515 research outputs found
New applications and performance of bioelectrochemical systems
Bioelectrochemical systems (BESs) are emerging technologies which use microorganisms to catalyze the reactions at the anode and/or cathode. BES research is advancing rapidly, and a whole range of applications using different electron donors and acceptors has already been developed. In this mini review, we focus on technological aspects of the expanding application of BESs. We will analyze the anode and cathode half-reactions in terms of their standard and actual potential and report the overpotentials of these half-reactions by comparing the reported potentials with their theoretical potentials. When combining anodes with cathodes in a BES, new bottlenecks and opportunities arise. For application of BESs, it is crucial to lower the internal energy losses and increase productivity at the same time. Membranes are a crucial element to obtain high efficiencies and pure products but increase the internal resistance of BESs. The comparison between production of fuels and chemicals in BESs and in present production processes should gain more attention in future BES research. By making this comparison, it will become clear if the scope of BESs can and should be further developed into the field of biorefineries
Economic Efficiency of Fisheries Management Measures in an Innovative Evaluation Framework Perspective
Microbial solar cells: applying photosynthetic and electrochemically active organisms
Microbial solar cells (MSCs) are recently developed technologies utilizing solar energy to produce electricity or chemicals. MSCs use photoautotrophic microorganisms or higher plants to harvest solar energy, and use electrochemically active microorganisms in the bioelectrochemical system to generate electrical current. Here, we review the principles and performance of various MSCs, in an effort to identify the most promising systems as well as the bottlenecks and potential solutions towards „real life. MSC application. We give an outlook on future applications based on the intrinsic advantages of MSCs, showcasing specifically how these living energy systems can facilitate the development of an electricity-producing green roof.This is a "Post-Print" accepted manuscript, which has been published in
"Trends in Biotechnology".
This version is distributed under the Creative Commons Attribution 3.0 Netherlands License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Please cite this publication as follows:
2011 Trends in Biotechnology Microbial solar cells: applying photosynthetic and electrochemically active organisms. David P.B.T.B. Strik, Ruud A. Timmers, Marjolein Helder, Kirsten J.J. Steinbusch, Hubertus V.M. Hamelers, , Cees J.N. Buisman. Trends in Biotechnology 29 (1), 41-49
You can download the published version at:
http://dx.doi.org/10.1016/j.tibtech.2010.10.00
Monitoring settling and consolidation of fluid mud in a laboratory using ultrasonic measurements
Ultrasound measurements are routinely used to evaluate the safe depth for ships navigation - nautical depth - at waterways and ports using single-beam dual-frequency echo-sounders. The nautical depth is routinely defined by suspension density in the range of 1100–1300 kg/m3 in the mud layer. While ultrasound measurements have a weak sensitivity to density variations, calibration is always needed to convert ultrasound measurements into reliable indicators for nautical depth levels in the mud layers using densely distributed density rheological in-situ measurements. We present a laboratory ultrasonic transmission experiment to monitor the fluid mud’s settling and consolidation processes using a sample from the Port of Rotterdam. We use P- and S-wave ultrasonic transducers in the frequency range between 200 to 1000 kHz. Our results show that the P-wave velocities slightly increase during the consolidation and settling process while the P-wave amplitudes decrease. On the other hand, we observe a high S-wave velocity that increases together with amplitudes over time. The P- and S-wave amplitude and S-wave velocity variation over time correlate well with the mud average density variation. The presented results can be very useful for fluid-mud monitoring at a lab scale, besides possible utilization for large-scale monitoring field campaigns
Progress on catastrophic health spending in 133 countries: a retrospective observational study
Background The goal of universal health coverage (UHC) requires inter alia that families who get needed health care do not suffer undue financial hardship as a result. This can be measured by the percentage of people in households whose out-of-pocket health expenditures are large relative to their income or consumption. We aimed to estimate the global incidence of catastrophic health spending, trends between 2000 and 2010, and associations between catastrophic health spending and macroeconomic and health system variables at the country level. Methods We did a retrospective observational study of health spending using data obtained from household surveys. Of 1566 potentially suitable household surveys, 553 passed quality checks, covering 133 countries between 1984 and 2015. We defined health spending as catastrophic when it exceeded 10% or 25% of household consumption. We estimated global incidence by aggregating up from every country, using a survey for the year in question when available, and interpolation and model-based estimates otherwise. We used multiple regression to explore the relation between a country’s incidence of catastrophic spending and gross domestic product (GDP) per person, the Gini coefficient for income inequality, and the share of total health expenditure spent by social security funds, other government agencies, private insurance schemes, and non-profit institutions. Findings The global incidence of catastrophic spending at the 10% threshold was estimated as 9·7% in 2000, 11·4% in 2005, and 11·7% in 2010. Globally, 808 million people in 2010 incurred catastrophic health spending. Across 94 countries with two or more survey datapoints, the population-weighted median annual rate of change of catastrophic payment incidence was positive whatever catastrophic payment incidence measure was used. Incidence of catastrophic payments was correlated positively with GDP per person and the share of GDP spent on health, and incidence correlated negatively with the share of total health spending channelled through social security funds and other government agencies. Interpretation The proportion of the population that is supposed to be covered by health insurance schemes or by national or subnational health services is a poor indicator of financial protection. Increasing the share of GDP spent on health is not sufficient to reduce catastrophic payment incidence; rather, what is required is increasing the share of total health expenditure that is prepaid, particularly through taxes and mandatory contributions
