scholarly journals Simultaneous Verification of Multi-Ultrasonic-Flowmeters in Tandem Arrangement for Natural Gas

2019 ◽  
Vol 9 (17) ◽  
pp. 3632
Author(s):  
Tingyang Hong ◽  
Meng Yang ◽  
Chengxu Tu ◽  
Qipeng Huang ◽  
Fubing Bao ◽  
...  
Keyword(s):  
Natural Gas ◽  
Internal Flow ◽  
The Other ◽  
Striking Difference ◽  
Relative Measurement ◽  
Comparison Analysis ◽  
Tandem Arrangement ◽  
Relative Measurement Error ◽  
Actual Flow ◽  
Flow Experiments

A combined experiment and numerical analysis was performed to determine whether the flow field has a significant impact on the simultaneous verification of multi-ultrasonic flowmeters (UFMs) in tandem arrangement (SVUFMST) and whether the SVUFMST is practical for flowrate measurement of pressurized natural gas. In practical testing, SVUFMST can highly improve the efficiency of UFMs’ calibration. Two types of UFMs of different nominal diameter were studied: DN250 and DN150. When it comes to DN250, data obtained from the actual-flow experiments were first used to verify the simulated results for n ≤ 3 (number of tested UFMs) and then the verified numerical method was extended to simulate the internal flow of four and five tested UFMs. Comparison analysis shows that all the numerical results agree remarkably well with the available experimental data and more than two tested UFMs can induce an overall shift in the E–Q curve (relative measurement error E plotted as a function of flowrate Q). For the slight difference among the tested UFMs, the practicability of the SVUFMST at n ≤ 4 (DN250) and n ≤ 3 (DN150) are thereby proved, whereas the striking difference in E (~1.0%) between the most downstream UFM and the other UFMs for n = 5 (DN250), associated with the outstanding collapse onto the velocity profile along the acoustic paths, results in the invalidation of the SVUFMST.

Deutsch als schwächere Sprache bei deutsch-polnisch bilingualen Kindern: Studie zur Negation- und Verbstellung

2020 ◽  
Vol 48 (2) ◽  
pp. 269-297
Author(s):  
Aldona Sopata ◽  
Kamil Długosz
Keyword(s):  
Second Language Acquisition ◽  
Language Development ◽  
Language Use ◽  
The Other ◽  
Bilingual Children ◽  
Striking Difference ◽  
Final Position ◽  
Development Characteristic ◽  
Processing Mechanisms ◽  
Constrained Input

AbstractThis article examines the acquisition of German as the weaker language in the cases of German-Polish bilingual children. Focusing on negation and verb position, phenomena that have frequently been taken as diagnostic when distinguishing between the course of language development characteristic for first (L1) and second language acquisition (L2), we analyse experimental and productive data from six simultaneously bilingual children. Due to the constrained input, German is their weaker language. The results in Forced Choice and Grammaticality Judgements tasks are compared with the results of monolingual children. We show that in the area of negation the acquisition of German as the weaker language resembles L1, and in the area of inversion and verb final position the development of the weaker language is delayed. The striking difference between bilinguals’ results in the experimental vs. productive tasks points to specific processing mechanisms in bilingual language use. In narrative contexts of the production tasks the language of the performance is activated, while the other is inhibited, which leads to a target-like performance. Structural properties of the stronger language tend to be activated, however, in the experimental tasks involving the weaker language, resulting in non-target-like responses.

Top three LNG buyers to search for alternative LNG pricing structure after paying a total cost premium of $56 billion for oil-indexed LNG contracts in 2019 and 2020 – how will this affect Australia as the number one supplier to this market?

