bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic parameters and direct and maternal effects for important traits in late‐feathering Qingyuan partridge hens in China
Authors: Kang Huimin , Li Shanshan , Li Hua , Gan Jiankang , Luo Jieling , Zhang Zhengfen , Deng Xuqing , Wei Jindui , Li Gen
Published: October 2020

Qingyuan partridge chicken is an important indigenous chicken in China. In its breeding schemes, chickens are usually selected at the age of 105‐day‐old for five traits, including body weight (BW), shank length (SL), shank girth (SG), comb height (CH) and feather maturity (FM). At present, genetic parameters of the aforementioned traits have still not been studied in Qingyuan partridge chickens. The objectives of this study were the following: (1) to investigate whether the optimal statistical models of these traits need to consider maternal genetic and permanent environmental effects in late‐feathering Qingyuan partridge hens, and (2) to estimate genetic parameters for these traits based on the optimal models. The numbers of records for BW, SL, SG, CH and FM were 13,721, 13,671, 13,670, 13,669 and 13,672, respectively. Variance components were estimated using average information‐restricted maximum likelihood method, and the optimal model was determined based on Bayesian information criterion. More specifically, the optimal model for BW considered maternal genetic and permanent environmental effects in addition to direct additive genetic effect; SL, SG and FM considered direct and maternal genetic effects; and CH considered direct and maternal genetic effects, and the covariance between them. The direct heritabilities of these traits estimated using the optimal models were 0.21 ± 0.04, 0.30 ± 0.05, 0.40 ± 0.05, 0.59 ± 0.09 and 0.09 ± 0.04, respectively; the maternal heritabilities were 0.01 ± 0.04, 0.05 ± 0.05, 0.04 ± 0.05, 0.09 ± 0.09 and 0.03 ± 0.04, respectively. Maternal genetic effect evidently played an important part in FM and maternal heritability accounted for 30 per cent of total heritability. Furthermore, the direct and maternal genetic effects for CH were estimated to be negatively and moderately correlated (−0.51 ± 0.11). For all traits, neglecting existent maternal effects biased the estimation of direct heritability. Therefore, to implement optimum breeding strategies for improvement of these traits in Qingyuan partridge hens, maternal effects should be taken into consideration.
U.S. health insurance marketplace taxonomy and the influence of labeling on consumer perception of plan suitability
Authors: Hickey Christopher , Tharp Derek T.
Published: October 2020

This study investigates whether metal categories used in the health insurance marketplace established by the Affordable Care Act influence consumer choice in plan selection. Participants (N = 598) were randomly assigned to a marketplace environment containing either neutral terminology, metal categories, or descriptive labels. Respondents were asked to choose the most appropriate plan for low‐, average‐, and high‐use cases of health care consumption. Despite the bronze plan possessing the lowest estimated cost across each use case, the use of precious metal categories (compared to a neutral control) resulted in lower frequency selection of the gold plan in a low‐use case, higher frequency selection of the silver plan in an average‐use case, and higher frequency selection of the gold plan in a high‐use case. Furthermore, this study finds that beliefs equating more insurance with better health care and normative beliefs regarding the relationship between income and insurance are important predictors of plan selection.
Acquisition mode and credit card overspending behavior: An empirical analysis of the credit card industry
Authors: Ming Yaxin , Li Chenxi , Chen Jing (Elaine)
Published: October 2020

Although credit card overspending behavior has become a critical societal concern with severe negative impacts on consumer welfare and economic stability, research on credit card overspending behavior remains fragmented and understudied. This study investigates new types of antecedents of credit card overspending behavior that are overlooked in the prior literature—the acquisition mode of credit card companies. Based on data set from a large commercial bank in China, this study measures credit card overspending behavior using consumption amount, cash withdrawal amount and overdueness, and suggests that gift acquisition has a positive effect on cash withdrawal amount and overdue probability as well as a negative effect on consumption amount. Furthermore, we find that this relationship could be weakened for female customers and for customers with higher education levels. This study provides theoretical implications for both the credit card overspending literature and customer acquisition literature. It also has important implications for consumer welfare and public policymaking.
The work environment of haemodialysis nurses and its mediating role in burnout
Authors: Moisoglou Ioannis , Yfantis Aris , Tsiouma Erasmia , Galanis Petros
Published: October 2020

Background

The work environment can contribute to the occurrence of nurses' burnout.

Objectives

This study assessed the work environment of haemodialysis nurses and the extent of burnout they have suffered, and it explored the connection between work environment and burnout.

Design

A multicentre cross‐sectional study was conducted in 53 public, hospital‐based haemodialysis units in Greece.

Participants

A total of 537 haemodialysis nurses participated. The majority consisted of females (90.8%) who possessed a university degree or a degree from a technological institute (72.6%). They had an average of 15 years of experience in dialysis.

Measurements

The Practice Environment Scale of the Nursing Work Index and the Copenhagen Burnout Inventory (CBI) were used. The demographic characteristics of the participants were also collected.

