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Sample records for 125-mm lbimduga likeketaste

  1. Advanced Applications Flight Equipment (AAFE) 125mm ultraviolet spectrometer

    NASA Technical Reports Server (NTRS)

    Schroeder, R. J.

    1973-01-01

    The conceptual work is reported for the 125 mm ultraviolet spectrometer to measure atmospheric ozone as a function of height, latitude, and time. The instrument is described along with the assembly, test, and calibration.

  2. Parametric Study On The CW Nd: YAG Laser Cutting Quality Of 1.25 mm Ultra Low Carbon Steel Sheets Using O2 Assist Gas

    NASA Astrophysics Data System (ADS)

    Salem, Hanadi G.; Abbas, Wafaa A.; Mansour, Mohy S.; Badr, Yehia A.

    2007-02-01

    There are many non-linear interaction factors responsible for the performance of the laser cutting process. Identification of the dominant factors that significantly affect the cut quality is important. In the current research, the gas pressure, laser power and scanning speed were selected as the cutting parameters. Effect of the cutting parameters on the cut quality was investigated, by monitoring the variation in hardness, oxide layer width and microstructural changes within the heat affected zone (HAZ). Results revealed that good quality cuts can be produced in ultra low carbon steel thin sheets, using CW Nd:YAG laser at a window of scanning speed ranging from 1100-1500 mm/min at a minimum heat input of 337watts under an assisting O2 gas pressure of 5 bar. Higher laser power resulted in either strengthening or softening in the HAZ surrounding the cut kerf. The oxide layer width is not affected by the energy density input but rather affected by the O2 gas pressure due to exothermal reaction.

  3. THE RELATIONSHIP BETWEEN REAL-TIME AND TIME-INTEGRATED COARSE (2.5-10MM), INTERMEDIATE (1-2.5MM), AND FINE (<2.5MM) PARTICULATE MATTER IN THE LOS ANGELES BASIN

    EPA Science Inventory

    Population exposure to ambient particulate matter (PM) has received considerable attention due to the association between ambient particulate concentrations and mortality. Current toxicological and epidemiological studies and controlled human and animal exposures suggest that a...

  4. 16 CFR 1512.15 - Requirements for seat.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... part of the seat, seat supports, or accessories attached to the seat shall be more than 125 mm (5.0 in... axis. This requirement does not apply to recumbent bicycles. (b) Seat post. The seat post shall...

  5. 16 CFR 1512.15 - Requirements for seat.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... part of the seat, seat supports, or accessories attached to the seat shall be more than 125 mm (5.0 in... axis. (b) Seat post. The seat post shall contain a permanent mark or ring that clearly indicates...

  6. Parameter comparison of white matter diffusion tensor imaging (DTI) in rhesus macaques (Macaca mulatta)

    PubMed Central

    MO, Yin; CHAO, Fang; SONG, Ming; LIU, Ci-Rong; LIU, Hui-Lang; QIAN, Xi-Ying; ZHAO, Xu-Dong

    2014-01-01

    In this study, we analyzed diffusion tensor imaging (DTI) results of brain white matter in rhesus macaques (Macaca mulatta) with four different parameter settings and found that the sequence A (b=1 000 s/mm2, spatial resolution=1.25 mm×1.25 mm× 1.25 mm, numbers of direction=33, NSA=3) and B (b=800 s/mm2, spatial resolution=1.25 mm×1.25 mm×1.25 mm, numbers of direction=33, NSA=3) could accurately track coarse fibers. The fractional anisotropy (FA) derived from sequence C (b=1 000s/mm2, spatial resolution=0.55 mm×0.55 mm×2.5 mm, direction number=33, NSA=3) was too fuzzy to be used in tracking white matter fibers. By comparison, the high resolution and the FA with high contrast of gray matter and white matter derived from sequence D (b=800 s/mm2, spatial resolution=1.0 mm×1.0 mm ×1.0 mm, numbers of direction=33, NSA=3) qualified in its application in tracking both thick and thin fibers, making it an optimal DTI setting for rhesus macaques. PMID:24866488

  7. The effects of metamaterial on electromagnetic fields absorption characteristics of human eye tissues.

    PubMed

    Gasmelseed, Akram; Yunus, Jasmy

    2014-01-01

    The interaction of a dipole antenna with a human eye model in the presence of a metamaterial is investigated in this paper. The finite difference time domain (FDTD) method with convolutional perfectly matched layer (CPML) formulation have been used. A three-dimensional anatomical model of the human eye with resolution of 1.25 mm × 1.25 mm × 1.25 mm was used in this study. The dipole antenna was driven by modulated Gaussian pulse and the numerical study is performed with dipole operating at 900 MHz. The analysis has been done by varying the size and value of electric permittivity of the metamaterial. By normalizing the peak SAR (1 g and 10 g) to 1 W for all examined cases, we observed how the SAR values are not affected by the different permittivity values with the size of the metamaterial kept fixed.

  8. High Efficiency, Low Cost Solar Cells Manufactured Using 'Silicon Ink' on Thin Crystalline Silicon Wafers

    SciTech Connect

    Antoniadis, H.

    2011-03-01

    Reported are the development and demonstration of a 17% efficient 25mm x 25mm crystalline Silicon solar cell and a 16% efficient 125mm x 125mm crystalline Silicon solar cell, both produced by Ink-jet printing Silicon Ink on a thin crystalline Silicon wafer. To achieve these objectives, processing approaches were developed to print the Silicon Ink in a predetermined pattern to form a high efficiency selective emitter, remove the solvents in the Silicon Ink and fuse the deposited particle Silicon films. Additionally, standard solar cell manufacturing equipment with slightly modified processes were used to complete the fabrication of the Silicon Ink high efficiency solar cells. Also reported are the development and demonstration of a 18.5% efficient 125mm x 125mm monocrystalline Silicon cell, and a 17% efficient 125mm x 125mm multicrystalline Silicon cell, by utilizing high throughput Ink-jet and screen printing technologies. To achieve these objectives, Innovalight developed new high throughput processing tools to print and fuse both p and n type particle Silicon Inks in a predetermined pat-tern applied either on the front or the back of the cell. Additionally, a customized Ink-jet and screen printing systems, coupled with customized substrate handling solution, customized printing algorithms, and a customized ink drying process, in combination with a purchased turn-key line, were used to complete the high efficiency solar cells. This development work delivered a process capable of high volume producing 18.5% efficient crystalline Silicon solar cells and enabled the Innovalight to commercialize its technology by the summer of 2010.

  9. Dollar Summary of Federal Supply Classification and Service Category by Company, FY83, Part 1 (1005-5811).

    DTIC Science & Technology

    1983-01-01

    MACHINING INC OHIO ARMY GUNS THROUGH 30 MM 49 LIO01S CLUB I NDU MINNESOTA ARMY GUNS THROUGH 30 MM 1,119 PING CO WISCONSIN ARMY GUNS THROUGH 30 MM 35...PETRALLOY CORP NC WISCONSIN USAF GUNS THROUGH 30 i 164 PRECISION INTERP INC KENTUCKY ARMY GUNS THROUGH 30 MM 52 PRECISION PRODUC NEW YORK DLA GUNS THROUGH...1015 (CONTINUED J K W MACI OKLAHOMA ARMY GUNS 75 MM THROUGH 125MM S26 JO BAR MFI WISCONSIN ARMY GUNS 75 MM THROUGH 125 MM 36 K D I ELE

  10. Oviduct binding ability of porcine spermatozoa develops in the epididymis and can be advanced by incubation with caudal fluid.

