Literature reports have indicated that application of sonic pressure waves enhances the rate of impregnation of preservatives in wood. However, these studies have been limited and inconclusive. The technique or process is not in commercial use. In this study a laboratory scale treating cylinder connected to a mechanical sonic wave generator was used to measure the rate of impregnation of water in ponderosa pine at pressures of 0.28, 0.55 and 0.69 MPa and Douglas-fir at pressures of 0.55 and 0.69 MPa at a frequency of 30 Hz. Results were compared with those obtained at the same conditions of static hydraulic pressure. Statistical analysis showed that sonic treatments were at least as effective as, but not consistently superior to, hydraulic pressure treatments in the case of ponderosa pine. Statistical analysis of the results from Douglas-fir treatment showed that sonic treatment was superior than hydraulic treatment. / Graduation date: 1995

The purpose of this study was to evaluate the applied use of a commercial UV unit for air sanitation in the cold storage rooms of a local supermarket chain. On-site testing was performed in four supermarkets (two control stores without UV units and two experimental stores) and one warehouse employing UV units. Meat processing, meat storage, and produce storage rooms were randomly sampled by the open plate and swab methods. Commonly occurring "representative microorganisms" were then selected and identified as Pseudomonas sp., Flavobacterium sp., Bacillus sp., Rhodotorula sp., and Penicillium sp. which were taken into the laboratory for UV testing. Representative microorganisms were effectively killed by UV when tested in the laboratory. Exposure to UV was conducted on agar streaked plates and aerosol suspensions of the microorganisms. The effectiveness of the commercial UV unit in the applied setting was less easily determined due to a complexity of changing variables between rooms and between stores. In general, the UV unit appeared to be of noticeable benefit where airborne yeasts and molds were predominant. This occurred in produce rooms. Regular maintenance of the UV unit was necessary for maximum efficiency. The meat processing room presented unique problems relating to procedural habits of the personnel. In all supermarket cold rooms, good "housecleaning" remained the key to controlling microorganisms.Ball State UniversityMuncie, IN 47306

Step-Flash Imprint Lithography (S-FIL[trademark]) is a low-cost, high-resolution, high-throughput pattern replication process with the potential to become the savior for the future of integrated circuit (IC) manufacturing where continued success ultimately depends on improvements in lithographic resolution. Traditional, optical lithography has driven projection imaging to its physical limits, and a new, disruptive lithography technique is needed for continued growth of the semiconductor industry. The revolutionary S-FIL process is based on the fast, in-situ polymerization of a liquid imprint material in contact with a high-resolution mold or template. The templates, fabricated by direct-write lithography, present the greatest expense when implementing an S-FIL process in manufacturing; therefore, the template lifetime must be maximized to distribute costs over a large number of products. Degradable cross-linking materials allow imprint resist contaminated templates to be cleaned without the risk of inorganic residues becoming lodged on the template surface. Cured imprint resist is insoluble in all non-reactive solvents due to its highly cross-linked structure. A polymer contaminate may be rendered soluble by degrading the cross-links and reducing the molecular weight. Several degradable cross-linker candidates were examined for compatibility with S-FIL processing and utility for wafer imprint reworking and template cleaning. The properties of the imprint resists formulated with degradable cross-linkers are reported. Tertiary ester and acetal containing moieties were di-functionalized with acrylate groups to form S-FIL compatible and acid degradable imprint precursors. Both ester and acetal cross-linkers are neat, low-viscosity ([less than or equal to] 20 cP) liquids at room temperature and are miscible with common imprint precursor components. Classical gel theory predicts that greater than 99% de-cross-linking reaction conversion is necessary to achieve solubility in a cured imprint resist formulation with 10 wt% degradable cross-linker. Concentrated sulfuric acid and heat was used to successfully strip tertiary ester cross-linkers from wafer and model template surfaces. Acetal cross-linkers were demonstrated to strip in the presence of trifluoroacetic acid at room temperature. Three-dimensional patterning is an integral benefit of S-FIL, which enables the streamlining of dual damascene processing with the use of multi-level templates. Multi-level imprint patterning allows the removal of over 100 unit process steps from the fabrication of interconnect structures in a modern IC chip. Multi-level S-FIL can be integrated into existing copper damascene interconnect fabrication using two different strategies. One technique requires an imprint resist and etch process for transferring multi-level imprints into an industry standard low-k dielectric. Some of the considerations for designing the multi-level resist and etch process are briefly described. The second strategy leverages the broad variety and flexibility of the imprint materials set, which is not available in photoresist materials technology. New “functional” imprint materials may be used with multi-level S-FIL to produce interconnect structures by directly imprinting an interlayer dielectric (ILD) precursor. The challenges associated with introducing new dielectric materials into a copper damascene process are presented. The design, processing, characterization and integration of novel materials is documented. Multi-level S-FIL with a directly patternable dielectric (DPD) enables low-cost fabrication of interconnect structures in an IC manufacturing back end of line. DPD’s based on either sol-gel or benzocyclobutane and acrylate functionalized polyhedral oligomeric silsesquioxanes show promise for integration as ILD’s based on sufficient thermal and mechanical properties. Electrical test vehicle integration with sol-gel formulated DPD’s shows promising yield of interconnect structures with vias ranging from 2 to 0.12 [mu]m. Examination of interconnect structure revealed an acceptable via profile and sufficient contact with metal one for integration in IC devices. / text