Results

Although the nurses rated their work environment as healthy, they were experiencing a moderate degree of burnout. The multivariate linear regression analysis with the CBI scales as dependent variables was applied. The increased nurses' participation in hospital affairs was associated with decreased personal (coefficient β = −9.4, 95% confidence interval [CI] = −17.4 to −1.3, p = 0.023), work‐related (coefficient β = −12.9, 95% CI = −22.5 to −3.5, p = 0.008) and patient‐related burnout (coefficient β = −15.9, 95% CI = −24.5 to −7.4, p = < 0.001). The better collegial nurse–physician relationships were associated with decreased personal (coefficient β = −10.7, 95% CI = −18.3 to −3.0, p = .007) and work‐related burnout (coefficient β = −15.1, 95% CI = −23.3 to −7.0, p =  < 0.001).

Conclusions

The work environment of haemodialysis nurses was associated with burnout. Its improvement is an important tool in administrations' effort to ensure the nursing staff's well‐being.
Endozoochory of the same community of plants lacking fleshy fruits by storks and gulls
Authors: Martín‐Vélez Víctor , Lovas‐Kiss Ádám , Sánchez Marta I , Green Andy J
Published: October 2020

Aims

Research into the dispersal of plants lacking a fleshy fruit by avian endozoochory remains limited, particularly regarding the different roles of specific vectors in the same habitat.

Methods

We compared plants dispersed by endozoochory between two migratory waterbirds differing in body size: the lesser black‐backed gull Larus fuscus, and the white stork Ciconia ciconia. We collected faeces and pellets from roosting flocks on dykes in rice fields in Doñana, SW Spain, and extracted intact seeds.

Results

We recovered 424 intact seeds from excreta, representing 21 plant taxa, 11 of which germinated under laboratory conditions. Eight plant species are considered weeds, four of them as alien species, and only two have a fleshy fruit. Seed abundance and species richness per sample did not differ between storks and gulls. Toadrush (Juncus bufonius) was the dominant species, accounting for 49% of seeds recovered. PERMANOVA and mvabund analyses revealed no differences in the proportions of each plant species dispersed by the two vectors, and seasonal variation in abundance was absent. Overall, germinability was 19%, and declined with increasing delay between sample collection and processing. Transects along dykes identified 52 plant taxa, only 18 of which were recorded in excreta.

Conclusions

Overlap in the communities of non‐fleshy‐fruited plants dispersed by two unrelated birds of different size suggests that waterbird plant dispersal networks are different from frugivore networks. Unlike for frugivores, decoupling between seed production and ingestion reduces seasonal variation in endozoochory rates. For Juncus bufonius and other plants, these avian vectors provide maximum dispersal distances several orders of magnitude greater than predicted from their dispersal syndromes. Endozoochory by migratory waterbirds has major implications for plant distributions in a rapidly changing world, and more research is required before we can predict which plants disperse regularly via this mechanism.
Zooming on dynamics of marine microbial communities in the phycosphere of Akashiwo sanguinea (Dinophyta) blooms
Authors: Kang Junsu , Park Joon Sang , Jung Seung Won , Kim Hyun‐Jung , Joo Hyoung Min , Kang Donhyug , Seo Hyojeong , Kim Sunju , Jang Min‐Chul , Lee Kyun‐Woo , Jin Oh Seok , Lee Sukchan , Lee Taek‐Kyun
Published: October 2020

Characterizing ecological relationships between viruses, bacteria and phytoplankton in the ocean is critical to understanding the ecosystem; however, these relationships are infrequently investigated together. To understand the dynamics of microbial communities and environmental factors in harmful algal blooms (HABs), we examined the environmental factors and microbial communities during Akashiwo sanguinea HABs in the Jangmok coastal waters of South Korea by metagenomics. Specific bacterial species showed complex synergistic and antagonistic relationships with the A. sanguinea bloom. The endoparasitic dinoflagellate Amoebophrya sp. 1 controlled the bloom dynamics and correlated with HAB decline. Among nucleocytoplasmic large DNA viruses (NCLDVs), two Pandoraviruses and six Phycodnaviruses were strongly and positively correlated with the HABs. Operational taxonomic units of microbial communities and environmental factors associated with A. sanguinea were visualized by network analysis: A. sanguinea–Amoebophrya sp. 1 (r = .59, time lag: 2 days) and A. sanguinea–Ectocarpus siliculosus virus 1 in Phycodnaviridae (0.50, 4 days) relationships showed close associations. The relationship between A. sanguinea and dissolved inorganic phosphorus relationship also showed a very close correlation (0.74, 0 day). Microbial communities and the environment changed dynamically during the A. sanguinea bloom, and the rapid turnover of microorganisms responded to ecological interactions. A. sanguinea bloom dramatically changes the environments by exuding dissolved carbohydrates via autotrophic processes, followed by changes in microbial communities involving host‐specific viruses, bacteria and parasitoids. Thus, the microbial communities in HAB are composed of various organisms that interact in a complex manner.
Plastidial transporters KEA1 and KEA2 at the inner envelope membrane adjust stromal pH in the dark
Authors: Aranda Sicilia María Nieves , Sánchez Romero María Elena , Rodríguez Rosales María Pilar , Venema Kees
Published: October 2020

Photosynthesis and carbon fixation depend critically on the regulation of pH in chloroplast compartments in the daylight and at night. While it is established that an alkaline stroma is required for carbon fixation, it is not known how alkaline stromal pH is formed, maintained or regulated.

