Note: A pulsed laser ion source for linear induction accelerators

NASA Astrophysics Data System (ADS)

Zhang, H.; Zhang, K.; Shen, Y.; Jiang, X.; Dong, P.; Liu, Y.; Wang, Y.; Chen, D.; Pan, H.; Wang, W.; Jiang, W.; Long, J.; Xia, L.; Shi, J.; Zhang, L.; Deng, J.

2015-01-01

We have developed a high-current laser ion source for induction accelerators. A copper target was irradiated by a frequency-quadrupled Nd:YAG laser (266 nm) with relatively low intensities of 108 W/cm2. The laser-produced plasma supplied a large number of Cu+ ions (˜1012 ions/pulse) during several microseconds. Emission spectra of the plasma were observed and the calculated electron temperature was about 1 eV. An induction voltage adder extracted high-current ion beams over 0.5 A/cm2 from a plasma-prefilled gap. The normalized beam emittance measured by a pepper-pot method was smaller than 1 π mm mrad.

A 25kW fiber-coupled diode laser for pumping applications

NASA Astrophysics Data System (ADS)

Malchus, Joerg; Krause, Volker; Koesters, Arnd; Matthews, David G.

2014-03-01

In this paper we report the development of a new fiber-coupled diode laser for pumping applications capable of generating 25 kW with four wavelengths. The delivery fiber has 2.0 mm core diameter and 0.22 NA resulting in a Beam Parameter Product (BPP) of 220 mm mrad. To achieve the specifications mentioned above a novel beam transformation technique has been developed combining two high power laser stacks in one common module. After fast axis collimation and beam reformatting a beam with a BPP of 200 mm mrad x 40 mm mrad in the slow and fast-axis is generated. Based on this architecture a customer-specific pump laser with 25 kW optical output power has been developed, in which two modules are polarization multiplexed for each wavelength (980nm, 1020nm, 1040m and 1060nm). After slow-axis collimation these wavelengths are combined using dense wavelength coupling before focusing onto the fiber endface. This new laser is based on a turn-key platform, allowing straight-forward integration into any pump application. The complete system has a footprint of less than 1.4m² and a height of less than 1.8m. The laser diodes are water cooled, achieve a wall-plug efficiency of up to 60%, and have a proven lifetime of <30,000 hours. The new beam transformation techniques open up prospects for the development of pump sources with more than 100kW of optical output power.

Operation and commissioning of IFMIF (International Fusion Materials Irradiation Facility) LIPAc injector.

PubMed

Okumura, Y; Gobin, R; Knaster, J; Heidinger, R; Ayala, J-M; Bolzon, B; Cara, P; Chauvin, N; Chel, S; Gex, D; Harrault, F; Ichimiya, R; Ihara, A; Ikeda, Y; Kasugai, A; Kikuchi, T; Kitano, T; Komata, M; Kondo, K; Maebara, S; Marqueta, A; O'Hira, S; Perez, M; Phillips, G; Pruneri, G; Sakamoto, K; Scantamburlo, F; Senée, F; Shinto, K; Sugimoto, M; Takahashi, H; Usami, H; Valette, M

2016-02-01

The objective of linear IFMIF prototype accelerator is to demonstrate 125 mA/CW deuterium ion beam acceleration up to 9 MeV. The injector has been developed in CEA Saclay and already demonstrated 140 mA/100 keV deuterium beam [R. Gobin et al., Rev. Sci. Instrum. 85, 02A918 (2014)]. The injector was disassembled and delivered to the International Fusion Energy Research Center in Rokkasho, Japan. After reassembling the injector, commissioning has started in 2014. Up to now, 100 keV/120 mA/CW hydrogen and 100 keV/90 mA/CW deuterium ion beams have been produced stably from a 10 mm diameter extraction aperture with a low beam emittance of 0.21 π mm mrad (rms, normalized). Neutron production by D-D reaction up to 2.4 × 10(9) n/s has been observed in the deuterium operation.

Note: A pulsed laser ion source for linear induction accelerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, H., E-mail: bamboobbu@hotmail.com; School of Physics, Peking University, Beijing 100871; Zhang, K.

2015-01-15

We have developed a high-current laser ion source for induction accelerators. A copper target was irradiated by a frequency-quadrupled Nd:YAG laser (266 nm) with relatively low intensities of 10{sup 8} W/cm{sup 2}. The laser-produced plasma supplied a large number of Cu{sup +} ions (∼10{sup 12} ions/pulse) during several microseconds. Emission spectra of the plasma were observed and the calculated electron temperature was about 1 eV. An induction voltage adder extracted high-current ion beams over 0.5 A/cm{sup 2} from a plasma-prefilled gap. The normalized beam emittance measured by a pepper-pot method was smaller than 1 π mm mrad.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soundy, R.G.; Simpson, J.D.; Ross, H.M.

The absorbed radiation dose that would result from the oral or intravenous administration of SeHCAT (23-(/sup 75/Se)selena-25-homotaurocholate) has been calculated using the MIRD tables and formulas and data from measurements of whole-body distribution and from long-term whole-body counting in rats, mice, and man. When SeHCAT is administered to normal subjects, the gallbladder is the critical organ, receiving 12 mrad (oral dose) or 22 mrad (i.v.) per microcurie. The whole-body dose is 1 mrad/..mu..Ci, whatever the route of administration. In severe hepatic failure the liver might receive 200 mrad/..mu..Ci. The activity likely to be used in routine clinical practice is 10more » ..mu..Ci. Where a whole-body counter is used, an activity of 1 ..mu..Ci has proved adequate. Even at an administered activity of 25 ..mu..Ci, the absorbed dose is small compared with established techniques of investigating the gastrointestinal tract.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soundy, R.G.; Simpson, J.D.; Ross, H.M.

The absorbed radiation dose that would result from the oral or intravenous administration of SeHCAT (23-(75Se)selena-25-homotaurocholate) has been calculated using the MIRD tables and formulas and data from measurements of whole-body distribution and from long-term whole-body counting in rats, mice, and man. When SeHCAT is administered to normal subjects, the gallbladder is the critical organ, receiving 12 mrad (oral dose) or 22 mrad (i.v.) per microcurie. The whole-body dose is 1 mrad/microCi, whatever the route of administration. In severe hepatic failure the liver might receive 200 mrad/microCi. The activity likely to be used in routine clinical practice is 10 microCi.more » Where a whole-body counter is used, an activity of 1 microCi has proved adequate. Even at an administered activity of 25 microCi, the absorbed dose is small compared with established techniques of investigating the gastrointestinal tract.« less

Design of laser afocal zoom expander system

NASA Astrophysics Data System (ADS)

Jiang, Lian; Zeng, Chun-Mei; Hu, Tian-Tian

2018-01-01

Laser afocal zoom expander system due to the beam diameter variable, can be used in the light sheet illumination microscope to observe the samples of different sizes. Based on the principle of afocal zoom system, the laser collimation and beam expander system with a total length of less than 110mm, 6 pieces of spherical lens and a beam expander ratio of 10 is designed by using Zemax software. The system is focused on laser with a wavelength of 532nm, divergence angle of less than 4mrad and incident diameter of 4mm. With the combination of 6 spherical lens, the beam divergence angle is 0.4mrad at the maximum magnification ratio, and the RMS values at different rates are less than λ/4. This design is simple in structure and easy to process and adjust. It has certain practical value.

Particle production of a graphite target system for the intensity frontier

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ding, X.; Kirk, H.; McDonald, K. T.

2015-05-03

A solid graphite target system is considered for an intense muon and/or neutrino source in support of physics at the intensity frontier. We previously optimized the geometric parameters of the beam and target to maximize particle production at low energies by incoming protons with kinetic energy of 6.75 GeV and an rms geometric emittance of 5 mm-mrad using the MARS15(2014) code. In this study, we ran MARS15 with ROOT-based geometry and also considered a mercury-jet target as an upgrade option. The optimization was extended to focused proton beams with transverse emittances from 5 to 50 mm-mrad, showing that the particlemore » production decreases slowly with increasing emittance. We also studied beam-dump configurations to suppress the rate of undesirable high-energy secondary particles in the beam.« less

Wear of a 5 megarad cross-linked polyethylene liner: a 6-year RSA study.

PubMed

Callary, Stuart A; Campbell, David G; Mercer, Graham; Nilsson, Kjell G; Field, John R

2013-07-01

One cross-linked polyethylene (XLPE) liner is manufactured using a lower dose of radiation, 5 Mrad, which may result in less cross-linking. The reported in vivo wear rate of this XLPE liner in patients undergoing THA has varied, and has included some patients in each reported cohort who had greater than 0.1 mm/year of wear, which is an historical threshold for osteolysis. Previous studies have measured wear on plain radiographs, an approach that has limited sensitivity. We therefore measured the amount and direction of wear at 6 years using Radiostereometric analysis (RSA) in patients who had THAs that included a cross-linked polyethylene liner manufactured using 5 Mrad radiation. We prospectively reviewed wear in 30 patients who underwent primary THAs with the same design of cross-linked acetabular liner and a 28-mm articulation. Tantalum markers were inserted during surgery and all patients had RSA radiographic examinations at 1 week, 6 months, 1, 2, and 6 years postoperatively. The mean proximal, two-dimensional (2-D) and three-dimensional (3-D) wear rates calculated between 1 year and 6 years were 0.014, 0.014, and 0.018 mm/per year, respectively. The direction of the head penetration recorded between 1 week and 6 years was in a proximal direction for all patients, proximolateral for 16 of 24 patients, and proximomedial for eight of 24 patients. The proximal, 2-D and 3-D wear of a XLPE liner produced using 5 Mrad of radiation was low but measurable by RSA after 6 years. No patients had proximal 2-D or 3-D wear rates exceeding 0.1 mm/year. Further followup is needed to evaluate the effect of XLPE wear particles on the development of long-term osteolysis.

A bright attosecond x-ray pulse train generation in a double-laser-driven cone target

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, Li-Xiang; Yu, Tong-Pu, E-mail: tongpu@nudt.edu.cn; Shao, Fu-Qiu

By using full three-dimensional particle-in-cell and Monte Carlo simulations, we investigate the generation of a high-brightness attosecond x-ray pulse train in a double-laser-driven cone target. The scheme makes use of two lasers: the first high-intensity laser with a laser peak intensity 1.37 × 10{sup 20 }W/cm{sup 2} irradiates the cone and produces overdense attosecond electron bunches; the second counterpropagating weakly relativistic laser with a laser peak intensity 4.932 × 10{sup 17 }W/cm{sup 2} interacts with the produced electron bunches and a bright x-ray pulse train is generated by Thomson backscattering of the second laser off the attosecond electron bunches. It is shown that the photon fluxmore » rises by 5 times using the cone target as compared with a normal channel. Meanwhile, the x-ray peak brightness increases significantly from 1.4 × 10{sup 21}/(s mm{sup 2} mrad{sup 2} 0.1 keV) to 6.0 × 10{sup 21}/(s mm{sup 2} mrad{sup 2} 0.1 keV), which is much higher than that of the Thomson x-ray source generated from traditional accelerators. We also discuss the influence of the laser and target parameters on the x-ray pulse properties. This compact bright x-ray source may have diverse applications, e.g., the study of electric dynamics and harmonics emission in the atomic scale.« less

Absorbed dose to man from the Se-75 labeled conjugated bile salt SeHCAT: concise communication.

PubMed

Soundy, R G; Simpson, J D; Ross, H M; Merrick, M V

1982-02-01

The absorbed radiation dose that would result from the oral or intravenous administration of SeHCAT (23-[75Se]selena-25-homotaurocholate) has been calculated using the MIRD tables and formulas and data from measurements of whole-body distribution and from long-term whole-body counting in rats, mice, and man. When SeHCAT is administered to normal subjects, the gallbladder is the critical organ, receiving 12 mrad (oral dose) or 22 mrad (i.v.) per microcurie. The whole-body dose is 1 mrad/microCi, whatever the route of administration. In severe hepatic failure the liver might receive 200 mrad/microCi. The activity likely to be used in routine clinical practice is 10 microCi. Where a whole-body counter is used, an activity of 1 microCi has proved adequate. Even at an administered activity of 25 microCi, the absorbed dose is small compared with established techniques of investigating the gastrointestinal tract.

AMBER: a PIC slice code for DARHT

NASA Astrophysics Data System (ADS)

Vay, Jean-Luc; Fawley, William

1999-11-01

The accelerator for the second axis of the Dual Axis Radiographic Hydrodynamic Test (DARHT) facility will produce a 4-kA, 20-MeV, 2-μ s output electron beam with a design goal of less than 1000 π mm-mrad normalized transverse emittance and less than 0.5-mm beam centroid motion. In order to study the beam dynamics throughout the accelerator, we have developed a slice Particle-In-Cell code named AMBER, in which the beam is modeled as a time-steady flow, subject to self, as well as external, electrostatic and magnetostatic fields. The code follows the evolution of a slice of the beam as it propagates through the DARHT accelerator lattice, modeled as an assembly of pipes, solenoids and gaps. In particular, we have paid careful attention to non-paraxial phenomena that can contribute to nonlinear forces and possible emittance growth. We will present the model and the numerical techniques implemented, as well as some test cases and some preliminary results obtained when studying emittance growth during the beam propagation.

A STUDY OF THE MECHANISM OF RADIATION-INDUCED GELATION IN MONOMER-POLYMER MIXTURES. Quarterly Summary Report, August 1, 1961-October 31, 1961

DOE Office of Scientific and Technical Information (OSTI.GOV)

Odian, G.; Bernstein, B.S.; Kelly, J.J.

1961-11-01

Gel contents can be obtained with polyethylene swollen with inhibitor- free allyl acrylate or inhibitor-free allyl methacrylate at a dose of only 0.05 Mrads Using Co/sup 60/ as the radiation source, allyl methacrylate gives higher gel content than allyl acrylate under similar conditions. icant and continues after Co/sup 60/ irradiation has been completed. Monomer desorption after a dose of 1.2 Mrads is less than after 0.05 Mrads, and does not continue after irradiation is stopped. Gel contents can be obtained without prior equilibrium swelling of polymer--monomer mixtures by irradiating the polymer in the presence of the monomer in a nitrogenmore » atmosphere. By irradiating under these conditions with prior equilibrium swelling, gel fractions appear to be higher than those normally obtained. Gel contents of irradiated equilibrium-swollen polyethylene/ allyl acrylate and polyethylene/allyl methacrylate increase with increasing radiation dose from 0.05 to 1.2 Mrads. Gel contents of 1.2 Mrad irradiated polyethyleneallyl methacrylate systems containing various initial amounts of monomer, increase with increasing monomer content. Polypropylene can be radiation crosslinked to give over 40% gel by prior equilibrium swelling with allyl acrylate or allyl methacrylate. (auth)« less

Development of a pepper pot emittance probe and its application for ECR ion beam studies.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kondrashev, S.; Barcikowski, A.; Mustapha, B.

2009-07-21

A pepper pot-scintillator screen system has been developed and used to measure the emittance of DC ion beams extracted from a high-intensity permanent magnet ECR ion source. The system includes a fast beam shutter with a minimum dwell time of 18 ms to reduce the degradation of the CsI(Tl) scintillator by DC ion beam irradiation and a CCD camera with a variable shutter speed in the range of 1 {micro}s-65 s. On-line emittance measurements are performed by an application code developed on a LabVIEW platform. The sensitivity of the device is sufficient to measure the emittance of DC ion beamsmore » with current densities down to about 100 nA/cm{sup 2}. The emittance of all ion species extracted from the ECR ion source and post-accelerated to an energy of 75-90 keV/charge have been measured downstream of the LEBT. As the mass-to-charge ratio of ion species increases, the normalized RMS emittances in both transverse phase planes decrease from 0.5-1.0 {pi} mm mrad for light ions to 0.05-0.09 {pi} mm mrad for highly charged {sup 209}Bi ions. The dependence of the emittance on ion's mass-to-charge ratio follows very well the dependence expected from beam rotation induced by decreasing ECR axial magnetic field. The measured emittance values cannot be explained by only ion beam rotation for all ion species and the contribution to emittance of ion temperature in plasma, non-linear electric fields and non-linear space charge is comparable or even higher than the contribution of ion beam rotation.« less

Simulated electron beam trajectories toward a field ion microscopy specimen

NASA Astrophysics Data System (ADS)

Larson, D. J.; Camus, P. P.; Kelly, T. F.

1993-04-01

This article explores the conditions under which a directed electron beam originating nearly normal to the specimen axis can be made to impact the near-apex region of a field ion microscopy specimen in a high electric field. Electron trajectories were calculated using a modified Runge-Kutta numerical method. The results indicate that an electron beam can be directed to a specimen under typical field ion microscopy conditions using two methods: by varying initial beam tilt (less than 60 mrad) or by translating the initial beam position relative to the specimen apex (less than 5 mm). The net focusing effect of the high electric field on the electron beam can be treated, to first order, as an astigmatism and may be correctable by a post-lens deflection system.

A pulsed electron gun for the Plane Wave Transformer Linac

NASA Astrophysics Data System (ADS)

Mahadevan, S.; Gandhi, M. L.; Nandedkar, R. V.

2003-01-01

A pulsed diode electron gun delivering 500 mA current at 40 kV is described. The gun geometry is optimized using the Electron Trajectory Program EGUN at higher scaling factors by choosing the closest converging starting surface. The effect of an annular gap between cathode and focusing electrode on beam behaviour is compensated by using a suitable focusing electrode. The estimated perveance is 0.065 μperv and the normalized emittance is within 5 π mm mrad. The variation in current density at the cathode has been limited to within 10% across the face of the cathode. Salient features of the pulsed power supply and an insight of its interconnection with the gun are presented. The current measured at the Faraday cup is in agreement with the designed perveance.

Investigations of the emittance and brightness of ion beams from an electron beam ion source of the Dresden EBIS type.

PubMed

Silze, Alexandra; Ritter, Erik; Zschornack, Günter; Schwan, Andreas; Ullmann, Falk

2010-02-01

We have characterized ion beams extracted from the Dresden EBIS-A, a compact room-temperature electron beam ion source (EBIS) with a permanent magnet system for electron beam compression, using a pepper-pot emittance meter. The EBIS-A is the precursor to the Dresden EBIS-SC in which the permanent magnets have been replaced by superconducting solenoids for the use of the source in high-ion-current applications such as heavy-ion cancer therapy. Beam emittance and brightness values were calculated from data sets acquired for a variety of source parameters, in leaky as well as pulsed ion extraction mode. With box shaped pulses of C(4+) ions at an energy of 39 keV root mean square emittances of 1-4 mm mrad and a brightness of 10 nA mm(-2) mrad(-2) were achieved. The results meet the expectations for high quality ion beams generated by an electron beam ion source.

Axicon based conical resonators with high power copper vapor laser.

PubMed

Singh, Bijendra; Subramaniam, V V; Daultabad, S R; Chakraborty, Ashim

2010-07-01

We report for the first time the performance of axicon based conical resonators (ABCRs) in a copper vapor laser, with novel results. The unstable conical resonator comprising of conical mirror (reflecting axicon) with axicon angle approximately pi/18, cone angle approximately 160 degrees, and a convex mirror of 60 cm radius of curvature was effective in reducing the average beam divergence to approximately 0.15 mrad (approximately 25 fold reduction compared to standard multimode plane-plane cavity) with output power of approximately 31 W. Extraction efficiency of approximately 50%-60% and beam divergence of <1 mrad was achieved in other stable ABCR configurations using flat and concave mirrors with the axicon. This is a significant improvement compared to 4-5 mrad normally observed in conventional stable resonators in copper vapor lasers. The conical resonators with copper vapor laser provide high misalignment tolerance beta approximately 4-5 mrad where beta is the tilt angle of the conical mirror from optimum position responsible for approximately 20% decline in laser power. The depth of focus d was approximately three times larger in case of conical resonator as compared to that of standard spherical unstable resonator under similar beam divergence and focusing conditions.

Numerical modelling of the CEBAF electron gun with EGUN

DOE Office of Scientific and Technical Information (OSTI.GOV)

Philippe Liger; Geoffrey Krafft

1990-09-10

The electron source used in the injector for the CEBAF accelerator is a Hermosa electron gun with a 2 mm diameter cathode and a control electrode. It produces a 100 keV electron beam to be focused on the first of two apertures which comprise an emittance filter. A normalized emittance of less than {pi} mm mrad at 1.2 mA is set by the requirements of the final beam from the CEBAF linac, since downstream of the filter, a system of two choppers and a third aperture removes 5/6 of the current. In addition, for RF test purposes a higher currentmore » of about 5 mA is needed, possibly at higher emittance. This paper presents a way of calculating the characteristics of the CEBAF electron gun with the gun design code EGUN, and the accuracy of the results is discussed. The transverse shape of the beam delivered by the gun has been observed, and its current measured. A halo around the beam has been seen, and the calculations can reproduce this effect.« less

Photon excitation enabled large aperture space-charge-controlled potassium tantalate niobate (KTN) beam deflector

NASA Astrophysics Data System (ADS)

Zhu, Wenbin; Chao, Ju-Hung; Chen, Chang-Jiang; Shang, Annan; Lee, Yun Goo; Yin, Shizhuo; Dubinskii, Mark; Hoffman, Robert C.

2018-03-01

To overcome the depth limitation of the space-charge-controlled (SCC) potassium tantalate niobate (KTN) deflectors, we report in this paper a method of increasing the aperture of SCC-KTN deflectors by harnessing the physical mechanism of blue light photon excitation. The experimental results show that the deflection angle can be increased from 0.7 mrad without the blue light excitation to 2.5 mrad with the blue light excitation at a penetration depth of 5 mm under the same external applied voltage, which is consistent with the theoretical analysis. This represents a substantial increase in the deflection angle at a much deeper penetration depth, which can be very useful for applications such as high speed 3D printings and displays.

Short Pulse High Brightness X-ray Production with the PLEIADES Thomson Scattering Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, S G; Barty, C P J; Betts, S M

2003-07-01

We describe PLEIADES, a compact, tunable, high-brightness, ultra-short pulse, Thomson x-ray source. The peak brightness of the source is expected to exceed 10{sup 20} photons/s/0.1% bandwidth/mm{sup 2}/mrad{sup 2}. Initial results are reported and compared to theoretical calculations.

High-power direct diode laser output by spectral beam combining

NASA Astrophysics Data System (ADS)

Tan, Hao; Meng, Huicheng; Ruan, Xu; Du, Weichuan; Wang, Zhao

2018-03-01

We demonstrate a spectral beam combining scheme based on multiple mini-bar stacks, which have more diode laser combining elements, to increase the combined diode laser power and realize equal beam quality in both the fast and slow axes. A spectral beam combining diode laser output of 1130 W is achieved with an operating current of 75 A. When a 9.6 X de-magnifying telescope is introduced between the output mirror and the diffraction grating, to restrain cross-talk among diode laser emitters, a 710 W spectral beam combining diode laser output is achieved at the operating current of 70 A, and the beam quality on the fast and slow axes of the combined beam is about 7.5 mm mrad and 7.3 mm mrad respectively. The power reduction is caused by the existence of a couple resonator between the rear facet of the diode laser and the fast axis collimation lens, and it should be eliminated by using diode laser chips with higher front facet transmission efficiency and a fast axis collimation lens with lower residual reflectivity.

RF Couplers for Normal-Conducting Photoinjector of High-Power CW FEL

NASA Astrophysics Data System (ADS)

Kurennoy, Sergey; Schrage, Dale; Wood, Richard; Schultheiss, Tom; Rathke, John; Young, Lloyd

2004-05-01

A high-current emittance-compensated RF photoinjector is a key enabling technology for a high-power CW FEL. A preliminary design of a normal-conducting, 2.5-cell pi-mode, 700-MHz CW RF photoinjector that will be build for demonstration purposes, is completed. This photoinjector will be capable of accelerating a 100-mA electron beam (3 nC per bunch at 35 MHz bunch repetition rate) to 2.7 MeV while providing an emittance below 7 mm-mrad at the wiggler. More than 1 MW of RF power will be fed into the photoinjector cavity through two ridge-loaded tapered waveguides. The waveguides are coupled to the cavity by "dog-bone" irises cut in a thick wall. Due to CW operation of the photoinjector, the cooling of the coupler irises is a rather challenging thermal management project. This paper presents results of a detailed electromagnetic modeling of the coupler-cavity system, which has been performed to select the coupler design that minimizes the iris heating due to RF power loss in its walls.

Design of a side coupled standing wave accelerating tube for NSTRI e-Linac

NASA Astrophysics Data System (ADS)

Zarei, S.; Abbasi Davani, F.; Lamehi Rachti, M.; Ghasemi, F.

2017-09-01

The design and construction of a 6 MeV electron linear accelerator (e-Linac) was defined in the Institute of Nuclear Science and Technology (NSTRI) for cargo inspection and medical applications. For this accelerator, a side coupled standing wave tube resonant at a frequency of 2998.5 MHZ in π/2 mode was selected. In this article, the authors provide a step-by-step explanation of the process of the design for this tube. The design and simulation of the accelerating and coupling cavities were carried out in five steps; (1) separate design of the accelerating and coupling cavities, (2) design of the coupling aperture between the cavities, (3) design of the entire structure for resonance at the nominal frequency, (4) design of the buncher, and (5) design of the power coupling port. At all design stages, in addition to finding the dimensions of the cavity, the impact of construction tolerances and simulation errors on the electromagnetic parameters were investigated. The values obtained for the coupling coefficient, coupling constant, quality factor and capture efficiency are 2.11, 0.011, 16203 and 36%, respectively. The results of beam dynamics study of the simulated tube in ASTRA have yielded a value of 5.14 π-mm-mrad for the horizontal emittance, 5.06 π-mm-mrad for the vertical emittance, 1.17 mm for the horizontal beam size, 1.16 mm for the vertical beam size and 1090 keV for the energy spread of the output beam.

Proceedings of the 1993 Particle Accelerator Conference Held in Washington, DC on May 17-20, 1993. Volume 3

DTIC Science & Technology

1993-05-20

mm-mrad 10 mm-md I. INTRODUCTION Higher -order modes (HOMs) of the SR single cell cavityThe 20-MeV linac beam at the Argonne Chemistry are studied by...energy proton storage rings: RHIC and the SSC. I. INTRODUCTION We have proposed to build spin rotators with two k transverse wigglers of many poles...integral of gauge field; beam Is always polarized, the magnetic potential flux line of (4) edot quantization of path integral in sate sae bunch spin are

Radiation measurements aboard the fourth Gemini flight.

PubMed

Janni, J F; Schneider, M F

1967-01-01

Two special tissue-equivalent ionization chambers and 5 highly sensitive passive dosimetry packages were flown aboard the recent Gemini 4 flight for the purpose of obtaining precise values of instantaneous dose rate, accumulated dose. and shielding effectiveness. This experiment marked the first time that well-defined tissue dose and radiation survey measurements have been carried out in manned spaceflight operations. Since all measurements were accomplished under normal spacecraft environmental conditions, the biological dose resulted primarily from trapped inner Van Allen Belt radiation encountered by the spacecraft in the South Atlantic Anomaly. The experiment determined the particle type, ionizing and penetrating power, and variation with time and position within the Gemini spacecraft. Measured dose rates ranged from 100 mrad/hr for passes penetrating deeply into the South Atlantic Anomaly to less than 0.1 mrad/hr from lower latitude cosmic radiation. The accumulated tissue dose measured by the active ionization chambers, shielded by 0.4 gm/cm2 for the 4-day mission, was 82 mrad. Since the 5 passive dosimetry packages were each located in different positions within the spacecraft, the total mission surface dose measured by these detectors varied from 73 to 27 mrad, depending upon location and shielding. The particles within the spacecraft were recorded in nuclear emulsion, which established that over 90% of the tissue dose was attributable to penetrating protons. This experiment indicates that the radiation environment under shielded conditions at Gemini altitudes was not hazardous.

A concept for canceling the leakage field inside the stored beam chamber of a septum magnet

NASA Astrophysics Data System (ADS)

Abliz, M.; Jaski, M.; Xiao, A.; Jain, A.; Wienands, U.; Cease, H.; Borland, M.; Decker, G.; Kerby, J.

2018-04-01

The Advanced Photon Source (APS) is planning to upgrade its storage ring from a double-bend achromat to a multi-bend achromat lattice as part of the APS Upgrade Project (APS-U). A swap-out injection scheme is planned for the APS-U in order to keep the beam current constant and to reduce the dynamic aperture requirements. The injection scheme, combined with the constraints in the booster to storage ring transfer region of the APS-U, results in requiring a septum magnet which deflects the injected 6 GeV electron beam by 89 mrad, while not appreciably disturbing the stored beam. The proposed magnet is straight; however, it is rotated in yaw, roll, and pitch from the stored beam chamber to meet the on-axis swap-out injection requirements for the APS-U lattice. The concept utilizes cancellation of the leakage field inside the 8 mm x 6 mm super-ellipsoidal stored beam chamber. As a result, the horizontal deflection angle of the 6 GeV stored beam is reduced to less than 1 μrad with only a 2-mm-thick septum separating the stored beam and the 1.06 T field seen by the injected beam. This design also helps to minimize the integrated skew quadrupole and normal sextupole fields inside the stored beam chamber.

Deuteron injector for Peking University Neutron Imaging Facility projecta)

NASA Astrophysics Data System (ADS)

Ren, H. T.; Peng, S. X.; Lu, P. N.; Zhou, Q. F.; Yuan, Z. X.; Zhao, J.; Zhang, M.; Song, Z. Z.; Yu, J. X.; Guo, Z. Y.; Chen, J. E.

2012-02-01

The deuteron injector developed for the PKUNIFTY (Peking University Neutron Imaging Facility) has been installed and commissioned at Peking University (PKU). The injector system must transfer 50 keV 50 mA of D+ ion beam to the entrance of the 2 MeV radio frequency quadrupole (RFQ) with 10% duty factor (1 ms, 100 Hz). A compact 2.45 GHz permanent magnet electron cyclotron resonance (PMECR) ion source and a 1.36 m long low energy beam transport (LEBT) line using two solenoids was developed as the deuteron injector. A ϕ5 mm four-quadrant diaphragm was used to simulate the entrance of RFQ electrodes. The beam parameters are measured after this core with an emittance measurement unit (EMU) and a bending magnet for ion fraction analysis at the end of injector. During the commissioning, 77 mA of total deuteron beam was extracted from PMECR and 56 mA of pure D+ beam that passed through the ϕ5 mm four-quadrant diaphragm was obtained at the position of RFQ entrance with the measured normalized rms emittance 0.12-0.16π mm mrad. Ion species analysis results show that the deuteron fraction is as high as 99.5%. All of the parameters satisfy PKUNIFTY's requirements. In this paper, we will describe the deuteron injector design and report the commissioning results as well as the initial operation.

Free-space wavelength-multiplexed optical scanner demonstration.

PubMed

Yaqoob, Zahid; Riza, Nabeel A

2002-09-10

Experimental demonstration of a no-moving-parts free-space wavelength-multiplexed optical scanner (W-MOS) is presented. With fast tunable lasers or optical filters and planar wavelength dispersive elements such as diffraction gratings, this microsecond-speed scanner enables large several-centimeter apertures for subdegree angular scans. The proposed W-MOS design incorporates a unique optical amplifier and variable optical attenuator combination that enables the calibration and modulation of the scanner response, leading to any desired scanned laser beam power shaping. The experimental setup uses a tunable laser centered at 1560 nm and a 600-grooves/mm blazed reflection grating to accomplish an angular scan of 12.92 degrees as the source is tuned over an 80-nm bandwidth. The values for calculated maximum optical beam divergance, required wavelength resolution, beam-pointing accuracy, and measured scanner insertion loss are 1.076 mrad, 0.172 nm, 0.06 mrad, and 4.88 dB, respectively.

High-power broad-area diode lasers optimized for fiber laser pumping

NASA Astrophysics Data System (ADS)

Gilly, J.; Friedmann, P.; Kissel, H.; Biesenbach, J.; Kelemen, M. T.

2012-03-01

In diode laser applications for fibre laser pumping and materials processing high brightness becomes more and more important. At the moment fibre coupled modules benefit from continuous improvement of Broad-Area (BA) lasers on the chip level regarding output power, efficiency and far-field characteristics. To achieve high brightness not only the output power must be increased, but also the far field angles have to be maintained or even decreased because brightness is proportional to output power divided by beam quality. Typically fast axis far fields show mostly a current independent behaviour, for broad-area lasers far-fields in the slow axis suffer from a strong current and temperature dependence, limiting the brightness. These limitations can be overcomed by carefully optimizing epitaxy-design and processing and also thermal management of the mounted device. The easiest way to achieve a good thermal management of BA-Lasers is to increase the resonator length while simultaneously decreasing internal losses of the epitaxy structure. To fulfill these issues, we have realized MBE grown InGaAs/AlGaAs broad-area with resonator lengths between 4mm and 6mm emitting at 976nm. To evaluate the brightness of these broad-area lasers single emitters have been mounted p-side down. Near- and far-fields have been carefully investigated. For a 4mm long broad-area laser with around 100μm emission width a beam parameter product of less than 3.5 mm x mrad has been achieved at 10W with a slope efficiency of more than 1.1W/A and a maximum wall-plug efficiency of more than 67%. For a device with 6mm resonator length we have reached a BPP of less than 3.5mm x mrad at 14W in slow axis direction which results in a brightness around 130MW/cm2 sr, which is to our knowledge the highest brightness reported so far for BA-lasers.

Refined beam measurements on the SNS H- injector

NASA Astrophysics Data System (ADS)

Han, B. X.; Welton, R. F.; Murray, S. N.; Pennisi, T. R.; Santana, M.; Stinson, C. M.; Stockli, M. P.

2017-08-01

The H- injector for the SNS RFQ accelerator consists of an RF-driven, Cs-enhanced H- ion source and a compact, two-lens electrostatic LEBT. The LEBT output and the RFQ input beam current are measured by deflecting the beam on to an annular plate at the RFQ entrance. Our method and procedure have recently been refined to improve the measurement reliability and accuracy. The new measurements suggest that earlier measurements tended to underestimate the currents by 0-2 mA, but essentially confirm H- beam currents of 50-60 mA being injected into the RFQ. Emittance measurements conducted on a test stand featuring essentially the same H- injector setup show that the normalized rms emittance with 0.5% threshold (99% inclusion of the total beam) is in a range of 0.25-0.4 mm.mrad for a 50-60 mA beam. The RFQ output current is monitored with a BCM toroid. Measurements as well as simulations with the PARMTEQ code indicate an underperforming transmission of the RFQ since around 2012.

Spatio-temporal shaping of photocathode laser pulses for linear electron accelerators

NASA Astrophysics Data System (ADS)

Mironov, S. Yu; Andrianov, A. V.; Gacheva, E. I.; Zelenogorskii, V. V.; Potemkin, A. K.; Khazanov, E. A.; Boonpornprasert, P.; Gross, M.; Good, J.; Isaev, I.; Kalantaryan, D.; Kozak, T.; Krasilnikov, M.; Qian, H.; Li, X.; Lishilin, O.; Melkumyan, D.; Oppelt, A.; Renier, Y.; Rublack, T.; Felber, M.; Huck, H.; Chen, Y.; Stephan, F.

2017-10-01

Methods for the spatio-temporal shaping of photocathode laser pulses for generating high brightness electron beams in modern linear accelerators are discussed. The possibility of forming triangular laser pulses and quasi-ellipsoidal structures is analyzed. The proposed setup for generating shaped laser pulses was realised at the Institute of Applied Physics (IAP) of the Russian Academy of Sciences (RAS). Currently, a prototype of the pulse-shaping laser system is installed at the Photo Injector Test facility at DESY, Zeuthen site (PITZ). Preliminary experiments on electron beam generation using ultraviolet laser pulses from this system were carried out at PITZ, in which electron bunches with a 0.5-nC charge and a transverse normalized emittance of 1.1 mm mrad were obtained. A new scheme for the three-dimensional shaping of laser beams using a volume Bragg profiled grating is proposed at IAP RAS and is currently being tested for further electron beam generation experiments at the PITZ photoinjector.

Ultra-low-loss tapered optical fibers with minimal lengths

NASA Astrophysics Data System (ADS)

Nagai, Ryutaro; Aoki, Takao

2014-11-01

We design and fabricate ultra-low-loss tapered optical fibers (TOFs) with minimal lengths. We first optimize variations of the torch scan length using the flame-brush method for fabricating TOFs with taper angles that satisfy the adiabaticity criteria. We accordingly fabricate TOFs with optimal shapes and compare their transmission to TOFs with a constant taper angle and TOFs with an exponential shape. The highest transmission measured for TOFs with an optimal shape is in excess of 99.7 % with a total TOF length of only 23 mm, whereas TOFs with a constant taper angle of 2 mrad reach 99.6 % transmission for a 63 mm TOF length.

A high speed CCSDS encoder for space applications

NASA Technical Reports Server (NTRS)

Whitaker, S.; Liu, K.

1990-01-01

This paper reports a VLSI implementation of the CCSDS standard Reed Solomon encoder circuit for the Space Station. The 1.0 micron double metal CMOS chip is 5.9 mm by 3.6 mm, contains 48,000 transistors, operates at a sustained data rate of 320 Mbits/s, and executes 2,560 Mops. The chip features a pin selectable interleave depth of 1 to 8. Block lengths of up to 255 bytes, as well as shortened codes, are supported. The control circuitry uses register cells which are immune to Single Event Upset. In addition, the CMOS process used is reported to be tolerant of over 1 Mrad total dose radiation.

Deployment of a Secondary Concentrator to Increase the Intercept Factor of a Dish with Large Slope Errors

NASA Technical Reports Server (NTRS)

Ortabasi, U.; Gray, E.; Ogallagher, J. J.

1984-01-01

The testing of a hyperbolic trumpet non-imaging secondary concentrator with a parabolic dish having slope errors of about 10 mrad is reported. The trumpet, which has a concentration ratio of 2.1, increased the flux through a 141-mm focal aperture by 72%, with an efficiency of 96%, thus demonstrating its potential for use in tandem with cheap dishes having relatively large slope errors.

Theory of topological insulator waveguides: polarization control and the enhancement of the magneto-electric effect

NASA Astrophysics Data System (ADS)

Crosse, J. A.

2017-02-01

Topological insulators subject to a time-reversal-symmetry-breaking perturbation are predicted to display a magneto-electric effect that causes the electric and magnetic induction fields to mix at the material’s surface. This effect induces polarization rotations of between ≈1-10 mrad per interface in an incident plane-polarized electromagnetic wave normal to a multilayered structure. Here we show, theoretically and numerically, that by using a waveguide geometry with a topological insulator guide layer and magneto-dielectric cladding it is possible to achieve rotations of ≈100 mrad and generate an elliptical polarization with only a three-layered structure. This geometry is beneficial, not only as a way to enhance the magneto-electric effect, rendering it easier to observe, but also as a method for controlling the polarization of electromagnetic radiation.

Radiation damage and recovery properties of common plastics PEN (Polyethylene Naphthalate) and PET (Polyethylene Terephthalate) using a 137Cs gamma ray source up to 1.4 Mrad and 14 Mrad

NASA Astrophysics Data System (ADS)

Wetzel, J.; Tiras, E.; Bilki, B.; Onel, Y.; Winn, D.

2016-08-01

Polyethylene naphthalate (PEN) and polyethylene teraphthalate (PET) are cheap and common polyester plastics used throughout the world in the manufacturing of bottled drinks, containers for foodstuffs, and fibers used in clothing. These plastics are also known organic scintillators with very good scintillation properties. As particle physics experiments increase in energy and particle flux density, so does radiation exposure to detector materials. It is therefore important that scintillators be tested for radiation tolerance at these generally unheard of doses. We tested samples of PEN and PET using laser stimulated emission on separate tiles exposed to 1 Mrad and 10 Mrad gamma rays with a 137Cs source. PEN exposed to 1.4 Mrad and 14 Mrad emit 71.4% and 46.7% of the light of an undamaged tile, respectively, and maximally recover to 85.9% and 79.5% after 5 and 9 days, respectively. PET exposed to 1.4 Mrad and 14 Mrad emit 35.0% and 12.2% light, respectively, and maximally recover to 93.5% and 80.0% after 22 and 60 days, respectively.

Lasers for industrial production processing: tailored tools with increasing flexibility

NASA Astrophysics Data System (ADS)

Rath, Wolfram

2012-03-01

High-power fiber lasers are the newest generation of diode-pumped solid-state lasers. Due to their all-fiber design they are compact, efficient and robust. Rofin's Fiber lasers are available with highest beam qualities but the use of different process fiber core sizes enables the user additionally to adapt the beam quality, focus size and Rayleigh length to his requirements for best processing results. Multi-mode fibers from 50μm to 600μm with corresponding beam qualities of 2.5 mm.mrad to 25 mm.mrad are typically used. The integrated beam switching modules can make the laser power available to 4 different manufacturing systems or can share the power to two processing heads for parallel processing. Also CO2 Slab lasers combine high power with either "single-mode" beam quality or higher order modes. The wellestablished technique is in use for a large number of industrial applications, processing either metals or non-metallic materials. For many of these applications CO2 lasers remain the best choice of possible laser sources either driven by the specific requirements of the application or because of the cost structure of the application. The actual technical properties of these lasers will be presented including an overview over the wavelength driven differences of application results, examples of current industrial practice as cutting, welding, surface processing including the flexible use of scanners and classical optics processing heads.

Theoretical investigation of the ultra-intense laser interaction with plasma mirrors in radiation pressure dominant regime

NASA Astrophysics Data System (ADS)

Sonia, Krishna Kumar; Maheshwari, K. P.; Jaiman, N. K.

2017-05-01

At laser intensity in the range ~ 1022 -1023W/cm2, the radiation pressure starts to play a key role in the interaction of an intense electromagnetic wave with a dense plasma foil. Depending upon the incident laser intensity, polarization of the incident beam and also on the density of the thin plasma layer the mirror motion may be assumed to be uniform, accelerated, or oscillatory. A solid dense plasma slab, accelerated in the radiation pressure dominant (RPD) regime, can efficiently reflect a counter-propagating relativistically strong source pulse consisting of up-shifted frequency and high harmonics. In this RPD regime we present our numerical results for the frequency and brightness of the reflected radiation from a uniformly moving plasma mirror. Our numerical results show that for the appropriate laser and plasma parameters in the case 2γ < {({n}e{λ }s3)}1/6 there are approximately 8.03 × 1042 photons / (mm2 - mrad2 - sec.-0.1% bandwidth) in the energy range ~ 10keV. In the case when 2γ > {({n}e{λ }s3)}1/6 for the same parameters and ad = 300, λd = 0.8 μm, the brightness is found to be 3.27 × 1034 photons / (mm2 - mrad2 - sec. - 0.1% bandwidth) in the energy range ~100 keV.

Achromatic nested Kirkpatrick–Baez mirror optics for hard X-ray nanofocusing

PubMed Central

Liu, Wenjun; Ice, Gene E.; Assoufid, Lahsen; Liu, Chian; Shi, Bing; Khachatryan, Ruben; Qian, Jun; Zschack, Paul; Tischler, Jonathan Z.; Choi, J.-Y.

2011-01-01

The first test of nanoscale-focusing Kirkpatrick–Baez (KB) mirrors in the nested (or Montel) configuration used at a hard X-ray synchrotron beamline is reported. The two mirrors are both 40 mm long and coated with Pt to produce a focal length of 60 mm at 3 mrad incident angle, and collect up to a 120 µm by 120 µm incident X-ray beam with maximum angular acceptance of 2 mrad and a broad bandwidth of energies up to 30 keV. In an initial test a focal spot of about 150 nm in both horizontal and vertical directions was achieved with either polychromatic or monochromatic beam. The nested mirror geometry, with two mirrors mounted side-by-side and perpendicular to each other, is significantly more compact and provides higher demagnification than the traditional sequential KB mirror arrangement. Ultimately, nested mirrors can focus larger divergence to improve the diffraction limit of achromatic optics. A major challenge with the fabrication of the required mirrors is the need for near-perfect mirror surfaces near the edge of at least one of the mirrors. Special polishing procedures and surface profile coating were used to preserve the mirror surface quality at the reflecting edge. Further developments aimed at achieving diffraction-limited focusing below 50 nm are underway. PMID:21685674

Experimental study of a high intensity radio-frequency cooler

NASA Astrophysics Data System (ADS)

Boussaid, Ramzi; Ban, G.; Cam, J. F.

2015-07-01

Within the framework of the DESIR/SPIRAL-2 project, a radio-frequency quadrupole cooler named SHIRaC has been studied. SHIRaC is a key device of SPIRAL-2, designed to enhance the beam quality required by DESIR. The preliminary study and development of this device has been carried out at Laboratoire de Physique Corpusculaire de CAEN (LPC Caen), France. The goal of this paper is to present the experimental studies conducted on a SHIRaC prototype. The main peculiarity of this cooler is its efficient handling and cooling of ion beams with currents going up as high as 1 μ A which has never before been achieved in any of the previous coolers. Much effort has been made lately into these studies for development of appropriate optics, vacuum and rf systems which allow cooling of beams of large emittance (˜80 π mm mrad ) and high current. The dependencies of SHIRaC's transmission and the cooled beam parameters in terms of geometrical transverse emittance and the longitudinal energy spread have also been discussed. Investigation of beam purity at optimum cooling condition has also been done. Results from the experiments indicate that an emittance reduction of less than 2.5 π mm mrad and a longitudinal energy spread reduction of less than 4 eV are obtained with more than 70% of ion transmission. The emittance is at expected values whereas the energy spread is not.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Antipov, Sergey A.; Didenko, Alexander; Lebedev, Valeri

We present a design of a stripline kicker for Integrable Optics Test Accelerator (IOTA). For its experimental program IOTA needs two full-aperture kickers, capable to create an arbitrary controllable kick in 2D. For that reason their strengths are variable in a wide range of amplitudes up to 16 mrad, and the pulse length 100 ns is less than a revolution period for electrons. In addition, the kicker should have a physical aperture of 40 mm for a proposed operation with proton beam, and an outer size of 70 mm to fit inside existing quadrupole magnets to save space in themore » ring. Computer simulations using CST Microwave Studio show high field uniformity and wave impedance close to 50 {\\Omega}.« less

Ultra-high brightness wavelength-stabilized kW-class fiber coupled diode laser

NASA Astrophysics Data System (ADS)

Huang, Robin K.; Chann, Bien; Glenn, John D.

2011-03-01

TeraDiode has produced a fiber-coupled direct diode laser with a power level of 1,040 W from a 200 μm core diameter, 0.18 numerical aperture (NA) output fiber at a single center wavelength. This was achieved with a novel beam combining and shaping technique using COTS diode lasers. The fiber-coupled output corresponds to a Beam Parameter Product (BPP) of 18 mm-mrad and is the lowest BPP kW-class direct diode laser yet reported. The laser has been used to demonstrate laser cutting and welding of steel sheet metal up to 6.65 mm thick. Further advances of these ultra-bright lasers are also projected.

Millimeter wave coherent synchrotron radiation in a compact electron storage ring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murphy, J.B.; Blum, E.; Heese, R.

1998-01-01

Installation of a 2,856 MHz RF system into the XLS compact electron storage ring would allow the generation of millimeter wave coherent synchrotron radiation. Operating at 150 MeV, one could produce bunches containing on the order of 2 {times} 10{sup 7} electrons with a bunch length {sigma}{sub L0} = 0.3 mm, resulting in coherent emission at wavelengths above 0.8 mm. The characteristics of the source and the emitted radiation are discussed. In the case of 100 mrad horizontal collection angle, the average power radiated in the wavelength band 1 mm {le} {lambda} {le} 2 mm is 0.3 mW for singlemore » bunch operation and 24 mW for 80 bunch operation. The peak power in a single pulse of a few picosecond duration is on the order of one watt. By reducing the momentum compaction, the bunch length could be reduced to {sigma}{sub L0} = 0.15 mm, resulting in coherent synchrotron radiation down to 500 {micro}m.« less

Theory of topological insulator waveguides: polarization control and the enhancement of the magneto-electric effect

PubMed Central

Crosse, J. A.

2017-01-01

Topological insulators subject to a time-reversal-symmetry-breaking perturbation are predicted to display a magneto-electric effect that causes the electric and magnetic induction fields to mix at the material’s surface. This effect induces polarization rotations of between ≈1–10 mrad per interface in an incident plane-polarized electromagnetic wave normal to a multilayered structure. Here we show, theoretically and numerically, that by using a waveguide geometry with a topological insulator guide layer and magneto-dielectric cladding it is possible to achieve rotations of ≈100 mrad and generate an elliptical polarization with only a three-layered structure. This geometry is beneficial, not only as a way to enhance the magneto-electric effect, rendering it easier to observe, but also as a method for controlling the polarization of electromagnetic radiation. PMID:28220875

Advanced Laser Technologies for High-brightness Photocathode Electron Gun

NASA Astrophysics Data System (ADS)

Tomizawa, Hiromitsu

A laser-excited photocathode RF gun is one of the most reliable high-brightness electron beam sources for XFELs. Several 3D laser shaping methods have been developed as ideal photocathode illumination sources at SPring-8 since 2001. To suppress the emittance growth caused by nonlinear space-charge forces, the 3D cylindrical UV-pulse was optimized spatially as a flattop and temporally as squarely stacked chirped pulses. This shaping system is a serial combination of a deformable mirror that adaptively shapes the spatial profile with a genetic algorithm and a UV-pulse stacker that consists of four birefringent α-BBO crystal rods for temporal shaping. Using this 3D-shaped pulse, a normalized emittance of 1.4 π mm mrad was obtained in 2006. Utilizing laser's Z-polarization, Schottky-effect-gated photocathode gun was proposed in 2006. The cathode work functions are reduced by a laser-induced Schottky effect. As a result of focusing a radially polarized laser pulse with a hollow lens in vacuum, the Z-field (Z-polarization) is generated at the cathode.

Intrinsic beam emittance of laser-accelerated electrons measured by x-ray spectroscopic imaging.

PubMed

Golovin, G; Banerjee, S; Liu, C; Chen, S; Zhang, J; Zhao, B; Zhang, P; Veale, M; Wilson, M; Seller, P; Umstadter, D

2016-04-19

The recent combination of ultra-intense lasers and laser-accelerated electron beams is enabling the development of a new generation of compact x-ray light sources, the coherence of which depends directly on electron beam emittance. Although the emittance of accelerated electron beams can be low, it can grow due to the effects of space charge during free-space propagation. Direct experimental measurement of this important property is complicated by micron-scale beam sizes, and the presence of intense fields at the location where space charge acts. Reported here is a novel, non-destructive, single-shot method that overcame this problem. It employed an intense laser probe pulse, and spectroscopic imaging of the inverse-Compton scattered x-rays, allowing measurement of an ultra-low value for the normalized transverse emittance, 0.15 (±0.06) π mm mrad, as well as study of its subsequent growth upon exiting the accelerator. The technique and results are critical for designing multi-stage laser-wakefield accelerators, and generating high-brightness, spatially coherent x-rays.

Design simulations for a small emittance 2.7-cell photo-cathode rf-gun in jector

NASA Astrophysics Data System (ADS)

Yongzhang, Huang

1997-05-01

In order to produce the electron bunch with small emittance which is the key issue in the so-called SASE studies, the design studies on a two-and-half cell photocathode rf-gun has been conducted. The rf gun injector is optimized by using the code of Par mela. As a main result, the optimum is found to be a 2.7-cell cavity. The geometry and the coupling scheme of the requested cavity is studied in more detail with the codes of Mafia and Superfish. The beam iris of each cells is enlarged in order to wide n the mode separations. For the purpose of cancelling the influence of the coupling iris upon the field symmetry, the so-called symmetrical double-side input coupler is studied. The coupler will be assembled to the second cell and the critical matchin g has been achieved in the Mafia-T3 simulation. With this cavity, the final normalized rms emittance reaches the value of 0.81πmm-mrad at a charge of 1nC in the Parmela simulation.

Intrinsic beam emittance of laser-accelerated electrons measured by x-ray spectroscopic imaging

DOE PAGES

Golovin, G.; Banerjee, S.; Liu, C.; ...

2016-04-19

Here, the recent combination of ultra-intense lasers and laser-accelerated electron beams is enabling the development of a new generation of compact x-ray light sources, the coherence of which depends directly on electron beam emittance. Although the emittance of accelerated electron beams can be low, it can grow due to the effects of space charge during free-space propagation. Direct experimental measurement of this important property is complicated by micron-scale beam sizes, and the presence of intense fields at the location where space charge acts. Reported here is a novel, non-destructive, single-shot method that overcame this problem. It employed an intense lasermore » probe pulse, and spectroscopic imaging of the inverse-Compton scattered x-rays, allowing measurement of an ultra-low value for the normalized transverse emittance, 0.15 (±0.06) π mm mrad, as well as study of its subsequent growth upon exiting the accelerator. The technique and results are critical for designing multi-stage laser-wakefield accelerators, and generating high-brightness, spatially coherent x-rays.« less

Design and beam transport simulations of a multistage collector for the Israeli EA-FEM

NASA Astrophysics Data System (ADS)

Tecimer, M.; Canter, M.; Efimov, S.; Gover, A.; Sokolowski, J.

2001-12-01

A four stage asymmetric type depressed collector has been designed for the Israeli mm-wave FEM that is driven by a 1.4 MeV, 1.5 A electron beam. After leaving the interaction section the spent beam has an energy spread of 120 keV and 75 π mm mrad normalized beam emittance. Simulations of the beam transport system from the undulator exit through the decelerator tube into the collector have been carried out using EGUN and GPT codes. The latter has also been employed to study trajectories of the primary and scattered particles within the collector, optimizing the asymmetrical collector geometry and the electrode potentials at the presence of a deflecting magnetic field. The estimated overall system and collector efficiencies reach 50% and 70%, respectively, with a beam recovery of 99.6%. The design is aimed to attain millisecond long pulse operation and subsequently 1 kW average power. Simulation results are implemented in a mechanical design that leads to a simple, cost efficient assembly eliminating ceramic insulator rings between collector stages and the associated brazing in the manufacturing process. Instead, each copper plate is supported by insulating posts and freely displaceable within the vacuum chamber. We report on the simulation results of the beam transport and recovery systems and on the mechanical aspects of the multistage collector design.

Long-pulse beam acceleration of MeV-class H(-) ion beams for ITER NB accelerator.

PubMed

Umeda, N; Kashiwagi, M; Taniguchi, M; Tobari, H; Watanabe, K; Dairaku, M; Yamanaka, H; Inoue, T; Kojima, A; Hanada, M

2014-02-01

In order to realize neutral beam systems in International Thermonuclear Experimental Reactor whose target is to produce a 1 MeV, 200 A/m(2) during 3600 s D(-) ion beam, the electrostatic five-stages negative ion accelerator so-called "MeV accelerator" has been developed at Japan Atomic Energy Agency. To extend pulse length, heat load of the acceleration grids was reduced by controlling the ion beam trajectory. Namely, the beam deflection due to the residual magnetic field of filter magnet was suppressed with the newly developed extractor with a 0.5 mm off-set aperture displacement. The new extractor improved the deflection angle from 6 mrad to 1 mrad, resulting in the reduction of direct interception of negative ions from 23% to 15% of the total acceleration power, respectively. As a result, the pulse length of 130 A/m(2), 881 keV H(-) ion beam has been successfully extended from a previous value of 0.4 s to 8.7 s. This is the first long pulse negative ion beam acceleration over 100 MW/m(2).

Electron energy boosting in laser-wake-field acceleration with external magnetic field Bapprox1 T and laser prepulses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hosokai, Tomonao; Zhidkov, Alexei; Yamazaki, Atsushi

2010-03-22

Hundred-mega-electron-volt electron beams with quasi-monoenergetic distribution, and a transverse geometrical emittance as small as approx0.02 pi mm mrad are generated by low power (7 TW, 45 fs) laser pulses tightly focused in helium gas jets in an external static magnetic field, Bapprox1 T. Generation of monoenergetic beams strongly correlates with appearance of a straight, at least 2 mm length plasma channel in a short time before the main laser pulse and with the energy of copropagating picosecond pedestal pulses (PPP). For a moderate energy PPP, the multiple or staged electron self-injection in the channel gives several narrow peaks in themore » electron energy distribution.« less

Optical diagnostics on ETA-II for x-ray spot size

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richardson, R A

1999-03-22

Improvements have been made in the performance of the ETA-II accelerator that allow a nominal 2 kA, 6 MeV beam to be focused to a spot size less that 1 mm in diameter. The improvements include reducing the energy sweep to less than +/- 0.5 & over 40 ns of the pulse using a real time energy diagnostic and improving the magnetic tune of the accelerator to reduce the emittance to 8 cm-mrad. Finally, an automated tuning system (MAESTRO) was run to minimize the time dependent centroid motion (corkscrew) by adjusting the steering dipoles over the focusing solenoids. The corkscrewmore » motion was reduced to less than +/- 0.5 mm at the output of the accelerator.« less

Improved ETA-II accelerator performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paul, A C; Boyd, J K; Chen, Y J

1999-03-22

Improvements have been made in the performance of the ETA-II accelerator that allow a nominal 2 kA, 6 MeV beam to be focused to a spot size less that 1 mm in diameter. The improvements include reducing the energy sweep to less than +/- 0.5 & over 40 ns of the pulse using a real time energy diagnostic and improving the magnetic tune of the accelerator to reduce the emittance to 8 cm-mrad. Finally, an automated tuning system (MAESTRO) was run to minimize the time dependent centroid motion (corkscrew) by adjusting the steering dipoles over the focusing solenoids. The corkscrewmore » motion was reduced to less than +/- 0.5 mm at the output of the accelerator.« less

Registration of 3D and Multispectral Data for the Study of Cultural Heritage Surfaces

PubMed Central

Chane, Camille Simon; Schütze, Rainer; Boochs, Frank; Marzani, Franck S.

2013-01-01

We present a technique for the multi-sensor registration of featureless datasets based on the photogrammetric tracking of the acquisition systems in use. This method is developed for the in situ study of cultural heritage objects and is tested by digitizing a small canvas successively with a 3D digitization system and a multispectral camera while simultaneously tracking the acquisition systems with four cameras and using a cubic target frame with a side length of 500 mm. The achieved tracking accuracy is better than 0.03 mm spatially and 0.150 mrad angularly. This allows us to seamlessly register the 3D acquisitions and to project the multispectral acquisitions on the 3D model. PMID:23322103

Development of a radio-frequency quadrupole cooler for high beam currents

NASA Astrophysics Data System (ADS)

Boussaid, Ramzi; Ban, G.; Quéméner, G.; Merrer, Y.; Lorry, J.

2017-12-01

The SHIRaC prototype is a recently developed radio-frequency quadrupole (RFQ) beam cooler with an improved optics design to deliver the required beam quality to a high resolution separator (HRS). For an isobaric separation of isotopes, the HRS demands beams with emittance not exceeding 3 π mm mrad and longitudinal energy spread ˜1 eV . Simulation studies showed a significant contribution of the buffer gas diffusion, space charge effect and mainly the rf fringe field to degrade the achieved beam quality at the RFQ exit. A miniature rf quadrupole (μ RFQ ) has been implemented at that exit to remove the degrading effects and provide beams with 1 eV of energy spread and around 1.75 π mm mrad of emittance for 4 Pa gas pressure. This solution enables also to transmit more than 60% of the incoming ions for currents up to 1 μ A . Detailed studies of this development are presented and discussed in this paper. Transport of beams from SHIRaC towards the HRS has been done with an electrostatic quadrupole triplet. Simulations and first experimental tests showed that more than 95% of ions can reach the HRS. Because SPIRAL-2 beams are of high current and very radioactive, the buffer gas will be highly contaminated. Safe maintenance of the SHIRaC beam line needs exceptional treatment of radioactive contaminants. For that, special vinyl sleep should be mounted on elements to be maintained. A detailed maintenance process will be presented.

New generation of compact high power disk lasers

NASA Astrophysics Data System (ADS)

Feuchtenbeiner, Stefanie; Zaske, Sebastian; Schad, Sven-Silvius; Gottwald, Tina; Kuhn, Vincent; Kumkar, Sören; Metzger, Bernd; Killi, Alexander; Haug, Patrick; Speker, Nicolai

2018-02-01

New technological developments in high power disk lasers emitting at 1030 nm are presented. These include the latest generation of TRUMPF's TruDisk product line offering high power disk lasers with up to 6 kW output power and beam qualities of up to 4 mm*mrad. With these compact devices a footprint reduction of 50% compared to the previous model could be achieved while at the same time improving robustness and increasing system efficiency. In the context of Industry 4.0, the new generation of TruDisk lasers features a synchronized data recording of all sensors, offering high-quality data for virtual analyses. The lasers therefore provide optimal hardware requirements for services like Condition Monitoring and Predictive Maintenance. We will also discuss its innovative and space-saving cooling architecture. It allows operation of the laser under very critical ambient conditions. Furthermore, an outlook on extending the new disk laser platform to higher power levels will be given. We will present a disk laser with 8 kW laser power out of a single disk with a beam quality of 5 mm*mrad using a 125 μm fiber, which makes it ideally suited for cutting and welding applications. The flexibility of the disk laser platform also enables the realization of a wide variety of beam guiding setups. As an example a new scheme called BrightLine Weld will be discussed. This technology allows for an almost spatter free laser welding process, even at high feed rates.

Development of a compact filament-discharge multi-cusp H- ion source.

PubMed

Jia, XianLu; Zhang, TianJue; Zheng, Xia; Qin, JiuChang

2012-02-01

A 14 MeV medical cyclotron with the external ion source has been designed and is being constructed at China Institute of Atomic Energy. The H(-) ion will be accelerated by this machine and the proton beam will be extracted by carbon strippers in dual opposite direction. The compact multi-cusp H(-) ion source has been developed for the cyclotron. The 79.5 mm long ion source is 48 mm in diameter, which is consisting of a special shape filament, ten columns of permanent magnets providing a multi-cusp field, and a three-electrode extraction system. So far, the 3 mA∕25 keV H(-) beam with an emittance of 0.3 π mm mrad has been obtained from the ion source. The paper gives the design details and the beam test results. Further experimental study is under way and an extracted beam of 5 mA is expected.

Diode lasers for direct application by utilizing a trepanning optic for remote oscillation welding of aluminum and copper

NASA Astrophysics Data System (ADS)

Fritsche, Haro; Müller, Norbert; Ferrario, Fabio; Fetissow, Sebastian; Grohe, Andreas; Hagen, Thomas; Steger, Ronny; Katzemaikat, Tristan; Ashkenasi, David; Gries, Wolfgang

2017-02-01

We report the first direct diode laser module integrated with a trepanning optic for remote oscillation welding. The trepanning optic is assembled with a collimated DirectProcess 900 laser engine. This modular laser is based on single emitters and beam combiners to achieve fiber coupled modules with a beam parameter product or BPP < 8 mm mrad at all power levels up to 1 kW, as well as free space collimated outputs with even lower BPP. The initial design consists in vertically stacking several diodes in the fast axis which leads to a rectangular output of about 100 W with BPP of <3.5 mm*mrad in the fast axis and <5 mm*mrad in the slow axis. Next, further power scaling is accomplished by polarization combining and wavelength multiplexing yielding high optical efficiencies of more than 80% and resulting in a building block module with over 500 W launched into a 100 μm fiber with 0.15 NA. The beam profile of the free space module remains rectangular, with a nearly flat top and conserves the beam parameter product of the original vertical stack without the power loss of fiber coupling. The 500 W building blocks feature a highly flexible emitting wavelength bandwidth. New wavelengths can be configured by simply exchanging parts and without modifying the production process. This design principle provides the option to adapt the wavelength configuration to match a broad set of applications, from the UV to the visible and to the far IR depending on the commercial availability of laser diodes. This opens numerous additional applications like laser pumping, scientific and medical applications, as well as materials processing applications such as cutting and welding of copper aluminum or steel. Furthermore, the module's short lead lengths enable very short pulses. Integrated with electronics, the module's pulse width can be adjusted from micro-seconds to cw mode operation by simple software commands. An optical setup can be directly attached instead of a fiber to the laser module thanks to its modular design. This paper's experimental results are based on a trepanning optic attached to the laser module. Alltogether the setup approximately fits in a shoe box and weighs less than 20 kg which allows for direct mounting onto a 3D-gantry system. The oscillating weld performance of the 500 W direct diode laser utilizing a novel trepanning optic is discussed for its application to aluminum/aluminum and aluminum/copper joints.

Simulated Performance of the Wisconsin Superconducting Electron Gun

DOE Office of Scientific and Technical Information (OSTI.GOV)

R.A. Bosch, K.J. Kleman, R.A. Legg

2012-07-01

The Wisconsin superconducting electron gun is modeled with multiparticle tracking simulations using the ASTRA and GPT codes. To specify the construction of the emittance-compensation solenoid, we studied the dependence of the output bunch's emittance upon the solenoid's strength and field errors. We also evaluated the dependence of the output bunch's emittance upon the bunch's initial emittance and the size of the laser spot on the photocathode. The results suggest that a 200-pC bunch with an emittance of about one mm-mrad can be produced for a free-electron laser.

Optical analysis of cylindrical-parabolic concentrators: validity limits for models of solar disk intensity.

PubMed

Nicolás, R O

1987-09-15

Different optical analysis of cylindrical-parabolic concentrators were made by utilizing four models of intensity distribution of the solar disk, i.e., square, uniform, real, and Gaussian. In this paper, the validity conditions using such distributions are determined by calculating each model of the intensity distribution on the receiver plane of perfect and nonperfect cylindrical-parabolic concentrators. We call nonperfect concentrators those in which the normal to each differential element of the specular surface departs from its correct position by an angle sigma(epsilon), the possible values of which follow a Gaussian distribution of mean value epsilon and standard deviation sigma(epsilon). In particular, the results obtained with the models considered for a concentrator with an aperture half-angle of 45 degrees are shown and compared. An important conclusion is that for sigma(epsilon) greater, similar 4 mrad, in some cases for sigma(epsilon) greater, similar 2 mrad, the results obtained are practically independent of the model used.

Comparison of different hadron production models for the study of π±, K±, protons and antiprotons production in proton-carbon interactions at 90 GeV/c

NASA Astrophysics Data System (ADS)

Ajaz, M.; Ali, Y.; Ullah, S.; Ali, Q.; Tabassam, U.

2018-05-01

In this research paper, comprehensive results on the double differential yield of π± and K± mesons, protons and antiprotons as a function of laboratory momentum in several polar angle ranges from 0-420 mrad for pions, 0-360 mrad for kaons, proton and antiproton are reported. EPOS 1.99, EPOS-LHC and QGSJETII-04 models are used to perform simulations. The predictions of these models at 90 GeV/c are plotted for comparison, which shows that QGSJETII-04 model gives overall higher yield for π+ mesons in the polar angle interval of 0-40 mrad but for the π‑ the yield is higher only up to 20 mrad. For π+ mesons after 40 mrad, EPOS-LHC predicts higher yield as compared to EPOS 1.99 and QGSJETII-04 while EPOS-LHC and EPOS 1.99 give similar behavior in these two intervals. However, for π‑ mesons EPOS-LHC and EPOS 1.99 give similar behavior in these two intervals. For of K± mesons, QGSJETII-04 model gives higher predictions in all cases from 0-300 mrad, while EPOS 1.99 and EPOS-LHC show similar distributions. In case of protons, all models give similar distribution but this is not true for antiproton. All models are in good agreement for p > 20 GeV/c. EPOS 1.99 produce lower yield compared to the other two models from 60-360 mrad polar angle interval.

VUV spectroscopic observations on the SABRE applied-B ion diode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Filuk, A.B.; Nash, T.J.; Noack, D.D.

We are using VUV spectroscopy to study the ion source region on the SABRE applied-B extraction ion diode. The VUV diagnostic views the anode-cathode gap perpendicular to the ion acceleration direction, and images a region 0--1 mm from the anode onto the entrance slit of a I m normal-incidence spectrometer. Time resolution is obtained by gating multiple striplines of a CuI- or MgF{sub 2} -coated micro-channel plate intensifier. We report on results with a passive proton/carbon ion source. Lines of carbon and oxygen are observed over 900--1600 {angstrom}. The optical depths of most of the lines are less than ormore » of order 1. Unfolding the Doppler broadening of the ion lines in the source plasma, we calculate the contribution of the source to the accelerated C IV ion micro-divergence as 4 mrad at peak power. Collisional-radiative modeling of oxygen line intensities provides the source plasma average electron density of 7{times}10{sup 16} cm{sup {minus}3} and temperature of 10 eV Measurements are planned with a lithium ion source and with VUV absorption spectroscopy.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

WATANABE, T.; LIU, D.; MURPHY, J.B.

The strong focusing VISA undulator is presented in this report. The proposed FEL will operate at the 1 {micro}m water window. Extensive simulations were performed to optimize an FEL amplifier based on the two-meter long VISA undulator which has a period of 1.8 cm and an undulator parameter K = 1.26. The betatron function inside the VISA undulator is about 30 cm. For an electron beam with a peak current {approx}1 kA and a normalized emittance of 5 mm-mrad, the FEL peak power can exceed 1 GW within the 2 m VISA undulator using a 5 kW peak power seedmore » laser. Such a device can produce a megawatt of average power for a 700 MHz rep rate. The transverse distribution of the FEL radiation along the undulator, as well as after the undulator, is explored by numerical simulation. The FEL power density at 5 m downstream from the undulator is less than 100 kW/cm{sup 2} for this MW-class FEL. We will also discuss the feasibility of an experimental demonstration of the laser seeded FEL amplifier based on the 2-m VISA undulator at the NSLS Source Development Lab (SDL).« less

The use of portable intraoperative computed tomography scanning for real-time image guidance: a pilot cadaver study.

PubMed

Das, Subinoy; Maeso, Patricia A; Figueroa, Ramon E; Senior, Brent A; Delgaudio, John M; Sillers, Michael J; Schlosser, Rod J; Kountakis, Stilianos E

2008-01-01

This study was performed to assess the feasibility of using intraoperative computed tomography (CT) to provide real-time updates to image guidance systems (IGSs) during surgery. The xCAT ENT portable intraoperative CT scanner (Xoran Technologies, Ann Arbor, MI) was used to acquire scans before, midway, and at the end of six cadaver dissections during the Southern States Rhinology Course, Augusta, GA, in October 2006. These scans were used to recalibrate three different IGSs used during the dissection. Time measurements were recorded and dosimetry was obtained from the cornea, sphenoid sinus (near the optic chiasm), and from the operative field during acquisition of the images. IGS accuracy was determined at the skull base and lamina papyracea. Surgeons were interviewed on benefits of real-time updates to the IGS after completion of dissections. The xCAT ENT scanner was compatible with all three IGS platforms. The average time to update the IGS was 13 minutes. Radiation doses to the cornea were 620 mrad per scan, and optic chiasm was 800 mrad/scan. The accuracy at the anterior skull base improved from 1.58 to 0.62 mm (p=0.026). The accuracy at the posterior skull base improved from 1.46 to 0.71 mm (p=0.014). The accuracy at the lamina was not significantly changed. Intraoperative portable CT scanning with real-time IGS updates is feasible and likely would add little additional time. Accuracy is improved at the skull base. Prospective studies on actual patients are warranted.

Continued improvement in reduced-mode (REM) diodes enable 272 W from 105 μm 0.15 NA beam

NASA Astrophysics Data System (ADS)

Kanskar, M.; Bao, L.; Chen, Z.; Dawson, D.; DeVito, M.; Dong, W.; Grimshaw, M.; Guan, X.; Hemenway, M.; Martinsen, R.; Urbanek, W.; Zhang, S.

2017-02-01

High-power, high-brightness diode lasers from 8xx nm to 9xx nm have been pursued in many applications including fiber laser pumping, materials processing, solid-state laser pumping, and consumer electronics manufacturing. In particular, 915 nm - 976 nm diodes are of interest as diode pumps for the kilowatt CW fiber lasers. Thus, there have been many technical efforts on driving the diode lasers to have both high power and high brightness to achieve high-performance and reduced manufacturing costs. This paper presents our continued progress in the development of high brightness fiber-coupled product platform, elementTM. In the past decade, the amount of power coupled into a single 105 μm and 0.15 NA fiber has increased by over a factor of ten through improved diode laser brilliance and the development of techniques for efficiently coupling multiple emitters into a single fiber. In this paper, we demonstrate the further brightness improvement and power-scaling enabled by both the rise in chip brightness/power and the increase in number of chips coupled into a given numerical aperture. We report a new x-REM design with brightness as high as 4.3 W/mm-mrad at a BPP of 3 mm-mrad. We also report the record 272W from a 2×9 elementTM with 105 μm/0.15 NA beam using x-REM diodes and a new product introduction at 200W output power from 105 μm/0.15 NA beam at 915 nm.

Improvement in reduced-mode (REM) diodes enable 315 W from 105-μm 0.15-NA fiber-coupled modules

NASA Astrophysics Data System (ADS)

Kanskar, M.; Bao, L.; Chen, Z.; Dawson, D.; DeVito, M.; Dong, W.; Grimshaw, M.; Guan, X.; Hemenway, M.; Martinsen, R.; Urbanek, W.; Zhang, S.

2018-02-01

High-power, high-brightness diode lasers have been pursued for many applications including fiber laser pumping, materials processing, solid-state laser pumping, and consumer electronics manufacturing. In particular, 915 nm - and 976 nm diodes are of interest as diode pumps for the kilowatt CW fiber lasers. As a result, there have been many technical thrusts for driving the diode lasers to have both high power and high brightness to achieve high-performance and reduced manufacturing costs. This paper presents our continued progress in the development of high brightness fiber-coupled product platform, nLIGHT element®. In the past decade, the power coupled into a single 105 μm and 0.15 NA fiber has increased by over a factor of ten through improved diode laser brightness and the development of techniques for efficiently coupling multiple emitters. In this paper, we demonstrate further brightness improvement and power-scaling enabled by both the rise in chip brightness/power and the increase in number of chips coupled into a given numerical aperture. We report a new chip technology using x-REM design with brightness as high as 4.3 W/mm-mrad at a BPP of 3 mm-mrad. We also report record 315 W output from a 2×12 nLIGHT element with 105 μm diameter fiber using x-REM diodes and these diodes will allow next generation of fiber-coupled product capable of 250W output power from 105 μm/0.15 NA beam at 915 nm.

SU-F-T-153: Experimental Validation and Calculation Benchmark for a Commercial Monte Carlo Pencil Beam Scanning Proton Therapy Treatment Planning System in Water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, L; Huang, S; Kang, M

Purpose: Eclipse proton Monte Carlo AcurosPT 13.7 was commissioned and experimentally validated for an IBA dedicated PBS nozzle in water. Topas 1.3 was used to isolate the cause of differences in output and penumbra between simulation and experiment. Methods: The spot profiles were measured in air at five locations using Lynx. PTW-34070 Bragg peak chamber (Freiburg, Germany) was used to collect the relative integral Bragg peak for 15 proton energies from 100 MeV to 225 MeV. The phase space parameters (σx, σθ, ρxθ) number of protons per MU, energy spread and calculated mean energy provided by AcurosPT were identically implementedmore » into Topas. The absolute dose, profiles and field size factors measured using ionization chamber arrays were compared with both AcurosPT and Topas. Results: The beam spot size, σx, and the angular spread, σθ, in air were both energy-dependent: in particular, the spot size in air at isocentre ranged from 2.8 to 5.3 mm, and the angular spread ranged from 2.7 mrad to 6 mrad. The number of protons per MU increased from ∼9E7 at 100 MeV to ∼1.5E8 at 225 MeV. Both AcurosPT and TOPAS agree with experiment within 2 mm penumbra difference or 3% dose difference for scenarios including central axis depth dose and profiles at two depths in multi-spot square fields, from 40 to 200 mm, for all the investigated single-energy and multi-energy beams, indicating clinically acceptable source model and radiation transport algorithm in water. Conclusion: By comparing measured data and TOPAS simulation using the same source model, the AcurosPT 13.7 was validated in water within 2 mm penumbra difference or 3% dose difference. Benchmarks versus an independent Monte Carlo code are recommended to study the agreement in output, filed size factors and penumbra differences. This project is partially supported by the Varian grant under the master agreement between University of Pennsylvania and Varian.« less

HLW Flexible jumper materials compatibility evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skidmore, T. E.

H-Tank Farm Engineering tasked SRNL/Materials Science & Technology (MS&T) to evaluate the compatibility of Goodyear Viper® chemical transfer hose with HLW solutions. The hose is proposed as a flexible Safety Class jumper for up to six months service. SRNL/MS&T performed various tests to evaluate the effects of radiation, high pH chemistry and elevated temperature on the hose, particularly the inner liner. Test results suggest an upper dose limit of 50 Mrad for the hose. Room temperature burst pressure values at 50 Mrad are estimated at 600- 800 psi, providing a safety factor of 4.0-5.3X over the anticipated operating pressure ofmore » 150 psi and a safety factor of 3.0-4.0X over the working pressure of the hose (200 psi), independent of temperature effects. Radiation effects are minimal at doses less than 10 Mrad. Doses greater than 50 Mrad may be allowed, depending on operating conditions and required safety factors, but cannot be recommended at this time. At 250 Mrad, burst pressure values are reduced to the hose working pressure. At 300 Mrad, burst pressures are below 150 psi. At a bounding continuous dose rate of 57,870 rad/hr, the 50 Mrad dose limit is reached within 1.2 months. Actual dose rates may be lower, particularly during non-transfer periods. Refined dose calculations are therefore recommended to justify longer service. This report details the tests performed and interpretation of the results. Recommendations for shelf-life/storage, component quality verification, and post-service examination are provided.« less

Electromagnetic and geometric characterization of accelerated ion beams by laser ablation

NASA Astrophysics Data System (ADS)

Nassisi, V.; Velardi, L.; Side, D. Delle

2013-05-01

Laser ion sources offer the possibility to get ion beam useful to improve particle accelerators. Pulsed lasers at intensities of the order of 108 W/cm2 and of ns pulse duration, interacting with solid matter in vacuum, produce plasma of high temperature and density. The charge state distribution of the plasma generates high electric fields which accelerate ions along the normal to the target surface. The energy of emitted ions has a Maxwell-Boltzmann distribution which depends on the ion charge state. To increase the ion energy, a post-acceleration system can be employed by means of high voltage power supplies of about 100 kV. The post acceleration system results to be a good method to obtain high ion currents by a not expensive system and the final ion beams find interesting applications in the field of the ion implantation, scientific applications and industrial use. In this work we compare the electromagnetic and geometric properties, like emittance, of the beams delivered by pure Cu, Y and Ag targets. The characterization of the plasma was performed by a Faraday cup for the electromagnetic characteristics, whereas a pepper pot system was used for the geometric ones. At 60 kV accelerating voltage the three examined ion bunches get a current peak of 5.5, 7.3 and 15 mA, with a normalized beam emittance of 0.22, 0.12 and 0.09 π mm mrad for the targets of Cu, Y, and Ag, respectively.

Development of a Watt-level gamma-ray source based on high-repetition-rate inverse Compton scattering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mihalcea, D.; Murokh, A.; Piot, P.

2017-07-01

A high-brilliance (~10 22 photon s -1 mm -2 mrad -2 /0.1%) gamma-ray source experiment is currently being planned at Fermilab (E γ≃1.1 MeV). The source implements a high-repetition-rate inverse Compton scattering by colliding electron bunches formed in a ~300-MeV superconducting linac with a high-intensity laser pulse. This paper describes the design rationale along with some of technical challenges associated to producing high-repetition-rate collision. The expected performances of the gamma-ray source are also presented.

All-fiber 7x1 signal combiner for incoherent laser beam combining

NASA Astrophysics Data System (ADS)

Noordegraaf, D.; Maack, M. D.; Skovgaard, P. M. W.; Johansen, J.; Becker, F.; Belke, S.; Blomqvist, M.; Laegsgaard, J.

2011-02-01

We demonstrate an all-fiber 7x1 signal combiner for incoherent laser beam combining. This is a potential key component for reaching several kW of stabile laser output power. The combiner couples the output from 7 single-mode (SM) fiber lasers into a single multi-mode (MM) fiber. The input signal fibers have a core diameter of 17 μm and the output MM fiber has a core diameter of 100 μm. In a tapered section light gradually leaks out of the SM fibers and is captured by a surrounding fluorine-doped cladding. The combiner is tested up to 2.5 kW of combined output power and only a minor increase in device temperature is observed. At an intermediate power level of 600 W a beam parameter product (BPP) of 2.22 mm x mrad is measured, corresponding to an M2 value of 6.5. These values are approaching the theoretical limit dictated by brightness conservation.

High-throughput Toroidal Grating Beamline for Photoelectron Spectroscopy at CAMD

PubMed Central

Kizilkaya, O; Jiles, R W; Patterson, M C; Thibodeaux, C A; Poliakoff, E D; Sprunger, P T; Kurtz, R L; Morikawa, E

2016-01-01

A 5 meter toroidal grating (5m-TGM) beamline has been commissioned to deliver 28 mrad of bending magnet radiation to an ultrahigh vacuum endstation chamber to facilitate angle resolved photoelectron spectroscopy. The 5m-TGM beamline is equipped with Au-coated gratings with 300, 600 and 1200 lines/mm providing monochromatized synchrotron radiation in the energy ranges 25-70 eV, 50–120 eV and 100–240 eV, respectively. The beamline delivers excellent flux (~1014-1017 photons/sec/100mA) and a combined energy resolution of 189 meV for the beamline (at 1.0 mm slit opening) and HA-50 hemispherical analyzer was obtained at the Fermi level of polycrystalline gold crystal. Our preliminary photoelectron spectroscopy results of phenol adsorption on TiO2 (110) surface reveals the metal ion (Ti) oxidation. PMID:27134636

Effect of Temperature of Liquid Nitrogen on Radiation Resistance of Spores of Clostridium botulinum1

PubMed Central

Grecz, Nicholas; Snyder, O. P.; Walker, A. A.; Anellis, A.

1965-01-01

An apparatus consisting of a Dewar flask and a relay system controlling the flow of liquid nitrogen permitted the irradiation of samples in tin cans or Pyrex tubes at temperatures ranging from 0 ± 1.5 C to -194 ± 2 C. An inoculated pack comprising 320 cans of ground beef containing 5 × 104 spores of Clostridium botulinum 33A per can (10 cans per radiation dose) was irradiated with Co60 at 0 and -196 C. Incubation was carried out at 30 C for 6 months. Approximately 0.9 Mrad more radiation was required to inactivate the spores at -196 C than at 0 C. Cans irradiated at -196 C showed partial spoilage at 3.6 Mrad and no spoilage at 3.9 Mrad; the corresponding spoilage-no spoilage doses at 0 C were 2.7 and 3.0, respectively. The majority of positive cans swelled in 2 to 14 days; occasional swelling occurred as late as 20 days. At progressively higher doses, swelling was delayed proportionally to the radiation dose received. The remaining nonswollen cans had no toxin after 6 months of storage, although occasional cans contained very low numbers of viable spores comprising on the average 0.1% of the original spore inoculum. The D10 values in phosphate buffer were 0.290 Mrad for 0 C and 0.396 Mrad for -196 C; in ground beef, the corresponding D10 values were 0.463 Mrad and 0.680 Mrad, respectively. These D10 values indicate that the lethal effect of γ rays decreased at -196 C as compared with 0 C by 13.5% in phosphate buffer, and by 47% in ground beef. Images Fig. 1 Fig. 2 Fig. 5 Fig. 6 Fig. 7 PMID:14339257

Digital Beam Steering Device Based on Decoupled Birefringent Prism Deflector and Polarization Rotator

NASA Technical Reports Server (NTRS)

Pishnyak, Oleg; Kreminska, Lyubov; Laventovich, Oleg D.; Pouch, John J.; Miranda, Felix A.; Winker, Bruce K.