    PubMed

    Peña, Santiago; Summers, Phillip; Gummow, Bruce; Paris, Damien B B P

    2015-06-01

    The sperm reservoir is formed when spermatozoa bind to the epithelium of the uterotubal junction and caudal isthmus of the oviduct. It is an important mechanism that helps synchronize the meeting of gametes by regulating untimely capacitation and polyspermic fertilization. This study investigated the influence of epididymal maturation and caudal fluid on the ability of spermatozoa to bind to oviduct epithelium using a model porcine oviduct explant assay. Spermatozoa from the rete testis, middle caput (E2-E3), middle corpus (E6), and cauda (E8) of Large White or Large White × Landrace boars aged 10 to 14 months were diluted in modified Androhep solution and incubated with porcine oviduct explants. Results reported in this study support our hypothesis that testicular spermatozoa need to pass through the regions of the epididymis to acquire the ability to bind to the oviduct. There was a sequential increase in the number of spermatozoa that bound to oviduct explants from the rete testis to caudal epididymis. Binding of caudal spermatozoa to isthmic explants was the highest (15.0 ± 1.2 spermatozoa per 1.25 mm(2), mean ± standard error of the mean; P ≤ 0.05) and lowest by spermatozoa from the rete testis (2.0 ± 0.3 per 1.25 mm(2)), and higher to isthmus from sows compared to gilts (35.8 ± 6.7 per 1.25 mm(2) vs. 14.8 ± 3.0 per 1.25 mm(2); P ≤ 0.05). Binding of ejaculated spermatozoa to porcine isthmus was higher than that for caudal spermatozoa (26.3 ± 1.4 per 1.25 mm(2) vs. 15.0 ± 0.8 per 1.25 mm(2); P ≤ 0.05) and higher to porcine than to bovine isthmus (26.3 ± 2.3 per 1.25 mm(2) vs. 18.8 ± 1.9 per 1.25 mm(2); P ≤ 0.05). Incubation of spermatozoa from the caput and corpus in caudal fluid increased the ability of spermatozoa to bind to the oviduct epithelium (P ≤ 0.05). In conclusion, the capacity of testicular spermatozoa to bind to the oviduct epithelium increases during their maturation in the epididymis and can be advanced by components of the caudal fluid.

  11. Radiation Resistance of Asporogenous Bacteria in Frozen Beef

    DTIC Science & Technology

    1976-03-01

    temperature was indicated as -300 C the range was +100 C. The temperature was monitored by means of a thermocouple and 2 appropriate recorder. When vacuum ... packaging was employed, sealing was at 125 mm mercury pressure. ,, Isolation procedure - Samples of ground beef were packaged in flexible polyethylene

  12. 78 FR 49878 - Endangered and Threatened Wildlife and Plants; Endangered Status for the Florida Leafwing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-15

    ... darker coloring along the wing margins than the males. The butterfly also has seasonal forms (Comstock... length with a forewing length of 10.0 to 12.5 mm (0.4 to 0.5 in) and has an appearance (i.e., dark gray... classified into two ] separate groups. The Type A subspecies are larger, darker colored and are found in...

  13. When a Burr Can Not Penetrate the Calcified Lesion, Increasing Burr Size as Well as Decreasing Burr Size Can Be a Solution in Rotational Atherectomy.

    PubMed

    Sakakura, Kenichi; Taniguchi, Yousuke; Yamamoto, Kei; Wada, Hiroshi; Momomura, Shin-Ichi; Fujita, Hideo

    2017-03-02

    In rotational atherectomy (RA), several burr sizes are available, such as 1.25 mm, 1.5 mm, 1.75 mm, or ≥ 2.0 mm. It is important to select an appropriate burr size for each lesion because rotational atherectomy has several unique complications regarding burrs such as entrapment or perforation. When a burr cannot penetrate the lesion, downsizing of the burr is generally recommended. Also, if the smallest burr (1.25 mm) cannot penetrate the lesion, a change to a more supportive or larger French guiding catheter has been recommended. We describe the case of a 68 year-old female who was referred to our department for percutaneous coronary intervention to the calcified stenosis in the middle of the left anterior descending coronary artery. We used the smallest burr (1.25 mm) and a supportive 7 Fr guiding catheter to penetrate the lesion. However, the smallest burr could not pass the lesion even after 14 sessions (total ablation time: 339 seconds). We intentionally increased the burr size from 1.25 mm to 1.5 mm. The 1.5 mm burr successfully passed the lesion without any perforation or burr entrapment. In this manuscript, we discuss why increasing the burr size was successful for this severely calcified lesion that was not penetrated by the smallest burr.

  14. Design optimization of liquid scintillator cosmic-ray veto detector with BBQ shifter

    SciTech Connect

    Kruse, H.W.; Egdorf, S.S.; Simmons, D.F.

    1981-10-01

    Certain design characteristics of a liquid scintillator detector for charged cosmic particles, have been studied. These include evaluation of scintillator emission spectra, absorption in various thicknesses of BBQ shifter bars and effective transmission in long lengths of BBQ acrylic. For our BBQ sample, 12.5 mm thick with semicircular shape, the shifted light was transmitted with 2.0 m absorption length.

  15. High temperature lubricant screening and systems studies

    NASA Technical Reports Server (NTRS)

    Jones, D. A.

    1973-01-01

    Four candidate lubricants for next generation aircraft gas turbine application were tested under open atmosphere conditions in a rig simulating an advanced engine 125 mm bore mainshaft thrust bearing position. Testing was conducted at speeds to 24,000 rpm (3,000,000 bearing DN), bearing ring temperature of 500 F, and with 1200 F air and 100 psi differential pressure across the seals installed in a dual tandem arrangement. Test bearing was a 125 mm bore split inner ring, outer race riding angular contact ball bearing under a 3280 lb. thrust load. One lubricant, a type 2 ester, performed extremely well. The mainshaft seal limited the performance. Numerous design improvements for this seal were indicated.

  16. Five degree-of-freedom control of an ultra-precision magnetically-suspended linear bearing. Ph.D. Thesis - MIT

    NASA Technical Reports Server (NTRS)

    Trumper, David L.; Slocum, A. H.

    1991-01-01

    The authors constructed a high precision linear bearing. A 10.7 kg platen measuring 125 mm by 125 mm by 350 mm is suspended and controlled in five degrees of freedom by seven electromagnets. The position of the platen is measured by five capacitive probes which have nanometer resolution. The suspension acts as a linear bearing, allowing linear travel of 50 mm in the sixth degree of freedom. In the laboratory, this bearing system has demonstrated position stability of 5 nm peak-to-peak. This is believed to be the highest position stability yet demonstrated in a magnetic suspension system. Performance at this level confirms that magnetic suspensions can address motion control requirements at the nanometer level. The experimental effort associated with this linear bearing system is described. Major topics are the development of models for the suspension, implementation of control algorithms, and measurement of the actual bearing performance. Suggestions for the future improvement of the bearing system are given.

  17. Energy resolution measurements of LaBr 3:Ce scintillating crystals with an ultra-high quantum efficiency photomultiplier tube

    NASA Astrophysics Data System (ADS)

    Pani, R.; Cinti, M. N.; Scafè, R.; Pellegrini, R.; Vittorini, F.; Bennati, P.; Ridolfi, S.; Lo Meo, S.; Mattioli, M.; Baldazzi, G.; Pisacane, F.; Navarria, F.; Moschini, G.; Boccaccio, P.; Orsolini Cencelli, V.; Sacco, D.

    2009-10-01

    The performance of the new prototype of high quantum efficiency PMT (43% at 380 nm), Hamamatsu R7600U-200, was studied coupled to a LaBr 3:Ce crystal with the size of ∅12.5 mm×12.5 mm. The energy resolution results were compared with ones from two PMTs, Hamamatsu R7600U and R6231MOD, with 22% and 30% quantum efficiency (QE), respectively. Moreover, the photodetectors were equipped with tapered and un-tapered voltage dividers to study the non-linearity effects on pulse height distribution, due to very high peak currents induced in the PMT by the fast and intense light pulse of LaBr 3:Ce. The results show an energy resolution improvement with UBA PMT of about 20%, in the energy range of 80-662 keV, with respect to the BA one.

  18. Brush-like Discharge Extending from a Grounded Electrode toward a Large-scale Charged Particle Cloud

    NASA Astrophysics Data System (ADS)

    Toki, Kenji; Migita, Shin-Ichi; Higashiyama, Yoshio

    Electrostatic discharge occurring between a large-scale charged particle cloud and a grounded spherical electrode was investigated. The charged particle cloud was formed by the cloud generators consisting of a blower and a corona charger. To cause electrostatic discharges between the cloud and a grounded electrode with reproducibility, the grounded spherical electrode with 100 or 125 mm in diameter was set at the outside of the cloud. The charge quantity in a charged particle cloud affected the number of discharges, discharge current and charge quantity. Under the condition of applied voltage to the corona charger of 19 kV, peak value of discharge current for the electrode of 100 and 125 mm diameter was 3.0 and 4.8 A and the charge quantities neutralized in a single discharge was 1.9 and 2.4 μC, respectively. The peak current depends strongly on the diameter of the spherical electrode.

