An ion beam deceleration lens for ultra-low-energy ion bombardment of naked DNA

Energy Technology Data Exchange (ETDEWEB)

Thopan, P.; Prakrajang, K. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thongkumkoon, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Suwannakachorn, D. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuldyuld@gmail.com [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

2013-07-15

Highlights: ► An ion beam deceleration lens was designed and constructed. ► The deceleration lens was installed and tested. ► The decelerated ion beam energy was measured using an electrical field. ► Decelerated ultra-low-energy ion beam bombarded naked DNA. ► Ion beam with energy of a few tens of eV could break DNA strands. -- Abstract: Study of low-energy ion bombardment effect on biological living materials is of significance. High-energy ion beam irradiation of biological materials such as organs and cells has no doubt biological effects. However, ion energy deposition in the ion-bombarded materials dominantly occurs in the low-energy range. To investigate effects from very-low-energy ion bombardment on biological materials, an ion beam deceleration lens is necessary for uniform ion energy lower than keV. A deceleration lens was designed and constructed based on study of the beam optics using the SIMION program. The lens consisted of six electrodes, able to focus and decelerate primary ion beam, with the last one being a long tube to obtain a parallel uniform exiting beam. The deceleration lens was installed to our 30-kV bioengineering-specialized ion beam line. The final decelerated-ion energy was measured using a simple electrostatic field to bend the beam to range from 10 eV to 1 keV controlled by the lens parameters and the primary beam condition. In a preliminary test, nitrogen ion beam at 60 eV decelerated from a primary 20-keV beam bombarded naked plasmid DNA. The original DNA supercoiled form was found to change to relaxed and linear forms, indicating single or double strand breaks. The study demonstrated that the ion bombardment with energy as low as several-tens eV was possible to break DNA strands and thus potential to cause genetic modification of biological cells.

An ion beam deceleration lens for ultra-low-energy ion bombardment of naked DNA

International Nuclear Information System (INIS)

Thopan, P.; Prakrajang, K.; Thongkumkoon, P.; Suwannakachorn, D.; Yu, L.D.

2013-01-01

Highlights: ► An ion beam deceleration lens was designed and constructed. ► The deceleration lens was installed and tested. ► The decelerated ion beam energy was measured using an electrical field. ► Decelerated ultra-low-energy ion beam bombarded naked DNA. ► Ion beam with energy of a few tens of eV could break DNA strands. -- Abstract: Study of low-energy ion bombardment effect on biological living materials is of significance. High-energy ion beam irradiation of biological materials such as organs and cells has no doubt biological effects. However, ion energy deposition in the ion-bombarded materials dominantly occurs in the low-energy range. To investigate effects from very-low-energy ion bombardment on biological materials, an ion beam deceleration lens is necessary for uniform ion energy lower than keV. A deceleration lens was designed and constructed based on study of the beam optics using the SIMION program. The lens consisted of six electrodes, able to focus and decelerate primary ion beam, with the last one being a long tube to obtain a parallel uniform exiting beam. The deceleration lens was installed to our 30-kV bioengineering-specialized ion beam line. The final decelerated-ion energy was measured using a simple electrostatic field to bend the beam to range from 10 eV to 1 keV controlled by the lens parameters and the primary beam condition. In a preliminary test, nitrogen ion beam at 60 eV decelerated from a primary 20-keV beam bombarded naked plasmid DNA. The original DNA supercoiled form was found to change to relaxed and linear forms, indicating single or double strand breaks. The study demonstrated that the ion bombardment with energy as low as several-tens eV was possible to break DNA strands and thus potential to cause genetic modification of biological cells

Position-Specific Acceleration and Deceleration Profiles in Elite Youth and Senior Soccer Players.

Science.gov (United States)

Vigh-Larsen, Jeppe F; Dalgas, Ulrik; Andersen, Thomas B

2018-04-01

Vigh-Larsen, JF, Dalgas, U, and Andersen, TB. Position-specific acceleration and deceleration profiles in elite youth and senior soccer players. J Strength Cond Res 32(4): 1114-1122, 2018-The purpose of the study was to characterize and compare the position-specific activity profiles of young and senior elite soccer players with special emphasis put on accelerations and decelerations. Eight professional senior matches were tracked using the ZXY tracking system and analyzed for the number of accelerations and decelerations and running distances within different speed zones. Likewise, 4 U19 and 5 U17 matches were analyzed for comparison between youth and senior players. In senior players, the total distance (TD) was 10,776 ± 107 m with 668 ± 28 and 143 ± 10 m being high-intensity running (HIR) and sprinting, respectively. Number of accelerations and decelerations were 81 ± 2 and 84 ± 3, respectively, with central defenders performing the lowest and wide players the highest number. Declines were found between first and second halves for accelerations and decelerations (11 ± 3%), HIR (6 ± 4%), and TD (5 ± 1%), whereas sprinting distance did not differ. U19 players performed a higher number of accelerations, decelerations, and TD compared with senior players. In conclusion, differences in the number and distribution of accelerations and decelerations appeared between player positions, which is of importance when monitoring training and match loads and when prescribing specific training exercises. Furthermore, youth players performed as much high-intensity activities as senior players, indicating that this is not a discriminating physiological parameter between these players.

Earth's Decelerating Tectonic Plates

Energy Technology Data Exchange (ETDEWEB)

Forte, A M; Moucha, R; Rowley, D B; Quere, S; Mitrovica, J X; Simmons, N A; Grand, S P

2008-08-22

Space geodetic and oceanic magnetic anomaly constraints on tectonic plate motions are employed to determine a new global map of present-day rates of change of plate velocities. This map shows that Earth's largest plate, the Pacific, is presently decelerating along with several other plates in the Pacific and Indo-Atlantic hemispheres. These plate decelerations contribute to an overall, globally averaged slowdown in tectonic plate speeds. The map of plate decelerations provides new and unique constraints on the dynamics of time-dependent convection in Earth's mantle. We employ a recently developed convection model constrained by seismic, geodynamic and mineral physics data to show that time-dependent changes in mantle buoyancy forces can explain the deceleration of the major plates in the Pacific and Indo-Atlantic hemispheres.

Preliminary Structural Sensitivity Study of Hypersonic Inflatable Aerodynamic Decelerator Using Probabilistic Methods

Science.gov (United States)

Lyle, Karen H.

2014-01-01

Acceptance of new spacecraft structural architectures and concepts requires validated design methods to minimize the expense involved with technology validation via flighttesting. This paper explores the implementation of probabilistic methods in the sensitivity analysis of the structural response of a Hypersonic Inflatable Aerodynamic Decelerator (HIAD). HIAD architectures are attractive for spacecraft deceleration because they are lightweight, store compactly, and utilize the atmosphere to decelerate a spacecraft during re-entry. However, designers are hesitant to include these inflatable approaches for large payloads or spacecraft because of the lack of flight validation. In the example presented here, the structural parameters of an existing HIAD model have been varied to illustrate the design approach utilizing uncertainty-based methods. Surrogate models have been used to reduce computational expense several orders of magnitude. The suitability of the design is based on assessing variation in the resulting cone angle. The acceptable cone angle variation would rely on the aerodynamic requirements.

Unsteady flow over a decelerating rotating sphere

Science.gov (United States)

Turkyilmazoglu, M.

2018-03-01

Unsteady flow analysis induced by a decelerating rotating sphere is the main concern of this paper. A revolving sphere in a still fluid is supposed to slow down at an angular velocity rate that is inversely proportional to time. The governing partial differential equations of motion are scaled in accordance with the literature, reducing to the well-documented von Kármán equations in the special circumstance near the pole. Both numerical and perturbation approaches are pursued to identify the velocity fields, shear stresses, and suction velocity far above the sphere. It is detected that an induced flow surrounding the sphere acts accordingly to adapt to the motion of the sphere up to some critical unsteadiness parameters at certain latitudes. Afterward, the decay rate of rotation ceases such that the flow at the remaining azimuths starts revolving freely. At a critical unsteadiness parameter corresponding to s = -0.681, the decelerating sphere rotates freely and requires no more torque. At a value of s exactly matching the rotating disk flow at the pole identified in the literature, the entire flow field around the sphere starts revolving faster than the disk itself. Increasing values of -s almost diminish the radial outflow. This results in jet flows in both the latitudinal and meridional directions, concentrated near the wall region. The presented mean flow results will be useful for analyzing the instability features of the flow, whether of a convective or absolute nature.

Acceleration and deceleration capacity of fetal heart rate in an in-vivo sheep model.

Directory of Open Access Journals (Sweden)

Massimo W Rivolta

Full Text Available BACKGROUND: Fetal heart rate (FHR variability is an indirect index of fetal autonomic nervous system (ANS integrity. FHR variability analysis in labor fails to detect early hypoxia and acidemia. Phase-rectified signal averaging (PRSA is a new method of complex biological signals analysis that is more resistant to non-stationarities, signal loss and artifacts. It quantifies the average cardiac acceleration and deceleration (AC/DC capacity. OBJECTIVE: The aims of the study were: (1 to investigate AC/DC in ovine fetuses exposed to acute hypoxic-acidemic insult; (2 to explore the relation between AC/DC and acid-base balance; and (3 to evaluate the influence of FHR decelerations and specific PRSA parameters on AC/DC computation. METHODS: Repetitive umbilical cord occlusions (UCOs were applied in 9 pregnant near-term sheep to obtain three phases of MILD, MODERATE, and SEVERE hypoxic-acidemic insult. Acid-base balance was sampled and fetal ECGs continuously recorded. AC/DC were calculated: (1 for a spectrum of T values (T = 1÷50 beats; the parameter limits the range of oscillations detected by PRSA; (2 on entire series of fetal RR intervals or on "stable" series that excluded FHR decelerations caused by UCOs. RESULTS: AC and DC progressively increased with UCOs phases (MILD vs. MODERATE and MODERATE vs. SEVERE, p<0.05 for DC [Formula: see text] = 2-5, and AC [Formula: see text] = 1-3. The time evolution of AC/DC correlated to acid-base balance (0.4<[Formula: see text]<0.9, p<0.05 with the highest [Formula: see text] for [Formula: see text]. PRSA was not independent from FHR decelerations caused by UCOs. CONCLUSIONS: This is the first in-vivo evaluation of PRSA on FHR analysis. In the presence of acute hypoxic-acidemia we found increasing values of AC/DC suggesting an activation of ANS. This correlation was strongest on time scale dominated by parasympathetic modulations. We identified the best performing [Formula: see text] parameters

Continuous centrifuge decelerator for polar molecules.

Science.gov (United States)

Chervenkov, S; Wu, X; Bayerl, J; Rohlfes, A; Gantner, T; Zeppenfeld, M; Rempe, G

2014-01-10

Producing large samples of slow molecules from thermal-velocity ensembles is a formidable challenge. Here we employ a centrifugal force to produce a continuous molecular beam with a high flux at near-zero velocities. We demonstrate deceleration of three electrically guided molecular species, CH3F, CF3H, and CF3CCH, with input velocities of up to 200  m s(-1) to obtain beams with velocities below 15  m s(-1) and intensities of several 10(9)  mm(-2) s(-1). The centrifuge decelerator is easy to operate and can, in principle, slow down any guidable particle. It has the potential to become a standard technique for continuous deceleration of molecules.

A deceleration system for near-diameter spheres in pipeline transportation in a pebble bed reactor based on the resistance of a pneumatic cushion

International Nuclear Information System (INIS)

Liu, Hongbing; He, Ayada; Du, Dong; Wang, Xin; Zhang, Haiquan

2014-01-01

Highlights: • A deceleration system for fuel transportation in a pebble bed reactor is designed. • Dynamic analysis and motion analysis of the deceleration process are conducted. • The effectiveness of the system is verified by the analysis and the experiment. • Some key design parameters are studied to achieve effective deceleration. • This research provides a guide for the design of a pebble bed reactor. - Abstract: The fuel elements cycle occurring inside and outside the core of a pebble bed reactor is carried out by pneumatic conveying. In some processes of conveyance, it is necessary to reduce the velocity of the moving fuel element in a short time to avoid damage to the fuel elements and the equipment. In this research, a deceleration system for near-diameter spheres in pipeline transportation based on the resistance of a pneumatic cushion is designed to achieve an effective and reliable deceleration process. Dynamic analysis and motion analysis of the deceleration process are conducted. The results show that when the fuel element is moving in the deceleration pipeline, the gas in the pipeline is compressed to create a pneumatic cushion which resists the movement of the fuel element. In this way, the velocity of the fuel element is decreased to below the target value. During this process, the deceleration is steady and reliable. On this basis some key design parameters are studied, such as the deceleration pipeline length, the ratio of the diameter of the fuel element to the internal diameter of the pipeline, etc. The experimental results are generally consistent with the analysis and demonstrate the considerable effectiveness of the deceleration process as well. This research provides a guide for the design of the fuel elements cycling system in a pebble bed reactor along with the optimization of its control

Low Density Supersonic Decelerators

Data.gov (United States)

National Aeronautics and Space Administration — The Low-Density Supersonic Decelerator project will demonstrate the use of inflatable structures and advanced parachutes that operate at supersonic speeds to more...

The Antiproton Accumulator becomes Antiproton Decelerator

CERN Multimedia

1980-01-01

The photos show the Antiproton Accumulator (AA) transformed into Antiproton Decelerator. The AA was used at CERN between 1981 and 1999 before being replaced by the Antiproton Decelerator (AD). The AA was used to collect and stochastically cool antiprotons used in proton-antiproton collisions in the SPS collider. This lead to the discovery of the W and Z bosons in 1983 and the Nobel Prize for Carlo Rubbia and Simon van der Meer in 1984.

Zeeman-Stern Gerlach deceleration of supersonic beams of paramagnetic particles with traveling waves of magnetic field

International Nuclear Information System (INIS)

Trimeche, Azer

2013-01-01

This work focuses on the study and implementation of a new technique of deceleration of a supersonic beam of paramagnetic particles using a co-moving progressive wave of magnetic field. This technique relies on a method of slowing based on Stern-Gerlach forces acting on a paramagnetic system in motion in the presence of a co-propagating magnetic field. This highly innovative approach has the advantage of being applicable to a wide range of species and opens up new opportunities. A suitable theoretical approach is followed, that allows for a direct link between theory, programming of experimental parameters, and experimental results in a systematic, rational and predictive manner. The understanding and control of the dynamics of trapping at a given speed, acceleration and deceleration require decoupling between the transverse and longitudinal effects of the wave. These effects are clearly visible when the added uniform magnetic field limits the transverse effects of the progressive wave of magnetic field. The outlooks for the new Zeeman Stern Gerlach decelerator are numerous. Deceleration paramagnetic molecules, free radicals and neutrons are possible. (author) [fr

Magnetized strange quark matter in f(R, T) gravity with bilinear and special form of time varying deceleration parameter

Science.gov (United States)

Sahoo, P. K.; Sahoo, Parbati; Bishi, Binaya K.; Aygün, Sezgin

2018-04-01

In this paper, we have studied homogeneous and anisotropic locally rotationally symmetric (LRS) Bianchi type-I model with magnetized strange quark matter (MSQM) distribution and cosmological constant Λ in f(R, T) gravity where R is the Ricci scalar and T the trace of matter source. The exact solutions of the field equations are obtained under bilinear and special form of time varying deceleration parameter (DP). Firstly, we have considered two specific forms of bilinear DP with a single parameter of the form: q = α(1-t)/1+t and q = -αt/1+t, which leads to the constant or linear nature of the function based on the constant α. Second one is the special form of the DP as q = - 1 + β/1+aβ. From the results obtained here, one can observe that in the early universe magnetic flux has more effects and it reduces gradually in the later stage. For t → ∞, we get p → -Bc and ρ → Bc. The behaviour of strange quark matter along with magnetic epoch gives an idea of accelerated expansion of the universe as per the observations of the type Ia Supernovae.

Stability of the drive beam in the decelerator of CLIC

CERN Document Server

Schulte, Daniel

2002-01-01

The RF power necessary to accelerate the main beam in the compact linear collider (CLIC) is generated by decelerating high-intensity low energy drive beams in 44 decelerators. Recently new decelerating structures (PETS, power extraction and transfer structures) have been developed. In these structures the RF energy travels with particularly high group velocity, which can affect efficiency and transverse stability. The paper considers the transverse beam stability in the decelerator as well as the longitudinal effects in the presence of dynamic and static imperfections.

Optimal beam sources for Stark decelerators in collision experiments: a tutorial review

International Nuclear Information System (INIS)

Vogels, Sjoerd N.; Gao, Zhi; Meerakker, Sebastiaan Y.T. van de

2015-01-01

With the Stark deceleration technique, packets of molecules with a tunable velocity, a narrow velocity spread, and a high state purity can be produced. These tamed molecular beams find applications in high resolution spectroscopy, cold molecule trapping, and controlled scattering experiments. The quality and purity of the packets of molecules emerging from the decelerator critically depend on the specifications of the decelerator, but also on the characteristics of the molecular beam pulse with which the decelerator is loaded. We consider three frequently used molecular beam sources, and discuss their suitability for molecular beam deceleration experiments, in particular with the application in crossed beam scattering in mind. The performance of two valves in particular, the Nijmegen Pulsed Valve and the Jordan Valve, is illustrated by decelerating ND 3 molecules in a 2.6 meter-long Stark decelerator. We describe a protocol to characterize the valve, and to optimally load the pulse of molecules into the decelerator. We characterize the valves regarding opening time duration, optimal valve-to-skimmer distance, mean velocity, velocity spread, state purity, and relative intensity. (orig.)

Naturalistic rapid deceleration data: Drivers aged 75 years and older

Directory of Open Access Journals (Sweden)

Anna Chevalier

2016-12-01

Full Text Available The data presented in this article are related to the research manuscript “Predictors of older drivers’ involvement in rapid deceleration events”, which investigates potential predictors of older drivers’ involvement in rapid deceleration events including measures of vision, cognitive function and driving confidence (A. Chevalier et al., 2016 [1]. In naturalistic driving studies such as this, when sample size is not large enough to allow crashes to be used to investigate driver safety, rapid deceleration events may be used as a surrogate safety measure. Naturalistic driving data were collected for up to 52 weeks from 182 volunteer drivers aged 75–94 years (median 80 years, 52% male living in the suburban outskirts of Sydney. Driving data were collected using an in-vehicle monitoring device. Accelerometer data were recorded 32 times per second and Global Positioning System (GPS data each second. To measure rapid deceleration behavior, rapid deceleration events (RDEs were defined as having at least one data point at or above the deceleration threshold of 750 milli-g (7.35 m/s2. All events were constrained to a maximum 5 s duration. The dataset provided with this article contains 473 events, with a row per RDE. This article also contains information about data processing, treatment and quality control. The methods and data presented here may assist with planning and analysis of future studies into rapid deceleration behaviour using in-vehicle monitoring.

Rotational speedups accompanying angular deceleration of a superfluid

International Nuclear Information System (INIS)

Campbell, L.J.

1979-01-01

Exact calculations of the angular deceleration of superfluid vortex arrays show momentary speedups in the angular velocity caused by coherent, multiple vortex loss at the boundary. The existence and shape of the speedups depend on the vortex friction, the deceleration rate, and the pattern symmetry. The phenomenon resembles, in several ways, that observed in pulsars

Evaluation of pump characteristic from measurement of fast deceleration

Directory of Open Access Journals (Sweden)

Himr Daniel

2015-01-01

Full Text Available Article describes an experiment where a pump connected to the simple hydraulic circuit is decelerated. Since the deceleration is fast enough the operating point of the machine moves from the initial steady position to the breaking zone, turbine zone and back to the new steady position. A dependence of the specific energy and the torque on the flow rate was evaluated from the measurement of the input and output pressure, torque and rotational speed recorded during the deceleration. Obtained characteristic is much wider than curves obtained from regular measurement of steady state.

Deceleration and Trapping of Heavy Diatomic Molecules for Precision Measurements

Science.gov (United States)

Berg, J. E. Van Den; Turkesteen, S. N. Hoekman; Prinsen, E. B.; Hoekstra, S.

2011-06-01

We are setting up a novel type of Stark-decelerator optimized for the deceleration and trapping of heavy diatomic molecules. Aim of these experiments is to prepare a trapped sample of ultracold molecules for precision studies of fundamental symmetries. The decelerator uses ring-shaped electrodes to create a moving trapping potential, a prototype of which has been shown to work for CO molecules. Molecules can be decelerated and trapped in the weak-field seeking part of excited rotational states. The alkaline-earth monohalide molecules (currently we focus on the SrF molecule) are prime candidates for next generation parity violation and electron-EDM studies. We plan to combine the Stark deceleration with molecular laser cooling to create a trapped sample of molecules at a final temperature of ˜ 200 μK. A. Osterwalder, S. A. Meek, G. Hammer, H. Haak and G. Meijer Phys. Rev. A 81 (51401), 2010. T. A. Isaev, S. Hoekstra, R. Berger Phys. Rev. A 82 (52521), 2010

Echocardiographic parameters and survival in Chagas heart disease with severe systolic dysfunction.

Science.gov (United States)

Rassi, Daniela do Carmo; Vieira, Marcelo Luiz Campos; Arruda, Ana Lúcia Martins; Hotta, Viviane Tiemi; Furtado, Rogério Gomes; Rassi, Danilo Teixeira; Rassi, Salvador

2014-03-01

Echocardiography provides important information on the cardiac evaluation of patients with heart failure. The identification of echocardiographic parameters in severe Chagas heart disease would help implement treatment and assess prognosis. To correlate echocardiographic parameters with the endpoint cardiovascular mortality in patients with ejection fraction Celular em Cardiopatias) - Chagas heart disease arm. The following parameters were collected: left ventricular systolic and diastolic diameters and volumes; ejection fraction; left atrial diameter; left atrial volume; indexed left atrial volume; systolic pulmonary artery pressure; integral of the aortic flow velocity; myocardial performance index; rate of increase of left ventricular pressure; isovolumic relaxation time; E, A, Em, Am and Sm wave velocities; E wave deceleration time; E/A and E/Em ratios; and mitral regurgitation. In the mean 24.18-month follow-up, 27 patients died. The mean ejection fraction was 26.6 ± 5.34%. In the multivariate analysis, the parameters ejection fraction (HR = 1.114; p = 0.3704), indexed left atrial volume (HR = 1.033; p 70.71 mL/m2 were associated with a significant increase in mortality (log rank p < 0.0001). The indexed left atrial volume was the only independent predictor of mortality in this population of Chagasic patients with severe systolic dysfunction.

EARTH’S ROTATIONAL DECELERATION: DETERMINATION OF TIDAL FRICTION INDEPENDENT OF TIMESCALES

International Nuclear Information System (INIS)

Deines, Steven D.; Williams, Carol A.

2016-01-01

This paper determines Earth's rotational deceleration without relying on atomic or ephemeris timescales. Earth's rotation defines the civil time standard called Universal Time (UT). Our previous paper did not examine tidal friction in depth when analyzing the timescale divergence between UT and International Atomic Time (TAI). We examine all available paleontological fossils and deposits for the direct measurements of Earth's past rotation rates, because that record includes all contributing effects. We examine paleontological reports that date Earth's rotation rate using corals, bivalves, brachiopods, rhythmites, and stromatolites. Contributions that vary Earth's moment of inertia, such as continental plate drifts, coastline changes, ice age formations, and viscous glacial rebounds, are superimposed with the secular deceleration. The average deceleration of Earth's rotation rate from all available fossil data is found to be (5.969 ± 1.762) × 10 −7 rad yr −2 . Our value is 99.8% of the total rotational deceleration determined by Christodoulidis et al., who used artificial satellite data, and our value is 96.6% of the expected tidal friction value obtained by Stephenson and Morrison. Taking the derivative of conserved angular momentum, the predicted lunar orbital deceleration caused by the average rotational deceleration corresponds closely to lunar models. When evaluating the significant time gaps between UT and TAI, Earth's rotational deceleration is a minor contributing factor. Also, the secular deceleration rate is necessary to correctly date ancient astronomical events. We strongly encourage that more ocean paleontological evidence be found to supplement the record to separate the many periodic variations embedded in these data

EARTH’S ROTATIONAL DECELERATION: DETERMINATION OF TIDAL FRICTION INDEPENDENT OF TIMESCALES

Energy Technology Data Exchange (ETDEWEB)

Deines, Steven D. [Donatech Corporation, Fairfield, IA 52556 (United States); Williams, Carol A., E-mail: steven.deines@gmail.com, E-mail: cw@math.usf.edu [Department of Mathematics and Statistics (Prof. emeritus), University of South Florida, 4202 E. Fowler Ave., Tampa, FL 33620 (United States)

2016-04-15

This paper determines Earth's rotational deceleration without relying on atomic or ephemeris timescales. Earth's rotation defines the civil time standard called Universal Time (UT). Our previous paper did not examine tidal friction in depth when analyzing the timescale divergence between UT and International Atomic Time (TAI). We examine all available paleontological fossils and deposits for the direct measurements of Earth's past rotation rates, because that record includes all contributing effects. We examine paleontological reports that date Earth's rotation rate using corals, bivalves, brachiopods, rhythmites, and stromatolites. Contributions that vary Earth's moment of inertia, such as continental plate drifts, coastline changes, ice age formations, and viscous glacial rebounds, are superimposed with the secular deceleration. The average deceleration of Earth's rotation rate from all available fossil data is found to be (5.969 ± 1.762) × 10{sup −7} rad yr{sup −2}. Our value is 99.8% of the total rotational deceleration determined by Christodoulidis et al., who used artificial satellite data, and our value is 96.6% of the expected tidal friction value obtained by Stephenson and Morrison. Taking the derivative of conserved angular momentum, the predicted lunar orbital deceleration caused by the average rotational deceleration corresponds closely to lunar models. When evaluating the significant time gaps between UT and TAI, Earth's rotational deceleration is a minor contributing factor. Also, the secular deceleration rate is necessary to correctly date ancient astronomical events. We strongly encourage that more ocean paleontological evidence be found to supplement the record to separate the many periodic variations embedded in these data.

Acceleration (Deceleration Model Supporting Time Delays to Refresh Data

Directory of Open Access Journals (Sweden)

José Gerardo Carrillo González

2018-04-01

Full Text Available This paper proposes a mathematical model to regulate the acceleration (deceleration applied by self-driving vehicles in car-following situations. A virtual environment is designed to test the model in different circumstances: (1 the followers decelerate in time if the leader decelerates, considering a time delay of up to 5 s to refresh data (vehicles position coordinates required by the model, (2 with the intention of optimizing space, the vehicles are grouped in platoons, where 3 s of time delay (to update data is supported if the vehicles have a centre-to-centre spacing of 20 m and a time delay of 1 s is supported at a spacing of 6 m (considering a maximum speed of 20 m/s in both cases, and (3 an algorithm is presented to manage the vehicles’ priority at a traffic intersection, where the model regulates the vehicles’ acceleration (deceleration and a balance in the number of vehicles passing from each side is achieved.

Regulating the infrared by mode matching: a massless scalar in expanding spaces with constant deceleration

NARCIS (Netherlands)

Janssen, T.M.; Prokopec, T.

2011-01-01

In this paper we consider a massless scalar field, with a possible coupling ξ to the Ricci scalar in a D dimensional Friedmann-Lemaître-Robertson-Walker space-time with a constant deceleration parameter q=ϵ-1, ϵ=-H˙/H2. Correlation functions for the Bunch-Davies vacuum of such a theory have long

Experimental study of deceleration process of traveling wave direct energy converter for advanced fusion

International Nuclear Information System (INIS)

Takeno, Hormasa; Yamamoto, Takayoshi; Takada, Kousuke; Yasaka, Yasuyoshi

2007-01-01

Advanced fusion is attractive in the view point of utilization of high efficiency direct energy conversion from fusion produced ions. Deuterium-helium-3 reaction is the most possible, however, the energy of created fast proton is so enormous that conventional electro-static converters cannot be applied. Use of a traveling wave direct energy converter (TWDEC), the principle of which was inverse process of a linear accelerator, was proposed for recovering energy of the fast protons. In order to realize the TWDEC, the authors are continuing experimental study by employing a small-scale simulator. A TWDEC consists of a modulator and a decelerator. Fast proton beam extracted from a reactor is introduced in the modulator where radio frequency (RF) electrostatic field modulate the beam velocity, and hence, the protons are bunched and density-modulated in the downstream. The density-modulated protons flow into the decelerator where a number of electrodes connected to a transmission circuit are axially aligned. The flowing protons induce RF current which creates RF traveling voltage on the electrodes. The RF traveling field between aligned electrodes decelerates the protons, thus their energy is recovered into RF power. In this paper, deceleration process of TWDEC is experimentally examined. In our experimental simulator, because of the small beam current, the induced potential, i.e. the deceleration field is so weak that the beam cannot be decelerated. Thus, we examined the process by dividing into two: one was induction of the deceleration field by the modulated beam, which was called as passive decelerator. The other was energy recovery through interaction between the deceleration field and the modulated beam. In this latter experiment, the deceleration field was supplied externally, and we called this as active decelerator. As for the active decelerator mode, we performed higher beam energy experiment than previous one. As the beam energy increases, the divergence of

Antiproton-decelerating Radio-Frequency Quadrupole (RFQD), inner structure.

CERN Multimedia

Laurent Guiraud

1999-01-01

The inner structure of the RFQD, withdrawn from its tank. In picture _06, the upstream end is in the back and the view is on the downstream exit. The RFQD has a length of 3.5 m and operates at a frequency of 202.4 MHz. It further decelerates antiprotons from the Antiproton Decelerator (3.5 MeV/c to 100 MeV/c, or 5.3 MeV) to very low energies around 50 keV.

A study of the solar wind deceleration in the Earth's foreshock region

Science.gov (United States)

Zhang, T.-L.; Schwingenschuh, K.; Russell, C. T.

1995-01-01

Previous observations have shown that the solar wind is decelerated and deflected in the earth's upstream region populated by long-period waves. This deceleration is corelated with the 'diffuse' but not with the 'reflected' ion population. The speed of the solar wind may decrease tens of km/s in the foreshock region. The solar wind dynamic pressure exerted on the magnetopause may vary due to the fluctuation of the solar wind speed and density in the foreshock region. In this study, we examine this solar wind deceleration and determine how the solar wind deceleration varies in the foreshock region.

Dumping the decelerated beams of CLIC

CERN Document Server

Jeanneret, Bernard

2011-01-01

The spent drive beam must be cleanly extracted and bent away from the decelerator axis at the end of each CLIC decelerator in order to leave space for injecting a fresh beam train in the next sector. Then the spent beam must be safely absorbed. A compact extraction system made of a single dipole is proposed. The spent beam is driven to a water dump located at 20m downstream of the extraction point and transversely 6m away of the axis of the main linac. An adequate spread of the beam impact map on the dump offers small temperature excursions in both the dump and its entrance window, allowing for reliable operation and a long lifetime of the system.

Modified hydraulic braking system limits angular deceleration to safe values

Science.gov (United States)

Briggs, R. S.; Council, M.; Green, P. M.

1966-01-01

Conventional spring actuated, hydraulically released, fail-safe disk braking system is modified to control the angular deceleration of a massive antenna. The hydraulic system provides an immediate preset pressure to the spring-loaded brake shoes and holds it at this value to decelerate the antenna at the desired rate.

Fuel control apparatus of carburetor in deceleration

Energy Technology Data Exchange (ETDEWEB)

Ishii, N

1974-11-20

A fuel control valve for carburetors during deceleration operation is described for fuel conservation. The device cuts off the fuel supply to the cylinder during deceleration. The control valve is regulated by a magnetic switch, and the electrical current to the switch is controlled through a device sensible to the pressure difference to both sides of the throttle valve in the carburetor. When the cylinder becomes lower in pressure than the atmospheric pressure, the pressure activates the electrical current switch, thus activating the magnetic switch to close the fuel control valve. The device also prevents the engine from running after the ignition key is disconnected.

Enhancing trappable antiproton populations through deceleration and frictional cooling

Energy Technology Data Exchange (ETDEWEB)

Zolotorev, M.; Sessler, A.; Penn, G.; Wurtele, J. S.; Charman, A. E.

2012-03-01

CERN currently delivers antiprotons for trapping experiments with the Antiproton Decelerator (AD), which slows the antiprotons down to about 5 MeV.This energy is currently too high for direct trapping, and thick foils are used to slow down the beam to energies which can be trapped.To allow further deceleration to $\\sim 100 \\;\\mbox{keV}$, CERN is initiating the construction of ELENA,consisting of a ring which will combine RF deceleration and electron cooling capabilities. We describe a simple frictionalcooling scheme that can serve to provide significantly improved trapping efficiency, either directly from the AD or first usinga standard deceleration mechanism (induction linac or RFQ). This scheme could be implemented in a short time.The device itself is short in length, uses accessible voltages, and at reasonable cost could serve in the interim beforeELENA becomes operational, or possibly in lieu of ELENA for some experiments. Simple theory and simulations provide a preliminary assessment of theconcept and its strengths and limitations, and highlight important areas for experimental studies, in particular to pin down the level of multiplescattering for low-energy antiprotons. We show that the frictional cooling scheme can provide a similar energy spectrum to that of ELENA,but with higher transverse emittances.

Anomalous deceleration of light ion beam in plasm of inertial confinement fusion

International Nuclear Information System (INIS)

Abe, Takashi; Niu, Keishiro

1981-01-01

The ion beam propagation in inertial confinement fusion by light ion beam is analysed. The anomalous deceleration of the beam ion occurs, when the beam including the electron interacts with the background plasma with a comparable number density. This deceleration is caused by the two stream instability between the beam and the background plasma electrons and then becomes maximum when each density is equivalent. The anomalous deceleration rate of the beam ion is computed by using the quasilinear theory. It is shown that the anomalous deceleration which the beam ion (10 17 cm - 3 ) accepts from the background plasma (10 18 cm - 3 ) is equivalent to the classical one from the background plasma with solid density (10 21 cm - 3 ). (author)

Fluid Volume Expansion and Depletion in Hemodialysis Patients Lack Association with Clinical Parameters

Directory of Open Access Journals (Sweden)

Sylvia Kalainy

2015-12-01

Full Text Available Background: Achievement of normal volume status is crucial in hemodialysis (HD, since both volume expansion and volume contraction have been associated with adverse outcome and events. Objectives: The objectives of this study are to assess the prevalence of fluid volume expansion and depletion and to identify the best clinical parameter or set of parameters that can predict fluid volume expansion in HD patients. Design: This study is cross-sectional. Setting: This study was conducted in three hemodialysis units. Patients: In this study, there are 194 HD patients. Methods: Volume status was assessed by multifrequency bio-impedance spectroscopy (The Body Composition Monitor, Fresenius prior to the mid-week HD session. Results: Of all patients, 48 % ( n = 94 were volume-expanded and 9 % of patients were volume-depleted ( n = 17. Interdialytic weight gain was not different between hypovolemic, normovolemic, and hypervolemic patients. Fifty percent of the volume-expanded patients were hypertensive. Paradoxical hypertension was very common (31 % of all patients; its incidence was not different between patient groups. Intradialytic hypotension was relatively common and was more frequent among hypovolemic patients. Multivariate regression analysis identified only four predictors for volume expansion (edema, lower BMI, higher SBP, and smoking. None of these parameters displayed both a good sensitivity and specificity. Limitations: The volume assessment was performed once. Conclusions: The study indicates that volume expansion is highly prevalent in HD population and could not be identified using clinical parameters alone. No clinical parameters were identified that could reliably predict volume status. This study shows that bio-impedance can assist to determine volume status. Volume status, in turn, is not related to intradialytic weight gain and is unable to explain the high incidence of paradoxical hypertension.

Permanent magnet quadrupoles for the CLIC Drive Beam decelerator

CERN Document Server

Shepherd, Ben; Collomb, Norbert

2012-01-01

STFC in collaboration with CERN has developed a new type of adjustable permanent magnet based quadrupole for the CLIC Drive Beam Decelerator. It uses vertical movement of the permanent magnets to achieve an integrated gradient range of 3.6-14.6T, which will allow it to be used for the first 60% of the decelerator line. Construction of a prototype of this magnet has begun; following this, it will be measured magnetically at CERN and Daresbury Laboratory.

Is the brain's inertia for motor movements different for acceleration and deceleration?

Directory of Open Access Journals (Sweden)

Bhim M Adhikari

Full Text Available The brain's ability to synchronize movements with external cues is used daily, yet neuroscience is far from a full understanding of the brain mechanisms that facilitate and set behavioral limits on these sequential performances. This functional magnetic resonance imaging (fMRI study was designed to help understand the neural basis of behavioral performance differences on a synchronizing movement task during increasing (acceleration and decreasing (deceleration metronome rates. In the MRI scanner, subjects were instructed to tap their right index finger on a response box in synchrony to visual cues presented on a display screen. The tapping rate varied either continuously or in discrete steps ranging from 0.5 Hz to 3 Hz. Subjects were able to synchronize better during continuously accelerating rhythms than in continuously or discretely decelerating rhythms. The fMRI data revealed that the precuneus was activated more during continuous deceleration than during acceleration with the hysteresis effect significant at rhythm rates above 1 Hz. From the behavioral data, two performance measures, tapping rate and synchrony index, were derived to further analyze the relative brain activity during acceleration and deceleration of rhythms. Tapping rate was associated with a greater brain activity during deceleration in the cerebellum, superior temporal gyrus and parahippocampal gyrus. Synchrony index was associated with a greater activity during the continuous acceleration phase than during the continuous deceleration or discrete acceleration phases in a distributed network of regions including the prefrontal cortex and precuneus. These results indicate that the brain's inertia for movement is different for acceleration and deceleration, which may have implications in understanding the origin of our perceptual and behavioral limits.

Echocardiographic Parameters and Survival in Chagas Heart Disease with Severe Systolic Dysfunction

International Nuclear Information System (INIS)

Rassi, Daniela do Carmo; Vieira, Marcelo Luiz Campos; Arruda, Ana Lúcia Martins; Hotta, Viviane Tiemi; Furtado, Rogério Gomes; Rassi, Danilo Teixeira; Rassi, Salvador

2014-01-01

Echocardiography provides important information on the cardiac evaluation of patients with heart failure. The identification of echocardiographic parameters in severe Chagas heart disease would help implement treatment and assess prognosis. To correlate echocardiographic parameters with the endpoint cardiovascular mortality in patients with ejection fraction < 35%. Study with retrospective analysis of pre-specified echocardiographic parameters prospectively collected from 60 patients included in the Multicenter Randomized Trial of Cell Therapy in Patients with Heart Diseases (Estudo Multicêntrico Randomizado de Terapia Celular em Cardiopatias) - Chagas heart disease arm. The following parameters were collected: left ventricular systolic and diastolic diameters and volumes; ejection fraction; left atrial diameter; left atrial volume; indexed left atrial volume; systolic pulmonary artery pressure; integral of the aortic flow velocity; myocardial performance index; rate of increase of left ventricular pressure; isovolumic relaxation time; E, A, Em, Am and Sm wave velocities; E wave deceleration time; E/A and E/Em ratios; and mitral regurgitation. In the mean 24.18-month follow-up, 27 patients died. The mean ejection fraction was 26.6 ± 5.34%. In the multivariate analysis, the parameters ejection fraction (HR = 1.114; p = 0.3704), indexed left atrial volume (HR = 1.033; p < 0.0001) and E/Em ratio (HR = 0.95; p = 0.1261) were excluded. The indexed left atrial volume was an independent predictor in relation to the endpoint, and values > 70.71 mL/m 2 were associated with a significant increase in mortality (log rank p < 0.0001). The indexed left atrial volume was the only independent predictor of mortality in this population of Chagasic patients with severe systolic dysfunction

Echocardiographic Parameters and Survival in Chagas Heart Disease with Severe Systolic Dysfunction

Energy Technology Data Exchange (ETDEWEB)

Rassi, Daniela do Carmo, E-mail: dani.rassi@hotmail.com [Faculdade de Medicina e Hospital das Clínicas da Universidade Federal de Goiás (UFG), Goiânia, GO (Brazil); Vieira, Marcelo Luiz Campos [Instituto do Coração da Faculdade de Medicina da Universidade de São Paulo (USP), São Paulo, SP (Brazil); Arruda, Ana Lúcia Martins [Instituto de Radiologia da Faculdade de Medicina da Universidade de São Paulo (USP), São Paulo, SP (Brazil); Hotta, Viviane Tiemi [Instituto do Coração da Faculdade de Medicina da Universidade de São Paulo (USP), São Paulo, SP (Brazil); Furtado, Rogério Gomes; Rassi, Danilo Teixeira; Rassi, Salvador [Faculdade de Medicina e Hospital das Clínicas da Universidade Federal de Goiás (UFG), Goiânia, GO (Brazil)

2014-03-15

Echocardiography provides important information on the cardiac evaluation of patients with heart failure. The identification of echocardiographic parameters in severe Chagas heart disease would help implement treatment and assess prognosis. To correlate echocardiographic parameters with the endpoint cardiovascular mortality in patients with ejection fraction < 35%. Study with retrospective analysis of pre-specified echocardiographic parameters prospectively collected from 60 patients included in the Multicenter Randomized Trial of Cell Therapy in Patients with Heart Diseases (Estudo Multicêntrico Randomizado de Terapia Celular em Cardiopatias) - Chagas heart disease arm. The following parameters were collected: left ventricular systolic and diastolic diameters and volumes; ejection fraction; left atrial diameter; left atrial volume; indexed left atrial volume; systolic pulmonary artery pressure; integral of the aortic flow velocity; myocardial performance index; rate of increase of left ventricular pressure; isovolumic relaxation time; E, A, Em, Am and Sm wave velocities; E wave deceleration time; E/A and E/Em ratios; and mitral regurgitation. In the mean 24.18-month follow-up, 27 patients died. The mean ejection fraction was 26.6 ± 5.34%. In the multivariate analysis, the parameters ejection fraction (HR = 1.114; p = 0.3704), indexed left atrial volume (HR = 1.033; p < 0.0001) and E/Em ratio (HR = 0.95; p = 0.1261) were excluded. The indexed left atrial volume was an independent predictor in relation to the endpoint, and values > 70.71 mL/m{sup 2} were associated with a significant increase in mortality (log rank p < 0.0001). The indexed left atrial volume was the only independent predictor of mortality in this population of Chagasic patients with severe systolic dysfunction.

X-band rf power production and deceleration in the two-beam test stand of the Compact Linear Collider test facility

Directory of Open Access Journals (Sweden)

E. Adli

2011-08-01

Full Text Available We discuss X-band rf power production and deceleration in the two-beam test stand of the CLIC test facility at CERN. The rf power is extracted from an electron drive beam by a specially designed power extraction structure. In order to test the structures at high-power levels, part of the generated power is recirculated to an input port, thus allowing for increased deceleration and power levels within the structure. The degree of recirculation is controlled by a splitter and phase shifter. We present a model that describes the system and validate it with measurements over a wide range of parameters. Moreover, by correlating rf power measurements with the energy lost by the electron beam, as measured in a spectrometer placed after the power extraction structure, we are able to identify system parameters, including the form factor of the electron beam. The quality of the agreement between model and reality gives us confidence to extrapolate the results found in the present test facility towards the parameter regime of CLIC.

X-band rf power production and deceleration in the two-beam test stand of the Compact Linear Collider test facility

CERN Document Server

Adli, E; Dubrovskiy, A; Syratchev, I; Ruber, R; Ziemann, V

2011-01-01

We discuss X-band rf power production and deceleration in the two-beam test stand of the CLIC test facility at CERN. The rf power is extracted from an electron drive beam by a specially designed power extraction structure. In order to test the structures at high-power levels, part of the generated power is recirculated to an input port, thus allowing for increased deceleration and power levels within the structure. The degree of recirculation is controlled by a splitter and phase shifter. We present a model that describes the system and validate it with measurements over a wide range of parameters. Moreover, by correlating rf power measurements with the energy lost by the electron beam, as measured in a spectrometer placed after the power extraction structure, we are able to identify system parameters, including the form factor of the electron beam. The quality of the agreement between model and reality gives us confidence to extrapolate the results found in the present test facility towards the parameter reg...

Relativistic hydrodynamic simulation of jet deceleration in GRB

International Nuclear Information System (INIS)

Meliani, Z.; Keppens, R.; Casse, F.

2008-01-01

Using the novel adaptive mesh refinement code, AMRVAC, we investigate the interaction between collimated ejecta (jetlike fireball models with various opening angle) with its surrounding cold Interstellar Medium (ISM). This is relevant for Gamma Ray Bursts, and we demonstrate that, thanks to the AMR strategy, we resolve the internal structure of the shocked shell-ISM matter. We determine the deceleration from an initial Lorentz factor γ = 100 up to the almost Newtonian γ∼O(3) phase of the flow. We discuss the effect of varying the opening angle on the deceleration, and pay attention to differences with their 1D isotropic GRB equivalents. These are due to thermally induced sideways expansions of both shocked shell and shocked ISM regions. The propagating 2D ultrarelativistic shell does not accrete all the surrounding medium located within its initial opening angle. The difference with isotropic GRB models is quite pronounced for shells with small opening angle. In the most collimated ejecta (open angle of 1 deg.), the deceleration phase (once the reverse shock has traversed the shell structure) shows distinct modulation, attributed to repeated rarefactions traversing the shell. These may have a clear impact on the emitted afterglow radiation

Hypersonic Inflatable Aerodynamic Decelerator (HIAD) Torus Mechanical Testing

Science.gov (United States)

Chen, Tony; Moholt, Matthew R.; Hudson, Larry D.

2017-01-01

The Armstrong Flight Research Center has performed loads testing of a series of developmental atmospheric entry decelerator structural components. Test setup hardware were designed and fabricated. In addition, test plan and checklist were developed for the consistent and efficient execution of the tests. Eight test articles were successfully tested in over one hundred test runs as test objectives were met. Test article buckling shapes and buckling loads were observed. Displacements and strains were also recorded as various load cases were applied. The test data was sent to Langley Research Center to help with the construction of the finite element model of the decelerator assembly.

Study of Car Acceleration and Deceleration Characteristics at Dangerous Route FT050

Science.gov (United States)

Omar, N.; Prasetijo, J.; Daniel, B. D.; Abdullah, M. A. E.; Ismail, I.

2018-04-01

Individual vehicle acceleration and deceleration are important to generate vehicles speed profile. This study covered acceleration and deceleration characteristics of passenger car in Federal Route FT050 Jalan Batu Pahat-Ayer Hitam that was the top ranking dangerous road. Global Positioning System was used to record 10 cars speed to develop speed profile with clustering zone. At the acceleration manoeuver, the acceleration rate becomes lower as the drivers get near to desired speed. While, at deceleration manoeuver, vehicles with high speed needs more time to stop compare to low speed vehicle. This is because, the drivers need to accelerate more from zero speed to achieve desired speed and drivers need more distance and time to stop their vehicles. However, it was found out that 30% to 50% are driving in dangerous condition that was proven in clustering acceleration and deceleration speed profile. As conclusion, this excessive drivers are the factor that creating high risk in rear-end collision that inline FT050 as dangerous road in Malaysia

[Estimation of volume of pleural fluid and its impact on spirometrical parameters].

Science.gov (United States)

Karwat, Krzysztof; Przybyłowski, Tadeusz; Bielicki, Piotr; Hildebrand, Katarzyna; Nowacka-Mazurek, Magdalena; Nasiłowski, Jacek; Rubinsztajn, Renata; Chazan, Ryszarda

2014-03-01

In the course of various diseases, there is an accumulation of fluid in the pleural cavities. Pleural fluid accumulation causes thoracic volume expansion and reduction of volume lungs, leading to formation of restrictive disorders. The aim of the study was to estimate the volume of pleural fluid by ultrasonography and to search for the relationship between pleural fluid volume and spirometrical parameters. The study involved 46 patients (26 men, 20 women) aged 65.7 +/- 14 years with pleural effusions who underwent thoracentesis. Thoracentesis was preceded by ultrasonography of the pleura, spirometry test and plethysmography. The volume of the pleural fluid was calculated with the Goecke' and Schwerk' (GS) or Padykuła (P) equations. The obtained values were compared with the actual evacuated volume. The median volume of the removed pleural fluid was 950 ml. Both underestimated the evacuated volume (the median volume 539 ml for GS and 648 ml for P, respectively). Pleural fluid removal resulted in a statistically significant improvement in VC (increase 0.20 +/- 0.35 ; p Pleural fluid removal causes a significant improvement in lung function parameters. The analyzed equations for fluid volume calculation do not correlate with the actual volume.

Investigation of the Decelerating Field of an Electron Multiplier under Negative Ion Impact

DEFF Research Database (Denmark)

Larsen, Elfinn; Kjeldgaard, K.

1973-01-01

The effect of the decelerating field of an electron multiplier towards negative ions was investigated under standard mass spectrometric conditions. Diminishing of this decelerating field by changing of the potential of the electron multiplier increased the overall sensitivity to negative ions...

Tragedy and delight: the ethics of decelerated ageing

Science.gov (United States)

Gems, David

2011-01-01

Biogerontology is sometimes viewed as similar to other forms of biomedical research in that it seeks to understand and treat a pathological process. Yet the prospect of treating ageing is extraordinary in terms of the profound changes to the human condition that would result. Recent advances in biogerontology allow a clearer view of the ethical issues and dilemmas that confront humanity with respect to treating ageing. For example, they imply that organismal senescence is a disease process with a broad spectrum of pathological consequences in late life (causing or exascerbating cardiovascular disease, cancer, neurodegenerative disease and many others). Moreover, in laboratory animals, it is possible to decelerate ageing, extend healthy adulthood and reduce the age-incidence of a broad spectrum of ageing-related diseases. This is accompanied by an overall extension of lifespan, sometimes of a large magnitude. Discussions of the ethics of treating ageing sometimes involve hand-wringing about detrimental consequences (e.g. to society) of marked life extension which, arguably, would be a form of enhancement technology. Yet given the great improvements in health that decelerated ageing could provide, it would seem that the only possible ethical course is to pursue it energetically. Thus, decelerated ageing has an element of tragic inevitability: its benefits to health compel us to pursue it, despite the transformation of human society, and even human nature, that this could entail. PMID:21115537

Rayleigh-Taylor instability in the deceleration phase of spherical implosion experiments

International Nuclear Information System (INIS)

Smalyuk, V.A.; Delettrez, J.A.; Goncharov, V.N.; Marshall, F.J.; Meyerhofer, D.D.; Regan, S.P.; Sangster, T.C.; Town, R.P.J.; Yaakobi, B.

2002-01-01

The temporal evolution of inner-shell modulations, unstable during the deceleration phase of a laser-driven spherical implosion, has been measured through K-edge imaging [B. Yaakobi et al., Phys. Plasmas 7, 3727 (2000)] of shells with titanium-doped layers. The main study was based on the implosions of 1 mm diam, 20 μm thick shells filled with either 18 atm or 4 atm of D 3 He gas driven with 23 kJ, 1 ns square laser pulses on OMEGA [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. These targets have similar modulation levels at the beginning of the deceleration phase due to similar modulation growths in the acceleration phase, but different modulation growths throughout the deceleration phase due to different fill pressures (convergence ratios). At peak compression, the measured inner surface, areal-density nonuniformity σ rms levels were 23±5 % for more-stable 18 atm fill targets and 53±11 % for less-stable 4 atm fill targets. The inner-surface modulations grow throughout the deceleration phase due to Rayleigh-Taylor instability and Bell-Plesset convergence effects. The nonuniformity at peak compression is sensitive to the initial perturbation level as measured in implosions with different laser-smoothing conditions

Stochastic Cooling at the CERN Antiproton Decelerator

CERN Document Server

Carli, Christian

2000-01-01

When transforming the CERN Antiproton Collector (AC) into the Antiproton Decelerator (AD), the stochastic cooling systems were rebuilt to cope with the new requirements. Instead of using the original three frequency bands, (0.9-1.6 GHz, 1.6-2.45 GHz and 2.4-3.2 GHz) only the first of these was used due to lattice limitations and other constraints. The same pick-ups and kickers are in use at two different energies. As in the AC, simultaneous cooling in all three phase planes is required. Switching between two transmission paths (at 3.5 GeV/c and 2.0 GeV/c) became necessary, including separate notch filters and delay compensation for the kicker sections. The tanks has to be rendered bakeable (150 C) to make the vacuum properties (<10-10 Torr) compatible with deceleration to low energies. Further improvements included programmable, phase-invariant electronic attenuators and amplitude-invariant delays. Experience during commissioning showed that careful optimization (depth and periodicity) of the notch filters...

Measurement of ultra-low ion energy of decelerated ion beam using a deflecting electric field

Energy Technology Data Exchange (ETDEWEB)

Thopan, P.; Suwannakachorn, D.; Tippawan, U. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@thep-center.org [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

2015-12-15

In investigation on ultra-low-energy ion bombardment effect on DNA, an ion beam deceleration lens was developed for high-quality ultra-low-energy ion beam. Measurement of the ion energy after deceleration was necessary to confirm the ion beam really decelerated as theoretically predicted. In contrast to conventional methods, this work used a simple deflecting electrostatic field after the deceleration lens to bend the ion beam. The beam bending distance depended on the ion energy and was described and simulated. A system for the measurement of the ion beam energy was constructed. It consisted of a pair of parallel electrode plates to generate the deflecting electrical field, a copper rod measurement piece to detect ion beam current, a vernier caliper to mark the beam position, a stepping motor to translate the measurement rod, and a webcam-camera to read the beam bending distance. The entire system was installed after the ion-beam deceleration lens inside the large chamber of the bioengineering vertical ion beam line. Moving the measurement rod across the decelerated ion beam enabled to obtain beam profiles, from which the beam bending distance could be known and the ion beam energy could be calculated. The measurement results were in good agreement with theoretical and simulated results.

Older drivers and rapid deceleration events: Salisbury Eye Evaluation Driving Study.

Science.gov (United States)

Keay, Lisa; Munoz, Beatriz; Duncan, Donald D; Hahn, Daniel; Baldwin, Kevin; Turano, Kathleen A; Munro, Cynthia A; Bandeen-Roche, Karen; West, Sheila K

2013-09-01

Drivers who rapidly change speed while driving may be more at risk for a crash. We sought to determine the relationship of demographic, vision, and cognitive variables with episodes of rapid decelerations during five days of normal driving in a cohort of older drivers. In the Salisbury Eye Evaluation Driving Study, 1425 older drivers aged 67-87 were recruited from the Maryland Motor Vehicle Administration's rolls for licensees in Salisbury, Maryland. Participants had several measures of vision tested: visual acuity, contrast sensitivity, visual fields, and the attentional visual field. Participants were also tested for various domains of cognitive function including executive function, attention, psychomotor speed, and visual search. A custom created driving monitoring system (DMS) was used to capture rapid deceleration events (RDEs), defined as at least 350 milli-g deceleration, during a five day period of monitoring. The rate of RDE per mile driven was modeled using a negative binomial regression model with an offset of the logarithm of the number of miles driven. We found that 30% of older drivers had one or more RDE during a five day period, and of those, about 1/3 had four or more. The rate of RDE per mile driven was highest for those drivers drivingRDE's were more likely to have better scores in cognitive tests of psychomotor speed and visual search, and have faster brake reaction time. Further, greater average speed and maximum speed per driving segment was protective against RDE events. In conclusion, contrary to our hypothesis, older drivers who perform rapid decelerations tend to be more "fit", with better measures of vision and cognition compared to those who do not have events of rapid deceleration. Copyright © 2012 Elsevier Ltd. All rights reserved.

Which echocardiographic parameter is a better marker of volume status in hemodialysis patients?

Science.gov (United States)

Sabaghian, Tahereh; Hajibaratali, Bahareh; Samavat, Shiva

2016-11-01

Bio-impedance analysis (BIA) is a preferred method for estimating the volume status. However, it cannot be utilized in daily practice. Since the assessment of the volume status is important and challenging for hemodialysis (HD) patients, the aim of study was to determine the volume status in chronic HD patients using echocardiographic parameters and assess its correlation with BIA. In this cross-sectional analysis, echocardiography and BIA were performed on 30 chronic HD patients 30 min before and 30 min after dialysis. All the cases of dialysis were performed in the middle of the week. This study also assessed the correlation between echocardiographic parameters and BIA parameters. There were significant differences between ECW, TBW, and TBW% (TBW/W) before and after HD. Significant differences were observed between echocardiographic parameters of IVCD, IVCDi min , IVCDi max before and after the HD. LVEDD, LVESD, LA area, mitral valve inflow, E/E', and IVRT, were improved after dialysis, too. There was a significant correlation between IVCDi min as an index of volume status, ECW% and TBW% before HD and IVCDi min change after dialysis had a significant correlation with %ECW change after dialysis. Comparison between hypertensive and non-hypertensive groups indicated IVCDi min was significantly lower in non-hypertensive group after dialysis. Our results showed a correlation between IVCDi min and BIA parameters before HD. So, it seems that IVCDi min can be a good parameter for determining the volume status of HD patients. However, further studies, with larger sample size and with a prospective study design, are required to confirm these results.

Basic MR sequence parameters systematically bias automated brain volume estimation

International Nuclear Information System (INIS)

Haller, Sven; Falkovskiy, Pavel; Roche, Alexis; Marechal, Benedicte; Meuli, Reto; Thiran, Jean-Philippe; Krueger, Gunnar; Lovblad, Karl-Olof; Kober, Tobias

2016-01-01

Automated brain MRI morphometry, including hippocampal volumetry for Alzheimer disease, is increasingly recognized as a biomarker. Consequently, a rapidly increasing number of software tools have become available. We tested whether modifications of simple MR protocol parameters typically used in clinical routine systematically bias automated brain MRI segmentation results. The study was approved by the local ethical committee and included 20 consecutive patients (13 females, mean age 75.8 ± 13.8 years) undergoing clinical brain MRI at 1.5 T for workup of cognitive decline. We compared three 3D T1 magnetization prepared rapid gradient echo (MPRAGE) sequences with the following parameter settings: ADNI-2 1.2 mm iso-voxel, no image filtering, LOCAL- 1.0 mm iso-voxel no image filtering, LOCAL+ 1.0 mm iso-voxel with image edge enhancement. Brain segmentation was performed by two different and established analysis tools, FreeSurfer and MorphoBox, using standard parameters. Spatial resolution (1.0 versus 1.2 mm iso-voxel) and modification in contrast resulted in relative estimated volume difference of up to 4.28 % (p < 0.001) in cortical gray matter and 4.16 % (p < 0.01) in hippocampus. Image data filtering resulted in estimated volume difference of up to 5.48 % (p < 0.05) in cortical gray matter. A simple change of MR parameters, notably spatial resolution, contrast, and filtering, may systematically bias results of automated brain MRI morphometry of up to 4-5 %. This is in the same range as early disease-related brain volume alterations, for example, in Alzheimer disease. Automated brain segmentation software packages should therefore require strict MR parameter selection or include compensatory algorithms to avoid MR parameter-related bias of brain morphometry results. (orig.)

Basic MR sequence parameters systematically bias automated brain volume estimation

Energy Technology Data Exchange (ETDEWEB)

Haller, Sven [University of Geneva, Faculty of Medicine, Geneva (Switzerland); Affidea Centre de Diagnostique Radiologique de Carouge CDRC, Geneva (Switzerland); Falkovskiy, Pavel; Roche, Alexis; Marechal, Benedicte [Siemens Healthcare HC CEMEA SUI DI BM PI, Advanced Clinical Imaging Technology, Lausanne (Switzerland); University Hospital (CHUV), Department of Radiology, Lausanne (Switzerland); Meuli, Reto [University Hospital (CHUV), Department of Radiology, Lausanne (Switzerland); Thiran, Jean-Philippe [LTS5, Ecole Polytechnique Federale de Lausanne, Lausanne (Switzerland); Krueger, Gunnar [Siemens Medical Solutions USA, Inc., Boston, MA (United States); Lovblad, Karl-Olof [University of Geneva, Faculty of Medicine, Geneva (Switzerland); University Hospitals of Geneva, Geneva (Switzerland); Kober, Tobias [Siemens Healthcare HC CEMEA SUI DI BM PI, Advanced Clinical Imaging Technology, Lausanne (Switzerland); LTS5, Ecole Polytechnique Federale de Lausanne, Lausanne (Switzerland)

2016-11-15

Automated brain MRI morphometry, including hippocampal volumetry for Alzheimer disease, is increasingly recognized as a biomarker. Consequently, a rapidly increasing number of software tools have become available. We tested whether modifications of simple MR protocol parameters typically used in clinical routine systematically bias automated brain MRI segmentation results. The study was approved by the local ethical committee and included 20 consecutive patients (13 females, mean age 75.8 ± 13.8 years) undergoing clinical brain MRI at 1.5 T for workup of cognitive decline. We compared three 3D T1 magnetization prepared rapid gradient echo (MPRAGE) sequences with the following parameter settings: ADNI-2 1.2 mm iso-voxel, no image filtering, LOCAL- 1.0 mm iso-voxel no image filtering, LOCAL+ 1.0 mm iso-voxel with image edge enhancement. Brain segmentation was performed by two different and established analysis tools, FreeSurfer and MorphoBox, using standard parameters. Spatial resolution (1.0 versus 1.2 mm iso-voxel) and modification in contrast resulted in relative estimated volume difference of up to 4.28 % (p < 0.001) in cortical gray matter and 4.16 % (p < 0.01) in hippocampus. Image data filtering resulted in estimated volume difference of up to 5.48 % (p < 0.05) in cortical gray matter. A simple change of MR parameters, notably spatial resolution, contrast, and filtering, may systematically bias results of automated brain MRI morphometry of up to 4-5 %. This is in the same range as early disease-related brain volume alterations, for example, in Alzheimer disease. Automated brain segmentation software packages should therefore require strict MR parameter selection or include compensatory algorithms to avoid MR parameter-related bias of brain morphometry results. (orig.)

Obstetrics at Decisive Crossroads Regarding Pattern-Recognition of Fetal Heart Rate Decelerations: Scientific Principles and Lessons From Memetics.

Science.gov (United States)

Sholapurkar, Shashikant L

2018-04-01

The survival of cardiotocography (CTG) as a tool for intrapartum fetal monitoring seems threatened somewhat unjustifiably and unwittingly despite the absence of better alternatives. Fetal heart rate (FHR) decelerations are center-stage (most important) in the interpretation of CTG with maximum impact on three-tier classification. The pattern-discrimination of FHR decelerations is inexorably linked to their nomenclature. Unscientific or flawed nomenclature of decelerations can explain the dysfunctional CTG interpretation leading to errors in detection of acidemic fetuses. There are three contrasting concepts about categorization of FHR decelerations: 1) all rapid decelerations (the vast majority) should be grouped as "variable" because they are predominantly due to cord-compression, 2) all decelerations are due to chemoreflex from fetal hypoxemia hence their timing is not important, and 3) FHR decelerations should be categorized into "early/late/variable" based primarily on their time relationship to contractions. These theoretical concepts are like memes (ideas/beliefs). Lessons from "memetics" are that the most popular, attractive or established beliefs may not necessarily be true, scientific, beneficial or even without harm. Decelerations coincident with contractions with trough corresponding to the peak of contractions cannot be explained by cord-compression or increasing hypoxia (from compromised uteroplacental perfusion, cord-compression or even cerebral hypoperfusion/anoxia purportedly conceivable from head-compression). Decelerations due to hypoxemia would be associated with delayed recovery of decelerations (lag phase). It is a scientific imperative to cast away disproven/falsified theories. Practices based on unscientific theories lead to patient harm. Clinicians should urgently adopt the categorization of FHR decelerations based primarily of the time relationship to contractions as originally proposed by Hon and Caldeyro-Barcia. This analytical review

Car Deceleration Considering Its Own Velocity in Cellular Automata Model

International Nuclear Information System (INIS)

Li Keping

2006-01-01

In this paper, we propose a new cellular automaton model, which is based on NaSch traffic model. In our method, when a car has a larger velocity, if the gap between the car and its leading car is not enough large, it will decrease. The aim is that the following car has a buffer space to decrease its velocity at the next time, and then avoid to decelerate too high. The simulation results show that using our model, the car deceleration is realistic, and is closer to the field measure than that of NaSch model.

Flexible, Phase Change Fabric for Deployable Decelerators, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — SDMA proposes to develop a flexible fabric containing Phase Change Materials that is suitable for use on Deployable Decelerators. This technology will make...

A scheme for reducing deceleration-phase Rayleigh-Taylor growth in inertial confinement fusion implosions

Science.gov (United States)

Wang, L. F.; Ye, W. H.; Wu, J. F.; Liu, Jie; Zhang, W. Y.; He, X. T.

2016-05-01

It is demonstrated that the growth of acceleration-phase instabilities in inertial confinement fusion implosions can be controlled, especially in the high-foot implosions [O. A. Hurricane et al., Phys. Plasmas 21, 056314 (2014)] on the National Ignition Facility. However, the excessive growth of the deceleration-phase instabilities can still destroy the hot spot ignition. A scheme is proposed to retard the deceleration-phase Rayleigh-Taylor instability growth by shock collision near the waist of the inner shell surface. Two-dimensional radiation hydrodynamic simulations confirm the improved deceleration-phase hot spot stability properties without sacrificing the fuel compression.

A scheme for reducing deceleration-phase Rayleigh–Taylor growth in inertial confinement fusion implosions

Energy Technology Data Exchange (ETDEWEB)

Wang, L. F., E-mail: wang-lifeng@iapcm.ac.cn; Ye, W. H.; Liu, Jie [Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China); HEDPS, Center for Applied Physics and Technology, Peking University, Beijing 100871 (China); Center for Fusion Energy Science and Technology, Chinese Academy of Engineering Physics, Beijing 100088 (China); Wu, J. F. [Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China); Center for Fusion Energy Science and Technology, Chinese Academy of Engineering Physics, Beijing 100088 (China); Zhang, W. Y. [Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China); He, X. T. [Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China); HEDPS, Center for Applied Physics and Technology, Peking University, Beijing 100871 (China)

2016-05-15

It is demonstrated that the growth of acceleration-phase instabilities in inertial confinement fusion implosions can be controlled, especially in the high-foot implosions [O. A. Hurricane et al., Phys. Plasmas 21, 056314 (2014)] on the National Ignition Facility. However, the excessive growth of the deceleration-phase instabilities can still destroy the hot spot ignition. A scheme is proposed to retard the deceleration-phase Rayleigh–Taylor instability growth by shock collision near the waist of the inner shell surface. Two-dimensional radiation hydrodynamic simulations confirm the improved deceleration-phase hot spot stability properties without sacrificing the fuel compression.

Muscle Damage and Metabolic Responses to Repeated-Sprint Running With and Without Deceleration.

Science.gov (United States)

Minahan, Clare L; Poke, Daniel P; Morrison, Jaime; Bellinger, Phillip M

2018-04-04

Minahan, CL, Poke, DP, Morrison, J, and Bellinger, PM. Muscle damage and metabolic responses to repeated-sprint running with and without deceleration. J Strength Cond Res XX(X): 000-000, 2017-This study aimed to determine whether repeated-sprint running with deceleration aggravates markers of muscle damage or delays the recovery of performance compared with repeated-sprint running without deceleration. Fourteen male team-sport athletes performed 2 randomly ordered testing sessions on a nonmotorized treadmill with one session requiring participants to decelerate (TMd) within 4 seconds before stopping or immediately step to the side of the treadmill belt at the completion of each sprint (TMa). Peak and mean velocities, speed decrement, blood lactate concentrations, and oxygen uptake were monitored during the repeated-sprint running protocols. Countermovement vertical jump (CMJ) performance, perceived muscle soreness, sit-and-reach flexibility, plasma creatine kinase (CK), lactate dehydrogenase (LDH), and myoglobin (Mb) concentrations were quantified immediately before and after and 45 minutes, 24 and 48 hours after repeated-sprint running protocols. Although muscle damage was indicated by increases in CK, LDH, and Mb (p ≤ 0.05) in both groups, there was no significant effect of condition (TMa vs. TMd) on any of the measured performance or physiological variables (p > 0.05). The present study indicated that the removal of deceleration from repeated-sprint running on a nonmotorized treadmill has no effect on metabolism or performance during or after repeated-sprint running or markers of muscle damage.

Atmospheric acceleration and Earth-expansion deceleration of the Earth rotation

Directory of Open Access Journals (Sweden)

Wenbin Shen

2017-11-01

Full Text Available Previous studies suggest that tidal friction gives rise to the secular deceleration of the Earth rotation by a quantity of about 2.25 ms/cy. Here we just consider additional contributions to the secular Earth rotation deceleration. Atmospheric solar semi-diurnal tide has a small amplitude and certain amount of phase lead. This periodic global air-mass excess distribution exerts a quasi-constant torque to accelerate the Earth's spin rotation. Using an updated atmospheric tide model, we re-estimate the amounts of this atmospheric acceleration torque and corresponding energy input, of which the associated change rate in LOD (length of day is −0.1 ms/cy. In another aspect, evidences from space-geodesy and sea level rise observations suggest that Earth expands at a rate of 0.35 mm/yr in recent decades, which gives rise to the increase of LOD at rate of 1.0 ms/cy. Hence, if the previous estimate due to the tidal friction is correct, the secular Earth rotation deceleration due to tidal friction and Earth expansion should be 3.15 ms/cy.

