Wet Chemical Method for Determining Levels of Ammonia in Syngas from a Biomass Gasifier

A wet chemical sampling method using acidic absorbing solutions was used to determine levels of ammonia (NH3) in syngas from a biomass gasifier. Before syngas is bubbled into the absorbing solutions, a quartz thimble filter is used to filter ash from the gas stream at 450 °C followed by heavy tar removal at about 100 °C. When gasifying corn, good precision was observed for multiple samples collected on any given day of testing. Tests on producer gas obtained from gasification of switchgrass revealed important conditions for successfully sampling NH3. During gasification of switchgrass, high solids loading in the syngas caused the primary cyclone at the gasifier exit to plug, resulting in abnormally high ash loading in the thimble filter in the sampling system. While gasifying the switchgrass, the NH3 levels showed a continuous decline throughout the day. It is suspected that NH3 reacts with the ash in the thimble filter, confounding attempts to accurately measure NH3 in the syngas

Effect of Sample Aging on the Accuracy of the International Energy Agency\u27s Tar Measurement Protocol

The Working Group of the Biomass Gasification Task of the International Energy Agency (IEA) Bioenergy Agreement has developed a protocol for sampling and analysis of tar and particulates from biomass gasifiers, which is commonly accepted as a standard for reliable measurement of tar in producer gas. The methodology is dependent upon dissolving tar in a solvent for subsequent recovery by evaporation or distillation. This paper investigates whether storage of the tar/solvent sample prior to analysis affects the accuracy of the tar measurement. On the basis of the results of this study, we recommend that samples be analyzed within a few hours of collection and never be stored longer than 24 h

Historical Analysis of Timber Dependency in Alabama

Almost every part of Alabama is heavily forested and by most standards the forest products industry is the state\u27s leading industry. A significant portion of the total employment and the majority of the manufacturing employment of these counties are in forest product enterprises, criteria used here to define timber dependent counties. This paper will use the historical demographic, economic, and agricultural census data to trace the development of timber dependency in rural counties in Alabama. Understanding the social and land use history is critical in examining timber dependency in Alabama today. Conclusions will be drawn between rural and timber dependent and non-timber dependent counties

Regional Comparisons of Timber Dependency: The Northwest and the Southeast

We perform a comparison of the timber dependency and socioeconomic characteristics of timber dependent counties for three states in the Northwest region (Idaho, Oregon, and Washington) and three states in the Southeast region (Alabama, Georgia, and Mississippi) of the United States. The purpose of this research is to examine whether two forested areas of the United States experience timber dependency in similar ways. This research defines timber dependent counties as those with 20 percent or more of the total employment in forest-based industries. Questions related to forest-based employment patterns and socioeconomic correlates of timber dependency are examined. Tests of difference between means are used to determine whether timber dependent counties in the two regions score similarly on measures of community well-being. The results show that there is much variation in the characteristics associated with timber dependency in the timber dependent counties in the Southeast and the Northwest. While timber dependency may be applied to both regions, the phenomena can be quite different

Comparison of a Solvent-Free Tar Quantification Method to the International Energy Agency’s Tar Measurement Protocol

This paper presents a new method for measuring tar concentration in biomass-derived producer gas streams. This solvent-free method is much simpler than the evaporative method of the International Energy Agency (IEA) tar protocol. In tests on producer gas from a fluidized bed biomass gasifier this so-called dry condenser method yielded tar measurements with precision better than 5% and accuracy averaging to within 10% of the IEA tar protocol. Comparisons of water vapor concentrations in producer gas as determined by the two methodologies showed poor agreement, which appears to be due to the low precision of both techniques for this measurement, possibly the result of dissolved hydrocarbons in the recovered aqueous phases

Clinical evidence for overcoming capecitabine resistance in a woman with breast cancer terminating in radiologically occult micronodular pseudo-cirrhosis with portal hypertension: a case report

