scholarly journals Mechanisms underlying increased nest predation in natural gas fields: a test of the mesopredator release hypothesis

Ecosphere ◽  
2019 ◽  
Vol 10 (5) ◽  
Author(s):  
Lindsey E. Sanders ◽  
Anna D. Chalfoun
2019 ◽  
Vol 12 (4) ◽  
pp. 141-155 ◽  
Author(s):  
Ahmed Mahdi

This article examines the claim that Israel’s natural gas exports from its Mediterranean gas fields will give geopolitical leverage to Tel Aviv over the importing countries. Using the geoeconomic tradition of Klaus Knorr and others who wrote about applying leverage using economic resources to gain geopolitical advantage, it is argued that certain criteria have to be satisfied for economic influence attempts, and that Israel’s gas exports do not satisfy these criteria. They include the importer’s supply vulnerability, the supplier’s demand vulnerability, and the salience of energy as an issue between both countries. Israeli gas exports to Egypt are used as a case study.


Methane ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 24-37
Author(s):  
Muhammad Alfiza Farhan ◽  
Yuichi Sugai ◽  
Nuhindro Priagung Widodo ◽  
Syafrizal Syafrizal

The leakage of methane from the subsurface on the coalfield or natural gas field invariably becomes an important issue nowadays. In notable addition, materials such as activated carbon, zeolites, and Porapak have been successfully identified as adsorbents. Those adsorbents could adsorb methane at atmospheric pressure and room temperature. Therefore, in this scholarly study, a new method using adsorbents to detect points of methane leakage that can cover a wide-scale area was developed. In the beginning, the most capable adsorbent should be determined by quantifying adsorbed methane amount. Furthermore, checking the possibility of adsorption in the column diffusion and desorption method of adsorbents is equally necessary. The most capable adsorbent was activated carbon (AC), which can adsorb 1.187 × 10−3 mg-CH4/g-AC. Hereinafter, activated carbon successfully can adsorb methane through column diffusion, which simulates the situation of on-site measurement. The specific amount of adsorbed methane when the initial concentrations of CH4 in a bag were 200 ppm, 100 ppm, and 50 ppm was found to be 0.818 × 10−3 mg-CH4/g-AC, 0.397 × 10−3 mg-CH4/g-AC, 0.161 × 10−3 mg-CH4/g-AC, respectively. Desorption of activated carbon analysis shows that methane concentration increases during an hour in the temperature bath under 80 °C. In conclusion, soil methane leakage points can be detected using activated carbon by identifying the observed methane concentration increase.


Author(s):  
Vitaliy Makarov ◽  
◽  
Mykola Kaplin ◽  

The subject of the research is the directions of development of the gas industry of Ukraine. The purpose of the study is to develop a mathematical model for calculating the program of development of the country's gas industry to solve the problem of choosing options for commissioning of new natural gas fields and intensification of existing fields. The methods of system analysis, linear programming, comparative analysis and expert evaluations are used in the work. A model for calculating a program for the development of the gas industry is proposed to solve the problem of choosing options for commissioning new natural gas fields and intensifying existing fields. The model is based on representing development options with achievable volumes of annual production increase in integer linear programming problems. New and operating natural gas fields can be presented in the model with statistical information on their distribution by reserves and depths with the corresponding development costs, as well as the dependences of the predicted annual production volume on the measures taken and technologies to improve the efficiency of gas extraction. Model calculations provide a two-stage method for determining the options for the development of the industry. At the first stage, a variety of options are optimized according to the criterion of unit costs per 1,000 m3 of gas produced during the entire program period. The second stage ensures the optimal distribution of the selected options between the periods of the program using the criterion of the production volume and with the limited costs of the previous period for the preparation, prospecting and exploration of deposits. The results of calculating feasible options for the development of the gas production industry based on statistical information on volume, mining and geological and cost indicators of the development of resources and natural gas reserves are presented. The calculations investigated the options for the uniform distribution of investment, as well as their growth from the first stage to the next. For both cases, the priority is set for the selection of fields with large reserves at the same depths. Such a procedure for putting fields into operation is expedient, both from the point of view of the criterion for the optimal functioning of the industry over a long period of time – the unit costs of production, and on the basis of considerations of achieving the highest volumes of extraction in the shortest possible time. In the case of small capital investments in the development of the industry, the model selects small-volume reserves of deposits according to the structure of Ukrainian reserves.


2019 ◽  
Vol 46 (3) ◽  
pp. 463-470 ◽  
Author(s):  
Jian LI ◽  
Zhongxi HAN ◽  
Qituan YAN ◽  
Shuying WANG ◽  
Shouguo GE
Keyword(s):  

2019 ◽  
Vol 59 (2) ◽  
pp. 803
Author(s):  
Abdul Qader ◽  
Jai Kant Pandit

CO2CRC, in collaboration with the University of Melbourne and the University of New South Wales, is testing two novel CO2 capture technologies designed for both on-shore and off-shore natural gas applications in a state-of-the-art experimental capture rig at CO2CRC’s Otway National Research Facility. The goal is to develop robust and compact technology for high pressure natural gas separation over a range of adjusted high CO2 concentrations mimicking various gas field conditions. These technologies would facilitate developing new gas fields to recover methane in a cost-effective manner which is currently uneconomical with conventional technologies. In the first stage of testing, commercially available materials (adsorbents and membranes) were used for benchmarking. Results from both adsorbent and membrane technologies are encouraging with respect to recovery and purity of CO2 and methane with the prospect of commercial application.


2015 ◽  
Vol 64 ◽  
pp. 111-119 ◽  
Author(s):  
Kjetil Trovik Midthun ◽  
Marte Fodstad ◽  
Lars Hellemo

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