709 research outputs found
Diffeological Coarse Moduli Spaces of Stacks over Manifolds
In this paper, we consider diffeological spaces as stacks over the site of
smooth manifolds, as well as the "underlying" diffeological space of any stack.
More precisely, we consider diffeological spaces as so-called concrete sheaves
and show that the Grothendieck construction sending these sheaves to stacks has
a left adjoint: the functor sending any stack to its diffeological coarse
moduli space. As an application, we restrict our attention to differentiable
stacks and examine the geometry behind the coarse moduli space construction in
terms of Lie groupoids and their principal bundles. Additionally, we define
basic differential forms for stacks and confirm in the differentiable case that
these agree (under certain conditions) with basic differential forms on a
representative Lie groupoid. These basic differentiable forms in turn match the
diffeological forms on the orbit space.Comment: 16 pages; v4: besides some minor changes, the abstract was rewritten
and we added an application to the differentiable stack section. v3:
condensed the presentation and added more information to the introduction.
(Also changed the title.
Physics of electro-thermal effects in ESD protection devices
Damage in ESD protection devices can be caused by high local temperatures resulting from heat generation by an ESD pulse. In order to obtain physical insight into the process that leads to permanent damage, device simulations of coupled thermal and electrical behaviour have been performed. Additional to the potential and the electron and hole concentrations the lattice temperature is solved as a variable. Simulations of ESD pulses (forward bias) applied to a diode have been performed. The discharge mechanism could be visualised by using the coupled thermal/electrical model. Locations with considerable temperature rise that eventually lead to damage can be extracted from the calculated temperature distributions. Protection devices with optimum electrical and thermal characteristics can be designed by adjusting doping profiles and layout parameters. The buried layer of the protection device does not contribute in conducting current at high current levels. Therefore the buried layer is not functional in diodes that are subjected to ESD in forward bias. Measurements determining the ESD vulnerability of protection devices with and without buried layer confirm this fact
Trends in Nectar Concentration and Hummingbird Visitation: Investigating different variables in three flowers of the Ecuadorian Cloud Forest: Guzmania jaramilloi, Gasteranthus quitensis, and Besleria solanoides
Many variables affect hummingbird visitation to flowers, including nectar concentration, time of day, corolla length and other aspects of flower morphology, and elevation. Nectar concentration was measured from flowers of three Ecuadorian subtropical montane species: Guzmania jaramilloi, Gasteranthus quitensis, and Besleria solanoides. Concentration values were compared across varying times of day, corolla lengths, and elevations to determine the effects of these variables on flower nectar concentration. Camera traps were also used to observe hummingbird visitation to the above three flower species. After running regression and ANOVA analyses, nectar concentration was found to be positively correlated with time of day, negatively correlated with corolla length, and negatively correlated with elevation. Additionally, both flower morphology and elevation were determined to affect the species of hummingbirds that visited each flower species
Emotional Intelligence and Leading a Multigenerational Team
A multi-generational workforce creates diversity in organizations. At present, there are four, and potentially, five generations of employees in the workplace. Various historical and social events have influenced each generation. The distinct life experiences of each generation have shaped workplace values and beliefs which in tum has created tension areas in the workplace. Leaders can tum those challenges into opportunities for the organization by drawing on the concept of emotional intelligence. Leaders with high emotional intelligence skills can regulate and manage their emotion, understand and empathetically relate to the emotion displayed by others, and leverage this skill to understand the generational differences to form an engaged team. The present research posited that a leader\u27s level of emotional intelligence positively impacts job satisfaction along with employee engagement
Conjunto Sounds in a Company Town: Decolonizing Movidas, San Antonio’s Quarrytown, and “La Piedrera” Polka
The persistence, degradation, movement, and absorption of phorate and demeton in clay and soil systems
The purpose of this investigation was to study several factors which influence the fate of phorate and demeton when applied to soil. Radioactive P32-labeled phorate and P32-labeled thiol isomer of demeton were used in leaching and adsorption studies. In the investi-gation on persistence, thin-layer chromatography was employed for pho-rate; and paper chromatography was used for demeton. The degradation was determined by infrared analysis of phorate and phosphorus analysis of demeton. The organic matter content of soils was found to be related to the number of metabolites found over a six-week period and the relative concentration of the metabolites. The half-life of phorate was 62.4 hours at pH 4.5 and 70.0 hours at pH 7.0. The half-life of demeton was determined to be 1,525 hours at both pH 4.5 and 7.0 if calculated for the rate of decomposition for the period of three to seven days. Either a change in order of kinetic decomposition or a catalytic effect resulting from a drop in the pH caused the decomposition rate to increase several fold in seven to fourteen days\u27 treatment time. In movement studies the quantity of phorate remaining in the leaching column was influenced by the moisture condition of the column at the time of application of the insecticide and thereafter before leaching. The dry columns retained more insecticide than did the moist ones. The moisture status of the clay columns had little or no effect on the amount of demeton remaining after leaching. The charge on the phorate molecule was predominantly positive, and the charge on the demeton molecule was predominantly negative. Both insecticides were adsorbed by Southern Bentonite from aqueous suspensions. Tako Kaolin adsorbed both phorate and demeton when calcium saturated. Phorate was adsorbed by Tako Kaolin when aluminum saturated, but deme-ton was repelled. Phosphorus decreased the amount of phorate adsorbed by calcium-saturated Southern Bentonite. Nitrogen and potassium reduced the amount of demeton adsorbed by the same clay. Phorate and demeton were found to expand Southern Bentonite in all cases. The insecticide which caused an expansion above 15.1 and 14.5 angstroms for calcium- and aluminum-saturated clay was very weakly ad-sorbed and could be removed by dialysis
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