Low Density Supersonic Decelerator Flight Dynamics Test-1 Flight Design and Targeting

Science.gov (United States)

Ivanov, Mark

2015-01-01

NASA's Low Density Supersonic Decelerator (LDSD) program was established to identify, develop, and eventually qualify to Test [i.e. Technology] Readiness Level (TRL) - 6 aerodynamic decelerators for eventual use on Mars. Through comprehensive Mars application studies, two distinct Supersonic Inflatable Aerodynamic Decelerator (SIAD) designs were chosen that afforded the optimum balance of benefit, cost, and development risk. In addition, a Supersonic Disk Sail (SSDS) parachute design was chosen that satisfied the same criteria. The final phase of the multi-tiered qualification process involves Earth Supersonic Flight Dynamics Tests (SFDTs) within environmental conditions similar to those that would be experienced during a Mars Entry, Descent, and Landing (EDL) mission. The first of these flight tests (i.e. SFDT-1) was completed on June 28, 2014 with two more tests scheduled for the summer of 2015 and 2016, respectively. The basic flight design for all the SFDT flights is for the SFDT test vehicle to be ferried to a float altitude of 120 kilo-feet by a 34 thousand cubic feet (Mcf) heavy lift helium balloon. Once float altitude is reached, the test vehicle is released from the balloon, spun-up for stability, and accelerated to supersonic speeds using a Star48 solid rocket motor. After burnout of the Star48 motor the vehicle decelerates to pre-flight selected test conditions for the deployment of the SIAD system. After further deceleration with the SIAD deployed, the SSDS parachute is then deployed stressing the performance of the parachute in the wake of the SIAD augmented blunt body. The test vehicle/SIAD/parachute system then descends to splashdown in the Pacific Ocean for eventual recovery. This paper will discuss the development of both the test vehicle and the trajectory sequence including design trade-offs resulting from the interaction of both engineering efforts. In addition, the SFDT-1 nominal trajectory design and associated sensitivities will be discussed

Novel field emission SEM column with beam deceleration technology

International Nuclear Information System (INIS)

Jiruše, Jaroslav; Havelka, Miloslav; Lopour, Filip

2014-01-01

A novel field-emission SEM column has been developed that features Beam Deceleration Mode, high-probe current and ultra-fast scanning. New detection system in the column is introduced to detect true secondary electron signal. The resolution power at low energy was doubled for conventional SEM optics and moderately improved for immersion optics. Application examples at low landing energies include change of contrast, imaging of non-conductive samples and thin layers. - Highlights: • A novel field-emission SEM column has been developed. • Implemented beam deceleration improves the SEM resolution at 1 keV two times. • New column maintains high analytical potential and wide field of view. • Detectors integrated in the column allow gaining true SE and BE signal separately. • Performance of the column is demonstrated on low energy applications

Novel field emission SEM column with beam deceleration technology

Energy Technology Data Exchange (ETDEWEB)

Jiruše, Jaroslav; Havelka, Miloslav; Lopour, Filip

2014-11-15

A novel field-emission SEM column has been developed that features Beam Deceleration Mode, high-probe current and ultra-fast scanning. New detection system in the column is introduced to detect true secondary electron signal. The resolution power at low energy was doubled for conventional SEM optics and moderately improved for immersion optics. Application examples at low landing energies include change of contrast, imaging of non-conductive samples and thin layers. - Highlights: • A novel field-emission SEM column has been developed. • Implemented beam deceleration improves the SEM resolution at 1 keV two times. • New column maintains high analytical potential and wide field of view. • Detectors integrated in the column allow gaining true SE and BE signal separately. • Performance of the column is demonstrated on low energy applications.

Amniotic fluid index predicts the relief of variable decelerations after amnioinfusion bolus.

Science.gov (United States)

Spong, C Y; McKindsey, F; Ross, M G

1996-10-01

Our purpose was to determine whether intrapartum amniotic fluid index before amnioinfusion can be used to predict response to therapeutic amnioinfusion. Intrapartum patients (n = 85) with repetitive variable decelerations in fetal heart rate that necessitated amnioinfusion (10 ml/min for 60 minutes) underwent determination of amniotic fluid index before and after bolus amnioinfusion. The fetal heart tracing was scored (scorer blinded to amniotic fluid index values) for number and characteristics of variable decelerations before and 1 hour after initiation of amnioinfusion. The amnioinfusion was considered successful if it resulted in a decrease of > or = 50% in total number of variable decelerations or a decrease of > or = 50% in the rate of atypical or severe variable decelerations after administration of the bolus. Spontaneous vaginal births before completion of administration of the bolus (n = 18) were excluded from analysis. The probability of success of amnioinfusion in relation to amniotic fluid index was analyzed with the chi(2) test for progressive sequence. The mean amniotic fluid index before amnioinfusion was 6.2 +/- 3.3 cm. An amniotic fluid index of amnioinfusion decreased with increasing amniotic fluid index before amnioinfusion (76% [16/21] when initial amniotic fluid index was 0 to 4 cm, 63% [17/27] when initial amniotic fluid index was 4 to 8 cm, 44% [7/16] when initial amniotic fluid index was 8 to 12 cm, and 33% [1/3] when initial amniotic fluid index was > 12 cm, p = 0.03). The incidence of nuchal cords or true umbilical cord knots increased in relation to amniotic fluid index before amnioinfusion. Amniotic fluid index before amnioinfusion can be used to predict the success of amnioinfusion for relief of variable decelerations in fetal heart rate. Failure of amnioinfusion at a high amniotic fluid index before amnioinfusion may be explained by the increased prevalence of nuchal cords or true knots in the umbilical cord.

Alternating gradient focusing and deceleration of polar molecules

NARCIS (Netherlands)

Bethlem, H.L.; Tarbutt, M.R.; Kupper, J.; Carty, D.; Wohlfart, K.; Hinds, E.A.; Meijer, G.

2006-01-01

Beams of polar molecules can be focused using an array of electrostatic lenses in alternating gradient (AG) configuration. They can also be accelerated or decelerated by applying an appropriate high-voltage switching sequence to the lenses. AG focusing is applicable to molecules in both low-field-

Biases in the perception of self-motion during whole-body acceleration and deceleration

Directory of Open Access Journals (Sweden)

Luc eTremblay

2013-12-01

Full Text Available Several studies have investigated whether vestibular signals can be processed to determine the magnitude of passive body motions. Many of them required subjects to report their perceived displacements offline, i.e. after being submitted to passive displacements. Here, we used a protocol that allowed us to complement these results by asking subjects to report their introspective estimation of their displacement continuously, i.e. during the ongoing body rotation. To this end, participants rotated the handle of a manipulandum around a vertical axis to indicate their perceived change of angular position in space at the same time as they were passively rotated in the dark. The rotation acceleration (Acc and deceleration (Dec lasted either 1.5 s (peak of 60 deg/s2, referred to as being "High" or 3 s (peak of 33 deg/s2, referred to as being "Low". The participants were rotated either counter-clockwise or clockwise, and all combinations of acceleration and deceleration were tested (i.e., AccLow-DecLow; AccLow-DecHigh; AccHigh-DecLow; AccHigh-DecHigh. The participants' perception of body rotation was assessed by computing the gain, i.e. ratio between the amplitude of the perceived rotations (as measured by the rotating manipulandum’s handle and the amplitude of the actual chair rotations. The gain was measured at the end of the rotations, and was also computed separately for the acceleration and deceleration phases. Three salient findings resulted from this experiment: i the gain was much greater during body acceleration than during body deceleration, ii the gain was greater during High compared to Low accelerations and iii the gain measured during the deceleration was influenced by the preceding acceleration (i.e., Low or High. These different effects of the angular stimuli on the perception of body motion can be interpreted in relation to the consequences of body acceleration and deceleration on the vestibular system and on higher-order cognitive

Simultaneous, Unsteady PIV and Photogrammetry Measurements of a Tension-Cone Decelerator in Subsonic Flow

Science.gov (United States)

Schairer, Edward T.; Heineck, James T.; Walker, Louise Ann; Kushner, Laura Kathryn; Zilliac, Gregory

2010-01-01

This paper describes simultaneous, synchronized, high-frequency measurements of both unsteady flow in the wake of a tension-cone decelerator in subsonic flow (by PIV) and the unsteady shape of the decelerator (by photogrammetry). The purpose of these measurements was to develop the test techniques necessary to validate numerical methods for computing fluid-structure interactions of flexible decelerators. A critical need for this effort is to map fabric surfaces that have buckled or wrinkled so that code developers can accurately represent them. This paper describes a new photogrammetric technique that performs this measurement. The work was done in support of the Entry, Descent, and Landing discipline within the Supersonics Project of NASA s Fundamental Aeronautics Program.

Unified Brake Service by a Hierarchical Controller for Active Deceleration Control in an Electric and Automated Vehicle

Directory of Open Access Journals (Sweden)

Yuliang Nie

2017-12-01

Full Text Available Unified brake service is a universal service for generating certain brake force to meet the demand deceleration and is essential for an automated driving system. However, it is rather difficult to control the pressure in the wheel cylinders to reach the target deceleration of the automated vehicle, which is the key issue of the active deceleration control system (ADC. This paper proposes a hierarchical control method to actively control vehicle deceleration with active-brake actuators. In the upper hierarchical, the target pressure of wheel cylinders is obtained by dynamic equations of a pure electric vehicle. In the lower hierarchical, the solenoid valve instructions and the pump speed of hydraulic control unit (HCU are determined to satisfy the desired pressure with the feedback of measured wheel cylinder pressure by pressure sensors. Results of road experiments of a pure electric and automated vehicle indicate that the proposed method realizes the target deceleration accurately and efficiently.

The radiative deceleration of ultrarelativistic jets in active galactic nuclei

International Nuclear Information System (INIS)

Melia, F.; Konigl, A.

1989-01-01

A detailed study of the dynamical interaction between a highly relativistic jet and the thermal radiation field from an AGN accretion disk is reported, and the Comptonized spectrum arising from this interaction is self-consistently determined. A simple model that captures the essential radiative and geometrical features of realistic disk configurations is presented, and the disk radiation field is calculated. The results confirm Phinney's (1987) suggestion that the thermal radiation field produced by accretion in an AGN could be very effective in decelerating ultrarelativistic jets that are accreted by electromagnetic or hydromagnetic forces closer to the central black hole. Terminal Lorentz factors are consistent with the values inferred in superluminal radio sources are readily produced in this model for plausible disk and jet parameters without additional acceleration in the interaction zone. A new interpretation of the hard X-ray component detected in BL Lac spectra is proposed. 55 refs

Inflatable Aerocapture Decelerators with Shape Morphing Trajectory Control, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The proposed research is focused on developing an aerocapture decelerator that is substantially lighter than other approaches by using lightweight, fiber-reinforced...

LLE Review Quarterly Report (October-December 2000). Volume 85

Energy Technology Data Exchange (ETDEWEB)

Sources, John M. [Univ. of Rochester, NY (United States). Lab. for Laser Energetics

2000-12-01

This volume of the LLE Review, covering October-December 2000, begins with an article by R. Betti, M. Umansky, V. Lobatchev, V. N. Goncharov, and R. L. McCrory, who report on the development of a model for the deceleration phase of an imploding inertial fusion capsule (p. 1). The model shows that the ablative flow off the inner shell surface plays a critical role in reducing the growth rate and suppressing short-wavelength modes in the deceleration-phase Rayleigh-Taylor instability. Other articles in this volume are: The Effect of Shock Heating on the Stability of Laser-Driven Targets; Spherical Cavity Expansion in Material with Densification; Design and Performance of a Selectable-Rate Streak-Camera Deflection Ramp Generator; Unique High-Bandwidth, UV Fiber Deliver System for OMEGA Diagnostics Applications; Fabrication and Properties of an Ultrafast NbN Hot-Electron Single-Photon detector; and, Preliminary Design of NIF 2-D SSD.

Development and Testing of a New Family of Supersonic Decelerators

Science.gov (United States)

Clark, Ian G.; Adler, Mark; Rivellini, Tommaso P.

2013-01-01

The state of the art in Entry, Descent, and Landing systems for Mars applications is largely based on technologies developed in the late 1960's and early 1970's for the Viking Lander program. Although the 2011 Mars Science Laboratory has made advances in EDL technology, these are predominantly in the areas of entry (new thermal protection systems and guided hypersonic flight) and landing (the sky crane architecture). Increases in entry mass, landed mass, and landed altitude beyond MSL capabilities will require advances predominantly in the field of supersonic decelerators. With this in mind, a multi-year program has been initiated to advance three new types of supersonic decelerators that would enable future large-robotic and human-precursor class missions to Mars.

Rapid Deceleration-Driven Wetting Transition during Pendant Drop Deposition on Superhydrophobic Surfaces

Science.gov (United States)

Kwon, Hyuk-Min; Paxson, Adam T.; Varanasi, Kripa K.; Patankar, Neelesh A.

2011-01-01

A hitherto unknown mechanism for wetting transition is reported. When a pendant drop settles upon deposition, there is a virtual “collision” where its center of gravity undergoes rapid deceleration. This induces a high water hammer-type pressure that causes wetting transition. A new phase diagram shows that both large and small droplets can transition to wetted states due to the new deceleration driven and the previously known Laplace mechanisms, respectively. It is explained how the attainment of a nonwetted Cassie-Baxter state is more restrictive than previously known.

Designing cylindrical implosion experiments on NIF to study deceleration phase of Rayleigh-Taylor

Science.gov (United States)

Vazirani, N.; Kline, J. L.; Loomis, E.; Sauppe, J. P.; Palaniyappan, S.; Flippo, K.; Srinivasan, B.; Malka, E.; Bose, A.; Shvarts, D.

2017-10-01

The Rayleigh-Taylor (RT) hydrodynamic instability occurs when a lower density fluid pushes on a higher density fluid. This occurs in inertial confinement fusion (ICF) implosions at each of the capsule interfaces during the initial acceleration and the deceleration as it stagnates. The RT instabilities mix capsule material into the fusion fuel degrading the Deuterium-Tritium reactivity and ultimately play a key role in limiting target performance. While significant effort has focused on understanding RT at the outer capsule surface, little work has gone into understanding the inner surface RT instability growth during the deceleration phase. Direct measurements of the RT instability are difficult to make at high convergence in a spherical implosion. Here we present the design of a cylindrical implosion system for the National Ignition Facility for studying deceleration phase RT. We will discuss the experimental design, the estimated instability growth, and our outstanding concerns.

Comparison of Analysis with Test for Static Loading of Two Hypersonic Inflatable Aerodynamic Decelerator Concepts

Science.gov (United States)

Lyle, Karen H.

2015-01-01

Acceptance of new spacecraft structural architectures and concepts requires validated design methods to minimize the expense involved with technology demonstration via flight-testing. Hypersonic Inflatable Aerodynamic Decelerator (HIAD) architectures are attractive for spacecraft deceleration because they are lightweight, store compactly, and utilize the atmosphere to decelerate a spacecraft during entry. However, designers are hesitant to include these inflatable approaches for large payloads or spacecraft because of the lack of flight validation. This publication summarizes results comparing analytical results with test data for two concepts subjected to representative entry, static loading. The level of agreement and ability to predict the load distribution is considered sufficient to enable analytical predictions to be used in the design process.

Flow Studies of Decelerators at Supersonic Speeds

Science.gov (United States)

1959-01-01

Wind tunnel tests recorded the effect of decelerators on flow at various supersonic speeds. Rigid parachute models were tested for the effects of porosity, shroud length, and number of shrouds. Flexible model parachutes were tested for effects of porosity and conical-shaped canopy. Ribbon dive brakes on a missile-shaped body were tested for effect of tension cable type and ribbon flare type. The final test involved a plastic sphere on riser lines.

Studies on atom deceleration process by using the Zeeman-tuned technique

International Nuclear Information System (INIS)

Bagnato, V.S.

1990-01-01

The Zeeman-tuned technique to slow an atomic beam of sodium atoms was detailed studied. A new technique to study the deceleration which consists in monitoring the fluorescence along the deceleration path is used. This allows a direct observation of the process and open possibilities to investigate the adiabatic following of atoms in the magnetic field, and others very important aspects of the process. With a single laser and some modification of the magnetic field profile it is possible stop atoms outside the slower solenoid, which make a lot of experiments much simpler. A systematic study of the optical pumping effects and adiabatic following conditions allow to produce a very strong slow motion atomic beam. (author)

Subclinical decelerations during developing hypotension in preterm fetal sheep after acute on chronic lipopolysaccharide exposure

Science.gov (United States)

Lear, Christopher A.; Davidson, Joanne O.; Galinsky, Robert; Yuill, Caroline A.; Wassink, Guido; Booth, Lindsea C.; Drury, Paul P.; Bennet, Laura; Gunn, Alistair J.

2015-01-01

Subclinical (shallow) heart rate decelerations occur during neonatal sepsis, but there is limited information on their relationship with hypotension or whether they occur before birth. We examined whether subclinical decelerations, a fall in fetal heart rate (FHR) that remained above 100 bpm, were associated with hypotension in preterm fetal sheep exposed to lipopolysaccharide (LPS). Chronically-instrumented fetal sheep at 0.7 gestation received continuous low-dose LPS infusions (n = 15, 100 ng/kg over 24 h, followed by 250 ng/kg/24 h for 96 h) or saline (n = 8). Boluses of 1 μg LPS or saline were given at 48 and 72 h. FHR variability (FHRV) was calculated, and sample asymmetry was used to assess the severity and frequency of decelerations. Low-dose LPS infusion did not affect FHR. After the first LPS bolus, 7 fetuses remained normotensive, while 8 developed hypotension (a fall in mean arterial blood pressure of ≥5 mmHg). Developing hypotension was associated with subclinical decelerations, with a corresponding increase in sample asymmetry and FHRV (p < 0.05). The second LPS bolus was associated with similar but attenuated changes in FHR and blood pressure (p < 0.05). In conclusion, subclinical decelerations are not consistently seen during prenatal exposure to LPS, but may be a useful marker of developing inflammation-related hypotension before birth. PMID:26537688

Periodic components of hand acceleration/deceleration impulses during telemanipulation

Energy Technology Data Exchange (ETDEWEB)

Draper, J.V. [Oak Ridge National Lab., TN (United States); Handel, S. [Tennessee Univ., Knoxville, TN (United States). Dept. of Psychology

1994-01-01

Responsiveness is the ability of a telemanipulator to recreate user trajectories and impedance in time and space. For trajectory production, a key determinant of responsiveness is the ability of the system to accept user inputs, which are forces on the master handle generated by user hand acceleration/deceleration (a/d) impulses, and translate them into slave arm acceleration/deceleration. This paper presents observations of master controller a/d impulses during completion of a simple target acquisition task. Power spectral density functions (PSDF`s) calculated from hand controller a/d impulses were used to assess impulse waveform. The relative contributions of frequency intervals ranging up to 25 Hz for three spatially different versions of the task were used to determine which frequencies were most important. The highest relative power was observed in frequencies between 1 Hz and 6 Hz. The key frequencies related to task difficulty were in the range from 2 Hz to 8 Hz. the results provide clues to the source of the performance inhibition.

Periodic components of hand acceleration/deceleration impulses during telemanipulation

International Nuclear Information System (INIS)

Draper, J.V.; Handel, S.

1994-01-01

Responsiveness is the ability of a telemanipulator to recreate user trajectories and impedance in time and space. For trajectory production, a key determinant of responsiveness is the ability of the system to accept user inputs, which are forces on the master handle generated by user hand acceleration/deceleration (a/d) impulses, and translate them into slave arm acceleration/deceleration. This paper presents observations of master controller a/d impulses during completion of a simple target acquisition task. Power spectral density functions (PSDF's) calculated from hand controller a/d impulses were used to assess impulse waveform. The relative contributions of frequency intervals ranging up to 25 Hz for three spatially different versions of the task were used to determine which frequencies were most important. The highest relative power was observed in frequencies between 1 Hz and 6 Hz. The key frequencies related to task difficulty were in the range from 2 Hz to 8 Hz. the results provide clues to the source of the performance inhibition

Cervical Vertebral Body's Volume as a New Parameter for Predicting the Skeletal Maturation Stages.

Science.gov (United States)

Choi, Youn-Kyung; Kim, Jinmi; Yamaguchi, Tetsutaro; Maki, Koutaro; Ko, Ching-Chang; Kim, Yong-Il

2016-01-01

This study aimed to determine the correlation between the volumetric parameters derived from the images of the second, third, and fourth cervical vertebrae by using cone beam computed tomography with skeletal maturation stages and to propose a new formula for predicting skeletal maturation by using regression analysis. We obtained the estimation of skeletal maturation levels from hand-wrist radiographs and volume parameters derived from the second, third, and fourth cervical vertebrae bodies from 102 Japanese patients (54 women and 48 men, 5-18 years of age). We performed Pearson's correlation coefficient analysis and simple regression analysis. All volume parameters derived from the second, third, and fourth cervical vertebrae exhibited statistically significant correlations (P cervical-vertebra volume as an independent variable with a variance inflation factor less than ten. The explanation power was 81.76%. Volumetric parameters of cervical vertebrae using cone beam computed tomography are useful in regression models. The derived regression model has the potential for clinical application as it enables a simple and quantitative analysis to evaluate skeletal maturation level.

Brief report: Volume dependence of Grüneisen parameter for solids

Indian Academy of Sciences (India)

Brief report: Volume dependence of Grüneisen parameter for solids under extreme ... Shivalik Institute of Engineering and Technology, Aliyaspur, Ambala 133 206, India ... Accepted: 1 October 2015; Final version published online: 9 July 2016 ...

Emission of SNF-oscillations by the plasma - periodic decelerating structure system

International Nuclear Information System (INIS)

Antonov, A.N.; Gestrina, G.N.; Kovpik, O.F.; Kornilov, E.A.; Moiseev, S.S.

1983-01-01

Emission of SHF-oscillations by a magnetoactive plasma inside a decelerating structure (annular waveguide), which is excited by an electron beam, has been studied. The electron beam is formed by a diode electron gun. Pulse duration was 400 μs, beam energy = 10 keV, current - up to 5 A. The beam 1.8 cm in diameter is injected into a glass interaction chamber. The chamber diameter is 20 cm, the length is 1 m. The interaction chamber and electron gun chamber were placed in a homogeneous magnetic field with intensity up to 2.5x10 5 axm -1 . The periodic deceleration structure was located in the interaction chamber coaxially with the electron beam. The structure total length was 40 cm. The working gas, argon, was fed into the structure through a needle injector. It is shown that the three-dimensional waves appearing in the plasma can be transformed by the structure to those emited without plasma density gradients and magnetic field. Conditions of effective separation of the energy of SHF-oscillations from the system: plasm-beam-narrow-slit decelerating structure are found. The above system can be used for amplification and generation of monochromatic oscillations in the millimeter waves range. Results of experimental studies are compared with theoretical calculations

Protection Parameters against the Cracks by the Method of Volume Compensation Dam

Directory of Open Access Journals (Sweden)

Bulatov Georgiy

2016-01-01

Full Text Available This article provides estimates the parameters of protection from cracking dam due to volume compensation method. This article discusses the method of compensation dam volume. This method allows calculating the settings of security causing cracks the dam. Presents graphs of horizontal deformations of elongation calculated surface along the length of the construction and in time. Showing horizontal stress distribution diagram in the ground around the pile in plan and in section. Given all the necessary formulas for the method of compensation of the dam volume.

Density oscillations in laser produced plasma decelerated by ...

Indian Academy of Sciences (India)

during deceleration under the effect of external magnetic field. This has been verified with the help of figure 3, which shows the variation of x-ray intensity emitted from the plasma with laser intensity at 0.01 and 0.6 T magnetic field. Enhancement in the x-ray emission by 2–3 times in the presence of magnetic field has already ...

Effect of varicocelectomy on testis volume and semen parameters in adolescents: a meta-analysis

Directory of Open Access Journals (Sweden)

Tie Zhou

2015-01-01

Full Text Available Varicocele repair in adolescent remains controversial. Our aim is to identify and combine clinical trials results published thus far to ascertain the efficacy of varicocelectomy in improving testis volume and semen parameters compared with nontreatment control. A literature search was performed using Medline, Embase and Web of Science, which included results obtained from meta-analysis, randomized and nonrandomized controlled studies. The study population was adolescents with clinically palpable varicocele with or without the testicular asymmetry or abnormal semen parameters. Cases were allocated to treatment and observation groups, and testis volume or semen parameters were adopted as outcome measures. As a result, seven randomized controlled trials (RCTs and nonrandomized controlled trials studying bilateral testis volume or semen parameters in both treatment and observation groups were identified. Using a random effect model, mean difference of testis volume between the treatment group and the observation group was 2.9 ml (95% confidence interval [CI]: 0.6, 5.2; P< 0.05 for the varicocele side and 1.5 ml (95% CI: 0.3, 2.7; P< 0.05 for the healthy side. The random effect model analysis demonstrated that the mean difference of semen concentration, total semen motility, and normal morphology between the two groups was 13.7 × 10 6 ml−1 (95% CI: −1.4, 28.8; P = 0.075, 2.5% (95% CI: −3.6, 8.6; P= 0.424, and 2.9% (95% CI: −3.0, 8.7; P= 0.336 respectively. In conclusion, although varicocelectomy significantly improved bilateral testis volume in adolescents with varicocele compared with observation cases, semen parameters did not have any statistically significant difference between two groups. Well-planned, properly conducted RCTs are needed in order to confirm the above-mentioned conclusion further and to explore whether varicocele repair in adolescents could improve subsequently spontaneous pregnancy rates.

Effects of deceleration on the humoral antibody response in rats

Science.gov (United States)

Barone, R. P.; Caren, L. D.; Oyama, J.

1985-01-01

Effects of hypergravity, simulated by chronic centrifugation, followed by a return to normal G (deceleration) on the immune system of rats were investigated. Two groups of male rats (28 days at 2.1 G, and 3.1 G) were compared to the control group (1.0 G). The animals were immunized by i.p. injections of sheep red blood cells on days 29, 42, and 57, and bled on days 36, 47, and 62. While the centrifuged rats ate and gainedsignificantly less than the control rats, the antibody titers and the organ/body mass ratios for the adrenal glands, kidneys, lungs, heart, and thymus were unaffected by gravity exposures, as were the values of the hematocrit and the white blood cell counts. It is concluded that deceleration does not adversely affect these particular aspects of the immune system.

Evaluation of the Acceleration and Deceleration Phase-Rectified Slope to Detect and Improve IUGR Clinical Management

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Salvatore Tagliaferri

2015-01-01

Full Text Available Objective. This study used a new method called Acceleration (or Deceleration Phase-Rectified Slope, APRS (or DPRS to analyze computerized Cardiotocographic (cCTG traces in intrauterine growth restriction (IUGR, in order to calculate acceleration- and deceleration-related fluctuations of the fetal heart rate, and to enhance the prediction of neonatal outcome. Method. Cardiotocograms from a population of 59 healthy and 61 IUGR fetuses from the 30th gestation week matched for gestational age were included. APRS and DPRS analysis was compared to the standard linear and nonlinear cCTG parameters. Statistical analysis was performed through the t-test, ANOVA test, Pearson correlation test and receiver operator characteristic (ROC curves (p<0,05. Results. APRS and DPRS showed high performance to discriminate between Healthy and IUGR fetuses, according to gestational week. A linear correlation with the fetal pH at birth was found in IUGR. The area under the ROC curve was 0.865 for APRS and 0.900 for DPRS before the 34th gestation week. Conclusions. APRS and DPRS could be useful in the identification and management of IUGR fetuses and in the prediction of the neonatal outcome, especially before the 34th week of gestation.

Advanced Metal Rubber Sensors for Hypersonic Decelerator Entry Systems, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — NanoSonic proposes to design and develop light-weight, low-modulus, and durable Metal Rubber™ sensors for aeroelastic analysis of Hypersonic Decelerator Entry...

Deceleration-driven wetting transition of "gently" deposited drops on textured hydrophobic surfaces

Science.gov (United States)

Varanasi, Kripa; Kwon, Hyukmin; Paxson, Adam; Patankar, Neelesh

2010-11-01

Many applications of rough superhydrophobic surfaces rely on the presence of droplets in a Cassie state on the substrates. A well established understanding is that if sessile droplets are smaller than a critical size, then the large Laplace pressure induces wetting transition from a Cassie to a Wenzel state, i.e., the liquid impales the roughness grooves. Thus, larger droplets are expected to remain in the Cassie state. In this work we report a surprising wetting transition where even a "gentle" deposition of droplets on rough substrates lead to the transition of larger droplets to the Wenzel state. A hitherto unknown mechanism based on rapid deceleration is identified. It is found that modest amount of energy, during the deposition process, is channeled through rapid deceleration into high water hammer pressure which induces wetting transition. A new "phase" diagram is reported which shows that both large and small droplets can transition to Wenzel states due to the deceleration and Laplace mechanisms, respectively. This novel insight reveals for the first time that the attainment of a Cassie state is more restrictive than previous criteria based on the Laplace pressure transition mechanism.

Velocity-tunable slow beams of cold O2 in a single spin-rovibronic state with full angular-momentum orientation by multistage Zeeman deceleration

Science.gov (United States)

Wiederkehr, A. W.; Schmutz, H.; Motsch, M.; Merkt, F.

2012-08-01

Cold samples of oxygen molecules in supersonic beams have been decelerated from initial velocities of 390 and 450 m s-1 to final velocities in the range between 150 and 280 m s-1 using a 90-stage Zeeman decelerator. (2 + 1) resonance-enhanced-multiphoton-ionization (REMPI) spectra of the 3sσ g 3Π g (C) ? two-photon transition of O2 have been recorded to characterize the state selectivity of the deceleration process. The decelerated molecular sample was found to consist exclusively of molecules in the J ‧‧ = 2 spin-rotational component of the X ? ground state of O2. Measurements of the REMPI spectra using linearly polarized laser radiation with polarization vector parallel to the decelerator axis, and thus to the magnetic-field vector of the deceleration solenoids, further showed that only the ? magnetic sublevel of the N‧‧ = 1, J ‧‧ = 2 spin-rotational level is populated in the decelerated sample, which therefore is characterized by a fully oriented total-angular-momentum vector. By maintaining a weak quantization magnetic field beyond the decelerator, the polarization of the sample could be maintained over the 5 cm distance separating the last deceleration solenoid and the detection region.

Experimental research into motor vehicle oscillations in the case of changeable deceleration

Directory of Open Access Journals (Sweden)

R. Pečeliūnas,

2005-10-01

Full Text Available In this paper processes of oscillation of flexible mounted and inflexible mounted masses are analysed. The tangential effect of the wheel contact with bearing surface is given, thus enabling more precise calculus of vehicle braking parameters. The methodology of research includes the development of mathematical algorithms and theoretical calculus of the analysed processes as well as the presentation of the influence of various factors on vehicle oscillations during braking. Analytical methods and those in figures have been applied for the research. Experimental investigations were carried out applying the electronic device VZM-100 measuring the acceleration of deceleration adapted for synchronous operation together with vibration processing system VAS-21. The expert opportunities for modelling of vehicle movement are extended with the help of the created mathematical models used for the examination of road accidents related to vehicle braking.

Frequency shifting at fiber-optical event horizons: The effect of Raman deceleration

International Nuclear Information System (INIS)

Robertson, S.; Leonhardt, U.

2010-01-01

Pulses in fibers establish analogs of the event horizon [Philbin et al., Science 319, 1367 (2008)]. At a group-velocity horizon, the frequency of a probe wave is shifted. We present a theoretical model of this frequency shifting, taking into account the deceleration of the pulse caused by the Raman effect. The theory shows that the probe-wave spectrum is sensitive to details of the probe-pulse interaction. Our results indicate an additional loss mechanism in the experiment [Philbin et al., Science 319, 1367 (2008)] that has not been accounted for. Our analysis is also valid for more general cases of the interaction of dispersive waves with decelerated solitons.

Braking Deceleration Measurement Using the Video Analysis of Motions by Sw Tracker

Directory of Open Access Journals (Sweden)

Ondruš Ján

2015-06-01

Full Text Available This contribution deals with the issue of car braking, particularly with the one of M1 category. Braking deceleration measurement of the vehicle Mazda 3 MPS was carried out by the declerograph XL MeterTM Pro. The main aim of the contribution is to perform comparison of the process of braking deceleration between the decelograph and the new alternative method of video analysis and to subsequently examine these processes. The test took place at the Rosina airfield, the airstrip in a small village nearby the town of Žilina. The last part of this paper presents the results, evlauation and comparison of the measurements carried out.

Causes for torque degradation during deceleration and the effect on the driving range of battery electric vehicles

Energy Technology Data Exchange (ETDEWEB)

Lieb, Johannes [BMW PEUGEOT CITROEN ELECTRIFICATION, Muenchen (Germany); Wilde, Andreas [BMW Group, Muenchen (Germany); Baeker, Bernard [Dresden Univ. of Technology (Germany). Dept. of Vehicle Mechatronics

2012-11-01

The ability to regain considerable amounts of the kinetic energy during deceleration phases is a key aspect to increase the efficiency of battery electric vehicles (BEV). Especially in urban and highly congested areas brake energy recovery (BER) can drastically improve the vehicle's driving range. However, due to the high power peaks that go along even with moderate braking maneuvers, severe requirements are being put on the electric drivetrain. Any limitation of power in one of the components of the powertrain inevitably leads to degradation of the regenerative brake torque, thus limiting the car's energy regeneration capability. Without an integrated brake system that can compensate the torque variations during deceleration, BER may need to be decreased even further to prevent a loss of driving comfort due to dynamic changes in the vehicle's behavior. This paper deals with the causes of these torque restraints within the electric drivetrain and how they affect the energy consumption and therefore the electric driving range. A simulation environment was set up and verified based on an existing BEV to conduct parameter studies and depict the sensitivities towards environmental influences. The calculated efficiencies are based on standard drive cycles and incorporate continuous fading between regenerative braking and the use of friction brakes. Special attention was laid on the battery system since energy storage still poses a particular challenge in the development of electric vehicles. Also through the high mutual dependence of the various parameters of the battery enviromental influences become most evident. (orig.)

Deceleration of Antiprotons in Support of Antiproton Storage/Utilization Research

International Nuclear Information System (INIS)

Howe, Steven D.; Jackson, Gerald P.; Pearson, J. Boise; Lewis, Raymond A.

2005-01-01

Antimatter has the highest energy density known to mankind. Many concepts have been studied that use antimatter for propulsion. All of these concepts require the development of high density storage. H-bar Technologies, under contract with the NASA Marshall Space Flight Center, has undertaken the first step toward development of high density storage. Demonstration of the ability to store antiprotons in a Penning Trap provides the technology to pursue research in alternative storage methods that may lead to eventually to high density concepts. H-bar Technologies has undertaken research activity on the detailed design and operations required to decelerate and redirect the Fermi National Accelerator Laboratory (FNAL) antiproton beam to lay the groundwork for a source of low energy antiprotons. We have performed a detailed assessment of an antiproton deceleration scheme using the FNAL Main Injector, outlining the requirements to significantly and efficiently lower the energy of antiprotons. This task shall require a combination of: theoretical/computation simulations, development of specialized accelerator controls programming, modification of specific Main Injector hardware, and experimental testing of the modified system. Testing shall be performed to characterize the system with a goal of reducing the beam momentum from 8.9 GeV/c to a level of 1 GeV/c or less. We have designed an antiproton degrader system that will integrate with the FNAL decelerated/transferred beam. The degrader shall be designed to maximize the number of low energy antiprotons with a beam spot sized for acceptance by the Mark I test hardware

Correlation between free-volume parameters and physical properties of polyethylene-nitrile rubber blend

Science.gov (United States)

Gomaa, E.; Mostafa, N.; Mohsen, M.; Mohammed, M.

2004-10-01

Positron annihilation lifetime spectroscopy (PALS) was used to study the immiscibility of a polar nitrile rubber (NBR) that had been blended with pure and waste, low- and high-density polyethylene (PE). The effect of the weight percent of the rubber added to the PE was also investigated. It was found that a complicated variation (positive and negative) in both free-volume parameters (τ3 and I 3) from the values of the initial polymers forms an immiscible blend. These results are supported by a significant broadening in the free-volume hole size distributions. This has been interpreted in terms of interfacial spaces created between the boundaries of the two phases. Furthermore, a correlation was established between the free-volume parameters (τ3 and I 3) and the electrical and mechanical properties of the before mentioned polymer blends as a function of the weight percent of waste PE.

Hypersonic Inflatable Aerodynamic Decelerator (HIAD) Technology Development Overview

Science.gov (United States)

Hughes, Stephen J.; Cheatwood, F. McNeil; Calomino, Anthony M.; Wright, Henry S.; Wusk, Mary E.; Hughes, Monica F.

2013-01-01

The successful flight of the Inflatable Reentry Vehicle Experiment (IRVE)-3 has further demonstrated the potential value of Hypersonic Inflatable Aerodynamic Decelerator (HIAD) technology. This technology development effort is funded by NASA's Space Technology Mission Directorate (STMD) Game Changing Development Program (GCDP). This paper provides an overview of a multi-year HIAD technology development effort, detailing the projects completed to date and the additional testing planned for the future.

Subionization and decelerated-flow in the vicinity of a B-shell star

International Nuclear Information System (INIS)

Zorec, J.

1981-01-01

The author presents a simple calculation in which the wind is decelerated, and cooled, by interaction with the ISM and with the preceeding wind. He balances the momentum originally lying in the wind, having maximum velocity V 0 at a place where its particle concentration is N 0 , against that of wind+ISM at some shell-front, moving at Vsub(r) and with particle-concentration Nsub(r). He assumes the undisturbed ISM had concentration Nsub(m), and that the space between star and wind has been swept clean of ISM material, so that deceleration occurs only at the shell; but he ignores the details of shocks, compression, heating and eventual cooling, etc. (Auth.)

Sensitivity of the amplitude of the single muscle fibre action potential to microscopic volume conduction parameters

NARCIS (Netherlands)

Alberts, B.A.; Rutten, Wim; Wallinga, W.; Boom, H.B.K.

1988-01-01

A microscopic model of volume conduction was applied to examine the sensitivity of the single muscle fibre action potential to variations in parameters of the source and of the volume conductor, such as conduction velocity, intracellular conductivity and intracellular volume fraction. The model

Modal Test of Six-Meter Hypersonic Inflatable Aerodynamic Decelerator

Science.gov (United States)

Abraham, Nijo; Buehrle, Ralph; Templeton, Justin; Lindell, Mike; Hancock, Sean M.

2014-01-01

A modal test was performed on the six-meter Hypersonic Inflatable Aerodynamic Decelerator (HIAD) test article to gain a firm understanding of the dynamic characteristics of the unloaded structure within the low frequency range. The tests involved various configurations of the HIAD to understand the influence of the tri-torus, the varying pressure within the toroids and the influence of straps. The primary test was conducted utilizing an eletrodynamic shaker and the results were verified using a step relaxation technique. The analysis results show an increase in the structure's stiffness with respect to increasing pressure. The results also show the rise of coupled modes with the tri-torus configurations. During the testing activity, the attached straps exhibited a behavior that is similar to that described as fuzzy structures in the literature. Therefore extensive tests were also performed by utilizing foam to mitigate these effects as well as understand the modal parameters of these fuzzy sub structures. Results are being utilized to update the finite element model of the six-meter HIAD and to gain a better understanding of the modeling of complex inflatable structures.

Evaluation of the fetal state by automatic analysis of the heart rate. 2. Deceleration areas and umbilical artery blood pH.

Science.gov (United States)

Tournaire, M; Sturbois, G; Ripoche, A; Le Houezec, R; Breart, G; Chavinie, J; Sureau, C

1976-01-01

Fetal heart rate (FHR) deceleration areas were studied to obtain by objective measurement of the FHR, their prognostic value of the new-born state. 1. There is a reasonably good correlation between FHR deceleration areas and UApH (Tab. II). Such a correlation was found by SHELLEY and TIPTON [6] for the whole deceleration area, and by TOURNAIRE et al. [10] for areas divided in a slightly different way. The correlation coefficients between FHR deceleration areas and Apgar score at 1 minute are within a close range of those of the FHR deceleration area and UApH (Tab. I and II). 2. According to the time relationship between deceleration areas and uterine contractions the best correlation coefficient was obtained surprisingly for total, followed by residual and then simultaneous areas. These results agree with those of SHELLEY and TIPTON [6] suggesting that in practice a simple measurement of the whole deceleration area, regardless of the uterine contractions is a sufficient method in evaluating FHR patterns. 3. The special purpose computer built by the BAUDELOCQUE research group can be used on-line, thus in clinical practice. It was not the case for the manual method [4] or the method using a large programmed computer [10]. 4 The evaluation of deceleration areas appears to have several advantages: 1. It provides objective measurements. 2. The unit used is independant of factors such as display speed or scale of the strip-chart. 3. The data is reduced: A few numbers replace the long descriptions of the usual clinical classifications.

Exploratory field trial of motorcycle autonomous emergency braking (MAEB): Considerations on the acceptability of unexpected automatic decelerations.

Science.gov (United States)

Savino, Giovanni; Pierini, Marco; Thompson, Jason; Fitzharris, Michael; Lenné, Michael G

2016-11-16

Autonomous emergency braking (AEB) acts to slow down a vehicle when an unavoidable impending collision is detected. In addition to documented benefits when applied to passenger cars, AEB has also shown potential when applied to motorcycles (MAEB). However, the feasibility of MAEB as practically applied to motorcycles in the real world is not well understood. In this study we performed a field trial involving 16 riders on a test motorcycle subjected to automatic decelerations, thus simulating MAEB activation. The tests were conducted along a rectilinear path at nominal speed of 40 km/h and with mean deceleration of 0.15 g (15% of full braking) deployed at random times. Riders were also exposed to one final undeclared brake activation with the aim of providing genuinely unexpected automatic braking events. Participants were consistently able to manage automatic decelerations of the vehicle with minor to moderate effort. Results of undeclared activations were consistent with those of standard runs. This study demonstrated the feasibility of a moderate automatic deceleration in a scenario of motorcycle travelling in a straight path, supporting the notion that the application of AEB on motorcycles is practicable. Furthermore, the proposed field trial can be used as a reference for future regulation or consumer tests in order to address safety and acceptability of unexpected automatic decelerations on a motorcycle.

View of the CERN Antiproton Decelerator (AD) and portrait of Prof. Tommy Eriksson, in charge of the AD machine.

CERN Multimedia

Maximilien Brice

2011-01-01

The Antiproton Decelerator (AD) is a storage ring at the CERN laboratory in Geneva. It started operation in 2000. It decelerates antiprotons before sending them to several experiments studying antimatter : ALPHA, ASACUSA, ATRAP and ACE.

Impact of systematic errors on DVH parameters of different OAR and target volumes in Intracavitary Brachytherapy (ICBT)

International Nuclear Information System (INIS)

Mourya, Ankur; Singh, Gaganpreet; Kumar, Vivek; Oinam, Arun S.

2016-01-01

Aim of this study is to analyze the impact of systematic errors on DVH parameters of different OAR and Target volumes in intracavitary brachytherapy (ICBT). To quantify the changes in dose-volume histogram parameters due to systematic errors in applicator reconstruction of brachytherapy planning, known errors in catheter reconstructions have to be introduced in applicator coordinate system

Cervical Vertebral Body’s Volume as a New Parameter for Predicting the Skeletal Maturation Stages

Directory of Open Access Journals (Sweden)

Youn-Kyung Choi

2016-01-01

Full Text Available This study aimed to determine the correlation between the volumetric parameters derived from the images of the second, third, and fourth cervical vertebrae by using cone beam computed tomography with skeletal maturation stages and to propose a new formula for predicting skeletal maturation by using regression analysis. We obtained the estimation of skeletal maturation levels from hand-wrist radiographs and volume parameters derived from the second, third, and fourth cervical vertebrae bodies from 102 Japanese patients (54 women and 48 men, 5–18 years of age. We performed Pearson’s correlation coefficient analysis and simple regression analysis. All volume parameters derived from the second, third, and fourth cervical vertebrae exhibited statistically significant correlations (P<0.05. The simple regression model with the greatest R-square indicated the fourth-cervical-vertebra volume as an independent variable with a variance inflation factor less than ten. The explanation power was 81.76%. Volumetric parameters of cervical vertebrae using cone beam computed tomography are useful in regression models. The derived regression model has the potential for clinical application as it enables a simple and quantitative analysis to evaluate skeletal maturation level.

Comparative Assessment of Torso and Seat Mounted Restraint Systems using Manikins on the Vertical Deceleration Tower

Science.gov (United States)

2017-03-01

AFRL-RH-WP-TR-2017-0044 Comparative Assessment of Torso and Seat Mounted Restraint Systems using Manikins on the Vertical ...Restraint Systems using Manikins on the Vertical Deceleration Tower 5a. CONTRACT NUMBER FA8650-14-D-6500-0001 5b. GRANT NUMBER 5c. PROGRAM...experimental effort involving a series of +z-axis impact tests was conducted on the 711th Human Performance Wing’s Vertical Deceleration Tower (VDT

Experimental verification of the CLIC Decelerator with the test Beam Line in the CLIC test facility 3

CERN Document Server

Lillestøl, R L; Olvegård, M; Rabiller, A N; Sterbini, G; Adli, E

2012-01-01

The Test Beam Line in the CLIC Test Facility 3 is the first prototype of the CLIC drive beam decelerator. The main purpose of the experiment is to demonstrate efficient 12 GHz rf power production and stable transport of an electron drive beam during deceleration. The Test Beam Line consists of a FODO structure with high precision BPMs and quadrupoles mounted on mechanical movers for precisebeam alignment. Nine out of the planned 16 Power Extraction and Transfer Structures have currently been installed and commissioned. We correlate rf power production measurements with the drive beam deceleration measurements, and compare the two measurements to the theoretical predictions. We also discuss the impact of the drive beam bunch length and bunch combination on the measurements.

Estimating deep seafloor interface and volume roughness parameters using the multibeam-hydrosweep system

Digital Repository Service at National Institute of Oceanography (India)

Chakraborty, B.; Schenke, H.W.; Kodagali, V.N.; Hagen, R.

composite roughness model, including water-sediment interface roughness and sediment volume roughness parameters the data was modeled. The model effectively uses the near normal incidence angle backscatter to determine the seafloor interface roughness...

An ultra low noise AC beam transformer for deceleration and diagnostics of low intensity beams

CERN Document Server

González, C

1999-01-01

The design of a broad band ultra-low noise ferrite loaded AC beam transformer is presented. It is designed for use in the CERN Antiproton Decelerator (AD), where beams of a few 107 charges must be decelerated from 3.5 GeV/c to 100 MeV/c. It is used in the RF beam-phase loop, and for intensity and bunch shape measurements during deceleration. When the beam is debunched for cooling on magnetic flat tops, the pick-up is used for measurements of intensity and momentum distribution by means of longitudinal Schottky scans. When used as Schottky pick-up, the signal to noise ratio should be better by about 40 dB than the existing stripline based longitudinal Schottky pick-up. The integrated design of pick-up and associated low-noise amplifier is presented. The achieved noise performance of a few from 1 to 3 MHz is obtained by attaching a low-noise, high-impedance silicon JFET (junction field effect transistor) amplifier to a high-Q resonant ferrite loaded cavity, and then eliminating the resonant response by low-nois...

Deceleration phase of inertial confinement fusion implosions

International Nuclear Information System (INIS)

Betti, R.; Anderson, K.; Goncharov, V.N.; McCrory, R.L.; Meyerhofer, D.D.; Skupsky, S.; Town, R.P.J.

2002-01-01

A model for the deceleration phase and marginal ignition of imploding capsules is derived by solving a set of ordinary differential equations describing the hot-spot energy balance and the shell dynamics including the return shock propagation. It is found that heat flux leaving the hot spot goes back in the form of internal energy and PdV work of the material ablated off the inner-shell surface. Though the hot-spot temperature is reduced by the heat conduction losses, the hot-spot density increases due to the ablated material in such a way that the hot-spot pressure is approximately independent of heat conduction. For hot-spot temperatures exceeding approximately 7 keV, the ignition conditions are not affected by heat conduction losses that are recycled into the hot spot by ablation. Instead, the only significant internal energy loss is due to the hot-spot expansion tamped by the surrounding shell. The change of adiabat induced by the shock is also calculated for marginally igniting shells, and the relation between the in-flight and stagnation adiabats is in general agreement with the numerical fit of LASNEX simulations by Herrmann et al. [Nucl. Fusion 41, 99 (2001)] and the self-similar solution of Kemp et al. [Phys. Rev. Lett. 15, 3336 (2001)]. The minimum kinetic energy required for ignition is also calculated from the same model and shown to be in good agreement with the numerical fit of LASNEX simulations. It is also found that mass ablation leads to a significant reduction of the deceleration phase Rayleigh-Taylor instability growth rates and to the suppression of short wavelength modes

Electron-optical design parameters for a high-resolution electron monochromator

International Nuclear Information System (INIS)

Tanaka, H.; Huebner, R.H.

1976-01-01

Detailed design parameters of a new, high-resolution electron monochromator are presented. The design utilizes a hemispherical filter as the energy-dispersing element and combines both cylindrical and aperture electrostatic lenses to accelerate, decelerate, transport, and focus the electron beam from the cathode to the interaction region

Beam Stability in the Drive-Beam Decelerator of CLIC Using Structures of High-Order Symmetry

CERN Document Server

Millich, Antonio; Schulte, Daniel

1999-01-01

The RF power necessary to accelerate the main beam of the Compact Linear Collider (CLIC) is produced by decelerating a high-current drive beam in Power Extraction and Transfer Structures (PETS). The reference structure is not cylindrically symmetric but has longitudinal waveguides carved into the inner surface. This gives rise to a transverse component of the main longitudinal mode which can not be damped, in contrast to the transverse dipole wake- field. The field is non-linear and couples the motion of the particles in the two planes. Limits of the stability of the decelerated beam are investigated for different structures.

Compact disposal of high-energy electron beams using passive or laser-driven plasma decelerating stage

Energy Technology Data Exchange (ETDEWEB)

Bonatto, A.; Schroeder, C. B.; Vay, J. -L.; Geddes, C. R.; Benedetti, C.; Esarey and, E.; Leemans, W. P.

2014-07-13

A plasma decelerating stage is investigated as a compact alternative for the disposal of high-energy beams (beam dumps). This could benefit the design of laser-driven plasma accelerator (LPA) applications that require transportability and or high-repetition-rate operation regimes. Passive and laser-driven (active) plasma-based beam dumps are studied analytically and with particle-in-cell (PIC) simulations in a 1D geometry. Analytical estimates for the beam energy loss are compared to and extended by the PIC simulations, showing that with the proposed schemes a beam can be efficiently decelerated in a centimeter-scale distance.

Continuous all-optical deceleration of molecular beams and demonstration with Rb atoms

Science.gov (United States)

Long, Xueping; Jayich, Andrew; Campbell, Wesley

2017-04-01

Ultracold samples of molecules are desirable for a variety of applications, such as many-body physics, precision measurement and quantum information science. However, the pursuit of ultracold molecules has achieved limited success: spontaneous emission into many different dark states makes it hard to optically decelerate molecules to trappable speed. We propose to address this problem with a general optical deceleration technique that exploits a pump-dump pulse pair from a mode-locked laser. A molecular beam is first excited by a counter-propagating ``pump'' pulse. The molecular beam is then driven back to the initial ground state by a co-propagating ``dump'' pulse via stimulated emission. The delay between the pump and dump pulse is set to be shorter than the excited state lifetimes in order to limit decays to dark states. We report progress benchmarking this stimulated force by accelerating a cold sample of neutral Rb atoms.

A Monte Carlo study of the impact of the choice of rectum volume definition on estimates of equivalent uniform doses and the volume parameter

International Nuclear Information System (INIS)

Kvinnsland, Yngve; Muren, Ludvig Paul; Dahl, Olav

2004-01-01

Calculations of normal tissue complication probability (NTCP) values for the rectum are difficult because it is a hollow, non-rigid, organ. Finding the true cumulative dose distribution for a number of treatment fractions requires a CT scan before each treatment fraction. This is labour intensive, and several surrogate distributions have therefore been suggested, such as dose wall histograms, dose surface histograms and histograms for the solid rectum, with and without margins. In this study, a Monte Carlo method is used to investigate the relationships between the cumulative dose distributions based on all treatment fractions and the above-mentioned histograms that are based on one CT scan only, in terms of equivalent uniform dose. Furthermore, the effect of a specific choice of histogram on estimates of the volume parameter of the probit NTCP model was investigated. It was found that the solid rectum and the rectum wall histograms (without margins) gave equivalent uniform doses with an expected value close to the values calculated from the cumulative dose distributions in the rectum wall. With the number of patients available in this study the standard deviations of the estimates of the volume parameter were large, and it was not possible to decide which volume gave the best estimates of the volume parameter, but there were distinct differences in the mean values of the values obtained

The relationships between tracheal index and lung volume parameters in mild-to-moderate COPD

Energy Technology Data Exchange (ETDEWEB)

Eom, Jung Seop, E-mail: ejs00@hanmail.net [Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul 135-710 (Korea, Republic of); Lee, Geewon, E-mail: rabkingdom@naver.com [Department of Radiology, Pusan National University Hospital, 179 Gudeok-ro, Seo-gu, Busan 602-739 (Korea, Republic of); Lee, Ho Yun, E-mail: hoyunlee96@gmail.com [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul 135-710 (Korea, Republic of); Oh, Jin Young, E-mail: indr71@hanmail.net [Division of Pulmonology, Department of Internal Medicine, Dongguk University Ilsan Medical Center, 814 Siksa-dong, Ilsandong-gu, Goyang-si, Gyeonggi-do 410-773 (Korea, Republic of); Woo, Sook-young, E-mail: sookyoung12.woo@samsung.com [Biostatistics Team, Samsung Biomedical Research Institute, 81 Irwon-ro, Gangnam-gu, Seoul 135-710 (Korea, Republic of); Jeon, Kyeongman, E-mail: kjeon@skku.edu [Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul 135-710 (Korea, Republic of); Um, Sang-Won, E-mail: sangwonum@skku.edu [Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul 135-710 (Korea, Republic of); Koh, Won-Jung, E-mail: wjkoh@skku.edu [Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul 135-710 (Korea, Republic of); Suh, Gee Young, E-mail: suhgy@skku.edu [Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul 135-710 (Korea, Republic of); and others

2013-12-01

Background: Although elongated morphological changes in the trachea are known to be related to lung function in chronic obstructive pulmonary disease (COPD), whether the tracheal morphological changes are associated with airflow limitations or overinflation of the lung in the early stages of COPD has not yet been determined. Thus, our aim was to investigate the association of tracheal index (TI) with lung function parameters, including lung volume parameters, in COPD patients with mild-to-moderate airflow limitations. Materials and methods: A retrospective study was conducted in 193 COPD patients with GOLD grades 1–2 (post-bronchodilator forced expiratory volume in 1 s [FEV{sub 1}] ≥ 50% predicted with FEV{sub 1}/forced vital capacity ratio ≤ 70%; age range, 40–81) and 193 age- and gender-matched subjects with normal lung function as a control group (age range, 40–82). Two independent observers measured TI at three anatomical levels on chest radiographs and CT scans. Results: Compared with the control group, TI was reduced significantly and “saber-sheath trachea” was observed more frequently in COPD patients. Patients with GOLD grade 2 disease had a lower TI than those with GOLD grade 1. TI had apparent inverse correlations with total lung capacity, functional residual capacity, and residual volume, regardless of the anatomical level of the trachea. Even after adjustments for covariates, this association persisted. Conclusions: TI is reduced even in mild-to-moderate COPD patients, and TI measured on chest CT shows significant inverse relationships with all lung volume parameters assessed, suggesting that tracheal morphology may change during the early stages of COPD.

The relationships between tracheal index and lung volume parameters in mild-to-moderate COPD

International Nuclear Information System (INIS)

Eom, Jung Seop; Lee, Geewon; Lee, Ho Yun; Oh, Jin Young; Woo, Sook-young; Jeon, Kyeongman; Um, Sang-Won; Koh, Won-Jung; Suh, Gee Young

2013-01-01

Background: Although elongated morphological changes in the trachea are known to be related to lung function in chronic obstructive pulmonary disease (COPD), whether the tracheal morphological changes are associated with airflow limitations or overinflation of the lung in the early stages of COPD has not yet been determined. Thus, our aim was to investigate the association of tracheal index (TI) with lung function parameters, including lung volume parameters, in COPD patients with mild-to-moderate airflow limitations. Materials and methods: A retrospective study was conducted in 193 COPD patients with GOLD grades 1–2 (post-bronchodilator forced expiratory volume in 1 s [FEV 1 ] ≥ 50% predicted with FEV 1 /forced vital capacity ratio ≤ 70%; age range, 40–81) and 193 age- and gender-matched subjects with normal lung function as a control group (age range, 40–82). Two independent observers measured TI at three anatomical levels on chest radiographs and CT scans. Results: Compared with the control group, TI was reduced significantly and “saber-sheath trachea” was observed more frequently in COPD patients. Patients with GOLD grade 2 disease had a lower TI than those with GOLD grade 1. TI had apparent inverse correlations with total lung capacity, functional residual capacity, and residual volume, regardless of the anatomical level of the trachea. Even after adjustments for covariates, this association persisted. Conclusions: TI is reduced even in mild-to-moderate COPD patients, and TI measured on chest CT shows significant inverse relationships with all lung volume parameters assessed, suggesting that tracheal morphology may change during the early stages of COPD

Influence of decelerating flow on incipient motion of a gravel-bed ...

Indian Academy of Sciences (India)

decelerating flow is presented. Experiments were carried out in a flume with two median grain sizes, d 50 = 16·7 mm for a fixed-bed case and d 50 = 8 mm for a mobile bed case. In addition, an effort is made to determine a simplified method for ...

Three-dimensional hydrodynamics of the deceleration stage in inertial confinement fusion

Energy Technology Data Exchange (ETDEWEB)

Weber, C. R., E-mail: weber30@llnl.gov; Clark, D. S.; Cook, A. W.; Eder, D. C.; Haan, S. W.; Hammel, B. A.; Hinkel, D. E.; Jones, O. S.; Marinak, M. M.; Milovich, J. L.; Patel, P. K.; Robey, H. F.; Salmonson, J. D.; Sepke, S. M.; Thomas, C. A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2015-03-15

The deceleration stage of inertial confinement fusion implosions is modeled in detail using three-dimensional simulations designed to match experiments at the National Ignition Facility. In this final stage of the implosion, shocks rebound from the center of the capsule, forming the high-temperature, low-density hot spot and slowing the incoming fuel. The flow field that results from this process is highly three-dimensional and influences many aspects of the implosion. The interior of the capsule has high-velocity motion, but viscous effects limit the range of scales that develop. The bulk motion of the hot spot shows qualitative agreement with experimental velocity measurements, while the variance of the hot spot velocity would broaden the DT neutron spectrum, increasing the inferred temperature by 400–800 eV. Jets of ablator material are broken apart and redirected as they enter this dynamic hot spot. Deceleration stage simulations using two fundamentally different rad-hydro codes are compared and the flow field is found to be in good agreement.

Three-dimensional hydrodynamics of the deceleration stage in inertial confinement fusion

International Nuclear Information System (INIS)

Weber, C. R.; Clark, D. S.; Cook, A. W.; Eder, D. C.; Haan, S. W.; Hammel, B. A.; Hinkel, D. E.; Jones, O. S.; Marinak, M. M.; Milovich, J. L.; Patel, P. K.; Robey, H. F.; Salmonson, J. D.; Sepke, S. M.; Thomas, C. A.

2015-01-01

The deceleration stage of inertial confinement fusion implosions is modeled in detail using three-dimensional simulations designed to match experiments at the National Ignition Facility. In this final stage of the implosion, shocks rebound from the center of the capsule, forming the high-temperature, low-density hot spot and slowing the incoming fuel. The flow field that results from this process is highly three-dimensional and influences many aspects of the implosion. The interior of the capsule has high-velocity motion, but viscous effects limit the range of scales that develop. The bulk motion of the hot spot shows qualitative agreement with experimental velocity measurements, while the variance of the hot spot velocity would broaden the DT neutron spectrum, increasing the inferred temperature by 400–800 eV. Jets of ablator material are broken apart and redirected as they enter this dynamic hot spot. Deceleration stage simulations using two fundamentally different rad-hydro codes are compared and the flow field is found to be in good agreement

On the mechanism of self-deceleration of the thin oxide film growth

CERN Document Server

Mukhambetov, D G

2002-01-01

The objective of this work was to investigate the kinetics of the two-phase oxide film growth on the alpha-Fe surface at temperatures of 650-750 K. We experimentally determined that the film thickness (h)-time oxidation (tau) relationship in the range denoted above is a logarithmic function, whereas Cabrera and Mott's theory gives a square law of film growth. In our work, analytical treatment of experimental data was made based on this theory, but we propose that self-deceleration of the film growth is caused not by attenuation of the electric intensity in the film because of an increase of h but by the shielding influence of the space charge of diffusing ions and electrons in that oxide film. With that purpose in view, the Debye shielding distance for plasma substance state in the oxide film was taken into consideration. The logarithmic law of oxide film growth was derived. Estimated calculations of this law's parameters were made that quantitatively correspond with literature data. The results obtained were...

Hot-spot dynamics and deceleration-phase Rayleigh-Taylor instability of imploding inertial confinement fusion capsules

International Nuclear Information System (INIS)

Betti, R.; Umansky, M.; Lobatchev, V.; Goncharov, V.N.; McCrory, R.L.

2001-01-01

A model for the deceleration phase of imploding inertial confinement fusion capsules is derived by solving the conservation equations for the hot spot. It is found that heat flux leaving the hot spot goes back in the form of internal energy and pdV work of the material ablated off the inner shell surface. Though the hot-spot temperature is reduced by the heat conduction losses, the hot-spot density increases due to the ablated material in such a way that the hot-spot pressure is approximately independent of heat conduction. For direct-drive National Ignition Facility-like capsules, the ablation velocity off the shell inner surface is of the order of tens μm/ns, the deceleration of the order of thousands μm/ns2, and the density-gradient scale length of the order a few μm. Using the well-established theory of the ablative Rayleigh-Taylor instability, it is shown that the growth rates of the deceleration phase instability are significantly reduced by the finite ablative flow and the unstable spectrum exhibits a cutoff for mode numbers of about l≅90

Estimation of left ventricular operating stiffness from Doppler early filling deceleration time in humans.

Science.gov (United States)

Garcia, M J; Firstenberg, M S; Greenberg, N L; Smedira, N; Rodriguez, L; Prior, D; Thomas, J D

2001-02-01

Shortened early transmitral deceleration times (E(DT)) have been qualitatively associated with increased filling pressure and reduced survival in patients with cardiac disease and increased left ventricular operating stiffness (K(LV)). An equation relating K(LV) quantitatively to E(DT) has previously been described in a canine model but not in humans. During several varying hemodynamic conditions, we studied 18 patients undergoing open-heart surgery. Transesophageal echocardiographic two-dimensional volumes and Doppler flows were combined with high-fidelity left atrial (LA) and left ventricular (LV) pressures to determine K(LV). From digitized Doppler recordings, E(DT) was measured and compared against changes in LV and LA diastolic volumes and pressures. E(DT) (180 +/- 39 ms) was inversely associated with LV end-diastolic pressures (r = -0.56, P = 0.004) and net atrioventricular stiffness (r = -0.55, P = 0.006) but had its strongest association with K(LV) (r = -0.81, P < 0.001). K(LV) was predicted assuming a nonrestrictive orifice (K(nonrest)) from E(DT) as K(nonrest) = (0.07/E(DT))(2) with K(LV) = 1.01 K(nonrest) - 0.02; r = 0.86, P < 0.001, DeltaK (K(nonrest) - K(LV)) = 0.02 +/- 0.06 mm Hg/ml. In adults with cardiac disease, E(DT) provides an accurate estimate of LV operating stiffness and supports its application as a practical noninvasive index in the evaluation of diastolic function.

Cervical Vertebral Body's Volume as a New Parameter for Predicting the Skeletal Maturation Stages

OpenAIRE

Choi, Youn-Kyung; Kim, Jinmi; Yamaguchi, Tetsutaro; Maki, Koutaro; Ko, Ching-Chang; Kim, Yong-Il

2016-01-01

This study aimed to determine the correlation between the volumetric parameters derived from the images of the second, third, and fourth cervical vertebrae by using cone beam computed tomography with skeletal maturation stages and to propose a new formula for predicting skeletal maturation by using regression analysis. We obtained the estimation of skeletal maturation levels from hand-wrist radiographs and volume parameters derived from the second, third, and fourth cervical vertebrae bodies ...

Physics at CERN's Antiproton Decelerator

CERN Document Server

Hori, M

2013-01-01

The Antiproton Decelerator of CERN began operation in 1999 to serve experiments for studies of CPT invariance by precision laser and microwave spectroscopy of antihydrogen ($\\bar{\\rm H}$) and antiprotonic helium ($\\bar{p}{\\rm He}^+$). The first 12 years of operation saw cold $\\bar{\\rm H}$ synthesized by overlapping clouds of positrons ($e^+$) and antiprotons ($\\bar{p}$) confined in magnetic Penning traps. Cold $\\bar{\\rm H}$ was also produced in collisions between Rydberg positronium atoms and $\\bar{p}$. Ground-state $\\bar{\\rm H}$ was later trapped for up to $\\sim 1000$ s in a magnetic bottle trap, and microwave transitions excited between its hyperfine levels. In the $\\bar{p}{\\rm He}^+$ atom, UV transitions were measured to a precision of (2.3-5) $\\times$ $10^{-9}$ by sub-Doppler two-photon laser spectroscopy. From this the antiproton-to-electron mass ratio was determined as $M_{\\bar{p}}/m_e=$1836.1526736(23), which agrees with the p value. Microwave spectroscopy of $\\bar{p}{\\rm He}^+$ yielded a measurement o...

CT-guided intracavitary radiotherapy for cervical cancer: Comparison of conventional point A plan with clinical target volume-based three-dimensional plan using dose-volume parameters

International Nuclear Information System (INIS)

Shin, Kyung Hwan; Kim, Tae Hyun; Cho, Jung Keun; Kim, Joo-Young; Park, Sung Yong; Park, Sang-Yoon; Kim, Dae Yong; Chie, Eui Kyu; Pyo, Hong Ryull; Cho, Kwan Ho

2006-01-01

Purpose: To perform an intracavitary radiotherapy (ICR) plan comparison between the conventional point A plan (conventional plan) and computed tomography (CT)-guided clinical target volume-based plan (CTV plan) by analysis of the quantitative dose-volume parameters and irradiated volumes of organs at risk in patients with cervical cancer. Methods and Materials: Thirty plans for 192 Ir high-dose-rate ICR after 30-40-Gy external beam radiotherapy were investigated. CT images were acquired at the first ICR session with artifact-free applicators in place. The gross tumor volume, clinical target volume (CTV), point A, and International Commission on Radiation Units and Measurements Report 38 rectal and bladder points were defined on reconstructed CT images. A fractional 100% dose was prescribed to point A in the conventional plan and to the outermost point to cover all CTVs in the CTV plan. The reference volume receiving 100% of the prescribed dose (V ref ), and the dose-volume parameters of the coverage index, conformal index, and external volume index were calculated from the dose-volume histogram. The bladder, rectal point doses, and percentage of volumes receiving 50%, 80%, and 100% of the prescribed dose were also analyzed. Results: Conventional plans were performed, and patients were categorized on the basis of whether the 100% isodose line of point A prescription dose fully encompassed the CTV (Group 1, n = 20) or not (Group 2, n = 10). The mean gross tumor volume (11.6 cm 3 ) and CTV (24.9 cm 3 ) of Group 1 were smaller than the corresponding values (23.7 and 44.7 cm 3 , respectively) for Group 2 (p = 0.003). The mean V ref for all patients was 129.6 cm 3 for the conventional plan and 97.0 cm 3 for the CTV plan (p = 0.003). The mean V ref in Group 1 decreased markedly with the CTV plan (p < 0.001). For the conventional and CTV plans in all patients, the mean coverage index, conformal index, and external volume index were 0.98 and 1.0, 0.23 and 0.34, and 3.86 and

Photogrammetry of a Hypersonic Inflatable Aerodynamic Decelerator

Science.gov (United States)

Kushner, Laura Kathryn; Littell, Justin D.; Cassell, Alan M.

2013-01-01

In 2012, two large-scale models of a Hypersonic Inflatable Aerodynamic decelerator were tested in the National Full-Scale Aerodynamic Complex at NASA Ames Research Center. One of the objectives of this test was to measure model deflections under aerodynamic loading that approximated expected flight conditions. The measurements were acquired using stereo photogrammetry. Four pairs of stereo cameras were mounted inside the NFAC test section, each imaging a particular section of the HIAD. The views were then stitched together post-test to create a surface deformation profile. The data from the photogram- metry system will largely be used for comparisons to and refinement of Fluid Structure Interaction models. This paper describes how a commercial photogrammetry system was adapted to make the measurements and presents some preliminary results.

