57,372 research outputs found
Improved ion exchange membrane
Membrane, made from commercially-available hollow fibers, is used in reverse osmosis, or dialysis. Fiber has skin layers which pass only small molecules. Macromolecules cannot penetrate skin. Fibers can also be used to remove other undesirable anions, such as phosphate, sulfate, carbonate, and uranium in form of uranium-sulfate complex
Ion-exchange hollow fibers
An ion-exchange hollow fiber is prepared by introducing into the wall of the fiber polymerizable liquid monomers, and polymerizing the monomers therein to form solid, insoluble, crosslinked, ion-exchange resin particles which embed in the wall of the fiber. Excess particles blocking the central passage or bore of the fiber are removed by forcing liquid through the fiber. The fibers have high ion-exchange capacity, a practical wall permeability and good mechanical strength even with very thin wall dimensions. Experimental investigation of bundles of ion-exchange hollow fibers attached to a header assembly have shown the fiber to be very efficient in removing counterions from solution
Hybrid LQG-Neural Controller for Inverted Pendulum System
The paper presents a hybrid system controller, incorporating a neural and an
LQG controller. The neural controller has been optimized by genetic algorithms
directly on the inverted pendulum system. The failure free optimization process
stipulated a relatively small region of the asymptotic stability of the neural
controller, which is concentrated around the regulation point. The presented
hybrid controller combines benefits of a genetically optimized neural
controller and an LQG controller in a single system controller. High quality of
the regulation process is achieved through utilization of the neural
controller, while stability of the system during transient processes and a wide
range of operation are assured through application of the LQG controller. The
hybrid controller has been validated by applying it to a simulation model of an
inherently unstable system of inverted pendulum
A psychoanalytic concept illustrated: Will, must, may, can ā revisiting the survival function of primitive omnipotence
The author explores the linear thread connecting the theory of Freud and Klein, in terms of the central significance of the duality of the life and death instinct and the capacity of the ego to tolerate contact with internal and external reality. Theoretical questions raised by later authors, informed by clinical work with children who have suffered deprivation and trauma in infancy, are then considered. Theoretical ideas are illustrated with reference to observational material of a little boy who suffered deprivation and trauma in infancy. He was first observed in the middle of his first year of life while he was living in foster care, and then later at the age of two years and three months, when he had been living with his adoptive parents for more than a year
Radio frequency interference survey over the 1.0-10.4 GHz frequency range at the Goldstone-Venus Development Station
The results of a low sensitivity Radio Frequency Interference (RFI) survey carried out at the Venus Station of the Goldstone Communications Complex are reported. The data cover the spectral range from 1 GHz to 10.4 GHz with a 10-kHz instantaneous bandwidth. Frequency and power levels were observed using a sweep-frequency spectrum analyzer connected to a 1-m diameter antenna pointed at zenith. The survey was conducted from February 16, 1987 through February 24, 1987
Characteristics of Cherenkov Radiation in Naturally Occuring Ice
We revisit the theory of Cherenkov radiation in uniaxial crystals.
Historically, a number of flawed attempts have been made at explaining this
radiation phenomenon and a consistent error-free description is nowhere
available. We apply our calculation to a large modern day telescope - IceCube.
Being located at the Antarctica, this detector makes use of the naturally
occuring ice as a medium to generate Cherenkov radiation. However, due to the
high pressure at the depth of the detector site, large volumes of hexagonal ice
crystals are formed. We calculate how this affects the Cherenkov radiation
yield and angular dependence. We conclude that the effect is small, at most
about a percent, and would only be relevant in future high precision
instruments like e.g. Precision IceCube Next Generation Upgrade (PINGU). For
radio-Cherenkov experiments which use the presence of a clear Cherenkov cone to
determine the arrival direction, any variation in emission angle will directly
and linearly translate into a change in apparent neutrino direction. In
closing, we also describe a simple experiment to test this formalism, and
calculate the impact of anisotropy on light-yields from lead tungstate crystals
as used, for example, in the CMS calorimeter at the CERN LHC
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