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A comprehensive review of greenhouse shapes and its applications

Ravinder Kumar SAHDEV,Ashwani Kumar DHINGRA,Mahesh KUMAR

《能源前沿(英文)》 2019年 第13卷 第3期   页码 427-438 doi: 10.1007/s11708-017-0464-8

摘要: Greenhouse technology is a practical option for the production and drying of agricultural products in controlled environment. For the successful design of a greenhouse, the selection of a suitable shape and orientation is of great importance. Of various shapes of greenhouses, the even-span roof and the Quonset shape greenhouses are the most commonly used for crop cultivation and drying. The orientation of greenhouses is kept east–west for maximum utilization of solar radiations. Hybrid and modified greenhouse dryers have been proposed for drying of products. The agricultural products dried in greenhouses are found to be better in quality as compared to open sun drying because they are protected from dust, rain, insects, birds and animals. Moreover, various greenhouses shapes along with their applications have been reviewed.

关键词: greenhouse shapes     drying     solar energy     agriculture products     orientation    

A new meshless approach for bending analysis of thin plates with arbitrary shapes and boundary conditions

《结构与土木工程前沿(英文)》 2022年 第16卷 第1期   页码 75-85 doi: 10.1007/s11709-021-0798-5

摘要: An efficient and meshfree approach is proposed for the bending analysis of thin plates. The approach is based on the choice of a set of interior points, for each of which a basis function can be defined. Plate deflection is then approximated as the linear combination of those basis functions. Unlike traditional meshless methods, present basis functions are defined in the whole domain and satisfy the governing differential equation for plate. Therefore, no domain integration is needed, while the unknown coefficients of deflection expression could be determined through boundary conditions by using a collocation point method. Both efficiency and accuracy of the approach are shown through numerical results of plates with arbitrary shapes and boundary conditions under various loads.

关键词: plate     bending     meshless method     collocation    

Probabilistic stability of uncertain composite plates and stochastic irregularity in their buckling mode shapes

《结构与土木工程前沿(英文)》   页码 179-190 doi: 10.1007/s11709-022-0888-z

摘要: In this study, the mechanical properties of the composite plate were considered Gaussian random fields and their effects on the buckling load and corresponding mode shapes were studied by developing a semi-analytical non-intrusive approach. The random fields were decomposed by the Karhunen−Loève method. The strains were defined based on the assumptions of the first-order and higher-order shear-deformation theories. Stochastic equations of motion were extracted using Euler–Lagrange equations. The probabilistic response space was obtained by employing the non-intrusive polynomial chaos method. Finally, the effect of spatially varying stochastic properties on the critical load of the plate and the irregularity of buckling mode shapes and their sequences were studied for the first time. Our findings showed that different shear deformation plate theories could significantly influence the reliability of thicker plates under compressive loading. It is suggested that a linear relationship exists between the mechanical properties’ variation coefficient and critical loads’ variation coefficient. Also, in modeling the plate properties as random fields, a significant stochastic irregularity is obtained in buckling mode shapes, which is crucial in practical applications.

关键词: uncertain composite plate     stochastic assume mode method     Karhunen−Loève theorem     polynomial chaos approach     plate buckling     irregularity in buckling mode shapes    

Catalyst particle shapes and pore structure engineering for hydrodesulfurization and hydrodenitrogenation

《化学科学与工程前沿(英文)》 2022年 第16卷 第6期   页码 897-908 doi: 10.1007/s11705-021-2127-x

摘要: Catalyst particle shapes and pore structure engineering are crucial for alleviating internal diffusion limitations in the hydrodesulfurization (HDS)/hydrodenitrogenation (HDN) of gas oil. The effects of catalyst particle shapes (sphere, cylinder, trilobe, and tetralobe) and pore structures (pore diameter and porosity) on HDS/HDN performance at the particle scale are investigated via mathematical modeling. The relationship between particle shape and effectiveness factor is first established, and the specific surface areas of different catalyst particles show a positive correlation with the average HDS/HDN reaction rates. The catalyst particle shapes primarily alter the average HDS/HDN reaction rate to adjust the HDS/HDN effectiveness factor. An optimal average HDS/HDN reaction rate exists as the catalyst pore diameter and porosity increase, and this optimum value indicates a tradeoff between diffusion and reaction. In contrast to catalyst particle shapes, the catalyst pore diameter and the porosity of catalyst particles primarily alter the surface HDS/HDN reaction rate to adjust the HDS/HDN effectiveness factor. This study provides insights into the engineering of catalyst particle shapes and pore structures for improving HDS/HDN catalyst particle efficiency.

