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1.
Environ Sci Pollut Res Int ; 31(14): 21668-21686, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38393572

RESUMO

China, the world's largest consumer and producer of pork in the world, is attracting increasing attention due to the environmental impacts of its pig production. Previous studies seldom comprehensively compare the environmental impacts of the pig production system with different models, resulting in different intensities of environmental impacts. We aim to comprehensively evaluate Chinese pig production with different breeding models and explore a more sustainable way for pig production. We use life cycle assessment (LCA) to evaluate and compare environmental impacts of pig production system with four main breeding models in China from 1998 to 2020: domestic breeding, small-scale breeding, medium-scale breeding, and large-scale breeding. The life cycle encompasses fertilizer production, feed production, feed processing, pig raising, waste treatment, and slaughtering. The impact categories including energy consumption (EN), global warming (GWP), acidification (AP), eutrophication (EU), water use (WD), and land occupation (LO) are expressed with "100 kg live weight of fattening pig at farm gate." The results show that driven by governmental support, growing meat demand, and cost advantage, the scale breeding especially large-scale breeding simultaneously yielded greater net economic benefit and less environmental impact compared to other breeding models especially the domestic breeding. Due to mineral fertilizer application, feed production contributed over 50% of the total environmental impacts. Notably, the composition of feeds exerted significant influence on the environmental impacts arising from fertilizer production and feed processing. Furthermore, attributable to the substantial use of electricity and heat, as well as the concomitant emissions, pig raising contributed the largest GWP, while ranking second in terms of AP and EU. Notably, waste management constituted the third-largest EU, AP, and WD. In addition to promote scale breeding, we put forth several sustainable measures encompassing feed composition, cultivation practices, fertilizer utilization, and waste management for consideration.


Assuntos
Conservação dos Recursos Naturais , Fertilizantes , Animais , Suínos , Fazendas , Aquecimento Global , China
2.
Environ Sci Pollut Res Int ; 31(1): 1212-1225, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38036912

RESUMO

Digital inclusive finance (DIF) has been growing fast in recent years in China, and green technology innovation (GTI) is strongly promoted by the Chinese government. The coordinated development of DIF and GTI is important for China's economic transition to high-quality development. Therefore, utilizing the panel data of 288 prefecture cities from 2011 to 2020 in China, the research evaluates the coupling coordination degree between DIF and GTI (CCD-DG), analyzes spatial-temporal characteristics of CCD-DG, explores its regional disparities and finally analyzes its spatial effects. Results demonstrate that CCD-DG at the prefecture-city level showed a rise from 2011 to 2020, but the degree was only in the stage of basic coordination till 2020, which was mainly driven by the development of DIF in recent years. The regional disparities in CCD-DG remarkably existed but gradually narrowed down during the observation period, which mainly originated from the between-subregions differences as a result of the huge difference in GTI. Additionally, there was a significant spatial spillover effect of CCD-DG and its spatial distribution was roughly consistent with the spatial effect layout. Policy implications based on these results are finally proposed, including formulating policies with local characteristics to promote CCD-DG, emphasizing the discrepancies of CCD-DG between the East and the Northwest, and that within the Northwest and the South, etc.


Assuntos
Governo , China , Cidades , Desenvolvimento Econômico , Tecnologia
3.
Gels ; 9(12)2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38131929

RESUMO

Aerogel is widely recognized as a superinsulating material with great potential for enhancing the thermal insulation performance of building walls. It can be applied in various forms such as aerogel plasters (AP), aerogel fibrous composites (AFC), and aerogel concrete (AC) in practical engineering applications. This study aims to investigate the most efficient application form for maximizing building insulation performance while minimizing the amount of aerogel used. To predict the thermal insulation performance of aerogel-insulated walls, a resistance-capacitance network model integrating the aerogels' effective thermal conductivity model was developed and was validated by comparing it with Fluent simulation software results in terms of surface temperature. Using the validated models, the thermophysical parameters, transient thermal properties, and transmission load were predicted and compared among AP, AFC, and AC walls. The results indicate that using AFC can result in approximately 50% cost savings to achieve the same thermal resistance. After adding a 20 mm thickness of aerogel to the reference wall without aerogel, the AFC wall exhibited the highest improvement in thermal insulation performance, reaching 46.0-53.5%, followed by the AP wall, and then the AC wall, aligning with considerations of microstructural perspectives, thermal resistance distributions, and thermal non-uniformity factors. Therefore, giving priority to AFC use could reduce the required amount of silica aerogel and enhance economic efficiency. These results provide valuable insights for theoretical models and the application of aerogel-insulated walls in building engineering insulation.