2004-01-01

We describe digital beam deflectors (DBDs) based on liquid crystals. Each stage of the device comprises a polarization rotator and a birefringent prism deflector. The birefringent prism deflects the beam by an angle that depends on polarization of the incident beam. The prism can be made of the uniaxial smectic A (SmA) liquid crystal (LC) or a solid crystal such as yttrium orthovanadate (YVO4). SmA prisms have high birefringence and can be constructed in a variety of shapes, including single prisms and prismatic blazed gratings of different angles and profiles. We address the challenges of uniform alignment of SmA, such as elimination of focal conic domains. Rotation of linear polarization is achieved by an electrically switched twisted nematic (TN) cell. A DBD composed of N rotator-deflector pairs steers the beam into 2(sup N) directions. As an example, we describe a four-stage DBD deflecting normally incident laser beam within the range of +/- 56 mrad with 8 mrad steps. Redirection of the beam is achieved by switching the TN cells.

The Effects of ELDRS at Ultra-Low Dose Rates

NASA Technical Reports Server (NTRS)

Chen, Dakai; Forney, James; Carts, Martin; Phan, Anthony; Pease, Ronald; Kruckmeyer, Kirby; Cox, Stephen; LaBel, Kenneth; Burns, Samuel; Albarian, Rafi;

The Mars Science Laboratory Curiosity rover Mastcam instruments: Preflight and in-flight calibration, validation, and data archiving

NASA Astrophysics Data System (ADS)

Bell, J. F.; Godber, A.; McNair, S.; Caplinger, M. A.; Maki, J. N.; Lemmon, M. T.; Van Beek, J.; Malin, M. C.; Wellington, D.; Kinch, K. M.; Madsen, M. B.; Hardgrove, C.; Ravine, M. A.; Jensen, E.; Harker, D.; Anderson, R. B.; Herkenhoff, K. E.; Morris, R. V.; Cisneros, E.; Deen, R. G.

2017-07-01

The NASA Curiosity rover Mast Camera (Mastcam) system is a pair of fixed-focal length, multispectral, color CCD imagers mounted 2 m above the surface on the rover's remote sensing mast, along with associated electronics and an onboard calibration target. The left Mastcam (M-34) has a 34 mm focal length, an instantaneous field of view (IFOV) of 0.22 mrad, and a FOV of 20° × 15° over the full 1648 × 1200 pixel span of its Kodak KAI-2020 CCD. The right Mastcam (M-100) has a 100 mm focal length, an IFOV of 0.074 mrad, and a FOV of 6.8° × 5.1° using the same detector. The cameras are separated by 24.2 cm on the mast, allowing stereo images to be obtained at the resolution of the M-34 camera. Each camera has an eight-position filter wheel, enabling it to take Bayer pattern red, green, and blue (RGB) "true color" images, multispectral images in nine additional bands spanning 400-1100 nm, and images of the Sun in two colors through neutral density-coated filters. An associated Digital Electronics Assembly provides command and data interfaces to the rover, 8 Gb of image storage per camera, 11 bit to 8 bit companding, JPEG compression, and acquisition of high-definition video. Here we describe the preflight and in-flight calibration of Mastcam images, the ways that they are being archived in the NASA Planetary Data System, and the ways that calibration refinements are being developed as the investigation progresses on Mars. We also provide some examples of data sets and analyses that help to validate the accuracy and precision of the calibration.

High-power CW and long-pulse lasers in the green wavelength regime for copper welding

NASA Astrophysics Data System (ADS)

Pricking, Sebastian; Huber, Rudolf; Klausmann, Konrad; Kaiser, Elke; Stolzenburg, Christian; Killi, Alexander

2016-03-01

We report on industrial high-power lasers in the green wavelength regime. By means of a thin disk oscillator and a resonator-internal nonlinear crystal for second harmonic generation we are able to extract up to 8 kW pulse power in the few-millisecond range at a wavelength of 515 nm with a duty cycle of 10%. Careful shaping and stabilization of the polarization and spectral properties leads to a high optical-to-optical efficiency larger than 55%. The beam parameter product is designed and measured to be below 5 mm·mrad which allows the transport by a fiber with a 100 μm core diameter. The fiber and beam guidance optics are adapted to the green wavelength, enabling low transmission losses and stable operation. Application tests show that this laser is perfectly suited for copper welding due to the superior absorption of the green wavelength compared to IR, which allows us to produce weld spots with an unprecedented reproducibility in diameter and welding depth. With an optimized set of parameters we could achieve a splatter-free welding process of copper, which is crucial for welding electronic components. Furthermore, the surface condition does not influence the welding process when the green wavelength is used, which allows to skip any expensive preprocessing steps like tin-coating. With minor changes we could operate the laser in cw mode and achieved up to 1.7 kW of cw power at 515 nm with a beam parameter product of 2.5 mm·mrad. These parameters make the laser perfectly suitable for additional applications such as selective laser melting of copper.

Narrow-stripe broad-area lasers with distributed-feedback surface gratings as brilliant sources for high power spectral beam combining systems

NASA Astrophysics Data System (ADS)

Decker, J.; Crump, P.; Fricke, J.; Wenzel, H.; Maaβdorf, A.; Erbert, G.; Tränkle, G.

2014-03-01

Laser systems based on spectral beam combining (SBC) of broad-area (BA) diode lasers are promising tools for material processing applications. However, the system brightness is limited by the in-plane beam param- eter product, BPP, of the BA lasers, which operate with a BPP of < 3mm-mrad. The EU project BRIDLE (www.bridle.eu) is developing novel diode laser sources for such systems, and several technological advances are sought. For increased system brightness and optimal ber-coupling the diode lasers should operate with reduced BPP and vertical far eld angle (95% power content), μV 95. The resulting diode lasers are fabricated as mini- bars for reduced assembly costs. Gratings are integrated into the mini-bar, with each laser stripe emitting at a different wavelength. In this way, each emitter can be directed into a single bre via low-cost dielectric filters. Distributed-feedback narrow-stripe broad-area (DFB-NBA) lasers are promising candidates for these SBC sys- tems. We review here the design process and performance achieved, showing that DFB-NBA lasers with stripe width, W = 30 μm, successfully cut of higher-order lateral modes, improving BPP. Uniform, surface-etched, 80th-order Bragg gratings are used, with weak gratings essential for high e ciency. To date, such DFB-NBA sources operate with < 50% effciency at output power, Pout < 6 W, with BPP < 1.8 mm-mrad and offV 95 36 . The emission wavelength is about 970 nm and the spectral width is < 0.7 nm (95% power). The BPP is half that of a DFB-BA lasers with W = 90 um. We conclude with a review of options for further performance improvements.

A long baseline RICH with a 27-kiloton water target and radiator for detection of neutrino oscillations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ypsilantis, T.; Seguinot, J.; Zichichi, A.

1997-01-01

A 27 kt water volume is investigated as a target for a long baseline neutrino beam from CERN to Gran Sasso. Charged secondaries from the neutrino interactions produce Cherenkov photons in water which are imaged as rings by a spherical mirror. The photon detector elements are 14 400 photomultipliers (PM`s) of 127 mm diameter or 3600 HPD`s of 250 mm diameter with single photon sensitivity. A coincidence signal of about 300 pixel elements in time with the SPS beam starts readout in bins of 1 ns over a period of 128 ns. Momentum, direction, and velocity of hadrons and muconsmore » are determined from the width, center, and radius of the rings, respectively. Momentum is measured if multiple scattering dominates the ring width, as is the case for most of the particles of interest. Momentum, direction, and velocity of hadrons and muons are determined from the width, center, and radius of the rings, respectively. Momentum is measured if multiple scattering dominates the ring width, as is the case for most of the particles of interest. Momentum resolutions of 1-10%, mass resolutions of 5-50 MeV, and direction resolutions of < 1 mrad are achievable. Thresholds in water for muons, pions, kaons, and protons are 0.12, 0.16, 0.55, and 1.05 GeV/c, respectively. Electrons and gammas can be measured with energy resolution {sigma}{sub E}/E{approx}8.5%/{radical}E(GeV) and with direction resolution {approx} 1 mrad. The detector can be sited either inside a Gran Sasso tunnel or above ground because it is directional and the SPS beam is pulsed; thus the rejection of cosmic ray background is excellent.« less

Demonstration of passive plasma lensing of a laser wakefield accelerated electron bunch

DOE PAGES

Kuschel, S.; Hollatz, D.; Heinemann, T.; ...

2016-07-20

We report on the first demonstration of passive all-optical plasma lensing using a two-stage setup. An intense femtosecond laser accelerates electrons in a laser wakefield accelerator (LWFA) to 100 MeV over millimeter length scales. By adding a second gas target behind the initial LWFA stage we introduce a robust and independently tunable plasma lens. We observe a density dependent reduction of the LWFA electron beam divergence from an initial value of 2.3 mrad, down to 1.4 mrad (rms), when the plasma lens is in operation. Such a plasma lens provides a simple and compact approach for divergence reduction well matchedmore » to the mm-scale length of the LWFA accelerator. The focusing forces are provided solely by the plasma and driven by the bunch itself only, making this a highly useful and conceptually new approach to electron beam focusing. Possible applications of this lens are not limited to laser plasma accelerators. Since no active driver is needed the passive plasma lens is also suited for high repetition rate focusing of electron bunches. As a result, its understanding is also required for modeling the evolution of the driving particle bunch in particle driven wake field acceleration.« less

Extremely high-brightness kW-class fiber coupled diode lasers with wavelength stabilization

NASA Astrophysics Data System (ADS)

Huang, Robin K.; Chann, Bien; Glenn, John D.

2011-06-01

TeraDiode has produced ultra-high brightness fiber-coupled direct diode lasers. A fiber-coupled direct diode laser with a power level of 1,040 W from a 200 μm core diameter, 0.18 numerical aperture (NA) output fiber at a single center wavelength was demonstrated. This was achieved with a novel beam combining and shaping technique using COTS diode lasers. The fiber-coupled output corresponds to a Beam Parameter Product (BPP) of 18 mm-mrad and is the lowest BPP kW-class direct diode laser yet reported. The laser has been used to demonstrate laser cutting and welding of steel sheet metal up to 6.65 mm thick. Higher brightness fiber-coupled diode lasers, including a module with 418 W of power coupled to a 100 μm, 0.15 NA fiber, have also been demonstrated.

Research and development toward a 4.5-1.5 Å linac coherent light source (LCLS) at SLAC

NASA Astrophysics Data System (ADS)

Tatchyn, R.; Arthur, J.; Baltay, M.; Bane, K.; Boyce, R.; Cornacchia, M.; Cremer, T.; Fisher, A.; Hahn, S.-J.; Hernandez, M.; Loew, G.; Miller, R.; Nelson, W. R.; Nuhn, H.-D.; Palmer, D.; Paterson, J.; Raubenheimer, T.; Weaver, J.; Wiedemann, H.; Winick, H.; Pellegrini, C.; Travish, G.; Scharlemann, E. T.; Caspi, S.; Fawley, W.; Halbach, K.; Kim, K.-J.; Schlueter, R.; Xie, M.; Meyerhofer, D.; Bonifacio, R.; De Salvo, L.

1996-02-01

In recent years significant studies have been initiated on the feasibility of utilizing a portion of the 3 km S-band accelerator at SLAC to drive a short wavelength (4.5-1.5 Å) Linac Coherent Light Source (LCLS), a Free-Electron Laser (FEL) operating in the Self-Amplified Spontaneous Emission (SASE) regime. Electron beam requirements for single-pass saturation in a minimal time include: 1) a peak current in the 7 kA range, 2) a relative energy spread of <0.05%, and 3) a transverse emittance, ɛ [rad-m], approximating the diffraction-limit condition ɛ = {λ}/{4π}, where λ[m] is the output wavelength. Requirements on the insertion device include field error levels of 0.02% for keeping the electron bunch centered on and in phase with the amplified photons, and a focusing beta of 8 m/rad for inhibiting the dilution of its transverse density. Although much progress has been made in developing individual components and beam-processing techniques necessary for LCLS operation down to ˜20 Å, a substantial amount of research and development is still required in a number of theoretical and experimental areas leading to the construction and operation of a 4.5-1.5 Å LCLS. In this paper we report on a research and development program underway and in planning at SLAC for addressing critical questions in these areas. These include the construction and operation of a linac test stand for developing laser-driven photocathode rf guns with normalized emittances approaching 1 mm-mrad; development of advanced beam compression, stability, and emittance control techniques at multi-GeV energies; the construction and operation of a FEL Amplifier Test Experiment (FATE) for theoretical and experimental studies of SASE at IR wavelengths; an undulator development program to investigate superconducting, hybrid/permanent magnet (hybrid/PM), and pulsed-Cu technologies; theoretical and computational studies of high-gain FEL physics and LCLS component designs; development of X-ray optics and instrumentation for extracting, modulating, and delivering photons to experimental users; and the study and development of scientific experiments made possible by the source properties of the LCLS.

POSSIBLE APPLICATIONS OF IONIZING RADIATIONS IN THE FRUIT, VEGETABLE AND RELATED INDUSTRIES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clarke, I.D.

1959-10-01

Some effects of gamma radiation have been observed on the texture, flavor, and processing properties of fruits and vegetables. An appreciable reduction in mold decay of strawberries during storage at 20 and 1 deg C has been observed after treatment with 0.2 to 0.4 Mrad. Flavor was affected slightly and the viscosity of the juice was reduced considerably. The viscosity of juice extracted from irradiated whole berries, was reduced considerably by doses between 0.4 and 0.6 Mrad without critically affecting the flavor of the juice. The irradiated berries were free from a significant number of mold spores. No immediate commercialmore » application was foreseen in the black current juice industry. Plums were shown to be free from mold after a treatment of 0.4 Mrad and the initial spore count of apples is considerably reduced by a dose of 0.2 Mrad. Some evidence has been obtained that the softening of pears can be delayed by a dose of 0.3 and 0.5 Mrad. The published literature on the effects of radiation on other fruits and vegetables has been reviewed and commented upon. (auth)« less

Design, construction and measurements of an alpha magnet as a solution for compact bunch compressor for the electron beam from Thermionic RF Gun

NASA Astrophysics Data System (ADS)

Rajabi, A.; Jazini, J.; Fathi, M.; Sharifian, M.; Shokri, B.

2018-03-01

The beam produced by a thermionic RF gun has wide energy spread that makes it unsuitable for direct usage in photon sources. Here in the present work, we optimize the extracted beam from a thermionic RF gun by a compact economical bunch compressor. A compact magnetic bunch compressor (Alpha magnet) is designed and constructed. A comparison between simulation results and experimental measurements shows acceptable conformity. The beam dynamics simulation results show a reduction of the energy spread as well as a compression of length less than 1 ps with 2.3 mm-mrad emittance.

Light-weight spherical mirrors for Cherenkov detectors

NASA Astrophysics Data System (ADS)

Cisbani, E.; Colilli, S.; Crateri, R.; Cusanno, F.; Fratoni, R.; Frullani, S.; Garibaldi, F.; Giuliani, F.; Gricia, M.; Iodice, M.; Iommi, R.; Lucentini, M.; Mostarda, A.; Pierangeli, L.; Santavenere, F.; Urciuoli, G. M.; De Leo, R.; Lagamba, L.; Nappi, E.; Braem, A.; Vernin, P.

2003-01-01

Light-weight spherical mirrors have been appositely designed and built for the gas threshold Cherenkov detectors of the two Hall A spectrometers. The mirrors are made of a 1 mm thick aluminized plexiglass sheet, reinforced by a rigid backing consisting of a phenolic honeycomb sandwiched between two carbon fiber mats epoxy glued. The produced mirrors have a thickness equivalent to 0.55% of radiation length, and an optical slope error of about 5.5 mrad. These characteristics make these mirrors suitable for the implementation in Cherenkov threshold detectors. Ways to improve the mirror features are also discussed in view of their possible employment in RICH detectors.

The 80 kV electrostatic wire septum for AmPS

NASA Astrophysics Data System (ADS)

Vanderlinden, A.; Bijleveld, J. H. M.; Rookhuizen, H. Boer; Bruinsma, P. J. T.; Heine, E.; Lassing, P.; Prins, E.

The characteristics of the wire septum for the Amsterdam Pulse Stretcher (AmPS) are summarized. In the extraction process of the AmPS the extracted beam is intercepted from the circulating beam by the 1 m long electrostatic wire septum. For a bending angle of 4.4 mrad, the maximum anode voltage is 80 kV. The system developed consists of a wire spacing of 0.65 mm between tungsten wires of 50 micrometers diameter. Stainless steel spring wires, bent in a half cylindrical carrier, stretch the septum wires two by two. Prototype tests were successful up to an anode voltage of 120 kV.

Operation Status of the J-PARC Negative Hydrogen Ion Source

NASA Astrophysics Data System (ADS)

Oguri, H.; Ikegami, K.; Ohkoshi, K.; Namekawa, Y.; Ueno, A.

2011-09-01

A cesium-free negative hydrogen ion source driven with a lanthanum hexaboride (LaB6) filament is being operated without any serious trouble for approximately four years in J-PARC. Although the ion source is capable of producing an H- ion current of more than 30 mA, the current is routinely restricted to approximately 16 mA at present for the stable operation of the RFQ linac which has serious discharge problem from September 2008. The beam run is performed during 1 month cycle, which consisted of a 4-5 weeks beam operation and a few days down-period interval. At the recent beam run, approximately 700 h continuous operation was achieved. At every runs, the beam interruption time due to the ion source failure is a few hours, which correspond to the ion source availability of more than 99%. The R&D work is being performed in parallel with the operation in order to enhance the further beam current. As a result, the H- ion current of 61 mA with normalized rms emittance of 0.26 πmm.mrad was obtained by adding a cesium seeding system to a J-PARC test ion source which has the almost same structure with the present J-PARC ion source.

Demonstrating H- beam focusing using an elliptical einzel lens

NASA Astrophysics Data System (ADS)

Lawrie, S. R.; Faircloth, D. C.; Letchford, A. P.; Whitehead, M. O.; Wood, T.

2017-08-01

H- ion source research is being performed at the ISIS spallation neutron and muon facility on a dedicated Vessel for Extraction and Source Plasma Analyses (VESPA). The ion extraction and optics system presently being used on ISIS is centered on a combined-function sector dipole magnet. This traps cesium vapor escaping the ion source; mass-separates co-extracted electrons and stripped neutrals, and weak-focusses the highly asymmetric slit-shaped ion beam. Unfortunately the added drift length through the magnet under strong space-charge forces means up to 50% of the beam is collimated on the magnet. The VESPA has shown that the ISIS ion source actually produces 80 mA of beam current at standard settings, but because of magnet collimation only 55 mA is injected into the solenoid Low Energy Beam Transport (LEBT). A new purely electrostatic post-extraction system incorporating an einzel lens with an elliptical aperture is currently under test. This allows much greater flexibility of perveance and phase space matching for injection into the LEBT and Radio Frequency Quadrupole (RFQ). This paper discusses high voltage breakdown mitigation strategies and presents the first results of the novel elliptical transport system. So far, 70 mA of beam has been transported through the new system with a normalized transverse RMS emittance of 0.2 π mm mrad.

BBU and Corkscrew Growth Predictions for the Darht Second Axis Accelerator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Y.J.; Fawley, W.M.

2001-06-12

The second axis accelerator of the Dual Axis Radiographic Hydrodynamic Test (DARHT-II) facility will produce a 2-kA, 20-MeV, 2-{micro}s output electron beam with a design goal of less than 1000 {pi} mm-mrad normalized transverse emittance. In order to meet this goal, both the beam breakup instability (BBJ) and transverse corkscrew motion (due to chromatic phase advance) must be limited in growth. Using data from recent experimental measurements of the transverse impedance of actual DARHT-II accelerator cells by Briggs et al. [2], they have used the LLNL BREAKUP code to predict BBU and corkscrew growth in DARHT-II. The results suggest thatmore » BBU growth should not seriously degrade the final achievable spot size at the x-ray converter, presuming the initial excitation level is of the order 100 microns or smaller. For control of corkscrew growth, a major concern is the number of tuning shots needed to utilize effectively the tuning-V algorithm [3]. Presuming that the solenoid magnet alignment falls within spec, they believe that possibly as few as 50-100 shots will be necessary to set the dipole corrector magnet currents. They give some specific examples of tune determination for a hypothetical set of alignment errors.« less

BBU and Corkscrew Growth Predictions for the DARHT Second Axis Accelerator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Y J; Fawley, W M

2001-06-12

The second axis accelerator of the Dual Axis Radiographic Hydrodynamic Test (DARHT-II) facility will produce a 2-kA, 20-MeV, 2-{micro}s output electron beam with a design goal of less than 1000 {pi} mm-mrad normalized transverse emittance. In order to meet this goal, both the beam breakup instability (BBU) and transverse ''corkscrew'' motion (due to chromatic phase advance) must be limited in growth. Using data from recent experimental measurements of the transverse impedance of actual DARHT-II accelerator cells by Briggs et al., they have used the LLNL BREAKUP code to predict BBU and corkscrew growth in DARHT-II. The results suggest that BBUmore » growth should not seriously degrade the final achievable spot size at the x-ray converter, presuming the initial excitation level is of the order 100 microns or smaller. For control of corkscrew growth, a major concern is the number of ''tuning'' shots needed to utilize effectively the ''tuning-V'' algorithm. Presuming that the solenoid magnet alignment falls within spec, they believe that possibly as few as 50-100 shots will be necessary to set the dipole corrector magnet currents. They give some specific examples of tune determination for a hypothetical set of alignment errors.« less

A ultra-small-angle self-mixing sensor system with high detection resolution and wide measurement range

NASA Astrophysics Data System (ADS)

Yang, Bo; Wang, Dehui; Zhou, Lin; Wu, Shuang; Xiang, Rong; Zhang, Wenhua; Gui, Huaqiao; Liu, Jianguo; Wang, Huanqing; Lu, Liang; Yu, Benli

2017-06-01

The self-mixing technique based on the traditional reflecting mirror has been demonstrated with great merit for angle sensing applications. Here we demonstrate a modified self-reflection-mixing angle measurement system by combine a right-angle prism to self-mixing angle measurement. In our system, the wavelength is crucial to the angle measurement resolution. For a microchip solid-state laser, the measurement resolution can reach 0.49 mrad, while the resolution for the He-Ne laser is 0.53 mrad. In addition, the ranges in the system with the microchip solid-state laser and He-Ne laser are up to 22 mrad and 24.9 mrad respectively. This modified angle measurement system effectively combines the advantage of self-mixing measurement system with a compact structure, providing interesting features such as of high requisition of resolution and precision.

The new confocal heavy ion microprobe beamline at ANSTO: The first microprobe resolution tests and applications for elemental imaging and analysis

NASA Astrophysics Data System (ADS)

Pastuovic, Z.; Siegele, R.; Cohen, D. D.; Mann, M.; Ionescu, M.; Button, D.; Long, S.

2017-08-01

The Centre for Accelerator Science facility at ANSTO has been expanded with the new NEC 6 MV ;SIRIUS; accelerator system in 2015. In this paper we present a detailed description of the new nuclear microprobe-Confocal Heavy Ion Micro-Probe (CHIMP) together with results of the microprobe resolution testing and the elemental analysis performed on typical samples of mineral ore deposits and hyper-accumulating plants regularly measured at ANSTO. The CHIMP focusing and scanning systems are based on the OM-150 Oxford quadrupole triplet and the OM-26 separated scan-coil doublet configurations. A maximum ion rigidity of 38.9 amu-MeV was determined for the following nuclear microprobe configuration: the distance from object aperture to collimating slits of 5890 mm, the working distance of 165 mm and the lens bore diameter of 11 mm. The overall distance from the object to the image plane is 7138 mm. The CHIMP beamline has been tested with the 3 MeV H+ and 6 MeV He2+ ion beams. The settings of the object and collimating apertures have been optimized using the WinTRAX simulation code for calculation of the optimum acceptance settings in order to obtain the highest possible ion current for beam spot sizes of 1 μm and 5 μm. For optimized aperture settings of the CHIMP the beam brightness was measured to be ∼0.9 pA μm-2 mrad-2 for 3 MeV H+ ions, while the brightness of ∼0.4 pA μm-2 mrad-2 was measured for 6 MeV He2+ ions. The smallest beam sizes were achieved using a microbeam with reduced particle rate of 1000 Hz passing through the object slit apertures several micrometers wide. Under these conditions a spatial resolution of ∼0.6 μm × 1.5 μm for 3 MeV H+ and ∼1.8 μm × 1.8 μm for 6 MeV He2+ microbeams in horizontal (and vertical) dimension has been achieved. The beam sizes were verified using STIM imaging on 2000 and 1000 mesh Cu electron microscope grids.

Performance of a Drift Chamber Candidate for a Cosmic Muon Tomography System

NASA Astrophysics Data System (ADS)

Anghel, V.; Armitage, J.; Botte, J.; Boudjemline, K.; Bueno, J.; Bryman, D.; Charles, E.; Cousins, T.; Drouin, P.-L.; Erlandson, A.; Gallant, G.; Jewett, C.; Jonkmans, G.; Liu, Z.; Noel, S.; Oakham, G.; Stocki, T. J.; Thompson, M.; Waller, D.

2011-12-01

In the last decade, many groups around the world have been exploring different ways to probe transport containers which may contain illicit Special Nuclear Materials such as uranium. The muon tomography technique has been proposed as a cost effective system with an acceptable accuracy. A group of Canadian institutions (see above), funded by Defence Research and Development Canada, is testing different technologies to track the cosmic muons. One candidate is the single wire Drift Chamber. With the capability of a 2D impact position measurement, two detectors will be placed above and two below the object to be probed. In order to achieve a good 3D image quality of the cargo content, a good angular resolution is required. The simulation showed that 1mrad was required implying the spatial resolution of the trackers must be in the range of 1 to 2 mm for 1 m separation. A tracking system using three prototypes has been built and tested. The spatial resolution obtained is 1.7 mm perpendicular to the wire and 3 mm along the wire.

Next generation high-brightness diode lasers offer new industrial applications

NASA Astrophysics Data System (ADS)

Timmermann, Andre; Meinschien, Jens; Bruns, Peter; Burke, Colin; Bartoschewski, Daniel

2008-02-01

So far, diode laser systems could not compete against CO II-lasers or DPSSL in industrial applications like marking or cutting due to their lower brightness. Recent developments in high-brightness diode laser bars and beam forming systems with micro-optics have led to new direct diode laser applications. LIMO presents 400W output from a 200μm core fibre with an NA of 0.22 at one wavelength. This is achieved via the combination of newly designed laser diode bars on passive heat sinks coupled with optimized micro-optical beam shaping. The laser is water cooled with a housing size of 375mm x 265mm x 70mm. The applications for such diode laser modules are mainly in direct marking, cutting and welding of metals and other materials, but improved pumping of fibre lasers and amplifiers is also possible. The small spot size leads to extremely high intensities and therefore high welding speeds in cw operation. For comparison: The M2 of the fibre output is 70, which gives a comparable beam parameter product (22mm*mrad) to that of a CO II laser with a M2 of 7 because of the wavelength difference. Many metals have a good absorption within the wavelength range of the laser diodes (NIR, 808nm to 980nm), which permits the cutting of thin sheets of aluminium or steel with a 200W version of this laser. First welding tests show reduced splatters and pores owing to the optimized process behaviour in cw operation with short wavelengths. The availability of a top-hat profile proves itself to be advantageous compared to the traditional Gaussian beam profiles of fibre, solid-state and gas lasers in that the laser energy is evenly distributed over the working area. For the future, we can announce an increase of the output power up to 1200W out of a 200μm fibre (0.22 NA). This will be achieved by further sophistication and optimisation of the coupling technique and the coupling of three wavelengths. The beam parameter product will then remain at 22mm*mrad with a power density of 3.8 MW/cm2 if focussed to a 200µm spot. This leads to excellent laser cutting results with extremely small cutting kerfs down to 200μm and very plane cutting edges. Process speeds rise up to more than 10m/min i.e. for thin sheets of stainless steel or titanium.

Measurement of the muon beam direction and muon flux for the T2K neutrino experiment

NASA Astrophysics Data System (ADS)

Suzuki, K.; Aoki, S.; Ariga, A.; Ariga, T.; Bay, F.; Bronner, C.; Ereditato, A.; Friend, M.; Hartz, M.; Hiraki, T.; Ichikawa, A. K.; Ishida, T.; Ishii, T.; Juget, F.; Kikawa, T.; Kobayashi, T.; Kubo, H.; Matsuoka, K.; Maruyama, T.; Minamino, A.; Murakami, A.; Nakadaira, T.; Nakaya, T.; Nakayoshi, K.; Otani, M.; Oyama, Y.; Patel, N.; Pistillo, C.; Sakashita, K.; Sekiguchi, T.; Suzuki, S. Y.; Tada, S.; Yamada, Y.; Yamamoto, K.; Yokoyama, M.

2015-05-01

The Tokai-to-Kamioka (T2K) neutrino experiment measures neutrino oscillations by using an almost pure muon neutrino beam produced at the J-PARC accelerator facility. The T2K muon monitor was installed to measure the direction and stability of the muon beam which is produced in conjunction with the muon neutrino beam. The systematic error in the muon beam direction measurement was estimated, using data and MC simulation, to be 0.28 mrad. During beam operation, the proton beam has been controlled using measurements from the muon monitor and the direction of the neutrino beam has been tuned to within 0.3 mrad with respect to the designed beam-axis. In order to understand the muon beam properties, measurement of the absolute muon yield at the muon monitor was conducted with an emulsion detector. The number of muon tracks was measured to be (4.06± 0.05± 0.10)× 10^4cm^{-2} normalized with 4× 10^{11} protons on target with 250 kA horn operation. The result is in agreement with the prediction, which is corrected based on hadron production data.

Allograft tissue irradiation and failure rate after anterior cruciate ligament reconstruction: A systematic review.

PubMed

Dashe, Jesse; Parisien, Robert L; Cusano, Antonio; Curry, Emily J; Bedi, Asheesh; Li, Xinning

2016-06-18

To evaluate whether anterior cruciate ligament (ACL) allograft irradiation is effective for sterility without compromising graft integrity and increasing failure rate. A literature search was conducted using PubMed, Cochrane, and Google. The following search terms were used: "Gamma irradiation AND anterior cruciate ligament AND allograft" with a return of 30 items. Filters used included: English language, years 1990-2015. There were 6 hits that were not reviewed, as there were only abstracts available. Another 5 hits were discarded, as they did not pertain to the topic of interest. There were 9 more articles that were excluded: Three studies were performed on animals and 6 studies were meta-analyses. Therefore, a total of 10 articles were applicable to review. There is a delicate dosing crossover where gamma irradiation is both effective for sterility without catastrophically compromising the structural integrity of the graft. Of note, low dose irradiation is considered less than 2.0 Mrad, moderate dose is between 2.1-2.4 Mrad, and high dose is greater than or equal to 2.5 Mrad. Based upon the results of the literature search, the optimal threshold for sterilization was found to be sterilization at less than 2.2 Mrad of gamma irradiation with the important caveat of being performed at low temperatures. The graft selection process also must include thorough donor screening and testing as well as harvesting the tissue in a sterile fashion. Utilization of higher dose (≥ 2.5 Mrad) of irradiation causes greater allograft tissue laxity that results in greater graft failure rate clinically in patients after ACL reconstruction. Allograft ACL graft gamma irradiated with less than 2.2 Mrad appears to be a reasonable alternative to autograft for patients above 25 years of age.

Allograft tissue irradiation and failure rate after anterior cruciate ligament reconstruction: A systematic review

PubMed Central

Dashe, Jesse; Parisien, Robert L; Cusano, Antonio; Curry, Emily J; Bedi, Asheesh; Li, Xinning

2016-01-01

AIM: To evaluate whether anterior cruciate ligament (ACL) allograft irradiation is effective for sterility without compromising graft integrity and increasing failure rate. METHODS: A literature search was conducted using PubMed, Cochrane, and Google. The following search terms were used: “Gamma irradiation AND anterior cruciate ligament AND allograft” with a return of 30 items. Filters used included: English language, years 1990-2015. There were 6 hits that were not reviewed, as there were only abstracts available. Another 5 hits were discarded, as they did not pertain to the topic of interest. There were 9 more articles that were excluded: Three studies were performed on animals and 6 studies were meta-analyses. Therefore, a total of 10 articles were applicable to review. RESULTS: There is a delicate dosing crossover where gamma irradiation is both effective for sterility without catastrophically compromising the structural integrity of the graft. Of note, low dose irradiation is considered less than 2.0 Mrad, moderate dose is between 2.1-2.4 Mrad, and high dose is greater than or equal to 2.5 Mrad. Based upon the results of the literature search, the optimal threshold for sterilization was found to be sterilization at less than 2.2 Mrad of gamma irradiation with the important caveat of being performed at low temperatures. The graft selection process also must include thorough donor screening and testing as well as harvesting the tissue in a sterile fashion. Utilization of higher dose (≥ 2.5 Mrad) of irradiation causes greater allograft tissue laxity that results in greater graft failure rate clinically in patients after ACL reconstruction. CONCLUSION: Allograft ACL graft gamma irradiated with less than 2.2 Mrad appears to be a reasonable alternative to autograft for patients above 25 years of age. PMID:27335815

Invasive Cardiologists Are Exposed to Greater Left Sided Cranial Radiation: The BRAIN Study (Brain Radiation Exposure and Attenuation During Invasive Cardiology Procedures).

PubMed

Reeves, Ryan R; Ang, Lawrence; Bahadorani, John; Naghi, Jesse; Dominguez, Arturo; Palakodeti, Vachaspathi; Tsimikas, Sotirios; Patel, Mitul P; Mahmud, Ehtisham

2015-08-17

This study sought to determine radiation exposure across the cranium of cardiologists and the protective ability of a nonlead, XPF (barium sulfate/bismuth oxide) layered cap (BLOXR, Salt Lake City, Utah) during fluoroscopically guided, invasive cardiovascular (CV) procedures. Cranial radiation exposure and potential for protection during contemporary invasive CV procedures is unclear. Invasive cardiologists wore an XPF cap with radiation attenuation ability. Six dosimeters were fixed across the outside and inside of the cap (left, center, and right), and 3 dosimeters were placed outside the catheterization lab to measure ambient exposure. Seven cardiology fellows and 4 attending physicians (38.4 ± 7.2 years of age; all male) performed diagnostic and interventional CV procedures (n = 66.2 ± 27 cases/operator; fluoroscopy time: 14.9 ± 5.0 min). There was significantly greater total radiation exposure at the outside left and outside center (106.1 ± 33.6 mrad and 83.1 ± 18.9 mrad) versus outside right (50.2 ± 16.2 mrad; p < 0.001 for both) locations of the cranium. The XPF cap attenuated radiation exposure (42.3 ± 3.5 mrad, 42.0 ± 3.0 mrad, and 41.8 ± 2.9 mrad at the inside left, inside center, and inside right locations, respectively) to a level slightly higher than that of the ambient control (38.3 ± 1.2 mrad, p = 0.046). After subtracting ambient radiation, exposure at the outside left was 16 times higher than the inside left (p < 0.001) and 4.7 times higher than the outside right (p < 0.001). Exposure at the outside center location was 11 times higher than the inside center (p < 0.001), whereas no difference was observed on the right side. Radiation exposure to invasive cardiologists is significantly higher on the left and center compared with the right side of the cranium. Exposure may be reduced similar to an ambient control level by wearing a nonlead XPF cap. (Brain Radiation Exposure and Attenuation During Invasive Cardiology Procedures [BRAIN]; NCT01910272). Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Ultralow emittance, multi-MeV proton beams from a laser virtual-cathode plasma accelerator.

PubMed

Cowan, T E; Fuchs, J; Ruhl, H; Kemp, A; Audebert, P; Roth, M; Stephens, R; Barton, I; Blazevic, A; Brambrink, E; Cobble, J; Fernández, J; Gauthier, J-C; Geissel, M; Hegelich, M; Kaae, J; Karsch, S; Le Sage, G P; Letzring, S; Manclossi, M; Meyroneinc, S; Newkirk, A; Pépin, H; Renard-LeGalloudec, N

2004-05-21

The laminarity of high-current multi-MeV proton beams produced by irradiating thin metallic foils with ultraintense lasers has been measured. For proton energies >10 MeV, the transverse and longitudinal emittance are, respectively, <0.004 mm mrad and <10(-4) eV s, i.e., at least 100-fold and may be as much as 10(4)-fold better than conventional accelerator beams. The fast acceleration being electrostatic from an initially cold surface, only collisions with the accelerating fast electrons appear to limit the beam laminarity. The ion beam source size is measured to be <15 microm (FWHM) for proton energies >10 MeV.

Laser-photofield emission from needle cathodes for low-emittance electron beams.

PubMed

Ganter, R; Bakker, R; Gough, C; Leemann, S C; Paraliev, M; Pedrozzi, M; Le Pimpec, F; Schlott, V; Rivkin, L; Wrulich, A

2008-02-15

Illumination of a ZrC needle with short laser pulses (16 ps, 266 nm) while high voltage pulses (-60 kV, 2 ns, 30 Hz) are applied, produces photo-field emitted electron bunches. The electric field is high and varies rapidly over the needle surface so that quantum efficiency (QE) near the apex can be much higher than for a flat photocathode due to the Schottky effect. Up to 150 pC (2.9 A peak current) have been extracted by photo-field emission from a ZrC needle. The effective emitting area has an estimated radius below 50 microm leading to a theoretical intrinsic emittance below 0.05 mm mrad.

Picosecond excimer laser-plasma x-ray source for microscopy, biochemistry, and lithography

NASA Astrophysics Data System (ADS)

Turcu, I. C. Edmond; Ross, Ian N.; Trenda, P.; Wharton, C. W.; Meldrum, R. A.; Daido, Hiroyuki; Schulz, M. S.; Fluck, P.; Michette, Alan G.; Juna, A. P.; Maldonado, Juan R.; Shields, Harry; Tallents, Gregory J.; Dwivedi, L.; Krishnan, J.; Stevens, D. L.; Jenner, T.; Batani, Dimitri; Goodson, H.

1994-02-01

At Rutherford Appleton Laboratory we developed a high repetition rate, picosecond, excimer laser system which generates a high temperature and density plasma source emitting approximately 200 mW (78 mW/sr) x ray average power at h(nu) approximately 1.2 KeV or 0.28 KeV < h(nu) < 0.53 KeV (the `water window'). At 3.37 nm wavelength the spectral brightness of the source is approximately 9 X 1011 photons/s/mm2/mrad2/0.1% bandwidth. The x-ray source serves a large user community for applications such as: scanning and holographic microscopy, the study of the biochemistry of DNA damage and repair, microlithography and spectroscopy.

Barrel calorimeter of the CMD-3 detector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shebalin, V. E., E-mail: V.E.Shebalin@inp.nsk.su; Anisenkov, A. V.; Aulchenko, V. M.

The structure of the barrel calorimeter of the CMD-3 detector is presented in this work. The procedure of energy calibration of the calorimeter and the method of photon energy restoration are described. The distinctive feature of this barrel calorimeter is its combined structure; it is composed of two coaxial subsystems: a liquid xenon calorimeter and a crystalline CsI calorimeter. The calorimeter spatial resolution of the photon conversion point is about 2 mm, which corresponds to an angular resolution of ∼6 mrad. The energy resolution of the calorimeter is about 8% for photons with energy of 200 MeV and 4% formore » photons with energy of 1 GeV.« less

A fiber-coupled 9xx module with tap water cooling

NASA Astrophysics Data System (ADS)

Schleuning, D.; Anthon, D.; Chryssis, A.; Ryu, G.; Liu, G.; Winhold, H.; Fan, L.; Xu, Z.; Tanbun-Ek, T.; Lehkonen, S.; Acklin, B.

2016-03-01

A novel, 9XX nm fiber-coupled module using arrays of highly reliable laser diode bars has been developed. The module is capable of multi-kW output power in a beam parameter product of 80 mm-mrad. The module incorporates a hard-soldered, isolated stack package compatible with tap-water cooling. Using extensive, accelerated multi-cell life-testing, with more than ten million device hours of test, we have demonstrated a MTTF for emitters of >500,000 hrs. In addition we have qualified the module in hard-pulse on-off cycling and stringent environmental tests. Finally we have demonstrated promising results for a next generation 9xx nm chip design currently in applications and qualification testing

Topography-coupled resonance between Mars normal-modes and the tidal force of the Phobos

NASA Astrophysics Data System (ADS)

Tian, Y.; Zheng, Y.

2016-12-01

Phobos is the largest moon of Mars. The gravity attraction of Phobos to Mars is a periodic force, which may excite seismic waves inside Mars. Since Phobos is below the synchronous orbit, its orbit is continuously decreasing due to the tidal effect. This will result in a monotonic increase in its orbital frequency, which may eventually intrude into the seismic normal-mode frequency range to cause resonance. The objective of this research is to investigate whether such a resonance phenomenon can occur and what the consequence is. As we know, resonance happens when the periodic tidal force has a similar frequency as that of martian normal modes. It can be shown that such a resonance will not occur if Mars is perfectly spherical because the tidal force can only excite modes of the same angular order. For the same angular order, the tidal force frequencies are always smaller than those of the normal modes. However, when we consider the effect of topography of Mars, the resonance can occur because of coupling of normal modes. We use numerical method to calculate when the resonance will occur. We firstly solve for the normal modes of Mars by idealizing it as a solid elastic sphere. At the second step, we calculate the excitation effect of gravitational force from Phobos on each individual normal mode. For example, the gravity tidal force F at L=5, m=5 F55 can excite a normal mode 0S5 which can be coupled to 0T2. The third step is to calculate the frequency that the resonance will happen. For example, when the rotation frequency of Phobos increase to 0.8 mRad/s, the tidal force at L=5, m=5 can reach 4mRad/s which is the eigen-frequency of 0T2. Since we have calculated the coupling factors between each individual mode, the amplitude coefficients can be solved by a linear equation. We can observe a 100 times of amplitude increase of mode 0T2, which convince us the resonance will happen. The resonance may cause large amplitude of ground vibration of Mars. From our calculation, when the resonance happen, the energy dissipation rate will be greatly increased, which will make Phobos falling much faster. Eventually, Phobos will hit Mars in a very short time. Our research may give us a new prospective on early formation of planets.

The Mars Science Laboratory Curiosity rover Mastcam instruments: Preflight and in-flight calibration, validation, and data archiving

USGS Publications Warehouse

Bell, James F.; Godber, A.; McNair, S.; Caplinger, M.A.; Maki, J.N.; Lemmon, M.T.; Van Beek, J.; Malin, M.C.; Wellington, D.; Kinch, K.M.; Madsen, M.B.; Hardgrove, C.; Ravine, M.A.; Jensen, E.; Harker, D.; Anderson, Ryan; Herkenhoff, Kenneth E.; Morris, R.V.; Cisneros, E.; Deen, R.G.

2017-01-01

The NASA Curiosity rover Mast Camera (Mastcam) system is a pair of fixed-focal length, multispectral, color CCD imagers mounted ~2 m above the surface on the rover's remote sensing mast, along with associated electronics and an onboard calibration target. The left Mastcam (M-34) has a 34 mm focal length, an instantaneous field of view (IFOV) of 0.22 mrad, and a FOV of 20° × 15° over the full 1648 × 1200 pixel span of its Kodak KAI-2020 CCD. The right Mastcam (M-100) has a 100 mm focal length, an IFOV of 0.074 mrad, and a FOV of 6.8° × 5.1° using the same detector. The cameras are separated by 24.2 cm on the mast, allowing stereo images to be obtained at the resolution of the M-34 camera. Each camera has an eight-position filter wheel, enabling it to take Bayer pattern red, green, and blue (RGB) “true color” images, multispectral images in nine additional bands spanning ~400–1100 nm, and images of the Sun in two colors through neutral density-coated filters. An associated Digital Electronics Assembly provides command and data interfaces to the rover, 8 Gb of image storage per camera, 11 bit to 8 bit companding, JPEG compression, and acquisition of high-definition video. Here we describe the preflight and in-flight calibration of Mastcam images, the ways that they are being archived in the NASA Planetary Data System, and the ways that calibration refinements are being developed as the investigation progresses on Mars. We also provide some examples of data sets and analyses that help to validate the accuracy and precision of the calibration

Generating a high brightness multi-kilowatt laser by dense spectral combination of VBG stabilized single emitter laser diodes

NASA Astrophysics Data System (ADS)

Fritsche, H.; Koch, Ralf; Krusche, B.; Ferrario, F.; Grohe, Andreas; Pflueger, S.; Gries, W.

2014-05-01

Generating high power laser radiation with diode lasers is commonly realized by geometrical stacking of diode bars, which results in high output power but poor beam parameter product (BPP). The accessible brightness in this approach is limited by the fill factor, both in slow and fast axis. By using a geometry that accesses the BPP of the individual diodes, generating a multi kilowatt diode laser with a BPP comparable to fiber lasers is possible. We will demonstrate such a modular approach for generating multi kilowatt lasers by combining single emitter diode lasers. Single emitter diodes have advantages over bars, mainly a simplified cooling, better reliability and a higher brightness per emitter. Additionally, because single emitters can be arranged in many different geometries, they allow building laser modules where the brightness of the single emitters is preserved. In order to maintain the high brightness of the single emitter we developed a modular laser design which uses single emitters in a staircase arrangement, then coupling two of those bases with polarization combination which is our basic module. Those modules generate up to 160 W with a BPP better than 7.5 mm*mrad. For further power scaling wavelength stabilization is crucial. The wavelength is stabilized with only one Volume Bragg Grating (VBG) in front of a base providing the very same feedback to all of the laser diodes. This results in a bandwidth of < 0.5 nm and a wavelength stability of better than 250 MHz over one hour. Dense spectral combination with dichroic mirrors and narrow channel spacing allows us to combine multiple wavelength channels, resulting in a 2 kW laser module with a BPP better than 7.5 mm*mrad, which can easily coupled into a 100 μm fiber and 0.15 NA.

Highly modular high-brightness diode laser system design for a wide application range

NASA Astrophysics Data System (ADS)

Fritsche, Haro; Kruschke, Bastian; Koch, Ralf; Ferrario, Fabio; Kern, Holger; Pahl, Ullrich; Ehm, Einar; Pflueger, Silke; Grohe, Andreas; Gries, Wolfgang

2015-03-01

For an economic production it is important to serve as many applications as possible while keeping the product variations minimal. We present our modular laser design, which is based on single emitters and various combining technics. In a first step we accept a reduction of the very high brightness of the single emitters by vertical stacking. Those emitters can be wavelength stabilized by an external resonator, providing the very same feedback to each of those laser diodes which leads to an output power of about 100W with BPP of <3.5 mm*mrad (FA) and <5 mm*mrad (SA). Further power scaling is accomplished by polarization and wavelength multiplexing yielding high optical efficiencies of more than 80% and results in about 500 W launched into a 100 μm fiber with 0.15 NA. Subsequently those building blocks can be stacked also by the very same dense spectral combing technique up to multi kW Systems without further reduction of the BPP. These "500W building blocks" are consequently designed in a way that without any system change new wavelengths can be implemented by only exchanging parts but without change of the production process. This design principal offers the option to adapt the wavelength of those blocks to any applications, from UV, visible into the far IR. From laser pumping and scientific applications to materials processing such as cutting and welding of copper aluminum or steel and also medical application. Operating at wavelengths between 900 nm and 1100 nm, these systems are mainly used in cutting and welding, but the technology can also be adapted to other wavelength ranges, such as 793 nm and 1530 nm. Around 1.5 μm the diodes are already successfully used for resonant pumping of Erbium lasers.[1] Furthermore, the fully integrated electronic concept allows addressing further applications, as it is capable of very short μs pulses up to cw mode operation by simple software commands.

Enhanced Low Dose Rate Sensitivity at Ultra-Low Dose Rates

NASA Technical Reports Server (NTRS)

Chen, Dakai; Pease, Ronald; Forney, James; Carts, Martin; Phan, Anthony; Cox, Stephen; Kruckmeyer, Kriby; Burns, Sam; Albarian, Rafi; Holcombe, Bruce;

A high brightness proton injector for the Tandetron accelerator at Jožef Stefan Institute

NASA Astrophysics Data System (ADS)

Pelicon, Primož; Podaru, Nicolae C.; Vavpetič, Primož; Jeromel, Luka; Ogrinc Potocnik, Nina; Ondračka, Simon; Gottdang, Andreas; Mous, Dirk J. M.

2014-08-01

Jožef Stefan Institute recently commissioned a high brightness H- ion beam injection system for its existing tandem accelerator facility. Custom developed by High Voltage Engineering Europa, the multicusp ion source has been tuned to deliver at the entrance of the Tandetron™ accelerator H- ion beams with a measured brightness of 17.1 A m-2 rad-2 eV-1 at 170 μA, equivalent to an energy normalized beam emittance of 0.767 π mm mrad MeV1/2. Upgrading the accelerator facility with the new injection system provides two main advantages. First, the high brightness of the new ion source enables the reduction of object slit aperture and the reduction of acceptance angle at the nuclear microprobe, resulting in a reduced beam size at selected beam intensity, which significantly improves the probe resolution for micro-PIXE applications. Secondly, the upgrade strongly enhances the accelerator up-time since H and He beams are produced by independent ion sources, introducing a constant availability of 3He beam for fusion-related research with NRA. The ion beam particle losses and ion beam emittance growth imply that the aforementioned beam brightness is reduced by transport through the ion optical system. To obtain quantitative information on the available brightness at the high-energy side of the accelerator, the proton beam brightness is determined in the nuclear microprobe beamline. Based on the experience obtained during the first months of operation for micro-PIXE applications, further necessary steps are indicated to obtain optimal coupling of the new ion source with the accelerator to increase the normalized high-energy proton beam brightness at the JSI microprobe, currently at 14 A m-2 rad-2 eV-1, with the output current at 18% of its available maximum.

Detoxification of Salmonella typhimurium lipopolysaccharide by ionizing radiation.

PubMed

Previte, J J; Chang, Y; el-Bisi, H M

1967-05-01

The efficiency of ionizing radiation in detoxifying the lethal determinant(s) of the lipopolysaccharide (LPS) of Salmonella typhimurium, S. enteritidis, and Escherichia coli in aqueous solution and associated with heat-killed S. typhimurium cells in suspension decreased with doses above 1 Mrad. The 50% end point of inactivation was more than 7.0 Mrad for heat-killed salmonellae and 4.8, 4.5, and 1.0 Mrad for the LPS of S. typhimurium, S. enteritidis, and E. coli, respectively. After exposure to 20 Mrad, S. typhimurium LPS retained a small portion of its lethal properties although the ld(50) was much greater than 9.5 mg per 20-g mouse. However, at -184 C, no inactivation of the lethal determinant(s) occurred after exposure to as much as 20 Mrad. This demonstrated the significance of the indirect effect and the mobility and formation of free radicals. At 22 C, the optical density at 400 mmu increased and the pH decreased with increasing radiation dose, but no qualitative changes were observed in the infrared spectrum. No change was observed in the pyrogenicity of S. typhimurium LPS; a slight decrease in antigenicity was revealed when 6 days, but not when 1 day, elapsed between vaccination and challenge in the mouse protection test. The results were interpreted as evidence of the existence of two or more lethal and antigenic determinants. The differential effect of radiation on these properties and on the pyrogenic component(s) probably are indicative of separate functional sites for lethal, antigenic, and pyrogenic activities.

In vitro biocompatibility of EPM and EPDM rubbers.

PubMed

Mast, F; Hoschtitzky, J A; Van Blitterswijk, C A; Huysmans, H A

1997-01-01

The in vitro toxicity of two EPDM rubbers (K 778 and K 4802) and one EPM rubber (K 740) was tested using human fibroblasts. The modulus of elasticity of each rubber was varied by exposure to different amounts of electron-beam radiation (0, 5 and 10 Mrad). The short-term in vitro toxicity was tested by culturing cells on polymer films. The long-term effect of ageing was simulated by growing fibroblasts in nutrient media prepared from extracts of heat-exposed materials. Cell cultures were studied both quantitatively and (ultra) structurally. Growth curves obtained in the toxicity test did not differ significantly from control values at any day of observation, and also showed that electron-beam radiation did not alter the biocompatibility. The same results were found for all but one material in the artificial ageing test. The number of cells in the K4802/10 Mrad extraction medium was decreased. Ultrastructurally no gross deviations from normal morphology were observed, either in the direct contact test or in the artificial ageing test. The most characteristic feature was a somewhat dilated endoplasmic reticulum. In summary, the in vitro biocompatibility of EPDM-rubbers as observed in this study is satisfactory and motivates further investigation of their biocompatibility in animal experiments.

In-orbit verification of MHS spectral channels co-registration using the moon

NASA Astrophysics Data System (ADS)

Bonsignori, Roberto

2017-09-01

In-orbit verification of the co-registration of channels in a scanning microwave or infrared radiometer can in principle be done during normal in-orbit operation, by using the regular events of lunar intrusion in the instrument cold space calibration view. A technique of data analysis based on best fit of data across lunar intrusions has been used to check the mutual alignment of the spectral channels of the MHS instrument. MHS (Microwave Humidity Sounder) is a cross-track scanning radiometer in the millimetre-wave range flying on EUMETSAT and NOAA polar satellites, used operationally for the retrieval of atmospheric parameters in numerical weather prediction and nowcasting. This technique does not require any special operation or manoeuvre and only relies on analysis of data from the nominal scanning operation. The co-alignment of sounding channels and window channels can be evaluated by this technique, which would not be possible by using earth landmarks, due to the absorption effect of the atmosphere. The analysis reported in this paper shows an achievable accuracy below 0.5 mrad against a beam width at 3dB and spatial sampling interval of about 20 mrad. In-orbit results for the MHS instrument on Metop-B are also compared with the pre-launch instrument characterisation, showing a good correlation.

Noise performance of 0.35-(mu)m SOI CMOS devices and micropower preamplifier following 63-MeV, 1-Mrad (Si) proton irradiation

NASA Technical Reports Server (NTRS)

Binkley, D. M.; Hopper, C. E.; Cressler, J. D.; Mojarradi, M. M.; Blalock, B. J.

2004-01-01

This paper presents measured noise for 0.35(mu)m, silicon-on-insulator devices and a micropower preamplifier following 63-MeV, 1-Mrad (Si) proton irradiation. Flicker noise voltage, important for gyros having low frequency output, increases less than 32% after irradiation.

Plane Systems for Irradiation of a Patient from Any Directions

NASA Astrophysics Data System (ADS)

Kats, M. M.; Onossovsky, K. K.

1997-05-01

The system for transportation of a beam used for proton therapy is suggested. In this system a prone patient is placed perpendicularly to the beam axis. The beam is bent and focused in the vertical plane in such a way that makes possible patient irradiation from any direction. Three versions of such a system are discussed. All of them give the opportunity to transport protons with energy up to 250 MeV and R*R' up to 10-5 m*rad to targets with linear size in the interval between 10 and 300 mm. As compared to systems described earlier (GANTRY, Corcscrew etc.) the systems described in this paper have smaller weight of movable equipment, occupy less space and consume less power. Coauthor deseased

Backward pumping kilowatt Yb3+-doped double-clad fiber laser

NASA Astrophysics Data System (ADS)

Han, Z. H.; Lin, X. C.; Hou, W.; Yu, H. J.; Zhou, S. Z.; Li, J. M.

2011-09-01

A ytterbium-doped double-clad fiber laser generating up to 1026 W of continuous-wave output power at 1085 nm with a slope efficiency of 74% by single-ended backward pumping configuration is reported. The core diameter was 20 μm with a low numerical aperture of 0.06, and a good beam quality (BPP < 1.8 mm mrad) is achieved without special mode selection methods. No undesirable roll-over was observed in output power with increasing pump power, and the maximum output power was limited by the available pump power. The instability of maximum output power was better than ±0.6%. Different pumping configurations were also compared in experiment, which shows good agreements with theoretical analyses.

Emittance of positron beams produced in intense laser plasma interaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen Hui; Hazi, A.; Link, A.

2013-01-15

The first measurement of the emittance of intense laser-produced positron beams has been made. The emittance values were derived through measurements of positron beam divergence and source size for different peak positron energies under various laser conditions. For one of these laser conditions, we used a one dimensional pepper-pot technique to refine the emittance value. The laser-produced positrons have a geometric emittance between 100 and 500 mm{center_dot}mrad, comparable to the positron sources used at existing accelerators. With 10{sup 10}-10{sup 12} positrons per bunch, this low emittance beam, which is quasi-monoenergetic in the energy range of 5-20 MeV, may be usefulmore » as an alternative positron source for future accelerators.« less

Wavefront image sensor chip

PubMed Central

Cui, Xiquan; Ren, Jian; Tearney, Guillermo J.; Yang, Changhuei

2010-01-01

We report the implementation of an image sensor chip, termed wavefront image sensor chip (WIS), that can measure both intensity/amplitude and phase front variations of a light wave separately and quantitatively. By monitoring the tightly confined transmitted light spots through a circular aperture grid in a high Fresnel number regime, we can measure both intensity and phase front variations with a high sampling density (11 µm) and high sensitivity (the sensitivity of normalized phase gradient measurement is 0.1 mrad under the typical working condition). By using WIS in a standard microscope, we can collect both bright-field (transmitted light intensity) and normalized phase gradient images. Our experiments further demonstrate that the normalized phase gradient images of polystyrene microspheres, unstained and stained starfish embryos, and strongly birefringent potato starch granules are improved versions of their corresponding differential interference contrast (DIC) microscope images in that they are artifact-free and quantitative. Besides phase microscopy, WIS can benefit machine recognition, object ranging, and texture assessment for a variety of applications. PMID:20721059

21 CFR 579.40 - Ionizing radiation for the treatment of poultry feed and poultry feed ingredients.

Code of Federal Regulations, 2012 CFR

2012-04-01

..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IRRADIATION IN... (Mrad)); maximum dose 25 kGy (2.5 megarads Mrad). The absorbed dose of irradiation is to be based on... concentration by one log cycle (one decimal reduction). (2) Feeds treated by irradiation should be formulated to...

21 CFR 579.40 - Ionizing radiation for the treatment of poultry feed and poultry feed ingredients.

Code of Federal Regulations, 2011 CFR

2011-04-01

..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IRRADIATION IN... (Mrad)); maximum dose 25 kGy (2.5 megarads Mrad). The absorbed dose of irradiation is to be based on... concentration by one log cycle (one decimal reduction). (2) Feeds treated by irradiation should be formulated to...

21 CFR 579.40 - Ionizing radiation for the treatment of poultry feed and poultry feed ingredients.

Code of Federal Regulations, 2010 CFR

2010-04-01

..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IRRADIATION IN... (Mrad)); maximum dose 25 kGy (2.5 megarads Mrad). The absorbed dose of irradiation is to be based on... concentration by one log cycle (one decimal reduction). (2) Feeds treated by irradiation should be formulated to...

21 CFR 579.40 - Ionizing radiation for the treatment of poultry feed and poultry feed ingredients.

Code of Federal Regulations, 2013 CFR

2013-04-01

..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IRRADIATION IN... (Mrad)); maximum dose 25 kGy (2.5 megarads Mrad). The absorbed dose of irradiation is to be based on... concentration by one log cycle (one decimal reduction). (2) Feeds treated by irradiation should be formulated to...

Chemical Sensitization of Clostridium botulinum Spores to Radiation in Meat1

PubMed Central

Krabbenhoft, K. L.; Corlett, D. A.; Anderson, A. W.; Elliker, P. R.

1964-01-01

Beef ground round inoculated with 1,000,000 spores of Clostridium botulinum 33-A per gram and containing various additives was exposed to gamma radiation. Spores were inactivated in samples (irradiated at 2.0, 2.5, and 3.0 Mrad) which contained sodium nitrate (1,000 ppm) plus sodium chloride (2.5%). Similar results were obtained when sodium nitrite (200 ppm) was substituted for sodium nitrate, except that there was evidence of spore survival in 1 of 120 cans irradiated at 2.0 Mrad. Spore destruction was based upon the absence of spores and mouse-lethal toxin in meat subcultures made from cans incubated at 35 C for 120 days. Spores were not destroyed when exposed to 2.5 or 3.0 Mrad in the absence of sodium nitrate, sodium nitrite, or sodium chloride. Furthermore, the use of these chemicals individually, together with radiation, was ineffective. The additives alone in the absence of radiation also did not cause spore destruction. Radiation levels of 2.0, 2.5, and 3.0 Mrad, when used with sodium chloride at 1.5 or 2.0% and sodium nitrate at 500 ppm or sodium nitrite at 100 ppm, were ineffective. PMID:14215973

Gamma processing of Arabic bread for immune system-compromised cancer patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grecz, N.; Brannon, R.; Jaw, R.

Arabic bread prepared from local Saudi flour contained a total of up to 105/sup 4/ organisms per g. Most of these were bacterial spores that survived the baking process (1.3 x 10/sup 2/ to 3.5 x 10/sup 3/) and a small number of yeasts and molds (10 to 40 cells per g). The organisms in Arabic bread appear to be harmless to healthy individuals. However, for immune system-compromised cancer patients and bone marrow transplant recipients, it is prudent to irradiate the bread to reduce microbial contamination. The decimal reduction doses (10% survival) for the most radiation-resistant organisms (spore formers) inmore » bread were 0.11 to 0.15 Mrad. Accordingly, 0.6 Mrad was sufficient to reduce the number of spores in Arabic bread by a factor of 10,000, i.e., to <1/g. This treatment constitutes radiation pasteurization (radicidation), and to this extent, provides a margin of microbiological safety. Sensory evaluation by the nine-point hedonic scale showed no detectable loss of organoleptic quality of bread up to 0.6 Mrad, while irradiation to 2.5 Mrad induced unacceptable organoleptic changes.« less

A homogeneous focusing system for diode lasers and its applications in metal surface modification

NASA Astrophysics Data System (ADS)

Wang, Fei; Zhong, Lijing; Tang, Xiahui; Xu, Chengwen; Wan, Chenhao

2018-06-01

High power diode lasers are applied in many different areas, including surface modification, welding and cutting. It is an important technical trend in laser processing of metals in the future. This paper aims to analyze the impact of the shape and homogeneity of the focal spot of the diode laser on surface modification. A focusing system using the triplet lenses for a direct output diode laser which can be used to eliminate coma aberrations is studied. A rectangular stripe with an aspect ratio from 8:1 to 25:1 is obtained, in which the power is homogeneously distributed along the fast axis, the power is 1117.6 W and the peak power intensity is 1.1587 × 106 W/cm2. This paper also presents a homogeneous focusing system by use of a Fresnel lens, in which the incident beam size is 40 × 40 mm2, the focal length is 380 mm, and the dimension of the obtained focal spot is 2 × 10 mm2. When the divergence angle of the incident light is in the range of 12.5-20 mrad and the pitch is 1 mm, the obtained homogeneity in the focal spot is the optimum (about 95.22%). Experimental results show that the measured focal spot size is 2.04 × 10.39 mm2. This research presents a novel design of homogeneous focusing systems for high power diode lasers.

Specialty flat-top beam delivery fibers with controlled beam parameter product

NASA Astrophysics Data System (ADS)

Jollivet, C.; Farley, K.; Conroy, M.; Abramczyk, J.; Belke, S.; Becker, F.; Tankala, K.

2016-03-01

Beam delivery fibers have been used widely for transporting the optical beams from the laser to the subject of irradiation in a variety of markets including industrial, medical and defense applications. Standard beam delivery fibers range from 50 to 1500 μm core diameter and are used to guide CW or pulsed laser light, generated by solid state, fiber or diode lasers. Here, we introduce a novel fiber technology capable of simultaneously controlling the beam profile and the angular divergence of single-mode (SM) and multi-mode (MM) beams using a single-optical fiber. Results of beam transformation from a SM to a MM beam with flat-top intensity profile are presented in the case of a controlled BPP at 3.8 mm*mrad. The scaling capabilities of this flat-top fiber design to achieve a range of BPP values while ensuring a flat-top beam profile are discussed. In addition, we demonstrate, for the first time to the best of our knowledge, the homogenizer capabilities of this novel technology, able to transform random MM beams into uniform flat-top beam profiles with very limited impact on the beam brightness. This study is concluded with a discussion on the scalability of this fiber technology to fit from 50 up to 1500 μm core fibers and its potential for a broader range of applications.

Inertial drives for micro- and nanorobots: two novel mechanisms

NASA Astrophysics Data System (ADS)

Zesch, Wolfgang; Buechi, Roland; Codourey, Alain; Siegwart, Roland Y.

1995-12-01

In micro or nanorobotics, high precision movement in two or more degrees of freedom is one of the main problems. Firstly, the positional precision has to be increased (< 10 nm) as the object sizes decrease. On the other hand, the workspace has to have macroscopic dimensions (1 cm3) to give high maneuverability to the system and to allow suitable handling at the micro/macro-world interface. As basic driving mechanisms for the ETHZ Nanorobot Project, two new piezoelectric devices have been developed. `Abalone' is a 3-dof system that relies on the impact drive principle. The 38 mm X 33 mm X 9 mm slider can be moved to each position and orientation in a horizontal plane within a theoretically infinite workspace. In the stepping mode it achieves a speed of 1 mm/s in translation and 7 deg/s in rotation. Within the actuator's local range of 6 micrometers fine positioning is possible with a resolution better than 10 nm. `NanoCrab' is a bearingless rotational micromotor relying on the stick-slip effect. This 10 mm X 7 mm X 7 mm motor has the advantage of a relatively high torque at low rotational speed and an excellent runout. While the maximum velocity is 60 rpm, it reaches its highest torque of 0.3 mNm at 2 rpm. Another benefit is the powerless holding torque of 0.9 mNm. With a typical step of 0.1 mrad and a local resolution 3 orders of magnitude better than the step angle, NanoCrab can be very precisely adjusted. Design and measurements of the characteristics of these two mechanisms will be presented and compared with the theoretical analysis of inertial drives presented in a companion paper. Finally their integration into the Nanorobot system will be discussed.

High-precision control of static magnetic field magnitude, orientation, and gradient using optically pumped vapour cell magnetometry.

PubMed

Ingleby, S J; Griffin, P F; Arnold, A S; Chouliara, M; Riis, E

2017-04-01

An integrated system of hardware and software allowing precise definition of arbitrarily oriented magnetic fields up to |B| = 1 μT within a five-layer Mumetal shield is described. The system is calibrated with reference to magnetic resonance observed between Zeeman states of the 6S 1/2 F = 4 133 Cs ground state. Magnetic field definition over the full 4π solid angle is demonstrated with one-sigma tolerances in magnitude, orientation, and gradient of δ|B| = 0.94 nT, δθ = 5.9 mrad, and δ|∇B|=13.0 pT/mm, respectively. This field control is used to empirically map M x magnetometer signal amplitude as a function of the static field (B 0 ) orientation.

Angular resolution of the gaseous micro-pixel detector Gossip

NASA Astrophysics Data System (ADS)

Bilevych, Y.; Blanco Carballo, V.; van Dijk, M.; Fransen, M.; van der Graaf, H.; Hartjes, F.; Hessey, N.; Koppert, W.; Nauta, S.; Rogers, M.; Romaniouk, A.; Veenhof, R.

2011-06-01

Gossip is a gaseous micro-pixel detector with a very thin drift gap intended for a high rate environment like at the pixel layers of ATLAS at the sLHC. The detector outputs not only the crossing point of a traversing MIP, but also the angle of the track, thus greatly simplifying track reconstruction. In this paper we describe a testbeam experiment to examine the angular resolution of the reconstructed track segments in Gossip. We used here the low diffusion gas mixture DME/CO 2 50/50. An angular resolution of 20 mrad for perpendicular tracks could be obtained from a 1.5 mm thin drift volume. However, for the prototype detector used at the testbeam experiment, the resolution of slanting tracks was worsened by poor time resolution of the pixel chip used.

H(-) ion source developments at the SNS.

PubMed

Welton, R F; Stockli, M P; Murray, S N; Pennisi, T R; Han, B; Kang, Y; Goulding, R H; Crisp, D W; Sparks, D O; Luciano, N P; Carmichael, J R; Carr, J

2008-02-01

The U.S. Spallation Neutron Source (SNS) will require substantially higher average and pulse H(-) beam currents than can be produced from conventional ion sources such as the base line SNS source. H(-) currents of 40-50 mA (SNS operations) and 70-100 mA (power upgrade project) with a rms emittance of 0.20-0.35pi mm mrad and a approximately 7% duty factor will be needed. We are therefore investigating several advanced ion source concepts based on rf plasma excitation. First, the performance characteristics of an external antenna source based on an Al(2)O(3) plasma chamber combined with an external multicusp magnetic configuration, an elemental Cs system, and plasma gun will be discussed. Second, the first plasma measurements of a helicon-driven H(-) ion source will also be presented.

Theoretical and experimental aspects of laser cutting with a direct diode laser

NASA Astrophysics Data System (ADS)

Costa Rodrigues, G.; Pencinovsky, J.; Cuypers, M.; Duflou, J. R.

2014-10-01

Recent developments in beam coupling techniques have made it possible to scale up the power of diode lasers with a laser beam quality suitable for laser cutting of metal sheets. In this paper a prototype of a Direct Diode Laser (DDL) source (BPP of 22 mm-mrad) is analyzed in terms of efficiency and cut performance and compared with two established technologies, CO2 and fiber lasers. An analytical model based on absorption calculations is used to predict the performance of the studied laser source with a good agreement with experimental results. Furthermore results of fusion cutting of stainless steel and aluminium alloys as well as oxygen cutting of structural steel are presented, demonstrating that industrial relevant cutting speeds with high cutting quality can now be achieved with DDL.

Attosecond Thomson-scattering x-ray source driven by laser-based electron acceleration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, W.; College of Science, National University of Defense Technology, Changsha 410073; Zhuo, H. B.

2013-10-21

The possibility of producing attosecond x-rays through Thomson scattering of laser light off laser-driven relativistic electron beams is investigated. For a ≤200-as, tens-MeV electron bunch produced with laser ponderomotive-force acceleration in a plasma wire, exceeding 10{sup 6} photons/s in the form of ∼160 as pulses in the range of 3–300 keV are predicted, with a peak brightness of ≥5 × 10{sup 20} photons/(s mm{sup 2} mrad{sup 2} 0.1% bandwidth). Our study suggests that the physical scheme discussed in this work can be used for an ultrafast (attosecond) x-ray source, which is the most beneficial for time-resolved atomic physics, dubbed “attosecondmore » physics.”.« less

[Optimum design of imaging spectrometer based on toroidal uniform-line-spaced (TULS) spectrometer].

PubMed

Xue, Qing-Sheng; Wang, Shu-Rong

2013-05-01

Based on the geometrical aberration theory, a optimum-design method for designing an imaging spectrometer based on toroidal uniform grating spectrometer is proposed. To obtain the best optical parameters, twice optimization is carried out using genetic algorithm(GA) and optical design software ZEMAX A far-ultraviolet(FUV) imaging spectrometer is designed using this method. The working waveband is 110-180 nm, the slit size is 50 microm x 5 mm, and the numerical aperture is 0.1. Using ZEMAX software, the design result is analyzed and evaluated. The results indicate that the MTF for different wavelengths is higher than 0.7 at Nyquist frequency 10 lp x mm(-1), and the RMS spot radius is less than 14 microm. The good imaging quality is achieved over the whole working waveband, the design requirements of spatial resolution 0.5 mrad and spectral resolution 0.6 nm are satisfied. It is certificated that the optimum-design method proposed in this paper is feasible. This method can be applied in other waveband, and is an instruction method for designing grating-dispersion imaging spectrometers.

Laser diode stack beam shaping for efficient and compact long-range laser illuminator design

NASA Astrophysics Data System (ADS)

Lutz, Y.; Poyet, J. M.

2014-04-01

Laser diode stacks are interesting laser sources for active imaging illuminators. They allow the accumulation of large amounts of energy in multi-pulse mode, which is best suited for long-range image recording. Even when the laser diode stacks are equipped with fast-axis collimation (FAC) and slow-axis collimation (SAC) micro-lenses, their beam parameter products BPP are not compatible with direct use in highly efficient and compact illuminators. This is particularly true when narrow divergences are required such as for long-range applications. A solution to overcome these difficulties is to enhance the poor slow-axis BPP by virtually restacking the laser diode stack. We present a beam shaping and homogenization method that is low-cost and efficient and has low alignment sensitivity. After conducting simulations, we have realized and characterized the illuminator. A compact long-range laser illuminator has been set up with a divergence of 3.5×2.6 mrad and a global efficiency of 81%. Here, a projection lens with a clear aperture of 62 mm and a focal length of 571 mm was used.

Influence of irradiation on the osteoinductive potential of demineralized bone matrix.

PubMed

Wientroub, S; Reddi, A H

1988-04-01

Samples of demineralized bone matrix (DBM) were exposed to graduated doses of radiation (1-15 Megarad) (Mrad) utilizing a linear accelerator and then implanted into the thoracic region of Long-Evans rats. Subcutaneous implantation of DBM into allogenic rats induces endochondral bone. In response to matrix implantation, a cascade of events ensues; mesenchymal cell proliferation on day 3 postimplantation, chondrogenesis on day 7, calcification of the cartilagenous matrix and chondrolysis on day 9, and osteogenesis on day 11 resulting in formation of an ossicle containing active hemopoietic tissue. Bone formation was assessed by measuring alkaline phosphatase activity, the rate of mineralization was determined by measuring 45Ca incorporation to bone mineral, and 40Ca content measured the extent of mineralization; acid phosphatase activity was used as a parameter for bone resorption. The dose of radiation (2.5 Mrad) currently used by bone banks for sterilization of bone tissue did not destroy the bone induction properties of DBM. Furthermore, radiation of 3-5 Mrad even enhanced bone induction, insofar as it produced more bone at the same interval of time than was obtained from unirradiated control samples. None of the radiation doses used in these experiments abolished bone induction, although the response induced by matrix irradiated with doses higher than 5 Mrad was delayed.

SEPTUM MAGNET DESIGN FOR THE APS-U

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abliz, M.; Jaski, M.; Xiao, A.

2017-06-25

The Advanced Photon Source is in the process of upgrading its storage ring from a double-bend to a multi-bend lattice as part of the APS Upgrade Project (APS-U). A swap-out injection scheme is planned for the APS-U to keep a constant beam current and to enable a small dynamic aperture. A septum magnet with a minimum thickness of 2 mm and an injection field of 1.06 T has been designed, delivering the required total deflecting angle is 89 mrad with a ring energy of 6 GeV. The stored beam chamber has an 8 mm x 6 mm super-ellipsoidal aperture. Themore » magnet is straight; however, it is tilted in yaw, roll, and pitch from the stored beam chamber to meet the on axis swap out injection requirements for the APS-U lattice. In order to minimize the leakage field inside the stored beam chamber, four different techniques were utilized in the design. As a result, the horizontal deflecting angle of the stored beam was held to only 5 µrad, and the integrated skew quadrupole inside the stored beam chamber was held to 0.09 T. The detailed techniques that were applied to the design, field multipoles, and resulting trajectories of the injected and stored beams are reported.« less

Indirect self-modulation instability measurement concept for the AWAKE proton beam

NASA Astrophysics Data System (ADS)

Turner, M.; Petrenko, A.; Biskup, B.; Burger, S.; Gschwendtner, E.; Lotov, K. V.; Mazzoni, S.; Vincke, H.

2016-09-01

AWAKE, the Advanced Proton-Driven Plasma Wakefield Acceleration Experiment, is a proof-of-principle R&D experiment at CERN using a 400 GeV / c proton beam from the CERN SPS (longitudinal beam size σz = 12 cm) which will be sent into a 10 m long plasma section with a nominal density of ≈ 7 ×1014 atoms /cm3 (plasma wavelength λp = 1.2 mm). In this paper we show that by measuring the time integrated transverse profile of the proton bunch at two locations downstream of the AWAKE plasma, information about the occurrence of the self-modulation instability (SMI) can be inferred. In particular we show that measuring defocused protons with an angle of 1 mrad corresponds to having electric fields in the order of GV/m and fully developed self-modulation of the proton bunch. Additionally, by measuring the defocused beam edge of the self-modulated bunch, information about the growth rate of the instability can be extracted. If hosing instability occurs, it could be detected by measuring a non-uniform defocused beam shape with changing radius. Using a 1 mm thick Chromox scintillation screen for imaging of the self-modulated proton bunch, an edge resolution of 0.6 mm and hence an SMI saturation point resolution of 1.2 m can be achieved.

Ambient beam motion and its excitation by ghost lines in the Tevatron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shiltsev, V.; /Fermilab

2011-03-01

Transverse betatron motion of the Tevatron proton beam is measured and analyzed. It is shown that the motion is coherent and excited by external sources of unknown origins. Observations of the time-varying 'ghost lines' in the betatron spectrum are reported. The direct measurement of the rms betatron oscillations amplitude estimates it at about 110 nm at {beta}{sub y} {approx} 900 m. Correspondingly, at the amplitudes at the average beta function location with {beta}{sub y} {approx} 50 m is about 25 nm. Given that such direct measurements with clearly observable betatron peak were not repeatedly reproducible, one can conclude that wellmore » know 'ghost lines' are the reason for that - as they are come and go without any obvious regularity. Our analysis of these 'ghost lines' shows that (a) besides slow motion across frequencies, they also exhibit oscillatory movements with period varying from 15-20 min to few hours; (b) for the stores analysed, the lines add about factor of 2 to average - over colliding store duration - Schottky power in the betatron bands. The latter allows to estimate that they contribute about half to the previously determined the rms normalized emittance growth rate of some 0.06 {pi} mm mrad/hr. The Tevatron 'ghost lines' look very similar to infamous 'humps' recently observed in the LHC. Those 'humps' are unwanted oscillations seen repeatedly in the LHC beams (mostly in the vertical plane) and also believed to be caused by external excitations.« less

Commissioning and operation of the deuteron injector for PKUNIFTY project

NASA Astrophysics Data System (ADS)

Ren, H. T.; Peng, S. X.; Lu, P. N.; Zhao, J.; Zhou, Q. F.; Song, Z. Z.; Yuan, Z. X.; Yu, J. X.; Guo, Z. Y.; Chen, J. E.

2014-02-01

PKUNIFTY (PeKing University Neutron Imaging FaciliTY), a thermal neutron imaging facility based on a 2 MeV RFQ accelerator, has been constructed at Peking University. Its deuteron injector, which consists of a 2.45 GHz permanent magnet electron cyclotron resonance (PMECR) deuteron ion source and a two-solenoid low energy beam transport (LEBT), aims at producing and delivering 50 mA, 50 keV deuteron beam with a duty factor of 10% (1 ms, 100 Hz). In the preliminary tests of RFQ accelerator, the ECR ion source and LEBT are required to operate at various duty factors (from 1% to 10%). The deuteron ion source has been tested with different pulse widths for this reason. In order to optimize the transmission parameters, the beam current at the exit of RFQ as a function of solenoids tuning and steering magnets tuning are carefully studied. The beam emittance at the entrance of RFQ has been measured with space charge compensation by different argon gas (RG) pressure from 1.6 × 10-4 Pa to 4.7 × 10-3 Pa. The measuring results show the best compensating pressure is 3.5 × 10-3 Pa with a minimal normalized rms emittance of 0.12 pi mm mrad. During the commissioning, we found the purity of deuteron gas is an important factor which severely affects ECR discharge and plasma intensity inside the ion source chamber. The detailed experimental results obtained during the commissioning are discussed in this paper.

Direct current H- source for the medicine accelerator (invited)

NASA Astrophysics Data System (ADS)

Belchenko, Yu.; Savkin, V.

2004-05-01

A compact cw hydrogen negative ion source having reliable operation and a simplified maintenance is developed at Budker Institute of Nuclear Physics for a tandem accelerator of boron capture neutron therapy installation. The source uses a Penning discharge with a hydrogen and cesium feed through the hollows in the cathodes. Discharge voltage is about 60-80 V, current 9 A, hydrogen pressure 4-5 Pa, magnetic field 0.05-0.1 T, and cesium seed <1 mg/h. Negative ions are mainly produced on the cesiated anode surface due to conversion of hydrogen atoms. An optimal anode temperature is 250-350 °C. Negative ion beam current is directly proportional to the discharge current and to the emission hole area. A triode system for the beam extraction and acceleration system is used. The flux of accompanying extracted electrons was decreased by filtering in the transverse magnetic field. This electron flux was intercepted to the special electrode, biased at 4 kV potential with respect to the anode. Source stable cw operation for several hour runs was multiply tested. A H- ion beam with current up to 8 mA, beam energy 23 keV was produced regularly. Negative ion current of heavy impurities had a value of about 3% of the total beam current. Beam normalized emittance is about 0.3 π mm mrad and emission current density -0.1 A/cm2. A built-in cathode heater provides the operation quick start.

Effect of gamma irradiation on the TlBa2Ca2Cu3O9-δ superconducting properties

NASA Astrophysics Data System (ADS)

Kadhim, Bahjat B.; Khaleel, Imad H.; Hussein, Bushra H.; Jasim, Kareem Ail; Shaban, Auday H.; AL-Maiyaly, Bushra K. H.; Mahdi, Shatha H.

2018-05-01

The aim of the present work is studing the influence of gamma irradiation on the superconducting properties of TlBr2Ca2Cu3O9-δ compound, at room temperature by using 137Cs source with dose 10,20 and 30 MRad. Specimen has been prepared by solid state reaction process. Superconductor properties and X-ray diffraction (XRD) studied before and after irradiation. It is showed that our compound has tetragonal structure correspond to the 1223 phase with decreasing of the ratio c/a due to gamma irradiation. In addition, the transition temperature (Tc(on)&Tc(off)) were decreasing from 110 to 85 K, and 129 to 117 K respectivelya,when the dose increasing from 0 to 20 MRad and increase Tc(on) to 119 K &Tc(off) 132 for dose 30 MRad.

A conceptual design study of point focusing thin-film solar concentrators

NASA Technical Reports Server (NTRS)

1981-01-01

Candidates for reflector panel design concepts, including materials and configurations, were identified. The large list of candidates was screened and reduced to the five most promising ones. Cost and technical factors were used in making the final choices for the panel conceptual design, which was a stiffened steel skin substrate with a bonded, acrylic overcoated, aluminized polyester film reflective surface. Computer simulations were run for the concentrator optics using the selected panel design, and experimentally determined specularity and reflectivity values. Intercept factor curves and energy to the aperture curves were produced. These curves indicate that surface errors of 2 mrad (milliradians) or less would be required to capture the desired energy for a Brayton cycle 816 C case. Two test panels were fabricated to demonstrate manufacturability and optically tested for surface error. Surface errors in the range of 1.75 mrad and 2.2 mrad were measured.

Radiation dependence of inverter propagation delay from timing sampler measurements

NASA Technical Reports Server (NTRS)

Buehler, M. G.; Blaes, B. R.; Lin, Y.-S.

1989-01-01

A timing sampler consisting of 14 four-stage inverter-pair chains with different load capacitances was fabricated in 1.6-micron n-well CMOS and irradiated with cobalt-60 at 10 rad(Si)/s. For this CMOS process the measured results indicate that the rising delay increases by about 2.2 ns/Mrad(Si) and the falling delay increase is very small, i.e., less than 300 ps/Mrad(Si). The amount of radiation-induced delay depends on the size of the load capacitance. The maximum value observed for this effect was 5.65 ns/pF-Mrad(Si). Using a sensitivity analysis, the sensitivity of the rising delay to radiation can be explained by a simple timing model and the radiation sensitivity of dc MOSFET parameters. This same approach could not explain the insensitivity of the falling delay to radiation. This may be due to a failure of the timing model and/or trapping effects.

Electron linear accelerator system for natural rubber vulcanization

NASA Astrophysics Data System (ADS)

Rimjaem, S.; Kongmon, E.; Rhodes, M. W.; Saisut, J.; Thongbai, C.

