130,774 research outputs found
Application of hard coatings to substrates at low temperatures
No full textBIRL, the industrial research laboratory of Northwestern University, has conducted unique and innovative research, under sponsorship from the NASA Marshall Space Flight Center (MSFC), in the application of hard, wear resistant coatings to bearing steels using the high-rate reactive sputtering (HRRS) process that was pioneered by Dr. William Sproul, the principal investigator on this program. Prior to this program, Dr. Sproul had demonstrated that it is possible to apply hard coatings such as titanium nitride (TiN) to alloy steels at low temperatures via the HRRS process without changing the metallurgical properties of the steel. The NASA MSFC program at BIRL had the specific objectives to: apply TiN to 440C stainless steel without changing the metallurgical properties of the steel; prepare rolling contact fatigue (RCF) test samples coated with binary hard coatings of TiN, zirconium nitride (ZrN), hafnium nitride (HfN), chromium nitride (CrN), and molybdenum nitride (MoN), and metal coatings of copper (Cu) and gold (Au); and develop new alloyed hard coatings of titanium aluminum nitride (Ti(0.5)Al(0.5)N), titanium zirconium nitride (Ti(0.5)Zr(0.5)N), and titanium aluminum vanadium nitride
Optimising Design Parameters of a Building-Integrated Photovoltaic Double-Skin Facade in Different Climate Zones in Australia
No full textEnergy used in buildings is mainly attributed to provide the desired thermal comfort, which could result in an increase in carbon emission and, in turn, lead to further environmental degradation. A Building-Integrated Photovoltaic Double-Skin Façade (BIPV-DSF) is a promising way to maintain indoor thermal comfort, obtained with low environmental impact and energy consumption. The appropriate design of BIPV-DSFs can maximise indoor thermal comfort and energy efficiency for buildings. This paper presents optimal BIPV-DSF design solutions, which are dedicated to offering comfortable and energy-efficient buildings, through optimisation of the most important design parameters of a BIPV-DSF under three different climate conditions in Australia. The results illustrate how thermal transmittance (U-value) and solar heat gain coefficient (SHGC) of windows of the BIPV-DSF, as the most important design parameters, were optimised for application in the context of different climates, operation modes, and orientations. The paper contributes to the matters concerning the integrated effect of BIPV-DSFs on thermal comfort and energy performance in buildings
[Letter from R. D. Hill to T. N. Carswell - February 3, 1950]
No full textA letter written to Mr. T. N. Carswell, Abilene, Texas, from R. D. Hill, Little Rock, Arkansas, dated February 3, 1950. Hill requests that Carswell hold the letter for instructions to be utilizied later and suggests he obtain Cashier's Checks. Hill identifies "his man" in Albuquerque as Elmer C. Sproul, describes Sproul's background and gives his approval of Sproul. The reverse side includes a handwritten postscript by Hill informing Carswell that he learned that the tubing which Dalton wrote about is of smaller diameter than the pipe presently used by the firm thus it would not fit the units they are making
Three Unconventional Kinesins Exhibit Novel Microtubule Interactions:The Characterization of Kar3Cik1, Kar3Vik1, and Nod
No full textMy dissertation work was focused to characterize three members of the Kinesin superfamily in vitro. Kinesins are required in the cell for the correct localization and directed transport of proteins, DNA, RNA and cellular organelles. The three molecular motors of the kinesin superfamily studied here are Kar3Cik1, Kar3Vik1 and Nod. These three kinesins are unconventional in that they do not motor to the microtubule plus end transporting cargo over long distances, like Kinesin-1. Kar3Cik1 and Kar3Vik1 are Saccharomyces cerevisiae Kinesin-14s, exhibiting minus end directionality characteristic of Kinesin-14s. Kar3Cik1 is essential for meiosis and for karyogamy, or mating in yeast. Kar3Cik1 also has non-essential roles in mitosis. Kar3Vik1 plays an important role at the spindle pole body during yeast mitosis. My work has shown that the two heterodimers interact with the microtubule in very different ways. Cik1 targets Kar3 to microtubule plus ends and enhances the Kar3-instrinsic depolymerizing ability. In contrast Vik1 binds the microtubule in addition to the Kar3 motor domain and depresses the Kar3 depolymerizing ability. Both of these functions correlate with the in vivo phenotypes and suggest different mechanisms of action for the two heterodimers. Nod is a Drosophila melanogaster orphan kinesin proposed to provide a "polar ejection force" to stabilize chromosomes at the metaphase plate in meiosis. Our work characterized Nod as a kinesin that regulates microtubule dynamics by binding to the microtubule plus end and promoting microtubule polymerization. These results provide a mechanistic explanation for the polar ejection force observed in vivo. My dissertation work has provided knowledge about the many ways in which different kinesins can interface with and regulate microtubule dynamics
Student's perceptions of effective leadership based on both the gender of the student and the gender of the leader
No full textPlan BThe purpose of this study was to determine both the relationship between the gender of the 9th grade students at Altoona High School and the rating of leadership effectiveness of males and females as measured by the Kapanke-Sproul scale. A 4-item questionnaire was administered to 100 of 120 students in the ninth grade at Altoona High School. Analysis of variance was used for the purpose of data analysis.
This study utilized four pictures with narrative descriptions attached. A picture of a male described as an effective leader was given to half the class, while the other half received a picture of a female with the same description. Next, half the class was given a picture of a female described as an effective leader and the other half was given a male with the same description.
Thirdly, the half the class was given a picture of a male with a description of an ineffective leader, while the other half was given a picture of a female with the same description. Last, half the class was given a picture of a female with a description of an ineffective leader, and the other half was given a picture of a male with the same description. Along with each scenario, students were given a "Likert scale" and asked to rate their perception of each leader.
The data analysis cumulatively indicated that there was no statistically significant difference between the perception of leaders based on the gender of the leader or the gender of the student, therefore the Null Hypothesis was accepted. The results seem to be a positive statement about the direction that society has taken in regards to equality between men and women
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
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