4.
Environ Pollut ; 337: 122544, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37709121

RESUMO

The increasing human demand for high-quality animal protein has provided impetus for the development of aquaculture. Chinese mitten crab (Eriocheir sinensis) is a catadromous species rapidly being cultured in China but scientific literature documenting its life cycle environmental and economic consequences remains scarce. This study aims to address this gap by examining the spatio-temporal evolution of crab aquaculture in China since the 2000s and evaluating the environmental and economic characteristics along its life-cycle stages: megalopa, juvenile crab, and adult crab cultivation. The geostatistical analysis shows a more dispersed pattern of crab aquaculture nationally as crab grows, with coastal provinces that have brackish water for megalopa cultivation but wider spatial coverage for juvenile and adult crab cultivation. Our findings reveal that the production of 1 ton of live-weight crab results in 7.65 ton of CO2 equivalent of greenhouse gas emissions, surpassing previous estimates for finfish fish production by approximately 50%. Most environmental pressures occur during the adult crab cultivation stage, with significant contributions from upstream processes such as electricity and feed production. By comparing between different production systems, our study shows that crab aquaculture in lake systems performs better than pond systems in terms of most global environmental impact categories and economic considerations. This work contributes to the existing literature by elucidating the spatio-temporal changes of crab aquaculture boom in China and constructing a representative life cycle data pool that broadens the benchmark knowledge on its environmental and economic characteristics. We highlight the trade-offs between environmental and economic performance as well as the balance between global and local environmental impacts to promote sustainable growth in the aquaculture industry.


Assuntos
Braquiúros , Gases de Efeito Estufa , Animais , Humanos , Aquicultura/métodos , Meio Ambiente , China , Peixes
5.
J Environ Manage ; 340: 117904, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37084647

RESUMO

Nitrogen (N) and phosphorus (P) are two critical nutrients for agroecosystems. In meeting food demands, human use of both nutrients has crossed planetary boundaries for sustainability. Further, there has been a dramatic shift in their relative inputs and outputs, which may generate strong N:P imbalances. Despite enormous efforts on agronomic N and P budgets, the spatio-temporal characteristics of different crop types in using nutrients are unknown as are patterns in the stoichiometric coupling of these nutrients. Thus, we analyzed the annual crop-specific N and P budgets and their stoichiometric relations for producing ten major crops at the provincial level of China during 2004-2018. Results show that, China has generally witnessed excessive N and P input over the past 15 years, with the N balance remaining stable while the P balance increasing by more than 170%, thus resulting in a decline in the N:P mass ratios from 10.9 in 2004 to 3.8 in 2018. Crop-aggregated nutrient use efficiency (NUE) of N has increased by 10% in these years while most crops have shown a decreasing trend of this indicator for P, which reduced NUE of P from 75% to 61% during this period. At the provincial level, the nutrient fluxes of Beijing and Shanghai have obviously declined, while the nutrient fluxes of provinces such as Xinjiang and Inner Mongolia have increased significantly. Although N management has made progress, P management should be further explored in the future due to eutrophication concerns. More importantly, N and P management strategies for sustainable agriculture in China should take account of not only the absolute nutrient use, but also their stoichiometric balance for different crops in different locations.


