Phase ambiguity resolution for offset QPSK modulation systems

A demodulator for Offset Quaternary Phase Shift Keyed (OQPSK) signals modulated with two words resolves eight possible combinations of phase ambiguity which may produce data error by first processing received I(sub R) and Q(sub R) data in an integrated carrier loop/symbol synchronizer using a digital Costas loop with matched filters for correcting four of eight possible phase lock errors, and then the remaining four using a phase ambiguity resolver which detects the words to not only reverse the received I(sub R) and Q(sub R) data channels, but to also invert (complement) the I(sub R) and/or Q(sub R) data, or to at least complement the I(sub R) and Q(sub R) data for systems using nontransparent codes that do not have rotation direction ambiguity

Searching for Dark Absorption with Direct Detection Experiments

We consider the absorption by bound electrons of dark matter in the form of dark photons and axion-like particles, as well as of dark photons from the Sun, in current and next-generation direct detection experiments. Experiments sensitive to electron recoils can detect such particles with masses between a few eV to more than 10 keV. For dark photon dark matter, we update a previous bound based on XENON10 data and derive new bounds based on data from XENON100 and CDMSlite. We find these experiments to disfavor previously allowed parameter space. Moreover, we derive sensitivity projections for SuperCDMS at SNOLAB for silicon and germanium targets, as well as for various possible experiments with scintillating targets (cesium iodide, sodium iodide, and gallium arsenide). The projected sensitivity can probe large new regions of parameter space. For axion-like particles, the same current direction detection data improves on previously known direct-detection constraints but does not bound new parameter space beyond known stellar cooling bounds. However, projected sensitivities of the upcoming SuperCDMS SNOLAB using germanium can go beyond these and even probe parameter space consistent with possible hints from the white dwarf luminosity function. We find similar results for dark photons from the sun. For all cases, direct-detection experiments can have unprecedented sensitivity to dark-sector particles.Comment: 18 pages, 5 figures, Figs. 3 and 4 fixed, appendices adde

Combustor flame flashback

A stainless steel, two-dimensional (rectangular), center-dump, premixed-prevaporized combustor with quartz window sidewalls for visual access was designed, built, and used to study flashback. A parametric study revealed that the flashback equivalence ratio decreased slightly as the inlet air temperature increased. It also indicated that the average premixer velocity and premixer wall temperature were not governing parameters of flashback. The steady-state velocity balance concept as the flashback mechanism was not supported. From visual observation several stages of burning were identified. High speed photography verified upstream flame propagation with the leading edge of the flame front near the premixer wall. Combustion instabilities (spontaneous pressure oscillations) were discovered during combustion at the dump plane and during flashback. The pressure oscillation frequency ranged from 40 to 80 Hz. The peak-to-peak amplitude (up to 1.4 psi) increased as the fuel/air equivalence ratio was increased attaining a maximum value just before flashback. The amplitude suddenly decreased when the flame stabilized in the premixer. The pressure oscillations were large enough to cause a local flow reversal. A simple test using ceramic fiber tufts indicated flow reversals existed at the premixer exit during flickering. It is suspected that flashback occurs through the premixer wall boundary layer flow reversal caused by combustion instability. A theoretical analysis of periodic flow in the premixing channel has been made. The theory supports the flow reversal mechanism

Infrared radiation measurements of combustion gases Fourth quarterly progress report, Apr. 1 - Jun. 30, 1965

