265 research outputs found
An Investigation of the Influence of Shearing Forces on Pulp Strength
This thesis attempts to determine the importance of shearing forces in the strength development of a pulp.
Theoretically, if these shearing forces are able to flex the fibers and thereby reduce their stiffness, it follows that more intimate fiber to fiber contact will result with a related higher bonded area and consequent increased paper strength.
The pulp was subjected to the shearing forces in a Day sigma blade kneader at a high consistency. The treatment time was increased in sequence in an attempt to obtain the maximum strength development these shearing forces could produce.
The work certainly demonstrated that shearing forces can play an important role in strength development of a pulp. This does not mean to imply that they necessarily do in the conventional processes, however, for other possibly dominating factors in stock preparation such as fiber bruising may affect the strength development before the shearing forces have had ample opportunity
Educational Leadership in the Era of Accountability
Recent changes in federal legislation, including the No Child Left Behind Act of 2001 (NCLB), have placed greater emphasis on accountability via mandated reporting of performance measures
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Aerial and surface rivers: Downwind impacts on water availability from land use changes in Amazonia
The abundant evapotranspiration provided by the Amazon forests is an important component of the hydrological cycle, both regionally and globally. Since the last century, deforestation and expanding agricultural activities have been changing the ecosystem and its provision of moisture to the atmosphere. However, it remains uncertain how the ongoing land use change will influence rainfall, runoff, and water availability as findings from previous studies differ. Using moisture tracking experiments based on observational data, we provide a spatially detailed analysis recognizing potential teleconnection between source and sink regions of atmospheric moisture. We apply land use scenarios in upwind moisture sources and quantify the corresponding rainfall and runoff changes in downwind moisture sinks. We find spatially varying responses of water regimes to land use changes, which may explain the diverse results from previous studies. Parts of the Peruvian Amazon and western Bolivia are identified as the sink areas most sensitive to land use change in the Amazon and we highlight the current water stress by Amazonian land use change on these areas in terms of the water availability. Furthermore, we also identify the influential source areas where land use change may considerably reduce a given target sink's water reception (from our example of the Ucayali River basin outlet, rainfall by 5–12ĝ€% and runoff by 19–50ĝ€% according to scenarios). Sensitive sinks and influential sources are therefore suggested as hotspots for achieving sustainable land–water management
Dame Ethel Smyth\u27s Concerto for Violin, Horn, and Orchestra: A Performance Guide for the Hornist.
Dame Ethel Smyth\u27s Concerto for Violin, Horn, and Orchestra (1927) is a welcome addition to the horn concerto repertory. Moreover, Smyth\u27s Double Concerto has the added distinction of being the first significant piece for horn by a female composer. The Double Concerto was first performed May 5, 1927, in the Queens Hall, London by the renowned Aubrey Brain, horn, and Jelly d\u27Aranyi, violin, with Sir Henry Wood conducting. The Concerto consists of three movements, each featuring beautiful thematic material that is expanded and exchanged between the two soloists and within the orchestra. The Finale is a heroic movement that makes use of hunting motives, a style of horn writing popular since at least the time of Georg Philipp Telemann. This monograph will focus on preparation strategies for performing the horn part of Smyth\u27s Concerto. The first chapter will provide biographical and historical information on Ethel Smyth and her Double Concerto. The second chapter will provide an analysis to help assist the performer in understanding the piece. It will include a discussion of topics such as form, harmony, motives, and rhythms. The third chapter will be a practical guide for the horn player. It will provide teaching methods and exercises for developing multiphonic techniques, suggestions for coping with the awkward passages marked con sordino, as well as a variety of alternate fingerings for stopping. A description of Aubrey Brain\u27s instrument and sound will suggest an appropriate timbre for this piece and a discussion of seating arrangements will address issues of balance
A Search for Doradus-Type Variable Stars in the Hyades
Doradus stars are photometrically variable early F-type stars on or
just above the main sequence in the Hertzsprung-Russell Diagram. They vary by
as much as 0.1 mag on time scales an order of magnitude slower than the
fundamental radial pulsation period. These brightness variations are presumably
due to non-radial gravity-mode pulsations. We obtained high precision -band
photometry of 8 F0 to F5 stars in the Hyades (BS 1319, BS 1354, BS 1385, BS
1408, BS 1430, BS 1432, BS 1459, and BS 1472) and found that none of them
showed strong evidence of Dor-type variability. Since
Dor-type candidates are found in the Pleiades and in NGC 2516 (having ages of
78 and 137 Myr, repectively) but apparently not in the Hyades (age 600
Myr), we hypothesize that the Dor phenomenon is a characteristic of
relatively young F stars.
