bluuebunny/crossref_metadata_2025 huggingface dataset:
Arabidopsis ACYL‐COA‐BINDING PROTEIN1 interacts with STEROL C4‐METHYL OXIDASE1‐2 to modulate gene expression of homeodomain‐leucine zipper IV transcription factors
Authors: Lung Shiu‐Cheung , Liao Pan , Yeung Edward C. , Hsiao An‐Shan , Xue Yan , Chye Mee‐Len
Published: December 2017

Fatty acids (FAs) and sterols constitute building blocks of eukaryotic membranes and lipid signals. Co‐regulation of FA and sterol synthesis is mediated by sterol regulatory element‐binding proteins in animals but remains elusive in plants. We reported recently that Arabidopsis ACYL‐COA‐BINDING PROTEIN1 (ACBP1) modulates sterol synthesis via protein–protein interaction with STEROL C4‐METHYL OXIDASE1‐1 (SMO1‐1).

Herein, ACBP1 was demonstrated to co‐express and interact with SMO1‐2 by yeast two‐hybrid, co‐localization, pull‐down, co‐immunoprecipitation and β‐glucuronidase assays. SMO1‐2 silenced in acbp1 was used in phenotyping, GC‐MS and expression profiling.

ACBP1 co‐expressed with SMO1‐2 in embryo sacs, pollen and trichomes, corroborating with cooperative tissue‐specific functions unseen with SMO1‐1. SMO1‐2 silencing in acbp1 impaired seed development, male and female gamete transmission, and pollen function. Genes encoding homeodomain‐leucine zipper IV transcription factors (HDG5, HDG10, HDG11 and GLABRA2), which potentially bind phospholipids/sterols, were transcribed aberrantly. GLABRA2 targets (MYB23, MUM4 and PLDα1) were misregulated, causing glabra2‐resembling trichome, seed coat mucilage and oil‐accumulating phenotypes.

Together with altered sterol and FA compositions upon ACBP1 mutation and/or SMO1‐2 silencing, ACBP1–SMO1 interaction appears to mediate homeostatic co‐regulation of FAs and sterols, which serve as lipid modulators for gene expression of homeodomain‐leucine zipper IV transcription factors.
Proposal for the development of biologics in pediatric rheumatology
Authors: Mori Masaaki , Nakagawa Masao , Tsuchida Nao , Kawada Kou , Sato Junko , Sakiyama Michiyo , Hirano Shinya , Sato Katsuaki , Nakamura Hidefumi
Published: December 2017

In order to assess the development, approval and early introduction into clinical practice of biologics in the pediatric field, we herein describe the current status of the development to approval of biologics as anti‐rheumatic agents for children in Japan, discuss the present problems and provide a proposal for the future. It has become apparent that the duration of the review period required for the preparation of clinical trials and Pharmaceuticals and Medical Devices Agency approval is clearly reduced compared with the past. Thus, it was speculated that a rate‐limiting step in the process from development to approval was the duration of clinical trials from start to end. Hence, we focused on the following key words with regard to promotion of the development of biologics and their early practical use: “registry”, “centralization”, and “global cooperation”, all of which are related to the reduction of duration of a clinical trial. In conclusion, to reduce the duration of a clinical trial, it is essential to complete a world‐scale registry system by developing the registry system established by the Pediatric Rheumatology Association of Japan. The next step is then to carefully plan to participate in the international network using the world‐scale registry system, and develop global cooperative trials in which we can ensure a sufficient number of entries from Japan.
Questionnaire survey on mumps vaccination for parents in Nara prefecture, Japan
Authors: Kitano Taito , Nishikawa Hiroki , Onaka Masayuki , Ishihara Mariko , Nishiyama Atsuko , Yoshida Sayaka
Published: December 2017

Background

Although the mumps vaccine has not been included in the national immunization program (NIP) in Japan, it has been shown that a two‐dose routine vaccine program would be highly cost‐effective. In this study, we carried outa questionnaire‐based study to investigate how many Japanese parents want the mumps vaccine to be included in the NIP with proper information.

Methods

The questionnaire was given to parents who visited the Pediatrics or neonatal intensive care unit of Nara Prefecture General Medical Center, Nara City, Japan, between 1 March 2017 and 31 August 2017. The questionnaire consisted of information about mumps and six questions, for example (i) do parents know that mumps can be prevented by vaccine; (ii) do they know that they need to pay for mumps vaccines; and (iii) do they hope that the government will resume routine mumps vaccination.

Results

In total, 1,224 parents answered the questionnaire. A total of 81% and 75.4% of parents knew that mumps can be prevented by vaccination and that mumps vaccine is not included in the NIP, respectively, before reading the information. After reading the information, 95.0% of parents thought that mumps vaccine should be included in the NIP. While 61.7% of parents answered that they would choose two‐dose vaccination without governmental financial support, 92.1% of them would choose two‐dose vaccination with governmental financial support (P < 0.0001).