We tested whether two envelope transporters, AtKEA1 and AtKEA2, directly affected stromal pH in isolated Arabidopsis chloroplasts using the fluorescent probe 2ʹ,7ʹ‐bis‐(2‐carboxyethyl)‐5‐(and‐6)‐carboxyfluorescein (BCECF).

External K+‐induced alkalinization of the stroma was observed in chloroplasts from wild‐type (WT) plants but not from kea1kea2 mutants, suggesting that KEA1 and KEA2 mediate K+ uptake/H+ loss to modulate stromal pH. While light‐stimulated alkalinization of the stroma was independent of KEA1 and KEA2, the rate of decay to neutral pH in the dark is delayed in kea1kea2 mutants. However, the dark‐induced loss of a pH gradient across the thylakoid membrane was similar in WT and mutant chloroplasts.

This indicates that proton influx from the cytosol mediated by envelope K+/H+ antiporters contributes to adjustment of stromal pH upon light to dark transitions.
Assessing person‐centred care: An item response theory approach
Authors: Kazemi Ali , Kajonius Petri
Published: October 2020

Background and Objectives

Given recent advances in psychometric assessment, there is a need for assessment studies using modern test theory in the field of person‐centred care, mainly due to the dominant use of analytical strategies based on classical test theory. The main objective of the present study was thus to examine whether selected items from commonly used instruments of person‐centred care were able to differentiate between respondents with a reasonably even level of measurement precision across different regions of the construct range using item response theory (IRT).

Research Design and Methods

A Swedish sample of care staff in elderly care (N = 1342) completed a survey including a selection of items from three previously validated measures of person‐centred care.

Results

All questionnaire items were submitted to IRT analyses to examine the extent to which the items produced information on the underlying construct. The items exhibited different levels of information. However, in general, for those items exhibiting some information, the pattern of information across the trait range was similar for most of them, that is, the items discriminated better in the lower levels of person‐centredness.

Discussion and Implications

Item response theory analyses are instrumental in creating shorter measurement instruments that may perform nearly as well as the original longer instruments. Given time and other resource constraints in questionnaire administration, there is a gain in only including the most informative items which efficiently and evenly tap the underlying construct along its entire range and in the context of person‐centred care assessment this study was an initial step towards this goal. Thus, a set of ten items with satisfactory levels of psychometric quality, that is relatively high information levels across a relatively broad range of the underlying construct, is proposed.
Modulation of physiological performance by temperature and salinity in the sugar kelp Saccharina latissima
Authors: Monteiro Cátia , Li Huiru , Diehl Nora , Collén Jonas , Heinrich Sandra , Bischof Kai , Bartsch Inka
Published: October 2020

The sugar kelp Saccharina latissima experiences a wide range of environmental conditions along its geographical and vertical distribution range. Temperature and salinity are two critical drivers influencing growth, photosynthesis and biochemical composition. Moreover, interactive effects might modify the results described for single effects. In shallow water coastal systems, exposure to rising temperatures and low salinity are expected as consequence of global warming, increased precipitation and coastal run‐off. To understand the acclimation mechanisms of S. latissima to changes in temperature and salinity and their interactions, we performed a mechanistic laboratory experiment in which juvenile sporophytes from Brittany, France were exposed to a combination of three temperatures (0, 8 and 15°C) and two salinity levels (20 and 30 psu (practical salinity units)). After a temperature acclimation of 7 days, sporophytes were exposed to low salinity (20 psu) for a period of 11 days. Growth, and maximal quantum yield of photosystem II (Fv/Fm), pigments, mannitol content and C:N ratio were measured over time. We report for the first time in S. latissima a fivefold increase in the osmolyte mannitol in response to low temperature (0°C) compared to 8 and 15°C that may have ecological and economic implications. Low temperatures significantly affected all parameters, mostly in a negative way. Chlorophyll a, the accessory pigment pool, growth and Fv/Fm were significantly lower at 0°C, while the de‐epoxidation state of the xanthophyll cycle was increased at both 0 and 8°C compared to 15°C. Mannitol content and growth decreased with decreased salinity; in contrast, pigment content and Fv/Fm were to a large extent irresponsive to salinity. In comparison to S. latissima originating from an Arctic population, despite some reported differences, this study reveals a remarkably similar impact of temperature and salinity variation, reflecting the large degree of adaptability in this species.
Agricultural land partitioning model based on irrigation efficiency using a multi‐objective artificial bee colony algorithm
Authors: Bijandi Mehrdad , Karimi Mohammad , Farhadi Bansouleh Bahman , van der Knaap Wim
Published: October 2020