Carbon dioxide fundamental absorption spectrum at 1500 deg Kelvi

Synthesis of GPR119 Interacting Drugs for Treatment of Type II Diabetes

Type II Diabetes is one of the leading causes of death in the United States and is categorized by high blood glucose levels, insulin deficiencies, and inhibition. Located in the pancreas and intestine, the G-Protein Receptor 119 (GPR119) was noted to have an important effect on insulin secretion. Previous studies found that when the receptor is activated, insulin secretion was upregulated which is vital for type II diabetes treatment. Compounds AR437735 and AR437948 are the proposed agonist and inverse agonist pair that will be synthesized and tested for bioactivity to the receptor. It is theorized that the different double-bonded atoms on the two compounds will help determine which ligand on the receptor should be targeted for drug binding to help promote insulin secretion. The synthesis of compounds AR437735 and AR437948 failed, however, a new pair of agonists and inverse agonist were synthesized using the base structure of the two initial compounds. The agonist version of the compound had an overall yield of 18.051%, while its counterpart had an overall yield of 6.259%. All compounds are characterized by Nuclear Magnetic Radiation Spectroscopy (NMR)

SULFATED DEHYDROPOLYMER OF CAFFEIC ACID FOR REPAIR OF LUNG DAMAGE AND EMPHYSEMA

The complex pathobiologic mechanisms of emphysema are not fully understood, leaving this deadly disease without effective pharmacotherapy for a cure. This project hypothesized that the sulfated dehydropolymer of caffeic acid (CDSO3) exhibits Fe2+ chelation-based hypoxia inducible factor-1a (HIF-1a) up-regulatory protective activities against in vitro emphysematous cell death and for in vivo reversal of emphysema induced with SU5416, a vascular endothelial growth factor blocker. Using in vitro chromogenic competitive inhibition assays, CDSO3 was shown to chelate Fe2+ (IC50 of 23 µM), but not Fe3+ ions. The trypan blue exclusion and lactate dehydrogenase assays were then employed to examine the cytoprotective activities of CDSO3 against inflammatory, oxidative, elastolytic, and apoptotic cell death using alveolar macrophages, epithelial and endothelial cells. CDSO3 at 10 µM produced significant protective activities against these emphysematous cell deaths by 50-154 %. These protective effects were opposed by the addition of the HIF-1a inhibitors, CAY10585 and echinomycin, and excess Fe2+, but not Fe3+, ions. Emphysema was then induced in rats following a subcutaneous injection of SU5416 at 20 mg/kg, after which CDSO3 at 60 µg/kg was administered to the lungs 3 times/week for two weeks. Treadmill exercise endurance (EE) was measured to assess the functional impairment, while lung tissues were removed for morphological assessments of alveolar airspace enlargement (MLI) and destruction (DI), as well as to measure protein levels using Western blot. SU5416 significantly impaired EE, MLI, and DI by 81 %, 47 %, and 5-fold, compared to the healthy animals, and these were significantly reversed by CDSO3 by 66, 74, and 87 %. CDSO3 treatment did not change the lung cytoplasmic expression of histone deacetylase 2 (HDAC2), HIF-1a, or a pro-apoptotic marker, BAX. However, induction with SU5416 significantly reduced VEGF expression by 52 % and increased cleaved caspase-3 expression by 1.5-fold, compared to the healthy animals, while CDSO3 normalized the expressions of both proteins in these emphysematous animals. However, when CDSO3 was pre-mixed with excess Fe2+, the reversal activities of CDSO3 were diminished. In conclusion, this study has demonstrated the Fe2+ chelation-based HIF-1a up-regulatory dependent in vitro and in vivo lung repairing efficacies for CDSO3 in emphysema

Infrared radiation measurements of combustion gases third quarterly progress report, 1 jan. - 31 mar. 1965

Infrared absorption spectrum measurements of carbon monoxide - exhaust gase

Transport properties in Simplified Double Exchange model

Transport properties of the manganites by the double-exchange mechanism are considered. The system is modeled by a simplified double-exchange model, i.e. the Hund coupling of the itinerant electron spins and local spins is simplified to the Ising-type one. The transport properties such as the electronic resistivity, the thermal conductivity, and the thermal power are calculated by using Dynamical mean-field theory. The transport quantities obtained qualitatively reproduce the ones observed in the manganites. The results suggest that the Simplified double exchange model underlies the key properties of the manganites.Comment: 5 pages, 5 eps figure