Ethanol production from wood via concentrated acid hydrolysis,chromatographic separation,and fermentation

BACKGROUND: Production of bioethanol from wood using concentrated acid hydrolysis has received less attention than the dilute acid hydrolysis route. The feasibility of producing lignocellulosic bioethanol from spruce and birch via concentrated acid hydrolysis was studied experimentally. Hydrolysis with sulfuric acid, chromatographic purification of the hydrolysate, and fermentation of the monosaccharides were investigated. RESULTS: Monosaccharide yields of 70% were obtained in the hydrolysis of spruce and birch. Only low amounts of by‐products were formed. With chromatographic purification of the hydrolysate, over 90% of the hydrolysis acid was recovered for recycling, and furfural and HMF were removed completely. Most of the acetic acid was recovered in a separate fraction. The monosaccharide yield in a single pass separation was approximately 70%. In the fermentation, S. cerevisiae produced higher amounts of ethanol and more efficiently than P. stipitis. Chromatographically purified hydrolysates gave higher ethanol productivities and yields than Ca(OH)₂ neutralized hydrolysates. CONCLUSIONS: Chromatographic purification of concentrated acid lignocellulosic hydrolysates has advantages when compared with neutralization with Ca(OH)₂. With chromatography, most of the inhibitory compounds can be removed from the hydrolysates. In addition, due to the recycling of the hydrolysis acid, the economy of the bioethanol manufacturing process is increased considerably. Copyright © 2011 Society of Chemical Industry     

Diversifying meat consumption patterns: consumers' self-reported past behaviour and intentions for change

This study analysed meat consumption patterns among Finnish consumers, considering both stated past changes and intended future changes. Consumer segments with different patterns of and reasons for change were identified. Latent class analysis revealed six consumer clusters that formed three major cluster blocks. The first block, comprising 48% of the consumers, had established consumption patterns and no intentions to change them. In the second block, with 13% of the consumers, consumption patterns had already shifted towards more vegetables and less meat. The third block, with 39% of the consumers, was identified to be in the middle of a change with a general tendency to reduce the use of meat and increase the use of vegetables. Although the environmental effects of meat and animal welfare issues were important reasons for change in some clusters, healthiness was the most salient stated reason for changing consumption habits.     

Poly(ethylene oxide)‐block‐poly[2‐(dimethylamino)ethyl methacrylate] as Strengthening Agent in Paper: Dynamic Mechanical Characterization

To enhance adhesion properties of PEO on wood fibers, block polymers of PEO and 2‐(dimethylamino)ethyl methacrylate were synthesized. The polymers were further modified to obtain strongly cationic species. The resulting polymers were used as additives in paper sheets. Papers were studied by DMA in a controlled‐humidity chamber. Addition of the PEO block co‐polymers enhanced paper strength. The strength of the paper sheets was highest when polymer with molecular weight of 400 kg · mol^?1 was used as an additive. Highly cationic block co‐polymers increased moduli of paper sheets more than their weakly cationic analogs, which indicated strong interaction with fiber surfaces. Strength of the paper sheets decreased both with increased temperature and humidity.

     

Long-term effects of elevated UV-B radiation on photosynthesis and ultrastructure of Eriophorum russeolum and Warnstorfia exannulata

The depletion of stratospheric ozone above the Arctic regions may increase the amount of UV-B radiation to which the northern ecosystems are exposed. In this paper, we examine the hypothesis that supplemental UV-B radiation may affect the growth rate and photosynthesis of boreal peatland plants and could thereby affect the carbon uptake of these ecosystems. In this study, we report the effects of 3-year exposure to elevated UV-B radiation (46% above ambient) on the photosynthetic performance and ultrastructure of a boreal sedge Eriophorum russeolum and a moss Warnstorfia exannulata. The experiment was conducted on a natural fen ecosystem at Sodankylä in northern Finland. The effects of UV-B radiation on the light response of E. russeolum CO₂ assimilation and the maximal photochemical efficiency of photosystem II in a dark-adapted state (F_v/F_m) were measured in the field. In addition, the effect of supplemental UV-B radiation on organelles of photosynthetic cells was studied by electron microscopy. The UV-B treatment had no effect on the CO₂ assimilation rate of either species, nor did it affect the structure of the cell organelles. On chlorophyll fluorescence, the UV-B exposure had only a temporary effect during the third exposure year. Our results suggested that in a natural ecosystem, even long-term exposure to reasonably elevated UV-B radiation levels does not affect the photosynthesis of peatland plants.     