  19. Influence of Weld Porosity on the Integrity of Marine Structures

    DTIC Science & Technology

    1989-02-01

    Bruce Mustain Mr. Alexander B . Stavov; U. S. MERCHANT MARINE ACADEMY NATIONAL ACADEMY OF SCIENCES Dr. C. B . Kim COMMITTEE ON MARINE STRUCTURE,, U. S...FIGURE 9(a). STRESS-LIFE PLOT SHOWING ACTUAL FATIGUE LIVES VERSUS PREDICTED FATIGUE LIVES OF WELDS CONTAINING POROSITY 32 FIGURE 9( b ). STRESS-LIFE PLOT...37 FIGURE 11. CLASS A AND CLASS B POROSITY CHART FOR 0.5 INCH (12.5 MM) THICK MATERIAL ....... ...................... ... 38 FIGURE 12

  20. Studies of Rain Erosion Mechanisms in a Range of IR Transmitting Ceramics Including Coated Samples

    DTIC Science & Technology

    1991-11-01

    strength of a full size window and that the surface finish achieved on the small discs can be reproduced ,in the larger discs.,Some results from the Multiple...125 mm diameter by 5.45 mm) zinc sulphide windows rather than small (25 mm or 50 mm diameter) test pieces. The agreement between. the results for the...inspection of the surfaces revealed areas where faint grinding and polishing marks were visible. The fracture stress results are given in Table I which

  1. Inter-reader variability in alternate forced choice studies

    NASA Astrophysics Data System (ADS)

    Huda, W.; Ogden, K. M.; Samei, E.; Scalzetti, E. M.; Lavallee, R. L.; Roskopf, M. L.

    2008-03-01

    In this study, we investigated differences in detection performance for twelve observers who each generated a CT contrast detail curve. An anthropomorphic newborn phantom's abdomen was imaged using a GE Light Speed CT scanner (4-slice). Alternate Forced Choice (AFC) experiments were performed with lesions sizes ranging from 2.5 to 12.5 mm to determine the intensity needed to achieve 92% correct (I 92%). Following training, twelve readers consisting of (2 technologists, 4 college students, 4 medical students, and 2 radiology residents) generated a single contrast detail curve. Eight readers produced approximately linear contrast detail curves while the remaining four readers required a second order polynomial fit because of reduced performance when detecting the largest (i.e., 12.5 mm) lesion. For the three smallest lesions, the coefficient of variation between the twelve readers was ~12%, which increases with increasing lesion size to ~23% for 12.5 mm lesion size. The ratio of the maximum I 92% to minimum I 92% values was ~1.6 for the smallest lesions, which increased to a factor of ~2.1 for the 12.5 mm lesion. Our results show that minimizing inter-reader variability in our AFC experiments could be achieved by eliminating the largest lesion that cause detection problems in one third of observers. The combined experimental data showed that the slope of the contrast detail curve was -0.42, lower than the value of -1.0 predicted by the Rose model, suggesting that the noise texture in CT associated with both quantum mottle and anatomic structure is an important factor affecting detection of these lesions.

  2. Experimental investigation for the performance of triangular fin array within a rectangular enclosure in natural convection dominated region

    NASA Astrophysics Data System (ADS)

    Dwivedi, Ankur; Das, Debasish

    2016-12-01

    This study investigates the performance of triangular fin array within a rectangular enclosure with heated bottom wall experimentally at a wide range of Rayleigh number (295214 ≤ Ra ≤ 773410) for different fin height values (12.5 mm ≤ L ≤ 37.5 mm) and fin spacing values (25 mm ≤ S ≤ 100 mm). A new correlation is also proposed for the Nusselt number which is demonstrated the satisfactory capture of the correct qualitative behaviour of system performance.

  3. Unclassified Publications of Lincoln Laboratory 1 January-31 December 1993. Volume 19

    DTIC Science & Technology

    1993-12-31

    Nb SNAP Technology for 125 mm Wafers Developed in Partnership with Silicon Technology Rader , CM. Brown, EJR. Hollis, M.A. Smith, F.W. ffl Wang...1993, pp. 120-136 10182 Results from the Maine 1992 Toups, M.F. Foliage Penetration Experiment Ayasli, S. SPIE, Vol. 1942, Underground ...Point Source Response Hsu, C.C. Kong, J.A. Toups, M.F. Fleischman, J.G. Ayasli, S. Shin, R.T-I. SPEE, Vol. 1942, Underground and Obscured

  4. Loss of Protein, Immunoglobulins, and Electrolytes in Exudates from Negative Pressure Wound Therapy

    DTIC Science & Technology

    2010-10-01

    510 Nutrition in Clinical Practice Volume 25 Number 5 October 2010 510-516 © 2010 American Society for Parenteral and Enteral Nutrition 10.1177...sure was 184 mm Hg, and the remaining patients’ NPWT pressures were 125 mm Hg. For nutrition intake, 3 of these patients received parenteral nutrition ...therapy in the adult critically ill patient: Society of Critical Care Medicine and American Society for Parenteral and Enteral Nutrition : executive

  5. Comparative study of the microvascular blood flow in the intestinal wall, wound contraction and fluid evacuation during negative pressure wound therapy in laparostomy using the V.A.C. abdominal dressing and the ABThera open abdomen negative pressure therapy system.

    PubMed

    Lindstedt, Sandra; Malmsjö, Malin; Hlebowicz, Joanna; Ingemansson, Richard

    2015-02-01

    This study aimed to compare the changes in microvascular blood flow in the small intestinal wall, wound contraction and fluid evacuation, using the established V.A.C. abdominal dressing (VAC dressing) and a new abdominal dressing, the ABThera open abdomen negative pressure therapy system (ABThera dressing), in negative pressure wound therapy (NPWT). Midline incisions were made in 12 pigs that were subjected to treatment with NPWT using the VAC or ABThera dressing. The microvascular blood flow in the intestinal wall was measured before and after the application of topical negative pressures of −50, −75 and −125mmHg using laser Doppler velocimetry. Wound contraction and fluid evacuation were also measured. Baseline blood flow was defined as 100% in all settings. The blood flow was significantly reduced to 64·6±6·7% (P <0·05) after the application of −50mmHg using the VAC dressing, and to 65·3±9·6% (P <0·05) after the application of −50mmHg using the ABThera dressing. The blood flow was significantly reduced to 39·6±6·7% (P <0·05) after the application of −125mmHg using VAC and to 40·5±6·2% (P <0·05) after the application of −125mmHg using ABThera. No significant difference in reduction in blood flow could be observed between the two groups. The ABThera system afforded significantly better fluid evacuation from the wound, better drainage of the abdomen and better wound contraction than the VAC dressing.

  6. Output factor comparison of Monte Carlo and measurement for Varian TrueBeam 6 MV and 10 MV flattening filter-free stereotactic radiosurgery system.

    PubMed

    Cheng, Jason Y; Ning, Holly; Arora, Barbara C; Zhuge, Ying; Miller, Robert W

    2016-05-08

    The dose measurements of the small field sizes, such as conical collimators used in stereotactic radiosurgery (SRS), are a significant challenge due to many factors including source occlusion, detector size limitation, and lack of lateral electronic equilibrium. One useful tool in dealing with the small field effect is Monte Carlo (MC) simulation. In this study, we report a comparison of Monte Carlo simulations and measurements of output factors for the Varian SRS system with conical collimators for energies of 6 MV flattening filter-free (6 MV) and 10 MV flattening filter-free (10 MV) on the TrueBeam accelerator. Monte Carlo simulations of Varian's SRS system for 6 MV and 10 MV photon energies with cones sizes of 17.5 mm, 15.0 mm, 12.5 mm, 10.0 mm, 7.5 mm, 5.0 mm, and 4.0 mm were performed using EGSnrc (release V4 2.4.0) codes. Varian's version-2 phase-space files for 6 MV and 10 MV of TrueBeam accelerator were utilized in the Monte Carlo simulations. Two small diode detectors Edge (Sun Nuclear) and Small Field Detector (SFD) (IBA Dosimetry) were applied to measure the output factors. Significant errors may result if detector correction factors are not applied to small field dosimetric measurements. Although it lacked the machine-specific kfclin,fmsrQclin,Qmsr correction factors for diode detectors in this study, correction factors were applied utilizing published studies conducted under similar conditions. For cone diameters greater than or equal to 12.5 mm, the differences between output factors for the Edge detector, SFD detector, and MC simulations are within 3.0% for both energies. For cone diameters below 12.5 mm, output factors differences exhibit greater variations.