关键词: hydrodesulfurization     hydrodenitrogenation     particle shape     pore structure    

An ANN-exhaustive-listing method for optimization of multiple building shapes and envelope properties

Yaolin LIN, Wei YANG

《能源前沿(英文)》 2021年 第15卷 第2期   页码 550-563 doi: 10.1007/s11708-019-0607-1

摘要: With increasing awareness of sustainability, demands on optimized design of building shapes with a view to maximize its thermal performance have become stronger. Current research focuses more on building envelopes than shapes, and thermal comfort of building occupants has not been considered in maximizing thermal performance in building shape optimization. This paper attempts to develop an innovative ANN (artificial neural network)-exhaustive-listing method to optimize the building shapes and envelope physical properties in achieving maximum thermal performance as measured by both thermal load and comfort hour. After verified, the developed method is applied to four different building shapes in five different climate zones in China. It is found that the building shape needs to be treated separately to achieve sufficient accuracy of prediction of thermal performance and that the ANN is an accurate technique to develop models of discomfort hour with errors of less than 1.5%. It is also found that the optimal solutions favor the smallest window-to-external surface area with triple-layer low-E windows and insulation thickness of greater than 90 mm. The merit of the developed method is that it can rapidly reach the optimal solutions for most types of building shapes with more than two objective functions and large number of design variables.

关键词: ANN (artificial neural network)     exhaustive-listing     building shape     optimization     thermal load     thermal comfort    

A novel structural modification to eliminate the early coupling between bending and torsional mode shapes

Nazim Abdul NARIMAN

《结构与土木工程前沿(英文)》 2017年 第11卷 第2期   页码 131-142 doi: 10.1007/s11709-016-0376-4

摘要: In this paper, a novel structural modification approach has been adopted to eliminate the early coupling between the bending and torsional mode shapes of vibrations for a cable stayed bridge model generated using ABAQUS software. Two lateral steel beams are added to the middle span of the structure. Frequency analysis is dedicated to obtain the natural frequencies of the first eight mode shapes of vibrations before and after the structural modification approach. Numerical simulations of wind excitations are conducted for the 3D model of the cable stayed bridge with duration of 30 s supporting on real data of a strong wind from the literature. Both vertical and torsional displacements are calculated at the mid span of the deck to analyze both the bending and the torsional stiffness of the system before and after the structural modification. The results of the frequency analysis after applying lateral steel beams declared a safer structure against vertical and torsional vibrations and rarely expected flutter wind speed. Furthermore, the coupling between the vertical and torsional mode shapes has been removed to larger natural frequencies magnitudes with a high factor of safety. The novel structural approach manifested great efficiency in increasing vertical and torsional stiffness of the structure.

关键词: aeroelastic instability     structural damping     flutter wind speed     bending stiffness     torsional stiffness    

Analyzing the energy intensity and greenhouse gas emission of Canadian oil sands crude upgrading through

Anton ALVAREZ-MAJMUTOV,Jinwen CHEN

《化学科学与工程前沿(英文)》 2014年 第8卷 第2期   页码 212-218 doi: 10.1007/s11705-014-1424-z

摘要: This paper presents an evaluation of the energy intensity and related greenhouse gas/CO emissions of integrated oil sands crude upgrading processes. Two major oil sands crude upgrading schemes currently used in Canadian oil sands operations were investigated: coking-based and hydroconversion-based. The analysis, which was based on a robust process model of the entire process, was constructed in Aspen HYSYS and calibrated with representative data. Simulations were conducted for the two upgrading schemes in order to generate a detailed inventory of the required energy and utility inputs: process fuel, steam, hydrogen and power. It was concluded that while hydroconversion-based scheme yields considerably higher amount of synthetic crude oil (SCO) than the coker-based scheme (94 wt-% vs. 76 wt-%), it consumes more energy and is therefore more CO -intensive (413.2 kg CO /m vs. 216.4 kg CO /m ). This substantial difference results from the large amount of hydrogen consumed in the ebullated-bed hydroconverter in the hydroconversion-based scheme, as hydrogen production through conventional methane steam reforming is highly energy-intensive and therefore the major source of CO emission. Further simulations indicated that optimization of hydroconverter operating variables had only a minor effect on the overall CO emission due to the complex trade-off effect between energy inputs.

