120 research outputs found
Thermochemical energy storage for a lunar base
A thermochemical solar energy storage concept involving the reversible reaction CaO + H2O yields Ca(OH)2 is proposed as a power system element for a lunar base. The operation and components of such a system are described. The CaO/H2O system is capable of generating electric power during both the day and night. Mass of the required amount of CaO is neglected since it is obtained from lunar soil. Potential technical problems, such as reactor design and lunar soil processing, are reviewed
Structure and fermentation of natural and manufactured lactose-based oligosaccharides
At early stages of life, infant immature intestine is not fully developed, exposing the new-born to potential diseases. Compounds that can exert beneficial actions on the infant intestine are bioactive lactose-based oligosaccharides (LBOs). The natural source of LBOs is mother milk. When human milk is lacking, dietary supplementation with infant formula fortified with manufactured LBOs, such as galacto-oligosaccharides (GOS), is pursued. GOS have been shown to have several properties in common with HMOs. LBOs composition and intestinal fate is extensively described for humans, whereas they are hardly investigated for domestic animal. In this PhD thesis, composition of LBOs in equine and porcine colostrum were described and new structures were elucidated. The analysis were performed mainly using liquid chromatography and capillary electrophoresis techniques. High inter- and intra-individual variation were found for oligosaccharides present in equine and porcine milk. In vivo fermentation fate of porcine milk oligosaccharides (PMOs) was also described analysing PMOs as found in fecal samples of piglets. The results were correlated to existing literature on HMOs. Dietary oligosaccharides are partially present systemically, as suggested from HMO studies. GOS and PMOs in blood, urine and fecal samples from an in vivo feeding trial on piglet were described. Intact dietary oligosaccharides including GOS and milk oligosaccharides from the piglet diet were found in piglet blood and urine samples. All dietary oligosaccharides were fermented/absorbed in vivo, not being detectable in the piglet fecal samples. On the other hand, GOS in vitro fermentation by piglet inoculum delineate a unique fermentation profile regarding GOS size consumption compared to GOS in vitro fermentation by human fecal inoculum. Similar degradation profile regarding GOS linkage types was observed for GOS fermentation by piglet and human inocula.</p
Титульні сторінки та зміст
Colostrum oligosaccharides are known to exhibit prebiotic and immunomodulatory properties. Oligosaccharide composition is species-specific, and equine colostrum has been reported to contain unique oligosaccharides. Therefore, equine oligosaccharides (EMOS) from colostrum from different horse breeds were analyzed by CE-LIF, CE-MSn, HILIC-MSn, and exoglycosidase degradation. Sixteen EMOS were characterized and quantified, of which half were neutral and half were acidic. EMOS showed about 63% structural overlap with human milk oligosaccharides, known for their bioactivity. Seven EMOS were not reported before in equine oligosaccharides literature: neutral Gal(beta 1-4)HexNAc, Gal(beta 1-4)Hex-Hex, beta 4'-galactosyllactose, and lactose-N- hexaose, as well as acidic 6'-Sialyl-Hex-Ac-HexNAc, sialyllacto-N-tetraose-a, and disialylacto-N-tetraose (isomer not further specified). In all colostrum samples, the average oligosaccharide concentration ranged from 2.12 to 4.63 g/L; with beta 6'and 3'- galactosyllactose, 3'-sialyllactose, and disialyllactose as the most abundant of all oligosaccharides (27-59, 16-37, 1-8, and 1-6%, respectively). Differences in presence and in abundance of specific EMOS were evident not only between the four breeds but also within the breed
Quantum Phonon Optics: Coherent and Squeezed Atomic Displacements
In this paper we investigate coherent and squeezed quantum states of phonons.