  7. Output factor comparison of Monte Carlo and measurement for Varian TrueBeam 6 MV and 10 MV flattening filter-free stereotactic radiosurgery system.

    PubMed

    Cheng, Jason Y; Ning, Holly; Arora, Barbara C; Zhuge, Ying; Miller, Robert W

    2016-05-01

    The dose measurements of the small field sizes, such as conical collimators used in stereotactic radiosurgery (SRS), are a significant challenge due to many factors including source occlusion, detector size limitation, and lack of lateral electronic equilibrium. One useful tool in dealing with the small field effect is Monte Carlo (MC) simulation. In this study, we report a comparison of Monte Carlo simulations and measurements of output factors for the Varian SRS system with conical collimators for energies of 6 MV flattening filter-free (6 MV) and 10 MV flattening filter-free (10 MV) on the TrueBeam accelerator. Monte Carlo simulations of Varian's SRS system for 6 MV and 10 MV photon energies with cones sizes of 17.5 mm, 15.0 mm, 12.5 mm, 10.0 mm, 7.5 mm, 5.0 mm, and 4.0 mm were performed using EGSnrc (release V4 2.4.0) codes. Varian's version-2 phase-space files for 6 MV and 10 MV of TrueBeam accelerator were utilized in the Monte Carlo simulations. Two small diode detectors Edge (Sun Nuclear) and Small Field Detector (SFD) (IBA Dosimetry) were applied to measure the output factors. Significant errors may result if detector correction factors are not applied to small field dosimetric measurements. Although it lacked the machine-specific kQclin,Qmsrfclin,fmsr correction factors for diode detectors in this study, correction factors were applied utilizing published studies conducted under similar conditions. For cone diameters greater than or equal to 12.5 mm, the differences between output factors for the Edge detector, SFD detector, and MC simulations are within 3.0% for both energies. For cone diameters below 12.5 mm, output factors differences exhibit greater variations. PACS number(s): 87.55.k, 87.55.Qr.

  8. Four- and Eight-Channel Aortoiliac CT Angiography: A Comparative Study

    SciTech Connect

    Karcaaltincaba, Musturay Foley, Dennis

    2005-04-15

    Purpose. To compare performance parameters, contrast material load and radiation dose in a patient cohort having aortoiliac CT angiography using 4- and 8-channel multidetector CT (MDCT) systems. Methods. Eighteen patients with abdominal aortic aneurysms underwent initial 4-channel and follow-up 8-channel MDCT angiography. Both the 4- and 8-channel MDCT systems utilized a matrix detector of 16 x 1.25 mm rows. Scan coverage included the abdominal aorta and iliac arteries to the level of the proximal femoral arteries. For 4-channel MDCT, nominal slice thickness and beam pitch were 1.25 mm and 1.5, respectively, and for 8-channel MDCT they were 1.25 mm and 1.35 or 1.65 respectively. Scan duration, iodinated contrast material load and mean aortoiliac attenuation were compared retrospectively. Comparative radiation dose measurements for 4- and 8-channel MDCT were obtained using a multiple scan average dose technique on an abdominal phantom. Results. Compared with 4-channel MDCT, 8-channel MDCT aortoiliac angiography was performed with equivalent collimation, decreased contrast load (mean 45% decrease: 144 ml versus 83 ml of 300 mg iodine/ml contrast material) and decreased acquisition time (mean 51% shorter: 34.4 sec versus 16.9 sec) without a significant change in mean aortic enhancement (299 HU versus 300 HU, p > 0.05). Radiation dose was 2 rad for the 4-channel system and 2/1.5 rad for the 8-channel system at 1.35/1.65 pitch respectively. Conclusion. Compared with 4-channel MDCT, aortoiliac CT angiography with 8-channel MDCT produces equivalent z-axis resolution with decreased contrast load and acquisition time without increased radiation exposure.

  9. Utilization of recycled glass as aggregate in controlled low-strength material (CLSM)

    SciTech Connect

    Ohlheiser, T.R.

    1998-10-01

    Incoming glass from curbside recycling programs is successfully being utilized as aggregate replacements. The colored glass that can not be used by local bottle manufacturers is crushed to a {1/2} in. (12.5 mm) material and used in various construction projects. The most successful use of processed glass aggregate (PGA) to date, has been in replacing up to 100% of the aggregate in controlled low-strength material (CLSM). It has proven to be successful and has gained acceptance by contractors in the Boulder, Colorado area.

  10. Effect of pre-strain on ratcheting behavior of A668 Class D steel

    NASA Astrophysics Data System (ADS)

    Tripathy, S.; Mondal, A. K.; Dutta, K.

    2016-02-01

    The aim of this investigation is to study the effect pre-strain (0%, 2%, 4% and 8%) on ratcheting behavior of ASTM A668 Class D steel in different heat treatment conditions (normalized and hardened-tempered). Ratcheting tests were carried out at room temperature on cylindrical specimens having 12.5 mm gauge length and 6 mm gauge diameter. The results include reduced strain accumulation with increasing prestrain level due to work hardening of the pre-strained samples. Further, cyclic hardening takes place during ratcheting deformation.

  11. Modeling of the BNL photocathode gun with the code PARMELA

    NASA Astrophysics Data System (ADS)

    Parsa, Zohreh; Young, Lloyd

    1992-07-01

    We present an analysis of the electron beam emitted from the BNL laser driven photocathode injector operating at 2856 MHz. An analysis of the beam transported through the transport line to the entrance of the linac is also presented. Recent measurements of the photocathode laser shows that the pulse length has a sigma of ±5 ps and a transverse size of 1.25 mm. A Gaussian shape is assumed for the distribution in both the radial and time dependence of the laser beam. This is compared with the original design parameters of ±2 ps and 3 mm.

  12. Measurement of Total Scatter Factor for Stereotactic Cones with Plastic Scintillation Detector

    PubMed Central

    Chaudhari, Suresh H; Dobhal, Rishabh; Kinhikar, Rajesh A.; Kadam, Sudarshan S.; Deshpande, Deepak D.

    2017-01-01

    Advanced radiotherapy modalities such as stereotactic radiosurgery (SRS) and image-guided radiotherapy may employ very small beam apertures for accurate localized high dose to target. Accurate measurement of small radiation fields is a well-known challenge for many dosimeters. The purpose of this study was to measure total scatter factors for stereotactic cones with plastic scintillation detector and its comparison against diode detector and theoretical estimates. Measurements were performed on Novalis Tx™ linear accelerator for 6MV SRS beam with stereotactic cones of diameter 6 mm, 7.5 mm, 10 mm, 12.5 mm, and 15 mm. The advantage of plastic scintillator detector is in its energy dependence. The total scatter factor was measured in water at the depth of dose maximum. Total scatter factor with plastic scintillation detector was determined by normalizing the readings to field size of 10 cm × 10 cm. To overcome energy dependence of diode detector for the determination of scatter factor with diode detector, daisy chaining method was used. The plastic scintillator detector was calibrated against the ionization chamber, and the reproducibility in the measured doses was found to be within ± 1%. Total scatter factor measured with plastic scintillation detector was 0.728 ± 0.3, 0.783 ± 0.05, 0.866 ± 0.55, 0.885 ± 0.5, and 0.910 ± 0.06 for cone sizes of 6 mm, 7.5 mm, 10 mm, 12.5 mm, and 15 mm, respectively. Total scatter factor measured with diode detector was 0.733 ± 0.03, 0.782 ± 0.02, 0.834 ± 0.07, 0.854 ± 0.02, and 0.872 ± 0.02 for cone sizes of 6 mm, 7.5 mm, 10 mm, 12.5 mm, and 15 mm, respectively. The variation in the measurement of total scatter factor with published Monte Carlo data was found to be −1.3%, 1.9%, −0.4%, and 0.4% for cone sizes of 7.5 mm, 10 mm, 12.5 mm, and 15 mm, respectively. We conclude that total scatter factor measurements for stereotactic cones can be adequately carried out with a plastic scintillation detector. Our results show a high level of consistency within our data and compared well with published data.

