In-situ scanning probe microscopy of electrodeposited nickel.

The performance characteristics and material properties such as stress, microstructure, and composition of nickel coatings and electroformed components can be controlled over a wide range by the addition of small amounts of surface-active compounds to the electroplating bath. Saccharin is one compound that is widely utilized for its ability to reduce tensile stress and refine grain size in electrodeposited nickel. While the effects of saccharin on nickel electrodeposition have been studied by many authors in the past, there is still uncertainty over saccharin's mechanisms of incorporation, stress reduction, and grain refinement. In-situ scanning probe microscopy (SPM) is a tool that can be used to directly image the nucleation and growth of thin nickel films at nanometer length scales to help elucidate saccharin's role in the development and evolution of grain structure. In this study, in-situ atomic force microscopy (AFM) and scanning tunneling microscopy (STM) techniques are used to investigate the effects of saccharin on the morphological evolution of thin nickel films. By observing mono-atomic height nickel island growth with and without saccharin present we conclude that saccharin has little effect on the nickel surface mobility during deposition at low overpotentials where the growth occurs in a layer-by-layer mode. Saccharin was imaged on Au(l11) terraces as condensed patches without resolved packing structure. AFM measurements of the roughness evolution of nickel films up to 1200 nm thick on polycrystalline gold indicate that saccharin initially increases the roughness and surface skewness of the deposit that at greater thickness becomes smoother than films deposited without saccharin. Faceting of the deposit morphology decreases as saccharin concentration increases even for the thinnest films that have 3-D growth

Development of efficient, integrated cellulosic biorefineries : LDRD final report.

Cellulosic ethanol, generated from lignocellulosic biomass sources such as grasses and trees, is a promising alternative to conventional starch- and sugar-based ethanol production in terms of potential production quantities, CO{sub 2} impact, and economic competitiveness. In addition, cellulosic ethanol can be generated (at least in principle) without competing with food production. However, approximately 1/3 of the lignocellulosic biomass material (including all of the lignin) cannot be converted to ethanol through biochemical means and must be extracted at some point in the biochemical process. In this project we gathered basic information on the prospects for utilizing this lignin residue material in thermochemical conversion processes to improve the overall energy efficiency or liquid fuel production capacity of cellulosic biorefineries. Two existing pretreatment approaches, soaking in aqueous ammonia (SAA) and the Arkenol (strong sulfuric acid) process, were implemented at Sandia and used to generated suitable quantities of residue material from corn stover and eucalyptus feedstocks for subsequent thermochemical research. A third, novel technique, using ionic liquids (IL) was investigated by Sandia researchers at the Joint Bioenergy Institute (JBEI), but was not successful in isolating sufficient lignin residue. Additional residue material for thermochemical research was supplied from the dilute-acid simultaneous saccharification/fermentation (SSF) pilot-scale process at the National Renewable Energy Laboratory (NREL). The high-temperature volatiles yields of the different residues were measured, as were the char combustion reactivities. The residue chars showed slightly lower reactivity than raw biomass char, except for the SSF residue, which had substantially lower reactivity. Exergy analysis was applied to the NREL standard process design model for thermochemical ethanol production and from a prototypical dedicated biochemical process, with process data supplied by a recent report from the National Research Council (NRC). The thermochemical system analysis revealed that most of the system inefficiency is associated with the gasification process and subsequent tar reforming step. For the biochemical process, the steam generation from residue combustion, providing the requisite heating for the conventional pretreatment and alcohol distillation processes, was shown to dominate the exergy loss. An overall energy balance with different potential distillation energy requirements shows that as much as 30% of the biomass energy content may be available in the future as a feedstock for thermochemical production of liquid fuels

Collaborative fisheries research reveals reserve size and age determine efficacy across a network of marine protected areas

A variety of criteria may influence the efficacy of networks of marine protected areas (MPA) designed to enhance biodiversity conservation and provide fisheries benefits. Meta-analyses have evaluated the influence of MPA attributes on abundance, biomass, and size structure of harvested species, reporting that MPA size, age, depth, and connectivity influence the strength of MPA responses. However, few empirical MPA evaluation studies have used consistent sampling methodology across multiple MPAs and years. Our collaborative fisheries research program systematically sampled 12 no-take or highly protective limited-take MPAs and paired fished reference areas across a network spanning 1100 km of coastline to evaluate the factors driving MPA efficacy across a large geographic region. We found that increased size and age consistently contributed to increased fish catch, biomass, and positive species responses inside MPAs, while accounting for factors such as latitude, primary productivity, and distance to the nearest MPA. Our study provides a model framework to collaboratively engage diverse stakeholders in fisheries research and provide high-quality data to assess the success of conservation strategies

