bluuebunny/crossref_metadata_2025_split huggingface dataset:
Model Input and Output Dimension Reduction Using Karhunen–Loève Expansions With Application to Biotransport
Authors: Alexanderian Alen , Reese William , Smith Ralph C. , Yu Meilin 
Published: July 2019

Abstract
We consider biotransport in tumors with uncertain heterogeneous material properties. Specifically, we focus on the elliptic partial differential equation (PDE) modeling the pressure field inside the tumor. The permeability field is modeled as a log-Gaussian random field with a prespecified covariance function. We numerically explore dimension reduction of the input parameter and model output. Specifically, truncated Karhunen–Loève (KL) expansions are used to decompose the log-permeability field, as well as the resulting random pressure field. We find that although very high-dimensional representations are needed to accurately represent the permeability field, especially in presence of small correlation lengths, the pressure field is not sensitive to high-order KL terms of the input parameter. Moreover, we find that the pressure field itself can be represented accurately using a KL expansion with a small number of terms. These observations are used to guide a reduced-order modeling approach to accelerate computational studies of biotransport in tumors.
Development of In-Service Inspection Rules for Liquid-Metal Cooled Reactors Using the System Based Code Concept
Authors: Takaya Shigeru , Asayama Tai , Yada Hiroki , Thomas Roberts A. , Schaaf Frank J. 
Published: July 2019

Abstract
Inservice inspection rules for liquid-metal cooled plants were historically provided by Section XI, Division 3 of the ASME Boiler and Pressure Vessel Code. However, some parts of the Code, such as acceptance standards for the examination of class 1 and 2 components remained as being in the course of preparation. Although no major revisions were made to Division 3 since the first issue in 1980, a newly developed and published Code Case N-875 now provides alternative examinations to the methods previously contained in Division 3. The Code Case was developed using the System Based Code (SBC) concept pursuing rationalization of codes and standards based on reliability targets throughout a plant's service life. In this paper, an overview of the Code Case is presented. The technical foundation to establish the applicability of these alternative examinations as delineated in the Code Case consists of stage I and II evaluations with compensating individual considerations. Stage I is a structural integrity evaluation without the contribution of inservice inspections, while stage II is evaluation of the detectability of a postulated flaw. Not only conventional direct detection methods, but also indirect detection methods are permitted to be employed through the stage II evaluation. Furthermore, the detailed evaluation procedures are illustrated through the application of the Code Case's evaluation criteria to the primary heat transport piping system of a prototype sodium-cooled fast breeder reactor in Japan, specifically Monju.
Forced Convection Heat Transfer of a Giesekus Fluid in Circular Micro-Channels Subjected to a Constant Wall Temperature
Authors: Norouzi M. , Rezaie M. R. 
Published: July 2019

Abstract
In this paper, an exact analytical solution for forced convective heat transfer of nonlinear viscoelastic fluid in isothermal circular micro-channel is presented. The nonlinear Giesekus constitutive equation is used to model the Giesekus fluid heat transfer in micro-channel with constant wall temperature, which is the main innovative aspect of the current study. This constitutive equation is a powerful tool and able to model the fractional viscometric functions, extensional viscosity, and elastic property. The solution of temperature profile and Nusselt number is obtained based on the Frobenius method. The effects of Weissenberg number, mobility factor, slip coefficient, and Navier index on temperature distribution, velocity profile, and Nusselt number are investigated in detail. The results show that the increases in both slip coefficient and Navier index cause the increases in slip velocity and maximum dimensionless temperature at the wall and the micro-channel center, respectively. Moreover, the Nusselt number has an upward trend with increases in slip coefficient and Navier index parameters. The results are indicated that the flow and temperature fields have a complex relation with mobility factor which controls the level of the nonlinearity of the Giesekus model. Additionally, three correlations for Nusselt number of Giesekus flow in micro-channel are presented.
Effects of Hall Current and Magnetic Field Inclination on Hydromagnetic Natural Convection Flow in a Micro-Channel With Asymmetric Thermal Boundary Condition
Authors: Jha Basant K. , Malgwi Peter B. 
Published: July 2019

