bluuebunny/crossref_metadata_2025_split huggingface dataset:
Firm heterogeneity, market choice and productivity: Evidence from foreign‐owned enterprises in China
Authors: Yang Chih‐Hai , Tsou Meng‐Wen 
Published: August 2018

AbstractThis study examines the effects of firm heterogeneity on foreign‐owned enterprises’ (FOEs) choices regarding serving the local market, undertaking assembly exports or undertaking ordinary exports. It also investigates the effects of serving these markets on productivity. Using a detailed firm–transaction level matched data set of FOEs in China covering 2000–07, the first‐stage estimation of propensity score matching (PSM) method reveals that less productive FOEs tend to undertake assembly exports, and this effect is particularly relevant to those located in inland regions. By contrast, more productive FOEs are likely to serve domestic markets or undertake ordinary exports. Other firm characteristics also exhibit diverse influences on market choices. Export‐oriented FOEs, particularly those undertaking assembly exports, experience lower productivity growth than that of local market‐oriented FOEs. This suggests that the effects of local market competition do result in substantial enhancement of the productivity of FOEs in China. This pattern is mainly exhibited by FOEs in inland regions, whereas FOEs undertaking ordinary exports in coastal regions might have somewhat higher total factor productivity (TFP) growth than their local market‐oriented counterparts. Among export‐oriented FOEs, exporting more product value—whether assembly or ordinary exports—has a positive influence on productivity.
Parallel trade with an endogenous market structure
Authors: Shih Pei‐Cyuan , Hwang Hong , Peng Cheng‐Hau 
Published: August 2018

AbstractThis paper sets up a two‐country model in which there is one domestic manufacturer authorising its product to a distributor in the foreign country. The distributor can sell the product not only to its own market (i.e., the foreign market) but also back to the domestic market. The latter is called parallel trade (PT). The paper investigates the effects of PT on the profits of the manufacturer and social welfare if the domestic market structure is endogenously determined. It is found that PT should be encouraged rather than banned as it increases not only the profits of the manufacturer but also the welfare of both the domestic and the foreign countries.
The effects of social networks on the flow of international students
Authors: Stuen Eric T. , Ramirez Stefanie 
Published: August 2018

AbstractInternational study provides many benefits to the countries that host students, to the students’ home countries and to the students themselves. We extend the empirical knowledge regarding flows of international students, using a panel of data that spans 17 years, 26 host countries and 85 countries of origin. We examine the hypothesis that social networks are an important factor motivating study abroad by including lagged variables of the levels and shares of enrolment in the analysis. The analysis shows that they are significant factors: a 1% rise in a host country's share of an origin country's international student “diaspora” is associated with a 0.09%–0.12% rise in the number of students studying in that host from that origin, 5 years later. This is consistent with the literature on the economics of immigration, which finds social networks to be important, and transitory, in inducing immigration. These effects are found in models that control for other factors as well: earnings differentials, quality of higher education system, distance, common language and colonial relationship. The results suggest that one‐off policies to better recruit or attract international students will have ongoing benefits, in terms of follow‐on recruitment of further students by the initial students.
The future impact of Trans‐Pacific Partnership’s rule‐making achievements: The case study of e‐commerce
Authors: Hamanaka Shintaro 
Published: August 2018

AbstractWhile policymakers and scholars often emphasise the significance of the rule‐making aspect when they discuss the benefits of negotiating free trade agreements (FTAs), we know little about the ways in which rules are actually made. We need impartial assessment of the status of rule‐making to draw any concrete policy implications. Moreover, “how international economic rules develop” in terms of enforceability has been a neglected but important research question for students of international economics and laws. International economic rules evolve through a series of FTAs that are signed by a different set of countries. By using the case study of e‐commerce chapters, this paper will specifically examine: (1) how earlier FTAs paved the way to the Trans‐Pacific Partnership (TPP) e‐commerce negotiations; (2) whether rule‐making achievements of TPP are substantial compared against earlier FTAs; and (3) whether rule‐making achievements of TPP, if any, are likely to have some impact on post‐TPP FTAs.
REDEEMING A CRUCIFORM NATURE
Authors: Rolston Holmes 
Published: August 2018

