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Tau protein aggregations are a hallmark of amyloid-associated Alzheimer disease and some forms of non-amyloid-associated frontotemporal lobar degeneration. In recent years, several tracers for in vivo tau imaging have been under evaluation. This study investigated the ability of

The high rates of failure in the radiotherapy target volume suggest that patients with stage II or III non-small-cell lung cancer (NSCLC) should receive an increased total dose of radiotherapy. 2-Deoxy-2-[Thirty-four patients with non-resectable lung cancer underwent [The mean pre-RT and per-RT [The correlation between [

The wear and fracture mechanisms of PCD cutters active during the core drilling of reinforced concrete have been documented. All have analogies with well known mechanisms from rotary and rotary-percussive rock drilling and also metal cutting (machining). At rotational velocities up to 5 m/s and normal and cutting forces around 2000 N per 5 mm cutter (equating to principal stresses of around 500 N/mm 2 at the cutting edge), gross fracturing of relatively un-worn cutters early in drilling is the predominant failure mechanism. Chipping at various size scales is observed with approximately the same rate of occurrence as cutter wear, which is mainly caused by attrition abrasion in concrete and to a lesser extent by chemical (diffusive) wear in the reinforcement steel. Chipping occurs by brittle fracture (unstable crack growth) at the small- to mid-scale and by fatigue crack growth at the large scale.

We report on the measurement of the radiation hardness of silicon photomultipliers (SiPMs) manufactured by Fondazione Bruno Kessler in Italy (1 mm$^2$ and 6.2 mm$^2$), Center of Perspective Technology and Apparatus in Russia (1 mm$^2$ and 4.4 mm$^2$), and Hamamatsu Corporation in Japan (1 mm$^2$). The SiPMs were irradiated using a beam of 212 MeV protons at Massachusetts General Hospital, receiving fluences of up to $3 \times 10^{10}$ protons per cm$^2$ with the SiPMs at operating voltage. Leakage currents were read continuously during the irradiation. The delivery of the protons was paused periodically to record scope traces in response to calibrated light pulses to monitor the gains, photon detection efficiencies, and dark counts of the SiPMs. The leakage current and dark noise are found to increase with fluence. Te leakage current is found to be proportional to the mean square deviation of the noise distribution, indicating the dark counts are due to increased random individual pixel activation, while SiPMs remain fully functional as photon detectors. The SiPMs are found to anneal at room temperature with a reduction in the leakage current by a factor of 2 in about 100 days., Comment: 35 pages, 25 figures

Alzheimers disease (AD) is the most common cause of dementia. Although the underlying pathology is still not completely understood, several diagnostic methods are available. Frequently, the most accurate methods are also the most invasive. The present work investigates the diagnostic potential of Pulsed Arterial Spin Labeling (PASL) for AD: a non-invasive, MRI-based technique for the quantification of regional cerebral blood flow (rCBF). In particular, we propose a pilot computer aided diagnostic (CAD) procedure able to discriminate between healthy and diseased subjects, and at the same time, providing visual informative results. This method encompasses the creation of a healthy model, the computation of a voxel-wise likelihood function as comparison between the healthy model and the subject under examination, and the correction of the likelihood function via prior distributions. The discriminant analysis is carried out to maximize the accuracy of the classification. The algorithm has been trained on a dataset of 81 subjects and achieved a sensitivity of 0.750 and a specificity of 0.875. Moreover, in accordance with the current pathological knowledge, the parietal lobe, and limbic system are shown to be the main discriminant factors.

Through an examination of the dynamic nuclear spin polarization and resonant spin-flip Raman scattering, the authors directly measure the optical-induced Overhauser shift in singly charged (In,Ga)As/GaAs quantum dots. Using a two-color laser excitation scheme, they observe the time evolution of the Overhauser shift, which demonstrates the nuclear spin depolarization over a few seconds. Furthermore, it is shown that this depolarization is strongly dependent on temperature.