Accelerated and decelerated expansion in a causal dissipative cosmology

Science.gov (United States)

Cruz, Miguel; Cruz, Norman; Lepe, Samuel

2017-12-01

In this work we explore a new cosmological solution for an universe filled with one dissipative fluid, described by a barotropic equation of state (EoS) p =ω ρ , in the framework of the full Israel-Stewart theory. The form of the bulk viscosity has been assumed of the form ξ =ξ0ρ1 /2. The relaxation time is taken to be a function of the EoS, the bulk viscosity and the speed of bulk viscous perturbations, cb. The solution presents an initial singularity, where the curvature scalar diverges as the scale factor goes to zero. Depending on the values for ω , ξ0, cb accelerated and decelerated cosmic expansion can be obtained. In the case of accelerated expansion, the viscosity drives the effective EoS to be of quintessence type, for the single fluid with positive pressure. Nevertheless, we show that only the solution with decelerated expansion satisfies the thermodynamics conditions d S /d t >0 (growth of the entropy) and d2S /d t2<0 (convexity condition). We show that an exact stiff matter EoS is not allowed in the framework of the full causal thermodynamic approach; and in the case of a EoS very close to the stiff matter regime, we found that dissipative effects becomes negligible so the entropy remains constant. Finally, we show numerically that the solution is stable under small perturbations.

Cineradiographic Analysis of Mouse Postural Response to Alteration of Gravity and Jerk (Gravity Deceleration Rate

Directory of Open Access Journals (Sweden)

Katsuya Hasegawa

2014-04-01

Full Text Available The ability to maintain the body relative to the external environment is important for adaptation to altered gravity. However, the physiological limits for adaptation or the disruption of body orientation are not known. In this study, we analyzed postural changes in mice upon exposure to various low gravities. Male C57BL6/J mice (n = 6 were exposed to various gravity-deceleration conditions by customized parabolic flight-maneuvers targeting the partial-gravity levels of 0.60, 0.30, 0.15 and μ g (<0.001 g. Video recordings of postural responses were analyzed frame-by-frame by high-definition cineradiography and with exact instantaneous values of gravity and jerk. As a result, the coordinated extension of the neck, spine and hindlimbs was observed during the initial phase of gravity deceleration. Joint angles widened to 120%–200% of the reference g level, and the magnitude of the thoracic-curvature stretching was correlated with gravity and jerk, i.e., the gravity deceleration rate. A certain range of jerk facilitated mouse skeletal stretching efficiently, and a jerk of −0.3~−0.4 j (g/s induced the maximum extension of the thoracic-curvature. The postural response of animals to low gravity may undergo differential regulation by gravity and jerk.

Implementation and Assessment of a Time-Accurate Aeroelastic Model for Analysis of Inflatable Aerodynamic Decelerators

Data.gov (United States)

National Aeronautics and Space Administration — In light of NASA's goal for planetary exploration, the development of new technology is imperative. The aerodynamic deceleration technique used during Entry,...

Effect of intravenous contrast agent volume on colorectal cancer vascular parameters as measured by perfusion computed tomography

International Nuclear Information System (INIS)

Goh, V.; Bartram, C.; Halligan, S.

2009-01-01

Aim: To determine the effect of two different contrast agent volumes on quantitative and semi-quantitative vascular parameters as measured by perfusion computed tomography (CT) in colorectal cancer. Materials and methods: Following ethical approval and informed consent, eight prospectively recruited patients with proven colorectal adenocarcinoma underwent two separate perfusion CT studies on the same day after (a) 100 ml and (b) 50 ml of a 340 mg/ml iodinated contrast medium, respectively. Quantitative (blood volume, blood flow, permeability surface area product) and semi-quantitative (peak enhancement, time to peak enhancement) tumour vascular parameters were determined using commercial software based on distributed parameter analysis and compared using t-testing. Results: Tumour blood volume, blood flow, and permeability surface area product were not substantially different following the injection of 100 ml and 50 ml contrast medium: 6.12 versus 6.23 ml/100 g tissue; 73.4 versus 71.3 ml/min/100 g tissue; 15.6 versus 15.3 ml/min/100 g tissue for 100 and 50 ml, respectively; p > 0.05. Tumour peak enhancement and time to peak were significantly greater following the injection of 100 ml versus 50 ml contrast medium: 41.2 versus 28.5 HU; 16.1 versus 11.8 s for 100 ml and 50 ml, respectively; p = 0.002; p = 0.0003. Conclusion: Quantitative parameters do not appear to change substantially with a higher contrast agent volume suggesting a combined diagnostic staging-perfusion CT study following a single injection is feasible for colorectal cancer

Collective effects and experimental verification of the CLIC drive beam and decelerator

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00418229; Stapnes, Steinar; Adli, Erik

The Compact Linear Collider (CLIC) is a potential next-generation particle collider, in which electrons and positrons collide at a center-of-mass energy of up to 3 TeV. In order to reach a high accelerating gradient and reduce the length of the machine, CLIC uses a novel two-beam scheme. Here, the acceleration energy for the main beam is provided by energy extraction from a secondary electron drive beam, by the use of Power Extraction and Transfer Structures (PETS). This Ph.D. thesis describes deceleration measurements from the CLIC Test Facility 3 at CERN, from a beam that had up to 37 % of its kinetic energy converted into 12 GHz rf power. The results are part of the feasibility demonstration of the CLIC scheme. The measured difference in beam energy of the decelerated beam is correlated with particle tracking simulations and with predictions based on analytical formulae, and a very good agreement is demonstrated. The evolution of the transverse emittance was also studied, since it is critical to contain th...

Gas cooled fast reactor control rod drive mechanism deceleration unit. Test program

International Nuclear Information System (INIS)

Wagner, T.H.

1981-10-01

This report presents the results of the airtesting portion of the proof-of-principle testing of a Control Rod Scram Deceleration Device developed for use in the Gas Cooled Fast Reactor (GCFR). The device utilizes a grooved flywheel to decelerate the translating assembly (T/A). Two cam followers on the translating assembly travel in the flywheel grooves and transfer the energy of the T/A to the flywheel. The grooves in the flywheel are straight for most of the flywheel length. Near the bottom of the T/A stroke the grooves are spiraled in a decreasing slope helix so that the cam followers accelerate the flywheel as they transfer the energy of the falling T/A. To expedite proof-of-principle testing, some of the materials used in the fabrication of certain test article components were not prototypic. With these exceptions the concept appears to be acceptable. The initial test of 300 scrams was completed with only one failure and the failure was that of a non-prototypic cam follower outer sleeve material

Pramana – Journal of Physics | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Pramana – Journal of Physics; Volume 68; Issue 5. Issue front cover thumbnail. Volume 68, Issue 5. May 2007, pages 707-880. pp 707-720 Research Articles. Bianchi Type-II inflationary models with constant deceleration parameter in general relativity · C P Singh S Kumar · More Details Abstract Fulltext ...

Does Missing Classes Decelerate Student Exam Performance Progress? Empirical Evidence and Policy Implications

Science.gov (United States)

Lin, Tin-Chun

2014-01-01

A total of 389 business students in undergraduate introductory microeconomics classes in spring 2007, 2009, and 2011, and fall 2012 participated in an exam performance progress study. Empirical evidence suggested that missing classes decelerates and hampers high-performing students' exam performance progress. Nevertheless, the evidence does…

Extension of the direct statistical approach to a volume parameter model (non-integer splitting)

International Nuclear Information System (INIS)

Burn, K.W.

1990-01-01

The Direct Statistical Approach is a rigorous mathematical derivation of the second moment for surface splitting and Russian Roulette games attached to the Monte Carlo modelling of fixed source particle transport. It has been extended to a volume parameter model (involving non-integer ''expected value'' splitting), and then to a cell model. The cell model gives second moment and time functions that have a closed form. This suggests the possibility of two different methods of solution of the optimum splitting/Russian Roulette parameters. (author)

Deceleration of the solar wind in the earth's foreshock region - Isee 2 and Imp 8 observations

Science.gov (United States)

Bonifazi, C.; Moreno, G.; Lazarus, A. J.; Sullivan, J. D.

1980-01-01

The deceleration of the solar wind in the region of the interplanetary space filled by ions backstreaming from the earth's bow shock and associated waves is studied using a two-spacecraft technique. This deceleration depends on the solar wind bulk velocity; at low velocities (below 300 km/s) the velocity decrease is about 5 km/s, while at higher velocities (above 400 km/s) the decrease may be as large as 30 km/s. The energy balance shows that the kinetic energy loss far exceeds the thermal energy which is possibly gained by the solar wind; therefore at least part of this energy must go into waves and/or into the backstreaming ions.

Parameter Analysis of the VPIN (Volume synchronized Probability of Informed Trading) Metric

Energy Technology Data Exchange (ETDEWEB)

Song, Jung Heon; Wu, Kesheng; Simon, Horst D.

2014-03-01

VPIN (Volume synchronized Probability of Informed trading) is a leading indicator of liquidity-induced volatility. It is best known for having produced a signal more than hours before the Flash Crash of 2010. On that day, the market saw the biggest one-day point decline in the Dow Jones Industrial Average, which culminated to the market value of $1 trillion disappearing, but only to recover those losses twenty minutes later (Lauricella 2010). The computation of VPIN requires the user to set up a handful of free parameters. The values of these parameters significantly affect the effectiveness of VPIN as measured by the false positive rate (FPR). An earlier publication reported that a brute-force search of simple parameter combinations yielded a number of parameter combinations with FPR of 7%. This work is a systematic attempt to find an optimal parameter set using an optimization package, NOMAD (Nonlinear Optimization by Mesh Adaptive Direct Search) by Audet, le digabel, and tribes (2009) and le digabel (2011). We have implemented a number of techniques to reduce the computation time with NOMAD. Tests show that we can reduce the FPR to only 2%. To better understand the parameter choices, we have conducted a series of sensitivity analysis via uncertainty quantification on the parameter spaces using UQTK (Uncertainty Quantification Toolkit). Results have shown dominance of 2 parameters in the computation of FPR. Using the outputs from NOMAD optimization and sensitivity analysis, We recommend A range of values for each of the free parameters that perform well on a large set of futures trading records.

Design parameters and source terms: Volume 2, Source terms: Revision 0

International Nuclear Information System (INIS)

1987-09-01

The Design Parameters and Source Terms Document was prepared in accordance with DOE request and to provide data for the environmental impact study to be performed in the future for the Deaf Smith County, Texas site for a nuclear waste repository in salt. This document updates a previous unpublished report to the level of the Site Characterization Plan---Conceptual Design Report SCP-CDR. The previous study identifies the data needs for the Environmental Assessment effort for seven possible salt repository sites. Volume 2 contains tables of source terms

Low Density Supersonic Decelerator (LDSD) Supersonic Flight Dynamics Test (SFDT) Plume Induced Environment Modelling

Science.gov (United States)

Mobley, B. L.; Smith, S. D.; Van Norman, J. W.; Muppidi, S.; Clark, I

2016-01-01

Provide plume induced heating (radiation & convection) predictions in support of the LDSD thermal design (pre-flight SFDT-1) Predict plume induced aerodynamics in support of flight dynamics, to achieve targeted freestream conditions to test supersonic deceleration technologies (post-flight SFDT-1, pre-flight SFDT-2)

Amnioinfusion for relief of recurrent severe and moderate variable decelerations in labor.

Science.gov (United States)

Regi, Annie; Alexander, Nancy; Jose, Ruby; Lionel, Jessie; Varghese, Lilly; Peedicayil, Abraham

2009-05-01

To determine whether intrapartum amnioinfusion (AI) relieves recurrent moderate and severe variable decelerations in laboring women with clear or grade I meconium-stained amniotic fluid and reduces cesarean section rate for fetal distress. A randomized controlled trial was conducted in labor unit of Christian Medical College Hospital, Vellore, India, between October 2003 and September 2004. Women were randomized to receive AI (group I) and not to receive it (group II). A total of 150 women (75 in each group) were included in the study. There was significant relief of variable decelerations in group I and no difference in overall cesarean section rate but significant reduction in cesarean section rate for fetal distress in group I, and significant reduction in cesarean section rate for fetal distress in nulliparous women of group I. Neonatal acidemia was also significantly reduced in the nulliparous women receiving AI. The duration of maternal postpartum hospital stay was significantly reduced in group I. There were no adverse maternal or neonatal outcomes. AI was a beneficial therapeutic intervention in women patients showing fetal distress in first stage of labor, and it reduced cesarean section for fetal distress and neonatal acidemia.

Gingival crevicular fluid volume and periodontal parameters alterations after use of conventional and self-ligating brackets.

Science.gov (United States)

Bergamo, Ana Zn; Nelson-Filho, Paulo; Romano, Fábio L; da Silva, Raquel Ab; Saraiva, Maria Cp; da Silva, Lea Ab; Matsumoto, Mirian An

2016-12-01

The aim of this study was to evaluate the alterations on plaque index (PI), gingival index (GI), gingival bleeding index (GBI), and gingival crevicular fluid (GCF) volume after use of three different brackets types for 60 days. Setting Participants: The sample comprised 20 patients of both sexes aged 11-15 years (mean age: 13.3 years), with permanent dentition, adequate oral hygiene, and mild tooth crowding, overjet, and overbite. A conventional metallic bracket Gemini™, and two different brands of self-ligating brackets - In-Ovation ® R and SmartClip™ - were bonded to the maxillary incisors and canines. PI, GI, GBI scores, and GCF volume were measured before and 30 and 60 days after bonding of the brackets. Data were analysed statistically using non-parametric tests coefficient at a 5% significance level. There was no statistically significant correlation (P > 0.05) between tooth crowding, overjet, and overbite and the PI, GI, GBI scores, and GCF volume before bonding, indicating no influence of malocclusion on the clinical parameters. Regardless of the bracket design, no statistically significant difference (P > 0.05) was found for GI, GBI scores. PI and GCF volume showed a significant difference among the brackets in different periods. In pairwise comparisons a significant difference was observed when compared before with 60 days after bonding, for the teeth bonded with SmartClip™ self-ligating bracket, (PI P = 0.009; GCF volume P = 0.001). There was an increase in PI score and GCF volume 60 days after bonding of SmartClip™ self-ligating brackets, indicating the influence of bracket design on these clinical parameters.

Electron bunch length measurement with a wakefield radiation decelerator

Directory of Open Access Journals (Sweden)

Weiwei Li

2014-03-01

Full Text Available In this paper, we propose a novel method to measure the electron bunch length with a dielectric wakefield radiation (DWR decelerator which is composed of two dielectric-lined waveguides (DLWs and an electron spectrometer. When an electron beam passes through a DLW, the DWR is excited which leads to an energy loss of the electron beam. The energy loss is found to be largely dependent on the electron bunch length and can be easily measured by an electron spectrometer which is essential for a normal accelerator facility. Our study shows that this method has a high resolution and a great simplicity.

Summary of the First High-Altitude, Supersonic Flight Dynamics Test for the Low-Density Supersonic Decelerator Project

Science.gov (United States)

Clark, Ian G.; Adler, Mark; Manning, Rob

2015-01-01

NASA's Low-Density Supersonic Decelerator Project is developing and testing the next generation of supersonic aerodynamic decelerators for planetary entry. A key element of that development is the testing of full-scale articles in conditions relevant to their intended use, primarily the tenuous Mars atmosphere. To achieve this testing, the LDSD project developed a test architecture similar to that used by the Viking Project in the early 1970's for the qualification of their supersonic parachute. A large, helium filled scientific balloon is used to hoist a 4.7 m blunt body test vehicle to an altitude of approximately 32 kilometers. The test vehicle is released from the balloon, spun up for gyroscopic stability, and accelerated to over four times the speed of sound and an altitude of 50 kilometers using a large solid rocket motor. Once at those conditions, the vehicle is despun and the test period begins. The first flight of this architecture occurred on June 28th of 2014. Though primarily a shake out flight of the new test system, the flight was also able to achieve an early test of two of the LDSD technologies, a large 6 m diameter Supersonic Inflatable Aerodynamic Decelerator (SIAD) and a large, 30.5 m nominal diameter supersonic parachute. This paper summarizes this first flight.

Parameters affecting the tidal volume during expiratory abdominal compression in patients with prolonged tracheostomy mechanical ventilation.

Science.gov (United States)

Morino, Akira; Shida, Masahiro; Tanaka, Masashi; Sato, Kimihiro; Seko, Toshiaki; Ito, Shunsuke; Ogawa, Shunichi; Takahashi, Naoaki

2015-07-01

[Purpose] The aim of this study was to clarify physical parameters affecting the tidal volume during expiratory abdominal compression in patients with prolonged tracheostomy mechanical ventilation. [Methods] Eighteen patients with prolonged mechanical ventilation were included in this study. Expiratory abdominal compression was performed on patients lying in a supine position. The abdomen above the navel was vertically compressed in synchronization with expiration and released with inspiration. We measured the tidal volume during expiratory abdominal compression. [Results] The mean tidal volume during expiratory abdominal compression was higher than that at rest (430.6 ± 127.1 mL vs. 344.0 ± 94.3 mL). The tidal volume during expiratory abdominal compression was correlated with weight, days of ventilator support, dynamic compliance and abdominal expansion. Stepwise multiple regression analysis revealed that weight (β = 0.499), dynamic compliance (β = 0.387), and abdominal expansion (β = 0.365) were factors contributing to the tidal volume during expiratory abdominal compression. [Conclusion] Expiratory abdominal compression increased the tidal volume in patients with prolonged tracheostomy mechanical ventilation. The tidal volume during expiratory abdominal compression was influenced by each of the pulmonary conditions and the physical characteristics.

Continuous all-optical deceleration of molecular beams

Science.gov (United States)

Jayich, Andrew; Chen, Gary; Long, Xueping; Wang, Anna; Campbell, Wesley

2014-05-01

A significant impediment to generating ultracold molecules is slowing a molecular beam to velocities where the molecules can be cooled and trapped. We report on progress toward addressing this issue with a general optical deceleration technique for molecular and atomic beams. We propose addressing the molecular beam with a pump and dump pulse sequence from a mode-locked laser. The pump pulse counter-propagates with respect to the beam and drives the molecules to the excited state. The dump pulse co-propagates and stimulates emission, driving the molecules back to the ground state. This cycle transfers 2 ℏk of momentum and can generate very large optical forces, not limited by the spontaneous emission lifetime of the molecule or atom. Importantly, avoiding spontaneous emission limits the branching to dark states. This technique can later be augmented with cooling and trapping. We are working towards demonstrating this optical force by accelerating a cold atomic sample.

Wavelet time-frequency analysis of accelerating and decelerating flows in a tube bank

International Nuclear Information System (INIS)

Indrusiak, M.L.S.; Goulart, J.V.; Olinto, C.R.; Moeller, S.V.

2005-01-01

In the present work, the steady approximation for accelerating and decelerating flows through tube banks is discussed. With this purpose, the experimental study of velocity and pressure fluctuations of transient turbulent cross-flow in a tube bank with square arrangement and a pitch-to-diameter ratio of 1.26 is performed. The Reynolds number at steady-state flow, computed with the tube diameter and the flow velocity in the narrow gap between the tubes, is 8 x 10 4 . Air is the working fluid. The accelerating and decelerating transients are obtained by means of start and stop of the centrifugal blower. Wavelet and wavelet packet multiresolution analysis were applied to decompose the signal in frequency intervals, using Daubechies 20 wavelet and scale functions, thus allowing the analysis of phenomena in a time-frequency domain. The continuous wavelet transform was also applied, using the Morlet function. The signals in the steady state, which presented a bistable behavior, were separated in two modes and analyzed with usual statistic tools. The results were compared with the steady-state assumption, demonstrating the ability of wavelets for analyzing time varying signals

Energy recapture through deceleration - regenerative braking in electric vehicles from a user perspective.

Science.gov (United States)

Cocron, Peter; Bühler, Franziska; Franke, Thomas; Neumann, Isabel; Dielmann, Benno; Krems, Josef F

2013-01-01

We report results from a 1-year field study (N = 80) on user interactions with regenerative braking in electric vehicles. Designed to recapture energy in vehicles with electric powertrains, regenerative braking has an important influence on both the task of driving and energy consumption. Results from user assessments and data from onboard data loggers indicate that most drivers quickly learned to interact with the system, which was triggered via accelerator. Further, conventional braking manoeuvres decreased significantly as the majority of deceleration episodes could only be executed through regenerative braking. Still, some drivers reported difficulties when adapting to the system. These difficulties could be addressed by offering different levels of regeneration so that the intensity of the deceleration could be individually modified. In general, the system is trusted and regarded as a valuable tool for prolonging range. Regenerative braking in electric vehicles has direct implications for the driving task. We found that drivers quickly learn to use and accept a system, which is triggered via accelerator. For those reporting difficulties in the interaction, it appears reasonable to integrate options to customise or switch off the system.

Determining Representative Elementary Volume For Multiple Petrophysical Parameters using a Convex Hull Analysis of Digital Rock Data

Science.gov (United States)

Shah, S.; Gray, F.; Yang, J.; Crawshaw, J.; Boek, E.

2016-12-01

Advances in 3D pore-scale imaging and computational methods have allowed an exceptionally detailed quantitative and qualitative analysis of the fluid flow in complex porous media. A fundamental problem in pore-scale imaging and modelling is how to represent and model the range of scales encountered in porous media, starting from the smallest pore spaces. In this study, a novel method is presented for determining the representative elementary volume (REV) of a rock for several parameters simultaneously. We calculate the two main macroscopic petrophysical parameters, porosity and single-phase permeability, using micro CT imaging and Lattice Boltzmann (LB) simulations for 14 different porous media, including sandpacks, sandstones and carbonates. The concept of the `Convex Hull' is then applied to calculate the REV for both parameters simultaneously using a plot of the area of the convex hull as a function of the sub-volume, capturing the different scales of heterogeneity from the pore-scale imaging. The results also show that the area of the convex hull (for well-chosen parameters such as the log of the permeability and the porosity) decays exponentially with sub-sample size suggesting a computationally efficient way to determine the system size needed to calculate the parameters to high accuracy (small convex hull area). Finally we propose using a characteristic length such as the pore size to choose an efficient absolute voxel size for the numerical rock.

A multiscale analysis of the hotspot dynamics during the deceleration phase of inertial confinement capsules

International Nuclear Information System (INIS)

Garnier, Josselin; Cherfils, Catherine

2005-01-01

This paper is devoted to the study of the deceleration phase of inertial confinement capsules. First the self-similar flow exhibited by Betti et al. [Phys. Plasmas 8, 5257 (2001)] is proved to be an attractor in the sense that arbitrary initial conditions converge towards this solution. The convergence rate depends on the ablation process and heat conductivity and it is shown to be a power law of the increase rate of the hotspot mass. Second the thin layer that separates the hotspot from the cold shell is described and it is shown that it also converges to a locally self-similar profile. By using and generalizing a shell model introduced by Betti et al. [Phys. Plasmas 9, 2277 (2002)] a closed system of ordinary differential equations for the main hydrodynamic variables is derived. Finally the linear growth rates of the deceleration phase Rayleigh-Taylor instabilities are computed taking into account ablation and spherical convergence. Significant differences are exhibited between directly and indirectly driven capsules

Studies of Lear antiproton deceleration: radiofrequency quadripole or synchrotron

International Nuclear Information System (INIS)

Iazzourene, F.

1987-06-01

The aim of this work is to study a radiofrequency quadrupole (RFQ) and a synchrotron as decelerating systems for antiprotons extracted from the Low Energy Antiproton Ring (LEAR) at CERN. Antiprotons at energies lower than those available from LEAR are need by some experiments, eg. the measurement of the mass difference between protons and antiprotons with 10 -9 accuracy, using a Smith and Princeton spectrometer, and the measurement of gravitation on the antiprotons, using a trap. Depending on the LEAR performances, one can conclude that the RFQ is suitable for the experiment on the gravitation, and the synchrotron, owing to its electron cooling system, is a better solution for the experiment on the mass difference measurement, because of the very small acceptance of the spectrometer [fr

Relationship between dose-volume parameters and pulmonary complications after neoadjuvant chemoradiotherapy followed by surgery for lung cancer

Energy Technology Data Exchange (ETDEWEB)

Takahashi, Shigeo; Shibata, Toru [Kagawa University Hospital, Department of Radiation Oncology, Kagawa (Japan); Go, Tetsuhiko; Kasai, Yoshitaka; Yokomise, Hiroyasu [Kagawa University, Department of General Thoracic, Breast and Endocrine Surgery, Faculty of Medicine, Kagawa (Japan)

2016-09-15

This study evaluated the relationship between dose-volume histogram (DVH) parameters and pulmonary complications after neoadjuvant chemoradiotherapy (NACRT) followed by surgery for lung cancer. We also examined a new DVH parameter, because the unresected lung should be more spared than the later resected lung. Data from 43 non-small cell lung cancer patients were retrospectively analyzed. The DVH parameters of the lung were calculated from the total bilateral lung volume minus (1) the gross tumor volume (DVHg) or (2) the later resected lung volume (DVHr). Radiation pneumonitis (RP) and fistula, including bronchopleural and pulmonary fistula, were graded as the pulmonary complications. Factors affecting the incidences of grade 2 or higher RP (≥G2 RP) and fistula were analyzed. Sixteen patients (37 %) experienced ≥G2 RP and a V20 value of the total lung minus the later resected lung (V20r) ≥ 12 % was a significant factor affecting the incidence of ≥G2 RP (p = 0.032). Six patients (14 %) developed a fistula and a V35 value of the total lung minus the gross tumor (V35g) ≥ 19 % and a V40g ≥ 16 % were significant factors affecting the incidence of fistula (p = 0.002 and 0.009, respectively). These DVH parameters may be related to the incidences of ≥G2 RP and fistula. (orig.) [German] In dieser Studie wurde die Beziehung zwischen Dosis-Volumen-Histogramm-(DVH-)Parametern und pulmonalen Komplikationen nach neoadjuvanter Radiochemotherapie (NARCT) und nachfolgender Operation beim Lungenkarzinom untersucht. Zudem wurde ein neuer DVH-Parameter untersucht, da das nichtresezierte Lungengewebe mehr geschont werden sollte als reseziertes Gewebe. Daten von 43 Patienten mit nicht-kleinzelligem Bronchialkarzinom wurden retrospektiv analysiert. Die DVH-Parameter der Lunge wurden aus dem gesamten beidseitigen Lungenvolumen minus (1) das makroskopische Tumorvolumen (DVHg) oder (2) das resezierte Lungenvolumen (DVHr) ermittelt. Strahlenpneumonitis (RP) und Fisteln

C-arm flat detector computed tomography parenchymal blood volume imaging: the nature of parenchymal blood volume parameter and the feasibility of parenchymal blood volume imaging in aneurysmal subarachnoid haemorrhage patients

Energy Technology Data Exchange (ETDEWEB)

Kamran, Mudassar; Byrne, James V. [University of Oxford, Nuffield Department of Surgical Sciences, Oxford (United Kingdom)

2015-09-15

C-arm flat detector computed tomography (FDCT) parenchymal blood volume (PBV) measurements allow assessment of cerebral haemodynamics in the neurointerventional suite. This paper explores the feasibility of C-arm computed tomography (CT) PBV imaging and the relationship between the C-arm CT PBV and the MR-PWI-derived cerebral blood volume (CBV) and cerebral blood flow (CBF) parameters in aneurysmal subarachnoid haemorrhage (SAH) patients developing delayed cerebral ischemia (DCI). Twenty-six patients with DCI following aneurysmal SAH underwent a research C-arm CT PBV scan using a biplane angiography system and contemporaneous MR-PWI scan as part of a prospective study. Quantitative whole-brain atlas-based volume-of-interest analysis in conjunction with Pearson correlation and Bland-Altman tests was performed to explore the agreement between C-arm CT PBV and MR-derived CBV and CBF measurements. All patients received medical management, while eight patients (31 %) underwent selective intra-arterial chemical angioplasty. Colour-coded C-arm CT PBV maps were 91 % sensitive and 100 % specific in detecting the perfusion abnormalities. C-arm CT rPBV demonstrated good agreement and strong correlation with both MR-rCBV and MR-rCBF measurements; the agreement and correlation were stronger for MR-rCBF relative to MR-rCBV and improved for C-arm CT PBV versus the geometric mean of MR-rCBV and MR-rCBF. Analysis of weighted means showed that the C-arm CT PBV has a preferential blood flow weighting (∼60 % blood flow and ∼40 % blood volume weighting). C-arm CT PBV imaging is feasible in DCI following aneurysmal SAH. PBV is a composite perfusion parameter incorporating both blood flow and blood volume weightings. That PBV has preferential (∼60 %) blood flow weighting is an important finding, which is of clinical significance when interpreting the C-arm CT PBV maps, particularly in the setting of acute brain ischemia. (orig.)

C-arm flat detector computed tomography parenchymal blood volume imaging: the nature of parenchymal blood volume parameter and the feasibility of parenchymal blood volume imaging in aneurysmal subarachnoid haemorrhage patients

International Nuclear Information System (INIS)

Kamran, Mudassar; Byrne, James V.

2015-01-01

C-arm flat detector computed tomography (FDCT) parenchymal blood volume (PBV) measurements allow assessment of cerebral haemodynamics in the neurointerventional suite. This paper explores the feasibility of C-arm computed tomography (CT) PBV imaging and the relationship between the C-arm CT PBV and the MR-PWI-derived cerebral blood volume (CBV) and cerebral blood flow (CBF) parameters in aneurysmal subarachnoid haemorrhage (SAH) patients developing delayed cerebral ischemia (DCI). Twenty-six patients with DCI following aneurysmal SAH underwent a research C-arm CT PBV scan using a biplane angiography system and contemporaneous MR-PWI scan as part of a prospective study. Quantitative whole-brain atlas-based volume-of-interest analysis in conjunction with Pearson correlation and Bland-Altman tests was performed to explore the agreement between C-arm CT PBV and MR-derived CBV and CBF measurements. All patients received medical management, while eight patients (31 %) underwent selective intra-arterial chemical angioplasty. Colour-coded C-arm CT PBV maps were 91 % sensitive and 100 % specific in detecting the perfusion abnormalities. C-arm CT rPBV demonstrated good agreement and strong correlation with both MR-rCBV and MR-rCBF measurements; the agreement and correlation were stronger for MR-rCBF relative to MR-rCBV and improved for C-arm CT PBV versus the geometric mean of MR-rCBV and MR-rCBF. Analysis of weighted means showed that the C-arm CT PBV has a preferential blood flow weighting (∼60 % blood flow and ∼40 % blood volume weighting). C-arm CT PBV imaging is feasible in DCI following aneurysmal SAH. PBV is a composite perfusion parameter incorporating both blood flow and blood volume weightings. That PBV has preferential (∼60 %) blood flow weighting is an important finding, which is of clinical significance when interpreting the C-arm CT PBV maps, particularly in the setting of acute brain ischemia. (orig.)

Acceleration{endash}deceleration process of thin foils confined in water and submitted to laser driven shocks

Energy Technology Data Exchange (ETDEWEB)

Romain, J.P.; Auroux, E. [Laboratoire de Combustion et de Detonique (UPR 9028 CNRS), ENSMA, BP 109, Teleport 2, Chasseneuil du Poitou, 86960 Futuroscope Cedex (France)

1997-08-01

An experimental, numerical, and analytical study of the acceleration and deceleration process of thin metallic foils immersed in water and submitted to laser driven shocks is presented. Aluminum and copper foils of 20 to 120 {mu}m thickness, confined on both sides by water, have been irradiated at 1.06 {mu}m wavelength by laser pulses of {approximately}20ns duration, {approximately}17J energy, and {approximately}4GW/cm{sup 2} incident intensity. Time resolved velocity measurements have been made, using an electromagnetic velocity gauge. The recorded velocity profiles reveal an acceleration{endash}deceleration process, with a peak velocity up to 650 m/s. Predicted profiles from numerical simulations reproduce all experimental features, such as wave reverberations, rate of increase and decrease of velocity, peak velocity, effects of nature, and thickness of the foils. A shock pressure of about 2.5 GPa is inferred from the velocity measurements. Experimental points on the evolution of plasma pressure are derived from the measurements of peak velocities. An analytical description of the acceleration{endash}deceleration process, involving multiple shock and release waves reflecting on both sides of the foils, is presented. The space{endash}time diagrams of waves propagation and the successive pressure{endash}particle velocity states are determined, from which theoretical velocity profiles are constructed. All characteristics of experimental records and numerical simulations are well reproduced. The role of foil nature and thickness, in relation with the shock impedance of the materials, appears explicitly. {copyright} {ital 1997 American Institute of Physics.}

Abrupt deceleration of molecular evolution linked to the origin of arborescence in ferns.

Science.gov (United States)

Korall, Petra; Schuettpelz, Eric; Pryer, Kathleen M

2010-09-01

Molecular rate heterogeneity, whereby rates of molecular evolution vary among groups of organisms, is a well-documented phenomenon. Nonetheless, its causes are poorly understood. For animals, generation time is frequently cited because longer-lived species tend to have slower rates of molecular evolution than their shorter-lived counterparts. Although a similar pattern has been uncovered in flowering plants, using proxies such as growth form, the underlying process has remained elusive. Here, we find a deceleration of molecular evolutionary rate to be coupled with the origin of arborescence in ferns. Phylogenetic branch lengths within the “tree fern” clade are considerably shorter than those of closely related lineages, and our analyses demonstrate that this is due to a significant difference in molecular evolutionary rate. Reconstructions reveal that an abrupt rate deceleration coincided with the evolution of the long-lived tree-like habit at the base of the tree fern clade. This suggests that a generation time effect may well be ubiquitous across the green tree of life, and that the search for a responsible mechanism must focus on characteristics shared by all vascular plants. Discriminating among the possibilities will require contributions from various biological disciplines,but will be necessary for a full appreciation of molecular evolution.

Nonlinear wave-beam kinetic equilibrium in decelerating systems

International Nuclear Information System (INIS)

Grishin, V.K.; Shaposhnikova, E.N.

1981-01-01

The equilibrium state of the wave-beam system arising during the interaction of a particle beam and excited electromagnetic wave has been investigated on the basis of the analysis of the exact polution of a non-linear self-consistent linear equation using the complete system of conservation laws. A waveguide with a dielectric filler, into which a monoenergetic particle beam magnetized in a transverse plane is continuously injected, is used as a model of an decelerating system. A dispersion equation describing the system state and expression for the evaluation of efficiency of the beam energy conversion to the field energy have been obtained. It is concluded that larae fields and high efficiency of energy conversion are achieved during the marked beam reconstruction. States with different values of current and beam velocity but similar amplitudes of a longitudinal field are possible in the system considered [ru

Influence of anodization parameters on the volume expansion of anodic aluminum oxide formed in mixed solution of phosphoric and oxalic acids

Science.gov (United States)

Kao, Tzung-Ta; Chang, Yao-Chung

2014-01-01

The growth of anodic alumina oxide was conducted in the mixed solution of phosphoric and oxalic acids. The influence of anodizing voltage, electrolyte temperature, and concentration of phosphoric and oxalic acids on the volume expansion of anodic aluminum oxide has been investigated. Either anodizing parameter is chosen to its full extent of range that allows the anodization process to be conducted without electric breakdown and to explore the highest possible volume expansion factor. The volume expansion factors were found to vary between 1.25 and 1.9 depending on the anodizing parameters. The variation is explained in connection with electric field, ion transport number, temperature effect, concentration, and activity of acids. The formation of anodic porous alumina at anodizing voltage 160 V in 1.1 M phosphoric acid mixed with 0.14 M oxalic acid at 2 °C showed the peak volume expansion factor of 1.9 and the corresponding moderate growth rate of 168 nm/min.

Critical Imperative for the Reform of British Interpretation of Fetal Heart Rate Decelerations: Analysis of FIGO and NICE Guidelines, Post-Truth Foundations, Cognitive Fallacies, Myths and Occam's Razor.

Science.gov (United States)

Sholapurkar, Shashikant L

2017-04-01

Cardiotocography (CTG) has disappointingly failed to show good predictability for fetal acidemia or neonatal outcomes in several large studies. A complete rethink of CTG interpretation will not be out of place. Fetal heart rate (FHR) decelerations are the most common deviations, benign as well as manifestation of impending fetal hypoxemia/acidemia, much more commonly than FHR baseline or variability. Their specific nomenclature is important (center-stage) because it provides the basic concepts and framework on which the complex "pattern recognition" of CTG interpretation by clinicians depends. Unfortunately, the discrimination of FHR decelerations seems to be muddled since the British obstetrics adopted the concept of vast majority of FHR decelerations being "variable" (cord-compression). With proliferation of confusing waveform criteria, "atypical variables" became the commonest cause of suspicious/pathological CTG. However, National Institute for Health and Care Excellence (NICE) (2014) had to disband the "typical" and "atypical" terminology because of flawed classifying criteria. This analytical review makes a strong case that there are major and fundamental framing and confirmation fallacies (not just biases) in interpretation of FHR decelerations by NICE (2014) and International Federation of Gynecology and Obstetrics (FIGO) (2015), probably the biggest in modern medicine. This "post-truth" approach is incompatible with scientific practice. Moreover, it amounts to setting oneself for failure. The inertia to change could be best described as "backfire effect". There is abundant evidence that head-compression (and other non-hypoxic mediators) causes rapid rather than shallow/gradual decelerations. Currently, the vast majority of decelerations are attributed to unproven cord compression underpinned by flawed disproven pathophysiological hypotheses. Their further discrimination based on abstract, random, trial and error criteria remains unresolved suggesting a

Slowing and cooling of heavy or light (even with a tiny electric dipole moment) polar molecules using a novel, versatile electrostatic Stark decelerator.

Science.gov (United States)

Wang, Qin; Hou, Shunyong; Xu, Liang; Yin, Jianping

2016-02-21

To meet some demands for realizing precise measurements of an electric dipole moment of electron (eEDM) and examining cold collisions or cold chemical physics, we have proposed a novel, versatile electrostatic Stark decelerator with an array of true 3D electric potential wells, which are created by a series of horizontally-oriented, U-shaped electrodes with time-sequence controlling high voltages (± HV) and two guiding electrodes with a constant voltage. We have calculated the 2D electric field distribution, the Stark shifts of the four lowest rotational sub-levels of PbF molecules in the X1(2)Π1/2(v = 0) electronic and vibrational ground states as well as the population in the different rotational levels. We have discussed the 2D longitudinal and transverse phase-space acceptances of PbF molecules in our decelerator. Subsequently, we have simulated the dynamic processes of the decelerated PbF molecules using the 3D Monte-Carlo method, and have found that a supersonic PbF beam with a velocity of 300 m s(-1) can be efficiently slowed to about 5 m s(-1), which will greatly enhance the sensitivities to research a parity violation and measure an eEDM. In addition, we have investigated the dependences of the longitudinal velocity spread, longitudinal temperature and bunching efficiency on both the number of guiding stages and high voltages, and found that after bunching, a cold packet of PbF molecules in the J = 7/2, MΩ = -7/4 state with a longitudinal velocity spread of 0.69 m s(-1) (corresponding to a longitudinal temperature of 2.35 mK) will be produced by our high-efficient decelerator, which will generate a high energy-resolution molecular beam for studying cold collision physics. Finally, our novel decelerator can also be used to efficiently slow NO molecules with a tiny electric dipole moment (EDM) of 0.16 D from 315 m s(-1) to 28 m s(-1). It is clear that our proposed new decelerator has a good slowing performance and experimental feasibility as well as wide

Ablation and deceleration of mass-driver launched projectiles for space disposal of nuclear wastes

International Nuclear Information System (INIS)

Park, C.; Bowen, S.W.

1981-01-01

The energy cost of launching a projectile containing nuclear waste is two orders of magnitude lower with a mass driver than with a typical rocket system. A mass driver scheme will be feasible, however, only if ablation and deceleration are within certain tolerable limits. It is shown that if a hemisphere-cylinder-shaped projectile protected thermally with a graphite nose is launched vertically to attain a velocity of 17 km/sec at an altitude of 40 km, the mass loss from ablation during atmospheric flight will be less than 0.1 ton, provided the radius of the projectile is under 20 cm and the projectile's mass is of the order of 1 ton. The velocity loss from drag will vary from 0.4 to 30 km/sec, depending on the mass and radius of the projectile, the smaller velocity loss corresponding to large mass and small radius. Ablation is always within a tolerable range for schemes using a mass driver launcher to dispose of nuclear wastes outside the solar system. Deceleration can also be held in the tolerable range if the mass and diameter of the projectile are properly chosen

Finite Atwood Number Effects on Deceleration-Phase Instability in Room-Temperature Direct-Drive Implosions

Science.gov (United States)

Miller, S.; Knauer, J. P.; Radha, P. B.; Goncharov, V. N.

2017-10-01

Performance degradation in direct-drive inertial confinement fusion implosions can be caused by several effects, one of which is Rayleigh-Taylor (RT) instability growth during the deceleration phase. In room-temperature plastic target implosions, this deceleration-phase RT growth is enhanced by the density discontinuity and finite Atwood numbers at the fuel-pusher interface. For the first time, an experimental campaign at the Omega Laser Facility systematically varied the ratio of deuterium-to-tritium (D-to-T) within the DT gas fill to change the Atwood number. The goal of the experiment was to understand the effects of Atwood number variation on observables like apparent ion temperature, yield, and variations in areal density and bulk fluid motion, which lead to broadening of neutron spectra along different lines of sight. Simulations by the hydrodynamic codes LILAC and DRACO were used to study growth rates for different D-to-T ratios and identify observable quantities effected by Atwood number variation. Results from simulations and the experiment are presented. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

Preliminary performance assessment for the Waste Isolation Pilot Plant, December 1992. Volume 3, Model parameters: Sandia WIPP Project

Energy Technology Data Exchange (ETDEWEB)

1992-12-29

This volume documents model parameters chosen as of July 1992 that were used by the Performance Assessment Department of Sandia National Laboratories in its 1992 preliminary performance assessment of the Waste Isolation Pilot Plant (WIPP). Ranges and distributions for about 300 modeling parameters in the current secondary data base are presented in tables for the geologic and engineered barriers, global materials (e.g., fluid properties), and agents that act upon the WIPP disposal system such as climate variability and human-intrusion boreholes. The 49 parameters sampled in the 1992 Preliminary Performance Assessment are given special emphasis with tables and graphics that provide insight and sources of data for each parameter.

Improved dose–volume histogram estimates for radiopharmaceutical therapy by optimizing quantitative SPECT reconstruction parameters

International Nuclear Information System (INIS)

Cheng Lishui; Hobbs, Robert F; Sgouros, George; Frey, Eric C; Segars, Paul W

2013-01-01

smoothing at early time points post-radiopharmaceutical administration but more smoothing and fewer iterations at later time points when the total organ activity was lower. The results of this study demonstrate the importance of using optimal reconstruction and regularization parameters. Optimal results were obtained with different parameters at each time point, but using a single set of parameters for all time points produced near-optimal dose–volume histograms. (paper)

Improved dose-volume histogram estimates for radiopharmaceutical therapy by optimizing quantitative SPECT reconstruction parameters

Science.gov (United States)

Cheng, Lishui; Hobbs, Robert F.; Segars, Paul W.; Sgouros, George; Frey, Eric C.

2013-06-01

smoothing at early time points post-radiopharmaceutical administration but more smoothing and fewer iterations at later time points when the total organ activity was lower. The results of this study demonstrate the importance of using optimal reconstruction and regularization parameters. Optimal results were obtained with different parameters at each time point, but using a single set of parameters for all time points produced near-optimal dose-volume histograms.

Investigation Of The Effects Of Reflow Profile Parameters On Lead-free Solder Bump Volumes And Joint Integrity

Science.gov (United States)

Amalu, E. H.; Lui, Y. T.; Ekere, N. N.; Bhatti, R. S.; Takyi, G.

2011-01-01

The electronics manufacturing industry was quick to adopt and use the Surface Mount Technology (SMT) assembly technique on realization of its huge potentials in achieving smaller, lighter and low cost product implementations. Increasing global customer demand for miniaturized electronic products is a key driver in the design, development and wide application of high-density area array package format. Electronic components and their associated solder joints have reduced in size as the miniaturization trend in packaging continues to be challenged by printing through very small stencil apertures required for fine pitch flip-chip applications. At very narrow aperture sizes, solder paste rheology becomes crucial for consistent paste withdrawal. The deposition of consistent volume of solder from pad-to-pad is fundamental to minimizing surface mount assembly defects. This study investigates the relationship between volume of solder paste deposit (VSPD) and the volume of solder bump formed (VSBF) after reflow, and the effect of reflow profile parameters on lead-free solder bump formation and the associated solder joint integrity. The study uses a fractional factorial design (FFD) of 24-1 Ramp-Soak-Spike reflow profile, with all main effects and two-way interactions estimable to determine the optimal factorial combination. The results from the study show that the percentage change in the VSPD depends on the combination of the process parameters and reliability issues could become critical as the size of solder joints soldered on the same board assembly vary greatly. Mathematical models describe the relationships among VSPD, VSBF and theoretical volume of solder paste. Some factors have main effects across the volumes and a number of interactions exist among them. These results would be useful for R&D personnel in designing and implementing newer applications with finer-pitch interconnect.

Changes of deceleration and acceleration capacity of heart rate in patients with acute hemispheric ischemic stroke

Directory of Open Access Journals (Sweden)

Xu YH

2016-03-01

Full Text Available Yan-Hong Xu,1 Xing-De Wang,2 Jia-Jun Yang,1 Li Zhou,2 Yong-Chao Pan1 1Department of Neurology, 2Department of Cardiology, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, People’s Republic of China Background and purpose: Autonomic dysfunction is common after stroke, which is correlated with unfavorable outcome. Phase-rectified signal averaging is a newly developed technique for assessing cardiac autonomic function, by detecting sympathetic and vagal nerve activity separately through calculating acceleration capacity (AC and deceleration capacity (DC of heart rate. In this study, we used this technique for the first time to investigate the cardiac autonomic function of patients with acute hemispheric ischemic stroke. Methods: A 24-hour Holter monitoring was performed in 63 patients with first-ever acute ischemic stroke in hemisphere and sinus rhythm, as well as in 50 controls with high risk of stroke. DC, AC, heart rate variability parameters, standard deviation of all normal-to-normal intervals (SDNN, and square root of the mean of the sum of the squares of differences between adjacent normal-to-normal intervals (RMSSD were calculated. The National Institutes of Health Stroke Scale (NIHSS was used to assess the severity of stroke. We analyzed the changes of DC, AC, SDNN, and RMSSD and also studied the correlations between these parameters and NIHSS scores. Results: The R–R (R wave to R wave on electrocardiogram intervals, DC, AC, and SDNN in the cerebral infarction group were lower than those in controls (P=0.003, P=0.002, P=0.006, and P=0.043, but the difference of RMSSD and the D-value and ratio between absolute value of AC (|AC| and DC were not statistically significant compared with those in controls. The DC of the infarction group was significantly correlated with |AC|, SDNN, and RMSSD (r=0.857, r=0.619, and r=0.358; P=0.000, P=0.000, and P=0.004. Correlation analysis also showed that DC, |AC|, and SDNN

Deceleration project bursts out of the starting-blocks

CERN Multimedia

Anaïs Schaeffer

2011-01-01

The starter's pistol was fired for the ELENA project on 28 September, with the kick-off meeting organised in collaboration with the Antiproton Decelerator Users Committee. With more than 90 scientists in attendance from 20 research centres throughout the world expressing their enthusiasm for the project…and some even more than that... the meeting was a great success.   "Our kick-off meeting was a really great success," says Stéphan Maury of the Beams (BE) Department, who is responsible for the ELENA (Extra Low ENergy Antiproton ring) project. PH Department's Walter Oelert, Chairman of the AD Users Committee and one of the instigators of the project, adds: "More than 90 participants showed up, over twice the number we were expecting! They were all very enthusiastic and eager to get ELENA off the ground." The meeting was attended by representatives of some twenty institutes from across the globe, all of whom had come to bl...

Testing backreaction effects with observational Hubble parameter data

Science.gov (United States)

Cao, Shu-Lei; Teng, Huan-Yu; Wan, Hao-Yi; Yu, Hao-Ran; Zhang, Tong-Jie

2018-02-01

The spatially averaged inhomogeneous Universe includes a kinematical backreaction term Q_{D} that is relate to the averaged spatial Ricci scalar _{D} in the framework of general relativity. Under the assumption that Q_{D} and _{D} obey the scaling laws of the volume scale factor a_{D}, a direct coupling between them with a scaling index n is remarkable. In order to explore the generic properties of a backreaction model for explaining the accelerated expansion of the Universe, we exploit two metrics to describe the late time Universe. Since the standard FLRW metric cannot precisely describe the late time Universe on small scales, the template metric with an evolving curvature parameter κ _{D}(t) is employed. However, we doubt the validity of the prescription for κ _{D}, which motivates us apply observational Hubble parameter data (OHD) to constrain parameters in dust cosmology. First, for FLRW metric, by getting best-fit constraints of Ω^{D_0}_m = 0.25^{+0.03}_{-0.03}, n = 0.02^{+0.69}_{-0.66}, and H_{D_0} = 70.54^{+4.24}_{-3.97} km s^{-1 Mpc^{-1}}, the evolutions of parameters are explored. Second, in template metric context, by marginalizing over H_{D_0} as a prior of uniform distribution, we obtain the best-fit values of n=-1.22^{+0.68}_{-0.41} and Ωm^{D0}=0.12^{+0.04}_{-0.02}. Moreover, we utilize three different Gaussian priors of H_{D_0}, which result in different best-fits of n, but almost the same best-fit value of Ωm^{D0}˜ 0.12. Also, the absolute constraints without marginalization of parameter are obtained: n=-1.1^{+0.58}_{-0.50} and Ωm^{D0}=0.13± 0.03. With these constraints, the evolutions of the effective deceleration parameter q^{D} indicate that the backreaction can account for the accelerated expansion of the Universe without involving extra dark energy component in the scaling solution context. Nevertheless, the results also verify that the prescription of κ _{D} is insufficient and should be improved.

Ion deceleration in interpenetrating plasma jets

International Nuclear Information System (INIS)

Renner, O.; Krousky, E.; Larroche, O.; Liska, R.

2010-01-01

Complete text of publication follows. Inertial and magnetic confinement fusion schemes involve collisions of high-temperature plasma jets and their interaction with solid surfaces (the so-called plasma-wall interaction, PWI). A fundamental understanding of the PWI effects requires a detailed characterization of the transient collisional phenomena occurring in the interaction region. In this paper we discuss a PWI experiment with double-foil Al/Mg targets fielded at the PALS laser system. An energetic plasma jet was created at the rear (non-irradiated) side of the 0.8-μm-thick Al foil exploded by the main laser beam (50-200 J, 0.44/1.315 μm, 0.25-0.3 ns, 16 W/cm 2 ). This plasma jet streamed towards the 2-μm-thick Mg foil, where the secondary plasma was created either by an auxiliary 5 J laser beam or by the main laser radiation transmitted through the Al foil, together with radiation and particles emitted from the Al foil. The environmental conditions in the plasma were diagnosed by means of high-resolution x-ray spectroscopy and temporally-resolved x-ray imaging. For the first time, the deceleration of the incident Al ions in the near-wall region was directly observed and quantitatively characterized from the Doppler shift of the J-satellite from the Al Lyα spectral group. The interaction scenario was numerically modeled by two concerted codes, namely, i) the Prague Arbitrary Lagrangian Eulerian 2-D code PALE, which solves the Lagrangian mesh distortions by smoothing and conservative remapping of conserved quantities, and ii) the multispecies 1.5-D code MULTIF which models the hydrodynamics of an arbitrary number of interpenetrating ion species in a single space dimension while assuming self-similar plasma expansion in the other directions, and taking into account detailed Coulombian collisional processes. PALE was used to model two counter-streaming Al/Mg plasma plumes until the beginning of their interaction, and the resulting plasma state was then used as

Mean nuclear volume

DEFF Research Database (Denmark)

Mogensen, O.; Sørensen, Flemming Brandt; Bichel, P.

1999-01-01

We evaluated the following nine parameters with respect to their prognostic value in females with endometrial cancer: four stereologic parameters [mean nuclear volume (MNV), nuclear volume fraction, nuclear index and mitotic index], the immunohistochemical expression of cancer antigen (CA125...

ASSOCIATION OF DRUSEN VOLUME WITH CHOROIDAL PARAMETERS IN NONNEOVASCULAR AGE-RELATED MACULAR DEGENERATION.

Science.gov (United States)

Balasubramanian, Siva; Lei, Jianqin; Nittala, Muneeswar G; Velaga, Swetha B; Haines, Jonathan; Pericak-Vance, Margaret A; Stambolian, Dwight; Sadda, SriniVas R

2017-10-01

The choroid is thought to be relevant to the pathogenesis of nonneovascular age-related macular degeneration, but its role has not yet been fully defined. In this study, we evaluate the relationship between the extent of macular drusen and specific choroidal parameters, including thickness and intensity. Spectral domain optical coherence tomography images were collected from two distinct, independent cohorts with nonneovascular age-related macular degeneration: Amish (53 eyes of 34 subjects) and non-Amish (40 eyes from 26 subjects). All spectral domain optical coherence tomography scans were obtained using the Cirrus HD-OCT with a 512 × 128 macular cube (6 × 6 mm) protocol. The Cirrus advanced retinal pigment epithelium analysis tool was used to automatically compute drusen volume within 3 mm (DV3) and 5 mm (DV5) circles centered on the fovea. The inner and outer borders of the choroid were manually segmented, and the mean choroidal thickness and choroidal intensity (i.e., brightness) were calculated. The choroidal intensity was normalized against the vitreous and nerve fiber layer reflectivity. The correlation between DV and these choroidal parameters was assessed using Pearson and linear regression analysis. A significant positive correlation was observed between normalized choroidal intensity and DV5 in the Amish (r = 0.42, P = 0.002) and non-Amish (r = 0.33, P = 0.03) cohorts. Also, DV3 showed a significant positive correlation with normalized choroidal intensity in both the groups (Amish: r = 0.30, P = 0.02; non-Amish: r = 0.32, P = 0.04). Choroidal thickness was negatively correlated with normalized choroidal intensity in both Amish (r = -0.71, P = 0.001) and non-Amish (r = -0.43, P = 0.01) groups. Normalized choroidal intensity was the most significant constant predictor of DV in both the Amish and non-Amish groups. Choroidal intensity, but not choroidal thickness, seems to be associated with drusen volume in Amish and non-Amish populations. These

H0, q0 and the local velocity field. [Hubble and deceleration constants in Big Bang expansion

Science.gov (United States)

Sandage, A.; Tammann, G. A.

1982-01-01

An attempt is made to find a systematic deviation from linearity for distances that are under the control of the Virgo cluster, and to determine the value of the mean random motion about the systematic flow, in order to improve the measurement of the Hubble and the deceleration constants. The velocity-distance relation for large and intermediate distances is studied, and type I supernovae are calibrated relatively as distance indicators and absolutely to obtain a new value for the Hubble constant. Methods of determining the deceleration constant are assessed, including determination from direct measurement, mean luminosity density, virgocentric motion, and the time scale test. The very local velocity field is investigated, and a solution is preferred with a random peculiar radial velocity of very nearby field galaxies of 90-100 km/s, and a Virgocentric motion of the local group of 220 km/s, leading to an underlying expansion rate of 55, in satisfactory agreement with the global value.

Critical Imperative for the Reform of British Interpretation of Fetal Heart Rate Decelerations: Analysis of FIGO and NICE Guidelines, Post-Truth Foundations, Cognitive Fallacies, Myths and Occam’s Razor

Science.gov (United States)

Sholapurkar, Shashikant L.

2017-01-01

Cardiotocography (CTG) has disappointingly failed to show good predictability for fetal acidemia or neonatal outcomes in several large studies. A complete rethink of CTG interpretation will not be out of place. Fetal heart rate (FHR) decelerations are the most common deviations, benign as well as manifestation of impending fetal hypoxemia/acidemia, much more commonly than FHR baseline or variability. Their specific nomenclature is important (center-stage) because it provides the basic concepts and framework on which the complex “pattern recognition” of CTG interpretation by clinicians depends. Unfortunately, the discrimination of FHR decelerations seems to be muddled since the British obstetrics adopted the concept of vast majority of FHR decelerations being “variable” (cord-compression). With proliferation of confusing waveform criteria, “atypical variables” became the commonest cause of suspicious/pathological CTG. However, National Institute for Health and Care Excellence (NICE) (2014) had to disband the “typical” and “atypical” terminology because of flawed classifying criteria. This analytical review makes a strong case that there are major and fundamental framing and confirmation fallacies (not just biases) in interpretation of FHR decelerations by NICE (2014) and International Federation of Gynecology and Obstetrics (FIGO) (2015), probably the biggest in modern medicine. This “post-truth” approach is incompatible with scientific practice. Moreover, it amounts to setting oneself for failure. The inertia to change could be best described as “backfire effect”. There is abundant evidence that head-compression (and other non-hypoxic mediators) causes rapid rather than shallow/gradual decelerations. Currently, the vast majority of decelerations are attributed to unproven cord compression underpinned by flawed disproven pathophysiological hypotheses. Their further discrimination based on abstract, random, trial and error criteria remains

Prognostic value of pretreatment volume-based quantitative 18F-FDG PET/CT parameters in patients with malignant pleural mesothelioma

International Nuclear Information System (INIS)

Kitajima, Kazuhiro; Doi, Hiroshi; Kuribayashi, Kozo; Hashimoto, Masaki; Tsuchitani, Tatsuya; Tanooka, Masao; Fukushima, Kazuhito; Nakano, Takashi; Hasegawa, Seiki; Hirota, Shozo

2017-01-01

Purpose: To investigate the relationships between pretreatment volume-based quantitative 18 F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) parameters and overall survival (OS) in patients with malignant pleural mesothelioma (MPM). Materials and methods: We retrospectively reviewed data from 201 MPM patients, of whom 38 underwent surgical resection, and calculated the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG), including primary tumors and nodal or distant metastatic lesions, on pretreatment 18 F-FDG PET/CT. Relationships between clinicopathological factors (age, sex, performance status, European Organization for Research and Treatment of Cancer [EORTC] score, histological subtype, TNM stage, and treatment strategy), volume-based quantitative PET/CT parameters, and OS were evaluated using a Cox proportional hazards model and log-rank test. Results: The median follow-up was 15 months (range, 1–96 months; median, 17 months). In a univariate analysis of all patients, older age (p < 0.05), high EORTC score (p < 0.001), non-epithelioid histological subtype (p < 0.001), high T stage (p < 0.001), positive N/M status (p < 0.05, p < 0.001), advanced TNM stage (p < 0.001), non-surgical treatment (p < 0.001), and high SUVmax (p < 0.001), MTV (p < 0.001), or TLG (p < 0.001) were associated with significantly shorter OS. A multivariate analysis confirmed non-epithelioid subtype (hazard ratio [HR]: 1.69, 95% confidence interval [CI]: 1.14–2.48; p < 0.05), non-surgical treatment (HR: 0.58, 95% CI: 0.34–0.95; p < 0.05), and high TLG (HR: 1.97, 95% CI: 1.14–3.44; p < 0.05) as independent negative predictors. Conclusions: Pretreatment volume-based quantitative 18 F-FDG PET/CT parameters, especially TLG, could serve as potential surrogate markers for MPM prognosis.

High-dose preoperative chemoradiotherapy in esophageal cancer patients does not increase postoperative pulmonary complications: Correlation with dose-volume histogram parameters

International Nuclear Information System (INIS)

Hurmuzlu, Meysan; Ovrebo, Kjell; Wentzel-Larsen, Tore; Muren, Ludvig Paul; Viste, Asgaut; Smaaland, Rune

2010-01-01

Purpose: To investigate the association of high-dose preoperative chemoradiotherapy (CRT) and dose-volume histogram (DVH) parameters of lungs with incidence of postoperative pulmonary complications and to identify predictive clinical factors of pulmonary complications. Methods: Data of 65 patients were collected retrospectively. Thirty-five patients underwent transthoracic esophagectomy (TTE) alone and 30 received cisplatin and 5-fluorouracil, concomitant with radiotherapy, median dose 66 Gy, and followed by TTE. From the DVH for each lung alone and for both lungs together as one organ we generated total lung volume, mean radiotherapy dose, relative and absolute volumes receiving more than a threshold dose, and relative and absolute volumes receiving less than a threshold dose. Postoperative pulmonary complications were defined as pneumonia or respiratory failure. Results: Sixty percent of the patients in the TTE alone group had postoperative pulmonary complications versus 63% in the CRT + TTE group. Postoperative mortality was 8.6% and 16.7% in the respective patient groups (p = NS). None of the DVH parameters was associated with postoperative pulmonary complications. Squamous cell carcinoma was an adverse factor related to increased postoperative pulmonary complications. Conclusion: High-dose preoperative CRT was not associated with increased postoperative pulmonary complications in this cohort of esophageal cancer patients.

You are how you eat : Decelerated eating may protect from obesity and eating disorders

OpenAIRE

Zandian, Modjtaba

2009-01-01

On a new framework for anorexia nervosa, learning to eat is central intervention; as patients regain a normal pattern of eating their problems dissolve. Mandometer®, a development of previous methods, allows simultaneous recording of eating rate and the development of satiety as well as experimental manipulation of eating rate. By measuring eating behavior during the course of a meal with this method, women were divided into those eating at a decelerated rate and those eatin...

Whole-body γ-irradiation decelerates rat hepatocyte polyploidization.

Science.gov (United States)

Ikhtiar, Adnan M

2015-07-01

To characterize hepatocyte polyploidization induced by intermediate dose of γ-ray. Male Wistar strain rats were whole-body irradiated (WBI) with 2 Gy of γ-ray at the age of 1 month, and 5-6 rats were sacrificed monthly at 0-25 months after irradiation. The nuclear DNA content of individual hepatocytes was measured by flow cytometry, then hepatocytes were classified into various ploidy classes. Survival percentage, after exposure up to the end of the study, did not indicate any differences between the irradiated groups and controls. The degree of polyploidization in hepatocytes of irradiated rats, was significantly lower than that for the control after 1 month of exposure, and it continued to be lower after up to 8 months. Thereafter, the degree of polyploidization in the irradiated group slowly returned to the control level when the irradiated rats reached the age of 10 months. Intermediate dose of ionizing radiation, in contrast to high doses, decelerate hepatocyte polyploidization, which may coincides with the hypothesis of the beneficial effects of low doses of ionizing radiation.

Tumor response parameters for head and neck cancer derived from tumor-volume variation during radiation therapy

International Nuclear Information System (INIS)

Chvetsov, Alexei V.

2013-01-01

-and-neck squamous cell carcinoma (SCC) is equal to 3.8 mean potential doubling times, which agrees with 4.0 mean potential doubling times obtained previously for lung SCC. Conclusions: The distribution of cell survival fractions obtained in this study support the hypothesis that the tumor-volume variation during radiotherapy treatment for head and neck cancer can be described by the two-level cell population tumor-volume model. This model can be used for in vivo evaluation of patient-specific radiobiological parameters that are needed for tumor-control probability evaluation.

Inter- and intra-rater reproducibility of semiautomatic determination of volume parameters in cardiac magnetic resonance imaging

International Nuclear Information System (INIS)

Trieb, Thomas; Glodny, Bernhard; Scheiblhofer, Martin; Wolf, Christian; Metzler, Bernhard; Pachinger, Otmar; Jaschke, Werner R.; Schocke, Michael F.H.

2008-01-01

Purpose: The purpose of this study was to evaluate inter- and intra-rater reproducibility in volume assessment using cardiac magnetic resonance imaging (CMRI). Methods: Twenty-five healthy volunteers and 106 patients were included into this retrospective study and received CMRI. The patients were divided in three groups (group I, 80 patients with arrhythmia; group II, 20 patients with cardiomyopathy; group III, 6 patients after correction of septum defects). Therefore, the images were semiautomatically segmented by an experienced and an unexperienced radiologists. The analysis of end-diastolic volume (EDV), end-systolic volume (ESV) and stroke volume (SV) as well as ejection fraction (EF) and myocardial mass (MM) were performed twice by an experienced and an unexperienced radiologists. The intra-class correlation coefficients (ICC) were determined for the evaluation of inter- and intra-rater variance. Results: The intra-rater reproducibility for determination of EF, ESV, EDV and MM was excellent with ICCs ranging from 0.88 to 0.99 (all p < 0.001). The inter-observer reproducibility for these parameters was also excellent with ICCs ranging from 0.91 to 0.98 (all p < 0.001). The assessment of the SV showed an excellent intra-rater agreement with ICCs of 0.96 and 0.92 (both p < 0.001), but only a moderate ICC for the inter-rater reproducibility (0.54, p < 0.001). Conclusions: Our study shows that assessment of cardiac volumes can be performed on CMRIs with an excellent reproducibility by both experienced and unexperienced investigators

X-ray pulsars: accretion flow deceleration

International Nuclear Information System (INIS)

Miller, G.S.

1987-01-01

X-ray pulsars are thought to be neutron stars that derive the energy for their x-ray emission by accreting material onto their magnetic polar caps. The accreting material and the x-ray pulsar atmospheres were idealized as fully ionized plasmas consisting only of electrons and protons. A high magnetic field (∼ 5 x 10 12 Gauss) permeates the atmospheric plasma, and causes the motion of atmospheric electrons perpendicular to the field to be quantized into discrete Landau levels. All atmospheric electrons initially lie in the Landau ground state, but in the author's calculations of Coulomb collisions between atmospheric electrons and accreting protons, he allows for processes that leave the electrons in the first excited Landau level. He also considers interactions between accreting protons and the collective modes of the atmospheric plasma. Division of the electromagnetic interaction of a fast proton with a magnetized plasma into single particle and collective effects is described in detail in Chapter 2. Deceleration of the accretion flow due to Coulomb collisions with atmospheric electrons and collective plasma effects was studied in a number of computer simulations. These simulations, along with a discussion of the physical state of the atmospheric plasma and its interactions with a past proton, are presented in Chapter 3. Details of the atmospheric model and a description of the results of the simulations are given in Chapter 4. Chapter 5 contains some brief concluding remarks, and some thoughts on future research

Kinetic parameters of nitridation of molybdenum and niobium alloys with various structure states

International Nuclear Information System (INIS)

Solodkin, G.A.; Bulgach, A.A.; Likhacheva, T.E.

1985-01-01

Effect of preliminary plastic strain under rolling on kinetic parameters of nitridation of VN-2AEh, VN-3 niobium alloys and molybdenum alloy with hafnium is investigated. Extreme character of dependence of kinetic parameters of nitridation on the degree of reduction under rolling is determined. Preliminary plastic strain at negligible reduction is shown to accelerate growth of the zone of internal nitridation and decelerates growth of the nitride zone. Nitrogen atom removal from the surface to the centre is retarded at the increase of the degree of reduction up to 50% and higher. The degree of deformations is the higher the lower nitridation temperature is

ON THE ORIGIN OF FANAROFF-RILEY CLASSIFICATION OF RADIO GALAXIES: DECELERATION OF SUPERSONIC RADIO LOBES

International Nuclear Information System (INIS)

Kawakatu, Nozomu; Kino, Motoki; Nagai, Hiroshi

2009-01-01

We argue that the origin of 'FRI/FRII dichotomy' - the division between Fanaroff-Riley class I (FRI) with subsonic lobes and class II (FRII) radio sources with supersonic lobes is sharp in the radio-optical luminosity plane (Owen-White diagram) - can be explained by the deceleration of advancing radio lobes. The deceleration is caused by the growth of the effective cross-sectional area of radio lobes. We derive the condition in which an initially supersonic lobe turns into a subsonic lobe, combining the ram pressure equilibrium between the hot spots and the ambient medium with the relation between 'the hot spot radius' and 'the linear size of radio sources' obtained from the radio observations. We find that the dividing line between the supersonic lobes and subsonic ones is determined by the ratio of the jet power L j to the number density of the ambient matter at the core radius of the host galaxy n-bar a . It is also found that the maximal ratio of (L j ,n-bar a ) exists and its value resides in (L j ,n-bar a ) max ∼10 44-47 er s -1 cm 3 , taking into account considerable uncertainties. This suggests that the maximal value (L j ,n-bar a ) max separates between FRIs and FRIIs.

Effect of preload reduction by hemodialysis on left atrial volume and echocardiographic Doppler parameters in patients with end-stage renal disease.

Science.gov (United States)

Barberato, Silvio H; Mantilla, Diego E V; Misocami, M Arcio; Gonçalves, Simone M; Bignelli, Alexandre T; Riella, Miguel C; Pecoits-Filho, Roberto

2004-11-01

Left atrial (LA) volume has been proposed as a less preload-dependent parameter of diastolic function than Doppler mitral inflow. We hypothesize that in the absence of mitral regurgitation and atrial fibrilation, LA enlargement could be a more practical (and relatively preload-independent) method for the evaluation of left ventricular diastolic function. The aim of the present study was to determine the effects of preload reduction by hemodialysis on LA volume.