AbstractThis study examines the impact of induced magnetic field and Hall current on steady fully developed hydromagnetic natural convection flow in a micro-channel under the action of an inclined magnetic field. The mathematical model responsible for the present physical situation is presented in a dimensionless form under relevant boundary conditions. The governing coupled equations are solved exactly. A parametric study of some physical parameters is conducted and a representative set of numerical results for the velocity field, the induced magnetic field, induced current density, volume flow rate, and skin friction on the micro-channel surfaces are illustrated graphically. It is observed that magnetic field inclination plays an important role in flow formation inside the micro-channel. Numerical computation reveals that the increase in inclination angle reduces the hydromagnetic drag leading to enhancement in primary fluid velocity, while the impact is just converse on the secondary fluid velocity. Furthermore, the increase in Hall current parameter increases the magnitude of the fluid velocity in both primary and secondary flow directions.
Numerical Investigation of Nonisothermal Cavitating Flows on Hydrofoils by Means of an Extended Schnerr–Sauer Model Coupled With a Nucleation Model
Authors: De Giorgi Maria Grazia , Ficarella Antonio , Fontanarosa Donato 
Published: July 2019

Abstract
This work aimed to investigate cavitating flows of water, liquid hydrogen, and nitrogen on hydrofoils numerically, using the open source code openfoam. The Eulerian homogeneous mixture approach has been used, consisting in a mass transfer model, which is based on the combination of a two-phase incompressible unsteady solver with a volume of fluid interface tracking method. Thermal effects have been introduced by means of the activation of energy equation and latent heat source terms plus convective heat source term. The dependency of the saturation conditions to the temperature has been defined using Antoine-like equations. An extended Schnerr–Sauer model based on the classical nucleation theory (CNT) has been implemented for the computation of the interfacial mass transfer rates. In order to investigate the nucleation effects, an extension of the CNT has been considered by coupling the population balance equation (PBE)/extended quadrature-based method of moments with the computational fluid dynamics (CFD) model, which has been defined in combination with a transport equation for the nuclei density. Results showed that nucleation determined a nonuniform field of nuclei density so as to produce a reduction of the temperature drop inside the vapor bubbles, as well as a warmed wake downstream the vapor cavity. Unsteady computations also revealed an influence of the nucleation on the dynamics of the vapor cavity and the bubble detachment.
Manufacturing of Extremely Low D/t LSAW Welded Pipe
Authors: Patel Jigar , Chauhan Gautam , Goyal Devendra , Mehta Harshal , Chauhan Gagandeep 
Published: July 2019

Critical offshore pipelines require extremely low D/t (Outer diameter to wall thickness ratio) pipes, that pose a manufacturing challenge using conventional practices and operational toolings. Such pipes are most often manufactured through the seamless route, due to the D/t ratio. But seamless pipe are more expensive as compared to welded pipes, along with having higher lead times due to fewer manufacturers. There is also a concern with the uniformity of wall thickness throughout the pipe body due to the manufacturing process, but with an advantage of better properties citing homogenous composition due to absence of a weld seam. Though in the last couple of decades, owing to advances in the welding technology, the weld seam of a welded pipe has proved to be superior to the base metal plates/coils in terms of its strength integrity.
To manufacture such pipes through the LSAW (Longitudinal Submerged Arc Welded) process requires major overhauling and process modifications at practically all the stages of the process flow. The low diameter and high wall thickness become very demanding when it comes to bending the plate and then welding (SAW) from the inside due to space constraints.
This paper describes in detail the challenges faced and overcoming of the difficulties in manufacturing an 18″ diameter, 35 mm wall thickness LSAW pipe (D/t ratio of 13) for a major oil & gas player, by development of new designed toolings for various equipment like plate crimping, pipe forming and mechanical expander; new lubrication oil; and optimizing the process parameters, as the major factors contributing to success. The tooling design modifications were done in-house, along with the development of a new lubrication oil and its treatment in plant. This enabled Welspun Corp to surpass the equipment capacities prescribed by the OEMs, and set a new benchmark in the industry for the production of extremely low D/t welded pipes, with excellent mechanical properties along with impeccable pipe dimensions.
Deepwater Pipelines: Design, Installation and Testing
Authors: Pandit Saurav , Kishore Raj 
Published: July 2019

