bluuebunny/crossref_metadata_2025_split huggingface dataset:
Creep–Cyclic Plasticity and Damage Assessment of an SS304 Weldolet
Authors: Puliyaneth Manu , Chen Haofeng 
Published: July 2021

Abstract
Creep–fatigue and creep–ratcheting life assessment of an SS304 weldolet considering full creep–cyclic plasticity interaction is investigated using the extended direct steady cycle analysis within the linear matching method framework. The creep behavior is modeled using the Norton relationship, which is modified by the Arrhenius rule to account for the temperature variation within the weldolet. The introduction of a creep dwell increases the reverse plasticity resulting from the creep relaxation. This leads to both creep–fatigue and creep–ratcheting damage mechanisms at different regions within the weldment. For thermal load dominated loading combinations, creep ratcheting due to both cyclically enhanced creep and creep enhanced plasticity are observed based on the dwell period. The effect of dwell period, load and temperature on the creep–fatigue and creep–ratcheting interaction of a weldolet are presented. The simultaneous presence of various damage mechanisms at different locations within the weldment highlights the importance and requirement of the proposed creep–cyclic plasticity investigations at weld locations.
Economic Analysis of an Electric Thermal Energy Storage System Using Solid Particles for Grid Electricity Storage
Authors: Ma Zhiwen , Wang Xingchao , Davenport Patrick , Gifford Jeffrey , Martinek Janna 
Published: July 2021

Abstract
As renewable power generation becomes the mainstream new-built energy source, energy storage will become an indispensable need to complement the uncertainty of renewable resources to firm the power supply. When phasing out fossil-fuel power plants to meet the carbon neutral utility target in the midcentury around the world, large capacity of energy storage will be needed to provide reliable grid power. The renewable power integration with storage can support future carbon-free utility and has several significant impacts including increasing the value of renewable generation to the grid, improving the peak-load response, and balancing the electricity supply and demand. Long-duration energy storage (10–100 hours duration) can potentially complement the reduction of fossil-fuel baseload generation that otherwise would risk grid security when a large portion of grid power comes from variable renewable sources. Current energy storage methods based on pumped storage hydropower or batteries have many limitations. Thermal energy storage (TES) has unique advantages in scale and siting flexibility to provide grid-scale storage capacity. A particle-based TES system has promising cost and performance for the future growing energy storage needs. This paper introduces the system and components required for the particle TES to be technically and economically competitive. A technoeconomic analysis based on preliminary component designs and performance shows that the particle TES integrated with an efficient air-Brayton combined cycle power system can provide power for several days by low-cost, high-performance storage cycles. It addresses grid storage needs by enabling large-scale grid integration of intermittent renewables like wind and solar, thereby increasing their grid value. The design specifications and cost estimations of major components in a commercial scale system are presented in this paper. The cost model provides insights for further development and cost comparison with competing technologies.
Simulation of an ROC-Based Thermal Energy Storage System in Charge and Discharge Cycles
Authors: Nalbandian Rozina N. , Girgis Karen U. , Kong Benjamin T. , Aguirre Ulyses , Victorio Adrian Gil C. , Lee Justin Andrew , Baghaei Lakeh Reza 
Published: July 2021

Abstract
In this paper, Computational Fluid Dynamics (CFD) is employed to investigate the heat transfer characteristics of Reverse Osmosis Concentrate (ROC) as an alternative, low-cost thermal energy storage medium. Thermal energy storage is a critical component for increasing efficiency and dispatchability of solar thermal and combined heat and power plants. The byproduct of water desalination, ROC, is classified as an industrial waste by the U.S. Environmental Protection Agency as it has negative effects on vegetation and sea-life. Currently, ROC disposal includes deep-well injection, surface discharge to rivers, discharge to the ocean, and evaporation ponds. The composition and thermal properties of ROC salt vary depending on the original source of feedwater. Transient models are utilized to understand the heat transfer between the heat transfer fluid and storage fluid (i.e., ROC) over time. This simulation also provides valuable information in determining the optimal operating conditions of the thermal energy storage system. This information will be used in conjunction with a cost analysis, focused on the transportation, processing and containment cost of the energy storage, that aims to determine the economic feasibility of ROC technology in large scale, commercial applications.
A Comparative Study on the Effectiveness of Evaporative and Phase Change Material Cooling Vests for People With Paraplegia
Authors: Mneimneh Farah , Ghaddar Nesreen , Ghali Kamel , Moussalem Charbel , Omeis Ibrahim 
Published: July 2021