Prognostic value of pretreatment volume-based quantitative {sup 18}F-FDG PET/CT parameters in patients with malignant pleural mesothelioma

Energy Technology Data Exchange (ETDEWEB)

Kitajima, Kazuhiro, E-mail: kitajima@med.kobe-u.ac.jp [Division of Nuclear Medicine and PET Center, Department of Radiology, Hyogo College of Medicine, Hyogo (Japan); Doi, Hiroshi, E-mail: h-doi@hyo-med.ac.jp [Department of Radiology, Hyogo College of Medicine, Hyogo (Japan); Kuribayashi, Kozo, E-mail: kuririn@hyo-med.ac.jp [Division of Respiratory Medicine, Department of Internal Medicine, Hyogo College of Medicine, Hyogo (Japan); Hashimoto, Masaki, E-mail: kogekogemasaki@gmail.com [Department of Thoracic Surgery, Hyogo College of Medicine, Hyogo (Japan); Tsuchitani, Tatsuya, E-mail: tty-823@hyo-med.ac.jp [Department of Radiological Technology, Hyogo College of Medicine College Hospital, Hyogo (Japan); Tanooka, Masao, E-mail: masao1108@gmail.com [Department of Radiological Technology, Hyogo College of Medicine College Hospital, Hyogo (Japan); Fukushima, Kazuhito, E-mail: fukuchan00106@gmail.com [Division of Nuclear Medicine and PET Center, Department of Radiology, Hyogo College of Medicine, Hyogo (Japan); Nakano, Takashi, E-mail: t-nakano@hyo-med.ac.jp [Division of Respiratory Medicine, Department of Internal Medicine, Hyogo College of Medicine, Hyogo (Japan); Hasegawa, Seiki, E-mail: hasegawa@hyo-med.ac.jp [Department of Thoracic Surgery, Hyogo College of Medicine, Hyogo (Japan); Hirota, Shozo, E-mail: hirota-s@hyo-med.ac.jp [Department of Radiology, Hyogo College of Medicine, Hyogo (Japan)

2017-01-15

Purpose: To investigate the relationships between pretreatment volume-based quantitative {sup 18}F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) parameters and overall survival (OS) in patients with malignant pleural mesothelioma (MPM). Materials and methods: We retrospectively reviewed data from 201 MPM patients, of whom 38 underwent surgical resection, and calculated the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG), including primary tumors and nodal or distant metastatic lesions, on pretreatment {sup 18}F-FDG PET/CT. Relationships between clinicopathological factors (age, sex, performance status, European Organization for Research and Treatment of Cancer [EORTC] score, histological subtype, TNM stage, and treatment strategy), volume-based quantitative PET/CT parameters, and OS were evaluated using a Cox proportional hazards model and log-rank test. Results: The median follow-up was 15 months (range, 1–96 months; median, 17 months). In a univariate analysis of all patients, older age (p < 0.05), high EORTC score (p < 0.001), non-epithelioid histological subtype (p < 0.001), high T stage (p < 0.001), positive N/M status (p < 0.05, p < 0.001), advanced TNM stage (p < 0.001), non-surgical treatment (p < 0.001), and high SUVmax (p < 0.001), MTV (p < 0.001), or TLG (p < 0.001) were associated with significantly shorter OS. A multivariate analysis confirmed non-epithelioid subtype (hazard ratio [HR]: 1.69, 95% confidence interval [CI]: 1.14–2.48; p < 0.05), non-surgical treatment (HR: 0.58, 95% CI: 0.34–0.95; p < 0.05), and high TLG (HR: 1.97, 95% CI: 1.14–3.44; p < 0.05) as independent negative predictors. Conclusions: Pretreatment volume-based quantitative {sup 18}F-FDG PET/CT parameters, especially TLG, could serve as potential surrogate markers for MPM prognosis.

ASACUSA's radio-frequency quadrupole decelerator, open to show the four-rod structure along the centre, which crosses 35 resonator chambers formed by the vertical partitions.

CERN Multimedia

Laurent Guiraud

2000-01-01

The Radio-Frequency Quadrupole, RFQD, which further decelerates antiprotons ejected from the Antiproton Decelerator (AD). Starting from a momentum of 100 MeV/c (kinetic energy 5.3 MeV), the RFQD delivers very-low-energy antiprotons, adjustable between 10 and 110 keV, to the experiment ASACUSA. In picture _02, the view from the upstream end shows its 4-rod structure, traversing 35 resonator chambers formed by the vertical partitions. The tank has an inner diameter of 390 mm and is pumped to a vacuum of a few E-8 Torr.

Derivation of parameters necessary for the evaluation of performance of sites for deep geological repositories with particular reference to bedded salt, Livermore, California. Volume II. Appendices

International Nuclear Information System (INIS)

Ashby, J.P.; Rawlings, G.E.; Soto, C.A.; Wood, D.F.; Chorley, D.W.

1979-12-01

The method of selection of parameters to be considered in the selection of a site for underground disposal of radioactive wastes is reported in volume 1. This volume contains the appendix to that report. The topics include: specific rock mechanics tests; drilling investigation techniques and equipment; geophysical surveying; theoretical study of a well text in a nonhomogeneous aquifer; and basic statistical and probability theory that may be used in the derivation of input parameters

Testing backreaction effects with observational Hubble parameter data

Energy Technology Data Exchange (ETDEWEB)

Cao, Shu-Lei; Teng, Huan-Yu [Beijing Normal University, Department of Astronomy, Beijing (China); Wan, Hao-Yi [Beijing Normal University, Department of Astronomy, Beijing (China); National Astronomical Observatories, Chinese Academy of Sciences, Beijing (China); Yu, Hao-Ran [Shanghai Jiao Tong University, Tsung-Dao Lee Institute, Shanghai (China); Zhang, Tong-Jie [Dezhou University, Dezhou (China); Beijing Normal University, Department of Astronomy, Beijing (China)

2018-02-15

The spatially averaged inhomogeneous Universe includes a kinematical backreaction term Q{sub D} that is relate to the averaged spatial Ricci scalar left angle R right angle {sub D} in the framework of general relativity. Under the assumption that Q{sub D} and left angle R right angle {sub D} obey the scaling laws of the volume scale factor a{sub D}, a direct coupling between them with a scaling index n is remarkable. In order to explore the generic properties of a backreaction model for explaining the accelerated expansion of the Universe, we exploit two metrics to describe the late time Universe. Since the standard FLRW metric cannot precisely describe the late time Universe on small scales, the template metric with an evolving curvature parameter κ{sub D}(t) is employed. However, we doubt the validity of the prescription for κ{sub D}, which motivates us apply observational Hubble parameter data (OHD) to constrain parameters in dust cosmology. First, for FLRW metric, by getting best-fit constraints of Ω{sup D{sub 0m}} = 0.25{sup +0.03}{sub -0.03}, n = 0.02{sup +0.69}{sub -0.66}, and H{sub D{sub 0}} = 70.544{sup +4.24}{sub -3.97} km s{sup -1} Mpc{sup -1}, the evolutions of parameters are explored. Second, in template metric context, by marginalizing over H{sub D{sub 0}} as a prior of uniform distribution, we obtain the best-fit values of n = -1.22{sup +0.68}{sub -0.41} and Ω{sub m}{sup D{sub 0}} = 0.12{sup +0.04}{sub -0.02}. Moreover, we utilize three different Gaussian priors of H{sub D{sub 0}}, which result in different best-fits of n, but almost the same best-fit value of Ω{sub m}{sup D{sub 0}} ∝ 0.12. Also, the absolute constraints without marginalization of parameter are obtained: n = -1.1{sup +0.58}{sub -0.50} and Ω{sub m}{sup D{sub 0}} = 0.13 ± 0.03. With these constraints, the evolutions of the effective deceleration parameter q{sup D} indicate that the backreaction can account for the accelerated expansion of the Universe without involving extra

Erythromycin antagonizes the deceleration of gastric emptying by glucagon-like peptide 1 and unmasks its insulinotropic effect in healthy subjects

DEFF Research Database (Denmark)

Meier, Juris J; Kemmeries, Guido; Holst, Jens Juul

2005-01-01

. On separate occasions, the prokinetic drugs metoclopramide (10 mg), domperidone (10 mg), cisapride (10 mg, all at -30 min per oral), or erythromycin (200 mg intravenously from -30 to -15 min) were administered in addition to GLP-1. A liquid test meal (50 g sucrose and 8% mixed amino acids in 400 ml......, we aimed to antagonize the deceleration of gastric emptying by GLP-1 to study its effects on insulin secretion after a meal. Nine healthy male volunteers (age 25 +/- 4 years, BMI 25.0 +/- 4.9 kg/m2) were studied with an infusion of GLP-1 (0.8 pmol.kg(-1).min(-1) from -30 to 240 min) or placebo...... technique. Statistical analyses were performed using repeated-measures ANOVA and Duncan's post hoc test. GLP-1 significantly decelerated the velocity of gastric emptying (P drugs used had no effect. Postprandial...

Decelerating defects and non-ergodic critical behaviour in a unidirectionally coupled map lattice

International Nuclear Information System (INIS)

Ashwin, Peter; Sturman, Rob

2003-01-01

We examine a coupled map lattice (CML) consisting of an infinite chain of logistic maps coupled in one direction by inhibitory coupling. We find that for sufficiently strong coupling strength there are dynamical states with 'decelerating defects', where defects between stable patterns (with chaotic temporal evolution and average spatial period two) slow down but never stop. These defects annihilate each other when they meet. We show for certain states that this leads to a lack of convergence (non-ergodicity) of averages taken from observables in the system and conjecture that this is typical for the system

Systematic review of dose-volume parameters in the prediction of esophagitis in thoracic radiotherapy

International Nuclear Information System (INIS)

Rose, Jim; Rodrigues, George; Yaremko, Brian; Lock, Michael; D'Souza, David

2009-01-01

Purpose: With dose escalation and increasing use of concurrent chemoradiotherapy, radiation esophagitis (RE) remains a common treatment-limiting acute side effect in the treatment of thoracic malignancies. The advent of 3DCT planning has enabled investigators to study esophageal dose-volume histogram (DVH) parameters as predictors of RE. The purpose of this study was to assess published dosimetric parameters and toxicity data systematically in order to define reproducible predictors of RE, both for potential clinical use, and to provide recommendations for future research in the field. Materials and methods: We performed a systematic literature review of published studies addressing RE in the treatment of lung cancer and thymoma. Our search strategy included a variety of electronic medical databases, textbooks and bibliographies. Both prospective and retrospective clinical studies were included. Information relating to the relationship among measured dosimetric parameters, patient demographics, tumor characteristics, chemotherapy and RE was extracted and analyzed. Results: Eighteen published studies were suitable for analysis. Eleven of these assessed acute RE, while the remainder assessed both acute and chronic RE together. Heterogeneity of esophageal contouring practices, individual differences in information reporting and variability of RE outcome definitions were assessed. Well-described clinical and logistic modeling directly related V 35Gy , V 60Gy and SA 55Gy to clinically significant RE. Conclusions: Several reproducible dosimetric parameters exist in the literature, and these may be potentially relevant in the prediction of RE in the radiotherapy of thoracic malignancies. Further clarification of the predictive relationship between such standardized dosimetric parameters and observed RE outcomes is essential to develop efficient radiation treatment planning in locally advanced NSCLC in the modern concurrent chemotherapy and image-guided IMRT era.

Impact of electromechanical parameter variations in treatment volume doses and adjacent structures; Impacto da variacao dos parametros eletro-mecanicos nas doses do volume de tratamento e nas estruturas adjacentes

Energy Technology Data Exchange (ETDEWEB)

Morais, M.E.; Campos, A.M. [Instituto Nacional do Cancer (INCa), Rio de Janeiro, RJ (Brazil). Programa de Qualidade em Radioterapia]. E-mails: memorais@yahoo.com.br; amcampos@inca.gov.br; Goncalves, J. F. [Instituto de Oncologia e Radioterapia GV, Governador Valadares, MG (Brazil)]. E-mail: joelfgoncalves@yahoo.com.br; Ferreira, M.L. [Centro Radioterapico Gavea, Rio de Janeiro, RJ (Brazil)]. E-mail: mluciaf@yahoo.com

2003-07-01

ICRU Report 62 recommends that radiotherapy treatment dose should be prescribed in such a way that the dose to the target volume varies no more than 10%. In order to keep this goal, a very important role is played by the quality assurance (QA) of the treatment unit associated to the high level work of the personnel involved in planning and patient treatment. This paper shows the influence of the main electrical and mechanical linear accelerator parameters: field size, source-skin distance, gantry angle and light x radiation field coincidence in tumor volume and adjacent organ doses. We simulated a cubic tumor and a cubic adjacent critical organ in a cubic phantom and used a 3D Prowess system for planning. The treatment has been simulated for a 6 MV linear accelerator. We simulated two treatment planning: one using all the parameters inside their tolerance limits and another doubling these limits. The final results have show that, if the irradiation machine operates out of the tolerance limits, the dose variation in the planning target volume (PTV) can goes till {+-} 5,8% and in the critical adjacent organ till {+-} 7,7%. Therefore we concluded that, according to the complexity of the treatment, it can be necessary to reduce the tolerance levels advised by the IAEA/TECDOC - 1151. (author)

Elevation profile influence at key contractual performance parameters for LDS (Leak Detection Systems) based on compensated volume balance

Energy Technology Data Exchange (ETDEWEB)

Liebenberg, Lieb [TRANSNET Pipeline, Durban (South Africa); Bueno, David; Passos, Rafaela [KANOPUS Consulting, Rio de Janeiro, RJ (Brazil)

2009-07-01

This paper describes and discusses procedures and correlations to estimate performance parameters for Leak Detection Systems based on Compensation Volume Balance, at the portions not usually covered by international standards (like, API RP 1130). These parameters include: minimum acceptable leakage to be detected, under steady state conditions, based on flow measurement uncertainty, observed for both pipeline head and tail; an actual flow rate uncertainty against the one informed by the flow meter manufacturer documentation; the reference flow rate for steady state conditions; and the sensitivity one may expect for the system against a given probability of false alarms (i.e., the ways to correlate reliability, the main performance parameter as per API RP 1130 and sensitivity, the second one). A question usually not considered is: how the elevation profile may affect some of these parameters. That is the second main objective addressed herein, with actual examples employed in a South African multi product pipeline. (author)

Exploration of the hydrogen producing potential of Rhodobacter capsulatus chemostat cultures: The application of deceleration-stat and gradient-stat methodology

NARCIS (Netherlands)

Hoekema, S.; Breukelen, van F.R.; Janssen, M.G.J.; Tramper, J.; Wijffels, R.H.

2009-01-01

In this work, the dependency of the volumetric hydrogen production rate of ammonium-limited Rhodobacter capsulatus chemostat cultures on their imposed biomass concentration and dilution rate was investigated. A deceleration-stat experiment was performed by lowering the dilution rate from 1.0 d-1 to

Design parameters and source terms: Volume 1, Design parameters: Revision 0

International Nuclear Information System (INIS)

1987-10-01

The Design Parameters and Source Terms Document was prepared in accordance with DOE request and to provide data for the environmental impact study to be performed in the future for the Deaf Smith County, Texas site for a nuclear waste repository in salt. This document updates a previous unpublished report by Stearns Catalytic Corporation (SCC), entitled ''Design Parameters and Source Terms for a Two-Phase Repository in Salt,'' 1985, to the level of the Site Characterization Plan - Conceptual Design Report. The previous unpublished SCC Study identifies the data needs for the Environmental Assessment effort for seven possible Salt Repository sites

Pathophysiological and behavioral deficits in developing mice following rotational acceleration-deceleration traumatic brain injury

Directory of Open Access Journals (Sweden)

Guoxiang Wang

2018-01-01

Full Text Available Abusive head trauma (AHT is the leading cause of death from trauma in infants and young children. An AHT animal model was developed on 12-day-old mice subjected to 90° head extension-flexion sagittal shaking repeated 30, 60, 80 and 100 times. The mortality and time until return of consciousness were dependent on the number of repeats and severity of the injury. Following 60 episodes of repeated head shakings, the pups demonstrated apnea and/or bradycardia immediately after injury. Acute oxygen desaturation was observed by pulse oximetry during respiratory and cardiac suppression. The cerebral blood perfusion was assessed by laser speckle contrast analysis (LASCA using a PeriCam PSI system. There was a severe reduction in cerebral blood perfusion immediately after the trauma that did not significantly improve within 24 h. The injured mice began to experience reversible sensorimotor function at 9 days postinjury (dpi, which had completely recovered at 28 dpi. However, cognitive deficits and anxiety-like behavior remained. Subdural/subarachnoid hemorrhage, damage to the brain-blood barrier and parenchymal edema were found in all pups subjected to 60 insults. Proinflammatory response and reactive gliosis were upregulated at 3 dpi. Degenerated neurons were found in the cerebral cortex and olfactory tubercles at 30 dpi. This mouse model of repetitive brain injury by rotational head acceleration-deceleration partially mimics the major pathophysiological and behavioral events that occur in children with AHT. The resultant hypoxia/ischemia suggests a potential mechanism underlying the secondary rotational acceleration-deceleration-induced brain injury in developing mice.

The Effect of Dose-Volume Parameters and Interfraction Interval on Cosmetic Outcome and Toxicity After 3-Dimensional Conformal Accelerated Partial Breast Irradiation

International Nuclear Information System (INIS)

Leonard, Kara Lynne; Hepel, Jaroslaw T.; Hiatt, Jessica R.; Dipetrillo, Thomas A.; Price, Lori Lyn; Wazer, David E.

2013-01-01

Purpose: To evaluate dose-volume parameters and the interfraction interval (IFI) as they relate to cosmetic outcome and normal tissue effects of 3-dimensional conformal radiation therapy (3D-CRT) for accelerated partial breast irradiation (APBI). Methods and Materials: Eighty patients were treated by the use of 3D-CRT to deliver APBI at our institutions from 2003-2010 in strict accordance with the specified dose-volume constraints outlined in the National Surgical Adjuvant Breast and Bowel Project B39/Radiation Therapy Oncology Group 0413 (NSABP-B39/RTOG 0413) protocol. The prescribed dose was 38.5 Gy in 10 fractions delivered twice daily. Patients underwent follow-up with assessment for recurrence, late toxicity, and overall cosmetic outcome. Tests for association between toxicity endpoints and dosimetric parameters were performed with the chi-square test. Univariate logistic regression was used to evaluate the association of interfraction interval (IFI) with these outcomes. Results: At a median follow-up time of 32 months, grade 2-4 and grade 3-4 subcutaneous fibrosis occurred in 31% and 7.5% of patients, respectively. Subcutaneous fibrosis improved in 5 patients (6%) with extended follow-up. Fat necrosis developed in 11% of women, and cosmetic outcome was fair/poor in 19%. The relative volume of breast tissue receiving 5%, 20%, 50%, 80%, and 100% (V5-V100) of the prescribed dose was associated with risk of subcutaneous fibrosis, and the volume receiving 50%, 80%, and 100% (V50-V100) was associated with fair/poor cosmesis. The mean IFI was 6.9 hours, and the minimum IFI was 6.2 hours. The mean and minimum IFI values were not significantly associated with late toxicity. Conclusions: The incidence of moderate to severe late toxicity, particularly subcutaneous fibrosis and fat necrosis and resulting fair/poor cosmesis, remains high with continued follow-up. These toxicity endpoints are associated with several dose-volume parameters. Minimum and mean IFI values were

Hypersonic Inflatable Aerodynamic Decelerator Ground Test Development

Science.gov (United States)

Del Corso, Jospeh A.; Hughes, Stephen; Cheatwood, Neil; Johnson, Keith; Calomino, Anthony

2015-01-01

Hypersonic Inflatable Aerodynamic Decelerator (HIAD) technology readiness levels have been incrementally matured by NASA over the last thirteen years, with most recent support from NASA's Space Technology Mission Directorate (STMD) Game Changing Development Program (GCDP). Recently STMD GCDP has authorized funding and support through fiscal year 2015 (FY15) for continued HIAD ground developments which support a Mars Entry, Descent, and Landing (EDL) study. The Mars study will assess the viability of various EDL architectures to enable a Mars human architecture pathfinder mission planned for mid-2020. At its conclusion in November 2014, NASA's first HIAD ground development effort had demonstrated success with fabricating a 50 W/cm2 modular thermal protection system, a 400 C capable inflatable structure, a 10-meter scale aeroshell manufacturing capability, together with calibrated thermal and structural models. Despite the unquestionable success of the first HIAD ground development effort, it was recognized that additional investment was needed in order to realize the full potential of the HIAD technology capability to enable future flight opportunities. The second HIAD ground development effort will focus on extending performance capability in key technology areas that include thermal protection system, lifting-body structures, inflation systems, flight control, stage transitions, and 15-meter aeroshell scalability. This paper presents an overview of the accomplishments under the baseline HIAD development effort and current plans for a follow-on development effort focused on extending those critical technologies needed to enable a Mars Pathfinder mission.

Modeling the spatial distribution of the parameters of the coolant in the reactor volume

International Nuclear Information System (INIS)

Nikonov, S.P.

2011-01-01

In this paper the approach to the question about the spatial distribution of the parameters of the coolant in-reactor volume. To describe the in-core space is used specially developed preprocessor. When the work of the preprocessor in the first place, is recreated on the basis of available information (mostly-the original drawings) with high accuracy three-dimensional description of the structures of the reactor volume and, secondly, are prepared on this basis blocks input to the nodal system code improved estimate ATHLET, allows to take into account the hydrodynamic interaction between the spatial control volumes. As an example the special case of solutions of international standard problem on the reconstruction of the transition process in the third unit of the Kalinin nuclear power plant, due to the shutdown of one of the four Main Coolant Pumps in operation at the rated capacity (first download). Model-core area consists of approximately 58 000 control volumes and spatial relationships. It shows the influence of certain structural units of the core to the distribution of the mass floe rate of its height. It is detected a strong cross-flow coolant in the area over the baffle. Moreover, we study the distribution of the coolant temperature at the assembly head of WWER-1000 reactor. It is shown that in the region of the top of the assembly head, where we have installation of thermocouples, the flow coolant for internal assemblies core is formed by only from guide channel Reactor control and protected system Control rod flow, or a mixture of the guide channel flow and flow from the area in front of top grid head assembly (the peripheral assemblies). It is shown that the magnitude of the flow guide channels affects not only the position of control rods, but also the presence of a particular type of measuring channels (Self powered neutron detector sensors or Temperature control sensors) in the cassette. (Author)

Inclusion of functional information from perfusion SPECT improves predictive value of dose-volume parameters in lung toxicity outcome after radiotherapy for non-small cell lung cancer: A prospective study

DEFF Research Database (Denmark)

Farr, Katherina P; Kallehauge, Jesper F; Møller, Ditte S

2015-01-01

for corresponding standard parameters, but they were not significantly different from each other. CONCLUSION: SPECT-based functional parameters were better to predict the risk of RP compared to standard CT-based dose-volume parameters. Functional parameters may be useful to guide radiotherapy planning in order...

Accelerated and Decelerated Flows in a Circular Pipe : 1st Report, Velocity Profile and Friction Coefficient

OpenAIRE

Kurokawa, Junichi; Morikawa, Masahiro

1986-01-01

In order to determine the flow characteristics of a transient flow in a circular pipe, an accelerated and a decelerated flow are studied, and effects of acceleration upon the formation of a velocity profile, transition and a friction coefficient are determined for a wide range of accelerations. The results of the accelerated flow show that there are two patterns in the formation of a sectional velocity profile and transition, one of which is observed when the acceleration is relatively large ...

Diastolic Function in Normal Sinus Rhythm vs. Chronic Atrial Fibrillation: Comparison by Fractionation of E-wave Deceleration Time into Stiffness and Relaxation Components.

Science.gov (United States)

Mossahebi, Sina; Kovács, Sándor J

2014-01-01

Although the electrophysiologic derangement responsible for atrial fibrillation (AF) has been elucidated, how AF remodels the ventricular chamber and affects diastolic function (DF) has not been fully characterized. The previously validated Parametrized Diastolic Filling (PDF) formalism models suction-initiated filling kinematically and generates error-minimized fits to E-wave contours using unique load (x o ), relaxation (c), and stiffness (k) parameters. It predicts that E-wave deceleration time (DT) is a function of both stiffness and relaxation. Ascribing DT s to stiffness and DTr to relaxation such that DT=DT s +DT r is legitimate because of causality and their predicted and observed high correlation (r=0.82 and r=0.94) with simultaneous (diastatic) chamber stiffness (dP/dV) and isovolumic relaxation (tau), respectively. We analyzed simultaneous echocardiography-cardiac catheterization data and compared 16 age matched, chronic AF subjects to 16, normal sinus rhythm (NSR) subjects (650 beats). All subjects had diastatic intervals. Conventional DF parameters (DT, AT, E peak , E dur , E-VTI, E/E') and E-wave derived PDF parameters (c, k, DT s , DT r ) were compared. Total DT and DT s , DT r in AF were shorter than in NSR (pwave DT in AF is due to stiffness compared to NSR. By trending individual subjects, this method can elucidate and characterize the beneficial or adverse long-term effects on chamber remodeling due to alternative therapies in terms of chamber stiffness and relaxation.

Deceleration of arginine kinase refolding by induced helical structures.

Science.gov (United States)

Li, Hai-Long; Zhou, Sheng-Mei; Park, Daeui; Jeong, Hyoung Oh; Chung, Hae Young; Yang, Jun-Mo; Meng, Fan-Guo; Hu, Wei-Jiang

2012-04-01

Arginine kinase (AK) is a key metabolic enzyme for keeping energy balance in invertebrates. Therefore, regulation of the enzymatic activity and the folding studies of AK from the various invertebrates have been the focus of investigation. We studied the effects of helical structures by using hexafluoroisopropanol (HFIP) on AK folding. Folding kinetic studies showed that the folding rates of the urea-denatured AKs were significantly decelerated after being induced in various concentrations of HFIP. AK lost its activity completely at concentrations greater than 60%. The results indicated that the HFIP-induced helical structures in the denatured state play a negative role in protein folding, and the helical structures induced in 5% (v/v) HFIP act as the most effective barrier against AK taking its native structure. The computational docking simulations (binding energies for -2.19 kcal/mol for AutoDock4.2 and -20.47 kcal/mol for Dock6.3) suggested that HFIP interacts with the several important residues that are predicted by both programs. The excessively pre-organized helical structures not only hampered the folding process, but also ultimately brought about changes in the three-dimensional conformation and biological function of AK.

Mechanically-Deployed Hypersonic Decelerator and Conformal Ablator Technologies for Mars Missions

Science.gov (United States)

Venkatapathy, Ethiraj; Wercinski, Paul F.; Beck, Robin A. S.; Hamm, Kenneth R.; Yount, Bryan C.; Makino, A.; Smith, B.; Gage, P.; Prabhu, D.

2012-01-01

The concept of a mechanically deployable hypersonic decelerator, developed initially for high mass (40 MT) human Mars missions, is currently funded by OCT for technology maturation. The ADEPT (Adaptive, Deployable Entry and Placement Technology) project has broad, game-changing applicability to in situ science missions to Venus, Mars, and the Outer Planets. Combined with maturation of conformal ablator technology (another current OCT investment), the two technologies provide unique low mass mission enabling capabilities otherwise not achievable by current rigid aeroshell or by inflatables. If this abstract is accepted, we will present results that illustrate the mission enabling capabilities of the mechanically deployable architecture for: (1) robotic Mars (Discovery or New Frontiers class) in the near term; (2) alternate approaches to landing MSL-class payloads, without the need for supersonic parachute or lifting entry, in the mid-term; and (3) Heavy mass and human missions to Mars in the long term.

Optimization of plasma flow parameters of the magnetoplasma compressor

International Nuclear Information System (INIS)

Dojcinovic, I P; Kuraica, M M; Obradovc, B M; Cvetanovic, N; Puric, J

2007-01-01

Optimization of the working conditions of the magnetoplasma compressor (MPC) has been performed through analysing discharge and compression plasma flow parameters in hydrogen, nitrogen and argon at different pressures. Energy conversion rate, volt-ampere curve exponent and plasma flow velocities have been studied to optimize the efficiency of energy transfer from the supply source to the plasma. It has been found that the most effective energy transfer from the supply to the plasma is in hydrogen as a working gas at 1000 Pa pressure. It was found that the accelerating regime exists for hydrogen up to 3000 Pa pressures, in nitrogen up to 2000 Pa and in argon up to 1000 Pa pressure. At higher pressures MPC in all the gases works in the decelerating regime. At pressures lower than 200 Pa, high cathode erosion is observed. MPC plasma flow parameter optimization is very important because this plasma accelerating system may be of special interest for solid surface modification and other technology applications

Design and Execution of the Hypersonic Inflatable Aerodynamic Decelerator Large-Article Wind Tunnel Experiment

Science.gov (United States)

Cassell, Alan M.

2013-01-01

The testing of 3- and 6-meter diameter Hypersonic Inflatable Aerodynamic Decelerator (HIAD) test articles was completed in the National Full-Scale Aerodynamics Complex 40 ft x 80 ft Wind Tunnel test section. Both models were stacked tori, constructed as 60 degree half-angle sphere cones. The 3-meter HIAD was tested in two configurations. The first 3-meter configuration utilized an instrumented flexible aerodynamic skin covering the inflatable aeroshell surface, while the second configuration employed a flight-like flexible thermal protection system. The 6-meter HIAD was tested in two structural configurations (with and without an aft-mounted stiffening torus near the shoulder), both utilizing an instrumented aerodynamic skin.

The deceleration of aircraft in overrun accidents from the point of first impact to the end of the wreckage path

Directory of Open Access Journals (Sweden)

David Pitfield

2015-02-01

Full Text Available Purpose: This paper outlines previous attempts to model aircraft deceleration and using a newer database containing a greater number of observations tries to refine the model.Design/Methodology: It is noted that data inadequacies still necessitate the estimation of a given acceleration for the aircraft wreckage path, but that there are more opportunities to change the intercept in a regression model to reflect categorical and dummy variables that proxy factors such as runway condition, the degree of control exercised by the pilot during the crash, the speed at the point of first impact (hereafter POFI, headwind, rain, characteristics of the terrain on the wreckage path  and aborted take-offs. Findings: The contribution of some of the explanatory variables can be seen. It is a shame other potential influences are not found to be significant. It is important to understand deceleration so that the wreckage location of aircraft accidents can be understood. This then gives guidance of appropriate runway safety areas. Originality/ value: This is the first time this has been attempted on the expanded accident database.

The FLUKA study of the secondary particles fluence in the AD-Antiproton Decelerator target area

CERN Document Server

Calviani, M

2014-01-01

In this paper we present Monte Carlo FLUKA simulations [1, 2] carried out to investigate the secondary particles fluence emerging from the antiproton production target and their spatial distribution in the AD target area. The detailed quantitative analysis has been performed for different positions along the magnet dog-leg as well as after the main collimator. These results allow tuning the position of the new beam current transformers (BCT) in the target area, in order to have a precise pulse-by-pulse evaluation of the intensity of negative particles injected in the AD-ring before the deceleration phase.

Fibre Optic Notch Filter For The Antiproton Decelerator Stochastic Cooling System

CERN Document Server

Simmonds, Max Vincent John

2016-01-01

The project scope included reverse engineering, upgrading, and recovering the operational conditions of an existing fibre optic notch filter. Once operational, tests were to be preformed to confirm the performance of the temperature stabilisation. The end goal is to use said notch filter in the Antiproton Decelerator (AD) facility at CERN to help aid antimatter research. The notch filter was successfully reverse engineered and then documented. Changes were made in order to increase performance and reliability, and also allow easy integration into the AD. An additional phase was added whereby the notch filter was to be controller via a touchscreen computer, situated next to the filter, allowing engineers to set-up each of the electronic devices used. While one of the devices (Motorised Delay Line) can be controlled by the touchscreen computer, the other two cannot.Due to time constraints and difficulties with the Beckhoff TwincatII programming language, the USB devices were not able to be controlled via the To...

SU-E-T-143: Effect of X-Ray and Cone Beam CT Reconstruction Parameters On Estimation of Bone Volume of Mice Used in Aging Research

Energy Technology Data Exchange (ETDEWEB)

Russ, M; Pang, M; Troen, B; Rudin, S; Ionita, C [University at Buffalo, Buffalo, NY (United States)

2014-06-01

Purpose: To investigate the variations in bone volume calculations in mice involved in aging research when changing cone beam micro-CT x-ray and reconstruction parameters. Methods: Mouse spines were placed on an indexed turn table that rotated 0.5° per projection and imaged by a self-built micro CT machine containing a CCD-based high-resolution x-ray detector. After the full 360° rotation data set of object images was obtained, a standard filtered back-projection cone beam reconstruction was performed. Four different kVp's between 40–70 kVp in 10kVp increments were selected. For each kVp two mAs settings were used. Each acquisition was reconstructed using two voxel sizes (12 and 25μm) and two step angles, 0.5° and 1°, respectively. A LabView program was written to determine the total bone volume contained in the mouse's total spine volume (bone plus gaps) as a measure of spine health. First, the user selected the desired 512×512 reconstruction to view the whole spine volume which was then used to select a gray-level threshold that allowed for viewing of the bone structure, then another threshold to include gaps. The program returned bone volume, bone × gap volume, and their ratio, BVF. Results: The calculated bone volume fractions were compared as a function of tube potential. Cases with 25μm slice thickness showed trials with lower kVp's had greater image contrast, which resulted in higher calculated bone volume fractions. Cases with 12μm reconstructed slice thickness were significantly noisier, and showed no clear maximum BVF. Conclusion: Using the projection images and reconstructions acquired from the micro CT, it can be shown that the micro-CT x-ray and reconstruction parameters significantly affect the total bone volume calculations. When comparing mice cohorts treated with different therapies researchers need to be aware of such details and use volumes which were acquired and processed in identical conditions.

Pancreas volume and fat fraction in children with Type 1 diabetes.

Science.gov (United States)

Regnell, S E; Peterson, P; Trinh, L; Broberg, P; Leander, P; Lernmark, Å; Månsson, S; Elding Larsson, H

2016-10-01

People with Type 1 diabetes have smaller pancreases than healthy individuals. Several diseases causing pancreatic atrophy are associated with pancreatic steatosis, but pancreatic fat in Type 1 diabetes has not been measured. This cross-sectional study aimed to compare pancreas size and fat fraction in children with Type 1 diabetes and controls. The volume and fat fraction of the pancreases of 22 children with Type 1 diabetes and 29 controls were determined using magnetic resonance imaging. Pancreas volume was 27% smaller in children with diabetes (median 34.9 cm(3) ) than in controls (47.8 cm(3) ; P Pancreas volume correlated positively with age in controls (P = 0.033), but not in children with diabetes (P = 0.649). Pancreas volume did not correlate with diabetes duration, but it did correlate positively with units of insulin/kg body weight/day (P = 0.048). A linear model of pancreas volume as influenced by age, body surface area and insulin units/kg body weight/day found that insulin dosage correlated with pancreas volume after controlling for both age and body surface area (P = 0.009). Pancreatic fat fraction was not significantly different between the two groups (1.34% vs. 1.57%; P = 0.891). Our findings do not indicate that pancreatic atrophy in Type 1 diabetes is associated with an increased pancreatic fat fraction, unlike some other diseases featuring reduced pancreatic volume. We speculate that our results may support the hypotheses that much of pancreatic atrophy in Type 1 diabetes occurs before the clinical onset of the disease and that exogenous insulin administration decelerates pancreatic atrophy after diabetes onset. © 2016 Diabetes UK.

Effect of static shape deformation on aerodynamics and aerothermodynamics of hypersonic inflatable aerodynamic decelerator

Science.gov (United States)

Guo, Jinghui; Lin, Guiping; Bu, Xueqin; Fu, Shiming; Chao, Yanmeng

2017-07-01

The inflatable aerodynamic decelerator (IAD), which allows heavier and larger payloads and offers flexibility in landing site selection at higher altitudes, possesses potential superiority in next generation space transport system. However, due to the flexibilities of material and structure assembly, IAD inevitably experiences surface deformation during atmospheric entry, which in turn alters the flowfield around the vehicle and leads to the variations of aerodynamics and aerothermodynamics. In the current study, the effect of the static shape deformation on the hypersonic aerodynamics and aerothermodynamics of a stacked tori Hypersonic Inflatable Aerodynamic Decelerator (HIAD) is demonstrated and analyzed in detail by solving compressible Navier-Stokes equations with Menter's shear stress transport (SST) turbulence model. The deformed shape is obtained by structural modeling in the presence of maximum aerodynamic pressure during entry. The numerical results show that the undulating shape deformation makes significant difference to flow structure. In particular, the more curved outboard forebody surface results in local flow separations and reattachments in valleys, which consequently yields remarkable fluctuations of surface conditions with pressure rising in valleys yet dropping on crests while shear stress and heat flux falling in valleys yet rising on crests. Accordingly, compared with the initial (undeformed) shape, the corresponding differences of surface conditions get more striking outboard, with maximum augmentations of 379 pa, 2224 pa, and 19.0 W/cm2, i.e., 9.8%, 305.9%, and 101.6% for the pressure, shear stress and heat flux respectively. Moreover, it is found that, with the increase of angle of attack, the aerodynamic characters and surface heating vary and the aeroheating disparities are evident between the deformed and initial shape. For the deformable HIAD model investigated in this study, the more intense surface conditions and changed flight

Deep Learning Algorithm for Auto-Delineation of High-Risk Oropharyngeal Clinical Target Volumes With Built-In Dice Similarity Coefficient Parameter Optimization Function.

Science.gov (United States)

Cardenas, Carlos E; McCarroll, Rachel E; Court, Laurence E; Elgohari, Baher A; Elhalawani, Hesham; Fuller, Clifton D; Kamal, Mona J; Meheissen, Mohamed A M; Mohamed, Abdallah S R; Rao, Arvind; Williams, Bowman; Wong, Andrew; Yang, Jinzhong; Aristophanous, Michalis

2018-06-01

Automating and standardizing the contouring of clinical target volumes (CTVs) can reduce interphysician variability, which is one of the largest sources of uncertainty in head and neck radiation therapy. In addition to using uniform margin expansions to auto-delineate high-risk CTVs, very little work has been performed to provide patient- and disease-specific high-risk CTVs. The aim of the present study was to develop a deep neural network for the auto-delineation of high-risk CTVs. Fifty-two oropharyngeal cancer patients were selected for the present study. All patients were treated at The University of Texas MD Anderson Cancer Center from January 2006 to August 2010 and had previously contoured gross tumor volumes and CTVs. We developed a deep learning algorithm using deep auto-encoders to identify physician contouring patterns at our institution. These models use distance map information from surrounding anatomic structures and the gross tumor volume as input parameters and conduct voxel-based classification to identify voxels that are part of the high-risk CTV. In addition, we developed a novel probability threshold selection function, based on the Dice similarity coefficient (DSC), to improve the generalization of the predicted volumes. The DSC-based function is implemented during an inner cross-validation loop, and probability thresholds are selected a priori during model parameter optimization. We performed a volumetric comparison between the predicted and manually contoured volumes to assess our model. The predicted volumes had a median DSC value of 0.81 (range 0.62-0.90), median mean surface distance of 2.8 mm (range 1.6-5.5), and median 95th Hausdorff distance of 7.5 mm (range 4.7-17.9) when comparing our predicted high-risk CTVs with the physician manual contours. These predicted high-risk CTVs provided close agreement to the ground-truth compared with current interobserver variability. The predicted contours could be implemented clinically, with only

Fetal growth, cognitive function, and brain volumes in childhood and adolescence.

Science.gov (United States)

Rogne, Tormod; Engstrøm, Andreas Aass; Jacobsen, Geir Wenberg; Skranes, Jon; Østgård, Heidi Furre; Martinussen, Marit

2015-03-01

To evaluate the association between fetal growth pattern and cognitive function at 5 and 9 years and regional brain volumes at 15 years. Eighty-three term-born small-for-gestational-age (SGA) neonates and 105 non-SGA neonates in a control group were available for follow-up. Based on serial fetal ultrasound measurements from gestational weeks 25-37, SGA neonates were classified with fetal growth restriction (n=13) or non-fetal growth restriction (n=36). Cognitive function was assessed at 5 and 9 years, and brain volumes were estimated with cerebral magnetic resonance imaging at 15 years. Small-for-gestational-age children had lower performance intelligence quotient at 5 years compared with those in a control group (107.3 compared with 112.5, Pgrowth restriction and control groups, the SGA fetal growth restriction group had significantly lower performance intelligence quotient at 5 years (103.5 compared with 112.5, Pgrowth restriction and control groups for thalamic (17.4 compared with 18.6 cm, Pintelligence quotient scores at 5 and 9 years and smaller brain volumes at 15 years compared with those in the control group, but these findings were only found in those with fetal growth restriction, indicating a possible relationship to decelerated fetal growth. II.

Intra-lesional spatial correlation of static and dynamic FET-PET parameters with MRI-based cerebral blood volume in patients with untreated glioma.

Science.gov (United States)

Göttler, Jens; Lukas, Mathias; Kluge, Anne; Kaczmarz, Stephan; Gempt, Jens; Ringel, Florian; Mustafa, Mona; Meyer, Bernhard; Zimmer, Claus; Schwaiger, Markus; Förster, Stefan; Preibisch, Christine; Pyka, Thomas

2017-03-01

18 F-fluorethyltyrosine-(FET)-PET and MRI-based relative cerebral blood volume (rCBV) have both been used to characterize gliomas. Recently, inter-individual correlations between peak static FET-uptake and rCBV have been reported. Herein, we assess the local intra-lesional relation between FET-PET parameters and rCBV. Thirty untreated glioma patients (27 high-grade) underwent simultaneous PET/MRI on a 3 T hybrid scanner obtaining structural and dynamic susceptibility contrast sequences. Static FET-uptake and dynamic FET-slope were correlated with rCBV within tumour hotspots across patients and intra-lesionally using a mixed-effects model to account for inter-individual variation. Furthermore, maximal congruency of tumour volumes defined by FET-uptake and rCBV was determined. While the inter-individual relationship between peak static FET-uptake and rCBV could be confirmed, our intra-lesional, voxel-wise analysis revealed significant positive correlations (median r = 0.374, p dynamic FET-PET variance and maximal overlap of respective tumour volumes was 37% on average. Our results show that the relation between peak values of MR-based rCBV and static FET-uptake can also be observed intra-individually on a voxel basis and also applies to a dynamic FET parameter, possibly determining hotspots of higher biological malignancy. However, just a small part of the FET-PET signal variance is explained by rCBV and tumour volumes determined by the two modalities showed only moderate overlap. These findings indicate that FET-PET and MR-based rCBV provide both congruent and complimentary information on glioma biology.

International Nuclear Model. Volume 3. Program description

International Nuclear Information System (INIS)

Andress, D.

1985-01-01

This is Volume 3 of three volumes of documentation of the International Nuclear Model (INM). This volume presents the Program Description of the International Nuclear Model, which was developed for the Nuclear and Alternate Fuels Division (NAFD), Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), US Department of Energy (DOE). The International Nuclear Model (INM) is a comprehensive model of the commercial nuclear power industry. It simulates economic decisions for reactor deployment and fuel management decision based on an input set of technical economic and scenario parameters. The technical parameters include reactor operating characteristics, fuel cycle timing and mass loss factors, and enrichment tails assays. Economic parameters include fuel cycle costs, financial data, and tax alternatives. INM has a broad range of scenario options covering, for example, process constraints, interregional activities, reprocessing, and fuel management selection. INM reports reactor deployment schedules, electricity generation, and fuel cycle requirements and costs. It also has specialized reports for extended burnup and permanent disposal. Companion volumes to Volume 3 are: Volume 1 - Model Overview, and Volume 2 - Data Base Relationships

Dose-Volume Histogram Parameters and Clinical Factors Associated With Pleural Effusion After Chemoradiotherapy in Esophageal Cancer Patients

International Nuclear Information System (INIS)

Shirai, Katsuyuki; Tamaki, Yoshio; Kitamoto, Yoshizumi; Murata, Kazutoshi; Satoh, Yumi; Higuchi, Keiko; Nonaka, Tetsuo; Ishikawa, Hitoshi; Katoh, Hiroyuki; Takahashi, Takeo; Nakano, Takashi

2011-01-01

Purpose: To investigate the dose-volume histogram parameters and clinical factors as predictors of pleural effusion in esophageal cancer patients treated with concurrent chemoradiotherapy (CRT). Methods and Materials: Forty-three esophageal cancer patients treated with definitive CRT from January 2001 to March 2007 were reviewed retrospectively on the basis of the following criteria: pathologically confirmed esophageal cancer, available computed tomography scan for treatment planning, 6-month follow-up after CRT, and radiation dose ≥50 Gy. Exclusion criteria were lung metastasis, malignant pleural effusion, and surgery. Mean heart dose, mean total lung dose, and percentages of heart or total lung volume receiving ≥10-60 Gy (Heart-V 10 to V 60 and Lung-V 10 to V 60 , respectively) were analyzed in relation to pleural effusion. Results: The median follow-up time was 26.9 months (range, 6.7-70.2) after CRT. Of the 43 patients, 15 (35%) developed pleural effusion. By univariate analysis, mean heart dose, Heart-V 10 to V 60 , and Lung-V 50 to V 60 were significantly associated with pleural effusion. Poor performance status, primary tumor of the distal esophagus, and age ≥65 years were significantly related with pleural effusion. Multivariate analysis identified Heart-V 50 as the strongest predictive factor for pleural effusion (p = 0.01). Patients with Heart-V 50 50 50 ≥40% had 6%, 44%, and 64% of pleural effusion, respectively (p 50 is a useful parameter for assessing the risk of pleural effusion and should be reduced to avoid pleural effusion.

Predictive value of late decelerations for fetal acidemia in unselective low-risk pregnancies.

Science.gov (United States)

Sameshima, Hiroshi; Ikenoue, Tsuyomu

2005-01-01

We evaluated the clinical significance of late decelerations (LD) of intrapartum fetal heart rate (FHR) monitoring to detect low pH (LD (occasional, 50%; recurrent, > or = 50%) and severity (reduced baseline FHR accelerations and variability) of LD, and low pH (test, and one-way analysis of variance with the Bonferroni/Dunn test. In the 5522 low-risk pregnancies, 301 showed occasional LD and 99 showed recurrent LD. Blood gases and pH values deteriorated as the incidence of LD increased and as baseline accelerations or variability was decreased. Positive predictive value for low pH (LD, and > 50% in recurrent LD with no baseline FHR accelerations and reduced variability. In low-risk pregnancies, information on LD combined with acceleration and baseline variability enables us to predict the potential incidence of fetal acidemia.

Constraints on cosmological parameters in power-law cosmology

International Nuclear Information System (INIS)

Rani, Sarita; Singh, J.K.; Altaibayeva, A.; Myrzakulov, R.; Shahalam, M.

2015-01-01

In this paper, we examine observational constraints on the power law cosmology; essentially dependent on two parameters H 0 (Hubble constant) and q (deceleration parameter). We investigate the constraints on these parameters using the latest 28 points of H(z) data and 580 points of Union2.1 compilation data and, compare the results with the results of ΛCDM . We also forecast constraints using a simulated data set for the future JDEM, supernovae survey. Our studies give better insight into power law cosmology than the earlier done analysis by Kumar [arXiv:1109.6924] indicating it tuning well with Union2.1 compilation data but not with H(z) data. However, the constraints obtained on and i.e. H 0 average and q average using the simulated data set for the future JDEM, supernovae survey are found to be inconsistent with the values obtained from the H(z) and Union2.1 compilation data. We also perform the statefinder analysis and find that the power-law cosmological models approach the standard ΛCDM model as q → −1. Finally, we observe that although the power law cosmology explains several prominent features of evolution of the Universe, it fails in details

Analysis of dose volume histogram parameters to estimate late bladder and rectum complications after high-dose (70-78 Gy) conformal radiotherapy for prostate cancer

International Nuclear Information System (INIS)

Boersma, L.J.; Brink, M. van den; Bruce, A.; Gras, L.; Velde, A. te; Lebesque, J.V.

1997-01-01

Purpose: To investigate whether Dose Volume Histogram (DVH) parameters can be used to identify risk groups for developing late gastrointestinal (GI) and genitourinary (GU) complications after conformal radiotherapy for prostate cancer, and to examine the effect of using different morbidity scoring systems on the results of these analyses. Materials and Methods: DVH parameters were analyzed for 130 patients with localized prostate cancer, treated with conformal radiotherapy in a dose-escalating protocol (70-78 Gy, 2 Gy per fraction). The incidence of late (> 6 months) GI and GU complications was scored based on questionnaires and classified using the RTOG/EORTC and the SOMA/LENT scoring system. Moreover, patients were classified as being a rectal bleeder or no rectal bleeder and a distinction was made between non-severe and severe (requiring one or more laser treatments) rectal bleeding. The median follow-up time was 22 months. It was investigated whether the relative and absolute rectal wall volumes, irradiated to various dose levels (≥ 60 Gy, ≥ 65 Gy, ≥ 70 Gy and ≥ 75 Gy) were correlated with the observed actuarial incidences of GI complications. First, the analysis was performed using volume as a continuous variable. Subsequently, for each dose level in the DVH the rectal wall volumes were dichotomized using different volumes as cut-off levels. Twenty cut-off levels were tested on their ability to discriminate between high and low risk for developing GI complications (Fig.). The relationship between bladder wall volumes irradiated to various dose levels and observed actuarial GU complications was investigated using the absolute bladder wall volumes, measured as a continuous variable. For both GI and GU complications, the role of the prescribed radiation dose and the maximum radiation dose in the rectal and bladder wall was analyzed as well. Results: None of the DVH parameters of the rectal wall was significantly correlated with the actuarial incidences of

Flexible Thermal Protection System Development for Hypersonic Inflatable Aerodynamic Decelerators

Science.gov (United States)

DelCorso, Joseph A.; Bruce, Walter E., III; Hughes, Stephen J.; Dec, John A.; Rezin, Marc D.; Meador, Mary Ann B.; Guo, Haiquan; Fletcher, Douglas G.; Calomino, Anthony M.; Cheatwood, McNeil

2012-01-01

The Hypersonic Inflatable Aerodynamic Decelerators (HIAD) project has invested in development of multiple thermal protection system (TPS) candidates to be used in inflatable, high downmass, technology flight projects. Flexible TPS is one element of the HIAD project which is tasked with the research and development of the technology ranging from direct ground tests, modelling and simulation, characterization of TPS systems, manufacturing and handling, and standards and policy definition. The intent of flexible TPS is to enable large deployable aeroshell technologies, which increase the drag performance while significantly reducing the ballistic coefficient of high-mass entry vehicles. A HIAD requires a flexible TPS capable of surviving aerothermal loads, and durable enough to survive the rigors of construction, handling, high density packing, long duration exposure to extrinsic, in-situ environments, and deployment. This paper provides a comprehensive overview of key work being performed within the Flexible TPS element of the HIAD project. Included in this paper is an overview of, and results from, each Flexible TPS research and development activity, which includes ground testing, physics-based thermal modelling, age testing, margins policy, catalysis, materials characterization, and recent developments with new TPS materials.

Risk of Late Urinary Complications Following Image Guided Adaptive Brachytherapy for Locally Advanced Cervical Cancer: Refining Bladder Dose-Volume Parameters.

Science.gov (United States)

Manea, Elena; Escande, Alexandre; Bockel, Sophie; Khettab, Mohamed; Dumas, Isabelle; Lazarescu, Ioana; Fumagalli, Ingrid; Morice, Philippe; Deutsch, Eric; Haie-Meder, Christine; Chargari, Cyrus

2018-06-01

To study correlations between dose-volume parameters of the whole bladder and bladder trigone and late urinary toxicity in locally advanced cervical cancer patients treated with pulsed-dose-rate brachytherapy. Patients with locally advanced cervical cancer treated with chemoradiation therapy and pulsed-dose-rate brachytherapy from 2004 to 2015 were included. Cumulative dose-volume parameters of the whole bladder and bladder trigone were converted into 2-Gy/fraction equivalents (EQD2, with α/β = 3 Gy); these parameters, as well as clinical factors, were analyzed as predictors of toxicity in patients without local relapse. A total of 297 patients fulfilled the inclusion criteria. The median follow-up period was 4.9 years (95% confidence interval 4.5-5.3 years). In patients without local relapse (n = 251), the Kaplan-Meier estimated grade 2 or higher urinary toxicity rates at 3 years and 5 years were 25.4% and 32.1%, respectively. Minimal dose to the most exposed 2 cm 3 of the whole bladder [Formula: see text] , bladder International Commission on Radiation Units & Measurements (ICRU) (B ICRU ) dose, and trigone dose-volume parameters correlated with grade 2 or higher toxicity. At 3 years, the cumulative incidence of grade 2 or higher complications was 22.8% (standard error, 2.9%) for bladder [Formula: see text]   60 Gy EQD2 was significant for grade 2 or higher toxicity (P = .027). The probability of grade 3 or higher toxicities increased with bladder [Formula: see text]  > 80 Gy EQD2 (16.7% vs 1.6%; hazard ratio [HR], 5.77; P = .039), B ICRU dose > 65 Gy EQD2 (4.9% vs 1.3%; HR, 6.36; P = .018), and trigone D 50%  > 60 Gy EQD2 (3.1% vs 1.2%; HR, 6.29; P = .028). Pearson correlation coefficients showed a moderate correlation between bladder [Formula: see text] , B ICRU dose, and bladder trigone D 50% (P < .0001). These data suggest that [Formula: see text]  ≤ 80 Gy EQD2 should be advised for minimizing the risk of severe urinary

Deceleration of probe beam by stage bias potential improves resolution of serial block-face scanning electron microscopic images.

Science.gov (United States)

Bouwer, James C; Deerinck, Thomas J; Bushong, Eric; Astakhov, Vadim; Ramachandra, Ranjan; Peltier, Steven T; Ellisman, Mark H

2017-01-01

Serial block-face scanning electron microscopy (SBEM) is quickly becoming an important imaging tool to explore three-dimensional biological structure across spatial scales. At probe-beam-electron energies of 2.0 keV or lower, the axial resolution should improve, because there is less primary electron penetration into the block face. More specifically, at these lower energies, the interaction volume is much smaller, and therefore, surface detail is more highly resolved. However, the backscattered electron yield for metal contrast agents and the backscattered electron detector sensitivity are both sub-optimal at these lower energies, thus negating the gain in axial resolution. We found that the application of a negative voltage (reversal potential) applied to a modified SBEM stage creates a tunable electric field at the sample. This field can be used to decrease the probe-beam-landing energy and, at the same time, alter the trajectory of the signal to increase the signal collected by the detector. With decelerated low landing-energy electrons, we observed that the probe-beam-electron-penetration depth was reduced to less than 30 nm in epoxy-embedded biological specimens. Concurrently, a large increase in recorded signal occurred due to the re-acceleration of BSEs in the bias field towards the objective pole piece where the detector is located. By tuning the bias field, we were able to manipulate the trajectories of the  primary and secondary electrons, enabling the spatial discrimination of these signals using an advanced ring-type BSE detector configuration or a standard monolithic BSE detector coupled with a blocking aperture.

Comprehensive Study for an Optimized Redesign of the CERN's Antiproton Decelerator Target

CERN Document Server

AUTHOR|(CDS)2089345; Perillo-Marcone, Antonio; Muñoz-Cobo, Jose-Luis

2018-04-16

The Antiproton Decelerator Target (AD-Target) is a unique device responsible for the production of antiprotons at the European Organization for Nuclear Research (CERN). During operation, intense 26 GeV energy proton beams are impacted into its core, made of a 3 mm diameter rod of a high density material such as iridium, creating secondary particles -including antiprotons- from the nuclear reactions induced in its interior. This thesis delves into the characteristics of antiproton production and in particular in the mechanical response of the target core material, which is exposed to a rise of temperature of approximate 2000 degrees Celsius in less than 0.5 microseconds each time is impacted by the primary proton beam. A coupled numerical-experimental approach has been applied for this purpose. Specific computational tools, called hydrocodes, have been used for simulating the extreme dynamic response taking place in the target core and its containing graphite matrix, indicating their potential damage and frag...

Quantitative CT: technique dependence of volume estimation on pulmonary nodules

Science.gov (United States)

Chen, Baiyu; Barnhart, Huiman; Richard, Samuel; Colsher, James; Amurao, Maxwell; Samei, Ehsan

2012-03-01

Current estimation of lung nodule size typically relies on uni- or bi-dimensional techniques. While new three-dimensional volume estimation techniques using MDCT have improved size estimation of nodules with irregular shapes, the effect of acquisition and reconstruction parameters on accuracy (bias) and precision (variance) of the new techniques has not been fully investigated. To characterize the volume estimation performance dependence on these parameters, an anthropomorphic chest phantom containing synthetic nodules was scanned and reconstructed with protocols across various acquisition and reconstruction parameters. Nodule volumes were estimated by a clinical lung analysis software package, LungVCAR. Precision and accuracy of the volume assessment were calculated across the nodules and compared between protocols via a generalized estimating equation analysis. Results showed that the precision and accuracy of nodule volume quantifications were dependent on slice thickness, with different dependences for different nodule characteristics. Other parameters including kVp, pitch, and reconstruction kernel had lower impact. Determining these technique dependences enables better volume quantification via protocol optimization and highlights the importance of consistent imaging parameters in sequential examinations.

Preoperative evaluation of liver volume parameters in living related donors by spiral computed tomography

International Nuclear Information System (INIS)

Michalak, M.; Pacho, R.; Pruszynski, B.; Paluszkiewicz, R.; Hevelke, P.; Krawczyk, M.

2002-01-01

The objective of the study is to assess the use of spiral computed tomography in the evaluation of the volume of the liver, its lobes, and selected segments in the preoperative period and to validate the used measurements. Thirty five potential donors (15 women and 20 men) aged 21-65 years were included. Based on the CT liver findings in the venous-portal phase and segment division of the liver according Couinaud the liver volume was calculated manually be a planimetric method, after making outlines of all liver sections. The volumes of lobes and selected segments were assessed by the same technique. The volumes of the resected liver segments calculated based on the CT findings were compared with appropriate measurements made during the operation. The total liver volume ranged between 804 and 1842 cm 3 (mean - 1456 cm 3 , standard deviation [SD] - 247). The volume of the right liver lobe including caudate lobe was 555 cm 3 to 1382 cm 3 (mean - 1024, SD - 186) that is in average 70.4% of the total liver volume. The volume of the left liver lobe ranged between 156 and 778 cm 3 (mean - 431, SD - 123) that is in average 29.6% of the total liver volume. The volume of segments 2+3 was 72 to 426 cm 3 (mean - 237 cm 3 , SD - 79) that is in average 16.2% of the total liver volume. The volume of the segment 4 ranged between 84 and 366 cm 3 (mean - 196, SD - 70) that is in average 13.4% of the total liver volume. CT makes possible to assess the volume of the liver, of its lobes and selected segments and it is an important modality for the classification of method of operation (segmentectomy, left hepatectomy, right hepatectomy). This method is accurate and reproducible. The liver part volumes calculated preoperatively in the majority of cases revealed to be smaller than in reality in average of 12.1%. (author)

High-Resolution Spectroscopy of He{_2}^+ Using Rydberg-Series Extrapolation and Zeeman-Decelerated Supersonic Beams of Metastable He_2

Science.gov (United States)

Jansen, Paul; Semeria, Luca; Merkt, Frederic

2016-06-01

Having only three electrons, He{_2}^+ represents a system for which highly accurate ab initio calculations are possible. The latest calculations of rovibrational energies in He{_2}^+ do not include relativistic or QED corrections but claim an accuracy of 120 MHz We have performed high-resolution Rydberg spectroscopy of metastable He_2 molecules and employed multichannel-quantum-defect-theory extrapolation techniques to determine the rotational energy-level structure in the He{_2}^+ ion. To this end, we have produced samples of metastable helium molecules in supersonic beams with velocities tunable down to 100 m/s by combining a cryogenic supersonic-beam source with a multistage Zeeman decelerator. The metastable He_2 molecules are excited to np Rydberg states using the frequency-doubled output of a pulse-amplified ring dye laser. Although the bandwidth of the laser system is too large to observe the reduction of the Doppler width resulting from deceleration, the deceleration greatly simplifies the spectral assignments because of its spin-rotational state selectivity. Our approach enabled us to determine the rotational structure of He_2 with an unprecedented accuracy of 18 MHz, to quantify the size of the relativistic and QED corrections by comparison with the results of Tung et al. and to precisely measure the rotational structure of the metastable state for comparison with the results of Focsa et al. Here, we present an extension of these measurements in which we have measured higher rotational intervals of He{_2}^+. In addition, we have replaced the pulsed UV laser by a cw UV laser and improved the resolution of the spectra by a factor of more than five. W.-C. Tung, M. Pavanello and L. Adamowicz, J. Chem. Phys. 136, 104309 (2012). P. Jansen, L. Semeria, L. Esteban Hofer, S. Scheidegger, J.A. Agner, H. Schmutz, and F. Merkt, Phys. Rev. Lett. 115, 133202 (2015). D. Sprecher, J. Liu, T. Krähenmann, M. Schäfer, and F. Merkt, J. Chem. Phys. 140, 064304 (2014). M

Prediction of drug terminal half-life and terminal volume of distribution after intravenous dosing based on drug clearance, steady-state volume of distribution, and physiological parameters of the body.

Science.gov (United States)

Berezhkovskiy, Leonid M

2013-02-01

The steady state, V(ss), terminal volume of distribution, V(β), and the terminal half-life, t(1/2), are commonly obtained from the drug plasma concentration-time profile, C(p)(t), following intravenous dosing. Unlike V(ss) that can be calculated based on the physicochemical properties of drugs considering the equilibrium partitioning between plasma and organ tissues, t(1/2) and V(β) cannot be calculated that way because they depend on the rates of drug transfer between blood and tissues. Considering the physiological pharmacokinetic model pertinent to the terminal phase of drug elimination, a novel equation that calculates t(1/2) (and consequently V(β)) was derived. It turns out that V(ss), the total body clearance, Cl, equilibrium blood-plasma concentration ratio, r; and the physiological parameters of the body such as cardiac output, and blood and tissue volumes are sufficient for determination of terminal kinetics. Calculation of t(1/2) by the obtained equation appears to be in good agreement with the experimentally observed vales of this parameter in pharmacokinetic studies in rat, monkey, dog, and human. The equation for the determination of the pre-exponent of the terminal phase of C(p)(t) is also found. The obtained equation allows to predict t(1/2) in human assuming that V(ss) and Cl were either obtained by allometric scaling or, respectively, calculated in silico or based on in vitro drug stability measurements. For compounds that have high clearance, the derived equation may be applied to calculate r just using the routine data on Cl, V(ss), and t(1/2), rather than doing the in vitro assay to measure this parameter. Copyright © 2012 Wiley Periodicals, Inc.

Intra-lesional spatial correlation of static and dynamic FET-PET parameters with MRI-based cerebral blood volume in patients with untreated glioma

Energy Technology Data Exchange (ETDEWEB)

Goettler, Jens; Preibisch, Christine [TU Muenchen, Department of Neuroradiology, Klinikum rechts der Isar, Munich (Germany); TU Muenchen, TUM Neuroimaging Center (TUM-NIC), Klinikum rechts der Isar, Munich (Germany); Lukas, Mathias; Mustafa, Mona; Schwaiger, Markus; Pyka, Thomas [TU Muenchen, Department of Nuclear Medicine, Klinikum rechts der Isar, Munich (Germany); Kluge, Anne; Kaczmarz, Stephan; Zimmer, Claus [TU Muenchen, Department of Neuroradiology, Klinikum rechts der Isar, Munich (Germany); Gempt, Jens; Ringel, Florian; Meyer, Bernhard [TU Muenchen, Department of Neurosurgery, Klinikum rechts der Isar, Munich (Germany); Foerster, Stefan [TU Muenchen, TUM Neuroimaging Center (TUM-NIC), Klinikum rechts der Isar, Munich (Germany); TU Muenchen, Department of Nuclear Medicine, Klinikum rechts der Isar, Munich (Germany); Klinikum Bayreuth, Department of Nuclear Medicine, Bayreuth (Germany)

2017-03-15

{sup 18}F-fluorethyltyrosine-(FET)-PET and MRI-based relative cerebral blood volume (rCBV) have both been used to characterize gliomas. Recently, inter-individual correlations between peak static FET-uptake and rCBV have been reported. Herein, we assess the local intra-lesional relation between FET-PET parameters and rCBV. Thirty untreated glioma patients (27 high-grade) underwent simultaneous PET/MRI on a 3 T hybrid scanner obtaining structural and dynamic susceptibility contrast sequences. Static FET-uptake and dynamic FET-slope were correlated with rCBV within tumour hotspots across patients and intra-lesionally using a mixed-effects model to account for inter-individual variation. Furthermore, maximal congruency of tumour volumes defined by FET-uptake and rCBV was determined. While the inter-individual relationship between peak static FET-uptake and rCBV could be confirmed, our intra-lesional, voxel-wise analysis revealed significant positive correlations (median r = 0.374, p < 0.0001). Similarly, significant inter- and intra-individual correlations were observed between FET-slope and rCBV. However, rCBV explained only 12% of the static and 5% of the dynamic FET-PET variance and maximal overlap of respective tumour volumes was 37% on average. Our results show that the relation between peak values of MR-based rCBV and static FET-uptake can also be observed intra-individually on a voxel basis and also applies to a dynamic FET parameter, possibly determining hotspots of higher biological malignancy. However, just a small part of the FET-PET signal variance is explained by rCBV and tumour volumes determined by the two modalities showed only moderate overlap. These findings indicate that FET-PET and MR-based rCBV provide both congruent and complimentary information on glioma biology. (orig.)

Volume variation of Gruneisen parameters of fcc transition metals

Indian Academy of Sciences (India)

Unknown

average discrepancy between the values of γ measured by various methods for 23 metals. Experimentally only the total Gruneisen parameter can be measured. The total. Gruneisen parameter is the sum of lattice, electronic and probably magnetic contribution. The letter term is present in palladium (White and Pawlok 1970) ...

Topologically-based visualization of large-scale volume data

International Nuclear Information System (INIS)

Takeshima, Y.; Tokunaga, M.; Fujishiro, I.; Takahashi, S.

2004-01-01

Due to the recent progress in the performance of computing/measurement environments and the advent of ITBL environments, volume datasets have become larger and more complicated. Although computer visualization is one of the tools to analyze such datasets effectively, it is almost impossible to adjust the visualization parameter value by trial and error without taking the feature of a given volume dataset into consideration. In this article, we introduce a scheme of topologically-based volume visualization, which is intended to choose appropriate visualization parameter values automatically through topological volume skeletonization. (author)

The E052 - GSI Experiment, Deceleration of highly charged ions by crystal channeling. (Technical notes)

International Nuclear Information System (INIS)

Kirsch, R.

2003-01-01

The report on the E052 - GSI Experiment, devoted to 'Deceleration of highly charged ions by crystal channeling' present the technical notes and the status of this experiment in 2003. The report contains 13 sections and two annexes. The sections deal with the following issues: 1. File system of the 'PC monitor' for E052 - GSI Experiment in 2003; 2. Parameters of the 'PC monitor' file system; 3. Operation of the two PCs; 3.1. Layout of goniometer remote control; 3.2. 'PC motors' side by the beam hall; 3.3. RS232 connection cabling; 3.4. RS232 configuration on the COM1 ports of the two PCs; 4. Motor connection; 4.1. SubD-25 acquisition PC monitor arm on 'COM1'; 4.2. Motors step by step feeding side SubD-25 on 'COM1'; 4.3. Distribution of digital step by step control signals; 4.5. Upper an lower goniometer connection; 4.6. Rotation and inclination outer goniometer connection; 4.7. Ultra vacuum inner rotation and inclination connection; 5. Motor characteristics; 5.1. Upstream and downstream; 5.2. Rotation; 5.3 Inclination; 5.4. Feedings; 6. Goniometer in-beam positioning; 6.1. Height fine motor positioning; 6.2. Side manual positioning; 7. Goniometer movements; 8. Crystals and electron detection; 8.1. General layout; 8.2. 1 μm Si(100) crystal; 8.3. 33 μm Si(100) crystal; 8.4. Crystal mounting; 8.5. Electron detection; 9. Reference laser positioning of angular movements; 10. Beam track and collimators upstream the target; 11. User manual - Monitoring programme; 11.Start scanning program (GSIscan.exe); 11.2. SCANNING the crystal (Scan Control window); 11.3. MOVING THE GONIOMETER MANUALY (goniometer control window); 11.4. USING THE COUNTERS (counter display window); 11.5. MULTISCALER PLOT DISPLAY; 11.6. SELECT ACTIVE PLOT; 11.7. CURSORS; 11.8. STATISTICS; 11.9. Y SCALE change; 11.10. PLOT view and hide counter; 11.11. SAVE multiscaler spectra; 11.12. PRINT plot; 12. Simplified acquisition electronic setup; 13. The 'PC motors' software; 13.1. The code structure; 13

Theses. Beam studies for the CERN antiproton decelerator and a new interpretation of the resonance theory for betatron motion

Energy Technology Data Exchange (ETDEWEB)

De Ninno, G

1999-07-01

The two parts of the thesis are a mission-oriented task devoted to solve some practical problems of the Antiproton Decelerator (AD) project at CERN, and a theoretical study leading to a new method for representing and compensating betatron resonances. The AD is a new machine (at the moment under commissioning at CERN) that will allow the collection and the deceleration of an antiproton beam from 3.5 GeV/c down to 100 MeV/c (the momentum favoured for the foreseen physics experiments). The need to employ the AD magnets over a wide range required a careful study of their characteristics. The presence of a solenoid inside the AD electron cooling device generates linear coupling between the transverse degrees of freedom of the single-particle motion. Coupling can lead to operational problems and therefore a compensation scheme had tobe designed. The long-standing problem has been solved of how to establish a relationship between the two standard methods for dealing with linear coupling: the matrix approach and the Hamiltonian approach. The bridge was built by including in the Hamiltonian approach in the high frequency part of the perturbative Hamiltonian due to coupling. The procedure was generalised to the nonlinear case and, a new method was proposed for dealing both with linear and nonlinear resonances. (author)

Theses. Beam studies for the CERN antiproton decelerator and a new interpretation of the resonance theory for betatron motion

International Nuclear Information System (INIS)

De Ninno, G.