Conclusion

Japanese parents want the mumps vaccine to be included in the NIP. Japan is able to start routine use of the mumps vaccine now.
Survey of rotavirus‐associated severe complications in Aichi Prefecture
Authors: Hattori Fumihiko , Kawamura Yoshiki , Kawada Jun‐ichi , Kojima Seiji , Natsume Jun , Ito Koichi , Saito Shinji , Kitagawa Yoshiro , Okumura Akihisa , Yoshikawa Tetsushi ,   the Aichi Pediatric Clinical Study Group
Published: December 2017

Background

Rotavirus can, rarely, cause severe complications such as encephalopathy/encephalitis, myocarditis, sudden death, urinary stone, and gastrointestinal (GI) bleeding; and the incidence of these severe complications remains unclear. Additionally, it has not been determined whether rotavirus (RV) vaccine could reduce cases of severe complications or not.

Methods

A two‐part questionnaire was designed to determine the number and clinical features of severe complications between 1 September 2008 and 31 August 2015, including the observation periods before and after RV vaccine introduction in Aichi Prefecture.

Results

Twenty‐four cases of encephalitis/encephalopathy, eight cases of sudden death, three cases of urinary tract stone, and three cases of GI bleeding were reported during the 2008/2009 season and the 2012/2013 seasons. Although five cases of encephalitis/encephalopathy were reported, no other cases of severe complications were reported during the 2013/2014 and 2014/2015 seasons. No age difference was noted according to type of complication. Although onset of encephalitis/encephalopathy and of sudden death was around day 2 of illness, that of urinary tract stone and GI bleeding was slightly later (day 6 and day 4). In addition to the eight sudden deaths, fatal outcome was also noted in four cases (13.8%) of encephalitis/encephalopathy, and in one case of GI bleeding.

Conclusion

According to the questionnaire survey in Aichi Prefecture, the incidence of the four severe RV‐associated complications appears to have declined as the vaccination rate has increased.
High‐grade transformation/dedifferentiation of an adenoid cystic carcinoma of the minor salivary gland to myoepithelial carcinoma
Authors: Tando So , Nagao Toshitaka , Kayano Kaori , Fushiki Shinji , Itoh Kyoko
Published: December 2017

High‐grade transformation (HGT)/dedifferentiation is an unusual phenomenon in salivary gland carcinomas. Here we report a case of adenoid cystic carcinoma (ACC) with HGT/dedifferentiation to myoepithelial carcinoma, occurring in the epipharynx of a 42‐year‐old woman. The surgically resected tumor was a pedunculated mass, 31 × 25 mm in size, which had two histologically distinct carcinomatous areas, including a high‐grade sarcomatoid area composed of pleomorphic spindle cells and an area consisting of low‐grade typical ACC. These two components gradually changed from the low‐grade to the high‐grade component. MIB‐1 index in the low‐grade and high‐grade component was 15% and 50%, respectively. An immunohistochemical profile of the high‐grade component showed immunoreactivity for α‐SMA, p63, calponin and focal S100, as well as for several cytokeratin markers, which were compatible with the features of myoepithelial carcinoma. In contrast, the immunohistochemical profile of the low‐grade component coincided with that of typical ACC. This HGT/dedifferentiation to myoepithelial carcinoma is extremely rare. The pathogenesis of HGT/dedifferentiation in salivary gland carcinomas still remains largely unknown, regardless of the presence or absence of myoepithelial differentiation. Further studies are required due to the more aggressive biological behavior and poorer prognosis associated with ACC with HGT/dedifferentiation, compared with conventional ACC.
Can Google Trends Improve Your Sales Forecast?
Authors: Boone Tonya , Ganeshan Ram , Hicks Robert L. , Sanders Nada R.
Published: December 2017

In this issue, Cui et al. ( 2018 ) show how the quantity and quality of user‐generated Facebook data can be used to enhance product forecasts. The intent of this note is to show how another type of user‐generated content—customer search data, specifically one obtained from Google Trends—can be used to reduce out‐of‐sample forecast errors. Based on our work with an online retailer, we bolster Cui et al. ( 2018 ) result by showing that adding customer search data to time series models improves out‐of‐sample forecast errors.
Biogeographic history of subterranean isopods from groundwater calcrete islands in Western Australia
Authors: Javidkar Mohammad , Cooper Steven J. B. , Humphreys William F. , King Rachael A. , Judd Simon , Austin Andrew D.
Published: December 2017