关键词: Oil sands crude upgrading     hydroconversion     process modeling     greenhouse gas emissions    

Systematical strategies for wastewater treatment and the generated wastes and greenhouse gases in China

Jingbo GUO, Fang MA, Yuanyuan QU, Ang LI, Liang WANG

《环境科学与工程前沿(英文)》 2012年 第6卷 第2期   页码 271-279 doi: 10.1007/s11783-011-0328-0

摘要: China now faces double challenges of water resources shortage and severe water pollution. To resolve Chinese water pollution problems and reduce its impacts on human health, economic growth and social development, the situation of wastewater treatment was investigated. Excess sludge and greenhouse gases (GHGs) emitted during wastewater treatment were also surveyed. It is concluded that Chinese water pollution problems should be systematically resolved with inclusion of wastewater and the solid waste and GHGs generated during wastewater treatment. Strategies proposed for the wastewater treatment in China herein were also adequate for other countries, especially for the developing countries with similar economic conditions to China.

关键词: wastewater treatment     solid waste     greenhouse gases     systematical strategies    

Transportation: meeting the dual challenges of achieving energy security and reducing greenhouse gas

Michael Quanlu WANG, Hong HUO

《能源前沿(英文)》 2009年 第3卷 第2期   页码 212-225 doi: 10.1007/s11708-009-0016-y

摘要: As the population and economy continue to grow globally, demand for energy will continue to grow. The transportation sector relies solely on petroleum for its energy supply. The United States and China are the top two oil-importing countries. A major issue both countries face and are addressing is energy insecurity as a result of the demand for liquid fuels. Improvements in the energy efficiency of vehicles and the substitution of petroleum fuels with alternative fuels can help contain growth in the demand for transportation oil. Although most alternative transportation fuels - when applied to advanced vehicle technologies - can substantially reduce greenhouse emissions, coal-based liquid fuels may increase greenhouse gas emissions by twice as much as gasoline. Such technologies as carbon capture and storage may need to be employed to manage the greenhouse gas emissions of coal-based fuels. At present, there is no ideal transportation fuel option to solve problems related to transportation energy and greenhouse gas emissions. To solve these problems, research and development efforts are needed for a variety of transportation fuel options and advanced vehicle technologies.

关键词: transportation energy     energy security     greenhouse gases     alternative fuels     vehicle technologies    

Accounting greenhouse gas emissions of food consumption between urban and rural residents in China: a

《能源前沿(英文)》 2022年 第16卷 第2期   页码 357-374 doi: 10.1007/s11708-021-0763-y

摘要: Food consumption is necessary for human survival. On a global scale, the greenhouse gas (GHG) emission related to food consumption accounts for 19%–29% of the total GHG emission. China has the largest population in the world, which is experiencing a rapid development. Under the background of urbanization and the adjustment of the diet structure of Chinese residents, it is critical to mitigate the overall GHG emission caused by food consumption. This study aims to employ a single-region input-output (SRIO) model and a multi-regional input-output (MRIO) model to measure GHG emission generated from food consumption in China and compare the contributions of different industrial sectors, uncovering the differences between urban and rural residents and among different provinces (autonomous regions/municipalities), as well as identifying the driving forces of GHG emission from food consumption at a national level. The results indicate that the total GHG emission generated from food consumption in China tripled from 157 Mt CO2e in 2002 to 452 Mt CO2e in 2017. The fastest growing GHG emission is from the consumption of other processed food and meat products. Although GHG emissions from both urban and rural residents increased, the gap between them is increasing. Agriculture, processing and manufacture of food, manufacture of chemical and transportation, storage and post services sectors are key sectors inducing food consumption related GHG emissions. From a regional perspective, the top five emission provinces (autonomous regions/municipalities) include Shandong, Hubei, Guangdong, Zhejiang, and Jiangsu. Based on such results, policy recommendations are proposed to mitigate the overall GHG emission from food consumption.

