bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of land use at a landscape scale on bumblebee nest density and survival
Authors: Goulson Dave , Lepais Olivier , O’Connor Stephanie , Osborne Juliet L. , Sanderson Roy A. , Cussans John , Goffe Louis , Darvill Ben
Published: October 2010

1. We have little idea how landscape‐scale factors influence the success of wild bumblebee nests over time. Here for the first time we use molecular markers to estimate within‐season changes in the numbers of nests.

2. Workers of two bumblebee species were sampled in an arable landscape in late May–June and late July–August, and the numbers of nests represented in each sample were estimated. We compare the methods available to estimate nest number from such samples and conclude that methods which allow for heterogeneity in the probability of capture of nests provide the best fit to our data. Changes in numbers of nests at the two time points were used to infer nest survival.

3. The two bee species appeared to differ markedly in survival over time, with estimates of 45% of nests surviving for Bombus lapidarius and 91% for B. pascuorum. However, our data suggest that the foraging range of B. pascuorum may be greater in late season, which would lead us to overestimate nest survival in this species. Differential survival may also reflect differences in phenology between the two species.

4. The land use class which had the most consistent effects on nest number and survival was gardens; for B. lapidarius, the area of gardens within a 750 and 1000 m radius positively influenced nest survival, while for B. pascuorum, the number of nests in late samples was higher at sites with more gardens within a 500 and 750‐m radius. For B. pascuorum, the area of grassland within a 250 and 500‐m radius also positively influenced nest number in late samples, probably because this is the preferred nesting habitat for this species.

5. The importance of gardens is in accordance with previous studies which suggest that they now provide a stronghold for bumblebees in an otherwise impoverished agricultural environment; furthermore, our data suggest that the positive influence of gardens on bumblebee populations can spill over at least 1 km into surrounding farmland.

6. Synthesis and applications. The substantial effects that even small areas of local resources such as rough grassland or clover leys can have on bumblebee nest numbers and survival is of clear relevance for the design of pollinator management strategies.
Linking modelling, monitoring and management: an integrated approach to controlling overabundant wildlife
Authors: Chee Yung En , Wintle Brendan A.
Published: October 2010

1. Overabundant wildlife can cause economic and ecological damage. Therefore population control typically seeks to maintain species’ abundance within desired control limits. Efficient control requires targets, methods for estimating population size before and after control, and reliable means of forecasting population size. Demographic stochasticity, environmental variability and model uncertainty complicate these tasks. Monitoring provides critical feedback in the control process, yet examples of integrated monitoring and management are scarce.

2. We developed an integrated Bayesian population modelling and monitoring algorithm to assist with dynamic cull control of an overabundant population. We describe components of the control algorithm and their combination to produce a structured, sequential prescription for implementing control of a kangaroo population. We demonstrate its application within a single management year and evaluate its performance over a multi‐year horizon under a range of scenarios reflecting uncertainties about population dynamics.

3. Simulation testing of the algorithm demonstrates that it provides a coherent, flexible, efficient and robust basis for managing population control. It is coherent in that connections between management objectives, models and operating rules are explicit and logically integrated. It is flexible in that the management objectives can be freely varied. It is both cost and operationally efficient because: (i) it avoids the need for an expensive, dedicated sampling process to estimate population size prior to culling; (ii) a relatively small number of culls produces reasonable population size estimates and (iii) the estimation by removal process enables direct assessment of whether control has been achieved. Lastly, it is robust because even when there is substantial uncertainty about system state and dynamics, the algorithm performs well at keeping the population under control over the duration of the management horizon.

4. Synthesis and applications. We provide a general and flexible framework for integrated monitoring and culling when the objective is to keep a species’ abundance within control limits. Our framework explicitly deals with uncertainty arising from demographic stochasticity, ecological complexity and lack of knowledge, and provides the foundation for maximizing efficiency and cost‐effectiveness of control operations. Our approach could be applied in any instances where control is effected via culling.
Close encounters of the third order kind
Authors: Angell Chris , Brown Lynne , Forster Tonia , Trevarrow Nigel , Wheeler John
Published: October 2010

This article describes an exercise developed for assessing trainee family therapists' practice at the end of a placement year in a manner consistent with the third‐order positioning the trainees were endeavouring to adopt in their practice. Evaluation by the trainees confirmed that the exercise had provided them with a significant opportunity to co‐construct with the supervisors their practice learning and future learning goals.
Manipulation of feedback expectancy and valence induces negative and positive reward prediction error signals manifest in event‐related brain potentials
Authors: Pfabigan Daniela M. , Alexopoulos Johanna , Bauer Herbert , Sailer Uta
Published: October 2010

The feedback‐related negativity (FRN) has been hypothesized to be most sensitive to unexpected negative feedback. The present study investigated feedback expectancy and valence using a probabilistic gambling paradigm where subjects encountered expected or unexpected positive and negative feedback outcomes. In line with previous studies, FRN amplitude reflected a negative reward prediction error, but to a minor extent also a positive reward prediction error. Moreover, the P300 amplitude was largest after unexpected feedback, irrespective of valence. We propose to interpret the FRN in terms of a reinforcement learning signal which is detecting mismatch between internal and external representations indexed by the ACC to extract motivationally salient outcomes.
Developing and Evaluating Complex Healthcare Interventions in Geriatrics: The Use of the Medical Research Council Framework Exemplified on a Complex Fall Prevention Intervention
Authors: Faes Miriam C. , Reelick Miriam F. , Esselink Rianne A. , Rikkert Marcel G. Olde
Published: October 2010