The latter allow the possibility of modulating the quantum fluctuations of
atomic displacements below the zero-point quantum noise level of coherent
states. The expectation values and quantum fluctuations of both the atomic
displacement and the lattice amplitude operators are calculated in these
states---in some cases analytically. We also study the possibility of squeezing
quantum noise in the atomic displacement using a polariton-based approach.Comment: 6 pages, RevTe
Recommended from our members
Nondestructive assay of spent boiling water reactor fuel by active neutron interrogation
Spent boiling water reactor (BWR) fuel from Dresden I was assayed for total fissile mass, using the active neutron interrogation method. The nondestructive assay (NDA) system used has four Sb-Be sources for interrogation of the fuels; the induced fission neutrons from the fuel are counted by four lead-shielded methane-filled proportional counters biased above the energy of the source neutrons. Spent fuel rods containing 9 kg of heavy metal were chopped into 5-cm segments and loaded into three 1-liter cans. The three cans were assayed in seven combinations of one, two, or three cans, enabling an evaluation of the precision and accuracy of the NDA system for different amounts of fissile material. The fissile mass in each combination was determined by comparing the induced-fission-neutron counts with the counts obtained from a known standard comprising chopped segments of unirradiated Dresden fuel. These masses were compared to the masses determined by chemical analyses of the spent fuel. The results from the nondestructive assays agreed with results from the chemical analyses to within 2 to 3%. Similar agreement was obtained when two combinations of canned spent fuel were used as standards for the nondesctuctive assays. The assay of BWR spent fuel served as a test of the NDA system which was developed at the Oak Ridge National Laboratory for the assay of spent liquid metal fast breeder reactor (LMFBR) fuel subassemblies at the heat-end of a reprocessing plant. Results of previous experiments and calculations reported earlier using simulated LMFBR fuel subassemblies indicated that the NDA system can measure the fissile masses of spent fuel subassemblies to within an accuracy of 3%. Results of the assays of spent BWR fuel reported herein support this conclusion
CPT and Lorentz Tests in Penning Traps
A theoretical analysis is performed of Penning-trap experiments testing CPT
and Lorentz symmetry through measurements of anomalous magnetic moments and
charge-to-mass ratios. Possible CPT and Lorentz violations arising from
spontaneous symmetry breaking at a fundamental level are treated in the context
of a general extension of the SU(3) x SU(2) x U(1) standard model and its
restriction to quantum electrodynamics. We describe signals that might appear
in principle, introduce suitable figures of merit, and estimate CPT and Lorentz
bounds attainable in present and future Penning-trap experiments. Experiments
measuring anomaly frequencies are found to provide the sharpest tests of CPT
symmetry. Bounds are attainable of approximately in the
electron-positron case and of for a suggested experiment with
protons and antiprotons. Searches for diurnal frequency variations in these
experiments could also limit certain types of Lorentz violation to the level of
in the electron-positron system and others at the level of
in the proton-antiproton system. In contrast, measurements comparing
cyclotron frequencies are sensitive within the present theoretical framework to
different kinds of Lorentz violation that preserve CPT. Constraints could be
obtained on one figure of merit in the electron-positron system at the level of
, on another in the proton-antiproton system at , and on a
third at using comparisons of ions with antiprotons.Comment: 31 pages, published in Physical Review
Ion dynamics in perturbed quadrupole ion traps
Published versio
The deuteron: structure and form factors
A brief review of the history of the discovery of the deuteron in provided.
The current status of both experiment and theory for the elastic electron
scattering is then presented.Comment: 80 pages, 33 figures, submited to Advances in Nuclear Physic
Basic Atomic Physics
Contains reports on four research projects.Joint Services Electronics Program Contract DAAL03-92-C-0001National Science Foundation Grant PHY 89-19381U.S. Navy - Office of Naval Research Grant N00014-90-J-1322National Science Foundation Grant PHY 89-21769U.S. Army - Office of Scientific Research Contract DAAL03-89-K-0082U.S. Navy - Office of Naval Research Grant N00014-89-J-1207U.S. Navy - Office of Naval Research Grant N00014-90-J-164
Basic Atomic Physics
Contains reports on five research projects.National Science Foundation Grant PHY 89-19381National Science Foundation Grant PHY 92-21489U.S. Navy - Office of Naval Research Grant N00014-90-J-1322Joint Services Electronics Program Contract DAAL03-92-C-0001National Science Foundation Grant PHY 89-21769U.S. Army - Office of Scientific Research Grant DAAL03-92-G-0229U.S. Navy - Office of Naval Research Grant N00014-89-J-1207U.S. Navy - Office of Naval Research Grant N00014-90-J-164
- …