Release of model compounds from modified lactone copolymers

The applicability of three different P(ϵ-caprolactone-co-DL -lactide) copolymers for injection-molded controlled release devices was evaluated. The copolymers of ϵ-caprolactone and DL -lactide were polymerized in bulk using Sn(II) octoate as the catalyst. Glycerol, polyethylene glycol 1000, and polyethylene glycol 4000 were used as initiators. Copolymers were characterized by size exclusion chromatography, differential scanning calorimetry, and nuclear magnetic resonance spectroscopy measurements. The release of two model compounds, theophylline and propranolol hydrochloride, at different loadings (2–30 wt %) was studied. The solubility of the model compounds into the matrices was confirmed to be low by DSC measurements. Increasing the hydrophilicity of the copolymer matrix increased the release rates of both model compounds. The results clearly demonstrate that the desired release rates of these model compounds can be tailored by varying the compound loading or modifying the hydrophilicity of the matrix copolymer. The copolymers were found to be relatively stable during the 4-month hydrolysis. Addition of hydrophilic polyethylene glycol blocks into the backbone of the copolymer chain increased water absorption and thus the degradation was faster. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2118–2126, 2001     

Further improvement of broad specificity hapten recognition with protein engineering

Sulfa-antibiotics (sulfonamides) are widely used in veterinarymedicine. Meat and milk from treated animals can be contaminatedwith sulfa residues. Current sulfonamide assays are unfit forscreening of food, because they are either too laborious, insensitiveor specific for a few sulfa compounds only. An immunoassay fordetection of all sulfas in a single reaction would be usefulfor screening. Previously we have improved the broad specificitysulfa binding of antibody 27G3 with random mutagenesis and phagedisplay. In order to improve the properties of this antibodyfurther, mutants from the previous study were recombined andmore mutations introduced. These new libraries were enrichedwith phage display and several different mutant antibodies wereisolated. The cross-reaction profile of the best mutant wasbetter than that of the wild-type antibody and the mutants ofthe previous study: it was capable of binding 10 of the tested13 sulfonamides within a narrow concentration range and alsobound the rest of the sulfas 5- to 11-fold better than the mutantsof the previous study.     

By-Products in Earth Construction: Environmental Assessments

In Finland, some industrial residuals (by-products) have been used in earth construction since the 1970s. The lack of a general code of practice on environmental assessments of by-product utilization has led to nonuniform approval practices. In most countries, environmental standards are mainly based on health risks related to contaminant leachability. Leaching tests and solubility standards vary. Standards on waste composition and mix proportions have also been adopted in many countries. Based on a survey of practices in various countries, a hierarchical procedure is presented for the environmental assessments relevant to the utilization of by-products. In this model, the verification of environmental suitability can be based on a composition analysis, studies on leaching of contaminants, or a risk assessment procedure. In the next stage, composition and solubility standards (MPE values) need to be issued. Despite some identified drawbacks and data gaps, the Dutch methodology proved to be the most appropriate with respect to the derivation of substance-specific MPEs.     

Beyond the Individual: The Impact of Ethnic Context and Classroom Behavioral Norms on Victims' Adjustment.

With a sample of 1,630 sixth-grade students from 77 classrooms, the authors used hierarchical linear modeling to examine how ethnicity within context and classroom social disorder influenced the association between peer victimization and social-psychological adjustment (loneliness and social anxiety). Victimized students in classrooms where many classmates shared their ethnicity reported feeling the most loneliness and social anxiety. Additionally, classroom-level social disorder served as a moderator such that the association between victimization and anxiety was stronger in classrooms with low social disorder. Both findings were interpreted as evidence that problem behavior deviating from what is perceived as normative in a particular context heightens maladjustment. The authors discuss implications for studying ethnicity and classroom behavioral norms as context variables in peer relations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Release of ibuprofen from poly(ε‐caprolactone‐co‐D,L‐lactide) and simulation of the release

A study was made of the effects of the initial ibuprofen load and of the specimen shape on the release of ibuprofen from poly(ε‐caprolactone‐co‐D,L ‐lactide). The mol ratio of the comonomers in the copolymer was 96/4 (caprolactone to lactide) and the experiments were conducted at 37°C in vitro. The results showed that release of ibuprofen is fast and that the rate and profile of the release vary with both the initial load of ibuprofen and the shape of the specimen. The rate of ibuprofen release increases with the initial load and with the surface area‐to‐volume ratio of the specimen, obeying Fickian diffusion. The experimental findings were compared with the results of a mathematical simulation model based on the finite‐difference method. Diffusion parameters needed for the simulation were determined from a separately conducted set of experiments using various methods. For the most part, the results of the simulations and the experiments were in good agreement. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1279–1288, 2003