Geriatrics focuses on a variety of multiorgan problems in a heterogeneous older population. Therefore, most geriatric healthcare interventions are complex interventions. The UK Medical Research Council (MRC) has developed a framework to systematically design, evaluate, and implement complex interventions. This article provides an overview of this framework and illustrates its use in geriatrics by showing how it was used to develop and evaluate a fall prevention intervention. The consecutive phases of the framework are described:

Phase I: Development. This phase began with a literature review, which provided the existing evidence and the theoretical understanding of the process of change. This understanding was further developed through focus groups with experts and interviews with patients and caregivers. The intervention was modeled using qualitative testing of the preliminary intervention through focus groups and through the completion of Delphi surveys by independent specialists.

Phase II: Feasibility and piloting. In this phase, a pilot study was conducted in a group of patients and caregivers. The feasibility of the intervention and evaluation was also discussed in focus groups of participants and instructors.

Phase III: Evaluation. The information from phases I and II shaped the design of a randomized controlled trial to test the effectiveness of the intervention.

Phase IV: Dissemination. The purpose of the final phase is to examine the implementation of the intervention into practice.

The MRC framework provides an innovative and useful methodology for the development and evaluation of complex geriatric interventions that deserves greater dissemination and implementation.
Novel chalcones and 1,3,5‐triphenyl‐2‐pyrazoline derivatives as antibacterial agents
Authors: Sivakumar Ponnurengam Malliappan , Ganesan Suresh , Veluchamy Prabhawathi , Doble Mukesh
Published: October 2010

Novel sixteen chalcones and thirteen 1,3,5‐triphenyl‐2‐pyrazolines were synthesized and characterized using FT‐IR, HR‐Mass, NMR (1H‐NMR, 13C‐NMR, 135 DEPT, 1H–1H CoSY and 1H and 13C CoSY) and XRD. These compounds were evaluated for their antibacterial activity against six micro‐organisms, namely Bacillus subtilis NCIM 2718, Staphylococcus aureus NCIM 5021, Salmonella typhi NCIM 2501, Enterobacter aerogenes NCIM 5139, Pseudomonas aeruginosa NCIM 5029, and Proteus vulgaris NCIM 2813 by twofold dilution method using resazurin as the indicator dye. In the case of chalcones, compounds with hydroxyl and bromo substitutions in the B‐ring favor activity and benzyloxy substitution irrespective of its position in the A‐ring. In the case of 1,3,5‐triphenyl‐2‐pyrazolines, chloro substitution in the A‐ring favors activity. Hydrophilic/lipophilic balance of the compounds plays a major role in their antibacterial activity.
Understanding
Interior Ballistic Processes in a Flash Tube
Authors: Houim Ryan
W. , Kuo Kenneth
K.
Published: October 2010

Vented flash tubes have often been used in the ignition train of medium and large caliber weapon systems. Despite their long history of ballistic usage, there are undesirable features associated with uneven venting of the combustion products. Pressure measurements at various locations from the flash tube have shown severe variations with time, which is associated with spatially nonuniform mass discharging rate from the vent holes. Measured pressure profiles in the flash tube show counterintuitive, nonmonotonic pressure distributions with the lowest pressure in the middle of the venting section of the flash tube. A model of the flash tube venting process was developed to explain these phenomena using modern, high-order numerical schemes. Source terms accounting for mass addition from the black powder pellets, mass loss through the vent holes, wall friction, differential area changes, and volume changes from surface regression of black powder pellets were fully coupled in the model. The numerical results of this model reproduced the severe pressure variations and nonmonotonic pressure profiles observed in experiments. In general, they are caused by gas dynamic effects from a slowly moving normal shock wave in the middle portion of the venting section of the flash tube. As the driving pressure from the burning black powder pellets changes, the location of the normal shock wave jumps from one vent hole set to another, producing pressure variations observed in experiments. The physical understanding gained from this model solution has provided guidance for achieving more uniform mass discharging rate by varying the vent hole sizes as a function of distance along the flash tube.
Experimental Measure of Parameters: The Johnson–Cook Material Model of Extruded Mg–Gd–Y Series Alloy
Authors: Yafu Fan , Qu-dong Wang , Jun-sheng Ning , Jie Chen , Wei Ji
Published: October 2010

This paper introduces a method to determine the material constants for Johnson–Cook model of an as-extruded Mg–Gd–Y series alloy by quasistatic tests on Instron 1251 and Hopkinson bar experiment at room and elevated temperatures. The results indicate that the thermal softening exponent of the current magnesium alloy is as high as 3.05, which is obviously higher than that of most metal materials, such as steel and tungsten. High thermal softening exponent usually means high energy absorption efficiency, and the comparison of the dynamic stress-strain curves between ZK60 and Mg–Gd–Y series alloy indeed indicates that the energy absorption efficiency of the Mg–Gd–Y series alloy is higher than that of ZK60. Additionally, high energy absorption efficiency makes the Mg–Gd–Y series alloy exhibit more excellent antipenetration performance than that of 7A52 aluminum alloy at equal areal density condition.
Annealing Effect on the Shape Memory Properties of Amorphous NiTi Thin Films
Authors: Satoh Gen , Birnbaum Andrew , Yao Y. Lawrence
Published: October 2010