Abstract
Personal cooling vests to alleviate thermal strain in persons with thoracic spinal cord injury (SCI), named paraplegia, were tested. Mainly, phase change material (PCM) cooling vests were the most frequent type applied at different exercises and ambient conditions. Published results of PCM cooling vests indicated its significant effect in reducing body core temperature for persons having more than 50% of their trunk skin as sensate. Nevertheless, preferences of persons with SCI obtained from subjective voting during experimental studies revealed that the use of PCM cooling vests caused additional burden weight on the body and sometimes restricted the movement. It is of interest to investigate the effect of an alternative personal evaporative cooling vest (ECV), characterized by light weight and practical use without hindering body movement of persons with SCI. In this study, it is aimed to compare the effect of ECV on the physiological and psychological responses of persons with SCI compared to that of PCM cooling vests under the same ambient conditions and metabolic rates. The research methodology included human subject experiments for persons with mid-thoracic (T4-T8) and low-thoracic (T9-T12) injury where the sensate skin of the trunk is at least 50% of its area. Thirteen participants were recruited to perform an arm-crank exercise at a constant load of 30 W for 30-min while using ECV inside a controlled climatic chamber of hot conditions (30°C, 4 0% RH). Measurements of body core and skin temperatures as well as thermal comfort and sensation, perceived exertion and skin wettedness were done. Furthermore, Multi-way ANOVA test was conducted to analyse the results of three tests: no vest (NV), with ECV, and with PCM. Findings of mid- and low-thoracic groups showed similar effectiveness of ECV compared to PCM cooling vest in reducing core temperature, yet the change in perceived exertion was better with the use of ECV due to its light weight.
Femtosecond Two-Photon 3D Lightfield Lithography
Authors: Jakkinapalli Aravind , Baskar Balaji , Wen Sy-Bor 
Published: July 2021

Abstract
Based on the successful single-photon 3D light field photolithography we demonstrated in the last year, we extend the methodology to femtosecond 3D light field lithography. Compared with our previous single-photon work with UV LED light, using femtosecond light and the associated two-photon light absorption in 3D light field lithography can cure photoresist only around designed voxel locations in a 3D space. Such a two-photon scheme can prevent the unwilling curing of photoresists along the optical paths of rays before arriving at designed voxel locations, which is observed in our previous UV LED-based single-photon 3D light field lithography. The experimental scheme of femtosecond two-photon 3D light field lithography starts from delivering uniform femtosecond laser pulses to a spatial light modulator. The designed pixel map is presented on the spatial light modulator and then delivered to a microlens array to construct a 3D virtual image in the free space. By compressing the 3D virtual image in a photoresist layer with a microscope system, we can successfully generate different microscale 3D patterns without relying on scanning processes as in traditional 3D lithography. In this study, we present preliminary results of (a) algorithms developed to generated 3D patterns with femtosecond light, which should satisfy additional constraints when femtosecond light is used, and (b) 3D patterns generated in photoresists with femtosecond two-photon 3D light field lithography.
The Influence of Deterministic Surface Roughness and Free-Stream Turbulence on Transitional Boundary Layers: Heat Transfer Distributions and a New Transition Onset Correlation
Authors: Gramespacher Christoph , Stripf Matthias , Bauer Hans-Jörg 
Published: July 2021