Assuntos
Agricultura , Produtos Agrícolas , Humanos , China , Agricultura/métodos , Eutrofização , Nutrientes , Nitrogênio/análise , Fósforo/análise , Fertilizantes
6.
Bioengineered ; 12(2): 12167-12178, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34783271

RESUMO

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary liver tumor with increasing incidence worldwide. Metabolic reprogramming caused by metabolic related gene disorders is a prominent hallmark of tumors, among which Glycogen Synthase 2 (GYS2) is the key gene responsible for regulating cellular energy metabolism, and its expression disorders are closely related to various tumors and glycometabolic diseases. However, we still know nothing about its role in ICC. This study is intended to reveal the functional role of GYS2 in the ICC progress and explore the underlying mechanism. Based on the integrated pan-cancer analysis of GYS2 in the GEPIA database, the expression of GYS2 in paired ICC and adjacent non tumor tissues was detected by qPCR. It was found that the expression of GYS2 was significantly down-regulated in ICC. Further analysis showed that its low expression was not only associated with the degree of pathological differentiation, tumor size, microvascular invasion and lymph node metastasis, but also an independent risk factor for unfavorable prognosis. Functional studies have shown that GYS2 overexpression can significantly impair the proliferation, replication, cloning, migration and invasion of cholangiocarcinoma cells, while the silencing GYS2 dramatically promotes the development of the aforementioned phenotypes, the underlying mechanism may be that GYS2 activates the P53 pathway. In conclusions,low GYS2 expression in ICC predicted unfavorable patient outcomes; GYS2 overexpression could significantly impair the proliferation, migration and invasion of cholangiocarcinoma cells via activating the P53 pathway and GYS2 was expected to become a potential therapeutic target for such patients.


Assuntos
Neoplasias dos Ductos Biliares/diagnóstico , Neoplasias dos Ductos Biliares/enzimologia , Colangiocarcinoma/diagnóstico , Colangiocarcinoma/enzimologia , Glicogênio Sintase/metabolismo , Neoplasias dos Ductos Biliares/genética , Neoplasias dos Ductos Biliares/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Colangiocarcinoma/genética , Colangiocarcinoma/patologia , Regulação para Baixo/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Glicogênio Sintase/genética , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Prognóstico , Transdução de Sinais , Proteína Supressora de Tumor p53/metabolismo
7.
Waste Manag ; 135: 70-78, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34478950

RESUMO

A better understanding of the waste of end-of-life batteries from electric vehicles (EVs) is a basis for their sustainable management. This study aims to estimate the waste of end-of-life EV batteries during 2006-2040 in China and to analyze the opportunities and challenges of subsequent utilization, based on a developed numerical model, real market data, and elaborately developed scenarios. The result shows that end-of-life batteries would increase from 0.1 to 7.8 thousand tons during 2012-2018, and then to 1500-3300 thousand tons in 2040. Of the waste streams, around 50% are estimated to be metal materials, representing great opportunities for battery recycling for material recovery. Economically, battery recycling for energy storage is estimated to create more economic benefits compared with that for material recovery solely (147.8 versus 76.9 billion US dollars). However, the supply of end-of-life batteries can hardly meet the demand for renewable energy storage in the near future, and a spatial mismatch of the supply and demand of energy storage capacity exists between the eastern and western regions in China. Accordingly, this study highlights national coordination for the rational layout of the collection, disassembly, and remanufacture facilities for the second use of end-of-life EV batteries in China.


Assuntos
Fontes de Energia Elétrica , Lítio , China , Eletricidade , Reciclagem
8.
J Environ Manage ; 262: 110253, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32250776

RESUMO

Life-cycle assessment (LCA) emphasizes obtaining primary data from an on-site process to reduce uncertainties. However, data of the upstream process from secondary sources also yield significant uncertainties, which have not been drawn enough attention. This study aims to explore the importance of primary data of the upstream process in LCAs. Here, we choose lithium, a key component of lithium-ion (Li-ion) battery, as a case to present a cradle-to-gate LCA for its production by rock-based technology (LRT). Then, we compare the environmental impacts of lithium by LRT with that by brine-based technology (LBT) and the Li-ion battery using lithium by the two methods. The result shows that the impacts of rock-based lithium production are dominated by the leaching process, which has the highest levels of impacts for 8 of 10 environmental categories. Besides, all 10 impact categories of lithium produced by LRT are much larger than that by LBT, with differences up to 60.4 -fold. We also find that the Li-ion battery pack by rock-based lithium offers a 17-32% increase in acidification and global warming potential relative to that by brine-based lithium. Our results contribute by providing the first mass-produced life-cycle inventory of rock-based lithium and showing the importance of primary data of the upstream process in LCAs.