The use of capillary electrophoresis (CE) for biomedical applications or control of waste water effluents is often restricted, due to the complex matrix embedding trace concentrations of the analyte. Selective removal of interfering ionic species is challenging when analyte and matrix are similar in size and charge. An electrodialysis method applying a home-made module for sample desalting is described. Chloride, sulfate and nitrate ions were employed at 50 or 100 mM (referring to concentrations in real samples from clinical or environmental origin) to simulate matrix compounds. Sulfanilic acid was selected as a model analyte ion at millimolar or sub-millimolar concentrations. Process analysis was performed with ion chromatography coupled on-line. For a simple monitoring of the process in application, conductivity measurement in the sample compartment could be successfully established. Within 45 minutes, the matrix concentration was decreased by a factor of about 10, whilst the analyte was only diluted by a factor of about 3. The rate of the matrix depletion was constant over the whole process and controlled by the constant current generated from the voltage source. Speeding up the process by applying higher current densities failed, due to resulting thermal stress at the membranes. Electrodialysis results were independent of both the matrix anion and matrix cation identity, indicating a good robustness against variations of the sample matrix.

High performance Brillouin spectroscopy (BS) has been used to study the elastic properties (static and dynamic) of the orientational glassy state of Na(CN)xCl1-x samples \(\)). The temperature behaviour of the elastic properties reveals a more complex scenario for the orientational glass transition than generally believed. The shear elastic constant shows the well-known c44(T) anomaly, indicated by a minimum, found in other cyanide mixed crystals. The results obtained for the hypersonic attenuation are in clear contradiction with the dynamic character of the c44(T)-minimum. The temperature behaviour of the longitudinal elastic constant c11 of very dilute \(\)Na(CN)xCl1-x samples shows two striking features: i) Similar to the anomalous temperature behaviour of c44(T), lowering the temperature c11(T) first decreases, goes through a minimum and then rises again. The minimum takes place at a temperature above the temperature, \(\), where c44(T) reaches its minimum value. ii) A kink-like anomaly of c11(T) is observed at lower temperatures. This second anomaly is similar to the classical one observed in canonical glasses at their glass transition temperature \(\).

High-resolution Brillouin spectroscopy has been used as a crucial experimental technique to investigate the nature of the thermal glass transition in an epoxy. In order to study the coupling between the α-relaxation process and the thermal glass transition around the quasi-static glass transition temperature T g we introduce the opto-acoustic dispersion function as a very sensitive measure of the α-relaxations and show that close to but above T g the related relaxation spectrum still contains components within the microwave frequency region which finally is truncated by the thermal glass transition.

Modulated DSC was used to investigate the specific heat around ferroelectric phase transitions. This method has been extended to investigations of slow relaxations within the time domain. For this purpose a suitable cooling assembly is proposed working with liquid nitrogen as well as with liquid helium as a coolant.

Imagined halitosis is poorly documented in the psychiatric literature. It is perhaps best thought of as a symptom rather than as a specific syndrome (a collection of symptoms that co-vary together). Many of the cases with imagined halitosis described in the literature resemble the psychiatric syndrome of social phobia.

Within this work we present Brillouin and ultrasonic investigations performed on the liquid crystals p-methoxybenzylidene p-(n-butylaniline) (MBBA), p-azoxyanisol (PAA), 4-cyano-4-n-alkylbiphenyles (nCB), and 4-n-pentoxybenzylidene-4'-n-octoaniline (5O.8). Special attention has been paid to the evolution of a significant splitting of the two longitudinal polarized acoustic modes within the nematic phase. Angle-resolving Brillouin spectroscopy allowed the determination of the complete stiffness tensors and hence a discussion of the propagation of quasitransverse polarized acoustic modes in the nematic state of liquid crystals. We analyze the behavior of the eigenvectors of the relevant acoustic modes and discuss their significance for the propagation of quasishear modes. For 5O.8 we report an acoustic instability within its nematic state. We confirm the existence of a universal thermal relaxation mechanism of weak activation energy for the nematic state of classical liquid crystals. The observed hypersonic anisotropy is discussed in terms of that relaxation mechanism and is compared with that of glass-forming liquid crystals.

The rotator phase of ${\mathrm{C}}_{24}$${\mathrm{F}}_{50}$ has been characterized in its calorimetric as well as in its elastic properties. To perform the elastic characterization we took advantage of a polytetrafluoroethylene-induced-alignment crystal-growth technique. Special interest is paid to the rotator phase and the premelting behavior therein as reflected by the elastic stiffness coefficients ${\mathit{c}}_{33}$ and ${\mathit{c}}_{44}$. The anomalous elastic behavior is interpreted in the frame of the Landau theory. The premelting process is related to molecular conformational defects.