Groundwater calcretes in arid central Western Australia contain a diverse invertebrate groundwater fauna (stygofauna). Surveys have uncovered a diverse oniscidean isopod subterranean fauna above the water table (troglofauna), including species of a recently described genus Paraplatyarthrus. The aim of this study was to investigate the biogeographic history of Paraplatyarthrus and the timing of transitions from surface to subterranean habitats. Phylogenetic relationships among the isopod troglofauna from 11 groundwater calcretes along three palaeodrainage systems were assessed using one mitochondrial gene, cytochrome c oxidase subunit 1 (COI), and two nuclear markers, lysyl‐tRNA synthetase (LysRS) and 18S rRNA (18S) genes. Phylogenetic analyses revealed multiple sister lineage relationships between troglophile and troglobite lineages and evidence for divergent mtDNA lineages within species, providing a range of nodes for dating evolutionary transitions from surface to subterranean habitats. Relaxed molecular clock analyses provided evidence that evolutionary transitions from surface to subterranean environments took place between 13.3 and 1.75 million years ago, coinciding with the onset of aridification of Australia from the late Tertiary. In cases where groundwater calcretes contained multiple species, the taxa were not closely related phylogenetically, suggesting that these calcretes were independently colonised by multiple ancestral species. The study further confirmed the role of late/post‐Miocene aridification as a key driver of the evolution of subterranean invertebrates in the calcrete islands of Western Australia, supporting the climatic relict hypothesis. Troglobites most likely evolved from the troglophile ancestors that were capable of dispersal among, and active colonisation of, calcretes.
Evolutionary history of spiny‐tailed lizards (Agamidae: Uromastyx) from the Saharo‐Arabian region
Authors: Tamar Karin , Metallinou Margarita , Wilms Thomas , Schmitz Andreas , Crochet Pierre‐André , Geniez Philippe , Carranza Salvador
Published: December 2017

The subfamily Uromastycinae within the Agamidae is comprised of 18 species: three within the genus Saara and 15 within Uromastyx. Uromastyx is distributed in the desert areas of North Africa and across the Arabian Peninsula towards Iran. The systematics of this genus has been previously revised, although incomplete taxonomic sampling or weakly supported topologies resulted in inconclusive relationships. Biogeographic assessments of Uromastycinae mostly agree on the direction of dispersal from Asia to Africa, although the timeframe of the cladogenesis events has never been fully explored. In this study, we analysed 129 Uromastyx specimens from across the entire distribution range of the genus. We included all but one of the recognized taxa of the genus and sequenced them for three mitochondrial and three nuclear markers. This enabled us to obtain a comprehensive multilocus time‐calibrated phylogeny of the genus, using the concatenated data and species trees. We also applied coalescent‐based species delimitation methods, phylogenetic network analyses and model‐testing approaches to biogeographic inferences. Our results revealed Uromastyx as a monophyletic genus comprised of five groups and 14 independently evolving lineages, corresponding to the 14 currently recognized species sampled. The onset of Uromastyx diversification is estimated to have occurred in south‐west Asia during the Middle Miocene with a later radiation in North Africa. During its Saharo‐Arabian colonization, Uromastyx underwent multiple vicariance and dispersal events, hypothesized to be derived from tectonic movements and habitat fragmentation due to the active continental separation of Arabia from Africa and the expansion and contraction of arid areas in the region.
Study of the Concepts of Athletic Identity and Continuous Sport Self-Confidence in the Light of Various Variables
Authors: Şekeroğlu Mustafa Önder
Published: December 2017

This study was planned and conducted for the purpose of examining the relationship between the concepts of athletic identity and continuous sport self-confidence within the framework of various variables. The study group is comprised of 125 sportsmen of different branches, located at the Ankara Eryaman Olympics Preparation Centre. Along with a personal information form, the participants were subjected to the "Athletic Identity Scale" developed by Brewer and Cornelius (2001) in order to measure the athletic identity roles, as well as the "Continuous Sport Self-Confidence Scale," which is a sub-dimension of the measurement tool developed by Vealey (1986) in order to assess sport confidence. In this study, while no significant difference was found between the total points for continuous sport self-confidence according to gender, a significant difference was found between the athletic identity points. No statistically significant difference was found between the total points for continuous sport self-confidence and athletic identity according to their branches, number of national representation and their years of sport. In the meanwhile, it was found that 64% of the sportsmen in the research group were satisfied with their relations with their parents, while 52% were satisfied with their relations with their friends. It was found that 40% of the sportsmen were satisfied with how they used their spare time, and 48% were satisfied with their success in their studies.
The Effects of Ten Weekly Plyometric Training of Judokas on Anaerobic Power
Authors: Uzun Ahmet , Karakoc Onder
Published: December 2017

This study was conducted to determine the effects of ten weekly plyometric training on anaerobic power in judokas. 30 male judokas participated in the study and the subjects were divided into two groups as an experimental (15 male age = 21,40 ± 1,99) and control (15 male age = 21,53 ± 1,80) groups. Judo training programme was applied in both groups for 3 days / 90 minutes per week. Experimental and control group were made warm up exercises for 20 minutes. Both groups continued with the special preparatory period judo training program. After warm up exercises, experimental group judokas were made plyometric training consisting of 15 different movements for 20 minutes. Then they were allowed to continue the judo training. As the groups showed normal distribution, Paired Samples T-Test was applied for the significance between pre-test and post-test measurements of the groups. Independent Samples T-Test was used to analyze the difference between the test group and control group. The Independent Samples T-Test was used to analyze the difference between the experimental group and the control group. As a result of the plyometric training, when the pre-test and post-test differences of the physical measurement parameters for the experimental and control groups were compared, the mean values of back strength, anaerobic power and body fat percentage were found to be significant(p0.05).

