Work Sanctions Under Welfare Reform: Are They Helping Women Achieve Self-Sufficiency?

The focus of this thesis has been to determine the usable voltage range of carbon-based supercapacitors (SC). Supercapacitors are a relatively new type of capacitors with a vast increase in capacitance compared to capacitors which utilize a dielectric as charge separator. A SC consists of two electrodes and an electrolyte separating the electrodes. The charges are stored by electrostatic forces in the interface between the electrode and the electrolyte, forming the so called electrochemical double-layer (EDL). With porous electrodes the effective surface area of the interfacial zone can be made very large, giving SCs a large storage capacity. The limiting factors of a SC is the decomposition potential of the electrolyte and the decomposition of the electrodes. For commercially manufactured SCs the electrolyte is usually an organic solvent, which has a decomposition potential of up to 2.7-2.8 V. Compared to aqueous electrolytes with a thermodynamic limit of 1.23 V. The drawback of using non-aqueous electrolytes is that they are not environmentally friendly, and they increase the production cost. It is claimed that the voltage range can be up to 1.9 V using aqueous electrolytes. Some researchers have focused on aqueous electrolytes for these reasons. In this thesis two different electrolytes were tested to determine if the voltage range could be extended. The experiments were conducted using a three electrode cell and performing cyclic voltammogram measurements (CV). The carbon electrodes were made of  two different sources of grahite, battery graphite or exfoliated graphite, and nano fibrilated cellulose was added to increase the mechanical stability. The results show that the oxidation potential of the carbon electrode was the positive limit. A usable potential of about 1 V was shown. However, when cycling the electrodes to potentials below the decomposition limit, for hydrogen evolution, interesting effects were seen. A decrease in reaction kinetics, indicating a type of conditioning of the electrode was observed. An increase in charge storage capacitance was also observed when comparing the initial measurements with the final, probably corresponding to an increase in porosity.KEPS projekt Sundsvall Mitt Universite

Extremely low-income households, housing affordability and the Great Recession.

The effects of the Great Recession on housing equity and homeownership have been well-documented. However, we know little about how rental households fared and the efficacy of housing subsidies in addressing affordability gaps. This paper examines the extent to which rental housing became less affordable for Extremely Low-Income (ELI) households - those earning less than 30% of the Area Median Income (AMI). I then run regression models to determine the local characteristics most strongly associated with larger affordability gaps, with a focus on whether housing subsidies are effective at combating such gaps. Rental affordability gaps became more pronounced during the Great Recession. In nearly 70% of the counties in my sample, there was an increase from 2007 to 2010 in the number of ELI households per affordable rental unit. Across the country, the increase was 17%, a dramatic increase in only three years. There is considerable variation across the country, with acute affordability crises often concentrated in the South, particularly Florida. Regression models provide compelling evidence that housing vouchers, public housing, and project-based Section 8 subsidies play an important role in limiting the extent to which large numbers of ELI households are competing for a shortage of low-cost rental units. However, these programmes do not respond quickly to local needs - such as those brought about by the Great Recession. A pilot study where local housing authorities had funding to be more agile and responsive would be an important step toward crafting better policy

Measuring the geography of opportunity

Quantitative segregation research focuses almost exclusively on the spatial sorting of demographic groups. This research largely ignores the structural characteristics of neighborhoods – such as crime, job accessibility, and school quality – that likely help determine important household outcomes. This paper summarizes the research on segregation, neighborhood effects, and concentrated disadvantage, and argues that we should pay more attention to neighborhood structural characteristics, and that the data increasingly exist to include measures of spatial segregation and neighborhood opportunity. The paper concludes with a brief empirical justification for the inclusion of data on neighborhood violence and a discussion on policy applications

Efficient Path Interpolation and Speed Profile Computation for Nonholonomic Mobile Robots

This paper studies path synthesis for nonholonomic mobile robots moving in two-dimensional space. We first address the problem of interpolating paths expressed as sequences of straight line segments, such as those produced by some planning algorithms, into smooth curves that can be followed without stopping. Our solution has the advantage of being simpler than other existing approaches, and has a low computational cost that allows a real-time implementation. It produces discretized paths on which curvature and variation of curvature are bounded at all points, and preserves obstacle clearance. Then, we consider the problem of computing a time-optimal speed profile for such paths. We introduce an algorithm that solves this problem in linear time, and that is able to take into account a broader class of physical constraints than other solutions. Our contributions have been implemented and evaluated in the framework of the Eurobot contest

Low-energy particle radiation environment at synchronous altitude

The degradation of thermal control coatings of satellites due to the effects of low energy charged particles in the space environment is discussed. Data obtained from ATS-5 satellite measurement of proton and electron fluxes are presented. The variations in electron density, proton density, and magnetic activity are presented to show correlations which exist between these space factors

User-friendly mathematical model for the design of sulfate reducing H2/CO2 fed bioreactors

The paper presents three steady-state mathematical models for the design of H2/CO2 fed gas-lift reactors aimed at biological sulfate reduction to remove sulfate from wastewater. Models 1A and 1B are based on heterotrophic sulfate reducing bacteria (HSRB), while Model 2 is based on autotrophic sulfate reducing bacteria (ASRB) as the dominant group of sulfate reducers in the gas-lift reactor. Once the influent wastewater characteristics are known and the desired sulfate removal efficiency is fixed, all models give explicit mathematical relationships to determine the bioreactor volume and the effluent concentrations of substrates and products. The derived explicit relationships make application of the models very easy, fast and no iterative procedures are required. Model simulations show that the size of the H2/CO2 fed gas-lift reactors aimed at biological sulfate removal from wastewater highly depends on the number and type of trophic groups growing in the bioreactor. In particular, if the biological sulfate reduction is performed in a bioreactor where ASRB prevail, the required bioreactor volume is much smaller than that needed with HSRB. This is because ASRB can out-compete methanogenic archarea (MA) for H2 (assuming sulfate concentrations are not limiting), whereas HSRB do not necessarily out-compete MA due to their dependence on homoacetogenic bacteria (HB) for organic carbon. The reactor sizes to reach the same sulfate removal efficiency by HSRB and ASRB are only comparable when methanogenesis is inhibited. Moreover, model results indicate that acetate supply to the reactor influent does not affect the HSRB biomass required in the reactor, but favours the dominance of MA on HB as a consequence of a lower HB requirement for acetate supply