The room temperature phase of the physical/chemical vapor-deposited statistical co-oligomer VDF/TrFE(70/30) has been characterized by different experimental methods such as small-angle x-ray scattering, wide-angle x-ray diffraction, size-exclusion chromatography, infrared absorption and optical refractometry. The characterization of the elastic properties was carried out using high-performance Brillouin spectroscopy in connection with special scattering geometries. The co-oligomer VDF/TrFE(70/30) was obtained by cracking the parent statistical copolymer and subsequently vapor depositing the shortened chains on highly oriented PTFE substrates (PIA-technique). The room temperature phase of the resulting oriented waxy crystal mats of VDF/TrFE(70/30) is predominantly ferroelectric. The physical properties are very different to those of similarly PIA-prepared n-alkanes, perfluoroalkanes, and blockfluoroalkanes. The microstructure of VDF/TrFE(70/30) is interpreted in terms of partially crystalline nano-sized structures giving rise to a marked freezing process below room temperature. © 1995 John wiley & Sons, Inc.

Objective: To measure comorbidity in patients with oral or oropharyngeal squamous cell carcinoma.Method: Prospective cohort study performed in 2 hospitals in Santos. A total of 116 adult patients treated for a newly diagnosed oral or oropharyngeal squamous cell carcinoma were evaluated on this study from 1996 to 2007. We measured comorbidity illness applying the some validated scales.Results: After 4 years of follow-up the mortality rate was 47.4%. Patients with high values in ACE-27 and WUHNCI showed increased absolute risk of death in 25% and 31%, respectively. Of the 55 deaths in the period, 30.9% were due to other causes than cancer. Four indexes had predictive value on mortality due to other causes than cancer. Thus, patients who have high indexes on CIRS, KFC, ACE-27, and WUHNCI had increased risk of death of 33%, 23%, 44%, and 51%, respectively. Thirty-eight patients (69.1%) presented cancer-related mortality. Only the WUHNCI presented significant difference capable of predicting mortality.Conclusi...

To increase the penetration of renewable energy into grid there has been an increase in interest to explore energy storage technologies and their participation in energy market through demand response. With Vehicle to Grid (V2G) technology, earlier studies have shown that it is more profitable for Electric Vehicles (EV) to participate in regulation market. In this paper, we take a step forward to study the locational impacts that EV might have, on energy, regulation and reserve prices. We model an energy market motivated by Midwest ISO, including post regulation and post reserve transmission constraint to show locational dependent effects of EV on prices.

Frozen-in trans and gauche conformational disorder of symmetrical difluorotetra-chloroethane (DFTCE) produces the tendency of this plastic crystal to form an orientational glassy state on cooling below Tg=86 K. To throw light upon the freezing mechanism in DFTCE neutron diffraction and Brillouin scattering as well as infrared and dielectric measurements are employed. The overall picture of the results obtained can be characterized in terms of a classical glass-transition process with a relaxation frequency obeying the Vogel-Fulcher law. However, a more sophisticated picture of the freezing process is indicated by a quantitative analysis of the new Brillouin data, e.g. the temperature dependence of the sound velocity. The behaviour could be understood on the basis of a mode-coupling theory.

Vehicle to Grid (V2G) technology has opened up a gateway for electric vehicles (EV) to participate in an ISO operated electricity market. To consider the penetration of Electric Vehicles (EV) in the market, there is a need to evaluate their revenue and impact. In this paper, we calculate the revenue that EV might generate, while participating in a regulation market. We base our calculations using a PJM type operated market structure, accounting for energy, reserves, and regulation for all our evaluations.

The close of the 1980s saw many trials and applications of fiber in the loop or FITL. Most delivered traditional telephony (i.e., narrowband) services to the home, but a few provided both narrowband and entertainment video (i.e., broadband) services. During that time, the local-exchange carriers (LECs) also formulated their objectives and strategies for deploying FITL. As they gained a better understanding of the marketplace and the political realities of delivering video services, the LECs adopted an FITL-deployment strategy based on strict cost-effectiveness for the delivery of traditional telephone services. However, any fiber-optic access architecture they adopt has to support broadband services in the future. To address the cost and service challenges of FITL, the LECs and vendors must continually evaluate many alternative access architectures to identify potential advantages that can help fiber access achieve cost parity with copper access. Total system costs must be considered including electrical and optical components, powering system, fiber and cable components, and life-cycle costs (i.e., administration, maintenance, assignment, and provisioning operations).