  13. Astrometry of STF 2448 on the Mount Wilson 1.5 m Telescope with a Novel Video Eyepiece

    NASA Astrophysics Data System (ADS)

    Estrada, Reed; Ramos, Rafael; Wasson, Rick; Carro, Joseph; Kenney, John; Estrada, Chris; Hollman, Cassie; Wallen, Vera; Tassell, Noah; Genet, Russell

    2015-07-01

    The Mt. Wilson Double Star Workshop was organized to provide a hands-on educational and research opportunity for students and amateur astronomers to learn and carry out astrometric eyepiece measurements of double stars. Due to the unique operating characteristics of the Mt Wilson 1.5 meter telescope and the limited time available for observations, a Bell & Howell DNV16HDZ high definition video camera was adapted to a Celestron 12.5mm astronomic eyepiece to record the position and separation of double star STF2448. This paper records the results of the team's observations and their techniques used to record and analyze the data.

  14. Perirectal abscess following procedure for prolapsed haemorrhoids successfully managed with a combination of VAC sponge and Redivac systems.

    PubMed

    Durai, R; Ng, P C H

    2009-12-01

    Active drains, which work from negative pressure effect, are commonly used to drain closed airtight wounds. Higher negative pressure is used in vacuum assisted wound closure (VAC) (usually -125 mmHg) dressings and in Redivac system (usually -300 mmHg). As far as we know, combinations of Redivac and VAC have not been used. The authors describe a novel combination using the sponge of the VAC dressing and sealed Redivac system to drain an open rectal wound, consequence of a perforation after stapled haemorrhoidopexy.

  15. Rail accelerators for space transportation: An experimental investigation

    NASA Technical Reports Server (NTRS)

    Zana, L. M.; Kerslake, W. R.; Sturman, J. L.

    1986-01-01

    An experimental program was conducted at the Lewis Research Center with the objective of investigating the technical feasibility of rail accelerators for propulsion applications. Single-stage, plasma driven rail accelerators of small (4 by 6 mm) and medium (12.5 by 12.5 mm) bores were tested at peak accelerating currents of 50 to 450 kA. Streak-camera photography was used to provide a qualitative description of plasma armature acceleration. The effects of plasma blowby and varying bore pressure on the behavior of plasma armatures were studied.

  16. Fatigue Crack Closure - A Review

    DTIC Science & Technology

    1990-09-01

    gauge along the crack line. They used CCT speci- mens of high tensile strength steel ( HY80 ). The measured value of U was found to be a minimum at the...ultrasonic surface wave technique on 12.5mm thick specimens of 2024-T851, 2024-T351, Al 2219, Ti-6AI-4V and 17-4 PH steel . Most of the results were...medium and high strength steels . Exami- nation of the fracture surfaces suggested that raising the mean stress in low fracture toughness steels could

  17. Design of rigid GRIN-endoscope with sapphire window and improved image quality

    NASA Astrophysics Data System (ADS)

    Fluder, Grzegorz; Voznesenskaya, Anna; Bakholdin, Alexey

    2015-05-01

    The possibilities of using gradient index (GRIN) lenses as the objective and relay lens in rigid endoscopic systems working in visible spectrum are investigated. The final aim of the project is to obtain a system providing diffraction limited image quality, which could be used for examining the gastrointestinal tract. This paper describes steps of the design of the system with working distance equal to 125 mm and angular field of view 25°. The diameter of the GRIN lenses is equal to 2,2 mm. Influence of the gradient of refractive index on the image quality is shown. Current results are analysed and future steps are described.

  18. Efficient second harmonic generation of a diode-laser-pumped CW Nd:YAG laser using monolithic MgO:LiNbO3 external resonant cavities

    NASA Technical Reports Server (NTRS)

    Kozlovsky, William J.; Nabors, C. D.; Byer, Robert L.

    1988-01-01

    56-percent efficient external-cavity-resonant second-harmonic generation of a diode-laser pumped, CW single-axial-mode Nd:YAG laser is reported. A theory of external doubling with a resonant fundamental is presented and compared to experimental results for three monolithic cavities of nonlinear MgO:LiNbO3. The best conversion efficiency was obtained with a 12.5-mm-long monolithic ring cavity doubler, which produced 29.7 mW of CW, single-axial model 532-nm radiation from an input of 52.5 mW.

  19. Focused beam control for ultrasound surgery with spherical-section phased array: sound field calculation and genetic optimization algorithm.

    PubMed

    Lu, Mingzhu; Wan, Mingxi; Xu, Feng; Wang, Xiaodong; Zhong, Hui

    2005-08-01

    This study aims at a sound field calculation for the spherical-section phased array and an optimization algorithm for the focus patterns of phased array ultrasound surgery. An efficient field calculation formula represented as an explicit expression is derived by the strategies of projection and binomial expansion. An optimization algorithm based on genetic algorithm is constructed by the suitable fitness function and the selection strategies. The simulation results of 256-element spherical-section phased array show the capability of controlling focus accurately and effectively with the combined method made up of the explicit expression method and the genetic optimization algorithm. The simulation results of single focus, multiple foci, on-axial focus, and off-axial focus further convince the feasibility of three-dimensional (3-D) focus steering with excellent acoustic performances. A single focus with the focus dimension of 1.25 mm x 1.25 mm x 7 mm and with the intensity of 6080 W/cm2 is formed. The multiple-focus pattern can enlarge the treatment volume 22 times larger than that of single focus with a sonication. In addition, a comparison between the explicit expression approach and the point source approach testifies to the applicability of the explicit expression approach. The experiment and simulation results of 16-element array actually confirm the feasibility of the combined method.

  20. Optimization of selective emitter fabrication method for solar cells using a laser grooving.

    PubMed

    Jung, W W; Kim, S C; Jung, S W; Moon, I Y; Kumar, K; Lee, Y W; Kim, S Y; Ju, M K; Han, S K; Yi, J

    2011-05-01

    In this paper, screen-printing laser grooved buried contact (LGBC) method was applied, which is compatible with the existing screen-printed solar cell equipment and facilities. Experiments were performed in order to optimize short circuit current (I(sc)), open circuit voltage (V(oc)) and fill factor of high efficiency solar cells. To enhance I(sc), V(oc) and efficiency, heavy doping was performed at low sheet resistance in the laser grooved region of the cell. In contrast, light doping was carried out at a high sheet resistance in the non-laser grooved region. To increase fill factor, porous silicon found on the wafer after dipping in an HF solution to remove SiN(x), was cleared. The fabricated screen-printing LGBC solar cell using a 125 mm x 125 mm single crystalline silicon wafer exhibited an efficiency of 17.2%. The results show that screen-printing LGBC method can be applied for high efficiency solar cells.

  1. Measuring lifting forces in rock climbing: effect of hold size and fingertip structure.

    PubMed

    Bourne, Roger; Halaki, Mark; Vanwanseele, Benedicte; Clarke, Jillian

    2011-02-01

    This study investigates the hypothesis that shallow edge lifting force in high-level rock climbers is more strongly related to fingertip soft tissue anatomy than to absolute strength or strength to body mass ratio. Fifteen experienced climbers performed repeated maximal single hand lifting exercises on rectangular sandstone edges of depth 2.8, 4.3, 5.8, 7.3, and 12.5 mm while standing on a force measurement platform. Fingertip soft tissue dimensions were assessed by ultrasound imaging. Shallow edge (2.8 and 4.3 mm) lifting force, in newtons or body mass normalized, was uncorrelated with deep edge (12.5 mm) lifting force (r < .1). There was a positive correlation (r = .65, p < .05) between lifting force in newtons at 2.8 mm edge depth and tip of bone to tip of finger pulp measurement (r < .37 at other edge depths). The results confirm the common perception that maximum lifting force on a deep edge ("strength") does not predict maximum force production on very shallow edges. It is suggested that increased fingertip pulp dimension or plasticity may enable increased deformation of the fingertip, increasing the skin to rock contact area on very shallow edges, and thus increase the limit of force production. The study also confirmed previous assumptions of left/right force symmetry in climbers.