AbstractChristopher Southgate recognizes that the natural world is both ambiguous, mixing goods and bads, and simultaneously dramatically creative, such creativity resulting from just this ambiguous challenge of environmental conductance and resistance. Life is lived in green pastures and in the valley of the shadow of death. Perhaps this is the only way God could have created the values found on Earth, by means of such disvalues, as a Darwinian natural selection account suggests. Generating Earth's biodiversity requires struggle, success, and failure—and such an only way would constrain a powerful, loving God. But Southgate judges this too uncaring of suffering individuals, the products of evolution sacrificed to the systemic process. Perhaps God through Jesus redeems all the sacrificed individuals—pelicans in a pelican heaven—but redemption of all the bullfrogs and acorns becomes an incredible hope. Nature is a cruciform creation, where life persists in perpetual perishing. Life is forever conserved, regenerated, redeemed.
TEACHING SCIENCE AND RELIGION IN THE TWENTY‐FIRST CENTURY: THE MANY PEDAGOGICAL ROLES OF CHRISTOPHER SOUTHGATE
Authors: Corbally Christopher , Rappaport Margaret Boone 
Published: August 2018

AbstractWith the goal of understanding how Christopher Southgate communicates his in‐depth knowledge of both science and theology, we investigated the many roles he assumes as a teacher. We settled upon wide‐ranging topics that all intertwine: (1) his roles as author and coordinating editor of a premier textbook on science and theology, now in its third edition; (2) his oral presentations worldwide, including plenaries, workshops, and short courses; and (3) the team teaching approach itself, which is often needed by others because the knowledge of science and theology do not always reside in the same person. Southgate provides, whenever possible, teaching contexts that involve students in experiential learning, where they actively participate with other students. We conclude that Southgate's ultimate goal is to teach students how to reconcile science and theology in their values and beliefs, so that they can take advantage of both forms of rational thinking in their own personal and professional lives. The co‐authors consider several examples of models that have been successfully used by people in various fields to integrate science and religion.
Design and Emulation of a Turbocharged Bio-Fuelled SOFC Plant
Authors: Ferrari Mario L. , De Campo Marco , Magistri Loredana 
Published: August 2018

This paper presents a steady-state model of an innovative turbocharged solid oxide fuel cell system fed by biofuel. The aim of this plant layout is the development of a reduced-cost solution, which involves the pressurization carried out with a mass production machine such as a turbocharger (instead of a microturbine). The turbocharger pressurizes the solid oxide fuel cell to increase the performance.
Following the experimental results to choose the suitable machine and for validating the turbocharger model, this tool was implemented to model the whole plant. It was used to calculate the operational conditions and to define the coupling aspects between the turbocharger, the recuperator and the solid oxide fuel cell system (comprising a fuel cell stack, an air preheater, a reformer, an off-gas burner and an anodic ejector).
The model permitted the component characterization and supported the design of an emulator test rig based on the coupling of a turbocharger and a pressure vessel. This facility was designed to conduct the experimental tests at system level on the matching between the machine and the fuel cell, especially for the dynamic and the control system aspects. To emulate the fuel cell, the rig was based on a specially designed pressure vessel equipped with a burner and inert ceramic materials. Moreover, the facility was designed to produce the turbine inlet conditions in terms of mass flow, temperature, pressure and gas composition (similitude conditions can be evaluated).
The Inner Workings of Axial Casing Grooves in a One and a Half Stage Axial Compressor With a Large Rotor Tip Gap: Changes in Stall Margin and Efficiency
Authors: Hah Chunill 
Published: August 2018