In the process of agricultural land consolidation, the land parcels are optimally redesigned and rearranged in such a way that the dimensions of the resulting parcels are proportional to agricultural criteria such as irrigation discharge, soil texture, and cropping pattern. Besides these criteria, spatial factors like slope, road accessibility, volume of earthwork, and geometrical factors such as size and shape of parcels are also included in the design process of agricultural land partitioning. In this study, a land partitioning model was proposed using a multi‐objective artificial bee colony algorithm (MOABC‐LP) taking into consideration the mentioned factors. Initially, a feasible dimension range of parcels in a block was calculated based on irrigation efficiency. Two partitioning layouts were defined according to the topography and geometry of blocks. The proposed method was applied to a real study area and the results suggest that the land partitioning plan obtained by the MOABC‐LP model, in comparison with a designer's plan, not only makes the shape and size of parcels more compatible with the topographical and agricultural conditions of each block, but also reduces their cut‐and‐fill ratio.
“Chike’s School Days”: An Autrebiography Verbalizing Chinua Achebe’s Early Schooling
Authors: Casimir Komenan
Published: October 2020

Todorov’s syntactic, verbal and semantic aspects of the literary text, onomastics and Mauron’s psychocriticism, underlie this paper whose goal is to show that Chinua Achebe’s “Chike’s School Days” is an autrebiography verbalizing Achebe’s early schooling. As two major thematic Ariadne’s threads, the religious, familial and onomastic connections between Chike and Achebe, as well as Achebe’s untimely love for Shakespeare’s language, have been used to compose an autrebiograhical short story, a shortened fiction about the self, which is narrated not in the first-person (“I”), but rather in the third-person (“He”). It is with such a detachment device that Achebe writes about Chike, a character who is nobody else but his double.
Microstructure and Oxidation Behavior of Narrow Gap Brazing and Wide Gap Brazing Joints With Boron/Silicon-Free Nickel Base Braze Alloys
Authors: Huang Xiao
Published: October 2020

In this study, the microstructure and solidus and liquidus of several Ni-Co-Hf-Zr-Ti-Al braze alloys were first examined with the objective to develop a B- and Si-free low-melting braze alloy for narrow gap (NGB) and wide gap brazing (WGB) and turbine component repair applications. Among various alloys examined, differential scanning calorimetry (DSC) was used to measure the solidus and liquidus during heating and cooling cycles. Following the measurements of liquidus and solidus, the microstructure was evaluated using SEM. Equations for calculating solidus and liquidus based on alloy's compositions were established, and the functions of each elements on these two characteristic temperatures were discussed. One selected alloy with a liquidus of 1201 °C was further employed for NGB and WGB experiments. The results showed that it was able join Cannon Muskegon single crystal (CMSX)-4 at 1240 °C without interfacial voids, and with the use of externally applied pressure and extended homogenization treatment, the interfacial intermetallic compounds were substantially removed. Furthermore, the same braze alloy was used to fill a large artificial cavity in a WGB scheme at a reduced temperature of 1200 °C. The braze alloy was able to fully bond the filler powder alloy in addition to join the two alloys to an IN 738 substrate. Finally, oxidation test was conducted at 1050 °C (isothermal in static air) for 100 h after NGB of CMSX-4 and WGB of IN 738. The results showed that the oxide formed on the standalone braze alloy is very dense and there is no sign of spallation. It contained primarily NiO (+CoO) with no other elements measured. For the NGB joints, large amount of scale spallation was observed on base alloy CMSX-4 while the NGB joint remained spallation free. The oxide formed on the NGB was NiO with partitions of Co, Al, Ti, Cr, and W. The WGB joint region in IN 738 showed oxide scale spallation on the IN 738 substrate side, leaving behind steps and depression on the sample surface. In the WGB joint itself, there were three notable phases after oxidation test; however, no scale spallation could be found. For the majority part of the surface, a Ni-rich oxide covered the surface. There were areas of smaller oxide particles with higher Cr content. Overall, the new boron/silicon-free braze alloy was found to be able to join several superalloys in both WGB and NGB schemes without occurrence of defects and the oxidation resistance was superior to both substrate alloys examined in this study.
Erosion Prediction of Sub-Sea Xmas Tree Based on CFD
Authors: Rong Xin , Zhu Hongwu
Published: October 2020

Sub-sea vertical Xmas tree is one of the key equipment in the oil industry. Erosion caused by particles in the flow of oil and gas may lead to equipment failure or even interruption of oil exploitation. Therefore, it is important to figure out the characteristics of erosion in vertical Xmas tree. In the present work, the AISI 8630 erosion model and the Forder wall rebound model has been applied to study the erosion of production channel and choke valve in the tree. The maximum and average surface erosion amount are introduced to evaluate the erosion degree. The results show that for the production channel, erosion mainly occurs in the interior of the turning point of the channel and the interior of the downstream wall near the joint, and the most serious eroded area is located at the bottom of the downstream wall of the channel. Comparing the effects of blind pipe length, particle concentration, particle size and flow velocity on the erosion wear of the production channel, it is found that the flow velocity is the main factor affecting erosion. As the velocity of fluid increases, the maximum and the average surface erosion on the inner wall of production channel increase in a steep manner. For the choke valve, as the relative opening increases, the maximum erosion amount decreases sharply. However, compared with the production channel, the wear of the valve channel is much more serious, and more attention should be paid in industrial operations.
Pump Specific Speed and Four Quadrant Data in Waterhammer Simulation: Taking Another Look
Authors: Walters Trey , Dahl Trygve , Rogers David C.
Published: October 2020