  2. Separation and recovery of fine particles from waste circuit boards using an inflatable tapered diameter separation bed.

    PubMed

    Duan, Chenlong; Sheng, Cheng; Wu, Lingling; Zhao, Yuemin; He, Jinfeng; Zhou, Enhui

    2014-01-01

    Recovering particle materials from discarded printed circuit boards can enhance resource recycling and reduce environmental pollution. Efficiently physically separating and recovering fine metal particles (-0.5 mm) from the circuit boards are a key recycling challenge. To do this, a new type of separator, an inflatable tapered diameter separation bed, was developed to study particle motion and separation mechanisms in the bed's fluid flow field. For 0.5-0.25 mm circuit board particles, metal recovery rates ranged from 87.56 to 94.17%, and separation efficiencies ranged from 87.71 to 94.20%. For 0.25-0.125 mm particles, metal recovery rates ranged from 84.76 to 91.97%, and separation efficiencies ranged from 84.74 to 91.86%. For superfine products (-0.125 mm), metal recovery rates ranged from 73.11 to 83.04%, and separation efficiencies ranged from 73.00 to 83.14%. This research showed that the inflatable tapered diameter separation bed achieved efficient particle separation and can be used to recover fine particles under a wide range of operational conditions. The bed offers a new mechanical technology to recycle valuable materials from discarded printed circuit boards, reducing environmental pollution.

  3. SU-E-P-11: Comparison of Image Quality and Radiation Dose Between Different Scanner System in Routine Abdomen CT

    SciTech Connect

    Liao, S; Wang, Y; Weng, H

    2015-06-15

    Purpose To evaluate image quality and radiation dose of routine abdomen computed tomography exam with the automatic current modulation technique (ATCM) performed in two different brand 64-slice CT scanners in our site. Materials and Methods A retrospective review of routine abdomen CT exam performed with two scanners; scanner A and scanner B in our site. To calculate standard deviation of the portal hepatic level with a region of interest of 12.5 mm x 12.5mm represented to the image noise. The radiation dose was obtained from CT DICOM image information. Using Computed tomography dose index volume (CTDIv) to represented CT radiation dose. The patient data in this study were with normal weight (about 65–75 Kg). Results The standard deviation of Scanner A was smaller than scanner B, the scanner A might with better image quality than scanner B. On the other hand, the radiation dose of scanner A was higher than scanner B(about higher 50–60%) with ATCM. Both of them, the radiation dose was under diagnostic reference level. Conclusion The ATCM systems in modern CT scanners can contribute a significant reduction in radiation dose to the patient. But the reduction by ATCM systems from different CT scanner manufacturers has slightly variation. Whatever CT scanner we use, it is necessary to find the acceptable threshold of image quality with the minimum possible radiation exposure to the patient in agreement with the ALARA principle.

  4. Development of a pixelated CdTe detector module for a hard-x and gamma-ray imaging spectrometer application

    NASA Astrophysics Data System (ADS)

    Galvèz, J.-L.; Hernanz, M.; Álvarez, L.; Artigues, B.; Álvarez, J.-M.; Ullán, M.; Lozano, M.; Pellegrini, G.; Cabruja, E.; Martínez, R.; Chmeissani, M.; Puigdengoles, C.

    2016-07-01

    Stellar explosions are relevant and interesting astrophysical phenomena. Since long ago we have been working on the characterization of novae and supernovae in X and gamma-rays, with the use of space missions. We have also been involved in feasibility studies of future instruments in the energy range from several keV up to a few MeV, in collaboration with other research institutes. High sensitivities are essential to perform detailed studies of cosmic explosions and cosmic accelerators, e.g., Supernovae and Classical Novae. In order to fulfil the combined requirement of high detection efficiency with good spatial and energy resolution, an initial module prototype based on CdTe pixel detectors is being developed. The detector dimensions are 12.5mm x 12.5mm x 2mm with a pixel pitch of 1mm x 1mm. Two kinds of CdTe pixel detectors with different contacts have been tested: ohmic and Schottky. Each pixel is bump bonded to a fanout board made of Sapphire substrate and routed to the corresponding input channel of the readout VATAGP7.1 ASIC, to measure pixel position and pulse height for each incident gamma-ray photon. The study is complemented by the simulation of the CdTe module performance using the GEANT 4 and MEGALIB tools, which will help us to optimise the detector design. We will report on the spectroscopy characterisation of the CdTe detector module as well as the study of charge sharing.

  5. Physiological selectivity and activity reduction of insecticides by rainfall to predatory wasps of Tuta absoluta.

    PubMed

    Barros, Emerson C; Bacci, Leandro; Picanco, Marcelo C; Martins, Júlio C; Rosado, Jander F; Silva, Gerson A

    2015-01-01

    In this study, we carried out three bioassays with nine used insecticides in tomato crops to identify their efficiency against tomato leaf miner Tuta absoluta, the physiological selectivity and the activity reduction of insecticides by three rain regimes to predatory wasps Protonectarina sylveirae and Polybia scutellaris. We assessed the mortality caused by the recommended doses of abamectin, beta-cyfluthrin, cartap, chlorfenapyr, etofenprox, methamidophos, permethrin, phenthoate and spinosad to T. absoluta and wasps at the moment of application. In addition, we evaluated the wasp mortality due to the insecticides for 30 days on plants that did not receive rain and on plants that received 4 or 125 mm of rain. Spinosad, cartap, chlorfenapyr, phenthoate, abamectin and methamidophos caused mortality higher than 90% to T. absoluta, whereas the pyrethroids beta-cyfluthrin, etofenprox and permethrin caused mortality between 8.5% and 46.25%. At the moment of application, all the insecticides were highly toxic to the wasps, causing mortality higher than 80%. In the absence of rain, all the insecticides continued to cause high mortality to the wasps for 30 days after the application. The toxicity of spinosad and methamidophos on both wasp species; beta-cyfluthrin on P. sylveirae and chlorfenapyr and abamectin on P. scutellaris, decreased when the plants received 4 mm of rain. In contrast, the other insecticides only showed reduced toxicity on the wasps when the plants received 125 mm of rain.

  6. Twist knot cerclage wire: the appropriate wire tension for knot construction and fracture stability.

    PubMed

    Harnroongroj, Thossart

    1998-09-01

    OBJECTIVE: The aim was to find the best wire tension in order to permit a reliable first twist and simultaneously provide the best stability of fracture fixation from the twist knot cerclage wire. DESIGN: Wires at different distal tensions, looped around the fracture, were measured during twist and compared with the yield strength of the wire. Then, the fracture stability of the twist knot cerclage wire was determined from the pull-out strength. METHODS: In order to measure wire tension during twist knot construction, an instrument was designed using the tension load cell of a universal testing machine, a 15 degrees oblique osteotomy femoral shaft and 1.25 mm diameter wire. A wire tensioner and a pair of extraction grips were then used for measuring the pull-out strength of the cerclage wire fixation. RESULT: Three wire tensions (160, 200 and 240 N) were used as looped wire for the first twist knot construction. The 200 N tension cerclage wire provided the best fracture stability. CONCLUSION: It was found that 200 N was the best wire tension for the construction of a twist knot cerclage wire. RELEVANCE: When a cerclage wire is twisted at a femoral shaft using 1.25 mm diameter wire, a wire tension of 200 N should be used to achieve a reliable first twist and the best stability of fracture fixation.

  7. Variation of quantitative emphysema measurements from CT scans

    NASA Astrophysics Data System (ADS)

    Keller, Brad M.; Reeves, Anthony P.; Henschke, Claudia I.; Barr, R. Graham; Yankelevitz, David F.

