scholarly journals Laboratory Physical Experiments on the Saltwater Upconing and Recovery of Island Freshwater Lenses: Case Study of a Coral Island, China

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1137
Author(s):  
Yuxi Li ◽  
Longcang Shu ◽  
Li Zhen ◽  
Hu Li ◽  
Ran Wang ◽  
...  
Keyword(s):  
Critical Value ◽  
Upward Trend ◽  
Freshwater Lens ◽  
Physical Experiments ◽  
Large Gradient ◽  
Single Well ◽  
Development And Utilization ◽  
Coral Island ◽  
Freshwater Lenses

The research of saltwater upconing is crucial for the development and utilization of island freshwater resources. In this paper, a laboratory physical experiment device was developed, and the saltwater upconing and recovery of island freshwater lenses were investigated using rainfall simulations and single-well and multi-well pumping tests with various pumping intensities. The results of the experiment revealed that: (1) The thickness of the freshwater lens increased continuously and linearly during the early stages of rainfall. As the rainfall continued, the upward trend slowed and eventually leveled off. (2) Under the same pumping duration, when the pumping intensity was less than the critical pumping intensity, the increasing height rate of the saltwater upconing increased linearly at a small gradient, and when the pumping intensity was greater than the critical value, the rising height rate of the saltwater upconing increased linearly at a large gradient. (3) Under the same pumping intensity conditions, the pumping duration of the multi-well was longer than that of the single-well pumping, and the pumping volume of the multi-well was also greater than that of the single-well pumping. The experiment results can provide support for the development and utilization of island freshwater lens.

scholarly journals Impact of Island Urbanization on Freshwater Lenses: A Case Study on a Small Coral Island

Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3272
Author(s):  
Zihan Ling ◽  
Longcang Shu ◽  
Ying Sun ◽  
Ran Wang ◽  
Yuxi Li
Keyword(s):  
Stable State ◽  
Visual Modflow ◽  
Freshwater Resources ◽  
Freshwater Lens ◽  
Rational Development ◽  
Coral Island ◽  
Formation And Evolution ◽  
Set Up ◽  
Freshwater Lenses

Freshwater resources on small coral islands mainly exist in the form of freshwater lenses. The freshwater lens is highly vulnerable to salinization due to natural recharge variations and urbanization construction. However, it is unclear how a freshwater lens evolves under the influence of urbanization construction and which factors control its evolution. Based on the hydrogeological data of a small coral island in China, a corresponding 3D numerical model was established by the Visual MODFLOW software to investigate the formation and evolution of freshwater lenses under natural conditions. Thereby, the island reclamation scenario and impermeable surface scenario were set up and the changes in morphology and volume of the freshwater lens were analyzed. The results show the following: (1) After island reclamation and island building, the freshwater lens would reach a stable state after 25 years and the freshwater lens would also appear in the newly added part of the island with a thickness of 9.5 m, while the volume of the total freshwater lens would increase to 1.22 times that of the original island. (2) When the impermeable surface is built at different positions of the island, the reduction in the volume of the freshwater lens, in the order from large to small, is Scenario B (northeast side), Scenario A (southwest side) and Scenario C (central); with the increase in the impermeable surface area, the volume of the freshwater lens would gradually decrease and the volume of the freshwater lens would decrease by more than 50% with the impermeable surface exceeding 30% of the island area. The study has important implications for the conservation and rational development of subsurface freshwater resources on islands.

scholarly journals How Do Trade-Offs and Synergies between Ecosystem Services Change in the Long Period? The Case Study of Uxin, Inner Mongolia, China

2019 ◽  
Vol 11 (21) ◽  
pp. 6041 ◽  
Author(s):  
Zhang ◽  
Li ◽  
Buyantuev ◽  
Bao ◽  
Zhang
Keyword(s):  
Ecosystem Services ◽  
Inner Mongolia ◽  
Stepwise Regression ◽  
Driving Forces ◽  
Extended Period ◽  
Trade Offs ◽  
Development And Utilization ◽  
Long Term Trends

Ecosystem services management should often expect to deal with non-linearities due to trade-offs and synergies between ecosystem services (ES). Therefore, it is important to analyze long-term trends in ES development and utilization to understand their responses to climate change and intensification of human activities. In this paper, the region of Uxin in Inner Mongolia, China, was chosen as a case study area to describe the spatial distribution and trends of 5 ES indicators. Changes in relationships between ES and driving forces of dynamics of ES relationships were analyzed for the period 1979–2016 using a stepwise regression. We found that: the magnitude and directions in ES relationships changed during this extended period; those changes are influenced by climate factors, land use change, technological progress, and population growth.