A typical scintillating tile sampling calorimeter consists of multiple layers of scintillators coupled to wavelength shifting fibers viewed by a suitable photo-detector. Long clear fibers are used to connect the tiles to the readout modules. We have investigated the use of silicon photomultipliers (SiPMs) at the Super Lagre Hadron Collider (SLHC). Because radiation hardness is the main concern, two sets of radiation data were taken using a 212 MeV proton beam at Massachusetts General Hospital. In the first data set we radiated up to a dose of 3×1010 protons per cm2 using diodes from three different manufactures (i.e., FBK, CPTA and Hamamatsu). At a dose of 3x1010 protons per cm2 only small effects of PDE loss were detected due to very high dark count always occupying one or more cells in a multi-cell SiPM. A second set of data up to 1013 protons per cm2 using very high pixel density MAPDs with up to 40,000 cells per mm2. After each small radiation dose multiple scope traces were taken to look at the PDE and dark count of the devices. The increase in dark count due to the radiation was compared to the DC leakage current. Also a comparison was made between multi-cell and single-cell samples of the FBK-IRST diodes.

The elastic and opto-acoustic properties of sodium cyanide crystals NaCN and sodium cyanide--sodium chloride mixed crystals Na(CN${)}_{\mathit{x}}$${\mathrm{Cl}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$ (1\ensuremath{\ge}x\ensuremath{\ge}0.63) were investigated below room temperature using high-resolution Brillouin spectroscopy. Employing special scattering techniques, we were able to measure the elastic behavior in both the high- and low-temperature phases. Changing from systems with high ${\mathrm{CN}}^{\mathrm{\ensuremath{-}}}$ concentrations, which undergo structural phase transitions of first order, to systems with low ${\mathrm{CN}}^{\mathrm{\ensuremath{-}}}$ concentrations, which show glass transitions, the discontinuities of the extremely soft shear stiffness of these cubic crystals gradually vanish. Using a space- and angular-resolving Brillouin technique, we report data on the inhomogeneity of the Czochralski-grown mixed crystals. The consequences of these inhomogeneities for the phase-transition behavior have been studied by thermal analyses. We try to describe our shear elastic stiffness data in the framework of current theoretical approaches.

High peformance Brillouin spectroscopy was applied to study the static and dynamic elastic behaviour of the mixed crystals Na(CN)xCl1−x around the critical concentration (xc%0.63), particularly as a function of temperature. By that means information is obtained about spatial concentration distributions, ferroelastic phases, glass-like phases and hypersonic dynamics.

Brillouin spectroscopy was used to investigate the temperature dependence of the longitudinal acoustic mode, the refractive index, the density and the hypersonic mode Grüneisen parameter around the glass transition of polyvinylacetate. In the glass-transition zone the mode Grüneisen parameter shows an apparent weak anomaly and an extrapolated weak discontinuity of about 60%. The temperature position of this apparent anomaly depends on the thermal history of the sample, whereas the strength of it does not.

As part of the NRC-sponsored program to study the implications of Generic Issue 57, Effects of Fire Protection System Actuation on Safety-Related Equipment,'' a subtask was performed to evaluate the applicability of formal decision analysis methods to generic issues cost/benefit-type decisions and to apply these methods to the GI-57 results. In this report, the numerical results obtained from the analysis of three plants (two PWRs and one BWR) as developed in the technical resolution program for GI-57 were studied. For each plant, these results included a calculation of the person-REM averted due to various accident scenarios and various proposed modifications to mitigate the accident scenarios identified. These results were recomputed to break out the benefit in terms of contributions due to random event scenarios, fire event scenarios, and seismic event scenarios. Furthermore, the benefits associated with risk (in terms of person-REM) averted from earthquakes at three different seismic ground motion levels were separately considered. Given this data, formal decision methodologies involving decision trees, value functions, and utility functions were applied to this basic data. It is shown that the formal decision methodology can be applied at several different levels. Examples are given in which the decision between several retrofits ismore » changed from that resulting from a simple cost/benefit-ratio criterion by virtue of the decision-makinger's expressed (and assumed) preferences.« less

