Tennessee Rural Middle School Teachers\u27 Perceptions Of Academic Goal Setting For Students

Since the 1960s, business leaders and educators used the idea of goal setting theory as a guide to success. Teachers who implemented goal setting strategies contributed to student success and achievement. During my study, I found little existing literature focused on academic goal setting implementation for students in Tennessee rural middle schools containing grades six through eight. The purpose of this qualitative interpretive study was to investigate Tennessee rural middle school teachers’ perceptions about implementing academic goal setting for students. I sent an online Google Forms questionnaire to 117 certified and licensed teachers in varying Tennessee rural middle schools. After 21 teachers completed the questionnaire, I found participants did not have the same experiences with academic goal setting implementation for students in their middle schools or districts. All 21 participants answered all the questions; however, I only used 20 participant responses for data analysis. I analyzed the data using open, axial, and selective coding to generate themes. The results included varying benefits in implementing student academic goal setting at the middle school level, including increased student motivation and accountability. Professional Learning Communities and various strategies were also perceived as benefits by teachers. On the contrary, additional results yielded perceived barriers to academic goal setting implementation for students, which included a lack of teacher training and experience, time, and student buy in. Rural Middle School teachers needed opportunities to collaborate, hear success stories, and learn strategies behind academic goal setting implementation for students

Measurement of the lunar neutron density profile

An in situ measurement of the lunar neutron density from 20 to 400 g/sq cm depth between the lunar surface was made by the Apollo 17 Lunar Neutron Probe Experiment using particle tracks produced by the B10(n, alpha)Li7 reaction. Both the absolute magnitude and depth profile of the neutron density are in good agreement with past theoretical calculations. The effect of cadmium absorption on the neutron density and in the relative Sm149 to Gd157 capture rates obtained experimentally implies that the true lunar Gd157 capture rate is about one half of that calculated theoretically

Interpretation of Solar System Abundances Around the N = 50 Neutron Shell

New measurements [l] of CI chondrites for Ni-Ru show a high degree of smoothness of the odd-A solar system abundance curve (SSAC) through the region of the N = 50 closed neutron shell. The resolved s- and r-process peaks at the N = 82 and 126 neutron shells [2] are not apparent for the N = 50 region. Our data confirm the necessity for a single element 89Y SSAC peak, presumably of s-process origin. If the total SSAC is smooth but made of contributions from more than one nucleosynthesis process, then at least the major contributing processes must also have smooth abundance curves. Within errors, a smooths-process abundance (N,) curve can be drawn using N, from Beer and co-workers. For A= 75-85 there are strong "non-s" contributions which could be flat or show a shallow maximum at mass 79-81. (N-N,; suppressed scale). This maximum would be analogous to the "r-process" peaks at A = 129 or 195. The reason that the two-peak structure for N = 50 is not apparent in the total abundance curve is that the lower mass peak is relatively broad, leading to unresolved sand non-speaks in the total SSAC. The rise in the N-N, curve below mass 75 is probably an error in the theoretical N,, so the "non-s" peak is better defined than at first glance. Below mass 69 it is hard to separate the contributions of n-capture nucleosynthesis from the high-mass tail of the iron group nuclei, the origin of which is not well understood

Fabrication and Characterization of Uranium-Molybdenum-Zirconium Alloys

As part of a global effort to convert reactors that require highly enriched uranium to instead operate with low enriched uranium, monolithic fuel plates consisting of a U-Mo fuel meat with a zirconium foil barrier layer and clad in aluminum are being investigated. Interactions have been noted to occur between the fuel meat and the zirconium foil during fuel plate fabrication. These phases must be characterized as part of the fuel qualification process in order to determine potential behavior in a reactor environment; the observed phases are often too small to fully characterize so this study was initiated to characterize the equilibrium phases present in the U-Mo-Zr ternary alloy system. Alloys containing molybdenum (7 wt% and 10 wt%) and zirconium (2 wt%, 5 wt%, and 10 wt%) were fabricated and homogenized at 950°C. They were then subjected to annealing at 650°C for periods of 1, 2, and 5 hours in order to study phase characteristics. Characterization was performed using various techniques including electron-probe micro-analyzer, X-Ray diffraction, and differential scanning calorimetry analysis. Generally, the alloys appeared somewhat similar in terms of microstructure, with the exception of a couple unusual features. A solid solution matrix phase containing intermetallics was typically observed. The density of these intermetallic regions varied with each alloy, but not significantly across varying heat treatments. These intermetallic phases were often observed to have compositions consistent with Mo2Zr, except in U-7Mo-10Zr. In this alloy the precipitates were often consistent with zirconium rich impurity phases; that particular sample could have had an anomalous high impurity composition. One unusual result of the annealing was observed for the U-7Mo-2Zr alloy in back scattered electron imaging. An area that appeared to be a solid solution was visible along grain boundaries for the homogenized sample. This area appeared to be composed of a very dense region of precipitates for the annealed samples. The phase composition was unable to be analyzed due to the very small size of the precipitates. The U-10Mo-5Zr and U-10Mo-10Zr alloys exhibited significant depletion of molybdenum from the matrix phase, while the other alloys exhibited a slight increase in molybdenum. This increase in molybdenum content should contribute to the stability of the γ-phase. The work presented here addresses a knowledge gap in the behavior of the ternary U-Mo-Zr system. Phase evolution and stability of various U-Mo-Zr alloys are examined through casting and heat treating these alloys. Subsequent analyses provide details relevant to the advancement of fuel systems capable of converting many reactors