Effects of axial casing grooves (ACGs) on the stall margin and efficiency of a one and a half stage low-speed axial compressor with a large rotor tip gap are investigated in detail. The primary focus of the current paper is to identify the flow mechanisms behind the changes in stall margin and on the efficiency of the compressor stage with a large rotor tip gap. Semicircular axial grooves installed in the rotor’s leading edge area are investigated. A large eddy simulation (LES) is applied to calculate the unsteady flow field in a compressor stage with ACGs. The calculated flow fields are first validated with previously reported flow visualizations and stereo PIV (SPIV) measurements. An in-depth examination of the calculated flow field indicates that the primary mechanism of the ACG is the prevention of full tip leakage vortex (TLV) formation when the rotor blade passes under the axial grooves periodically. The TLV is formed when the incoming main flow boundary layer collides with the tip clearance flow boundary layer coming from the opposite direction near the casing and rolls up around the rotor tip vortex. When the rotor passes directly under the axial groove, the tip clearance flow boundary layer on the casing moves into the ACGs and no roll-up of the incoming main flow boundary layer can occur. Consequently, the full TLV is not formed periodically as the rotor passes under the open casing of the axial grooves. Axial grooves prevent the formation of the full TLV. This periodic prevention of the full TLV generation is the main mechanism explaining how the ACGs extend the compressor stall margin by reducing the total blockage near the rotor tip area. Flows coming out from the front of the grooves affect the overall performance as it increases the flow incidence near the leading edge and the blade loading with the current ACGs. The primary flow mechanism of the ACGs is periodic prevention of the full TLV formation.
Lower efficiency and reduced pressure rise at higher flow rates for the current casing groove configuration are due to additional mixing between the main passage flow and the flow from the grooves. At higher flow rates, blockage generation due to this additional mixing is larger than any removal of the flow blockage by the grooves. Furthermore, stronger double-leakage tip clearance flow is generated with this additional mixing with the ACGs at a higher flow rate than that of the smooth wall.
Influence of a Non-Axisymmetric Endwall on the Flow Field in a Turbine Passage: High-Resolution LDV
Authors: Schmid Jonas , Schulz Achmed , Bauer Hans-Jörg 
Published: August 2018

The present paper focuses on the influence of a non-axisymmetric endwall on the flow field in a turbine passage. Therefore, laser Doppler velocimetry (LDV) is applied to both a non-axisymmetric endwall and a flat endwall as reference. Time mean values and fluctuating components of the velocity field are evaluated.
Three-component LDV with up to 38000 valid coincident events per second is carried out up- and downstream of a linear cascade with high resolution, especially in the near-wall region of the suction surface, where secondary vortices are expected. The three velocity components recorded by the LDV are transformed into the orthogonal coordinate system of the turbine cascade, and several flow quantities, like turbulence parameters and parameters describing the secondary regime, are assessed. By comparing the data for the non-axisymmetric endwall and the flat endwall, the influence of the contouring on the secondary flow field is shown. To substantiate the measurements and gain a deeper insight, the data are compared to previous surface oil flow visualizations and specific results of former thermal studies.
Influence of Leakage Flows on Hot Gas Ingress
Authors: Patinios Marios , Ong Irvin L. , Scobie James A. , Lock Gary D. , Sangan Carl M. 
Published: August 2018