1999-01-01

The two parts of the thesis are a mission-oriented task devoted to solve some practical problems of the Antiproton Decelerator (AD) project at CERN, and a theoretical study leading to a new method for representing and compensating betatron resonances. The AD is a new machine (at the moment under commissioning at CERN) that will allow the collection and the deceleration of an antiproton beam from 3.5 GeV/c down to 100 MeV/c (the momentum favoured for the foreseen physics experiments). The need to employ the AD magnets over a wide range required a careful study of their characteristics. The presence of a solenoid inside the AD electron cooling device generates linear coupling between the transverse degrees of freedom of the single-particle motion. Coupling can lead to operational problems and therefore a compensation scheme had to be designed. The long-standing problem has been solved of how to establish a relationship between the two standard methods for dealing with linear coupling: the matrix approach and the Hamiltonian approach. The bridge was built by including in the Hamiltonian approach in the high frequency part of the perturbative Hamiltonian due to coupling. The procedure was generalised to the nonlinear case and, a new method was proposed for dealing both with linear and nonlinear resonances. (author)

Development of new platforms for hydrodynamic instability and asymmetry measurements in deceleration phase of indirectly-driven implosions on NIF

Science.gov (United States)

Pickworth, Louisa

2017-10-01

Hydrodynamic instabilities and asymmetries are a major obstacle in the quest to achieve ignition as they cause pre-existing capsule perturbations to grow and ultimately quench the fusion burn in experiments at the National Ignition Facility (NIF). This talk will review recent developments of the experimental platforms and techniques to measure high-mode instabilities and low-mode asymmetries in the deceleration phase of implosions. These new platforms provide a natural link between the acceleration-phase experiments and neutron performance of layered deuterium-tritium implosions. In one innovative technique, self-emission from the hot spot was enhanced with argon dopant to ``self-backlight'' the shell in-flight around peak compression. Experiments with pre-imposed 2-D perturbations measured instability growth factors, while experiments with 3-D, ``native-roughness'' perturbations measured shell integrity in the deceleration phase of implosions. In a complimentary technique, the inner surface of the shell, along with its low-mode asymmetries and high-mode perturbations were visualized in implosions using x-ray emission of a high-Z dopant added to the inner surface of the capsule. These new measurements were instrumental in revealing unexpected surprises and providing improved understanding of the role of instabilities and asymmetries on implosion performance. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Atomic collision studies at moderate projectile velocities using highly charged, decelerated heavy ions from the GSI-UNILAC

International Nuclear Information System (INIS)

Mokler, P.H.; Hoffmann, D.H.H.; Schoenfeldt, W.A.; Maor, D.

1984-01-01

Beams of highly ionized, very heavy atoms at moderate velocities have been produced at the UNILAC using the acceleration-stripping-deceleration method. The available ion species range from Kr 33+ to U 66+ in the energy region between 2 and 5 MeV/u. A survey on first experiments at GSI using these moderate velocity, few electron, heavy ion beams is given. The effectiveness of the method is demonstrated for Xesup(q+)-Xe collision experiments with 41 <= q <= 45. Results on vacancy transfer between inner quasimolecular levels for close collisions, and on distant collision electron capture are reported. (orig.)

Slip Ratio Estimation and Regenerative Brake Control for Decelerating Electric Vehicles without Detection of Vehicle Velocity and Acceleration

Science.gov (United States)

Suzuki, Toru; Fujimoto, Hiroshi

In slip ratio control systems, it is necessary to detect the vehicle velocity in order to obtain the slip ratio. However, it is very difficult to measure this velocity directly. We have proposed slip ratio estimation and control methods that do not require the vehicle velocity with acceleration. In this paper, the slip ratio estimation and control methods are proposed without detecting the vehicle velocity and acceleration when it is decelerating. We carried out simulations and experiments by using an electric vehicle to verify the effectiveness of the proposed method.

Design parameters and source terms: Volume 1, Design parameters: Revision 0

International Nuclear Information System (INIS)

1987-09-01

The Design Parameters and Source Terms Document was prepared in accordance with DOE request and to provide data for the environmental impact study to be performed in the future for the Deaf Smith County, Texas site for a nuclear waste repository in salt. This document updates a previous unpublished report to the level of the Site Characterization Plan - Conceptual Design Report, SCP-CDR. The previous unpublished SCC Study identified the data needs for the Environmental Assessment effort for seven possible salt repository sites

Late dysphagia after IMRT for head and neck cancer and correlation with dose–volume parameters

International Nuclear Information System (INIS)

Mortensen, Hanna R.; Jensen, Kenneth; Aksglæde, Karin; Behrens, Marie; Grau, Cai

2013-01-01

Background and purpose: Many head and neck cancer (HNC) survivors experience diminished quality of life due to radiation-induced dysphagia. The aim of this study was to investigate frequency, intensity and dose–volume dependency for late dysphagia in HNC patients treated with curative IMRT. Materials and methods: Candidates for the study were 294 patients treated with primary IMRT from 2006 to 2010; a total of 259 patients accepted to participate by answering the EORTC QLQ-C30 and H and N35 questionnaires. A total of 65 patients were further examined with modified barium swallow (MBS) and saliva collection. Data on patient, tumor and treatment characteristics were prospectively recorded in the DAHANCA database. Dose–volume histograms (DVH) of swallowing-related structures were retrospectively analyzed. Results: QoL data showed low degree of dysphagia (QoL subscales scores of 17 and below) compared to objective measures. The most frequent swallowing dysfunction was retention; penetration and aspiration was less common. In general, objective measurements and observer-assessed late dysphagia correlated with dose to pharyngeal constrictor muscles (PCM), whereas QoL endpoints correlated with DVH parameters in the glottis/supraglottic larynx. Both xerostomia and dysphagia has been reduced after introduction of IMRT. Conclusions: Radiation-induced dysphagia is still important, with a high degree of retention and penetration. Introduction of parotid-sparing IMRT has reduced the severity of dysphagia, primarily through a major reduction in xerostomia. Dose–response relationships were found for specific dysphagia endpoints

A cosmographic analysis of the transition to acceleration using SN-Ia and BAO

Energy Technology Data Exchange (ETDEWEB)

Muthukrishna, Daniel; Parkinson, David, E-mail: d.muthukrishna@uq.edu.au, E-mail: d.parkinson@uq.edu.au [School of Mathematics and Physics, University of Queensland, Brisbane, QLD 4072 (Australia)

2016-11-01

We explore the distance-redshift relation using a cosmographic methodology, and show how the cosmographic parameters can be used to determine the redshift of transition from deceleration to acceleration. Such a transition at a low redshift occupies only a small region of the available parameter space, and the prior assumption of an early period of deceleration can significantly change the posterior constraints. We use available type Ia Supernovae (SN-Ia) and Baryon Acoustic Oscillation (BAO) data sets to determine the cosmographic deceleration q {sub 0}, jerk j {sub 0}, snap s {sub 0} and lerk l {sub 0} parameters. The parameters are consistent with the ΛCDM model for a flat universe within 2-sigma. We derive constraints on the redshift of transition from deceleration to acceleration for the different expansions, and find z {sub acc} > 0.14 at 95% confidence in the most conservative case.

Significant correlation of P-wave parameters with left atrial volume index and left ventricular diastolic function.

Science.gov (United States)

Tsai, Wei-Chung; Lee, Kun-Tai; Wu, Ming-Tsang; Chu, Chih-Sheng; Lin, Tsung-Hsien; Hsu, Po-Chao; Su, Ho-Ming; Voon, Wen-Chol; Lai, Wen-Ter; Sheu, Sheng-Hsiung

2013-07-01

The 12-lead electrocardiogram (ECG) is a commonly used tool to access left atrial enlargement, which is a marker of left ventricular diastolic dysfunction (LVDD). The aim of this study was to evaluate any association of the P-wave measurements in ECG with left atrial volume (LAV) index and LVDD. This study enrolled 270 patients. In this study, 4 ECG P-wave parameters corrected by heart rate, that is, corrected P-wave maximum duration (PWdurMaxC), corrected P-wave dispersion (PWdisperC), corrected P-wave area (PWareaC) and corrected mean P-wave duration (meanPWdurC), were measured. LAV and left ventricular diastolic parameters were measured from echocardiography. LVDD was defined as a pseudonormal or restrictive mitral inflow pattern. The 4 P-wave parameters were significantly correlated with the LAV index after adjusting for age, sex, diabetes, hypertension, coronary artery disease, body mass index and diastolic blood pressure in multivariate analysis. The standardized β coefficients of PWdurMaxC, PWdisperC, meanPWdurC and PWareaC were 0.338, 0.298, 0.215 and 0.296, respectively. The 4 P-wave parameters were also significantly correlated with LVDD after multivariate logistic regression analysis. The odds ratios (95% confidence intervals) of PWdurMaxC, PWdisperC, meanPWdurC and PWareaC were 1.03 (1.01-1.04), 1.02 (1.04-1.04), 1.04 (1.02-1.07) and 1.01 (1.00-1.02), respectively. This study demonstrated that PWdurMaxC, PWdisperC, meanPWdurC and PWareaC were important determinants of the LAV index and LVDD. Therefore, screening patients by means of the 12-lead ECG may be helpful in identifying a high-risk group of increased LAV index and LVDD.

Channeling, volume reflection, and volume capture study of electrons in a bent silicon crystal

Directory of Open Access Journals (Sweden)

T. N. Wistisen

2016-07-01

Full Text Available We present the experimental data and analysis of experiments conducted at SLAC National Accelerator Laboratory investigating the processes of channeling, volume-reflection and volume-capture along the (111 plane in a strongly bent quasimosaic silicon crystal. These phenomena were investigated at 5 energies: 3.35, 4.2, 6.3, 10.5, and 14.0 GeV with a crystal with bending radius of 0.15 m, corresponding to curvatures of 0.053, 0.066, 0.099, 0.16, and 0.22 times the critical curvature, respectively. Based on the parameters of fitting functions we have extracted important parameters describing the channeling process such as the dechanneling length, the angle of volume reflection, the surface transmission, and the widths of the distribution of channeled particles parallel and orthogonal to the plane.

Commissioning status of the decelerator test beam line in CTF3

CERN Document Server

Adli, E; Lillestol, R; Olvegaard, M; Syratchev, I; Carrillo, D; Toral, F; Faus-Golfe, A; Garcia-Garrigos, J J; Kubyshin, Y; Montoro, G

2010-01-01

The CLIC Test Facility (CTF3) at CERN was constructed by the CTF3 collaboration to study the feasibility of the concepts for a compact linear collider. The test beam line (TBL) recently added to the CTF3 machine was designed to study the CLIC decelerator beam dynamics and 12 GHz power production. The beam line consists of a FODO lattice with high precision BPM’s and quadrupoles on movers for precise beam alignment. A total of 16 Power Extraction and Transfer Structures (PETS) will be installed in between the quadrupoles to extract 12 GHz power from the drive beam provided by the CTF3 machine. The CTF3 drive beam with a bunch-train length of 140 ns, 12 GHz bunch repetition frequency and an average current over the train of up to 28 A will be injected into the test beam line. Each PETS structure will produce 135 MW of 12 GHz power at nominal current. The beam will have lost more than 50 % of its initial energy of 150 MeV at the end of the beam line and will contain particles with energies between 65 MeV and 1...

Soft SUSY breaking parameters and RG running of squark and slepton masses in large volume Swiss Cheese compactifications

International Nuclear Information System (INIS)

Misra, Aalok; Shukla, Pramod

2010-01-01

We consider type IIB large volume compactifications involving orientifolds of the Swiss Cheese Calabi-Yau WCP 4 [1,1,1,6,9] with a single mobile space-time filling D3-brane and stacks of D7-branes wrapping the 'big' divisor Σ B (as opposed to the 'small' divisor usually done in the literature thus far) as well as supporting D7-brane fluxes. After reviewing our proposal of (Misra and Shukla, 2010) for resolving a long-standing tension between large volume cosmology and phenomenology pertaining to obtaining a 10 12 GeV gravitino in the inflationary era and a TeV gravitino in the present era, and summarizing our results of (Misra and Shukla, 2010) on soft supersymmetry breaking terms and open-string moduli masses, we discuss the one-loop RG running of the squark and slepton masses in mSUGRA-like models (using the running of the gaugino masses) to the EW scale in the large volume limit. Phenomenological constraints and some of the calculated soft SUSY parameters identify the D7-brane Wilson line moduli as the first two generations/families of squarks and sleptons and the D3-brane (restricted to the big divisor) position moduli as the two Higgses for MSSM-like models at TeV scale. We also discuss how the obtained open-string/matter moduli make it easier to impose FCNC constraints, as well as RG flow of off-diagonal squark mass(-squared) matrix elements.

Soft SUSY breaking parameters and RG running of squark and slepton masses in large volume Swiss Cheese compactifications

Science.gov (United States)

Misra, Aalok; Shukla, Pramod

2010-03-01

We consider type IIB large volume compactifications involving orientifolds of the Swiss Cheese Calabi-Yau WCP[1,1,1,6,9] with a single mobile space-time filling D3-brane and stacks of D7-branes wrapping the “big” divisor ΣB (as opposed to the “small” divisor usually done in the literature thus far) as well as supporting D7-brane fluxes. After reviewing our proposal of [1] (Misra and Shukla, 2010) for resolving a long-standing tension between large volume cosmology and phenomenology pertaining to obtaining a 10 GeV gravitino in the inflationary era and a TeV gravitino in the present era, and summarizing our results of [1] (Misra and Shukla, 2010) on soft supersymmetry breaking terms and open-string moduli masses, we discuss the one-loop RG running of the squark and slepton masses in mSUGRA-like models (using the running of the gaugino masses) to the EW scale in the large volume limit. Phenomenological constraints and some of the calculated soft SUSY parameters identify the D7-brane Wilson line moduli as the first two generations/families of squarks and sleptons and the D3-brane (restricted to the big divisor) position moduli as the two Higgses for MSSM-like models at TeV scale. We also discuss how the obtained open-string/matter moduli make it easier to impose FCNC constraints, as well as RG flow of off-diagonal squark mass(-squared) matrix elements.

The Research of Car-Following Model Based on Real-Time Maximum Deceleration

Directory of Open Access Journals (Sweden)

Longhai Yang

2015-01-01

Full Text Available This paper is concerned with the effect of real-time maximum deceleration in car-following. The real-time maximum acceleration is estimated with vehicle dynamics. It is known that an intelligent driver model (IDM can control adaptive cruise control (ACC well. The disadvantages of IDM at high and constant speed are analyzed. A new car-following model which is applied to ACC is established accordingly to modify the desired minimum gap and structure of the IDM. We simulated the new car-following model and IDM under two different kinds of road conditions. In the first, the vehicles drive on a single road, taking dry asphalt road as the example in this paper. In the second, vehicles drive onto a different road, and this paper analyzed the situation in which vehicles drive from a dry asphalt road onto an icy road. From the simulation, we found that the new car-following model can not only ensure driving security and comfort but also control the steady driving of the vehicle with a smaller time headway than IDM.

ACTIVATION PARAMETERS AND EXCESS THERMODYANAMIC ...

African Journals Online (AJOL)

Applying these data, viscosity-B-coefficients, activation parameters (Δμ10≠) and (Δμ20≠) and excess thermodynamic functions, viz., excess molar volume (VE), excess viscosity, ηE and excess molar free energy of activation of flow, (GE) were calculated. The value of interaction parameter, d, of Grunberg and Nissan ...

Desiccator Volume: A Vital Yet Ignored Parameter in CaCO3 Crystallization by the Ammonium Carbonate Diffusion Method

Directory of Open Access Journals (Sweden)

Joe Harris

2017-07-01

Full Text Available Employing the widely used ammonium carbonate diffusion method, we demonstrate that altering an extrinsic parameter—desiccator size—which is rarely detailed in publications, can alter the route of crystallization. Hexagonally packed assemblies of spherical magnesium-calcium carbonate particles or spherulitic aragonitic particles can be selectively prepared from the same initial reaction solution by simply changing the internal volume of the desiccator, thereby changing the rate of carbonate addition and consequently precursor formation. This demonstrates that it is not merely the quantity of an additive which can control particle morphogenesis and phase selectivity, but control of other often ignored parameters are vital to ensure adequate reproducibility.

Assessment and monitoring of flow limitation and other parameters from flow/volume loops.

Science.gov (United States)

Dueck, R

2000-01-01

Flow/volume (F/V) spirometry is routinely used for assessing the type and severity of lung disease. Forced vital capacity (FVC) and timed vital capacity (FEV1) provide the best estimates of airflow obstruction in patients with asthma, chronic obstructive pulmonary disease (COPD) and emphysema. Computerized spirometers are now available for early home recognition of asthma exacerbation in high risk patients with severe persistent disease, and for recognition of either infection or rejection in lung transplant patients. Patients with severe COPD may exhibit expiratory flow limitation (EFL) on tidal volume (VT) expiratory F/V (VTF/V) curves, either with or without applying negative expiratory pressure (NEP). EFL results in dynamic hyperinflation and persistently raised alveolar pressure or intrinsic PEEP (PEEPi). Hyperinflation and raised PEEPi greatly enhance dyspnea with exertion through the added work of the threshold load needed to overcome raised pleural pressure. Esophageal (pleural) pressure monitoring may be added to VTF/V loops for assessing the severity of PEEPi: 1) to optimize assisted ventilation by mask or via endotracheal tube with high inspiratory flow rates to lower I:E ratio, and 2) to assess the efficacy of either pressure support ventilation (PSV) or low level extrinsic PEEP in reducing the threshold load of PEEPi. Intraoperative tidal volume F/V loops can also be used to document the efficacy of emphysema lung volume reduction surgery (LVRS) via disappearance of EFL. Finally, the mechanism of ventilatory constraint can be identified with the use of exercise tidal volume F/V loops referenced to maximum F/V loops and static lung volumes. Patients with severe COPD show inspiratory F/V loops approaching 95% of total lung capacity, and flow limitation over the entire expiratory F/V curve during light levels of exercise. Surprisingly, patients with a history of congestive heart failure may lower lung volume towards residual volume during exercise

On the surviving fraction in irradiated multicellular tumour spheroids: calculation of overall radiosensitivity parameters, influence of hypoxia and volume effects

International Nuclear Information System (INIS)

Horas, Jorge A; Olguin, Osvaldo R; Rizzotto, Marcos G

2005-01-01

We model the heterogeneous response to radiation of multicellular tumour spheroids assuming position- and volume-dependent radiosensitivity. We propose a method to calculate the overall radiosensitivity parameters to obtain the surviving fraction of tumours. A mathematical model of a spherical tumour with a hypoxic core and a viable rim which is a caricature of a real tumour is constructed. The model is embedded in a two-compartment linear-quadratic (LQ) model, assuming a mixed bivariated Gaussian distribution to attain the radiosensitivity parameters. Ergodicity, i.e., the equivalence between ensemble and volumetric averages is used to obtain the overall radiosensitivities for the two compartments. We obtain expressions for the overall radiosensitivity parameters resulting from the use of both a linear and a nonlinear dependence of the local radiosensitivity with position. The model's results are compared with experimental data of surviving fraction (SF) for multicellular spheroids of different sizes. We make one fit using only the smallest spheroid data and we are able to predict the SF for the larger spheroids. These predictions are acceptable particularly using bounded sensitivities. We conclude with the importance of taking into account the contribution of clonogenic hypoxic cells to radiosensitivity and with the convenience of using bounded local sensitivities to predict overall radiosensitivity parameters

Dose-Volume Parameters of the Corpora Cavernosa Do Not Correlate With Erectile Dysfunction After External Beam Radiotherapy for Prostate Cancer: Results From a Dose-Escalation Trial

International Nuclear Information System (INIS)

Wielen, Gerard J. van der; Hoogeman, Mischa S.; Dohle, Gert R.; Putten, Wim L.J. van; Incrocci, Luca

2008-01-01

Purpose: To analyze the correlation between dose-volume parameters of the corpora cavernosa and erectile dysfunction (ED) after external beam radiotherapy (EBRT) for prostate cancer. Methods and Materials: Between June 1997 and February 2003, a randomized dose-escalation trial comparing 68 Gy and 78 Gy was conducted. Patients at our institute were asked to participate in an additional part of the trial evaluating sexual function. After exclusion of patients with less than 2 years of follow-up, ED at baseline, or treatment with hormonal therapy, 96 patients were eligible. The proximal corpora cavernosa (crura), the superiormost 1-cm segment of the crura, and the penile bulb were contoured on the planning computed tomography scan and dose-volume parameters were calculated. Results: Two years after EBRT, 35 of the 96 patients had developed ED. No statistically significant correlations between ED 2 years after EBRT and dose-volume parameters of the crura, the superiormost 1-cm segment of the crura, or the penile bulb were found. The few patients using potency aids typically indicated to have ED. Conclusion: No correlation was found between ED after EBRT for prostate cancer and radiation dose to the crura or penile bulb. The present study is the largest study evaluating the correlation between ED and radiation dose to the corpora cavernosa after EBRT for prostate cancer. Until there is clear evidence that sparing the penile bulb or crura will reduce ED after EBRT, we advise to be careful in sparing these structures, especially when this involves reducing treatment margins

PREMIXED FLAME PROPAGATION AND MORPHOLOGY IN A CONSTANT VOLUME COMBUSTION CHAMBER

Energy Technology Data Exchange (ETDEWEB)

Hariharan, A; Wichman, IS

2014-06-04

This work presents an experimental and numerical investigation of premixed flame propagation in a constant volume rectangular channel with an aspect ratio of six (6) that serves as a combustion chamber. Ignition is followed by an accelerating cusped finger-shaped flame-front. A deceleration of the flame is followed by the formation of a "tulip"-shaped flame-front. Eventually, the flame is extinguished when it collides with the cold wall on the opposite channel end. Numerical computations are performed to understand the influence of pressure waves, instabilities, and flow field effects causing changes to the flame structure and morphology. The transient 2D numerical simulation results are compared with transient 3D experimental results. Issues discussed are the appearance of oscillatory motions along the flame front and the influences of gravity on flame structure. An explanation is provided for the formation of the "tulip" shape of the premixed flame front.

Change in volume parameters induced by neoadjuvant chemotherapy provide accurate prediction of overall survival after resection in patients with oesophageal cancer

Energy Technology Data Exchange (ETDEWEB)

Tamandl, Dietmar; Fueger, Barbara; Kinsperger, Patrick; Haug, Alexander; Ba-Ssalamah, Ahmed [Medical University of Vienna, Department of Biomedical Imaging and Image-Guided Therapy, Comprehensive Cancer Center GET-Unit, Vienna (Austria); Gore, Richard M. [University of Chicago Pritzker School of Medicine, Department of Radiology, Chicago, IL (United States); Hejna, Michael [Medical University of Vienna, Department of Internal Medicine, Division of Medical Oncology, Comprehensive Cancer Center GET-Unit, Vienna (Austria); Paireder, Matthias; Schoppmann, Sebastian F. [Medical University of Vienna, Department of Surgery, Upper-GI-Service, Comprehensive Cancer Center GET-Unit, Vienna (Austria)

2016-02-15

To assess the prognostic value of volumetric parameters measured with CT and PET/CT in patients with neoadjuvant chemotherapy (NACT) and resection for oesophageal cancer (EC). Patients with locally advanced EC, who were treated with NACT and resection, were retrospectively analysed. Data from CT volumetry and {sup 18} F-FDG PET/CT (maximum standardized uptake [SUVmax], metabolic tumour volume [MTV], and total lesion glycolysis [TLG]) were recorded before and after NACT. The impact of volumetric parameter changes induced by NACT (MTV{sub RATIO}, TLG{sub RATIO}, etc.) on overall survival (OS) was assessed using a Cox proportional hazards model. Eighty-four patients were assessed using CT volumetry; of those, 50 also had PET/CT before and after NACT. Low post-treatment CT volume and thickness, MTV, TLG, and SUVmax were all associated with longer OS (p < 0.05), as were CTthickness{sub RATIO}, MTV{sub RATIO}, TLG{sub RATIO}, and SUVmax{sub RATIO} (p < 0.05). In the multivariate analysis, only MTV{sub RATIO} (Hazard ratio, HR 2.52 [95 % Confidence interval, CI 1.33-4.78], p = 0.005), TLG{sub RATIO} (HR 3.89 [95%CI 1.46-10.34], p = 0.006), and surgical margin status (p < 0.05), were independent predictors of OS. MTV{sub RATIO} and TLG{sub RATIO} are independent prognostic factors for survival in patients after NACT and resection for EC. (orig.)

Relationship between macular ganglion cell complex parameters and visual field parameters after tumor resection in chiasmal compression.

Science.gov (United States)

Ohkubo, Shinji; Higashide, Tomomi; Takeda, Hisashi; Murotani, Eiji; Hayashi, Yasuhiko; Sugiyama, Kazuhisa

2012-01-01

To evaluate the relationship between macular ganglion cell complex (GCC) parameters and visual field (VF) parameters in chiasmal compression and the potential for GCC parameters in order to predict the short-term postsurgical VF. Twenty-three eyes of 12 patients with chiasmal compression and 33 control eyes were studied. All patients underwent transsphenoidal tumor resection. Before surgery a 3D scan of the macula was taken using spectral-domain optical coherence tomography. All patients underwent Humphrey 24-2 VF testing after surgery. Spearman's rank correlation coefficients were used to evaluate the relationship between the GCC parameters and VF parameters [mean deviation (MD), pattern standard deviation]. Coefficients of determination (R2) were calculated using linear regression. Average thickness in the patients was significantly thinner than that of controls. Average thickness, global loss volume and focal loss volume (FLV) significantly correlated with the MD. We observed the greatest R2 between FLV and MD. Examining the macular GCC was useful for evaluating structural damage in patients with chiasmal compression. Preoperative GCC parameters, especially FLV, may be useful in predicting visual function following surgical decompression of chiasmal compression.

Intermittent Auscultation in Labor: Could It Be Missing Many Pathological (Late) Fetal Heart Rate Decelerations? Analytical Review and Rationale for Improvement Supported by Clinical Cases

Science.gov (United States)

Sholapurkar, Shashikant L.

2015-01-01

Intermittent auscultation (IA) of fetal heart rate (FHR) is recommended/preferred in low risk labors. Its usage even in developed countries is poised to increase because of perceived benefit of reduction in operative intervention and some disillusionment with the cardiotocography (CTG). Many national guidelines have stipulated regimes (frequency/timing) of IA based on level IV evidence. These tend to get faithfully and exactingly followed. It was observed that deliveries of many unexpectedly asphyxiated infants occurred despite rigorously performed and documented IA compliant with the guidelines. This triggered a reappraisal of the robustness of IA leading to this focused review supplemented by two anonymized cases. It concludes that the current methodology of IA may be flawed in that it poses a risk of missing many or most late (pathological) FHR decelerations, one of the foremost goals of IA. This is because many late decelerations reach their nadir before the end of the contraction. Thus the currently recommended auscultation of FHR for 60 seconds after the contraction by all national guidelines seemed to encompass their “recovery” phase and appeared to be misinterpreted as normal FHR or even as a reassuring accelerative pattern in the clinical practice. A recent recommendation of recording of the FHR as a single figure (rather than a range) does not remedy this anomaly and seems even less informative. It would be better to auscultate FHR before and after the contractions (or contraction to contraction) and take the FHR just before the contraction as the baseline FHR and interpret the FHR after contraction in the context of this baseline. This relatively simple improvement would detect most late FHR decelerations thus ameliorating the risk and significantly enhancing the patient safety. PMID:26566404

On the relationship between input parameters in two-mass vocal-fold model with acoustical coupling an signal parameters of the glottal flow

NARCIS (Netherlands)

van Hirtum, Annemie; Lopez, Ines; Hirschberg, Abraham; Pelorson, Xavier

2003-01-01

In this paper the sensitivity of the two-mass model with acoustical coupling to the model input-parameters is assessed. The model-output or the glottal volume air flow is characterised by signal-parameters in the time-domain. The influence of changing input-parameters on the signal-parameters is

General least-squares fitting procedures to minimize the volume of a hyperellipsoid

International Nuclear Information System (INIS)

Wadlinger, E.A.

1979-01-01

Several methods for determining the shape parameters, which in two dimensions are the Courant-Snyder parameters, and the volume of an ellipse or hyperellipse that represent a set of phase-space points in a two or more dimensional hyperspace are presented. The ellipse parameters are useful for matching a beam to an accelerating or transport system and in studies of emittance growth. The fitting procedure minimizes the total volume of a hyperellipse by adjusting the ellipse shape parameters. The total volume is the sum of the individual particle volumes defined by the hyperellipse that passes through the phase-space point of a particle. A two-dimensional space is considered first; the results are then generalized to higher dimensions. Computer programs using these techniques were written. 1 figure

Rapid tachyphylaxis of the glucagon-like peptide 1-induced deceleration of gastric emptying in humans

DEFF Research Database (Denmark)

Nauck, Michael A; Kemmeries, Guido; Holst, Jens Juul

2011-01-01

DESIGN AND METHODS: Nine healthy volunteers (25 ± 4 years old, BMI: 24.6 ± 4.7 kg/m(2)) were examined with intravenous infusion of GLP-1 (0.8 pmol · kg(-1) · min(-1)) or placebo over 8.5 h. Two liquid mixed meals were administered at a 4-h interval. Gastric emptying was determined, and blood samples were...... drawn frequently. RESULTS: GLP-1 decelerated gastric emptying significantly more after the first meal compared with the second meal (P = 0.01). This was associated with reductions in pancreatic polypeptide levels (marker of vagal activation) after the first but not the second meal (P ... but increased after the second test meal (P gastric emptying is subject to rapid tachyphylaxis at the level of vagal nervous activation. As a consequence, postprandial glucose control by GLP-1 is attenuated after its chronic administration...

Changes in haematological parameters of Tilapia guineensis ...

African Journals Online (AJOL)

Changes in haematological parameters of Tilapia guineensis exposed to different concentrations of detergent under laboratory conditions. ... The experiment evaluated sub-lethal effect of the exposure on some haematological parameters including haemoglobin (Hb), red blood cell (RBC), packed cell volume (PCV), white ...

Prognostic Value of Volume-Based {sup 18}F-Fluorodeoxyglucose PET/CT Parameters in Patients with Clinically Node-Negative Oral Tongue Squamous Cell Carcinoma

Energy Technology Data Exchange (ETDEWEB)

Lee, Su Jin [Dept. of Nuclear Medicine, Ajou University School of Medicine, Suwon (Korea, Republic of); Choi, Joon Young; Lee, Hwan Joo; Hyun, Seung Hyup; Moon, Seung Hwan; Kim, Byung Tae [Dept. of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Baek, Chung Hwan; Son, Young Ik [Dept. of Otorhinolaryngology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

2012-11-15

To evaluate the prognostic value of volume-based metabolic parameters measured with {sup 18}F-fluorodeoxyglucose ({sup 18}F-FDG) positron emission tomography (PET) in patients with clinically node-negative (cN0) oral tongue squamous cell carcinoma (OTSCC) as compared with other prognostic factors. In this study, we included a total of 57 patients who had been diagnosed with cN0 tongue cancer by radiologic, ({sup 18}F-FDG PET/CT, and physical examinations. The maximum standardized uptake value (SUVmax), average SUV (SUVavg), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) for primary tumors were measured with ({sup 18}F-FDG PET. The prognostic significances of these parameters and other clinical variables were assessed by Cox proportional hazards regression analysis. In the univariate analysis, pathological node (pN) stage, American Joint Committee on Cancer (AJCC) stage, SUVmax, SUVavg, MTV, and TLG were significant predictors for survival. On a multivariate analysis, pN stage (hazard ratio = 10.555, p = 0.049), AJCC stage (hazard ratio = 13.220, p = 0.045), and MTV (hazard ratio = 2.698, p 0.033) were significant prognostic factors in cN0 OTSCC patients. The patients with MTV {>=} 7.78 cm{sup 3} showed a worse prognosis than those with MTV < 7.78 cm{sup 3} (p = 0.037). The MTV of primary tumor as a volumetric parameter of ({sup 18}F-FDG PET, in addition to pN stage and AJCC stage, is an independent prognostic factor for survival in cN0 OTSCC.

Risk Factors for Neovascular Glaucoma After Proton Beam Therapy of Uveal Melanoma: A Detailed Analysis of Tumor and Dose–Volume Parameters

International Nuclear Information System (INIS)

Mishra, Kavita K.; Daftari, Inder K.; Weinberg, Vivian; Cole, Tia; Quivey, Jeanne M.; Castro, Joseph R.; Phillips, Theodore L.; Char, Devron H.

2013-01-01

Purpose: To determine neovascular glaucoma (NVG) incidence and identify contributing tumor and dosing factors in uveal melanoma patients treated with proton beam radiation therapy (PBRT). Methods and Materials: A total of 704 PBRT patients treated by a single surgeon (DHC) for uveal melanoma (1996-2010) were reviewed for NVG in our prospectively maintained database. All patients received 56 GyE in 4 fractions. Median follow-up was 58.3 months. Analyses included the Kaplan-Meier method to estimate NVG distributions, univariate log–rank tests, and Cox's proportional hazards multivariate analysis using likelihood ratio tests to identify independent risk factors of NVG among patient, tumor, and dose–volume histogram parameters. Results: The 5-year PBRT NVG rate was 12.7% (95% confidence interval [CI] 10.2%-15.9%). The 5-year rate of enucleation due to NVG was 4.9% (95% CI 3.4%-7.2%). Univariately, the NVG rate increased significantly with larger tumor diameter (P 30% of the lens or ciliary body received ≥50% dose (≥28 GyE), there was a higher probability of NVG (P 0%-30% vs >30%) (P=.01), and optic nerve length treated to ≥90% Dose (≤1 mm vs >1 mm) (P=.02). Conclusions: Our current PBRT patients experience a low rate of NVG and resultant enucleation compared with historical data. The present analysis shows that tumor height, diameter, and anterior as well as posterior critical structure dose–volume parameters may be used to predict NVG risk

Parameters, Volume 23, Number 4, Winter 1993-94

Science.gov (United States)

1993-01-01

international groups, the failure of the US-supported ESAF to defeat the underdog FMLN made the guerrilla movement the undeclared winner of this bout...to Win: Special Forces at War. London, Eng.: Arms and Armour (Dist. in US by Sterling Publishing Co.), 1993. 214 pp. $27.50. 128 Parameters 1M n Fuller

SAFE Journal. Volume 34, Number 1, Fall 2006

National Research Council Canada - National Science Library

Darrah, Mark I; Benton, Jeani; DeWald, Sandra; Darrah, James

2006-01-01

... + Gz Vertical Deceleration Mathematical Simulation of the Human Ventilatory Response during and Altitude Chamber Physiological Training Profile First Hand Witnesses of Sled Testing Over the Past Forty Years Then and Now...

Design parameters and source terms: Volume 3, Source terms

International Nuclear Information System (INIS)

1987-10-01

The Design Parameters and Source Terms Document was prepared in accordance with DOE request and to provide data for the environmental impact study to be performed in the future for the Deaf Smith County, Texas site for a nuclear waste repository in salt. This document updates a previous unpublished report by Stearns Catalytic Corporation (SCC), entitled ''Design Parameters and Source Terms for a Two-Phase Repository in Salt,'' 1985, to the level of the Site Characterization Plan - Conceptual Design Report. The previous unpublished SCC Study identifies the data needs for the Environmental Assessment effort for seven possible Salt Repository sites. 11 refs., 9 tabs

The influence of tyre characteristics on measures of rolling performance during cross-country mountain biking.

Science.gov (United States)

Macdermid, Paul William; Fink, Philip W; Stannard, Stephen R

2015-01-01

This investigation sets out to assess the effect of five different models of mountain bike tyre on rolling performance over hard-pack mud. Independent characteristics included total weight, volume, tread surface area and tread depth. One male cyclist performed multiple (30) trials of a deceleration field test to assess reliability. Further tests performed on a separate occasion included multiple (15) trials of the deceleration test and six fixed power output hill climb tests for each tyre. The deceleration test proved to be reliable as a means of assessing rolling performance via differences in initial and final speed (coefficient of variation (CV) = 4.52%). Overall differences between tyre performance for both deceleration test (P = 0.014) and hill climb (P = 0.032) were found, enabling significant (P < 0.0001 and P = 0.049) models to be generated, allowing tyre performance prediction based on tyre characteristics. The ideal tyre for rolling and climbing performance on hard-pack surfaces would be to decrease tyre weight by way of reductions in tread surface area and tread depth while keeping volume high.

A reference frame for blood volume in children and adolescents

Directory of Open Access Journals (Sweden)

Donckerwolcke Raymond

2006-02-01

Full Text Available Abstract Background Our primary purpose was to determine the normal range and variability of blood volume (BV in healthy children, in order to provide reference values during childhood and adolescence. Our secondary aim was to correlate these vascular volumes to body size parameters and pubertal stages, in order to determine the best normalisation parameter. Methods Plasma volume (PV and red cell volume (RCV were measured and F-cell ratio was calculated in 77 children with idiopathic nephrotic syndrome in drug-free remission (mean age, 9.8 ± 4.6 y. BV was calculated as the sum of PV and RCV. Due to the dependence of these values on age, size and sex, all data were normalised for body size parameters. Results BV normalised for lean body mass (LBM did not differ significantly by sex (p Conclusion LBM was the anthropometric index most closely correlated to vascular fluid volumes, independent of age, gender and pubertal stage.

On the relationship between input parameters in the two-mass vocal-fold model with acoustical coupling and signal parameters of the glottal flow

NARCIS (Netherlands)

Hirtum, van A.; Lopez Arteaga, I.; Hirschberg, A.; Pelorson, X.

2003-01-01

In this paper the sensitivity of the two-mass model with acoustical coupling to the model input-parameters is assessed. The model-output or the glottal volume air flow is characterised by signal-parameters in the time-domain. The influence of changing input-parameters on the signal-parameters is

Radiocardiographic determination of the stroke volume and of the heart minute volume in athletes

Energy Technology Data Exchange (ETDEWEB)

Sattler, R; Stoll, W [Friedrich-Schiller-Universitaet, Jena (German Democratic Republic). Radiologische Klinik

1981-11-01

Radiocardiography, a novel radioisotope method for the problemless determination of many cardiodynamic parameters which can be applied also at given physical exercise is presented. On the basis of stroke volume and heart minute volume values from 35 athletes practising different sports and of a comparison with normal values reported in the literature, differences in the cardiac adaptation and the function of athletic hearts and so-called normal hearts are pointed out. The stroke volume of endurance-trained athletes exceeds that of untrained individuals by 30-40 ml. Under exercise the increase of the stroke volume is considerably greater in endurance athletes than in individuals practising other sports or in untrained subjects. At rest the values of the heart minute volume are almost the same in athletes and untrained individuals. Under exercise the heart minute volume of endurance athletes (40 l/min) is nearly twice that of untrained individuals (volume reserve of the athlete).

Radiocardiographic determination of the stroke volume and of the heart minute volume in athletes

International Nuclear Information System (INIS)

Sattler, R.; Stoll, W.

1981-01-01

Radiocardiography, a novel radioisotope method for the problemless determination of many cardiodynamic parameters which can be applied also at given physical exercise is presented. On the basis of stroke volume and heart minute volume values from 35 athletes practising different sports and of a comparison with normal values reported in the literature, differences in the cardiac adaptation and the function of athletic hearts and so-called normal hearts are pointed out. The stroke volume of endurance-trained athetes exceed that of untrained individuals by 30-40 ml. Under exercise the increase of the stroke volume is considerably greater in endurance athletes than in individuals practising other sports or in untrained subjects. At rest the values of the heart minute volume are almost the same in athletes and untrained individuals. Under exercise the heart minute volume of endurance athletes (40 l/min) is nearly twice that of untrained individuals (volume reserve of the athlete). (author)

A dimensionless dynamic contrast enhanced MRI parameter for intra-prostatic tumour target volume delineation: initial comparison with histology

Science.gov (United States)

Hrinivich, W. Thomas; Gibson, Eli; Gaed, Mena; Gomez, Jose A.; Moussa, Madeleine; McKenzie, Charles A.; Bauman, Glenn S.; Ward, Aaron D.; Fenster, Aaron; Wong, Eugene

2014-03-01

Purpose: T2 weighted and diffusion weighted magnetic resonance imaging (MRI) show promise in isolating prostate tumours. Dynamic contrast enhanced (DCE)-MRI has also been employed as a component in multi-parametric tumour detection schemes. Model-based parameters such as Ktrans are conventionally used to characterize DCE images and require arterial contrast agent (CR) concentration. A robust parameter map that does not depend on arterial input may be more useful for target volume delineation. We present a dimensionless parameter (Wio) that characterizes CR wash-in and washout rates without requiring arterial CR concentration. Wio is compared to Ktrans in terms of ability to discriminate cancer in the prostate, as demonstrated via comparison with histology. Methods: Three subjects underwent DCE-MRI using gadolinium contrast and 7 s imaging temporal resolution. A pathologist identified cancer on whole-mount histology specimens, and slides were deformably registered to MR images. The ability of Wio maps to discriminate cancer was determined through receiver operating characteristic curve (ROC) analysis. Results: There is a trend that Wio shows greater area under the ROC curve (AUC) than Ktrans with median AUC values of 0.74 and 0.69 respectively, but the difference was not statistically significant based on a Wilcoxon signed-rank test (p = 0.13). Conclusions: Preliminary results indicate that Wio shows potential as a tool for Ktrans QA, showing similar ability to discriminate cancer in the prostate as Ktrans without requiring arterial CR concentration.

The analysis of correlation between changes of myocardial enzymes level in serum before and after radiation and dose-volume histogram parameters of the heart

International Nuclear Information System (INIS)

Ding Xiuping; Li Hongjun; Li Baosheng; Wang Dongqing

2012-01-01

Objective: To analyze the correlation between the changes of myocardial enzyme level in serum before and after radiotherapy and dose - volume histogram (DVH) parameters of the heart. Methods: A total of 102 patients with 68 cases of lung cancer and 34 cases of esophageal cancer were recruited. All patients received three-dimensional conformal radiotherapy (3DCRT) or intensity-modulated radiotherapy (IMRT), with the radiation beams passing through the heart. Aspartate aminotransferase (AST), creatine kinase (CK), creatine kinase isozyme (CK-MB), lactate dehydrogenase (LDH), α-hydroxybutyrate dehydrogenase (α-HBDH) were determined in the serum before and after radiotherapy. All the enzyme levels before and after radiotherapy were compared through paired t-test. Independent sample t-test was conducted between sub-groups. And the dose-volume histogram (DVH) parameters of the heart were calculated (the volume percentage of heart receiving dose equal to or exceeding x Gy (V x ). The correlation between myocardial enzyme level and DVH parameters was analyzed through Pearson method. Results: Serum AST, CK-MB, LDH, α-HBDH levels increased significantly after radiotherapy (19.42: 27.89, 14.72:19.57, 178.80 : 217.57, 140.32 : 176.25, t =-3.39 - -6.92, all P=0.000). In Group IMRT, significant correlations between the increase of myocardial enzyme concentration and DVH parameters of the heart are found, AST with V 20 , V 25 , V 30 of heart ( r=0.302 - 0.431, P =0.039 - 0.003), CK with V 30 of heart (r=0.345, P=0.013), and CK-MB, LDH, α-HBDH with V 25 , V 30 (r=0.465 -0.376, P=0.001-0.005). In Group CRT, there are significant correlations between changes of CK-MB, LDH level and V 30 of heart (r =0.330, 0.274, P=0.014, 0.033), α-HBDH and V 25 , V 30 , and V 35 of heart (r=0.270-0.331, P=0.046-0.014). When the irradiation dose was more than 50 Gy, significant correlations were found between the concentration changes of AST, LDH, α-HBDH and V 25 , V 30 of heart (r=0

Treatment of Locally Advanced Vaginal Cancer With Radiochemotherapy and Magnetic Resonance Image-Guided Adaptive Brachytherapy: Dose–Volume Parameters and First Clinical Results

International Nuclear Information System (INIS)

Dimopoulos, Johannes C.A.; Schmid, Maximilian P.; Fidarova, Elena; Berger, Daniel; Kirisits, Christian; Pötter, Richard

2012-01-01

Purpose: To investigate the clinical feasibility of magnetic resonance image-guided adaptive brachytherapy (IGABT) for patients with locally advanced vaginal cancer and to report treatment outcomes. Methods and Materials: Thirteen patients with vaginal cancer were treated with external beam radiotherapy (45–50.4 Gy) plus IGABT with or without chemotherapy. Distribution of International Federation of Gynecology and Obstetrics stages among patients were as follows: 4 patients had Stage II cancer, 5 patients had Stage III cancer, and 4 patients had Stage IV cancer. The concept of IGABT as developed for cervix cancer was transferred and adapted for vaginal cancer, with corresponding treatment planning and reporting. Doses were converted to the equivalent dose in 2 Gy, applying the linear quadratic model (α/β = 10 Gy for tumor; α/β = 3 for organs at risk). Endpoints studied were gross tumor volume (GTV), dose-volume parameters for high-risk clinical target volume (HRCTV), and organs at risk, local control (LC), adverse side effects, and survival. Results: The mean GTV (± 1 standard deviation) at diagnosis was 45.3 (±30) cm 3 , and the mean GTV at brachytherapy was 10 (±14) cm 3 . The mean D90 for the HRCTV was 86 (±13) Gy. The mean D2cc for bladder, urethra, rectum, and sigmoid colon were 80 (±20) Gy, 76 (±16) Gy, 70 (±9) Gy, and 60 (±9) Gy, respectively. After a median follow-up of 43 months (range, 19–87 months), one local recurrence and two distant metastases cases were observed. Actuarial LC and overall survival rates at 3 years were 92% and 85%. One patient with Stage IVA and 1 patient with Stage III disease experienced fistulas (one vesicovaginal, one rectovaginal), and 1 patient developed periurethral necrosis. Conclusions: The concept of IGABT, originally developed for treating cervix cancer, appears to be applicable to vaginal cancer treatment with only minor adaptations. Dose-volume parameters for HRCTV and organs at risk are in a comparable

Treatment of Locally Advanced Vaginal Cancer With Radiochemotherapy and Magnetic Resonance Image-Guided Adaptive Brachytherapy: Dose-Volume Parameters and First Clinical Results

Energy Technology Data Exchange (ETDEWEB)

Dimopoulos, Johannes C.A. [Department of Radiation Oncology, Metropolitan Hospital, Athens (Greece); Schmid, Maximilian P., E-mail: maximilian.schmid@akhwien.at [Department of Radiotherapy, Medical University of Vienna, Vienna (Austria); Fidarova, Elena; Berger, Daniel; Kirisits, Christian; Poetter, Richard [Department of Radiotherapy, Medical University of Vienna, Vienna (Austria)

2012-04-01

Purpose: To investigate the clinical feasibility of magnetic resonance image-guided adaptive brachytherapy (IGABT) for patients with locally advanced vaginal cancer and to report treatment outcomes. Methods and Materials: Thirteen patients with vaginal cancer were treated with external beam radiotherapy (45-50.4 Gy) plus IGABT with or without chemotherapy. Distribution of International Federation of Gynecology and Obstetrics stages among patients were as follows: 4 patients had Stage II cancer, 5 patients had Stage III cancer, and 4 patients had Stage IV cancer. The concept of IGABT as developed for cervix cancer was transferred and adapted for vaginal cancer, with corresponding treatment planning and reporting. Doses were converted to the equivalent dose in 2 Gy, applying the linear quadratic model ({alpha}/{beta} = 10 Gy for tumor; {alpha}/{beta} = 3 for organs at risk). Endpoints studied were gross tumor volume (GTV), dose-volume parameters for high-risk clinical target volume (HRCTV), and organs at risk, local control (LC), adverse side effects, and survival. Results: The mean GTV ({+-} 1 standard deviation) at diagnosis was 45.3 ({+-}30) cm{sup 3}, and the mean GTV at brachytherapy was 10 ({+-}14) cm{sup 3}. The mean D90 for the HRCTV was 86 ({+-}13) Gy. The mean D2cc for bladder, urethra, rectum, and sigmoid colon were 80 ({+-}20) Gy, 76 ({+-}16) Gy, 70 ({+-}9) Gy, and 60 ({+-}9) Gy, respectively. After a median follow-up of 43 months (range, 19-87 months), one local recurrence and two distant metastases cases were observed. Actuarial LC and overall survival rates at 3 years were 92% and 85%. One patient with Stage IVA and 1 patient with Stage III disease experienced fistulas (one vesicovaginal, one rectovaginal), and 1 patient developed periurethral necrosis. Conclusions: The concept of IGABT, originally developed for treating cervix cancer, appears to be applicable to vaginal cancer treatment with only minor adaptations. Dose-volume parameters for HRCTV and

Motorcycle On-Road Driving Parameters Influencing Fuel Consumption and Emissions on Congested Signalized Urban Corridor

Directory of Open Access Journals (Sweden)

Atthapol Seedam

2017-01-01

Full Text Available This study aims to find the on-road driving parameters influencing fuel consumption and emissions of motorcycle driving on a congested signalized urban corridor. A motorcycle onboard measurement system was developed to measure instantaneously and continuously record on-road driving data, including speed-time profile, emissions, and fuel consumption, by the second. The test motorcycles were driven by 30 sample motorcyclists on a signalized urban corridor in Khon Kaen City, Thailand, to collect their on-road driving behavior during the morning peak period. Cluster analysis was applied to analyze collected driving data and to categorize the drivers by level of fuel consumption and on-road driver behavior. The on-road driving parameter influencing fuel consumption and emissions was then determined. Results revealed that proportion of idle time significantly influenced fuel consumption and emissions of motorcycle driving on a congested signalized urban corridor, though aggressive driving behavior, hard acceleration and deceleration, did not have the same kind of influence.

Steric parameters and excess properties of hydroxamic acids

International Nuclear Information System (INIS)

Patre, Sandhya; Thakur, Piyush; Pande, Rama

2012-01-01

Graphical abstract: Plot of excess molar volume, V E , vs X 2 of (A) PBHA in DMF, (B) PMNHA in DMF, and (C) PNHA in DMF, at (■), 298.15 K; (▪), 303.15 K; (▪), 308.15 K; and (▪), 313.15 K. Highlights: ► Apparent molar volume indicates greater solute–solvent interactions. ► Excess properties show higher dispersion force in solution than pure solvent. ► Excess parameters suggest strong solute–solvent and solute–solute interactions. ► Limiting apparent molar expansibilities instigate highly hydrophobic characters. ► Hepler’s constant suggest the structure promoter nature of hydroxamic acids. - Abstract: Steric parameters of N-phenylbenzo-, N-phenyl-4-methyl-3-nitrobenzo-, and N-phenyl-4-nitrobenzo-, hydroxamic acids were measured in N,N-dimethylformamide (DMF) as a function of their concentrations at T = (298.15, 303.15, 308.15, and 313.15) K. The apparent molar volume (V φ ), limiting apparent molar volume (V φ 0 ) at infinite dilution and the slope (S V ∗ ) are calculated from the experimental values of density (ρ) by applying the Masson’s equation. The apparent molar expansibility at infinite dilution (φ E 0 ), molar volume (V) and the excess molar volume (V E ) are also computed. The refractive indices (n) have been used to calculate the steric parameters, viz. molar refraction (R M ), polarizability (α) and excess molar refraction (R) of these molecules. The results show the strong solute–solvent interactions present in the system and thus, help to explore the molecular structure.

The clinical significance of detection to heart rate deceleration capacity and heart rate variability in patients with chronic heart failure

Directory of Open Access Journals (Sweden)

Jiang-rong Zhou

2015-01-01

Full Text Available Objective: To study the change of heart rate deceleration capacity ( DC and heart rate variability in patients with chronic heart failure (CHF and its relationship with left ventricular ejection fraction (LVEF. Methods: DC, LVEF, time and frequency domain parameters of HRV were measured in 66 patients with CHF and 34 healthy adults (control group by using 24h Holter recordings and Echocardiography. The standard deviation of normal R-R intervals( SDNN, squares of differences between adjacent NN intervals ( RMSSD，low frequency power( LFn and high frequency power( HFn and the changes of LVEF were compared between  the two groups，the relationship between DC，LVEF and HRV were studied in patients with CHF. Results: The median value of DC in the patients with CHF was significantly lower than that in control group( 3.1 ± 2.4 ms vs 7.2 ± 1.3 ms，P <0.01．Incidence of abnormal DC in the CHF group was 57.5%，which was significantly higher than that in the control group (P <0.01．The HRV index, including SDNN、RMSSD、LFn、HFn, in the CHF group was significantly lower than that in normal control group (P < 0.01. Significant positive correlation between HRV index and LVEF were confirmed (P < 0.01. Conclusions: DC and HRV index are lower in patients with CHF and have a good correlation with the left ventricular ejection fraction.

A SUB-GRID VOLUME-OF-FLUIDS (VOF) MODEL FOR MIXING IN RESOLVED SCALE AND IN UNRESOLVED SCALE COMPUTATIONS

International Nuclear Information System (INIS)

Vold, Erik L.; Scannapieco, Tony J.

2007-01-01

A sub-grid mix model based on a volume-of-fluids (VOF) representation is described for computational simulations of the transient mixing between reactive fluids, in which the atomically mixed components enter into the reactivity. The multi-fluid model allows each fluid species to have independent values for density, energy, pressure and temperature, as well as independent velocities and volume fractions. Fluid volume fractions are further divided into mix components to represent their 'mixedness' for more accurate prediction of reactivity. Time dependent conversion from unmixed volume fractions (denoted cf) to atomically mixed (af) fluids by diffusive processes is represented in resolved scale simulations with the volume fractions (cf, af mix). In unresolved scale simulations, the transition to atomically mixed materials begins with a conversion from unmixed material to a sub-grid volume fraction (pf). This fraction represents the unresolved small scales in the fluids, heterogeneously mixed by turbulent or multi-phase mixing processes, and this fraction then proceeds in a second step to the atomically mixed fraction by diffusion (cf, pf, af mix). Species velocities are evaluated with a species drift flux, ρ i u di = ρ i (u i -u), used to describe the fluid mixing sources in several closure options. A simple example of mixing fluids during 'interfacial deceleration mixing with a small amount of diffusion illustrates the generation of atomically mixed fluids in two cases, for resolved scale simulations and for unresolved scale simulations. Application to reactive mixing, including Inertial Confinement Fusion (ICF), is planned for future work.

Variability of left ventricular ejection fraction and volumes with quantitative gated SPECT: influence of algorithm, pixel size and reconstruction parameters in small and normal-sized hearts

International Nuclear Information System (INIS)

Hambye, Anne-Sophie; Vervaet, Ann; Dobbeleir, Andre

2004-01-01

Several software packages are commercially available for quantification of left ventricular ejection fraction (LVEF) and volumes from myocardial gated single-photon emission computed tomography (SPECT), all of which display a high reproducibility. However, their accuracy has been questioned in patients with a small heart. This study aimed to evaluate the performances of different software and the influence of modifications in acquisition or reconstruction parameters on LVEF and volume measurements, depending on the heart size. In 31 patients referred for gated SPECT, 64 2 and 128 2 matrix acquisitions were consecutively obtained. After reconstruction by filtered back-projection (Butterworth, 0.4, 0.5 or 0.6 cycles/cm cut-off, order 6), LVEF and volumes were computed with different software [three versions of Quantitative Gated SPECT (QGS), the Emory Cardiac Toolbox (ECT) and the Stanford University (SU-Segami) Medical School algorithm] and processing workstations. Depending upon their end-systolic volume (ESV), patients were classified into two groups: group I (ESV>30 ml, n=14) and group II (ESV 2 to 128 2 were associated with significantly larger volumes as well as lower LVEF values. Increasing the filter cut-off frequency had the same effect. With SU-Segami, a larger matrix was associated with larger end-diastolic volumes and smaller ESVs, resulting in a highly significant increase in LVEF. Increasing the filter sharpness, on the other hand, had no influence on LVEF though the measured volumes were significantly larger. (orig.)

Testing for one Generalized Linear Single Order Parameter

DEFF Research Database (Denmark)

Ellegaard, Niels Langager; Christensen, Tage Emil; Dyre, Jeppe

We examine a linear single order parameter model for thermoviscoelastic relaxation in viscous liquids, allowing for a distribution of relaxation times. In this model the relaxation of volume and entalpy is completely described by the relaxation of one internal order parameter. In contrast to prior...... work the order parameter may be chosen to have a non-exponential relaxation. The model predictions contradict the general consensus of the properties of viscous liquids in two ways: (i) The model predicts that following a linear isobaric temperature step, the normalized volume and entalpy relaxation...... responses or extrapolate from measurements of a glassy state away from equilibrium. Starting from a master equation description of inherent dynamics, we calculate the complex thermodynamic response functions. We device a way of testing for the generalized single order parameter model by measuring 3 complex...

Investigation of venous blood cells parameters among 1180 healthy people in Tianjin area

International Nuclear Information System (INIS)

Jiang Liping; Hao Jianxiu; Li Jin; Xing Zhiwei; Zhao Xinran; Jiang Bo; Wang Xiaoguang; Jiang Enhai

2013-01-01

Objective: To investigate the reference values of 18 parameters of venous blood cells among healthy adults in Tianjin area. Methods: The values of 18 parameters of venous blood from 1180 healthy adults in Tianjin area were measured by Sysmex KX-21 hematology analyzer and the results were analyzed. Results: The statistical analysis of the test reveals that significant differences exist in most parameters of venous blood cells according to the gender and age of people. Except the parameters of mean corpuscular volume, lymphocytes percentage, mean platelet volume, platelet distribution width,there were significant differences in the remaining parameters between the males group and the females group. Except the parameters of white blood count,platelet count, mean corpuscular hemoglobin, neutrophil percentage,absolute neutrophil count, mean platelet volume, platelet distribution width, there were significant differences in the remaining parameters between the old male group and the adult male group. Except the parameters of white blood count, mean corpuscular volume, mean corpuscular hemoglobin, there was no significant difference in the remaining parameters between the old female group and the adult female group. Conclusions: There are some differences between the findings and the reference range provided by the National Guide to Clinical laboratory Procedure. Therefore, it is necessary for laboratory to establish the reference values of venous blood cells according to concrete conditions. (authors)

Hydrocephalus in mice following X-irradiation at early gestational stage. Possibly due to persistent deceleration of cell proliferation

Energy Technology Data Exchange (ETDEWEB)

Aolad, H.M.; Inouye, Minoru; Darmanto, W.; Hayasaka, Shizu; Murata, Yoshiharu [Nagoya Univ. (Japan). Research Inst. of Environmental Medicine

2000-09-01

The pathogenesis of X-ray-induced congenital hydrocephalus was studied. Pregnant mice were irradiated at 1.4 Gy on gestational day 7 (G7). Four hours after irradiation, extensive cell death was evident in the neuroepithelium and underlying mesoderm of the head region, and proliferating cell nuclear antigen (PCNA)-immunoreactive cells almost disappeared. Embryos with thinner lamina terminalis of the telecephalon, when compared with that of the control, were found in the irradiated group on G9. As early as G11 in some irradiated embryos the telencephalic wall was thinner and lateral ventricles were larger than those of the control. The choroid invagination from the lamina terminalis began on G11 in the control brain, but not in the affected brain. During the following development, fetuses with readily apparent hydrocephalus were consistently found among irradiated fetuses. In these brains the brain mantle was thinner, the corpus striatum and thalamic regions were smaller, and lateral ventricles were larger than those of the control. Even on G11 and G13 the frequencies of PCNA-positive cells in the brain mantle and other brain regions were lower in the hydrocephalic brain than those of the control, suggesting a decelerated proliferation of successive cell generations following exposure to X-rays. The cerebral aqueduct was open in the hydrocephalic brain during the fetal period when the lateral ventricles were dilated. The head was vaulted after birth but the cerebral aqueduct was not completely occluded even in these animals. These findings suggested that cell death in the neuroepithelium followed by a persistent deceleration of neural cell proliferation, resulting in the hypoplasia of brain parenchyma with compensatory ventricular dilatation, is important for the establishment of hydrocephalus. (author)

Hydrocephalus in mice following X-irradiation at early gestational stage. Possibly due to persistent deceleration of cell proliferation

International Nuclear Information System (INIS)

Aolad, H.M.; Inouye, Minoru; Darmanto, W.; Hayasaka, Shizu; Murata, Yoshiharu

2000-01-01

The pathogenesis of X-ray-induced congenital hydrocephalus was studied. Pregnant mice were irradiated at 1.4 Gy on gestational day 7 (G7). Four hours after irradiation, extensive cell death was evident in the neuroepithelium and underlying mesoderm of the head region, and proliferating cell nuclear antigen (PCNA)-immunoreactive cells almost disappeared. Embryos with thinner lamina terminalis of the telecephalon, when compared with that of the control, were found in the irradiated group on G9. As early as G11 in some irradiated embryos the telencephalic wall was thinner and lateral ventricles were larger than those of the control. The choroid invagination from the lamina terminalis began on G11 in the control brain, but not in the affected brain. During the following development, fetuses with readily apparent hydrocephalus were consistently found among irradiated fetuses. In these brains the brain mantle was thinner, the corpus striatum and thalamic regions were smaller, and lateral ventricles were larger than those of the control. Even on G11 and G13 the frequencies of PCNA-positive cells in the brain mantle and other brain regions were lower in the hydrocephalic brain than those of the control, suggesting a decelerated proliferation of successive cell generations following exposure to X-rays. The cerebral aqueduct was open in the hydrocephalic brain during the fetal period when the lateral ventricles were dilated. The head was vaulted after birth but the cerebral aqueduct was not completely occluded even in these animals. These findings suggested that cell death in the neuroepithelium followed by a persistent deceleration of neural cell proliferation, resulting in the hypoplasia of brain parenchyma with compensatory ventricular dilatation, is important for the establishment of hydrocephalus. (author)

Influence of technical parameters on epicardial fat volume quantification at cardiac CT.

Science.gov (United States)

Bucher, Andreas M; Joseph Schoepf, U; Krazinski, Aleksander W; Silverman, Justin; Spearman, James V; De Cecco, Carlo N; Meinel, Felix G; Vogl, Thomas J; Geyer, Lucas L

2015-06-01

To systematically analyze the influence of technical parameters on quantification of epicardial fat volume (EATV) at cardiac CT. 153 routine cardiac CT data sets were analyzed using three-dimensional pericardial border delineation. Three image series were reconstructed per patient: (a) CTAD: coronary CT angiography (CTA), diastolic phase; (b) CTAS: coronary CTA, systolic phase; (c) CaScD: non-contrast CT, diastolic phase. EATV was calculated using three different upper thresholds (-15HU, -30 HU, -45HU). Repeated measures ANOVA, Spearman's rho, and Bland Altman plots were used. Mean EATV differed between all three image series at a -30HU threshold (CTAD 87.2 ± 38.5 ml, CTAS 90.9 ± 37.7 ml, CaScD 130.7 ± 49.5 ml, PEATV of diastolic and systolic CTA reconstructions did not differ significantly (P=0.225). Mean EATV for contrast enhanced CTA at a -15HU threshold (CTAD15 102.4 ± 43.6 ml, CTAS15 105.3 ± 42.3 ml) could be approximated most closely by non-contrast CT at -45HU threshold (CaScD45 105.3 ± 40.8 ml). The correlation was excellent: CTAS15-CTAD15, rho=0.943; CTAD15-CaScD45, rho=0.905; CTAS15-CaScD45, rho=0.924; each PEATV can differ substantially between contrast enhanced and non-contrast CT studies, which can be reconciled by threshold modification. Heart cycle phase does not significantly influence EATV measurements. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The features of radiation induced lung fibrosis related with dosimetric parameters

International Nuclear Information System (INIS)

Oh, Young-Taek; Noh, O Kyu; Jang, Hyunsoo; Chun, Mison; Park, Kyung Joo; Park, Kwang Joo; Kim, Mi-Hwa; Park, Hae-Jin

2012-01-01

Background and purpose: Radiation induced lung fibrosis (RILF) is a major complication after lung irradiation and is very important for long term quality of life and could result in fatal respiratory insufficiency. However, there has been little information on dosimetric parameters for radiotherapy planning in the aspect of RILF. The features of RILF related with dosimetric parameters were evaluated. Methods and materials: Forty-eight patients with non-small cell lung carcinoma who underwent post-operative radiation therapy (PORT) without adjuvant chemotherapy were analyzed. The degree of lung fibrosis was estimated by fibrosis volume and the dosimetric parameters were calculated from the plan of 3-dimensional conformal radiotherapy. Results: The fibrosis volume and V-dose as dosimetric parameters showed significant correlation and the correlation coefficient ranged from 0.602 to 0.683 (P < 0.01). The degree of the correlation line was steeper as the dose increase and threshold dose was not found. Mean lung dose (MLD) showed strong correlation with fibrosis volume (correlation coefficient = 0.726, P < 0.01). Conclusions: The fibrosis volume is continuously increased with V-dose as the reference dose increases. MLD is useful as a single parameter for comparing rival plans in the aspect of RILF.

Infrared spectroscopy of the remnant of Nova Sco 2014: a symbiotic star with too little circumstellar matter to decelerate the ejecta

Science.gov (United States)

Munari, U.; Banerjee, D. P. K.

2018-03-01

Pre-outburst 2MASS and WISE photometry of Nova Sco 2014 (V1534 Sco) has suggested the presence of a cool giant at the location of the nova in the sky. The spectral evolution recorded for the nova did not, however, support a direct partnership because no flash-ionized wind and no deceleration of the ejecta were observed, contrary to the behaviour displayed by other novae which erupted within symbiotic binaries like V407 Cyg or RS Oph. We have therefore obtained 0.8-2.5 μm spectra of the remnant of Nova Sco 2014 in order to ascertain if a cool giant is indeed present and if it is physically associated with the nova. The spectrum shows the presence of a M6III giant, reddened by E(B - V) = 1.20, displaying the typical and narrow emission-line spectrum of a symbiotic star, including He I 1.0830 μm with a deep P-Cyg profile. This makes Nova Sco 2014 a new member of the exclusive club of novae that erupt within a symbiotic binary. Nova Sco 2014 shows that a nova erupting within a symbiotic binary does not always come with a deceleration of the ejecta, contrary to the common belief. Many other similar systems may lay hidden in past novae, especially in those that erupted prior to the release of the 2MASS all-sky infrared survey, which could be profitably cross-matched now against them.

Uniform relativistic universe models with pressure. Part 2. Observational tests

International Nuclear Information System (INIS)

Krempec, J.; Krygier, B.

1977-01-01

The magnitude-redshift and angular diameter-redshift relations are discussed for the uniform (homogeneous and isotropic) relativistic Universe models with pressure. The inclusion of pressure into the energy-momentum tensor has given larger values of the deceleration parameter q. An increase of the deceleration parameter has led to the brightening of objects as well as to a little larger angular diameters. (author)

Comparison of different contouring definitions of the rectum as organ at risk (OAR) and dose-volume parameters predicting rectal inflammation in radiotherapy of prostate cancer: which definition to use?