Abstract
Heat transfer measurements in transitional flat plate boundary layers subjected to surface roughness, strong pressure gradients and free stream turbulence are presented. The surfaces considered, consist of a smooth reference and twenty six deterministic surface topographies that vary in roughness element aspect ratio, height and density. They are designed to cover the full range of roughness regimes from smooth over transitionally rough to fully rough. For each surface, two pressure distributions, characteristic for a suction and a pressure side turbine vane, are investigated. Inlet Reynolds numbers range from 3.0 · 105 to 6.0 · 105 and inlet turbulence intensity is varied between 1% to 8%. Furthermore, different turbulence Reynolds numbers, i.e. turbulence length scales, are realized while the incident turbulence intensity is kept constant. Additionally, the turbulence intensity and Reynolds stress distributions in the free-stream along the flat plate are measured using x-wire probes. Results show a strong influence of roughness and turbulence intensity on the onset of transition. The new data set is used to develop an improved correlation considering the roughness height, density and shape as well as the turbulence intensity and turbulent length scales.
Numerical Simulation and Analysis of Effect of Injection Volume on Biomass Particle Cyclone Venturi Dryer
Authors: Jia Guohai , Tian Guoshuai , Gao Zicheng , Huang Dan , Li Wei , Li Dai , Zhang Qiuyao 
Published: July 2021

Abstract
Cyclone venturi dryer is suitable for drying materials with large particle size and wide distribution. The working process of cyclone venturi dryer is a very complicated three-dimensional and turbulent motion, so it is difficult to be studied theoretically and experimentally. In order to study the internal flow characteristics of the biomass particle cyclone venturi dryer, the computational fluid dynamics (CFD) software was used to simulate the gas-solid two-phase flow field inside the cyclone venturi dryer. The continuous phase adopts the Realizable k-ε turbulence model and the particle phase is discrete. The effects of different injection volume on the pressure, velocity, and temperature fields inside a cyclone venturi dryer were analyzed. The results showed that the maximum pressure drop and velocity change inside the dryer were at the venturi pipe. The wet material of the cyclone venturi dryer was inhaled into the venturi contraction tube by the negative pressure formed after the highspeed airflow was ejected, thus the mixture was completed in the venturi throat. The wood debris material was mixed with the high-speed hot gas flow in the venturi throat and then sprayed into the diffusion pipe. In the diffusion pipe of venturi, the heat and mass transfer process of wet wood debris and heat flow in venturi diffusion tube was completed. It is in good agreement with the simulation results. This study can provide a reference for the optimization design of the related cyclone venturi dryer structure.
Experimental Investigation on the Effects of Inclination Angle on Heat Transfer Performance of a Liquid Metal High-Temperature Oscillating Heat Pipe
Authors: Wu Mengke , Ji Yulong , Feng Yanmin , Yang Xin , Li Yadong , Liu Qinan 
Published: July 2021

Abstract
The liquid metal high-temperature oscillating heat pipe (LMHOHP) is a kind of high efficiency heat transfer device, which can function in high-temperature environments above 500°C. In this paper, the effects of inclination angle on the startup and heat transfer performance of a LMHOHP were investigated experimentally. The sodium-potassium alloy (potassium 78%) was used as the working fluid of the LMHOHP and the filling ratio was 50%. The start-up characteristics and heat transfer performance of the LMHOHP at four inclination angles of 0°, 30°, 60° and 90° were tested when the operating temperatures were 150°C and 400°C, respectively. Experimental results show that (1) The LMHOHP can start-up and function at all the tested inclination angles, the maximum temperatures of the evaporator and condenser can exceed 1000°C and 700°C, respectively. (2) The thermal resistance of the LMHOHP decreases with inclination angle increases, the thermal resistance at the inclination angle of 90° decreases by up to 32.9%, 41.6% and 55.9% compared with that at the inclination angle of 60°, 30° and 0°, respectively. (3) When the input power exceeds 3000W, the flow patterns of LMHOHP at the inclination angle of 90°, 60° and 30° can be changed from the oscillating motion to the unidirectional circulating flow. (4) Compared with the operating temperature of 150°C, the heat transfer performance of the LMHOHP improves at the operating temperature of 400°C, at the input power of 3457W and the inclination angle of 90°, the minimum thermal resistance of LMHOHP is 0.075°C/W. The results shown that the LMHOHP has a good adaptability to working conditions which further extends the application range of oscillating heat pipe.
Flow Dynamics Over Two Cylinders in Tandem Subjected to Different Heating Cases
Authors: Homsi Rami , Islam MD , Fatt Yap Yit , Janajreh Isam 
Published: July 2021