    2008-03-01

    Emphysema is a lung disease characterized by destruction of the alveolar air sacs and is associated with long-term respiratory dysfunction. CT scans allow for imaging of the anatomical basis of emphysema, and several measures have been introduced for the quantification of the extent of disease. In this paper we compare these measures for repeatability over time. The measures of interest in this study are emphysema index, mean lung density, histogram percentile, and the fractal dimension. To allow for direct comparisons, the measures were normalized to a 0-100 scale. These measures have been computed for a set of 2,027 scan pairs in which the mean interval between scans was 1.15 years (σ: 93 days). These independent pairs were considered with respect to three different scanning conditions (a) 223 pairs where both were scanned with a 5 mm slice thickness protocol, (b) 695 with the first scanned with the 5 mm protocol and the second with a 1.25 mm protocol, and (c) 1109 pairs scanned both times using a 1.25 mm protocol. We found that average normalized emphysema index and histogram percentiles scores increased by 5.9 and 11 points respectively, while the fractal dimension showed stability with a mean difference of 1.2. We also found, a 7 point bias introduced for emphysema index under condition (b), and that the fractal dimension measure is least affected by scanner parameter changes.

  8. Thin Single Crystal Silicon Solar Cells on Ceramic Substrates: November 2009 - November 2010

    SciTech Connect

    Kumar, A.; Ravi, K. V.

    2011-06-01

    In this program we have been developing a technology for fabricating thin (< 50 micrometres) single crystal silicon wafers on foreign substrates. We reverse the conventional approach of depositing or forming silicon on foreign substrates by depositing or forming thick (200 to 400 micrometres) ceramic materials on high quality single crystal silicon films ~ 50 micrometres thick. Our key innovation is the fabrication of thin, refractory, and self-adhering 'handling layers or substrates' on thin epitaxial silicon films in-situ, from powder precursors obtained from low cost raw materials. This 'handling layer' has sufficient strength for device and module processing and fabrication. Successful production of full sized (125 mm X 125 mm) silicon on ceramic wafers with 50 micrometre thick single crystal silicon has been achieved and device process flow developed for solar cell fabrication. Impurity transfer from the ceramic to the silicon during the elevated temperature consolidation process has resulted in very low minority carrier lifetimes and resulting low cell efficiencies. Detailed analysis of minority carrier lifetime, metals analysis and device characterization have been done. A full sized solar cell efficiency of 8% has been demonstrated.

  9. Effects of dose reduction on the detectability of standardized radiolucent lesions in digital panoramic radiography.

    PubMed

    Dula, K; Sanderink, G; van der Stelt, P F; Mini, R; Buser, D

    1998-08-01

    Dose reduction in digital panoramic radiography was studied. Intentional underexposure was performed with the Orthophos DS while six different human mandibles were radiographed. Exposure settings were 69 kV/15 mA (standard), 64 kV/16 mA, and 60 kV/16 mA. Standardized spherical defects, each either 1 or 1.25 mm in diameter, were simulated in 288 of 432 images, and seven observers decided whether defects were present or not. Areas under the receiver operating characteristics curves were calculated. They showed no significant differences in the detectability of the 1-mm defect at 69, 64, or 60 kV. For the 1.25-mm defect, no difference was found between the 69 and 60 kV images, but a statistically significant different detectability was found for 64 kV images in comparison with both 69 and 60 kV images. A dose reduction of up to 43% was ascertained with a Pedo-RT-Humanoid phantom when panoramic radiography was performed at 60 kV/16 mA. The conclusion is that with the Orthophos DS, it seems possible to reduce the dose rate of x-rays without loss of diagnostic quality in the case of radiolucent changes.

  10. Fabrication of nano-sized magnetic tunnel junctions using lift-off process assisted by atomic force probe tip.

    PubMed

    Jung, Ku Youl; Min, Byoung-Chul; Ahn, Chiyui; Choi, Gyung-Min; Shin, Il-Jae; Park, Seung-Young; Rhie, Kungwon; Shin, Kyung-Ho

    2013-09-01

    We present a fabrication method for nano-scale magnetic tunnel junctions (MTJs), employing e-beam lithography and lift-off process assisted by the probe tip of atomic force microscope (AFM). It is challenging to fabricate nano-sized MTJs on small substrates because it is difficult to use chemical mechanical planarization (CMP) process. The AFM-assisted lift-off process enables us to fabricate nano-sized MTJs on small substrates (12.5 mm x 12.5 mm) without CMP process. The e-beam patterning has been done using bi-layer resist, the poly methyl methacrylate (PMMA)/ hydrogen silsesquioxane (HSQ). The PMMA/HSQ resist patterns are used for both the etch mask for ion milling and the self-aligned mask for top contact formation after passivation. The self-aligned mask buried inside a passivation oxide layer, is readily lifted-off by the force exerted by the probe tip. The nano-MTJs (160 nm x 90 nm) fabricated by this method show clear current-induced magnetization switching with a reasonable TMR and critical switching current density.

  11. Skeletal muscle injury induced by a pneumatic tourniquet: an enzyme- and immunohistochemical study in rabbits.

    PubMed

    Pedowitz, R A; Fridén, J; Thornell, L E

    1992-03-01

    The pathophysiology of skeletal muscle injury induced by compression beneath pneumatic tourniquets is poorly understood. Tourniquet hemostasis was induced in rabbit hindlimbs for 2 hr with a cuff inflation pressure of either 125 mm Hg (n = 5) or 350 mm Hg (n = 5). Skeletal muscle biopsies, taken 2 days later from tissue beneath and distal to the tourniquet, were frozen and analyzed using enzyme- and immunohistochemical techniques. In the 350 mm Hg tourniquet group, four of 10 thigh muscle samples demonstrated significant regional necrosis (mean 37.3% of the total cross-sectional area). Regional necrosis was not observed in thigh muscles of the 125 mm Hg tourniquet group or in any of the ischemic leg muscles. A topographic pattern of necrosis consistent with the arterial distribution of skeletal muscle suggested pathogenic events during the reperfusion period, such as granulocyte-mediated superoxide radical formation. Extremely large and rounded fibers (histochemically identified as Type IIB fibers) were observed in compressed thigh muscles, indicating differential fiber sensitivity to tourniquet compression and ischemia. The present study demonstrated significant skeletal muscle necrosis after a 2 hr tourniquet applied at a clinically relevant cuff inflation pressure. Recent studies of systemic changes associated with limb "ischemia" should be reassessed in consideration of the confounding effects of tissue compression induced beneath pneumatic tourniquets.

  12. Uncoupling of the baroreflex by N(N)-cholinergic blockade in dissecting the components of cardiovascular regulation

    NASA Technical Reports Server (NTRS)

    Shannon, J. R.; Jordan, J.; Black, B. K.; Costa, F.; Robertson, D.

    1998-01-01

    Systemic administration of adrenergic agonists and nitric oxide donors is used extensively to determine cardiovascular receptor sensitivity. Conclusions regarding receptor sensitivity in the presence of the baroreflex may be misleading. In 8 normal volunteers, we determined the heart rate and blood pressure changes after incremental bolus doses of isoproterenol, phenylephrine, and sodium nitroprusside before and during neuronal nicotinic cholinergic (N(N)-cholinergic) blockade with trimethaphan. Results are given as median (25th/75th percentile). With trimethaphan, the baroreflex slope (as determined by bolus doses of nitroprusside and phenylephrine) decreased from 24 (22/26) to 0.00 (0.00/0.09) ms/mm Hg (P<0.01). The dose of isoproterenol that decreased systolic blood pressure (SBP) 12.5 mm Hg changed from 0.61 (0.51/5.3) to 0.17 (0.12/0.21) microg (P<0.01); the dose required to increase heart rate 12.5 bpm changed from 0.22 (0.17/0.41) to 0.74 (0.33/2.3) microg (P<0.01). The dose of nitroprusside required to decrease SBP 12.5 mm Hg changed from 2.3 (1.3/3.4) to 0.18 (0.14/0.24) microg/kg (P<0.01). The dose of phenylephrine required to increase SBP 12.5 mm Hg changed from 135 (110/200) to 16 (10/30) microg (P<0.01). We conclude that the efferent arc of the baroreflex can be completely interrupted with N(N)-cholinergic blockade. Estimation of adrenoreceptor sensitivity and sensitivity to nitric oxide donors by systemic administration of agonists is severely confounded by baroreflexes. Uncoupling of the baroreflex by N(N)-cholinergic blockade may be a useful method to obtain an integrated measure of adrenergic receptor sensitivity and sensitivity to nitric oxide donors in humans. This approach would permit the comparison of normal and abnormal physiological states without the "noise" of baroreflex buffering.