As a result, it is seen that the regular plyometric exercises increase the performance of anaerobic power to judokas. It can be said that putting plyometric training besides judo training has a positive effect for performance.
Skeletal muscle microvascular and interstitial from rest to contractions
Authors: Hirai Daniel M. , Craig Jesse C. , Colburn Trenton D. , Eshima Hiroaki , Kano Yutaka , Sexton William L. , Musch Timothy I. , Poole David C.
Published: December 2017

Key points

Oxygen pressure gradients across the microvascular walls are essential for oxygen diffusion from blood to tissue cells. At any given flux, the magnitude of these transmural gradients is proportional to the local resistance.

The greatest resistance to oxygen transport into skeletal muscle is considered to reside in the short distance between red blood cells and myocytes. Although crucial to oxygen transport, little is known about transmural pressure gradients within skeletal muscle during contractions.

We evaluated oxygen pressures within both the skeletal muscle microvascular and interstitial spaces to determine transmural gradients during the rest–contraction transient in anaesthetized rats.

The significant transmural gradient observed at rest was sustained during submaximal muscle contractions.

Our findings support that the blood–myocyte interface provides substantial resistance to oxygen diffusion at rest and during contractions and suggest that modulations in microvascular haemodynamics and red blood cell distribution constitute primary mechanisms driving increased transmural oxygen flux with contractions.

Oxygen pressure () gradients across the blood–myocyte interface are required for diffusive O2 transport, thereby supporting oxidative metabolism. The greatest resistance to O2 flux into skeletal muscle is considered to reside between the erythrocyte surface and adjacent sarcolemma, although this has not been measured during contractions. We tested the hypothesis that O2 gradients between skeletal muscle microvascular () and interstitial () spaces would be present at rest and maintained or increased during contractions. and   were determined via phosphorescence quenching (Oxyphor probes G2 and G4, respectively) in the exposed rat spinotrapezius during the rest–contraction transient (1 Hz, 6 V; n = 8). was higher than in all instances from rest (34.9 ± 6.0 versus 15.7 ± 6.4) to contractions (28.4 ± 5.3 versus 10.6 ± 5.2 mmHg, respectively) such that the mean gradient throughout the transient was 16.9 ± 6.6 mmHg (P < 0.05 for all). No differences in the amplitude of fall with contractions were observed between the microvasculature and interstitium (10.9 ± 2.3 versus 9.0 ± 3.5 mmHg, respectively; P > 0.05). However, the speed of the fall during contractions was slower than that of (time constant: 12.8 ± 4.7 versus 9.0 ± 5.1 s, respectively; P < 0.05). Consistent with our hypothesis, a significant transmural gradient was sustained (but not increased) from rest to contractions. This supports that the blood–myocyte interface is the site of a substantial gradient driving O2 diffusion during metabolic transients. Based on Fick's law, elevated O2 flux with contractions must thus rely primarily on modulations in effective diffusing capacity (mainly erythrocyte haemodynamics and distribution) as the gradient is not increased.
Turbomachinery Active Subspace Performance Maps
Authors: Seshadri Pranay , Shahpar Shahrokh , Constantine Paul , Parks Geoffrey , Adams Mike
Published: December 2017

Turbomachinery active subspace performance maps are two-dimensional (2D) contour plots that illustrate the variation of key flow performance metrics with different blade designs. While such maps are easy to construct for design parameterizations with two variables, in this paper, maps will be generated for a fan blade with twenty-five design variables. Turbomachinery active subspace performance maps combine active subspaces—a new set of ideas for dimension reduction—with fundamental turbomachinery aerodynamics and design spaces. In this paper, contours of (i) cruise efficiency, (ii) cruise pressure ratio (PR), (iii) maximum climb flow capacity, and (iv) sensitivity to manufacturing variations are plotted as objectives for the fan. These maps are then used to infer pedigree design rules: how best to increase fan efficiency; how best to desensitize blade aerodynamics to the impact of manufacturing variations? In the present study, the former required both a reduction in PR and flow capacity—leading to a reduction of the strength of the leading edge bow wave—while the latter required strictly a reduction in flow capacity. While such pedigree rules can be obtained from first principles, in this paper, these rules are derived from the active subspaces. This facilitates a more detailed quantification of the aerodynamic trade-offs. Thus, instead of simply stating that a particular design is more sensitive to manufacturing variations; or that it lies on a hypothetical “efficiency cliff,” this paper seeks to visualize, quantify, and make precise such notions of turbomachinery design.
Computational Fluid Dynamics Simulation of Flow Mixing in Tunnel Kilns by Air Side Injection
Authors: Al-Hasnawi Adnan Ghareeb Tuaamah , Refaey H. A. , Redemann T. , Attalla M. , Specht E.
Published: December 2017