Thin film shape memory alloys have recently become a promising material for the actuation of devices on the microscale such as micropumps and microvalves. Their utilization, however, has been limited due to the difficulty in tailoring their properties for different applications. Control over the transformation temperatures as well as mechanical and shape memory properties is required to enable their widespread use. This study examines the effects of heat treatment time and temperature on the properties of amorphous, Ti-rich NiTi thin films on silicon substrates. The effects on the transformation temperatures are investigated through the use of temperature dependent optical microscopy and temperature dependent X-ray diffraction. The indentation modulus and hardness, as well as dissipated energy and depth recovery, are obtained through nanoindentation and atomic force microscopy. The role of microstructure and composition in altering both the mechanical and shape memory properties of the films is discussed.
Energy Savings Certificate Markets: Opportunities and Implementation Barriers
Authors: Friedman Barry , Bird Lori , Barbose Galen
Published: October 2010

Early experiences with energy savings certificates (ESCs) have revealed their merits and the challenges associated with them. While in the United States ESC markets have yet to gain significant traction, lessons can be drawn from early experiences in the states of Connecticut and New York, as well as from established markets in Italy, France, and elsewhere. The staying power of European examples demonstrates that ESCs can help initiate more efficiency projects. This article compares ESCs with renewable energy certificates (RECs), looks at the unique opportunities and challenges they present, and reviews solutions and best practices demonstrated by early ESC markets. Three major potential ESC market types are also reviewed: compliance, voluntary, and carbon. Additionally, factors that will benefit ESC markets in the United States are examined: new state EEPS policies, public interest in tools to mitigate climate change, and the growing interest in a voluntary market for ESCs.
Experimental Study on a Solar Water Heater Using Supercritical Carbon Dioxide as Working Fluid
Authors: Yamaguchi H. , Zhang X. R. , Sawada N. , Suzuki H. , Ueda H.
Published: October 2010

In this paper, a solar water heater using supercritical carbon dioxide as working fluid is experimentally studied. The sloar water heater is based on a natural convective supercritical CO2 flow. In the present study, an experimental set-up is designed and tested in order to obtain a basic knowledge on this solar water heater. The obtained results show that the natural convective flow is well induced even in winter, the lowest level of solar radiation condition. Furthermore, collector efficiency is measured at above 86.0%. More theoretical investigations are needed to be carried out to make clear about its mechanism etc.
The Role of State Policy in Renewable Energy Development
Authors: Brown Doris Elizabeth , Busche Sarah , Hockett Stephen , McLaren Loring Joyce
Published: October 2010

State policies can support renewable energy development by driving markets, providing certainty in the investment market, and incorporating the external benefits of the technologies into cost/benefit calculations. Using statistical analyses and policy design best practices, this paper quantifies the impact of state-level policies on renewable energy development in order to better understand the role of policy on development and inform policy makers on the policy mechanisms that provide maximum benefit. The results include the identification of connections between state policies and renewable energy development, as well as a discussion placing state policy efforts in context with other factors that influence the development of renewable energy (e.g. federal policy, resource availability, technology cost, public acceptance).
Thermal Analysis of a Solar Hot Water System and a Stock Tank
Authors: Moaveni Saeed
Published: October 2010

During the cold winter months in the Midwestern States, a common problem that many livestock farmers face is to prevent the cattle drinking water, in a stock tank, from freezing. There are commercial water heating systems that consist of drinking fountains, submersible, or floating heaters. However, these units have typically high initial and operating costs. In this paper, we present the analysis and design of a low cost solar system that are made with tractor inner tubes and other readily available materials. Car and tractor inner tubes make good solar collectors because of their mechanical strength and thermophysical properties. The low cost solution reported here could also be used to address warm water supply and or space heating needs in developing countries. In this paper, the transient thermal response of wooden stock tanks with Fourier numbers around 0.01 is considered. Exact analytical solutions in the form of infinite series are used. The product solution of a cylinder and a plane wall is used to model the stock tank. Moreover, given the small Fourier number, a series of numerical experiments were performed to determine the number of terms that must be retained from the infinite series solutions to obtain accurate results. A theoretical model for the solar collector was also developed, and a series of physical experiments were performed to verify the theoretical models of the stock tank and the collector. The experimental results show that theoretical models, developed in this paper, predict the thermal behaviors of the collector and the stock tank well.
Catalothermionic Power Generator Based on Internal Electron Emission in Ni/SiC Heterojunction Nanostructures
Authors: Karpov Eduard G. , Nedrygailov Ievgen I.
Published: October 2010

