Chemical looping gasification of solid fuels using bimetallic oxygen carrier particles – Feasibility assessment and process simulations

The chemical looping gasification (CLG) process utilizes an iron-based oxygen carrier to convert carbonaceous fuels into hydrogen and electricity while capturing CO₂. Although the process has the potential to be efficient and environmentally friendly, the activity of the iron-based oxygen carrier is relatively low, especially for solid fuel conversion. In the present study, we propose to incorporate a secondary oxygen carrying metal oxide, i.e. CuO, to the iron-based oxygen carrier. Using the “oxygen-uncoupling” characteristics of CuO, gaseous oxygen is released at a high temperature to promote the conversion of both Fe₂O₃ and coal. Experiments carried out using a Thermal-Gravimetric Analyzer (TGA) indicate that a bimetallic oxygen carrier consisting of a small amount (5% by weight) of CuO is more effective for coal char conversion when compared to oxygen carrier without copper addition. ASPEN Plus^® simulations and mathematical modeling of the process indicate that the incorporation of a small amount of copper leads to increased hydrogen yield and process efficiency.     

Agricultural best management practices for Conesus Lake: The role of extension and soil/water conservation districts

Small sub-watersheds of the Conesus Lake catchment were the site of a project evaluating the ability of agricultural Best Management Practices (BMPs) to maintain soil and nutrients on the landscape and to reduce the impact of agriculture on downstream aquatic systems. Local agricultural agencies, with participation of local farmers, joined with scientists to focus attention on watershed issues, to develop and foster a sense of stewardship among the farming community, and to assist and coordinate collaboration among academic researchers, governing bodies, and the agricultural community. Cornell Cooperative Extension served as a liaison and as a resource and assisted in the development and implementation of voluntary BMPs in selected sub-watersheds of Conesus Lake. We discuss our approach to working with producers, the selection of watersheds for management, and our decision-making process for implementation of BMPs. Decisions to establish traditional structural and nonstructural management practices on sub-watersheds of Conesus Lake were based on field assessments, soil testing, the Phosphorus Index, and the software package Cornell Cropware. For example, the use of soil testing and the Cornell Cropware software allowed the cooperating farms to apply fertilizer only as needed for optimum crop production. Farmers achieved cost savings because previous plans had not given enough credit to soil reserves, manure, and sod crop nutrients. Low-cost voluntary practices based on well-established agricultural management practices have been combined with cost-shared (structural) practices in Conesus Lake watersheds to mitigate the impact of agricultural runoff on water quality and to improve cost efficiency of agricultural operations.     

Taming Charge Transport in Semiconducting Polymers with Branched Alkyl Side Chains

The solid‐state packing and polymer orientation relative to the substrate are key properties to control in order to achieve high charge carrier mobilities in organic field effect transistors (OFET). Intuitively, shorter side chains are expected to yield higher charge carrier mobilities because of a denser solid state packing motif and a higher ratio of charge transport moieties. However our findings suggest that the polymer chain orientation plays a crucial role in high‐performing diketopyrrolopyrrole‐based polymers. By synthesizing a series of DPP‐based polymers with different branched alkyl side chain lengths, it is shown that the polymer orientation depends on the branched alkyl chain lengths and that the highest carrier mobilities are obtained only if the polymer adopts a mixed face‐on/edge‐on orientation, which allows the formation of 3D carrier channels in an otherwise edge‐on‐oriented polymer chain network. Time‐of‐flight measurements performed on the various polymer films support this hypothesis by showing higher out‐of‐plane carrier mobilities for the partially face‐on‐oriented polymers. Additionally, a favorable morphology is mimicked by blending a face‐on polymer into an exclusively edge‐on oriented polymer, resulting in higher charge carrier mobilities and opening up a new avenue for the fabrication of high performing OFET devices.     