In some situations, it is possible for flow to go backwards through a pump during a transient waterhammer event. Sustained reverse flow will lead to reverse rotation. Understanding and predicting the pump behavior during waterhammer under these conditions is typically accomplished using previously published four quadrant pump data. Historically, the selection of which data to use is based on the similarity of pump specific speed. The weaknesses of using specific speed are described and an improved method of selecting appropriate four quadrant data is given based on fundamental curve shapes for head and power in the normal operating zone.
Modeling and Control of Real Flow Calibration System
Authors: Wen Kai
Published: October 2020

The calibration of large-diameter flow meters is performed in the calibration station where real flow passes through. The typical calibration process is manipulated by human operators, which is time-consuming and easily affected. Since most of the process parameters are detectable, the smart calibration system was aided by the on-line modeling process and consisted of three parts: the digital twin model, the process controller, and the human-machine interface (HMI). The digital twin model was based on the basic partial differential equations of the gas flow in pipelines and was meant for the flow behavior prediction over short periods and provided decision-making assistance for human operators. The verification of the digital model was based on both the historical process data and the real-time process data. The process controller represented the manipulator meant to replace the human operator. The function of the controller included process control and calibration flow point adjustment. The HMI was designed based on the industrial supervisory control and data acquisition (SCADA) system. Since the process control was essential, the scheduling scheme and command sequence feedback to the SCADA system was rechecked by human operators via the HMI. The result of the active control was displayed in the HMI based on the digital twin model.

Since smart control was the tendency in the piping system, the automated process verification and control formed the basis of the smart system. By entering the size and range of the flow meters into the HMI, the entire industrial system inside the calibration station was executed automatically.
Research on the Measurement Accuracy of Ultrasonic Phased Array Time-of-Flight Method
Authors: Liu Shu H. , Ding Ju , Wang Jie L.
Published: October 2020

In special public pipelines, High Density Polyethylene (HDPE) had been widely applied, making integrity and safety priority. In the periodic inspection of pressure vessel and pressure pipeline, the safety level shall be determined by the defect geometric size. Therefore, it is necessary to get the defect size data as accurately as possible.

Digital radiography inspection is a feasible method for detecting butt fusion welds. Defect size can be measured accurately by digital radiographic image. Due to factors such as damage to human body caused by ray, it is difficult to detect HDPE pipelines in some occasions in field. Ultrasonic phased array testing has high accuracy in flaw inspection, high efficiency and little artificial criteria error. But conventional phased array has difficulties in detecting butt fusion welds due to acoustic attenuation and noise affection.

In this paper, PE butt fusion welding is inspected by immersion phased array. The absolute time-of-flight method is used to measure the defect size, and the accuracy is qualified with the requirements of the butt fusion welding inspection. For more important, inspector does not need to move equipment probe, avoiding artificial errors and improving the efficiency.
Proposal of Use of Mises Criteria for Elastic Analysis in Appendix 9 of ASME Section VIII Division 3
Authors: Terada Susumu
Published: October 2020

The stress evaluation by elastic analyses for protection against plastic collapse in Appendix 9 is based on maximum shear stress theory (Tresca theory). On the other hand, the stress evaluation by elastic-plastic analysis and design equations by flow stress for design pressure for cylindrical shell and spherical shell in KD-221 is based on distortion energy yield stress theory (von Mises theory). With regard to materials with low and intermediate Sy/Su, in particular the primary stress evaluation based on Tresca stress for elastic analysis in current Div.3 is much more conservative than that based on flow stress equations similar to elastic-plastic analysis from experimental results. In Section VIII Div.2, von Mises yield criterion is used for stress evaluation for elastic analysis because it matches experimental results more closely than Tresca yielding criterion and is also consistent with plasticity algorithms used in elastic-plastic analysis. Therefore in Div.3 von Mises stress should be used for elastic analysis in the same way as in Sec. VIII Div.2. For materials with high Sy/Su, the primary stress evaluation based on von Mises criterion for elastic analysis is less conservative than that based on flow stress equations similar to elastic-plastic analysis because of a difference in design factor of 1.5 for elastic analysis and 1.732 for flow stress equations. Therefore, we propose using von Mises criterion for protection against plastic collapse with design correction factor using Sy/Su in Appendix 9 in order to remove excessive conservativeness for materials with low and intermediate Sy/Su. The validity of this proposal is shown in this paper.
The Research on the Stress Analysis of Overhead Steam Pipeline
Authors: Pu Zhe , Wang Jielu , Ren Bin , Song Pan , Zhao Fan
Published: October 2020