2021 ◽  
Vol 61 (2) ◽  
pp. 412
Author(s):  
Sindre Knutsson
Keyword(s):  
Natural Gas ◽  
South Korea ◽  
Spot Market ◽  
Liquefied Natural Gas ◽  
The Other ◽  
Future Market ◽  
Total Cost ◽  
The Future

Increasing spreads between spot liquefied natural gas (LNG) and oil-indexed contracts have resulted in the world’s top three LNG buyers paying a cost premium of $33 billion in 2019 and 23 billion in 2020. The top three buyers are Japan, China and South Korea, which had a combined 151Mt of long-term LNG contracts indexed to oil in 2020. This cost premium shows what top Asian buyers are currently paying for the security of LNG supply through long-term oil-indexed contracts. However, it also shows the potential reward Asian buyers have if they manage to develop a liquid LNG pricing hub in Asia to which they can index their contracts. Japanese buyers’ efforts of increasing flexibility in contracts, both through take-or-pay agreements and destination flexibility and aims of growing the spot market, will increasingly support the liquidity of the LNG market. However, there will be resistance from the other side of the table, for where someone is paying a premium, or making a loss, someone is making money. 2020 was another year of plenty for LNG producers selling oil-indexed volumes to Asian markets. Australia is the largest seller of LNG to Japan, China and South Korea with over 60Mt of long-term LNG contracts indexed to oil in 2020. Australia has benefited from having their contracts indexed to oil, but what’s next? In this paper, Rystad Energy will discuss the future market for Australian LNG exports including development in LNG demand, contract trends and price spreads.

A Note Related to the Pressure Inside an Inflating Parachute Canopy

1977 ◽  
Vol 28 (4) ◽  
pp. 271-277
Author(s):  
P R Payne ◽  
E G U Band
Keyword(s):  
Analytic Function ◽  
Stream Flow ◽  
Free Stream ◽  
Internal Flow ◽  
The Other ◽  
Virtual Mass ◽  
Ram Pressure ◽  
Parachute Canopy ◽  
Mass Terms ◽  
Internal Pressures

SummaryIf a canopy is idealised as a cylinder with one end open to the free-stream flow, and the other end closed, then the internal flow during inflation is given by a simple analytic function. In this note the function is derived and then the internal pressures and corresponding forces associated with inflation are determined. It is found that, in addition to ram pressure and the von Kármán “virtual mass” terms in the pressure equations, there are other transient terms associated with radial velocity and acceleration.

Cooperation and Competitive Goals: A Social-Comparison Analysis

1974 ◽  
Vol 34 (3) ◽  
pp. 887-894 ◽  
Author(s):  
Steven P. McNeel ◽  
James D. Sweeney ◽  
Peter C. Bohlin
Keyword(s):  
Social Comparison ◽  
Goal Orientation ◽  
Choice Behavior ◽  
Prisoner’S Dilemma ◽  
Social Comparisons ◽  
The Other ◽  
Comparison Analysis ◽  
Relative Gain ◽  
Competitive Outcomes ◽  
Average Condition

Ss' choice behavior in two types of mixed-motive games was used to classify them according to their predominant goal orientation. Ss with competitive (Relative Gain) goals and those with individualistic (Own Gain) goals were then presented with 50 decomposed Prisoner's Dilemma games in which they interacted with a conditionally cooperative other. Some Ss saw their own and the other person's outcomes displayed on each trial, while others also saw a bogus Average outcome. The latter outcome was constructed such that comparison with it made the mutually competitive outcomes “look bad” and the mutually cooperative outcomes “look good.” On the basis of social-comparisons, it was predicted that Relative-gain Ss would learn to cooperate in the “Average” condition but not in the Other condition. Own-gain Ss were expected to show high levels of cooperation over-all and to cooperate sooner in the Average condition than in the Other condition. Predictions were significant only for Own-gain Ss, though they were also in the expected direction for Relative-gain Ss. The discussion focused on problems with using social-comparison processes as a basis for training Ss to be cooperative, with special emphasis placed on the issue of the relevance of the available comparisons.

