A two-stage, two-organism process for biohydrogen from glucose

H2 can potentially be produced in a two-stage biological process: the fermentation of glucose by Escherichia coli HD701 and the photofermentation of the residual medium by Rhodobacter sphaeroides O.U. 001. In a typical batch fermentation, E. coli consumed glucose and produced H2, organic end-products and biomass. Organic end-products and residual glucose were removed during subsequent photofermentation by R. sphaeroides, with associated growth and neutralization of pH. However, photoproduction of H2 did not occur during photofermentation of the residual liquor per se due to the presence of fixed nitrogen compounds. Nevertheless, this two-stage approach could be applied to dispose of sugar-containing industrial wastes, H2 being used for on-site power generation

Integrating dark and light biohydrogen production strategies: towards the hydrogen economy

Biological methods of hydrogen production are preferable to chemical methods because of the possibility to use sunlight, CO2 and organic wastes as substrates for environmentally benign conversions, under moderate conditions. By combining different microorganisms with different capabilities, the individual strengths of each may be exploited and their weaknesses overcome. Mechanisms of bio-hydrogen production are described and strategies for their integration are discussed. Dual systems can be\ud divided broadly into wholly light-driven systems (with microalgae/cyanobacteria as the 1st stage) and partially light-driven systems (with a dark, fermentative initial reaction). Review and evaluation of published data suggests that the latter type of system holds greater promise for industrial application. This is because the calculated land area required for a wholly light-driven dual system would be too large for either centralised (macro-) or decentralised(micro-) energy generation. The potential contribution to the hydrogen economy of partially light-driven dual systems is overviewed alongside that of other biofuels such as bio-methane and bio-ethanol

Biomass-supported catalysts on Desulfovibrio desulfuricans and Rhodobacter sphaeroides

A Rhodobacter sphaeroides-supported dried, ground palladium catalyst (‘‘Rs-Pd(0)’’) was compared with a Desulfovibrio desulfuricans-supported catalyst (‘‘Dd-Pd(0)’’)and with unsupported palladium metal particles made by reduction under H2 (‘‘Chem-Pd(0)’’). Cell surface-located clusters of Pd(0) nanoparticles were detected on both D. desulfuricans and R. sphaeroides but the size and location of deposits differed among comparably loaded preparations.\ud \ud These differences may underlie the observation of different activities of Dd-Pd(0) and Rs-Pd(0) when compared with respect to their ability to promote hydrogen release from hypophosphite and to catalyze chloride release from chlorinated aromatic compounds. Dd-Pd(0) was more effective in the reductive dehalogenation of polychlorinated biphenyls (PCBs), whereas Rs-Pd(0) was more effective in the initial dehalogenation of pentachlorophenol (PCP) although the rate of chloride release from PCP was comparable with both preparations after 2 h

Geographic profiling in Nazi Berlin: fact and fiction

Geographic profiling uses the locations of connected crime sites to make inferences about the probable location of the offender’s ‘anchor point’ (usually a home, but sometimes a workplace). We show how the basic ideas of the method were used in a Gestapo investigation that formed the basis of a classic German novel about domestic resistance to the Nazis during the Second World War. We use modern techniques to re-analyse this case, and show that these successfully locate the Berlin home address of Otto and Elise Hampel, who had distributed hundreds of anti-Nazi postcards, after analysing just 34 of the 214 incidents that took place before their arrest. Our study provides the first empirical evidence to support the suggestion that analysis of minor terrorism-related acts such as graffiti and theft could be used to help locate terrorist bases before more serious incidents occur

An Implementation Approach and Performance Analysis of Image Sensor Based Multilateral Indoor Localization and Navigation System

Optical camera communication (OCC) exhibits considerable importance nowadays in various indoor camera based services such as smart home and robot-based automation. An android smart phone camera that is mounted on a mobile robot (MR) offers a uniform communication distance when the camera remains at the same level that can reduce the communication error rate. Indoor mobile robot navigation (MRN) is considered to be a promising OCC application in which the white light emitting diodes (LEDs) and an MR camera are used as transmitters and receiver respectively. Positioning is a key issue in MRN systems in terms of accuracy, data rate, and distance. We propose an indoor navigation and positioning combined algorithm and further evaluate its performance. An android application is developed to support data acquisition from multiple simultaneous transmitter links. Experimentally, we received data from four links which are required to ensure a higher positioning accuracy

Spatial targeting of infectious disease control: identifying multiple, unknown sources

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A New Vehicle Localization Scheme Based on Combined Optical Camera Communication and Photogrammetry

The demand for autonomous vehicles is increasing gradually owing to their enormous potential benefits. However, several challenges, such as vehicle localization, are involved in the development of autonomous vehicles. A simple and secure algorithm for vehicle positioning is proposed herein without massively modifying the existing transportation infrastructure. For vehicle localization, vehicles on the road are classified into two categories: host vehicles (HVs) are the ones used to estimate other vehicles' positions and forwarding vehicles (FVs) are the ones that move in front of the HVs. The FV transmits modulated data from the tail (or back) light, and the camera of the HV receives that signal using optical camera communication (OCC). In addition, the streetlight (SL) data are considered to ensure the position accuracy of the HV. Determining the HV position minimizes the relative position variation between the HV and FV. Using photogrammetry, the distance between FV or SL and the camera of the HV is calculated by measuring the occupied image area on the image sensor. Comparing the change in distance between HV and SLs with the change in distance between HV and FV, the positions of FVs are determined. The performance of the proposed technique is analyzed, and the results indicate a significant improvement in performance. The experimental distance measurement validated the feasibility of the proposed scheme

Hydrothermal hydrolysis of starch with CO2 and detoxification of the hydrolysates with activated carbon for bio-hydrogen fermentation.

The imminent use of hydrogen as an energy vector establishes the need for sustainable production technologies based on renewable resources. Starch is an abundant renewable resource suitable for bio-hydrogen generation. It was hypothesised that starch hydrolysates from a large (250 mL) hydrothermal reactor could support bioH2 fermentation without inhibition by toxic byproducts.\ud \ud Starch was hydrolysed at high concentrations (40 200 g.L-1) in hot compressed water (HCW) with CO2 at 30 bar in a 250 mL reactor, the largest so far for polysaccharide hydrolysis, at 180 235 °C, 15 min. Hydrolysates were detoxified with activated carbon (AC) and tested in biohydrogen fermentations. The maximum yield of glucose was 548 g.kg starch 1 carbon at 200 °C. 5 hydroxymethyl furfural, the main fermentation inhibitor, was removed by AC to support 70% more hydrogen production than the untreated hydrolysates. The potential utilization of starch hydrolysates from HCW treatment for upscaled fermentations is promising