Progress on catastrophic health spending in 133 countries: a retrospective observational study
Background The goal of universal health coverage (UHC) requires inter alia that families who get needed health care do not suffer undue financial hardship as a result. This can be measured by the percentage of people in households whose out-of-pocket health expenditures are large relative to their income or consumption. We aimed to estimate the global incidence of catastrophic health spending, trends between 2000 and 2010, and associations between catastrophic health spending and macroeconomic and health system variables at the country level. Methods We did a retrospective observational study of health spending using data obtained from household surveys. Of 1566 potentially suitable household surveys, 553 passed quality checks, covering 133 countries between 1984 and 2015. We defined health spending as catastrophic when it exceeded 10% or 25% of household consumption. We estimated global incidence by aggregating up from every country, using a survey for the year in question when available, and interpolation and model-based estimates otherwise. We used multiple regression to explore the relation between a country’s incidence of catastrophic spending and gross domestic product (GDP) per person, the Gini coefficient for income inequality, and the share of total health expenditure spent by social security funds, other government agencies, private insurance schemes, and non-profit institutions. Findings The global incidence of catastrophic spending at the 10% threshold was estimated as 9·7% in 2000, 11·4% in 2005, and 11·7% in 2010. Globally, 808 million people in 2010 incurred catastrophic health spending. Across 94 countries with two or more survey datapoints, the population-weighted median annual rate of change of catastrophic payment incidence was positive whatever catastrophic payment incidence measure was used. Incidence of catastrophic payments was correlated positively with GDP per person and the share of GDP spent on health, and incidence correlated negatively with the share of total health spending channelled through social security funds and other government agencies. Interpretation The proportion of the population that is supposed to be covered by health insurance schemes or by national or subnational health services is a poor indicator of financial protection. Increasing the share of GDP spent on health is not sufficient to reduce catastrophic payment incidence; rather, what is required is increasing the share of total health expenditure that is prepaid, particularly through taxes and mandatory contributions
Poliovirus-specific memory immunity in seronegative elderly people does not protect against virus excretion.
BACKGROUND: Dutch people born between 1925 and 1945 were ineligible for vaccination with the inactivated poliovirus vaccine (IPV) introduced in 1957 and may have escaped natural infection because of reduced poliovirus circulation. We examined whether people with low or undetectable antibody levels are susceptible to infection and whether memory immunity provides protection against virus excretion. METHODS: A total of 429 elderly participants were challenged with monovalent oral poliovirus vaccine (type 1 or 3) and followed for 8 weeks. Immune responses and virus excretion were compared for 4 groups, defined on the basis of seronegativity for poliovirus type 1 or 3, natural immunity, and IPV-induced immunity. RESULTS: On the basis of the rapidity of the antibody response and the absence of immunoglobulin M, we saw clear evidence of memory immune responses in 33% of the participants without detectable antibodies against poliovirus type 1 and in 5% of the participants without detectable antibodies against poliovirus type 3. Fecal virus-excretion patterns were not significantly different for seronegative participants, regardless of whether they showed evidence of memory immunity. CONCLUSIONS: Rapid antibody responses after challenge with oral polio vaccine provide evidence for poliovirus-specific memory immunity in seronegative elderly people. However, in contrast to preexisting immunity, memory immunity does not protect against virus excretion. These results have important implications for the poliomyelitis-eradication initiative, in particular for future immunization policies after eradication has been achieved
Clinical Practice Variation Needs to be Considered in Cost-Effectiveness Analyses
Background and Objective: The cost-effectiveness of clinical interventions is often assessed using current care as the comparator, with national guidelines as a proxy. However, this comparison is inadequate when clinical practice differs from guidelines, or when clinical practice differs between hospitals. We examined the degree of variation in the way patients w
Effect of process conditions on the performance of a dual-reactor biodesulfurization process
The biotechnological gas desulfurization process under haloalkaline conditions is widely applied for removal of toxic H2S from sour gas streams. In this process H2S is biologically oxidized into elemental sulfur. Recently, the process has been extended with an anaerobic process step (dual-reactor line-up), increasing the selectivity for elemental sulfur (S8) from ~85–97% and decreasing the formation of (thio)sulfate. It was also found that biological sulfide uptake took place in the anaerobic bioreactor. In order to apply this process in industry, more insight is needed of the effect of the process conditions on the process performance. The effect of the process conditions HRT and sulfide concentration in the anaerobic bioreactor and pH on the overall product selectivities and on biological sulfide uptake in the anaerobic bioreactor were investigated. 7 experiments were performed in a pilot-scale biodesulfurization set-up. In all experiments, high selectivities (>95%) for S8 formation were obtained, except when the pH in the aerated bioreactor was increased from 8.5 to 9.1 (selectivity of 88%). Furthermore, biological sulfide uptake in the anaerobic bioreactor increased at higher sulfide concentrations and at higher pH. We hypothesize the biological sulfide uptake under anaerobic conditions is related to polysulfide formation. Our results increase the understanding how to control biological sulfide conversion in the dual-reactor biodesulfurization process
Foster parent stress as key factor relating to foster children’s mental health: a 1-year prospective longitudinal study
Development Psychopathology in context: schoolEducation and Child StudiesDevelopment Psychopathology in context: clinical settingsDevelopment Psychopathology in context: famil
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