Development and validation of a drinking water temperature model in domestic drinking water supply systems

Domestic drinking water supply systems (DDWSs) are the final step in the delivery of drinking water to consumers. Temperature is one of the rate-controlling parameters for many chemical and microbiological processes and is, therefore, considered as a surrogate parameter for water quality processes. In this study, a mathematical model is presented that predicts temperature dynamics of the drinking water in DDWSs. A full-scale DDWS resembling a conventional system was built and run according to one year of stochastic demands with a time step of 10 s. The drinking water temperature was measured at each point-of-use in the systems and the data-set was used for model validation. The temperature model adequately reproduced the temperature profiles, both in cold and hot water lines, in the full-scale DDWS. The model showed that inlet water temperature and ambient temperature have a large effect on the water temperature in the DDWSs.     

Comparison of conventional and higher-resolution reduced-FOV diffusion-weighted imaging of breast tissue

Magnetic Resonance Materials in Physics, Biology and Medicine - Reduced FOV-diffusion-weighted imaging (rFOV-DWI) allows for acquisition of a tissue region without back-folding, and may have better...     

The Schumpeterian entrepreneur: a review of the empirical evidence on the antecedents,behaviour and consequences of innovative entrepreneurship

Abstract

Innovative entrepreneurship is considered an important pillar for economic development and has sparked a lively discussion in academia and practice alike. Oftentimes, however, the debate is not sufficiently grounded on solid empirical evidence. The academic literature is growing but very scattered and is separated into several disciplines. We provide a summary that takes stock of the academic knowledge about innovative entrepreneurship and summarizes the evidence from 102 empirical studies published in the primary economics and management journals on the antecedents, behavior, and consequences of innovative entrepreneurship. Based on this state-of-the-art literature review, directions for future research are discussed.     

The Effect of Surface Roughness on the Corrosion Properties of Type AISI 304 Stainless Steel in Diluted NaCl and Urban Rain Solution

Due to their good corrosion resistance, favorable mechanical properties, and reasonable price regarding their excellent properties, austenitic stainless steels have, over recent decades, become one of the alloys that are increasingly used in civil engineering and building, as well as for specific architectural purposes. Architects often design stainless steel exterior elements with higher surface roughnesses, which are not resistant to corrosion processes. The aim of this work was to investigate the influence of different types of surface finishes to stainless steel of quality AISI 304 on the corrosion properties of this steel. In order to achieve this goal, electrochemical tests were performed on different surface finishes in two different environments: in an NaCl aqueous solution, and in simulated urban rain which contained no chlorides. In addition to the electrochemical methods used, surface roughness was also measured, and XPS surface analyses were performed. The results of the investigation showed that surface roughness affects the growth of the passive layer in urban rain significantly; however, the growth of such a film is retarded in the case of the NaCl aqueous solution. Based on the results of the performed analyses, it was found that, in the NaCl solution, the pitting potential depended strongly upon the surface roughness and the surface finish, but this was not true for the samples tested in urban rain.     

Hydrothermal processing of rice husks: effects of severity on product distribution

BACKGROUND: Treatment in aqueous media (hydrothermal or autohydrolysis reactions) is an environmentally friendly technology for fractionating lignocellulosic materials. Rice husks were subjected to hydrothermal processing under a variety of operational conditions to cause the selective breakdown of xylan chains, in order to assess the effects of reaction severity on the distribution of reaction products. RESULTS: The effects of severity (measured by the severity factor, R₀) on the concentrations of the major autohydrolysis products (monosaccharides, xylo‐ and glucooligosaccharides, xylooligosaccharide substituents, acetic acid, acid‐soluble lignin and elemental nitrogen) were assessed. The interrelationship between the severity of treatment and molecular weight distribution was established by high‐performance size‐exclusion chromatography. Selected samples were subjected to refining treatments as ethyl acetate extraction and ion exchange for refining purposes, and the concentrates were assayed by high‐performance anion‐exchange chromatography and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry. CONCLUSIONS The protein equivalent of the products present in liquors accounted for 43 to 51% of the protein present in the raw rice husks. The concentrations of glucose (derived from starchy material) and arabinose (split from the xylan backbone) were fairly constant with severity. Even in treatments at low severity, high molecular weight compounds derived from xylan accounted for a limited part of the stoichiometric amount. Operating under harsh conditions, about 50% of the total xylan‐derived compounds corresponded to fractions with a degree of polymerization (DP) < 9. After refining, saccharides accounted for more than 90% of the non‐volatile components of the sample. The refined products showed a series of xylose oligomers up to about DP 13, and a series of acetylated xylose oligomers up to about DP 15. Copyright © 2008 Society of Chemical Industry     

Theory-based policy evaluation of 20 energy efficiency instruments

Realizing a 20% energy efficiency improvement in Europe by 2020 requires the introduction of good new energy efficiency policies as well as strengthening and enforcing the existing policies. This raises the question: what characterizes good and effective energy efficiency policies and their implementation? Systematic ex post evaluation of energy efficiency policies can reveal factors determining not only what works and what does not but also explain why. Ex post evaluation of 20 energy efficiency policy instruments applied across different sectors and countries in Europe among others showed that ex post evaluation does not yet have a high priority among policy makers: Often, quantitative targets and clear timeframes are lacking, and monitoring information is not collected on a regular basis. Our analysis, however, did reveal some general factors in the process of design and implementation of policy instruments that appear as important including (1) existence of clear goals and a mandate for the implementing organization, (2) the ability to balance and combine flexibility and continuity, (3) the involvement of stakeholders, and (4) the ability to adapt to and integrate adjacent policies or develop consistent policy packages. The analysis was performed using a uniform methodology called “theory-based policy evaluation”. The general principle behind this approach is that a likely theory is drawn up on the program’s various steps of logic of intervention to achieve its targeted impact in terms of energy efficiency improvement. The approach has several benefits over other ex post evaluation methods because (1) the whole policy implementation process is evaluated and the focus is not just on the final impacts, (2) through the development of indicators for each step in the implementation process, the “successes and failures” can be determined to the greatest extent possible, and (3) by applying this approach, we not only learn whether policies are successful or not but also why they succeeded or failed and how they can be improved.     

Estimation of measles vaccine efficacy and critical vaccination coverage in a highly vaccinated population

Measles is a highly infectious disease that has been targeted for elimination from four WHO regions. Whether and under which conditions this goal is feasible is, however, uncertain since outbreaks have been documented in populations with high vaccination coverage (more than 90%). Here, we use the example of a large outbreak in a German public school to show how estimates of key epidemiological parameters such as the basic reproduction number (R₀), vaccine efficacy (VE_S) and critical vaccination coverage (p_c) can be obtained from partially observed outbreaks in highly vaccinated populations. Our analyses rely on Bayesian methods of inference based on the final size distribution of outbreak size, and use data which are easily collected. For the German public school the analyses indicate that the basic reproduction number of measles is higher than previously thought (, 95% credible interval: 23.6–40.4), that the vaccine is highly effective in preventing infection (, 95% credible interval: 0.993–0.999), and that a vaccination coverage in excess of 95 per cent may be necessary to achieve herd immunity (, 95% credible interval: 0.961–0.978). We discuss the implications for measles elimination from highly vaccinated populations.