关键词: greenhouse gas (GHG) emission     food consumption     industry sectors     mitigation measures     urban governance    

PROPOSED INNOVATION REFORM MODEL FOR THE MINERAL NITROGEN FERTILIZER INDUSTRY IN CHINA TO REDUCE GREENHOUSE

《农业科学与工程前沿(英文)》 2023年 第10卷 第2期   页码 234-247 doi: 10.15302/J-FASE-2022468

摘要:

● The carbon footprint of the nitrogen fertilizer chain has decreased significantly over the last decade.

关键词: carbon accounting     life cycle assessment     policy     product structure    

Field scale measurement of greenhouse gas emissions from land applied swine manure

Devin L. Maurer, Jacek A. Koziel, Kelsey Bruning

《环境科学与工程前沿(英文)》 2017年 第11卷 第3期 doi: 10.1007/s11783-017-0915-9

摘要: Greenhouse gas emissions (GHGs) from swine production systems are relatively well researched with the exception of emissions from land application of manure. GHGs inventories are needed for process-based modeling and science-based regulations. Thus, the objective of this observational study was to measure GHG fluxes from land application of swine manure on a typical corn field. Assessment of GHG emissions from deep injected land-applied swine manure, fall and reapplication in the spring, on a typical US Midwestern corn-on-corn farm was completed. Static chambers were used for flux measurement along with gas analysis on a GC-FID-ECD. Measured gas concentrations were used to estimate GHGs flux using four different models: linear regression, nonlinear regression, first order linear regression and the revised Hutchinson and Mosier (HMR) model, respectively for comparisons. Cumulative flux estimates after manure application of 5.85 × 10 g·ha (1 ha= 0.01 km ) of CO , 6.60 × 10 g·ha of CH , and 3.48 × 10 g·ha N O for the fall trial and 3.11 × 10 g·ha of CO , 2.95 × 10 g·ha of CH , and 1.47 × 10 g·ha N O after the spring reapplication trial were observed. The N O net cumulative flux represents 0.595% of nitrogen applied in swine manure for the fall trial.

关键词: Climate change     Emissions     Greenhouse gases     Land application     Swine manure    

GREENHOUSE GAS AND AMMONIA EMISSION MITIGATION PRIORITIES FOR UK POLICY TARGETS

《农业科学与工程前沿(英文)》 2023年 第10卷 第2期   页码 268-280 doi: 10.15302/J-FASE-2023495

摘要:

● An expert survey highlighted the most effective strategies for GHG and ammonia mitigation.

关键词: agriculture     ammonia     greenhouse gas     mitigation     net zero    

Carbon dioxide sequestration in petrochemical industries with the aim of reduction in greenhouse gas

Maryam Takht Ravanchi, Saeed Sahebdelfar, Farnaz Tahriri Zangeneh

《化学科学与工程前沿(英文)》 2011年 第5卷 第2期   页码 173-178 doi: 10.1007/s11705-010-0562-1

摘要: The mitigation of greenhouse gas emissions to acceptable levels is arguably the greatest environmental challenge these days. Vast utilization of fossil fuels and forest destruction are main causes of CO increase in the atmosphere. Carbon dioxide sequestration that consists of separation, transportation and utilization or storage of CO , is one way for reduction of its emission, in which the most costly section is separation. Different methods can be used for carbon dioxide separation such as absorption, membrane separation, adsorption and cryogenic distillation. Economic, technical and environmental issues should be considered in selection of the technology for particular application. Carbon dioxide concentration, temperature, pressure and flow rate are influential operating parameters in the selection of the appropriate separation method. Nowadays, absorption is the worldwide industrial separation method. New researches are focused on developing new stable solvents and efficient column configuration with suitable internals to minimize pressure drop. Membrane separation and adsorption (PSA type) are other long-term alternatives that can increase separation efficiency and decrease separation cost. The level of energy consumption in various separation methods are in the order: chemical absorption>physical absorption>membrane separation. Because of high investment costs, current separation technologies are suitable for large concentrated sources. In the present paper, different processes for carbon dioxide separation are investigated and compared. Available technologies and commercial plants for CO sequestration are provided.