Hydrocarbons are the major source of energy in the world. While the global energy demand continues to rise, the shallow water hydrocarbon reserves currently under production are getting exhausted. This has encouraged all major E&P (Exploration & Production) companies around the world to look towards exploration and development of newer deepwater offshore reserves, hitherto largely left untouched. Furthermore, gas reserves-rich nations are also showing a keen interest in exploring new gas markets to boost their exports and, in the process, provide a solution to the energy scarcity of other parts of the world.
The two factors mentioned above — the need for newer energy reserves and the urge to tap new energy markets — coupled with the safety, reliability, and cost-effectiveness of pipelines have contributed to the growing number of deepwater gas pipeline projects being executed around the world.
“Deepwater Pipelines” per se is not a new concept. Many deepwater pipelines have already been installed in different parts of the world. However, for the Indian energy sector, this is a relatively new development, with the exception of KG basin deepwater pipelines. The Indian government’s HELP (Hydrocarbon Exploration and Leasing Policy) and proposed trans-national submarine gas pipelines are likely to serve as the harbingers of future deepwater pipeline projects in Indian oil & gas sector.
Although the technical and codal requirements for deepwater pipelines are the same as that applicable for any shallow water offshore pipeline, there are a few nuances that must be considered extremely important to successfully implement any deepwater pipeline project. This paper elucidates the deepwater pipeline considerations such as pipeline route selection, flow assurance, line pipe material & wall thickness selection, pipeline installation analysis, seabed intervention techniques, alternative integrity validation (AIV) etc.
New Materials for Protection of City Gas Distribution Networks
Authors: Dasgupta Chanchal 
Published: July 2019

Polyethylene pipes and Steel pipes with 3LPE coatings are integral part of a citygas distribution network. These are being used in India since late 80’s. Standard MDPE and HDPE materials are Butene copolymers of Ethylene, where Butene (C4) is added as comonomer to form the side branches of linear Polyethylene (C2) chains. The research on PE materials have improved various attributes of the polymer, providing them with higher durability, pressure resistance and service life.
One such development is use of Hexene (C6) as a copolymer replacing Butene (C4) to make an Ethylene Hexene copolymer providing superior resistance to mechanical damages and slow crack growth during installation and service. For PE100 Orange pipe materials for low / medium pressure distribution system, the new hexene PE copolymer, offers much superior resistance to slow crack growth. Hence it is ideal for Trenchless installations like HDD or pipe bursting, where pulling the pipe through the bore in the ground may substantially notch and scratch the pipe or coating. Using a Hexene PE service life of the pipe is not affected despite the demanding installation techniques due to higher entanglement of polymer chains. These types of PE materials are already being used by Indian CGD Industry for past 2–3 years.
For 3LPE coated steel pipes for high pressure gas mains as well as trunk lines, Hexene based Black PE top coat has been adopted by several Gas companies. This is mainly due to two advantages. They offer a higher upper design temperature limit of +90 C (compared to +80 C as per international specification (ISO21809-1). They also offer material savings as 10% lower thickness compared to standard PE top coat is able to meet and exceed all system requirements. The paper deals with the mechanism of these new polymers that helps to offer these superior properties.
City Gas Distribution Challenges to Indraprastha Gas Limited (IGL) From Electrical Aspects
Authors: Chaudhary Sushant K. , Deb Amit Kumar 
Published: July 2019