2017-09-01

Development of an electron accelerator system, beam diagnostic instruments, an irradiation apparatus and electron beam processing methodology for natural rubber vulcanization is underway at the Plasma and Beam Physics Research Facility, Chiang Mai University, Thailand. The project is carried out with the aims to improve the qualities of natural rubber products. The system consists of a DC thermionic electron gun, 5-cell standing-wave radio-frequency (RF) linear accelerator (linac) with side-coupling cavities and an electron beam irradiation apparatus. This system is used to produce electron beams with an adjustable energy between 0.5 and 4 MeV and a pulse current of 10-100 mA at a pulse repetition rate of 20-400 Hz. An average absorbed dose between 160 and 640 Gy is expected to be archived for 4 MeV electron beam when the accelerator is operated at 400 Hz. The research activities focus firstly on assembling of the accelerator system, study on accelerator properties and electron beam dynamic simulations. The resonant frequency of the RF linac in π/2 operating mode is 2996.82 MHz for the operating temperature of 35 °C. The beam dynamic simulations were conducted by using the code ASTRA. Simulation results suggest that electron beams with an average energy of 4.002 MeV can be obtained when the linac accelerating gradient is 41.7 MV/m. The rms transverse beam size and normalized rms transverse emittance at the linac exit are 0.91 mm and 10.48 π mm·mrad, respectively. This information can then be used as the input data for Monte Carlo simulations to estimate the electron beam penetration depth and dose distribution in the natural rubber latex. The study results from this research will be used to define optimal conditions for natural rubber vulcanization with different electron beam energies and doses. This is very useful for development of future practical industrial accelerator units.

Radiation resistance of acetal copolymers (in German)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolters, E.; Roesinger, S.

1973-01-01

For the radiation sterilization of equipment and containers made from plastic material, a dose of 2.5 x 10/sup 4/ J/kg (2.5 Mrad) is normally used. Experiments are described which show the influence of the sterilization doses applied in practice on the physical properties of the acetal copolymer Hostaform. Although a certain destruction and simultaneously a reduction in viscous properties are observed as a result of irradiations with gamma rays up to 2.5 x 10/sup 4/ J/kg, the tensile strength remains practically unchanged. Hence gamma -ray sterilization can be applied if there are no special requirements as to the mechanical propertiesmore » of the sterile equipment. (GE)« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vannoni, M., E-mail: maurizio.vannoni@xfel.eu; Freijo Martín, I.

The European XFEL (X-ray Free Electron Laser) is a large facility under construction in Hamburg, Germany. It will provide a transversally fully coherent x-ray radiation with outstanding characteristics: high repetition rate (up to 2700 pulses with a 0.6 ms long pulse train at 10 Hz), short wavelength (down to 0.05 nm), short pulse (in the femtoseconds scale), and high average brilliance (1.6 ⋅ 10{sup 25} (photons s{sup −1} mm{sup −2} mrad{sup −2})/0.1% bandwidth). The beam has very high pulse energy; therefore, it has to be spread out on a relatively long mirror (about 1 m). Due to the very shortmore » wavelength, the mirrors need to have a high quality surface on their entire length, and this is considered very challenging even with the most advanced polishing methods. In order to measure the mirrors and to characterize their interaction with the mechanical mount, we equipped a metrology laboratory with a large aperture Fizeau interferometer. The system is a classical 100 mm diameter commercial Fizeau, with an additional expander providing a 300 mm diameter beam. Despite the commercial nature of the system, special care has been taken in the polishing of the reference flats and in the expander quality. We report the first commissioning of the instrument, its calibration, and performance characterization, together with some preliminary results with the measurement of a 950 mm silicon substrate. The intended application is to characterize the final XFEL mirrors with nanometer accuracy.« less

Design and numerical characterization of a crossover EBIS

NASA Astrophysics Data System (ADS)

Geyer, Sabrina; Langbein, A.; Meusel, Oliver; Kester, Oliver

2015-01-01

For the investigation of highly charged ions, a crossover EBIS (XEBIS) was developed at the University of Frankfurt. In contrast to conventional EBIS/T devices the compression of the electron beam is achieved by electrostatic focusing to a crossover point in the interaction region. This concept allows a compact and simple design. Simulations performed with EGUN show a perveance of 2.1×10-7 A/V3/2 for the realized gun system. In the interaction region the electron beam has a density of around 10 A/cm2 and a minimum radius of 0.15 mm. The XEBIS has a total length of 112 mm with a trap length of 26 mm. It is designed for electron beam energies of up to 6 keV/q. The storage capacity of the trap region is in the order of 1×108 charges. Charge state breeding studies with CBSIM indicate for the noble gases as maximal achievable charge state Ar16+, Kr30+ and Xe35+. Thus ion beam currents of around 2.04 nA assuming 50 Hz repetition rate can be expected. The emittance of the extracted beam is approximated to 8 mm mrad. After completion of the construction phase, the XEBIS will be installed for first performance investigations at a dedicated test bench, equipped with a fast Faraday Cup (FC), a retarding field spectrometer, a luminescence screen and optical diagnostics. Subsequently the XEBIS will serve as source for highly charged ions at different experimental setups.

60Co-irradiation as an alternate method for sterilization of penicillin G, neomycin, novobiocin, and dihydrostreptomycin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsuji, K.; Rahn, P.D.; Steindler, K.A.

The effects of the use of 60Co-irradiation to sterilize antibiotics were evaluated. The antibiotic powders were only occasionally contaminated with microorganisms. The D-values of the products and environmental isolates were 0.028, 0.027, 0.015, 0.046, 0.15, 0.018, and 0.19 Mrads for Aspergillus species (UC 7297, 7298), A. fumigatus (UC 7299), Rhodotorula species (UC 7300), Penicillium oxalicum (UC 7269), Pseudomonas maltophilia (UC 6855), and a biological indicator microorganism, Bacillus pumilus spores (ATCC 27142). An irradiation dose of 1.14 Mrads, therefore, was sufficient to achieve a six-log cycle destruction of B. pumilus spores. Based on the bioburden data, a minimum irradiation dose ofmore » 1.05 Mrads was calculated to be sufficient to obtain a 10(-6) probability of sterilizing the most radioresistant isolate, Pen. oxalicum. To determine the radiolytic degradation scheme and the stability of the antibiotics following irradiation, high-performance liquid chromatographic (HPLC) methods were developed. The resulting rates of degradation for the antibiotics were 0.6, 1.2, 2.3, and 0.95%/Mrad for penicillin G, neomycin, novobiocin, and dihydrostreptomycin, respectively. Furthermore, radiolytic degradation pathways for the antibiotics were identified and found to be similar to those commonly encountered when antibiotics are subjected to acidic, basic, hydrolytic, or oxidative treatments. No radiolytic compounds unique to 60Co-irradiation were found.« less

Increased Risk of Revision After Anterior Cruciate Ligament Reconstruction With Soft Tissue Allografts Compared With Autografts: Graft Processing and Time Make a Difference.

PubMed

Maletis, Gregory B; Chen, Jason; Inacio, Maria C S; Love, Rebecca M; Funahashi, Tadashi T

2017-07-01

The optimal graft for anterior cruciate ligament reconstruction (ACLR) remains controversial. To compare the risk of aseptic revision between bone-patellar tendon-bone (BPTB) autografts, hamstring autografts, and soft tissue allografts. Cohort study; Level of evidence, 2. Prospectively collected ACLR cases reconstructed with BPTB autografts, hamstring autografts, and soft tissue allografts were identified using the Kaiser Permanente ACLR Registry. Aseptic revision was the endpoint. The type of graft and allograft processing method (nonprocessed, <1.8-Mrad irradiation with and without chemical processing [Allowash or AlloTrue], ≥1.8-Mrad irradiation with and without chemical processing, and chemical processing alone [BioCleanse]) were the exposures evaluated. Analyses were adjusted for age, sex, and race. Kaplan-Meier curves and Cox proportional hazards models were employed. The cohort included 14,015 cases: there were 8924 (63.7%) male patients, there were 6397 (45.6%) white patients, 4557 (32.5%) ACLRs used BPTB autografts, 3751 ACLRs (26.8%) used soft tissue allografts, and 5707 (40.7%) ACLRs used hamstring autografts. The median age was 34.6 years for soft tissue allografts, 24.3 years for hamstring autografts, and 22.0 years for BPTB autografts. The crude nonadjusted revision rates were 85 (1.9%) in BPTB autograft cases, 132 (2.3%) in hamstring autograft cases, and 83 (2.2%) in soft tissue allograft cases. After adjusting for age, sex, and race, compared with hamstring autografts, a higher risk of revision was found with allografts with ≥1.8 Mrad without chemical processing after 2.5 years (hazard ratio [HR], 3.88; 95% CI, 1.48-10.12) and ≥1.8 Mrad with chemical processing after 1 year (HR, 3.43; 95% CI, 1.58-7.47) and with BioCleanse processed grafts at any time point (HR, 3.02; 95% CI, 1.40-6.50). Nonprocessed allografts and those irradiated with <1.8 Mrad with or without chemical processing were not found to have a different risk of revision compared with hamstring autografts. Compared with BPTB autografts, a higher risk of revision was seen with hamstring autografts (HR, 1.51; 95% CI, 1.15-1.99) and BioCleanse processed allografts (HR, 4.67; 95% CI, 2.15-10.16). Allografts irradiated with <1.8 Mrad with chemical processing (Allowash or AlloTrue) (HR, 2.19; 95% CI, 1.42-3.38) and without chemical processing (HR, 2.31; 95% CI, 1.40-3.82) had a higher risk of revision, as did allografts with ≥1.8 Mrad without chemical processing after 2 years (HR, 6.30; 95% CI, 3.18-12.48) and ≥1.8 Mrad with chemical processing (Allowash or AlloTrue) after 1 year (HR, 5.03; 95% CI, 2.30-11.00) compared with BPTB autografts. Nonprocessed allografts did not have a higher risk of revision compared with autografts. With the numbers available, direct comparisons between the specific allograft processing methods were not possible. When soft tissue allografts are used for ACLR, processing and time from surgery affect the risk of revision. Tissue processing has a significant effect on the risk of revision surgery, which is most profound with more highly processed grafts and increases with increasing follow-up time. Surgeons and patients need to be aware of the increased risks of revision with the various soft tissue allografts used for ACLR.

Brilliant GeV gamma-ray flash from inverse Compton scattering in the QED regime

NASA Astrophysics Data System (ADS)

Gong, Z.; Hu, R. H.; Lu, H. Y.; Yu, J. Q.; Wang, D. H.; Fu, E. G.; Chen, C. E.; He, X. T.; Yan, X. Q.

2018-04-01

An all-optical scheme is proposed for studying laser plasma based incoherent photon emission from inverse Compton scattering in the quantum electrodynamic regime. A theoretical model is presented to explain the coupling effects among radiation reaction trapping, the self-generated magnetic field and the spiral attractor in phase space, which guarantees the transfer of energy and angular momentum from electromagnetic fields to particles. Taking advantage of a prospective ˜ 1023 W cm-2 laser facility, 3D particle-in-cell simulations show a gamma-ray flash with unprecedented multi-petawatt power and brightness of 1.7 × 1023 photons s-1 mm-2 mrad-2/0.1% bandwidth (at 1 GeV). These results bode well for new research directions in particle physics and laboratory astrophysics exploring laser plasma interactions.

Technical design of RISP RFQ Cooler buncher

NASA Astrophysics Data System (ADS)

Boussaid, Ramzi; Park, Young-Ho; Kondrashev, Sergey

2017-12-01

An RFQCB is designed at Rare Isotope Science Project (RISP) project to efficiently accept high intensity continuous beams provided by ISOL-RISP facility and deliver to Electron Beam Ion Source (EBIS) charge breeder bunched beams with emittance around 3 π.mm.mrad, energy spread < 10 eV and short bunch width ( 10 μs). A new design concept to be implemented in this RFQCB have been developed, including a novel optics system with improved differential pumping system. An electric system providing RF voltages of high amplitudes going up to 10 kV is being also developed. The mechanical design of the various elements forming the radiofrequency quadrupole (RFQ) charge breeder (CB) and their matter are also performed. An overview of the RISP RFQCB design concept as well as the development of its sub-systems will be reported.

Valuation of Normal Range of Ankle Systolic Blood Pressure in Subjects with Normal Arm Systolic Blood Pressure.

PubMed

Gong, Yi; Cao, Kai-wu; Xu, Jin-song; Li, Ju-xiang; Hong, Kui; Cheng, Xiao-shu; Su, Hai

2015-01-01

This study aimed to establish a normal range for ankle systolic blood pressure (SBP). A total of 948 subjects who had normal brachial SBP (90-139 mmHg) at investigation were enrolled. Supine BP of four limbs was simultaneously measured using four automatic BP measurement devices. The ankle-arm difference (An-a) on SBP of both sides was calculated. Two methods were used for establishing normal range of ankle SBP: the 99% method was decided on the 99% reference range of actual ankle BP, and the An-a method was the sum of An-a and the low or up limits of normal arm SBP (90-139 mmHg). Whether in the right or left side, the ankle SBP was significantly higher than the arm SBP (right: 137.1 ± 16.9 vs 119.7 ± 11.4 mmHg, P<0.05). Based on the 99% method, the normal range of ankle SBP was 94~181 mmHg for the total population, 84~166 mmHg for the young (18-44 y), 107~176 mmHg for the middle-aged(45-59 y) and 113~179 mmHg for the elderly (≥ 60 y) group. As the An-a on SBP was 13 mmHg in the young group and 20 mmHg in both middle-aged and elderly groups, the normal range of ankle SBP on the An-a method was 103-153 mmHg for young and 110-160 mmHg for middle-elderly subjects. A primary reference for normal ankle SBP was suggested as 100-165 mmHg in the young and 110-170 mmHg in the middle-elderly subjects.

Free Electron Laser Analysis For the Innovative Navy Prototype

DTIC Science & Technology

2008-03-01

important measure of electron beam quality is transverse emittance, which is the product of the RMS width and the angular spread of the beam, as measured...respect to s . This is possible because the electron’s position in s is uniquely defined for any given time by s = vst ≈ ct , therefore d 2 dt 2...Longitudinal emittance (keV ps) 70 dgog Beam energy spread (%) 0.37 dthetax Beam angular spread, x rms (mrad) 0.17 dthetay Beam angular spread, y rms (mrad

Design of a Paraxial Inverse Compton Scattering Diagnostic for an Intense Relativistic Electron Beam

DTIC Science & Technology

2013-06-01

with a 50 cm focal length plano-convex lens (Fig. 4). Prior to entering the vacuum the laser light passes through a Brewster angled window, which...1/γ ~ 25 mrad. Brewster angled windows Beam dump Spectra Physics 5J Nd:YAG Focusing lens Insertable power meter z x y 37.8 cm Figure 4...visible green light is upscattered into the soft X-ray range and diverges from the interception point downstream at an angle θs = 1/γ ~ 25 mrad

Segmented-field radiography in scoliosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daniel, W.W.; Barnes, G.T.; Nasca, R.J.

1985-02-01

A method of scoliosis imaging using segmented fields is presented. The method is advantageous for patients requiring serial radiographic monitoring, as it results in markedly reduced radiation doses to critical organs, particularly the breast. Absorbed dose to the breast was measured to be 8.8 mrad (88 ..mu..Gy) for a full-field examination and 0.051 mrad (5.1 ..mu..Gy) for the segmented-field study. The segmented-field technique also results in improved image quality. Experience with 53 studies in 23 patients is reported.

IRRADIATION OF EGGS AND EGG PRODUCTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brooks, J.; Hannan, R.S.; Hobbs, B.C.

It has been known for some time that egg products may contain members of the Salmonella group capable of causing food poisoning, and the position has been rendered more serious by the recent discovery of S. paratyphi B in some of the samples of egg products. Attempts to destroy salmonellae in liquid egg by pasteurization before freezing or drying have met with considerable success but the process requires careful control. The tins in which the frozen product is distributed hold up to 20 kg, and are therefore of a size suitable for treatment with gamma -radiation. After treatment of smallmore » samples of frozen whole egg with 2 Mev cathode rays it was concluded that a dose of about O.3 to 0.5 Mrad would destroy the numbers of salmonellae normally encountered in the product without impairing the baking qualities of the material. Whole tins, each containing 10 kg of infected material, were therefore irradiated in the frozen state with Co/sup 60/ gamma -rays. Two tins were treated at each of three dose levels of 0.3, 0.4, and 0.5 Mrad. No salmonellae were detected in duplicate samples of 25 g of material taken from each of the tins after irradiation. If the effectiveness of the treatment is confirmed, the process has obvious attractions since it dispenses with the need to thaw or otherwise to handle the product. The paper also contains a general discussion on the irradiation of eggs and egg products. (auth)« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, P.H.; Krishnamurthy, G.T.; Bobba, V.R.

The radiation absorbed doses from five commercially available hepatobiliary agents-Tc-99m-tagged analogs of IDA (EIDA, PIPIDA, HIDA, PBIDA, DISIDA*) have been calculated from biokinetic data in 41 normal subjects. Serial gamma images, with blood and urine samples, were obtained to calculate cumulated radioactivity in the source organs: blood, kidey, bladder, liver, gallbladder, and intestines. The critical organ was the gallbladder, with an absorbed-dose range of 690 to 780 mrad/mCi. Absorbed doses for other target organs were: upper large intestine 320 to 370 mrad/mCi, lower large intestine 210 to 240, small intestine 170 to 200, liver 65 (DISIDA) to 130 (PBIDA), ovariesmore » 63 to 72, and urinary bladder wall 23 (PBIDA) to 36 (EIDA). The radiation absorbed dose was largely independent of changes in chemical structure except in (a) the liver, where absorbed dose varied by a factor of two in proportion to the rate of excretion of the IDA agent from the liver, and (b) the urinary bladder, where absorbed dose varied by a factor of 1.6 because of differences in rate of excretion. When the stimulus for gallbladder emptying is changed from whole-meal ingestion to cholecystokinin injection, the absorbed dose to the gallbladder increases to approx. 1 rad/mCi; if no gallbladder emptying is assumed, its absorbed dose increases to approx. 1.9 rad/mCi. In the absence of contraindication, the gallbladder absorbed dose may thus be decreased by inducing gallbladder emptying at the end of the imaging study.« less

Effect of High Energy Radiation on Mechanical Properties of Graphite Fiber Reinforced Composites. M.S. Thesis

NASA Technical Reports Server (NTRS)

Naranong, N.

1980-01-01

The flexural strength and average modulus of graphite fiber reinforced composites were tested before and after exposure to 0.5 Mev electron radiation and 1.33 Mev gamma radiation by using a three point bending test (ASTM D-790). The irradiation was conducted on vacuum treated samples. Graphite fiber/epoxy (T300/5208), graphite fiber/polyimide (C6000/PMR 15) and graphite fiber/polysulfone (C6000/P1700) composites after being irradiated with 0.5 Mev electron radiation in vacuum up to 5000 Mrad, show increases in stress and modulus of approximately 12% compared with the controls. Graphite fiber/epoxy (T300/5208 and AS/3501-6), after being irradiated with 1.33 Mev gamma radiation up to 360 Mrads, show increases in stress and modulus of approximately 6% at 167 Mrad compared with the controls. Results suggest that the graphite fiber composites studied should withstand the high energy radiation in a space environment for a considerable time, e.g., over 30 years.

Hybrid diffractive-refractive optical system design of head-mounted display for augmented reality

NASA Astrophysics Data System (ADS)

Zhang, Huijuan

2005-02-01

An optical see-through head-mounted display for augmented reality is designed in this paper. Considering the factors, such as the optical performance, the utilization ratios of energy of real world and virtual world, the feelings of users when he wears it and etc., a structure of the optical see-through is adopted. With the characteristics of the particular negative dispersive and the power of realizing random-phase modulation, the diffractive surface is helpful for optical system of reducing weight, simplifying structure and etc., and a diffractive surface is introduced in our optical system. The optical system with 25 mm eye relief, 12 mm exit pupil and 20° (H)x15.4° (V) field-of-view is designed. The utilization ratios of energy of real world and virtual world are 1/4 and 1/2, respectively. The angular resolution of display is 0.27 mrad and it less than that of the minimum of human eyes. The diameter of this system is less than 46mm, and it applies the binocular. This diffractive-refractive optical system of see-through head-mounted display not only satisfies the demands of user"s factors in structure, but also with high resolution, very small chromatic aberration and distortion, and satisfies the need of augmented reality. In the end, the parameters of the diffractive surface are discussed.

Performance of a novel SQUID-based superconducting imaging-surface magnetoencephalography system

NASA Astrophysics Data System (ADS)

Kraus, R. H.; Volegov, P.; Maharajh, K.; Espy, M. A.; Matlashov, A. N.; Flynn, E. R.

2002-03-01

Performance for a recently completed whole-head magnetoencephalography system using a superconducting imaging surface (SIS) surrounding an array of 150 SQUID magnetometers is reported. The helmet-like SIS is hemispherical in shape with a brim. Conceptually, the SIS images nearby sources onto the SQUIDs while shielding sensors from distant “noise” sources. A finite element method (FEM) description using the as-built geometry was developed to describe the SIS effect on source fields by imposing B⊥( surface)=0 . Sensors consist of 8×8 mm 2 SQUID magnetometers with 0.84 nT/ Φ0 sensitivity and <3 fT/ Hz noise. A series of phantom experiments to verify system efficacy have been completed. Simple dry-wire phantoms were used to eliminate model dependence from our results. Phantom coils were distributed throughout the volume encompassed by the array with a variety of orientations. Each phantom coil was precisely machined and located to better than 25 μm and 10 mRad accuracy. Excellent agreement between model-calculated and measured magnetic field distributions of all phantom coil positions and orientations was found. Good agreement was found between modeled and measured shielding of the SQUIDs from sources external to the array showing significant frequency-independent shielding. Phantom localization precision was better than 0.5 mm at all locations with a mean of better than 0.3 mm.

Laboratory Investigation of Complex Conductivity and Magnetic Susceptibility on Natural Iron Oxide Coated Sand

NASA Astrophysics Data System (ADS)

Wang, C.; Slater, L. D.; Day-Lewis, F. D.; Briggs, M. A.

2017-12-01

Redox reactions occurring at the oxic/anoxic interface where groundwater discharges to surface water commonly result in iron oxide deposition that coats sediment grains. With relatively large total surface area, these iron oxide coated sediments serve as a sink for sorption of dissolved contaminants, although this sink may be temporary if redox conditions fluctuate with varied flow conditions. Characterization of the distribution of iron oxides in streambed sediments could provide valuable understanding of biogeochemical reactions and the ability of a natural system to sorb contaminants. Towards developing a field methodology, we conducted laboratory spectral induced polarization (SIP) and magnetic susceptibility (MS) measurements on natural iron oxide coated sand (Fe-sand) with grain sizes ranging from 0.3 to 2.0 mm in order to assess the sensitivity of these measurements to iron oxides in sediments. The Fe-sand was also sorted by sieving into various grain sizes to study the impact of grain size on the polarization mechanisms. The unsorted Fe-sand saturated with 0.01 S/m NaCl solution exhibited a distinct phase response ( > 4 mrad) in the frequency range from 0.001 to 100 Hz whereas regular silica sand was characterized by a phase response less than 1 mrad under the same conditions. The presence of iron oxide substantially increased MS (3.08×10-3 SI) over that of regular sand ( < 10-5 SI). An increase of both phase peak and relaxation time was found with increasing grain size of the sorted Fe-sand. Laboratory results demonstrated that SIP and MS may be well suited to mapping the distribution of iron oxides in streambed sediments associated with anoxic groundwater discharge.

Use of irradiation for the treatment of various animal feed products

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ley, F.J.

1972-11-01

Results are summarized from investigations on the use of ionizing radiations for the sterilization of pathogenic microorganisms in animal feeds. Data are reported from stadies on the lethal radiation dose for various strains of Salmonella, Bacillus anthracis, and various strains of Enterobacteriaceae, the effects of doses of 0.8 Mrad to 5 Mrad radiation on the wholesomeness of various protein concentrates used in animal feeds; the radiopreservation of meats used in animal diets; and the cost of radiation processing for extension of the storage life of animal feeds. (16 references). (C.H.)

Effect of 1.33 Mev gamma radiation and 0.5 Mev electrons on the mechanical properties of graphite fiber composites

NASA Technical Reports Server (NTRS)

Fornes, R. E.; Memory, J. D.; Naranong, N.

1982-01-01

Epoxy/graphite fiber, polyimide/graphite fiber, and polysulfone/graphite fiber composites were exposed to 1.33 Mev gamma irradiation and 0.5 Mev electron bombardment for varying periods of time. The effects of the irradiation treatments on the breaking stress and Young's modulus were studied by a three point bending test. Effects were small; both electron radiation up to 5000 Mrad and gamma radiation up to 350 Mrad resulted in slight increases in both stress and modulus.

Recent testing of a micro autonomous positioning system for multi-object instrumentation

NASA Astrophysics Data System (ADS)

Cochrane, W. A.; Atkinson, D. C.; Bailie, T. E. C.; Dickson, C.; Lim, T.; Luo, X.; Montgomery, D. M.; Schnetler, H.; Taylor, W. D.; Wilson, B.

2012-09-01

A multiple pick off mirror positioning sub-system has been developed as a solution for the deployment of mirrors within multi-object instrumentation such as the EAGLE instrument in the European Extremely Large Telescope (E-ELT). The positioning sub-system is a two wheeled differential steered friction drive robot with a footprint of approximately 20 x 20 mm. Controlled by RF communications there are two versions of the robot that exist. One is powered by a single cell lithium ion battery and the other utilises a power floor system. The robots use two brushless DC motors with 125:1 planetary gear heads for positioning in the coarse drive stages. A unique power floor allows the robots to be positioned at any location in any orientation on the focal plane. The design, linear repeatability tests, metrology and power continuity of the robot will be evaluated and presented in this paper. To gather photons from the objects of interest it is important to position POMs within a sphere of confusion of less than 10 μm, with an angular alignment better than 1 mrad. The robots potential of meeting these requirements will be described through the open-loop repeatability tests conducted with a Faro laser beam tracker. Tests have involved sending the robot step commands and automatically taking continuous measurements every three seconds. Currently the robot is capable of repeatedly travelling 233 mm within 0.307 mm at 5 mm/s. An analysis of the power floors reliability through the continuous monitoring of the voltage across the tracks with a Pico logger will also be presented.

Cryogenic system for BERLinPro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anders, W.; Hellwig, A.; Knobloch, J.

2014-01-29

In 2010 Helmholtz-Zentrum Berlin (HZB) received funding to design and build the Berlin Energy Recovery Linac Project BERLinPro. The goal of this compact Energy recovery linac (ERL) is to develop the accelerator physics and technology required to generate and accelerate a 100-mA, 1-mm mrad emittance electron beam. The BERLinPro know-how can then be transferred to various ERL-based applications. All accelerating RF cavities including the electron source are based on superconducting technology operated at 1.8 K. A Linde L700 helium liquefier is supplying 4.5 K helium. The subatmospheric pressure of 16 mbar of the helium bath of the cavities will bemore » achieved by pumping with a set of cold compressors and warm vacuum pumps. While the L700 is already in operating, the 1.8 K system and the helium transfer system are in design phase.« less

Positron production by x rays emitted by betatron motion in a plasma wiggler.

PubMed

Johnson, D K; Auerbach, D; Blumenfeld, I; Barnes, C D; Clayton, C E; Decker, F J; Deng, S; Emma, P; Hogan, M J; Huang, C; Ischebeck, R; Iverson, R; Joshi, C; Katsouleas, T C; Kirby, N; Krejcik, P; Lu, W; Marsh, K A; Mori, W B; Muggli, P; O'Connell, C L; Oz, E; Siemann, R H; Walz, D; Zhou, M

2006-10-27

Positrons in the energy range of 3-30 MeV, produced by x rays emitted by betatron motion in a plasma wiggler of 28.5 GeV electrons from the SLAC accelerator, have been measured. The extremely high-strength plasma wiggler is an ion column induced by the electron beam as it propagates through and ionizes dense lithium vapor. X rays in the range of 1-50 MeV in a forward cone angle of 0.1 mrad collide with a 1.7 mm thick tungsten target to produce electron-positron pairs. The positron spectra are found to be strongly influenced by the plasma density and length as well as the electron bunch length. By characterizing the beam propagation in the ion column these influences are quantified and result in excellent agreement between the measured and calculated positron spectra.

INJECTION SYSTEM DESIGN FOR THE BSNS/RCS.

DOE Office of Scientific and Technical Information (OSTI.GOV)

WEI, J.; TANG, J.Y.; CHEN, Y.

2006-06-23

The BSNS injection system is designed to take one uninterrupted long drift in one of the four dispersion-free straight sections to host all the injection devices. Painting bumper magnets are used for both horizontal and vertical phase space painting. Closed-orbit bumper magnets are used for facilitating the installation of the injection septa and decreasing proton traversal in the stripping foil. Even with large beam emittance of about 300 {pi}mm.mrad used, BSNS/RCS still approaches the space charge limit during the injection/trapping phase for the accumulated particles of 1.9*10{sup 13} and at the low injection energy of 80 MeV. Uniform-like beam distributionmore » by well-designed painting scheme is then obtained to decrease the tune shift/spread. ORBIT code is used for the 3D simulations. Upgrading to higher injection energy has also been considered.« less

Direct diode lasers with comparable beam quality to fiber, CO2, and solid state lasers

NASA Astrophysics Data System (ADS)

Huang, Robin K.; Chann, Bien; Burgess, James; Kaiman, Michael; Overman, Robert; Glenn, John D.; Tayebati, Parviz

2012-03-01

TeraDiode has produced kW-class ultra-high brightness fiber-coupled direct diode lasers. A fiber-coupled direct diode laser with a power level of 2,040 W from a 50 μm core diameter, 0.15 numerical aperture (NA) output fiber at a single center wavelength was demonstrated. This was achieved with a novel beam combining and shaping technique using COTS diode lasers. The fiber-coupled output corresponds to a Beam Parameter Product (BPP) of 3.75 mm-mrad and is the lowest BPP kW-class direct diode laser yet reported. This laser is suitable for industrial materials processing applications, including sheet metal cutting and welding. This 2-kW fiber-coupled direct diode laser has comparable brightness to that of industrial fiber lasers and CO2 lasers, and is over 10x brighter than state-of-the-art direct diode lasers.

Multiaperture ion beam extraction from gas-dynamic electron cyclotron resonance source of multicharged ions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sidorov, A.; Dorf, M.; Zorin, V.

2008-02-15

Electron cyclotron resonance ion source with quasi-gas-dynamic regime of plasma confinement (ReGIS), constructed at the Institute of Applied Physics, Russia, provides opportunities for extracting intense and high-brightness multicharged ion beams. Despite the short plasma lifetime in a magnetic trap of a ReGIS, the degree of multiple ionization may be significantly enhanced by the increase in power and frequency of the applied microwave radiation. The present work is focused on studying the intense beam quality of this source by the pepper-pot method. A single beamlet emittance measured by the pepper-pot method was found to be {approx}70 {pi} mm mrad, and themore » total extracted beam current obtained at 14 kV extraction voltage was {approx}25 mA. The results of the numerical simulations of ion beam extraction are found to be in good agreement with experimental data.« less

GAMMA IRRADIATION OF SALMONELLA SPECIES IN FROZEN WHOLE EGG

DOE Office of Scientific and Technical Information (OSTI.GOV)

Comer, A.G.; Anderson, G.W.; Garrard, E.H.

1963-06-01

A study was undertaken to establish the survival pattern of 18 Salmonella species in frozen whole egg exposed to gamma radiation from a Co/sup 60/ source as part of a program to investigate the possibilities of using radiation for the destruction of micro-organisms in foods. A definite variation in sensitivity to radiation was found among these 18 species commonly occurring in frozen egg. The dose levels, applied at a dose rate of 0.491 Mrad/hr, required for a 10/sup 7/-fold reduction of these species ranged from 0.36 to 0.54 Mrad. Variation in sensitivity to radiation was also detected with three culturesmore » of S. pullorum that appeared similar except in origin. Variation in sensitivity within all species of Salmonella studied apparently indicates that no one species can be considered most resistant. These studies reveal that a level of 0.54 Mrad of gamma radiation would reduce the salmonellae to a safe level in frozen egg. However, this is based on the supposition that 10/sup 5/ cells is a reasonable number to consider necessary for the initiation of salmonellosis. The most heavily contaminated frozen egg melange examined contained approximates 2 x 10/sup 5/ cells of salmonellae/ml. Of these, any process giving a 10/sup 7/-fold reduction would leave only 2 x 10/sup -2/ cells/ml, i.e., 2 cells/100 ml or about 10 cells per lb. Apparently it would be necessary to consume several tons of uncooked melange to obtain an infective dose and therefore the 10/sup 7/-fold reduction is adequate from the viewpoint of the public health hazard. Although off-flavors develop in frozen whole egg irradiated with 0.5 Mrad, they disappear on storage and the irradiated product was found acceptable for commercial use. Thus irradiation of frozen whole egg melange with 0.54 Mrad would not be expected to markedly increase the unfavorable alterations in the product, indicating that gamma radiation possesses a distinct potential for removing Salmonella from frozen whole egg melange. (BBB)« less

Domain mapping of the Rad51 paralog protein complexes

PubMed Central

Miller, Kristi A.; Sawicka, Dorota; Barsky, Daniel; Albala, Joanna S.

2004-01-01

The five human Rad51 paralogs are suggested to play an important role in the maintenance of genome stability through their function in DNA double-strand break repair. These proteins have been found to form two distinct complexes in vivo, Rad51B–Rad51C–Rad51D–Xrcc2 (BCDX2) and Rad51C–Xrcc3 (CX3). Based on the recent Pyrococcus furiosus Rad51 structure, we have used homology modeling to design deletion mutants of the Rad51 paralogs. The models of the human Rad51B, Rad51C, Xrcc3 and murine Rad51D (mRad51D) proteins reveal distinct N-terminal and C-terminal domains connected by a linker region. Using yeast two-hybrid and co-immunoprecipitation techniques, we have demonstrated that a fragment of Rad51B containing amino acid residues 1–75 interacts with the C-terminus and linker of Rad51C, residues 79–376, and this region of Rad51C also interacts with mRad51D and Xrcc3. We have also determined that the N-terminal domain of mRad51D, residues 4–77, binds to Xrcc2 while the C-terminal domain of mRad51D, residues 77–328, binds Rad51C. By this, we have identified the binding domains of the BCDX2 and CX3 complexes to further characterize the interaction of these proteins and propose a scheme for the three-dimensional architecture of the BCDX2 and CX3 paralog complexes. PMID:14704354

Scintigraphic diagnosis of gastric carcinoma (in Hebrew)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Czerniak, D.

1972-09-01

During the past 10 years efforts have been made to develop a radioisotope test for gastric malignancy. Phosphorus-32 was used by intracavity procedures (gastric tube-detector; autoradiography) but the procedures were difficult. In 1961 the first scintillographic assays with scanners and then with scintillation cameras were performed. Iodine-131 was used at first and since 1965 /sup 99m/Tc, which is superior from a physical point of view. It was established that a cold space-occupying lesion in the gastroscan indicates malignancy and that a foggy scan, general or local, may also indicate a neoplastic lesion. All other conditions, including peptic ulcer and gastritis,more » give a normal scan. In the dog, injection of /sup 99m/Tc indicated a turnover of the isotope in the body, and that it is concentrated in the gastric mucosa and excreted in the gastric juice. A gastroscintillographic study in 220 patients showed that 54 of them had stomach malignancies (51 carcinoma and 3 sarcoma). Only neoplasms at least 2 cm in diameter were visualized. In all the patients, clinical, radiological, and biochemical examinations were performed and in most, pathological examinations as well. There was correspondence with the final diagnosis in 80% of the scintillographed cancers and in 92% of those studied roentgenologically. The false scinttllographic diagnosed conclusions were mostly in diffurent patients than in those with false roentgenological diagnoses. It can therefore be concluded that the two methods are complementary. The radiological exposure due to /sup 99m/Tc scintivisualization is low, 200 mrad to the stomach and l5 mrad to the whole body. (INIS)« less

AD620SQ/883B Total Ionizing Dose Radiation Lot Acceptance Report for RESTORE-LEO

NASA Technical Reports Server (NTRS)

Burton, Noah; Campola, Michael

2017-01-01

A Radiation Lot Acceptance Test was performed on the AD620SQ/883B, Lot 1708D, in accordance with MIL-STD-883, Method 1019, Condition D. Using a Co-60 source 4 biased parts and 4 unbiased parts were irradiated at 10 mrad/s (0.036 krad/hr) in intervals of approximately 1 krad from 3-10 krads, and ones of 5 krads from 10-25 krads, where it was annealed while unbiased at 25 degrees Celsius, for 2 days, and then, subsequently, annealed while biased at 25 degrees celsius, for another 7 days.

Seven-core neodymium-doped phosphate all-solid photonic crystal fibers

NASA Astrophysics Data System (ADS)

Wang, Longfei; He, Dongbing; Feng, Suya; Yu, Chunlei; Hu, Lili; Chen, Danping

2016-01-01

We demonstrate a single-mode seven-core Nd-doped phosphate photonic crystal fiber with all-solid structure with an effective mode field diameter of 108 μm. The multicore fiber is first theoretically investigated through the finite-difference time-domain method. Then the in-phase mode is selected experimentally by a far-field mode-filtering method. The obtained in-phase mode has 7 mrad mode field divergences, which approximately agrees with the predicted 5.6 mrad in seven-core fiber. Output power of 15.5 W was extracted from a 25 cm fiber with slope efficiency of 57%.

The effects of hot carrier and swift heavy ion irradiation on electrical characteristics of advanced 200 GHz SiGe HBTs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vinayakprasanna, N. H.; Praveen, K. C.; Prakash, A. P. Gnana, E-mail: gnanaprakash@physics.uni-mysore.ac.in

The 200 GHz SiGe HBTs were irradiated with 80 MeV Carbon ions up to a total dose of 100 Mrad to understand the degradation in electrical characteristics. The degradation in the electrical characteristics of SiGe HBTs was also studied by mixed mode electrical stress up to 10,000 s. The electrical characteristics were measured before and after every total dose and after fixed stress time. The normalized peak h{sub FE} of the stressed and irradiated SiGe HBTs are compared to estimate the equivalent stress time for a particular total dose. These correlations are drawn for the first time and the resultsmore » will establish a systematic relation between stress time and total dose.« less

Different milk feeding intensities during the first 4 weeks of rearing in dairy calves: Part 1: Effects on performance and production from birth over the first lactation.

PubMed

Korst, M; Koch, C; Kesser, J; Müller, U; Romberg, F-J; Rehage, J; Eder, K; Sauerwein, H

2017-04-01

We aimed to test the effects of ad libitum feeding of whole milk (WM) or milk replacer (MR) versus restrictive feeding of MR during the first 4 wk of life on growth performance and on milk yield in the first lactation. We studied 57 German Holstein calves (29 females, 28 males) from birth until d 110 of life (trial 1). The 28 females from trial 1 were further studied during their first lactation (trial 2). In trial 1, all calves were randomly allocated at birth to 1 of 3 groups: MR-res [n = 20, 6.78 kg MR (11.5% solids)/calf per day], MR-ad lib (n = 17, 13.8% solids) or WM-ad lib (n = 20). All calves received colostrum ad libitum from their dam until d 3 of age. From d 4 to 27, calves were fed according to their group regimen. From d 28 to 55, all calves received MR-res feeding and were then gradually weaned until d 69. We recorded body weight (until d 110) and feed intake (amount, metabolizable energy, and frequency of liquid feed intake until weaning). We estimated the profitability of the different feeding regimens, taking into account income from milk yield (trial 2) and feed costs during rearing. In trial 1, the calves from WM-ad lib and MR-ad lib had total metabolizable energy intakes 2.02- and 1.65-fold greater than the MR-res group during the first 4 wk of life. During this period, concentrate intake did not differ among groups, but tended to be greater in WM-ad lib than in MR-ad lib calves from d 28 to 69. The MR-res calves visited the automatic feeders more often than the ad libitum-fed groups during differential feeding, but 70% of the visits were unrewarded (<10% in the ad libitum-fed calves). When all calves were fed at the MR-res level, the average proportion of unrewarded visits was 65% in all groups. Average daily gain and body weight were greater among MR-ad lib and WM-ad lib calves than among MR-res animals during the first 4 wk of life, but not from d 1 to 110. In trial 2, age at first calving, dry matter intake, and body weight over the first 10 mo of lactation were not different among groups, nor was milk composition. Milk yields (305 d) were numerically but not statistically greater in the ad libitum-fed groups during the first lactation (+765 kg for WM-ad lib vs. MR-res; +612 kg for MR-ad lib vs. MR-res). Feeding WM-ad lib and MR-ad lib was 1.37- and 1.21-fold more costly than MR-res, respectively, but amounted to 18, 15, and 13% of the total estimated feed costs until first calving in WM-ad lib, MR-ad lib, and MR-res, respectively. Our study confirms that ad libitum feeding is an attractive measure for rearing dairy calves, both for animal welfare and-with the caveat of a small sample size in trial 2 that led to insufficient power-economic profit from milk. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Biomechanical measurements of stopping and stripping torques during screw insertion in five types of human and artificial humeri.

PubMed

Aziz, Mina Sr; Tsuji, Matthew Rs; Nicayenzi, Bruce; Crookshank, Meghan C; Bougherara, Habiba; Schemitsch, Emil H; Zdero, Radovan

2014-05-01

During orthopedic surgery, screws are inserted by "subjective feel" in humeri for fracture fixation, that is, stopping torque, while trying to prevent accidental over-tightening that causes screw-bone interface failure, that is, stripping torque. However, no studies exist on stopping torque, stripping torque, or stopping/stripping torque ratio in human or artificial humeri. This study evaluated five types of humeri, namely, human fresh-frozen (n = 19), human embalmed (n = 18), human dried (n = 15), artificial "normal" (n = 13), and artificial "osteoporotic" (n = 13). An orthopedic surgeon used a torque screwdriver to insert 3.5-mm-diameter cortical screws into humeral shafts and 6.5-mm-diameter cancellous screws into humeral heads by "subjective feel" to obtain stopping and stripping torques. The five outcome measures were raw and normalized stopping torque, raw and normalized stripping torque, and stopping/stripping torque ratio. Normalization was done as raw torque/screw-bone interface area. For "gold standard" fresh-frozen humeri, cortical screw tests yielded averages of 1312 N mm (raw stopping torque), 30.4 N/mm (normalized stopping torque), 1721 N mm (raw stripping torque), 39.0 N/mm (normalized stripping torque), and 82% (stopping/stripping torque ratio). Similarly, fresh-frozen humeri gave cancellous screw average results of 307 N mm (raw stopping torque), 0.9 N/mm (normalized stopping torque), 392 N mm (raw stripping torque), 1.2 N/mm (normalized stripping torque), and 79% (stopping/stripping torque ratio). Of the five cortical screw parameters for fresh-frozen humeri versus other groups, statistical equivalence (p ≥ 0.05) occurred in four cases (embalmed), three cases (dried), four cases (artificial "normal"), and four cases (artificial "osteoporotic"). Of the five cancellous screw parameters for fresh-frozen humeri versus other groups, statistical equivalence (p ≥ 0.05) occurred in five cases (embalmed), one case (dried), one case (artificial "normal"), and zero cases (artificial "osteoporotic"). Stopping/stripping torque ratios were relatively constant for all groups at 77%-88% (cortical screws) and 79%-92% (cancellous screws). © IMechE 2014.

60Co irradiation for sterilization of veterinary mastitis products containing antibiotics and steroids

NASA Astrophysics Data System (ADS)

Tsuji, K.; Kane, M. P.; Rahn, P. D.; Steindler, K. A.

Effects of 60Co irradiation for sterilization of veterinary mastitis products were evaluated. The mastitis products which were examined contained various combinations of antibiotics and steroids suspended in peanut oil vehicle. Bioburden data indicated that the unirradiated products were only occasionally contaminated with microorganisms. The D-values of the nonsterile product and environmental isolates were 0.028, 0.15, 0.017, and 0.018 Mrads for Aspergillus fumigatus, Penicillium oxalicum, Pseudomonas aeruginosa, and Pseudomonas maltophilia, respectively. The D-value of the biological indicator organism, Bacillus pumilus spores, in the vehicle was 0.27 Mrads. Thus, an irradiation dose of 1.6 Mrads would be sufficient to achieve six log cycles of destruction of the biological indicator organism. The minimum absorbed irradiation dose of 2.5 Mrads preferred by many countries for sterilization would achieve 9.3 log cycle destruction of the indicator organism and guarantee a probability of 1 × 10 -15 assurance for the most radio-resistant product isolate, Penicillium oxalicum. In order to examine short and long term chemical stabilities of active components, stability indicating high-performance liquid chromatographic (HPLC) methods for the determination of the following antibiotics and steroids were developed. They were: dihydrostreptomycin, neomycin, novobiocin, penicillin G, hydrocortisone acetate, hydrocortisone sodium succinate, and prednisolone. The rates of degradation and radiolytic degradation schemes for the majority of these compounds were elucidated. Formation of new compounds was not observed in these antibiotics and steroids upon 60Co irradiation. The compounds that increased by irradiation were inherently present in commercially available non-irradiated lots and/or can easily be formed by either acidic, basic, or thermal treatment.

Optimization of woven jute/glass fibre-reinforced polyester hybrid composite solar parabolic trough collector

NASA Astrophysics Data System (ADS)

Reddy, K. S.; Singla, Hitesh

2017-07-01

In the present work, structural analysis of 5.77m × 4m woven jute (J)/glass (G) fibre-reinforced polyester hybrid composite solar parabolic trough is carried out based on trough parameters to obtain the minimum RMS local slope deviation, termed as SDx value under gravity loading. The optimization is done by varying parameters viz. direction and size of reinforced conduits, stacking number and sequence of hybrid trough laminate at fibre orientation of Δθ=45° and Δθ=60° amongst the layers at 0° collector angle. The analysis revealed that the configuration in which the conduits are placed in both X and Y directions is preferred over other configurations to scale down the effect of wind loads. Furthermore it has been observed that laminate of the order [0°G/45°G/-45°J/90°J]s undergoes minimum surface deformation amongst all the other configurations at conduit reinforcement in both X and Y directions for a conduit thickness of 0.75 mm and radius of 10 mm and obtains the overall SDx value of 1.3492 mrad. The results shows that proposed trough model is very promising and evolves a cost effective system.

Non-invasive three-dimension control of light between turbid layers using a surface quasi-point light source for precorrection.

PubMed

Qiao, Mu; Liu, Honglin; Pang, Guanghui; Han, Shensheng

2017-08-29

Manipulating light non-invasively through inhomogeneous media is an attractive goal in many disciplines. Wavefront shaping and optical phase conjugation can focus light to a point. Transmission matrix method can control light on multiple output modes simultaneously. Here we report a non-invasive approach which enables three-dimension (3D) light control between two turbid layers. A digital optical phase conjugation mirror measured and conjugated the diffused wavefront, which originated from a quasi-point source on the front turbid layer and passed through the back turbid layer. And then, because of memory effect, the phase-conjugated wavefront could be used as a carrier wave to transport a pre-calculated wavefront through the back turbid layer. The pre-calculated wavefront could project a desired 3D light field inside the sample, which, in our experiments, consisted of two 220-grid ground glass plates spaced by a 20 mm distance. The controllable range of light, according to the memory effect, was calculated to be 80 mrad in solid angle and 16 mm on z-axis. Due to the 3D light control ability, our approach may find applications in photodynamic therapy and optogenetics. Besides, our approach can also be combined with ghost imaging or compressed sensing to achieve 3D imaging between turbid layers.

EXACT DOSE X-IRRADIATION OF VARIOUS REGIONS OF THE HEAD AND VISUAL SENSATIONS--X-RAY LOCATION METHOD OF STUDY OF THE REACTIVITY OF THE CENTRAL NERVOUS SYSTEM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gurtovoi, G.K.; Burdianskaya, E.O.

1960-01-01

The primary substrate excited by threshold doses of x radiation of the normal human eye causes perception of a light flash in the retinal region. The threshold dose for the retina is about 1 mr; the threshold absorbed dose is about 1 mrad. Persons with a removed eyeball, on irradiation of the operated region with a frontal x-ray beam, perceive a flash of light at definite doses of radiation. Six persons taking part in an experiment saw a flash at doses of 17 to 150 mr (different observers saw flash at different doses) and did not see flash at dosesmore » of 5 to 90 mr. The cause of x-ray phosphene on frontal irradiation of the region of the removed eye with threshold doses is neither the reactivity of the optic nerve stump, the reactivity of the parts of the brain irradiated, nor the sensitivity of the skin receptors. In the cases considered, the cause of x-ray phosphene was irradiation of the retina of the nomnal eye by scattered x rays. The averaged coefficient of scatter was about 2%. On irradiation of the occiptal regions of the brain in subjects with normal eyes at a dose of about 150 mr, one subject perceived a flash of light. In this case, the absorbed dose for the occipital regions of the brain was about 40 mrad. The reason for this phenomenon must be explored. Stimulation of the cerebral formations (after atrophic changes in the visual tract and cortex) by x radia tion with a dose of up to 3 r, did not cause visual sensations. With the disposition of the beam, the absorbed dose for the chiasma was about 1 rad and for the occipital regions about 0.2 rad. In the study of threshold visual sensation and their causes on x irradiation of various regions of the head, it is important to apply defined doses of radiation. Scatter of the x rays in the head must be taken into consideration. (auth)« less

International Conference of Defects in Semiconductors (19th), ICDS, Held in Aveiro, Portugal on July 21-25, 1997, Pt. 3

DTIC Science & Technology

1998-01-23

2 1 ■1 WWW .; 0 100 200 300 400 0 100 200 300 400 0 100 200 300 400 co (Mrad/s) Fig. 1 Characteristic EFG corresponding to type II...results for 1/T -» 0. Materials Science Forum Vols. 258-263 1355 ent, and the quasi-Fermi level, eF, is pinned to the DX level position, eDX . eB...denoted by E plus index. For single electron processes, s = E). The pressure dependence of eDX is shown by squares in Fig. 4. The dashed line shows the

Infrared analysis of polyethylene wear specimens using attenuated total reflection spectroscopy. [effects of radiation on the surface properties of materials for total joint protheses

NASA Technical Reports Server (NTRS)

Jones, W. R.; Lauer, J. L.

1979-01-01

Attenuated total reflection infrared spectroscopy was used to analyze ultrahigh molecular weight polyethylene wear test specimens. Three different specimens were analyzed. One specimen was gamma irradiated to a dose of 5.0 MRad, another to a dose of 2.5 MRad, and the final specimen was unirradiated. There was no conclusive evidence of chemical changes (i.e., unsaturation or oxidation) in the surface regions of any of the polyethylene samples. Therefore, it was concluded that the gamma irradiation sterilization procedure shoud not alter the boundary lubricating properties of the polyethylene.

A compact led lidar system fitted for a mars rover - design and ground experiment

NASA Astrophysics Data System (ADS)

Ong, Prane Mariel B.; Shiina, Tatsuo; Manago, Naohiro; Kuze, Hiroaki; Senshu, Hiroki; Otobe, Naohito; Hashimoto, George; Kawabata, Yasuhiro

2018-04-01

A compact LED lidar was constructed and fieldtested with the aim to observe the Mars' dust devils. To be able to fit it on the Mars rover, a specialized Cassegrain telescope was designed to be within a 10 cm-cube, with a field of view of 3mrad. The transmitter has 385 nm LED light source with 3 cmϕ opening, 70mrad divergence, 0.75W (7.5nJ/10ns) pulse power, and 500 kHz repetition frequency. The configuration of the optical system is biaxial to easily configure the overlap between their optical axes.

Effects of crystallization interfaces on irradiated ferroelectric thin films

NASA Astrophysics Data System (ADS)

Brewer, S. J.; Williams, S. C.; Cress, C. D.; Bassiri-Gharb, N.

2017-11-01

This work investigates the role of crystallization interfaces and chemical heterogeneity in the radiation tolerance of chemical solution-deposited lead zirconate titanate (PZT) thin films. Two sets of PZT thin films were fabricated with crystallization performed at (i) every deposited layer or (ii) every three layers. The films were exposed to a range of 60Co gamma radiation doses, between 0.2 and 20 Mrad, and their functional response was compared before and after irradiation. The observed trends indicate enhancements of dielectric, ferroelectric, and piezoelectric responses at low radiation doses and degradation of the same at higher doses. Response enhancements are expected to result from low-dose (≤2 Mrad), ionizing radiation-induced charging of internal interfaces—an effect that results in neutralization of pre-existing internal bias in the samples. At higher radiation doses (>2 Mrad), accumulation and self-ordering of radiation-modified, mobile, oxygen vacancy-related defects contribute to degradation of dielectric, ferroelectric, and piezoelectric properties, exacerbated in the samples with more crystallization layers, potentially due to increased defect accumulation at these internal interfaces. These results suggest that the interaction between radiation and crystallization interfaces is multifaceted—the effects of ionization, domain wall motion, point defect mobility, and microstructure are considered.

Effect of Ionizing Radiation on the Mechanical and Structural Properties of Graphite Fiber Reinforced Composites. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Wolf, Kay Woodroof

1982-01-01

Graphite/epoxy (T300/5208) and graphite/polyimide composites (C6000/PMR 15) were exposed to various levels of 0.5 MeV electron radiation with the maximum dose being 10,000 Mrad. A three point bending test was used to evaluate the ultimate stress and modulus of the composites. In all composites except transverse samples of C6000/PMR 15 ultimate stress values remained approximately constant or increased slightly. The modulus values remained approximately constant for all composite types regardless of the radiation level. Interfacial aspects of composites were studied. Interlaminar shear tests were performed on T300/5208 and C6000/PMR 15 composites irradiated to 10,000 Mrad. There was an initial increase in interlaminar shear strength (up to 1,000 Mrad) followed by a sharp decrease with further radiation exposure. Using scanning electron microscopy no visual differences in the mode of fracture could be detected between ruptured control samples and those exposed to various levels of radiation. Electron spectroscopy for chemical analysis (ESCA) revealed little change in the surface elements present in control and highly irradiated T300/5208 composite samples.

Self-modulated laser wakefield accelerators as x-ray sources

DOE PAGES

Lemos, N.; Martins, J. L.; Tsung, F. S.; ...

2016-02-17

The development of a directional, small-divergence, and short-duration picosecond x-ray probe beam with an energy greater than 50 keV is desirable for high energy density science experiments. We therefore explore through particle-in-cell (PIC) computer simulations the possibility of using x-rays radiated by betatron-like motion of electrons from a self-modulated laser wakefield accelerator as a possible candidate to meet this need. Two OSIRIS 2D PIC simulations with mobile ions are presented, one with a normalized vector potential a 0 = 1.5 and the other with an a 0 = 3. We find that in both cases direct laser acceleration (DLA) ismore » an important additional acceleration mechanism in addition to the longitudinal electric field of the plasma wave. Together these mechanisms produce electrons with a continuous energy spectrum with a maximum energy of 300 MeV for a 0 = 3 case and 180 MeV in the a 0 = 1.5 case. Forward-directed x-ray radiation with a photon energy up to 100 keV was calculated for the a 0 = 3 case and up to 12 keV for the a 0 = 1.5 case. The x-ray spectrum can be fitted with a sum of two synchrotron spectra with critical photon energies of 13 and 45 keV for the a 0 of 3 and critical photon energies of 0.3 and 1.4 keV for a 0 of 1.5 in the plane of polarization of the laser. As a result, the full width at half maximum divergence angle of the x-rays was 62 × 1.9 mrad for a 0 = 3 and 77 × 3.8 mrad for a 0 = 1.5.« less

Brilliant petawatt gamma-ray pulse generation in quantum electrodynamic laser-plasma interaction

PubMed Central

Chang, H. X.; Qiao, B.; Huang, T. W.; Xu, Z.; Zhou, C. T.; Gu, Y. Q.; Yan, X. Q.; Zepf, M.; He, X. T.

2017-01-01

We show a new resonance acceleration scheme for generating ultradense relativistic electron bunches in helical motions and hence emitting brilliant vortical γ-ray pulses in the quantum electrodynamic (QED) regime of circularly-polarized (CP) laser-plasma interactions. Here the combined effects of the radiation reaction recoil force and the self-generated magnetic fields result in not only trapping of a great amount of electrons in laser-produced plasma channel, but also significant broadening of the resonance bandwidth between laser frequency and that of electron betatron oscillation in the channel, which eventually leads to formation of the ultradense electron bunch under resonant helical motion in CP laser fields. Three-dimensional PIC simulations show that a brilliant γ-ray pulse with unprecedented power of 6.7 PW and peak brightness of 1025 photons/s/mm2/mrad2/0.1% BW (at 15 MeV) is emitted at laser intensity of 1.9 × 1023 W/cm2. PMID:28338010

High brightness gamma-ray production at Fermilab Accelerator Science and Technology (FAST) facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mihalcea, Daniel; Jacobson, B.; Murokh, A.

Electron beams with energies of the order of a few 100's of MeV and low transverse emittance, in combination with powerful infrared lasers, allow for the production of high quality gamma rays through Inverse Compton Scattering (ICS). At Fermilab Accelerator Science and Technology (FAST) facility, a 300 MeV beam will be used to generate gamma rays with maximum photon energies of up to ~1.5 MeV and brightness of the order of 10 21 photons/[s-(mm-mrad) 2- 0.1%BW]. Due to the low electron-beam transverse emittance, the relative bandwidth of the scattered radiation is expected to be ≤ 1%. A key challenge towardmore » the production of high radiation dose and brightness is to enhance the energy of the infrared 3 ps laser pulses to the joule level. Finally, in this contribution, we present the plans for the experimental setup, along with comprehensive numerical simulations of the ICS process.« less

Generation of High Brightness X-rays with the PLEIADES Thomson X-ray Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, W J; Anderson, S G; Barty, C P J

2003-05-28

The use of short laser pulses to generate high peak intensity, ultra-short x-ray pulses enables exciting new experimental capabilities, such as femtosecond pump-probe experiments used to temporally resolve material structural dynamics on atomic time scales. PLEIADES (Picosecond Laser Electron InterAction for Dynamic Evaluation of Structures) is a next generation Thomson scattering x-ray source being developed at Lawrence Livermore National Laboratory (LLNL). Ultra-fast picosecond x-rays (10-200 keV) are generated by colliding an energetic electron beam (20-100 MeV) with a high intensity, sub-ps, 800 nm laser pulse. The peak brightness of the source is expected to exceed 10{sup 20} photons/s/0.1% bandwidth/mm2/mrad2. Simulationsmore » of the electron beam production, transport, and final focus are presented. Electron beam measurements, including emittance and final focus spot size are also presented and compared to simulation results. Measurements of x-ray production are also reported and compared to theoretical calculations.« less

A compact tunable polarized X-ray source based on laser-plasma helical undulators

PubMed Central

Luo, J.; Chen, M.; Zeng, M.; Vieira, J.; Yu, L. L.; Weng, S. M.; Silva, L. O.; Jaroszynski, D. A.; Sheng, Z. M.; Zhang, J.

2016-01-01

Laser wakefield accelerators have great potential as the basis for next generation compact radiation sources because of their extremely high accelerating gradients. However, X-ray radiation from such devices still lacks tunability, especially of the intensity and polarization distributions. Here we propose a tunable polarized radiation source based on a helical plasma undulator in a plasma channel guided wakefield accelerator. When a laser pulse is initially incident with a skew angle relative to the channel axis, the laser and accelerated electrons experience collective spiral motions, which leads to elliptically polarized synchrotron-like radiation with flexible tunability on radiation intensity, spectra and polarization. We demonstrate that a radiation source with millimeter size and peak brilliance of 2 × 1019 photons/s/mm2/mrad2/0.1% bandwidth can be made with moderate laser and electron beam parameters. This brilliance is comparable with third generation synchrotron radiation facilities running at similar photon energies, suggesting that laser plasma based radiation sources are promising for advanced applications. PMID:27377126

High-brightness line generators and fiber-coupled sources based on low-smile laser diode arrays

NASA Astrophysics Data System (ADS)

Watson, J.; Schleuning, D.; Lavikko, P.; Alander, T.; Lee, D.; Lovato, P.; Winhold, H.; Griffin, M.; Tolman, S.; Liang, P.; Hasenberg, T.; Reed, M.

2008-02-01

We describe the performance of diode laser bars mounted on conductive and water cooled platforms using low smile processes. Total smile of <1μm is readily achieved on both In and AuSn based platforms. Combined with environmentally robust lensing, these mounts form the basis of multiple, high-brightness products. Free-space-coupled devices utilizing conductively-cooled bars delivering 100W from a 200μm, 0.22NA fiber at 976nm have been developed for pumping fiber lasers, as well as for materials processing. Additionally, line generators for graphics and materials processing applications have been produced. Starting from single bars mounted on water-cooled packages that do not require de-ionized or pH-controlled water, these line generators deliver over 80W of power into a line with an aspect ratio of 600:1, and have a BPP of <2mm-mrad in the direction orthogonal to the line.

Spherical aberration correction with threefold symmetric line currents.

PubMed

Hoque, Shahedul; Ito, Hiroyuki; Nishi, Ryuji; Takaoka, Akio; Munro, Eric

2016-02-01

It has been shown that N-fold symmetric line current (henceforth denoted as N-SYLC) produces 2N-pole magnetic fields. In this paper, a threefold symmetric line current (N3-SYLC in short) is proposed for correcting 3rd order spherical aberration of round lenses. N3-SYLC can be realized without using magnetic materials, which makes it free of the problems of hysteresis, inhomogeneity and saturation. We investigate theoretically the basic properties of an N3-SYLC configuration which can in principle be realized by simple wires. By optimizing the parameters of a system with beam energy of 5.5keV, the required excitation current for correcting 3rd order spherical aberration coefficient of 400 mm is less than 1AT, and the residual higher order aberrations can be kept sufficiently small to obtain beam size of less than 1 nm for initial slopes up to 5 mrad. Copyright © 2015 Elsevier B.V. All rights reserved.

Anomalous laser deflection phenomenon based on the interaction of electro-optic and graded refractivity effects in Cu-doped KTa{sub 1−x}Nb{sub x}O{sub 3} crystal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Xuping, E-mail: wangxp@sdas.org; Liu, Bing; Yang, Yuguo

2014-08-04

An abnormal laser deflection phenomenon in a copper-doped KTa{sub 1−x}Nb{sub x}O{sub 3} (Cu:KTN) crystal is demonstrated in this Letter. A near-50 mrad beam deflection angle was observed when a voltage of 1.2 kV was applied to a Cu:KTN block with size of 2.8 mm × 1.2 mm × 7.5 mm at room temperature. The special features of this deflection phenomenon are that the laser beam deflection direction is perpendicular to the electric field direction, and the beam deflection angle remains unchanged when the electric field direction is reversed. The operating principle of the phenomenon is investigated and the origin of the deflection phenomenon is attributed to an interactionmore » between the graded refractivity effect and the quadratic electro-optic effect of the crystal.« less

Proton acceleration: new developments for focusing and energy selection, and applications in plasma physics

NASA Astrophysics Data System (ADS)

Audebert, P.

2007-11-01

In the last few years, intense research has been conducted on laser-accelerated ion sources and their applications. These sources have exceptional properties, i.e. high brightness and high spectral cut-off, high directionality and laminarity, short burst duration. We have shown that for proton energies >10 MeV, the transverse and longitudinal emittance are respectively <0.004 mm-mrad and <10-4 eV-s, i.e. at least 100-fold and may be as much as 10^4-fold better than conventional accelerators beams. Thanks to these properties, these sources allow for example point-projection radiography with unprecedented resolution. We will show example of such time and space-resolved radiography of fast evolving fields, either of associated with the expansion of a plasma in vacuum [*] or with the propagation of a ICF-relevant laser beam in an underdense plasma. These proton sources also open new opportunities for ion beam generation and control, and could stimulate development of compact ion accelerators for many applications.

Hard X-ray Wiggler Front End Filter Design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schulte-Schrepping, Horst; Hahn, Ulrich

2007-01-19

The front end filter design and implementation for the new HARWI-II hard X-ray wiggler at DORIS-III at HASYLAB/DESY is presented. The device emits a total power of 30 kW at 150mA storage ring current. The beam has a horizontal width of 3.8mrad and a central power density of 54 W/mm2 at 26m distance to the source. The filter section located in the ring tunnel has been introduced to tailor the thermal loads at the downstream optical components. The high power density and the high total power at the filter section are handled with a layered design. Glassy carbon filters convertmore » the absorbed power into thermal radiation to lower the heat load to an acceptable level for water cooled copper filters. The requirements in beam size and filtering are addressed by separating the filter functions in three units which are switched individually into the beam.« less

ATTO SECOND ELECTRON BEAMS GENERATION AND CHARACTERIZATION EXPERIMENT AT THE ACCELERATOR TEST FACILITY.

DOE Office of Scientific and Technical Information (OSTI.GOV)

ZOLOTOREV, M.; ZHOLENTS, A.; WANG, X.J.

2002-02-01

We are proposing an Atto-second electron beam generation and diagnostics experiment at the Brookhaven Accelerator Test facility (ATF) using 1 {micro}m Inverse Free Electron Laser (IFEL). The proposed experiment will be carried out by an BNL/LBNL collaboration, and it will be installed at the ATF beam line II. The proposed experiment will employ a one-meter long undulator with 1.8 cm period (VISA undulator). The electron beam energy will be 63 MeV with emittance less than 2 mm-mrad and energy spread less than 0.05%. The ATF photocathode injector driving laser will be used for energy modulation by Inverse Free Electron Lasermore » (IFEL). With 10 MW laser peak power, about 2% total energy modulation is expected. The energy modulated electron beam will be further bunched through either a drift space or a three magnet chicane into atto-second electron bunches. The attosecond electron beam bunches will be analyzed using the coherent transition radiation (CTR).« less

Development of a spatially resolved reflectometer to monitor corrosion of solar reflectors

NASA Astrophysics Data System (ADS)

Sutter, Florian; Meyen, Stephanie; Heller, Peter; Pitz-Paal, Robert

2013-06-01

Solar reflectors for Concentrating Solar Power (CSP) concentrators require a high reflectance and high specularity over the whole solar spectrum. During their lifetime of at least 20 years, the reflectors must withstand harsh outdoor conditions without loosing their reflective properties. Currently, there are not many devices available to measure the specular reflectance. In this work a prototype of a specular reflectometer with spatial resolution has been developed. The major advantage of the prototype compared to other reflectometers is the possibility of measuring the specular reflectance on an extended measuring spot of more than 5 cm in diameter with a spatial resolution of 37 pixel/mm. Additionally, measurements can be taken at three different acceptance half angles (φ = 3.5, 6.0, and 12.5 mrad) and at three different wavelengths (λ = 410 nm, 500 nm, and 656 nm). This lab scale instrument can be employed to monitor degradation effects, such as corrosion spots, and evaluate their influence on the specular reflectance of solar mirror materials.

Bright attosecond γ-ray pulses from nonlinear Compton scattering with laser-illuminated compound targets

NASA Astrophysics Data System (ADS)

Zhu, Xing-Long; Chen, Min; Yu, Tong-Pu; Weng, Su-Ming; Hu, Li-Xiang; McKenna, Paul; Sheng, Zheng-Ming

2018-04-01

Attosecond light sources have the potential to open up totally unexplored research avenues in ultrafast science. However, the photon energies achievable using existing generation schemes are limited to the keV range. Here, we propose and numerically demonstrate an all-optical mechanism for the generation of bright MeV attosecond γ-photon beams with desirable angular momentum. Using a circularly polarized Laguerre-Gaussian laser pulse focused onto a cone-foil target, dense attosecond bunches ( ≲ 170 as ) of electrons are produced. The electrons interact with the laser pulse which is reflected by a plasma mirror, producing ultra-brilliant (˜1023 photons/s/mm2/mrad2/0.1%BW) multi-MeV (Eγ,max > 30 MeV) isolated attosecond ( ≲ 260 as ) γ-ray pulse trains. Moreover, the angular momentum is transferred to γ-photon beams via nonlinear Compton scattering of ultra-intense tightly focused laser pulse by energetic electrons. Such a brilliant attosecond γ-photon source would provide the possibilities in attosecond nuclear science.

An all permanent magnet electron cyclotron resonance ion source for heavy ion therapy.

PubMed

Cao, Yun; Li, Jia Qing; Sun, Liang Ting; Zhang, Xue Zhen; Feng, Yu Cheng; Wang, Hui; Ma, Bao Hua; Li, Xi Xia

2014-02-01

A high charge state all permanent Electron Cyclotron Resonance ion source, Lanzhou All Permanent ECR ion source no. 3-LAPECR3, has been successfully built at IMP in 2012, which will serve as the ion injector of the Heavy Ion Medical Machine (HIMM) project. As a commercial device, LAPECR3 features a compact structure, small size, and low cost. According to HIMM scenario more than 100 eμA of C(5+) ion beam should be extracted from the ion source, and the beam emittance better than 75 π*mm*mrad. In recent commissioning, about 120 eμA of C(5+) ion beam was got when work gas was CH4 while about 262 eμA of C(5+) ion beam was obtained when work gas was C2H2 gas. The design and construction of the ion source and its low-energy transportation beam line, and the preliminary commissioning results will be presented in detail in this paper.

Teradiode's high brightness semiconductor lasers

NASA Astrophysics Data System (ADS)

Huang, Robin K.; Chann, Bien; Burgess, James; Lochman, Bryan; Zhou, Wang; Cruz, Mike; Cook, Rob; Dugmore, Dan; Shattuck, Jeff; Tayebati, Parviz

2016-03-01

TeraDiode is manufacturing multi-kW-class ultra-high brightness fiber-coupled direct diode lasers for industrial applications. A fiber-coupled direct diode laser with a power level of 4,680 W from a 100 μm core diameter, <0.08 numerical aperture (NA) output fiber at a single center wavelength was demonstrated. Our TeraBlade industrial platform achieves world-record brightness levels for direct diode lasers. The fiber-coupled output corresponds to a Beam Parameter Product (BPP) of 3.5 mm-mrad and is the lowest BPP multi-kW-class direct diode laser yet reported. This laser is suitable for industrial materials processing applications, including sheet metal cutting and welding. This 4-kW fiber-coupled direct diode laser has comparable brightness to that of industrial fiber lasers and CO2 lasers, and is over 10x brighter than state-of-the-art direct diode lasers. We have also demonstrated novel high peak power lasers and high brightness Mid-Infrared Lasers.

High-power industrial pulsed CO2 laser

NASA Astrophysics Data System (ADS)

Levin, G. I.

1983-12-01

The use of a pulsed TEA CO2 laser (with maximum average power 1.0 kW; maximum pulse energy 3.5 J; repetition frequency 400-600 Hz; half-width pulse duration 15 microsec; circular-coupling-aperture beam diameter 6, 8, or 12 mm; and beam divergence 10 mrad) in industrial welding applications is investigated experimentally in carbon and stainless steels, Zr, Ti, and Ni of various thicknesses. The power required to melt the metals is found to be about 120-200 W/sq cm, or 5-6 times less than that for CW lasers. It is shown that deep narrow-seam welds with mechanical properties identical to those of the bulk metal can be obtained with little or no intercrystalline corrosion or thermal distortion of the surrounding area. Disadvantages such as the 65-dB noise level, low welding speed, formation of an overlap at the top and a crater at the bottom of the weld, and root porosity are considered the primary limitations on the applicability of the device tested.

A new multidimensional diagnostic method for measuring the properties of intense ion beams

NASA Astrophysics Data System (ADS)

Yasuike, Kazuhito; Miyamoto, Shuji; Nakai, Sadao

1996-02-01

A new arrayed pinhole camera (APC) diagnostic method for intense ion beams has been developed. The APC diagnostic technique permits the acquisition of the angular divergences and the ion fluxes of high intensity ion beams, in one shot, with a spatial resolution on the source of better than 1 mm and an effective angular divergence resolution of better than 10 mrad. A prototype time integrated APC has been designed and evaluated. The demonstration experiments have been performed on a Reiden-IV, 1 MV and 1 Ω pulsed power machine [1 T W (tera-watt or trillion watts)]. Proton beams of 0.7 MeV, with a pulse duration of ˜50 ns and an ion current density of about 100 A/cm2, were generated in an applied-Br type ion diode source using paraffin-filled grooves. These experimental results show that the APC can measure nonuniformities in the ion beam intensity generated from the ion source and the dependence of beam angular divergence on ion beam intensity.

Giant collimated gamma-ray flashes

NASA Astrophysics Data System (ADS)

Benedetti, Alberto; Tamburini, Matteo; Keitel, Christoph H.

2018-06-01

Bright sources of high-energy electromagnetic radiation are widely employed in fundamental research, industry and medicine1,2. This motivated the construction of Compton-based facilities planned to yield bright gamma-ray pulses with energies up to3 20 MeV. Here, we demonstrate a novel mechanism based on the strongly amplified synchrotron emission that occurs when a sufficiently dense ultra-relativistic electron beam interacts with a millimetre-thickness conductor. For electron beam densities exceeding approximately 3 × 1019 cm-3, electromagnetic instabilities occur, and the ultra-relativistic electrons travel through self-generated electromagnetic fields as large as 107-108 gauss. This results in the production of a collimated gamma-ray pulse with peak brilliance above 1025 photons s-1 mrad-2 mm-2 per 0.1% bandwidth, photon energies ranging from 200 keV to gigaelectronvolts and up to 60% electron-to-photon energy conversion efficiency. These findings pave the way to compact, high-repetition-rate (kilohertz) sources of short (≲30 fs), collimated (milliradian) and high-flux (>1012 photons s-1) gamma-ray pulses.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Aiwu; Hohlmann, Marcus; Azmoun, Babak

Here, we study the position sensitivity of radial zigzag strips intended to read out large GEM detectors for tracking at future experiments. Zigzag strips can cover a readout area with fewer strips than regular straight strips while maintaining good spatial resolution. Consequently, they can reduce the number of required electronic channels and related cost for large-area GEM detector systems. A non-linear relation between incident particle position and hit position measured from charge sharing among zigzag strips was observed in a previous study. We significantly reduce this non-linearity by improving the interleaving of adjacent physical zigzag strips. Zigzag readout structures aremore » implemented on PCBs and on a flexible foil and are tested using a 10 cm × 10 cm triple-GEM detector scanned with a strongly collimated X-ray gun on a 2D motorized stage. Lastly, angular resolutions of 60–84 μrad are achieved with a 1.37 mrad angular strip pitch at a radius of 784 mm. On a linear scale this corresponds to resolutions below 100 μm.« less

High brightness gamma-ray production at Fermilab Accelerator Science and Technology (FAST) facility

DOE PAGES

Mihalcea, Daniel; Jacobson, B.; Murokh, A.; ...

2017-03-01

Electron beams with energies of the order of a few 100's of MeV and low transverse emittance, in combination with powerful infrared lasers, allow for the production of high quality gamma rays through Inverse Compton Scattering (ICS). At Fermilab Accelerator Science and Technology (FAST) facility, a 300 MeV beam will be used to generate gamma rays with maximum photon energies of up to ~1.5 MeV and brightness of the order of 10 21 photons/[s-(mm-mrad) 2- 0.1%BW]. Due to the low electron-beam transverse emittance, the relative bandwidth of the scattered radiation is expected to be ≤ 1%. A key challenge towardmore » the production of high radiation dose and brightness is to enhance the energy of the infrared 3 ps laser pulses to the joule level. Finally, in this contribution, we present the plans for the experimental setup, along with comprehensive numerical simulations of the ICS process.« less

Beam position reconstruction for the g2p experiment in Hall A at Jefferson lab

NASA Astrophysics Data System (ADS)

Zhu, Pengjia; Allada, Kalyan; Allison, Trent; Badman, Toby; Camsonne, Alexandre; Chen, Jian-ping; Cummings, Melissa; Gu, Chao; Huang, Min; Liu, Jie; Musson, John; Slifer, Karl; Sulkosky, Vincent; Ye, Yunxiu; Zhang, Jixie; Zielinski, Ryan

2016-02-01

Beam-line equipment was upgraded for experiment E08-027 (g2p) in Hall A at Jefferson Lab. Two beam position monitors (BPMs) were necessary to measure the beam position and angle at the target. A new BPM receiver was designed and built to handle the low beam currents (50-100 nA) used for this experiment. Two new super-harps were installed for calibrating the BPMs. In addition to the existing fast raster system, a slow raster system was installed. Before and during the experiment, these new devices were tested and debugged, and their performance was also evaluated. In order to achieve the required accuracy (1-2 mm in position and 1-2 mrad in angle at the target location), the data of the BPMs and harps were carefully analyzed, as well as reconstructing the beam position and angle event by event at the target location. The calculated beam position will be used in the data analysis to accurately determine the kinematics for each event.

Solid-state nanopores of controlled geometry fabricated in a transmission electron microscope

NASA Astrophysics Data System (ADS)

Qian, Hui; Egerton, Ray F.

2017-11-01

Energy-filtered transmission electron microscopy and electron tomography were applied to in situ studies of the formation, shape, and diameter of nanopores formed in a silicon nitride membrane in a transmission electron microscope. The nanopore geometry was observed in three dimensions by electron tomography. Drilling conditions, such as probe current, beam convergence angle, and probe position, affect the formation rate and the geometry of the pores. With a beam convergence semi-angle of α = 22 mrad, a conical shaped nanopore is formed but at α = 45 mrad, double-cone (hourglass-shaped) nanopores were produced. Nanopores with an effective diameter between 10 nm and 1.8 nm were fabricated by controlling the drilling time.

Gamma Radiation Aging Study of a Dow Corning SE 1700 Porous Structure Made by Direct Ink Writing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Small, Ward; Alviso, Cindy T.; Metz, Tom R.

Dow Corning SE 1700 (reinforced polydimethylsiloxane) porous structures were made by direct ink writing (DIW). The specimens (~50% porosity) were subjected to a compressive strain of ~25% while exposed to a gamma radiation dose of 1, 5, or 10 Mrad under vacuum. Compression set and load retention of the aged specimens were measured after a ~24 h relaxation period. Compression set (relative to deflection) increased with radiation dose: 11, 35, and 51% after 1, 5, and 10 Mrad, respectively. Load retention was 96-97% for the doses tested. The SE 1700 compared favorably to M9763 cellular silicone tested under the samemore » conditions.« less

Gamma radiation effects on silicon photonic waveguides.

PubMed

Grillanda, Stefano; Singh, Vivek; Raghunathan, Vivek; Morichetti, Francesco; Melloni, Andrea; Kimerling, Lionel; Agarwal, Anuradha M

2016-07-01

To support the use of integrated photonics in harsh environments, such as outer space, the hardness threshold to high-energy radiation must be established. Here, we investigate the effects of gamma (γ) rays, with energy in the MeV-range, on silicon photonic waveguides. By irradiation of high-quality factor amorphous silicon core resonators, we measure the impact of γ rays on the materials incorporated in our waveguide system, namely amorphous silicon, silicon dioxide, and polymer. While we show the robustness of amorphous silicon and silicon dioxide up to an absorbed dose of 15 Mrad, more than 100× higher than previous reports on crystalline silicon, polymer materials exhibit changes with doses as low as 1 Mrad.

DCS - A high flux beamline for time resolved dynamic compression science – Design highlights

DOE PAGES

Capatina, D.; D’Amico, K.; Nudell, J.; ...

2016-07-27

The Dynamic Compression Sector (DCS) beamline, a national user facility for time resolved dynamic compression science supported by the National Nuclear Security Administration (NNSA) of the Department of Energy (DOE), has recently completed construction and is being commissioned at Sector 35 of the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). The beamline consists of a First Optics Enclosure (FOE) and four experimental enclosures. A Kirkpatrick–Baez focusing mirror system with 2.2 mrad incident angles in the FOE delivers pink beam to the experimental stations. A refocusing Kirkpatrick–Baez mirror system is situated in each of the two most downstream enclosures.more » Experiments can be conducted in either white, monochromatic, pink or monochromatic-reflected beam mode in any of the experimental stations by changing the position of two interlocked components in the FOE. The beamline Radiation Safety System (RSS) components have been designed to handle the continuous beam provided by two in-line revolver undulators with periods of 27 and 30 mm, at closed gap, 150 mA beam current, and passing through a power limiting aperture of 1.5 x 1.0 mm 2. A novel pink beam end station stop [1] is used to stop the continuous and focused pink beam which can achieve a peak heat flux of 105 kW/mm 2. Finally, a new millisecond shutter design [2] is used to deliver a quick pulse of beam to the sample, synchronized with the dynamic event, the microsecond shutter, and the storage ring clock.« less

DCS - A high flux beamline for time resolved dynamic compression science – Design highlights

DOE Office of Scientific and Technical Information (OSTI.GOV)

Capatina, D., E-mail: capatina@aps.anl.gov; D’Amico, K., E-mail: kdamico@aps.anl.gov; Nudell, J., E-mail: jnudell@aps.anl.gov

2016-07-27

The Dynamic Compression Sector (DCS) beamline, a national user facility for time resolved dynamic compression science supported by the National Nuclear Security Administration (NNSA) of the Department of Energy (DOE), has recently completed construction and is being commissioned at Sector 35 of the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). The beamline consists of a First Optics Enclosure (FOE) and four experimental enclosures. A Kirkpatrick–Baez focusing mirror system with 2.2 mrad incident angles in the FOE delivers pink beam to the experimental stations. A refocusing Kirkpatrick–Baez mirror system is situated in each of the two most downstream enclosures.more » Experiments can be conducted in either white, monochromatic, pink or monochromatic-reflected beam mode in any of the experimental stations by changing the position of two interlocked components in the FOE. The beamline Radiation Safety System (RSS) components have been designed to handle the continuous beam provided by two in-line revolver undulators with periods of 27 and 30 mm, at closed gap, 150 mA beam current, and passing through a power limiting aperture of 1.5 x 1.0 mm{sup 2}. A novel pink beam end station stop [1] is used to stop the continuous and focused pink beam which can achieve a peak heat flux of 105 kW/mm{sup 2}. A new millisecond shutter design [2] is used to deliver a quick pulse of beam to the sample, synchronized with the dynamic event, the microsecond shutter, and the storage ring clock.« less

DCS - A High Flux Beamline for Time Resolved Dynamic Compression Science – Design Highlights

DOE Office of Scientific and Technical Information (OSTI.GOV)

Capatina, D.; D'Amico, Kevin L.; Nudell, J.