The mixing of the two axial flows through the ware and through the gap between ware and walls using side nozzles in the preheating zone of tunnel kiln is investigated. The three-dimensional temperature field in the cross section between the two cars is calculated using the computational fluid dynamics (CFD) tool fluent. The mixing quality is evaluated using contours, the frequency of temperature distribution, and the maximum temperature difference. The influence on the mixing behavior of injection flow rate, injection velocity, nozzles position, and nozzle number has been analyzed. The results show that using two nozzles is more effective than one nozzle if the nozzles are installed at the opposite side walls with high vertical distance. The mixing quality increases strongly until an impulse flow rate (IFR) of about 4 N. For higher values, the influence becomes relatively low. The results for the mixing temperature obtained through CFD simulation compared with analytical results show a good agreement with maximum error of 0.5%.
Numerical Simulation of the Effect of Transient Shear Stress and Rate of Heat Transfer Around Different Positions of Sphere in the Presence of Viscous Dissipation
Authors: Ashraf Muhammad , Fatima Almas
Published: December 2017

The present study is devoted to the problem of oscillatory convective flow in the presence of viscous dissipation around different positions of a sphere. The system of differential equations governing the flow phenomenon is transformed into dimensionless form by using suitable group of variables and then transformed into convenient form for integration by using primitive variable formulation. Numerical simulation based on finite difference method is carried out to analyze the mixed convection flow mechanism. Special focus is given on the transient shear stress and the rate of heat transfer characteristics and their dependency on various dimensionless parameters that is mixed convection parameter λ, Prandtl number Pr, dissipation parameter N, and angular frequency parameter ω. The angles X=30deg,90 deg, and 360deg are the favorable positions around the sphere for different parameters, where the transient rate of shear stress and heat transfer is noted maximum. Later, the obtained results are presented graphically by using Tech Plot-360 and compared with the previous work given in the literature.
Unsteady Conjugate Natural Convective Heat Transfer and Entropy Generation in a Porous Semicircular Cavity
Authors: Chamkha Ali J. , Miroshnichenko Igor V. , Sheremet Mikhail A.
Published: December 2017

The problem of unsteady conjugate natural convection and entropy generation within a semicircular porous cavity bounded by solid wall of finite thickness and conductivity has been investigated numerically. The governing partial differential equations with the corresponding initial and boundary conditions have been solved by the finite difference method using the dimensionless stream function, vorticity, and temperature formulation. Numerical results for the isolines of the stream function, temperature, and the local entropy generation due to heat transfer and fluid friction as well as the average Nusselt and Bejan numbers, and the average total entropy generation and fluid flow rate have been analyzed for different values of the Rayleigh number, Darcy number, thermal conductivity ratio, and the dimensionless time. It has been found that low values of the temperature difference reflect the entropy generation, mainly in the upper corners of the cavity, while for high Rayleigh numbers, the entropy generation occurs also along the internal solid–porous interface. A growth of the thermal conductivity ratio leads to an increase in the average Bejan number and the average entropy generation due to a reduction of the heat loss inside the heat-conducting solid wall.
A General Boundary Integral Solution for Fluid Flow Analysis in Reservoirs With Complex Fracture Geometries
Authors: Zhang Miao , Ayala Luis F.
Published: December 2017

Modeling fractured reservoirs, especially those with complex, nonorthogonal fracture network, can prove to be a challenging task. This work proposes a general integral solution applicable to two-dimensional (2D) fluid flow analysis in fractured reservoirs that reduces the original 2D problem to equivalent integral equation problem written along boundary and fracture domains. The integral formulation is analytically derived from the governing partial differential equations written for the fluid flow problem in reservoirs with complex fracture geometries, and the solution is obtained via solving system of equations that combines contributions from both boundary and fracture domains. Compared to more generally used numerical simulation methods for discrete fracture modeling such as finite volume and finite element methods, this work only requires discretization along the boundary and fractures, resulting in much fewer discretized elements. The validity of proposed solution is verified using several case studies through comparison with available analytical solutions (for simplified, single-fracture cases) and finite difference/finite volume finely gridded numerical simulators (for multiple, complex, and nonorthogonal fracture network cases).
Management of Implementation of Nanotechnology in Upstream Oil Industry: An Analytic Hierarchy Process Analysis
Authors: Motamedi Pouyan , Bargozin Hasan , Pourafshary Peyman
Published: December 2017

Nanotechnology has had revolutionary effects in various fields of industry such as electronics, pharmaceuticals, and biomaterials. However, upstream oil industry has been noticeably slow in adopting the emerging technologies. This is mainly due to the exceptionally large investments needed to implement novel technologies in this industry. However, the projections for the increasing global energy demand require that oil and gas industry inevitably move toward adopting the emerging technologies. The high risk associated with enormous investments required for this aim necessitates measured and well-researched energy policies, with regard to the implementation of nanotechnology in the oil and gas industry. This paper presents a concise summary of the research reported in the literature on the potential benefits of nanotechnology in upstream oil industry. These applications were categorized into ten groups, and presented to a pool of experts, who judged on their relative importance with respect to various decision-making criteria. All this information was then compiled into a single matrix, which indicates the priority of each investment alternative with respect to every criterion in the form of a raw number. Finally, using a decision-making software package, a dynamic analytic hierarchical process (AHP) analysis was performed, providing a route to customized investment policies.
An Experimental Study on the Performance of Drag-Reducing Polymers in Single- and Multiphase Horizontal Flow Using Particle Image Velocimetry
Authors: Alsurakji Ihab H. , Al-Sarkhi A. , Habib M. , Badr Hassan M.
Published: December 2017

