441 research outputs found
Connecting Youth to Public Lands Through the Social Change Model of Leadership Development: The Yosemite Leadership Program
This qualitative study explored the success and outcome of the Yosemite Leadership Program (YLP) through its foundation in the Social Change Model of Leadership Development. There are research studies of collegiate programming and the Social Change Model (SCM); however, a literature review uncovered the limited amounts of research around leadership programming connecting collegiate students to their gateway public lands sites. The goal of this research was to identify how the SCM could be used to implement methods and practices of leadership development with college students in partnership with a public lands agency. The specific leadership development themes that were explored included connecting youth to their public lands, having them evaluate their own leadership journey, facilitating their development of the courage to move beyond their comfort zones, and having them evaluate why this type of program is so critical. These themes were garnered from the interviews with program managers, participants, and alumni. The research led to the development of the Public Lands Social Change Model of Leadership Development. This model employed a set of tertiary codes from the SCM to categorize the participants’ knowledge and experiences. This research also includes recommendations for future collegiate programming connecting youth to their public lands. The following critical components for youth programming were observed. First, communication is foundational for individuals, groups, and community members moving towards positive change. Next, collaboration and partnerships are important because they provide resources, networking, and motivation for participants. Finally, a sense of community and belonging among the participants is crucial for building safe spaces and friendships. Participants were particularly grateful for the cohort family dynamics that developed through the program. The YLP is a win/win for the students, universities, natural resources agencies, and society as a whole since programs like this results in a greater motivation for college retention and degree completion for these at risk students as well as an enhanced connection to parks and natural areas facilitating their develop as future leaders in natural resources conservation
High Resolution Electron Beam Induced Current Measurements in an Scanning Tunneling Microscope on GaAs-MESFET
Recently, the first results of electron beam induced current (EBIC) measurements in a scanning tunneling microscope (STM) have been reported. Although the acquired results match with those obtained in conventional EBIC investigations, the interpretation of the obtained results is still restricted solely to a qualitative discussion. In this paper, a quantitative approach is used for two-dimensional numerical simulations of induced currents in GaAs-MESFET leading to a first starting point for a sophisticated interpretation of the dependence of induced currents on experimental and device parameters
Marketing klastrowy
Celem artykułu jest charakterystyka zasad funkcjonowania marketingu klastrowego oraz zaprezentowanie metod oceny sytuacji społeczno-ekonomicznej klastrów. Hipoteza badawcza sformułowana na podstawie wnikliwej obserwacji sposobów zarzadzania w klastrach, została wyrażona za pomocą następującego zdania. Istnieją dziedziny działalności: władz samorządowych, instytucji oraz podmiotów gospodarczych, które wymagają współpracy marketingowej
LOADS ACTING ON THE LOCOMOTIVE SYSTEM OF PROFESSIONAL FEMALEVOLLEYBALL PLAYERS DURING THE LANDING PHASE OF SPIKES AND BLOCKS
The purpose of this study was to identify force and time characteristics of ground reaction forces produced during the landing phase of volleyball technical elements: blocks and spikes. Applying piezoelectric dynamometry and video recording, a series of tests were carried out with the participation of four female volleyball players of the first team of AZS AWF sports club competing in the Female Volleyball League. The recorded force vs time line graphs of ground reaction Rx(t), Ry(t) and Rz(t) were used to calculate the values of kinematic-dynamic parameters that describe the level of dynamic loads. Results show that the majority of loads in these movement tasks is significant and may be traumatogenic
Development of an Scanning Tunneling Microscopy-Based Electron Beam Induced Current (EBIC) Microscope
Measurements of electron beam induced currents (EBIC) can either be performed in a scanning electron microscope (SEM) or in a scanning tunneling microscope (STM), since both microscopes are very similar in their basic assembly. However, a straightforward application of an STM in EBIC-measurements, i.e. the use of a microscope tip as a fine source for low energetic electrons is not possible due to the specific demands on the instrument in an EBIC application. The present paper gives a compilation of these demands and describes their conversion into an optimized STM-EBIC microscope
Discrimination between FRET and non-FRET quenching in a photochromic CdSe quantum dot/dithienylethene dye system
A photochromic Förster resonance energy transfer (FRET) system was employed to disentangle the fluorescence quenching mechanisms in quantum dot/photochromic dye hybrids. In the off-state of the dye the main quenching mechanism is FRET whereas the moderate quenching in the on-state is due to non-FRET pathways opened up upon assembly
Kids These Days: Increasing Youth Engagement in Community Heritage and Social Justice Through the Implementation of a Youth Participatory Empowerment Model