2016-07-27

The Dynamic Compression Sector (DCS) beamline, a national user facility for time resolved dynamic compression science supported by the National Nuclear Security Administration (NNSA) of the Department of Energy (DOE), has recently completed construction and is being commissioned at Sector 35 of the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). The beamline consists of a First Optics Enclosure (FOE) and four experimental enclosures. A Kirkpatrick–Baez focusing mirror system with 2.2 mrad incident angles in the FOE delivers pink beam to the experimental stations. A refocusing Kirkpatrick–Baez mirror system is situated in each of the two most downstream enclosures.more » Experiments can be conducted in either white, monochromatic, pink or monochromatic-reflected beam mode in any of the experimental stations by changing the position of two interlocked components in the FOE. The beamline Radiation Safety System (RSS) components have been designed to handle the continuous beam provided by two in-line revolver undulators with periods of 27 and 30 mm, at closed gap, 150 mA beam current, and passing through a power limiting aperture of 1.5 x 1.0 mm2. A novel pink beam end station stop [1] is used to stop the continuous and focused pink beam which can achieve a peak heat flux of 105 kW/mm2. A new millisecond shutter design [2] is used to deliver a quick pulse of beam to the sample, synchronized with the dynamic event, the microsecond shutter, and the storage ring clock.« less

Ultrahigh resolution and brilliance laser wakefield accelerator betatron x-ray source for rapid in vivo tomographic microvasculature imaging in small animal models

NASA Astrophysics Data System (ADS)

Fourmaux, Sylvain; Kieffer, Jean-Claude; Krol, Andrzej

2017-03-01

We are developing ultrahigh spatial resolution (FWHM < 2 μm) high-brilliance x-ray source for rapid in vivo tomographic microvasculature imaging micro-CT angiography (μCTA) in small animal models using optimized contrast agent. It exploits Laser Wakefield Accelerator (LWFA) betatron x-ray emission phenomenon. Ultrashort high-intensity laser pulse interacting with a supersonic gas jet produces an ion cavity ("bubble") in the plasma in the wake of the laser pulse. Electrons that are injected into this bubble gain energy, perform wiggler-like oscillations and generate burst of incoherent x-rays with characteristic duration time comparable to the laser pulse duration, continuous synchrotron-like spectral distribution that might extend to hundreds keV, very high brilliance, very small focal spot and highly directional emission in the cone-beam geometry. Such LWFA betatron x-ray source created in our lab produced 1021 -1023 photonsṡ shot-1ṡmrad-2ṡmm-2/0.1%bw with mean critical energy in the12-30 keV range. X-ray source size for a single laser shot was FWHM=1.7 μm x-ray beam divergence 20-30 mrad, and effective focal spot size for multiple shots FWHM= 2 μm. Projection images of simple phantoms and complex biological objects including insects and mice were obtained in single laser shots. We conclude that ultrahigh spatial resolution μCTA (FWHM 2 μm) requiring thousands of projection images could be accomplished using LWFA betatron x-ray radiation in approximately 40 s with our existing 220 TW laser and sub seconds with next generation of ultrafast lasers and x-ray detectors, as opposed to several hours required using conventional microfocal x-ray tubes. Thus, sub second ultrahigh resolution in vivo microtomographic microvasculature imaging (in both absorption and phase contrast mode) in small animal models of cancer and vascular diseases will be feasible with LWFA betatron x-ray source.

Demagnetization of Nd 2Fe 14B, Pr 2Fe 14B, and Sm 2Co 17 Permanent Magnets in Spallation Irradiation Fields

DOE PAGES

Simos, Nikolaos; Ozaki, S.; Mokhov, N.; ...

2018-02-27

Prompted by the need for radiation-resistant permanent magnets for insertion devices (IDs) of high-brilliance next-generation synchrotrons such as the National Synchrotron Light Source II, the demagnetization of Nd 2Fe 14B and Pr 2Fe 14B was studied after exposure to a mixed irradiating field. Degradation and damage of the permanent magnetic material by components of electromagnetic showers induced in magnets by intense high-energy electron beams will alter the magnetic field structure of the IDs. Plate-like Nd 2Fe 14B magnets were irradiated to 1.8 Grad dose and were evaluated against Pr 2Fe 14B magnets irradiated to a lower dose of 20 Mrad.more » In addition, annular Sm 2Co 17 and Nd 2Fe 14B magnets integrated within a ferrofluidic feedthrough (FFFT) rotary seal were also irradiated to dose levels of 2 Grad for Sm 2Co 17 and 20 Mrad for Nd 2Fe 14B. Post-irradiation measurements of the magnetic intensity revealed that severe demagnetization exceeding 85% occurs in Nd 2Fe 14B magnets after only 50 Mrad dose and over 87% for Pr 2Fe 14B after 10 Mrad dose. The annular-shaped Sm 2Co 17 magnets of the FFFTs were almost insensitive to irradiation up to a dose of 2 Grad. Annular-shaped Nd 2Fe 14B magnets also showed resistance to demagnetization, a direct consequence of the annular shape which is characterized by the removal of the stronger demagnetizing field present at the center of a disk-like magnet. As a result, the sensitivity of boron-based permanent magnets to neutron energy (thermal versus fast) was also assessed via specifically designed experiments and discussed.« less

Optimization of the beam crossing angle at the ILC for e+e‑ and γ γ collisions

NASA Astrophysics Data System (ADS)

Telnov, V. I.

2018-03-01

At this time, the design of the International Linear Collider (ILC) is optimized for e+e‑ collisions; the photon collider (γ γ and >=) is considered as an option. Unexpected discoveries, such as the diphoton excess digamma(750) seen at the LHC, could strongly motivate the construction of a photon collider. In order to enable the γ γ collision option, the ILC design should be compatible with it from the very beginning. In this paper, we discuss the problem of the beam crossing angle. In the ILC technical design [1], this angle is 14 mrad, which is just enough to provide enough space for the final quadrupoles and outgoing beams. For γ γ collisions, the crossing angle must be larger because the low-energy electrons that result from multiple Compton scattering get large disruption angles in collisions with the opposing electron beam and some deflection in the solenoidal detector field. For a 2E0=500 GeV collider, the required crossing angle is about 25 mrad. In this paper, we consider the factors that determine the crossing angle as well as its minimum permissible value that does not yet cause a considerable reduction of the γ γ luminosity. It is shown that the best solution is to increase the laser wavelength from the current 1 μm (which is optimal for 2E0=500 GeV) to 2 μm as this makes possible achieving high γ γ luminosities at a crossing angle of 20 mrad, which is also quite comfortable for e+e‑ collisions, does not cause any degradation of the e+e‑ luminosity and opens the possibility for a more energetic future collider in the same tunnel (e.g., CLIC). Moreover, the 2 μm wavelength is optimal for a 2E0 = 1 TeV collider, e.g., a possible ILC energy upgrade. Please consider this paper an appeal to increase the ILC crossing angle from 14 to 20 mrad.

Demagnetization of Nd 2Fe 14B, Pr 2Fe 14B, and Sm 2Co 17 Permanent Magnets in Spallation Irradiation Fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simos, Nikolaos; Ozaki, S.; Mokhov, N.

Prompted by the need for radiation-resistant permanent magnets for insertion devices (IDs) of high-brilliance next-generation synchrotrons such as the National Synchrotron Light Source II, the demagnetization of Nd 2Fe 14B and Pr 2Fe 14B was studied after exposure to a mixed irradiating field. Degradation and damage of the permanent magnetic material by components of electromagnetic showers induced in magnets by intense high-energy electron beams will alter the magnetic field structure of the IDs. Plate-like Nd 2Fe 14B magnets were irradiated to 1.8 Grad dose and were evaluated against Pr 2Fe 14B magnets irradiated to a lower dose of 20 Mrad.more » In addition, annular Sm 2Co 17 and Nd 2Fe 14B magnets integrated within a ferrofluidic feedthrough (FFFT) rotary seal were also irradiated to dose levels of 2 Grad for Sm 2Co 17 and 20 Mrad for Nd 2Fe 14B. Post-irradiation measurements of the magnetic intensity revealed that severe demagnetization exceeding 85% occurs in Nd 2Fe 14B magnets after only 50 Mrad dose and over 87% for Pr 2Fe 14B after 10 Mrad dose. The annular-shaped Sm 2Co 17 magnets of the FFFTs were almost insensitive to irradiation up to a dose of 2 Grad. Annular-shaped Nd 2Fe 14B magnets also showed resistance to demagnetization, a direct consequence of the annular shape which is characterized by the removal of the stronger demagnetizing field present at the center of a disk-like magnet. As a result, the sensitivity of boron-based permanent magnets to neutron energy (thermal versus fast) was also assessed via specifically designed experiments and discussed.« less

Construction and Design of a full size sTGC prototype for the ATLAS New Small Wheel upgrade

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

For the forthcoming Phase-I upgrade to the LHC (2018/19), the first station of the ATLAS muon end-cap system, Small Wheel, will need to be replaced. The New Small Wheel (NSW) will have to operate in a high background radiation region while reconstructing muon tracks with high precision as well as furnishing information for the Level-1 trigger. In particular, the precision reconstruction of tracks requires a spatial resolution of about 100 μm, and the Level-1 trigger track segments have to be reconstructed with an angular resolution of approximately 1 mrad. The NSW will have two chamber technologies, one primarily devoted tomore » the Level-1 trigger function the small-strip Thin Gap Chambers (sTGC) and one dedicated to precision tracking, Micromegas detectors, (MM). The single sTGC planes of a quadruplet consists of an anode layer of 50 μm gold plated tungsten wire sandwiched between two resistive cathode layers. Behind one of the resistive cathode layers, a PCB with precise machined strips (thus the name sTGC's) spaced every 3.2 mm allows to achieve the position resolution that ranges from 70 to 150 μm, depending on the incident particle angle. Behind the second cathode, a PCB that contains an arrangement of pads, allows for a fast coincidence between successive sTGC layers to tag the passage of a track and reads only the corresponding strips for triggering. To be able to profit from the high accuracy of each of the sTGC planes for trigger purposes, their relative geometrical position between planes has to be controlled to within a precision of about 40 μm in their parallelism, as well (due to the various incident angles), to within a precision of 80 μm in the relative distance between the planes to achieve the overall angular resolution of 1 mrad. The needed accuracy in the position and parallelism of the strips is achieved by machining brass inserts together when machining the strip patterns into the cathode boards in a single step. The inserts can then be used as external references on a granite table. Precision methods are used to maintain high accuracy when combining four single detector gaps first into two doublets and then into a quadruplet. We will present results on the ongoing construction of full size (∼1 x 1 m) sTGC quadruplet prototypes before full construction starts in 2015. (authors)« less

Disc displacement and changes in condylar position

PubMed Central

Ikeda, K; Kawamura, A

2013-01-01

Objectives: To determine whether disc displacement (DD) can be a factor causing changes in condylar position in the glenoid fossa, using limited cone beam CT (LCBCT) images taken in the same time period as MRI that verified DD. Methods: The study included 60 joints in 57 male and female subjects aged 12–20 years (mean age 14.8 years). Subjects fulfilling the inclusion criteria were enrolled from a pool of post-orthodontic patients, and divided into four groups according to their disc status confirmed by MRI: partial DD (PDD), total DD with reduction (TDDWR), lateral DD (LDD) and medial DD (MDD). Changes in joint space from previously reported norms were measured on LCBCT images. Results: In PDD, the condyles were displaced posteriorly in the fossae with a mean anterior space of 2.7 ± 0.5 mm (normal 1.3 ± 0.2 mm) and a posterior space of 1.8 ± 0.4 mm (normal 2.1 ± 0.3 mm). In TDDWR, the condyles were displaced not only posteriorly as observed in PDD, but also vertically with a reduced superior space of 1.9 ± 0.4 mm (normal 2.5 ± 0.5 mm). In LDD, the lateral space was significantly increased to 2.5 ± 0.3 mm (normal 1.8 ± 0.4 mm), while central and medial spaces were significantly decreased to 2.2 ± 0.5 mm (normal 2.7 ± 0.5 mm) and 1.7 ± 0.4 mm (normal 2.4 ± 0.5 mm), respectively. In MDD, the medial space was increased and the lateral and central spaces were significantly decreased. Conclusions: These results indicate that DD in adolescents and young adults can cause the condyle to change its position in the fossa with alterations in joint space which depend on the direction and extent of DD. PMID:22933537

Two-photon photoemission from a copper cathode in an Χ-band photoinjector

DOE PAGES

Li, H.; Limborg-Deprey, C.; Adolphsen, C.; ...

2016-02-24

This study presents two-photon photoemission from a copper cathode in an X-band photoinjector. We experimentally verified that the electron bunch charge from photoemission out of a copper cathode scales with laser intensity (I) square for 400 nm wavelength photons. We compare this two-photon photoemission process with the single photon process at 266 nm. Despite the high reflectivity (R) of the copper surface for 400 nm photons (R=0.48) and higher thermal energy of photoelectrons (two-photon at 200 nm) compared to 266 nm photoelectrons, the quantum efficiency of the two-photon photoemission process (400 nm) exceeds the single-photon process (266 nm) when themore » incident laser intensity is above 300 GW/cm 2. At the same laser pulse energy (E) and other experimental conditions, emitted charge scales inversely with the laser pulse duration. A thermal emittance of 2.7 mm-mrad per mm root mean square (rms) was measured on our cathode which exceeds by sixty percent larger compared to the theoretical predictions, but this discrepancy is similar to previous experimental thermal emittance on copper cathodes with 266 nm photons. The damage of the cathode surface of our first-generation X-band gun from both rf breakdowns and laser impacts mostly explains this result. Using a 400 nm laser can substantially simplify the photoinjector system, and make it an alternative solution for compact pulsed electron sources.« less

PEP as a synchrotron radiation source (invited)

NASA Astrophysics Data System (ADS)

Bienenstock, A.; Brown, G.; Wiedemann, H.; Winick, H.

1989-07-01

The 16-GeV storage ring PEP has characteristics which enable it to operate in modes with very low emittance and to accommodate very long undulators, producing synchrotron radiation at x-ray wavelengths with extremely high brightness and coherent power. Two beamlines, each illuminated by a 2-m long, 77-mm period undulator magnet, are now operational and others are planned. In parasitic operation during colliding-beam runs at 14.5 GeV, these beamlines provide photons above 10 keV with a peak brightness of about 1016 photons/(s mm2 mrad2 ) within a 0.1% bandwidth. In low-emittance tests at 7.1 GeV, horizontal emittances of about 5 nm rad were measured, which is about the same as that planned for the new third-generation x-ray sources. With a current of 15 mA at 7.1 GeV, the present undulators deliver photon beams from 2.7 to 14 keV with a peak brightness of about 1017 . Higher performance levels are expected with the implementation of longer undulators and shorter period undulators. In the longer term, because of its large circumference and long straight sections, PEP could be further developed to achieve even higher performance levels with an emittance below 1 nm rad, very long undulators and picosecond bunches, resulting in one to two orders of magnitude higher brightness and coherent power.

Safe Zone Quantification of the Third Sacral Segment in Normal and Dysmorphic Sacra.

PubMed

Hwang, John S; Reilly, Mark C; Shaath, Mohammad K; Changoor, Stuart; Eastman, Jonathan; Routt, Milton Lee Chip; Sirkin, Michael S; Adams, Mark R

2018-04-01

To quantify the osseous anatomy of the dysmorphic third sacral segment and assess its ability to accommodate internal fixation. Retrospective chart review of a trauma database. University Level 1 Trauma Center. Fifty-nine patients over the age of 18 with computed tomography scans of the pelvis separated into 2 groups: a group with normal pelvic anatomy and a group with sacral dysmorphism. The sacral osseous area was measured on computed tomography scans in the axial, coronal, and sagittal planes in normal and dysmorphic pelves. These measurements were used to determine the possibility of accommodating a transiliac transsacral screw in the third sacral segment. In the normal group, the S3 coronal transverse width averaged 7.71 mm and the S3 axial transverse width averaged 7.12 mm. The mean S3 cross-sectional area of the normal group was 55.8 mm. The dysmorphic group was found to have a mean S3 coronal transverse width of 9.49 mm, an average S3 axial transverse width of 9.14 mm, and an S3 cross-sectional area of 77.9 mm. The third sacral segment of dysmorphic sacra has a larger osseous pathway available to safely accommodate a transiliac transsacral screw when compared with normal sacra. The S3 segment of dysmorphic sacra can serve as an additional site for screw placement when treating unstable posterior pelvic ring fractures.

The effect of uterine motion and uterine margins on target and normal tissue doses in intensity modulated radiation therapy of cervical cancer

NASA Astrophysics Data System (ADS)

Gordon, J. J.; Weiss, E.; Abayomi, O. K.; Siebers, J. V.; Dogan, N.

2011-05-01

In intensity modulated radiation therapy (IMRT) of cervical cancer, uterine motion can be larger than cervix motion, requiring a larger clinical target volume to planning target volume (CTV-to-PTV) margin around the uterine fundus. This work simulates different motion models and margins to estimate the dosimetric consequences. A virtual study used image sets from ten patients. Plans were created with uniform margins of 1 cm (PTVA) and 2.4 cm (PTVC), and a margin tapering from 2.4 cm at the fundus to 1 cm at the cervix (PTVB). Three inter-fraction motion models (MM) were simulated. In MM1, all structures moved with normally distributed rigid body translations. In MM2, CTV motion was progressively magnified as one moved superiorly from the cervix to the fundus. In MM3, both CTV and normal tissue motion were magnified as in MM2, modeling the scenario where normal tissues move into the void left by the mobile uterus. Plans were evaluated using static and percentile DVHs. For a conventional margin (PTVA), quasi-realistic uterine motion (MM3) reduces fundus dose by about 5 Gy and increases normal tissue volumes receiving 30-50 Gy by ~5%. A tapered CTV-to-PTV margin can restore fundus and CTV doses, but will increase normal tissue volumes receiving 30-50 Gy by a further ~5%.

Total Ionizing Dose Effects on Strained Ge pMOS FinFETs on Bulk Si

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, En Xia; Fleetwood, Daniel M.; Hachtel, Jordan A.

2016-12-02

In this paper, we have characterized the total ionizing dose response of strained Ge p MOS FinFETs built on bulk Si using a fin replacement process. Devices irradiated to 1.0 Mrad(SiO 2) show minimal transconductance degradation (less than 5%), very small V th shifts (less than 40 mV in magnitude) and very little ON/OFF current ratio degradation (<5%), and only modest variation in radiation response with transistor geometry (typically less than normal part-to-part variation). Both before and after irradiation, the performance of these strained Ge p MOS FinFETs is far superior to that of past generations of planar Ge pmore » MOS devices. Finally, these improved properties result from significant improvements in processing technology, as well as the enhanced gate control provided by the strained Ge FinFET technology.« less

Attainment of 40.5 pm spatial resolution using 300 kV scanning transmission electron microscope equipped with fifth-order aberration corrector.

PubMed

Morishita, Shigeyuki; Ishikawa, Ryo; Kohno, Yuji; Sawada, Hidetaka; Shibata, Naoya; Ikuhara, Yuichi

2018-02-01

The achievement of a fine electron probe for high-resolution imaging in scanning transmission electron microscopy requires technological developments, especially in electron optics. For this purpose, we developed a microscope with a fifth-order aberration corrector that operates at 300 kV. The contrast flat region in an experimental Ronchigram, which indicates the aberration-free angle, was expanded to 70 mrad. By using a probe with convergence angle of 40 mrad in the scanning transmission electron microscope at 300 kV, we attained the spatial resolution of 40.5 pm, which is the projected interatomic distance between Ga-Ga atomic columns of GaN observed along [212] direction.

Integration of an On-Axis General Sun-Tracking Formula in the Algorithm of an Open-Loop Sun-Tracking System

PubMed Central

Chong, Kok-Keong; Wong, Chee-Woon; Siaw, Fei-Lu; Yew, Tiong-Keat; Ng, See-Seng; Liang, Meng-Suan; Lim, Yun-Seng; Lau, Sing-Liong

2009-01-01

A novel on-axis general sun-tracking formula has been integrated in the algorithm of an open-loop sun-tracking system in order to track the sun accurately and cost effectively. Sun-tracking errors due to installation defects of the 25 m2 prototype solar concentrator have been analyzed from recorded solar images with the use of a CCD camera. With the recorded data, misaligned angles from ideal azimuth-elevation axes have been determined and corrected by a straightforward changing of the parameters' values in the general formula of the tracking algorithm to improve the tracking accuracy to 2.99 mrad, which falls below the encoder resolution limit of 4.13 mrad. PMID:22408483

Ultrasonographic features of normalization of the pylorus after pyloromyotomy for hypertrophic pyloric stenosis.

PubMed

Yoshizawa, J; Eto, T; Higashimoto, Y; Saitou, T; Maie, M

2001-04-01

The purpose of this study was to describe the time course, early postoperative changes, and morphologic features of normalization of the pylorus after pyloromyotomy for hypertrophic pyloric stenosis. The subjects were 17 infants (9 boys, 8 girls) who underwent umbilical incision Ramstedt pyloromyotomy. The pyloric muscle mass was measured immediately before the operation and then at intervals from 3 days to 6 months after the operation using a 7.5-MHz ultrasound probe. In longitudinal section, the dorsal part of the pyloric muscle thickened transiently and then thinned to normal values by 5 months after the operation. It was 5.1 +/- 0.8 mm (mean +/- SD) preoperatively, increased to 6.0 +/- 0.3 mm by day 3 after the operation (P <.05), and thinned to 2.8 +/- 0.2 mm by 5 months after the operation. Concomitantly, the length of the pylorus gradually decreased (from 20.1 +/- 2.9 mm preoperatively to 16.9 +/- 2.7 mm by 3 days postoperatively [P <.05] and to less than 15 mm, by 4 months). In transverse section, the muscle normalized as in the longitudinal section. At the site of the incision it was 4.3 +/- 0.4 mm thick preoperatively, thickened to 4.6 +/- 0.4 mm by 3 days after the operation (P <.05), thinned to 2.1 +/- 0.9 mm by 7 days (P <.05), and then increased slightly, but always was less than 3.0 mm. Morphologically, in transverse section, the incised area looked like a wedge by 3 days after the operation. After pyloromyotomy for hypertrophic pyloric stenosis, there is an early transient increase in muscle thickness within the first few postoperative days followed by a slow decrease that reaches normal thickness (<3 mm) by 5 months. This decrease in thickness is accompanied by a gradual decrease in length to 75% of the preoperative value by 5 months. The morphologic features in this normalization are first a wedge (day 3), then a flat tire (days 7 and 14), and finally an elongated ring (5 months). J Pediatr Surg 36:582-586. Copyright 2001 by W.B. Saunders Company.

Beam dynamic simulations of the CLIC crab cavity and implications on the BDS

NASA Astrophysics Data System (ADS)

Shinton, I. R. R.; Burt, G.; Glasman, C. J.; Jones, R. M.; Wolski, A.

2011-11-01

The Compact Linear Collider (CLIC) is a proposed electron positron linear collider design aiming to achieve a centre of mass energy of up to 3 TeV. The main accelerating structures in CLIC operate at an X-band frequency of 11.994 GHz with an accelerating gradient of 100 MV/m. The present design requires the beams to collide at a small crossing angle of 10 mrad per line giving a resultant overall crossing angle of 20 mrad. Transverse deflecting cavities, referred to as "Crab cavities", are installed in the beam delivery system (BDS) of linear collider designs in order to ensure the final luminosity at the interaction point (IP) is comparable to that in a head on collision. We utilise the beam tracking code PLACET combined with the beam-beam code GUINEA-PIG to calculate the resulting luminosity at the IP. We follow a similar tuning procedure to that used for the design of the ILC crab cavities and anitcrab cavities. However an unexpected loss in luminosity of 10% was observed for the 20 mrad design was observed. It was discovered that the action of the crab cavities can affect the geometric aberrations resulting from the sextupoles used to correct chromatic effects in the beam delivery system. This has direct consequences regarding the design of the present CLIC BDS.

Histomorphometric study of basilar artery in normal and suicide persons.

PubMed

Parmar, Suresh Kumar; Prasad, V Satya

2016-10-01

Depression in association with cerebro-vascular risk factors and white matter lesions is increasingly referred to as 'vascular depression'. There are several brain areas known for playing a role in patho-physiology of depression which may lead to suicidal tendencies, are fed by basilar artery. Therefore, the arterial histoarchitecture was studied in the normal and suicide individuals to establish a relationship between the vascular structural changes and depression. 40 post-mortem samples (both sexes) of basilar artery have been collected and were grouped into normal and suicide groups. Samples were measured for arterial, lumen diameter and the thickness of tunica intima, media and adventitia using H & E stained sections. While, Orcein stained sections were used to estimate the volume fraction of elastic fibres, and Van Gieson stained sections to estimate the volume fraction of collagen fibres. The mean thickness of tunica media of basilar artery in suicide individuals (1.08 microns) showed a statistically significant decrease when compared to normal person (1.33 microns). Further, volume fraction of collagen (0.06 mm 3 /mm 3 ) and elastic fibres (0.06 mm 3 /mm 3 ) in suicide persons showed a statistically significant decrease when compared to normal person (collagen fibres 0.08 mm 3 /mm 3 ; elastic fibres 0.09 mm 3 /mm 3 ). This study establishes a probable causative relationship between vascular structural abnormality and depression which may drive the individual to commit suicide. Copyright © 2016 Chang Gung University. Published by Elsevier B.V. All rights reserved.

A study of the effect of in-line and perpendicular magnetic fields on beam characteristics of electron guns in medical linear accelerators.

PubMed

Constantin, Dragoş E; Fahrig, Rebecca; Keall, Paul J

2011-07-01

Using magnetic resonance imaging (MRI) for real-time guidance during radiotherapy is an active area of research and development. One aspect of the problem is the influence of the MRI scanner, modeled here as an external magnetic field, on the medical linear accelerator (linac) components. The present work characterizes the behavior of two medical linac electron guns with external magnetic fields for in-line and perpendicular orientations of the linac with respect to the MRI scanner. Two electron guns, Litton L-2087 and Varian VTC6364, are considered as representative models for this study. Emphasis was placed on the in-line design approach in which case the MRI scanner and the linac axes of symmetry coincide and assumes no magnetic shielding of the linac. For the in-line case, the magnetic field from a 0.5 T open MRI (GE Signa SP) magnet with a 60 cm gap between its poles was computed and used in full three dimensional (3D) space charge simulations, whereas for the perpendicular case the magnetic field was constant. For the in-line configuration, it is shown that the electron beam is not deflected from the axis of symmetry of the gun and the primary beam current does not vanish even at very high values of the magnetic field, e.g., 0.16 T. As the field strength increases, the primary beam current has an initial plateau of constant value after which its value decreases to a minimum corresponding to a field strength of approximately 0.06 T. After the minimum is reached, the current starts to increase slowly. For the case when the beam current computation is performed at the beam waist position the initial plateau ends at 0.016 T for Litton L-2087 and at 0.012 T for Varian VTC6364. The minimum value of the primary beam current is 27.5% of the initial value for Litton L-2087 and 22.9% of the initial value for Varian VTC6364. The minimum current is reached at 0.06 and 0.062 T for Litton L-2087 and Varian VTC6364, respectively. At 0.16 T the beam current increases to 40.2 and 31.4% from the original value of the current for Litton L-2087 and Varian VTC6364, respectively. In contrast, for the case when the electron gun is perpendicular to the magnetic field, the electron beam is deflected from the axis of symmetry even at small values of the magnetic field. As the strength of the magnetic field increases, so does the beam deflection, leading to a sharp decrease of the primary beam current which vanishes at about 0.007 T for Litton L-2087 and at 0.006 T for Varian VTC6364, respectively. At zero external field, the beam rms emittance computed at beam waist is 1.54 and 1.29n-mm-mrad for Litton L-2087 and Varian VTC6364, respectively. For the inline configuration, there are two particular values of the external field where the beam rms emittance reaches a minimum. Litton L-2087 rms emittance reaches a minimum of 0.72n and 2.01 n-mm-mrad at 0.026 and 0.132 T, respectively. Varian VTC6364 rms emittance reaches a minimum of 0.34n and 0.35n-mm-mrad at 0.028 and 0.14 T, respectively. Beam radius dependence on the external field is shown for the in-line configuration for both electron guns. 3D space charge simulation of two electron guns, Litton L-2087 and Varian VTC6364, were performed for in-line and perpendicular external magnetic fields. A consistent behavior of Pierce guns in external magnetic fields was proven. For the in-line configuration, the primary beam current does not vanish but a large reduction of beam current (up to 77.1%) is observed at higher field strengths; the beam directionality remains unchanged. It was shown that for a perpendicular configuration the current vanishes due to beam bending under the action of the Lorentz force. For in-line configuration it was determined that the rms beam emittance reaches two minima for relatively high values of the external magnetic field.

A study of the effect of in-line and perpendicular magnetic fields on beam characteristics of electron guns in medical linear accelerators

PubMed Central

Constantin, Dragoş E.; Fahrig, Rebecca; Keall, Paul J.

2011-01-01

Purpose: Using magnetic resonance imaging (MRI) for real-time guidance during radiotherapy is an active area of research and development. One aspect of the problem is the influence of the MRI scanner, modeled here as an external magnetic field, on the medical linear accelerator (linac) components. The present work characterizes the behavior of two medical linac electron guns with external magnetic fields for in-line and perpendicular orientations of the linac with respect to the MRI scanner. Methods: Two electron guns, Litton L-2087 and Varian VTC6364, are considered as representative models for this study. Emphasis was placed on the in-line design approach in which case the MRI scanner and the linac axes of symmetry coincide and assumes no magnetic shielding of the linac. For the in-line case, the magnetic field from a 0.5 T open MRI (GE Signa SP) magnet with a 60 cm gap between its poles was computed and used in full three dimensional (3D) space charge simulations, whereas for the perpendicular case the magnetic field was constant. Results: For the in-line configuration, it is shown that the electron beam is not deflected from the axis of symmetry of the gun and the primary beam current does not vanish even at very high values of the magnetic field, e.g., 0.16 T. As the field strength increases, the primary beam current has an initial plateau of constant value after which its value decreases to a minimum corresponding to a field strength of approximately 0.06 T. After the minimum is reached, the current starts to increase slowly. For the case when the beam current computation is performed at the beam waist position the initial plateau ends at 0.016 T for Litton L-2087 and at 0.012 T for Varian VTC6364. The minimum value of the primary beam current is 27.5% of the initial value for Litton L-2087 and 22.9% of the initial value for Varian VTC6364. The minimum current is reached at 0.06 and 0.062 T for Litton L-2087 and Varian VTC6364, respectively. At 0.16 T the beam current increases to 40.2 and 31.4% from the original value of the current for Litton L-2087 and Varian VTC6364, respectively. In contrast, for the case when the electron gun is perpendicular to the magnetic field, the electron beam is deflected from the axis of symmetry even at small values of the magnetic field. As the strength of the magnetic field increases, so does the beam deflection, leading to a sharp decrease of the primary beam current which vanishes at about 0.007 T for Litton L-2087 and at 0.006 T for Varian VTC6364, respectively. At zero external field, the beam rms emittance computed at beam waist is 1.54 and 1.29π-mm-mrad for Litton L-2087 and Varian VTC6364, respectively. For the in-line configuration, there are two particular values of the external field where the beam rms emittance reaches a minimum. Litton L-2087 rms emittance reaches a minimum of 0.72π and 2.01π-mm-mrad at 0.026 and 0.132 T, respectively. Varian VTC6364 rms emittance reaches a minimum of 0.34π and 0.35π-mm-mrad at 0.028 and 0.14 T, respectively. Beam radius dependence on the external field is shown for the in-line configuration for both electron guns. Conclusions: 3D space charge simulation of two electron guns, Litton L-2087 and Varian VTC6364, were performed for in-line and perpendicular external magnetic fields. A consistent behavior of Pierce guns in external magnetic fields was proven. For the in-line configuration, the primary beam current does not vanish but a large reduction of beam current (up to 77.1%) is observed at higher field strengths; the beam directionality remains unchanged. It was shown that for a perpendicular configuration the current vanishes due to beam bending under the action of the Lorentz force. For in-line configuration it was determined that the rms beam emittance reaches two minima for relatively high values of the external magnetic field. PMID:21859019

Dynamic Changes of Pulmonary Arterial Pressure and Ductus Arteriosus in Human Newborns From Birth to 72 Hours of Age

PubMed Central

Kang, Chunmiao; Zhao, Enfa; Zhou, Yinghua; Zhao, Huayun; Liu, Yunyao; Gao, Ningning; Huang, Xiaoxin; Liu, Baomin

2016-01-01

Abstract Normal pulmonary artery pressure and pulmonary hypertension assessment of newborns is rarely reported. The aim of the study is to explore dynamic changes of pulmonary arterial pressure and ductus arteriosus in human newborns from birth to 72 h of age with echocardiography. A total of 76 cases of normal newborns were prospectively detected by echocardiography after birth of 2 h, 6 h, 12 h, 24 h, 48 h, and 72 h, respectively. Ductus arteriosus diameter, blood shunt direction, blood flow velocity, and pressure gradient were recorded. The brachial artery blood pressure were measured to estimate the pulmonary artery systolic pressure (PASP) and pulmonary artery diastolic pressure (PADP) using patent ductus arteriosus pressure gradient method. The mean pulmonary artery pressure (PAMP) were calculated by equation of PAMP = PADP + 1/3(PASP-PADP). (1) There were 76 cases of normal newborns. Among them, 29 cases (38%) ductus arteriosus closed within 24 h, 59 cases (78%) closed within 48 h, 72 cases (95%) closed within 72 h, and 4 cases (5%) ductus arteriosus not closed within 72 h. (2) The ductus arteriosus diameter of 2 h, 6 h, 12 h, 24 h, 48 h, and 72 h after birth was 4.60 ± 0.59 mm, 3.37 ± 0.59 mm, 2.47 ± 0.49 mm, 1.89 ± 0.41 mm, 1.61 ± 0.35 mm, and 1.20 ± 0.24 mm, respectively. Compared all of the ductus arteriosus diameter of the above time periods, there were statistically differences with P < 0.05, respectively. (3) The mean PASP in 2 h, 6 h, 12 h, 24 h, 48 h, 72 h after birth were 76.58 ± 7.28 mm Hg, 65.53 ± 9.25mm Hg, 52.51 ± 9.07 mm Hg, 43.83 ± 7.90 mm Hg, 38.07 ± 8.26 mm Hg, and 36 ± 6.48 mm Hg, respectively. The PADP of the above time period were 37.88 ± 5.56 mm Hg, 29.93 ± 7.91 mm Hg, 23.43 ± 7.37 mm Hg, 19.70 ± 8.51 mm Hg, 13.85 ± 5.58 mm Hg, 13.25 ± 6.18 mm Hg, respectively. The PAMP of the above time period were 63.41 ± 7.03 mm Hg, 51.78 ± 9.82 mm Hg, 40.94 ± 9.32 mm Hg, 34.39 ± 9.89 mm Hg, 26.23 ± 7.49 mm Hg, 25.25 ± 8.29 mm Hg, respectively. There were statistically differences with P < 0.05 between each time periods of PASP, PADP, and PAMP. (4) The upper 95% limit reference range of PASP of normal newborns of 72 h after birth were 39.97 mm Hg. (1) Normal newborns ductus arteriosus diameter gradually decreased after birth, and 95% of them spontaneous closed within 24 to 72 h. (2) Normal newborns pulmonary artery pressure showed a gradually decline after birth, the upper 95% limit reference range for PASP measured in normal newborns <72 h of age was 39.97 mm Hg. Therefore, the diagnostic criteria of newborns pulmonary hypertension may be >40.00 mm Hg according to our limited study. PMID:26817918

Machine Protection System for the Stepper Motor Actuated SyLMAND Mirrors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Subramanian, V. R.; Dolton, W.; Wells, G.

2010-06-23

SyLMAND, the Synchrotron Laboratory for Micro and Nano Devices at the Canadian Light Source, consists of a dedicated X-ray lithography beamline on a bend magnet port, and process support laboratories in a clean room environment. The beamline includes a double mirror system with flat, chromium-coated silicon mirrors operated at varying grazing angles of incidence (4 mrad to 45 mrad) for spectral adjustment by high energy cut-off. Each mirror can be independently moved by two stepper motors to precisely control the pitch and vertical position. We present in this paper the machine protection system implemented in the double mirror system tomore » allow for safe operation of the two mirrors and to avoid consequences of potential stepper motor malfunction.« less

A 0.18 micrometer CMOS Thermopile Readout ASIC Immune to 50 MRAD Total Ionizing Dose (SI) and Single Event Latchup to 174MeV-cm(exp 2)/mg

NASA Technical Reports Server (NTRS)

Quilligan, Gerard T.; Aslam, Shahid; Lakew, Brook; DuMonthier, Jeffery J.; Katz, Richard B.; Kleyner, Igor

2014-01-01

Radiation hardened by design (RHBD) techniques allow commercial CMOS circuits to operate in high total ionizing dose and particle fluence environments. Our radiation hard multi-channel digitizer (MCD) ASIC (Figure 1) is a versatile analog system on a chip (SoC) fabricated in 180nm CMOS. It provides 18 chopper stabilized amplifier channels, a 16- bit sigma-delta analog-digital converter (SDADC) and an on-chip controller. The MCD was evaluated at Goddard Space Flight Center and Texas A&M University's radiation effects facilities and found to be immune to single event latchup (SEL) and total ionizing dose (TID) at 174 MeV-cm(exp 2)/mg and 50 Mrad (Si) respectively.

EFFECT OF MODERATE DOSES OF GAMMA RADIATION ON THE KEEPING QUALITY OF BILBERRIES (VACCINIUM MYRTILLUS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Horubala, A.; Pijanowski, E.

1961-01-01

Three batches of bilberries (European blueberries) in small polythene bags were treated with various doses of gamma radiation and kept afterwards either at ambient or cool storage temperatures for about 10 to 25 days. The dose of about 0.3 Mrad caused the destruction of somewhat more than 99% of the original microflora (bacteria, yeasts and moulds) and thus increased by 250 to 300% the storage life of berries in comparison with untreated fruit. Losses of anthocyanin pigments, vitamin C, and jellifying power were rather small, and the subsequent changes in flavor were practically non existant. The authors recommend the applicationmore » of moderate doses of gamma -rays (about 0.3 Mrad) to exported bilberries prior to their shipment. (auth)« less

Results on the Performance of a Broad Band Focussing Cherenkov Counter

DOE R&D Accomplishments Database

Cester, R.; Fitch, V. L.; Montag, A.; Sherman, S.; Webb, R. C.; Witherell, M. S.

1980-01-01

The field of ring imaging (broad band differential) Cherenkov detectors has become a very active area of interest in detector development at several high energy physics laboratories. Our group has previously reported on a method of Cherenkov ring imaging for a counter with large momentum and angular acceptance using standard photo multipliers. Recently, we have applied this technique to the design of a set of Cherenkov counters for use in a particle search experiment at Fermi National Accelerator Laboratory (FNAL). This new detector operates over the range 0.998 < ..beta.. < 1.000 in velocity with a delta..beta.. approx. 2 x 10{sup -4}. The acceptance in angle is +- 14 mrad in the horizontal and +- 28 mrad in the vertical. We report here on the performance of this counter.

Symphysis pubis width and unaffected hip joint width in patients with slipped upper femoral epiphysis: widening compared with normal values.

PubMed

Tins, Bernhard; Cassar-Pullicino, Victor; Haddaway, Mike

2010-04-01

The exact pathomechanism of slipped upper femoral epiphysis (SUFE) remains elusive. This paper suggests a generalised abnormality of the development or maturation of cartilage as a possible cause. It is proposed that SUFE is part of a generalised abnormality of the cartilage formation or maturation resulting in abnormal measurements of cartilaginous joint structures. Radiographs of SUFE patients were assessed for the width of the unaffected hip joint and the symphysis pubis. Comparison with previously published normal values was made. Fifty-one patients were assessed, 35 male, 16 female. The average age was 12 years and 11 months combined for both sexes, 13 years 8 months for boys, 11 years 4 months for girls. Width of the symphysis pubis was assessed on 46 datasets, and comparison with normal values was performed using the Wilcoxon paired rank test. Statistical significance was set as p < 0.05. The average expected width was 5.8 mm (5.4-6.2 mm), the average measured width was 7.3 mm (3.5-12 mm), median value 7.0 mm, and the difference is statistically significant. Cartilage thickness of the uninvolved hip joint could be assessed in 46 cases, and comparison using the Wilcoxon paired rank test resulted in a statistically significant difference (significance set as p < 0.05). The average expected width was 4.9 mm (3.6-6.5 mm), the average measured width was 5.5 mm (4-8 mm), and median 5.3 mm. The results indicate that SUFE patients display a generalised increased width of joint cartilage for their age. This could be due to increased cartilage formation or decreased maturation or a combination of the two, and could explain the increased mechanical vulnerability of these children to normal or abnormal stresses, despite histologically normal organisation of the physis as shown in previous studies.

The quantitative measurements of foveal avascular zone using optical coherence tomography angiography in normal volunteers.

PubMed

Ghassemi, Fariba; Mirshahi, Reza; Bazvand, Fatemeh; Fadakar, Kaveh; Faghihi, Houshang; Sabour, Siamak

2017-12-01

To provide normative data of foveal avascular zone (FAZ) and thickness. In this cross-sectional study both eyes of each normal subject were scanned with optical coherence tomography angiography (OCTA) for foveal superficial and deep avascular zone (FAZ) and central foveal thickness (CFT) and parafoveal thickness (PFT). Out of a total of 224 eyes of 112 volunteers with a mean age of 37.03 (12-67) years, the mean superficial FAZ area was 0.27 mm 2 , and deep FAZ area was 0.35 mm 2 ( P  < 0.001), with no difference between both eyes. Females had a larger superficial (0.32 ± 0.11 mm 2 versus 0.23 ± 0.09 mm 2 ) and deep FAZ (0.40 ± 0.14 mm 2 versus 0.31 ± 0.10 mm 2 ) ( P  < 0.001) than males. By multivariate linear regression analysis, in normal eyes, superficial FAZ area varied significantly with the gender, CFT, and deep FAZ. Deep FAZ varied with the gender and CFT. The gender and CFT influence the size of normal superficial and deep FAZ of capillary network.

Effect of high pressurization versus normal pressurization on changes in intraocular pressure immediately after clear corneal cataract surgery.

PubMed

Hayashi, Ken; Yoshida, Motoaki; Manabe, Shin-Ichi; Yoshimura, Koichi

2014-01-01

To compare changes in intraocular pressure (IOP) immediately after clear corneal incision (CCI) cataract surgery between eyes in which IOP was adjusted to a high or normal range at the conclusion of surgery. Hayashi Eye Hospital, Fukuoka, Japan. Comparative case series. Either eye of patients scheduled for phacoemulsification was randomized to 1 of 2 groups as follows: eyes that were to be adjusted to (1) high IOP (22 to 40 mm Hg) or (2) normal IOP (10 to 21 mm Hg). The IOP was measured using a rebound tonometer preoperatively; at the conclusion of surgery; and 15, 30, 60, 120, and 180 minutes and 24 hours postoperatively. The Seidel test and anterior segment optical coherence tomography (AS-OCT) were performed. The mean IOP at the conclusion of surgery was 31.3 mm Hg in the high IOP group and 17.1 mm Hg in the normal IOP group. The IOP decreased to approximately 15 mm Hg by 15 minutes and did not change until 60 minutes in either group. The mean IOP did not differ significantly between groups throughout the observation period (P ≥.0634). Hypotony of 5 mm Hg or less was not detected in any eye. The Seidel test was negative and based on AS-OCT, the wound was closed at 60 minutes in all eyes. After adjusting IOP to a high or normal range, the IOP normalized within 15 minutes postoperatively and was stable for 24 hours. The wound was closed within 60 minutes postoperatively. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Performance study of highly efficient 520 W average power long pulse ceramic Nd:YAG rod laser

NASA Astrophysics Data System (ADS)

Choubey, Ambar; Vishwakarma, S. C.; Ali, Sabir; Jain, R. K.; Upadhyaya, B. N.; Oak, S. M.

2013-10-01

We report the performance study of a 2% atomic doped ceramic Nd:YAG rod for long pulse laser operation in the millisecond regime with pulse duration in the range of 0.5-20 ms. A maximum average output power of 520 W with 180 J maximum pulse energy has been achieved with a slope efficiency of 5.4% using a dual rod configuration, which is the highest for typical lamp pumped ceramic Nd:YAG lasers. The laser output characteristics of the ceramic Nd:YAG rod were revealed to be nearly equivalent or superior to those of high-quality single crystal Nd:YAG rod. The laser pump chamber and resonator were designed and optimized to achieve a high efficiency and good beam quality with a beam parameter product of 16 mm mrad (M2˜47). The laser output beam was efficiently coupled through a 400 μm core diameter optical fiber with 90% overall transmission efficiency. This ceramic Nd:YAG laser will be useful for various material processing applications in industry.

A GEM readout with radial zigzag strips and linear charge-sharing response

DOE PAGES

Zhang, Aiwu; Hohlmann, Marcus; Azmoun, Babak; ...

2018-01-10

Here, we study the position sensitivity of radial zigzag strips intended to read out large GEM detectors for tracking at future experiments. Zigzag strips can cover a readout area with fewer strips than regular straight strips while maintaining good spatial resolution. Consequently, they can reduce the number of required electronic channels and related cost for large-area GEM detector systems. A non-linear relation between incident particle position and hit position measured from charge sharing among zigzag strips was observed in a previous study. We significantly reduce this non-linearity by improving the interleaving of adjacent physical zigzag strips. Zigzag readout structures aremore » implemented on PCBs and on a flexible foil and are tested using a 10 cm × 10 cm triple-GEM detector scanned with a strongly collimated X-ray gun on a 2D motorized stage. Lastly, angular resolutions of 60–84 μrad are achieved with a 1.37 mrad angular strip pitch at a radius of 784 mm. On a linear scale this corresponds to resolutions below 100 μm.« less

Experimental investigation of a diode-pumped powerful continuous-wave dual-wavelength Nd:YAG laser at 946 and 938.6 nm

NASA Astrophysics Data System (ADS)

Chen, F.; Yu, X.; Yan, R. P.; Li, X. D.; Li, D. J.; Yang, G. L.; Xie, J. J.; Guo, J.

2013-05-01

In this paper, a diode-pumped high-power continuous-wave (cw) dual-wavelength Nd:YAG laser at 946 and 938.6 nm is reported. By using an end-pumped structure, comparative experiments indicate that a 5 mm-length Nd:YAG crystal with a Nd3+-doping concentration of 0.3 at.% is favorable for high-power laser operation, and the optimal transmissivity of the output coupler is 9%. As a result, a maximum output power of 17.2 W for a dual-wavelength laser at 946 and 938.6 nm is obtained at an incident pump power of 75.9 W, corresponding to a slope efficiency of 26.5%. To the best of our knowledge, this is the highest output power of a quasi-three-level dual-wavelength laser using a conventional Nd:YAG crystal achieved to date. By using a traveling knife-edge method, the beam quality factor and far-field divergence angle at 17 W power level are estimated to be 4.0 and 6.13 mrad, respectively.

A GEM readout with radial zigzag strips and linear charge-sharing response

NASA Astrophysics Data System (ADS)

Zhang, Aiwu; Hohlmann, Marcus; Azmoun, Babak; Purschke, Martin L.; Woody, Craig

2018-04-01

We study the position sensitivity of radial zigzag strips intended to read out large GEM detectors for tracking at future experiments. Zigzag strips can cover a readout area with fewer strips than regular straight strips while maintaining good spatial resolution. Consequently, they can reduce the number of required electronic channels and related cost for large-area GEM detector systems. A non-linear relation between incident particle position and hit position measured from charge sharing among zigzag strips was observed in a previous study. We significantly reduce this non-linearity by improving the interleaving of adjacent physical zigzag strips. Zigzag readout structures are implemented on PCBs and on a flexible foil and are tested using a 10 cm × 10 cm triple-GEM detector scanned with a strongly collimated X-ray gun on a 2D motorized stage. Angular resolutions of 60-84 μrad are achieved with a 1.37 mrad angular strip pitch at a radius of 784 mm. On a linear scale this corresponds to resolutions below 100 μm.

Beam position reconstruction for the g2p experiment in Hall A at Jefferson Lab

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Pengjia; Allada, Kalyan; Allison, Trent

2015-11-03

Beam-line equipment was upgraded for experiment E08-027 (g2p) in Hall A at Jefferson Lab. Two beam position monitors (BPMs) were necessary to measure the beam position and angle at the target. A new BPM receiver was designed and built to handle the low beam currents (50-100 nA) used for this experiment. Two new super-harps were installed for calibrating the BPMs. In addition to the existing fast raster system, a slow raster system was installed. We found that before and during the experiment, these new devices were tested and debugged, and their performance was also evaluated. In order to achieve themore » required accuracy (1-2 mm in position and 1-2 mrad in angle at the target location), the data of the BPMs and harps were carefully analyzed, as well as reconstructing the beam position and angle event by event at the target location. Finally, the calculated beam position will be used in the data analysis to accurately determine the kinematics for each event.« less

An all permanent magnet electron cyclotron resonance ion source for heavy ion therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cao, Yun, E-mail: caoyun@impcas.ac.cn; Li, Jia Qing; Sun, Liang Ting

2014-02-15

A high charge state all permanent Electron Cyclotron Resonance ion source, Lanzhou All Permanent ECR ion source no. 3-LAPECR3, has been successfully built at IMP in 2012, which will serve as the ion injector of the Heavy Ion Medical Machine (HIMM) project. As a commercial device, LAPECR3 features a compact structure, small size, and low cost. According to HIMM scenario more than 100 eμA of C{sup 5+} ion beam should be extracted from the ion source, and the beam emittance better than 75 π*mm*mrad. In recent commissioning, about 120 eμA of C{sup 5+} ion beam was got when work gasmore » was CH{sub 4} while about 262 eμA of C{sup 5+} ion beam was obtained when work gas was C{sub 2}H{sub 2} gas. The design and construction of the ion source and its low-energy transportation beam line, and the preliminary commissioning results will be presented in detail in this paper.« less

Advancements in high-power high-brightness laser bars and single emitters for pumping and direct diode application

NASA Astrophysics Data System (ADS)

An, Haiyan; Jiang, Ching-Long J.; Xiong, Yihan; Zhang, Qiang; Inyang, Aloysius; Felder, Jason; Lewin, Alexander; Roff, Robert; Heinemann, Stefan; Schmidt, Berthold; Treusch, Georg

2015-03-01

We have continuously optimized high fill factor bar and packaging design to increase power and efficiency for thin disc laser system pump application. On the other hand, low fill factor bars packaged on the same direct copper bonded (DCB) cooling platform are used to build multi-kilowatt direct diode laser systems. We have also optimized the single emitter designs for fiber laser pump applications. In this paper, we will give an overview of our recent advances in high power high brightness laser bars and single emitters for pumping and direct diode application. We will present 300W bar development results for our next generation thin disk laser pump source. We will also show recent improvements on slow axis beam quality of low fill factor bar and its application on performance improvement of 4-5 kW TruDiode laser system with BPP of 30 mm*mrad from a 600 μm fiber. Performance and reliability results of single emitter for multiemitter fiber laser pump source will be presented as well.

Near- and Extended-Edge X-Ray-Absorption Fine-Structure Spectroscopy Using Ultrafast Coherent High-Order Harmonic Supercontinua

NASA Astrophysics Data System (ADS)

Popmintchev, Dimitar; Galloway, Benjamin R.; Chen, Ming-Chang; Dollar, Franklin; Mancuso, Christopher A.; Hankla, Amelia; Miaja-Avila, Luis; O'Neil, Galen; Shaw, Justin M.; Fan, Guangyu; Ališauskas, Skirmantas; Andriukaitis, Giedrius; Balčiunas, Tadas; Mücke, Oliver D.; Pugzlys, Audrius; Baltuška, Andrius; Kapteyn, Henry C.; Popmintchev, Tenio; Murnane, Margaret M.

2018-03-01

Recent advances in high-order harmonic generation have made it possible to use a tabletop-scale setup to produce spatially and temporally coherent beams of light with bandwidth spanning 12 octaves, from the ultraviolet up to x-ray photon energies >1.6 keV . Here we demonstrate the use of this light for x-ray-absorption spectroscopy at the K - and L -absorption edges of solids at photon energies near 1 keV. We also report x-ray-absorption spectroscopy in the water window spectral region (284-543 eV) using a high flux high-order harmonic generation x-ray supercontinuum with 109 photons/s in 1% bandwidth, 3 orders of magnitude larger than has previously been possible using tabletop sources. Since this x-ray radiation emerges as a single attosecond-to-femtosecond pulse with peak brightness exceeding 1026 photons/s /mrad2/mm2/1 % bandwidth, these novel coherent x-ray sources are ideal for probing the fastest molecular and materials processes on femtosecond-to-attosecond time scales and picometer length scales.

Structural biology at the European X-ray free-electron laser facility.

PubMed

Altarelli, Massimo; Mancuso, Adrian P

2014-07-17

The European X-ray free-electron laser (XFEL) facility, under construction in the Hamburg region, will provide high-peak brilliance (greater than 10(33) photons s(-1) mm(-2) mrad(-2) per 0.1% BW), ultrashort pulses (approx. 10 fs) of X-rays, with a high repetition rate (up to 27 000 pulses s(-1)) from 2016 onwards. The main features of this exceptional X-ray source, and the instrumentation developments necessary to exploit them fully, for application to a variety of scientific disciplines, are briefly summarized. In the case of structural biology, that has a central role in the scientific case of this new facility, the instruments and ancillary laboratories that are being planned and built within the baseline programme of the European XFEL and by consortia of users are also discussed. It is expected that the unique features of the source and the advanced features of the instrumentation will allow operation modes with more efficient use of sample materials, faster acquisition times, and conditions better approaching feasibility of single molecule imaging. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Channeling Radiation Experiment at Fermilab ASTA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mihalcea, D.; Edstrom, D. R.; Piot, P.

2015-06-01

Electron beams with moderate energy ranging from 4 to 50 MeV can be used to produce x-rays through the Channeling Radiation (CR) mechanism. Typically, the xray spectrum from these sources extends up to 140 keV and this range covers the demand for most practical applications. The parameters of the electron beam determine the spectral brilliance of the x-ray source. The electron beam produced at the Fermilab new facility Advanced Superconducting Test Accelerator (ASTA) meets the requirements to assemble an experimental high brilliance CR xray source. In the first stage of the experiment the energy of the beam is 20 MeV and due to the very low emittance (more » $$\\approx 100$$ nm ) at low bunch charge (20 pC) the expected average brilliance of the x-ray source is about $10^9$ photons/[s- $(mm-mrad)^2$-0.1% BW]. In the second stage of the experiment the beam energy will be increased to 50 MeV and consequently the average brilliance will increase by a factor of five. Also, the x-ray spectrum will extend from about 30 keV to 140 keV« less

Generation of bright attosecond x-ray pulse trains via Thomson scattering from laser-plasma accelerators.

PubMed

Luo, W; Yu, T P; Chen, M; Song, Y M; Zhu, Z C; Ma, Y Y; Zhuo, H B

2014-12-29

Generation of attosecond x-ray pulse attracts more and more attention within the advanced light source user community due to its potentially wide applications. Here we propose an all-optical scheme to generate bright, attosecond hard x-ray pulse trains by Thomson backscattering of similarly structured electron beams produced in a vacuum channel by a tightly focused laser pulse. Design parameters for a proof-of-concept experiment are presented and demonstrated by using a particle-in-cell code and a four-dimensional laser-Compton scattering simulation code to model both the laser-based electron acceleration and Thomson scattering processes. Trains of 200 attosecond duration hard x-ray pulses holding stable longitudinal spacing with photon energies approaching 50 keV and maximum achievable peak brightness up to 10²⁰ photons/s/mm²/mrad²/0.1%BW for each micro-bunch are observed. The suggested physical scheme for attosecond x-ray pulse trains generation may directly access the fastest time scales relevant to electron dynamics in atoms, molecules and materials.

Orbital cerebrospinal fluid space in glaucoma: the Beijing intracranial and intraocular pressure (iCOP) study.

PubMed

Wang, Ningli; Xie, Xiaobin; Yang, Diya; Xian, Junfang; Li, Yong; Ren, Ruojin; Peng, Xiaoxia; Jonas, Jost B; Weinreb, Robert N

2012-10-01

Low cerebrospinal fluid pressure (CSF-P) may be involved in the pathogenesis of glaucoma. We measured the optic nerve subarachnoid space width (ONSASW) as a surrogate for orbital CSF-P in patients with primary open-angle glaucoma (POAG) with normal and high pressure and a control group. Prospective observational study. The study included 39 patients with POAG; 21 patients had normal pressure (intraocular pressure [IOP] 21 mmHg), and 18 patients had high pressure (IOP >21 mmHg); 21 subjects formed the control group. By using magnetic resonance imaging (MRI) with fat-suppressed fast recovery fast spin echo (FRFSE) T2-weighted sequence, we determined the ONSASW at 3, 9, and 15 mm posterior to the globe. The ONSASW and optic nerve diameter. At all 3 measurement locations of 3, 9, and 15 mm, the ONSASW was significantly (P<0.001, P<0.001, and P = 0.003, respectively) narrower in the normal-pressure group (0.67±0.16, 0.55±0.09, and 0.51±0.12 mm, respectively) than in the high-pressure group (0.93±0.21, 0.70±0.12, and 0.62±0.11 mm, respectively) or the control group (0.87±0.15, 0.67±0.07, and 0.61±0.07 mm, respectively). The high-pressure and control groups did not vary significantly at 3, 9, and 15 mm (P = 0.31, P = 0.39, and P = 0.44, respectively). At all 3 measurement locations, ONSASW was narrower in the normal-pressure group compared with the high-pressure and control groups after adjustment for optic nerve diameter (P<0.01). Correspondingly, the width of the optic nerve subarachnoid space measured at 3, 9, and 15 mm behind the globe, respectively, was significantly (all P<0.05) associated with IOP after adjustment for optic nerve diameter and visual field defect. The narrower orbital optic nerve subarachnoid space in patients with POAG with normal pressure compared with high pressure suggests a lower orbital CSF-P in patients with POAG with normal pressure. Copyright © 2012 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Endometrial thickness affects the outcome of in vitro fertilization and embryo transfer in normal responders after GnRH antagonist administration.

PubMed

Wu, Yu; Gao, Xiaohong; Lu, Xiang; Xi, Ji; Jiang, Shan; Sun, Yin; Xi, Xiaowei

2014-10-09

The goal of this study was to assess the association between endometrial thickness on the chorionic gonadotropin (hCG) day and in vitro fertilization and embryo transfer (IVF-ET) outcome in normal responders after GnRH antagonist administration. A retrospective cohort study was performed in normal responders with GnRH antagonist administration from January 2011-December 2013. Patients were divided into four groups according to endometrial thickness, as follows: <7 mm (group 1), > = 7- < 8 mm (group 2), > = 8- < 14 mm (group 3), and > =14 mm (group 4). A total of 2106 embryo transfer cycles were analyzed. The pregnancy rate (PR) was 44.87%.The clinical pregnancy rate, ongoing pregnancy rate and the implantation rate (17.28%, 13.79%, 10.17%, respectively) were significantly lower in group 1 compared to the other three groups (p < 0.05). The miscarriage rate was higher in patients with endometrial thickness less than 7 mm. The clinical pregnancy rate, ongoing pregnancy rate and implantation rate were highest in patients with endometrial thickness higher than 14 mm, but showed no difference in patients with those of endometrial thickness between 8-14 mm. There is a correlation between endometrial thickness measured on hCG day and clinical outcome in normal responders with GnRH antagonist administration. The pregnancy rate was lower in patients with endometrial thickness less than 7 mm compared with patients with endometrial thickness more than 7 mm.

A new treatment for human malignant melanoma targeting L-type amino acid transporter 1 (LAT1): A pilot study in a canine model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fukumoto, Shinya; Hanazono, Kiwamu; Fu, Dah-Renn

2013-09-13

Highlights: •LAT1 is highly expressed in tumors but at low levels in normal tissues. •We examine LAT1 expression and function in malignant melanoma (MM). •LAT1 expression in MM tissues and cell lines is higher than those in normal tissues. •LAT1 selective inhibitors inhibit amino acid uptake and cell growth in MM cells. •New chemotherapeutic protocols including LAT1 inhibitors are effective for treatment. -- Abstract: L-type amino acid transporter 1 (LAT1), an isoform of amino acid transport system L, transports branched or aromatic amino acids essential for fundamental cellular activities such as cellular growth, proliferation and maintenance. This amino acid transportermore » recently has received attention because of its preferential and up-regulated expression in a variety of human tumors in contrast to its limited distribution and low-level expression in normal tissues. In this study, we explored the feasibility of using LAT1 inhibitor as a new therapeutic agent for human malignant melanomas (MM) using canine spontaneous MM as a model for human MM. A comparative study of LAT expression was performed in 48 normal tissues, 25 MM tissues and five cell lines established from MM. The study observed LAT1 mRNA levels from MM tissues and cell lines that were significantly (P < 0.01) higher than in normal tissues. Additionally, MM with distant metastasis showed a higher expression than those without distant metastasis. Functional analysis of LAT1 was performed on one of the five cell lines, CMeC-1. [{sup 3}H]L-Leucine uptake and cellular growth activities in CMeC-1 were inhibited in a dose-dependent manner by selective LAT1 inhibitors (2-amino-2-norbornane-carboxylic acid, BCH and melphalan, LPM). Inhibitory growth activities of various conventional anti-cancer drugs, including carboplatin, cyclophosphamide, dacarbazine, doxorubicin, mitoxantrone, nimustine, vinblastine and vincristine, were significantly (P < 0.05) enhanced by combination use with BCH or LPM. These findings suggest that LAT1 could be a new therapeutic target for MM.« less

ChemCam Targeted Science at Gale Crater

NASA Astrophysics Data System (ADS)

Wiens, R. C.; Blaney, D. L.; Clark, B. C.; Bridges, N. T.; Clegg, S. M.; Maurice, S.; Newsom, H. E.; Vaniman, D. T.; Herkenhoff, K. E.; Ollila, A. M.; Gasnault, O.; Pinet, P. C.; Dromart, G.; Barraclough, B. L.; Lasue, J.

2011-12-01

The MSL rover, Curiosity, uses a novel remote-sensing instrument, ChemCam, which combines laser-induced breakdown spectroscopy (LIBS) with a high resolution remote micro-imager (RMI). ChemCam uses a focused, pulsed laser beam at targets up to 7 m away to excite a light-emitting plasma. Spectral analysis identifies elements present and provides rapid semi-quantitative analyses. Repeated laser pulses remove dust and weathering coatings from rock samples to depths >0.5 mm and ~0.4 mm in diameter. The RMI, with ~20x20 mrad field of view, provides a broad-band image with 100 μm resolution. LIBS yields abundances of H, Li, Be, B, C, N, O, F, Na, Mg, Al, Si, P, Cl, K, Ca, Ti, V, Cr, Fe, Ni, Zr, Rb, Sr, As, Ba, and Pb. Interference from atmospheric constituents raises the detection limits of C, N, and O (e.g., >2% wt for C). LIBS is very sensitive to alkali and alkali earth elements, with some detection limits to ~1 ppm at close range. Conversely, LIBS is insensitive to F, Cl, S, P, and N, with detection limits of several wt. %. Pointing accuracy is ~3 mrad, however relative pointing accuracy is better, so line scans and rasters will enable analyses of targeted features to ~1 mm. At Gale Crater, determination of elements not previously analyzed in-situ, i.e., H, Li, Rb, Sr, and Ba, along with other elements will constrain aqueous, hydrothermal and vapor geochemical transport processes. Initial analyses after landing will characterize air fall dust and weathering coatings on local rocks, and profile the soil and surfacial materials including bedforms to investigate compositional differences in near-surface layers. Targets within the landing ellipse include fan and inverted channel deposits derived from the crater rim, which may contain alteration minerals produced by impact hydrothermal processes. Enigmatic deposits with bright fracture fill could represent lake sediments modified by injection of deposits from groundwater. During the drive to the Gale mound, ChemCam will provide daily assays of soil composition and morphology, looking for changes en route. A scarp defining the boundary between low and high thermal inertia regions in the ellipse will be another target. Small craters may expose the stratigraphy of the fan. Near the mound ChemCam will study the transition from the fan to the basal unit of the mound to determine whether it contains lithified bedforms. What is the cementing material and what can we learn about the temperature history or depth of burial? At the mound, ChemCam will study chemostratigraphy, correlating elemental compositions against textural fabrics and cross-bedding geometries, and assessing the petrographic heterogeneity of sedimentary and/or diagenetic grains. ChemCam will also investigate questions such as: What are the hydration states of phyllosilicates and salts, including diurnal variability? What fraction of the material is phyllosilicates and how are they distributed? What characterizes the transition from phyllosilicates to sulfates? ChemCam will play a key role in unraveling the geologic history recorded in Gale Crater.

Picture of Ganymede

NASA Technical Reports Server (NTRS)

Gehrels, T.

1977-01-01

Spin-scan images of Ganymede obtained by the imaging photopolarimeter of Pioneer 10 in December 1973 are described and presented. Intensity measurements in the blue and red scans are provided. The width of the scan elements is 0.5 mrad which is the size of the aperture in the focal plane of the telescope; the height is also 0.5 mrad (1 millisec integration - or dwell-time at 5 rpm spin rate). The distance of Pioneer 10 from Ganymede was 7.8 x 10 to the fifth km, and the resolution is therefore 390 km. The spin-scan image is in general agreement with Lyot's visual observations (Dollfus, 1961). Preliminary results on polarimetry of Ganymede obtained during the flyby of Pioneer 10 are discussed with attention to the question of whether water frost, NaCl powdered crystals, or other substances is responsible for the observed pattern.

Assessing Pharmacy Students’ Ability to Accurately Measure Blood Pressure Using a Blood Pressure Simulator Arm

PubMed Central

Bryant, Ginelle A.; Haack, Sally L.; North, Andrew M.

2013-01-01

Objective. To compare student accuracy in measuring normal and high blood pressures using a simulator arm. Methods. In this prospective, single-blind, study involving third-year pharmacy students, simulator arms were programmed with prespecified normal and high blood pressures. Students measured preset normal and high diastolic and systolic blood pressure using a crossover design. Results. One hundred sixteen students completed both blood pressure measurements. There was a significant difference between the accuracy of high systolic blood pressure (HSBP) measurement and normal systolic blood pressure (NSBP) measurement (mean HSBP difference 8.4 ± 10.9 mmHg vs NSBP 3.6 ± 6.4 mmHg; p<0.001). However, there was no difference between the accuracy of high diastolic blood pressure (HDBP) measurement and normal diastolic blood pressure (NDBP) measurement (mean HDBP difference 6.8 ± 9.6 mmHg vs. mean NDBP difference 4.6 ± 4.5 mmHg; p=0.089). Conclusions. Pharmacy students may need additional instruction and experience with taking high blood pressure measurements to ensure they are able to accurately assess this important vital sign. PMID:23788809

Assessing pharmacy students' ability to accurately measure blood pressure using a blood pressure simulator arm.

PubMed

Bottenberg, Michelle M; Bryant, Ginelle A; Haack, Sally L; North, Andrew M

2013-06-12

To compare student accuracy in measuring normal and high blood pressures using a simulator arm. In this prospective, single-blind, study involving third-year pharmacy students, simulator arms were programmed with prespecified normal and high blood pressures. Students measured preset normal and high diastolic and systolic blood pressure using a crossover design. One hundred sixteen students completed both blood pressure measurements. There was a significant difference between the accuracy of high systolic blood pressure (HSBP) measurement and normal systolic blood pressure (NSBP) measurement (mean HSBP difference 8.4 ± 10.9 mmHg vs NSBP 3.6 ± 6.4 mmHg; p<0.001). However, there was no difference between the accuracy of high diastolic blood pressure (HDBP) measurement and normal diastolic blood pressure (NDBP) measurement (mean HDBP difference 6.8 ± 9.6 mmHg vs. mean NDBP difference 4.6 ± 4.5 mmHg; p=0.089). Pharmacy students may need additional instruction and experience with taking high blood pressure measurements to ensure they are able to accurately assess this important vital sign.

Design of a space-based infrared imaging interferometer

NASA Astrophysics Data System (ADS)

Hart, Michael; Hope, Douglas; Romeo, Robert

2017-07-01

Present space-based optical imaging sensors are expensive. Launch costs are dictated by weight and size, and system design must take into account the low fault tolerance of a system that cannot be readily accessed once deployed. We describe the design and first prototype of the space-based infrared imaging interferometer (SIRII) that aims to mitigate several aspects of the cost challenge. SIRII is a six-element Fizeau interferometer intended to operate in the short-wave and midwave IR spectral regions over a 6×6 mrad field of view. The volume is smaller by a factor of three than a filled-aperture telescope with equivalent resolving power. The structure and primary optics are fabricated from light-weight space-qualified carbon fiber reinforced polymer; they are easy to replicate and inexpensive. The design is intended to permit one-time alignment during assembly, with no need for further adjustment once on orbit. A three-element prototype of the SIRII imager has been constructed with a unit telescope primary mirror diameter of 165 mm and edge-to-edge baseline of 540 mm. The optics, structure, and interferometric signal processing principles draw on experience developed in ground-based astronomical applications designed to yield the highest sensitivity and resolution with cost-effective optical solutions. The initial motivation for the development of SIRII was the long-term collection of technical intelligence from geosynchronous orbit, but the scalable nature of the design will likely make it suitable for a range of IR imaging scenarios.

Novel beam delivery fibers for delivering flat-top beams with controlled BPP for high power CW and pulsed laser applications

NASA Astrophysics Data System (ADS)

Jollivet, C.; Farley, K.; Conroy, M.; Abramczyk, J.; Belke, S.; Becker, F.; Tankala, K.

2016-03-01

Single-mode (SM) kW-class fiber lasers are the tools of choice for material processing applications such as sheet metal cutting and welding. However, application requirements include a flat-top intensity profile and specific beam parameter product (BPP). Here, Nufern introduces a novel specialty fiber technology capable of converting a SM laser beam into a flat-top beam suited for these applications. The performances are demonstrated using a specialty fiber with 100 μm pure silica core, 0.22 NA surrounded by a 120 μm fluorine-doped layer and a 360 μm pure silica cladding, which was designed to match the conventional beam delivery fibers. A SM fiber laser operating at a wavelength of 1.07 μm and terminated with a large-mode area (LMA) fiber with 20 μm core and 0.06 NA was directly coupled in the core of the flat-top specialty fiber using conventional splicing technique. The output beam profile and BPP were characterized first with a low-power source and confirmed using a 2 kW laser and we report a beam transformation from a SM beam into a flat-top intensity profile beam with a 3.8 mm*mrad BPP. This is, to the best of our knowledge, the first successful beam transformation from SM to MM flat-top with controlled BPP in a single fiber integrated in a multi-kW all-fiber system architecture.

Four-Dimensional CT of the Diaphragm in Children: Initial Experience

PubMed Central

2018-01-01

Objective To evaluate the technical feasibility of four-dimensional (4D) CT for the functional evaluation of the pediatric diaphragm. Materials and Methods In 22 consecutive children (median age 3.5 months, age range 3 days–3 years), 4D CT was performed to assess diaphragm motion. Diaphragm abnormalities were qualitatively evaluated and diaphragm motion was quantitatively measured on 4D CT. Lung density changes between peak inspiration and expiration were measured in the basal lung parenchyma. The diaphragm motions and lung density changes measured on 4D CT were compared between various diaphragm conditions. In 11 of the 22 children, chest sonography was available for comparison. Results Four-dimensional CT demonstrated normal diaphragm (n = 8), paralysis (n = 10), eventration (n = 3), and diffusely decreased motion (n = 1). Chest sonography demonstrated normal diaphragm (n = 2), paralysis (n = 6), eventration (n = 2), and right pleural effusion (n = 1). The sonographic findings were concordant with the 4D CT findings in 90.9% (10/11) of the patients. In diaphragm paralysis, the affected diaphragm motion was significantly decreased compared with the contralateral normal diaphragm motion (−1.1 ± 2.2 mm vs. 7.6 ± 3.8 mm, p = 0.005). The normal diaphragms showed significantly greater motion than the paralyzed diaphragms (4.5 ± 2.1 mm vs. −1.1 ± 2.2 mm, p < 0.0001), while the normal diaphragm motion was significantly smaller than the motion of the contralateral normal diaphragm in paralysis (4.5 ± 2.1 mm vs. 7.6 ± 3.8 mm, p = 0.01). Basal lung density change of the affected side was significantly smaller than that of the contralateral side in diaphragm paralysis (89 ± 73 Hounsfield units [HU] vs. 180 ± 71 HU, p = 0.03), while no significant differences were found between the normal diaphragms and the paralyzed diaphragms (136 ± 66 HU vs. 89 ± 73 HU, p = 0.1) or between the normal diaphragms and the contralateral normal diaphragms in paralysis (136 ± 66 HU vs. 180 ± 71 HU, p = 0.1). Conclusion The functional evaluation of the pediatric diaphragm is feasible with 4D CT in select children. PMID:29354007

Impact of Altered Precipitation Patterns on Plant Productivity and Soil Respiration in a Northern Great Plains Grassland

NASA Astrophysics Data System (ADS)

Haase, L.; Flanagan, L. B.

2017-12-01

Precipitation patterns are expected to shift towards larger but fewer rain events, with longer intermittent dry periods, associated with climate change. The larger rain events may compensate for and help to mitigate climate change effects on key ecosystem functions such as plant productivity and soil respiration in semi-arid grasslands. We experimentally manipulated the amount and frequency of simulated precipitation added to trenched, treatment plots that were covered by rain shelters, and measured the response in plant productivity and soil respiration in a native, grassland ecosystem near Lethbridge, Alberta. We compared the observed responses to the predictions of a conceptual ecosystem response model developed by Knapp et al. 2008 (BioScience 58: 811-821). Two experiments were conducted during 14 weeks of the growing season from May-August. The first experiment (normal amount) applied total growing season precipitation of 180 mm (climate normal), and the second experiment (reduced amount) applied total precipitation of 90 mm. In both experiments, precipitation was applied at two frequencies, 1 rain event every week (normal frequency) and 1 rain event every two weeks (reduced frequency). In the normal amount experiment, the average rain event was 12.8 mm for the normal frequency treatment and 25.8 mm for the reduced frequency treatment. In the reduced amount experiment, the average rain event was 6.4 mm for the normal frequency treatment and 12.8 mm for the reduced frequency treatment. We hypothesized that larger but fewer rain events would result in increased plant productivity and soil respiration for both experiments. Plant greenness values calculated from digital photographs were used as a proxy for plant productivity, and showed significantly higher values for the normal vs. reduced amount experiment. Soil respiration rate also showed significantly higher values for the normal vs. reduced amount experiment. No significant treatment effect could be detected between the normal vs. reduced frequency treatments in both experiments for either the plant greenness or soil respiration measurements. The results of this study have implications for understanding the mechanisms underlying ecosystem responses to anticipated precipitation change in the Great Plains.

Building block diode laser concept for high brightness laser output in the kW range and its applications

NASA Astrophysics Data System (ADS)

Ferrario, Fabio; Fritsche, Haro; Grohe, Andreas; Hagen, Thomas; Kern, Holger; Koch, Ralf; Kruschke, Bastian; Reich, Axel; Sanftleben, Dennis; Steger, Ronny; Wallendorf, Till; Gries, Wolfgang

2016-03-01

The modular concept of DirectPhotonics laser systems is a big advantage regarding its manufacturability, serviceability as well as reproducibility. By sticking to identical base components an economic production allows to serve as many applications as possible while keeping the product variations minimal. The modular laser design is based on single emitters and various combining technics. In a first step we accept a reduction of the very high brightness of the single emitters by vertical stacking several diodes in fast axis. This can be theoretically done until the combined fast axis beam quality is on a comparable level as the individual diodes slow axis beam quality without loosing overall beam performance after fiber coupling. Those stacked individual emitters can be wavelength stabilized by an external resonator, providing the very same feedback to each of those laser diodes which leads to an output power of about 100 W with BPP of <3.5 mm*mrad (FA) and <5 mm*mrad (SA). In the next steps, further power scaling is accomplished by polarization and wavelength multiplexing yielding high optical efficiencies of more than 80% and resulting in a building block module with about 500 W launched into a 100 μm fiber with 0.15 NA. Higher power levels can be achieved by stacking those building blocks using the very same dense spectral combing technique up to multi kW Systems without further reduction of the BPP. The 500 W building blocks are consequently designed in a way that they feature a high flexibility with regard to their emitting wavelength bandwidth. Therefore, new wavelengths can be implemented by only exchanging parts and without any additional change of the production process. This design principal theoretically offers the option to adapt the wavelength of those blocks to any applications, from UV, visible into the far IR as long as there are any diodes commercially available. This opens numerous additional applications like laser pumping, scientific applications, materials processing such as cutting and welding of copper aluminum or steel and also medical application. Typical operating at wavelengths in the 9XX nm range, these systems are designed for and mainly used in cutting and welding applications, but adapted wavelength ranges such as 793 nm and 1530 nm are also offered. Around 15XX nm the diodes are already successfully used for resonant pumping of Erbium lasers [1]. Furthermore, the fully integrated electronic concept allows addressing further applications, as due to short lead lengths it is capable of generating very short μs pulses up to cw mode operation by simple software commands.

Risk of Progression to Hypertension in a Low-Income Mexican Population with Pre-hypertension and Normal Blood Pressure

PubMed Central

Jimenez-Corona, Aida; Lopez-Ridaura, Ruy; Stern, Michael P; Gonzalez-Villalpando, Clicerio

2007-01-01

BACKGROUND Blood pressure (BP) levels below the pre-hypertension category may be associated with the risk of developing hypertension. We estimated the incidence rates of hypertension in low-income Mexican population according to several subcategories of baseline BP within normal and pre-hypertension categories. METHODS A total of 1572 nonhypertensive men (n=632) and non-pregnant women (n=940), aged 35 to 64 years at baseline, were followed for a median of 5.8 years. Hypertension was defined as systolic blood pressure (SBP) ≥140 mm Hg, diastolic blood pressure (DBP) ≥90 mm Hg, or self-reported physician diagnosis with anti-hypertensive medications. RESULTS During follow-up, 267 subjects developed hypertension, of whom 83 were men and 184 were women. Age-adjusted incidence rate was higher in women (37.1 per 1000 person-years) than in men (23.7 per 1000 person-years). There was a significant association between BP levels at baseline and hypertension incidence even within the normal category. For the upper levels of normal SBP (110-119 mm Hg), the HR (95%CI) was 2.43 (1.50-3.93) in women and 2.44 (1.05-5.69) in men, compared with SBP <110 mm Hg. For the upper levels of normal DBP (70-79 mm Hg), the HR (95%CI) was 2.33 (1.65-3.31) in women and 1.80 (0.92-3.52) in men, compared with DBP <70 mm Hg, after adjustment for recognized predictors. CONCLUSIONS High risk of hypertension incidence was associated with levels of BP even within the normal category. This information could help define a population at high risk of progression to hypertension, in order to establish preventive measures. PMID:17765131

Design and development of the 6-18 MeV electron beam system for medical and other applications

NASA Astrophysics Data System (ADS)

Shahzad, A.; Phatangare, A. B.; Bharud, V. D.; Bhadane, M. S.; Tahakik, C. D.; Patil, B. J.; Dahiwale, S. S.; Chavan, S. T.; Pethe, S. N.; Dhole, S. D.; Bhoraskar, V. N.

2017-12-01

A system for the electron and photon therapy has been designed and developed at SAMEER, IITB, Mumbai. All the components of the system such as the 270° beam bending electromagnet, trim coils, magnet chamber, electron scattering foil, slits, applicators, etc., were designed and fabricated indigenously. The electrons of 6, 8, 9, 12, 15 and 18 MeV energies were provided by a linear accelerator, indigenously designed and made at SAMEER, IITB campus, Mumbai. The electron beam from the LINAC enters the magnet chamber horizontally, and after deflection and focusing in the 270° bending magnet, comes out of the exit port, and travels a straight path vertically down. After passing through the beryllium and tantalum scattering foils, the electron beam gets scattered and turns into a solid cone shape such that the diameter increases with the travel distance. The simulation results indicate that at the exit port of the 270° beam bending magnet, the electron beam has a divergence angle of ≤ 3 mrad and diameter ∼2-3 mm, and remains constant over 6-18 MeV. Normally, 6-18 MeV electrons are used for the electron therapy of skin and malignant cancer near the skin surface. On a plane at a distance of 100 cm from the scattering foils, the size of the electron beam could be varied from 10 cm × 10 cm to 25 cm × 25 cm using suitable applicators and slits. Different types of applicators were therefore designed and fabricated to provide required beam profile and dose of electrons to a patient. The 6 MeV cyclic electron accelerator called Race-Track Microtron of S. P. Pune University, Pune, was extensively used for studying the performances of the scattering foils, electron beam uniformity and radiation dose measurement. Different types of thermoluminescent dosimetry dosimeters were developed to measure dose in the range of 1-10kGy.

Combined thickness of the uterus and placenta and ultrasonographic examinations of uteroplacental tissues in normal pregnancy, placentitis, and abnormal parturitions in heavy draft horses.

PubMed

Kimura, Yuki; Haneda, Shingo; Aoki, Takahiro; Furuoka, Hidefumi; Miki, Wataru; Fukumoto, Natsuko; Matsui, Motozumi; Nambo, Yasuo

2018-01-01

The combined thickness of the uterus and placenta (CTUP) and ultrasonographic images of uteroplacental tissues were investigated in 35 pregnant heavy draft horses in Months 7-12 of pregnancy. The mares were divided into three groups: those pathologically diagnosed as placentitis (placentitis group, n=3); those who had abortion, premature birth, or fetal malformation (abnormal group, n=7); and those who had no abnormal findings (normal group, n=25). In the normal group, CTUP increased as pregnancy progressed from Months 7 (median, 7.08 mm; range, 5.68-11.27) to 12 (13.31 mm; 7.44-16.31 mm) (P<0.05) and was higher than those reported previously in Thoroughbred, quarter, and American paint horses. Values of CTUP greater than the 75th percentile of the normal group from Months 7 (7.54 mm) to 12 (15.19 mm) were detected in 100% of the placentitis group (3/3) and in 86% of the abnormal group (6/7). Ultrasonographic images showing placental separation were obtained in 67% of the placentitis group (2/3), 29% of the abnormal group (2/7), and 20% of the normal group (5/25). Pathological placental edema and ultrasonographic images showing uteroplacental roughness or distinguishability were observed even in the normal group. These findings suggest that increased CTUP and placental separation would reflect placentitis and abnormal pregnancies and may help to detect them in heavy draft horses.

[Structure of maxillary sinus mucous membrane under normal conditions and in odontogenic perforative sinusitis].

PubMed

Baĭdik, O D; Logvinov, S V; Zubarev, S G; Sysoliatin, P G; Gurin, A A

2011-01-01

Methods of light, electron microscopy and immunohistochemistry were used to study the samples of maxillary sinus (MS) mucous membrane (MM) under normal conditions and in odontogenic sinusitis. To study the normal structure, the samples were obtained at autopsy from 26 human corpses 12-24 hours after death. Electron microscopic and immunohistochemical study was performed on biopsies of grossly morphologically unchanged MS MM, obtained during the operations for retention cysts in 6 patients. MS MM in perforative sinusitis was studied using the biopsies obtained from 43 patients. The material is broken into 4 groups depending on perforative sinusitis duration. Under normal conditions, MS MM is lined with a pseudostratified columnar ciliated epithelium. Degenerative changes of ciliated epithelial cells were already detected at short time intervals after MS perforations and become apparent due to reduction of specific volume of mitochondria and, rough endoplasmic reticulum, and increase of nuclear-cytoplasmic ratio. In the globlet cells, the reduction of nuclear-cytoplasmic ratio was associated with the disturbance of the secretory product release. At time intervals exceeding 3 months, epithelium underwent metaplasia into simple cuboidal and stratified squamous keratinized, while in MS MM lamina propria, cellular infiltration was increased. CD4+ cell content in sinus MM gradually increased, while at late periods after perforation occurrence it decreased. Low CD4+ cell count within the epithelium and the absence of muromidase on the surface of MS MM was detected. With the increase of the time interval since MS perforation, the number of CD8+ and CD20+ cells in MS MM was found to increase.

Estimation of the Blood Pressure Response With Exercise Stress Testing.

