Teacher Responsibility: Its Meaning, Measure, and Educational Implications.

Teachers’ personal sense of responsibility potentially influences their instructional practices, psychological well-being, and ultimately their students’ learning and performance. Furthermore, the assumption that teachers are personally responsible, or that they should assume personal responsibility for their students’ educational outcomes—primarily test performance—is at the core of high-impact educational policies such as the implementation of accountability systems in American schools. Yet, the extant literature on teacher responsibility is plagued by conceptual and operational ambiguity: the term responsibility has been used interchangeably with related constructs such as internal locus of control, measurement instruments have incorporated items originally designed to assess other constructs such as efficacy, and have generally failed to acknowledge the multidimensional nature of teacher responsibility, and the literature lacks a comprehensive and consistent definition of the term. Accordingly, this multiple manuscript dissertation begins with a review of the theoretical status of teacher responsibility in the context of current education policy and a comprehensive definition of the term. The second manuscript is an empirical study focusing on the measurement of teacher responsibility that (a) reviews existing measures of teacher responsibility, (b) introduces a multidimensional assessment of teacher responsibility for critical educational outcomes such as student motivation, student achievement, for having positive relationships with students, and for providing high quality instruction (the Teacher Responsibility Scale), and (c) demonstrates that teacher responsibility and teacher efficacy are conceptually and empirically distinct. The third manuscript examines how teachers conceptualize their professional responsibility and how they perceive its antecedents and consequences. The concluding chapter discusses the current status of teacher responsibility research, and outlines directions for future research.PHDEducation & PsychologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/99839/1/fanim_1.pd

Cu In,Ga Se2 surface treatment with Na and NaF A combined photoelectron spectroscopy and surface photovoltage study in ultra high vacuum

Either metallic Na or NaF were deposited onto Cu In,Ga Se2 surfaces and studied by photoelectron spectroscopy and surface photovoltage spectroscopy without breaking the ultra high vacuum. The deposition of elemental Na at room temperature led to the formation of an intermediate Cu and Ga rich layer at the CIGSe surface, whereas for NaF the composition of the CIGSe surface remained unchanged. A metal like surface induced by an inverted near surface region with a reduced number of defect states was formed after the deposition of Na. Under the chosen experimental conditions, the near surface layer was independent on the amount of Na and stable in time. In contrast, the usage of NaF weakened the inversion and led to an increased band bending compared to the untreated CIGSe sample. The SPV signals decreased with proceeding time after the deposition of NaF

Green Light Photoelectrocatalysis with Sulfur-Doped Carbon Nitride: Using Triazole-Purpald for Enhanced Benzylamine Oxidation and Oxygen Evolution Reactions

Materials dictate carbon neutral industrial chemical processes. Visible-light photoelectrocatalysts from abundant resources will play a key role in exploiting solar irradiation. Anionic doping via pre-organization of precursors and further co-polymerization creates tuneable semiconductors. Triazole derivative-purpald, an unexplored precursor with sulfur (S) container, combined in different initial ratios with melamine during one solid-state polycondensation with two thermal steps yields hybrid S-doped carbon nitrides (C3N4). The series of S-doped/C3N4-based materials show enhanced optical, electronic, structural, textural, and morphological properties and exhibit higher performance in organic benzylamine photooxidation, oxygen evolution, and similar energy storage (capacitor brief investigation). 50M-50P exhibits the highest photooxidation conversion (84 +/- 3%) of benzylamine to imine at 535 nm - green light for 48 h, due to a discrete shoulder (approximate to 700) nm, high sulfur content, preservation of crystal size, new intraband energy states, structural defects by layer distortion, and 10-16 nm pores with arbitrary depth. This work innovates by studying the concomitant relationships between: 1) the precursor decomposition while C3N4 is formed, 2) the insertion of S impurities, 3) the S-doped C3N4 property-activity relationships, and 4) combinatorial surface, bulk, structural, optical, and electronic characterization analysis. This work contributes to the development of disordered long-visible-light photocatalysts for solar energy conversion and storage

Nickel on nitrogen doped carbon pellets for continuous flow hydrogenation of biomass derived compounds in water

Hydrogenation reactions in water at elevated temperatures are challenging for heterogeneous catalyst. Thus, we present a simple, cheap, scalable, and sustainable approach for synthesizing an efficient and water-tolerant Ni catalyst supported on highly porous nitrogen-doped carbon (NDC) in pellet shape. The performance of this catalyst was evaluated in the aqueous-phase hydrogenation of lignocellulosic biomass-derived compounds, i.e., glucose (Glu), xylose (Xyl) and vanillin (V), using a continuous-flow system. The prepared 35 wt.- Ni on NDC catalyst exhibited a high catalytic performance in all three different aqueous-phase hydrogenation reactions, i.e., conversion of Glu, Xyl and V was 96.3 mol, 85 mol and 100 mol and yield of sorbitol (Sor), xylitol (Xyt) and 2-methoxy-4-methylphenol (MMP) was 82 mol, 62 mol and 100 mol, respectively. This high activity was attributed to heterojunction effects stabilizing and adjusting the homogenously dispersed Ni nanoparticles on the surface of NDC. Changing the electron density in the Nickel nanoparticle allows high performance of the catalyst under long time of stream (7 to 30 h) with minimized Ni leaching