Indraprastha Gas Limited (IGL) is India’s biggest organization in the field of City Gas Distribution (CGD) and this has happened by overcoming the several challenges from the electrical aspect also. Following are some of the initiatives taken from the electrical aspects to contribute in the growth of the company:
1. Installation and commissioning of the CNG set-up at Retail Outlets (RO) of the Oil Marketing Companies (OMCs) and Dealer Owned Dealer Operated (DODO) sites.
2. In-house installation and commissioning of the UPS with redundancy scheme at CNG re-fueling stations.
3. In-house installation and commissioning of the LED lights in place of the conventional lights (MH/HPMV).
4. In-house installation and commissioning of the Gas Generators in place of Diesel Generators.
5. In-house installation and commissioning of the 15HP VFDs in place of conventional motor starters for running the air compressors and specific engine driven gas compressors (1200 SCMH) through Gas Generators.
6. In-house installation and commissioning of the 11KV/0.4KV Package Sub-Station (PSS) of different ratings.
Online Leak Arrest in Valve: A Case Study
Authors: Dixit Anurag , Tanna Nilesh 
Published: July 2019

Pipeline integrity is essential for reliable pipeline operations, for preventing expensive downtime and failures resulting in leaking or spilling oil / gas content to the environment. Leaks can cost industries millions of dollars in loss of energy, while increasing emissions, creating safety hazards, and lowering the reliability of operations. Valves and piping systems can fail in a number of ways. Pipelines are widely used for transportation of fluids like oil & natural gas over long distances to the power plants, public supplies and various industries due to safety, efficiency and low cost. High pressure pipelines are generally buried below the ground level for safety, economic and environmental purposes. For smooth and safe operation of pipeline, there are some associated facilities underground as well above ground facilities like Valves, IJ, Fittings, Launcher & Receiver known as pipeline system. To maintain the integrity of the pipeline system, these facilities need periodic maintenance for their effective operability up to their design life. Valves are one the critical component of the pipeline system and failure of it may cause serious hazard and reduce the control over the various parameters like flow & pressure in the pipeline. Shutting down to repair the leak means a loss in associated industry’s production leading to revenue loss.
Darod - Jafarabad Pipeline (DJPL) is one the Natural Gas Pipeline laid by Gujarat State Petronet Limited (GSPL) to transport natural gas in the coastal region of Saurashtra in Gujarat. DJPL is a 212 KM long pipeline with 10 nos. of SV stations. There was leakage observed from bolted body of Ball Valve installed at Intermediate Pigging Station (IPS) and SV-6 of DJPL and these valves are butt welded and in upstream side which need shutdown of pipeline for maintenance or replacement. Maintenance of valve becomes critical, if there is gas leakage from valve body and the pipeline operation cannot be obstructed due to commitment with downstream customers. In such a situation, Stopple-in is the method to isolate the valve without obstructing / shutting the flow in the pipeline. The valves were in upstream side wherein replacement of valve was done by Stopple-in and Cross plugging method. However, gas leakage was from valve body so that hot work (i.e. pipe cutting) for stopple-in was also a challenge. To arrest the leak from bolted section of valve body, sealant injection methodology was adopted. Before applying this technology on high pressure live pipeline, GSPL insisted to perform the demonstration on prototype arrangement. This prototype was manufactured in the way that it has a manmade leakage point. After sealant injection in the system to arrest the leak, system was kept under high pressure of 55 Bar(g) for 24 hours. During demonstration, system sustained the pressure without any failure at leakage point. After successful demonstration, said methodology applied on leakage valve installed on high pressure line without any shutdown to arrest the leak.
Diagnosis of elevated intracranial pressure in critically ill adults: systematic review and meta-analysis
Authors: Fernando Shannon M , Tran Alexandre , Cheng Wei , Rochwerg Bram , Taljaard Monica , Kyeremanteng Kwadwo , English Shane W , Sekhon Mypinder S , Griesdale Donald E G , Dowlatshahi Dar , McCredie Victoria A , Wijdicks Eelco F M , Almenawer Saleh A , Inaba Kenji , Rajajee Venkatakrishna , Perry Jeffrey J 
Published: July 2019