Assuntos
Fontes de Energia Elétrica , Lítio , Meio Ambiente , Íons
9.
Ecol Appl ; 21(7): 2822-32, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22073662

RESUMO

Human activities disturb the long-term phosphorus (P) cycle in nature, whereby the resulting intensive release of P contributes to the eutrophication of surface water. Hence, a detailed understanding of P flow as it relates to socioeconomic systems is essential for effective nutrient management. This study develops a substance-flow-analysis model for P metabolism for the socioeconomic ecosystem of Shucheng County in Anhui Province in central China as a case study. We estimate P flow using data from questionnaires, face-to-face interviews, published literature, and official statistical databases. Our results show that P flow in Shucheng's current socioeconomic system is linear and openly metabolic. The total P input into Shucheng in 2008 reached 12 748 Mg, mainly as P ores and crops. In all, 43.83% of the total P input was exported, and 30.44% was discharged into surface water. More-balanced nutrient management and options for improving nutrient use efficiency are discussed. The quantifiable, science-based methods used in this study may be applied to neighboring regions of central China for sustainable development and water management.


Assuntos
Agricultura/economia , Ecossistema , Fósforo/química , China , Conservação dos Recursos Naturais , Monitoramento Ambiental , Indústrias , Fatores Socioeconômicos , Poluentes Químicos da Água , Poluição Química da Água
10.
J Environ Manage ; 92(8): 2021-8, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21489683

RESUMO

Excessive input of phosphorus into natural water bodies as a result of anthropogenic processes is an escalating factor that leads to eutrophication. Hence, quantifying the pathway of phosphorus throughout the socioeconomic system is essential for the selection of appropriate measures to mitigate phosphorus discharge. The study develops an analytical model of anthropogenic phosphorus flows within a socioeconomic system based on substance flow analysis. The model consists of five major subsystems: the phosphorous chemical industry, agriculture, animal feeding, human consumption, and waste management. The results show that the total input and output of phosphorus in Chaohu City over 2008 are 8517.70 ton (t) and 4682.76 t, respectively. The estimation of phosphorus discharged into local surface water is 544.22 t, which primarily comes from agriculture (391.99 t, 72.03%), followed by large-scale farming (55.70 t, 10.23%), rural consumption (56.81 t, 10.44%), urban consumption (30.42 t, 5.59%), and waste management (9.30 t, 1.71%). Intensive input of fertilizers in agricultural practices was identified as the most important source of phosphorus load on local surface water. Hence, we propose that the eutrophication of local water bodies could be addressed by optimizing local industrial structure, developing ecological and organic-based agriculture, and improving waste collection and disposal practices.


Assuntos
Cidades , Eutrofização , Modelos Teóricos , Fósforo/análise , Poluentes Químicos da Água/análise , Poluição da Água/prevenção & controle , Agricultura , Ração Animal , Indústria Química , Economia , Fatores Socioeconômicos , Gerenciamento de Resíduos , Movimentos da Água
11.
J Theor Biol ; 248(4): 727-35, 2007 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-17669436

RESUMO

Penguins, mostly live in the extremely cold Antarctic, are known to have feathers and down, which are light weight, compact and extremely efficient in preventing heat loss. Nevertheless, the mechanisms of heat transfer through the penguin feathers and down, and how the unique characteristics of penguin feathers and down make them such good thermal insulators are not fully understood. In this paper, an integrated model of heat transfer through the penguin feathers and down is developed and computed using finite volume method, with the geometrical structure of the barbules being considered. Monte-Carlo method is adopted to determine the radiative absorption and emission constant in the integrated model. The effective thermal conductance of penguin feathers and down computed from our model compared well with the experimentally measured value reported in the literature. Three models (penguin model, random fibre model (fibre radius=3microm) and random fibre model (fibre radius=10microm)) are further simulated and compared. Results showed that the relative small radius of the barbules of penguin feather and their geometrical structure are responsible for the reduction of heat loss in cold environment.


Assuntos
Regulação da Temperatura Corporal/fisiologia , Plumas/fisiologia , Modelos Biológicos , Spheniscidae/fisiologia , Animais , Biometria , Método de Monte Carlo
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