We report on the unusual properties of single-faced SiC metal-semiconductor heterojunction nanostructures manifested by the ability to atalyze the hydrogen oxidation reaction, and also maintain internal electron emission over the Schottky barriers. As a result a stationary current has been detected in the preheated nanostructure when exposed to the oxyhydrogen gas mixture flux. The structures maintain both the non-adiabatic and electron-phonon channels of energy transfer, and the results of studies indicate the possibility for a very efficient conversion of chemical energy released in the catalytic oxidation of hydrogen into electricity.
An Experimental Study on the Performance and Emission Characteristics of Jatropha Biodiesel Fuelled CI Engine
Authors: Palit Samiddha , Mandal Bijan Kumar , Ghosh Sudip , Bhowal Arup Jyoti
Published: October 2010

A twin cylinder, constant speed, direct injection CI (diesel) engine was run on jatropha biodiesel and diesel fuel blends. The engine was directly coupled to a hydraulic dynamometer whose load was varied by adjusting load wheel on the top of the engine. The test results were recorded for pure diesel, pure biodiesel (B100) and different diesel/biodiesel blends. The performance characteristics shows that brake specific fuel consumption (BSFC) decreases rapidly with increase of load up to 4.0 to 4.5 kW (55% to 62% of full load) and then decreases slowly. This result also indicates that BSFC increases when the percentage of biodiesel in the blends is increased. Brake thermal efficiency also increases from high biodiesel blends to pure diesel fuel. Each fuel curve shows maximum efficiency reaches at the load range of 5.0 to 5.5 kW (68% to 75% of full load). Pure diesel has maximum efficiency 29.6%, where as pure biodiesel has maximum efficiency of 21.2%. The exhaust gas temperature increases with the load for all fuel blends. Pure biodiesel gives higher exhaust temperature (320°C) than pure diesel (260°C). The exhaust gas temperature increases with the higher percentage of biodiesel blends in different fuel blends. The probable reason for that is biodiesel contains oxygen atoms which make the combustion process complete and hence more energy is released. In respect of emission characteristics, carbon mono-oxide (CO) and hydrocarbon emissions are improved with the addition of biodiesel to diesel. But these emissions increase with the increase of load for all fuel blends. NOx emission increases with load as well as percentage of blending of biodiesel in the diesel fuel.
Analytical Study on a Vaned Type Novel Air Turbine for Different Conditions of Casing and Rotor Diameters
Authors: Singh Bharat Raj , Singh Onkar
Published: October 2010

Greater utilization of hydrocarbon fuel in the transport sector is causing serious challenges to maintaining depletion of oil resources and also causing environmental and ecological imbalances. This makes it imperative to lay major thrust upon the search of alternative energy sources. Atmospheric air also offers one of the cost effective energy conversion system. The compressed air can be utilized as potential zero pollution working fluid for producing shaft work in the air turbine prime-mover for light vehicle. This paper details the mathematical modeling and performance evaluation of a small capacity compressed air driven vaned type novel air turbine. Effect of impingement and expansion action of high pressure air for different dimensional situations of casing and rotor diameters of the turbine have been considered and analyzed here. Study shows that the impingement work has significant contribution in total work output and varies from 2.4% to 16.8%, when other parameters like injection angle and vane angle are kept constant at 22.5° and 36° respectively and injection pressure varies from 2 to 6 bars. It is also concluded that the expansion work as well as total work is optimum when casing diameter (D) and rotor diameter (d) are 90 mm and 85 mm respectively.
Desalination and Long-Haul Water Transfer: A Case Study of the Energy-Water Nexus in Texas
Authors: Stillwell Ashlynn S. , King Carey W. , Webber Michael E.
Published: October 2010

Energy and water are interrelated. We use water for energy, for example to cool thermoelectric power generation and produce liquid fuels. Conversely, we use energy for the collection, treatment, disinfection, and distribution of water and wastewater. In the water sector, strain on existing water supplies, population growth, and the push toward stricter water and wastewater treatment standards potentially leads to more energy-intensive water. Treating water to more stringent potable standards requires additional energy beyond conventional treatment. Additionally, as existing water supplies become increasingly strained in some locations, water planners turn to alternative options to quench cities’ thirst. Among these options for inland cities is desalination of seawater followed by long-haul water transfer. Though many desalination technologies exist to treat seawater to potable standards, reverse osmosis membranes are the most common technology in use because of their cost-effectiveness and productivity as compared with more traditional techniques such as multi-effect distillation. [1] However, the high pressures required for reverse osmosis make desalination a very energy-intensive water supply option. The subsequent conveyance of desalinated water through long-haul pipelines also requires large amounts of energy. Even for local water production, 85% of the energy required for standard surface water treatment goes toward water distribution, and so adding in long-haul will only increase this requirement. [2] To examine desalination and long-haul transfer as a drinking water supply option, Texas was chosen as a test-bed with desalination near Houston and long-haul transfer to the rapidly-growing Dallas-Fort Worth metroplex. Various pipeline routes were modeled to simulate options for long-haul desalinated water transfer. Elevation change over the route of the long-haul transfer pipeline was determined using a digital elevation model of the state of Texas. These elevation data were then used to calculate energy requirements for water pumping with standard assumptions for pump performance, efficiency, and rating. Combining these energy requirements with the energy demands for desalination provides an estimate of this option as a water supply for Dallas-Fort Worth. Results suggest that desalination and long-haul transfer as a drinking water supply is 9 to 23 times more energy-intensive per unit of water than conventional treatment of local surface water sources, an increase of 230 to 630 megawatt-hours per day for 20 million gallons. Ensuring adequate water supplies for the future is important, as is developing these water supplies in a sustainable manner. The energy-intensity of desalination and long-haul transfer as a drinking water supply suggests this option is not a sustainable water or energy policy decision if other less energy-intensive options exist.
Transients of Polymer Electrolyte Fuel Cell and Hydrogen Tank
Authors: Wang Yun , Yang Xiaoguang
Published: October 2010