This paper presents experimental investigations conducted to understand the influence of water-soluble drag-reducing polymers (DRPs) in single- and two-phase (stratified wavy) flow on flow-field characteristics. These experiments have been presented for water and air–water flowing in a horizontal polyvinyl chloride 22.5-mm ID, 8.33-m long pipe. The effects of liquid flow rates and DRP concentrations on streamlines and the instantaneous velocity were investigated by using particle image velocimetry (PIV) technique. A comparison of the PIV results was performed by comparing them with the computational results obtained by fluent software. One of the comparisons has been done between the PIV results, where a turbulent flow with DRP was examined, and the laminar–computational fluid dynamic (CFD) prediction. An agreement was found in the region near the pipe wall in some cases. The results showed the powerfulness of using the PIV techniques in understanding the mechanism of DRP in single- and two-phase flow especially at the regions near the pipe wall and near the phases interface. The results of this study indicate that an increase in DRP concentrations results in an increase in drag reduction up to 45% in single-phase water flow and up to 42% in air–water stratified flow.
Concentrating and Nonconcentrating Slurry and Fixed-Bed Solar Reactors for the Degradation of Herbicide Isoproturon
Authors: Verma Anoop , Tejo Prakash N. , Toor Amrit Pal , Bansal Palak , Sangal Vikas Kumar , Kumar Ajay
Published: December 2017

This research demonstrates scale-up studies with the development of concentrating and nonconcentrating solar reactors employing suspended and supported TiO2 for the degradation of herbicide isoproturon (IPU) with total working volume of 6 L. Novel cement beads were used as support material for fixing the catalyst particles. In the case of nonconcentrating slurry reactor, 85% degradation of IPU was achieved after 3 h of treatment with four number of catalyst recycling, whereas nonconcentrating fixed-bed reactor using TiO2 immobilized cement beads took relatively more time (10 h) for the degradation of IPU (65%) due to mass transfer limitations, but it overcame the implication of catalyst filtration post-treatment. The immobilized catalyst was successfully recycled for ten times boosting its commercial applications. High photon flux with concentrating parabolic trough collector (PTC) using fixed catalysis approach with same immobilized catalyst substantially reduced the treatment time to 4 h for achieving 91% degradation of IPU. Working and execution of pilot-scale reactors are very fruitful to extend these results for a technology development with the present leads.
Physics of Proppant Transport Through Hydraulic Fracture Network
Authors: Chang Oliver , Kinzel Michael , Dilmore Robert , Wang John Yilin
Published: December 2017

Horizontal drilling with successful multistage hydraulic fracture treatments is the most widely applied and effective method to enable economic development of hydrocarbon-bearing shale reservoirs. Once fracture networks are established, they must be propped open to maintain pathways for fluid migration through the production phase. As such, the design and application of effective and efficient proppant treatment is considered a key step to successfully develop the targeted resource. Unfortunately, the available literature and simulation tools to describe proppant transport in complex fracture networks are inadequate, and some of the fundamental mechanisms of proppant transport are poorly understood. The present study provides a critical review of relevant published literature to identify important mechanisms of particle transport and related governing equations. Based on that review, a mathematical model was developed to quantitatively predict the transport behavior of proppant particles in model fracture networks. Aspects of this mathematical model are compared against computational fluid dynamic (CFD) simulation, and implications of this work are discussed.
Extended Irreversible Thermodynamics Versus Second Law Analysis of High-Order Dual-Phase-Lag Heat Transfer
Authors: Askarizadeh Hossein , Ahmadikia Hossein
Published: December 2017

This study introduces an analysis of high-order dual-phase-lag (DPL) heat transfer equation and its thermodynamic consistency. The frameworks of extended irreversible thermodynamics (EIT) and traditional second law are employed to investigate the compatibility of DPL model by evaluating the entropy production rates (EPR). Applying an analytical approach showed that both the first- and second-order approximations of the DPL model are compatible with the traditional second law of thermodynamics under certain circumstances. If the heat flux is the cause of temperature gradient in the medium (over diffused or flux precedence (FP) heat flow), the DPL model is compatible with the traditional second law without any constraints. Otherwise, when the temperature gradient is the cause of heat flux (gradient precedence (GP) heat flow), the conditions of stable solution of the DPL heat transfer equation should be considered to obtain compatible solution with the local equilibrium thermodynamics. Finally, an insight inspection has been presented to declare precisely the influence of high-order terms on the EPRs.
Numerical Modeling of Heavy-Oil Recovery Using Electromagnetic Radiation/Hydraulic Fracturing Considering Thermal Expansion Effect
Authors: Davletbaev A. , Kovaleva L. , Zainulin A. , Babadagli T.
Published: December 2017