Fiber-in-the-loop(FITL) is currently being deployed to deliver narrowband services such as voice-only telephony.[1] [2] It is essential to demonstrate that this fiber network, which will become the embedded base of the future, can be upgraded to support broadband services. Since these systems often provide bidirectional narrowband service for many users over a single fiber to reduce the cost/user, it may be difficult to provide this broadband upgrade without introducing large system impairments. Here, we demonstrate the upgrade of a fiber used in a current, low-speed FITL system[1] to provide broadband-ISDN service(622 Mb/s outbound and 155.5 Mb/s return) to each of four subscribers. Our system uses a Passive Optical Network(PON),[3] [4] and, because it simultaneously utilizes wavelength-division multiplexing(WDM), time-division multiplexing(TDM), and subcarrier multiplexing(SCM) on a single fiber, it operates with essentially no interchannel interference. We believe this is the first report of this type of multiplexing. In addition, we observe for the first time penalties associated with coherent interference of separate subcarrier lasers.[5]

It is demonstrated that a low capacity fibre-in-loop system can be upgraded to provide broadband ISDN services without modification of the installed transport fibre. A 622Mbit/s outbound and 155.5 Mbit/s return service to each of four customers over a single 9.4 km optical fibre is achieved.

The plane motion of two rigid, straight articulated pipes conveying fluid is examined. In contrast to previous work, the flow rate is not taken as constant, but is allowed to have small periodic oscillations about a mean value, as would be expected in a pump-driven system. It is shown that in the presence of such disturbances, both parametric and combination resonances are possible. When the system can also admit loss of stabilty by static buckling or by flutter, it is found that the presence of small periodic disturbances constitutes a destabilizing effect. Floquet theory and converging infinite determinant expansions are used to illustrate a basic difference between systems which lose stability by divergence and those that lose stability by flutter. An algebraic criterion is obtained for the minimum amplitude of flow rate oscillation required for the system to be affected by the presence of small disturbances.

There has recently been considerable attention given to bidirectional transmission over the same optical fiber. One of the impairments associated with this type of system is receiver sensitivity degradation due to reflected power. This paper presents an analysis of this impairment and compares it with experimental results. It is shown that for a certain class of systems relatively large reflections can be tolerated for a small sacrifice in system range.

The advantages of digital loop carrier systems operating on wire pairs can be enhanced by the use of lightguides in place of wire pairs. Lightwave systems can provide wide bandwidth capability, small cable size, long-range repeater-less operation, and immunity to electromagnetic interferences. This article describes the development of a 1.3-μm LED/PIN based system designed specifically for the loop environment.

A spatial system of two articulated pipes conveying fluid is examined analytically and experimentally. As the flowrate is increased, stable equilibrium is studied for either divergence (static buckling) or by flutter (oscillations with increasing amplitude), depending upon the value of an angle beta which measures the 'out-of-planeness' of the system. It is found that in the range between zero and 90 degrees there exists a transition value of beta below which stability is lost by flutter and above which stability is lost by divergence.

This paper explores the constraints on the design of twowire repeaterless digital subscriber loop (DSL) systems. Broadly categorized, the design depends on the technical feasibility of the approach used to achieve two-wire transmission, constraints related to compatibility with other systems sharing the same cable, and immunity to central office noise. Each of these varies With the choice of system parameters including the transmission rate, transmit power, choice of line codes, etc. Technical feasibility is evaluated by computer simulation studies. Compatibility with other systems is explored by crosstalk calculations. Noise immunity considerations, as they translate into digital line power levels, are also explored.

FRAPCON-2 is a FORTRAN IV computer code that calculates the steady state response of light Mater reactor fuel rods during long-term burnup. The code calculates the temperature, pressure, deformation, and tai lure histories of a fuel rod as functions of time-dependent fuel rod power and coolant boundary conditions. The phenomena modeled by the code include (a) heat conduction through the fuel and cladding, (b) cladding elastic and plastic deformation, (c) fuel-cladding mechanical interaction, (d) fission gas release, (e} fuel rod internal gas pressure, (f) heat transfer between fuel and cladding, (g) cladding oxidation, and (h) heat transfer from cladding to coolant. The code contains necessary material properties, water properties, and heat transfer correlations. FRAPCON-2 is programmed for use on the CDC Cyber 175 and 176 computers. The FRAPCON-2 code Is designed to generate initial conditions for transient fuel rod analysis by either the FRAP-T6 computer code or the thermal-hydraulic code, RELAP4/MOD7 Version 2.