This paper seeks to develop 3D dynamic models for polymer electrolyte fuel cells (PEFCs) and hydrogen tanks, respectively. The dynamic model of PEFCs consists of multiple layers of a single PEFC and couples the various dynamic mechanisms in fuel cells, such as electrochemical double-layer discharging/charging, species transport, heat transfer, and membrane water uptake. The one of hydrogen tanks includes a 3D description of the hydride kinetics coupled with mass/heat transport in the hydrogen tank. Transient of fuel cell during step change in current is simulated. Dynamic responses of the cell voltage and heat generation rate are discussed. Hydrogen absorption process in the tank is considered. Temperature, reaction rate and heat rejection in the fuel tank are presented. Efforts are also made to discuss the coupling of these two systems in practice and associated issues.
Optimized Reactants Mixture and Products Hydrolysis in the Manganese Oxide Thermochemical Cycle
Authors: Varsano Francesca , Bellusci Mariangela , Alvani Carlo , La Barbera Aurelio , Padella Franco , Seralessandri Luca
Published: October 2010

A novel system composed by an aqueous slurry prepared by MnO and NaOH mixture was tested for the hydrogen production in the sodium manganese oxide thermochemical cycle. The hydrogen evolution occurs at lower temperature than conventional mixtures utilized in the cycle. Experiments performed in a Temperature Programmed Desorption/Reaction apparatus (TPD/TPR) have evidenced hydrogen production around 500°C. The hydrolysis step of α-NaMnO2 has been studied and the importance to conduct hydrolysis reaction under inert gas is discussed. A manganese disproportion mechanism is hypothesized to explain the appearance of manganese (II) and manganese (IV) containing phases.
Materials for Compact Thermal Energy Storage: A New IEA Joint SHC/ECES Task
Authors: Bakker Marco , van Helden Wim G. J. , Hauer Andreas
Published: October 2010

A new IEA Task has recently been initiated to develop new storage materials. This Task is implemented as a Joint Task between the Solar Heating and Cooling (SHC) and Energy Conservation through Energy Storage (ECES) Implementing Agreements, and is entitled “IEA SHC/ECES 42/24: Compact thermal energy storage: material development for system integration”. The objective of this Task is to develop advanced materials for compact storage systems, suitable not only for solar thermal systems, but also for other renewable heating and cooling applications such as solar cooling, micro-cogeneration, biomass, or heat pumps. The Task will cover phase change materials, thermochemical and sorption materials, and composite materials and nanostructures, and will include activities such as material development, analysis, and engineering, numerical modelling of materials and systems, development of storage components and systems, and development of standards and test methods. The main added value of this Task is to combine the knowledge of experts from materials science as well as solar/renewable heating and energy conservation. The Task has officially started on January 1, 2009, and will last for four years.
Policy Incentives, Barriers and Recommendations for Biogas Production
Authors: Cuellar Amanda D. , Webber Michael E.
Published: October 2010

Biogas is a mixture of predominantly carbon dioxide and methane that is formed from the anaerobic decomposition of organic materials. It is also a high-quality fuel that can be used in most natural gas applications such as home heating or electricity generation or scrubbed and sold into the gas grid. In the United States the production of biogas from animal manure alone represents an enormous potential energy resource, on the order of 0.9 quadrillion BTU (quad) annually, or nearly 1% of total US energy consumption. Biogas from the wastewater treatment sector in the US could provide another 1.5 billion kWh (or 5 trillion BTU). Despite the promise of this resource as a renewable, low-carbon source of energy, as of 2007 only 125 functioning biogas operations using manure exist in the US. These facilities produced 290 GWh (0.001 quad) of energy in 2007, which accounts for 0.001% of annual energy consumption in the United States and one thousandth of the nation’s biogas potential. In addition, only 15% of the wastewater treatment flow in the US produces biogas that is used as a source of energy; the rest of the wastewater flows either do not produce biogas at all, or produce biogas that is wastefully flared instead of captured for heat or power. In contrast, Sweden currently produces 0.3% of their annual energy usage from biogas, primarily from the wastewater treatment sector. This report analyzes the policy incentives and barriers that exist for the production and utilization of biogas as well as the policy and institutional factors that have contributed to Sweden’s relative biogas success. Based on this analysis, the authors make recommendations for policy measures that would increase biogas production in the United States. These recommendations include R&D to promote technological advancement with digesters, state and national environmental objectives, state and national renewable energy quotas, financial support for biogas operations, state biogas education and support programs, and infrastructure improvements that facilitate biogas use. Such policy incentives would promote both biogas production and use, and thereby help increase the market penetration of a domestically-produced, renewable, low-carbon fuel.
Hybrid Solar Cells From Silicon Nanocrystals and Conductive Polymers
Authors: Liu Chin-Yi , Kortshagen Uwe R.
Published: October 2010

