31 |
Time-varying impacts of green credit on carbon productivity in China: New evidence from a non-parametric panel data modelHou, P., Luo, S., Liu, S., Tan, Yong, Roubaud, D. 16 July 2024 (has links)
Yes / In the context of global climate change threatening human survival, and in a post-pandemic era that advocates for a global green and low-carbon economic recovery, conducting an in-depth analysis to assess whether green f inance can effectively support low-carbon economic development from a dynamic perspective is crucial. Unlike existing research, which focuses solely on the average effects of green credit (GC) on carbon productivity (CP), we introduce a non-parametric panel data model to investigate GC’s impact on CP across 30 provinces in China from 2003 to 2021, verifying a significant time-varying effect. Specifically, during the first phase (2003–2008), GC negatively impacted CP. In the second phase (2009–2014), this negative influence gradually diminished and transformed into a positive effect. In the third phase (2015–2021), GC continued to positively influence CP, although this effect became insignificant during the pandemic. Further subgroup analysis reveals that in the regions with low environmental regulations, GC did not significantly boost CP throughout the sample period. In contrast, in the regions with high environmental regulations, GC’s positive effect persisted in the mid to late stages of the sample period. Additionally, compared to the regions with low levels of marketization, the impact of GC on CP was more pronounced in highly marketized regions. This indicates that the promoting effect of GC on CP depends on strong support from environmental regulations and well-functioning market mechanisms. By adopting a non-parametric approach, this study reveals variations in the impact of GC on CP across different stages and under the influence of the pandemic shock, offering new insights into the relationship between GC and China’s CP. / The full-text of this article will be released for public view at the end of the publisher embargo on 15 May 2025.
|
32 |
Análise paramétrica da infiltração e sua influência na estabilidade de taludes em solo não saturado / Parametric analysis of infiltration and its influence on unsaturated soil slope stabilitySantos, Cláudio Rodrigues dos 24 March 2004 (has links)
Apresenta-se um estudo paramétrico acerca da infiltração de água e sua repercussão no Fator de Segurança de talude em solos não saturados. Na análise adota-se um talude de referência com geometria fixada conforme a inclinação típica para taludes em areia argilo siltosa, característica do Centro-Oeste do estado de São Paulo. A análise paramétrica foi desenvolvida a partir de uma simulação de fluxo em regime transiente utilizando o programa SEEP/W, que utiliza o método de elementos finitos, e posteriormente uma análise de estabilidade do talude de referência utilizando o método de Bishop simplificado conforme apresentado no programa SLOPE/W. Foram analisados taludes homogêneos compostos por três diferentes tipos de solo, uma areia, um silte argiloso e uma areia argilo siltosa. Os parâmetros analisados compreendem a curva de retenção de água, a função condutividade hidráulica do solo e a intensidade de precipitação. Verificou-se que a função condutividade hidráulica e a pressão de entrada de ar são os principais determinantes do comportamento da infiltração e conseqüentemente da estabilidade do talude. As simulações de fluxo evidenciaram que os taludes em solos mais arenosos apresentam taxas de infiltração maiores que as apresentadas pelos taludes compostos por solos siltosos. Consequentemente, os escorregamentos ocasionados pela perda da contribuição da sucção para a resistência ao cisalhamento ocorrem primeiramente nos taludes compostos por solos arenosos e posteriormente naqueles compostos por solos siltosos, fato este que pôde ser confirmado pelas análises de estabilidade do talude de referência. / A parametric study is presented about water infiltration and its repercussion in the safety factor of unsaturated soil slopes. In the analysis it is adopted a reference slope with determined geometry according to the typical inclination for slopes in silty clayey sand, characteristic of the mid-western region of São Paulo State, in Brazil. The parametric analysis was developed from a flux simulation in transient regime using the SEEP/W software, which uses the finite elements method, and thereafter, a stability analysis of the reference slope using simplified Bishop method, as presented in the SLOPE/W software. Homogeneous slopes composed by three different types of soil (sand, clayey silt and silty clayey sand) were considered. The analyzed parameters include the water retention curve, the hydraulic conductivity function and the precipitation intensity. It was verified that the hydraulic conductivity function and the air entry value are the main determinants of the infiltration behavior and, subsequently, of the slope stability. The flux simulations have evidenced that coarser soils slopes show higher infiltration rates than the ones presented in finer soil slopes. Consequently, the slides caused by the loss of the suction\'s contribution to shear strength occur primarily in coarser soil slopes than in fine soil slopes, what could be verified in the stability analysis of the reference slope.
