Response of Carbon Sink Dynamic Behaviors to River Flood in Karst Area – A Case Study in the Li River of Guilin

2013 ◽  
Vol 830 ◽  
pp. 353-362
Author(s):  
Wen Yue Du ◽  
Qi Liu ◽  
Yan Jiang ◽  
You Ling Li
Keyword(s):  
Water Temperature ◽  
Flow Rate ◽  
Ph Value ◽  
Carbon Sink ◽  
Karst Area ◽  
Carbon Dioxide Partial Pressure ◽  
Carbon Sinks ◽  
Frequency Monitoring ◽  
Flood Flow

Li River appeared successively three times floods during May 8-17, 2012. We were high-frequency monitoring during the flood once every hour, real time monitoring the pH value, water temperature, EC(electrical conductivity), pCO2(carbon dioxide partial pressure), HCO3- and flow rate, analyzing karst carbon sinks dynamic changes during the flood. It was found that river hydrochemistry and karst carbon sinks in different stages with different variations in Li River. These floods were divided into 5 stages to discuss, researches have shown: AtIand Vstage the river hydrochemistry is not subjected to flooding, pCO2 and pH value, water temperature has distinct characteristics of diurnal variation. EC, flow rate and HCO3- is relatively stable; II, III and IV stage appear different changes characteristics are due to effects of flood, flow rate and HCO3- have a positive correlation at IV stage, with opposite of stage II and III stage. We use water chemistry-runoff method to calculate the amount of carbon sinks in the flood, found in the flood related coefficients between carbon sink and HCO3-, flow rate respectively 0.87 and 0.33. The carbon sink is 3491.06 t C during the flood monitoring, in which carbon sink at IVstage in flood are 4.52 times prior to the flood, which account for that carbon sink in the flood is much larger than the front of flood.

The Dynamic Response of Carbon Sink to Rainfall in Karst Area - A Case Study from Maocun Karst Ecosystem

2013 ◽  
Vol 671-674 ◽  
pp. 2697-2703
Author(s):  
Wei Tang ◽  
Jian Hua Cao
Keyword(s):  
Rainfall Intensity ◽  
Carbon Sink ◽  
Saturation Index ◽  
Karst Area ◽  
Carbon Dioxide Partial Pressure ◽  
High Resolution Data ◽  
Highly Sensitive ◽  
International Attention ◽  
Different Seasons

Because of global warming, research on carbon sink is increasingly gaining international attention, there are 1.3 GtC/year unknown sink in the continental biosphere. In this study, we will present the high-resolution data of the DIC(DIC=H2CO3+HCO3−+CO32−), pH, and Pco2(carbon dioxide partial pressure) measured during the storm scale of Maocun subterranean river in Guilin on June 13-17,2010, which shows a high response to the rainfall. Though monitoring the rainfall, water level, water temperature, PH, Ec(electrical conductivity) and calculating of SIc (saturation index) and Pco2, to analyze the dynamic behaviors of DIC and discharge in storm scale. Studies suggest that DIC, pH, SIc and PCO2 are highly sensitive to rainfall, Discharge obviously increases after precipitation and changes with the rainfall intensity. According to the comparision of carbon sink between March 7, 2010 and June 13, 2010 of Maocun subterranean river, the data presents that carbon sink is obviously increased. Furthermore, carbon sink changes with different seasons, the result shows that rainy season 's carbon sink is larger than dry season, the research presents that pecipitation is an important factor in influencing the karst carbon sink potential.

scholarly journals Prediction of Life Cycle Carbon Emissions of Sponge City Projects: A Case Study in Shanghai, China

2018 ◽  
Vol 10 (11) ◽  
pp. 3978 ◽  
Author(s):  
Xiaohu Lin ◽  
Jie Ren ◽  
Jingcheng Xu ◽  
Tao Zheng ◽  
Wei Cheng ◽  
...  
Keyword(s):  
Life Cycle ◽  
Carbon Emissions ◽  
Carbon Emission ◽  
Carbon Sink ◽  
Carbon Sinks ◽  
Sponge City ◽  
Study Results ◽  
Accounting Model ◽  
Whole Life Cycle