<p>Abstract</p> <p>Introduction</p> <p>We report a case of stage IV breast cancer terminating in an unusual picture of radiologically occult micronodular pseudo-cirrhosis. Contrast-enhanced computed tomography showed no evidence of metastatic breast cancer within the liver. Unlike the few previously reported cases of intrasinusoidal spread of breast cancer, our patient was palliated with a transjugular intrahepatic portosystemic shunt along with salvage chemohormonal therapy. In addition, our patient demonstrated proof of the principle of the dependence of capecitabine (Xeloda) efficacy on dose scheduling as predicted by laboratory studies based on Gompertzian tumor growth and the Norton-Simon hypothesis.</p> <p>Case presentation</p> <p>We report the case of a 52-year-old Caucasian woman who developed radiological signs of portal hypertension without radiological evidence of hepatic metastasis five years after being diagnosed with metastatic breast cancer. She was receiving chemotherapy for stage IV breast cancer initially thought to be metastatic only to the bones. During salvage therapy with high-dose estradiol (Estradiol valerate), vinorelbine (Navelbine) and bevacizumab (Avastin), she suddenly developed signs of portal hypertension confirmed on computed tomography and by portal and systemic venous pressure measurements. Drug toxicity due to bevacizumab (Avastin) was initially and incorrectly entertained as a cause. The patient underwent palliative transjugular intrahepatic portosystemic shunt and transhepatic venous liver biopsy, which revealed the presence of rapidly progressive and uncontrolled metastatic breast cancer. The new discovery of radiologically occult intrasinusodal hepatic metastases with secondary micronodular cirrhosis was found to be the cause of her sudden onset portal hypertension. The patient's resistance to capecitabine (Xeloda) was reversed by changing the schedule of medication to biweekly 7/7 (7 days ingesting drug alternating with 7 days off drug) from the 14/7 (14 days ingesting drug alternating with a 7 day rest period) day schedule approved by the US Food and Drug Administration.</p> <p>Conclusion</p> <p>This case report demonstrates an unusual presentation of radiographically occult hepatic metastasis from breast cancer palliated with transjugular intrahepatic portosystemic shunt. All patients with advanced breast cancer developing unexpected portal hypertension should be considered candidates for liver biopsy despite normal computed tomography of the liver imaging results. This is the first report of a reversal of clinical resistance to capecitabine (Xeloda) by changing from the schedule of 14/7 day to a biweekly 7/7 day schedule. This suggests that a biweekly schedule may be best for some patients.</p

Processes for isolating chitin and chitosan from fungal biomass

Methods of extracting chitin and chitosan from fungal biomass using a solution of one or more ammonia compounds, amines, and/or alkaline silicate compounds. The solution dissolves and extracts amino acids, fatty acids and other carbohydrates from the fungal cells leaving chitin and/or chitosan, and the extractant may be recovered from the liquid by simple phase changes such as heating or cooling, dissociation into volatile components, distillation and/or solidification and separation of immiscible extractants. Further lipid removal may be achieved with one or more organic solvents, which may also be recovered by distillation

Observations on Shorefast Ice Dynamics in Arctic Alaska and the Responses of the Iñupiat Hunting Community