Hybrid solar cells based on blends of a conjugated polymer, poly-3(hexylthiophene) (P3HT), and silicon nanocrystals (Si NCs) have been developed and characterized. The properties of composite Si NCs/P3HT films which were spun from 1, 2-dichlorobenzene were studied. Under A.M. 1.5 direct illumination conditions (100mW/cm2), devices made with 50wt% 3–5nm Si NCs showed 1.33% power conversion efficiency (PCE) and had a 30% incident-photon-to-current conversion efficiency at 470 nm.
Investigation of 64%Ni on SiO2-Al2O3 Catalyst as Tar Removal Catalysts for Biomass Gasification
Authors: Sricharoenchaikul Viboon , Thassanaprichayanont Sildara , Atong Duangduen
Published: October 2010

Biomass gasification is a recognized process that may generate synthesis gas (H2+CO) from renewable resources. During gasification, a complex mixture of condensable hydrocarbons or tar compounds form; this can interfere with downstream utilization technologies and also reduce gasification efficiency. Catalytic tar conversion of these compounds to additional product gas is technically and economically interesting approach to reduce or to eliminate tar in product stream. In this paper, 64% Ni on SiO2-Al2O3 catalyst was used as tar removal catalyst. The catalytic performance of this catalyst was evaluated by the conversion of benzene as a model of tar component using a fixed bed reactor. The process variables including reaction temperature 500, 600 and 700°C, Amount of steam added in the cracking and reforming reactions of 1.44 and 2.88 vol.%. The reactor effluent was analyzed by on-line FTIR for CO, CO2, CH4, and other hydrocarbons. Part of the gas product was collected in sample vials for concurrent analysis by GC. The results indicated that the highest conversion of benzene and superior ratio of [CO] to [CO2] may be obtained from at 700°C reaction temperature and 1.44% volume of H2O where 91.2% conversion and ratio of 18.1 may be obtained, respectively. Generally, the distribution of produced gas was greater than the data predicted by equilibrium calculation according to water-gas shift reaction.
Analysis of Solar-Thermal Power Cycles for Distributed Power Generation
Authors: Price Suzanne E. , Mayor J. Rhett
Published: October 2010

In this study, the thermoeconometric feasibility of a 12.5 kW solar thermal power system is discussed. A previous study by these authors examined five potential 12.5kW solar thermal cycles and preliminary thermoeconometric analyses based on the collector area. The current study expands to six potential power cycles, including the five from the previous study, the Rankine, R123 Organic Rankine, toluene Organic Rankine, ethylbenzene organic Rankine, and the Kalina cycle, with the addition of the Maloney-Robertson cycle as well as detailed cost analysis for the components associated with each cycle. A detailed first law thermodynamic analysis for the Maloney-Robertson and Kalina cycles is presented. Likewise, the pinch point analysis is used for the inclusion of the sink and source stream as well as a developed heat exchanger model. The thermoeconometric study includes cost-per-component estimates for all of the components in the cycles; thus, increased component cost is taken into account for the ammonia-water cycles. The findings from this study show that R123 is the only cycle that operates with a source temperature below 225°C within the cycle applied operating constraints for meso-scale distributed power generation.. When higher temperatures are achieved, the Kalina cycle has the highest thermal efficiency but also the highest cost-to-efficiency ratio. Therefore, the thermoeconometrics study shows that the toluene and ethylbenzene ORCs have the lowest cost-to-efficiency ratio when source temperatures reach 225°C to 350°C even though they do not have the highest cycle efficiencies.
O2 Releasing Reactivity of Ceramics for Rotary-Type Solar Reactor With Two-Step H2O Splitting
Authors: Tamaura Yutaka , Kaneko Hiroshi
Published: October 2010

The relationship among the factors determining the thermal efficiency to convert concentrated solar thermal energy to chemical energy by the O2-releasing reaction of the reactive ceramics in the tow-step water splitting process has been studied for the development of rotary-type solar reactors. The α O2-releasing reaction which has been discovered in the present study for Ni-ferrite (NiFe2O4) has a high chemical reaction rate (k = 0.50 mol sec−1/m2). From calculation with the heat transfer equation in terms of heat transfer through the cavity wall with thckness, d (m), and heat absorption by the endothermic process of the O2-releasing reaction with rate constant, k (mol sec−1/m2), it is cralified that the heat flux of 2000 kW/m2 can be absorbed by the α O2-releasing reaction using the cavity wall with the thickness, d = 0.00036 m and thermal conductivity, λ = 70 WK−1m−1. The heat loss in the temperature swing (ΔT = 300K) for the two step water splitting of O2 releasing step (TH = 1773K) and H2 generation step (TL = 1473K) is only 8.3% for the α O2-releasing reaction. However, the O2 releasing reaction of NiFe2O4 in the β region where the reaction rate constant is around 0.0001 mol sec−1/m2, the heat flux of the concentrated solar energy to be used for conversion to chemical energy becomes very low around 300 kW/m2; the heat loss by the temperature swing in the two step water splitting is 87%. It is concluded that the α O2-releasing reaction can be used for the rotary-type solar reactor to convert the concentrated solar thermal energy to chemical energy with a high efficiency.
Microstructure and property modifications of an AISI H13 (4Cr5MoSiV) steel induced by pulsed electron beam treatment
Authors: Zhang Kemin , Zou Jianxin , Grosdidier Thierry , Dong Chuang
Published: October 2010