PubMed

Fitzgerald, Benjamin T; Ballard, Emma L; Scalia, Gregory M

2018-04-20

The blood pressure response to exercise has been described as a significant increase in systolic BP (sBP) with a smaller change in diastolic BP (dBP). This has been documented in small numbers, in healthy young men or in ethnic populations. This study examines these changes in low to intermediate risk of myocardial ischaemia in men and women over a wide age range. Consecutive patients having stress echocardiography were analysed. Ischaemic tests were excluded. Manual BP was estimated before and during standard Bruce protocol treadmill testing. Patient age, sex, body mass index (BMI), and resting and peak exercise BP were recorded. 3200 patients (mean age 58±12years) were included with 1123 (35%) females, and 2077 males, age range 18 to 93 years. Systolic BP increased from 125±17mmHg to 176±23mmHg. The change in sBP (ΔsBP) was 51mmHg (95% CI 51,52). The ΔdBP was 1mmHg (95% CI 1, 1), from 77 to 78mmHg, p<0.001). The upper limit of normal peak exercise sBP (determined by the 90th percentile) was 210mmHg in males and 200mmHg in females. The upper limit of normal ΔsBP was 80mmHg in males and 70mmHg in females. The lower limit of normal ΔsBP was 30mmHg in males and 20mmHg in females. In this large cohort, sBP increased significantly with exercise. Males had on average higher values than females. Similar changes were seen with the ΔsBP. The upper limit of normal for peak exercise sBP and ΔsBP are reported by age and gender. Copyright © 2018 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). All rights reserved.

Hyperventilation in patients who have sustained myocardial infarction after a work injury.

PubMed Central

Rosen, S D; King, J C; Nixon, P G

1994-01-01

Patients who present with acute myocardial infarction after a work injury (AMI-WI) often report symptoms consistent with chronic hyperventilation which date back as far as the work injury itself, rather than to the AMI. The aim of the study was to test the hypothesis that hyperventilation significantly contributes to the symptoms of AMI-WI patients. The prevalence of hyperventilation was assessed by clinical capnography in 12 AMI-WI patients, 20 normal controls, 15 AMI patients whose AMI was conventional and not subsequent to a work injury (AMI-C) and 14 patients with post-traumatic stress disorder (PTSD). End-tidal carbon dioxide partial pressure (P(et)CO2) was measured at rest, after 1 min hyperventilation (FHPT), after recall of the relevant stressor (Think) and when the breathing was felt to be normal (MBIN). P(et)CO2 levels after FHPT were: 29.0 +/- 1.5 (mean +/- SD) mmHg for AMI-WI; 26.7 +/- 1.9 mmHg for PTSD; 32.1 +/- 4.1 mmHg for AMI-C and 33.7 +/- 1.4 mmHg for the controls (P < 0.05 and P < 0.01 for AMI-WI and PTSD, respectively, versus controls). After Think, the levels were 25.8 +/- 1.6 mmHg for AMI-WI, 24.6 +/- 1.4 mmHg for PTSD, 31.2 +/- 4.1 mmHg for AMI-C and 31.2 +/- 1.5 mmHg for normals (P < 0.05 and P < 0.01 for AMI-WI and PTSD, respectively, versus controls). For MBIN, values of P(et)CO2 were 26.8 +/- 1.7 mmHg and 26.7 +/- 1.5 mmHg for AMI-WI and PTSD versus 33.8 +/- 1.2 mmHg for normals, (P < 0.01 for both versus controls).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8207722

Determinants and Normal Values of Ascending Aortic Diameter by Age, Gender and Race/Ethnicity in the Multi-Ethnic Study of Atherosclerosis (MESA)

PubMed Central

Turkbey, Evrim B.; Jain, Aditya; Johnson, Craig; Redheuil, Alban; Arai, Andrew E.; Gomes, Antoinette S.; Carr, James; Hundley, W. Gregory; Teixido-Tura, Gisela; Eng, John; Lima, Joao A.C.; Bluemke, David A.

2013-01-01

PURPOSE To determine the normal size and wall thickness of the ascending thoracic aorta (AA) and its relationship with cardiovascular risk factors in a large population-based study. MATERIALS AND METHODS The mean AA luminal diameter was measured in 3573 Multi-Ethnic Study of Atherosclerosis (MESA) participants (age: 45–84 years), using gradient echo phase contrast cine MRI. Multiple linear regression models were used to evaluate the associations between risk factors and AA diameter. The median and upper normal limit (95th percentile) was defined in a “healthy” subgroup as well as AA wall thickness. RESULTS The upper limits of body surface area indexed AA luminal diameter for age categories of 45–54, 55–64, 65–74, and 75–84 years are 21, 22, 22, and 28 mm/m2 in women and 20, 21, 22, 23 mm/m2 in men, respectively. The mean AA wall thickness was 2.8 mm. Age, gender and body surface area were major determinants of AA luminal diameter (~+1 mm/10 years; ~+1.9 mm in men than women; ~+1 mm/ 0.23 m2; p<0.001). The AA diameter in hypertensive subjects was +0.9 mm larger than in normotensives (p<0.001). CONCLUSION AA diameter increases gradually with aging for both genders, among all race/ethnicities. Normal value of AA diameter is provided. PMID:23681649

Morphine-induced kinetic alterations of choline acetyltransferase of the rat caudate nucleus

PubMed Central

Datta, K.; Wajda, I. J.

1972-01-01

1. In order to explain the decrease of choline acetyltransferase (2.3.1.6.) activity observed in the caudate nucleus of morphine-treated rats, partially purified preparations of the enzyme were used in kinetic studies, with choline as substrate. 2. The apparent Michaelis constant for the enzyme obtained from normal rats was found to be 0·9 mM choline; this value doubled when the animals were killed one hour after a single injection of morphine (30 mg/kg). When the rats were injected daily for 4 or 15 days, and killed one hour after the last injection, the apparent Km value was 2·1 mM in each case. Prolonged daily treatment with morphine, followed by 48 h withdrawal, or by administration of 4 mg/kg of naloxone (given half an hour after the last injection of morphine) resulted in apparent Km values of 1·3-1·5 mM of choline, suggesting a gradual return to the lower, normal substrate requirement. Vmax changes were insignificant. 3. The effect of morphine added in vitro to different enzyme preparations was also studied. The Km values of 0·9 mM, in the enzyme isolated from normal rats, increased to 2·0 after incubation in vitro with 12·5 mM morphine. Similar increases were found in enzymes obtained from rats 48 h after the withdrawal of morphine or from rats injected with naloxone after prolonged morphine treatment. The high apparent Km values, found in enzyme obtained from animals killed one hour after the last dose of morphine, did not change upon incubation with 12·5 mM morphine. A similar pattern of Km changes was noticed after incubation with 25 mM acetylcholine. 4. An increase of 32% in acetylcholine (ACh) level was found in the caudate nucleus one hour after subcutaneous injection of 30 mg/kg of morphine. Return to normal values was observed when morphine was administered daily. After two to three weeks of daily treatment and subsequent withdrawal from morphine for 48 h, the levels of ACh were normal. If the daily treated rats were given naloxone within half an hour of the last injection of morphine, and killed 30 min later, the levels of ACh remained normal. 5. Fifty per cent inhibition of enzyme activity was observed upon in vitro incubation with 75 mM acetylcholine, or with 25 mM morphine. The same degree of inhibition was noticed when the enzyme was obtained from normal or from morphine-treated rats. PMID:5041452

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shaw, B. H.; Applied Science and Technology, University of California, Berkeley, California 94720; Tilborg, J. van

Solid-based surface high-harmonic generation from a tape is experimentally studied. By operating at mildly relativistic normalized laser strengths a{sub 0}≲0.2, harmonics up to the 17th order are efficiently produced in the coherent wake emission (CWE) regime. CWE pulse properties, such as divergence, energy, conversion efficiency, and spectrum, are investigated for various tape materials and drive laser conditions. A clear correlation between surface roughness and harmonic beam divergence is found. At the measured pulse properties for the 15th harmonic (conversion efficiency ∼6.5×10{sup −7}, divergence ∼7−15 mrad), the 100-mJ-level drive laser produces several MWs of extreme ultra-violet pulses. The spooling tape configurationmore » enables multi-Hz operation over thousands of shots, making this source attractive as a seed to the few-Hz laser-plasma-accelerator-driven free-electron laser (FEL). Models indicate that these CWE pulses with MW level powers are sufficient for seed-induced bunching and FEL gain.« less

Emittance of short-pulsed high-current ion beams formed from the plasma of the electron cyclotron resonance discharge sustained by high-power millimeter-wave gyrotron radiation.

PubMed

Razin, S; Zorin, V; Izotov, I; Sidorov, A; Skalyga, V

2014-02-01

We present experimental results on measuring the emittance of short-pulsed (≤100 μs) high-current (80-100 mA) ion beams of heavy gases (Nitrogen, Argon) formed from a dense plasma of an ECR source of multiply charged ions (MCI) with quasi-gas-dynamic mode of plasma confinement in a magnetic trap of simple mirror configuration. The discharge was created by a high-power (90 kW) pulsed radiation of a 37.5-GHz gyrotron. The normalized emittance of generated ion beams of 100 mA current was (1.2-1.3) π mm mrad (70% of ions in the beams). Comparing these results with those obtained using a cusp magnetic trap, it was concluded that the structure of the trap magnetic field lines does not exert a decisive influence on the emittance of ion beams in the gas-dynamic ECR source of MCI.

Emittance of short-pulsed high-current ion beams formed from the plasma of the electron cyclotron resonance discharge sustained by high-power millimeter-wave gyrotron radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Razin, S., E-mail: sevraz@appl.sci-nnov.ru; Zorin, V.; Izotov, I.

2014-02-15

We present experimental results on measuring the emittance of short-pulsed (≤100 μs) high-current (80–100 mA) ion beams of heavy gases (Nitrogen, Argon) formed from a dense plasma of an ECR source of multiply charged ions (MCI) with quasi-gas-dynamic mode of plasma confinement in a magnetic trap of simple mirror configuration. The discharge was created by a high-power (90 kW) pulsed radiation of a 37.5-GHz gyrotron. The normalized emittance of generated ion beams of 100 mA current was (1.2–1.3) π mm mrad (70% of ions in the beams). Comparing these results with those obtained using a cusp magnetic trap, it was concluded thatmore » the structure of the trap magnetic field lines does not exert a decisive influence on the emittance of ion beams in the gas-dynamic ECR source of MCI.« less

The Effects of ELDRS at Ultra-Low Dose Rates

NASA Technical Reports Server (NTRS)

Chen, Dakai; Forney, James; Carts, Martin; Phan, Anthony; Cox, Stephen; Kruckmeyer, Kirby; Burns, Sam; Albarian, Rafi; Holcombe, Bruce; Little, Bradley;

CHANGES IN SPOILAGE PATTERN OF CHICKEN MEAT AS A RESULT OF IRRADIATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ingram, M.; Thornley, M.J.

1959-10-01

The microflora of radiation-pasteurized chicken meat is described in detail. With anaerobic minced meat kept at 5 deg C, doses of 0.25 Mrad delayed spoilage for several weeks. The ultimate spoilage flora consisted of microbacteria and faecal streptococci. The enrichment of the latter raises misgivings about this type of process. With whole eviscerated chickens. stored at 1 to 3 deg C in loose film bags, doses up to 0.8 Mrad increased the storage life roughly from 10 to 50 days. The spoilage microflora was somewhat different in different experiments, and corresponding differences were observed in the off- odors which heraldedmore » spoilage. In all cases, however, the principal organisms were bacteria of types common on chilled meat. It is concluded that there are no special bacteriological indications against radiation pasteurized meats, provided they are packed in air and kept at chill temperatures. (auth)« less

Control of quasi-monoenergetic electron beams from laser-plasma accelerators with adjustable shock density profile

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsai, Hai-En; Swanson, Kelly K.; Barber, Sam K.

The injection physics in a shock-induced density down-ramp injector was characterized, demonstrating precise control of a laser-plasma accelerator (LPA). Using a jet-blade assembly, experiments systematically v aried the shock injector profile, including shock angle, shock position, up-ramp width, and acceleration length. Our work demonstrates that beam energy, energy spread, and pointing can be controlled by adjusting these parameters. As a result, an electron beam that was highly tunable from 25 to 300 MeV with 8% energy spread (ΔE FWHM/E), 1.5 mrad divergence, and 0.35 mrad pointing fluctuation was produced. Particle-in-cell simulation characterized how variation in the shock angle and up-rampmore » width impacted the injection process. This highly controllable LPA represents a suitable, compact electron beam source for LPA applications such as Thomson sources and free-electron lasers.« less

A design study for a compact two stage in-flight separator with a high mass resolution and large acceptance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hwang, Ji-Gwang; Kim, Eun-San, E-mail: eskim1@knu.ac.kr; Hatanaka, Kichiji

2015-03-15

The rare isotope beam separator with a large angular acceptance and energy acceptance is essential for examining the characteristics of unstable nuclei and exotic nuclear reactions. Careful design, however, is required to compensate for the effects of high order aberrations induced by large aperture magnets, which are used to collect rare isotopes obtained from a high energy primary heavy-ion beam hitting a target. In order to minimize the effect of the high order aberration, the optics was based on the mirror symmetry optics, which provides smaller high order aberrations, for the separation of {sup 132}Sn produced by a fission reactionmore » between the primary beam of {sup 238}U and a relatively thick Pb target. The designed optics provides energy acceptance (full), horizontal angular acceptance, and vertical acceptance of approximately 8%, 60 mrad, and 130 mrad, respectively.« less

Radiation mapping on Spacelab 1: Experiment no. INS006

NASA Technical Reports Server (NTRS)

Benton, E. V.; Frank, A.; Cassou, R.; Henke, R.; Rowe, V.

1985-01-01

The first attempt at mapping the radiation environment inside Spacelab is described. Measurements were made by a set of passive radiation detectors distributed throughout the volume inside the Spacelab 1 module, in the access tunnel and outside on the pallet. Measurements of the low linear energy transfer (LET) component obtained from the TLD thermoluminescent detectors (TLD) ranged from 92 to 134 mrad, yielding an average low LET dose rate of 10.0 mrads/day inside the module. Because of the higher inclination orbit, substantial fluxes of highly ionizing (HZE particles) high charge and energy galactic cosmic rays were observed for the first time on an STS flight, yielding an overall average mission dose-equivalent of 295 mrem, or 29.5 mrem/day, which is about three times higher than that measured on previous STS missions. Little correlation is found between measured average dose rates or HZE fluences and the estimates shielding throughout the volume of the module.

Optical phase conjugation by four-wave mixing in Nd:YAG laser oscillator for optical energy transfer to a remote target

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kawakami, K., E-mail: k.kawakami@al.t.u-tokyo.ac.jp; Komurasaki, K.; Okamura, H.

2015-02-28

A self-starting phase conjugator was designed for optical energy transfer to a remote target. Saturable-gain four-wave mixing in a laser resonator was achieved using a flash-lamp pumped Nd:YAG crystal and phase-conjugate light (PCL) generation were verified. Wavefront correction experimentation revealed that beam wander caused by air turbulence is compensated. Tracking capability was demonstrated in the range of 9 mrad with tracking accuracy of ±0.04 mrad. The maximum field of view was measured to be 4.7°. Dependence of phase-conjugate light energy on reference light energy was investigated. The maximum output of 320 mJ was obtained. The temporal behavior of PCL ismore » discussed based on the four-wave mixing mechanism. Unlike a conventional loop resonator type phase conjugator, this system is applicable for wireless energy transfer to a remote target.« less

5 MeV Proton irradiation effects on 200 GHz silicon-germanium heterojunction bipolar transistors

NASA Astrophysics Data System (ADS)

Gnana Prakash, A. P.; Hegde, Vinayakprasanna N.; Pradeep, T. M.; Pushpa, N.; Bajpai, P. K.; Patel, S. P.; Trivedi, Tarkeshwar; Cressler, J. D.

2017-12-01

The total dose effects of 5 MeV proton and Co-60 gamma irradiation in the dose range from 1 to 100 Mrad on advanced 200 GHz Silicon-Germanium heterojunction bipolar transistors (SiGe HBTs) are investigated. The SRIM simulation study was conducted to understand the energy loss of 5 MeV proton ions in SiGe HBT structure. Pre- and post-radiation DC figure of merits such as forward- and inverse-mode Gummel characteristics, excess base current, DC current gain and output characteristics were used to quantify the radiation tolerance of the devices. The results show that the proton creates a significant amount of damages in the surface and bulk of the transistor when compared with gamma irradiation. The SiGe HBTs shows robust ionizing radiation tolerance even up to a total dose of 100 Mrad for both radiations.

Control of quasi-monoenergetic electron beams from laser-plasma accelerators with adjustable shock density profile

DOE PAGES

Tsai, Hai-En; Swanson, Kelly K.; Barber, Sam K.; ...

2018-04-13

The injection physics in a shock-induced density down-ramp injector was characterized, demonstrating precise control of a laser-plasma accelerator (LPA). Using a jet-blade assembly, experiments systematically v aried the shock injector profile, including shock angle, shock position, up-ramp width, and acceleration length. Our work demonstrates that beam energy, energy spread, and pointing can be controlled by adjusting these parameters. As a result, an electron beam that was highly tunable from 25 to 300 MeV with 8% energy spread (ΔE FWHM/E), 1.5 mrad divergence, and 0.35 mrad pointing fluctuation was produced. Particle-in-cell simulation characterized how variation in the shock angle and up-rampmore » width impacted the injection process. This highly controllable LPA represents a suitable, compact electron beam source for LPA applications such as Thomson sources and free-electron lasers.« less

Large deflection angle, high-power adaptive fiber optics collimator with preserved near-diffraction-limited beam quality.

PubMed

Zhi, Dong; Ma, Yanxing; Chen, Zilun; Wang, Xiaolin; Zhou, Pu; Si, Lei

2016-05-15

We report on the development of a monolithic adaptive fiber optics collimator, with a large deflection angle and preserved near-diffraction-limited beam quality, that has been tested at a maximal output power at the 300 W level. Additionally, a new measurement method of beam quality (M² factor) is developed. Experimental results show that the deflection angle of the collimated beam is in the range of 0-0.27 mrad in the X direction and 0-0.19 mrad in the Y direction. The effective working frequency of the device is about 710 Hz. By employing the new measurement method of the M² factor, we calculate that the beam quality is Mx2=1.35 and My2=1.24, which is in agreement with the result from the beam propagation analyzer and is preserved well with the increasing output power.

A design study for a compact two stage in-flight separator with a high mass resolution and large acceptance.

PubMed

Hwang, Ji-Gwang; Kim, Eun-San; Hatanaka, Kichiji

2015-03-01

The rare isotope beam separator with a large angular acceptance and energy acceptance is essential for examining the characteristics of unstable nuclei and exotic nuclear reactions. Careful design, however, is required to compensate for the effects of high order aberrations induced by large aperture magnets, which are used to collect rare isotopes obtained from a high energy primary heavy-ion beam hitting a target. In order to minimize the effect of the high order aberration, the optics was based on the mirror symmetry optics, which provides smaller high order aberrations, for the separation of (132)Sn produced by a fission reaction between the primary beam of (238)U and a relatively thick Pb target. The designed optics provides energy acceptance (full), horizontal angular acceptance, and vertical acceptance of approximately 8%, 60 mrad, and 130 mrad, respectively.

Thermal response of solar receiver aperture plates during sun walk-off

NASA Technical Reports Server (NTRS)

Wen, L.; Roschke, J.

1982-01-01

The tracking mechanism for a point-focusing concentrator may be subject to failure. If this should occur, the solar image will travel across the aperture plate, and it may also impinge on the adjacent support structure. Such an event is called 'sun walk-off'. The present investigation is concerned with the transient response of different aperture plate materials to the intense heating produced in a typical walk-off situation for parabolic dish concentrators. Receivers for two solar module systems are considered, including a high-temperature receiver that utilizes a 2-milliradian (mrad) concentrator, and a lower-temperature receiver which is coupled with a 4-mrad concentrator. It is found that during a walk-off situation the solar image travels in a straight line in the radial direction. The results obtained for a copper aperture plate were disappointing. It appears that passive metallic plates without cooling or other protective support cannot withstand the intense heating.

LIF standoff research

NASA Astrophysics Data System (ADS)

Olson, C. L.; Cuneo, M. E.; Desjarlais, M. P.; Filuk, A. B.; Greenly, J. B.; Hanson, D. L.; Hinshelwood, D. D.; Hubbard, R. F.; Lampe, M.; Lockner, T. R.

Present Light Ion Fusion (LIF) target experiments on PBFA 2 use a barrel diode in which the total transport length from the anode to the target is less than or equal to 15 cm. Future LIF development includes high yield applications (LMF) and energy production (ETF and LIBRA power plants) that require standoff - the generation of extracted ion beams and transport of these beams over distances of several meters. Standoff research includes the development of high efficiency extraction diodes (single stage and two-stage), improvements in beam quality (divergence, purity, uniformity, etc.), and the efficient transport and focusing of these beams over distances of several meters to a fusion target. Progress in all of these areas is discussed, as well as a strategy to reduce the divergence from the present 17 mrad for 5 MeV protons on SABRE to the required mrad for 35 MeV Li ions for LMF. The status of experiments is summarized, and future directions are indicated.

A design study for a compact two stage in-flight separator with a high mass resolution and large acceptance

NASA Astrophysics Data System (ADS)

Hwang, Ji-Gwang; Kim, Eun-San; Hatanaka, Kichiji

2015-03-01

The rare isotope beam separator with a large angular acceptance and energy acceptance is essential for examining the characteristics of unstable nuclei and exotic nuclear reactions. Careful design, however, is required to compensate for the effects of high order aberrations induced by large aperture magnets, which are used to collect rare isotopes obtained from a high energy primary heavy-ion beam hitting a target. In order to minimize the effect of the high order aberration, the optics was based on the mirror symmetry optics, which provides smaller high order aberrations, for the separation of 132Sn produced by a fission reaction between the primary beam of 238U and a relatively thick Pb target. The designed optics provides energy acceptance (full), horizontal angular acceptance, and vertical acceptance of approximately 8%, 60 mrad, and 130 mrad, respectively.

Control of quasi-monoenergetic electron beams from laser-plasma accelerators with adjustable shock density profile

NASA Astrophysics Data System (ADS)

Tsai, Hai-En; Swanson, Kelly K.; Barber, Sam K.; Lehe, Remi; Mao, Hann-Shin; Mittelberger, Daniel E.; Steinke, Sven; Nakamura, Kei; van Tilborg, Jeroen; Schroeder, Carl; Esarey, Eric; Geddes, Cameron G. R.; Leemans, Wim

2018-04-01

The injection physics in a shock-induced density down-ramp injector was characterized, demonstrating precise control of a laser-plasma accelerator (LPA). Using a jet-blade assembly, experiments systematically varied the shock injector profile, including shock angle, shock position, up-ramp width, and acceleration length. Our work demonstrates that beam energy, energy spread, and pointing can be controlled by adjusting these parameters. As a result, an electron beam that was highly tunable from 25 to 300 MeV with 8% energy spread (ΔEFWHM/E), 1.5 mrad divergence, and 0.35 mrad pointing fluctuation was produced. Particle-in-cell simulation characterized how variation in the shock angle and up-ramp width impacted the injection process. This highly controllable LPA represents a suitable, compact electron beam source for LPA applications such as Thomson sources and free-electron lasers.

Experimental and Theoretical Investigations on Bond Strength of GFRP Rebars in Normal and High Strength Concrete

NASA Astrophysics Data System (ADS)

Eswanth, P.; Dhinakaran, G.

2017-07-01

Bond behavior between GFRP bars and concrete is the most important parameter for constructing corrosion free structures by implementing the material. Serviceability of reinforced concrete structures are controlled by bond behavior. GFRP materials behave differently from reinforcing steel in terms of bond. They are of non-homogeneous and anisotropic. Due to this outstanding behavior, there is a difference in transfer of loads between GFRP bars and concrete which made it as an idealized choice of a material. In the present work, the bond strength of GFRP bars in normal and high strength concrete was studied. In total, 12 specimens containing 12 mm, 16 mm diameter rebars which were embedded in 150 mm x 150 mm x 150 mm cubes were investigated. The specimens were subjected to direct tension pull out test in accordance with IS 2770 part 1. The comparison of bond properties of GFRP rebar in normal and high strength concrete showed that pull out load of non-metallic rebar fell well within the range.

Experimental and calculated LET distributions in the Cosmos-2044 biosatellite orbit

NASA Technical Reports Server (NTRS)

Dudkin, V. E.; Karpov, O. N.; Akopova, A. B.; Magradze, N. V.; Moiseenko, A. A.; Benton, E. V.; Frank, A. L.; Watts, J. W. Jr

1992-01-01

During the flight of the Cosmos-2044 biosatellite, joint U.S.S.R.-U.S.A. investigations of different characteristics of cosmic radiation (CR) in the near-Earth environment were carried out. The U.S. dielectric track detectors CR-39 and Soviet BYa- and BR-type nuclear photo-emulsions were used as detectors. The present work shows some results of experimental measurements of linear energy transfer (LET) spectra of CR particles obtained with the use of these detectors, which were placed both inside and outside the satellite. The LET spectra measurement with plastic detectors is composed of two parts: the measurement of galactic cosmic rays (GCR) particles, and of short-range particles. The contributions of these components to the total LET distribution at various thicknesses of the shielding were analyzed and the results of these studies are presented. Calculated LET spectra in the Cosmos-2044 orbit were compared with experimental data. On the basis of experimental and calculated values of the LET spectra, absorbed and equivalent CR doses were calculated. In the shielding range of 1-1.5 g cm-2, outside the spacecraft, the photo-emulsions yielded 10.3 mrad d-1 and 27.5 mrem d-1 (LET > or = 2 MeV cm-1) while the CR-39 yielded averages of 1.43 mrad d-1 and 13.4 mrem d-1 (LET > or = 40 MeV cm-1). Inside the spacecraft (> or = 10 g cm-2) the photo-emulsions yielded 8.9 mrad d-1 and 14.5 mrem d-1.

Ultrasonographic characteristics of the abdominal esophagus and cardia in dogs.

PubMed

Gory, Guillaume; Rault, Delphine N; Gatel, Laure; Dally, Claire; Belli, Patrick; Couturier, Laurent; Cauvin, Eddy

2014-01-01

Differential diagnoses for regurgitation and vomiting in dogs include diseases of the gastroesophageal junction. The purpose of this cross-sectional study was to describe ultrasonographic characteristics of the abdominal esophagus and gastric cardia in normal dogs and dogs with clinical disease involving this region. A total of 126 dogs with no clinical signs of gastrointestinal disease and six dogs with clinical diseases involving the gastroesophageal junction were included. For seven euthanized dogs, ultrasonographic features were also compared with gross pathology and histopathology. Cardial and abdominal esophageal wall thicknesses were measured ultrasonographically for all normal dogs and effects of weight, sex, age, and stomach filling were tested. Five layers could be identified in normal esophageal and cardial walls. The inner esophageal layer was echogenic, corresponding to the cornified mucosa and glandular portion of the submucosa. The cardia was characterized by a thick muscularis, and a transitional zone between echogenic esophageal and hypoechoic gastric mucosal layers. Mean (±SD) cardial wall thicknesses for normal dogs were 7.6 mm (±1.6), 9.7 mm (±1.8), 10.8 mm (±1.6), 13.3 mm (±2.5) for dogs in the <10 kg, 10-19.9 kg, 20-29.9 kg and ≥30 kg weight groups, respectively. Mean (±SD) esophageal wall thicknesses were: 4.1 mm (±0.6), 5.1 mm (±1.3), 5.6 mm (±1), and 6.4 mm (±1.1) for the same weight groups, respectively. Measurements of wall thickness were significantly correlated with dog weight group. Ultrasonography assisted diagnosis in all six clinically affected dogs. Findings supported the use of transabdominal ultrasonography as a diagnostic test for dogs with suspected gastroesophageal disease. © 2014 American College of Veterinary Radiology.

Increased Risk of Revision After Anterior Cruciate Ligament Reconstruction With Bone-Patellar Tendon-Bone Allografts Compared With Autografts.

PubMed

Maletis, Gregory B; Chen, Jason; Inacio, Maria C S; Love, Rebecca M; Funahashi, Tadashi T

2017-05-01

The use of allograft tissue for anterior cruciate ligament reconstruction (ACLR) remains controversial. To compare the risk of aseptic revision between bone-patellar tendon-bone (BPTB) autografts and BPTB allografts. Cohort study; Level of evidence, 2. A retrospective cohort study of prospectively collected data was conducted using the Kaiser Permanente ACLR Registry. A cohort of patients who underwent primary unilateral ACLR with BPTB autografts and BPTB allografts was identified. Aseptic revision was the endpoint. The type of graft and allograft processing method (nonprocessed, <1.8-Mrad, and ≥1.8-Mrad irradiation) were the exposures of interest evaluated. Age (≤21 and ≥22 years) was evaluated as an effect modifier. Analyses were adjusted for age, sex, and race. Kaplan-Meier curves and Cox proportional hazards models were employed. Hazard ratios (HRs) and 95% CIs are provided. The BPTB cohort consisted of 5586 patients: 3783 (67.7%) were male, 2359 (42.2%) were white, 1029 (18.4%) had allografts (nonprocessed: 155; <1.8 Mrad: 525; ≥1.8 Mrad: 288), and 4557 (81.6%) had autografts. The median age was 34.9 years (interquartile range [IQR], 25.4-44.0) for allograft cases and 22.0 years (IQR, 17.6-30.0) for autograft cases. The estimated cumulative revision rate at 2 years was 4.1% (95% CI, 2.9%-5.9%) for allografts and 1.7% (95% CI, 1.3%-2.2%) for autografts. BPTB allografts had a significantly higher adjusted risk of revision than BPTB autografts (HR, 4.54; 95% CI, 3.03-6.79; P < .001). This higher risk of revision was consistent with all allograft processing methods when compared with autografts and was also consistently higher in patients with allografts regardless of age. When BPTB allograft tissue was used for ACLR, an overall 4.54 times adjusted higher risk of revision was observed compared with surgery performed with a BPTB autograft. Whether the tissue was irradiated with either high- or low-dose radiation, chemically processed, or not processed at all made little difference in the risk of revision. The differences in the revision risk were also consistent in younger and older patients. Surgeons and patients should be aware of the increased risk of revision when a BPTB allograft is used for ACLR.

Runoff and leaching of metolachlor from Mississippi River alluvial soil during seasons of average and below-average rainfall.

PubMed

Southwick, Lloyd M; Appelboom, Timothy W; Fouss, James L

2009-02-25

The movement of the herbicide metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide] via runoff and leaching from 0.21 ha plots planted to corn on Mississippi River alluvial soil (Commerce silt loam) was measured for a 6-year period, 1995-2000. The first three years received normal rainfall (30 year average); the second three years experienced reduced rainfall. The 4-month periods prior to application plus the following 4 months after application were characterized by 1039 +/- 148 mm of rainfall for 1995-1997 and by 674 +/- 108 mm for 1998-2000. During the normal rainfall years 216 +/- 150 mm of runoff occurred during the study seasons (4 months following herbicide application), accompanied by 76.9 +/- 38.9 mm of leachate. For the low-rainfall years these amounts were 16.2 +/- 18.2 mm of runoff (92% less than the normal years) and 45.1 +/- 25.5 mm of leachate (41% less than the normal seasons). Runoff of metolachlor during the normal-rainfall seasons was 4.5-6.1% of application, whereas leaching was 0.10-0.18%. For the below-normal periods, these losses were 0.07-0.37% of application in runoff and 0.22-0.27% in leachate. When averages over the three normal and the three less-than-normal seasons were taken, a 35% reduction in rainfall was characterized by a 97% reduction in runoff loss and a 71% increase in leachate loss of metolachlor on a percent of application basis. The data indicate an increase in preferential flow in the leaching movement of metolachlor from the surface soil layer during the reduced rainfall periods. Even with increased preferential flow through the soil during the below-average rainfall seasons, leachate loss (percent of application) of the herbicide remained below 0.3%. Compared to the average rainfall seasons of 1995-1997, the below-normal seasons of 1998-2000 were characterized by a 79% reduction in total runoff and leachate flow and by a 93% reduction in corresponding metolachlor movement via these routes. An added observation in the study was that neither runoff of rainfall nor runoff loss of metolachlor was influenced by the presence of subsurface drains, compared to the results from plots without such drains that were described in an earlier paper.

[Metformin and changes in blood pressure and heart rate in lean patients with polycystic ovary syndrome (PCOS)--preliminary study].

PubMed

Tomczyk, Rita; Ociepka, Agnieszka; Kiałka, Marta; Milewicz, Tomasz; Migacz, Kamila; Kowalczuk, Aleksandra; Klocek, Marek

2015-01-01

The aim of our study was to assess the value of blood pressure and heart rate using the 24-hour blood pressure monitoring (ABPM) before and after treatment with metformin to patients with polycystic ovary syndrome (PCOS) and normal lean. 5 patients received metformin 1500 mg per day in three divided doses. ABPM was performed to each patient with PCOS twice: before and after 6 months of treatment with metformin. In patients with PCOS and normal lean after treatment with metformin we observed: statistically significant lower systolic blood pressure (120.2 ± 22.33 mmHg vs 113.22 ± 21.43 mm Hg, p = 0.0248); lower systolic blood pressure of daily measurements (127.1 ± 32.13 mmHg vs 116.1 ± 22.08 mmHg, p = 0.0062); reduction in average arterial pressure MAP in the measurement of the day (95.52 ± 22.76 mmHg vs 88.36 ± 16.41 mmHg, p = 0.048); oscillometric pressure reduction (96.27 ± 27.93 mmHg vs 87.82 ± 21.61, p = 0.0004 mmHg); oscillometric pressure reduction of daily measurements (102.1 ± 27.93 mmHg vs 91.85 ± 21.61 mmHg, p = 0.0032); oscillometric pressure reduction in the measure- ment of the night (88.81 ± 24.85 mmHg vs 82.22 ± 20.54 mmHg, p = 0.0089). In women after treatment with metformin has also been observed higher average heart rate (65.82 ± 13.48 / min vs. 70.71 ± 16.04 min; p < 0.01). The calculations included 500 measurements. Treatment with metformin in patients with PCOS and normal lean leads to lower blood pressure and increases the frequency of heart rate.

Quantifying Normal Craniofacial Form and Baseline Craniofacial Asymmetry in the Pediatric Population.

PubMed

Cho, Min-Jeong; Hallac, Rami R; Ramesh, Jananie; Seaward, James R; Hermann, Nuno V; Darvann, Tron A; Lipira, Angelo; Kane, Alex A

2018-03-01

Restoring craniofacial symmetry is an important objective in the treatment of many craniofacial conditions. Normal form has been measured using anthropometry, cephalometry, and photography, yet all of these modalities have drawbacks. In this study, the authors define normal pediatric craniofacial form and craniofacial asymmetry using stereophotogrammetric images, which capture a densely sampled set of points on the form. After institutional review board approval, normal, healthy children (n = 533) with no known craniofacial abnormalities were recruited at well-child visits to undergo full head stereophotogrammetric imaging. The children's ages ranged from 0 to 18 years. A symmetric three-dimensional template was registered and scaled to each individual scan using 25 manually placed landmarks. The template was deformed to each subject's three-dimensional scan using a thin-plate spline algorithm and closest point matching. Age-based normal facial models were derived. Mean facial asymmetry and statistical characteristics of the population were calculated. The mean head asymmetry across all pediatric subjects was 1.5 ± 0.5 mm (range, 0.46 to 4.78 mm), and the mean facial asymmetry was 1.2 ± 0.6 mm (range, 0.4 to 5.4 mm). There were no significant differences in the mean head or facial asymmetry with age, sex, or race. Understanding the "normal" form and baseline distribution of asymmetry is an important anthropomorphic foundation. The authors present a method to quantify normal craniofacial form and baseline asymmetry in a large pediatric sample. The authors found that the normal pediatric craniofacial form is asymmetric, and does not change in magnitude with age, sex, or race.

Nailfold capillary patterns in healthy subjects: a real issue in capillaroscopy.

PubMed

Ingegnoli, Francesca; Gualtierotti, Roberta; Lubatti, Chiara; Bertolazzi, Chiara; Gutierrez, Marwin; Boracchi, Patrizia; Fornili, Marco; De Angelis, Rossella

2013-11-01

Nailfold capillaroscopy has been extensively applied in a broad spectrum of pathologic conditions, but very few data have been published in healthy individuals. The aim of this study was to describe the nailfold capillary findings on a large series of healthy subjects using the video-capillaroscopy technique. Nailfold capillaries were studied based on their morphology, dimensions and density. Then, to evaluate jointly the association between different capillary findings in groups of subjects which were homogeneous for their characteristics, cluster analysis was performed. The results (median) of capillary measurements were as follows: loop length 207μm, external diameter 39μm, internal diameter 17μm, apical diameter 17μm, and intercapillary distance 143μm. Based on the cluster analysis three major "normal" morphologic capillaroscopic patterns were depicted: 1) the "normal" pattern mainly with 2 to 5 U-shaped loops/mm and ≤2 tortuous loops/mm; 2) the "perfect normal" pattern with ≥5 U-shaped loops/mm and 3) the "unusual normal" with at least 1 meandering or bushy loop, or at least 1 microhemorrhage, or with >4 crossed loops/mm. Regarding the loop measurements, the majority of subjects had a median of 7capillaries/mm with a median length of 198μm. © 2013 Elsevier Inc. All rights reserved.

Ultracompact/ultralow power electron cyclotron resonance ion source for multipurpose applications.

PubMed

Sortais, P; Lamy, T; Médard, J; Angot, J; Latrasse, L; Thuillier, T

2010-02-01

In order to drastically reduce the power consumption of a microwave ion source, we have studied some specific discharge cavity geometries in order to reduce the operating point below 1 W of microwave power (at 2.45 GHz). We show that it is possible to drive an electron cyclotron resonance ion source with a transmitter technology similar to those used for cellular phones. By the reduction in the size and of the required microwave power, we have developed a new type of ultralow cost ion sources. This microwave discharge system (called COMIC, for COmpact MIcrowave and Coaxial) can be used as a source of light, plasma or ions. We will show geometries of conductive cavities where it is possible, in a 20 mm diameter chamber, to reduce the ignition of the plasma below 100 mW and define typical operating points around 5 W. Inside a simple vacuum chamber it is easy to place the source and its extraction system anywhere and fully under vacuum. In that case, current densities from 0.1 to 10 mA/cm(2) (Ar, extraction 4 mm, 1 mAe, 20 kV) have been observed. Preliminary measurements and calculations show the possibility, with a two electrodes system, to extract beams within a low emittance. The first application for these ion sources is the ion injection for charge breeding, surface analyzing system and surface treatment. For this purpose, a very small extraction hole is used (typically 3/10 mm for a 3 microA extracted current with 2 W of HF power). Mass spectrum and emittance measurements will be presented. In these conditions, values down to 1 pi mm mrad at 15 kV (1sigma) are observed, thus very close to the ones currently observed for a surface ionization source. A major interest of this approach is the possibility to connect together several COMIC devices. We will introduce some new on-going developments such as sources for high voltage implantation platforms, fully quartz radioactive ion source at ISOLDE or large plasma generators for plasma immersion, broad or ribbon beams generation.

Development of a novel precision instrument for high-resolution simultaneous normal and shear force measurements between small planar samples

NASA Astrophysics Data System (ADS)

Lundstrom, Troy; Clark, William; Jalili, Nader

2017-05-01

In the design and development of end effector pads for silicon wafer handling robots, it is imperative that the static friction/adhesion force properties of the pads with respect to a variety of planar surfaces be characterized. In this work, the overall design, calibration, and data acquisition procedure of an instrument developed for performing these measurements on small (<10 mm × 10 mm) planar samples is presented. This device was used to perform adhesion/maximum shear force measurements on polydimethylsiloxane, a silicon wafer, and custom carbon nanotubes forest surfaces. The device was successfully able to measure an effective, mean profile adhesion force of 715 μN between a silicon wafer and a polydimethylsiloxane (2.768 × 10-6 m2) sample. In addition, a nonlinear maximum shear over normal force relationship was also measured between custom carbon nanotubes forest and the silicon wafer surfaces. The maximum shear over a normal force coefficient was found to decrease with increasing initial normal force. Currently, there are numerous devices for measuring normal/shear forces at the nano/micro- and macroscales; however, this device allows for the consistent measurement of these same types of forces on components with surface dimensions ranging from 0.1 mm to 10 mm.

Significance of White-Coat Hypertension in Older Persons With Isolated Systolic Hypertension

PubMed Central

Franklin, Stanley S.; Thijs, Lutgarde; Hansen, Tine W.; Li, Yan; Boggia, José; Kikuya, Masahiro; Björklund-Bodegård, Kristina; Ohkubo, Takayoshi; Jeppesen, Jørgen; Torp-Pedersen, Christian; Dolan, Eamon; Kuznetsova, Tatiana; Stolarz-Skrzypek, Katarzyna; Tikhonoff, Valérie; Malyutina, Sofia; Casiglia, Edoardo; Nikitin, Yuri; Lind, Lars; Sandoya, Edgardo; Kawecka-Jaszcz, Kalina; Imai, Yutaka; Wang, Jiguang; Ibsen, Hans; O’Brien, Eoin; Staessen, Jan A.

2013-01-01

The significance of white-coat hypertension in older persons with isolated systolic hypertension remains poorly understood. We analyzed subjects from the population-based 11-country International Database on Ambulatory Blood Pressure Monitoring in Relation to Cardiovascular Outcomes database who had daytime ambulatory blood pressure (BP; ABP) and conventional BP (CBP) measurements. After excluding persons with diastolic hypertension by CBP (≥90 mm Hg) or by daytime ABP (≥85 mm Hg), a history of cardiovascular disease, and persons <18 years of age, the present analysis totaled 7295 persons, of whom 1593 had isolated systolic hypertension. During a median follow-up of 10.6 years, there was a total of 655 fatal and nonfatal cardiovascular events. The analyses were stratified by treatment status. In untreated subjects, those with white-coat hypertension (CBP ≥140/<90 mm Hg and ABP <135/<85 mm Hg) and subjects with normal BP (CBP <140/<90 mm Hg and ABP <135/<85 mm Hg) were at similar risk (adjusted hazard rate: 1.17 [95% CI: 0.87–1.57]; P=0.29). Furthermore, in treated subjects with isolated systolic hypertension, the cardiovascular risk was similar in elevated conventional and normal daytime systolic BP as compared with those with normal conventional and normal daytime BPs (adjusted hazard rate: 1.10 [95% CI: 0.79–1.53]; P=0.57). However, both treated isolated systolic hypertension subjects with white-coat hypertension (adjusted hazard rate: 2.00; [95% CI: 1.43–2.79]; P<0.0001) and treated subjects with normal BP (adjusted hazard rate: 1.98 [95% CI: 1.49–2.62]; P<0.0001) were at higher risk as compared with untreated normotensive subjects. In conclusion, subjects with sustained hypertension who have their ABP normalized on antihypertensive therapy but with residual white-coat effect by CBP measurement have an entity that we have termed, “treated normalized hypertension.” Therefore, one should be cautious in applying the term “white-coat hypertension” to persons receiving antihypertensive treatment. PMID:22252396

Significance of white-coat hypertension in older persons with isolated systolic hypertension: a meta-analysis using the International Database on Ambulatory Blood Pressure Monitoring in Relation to Cardiovascular Outcomes population.

PubMed

Franklin, Stanley S; Thijs, Lutgarde; Hansen, Tine W; Li, Yan; Boggia, José; Kikuya, Masahiro; Björklund-Bodegård, Kristina; Ohkubo, Takayoshi; Jeppesen, Jørgen; Torp-Pedersen, Christian; Dolan, Eamon; Kuznetsova, Tatiana; Stolarz-Skrzypek, Katarzyna; Tikhonoff, Valérie; Malyutina, Sofia; Casiglia, Edoardo; Nikitin, Yuri; Lind, Lars; Sandoya, Edgardo; Kawecka-Jaszcz, Kalina; Imai, Yutaka; Wang, Jiguang; Ibsen, Hans; O'Brien, Eoin; Staessen, Jan A

2012-03-01

The significance of white-coat hypertension in older persons with isolated systolic hypertension remains poorly understood. We analyzed subjects from the population-based 11-country International Database on Ambulatory Blood Pressure Monitoring in Relation to Cardiovascular Outcomes database who had daytime ambulatory blood pressure (BP; ABP) and conventional BP (CBP) measurements. After excluding persons with diastolic hypertension by CBP (≥90 mm Hg) or by daytime ABP (≥85 mm Hg), a history of cardiovascular disease, and persons <18 years of age, the present analysis totaled 7295 persons, of whom 1593 had isolated systolic hypertension. During a median follow-up of 10.6 years, there was a total of 655 fatal and nonfatal cardiovascular events. The analyses were stratified by treatment status. In untreated subjects, those with white-coat hypertension (CBP ≥140/<90 mm Hg and ABP <135/<85 mm Hg) and subjects with normal BP (CBP <140/<90 mm Hg and ABP <135/<85 mm Hg) were at similar risk (adjusted hazard rate: 1.17 [95% CI: 0.87-1.57]; P=0.29). Furthermore, in treated subjects with isolated systolic hypertension, the cardiovascular risk was similar in elevated conventional and normal daytime systolic BP as compared with those with normal conventional and normal daytime BPs (adjusted hazard rate: 1.10 [95% CI: 0.79-1.53]; P=0.57). However, both treated isolated systolic hypertension subjects with white-coat hypertension (adjusted hazard rate: 2.00; [95% CI: 1.43-2.79]; P<0.0001) and treated subjects with normal BP (adjusted hazard rate: 1.98 [95% CI: 1.49-2.62]; P<0.0001) were at higher risk as compared with untreated normotensive subjects. In conclusion, subjects with sustained hypertension who have their ABP normalized on antihypertensive therapy but with residual white-coat effect by CBP measurement have an entity that we have termed, "treated normalized hypertension." Therefore, one should be cautious in applying the term "white-coat hypertension" to persons receiving antihypertensive treatment.

On the Possibility of Creating a Point-Like Neutron Source

NASA Astrophysics Data System (ADS)

Golubev, S. V.; Skalyga, V. A.; Izotov, I. V.; Sidorov, A. V.; Razin, S. V.; Shaposhnikov, R. A.; Lapin, R. L.; Bokhanov, A. F.; Kazakov, M. Yu.

2018-03-01

We consider the possibility of creating a compact high-power neutron generator with a small emitting area (of the order of 100 μm) and a neutron yield of 1010s-1 on the basis of a deuterium-deuterium fusion reaction (or 1012 s-1 on the basis of a deuterium-tritium fusion reaction). The fusion takes place under bombardment of a deuterium- (or tritium-) saturated target by a high-current (about 100 mA) focused deuterium ion beam with an energy of 100 keV. The ion beam with total current at a level of hundreds of milliamperes and small emittance (less than 0.1 π·mm·mrad), which is crucial for sharp focusing, can be generated by a quasi-gas-dynamic ion source of a new generation created on the basis of a discharge in an open magnetic trap sustained by high-power electromagnetic radiation of the millimeter wavelength range under electron cyclotron resonance conditions. Simulations of the focusing system for the experimentally obtained ion beam show the possibility to create a deuterium ion beam with a transverse size of 200 μm on the neutron-forming target. Prospects for using such a neutron source for neutron tomography are discussed.

Development and characterization of a high-reliability, extended-lifetime H- ion source

NASA Astrophysics Data System (ADS)

Becerra, Gabriel; Barrows, Preston; Sherman, Joseph

2015-11-01

Phoenix Nuclear Labs (PNL) has designed and constructed a long-lifetime, negative hydrogen (H-) ion source, in partnership with Fermilab for an ion beam injector servicing future Intensity Frontier particle accelerators. The specifications for the low-energy beam transport (LEBT) section are 5-10 mA of continuous H- ion current at 30 keV with <0.2 π-mm-mrad emittance. Existing ion sources at Fermilab rely on plasma-facing electrodes, limiting their lifetime to a few hundred hours, while requiring relatively high gas loads on downstream components. PNL's design features an electron cyclotron resonance (ECR) microwave plasma driver which has been extensively developed in positive ion source systems, having demonstrated 1000+ hours of operation and >99% continuous uptime at PNL. Positive ions and hyperthermal neutrals drift toward a low-work-function surface, where a fraction is converted into H- hydrogen ions, which are subsequently extracted into a low-energy beam using electrostatic lenses. A magnetic filter preferentially removes high-energy electrons emitted by the source plasma, in order to mitigate H- ion destruction via electron-impact detachment. The design of the source subsystems and preliminary diagnostic results will be presented.

Plasma parameter diagnosis using hydrogen emission spectra of a quartz-chamber 2.45 GHz ECRIS at Peking University

NASA Astrophysics Data System (ADS)

Wu, WenBin; Ren, HaiTao; Peng, ShiXiang; Xu, Yuan; Wen, JiaMei; Zhang, Tao; Zhang, JingFeng; Zhang, AiLin; Sun, Jiang; Guo, ZhiYu; Chen, JiaEr

2018-04-01

A quartz-chamber 2.45 GHz electron cyclotron resonance ion source (ECRIS) was designed for diagnostic purposes at Peking University [Patent Number: ZL 201110026605.4]. This ion source can produce a maximum 84 mA hydrogen ion beam at 50 kV with a duty factor of 10%. The root-mean-square (RMS) emittance of this beam is less than 0.12π mm mrad. In our initial work, the electron temperature and electron density inside the plasma chamber had been measured with the line intensity ratio of noble gases. Based on these results, the atomic and molecular emission spectra of hydrogen were applied to determine the dissociation degree of hydrogen and the vibrational temperature of hydrogen molecules in the ground state, respectively. Measurements were performed at gas pressures from 4×10-4 to 1×10-3 Pa and at input peak RF power ranging from 1000 to 1800 W. The dissociation degree of hydrogen in the range of 0.5%-10% and the vibrational temperature of hydrogen molecules in the ground state in the range of 3500-8500 K were obtained. The plasma processes inside this ECRIS chamber were discussed based on these results.

Scattering effects in passive foil focusing of ion beams

DOE PAGES

Yuen, Albert; Lund, Steven M.; Barnard, John J.; ...

2015-09-11

A stack of thin, closely spaced conducting foils has been investigated by Lund et al. [ Phys. Rev. ST Accel. Beams 16, 044202 (2013)] as a passive focusing lens for intense ion beams. The foils mitigate space-charge defocusing forces to enable the beam self-magnetic field to focus. In this study, we analyze possible degradation of focusing due to scattering of beam ions resulting from finite foil thickness using an envelope model and numerical simulations with the particle-in-cell code WARP. Ranges of kinetic energy where scattering effects are sufficient to destroy passive focusing are quantified. The scheme may be utilized tomore » focus protons produced in intense laser-solid accelerator schemes. The spot size of an initially collimated 30 MeV proton beam with initial rms radius 200 μm, perveance Q=1.8×10 -2, and initial transverse emittance ϵ x,rms=0.87 mm mrad propagating through a stack of 6.4 μm thick foils, spaced 100 μm apart, gives a 127.5 μm spot with scattering and a 81.0 μm spot without scattering, illustrating the importance of including scattering effects.« less

The new IR and THz FEL facility at the Fritz Haber Institute in Berlin

NASA Astrophysics Data System (ADS)

Schöllkopf, Wieland; Gewinner, Sandy; Junkes, Heinz; Paarmann, Alexander; von Helden, Gert; Bluem, Hans P.; Todd, Alan M. M.

2015-05-01

A mid-infrared oscillator FEL has been commissioned at the Fritz Haber Institute. The accelerator consists of a thermionic gridded gun, a subharmonic buncher, and two S-band standing-wave copper structures. It provides a final electron energy adjustable from 15 to 50 MeV, low longitudinal (< 50 keV ps) and transverse emittance (< 20 πmm mrad), at more than 200 pC bunch charge with a micro-pulse repetition rate of 1 GHz and a macro-pulse length of up to 15 µs. Pulsed radiation with up to 100 mJ macro-pulse energy at about 0.5% FWHM bandwidth is routinely produced in the wavelength range from 4 to 48 µm. A characterization of the FEL performance in terms of pulse energy, bandwidth, and micro-pulse shape of the IR radiation is given. In addition, selected user results are presented. These include, for instance, spectroscopy of bio-molecules (peptides and small proteins) either conformer selected by ion mobility spectrometry or embedded in superfluid helium nano-droplets at 0.4 K, as well as vibrational spectroscopy of mass-selected metal-oxide clusters and protonated water clusters in the gas phase.

Recent optimization of the beam-optical characteristics of the 6 MV van de Graaff accelerator for high brightness beams at the iThemba LABS NMP facility

NASA Astrophysics Data System (ADS)

Conradie, J. L.; Eisa, M. E. M.; Celliers, P. J.; Delsink, J. L. G.; Fourie, D. T.; de Villiers, J. G.; Maine, P. M.; Springhorn, K. A.; Pineda-Vargas, C. A.

2005-04-01

With the aim of improving the reliability and stability of the beams delivered to the nuclear microprobe at iThemba LABS, as well as optimization of the beam characteristics along the van de Graaff accelerator beamlines in general, relevant modifications were implemented since the beginning of 2003. The design and layout of the beamlines were revised. The beam-optical characteristics through the accelerator, from the ion source up to the analysing magnet directly after the accelerator, were calculated and the design optimised, using the computer codes TRANSPORT, IGUN and TOSCA. The ion source characteristics and optimal operating conditions were determined on an ion source test bench. The measured optimal emittance for 90% of the beam intensity was about 50π mm mrad for an extraction voltage of 6 kV. These changes allow operation of the Nuclear Microprobe at proton energies in the range 1 MeV-4 MeV with beam intensities of tenths of a pA at the target surface. The capabilities of the nuclear microprobe facility were evaluated in the improved beamline, with particular emphasis to bio-medical samples.

Visible high power fiber coupled diode lasers

NASA Astrophysics Data System (ADS)

Köhler, Bernd; Drovs, Simon; Stoiber, Michael; Dürsch, Sascha; Kissel, Heiko; Könning, Tobias; Biesenbach, Jens; König, Harald; Lell, Alfred; Stojetz, Bernhard; Löffler, Andreas; Strauß, Uwe

2018-02-01

In this paper we report on further development of fiber coupled high-power diode lasers in the visible spectral range. New visible laser modules presented in this paper include the use of multi single emitter arrays @ 450 nm leading to a 120 W fiber coupled unit with a beam quality of 44 mm x mrad, as well as very compact modules with multi-W output power from 405 nm to 640 nm. However, as these lasers are based on single emitters, power scaling quickly leads to bulky laser units with a lot of optical components to be aligned. We also report on a new approach based on 450 nm diode laser bars, which dramatically reduces size and alignment effort. These activities were performed within the German government-funded project "BlauLas": a maximum output power of 80 W per bar has been demonstrated @ 450 nm. We show results of a 200 μm NA0.22 fiber coupled 35 W source @ 450 nm, which has been reduced in size by a factor of 25 compared to standard single emitter approach. In addition, we will present a 200 μm NA0.22 fiber coupled laser unit with an output power of 135 W.

Enhanced laser radiation pressure acceleration of protons with a gold cone-capillary

NASA Astrophysics Data System (ADS)

Lv, Chong; Xie, Bai-Song; Wan, Feng; Hou, Ya-Juan; Jia, Mo-Ran; Sang, Hai-Bo; Hong, Xue-Ren; Liu, Shi-Bing

2017-03-01

A scheme with a gold cone-capillary is proposed to improve the protons acceleration, and involved problems are investigated by using the two-dimensional particle-in-cell simulations. It is demonstrated that the cone-capillary can efficiently guide and collimate the protons to a longer distance and result in a better beam quality with a dense density ≥ 10 n c , monoenergetic peak energy E k ˜ 1.51 GeV , spatial emittance ˜ 0.0088 mm mrad with divergence angle θ ˜ 1.0 ° and diameter ˜ 0.5 μ m . The enhancement is mainly attributed to the focusing effect by the transverse electric field generated by the cone as well as the capillary, which can prevent greatly the protons from expanding in the transverse direction. Comparable to without the capillary, the protons energy spectra have a stable monoenergetic peak and divergence angle nearby 1.0 ° in longer time. Besides, the efficiency of acceleration depending on the capillary length is explored, and the optimal capillary length is also achieved. Such a target may be beneficial to many applications such as ion fast ignition in inertial fusion, proton therapy and so on.

Ion Source Development at the SNS

NASA Astrophysics Data System (ADS)

Welton, R. F.; Stockli, M. P.; Murray, S. N.; Carr, J.; Carmichael, J.; Goulding, R. H.; Baity, F. W.

2007-08-01

The US Spallation Neutron Source (SNS) has recently begun producing neutrons and is currently on track to becoming a world-leading facility for material science based on neutron scattering. The facility is comprised of an H- ion source, a linear accelerator, an accumulator ring, a liquid-Hg target and a suite of neutron scattering instruments. Over the next several years the average H- current from the ion source will be increased in order to meet the baseline facility requirement of providing 1.4 MW of beam-power to the target and the SNS power upgrade power requirement of 2+ MW on target. Meeting the latter goal will require H- currents of 70-100 mA with an RMS emittance of 0.20-0.35 π mm mrad and a ˜7% duty-factor. To date, the RF-driven-multicusp SNS ion source has only been able to demonstrate sustained operation at 33 mA of beam current at a ˜7% duty-factor. This report details our efforts to develop variations of the current ion source which can meet these requirements. Designs and experimental results are presented for helicon plasma drivers, high-power external antennas, glow-discharge plasma guns and advanced Cs systems.

High-speed laser-launched flyer impacts studied with ultrafast photography and velocimetry

DOE PAGES

Banishev, Alexandr A.; Shaw, William L.; Bassett, Will P.; ...

2016-02-16

Pulsed lasers can launch thin metal foils at km s -1, but for precision measurements in shock compression science and shock wave spectroscopy, where one-dimensional shock compression is vital, flyer plate impacts with targets must have a high degree of flatness and minimal tilt, and the flyer speeds and impact times at the target must be highly reproducible. We have developed an apparatus that combines ultrafast stroboscopic optical microscopy with photon Doppler velocimetry to study impacts of laser-launched Al and Cu flyer plates with flat, transparent glass targets. The flyer plates were 0.5 mm in diameter, and ranged from 12-100more » μm thick, with flyer speeds up to 6.25 km s -1. The velocity variations over 30-60 launches from the same flyer plate optic can be as low as 0.6%, and the impact time variations can be as low as 0.8 ns. Stroboscopic image streams (reconstructed movies) show uniform, flat impacts with a glass target. As a result, these stroboscopic images can be used to estimate the tilt in the flyer-target impact to be <1mrad.« less

A study of the effect of in-line and perpendicular magnetic fields on beam characteristics of electron guns in medical linear accelerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Constantin, Dragos E.; Fahrig, Rebecca; Keall, Paul J.

Purpose: Using magnetic resonance imaging (MRI) for real-time guidance during radiotherapy is an active area of research and development. One aspect of the problem is the influence of the MRI scanner, modeled here as an external magnetic field, on the medical linear accelerator (linac) components. The present work characterizes the behavior of two medical linac electron guns with external magnetic fields for in-line and perpendicular orientations of the linac with respect to the MRI scanner. Methods: Two electron guns, Litton L-2087 and Varian VTC6364, are considered as representative models for this study. Emphasis was placed on the in-line design approachmore » in which case the MRI scanner and the linac axes of symmetry coincide and assumes no magnetic shielding of the linac. For the in-line case, the magnetic field from a 0.5 T open MRI (GE Signa SP) magnet with a 60 cm gap between its poles was computed and used in full three dimensional (3D) space charge simulations, whereas for the perpendicular case the magnetic field was constant. Results: For the in-line configuration, it is shown that the electron beam is not deflected from the axis of symmetry of the gun and the primary beam current does not vanish even at very high values of the magnetic field, e.g., 0.16 T. As the field strength increases, the primary beam current has an initial plateau of constant value after which its value decreases to a minimum corresponding to a field strength of approximately 0.06 T. After the minimum is reached, the current starts to increase slowly. For the case when the beam current computation is performed at the beam waist position the initial plateau ends at 0.016 T for Litton L-2087 and at 0.012 T for Varian VTC6364. The minimum value of the primary beam current is 27.5% of the initial value for Litton L-2087 and 22.9% of the initial value for Varian VTC6364. The minimum current is reached at 0.06 and 0.062 T for Litton L-2087 and Varian VTC6364, respectively. At 0.16 T the beam current increases to 40.2 and 31.4% from the original value of the current for Litton L-2087 and Varian VTC6364, respectively. In contrast, for the case when the electron gun is perpendicular to the magnetic field, the electron beam is deflected from the axis of symmetry even at small values of the magnetic field. As the strength of the magnetic field increases, so does the beam deflection, leading to a sharp decrease of the primary beam current which vanishes at about 0.007 T for Litton L-2087 and at 0.006 T for Varian VTC6364, respectively. At zero external field, the beam rms emittance computed at beam waist is 1.54 and 1.29{pi}-mm-mrad for Litton L-2087 and Varian VTC6364, respectively. For the in-line configuration, there are two particular values of the external field where the beam rms emittance reaches a minimum. Litton L-2087 rms emittance reaches a minimum of 0.72{pi} and 2.01{pi}-mm-mrad at 0.026 and 0.132 T, respectively. Varian VTC6364 rms emittance reaches a minimum of 0.34{pi} and 0.35{pi}-mm-mrad at 0.028 and 0.14 T, respectively. Beam radius dependence on the external field is shown for the in-line configuration for both electron guns. Conclusions: 3D space charge simulation of two electron guns, Litton L-2087 and Varian VTC6364, were performed for in-line and perpendicular external magnetic fields. A consistent behavior of Pierce guns in external magnetic fields was proven. For the in-line configuration, the primary beam current does not vanish but a large reduction of beam current (up to 77.1%) is observed at higher field strengths; the beam directionality remains unchanged. It was shown that for a perpendicular configuration the current vanishes due to beam bending under the action of the Lorentz force. For in-line configuration it was determined that the rms beam emittance reaches two minima for relatively high values of the external magnetic field.« less

Strength of mortar containing rubber tire particle

NASA Astrophysics Data System (ADS)

Jusoh, M. A.; Abdullah, S. R.; Adnan, S. H.

2018-04-01

The main focus in this investigation is to determine the strength consist compressive and tensile strength of mortar containing rubber tire particle. In fact, from the previous study, the strength of mortar containing waste rubber tire in mortar has a slightly decreases compare to normal mortar. In this study, rubber tire particle was replacing on volume of fine aggregate with 6%. 9% and 12%. The sample were indicated M0 (0%), M6 (6%), M9 (9%) and M12 (12%). In this study, two different size of sample used with cube 100mm x 100mm x 100mm for compressive strength and 40mm x 40mm x 160mm for flexural strength. Morphology test was conducted by using Scanning electron microscopic (SEM) were done after testing compressive strength test. The concrete sample were cured for day 3, 7 and 28 before testing. Results compressive strength and flexural strength of rubber mortar shown improved compare to normal mortar.

Intrahepatic and hilar mass-forming cholangiocarcinoma: Qualitative and quantitative evaluation with diffusion-weighted MR imaging.

PubMed

Fattach, Hassan El; Dohan, Anthony; Guerrache, Youcef; Dautry, Raphael; Boudiaf, Mourad; Hoeffel, Christine; Soyer, Philippe

2015-08-01

To qualitatively and quantitatively analyze the presentation of intrahepatic and hilar mass-forming cholangiocarcinoma with diffusion-weighted magnetic resonance imaging (DW-MRI). Twenty-eight patients with histopathologically proven mass-forming cholangiocarcinoma (hilar, n=17; intrahepatic, n=11) underwent hepatic DW-MRI at 1.5-T using free-breathing acquisition and three b-values (0,400,800s/mm(2)). Cholangiocarcinomas were evaluated qualitatively using visual analysis of DW-MR images and quantitatively with conventional ADC and normalized ADC measurements using liver and spleen as reference organs. All cholangiocarcinomas (28/28; 100%) were visible on DW-MR images. DW-MRI yielded best conspicuity of cholangiocarcinomas than the other MRI sequences (P<0.001). Seven cholangiocarcinomas (7/11; 64%) showed hypointense central area on DW-MR images. Conventional ADC value of cholangiocarcinomas (1.042×10(-3)mm(2)/s±0.221×10(-3)mm(2)/s; range: 0.616×10(-3)mm(2)/s to 2.050×10(-3)mm(2)/s) was significantly lower than that of apparently normal hepatic parenchyma (1.362×10(-3)mm(2)/s±0.187×10(-3)mm(2)/s) (P<0.0001), although substantial overlap was found. No significant differences in ADC and normalized ADC values were found between intrahepatic and hilar cholangiocarcinomas. The use of normalized ADC using the liver as reference organ resulted in the most restricted distribution of ADC values of cholangiocarcinomas (variation coefficient=16.6%). There is a trend towards a common appearance of intrahepatic and hilar mass-forming cholangiocarcinomas on DW-MRI but variations may be observed. Familiarity with these variations may improve the diagnosis of mass-forming cholangiocarcinoma. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Mean Normal Portal Vein Diameter Using Sonography among Clients Coming to Radiology Department of Jimma University Hospital, Southwest Ethiopia.

PubMed

Geleto, Gemechu; Getnet, Wondim; Tewelde, Tsegaye

2016-05-01

Mean portal vein diameter is considered as the best indicator for portal hypertension. However, the cutoff point differs from study to study (above 10-15 mm) despite the existence of normal mean portal vein diameter between 10-15 mm in different settings.This implies the existence of limited evidence on normal portal vein diameter for all populations in all countries prior to setting the cutoff points. Therefore, the aim of this study was sonographic assessment of normal mean portal vein diameter among patients referred to The Department of Radiology in Jimma University Hospital. A facility based cross-sectional study was conducted from November to December 2014 at Jimma University Hospital on a total of 195 clients. Data about portal vein diameter for eligible clients were collected by radiologists using Sonography. Data were edited manually, entered and analyzed using SPSS version 16. Data were collected from a total of 195 participants. Among these, 121(62.1%) were males and the median age of the participants was 35 years. The study revealed a normal mean portal vein diameter of 10.6 mm ±1.8 SD with a respirophasic variation of 25.6%. Likewise, the normal mean portal vein diameter seemed to have varied significantly by age and sex. The study revealed a normal mean portal vein diameter ranging below 13 mm. Hence, decisions made in clinical settings should base on these findings. Besides, there is a need for large scale study to determine portal vein diameter variation by age and sex, controlling other confounders.

Could linear MRI measurements of hippocampus differentiate normal brain aging in elderly persons from Alzheimer disease?

PubMed

Tarroun, Abdullah; Bonnefoy, Marc; Bouffard-Vercelli, Juliette; Gedeon, Claire; Vallee, Bernard; Cotton, François

2007-02-01

Although mild progressive specific structural brain changes are commonly associated with normal human aging, it is unclear whether automatic or manual measurements of these structures can differentiate normal brain aging in elderly persons from patients suffering from cognitive impairment. The objective of this study was primarily to define, with a standard high resolution MRI, the range of normal linear age-specific values for the hippocampal formation (HF), and secondarily to differentiate hippocampal atrophy in normal aging from that occurring in Alzheimer disease (AD). Two MRI-based linear measurements of the hippocampal formation at the level of the head and of the tail, standardized by the cranial dimensions, were obtained from coronal and sagittal T1-weighted MR images in 25 normal elderly subjects, and 26 patients with AD. In this study, dimensions of the HF have been standardized and they revealed normal distributions for each side and each sex: the width of the hippocampal head at the level of the amygdala was 16.42 +/- 1.9 mm, and its height 7.93 +/- 1.4 mm; the width of the tail at the level of the cerebral aqueduct was 8.54 +/- 1.2 mm, and the height 5.74 +/- 0.4 mm. There were no significant differences in standardized dimensions of the HF between sides, sexes, or in comparison to head dimensions in the two groups. In addition, the median inter-observer agreement index was 93%. In contrast, the dimensions of the hippocampal formation decreased gradually with increasing age, owing to physiological atrophy, but this atrophy is more significant in the group of AD.

Feasibility of novel four degrees of freedom capacitive force sensor for skin interface force

PubMed Central

2012-01-01

Background The objective of our study was to develop a novel capacitive force sensor that enables simultaneous measurements of yaw torque around the pressure axis and normal force and shear forces at a single point for the purpose of elucidating pressure ulcer pathogenesis and establishing criteria for selection of cushions and mattresses. Methods Two newly developed sensors (approximately 10 mm×10 mm×5 mm (10) and 20 mm×20 mm×5 mm (20)) were constructed from silicone gel and four upper and lower electrodes. The upper and lower electrodes had sixteen combinations that had the function as capacitors of parallel plate type. The full scale (FS) ranges of force/torque were defined as 0–1.5 N, –0.5-0.5 N and −1.5-1.5 N mm (10) and 0–8.7 N, –2.9-2.9 N and −16.8-16.8 N mm (20) in normal force, shear forces and yaw torque, respectively. The capacitances of sixteen capacitors were measured by an LCR meter (AC1V, 100 kHz) when displacements corresponding to four degrees of freedom (DOF) forces within FS ranges were applied to the sensor. The measurement was repeated three times in each displacement condition (10 only). Force/torque were calculated by corrected capacitance and were evaluated by comparison to theoretical values and standard normal force measured by an universal tester. Results In measurements of capacitance, the coefficient of variation was 3.23% (10). The Maximum FS errors of estimated force/torque were less than or equal to 10.1 (10) and 16.4% (20), respectively. The standard normal forces were approximately 1.5 (10) and 9.4 N (20) when pressure displacements were 3 (10) and 2 mm (20), respectively. The estimated normal forces were approximately 1.5 (10) and 8.6 N (10) in the same condition. Conclusions In this study, we developed a new four DOF force sensor for measurement of force/torque that occur between the skin and a mattress. In measurement of capacitance, the repeatability was good and it was confirmed that the sensor had characteristics that enabled the correction by linear approximation for adjustment of gain and offset. In estimation of forces/torque, we considered accuracy to be within an acceptable range. PMID:23186069

Emittance measurements for optimum operation of the J-PARC RF-driven H{sup −} ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ueno, A., E-mail: akira.ueno@j-parc.jp; Ohkoshi, K.; Ikegami, K.

2015-04-08

In order to satisfy the Japan Proton Accelerator Research Complex (J-PARC) second stage requirements of an H{sup −} ion beam of 60mA within normalized emittances of 1.5πmm•mrad both horizontally and vertically, a flat top beam duty factor of 1.25% (500μs×25Hz) and a life-time of longer than 1month, the J-PARC cesiated RF-driven H{sup −} ion source was developed by using an internal-antenna developed at the Spallation Neutron Source (SNS). The transverse emittances of the source were measured with various conditions to find out the optimum operation conditions minimizing the horizontal and vertical rms normalized emittances. The transverse emittances were most effectivelymore » reduced by operating the source with the plasma electrode temperature lower than 70°C. The optimum value of the cesium (Cs) density around the beam hole of the plasma electrode seems to be proportional to the plasma electrode temperature. The fine control of the Cs density is indispensable, since the emittances seem to increase proportionally to the excessiveness of the Cs density. Furthermore, the source should be operated with the Cs density beyond a threshold value, since the plasma meniscus shape and the ellipse parameters of the transverse emittances seem to be changed step-function-likely on the threshold Cs value.« less

Laser-launched flyer plate and confined laser ablation for shock wave loading: validation and applications.

PubMed

Paisley, Dennis L; Luo, Sheng-Nian; Greenfield, Scott R; Koskelo, Aaron C

2008-02-01

We present validation and some applications of two laser-driven shock wave loading techniques: laser-launched flyer plate and confined laser ablation. We characterize the flyer plate during flight and the dynamically loaded target with temporally and spatially resolved diagnostics. With transient imaging displacement interferometry, we demonstrate that the planarity (bow and tilt) of the loading induced by a spatially shaped laser pulse is within 2-7 mrad (with an average of 4+/-1 mrad), similar to that in conventional techniques including gas gun loading. Plasma heating of target is negligible, in particular, when a plasma shield is adopted. For flyer plate loading, supported shock waves can be achieved. Temporal shaping of the drive pulse in confined laser ablation allows for flexible loading, e.g., quasi-isentropic, Taylor-wave, and off-Hugoniot loading. These techniques can be utilized to investigate such dynamic responses of materials as Hugoniot elastic limit, plasticity, spall, shock roughness, equation of state, phase transition, and metallurgical characteristics of shock-recovered samples.

Multimode laser beam analyzer instrument using electrically programmable optics.

PubMed

Marraccini, Philip J; Riza, Nabeel A

2011-12-01

Presented is a novel design of a multimode laser beam analyzer using a digital micromirror device (DMD) and an electronically controlled variable focus lens (ECVFL) that serve as the digital and analog agile optics, respectively. The proposed analyzer is a broadband laser characterization instrument that uses the agile optics to smartly direct light to the required point photodetectors to enable beam measurements of minimum beam waist size, minimum waist location, divergence, and the beam propagation parameter M(2). Experimental results successfully demonstrate these measurements for a 500 mW multimode test laser beam with a wavelength of 532 nm. The minimum beam waist, divergence, and M(2) experimental results for the test laser are found to be 257.61 μm, 2.103 mrad, 1.600 and 326.67 μm, 2.682 mrad, 2.587 for the vertical and horizontal directions, respectively. These measurements are compared to a traditional scan method and the results of the beam waist are found to be within error tolerance of the demonstrated instrument.

Emittance measurements in Grumman 1 MeV beamline

DOE Office of Scientific and Technical Information (OSTI.GOV)

Debiak, T.; Gammel, G.; Melnychuk, S.

1992-12-01

The emittance of a 30 keV H{sup {minus}} beam has been measured with an Allison type electrostatic analyser at two positions separated by 85 cm along the Grumman 1 MeV beamline LEBT at low currents (about 4 mA, no Cs{sub 2}O additive in the source) and at higher currents (10-15 mA, with Cs{sub 2}O additive in the source). No emittance growth was observed between the two positions, but, at the higher current level, the emittance was about 60% higher than at the low current level ({Sigma}{sub n},rms = .0045 {pi} cm-mrad vs. 0070 {pi} cm-mrad). Argon was then introduced upmore » to a partial pressure of 4x10{sup {minus}5} torr, and the emittance decreased back to a range corresponding to that found at the lower currents. However, beam noise was observed at the downstream position, and there is evidence for a small amount of emittance growth (<20%) between the two positions.« less

Synthesis and $gamma$-irradiation of verbenone and verbenol

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kulesza, J.; Tsankova, E.; Gora, J.

1972-01-01

Verbenone and verbenol which can be obtained by catalytic oxidation of $alpha$-pinene, are very useful for the perfumery industry. They can be used directly in perfume compositions or for the production of a number of other perfumery synthetics. The authors have attempted to transform verbenol and verbenone into other compounds by gamma irradiation. It was found, that verbenone exhibits resistance to the gamma irradiation and even at the doses of 500 Mrad it was only with small yield transformed in chrysantenone. The gamma irradiation of cis and trans verbenol by the doses of 220 Mrad has showed no change inmore » the case of trans isomer, and on the other hand the cis isomer was transformed mainly into trans verbenol and verbenone. The results of the investigation of the conditions having influence on the yield and the composition of the reaction products in the process of the catalytic oxidizing of $alpha$- pinene are given. (auth)« less

Precise and long-term stabilization of the carrier-envelope phase of femtosecond laser pulses using an enhanced direct locking technique.

PubMed

Yu, Tae Jun; Hong, Kyung-Han; Choi, Hyun-Gyug; Sung, Jae Hee; Choi, Il Woo; Ko, Do-Kyeong; Lee, Jongmin; Kim, Junwon; Kim, Dong Eon; Nam, Chang Hee

2007-06-25

We demonstrate a long-term operation with reduced phase noise in the carrier-envelope-phase (CEP) stabilization process by employing a double feedback loop and an improved signal detection in the direct locking technique [Opt. Express 13, 2969 (2005)]. A homodyne balanced detection method is employed for efficiently suppressing the dc noise in the f-2f beat signal, which is converted into the CEP noise in the direct locking loop working at around zero carrier-envelope offset frequency (f(ceo)). In order to enhance the long-term stability, we have used the double feedback scheme that modulates both the oscillator pump power for a fast control and the intracavity-prism insertion depth for a slow and high-dynamic-range control. As a result, the in-loop phase jitter is reduced from 50 mrad of the previous result to 29 mrad, corresponding to 13 as in time scale, and the long-term stable operation is achieved for more than 12 hours.

Investigating Degradation Mechanisms in 130 nm and 90 nm Commercial CMOS Technologies Under Extreme Radiation Conditions

NASA Astrophysics Data System (ADS)

Ratti, Lodovico; Gaioni, Luigi; Manghisoni, Massimo; Traversi, Gianluca; Pantano, Devis

2008-08-01

The purpose of this paper is to study the mechanisms underlying performance degradation in 130 nm and 90 nm commercial CMOS technologies exposed to high doses of ionizing radiation. The investigation has been mainly focused on their noise properties in view of applications to the design of low-noise, low-power analog circuits to be operated in harsh environment. Experimental data support the hypothesis that charge trapping in shallow trench isolation (STI), besides degrading the static characteristics of interdigitated NMOS transistors, also affects their noise performances in a substantial fashion. The model discussed in this paper, presented in a previous work focused on CMOS devices irradiated with a 10 Mrad(SiO2) gamma -ray dose, has been applied here also to transistors exposed to much higher (up to 100 Mrad(SiO2 )) doses of X-rays. Such a model is able to account for the extent of the observed noise degradation as a function of the device polarity, dimensions and operating point.

Phase compensation with fiber optic surface profile acquisition and reconstruction system

NASA Astrophysics Data System (ADS)

Bo, En; Duan, Fajie; Feng, Fan; Lv, Changrong; Xiao, Fu; Huang, Tingting

2015-02-01

A fiber-optic sinusoidal phase modulating (SPM) interferometer was proposed for the acquisition and reconstruction of three-dimensional (3-D) surface profile. Sinusoidal phase modulation was induced by controlling the injection current of light source. The surface profile was constructed on the basis of fringe projection. Fringe patterns are vulnerable to external disturbances such as mechanical vibration and temperature fluctuation, which cause phase drift in the interference signal and decrease measuring accuracy. A closed-loop feedback phase compensation system was built. In the subsystem, the initial phase of the interference signal, which was caused by the initial optical path difference between interference arms, could be demodulated using phase generated carrier (PGC) method and counted out using coordinated rotation digital computer (CORDIC) , then a compensation voltage was generated for the PZT driver. The bias value of external disturbances superimposed on fringe patterns could be reduced to about 50 mrad, and the phase stability for interference fringes was less than 6 mrad. The feasibility for real-time profile measurement has been verified.

Quantitative analysis of rectal cancer by spectral domain optical coherence tomography

NASA Astrophysics Data System (ADS)

Zhang, Q. Q.; Wu, X. J.; Tang, T.; Zhu, S. W.; Yao, Q.; Gao, Bruce Z.; Yuan, X. C.

2012-08-01

To quantify OCT images of rectal tissue for clinic diagnosis, the scattering coefficient of the tissue is extracted by curve fitting the OCT signals to a confocal single model. A total of 1000 measurements (half and half of normal and malignant tissues) were obtained from 16 recta. The normal rectal tissue has a larger scattering coefficient ranging from 1.09 to 5.41 mm-1 with a mean value of 2.29 mm-1 (std:±0.32), while the malignant group shows lower scattering property and the values ranging from 0.25 to 2.69 mm-1 with a mean value of 1.41 mm-1 (std:±0.18). The peri-cancer of recta has also been investigated to distinguish the difference between normal and malignant rectal tissue. The results demonstrate that the quantitative analysis of the rectal tissue can be used as a promising diagnostic criterion of early rectal cancer, which has great value for clinical medical applications.

Magnetic Resonance Imaging Determination of Normal Pituitary Gland Dimensions in Zaria, Northwest Nigerian Population

PubMed Central

Ibinaiye, Philip Oluleke; Olarinoye-Akorede, Sefia; Kajogbola, Olugbenga; Bakari, Adamu Girei

2015-01-01

Objectives: To determine the dimensions of normal pituitary gland using T1-weighted magnetic resonance images (MRI) and to determine their relationship with age and sex. Materials and Methods: Cranial MRI scans of 100 individuals with clinically normal pituitary function (58 males and 42 females) and in the age range 14–82 years were reviewed in order to obtain volumetric measurements of the pituitary gland. The height, width, and depth of the pituitary were obtained from mid-sagittal and coronal planes, while the volume was calculated from these measured parameters. The data obtained were stratified based on age and sex for analysis. Statistical tests applied included Student's t-test and Pearson correlation. A minimum level of statistical significance was set at P < 0.05. Results: The mean pituitary volumes were 334.1 ± 145.8 mm3 and 328.1 ± 129.2 mm3 while the mean pituitary heights were 6.45 ± 1.7 mm and 6.46 ± 1.57 mm in males and females, respectively. Although there was no statistically significant difference between pituitary height and pituitary volume in both sexes, they correlated negatively with increasing age (r = −202, P = 0.04 and r = −410, P = 0.000, respectively). Both parameters were highest in pubertal subjects and declined steadily with age, with a second peak occurring only for pituitary height in the sixth decade. The mean pituitary widths (9.08 ± 2.59 mm and 9.21 ± 1.86 mm) and depths (10.59 ± 1.71 mm and 10.49 ± 1.57 mm) in males and females, respectively, did not show remarkable changes with age and sex in the individuals studied. Conclusion: With this study, we have provided reference values in Nigerian population for the dimensions of normal pituitary gland, in order to facilitate assessment and diagnosis in patients with abnormalities of the hypothalamic–pituitary axis. PMID:26167387

High b Value (2,000 s/mm2) Diffusion-Weighted Magnetic Resonance Imaging in Prostate Cancer at 3 Tesla: Comparison with 1,000 s/mm2 for Tumor Conspicuity and Discrimination of Aggressiveness

PubMed Central

Tamada, Tsutomu; Kanomata, Naoki; Sone, Teruki; Jo, Yoshimasa; Miyaji, Yoshiyuki; Higashi, Hiroki; Yamamoto, Akira; Ito, Katsuyoshi

2014-01-01

Objective The objective of our study was to investigate tumor conspicuity and the discrimination potential for tumor aggressiveness on diffusion-weighted magnetic resonance imaging (DW-MRI) with high b value at 3-T. Materials and Methods The institutional review board approved this study and waived the requirement for informed consent. A total of 50 patients with prostate cancer (69 cancer foci; 48 in the PZ, 20 in the TZ, and one in whole prostate) who underwent multiparametric prostate MRI including DW-MRI (b values: 0, 1000 s/mm2 and 0, 2000 s/mm2) on a 3-T system were included. Lesion conspicuity score (LCS) using visual assessment (1 = invisible for surrounding normal site; 2 = slightly high intensity; 3 = moderately high; and 4 = very high) and tumor-normal signal intensity ratio (TNR) were assessed, and apparent diffusion coefficient (ADC, ×10−3 mm2/s) of the tumor regions and normal regions were measured. Results Mean LCS and TNR at 0, 2000 s/mm2 was significantly higher than those at 0, 1000 s/mm2 (p<0.001 for both). In addition, ADC at both 0, 1000 and 0, 2000 s/mm2 was found to distinguish intermediate or high risk cancer with Gleason score ≥7 from low risk cancer with Gleason score ≤6 (p<0.001 for both). Furthermore, ADC of tumor regions correlated with Gleason score at both 0, 1000 s/mm2 (ρ = −0.602; p<0.001) and 0, 2000 s/mm2 (ρ = −0.645; p<0.001). Conclusions For tumor conspicuity and characterization of prostate cancer on DW-MRI of 3-T MRI, b = 0, 2000 s/mm2 is more useful than b = 0, 1000 s/mm2. PMID:24802652

High b value (2,000 s/mm2) diffusion-weighted magnetic resonance imaging in prostate cancer at 3 Tesla: comparison with 1,000 s/mm2 for tumor conspicuity and discrimination of aggressiveness.

