Method of Detecting System Function by Measuring Frequency Response

Real time battery impedance spectrum is acquired using one time record, Compensated Synchronous Detection (CSD). This parallel method enables battery diagnostics. The excitation current to a test battery is a sum of equal amplitude sin waves of a few frequencies spread over range of interest. The time profile of this signal has duration that is a few periods of the lowest frequency. The voltage response of the battery, average deleted, is the impedance of the battery in the time domain. Since the excitation frequencies are known, synchronous detection processes the time record and each component, both magnitude and phase, is obtained. For compensation, the components, except the one of interest, are reassembled in the time domain. The resulting signal is subtracted from the original signal and the component of interest is synchronously detected. This process is repeated for each component

Exact Solutions of Exceptional Gauge Theories from Toric Geometry

We derive four dimensional gauge theories with exceptional groups $F_4$, $E_8$, $E_7$, and $E_7$ with matter, by starting from the duality between the heterotic string on $K3$ and F-theory on a elliptically fibered Calabi-Yau 3-fold. This configuration is compactified to four dimensions on a torus, and by employing toric geometry, we compute the type IIB mirrors of the Calabi-Yaus of the type IIA string theory. We identify the Seiberg-Witten curves describing the gauge theories as ALE spaces fibered over a $P^1$ base.Comment: 18 pages, 5 figures, uses harvmac and eps

Cell-Type Specific Changes in Glial Morphology and Glucocorticoid Expression During Stress and Aging in the Medial Prefrontal Cortex.

Repeated exposure to stressors is known to produce large-scale remodeling of neurons within the prefrontal cortex (PFC). Recent work suggests stress-related forms of structural plasticity can interact with aging to drive distinct patterns of pyramidal cell morphological changes. However, little is known about how other cellular components within PFC might be affected by these challenges. Here, we examined the effects of stress exposure and aging on medial prefrontal cortical glial subpopulations. Interestingly, we found no changes in glial morphology with stress exposure but a profound morphological change with aging. Furthermore, we found an upregulation of non-nuclear glucocorticoid receptors (GR) with aging, while nuclear levels remained largely unaffected. Both changes are selective for microglia, with no stress or aging effect found in astrocytes. Lastly, we show that the changes found within microglia inversely correlated with the density of dendritic spines on layer III pyramidal cells. These findings suggest microglia play a selective role in synaptic health within the aging brain

Method of detecting system function by measuring frequency response

Real-time battery impedance spectrum is acquired using a one-time record. Fast Summation Transformation (FST) is a parallel method of acquiring a real-time battery impedance spectrum using a one-time record that enables battery diagnostics. An excitation current to a battery is a sum of equal amplitude sine waves of frequencies that are octave harmonics spread over a range of interest. A sample frequency is also octave and harmonically related to all frequencies in the sum. The time profile of this signal has a duration that is a few periods of the lowest frequency. The voltage response of the battery, average deleted, is the impedance of the battery in the time domain. Since the excitation frequencies are known and octave and harmonically related, a simple algorithm, FST, processes the time record by rectifying relative to the sine and cosine of each frequency. Another algorithm yields real and imaginary components for each frequency

Primary Productivity-Phytoplankton Relationships, Hodgson Lake, Portage County, Ohio

Author Institution: Department of Biological Sciences, Kent State University, Kent, OhioPrimary productivity-phytoplankton relationships were studied for one year (1963-64) in Hodgson Lake, Portage County, Ohio. The lake was found to be a ''blue-greendiatom'' reservoir of moderate productivity, but containing a large phytoplankton standing crop, dominated by the cyanophycean, Oscillatoria rubescens Decandole. Average cell volumes ranged from 1.4 mm3 liter-1 in September to approximately 88.6 mm3liter-1 in June, over 80 percent of which were 0. rubescens. Diatoms, including Cyclotella sp, Fragilaria sp. Asterionella formosa Hass, and Synedra delicatissima W. Sm., usually accounted for <10 percent of the total cell volume. Photosynthesis ranged from 4-5 mgC m-2 day-1 during the winter to approximately 2600-2700 mgC m-2 day-1 in June and October, with an annual mean of 847.5 mgC m~2 day"1. Photosynthesis per unit cell volume ranged from <1ugC day-1 mm-3 during the winter to 172.8 gC day-1 mm-3 in October, averaging 10.5 ugC day-1 mm-3 annually