Relict grains in CAls, revisited

Although the Type B CAI are clearly igneous rocks, they were probably not completely molten (1, 2), thus the possibility exists that preexisting materials can be recognized and characterized. Relict phases were proposed to explain high U and Th concentrations in both melilite and fassaite which would require unreasonably high partition coefficients (D} if due to crystal-liquid partitioning (3). More detailed study showed very rare perovskite grains and enigmatic Ti hot spots in melilite (4). Kuehner et al. (5) subsequently reported very high lithophile trace element contents, including actinides, for fassaite inclusions in melilite which they proposed as relict phases, but Simon et al. (6) show that the fassaite inclusions can be better explained as being the last drops of liquid crystallization. In any case, the original observations and interpretations of (3) still point to an actinide-rich relict host phase. To be able to say what levels of Ti, U, and Th in melilite can be explained by igneous partitioning, we have measured D(mel) for these elements in a synthetic CAI composition under controlled fD_2 conditions, extended down to nebular conditions by carrying out experiments in graphite crucibles in pure CO. Actinide partition coefficients are quite low: D(Th} = 0.008 and D(U) = 0.0007 (possibly a record low in measured D values). The D for trivalent U should be around 0.1-0.3 depending on Ak content as the ionic radius of U^(+3) is similar to La. Thus, for solar nebula fD_2's and CAI compositions less than 1 % of the U is trivalent. The measured D prove that igneous partitioning fails to explain the average U contents of type B CAI melilites, the difference being a factor of 600. D(Ti) is 0.018 at Ak23 and increases with Ak content. D(Ti) is relatively similar in air and at solar nebula fD_2s, surprising given the documented importance of trivalent Ti. In any case, the measured D(Ti) show that melilite Ti levels around 200-300 ppm in early crystallizing melilite can be explained by igneous partitioning, but higher levels would be indicative of resorbed Ti-rich relict phases (e.g., perovskite). To make a closer comparison ofU and Ti in CAI melilites, the fission track images of (3) have been quantitatively mapped at 20 microns resolution for two mm-sized rim and one mantle melilite. High resolution quantitative U distribution data on adjacent fassaites were also obtained. One rim grain shows several U-rich fassaites like those of(5), but the other melilites do not. There are broad U-rich regions in all grains which will be characterized in more detail. The mantle grain is especially rich in detail, but some of this may be correlated with secondary alteration. There is rough correlation ofU content and Ti in the rim grains, but the scale of the Ti analyses, based on electron probe points, is much smaller than that for U. If relict phases, e.g., perovskite, dominate the actinide distributions, they might also affect other lithophile trace elements, e.g., REE. References: (1) Wark D. (1983) thesis. (2) Stolper E. and Paque J. (1986) Geochim., Cosmochim. SO, 2159. (3) Murrell M. and Burnett D. (1987) Geochim. Cosmochim. SI, 985. (4) Johnson M., Burnett D. and Woolum D. (1988) Meteoritics 23, 276. (5) Kuehner S., Davis A. and Grossman L. (1989) Geophys. Res. Lett. 16, 775. (6) Simon S., Davis A. and Grossman L. (1990) LPSC 21, 1161

Relict Refractory Element Rich Phases in Type B CAI

Of the possible processes involved in Type B CAI history, igneous processes are the most tractable for study. Temperature and time scales inferred are commensurate with feasible laboratory simulations. We have previously reported melilite (mel) crystal liquid partition coefficients, Di, for Sm, Yb, Sr (Eu^(++) analog), and Y (Ho analog). Our data for akermanite (Ak) 30 mel compositions is in good agreement with literature data where direct/extrapolated comparisons are possible. Even allowing for significant variations in Di with progressive crystallization, comparisons of predictions for the initial (0-30%) fractional crystallization of mel with our Sr, Y contents obtained for mel cores in Allende Type B CAI, with comparable Ak contents, indicate that the natural data substantially exceed (factors of 1.5-2.5 x) those predicted. Similar results are obtained for Y, Zr in fassaite (fass) based on estimates of the Di from literature data. In this case, excesses of these trace elements are up to factors of about x 5. Thus, while the trace elements observed in natural CAI (Sr in mel and Y, Zr in fass) are in qualitative agreement with igneous partitioning, the trace element abundances are higher than quantitative predictions