PubMed

Tamada, Tsutomu; Kanomata, Naoki; Sone, Teruki; Jo, Yoshimasa; Miyaji, Yoshiyuki; Higashi, Hiroki; Yamamoto, Akira; Ito, Katsuyoshi

2014-01-01

The objective of our study was to investigate tumor conspicuity and the discrimination potential for tumor aggressiveness on diffusion-weighted magnetic resonance imaging (DW-MRI) with high b value at 3-T. The institutional review board approved this study and waived the requirement for informed consent. A total of 50 patients with prostate cancer (69 cancer foci; 48 in the PZ, 20 in the TZ, and one in whole prostate) who underwent multiparametric prostate MRI including DW-MRI (b values: 0, 1000 s/mm2 and 0, 2000 s/mm2) on a 3-T system were included. Lesion conspicuity score (LCS) using visual assessment (1 = invisible for surrounding normal site; 2 = slightly high intensity; 3 = moderately high; and 4 = very high) and tumor-normal signal intensity ratio (TNR) were assessed, and apparent diffusion coefficient (ADC, ×10-3 mm2/s) of the tumor regions and normal regions were measured. Mean LCS and TNR at 0, 2000 s/mm2 was significantly higher than those at 0, 1000 s/mm2 (p<0.001 for both). In addition, ADC at both 0, 1000 and 0, 2000 s/mm2 was found to distinguish intermediate or high risk cancer with Gleason score ≥7 from low risk cancer with Gleason score ≤6 (p<0.001 for both). Furthermore, ADC of tumor regions correlated with Gleason score at both 0, 1000 s/mm2 (ρ = -0.602; p<0.001) and 0, 2000 s/mm2 (ρ = -0.645; p<0.001). For tumor conspicuity and characterization of prostate cancer on DW-MRI of 3-T MRI, b = 0, 2000 s/mm2 is more useful than b = 0, 1000 s/mm2.

Total Antioxidant Status in Type 2 Diabetic Patients in Palestine.

PubMed

Kharroubi, Akram T; Darwish, Hisham M; Akkawi, Mutaz A; Ashareef, Abdelkareem A; Almasri, Zaher A; Bader, Khaldoun A; Khammash, Umaiyeh M

2015-01-01

The objective of this study was to compare the level of total antioxidant status (TAS) in type 2 diabetic and normal Palestinian subjects as well as the major factors influencing TAS levels. A sample of convenience composed of 212 type 2 diabetic and 208 normal subjects above the age of 40 were recruited. Only 9.8% of the subjects had normal body mass index (BMI) levels (<25), 29% were overweight (≥25 to <30), and 61.2% were obese (≥30). The mean levels of TAS were significantly higher in diabetic compared to control subjects (2.18 versus 1.84 mM Trolox, P = 0.001) and in hypertensive subjects compared to subjects with normal blood pressure (BP). Mean TAS levels were higher in obese compared to nonobese subjects (2.12 versus 1.85 mM Trolox, P = 0.001). Mean TAS levels were similarly higher in subjects with high fasting plasma glucose (FPG) compared to normal FPG (2.19 versus 1.90 mM Trolox) and high HbA1c (≥6.5%) compared to HbA1c < 6.5% (2.14 versus 1.91 mM Trolox). Multivariate analysis revealed that only diabetic status (P = 0.032) and the level of education (P = 0.036) were significantly associated with TAS. In conclusion diabetic patients had 18.5% increase in TAS levels compared to control subjects.

AlN/GaN heterostructures for normally-off transistors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhuravlev, K. S., E-mail: zhur@isp.nsc.ru; Malin, T. V.; Mansurov, V. G.

The structure of AlN/GaN heterostructures with an ultrathin AlN barrier is calculated for normally-off transistors. The molecular-beam epitaxy technology of in situ passivated SiN/AlN/GaN heterostructures with a two-dimensional electron gas is developed. Normally-off transistors with a maximum current density of ~1 A/mm, a saturation voltage of 1 V, a transconductance of 350 mS/mm, and a breakdown voltage of more than 60 V are demonstrated. Gate lag and drain lag effects are almost lacking in these transistors.

Auditory steady-state responses to MM and exponential envelope AM(2)/FM stimuli in normal-hearing adults.

PubMed

D'haenens, Wendy; Dhooge, Ingeborg; De Vel, Eddy; Maes, Leen; Bockstael, Annelies; Vinck, Bart M

2007-08-01

The present study utilized a commercially available multiple auditory steady-state response (ASSR) system to test normal hearing adults (n=55). The primary objective was to evaluate the impact of the mixed modulation (MM) and the novel proposed exponential AM(2)/FM stimuli on the signal-to-noise ratio (SNR) and threshold estimation accuracy, through a within-subject comparison. The second aim was to establish a normative database for both stimulus types. The results demonstrated that the AM(2)/FM and MM stimulus had a similar effect on the SNR, whereas the ASSR threshold results revealed that the AM(2)/FM produced better thresholds than the MM stimulus for the 500, 1000, and 4000 Hz carrier frequency. The mean difference scores to tones of 500, 1000, 2000, and 4000 Hz were for the MM stimulus: 20+/-12, 14+/-9, 10+/-8, and 12+/-8 dB; and for the AM(2)/FM stimulus: 18+/-13, 12+/-8, 11+/-8, and 10+/-8 dB, respectively. The current research confirms that the AM(2)/FM stimulus can be used efficiently to test normal hearing adults.

Comparison of axial length, anterior chamber depth and intraocular lens power between IOLMaster and ultrasound in normal, long and short eyes.

PubMed

Dong, Jing; Zhang, Yaqin; Zhang, Haining; Jia, Zhijie; Zhang, Suhua; Wang, Xiaogang

2018-01-01

To compare the axial length (AL), anterior chamber depth (ACD) and intraocular lens power (IOLP) of IOLMaster and Ultrasound in normal, long and short eyes. Seventy-four normal eyes (≥ 22 mm and ≤ 25 mm), 74 long eyes (> 25 mm) and 78 short eyes (< 22 mm) underwent AL and ACD measurements with both devices in the order of IOLMaster followed by Ultrasound. The IOLP were calculated using a free online LADAS IOL formula calculator. The difference in AL and IOLP between IOLMaster and Ultrasound was statistically significant when all three groups were combined. The difference in ACD between IOLMaster and Ultrasound was statistically significant in the normal group (P<0.001) and short eye group (P<0.001) but not the long eye group (P = 0.465). For the IOLP difference between IOLMaster and Ultrasound in the normal group, the percentage of IOLP differences <|0.5|D, ≥|0.5|D<|0.75|D, ≥|0.75|D<|1.0|D, and ≥|1.0|D were 90.5%, 8.1%, 1.4% and 0%, respectively. For the long eye group, they were 90.5%, 5.4%, 4.1% and 0%, respectively. For the short eye group, they were 61.5%, 23.1%, 10.3%, and 5.1%, respectively. IOLMaster and Ultrasound have statistically significant differences in AL measurements and IOLP (using LADAS formula) for normal, long eye and short eye. The two instruments agree regarding ACD measurements for the long eye group, but differ for the normal and short eye groups. Moreover, the high percentage of IOLP differences greater than |0.5|D in the short eye group is noteworthy.

SU-E-T-647: Quality Assurance of VMAT by Gamma Analysis Dependence On Low-Dose Threshold

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, J; Kim, M; Lee, S

2015-06-15

Purpose: The AAPM TG-119 instructed institutions to use low-dose threshold (LDT) of 10% or a ROI determined by the jaw when they collected gamma analysis QA data of planar dose distribution. Also, based on a survey by Nelms and Simon, more than 70% of institutions use a LDT between 0% and 10% for gamma analysis. However, there are no clinical data to quantitatively demonstrate the impact of the LDT on the gamma index. Therefore, we performed a gamma analysis with LDTs of 0% to 15% according to both global and local normalization and different acceptance criteria: 3%/3 mm, 2%/2 mm,more » and 1%/1 mm. Methods: A total of 30 treatment plans—10 head and neck, 10 brain, and 10 prostate cancer cases—were randomly selected from the Varian Eclipse TPS, retrospectively. For the gamma analysis, a predicted portal image was acquired through a portal dose calculation algorithm in the Eclipse TPS, and a measured portal image was obtained using a Varian Clinac iX and an EPID. Then, the gamma analysis was performed using the Portal Dosimetry software. Results: For the global normalization, the gamma passing rate (%GP) decreased as the LDT increased, and all cases of low-dose thresholds exhibited a %GP above 95% for both the 3%/3 mm and 2%/2 mm criteria. However, for local normalization, the %GP increased as LDT increased. The gamma passing rate with LDT of 10% increased by 6.86%, 9.22% and 6.14% compared with the 0% in the case of the head and neck, brain and prostate for 3%/3 mm criteria, respectively. Conclusion: Applying the LDT in the global normalization does not have critical impact to judge patient-specific QA results. However, LDT for the local normalization should be carefully selected because applying the LDT could affect the average of the %GP to increase rapidly.« less

[Imaging evaluation on adaptability of proximal humeral anatomy after shoulder replacement with individualized shoulder prosthesis].

PubMed

Shi, Youxing; Tang, Kanglai; Yuan, Chengsong; Tao, Xu; Wang, Huaqing; Chen, Bo; Guo, Yupeng

2015-03-24

Modern shoulder prosthesis has evolved through four generations. And the fourth generation technology has a core three-dimensional design of restoring 3D reconstruction of proximal humeral anatomy. Thus a new shoulder prosthesis is developed on the basis of the technology of 3D prosthesis. Assessment of whether shoulder prosthesis can restore individualized reconstruction of proximal humeral anatomy is based on the adaptability of proximal humeral anatomy. To evaluate the adaptability of proximal humeral anatomy through measuring the parameters of proximal humeral anatomy after shoulder replacement with individualized shoulder prosthesis and compare with normal data. The parameters of proximal humeral anatomy were analyzed and evaluated for a total of 12 cases undergoing shoulder replacement with individualized shoulder prosthesis. The relevant anatomical parameters included neck-shaft angle (NSA), retroversion angle (RA), humeral head height (HH) and humeral head diameter (HD). And the anatomical parameters were compared with the data from normal side. All underwent shoulder replacement with individualized shoulder prosthesis. The postoperative parameters of proximal humeral anatomy were compared with those of normal side. And the difference of NSA was < 3°, RA < 3°, HH < 3 mm and HD < 2 mm. And paired-sample t test was used to study the parameters of proximal humeral anatomy between postoperative and normal side. The normal and postoperative NSA was (140.2 ± 6.8)° and (139.5 ± 6.6)° respectively, RA (34.4 ± 3.3)° and (33.8-3.1)°, HH (15.3 ± 2.1) mm and (14.6+0.9) mm, HW (42.2 ± 2.82) mm and (41.8 ± 2.33) mm respectively. No significant difference existed between two groups (P > 0.05). Individualized shoulder prosthesis has excellent adaptability to shoulder. All core parameters are freely adjustable and specification models may be optimized. With matching tools, individualized shoulder prosthesis improves the accuracy and reliability in shoulder replacement.

The haemodynamic effects of intravenous paracetamol (acetaminophen) in healthy volunteers: a double‐blind, randomized, triple crossover trial

PubMed Central

Chiam, Elizabeth; Bailey, Michael; McNicol, Larry; Bellomo, Rinaldo

2016-01-01

Aim The haemodynamic effects of intravenous paracetamol have not been systematically investigated. We compared the physiological effects of intravenous mannitol‐containing paracetamol, and an equivalent dosage of mannitol, and normal saline 0.9% in healthy volunteers. Methods We performed a blinded, triple crossover, randomized trial of 24 adult healthy volunteers. Participants received i.v. paracetamol (1 g paracetamol +3.91 g mannitol 100 ml–1), i.v. mannitol (3.91 g mannitol 100 ml–1) and i.v. normal saline (100 ml). Composite primary end points were changes in mean arterial pressure (MAP), systolic blood pressure (SBP) and diastolic blood pressure (DBP) measured pre‐infusion, during a 15 min infusion period and over a 45 min observation period. Systemic vascular resistance index (SVRI) and cardiac index were measured at the same time points. Results Infusion of paracetamol induced a transient yet significant decrease in blood pressures from pre‐infusion values (MAP –1.85 mmHg, 95% CI –2.6, –1.1, SBP –0.54 mmHg, 95% CI –1.7, 0.6 and DBP −1.92 mmHg, 95% CI –2.6, –1.2, P < 0.0001), associated with a transient reduction in SVRI and an increase in cardiac index. Changes were observed, but to a lesser extent with normal saline (MAP –0.15 mmHg, SBP +1.44 mmHg, DBP −–0.73 mmHg, P < 0.0001), but not with mannitol (MAP +1.47 mmHg, SBP +4.03 mmHg, DBP +0.48 mmHg, P < 0.0001). Conclusions I.v. paracetamol caused a transient decrease in blood pressure immediately after infusion. These effects were not seen with mannitol or normal saline. The physiological mechanism was consistent with vasodilatation. This study provides plausible physiological data in a healthy volunteer setting, supporting transient changes in haemodynamic variables with i.v. paracetamol and justifies controlled studies in the peri‐operative and critical care setting. PMID:26606263

The haemodynamic effects of intravenous paracetamol (acetaminophen) in healthy volunteers: a double-blind, randomized, triple crossover trial.

PubMed

Chiam, Elizabeth; Weinberg, Laurence; Bailey, Michael; McNicol, Larry; Bellomo, Rinaldo

2016-04-01

The haemodynamic effects of intravenous paracetamol have not been systematically investigated. We compared the physiological effects of intravenous mannitol-containing paracetamol, and an equivalent dosage of mannitol, and normal saline 0.9% in healthy volunteers. We performed a blinded, triple crossover, randomized trial of 24 adult healthy volunteers. Participants received i.v. paracetamol (1 g paracetamol +3.91 g mannitol 100 ml(-1) ), i.v. mannitol (3.91 g mannitol 100 ml(-1) ) and i.v. normal saline (100 ml). Composite primary end points were changes in mean arterial pressure (MAP), systolic blood pressure (SBP) and diastolic blood pressure (DBP) measured pre-infusion, during a 15 min infusion period and over a 45 min observation period. Systemic vascular resistance index (SVRI) and cardiac index were measured at the same time points. Infusion of paracetamol induced a transient yet significant decrease in blood pressures from pre-infusion values (MAP -1.85 mmHg, 95% CI -2.6, -1.1, SBP -0.54 mmHg, 95% CI -1.7, 0.6 and DBP -1.92 mmHg, 95% CI -2.6, -1.2, P < 0.0001), associated with a transient reduction in SVRI and an increase in cardiac index. Changes were observed, but to a lesser extent with normal saline (MAP -0.15 mmHg, SBP +1.44 mmHg, DBP --0.73 mmHg, P < 0.0001), but not with mannitol (MAP +1.47 mmHg, SBP +4.03 mmHg, DBP +0.48 mmHg, P < 0.0001). I.v. paracetamol caused a transient decrease in blood pressure immediately after infusion. These effects were not seen with mannitol or normal saline. The physiological mechanism was consistent with vasodilatation. This study provides plausible physiological data in a healthy volunteer setting, supporting transient changes in haemodynamic variables with i.v. paracetamol and justifies controlled studies in the peri-operative and critical care setting. © 2015 The British Pharmacological Society.

The SuperCam Remote Sensing Suite for MARS 2020: Nested and Co-Aligned LIBS, Raman, and VISIR Spectroscopies, and color micro-imaging

NASA Astrophysics Data System (ADS)

Fouchet, Thierry; Wiens, Roger; Maurice, Sylvestre; Johnson, Jeffrey R.; Clegg, Samuel; Sharma, Shiv; Rull, Fernando; Montmessin, Franck; Anderson, Ryan; Beyssac, Olivier; Bonal, Lydie; Deflores, Lauren; Dromart, Gilles; Fischer, William; Forni, Olivier; Gasnault, Olivier; Grotzinger, John P.; Mangold, Nicolas; Martinez-Frias, Jesus; MacLennan, Scott; McCabe, Kevin; cais, Philippe; Nelson, Tony; Angel, Stanley; Beck, Pierre; Benzerara, Karim; Bernard, Sylvain; Bousquet, Bruno; Bridges, Nathan; Cloutis, Edward; Fabre, Cécile; Grasset, Olivier; Lanza, Nina; Lasue, Jeremie; Le Mouélic, Stéphane; Leveille, Rich; Lewin, Eric; McConnochie, Timothy H.; Melikechi, Noureddine; Meslin, Pierre-Yves; Misra, Anupam; Montagnac, Gilles; Newsom, Horton; Ollila, Ann; Pinet, Patrick; Poulet, Francois; Sobron, Pablo

2016-10-01

As chartered by the Science Definition Team, the Mars 2020 mission addresses four primary objectives: A. Characterize the processes that formed and modified the geologic record within an astrobiologically relevant ancient environment, B. Perform astrobiologically relevant investigations to determine habitability, search for materials with biosignature presentation potential, and search for evidence of past life, C. Assemble a returnable cache of samples and D. Contribute to preparation for human exploration of Mars. The SuperCam instrument, selected for the Mars 2020 rover, as a suite of four instruments, provides nested and co-aligned remote investigations: Laser Induced Breakdown Spectroscopy (LIBS), Raman spectroscopy and time-resolved fluorescence (TRF), visible and near-infrared spectroscopy (VISIR), and high resolution color imaging (RMI). SuperCam appeals broadly to the four Mars 2020 objectives.In detail, SuperCam will perform:1. Microscale mineral identification by combining LIBS elemental and VISIR mineralogical spectroscopies, especially targeting secondary minerals2. Determine the sedimental stratigraphy through color imaging and LIBS and VISIR spectroscopy3. Search for organics and bio-signatures with LIBS and Raman spectroscopy4. Quantify the volatile content of the rocks by LIBS spectroscopy to determine the degree of aquaeous alteration5. Characterize the texture of the rocks by color imaging to determine their alteration processes6. Characterize the rocks' coatings by LIBS spectroscopy7. Characterize the soil and its potential for biosignature preservation8. Monitor the odd-oxygen atmospheric chemistry.To meet these goals SuperCam will perform LIBS spectroscopy on 0.5 mm spot up to 7-meter distance, perform Raman and time-resolved fluoresence up to 12-m distance with a 0.8 mrad angular resolution, a 100 ns time gating in the 534-850 nm spectral range, acquire VISIR spectra in the range 0.4-0.85 μm with a resolution of 0.35 nm, and in the IR range over 1.3-2.6 μm, rich in mineral signatures, with a resolution of 20 nm, and provide RGB images with an angular resolution of 40 μrad over a FOV of 20 mrad.We will present the science performances of SuperCam and the forecasted operation plans.

New Energy-Dependent Soft X-Rav Damage In MOS Devices

NASA Astrophysics Data System (ADS)

Chan, Tung-Yi; Gaw, Henry; Seligson, Daniel; Pan, Lawrence; King, Paul L.; Pianetta, Piero

1988-06-01

An energy-dependent soft x-ray-induced device damage has been discovered in MOS devices fabricated using standard CMOS process. MOS devices were irradiated by monochromatic x-rays in energy range just above and below the silicon K-edge (1.84 keV). Photons below the K-edge is found to create more damage in the oxide and oxide/silicon interface than photons above the K-edge. This energy-dependent damage effect is believed to be due to charge traps generated during device fabrication. It is found that data for both n- and p-type devices lie along a universal curve if normalized threshold voltage shifts are plotted against absorbed dose in the oxide. The threshold voltage shift saturates when the absorbed dose in the oxide exceeds 1.4X105 mJ/cm3, corresponding to 6 Mrad in the oxide. Using isochronal anneals, the trapped charge damage is found to recover with an activation energy of 0.38 eV. A discrete radiation-induced damage state appears in the low frequency C-V curve in a temperature range from 1750C to 325°C.

Apparent diffusion coefficient in the analysis of prostate cancer: determination of optimal b-value pair to differentiate normal from malignant tissue.

PubMed

Adubeiro, Nuno; Nogueira, Maria Luísa; Nunes, Rita G; Ferreira, Hugo Alexandre; Ribeiro, Eduardo; La Fuente, José Maria Ferreira

Determining optimal b-value pair for differentiation between normal and prostate cancer (PCa) tissues. Forty-three patients with diagnosis or PCa symptoms were included. Apparent diffusion coefficient (ADC) was estimated using minimum and maximum b-values of 0, 50, 100, 150, 200, 500s/mm2 and 500, 800, 1100, 1400, 1700 and 2000s/mm2, respectively. Diagnostic performances were evaluated when Area-under-the-curve (AUC)>95%. 15 of the 35 b-values pair surpassed this AUC threshold. The pair (50, 2000s/mm2) provided the highest AUC (96%) with ADC cutoff 0.89×10- 3 mm 2 /s, sensitivity 95.5%, specificity 93.2% and accuracy 94.4%. The best b-value pair was b=50, 2000s/mm2. Copyright © 2017 Elsevier Inc. All rights reserved.

The cam impinging femur has multiple morphologic abnormalities.

PubMed

Ellis, Andrew R; Noble, Philip C; Schroder, Steven J; Thompson, Matthew T; Stocks, Gregory W

2011-09-01

This study was performed to establish whether the "cam" impinging femur has a single deformity of the head-neck junction or multiple abnormalities. Average dimensions (anteversion angle, α angle of Notzli, β angle of Beaulé, normalized anterior head offset) were compared between normal and impinging femora. The results demonstrated that impinging femora had wider necks, larger heads, and decreased head-neck ratios. There was no difference in neck-shaft angle or anteversion angle. Forty-six percent of impinging femora had significant posterior head displacement (>2mm), which averaged 1.93 mm for the cam impinging group, and 0.78 mm for the normal group. In conclusion, surgical treatment limited to localized recontouring of the head-neck profile may fail to address significant components of the underlying abnormality. Copyright © 2011 Elsevier Inc. All rights reserved.

Echocardiographic assessment by computer-assisted analysis of diastolic left ventricular function and hypertrophy in borderline or mild systemic hypertension.

PubMed

Papademetriou, V; Gottdiener, J S; Fletcher, R D; Freis, E D

1985-09-15

Systemic hypertension is a common cause of congestive heart failure. However, left ventricular (LV) systolic function remains normal for many years in patients with mild or moderate hypertension. In this study, high-quality M-mode echocardiograms were recorded in 7 patients with borderline hypertension, 14 patients with mild hypertension and 15 normal persons. Measures of systolic and diastolic LV function and the degree of LV hypertrophy were studied with the assistance of a tablet digitizer and dedicated microcomputer. Average blood pressure was 125 +/- 10/77 +/- 7 mm Hg in normal subjects, 146 +/- 18/92 +/- 2 mm Hg in patients with borderline hypertension and 150 +/- 11/102 +/- 4 in patients with mild hypertension. Indexes of systolic LV function were similar in all 3 groups. The peak rate of early relaxation of the LV posterior wall was significantly decreased in the group of patients with mild hypertension (4.7 vs 6.6 sec-1, p less than 0.01). The mitral valve closure rate was 150 +/- 32 mm/s in normal subjects, 119 +/- 35 mm/s in patients with borderline hypertension and 106 +/- 26 mm/s (p less than 0.001) in patients with mild hypertension. Mild LV hypertrophy was present in 6 of 7 patients with borderline and 13 of 14 patients with mild hypertension. The degree of hypertrophy and the level of blood pressure correlated poorly.(ABSTRACT TRUNCATED AT 250 WORDS)

The mesangial matrix in the normal and sclerotic glomerulus.

PubMed

Rosenblum, N D

1994-02-01

Mesangial sclerosis is a final common pathway to glomerular destruction in a variety of glomerular diseases. The expression of several classes of extracellular matrix (ECM) molecules has been defined in the normal and diseased mesangial matrix (MM). However, the manner in which these ECM components determine the three dimensional structure and function of the MM remains to be defined. Structural studies of the MM suggest that its constituent molecules are regionally organized into subcompartments with different three dimensional structures. The diversity of matrix molecules expressed within the MM as well as the organization of these components in nonrenal ECM's, such as the cornea, provides further support for this organizational model. The study of the cornea has also revealed that novel short chain collagenous proteins partially determine the three dimensional structure of the matrix. Recently, a novel collagen, type VIII collagen, has been described in mesangial cells and in the intact glomerulus. It is hypothesized that type VIII collagen is expressed both as a polymer and as a monomer within the glomerulus, and depending on its conformation, may serve unique functions. In the chronically diseased MM, normal MM components are overexpressed and fibrillar collagens are expressed de novo in a delayed fashion. Enhanced proteoglycan expression, observed early in disease, may determine increased volume of the mesangium. This, in turn, may stimulate the production of fibrillar collagens by mesangial cells resulting in a fibrillar noncompliant mesangial matrix.

Frequency of postnatal hydronephrosis in infants with a renal anterior-posterior pelvic diameter > 4 mm on midtrimester ultrasound.

PubMed

Chou, Ching-Yu; Chen, Li-Ching; Cheong, Mei-Leng; Tsai, Ming-Song

2015-10-01

To examine the association of antenatal renal pelvic dilatation observed on midtrimester ultrasound screening with the presence of hydronephrosis in newborn infants. The records of patients who received fetal ultrasound examination at 18-28 weeks' gestation from May 2008 to March 2012 were retrospectively reviewed. A fetal renal pelvic anterior-posterior (AP) diameter > 4 mm was considered abnormal and ≤ 4 mm was considered normal. On postnatal ultrasound, a renal pelvic AP diameter > 3 mm was considered to indicate hydronephrosis and ≤ 3 mm was considered normal. The association of postnatal hydronephrosis with prenatal pelvic AP diameter was determined using binary logistic regression analysis. The study comprised 1310 newborn infants: 684 (52.2%) male and 626 (47.8%) female. Multivariate analysis showed a right or left prenatal AP renal pelvic diameter > 4 mm was associated with a higher risk of postnatal hydronephrosis compared with a right and left prenatal AP renal pelvic diameter ≤ 4 mm. Boys had a higher risk for postnatal hydronephrosis than girls (odds ratio = 2.42, p < 0.05). An antenatal renal pelvic AP diameter > 4 mm on midtrimester ultrasound is predictive of postnatal hydronephrosis. Copyright © 2015. Published by Elsevier B.V.

Factors significantly increasing or inhibiting early stages of malignant melanoma (M.M.) and non-invasive evaluation of new treatment by ingestion and external application of optimal doses of the most effective anti-M.M. substances: haritaki, cilantro, vitamin D3, nori, EPA with DHA, & application of special (+) solar energy stored paper, which reduced the M.M. active area & asbestos rapidly.

PubMed

Omura, Yoshiaki; Jones, Marilyn; Duvvi, Harsha; Paluch, Kamila; Shimotsuura, Yasuhiro; Ohki, Motomu

2013-01-01

Sterilizing the pre-cancer skin of malignant melanoma (M.M.) with 70% Isopropyl alcohol intensified malignancy & the malignant response extended to surrounding normal looking skin, while sterilizing with 80% (vodka) or 12% (plum wine) ethyl alcohol completely inhibited M.M. in the area (both effects lasted for about 90 minutes initially). Burnt food (bread, vegetables, meat, and fish), a variety of smoked & non-smoked fish-skin, many animal's skin, pepper, Vitamin C over 75 mg, mango, pineapple, coconut, almond, sugars, Saccharine & Aspartame, garlic, onion, etc & Electromagnetic field from cellular phones worsened M.M. & induced abnormal M.M. response of surrounding skin. We found the following factors inhibit early stage of M.M. significantly: 1) Increasing normal cell telomere, by taking 500 mg Haritaki, often reached between 400-1150 ng& gradually diminished, but the M.M. response was completely inhibited until normal cell telomeres are reduced to 150 ng, which takes 6-8 hours. More than 70 mg Vitamin C, Orange Juice, & other high Vitamin C containing substances shouldn't be taken because they completely inhibit the effects of Haritaki. 2) We found Chrysotile asbestos & Tremolite asbestos (% of the Chrysotile amount) coexist. A special Cilantro tablet was used to remove asbestos & some toxic metals. 3) Vitamin D3 400 I.U. has a maximum inhibiting effect on M.M. but 800 I.U. or higher promotes malignancy. 4) Noricontaining Iodine, etc., was used. 5) EPA 180 mm with DHA 120 mg was most effectively used after metastasis to the surrounding skin was eliminated. When we combined 1 Cilantro tablet & Vitamin D3 400 I.U. withsmall Nori pieces & EPA with DHA, the effect of complete inhibition of M.M. lasted 9-11 hours. When these anti-M.M.substances (Haritaki, Vitamin D3, Cilantro, Nori, EPA. with DHA) were taken together, the effect lasted 12-14 hoursand M.M. involvement in surrounding normal-looking skin disappeared rapidly & original dark brown or black are as satisfying "ABCD" of M.M. completely fell off. Both oral & frequent external application of mixed solution of plum wine & the same combination of anti-M.M. substances can be used as very effective treatment by taking 2-3 times daily. Additional application of special (+) Solar Energy Stored Paper reduced asbestos & accelerated reduction of M.M. positive area rapidly. This method with individualized optimal doses has also been successfully applied to treat several other types of malignancies.

Effects of 0.2% brimonidine and 0.2% brimonidine-0.5% timolol on intraocular pressure and pupil size in normal equine eyes.

PubMed

Von Zup, M; Lassaline, M; Kass, P H; Miller, P E; Thomasy, S M

2017-11-01

Brimonidine is an α 2 -adrenergic agonist that decreases aqueous humour production and may increase uveoscleral outflow. It has not been evaluated in normal or glaucomatous equine eyes. To evaluate the efficacy and safety of brimonidine in lowering intraocular pressure (IOP), alone and in conjunction with timolol, as a treatment for equine glaucoma by comparing IOP in normal equine eyes treated with brimonidine and brimonidine-timolol, respectively, with IOP in control eyes. A balanced crossover design with 16 horses receiving one of two treatments, brimonidine and brimonidine-timolol, during each of two 10-day study phases, was used. Four horses were randomly assigned to each of four combinations of treated eye (right or left) and drug order within the two 10-day study phases (brimonidine first or brimonidine-timolol first). Pupil size and conjunctival hyperaemia were assessed twice per day and IOP was measured three times per day using rebound tonometry in both eyes of 16 normal horses throughout two 10-day study periods (brimonidine and brimonidine-timolol) separated by an 18-day washout period. One eye of each horse was treated with brimonidine or brimonidine-timolol and the opposite eye was treated with balanced salt solution (BSS). There were no adverse effects and no significant changes in pupil size in normal equine eyes treated with brimonidine or brimonidine-timolol. Average IOP in normal equine eyes treated with brimonidine (25.6 mmHg) was statistically higher than in eyes treated with brimonidine-timolol (24.6 mmHg) or BSS (24.5 mmHg). However, IOP differences were of ≤1 mmHg and thus not clinically important. Horses with normal eyes may not be as sensitive to the IOP-lowering effects of treatment as horses with glaucoma. Brimonidine and brimonidine-timolol are well tolerated in normal horses but do not decrease IOP. © 2017 EVJ Ltd.

Evaluation of the Normal Cochlear Second Interscalar Ridge Angle and Depth on 3D T2-Weighted Images: A Tool for the Diagnosis of Scala Communis and Incomplete Partition Type II.

PubMed

Booth, T N; Wick, C; Clarke, R; Kutz, J W; Medina, M; Gorsage, D; Xi, Y; Isaacson, B

2018-05-01

Cochlear malformations may be be subtle on imaging studies. The purpose of this study was to evaluate the angle and depth of the lateral second interscalar ridge or notch in ears without sensorineural hearing loss (normal ears) and compare them with ears that have a documented incomplete type II partition malformation. The second interscalar ridge notch angle and depth were measured on MR imaging in normal ears by a single experienced neuroradiologist. The images of normal and incomplete partition II malformation ears were then randomly mixed for 2 novice evaluators to measure both the second interscalar ridge notch angle and depth in a blinded manner. For the mixed group, interobserver agreement was calculated, normal and abnormal ear measurements were compared, and receiver operating characteristic curves were generated. The 94 normal ears had a mean second interscalar ridge angle of 80.86° ± 11.4° and depth of 0.54 ± 0.14 mm with the 98th percentile for an angle of 101° and a depth of 0.3 mm. In the mixed group, agreement between the 2 readers was excellent, with significant differences for angle and depth found between normal and incomplete partition type II ears for angle and depth on average ( P < .001). Receiver operating characteristic cutoffs for delineating normal from abnormal ears were similar for both readers (depth, 0.31/0.34 mm; angle, 114°/104°). A measured angle of >114° and a depth of the second interscalar ridge notch of ≤0.31 mm suggest the diagnosis of incomplete partition type II malformation and scala communis. These measurements can be accurately made by novice readers. © 2018 by American Journal of Neuroradiology.

A cutting-edge solution for 1µm laser metal processing

NASA Astrophysics Data System (ADS)

Baumbach, N.; Kühl, P.; Karam, J.; Jonkers, J.; Villarreal-Saucedo, F.; Reyes, M.

2017-02-01

The recent 1μm-laser cutting market is dominated by fiber and disk lasers due to their excellent beam quality of below 4mm*mrad. Teradiode's 4kW direct diode laser source achieves similar beam quality while having a different beam shape and shorter wavelengths which are known for higher absorption rates at the inclined front of the cutting keyhole. Research projects, such as the HALO Project, have additionally shown that polarized radiation and beams with shapes different from the typical LG00 lead to improved cut quality for ferrous and non-ferrous metals. [1] Diode laser have the inherent property of not being sensitive to back reflection which brings advantages in cutting high-reflective materials. The II-VI HIGHYAG laser cutting head BIMO-FSC offers the unique feature of machine controlled and continuous adjustment of both the focus diameter and the focus position. This feature is proven to be beneficial for cutting and piercing with high speed and small hole diameters. In addition, the optics are designed for lowest focus shift. As a leading laser processing head manufacturer, II-VI HIGHYAG qualified its BIMO-FSC MZ (M=magnification, Z=focus position) cutting head for Teradiode's 4kW direct diode laser source to offer a cutting-edge solution for highpower laser cutting. Combining the magnification ability of the cutting head with this laser source, customers experience strong advantages in cutting metals in broad thickness ranges. Thicknesses up to 25mm mild steel can easily be cut with excellent edge quality. Furthermore, a new optical setup equivalent to an axicon with a variable axicon angle is demonstrated which generates variable sized ring spots. The setup provides new degrees of freedom to tailor the energy distribution for even higher productivity and quality.

The Mars Science Laboratory (MSL) Mast cameras and Descent imager: Investigation and instrument descriptions

NASA Astrophysics Data System (ADS)

Malin, Michal C.; Ravine, Michael A.; Caplinger, Michael A.; Tony Ghaemi, F.; Schaffner, Jacob A.; Maki, Justin N.; Bell, James F.; Cameron, James F.; Dietrich, William E.; Edgett, Kenneth S.; Edwards, Laurence J.; Garvin, James B.; Hallet, Bernard; Herkenhoff, Kenneth E.; Heydari, Ezat; Kah, Linda C.; Lemmon, Mark T.; Minitti, Michelle E.; Olson, Timothy S.; Parker, Timothy J.; Rowland, Scott K.; Schieber, Juergen; Sletten, Ron; Sullivan, Robert J.; Sumner, Dawn Y.; Aileen Yingst, R.; Duston, Brian M.; McNair, Sean; Jensen, Elsa H.

2017-08-01

The Mars Science Laboratory Mast camera and Descent Imager investigations were designed, built, and operated by Malin Space Science Systems of San Diego, CA. They share common electronics and focal plane designs but have different optics. There are two Mastcams of dissimilar focal length. The Mastcam-34 has an f/8, 34 mm focal length lens, and the M-100 an f/10, 100 mm focal length lens. The M-34 field of view is about 20° × 15° with an instantaneous field of view (IFOV) of 218 μrad; the M-100 field of view (FOV) is 6.8° × 5.1° with an IFOV of 74 μrad. The M-34 can focus from 0.5 m to infinity, and the M-100 from 1.6 m to infinity. All three cameras can acquire color images through a Bayer color filter array, and the Mastcams can also acquire images through seven science filters. Images are ≤1600 pixels wide by 1200 pixels tall. The Mastcams, mounted on the 2 m tall Remote Sensing Mast, have a 360° azimuth and 180° elevation field of regard. Mars Descent Imager is fixed-mounted to the bottom left front side of the rover at 66 cm above the surface. Its fixed focus lens is in focus from 2 m to infinity, but out of focus at 66 cm. The f/3 lens has a FOV of 70° by 52° across and along the direction of motion, with an IFOV of 0.76 mrad. All cameras can acquire video at 4 frames/second for full frames or 720p HD at 6 fps. Images can be processed using lossy Joint Photographic Experts Group and predictive lossless compression.

Studies in High Current Density Ion Sources for Heavy Ion Fusion Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chacon-Golcher, Edwin

This dissertation develops diverse research on small (diameter ~ few mm), high current density (J ~ several tens of mA/cm 2) heavy ion sources. The research has been developed in the context of a programmatic interest within the Heavy Ion Fusion (HIF) Program to explore alternative architectures in the beam injection systems that use the merging of small, bright beams. An ion gun was designed and built for these experiments. Results of average current density yield () at different operating conditions are presented for K + and Cs + contact ionization sources and potassium aluminum silicate sources. Maximum valuesmore » for a K + beam of ~90 mA/cm 2 were observed in 2.3 μs pulses. Measurements of beam intensity profiles and emittances are included. Measurements of neutral particle desorption are presented at different operating conditions which lead to a better understanding of the underlying atomic diffusion processes that determine the lifetime of the emitter. Estimates of diffusion times consistent with measurements are presented, as well as estimates of maximum repetition rates achievable. Diverse studies performed on the composition and preparation of alkali aluminosilicate ion sources are also presented. In addition, this work includes preliminary work carried out exploring the viability of an argon plasma ion source and a bismuth metal vapor vacuum arc (MEVVA) ion source. For the former ion source, fast rise-times (~ 1 μs), high current densities (~ 100 mA/cm +) and low operating pressures (< 2 mtorr) were verified. For the latter, high but acceptable levels of beam emittance were measured (ε n ≤ 0.006 π· mm · mrad) although measured currents differed from the desired ones (I ~ 5mA) by about a factor of 10.« less

Testing for Noonan syndrome after increased nuchal translucency.

PubMed

Ali, Marwan M; Chasen, Stephen T; Norton, Mary E

2017-08-01

The aim of this study was to report the prevalence of Noonan syndrome (NS) in a cohort of fetuses that presented with increased nuchal translucency (NT) thickness in the first trimester of pregnancy. This is a retrospective chart review. (1) first trimester NT measurement ≥3 mm, (2) normal karyotype by either a CVS or an amniocentesis procedure, and (3) prenatal molecular genetic testing for NS completed. Results with known pathogenic variants were considered positive, while those with variants of unknown clinical significance, or with no variants, were considered negative. A total of 804 fetuses had an NT measurement of ≥3 mm, with a median NT thickness of 3.6 mm. Of these, 302 had karyotyping by CVS or amniocentesis, 200 (66.23%) with normal results. Of fetuses with a normal karyotype, 39 with a median NT thickness of 4.0 mm had a NS gene sequencing panel done, and 161 fetuses with a mean NT thickness of 4.3 mm were not tested for NS (p = 0.05). Of the 39 fetuses who were tested for NS, four (10.3%) had variants consistent with this diagnosis. In euploid fetuses, increased NT is associated with a 10% risk of NS. © 2017 John Wiley & Sons, Ltd. © 2017 John Wiley & Sons, Ltd.

SU-E-I-25: Quantification of Coronary Artery Cross-Sectional Area in CT Angiography Using Integrated Density: A Simulation Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, T; Ding, H; Lipinski, J

2015-06-15

Purpose: To develop a physics-based model for accurate quantification of the cross-sectional area (CSA) of coronary arteries in CT angiography by measuring the integrated density to account for the partial volume effect. Methods: In this technique the integrated density of the object as compared with its local background is measured to account for the partial volume effect. Normal vessels were simulated as circles with diameters in the range of 0.1–3mm. Diseased vessels were simulated as 2, 3, and 4mm diameter vessels with 10–90% area stenosis, created by inserting circular plaques. A simplified two material model was used with the lumenmore » as 8mg/ml Iodine and background as lipid. The contrast-to-noise ratio between lumen and background was approximately 26. Linear fits to the known CSA were calculated. The precision and accuracy of the measurement were quantified using the root-mean-square fit deviations (RMSD) and errors to the known CSA (RMSE). Results compared to manual segmentation of the vessel lumen. To assess the impact of random variations, coefficients of variation (CV) from 10 simulations for each vessel were computed to determine reliability. Measurements with CVs less than 10% were considered reliable. Results: For normal vessels, the precision and accuracy of the integrated density technique were 0.12mm{sup 2} and 0.28mm{sup 2}, respectively. The corresponding results for manual segmentation were 0.27mm{sup 2} and 0.43mm{sup 2}. For diseased vessels, the precision and accuracy of the integrated density technique were 0.14mm{sup 2} and 0.19mm{sup 2}. Corresponding results for manual segmentation were 0.42mm{sup 2} and 0.71mm{sup 2}. Reliable CSAs were obtained for normal vessels with diameters larger than 1 mm and for diseased vessels with area as low as 1.26mm2. Conclusion: The CSA based on integrated density showed improved precision and accuracy as compared with manual segmentation in simulation. These results indicate the potential of using integrated density to quantify CSA of coronary arteries in CT angiography.« less

A four-tier classification system of pulmonary artery metrics on computed tomography for the diagnosis and prognosis of pulmonary hypertension.

PubMed

Truong, Quynh A; Bhatia, Harpreet Singh; Szymonifka, Jackie; Zhou, Qing; Lavender, Zachary; Waxman, Aaron B; Semigran, Marc J; Malhotra, Rajeev

We aimed to develop a severity classification system of the main pulmonary artery diameter (mPA) and its ratio to the ascending aorta diameter (ratio PA) for the diagnosis and prognosis of pulmonary hypertension (PH) on computed tomography (CT) scans. In 228 patients (136 with PH) undergoing right heart catheterization (RHC) and CT for dyspnea, we measured mPA and ratio PA. In a derivation cohort (n = 114), we determined cutpoints for a four-tier severity grading system that would maximize sensitivity and specificity, and validated it in a separate cohort (n = 114). Cutpoints for mPA were defined with ≤27 mm(F) and ≤29 mm(M) as the normal reference range; mild as >27 to <31 mm(F) and >29 to <31 mm(M); moderate≥31-34 mm; and severe>34 mm. Cutpoints for ratio PA were defined as normal ≤0.9; mild>0.9 to 1.0; moderate>1.0 to 1.1; and severe>1.1. Sensitivities for normal tier were 99% for mPA and 93% for ratio PA; while specificities for severe tier were 98% for mPA>34 mm and 100% for ratio PA>1.1. C-statistics for four-tier mPA and ratio PA were both 0.90 (derivation) and both 0.85 (validation). Severity of mPA and ratio PA corresponded to hemodynamics by RHC and echocardiography (both p < 0.001). Moderate-severe mPA values of ≥31 mm and ratio PA>1.1 had worse survival than normal values (all p ≤ 0.01). A CT-based four-tier severity classification system of PA diameter and its ratio to the aortic diameter has high accuracy for PH diagnosis with increased mortality in patients with moderate-severe severity grades. These results may support clinical utilization on chest and cardiac CT reports. Copyright © 2018 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

Reliability of Pentacam HR Thickness Maps of the Entire Cornea in Normal, Post-Laser In Situ Keratomileusis, and Keratoconus Eyes.

PubMed

Xu, Zhe; Peng, Mei; Jiang, Jun; Yang, Chun; Zhu, Weigen; Lu, Fan; Shen, Meixiao

2016-02-01

To measure the repeatability and reproducibility of Pentacam HR system thickness maps for the entire cornea in normal, post-laser in situ keratomileusis (post-LASIK), and keratoconus (KC) eyes. Reliability study. Sixty normal subjects (60 eyes), 30 post-LASIK subjects (60 eyes), and 14 KC patients (27 eyes) were imaged with the Pentacam HR system by 2 well-trained operators. For pachymetry the cornea was divided into 4 zones: a central zone (2-mm diameter) and concentric pericentral zone (2-5 mm), transitional zone (5-7 mm), and peripheral zone (7-10 mm). The 3 concentric zones were subdivided into 8 sectors. Intraobserver repeatability and interobserver reproducibility of entire corneal thickness maps were tested by the repeatability and reproducibility coefficients, intraclass correlation coefficients, coefficient of variation, and 95% limits of agreement. From central to peripheral zones, the precision of corneal thickness measurements became gradually smaller. Central zone repeatability and reproducibility were the best in the normal, post-LASIK, and KC groups. The peripheral superior sectors showed poorer repeatability and reproducibility for all subjects. The intraobserver repeatability and interobserver reproducibility for all zones were ≤19.3 μm, ≤22.1 μm, and ≤20.7 μm, in the normal, post-LASIK, and KC groups, respectively. The intraobserver and interobserver coefficients of variation for all zones were ≤1.3%, ≤1.6%, and ≤1.6% for all 3 groups. Pentacam HR system pachymetry of the entire cornea provided good precision in normal, post-LASIK, and KC corneas. Thickness measurements in the peripheral cornea should be interpreted with caution in abnormal corneas after surgery or with diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

Statistical assessment of normal mitral annular geometry using automated three-dimensional echocardiographic analysis.

PubMed

Pouch, Alison M; Vergnat, Mathieu; McGarvey, Jeremy R; Ferrari, Giovanni; Jackson, Benjamin M; Sehgal, Chandra M; Yushkevich, Paul A; Gorman, Robert C; Gorman, Joseph H

2014-01-01

The basis of mitral annuloplasty ring design has progressed from qualitative surgical intuition to experimental and theoretical analysis of annular geometry with quantitative imaging techniques. In this work, we present an automated three-dimensional (3D) echocardiographic image analysis method that can be used to statistically assess variability in normal mitral annular geometry to support advancement in annuloplasty ring design. Three-dimensional patient-specific models of the mitral annulus were automatically generated from 3D echocardiographic images acquired from subjects with normal mitral valve structure and function. Geometric annular measurements including annular circumference, annular height, septolateral diameter, intercommissural width, and the annular height to intercommissural width ratio were automatically calculated. A mean 3D annular contour was computed, and principal component analysis was used to evaluate variability in normal annular shape. The following mean ± standard deviations were obtained from 3D echocardiographic image analysis: annular circumference, 107.0 ± 14.6 mm; annular height, 7.6 ± 2.8 mm; septolateral diameter, 28.5 ± 3.7 mm; intercommissural width, 33.0 ± 5.3 mm; and annular height to intercommissural width ratio, 22.7% ± 6.9%. Principal component analysis indicated that shape variability was primarily related to overall annular size, with more subtle variation in the skewness and height of the anterior annular peak, independent of annular diameter. Patient-specific 3D echocardiographic-based modeling of the human mitral valve enables statistical analysis of physiologically normal mitral annular geometry. The tool can potentially lead to the development of a new generation of annuloplasty rings that restore the diseased mitral valve annulus back to a truly normal geometry. Copyright © 2014 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Comparison of vacuum rise time, vacuum limit accuracy, and occlusion break surge of 3 new phacoemulsification systems.

PubMed

Han, Young Keun; Miller, Kevin M

2009-08-01

To compare vacuum rise time, vacuum limit accuracy, and occlusion break surge of 3 new phacoemulsification machines. Jules Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA. The vacuum rise time under normal and enhanced aspiration modes, vacuum limit accuracy, and occlusion break surge of the Infiniti Vision System, Stellaris Vision Enhancement System, and WhiteStar Signature Phacoemulsification System were tested. Vacuum rise time and limit accuracy were measured at limit settings of 400 mm Hg and 600 mm Hg. Surge area was recorded at vacuum limit settings of 200 mm Hg, 300 mm Hg, 400 mm Hg, and 500 mm Hg. The Infiniti had the fastest vacuum rise times under normal and enhanced aspiration modes. At 4 seconds, the vacuum limit accuracy was greatest with the Infiniti at the 400 mm Hg limit and the Signature at the 600 mm Hg limit. The Stellaris did not reach either vacuum target. The Infiniti performed better than the other 2 machines during testing of occlusion break surge at all vacuum limit settings above 200 mm Hg. Under controlled laboratory test conditions, the Infiniti had the fastest vacuum rise time, greatest vacuum limit accuracy at 400 mm Hg, and least occlusion break surge. These results can be explained by the lower compliance of the Infiniti system.

21 CFR 579.40 - Ionizing radiation for the treatment of poultry feed and poultry feed ingredients.

Code of Federal Regulations, 2014 CFR

2014-04-01

..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IRRADIATION IN...Gy (2.5 megarads Mrad). The absorbed dose of irradiation is to be based on initial concentration of... (one decimal reduction). (2) Feeds treated by irradiation should be formulated to account for...

Process for crosslinking methylene-containing aromatic polymers with ionizing radiation

NASA Technical Reports Server (NTRS)

Bell, Vernon L. (Inventor); Havens, Stephen J. (Inventor)

1990-01-01

A process for crosslinking aromatic polymers containing radiation-sensitive methylene groups (-CH2-) by exposing the polymers to ionizing radiation thereby causing crosslinking of the polymers through the methylene groups is described. Crosslinked polymers are resistant to most organic solvents such as acetone, alcohols, hydrocarbons, methylene, chloride, chloroform, and other halogenated hydrocarbons, to common fuels and to hydraulic fluids in contrast to readily soluble uncrosslinked polymers. In addition, the degree of crosslinking of the polymers depends upon the percentage of the connecting groups which are methylene which ranges from 5 to 50 pct and preferably from 25 to 50 pct of the connecting groups, and is also controlled by the level of irradiation which ranges from 25 to 1000 Mrads and preferably from 25 to 250 Mrads. The temperature of the reaction conditions ranges from 25 to 200 C and preferably at or slightly above the glass transition temperature of the polymer. The crosslinked polymers are generally more resistant to degradation at elevated temperatures such as greater than 150 C, have a reduced tendency to creep under load, and show no significant embrittlement of parts fabricated from the polymers.

Carrier-envelope-phase stabilized terawatt class laser at 1 kHz with a wavelength tunable option

DOE PAGES

Langdon, Benjamin; Garlick, Jonathan; Ren, Xiaoming; ...

2015-02-12

We demonstrate a chirped-pulse-amplified Ti:Sapphire laser system operating at 1 kHz, with 20 mJ pulse energy, 26 femtosecond pulse duration (0.77 terawatt), and excellent long term carrier-envelope-phase (CEP) stability. A new vibrational damping technique is implemented to significantly reduce vibrational noise on both the laser stretcher and compressor, thus enabling a single-shot CEP noise value of 250 mrad RMS over 1 hour and 300 mrad RMS over 9 hours. This is, to the best of our knowledge, the best long term CEP noise ever reported for any terawatt class laser. This laser is also used to pump a white-light-seeded opticalmore » parametric amplifier, producing 6 mJ of total energy in the signal and idler with 18 mJ of pumping energy. Due to preservation of the CEP in the white-light generated signal and passive CEP stability in the idler, this laser system promises synthesized laser pulses spanning multi-octaves of bandwidth at an unprecedented energy scale.« less

I12: the Joint Engineering, Environment and Processing (JEEP) beamline at Diamond Light Source.

PubMed

Drakopoulos, Michael; Connolley, Thomas; Reinhard, Christina; Atwood, Robert; Magdysyuk, Oxana; Vo, Nghia; Hart, Michael; Connor, Leigh; Humphreys, Bob; Howell, George; Davies, Steve; Hill, Tim; Wilkin, Guy; Pedersen, Ulrik; Foster, Andrew; De Maio, Nicoletta; Basham, Mark; Yuan, Fajin; Wanelik, Kaz

2015-05-01

I12 is the Joint Engineering, Environmental and Processing (JEEP) beamline, constructed during Phase II of the Diamond Light Source. I12 is located on a short (5 m) straight section of the Diamond storage ring and uses a 4.2 T superconducting wiggler to provide polychromatic and monochromatic X-rays in the energy range 50-150 keV. The beam energy enables good penetration through large or dense samples, combined with a large beam size (1 mrad horizontally × 0.3 mrad vertically). The beam characteristics permit the study of materials and processes inside environmental chambers without unacceptable attenuation of the beam and without the need to use sample sizes which are atypically small for the process under study. X-ray techniques available to users are radiography, tomography, energy-dispersive diffraction, monochromatic and white-beam two-dimensional diffraction/scattering and small-angle X-ray scattering. Since commencing operations in November 2009, I12 has established a broad user community in materials science and processing, chemical processing, biomedical engineering, civil engineering, environmental science, palaeontology and physics.

Mars Exploration Rover engineering cameras

USGS Publications Warehouse

Maki, J.N.; Bell, J.F.; Herkenhoff, K. E.; Squyres, S. W.; Kiely, A.; Klimesh, M.; Schwochert, M.; Litwin, T.; Willson, R.; Johnson, Aaron H.; Maimone, M.; Baumgartner, E.; Collins, A.; Wadsworth, M.; Elliot, S.T.; Dingizian, A.; Brown, D.; Hagerott, E.C.; Scherr, L.; Deen, R.; Alexander, D.; Lorre, J.

2003-01-01

NASA's Mars Exploration Rover (MER) Mission will place a total of 20 cameras (10 per rover) onto the surface of Mars in early 2004. Fourteen of the 20 cameras are designated as engineering cameras and will support the operation of the vehicles on the Martian surface. Images returned from the engineering cameras will also be of significant importance to the scientific community for investigative studies of rock and soil morphology. The Navigation cameras (Navcams, two per rover) are a mast-mounted stereo pair each with a 45?? square field of view (FOV) and an angular resolution of 0.82 milliradians per pixel (mrad/pixel). The Hazard Avoidance cameras (Hazcams, four per rover) are a body-mounted, front- and rear-facing set of stereo pairs, each with a 124?? square FOV and an angular resolution of 2.1 mrad/pixel. The Descent camera (one per rover), mounted to the lander, has a 45?? square FOV and will return images with spatial resolutions of ???4 m/pixel. All of the engineering cameras utilize broadband visible filters and 1024 x 1024 pixel detectors. Copyright 2003 by the American Geophysical Union.

Topological and morphological analysis of gamma rays irradiated chitosan-poly (vinyl alcohol) blends using atomic force microscopy

NASA Astrophysics Data System (ADS)

Bhatt, Rinkesh; Bisen, D. S.; Bajpai, R.; Bajpai, A. K.

2017-04-01

In the present communication, binary blends of poly (vinyl alcohol) (PVA) and chitosan (CS) were prepared by solution cast method and the roughness parameters of PVA, native CS and CS-PVA blend films were determined using atomic force microscopy (AFM). Moreover, the changes in the morphology of the samples were also investigated after irradiation of gamma rays at absorbed dose of 1 Mrad and 10 Mrad for the scanning areas of 5×5 μm2, 10×10 μm2 and 20×20 μm2. Amplitude, statistical and spatial parameters, including line, 3D and 2D image profiles of the experimental surfaces were examined and compared to un-irradiated samples. For gamma irradiated CS-PVA blends the larger waviness over the surface was found as compared to un-irradiated CS-PVA blends but the values of average roughness for both the films were found almost same. The coefficient of skewness was positive for gamma irradiated CS-PVA blends which revealed the presence of more peaks than valleys on the blend surfaces.

Effect of crosslinking UHMWPE on its tensile and compressive creep performance.

PubMed

Lewis, G; Carroll, M

2001-01-01

The in vitro quasi-static tensile and compressive creep properties of three sets of GUR 1050 ultra-high-molecular-weight polyethylene (UHMWPE) specimens were obtained. These sets were: control (as-received stock); "low-gamma" (specimens were crosslinked using gamma radiation, with a minimum dose of 5 Mrad); and "high-gamma" (specimens were crosslinked using gamma radiation, with a minimum dose of 15 Mrad). The % crystallinity (%C) and crosslink density (rho(x)) of the specimens in the three sets were also obtained. It was found that, in both tension and compression, crosslinking resulted in a significant depreciation in the creep properties, relative to control. The trend in the creep results is explained in terms of the impact of crosslinking on the polymer's %C and rho(x). The present results are in contrast to literature reports that show that crosslinking enhances the wear resistance of the polymer. The implications of the present results, taken together with the aforementioned literature results, are fully discussed vis-a-vis the use of crosslinked UHMWPE for fabricating articular components for arthroplasties.

Control of quasi-monoenergetic electron beams from laser-plasma accelerators by adjusting shock density profile

NASA Astrophysics Data System (ADS)

Tsai, Hai-En; Swanson, Kelly K.; Lehe, Remi; Barber, Sam K.; Isono, Fumika; Otero, Jorge G.; Liu, Xinyao; Mao, Hann-Shin; Steinke, Sven; Tilborg, Jeroen Van; Geddes, Cameron G. R.; Leemans, Wim

2017-10-01

High-level control of a laser-plasma accelerator (LPA) using a shock injector was demonstrated by systematically varying the shock injector profile, including the shock angle, up-ramp width and shock position. Particle-in-cell (PIC) simulation explored how variations in the shock profile impacted the injection process and confirmed results obtained through acceleration experiments. These results establish that, by adjusting shock position, up-ramp, and angle, beam energy, energy spread, and pointing can be controlled. As a result, e-beam were highly tunable from 25 to 300 MeV with <8% energy spread, 1.5 mrad divergence and <1 mrad pointing fluctuation. This highly controllable LPA represents an ideal and compact beam source for the ongoing MeV Thomson photon experiments. Set-up and initial experimental design on a newly constructed one hundred TW laser system will be presented. This work is supported by the US DOE under Contract No. DE-AC02-05CH11231, and by the US DOE National Nuclear Security Administration, Defense Nuclear Nonproliferation R&D (NA22).

I12: the Joint Engineering, Environment and Processing (JEEP) beamline at Diamond Light Source

PubMed Central

Drakopoulos, Michael; Connolley, Thomas; Reinhard, Christina; Atwood, Robert; Magdysyuk, Oxana; Vo, Nghia; Hart, Michael; Connor, Leigh; Humphreys, Bob; Howell, George; Davies, Steve; Hill, Tim; Wilkin, Guy; Pedersen, Ulrik; Foster, Andrew; De Maio, Nicoletta; Basham, Mark; Yuan, Fajin; Wanelik, Kaz

2015-01-01

I12 is the Joint Engineering, Environmental and Processing (JEEP) beamline, constructed during Phase II of the Diamond Light Source. I12 is located on a short (5 m) straight section of the Diamond storage ring and uses a 4.2 T superconducting wiggler to provide polychromatic and monochromatic X-rays in the energy range 50–150 keV. The beam energy enables good penetration through large or dense samples, combined with a large beam size (1 mrad horizontally × 0.3 mrad vertically). The beam characteristics permit the study of materials and processes inside environmental chambers without unacceptable attenuation of the beam and without the need to use sample sizes which are atypically small for the process under study. X-ray techniques available to users are radiography, tomography, energy-dispersive diffraction, monochromatic and white-beam two-dimensional diffraction/scattering and small-angle X-ray scattering. Since commencing operations in November 2009, I12 has established a broad user community in materials science and processing, chemical processing, biomedical engineering, civil engineering, environmental science, palaeontology and physics. PMID:25931103

Measurement of xenon diffusing capacity in the rat lung by hyperpolarized 129Xe MRI and dynamic spectroscopy in a single breath-hold.

PubMed

Abdeen, Nishard; Cross, Albert; Cron, Gregory; White, Steven; Rand, Thomas; Miller, David; Santyr, Giles

2006-08-01

We used the dual capability of hyperpolarized 129Xe for spectroscopy and imaging to develop new measures of xenon diffusing capacity in the rat lung that (analogously to the diffusing capacity of carbon monoxide or DLCO) are calculated as a product of total lung volume and gas transfer rate constants divided by the pressure gradient. Under conditions of known constant pressure breath-hold, the volume is measured by hyperpolarized 129Xe MRI, and the transfer rate is measured by dynamic spectroscopy. The new quantities (xenon diffusing capacity in lung parenchyma (DLXeLP)), xenon diffusing capacity in RBCs (DLXeRBC), and total lung xenon diffusing capacity (DLXe)) were measured in six normal rats and six rats with lung inflammation induced by instillation of fungal spores of Stachybotrys chartarum. DLXeLP, DLXeRBC, and DLXe were 56 +/- 10 ml/min/mmHg, 64 +/- 35 ml/min/mmHg, and 29 +/- 9 ml/min/mmHg, respectively, for normal rats, and 27 +/- 9 ml/min/mmHg, 42 +/- 27 ml/min/mmHg, and 16 +/- 7 ml/min/mmHg, respectively, for diseased rats. Lung volumes and gas transfer times for LP (TtrLP) were 16 +/- 2 ml and 22 +/- 3 ms, respectively, for normal rats and 12 +/- 2 ml and 35 +/- 8 ms, respectively, for diseased rats. Xenon diffusing capacities may be useful for measuring changes in gas exchange associated with inflammation and other lung diseases. Copyright 2006 Wiley-Liss, Inc.

Remote detection and recognition of bio-aerosols by laser-induced fluorescense lidar: practical implementation and field tests

NASA Astrophysics Data System (ADS)

Boreysho, Anatoly; Savin, Andrey; Morozov, Alexey; Konyaev, Maxim; Konovalov, Konstantin

2007-06-01

Recognition of aerosol clouds material at some significant distance is now a key requirement for the wide range of applications. The elastic backscatter lidar have demonstrated high capabilities in aerosol remote detection, cloud real-time mapping at very long distances for low-concentration natural aerosols as well as artificial ones [1]. However, recognition ability is required to make them more relevant. Laser-induced fluorescence (LIF) looks very promising with respect to the recognition problem. New approach based on mobile lidar complex [2] equipped by spectrally-and range-resolved LIF-sensor is described as well as some results of field tests. The LIF-sensor consists of four-harmonics Nd:YAG laser equipped by an output expander to provide final beam divergence <1 mrad, 500-mm aspheric Cassegrain-type multi-wavelength receiving telescope, set of single-element receivers for measurement of the elastic backscatter radiation, and multi-element receiver with monochromator for spectrally-resolved LIF measurements. The system is equipped by 2-axis scanning mirror and variable-FOV video-camera collimated with the lidar scanning direction. The LIF-lidar is mounted on a truck-based platform (20-feet container) as a part of multi-purpose mobile lidar complex and adjusted for field conditions.

Generation of femtosecond γ-ray bursts stimulated by laser-driven hosing evolution

PubMed Central

Ma, Yong; Chen, Liming; Li, Dazhang; Yan, Wenchao; Huang, Kai; Chen, Min; Sheng, Zhengming; Nakajima, Kazuhisa; Tajima, Toshiki; Zhang, Jie

2016-01-01

The promising ability of a plasma wiggler based on laser wakefield acceleration to produce betatron X-rays with photon energies of a few keV to hundreds of keV and a peak brilliance of 1022–1023 photons/s/mm2/mrad2/0.1%BW has been demonstrated, providing an alternative to large-scale synchrotron light sources. Most methods for generating betatron radiation are based on two typical approaches, one relying on an inherent transverse focusing electrostatic field, which induces transverse oscillation, and the other relying on the electron beam catching up with the rear part of the laser pulse, which results in strong electron resonance. Here, we present a new regime of betatron γ-ray radiation generated by stimulating a large-amplitude transverse oscillation of a continuously injected electron bunch through the hosing of the bubble induced by the carrier envelope phase (CEP) effect of the self-steepened laser pulse. Our method increases the critical photon energy to the MeV level, according to the results of particle-in-cell (PIC) simulations. The highly collimated, energetic and femtosecond γ-ray bursts that are produced in this way may provide an interesting potential means of exploring nuclear physics in table top photo nuclear reactions. PMID:27457890

Accelerators for Discovery Science and Security applications

NASA Astrophysics Data System (ADS)

Todd, A. M. M.; Bluem, H. P.; Jarvis, J. D.; Park, J. H.; Rathke, J. W.; Schultheiss, T. J.

2015-05-01

Several Advanced Energy Systems (AES) accelerator projects that span applications in Discovery Science and Security are described. The design and performance of the IR and THz free electron laser (FEL) at the Fritz-Haber-Institut der Max-Planck-Gesellschaft in Berlin that is now an operating user facility for physical chemistry research in molecular and cluster spectroscopy as well as surface science, is highlighted. The device was designed to meet challenging specifications, including a final energy adjustable in the range of 15-50 MeV, low longitudinal emittance (<50 keV-psec) and transverse emittance (<20 π mm-mrad), at more than 200 pC bunch charge with a micropulse repetition rate of 1 GHz and a macropulse length of up to 15 μs. Secondly, we will describe an ongoing effort to develop an ultrafast electron diffraction (UED) source that is scheduled for completion in 2015 with prototype testing taking place at the Brookhaven National Laboratory (BNL) Accelerator Test Facility (ATF). This tabletop X-band system will find application in time-resolved chemical imaging and as a resource for drug-cell interaction analysis. A third active area at AES is accelerators for security applications where we will cover some top-level aspects of THz and X-ray systems that are under development and in testing for stand-off and portal detection.

High-quality beam generation using an RF gun and a 150 MeV microtron

NASA Astrophysics Data System (ADS)

Kuroda, R.; Washio, M.; Kashiwagi, S.; Kobuki, T.; Ben-Zvi, I.; Wang, X. J.; Hori, T.; Sakai, F.; Tsunemi, A.; Urakawa, J.; Hirose, T.

2000-11-01

Low-emittance sub-picosecond electron pulses are expected to be used in a wide field, such as free electron laser, laser acceleration, femtosecond X-ray generation by Inverse Compton scattering, pulse radiolysis, etc. In order to produce the low-emittance sub-picosecond electron pulse, we are developing a compact Racetrack Microtron (RTM) with a new 5 MeV injection system adopting a laser photo cathode RF gun (Washio et al., Seventh China-Japan Bilateral Symposium on Radiation Chemistry, October 28, Cengdu, China, 1996). The operation of RTM has been kept under a steady state of beam loading for long pulse mode so far (Washio et al., J. Surf. Sci. Soc. Jpn. 19 (2) (1998) 23). In earlier work (Washio et al., PAC99, March 31, New York, USA, 1999), we have succeeded in the numerical simulation for the case of single short pulse acceleration. Finally, the modified RTM was demonstrated as a useful accelerator for a picosecond electron pulse generation under a transient state of beam loading. In the simulation, a picosecond electron pulse was accelerated to 149.6 MeV in RTM for the injection of 5 MeV electron bunch with a pulse length of 10 ps (FWHM), a charge of 1 nC per pulse, and an emittance of 3 πmm mrad.

Ultra-bright γ-ray flashes and dense attosecond positron bunches from two counter-propagating laser pulses irradiating a micro-wire target.

PubMed

Li, Han-Zhen; Yu, Tong-Pu; Hu, Li-Xiang; Yin, Yan; Zou, De-Bin; Liu, Jian-Xun; Wang, Wei-Quan; Hu, Shun; Shao, Fu-Qiu

2017-09-04

We propose a novel scheme to generate ultra-bright ultra-short γ-ray flashes and high-energy-density attosecond positron bunches by using multi-dimensional particle-in-cell simulations with quantum electrodynamics effects incorporated. By irradiating a 10 PW laser pulse with an intensity of 10 23 W/cm 2 onto a micro-wire target, surface electrons are dragged-out of the micro-wire and are effectively accelerated to several GeV energies by the laser ponderomotive force, forming relativistic attosecond electron bunches. When these electrons interact with the probe pulse from the other side, ultra-short γ-ray flashes are emitted with an ultra-high peak brightness of 1.8 × 10 24 photons s -1 mm -2 mrad -2 per 0.1%BW at 24 MeV. These photons propagate with a low divergence and collide with the probe pulse, triggering the Breit-Wheeler process. Dense attosecond e - e + pair bunches are produced with the positron energy density as high as 10 17 J/m 3 and number of 10 9 . Such ultra-bright ultra-short γ-ray flashes and secondary positron beams may have potential applications in fundamental physics, high-energy-density physics, applied science and laboratory astrophysics.

Next generation diode lasers with enhanced brightness

NASA Astrophysics Data System (ADS)

Ried, S.; Rauch, S.; Irmler, L.; Rikels, J.; Killi, A.; Papastathopoulos, E.; Sarailou, E.; Zimer, H.

2018-02-01

High-power diode lasers are nowadays well established manufacturing tools in high power materials processing, mainly for tactile welding, surface treatment and cladding applications. Typical beam parameter products (BPP) of such lasers range from 30 to 50 mm·mrad at several kilowatts of output power. TRUMPF offers a product line of diode lasers to its customers ranging from 150 W up to 6 kW of output power. These diode lasers combine high reliability with small footprint and high efficiency. However, up to now these lasers are limited in brightness due to the commonly used spatial and coarse spectral beam combining techniques. Recently diode lasers with enhanced brightness have been presented by use of dense wavelength multiplexing (DWM). In this paper we report on TRUMPF's diode lasers utilizing DWM. We demonstrate a 2 kW and a 4 kW system ideally suited for fine welding and scanner welding applications. The typical laser efficiency is in the range of 50%. The system offers plug and play exchange of the fiber beam delivery cable, multiple optical outputs and integrated cooling in a very compact package. An advanced control system offers flexible integration in any customer's shop floor environment and includes industry 4.0 capabilities (e.g. condition monitoring and predictive maintenance).

LWIR hyperspectral imager based on a diffractive optics lens

NASA Astrophysics Data System (ADS)

Gupta, Neelam

2009-05-01

A diffractive optics lens based longwave infrared hyperspectral imager has been used to collect laboratory and outdoor field test data. The imager uses a specially designed diffractive optics Ge lens with a 320×256 HgCdTe focal plane array (FPA) cooled with a Sterling-cooler. The imager operates in 8-10.5 μm (long wave IR, LWIR) spectral region and an image cube with 50 to 200 bands can be acquired rapidly. Spectral images at different wavelengths are obtained by moving the lens along its optical axis. An f/2.38 diffractive lens is used with a focal length of 70 mm at 8 μm. The IFOV is 0.57 mrad which corresponds to an FOV of 10.48°. The spectral resolution of the imager is 0.034 μm at 9 μm. The pixel size is 40×40 μm2 in the FPA. In post processing of image cube data contributions due to wavelengths other than the focused one are removed and a correction to account for the change in magnification due to the motion of the lens is applied to each spectral image. A brief description of the imager, data collection and analysis to characterize the performance of the imager will be presented in this paper.

P-S & S-P Elastic Wave Conversions from Linear Arrays of Oriented Microcracks

NASA Astrophysics Data System (ADS)

Jiang, L.; Modiriasari, A.; Bobet, A.; Pyrak-Nolte, L. J.

2017-12-01

Natural and induced processes can produce oriented mechanical discontinuities such as en echelon cracks, fractures and faults. Previous research has shown that compressional to shear (P-S) wave conversions occur at normal incidence to a fracture because of cross-coupling fracture compliances (Nakagawa et al., 2000). Here, experiments and computer simulation are presented to demonstrate the link among cross-coupling stiffness, microcrack orientation and energy partitioning among P, S, and P-S/S-P waves. A FormLabs 2 3D printer was used to fabricate 7 samples (50 mm x 50 mm x 100 mm) with linear arrays of microcracks oriented at 0, 15, 30, 45, 60, 75, and 900 with a print resolution of 0.025 mm. The microcracks were elliptical in cross-sections (2 mm long by 1 mm wide), through the 50 mm thickness of sample, and spaced 3 mm (center-to-center for adjacent cracks). A 25 mm length of each sample contained no microcracks to act as a reference material. Broadband transducers (0.2-1.5 MHz) were used to transmit and receive P and polarized S wave signals that were propagated at normal incidence to the linear array of microcracks. P-wave amplitude increased, while S-wave amplitude remained relatively constant, as the microcrack orientation increased from 0o to 90o. At normal incidence, P-S and S-P wave conversions emerged and increased in amplitude as the crack inclination increased from 00 to 450. From 450 to 900, the amplitude of these converted modes decreased. Between negative and positive crack angles, the P-to-S and S-to-P waves were 1800 phase reversed. The observed energy partitioning matched the computed compliances obtained from numerical simulations with ABAQUS. The cross-coupling compliance for cracks inclined at 450 was found to be the smallest magnitude. 3D printing enabled the study of microstructural effects on macro-scale wave measurements. Information on the orientation of microcracks or even en echelon fractures and faults is contained in P-S conversions even at normal incidence. Acknowledgment: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Geosciences Research Program under Award Number (DE-FG02-09ER16022) and by the National Science Foundation, Geomechanics and Geotechnical Systems Program (award No. CMMI-1162082).

Corneal Epithelium Thickness Profile in 614 Normal Chinese Children Aged 7-15 Years Old.

PubMed

Ma, Yingyan; He, Xiangui; Zhu, Xiaofeng; Lu, Lina; Zhu, Jianfeng; Zou, Haidong

2016-03-23

The purpose of the study is to describe the values and distribution of corneal epithelium thickness (CET) in normal Chinese school-aged children, and to explore associated factors with CET. CET maps were measured by Fourier-domain optical coherence tomography (FD-OCT) in normal Chinese children aged 7 to 15 years old from two randomly selected schools in Shanghai, China. Children with normal intraocular pressure were further examined for cycloplegic autorefraction, corneal curvature radius (CCR) and axial length. Central (2-mm diameter area), para-central (2- to 5-mm diameter area), and peripheral (5- to 6-mm diameter area) CET in the superior, superotemporal, temporal, inferotemporal, inferior, inferonasal, nasal, superonasal cornea; minimum, maximum, range, and standard deviation of CET within the 5-mm diameter area were recorded. The CET was thinner in the superior than in the inferior and was thinner in the temporal than in the nasal. The maximum CET was located in the inferior zone, and the minimum CET was in the superior zone. A thicker central CET was associated with male gender (p = 0.009) and older age (p = 0.037) but not with CCR (p = 0.061), axial length (p = 0.253), or refraction (p = 0.351) in the multiple regression analyses. CCR, age, and gender were correlated with para-central and peripheral CET.

Three-dimensional assessment of the normal Japanese glenoid and comparison with the normal French glenoid.

PubMed

Mizuno, N; Nonaka, S; Ozaki, R; Yoshida, M; Yoneda, M; Walch, G

2017-12-01

In 2014, reverse total shoulder arthroplasty was approved in Japan. We were concerned that the base plate might be incompatible with Japanese who were generally smaller than Westerners. Therefore, we investigated the dimensions and morphology of the normal Japanese glenoid and compared with the normal French glenoid. One hundred Japanese shoulders without glenoid lesions (50 men and 50 women) were investigated and compared with 100 French shoulders (50 men and 50 women). Computed tomography was performed with 3-dimensional image reconstruction and images were analyzed using Glenosys software. Glenoid parameters (width, height, retroversion and inclination) were compared between Japanese and French subjects. In Japanese subjects, the mean glenoid width was 25.5mm, height was 33.3mm, retroversion was 2.3° and inclination was 11.6° superiorly. In French subjects, the mean glenoid width was 26.7mm, height was 35.4mm, retroversion was 6.0° and inclination was 10.4° superiorly. Glenoid width and height were significantly smaller in Japanese subjects than French subjects (P=0.001 and P<0.001), while retroversion was significantly greater in French subjects (P<0.001). There was no significant difference of inclination. These findings will help surgeons to identify suitable patients for RSA and perform the procedure with appropriate preoperative planning. IV: retrospective or historical series. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Prenasal thickness to nasal bone length ratio in normal and trisomy 21 fetuses at 11-14 weeks of gestation.

PubMed

Manegold-Brauer, Gwendolin; Bourdil, Lucas; Berg, Christoph; Schoetzau, Andreas; Gembruch, Ulrich; Geipel, Annegret

2015-11-01

To show the feasibility and to create a reference range for prenasal thickness (PT) and for the PT to nasal bone length (NBL) ratio in normal fetuses at 11-14 gestational weeks and to compare the findings to fetuses with trisomy 21. PT, NBL and PT/NBL ratio were measured retrospectively in stored two-dimensional images of 1155 normal fetuses and 44 fetuses with trisomy 21. Mid-sagittal images were acquired at first trimester ultrasound examinations and were selected from our digital database. The PT increased with CRL from 1.0 mm at 45-mm CRL to 1.6 mm at 84-mm CRL. The mean PT/NBL ratio was 0.6 and was not altered by CRL. The mean PT/NBL ratio in fetuses with trisomy 21 was significantly higher than in normal fetuses (p < 0.0001). For a cut-off value of 0.8 the PT/NBL yielded a sensitivity of 86.4% and a specificity of 98.4% for trisomy 21. The assessment of PT between 11 and 14 gestational weeks is feasible with high intraclass correlation. The PT to NBL ratio seems to be a promising marker for trisomy 21 in the first trimester and was superior to the isolated contribution of NBL and PT measurements. © 2015 John Wiley & Sons, Ltd.

Normal dimensions of the posterior pituitary bright spot on magnetic resonance imaging.

PubMed

Côté, Martin; Salzman, Karen L; Sorour, Mohammad; Couldwell, William T

2014-02-01

The normal pituitary bright spot seen on unenhanced T1-weighted MRI is thought to result from the T1-shortening effect of the vasopressin stored in the posterior pituitary. Individual variations in its size may be difficult to differentiate from pathological conditions resulting in either absence of the pituitary bright spot or in T1-hyperintense lesions of the sella. The objective of this paper was to define a range of normal dimensions of the pituitary bright spot and to illustrate some of the most commonly encountered pathologies that result in absence or enlargement of the pituitary bright spot. The authors selected normal pituitary MRI studies from 106 patients with no pituitary abnormality. The size of each pituitary bright spot was measured in the longest axis and in the dimension perpendicular to this axis to describe the typical dimensions. The authors also present cases of patients with pituitary abnormalities to highlight the differences and potential overlap between normal and pathological pituitary imaging. All of the studies evaluated were found to have pituitary bright spots, and the mean dimensions were 4.8 mm in the long axis and 2.4 mm in the short axis. The dimension of the pituitary bright spot in the long axis decreased with patient age. The distribution of dimensions of the pituitary bright spot was normal, indicating that 99.7% of patients should have a pituitary bright spot measuring between 1.2 and 8.5 mm in its long axis and between 0.4 and 4.4 mm in its short axis, an interval corresponding to 3 standard deviations below and above the mean. In cases where the dimension of the pituitary bright spot is outside this range, pathological conditions should be considered. The pituitary bright spot should always be demonstrated on T1-weighted MRI, and its dimensions should be within the identified normal range in most patients. Outside of this range, pathological conditions affecting the pituitary bright spot should be considered.

Placement of iliosacral screws using 3D image-guided (O-Arm) technology and Stealth Navigation: comparison with traditional fluoroscopy.

PubMed

Theologis, A A; Burch, S; Pekmezci, M

2016-05-01

We compared the accuracy, operating time and radiation exposure of the introduction of iliosacral screws using O-arm/Stealth Navigation and standard fluoroscopy. Iliosacral screws were introduced percutaneously into the first sacral body (S1) of ten human cadavers, four men and six women. The mean age was 77 years (58 to 85). Screws were introduced using a standard technique into the left side of S1 using C-Arm fluoroscopy and then into the right side using O-Arm/Stealth Navigation. The radiation was measured on the surgeon by dosimeters placed under a lead thyroid shield and apron, on a finger, a hat and on the cadavers. There were no neuroforaminal breaches in either group. The set-up time for the O-Arm was significantly longer than for the C-Arm, while total time for placement of the screws was significantly shorter for the O-Arm than for the C-Arm (p = 0.001). The mean absorbed radiation dose during fluoroscopy was 1063 mRad (432.5 mRad to 4150 mRad). No radiation was detected on the surgeon during fluoroscopy, or when he left the room during the use of the O-Arm. The mean radiation detected on the cadavers was significantly higher in the O-Arm group (2710 mRem standard deviation (sd) 1922) than during fluoroscopy (11.9 mRem sd 14.8) (p < 0.01). O-Arm/Stealth Navigation allows for faster percutaneous placement of iliosacral screws in a radiation-free environment for surgeons, albeit with the same accuracy and significantly more radiation exposure to cadavers, when compared with standard fluoroscopy. Placement of iliosacral screws with O-Arm/Stealth Navigation can be performed safely and effectively. Cite this article: Bone Joint J 2016;98-B:696-702. ©2016 The British Editorial Society of Bone & Joint Surgery.

Initial Performance Evaluation of Optical Fibers and Sensors Under High-Energy Electron Beam Irradiation

NASA Astrophysics Data System (ADS)

Palmer, Matthew E.; Slusher, David; Fielder, Robert S.

2006-01-01

In this paper, recent work on the performance of optical fiber, fiber optic sensors, and fiber optic connectors under the influence of a high-energy electron beam is presented. Electron beam irradiation is relevant for the Jupiter Icy Moons Orbiter (JIMO) mission due to the high electron radiation environment surrounding Jupiter. As an initial feasibility test, selected optical fiber components were exposed to dose levels relevant to the Jupiter environment. Three separate fiber types were used: one series consisted of pure silica core fiber, two other series consisted of different levels of Germania-doped fiber. Additionally, a series of fused silica Extrinsic Fabry-Perot Interferometer (EFPI)-based fiber optic sensors and two different types of fiber optic connectors were tested. Two types of fiber coatings were evaluated: acrylate and polyimide. All samples were exposed to three different dose levels: 2 MRad, 20 MRad, and 50 MRad. Optical loss measurements were made on the optical fiber spools as a function of wavelength between 750 and 1750nm at periodic intervals up to 75 hrs after exposure. Attenuation is minimal and wavelength-dependent. Fiber optic sensors were evaluated using a standard EFPI sensor readout and diagnostic system. Optical connectors and optical fiber coatings were visually inspected for degradation. Additionally, tensile testing and minimum bend radius testing was conducted on the fibers. Initial loss measurements indicate a low-level of induced optical attenuation in the fiber which recovers with time. The fiber optic sensors exhibited no observable degradation after exposure. The optical fiber connectors and coatings also showed no observable degradation. In addition to harsh environment survivability, fiber optic sensors offer a number of intrinsic advantages for space nuclear power applications including extremely low mass, immunity to electromagnetic interference, self diagnostics / prognostics, and smart sensor capability. Deploying fiber optic sensors on future space exploration missions would provide a substantial improvement in spacecraft instrumentation.

Dynamic Three-Dimensional Shoulder Mri during Active Motion for Investigation of Rotator Cuff Diseases.

PubMed

Tempelaere, Christine; Pierrart, Jérome; Lefèvre-Colau, Marie-Martine; Vuillemin, Valérie; Cuénod, Charles-André; Hansen, Ulrich; Mir, Olivier; Skalli, Wafa; Gregory, Thomas

2016-01-01

MRI is the standard methodology in diagnosis of rotator cuff diseases. However, many patients continue to have pain despite treatment, and MRI of a static unloaded shoulder seems insufficient for best diagnosis and treatment. This study evaluated if Dynamic MRI provides novel kinematic data that can be used to improve the understanding, diagnosis and best treatment of rotator cuff diseases. Dynamic MRI provided real-time 3D image series and was used to measure changes in the width of subacromial space, superior-inferior translation and anterior-posterior translation of the humeral head relative to the glenoid during active abduction. These measures were investigated for consistency with the rotator cuff diseases classifications from standard MRI. The study included: 4 shoulders with massive rotator cuff tears, 5 shoulders with an isolated full-thickness supraspinatus tear, 5 shoulders with tendinopathy and 6 normal shoulders. A change in the width of subacromial space greater than 4mm differentiated between rotator cuff diseases with tendon tears (massive cuff tears and supraspinatus tear) and without tears (tendinopathy) (p = 0.012). The range of the superior-inferior translation was higher in the massive cuff tears group (6.4mm) than in normals (3.4mm) (p = 0.02). The range of the anterior-posterior translation was higher in the massive cuff tears (9.2 mm) and supraspinatus tear (9.3 mm) shoulders compared to normals (3.5mm) and tendinopathy (4.8mm) shoulders (p = 0.05). The Dynamic MRI enabled a novel measure; 'Looseness', i.e. the translation of the humeral head on the glenoid during an abduction cycle. Looseness was better able at differentiating different forms of rotator cuff disease than a simple static measure of relative glenohumeral position.