The purpose of this co-authored, qualitative, action research study was to examine how to empower youth to become active participants in their communities. Citizen engagement in community and public life is vital to a healthy democracy and young people have a unique place in community citizenry, but are often dismissed or excluded from decision-making. The research team developed a model, the Youth Participatory Empowerment Model (YPEM), to guide youth through a process of identifying and engaging a community heritage or social justice need in their community. The team assembled a guidebook of activities to engage groups in difficult self, group, and community work. To test the model, each of the six members of the research team implemented YPEM to engage youth in six locations throughout the United States. The members of each group represent a diverse sampling of the country and include tribal, undocumented, rural, suburban, and urban youth from low income or underserved populations. Researchers collected interview and observation data to identify themes and strategies that support community youth leadership. The model seeks to cultivate youth voice, youth engagement, and youth empowerment and to assist group mentors with this process. The results of the six groups highlight the importance of youth leadership, trust and safety, partnerships, and multidimensional mentorship. These observations led to the development of an updated version of YPEM, which includes the four main observations and strategies that proved successful in the field
Absolute dimensions of eclipsing binaries. XXVIII. BK Pegasi and other F-type binaries: Prospects for calibration of convective core overshoot
We present a detailed study of the F-type detached eclipsing binary BK Peg,
based on new photometric and spectroscopic observations. The two components,
which have evolved to the upper half of the main-sequence band, are quite
different with masses and radii of (1.414 +/- 0.007 Msun, 1.988 +/- 0.008 Rsun)
and (1.257 +/- 0.005 Msun, 1.474 +/- 0.017 Rsun), respectively. The 5.49 day
period orbit of BK Peg is slightly eccentric (e = 0.053). The measured
rotational velocities are 16.6 +/- 0.2 (primary) and 13.4 +/- 0.2 (secondary)
km/s. For the secondary component this corresponds to (pseudo)synchronous
rotation, whereas the primary component seems to rotate at a slightly lower
rate. We derive an iron abundance of [Fe/H] =-0.12 +/- 0.07 and similar
abundances for Si, Ca, Sc, Ti, Cr and Ni. Yonsei-Yale and Victoria-Regina
evolutionary models for the observed metal abundance reproduce BK Peg at ages
of 2.75 and 2.50 Gyr, respectively, but tend to predict a lower age for the
more massive primary component than for the secondary. We find the same age
trend for three other upper main-sequence systems in a sample of well studied
eclipsing binaries with components in the 1.15-1.70 Msun range, where
convective core overshoot is gradually ramped up in the models. We also find
that the Yonsei-Yale models systematically predict higher ages than the
Victoria-Regina models. The sample includes BW Aqr, and as a supplement we have
determined a [Fe/H] abundance of -0.07 +/- 0.11 for this late F-type binary. We
propose to use BK Peg, BW Aqr, and other well-studied 1.15-1.70 Msun eclipsing
binaries to fine-tune convective core overshoot, diffusion, and possibly other
ingredients of modern theoretical evolutionary models.Comment: Accepted for publication in Astronomy and Astrophysic
Four-colour photometry of eclipsing binaries. XLI uvby light curves for AD Bootis, HW Canis Majoris, SW Canis Majoris, V636 Centauri, VZ Hydrae, and WZ Ophiuchi
CONTEXT: Accurate mass, radius, and abundance determinations from binaries
provide important information on stellar evolution, fundamental to central
fields in modern astrophysics and cosmology.
AIMS: Within the long-term Copenhagen Binary Project, we aim to obtain
high-quality light curves and standard photometry for double-lined detached
eclipsing binaries with late A, F, and G type main-sequence components, needed
for the determination of accurate absolute dimensions and abundances, and for
detailed comparisons with results from recent stellar evolutionary models.
METHODS: Between March 1985 and July 2007, we carried out photometric
observations of AD Boo, HW CMA, SW CMa, V636 Cen, VZ Hya, and WZ Oph at the
Str"omgren Automatic Telescope at ESO, La Silla.
RESULTS: We obtained complete uvby light curves, ephemerides, and standard
uvby\beta indices for all six systems.For V636 Cen and HW CMa, we present the
first modern light curves, whereas for AD Boo, SW CMa, VZ Hya, and WZ Oph, they
are both more accurate and more complete than earlier data. Due to a high
orbital eccentricity (e = 0.50), combined with a low orbital inclination (i =
84.7), only one eclipse, close to periastron, occurs for HW CMa. For the two
other eccentric systems, V636 Cen (e = 0.134) and SW CMa (e = 0.316), apsidal
motion has been detected with periods of 5270 +/- 335 and 14900 +/- 3600 years,
respectively.Comment: Only change is: Bottom lines (hopefully) not truncated anymore.
Accepted for publication in Astonomy & Astrophysic
Radial Velocity Studies of Close Binary Stars. XV
Radial-velocity measurements and sine-curve fits to the orbital radial
velocity variations are presented for the last eight close binary systems
analyzed the same way as in the previous papers of this series: QX And, DY Cet,
MR Del, HI Dra, DD Mon, V868 Mon, ER Ori, and Y Sex. For another seven systems
(TT Cet, AA Cet, CW Lyn, V563 Lyr, CW Sge, LV Vir and MW Vir) phase coverage is
insufficient to provide reliable orbits but radial velocities of individual
components were measured. Observations of a few complicated systems observed
throughout the DDO close-binary program are also presented; among them an
especially interesting is the multiple system V857 Her which - in addition to
the contact binary - very probably contains one or more sub-dwarf components of
much earlier spectral type. All suspected binaries which were found to be most
probably pulsating stars are briefly discussed in terms of mean radial
velocities and projected rotation velocities (v sin i) as well as spectral type
estimates. In two of them, CU CVn and V752 Mon, the broadening functions show a
clear presence of non-radial pulsations. The previously missing spectral types
for the DDO I paper are given here in addition to such estimates for most of
the program stars of this paper.Comment: submitted to A
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