Two Dimensional Mirror Symmetry From M-theory

We construct two dimensional gauge theories with $N= (4,4)$ supersymmetry from branes of type IIA string theory. Quantum effects in the two dimensional gauge theory are analyzed by embedding the IIA brane construction into M-theory. We find that the Coulomb branch of one theory and the Higgs branch of a mirror theory become equivalent at strong coupling. A relationship to the decoupling limit of the type IIA and IIB 5-branes in Matrix theory is shown. T-duality between the ALE metric and the wormhole metric of Callan, Harvey, and Strominger is discussed from a brane perspective and some puzzles regarding string duality resolved. We comment on the existence of a quantum Higgs branch in two dimensional theories. Branes prove to be useful tools in analyzing singular conformal field theories.Comment: 21 pages, 3 figures, uses harvmac and eps

Observations on CFD Verification and Validation from the AIAA Drag Prediction Workshops

The authors provide observations from the AIAA Drag Prediction Workshops that have spanned over a decade and from a recent validation experiment at NASA Langley. These workshops provide an assessment of the predictive capability of forces and moments, focused on drag, for transonic transports. It is very difficult to manage the consistency of results in a workshop setting to perform verification and validation at the scientific level, but it may be sufficient to assess it at the level of practice. Observations thus far: 1) due to simplifications in the workshop test cases, wind tunnel data are not necessarily the correct results that CFD should match, 2) an average of core CFD data are not necessarily a better estimate of the true solution as it is merely an average of other solutions and has many coupled sources of variation, 3) outlier solutions should be investigated and understood, and 4) the DPW series does not have the systematic build up and definition on both the computational and experimental side that is required for detailed verification and validation. Several observations regarding the importance of the grid, effects of physical modeling, benefits of open forums, and guidance for validation experiments are discussed. The increased variation in results when predicting regions of flow separation and increased variation due to interaction effects, e.g., fuselage and horizontal tail, point out the need for validation data sets for these important flow phenomena. Experiences with a recent validation experiment at NASA Langley are included to provide guidance on validation experiments

Acquiring Impedance Spectra From Diode-Coupled Primary Batteries to Determine Health and State of Charge

The U.S. Army uses BA5590 Lithium Sulfur Dioxide

Regional Distribution of Neurofibrillary Tangles and Senile Plaques in the Cerebral Cortex of Elderly Patients: A Quantitative Evaluation of a One-Year Autopsy Population from a Geriatric Hospital

Detailed analyses of the neuropathologic changes in the cerebral cortex of elderly individuals and Alzheimer's disease patients have demonstrated that certain components of the neocortical and hippocampal circuits are likely to be selectively vulnerable. Based on the distribution of neurofibrillary tangles (NFTs) and senile plaques, it has been proposed that a global cortico-cortical disconnection leads to the loss of integrated functions observed in Alzheimer's disease. In order to investigate the distribution of lesions associated with aging as well as with the earliest symptoms of senile dementia, we performed a quantitative neuropathologic avaluation of a large series of elderly patients representing the entire autopsy population for the year 1989 from a geriatric hospital. Among the 145 cases quantitatively assessed, there were 102 nondemented patients, 33 patients presenting clinically with globally intact intellectual function but early signs of impairment of specific cognitive functions, and 10 cases with senile dementia of the Alzheimer type. All of the cases had NFTs in layer II of the entorhinal cortex, regardless of their clinical diagnosis, and most cases had some NFTs in the CA1 field of the hippocampus. Severe pathologic changes within the inferior temporal neocortex were observed only in the demented cases. The extent of amyloid deposition was not correlated with the clinical diagnosis and seemed to be present in the neocortical areas earlier than in the hippocampal formation. Also, several cases contained NFTs without amyloid deposition, but amyloid never occurred without NFTs. These results suggests that involvement of certain structures within the hippocampal formation is a consistent feature of aging. Thus, involvement of the hippocampal formation may be a necessary, but not sufficient, condition for the clinical expression of dementia, which is likely to be more closely related to the progressive degeneration of select neuronal populations in the neocorte

Method of Detecting System Function by Measuring Frequency Response

Real-time battery impedance spectrum is acquired using a one-time record. Fast Summation Transformation (FST) is a parallel method of acquiring a real-time battery impedance spectrum using a one-time record that enables battery diagnostics. An excitation current to a battery is a sum of equal amplitude sine waves of frequencies that are octave harmonics spread over a range of interest. A sample frequency is also octave and harmonically related to all frequencies in the sum. The time profile of this signal has a duration that is a few periods of the lowest frequency. The voltage response of the battery, average deleted, is the impedance of the battery in the time domain. Since the excitation frequencies are known and octave and harmonically related, a simple algorithm, FST, processes the time record by rectifying relative to the sine and cosine of each frequency. Another algorithm yields real and imaginary components for each frequency