Industrial production is accompanied by a large number of physical and chemical reactions. Steam, whose heat was often used to carry out various production activities, is a common medium in industrial production. Steam pipeline has the characteristics of high temperature and high pressure. The pipeline has been in service at high temperature for a long time, which is prone to metal material degradation such as graphitization and spheroidization. Cause of the expansion of steam pipeline after heating, the natural compensation structure is generally adopted in the whole plant pipe gallery. In recent years, the accidents of steam pipeline occurred frequently, so we must pay more attention to the safety of steam pipeline. Periodic Inspection Regulation for Industrial Pressure Piping (TSG D7005-2018) explicitly requires stress analysis and checking in some cases to determine the safety of the pipeline. The traditional inspection method adopts a random sampling model which has the risk of over inspection and missing inspection. Taking a whole plant steam pipeline as an example, this paper introduced the stress check criterion of pipeline in ASMEB31.3.The model of the pipeline was established by the software, and the stress state and displacement of each node of the pipeline were calculated. According to the calculation results, a targeted inspection scheme was established and effective data support was provided for the regular inspection of steam pipeline.
Comparative Study on Seismic Response Analysis Methods of Spherical Tanks
Authors: Ma Zhongming , Xiao Guang , Zhang Minghui , Zhang Haijun , Du Ruixue
Published: October 2020

Spherical tank is an important storage equipment in petrochemical industry. It is often used to store inflammable and explosive materials. Once it is damaged in the earthquake, it will lead to serious consequences. In this paper, the finite element model of spherical tank is established by ANSYS software. The bottom shear method, mode decomposition method and time history analysis method are used to calculate the strength of spherical tank. The weakest link of the structure under the real earthquake load is determined, which provides the basis for the seismic safety guarantee and structural design of spherical tank. The applicability of the three calculation methods is compared and discussed.
Multiphase Flow Induced Vibrations at High Pressure
Authors: Belfroid S. P. C. , Gonzalez-Diez N. , Lunde K. , Orre S.
Published: October 2020

High pressure experiments were done to determine the pressure effect on multiphase induced forces. To that end, a series of water/gas, oil/gas and oil/water/gas vibrations measurements were performed at 10, 25, 45 and 80 bar at different liquid and gas rates in a horizontal, 2″, double Uloop test section installed at the Equinor Porsgrunn site. At higher pressures the vibration amplitude decreased inversely proportional to the pressure. This was measured for both oil and water. Based on the vibration data, the forcing spectrum was reconstructed. In this the same decreased trend was observed, indicating that a changed damping is not the cause of the reduced vibrations. In the forcing spectra the main effect was a higher energy content at lower frequencies. No clear shift in the peak frequency was measured.
Fracture Mechanics Assessment of Reactor Pressure Vessel Irradiated Structural Steel for Short Column Type Supports and Neutron Shield Tank
Authors: Carolan Alexandria M. , Hall J. Brian , Longwell Stephen K. , Alpan F. Arzu , Imbrogno Gregory M. , Udyawar Anees A. , Boggs Scott , Franzone Steve , Tomes Charles , Haluska Beth
Published: October 2020

As plants apply for 80 year licensure (subsequent license renewal), the United States Nuclear Regulatory Commission (U.S. NRC) has queried the nuclear power plant industry to investigate the impact of neutron embrittlement (radiation effects) on the reactor pressure vessel (RPV) structural steel supports due to extended plant operation past 60 years. The radiation effects on RPV supports were previously investigated and resolved as part of Generic Safety Issue No. 15 (GSI-15) in NUREG-0933 Revision 3 [1], NUREG-1509 [2] (published in May 1996), and NUREG/CR-5320 [3] (published in January 1989) for design life (40 years) and for first license renewal (20 additional years). The conclusions in NUREG-0933, Revision 3 stated that there were no structural integrity concerns for the RPV support structural steels; even if all the supports were totally removed (i.e. broken), the piping has acceptable margin to carry the load of the vessel. Nevertheless, for plants applying for 80 year life licensure, the U.S. NRC has requested an evaluation to show structural integrity of the RPV supports by accounting for radiation embrittlement (radiation damage) for continued operation into the second license renewal period (i.e. 80 years).

The RPV support designs in light water reactors are grouped into one of five categories or types of supports: (1) skirt; (2) long-column; (3) shield-tank; (4) short column; and (5) suspension. In this paper, two of these RPV support configurations (short column supports and neutron shield tank) will be investigated using fracture mechanics to evaluate the effect of radiation embrittlement of the structural steel supports for long term operations (i.e. 80 years). The technical evaluation of other support configurations will be provided in a separate technical publication at a future date.
Piping and Equipment Dynamics of High Rate HVGO Pumps
Authors: Kaye Alwyn
Published: October 2020

A set of Heavy Vacuum Gas Oil (HVGO) pumps in a 300 kbbl/day operating Upgrader Plant experienced repeated failures; typically less than 7 weeks. The pumps run continuously in a high-pressure, high temperature and corrosive environment and their functional status directly affects the reliability of the plant. Upon research, an experimental strain measurement technique using very high resolution laser digital imagery and optical metrology was found from military and advanced aerospace applications to verify high level dimensional accuracy of critical components [1]. Application to a complex and operating bitumen upgrader was unknown.