One of the most important problems facing gas turbine designers today is the ingestion of hot mainstream gases into the wheel-space between the turbine disc (rotor) and its adjacent casing (stator). A rim seal is fitted at the periphery and a superposed sealant flow — typically fed through the bore of the stator — is used to prevent ingress. The majority of research studies investigating ingress do so in the absence of any leakage paths that exist throughout the engine’s architecture. These inevitable pathways are found between the mating interfaces of adjacent pieces of hardware. In an environment where the turbine is subjected to aggressive thermal and centrifugal loading these interface gaps can be difficult to predict and the resulting leakage flows which pass through them even harder to account for.
This paper describes experimental results from a research facility which experimentally models hot gas ingestion into the wheel-space of an axial turbine stage. The facility was specifically designed to incorporate leakage flows through the stator disc; leakage flows were introduced axially through the stator shroud or directly underneath the vane carrier ring. Measurements of CO2 gas concentration, static pressure and total pressure were used to examine the wheel-space flow structure with and without ingress from the mainstream gas-path. Data is presented for a simple axial-clearance rim-seal. The results support two distinct flow-structures, which are shown to be dependent on the mass-flow ratio of bore and leakage flows. Once the leakage flow was increased above a certain threshold, the flow structure is shown to transition from a classical Batchelor-type rotor-stator system to a vortex-dominated structure. The existence of a toroidal vortex immediately inboard of the outer rim-seal is shown to encourage ingestion.
Improvement in the Rapid Startup Performance for the Solar Steam Turbine
Authors: Wang Peng , Chen Gang , Li WenFu 
Published: August 2018

In the latest several years, concentrated solar plants (CSP) have been rapidly developed. Steam turbines employed in these plants are subjected to daily start up and continuous load variations. There is a general increase in demand for operation flexibility and rapid start up capability for solar steam turbines. Accordingly, how to decrease the low cyclic fatigue life consumption during the daily start up process is a hot researched topic at present, and this greatly depends on the transient thermal stress. A number of studies show that the startup schemes and the unit’s structural form decide the LCF life consumption directly.
In this paper, a 50MW double cylinder (HP and ILP Section) reheat solar steam turbine is studied, and it is operated continuously with inlet steam conditions of 540[°C], 140[bar], reheat steam conditions of 540[°C], 24[bar] and exhaust conditions of 41.5[°C], 0.08[bar]. A number of comparisons are made with the FEM numerical simulation, and some optimal designs which are applied to improve the rapid start up performance and decrease the LCF life consumption during the startup are presented.
An Efficient Transient Simulation Method for a Volume Dynamics Model
Authors: Kurosaki Masahiro , Sasamoto Minoru , Asaka Kentaro , Nakamura Keiko , Kakiuchi Daiki 
Published: August 2018

This paper presents an efficient numerical integration method for a volume dynamics model in gas turbine engine transient simulations. It is a modified implicit Euler method that allows a time increment that would not be stable with the explicit Euler method. The Jacobian matrix of a nonlinear engine model is evaluated along the steady state engine operation line and scheduled as a function of the corrected shaft speed in advance, eliminating the necessity of computing during the simulation.
The proposed method was applied to transient simulations of a compressor rig test model composed of a compressor, a nozzle with variable geometry and a volume placed between them. The eigenvalues of the simplified volume dynamics were analytically derived. It is shown that they are functions of the characteristic time of the volume defined by mass present in the volume divided by mass flow rate flowing into and out of the volume and dimensionless influence coefficients of nearby components.
Experimental Investigation of an Inverted Brayton Cycle for Exhaust Gas Energy Recovery
Authors: Kennedy Ian , Chen Zhihang , Ceen Bob , Jones Simon , Copeland Colin D. 
Published: August 2018

Exhaust gases from an internal combustion engine (ICE) contain approximately 30% of the total energy released from combustion of the fuel. In order to improve fuel economy and reduce emissions, there are a number of technologies available to recover some of the otherwise wasted energy. The inverted Brayton cycle (IBC) is one such technology.
The purpose of the study is to conduct a parametric experimental investigation of the IBC. Hot air from a turbocharger test facility is used. The system is sized to operate using the exhaust gases produced by a 2 litre turbocharged engine at motorway cruise conditions. A number of parameters are investigated that impact the performance of the system such as turbine inlet temperature, system pressure drop and compressor inlet temperature.
The results confirm that the output power is strongly affected by the turbine inlet temperature and system pressure drop. The study also highlights the packaging and performance advantages of using a 3D printed heat exchanger to reject the excess heat. Due to rotordynamic issues, the speed of the system was limited to 80,000 rpm rather than the target 120,000 rpm. However, the results show that the system can generate a specific work of up to 17 kJ/kg at 80,000 rpm. At full speed it is estimated that the system can develop approximately 47 kJ/kg, which represents a thermal efficiency of approximately 5%.
Design of a Variable Geometry Axial-Inflow Turbine Turbocharger Equipped With a Diffuser-Collector System
Authors: Pesyridis Apostolos , Cappiello Alessandro , Tuccillo Raffaele 
Published: August 2018