The future of Genesis science

Solar abundances are important to planetary science since the prevalent model assumes that the composition of the solar photosphere is that of the solar nebula from which planetary materials formed. Thus, solar abundances are a baseline for planetary science. Previously, solar abundances have only been available through spectroscopy or by proxy (CI). The Genesis spacecraft collected and returned samples of the solar wind for laboratory analyses. Elemental and isotopic abundances in solar wind from Genesis samples have been successfully measured despite the crash of the re‐entry capsule. Here we present science rationales for a set of 12 important (and feasible postcrash) Science and Measurement Objectives as goals for the future (Table 1). We also review progress in Genesis sample analyses since the last major review (Burnett 2013). Considerable progress has been made toward understanding elemental fractionation during the extraction of the solar wind from the photosphere, a necessary step in determining true solar abundances from solar wind composition. The suitability of Genesis collectors for specific analyses is also assessed. Thus far, the prevalent model remains viable despite large isotopic variations in a number of volatile elements, but its validity and limitations can be further checked by several Objectives

Melilite Crystal/Liquid Partitioning of Refractory Lithophiles

The trace element chemistry of CAi's is complicated because of their multistage histories (e.g., Grossman, 1980; Murrell and Burnett, 1987). There is more to CAI origin than just igneous processes, even for Type B inclusions. We have initiated in-situ trace element microdistribution studies of synthetic and natural samples, to determine which aspects of CAI trace element microdistributions are due to igneous processes. Our ultimate goal is to assess those aspects that are not explicable in terms of igneous processes, so as to place constraints on the additional processes involved

Qingzhen and Yamato-691: A tentative alphabet for the EH chondrites

Petrological investigations of unequilibrated EH chondrites revealed the presence of three subgroups. They are identified based on the presence of different concentrations of MnS in niningerite. These differences were produced by partitioning of Mn between niningerite and enstatite as a result of different f_S2 and f_O2 during their formation. In order of increasing MnS-contents and hence increasing f_S2 and decreasing f_O2 these groups are : (A) Yamato (Y)-691 and Abee, (B) Indarch, and (C) Yamato-74370,South Oman, Qingzhen, Kota Kota, Kaidun III, and St. Marks. In the third subgroup the meteorites follow an equilibration and evolution sequence; Y-74370 the most primitive and St. Marks the most equilibrated. Y-691 is the most primitive in its subgroup. Differences in the chemical compositions of minerals in Y-691 and Qingzhen reveal a dichotomy in the compositions of niningerite, djerfisherite, kamacite, and perryite. Niningerites in Y-691 contain the least MnS (3.6-6.7 mole%) and counterparts in Qingzhen the most (12-14 mole%). K/Na ratios in djerfisherite are lower in Qingzhen than in Y-691. The Si concentration in kamacite in Qingzhen is higher than in Y-691. Ni in perryite in Qingzhen is higher than in Y-691. Na and K are highly fractionated between two sulfide lithologies. Na resides mainly in chondrules in caswellsilverite, in a Cl-bearing glass in the chondrules, and in Cr-rich sulfides in the matrix. In contrast, K is confined to djerfisherite, which occurs only in sulfide-rich objects in the matrix, and is highly depleted in chondrules. Two new layer structure minerals were discovered in Y-691 : (a) Na-Cu-Cr-sulfide with the general formula (NaCu) CrS_2,and (b) a Na-Cu-Zn-Cr-sulfide. An evolution scheme was constructed for the EH chondrites in the solar nebula and in their parent bodies. Niningerite and oldhamite condensed first and probably acted as nucleation sites for condensing sulfides, metals and silicates. Both minerals are abundant in chondrules, indicating that chondrule formation preceded all other sulfide- and metal-rich objects. For the first time, planetary metamorphic events were recognized. The Qingzhen Reaction, a breakdown of djerfisherite to troilite, covellite, idaite, bornite, and other unidentified phases, was discovered in Qingzhen and Y-691. Thermal episodes took place in the parent bodies at 1.4 Ba (Qingzhen), and 800 Ma (Y-691). Reverse zoning in niningerite indicates that Fe diffused from troilite to niningerite during the thermal event. In Y-691 sphalerite also formed during the metamorphic episode due to mobilization of Zn (and other volatiles). EH chondrites condensed in a chemically inhomogeneous region of the solar nebula where considerable variations in sulfur and oxygen fugacities existed