In the present work, surface modifications generated by the low energy high current pulsed electron beam (LEHCPEB) treatments have been investigated on an AISI H13 (4Cr5MoSiV) steel. From the observations of scanning electron microscopy, x-ray diffraction, and electron back scattering diffraction determinations, it could be established that the final structure in the melted layer is a mixture of ultrafine δ phase, martensite, and residual austenite. The formation of the heterogeneous microstructures on the surface layer is related to the very rapid heating, melting, solidification, and cooling induced by the LEHCPEB irradiation. After the LEHCPEB treatment, the wear resistance of the steel effectively improved. This can be mainly attributed to the higher hardness of the ultrafine structures formed on the top surface and the hardened subsurface layers after the treatment.
Detection and Confirmation of
Clostridium botulinum
in Water Used for Cooling at a Plant Producing Low-Acid Canned Foods
Authors: Sachdeva Amita , Defibaugh-Chávez Stephanie L. H. , Day James B. , Zink Donald , Sharma Shashi K.
Published: October 2010

Our laboratory tested water samples used for cooling low-acid canned foods at a canning facility under investigation by the U.S. Food and Drug Administration. We used an enzyme-linked immunosorbent assay with digoxigenin-labeled antibodies (DIG-ELISA) and real-time PCR as screening methods and confirmed the presence of neurotoxin-producing
Clostridium botulinum
in the samples by mouse bioassay.
Oxalate Efflux Transporter from the Brown Rot Fungus
Fomitopsis palustris
Authors: Watanabe Tomoki , Shitan Nobukazu , Suzuki Shiro , Umezawa Toshiaki , Shimada Mikio , Yazaki Kazufumi , Hattori Takefumi
Published: October 2010

An oxalate-fermenting brown rot fungus,
Fomitopsis palustris
, secretes large amounts of oxalic acid during wood decay. Secretion of oxalic acid is indispensable for the degradation of wood cell walls, but almost nothing is known about the transport mechanism by which oxalic acid is secreted from
F. palustris
hyphal cells. We characterized the mechanism for oxalate transport using membrane vesicles of
F. palustris
. Oxalate transport in
F. palustris
was ATP dependent and was strongly inhibited by several inhibitors, such as valinomycin and NH
4
+
, suggesting the presence of a secondary oxalate transporter in this fungus. We then isolated a cDNA,
FpOAR
(

F

omitopsis

p

alustris
o
xalic
a
cid
r
esistance), from
F. palustris
by functional screening of yeast transformants with cDNAs grown on oxalic acid-containing plates. FpOAR is predicted to be a membrane protein that possesses six transmembrane domains but shows no similarity with known oxalate transporters. The yeast transformant possessing
FpOAR
(
FpOAR
-transformant) acquired resistance to oxalic acid and contained less oxalate than the control transformant. Biochemical analyses using membrane vesicles of the
FpOAR
-transformant showed that the oxalate transport property of FpOAR was consistent with that observed in membrane vesicles of
F. palustris
. The quantity of
FpOAR
transcripts was correlated with increasing oxalic acid accumulation in the culture medium and was induced when exogenous oxalate was added to the medium. These results strongly suggest that FpOAR plays an important role in wood decay by acting as a secondary transporter responsible for secretion of oxalate by
F. palustris
.
Wide Distribution among Halophilic Archaea of a Novel Polyhydroxyalkanoate Synthase Subtype with Homology to Bacterial Type III Synthases
Authors: Han Jing , Hou Jing , Liu Hailong , Cai Shuangfeng , Feng Bo , Zhou Jian , Xiang Hua
Published: October 2010

Polyhydroxyalkanoates (PHAs) are accumulated as intracellular carbon and energy storage polymers by various bacteria and a few haloarchaea. In this study, 28 strains belonging to 15 genera in the familyHalobacteriaceaewere investigated with respect to their ability to synthesize PHAs and the types of their PHA synthases. Fermentation results showed that 18 strains from 12 genera could synthesize polyhydroxybutyrate (PHB) or poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). For most of these haloarchaea, selected regions of thephaEandphaCgenes encoding PHA synthases (type III) were cloned via PCR with consensus-degenerate hybrid oligonucleotide primers (CODEHOPs) and were sequenced. The PHA synthases were also examined by Western blotting using haloarchaealHaloarcula marismortuiPhaC (PhaCHm) antisera. Phylogenetic analysis showed that the type III PHA synthases from species of theHalobacteriaceaeand theBacteriadomain clustered separately. Comparison of their amino acid sequences revealed that haloarchaeal PHA synthases differed greatly in both molecular weight and certain conserved motifs. The longer C terminus of haloarchaeal PhaC was found to be indispensable for its enzymatic activity, and two additional amino acid residues (C143 and C190) of PhaCHmwere proved to be important for itsin vivofunction. Thus, we conclude that a novel subtype (IIIA) of type III PHA synthase with unique features that distinguish it from the bacterial subtype (IIIB) is widely distributed in haloarchaea and appears to be involved in PHA biosynthesis.
Mixed-Culture Transcriptome Analysis Reveals the Molecular Basis of Mixed-Culture Growth in
Streptococcus thermophilus
and
Lactobacillus bulgaricus
Authors: Sieuwerts Sander , Molenaar Douwe , van Hijum Sacha A. F. T. , Beerthuyzen Marke , Stevens Marc J. A. , Janssen Patrick W. M. , Ingham Colin J. , de Bok Frank A. M. , de Vos Willem M. , van Hylckama Vlieg Johan E. T.
Published: October 2010