|
33 |
Análise paramétrica e dimensionamento de poços de infiltração para fins de drenagem urbana / Parametric analysis and design of infiltration wells for urban drainagePeixoto, Vinicius Carvalho 15 April 2011 (has links)
A combinação entre a falta de planejamento urbano e o crescimento indiscriminado de áreas impermeáveis é responsável pela ocorrência de enchentes em centros urbanos. O emprego de dispositivos de controle do escoamento superficial na fonte geradora, como poços e trincheiras de infiltração, pavimentos permeáveis e jardins de infiltração (rain gardens), é uma alternativa que permite restabelecer o processo de infiltração em áreas urbanas densamente impermeabilizadas. Neste contexto, efetuou-se uma análise paramétrica acerca da influência das funções condutividade hidráulica e das curvas de retenção dos solos no processo de infiltração de água em poços cilíndricos instalados em solos inicialmente não saturados. Para a realização das análises paramétricas, foi empregado o programa SEEP/W do pacote GeoStudio 2004, que utiliza a técnica dos elementos finitos na solução numérica da equação de Richards que rege o fluxo de água em meio não saturado. As análises paramétricas mostraram que o coeficiente de condutividade hidráulica saturada do solo é o parâmetro que apresenta maior relevância no processo de infiltração de água em poços. Com isto, desenvolveu-se uma técnica de dimensionamento de poços de infiltração que permite determinar o volume de água infiltrada em um dado poço em função do tempo de precipitação, do coeficiente de condutividade hidráulica saturada do solo e da área total do poço. Por fim, comparou-se o volume estimado de água infiltrada obtido através da técnica de dimensionamento com o volume medido em um ensaio de infiltração realizado por Lima (2009) em uma trincheira de pequenas dimensões e pôde-se constatar que o a técnica de dimensionamento desenvolvida é consistente com o ensaio de infiltração realizado em campo. / The chief consequence of unplanned urban sprawl is the turning to impervious large tracts of land. Impervious developed areas are prone to floods during heavy rains. Flooding may be mitigated by installation of devices that can control runoff at the source. Examples of control devices are infiltration wells, infiltration trenches, permeable pavement, and rain gardens. By facilitating infiltration, such devices serve to return to the soil below the waterproofed area the waters that would otherwise be lost as runoff, which overloads urban drainage. A study of infiltration wells was conducted through parametric analyses of hydraulic conductivity function and soil-water characteristics curve of unsaturated soils in the process of infiltration. This research used the computer program SEEP/W by GeoStudio 2004 to carry out the parametric analysis. SEEP/W uses the finite element method for the numerical solution of Richards equation, which describes water flow in the unsaturated zone. The parametric analysis showed that the saturated hydraulics conductivity of the soil is the parameter that has greater relevance in the process of infiltration of water into the soil surrounding the wells. Based on the results obtained, a technical procedure was developed to assist the consulting professional to size the infiltration wells. The variables employed in the proposed design procedure consist of time of precipitation, saturated hydraulic conductivity, and total surface area of well. Further, it was compared the estimated volume of infiltrated water obtained through this procedure to the measured volume obtained by Lima (2009) in a small trench. It was observed that the scaling procedure proposed by this work yields results consistent with infiltration field experiments such as that conducted by Lima (2009).
