Electronic structure of nanoscale iron oxide particles measured by scanning tunneling and photoelectron spectroscopies

We have investigated the electronic structure of nano-sized iron oxide by scanning tunnelling microscopy (STM) and spectroscopy (STS) as well as by photoelectron spectroscopy. Nano particles were produced by thermal treatment of Ferritin molecules containing a self-assembled core of iron oxide. Depending on the thermal treatment we were able to prepare different phases of iron oxide nanoparticles resembling gamma-Fe2O3, alpha-Fe2O3, and a phase which apparently contains both gamma-Fe2O3 and alpha-Fe2O3. Changes to the electronic structure of these materials were studied under reducing conditions. We show that the surface band gap of the electronic excitation spectrum can differ from that of bulk material and is dominated by surface effects.Comment: REVTeX, 6 pages, 10 figures, submitted to PR

Ferredoxin circular dichroism at 3600 cm-1

A very broad circular dichroism band is observed in reduced spinach ferredoxin at 3600 cm-1. The maximum [Delta][var epsilon] is +1.1 M-1 [middle dot] cm-1. The rotational strength is if+1.0 [middle dot] 10-39 merg [middle dot] cm3 (+0.11 Debye-Bohr magneton); the minimum magnetic transition dipole moment is 0.14 Bohr magneton. These values are roughly consistent with expectations for a d --> d transition of tetrahedrally coordinated Fe2+.No CD is detected in the oxidized protein between 5000 and 2800 cm-1.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22253/1/0000689.pd

El desarrollo y evaluación la declaración del problema de investigación = (Development and evaluation of problem definition in research)

Abstract. The article analyses the problems associated with the development of research statement and with the evaluation of development competency and its transcendental impact on a positivist research. Problem statements derived from three main scientific paradigms: Positivist, interpretative and constructive approaches are presented with their implications in scientific research. Characteristics, positioning and functions of a problem statement are also studied. A detailed methodology for problem statement characterization is included as well as a procedure (guideline) and a method for its competency development evaluation. Resumen. El presente artículo analiza la problemática que se presenta tanto en el desarrollo como en la evaluación de la competencia relativa a la declaración de un problema y la trascendencia que tiene en una investigación con enfoque positivista. En los enfoques de la declaración de un problema se presentan los supuestos de los tres principales paradigmas científicos: positivista, interpretativo y constructivo y las implicaciones que tienen en una declaración de problema de investigación en la investigación científica. Se presentan las características, ubicación y funciones de una declaración del problema. Se incluye además una metodología detallada para la caracterización de una declaración del problema, así como un procedimiento (guía) y un método para evaluar el desarrollo de la declaración de un problema visto como competencia

The Molloy Student Literary Magazine Volume 8

The Molloy Student Literary Magazine, sponsored by Molloy College’s Office of Student Affairs, is devoted to publishing the best previously unpublished works of prose, poetry, drama, literary review, criticism, and other literary genres, that the Molloy student community has to offer. The journal welcomes submissions, for possible publication, from currently enrolled Molloy students at all levels. In this issue, we are including the three winners of the annual Patricia Sullivan Common Reading Contest: Inspired Works - Building Community. All submitted work will undergo a review process initiated by the Managing Editor prior to a decision being made regarding publication of said work. Given sufficient content, The Molloy Student Literary Magazine is published twice annually in Spring and Fall. Interested contributors from the currently enrolled Molloy student community should send work via e-mail attachment and brief cover letter (including a two-sentence biographical statement) to: Dr. Damian Ward Hey, Managing Editor, The Molloy Student Literary Magazine: [email protected]. Enrolled students who are interested in becoming members of The Molloy Student Literary Magazine staff may e-mail letters of inquiry. Excelsior!https://digitalcommons.molloy.edu/eng_litmag/1000/thumbnail.jp

Coordinated Unmanned Aircraft System (UAS) and Ground-Based Weather Measurements to Predict Lagrangian Coherent Structures (LCSs)

Concentrations of airborne chemical and biological agents from a hazardous release are not spread uniformly. Instead, there are regions of higher concentration, in part due to local atmospheric flow conditions which can attract agents. We equipped a ground station and two rotary-wing unmanned aircraft systems (UASs) with ultrasonic anemometers. Flights reported here were conducted 10 to 15 m above ground level (AGL) at the Leach Airfield in the San Luis Valley, Colorado as part of the Lower Atmospheric Process Studies at Elevation—a Remotely-Piloted Aircraft Team Experiment (LAPSE-RATE) campaign in 2018. The ultrasonic anemometers were used to collect simultaneous measurements of wind speed, wind direction, and temperature in a fixed triangle pattern; each sensor was located at one apex of a triangle with ∼100 to 200 m on each side, depending on the experiment. A WRF-LES model was used to determine the wind field across the sampling domain. Data from the ground-based sensors and the two UASs were used to detect attracting regions (also known as Lagrangian Coherent Structures, or LCSs), which have the potential to transport high concentrations of agents. This unique framework for detection of high concentration regions is based on estimates of the horizontal wind gradient tensor. To our knowledge, our work represents the first direct measurement of an LCS indicator in the atmosphere using a team of sensors. Our ultimate goal is to use environmental data from swarms of sensors to drive transport models of hazardous agents that can lead to real-time proper decisions regarding rapid emergency responses. The integration of real-time data from unmanned assets, advanced mathematical techniques for transport analysis, and predictive models can help assist in emergency response decisions in the future

The velocity dispersion and mass function of the outer halo globular cluster Palomar 4

We obtained precise line-of-sight radial velocities of 23 member stars of the remote halo globular cluster Palomar 4 (Pal 4) using the High Resolution Echelle Spectrograph (HIRES) at the Keck I telescope. We also measured the mass function of the cluster down to a limiting magnitude of V~28 mag using archival HST/WFPC2 imaging. We derived the cluster's surface brightness profile based on the WFPC2 data and on broad-band imaging with the Low-Resolution Imaging Spectrometer (LRIS) at the Keck II telescope. We find a mean cluster velocity of 72.55+/-0.22 km/s and a velocity dispersion of 0.87+/-0.18 km/s. The global mass function of the cluster, in the mass range 0.55<=M<=0.85 M_solar, is shallower than a Kroupa mass function and the cluster is significantly depleted in low-mass stars in its center compared to its outskirts. Since the relaxation time of Pal 4 is of the order of a Hubble time, this points to primordial mass segregation in this cluster. Extrapolating the measured mass function towards lower-mass stars and including the contribution of compact remnants, we derive a total cluster mass of 29800 M_solar. For this mass, the measured velocity dispersion is consistent with the expectations of Newtonian dynamics and below the prediction of Modified Newtonian Dynamics (MOND). Pal 4 adds to the growing body of evidence that the dynamics of star clusters in the outer Galactic halo can hardly be explained by MOND.Comment: 17 pages, accepted for publication in MNRAS; Fig. 8 surface brightness/density data at github.com/matthiasjfrank/pal4_surface_brightnes

The relationship between construction sector and the national economy of Sri Lanka

The causal relationship between construction and a country’s economy has received much attention in the past. However, the results provide contrasting views on the nature of this relationship. This paper therefore investigates the direction of the causal relationship between construction and the economy of a developing country, Sri Lanka. It uses empirical data for selected economic and construction indicators for the period 1990–2009. The pattern of the causal relationship was determined using Granger causality test. The findings reveal that for all indicators except construction investment, national economic activities precede that of construction. The study therefore concludes and strengthens the body of knowledge on Sri Lanka that the causal relationship between its construction sector and national economy tend towards a uni-directional relationship with the national economy inducing growth in the construction sector and not vice versa