In recent years, China has been vigorously carrying out the planning and implementation of Sponge City. Since the implementation of Sponge City projects involves substantial materials and energy consumption, it is significant to account corresponding carbon emissions and sinks. The existed studies about carbon emission of stormwater management measures, however, are not able to take the whole life cycle and different facilities into consideration. Therefore, this study develops a comprehensive accounting model based on Intergovernmental Panel on Climate Change (IPCC) guidelines and life cycle assessment (LCA) method to predict carbon emissions and carbon sinks of Sponge City projects more comprehensively and accurately. The model is applied to an actual residential community in Shanghai as a case study. Results show that the total indirect carbon emission is estimated to be 774,277 kg CO2 eq during a 30-year lifespan, among which carbon emissions from operation and maintenance phases are 2570 kg CO2 eq/year and 7309 kg CO2 eq/year, respectively, both directly proportional to the service life of the facilities. Three kinds of achievable carbon sinks are carbon sequestration in green space (5450 kg CO2 eq/year), carbon sink from rainwater utilization (15,379 kg CO2 eq/year) and carbon sink from runoff pollutant removal (19,552 kg CO2 eq/year). Carbon neutrality is expected to be reached after approximately 19 years. The established carbon emission accounting model can contribute to better planning and construction of Sponge City in China and enhance further energy conservation and carbon emission reduction.

Pyrolysis of brown algae (Bifurcaria Bifurcata) in a stainless steel tubular reactor: From a review to a case study

2018 ◽  
Vol 14 (1) ◽  
pp. 31-60 ◽  
Author(s):  
M. Y. Guida ◽  
F. E. Laghchioua ◽  
A. Hannioui
Keyword(s):  
Particle Size ◽  
Stainless Steel ◽  
Flow Rate ◽  
Brown Algae ◽  
Tubular Reactor ◽  
Nitrogen Flow ◽  
Nitrogen Flow Rate ◽  
Bifurcaria Bifurcata ◽  
Bio Oil

This article deals with fast pyrolysis of brown algae, such as Bifurcaria Bifurcata at the range of temperature 300–800 °C in a stainless steel tubular reactor. After a literature review on algae and its importance in renewable sector, a case study was done on pyrolysis of brown algae especially, Bifurcaria Bifurcata. The aim was to experimentally investigate how the temperature, the particle size, the nitrogen flow rate (N2) and the heating rate affect bio-oil, bio-char and gaseous products. These parameters were varied in the ranges of 5–50 °C/min, below 0.2–1 mm and 20–200 mL. min–1, respectively. The maximum bio-oil yield of 41.3wt% was obtained at a pyrolysis temperature of 600 °C, particle size between 0.2–0.5 mm, nitrogen flow rate (N2) of 100 mL. min–1 and heating rate of 5 °C/min. Liquid product obtained under the most suitable and optimal condition was characterized by elemental analysis, 1H-NMR, FT-IR and GC-MS. The analysis of bio-oil showed that bio-oil from Bifurcaria Bifurcata could be a potential source of renewable fuel production and value added chemicals.

scholarly journals Thermal Efficiency and Economics of a Boil-Off Hydrogen Re-Liquefaction System Considering the Energy Efficiency Design Index for Liquid Hydrogen Carriers

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4566
Author(s):  
Minsoo Choi ◽  
Wongwan Jung ◽  
Sanghyuk Lee ◽  
Taehwan Joung ◽  
Daejun Chang
Keyword(s):  
Flow Rate ◽  
Life Cycle Cost ◽  
Specific Energy Consumption ◽  
Liquid Hydrogen ◽  
Efficient Design ◽  
Fuel Cell Stack ◽  
Energy Efficiency Design Index ◽  
The Cost ◽  
Large Flow