Switchless compact dual-band matching networks for class-E power amplifiers

Two compact switchless dual-band load networks for class-E power amplifier (PA) operating at 800 and 1900 MHz are proposed, featuring small area and low loss which will be suitable for non-concurrent dual-band PA module in handset. Theoretical analysis and design equations are provided along with a loss model, including loss in the transistor and in the load network. Loss model is extracted for each structure to find the design parameters for optimized and balanced efficiency in both bands. Both designs are fabricated on Rogers RO4003 substrate with lumped components. Full PA simulations of both bands are carried out with co-simulation using a Triquint TGF2023-2-10 GaN transistor model, lumped components and EM models of load network layouts for both structures. The PA with transformer-based load network achieves a power added efficiency of 68.6 % at low band and 62.6 % at high band at an output power of 37.8 and 36.7 dBm respectively. The overall area consumed by the load network is 13.5 × 9.6 mm². The LC-based PA has a similar PAE of 68.3 and 60 % at low band and high band, respectively. The output power is 38.1 dBm in the low band and 37 dBm in the high-band. The overall area consumed by the load network is 9 × 10 mm²     

Validity and reliability of the Lesbian, Gay, Bisexual Working Alliance Self-Efficacy Scales.

In this paper, the authors report on the development and initial psychometric evaluation of the Lesbian, Gay, and Bisexual Working Alliance Self-Efficacy Scales (LGB-WASES) with data collected from two studies and 534 counseling trainees. Exploratory factor analysis results yielded a 32-item scale with a three-factor model (a) Emotional Bond, (b) Establishing Tasks, and (c) Setting Goals. LGB-WASES scores were internally consistent and remained stable over a 3-week period. Construct validity evidence suggests the LGB-WASES scores were (a) positively related to general perceptions of counseling self-efficacy and multicultural counseling competency, (b) negatively related to attitudes toward lesbians and gay men, and (d) unrelated to social desirability. Recommendations for future research are also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Factors influencing the prescribing of hydrogel contact lenses

Despite the current market popularity of silicone hydrogel contact lenses, conventional hydrogel lenses still represent a significant proportion of the overall contact lens market. Data gathered from annual UK contact lens fitting surveys over the past 13 years indicate that 64% of hydrogel lenses prescribed during this period were of low/medium water content (≤60% water). Whereas, in the past, practitioners would choose the water content of a hydrogel lens to meet specific clinical needs, this choice appears today to be largely governed by product availability.     

The electrochemical recovery of metallic palladium from spent electroless plating solution

Semiconductor bond pads are sometimes coated with palladium for good electrical properties and wire adhesion. The palladium is deposited by immersing the wafers in an electroless plating solution. When the plating solution is depleted and no longer achieves the desired results it is treated as waste. This work investigates the recovery of the remaining palladium in the waste solution by means of electrochemical deposition onto a high surface area cathode. Experiments show that the remaining palladium can be recovered economically and efficiently. This makes the process environmentally friendly and cost effective.     

Identification of temperature and moisture content fields using a combined neural network and clustering method approach

Studies on the dynamics of temperature and moisture content distributions in porous soils have provided important insight on their effect on the building hygrothermal behavior, where the interaction between both building and soil can contribute to reduce building thermal gains or looses. Hygrothermal aspects can be related to many attributes such as energy consumption, occupants' thermal comfort and health, and material deterioration. Recently, a great variety of mathematical models to predict thermal and moisture content profiles in porous media have been presented in the literature. Most of those models are based on analysis of multilayer measurements or on Fourier analysis. The development and validation of such mathematical models facilitate the understanding of heat and moisture flows at different soil depths. In this research, a radial basis function neural network (RBF-NN) approach, combined with Gath–Geva clustering method in order to predict the temperature and moisture content profiles in soils, has been presented. A set of data obtained from the computation of the coupled heat and moisture transfer in porous soils for the Curitiba city (Paraná State, Brazil) weather data file has been used by the RBF-NN modeling method. Simulation results indicate the potentialities of the RBF-NNs to learn, for the one step ahead identification, the behavior of temperature and moisture content profiles in the media at various depths.     

The influence of P2O5 on clinker reactions

Synthetic clinkers, similar to high-silica Portland Cement clinkers, were prepared from raw material containing at times more than 50% oil shale from Har-Tuv area (central Israel) to which phosphate rock and laboratory grade CaCO₃ and SiO₂ were added. Although some clinkers contained more than 3% P₂O₅, their mineralogical composition was satisfactory (50 to 60% C₃S). This result was obtained by taking into account in the SM formula the P₂O₅ concentrations. The resultant relatively high silica concentrations raise the melting point of the raw meal, causing a non-equilibrium state which allows the formation of C₃S and its preservation.