SPECTROSCOPY OF SUBSTITUTED CYCLOHEXOXY RADICALS AND KINETICS OF THEIR REACTIONS WITH O2O_{2}

Author Institution: Chemistry Department, SUNY-Environmental Science and Forestry; Chemistry Department, The Ohio State University; Chemistry Department, Le Moyne CollegeThe laser induced fluorescence spectrum of the $\tilde{B}$ state of 4-methyl cyclohexoxy radical was obtained at 228 K and 50 Torr $N_{2}$. The spectrum appears to arise only from the trans isomer, and is very similar to that observed from cyclohexoxy radical, itself. Thermodynamic arguments indicate the spectrum must arise almost solely from the di-equatorial chair conformer. No significant fluorescence was observed from 4-tert-butyl cyclohexoxy radical. Rate constants were obtained for the reaction of trans-4-methyl cyclohexoxy radical and d11-cyclohexoxy radical with $O^{2}$. Rate constants were measured between 228 and 301 K, and are independent of pressure (50-125 Torr). The temperature dependence of the rate constant for trans-4-methyl cyclohexoxy radical is not as great as that previously measured for cyclohexoxy radical, but is greater than that found previously for acyclic alkoxy radicals

Development of efficient, integrated cellulosic biorefineries : LDRD final report.

Cellulosic ethanol, generated from lignocellulosic biomass sources such as grasses and trees, is a promising alternative to conventional starch- and sugar-based ethanol production in terms of potential production quantities, CO{sub 2} impact, and economic competitiveness. In addition, cellulosic ethanol can be generated (at least in principle) without competing with food production. However, approximately 1/3 of the lignocellulosic biomass material (including all of the lignin) cannot be converted to ethanol through biochemical means and must be extracted at some point in the biochemical process. In this project we gathered basic information on the prospects for utilizing this lignin residue material in thermochemical conversion processes to improve the overall energy efficiency or liquid fuel production capacity of cellulosic biorefineries. Two existing pretreatment approaches, soaking in aqueous ammonia (SAA) and the Arkenol (strong sulfuric acid) process, were implemented at Sandia and used to generated suitable quantities of residue material from corn stover and eucalyptus feedstocks for subsequent thermochemical research. A third, novel technique, using ionic liquids (IL) was investigated by Sandia researchers at the Joint Bioenergy Institute (JBEI), but was not successful in isolating sufficient lignin residue. Additional residue material for thermochemical research was supplied from the dilute-acid simultaneous saccharification/fermentation (SSF) pilot-scale process at the National Renewable Energy Laboratory (NREL). The high-temperature volatiles yields of the different residues were measured, as were the char combustion reactivities. The residue chars showed slightly lower reactivity than raw biomass char, except for the SSF residue, which had substantially lower reactivity. Exergy analysis was applied to the NREL standard process design model for thermochemical ethanol production and from a prototypical dedicated biochemical process, with process data supplied by a recent report from the National Research Council (NRC). The thermochemical system analysis revealed that most of the system inefficiency is associated with the gasification process and subsequent tar reforming step. For the biochemical process, the steam generation from residue combustion, providing the requisite heating for the conventional pretreatment and alcohol distillation processes, was shown to dominate the exergy loss. An overall energy balance with different potential distillation energy requirements shows that as much as 30% of the biomass energy content may be available in the future as a feedstock for thermochemical production of liquid fuels

A facile method for the recovery of ionic liquid and lignin from biomass pretreatment

In the biochemical conversion of lignocellulosic biomass to biofuels, the process of pretreatment is currently one of the most difficult and expensive operations. The use of ionic liquids (ILs) in biomass pretreatment has received considerable attention recently because of their effectiveness at decreasing biomass recalcitrance to subsequent enzymatic hydrolysis. In addition, ILs have the potential for decreasing the need for corrosive or toxic chemicals and associated waste streams that can be generated by other pretreatment methods that utilize acids and/or bases. In this article, we address two significant challenges to the realization of a practical IL pretreatment process. First, we describe a mixture containing specific proportions of a ketone and an alcohol that precipitates cellulose and lignocellulosic biomass from solutions of the IL 1-ethyl-3-methylimidazolium acetate without the formation of intermediate gel phases. Second, an IL recovery process is described that removes lignin and most residual IL solutes and that minimizes energy and solvent use. These two techniques are demonstrated by the pretreatment of 100 g of corn stover with the recovery of 89% of the initial IL and separate corn stover fractions rich in glucans, xylans, lignin, and non-polar substances. These results highlight one potential approach towards the realization of a scalable ionic liquid pretreatment process technology that enables ionic liquid recovery and reuse