|
34 |
Análise paramétrica e dimensionamento de poços de infiltração para fins de drenagem urbana / Parametric analysis and design of infiltration wells for urban drainageVinicius Carvalho Peixoto 15 April 2011 (has links)
A combinação entre a falta de planejamento urbano e o crescimento indiscriminado de áreas impermeáveis é responsável pela ocorrência de enchentes em centros urbanos. O emprego de dispositivos de controle do escoamento superficial na fonte geradora, como poços e trincheiras de infiltração, pavimentos permeáveis e jardins de infiltração (rain gardens), é uma alternativa que permite restabelecer o processo de infiltração em áreas urbanas densamente impermeabilizadas. Neste contexto, efetuou-se uma análise paramétrica acerca da influência das funções condutividade hidráulica e das curvas de retenção dos solos no processo de infiltração de água em poços cilíndricos instalados em solos inicialmente não saturados. Para a realização das análises paramétricas, foi empregado o programa SEEP/W do pacote GeoStudio 2004, que utiliza a técnica dos elementos finitos na solução numérica da equação de Richards que rege o fluxo de água em meio não saturado. As análises paramétricas mostraram que o coeficiente de condutividade hidráulica saturada do solo é o parâmetro que apresenta maior relevância no processo de infiltração de água em poços. Com isto, desenvolveu-se uma técnica de dimensionamento de poços de infiltração que permite determinar o volume de água infiltrada em um dado poço em função do tempo de precipitação, do coeficiente de condutividade hidráulica saturada do solo e da área total do poço. Por fim, comparou-se o volume estimado de água infiltrada obtido através da técnica de dimensionamento com o volume medido em um ensaio de infiltração realizado por Lima (2009) em uma trincheira de pequenas dimensões e pôde-se constatar que o a técnica de dimensionamento desenvolvida é consistente com o ensaio de infiltração realizado em campo. / The chief consequence of unplanned urban sprawl is the turning to impervious large tracts of land. Impervious developed areas are prone to floods during heavy rains. Flooding may be mitigated by installation of devices that can control runoff at the source. Examples of control devices are infiltration wells, infiltration trenches, permeable pavement, and rain gardens. By facilitating infiltration, such devices serve to return to the soil below the waterproofed area the waters that would otherwise be lost as runoff, which overloads urban drainage. A study of infiltration wells was conducted through parametric analyses of hydraulic conductivity function and soil-water characteristics curve of unsaturated soils in the process of infiltration. This research used the computer program SEEP/W by GeoStudio 2004 to carry out the parametric analysis. SEEP/W uses the finite element method for the numerical solution of Richards equation, which describes water flow in the unsaturated zone. The parametric analysis showed that the saturated hydraulics conductivity of the soil is the parameter that has greater relevance in the process of infiltration of water into the soil surrounding the wells. Based on the results obtained, a technical procedure was developed to assist the consulting professional to size the infiltration wells. The variables employed in the proposed design procedure consist of time of precipitation, saturated hydraulic conductivity, and total surface area of well. Further, it was compared the estimated volume of infiltrated water obtained through this procedure to the measured volume obtained by Lima (2009) in a small trench. It was observed that the scaling procedure proposed by this work yields results consistent with infiltration field experiments such as that conducted by Lima (2009).
|
35 |
Influence of Rock Boundary Conditions on Behaviour of Arched and Flat Cemented Paste Backfill Barricade WallsCheung, Andrew 21 November 2012 (has links)
Current design of cemented paste backfill (CPB) barricades tends to be of unknown conservativeness due to limited understanding of their behaviour. Previous work done to characterize barricade response has not accounted for the effects of the surrounding rock stiffness, which can have significant impact on the development of axial forces which enhance capacity via compressive membrane action.
Parametric analyses were performed with the finite element analysis program Augustus-2 to determine the effects of various material and geometric properties on barricade capacity. Equations based on Timoshenko and Boussinesq solutions were developed to model rock stiffness effects based on boundary material properties. An iterative simulation process was used to account for secondary moment effects as a proof of concept.