Dynamic Three-Dimensional Shoulder Mri during Active Motion for Investigation of Rotator Cuff Diseases

PubMed Central

Tempelaere, Christine; Pierrart, Jérome; Lefèvre-Colau, Marie-Martine; Vuillemin, Valérie; Cuénod, Charles-André; Hansen, Ulrich; Mir, Olivier; Skalli, Wafa; Gregory, Thomas

2016-01-01

Background MRI is the standard methodology in diagnosis of rotator cuff diseases. However, many patients continue to have pain despite treatment, and MRI of a static unloaded shoulder seems insufficient for best diagnosis and treatment. This study evaluated if Dynamic MRI provides novel kinematic data that can be used to improve the understanding, diagnosis and best treatment of rotator cuff diseases. Methods Dynamic MRI provided real-time 3D image series and was used to measure changes in the width of subacromial space, superior-inferior translation and anterior-posterior translation of the humeral head relative to the glenoid during active abduction. These measures were investigated for consistency with the rotator cuff diseases classifications from standard MRI. Results The study included: 4 shoulders with massive rotator cuff tears, 5 shoulders with an isolated full-thickness supraspinatus tear, 5 shoulders with tendinopathy and 6 normal shoulders. A change in the width of subacromial space greater than 4mm differentiated between rotator cuff diseases with tendon tears (massive cuff tears and supraspinatus tear) and without tears (tendinopathy) (p = 0.012). The range of the superior-inferior translation was higher in the massive cuff tears group (6.4mm) than in normals (3.4mm) (p = 0.02). The range of the anterior-posterior translation was higher in the massive cuff tears (9.2 mm) and supraspinatus tear (9.3 mm) shoulders compared to normals (3.5mm) and tendinopathy (4.8mm) shoulders (p = 0.05). Conclusion The Dynamic MRI enabled a novel measure; ‘Looseness’, i.e. the translation of the humeral head on the glenoid during an abduction cycle. Looseness was better able at differentiating different forms of rotator cuff disease than a simple static measure of relative glenohumeral position. PMID:27434235

[Three-dimensional computed tomography analysis and clinical application of sacroiliac screw placement].

PubMed

Yin, Y C; Zhang, R P; Li, S L; Hou, Z Y; Chen, W; Zhang, Y Z

2018-03-01

Objective: To evaluate the possibility of transverse sacroiliac screw placement in different segments of the sacrum. Methods: Data of 80 pelvic CT scans (slice thickness ≤1.0 mm) archived in CT department of the Third Hospital of Hebei Medical University from September 2016 to October 2017 were retrospectively collected. Mimics software was used to rebuild the pelvis three-dimensional model. According to whether the sacral 1(S(1)) segment could place the transverse sacroiliac screws or not, all the sacrums were divided into normal group ( n =55) and dysmorphic group ( n =25). Simulation the S(1), sacral 2(S(2)) transverse sacroiliac screw placement in 3-Matic software. Analysis whether there was any difference in maximum diameter and length of S(2) transverse sacroiliac screw between the normal group and the dysmorphic group. The pelvic CT data of the dysmorphic group were measured, and the optimal tilt angle and length of the oblique S(1) screw were obtained. The feasibility of transverse sacroiliac screw insertion in sacral 3(S(3)) segment was evaluated. t -test, rank sum test, and χ(2) test was used to analyze data, respectively. Results: In the dysmorphic group, the largest diameter of the S(1) transverse screw was (4.9±1.6)mm, and the normal group was (13.6±3.6)mm ( t =-15.07, P =0.00). In the dysmorphic group, the largest diameter of S(2) transverse screw was (13.8±3.0)mm, and was (12.4±2.2)mm in the normal group( t =2.11, P =0.04). There was no significant difference in the length of S(2) transverse sacroiliac screw between the two groups ( t =0.47, P =0.64). In the dysmorphic group, the anterior vertebral height of S(1) was (23.1±4.0)mm, which was significantly higher than that of the normal group ((14.1±4.2)mm)( t =9.01, P =0.00). The angle of S(1)S(2) in the dysmorphic group was 10.9°(3.8°, 17.6°), which was significantly larger than that of the normal group (2.0°(1.0°, 2.0°) ( Z =-4.03, P =0.00). In the dysmorphic group, the incline angle of the oblique S(1) sacroiliac screw was (35.6±6.2)°, the anteversion angle was (37.2±4.4)°, and the mean screw length was (90.2±4.7)mm. In the dysmorphic group, the placement rate of S(3) transverse sacroiliac screw was 48.0%, and that of the normal sacral group was 9.1%. Conclusions: There is often dysmorphic in the sacrum in patients with large S(1) anterior vertebral height and S(1)S(2) angle. Sacral dysmorphic patients with posterior pelvic ring injury may be treated with S(1) pedicle oblique sacroiliac screws. S(3) transverse sacroiliac screws should be carefully placed, especially for the absence of sacral dysmorphic in patients.

Expression of microphthalmia transcription factor, S100 protein, and HMB-45 in malignant melanoma and pigmented nevi.

PubMed

Xia, Jianxin; Wang, Yanlong; Li, Fuqiu; Wang, Jinfeng; Mu, Yan; Mei, Xianglin; Li, Xue; Zhu, Wenjing; Jin, Xianhua; Yu, Kai

2016-09-01

Malignant melanoma (MM) is a type of malignant tumor, which originates from neural crest melanocytes. MM progresses rapidly and results in a high mortality rate. The present study aims to investigate the expression of microphthalmia transcription factor (MITF), the S100 protein, and HMB-45 in MM and pigmented nevi. A total of 32 MM samples (including three skin metastasis, three lymph node metastasis and two spindle cell MM samples), two Spitz nevus samples, four pigmented nevus samples and two blue nevus samples were collected. The expression levels of S100 protein, HMB-45, and MITF were observed via immunostaining. The S100 protein exhibited high positive rates in MM and pigment disorders (96.7 and 100%, respectively), but with low specificity. The S100 protein was also expressed in fibroblasts, myoepithelial cells, histocytes and Langerhans cells in normal skin samples. HMB-45 had high specificity. Its positive expression was only confined to MM cells and junctional nevus cells. Furthermore, HMB-45 was not expressed in melanocytes in the normal tissue samples around the tumor or in the benign intradermal nevus cells. MITF exhibited high specificity and high sensitivity. It was expressed in the nuclei of melanocytes, MM cells and nevus cells. It was observed to be strongly expressed in metastatic MM and spindle cell MMs. Thus, MITF may present as a specific immunomarker for the diagnosis and differential diagnosis of MM.

Effects of Cilnidipine, an L/N-Type Calcium Channel Blocker, on Carotid Atherosclerosis in Japanese Post-Stroke Hypertensive Patients: Results from the CA-ATTEND Study.

PubMed

Nezu, Tomohisa; Hosomi, Naohisa; Aoki, Shiro; Suzuki, Noriyuki; Teshima, Tsukasa; Sugii, Hitoshi; Nagahama, Shinobu; Kurose, Yoshiki; Maruyama, Hirofumi; Matsumoto, Masayasu

2018-06-01

Although several antihypertensive agents reduced the carotid intima-media thickness (IMT), it remains unclear whether those agents affect the interadventitial diameter (IAD). We aimed to examine whether cilnidipine, an L/N-type calcium channel blocker, reduced the common carotid IMT or IAD in post-stroke hypertensive patients. The common carotid IMT and IAD were measured at the start of cilnidipine treatment and 12 months from that. The changes in the mean max-IMT or IAD between baseline and the 12-month follow-up were evaluated and compared between the thick group (max-IMT ≥1.1 mm) and the normal group (max-IMT ＜1.1 mm). A total of 603 post-stroke hypertensive subjects (mean age=69.3 yr, 378 males) were included in the analysis. At baseline, IAD was increased stepwise according to the value of max-IMT (p for trend ＜0.001). Among them, 326 subjects were followed up for 12 months. The mean max-IMT from baseline to 12 months did not change in the normal group (－0.01 mm, 95% confidence interval [CI] －0.03 to 0.01, n=170), whereas a significant reduction was observed in the thick group (－0.09 mm, 95% CI －0.13 to －0.05, n=156). The mean IAD was significantly reduced during the study period in the normal group (－0.14 mm, 95% CI －0.22 to －0.05) as well as in the thick group (－0.12 mm, 95% CI －0.21 to －0.03). Cilnidipine promoted the regression of common carotid IMT in post-stroke hypertensive patients, especially in the thick group. Cilnidipine also reduced the IAD in both normal and thick groups.

Parametric normalization for full-energy peak efficiency of HPGe γ-ray spectrometers at different counting positions for bulky sources.

PubMed

Peng, Nie; Bang-Fa, Ni; Wei-Zhi, Tian

2013-02-01

Application of effective interaction depth (EID) principle for parametric normalization of full energy peak efficiencies at different counting positions, originally for quasi-point sources, has been extended to bulky sources (within ∅30 mm×40 mm) with arbitrary matrices. It is also proved that the EID function for quasi-point source can be directly used for cylindrical bulky sources (within ∅30 mm×40 mm) with the geometric center as effective point source for low atomic number (Z) and low density (D) media and high energy γ-rays. It is also found that in general EID for bulky sources is dependent upon Z and D of the medium and the energy of the γ-rays in question. In addition, the EID principle was theoretically verified by MCNP calculations. Copyright © 2012 Elsevier Ltd. All rights reserved.

Defining Normal Parameters for the Male Nipple-Areola Complex: A Prospective Observational Study and Recommendations for Placement on the Chest Wall.

PubMed

Yue, Dominic; Cooper, Lilli R L; Kerstein, Ryan; Charman, Susan C; Kang, Norbert V

2018-01-10

The nipple-areola complex (NAC) is important aesthetically and functionally for both sexes. Methods for positioning the NAC in males are less well established in the literature compared to females but are just as important. This study aims to determine the normal parameters for the male NAC, to review literature, and to present a reliable method for preoperative placement. Normal male patients, with no prior chest wall conditions, were prospectively recruited to participate. General demographics and chest wall dimensions were recorded-sternal notch to nipple (SNND), internipple (IND), anterior axillary folds distances (AFD), NAC, and chest circumference were measured. Comparisons were made using t test and ANOVA. One hundred and fifty-eight patients were recruited (age range, 18-90 years); mostly (86.7%) with normal or overweight BMI. The IND averaged 249.4 mm, the SNND averaged 204.2 mm, and the AFD averaged 383.8 mm. Areola diameter averaged 26.6 mm and for the nipple, 6.9 mm. The IND:AFD ratio was 0.65. There was no statistical difference in the IND:AFD ratio, SNND, or NAC parameters comparing different ethnic groups. The SNND increased with greater BMI (P ≤ 0.001). Using these data, we suggest ideal NAC dimensions and devised a simple method for positioning of the NAC on the male chest wall. This is the largest study, with the widest range in age and BMI, to date on this topic. Although fewer men than women undergo surgery to the breast, there is a growing awareness for enhancing the appearance of the male chest wall. © 2018 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com

Significance of an Increase in Diastolic Blood Pressure during a Stress Test in Terms of Comorbidities and Long-term Total and CV Mortality.

PubMed

Sydó, Nóra; Sydó, Tibor; Gonzalez Carta, Karina A; Hussain, Nasir; Merkely, Béla; Murphy, Joseph G; Squires, Ray W; Lopez-Jimenez, Francisco; Allison, Thomas G

2018-05-15

A decrease in diastolic blood pressure (DBP) with exercise is considered normal, but the significance of an increase in DBP has not been validated. Our aim was to determine the relationship of DBP increasing on a stress test regarding comorbidities and mortality. Our database was reviewed from 1993-2010 using the first stress test of a patient. Non-Minnesota residence, baseline CV disease, rest DBP <60 or >100 mmHg, and age <30 or ≥80 were exclusion criteria. DBP response was classified Normal if peak DBP-rest DBP <0, Borderline 0-9, Abnormal ≥10mmHg. Mortality was determined from Mayo Clinic records and Minnesota Death Index. Logistic regression was used to determine the relationship of DBP response to presence of comorbidities. Cox regression was used to determine total and CV mortality risk by DBP response. All analyses were adjusted for age, sex and resting DBP. 20760 patients were included (51±11 years, female n=7314). Rest/peak averaged DBP 82±8/69 ±15 mmHg in normal vs 79±9/82±9 mmHg in borderline vs 76±9/92±11 mmHg in abnormal DBP response. There were 1582 deaths (8%) with 557 (3%) CV deaths over 12±5 years of follow-up. In patients with borderline and abnormal DBP response, odds ratios for obesity, hypertension, diabetes and current smoking were significant, while hazard ratios for total and CV death were not significant compared to patients with normal DBP response. DBP response to exercise is significantly associated with important comorbidities at the time of the stress test but does not add to the prognostic yield of stress test.

Normal Axillary Lymph Node Variability Between White and Black Women on Breast MRI.

PubMed

Grimm, Lars J; Viradia, Neal K; Johnson, Karen S

2018-03-01

This study aimed to determine if there were differences in the imaging features of normal lymph nodes between white and black women using magnetic resonance imaging. Following institutional review board approval, we identified white and black women who underwent breast magnetic resonance imaging from November 1, 2008 to December 31, 2013 at our institution. To identify normal lymph nodes for measurement, patients with any benign or malignant causes for lymph node enlargement and patients with any subsequent breast cancer in the following 2 years were excluded. Black and white women were age matched at a 1:2 ratio. The largest lymph node in each axilla was measured for the long-axis length and maximal cortical thickness. Comparisons were made between white and black women using a conditional logistic regression to control for matching. There were 55 black women and 110 white women for analysis. The mean lymph node long-axis length was 14.7 ± 5.3 mm for black women and 14.4 ± 6.4 mm for white women (P = .678). The mean maximum cortical thickness was 3.3 ± 1.6 mm for black women and 2.6 ± 1.4 mm for Caucasian women (P < .001). A significantly higher percentage of black than white women had cortical thicknesses greater than threshold values of 3, 4, 5, 6, and 7 mm (P < .01 for all). The normal lymph node cortical thickness in black women is significantly greater than in white women, which should be considered when deciding to recommend a lymph node biopsy. Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Phonon assisted electronic transition in telluric acid ammonium phosphate single crystals

NASA Astrophysics Data System (ADS)

El-Muraikhi, M.; Kassem, M. E.; Al-Houty, L.

The effect of gamma-irradiation on the absorption optical spectra of telluric acid ammonium phosphate single crystals (TAAP) has been studied, in the wave length of 200-600 nm, for samples irradiated by various doses up to 10 Mrad. The results show that the electron phonon coupling constant increases with the irradiation dose.

Relation between small airways disease and parenchymal destruction in surgical lung specimens.

PubMed Central

Willems, L N; Kramps, J A; Stijnen, T; Sterk, P J; Weening, J J; Dijkman, J H

1990-01-01

The relation between small airways disease and parenchymal destruction was investigated in lungs and lobes removed at surgery from 27 patients aged 15-70 years. Eight of the 27 patients were life-long non-smokers. The degree of small airways disease was assessed by semi-quantitative grading (SAD score) and by measuring diameter and wall thickness of membranous bronchioles. Parenchymal destruction was measured in three ways. Firstly, the number of alveolar attachments on membranous bronchioles per millimetre of circumference (AA/mm) was counted; the number of broken attachments was subtracted from the total AA/mm to give the numbers of intact attachments (normal AA/mm). Secondly, a point counting technique was used to give a destructive index (DI). Thirdly, the mean linear intercept (Lm) was determined. Total and normal AA/mm correlated negatively with the SAD score of membranous bronchioles (rs = -0.48 and -0.51) and with wall thickness (rs = -0.37 and -0.45) and DI correlated with wall thickness (rs = 0.5) and with the SAD score of respiratory bronchioles (rs = 0.53). Lm did not correlate with indices of small airway disease and total and normal AA/mm did not correlate with diameter. Multiple regression analyses showed that the correlation of total AA/mm with the SAD score of membranous and respiratory bronchioles and with wall thickness were not confounded by age or smoking. It is concluded that small airways disease is related to destruction of peribronchiolar alveoli, and it is postulated that small airways disease has a direct role in the causation of centrilobular emphysema. PMID:2315880

In vitro biomechanical comparison of equine proximal interphalangeal joint arthrodesis techniques: prototype equine spoon plate versus axially positioned dynamic compression plate and two abaxial transarticular cortical screws inserted in lag fashion.

PubMed

Sod, Gary A; Mitchell, Colin F; Hubert, Jeremy D; Martin, George S; Gill, Marjorie S

2007-12-01

To compare in vitro monotonic biomechanical properties of an equine spoon plate (ESP) with an axial 3-hole, 4.5 mm narrow dynamic compression plate (DCP) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws (DCP-TLS) inserted in lag fashion for equine proximal interphalangeal (PIP) joint arthrodesis. Paired in vitro biomechanical testing of 2 methods of stabilizing cadaveric adult equine forelimb PIP joints. Cadaveric adult equine forelimbs (n=18 pairs). For each forelimb pair, 1 PIP joint was stabilized with an ESP (8 hole, 4.5 mm) and 1 with an axial 3-hole narrow DCP (4.5 mm) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion. Six matching pairs of constructs were tested in single cycle to failure under axial compression with load applied under displacement control at a constant rate of 5 cm/s. Six construct pairs were tested for cyclic fatigue under axial compression with cyclic load (0-7.5 kN) applied at 6 Hz; cycles to failure were recorded. Six construct pairs were tested in single cycle to failure under torsional loading applied at a constant displacement rate (0.17 radians/s) until rotation of 0.87 radians occurred. Mean values for each fixation method were compared using a paired t-test within each group with statistical significance set at P<.05. Mean yield load, yield stiffness, and failure load for ESP fixation were significantly greater (for axial compression and torsion) than for DCP-TLS fixation. Mean (+/- SD) values for the ESP and DCP-TLS fixation techniques, respectively, in single cycle to failure under axial compression were: yield load 123.9 +/- 8.96 and 28.5 +/- 3.32 kN; stiffness, 13.11 +/- 0.242 and 2.60 +/- 0.17 kN/cm; and failure load, 144.4 +/- 13.6 and 31.4 +/- 3.8 kN. In single cycle to failure under torsion, mean (+/- SD) values for ESP and DCP-TLS, respectively, were: stiffness 2,022 +/- 26.2 and 107.9 +/- 11.1 N m/rad; and failure load: 256.4 +/- 39.2 and 87.1 +/- 11.5 N m. Mean cycles to failure in axial compression of ESP fixation (622,529 +/- 65,468) was significantly greater than DCP-TLS (95,418 +/- 11,037). ESP was superior to an axial 3-hole narrow DCP with 2 abaxial transarticular screws inserted in lag fashion in resisting static overload forces and cyclic fatigue. In vitro results support further evaluation of ESP for PIP joint arthrodesis in horses. Its specific design may provide increased stability without need for external coaptation support.

Feasibility of Using Ultrasonography to Establish Relationships Among Sacral Base Position, Sacral Sulcus Depth, Body Mass Index, and Sex.

PubMed

Lockwood, Michael D; Kondrashova, Tatyana; Johnson, Jane C

2015-11-01

Identifying relationships among anatomical structures is key in diagnosing somatic dysfunction. Ultrasonography can be used to visualize anatomical structures, identify sacroiliac landmarks, and validate anatomical findings and measurements in relation to somatic dysfunction. As part of the osteopathic manipulative medicine course at A.T. Still University-Kirksville College of Osteopathic Medicine, first-year students are trained to use ultrasonography to establish relationships among musculoskeletal structures. To determine the ability of first-year osteopathic medical students to establish sacral base position (SBP) and sacral sulcus depth (SSD) using ultrasonography and to identify the relationship of SBP and SSD to body mass index (BMI) and sex. Students used ultrasonography to obtain the distance between the skin and the sacral base (the SBP) and the distance between the skin and the tip of the posterior superior iliac spine bilaterally. Next, students calculated the SSD (the distance between the tip of the posterior superior iliac spine and the SBP). Data were analyzed with respect to side of the body, BMI, sex, and age. The BMI data were subdivided into normal (18-25 mg/kg) and overweight (25-30 mg/kg) groups. Ultrasound images of 211 students were included in the study. The SBP was not significantly different between the left and right sides (36.5 mm vs 36.5 mm; P=.95) but was significantly different between normal and overweight BMI categories (33.0 mm vs 40.0 mm; P<.001) and between men and women (34.1 mm vs 39.0 mm; P<.001). The SSD was not significantly different between left and right sides (18.9 mm vs 19.8 mm; P=.08), normal and overweight BMI categories (18.9 mm vs 19.7 mm, P=.21), or men and women (19.7 mm vs 19.0 mm; P=.24). No significant relationship was identified between age and SBP (P=.46) or SSD (P=.39); however, the age range was narrow (21-33 years). The study yielded repeatable and reproducible results when establishing SBP and SSD using ultrasonography. The statistically significant relationship between SBP and higher BMI and between SBP and female sex may point to more soft tissue overlaying the sacrum in these groups. Further research is needed on the use of ultrasonography to establish criteria for somatic dysfunction.

Dual beam Nd:YAG laser welding: influence of lubricants to lap joint welding of steel sheets

NASA Astrophysics Data System (ADS)

Geiger, M.; Merklein, M.; Otto, A.; Blankl, A.

2007-05-01

Laser welding is applied in large-volume production since the late eighties and has revolutionized the possibilities of designing and engineering products. Nevertheless, problems appear during application because the operational conditions in industrial environments fluctuate and can influence the welding process negatively. Contaminations, like lubricants and organic solids, are an example of changing conditions in laser beam welding. If a lap joint is welded, these materials have to be removed from the sheets, otherwise pores and surface failures may appear due to keyhole instabilities induced by uncontrolled outgassing. One possibility for solving this problem is the use of two separate laser beams. For producing these two beams several systems are available for all different kind of lasers. A bifocal optic is such a solution for an Nd:YAG laser. By using this system, the laser beam is divided after collimation with a prism. Afterwards the two beams are focussed with a lens to the surface of the sheet and two single spots are produced. If the distance between the two spots is low, one common, elliptical keyhole is created. With this system two different welding strategies are possible. The spots can be oriented parallel or normal to the feed direction. For stabilizing the laser welding of contaminated steel sheets the parallel arrangement is better, because the amount of contamination is nearly the same as in single spot welding but the total volume of the keyhole is greater and so pressure variations due to uncontrolled evaporation of contaminations are lower. In order to prove this theory and to determine the exact effects some investigations were made at the Chair of Manufacturing Technology of the University of Erlangen-Nuremberg. A 4 kW Nd:YAG laser with a beam parameter product of 25 mm*mrad and a focal distance of 200 mm was used to weld two 1 mm DC04 steel sheets together with a lap joint. Between the sheets a deep drawing lubricant, Castrol FST 6, was used to simulate the contaminations. The sheets were welded with mono- and bifocal optic, whereas with bifocal the power distribution between the two beams was varied. After welding, the seams were qualified by analyzing surface defects and mechanical properties. The results of the investigations show that the adoption of a bifocal optic can increase the stability of the welding process. The distribution between the two single spots has an essential influence on the welding result. In order to get a higher penetration and failure free seams, a 30 % to 70 % distribution between the two spots is better. Furthermore the blade angle has another slight impact on the welding result. For monofocus and bifocus a towing angle between the sheets and the beam produces better welding results. Considering these results it can be resumed that the application of a bifocal optic is a possibility to increase the quality and the stability of lap joint welding but the parameter settings for good results can only be varied in a tight tolerance zone.

Bone marrow mesenchymal stem cells are abnormal in multiple myeloma

PubMed Central

Corre, Jill; Mahtouk, Karène; Attal, Michel; Gadelorge, Mélanie; Huynh, Anne; Fleury-Cappellesso, Sandrine; Danho, Clotaire; Laharrague, Patrick; Klein, Bernard; Rème, Thierry; Bourin, Philippe

2007-01-01

Recent literature suggested that cell of the microenvironment of solid tumors could be abnormal as well. To address this hypothesis in multiple myeloma (MM), we studied bone marrow mesenchymal stem cells (BMMSCs), the only long-lived cells of the bone marrow microenvironment, by gene expression with Affymetrix arrays and phenotypic and functional study in 3 groups of individuals: patients with MM and those with monoclonal gamopathy of undefined significance (MGUS), and healthy aged-matched subjects. Gene expression profile independently classified the BMMSCs of these individuals in a normal and in a MM group. MGUS BMMSCs were interspersed between those 2 groups. Among the 145 distinct genes differentially expressed in MM and normal BMMSCs 46% were involved in tumor-microenvironment cross-talk. Known soluble factors involved in MM pathophysiologic features, (interleukin (IL)-6, IL-1β, DKK1 and amphiregulin, were revealed and new ones found. In particular, GDF-15 was found to induce dose-dependant growth of MOLP-6, a stromal cell-dependent myeloma cell line. Functionally, MM BMMSCs induced an over-growth of MOLP-6, and their capacity to differentiate into an osteoblastic lineage was impaired. Thus, BMMSCs from MM patients could create a very efficient niche to support the survival and proliferation of the myeloma stem cells. PMID:17344918

Blood pressure in head‐injured patients

PubMed Central

Mitchell, Patrick; Gregson, Barbara A; Piper, Ian; Citerio, Giuseppe; Mendelow, A David; Chambers, Iain R

2007-01-01

Objective To determine the statistical characteristics of blood pressure (BP) readings from a large number of head‐injured patients. Methods The BrainIT group has collected high time‐resolution physiological and clinical data from head‐injured patients who require intracranial pressure (ICP) monitoring. The statistical features of this dataset of BP measurements with time resolution of 1 min from 200 patients is examined. The distributions of BP measurements and their relationship with simultaneous ICP measurements are described. Results The distributions of mean, systolic and diastolic readings are close to normal with modest skewing towards higher values. There is a trend towards an increase in blood pressure with advancing age, but this is not significant. Simultaneous blood pressure and ICP values suggest a triphasic relationship with a BP rising at 0.28 mm Hg/mm Hg of ICP, for ICP up to 32 mm Hg, and 0.9 mm Hg/mm Hg of ICP for ICP from 33 to 55 mm Hg, and falling sharply with rising ICP for ICP >55 mm Hg. Conclusions Patients with head injury appear to have a near normal distribution of blood pressure readings that are skewed towards higher values. The relationship between BP and ICP may be triphasic. PMID:17138594

Fetal thoracic measurements in prenatal diagnosis of Jeune syndrome.

PubMed

Das, Bibhuti B; Nagaraj, Anasuya; Fayemi, Ayodeji; Rajegowda, Benamanahalli K; Giampietro, Philip F

2002-01-01

We describe prenatal sonographic findings in a 34-week fetus with Jeune syndrome or asphyxiating thoracic dystrophy (ATD). The long bones measured were less than third percentile; the thoracic circumference (TC) measured 216 mm (< 2.5th percentile); the abdominal circumference (AC) measured 303.5 mm (50th-75th percentiles) and the rib cage perimeter (RCP) measured was 98 mm. The TC/AC was 0.70 (normal, 0.85) and the RCP/TC was 0.45 (normal, 0.68). Following birth diagnosis of Jeune syndrome was made based on radiographic analysis, which was subsequently confirmed by clinical and postmortem examination. This case highlights the utility of both TC/AC and RCP/TC in diagnosis of ATD and other skeletal dysplasias associated with a small thorax.

Modified floating-zone growth of organic single crystals

NASA Astrophysics Data System (ADS)

Kou, S.; Chen, C. P.

1994-04-01

For organic materials floating-zone crystal growth is superior to other melt growth processes in two significant respects: (1) the absence of crucible-induced mechanical damage and (2) minimum heating-induced chemical degradation. Due to the rather low surface tension of organic melts, however, floating-zone crystal growth under normal gravity has not been possible so far but microgravity is ideal for such a purpose. With the help of a modified floating-zone technique, organic single crystals of small cross-sections were test grown first under normal gravity. These small crystals were round and rectangular single crystals of benzil and salol, up to about 7 cm long and 6 mm in diameter or 9 mm × 3 mm in cross-section.

Larger core size has superior technical and analytical accuracy in bladder tissue microarray.

PubMed

Eskaros, Adel Rh; Egloff, Shanna A Arnold; Boyd, Kelli L; Richardson, Joyce E; Hyndman, M Eric; Zijlstra, Andries

2017-03-01

The construction of tissue microarrays (TMAs) with cores from a large number of paraffin-embedded tissues (donors) into a single paraffin block (recipient) is an effective method of analyzing samples from many patient specimens simultaneously. For the TMA to be successful, the cores within it must capture the correct histologic areas from the donor blocks (technical accuracy) and maintain concordance with the tissue of origin (analytical accuracy). This can be particularly challenging for tissues with small histological features such as small islands of carcinoma in situ (CIS), thin layers of normal urothelial lining of the bladder, or cancers that exhibit intratumor heterogeneity. In an effort to create a comprehensive TMA of a bladder cancer patient cohort that accurately represents the tumor heterogeneity and captures the small features of normal and CIS, we determined how core size (0.6 vs 1.0 mm) impacted the technical and analytical accuracy of the TMA. The larger 1.0 mm core exhibited better technical accuracy for all tissue types at 80.9% (normal), 94.2% (tumor), and 71.4% (CIS) compared with 58.6%, 85.9%, and 63.8% for 0.6 mm cores. Although the 1.0 mm core provided better tissue capture, increasing the number of replicates from two to three allowed with the 0.6 mm core compensated for this reduced technical accuracy. However, quantitative image analysis of proliferation using both Ki67+ immunofluorescence counts and manual mitotic counts demonstrated that the 1.0 mm core size also exhibited significantly greater analytical accuracy (P=0.004 and 0.035, respectively, r 2 =0.979 and 0.669, respectively). Ultimately, our findings demonstrate that capturing two or more 1.0 mm cores for TMA construction provides superior technical and analytical accuracy over the smaller 0.6 mm cores, especially for tissues harboring small histological features or substantial heterogeneity.

SU-E-I-56: Diagnostic Lead Apron Radiation Exposure Comparison Between Manufacture-Stated and Measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Syh, J; Patel, B; Syh, J

2015-06-15

Purpose: Several vendors of diagnostic lead apron used routinely in radiology/fluoroscopy claim to manufacture 0.5 mm lead equivalent shielding. The purpose of this investigation was to address the concern of the weight of lead aprons versus the radiation protection they provide. Methods: Seven diagnostic lead aprons were measured and compared for their radiation transmission and attenuation characteristics. The measurements were performed on a Philips Integris. Two settings were used, normal (76 kVp, 14.3 mA) and high (110 kVp, 12.3 mA) to represent typical patient and large patient thickness. Plastic water was placed on the table to represent patient scatter. Amore » Capintec PM-500 ion chamber was placed at approximate chest height where hospital personnel would stand. An uncovered, i.e. lead-unhindered, ion chamber reading was taken to establish the baseline reading of an unprotected personnel. The ion chamber was then wrapped with 0.5mm 99.9% pure Pb material to establish the measurement reading when a diagnostic lead apron attenuates as adequately as 0.5mm Pb. The lead aprons were measured one at a time with the ion chamber fully covered and enclosed within the aprons. Results: On Normal fluoroscopy setting, the 0.5mm pure Pb showed a transmission of 0.4%. No aprons showed a transmission value as low as 0.5mm Pb. The lowest transmission value measured from the aprons was 2.0%, having a 1.5% higher transmission than pure lead. On High fluoroscopy setting, the lowest apron transmission measurement was at 2.8%, which was comparable to the 0.5mm pure Pb which gave a transmission of 3.0%. Conclusion: At Normal fluoroscopy setting, the 0.5mm Pb provided an attenuation that could not be matched by any apron measured. At High fluoroscopy setting, only one apron exhibited comparable transmission values as 0.5mm pure Pb.« less

Evaluation of chronic inflammatory demyelinating polyneuropathy: 3D nerve-sheath signal increased with inked rest-tissue rapid acquisition of relaxation enhancement imaging (3D SHINKEI).

PubMed

Hiwatashi, Akio; Togao, Osamu; Yamashita, Koji; Kikuchi, Kazufumi; Ogata, Hidenori; Yamasaki, Ryo; Yoneyama, Masami; Kira, Jun-Ichi; Honda, Hiroshi

2017-02-01

To evaluate the usefulness of 3D nerve-sheath signal increased with inked rest-tissue rapid acquisition of relaxation enhancement imaging (SHINKEI) in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). This institutional review board-approved retrospective study included 14 CIDP patients and nine normal subjects. The signal-to-noise ratio (SNR), contrast ratio (CR), and the size of the cervical ganglions and roots were measured by two raters. The SNRs of the ganglions and roots were larger in patients with CIDP (9.55 ± 3.87 and 9.81 ± 3.64) than in normal subjects (7.21 ± 2.42 and 5.70 ± 2.14, P < 0.0001, respectively). The CRs of the ganglions and roots were larger in patients with CIDP (0.77 ± 0.08 and 0.68 ± 0.12) than in normal subjects (0.72 ± 0.07 and 0.53 ± 0.11, P < 0.0001, respectively). The sizes of the ganglions and the roots were larger in patients with CIDP (6.44 ± 1.61 mm and 4.89 ± 1.94 mm) than in normal subjects (5.24 ± 1.02 mm and 3.39 ± 0.80 mm, P < 0.0001, respectively). Patients with CIDP could be distinguished from controls on 3D SHINKEI. • 3D SHINKEI could visualize brachial plexus with high spatial resolution. • CIDP patients showed increased SNR, CR, and the size of brachial plexus. • 3D SHINKEI could discriminate CIDP patients from normal subjects.

A survey of blood pressure in Lebanese children and adolescence

PubMed Central

Merhi, Bassem Abou; Al-Hajj, Fatima; Al-Tannir, Mohamad; Ziade, Fouad; El-Rajab, Mariam

2011-01-01

Background: Blood pressure varies between populations due to ethnic and environmental factors. Therefore, normal blood pressure values should be determined for different populations. Aims: The aim of this survey was to produce blood pressure nomograms for Lebanese children in order to establish distribution curves of blood pressure by age and sex. Subjects and Methods: We conducted a survey of blood pressure in 5710 Lebanese schoolchildren aged 5 to 15 years (2918 boys and 2792 girls), and studied the distribution of systolic and diastolic blood pressure in these children and adolescents. Blood pressure was measured with a mercury sphygmomanometer using a standardized technique. Results: Both systolic and diastolic blood pressure had a positive correlation with weight, height, age, and body mass index (r= 0.648, 0.643, 0.582, and 0.44, respectively) (P < .001). There was no significant difference in the systolic and diastolic blood pressure in boys compared to girls of corresponding ages. However, the average annual increase in systolic blood pressure was 2.86 mm Hg in boys and 2.63 mm Hg in girls, whereas the annual increase in diastolic blood pressure was 1.72 mm Hg in boys and 1.48 mm Hg in girls. The prevalence of high and high-normal blood pressure at the upper limit of normal (between the 90th and 95th percentile, at risk of future hypertension if not managed adequately), was 10.5% in boys and 6.9% in girls, with similar distributions among the two sexes. Conclusions: We present the first age-specific reference values for blood pressure of Lebanese children aged 5 to 15 years based on a good representative sample. The use of these reference values should help pediatricians identify children with normal, high-normal and high blood pressure. PMID:22540059

A survey of blood pressure in Lebanese children and adolescence.

PubMed

Merhi, Bassem Abou; Al-Hajj, Fatima; Al-Tannir, Mohamad; Ziade, Fouad; El-Rajab, Mariam

2011-01-01

Blood pressure varies between populations due to ethnic and environmental factors. Therefore, normal blood pressure values should be determined for different populations. The aim of this survey was to produce blood pressure nomograms for Lebanese children in order to establish distribution curves of blood pressure by age and sex. We conducted a survey of blood pressure in 5710 Lebanese schoolchildren aged 5 to 15 years (2918 boys and 2792 girls), and studied the distribution of systolic and diastolic blood pressure in these children and adolescents. Blood pressure was measured with a mercury sphygmomanometer using a standardized technique. Both systolic and diastolic blood pressure had a positive correlation with weight, height, age, and body mass index (r= 0.648, 0.643, 0.582, and 0.44, respectively) (P < .001). There was no significant difference in the systolic and diastolic blood pressure in boys compared to girls of corresponding ages. However, the average annual increase in systolic blood pressure was 2.86 mm Hg in boys and 2.63 mm Hg in girls, whereas the annual increase in diastolic blood pressure was 1.72 mm Hg in boys and 1.48 mm Hg in girls. The prevalence of high and high-normal blood pressure at the upper limit of normal (between the 90(th) and 95(th) percentile, at risk of future hypertension if not managed adequately), was 10.5% in boys and 6.9% in girls, with similar distributions among the two sexes. We present the first age-specific reference values for blood pressure of Lebanese children aged 5 to 15 years based on a good representative sample. The use of these reference values should help pediatricians identify children with normal, high-normal and high blood pressure.

Two stage ear/microtia reconstruction using costal cartilage.

PubMed

Balaji, S M

2015-01-01

Reconstruction of Grade III microtia is a challenging entity in maxillofacial esthetic rehabilitation. Several advocacies and philosophies exist in this field. The aim of the manuscript is to present a single South Indian Experience with Ear reconstruction among South Indian Population. Retrospective analysis of unilateral Grade III microtia reconstruction was performed. Using a set of predefined inclusion and exclusion criteria, the population was selected. Outcome measures in terms of the ear size, auriculocephalic angle, and the conchal depth were measured in the reconstructed and normal side. Descriptive statistics is presented. Twenty-four patients formed the study group and had undergone the classical two-stage reconstruction in a similar fashion. The mean ear size in normal side was 65.8 ± 2.8 mm whereas on the reconstructed side, it was 61.3 ± 5.8 mm. The center's technique achieved above 75% similarity as that of the other normal ear. The mean auriculocephalic angle was 44.6 ± 5.2° whereas for the surgically reconstructed ear, it was 41.9 ± 2.6°. Overall, in these patients, we achieved a 79.94% similarity of auriculocephalic angle in the reconstructed ear as compared to the normal auricle. The conchal depth was 19.2 ± 2.1 mm and 16.6 ± 1.9 mm for normal and reconstructed ear, respectively. In terms of conchal depth, the present study group showed an achievement of 82.88% of accuracy even after a prolonged follow-up. The center employs a classic two stage reconstruction with a customized prosthesis that helps to avoid the loss of projection geometry and minimizes adhesion, infection, and early loss of structural stability.

[An occupational physician-pharmacist cooperative management for hypertension by the use of educational letters and posters].

PubMed

Tobari, Hiroko; Yamagishi, Kazumasa; Iso, Hiroyasu

2011-05-01

To provide an occupational physician-pharmacist cooperative management for hypertension, we aimed to improve blood pressure (BP) control for workers with high-normal BP or hypertension. Health checkups were performed from May 2005 to May 2008 for male professional grooms and exercise riders aged 20-69 years working at Miho Training Center, the largest racing-horse training facility in Japan. An occupational physician-pharmacist cooperative hypertension management was performed from Jan 2007 to Mar 2008, including the use of posters at the work site and letters to employers and the subjects who were diagnosed as having high-normal BP (office systolic/diastolic BPs 130-139 and/or 85-89 mmHg) or hypertension (≥ 140 and/or 90 mmHg) twice during 2005-2006 examinations. The observational study examined BP measurements before and after the hypertension management. We analyzed 232 participants in the 2008 Nov examination with had high-normal BP or hypertension in both of 2005 and 2006 Nov examinations. Office systolic and diastolic BP decreased after the hypertension management by the use of educational letters and posters (-3.1 mmHg; p<0.001, -1.5 mmHg; p=0.02). The prevalence of workers with high-normal BP and hypertension also decreased after those activities (-15% and -7%; p<0.001). The subjects who started or continued the antihypertensive medication were more likely to show reductions in office BP and body mass index than those who received no treatment. An occupational physician-pharmacist cooperated hypertension management by the use of educational letters and posters may improve BP control for subjects with high-normal BP or hypertension.

Second trimester fetal nasal bone length in a low-risk Turkish population.

PubMed

Yanik, Filiz Fatma; Eroglu, Derya; Baser, Eralp; Dursun, Polat; Karakaya, Burcu Kisa

2011-10-01

To define normal values of second trimester fetal nasal bone length (NBL) in a low-risk Turkish population. Prenatal records of singleton fetuses who underwent second trimester ultrasonographic examination in the 16 to 23 weeks of pregnancy were retrospectively analyzed for NBL and biometric measurements (BPD, FL and HL). The relationship among NBL and gestational age (GA), biparietal diameter (BPD), femur length (FL) and humerus length (HL) was determined. Additionally, percentile values of NBL for each gestational week were provided. A total of 1467 fetuses were included in this study. There was a significant linear association among NBL and GA (R(2) = 0.709), BPD (R(2) = 0.752), FL (R(2) = 0.742) and HL (R(2) = 0.747). Fifth percentile values of fetal NBL were 3.11 mm for 16th, 3.50 mm for 17th, 3.70 mm for 18th, 4.10 mm for 19th, 4.50 mm for 20th, 4.62 mm for 21st, 5.24 mm for 22nd and 5.37 mm for 23rd gestational weeks. The study provides normal ranges of NBL between 16 and 23 weeks of pregnancy in a low-risk Turkish population. Future studies with larger sample sizes including pregnancies carrying high risk for aneuploidy are needed to define cut-off values for NBL. Copyright © 2011 John Wiley & Sons, Ltd.

Volumetric-modulated Arc Therapy Lung Stereotactic Body Radiation Therapy Dosimetric Quality Assurance: A Comparison between Radiochromic Film and Chamber Array.

PubMed

Colodro, Juan Fernando Mata; Berná, Alfredo Serna; Puchades, Vicente Puchades; Amores, David Ramos; Baños, Miguel Alcaraz

2017-01-01

The aim of this work is to verify the use of radiochromic film in the quality assurance (QA) of volumetric-modulated arc therapy (VMAT) lung stereotactic body radiation therapy (SBRT) plans and compare the results with those obtained using an ion chamber array. QA was performed for 14 plans using a two-dimensional-array seven29 and EBT3 film. Dose values per session ranged between 7.5 Gy and 18 Gy. The multichannel method was used to obtain a dose map for film. The results obtained were compared with treatment planning system calculated profiles through gamma analysis. Passing criteria were 3%/3 mm, 2%/2 mm and 3%/1.5 mm with maximum and local dose (LD) normalization. Mean gamma passing rate (GPR) (percentage of points presenting a gamma function value of <1) was obtained and compared. Calibration curves were obtained for each color channel within the dose range 0-16 Gy. Mean GPR values for film were >98.9% for all criteria when normalizing per maximum dose. When using LD, normalization was >92.7%. GPR values for the array were lower for all criteria; this difference being statistically significant when normalizing at LD, reaching 12% for the 3%/1.5 mm criterion. Both detectors provide satisfactory results for the QA of plans for VMAT lung SBRT. The film provided greater mean GPR values, afforded greater spatial resolution and was more efficient overall.

Volumetric-modulated Arc Therapy Lung Stereotactic Body Radiation Therapy Dosimetric Quality Assurance: A Comparison between Radiochromic Film and Chamber Array

PubMed Central

Colodro, Juan Fernando Mata; Berná, Alfredo Serna; Puchades, Vicente Puchades; Amores, David Ramos; Baños, Miguel Alcaraz

2017-01-01

Introduction: The aim of this work is to verify the use of radiochromic film in the quality assurance (QA) of volumetric-modulated arc therapy (VMAT) lung stereotactic body radiation therapy (SBRT) plans and compare the results with those obtained using an ion chamber array. Materials and Methods: QA was performed for 14 plans using a two-dimensional-array seven29 and EBT3 film. Dose values per session ranged between 7.5 Gy and 18 Gy. The multichannel method was used to obtain a dose map for film. Results: The results obtained were compared with treatment planning system calculated profiles through gamma analysis. Passing criteria were 3%/3 mm, 2%/2 mm and 3%/1.5 mm with maximum and local dose (LD) normalization. Mean gamma passing rate (GPR) (percentage of points presenting a gamma function value of <1) was obtained and compared. Calibration curves were obtained for each color channel within the dose range 0–16 Gy. Mean GPR values for film were >98.9% for all criteria when normalizing per maximum dose. When using LD, normalization was >92.7%. GPR values for the array were lower for all criteria; this difference being statistically significant when normalizing at LD, reaching 12% for the 3%/1.5 mm criterion. Conclusion: Both detectors provide satisfactory results for the QA of plans for VMAT lung SBRT. The film provided greater mean GPR values, afforded greater spatial resolution and was more efficient overall. PMID:28974858

Biomechanical measurements of stiffness and strength for five types of whole human and artificial humeri.

PubMed

Aziz, Mina S R; Nicayenzi, Bruce; Crookshank, Meghan C; Bougherara, Habiba; Schemitsch, Emil H; Zdero, Radovan

2014-05-01

The human humerus is the third largest longbone and experiences 2-3% of all fractures. Yet, almost no data exist on its intact biomechanical properties, thus preventing researchers from obtaining a full understanding of humerus behavior during injury and after being repaired with fracture plates and nails. The aim of this experimental study was to compare the biomechanical stiffness and strength of "gold standard" fresh-frozen humeri to a variety of humerus models. A series of five types of intact whole humeri were obtained: human fresh-frozen (n = 19); human embalmed (n = 18); human dried (n = 15); artificial "normal" (n = 12); and artificial "osteoporotic" (n = 12). Humeri were tested under "real world" clinical loading modes for shear stiffness, torsional stiffness, cantilever bending stiffness, and cantilever bending strength. After removing geometric effects, fresh-frozen results were 585.8 ± 181.5 N/mm2 (normalized shear stiffness); 3.1 ± 1.1 N/(mm2 deg) (normalized torsional stiffness); 850.8 ± 347.9 N/mm2 (normalized cantilever stiffness); and 8.3 ± 2.7 N/mm2 (normalized cantilever strength). Compared to fresh-frozen values, statistical equivalence (p ≥ 0.05) was obtained for all four test modes (embalmed humeri), 1 of 4 test modes (dried humeri), 1 of 4 test modes (artificial "normal" humeri), and 1 of 4 test modes (artificial "osteoporotic" humeri). Age and bone mineral density versus experimental results had Pearson linear correlations ranging from R = -0.57 to 0.80. About 77% of human humeri failed via a transverse or oblique distal shaft fracture, whilst 88% of artificial humeri failed with a mixed transverse + oblique fracture. To date, this is the most comprehensive study on the biomechanics of intact human and artificial humeri and can assist researchers to choose an alternate humerus model that can substitute for fresh-frozen humeri.

SU-F-J-153: ACR MRI Phantom Test On a 1.5T MR-Simulator with Flexible Coils Setting and Performance Comparison to Volumetric Head Coil Setting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuan, J; Wong, O; Cheung, K

Purpose: To accommodate head-and-neck (HN) RT simulation scan with immobilization, sub-optimized flexible radiofrequency coils have to be used on an MR-sim rather than a volumetric head coil for diagnostic radiological (DR) applications. In this study, we present and compare ACR MRI phantom test with flexible coils setting (RT-setting) and volumetric head coil setting (DR-setting). Methods: Two 8-channel array coils were wrapped close to an ACR MRI phantom placed on a flat couch-top in RT-setting for acquisition. ACR MRI phantom tests were conducted 10 times for each setting on a 1.5T MR-sim. Sagittal localizer (TE/TR=20/200ms), axial T1 (TE/TR=20/500ms) and T2 scansmore » (2TEs/TR=20,80/2000ms) were acquired (NEX=1). Acqusition and image analysis were conducted following ACR guidelines. Extra 10 RT-setting acquisitions were obtained by enabling prescan normalization. Results: For RT-setting without prescan normalization, all tests passed the ACR recommended criteria but image intensity uniformity. Geometric accuracy was 147.8±0.3mm and 191.0±0.4mm. Spatial resolution was 0.9mm. Slice thickness was 5.2mm±0.1mm (T1) and 5.1±0.1mm (T2). Slice position accuracy was 1.4±0.6mm, −2.2±0.3mm (T1), and 1.5±0.2mm, −2.2±0.2mm (T2). Image uniformity was 80.6%±2.6% (T1) and 80.2%±3.1% (T2) (criteria: ≥87.5% for 1.5T). Ghosting ratio was 0.0006±0.0004. Low contrast detectability was 30.7±1.7 (T1) and 22.6±3.0 (T2). Image uniformity (91.4%±4.2% and 91.8%±4.3%) and low contrast detectability (36.5±1.4 and 31.6±2.2) of DR-setting were better than RT-setting. Prescan normalization substantially improved image uniformity to 93.4%±0.2% and 93.4%±0.3%, but slightly compromised ghosting (0.0033±0.0004) and spatial resolution (0.9mm or 1.0mm) for RT-setting. Conclusion: Flexible coils setting for HN-RT simulation scan could successfully pass ACR criteria (prescan normalization enabled) and generally achieve comparable performance to volumetric coil setting, although compromise on low contrast detectability was observed probably due to the lower signal-to-noise ratio of the flexible coils. Our results could also serve as a reference baseline of high-field MR-sim QA performance under ACR guideline.« less

[Effect of maximum blood pressure fluctuation on prognosis of patients with acute ischemic stroke within 24 hours after hospital admission].

PubMed

Wang, H; Tang, Y; Zhang, Y; Xu, K; Zhao, J B

2018-05-10

Objective: To investigate the relationship between the maximum blood pressure fluctuation within 24 hours after admission and the prognosis at discharge. Methods: The patients with ischemic stroke admitted in Department of Neurology of the First Affiliated Hospital of Harbin Medical University within 24 hours after onset were consecutively selected from April 2016 to March 2017. The patients were grouped according to the diagnostic criteria of hypertension. Ambulatory blood pressure of the patients within 24 hours after admission were measured with bedside monitors and baseline data were collected. The patients were scored by NIHSS at discharge. The relationships between the maximum values of systolic blood pressure (SBP) or diastolic blood pressure (DBP) and the prognosis at discharge were analyzed. Results: A total of 521 patients with acute ischemic stroke were enrolled. They were divided into normal blood pressure group (82 cases) and hypertension group(439 cases). In normal blood pressure group, the maximum values of SBP and DBP were all in normal distribution ( P >0.05). The maximum value of SBP fluctuation was set at 146.6 mmHg. After adjustment for potential confounders, the OR for poor prognosis at discharge in patients with SBP fluctuation ≥146.6 mmHg was 2.669 (95 %CI : 0.594-11.992) compared with those with SBP fluctuation <146.6 mmHg. The maximum value of DBP fluctuation was set at 90.0 mmHg, and the adjusted OR for poor prognosis at discharge in patients with DBP fluctuation ≥90.0 mmHg was 0.416 (95 %CI : 0.087-1.992) compared with those with DBP fluctuation <90.0 mmHg. In hypertension group, the maximum values of SBP and DBP were not in normal distribution ( P <0.05). The maximum value of SBP fluctuation was set at median 171.0 mmHg. After adjustment for the confounders, the greater the maximum of SBP, the greater the risk of poor prognosis at discharge was, the OR was 1.636 (95 %CI : 1.014-2.641). The maximum value of DBP fluctuation was set at median 98.0 mmHg. After adjustment for the confounders, the greater the maximum of DBP, the greater the risk of poor prognosis at discharge was, the OR was 1.645 (95 %CI : 1.003-2.697). Conclusion: In acute ischemic stroke patients with normal blood pressure at admission, the maximum values of SBP and DBP within 24 hours after admission had no relationship with prognosis at discharge. In acute ischemic stroke patients with hypertension at admission, the maximum values of SBP and DBP within 24 hours after admission were associated with poor prognosis at discharge.

Diagnostic value of diffusion weighted MRI and ADC in differential diagnosis of cavernous hemangioma of the liver.

PubMed

Tokgoz, Ozlem; Unlu, Ebru; Unal, Ilker; Serifoglu, Ismail; Oz, Ilker; Aktas, Elif; Caglar, Emrah

2016-03-01

To investigate the use of diffusion weighted magnetic resonance imaging (DWI) and the apparent diffusion coefficient (ADC) values in the diagnosis of hemangioma. The study population consisted of 72 patients with liver masses larger than 1 cm (72 focal lesions). DWI examination with a b value of 600 s/mm2 was carried out for all patients. After DWI examination, an ADC map was created and ADC values were measured for 72 liver masses and normal liver tissue (control group). The average ADC values of normal liver tissue and focal liver lesions, the "cut-off" ADC values, and the diagnostic sensitivity and specificity of the ADC map in diagnosing hemangioma, benign and malignant lesions were researched. Of the 72 liver masses, 51 were benign and 21 were malignant. Benign lesions comprised 38 hemangiomas and 13 simple cysts. Malignant lesions comprised 9 hepatocellular carcinomas, and 12 metastases. The highest ADC values were measured for cysts (3.782±0.53×10(-3) mm(2)/s) and hemangiomas (2.705±0.63×10(-3) mm(2)/s). The average ADC value of hemangiomas was significantly higher than malignant lesions and the normal control group (p<0.001). The average ADC value of cysts were significantly higher when compared to hemangiomas and normal control group (p<0.001). To distinguish hemangiomas from malignant liver lesions, the "cut-off" ADC value of 1.800×10(-3) mm(2)/s had a sensitivity of 97.4% and a specificity of 90.9%. To distinguish hemangioma from normal liver parenchyma the "cut-off" value of 1.858×10(-3) mm(2)/s had a sensitivity of 97.4% and a specificity of 95.7%. To distinguish benign liver lesions from malignant liver lesions the "cut-off" value of 1.800×10(-3) mm(2)/s had a sensitivity of 96.1% and a specificity of 90.0%. DWI and quantitative measurement of ADC values can be used in differential diagnosis of benign and malignant liver lesions and also in the diagnosis and differentiation of hemangiomas. When dynamic examination cannot distinguish cases with vascular metastasis and lesions from hemangioma, DWI and ADC values can be useful in the primary diagnosis and differential diagnosis. The technique does not require contrast material, so it can safely be used in patients with renal failure.

Stimulated Rayleigh-Bragg scattering in a three-photon absorbing medium and its phase-conjugation property

NASA Astrophysics Data System (ADS)

He, Guang S.; Zheng, Qingdong; Prasad, Paras N.

2007-05-01

We show that the backward-stimulated Rayleigh-Bragg scattering (SRBS) can be efficiently generated in a three-photon absorbing medium. Compared with all other known stimulated (such as Brillouin and Raman) scattering effects, the observed effect exhibits the following three features: (i) no frequency shift, (ii) a lower pump threshold, and (iii) no critical requirement for pump spectral linewidths within a range of Δv¯≤1cm-1. The specific nonlinear scattering medium is a three-photon absorbing chromophore solution (PRL-OT04 in chloroform), pumped by 1064nm laser pulses of nanoseconds duration but with three different spectral linewidths. The mechanism for generating backward SRBS in a three-photon active medium is the formation of a stationary Bragg grating enhanced by three-photon-absorption-associated refractive index changes. A superior optical phase-conjugation property of the backward SRBS beam has been experimentally demonstrated by employing two different optical setups. In both cases, a specially introduced aberration influence of 4-5 mrad can be basically removed by the backward SRBS beam that retains a much smaller beam divergence of ≤0.4 mrad.

A Study of Gamma-Ray Exposure of Cu-SiO2 Programmable Metallization Cells

NASA Astrophysics Data System (ADS)

Chen, W.; Barnaby, H. J.; Kozicki, M. N.; Edwards, A. H.; Gonzalez-Velo, Y.; Fang, R.; Holbert, K. E.; Yu, S.; Yu, W.

2015-12-01

The Cu-SiO2 based programmable metallization cell (PMC) is a promising alternative to the Ag-chalcogenide glass PMC because of its low power consumption and CMOS-compatibility. Understanding its total ionizing dose (TID) response helps in assessing the reliability of this technology in ionizing radiation environments and benefits its expansion in the space electronics market. In this paper, the impacts of TID on the switching characteristics of Cu-SiO2 PMC are investigated for the first time. The devices were step irradiated with 60Co gamma-rays to a maximum dose of 7.1 Mrad ( SiO2). The results show that gamma-ray irradiation has a negligible impact on the virgin-state and on-state resistance of Cu-SiO2 PMCs. The off-state resistance slightly decreases after the first 1.5 Mrad( SiO2) of exposure, but this reduction saturates after higher levels of TID. Other switching characteristics such as the set voltage, multilevel switching capability and endurance were also studied, all of which did not show observable changes after gamma-ray radiation. The immunity to ionizing radiation is attributed to the suppression of the photo-doping process.

Cassini infrared Fourier spectroscopic investigation

NASA Astrophysics Data System (ADS)

Kunde, Virgil G.; Ade, Peter A.; Barney, Richard D.; Bergman, D.; Bonnal, Jean-Francois; Borelli, R.; Boyd, D.; Brasunas, John C.; Brown, G.; Calcutt, S. B.; Carroll, F.; Courtin, R.; Cretolle, Jacky; Crooke, Julie A.; Davis, Martin A.; Edberg, S.; Fettig, R.; Flasar, M.; Glenar, David A.; Graham, S.; Hagopian, John G.; Hakun, C. F.; Hayes, Patricia A.; Herath, L.; Horn, Linda; Jennings, Donald E.; Karpati, G.; Kellebenz, C.; Lakew, Brook; Lindsay, J.; Lohr, J.; Lyons, James J.; Martineau, Robert J.; Martino, Anthony J.; Matsumura, M.; McCloskey, J.; Melak, T.; Michel, G.; Morell, Armando; Mosier, C.; Pack, L.; Plants, M.; Robinson, D.; Rodriguez, Louis; Romani, Paul; Schaefer, W. J.; Schmidt, Steve; Trujillo, C.; Vellacott, Tim; Wagner, K.; Yun, D.

1996-10-01

The composite infrared spectrometer (CIRS) is a remote sensing instrument to be flown on the Cassini orbiter. CIRS will retrieve vertical profiles of temperature and gas composition for the atmospheres of Titan and Saturn, from deep in their tropospheres to high in their stratospheres. CIRS will also retrieve information on the thermal properties and composition of Saturn's rings and Saturnian satellites. CIRS consists of a pair of Fourier Transform Spectrometers (FTSs) which together cover the spectral range from 10-1400 cm-1 with a spectral resolution up to 0.5 cm-1. The two interferometers share a 50 cm beryllium Cassegrain telescope. The far-infrared FTS is a polarizing interferometer covering the 10-600 cm-1 range with a pair of thermopile detectors, and a 3.9 mrad field of view. The mid-infrared FTS is a conventional Michelson interferometer covering 200-1400 cm-1 in two spectral bandpasses: 600-1100 cm- 1100-1400 cm(superscript -1 with a 1 by 10 photovoltaic HgCdTe array. Each pixel of the arrays has an approximate 0.3 mrad field of view. The HgCdTe arrays are cooled to approximately 80K with a passive radiative cooler.

HARP targets pion production cross section and yield measurements: Implications for MiniBooNE neutrino flux

NASA Astrophysics Data System (ADS)

Wickremasinghe, Don Athula Abeyarathna

The prediction of the muon neutrino flux from a 71.0 cm long beryllium target for the MiniBooNE experiment is based on a measured pion production cross section which was taken from a short beryllium target (2.0 cm thick - 5% nuclear interaction length) in the Hadron Production (HARP) experiment at CERN. To verify the extrapolation to our longer target, HARP also measured the pion production from 20.0 cm and 40.0 cm beryllium targets. The measured production yields on targets of 50% and 100% nuclear interaction lengths in the kinematic rage of momentum from 0.75 GeV/c to 6.5 GeV/c and the range of angle from 30 mrad to 210 mrad are presented along with an update of the short target cross sections. The best fitted extended Sanford-Wang (SW) model parameterization for updated short beryllium target positive pion production cross section is presented. Yield measurements for all three targets are also compared with that from the Monte Carlo predictions in the MiniBooNE experiment for different SW parameterization. The comparisons of muon neutrino flux predictions for updated SW model is presented.

Evaluation of a rebound tonometer (Tonovet) in clinically normal cat eyes.

PubMed

Rusanen, Elina; Florin, Marion; Hässig, Michael; Spiess, Bernhard M

2010-01-01

To determine the accuracy of and to establish reference values for a rebound tonometer (Tonovet) in normal feline eyes, to compare it with an applanation tonometer (Tonopen Vet) and to evaluate the effect of topical anesthesia on rebound tonometry. Six enucleated eyes were used to compare both tonometers with direct manometry. Intraocular pressure (IOP) was measured in 100 cats to establish reference values for rebound tonometry. Of these, 22 cats were used to compare rebound tonometry with and without topical anesthesia and 33 cats to compare the rebound and applanation tonometers. All evaluated eyes were free of ocular disease. Both tonometers correlated well with direct manometry. The best agreement with the rebound tonometer was achieved between 25-50 mmHg. The applanation tonometer was accurate at pressures between 0 and 30 mmHg. The mean IOP in clinically normal cats was 20.74 mmHg with the rebound tonometer and 18.4 mmHg with the applanation tonometer. Topical anesthesia did not significantly affect rebound tonometry. As the rebound tonometer correlated well with direct manometry in the clinically important pressure range and was well tolerated by cats, it appears suitable for glaucoma diagnosis. The mean IOP obtained with the rebound tonometer was 2-3 mmHg higher than that measured with the applanation tonometer. This difference is within clinically acceptable limits, but indicates that the same type of tonometer should be used in follow-up examinations in a given cat.

Dynamic changes of the intraocular pressure and the pressure of cerebrospinal fluid in nonglaucomatous neurological patients.

PubMed

González-Camarena, Pedro Iván; San-Juan, Daniel; González-Olhovich, Irene; Rodríguez-Arévalo, David; Lozano-Elizondo, David; Trenado, Carlos; Anschel, David J

2017-03-01

To describe the dynamic changes of the intraocular pressure (IOP) and intracranial pressure (ICP) with normal or pathological values (intracranial hypertension) in nonglaucomatous neurological patients during lumbar punction (LP). Case-control study, prospective measurement of tonometry in both groups referred for LP. Intraocular pressure, ICP and translaminar pressure difference (TPD) were compared pre- and post-LP. Thirty-six patients (72 eyes) with mean age of 38.5 (16-64) years and BMI of 26.81 kg/m 2 were analysed. The initial mean ICP was 12.81 (± 6.6) mmHg. The mean TPD before and after the LP was 1.48 mmHg and 0.65 mmHg, respectively. The mean IOP of both eyes decreased to 0.8 mmHg post-LP in patients with pathological ICP (p = 0.0193) and normal ICP (p = 0.006). We found a statistically significant decrease of the IOP post-LP compared to the pre-LP in both groups, being higher in patients with pathological ICP. There were no significant differences of the IOP in patients with normal versus pathological ICP pre-LP/post-LP; neither was found a correlation between ICP and IOP. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

The Relationship Between Cognitive Functioning and the JNC-8 Guidelines for Hypertension in Older Adults

PubMed Central

Hajjar, Ihab M.; Dunn, Callie B.; Levey, Allan I.; Wharton, Whitney

2017-01-01

Background: Guidelines for hypertension treatment by the Eighth Joint National Committee (JNC-8) in 2014 recommended a target systolic blood pressure (BP) of <150/<90 mmHg in persons older than 60 years, in contrast to the 2003 JNC-7 recommendations of systolic BP <140 mmHg. This study evaluated the implications of raising the BP target on cognitive functioning and conversion from normal cognition to mild cognitive impairment (MCI). Methods: This was a longitudinal study of individuals older than 60 years enrolled in the NIH-NIA Alzheimer’s Disease Centers. All had normal cognition at baseline. 453 participants were taking BP medications and had readings of <140/<90 mmHg at four annual visits (reference group). Two other groups consisted of participants with either systolic BP of 140–149 mmHg (n = 112) or ≥150 mmHg (n = 280) on three or four annual visits. Results: Compared with the reference and the 140–149 mmHg groups, those with BP ≥150 mmHg exhibited poorer cognitive status by Year 4 on the Mini-Mental State Exam, and they had a higher risk of conversion to MCI. The 140–149 mmHg exhibited poorer performance than the reference group on domains assessing attention and executive functioning. In contrast, their performance was not significantly different from those with BP ≥150 mmHg. Conclusions: Persons with BP ≥150 mmHg show a faster global cognitive decline and transition to MCI than those with lower BP readings. However, the poor cognitive performance in the attention and executive functioning domains for the 140–149 mmHg group indicates the need for further research evaluating the newer recommended cutoff. PMID:27678289

Association between the body mass index and the clinical findings in patients with acute heart failure: evaluation of the obesity paradox in patients with severely decompensated acute heart failure.

PubMed

Matsushita, Masato; Shirakabe, Akihiro; Hata, Noritake; Shinada, Takuro; Kobayashi, Nobuaki; Tomita, Kazunori; Tsurumi, Masafumi; Okazaki, Hirotake; Yamamoto, Yoshiya; Asai, Kuniya; Shimizu, Wataru

2017-05-01

Obesity is known to be associated with the development of heart failure (HF). However, the relationship between the body mass index (BMI) and acute HF (AHF) remains to be elucidated. Eight hundred and eight AHF patients were enrolled in this study. The patients were assigned to four groups according to their BMI values: severely thin (n = 11, BMI <16), normal/underweight (n = 579, 16 ≤ BMI <25), overweight (n = 178, 25 ≤ BMI <30) and obese (n = 40, BMI ≥30). The patients in the severely thin group were more likely to be female, have systolic blood pressure (SBP) <100 mmHg and have valvular disease than normal/underweight patients. The patients in the overweight group were significantly younger than those in the normal/underweight, and those in the overweight group were more likely to have SBP ≥140 mmHg and hypertensive heart disease and less likely to have valvular disease than the patients in the normal/underweight group. The prognosis, including all-cause death, was significantly poorer among patients who were severely thin than those who were normal/underweight, overweight and significantly better among those who were overweight than those who were normal/underweight, severely thin and obese patients. A multivariate Cox regression model identified that severely thin [HR: 3.372, 95% confidence interval (CI) 1.362-8.351] and overweight (HR: 0.615, 95% CI 0.391-0.966) were independent predictors of 910-day mortality as the reference of normal/underweight. Overweight patients tended to have SBP ≥140 mmHg and be relatively young, while severely thin patients tended to have SBP <100 mmHg and be female. These factors were associated with a better prognosis of overweight patients and adverse outcomes in severely thin patients. These factors may contribute to the "obesity paradox" in severely decompensated AHF patients.

Electrical and mechanical characteristics of fully transparent IZO thin-film transistors on stress-relieving bendable substrates

NASA Astrophysics Data System (ADS)

Park, Sukhyung; Cho, Kyoungah; Oh, Hyungon; Kim, Sangsig

2016-10-01

In this study, we report the electrical and mechanical characteristics of fully transparent indium zinc oxide (IZO) thin-film transistors (TFTs) fabricated on stress-relieving bendable substrates. An IZO TFT on a stress-relieving substrate can operate normally at a bending radius of 6 mm, while an IZO TFT on a normal plastic substrate fails to operate normally at a bending radius of 15 mm. A plastic island with high Young's modulus embedded on a soft elastomer layer with low Young's modulus plays the role of a stress-relieving substrate for the operation of the bent IZO TFT. The stress and strain distributions over the IZO TFT will be analyzed in detail in this paper.

Ultrasonographic evaluation of tracheal collapse in dogs

PubMed Central

Eom, Kidong; Moon, Kumjung; Seong, Yunsang; Oh, Taeho; Yi, Sungjoon; Lee, Keunwoo

2008-01-01

Tracheal ultrasonography was performed to measure the width of the tracheal ring shadow and to assess the clinical relevance of these measurements for identifying tracheal collapse. The first tracheal ring width (FTRW) and thoracic inlet tracheal ring width (TITRW) were measured on both expiration and inspiration. The mean of the FTRW width (129 dogs) was greater in expiration (10.97 ± 1.02 mm, p = 0.001) than that in inspiration (9.86 ± 1.03 mm). For 51 normal dogs, the mean of the TITRW width was greater in expiration (9.05 ± 1.52 mm, p = 0.001) than in inspiration (8.02 ± 1.43 mm). For 78 tracheal collapse dogs, the mean of the TITRW width was greater in expiration (15.89 ± 1.01 mm, p = 0.001) than in inspiration (14.85 ± 1.17 mm). The TITRW/FTRW ratio of the normal dogs was higher (p = 0.001) in expiration (0.81 ± 0.09) than that in inspiration (0.79 ± 0.10). When compared between the normal and tracheal collapse dogs, the TITRW/FTRW ratio was also increased (p = 0.001) both in expiration (1.54 ± 0.09) and inspiration (1.47 ± 0.08), respectively. Based on these results, the cutoff level of the TITRW/FTRW ratio was statistically analyzed according to the receiver operating characteristic curve and it could be set at 1.16 in expiration and at 1.13 in inspiration. We have demonstrated that tracheal ultrasonography is a useful technique for the evaluation of tracheal collapse and it can be a supportive tool together with the radiographic findings for making the correct diagnosis. PMID:19043316

Long-term changes in body weight are associated with changes in blood pressure levels.

PubMed

Markus, M R P; Ittermann, T; Baumeister, S E; Troitzsch, P; Schipf, S; Lorbeer, R; Aumannn, N; Wallaschofski, H; Dörr, M; Rettig, R; Völzke, H

2015-03-01

Hypertension and obesity are highly prevalent in Western societies. We investigated the associations of changes in body weight with changes in blood pressure and with incident hypertension, incident cardiovascular events, or incident normalization of blood pressure in patients who were hypertensive at baseline, over a 5-year period. Data of men and women aged 20-81 years of the Study of Health in Pomerania were used. Changes in body weight were related to changes in blood pressure by linear regression (n = 1875) adjusted for cofounders. Incident hypertension, incident cardiovascular events, or incident blood pressure normalization in patients who were hypertensive at baseline were investigated using Poisson regression (n = 3280) models. A change of 1 kg in body weight was positively associated with a change of 0.45 mm Hg (95% confidence interval (CI): 0.34-0.55 mm Hg) in systolic blood pressure, 0.32 mm Hg (95% CI: 0.25-0.38 mm Hg) in diastolic blood pressure, and 0.36 mm Hg (95% CI: 0.29-0.43 mm Hg) in mean arterial pressure (all p-values <0.001). A 5% weight loss reduced the relative risk (RR) of incident hypertension (RRs 0.84 (95% CI: 0.79-0.89)) and incident cardiovascular events (RRs 0.81 (95% CI: 0.68-0.98)) and increased the chance of incident blood pressure normalization in patients who were hypertensive at baseline by 15% (95% CI: 7-23%). Absolute and relative changes in body weight are positively associated with changes in blood pressure levels and also affect the risk of cardiovascular events. Copyright © 2014 Elsevier B.V. All rights reserved.

Effect of sedation with detomidine on intraocular pressure with and without topical anesthesia in clinically normal horses.

PubMed

Holve, Dana L

2012-02-01

To determine the effect of sedation with detomidine on intraocular pressure (IOP) in standing horses and whether topical ocular application of anesthetic alters this effect. Clinical trial. 15 clinically normal horses. Horses were assigned to group 1 (n = 7) or 2 (8). Intraocular pressure measurements were obtained at baseline (before sedation) and 10 minutes after IV administration of detomidine (0.02 mg/kg [0.009 mg/lb]). Group 1 horses had an additional IOP measurement at 20 minutes after sedation. For group 2 horses, topical ocular anesthetic was administered 10 minutes prior to baseline IOP measurements. Mean ± SD baseline IOP for horses without topical anesthesia (group 1 horses; IOP, 24.30 ± 3.09 mm Hg) was significantly lower, compared with that of horses with topical anesthesia (group 2 horses; IOP, 30.40 ± 3.25 mm Hg). Compared with baseline values, IOP at 10 minutes after sedation decreased significantly in all horses (by 3.61 ± 1.48 mm Hg and 5.78 ± 4.32 mm Hg in groups 1 and 2, respectively). In group 1 horses, IOP at 10 (20.69 ± 3.45 mm Hg) and 20 (19.96 ± 2.13 mm Hg) minutes after sedation was significantly decreased, compared with baseline values; however, the difference between IOP at 10 versus 20 minutes was not significant. The difference in IOP between group 1 and 2 horses at 10 minutes after sedation was not significant. IV administration of detomidine caused a decrease in IOP in clinically normal horses and may be a safe sedative when performing ocular procedures.

Detection of normal plantar fascia thickness in adults via the ultrasonographic method.

PubMed

Abul, Kadir; Ozer, Devrim; Sakizlioglu, Secil Sezgin; Buyuk, Abdul Fettah; Kaygusuz, Mehmet Akif

2015-01-01

Heel pain is a prevalent concern in orthopedic clinics, and there are numerous pathologic abnormalities that can cause heel pain. Plantar fasciitis is the most common cause of heel pain, and the plantar fascia thickens in this process. It has been found that thickening to greater than 4 mm in ultrasonographic measurements can be accepted as meaningful in diagnoses. Herein, we aimed to measure normal plantar fascia thickness in adults using ultrasonography. We used ultrasonography to measure the plantar fascia thickness of 156 healthy adults in both feet between April 1, 2011, and June 30, 2011. These adults had no previous heel pain. The 156 participants comprised 88 women (56.4%) and 68 men (43.6%) (mean age, 37.9 years; range, 18-65 years). The weight, height, and body mass index of the participants were recorded, and statistical analyses were conducted. The mean ± SD (range) plantar fascia thickness measurements for subgroups of the sample were as follows: 3.284 ± 0.56 mm (2.4-5.1 mm) for male right feet, 3.3 ± 0.55 mm (2.5-5.0 mm) for male left feet, 2.842 ± 0.42 mm (1.8-4.1 mm) for female right feet, and 2.8 ± 0.44 mm (1.8-4.3 mm) for female left feet. The overall mean ± SD (range) thickness for the right foot was 3.035 ± 0.53 mm (1.8-5.1 mm) and for the left foot was 3.053 ± 0.54 mm (1.8-5.0 mm). There was a statistically significant and positive correlation between plantar fascia thickness and participant age, weight, height, and body mass index. The plantar fascia thickness of adults without heel pain was measured to be less than 4 mm in most participants (~92%). There was no statistically significant difference between the thickness of the right and left foot plantar fascia.

Comparison and Optimization of 3.0 T Breast Images Quality of Diffusion-Weighted Imaging with Multiple B-Values.

PubMed

Han, Xiaowei; Li, Junfeng; Wang, Xiaoyi

2017-04-01

Breast 3.0 T magnetic resonance diffusion-weighted imaging (MR-DWI) of benign and malignant lesions were obtained to measure and calculate the signal-to-noise ratio (SNR), signal intensity ratio (SIR), and contrast-to-noise ratio (CNR) of lesions at different b-values. The variation patterns of SNR and SIR were analyzed with different b-values and the images of DWI were compared at four different b-values with higher image quality. The effect of SIR on the differential diagnostic efficiency of benign and malignant lesions was compared using receiver operating characteristic curves to provide a reference for selecting the optimal b-value. A total of 96 qualified patients with 112 lesions and 14 patients with their contralateral 14 normal breasts were included in this study. The single-shot echo planar imaging sequence was used to perform the DWI and a total of 13 b-values were used: 0, 50, 100, 200, 400, 600, 800, 1000, 1200, 1500, 1800, 2000, and 2500 s/mm 2 . On DWI, the suitable regions of interest were selected. The SNRs of normal breasts (SNR normal ), SNR lesions , SIR, and CNR of benign and malignant lesions were measured on DWI with different b-values and calculated. The variation patterns of SNR, SIR, and CNR values on DWI for normal breasts, benign lesions, and malignant lesions with different b-values were analyzed by using Pearson correlation analysis. The SNR and SIR of benign and malignant lesions with the same b-values were compared using t-tests. The diagnostic efficiencies of SIR with different b-values for benign and malignant lesions were evaluated using receiver operating characteristic curves. Breast DWI had higher CNR for b-values ranging from 600 to 1200 s/mm 2 . It had the best CNR at b = 1000 s/mm 2 for the benign lesions and at b = 1200 s/mm 2 for the malignant lesions. The signal intensity and SNR values of normal breasts decreased with increasing b-values, with a negative correlation (r = -0.945, P < 0.01). The mean SNR values of benign and malignant lesions were negatively correlated (r = -0.982 and -0.947, respectively, and P < 0.01), gradually decreasing with increasing b-values. The mean SIR value of benign lesions gradually decreased with increasing b-values, a negative correlation (r = -0.991, P < 0.01). The mean SIR values of malignant lesions gradually increased with increasing b-values between 0 and 1200 s/mm 2 , and gradually decreased with increasing b-values ≥ 1500 s/mm 2 . For b-values of 600, 800, 1000, and 1200 s/mm 2 , the sensitivity and specificity of SIR in identifying benign and malignant lesions gradually increased with increasing b-values, peaking at 1200 s/mm 2 . Breast DWI had higher image quality for b-values ranging from 600 to 1200 s/mm 2 , and was best for b-values ranging from 1000 to 1200 s/mm 2 . The SIR had the highest diagnostic efficiency in differentiating benign and malignant lesions for a b-value of 1200 s/mm 2 . Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Hemoglobin Affinity for Oxygen in the Anginal Syndrome with Normal Coronary Arteriograms

PubMed Central

Vokonas, Pantel S.; Cohn, Peter F.; Klein, Michael D.; Laver, Myron B.; Gorlin, Richard

1974-01-01

Oxyhemoglobin dissociation (OHD) curves were performed on whole blood (WB) from 20 patients with anginal pain, normal hemodynamics, and normal coronary arteries, as demonstrated by selective coronary cinearteriography. OHD curves in 19 of 20 patients, from zero to full saturation, were nearly identical to those in normal control subjects with values for P50 (Po2 at 50% saturation and pH 7.4) of 26.7±1.5 (mean±SD of the mean) torr (mm Hg) and red blood cell (RBC) levels of 2,3-diphosphoglyceric acid (2, 3-DPG) of 0.72±0.10 (mean±SD of the mean) M/M hemoglobin (Hb). Normal values for nonsmoking adults were: P50, 26.6±1.4 (mean±SD of the mean) torr: and RBC 2,3-DPG, 0.81±0.09 (mean±SD of the mean) M/M Hb. Mean levels of carbon monoxide were normal at 0.14±0.01 (mean±SEM) ml/100 ml WB in 10 patients who were nonsmokers and 0.45±0.15 (mean±SEM) ml/100 ml WB in 10 smokers. In one patient, a heavy smoker with markedly elevated blood carbon monoxide levels, an abnormal leftward shift of the OHD curve was observed. This was corrected after discontinuation of smoking. In utilizing these methods, we could not detect consistent abnormalities of Hb affinity for oxygen at rest in the patients studied, which suggests that a defect in oxygen transport at rest is an unlikely explanation for the symptoms of chest pain in patients with the anginal syndrome and normal coronary arteriograms. Images PMID:4847250

Quantitative RNFL attenuation coefficient measurements by RPE-normalized OCT data

NASA Astrophysics Data System (ADS)

Vermeer, K. A.; van der Schoot, J.; Lemij, H. G.; de Boer, J. F.

2012-03-01

We demonstrate significantly different scattering coefficients of the retinal nerve fiber layer (RNFL) between normal and glaucoma subjects. In clinical care, SD-OCT is routinely used to assess the RNFL thickness for glaucoma management. In this way, the full OCT data set is conveniently reduced to an easy to interpret output, matching results from older (non- OCT) instruments. However, OCT provides more data, such as the signal strength itself, which is due to backscattering in the retinal layers. For quantitative analysis, this signal should be normalized to adjust for local differences in the intensity of the beam that reaches the retina. In this paper, we introduce a model that relates the OCT signal to the attenuation coefficient of the tissue. The average RNFL signal (within an A-line) was then normalized based on the observed RPE signal, resulting in normalized RNFL attenuation coefficient maps. These maps showed local defects matching those found in thickness data. The average (normalized) RNFL attenuation coefficient of a fixed band around the optic nerve head was significantly lower in glaucomatous eyes than in normal eyes (3.0mm-1 vs. 4.9mm-1, P<0.01, Mann-Whitney test).

Human Lung Homotransplantation

PubMed Central

White, J. J.; Tanser, P. H.; Anthonisen, N. R.; Wynands, J. E.; Pare, J. A. P.; Becklake, M. R.; Munro, D. D.; MacLean, L. D.

1966-01-01

Left lung homotransplantation was performed in a 31-year-old man in terminal irreversible respiratory failure due to advanced silicosis. Within 10 minutes of completion of transplantation, arterial pO2 rose from 52 to 211 mm. Hg, pCO2 dropped from 90 to 43 mm. Hg, and pH rose from 7.15 to 7.42. On assisted ventilation, arterial O2 tension was maintained within normal limits for the first four days. Thereafter, arterio-alveolar difference for O2 increased to 300 mm. and that for CO2 to 25 mm. Xenon-133 ventilation perfusion ratios confirmed differences between the two lungs. Terminally, bronchopneumonia and hypoxemia were present. Surfactant content of the lung was within normal limits. Postmortem examination revealed bronchopneumonia, bronchial infarction, lymphatic engorgement and mild rejection. Future efforts should emphasize selection of non-infected donors, minimal reliance on steroids for immunosuppression, cardiopulmonary bypass during transplantation, and more definite criteria for rejection. ImagesFig. 2Fig. 3Fig. 4Fig. 8Fig. 9Fig. 11Fig. 12Fig. 13Fig. 14 PMID:5328358

Digital Pupillometry in Normal Subjects

PubMed Central

Rickmann, Annekatrin; Waizel, Maria; Kazerounian, Sara; Szurman, Peter; Wilhelm, Helmut; Boden, Karl T.

2017-01-01

ABSTRACT The aim of this study was to evaluate the pupil size of normal subjects at different illumination levels with a novel pupillometer. The pupil size of healthy study participants was measured with an infrared-video PupilX pupillometer (MEye Tech GmbH, Alsdorf, Germany) at five different illumination levels (0, 0.5, 4, 32, and 250 lux). Measurements were performed by the same investigator. Ninety images were executed during a measurement period of 3 seconds. The absolute linear camera resolution was approximately 20 pixels per mm. This cross-sectional study analysed 490 eyes of 245 subjects (mean age: 51.9 ± 18.3 years, range: 6–87 years). On average, pupil diameter decreased with increasing light intensities for both eyes, with a mean pupil diameter of 5.39 ± 1.04 mm at 0 lux, 5.20 ± 1.00 mm at 0.5 lux, 4.70 ± 0.97 mm at 4 lux, 3.74 ± 0.78 mm at 32 lux, and 2.84 ± 0.50 mm at 250 lux illumination. Furthermore, it was found that anisocoria increased by 0.03 mm per life decade for all illumination levels (R2 = 0.43). Anisocoria was higher under scotopic and mesopic conditions. This study provides additional information to the current knowledge concerning age- and light-related pupil size and anisocoria as a baseline for future patient studies. PMID:28228832

Evaluation of diaphragmatic motion in normal and diaphragmatic paralyzed dogs using M-mode ultrasonography.