This study analyzes the thermodynamic, economic, and regulatory aspects of boil-off hydrogen (BOH) in liquid hydrogen (LH2) carriers that can be re-liquefied using a proposed re-liquefaction system or used as fuel in a fuel cell stack. Five LH2 carriers sailing between two designated ports are considered in a case study. The specific energy consumption of the proposed re-liquefaction system varies from 8.22 to 10.80 kWh/kg as the re-liquefaction-to-generation fraction (R/G fraction) is varied. The economic evaluation results show that the cost of re-liquefaction decreases as the re-liquefied flow rate increases and converges to 1.5 $/kg at an adequately large flow rate. Three energy efficient design index (EEDI) candidates are proposed to determine feasible R/G fractions: an EEDI equivalent to that of LNG carriers, an EEDI that considers the energy density of LH2, and no EEDI restrictions. The first EEDI candidate is so strict that the majority of the BOH should be used as fuel. In the case of the second EEDI candidate, the permittable R/G fraction is between 25% and 33%. If the EEDI is not applied for LH2 carriers, as in the third candidate, the specific life-cycle cost decreases to 67% compared with the first EEDI regulation.

Effect of Water Temperature, pH Value, and Film Thickness on the Wettability Behaviour of Copper Surfaces Coated with Copper Using EB-PVD Technique

2019 ◽  
Vol 60 ◽  
pp. 124-141 ◽  
Author(s):  
Naser Ali ◽  
Joao Amaral Teixeira ◽  
Abdulmajid Addali
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Film Thickness ◽  
Water Temperature ◽  
Ph Value ◽  
Surface Wettability ◽  
Copper Surfaces ◽  
Force Microscopy ◽  
Atomic Force ◽  
Static Contact

This research investigates the effect of surface roughness, water temperature, and pH value on the wettability behaviour of copper surfaces. An electron beam physical vapour deposition technique was used to fabricate 25, 50, and 75 nm thin films of copper on the surface of copper substrates. Surface topographical analysis, of the uncoated and coated samples, was performed using an atomic force microscopy device to observe the changes in surface microstructure. A goniometer device was then employed to examine the surface wettability of the samples by obtaining the static contact angle between the liquid and the attached surface using the sessile drops technique. Waters of pH 4, 7, and 9 were employed as the contact angle testing fluids at a set of fixed temperatures that ranged from 20°C to 60°C. It was found that increasing the deposited film thickness reduces the surface roughness of the as-prepared copper surfaces and thus causing the surface wettability to diverge from its initial hydrophobic nature towards the hydrophilic behaviour region. A similar divergence behaviour was seen with the rise in temperature of water of pH 4, and 9. In contrast, the water of pH 7, when tested on the uncoated surface, ceased to reach a contact angle below 90o. It is believed that the observed changes in surface wettability behaviour is directly linked to the liquid temperature, pH value, surface roughness, along with the Hofmeister effect between the water and the surface in contact.

scholarly journals Experimental Investigation on Improvement of Wet Cooling Tower Efficiency with Diverse Packing Compaction Using ANN-PSO Algorithm

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 167
Author(s):  
Hasan Alimoradi ◽  
Madjid Soltani ◽  
Pooriya Shahali ◽  
Farshad Moradi Kashkooli ◽  
Razieh Larizadeh ◽  
...  
Keyword(s):  
Neural Network ◽  
Water Temperature ◽  
Water Flow ◽  
Flow Rate ◽  
Cooling Tower ◽  
Air Flow ◽  
Water Flow Rate ◽  
Pso Algorithm ◽  
Outlet Temperature ◽  
Air Flow Rate

In this study, a numerical and empirical scheme for increasing cooling tower performance is developed by combining the particle swarm optimization (PSO) algorithm with a neural network and considering the packing’s compaction as an effective factor for higher accuracies. An experimental setup is used to analyze the effects of packing compaction on the performance. The neural network is optimized by the PSO algorithm in order to predict the precise temperature difference, efficiency, and outlet temperature, which are functions of air flow rate, water flow rate, inlet water temperature, inlet air temperature, inlet air relative humidity, and packing compaction. The effects of water flow rate, air flow rate, inlet water temperature, and packing compaction on the performance are examined. A new empirical model for the cooling tower performance and efficiency is also developed. Finally, the optimized performance conditions of the cooling tower are obtained by the presented correlations. The results reveal that cooling tower efficiency is increased by increasing the air flow rate, water flow rate, and packing compaction.

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