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Oxygen hole-doping effects on a spin-chain system, Ca[subscript 2+chi]Y[2-chi]Cu₅O[subscript 10-delta](CaYCuO) are reported. CaYCuO is a good specimen to study the magnetic properties of the CuO₂ chain at the ground state because it has no complex structure other than the chain and it has hole dopability up to the formal copper valence number of +2.4. Specifically, we can dope holes into the CuO₂ chain by substituting Ca²⁺ for Y³⁺ or by utilizing oxygen deficiency. After a systematic study of the two methods to dope holes, we found that oxygen doping makes a more critical change in magnetic ordering in the chain than the replacement of Ca²⁺. Oxygen deficiency effects of the chain on the magnetic properties were explained using a mean field theory. A new relation for the effective hole doping was found as p = x - [alpha delta], where a = 3/2(x - [delta]) - 1/4. We study the anisotropy of magnetic properties of single crystal Li-cathode material (LiFePO₄) for g-factor, Curie-Weiss temperature, and effective moment. Magnetic properties Au/SiO₂ coated [gamma]-Fe₂O₃ are compared with pure [gamma]-Fe₂O₃ finding a decrease in the blocking temperature and the irreversible temperature for the coated nanoparticles. / text

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Conjugated linoleic acid (CLA) is predominantly found in foods of ruminant origin such as milk and processed cheese, and has gained much interest recently due to its beneficial health and biological effects on animals and humans. / The bioconversion of linoleic acid (LA) and linolenic acid (LNA) by a selected Bifidobacterium from healthy infant feces was studied. Bifidobacterium breve JKL03 had the ability to convert linolenic acid (0.2 mg/ml) to CLNA in fermentation of skim milk medium for 24 h up to a yield of 72.0% (up to 74.7% under aerobic conditions) and linoleic acid (0.2 mg/ml) into CLA by fermentation in skim milk medium for 24 h up to a yield of 23.9% (up to 28.0% under aerobic conditions). / B. breve JKL03 was also co-fermented with Lactobacillus acidophilus (NCFMRTM strain), a commonly added starter culture, to observe the resulting effects on growth during fermentation for yogurt production. Fermentation of LNA in skim milk with B. breve JKL03 and L. acidophilus (NCFM) maintained high CLNA production level. On the other hand, CLA production in the same media with both strains did not exhibit as high level as with the single B. breve. / These results are important for the advancement of knowledge on the production of CLA and CLNA in dairy products and for knowledge on the basic metabolic mechanisms for such conversion.

A unique penetration instrument has been developed to evaluate the role of surfactants in kraft pulping process. This instrument can screen surfactants which can improve the wood impregnation more effectively and much faster than pilot-plant experiment. The role of surfactants in wood penetration has been explored. Surfactants can improve wood impregnation by dispersing the extractives in the wood structure and optimizing the interfacial properties between wood surface and kraft liquor. The addition of two blends of anionic and nonionic surfactants into kraft pulping process results in a significant reduction of the screen rejects and an increase of screened yield at the same delignification rate. / Six wood species were tested in this study including both non-resinous and resinous wood species. Both sapwood and heartwood of these species were tested. Surfactants were found to have no improvement on sapwood, but a significant improvement on heartwood. The critical micelle concentrations (CMC) of surfactants in kraft liquor were determined. The best dosages of surfactants based on CMC were also determined in this study.

No description available.