Abstract
Heated and unheated flows with forced convection over two fixed circular cylinders in tandem are studied numerically for 80 ≤ Re ≤ 250 and 1 ≤ T* ≤ 2.3. Three different spacing ratios (L/D) = [2, 4, 8] are considered under three heating conditions. The scenarios considered are (1) heated upstream and unheated downstream cylinders, (2) unheated upstream and heated downstream cylinders and (3) heated upstream and downstream cylinders. These scenarios represent the limiting case for a cross-flow heat exchanger, where the downstream tubes are at increasingly lower or higher temperature for cooling or heating, respectively. The global aerodynamic forces on the cylinder as vortices shed was investigated. The flow is visualized by plotting the streamlines, temperature fields, and velocity magnitude contours for the different spacing ratios and compared to the flow regimes in literature namely, Extended-body, Reattachment, and Co-shedding regimes. The drag and surface heat transfer coefficients are analyzed for different scenarios. The effect of heating on the fluid properties and the resulted wakes in the flow are found to be strongly influenced by Re and L/D. The scenario of heated upstream and unheated downstream cylinders was found to increase the mean drag coefficient Cd on the upstream cylinder for L/D = 2 & 4 but is not as evident for the downstream cylinder. The heat transfer coefficient h on the upstream cylinder remained approximately the same regardless of a heated or unheated downstream cylinder. In contrast, h of the downstream cylinder decreases for the scenario of heated upstream and downstream cylinder.
Development of a Fast Fluid Dynamics Model Based on PISO Algorithm for Simulating Indoor Airflow
Authors: Li Sibo , Qiao Hongtao 
Published: July 2021

Abstract
Real-time or faster-than-real-time flow simulation is crucial for studying airflow and heat transfer in buildings, such as building design, building emergency management and building energy performance evaluation. Computational Fluid Dynamics (CFD) with Pressure Implicit with Splitting of Operator (PISO) or Semi-Implicit Method for Pressure Linked Equations (SIMPLE) algorithm is accurate but requires great computational resources. Fast Fluid Dynamics (FFD) can reduce the computational effort but generally lack prediction accuracy due to simplification. This study developed a fast computational method based on FFD in combination with the PISO algorithm. Boussinesq approximation is adopted for simulating buoyancy effect. The proposed solver is tested in a two-dimensional case and a three-dimensional case with experimental data. The predicted results have good agreement with the experimental results. In the two test cases, the proposed solver generates lower Root Mean Square Error (RMSE) compared to the FFD and at the same time, the proposed method reduces computational cost by a factor of 10 and 13 in the two cases compared to CFD.
Distributed Temperature Sensing for Erosion Detection and DoC Estimation: The Peru LNG Experience in Ayacucho and Ica Departments
Authors: Ravet Fabien , Silva Christian , Gil Rodolfo , Rochat Etienne , Maguire Simon 
Published: July 2021

Abstract
Pipelines often cross challenging terrains where natural hazards are the main risk for their integrity. Environmental conditions can also worsen over the infrastructure lifetime. To reduce the risk of disasters, integrity programs are developed and require tools for early detection of threats that can lead to a failure with dramatic social, environmental and economic consequences. Fiber optic based Geotechnical Monitoring System (GMS) have been used and implemented as an efficient prevention tools of these programs.
As a good example, GMS is successfully in operation to detect landslides using Distributed Strain Sensing along the Sierra section of the Peru LNG pipeline since 2010. The continuous operation of the GMS also revealed that infiltration, erosion and sand dune migration can be detected using Distributed Temperature Sensing (DTS). First, hydraulic erosion was evidenced in the Sierra region. More recently, events whose origin is eolian erosion and sand dune migration have been identified. A thermal analysis was then conducted to analyze the measured thermal signatures of the detected event. It revealed that the DoC (Depth-of-Cover) can be computed from the temporal response of the fiber optic cable. The time lag between ambient temperature and temperature of the cable directly relates to its burial depth. The obtained data are compared with site inspection observation which confirm the validity of the DTS approach. The method, combining DTS measurements on existing communication cable with thermal analysis, offers the ability to monitor erosion related geohazards in both Sierra and desert sections of the pipeline. The results of the presented work illustrate the potential value of fiber optic sensing to mitigate geohazard risks. It not only enhances the efficiency of the integrity program detecting and localizing threats, it also improves and rationalizes the maintenance activities as focused surveys can be conducted.
EPGEO-ARPEL Latin America Project: Technical Guides on Monitoring and Geohazard Control Works in Pipelines
Authors: Oliveros Francisco , Ivorra Leandro , Aristizabal Jaime 
Published: July 2021