Guidelines for Production of API Pipelines Steels Suitable for Hydrogen Induced Cracking (HIC) Service Applications

2010 ◽  
Author(s):  
Douglas G. Stalheim ◽  
Bernhard Hoh
Keyword(s):  
Mechanical Property ◽  
Natural Gas ◽  
Pipeline Steel ◽  
Steel Production ◽  
The Other ◽  
Corrosion Mechanism ◽  
Pipeline Steels ◽  
Hydrogen Induced Cracking ◽  
Oil And Natural Gas ◽  
Sour Service

Worldwide oil and natural gas reserves can be classified as either sweet or sour service. The sour service classified oil and natural gas reserves contain some level of H2S making the product flowing through a steel pipeline corrosive. Due to this, the majority of the oil and natural gas reserves that have been drilled are of the sweet service nature. However as demand continues and supplies change, many of the remaining oil and natural gas reserves contain the H2S component and are of a sour service nature. These oil and natural gas reserves containing the H2S component through a corrosion mechanism will allow for diatomic hydrogen — in the presence of moisture — to disseminate to monatomic hydrogen and diffuse into the pipeline steel microstructure. Depending on the microstructure and level of cleanliness the monatomic hydrogen can become trapped at areas of high residual stress, recollect to diatomic hydrogen and creating partial pressures that exceed the tensile strength of the steel resulting in cracking. Therefore transmission pipelines are being built to transport sour service oil or natural gas requires steels with hydrogen induced cracking (HIC) resistance. Alloy designs, steel making processing, continuous casting, plate or strip rolling, pipe forming, and last not least corrosion testing are all key components in producing pipeline steels that are resistant to HIC applications and meeting the NACE TM0284 specifications. However, producing steels that have good HIC performance do not necessarily meet other mechanical property requirements such as strength and YT ratios. Balance has to be achieved to meet not only the HIC requirements but the other required mechanical properties. Mastering this complex HIC process poses a serious challenge to pipe producers and their primary material suppliers. The capability of producing HIC steel grades according to critical specifications and/or standards clearly distinguishes excellent steel producers from good steel makers. This paper will discuss the basics of the hydrogen induced cracking phenomenon, the requirements of the NACE TM0284 specification and give guidelines for steel production of API pipeline steels that not only can meet the specification requirements the NACE testing but also fulfill the other mechanical property requirements.

The decoupling states of CO2 emissions in the Chinese transport sector from 1994 to 2012: A perspective on fuel types

2018 ◽  
Vol 29 (4) ◽  
pp. 591-612 ◽  
Author(s):  
Dayong Wu ◽  
Changwei Yuan ◽  
Hongchao Liu
Keyword(s):  
Natural Gas ◽  
Sustainable Transportation ◽  
Policy Implications ◽  
The Other ◽  
Fuel Oil ◽  
Transport Sector ◽  
Aggregate Level ◽  
Heavy Fuel Oil ◽  
Negative State ◽  
Oil And Natural Gas

This paper analyzes the decoupling states between CO2 emissions and transport development in China from 1994 to 2012. The results indicate that, at the aggregate level, the Chinese transport sector is far from reaching the decoupling state. Negative decoupling or non-decoupling years account for 72.2% of the study period. At the disaggregated level, the decoupling states between CO2 emissions and eight primary fuels are as follows: raw coal and coke are in the absolute decoupling state; crude oil, gasoline and diesel are in the weak negative state; and the other three types (kerosene, heavy fuel oil, and natural gas) are in the strong negative decoupling state. Policy implications underneath the identified decoupling states are also revealed to help China build a more sustainable transportation system.

scholarly journals Can the Planck Length Be Found Independent of Big G?

2017 ◽  
Vol 9 (6) ◽  
pp. 58 ◽  
Author(s):  
Espen Gaarder Haug
Keyword(s):  
Measurement Error ◽  
Particle Accelerators ◽  
Relative Measurement ◽  
Planck Length ◽  
Relative Measurement Error ◽  
Set Up

In this paper we show how it is possible to measure the Planck length through a series of different methods. One of these measurements is totally independent of big G, but moving from the theoretical realm to the empirical realm would require particle accelerators far more powerful than the ones that we have today. However, a Cavendish-style experiment can also be performed to find the Planck length with no knowledge of the value of big G. Furthermore, the Cavendish style set-up gives half of the relative measurement error in the Planck length compared to the measurement error in big G.