Science.gov (United States)

Nitsche, Mirko; Brannath, Werner; Brückner, Matthias; Wagner, Dirk; Kaltenborn, Alexander; Temme, Nils; Hermann, Robert M

2017-02-01

The objective of this retrospective planning study was to find a contouring definition for the rectum as an organ at risk (OAR) in curative three-dimensional external beam radiotherapy (EBRT) for prostate cancer (PCa) with a predictive correlation between the dose-volume histogram (DVH) and rectal toxicity. In a pre-study, the planning CT scans of 23 patients with PCa receiving definitive EBRT were analyzed. The rectum was contoured according to 13 different definitions, and the dose distribution was correlated with the respective rectal volumes by generating DVH curves. Three definitions were identified to represent the most distinct differences in the shapes of the DVH curves: one anatomical definition recommended by the Radiation Therapy Oncology Group (RTOG) and two functional definitions based on the target volume. In the main study, the correlation between different relative DVH parameters derived from these three contouring definitions and the occurrence of rectal toxicity during and after EBRT was studied in two consecutive collectives. The first cohort consisted of 97 patients receiving primary curative EBRT and the second cohort consisted of 66 patients treated for biochemical recurrence after prostatectomy. Rectal toxicity was investigated by clinical investigation and scored according to the Common Terminology Criteria for Adverse Events. Candidate parameters were the volume of the rectum, mean dose, maximal dose, volume receiving at least 60 Gy (V 60 ), area under the DVH curve up to 25 Gy and area under the DVH curve up to 75 Gy in dependence of each chosen rectum definition. Multivariable logistic regression considered other clinical factors such as pelvine lymphatics vs local target volume, diabetes, prior rectal surgery, anticoagulation or haemorrhoids too. In Cohort 1 (primary EBRT), the mean rectal volumes for definitions "RTOG", planning target volume "(PTV)-based" and "PTV-linked" were 100 cm 3 [standard deviation (SD) 43 cm 3 ], 60�

Dynamic studies of multiple configurations of CERN's Antiproton Decelerator Target core under proton beam impact

CERN Document Server

AUTHOR|(CDS)2248381

Antiprotons, like many other exotic particles, are produced by impacting high energy proton beams onto fixed targets. At the European Organization for Nuclear Research (CERN), this is done in the Antiproton Decelerator (AD) Facility. The engineering challenges related to the design of an optimal configuration of the AD-Target system derive from the extremely high energy depositions reached in the very thin target core as a consequence of each proton beam impact. A new target design is foreseen for operation after 2021, triggering multiple R&D activities since 2013 for this purpose. The goal of the present Master Thesis is to complement these activities with analytical and numerical calculations, delving into the phenomena associated to the dynamic response of the target core. In this context, two main studies have been carried out. First, the experimental data observed in targets subjected to low intensity proton pulses was cross-checked with analytical and computational methods for modal analysis, applie...

Independent Orbiter Assessment (IOA): Assessment of the landing/deceleration (LDG/DEC) subsystem FMEA/CIL

Science.gov (United States)

Odonnell, R. A.; Weissinger, D.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Landing/Deceleration (LDG/DEC) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison is provided through additional analysis as required. This report documents the results of that comparison for the Orbiter LDG/DEC hardware. The IOA product for the LDG/DEC analysis consisted of 259 failure mode worksheets that resulted in 124 potential critical items being identified. Comparison was made to the NASA baseline which consisted of 267 FMEA's and 120 CIL items. This comparison produced agreement on all but 75 FMEA's which caused differences in 51 CIL items.

Governing parameters and dynamics of turbulent spray atomization from modern GDI injectors

International Nuclear Information System (INIS)

Moon, Seoksu; Li, Tianyun; Sato, Kiyotaka; Yokohata, Hideaki

2017-01-01

Understanding the governing parameters and dynamics of turbulent spray atomization is essential for the advancement of fuel injection technologies, but no concrete understandings have been derived previously. The current study investigates the governing parameters and dynamics of turbulent spray atomization by experimental observations of near-nozzle spray phenomena using an X-ray imaging technique. The effects of critical injection parameters such as fuel property, injection pressure and ambient density on near-nozzle liquid feature size and velocity distributions were extensively studied using three injection nozzles having different levels of initial flow turbulence and dispersion. Based on the results, the governing parameters and dynamics of turbulent spray atomization and the issues on the advanced fuel injection control of modern engines were thoroughly discussed. The results showed that fuel and injection pressure effects on spray atomization became insignificant from a critical Weber number which decreased upon the increase in initial flow turbulence and dispersion. The increase in ambient density increased the resultant droplet size at downstream due to the faster deceleration of spray which brought the atomization termination location closer to the nozzle exit. The spray atomization was terminated at the location of ca. 72% exit velocity regardless of the injection condition. - Highlights: • Governing parameters and dynamics of turbulent spray atomization are investigated. • Fuel and injection pressure effects on atomization are saturated from critical We. • High ambient density increases drop sizes due to faster termination of atomization. • Atomization terminates when the spray velocity decays to ca. 72% of exit velocity. • Strategies for improvement of current injection technologies are discussed.

Early Site Permit Demonstration Program: Plant parameters envelope report. Volume 1

Energy Technology Data Exchange (ETDEWEB)

1993-03-01

The Early Site Permit (ESP) Demonstration Program is the nuclear industry`s initiative for piloting the early resolution of siting-related issues before the detailed design proceedings of the combined operating license review. The ESP Demonstration Program consists of three phases. The plant parameters envelopes task is part of Phase 1, which addresses the generic review of applicable federal regulations and develops criteria for safety and environmental assessment of potential sites. The plant parameters envelopes identify parameters that characterize the interface between an ALWR design and a potential site, and quantify the interface through values selected from the Utility Requirements Documents, vendor design information, or engineering assessments. When augmented with site-specific information, the plant parameters envelopes provide sufficient information to allow ESPs to be granted based on individual ALWR design information or enveloping design information for the evolutionary, passive, or generic ALWR plants. This document is expected to become a living document when used by future applicants.

A concept of volume rendering guided search process to analyze medical data set.

Science.gov (United States)

Zhou, Jianlong; Xiao, Chun; Wang, Zhiyan; Takatsuka, Masahiro

2008-03-01

This paper firstly presents an approach of parallel coordinates based parameter control panel (PCP). The PCP is used to control parameters of focal region-based volume rendering (FRVR) during data analysis. It uses a parallel coordinates style interface. Different rendering parameters represented with nodes on each axis, and renditions based on related parameters are connected using polylines to show dependencies between renditions and parameters. Based on the PCP, a concept of volume rendering guided search process is proposed. The search pipeline is divided into four phases. Different parameters of FRVR are recorded and modulated in the PCP during search phases. The concept shows that volume visualization could play the role of guiding a search process in the rendition space to help users to efficiently find local structures of interest. The usability of the proposed approach is evaluated to show its effectiveness.

WIPP Compliance Certification Application calculations parameters. Part 1: Parameter development

International Nuclear Information System (INIS)

Howarth, S.M.

1997-01-01

The Waste Isolation Pilot Plant (WIPP) in southeast New Mexico has been studied as a transuranic waste repository for the past 23 years. During this time, an extensive site characterization, design, construction, and experimental program was completed, which provided in-depth understanding of the dominant processes that are most likely to influence the containment of radionuclides for 10,000 years. Nearly 1,500 parameters were developed using information gathered from this program; the parameters were input to numerical models for WIPP Compliance Certification Application (CCA) Performance Assessment (PA) calculations. The CCA probabilistic codes frequently require input values that define a statistical distribution for each parameter. Developing parameter distributions begins with the assignment of an appropriate distribution type, which is dependent on the type, magnitude, and volume of data or information available. The development of the parameter distribution values may require interpretation or statistical analysis of raw data, combining raw data with literature values, scaling of lab or field data to fit code grid mesh sizes, or other transformation. Parameter development and documentation of the development process were very complicated, especially for those parameters based on empirical data; they required the integration of information from Sandia National Laboratories (SNL) code sponsors, parameter task leaders (PTLs), performance assessment analysts (PAAs), and experimental principal investigators (PIs). This paper, Part 1 of two parts, contains a discussion of the parameter development process, roles and responsibilities, and lessons learned. Part 2 will discuss parameter documentation, traceability and retrievability, and lessons learned from related audits and reviews

PA1 Protein, a New Competitive Decelerator Acting at More than One Step to Impede Glucocorticoid Receptor-mediated Transactivation*

Science.gov (United States)

Zhang, Zhenhuan; Sun, Yunguang; Cho, Young-Wook; Chow, Carson C.; Simons, S. Stoney

2013-01-01

Numerous cofactors modulate the gene regulatory activity of glucocorticoid receptors (GRs) by affecting one or more of the following three major transcriptional properties: the maximal activity of agonists (Amax), the potency of agonists (EC50), and the partial agonist activity of antisteroids (PAA). Here, we report that the recently described nuclear protein, Pax2 transactivation domain interaction protein (PTIP)-associated protein 1 (PA1), is a new inhibitor of GR transactivation. PA1 suppresses Amax, increases the EC50, and reduces the PAA of an exogenous reporter gene in a manner that is independent of associated PTIP. PA1 is fully active with, and strongly binds to, the C-terminal half of GR. PA1 reverses the effects of the coactivator TIF2 on GR-mediated gene induction but is unable to augment the actions of the corepressor SMRT. Analysis of competition assays between PA1 and TIF2 with an exogenous reporter indicates that the kinetic definition of PA1 action is a competitive decelerator at two sites upstream from where TIF2 acts. With the endogenous genes IGFBP1 and IP6K3, PA1 also represses GR induction, increases the EC50, and decreases the PAA. ChIP and re-ChIP experiments indicate that PA1 accomplishes this inhibition of the two genes via different mechanisms as follows: PA1 appears to increase GR dissociation from and reduce GR transactivation at the IGFBP1 promoter regions but blocks GR binding to the IP6K3 promoter. We conclude that PA1 is a new competitive decelerator of GR transactivation and can act at more than one molecularly defined step in a manner that depends upon the specific gene. PMID:23161582

PA1 protein, a new competitive decelerator acting at more than one step to impede glucocorticoid receptor-mediated transactivation.

Science.gov (United States)

Zhang, Zhenhuan; Sun, Yunguang; Cho, Young-Wook; Chow, Carson C; Simons, S Stoney

2013-01-04

Numerous cofactors modulate the gene regulatory activity of glucocorticoid receptors (GRs) by affecting one or more of the following three major transcriptional properties: the maximal activity of agonists (A(max)), the potency of agonists (EC(50)), and the partial agonist activity of antisteroids (PAA). Here, we report that the recently described nuclear protein, Pax2 transactivation domain interaction protein (PTIP)-associated protein 1 (PA1), is a new inhibitor of GR transactivation. PA1 suppresses A(max), increases the EC(50), and reduces the PAA of an exogenous reporter gene in a manner that is independent of associated PTIP. PA1 is fully active with, and strongly binds to, the C-terminal half of GR. PA1 reverses the effects of the coactivator TIF2 on GR-mediated gene induction but is unable to augment the actions of the corepressor SMRT. Analysis of competition assays between PA1 and TIF2 with an exogenous reporter indicates that the kinetic definition of PA1 action is a competitive decelerator at two sites upstream from where TIF2 acts. With the endogenous genes IGFBP1 and IP6K3, PA1 also represses GR induction, increases the EC(50), and decreases the PAA. ChIP and re-ChIP experiments indicate that PA1 accomplishes this inhibition of the two genes via different mechanisms as follows: PA1 appears to increase GR dissociation from and reduce GR transactivation at the IGFBP1 promoter regions but blocks GR binding to the IP6K3 promoter. We conclude that PA1 is a new competitive decelerator of GR transactivation and can act at more than one molecularly defined step in a manner that depends upon the specific gene.

Discharge source coupled to a deceleration unit for anion beam generation: Application to H{sub 2}{sup −} photodetachment

Energy Technology Data Exchange (ETDEWEB)

Rudnev, V.; Ureña, A. González [Unidad de Láseres y Haces Moleculares, Instituto Pluridisciplinar, Universidad Complutense, Juan XXIII-1, Madrid 28040 (Spain)

2013-12-15

A cathode discharge source coupled to a deceleration unit for anion beam generation is described. The discharge source, made of stainless steel or duralumin electrodes and Macor insulators, is attached to the exit nozzle valve plate at one end, and to an Einzel lens to the other end. Subsequently, a cylindrical retardation unit is attached to the Einzel lens to decelerate the ions in order to optimize the laser beam interaction time required for spectroscopic investigations. The compact device is able to produce beam intensities of the order of 2 × 10{sup 12} anions/cm{sup 2} s and 20 μrad of angular divergence with kinetic energies ranging from 30 to 120 eV. Using distinct gas mixtures for the supersonic expansion together with a linear time-of-flight spectrometer, anions of great relevance in molecular astrophysics like, for example, H{sub 2}{sup −}, C{sub 3}H{sup −}, C{sub 2}{sup −}, C{sub 2}H{sup −}, HCN{sub 2}{sup −}, CO{sub 2}{sup −}, CO{sub 2}H{sup −}, C{sub 4}{sup −}, C{sub 4}H{sup −}, C{sub 5}H{sub 4}{sup −}, C{sub 5}H{sub 6}{sup −}, C{sub 7}N{sup −}, and C{sub 10}N{sup −} were produced. Finally, in order to demonstrate the capability of the experimental technique the photodetachment cross-section of the metastable H{sub 2}{sup −}, predominantly in the (v = 0, J = 26) state, was measured following laser excitation at λ{sub exc}= 565 nm obtaining a value of σ{sub ph}= 0.04 Å. To the best of our knowledge, it is the first time that this anion cross-section has been measured.

Effects of Hypertonic Saline Solution on Clinical Parameters, Serum Electrolytes and Plasma Volume in the Treatment of Haemorrhagic Septicaemia in Buffaloes

Directory of Open Access Journals (Sweden)

M. Arif Zafar*, G. Muhammad, Zafar Iqbal1 and M. Riaz2

2010-04-01

Full Text Available This study was conducted to determine the efficacy of hypertonic saline solution (HSS along with antibiotic (ceftiofur HCl and non-steroidal anti-inflammatory drug (ketoprofen in the treatment of haemorrhagic septicaemia in buffaloes. For this purpose, 50 buffaloes suffering from haemorrhagic septicaemia were randomly divided in two equal groups A and B. Group A served as control and was treated with ceftiofur HCl (IM and ketoprofen (IV @ 6 and 2 mg/Kg BW, respectively, for five days. Buffaloes of group B were administered with rapid intravenous infusion of hypertonic saline solution (7.5% NaCl @ 4 ml/Kg BW once in combination with ceftiofur HCl and ketoprofen. Animals were monitored for 24 hours after initiation of treatment. Clinical parameters, serum electrolytes, plasma volume and survival index were recorded at different intervals after treatment. Survival rate (80% in group B was significantly higher (P<0.05 than 48% in group A. The heart rate and respiration rate recovered more effectively in the buffaloes administered with treatment protocol B. Plasma volume was 98% which was almost normal within 24 hours after the infusion of hypertonic saline solution to the animals of group B. It was concluded from the study that hypertonic saline solution as an adjunct to antibiotic and a non-steroidal anti-inflammatory drug more efficiently improved respiration and heart rates and effectively restored plasma volume in resuscitating the buffaloes from haemorrhagic septicaemia than the conventional treatment.

Relative blood volume monitoring during hemodialysis in end stage renal disease patients.

Science.gov (United States)

Ion Titapiccolo, Jasmine; Ferrario, Manuela; Garzotto, Francesco; Cruz, Dinna; Moissl, Ulrich; Tetta, Ciro; Ronco, Claudio; Signorini, Maria G; Cerutti, Sergio

2010-01-01

A crucial point in the haemodialysis (HD) treatment is the reliable assessment of hydration status. An inadequate removed volume may lead to chronic fluid overload which can lead to hypertension, left ventricular hypertrophy and heart failure. Therefore, the estimation of the hydration state and the management of a well-tolerated water removal is an important challenge. This exploratory study aims at identifying new parameters obtained from continuous Blood Volume Monitoring (BVM) allowing a qualitative evaluation of hydration status for verifying the adequacy of HD setting parameters (e.g UFR, target dry weight). The percentage of blood volume reduction (BVR%) during HD was compared against a gold standard method for hydration status assessment. The slope of the first 30 minute of blood volume reduction (BVR) was proposed as a useful parameter to identify overhydrated patients.

Risk Factors for Neovascular Glaucoma After Proton Beam Therapy of Uveal Melanoma: A Detailed Analysis of Tumor and Dose–Volume Parameters

Energy Technology Data Exchange (ETDEWEB)

Mishra, Kavita K., E-mail: kmishra@radonc.ucsf.edu [Department of Radiation Oncology, University of California, San Francisco, San Francisco, California (United States); Daftari, Inder K.; Weinberg, Vivian [Department of Radiation Oncology, University of California, San Francisco, San Francisco, California (United States); Cole, Tia [The Tumori Foundation, San Francisco, California (United States); Quivey, Jeanne M.; Castro, Joseph R.; Phillips, Theodore L. [Department of Radiation Oncology, University of California, San Francisco, San Francisco, California (United States); Char, Devron H. [The Tumori Foundation, San Francisco, California (United States)

2013-10-01

Purpose: To determine neovascular glaucoma (NVG) incidence and identify contributing tumor and dosing factors in uveal melanoma patients treated with proton beam radiation therapy (PBRT). Methods and Materials: A total of 704 PBRT patients treated by a single surgeon (DHC) for uveal melanoma (1996-2010) were reviewed for NVG in our prospectively maintained database. All patients received 56 GyE in 4 fractions. Median follow-up was 58.3 months. Analyses included the Kaplan-Meier method to estimate NVG distributions, univariate log–rank tests, and Cox's proportional hazards multivariate analysis using likelihood ratio tests to identify independent risk factors of NVG among patient, tumor, and dose–volume histogram parameters. Results: The 5-year PBRT NVG rate was 12.7% (95% confidence interval [CI] 10.2%-15.9%). The 5-year rate of enucleation due to NVG was 4.9% (95% CI 3.4%-7.2%). Univariately, the NVG rate increased significantly with larger tumor diameter (P<.0001), greater height (P<.0001), higher T stage (P<.0001), and closer proximity to the disc (P=.002). Dose–volume histogram analysis revealed that if >30% of the lens or ciliary body received ≥50% dose (≥28 GyE), there was a higher probability of NVG (P<.0001 for both). Furthermore, if 100% of the disc or macula received ≥28 GyE, the NVG rate was higher (P<.0001 and P=.03, respectively). If both anterior and posterior doses were above specified cut points, NVG risk was highest (P<.0001). Multivariate analysis confirmed significant independent risk factors to include tumor height (P<.0001), age (P<.0001), %disc treated to ≥50% Dose (<100% vs 100%) (P=.0007), larger tumor diameter (P=.01), %lens treated to ≥90% Dose (0 vs >0%-30% vs >30%) (P=.01), and optic nerve length treated to ≥90% Dose (≤1 mm vs >1 mm) (P=.02). Conclusions: Our current PBRT patients experience a low rate of NVG and resultant enucleation compared with historical data. The present analysis shows that tumor height

Solar wind deceleration and MHD turbulence in the earth's foreshock region: ISEE 1 and 2 and IMP 8 observations

International Nuclear Information System (INIS)

Bonifazi, C.; Moreno, G.; Russell, C.T.; Lazarus, A.J.; Sullivan, J.D.

1983-01-01

The interaction of the solar wind with ions backstreaming from the earth's bow shock is investigated using plasma and magnetic field measurements on ISEE 1 and 2 and IMP 8 at widely separated positions in the earth's foreshock. This technique separates temporal and spatial variations within the foreshock. It is found that the solar wind acceleration associated with backstreaming ions is correlated with the amplitude of the MHD turbulence and that the largest decelerations are seen close to the bow shock. The density of the backstreaming ion beam is stronly correlated with distance from the shock and decreases by about a factor of 3 in a distance of about 3 R/sub E/

Solar wind deceleration and MHD turbulence in the earth's foreshock region - ISEE 1 and 2 and IMP 8 observations

Science.gov (United States)

Bonifazi, C.; Moreno, G.; Russell, C. T.; Lazarus, A. J.; Sullivan, J. D.

1983-01-01

The interaction of the solar wind with ions backstreaming from the earth's bow shock is investigated using plasma and magnetic field measurements on ISEE 1 and 2 and IMP 8 at widely separated positions in the earth's foreshock. This technique separates temporal and spatial variations within the foreshock. It is found that the solar wind acceleration associated with backstreaming ions is correlated with the amplitude of the MHD turbulence, and that the largest decelerations are seen close to the bow shock. The density of the backstreaming ion beam is strongly correlated with distance from the shock, and decreases by about a factor of three in a distance of about 3R(e).

The dependence of prostate postimplant dosimetric quality on CT volume determination

International Nuclear Information System (INIS)

Merrick, Gregory S.; Butler, Wayne M.; Dorsey, Anthony T.; Lief, Jonathan H.

1999-01-01

Purpose: The postoperative evaluation of permanent prostate brachytherapy requires a subjective determination of the implant volume. This work investigates the magnitude of the effect that various methods of treatment volume delineation have on dosimetric quality parameters for a treatment planning philosophy that defines a target volume as the prostate with a periprostatic margin. Methods and Materials: Eight consecutive prostate brachytherapy patients with a prescribed dose of 145 Gy from 125 I as monotherapy comprised the study population. The prostate ultrasound volume was enlarged to a planning volume by an average factor of 1.8 to encompass probable extracapsular extension in the periprostatic region. For this cohort, the mean pretreatment parameters were 30.3 cm 3 ultrasound volume, 51.8 cm 3 planning volume, 131 seeds per patient, and 42.9 mCi total activity. On CT study sets obtained less than 2 hours postoperatively, target volumes were drawn using three methods: prostate plus a periprostatic margin, prostate only which excluded the puborectalis muscles, the periprostatic fat and the periprostatic venous plexus, and the preplanning ultrasound magnified to conform to the magnification factor of the postimplant CT scan. Three sets of 5 dosimetric quality parameters corresponding to the different volumetric approaches were calculated: V100, V150, and V200 which are the fractions of the target volume covered by 100, 150, and 200% of the prescribed dose, and D90 and D100, which are the minimal doses covering 90 and 100% of the target volume. Results: The postoperative CT volume utilizing the prostate plus margin technique was comparable to the initial planning volume (mean 55.5 cm 3 vs. 51.8 cm 3 , respectively) whereas those determined via superimposing the preplan ultrasound resulted in volumes nearly identical to the initial ultrasound evaluation (mean 32.4 cm 3 vs. 30.3 cm 3 ). The prostate only approach resulted in volumes approximately 25% larger than

Left ventricular diastolic function is associated with symptom status in severe aortic valve stenosis

DEFF Research Database (Denmark)

Dahl, Jordi S; Christensen, Nicolaj L; Videbæk, Lars

2014-01-01

atrial volume index, and deceleration time were still associated with the presence of symptoms. CONCLUSIONS: The present study demonstrates that symptomatic status in severe AS is associated with impaired diastolic function, LV hypertrophy, concentric remodeling, and left atrial dilatation when corrected...... function, and left atrial dilatation compared with asymptomatic patients. METHODS AND RESULTS: In a retrospective descriptive study, we compared clinical characteristics and echocardiographic parameters in 99 symptomatic and 139 asymptomatic patients with severe AS and LV ejection fraction ≥50.......001), and had a lower prevalence of hypertension (73% versus 40%; Ptime (199±58 versus...

Relationship between thermodynamic parameter and thermodynamic scaling parameter for orientational relaxation time for flip-flop motion of nematic liquid crystals.

Science.gov (United States)

Satoh, Katsuhiko

2013-03-07

Thermodynamic parameter Γ and thermodynamic scaling parameter γ for low-frequency relaxation time, which characterize flip-flop motion in a nematic phase, were verified by molecular dynamics simulation with a simple potential based on the Maier-Saupe theory. The parameter Γ, which is the slope of the logarithm for temperature and volume, was evaluated under various conditions at a wide range of temperatures, pressures, and volumes. To simulate thermodynamic scaling so that experimental data at isobaric, isothermal, and isochoric conditions can be rescaled onto a master curve with the parameters for some liquid crystal (LC) compounds, the relaxation time was evaluated from the first-rank orientational correlation function in the simulations, and thermodynamic scaling was verified with the simple potential representing small clusters. A possibility of an equivalence relationship between Γ and γ determined from the relaxation time in the simulation was assessed with available data from the experiments and simulations. In addition, an argument was proposed for the discrepancy between Γ and γ for some LCs in experiments: the discrepancy arises from disagreement of the value of the order parameter P2 rather than the constancy of relaxation time τ1(*) on pressure.

Age-specific changes in left ventricular diastolic function: A velocity-encoded magnetic resonance imaging study

Energy Technology Data Exchange (ETDEWEB)

Ashrafpoor, Golmehr [Sorbonne Universites, UPMC Univ Paris 06, UMR 7371, UMR S 1146, Laboratoire d' Imagerie Biomedicale, Paris (France); INSERM, UMR S 1146, Laboratoire d' Imagerie Biomedicale, Paris (France); CNRS, UMR 7371, Laboratoire d' Imagerie Biomedicale, Paris (France); Universite Paris Descartes, Cardiovascular Imaging Department, European Hospital Georges Pompidou, Paris (France); Bollache, Emilie; Cesare, Alain de; Giron, Alain; Defrance, Carine; Kachenoura, Nadjia [Sorbonne Universites, UPMC Univ Paris 06, UMR 7371, UMR S 1146, Laboratoire d' Imagerie Biomedicale, Paris (France); INSERM, UMR S 1146, Laboratoire d' Imagerie Biomedicale, Paris (France); CNRS, UMR 7371, Laboratoire d' Imagerie Biomedicale, Paris (France); Redheuil, Alban [Sorbonne Universites, UPMC Univ Paris 06, UMR 7371, UMR S 1146, Laboratoire d' Imagerie Biomedicale, Paris (France); INSERM, UMR S 1146, Laboratoire d' Imagerie Biomedicale, Paris (France); CNRS, UMR 7371, Laboratoire d' Imagerie Biomedicale, Paris (France); Hopital Pitie-Salpetriere, Department of Cardiovascular Radiology, Institut de Cardiologie, Paris (France); ICAN, Imaging Core Lab, Paris (France); Azarine, Arshid [INSERM, UMR S 1146, Laboratoire d' Imagerie Biomedicale, Paris (France); Universite Paris Descartes, Cardiovascular Imaging Department, European Hospital Georges Pompidou, Paris (France); Perdrix, Ludivine; Ladouceur, Magalie [European Hospital Georges Pompidou, Cardiology Department, Paris (France); Diebold, Benoit [Sorbonne Universites, UPMC Univ Paris 06, UMR 7371, UMR S 1146, Laboratoire d' Imagerie Biomedicale, Paris (France); INSERM, UMR S 1146, Laboratoire d' Imagerie Biomedicale, Paris (France); CNRS, UMR 7371, Laboratoire d' Imagerie Biomedicale, Paris (France); European Hospital Georges Pompidou, Cardiology Department, Paris (France); Mousseaux, Elie [Sorbonne Universites, UPMC Univ Paris 06, UMR 7371, UMR S 1146, Laboratoire d' Imagerie Biomedicale, Paris (France); INSERM, UMR S 1146, Laboratoire d' Imagerie Biomedicale, Paris (France); CNRS, UMR 7371, Laboratoire d' Imagerie Biomedicale, Paris (France); Universite Paris Descartes, Cardiovascular Imaging Department, European Hospital Georges Pompidou, Paris (France); European Hospital Georges Pompidou, Cardiology Department, Paris (France)

2015-04-01

Our objectives were to assess the ability of phasecontrast MRI (PC-MRI) to detect sub-clinical age-related variations of left ventricular (LV) diastolic parameters and thus to provide age-related reference ranges currently available for echocardiography but not for MRI-PC, and to identify independent associates of such variations. We studied 100 healthy volunteers (age = 42 ± 15years, 50 females) who had MRI with simultaneous blood pressure measurements. LV mass and volumes were assessed. Semiautomated analysis of PC-MRI data provided: 1) early transmitral (Ef) and atrial (Af) peak filling flow-rates (ml/s) and filling volume (FV), 2) deceleration time (DT), isovolumic relaxation time (IVRT), and 3) early myocardial longitudinal (E') peak velocity. MRI-PC diastolic parameters were reproducible as reflected by low coefficients of variations (ranged between 0.31 to 6.26 %). Peak myocardial velocity E' (r = -0.63, p < 0.0001) and flow-rate parameters were strongly and independently associated to age (Ef/Af:r = -0.63, DT:r = 0.46, IVRT:r = 0.44, Ef/FV:r = -0.55, Af/FV:r = 0.56, p < 0.0001). Furthermore, LV relaxation parameters (E', DT, IVRT), were independently associated to LV remodelling (LV mass/end-diastolic volume) and myocardial wall thickness (p < 0.01). PC-MRI age-related reference ranges of diastolic parameters are provided. Such parameters might be useful for a fast, reproducible and reliable characterization of diastolic function in patients referred for clinical MRI exam. (orig.)

The influence of various pressures in pneumatic tyre on braking process of car with anti-lock braking system

OpenAIRE

Damian HADRYŚ; Tomasz WĘGRZYN; Michał MIROS

2008-01-01

In this article has been presented the influence of various pressures inpneumatic tyre of passenger car Fiat Panda 1.3 JTD with anti-lock braking system on chosen parameters of braking process: course of braking deceleration, maximum value of deceleration, braking distances.

Clinically significant change in stroke volume in pulmonary hypertension

NARCIS (Netherlands)

van Wolferen, S.A.; van de Veerdonk, M.C.; Mauritz, G.J.; Jacobs, W.; Marcus, J.T.; Marques, K.M.J.; Bronzwaer, J.G.F.; Heijmans, M.W.; Boonstra, A.; Postmus, P.E.; Westerhof, N.; Noordegraaf, A.V.

2011-01-01

Background: Stroke volume is probably the best hemodynamic parameter because it reflects therapeutic changes and contains prognostic information in pulmonary hypertension (PH). Stroke volume directly reflects right ventricular function in response to its load, without the correction of compensatory

Establishment of database for Japan Sea parameters on marine environment and radioactivity (JASPER). Volume 2. Radiocarbon and oceanographic properties

International Nuclear Information System (INIS)

Otosaka, Shigeyoshi; Suzuki, Takashi; Ito, Toshimichi; Kobayashi, Takuya; Kawamura, Hideyuki; Togawa, Orihiko; Tanaka, Takayuki; Minakawa, Masayuki; Aramaki, Takafumi; Senjyu, Tomoharu

2010-02-01

The database for the Japan Sea Parameters on Marine Environment and Radionuclides (JASPER) has been established by the Japan Atomic Energy Agency as a product of the Japan Sea Expeditions. By the previous volume of the database, data for representative anthropogenic radionuclides (strontium-90, cesium-137, and plutonium-239, 240) were opened to public. And now, data for radiocarbon and fundamental oceanographic properties (salinity, temperature, dissolved oxygen) including nutrients (silicate, phosphate, nitrate and nitrite) are released as the second volume of the database. At the beginning of this report (chapter 1), backgrounds, objectives and brief overview of this report are given as an introduction. Then, specifications of this database and methodology in obtaining the concentration data are described in chapter 2. The data stored in the database are presented in tabular and figure forms in chapter 3. Finally, chapter 4 is assigned concluding remarks. In the second version of database, 20,292 data records are stored in the database including 2,695 data for temperature, 2,883 data for salinity, 2,109 data for dissolved oxygen, 11,051 data for the nutrients, and 1,660 data for radiocarbon. The database will be a strong tool for the continuous monitoring for contamination by anthropogenic radionuclides, studies on biogeochemical cycle, and development/validation of models for numerical simulations in the sea. (author)

Parameter estimation in stochastic differential equations

CERN Document Server

Bishwal, Jaya P N

2008-01-01

Parameter estimation in stochastic differential equations and stochastic partial differential equations is the science, art and technology of modelling complex phenomena and making beautiful decisions. The subject has attracted researchers from several areas of mathematics and other related fields like economics and finance. This volume presents the estimation of the unknown parameters in the corresponding continuous models based on continuous and discrete observations and examines extensively maximum likelihood, minimum contrast and Bayesian methods. Useful because of the current availability of high frequency data is the study of refined asymptotic properties of several estimators when the observation time length is large and the observation time interval is small. Also space time white noise driven models, useful for spatial data, and more sophisticated non-Markovian and non-semimartingale models like fractional diffusions that model the long memory phenomena are examined in this volume.

Kinematic parameters of signed verbs.

Science.gov (United States)

Malaia, Evie; Wilbur, Ronnie B; Milkovic, Marina

2013-10-01

Sign language users recruit physical properties of visual motion to convey linguistic information. Research on American Sign Language (ASL) indicates that signers systematically use kinematic features (e.g., velocity, deceleration) of dominant hand motion for distinguishing specific semantic properties of verb classes in production ( Malaia & Wilbur, 2012a) and process these distinctions as part of the phonological structure of these verb classes in comprehension ( Malaia, Ranaweera, Wilbur, & Talavage, 2012). These studies are driven by the event visibility hypothesis by Wilbur (2003), who proposed that such use of kinematic features should be universal to sign language (SL) by the grammaticalization of physics and geometry for linguistic purposes. In a prior motion capture study, Malaia and Wilbur (2012a) lent support for the event visibility hypothesis in ASL, but there has not been quantitative data from other SLs to test the generalization to other languages. The authors investigated the kinematic parameters of predicates in Croatian Sign Language ( Hrvatskom Znakovnom Jeziku [HZJ]). Kinematic features of verb signs were affected both by event structure of the predicate (semantics) and phrase position within the sentence (prosody). The data demonstrate that kinematic features of motion in HZJ verb signs are recruited to convey morphological and prosodic information. This is the first crosslinguistic motion capture confirmation that specific kinematic properties of articulator motion are grammaticalized in other SLs to express linguistic features.

Reliability of tanoak volume equations when applied to different areas

Science.gov (United States)

Norman H. Pillsbury; Philip M. McDonald; Victor Simon

1995-01-01

Tree volume equations for tanoak (Lithocarpus densiflorus) were developed for seven stands throughout its natural range and compared by a volume prediction and a parameter difference method. The objective was to test if volume estimates from a species growing in a local, relatively uniform habitat could be applied more widely. Results indicated...

The influence of various pressures in pneumatic tyre on braking process of car with anti-lock braking system

Directory of Open Access Journals (Sweden)

Damian HADRYŚ

2008-01-01

Full Text Available In this article has been presented the influence of various pressures inpneumatic tyre of passenger car Fiat Panda 1.3 JTD with anti-lock braking system on chosen parameters of braking process: course of braking deceleration, maximum value of deceleration, braking distances.

Clinically significant change in stroke volume in pulmonary hypertension.

Science.gov (United States)

van Wolferen, Serge A; van de Veerdonk, Marielle C; Mauritz, Gert-Jan; Jacobs, Wouter; Marcus, J Tim; Marques, Koen M J; Bronzwaer, Jean G F; Heymans, Martijn W; Boonstra, Anco; Postmus, Pieter E; Westerhof, Nico; Vonk Noordegraaf, Anton

2011-05-01

Stroke volume is probably the best hemodynamic parameter because it reflects therapeutic changes and contains prognostic information in pulmonary hypertension (PH). Stroke volume directly reflects right ventricular function in response to its load, without the correction of compensatory increased heart rate as is the case for cardiac output. For this reason, stroke volume, which can be measured noninvasively, is an important hemodynamic parameter to monitor during treatment. However, the extent of change in stroke volume that constitutes a clinically significant change is unknown. The aim of this study was to determine the minimal important difference (MID) in stroke volume in PH. One hundred eleven patients were evaluated at baseline and after 1 year of follow-up with a 6-min walk test (6MWT) and cardiac MRI. Using the anchor-based method with 6MWT as the anchor, and the distribution-based method, the MID of stroke volume change could be determined. After 1 year of treatment, there was, on average, a significant increase in stroke volume and 6MWT. The change in stroke volume was related to the change in 6MWT. Using the anchor-based method, an MID of 10 mL in stroke volume was calculated. The distribution-based method resulted in an MID of 8 to 12 mL. Both methods showed that a 10-mL change in stroke volume during follow-up should be considered as clinically relevant. This value can be used to interpret changes in stroke volume during clinical follow-up in PH.

Relation between injected volume and optical parameters in refilled isolated porcine lenses

NARCIS (Netherlands)

Koopmans, SA; Terwee, T; Haitjema, HJ; Deuring, H; van Aarle, S; Kooijman, AC

2004-01-01

Purpose: This study was performed to elucidate the correlation between added lens refill material and enhanced lens power as well as the correlation between lens refilling volume and accommodative amplitude as determined by equatorial stretching of ex vivo refilled pigs' lenses. Methods: Nine

A parallel coordinates style interface for exploratory volume visualization.

Science.gov (United States)

Tory, Melanie; Potts, Simeon; Möller, Torsten

2005-01-01

We present a user interface, based on parallel coordinates, that facilitates exploration of volume data. By explicitly representing the visualization parameter space, the interface provides an overview of rendering options and enables users to easily explore different parameters. Rendered images are stored in an integrated history bar that facilitates backtracking to previous visualization options. Initial usability testing showed clear agreement between users and experts of various backgrounds (usability, graphic design, volume visualization, and medical physics) that the proposed user interface is a valuable data exploration tool.

SU-F-T-378: Evaluation of Dose-Volume Variability and Parameters Between Prostate IMRT and VMAT Plans

Energy Technology Data Exchange (ETDEWEB)

Chow, J [Princess Margaret Cancer Centre, Toronto, ON (Canada); Jiang, R [Grand River Regional Cancer Centre, Kitchener, ON (Canada); Kiciak, A [University of Waterloo, Waterloo, ON (Canada)

2016-06-15

Purpose: This study compared the rectal dose-volume consistency, equivalent uniform dose (EUD) and normal tissue complication probability (NTCP) in prostate intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT). Methods: For forty prostate IMRT and fifty VMAT patients treated using the same dose prescription (78 Gy/39 fraction) and dose-volume criteria in inverse planning optimization, the rectal EUD and NTCP were calculated for each patient. The rectal dose-volume consistency, showing the variability of dose-volume histogram (DVH) among patients, was defined and calculated based on the deviation between the mean and corresponding rectal DVH. Results: From both the prostate IMRT and VMAT plans, the rectal EUD and NTCP were found decreasing with the rectal volume. The decrease rates for the IMRT plans (EUD = 0.47 × 10{sup −3} Gy cm{sup −3} and NTCP = 3.94 × 10{sup −2} % cm{sup −3}) were higher than those for the VMAT (EUD = 0.28 × 10{sup −3} Gy cm{sup −3} and NTCP = 2.61 × 10{sup −2} % cm{sup −3}). In addition, the dependences of the rectal EUD and NTCP on the dose-volume consistency were found very similar between the prostate IMRT and VMAT plans. This shows that both delivery techniques have similar variations of the rectal EUD and NTCP on the dose-volume consistency. Conclusion: Dependences of the dose-volume consistency on the rectal EUD and NTCP were compared between the prostate IMRT and VMAT plans. It is concluded that both rectal EUD and NTCP decreased with an increase of the rectal volume. The variation rates of the rectal EUD and NTCP on the rectal volume were higher for the IMRT plans than VMAT. However, variations of the rectal dose-volume consistency on the rectal EUD and NTCP were found not significant for both delivery techniques.

Models for estimation of tree volume in the miombo woodlands of ...

African Journals Online (AJOL)

Volume of trees is an important parameter in forest management, but only volume models with limited geographical and tree size coverage have previously been developed for Tanzanian miombo woodlands. This study developed models for estimating total, merchantable stem and branches volume applicable for the entire ...

Bronchodilator response of advanced lung function parameters depending on COPD severity

Directory of Open Access Journals (Sweden)

Jarenbäck L

2016-11-01

Full Text Available Linnea Jarenbäck,1 Göran Eriksson,1 Stefan Peterson,2 Jaro Ankerst,1 Leif Bjermer,1 Ellen Tufvesson1 1Respiratory Medicine and Allergology, Department of Clinical Sciences Lund, Lund University, 2Regional Cancer Center South, Skåne University Hospital, Lund, Sweden Background: COPD is defined as partly irreversible airflow obstruction. The response pattern of bronchodilators has not been followed in advanced lung function parameters. Purpose: The aim of this study was to investigate bronchodilator response pattern in advanced lung function parameters in a continuous fashion along forced expiratory volume in 1 second (FEV1 percent predicted (%p in COPD patients and controls. Patients and methods: Eighty-one smokers/ex-smokers (41 controls and 40 COPD performed spirometry, body plethysmography, impulse oscillometry and single-breath helium dilution carbon monoxide diffusion at baseline, after salbutamol inhalation and then after an additional inhalation of ipratropium. Results: Most pulmonary function parameters showed a linear increase in response to decreased FEV1%p. The subjects were divided into groups of FEV1%p <65 and >65, and the findings from continuous analysis were verified. The exceptions to this linear response were inspiratory capacity (IC, forced vital capacity (FVC, FEV1/FVC and expiratory resistance (Rex, which showed a segmented response relationship to FEV1%p. IC and FVC, with break points (BP of 57 and 58 FEV1%p respectively, showed no response above, but an incresed slope below the BP. In addition, in patients with FEV1%p <65 and >65, response of FEV1%p did not correlate to response of volume parameters. Conclusion: Response of several advanced lung function parameters differs depending on patients’ baseline FEV1%p, and specifically response of volume parameters is most pronounced in COPD patients with FEV1%p <65. Volume and resistance responses do not follow the flow response measured with FEV1 and may thus be used as a

VISUALIZATION OF BIOLOGICAL TISSUE IMPEDANCE PARAMETERS

Directory of Open Access Journals (Sweden)

V. I. Bankov

2016-01-01

Full Text Available Objective. Investigation the opportunity for measurement of biological tissue impedance to visualize its parameters.Materials and methods. Studies were undertook on the experimental facility, consists of registrating measuring cell, constructed from flat inductors system, formed in oscillatory circuit, herewith investigated biological tissue is the part of this oscillatory circuit. An excitation of oscillatory circuit fulfilled by means of exciter inductor which forms impulse complex modulated electromagnetic field (ICM EMF. The measurement process and visualizations provided by set of certificated instruments: a digital oscillograph AKTAKOM ADS-2221MV, a digital generator АКТАКОМ AWG-4150 (both with software and a gauge RLC E7-22. Comparative dynamic studies of fixed volume and weight pig’s blood, adipose tissue, muscular tissue impedance were conducted by contact versus contactless methods. Contactless method in contrast to contact method gives opportunity to obtain the real morphological visualization of biological tissue irrespective of their nature.Results. Comparison of contact and contactless methods of impedance measurement shows that the inductance to capacitance ratio X(L / X(C was equal: 17 – for muscular tissue, 4 – for blood, 1 – for adipose tissue. It demonstrates the technical correspondence of both impedance registration methods. If propose the base relevance of X (L and X (C parameters for biological tissue impedance so contactless measurement method for sure shows insulating properties of adipose tissue and high conductivity for blood and muscular tissue in fixed volume-weight parameters. Registration of biological tissue impedance complex parameters by contactless method with the help of induced ICM EMF in fixed volume of biological tissue uncovers the most important informative volumes to characterize morphofunctional condition of biological tissue namely X (L / X (C.Conclusion. Contactless method of biological

Calculations enable optimum design of magnetic brake

Science.gov (United States)

Kosmahl, H. G.

1966-01-01

Mathematical analysis and computations determine optimum magnetic coil configurations for a magnetic brake which controllably decelerates a free falling load to a soft stop. Calculations on unconventionally wound coils determine the required parameters for the desired deceleration with minimum electrical energy supplied to the stationary coil.

Biotropic parameters of magnetic fields

Energy Technology Data Exchange (ETDEWEB)

Shishlo, M.A.

The use of magnetic fields (MF) in biology and medicine to control biological systems has led to appearance of the term, biotropic parameters of MF. They include the physical characteristics of MF, which determine the primary biologically significant physicochemical mechanisms of field action causing formation of corresponding reactions on the level of the integral organism. These parameters include MF intensity, gradient, vector, pulse frequency and shape, and duration of exposure. Factors that elicit responses by the biological system include such parameter of MF interaction with the integral organism as localization of exposure and volume of tissues interacting with the field, as well as the initial state of the organism. In essence, the findings of experimental studies of biotropic parameters of MF make it possible to control physiological processes and will aid in optimizing methods of MF therapy.

Investigating parameters participating in the infant respiratory control system attractor.

Science.gov (United States)

Terrill, Philip I; Wilson, Stephen J; Suresh, Sadasivam; Cooper, David M; Dakin, Carolyn

2008-01-01

Theoretically, any participating parameter in a non-linear system represents the dynamics of the whole system. Taken's time delay embedding theory provides the fundamental basis for allowing non-linear analysis to be performed on physiological, time-series data. In practice, only one measurable parameter is required to be measured to convey an accurate representation of the system dynamics. In this paper, the infant respiratory control system is represented using three variables-a digitally sampled respiratory inductive plethysmography waveform, and the derived parameters tidal volume and inter-breath interval time series data. For 14 healthy infants, these data streams were analysed using recurrence plot analysis across one night of sleep. The measured attractor size of these variables followed the same qualitative trends across the nights study. Results suggest that the attractor size measures of the derived IBI and tidal volume are representative surrogates for the raw respiratory waveform. The extent to which the relative attractor sizes of IBI and tidal volume remain constant through changing sleep state could potentially be used to quantify pathology, or maturation of breathing control.

Preferential effects of low volume versus high volume replacement with crystalloid fluid in a hemorrhagic shock model in pigs.

Science.gov (United States)

Ponschab, Martin; Schöchl, Herbert; Keibl, Claudia; Fischer, Henrik; Redl, Heinz; Schlimp, Christoph J

2015-10-06

Fluid resuscitation is a core stone of hemorrhagic shock therapy, and crystalloid fluids seem to be associated with lower mortality compared to colloids. However, as redistribution starts within minutes, it has been suggested to replace blood loss with a minimum of a three-fold amount of crystalloids. The hypothesis was that in comparison to high volume (HV), a lower crystalloid volume (LV) achieves a favorable coagulation profile and exerts sufficient haemodynamics in the acute phase of resuscitation. In 24 anaesthetized pigs, controlled arterial blood loss of 50 % of the estimated blood volume was either (n = 12) replaced with a LV (one-fold) or a HV (three-fold) volume of a balanced, acetated crystalloid solution at room temperature. Hemodynamic parameters, dilution effects and coagulation profile by standard coagulation tests and thromboelastometry at baseline and after resuscitation were determined in both groups. LV resuscitation increased MAP significantly less compared to the HV, 61 ± 7 vs. 82 ± 14 mmHg (p controlled blood loss, a one fold LV crystalloid replacement strategy is sufficient to adequately raise blood pressure up to a mean arterial pressure >50 mm Hg. The concept of damage control resuscitation (DCR) with permissive hypotension may be better met by using LV as compared to a three fold HV resuscitation strategy. High volume administration of an acetated balanced crystalloid does not lead to hyperchloraemic acidosis, but may negatively influence clinical parameters, such as higher blood pressure, lower body temperature and impaired coagulation parameters, which could potentially increase bleeding after trauma. Replacement of acute blood loss with just an equal amount of an acetated balanced crystalloid appears to be the preferential treatment strategy in the acute phase after controlled bleeding.

Convex hull approach for determining rock representative elementary volume for multiple petrophysical parameters using pore-scale imaging and Lattice-Boltzmann modelling

Science.gov (United States)

Shah, S. M.; Crawshaw, J. P.; Gray, F.; Yang, J.; Boek, E. S.

2017-06-01

In the last decade, the study of fluid flow in porous media has developed considerably due to the combination of X-ray Micro Computed Tomography (micro-CT) and advances in computational methods for solving complex fluid flow equations directly or indirectly on reconstructed three-dimensional pore space images. In this study, we calculate porosity and single phase permeability using micro-CT imaging and Lattice Boltzmann (LB) simulations for 8 different porous media: beadpacks (with bead sizes 50 μm and 350 μm), sandpacks (LV60 and HST95), sandstones (Berea, Clashach and Doddington) and a carbonate (Ketton). Combining the observed porosity and calculated single phase permeability, we shed new light on the existence and size of the Representative Element of Volume (REV) capturing the different scales of heterogeneity from the pore-scale imaging. Our study applies the concept of the 'Convex Hull' to calculate the REV by considering the two main macroscopic petrophysical parameters, porosity and single phase permeability, simultaneously. The shape of the hull can be used to identify strong correlation between the parameters or greatly differing convergence rates. To further enhance computational efficiency we note that the area of the convex hull (for well-chosen parameters such as the log of the permeability and the porosity) decays exponentially with sub-sample size so that only a few small simulations are needed to determine the system size needed to calculate the parameters to high accuracy (small convex hull area). Finally we propose using a characteristic length such as the pore size to choose an efficient absolute voxel size for the numerical rock.

Biological modelling of fuzzy target volumes in 3D radiotherapy

International Nuclear Information System (INIS)

Levegruen, S.; Kampen, M. van; Waschek, T.; Engenhart, R.; Schlegel, W.

1995-01-01

Purpose/Objective: The outcome of each radiotherapy depends critically on the optimal choice of the target volume. The goal of the radiotherapist is to include all tumor spread at the same time as saving as much healthy tissue as possible. Even when the information of all imaging modalities is combined, the diagnostic techniques are not sensitive and specific enough to visualize all microscopic tumor cell spread. Due to this lack of information there is room for different interpretations concerning the extend of the target volume, leading to a fuzzy target volume. The aim of this work is to develop a model to score different target volume boundaries within the region of diagnostic uncertainty in terms of tumor control probability (TCP) and normal tissue complication probabilities (NTCP). Materials and Methods: In order to assess the region of diagnostic uncertainty, the radiotherapist defines interactively a minimal planning target volume that absolutely must be irradiated according to the diagnostic information available and a maximal planning target volume outside which no tumor cell spread is expected. For the NTCP calculation we use the Lyman 4 parameter model to estimate the response of an organ at risk to a uniform partial volume irradiation. The TCP calculation is based on the Poisson model of cell killing. The TCP estimation depends not only on volume, dose, clonogenic cell density and the α parameter of the linear quadratic model but also on the probability to find clonogenic cells in the considered volume. Inside the minimal PTV this probability is 1, outside the maximal PTV it is 0. Therefore all voxels inside the minimal PTV are assigned the value of 1 with respect to the target volume, all voxels outside the maximal PTV the value of 0. For voxels in the region of uncertainty in between, a 3D linear interpolation is performed. Here we assume the probability to follow the interpolated values. Starting with the minimal PTV, the expected gain in TCP and

Volumes and doses for external radiotherapy - Definitions and recommendations; Volum og doser i ekstern straaleterapi - Definisjoner og anbefalinger

Energy Technology Data Exchange (ETDEWEB)

Levernes, Sverre (ed.)

2012-07-01

The report contains definitions of volume and dose parameters for external radiotherapy. In addition the report contains recommendations for use, documentation and minimum reporting for radiotherapy of the individual patient.(Author)

Predicting uncertainty in future marine ice sheet volume using Bayesian statistical methods

Science.gov (United States)

Davis, A. D.

2015-12-01

The marine ice instability can trigger rapid retreat of marine ice streams. Recent observations suggest that marine ice systems in West Antarctica have begun retreating. However, unknown ice dynamics, computationally intensive mathematical models, and uncertain parameters in these models make predicting retreat rate and ice volume difficult. In this work, we fuse current observational data with ice stream/shelf models to develop probabilistic predictions of future grounded ice sheet volume. Given observational data (e.g., thickness, surface elevation, and velocity) and a forward model that relates uncertain parameters (e.g., basal friction and basal topography) to these observations, we use a Bayesian framework to define a posterior distribution over the parameters. A stochastic predictive model then propagates uncertainties in these parameters to uncertainty in a particular quantity of interest (QoI)---here, the volume of grounded ice at a specified future time. While the Bayesian approach can in principle characterize the posterior predictive distribution of the QoI, the computational cost of both the forward and predictive models makes this effort prohibitively expensive. To tackle this challenge, we introduce a new Markov chain Monte Carlo method that constructs convergent approximations of the QoI target density in an online fashion, yielding accurate characterizations of future ice sheet volume at significantly reduced computational cost.Our second goal is to attribute uncertainty in these Bayesian predictions to uncertainties in particular parameters. Doing so can help target data collection, for the purpose of constraining the parameters that contribute most strongly to uncertainty in the future volume of grounded ice. For instance, smaller uncertainties in parameters to which the QoI is highly sensitive may account for more variability in the prediction than larger uncertainties in parameters to which the QoI is less sensitive. We use global sensitivity

Maternal deprivation decelerates postnatal morphological lung development of F344 rats.

Science.gov (United States)

Hupa, Katharina Luise; Schmiedl, Andreas; Pabst, Reinhard; Von Hörsten, Stephan; Stephan, Michael

2014-02-01

Intensive medical care at premature born infants is often associated with separation of neonates from their mothers. Here, early artificial prolonged separation of rat pups from their dams (Maternal Deprivation, MD) was used to study potential impact on morphological lung maturation. Furthermore, we investigated the influence of an endogenous deficiency of the neuropeptide-cleaving dipeptidyl peptidase IV (DPP4), since the effects of MD are known to be partly mediated via neuropeptidergic effects, hypothesizing that MD will lead to a retardation of postnatal lung development, DPP4-dependendly. We used wild type and CD26/DPP4 deficient rats. For MD, the dam was placed each day into a separate cage for 2 h, while the pups remained in the nest on their own. Morphological lung maturation and cell proliferation at the postnatal days 7, 10, 14, and 21 were determined morphometrically. Maternally deprived wild types showed a retarded postnatal lung development compared with untreated controls in both substrains. During alveolarization, an increased thickness of alveolar septa and a decreased surface of septa about 50% were found. At the end of the morphological lung maturation, the surface of the alveolar septa was decreased at about 25% and the septal thickness remained increased about 20%. The proliferation rate was also decreased about 50% on day 14. However, the MD induced effects were less pronounced in DPP4-deficient rats, due to a significant deceleration already induced by DPP4-deficiency. Thus, MD as a model for postnatal stress experience influences remarkably postnatal development of rats, which is significantly modulated by the DPP4-system. Copyright © 2013 Wiley Periodicals, Inc.

Estimating traffic volume on Wyoming low volume roads using linear and logistic regression methods

Directory of Open Access Journals (Sweden)

Dick Apronti

2016-12-01

Full Text Available Traffic volume is an important parameter in most transportation planning applications. Low volume roads make up about 69% of road miles in the United States. Estimating traffic on the low volume roads is a cost-effective alternative to taking traffic counts. This is because traditional traffic counts are expensive and impractical for low priority roads. The purpose of this paper is to present the development of two alternative means of cost-effectively estimating traffic volumes for low volume roads in Wyoming and to make recommendations for their implementation. The study methodology involves reviewing existing studies, identifying data sources, and carrying out the model development. The utility of the models developed were then verified by comparing actual traffic volumes to those predicted by the model. The study resulted in two regression models that are inexpensive and easy to implement. The first regression model was a linear regression model that utilized pavement type, access to highways, predominant land use types, and population to estimate traffic volume. In verifying the model, an R2 value of 0.64 and a root mean square error of 73.4% were obtained. The second model was a logistic regression model that identified the level of traffic on roads using five thresholds or levels. The logistic regression model was verified by estimating traffic volume thresholds and determining the percentage of roads that were accurately classified as belonging to the given thresholds. For the five thresholds, the percentage of roads classified correctly ranged from 79% to 88%. In conclusion, the verification of the models indicated both model types to be useful for accurate and cost-effective estimation of traffic volumes for low volume Wyoming roads. The models developed were recommended for use in traffic volume estimations for low volume roads in pavement management and environmental impact assessment studies.

Relationship of maternal mean platelet volume with fetal Doppler parameters and neonatal complications in pregnancies with and without intrauterine growth restriction.

Science.gov (United States)

Ureyen, Isin; Ozyuncu, Ozgur; Sahin-Uysal, Nihal; Kara, Ozgur; Basaran, Derman; Turgal, Mert; Deren, Ozgur

2017-02-01

In this study, we investigated the relationship of mean platelet volume (MPV) with the presence and the severity of intrauterine growth restriction (IUGR) and with neonatal complications. The pregnancies with and without IUGR, that were followed-up in our hospital between 2003 and 2009 were analyzed retrospectively. Pregnancies which resulted in birth of a newborn with a birthweight less than 10th percentile for the gestational age were selected for IUGR group. IUGR cases were divided into three groups according to the Doppler parameters. There was no significant difference between the MPV values in the groups. There was no association between MPV and Doppler parameters that can be used in predicting the severity of IUGR. There was no significant relation between MPV and the perinatal complications such as intracranial hemorrhage (ICH), bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC), the development of sepsis, postpartum exitus (PPEX) and intrauterine exitus (IUEX). Higher MPV values were associated with hospitalization in the neonatal intensive care unit (NICU) and respiratory distress syndrome (RDS) in the IUGR group. Analysis of MPV is a simple and readily available laboratory test. Prospective researches employing standard measurement technics are required to clarify the relationship between MPV and IUGR.

Evaluation of brake parameters in copper discs of various thicknesses and speeds using Neodymium – Iron – Boron Magnets

Directory of Open Access Journals (Sweden)

Anantha Krishna G. L.

2018-01-01

Full Text Available Neodymium – Iron – Boron (NdFeB permanent magnets of 12.5 mm thickness and 50 mm diameter are chosen for analyses because of their higher remanence and coercivity. Experimental analyses were carried out with Copper discs of thickness 4 mm, 6 mm and 8 mm at 2000 rpm, 3000 rpm, 4000 rpm and 5000 rpm. Experiments were conducted with three different positions of magnets such as 2 coaxial magnets, single magnet and single magnet with sudden application conditions. The brake parameters recorded are % speed reduction, deceleration and time taken. In 2 coaxial magnets condition, brake parameters are better in 6 mm thick disc. In single magnet condition, the brake parameters in 6 mm thick disc are found to be more consistent than 4 mm and 8 mm thick discs. In single magnet with sudden application condition, in 4 mm thick disc, the brake parameters are found better. During analysis, very high repulsion was experienced by magnet with 8 mm thick Copper disc at all the above mentioned speeds in single magnet with sudden application condition. For high speed train applications, single magnet condition with 6mm thick disc may be suitable. For high speed automotive applications, single magnet with sudden application condition with 4 mm thick disc may be suitable.

Design parameters and source terms: Volume 2, Source terms: Revision 0

International Nuclear Information System (INIS)

1987-10-01

The Design Parameters and Source Terms Document was prepared in accordance with DOE request and to provide data for the environmental impact study to be performed in the future for the Deaf Smith County, Texas site for a nuclear waste repository in salt. This document updates a previous unpublished report by Stearns Catalytic Corporation (SCC), entitled ''Design Parameters and Source Terms for a Two-Phase Repository Salt,'' 1985, to the level of the Site Characterization Plan - Conceptual Design Report. The previous unpublished SCC Study identifies the data needs for the Environmental Assessment effort for seven possible Salt Repository sites. 2 tabs

Cell kinetic parameters of a solid mammary adenocarcinoma

International Nuclear Information System (INIS)

Porschen, R.; Feinendegen, L.E.

1978-01-01

Several cell kinetic parameters of the mammary adenocarcinoma EO 771 were evaluated by means of tumor volume measurements and of 125 I-UdR. The in-situ measured activity loss rate is disturbed by a slow elimination of labelled necrotic cells and by reutilization of 125 I-UdR. The restrictions of the I-UdR method are mentioned and the measured activity loss rates are compared with calculated volume loss rates. (orig./MG) [de

Preliminary Investigation into Tree Dryness in Hevea brasiliensis (Wild. Ex Adr. De Juss Muell. Arg. by Path Analysis of Tree Dryness and Latex Parameters

Directory of Open Access Journals (Sweden)

Omokhafe, KO.

2001-01-01

Full Text Available The correlative path analysis between tree dryness and four latex parameters was studied in eleven clones of Hevea brasiliensis. The latex parameters used for evaluation were initial volume, initial flow rate, final volume and plugging index with tree dryness as the dependent factor. Estimates of direct and indirect effects of each of the latex parameters on tree dryness were calculated through linear correlation and path analysis. The correlation coefficient between initial volume and initial flow rate was 1.00 and both characters had the same correlation coefficients with other latex parameters and tree dryness. This implies that initial volume and initial flow rate are alternatives for evaluation of correlation between latex parameters and tree dryness. There was significant correlation between initial volume, initial flow rate and tree dryness at V = -0.52 and high indirect effect of initial volume and initial flow rate through final volume. In addition, despite the low correlation coefficient of V = -0.20 between final volume and tree dryness, the direct effect of final volume on tree dryness was high at 0.812. Final volume is therefore an important factor in the incidence of tree dryness.

Microarchitecture Parameters Describe Bone Structure and Its Strength Better Than BMD

Directory of Open Access Journals (Sweden)

Tomasz Topoliński

2012-01-01

Full Text Available Introduction and Hypothesis. Some papers have shown that bone mineral density (BMD may not be accurate in predicting fracture risk. Recently microarchitecture parameters have been reported to give information on bone characteristics. The aim of this study was to find out if the values of volume, fractal dimension, and bone mineral density are correlated with bone strength. Methods. Forty-two human bone samples harvested during total hip replacement surgery were cut to cylindrical samples. The geometrical mesh of layers of bone mass obtained from microCT investigation and the volumes of each layer and fractal dimension were calculated. The finite element method was applied to calculate the compression force F causing ε=0.8% strain. Results. There were stronger correlations for microarchitecture parameters with strength than those for bone mineral density. The values of determination coefficient R2 for mean volume and force were 0.88 and 0.90 for mean fractal dimension and force, while for BMD and force the value was 0.53. The samples with bigger mean bone volume of layers and bigger mean fractal dimension of layers (more complex structure presented higher strength. Conclusion. The volumetric and fractal dimension parameters better describe bone structure and strength than BMD.

Effects of Anti-VEGF on Predicted Antibody Biodistribution: Roles of Vascular Volume, Interstitial Volume, and Blood Flow

Science.gov (United States)

Boswell, C. Andrew; Ferl, Gregory Z.; Mundo, Eduardo E.; Bumbaca, Daniela; Schweiger, Michelle G.; Theil, Frank-Peter; Fielder, Paul J.; Khawli, Leslie A.

2011-01-01

Background The identification of clinically meaningful and predictive models of disposition kinetics for cancer therapeutics is an ongoing pursuit in drug development. In particular, the growing interest in preclinical evaluation of anti-angiogenic agents alone or in combination with other drugs requires a complete understanding of the associated physiological consequences. Methodology/Principal Findings Technescan™ PYP™, a clinically utilized radiopharmaceutical, was used to measure tissue vascular volumes in beige nude mice that were naïve or administered a single intravenous bolus dose of a murine anti-vascular endothelial growth factor (anti-VEGF) antibody (10 mg/kg) 24 h prior to assay. Anti-VEGF had no significant effect (p>0.05) on the fractional vascular volumes of any tissues studied; these findings were further supported by single photon emission computed tomographic imaging. In addition, apart from a borderline significant increase (p = 0.048) in mean hepatic blood flow, no significant anti-VEGF-induced differences were observed (p>0.05) in two additional physiological parameters, interstitial fluid volume and the organ blood flow rate, measured using indium-111-pentetate and rubidium-86 chloride, respectively. Areas under the concentration-time curves generated by a physiologically-based pharmacokinetic model changed substantially (>25%) in several tissues when model parameters describing compartmental volumes and blood flow rates were switched from literature to our experimentally derived values. However, negligible changes in predicted tissue exposure were observed when comparing simulations based on parameters measured in naïve versus anti-VEGF-administered mice. Conclusions/Significance These observations may foster an enhanced understanding of anti-VEGF effects in murine tissues and, in particular, may be useful in modeling antibody uptake alone or in combination with anti-VEGF. PMID:21436893

Blood volume studies in chronic renal failure using radioactive 51Cr

International Nuclear Information System (INIS)

Chadda, V.S.; Mehta, S.R.; Mathur, D.

1975-01-01

Estimation of blood volume was carried out in 20 healthy subjects and in 25 patients suffering from chronic renal failure using radioactive 51 Cr. A detailed history, physical examination and investigations were also undertaken. On statistical evaluation, the red cell volume was diminished significantly in males and females but rise in blood volume was insignificant. Plasma volume was raised significantly in females but was insignificant in males. The reduction in red cell volume is due to reduced red cell mass because of chronic renal disease. Plasma volume may be elevated in order to compensate for decreased red cell volume. The variability in these two parameters results in variable blood volume. (author)

Influence of the choice of parameters of the TAC in the calculation of volumes for different planners

International Nuclear Information System (INIS)

Sanchez Mazon, J.; Raba Diez, J. L.; Vazquez Rodriguez, J. A.; Pacheco Baldor, M. T.; Mendiguren Santiago, M. A.

2011-01-01

In the Protocol for the control treatment planning systems with ionizing radiation of the proposed SEFM tests to verify proper operation of the calculation in the evaluation of DVH (Dose Volume Histogram). The calculation of the volume that makes a planner may have important implications because it can trigger an overestimation of the dose or otherwise. We present a comparison of the calculation of volumes estimated with 4 different planners.

Measurable inhomogeneities in stock trading volume flow

Science.gov (United States)

Cortines, A. A. G.; Riera, R.; Anteneodo, C.

2008-08-01

We investigate the statistics of volumes of shares traded in stock markets. We show that the stochastic process of trading volumes can be understood on the basis of a mixed Poisson process at the microscopic time level. The beta distribution of the second kind (also known as q-gamma distribution), that has been proposed to describe empirical volume histograms, naturally results from our analysis. In particular, the shape of the distribution at small volumes is governed by the degree of granularity in the trading process, while the exponent controlling the tail is a measure of the inhomogeneities in market activity. Furthermore, the present case furnishes empirical evidence of how power law probability distributions can arise as a consequence of a fluctuating intrinsic parameter.

Stereological estimation of nuclear volume and other quantitative histopathological parameters in the prognostic evaluation of supraglottic laryngeal squamous cell carcinoma

DEFF Research Database (Denmark)

Sørensen, Flemming Brandt; Bennedbaek, O; Pilgaard, J

1989-01-01

The aim of this study was to investigate various approaches to the grading of malignancy in pre-treatment biopsies from patients with supraglottic laryngeal squamous cell carcinoma. The prospects of objective malignancy grading based on stereological estimation of the volume-weighted mean nuclear...... observers of the latter was poor in the material which consisted of 35 biopsy specimens. Unbiased estimates of nuclear Vv were on the average 385 microns3 (CV = 0.44), with more than 90% of the associated variance attributable to differences in nuclear Vv among individual lesions. Nuclear Vv was positively....... None of the investigated categorical and quantitative parameters (cutoff points = means) reached the level of significance with respect to prognostic value. However, nuclear Vv showed the best information concerning survival (2p = 0.08), and this estimator offers optimal features for objective...

Assessment of histological response of paediatric bone sarcomas using FDG PET in comparison to morphological volume measurement and standardized MRI parameters

Energy Technology Data Exchange (ETDEWEB)

Denecke, Timm; Misch, Daniel; Steffen, Ingo G.; Plotkin, Michail; Stoever, Brigitte [Charite - Universitaetsmedizin Berlin, Klinik fuer Strahlenheilkunde, Campus Virchow-Klinikum, Berlin (Germany); Hundsdoerfer, Patrick; Henze, Guenter [Charite - Universitaetsmedizin Berlin, Klinik fuer Paediatrie m.S. Onkologie und Haematologie, Otto-Heubner-Zentrum, Campus Virchow-Klinikum, Berlin (Germany); Schoenberger, Stefan [Universitaetsklinikum der Heinrich-Heine-Universitaet Duesseldorf, Klinik fuer Kinder-Onkologie, -Haematologie und -Immunologie, Duesseldorf (Germany); Furth, Christian; Ruf, Juri [Otto-von-Guericke-Universitaet Magdeburg, Klinik fuer Radiologie und Nuklearmedizin, Universitaetsklinikum Magdeburg A.oe.R., Magdeburg (Germany); Hautzel, Hubertus [Universitaetsklinikum der Heinrich Heine Universitaet Duesseldorf, Nuklearmedizinische Klinik, Duesseldorf (Germany); Kluge, Regine [Universitaetsklinikum Leipzig A.oe.R., Klinik und Poliklinik fuer Nuklearmedizin, Leipzig (Germany); Bierbach, Uta [Universitaetsklinikum Leipzig A.oe.R., Abteilung fuer Kinder-Haematologie, -Onkologie und -Haemostaseologie, Leipzig (Germany); Otto, Sylke [Universitaetsklinikum Greifswald, Institut fuer Diagnostische Radiologie und Neuroradiologie, Greifswald (Germany); Beck, James F. [Universitaetsklinikum Greifswald, Abteilung fuer Paediatrische Haematologie und Onkologie, Greifswald (Germany); Franzius, Christiane [MR- und PET/CT-Zentrum, Bremen-Mitte (Germany); Universitaetsklinikum Muenster, Klinik und Poliklinik fuer Nuklearmedizin, Muenster (Germany); Amthauer, Holger [Charite - Universitaetsmedizin Berlin, Klinik fuer Strahlenheilkunde, Campus Virchow-Klinikum, Berlin (Germany); Otto-von-Guericke-Universitaet Magdeburg, Klinik fuer Radiologie und Nuklearmedizin, Universitaetsklinikum Magdeburg A.oe.R., Magdeburg (Germany)

2010-10-15

The objective of this study was to evaluate positron emission tomography (PET) using {sup 18}F-fluoro-2-deoxy-D-glucose (FDG) in comparison to volumetry and standardized magnetic resonance imaging (MRI) parameters for the assessment of histological response in paediatric bone sarcoma patients. FDG PET and local MRI were performed in 27 paediatric sarcoma patients [Ewing sarcoma family of tumours (EWS), n = 16; osteosarcoma (OS), n = 11] prior to and after neoadjuvant chemotherapy before local tumour resection. Several parameters for assessment of response of the primary tumour to therapy by FDG PET and MRI were evaluated and compared with histopathological regression of the resected tumour as defined by Salzer-Kuntschik. FDG PET significantly discriminated responders from non-responders using the standardized uptake value (SUV) reduction and the absolute post-therapeutic SUV (SUV2) in the entire patient population ({nabla}SUV, p = 0.005; SUV2, p = 0.011) as well as in the subgroup of OS patients ({nabla}SUV, p = 0.009; SUV2, p = 0.028), but not in the EWS subgroup. The volume reduction measured by MRI/CT did not significantly discriminate responders from non-responders either in the entire population (p = 0.170) or in both subgroups (EWS, p = 0.950; OS, p = 1.000). The other MRI parameters alone or in combination were unreliable and did not improve the results. Comparing diagnostic parameters of FDG PET and local MRI, metabolic imaging showed high superiority in the subgroup of OS patients, while similar results were observed in the population of EWS. FDG PET appears to be a useful tool for non-invasive response assessment in the group of OS patients and is superior to MRI. In EWS patients, however, neither FDG PET nor volumetry or standardized MRI criteria enabled a reliable response assessment to be made after neoadjuvant treatment. (orig.)

