Two Stage Peroxide-Borohydride Bleaching of Cold Soda Pulp

Survey of Literature Introduction Since the development of cold soda pulping in the early 1950\u27s, the search for suitable bleaching methods has been of primary concern. Cold soda pulp is dark brown in color and resists the bleaching action of most chemicals. Marton (1) suggests that this brown discoloration of hardwood cold soda pulp is due to a material in the cells of the wood, primarily in the heartwood. These substances, which have not been identified, are not the same as lignin but probably develop in a similar manner. The chemicals most often used in bleaching hardwood cold soda pulps have been peroxides, hypochlorites, hydrosulfites, and most recently borohydrides. A satisfactory bleaching procedure should meet the following objectives: 1. Development of high brightness 2. Retention of the initial high yield 3. Low cost In order to achieve these objectives Giertz (2) states that the pulping process should be performed in such a manner that colored lignins do not form and that the bleaching agent should destroy only the coloring material and not react with the lignin. These requirements would eliminate all chlorine compounds which form colored lignin complexes as bleaching agents

Application of remote sensing to selected problems within the state of California

Specific case studies undertaken to demonstrate the usefulness of remote sensing technology to resource managers in California are highlighted. Applications discussed include the mapping and quantization of wildland fire fuels in Mendocino and Shasta Counties as well as in the Central Valley; the development of a digital spectral/terrain data set for Colusa County; the Forsythe Planning Experiment to maximize the usefulness of inputs from LANDSAT and geographic information systems to county planning in Mendocino County; the development of a digital data bank for Big Basin State Park in Santa Cruz County; the detection of salinity related cotton canopy reflectance differences in the Central Valley; and the surveying of avocado acreage and that of other fruits and nut crops in Southern California. Special studies include the interpretability of high altitude, large format photography of forested areas for coordinated resource planning using U-2 photographs of the NASA Bucks Lake Forestry test site in the Plumas National Forest in the Sierra Nevada Mountains

Application of remote sensing to selected problems within the state of California

There are no author-identified significant results in this report

Application of remote sensing to selected problems within the state of California

There are no author-identified signficant results in this report

Application of remote sensing to selected problems within the state of California

There are no author-identified significant results in this report

L-band radar sensing of soil moisture

The performance of an L-band, 25 cm wavelength imaging synthetic aperture radar was assessed for soil moisture determination, and the temporal variability of radar returns from a number of agricultural fields was studied. A series of three overflights was accomplished over an agricultural test site in Kern County, California. Soil moisture samples were collected from bare fields at nine sites at depths of 0-2, 2-5, 5-15, and 15-30 cm. These gravimetric measurements were converted to percent of field capacity for correlation to the radar return signal. The initial signal film was optically correlated and scanned to produce image data numbers. These numbers were then converted to relative return power by linear interpolation of the noise power wedge which was introduced in 5 dB steps into the original signal film before and after each data run. Results of correlations between the relative return power and percent of field capacity (FC) demonstrate that the relative return power from this imaging radar system is responsive to the amount of soil moisture in bare fields. The signal returned from dry (15% FC) and wet (130% FC) fields where furrowing is parallel to the radar beam differs by about 10 dB

Nature Connectedness Moderates the Effect of Nature Exposure on Explicit and Implicit Measures of Emotion

Previous research indicates that both short-term and long-term exposure to natural environments is associated with higher levels of emotional well-being. However, less research has examined whether person-related factors may impact the salutogenic effects of nature. In the current study, we examined whether trait-level nature connectedness moderates the effect of exposure to nature on explicit and implicit measures of affect. Participants (n = 89) completed baseline measurements of trait nature connectedness and affective state. Approximately two weeks later, participants viewed a lab-based immersive simulation of either a natural or built environment and then again completed measures of affective state. Findings indicated that trait nature connectedness moderated the effect of nature on affect, with more positive outcomes of nature exposure observed among those high in nature connectedness. These findings suggest that interacting with nature may be especially beneficial for those who already feel a strong sense of connectedness to the natural environment

G3-homogeneous gravitational instantons

We provide an exhaustive classification of self-dual four-dimensional gravitational instantons foliated with three-dimensional homogeneous spaces, i.e. homogeneous self-dual metrics on four-dimensional Euclidean spaces admitting a Bianchi simply transitive isometry group. The classification pattern is based on the algebra homomorphisms relating the Bianchi group and the duality group SO(3). New and general solutions are found for Bianchi III.Comment: 24 pages, few correction

An Accurate Determination of the Exchange Constant in Sr_2CuO_3 from Recent Theoretical Results

Data from susceptibility measurements on Sr_2CuO_3 are compared with recent theoretical predictions for the magnetic susceptibility of the antiferromagnetic spin-1/2 Heisenberg chain. The experimental data fully confirms the theoretical predictions and in turn we establish that Sr_2CuO_3 behaves almost perfectly like a one-dimensional antiferromagnet with an exchange coupling of J = 1700^{+150}_{-100}K.Comment: revised and reformatted paper with new title to appear in Phys. Rev B (Feb.1996). 3 pages (revtex) with 3 embedded figures (macro included). A complete postscript file is available from http://fy.chalmers.se/~eggert/expsusc.ps or by request from [email protected]

Exposure to human and bovine noroviruses in a birth cohort in southern India from 2002 to 2006

Human and bovine norovirus virus-like particles were used to evaluate antibodies in Indian children at ages 6 and 36 months and their mothers. Antibodies to genogroup II viruses were acquired early and were more prevalent than antibodies to genogroup I. Low levels of IgG antibodies against bovine noroviruses indicate possible zoonotic transmission