Improving Operational Efficiency Using Automated Time Analysis for Multi-Well Pad Fracturing

2021 ◽  
Author(s):  
Fahd Siddiqui ◽  
Mohammadreza Kamyab ◽  
Michael Lowder
Keyword(s):  
Real Time ◽  
Operational Efficiency ◽  
Permian Basin ◽  
Potential Cost ◽  
Time Period ◽  
Cloud Server ◽  
The Us ◽  
Single Well ◽  
Complete Automation

Abstract The economic success of unconventional reservoirs relies on driving down completion costs. Manually measuring the operational efficiency for a multi-well pad can be error-prone and time-prohibitive. Complete automation of this analysis can provide an effortless real-time insight to completion engineers. This study presents a real-time method for measuring the time spent on each completion activity, thereby enabling the identification and potential cost reduction avenues. Two data acquisition boxes are utilized at the completion site to transmit both the fracturing and wireline data in real-time to a cloud server. A data processing algorithm is described to determine the start and end of these two operations for each stage of every well on the pad. The described method then determines other activity intervals (fracturing swap-over, wireline swap-over, and waiting on offset wells) based on the relationship between the fracturing and wireline segments of all the wells. The processed data results can be viewed in real-time on mobile or computers connected to the cloud. Viewing the full operational time log in real-time helps engineers analyze the whole operation and determine key performance indicators (KPIs) such as the number of fractured stages per day, pumping percentage, average fracture, and wireline swap-over durations for a given time period. In addition, the performance of the day and night crews can be evaluated. By plotting a comparison of KPIs for wireline and fracturing times, trends can be readily identified for improving operational efficiency. Practices from best-performing stages can be adopted to reduce non-pumping times. This helps operators save time and money to optimize for more efficient operations. As the number of wells increases, the complexity of manual generation of time-log increases. The presented method can handle multi-well fracturing and wireline operations without such difficulty and in real-time. A case study is also presented, where an operator in the US Permian basin used this method in real-time to view and optimize zipper operations. Analysis indicated that the time spent on the swap over activities could be reduced. This operator set a realistic goal of reducing 10 minutes per swap-over interval. Within one pad, the goal was reached utilizing this method, resulting in reducing 15 hours from the total pad time. The presented method provides an automated overview of fracturing operations. Based on the analysis, timely decisions can be made to reduce operational costs. Moreover, because this method is automated, it is not limited to single well operations but can handle multi-well pad completion designs that are commonplace in unconventionals.

scholarly journals MODEL PENGEMBANGAN DAN PEMANFAATAN WAKAF TUNAI UNTUK PENDIDIKAN TINGGI (STUDI KASUS WAKAF AMERTA AIRLANGGA)

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Muhamad Syadid ◽  
Muhammad Arfan Muammar
Keyword(s):  
Higher Education ◽  
The Other ◽  
Economic Conditions ◽  
Educational Institutions ◽  
Tertiary Level ◽  
Models Of Development ◽  
Qualitative Descriptive ◽  
Key Words Development ◽  
Development And Utilization