Determination of the autonomously functioning volume of the thyroid

International Nuclear Information System (INIS)

Emrich, D.; Erlenmaier, U.; Pohl, M.; Luig, H.

1993-01-01

The aim of this work was to determine the autonomously functioning volume in euthyroid and hyperthyroid goitres for prognostic and therapeutic pruposes. To this end, various groups of patients were selected: Individuals without evidence of thyroid disease, euthyroid patients with diffuse goitre of normal structure and function, euthyroid patients with evidence of autonomy and patients with hyperthyroidism due to autonomy. In all of them the thyroid uptake of Technetium-99m was determined under exogeneous suppression (TcU s ) in the euthyroid state and under endogenous suppression (TcU) in the hyperthyroid state. It was demonstrated that: 1. In patients with unifocal autonomy the TcU s and TcU correlated linearly with the autonomous volume delineated and measured by sonography. 2. A nearly identical result was obtained if the mean autonomous volume in individuals without thyroid disease of 2.2±1.1 ml calculated by TcU s /TcU x total thyroid volume was used as a basis. 3. The critical autonomous volume, i.e. the volume at which hyperthryroidism will occur, was found to be 16 ml at a cumulated sensitivity and specificity of >0.9. The method can be used to select patients for definitive treatment before hyperthryroidism occurs and to measure the autonomously functioning volume independent of its distribution within the thyroid for treatment with radioiodine. The method is easy to perform and is also an example of how a relative parameter of a function can be converted into an absolute parameter of a functioning volume. (orig.)

Volume dependence of Grüneisen parameter for solids under

Indian Academy of Sciences (India)

2016-07-09

Jul 9, 2016 ... 1School of Physics and Materials Science, P.O. Box 32, Bhadson Road, Thapar University,. Patiala 147 004, India. 2Shivalik Institute of Engineering and Technology, ... The knowledge of Grüneisen parameter is also required for investigating the melting curves from Lindemann–. Gilvarry criterion [1,2].

Group Analysis of Free Convection Flow of a Magnetic Nanofluid with Chemical Reaction

Directory of Open Access Journals (Sweden)

Md. Jashim Uddin

2015-01-01

Full Text Available A theoretical study of two-dimensional magnetohydrodynamics viscous incompressible free convective boundary layer flow of an electrically conducting, chemically reacting nanofluid from a convectively heated permeable vertical surface is presented. Scaling group of transformations is used in the governing equations and the boundary conditions to determine absolute invariants. A third-order ordinary differential equation which corresponds to momentum conservation and two second-order ordinary differential equations which correspond to energy and nanoparticle volume fraction (species conservation are derived. Our (group analysis indicates that, for the similarity solution, the convective heat transfer coefficient and mass transfer velocity are proportional to x-1/4 whilst the reaction rate is proportional to x-1/2, where x is the axial distance from the leading edge of the plate. The effects of the relevant controlling parameters on the dimensionless velocity, temperature, and nanoparticle volume fraction are examined. The accuracy of the technique we have used was tested by performing comparisons with the results of published work and the results were found to be in good agreement. The present computations indicate that the flow is accelerated and temperature enhanced whereas nanoparticle volume fractions are decreased with increasing order of chemical reaction. Furthermore the flow is strongly decelerated, whereas the nanoparticle volume fraction and temperature are enhanced with increasing magnetic field parameter. Increasing convection-conduction parameter increases velocity and temperatures but has a weak influence on nanoparticle volume fraction distribution. The present study demonstrates the thermal enhancement achieved with nanofluids and also magnetic fields and is of relevance to nanomaterials processing.

Spatio-temporal modeling of nonlinear distributed parameter systems

CERN Document Server

Li, Han-Xiong

2011-01-01

The purpose of this volume is to provide a brief review of the previous work on model reduction and identifi cation of distributed parameter systems (DPS), and develop new spatio-temporal models and their relevant identifi cation approaches. In this book, a systematic overview and classifi cation on the modeling of DPS is presented fi rst, which includes model reduction, parameter estimation and system identifi cation. Next, a class of block-oriented nonlinear systems in traditional lumped parameter systems (LPS) is extended to DPS, which results in the spatio-temporal Wiener and Hammerstein s

Recommendations from gynaecological (GYN) GEC ESTRO working group (II): Concepts and terms in 3D image-based treatment planning in cervix cancer brachytherapy-3D dose volume parameters and aspects of 3D image-based anatomy, radiation physics, radiobiology

International Nuclear Information System (INIS)

Poetter, Richard; Haie-Meder, Christine; Limbergen, Erik van; Barillot, Isabelle; Brabandere, Marisol De; Dimopoulos, Johannes; Dumas, Isabelle; Erickson, Beth; Lang, Stefan; Nulens, An; Petrow, Peter; Rownd, Jason; Kirisits, Christian

2006-01-01

The second part of the GYN GEC ESTRO working group recommendations is focused on 3D dose-volume parameters for brachytherapy of cervical carcinoma. Methods and parameters have been developed and validated from dosimetric, imaging and clinical experience from different institutions (University of Vienna, IGR Paris, University of Leuven). Cumulative dose volume histograms (DVH) are recommended for evaluation of the complex dose heterogeneity. DVH parameters for GTV, HR CTV and IR CTV are the minimum dose delivered to 90 and 100% of the respective volume: D90, D100. The volume, which is enclosed by 150 or 200% of the prescribed dose (V150, V200), is recommended for overall assessment of high dose volumes. V100 is recommended for quality assessment only within a given treatment schedule. For Organs at Risk (OAR) the minimum dose in the most irradiated tissue volume is recommended for reporting: 0.1, 1, and 2 cm 3 ; optional 5 and 10 cm 3 . Underlying assumptions are: full dose of external beam therapy in the volume of interest, identical location during fractionated brachytherapy, contiguous volumes and contouring of organ walls for >2 cm 3 . Dose values are reported as absorbed dose and also taking into account different dose rates. The linear-quadratic radiobiological model-equivalent dose (EQD 2 )-is applied for brachytherapy and is also used for calculating dose from external beam therapy. This formalism allows systematic assessment within one patient, one centre and comparison between different centres with analysis of dose volume relations for GTV, CTV, and OAR. Recommendations for the transition period from traditional to 3D image-based cervix cancer brachytherapy are formulated. Supplementary data (available in the electronic version of this paper) deals with aspects of 3D imaging, radiation physics, radiation biology, dose at reference points and dimensions and volumes for the GTV and CTV (adding to [Haie-Meder C, Poetter R, Van Limbergen E et al

The irradiation lung volume in tangential fields for the treatment of a breast

International Nuclear Information System (INIS)

Oh, Y. T.; Kim, J. R.; Kang, H. J.; Sohn, J. H.; Kang, S. H.; Chun, M. S.

1997-01-01

Radiation pneumonitis is one of the complications caused by radiation therapy that includes a portion of the lung tissue. The severity of radiation induced pulmonary dysfunction depends on the irradiated lung volume, total dose, dose rate and underlying pulmonary function. The lung volume was measured for 25 patients with breast cancer irradiated with tangential field from Jan. 1995 to Aug. 1996. Parameters that can predict the irradiated lung volume included; (1) the perpendicular distance from the posterior tangential edge to the posterior part of the anterior chest wall at the center of the field (CLD); (2) the maximum perpendicular distance from the posterior tangential field edge to the posterior part of the anterior chest wall (MLD); (3) the greatest perpendicular distance from the posterior tangential edge to the posterior part of anterior chest wall on CT image at the center of the longitudinal field (GPD); (4) the length of the longitudinal field (L). The irradiated lung volume(RV), the entire both lung volume(EV) and the ipsilateral lung volume(IV) were measured using dose volume histogram. The RV is 61-279cc, the RV/EV is 2.9-13.0% and the RV/EN is 4.9-29.6%. The CLD, the MLD and the GPD are 1.9-3.3cm and 1.4-3.1cm respectively. The significant relations between the irradiated lung volume such as RV, RV/EV, RV/IV and parameters such as CLD, MLD, GPD, L, CLD x L, MLD x L and GPD x L are not found with little variances in parameters. The RV/IV of the left breast irradiation is significances. The significant relationship between the irradiated lung volume and predictors is not found with little variation on parameters. The irradiated lung volume in the tangential field is less than 10% of entire lung volume when CLD is less than 3cm. The RV/IV of the left tangential field is larger than that of the right but there was no significant differences in RV/EVs. Symptomatic radiation pneumonitis has not occurred during minimum 6 months follow up. (author)

Volume of a laser-induced microjet

Science.gov (United States)

Kawamoto, Sennosuke; Hayasaka, Keisuke; Noguchi, Yuto; Tagawa, Yoshiyuki

2015-11-01

Needle-free injection systems are of great importance for medical treatments. In spite of their great potential, these systems are not commonly used. One of the common problems is strong pain caused by diffusion shape of the jet. To solve this problem, the usage of a high-speed highly-focused microjet as needle-free injection system is expected. It is thus crucial to control important indicators such as ejected volume of the jet for its safe application. We conduct experiments to reveal which parameter influences mostly the ejected volume. In the experiments, we use a glass tube of an inner diameter of 500 micro-meter, which is filled with the liquid. One end is connected to a syringe and the other end is opened. Radiating the pulse laser instantaneously vapors the liquid, followed by the generation of a shockwave. We find that the maximum volume of a laser-induced bubble is approximately proportional to the ejected volume. It is also found that the occurrence of cavitation does not affect the ejected volume while it changes the jet velocity.

113Insup(m) radiocardiographic measurements of cardiopulmonary parameters in healthy subjects and in cardiac patients

International Nuclear Information System (INIS)

Kuikka, Jyrki.

1976-05-01

Single detector arrangements are used to measure heart radioactivity curves in healthy subjects and in patients with various heart failures. A method is developed from a modified gamma function to determine the cardiopulmonary parameters from the radiocardiograms: systemic flow, pulmonary flow, right to left shunting flow, left to right shunting flow, regurgitant fractions, stroke volume, atrial blood volumes, ventricular end-diastolic volumes, pulmonary blood volume and ejection fractions. The method is well suited to clinical routine and requires only a desk calculator or a mini-computer for data handling. The cardiopulmonary parameters were measured from 70 healthy subjects with following results: cardiac index 3.46+-0.72 l/min/m 2 , stroke index 49+-9 ml/b/m 2 , right atrial blood volume 35+-13 ml/m 2 , right ventricular end-diastolic volume 76+-15 ml/m 2 , pulmonary blood volume 250+-51 ml/m 2 , left atrial blood volume 41+-15 ml/m 2 , left ventricular end-diastolic volume 75+-15 ml/m 2 , right heart ejection fraction 0.64+-0.11, left heart ejection fraction 0.66+-0.12. These values agree closely with the data accumulated from more elaborate methods. (author)

Anthropometric parameters: weight height, body mass index and mammary volume in relationship with the mammographic pattern

International Nuclear Information System (INIS)

Perez-Candela, V.; Busto, C.; Avila, R.; Marrero, M. G.; Liminana, J. M.; Orengo, J. C.

2001-01-01

A prospective study to attempt to relate the anthropometric parameters of height, weight, body mass index as well as age with the mammographic patterns obtained for the patients and obtain an anthropometric profile was carried out. The study was performed in 1.000 women who underwent a mammography in cranial-caudal and medial lateral oblique projection of both breasts, independently of whether they were screened or diagnosed. Prior to the performance of the mammography, weight and height were obtained, and this was also performed by the same technicians, and the patient were asked their bra size to deduce breast volume. With the weight, the body mass index of Quetelet was calculated (weight [kg]/height''2 (ml). After reading the mammography, the patient was assigned to one of the four mammographic patterns considered in the BIRADS (Breast Imaging Reporting and Data System) established by the ACR (American College of Radiology): type I (fat). type II (disperse fibroglandular densities), type III (fibroglandular densities distributed heterogeneously), type 4 (dense). The results were introduced into a computer database and the SPSS 8.0 statistical program was applied, using the statistical model of multivariant logistic regression. In women under 40 years, with normal weight, the dense breast pattern accounted for 67.8% and as the body mass index (BMI) increased, this pattern decreased to 25.1%. The fat pattern is 20% and as the BMI increases, this increased to 80%. In 40-60 year old women with normal weight, the dense pattern accounts for 44% and decreases to 20.9% in the grades II, III and IV obese. The fat pattern is 11.1% and increases to 53.7% in the grade II, III and IV obese. In women over 60 with normal, the dense pattern accounts for 19.3% and and decreases to 13% in the grade III obese. The fat pattern is 5.3% and increases to 20.2% in the grade iii of obesity. As age increases, the probability of presenting a mammographic pattern with a fat image in the

A finite volume solver for three dimensional debris flow simulations based on a single calibration parameter

Science.gov (United States)

von Boetticher, Albrecht; Turowski, Jens M.; McArdell, Brian; Rickenmann, Dieter

2016-04-01

Debris flows are frequent natural hazards that cause massive damage. A wide range of debris flow models try to cover the complex flow behavior that arises from the inhomogeneous material mixture of water with clay, silt, sand, and gravel. The energy dissipation between moving grains depends on grain collisions and tangential friction, and the viscosity of the interstitial fine material suspension depends on the shear gradient. Thus a rheology description needs to be sensitive to the local pressure and shear rate, making the three-dimensional flow structure a key issue for flows in complex terrain. Furthermore, the momentum exchange between the granular and fluid phases should account for the presence of larger particles. We model the fine material suspension with a Herschel-Bulkley rheology law, and represent the gravel with the Coulomb-viscoplastic rheology of Domnik & Pudasaini (Domnik et al. 2013). Both composites are described by two phases that can mix; a third phase accounting for the air is kept separate to account for the free surface. The fluid dynamics are solved in three dimensions using the finite volume open-source code OpenFOAM. Computational costs are kept reasonable by using the Volume of Fluid method to solve only one phase-averaged system of Navier-Stokes equations. The Herschel-Bulkley parameters are modeled as a function of water content, volumetric solid concentration of the mixture, clay content and its mineral composition (Coussot et al. 1989, Yu et al. 2013). The gravel phase properties needed for the Coulomb-viscoplastic rheology are defined by the angle of repose of the gravel. In addition to this basic setup, larger grains and the corresponding grain collisions can be introduced by a coupled Lagrangian particle simulation. Based on the local Savage number a diffusive term in the gravel phase can activate phase separation. The resulting model can reproduce the sensitivity of the debris flow to water content and channel bed roughness, as

[Diagnostic value of quantitative pharmacokinetic parameters and relative quantitative pharmacokinetic parameters in breast lesions with dynamic contrast-enhanced MRI].

Science.gov (United States)

Sun, T T; Liu, W H; Zhang, Y Q; Li, L H; Wang, R; Ye, Y Y

2017-08-01

Objective: To explore the differential between the value of dynamic contrast-enhanced MRI quantitative pharmacokinetic parameters and relative pharmacokinetic quantitative parameters in breast lesions. Methods: Retrospective analysis of 255 patients(262 breast lesions) who was obtained by clinical palpation , ultrasound or full-field digital mammography , and then all lessions were pathologically confirmed in Zhongda Hospital, Southeast University from May 2012 to May 2016. A 3.0 T MRI scanner was used to obtain the quantitative MR pharmacokinetic parameters: volume transfer constant (K(trans)), exchange rate constant (k(ep))and extravascular extracellular volume fraction (V(e)). And measured the quantitative pharmacokinetic parameters of normal glands tissues which on the same side of the same level of the lesions; and then calculated the value of relative pharmacokinetic parameters: rK(rans)、rk(ep) and rV(e).To explore the diagnostic value of two pharmacokinetic parameters in differential diagnosis of benign and malignant breast lesions using receiver operating curves and model of logistic regression. Results: (1)There were significant differences between benign lesions and malignant lesions in K(trans) and k(ep) ( t =15.489, 15.022, respectively, P 0.05). The areas under the ROC curve(AUC)of K(trans), k(ep) and V(e) between malignant and benign lesions were 0.933, 0.948 and 0.387, the sensitivity of K(trans), k(ep) and V(e) were 77.1%, 85.0%, 51.0% , and the specificity of K(trans), k(ep) and V(e) were 96.3%, 93.6%, 60.8% for the differential diagnosis of breast lesions if taken the maximum Youden's index as cut-off. (2)There were significant differences between benign lesions and malignant lesions in rK(trans), rk(ep) and rV(e) ( t =14.177, 11.726, 2.477, respectively, P quantitative pharmacokinetic parameters and the prediction probability of relative quantitative pharmacokinetic parameters( Z =0.867, P =0.195). Conclusion: There was no significant

Anogenital distance and reproductive parameters in young men

DEFF Research Database (Denmark)

Parra, M D; Mendiola, J; Jørgensen, N

2016-01-01

) and to the cephalad insertion of the penis (AGDAP )] were assessed in 215 university students. Semen parameters (semen volume, sperm concentration, total sperm counts, motility and morphology) and serum reproductive hormones (follicle stimulating hormone, luteinising hormone, inhibin B, testosterone, calculated free...

Haematological and Serum Bio-Chemical Parameters of West ...

African Journals Online (AJOL)

Haematological and Serum Bio-Chemical Parameters of West African Dwarf and Kalahari Red Goats in the Humid Tropics. ... Haematological results showed that white blood cell count, haemoglobin concentration, haematocrit, mean corpuscular volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin ...

Focused attention, heart rate deceleration, and cognitive development in preterm and full-term infants.

Science.gov (United States)

Petrie Thomas, Julianne H; Whitfield, Michael F; Oberlander, Tim F; Synnes, Anne R; Grunau, Ruth E

2012-05-01

The majority of children who are born very preterm escape major impairment, yet more subtle cognitive and attention problems are very common in this population. Previous research has linked infant focused attention during exploratory play to later cognition in children born full-term and preterm. Infant focused attention can be indexed by sustained decreases in heart rate (HR). However there are no preterm studies that have jointly examined infant behavioral attention and concurrent HR response during exploratory play in relation to developing cognition. We recruited preterm infants free from neonatal conditions associated with major adverse outcomes, and further excluded infants with developmental delay (Bayley Mental Development Index [MDI attention and concurrent HR response were compared in 83 preterm infants (born 23-32 weeks gestational age [GA]) who escaped major impairment to 46 full-term infants. Focused attention and HR response were then examined in relation to Bayley MDI, after adjusting for neonatal risk. MDI did not differ by group, yet full-term infants displayed higher global focused attention ratings. Among the extremely preterm infants born attention episodes, accounted for 49% of adjusted variance in predicting concurrent MDI. There were no significant associations for later-born gestational age (29-32 weeks) or full-term infants. Among extremely preterm infants who escape major impairment, our findings suggest unique relationships between focused attention, HR deceleration, and developing cognition. Copyright © 2011 Wiley Periodicals, Inc.

Influence of technical parameters on epicardial fat volume quantification at cardiac CT

International Nuclear Information System (INIS)

Bucher, Andreas M.; Joseph Schoepf, U.; Krazinski, Aleksander W.; Silverman, Justin; Spearman, James V.; De Cecco, Carlo N.; Meinel, Felix G.; Vogl, Thomas J.; Geyer, Lucas L.

2015-01-01

Highlights: • Upper threshold levels and contrast enhancement influence epicardial fat volumetry. • Cardiac cycle does not significantly influence epicardial fat volumetry. • Adjustments of upper threshold can lead to comparable volumetry results. - Abstract: Objectives: To systematically analyze the influence of technical parameters on quantification of epicardial fat volume (EATV) at cardiac CT. Methods: 153 routine cardiac CT data sets were analyzed using three-dimensional pericardial border delineation. Three image series were reconstructed per patient: (a) CTA D : coronary CT angiography (CTA), diastolic phase; (b) CTA S : coronary CTA, systolic phase; (c) CaSc D : non-contrast CT, diastolic phase. EATV was calculated using three different upper thresholds (−15HU, −30HU, −45HU). Repeated measures ANOVA, Spearman's rho, and Bland Altman plots were used. Results: Mean EATV differed between all three image series at a −30HU threshold (CTA D 87.2 ± 38.5 ml, CTA S 90.9 ± 37.7 ml, CaSc D 130.7 ± 49.5 ml, P < 0.001). EATV of diastolic and systolic CTA reconstructions did not differ significantly (P = 0.225). Mean EATV for contrast enhanced CTA at a −15HU threshold (CTA D15 102.4 ± 43.6 ml, CTA S15 105.3 ± 42.3 ml) could be approximated most closely by non-contrast CT at −45HU threshold (CaSc D45 105.3 ± 40.8 ml). The correlation was excellent: CTA S15 –CTA D15 , rho = 0.943; CTA D15 –CaSc D45 , rho = 0.905; CTA S15 –CaSc D45 , rho = 0.924; each P < 0.001). Bias values from Bland Altman Analysis were: CTA S15 –CTA D15 , 4.9%; CTA D15 –CaSc D45 , −4.3%; CTA S15 –CaSc D45 , 0.6%. Conclusions: Measured EATV can differ substantially between contrast enhanced and non-contrast CT studies, which can be reconciled by threshold modification. Heart cycle phase does not significantly influence EATV measurements

Influence of technical parameters on epicardial fat volume quantification at cardiac CT

Energy Technology Data Exchange (ETDEWEB)

Bucher, Andreas M. [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Frankfurt (Germany); Joseph Schoepf, U., E-mail: schoepf@musc.edu [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (United States); Krazinski, Aleksander W.; Silverman, Justin; Spearman, James V. [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); De Cecco, Carlo N. [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiological Sciences, Oncology and Pathology, University of Rome “Sapienza” – Polo Pontino, Latina (Italy); Meinel, Felix G. [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich (Germany); Vogl, Thomas J. [Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Frankfurt (Germany); Geyer, Lucas L. [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich (Germany)

2015-06-15

Highlights: • Upper threshold levels and contrast enhancement influence epicardial fat volumetry. • Cardiac cycle does not significantly influence epicardial fat volumetry. • Adjustments of upper threshold can lead to comparable volumetry results. - Abstract: Objectives: To systematically analyze the influence of technical parameters on quantification of epicardial fat volume (EATV) at cardiac CT. Methods: 153 routine cardiac CT data sets were analyzed using three-dimensional pericardial border delineation. Three image series were reconstructed per patient: (a) CTA{sub D}: coronary CT angiography (CTA), diastolic phase; (b) CTA{sub S}: coronary CTA, systolic phase; (c) CaSc{sub D}: non-contrast CT, diastolic phase. EATV was calculated using three different upper thresholds (−15HU, −30HU, −45HU). Repeated measures ANOVA, Spearman's rho, and Bland Altman plots were used. Results: Mean EATV differed between all three image series at a −30HU threshold (CTA{sub D} 87.2 ± 38.5 ml, CTA{sub S} 90.9 ± 37.7 ml, CaSc{sub D} 130.7 ± 49.5 ml, P < 0.001). EATV of diastolic and systolic CTA reconstructions did not differ significantly (P = 0.225). Mean EATV for contrast enhanced CTA at a −15HU threshold (CTA{sub D15} 102.4 ± 43.6 ml, CTA{sub S15} 105.3 ± 42.3 ml) could be approximated most closely by non-contrast CT at −45HU threshold (CaSc{sub D45} 105.3 ± 40.8 ml). The correlation was excellent: CTA{sub S15}–CTA{sub D15}, rho = 0.943; CTA{sub D15}–CaSc{sub D45}, rho = 0.905; CTA{sub S15}–CaSc{sub D45}, rho = 0.924; each P < 0.001). Bias values from Bland Altman Analysis were: CTA{sub S15}–CTA{sub D15}, 4.9%; CTA{sub D15}–CaSc{sub D45}, −4.3%; CTA{sub S15}–CaSc{sub D45}, 0.6%. Conclusions: Measured EATV can differ substantially between contrast enhanced and non-contrast CT studies, which can be reconciled by threshold modification. Heart cycle phase does not significantly influence EATV measurements.

Partial volume effect in MRI

International Nuclear Information System (INIS)

Maeda, Munehiro; Yoshiya, Kazuhiko; Suzuki, Eiji

1989-01-01

According to the direction and the thickness of the imaging slice in tomography, the border between the tissues becomes unclear (partial volume effect). In the present MRI experiment, we examined border area between fat and water components using phantom in order to investigate the partial volume effect in MRI. In spin echo sequences, the intensity of the border area showed a linear relationship with composition of fat and water. Whereas, in inversion recovery and field echo sequences, we found the parameters to produce an extremely low intensity area at the border region between fat and water. This low intensity area was explained by cancellation of NMR signals from fat and water due to the difference in the direction of magnetic vectors. Clinically, partial volume effect can cause of mis-evaluation of walls, small nodules, tumor capsules and the tumor invasion in the use of inversion recovery and field echo sequences. (author)

Semantics by analogy for illustrative volume visualization

NARCIS (Netherlands)

Gerl, Moritz; Rautek, Peter; Isenberg, Tobias; Groeller, Eduard

We present an interactive graphical approach for the explicit specification of semantics for volume visualization. This explicit and graphical specification of semantics for volumetric features allows us to visually assign meaning to both input and output parameters of the visualization mapping.

A fast wind-farm boundary-layer model to investigate gravity wave effects and upstream flow deceleration

Science.gov (United States)

Allaerts, Dries; Meyers, Johan

2017-11-01

Wind farm design and control often relies on fast analytical wake models to predict turbine wake interactions and associated power losses. Essential input to these models are the inflow velocity and turbulent intensity at hub height, which come from prior measurement campaigns or wind-atlas data. Recent LES studies showed that in some situations large wind farms excite atmospheric gravity waves, which in turn affect the upstream wind conditions. In the current study, we develop a fast boundary-layer model that computes the excitation of gravity waves and the perturbation of the boundary-layer flow in response to an applied force. The core of the model is constituted by height-averaged, linearised Navier-Stokes equations for the inner and outer layer, and the effect of atmospheric gravity waves (excited by the boundary-layer displacement) is included via the pressure gradient. Coupling with analytical wake models allows us to study wind-farm wakes and upstream flow deceleration in various atmospheric conditions. Comparison with wind-farm LES results shows excellent agreement in terms of pressure and boundary-layer displacement levels. The authors acknowledge support from the European Research Council (FP7-Ideas, Grant No. 306471).

A New Theory for Calculation of Some Biochemical Parameters Concentration in Human Serum

International Nuclear Information System (INIS)

Moustafa, K.A.; Amien, A.I.

2009-01-01

The serum volumes of the blood samples are varied from one patient to another according to the packed cell volume (PCV %), so if the patient sample has low PCV %, it will have high serum volume and vice versa. To calculate a certain clinical parameter such as glucose in the serum of patients using the conventional calculation, it will give the concentration in units per deci liter serum, while by calculating the concentration according to the ratio of serum volume to the total volume of the blood, it will give different results. Thus, the present study aimed to find a new theory used for calculation of some biochemical parameters concentration taking into consideration the ratio of plasma volume to the total blood volume. The present study was conducted on 122 subjects. These subjects were categorized into 4 groups. Group 1 (G1) comprised 40 healthy subjects as control group, group 2 (G2) comprised 30 low PCV % patients, group 3 (G3) comprised 30 subjects with relatively high PCV % and group 4 comprised 22 diabetic patients. Each group of the previous groups was further subdivided into group a (G a ) and group b (G b ). In the later group, the results were multiplied by the correction factor (V p /V b ), which is the ratio of plasma volume (V p ) to the blood volume (V b ) TSH hormone, glucose, cholesterol, triglycerides, urea, creatinine, uric acid, alanine aminotransferase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP) were estimated and the results were multiplied by the correction factor (V p /V b ) to get the results after correction. Compared the results before and after correction, there was a very highly significant (ρ p /V b ), thus we recommended that biochemical parameters results must be calculated as indicated in the present study to obtain actual results which might be useful in the correct diagnosis, monitoring and follow up of the different diseases

Whole-tumor histogram analysis of the cerebral blood volume map: tumor volume defined by 11C-methionine positron emission tomography image improves the diagnostic accuracy of cerebral glioma grading.

Science.gov (United States)

Wu, Rongli; Watanabe, Yoshiyuki; Arisawa, Atsuko; Takahashi, Hiroto; Tanaka, Hisashi; Fujimoto, Yasunori; Watabe, Tadashi; Isohashi, Kayako; Hatazawa, Jun; Tomiyama, Noriyuki

2017-10-01

This study aimed to compare the tumor volume definition using conventional magnetic resonance (MR) and 11C-methionine positron emission tomography (MET/PET) images in the differentiation of the pre-operative glioma grade by using whole-tumor histogram analysis of normalized cerebral blood volume (nCBV) maps. Thirty-four patients with histopathologically proven primary brain low-grade gliomas (n = 15) and high-grade gliomas (n = 19) underwent pre-operative or pre-biopsy MET/PET, fluid-attenuated inversion recovery, dynamic susceptibility contrast perfusion-weighted magnetic resonance imaging, and contrast-enhanced T1-weighted at 3.0 T. The histogram distribution derived from the nCBV maps was obtained by co-registering the whole tumor volume delineated on conventional MR or MET/PET images, and eight histogram parameters were assessed. The mean nCBV value had the highest AUC value (0.906) based on MET/PET images. Diagnostic accuracy significantly improved when the tumor volume was measured from MET/PET images compared with conventional MR images for the parameters of mean, 50th, and 75th percentile nCBV value (p = 0.0246, 0.0223, and 0.0150, respectively). Whole-tumor histogram analysis of CBV map provides more valuable histogram parameters and increases diagnostic accuracy in the differentiation of pre-operative cerebral gliomas when the tumor volume is derived from MET/PET images.

Specification of volume and dose in radiotherapy

International Nuclear Information System (INIS)

Levernes, S.

1997-01-01

As a result of a questionnaire about dose and volume specifications in radiotherapy in the Nordic countries, a group has been set up to propose common recommendations for these countries. The proposal is partly based on ICRU 50, but with major extensions. These extensions fall into three areas: patient geometry, treatment geometry, and dose specifications. For patient geometry and set-up one need alignment markings and anatomical reference points, the latter can be divided into internal and external reference points. These points are necessary to get relationships between coordinate systems related to patient and to treatment unit. For treatment geometry the main volume will be an anatomical target volume which just encompass the clinical target volume with all its variations and movements. This anatomical volume are the most suitable volume for prescription, optimization and reporting dose. A set-up margin should be added to the beam periphery in beams-eye-view to get the minimum size and shape of the beam. For dose specification the most important parameter for homogeneous dose distributions is the arithmetic mean of dose to the anatomical target volume together with its standard deviation. In addition the dose to the ICRU reference point should be reported for intercomparison, together with minimum and maximum doses or dose volume histograms for the anatomical target volume. (author)

Reduction of heart volume during neoadjuvant chemoradiation in patients with resectable esophageal cancer

International Nuclear Information System (INIS)

Haj Mohammad, Nadia; Kamphuis, Martijn; Hulshof, Maarten C.C.M.; Lutkenhaus, Lotte J.; Gisbertz, Suzanne S.; Bergman, Jacques J.G.H.M.; Bruin-Bon, H.A.C.M. Rianne de; Geijsen, Elisabeth D.; Bel, Arjan; Boekholdt, S. Mathijs; Laarhoven, Hanneke W.M. van

2015-01-01

Background and purpose: Neoadjuvant chemoradiation (nCRT) followed by surgery is considered curative intent treatment for patients with resectable esophageal cancer. The aim was to establish hemodynamic aspects of changes in heart volume and to explore whether changes in heart volume resulted in clinically relevant changes in the dose distribution of radiotherapy. Methods: A prospective study was conducted in patients who were treated with nCRT consisting of carboplatin and paclitaxel concomitant with radiotherapy (41.4 Gy/1.8 Gy per fraction). Physical parameters, cardiac volume on CT and Cone beam CT, cardiac blood markers and cardiac ultrasound were obtained. Results: In 23 patients a significant decrease of 55.3 ml in heart volume was detected (95% CI 36.7–73.8 ml, p < 0.001). There was a decrease in both systolic (mean decrease 18 mmHg, 95% CI 11–26 mmHg, p < 0.001) and diastolic blood pressure (mean decrease 8 mmHg, 95% CI 2–14 mmHg, p = 0.008) and an increase in heart rate with 6 beats/min (95% CI 1–11 beats/min, p = 0.021). Except for Troponin T, no change in other cardiac markers and echocardiography parameters were observed. The change in heart volume did not result in a clinically relevant change in radiation dose distribution. Conclusion: Heart volume was significantly reduced, but was not accompanied by overt cardiac dysfunction. All observed changes in hemodynamic parameters are consistent with volume depletion. Adaptation of the treatment plan during the course of radiotherapy is not advocated

Compact and intense parametric x-ray radiation source based on a linear accelerator with cryogenic accelerating and decelerating copper structures

Science.gov (United States)

Hyun, J.; Satoh, M.; Yoshida, M.; Sakai, T.; Hayakawa, Y.; Tanaka, T.; Hayakawa, K.; Sato, I.; Endo, K.

2018-01-01

This paper describes a proposal for a compact x-ray source based on parametric x-ray radiation (PXR). The PXR, which is produced when a single crystal is bombarded with relativistic electrons, has good monochromaticity and spatial coherence, and is expected to be well suited for imaging of low-Z materials and medical application. The proposed system employs a pair of copper accelerating structures which are operated at a cryogenic temperature of 20 K and arranged to form a resonant ring configuration. The electron beam is once accelerated up to 75 MeV in one of the structures, being decelerated down to lower than 7 MeV in the other structure after generating PXR at a single crystal, and then dumped. The expected x-ray yield is 1 09 photons /s at a center energy of 15 keV or higher.

MDCT quantification is the dominant parameter in decision–making regarding chest tube drainage for stable patients with traumatic pneumothorax

Science.gov (United States)

Cai, Wenli; Lee, June-Goo; Fikry, Karim; Yoshida, Hiroyuki; Novelline, Robert; de Moya, Marc

2013-01-01

It is commonly believed that the size of a pneumothorax is an important determinant of treatment decision, in particular regarding whether chest tube drainage (CTD) is required. However, the volumetric quantification of pneumothoraces has not routinely been performed in clinics. In this paper, we introduced an automated computer-aided volumetry (CAV) scheme for quantification of volume of pneumothoraces in chest multi-detect CT (MDCT) images. Moreover, we investigated the impact of accurate volume of pneumothoraces in the improvement of the performance in decision-making regarding CTD in the management of traumatic pneumothoraces. For this purpose, an occurrence frequency map was calculated for quantitative analysis of the importance of each clinical parameter in the decision-making regarding CTD by a computer simulation of decision-making using a genetic algorithm (GA) and a support vector machine (SVM). A total of 14 clinical parameters, including volume of pneumothorax calculated by our CAV scheme, was collected as parameters available for decision-making. The results showed that volume was the dominant parameter in decision-making regarding CTD, with an occurrence frequency value of 1.00. The results also indicated that the inclusion of volume provided the best performance that was statistically significant compared to the other tests in which volume was excluded from the clinical parameters. This study provides the scientific evidence for the application of CAV scheme in MDCT volumetric quantification of pneumothoraces in the management of clinically stable chest trauma patients with traumatic pneumothorax. PMID:22560899

Free volume model: High-temperature deformation of a Zr-based bulk metallic glass

International Nuclear Information System (INIS)

Bletry, M.; Guyot, P.; Blandin, J.J.; Soubeyroux, J.L.

2006-01-01

The homogeneous deformation of a zirconium-based bulk metallic glass is investigated in the glass transition region. Compression tests at different temperatures and strain rates have been conducted. The mechanical behavior is analyzed in the framework of the free volume model, taking into account the dependence of the flow defect concentration on deformation. The activation volume is evaluated and allows one to gather the viscosity data (for the different strain rates and temperatures) on a unique master curve. It is also shown that, due to the relation between flow defect concentration and free volume, it is not possible to deduce the equilibrium flow defect concentration directly from mechanical measurements. However, if this parameter is arbitrarily chosen, mechanical measurements give access to the other parameters of the model, these parameters for the alloy under investigation being of the same order of magnitude as those for other metallic glasses

Structure-volume relationships: singular volume effects produced by cupric ion-globular protein interaction.

Science.gov (United States)

Katz, S; Shinaberry, G; Heck, E L; Squire, W

1980-08-05

The nature of the volume isotherms produced by the coordination of Cu(II) with ovalbumin and bovine serum albumin differs substantially from the adsorption isotherms produced by these systems. Whereas there was increased binding of Cu(II) associated with a pH increase from pH 5.3 to pH 7.4, the volume isotherms for these systems did not exhibit this type of pH dependence. The volume changes were determined at 30.0 +/- 0.001 degrees C with microdilatometers which could be read to 0.01 muL. The binding isotherms for ovalbumin at pH 5.3 and 7.4 and for bovine serum albumin at pH 5.3 was resolved by a Scatchard plot to yield the appropriate thermodynamic parameters. An algorithm was derived to calculate the distribution of the individual PMi complexes, i.e., PMi-1 + M in equilibrium (Ki) PMi where i equals 1, 2, 3, ..., n moles of cation, M, bound per mole of protein, P, for the above systems. The volume isotherms were then resolved in terms of the constituent delta Vi terms, i.e., the volume change produced by the formation of the individual PMi complexes. These values were verified by an independent graphical differentiation procedure. The coordination of Cu(II) to BSA at pH 7.4 produced a cooperative adsorption isotherm which was not amenable to a Scatchard analysis. The resultant anomalous volume isotherm was resolved into a component related to Cu(II)-site interaction and a negative volume effect attributable to a conformational change induced by complex formation. This structural transition which occurs at physiological pH may constitute a control mechanism for regulating the serum level of Cu(II) and possibly other divalent ions.

Guiding automated left ventricular chamber segmentation in cardiac imaging using the concept of conserved myocardial volume.

Science.gov (United States)

Garson, Christopher D; Li, Bing; Acton, Scott T; Hossack, John A

2008-06-01

The active surface technique using gradient vector flow allows semi-automated segmentation of ventricular borders. The accuracy of the algorithm depends on the optimal selection of several key parameters. We investigated the use of conservation of myocardial volume for quantitative assessment of each of these parameters using synthetic and in vivo data. We predicted that for a given set of model parameters, strong conservation of volume would correlate with accurate segmentation. The metric was most useful when applied to the gradient vector field weighting and temporal step-size parameters, but less effective in guiding an optimal choice of the active surface tension and rigidity parameters.

Wheeled vehicle deceleration as estimation parameter of adaptive brake control system state

Directory of Open Access Journals (Sweden)

Turenko A.

2012-06-01

Full Text Available The method of stability estimation of adaptive control system with signal adjustment based on Lyapunov’s direct method that allows to take into account the nonstationarity of the basic system and non-linearity in the form of limitation on control action restriction as well as error control is stated.

The prognostic value of baseline 18F-FDG PET/CT in steroid-naive large-vessel vasculitis: introduction of volume-based parameters

International Nuclear Information System (INIS)

Dellavedova, L.; Carletto, M.; Maffioli, L.S.; Faggioli, P.; Sciascera, A.; Mazzone, A.; Del Sole, A.

2016-01-01

The aim of this study was to analyse if the result of a baseline 18 F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT scan, in large-vessel vasculitis (LVV) patients, is able to predict the course of the disease, not only in terms of presence/absence of final complications but also in terms of favourable/complicated progress (response to steroid therapy, time to steroid suspension, relapses, etc.). A total of 46 consecutive patients, who underwent 18 F-FDG PET/CT between May 2010 and March 2013 for fever of unknown origin (FUO) or suspected vasculitis (before starting corticosteroid therapy), were enrolled. The diagnosis of LVV was confirmed in 17 patients. Considering follow-up results, positive LVV patients were divided into two groups, one characterized by favourable (nine) and the other by complicated progress (eight), on the basis of presence/absence of vascular complications, presence/absence of at least another positive PET/CT during follow-up and impossibility to comply with the tapering schedule of the steroid due to biochemical/symptomatic relapse. Vessel uptake in subjects of the two groups was compared in terms of intensity and extension. To evaluate the extent of active disease, we introduced two volume-based parameters: ''volume of increased uptake'' (VIU) and ''total lesion glycolysis'' (TLG). The threshold used to calculate VIU on vessel walls was obtained by the ''vessel to liver'' ratio by means of receiver-operating characteristic analysis and was set at 0.92 x liver maximum standardized uptake value in each patient. Measures of tracer uptake intensity were significantly higher in patients with complicated progress compared to those with a favourable one (p < 0.05). Measures of disease extension were even more significant and TLG emerged as the best parameter to separate the two groups of patients (p = 0.01). This pilot study shows that, in LVV patients, the combined

Volume fractions of DCE-MRI parameter as early predictor of histologic response in soft tissue sarcoma: A feasibility study.

Science.gov (United States)

Xia, Wei; Yan, Zhuangzhi; Gao, Xin

2017-10-01

To find early predictors of histologic response in soft tissue sarcoma through volume transfer constant (K trans ) analysis based on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). 11 Patients with soft tissue sarcoma of the lower extremity that underwent preoperative chemoradiotherapy followed by limb salvage surgery were included in this retrospective study. For each patient, DCE-MRI data sets were collected before and two weeks after therapy initiation, and histologic tumor cell necrosis rate (TCNR) was reported at surgery. The DCE-MRI volumes were aligned by registration. Then, the aligned volumes were used to obtain the K trans variation map. Accordingly, three sub-volumes (with increased, decreased or unchanged K trans ) were defined and identified, and fractions of the sub-volumes, denoted as F + , F - and F 0 , respectively, were calculated. The predictive ability of volume fractions was determined by using area under a receiver operating characteristic curve (AUC). Linear regression analysis was performed to investigate the relationship between TCNR and volume fractions. In addition, the K trans values of the sub-volumes were compared. The AUC for F - (0.896) and F 0 (0.833) were larger than that for change of tumor longest diameter ΔD (0.625) and the change of mean K trans ΔK trans ¯ (0.792). Moreover, the regression results indicated that TCNR was directly proportional to F 0 (R 2 =0.75, P=0.0003), while it was inversely proportional to F - (R 2 =0.77, P=0.0002). However, TCNR had relatively weak linear relationship with ΔK trans ¯ (R 2 =0.64, P=0.0018). Additionally, TCNR did not have linear relationship with DD (R 2 =0.16, P=0.1246). The volume fraction F - and F 0 have potential as early predictors of soft tissue sarcoma histologic response. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparison of polyp size and volume at CT colonography: implications for follow-up CT colonography.

Science.gov (United States)

Bethea, Emily; Nwawka, Ogonna K; Dachman, Abraham H

2009-12-01

The purpose of this study was to evaluate the reliability of polyp measurements at CT colonography and the factors that affect the measurements. Fifty colonoscopically proven cases of polyps 6 mm in diameter or larger were analyzed by two observers who measured each polyp in supine and prone views. Manual measurements of 2D volume by summation of areas, 2D maximum diameter, and 3D maximum diameter and automated measurements of 3D maximum diameter and volume were recorded for each observer and were repeated for one of the observers. Intraobserver and interobserver agreement was calculated. Analysis was performed to determine the measurement parameter that correlated most with summation-of-areas volume. Supine and prone measurements as a surrogate for tracking change in polyp size over time were analyzed to determine the measurement parameter with the least variation. Maximum diameter measured manually on 3D images had the highest correlation with summation-of-areas volume. Manual summation-of-areas volume was found to have the least variation between supine and prone measurements. Linear polyp measurement in the 3D endoluminal view appears to be the most reliable parameter for use in the decision to excise a polyp according to current guidelines. In our study, manual calculation of volume with summation of areas was found to be the most reliable measurement parameter for observing polyp growth over serial examinations. High reliability of polyp measurements is essential for adequate assessment of change in polyp size over serial examinations because many patients with intermediate-size polyps are expected to choose surveillance.

Unifying inflation with late-time acceleration by a BIonic system

Energy Technology Data Exchange (ETDEWEB)

Sepehri, Alireza, E-mail: alireza.sepehri@uk.ac.ir [Faculty of Physics, Shahid Bahonar University, P.O. Box 76175, Kerman (Iran, Islamic Republic of); Rahaman, Farook, E-mail: rahaman@iucaa.ernet.in [Department of Mathematics, Jadavpur University, Kolkata 700032, West Bengal (India); Setare, Mohammad Reza, E-mail: rezakord@ipm.ir [Department of Science, Campus of Bijar, University of Kurdistan, Bijar (Iran, Islamic Republic of); Pradhan, Anirudh, E-mail: pradhan@iucaa.ernet.in [Department of Mathematics, Institute of Applied Sciences & Humanities, GLA University, Mathura-281 406, U.P. (India); Capozziello, Salvatore, E-mail: capozziello@na.infn.it [Dipartimento di Fisica, Universitá di Napoli “Federico II”, I-80126 Napoli (Italy); INFN Sezione di Napoli, Complesso Universitario di Monte S. Angelo, Edificio G, I-80126 Napoli (Italy); Gran Sasso Science Institute (INFN), Viale F. Crispi, 7, I-67100 L' Aquila (Italy); Sardar, Iftikar Hossain, E-mail: iftikar.spm@gmail.com [Department of Mathematics, Jadavpur University, Kolkata 700032, West Bengal (India)

2015-07-30

We propose a cosmological model that unifies inflation, deceleration and acceleration phases of expansion history by a BIonic system. At the beginning, there are k black fundamental strings that transited to the BIon configuration at a given corresponding point. Here, two coupled universes, brane and antibrane, are created interacting each other through a wormhole and inflate. With decreasing temperature, the energy of this wormhole flows into the universe branes and leads to inflation. After a short time, the wormhole evaporates, the inflation ends and a deceleration epoch starts. By approaching the brane and antibrane universes together, a tachyon is born, grows and causes the creation of a new wormhole. At this time, the brane and antibrane universes result connected again and the late-time acceleration era of the universe begins. We compare our model with previous unified phantom models and observational data obtaining some cosmological parameters like temperature in terms of time. We also find that deceleration parameter is negative during inflation and late-time acceleration epochs, while it is positive during the deceleration era. This means that the model is consistent, in principle, with cosmological observations.

Unifying inflation with late-time acceleration by a BIonic system

Directory of Open Access Journals (Sweden)

Alireza Sepehri

2015-07-01

Full Text Available We propose a cosmological model that unifies inflation, deceleration and acceleration phases of expansion history by a BIonic system. At the beginning, there are k black fundamental strings that transited to the BIon configuration at a given corresponding point. Here, two coupled universes, brane and antibrane, are created interacting each other through a wormhole and inflate. With decreasing temperature, the energy of this wormhole flows into the universe branes and leads to inflation. After a short time, the wormhole evaporates, the inflation ends and a deceleration epoch starts. By approaching the brane and antibrane universes together, a tachyon is born, grows and causes the creation of a new wormhole. At this time, the brane and antibrane universes result connected again and the late-time acceleration era of the universe begins. We compare our model with previous unified phantom models and observational data obtaining some cosmological parameters like temperature in terms of time. We also find that deceleration parameter is negative during inflation and late-time acceleration epochs, while it is positive during the deceleration era. This means that the model is consistent, in principle, with cosmological observations.

Unifying inflation with late-time acceleration by a BIonic system

International Nuclear Information System (INIS)

Sepehri, Alireza; Rahaman, Farook; Setare, Mohammad Reza; Pradhan, Anirudh; Capozziello, Salvatore; Sardar, Iftikar Hossain

2015-01-01

We propose a cosmological model that unifies inflation, deceleration and acceleration phases of expansion history by a BIonic system. At the beginning, there are k black fundamental strings that transited to the BIon configuration at a given corresponding point. Here, two coupled universes, brane and antibrane, are created interacting each other through a wormhole and inflate. With decreasing temperature, the energy of this wormhole flows into the universe branes and leads to inflation. After a short time, the wormhole evaporates, the inflation ends and a deceleration epoch starts. By approaching the brane and antibrane universes together, a tachyon is born, grows and causes the creation of a new wormhole. At this time, the brane and antibrane universes result connected again and the late-time acceleration era of the universe begins. We compare our model with previous unified phantom models and observational data obtaining some cosmological parameters like temperature in terms of time. We also find that deceleration parameter is negative during inflation and late-time acceleration epochs, while it is positive during the deceleration era. This means that the model is consistent, in principle, with cosmological observations

Computer-assisted lung nodule volumetry from multi-detector row CT: Influence of image reconstruction parameters

International Nuclear Information System (INIS)

Honda, Osamu; Sumikawa, Hiromitsu; Johkoh, Takeshi; Tomiyama, Noriyuki; Mihara, Naoki; Inoue, Atsuo; Tsubamoto, Mitsuko; Natsag, Javzandulam; Hamada, Seiki; Nakamura, Hironobu

2007-01-01

Purpose: To investigate differences in volumetric measurement of pulmonary nodules caused by changing the reconstruction parameters for multi-detector row CT. Materials and methods: Thirty-nine pulmonary nodules less than 2 cm in diameter were examined by multi-slice CT. All nodules were solid, and located in the peripheral part of the lungs. The resultant 48 parameters images were reconstructed by changing slice thickness (1.25, 2.5, 3.75, or 5 mm), field of view (FOV: 10, 20, or 30 cm), algorithm (high-spatial frequency algorithm or low-spatial frequency algorithm) and reconstruction interval (reconstruction with 50% overlapping of the reconstructed slices or non-overlapping reconstruction). Volumetric measurements were calculated using commercially available software. The differences between nodule volumes were analyzed by the Kruskal-Wallis test and the Wilcoxon Signed-Ranks test. Results: The diameter of the nodules was 8.7 ± 2.7 mm on average, ranging from 4.3 to 16.4 mm. Pulmonary nodule volume did not change significantly with changes in slice thickness or FOV (p > 0.05), but was significantly larger with the high-spatial frequency algorithm than the low-spatial frequency algorithm (p < 0.05), except for one reconstruction parameter. The volumes determined by non-overlapping reconstruction were significantly larger than those of overlapping reconstruction (p < 0.05), except for a 1.25 mm thickness with 10 cm FOV with the high-spatial frequency algorithm, and 5 mm thickness. The maximum difference in measured volume was 16% on average between the 1.25 mm slice thickness/10 cm FOV/high-spatial frequency algorithm parameters and overlapping reconstruction. Conclusion: Volumetric measurements of pulmonary nodules differ with changes in the reconstruction parameters, with a tendency toward larger volumes in high-spatial frequency algorithm and non-overlapping reconstruction compared to the low-spatial frequency algorithm and overlapping reconstruction

The Dose-Volume Relationship of Small Bowel Irradiation and Acute Grade 3 Diarrhea During Chemoradiotherapy for Rectal Cancer

International Nuclear Information System (INIS)

Robertson, John M.; Lockman, David; Yan Di; Wallace, Michelle

2008-01-01

Purpose: Previous work has found a highly significant relationship between the irradiated small-bowel volume and development of Grade 3 small-bowel toxicity in patients with rectal cancer. This study tested the previously defined parameters in a much larger group of patients. Methods and Materials: A total of 96 consecutive patients receiving pelvic radiation therapy for rectal cancer had treatment planning computed tomographic scans with small-bowel contrast that allowed the small bowel to be outlined with calculation of a small-bowel dose-volume histogram for the initial intended pelvic treatment to 45 Gy. Patients with at least one parameter above the previously determined dose-volume parameters were considered high risk, whereas those with all parameters below these levels were low risk. The grade of diarrhea and presence of liquid stool was determined prospectively. Results: There was a highly significant association with small-bowel dose-volume and Grade 3 diarrhea (p ≤ 0.008). The high-risk and low-risk parameters were predictive with Grade 3 diarrhea in 16 of 51 high-risk patients and in 4 of 45 low-risk patients (p = 0.01). Patients who had undergone irradiation preoperatively had a lower incidence of Grade 3 diarrhea than those treated postoperatively (18% vs. 28%; p = 0.31); however, the predictive ability of the high-risk/low-risk parameters was better for preoperatively (p = 0.03) than for postoperatively treated patients (p = 0.15). Revised risk parameters were derived that improved the overall predictive ability (p = 0.004). Conclusions: The highly significant dose-volume relationship and validity of the high-risk and low-risk parameters were confirmed in a large group of patients. The risk parameters provided better modeling for the preoperative patients than for the postoperative patients

Geometrical considerations in dose volume analysis in intracavitary treatment

International Nuclear Information System (INIS)

Deshpande, D.D.; Shrivastava, S.K.; Pradhan, A.S.; Viswanathan, P.S.; Dinshaw, K.A.

1996-01-01

The present work was aimed at to study the relationship between the volume enclosed by reference iodose surface and various geometrical parameters of the intracavitary applicator in treatment of carcinoma of cervix. Pearshape volume of the reference isodose derived from the Total Reference Air Kerma (TRAK) and the product of its dimensions, height H, width W and thickness T which is dependent on the applicator geometry, were estimated for 100 intracavitary applications treated by Selectron LDR machine. Orthogonal radiographs taken for each patient were used for measurement of actual geometric dimensions of the applicator and carrying out the dosimetry on TP-11 treatment planning system. The dimensions H, W and T of reference isodose surface (60 Gy) were also noted. Ratio of the product HWT and the pearshape volume was found mainly to be a function of colpostat separation and not of other geometrical parameters like maximum vertical and anterio-posterior dimension of the applicator. The ratio remained almost constant for a particular combination of uterine tandem and colpostat. Variation in the ratios were attributed to the non-standard geometry. The ratio of the volume of reference isodose surface to the product of its dimensions in the applicator depends upon the colpostat separation. (orig./MG) [de

ANDRA - Referential Materials. Volume 1: Context and scope; Volume 2: Argillaceous materials; Volume 3: Cementitious materials; Volume 4: The corrosion of metallic materials

International Nuclear Information System (INIS)

2001-01-01

This huge document gathers four volumes. The first volume presents some generalities about materials used in the storage of radioactive materials (definition, design principle, current choices and corresponding storage components, general properties of materials and functions of the corresponding storage components, physical and chemical solicitations experienced by materials in a storage), and the structure and content of the other documents. The second volume addresses argillaceous materials. It presents some generalities about these materials in the context of a deep geological storage, and about their design. It presents and comments the crystalline and chemical, and physical and chemical characteristics of swelling argillaceous materials and minerals, describes how these swelling argillaceous materials are shaped and set up, presents and comments physical properties (hydraulic, mechanical and thermal properties) of these materials, comments and discusses the modelling of the geo-chemical behaviour, and their behaviour in terms of containment and transport of radionuclides. The third volume addresses cementitious materials. It presents some generalities about these materials in the context of a deep geological storage, and about their definition and specifications. It presents some more detailed generalities (cement definition and composition, hydration, microstructure of hydrated cements, adjuvants), presents and comments their physical properties (fresh concrete structure and influence of composition, main aimed properties in the hardened status, transfer, mechanical, and thermal properties, shaping and setting up of these materials, technical solutions for hydraulic works). The fourth volume addresses the corrosion of metallic materials. It presents some generalities about these materials in the context of a deep geological storage of radioactive materials. It presents metallic materials and discusses their corrosion behaviour. It describes the peculiarities

A deceleration search for magnetar pulsations in the X-ray plateaus of short GRBs

Science.gov (United States)

Rowlinson, A.; Patruno, A.; O'Brien, P. T.

2017-11-01

A newly formed magnetar has been proposed as the central engine of short GRBs to explain ongoing energy injection giving observed plateau phases in the X-ray light curves. These rapidly spinning magnetars may be capable of emitting pulsed emission comparable to known pulsars and magnetars. In this paper we show that, if present, a periodic signal would be detectable during the plateau phases observed using the Swift/X-Ray Telescope recording data in Window Timing mode. We conduct a targeted deceleration search for a periodic signal from a newly formed magnetar in 2 Swift short GRBs and rule out any periodic signals in the frequency band 10-285 Hz to ≈15-30 per cent rms. These results demonstrate that we would be able to detect pulsations from the magnetar central engine of short GRBs if they contribute to 15-30 per cent of the total emission. We consider these constraints in the context of the potential emission mechanisms. The non-detection is consistent with the emission being reprocessed in the surrounding environment or with the rotation axis being highly aligned with the observing angle. As the emission may be reprocessed, the expected periodic emission may only constitute a few per cent of the total emission and be undetectable in our observations. Applying this strategy to future observations of the plateau phases with more sensitive X-ray telescopes may lead to the detection of the periodic signal.

MDCT quantification is the dominant parameter in decision-making regarding chest tube drainage for stable patients with traumatic pneumothorax.

Science.gov (United States)

Cai, Wenli; Lee, June-Goo; Fikry, Karim; Yoshida, Hiroyuki; Novelline, Robert; de Moya, Marc

2012-07-01

It is commonly believed that the size of a pneumothorax is an important determinant of treatment decision, in particular regarding whether chest tube drainage (CTD) is required. However, the volumetric quantification of pneumothoraces has not routinely been performed in clinics. In this paper, we introduced an automated computer-aided volumetry (CAV) scheme for quantification of volume of pneumothoraces in chest multi-detect CT (MDCT) images. Moreover, we investigated the impact of accurate volume of pneumothoraces in the improvement of the performance in decision-making regarding CTD in the management of traumatic pneumothoraces. For this purpose, an occurrence frequency map was calculated for quantitative analysis of the importance of each clinical parameter in the decision-making regarding CTD by a computer simulation of decision-making using a genetic algorithm (GA) and a support vector machine (SVM). A total of 14 clinical parameters, including volume of pneumothorax calculated by our CAV scheme, was collected as parameters available for decision-making. The results showed that volume was the dominant parameter in decision-making regarding CTD, with an occurrence frequency value of 1.00. The results also indicated that the inclusion of volume provided the best performance that was statistically significant compared to the other tests in which volume was excluded from the clinical parameters. This study provides the scientific evidence for the application of CAV scheme in MDCT volumetric quantification of pneumothoraces in the management of clinically stable chest trauma patients with traumatic pneumothorax. Copyright © 2012 Elsevier Ltd. All rights reserved.

Volume reduction, a safer and cheaper way of radwaste management

International Nuclear Information System (INIS)

Mergan, L.M.; Cordier, J.P.; Storrer, J.A.

1979-01-01

Development of 'Volume Reduction' has demonstrated that it is a safer and cheaper radwaste management method. Safer, because of several advantages: decrease of solidified product volume, satisfactory product properties, absence of free water, better control of process parameters, increased encapsulation efficiency ... The corresponding impact on the waste management costs, results in important savings on different factors, as well as regards the operational costs as the investment expenses. Economy in the range of BF 35.000 per m 3 of incoming waste is achievable. The main volume reduction techniques readily available are briefly reviewed

Design flood hydrographs from the relationship between flood peak and volume

Directory of Open Access Journals (Sweden)

L. Mediero

2010-12-01

Full Text Available Hydrological frequency analyses are usually focused on flood peaks. Flood volumes and durations have not been studied as extensively, although there are many practical situations, such as when designing a dam, in which the full hydrograph is of interest. A flood hydrograph may be described by a multivariate function of the peak, volume and duration. Most standard bivariate and trivariate functions do not produce univariate three-parameter functions as marginal distributions, however, three-parameter functions are required to fit highly skewed data, such as flood peak and flood volume series. In this paper, the relationship between flood peak and hydrograph volume is analysed to overcome this problem. A Monte Carlo experiment was conducted to generate an ensemble of hydrographs that maintain the statistical properties of marginal distributions of the peaks, volumes and durations. This ensemble can be applied to determine the Design Flood Hydrograph (DFH for a reservoir, which is not a unique hydrograph, but rather a curve in the peak-volume space. All hydrographs on that curve have the same return period, which can be understood as the inverse of the probability to exceed a certain water level in the reservoir in any given year. The procedure can also be applied to design the length of the spillway crest in terms of the risk of exceeding a given water level in the reservoir.

Thermal expansion and lattice parameters of shaped metal deposited Ti-6Al-4V

Energy Technology Data Exchange (ETDEWEB)

Swarnakar, Akhilesh Kumar; Van der Biest, Omer [Katholieke Universiteit Leuven, MTM, Kasteelpark Arenberg 44, 3001 Leuven (Belgium); Baufeld, Bernd, E-mail: b.baufeld@sheffield.ac.uk [Katholieke Universiteit Leuven, MTM, Kasteelpark Arenberg 44, 3001 Leuven (Belgium)

2011-02-10

Research highlights: > Measurement of thermal expansion and of the lattice parameters of Ti-6Al-4V fabricated by shaped metal deposition up to 1100 {sup o}C. > The observation of alpha to beta transformation not reflected in the expansion but in the contraction curve is explained by non-equilibrium alpha phase of the SMD material. > Denuding of the {alpha} phase and enrichment of the {beta} phase of Vanadium due to high temperature experiments. > The unit cell volumes derived from lattice parameters measured by X-ray diffraction are at room temperature larger for the {alpha} than for the {beta} phase. With increasing temperature the unit cell volume of the {beta} phase increases stronger than the one of the {alpha} phase resulting in a similar unit cell volume at the {beta} transus temperature. - Abstract: Thermal expansion and lattice parameters are investigated up to 1100 deg. C for Ti-6Al-4V components, fabricated by shaped metal deposition. This is a novel additive layer manufacturing technique where near net-shape components are built by tungsten inert gas welding. The as-fabricated SMD Ti-6Al-4V components exhibit a constant coefficient of thermal expansion of 1.17 x 10{sup -5} K{sup -1} during heating up to 1100 {sup o}C, not reflecting the {alpha} to {beta} phase transformation. During cooling a stalling of the contraction is observed starting at the {beta} transus temperature. These high temperature experiments denude the {alpha} phase of V and enrich the {beta} phase. The development of the lattice parameters in dependence on temperature are observed with high temperature X-ray diffraction. The unit cell volumes derived from these parameters are at room temperature larger for the {alpha} than for the {beta} phase. With increasing temperature the unit cell volume of the {beta} phase increases stronger than the one of the {alpha} phase resulting in a similar unit cell volume at the {beta} transus temperature. These observations are interpreted as an

Development and testing of a three-stage double tandem accelerator-decelerator system for low energy, highly stripped ions. Progress report, March 1, 1978--February 28, 1979

International Nuclear Information System (INIS)

Bayfield, J.E.

1978-11-01

Three-stage operation of the University of Pittsburgh accel-decel double tandem source of highly stripped ion beams is described. The system has produced 0 5+ , 0 6+ , 0 7+ , and 0 8+ ions at specific energies as low as 15 keV per AMU. The design of the new decelerator tubes is discussed. The present performance and limitations of the overall system are outlined. Some new charge exchange cross sections have been measured, for combined higher ion charge states and lower ion energies than heretofore was possible. Future four-stage operation with very heavy ions is considered

Some necessary parameters for a critical velocity interaction between the ionospheric plasma and a xenon cloud

International Nuclear Information System (INIS)

Axnaes, I.

1979-12-01

The conditions for an experiment to study the critical ionization velocity effect in the interaction between a Xenon cloud, released from a satellite, and the ionospheric plasma are investigated. The model used is based on the assumption that there exists an effective process that transfers the energy, that is available in the relative motion, to the electrons. Some necessary conditions to obtain significant heating or deceleration of the plasma penetrating the cloud are calculated. The conditions are mainly given by the energy available in the relative motion and the rates of the different binary collision processes involved. As the released gas cloud expands the possibilities for a critical velocity interaction will exist only within a certain range of cloud radii. It is shown that the charge transfer collision cross section between the ionospheric ions and the cloud atoms is an important parameter and that Xenon is a very suitable gas in that respect. (author)

Infrared Drying Parameter Optimization

Science.gov (United States)

Jackson, Matthew R.

In recent years, much research has been done to explore direct printing methods, such as screen and inkjet printing, as alternatives to the traditional lithographic process. The primary motivation is reduction of the material costs associated with producing common electronic devices. Much of this research has focused on developing inkjet or screen paste formulations that can be printed on a variety of substrates, and which have similar conductivity performance to the materials currently used in the manufacturing of circuit boards and other electronic devices. Very little research has been done to develop a process that would use direct printing methods to manufacture electronic devices in high volumes. This study focuses on developing and optimizing a drying process for conductive copper ink in a high volume manufacturing setting. Using an infrared (IR) dryer, it was determined that conductive copper prints could be dried in seconds or minutes as opposed to tens of minutes or hours that it would take with other drying devices, such as a vacuum oven. In addition, this study also identifies significant parameters that can affect the conductivity of IR dried prints. Using designed experiments and statistical analysis; the dryer parameters were optimized to produce the best conductivity performance for a specific ink formulation and substrate combination. It was determined that for an ethylene glycol, butanol, 1-methoxy 2- propanol ink formulation printed on Kapton, the optimal drying parameters consisted of a dryer height of 4 inches, a temperature setting between 190 - 200°C, and a dry time of 50-65 seconds depending on the printed film thickness as determined by the number of print passes. It is important to note that these parameters are optimized specifically for the ink formulation and substrate used in this study. There is still much research that needs to be done into optimizing the IR dryer for different ink substrate combinations, as well as developing a

Debye–Einstein approximation approach to calculate the lattice specific heat and related parameters for a Si nanowire

Directory of Open Access Journals (Sweden)

A. KH. Alassafee

2017-11-01

Full Text Available The modified Debye–Einstein approximation model is used to calculate nanoscale size-dependent values of Gruneisen parameters and lattice specific heat capacity for Si nanowires. All parameters forming the model, including Debye temperatures, bulk moduli, the lattice thermal expansion and the lattice volume, are calculated according to their nanoscale size dependence. Values for lattice volume Gruneisen parameters increase with the decrease of the nanowires’ diameter, while all other parameters decrease. The nanosize dependence of lattice thermal parameters agree with other reported theoretical results. Keywords: Lattice specific heat capacity, Gruneisen parameter, Debye–Einstein model, Si nanowires

Neuropsychology, autobiographical memory and hippocampal volume in younger and older patients with chronic schizophrenia

Directory of Open Access Journals (Sweden)

Christina Josefa Herold

2015-04-01

Full Text Available Despite a wide range of studies on neuropsychology in schizophrenia, autobiographical memory (AM has been scarcely investigated in these patients. Hence less is known about AM in older patients and hippocampal contribution to autobiographical memories of varying remoteness. Therefore we investigated hippocampal volume and AM along with important neuropsychological domains in patients with chronic schizophrenia and the respective relationships between these parameters. We compared 25 older patients with chronic schizophrenia to 23 younger patients and an older healthy control group (N = 21 with respect to AM, additional neuropsychological parameters and hippocampal volume. Personal episodic and semantic memory was investigated using a semi-structured interview. Additional neuropsychological parameters were assessed by using a battery of standard neuropsychological tests. Structural magnetic resonance imaging data were analysed with an automated region-of-interest procedure. While hippocampal volume reduction and neuropsychological impairment were more pronounced in the older than in the younger patients, both groups showed equivalent reduced AM performance for recent personal episodes. In the patient group significant correlations between left hippocampal volume and recent autobiographical episodes as well as personal semantic memories arose. Verbal memory and working memory were significantly correlated with right hippocampal volume, executive functions, however, were associated with bilateral hippocampal volumes. These findings underline the complexity of AM and its impairments in the course of schizophrenia in comparison to rather progressive neuropsychological deficits and address the importance of hippocampal contribution.

Neuropsychology, autobiographical memory, and hippocampal volume in "younger" and "older" patients with chronic schizophrenia.

Science.gov (United States)

Herold, Christina Josefa; Lässer, Marc Montgomery; Schmid, Lena Anna; Seidl, Ulrich; Kong, Li; Fellhauer, Iven; Thomann, Philipp Arthur; Essig, Marco; Schröder, Johannes

2015-01-01

Despite a wide range of studies on neuropsychology in schizophrenia, autobiographical memory (AM) has been scarcely investigated in these patients. Hence, less is known about AM in older patients and hippocampal contribution to autobiographical memories of varying remoteness. Therefore, we investigated hippocampal volume and AM along with important neuropsychological domains in patients with chronic schizophrenia and the respective relationships between these parameters. We compared 25 older patients with chronic schizophrenia to 23 younger patients and an older healthy control group (N = 21) with respect to AM, additional neuropsychological parameters, and hippocampal volume. Personal episodic and semantic memory was investigated using a semi-structured interview. Additional neuropsychological parameters were assessed by using a battery of standard neuropsychological tests. Structural magnetic resonance imaging data were analyzed with an automated region-of-interest procedure. While hippocampal volume reduction and neuropsychological impairment were more pronounced in the older than in the younger patients, both groups showed equivalent reduced AM performance for recent personal episodes. In the patient group, significant correlations between left hippocampal volume and recent autobiographical episodes as well as personal semantic memories arose. Verbal memory and working memory were significantly correlated with right hippocampal volume; executive functions, however, were associated with bilateral hippocampal volumes. These findings underline the complexity of AM and its impairments in the course of schizophrenia in comparison to rather progressive neuropsychological deficits and address the importance of hippocampal contribution.

