steady equilibrium state at c = 3.980 Å. Then, the calculated cohesive energy and negative heat of formation indicate that Fe3Si(001)//MgO(001) formed in this manner obtain high structural stability. The calculated results of spin-polarized energy band structures and density of states show that Fe3Si(001)//MgO(001) exhibit the metallic feature whose bonding orbitals are constituted by covalent bond and metallic bond. Two peaks located in both the sides of the Fermi level and the total density of states (TDOS) in this energy range are all due to the Fe 3d states, which implies that the pseudo energy gap exists in the Fermi level and covalent electron orbit hybridization takes place. Ferromagnetism of Fe3Si(001)//MgO(001) are determined by the 3d states of Fe atoms. There are two occupied sites for Fe atoms with different local magnetic moments, which is 1.34 [Formula: see text]/atom for Fe[A, C] atoms and a value of 2.68 [Formula: see text]/atom for Fe[B] atoms, likewise indicating Fe3Si films epitaxial on MgO(001) are ferromagnetic.
Subcubic Equivalences Between Path, Matrix, and Triangle Problems
Authors: Williams Virginia Vassilevska , Williams R. Ryan 
Published: August 2018

We say an algorithm on
n
×
n
matrices with integer entries in [−
M
,
M
] (or
n
-node graphs with edge weights from [−
M
,
M
]) is
truly subcubic
if it runs in
O
(
n
3 − δ
ċ poly(log
M
)) time for some δ > 0. We define a notion of
subcubic reducibility
and show that many important problems on graphs and matrices solvable in
O
(
n
3
) time are
equivalent
under subcubic reductions. Namely, the following weighted problems either
all
have truly subcubic algorithms, or none of them do:

•The all-pairs shortest paths problem on weighted digraphs (APSP).
•Detecting if a weighted graph has a triangle of negative total edge weight.

•Listing up to
n
2.99
negative triangles in an edge-weighted graph.

•Finding a minimum weight cycle in a graph of non-negative edge weights.
•The replacement paths problem on weighted digraphs.
•Finding the second shortest simple path between two nodes in a weighted digraph.
•Checking whether a given matrix defines a metric.
•Verifying the correctness of a matrix product over the (min, +)-semiring.
•Finding a maximum subarray in a given matrix.

Therefore, if APSP cannot be solved in
n
3−ε
time for any ε > 0, then many other problems also need essentially cubic time. In fact, we show generic equivalences between matrix products over a large class of algebraic structures used in optimization, verifying a matrix product over the same structure, and corresponding triangle detection problems over the structure. These equivalences simplify prior work on subcubic algorithms for all-pairs path problems, since it now suffices to give appropriate subcubic triangle detection algorithms.

Other consequences of our work are new combinatorial approaches to Boolean matrix multiplication over the (OR,AND)-semiring (abbreviated as BMM). We show that practical advances in triangle detection would imply practical BMM algorithms, among other results. Building on our techniques, we give two improved BMM algorithms: a derandomization of the combinatorial BMM algorithm of Bansal and Williams (FOCS’09), and an improved quantum algorithm for BMM.
A Critical Discussion of Daniel A. Bell’s Political Meritocracy
Authors: Huang Yushun , Henderson Kathryn 
Published: August 2018

Abstract“Meritocracy” is among the political phenomena and political orientations found in modern Western democratic systems. Daniel A. Bell, however, imposes it on ancient Confucianism and contemporary China and refers to it in Chinese using loaded terms such asxianneng zhengzhi賢能政治 andshangxian zhi尚賢制. Bell’s “political meritocracy” not only consists of an anti-democratic political program but also is full of logical contradictions: at times, it is the antithesis of democracy, and, at other times, it is a supplement to democracy; sometimes it resolutely rejects democracy, and sometimes it desperately needs democratic mechanisms as the ultimate guarantee of its legitimacy. Bell’s criticism of democracy consists of untenable platitudes, and his defense of “political meritocracy” comprises a series of specious arguments. Ultimately, the main issue with “political meritocracy” is its blatant negation of popular sovereignty as well as the fact that it inherently represents a road leading directly to totalitarianism.
Pre-Qin Daoist Reflections on the Xianneng
Authors: Cao Feng , Weber Caterina 
Published: August 2018

AbstractIn the pre-Qin era, thexianneng賢能 [those of virtue and talent] were a commonly discussed topic, on which every school of thought had its own views. Daoist discussions on thexiannengsometimes reflected strong aversion and rejection, yet at other times gave them abundant praise and approval. Because of uncertainty on the universality of moral principles, on the limitations of one’s individual ability, and on the effectiveness of political actions, views in theLaozi老子 and theZhuangzi莊子 on thexiannengsaving society were skeptical in nature, sometimes even taking a mocking tone. Scholars of the Huang-Lao tradition had realized the limitations of individual ability and hoped that the greatest level of political benefit could be attained. Consequently, under the premise of safeguarding monarchical authority, fully displaying the skills and talents of all kinds of sages (imperial teachers and virtuous officials) through the practice ofwuwei無為 [inaction], and the highest leaders’ respect for virtue became the main direction in the Huang-Lao understanding of thexianneng. This tendency has much in common with the Legalist school of thought.
Deep Eddies in the Gulf of Mexico Observed with Floats
Authors: Furey Heather , Bower Amy , Perez-Brunius Paula , Hamilton Peter , Leben Robert 
Published: August 2018

AbstractA new set of deep float trajectory data collected in the Gulf of Mexico from 2011 to 2015 at 1500- and 2500-m depths is analyzed to describe mesoscale processes, with particular attention paid to the western Gulf. Wavelet analysis is used to identify coherent eddies in the float trajectories, leading to a census of the basinwide coherent eddy population and statistics of the eddies’ kinematic properties. The eddy census reveals a new formation region for anticyclones off the Campeche Escarpment, located northwest of the Yucatan Peninsula. These eddies appear to form locally, with no apparent direct connection to the upper layer. Once formed, the eddies drift westward along the northern edge of the Sigsbee Abyssal Gyre, located in the southwestern Gulf of Mexico over the abyssal plain. The formation mechanism and upstream sources for the Campeche Escarpment eddies are explored: the observational data suggest that eddy formation may be linked to the collision of a Loop Current eddy with the western boundary of the Gulf. Specifically, the disintegration of a deep dipole traveling under the Loop Current eddy Kraken, caused by the interaction with the northwestern continental slope, may lead to the acceleration of the abyssal gyre and the boundary current in the Bay of Campeche region.