Although shorefast sea ice forms a platform that facilitates travel, camping, and hunting by Iñupiat subsistence hunters and fishers in the western Arctic, the nearshore sea-ice zone remains an unforgiving and dynamic environment. Traditional hunters constantly hone site-specific experiences and skills with which to optimize the reward-to-risk ratio inherent in operating from this coastal ice. Nearshore ice conditions nevertheless can change suddenly, endangering even the most experienced subsistence hunters. This study examines two (of several) 20th-century events, 40 years apart, in which shorefast ice failed, threatening Iñupiat whale hunters with loss of confidence, livelihood, and life. These events differed in character. In one event, the shorefast ice was "crushed" by moving ice floes. In the other, the shorefast ice broke free of land. Our examination focuses on the relationship of subsistence hunters to the ice, the environmental causes of ice failures, the evolving technology for predicting ice behavior, and the longer-term implications of global change for this system. The complexity of geophysical processes underlying coastal ice behavior makes ice failures unpredictable. Thus, hunters must assume and manage risk. The variable and uncertain environment to which whale hunters are accustomed has produced an inherent flexibility that has helped them adapt to new conditions and will continue to do so in the future.Bien que la banquise côtière constitue une plate-forme qui permet aux Iñupiat de l'Arctique de l'Ouest de se déplacer et de camper lorsqu'ils pratiquent la chasse et la pêche de subsistance, la zone de banquise proche du littoral reste un milieu dynamique qui ne pardonne pas. Les chasseurs traditionnels améliorent constamment les habiletés et l'expérience reliées à des sites particuliers, qui leur permettent d'optimiser le rapport récompense-risque inhérent au fait de travailler depuis la glace côtière. Les conditions de cette dernière peuvent toutefois changer brusquement, mettant en danger même les chasseurs de subsistance les plus chevronnés. Cette étude se penche sur deux (parmi plusieurs) épisodes survenus au XXe siècle, à 40 ans d'écart, durant lesquels la banquise côtière s'est rompue, ébranlant la confiance des baleiniers Iñupiat et menaçant leur moyen de subsistance ainsi que leur vie. Ces événements étaient de nature différente. Dans l'un, la glace côtière avait été «écrasée» par des floes en dérive. Dans l'autre, la banquise côtière s'était détachée de la terre ferme. Notre étude se concentre sur le rapport entre les chasseurs de subsistance et la glace, les causes environnementales de la fragilisation de la glace, la technologie mise au point actuellement qui permettrait de prédire le comportement de la glace, et les implications à long terme du changement climatique pour ce système. La complexité des processus géophysiques sous-jacents au comportement de la banquise côtière fait que les ruptures de la banquise sont imprévisibles. Les chasseurs doivent donc assumer le risque et le gérer. L'environnement variable et incertain auquel sont accoutumés les chasseurs de baleine leur a donné une souplesse inhérente qui les a aidés à s'adapter à de nouvelles conditions et continuera de le faire dans l'avenir

Pilot-Scale Continuous-Flow Hydrothermal Liquefaction of Filamentous Fungi

This study examined the potential of using the filamentous fungus Rhizopus oligosporus as a feedstock for hydrothermal liquefaction (HTL). The fungal biomass, cultivated in thin stillage from a corn ethanol plant, was processed at pilot-scale using a 1.5-L capacity continuous-flow HTL system. HTL operating conditions of 300–400 °C at 27 MPa for 12–30 min were tested. Biocrude yields ranging from 48.2 to 60.9% were obtained. At low reaction temperatures (300 °C), yields as high as 59.9% could still be achieved. Aside from the least severe reaction condition studied (300 °C, 12 min), neither the yield nor elemental composition of the biocrude was significantly impacted by residence time or temperature, as is typically seen with batch reactors. Similarities in the biochemical and elemental composition between R. oligosporus and microalgae resulted in biocrude yields that were comparable to those previously reported for continuous-flow systems using microalgae. These findings demonstrate the viability of using fungal biomass as a feedstock for the HTL process, and they show that lower temperatures can be used at pilot-scale while still achieving maximal yields

A Bayesian state-space model using age-at-harvest data for estimating the population of black bears (Ursus americanus) in Wisconsin

Population estimation is essential for the conservation and management of fish and wildlife, but accurate estimates are often difficult or expensive to obtain for cryptic species across large geographical scales. Accurate statistical models with manageable financial costs and field efforts are needed for hunted populations and using age-at-harvest data may be the most practical foundation for these models. Several rigorous statistical approaches that use age-at-harvest and other data to accurately estimate populations have recently been developed, but these are often dependent on (a) accurate prior knowledge about demographic parameters of the population, (b) auxiliary data, and (c) initial population size. We developed a two-stage state-space Bayesian model for a black bear (Ursus americanus) population with age-at-harvest data, but little demographic data and no auxiliary data available, to create a statewide population estimate and test the sensitivity of the model to bias in the prior distributions of parameters and initial population size. The posterior abundance estimate from our model was similar to an independent capture-recapture estimate from tetracycline sampling and the population trend was similar to the catch-per-unit-effort for the state. Our model was also robust to bias in the prior distributions for all parameters, including initial population size, except for reporting rate. Our state-space model created a precise estimate of the black bear population in Wisconsin based on age-at-harvest data and potentially improves on previous models by using little demographic data, no auxiliary data, and not being sensitive to initial population size