The fluid-dynamic design of a bespoke variable geometry axial inflow turbine, equipped with a diffuser-collector system for turbocharging applications, was numerically investigated with the purpose of replacing the radial flow turbine in a commercial turbocharger.
The paper aims to investigate the suitability of axial turbines for turbocharging applications in the automotive field. The turbine outflow is linked to a diffuser-collector system in order to obtain a kinetic energy recovery together with a correct flow direction to the discharge system.
Additionally, once completed the turbine design, the operating maps for three different stator positions were numerically obtained.
Finally, a turbocharger–engine matching model allowed comparison of the new axial and conventional radial flow turbine in terms of turbine power and efficiency, compressor pressure ratio, engine torque and BSFC.
Investigation of Flow-Induced Radial Force and its Influence on Rotor Dynamics for a Cryogenic Liquid Turbine Expander
Authors: Yuan Ningbo , Sun Jinju , Song Peng , Huo Changjiang , Sun Shan 
Published: August 2018

To improve the operating stability of a cryogenic liquid turbine expander, the influence of flow behavior on rotor radial force and critical speed is investigated numerically. At both design and off-design conditions, unsteady flow simulation is conducted in the entire expander environment where the physical model is constituted by a volute, nozzle, impeller and diffuser duct. The asymmetric flow characteristics are captured at both design and off-design conditions and they are responsible for the significant radial force on rotor. The radial component of flow-induced resultant force is calculated with direct integration approach and it is significant due to apparent asymmetric impeller flow. The influence of such radial component of flow-induced resultant force on the rotor critical speed is further investigated, where the flow-induced radial force is considered as an equivalent mass and superposed on the impeller mass integrity to obtain a resultant mass of impeller, which is used in the prediction of rotor critical speed.
To predict rotor critical speed, a finite element method is developed and incorporated into a FORTRAN code, and it is validated and then used to predict the rotor critical speed with and without consideration of the radial component of flow-induced resultant force respectively. The following is described: at both design condition and off-design conditions, the predicted critical speeds with consideration of flow-induced radial force are significantly below that without flow-induced radial force. The influence of impeller flow behavior on rotor dynamics of the turbine expander is not negligible.
Coupled Thermal-Structural-Fluid Numerical Analysis of Gas Lubricated Mechanical Seals
Authors: Luo Jingjing , Dohmen Hans Josef , Benra Friedrich-Karl 
Published: August 2018

With the increase of the operating pressure of gas compressors, the demand for a robust and reliable shaft end sealing solution, namely dry gas seal, has risen. The narrow sealing gap formed between the rotating and the stationary rings, about 2–5 micrometers wide, is subject to the hydrodynamic pressure on sealing surfaces and deflections on both rings due to mechanical forces and thermal loads. In order to estimate the seal performance in terms of film thicknesses, leakage flows and radial tapers, a numerical program which automatically couples the simulation of the pressure field in micro-scale based on the Reynolds equation for compressible fluids, the heat generation and transfer model between the fluid and solids as well as the structural and thermal distortion of both rings, has been developed by the authors to address the mechanical seal problem as a whole system. In this way, the interaction of all arising forces, mechanical deformations and thermal deviations is taken into account in the design process of the seals. The choked flow exit boundary is also taken into considerations for high pressure conditions.
The method to solve this interactive problem as a whole is discussed. The paper presents the numerical analysis carried out with various groove parameters, seal geometries and operating conditions. Results are compared and show a good agreement with actual experimental data. Design parameters which have strong influences on the seal performance are as well discussed.