It was found that, for a range of typical rock types, barricade capacity varied significantly. The commonly made design assumption of a fully rigid boundary resulted in unconservative overpredictions of strength.
|
36 |
Influence of Rock Boundary Conditions on Behaviour of Arched and Flat Cemented Paste Backfill Barricade WallsCheung, Andrew 21 November 2012 (has links)
Current design of cemented paste backfill (CPB) barricades tends to be of unknown conservativeness due to limited understanding of their behaviour. Previous work done to characterize barricade response has not accounted for the effects of the surrounding rock stiffness, which can have significant impact on the development of axial forces which enhance capacity via compressive membrane action.
Parametric analyses were performed with the finite element analysis program Augustus-2 to determine the effects of various material and geometric properties on barricade capacity. Equations based on Timoshenko and Boussinesq solutions were developed to model rock stiffness effects based on boundary material properties. An iterative simulation process was used to account for secondary moment effects as a proof of concept.
It was found that, for a range of typical rock types, barricade capacity varied significantly. The commonly made design assumption of a fully rigid boundary resulted in unconservative overpredictions of strength.
|
37 |
Statistical Analysis and Modeling of Prostate CancerChan, Yiu Ming 01 January 2013 (has links)
The objective of the present study is to address some important questions related to prostate cancer treatments and survivorship among White and African American men. It is commonly understood that the risk of developing prostate cancer is higher in African American men than the other races. However, using parametric analysis, this study demonstrates that this perception is a "myth" not a "reality". The study further identifies the existence of racial/ethnic disparities by comparing the average mean tumor size, the median of survival time, and the survival function between White and African American men. These results underline the necessity of understanding the role of racial background in working towards improved clinical targeting, and thereby, improving clinical outcomes. Furthermore, parametric survival analysis was performed to estimate the survivorship of white men undergoing different treatments at each stage of prostate cancer. Additionally, to better understand the risk factors (age, tumor size, the interaction between age and tumor size) associated with survival time, an accelerated failure time model was developed that could accurately predict the rates of survivorship of white men at each stage of prostate cancer in accordance with whatever treatment they had received. Finally, the results of parametric survival analysis and the accelerated failure time model are compared among white men undergoing similar treatment at each stage of the disease.
|
38 |
Age Dependent Analysis and Modeling of Prostate Cancer DataBonsu, Nana Osei Mensa 01 January 2013 (has links)
Growth rate of prostate cancer tumor is an important aspect of understanding the natural history of prostate cancer. Using real prostate cancer data from the SEER database with tumor size as a response variable, we have clustered the cancerous tumor sizes into age groups to enhance its analytical behavior. The rate of change of the response variable as a function of age is given for each cluster. Residual analysis attests to the quality of the analytical model and the subject estimates. In addition, we have identified the probability distribution that characterize the behavior of the response variable and proceeded with basic parametric analysis.
There are several remarkable treatment options available for prostate cancer patients. In this present study, we have considered the three commonly used treatment for prostate cancer: radiation therapy, surgery, and combination of surgery and radiation therapy. The study uses data from the SEER database to evaluate and rank the effectiveness of these treatment options using survival analysis in conjunction with basic parametric analysis. The evaluation is based on the stage of the prostate cancer classification.
Improvement in prostate cancer disease can be measured by improvement in its mortality. Also, mortality projection is crucial for policy makers and the financial stability of insurance business. Our research applies a parametric model proposed by Renshaw et al. (1996) to project the force of mortality for prostate cancer. The proposed modeling structure can pick up both age and year effects.
|
39 |
Estudo da producao de sup(57)Co e sup(109)Cd em ciclotronLANDINI, LILIANE 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:44:33Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:57:00Z (GMT). No. of bitstreams: 1
06867.pdf: 6383508 bytes, checksum: d78bad9ca259bf6a60dc4d98d94fc7a3 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
|
40 |
Estudo cinetico da cloracao do silicioSEO, EMILIA S.M. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:42:41Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:01:35Z (GMT). No. of bitstreams: 1
05027.pdf: 12073377 bytes, checksum: 07fdd3a7ed9e60cb7be90d8745f24034 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
|
Page generated in 0.1111 seconds