Two of the stars investigated showed marginal evidence of low-amplitude
variability. The 3 mmag variability of the F5 star BS 1319 is most likely
due to rotational modulation of star spots, though it is not impossible that it
is a Dor star. Another F5 star BS 1459 ( mmag) has a
possible period similar to Scuti stars, but no firm conclusions should
be made concerning its behavior unless and until its variability is confirmed.Comment: 8 pages, Latex, uses MN.STY, 6 figures, available via Fax or regular
pos
Aerial and surface rivers: downwind impacts on water availability from land use changes in Amazonia
The abundant evapotranspiration provided by the Amazon forests is an important component of the hydrological cycle, both regionally and globally. Since the last century, deforestation and expanding agricultural activities have been changing the ecosystem and its provision of moisture to the atmosphere. However, it remains uncertain how the ongoing land use change will influence rainfall, runoff, and water availability as findings from previous studies differ. Using moisture tracking experiments based on observational data, we provide a spatially detailed analysis recognizing potential teleconnection between source and sink regions of atmospheric moisture. We apply land use scenarios in upwind moisture sources and quantify the corresponding rainfall and runoff changes in downwind moisture sinks. We find spatially varying responses of water regimes to land use changes, which may explain the diverse results from previous studies. Parts of the Peruvian Amazon and western Bolivia are identified as the sink areas most sensitive to land use change in the Amazon and we highlight the current water stress by Amazonian land use change on these areas in terms of the water availability. Furthermore, we also identify the influential source areas where land use change may considerably reduce a given target sink's water reception (from our example of the Ucayali River basin outlet, rainfall by 5–12ĝ€% and runoff by 19–50ĝ€% according to scenarios). Sensitive sinks and influential sources are therefore suggested as hotspots for achieving sustainable land–water management
Septin-dependent compartmentalization of the endoplasmic reticulum during yeast polarized growth
Polarized cells frequently use diffusion barriers to separate plasma membrane domains. It is unknown whether diffusion barriers also compartmentalize intracellular organelles. We used photobleaching techniques to characterize protein diffusion in the yeast endoplasmic reticulum (ER). Although a soluble protein diffused rapidly throughout the ER lumen, diffusion of ER membrane proteins was restricted at the bud neck. Ultrastructural studies and fluorescence microscopy revealed the presence of a ring of smooth ER at the bud neck. This ER domain and the restriction of diffusion for ER membrane proteins through the bud neck depended on septin function. The membrane-associated protein Bud6 localized to the bud neck in a septin-dependent manner and was required to restrict the diffusion of ER membrane proteins. Our results indicate that Bud6 acts downstream of septins to assemble a fence in the ER membrane at the bud neck. Thus, in polarized yeast cells, diffusion barriers compartmentalize the ER and the plasma membrane along parallel lines
Prostate Cancer Risk Is not Altered by TP53AIP1 Germline Mutations in a German Case-Control Series
Prostate cancer susceptibility has previously been associated with truncating germline variants in the gene TP53AIP1 (tumor protein p53 regulated apoptosis inducing protein 1). For two apparently recurrent mutations (p.Q22fs and p.S32X) a remarkable OR of 5.1 was reported for prostate cancer risk. Since these findings have not been validated so far, we genotyped p.Q22fs and p.S32X in two German series with a total of 1,207 prostate cancer cases and 1,495 controls. The truncating variants were not significantly associated with prostate cancer in none of the two cohorts, nor in the combined analysis [odds ratio (OR) = 1.16; 95% confidence interval (CI 95%) = 0.62–2.15; p = 0.66]. Carriers showed no significant differences in family history of prostate cancer, age at diagnosis, Gleason score or PSA at diagnosis when compared to non-carrier prostate cancer cases. The large sample size of the combined cohort rejects a high-risk effect greater than 2.2 and indicates a limited role of TP53AIP1 in prostate cancer predisposition
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