Many food fermentations are performed using mixed cultures of lactic acid bacteria. Interactions between strains are of key importance for the performance of these fermentations. Yogurt fermentation by
Streptococcus thermophilus
and
Lactobacillus bulgaricus
(basonym,
Lactobacillus delbrueckii
subsp.
bulgaricus
) is one of the best-described mixed-culture fermentations. These species are believed to stimulate each other's growth by the exchange of metabolites such as folic acid and carbon dioxide. Recently, postgenomic studies revealed that an upregulation of biosynthesis pathways for nucleotides and sulfur-containing amino acids is part of the global physiological response to mixed-culture growth in
S. thermophilus
, but an in-depth molecular analysis of mixed-culture growth of both strains remains to be established. We report here the application of mixed-culture transcriptome profiling and a systematic analysis of the effect of interaction-related compounds on growth, which allowed us to unravel the molecular responses associated with batch mixed-culture growth in milk of
S. thermophilus
CNRZ1066 and
L. bulgaricus
ATCC BAA-365. The results indicate that interactions between these bacteria are primarily related to purine, amino acid, and long-chain fatty acid metabolism. The results support a model in which formic acid, folic acid, and fatty acids are provided by
S. thermophilus
. Proteolysis by
L. bulgaricus
supplies both strains with amino acids but is insufficient to meet the biosynthetic demands for sulfur and branched-chain amino acids, as becomes clear from the upregulation of genes associated with these amino acids in mixed culture. Moreover, genes involved in iron uptake in
S. thermophilus
are affected by mixed-culture growth, and genes coding for exopolysaccharide production were upregulated in both organisms in mixed culture compared to monocultures. The confirmation of previously identified responses in
S. thermophilus
using a different strain combination demonstrates their generic value. In addition, the postgenomic analysis of the responses of
L. bulgaricus
to mixed-culture growth allows a deeper understanding of the ecology and interactions of this important industrial food fermentation process.
Interference of
Mycoplasma
Infection in a Gene Expression Study: It Was the Environment and Not the Gene
Authors: Hoermann Gregor , Spergser Joachim , Einwallner Elisa , Makristathis Athanasios , Perne Andrea , Willinger Birgit , Schwarzinger Ilse
Published: October 2010

We show that short-term exposure to doxycycline, as used in tetracycline-inducible gene expression models, protects cells from stress-induced death in cultures infected with
Mycoplasma arginini
. Coinciding with the expected maximum level of gene activity, antimicrobial effects of tetracyclines might be mistaken for antiapoptotic properties of the expressed gene product.
Evidence for Different Contributions of Archaea and Bacteria to the Ammonia-Oxidizing Potential of Diverse Oregon Soils
Authors: Taylor Anne E. , Zeglin Lydia H. , Dooley Sandra , Myrold David D. , Bottomley Peter J.
Published: October 2010

A method was developed to determine the contributions of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) to the nitrification potentials (NPs) of soils taken from forest, pasture, cropped, and fallowed (19 years) lands. Soil slurries were exposed to acetylene to irreversibly inactivate ammonia monooxygenase, and upon the removal of acetylene, the recovery of nitrification potential (RNP) was monitored in the presence and absence of bacterial or eukaryotic protein synthesis inhibitors. For unknown reasons, and despite measureable NPs, RNP did not occur consistently in forest soil samples; however, pasture, cropped, and fallowed soil RNPs commenced after lags that ranged from 12 to 30 h after acetylene removal. Cropped soil RNP was completely prevented by the bacterial protein synthesis inhibitor kanamycin (800 μg/ml), whereas a combination of kanamycin plus gentamicin (800 μg/ml each) only partially prevented the RNP (60%) of fallowed soils. Pasture soil RNP was completely insensitive to either kanamycin, gentamicin, or a combination of the two. Unlike cropped soil, pasture and fallowed soil RNPs occurred at both 30°C and 40°C and without supplemental NH
4
+
(≤10 μM NH
4
+
in solution), and pasture soil RNP demonstrated ∼50% insensitivity to 100 μM allyl thiourea (ATU). In addition, fallowed and pasture soil RNPs were insensitive to the fungal inhibitors nystatin and azoxystrobin. This combination of properties suggests that neither fungi nor AOB contributed to pasture soil RNP and that AOA were responsible for the RNP of the pasture soils. Both AOA and AOB may contribute to RNP in fallowed soil, while RNP in cropped soils was dominated by AOB.