PubMed

Choi, Mihyun; Lee, Namsoon; Kim, Ahyoung; Keh, Seoyeon; Lee, Jinsoo; Kim, Hyunwook; Choi, Mincheol

2014-01-01

Diagnosis of unilateral diaphragmatic paralysis in dogs is currently based on fluoroscopic detection of unequal movement between the crura. Bilateral paralysis may be more difficult to confirm with fluoroscopy because diaphragmatic movement is sometimes produced by compensatory abdominal muscle contractions. The purpose of this study was to develop a new method to evaluate diaphragmatic movement using M-mode ultrasonography and to describe findings for normal and diaphragmatic paralyzed dogs. Fifty-five clinically normal dogs and two dogs with diaphragmatic paralysis were recruited. Thoracic radiographs were acquired for all dogs and fluoroscopy studies were also acquired for clinically affected dogs. Two observers independently measured diaphragmatic direction of motion and amplitude of excursion using M-mode ultrasonography for dogs meeting study inclusion criteria. Eight of the clinically normal dogs were excluded due to abnormal thoracic radiographic findings. For the remaining normal dogs, the lower limit values of diaphragmatic excursion were 2.85-2.98 mm during normal breathing. One dog with bilateral diaphragmatic paralysis showed paradoxical movement of both crura at the end of inspiration. One dog with unilateral diaphragmatic paralysis had diaphragmatic excursion values of 2.00 ± 0.42 mm on the left side and 4.05 ± 1.48 mm on the right side. The difference between left and right diaphragmatic excursion values was 55%. Findings indicated that M-mode ultrasonography is a relatively simple and objective method for measuring diaphragmatic movement in dogs. Future studies are needed in a larger number of dogs with diaphragmatic paralysis to determine the diagnostic sensitivity of this promising new technique. © 2013 American College of Veterinary Radiology.

EFFECTS OF GAMMA IRRADIATION ON EPDM ELASTOMERS (REVISION 1)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clark, E.

Two formulations of EPDM elastomer, one substituting a UV stabilizer for the normal antioxidant in this polymer, and the other the normal formulation, were synthesized and samples of each were exposed to gamma irradiation in initially pure deuterium gas to compare their radiation stability. Stainless steel containers having rupture disks were designed for this task. After 130 MRad dose of cobalt-60 radiation in the SRNL Gamma Irradiation Facility, a significant amount of gas was created by radiolysis; however the composition indicated by mass spectroscopy indicated an unexpected increase in the total amount deuterium in both formulations. The irradiated samples retainedmore » their ductility in a bend test. No change of sample weight, dimensions, or density was observed. No change of the glass transition temperature as measured by dynamic mechanical analysis was observed, and most of the other dynamic mechanical properties remained unchanged. There appeared to be an increase in the storage modulus of the irradiated samples containing the UV stabilizer above the glass transition, which may indicate hardening of the material by radiation damage. Revision 1 adds a comparison with results of a study of tritium exposed EPDM. The amount of gas produced by the gamma irradiation was found to be equivalent to about 280 days exposure to initially pure tritium gas at one atmosphere. The glass transition temperature of the tritium exposed EPDM rose about 10°C. over 280 days, while no glass transition temperature change was observed for gamma irradiated EPDM. This means that gamma irradiation in deuterium cannot be used as a surrogate for tritium exposure.« less

Lactose digestion by human jejunal biopsies: the relationship between hydrolysis and absorption.

PubMed Central

Dawson, D J; Lobley, R W; Burrows, P C; Miller, V; Holmes, R

1986-01-01

The relationship between lactose hydrolysis and absorption of released glucose was investigated by determining the kinetics of lactose digestion by jejunal biopsies incubated in vitro. Lactase activity in intact biopsies correlated with conventional assay of tissue homogenates (r = 0.85, p less than 0.001), and glucose uptake from 28 mM lactose was directly proportional to lactase activity (r = 0.95, p less than 0.001) in 21 subjects with normal lactase levels, six with hypolactasia (primary or secondary to coeliac disease) and two with lactose intolerance but normal lactase activity. Kinetic analysis at 0.56-56 mM lactose in five normal subjects showed saturable kinetics for hydrolysis (app Km = 33.9 +/- 2.2 mM; app Vmax = 26.5 +/- 1.1 nmol/min/mg dry weight) but glucose uptake could be fitted to a model either of saturable uptake (app Kt = 47.2 +/- 0.3 mM; app Jmax = 14.1 +/- 0.2 nmol/min/mg) or saturable uptake plus a linear component (app Kt = 21.3 +/- 1.15; app Jmax = 4.59 +/- 0.12; app Kd = 0.093 +/- 0.010 nmol/min/mg/mM). The proportion of glucose taken into the tissue did not significantly exceed 50% of the total released at any lactose concentration suggesting the lack of an efficient capture mechanism for the released glucose. The results suggest that lactose hydrolysis is the rate limiting step in the overall absorption of glucose from lactose in vitro, and that the relationship between hydrolysis and absorption is the same in normal subjects and in hypolactasic subjects. PMID:3084346

Effect of cilnidipine on normal to marginally elevated urine albumin-creatinine ratio in asymptomatic non-diabetic hypertensive patients: an exponential decay curve analysis.

PubMed

Nakatsu, Takaaki; Toyonaga, Shinji; Mashima, Keiichi; Yuki, Yoko; Nishitani, Aya; Ogawa, Hiroko; Miyoshi, Toru; Hirohata, Satoshi; Izumi, Reishi; Kusachi, Shozo

2010-01-01

High-normal urinary albumin excretion has been reported to have clinical significance with respect to progression of proteinuria and hypertension. We analysed the effect of cilnidipine (10 mg/day) on morning systolic blood pressure (SBP) and urine albumin-creatinine ratio (UACR) in 16 non-diabetic hypertensive patients with a normal to marginally elevated UACR (mean +/- SD 29.4 +/- 21.7; range 7.5-72.9 mg/g creatinine). Sequential home BP and UACR data were fitted to a simple exponential function as follows: where y is SBP (mmHg) or UACR (mg/g creatinine); alpha is the extent of the SBP (mmHg)- or UACR (mg/g creatinine)-lowering effect; beta (days) is the time-constant for SBP or UACR decrease; t is the number of days after the start of cilnidipine administration; and gamma is the finally stabilized SBP (mmHg) or UACR (mg/g creatinine). Mean +/- SD morning SBP and UACR decreased by 20.4 +/- 11.4 mmHg and 15.2 +/- 13.1 mg/g creatinine, respectively, as determined by coefficient alpha. The mean +/- SD time-constant for UACR decrease was significantly longer than that for BP decrease (43.5 +/- 22.9 vs 15.4 +/- 7.1 days). UACR reduction correlated with pre-treatment UACR values (correlation coefficient [R] = 0.88, p < 0.01) but not with BP decrease. The present study demonstrated that cilnidipine reduced UACR in hypertensive patients with normal to marginally elevated UACR independent of its BP-lowering effect.

Evaluation of type II thyroplasty on phonatory physiology in an excised canine larynx model

PubMed Central

Devine, Erin E.; Hoffman, Matthew R.; McCulloch, Timothy M.; Jiang, Jack J.

2016-01-01

Objective Type II thyroplasty is an alternative treatment for spasmodic dysphonia, addressing hyperadduction by incising and lateralizing the thyroid cartilage. We quantified the effect of lateralization width on phonatory physiology using excised canine larynges. Methods Normal closure, hyperadduction, and type II thyroplasty (lateralized up to 5mm at 1mm increments with hyperadducted arytenoids) were simulated in excised larynges (N=7). Aerodynamic, acoustic, and videokymographic data were recorded at three subglottal pressures relative to phonation threshold pressure (PTP). One-way repeated measures ANOVA assessed effect of condition on aerodynamic parameters. Random intercepts linear mixed effects models assessed effects of condition and subglottal pressure on acoustic and videokymographic parameters. Results PTP differed across conditions (p<0.001). Condition affected percent shimmer (p<0.005) but not percent jitter. Both pressure (p<0.03) and condition (p<0.001) affected fundamental frequency. Pressure affected vibratory amplitude (p<0.05) and intra-fold phase difference (p<0.05). Condition affected phase difference between the vocal folds (p<0.001). Conclusions Hyperadduction increased PTP and worsened perturbation compared to normal, with near normal physiology restored with 1mm lateralization. Further lateralization deteriorated voice quality and increased PTP. Acoustic and videokymographic results indicate that normal physiologic relationships between subglottal pressure and vibration are preserved at optimal lateralization width, but then degrade with further lateralization. The 1mm optimal width observed here is due to the small canine larynx size. Future human trials would likely demonstrate a greater optimal width, with patient-specific value potentially determined based on larynx size and symptom severity. PMID:27223665

The relationship between corneal biomechanical properties and confocal microscopy findings in normal and keratoconic eyes.

PubMed

Hurmeric, Volkan; Sahin, Afsun; Ozge, Gokhan; Bayer, Atilla

2010-06-01

To investigate the relationship between corneal biomechanical properties and confocal microscopy (CM) findings in normal and keratoconic eyes. The study consisted of 28 eyes of 28 healthy volunteers and 23 eyes of 15 patients with keratoconus. The diagnosis of keratoconus was made with corneal topography and clinical findings. The corneal hysteresis (CH) and corneal resistance factor (CRF) were measured by the ocular response analyzer. In vivo CM was performed with NIDEK Confoscan 3. CH and CRF were compared with corneal morphological findings (detailed cell counts of endothelial, stromal, and epithelial cells) in vivo. CH was 10.1 +/- 1.3 mm Hg in normal eyes and 7.4 +/- 1.5 mm Hg in keratoconic eyes (P < 0.0001). CRF was 10.1 +/- 1.8 mm Hg in normal eyes and 6.2 +/- 1.4 mm Hg in keratoconic eyes (P < 0.0001). CH and CRF were negatively correlated with full-thickness stromal keratocyte density (P < 0.01; r = -0.52 and P < 0.001; r = -0.67, respectively) in healthy eyes. Keratocyte density of the posterior half of the stroma was found to be significantly related with CRF in healthy eyes (beta = -0.404; P = 0.01). There was no significant relationship among CH, CRF, and CM findings in eyes with keratoconus. There is a significant relationship between CRF and keratocyte density of the posterior half of the stroma in healthy eyes. Our results suggest that corneal elasticity is related to not only stromal matrix but also cellular structure of the cornea.

MR arthrography of the posterior labrocapsular complex: relationship with glenohumeral joint alignment and clinical posterior instability.

PubMed

Tung, Glenn A; Hou, David D

2003-02-01

The purpose of our study was to investigate the relationship between tears of the posterior labrocapsular complex and glenohumeral alignment on MR arthrography and the presence and extent of posterior labrocapsular tears in patients with posterior instability. Posterior labrocapsular tears identified on 24 MR arthrograms and surgically confirmed were evaluated for length of tear and labrocapsular avulsion. These examinations and a comparison cohort of 70 normal MR arthrograms with normal findings were also evaluated for humeral head position relative to the glenoid fossa. Medical records were reviewed for clinical diagnosis of posterior instability and history of shoulder trauma. The position of the humeral head relative to the glenoid was significantly more posterior in patients with posterior labral tear than in patients with a normal posterior labrum (4.9 mm versus 0.7 mm; p < 0.0001). The mean length (+/- SD) of posterior labral tear was 15.9 +/- 1.7 mm, and a direct correlation was found between tear length and posterior humeral translation (r = -0.65; p = 0.002). Posterior labral tears were significantly longer (18.6 vs 13.1 mm; p = 0.04), and posterior humeral translation was greater (6.4 vs 3.4 mm; p = 0.006) in patients with labrocapsular avulsion than in those without avulsion. Twelve (50%) of the patients with posterior labrocapsular tear had posterior instability, and 10 (83%) had a history of macrotrauma. On MR arthrography, the mean posterior humeral translation was greater (6.2 mm +/- 0.08; p = 0.019), posterior labral tears were longer (19.4 mm +/- 1.7; p = 0.0008), and labrocapsular avulsion was more common (83%; p = 0.0001) in patients with posterior instability than in patients who had a posterior labral tear but a clinically stable shoulder. Clinical posterior instability is associated with excessive posterior humeral translation, long posterior labral tears, and posterior labrocapsular avulsion.

Society for Maternal-Fetal Medicine (SMFM) Consult Series #45: Mild fetal ventriculomegaly: Diagnosis, evaluation, and management.

PubMed

Fox, Nathan S; Monteagudo, Ana; Kuller, Jeffrey A; Craigo, Sabrina; Norton, Mary E

2018-04-26

Ventriculomegaly is defined as dilation of the fetal cerebral ventricles and is a relatively common finding on prenatal ultrasound. The purpose of this document is to review the diagnosis, evaluation, and management of mild fetal ventriculomegaly. When enlargement of the lateral ventricles (≥10 mm) is identified, a thorough evaluation should be performed, including detailed sonographic evaluation of fetal anatomy, amniocentesis for karyotype and chromosomal microarray analysis (CMA), and a workup for fetal infection. In some cases, fetal magnetic resonance imaging (MRI) may identify other central nervous system abnormalities and should be considered when this technology as well as expert interpretation is available. Follow-up ultrasound examination should be performed to assess for progression of the ventricular dilation. In the setting of isolated ventriculomegaly of 10 to 12 mm, the likelihood of survival with normal neurodevelopment is greater than 90%. With moderate ventriculomegaly (13-15 mm), the likelihood of normal neurodevelopment is 75-93%. The following are Society for Maternal-Fetal Medicine recommendations: we suggest that ventriculomegaly be characterized as mild (10-12 mm), moderate (13-15 mm), or severe (>15 mm) for the purposes of patient counseling, given that the chance of an adverse outcome and potential for other abnormalities are higher when the ventricles measure 13-15 mm versus 10-12 mm (GRADE 2B); we recommend that diagnostic testing (amniocentesis) with CMA should be offered, when ventriculomegaly is detected (GRADE 1B); we recommend testing for CMV and toxoplasmosis when ventriculomegaly is detected, regardless of known exposure or symptoms (GRADE 1B); we suggest that MRI be considered in cases of mild or moderate fetal ventriculomegaly when this modality and expert radiologic interpretation are available; an MRI is likely to be of less value if the patient has had a detailed ultrasound performed by an individual with specific experience and expertise in sonographic imaging of the fetal brain (GRADE 2B); we recommend that timing and mode of delivery be based on standard obstetric indications (GRADE 1C); we recommend that with isolated mild ventriculomegaly of 10 mm to 12 mm, after a complete evaluation, women be counseled that the outcome is favorable, and the infant is likely to be normal (GRADE 1B); we recommend that with isolated moderate ventriculomegaly of 13 mm to 15 mm, after a complete evaluation, women be counseled that the outcome is likely to be favorable but that there is an increased risk of neurodevelopmental disabilities (GRADE 1B). Copyright © 2018. Published by Elsevier Inc.

Ophthalmic diagnostic tests in captive red-footed tortoises (Chelonoidis carbonaria) in Salvador, northeast Brazil.

PubMed

Oriá, Arianne P; Silva, Renata M Monção; Pinna, Melissa H; Oliveira, Alberto Vinícius D; Ferreira, Paulo Roberto B; Martins Filho, Emanoel F; Meneses, Iris Daniela S; Requião, Kátia G; Ofri, Ron

2015-01-01

The aim of this study was to establish normal ophthalmic parameters for select diagnostic tests in red-footed tortoises (Chelonoides carbonaria). A total of 52 animals, approximately 20-30 years old, were studied. Ophthalmic diagnostic tests included culturing of the normal conjunctival bacterial flora in summer and winter, evaluation of tear production using Schirmer tear test (STT) and endodontic absorbent paper point tear test in two different environmental temperatures (EAPPTT-1 at 32 °C and EAPPTT-2 at 18 °C), cytology of conjunctival cells, B-mode ultrasonography, measurement of palpebral fissure length (PFL), and applanation tonometry (in two different positions). In both seasons, Gram-positive bacteria were predominant. Median (± IQR/2) STT was 12.0 ± 3.5 mm/min, EAPPTT-1 was 15.9 ± 0.7 mm/15 s, and EAPPTT-2 was 15.4 ± 0.4 mm/min (OD) and 17.8 ± 1.0 mm/min (OS). Anterior chamber depth was 1.0 ± 0.1 mm, lens axial length was 2.3 ± 0.1 mm, vitreous chamber depth was 4.3 ± 0.2 mm, and axial globe length was 7.7 ± 0.3 mm. PFL was 11.7 ± 1.7 mm. Intraocular pressure was 11.5 ± 2.8 mmHg for males and 14.0 ± 3.5 mmHg for females (dorsoventral position) and 18.0 ± 3.2 mmHg for males and 24.1 ± 3.0 mmHg for females (ventrodorsal position with inclination of 45°). The ophthalmic parameters reported here can aid in the diagnosis of eye diseases in red-footed tortoises (Chelonoides carbonaria). © 2014 American College of Veterinary Ophthalmologists.

The predictive value of retinal vascular findings for carotid artery atherosclerosis: are further recommendations with regard to carotid atherosclerosis screening needed?

PubMed

Song, Yeo-Jeong; Cho, Kyoung-Im; Kim, Seong-Man; Jang, Hyun-Duk; Park, Jung-Min; Kim, Sang-Soo; Kim, Dong-Jun; Lee, Hyeon-Gook; Kim, Tae-Ik

2013-05-01

Vascular retinopathy is the consequence of vascular disease, and the retina is the only place where the arteries can be visualized directly. The purpose of this study was to evaluate the predictive value of retinal vascular findings for carotid artery atherosclerosis. From December 2009 to January 2011, the carotid intima-media thickness (IMT) and total plaque area (TPA) were measured in 179 consecutive patients, who received a fundoscopic examination. The patients were divided into groups as follows: normal retinal artery (normal; n = 44), diabetic retinopathy (DR; n = 25), retinal artery occlusion (RAO; n = 17), retinal vein occlusion (RVO; n = 67), and hypertensive retinopathy (HTN-R; n = 26). The subjects were classified according to the presence of an increased (≥ 1 mm) IMT and plaque. The values of the mean carotid IMT in the patients with vascular retinopathy (DR, 0.87 ± 0.14 mm; RAO, 1.18 ± 0.47 mm; RVO, 0.84 ± 0.14 mm; HTN-R, 0.90 ± 0.20 mm) were significantly increased compared with those in the normal subjects (0.77 ± 0.13 mm). A total 77 of 135 vascular retinopathy patients demonstrated an increased IMT (57 %), and 97 vascular retinopathy patients had carotid artery plaque (72 %). The relative risk of vascular retinopathy in the prediction of an increased IMT and the presence of plaque was 2.79 and 3.95, respectively. Although The TPA was significantly increased in the patients with RAO (1.87 ± 2.67 cm(2)) and RVO (0.27 ± 0.23 cm(2)) compared with the normal subjects (0.18 ± 0.23 cm(2), all Ps < 0.05), there was no significant difference in the ipsilateral carotid IMT and TPA of the affected eye compared with that of the contralateral eye. In conclusion, vascular retinopathy demonstrated a good predictive value in identifying asymptomatic carotid artery atherosclerosis, and this was not confined to the ipsilateral carotid artery of the affected eye. Further recommendations with regard to carotid atherosclerosis screening in patients with vascular retinopathy should be considered.

In vivo detection of clinically non-apparent ocular surface inflammation in patients with meibomian gland dysfunction-associated refractory dry eye symptoms: a pilot study

PubMed Central

Qazi, Y; Kheirkhah, A; Blackie, C; Cruzat, A; Trinidad, M; Williams, C; Korb, D R; Hamrah, P

2015-01-01

Purpose The utility of in vivo confocal microscopy (IVCM) in the investigation of palpebral conjunctival and corneal inflammation in patients with meibomian gland dysfunction (MGD)-associated refractory dry eye symptoms following gland expression, despite objective clinical improvement. Methods A retrospective, observational pilot study was conducted evaluating five patients with MGD-associated refractory dry eye symptoms and three control groups: symptomatic untreated MGD patients (n=3), treatment-responsive MGD patients with improved symptoms (n=3) and asymptomatic healthy normals (n=11). Ocular surface disease index (OSDI) scores, tear break-up time (TBUT), the number of meibomian glands yielding liquid secretion (MGYLS), palpebral conjunctival epithelial and substantia propria immune cell (EIC, SIC), and corneal dendritic cell (DC) densities were measured. Results Despite clinical improvement (TBUT: 6.4±1.2 s to 10.1±2.1 s, P=0.03; MGYLS: 3.5±0.8 glands to 7.0±1.1 glands, P=0.13) and a normal clinical examination post treatment, MGD patients remained symptomatic. IVCM revealed increased immune cells in the palpebral conjunctiva (refractory MGD EIC=592.6±110.1 cells/mm2; untreated MGD EIC=522.6±104.7 cells/mm2, P=0.69; responsive MGD EIC=194.9±119.4 cells/mm2, P<0.01; normals EIC=123.7±19.2 cells/mm2, P< 0.001), but not the cornea (refractory MGD DC=60.9±28.3 cells/mm2; normals DC=25.9±6.3 cells/mm2; P=0.43). EIC did not correlate with TBUT (Rs=−0.26, P=0.33). OSDI scores correlated with both EIC (Rs=0.76, P<0.001) and TBUT (Rs=−0.69, P<0.01) but not SIC. Intraglandular immune cells were also seen. Conclusion MGD-associated refractory symptoms and the symptom-sign disparity may be explained by clinically non-apparent, active inflammation of the palpebral conjunctiva as detected by IVCM. These patients may benefit from anti-inflammatory therapy. PMID:26088680

The biomechanical effect of artificial and human bone density on stopping and stripping torque during screw insertion.

PubMed

Tsuji, Matthew; Crookshank, Meghan; Olsen, Michael; Schemitsch, Emil H; Zdero, Rad

2013-06-01

Orthopedic surgeons apply torque to metal screws manually by "subjective feel" to obtain adequate fracture fixation, i.e. stopping torque, and attempt to avoid accidental over-tightening that leads to screw-bone interface failure, i.e. stripping torque. Few studies have quantified stripping torque in human bone, and only one older study from 1980 reported stopping/ stripping torque ratio. The present aim was to measure stopping and stripping torque of cortical and cancellous screws in artificial and human bone over a wide range of densities. Sawbone blocks were obtained having densities from 0.08 to 0.80g/cm(3). Sixteen fresh-frozen human femurs of known standardized bone mineral density (sBMD) were also used. Using a torque screwdriver, 3.5-mm diameter cortical screws and 6.5-mm diameter cancellous screws were inserted for adequate tightening as determined subjectively by an orthopedic surgeon, i.e. stopping torque, and then further tightened until failure of the screw-bone interface, i.e. stripping torque. There were weak (R=0.25) to strong (R=0.99) linear correlations of absolute and normalized torque vs. density or sBMD. Maximum stopping torques normalized by screw thread area engaged by the host material were 15.2N/mm (cortical screws) and 13.4N/mm (cancellous screws) in sawbone blocks and 20.9N/mm (cortical screws) and 6.1N/mm (cancellous screws) in human femurs. Maximum stripping torques normalized by screw thread area engaged by the host material were 23.4N/mm (cortical screws) and 16.8N/mm (cancellous screws) in sawbone blocks and 29.3N/mm (cortical screws) and 8.3N/mm (cancellous screws) in human femurs. Combined average stopping/ stripping torque ratios were 80.8% (cortical screws) and 76.8% (cancellous screws) in sawbone blocks, as well as 66.6% (cortical screws) and 84.5% (cancellous screws) in human femurs. Surgeons should be aware of stripping torque limits for human femurs and monitor stopping torque during surgery. This is the first study of the effect of sawbone density or human bone sBMD on stopping and stripping torque. Copyright © 2013 Elsevier Ltd. All rights reserved.

Fasting does not induce gastric emptying in rats.

PubMed

Brito, Marcus Vinicius Henriques; Yasojima, Edson Yuzur; Teixeira, Renan Kleber Costa; Houat, Abdallah de Paula; Yamaki, Vitor Nagai; Costa, Felipe Lobato da Silva

2015-03-01

To evaluate the effect of fasting on gastric emptying in mice. Twenty-eight mice were distributed into three study groups: a normal group (N=4): normal standard animals; a total fasting group (N=12): subjected to food and water deprivation and a partial fasting group (N=12): subjected to food deprivation only. The fasting groups were subdivided into three subgroups of four animals each, according to the date of euthanasia: 24, 48 and 72 hours. Was analyzed: the gastric volume, degree of the gastric wall distention and the presence of food debris in gastrointestinal tract. The mean gastric volume was 1601 mm3 in the normal group, 847 mm3 in total fasting group and 997 mm3 in partial fasting group. There was difference between the fasting groups in any analyzed period (p<0.05). Regarding the presence of food debris in the gastrointestinal tract and the degree of distension of the stomach, there was no difference between the groups that underwent total or partial fasting (p>0.05). Total fasting or only-solids deprivation does not induce gastric emptying in mice.

X-ray radiation detectors of ``scintillator-photoreceiving device type'' for industrial digital radiography with improved spatial resolution

NASA Astrophysics Data System (ADS)

Ryzhykov, V. D.; Lysetska, O. K.; Opolonin, O. D.; Kozin, D. N.

2003-06-01

Main types of photoreceivers used in X-ray digital radiography systems are luminescent screens that transfer the optical image onto charge collection instruments, which require cooling, and semiconductor silicon detectors, which limit the contrast sensitivity. We have developed and produced X-ray radiation detectors of "scintillator-photoreceiving device" (S-PRD) type, which are integrally located on the inverse side of the photodiode (PD). The receiving-converting circuit (RCC) is designed for data conversion into digital form and their input into PC. Software is provided for RCC control and image visualization. Main advantages of these detectors are high industrial resolution (3-5 line pairs per mm), detecting activity up to 20 μm, controlled sensitivity, low weight and small size, imaging low (0.1-0.3 mrad) object dose in real time. In this work, main characteristics of 32-, 64- and 1024-channel detectors of S-PRD type were studied and compared for X-ray sensitivity with S-PD detectors. Images of the tested objects have been obtained. Recommendations are given on the use of different scintillation materials, depending upon the purpose of a digital radiographic system. The detectors operate in a broad energy range of ionizing radiation, hence the size of the controlled object is not limited. The system is sufficiently powerful to ensure frontal (through two walls) observation of pipelines with wall thickness up to 10 cm.

A possible upgrade of FLASH for harmonic lasing down to 1.3 nm

NASA Astrophysics Data System (ADS)

Schneidmiller, E. A.; Yurkov, M. V.

2013-07-01

We propose the 3rd harmonic lasing in a new FLASH undulator as a way to produce intense, narrow-band, and stable SASE radiation down to 1.3 nm with the present accelerator energy of 1.25 GeV. To provide optimal conditions for harmonic lasing, we suggest to suppress the fundamental with the help of a special set of phase shifters. We rely on the standard technology of gap-tunable planar hybrid undulators, and choose the period of 2.3 cm and the minimum gap of 0.9 cm; total length of the undulator system is 34.5 m. With the help of numerical simulations we demonstrate that the 3rd harmonic lasing at 1.3 nm provides peak power at a gigawatt level and the narrow intrinsic bandwidth, 0.1% (FWHM). Pulse duration can be controlled in the range of a few tens of femtoseconds, and the peak brilliance reaches the value of 1031 photons/(s mrad2 mm2 0.1% BW). With the given undulator design, a standard option of lasing at the fundamental wavelength to saturation is possible through the entire water window and at longer wavelengths. In this paper we briefly consider additional options such as polarization control, bandwidth reduction, self-seeding, X-ray pulse compression, and two-color operation. We also discuss possible technical issues and backup solutions.

A high-energy, high-flux source of gamma-rays from all-optical non-linear Thomson scattering

NASA Astrophysics Data System (ADS)

Corvan, D. J.; Zepf, M.; Sarri, G.

2016-09-01

γ-Ray sources are among the most fundamental experimental tools currently available to modern physics. As well as the obvious benefits to fundamental research, an ultra-bright source of γ-rays could form the foundation of scanning of shipping containers for special nuclear materials and provide the bases for new types of cancer therapy. However, for these applications to prove viable, γ-ray sources must become compact and relatively cheap to manufacture. In recent years, advances in laser technology have formed the cornerstone of optical sources of high energy electrons which already have been used to generate synchrotron radiation on a compact scale. Exploiting the scattering induced by a second laser, one can further enhance the energy and number of photons produced provided the problems of synchronisation and compact γ-ray detection are solved. Here, we report on the work that has been done in developing an all-optical and hence, compact non-linear Thomson scattering source, including the new methods of synchronisation and compact γ-ray detection. We present evidence of the generation of multi-MeV (maximum 16-18 MeV) and ultra-high brilliance (exceeding 1020 photons s-1mm-2mrad-2 0.1% BW at 15 MeV) γ-ray beams. These characteristics are appealing for the paramount practical applications mentioned above.

Instantaneous electron beam emittance measurement system based on the optical transition radiation principle

NASA Astrophysics Data System (ADS)

Jiang, Xiao-Guo; Wang, Yuan; Zhang, Kai-Zhi; Yang, Guo-Jun; Shi, Jin-Shui; Deng, Jian-Jun; Li, Jin

2014-01-01

One kind of instantaneous electron beam emittance measurement system based on the optical transition radiation principle and double imaging optical method has been set up. It is mainly adopted in the test for the intense electron-beam produced by a linear induction accelerator. The system features two characteristics. The first one concerns the system synchronization signal triggered by the following edge of the main output waveform from a Blumlein switch. The synchronous precision of about 1 ns between the electron beam and the image capture time can be reached in this way so that the electron beam emittance at the desired time point can be obtained. The other advantage of the system is the ability to obtain the beam spot and beam divergence in one measurement so that the calculated result is the true beam emittance at that time, which can explain the electron beam condition. It provides to be a powerful beam diagnostic method for a 2.5 kA, 18.5 MeV, 90 ns (FWHM) electron beam pulse produced by Dragon I. The ability of the instantaneous measurement is about 3 ns and it can measure the beam emittance at any time point during one beam pulse. A series of beam emittances have been obtained for Dragon I. The typical beam spot is 9.0 mm (FWHM) in diameter and the corresponding beam divergence is about 10.5 mrad.

Behavioral Effects of Acute Aerosol Exposure to N, N-Diethy-Meta-toluamide (M-Det), January - February 1979

DTIC Science & Technology

1979-02-01

MRAD 8SIThIJC11OM REPORT DOCUMENTATION PAGE BEXPORE COUP1LzTDE Fe6w 109FORTNUMBIA5. GOVY &CC91146OW NO0 1. * CSIFNT S CAT ALOG MNSummE 4. TIVL flo) TYP...introducing variables due to leftover pheromones and other odors. The sensor counted vibrations (e.j., tremors), nonambulatory movements (e.g., grooming

Fallout strontium-90 and cesium-137 in northern Alaskan ecosystems during 1959--1970

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hanson, Wayne C.

1973-05-01

Cycling routes, rates of transport, and resultant concentrations of the fallout radionuclides 90Sr and 137Cs in northern Alaskan ecosystems were defined during the period 1959 to 1970. Radiochemical analysis of extensive samples of biota and whole-body counting of 137Cs in Eskimo and Indian ethnic groups were related to ecological principles, especially the concept of trophic niche, which elucidated the observed patterns of radionuclide concentrations. Experiments involving Sr and Cs radioisotopes applied to natural Cladonia-- Cetraria lichen carpets yielded effective half-times of 1.O to 1.6 years for Sr and more than 10 years for Cs. Direct and indirect estimates of 131Csmore » half-times in Eskimos on a caribou meat diet were made by dietary manipulation and by relating dietary 137Cs intake and resultant change between periodic whole body counts. Effective half- times of 70 days for adults (more than 21 years old) and minors (14 to 20 years old) and of 45 days for children (less than 14 years old) were found. Suitable mathematical models were used to compute lichen forage ingestion rates of free- ranging adult caribou (4.5 to 5.0 kg dry weight per day), caribou meat ingestion rates of Anaktuvuk Pass residents (up to 2 kg wet weight per day for men), and 90Sr body burdens of Anaktuvuk Pass residents during the period 1952 to 1968 (maximum value of 8 nCi in adult males during late 1966 to early 1967). Special emphasis was made of cultural influences upon the food-gathering patterns of the native peoples studied. Culture change, especially in the form of food stamps, welfare payments, acquisition of snowmobiles, and improved housing was documented throughout the study and noticeably reduced the radionuclide accumulations. Total radiation dose rates to the Anaktuvuk Pass adult population were estimated to be about 100 mrad/year from natural sources, 60 to 140 mrad/year from 137Cs body burdens, and 20 to 130 mrad/year from 90Sr body burdens.« less

Biomechanics of the Human Posterior Sclera: Age- and Glaucoma-Related Changes Measured Using Inflation Testing

PubMed Central

Coudrillier, Baptiste; Tian, Jing; Alexander, Stephen; Myers, Kristin M.; Quigley, Harry A.; Nguyen, Thao D.

2012-01-01

Purpose. The objective of this study was to measure the biomechanical response of the human posterior sclera in vitro and to estimate the effects of age and glaucoma. Methods. Scleral specimens from 22 donors with no history of glaucoma and 11 donors with a history of glaucoma were excised 3 mm posterior to the equator and affixed to an inflation chamber. Optic nerve cross-sections were graded to determine the presence of axon loss. The time-dependent inflation response was measured in a series of pressure-controlled load–unload tests to 30 mm Hg and creep tests to 15 and 30 mm Hg. Circumferential and meridional strains were computed from the digital image correlation displacements, and midposterior stresses were determined from pressure and deformed geometry. Results. Among normal specimens, older age was predictive of a stiffer response and a thinner sclera. In the age group 75 to 93, diagnosed glaucoma eyes with axon damage were thicker than normal eyes. Both damaged and undamaged glaucoma eyes had a different strain response in the peripapillary sclera characterized by a stiffer meridional response. Undamaged glaucoma eyes had slower circumferential creep rates in the peripapillary sclera than normal eyes. Glaucoma eyes were not different from normal eyes in stresses and strains in the midposterior sclera. Conclusions. The observed differences in the biomechanical response of normal and glaucoma sclera may represent baseline properties that contribute to axon damage, or may be characteristics that result from glaucomatous disease. PMID:22395883

The Effect of Patellar Thickness on Intraoperative Knee Flexion and Patellar Tracking in Patients With Arthrofibrosis Undergoing Total Knee Arthroplasty.

PubMed

Kim, Abraham D; Shah, Vivek M; Scott, Richard D

2016-05-01

We evaluated the intraoperative effect of patellar thickness on intraoperative passive knee flexion and patellar tracking during total knee arthroplasty (TKA) in patients with preoperative arthrofibrosis and compared them to patients with normal preoperative range of motion (ROM) documented in a prior study. Routine posterior cruciate ligament-retaining TKA was performed in a total of 34 knees, 23 with normal ROM and 11 with arthrofibrosis, defined as ≤100° of passive knee flexion against gravity under anesthesia. Once clinical balance and congruent patellar tracking were established, custom trial patellar components thicker than the standard trial by 2-mm increments (2-8 mm) were sequentially placed and trialed. Passive flexion against gravity was recorded using digital photograph goniometry. Gross mechanics of patellofemoral tracking were visually assessed. On average, passive knee flexion decreased 2° for every 2-mm increment of patellar thickness (P < .0001), which was similar to patients with normal preoperative ROM. In addition, increased patellar thickness had no gross effect on patellar subluxation and tilt in patients with arthrofibrosis as well as those with normal ROM. Patellar thickness had a modest effect on intraoperative passive flexion and no effect on patellar tracking in patients with arthrofibrosis undergoing TKA. There was no marked difference in intraoperative flexion and patellar tracking between patients with arthrofibrosis and patients with normal preoperative ROM. Copyright © 2016 Elsevier Inc. All rights reserved.

Normal-phase liquid chromatography retention behavior of polycyclic aromatic sulfur heterocycles and alkyl-substituted polycyclic aromatic sulfur heterocycle isomers on an aminopropyl stationary phase.

PubMed

Wilson, Walter B; Hayes, Hugh V; Sander, Lane C; Campiglia, Andres D; Wise, Stephen A

2018-02-01

Retention indices for 67 polycyclic aromatic sulfur heterocycles (PASHs) and 80 alkyl-substituted PASHs were determined using normal-phase liquid chromatography (NPLC) on an aminopropyl (NH 2 ) stationary phase. The retention behavior of PASH on the NH 2 phase is correlated with the number of aromatic carbon atoms and two structural characteristics have a significant influence on their retention: non-planarity (thickness, T) and the position of the sulfur atom in the bay-region of the structure. Correlations between solute retention on the NH 2 phase and T of PASHs were investigated for three cata-condensed (cata-) PASH isomer groups: (a) 13 four-ring molecular mass (MM) 234 Da cata-PASHs, (b) 20 five-ring MM 284 Da cata-PASHs, and (c) 12 six-ring MM 334 Da cata-PASHs. Correlation coefficients ranged from r = -0.49 (MM 234 Da) to r = -0.65 (MM 334 Da), which were significantly lower than structurally similar PAH isomer groups (r = -0.70 to r = -0.99). The NPLC retention behavior of the PASHs are compared to similar results for PAHs.

Early pregnancy assessment with transvaginal ultrasound scanning.

PubMed Central

Daya, S; Woods, S; Ward, S; Lappalainen, R; Caco, C

1991-01-01

OBJECTIVE: To establish normal parameters in early pregnancy through transvaginal ultrasonography so that gestational age can be determined and to correlate the sonographic findings with serum human chorionic gonadotropin (hCG) levels calibrated against the first international reference preparation standard. SETTING: Infertility clinic. PATIENTS: Thirty-five women with normal intrauterine pregnancy. INTERVENTIONS: Serial measurement of the serum hCG level and the diameter of the gestational sac through transvaginal ultrasonography. MAIN RESULTS: The gestational sac could not be visualized when the hCG level was less than 1100 IU/L. The average growth rate of the sac was 0.9 mm/d. The threshold values for sac diameter, serum hCG level and gestational age below which the yolk sac was not visible were 3.7 mm, 1900 IU/L and 36 days respectively; the corresponding values above which the yolk sac was always visible were 6.7 mm, 5800 IU/L and 40 days. The threshold values below which cardiac activity was not visible were 8.3 mm, 9200 IU/L and 41 days respectively, and the corresponding values above which cardiac activity was always visible were 14.0 mm, 24,000 IU/L and 46 days. The mean gestational ages and the 95% confidence and prediction intervals were tabulated so that measurement of the gestational sac diameter could be used to estimate gestational age early in normal pregnancy. CONCLUSIONS: Transvaginal ultrasonography enables detection of an intrauterine sac and reliable estimation of gestational age on the basis of sac dimensions before an embryo can be seen. PMID:1993291

MicroRNA-9 suppresses the growth, migration, and invasion of malignant melanoma cells via targeting NRP1.

PubMed

Xu, Dan; Chen, Xiaofeng; He, Quanyong; Luo, Chengqun

2016-01-01

MicroRNAs (miRs) are a class of small noncoding RNAs that negatively regulate the gene expression by directly binding to the 3' untranslated region of their target mRNA, thus resulting in mRNA degradation or translational repression. miR-9 has recently been demonstrated to play a role in the development and progression of malignant melanoma (MM), but the regulatory mechanism of miR-9 in the malignant phenotypes of MM still remains largely unknown. In this study, a total of 73 pairs of MM tissues and adjacent normal tissues were collected. Real-time reverse transcription polymerase chain reaction and Western blot were used to detect the mRNA and protein expression of miR-9. MTT assay, wound healing assay, and transwell assay were conducted to determine the cell proliferation, migration, and invasion. Luciferase reporter assay was used to determine the targeting relationship between miR-9 and NRP1. Our data demonstrated that miR-9 expression was significantly downregulated in MM tissues compared with that in adjacent normal tissues. The decreased miR-9 level was significantly associated with the tumor stage and metastasis of MM. We also found that the expression level of miR-9 was decreased in MM cell lines (G361, B16, A375, and HME1) compared with normal skin HACAT cells. Ectopic expression of miR-9 led to a significant decrease in the ability of proliferation, migration, and invasion in A375 cells. NRP1 was further identified as a direct target gene of miR-9, and the protein expression of NRP1 was negatively regulated by miR-9 in A375 cells. Furthermore, overexpression of NRP1 reversed the suppressive effects of miR-9 on the malignant phenotypes of A375 cells. In vivo study revealed that miR-9 overexpression decreased the tumor growth, while overexpression of NRP1 increased MM growth. In summary, our findings suggest that the miR-9/NRP1 axis may serve as a potential target for the treatment of MM.

Investigation of Infant Brain with or without Hydrocephalous in Our Environment Using Anterior Transfontanelle Ultrasound Scan.

PubMed

Marchie, Tobechukwu T; Ayara, Charles O

2013-01-01

A prospective study aimed to suggest easy and simple reproducible ventricular site that will be basic measurement plane and normal dimension determined, correlated to sizes of infants for comparative evaluation of hydrocephalous infants and should be reproducible in follow-up. A prospective study done in University of Benin Teaching Hospital Benin, Nigeria. This study used 50 consecutive infants with Ultrasound scan (US) diagnosis of hydrocephalus and a control group of 50 US normal from 1(st) January 2007 to 30(th) June 2008. The infants were scan through the mid-patent anterior fontanelle in sagittal, and transverse planes with minor angulations to properly outline the ventricles and the position of measurement determined at the foramen of Monro of lateral ventricles and the diameter measured. The infants' weight, crown-heel length, and head circumference were measured and body mass index (BMI) calculated and correlated to lateral ventricular measurement. Data analysis was conducted using the Statistical Package for Social Sciences (SPSS Inc, USA), Version 11.0. There was no statistically sex and age-related difference. There is statistically comparative high mean weight and height and lower BMI in hydrocephalic infants as against the control group (P < 0.001). The mean head circumference for hydrocephalus was 45.6 (± 10.5 standard deviation [SD]), whereas the control group was 35.9 (± 2.7 SD) with P < 0.001. The mean diameter of the anterior horn of left and right lateral ventricles at the level of foramen of Monro in hydrocephalic subjects is 18.4 mm ± 14.3 mm and 20.1 mm ± 16.8 mm with median diameter of 14.1 mm and 15.2 mm, respectively, whereas control group is 2.5 mm ± 0.6 mm and 2.5 mm ± 0.7 mm with median diameter of 2.5 mm and 2.4 mm, respectively. Transfontanelle US was found highly useful in investigation of hydrocephalous in infant.

MR diffusion tensor imaging of normal kidneys.

PubMed

Wang, Wen-juan; Pui, Margaret H; Guo, Yan; Hu, Xiao-shu; Wang, Huan-jun; Yang, Dong

2014-11-01

To assess the feasibility of diffusion tensor imaging (DTI) of normal kidneys and the influence of hydration state. Ten healthy volunteers underwent renal DTI after fasting for 12 hours and 4 hours, without fasting, and following water diuresis. Medullary and cortical apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values were measured and compared in the four different states of hydration. DTI was performed with a 3T magnetic resonance imaging (MRI) system using fat-saturated single-shot spin-echo echo planar imaging sequence. ADC of normal cortex (2.387 ± 0.081 × 10(-3) mm(2) /s) was significantly higher (t = 20.126, P = 0) than that of medulla (1.990 ± 0.063 × 10(-3) mm(2) /s). The FA value of normal cortex (0.282 ± 0.017) was significantly lower (t = -42.713, P = 0) than that of medulla (0.447 ± 0.022). The ADC and FA values of the left renal cortex (2.404 ± 0.082 × 10(-3) mm(2) /s, 0.282 ± 0.017) and medulla (2.002 ± 0.081 × 10(-3) mm(2) /s, 0.452 ± 0.024) were not significantly different (P > 0.05) from those of right renal cortex (2.369 ± 0.080 × 10(-3) mm(2) /s, 0.283 ± 0.018) and medulla (1.978 ± 0.039 × 10(-3) mm(2) /s, 0.443 ± 0.019). Values for ADC (×10(-3) mm(2) /s) and FA in the 12-hour fasting, 4-hour fasting, nonfasting, and water diuresis states were 2.372 ± 0.095 and 0.278 ± 0.018, 2.387 ± 0.081 and 0.282 ± 0.017, 2.416 ± 0.051 and 0.279 ± 0.023, 2.421 ± 0.068, and 0.270 ± 0.021, respectively, in cortex, 1.972 ± 0.084 and 0.438 ± 0.014, 1.990 ± 0.063 and 0.447 ± 0.022, 2.021 ± 0.081 and 0.450 ± 0.031, 2.016 ± 0.076 and 0.449 ± 0.028, respectively, in medulla. The ADC and FA values in different hydration states were not significantly different (P > 0.05). DTI of normal kidneys is feasible with reproducible ADC and FA values independent of hydration states. © 2013 Wiley Periodicals, Inc.

Experimental Design and Analysis of M1A1 Commander/Gunner Performance during CONOPS (Continuous Operations) Using the U-COFT (Unit Conduct of Fire Trainer)

DTIC Science & Technology

1989-09-01

gun b. 7.62-mm coax manchine gun c. Commander’s weapon station caliber .50 machine gun d. M250 grenade launchers 2. Ammunition Simulation a. 105-mm...7.62-mm machine gun f. M250 smoke grenades 3. Normal Mode Simulation a. Stabilized coax machine gun b. Stabilized main gun c. Commander’s weapon d

The effects of apolipoprotein ε 4 on aging brain in cognitively normal Chinese elderly: a surface-based morphometry study.

PubMed

Lu, Hanna; Ma, Suk Ling; Chan, Sandra Sau Man; Lam, Linda Chiu Wa

2016-09-01

Default mode network (DMN) has been reported to be susceptible to APOE ε 4 genotype. However, the APOE ε 4-related brain changes in young carriers are different from the ones in elderly carriers. The current study aimed to evaluate the cortical morphometry of DMN subregions in cognitively normal elderly with APOE ε 4. 11 cognitively normal senior APOE ε 4 carriers and 27 matched healthy controls (HC) participated the neuropsychological tests, genotyping, and magnetic resonance imaging (MRI) scanning. Voxel-based morphometry (VBM) analysis was used to assess the global volumetric changes. Surface-based morphometry (SBM) analysis was performed to measure regional gray matter volume (GMV) and gray matter thickness (GMT). Advancing age was associated with decreased GMV of DMN subregions. Compared to HC, APOE ε 4 carriers presented cortical atrophy in right cingulate gyrus (R_CG) (GMV: APOE carriers: 8475.23 ± 1940.73 mm3, HC: 9727.34 ± 1311.57 mm3, t = 2.314, p = 0.026, corrected) and left insular (GMT: APOE ε 4 carriers: 3.83 ± 0.37 mm, HC: 4.05 ± 0.25 mm, t = 2.197, p = 0.033, corrected). Our results highlight the difference between different cortical measures and suggest that the cortical reduction of CG and insular maybe a potential neuroimaging marker for APOE 4 ε senior carriers, even in the context of relatively intact cognition.

Omega-3 fatty acids, EPA and DHA induce apoptosis and enhance drug sensitivity in multiple myeloma cells but not in normal peripheral mononuclear cells.

PubMed

Abdi, J; Garssen, J; Faber, J; Redegeld, F A

2014-12-01

The n-3 polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been shown to enhance the effect of chemotherapeutic drugs in clinical studies in cancer patients and to induce apoptotic tumor cell death in vitro. Until now, EPA and DHA have never been investigated in multiple myeloma (MM). Human myeloma cells (L363, OPM-1, OPM-2 and U266) and normal peripheral blood mononuclear cells were exposed to EPA and DHA, and effects on mitochondrial function and apoptosis, caspase-3 activation, gene expression and drug toxicity were measured. Exposure to EPA and DHA induced apoptosis and increased sensitivity to bortezomib in MM cells. Importantly, they did not affect viability of normal human peripheral mononuclear cells. Messenger RNA expression arrays showed that EPA and DHA modulated genes involved in multiple signaling pathways including nuclear factor (NF) κB, Notch, Hedgehog, oxidative stress and Wnt. EPA and DHA inhibited NFκB activity and induced apoptosis through mitochondrial perturbation and caspase-3 activation. Our study suggests that EPA and DHA induce selective cytotoxic effects in MM and increase sensitivity to bortezomib and calls for further exploration into a potential application of these n-3 polyunsaturated fatty acids in the therapy of MM. Copyright © 2014 Elsevier Inc. All rights reserved.

SU-E-T-331: Dosimetric Impact of Multileaf Collimator Leaf Width On Stereotactic Radiosurgery (SRS) RapidArc Treatment Plans for Single and Multiple Brain Metastases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hossain, S; Keeling, V; Ahmad, S

Purpose: To determine the effects of multileaf collimator (MLC) leaf width on normal-brain-tissue doses and dose conformity of SRS RapidArc treatment plans for brain tumors. Methods: Ten patients with 24 intracranial tumors (seven with 1–2 and three with 4–6 lesions) were planned using RapidArc for both Varian Millennium 120 MLC (5 mm leaf width) and high definition (HD) MLC (2.5 mm leaf width). Between 2 and 8 arcs were used with two full coplanar arcs and the rest non-coplanar half arcs. 6 MV beams were used and plans were optimized with a high priority to the Normal Tissue Objective (tomore » achieve dose conformity and sharp dose fall-off) and normal brain tissue. Calculation was done using AAA on a 1 mm grid size. The prescription dose ranged from 14–22 Gy. Plans were normalized such that 99% of the target received the prescription dose. Identical beam geometries, optimizations, calculations, and normalizations were used for both plans. Paddick Conformity Index (PCI), V4, V8 and V12 Gy for normal brain tissue and Integral Dose were used for analysis. Results: In all cases, HD MLC plans performed better in sparing normal brain tissue, achieving a higher PCI with a lower Integral Dose. The average PCI for all 24 targets was 0.75±0.23 and 0.70±0.23 (p ≤0.0015) for HD MLC and Millennium MLC plans, respectively. The average ratio of normal brain doses for Millennium MLC to HD MLC plans was 1.30±0.16, 1.27±0.15, and 1.31±0.18 for the V4, V8, and V12, respectively. The differences in normal brain dose for all criteria were statistically significant with p-value < 0.02. On average Millennium MLC plans had a 16% higher integral dose than HD MLC plans. Conclusion: Significantly better dose conformity with reduced volume of normal brain tissue and integral dose was achieved with HD MLC plans compared to Millennium MLC plans.« less

A maximum contraction and substantial quantities of tritium can be obtained from tetraethylammonium-treated [3H]-noradrenaline preloaded, rat vas deferens in response to a single electrical shock.

PubMed Central

Wakade, A. R.

1980-01-01

1 In the normal and phenoxybenzamine-treated vasa deferentia of the rat the overflow of tritium after preloading with [3H]-noradrenaline increased with the increase in frequency of transmural stimulation. Phenozybenzamine enhanced overflow by 5 to 7 fold. 2 After tetraethylammonium (TEA, 10 mM), fractional tritium overflow at 5 Hz increased from a control value of 2.8 to 53 X 10(-4), and at 0.5 Hz it reached 154 X 10(-4). Enhancement of overflow was inversely related to the frequency of stimulation. 3 Contractor responses of the vas deferens induced by transmural stimulation were markedly potentiated, both in amplitude and duration, by 10 mM TEA. The contraction developed in the presence of 10 mM TEA at 0.5 Hz was comparable to that obtained at 10 Hz in normal Krebs solution. 4 In the presence of 5 mM TEA, contractions of the vas deferens caused by exogenous noradrenaline were potentiated about 5 fold. 5 The overflow and contractor response induced by 45 mM K were enhanced about 5 fold in 10 mM TEA-Krebs solution. Facilitation of K-induced overflow by TEA was reduced over 50% by tetrodotoxin (TTX, 1 microM). 6 Delivery of a single shock (1.0 ms duration) to 10 mM TEA-treated vas deferens resulted in a 63% increase in tritium overflow over background overflow. The fractional overflow amounted to almost 720 X 10(-4) after a single shock, as compared to 154 X 10(-4) obtained at 0.5 Hz. 7 The vas deferens treated with 10 mM TEA and stimulated by a single shock developed a contraction which was greater in amplitude and duration than that seen in normal tissue at 10 Hz. 8 Five second serial samples collected from superfused 10 mM TEA-treated vas deferens contained maximum quantities of radioactivity in the first 5 s after a single shock. In subsequent samples, radioactivity gradually declined, and reached prestimulation level after about 25 s. 9 The fractional overflow caused by stimulation at 0.1 Hz in 10 mM TEA-treated tissue progressively increased as external Ca was gradually raised from 0.83 to 10 mM. 10 The mechanism of action of TEA in enhancing the overflow of sympathetic transmitter, particularly in response to a single shock, is discussed in relation to Ca. PMID:7052336

Infrared ocular thermography in dogs with and without keratoconjunctivitis sicca.

PubMed

Biondi, Flávia; Dornbusch, Peterson T; Sampaio, Manuella; Montiani-Ferreira, Fabiano

2015-01-01

Infrared thermography was used to measure temperature differences of the corneal surface between nasal and temporal limbus regions and central cornea of normal dogs and dogs with keratoconjunctivitis sicca (KCS), in order to establish temperature values in normal canine eyes and in patients with decreased Schirmer tear tests (STT) values. Dogs investigated were all either patients seen at the Veterinary Teaching Hospital of Federal University of Paraná or normal dogs that belonged to the same institution. STT were performed in all eyes. A total of 40 control eyes (STT ≥15 mm/min) and 20 eyes with low STT values (STT ≤14 mm/min) were examined. The mean STT value for eyes with normal STT values was 22.9 ± 3.9 mm/min (mean ± standard deviation), and the mean STT value for eyes with low STT value was 7.2 ± 4.8 mm/min. The mean corneal temperature was significantly lower in eyes with low STT values than in control eyes (P < 0.0001). The following significant correlations were found: (i) Schirmer and breakup time (BUT) (P = 0.0001, r = 0.5); (ii) STT values and corneal surface temperature (P = 0.001, r = 0.256); (iii) STT values and age (P = 0.0001, r = -0.448); (iv) age and corneal surface temperature (P = 0.0001, r = -0.281); and (v) BUT and corneal surface temperature (P = 0.0001, r = 0.36). Thermography is a method that can differentiate between eyes with normal and abnormal STT values. In the future, thermography might be incorporated as part of the ophthalmic examination and perhaps become a popular ancillary test for the diagnoses of ocular surface disorders. © 2013 American College of Veterinary Ophthalmologists.

Posterior Displacement of Supraspinatus Central Tendon Observed on Magnetic Resonance Imaging: A Useful Preoperative Indicator of Rotator Cuff Tear Characteristics.

PubMed

Updegrove, Gary F; Armstrong, April D; Mosher, Timothy J; Kim, H Mike

2015-11-01

To characterize the orientation of the normal supraspinatus central tendon and describe the displacement patterns of the central tendon in rotator cuff tears using a magnetic resonance imaging (MRI)-based method. We performed a retrospective MRI and chart review of 183 patients with a rotator cuff tear (cuff tear group), 52 with a labral tear but no rotator cuff tear (labral tear group), and 74 with a normal shoulder (normal group). The orientation of the supraspinatus central tendon relative to the bicipital groove was evaluated based on axial MRI and was numerically represented by the shortest distance from the lateral extension line of the central tendon to the bicipital groove. Tear size, fatty degeneration, and involvement of the anterior supraspinatus were evaluated to identify the factors associated with orientation changes. The mean distance from the bicipital groove to the central tendon line was 0.7 mm and 1.3 mm in the normal group and labral tear group, respectively. Full-thickness cuff tears involving the anterior supraspinatus showed a significantly greater distance (17.7 mm) than those sparing the anterior supraspinatus (4.9 mm, P = .001). Fatty degeneration of the supraspinatus was significantly correlated with the distance (P = .006). Disruption of the anterior supraspinatus and fatty degeneration of the supraspinatus were independent predictors of posterior displacement. The supraspinatus central tendon has a constant orientation toward the bicipital groove in normal shoulders, and the central tendon is frequently displaced posteriorly in full-thickness rotator cuff tears involving the anterior leading edge of the supraspinatus. The degree of posterior displacement is proportional to tear size and severity of fatty degeneration of the supraspinatus muscle. A simple and quick assessment of the central tendon orientation on preoperative MRI can be a useful indicator of tear characteristics, potentially providing insight into the intraoperative repair strategy. Level IV, diagnostic case-control study. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Effects of insulin under normal and low glucose on retinal electrophysiology in the perfused cat eye.

PubMed

Lansel, N; Niemeyer, G

1997-04-01

To investigate the short-term effects of fast-acting insulin on the electroretinogram-b-wave, optic nerve response, standing potential, and flow rate in the arterially perfused cat eye under normal conditions and during low glucose levels. Enucleated cat eyes were perfused with a glucose- and insulin-free tissue culture medium, to which glucose was applied at normal (5.5 mM) and reduced (2 and 1 mM) concentrations. Photic stimulation was performed in the rod-matched intensity range before, during, and after insulin application at postprandial (5 ng/ml) and at 10 and 20 x higher concentrations. Insulin failed to affect retinal signals at normal glucose levels. However, insulin enhanced the low glucose-induced decrease in rod-driven b-wave amplitude (P < 0.05 at 2 mM; P < 0.01 at 1 mM) without affecting the corresponding changes in the optic nerve response. The standing potential increased by as much as 0.75 mV in response to insulin. The perfusate flow rate was not altered by insulin. Insulin was not required for normal retinal function as observed during 10 hours of perfusion. The differential responsiveness to insulin under low glucose of the b-wave versus the optic nerve response is thought to reflect suppression of glucose use by Müller (glial) cells rather than neuromodulation, as the neuronal optic nerve response is unaffected. The postulated insulin sensitivity of Müller cells (changes in b-wave amplitude) indicates a possible difference in the mechanism of glucose metabolism of glia versus neurons. The electrophysiological effect of insulin under low glucose suggests its passage across the blood-retina barrier. The increase in the standing potential is likely to be a receptor-mediated retinal pigment epithelium effect. These results provide evidence in the retina for the reported multifunctional nature of the insulin receptor.

The Mars Science Laboratory (MSL) Mast cameras and Descent imager: Investigation and instrument descriptions.

PubMed

Malin, Michal C; Ravine, Michael A; Caplinger, Michael A; Tony Ghaemi, F; Schaffner, Jacob A; Maki, Justin N; Bell, James F; Cameron, James F; Dietrich, William E; Edgett, Kenneth S; Edwards, Laurence J; Garvin, James B; Hallet, Bernard; Herkenhoff, Kenneth E; Heydari, Ezat; Kah, Linda C; Lemmon, Mark T; Minitti, Michelle E; Olson, Timothy S; Parker, Timothy J; Rowland, Scott K; Schieber, Juergen; Sletten, Ron; Sullivan, Robert J; Sumner, Dawn Y; Aileen Yingst, R; Duston, Brian M; McNair, Sean; Jensen, Elsa H

2017-08-01

The Mars Science Laboratory Mast camera and Descent Imager investigations were designed, built, and operated by Malin Space Science Systems of San Diego, CA. They share common electronics and focal plane designs but have different optics. There are two Mastcams of dissimilar focal length. The Mastcam-34 has an f/8, 34 mm focal length lens, and the M-100 an f/10, 100 mm focal length lens. The M-34 field of view is about 20° × 15° with an instantaneous field of view (IFOV) of 218 μrad; the M-100 field of view (FOV) is 6.8° × 5.1° with an IFOV of 74 μrad. The M-34 can focus from 0.5 m to infinity, and the M-100 from ~1.6 m to infinity. All three cameras can acquire color images through a Bayer color filter array, and the Mastcams can also acquire images through seven science filters. Images are ≤1600 pixels wide by 1200 pixels tall. The Mastcams, mounted on the ~2 m tall Remote Sensing Mast, have a 360° azimuth and ~180° elevation field of regard. Mars Descent Imager is fixed-mounted to the bottom left front side of the rover at ~66 cm above the surface. Its fixed focus lens is in focus from ~2 m to infinity, but out of focus at 66 cm. The f/3 lens has a FOV of ~70° by 52° across and along the direction of motion, with an IFOV of 0.76 mrad. All cameras can acquire video at 4 frames/second for full frames or 720p HD at 6 fps. Images can be processed using lossy Joint Photographic Experts Group and predictive lossless compression.

The Mars Science Laboratory (MSL) Mast cameras and Descent imager: Investigation and instrument descriptions

PubMed Central

Ravine, Michael A.; Caplinger, Michael A.; Tony Ghaemi, F.; Schaffner, Jacob A.; Maki, Justin N.; Bell, James F.; Cameron, James F.; Dietrich, William E.; Edgett, Kenneth S.; Edwards, Laurence J.; Garvin, James B.; Hallet, Bernard; Herkenhoff, Kenneth E.; Heydari, Ezat; Kah, Linda C.; Lemmon, Mark T.; Minitti, Michelle E.; Olson, Timothy S.; Parker, Timothy J.; Rowland, Scott K.; Schieber, Juergen; Sletten, Ron; Sullivan, Robert J.; Sumner, Dawn Y.; Aileen Yingst, R.; Duston, Brian M.; McNair, Sean; Jensen, Elsa H.

2017-01-01

Abstract The Mars Science Laboratory Mast camera and Descent Imager investigations were designed, built, and operated by Malin Space Science Systems of San Diego, CA. They share common electronics and focal plane designs but have different optics. There are two Mastcams of dissimilar focal length. The Mastcam‐34 has an f/8, 34 mm focal length lens, and the M‐100 an f/10, 100 mm focal length lens. The M‐34 field of view is about 20° × 15° with an instantaneous field of view (IFOV) of 218 μrad; the M‐100 field of view (FOV) is 6.8° × 5.1° with an IFOV of 74 μrad. The M‐34 can focus from 0.5 m to infinity, and the M‐100 from ~1.6 m to infinity. All three cameras can acquire color images through a Bayer color filter array, and the Mastcams can also acquire images through seven science filters. Images are ≤1600 pixels wide by 1200 pixels tall. The Mastcams, mounted on the ~2 m tall Remote Sensing Mast, have a 360° azimuth and ~180° elevation field of regard. Mars Descent Imager is fixed‐mounted to the bottom left front side of the rover at ~66 cm above the surface. Its fixed focus lens is in focus from ~2 m to infinity, but out of focus at 66 cm. The f/3 lens has a FOV of ~70° by 52° across and along the direction of motion, with an IFOV of 0.76 mrad. All cameras can acquire video at 4 frames/second for full frames or 720p HD at 6 fps. Images can be processed using lossy Joint Photographic Experts Group and predictive lossless compression. PMID:29098171

Evaluating Approaches to Rendering Braille Text on a High-Density Pin Display.

PubMed

Morash, Valerie S; Russomanno, Alexander; Gillespie, R Brent; OModhrain, Sile

2017-10-13

Refreshable displays for tactile graphics are typically composed of pins that have smaller diameters and spacing than standard braille dots. We investigated configurations of high-density pins to form braille text on such displays using non-refreshable stimuli produced with a 3D printer. Normal dot braille (diameter 1.5 mm) was compared to high-density dot braille (diameter 0.75 mm) wherein each normal dot was rendered by high-density simulated pins alone or in a cluster of pins configured in a diamond, X, or square; and to "blobs" that could result from covering normal braille and high-density multi-pin configurations with a thin membrane. Twelve blind participants read MNREAD sentences displayed in these conditions. For high-density simulated pins, single pins were as quickly and easily read as normal braille, but diamond, X, and square multi-pin configurations were slower and/or harder to read than normal braille. We therefore conclude that as long as center-to-center dot spacing and dot placement is maintained, the dot diameter may be open to variability for rendering braille on a high density tactile display.

Normal-phase liquid chromatography retention behavior of polycyclic aromatic hydrocarbon and their methyl-substituted derivatives on an aminopropyl stationary phase.

PubMed

Wilson, Walter B; Hayes, Hugh V; Sander, Lane C; Campiglia, Andres D; Wise, Stephen A

2017-09-01

Retention indices for 124 polycyclic aromatic hydrocarbons (PAHs) and 62 methyl-substituted (Me-) PAHs were determined using normal-phase liquid chromatography (NPLC) on a aminopropyl (NH 2 ) stationary phase. PAH retention behavior on the NH 2 phase is correlated to the total number of aromatic carbons in the PAH structure. Within an isomer group, non-planar isomers generally elute earlier than planar isomers. MePAHs generally elute slightly later but in the same region as the parent PAHs. Correlations between PAH retention behavior on the NH 2 phase and PAH thickness (T) values were investigated to determine the influence of non-planarity for isomeric PAHs with four to seven aromatic rings. Correlation coefficients ranged from r = 0.19 (five-ring peri-condensed molecular mass (MM) 252 Da) to r = -0.99 (five-ring cata-condensed MM 278 Da). In the case of the smaller PAHs (MM ≤ 252 Da), most of the PAHs had a planar structure and provided a low correlation. In the case of larger PAHs (MM ≥ 278 Da), nonplanarity had a significant influence on the retention behavior and good correlation between retention and T was obtained for the MM 278 Da, MM 302 Da, MM 328 Da, and MM 378 Da isomer sets. Graphical abstract NPLC separation of the three-, four-, five-, and six-ring PAH isomers with different number of aromatic carbon atoms and degrees of non-planarity (Thickness, T). The inserted figure plots the number of aromatic carbon atoms vs. the log I value for the 124 parent PAHs.

Change in intraocular pressure during scleral depression.

PubMed

Trevino, Richard; Stewart, Brandi

2015-01-01

Manometric studies have found that intraocular pressure (IOP) rises 116-350 mmHg during scleral depression in surgical settings. No information is available regarding the effect of scleral depression on IOP in routine clinical settings. The aim of this study is to quantify the change in IOP that occurs when scleral depression is performed on normal eyes in a routine clinical setting. A total of 28 eyes from 28 normal subjects were included. Tono-Pen tonometry was performed while scleral depression was performed in each of the two quadrants: superotemporal (ST) and inferonasal (IN). A post-procedure IOP measurement was obtained following each scleral depression examination. Both ST and IN quadrants were tested on all eyes, with the quadrant tested first chosen at random (15 ST, 13 IN). The mean IOP during scleral depression was 65.3 mmHg ST and 47.8 mmHg IN, with a maximum recorded IOP of 88 mmHg. The mean change in IOP for the ST quadrant was 51.9 ± 17.3 mmHg and 46.4 ± 16.0 mmHg for the right and left eyes, respectively. The mean change in IOP for the IN quadrant was 45.3 ± 22.7 mmHg and 16.8 ± 15.8 mmHg for the right and left eyes, respectively. Scleral depression as performed in a routine office setting produces wide fluctuations in IOP and may impair ocular perfusion. Additional studies are needed to determine the long-term consequences of routine scleral depression. Copyright © 2014 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

Patients with Dry Eye Disease and Low Subbasal Nerve Density are at High Risk for an Accelerated Corneal Endothelial Cell Loss

PubMed Central

Kheirkhah, Ahmad; Satitpitakul, Vannarut; Hamrah, Pedram; Dana, Reza

2016-01-01

Purpose To evaluate the changes in corneal endothelial cell density (CECD) over time in patients with dry eye disease (DED) and to correlate the endothelial cell loss with corneal subbasal nerve density. Methods This retrospective study included 40 eyes of 20 patients with DED. Laser in vivo confocal microscopy had been performed in the central cornea of both eyes at an initial visit and repeated after a mean follow-up of 33.2 ± 10.2 months. The densities of corneal endothelial cells and subbasal nerves were measured in both visits and compared with 13 eyes of 13 normal age-matched controls. Results At the initial visit, the DED group had lower densities of corneal endothelial cells (2620 ± 386 cells/mm2) and subbasal nerves (17.8 ± 7.5 mm/mm2) compared with the control group (2861 ± 292 cells/mm2 and 22.8 ± 3.0 mm/mm2, with P=0.08 and P=0.01, respectively). At the end of follow-up, although there was no significant change in subbasal nerve density (16.7 ± 7.2 mm/mm2, P=0.43), the mean CECD significantly decreased to 2465 ± 391 cells/mm2 (P=0.01), with a mean corneal endothelial cell loss of 2.1 ± 3.6% per year. The endothelial cell loss showed a statistically significant negative correlation with the initial subbasal nerve density (Rs= −0.55, P=0.02). Conclusion Patients with DED have an accelerated corneal endothelial cell loss which is more than what has been reported in the literature for normal aging. Those with lower subbasal nerve density, in particular, are at a higher risk for endothelial cell loss over time. PMID:28060067

Influence of different abutment diameter of implants on the peri-implant stress in the crestal bone: A three-dimensional finite element analysis--In vitro study.

PubMed

Aradya, Anupama; Kumar, U Krishna; Chowdhary, Ramesh

2016-01-01

The study was designed to evaluate and compare stress distribution in transcortical section of bone with normal abutment and platform switched abutment under vertical and oblique forces in posterior mandible region. A three-dimensional finite element model was designed using ANSYS 13.0 software. The type of bone selection for the model was made of type II mandibular bone, having cortical bone thickness ranging from 0.595 mm to 1.515 mm with the crestal region measuring 1.5 mm surrounding dense trabecular bone. The implant will be modulated at 5 mm restorative platform and tapering down to 4.5 mm wide at the threads, 13 mm long with an abutment 3 mm in height. The models will be designed for two situations: (1) An implant with a 5 mm diameter abutment representing a standard platform in the posterior mandible region. (2) An implant with a 4.5 mm diameter abutment representing platform switching in the posterior mandible region. Force application was performed in both oblique and vertical conditions using 100 N as a representative masticatory force. For oblique loading, a force of 100 N was applied at 15° from the vertical axis. von Mises stress analysis was evaluated. The results of the study showed cortical stress in the conventional and platform switching model under oblique forces were 59.329 MPa and 39.952 MPa, respectively. Cortical stress in the conventional and platform switching model under vertical forces was 13.914 MPa and 12.793 MPa, respectively. Results from this study showed the platform switched abutment led to relative decrease in von Mises stress in transcortical section of bone compared to normal abutment under vertical and oblique forces in posterior mandible region.

Effect of a Modest Weight Loss in Normalizing Blood Pressure in Obese Subjects on Antihypertensive Drugs.

PubMed

Gilardini, Luisa; Redaelli, Gabriella; Croci, Marina; Conti, Antonio; Pasqualinotto, Lucia; Invitti, Cecilia

2016-01-01

To assess the effect of a lifestyle intervention in lowering/normalizing blood pressure (BP) levels in hypertensive (controlled or not) obese patients. In this prospective observational study, 490 obese hypertensive patients, 389 controlled (BP < 140/90 mm Hg; CH) and 101 uncontrolled (BP ≥ 140/90 mm Hg; UH) attended a 3-month lifestyle intervention. Before and after the intervention we assessed weight, waist circumference, fat mass, BP, metabolic and renal variables, and physical activity. A multivariate regression model was used to determine the predictors of BP changes. 18.9% of CH and 20.0% of UH were on ≥ 3 antihypertensive drugs. Weight change (average -4.9 ± 2.7%) was independent of the antihypertensive drugs employed. Systolic BP (SBP) decreased by 23 mm Hg and diastolic BP (DBP) by 9 mm Hg, in patients with UH most of whom (89%) normalized BP levels (in 49% after a weight loss < 5%). Age, gender, whole and central obesity, concomitance of type 2 diabetes, chronic renal disease, physical activity intensification, and pharmacological therapy did not affect BP lowering. In the regression analysis with SBP change as dependent variable, weight reduction (β = 0.523, p = 0.005) and group (UH vs. CH, β = -19.40, p = 0.0005) remained associated with SBP reduction. When DBP change was entered as dependent variable, baseline uric acid remained associated with DBP reduction (β = 0.824, p < 0.05). Lifestyle interventions are useful for all obese hypertensive patients in most of whom a modest weight loss is sufficient to normalize BP levels avoiding the aggressive use of multiple antihypertensive drugs. © 2016 The Author(s) Published by S. Karger GmbH, Freiburg.

Effect of a Modest Weight Loss in Normalizing Blood Pressure in Obese Subjects on Antihypertensive Drugs

PubMed Central

Gilardini, Luisa; Redaelli, Gabriella; Croci, Marina; Conti, Antonio; Pasqualinotto, Lucia; Invitti, Cecilia

2016-01-01

Objective To assess the effect of a lifestyle intervention in lowering/normalizing blood pressure (BP) levels in hypertensive (controlled or not) obese patients. Methods In this prospective observational study, 490 obese hypertensive patients, 389 controlled (BP < 140/90 mm Hg; CH) and 101 uncontrolled (BP ≥ 140/90 mm Hg; UH) attended a 3-month lifestyle intervention. Before and after the intervention we assessed weight, waist circumference, fat mass, BP, metabolic and renal variables, and physical activity. A multivariate regression model was used to determine the predictors of BP changes. Results 18.9% of CH and 20.0% of UH were on ≥ 3 antihypertensive drugs. Weight change (average −4.9 ± 2.7%) was independent of the antihypertensive drugs employed. Systolic BP (SBP) decreased by 23 mm Hg and diastolic BP (DBP) by 9 mm Hg, in patients with UH most of whom (89%) normalized BP levels (in 49% after a weight loss < 5%). Age, gender, whole and central obesity, concomitance of type 2 diabetes, chronic renal disease, physical activity intensification, and pharmacological therapy did not affect BP lowering. In the regression analysis with SBP change as dependent variable, weight reduction (β = 0.523, p = 0.005) and group (UH vs. CH, β = −19.40, p = 0.0005) remained associated with SBP reduction. When DBP change was entered as dependent variable, baseline uric acid remained associated with DBP reduction (β = 0.824, p < 0.05). Conclusion Lifestyle interventions are useful for all obese hypertensive patients in most of whom a modest weight loss is sufficient to normalize BP levels avoiding the aggressive use of multiple antihypertensive drugs. PMID:27454447

In Vitro Study of Flow Regulation for Pulmonary Insufficiency

PubMed Central

Camp, T. A.; Stewart, K. C.; Figliola, R. S.; McQuinn, T.

2007-01-01

Given the tolerance of the right heart circulation to mild regurgitation and gradient, we study the potential of using motionless devices to regulate the pulmonary circulation. In addition, we document the flow performance of two mechanical valves. A motionless diode, a nozzle, a mechanical bileaflet valve, and a tilting disk valve were tested in a pulmonary mock circulatory system over the normal human range of pulmonary vascular resistance (PVR). For the mechanical valves, regurgitant fractions (RFs) and transvalvular pressure gradients were found to be weak functions of PVR. On the low end of normal PVR, the bileaflet and tilting disk valves fluttered and would not fully close. Despite this anomaly, the regurgitant fraction of either valve did not change significantly. The values for RF and transvalvular gradient measured varied from 4 to 7% and 4 to 7 mm Hg, respectively, at 5 lpm for all tests. The diode valve was able to regulate flow with mild regurgitant fraction and trivial gradient but with values higher than either mechanical valve tested. Regurgitant fraction ranged from 2 to 17% in tests extending from PVR values of 1 to 4.5 mm Hg/lpm at 5 lpm and with concomitant increases in gradient up to 17 mm Hg. The regurgitant fraction for the nozzle increased from 2 to 23% over the range of PVR with gradients increasing to 18 mm Hg. The significant findings were: (1) the mechanical valves controlled regurgitation at normal physiological cardiac output and PVR even though they failed to close at some normal values of PVR and showed leaflet flutter; and (2) it may be possible to regulate the pulmonary circulation to tolerable levels using a motionless pulmonary valve device. PMID:17408334

Effect of Sex and Sporting Discipline on LV Adaptation to Exercise.

PubMed

Finocchiaro, Gherardo; Dhutia, Harshil; D'Silva, Andrew; Malhotra, Aneil; Steriotis, Alexandros; Millar, Lynne; Prakash, Keerthi; Narain, Rajay; Papadakis, Michael; Sharma, Rajan; Sharma, Sanjay

2017-09-01

This study sought to investigate the effect of different types of exercise on left ventricular (LV) geometry in a large group of female and male athletes. Studies assessing cardiac adaptation in female and male athletes indicate that female athletes reveal smaller increases in LV wall thickness and cavity size compared with male athletes. However, data on sex-specific changes in LV geometry in athletes are scarce. A total of 1,083 healthy, elite, white athletes (41% female; mean age 21.8 ± 5.7 years) assessed with electrocardiogram and echocardiogram were considered. LV geometry was classified into 4 groups according to relative wall thickness (RWT) and left ventricular mass (LVM) as per European and American Society of Echocardiography guidelines: normal (normal LVM/normal RWT), concentric hypertrophy (increased LVM/increased RWT), eccentric hypertrophy (increased LVM/normal RWT), and concentric remodeling (normal LVM/increased RWT). Athletes were engaged in 40 different sporting disciplines with similar participation rates with respect to the type of exercise between females and males. Females exhibited lower LVM (83 ± 17 g/m 2 vs. 101 ± 21 g/m 2 ; p < 0.001) and RWT (0.35 ± 0.05 vs. 0.36 ± 0.05; p < 0.001) compared with male athletes. Females also demonstrated lower absolute LV dimensions (49 ± 4 mm vs. 54 ± 5 mm; p < 0.001) but following correction for body surface area, the indexed LV dimensions were greater in females (28.6 ± 2.7 mm/m 2 vs. 27.2 ± 2.7 mm/m 2 ; p < 0.001). Most athletes showed normal LV geometry. A greater proportion of females competing in dynamic sport exhibited eccentric hypertrophy compared with males (22% vs. 14%; p < 0.001). In this subgroup only 4% of females compared with 15% of males demonstrated concentric hypertrophy/remodeling (p < 0.001). Highly trained athletes generally show normal LV geometry; however, female athletes participating in dynamic sport often exhibit eccentric hypertrophy. Although concentric remodeling or hypertrophy in male athletes engaged in dynamic sport is relatively common, it is rare in female athletes and may be a marker of disease in a symptomatic athlete. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Highly stable ultrabroadband mid-IR optical parametric chirped-pulse amplifier optimized for superfluorescence suppression.

PubMed

Moses, J; Huang, S-W; Hong, K-H; Mücke, O D; Falcão-Filho, E L; Benedick, A; Ilday, F O; Dergachev, A; Bolger, J A; Eggleton, B J; Kärtner, F X

2009-06-01

We present a 9 GW peak power, three-cycle, 2.2 microm optical parametric chirped-pulse amplification source with 1.5% rms energy and 150 mrad carrier envelope phase fluctuations. These characteristics, in addition to excellent beam, wavefront, and pulse quality, make the source suitable for long-wavelength-driven high-harmonic generation. High stability is achieved by careful optimization of superfluorescence suppression, enabling energy scaling.

Structural and Chemical Properties of the Nitrogen-Rich Energetic Material Triaminoguanidinium 1-methyl-5-nitriminotetrazolate under Pressure

DTIC Science & Technology

2012-08-01

Source (NSLS) of Brookhaven National Laboratory ( BNL ). The syn- chrotron light is extracted from the VUV storage ring in a 40 × 40 mrad solid angle and...Contract No. DE-AC02-06CH11357. Infrared mea- surements were performed at the U2A beamline at the NSLS of BNL (DOE Contract No. DE-AC02-98CH10886). The

Method and Process for the Creation of Modeling and Simulation Tools for Human Crowd Behavior

DTIC Science & Technology

2014-07-23

Support• Program Executive Office Ground Combat Systems • Program Executive Office Soldier TACOM LCMC MG Michael J. Terry Assigned/Direct Support...environmental technologies and explosive ordnance disposal Fire Control: Battlefield digitization; embedded system software; aero ballistics and...MRAD – Handheld stand-off NLW operated by Control Force • Simulated Projectile Weapon • Simulated Handheld Directed Energy NLW ( VDE ) – Simulated

Aureole lidar: Design, operation, and comparison with in-situ measurements

NASA Astrophysics Data System (ADS)

Hooper, William P.; Jensen, D. R.

1992-07-01

In 1986, H. Berber and Hooper examined the signals that could be detected by an airborne lidar flying above the marine boundary layer (MBL). One signal (aureole) formed from laser light returned to the receiver after a reflect off the ocean and forward scatter off the aerosol particles appeared to be both detectable and related to the optical depth of the MBL. Now, research has been directed towards developing a practical instrument to measure the aureole and finding an algorithm to use the information. Unlike the lidar backscatter which typically requires a telescope with a narrow field of view (0.5 mrad), the aureole signal occurs over a wide field of view (50 mrad). To accommodate the totally different needs, a standard commercial Cassegrainian telescope was modified to yield a telescope with two focal planes. The secondary mirror was replaced by a lens, whose front surface was half silvered and curved to match the replaced mirror. Light reflecting off the lens focused behind the primary mirror. The back lens surface was curved to allow unreflected light to focus at the natural focus of the primary mirror. This focal plane which is behind the lens has a wide field of view. To calculate an extinction profile, the aureole optical depth estimate is combined with the lidar backscatter profile.

Aureole lidar: Design, operation, and comparison with in-situ measurements

NASA Technical Reports Server (NTRS)

Hooper, William P.; Jensen, D. R.

1992-01-01

In 1986, H. Berber and Hooper examined the signals that could be detected by an airborne lidar flying above the marine boundary layer (MBL). One signal (aureole) formed from laser light returned to the receiver after a reflect off the ocean and forward scatter off the aerosol particles appeared to be both detectable and related to the optical depth of the MBL. Now, research has been directed towards developing a practical instrument to measure the aureole and finding an algorithm to use the information. Unlike the lidar backscatter which typically requires a telescope with a narrow field of view (0.5 mrad), the aureole signal occurs over a wide field of view (50 mrad). To accommodate the totally different needs, a standard commercial Cassegrainian telescope was modified to yield a telescope with two focal planes. The secondary mirror was replaced by a lens, whose front surface was half silvered and curved to match the replaced mirror. Light reflecting off the lens focused behind the primary mirror. The back lens surface was curved to allow unreflected light to focus at the natural focus of the primary mirror. This focal plane which is behind the lens has a wide field of view. To calculate an extinction profile, the aureole optical depth estimate is combined with the lidar backscatter profile.

The design of the new IR beamline at ASTRID2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Zheshen, E-mail: zsli@phys.au.dk; Hoffmann, Søren Vrønning; Rieger, Peter

2016-07-27

We report on the successful design, installation and commission of the new AU-IR beam line at ASTRID2. ASTRID2 is the new synchrotron facility running at top-up mode and at 580 MeV, which is optimized for low energies at Aarhus University, Denmark. The highlight of the beam line is that it is simple, low cost and reliable. The optics system consists of two gold-coated mirrors only and is as close as 1.367 m away from an entrance edge of a bending magnet. This allows a horizontal acceptance angle of 35 mrad and a vertical acceptance of 28 mrad. The source pointmore » is chosen to be near the leading edge of the bending magnet where the electron beam enters the dipole field. This allows us to use the strong edge radiation from the bending magnet together with the bending radiation. The beam line is equipped with a Vertex{sup TM} 70v FTIR spectrometer from Bruker{sup TM}. The beam line design and choice of the “rock-solid” optical design version of spectrometer ensure a good reliability to beam drift and vibrations. Currently, the system is running at mid-range IR. Further upgrades have been planned.« less

Angular non-critical phase-matching second-harmonic-generation characteristics of RECOB (RE = Tm, Y, Gd, Sm, Nd and La) crystals.

PubMed

Liu, Yanqing; Wang, Zhengping; Yu, Fapeng; Qi, Hongwei; Yang, Xiuqin; Yu, Xiaoqiang; Zhao, Xian; Xu, Xinguang

2017-05-15

For the first time, the angular non-critical phase-matching (A-NCPM) second-harmonic-generation (SHG) characteristics of a family of monoclinic oxoborate crystals, RECa 4 O(BO 3 ) 3 (RECOB, RE = Tm, Y, Gd, Sm, Nd and La), were comprehensively investigated. For all of the realizable A-NCPM SHG styles, the feature parameters including PM wavelength, angular, wavelength and temperature acceptance bandwidths, have been derived from the theory and verified by the experiments. We discovered that the closer the ion radius between RE 3+ and Ca 2+ , the smaller the birefringence, and the better the A-NCPM SHG properties. As a result, for the Type-I SHG on Y-axis which has the largest effective nonlinear optical coefficient (d eff ) among the three realizable A-NCPM styles, NdCOB crystal presents the longest PM wavelength (927 nm), the largest angular acceptance bandwidth (Δθ⋅l 1/2 = 84.3 mrad·cm 1/2 , Δϕ⋅l 1/2 = 58.8 mrad·cm 1/2 ), and the broadest wavelength acceptance bandwidth (8.7 nm). This discovery will contribute to the design of new NCPM materials, at the same time the parameter formula will be helpful for the theoretical prediction of NCPM performance.