scholarly journals A review of systems modelling for local sustainability

Author(s):  
Enayat A Moallemi ◽  
Edoardo Bertone ◽  
Sibel Eker ◽  
Lei Gao ◽  
Katrina Szetey ◽  
...  
1996 ◽  
Vol 34 (5-6) ◽  
pp. 67-74 ◽  
Author(s):  
D. Orhon ◽  
S. Sözen ◽  
N. Artan

For single-sludge denitrification systems, modelling of anoxic reactors currently uses the kinetics of aerobic heterotrophic growth together with a correction factor for anoxic conditions. This coefficient is computed on the basis of respirometric measurements with the assumption that the heterotrophic yield remains the same under aerobic and anoxic coditions. The paper provides the conceptual proof that the yield coefficient is significantly lower for the anoxic growth on the basis of the energetics of the related metabolic processes. This is used for the interpretation of the very high values for the correction factor experimentally determined for a number of industrial wastewaters. A default value for the anoxic heterotrophic yield coefficient is calculated for domestic sewage and compatible wastewaters and proposed for similar evaluations.


Urban Science ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 24
Author(s):  
Gordon F. Mulligan ◽  
John I. Carruthers

This paper examines the joint adjustment of population and employment numbers across America’s metropolitan areas during the period 1990–2015. Current levels of both are estimated, for 10 year periods, using their lagged (own and cross) levels and eight other lagged variables. Population is affected by both human and natural amenities and employment by wages, patents, and other attributes of the workforce. This paper questions the conventional interpretation of the adjustment process by using geographically weighted regression (GWR) instead of standard linear (OLS, 2GLS) regression. Here the various estimates are all local, so the long-run equilibrium solutions for the adjustment process vary over space. Convergence no longer indicates a stable universal solution but instead involves a mix of stable and unstable local solutions. Local sustainability becomes an issue when making projections because employment can quickly lead or lag population in some metropolitan labor markets.


2021 ◽  
pp. 107808742199524
Author(s):  
Zhilin Liu ◽  
Jie Wang ◽  
Craig W. Thomas

An increasing volume of literature has sought to identify factors that motivate cities to pursue sustainability and adopt climate policies. However, most empirical studies were done in Western countries, where relatively high local autonomy and low pressure on industrial growth create conditions for spontaneous policy innovations in sustainability. This paper uses China’s Low-Carbon City Pilot Program as a case to investigate motivations for local sustainability actions in an authoritarian context. Our event history analyses confirm the effects of multi-level governance on local sustainability initiatives in China, particularly horizontal competition across jurisdictions, priorities and preferences of upper-level authorities, as well as local determinants including leadership, capacity, politics, and environmental stress. The findings contribute to the comparative urban governance scholarship by highlighting the unique feature of “experimentation under hierarchy” in shaping urban sustainability policymaking in China.


Sign in / Sign up

Export Citation Format

Share Document