Abstract
Since 2004, the Geotechnical Professional Team (EPGEO) from the Regional Association of Oil and Gas Companies in Latin America and the Caribbean (Asociación Regional de Empresas de Petróleo y Gas Natural en Latinoamérica y el Caribe, ARPEL) has been working on a knowledge management-related project for the Oil & Gas industry, consisting in the creation of three technical guides on Pipeline Integrity Management given the occurrence of geohazards in Hydrocarbon Transportation Systems.
This initiative comprises the creation of 3 guides related to:
i) Guide 1: Monitoring Geohazards for Pipeline Integrity,
ii) Guide 2: Geotechnical Mitigation Works in Pipelines,
iii) Guide 3: Geotechnical Risk in Pipelines.
The EPGEO published Guide 1 in 2016 and made a presentation at the 2017 IPG (IPG2017-2538), while Guide 2 will be completed by 2021. Guide 3 will be created in 2021–2023.
This document shows the methodology and contents for preparing the first two guides, focusing on Guide 2, which comprises different alternatives, analyses and technical solutions to the occurrence of geohazards that might affect the integrity of a pipeline transportation system.
The Effects of Attentional Focus and Skill Level on the Performance of Golf Putting
Authors: Chen Chih-Chia , Ryuh Yonjoong , Luczak Tony , Lamberth John 
Published: July 2021

The purpose of this study was to examine the distance of varying focus of attention for experienced and novice golfers on a golf putting task. Forty-eight experienced and 48 novice golfers were randomized into four attentional focus conditions: control (no instruction), internal (i.e., focus on the arm movement), external proximal (i.e., focus on the golf club), and external distal (i.e., focus on the target) conditions. Performance outcomes (the perceived level of confidence and number of golf putts made) were recorded. Experienced golfers had better performance outcomes than novice golfers. The external proximal focus was specifically beneficial for novice golfers, while experienced golfers had an advantage in both external focus instructions. The external proximal focus might enable a perception-action process for novice golfers to compare the relationship between action planning and the surrounding environment. In addition, the transition to expertise might result in no difference between both external focus instructions for experienced golfers.
Polycyclic Aromatic Hydrocarbons and Carbon Isotopes in a Palsa Peat (Bol’shezemel’skaya Tundra)
Authors: Vasil’chuk Yu. K. , Belik A. D. , Budantseva N. A. , Gennadiev A. N. , Vasil’chuk A. C. , Vasil’chuk J. Yu. , Zavgorodnyaya Yu. A. , Ginzburg A. P. , Bludushkina L. B. 
Published: July 2021

Abstract
The content of polycyclic aromatic hydrocarbons (PAHs) and carbon isotope composition in the peat of a palsa near Eletsky settlement, Vorkuta urban district, Komi Republic are analyzed. The carbon isotope composition of peat varies from –28.05 to –30.05‰ (average –29.15‰). The total PAH content varies from 11 to 360 ppb, with an average of 63 ppb and a median value of 34 ppb. Heavy compounds, such as benzo(a)anthracene and benzofluoranthenes, are prevalent among PAHs. The presence of PAHs in the peat is determined by three main factors: technogenic impact, wildfires, and biogeochemical soil processes. The prevalence of benzo(a)anthracene in the upper part of the palsa down to the bottom of the active layer suggests an anthropogenic impact (the influence of transport and domestic fuel combustion). The share of benzo(a)anthracene decreases with depth, while the share of benzofluoranthenes increases. Two sharp peaks of PAH content (260 and 360 ppb) are observed; they coincide with a local increase of carbon isotope values, most likely resulting from wildfires. The minimums in PAH content are presumably determined by the biogeochemical factor and the input of polyarenes generated by decomposition of plant residues. Carbon isotope composition of peat mainly reflects the isotope composition of vegetation, the degree of peat moistening, and the influence of pyrogenic factor.