Optimal barrier subdivision for Kramers' escape rate

We examine the effect of subdividing the potential barrier along the reaction coordinate on Kramers' escape rate for a model potential. Using the known supersymmetric potential approach, we show the existence of an optimal number of subdivisions that maximises the rate.Comment: 8 pages, 3 figures, To appear in Pramana - J. Phys, Indi

The Ethiopian Environmental Regime versus International Standards: Policy, Legal, and Institutional Frameworks

No Abstrac

Effect of Landauer's blowtorch on the equilibration rate in a bistable potential

Kinetic aspect of Landauer's blowtorch effect is investigated for a model double-well potential with localized heating. Using the supersymmetric approach, we derive an approximate analytical expression for the equilibration rate as function of the strength, width and the position of the hot zone, and the barrier height. We find that the presence of the hot zone enhances the equilibration rate, which is found to be an increasing function of the strength and width of the hot zone. Our calculations also reveal an intriguing result, namely, that placing the hot zone away from the top of the potential barrier enhances the rate more than when it is placed close to it. A physically plausible explanation for this is attempted. The above analytical results are borne out by detailed numerical solution of the associated Smoluchowski equation for the inhomogeneous medium.Comment: 15 pages in LaTeX format and 6 figures in postscript E-Mail : [email protected] [email protected]

Is Income Inequality Endogenous in Regional Growth?

This study focuses on testing the relationship between income inequality and growth within U.S. counties, and the channels through which such effects are observed. The study tests three hypotheses: (1) income inequality has an inverse relationship with growth; (2) regional growth adjustments are the channels through which the inequality and growth are equilibrated; and (3) income inequality is endogenous to regional growth and its adjustment. Results, based on a system of equations estimation, confirm the hypotheses that income inequality has a growth dampening effect; income inequality is endogenous to regional growth and growth adjustment; and the channels through which income inequality determines growth are regional growth adjustments, such as migration and regional adjustment in job and income growth. Results have numerous policy implications: (1) to the extent that income inequality is endogenous, its equilibrium level can be internally determined within a regional growth process; (2) to the extent that traditional income inequality mitigating policies have indirect effect on overall regional growth, they may have unintended indirect effects on income inequality; and (3) to the extent that regional growth adjustment also equilibrates income inequality, such forces can be utilized as policy instruments to mitigate income inequality, and its growth dampening effects hence forth.Income inequality, economic growth, Gini coefficient, growth modeling, population change, per capita income, Community/Rural/Urban Development, Public Economics, I32, J15, O18, P25, R11, R23, R25, R51, R53, R58,

Nutritional Status of Adolescent Girls from Rural Communities of Tigray, Northern Ethiopia

Background: Addressing the nutritional needs of adolescents could be an important step towards breaking the vicious cycle of intergenerational malnutrition. Objective: Assess nutritional status of rural adolescent girls. Design: Cross-sectional. Methods: Anthropometric and socio-demographic information from 211 adolescent girls representing 650 randomly selected households from thirteen communities in Tigray was used in data analysis. Height-for-age and BMI-for-age were compared to the 2007 WHO growth reference. Data were analyzed using SAS, Version 9.1. Results: None of the households reported access to adolescent micronutrient supplementation. The girls were shorter and thinner than the 2007 WHO reference population. The cross-sectional prevalence of stunting and thinness were 26.5% and 58.3%, respectively. Lack of latrine facilities was significantly associated with stunting (p = 0.0033) and thinness (p <0.0001). Age was strong predictor of stunting (r(2) = 0.8838, p <0.0001) and thinness (r(2) = 0.3324, p <0.0001). Conclusion: Undernutrition was prevalent among the girls. Strategies to improve the nutritional status of girls need to go beyond the conventional maternal and child health care programs to reach girls before conception to break the intergenerational cycle of malnutrition. Further, carefully designed longitudinal studies are needed to identify the reasons for poor growth throughout the period of adolescence in this population. [Ethiop. J. Health Dev. 2009; 23(1):5-11

Stress control of frictional hangingwall accommodation above thrust ramps

Experimental models are used to study the stress control of frictional hangingwall accomodation above rigid flat-ramp-flat footwalls. Hangingwall accommodation involves shear or kink-band nucleation above the lower fault bend and migration of these as the hangingwalls climb over the underthrusting footwall. The kinkbands change shape and localise to thrusts as they migrate over the flat-ramp-flat footwall. When the shear stress to gravity stress ratio is low the thrusts reactivate to normal faults. With increase in the shear stress to gravity stress ratio reactivation of the kink bands was by tensile failure, at the upper fault bend. The models show that by changing the strength of materials deforming under otherwise similar conditions it is possible to study the geometry of frictional hangingwall accommodation, at different scales. In nature, hangingwall accommodation by thrust nucleation above thrust ramps and their subsequent normal reactivation may be anticipated in frictional sediments at shallow crustal levels, where temperatures and pressures are low

Land use land cover dynamics at Bilate Alaba sub-watershed, southern Ethiopia

This study was intended to detect land use/land cover changes over 44 years in the Bilate Alaba Subwatersed, Southern Ethiopia. Four Landsat images (1972, 1986, 2008 and 2017) were used to as inputs to produce four land cover maps of the subwatershed; ERDAS imagine and ArcGIS software were utilized to accomplish the analysis. In the period between 1972 to1986 cultivated and settlement showed an incremental change by 280.91 and 71.43 ha respectively, while bare land and shrub &amp; grass land decreased by 225.26 and 140.25 ha respectively. In the period 1986 to 2008 cultivated and bare land increased by 105.13 and 52.90 ha while forest and shrub &amp; grass land decreased by 103.41 and 50.84 ha respectively. Between 2008 and 2017 settlement and bare land increased by 83.20 and 65.54 ha respectively while shrub &amp; grass land and forest land decreased by 112.59 and 46.16 ha respectively. The results showed that cultivated land and settlement land expanded by 67.38% and 532% respectively whereas forest land, shrub land &amp;grass land declined by 66.35%, 18.36% respectively over the analysis period (1972-2017). There should be appropriate rural land use/management policy by identifying proper land for specific purpose so that degraded lands would not put under cultivation.Keywords: Land use, Land cover, GIS, Landsa

Is Income Inequality Endogenous in Regional Growth?

This study focuses on testing the relationship between income inequality and growth within U.S. counties, and the channels through which such effects are observed. Based on a system of equations estimation, the empirical results confirm the hypotheses that income inequality has a growth dampening effect; income inequality is endogenous to regional growth and growth adjustment; and the channels through which income inequality determines growth are regional growth adjustments, such as migration and regional adjustment in job and income growth. Results have numerous policy implications to the extent that: (1) that income inequality is endogenous, its equilibrium level can be internally determined within a regional growth process; (2) traditional income inequality mitigating policies have indirect effect on overall regional growth, they may have unintended indirect effects on income inequality; and (3) regional growth adjustment also equilibrates income inequality, such forces can be utilized as policy instruments to mitigate income inequality, and its growth dampening effects hence forth