A Curriculum Activities Guide to Water Pollution and Environmental Studies, Volume II - Appendices.

Science.gov (United States)

Hershey, John T., Ed.; And Others

This publication, Volume II of a two volume set of water pollution studies, contains seven appendices which support the studies. Appendix 1, Water Quality Parameters, consolidates the technical aspects of water quality including chemical, biological, computer program, and equipment information. Appendix 2, Implementation, outlines techniques…

Deceleration of High-velocity Interstellar Photon Sails into Bound Orbits at α Centauri

Energy Technology Data Exchange (ETDEWEB)

Heller, René [Max Planck Institute for Solar System Research Justus-von-Liebig-Weg 3, 37077 Göttingen (Germany); Hippke, Michael, E-mail: heller@mps.mpg.de, E-mail: hippke@ifda.eu [Luiter Straße 21b, 47506 Neukirchen-Vluyn (Germany)

2017-02-01

At a distance of about 4.22 ly, it would take about 100,000 years for humans to visit our closest stellar neighbor Proxima Centauri using modern chemical thrusters. New technologies are now being developed that involve high-power lasers firing at 1 gram solar sails in near-Earth orbits, accelerating them to 20% the speed of light ( c ) within minutes. Although such an interstellar probe could reach Proxima 20 years after launch, without propellant to slow it down it would traverse the system within hours. Here we demonstrate how the stellar photon pressures of the stellar triple α Cen A, B, and C (Proxima) can be used together with gravity assists to decelerate incoming solar sails from Earth. The maximum injection speed at α Cen A to park a sail with a mass-to-surface ratio ( σ ) similar to graphene (7.6 × 10{sup −4} gram m{sup −2}) in orbit around Proxima is about 13,800 km s{sup −1} (4.6% c ), implying travel times from Earth to α Cen A and B of about 95 years and another 46 years (with a residual velocity of 1280 km s{sup −1}) to Proxima. The size of such a low- σ sail required to carry a payload of 10 grams is about 10{sup 5} m{sup 2} = (316 m){sup 2}. Such a sail could use solar photons instead of an expensive laser system to gain interstellar velocities at departure. Photogravitational assists allow visits of three stellar systems and an Earth-sized potentially habitable planet in one shot, promising extremely high scientific yields.

Deceleration of High-velocity Interstellar Photon Sails into Bound Orbits at α Centauri

International Nuclear Information System (INIS)

Heller, René; Hippke, Michael

2017-01-01

At a distance of about 4.22 ly, it would take about 100,000 years for humans to visit our closest stellar neighbor Proxima Centauri using modern chemical thrusters. New technologies are now being developed that involve high-power lasers firing at 1 gram solar sails in near-Earth orbits, accelerating them to 20% the speed of light ( c ) within minutes. Although such an interstellar probe could reach Proxima 20 years after launch, without propellant to slow it down it would traverse the system within hours. Here we demonstrate how the stellar photon pressures of the stellar triple α Cen A, B, and C (Proxima) can be used together with gravity assists to decelerate incoming solar sails from Earth. The maximum injection speed at α Cen A to park a sail with a mass-to-surface ratio ( σ ) similar to graphene (7.6 × 10"−"4 gram m"−"2) in orbit around Proxima is about 13,800 km s"−"1 (4.6% c ), implying travel times from Earth to α Cen A and B of about 95 years and another 46 years (with a residual velocity of 1280 km s"−"1) to Proxima. The size of such a low- σ sail required to carry a payload of 10 grams is about 10"5 m"2 = (316 m)"2. Such a sail could use solar photons instead of an expensive laser system to gain interstellar velocities at departure. Photogravitational assists allow visits of three stellar systems and an Earth-sized potentially habitable planet in one shot, promising extremely high scientific yields.

The prognostic value of baseline {sup 18}F-FDG PET/CT in steroid-naive large-vessel vasculitis: introduction of volume-based parameters

Energy Technology Data Exchange (ETDEWEB)

Dellavedova, L. [Ospedale Civile di Legnano, PET/CT Center - Nuclear Medicine Department, Legnano (Italy); University of Milan, Department of Health Sciences, Milan (Italy); Carletto, M.; Maffioli, L.S. [Ospedale Civile di Legnano, PET/CT Center - Nuclear Medicine Department, Legnano (Italy); Faggioli, P.; Sciascera, A.; Mazzone, A. [Ospedale Civile di Legnano, Internal Medicine Department, Legnano (Italy); Del Sole, A. [University of Milan, Department of Health Sciences, Milan (Italy)

2016-02-15

The aim of this study was to analyse if the result of a baseline {sup 18}F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT scan, in large-vessel vasculitis (LVV) patients, is able to predict the course of the disease, not only in terms of presence/absence of final complications but also in terms of favourable/complicated progress (response to steroid therapy, time to steroid suspension, relapses, etc.). A total of 46 consecutive patients, who underwent {sup 18}F-FDG PET/CT between May 2010 and March 2013 for fever of unknown origin (FUO) or suspected vasculitis (before starting corticosteroid therapy), were enrolled. The diagnosis of LVV was confirmed in 17 patients. Considering follow-up results, positive LVV patients were divided into two groups, one characterized by favourable (nine) and the other by complicated progress (eight), on the basis of presence/absence of vascular complications, presence/absence of at least another positive PET/CT during follow-up and impossibility to comply with the tapering schedule of the steroid due to biochemical/symptomatic relapse. Vessel uptake in subjects of the two groups was compared in terms of intensity and extension. To evaluate the extent of active disease, we introduced two volume-based parameters: ''volume of increased uptake'' (VIU) and ''total lesion glycolysis'' (TLG). The threshold used to calculate VIU on vessel walls was obtained by the ''vessel to liver'' ratio by means of receiver-operating characteristic analysis and was set at 0.92 x liver maximum standardized uptake value in each patient. Measures of tracer uptake intensity were significantly higher in patients with complicated progress compared to those with a favourable one (p < 0.05). Measures of disease extension were even more significant and TLG emerged as the best parameter to separate the two groups of patients (p = 0.01). This pilot study shows that, in LVV patients, the

Fukushima Daiichi Unit 1 Uncertainty Analysis-Exploration of Core Melt Progression Uncertain Parameters-Volume II.

Energy Technology Data Exchange (ETDEWEB)

Denman, Matthew R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brooks, Dusty Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-08-01

Sandia National Laboratories (SNL) has conducted an uncertainty analysi s (UA) on the Fukushima Daiichi unit (1F1) accident progression wit h the MELCOR code. Volume I of the 1F1 UA discusses the physical modeling details and time history results of the UA. Volume II of the 1F1 UA discusses the statistical viewpoint. The model used was developed for a previous accident reconstruction investigation jointly sponsored by the US Department of Energy (DOE) and Nuclear Regulatory Commission (NRC). The goal of this work was to perform a focused evaluation of uncertainty in core damage progression behavior and its effect on key figures - of - merit (e.g., hydrogen production, fraction of intact fuel, vessel lower head failure) and in doing so assess the applicability of traditional sensitivity analysis techniques .

Estimation of soil properties and free product volume from baildown tests

International Nuclear Information System (INIS)

Zhu, J.L.; Parker, J.C.; Lundy, D.A.; Zimmerman, L.M.

1993-01-01

Baildown tests, involving measurement of water and free product levels in a monitoring well after bailing, are often performed at spill sites to estimate the oil volume per unit area -- which the authors refer to as ''oil specific volume.'' Spill volume is estimated by integrating oil specific volume over the areal domain of the spill. Existing methods for interpreting baildown tests are based on grossly simplistic approximations of soil capillary properties that cannot accurately describe the transient well response. A model for vertical equilibrium oil distributions based on the van Genuchten capillary model has been documented and verified in the laboratory and in the field by various authors. The model enables oil specific volume and oil transmissivity to be determined as functions of well product thickness. This paper describes a method for estimating van Genuchten capillary parameters, as well as aquifer hydraulic conductivity, from baildown tests. The results yield the relationships of oil specific volume and oil transmissivity to apparent product thickness, which may be used, in turn, to compute spill volume and to model free product plume movement and free product recovery. The method couples a finite element model for radial flow of oil and water to a well with a nonlinear parameter estimation algorithm. Effects of the filter pack around the well in the fluid level response are considered explicitly by the model. The method, which is implemented in the program BAILTEST, is applied to field data from baildown tests. The results indicate that hydrographs of water and oil levels are accurately described by the model

Relationship of carotid arterial functional and structural changes to left atrial volume in untreated hypertension.

Science.gov (United States)

Jaroch, Joanna; Rzyczkowska, Barbara; Bociąga, Zbigniew; Vriz, Olga; Driussi, Caterina; Loboz-Rudnicka, Maria; Dudek, Krzysztof; Łoboz-Grudzień, Krystyna

2016-04-01

The contribution of arterial functional and structural changes to left ventricular (LV) diastolic dysfunction has been the area of recent research. There are some studies on the relationship between arterial stiffness (a.s.) and left atrial (LA) remodelling as a marker of diastolic burden. Little is known about the association of arterial structural changes and LA remodelling in hypertension (H). The aim of this study was to examine the relationship between carotid a.s. and intima-media thickness (IMT) and LA volume in subjects with H. The study included 245 previously untreated hypertensives (166 women and 79 men, mean age 53.7 ± 11.8 years). Each patient was subjected to echocardiography with measurement of LA volume, evaluation of left ventricular hypertrophy (LVH) and LV systolic/diastolic function indices, integrated assessment of carotid IMT and echo-tracking of a.s. and wave reflection parameters. Univariate regression analysis revealed significant correlations between indexed LA volume and selected clinical characteristics, echocardiographic indices of LVH and LV diastolic/systolic function and a.s./wave reflection parameters. The following parameters were identified as independent determinants of indexed LA volume on multivariate regression analysis: diastolic blood pressure (beta = -0.229, P arterial stiffness but not intima-media thickness and LA volume in patients with untreated hypertension.

PET functional volume delineation: a robustness and repeatability study

International Nuclear Information System (INIS)

Hatt, Mathieu; Cheze-le Rest, Catherine; Albarghach, Nidal; Pradier, Olivier; Visvikis, Dimitris

2011-01-01

Current state-of-the-art algorithms for functional uptake volume segmentation in PET imaging consist of threshold-based approaches, whose parameters often require specific optimization for a given scanner and associated reconstruction algorithms. Different advanced image segmentation approaches previously proposed and extensively validated, such as among others fuzzy C-means (FCM) clustering, or fuzzy locally adaptive bayesian (FLAB) algorithm have the potential to improve the robustness of functional uptake volume measurements. The objective of this study was to investigate robustness and repeatability with respect to various scanner models, reconstruction algorithms and acquisition conditions. Robustness was evaluated using a series of IEC phantom acquisitions carried out on different PET/CT scanners (Philips Gemini and Gemini Time-of-Flight, Siemens Biograph and GE Discovery LS) with their associated reconstruction algorithms (RAMLA, TF MLEM, OSEM). A range of acquisition parameters (contrast, duration) and reconstruction parameters (voxel size) were considered for each scanner model, and the repeatability of each method was evaluated on simulated and clinical tumours and compared to manual delineation. For all the scanner models, acquisition parameters and reconstruction algorithms considered, the FLAB algorithm demonstrated higher robustness in delineation of the spheres with low mean errors (10%) and variability (5%), with respect to threshold-based methodologies and FCM. The repeatability provided by all segmentation algorithms considered was very high with a negligible variability of <5% in comparison to that associated with manual delineation (5-35%). The use of advanced image segmentation algorithms may not only allow high accuracy as previously demonstrated, but also provide a robust and repeatable tool to aid physicians as an initial guess in determining functional volumes in PET. (orig.)

Early Expansion of the Intracranial CSF Volume After Palliative Whole-Brain Radiotherapy: Results of a Longitudinal CT Segmentation Analysis

International Nuclear Information System (INIS)

Sanghera, Paul; Gardner, Sandra L.; Scora, Daryl; Davey, Phillip

2010-01-01

Purpose: To assess cerebral atrophy after radiotherapy, we measured intracranial cerebrospinal fluid volume (ICSFV) over time after whole-brain radiotherapy (WBRT) and compared it with published normal-population data. Methods and Materials: We identified 9 patients receiving a single course of WBRT (30 Gy in 10 fractions over 2 weeks) for ipsilateral brain metastases with at least 3 years of computed tomography follow-up. Segmentation analysis was confined to the tumor-free hemi-cranium. The technique was semiautomated by use of thresholds based on scanned image intensity. The ICSFV percentage (ratio of ICSFV to brain volume) was used for modeling purposes. Published normal-population ICSFV percentages as a function of age were used as a control. A repeated-measures model with cross-sectional (between individuals) and longitudinal (within individuals) quadratic components was fitted to the collected data. The influence of clinical factors including the use of subependymal plate shielding was studied. Results: The median imaging follow-up was 6.25 years. There was an immediate increase (p < 0.0001) in ICSFV percentage, which decelerated over time. The clinical factors studied had no significant effect on the model. Conclusions: WBRT immediately accelerates the rate of brain atrophy. This longitudinal study in patients with brain metastases provides a baseline against which the potential benefits of more localized radiotherapeutic techniques such as radiosurgery may be compared.

Sectional analysis for volume determination and selection of volume equations for the Tapajos Nacional Forest

Directory of Open Access Journals (Sweden)

Renato Bezerra da Silva Ribeiro

2014-12-01

Full Text Available The aim of this study was to analyze different sections lengths for volume determination, fitting of volumetric models for timber production estimation in an area of forest management in the Tapajós National Forest (FNT. Six treatments for sectioning were tested in 152 logs of 12 commercial species. The obtained volumes were statistically compared by analysis of variance (ANOVA for the choice of the best method of sectioning and calculating the actual volume of 2,094 sample trees in different diameter commercial classes. Ten mathematical models were fitted to the whole data and to the species Manilkara huberi (Ducke Chevalier (maçaranduba Lecythis lurida (Miers Samori (jarana and Hymenaea courbaril L. (Jatobá. The criteria to choose the best model were adjusted coefficient of determination in percentage (R2adj%, standard error of estimate in percentage (Syx%, significance of the parameters, normality of residuals, Variance Inflation Factor (VIF and residuals graphic distribution. There was no statistical difference between the methods of sectioning and thus the total length of the logs was more operational in the field. The models in logarithmic form of Schumacher and Hall and Spurr were the best to estimate the volume for the species and for the whole sample set.

Experimental heat capacity of solid hydrogen as a function of molar volume

International Nuclear Information System (INIS)

Krause, J.K.

1978-01-01

Constant volume heat capacity measurements have been made on six solid hydrogen samples with low orthohydrogen concentrations. The measurements extend from approximately 1.5 K to the melting line, with molar volumes ranging from 22.787 cm 3 /mole to 16.193 cm 3 /mole. Although clustering of the ortho molecules was observed, the low temperature heat capacity anomaly due to the orthohydrogen pairs could be described quite well by the assumption of a fixed distribution. The data were corrected to obtain a lattice heat capacity which on extrapolation to T = 0 yielded Debye temperatures and a volume dependent Grueneisen parameter. A modified Mie-Grueneisen approximation was used to define a volume and temperature dependent Grueneisen parameter which was used to calculate the equation of state, P(V,T), and isothermal bulk modulus, B/sub T/(V,T), for the six isochores. An extrapolation of the equation of state to T = 0 and P = 0 by two different methods yields a molar volume which, when compared with other determinations, gives a recommended value of 23.20 +- 0.05 cm 3 /mole. A rapid increase in the conversion rate of orthohydrogen to parahydrogen was observed at approximately theta/sub o/12. The molar volumes along the melting curve also have been determined directly for the first time in this volume range. These results have been used to show that a low temperature Lindemann melting relation is only approximately valid for solid hydrogen to 50 K

Application of the Response Surface Methodology to Optimize the Fermentation Parameters for Enhanced Docosahexaenoic Acid (DHA) Production by Thraustochytrium sp. ATCC 26185.

Science.gov (United States)

Wu, Kang; Ding, Lijian; Zhu, Peng; Li, Shuang; He, Shan

2018-04-22

The aim of this study was to determine the cumulative effect of fermentation parameters and enhance the production of docosahexaenoic acid (DHA) by Thraustochytrium sp. ATCC 26185 using response surface methodology (RSM). Among the eight variables screened for effects of fermentation parameters on DHA production by Plackett-Burman design (PBD), the initial pH, inoculum volume, and fermentation volume were found to be most significant. The Box-Behnken design was applied to derive a statistical model for optimizing these three fermentation parameters for DHA production. The optimal parameters for maximum DHA production were initial pH: 6.89, inoculum volume: 4.16%, and fermentation volume: 140.47 mL, respectively. The maximum yield of DHA production was 1.68 g/L, which was in agreement with predicted values. An increase in DHA production was achieved by optimizing the initial pH, fermentation, and inoculum volume parameters. This optimization strategy led to a significant increase in the amount of DHA produced, from 1.16 g/L to 1.68 g/L. Thraustochytrium sp. ATCC 26185 is a promising resource for microbial DHA production due to the high-level yield of DHA that it produces, and the capacity for large-scale fermentation of this organism.

Pulmonary venous flows reflect changes in left atrial hemodynamics during mitral balloon valvotomy.

Science.gov (United States)

Yalçin, Fatih; El-Amrousy, Mahmoud; Müderrisoğlu, Haldun; Korkmaz, Mehmet; Flachskampf, Frank; Tuzcu, Murat; Garcia, Mario G; Thomas, James D

2002-01-01

Patients with mitral stenosis have usually blunted pulmonary venous (PV) flow, because of decreased mitral valve area and diastolic dysfunction. The authors compared changes in Doppler PV velocities by using transesophageal echocardiography (TEE) against hemodynamics parameters before and after mitral balloon valvotomy to observe relevance of PV velocities and endsystolic left atrial (LA) pressure-volume relationship. In 25 patients (aged 35 +/- 17 years) with mitral stenosis in sinus rhythm, changes in LA pressure and volumes were compared with PV velocities before and after valvotomy. Mitral valve area, mitral gradients, and deceleration time were obtained. Mitral valve area and mitral gradients changed from 1 +/- 0.2 cm2 and 14.6 +/- 5.4 mmHg to 1.9 +/- 0.3 cm2 and 6.3 +/- 1.7 mmHg, respectively (pLA pressure were correlated with changes in S/D (r=0.57, pLA pressure-volume relationship were also correlated with changes in S/D (r=0.52, pLA pressure-volume relationship decreased after mitral balloon valvotomy, as a result of a large decrease in pressure. PV systolic/diastolic (S/D) waves ratio reflects endsystolic LA pressure-volume relationship and may be used as another indicator of successful valvotomy.

Ultrasonic measurements and other allied parameters of yttrium soaps in mixed organic solvents

International Nuclear Information System (INIS)

Mehrotra, K.N.; Tandon, K.

1990-01-01

The ultrasonic measurements of yttrium soaps were made in a mixture of 70 % benzene and 30 % dimethylsulfoxide (ν/ν) to determine the critical micelle concentration, soap-solvent interaction and various acoustic and thermodynamic parameters. The values of the CMC decrease with increasing chainlength of fatty acid constituent of the soap molecule and are in agreement with the values obtained from other micellar properties. The various acoustic parameters (intermolecular freelength, adiabatic compressibility, apparent molar compressibility, specific acoustic impedance, apparent molar volume, molar sound velocity, solvation number, available volume and relative association) for yttrium soaps (myristate, palmitate, stearate and oleate) have been evaluated by ultrasonic velocity measurements. (Authors)

Multidimensional correlation among plan complexity, quality and deliverability parameters for volumetric-modulated arc therapy using canonical correlation analysis.

Science.gov (United States)

Shen, Lanxiao; Chen, Shan; Zhu, Xiaoyang; Han, Ce; Zheng, Xiaomin; Deng, Zhenxiang; Zhou, Yongqiang; Gong, Changfei; Xie, Congying; Jin, Xiance

2018-03-01

A multidimensional exploratory statistical method, canonical correlation analysis (CCA), was applied to evaluate the impact of complexity parameters on the plan quality and deliverability of volumetric-modulated arc therapy (VMAT) and to determine parameters in the generation of an ideal VMAT plan. Canonical correlations among complexity, quality and deliverability parameters of VMAT, as well as the contribution weights of different parameters were investigated with 71 two-arc VMAT nasopharyngeal cancer (NPC) patients, and further verified with 28 one-arc VMAT prostate cancer patients. The average MU and MU per control point (MU/CP) for two-arc VMAT plans were 702.6 ± 55.7 and 3.9 ± 0.3 versus 504.6 ± 99.2 and 5.6 ± 1.1 for one-arc VMAT plans, respectively. The individual volume-based 3D gamma passing rates of clinical target volume (γCTV) and planning target volume (γPTV) for NPC and prostate cancer patients were 85.7% ± 9.0% vs 92.6% ± 7.8%, and 88.0% ± 7.6% vs 91.2% ± 7.7%, respectively. Plan complexity parameters of NPC patients were correlated with plan quality (P = 0.047) and individual volume-based 3D gamma indices γ(IV) (P = 0.01), in which, MU/CP and segment area (SA) per control point (SA/CP) were weighted highly in correlation with γ(IV) , and SA/CP, percentage of CPs with SA plan quality with coefficients of 0.98, 0.68 and -0.99, respectively. Further verification with one-arc VMAT plans demonstrated similar results. In conclusion, MU, SA-related parameters and PTV volume were found to have strong effects on the plan quality and deliverability.

DNA-index and stereological estimation of nuclear volume in primary and metastatic malignant melanomas

DEFF Research Database (Denmark)

Sørensen, Flemming Brandt; Kristensen, I B; Grymer, F

1990-01-01

The aim of this study was to investigate the relationship between physical nuclear volume and ploidy level in malignant melanomas, and to analyse the heterogeneity of these two parameters among primary and corresponding secondary tumours. Unbiased stereological estimates of nuclear volume can...

Effect of process parameters on coating composition of cathodic ...

Indian Academy of Sciences (India)

1Department of Mining and Metallurgical Engineering, Amirkabir University of Technology, ... The effect of some process parameters such as electrical conductivity, volume and temperature of ... the subject of numerous studies and found industrial applica- .... tion of positive ions and transfer of their kinetic energy to the.

Experiments to Improve Power Conversion Parameters in a Traveling Wave Direct Energy Converter Simulator

International Nuclear Information System (INIS)

Takeno, Hiromasa; Kiriyama, Yuusuke; Yasaka, Yasuyoshi

2005-01-01

An experimental study of direct power conversion for D- 3 He fusion is presented. In a small-scale simulator of direct energy converter, which is based on a principle of deceleration of 14.7MeV protons by traveling wave field, a new structure of an external transmission circuit in experiment is proposed for the purpose of enhancement of deceleration electrode voltages. A prototype circuit was designed and constructed, resulting improvement of voltage amplitude in an order of magnitude. A more practical circuit, in which inductor elements were manufactured by using coaxial cables, was also constructed and tested. An excitation of the third harmonic frequency with a significant amplitude was observed. The cause of this problem is attributed to the modulated ion beam which has a third harmonic component and fact that the inductance of the element nonlinearly depends on frequency. This problem is serious for a practical scale energy converter, and a careful design of the circuit could avoid the problem

Morphological parameters associated with ruptured posterior communicating aneurysms.

Science.gov (United States)

Ho, Allen; Lin, Ning; Charoenvimolphan, Nareerat; Stanley, Mary; Frerichs, Kai U; Day, Arthur L; Du, Rose

2014-01-01

The rupture risk of unruptured intracranial aneurysms is known to be dependent on the size of the aneurysm. However, the association of morphological characteristics with ruptured aneurysms has not been established in a systematic and location specific manner for the most common aneurysm locations. We evaluated posterior communicating artery (PCoA) aneurysms for morphological parameters associated with aneurysm rupture in that location. CT angiograms were evaluated to generate 3-D models of the aneurysms and surrounding vasculature. Univariate and multivariate analyses were performed to evaluate morphological parameters including aneurysm volume, aspect ratio, size ratio, distance to ICA bifurcation, aneurysm angle, vessel angles, flow angles, and vessel-to-vessel angles. From 2005-2012, 148 PCoA aneurysms were treated in a single institution. Preoperative CTAs from 63 patients (40 ruptured, 23 unruptured) were available and analyzed. Multivariate logistic regression revealed that smaller volume (p = 0.011), larger aneurysm neck diameter (0.048), and shorter ICA bifurcation to aneurysm distance (p = 0.005) were the most strongly associated with aneurysm rupture after adjusting for all other clinical and morphological variables. Multivariate subgroup analysis for patients with visualized PCoA demonstrated that larger neck diameter (p = 0.018) and shorter ICA bifurcation to aneurysm distance (p = 0.011) were significantly associated with rupture. Intracerebral hemorrhage was associated with smaller volume, larger maximum height, and smaller aneurysm angle, in addition to lateral projection, male sex, and lack of hypertension. We found that shorter ICA bifurcation to aneurysm distance is significantly associated with PCoA aneurysm rupture. This is a new physically intuitive parameter that can be measured easily and therefore be readily applied in clinical practice to aid in the evaluation of patients with PCoA aneurysms.

Accuracy of cancellous bone volume fraction measured by micro-CT scanning

DEFF Research Database (Denmark)

Ding, Ming; Odgaard, A; Hvid, I

1999-01-01

Volume fraction, the single most important parameter in describing trabecular microstructure, can easily be calculated from three-dimensional reconstructions of micro-CT images. This study sought to quantify the accuracy of this measurement. One hundred and sixty human cancellous bone specimens...... which covered a large range of volume fraction (9.8-39.8%) were produced. The specimens were micro-CT scanned, and the volume fraction based on Archimedes' principle was determined as a reference. After scanning, all micro-CT data were segmented using individual thresholds determined by the scanner...

Positron annihilation study on free volume of amino acid modified, starch-grafted acrylamide copolymer

International Nuclear Information System (INIS)

Mahmoud, K.R.; Al-Sigeny, S.; Sharshar, T.; El-Hamshary, H.

2006-01-01

Free volume measurements using positron annihilation lifetime spectroscopy was performed for uncrosslinked and crosslinked starch-grafted polyacrylamide, and their modified amino acid samples including some of their iron(III) complexes. The measurements were performed at room temperature. The analysis of lifetime spectra yielded mostly three lifetime components. It was observed that the values of the short lifetime component τ 1 are slightly higher than the lifetime associated with the self-decay of para-positronium atoms in polymers. The free volume was probed using ortho-positronium pick-off annihilation lifetime parameters. The mean free volume has also been calculated from the lifetime data. The avrage value of this parameter of the crosslinked polymer were found to be higher than those of the uncrosslinked polymer

Application of grey system theory on the influencing parameters of aerobic granulation in SBR.

Science.gov (United States)

Bindhu, B K; Madhu, G

2017-09-01

Aerobic granulation is a promising technology for wastewater treatment. Four operational parameters were selected as influencing factors for this study. Aerobic granulation was experimented with three different values of organic loading rate (3, 6 and 9 kg COD m -3  d -1 ), superficial upflow air velocity (SUAV) (2, 3 and 4 cm s -1 ), settling time (3, 5 and 10 min) and volume exchange ratio (25%, 50% and 75%) in sequencing batch reactor in nine trials for the optimal performance of aerobic granulation. The influence of compared parameters on five reference parameters (sludge volume index (SVI), time taken for the appearance of granules, size and specific gravity of granules and chemical oxygen demand (COD) removal) was analyzed using grey system theory. The grey relational coefficients and grey entropy relational grade of each parameter were calculated. Hydrodynamic shear force in terms of SUAV was found to have the greatest influence on granule appearance, specific gravity of granules and COD removal efficiency. SVI is greatly affected by settling time. The optimal scopes of all the compared parameters were found.

OPTIMUM VOLUME OF BANK RESERVE: FORECASTING OF OVERDUE CREDIT INDEBTEDNESS USING COPULA MODELS

Directory of Open Access Journals (Sweden)

Kazakova K. A.

2015-12-01

Full Text Available The article propose to consider the possibility of RLUF-copulas application for the creation of joint distributions of overdue credit indebtedness ranks with macroeconomic indicators for the purpose of indebtedness forecasting and also for the definition of optimum volumes of reserve requirements for the corresponding losses. In this research the comparative analysis of multivariate distributions of RLUF-copula estimation with such classical copulas, as FGM-copula, Frank's copula and Gauss's copula is made. In the article the method of maximum likelihood is used for receiving estimates of model parameters. In case of RLUF-copula Bayesian estimates of parameters are received using the Metropolis algorithm with random volatility. Forecasting of bank reserve volumes for all received models is executed in the form of random sample generation by the means of the algorithm of acceptance-deviation for the creation of the corresponding sample of joint distribution using the copula density function. As the result of playing of hundred possible scenarios of indebtedness volumes is obtained the 95 % confidence level for the possible volume of credit indebtedness which can fully act as the optimum volume of reserve requirements for the corresponding credit losses.

Setting parameters in the cold chain

Directory of Open Access Journals (Sweden)

Victoria Rodríguez

2011-12-01

Full Text Available Breaks in the cold chain are important economic losses in food and pharmaceutical companies. Many of the failures in the cold chain are due to improper adjustment of equipment parameters such as setting the parameters for theoretical conditions, without a corresponding check in normal operation. The companies that transport refrigeratedproducts must be able to adjust the parameters of the equipment in an easy and quick to adapt their functioning to changing environmental conditions. This article presents the results of a study carried out with a food distribution company. The main objective of the study is to verify the effectiveness of Six Sigma as a methodological toolto adjust the equipment in the cold chain. The second objective is more speciÞ c and is to study the impact of: reducing the volume of storage in the truck, the initial temperature of the storage areain the truck and the frequency of defrost in the transport of refrigerated products.

Review of Random Phase Encoding in Volume Holographic Storage

Directory of Open Access Journals (Sweden)

Wei-Chia Su

2012-09-01

Full Text Available Random phase encoding is a unique technique for volume hologram which can be applied to various applications such as holographic multiplexing storage, image encryption, and optical sensing. In this review article, we first review and discuss diffraction selectivity of random phase encoding in volume holograms, which is the most important parameter related to multiplexing capacity of volume holographic storage. We then review an image encryption system based on random phase encoding. The alignment of phase key for decryption of the encoded image stored in holographic memory is analyzed and discussed. In the latter part of the review, an all-optical sensing system implemented by random phase encoding and holographic interconnection is presented.

Small-Volume Injections: Evaluation of Volume Administration Deviation From Intended Injection Volumes.

Science.gov (United States)

Muffly, Matthew K; Chen, Michael I; Claure, Rebecca E; Drover, David R; Efron, Bradley; Fitch, William L; Hammer, Gregory B

2017-10-01

In the perioperative period, anesthesiologists and postanesthesia care unit (PACU) nurses routinely prepare and administer small-volume IV injections, yet the accuracy of delivered medication volumes in this setting has not been described. In this ex vivo study, we sought to characterize the degree to which small-volume injections (≤0.5 mL) deviated from the intended injection volumes among a group of pediatric anesthesiologists and pediatric postanesthesia care unit (PACU) nurses. We hypothesized that as the intended injection volumes decreased, the deviation from those intended injection volumes would increase. Ten attending pediatric anesthesiologists and 10 pediatric PACU nurses each performed a series of 10 injections into a simulated patient IV setup. Practitioners used separate 1-mL tuberculin syringes with removable 18-gauge needles (Becton-Dickinson & Company, Franklin Lakes, NJ) to aspirate 5 different volumes (0.025, 0.05, 0.1, 0.25, and 0.5 mL) of 0.25 mM Lucifer Yellow (LY) fluorescent dye constituted in saline (Sigma Aldrich, St. Louis, MO) from a rubber-stoppered vial. Each participant then injected the specified volume of LY fluorescent dye via a 3-way stopcock into IV tubing with free-flowing 0.9% sodium chloride (10 mL/min). The injected volume of LY fluorescent dye and 0.9% sodium chloride then drained into a collection vial for laboratory analysis. Microplate fluorescence wavelength detection (Infinite M1000; Tecan, Mannedorf, Switzerland) was used to measure the fluorescence of the collected fluid. Administered injection volumes were calculated based on the fluorescence of the collected fluid using a calibration curve of known LY volumes and associated fluorescence.To determine whether deviation of the administered volumes from the intended injection volumes increased at lower injection volumes, we compared the proportional injection volume error (loge [administered volume/intended volume]) for each of the 5 injection volumes using a linear

Volume definition system for treatment planning

International Nuclear Information System (INIS)

Alakuijala, Jyrki; Pekkarinen, Ari; Puurunen, Harri

1997-01-01

Purpose: Volume definition is a difficult and time consuming task in 3D treatment planning. We have studied a systems approach for constructing an efficient and reliable set of tools for volume definition. Our intent is to automate body outline, air cavities and bone volume definition and accelerate definition of other anatomical structures. An additional focus is on assisting in definition of CTV and PTV. The primary goals of this work are to cut down the time used in contouring and to improve the accuracy of volume definition. Methods: We used the following tool categories: manual, semi-automatic, automatic, structure management, target volume definition, and visualization tools. The manual tools include mouse contouring tools with contour editing possibilities and painting tools with a scaleable circular brush and an intelligent brush. The intelligent brush adapts its shape to CT value boundaries. The semi-automatic tools consist of edge point chaining, classical 3D region growing of single segment and competitive volume growing of multiple segments. We tuned the volume growing function to take into account both local and global region image values, local volume homogeneity, and distance. Heuristic seeding followed with competitive volume growing finds the body outline, couch and air automatically. The structure management tool stores ICD-O coded structures in a database. The codes have predefined volume growing parameters and thus are able to accommodate the volume growing dissimilarity function for different volume types. The target definition tools include elliptical 3D automargin for CTV to PTV transformation and target volume interpolation and extrapolation by distance transform. Both the CTV and the PTV can overlap with anatomical structures. Visualization tools show the volumes as contours or color wash overlaid on an image and displays voxel rendering or translucent triangle mesh rendering in 3D. Results: The competitive volume growing speeds up the

Radiation-induced liver disease after stereotactic body radiotherapy for small hepatocellular carcinoma: clinical and dose-volumetric parameters

International Nuclear Information System (INIS)

Jung, Jinhong; Choi, Eun Kyung; Kim, Jong Hoon; Yoon, Sang Min; Kim, So Yeon; Cho, Byungchul; Park, Jin-hong; Kim, Su Ssan; Song, Si Yeol; Lee, Sang-wook; Ahn, Seung Do

2013-01-01

To investigate the clinical and dose–volumetric parameters that predict the risk of radiation-induced liver disease (RILD) for patients with small, unresectable hepatocellular carcinoma (HCC) treated with stereotactic body radiotherapy (SBRT). Between March 2007 and December 2009, 92 patients with HCC treated with SBRT were reviewed for RILD within 3 months of completing treatment. RILD was evaluated according to the Common Terminology Criteria for Adverse Events, version 3.0. A dose of 10–20 Gy (median, 15 Gy) per fraction was given over 3–4 consecutive days for a total dose of 30–60 Gy (median, 45 Gy). The following clinical and dose–volumetric parameters were examined: age, gender, Child-Pugh class, presence of hepatitis B virus, gross tumor volume, normal liver volume, radiation dose, fraction size, mean dose to the normal liver, and normal liver volumes receiving from < 5 Gy to < 60 Gy (in increments of 5 Gy). Seventeen (18.5%) of the 92 patients developed grade 2 or worse RILD after SBRT (49 patients in grade 1, 11 in grade 2, and 6 in ≥ grade 3). On univariate analysis, Child-Pugh class was identified as a significant clinical parameter, while normal liver volume and normal liver volumes receiving from < 15 Gy to < 60 Gy were the significant dose–volumetric parameters. Upon multivariate analysis, only Child-Pugh class was a significant parameter for predicting grade 2 or worse RILD. The Child-Pugh B cirrhosis was found to have a significantly greater susceptibility to the development of grade 2 or worse RILD after SBRT in patients with small, unresectable HCC. Additional efforts aimed at testing other models to predict the risk of RILD in a large series of HCC patients treated with SBRT are needed

Parameters. U.S. Army War College Quarterly. Volume 20, Number 2

Science.gov (United States)

1990-06-01

resigned to the grave. Thus, for the sane soldier who holds life dear, fear is an ever-present companion , and, not surprisingly, its effects can be...abstract good, but because they 40 Parameters realized that by fleeing their post and rescuing themselves, they would expose their companions to greater...comrades at the same time that he counts on them for his own survival. Killer Angels Once Chamberlain had a speech memorized from Shakespeare and gave

Assessment of Abdominal Fat Using High-field Magnetic Resonance Imaging and Anthropometric and Biochemical Parameters.

Science.gov (United States)

Al-Radaideh, Ali; Tayyem, Reema; Al-Fayomi, Kholoud; Nimer, Nisreen; Malkawi, Amer; Al-Zu Bi, Rana; Agraib, Lana; Athamneh, Imad; Hijjawi, Nawal

2016-12-01

To measure the abdominal subcutaneous fat (SF) and visceral fat (VF) volumes using high-field magnetic resonance imaging (MRI) and to investigate their association with selected anthropometric and biochemical parameters among obese and nonobese apparently healthy participants. A cross-sectional study was conducted by recruiting 167 healthy participants. Abdominal scans were acquired at 3T MRI, and the SF and VF were segmented and their volumes were calculated. Selected anthropometric and biochemical measurements were also determined. A significant difference (P abdominal fat volumes, leptin, resistin, adiponectin and waist circumference. Waist circumferences were measured by tape and MRI. Findings revealed that MRI-measured fat volumes were different between males and females and had a significant (P fat volumes were found to correlate moderately with interleukin-6 and weakly with cholesterol, serum triglyceride and low-density lipoprotein. Except for cholesterol, all measured biochemical variables and abdominal fat volumes in the current study were significantly associated with body mass index. All anthropometric and biochemical parameters showed weak-to-strong associations with the MRI-measured fat volumes. Abdominal fat distribution was different between males and females and their correlations with some lipid profiles were found to be sex dependent. These findings revealed that MRI can be used as an alternative tool for obesity assessment. Copyright © 2016 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

Experimental estimation of regional lung water volume by histogram of pulmonary CT numbers

International Nuclear Information System (INIS)

Kato, Shiro; Momoki, Shigeru; Asai, Toshihiko; Shimada, Takeshi; Tamano, Masahiro; Nakamoto, Takaaki; Yoshimura, Masaharu

1989-01-01

Both in vitro and in vivo experiments were made to assess the ability of pulmonary CT numbers to quantitatively determine regional water volume in cases of pulmonary congestion or edema associated with left heart failure. In vitro experiment revealed a good linear correlation between the volume of injected water and the determined CT number of polyethylene tube packed with sponge. In the subsequent in vivo experiment with 10 adult mongrel dogs, lung water volumes obtained by pulmonary CT numbers were found to be consistent with the actual volumes. Pulmonary CT numbers for water volume proved to become parameters to quantitatively evaluate pulmonary congestion or edema. (Namekawa, K)

Relaxation volumes of self-interstitial-atoms and vacancies in metals

International Nuclear Information System (INIS)

Ehrhart, P.

1983-01-01

Experimental results for the relaxation volumes of self-interstitial-atoms and vacancies as obtained after low temperature irradiation of different metals are reviewed. For fcc metals the relaxation volumes of the SIA's are very similar: ΔVsup(rel) = 1.6 +- 0.3 atomic volumes. This value is valid as well for the pure fcc metals (Al, Cu, Ni) as for different alloys. Vacancy relaxation volumes are small and vary between: ΔVsup(rel) = -0.05 and -0.25 atomic volumes. For bcc metals (Fe, Mo) the relaxation volume of the SIA is significantly smaller: ΔVsup(rel) = 1.1 +- 0.2 atomic volumes. In spite of the obvious similarity of the close-packed fcc and hcp structures, the SIA parameters for hcp metals are much different: ΔVsup(rel) = 3.5 for Zn, ΔVsup(rel) = 1.5 for Co and ΔVsup(rel) = 0.6 at. vol. for Zr. Vacancy relaxation volumes seem to be small as in cubic metals. The influence of lattice nonharmonicity on the validity of an extrapolation of the values determined at 6 K to higher temperatures is discussed. (author)

Plasma diagnostics discharge parameters and chemistry

CERN Document Server

Auciello, Orlando

1989-01-01

Plasma Diagnostics, Volume 1: Discharge Parameters and Chemistry covers seven chapters on the important diagnostic techniques for plasmas and details their use in particular applications. The book discusses optical diagnostic techniques for low pressure plasmas and plasma processing; plasma diagnostics for electrical discharge light sources; as well as Langmuir probes. The text also describes the mass spectroscopy of plasmas, microwave diagnostics, paramagnetic resonance diagnostics, and diagnostics in thermal plasma processing. Electrical engineers, nuclear engineers, microwave engineers, che

A study of Channeling, Volume Reflection and Volume Capture of 3.35 - 14.0 GeV Electrons in a bent Silicon Crystal

Energy Technology Data Exchange (ETDEWEB)

Wistisen, T. N. [Aarhus Univ. (Denmark); Uggerhoj, U. I. [Aarhus Univ. (Denmark); Wienands, U. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Markiewicz, T. W. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Noble, R. J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Benson, B. L. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Smith, T. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Bagli, E. [Univ. of Ferrara (Italy); Bandiera, L. [Univ. of Ferrara (Italy); Germogli, G. [Univ. of Ferrara (Italy); Guidi, V. [Univ. of Ferrara (Italy); Mazzolari, A. [Univ. of Ferrara (Italy); Holtzapple, R. [California Polytechnic State Univ. (CalPoly), San Luis Obispo, CA (United States); Tucker, S. [California Polytechnic State Univ. (CalPoly), San Luis Obispo, CA (United States)

2015-12-03

We present the experimental data and analysis of experiments conducted at SLAC National Accelerator Laboratory investigating the processes of channeling, volume-reflection and volume-capture along the (111) plane in a strongly bent quasi-mosaic silicon crystal. Additionally, these phenomena were investigated at 5 energies: 3.35, 4.2, 6.3, 10.5 and 14.0 GeV with a crystal with bending radius of 0.15m, corresponding to curvatures of 0.070, 0.088, 0.13, 0.22 and 0.29 times the critical curvature respectively. We have extracted important parameters describing the channeling process such as the dechanneling length, the angle of volume reflection, the surface transmission and the widths of the distribution of channeled particles parallel and orthogonal to the plane.

Moderator's view: High-volume plasma exchange: pro, con and consensus.

Science.gov (United States)

Kaplan, Andre A

2017-09-01

I have been asked to comment on the pro and con opinions regarding high-volume plasma exchange. The authors of both positions have provided cogent arguments and a reasonable approach to choosing the exchange volume for any given therapeutic plasma exchange. The major issue of relevance in this discussion is the nature of the toxins targeted for removal. These parameters include molecular weight, the apparent volume of distribution, the degree of protein binding, the biologic and chemical half-life, and the severity and rapidity of its toxicity. © The Author 2017. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

Use of PET volume determination by fuzzy logic in the follow up of lymphomas treated by radio-immunotherapy

International Nuclear Information System (INIS)

Esnault, J.M.; Steinling, M.; Huglo, D.; Vermandel, M.; Vermandel, M.; Steinling, M.; Huglo, D.; Morschhauser, F.

2007-01-01

Purposes: the aim of this study was to assess if the evaluation of tumoral volumes by fuzzy logic was workable for clinical use. This study was performed with patients followed up for radio-immunotherapy of non-Hodgkin's lymphomas with a comparison of the respective contributions of this quantification and Standardized Uptake Value (S.U.V.). Materials and methods: thirty patients underwent 18 F-FDG PET before treatment and then in an iterative way. The analysis of 217 lesions allowed to evaluate their volumes and S.U.V.. The evolution of these parameters of quantification was compared. Results: these two quantitative parameters did not statistically differ but there were important discrepancies in some examinations. The determination of volumes was sometimes limited by tumoral localization or junction of lesions. Conclusion: this study proved the feasibility of the determination of tumoral volumes by fuzzy method in clinical use. Quantification supplemented the subjective visual analysis, which in most cases was sufficient to appreciate the progression of the disease. This quantification, usually given by the value of the S.U.V., could be improved by the volume data either in a separated way, or combining intensity and volume (total lesion glycolysis). Further work is necessary to specify the predictive value of these parameters in this particular indication. (authors)

FIRST OBSERVATIONAL SIGNATURE OF ROTATIONAL DECELERATION IN A MASSIVE, INTERMEDIATE-AGE STAR CLUSTER IN THE MAGELLANIC CLOUDS

Energy Technology Data Exchange (ETDEWEB)

Wu, Xiaohan [School of Physics, Peking University, Yi He Yuan Lu 5, Hai Dian District, Beijing 100871 (China); Li, Chengyuan; De Grijs, Richard [Kavli Institute for Astronomy and Astrophysics and Department of Astronomy, Peking University, Yi He Yuan Lu 5, Hai Dian District, Beijing 100871 (China); Deng, Licai, E-mail: grijs@pku.edu.cn [Key Laboratory for Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012 (China)

2016-07-20

While the extended main-sequence turnoffs (eMSTOs) found in almost all 1–2 Gyr old star clusters in the Magellanic Clouds are often explained by postulating extended star formation histories (SFHs), the tight subgiant branches (SGBs) seen in some clusters challenge this popular scenario. Puzzlingly, the SGB of the eMSTO cluster NGC 419 is significantly broader at bluer than at redder colors. We carefully assess and confirm the reality of this observational trend. If we would assume that the widths of the features in color–magnitude space were entirely owing to a range in stellar ages, the SFHs of the eMSTO stars and the blue SGB region would be significantly more prolonged than that of the red part of the SGB. This cannot be explained by assuming an internal age spread. We show that rotational deceleration of a population of rapidly rotating stars, a currently hotly debated alternative scenario, naturally explains the observed trend along the SGB. Our analysis shows that a “converging” SGB could be produced if the cluster is mostly composed of rapidly rotating stars that slow down over time owing to the conservation of angular momentum during their evolutionary expansion from main-sequence turnoff stars to red giants.

On the Use of Generalized Volume Scattering Models for the Improvement of General Polarimetric Model-Based Decomposition

Directory of Open Access Journals (Sweden)

Qinghua Xie

2017-01-01

Full Text Available Recently, a general polarimetric model-based decomposition framework was proposed by Chen et al., which addresses several well-known limitations in previous decomposition methods and implements a simultaneous full-parameter inversion by using complete polarimetric information. However, it only employs four typical models to characterize the volume scattering component, which limits the parameter inversion performance. To overcome this issue, this paper presents two general polarimetric model-based decomposition methods by incorporating the generalized volume scattering model (GVSM or simplified adaptive volume scattering model, (SAVSM proposed by Antropov et al. and Huang et al., respectively, into the general decomposition framework proposed by Chen et al. By doing so, the final volume coherency matrix structure is selected from a wide range of volume scattering models within a continuous interval according to the data itself without adding unknowns. Moreover, the new approaches rely on one nonlinear optimization stage instead of four as in the previous method proposed by Chen et al. In addition, the parameter inversion procedure adopts the modified algorithm proposed by Xie et al. which leads to higher accuracy and more physically reliable output parameters. A number of Monte Carlo simulations of polarimetric synthetic aperture radar (PolSAR data are carried out and show that the proposed method with GVSM yields an overall improvement in the final accuracy of estimated parameters and outperforms both the version using SAVSM and the original approach. In addition, C-band Radarsat-2 and L-band AIRSAR fully polarimetric images over the San Francisco region are also used for testing purposes. A detailed comparison and analysis of decomposition results over different land-cover types are conducted. According to this study, the use of general decomposition models leads to a more accurate quantitative retrieval of target parameters. However, there

Interactive Dynamic Volume Illumination with Refraction and Caustics.

Science.gov (United States)

Magnus, Jens G; Bruckner, Stefan

2018-01-01

In recent years, significant progress has been made in developing high-quality interactive methods for realistic volume illumination. However, refraction - despite being an important aspect of light propagation in participating media - has so far only received little attention. In this paper, we present a novel approach for refractive volume illumination including caustics capable of interactive frame rates. By interleaving light and viewing ray propagation, our technique avoids memory-intensive storage of illumination information and does not require any precomputation. It is fully dynamic and all parameters such as light position and transfer function can be modified interactively without a performance penalty.

[Target volume margins for lung cancer: internal target volume/clinical target volume].

Science.gov (United States)

Jouin, A; Pourel, N

2013-10-01

The aim of this study was to carry out a review of margins that should be used for the delineation of target volumes in lung cancer, with a focus on margins from gross tumour volume (GTV) to clinical target volume (CTV) and internal target volume (ITV) delineation. Our review was based on a PubMed literature search with, as a cornerstone, the 2010 European Organisation for Research and Treatment of Cancer (EORTC) recommandations by De Ruysscher et al. The keywords used for the search were: radiotherapy, lung cancer, clinical target volume, internal target volume. The relevant information was categorized under the following headings: gross tumour volume definition (GTV), CTV-GTV margin (first tumoural CTV then nodal CTV definition), in field versus elective nodal irradiation, metabolic imaging role through the input of the PET scanner for tumour target volume and limitations of PET-CT imaging for nodal target volume definition, postoperative radiotherapy target volume definition, delineation of target volumes after induction chemotherapy; then the internal target volume is specified as well as tumoural mobility for lung cancer and respiratory gating techniques. Finally, a chapter is dedicated to planning target volume definition and another to small cell lung cancer. For each heading, the most relevant and recent clinical trials and publications are mentioned. Copyright © 2013. Published by Elsevier SAS.

Transient regimes during high-temperature deformation of a bulk metallic glass: A free volume approach

International Nuclear Information System (INIS)

Bletry, M.; Guyot, P.; Brechet, Y.; Blandin, J.J.; Soubeyroux, J.L.

2007-01-01

The homogeneous deformation of a zirconium-based bulk metallic glass is investigated in the glass transition range. Compression and stress-relaxation tests have been conducted. The stress-strain curves are modeled in the framework of the free volume theory, including transient phenomena (overshoot and undershoot). This approach allows several physical parameters (activation volume, flow defect creation and relaxation coefficient) to be determined from a mechanical experiment. This model is able to rationalize the dependency of stress overshoot on relaxation time. It is shown that, due to the relationship between flow defect concentration and free volume model, it is impossible to determine the equilibrium flow defect concentration. However, the relative variation of flow defect is always the same, and all the model parameters depend on the equilibrium flow defect concentration. The methodology presented in this paper should, in the future, allow the consistency of the free volume model to be assessed

Role of intracanalicular volumetric and dosimetric parameters on hearing preservation after vestibular schwannoma radiosurgery

International Nuclear Information System (INIS)

Massager, Nicolas; Nissim, Ouzi; Delbrouck, Carine; Devriendt, Daniel; David, Philippe; Desmedt, Francoise; Wikler, David; Hassid, Sergio; Brotchi, Jacques; Levivier, Marc

2006-01-01

Purpose: To analyze the relationship between hearing preservation after gamma knife radiosurgery (GKR) for vestibular schwannoma (VS) and some volumetric and dosimetric parameters of the intracanalicular components of VS. Methods and Materials: This study included 82 patients with a VS treated by GKR; all patients had no NF2 disease, a Gardner-Robertson hearing class 1-4 before treatment, a marginal dose of 12 Gy, and a radiologic and audiologic follow-up ≥1 year post-GKR. The volume of both the entire tumor and the intracanalicular part of the tumor and the mean and integrated dose of these two volumes were correlated to the auditory outcomes of patients. Results: At last hearing follow-up, 52 patients had no hearing worsening, and 30 patients had an increase of ≥1 class on Gardner-Robertson classification. We found that hearing preservation after GKR is significantly correlated with the intracanalicular tumor volume, as well as with the integrated dose delivered to the intracanalicular tumor volume. Conclusions: Some volumetric and dosimetric parameters of the intracanalicular part of the tumor influence hearing preservation after GKR of VS. Consequently, we advise the direct treatment of patients with preserved functional hearing and a VS including a small intracanalicular volume

Alternative free volume models and positron cages for the characterisation of nanoporosity in materials

International Nuclear Information System (INIS)

Felix, M.V.; Morones, R.; Castano, V.M.

2004-01-01

Three semi-empirical positron stationary Quantum Models were developed for the study of nanoporosity in a wide range of solid porous materials. The cubic, conic and cylindrical well potentials were considered and their geometric parameters related to the Positron Annihilation LifeTime (PALT) measurements. If a conic or a cubic symmetry is assumed, a resonance lifetime phenomenon was found, which enables proposal of a technique to catch positrons in free volume sites. In the cylindrical case, an alternative method to determine free volume sizes in materials was developed. The free volume equations of these new models were then compared to the well-known and widely utilised Spherical Free Volume Model (SFVM) and remarkable differences were found. A strong variation of the free volume size-positron lifetime relation with the geometry involved was observed and a remarkable dependence of the electron layer thickness parameter ΔR with the hole-shape under study and with the nature of the material considered. The mathematical functions appearing in the conic and cylindrical cases are the superposition of Bessel functions of the first kind and trigonometric functions in the cubic case. Generalised free volume diagrams were constructed and a brief geometrical scheme of the diverse cases considered was obtained. (author)

Neuropsychology, Autobiographical Memory, and Hippocampal Volume in “Younger” and “Older” Patients with Chronic Schizophrenia

Science.gov (United States)

Herold, Christina Josefa; Lässer, Marc Montgomery; Schmid, Lena Anna; Seidl, Ulrich; Kong, Li; Fellhauer, Iven; Thomann, Philipp Arthur; Essig, Marco; Schröder, Johannes

2015-01-01

Despite a wide range of studies on neuropsychology in schizophrenia, autobiographical memory (AM) has been scarcely investigated in these patients. Hence, less is known about AM in older patients and hippocampal contribution to autobiographical memories of varying remoteness. Therefore, we investigated hippocampal volume and AM along with important neuropsychological domains in patients with chronic schizophrenia and the respective relationships between these parameters. We compared 25 older patients with chronic schizophrenia to 23 younger patients and an older healthy control group (N = 21) with respect to AM, additional neuropsychological parameters, and hippocampal volume. Personal episodic and semantic memory was investigated using a semi-structured interview. Additional neuropsychological parameters were assessed by using a battery of standard neuropsychological tests. Structural magnetic resonance imaging data were analyzed with an automated region-of-interest procedure. While hippocampal volume reduction and neuropsychological impairment were more pronounced in the older than in the younger patients, both groups showed equivalent reduced AM performance for recent personal episodes. In the patient group, significant correlations between left hippocampal volume and recent autobiographical episodes as well as personal semantic memories arose. Verbal memory and working memory were significantly correlated with right hippocampal volume; executive functions, however, were associated with bilateral hippocampal volumes. These findings underline the complexity of AM and its impairments in the course of schizophrenia in comparison to rather progressive neuropsychological deficits and address the importance of hippocampal contribution. PMID:25954208

THE EFFICACY OF ANGLE-MATCHED ISOKINETIC KNEE FLEXOR AND EXTENSOR STRENGTH PARAMETERS IN PREDICTING AGILITY TEST PERFORMANCE.

Science.gov (United States)

Greig, Matt; Naylor, James

2017-10-01

Agility is a fundamental performance element in many sports, but poses a high risk of injury. Hierarchical modelling has shown that eccentric hamstring strength is the primary determinant of agility performance. The purpose of this study was to investigate the relationship between knee flexor and extensor strength parameters and a battery of agility tests. Controlled laboratory study. Nineteen recreational intermittent games players completed an agility battery and isokinetic testing of the eccentric knee flexors (eccH) and concentric knee extensors (conQ) at 60, 180 and 300°·s -1 . Peak torque and the angle at which peak torque occurred were calculated for eccH and conQ at each speed. Dynamic control ratios (eccH:conQ) and fast:slow ratios (300:60) were calculated using peak torque values, and again using angle-matched data, for eccH and conQ. The agility test battery differentiated linear vs directional changes and prescriptive vs reactive tasks. Linear regression showed that eccH parameters were generally a better predictor of agility performance than conQ parameters. Stepwise regression showed that only angle-matched strength ratios contributed to the prediction of each agility test. Trdaitionally calculated strength ratios using peak torque values failed to predict performance. Angle-matched strength parameters were able to account for 80% of the variation in T-test performance, 70% of deceleration distance, 55% of 10m sprint performance, and 44% of reactive change of direction speed. Traditionally calculated strength ratios failed to predict agility performance, whereas angle-matched strength ratios had better predictive ability and featured in a predictive stepwise model for each agility task. 2c.

Measurement of Trabecular Bone Parameters in Porcine Vertebral Bodies Using Multidetector CT: Evaluation of Reproducibility of 3-Dimensional CT Histomorphometry

Energy Technology Data Exchange (ETDEWEB)

Hong, Sung Hwan; Goo, Jin Mo [Dept. of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul (Korea, Republic of); Moon Kyung Chul [Dept. of Pathology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul (Korea, Republic of); An, Sang Bu [Dept. of radiology, National Cancer Center, Goyang (Korea, Republic of); Kim, Kwang Gi [Dept. of Biomedical Engineering, Division of Basic and Applied Sciences, National Cancer Center, Goyang (Korea, Republic of)

2011-05-15

To evaluate the reproducibility of 3-dimensional histomorphometry for the microarchitecture analysis of trabecular bone parameters using multidetector computed tomography (MDCT). Thirty-six specimens from porcine vertebral bodies were imaged five times with a 64- detector row MDCT system using the same scan protocols. Locations of the specimens were nearly identical through the scans. Three-dimensional structural parameters of trabecular bone were derived from the five data sets using image analyzing software. The features measured by the analysis programs were trabecular bone volume, trabecular bone volume/tissue volume, trabecular thickness, trabecular separation, trabecular number, trabecular bone pattern factor, structural model index. The structural trabecular parameters showed excellent reproducibility through repeated scanning. Intraclass correlation coefficients of all seven structural parameters were in the range of 0.998 to 1.000. Coefficients of variation of the six structural parameters, excluding structural model index, were not over 1.6%. The measurement of the trabecular structural parameters using multidetector CT and three-dimensional histomophometry analysis program was validated and showed excellent reproducibility. This method could be used as a noninvasive and easily available test in a clinical setting.

Viscous cosmology in new holographic dark energy model and the cosmic acceleration

International Nuclear Information System (INIS)

Singh, C.P.; Srivastava, Milan

2018-01-01

In this work, we study a flat Friedmann-Robertson-Walker universe filled with dark matter and viscous new holographic dark energy. We present four possible solutions of the model depending on the choice of the viscous term. We obtain the evolution of the cosmological quantities such as scale factor, deceleration parameter and transition redshift to observe the effect of viscosity in the evolution. We also emphasis upon the two independent geometrical diagnostics for our model, namely the statefinder and the Om diagnostics. In the first case we study new holographic dark energy model without viscous and obtain power-law expansion of the universe which gives constant deceleration parameter and statefinder parameters. In the limit of the parameter, the model approaches to ΛCDM model. In new holographic dark energy model with viscous, the bulk viscous coefficient is assumed as ζ = ζ 0 + ζ 1 H, where ζ 0 and ζ 1 are constants, and H is the Hubble parameter. In this model, we obtain all possible solutions with viscous term and analyze the expansion history of the universe. We draw the evolution graphs of the scale factor and deceleration parameter. It is observed that the universe transits from deceleration to acceleration for small values of ζ in late time. However, it accelerates very fast from the beginning for large values of ζ. By illustrating the evolutionary trajectories in r - s and r - q planes, we find that our model behaves as an quintessence like for small values of viscous coefficient and a Chaplygin gas like for large values of bulk viscous coefficient at early stage. However, model has close resemblance to that of the ΛCDM cosmology in late time. The Om has positive and negative curvatures for phantom and quintessence models, respectively depending on ζ. Our study shows that the bulk viscosity plays very important role in the expansion history of the universe. (orig.)

Viscous cosmology in new holographic dark energy model and the cosmic acceleration

Science.gov (United States)

Singh, C. P.; Srivastava, Milan

2018-03-01

In this work, we study a flat Friedmann-Robertson-Walker universe filled with dark matter and viscous new holographic dark energy. We present four possible solutions of the model depending on the choice of the viscous term. We obtain the evolution of the cosmological quantities such as scale factor, deceleration parameter and transition redshift to observe the effect of viscosity in the evolution. We also emphasis upon the two independent geometrical diagnostics for our model, namely the statefinder and the Om diagnostics. In the first case we study new holographic dark energy model without viscous and obtain power-law expansion of the universe which gives constant deceleration parameter and statefinder parameters. In the limit of the parameter, the model approaches to Λ CDM model. In new holographic dark energy model with viscous, the bulk viscous coefficient is assumed as ζ =ζ 0+ζ 1H, where ζ 0 and ζ 1 are constants, and H is the Hubble parameter. In this model, we obtain all possible solutions with viscous term and analyze the expansion history of the universe. We draw the evolution graphs of the scale factor and deceleration parameter. It is observed that the universe transits from deceleration to acceleration for small values of ζ in late time. However, it accelerates very fast from the beginning for large values of ζ . By illustrating the evolutionary trajectories in r-s and r-q planes, we find that our model behaves as an quintessence like for small values of viscous coefficient and a Chaplygin gas like for large values of bulk viscous coefficient at early stage. However, model has close resemblance to that of the Λ CDM cosmology in late time. The Om has positive and negative curvatures for phantom and quintessence models, respectively depending on ζ . Our study shows that the bulk viscosity plays very important role in the expansion history of the universe.

Changes in superior mesenteric artery Doppler waveform during reduction of cardiac stroke volume and hypotension

DEFF Research Database (Denmark)

Perko, M J; Perko, Grazyna; Just, S

1996-01-01

the hypovolemia. Alterations in pV and pulsatility indices were closely related to changes in stroke volume, and a negative correlation was found between diastolic velocities and stroke volume. regression analysis showed no significant relation between variations in velocity parameters and blood pressure. Results...

RAIL TRAFFIC VOLUME ESTIMATION BASED ON WORLD DEVELOPMENT INDICATORS

Directory of Open Access Journals (Sweden)

Luka Lazarević

2015-08-01

Full Text Available European transport policy, defined in the White Paper, supports shift from road to rail and waterborne transport. The hypothesis of the paper is that changes in the economic environment influence rail traffic volume. Therefore, a model for prediction of rail traffic volume applied in different economic contexts could be a valuable tool for the transport planners. The model was built using common Machine Learning techniques that learn from the past experience. In the model preparation, world development indicators defined by the World Bank were used as input parameters.

A method for bubble volume calculating in vertical two-phase flow

International Nuclear Information System (INIS)

Wang, H Y; Dong, F

2009-01-01

The movement of bubble is a basic subject in gas-liquid two-phase flow research. A method for calculating bubble volume which is one of the most important characters in bubble motion research was proposed. A suit of visualized experimental device was designed and set up. Single bubble rising in stagnant liquid in a rectangular tank was studied using the high-speed video system. Bubbles generated by four orifice with different diameter (1mm, 2mm, 3mm, 4mm) were recorded respectively. Sequences of recorded high-speed images were processed by digital image processing method, such as image noise remove, binary image transform, bubble filling, and so on. then, Several parameters could be obtained from the processed image. Bubble area, equivalent diameter, bubble velocity, bubble acceleration are all indispensable in bubble volume calculating. In order to get the force balance equation, forces that work on bubble along vertical direction, including drag force, virtual mass force, buoyancy, gravity and liquid thrust, were analyzed. Finally, the bubble volume formula could be derived from the force balance equation and bubble parameters. Examples were given to shown the computing process and results. Comparison of the bubble volume calculated by geomettic method and the present method have shown the superiority of the proposed method in this paper.

Estimating physiological skin parameters from hyperspectral signatures

Science.gov (United States)

Vyas, Saurabh; Banerjee, Amit; Burlina, Philippe

2013-05-01

We describe an approach for estimating human skin parameters, such as melanosome concentration, collagen concentration, oxygen saturation, and blood volume, using hyperspectral radiometric measurements (signatures) obtained from in vivo skin. We use a computational model based on Kubelka-Munk theory and the Fresnel equations. This model forward maps the skin parameters to a corresponding multiband reflectance spectra. Machine-learning-based regression is used to generate the inverse map, and hence estimate skin parameters from hyperspectral signatures. We test our methods using synthetic and in vivo skin signatures obtained in the visible through the short wave infrared domains from 24 patients of both genders and Caucasian, Asian, and African American ethnicities. Performance validation shows promising results: good agreement with the ground truth and well-established physiological precepts. These methods have potential use in the characterization of skin abnormalities and in minimally-invasive prescreening of malignant skin cancers.

Integral dose and evaluation of irradiated tissue volume

International Nuclear Information System (INIS)

Sivachenko, T.P.; Kalina, V.K.; Belous, A.K.; Gaevskij, V.I.

1984-01-01

Two parameters having potentialities of radiotherapy planning improvement are under consideration. One of these two parameters in an integral dose. An efficiency of application of special tables for integral dose estimation is noted. These tables were developed by the Kiev Physician Improvement Institute and the Cybernetics Institute of the Ukrainian SSR Academy of Science. The meaning of the term of ''irradiated tissue volume'' is specified, and the method of calculation of the irradiated tissue effective mass is considered. It is possible to evaluate with higher accuracy tolerance doses taking into account the irradiated mass

Removal of rare gases from large volume airstreams

International Nuclear Information System (INIS)

Hopke, P.K.; Leong, K.H.; Stukel, J.J.; Lewis, C.; Jebackumar, R.; Illinois Univ., Urbana; Illinois Univ., Urbana

1986-01-01

The cost-effective removal of low levels of rare gases and particularly radon from large volume air flows is a difficult problem. The use of various scrubbing systems using non-conventional fluids has been studied. The parameters for both a packed tower absorber and a gas scrubber have been calculated for a system using perfluorobenzene as the fluid. Based on these parameters, a packed bed tower of conventional proportions is feasible for the removal of >95% of 37 Bq/m 3 of radon from a flow of 4.7 m 3 /second. (author)

MODEL PERUBAHAN VOLUME KERIPIK BUAH SELAMA PROSES PENGGORENGAN SECARA VAKUM [Model for Volume Changes in Fruit Chips during Vacuum Frying

Directory of Open Access Journals (Sweden)

Jamaluddin1*

2011-06-01

Full Text Available Expansion and puffing are specific characteristics of fried products critical for consumer preferences. To obtain expanded and puffed dried products that fit well with consumer acceptance criteria, it is necessary to pay attention to the process conditions which change the raw material characteristics during frying. The important changes include volume and density ratio of the products during frying. Hypothetically, these changes are due to water vaporization and the decrease dry matter in the products. The objective of this research is to develop a mathematical model of volume and density ratio changes for jack fruit during vacuum frying as a function of water and starch content reductions. Samples were vacuum fried at 70–100OC and pressure of 80-90 kPa for 15–60 min. The parameters observed were volume and density as well as water and starch contents of samples before and after vacuum frying. The results showed that the developed model can be used to predict changes in volume and density ratio of jack fruit during vacuum frying.

Design parameters and source terms: Volume 3, Source terms: Revision 0

International Nuclear Information System (INIS)

1987-09-01

The Design Parameters and Source Terms Document was prepared in accordance with DOE request and to provide data for the environmental impact study to be performed in the future for the Deaf Smith County, Texas site for a nuclear waste repository in salt. This document updates a previous unpublished report to the level of the Site Characterization Plan /endash/ Conceptual Design Report, SCP-CDR. The previous unpublished SCC Study identifies the data needs for the Environmental Assessment effort for seven possible salt repository sites

A theoretical approach to the problem of dose-volume constraint estimation and their impact on the dose-volume histogram selection

International Nuclear Information System (INIS)

Schinkel, Colleen; Stavrev, Pavel; Stavreva, Nadia; Fallone, B. Gino

2006-01-01

This paper outlines a theoretical approach to the problem of estimating and choosing dose-volume constraints. Following this approach, a method of choosing dose-volume constraints based on biological criteria is proposed. This method is called ''reverse normal tissue complication probability (NTCP) mapping into dose-volume space'' and may be used as a general guidance to the problem of dose-volume constraint estimation. Dose-volume histograms (DVHs) are randomly simulated, and those resulting in clinically acceptable levels of complication, such as NTCP of 5±0.5%, are selected and averaged producing a mean DVH that is proven to result in the same level of NTCP. The points from the averaged DVH are proposed to serve as physical dose-volume constraints. The population-based critical volume and Lyman NTCP models with parameter sets taken from literature sources were used for the NTCP estimation. The impact of the prescribed value of the maximum dose to the organ, D max , on the averaged DVH and the dose-volume constraint points is investigated. Constraint points for 16 organs are calculated. The impact of the number of constraints to be fulfilled based on the likelihood that a DVH satisfying them will result in an acceptable NTCP is also investigated. It is theoretically proven that the radiation treatment optimization based on physical objective functions can sufficiently well restrict the dose to the organs at risk, resulting in sufficiently low NTCP values through the employment of several appropriate dose-volume constraints. At the same time, the pure physical approach to optimization is self-restrictive due to the preassignment of acceptable NTCP levels thus excluding possible better solutions to the problem