Production of heavy oil from deep/tight formation using traditional technologies (“cold” production, injection of hot steam, etc.) is ineffective or inapplicable. An alternative is electromagnetic (EM) heating after fracturing. This paper presents the results of a numerical study of heavy oil production from a well with hydraulic fracture under radiofrequency (RF) EM radiation. Two parameters ignored in our previous modeling studies, namely adiabatic effect and the thermal expansion of oil, are considered in the new formulation, while high gradients of pressure/temperature and high temperature occur around the well. The mathematical model calculates the distribution of pressure and temperature in the system of “well-fracture-formation.” The distribution of thermal heat source is given by the Abernetty expression. The mathematical model takes into account the adiabatic effect and the thermal expansion of heavy oil. The latter makes a significant contribution to heavy oil production. Multistage heavy production technology with heating is assumed and several stages are recognized: stage 1: “Cold” heavy oil production, stage 2: RF-EM heating, and stage 3: RF is turned off and “hot” oil production continues until the flow rate reaches its initial (before heating) value. These stages are repeated starting from the second stage. Finally, RF-EM heating technology is compared to “cold” production in terms of additional oil production and economics. When producing with RF-EM heating with power 60 kW (50 days in the second stages), the oil rate increased several times. Repeated RF-EM heating (25 days in the fourth stage) doubled the production rate. Near-well region temperature increased by ∼82 °C in the second stage with RF-EM heating. Temperature increased by ∼87 °C in the fourth stage with repeated RF-EM heating and production cycles. Economic analysis and evaluation of energy balance showed that the multistage production technology is more efficient; i.e., the lower the payback period, the greater the energy balance. With the increase in pressure difference, the payback period and energy balance increased linearly.
Dropwise Condensation on Superhydrophobic Microporous Wick Structures
Authors: Hoenig Sean H. , Bonner Richard W.
Published: December 2017

Previous research in dropwise condensation (DWC) on rough microtextured superhydrophobic surfaces has demonstrated evidence of high heat transfer enhancement compared to smooth hydrophobic surfaces. In this study, we experimentally investigate the use of microporous sintered copper powder on copper substrates coated with a thiol-based self-assembled monolayer to attain enhanced DWC for steam in a custom condensation chamber. Although microtextured superhydrophobic surfaces have shown advantageous droplet growth dynamics, precise heat transfer measurements are underdeveloped at high heat flux. Sintered copper powder diameters from 4 μm to 119 μm were used to investigate particle size effects on heat transfer. As powder diameter decreased, competing physical factors led to improved thermal performance. At consistent operating conditions, we experimentally demonstrated a 23% improvement in the local condensation heat transfer coefficient for a superhydrophobic 4 μm diameter microporous copper powder surface compared to a smooth hydrophobic copper surface. For the smallest powders observed, this improvement is primarily attributed to the reduction in contact angle hysteresis as evidenced by the decrease in departing droplet size. Interestingly, the contact angle hysteresis of sessile water droplets measured in air is in contradiction with the departing droplet size observations made during condensation of saturated steam. It is evident that the specific design of textured superhydrophobic surfaces has profound implications for enhanced condensation in high heat flux applications.
Estimating Two Heat-Conduction Parameters From Two Complementary Transient Experiments
Authors: McMasters Robert L. , de Monte Filippo , Beck James V.
Published: December 2017

A desirable feature of any parameter estimation method is to obtain as much information as possible with one experiment. However, achieving multiple objectives with one experiment is often not possible. In the field of thermal parameter estimation, a determination of thermal conductivity, volumetric heat capacity, heat addition rate, surface emissivity, and convection coefficient may be desired from a set of temperature measurements in an experiment where a radiant heat source is used. It would not be possible to determine all of these parameters from such an experiment; more information would be needed. The work presented in the present research shows how thermal parameters can be determined from temperature measurements using complementary experiments where the same material is tested more than once using a different geometry or heating configuration in each experiment. The method of ordinary least squares is used in order to fit a mathematical model to a temperature history in each case. Several examples are provided using one-dimensional conduction experiments, with some having a planar geometry and some having a cylindrical geometry. The parameters of interest in these examples are thermal conductivity and volumetric heat capacity. Sometimes, both of these parameters cannot be determined simultaneously from one experiment but utilizing two complementary experiments may allow each of the parameters to be determined. An examination of confidence regions is an important topic in parameter estimation and this aspect of the procedure is addressed in the present work. A method is presented as part of the current research by which confidence regions can be found for results from a single analysis of multiple experiments.
A Sensitivity Study of Gas Turbine Exhaust Diffuser-Collector Performance at Various Inlet Swirl Angles and Strut Stagger Angles
Authors: Siorek Michal P. , Guillot Stephen , Xue Song , Ng Wing F.
Published: December 2017