关键词: carbon dioxide     greenhouse effect     separation     membrane     absorption     adsorption    

Pilot-scale studies of domestic wastewater treatment by typical constructed wetlands and their greenhouse

Chaoxiang LIU, Kaiqin XU, Ryuhei INAMORI, Yuhei INAMORI, Yoshitaka EBIE, Jie LIAO,

《环境科学与工程前沿(英文)》 2009年 第3卷 第4期   页码 477-482 doi: 10.1007/s11783-009-0155-8

摘要: Three typical constructed wetlands (CWs) including Vertical Flow (VF), Free Water Surface (FWS), and Subsurface Flow (SF), and combined VF-SF-FWS constructed wetlands were investigated for the treatment of domestic wastewater with low C/N ratio. The performance of nutrient removal and the characteristics of greenhouse gas emissions, such as CH and NO, from these CWs were compared. The results indicated that the four types of CWs had high removal efficiencies for organic matter and suspended solid (SS). The combined wetland also showed a comparatively good performance for nitrogen and phosphorus removal, and the removal efficiencies for total nitrogen (TN) and total phosphorus (TP) were 81.3% and 84.5%, respectively. The combined CWs had a comparative lower global warming potential. The FWS CW had the highest tendency to emit CH and led to a higher global warming potential among the four types of CWs, which was about 586 mg CO/m·h.

关键词: global warming potential     methane     nitrous oxide     low C/N ratio     nitrogen     phosphorus    

标题 作者 时间 类型 操作

A comprehensive review of greenhouse shapes and its applications

Ravinder Kumar SAHDEV,Ashwani Kumar DHINGRA,Mahesh KUMAR

期刊论文

A new meshless approach for bending analysis of thin plates with arbitrary shapes and boundary conditions

期刊论文

Probabilistic stability of uncertain composite plates and stochastic irregularity in their buckling mode shapes

期刊论文

Catalyst particle shapes and pore structure engineering for hydrodesulfurization and hydrodenitrogenation

期刊论文

An ANN-exhaustive-listing method for optimization of multiple building shapes and envelope properties

Yaolin LIN, Wei YANG

期刊论文

A novel structural modification to eliminate the early coupling between bending and torsional mode shapes

Nazim Abdul NARIMAN

期刊论文

Analyzing the energy intensity and greenhouse gas emission of Canadian oil sands crude upgrading through

Anton ALVAREZ-MAJMUTOV,Jinwen CHEN

期刊论文

Systematical strategies for wastewater treatment and the generated wastes and greenhouse gases in China

Jingbo GUO, Fang MA, Yuanyuan QU, Ang LI, Liang WANG

期刊论文

Transportation: meeting the dual challenges of achieving energy security and reducing greenhouse gas

Michael Quanlu WANG, Hong HUO

期刊论文

Accounting greenhouse gas emissions of food consumption between urban and rural residents in China: a

期刊论文

PROPOSED INNOVATION REFORM MODEL FOR THE MINERAL NITROGEN FERTILIZER INDUSTRY IN CHINA TO REDUCE GREENHOUSE

期刊论文

Field scale measurement of greenhouse gas emissions from land applied swine manure

Devin L. Maurer, Jacek A. Koziel, Kelsey Bruning

期刊论文

GREENHOUSE GAS AND AMMONIA EMISSION MITIGATION PRIORITIES FOR UK POLICY TARGETS

期刊论文

Carbon dioxide sequestration in petrochemical industries with the aim of reduction in greenhouse gas

Maryam Takht Ravanchi, Saeed Sahebdelfar, Farnaz Tahriri Zangeneh

期刊论文

Pilot-scale studies of domestic wastewater treatment by typical constructed wetlands and their greenhouse

Chaoxiang LIU, Kaiqin XU, Ryuhei INAMORI, Yuhei INAMORI, Yoshitaka EBIE, Jie LIAO,

期刊论文