The objective of this project was to use advanced optical metrology with digital image processing techniques employing multiple laser and high-speed cameras capable of generating pump and pipe component’s real time strain images, displacement and rate of change. Optical metrology can analyze the mechanical properties and behavior of many materials and in various test scenarios [2]. Hot and cold operating service, with variations in flow and temperature all dynamically affect the strain measurements. Three significant advantages of the optical method are:

i. Avoids a host of problems of strain gauge application, wiring and setup.

ii. The problems of temperature sensitivity and correction are overcome. [3]

iii. Gathers much more extensive data than possible with traditional methods.

The vibration characteristics of the pumps and related hardware were analyzed using high resolution laser and photogrammetric digital imagery and digital strain mapping analysis to determine the characteristics that would ensure the long-term reliable and safe operation of the HVGO pumps. The stress and deformation analysis were performed on the operating pumps in a variety of normal (1280 m3/hr.) and upset operating conditions including under partial and full load conditions. Dynamic and modal analysis of the pumps was developed and analyzed. The displacement and tensor fields of the hardware including the pumps, bases and piping were measured using high resolution laser cameras and analyzed.

From the high-speed data gathering and loading analysis showed the deformation and stress affecting the pump and related hardware. The key variables undermining reliable performance were revealed and from the data the necessary remedial action was determined. The pumps have operated for over 30months to the time of writing without repeat failure.

This paper should be read in conjunction with PVP 2020-21203; Investigation and Resolution of the Fluid Structure Interaction of High Rate HVGO Pumps.
Dynamic Performance Analysis of Interfacial Cracks Near an Eccentric Elliptical Hole in Piezoelectric Bi-Materials Under Incident SH-Waves
Authors: An Ni , Song Tian-shu , Zhao Ming , Liu Yu , Hou Gangling
Published: October 2020

Piezoelectric materials have been widely used in modern science and technology due to their electro-mechanical coupling response. Sometimes, because of the stiff and brittle nature of some piezoelectric materials, the piezoelectric devices with defects may face fracture or failure during their service procedures. Therefore, it has become important to investigate the failure behaviors caused by defects, such as cracks and holes.

Based on the study of the dynamic anti-plane characteristics for radial crack emanating from a circular cavity in piezoelectric bi-materials, this paper aims to analyzes the dynamic incident anti-plane shearing (SH-wave) in piezoelectric bi-materials, which contains two interfacial cracks, near an eccentric elliptical hole. Green’s function method, the conformal mapping method, the interface conjunction techniques and the crack-deviation techniques are utilized to obtain a series of first kind Fredholm’s equations, based on which the dynamic stress intensity factor (DSIF) at the outer and the inner cracks’ tips are theoretically expressed. Numerical examples were graphically presented to illustrate the effects of the piezoelectric parameter, the effective piezoelectric elastic modulus, the dimensionless incident wave number and geometric parameters on the DSIF at both of the tips.

Previous studies are not comprehensive, especially when the center of the hole deviates from the interface. Therefore, the impact of eccentric distance on DSIF is considered in this paper. The solution of this problem provides a more accurate and efficient method for the investigation of dynamic fracture properties of piezoelectric materials and has an important theoretical significance in engineering design.
Structural Analysis Approach for the Defense Programs Package 3 (DPP-3)
Authors: Sakalaukus Peter J. , Barrett Nathan P. , Koeppel Brian J.
Published: October 2020

The Pacific Northwest National Laboratory (PNNL) is the design authority for a new Type B hazardous materials transportation package designated as the Defense Programs Package 3 (DPP-3) for the U.S. Department of Energy (DOE) National Nuclear Security Administration (NNSA). The DPP-3 has been developed using similar materials and fabrication methods employed in previous U.S. Nuclear Regulatory Commission (NRC), DOE, and NNSA certified packages. The DPP-3 design criteria are derived from the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (BPVC), NNSA guidance and NRC regulatory guides in order to safely and securely transport a variety of payloads. Final regulatory approval by the NNSA will require regulatory testing to demonstrate that the containment vessel (CV) remains leaktight after enduring the entire regulatory testing sequence prescribed in Title 10 of the Code of Federal Regulations Part 71 (10 CFR 71). In order to gain confidence that the DPP-3 will remain leaktight after testing, the DPP-3 has been structurally analyzed using the Finite Element Analysis (FEA) software LS-DYNA. The FEA analyses serve two general purposes: first, they aid in design and development of the package, and second, they advise as to which drop orientations are expected to cause the most damage during regulatory testing. This paper will discuss how the design criteria are incorporated into analytical techniques needed to evaluate the FEA structural simulation results for 10 CFR 71 conditions to give confidence the DPP-3 testing campaign will be successful.
Experimental Investigation on Burst Pressure and Fatigue Life of Type IV LPG Cylinders
Authors: Wen Ange , Shen Chuanchuan , Hao Chunyong , Zheng Jinyang
Published: October 2020

