1,595 research outputs found
Balloon-borne package temperature controller
Simple, inexpensive, lightweight enclosure traps upward long wave radiation of earth while reflecting harsh solar radiation in upper atmosphere. It warms enclosed instruments in cold regions and protects them from overheating during the day. Device can be attached to balloon system without any changes in experimental design
Apparatus for controlling the temperature of balloon-borne equipment
A novel apparatus for controlling the temperature of balloon-borne equipment is disclosed, the apparatus serving to utilize the radiant energy emitted by the earth and its atmosphere so as to control the temperature of equipment. The apparatus comprises a housing to be carried aloft by a balloon and defining an enclosure for an instrumentation package. The enclosure includes an upper shield portion as well as a bottom window portion at the base, the bottom window facing the earth below during flight. The upper shield portion is constructed of a material such as aluminized Mylar, which serves to reflect direct sunlight
Triphilic ionic-liquid mixtures: fluorinated and non-fluorinated aprotic ionic-liquid mixtures
We present here the possibility of forming triphilic mixtures from alkyl- and fluoroalkylimidazolium ionic liquids, thus, macroscopically homogeneous mixtures for which instead of the often observed two domainspolar and nonpolarthree stable microphases are present: polar, lipophilic, and fluorous ones. The fluorinated side chains of the cations indeed self-associate and form domains that are segregated from those of the polar and alkyl domains. To enable miscibility, despite the generally preferred macroscopic separation between fluorous and alkyl moieties, the importance of strong hydrogen bonding is shown. As the long-range structure in the alkyl and fluoroalkyl domains is dependent on the composition of the liquid, we propose that the heterogeneous, triphilic structure can be easily tuned by the molar ratio of the components. We believe that further development may allow the design of switchable, smart liquids that change their properties in a predictable way according to their composition or even their environment
Drug user dynamics: a compartmental model of drug users for scenario analyses
A six-typology compartment model of trends in the
use of illicit drugs in Italy is developed to evaluate
policies and interventions through scenario analyses.
Inside the big compartments of just-cannabis users
and multiple drug users, three subpopulations are
taken into account: the occasional, regular and
intensive user. Moreover, compartments for health
care, assisted persons together with a constant
source (susceptible) are added; removed people
(i.e. those who leave drugs for any reason) are put in
a compartment which does not participate in the
dynamics. Flows from the susceptible reservoir
among the drug-user compartments and to the
removed or the health care compartments are
studied in a deterministic linear ODE framework,
where parameters are estimated using Italian data.
This system shows an evolution towards a steady
state, the speed of convergence being dependent on
parameters in a fairly visible way. This model
represents a theoretical development in drug policy
analysis, as it shows the relevance of flux parameters,
which are in principle subject to modifications
due to institutional efforts, together with a quantitative
evaluation of their role in the evolution of the
whole system
An invariant analytic orthonormalization procedure with applications
We apply the orthonormalization procedure previously introduced by two of us
and adopted in connection with coherent states to Gabor frames and other
examples. For instance, for Gabor frames we show how to construct in such a way the functions , and some positive
real number, are mutually orthogonal. We discuss in some details the role of
the lattice naturally associated to the procedure in this analysis
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Adsorption on mixtures of ion exchangers
A theoretical study has been made of adsorption on mixtures of ion exchangers. The effect of variables such as the concentration of the ion being adsorbed, the concentration of the supporting electrolyte, loading, the values of the capacities and equilibrium constants for the various exchange processes, and the fraction of each adsorber in the mixture on the observed distribution coefficient has been investigated. A computer program has been written to facilitate the calculation of distribution coefficients for the adsorption of an ion on a given mixture of ion exchangers under a specified set of conditions
New Insight on Medieval Painting in Sicily: The Virgin Hodegetria Panel in Monreale Cathedral (Palermo, Italy)
: The Virgin Hodegetria, located in the Cathedral of Santa Maria Nuova in Monreale, near
Palermo (Italy), probably dating the first half of the 13th century, is one of the earliest examples
of medieval panel painting in Sicily. A diagnostic campaign was carried out on the panel aiming
to identify the constituting materials and the executive technique, as well as to assess the state of
conservation for supporting the methodological choice of the restoration intervention. Both non invasive (X-ray radiography, digital microscope, multispectral imaging, ED-X-ray fluorescence) and
micro-invasive (polarised light microscopy, ESEM-EDX, ATR-FTIR spectroscopy and micro-Raman
spectroscopy) analyses were performed. According to the results, the executive technique followed
the 13th–14th-century Italian painting tradition. A complex structure was applied on the wooden
support, consisting of a double layer of canvas and several ground layers of gypsum and glue based binder. The underdrawing was made by a brush using carbonaceous black pigment. The
original palette includes red ochre, red lead, azurite, carbon black and bone black. During the several
restorations, mercury-based red, indigo, smalt blue, orpiment and synthetic mars were used. The
original silver leaf of the frame was covered with red tin-based lake and subsequently regilded with
gold leaf. Proteinaceous and oil binders were also detecte
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