AbstractObjectivesTo summarise and compare the accuracy of physical examination, computed tomography (CT), sonography of the optic nerve sheath diameter (ONSD), and transcranial Doppler pulsatility index (TCD-PI) for the diagnosis of elevated intracranial pressure (ICP) in critically ill patients.DesignSystematic review and meta-analysis.Data sourcesSix databases, including Medline, EMBASE, and PubMed, from inception to 1 September 2018.Study selection criteriaEnglish language studies investigating accuracy of physical examination, imaging, or non-invasive tests among critically ill patients. The reference standard was ICP of 20 mm Hg or more using invasive ICP monitoring, or intraoperative diagnosis of raised ICP.Data extractionTwo reviewers independently extracted data and assessed study quality using the quality assessment of diagnostic accuracy studies tool. Summary estimates were generated using a hierarchical summary receiver operating characteristic (ROC) model.Results40 studies (n=5123) were included. Of physical examination signs, pooled sensitivity and specificity for increased ICP were 28.2% (95% confidence interval 16.0% to 44.8%) and 85.9% (74.9% to 92.5%) for pupillary dilation, respectively; 54.3% (36.6% to 71.0%) and 63.6% (46.5% to 77.8%) for posturing; and 75.8% (62.4% to 85.5%) and 39.9% (26.9% to 54.5%) for Glasgow coma scale of 8 or less. Among CT findings, sensitivity and specificity were 85.9% (58.0% to 96.4%) and 61.0% (29.1% to 85.6%) for compression of basal cisterns, respectively; 80.9% (64.3% to 90.9%) and 42.7% (24.0% to 63.7%) for any midline shift; and 20.7% (13.0% to 31.3%) and 89.2% (77.5% to 95.2%) for midline shift of at least 10 mm. The pooled area under the ROC (AUROC) curve for ONSD sonography was 0.94 (0.91 to 0.96). Patient level data from studies using TCD-PI showed poor performance for detecting raised ICP (AUROC for individual studies ranging from 0.55 to 0.72).ConclusionsAbsence of any one physical examination feature is not sufficient to rule out elevated ICP. Substantial midline shift could suggest elevated ICP, but the absence of shift cannot rule it out. ONSD sonography might have use, but further studies are needed. Suspicion of elevated ICP could necessitate treatment and transfer, regardless of individual non-invasive tests.RegistrationPROSPERO CRD42018105642.
DiffQue
Authors: Thukral Deepak , Pandey Adesh , Gupta Rishabh , Goyal Vikram , Chakraborty Tanmoy 
Published: July 2019

Automatic estimation of relative difficulty of a pair of questions is an important and challenging problem in community question answering (CQA) services. There are limited studies that addressed this problem. Past studies mostly leveraged expertise of users answering the questions and barely considered other properties of CQA services such as metadata of users and posts, temporal information, and textual content. In this article, we propose DiffQue, a novel system that maps this problem to a network-aided edge directionality prediction problem. DiffQue starts by constructing a novel network structure that captures different notions of difficulties among a pair of questions. It then measures the relative difficulty of two questions by predicting the direction of a (virtual) edge connecting these two questions in the network. It leverages features extracted from the network structure, metadata of users/posts, and textual description of questions and answers. Experiments on datasets obtained from two CQA sites (further divided into four datasets) with human annotated ground-truth show that DiffQue outperforms four state-of-the-art methods by a significant margin (28.77% higher F
1
score and 28.72% higher AUC than the best baseline). As opposed to the other baselines, (i) DiffQue appropriately responds to the training noise, (ii) DiffQue is capable of adapting multiple domains (CQA datasets), and (iii) DiffQue can efficiently handle the “cold start” problem that may arise due to the lack of information for newly posted questions or newly arrived users.