In Situ Synthesis of Molybdenum Carbide Nanoparticles Incorporated into Laser Patterned Nitrogen Doped Carbon for Room Temperature VOC Sensing

Carbon laser patterning CLaP is emerging as a new tool for the precise and selective synthesis of functional carbon based materials for on chip applications. The aim of this work is to demonstrate the applicability of laser patterned nitrogen doped carbon LP NC for resistive gas sensing applications. Films of pre carbonized organic nanoparticles on polyethylenetherephthalate are carbonized with a CO2 laser. Upon laser irradiation a compositional and morphological gradient in the films is generated with a carbon content of 92 near the top surface. The specific surface areas of the LP NC are increased by introducing sodium iodide NaI as a porogen. Electronic conductivity and surface area measurements corroborate the deeper penetration of the laser energy into the film in the presence of NaI. Furthermore, impregnation of LP NC with MoC1 x lt;10 nm nanoparticles is achieved by addition of ammonium heptamolybdate into the precursor film. The resulting doping sensitive nano grain boundaries between p type carbon and metallic MoC1 x lead to an improvement of the volatile organic compounds sensing response of Delta R R0 3.7 or 0.8 for 1250 ppm acetone or 900 ppm toluene at room temperature, respectively, which is competitive with carbon based sensor materials. Further advances in sensitivity and in situ functionalization are expected to make CLaP a useful method for printing selective sensor array

Silicon-organic hybrid (SOH) devices and their use in comb-based communication systems

Advanced wavelength-division multiplex-ing (WDM) requires both efficient multi-wavelength light sources to generate optical carriers and highly scalable photonic-electronic interfaces to encode data on these carriers. In this paper, we give an overview on our recent progress regarding silicon-organic hy-brid (SOH) integration and comb-based WDM transmission

Comprehensive Comparison of Various Techniques for the Analysis of Elemental Distributions in Thin Films

The present work shows results on elemental distribution analyses in Cu(In,Ga)Se2 thin films for solar cells performed by use of wavelength-dispersive and energy-dispersive X-ray spectrometry (EDX) in a scanning electron microscope, EDX in a transmission electron microscope, X-ray photoelectron, angle-dependent soft X-ray emission, secondary ion-mass (SIMS), time-of-flight SIMS, sputtered neutral mass, glow-discharge optical emission and glow-discharge mass, Auger electron, and Rutherford backscattering spectrometry, by use of scanning Auger electron microscopy, Raman depth profiling, and Raman mapping, as well as by use of elastic recoil detection analysis, grazing-incidence X-ray and electron backscatter diffraction, and grazing-incidence X-ray fluorescence analysis. The Cu(In,Ga)Se2 thin films used for the present comparison were produced during the same identical deposition run and exhibit thicknesses of about 2 μm. The analysis techniques were compared with respect to their spatial and depth resolutions, measuring speeds, availabilities, and detection limit

Ty1 integrase overexpression leads to integration of non-Ty1 DNA fragments into the genome of Saccharomyces cerevisiae

The integrase of the Saccharomyces cerevisiae retrotransposon Ty1 integrates Ty1 cDNA into genomic DNA likely via a transesterification reaction. Little is known about the mechanisms ensuring that integrase does not integrate non-Ty DNA fragments. In an effort to elucidate the conditions under which Ty1 integrase accepts non-Ty DNA as substrate, PCR fragments encompassing a selectable marker gene were transformed into yeast strains overexpressing Ty1 integrase. These fragments do not exhibit similarity to Ty1 cDNA except for the presence of the conserved terminal dinucleotide 5′-TG-CA-3′. The frequency of fragment insertion events increased upon integrase overexpression. Characterization of insertion events by genomic sequencing revealed that most insertion events exhibited clear hallmarks of integrase-mediated reactions, such as 5 bp target site duplication and target site preferences. Alteration of the terminal dinucleotide abolished the suitability of the PCR fragments to serve as substrates. We hypothesize that substrate specificity under normal conditions is mainly due to compartmentalization of integrase and Ty cDNA, which meet in virus-like particles. In contrast, recombinant integrase, which is not confined to virus-like particles, is able to accept non-Ty DNA, provided that it terminates in the proper dinucleotide sequence

40 GBd 16QAM signaling at 160 Gb/s in a silicon-organic hybrid modulator

We demonstrate for the first time generation of 16-state quadrature amplitude modulation (16QAM) signals at a symbol rate of 40 GBd using silicon-based modulators. Our devices exploit silicon-organic hybrid (SOH) integration, which combines silicon-on-insulator slot waveguides with electro-optic cladding materials to realize highly efficient phase shifters. The devices enable 16QAM signaling and quadrature phase shift keying (QPSK) at symbol rates of 40 GBd and 45 GBd, respectively, leading to line rates of up to 160 Gbit/s on a single wavelength and in a single polarization. This is the highest value demonstrated by a silicon-based device up to now. The energy consumption for 16QAM signaling amounts to less than 120 fJ/bit – one order of magnitude below that of conventional silicon photonic 16QAM modulators