3,399 research outputs found

    Seasonal soybean crop reflectance

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    Data are presented from field measurements of 1980 including 5 acquisitions of handheld radiometer reflectance measurements, 7 complete sets of parameters for implementing the Suits mode, and other biophysical parameters to characterize the soybean canopy. LANDSAT calculations on the simulated Brazilian soybean reflectance are included along with data collected during the summer and fall on 1981 on soybean single leaf optical parameters for three irrigation treatments. Tests of the Suits vegetative canopy reflectance model for the full hemisphere of observer directions as well as the nadir direction show moderate agreement for the visible channels of the MSS and poor agreement in the near infrared channel. Temporal changes in the spectral characteristics of the single leaves were seen to occur as a function of maturity which demonstrates that the absorptance of a soybean single leaf is more a function of thetransmittancee characteristics than the seasonally consistent single leaf reflectance

    Measurement of H2O and other trace gases in the stratosphere using a high resolution far-infrared spectrometer at 28 km

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    Data analysis results from the 1983 BIC 1 and 2 balloon flights are presented, with emphasis on H2O2, OH, HCL, O3, O2, and H2O. A 2 sigma limit on H2O2 abundance was set, as a function of altitude. This is comparable to or less than the theoretically predicted winter abundances from the 2-D models of Dupont, with a large enough summer maximum to facilitate concentration profile measurements. There is a definite drop in OH concentration from day to night following two model profiles. There was general agreement between HF measurements. The dominant role of the far wings of H2O lines in low altitude spectra was recognized. The strength of these wings exceeds that of many molecular line cores, including O3 and O2, especially near the long wavelength end of the spectra (100 cm (-1)). Newly measured positions for O3 and H2O were obtained

    A plant canopy light absorption model with application to wheat

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    From the light absorption model the absorption of light in the photosynthetically active region of the spectrum was calculated for a Penjamo wheat crop for several situations including: (1) the percent absorption of the incident radiation by a canopy having a four layer structure; (2) the percent absorption of light by the individual layers within a four layer canopy and by the underlying soil; (3) the percent absorption of light by each vegetative canopy layer for variable sun angle; and (4) the cumulative solar energy absorbed by the developing wheat canopy as it progresses from a single layer through its growth stages to a three layer canopy. This calculation was also presented as a function of the leaf area index

    Measurement of H2O and other trace gases in the stratosphere using a high resolution far-infrared spectrometer at 28 KM

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    The highlights of the stratospheric program were reviewed for the past 2.5 years. The major efforts were analysis of the data from the BIC-2 campaign, and the building or new instrumentation to replace that lost at the end of BIC-2. For clarity, the review will be done by topic, rather than chronologically: construction of the initial far-infrared spectrometer, balloon slight program, laboratory measurement, data analysis, and duplicate stabilized platform

    Building Character

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    New Teachers and Old Pay Structures: An Analysis of How Teacher Pay Influences Job Acceptance of First-Year Teachers

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    This study identified whether compensation packages were a factor in first-year teacher’s decisions to accept a teaching position in the states of Colorado and Louisiana. This study involved (a) identifying the components of a school district’s compensation package that were factors in the job acceptance decisions as indicated by respondents and (b) indicating other factors besides compensation that played a major role in job acceptance decisions. The study surveyed a sample of 12 school districts in Colorado and Louisiana during the 2000-2001 academic school year. It included first-year teachers in the 12 approved school districts that had no previous teaching experience in other school districts. There were 229 first-year teachers from Colorado and Louisiana in the sample. Data was gathered through a survey instrument that was specifically designed for this study

    Phytochemistry and chemosystematics of Artemisia arctica in Alaska

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    Thesis (M.S.) University of Alaska Fairbanks, 2001Artemisia L. (Asteraceae - Anthemideae) is a large and taxonomically complex genus occurring widely throughout the northern hemisphere. Chemical investigations in this genus have mainly been stimulated by the economic and/or medicinal importance of many of its members. This chemical knowledge has also provided useful criteria for resolving systematic uncertainties within the genus. Alaskan Artemisia species are little known chemically despite their historic and contemporary medicinal use. Therefore, an investigation of the chemistry of Alaskan Artemisia arctica was initiated with the dual purpose of searching for structurally novel and/or biologically active compounds and contributing additional criteria for systematic studies of this taxon. Collections of A. arctica from four different geographic locations in Alaska were analyzed for chemical characters and biological activity. The roots and leaves afforded one novel acetylenic isocoumarin, in addition to several known acetylenic and non-acetylenic compounds. The biological and systematic significance of these results are discussed

    Kindling the Spark of Black Male Genius through Education

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    This essay examines the nature of inopportunity associated with blackmaleness, synthesizes the narratives of the other contributors to this issue of the journal, and offers recommendations for how education can support Black males' academic, social, and cultural maturation. While African American males face daunting economic and educational challenges, James and Lewis argue that they can navigate through them to obtain academic and career success while still maintaining their identity as Black males

    The Role of Mentors/Advisors in the Doctoral Training of African American Students at Predominately White Universities: Implications for Doctoral Training

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    The purpose of this study is to examine the relationship and the importance of connecting the African American doctoral students and their advisors in the mentor roles. More specifically, this study brings to the forefront the importance as well as the impact of mentors/advisors and their roles in facilitating academic success for African American doctoral students. Many African American doctoral students are typically misunderstood and misdirected in the types of support that they may need to succeed in graduate school (Gallien & Peterson, 2005). Mentors/advisors and the roles that they have are essential to the success of African American doctoral students. The support structures surrounding the mentor/advisor relationship in this research are essential to how it relates to the needs of the African American doctoral student on a predominately White campus. Given the findings, recommendations are provided for future research and for administrators at predominately White Institutions
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