Compared with the steel cylinders for liquefied petroleum gas (LPG), fully-wrapped fiber reinforced cylinders with non-metallic liners (type IV cylinders) have been widely used due to their advantages of light weight, corrosion resistance, low maintenance cost and no explosion when exposed in fire. However, for the heterogeneity of raw material performances and instability of manufacturing process, the mechanical performances of type IV cylinders show a certain dispersion. Therefore, in this study, a series of burst tests and pressure cycle tests on 89 type IV LPG cylinders (26.2 L, 2.1 MPa) were conducted to examine the performances of burst pressure and number of pressure cycles, and analyze the distribution characteristics. The total length of the experimental cylinder was 465 mm, the outer diameter and the thickness of the liner was 304 mm and 2 mm, respectively. Two types of cylinders were tested, with the thickness of composite overwrap in 2 mm and 4 mm, corresponding to the designed burst pressure of 12 MPa and 15 MPa. Burst test and pressure cycle test were conducted according to the standard GB/T 15385 and GB/T 9252, respectively. Results showed that the 59 cylinders had the similar crevasses morphology along the axial wall of liners after burst tests. Burst pressure of two design types fluctuated within the range of 11.4 MPa-12.5 MPa, and 13.7 MPa-16.0 MPa, respectively. The statistical results of burst pressure showed approximately normal distribution with a standard deviation of 0.263 MPa and 0.529 MPa. Also, the number of pressure cycles of 30 cylinders were all above 12,000 with a cycle frequency no more than 15 cycles per minute. Above studies have provided a data support for the recently published Chinese association standard T/CATSI 02 003-2019.
Two-Dimensional Geometrically Nonlinear Finite Element Formulation for Analysis of Straight Pipes
Authors: Attia Saher , Mohareb Magdi , Martens Michael , Yoosef Ghodsi Nader , Li Yong , Adeeb Samer
Published: October 2020

The paper presents a new and simple geometrically nonlinear finite element formulation to simulate the structural response of straight pipes under in-plane loading and/or internal pressure. The formulation employs the Green-Lagrange strain tensor to capture finite deformation-small strain effects. Additionally, the First Piola-Kirchhoff stress tensor and Saint Venant-Kirchhoff constitutive model are adopted within the principle of virtual work framework in conjunction with a total Lagrangian approach. The formulation is applied for a cantilever beam under three loading conditions. Results are in good agreement with shell models in ABAQUS. Although the solution is based on a single element, the formulation provides reasonable displacement and stress predictions.
Examination of the Transferability of CTOA From Small-Scale DWTT to Full-Scale Pipe Geometries Using a Cohesive Zone Model
Authors: Bassindale Chris , Wang Xin , Tyson William R. , Xu Su
Published: October 2020

In this work, the cohesive zone model (CZM) was used to examine the transferability of the crack tip opening angle (CTOA) from small-scale to full-scale geometries. The pipe steel STPG370 was modeled. A drop-weight tear test (DWTT) model and pipe model were studied using the finite element code ABAQUS 2017x. The cohesive zone model was used to simulate crack propagation in 3D. The CZM parameters were calibrated based on matching the surface CTOA measured from a DWTT finite element model to the surface CTOA measured from the experimental DWTT specimen. The mid-thickness CTOA of the DWTT model was in good agreement with the experimental value determined from E3039 and the University of Tokyo group’s load-displacement data. The CZM parameters were then applied to the pipe model. The internal pressure distribution and decay during the pipe fracture process was modeled using the experimental data and implemented through a user-subroutine (VDLOAD). The mid-thickness CTOA from the DWTT model was similar to the mid-thickness CTOA from the pipe model. The average surface CTOA of the pipe model was in good agreement with the average experimental value. The results give confidence in the transferability of the CTOA between small-scale specimens and full-scale pipe.
Frequency Dependency of Beam Collapse due to Vibration Loads
Authors: Sasaki Ryunosuke , Ichimiya Masakazu , Lyu Jinqi , Kasahara Naoto
Published: October 2020

Since the accident at the Fukushima Daiichi power plant, in addition to “design to prevent accidents”, “mitigating the severe accident” has come to be emphasized. Thus, it is necessary to evaluate the actual failure mode under beyond design basis events (BDBEs). In this study, authors focus on the failure mode of piping in nuclear power plants under excessive earthquakes. The piping design of nuclear power plants has been conservative assuming that seismic load acts as load-controlled and the collapse happens by maximum acceleration. However, the test conducted by Electric Power Research Institute (EPRI) confirmed that when excessive vibration load was applied to the piping with the elbow, ratchet deformation occurred with time and eventually collapsed. Unfortunately, this failure mechanism is not clear, so it is highly important to consider the actual failure mode, namely ratchet deformation leading to collapse. Authors tried to clarify the mechanism of ratchet deformation by experiments and analyses of inputting acceleration to a beam simulating piping. According to these results, it is identified that ratchet deformation is likely to occur when the vibration load whose frequency is lower than resonance frequency is applied, and is difficult to occur on the higher frequency area. Hereafter, the ratio of the frequency of vibration load to the natural frequency of beams is referred as “frequency ratio”. In this study, half-cycle vibration load was applied to the beam, and the frequency dependence of the collapse phenomenon was investigated.