A Conjoint Analysis of Five Factors Influencing Heavy Vehicle Drivers Perceptions of Workload

1995 ◽  
Vol 39 (17) ◽  
pp. 1102-1106 ◽  
Author(s):  
Thomas E. Nygren
Keyword(s):  
Conjoint Analysis ◽  
The Other ◽  
Traffic Density ◽  
Heavy Vehicle ◽  
Comparison Analysis ◽  
Scaling Technique ◽  
Factors Influencing ◽  
Five Factors ◽  
Perceived Workload ◽  
Conjoint Scaling

Conjoint analysis, a multi-factor subjective scaling technique, was used in a study of heavy vehicle drivers to obtain a measure of their perceived workload demands under different driving conditions. These included combinations of low and high levels of traffic density, lighting, roadway type, visibility, and traction. A tradeoff comparison analysis was used to collect the conjoint scaling data from a subset of the complete 2−2−2−2−2 design. Results indicated that an additive factor representation fit the data very well, but that the five factors had very different importance weights. The drivers’ orderings of perceived demand appeared to be inversely related to their control over the conditions. The two most important factors (traction and visibility) are effectively environmental factors that cannot be easily controlled by the driver. The other three factors (traffic density, highway type, and lighting) can, at least to some extent, come under the control of the driver. Implications of these results and the use of conjoint scaling methodology are discussed.

US tensions prompt closer China-Russia cooperation

2019 ◽  
Keyword(s):  
Natural Gas ◽  
Consumer Goods ◽  
The Other ◽  
High Tech ◽  
Content Type ◽  
Economic Relations ◽  
Economic Interaction ◽  
Economic Ties ◽  
The Eu

Subject China-Russia cooperation. Significance Beijing and Moscow are compensating for deteriorating ties with Washington by building -- or at least declaring -- close political and economic relations with each other. Chinese exporters of production and consumer goods are replacing Western companies that are curtailing activities due to Western sanctions and Moscow’s countersanctions. However, neither Beijing nor Moscow sees the other as a true substitute for normal relations with Washington. Impacts China and Russia will more actively use the renminbi and ruble as settlement currencies. Russia will preserve its position as China’s key supplier of oil and will significantly expand deliveries of natural gas. Russia will press for closer ties in high-tech industries; China will be wary, fearing this might prompt new US sanctions. The epicentre of Russia’s foreign economic ties will shift further from the EU to China. Greater economic interaction with Russia will help China cement its relations with other former Soviet countries.

CFD Analysis of the Effect of Rolling Motion on the Characteristic of Labyrinth Seal

2017 ◽  
Author(s):  
Ning Huang ◽  
Zhenlin Li ◽  
Shiyao Li ◽  
Ning Zhang ◽  
Zhihui Dong
Keyword(s):  
Pressure Drop ◽  
Natural Gas ◽  
Performance Characteristic ◽  
Oil And Gas ◽  
Internal Flow ◽  
Oil And Gas Industry ◽  
Labyrinth Seal ◽  
Rolling Motion ◽  
Turbo Expander ◽  
Liquid Natural Gas

With the development of offshore oil and gas industry, LNG turbo expanders are widely used in Floating Liquid Natural Gas equipment (FLNG) for natural gas transportation. The performance characteristic of the turbo expander is significant affected by the rolling motion caused by the ocean conditions. As an important part of expander, the labyrinth seal is directly related to the safety of the expander, so it is necessary to study the performance characteristic of labyrinth seal under rolling motion. In this paper, CFD is used to simulate the internal flow field of labyrinth seals under different rolling periods and sloshing amplitudes conditions. The distribution of the pressure drop is obtained, and the influence of rolling motion on different labyrinth seal radial clearances and cavity depths are discussed. The results indicate that variation periods of the pressure drop are consistent with the rolling periods, and the larger the rolling amplitude is, the larger pressure drop fluctuation can be observed. Additionally, the fluctuation characteristic is significantly affected by gap widths and cavity depths.

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