ABSTRACTThe The increasingly difficult economic conditions require educational institutions at the tertiary level to develop a model for collecting funds from the community, one of which is through cash waqf. Airlangga University already has a model of developing and utilizing campus-based cash waqf. So with this waqf solution the community can be helped especially by students to continue their education. From here the authors are encouraged to conduct research on "Models of Development and Utilization of Cash Waqf for Higher Education (Case Study of Waqf Amerta Airlangga.".With the formulation of the problem: first, How to use cash waqf for higher education in Amerta Airlangga Waqf. Second, how to model the development of cash waqf in Amerta Airlangga. The method of this study used qualitative-descriptive because the data was qualitative, the data was not quantitative which used statistic. Practically, the data collection used three methods, they were: interview, observation, and documentation.Based on the results of research in Waqf Amerta Airlangga, it is known that the Community donated funds to the Waqf Amerta Airlangga through PUSPAS which is divided into two types, namely non-endowment social donations and endowment donations. Then some of the non-waqf funds were directly put into social donation accounts which could be directly utilized for the Airlangga University PUSPAS program, by 85%. While the other 15% is for the operations of PUSPAS Airlangga University. The Waqf Fund through the Amerta Endowments program will be managed separately for the fund as an investment in a number of portfolios. Key Words : Development and Utilization Model, Cash Waqf, Higher Education

scholarly journals Risk analysis of production process for food SMEs using FMEA method: a case study

2021 ◽  
Vol 331 ◽  
pp. 02010
Author(s):  
Prima Fithri ◽  
Muhammad Rafi ◽  
Pawenary ◽  
A. S. Prabuwono
Keyword(s):  
Human Resources ◽  
Production Process ◽  
Critical Value ◽  
Risk Priority Number ◽  
Effect Analysis ◽  
Increase Productivity ◽  
Fmea Method ◽  
Bread Production ◽  
A Company

The increasing development of the industry makes every industry have to compete with other competitors to gain an edge. The advantages of competition are influenced by several factors, one of which is good human resource management. Where if a company has good human resources, it will increase profits indirectly and can increase productivity. This research discusses case studies about the potential dangers of IKM Heppy Bakery’s potential dangers that can harm workers in bread production. The method used is Failure Mode And Effect Analysis (FMEA). Later, the data will be filled and given a rating distinguished into three parts: severity, occurrence, and detection. The data were obtained through questionnaires given to 3 workers at IKM Heppy Bakery and filled in rating values based on the provisions that have been given to the questionnaire. This Value helps determine the Risk Priority Number (RPN) obtained from multiplication between severity, occurrence, and detection. After processing the RPN multiplication data, the highest RPN value was obtained by 193 with the danger factor of the operator overheating and dehydrating due to high temperatures. Furthermore, the calculation of critical Value was obtained by 109. Based on the critical Value obtained seven hazard factors above the critical value, these seven hazard factors need to be improved so that workers do not avoid accidents when conducting the production process.

Numerical Simulation of Upconing and Freshwater Lens Breakage in a Coral Island

2009 ◽  
pp. 154-159
Author(s):  
Congzhi Zhou ◽  
Qin Yang ◽  
Zhengdong Fang ◽  
Hengguo Liang ◽  
Hao Wang
Keyword(s):  
Numerical Simulation ◽  
Freshwater Lens ◽  
Coral Island

scholarly journals A Sustainable Metropolis: Perspectives of Population, Productivity and Parity

2018 ◽  
Vol 10 (11) ◽  
pp. 4264 ◽  
Author(s):  
Youngho Chang ◽  
Zheng Fang ◽  
Shigeyuki Hamori ◽  
Dawn Chow
Keyword(s):  
Sustainable Development ◽  
Three Dimensions ◽  
Government Budget ◽  
Upward Trend ◽  
Natural Systems ◽  
Sustainability Index ◽  
Integrated Studies ◽  
The Government ◽  
Patterns And Processes

Research on countries’ sustainable development has called for more complete assessments of sustainability. Indeed, integrated studies coupling human and natural systems reveal new and complex patterns and processes not evident when studied in isolation. In line with the need to construct an index that takes into account a more holistic notion of sustainability, this study investigates the overall sustainable development of a metropolis through three dimensions, population, productivity and parity, and takes Singapore as a case study. We incorporate these three dimensions in our construction of a total sustainability index. We find that the population dimension has remained relatively unchanged, while the productivity dimension has gradually moved towards sustainability. The parity dimension has moved towards sustainability before 2002, but it shows ups and downs until 2012 when an upward trend toward sustainability appeared again. Results from this study imply that the government should pay attention to controlling the size of the population of temporary residents, and increasing the government budget for the environment.

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