Synthesis and characterization of novel ternary and quaternary reduced molybdenum oxides

Novel ternary reduced molybdenum oxides containing infinite chains of trans edge-shared molybdenum octahedra have been well explored. In the past decade, synthetic efforts have examined cutting these infinite chains of Mo octahedra into smaller segments, termed oligomers. The oligomers can be formulated from the general formula, M[subscript]n-xMo[subscript]4n+2O[subscript]6n+4, where n equals the number of trans edge-shared Mo octahedra. The major emphasis of this research was to synthesize and characterize tetrameric oligomers, where n = 4. New oligomeric materials with n = 2,3,4, & 5 were discovered. These members are: K[subscript]0.06M[subscript]1.94MO[subscript]10O[subscript]16 (M = Ca,Sr), K[subscript]0.33Gd[subscript]1.67Mo[subscript]10O[subscript]16, SrBaMo[subscript]10O[subscript]16, K[subscript]1.29Sn[subscript]1.71Mo[subscript]140[subscript]22, K[subscript]1.66Pb[subscript]1.34Mo[subscript]14O[subscript]22, K[subscript]2.6Sr[subscript]0.4MO[subscript]14O[subscript]22, Ba[subscript]3Mo[subscript]18O[subscript]28, and K[subscript]0.19Ba[subscript]3.81Mo[subscript]22O[subscript]34.;The structural features and properties of the oligomers were compared and contrasted in terms of electron counting methods. The dimeric oligomers have a consistent, strong apical Mo-Mo bond and a very strong intercluster metal-metal bond that varies in length based on electron count. For the trimeric oligomers, the apical-apical bonds are arranged in a short-long fashion for the members with less than 44e[superscript]- and the apical-apical bonds become nearly equivalent for materials with greater than 44e[superscript]-. The intercluster metal-metal bonds for the n = 3 members are long if less than 43e[superscript]- are available, short if between 43 and 44e[superscript]-, and long if greater than 44e[superscript]-. The n = 4 oligomer, Ba[subscript]3Mo[subscript]18O[subscript]28, has four short and two long apical-apical bonds and a long intercluster bond. K[subscript]0.19Ba[subscript]3.81Mo[subscript]22O[subscript]34, the n = 5 member, has four short and four long apical-apical bonds and a long intercluster metal-metal distance;Two ternary reduced molybdenum oxide phases containing infinite chains of trans edge-shared Mo octahedra, connected in different manners, were prepared and characterized. The two materials are Ti[subscript]0.31Fe[subscript]1.69Mo[subscript]4O[subscript]7 and RE[subscript]4Mo[subscript]4O[subscript]11, where RE = Y, Nd, and Sm-Lu;Many of the known ternary and quaternary reduced molybdenum oxides have superstructural ordering, due in part, to mixed metal and/or partial occupation of cation sites. Transmission electron microscopy was used to explore the superstructures present in Fe[subscript]1.89Mo[subscript]4.11O[subscript]7, Sn[subscript]0.9Mo[subscript]4O[subscript]6, InMo[subscript]4O[subscript]6, and Mn[subscript]1.5Mo[subscript]8O[subscript]11. Proposed structural models consistent with the observed electron diffraction were presented

How an Experience in Nature Affects Ecoliteracy of High School Students

Ecological literacy, also termed ecoliteracy, is the understanding of the principles of organization that sustain life. It takes into account not only the knowledge that a person has about the environment, but also the person’s attitudes and behaviors towards the environment. Ecoliterate individuals have an understanding of ecological topics and a desire to solve problems that have been inflicted on the planet. The purpose of this study was to investigate how an experience at a residential environmental learning center in northern Minnesota affects the ecoliteracy of high school students. High school students (n = 28) from a small, southeastern Minnesota high school spent three days participating in hands­on learning opportunities that increased their knowledge and connected them more with nature. Analysis of pre­ and posttests, detailed daily journal entries and focus group interviews allowed for comparisons to be made in four categories: grade, gender, ethnicity and previous participation in the field experience. On average, students showed in increase of 15 percent in their ecoliteracy score over the course of the three days

Nova dimenzija u geometrijskom obrazovanju

This paper describes the course "Methods of representation" that has evolved at the Faculty of Architecture in Graz in conjunction with developments in the modern practice of architectural design. We established web sites (http://www.geometrie.tugraz.at/lehre/dm_ue03/ and http://ikg.tugraz.at/dm0/ws04/), which include the introduction in teaching, tutorials and VRLM animations to help students understanding space geometry. The course focuses on classical geometrical representation methods, solid modelling in CAD and geometrical freehand drawing. Each of these parts will be worked out and examples of student exercises will complete the paper.U članku se daje prikaz kolegija "Metode prezentacije", koji se predaje na Arhitektonskom fakultetu u Grazu, a čiji je sadržaj usko povezan sa suvremenim arhitektonskim projektiranjem. Izradene su web stranice (http://www.geometrie.tugraz.at/lehre/dm ue03/ i http://ikg.tugraz.at/dm0/ws04/), koje upoznaju studente s predavanjima, vode ih kroz materiju i pružaju VRLM animacije u namjeri da im se pomogne razumjeti geometriju prostora. U kolegiju se stavlja naglasak na klasične geometrijske konstrukcije, 3D modeliranje s CAD podrškom i prostoručno crtanje. Svaki od ovih dijelova se zasebno razraduje i upotpunjuje s primjerima studentskih programa

Parea: multi-view ensemble clustering for cancer subtype discovery

Multi-view clustering methods are essential for the stratification of patients into sub-groups of similar molecular characteristics. In recent years, a wide range of methods has been developed for this purpose. However, due to the high diversity of cancer-related data, a single method may not perform sufficiently well in all cases. We present Parea, a multi-view hierarchical ensemble clustering approach for disease subtype discovery. We demonstrate its performance on several machine learning benchmark datasets. We apply and validate our methodology on real-world multi-view cancer patient data. Parea outperforms the current state-of-the-art on six out of seven analysed cancer types. We have integrated the Parea method into our developed Python package Pyrea (https://github.com/mdbloice/Pyrea), which enables the effortless and flexible design of ensemble workflows while incorporating a wide range of fusion and clustering algorithms

Exciton-phonon coupling in individual GaAs nanowires studied using resonant Raman spectroscopy

The Fröhlich coupling strength of individual GaAs nanowires is investigated by resonant micro-Raman spectroscopy measurements near the direct bandgap E[subscript g]2. Large 2LO/1LO intensities up to 5.7 are observed in an individual GaAs nanowire. A 2LO resonance profile of the GaAs nanowire agrees well with a two-phonon-scattering model, suggesting excitonic scattering. These results advance the understanding of electron-phonon coupling and exciton scattering in quasi-one-dimensional systems and in GaAs at E[subscript g], allowing for the development and optimization of nanowire optoelectronic devices

Measurement and Simulation of Permeation and Diffusion in Native and Cultivated Tissue Constructs

Characterization of native skin or cultured 3D skin models with respect to permeability plays an important role for the development and testing of pharmaceuticals and cosmetics. Extensive efforts have been dedicated to determining the key parameters describing permeability and diffusion. Whereas respective methods are well established for native skin biopsies, only few are available for 3D skin models, as these have usually much lower dimensions. In this chapter, some fundamentals about permeation and diffusion as well as state of the art of measurement methods used for skin biopsies are summarized. An alternative method for the determination of the permeation in a membrane insert system and the use of a modular simulation to support permeability studies is presented and discussed