This paper describes studies completed using a quarter-scaled rig to assess the impact of turbine exit swirl angle and strut stagger on a turbine exhaust system consisting of an integral diffuser-collector. Advanced testing methods were applied to ascertain exhaust performance for a range of inlet conditions aerodynamically matched to flow exiting an industrial gas turbine. Flow visualization techniques along with complementary computational fluid dynamics (CFD) predictions were used to study flow behavior along the diffuser end walls. Complimentary CFD analysis was also completed with the aim to ascertain the performance prediction capability of modern day analytical tools for design phase and off-design analysis. The K-Epsilon model adequately captured the relevant flow features within both the diffuser and collector, and the model accurately predicted the recovery at design conditions. At off-design conditions, the recovery predictions were found to be pessimistic. The integral diffuser-collector exhaust accommodated a significant amount of inlet swirl without degradation in performance, so long as the inlet flow direction did not significantly deviate from the strut stagger angle. Strut incidence at the hub was directly correlated with reduction in overall performance, whereas the diffuser-collector performance was not significantly impacted by strut incidence at the shroud.
Modeling Reichardt's Formula for Eddy Viscosity in the Fluid Film of Tilting Pad Thrust Bearings
Authors: Deng Xin , Weaver Brian , Watson Cori , Branagan Michael , Wood Houston , Fittro Roger
Published: December 2017

Oil-lubricated bearings are widely used in high-speed rotating machines such as those used in the aerospace and automotive industries that often require this type of lubrication. However, environmental issues and risk-adverse operations have made water-lubricated bearings increasingly popular. Due to different viscosity properties between oil and water, the low viscosity of water increases Reynolds numbers drastically and therefore makes water-lubricated bearings prone to turbulence effects. The turbulence model is affected by eddy viscosity, while eddy viscosity depends on wall shear stress. Therefore, effective wall shear stress modeling is necessary in producing an accurate turbulence model. Improving the accuracy and efficiency of methodologies of modeling eddy viscosity in the turbulence model is important, especially considering the increasingly popular application of water-lubricated bearings and also the traditional oil-lubricated bearings in high-speed machinery. This purpose of this paper is to study the sensitivity of using different methodologies of solving eddy viscosity for turbulence modeling. Eddy viscosity together with flow viscosity forms the effective viscosity, which is the coefficient of the shear stress in the film. The turbulence model and Reynolds equation are bound together to solve when hydrodynamic analysis is performed, therefore improving the accuracy of the turbulence model is also vital to improving a bearing model's ability to predict film pressure values, which will determine the velocity and velocity gradients in the film. The velocity gradients in the film are the other term determining the shear stress. In this paper, three approaches applying Reichardt's formula were used to model eddy viscosity in the fluid film. These methods are for determining where one wall's effects begin and the other wall's effects end. Trying to find a suitable model to capture the wall's effects of these bearings, with an aim to improve the accuracy of the turbulence model, would be of high value to the bearing industry. The results of this study could aid in improving future designs and models of both oil- and water-lubricated bearings.
Large Eddy Simulation of Liquid Metal Turbulent Mixed Convection in a Vertical Concentric Annulus
Authors: Marocco Luca , Garita Francesco
Published: December 2017

In the present study, turbulent forced and mixed convection heat transfer to a liquid metal flowing upwards in a concentric annulus is numerically investigated by means of large eddy simulation (LES). The inner-to-outer radius ratio is 0.5. The Reynolds number based on bulk velocity and hydraulic diameter is 8900, while the Prandtl number is set to a value of 0.026. A uniform and equal heat flux is applied on both walls. LES has been chosen to provide sufficiently accurate results for validating Reynolds-averaged turbulence models. Moreover, with the thermal sublayer thickness of liquid metals being much larger than the viscous hydrodynamic one, liquid metals present a separation between the turbulent thermal and hydrodynamic scales. Thus, with the same grid resolution, it is possible to perform a LES for the flow field and a “thermal” direct numerical simulation (DNS) for the temperature field. Comparison of the forced convection results with available DNS simulations shows satisfying agreement. Results for mixed convection are analyzed and the differences with respect to forced convection at the same Reynolds number are thoroughly discussed. Moreover, where possible, a comparison with air is made.
Control
of Three Degrees-of-Freedom Wave Energy Converters Using Pseudo-Spectral
Methods
Authors: Abdelkhalik Ossama , Zou Shangyan , Robinett Rush , Bacelli Giorgio , Wilson David , Coe Ryan
Published: December 2017

This paper presents a solution to the optimal control problem of a three degrees-of-freedom (3DOF) wave energy converter (WEC). The three modes are the heave, pitch, and surge. The dynamic model is characterized by a coupling between the pitch and surge modes, while the heave is decoupled. The heave, however, excites the pitch motion through nonlinear parametric excitation in the pitch mode. This paper uses Fourier series (FS) as basis functions to approximate the states and the control. A simplified model is first used where the parametric excitation term is neglected and a closed-form solution for the optimal control is developed. For the parametrically excited case, a sequential quadratic programming approach is implemented to solve for the optimal control numerically. Numerical results show that the harvested energy from three modes is greater than three times the harvested energy from the heave mode alone. Moreover, the harvested energy using a control that accounts for the parametric excitation is significantly higher than the energy harvested when neglecting this nonlinear parametric excitation term.