  13. SU-C-210-04: Considerable Pancreatic Tumor Motion During Breath-Hold Measured Using Intratumoral Fiducials On Fluoroscopic Movies

    SciTech Connect

    Lens, E; Horst, A van der; Versteijne, E; Tienhoven, G van; Bel, A

    2015-06-15

    Purpose: Using a breath hold (BH) technique during radiotherapy of pancreatic tumors is expected to reduce intra-fractional motion. The aim of this study was to evaluate the tumor motion during BH. Methods: In this pilot study, we included 8 consecutive pancreatic cancer patients. All had 2– 4 intratumoral gold fiducials. Patients were asked to perform 3 consecutive 30-second end-inhale BHs on day 5, 10 and 15 of their three-week treatment. During BH, airflow through a mouthpiece was measured using a spirometer. Any inadvertent flow of air during BH was monitored for all patients. We measured tumor motion on lateral fluoroscopic movies (57 in total) made during BH. In each movie the fiducials as a group were tracked over time in superior-inferior (SI) and anterior-posterior (AP) direction using 2-D image correlation between consecutive frames. We determined for each patient the range of intra-BH motion over all movies; we also determined the absolute means and standard deviations (SDs) for the entire patient group. Additionally, we investigated the relation between inadvertent airflow during BH and the intra-BH motion. Results: We found intra-BH tumor motion of up to 12.5 mm (range, 1.0–12.5 mm) in SI direction and up to 8.0 mm (range, 1.0–8.0 mm) in AP direction. The absolute mean motion over the patient population was 4.7 (SD: 3.0) mm and 2.8 (SD: 1.2) mm in the SI and AP direction, respectively. Patients were able to perform stable consecutive BHs; during only 20% of the movies we found very small airflows (≤ 65 ml). These were mostly stepwise in nature and could not explain the continuous tumor motions we observed. Conclusion: We found substantial (up to 12.5 mm) pancreatic tumor motion during BHs. We found minimal inadvertent airflow, seen only during a minority of BHs, and this did not explain the obtained results. This work was supported by the foundation Bergh in het Zadel through the Dutch Cancer Society (KWF Kankerbestrijding) project No. UVA 2011-5271.

  14. How do kV and mAs affect CT lesion detection performance?

    NASA Astrophysics Data System (ADS)

    Huda, W.; Ogden, K. M.; Shah, K.; Jadoo, C.; Scalzetti, E. M.; Lavallee, R. L.; Roskopf, M. L.

    2007-03-01

    The purpose of this study was to investigate how output (mAs) and x-ray tube voltage (kV) affect lesion detection in CT imaging. An adult Rando phantom was scanned on a GE LightSpeed CT scanner at x-ray tube voltages from 80 to 140 kV, and outputs from 90 to 360 mAs. Axial images of the abdomen were reconstructed and viewed on a high quality monitor at a soft tissue display setting. We measured detection of 2.5 to 12.5 mm sized lesions using a 2 Alternate Forced Choice (2-AFC) experimental paradigm that determined lesion contrast (I) corresponding to a 92% accuracy (I 92%) of lesion detection. Plots of log(I 92%) versus log(lesion size) were all approximately linear. The slope of the contrast detail curve was ~ -1.0 at 90 mAs, close to the value predicted by the Rose model, but monotonically decreased with increasing mAs to a value of ~ -0.7 at 360 mAs. Increasing the x-ray tube output by a factor of four improved lesion detection by a factor of 1.9 for the smallest lesion (2.5 mm), close to the value predicted by the Rose model, but only by a factor of 1.2 for largest lesion (12.5 mm). Increasing the kV monotonically decreased the contrast detail slopes from -1.02 at 80 kV to -0.71 at 140 kV. Increasing the x-ray tube voltage from 80 to 140 kV improved lesion detection by a factor of 2.8 for the smallest lesion (2.5 mm), but only by a factor of 1.7 for largest lesion (12.5 mm). We conclude that: (i) quantum mottle is an important factor for low contrast lesion detection in images of anthropomorphic phantoms; (ii) x-ray tube voltage has a much greater influence on lesion detection performance than x-ray tube output; (iii) the Rose model only predicts CT lesion detection performance at low x-ray tube outputs (90 mAs) and for small lesions (2.5 mm).

  15. Effectiveness of dust control methods for crystalline silica and respirable suspended particulate matter exposure during manual concrete surface grinding.

    PubMed

    Akbar-Khanzadeh, Farhang; Milz, Sheryl A; Wagner, Cynthia D; Bisesi, Michael S; Ames, April L; Khuder, Sadik; Susi, Pam; Akbar-Khanzadeh, Mahboubeh

    2010-12-01

    Concrete grinding exposes workers to unacceptable levels of crystalline silica dust, known to cause diseases such as silicosis and possibly lung cancer. This study examined the influence of major factors of exposure and effectiveness of existing dust control methods by simulating field concrete grinding in an enclosed workplace laboratory. Air was monitored during 201 concrete grinding sessions while using a variety of grinders, accessories, and existing dust control methods, including general ventilation (GV), local exhaust ventilation (LEV), and wet grinding. Task-specific geometric mean (GM) of respirable crystalline silica dust concentrations (mg/m³ for LEV:HEPA-, LEV:Shop-vac-, wet-, and uncontrolled-grinding, while GV was off/on, were 0.17/0.09, 0.57/0.13, 1.11/0.44, and 23.1/6.80, respectively. Silica dust concentrations (mg/m³ using 100-125 mm (4-5 inch) and 180 mm (7 inch) grinding cups were 0.53/0.22 and 2.43/0.56, respectively. GM concentrations of silica dust were significantly lower for (1) GV on (66.0%) vs. off, and (2) LEV:HEPA- (99.0%), LEV:Shop-vac- (98.1%) or wet- (94.4%) vs. uncontrolled-grinding. Task-specific GM of respirable suspended particulate matter (RSP) concentrations (mg/m³ for LEV:HEPA-, LEV:Shop-vac-, wet-, and uncontrolled grinding, while GV was off/on, were 1.58/0.63, 7.20/1.15, 9.52/4.13, and 152/47.8, respectively. GM concentrations of RSP using 100-125 mm and 180 mm grinding cups were 4.78/1.62 and 22.2/5.06, respectively. GM concentrations of RSP were significantly lower for (1) GV on (70.2%) vs. off, and (2) LEV:HEPA- (98.9%), LEV:Shop-vac- (96.9%) or wet- (92.6%) vs. uncontrolled grinding. Silica dust and RSP were not significantly affected by (1) orientation of grinding surfaces (vertical vs. inclined); (2) water flow rates for wet grinding; (3) length of task-specific sampling time; or, (4) among cup sizes of 100, 115 or 125 mm. No combination of factors or control methods reduced an 8-hr exposure level to below the

  16. Response function measurements of an NE102A organic scintillator using an 241Am-Be source

    NASA Astrophysics Data System (ADS)

    Naqvi, A. A.; Aksoy, A.; Khiari, F. Z.; Coban, A.; Nagadi, M. M.; Al-Ohali, M. A.; Al-Jalal, M. A.

    1994-07-01

    The response function of a 125 mm diameter NE102A organic scintillation detector has been measured over the 2.7-14.8 MeV neutron energy range. The detector response function was derived from the light output for monoenergetic neutrons and gamma rays. The light output of the detector for monoenergetic neutrons was measured by selecting narrowgates in the time-of-flight (TOF) spectrum for a 241Am-Be neutron source. In order to provide check points on the data, the detector light output was also measured for monoenergetic neutrons from the D(d, n) and T(d, n) reactions. The response function of the NE102A detector is in good agreement (within 1-5%) with the published data of Cecil et al. [Nucl. Instr. and Meth. 161 (1979) 439].

  17. Track chambers based on precision drift tubes housed inside 30 mm mylar pipe

    NASA Astrophysics Data System (ADS)

    Borisov, A.; Bozhko, N.; Fakhrutdinov, R.; Kozhin, A.; Leontiev, B.; Levin, A.

    2014-06-01

    We describe drift chambers consisting of 3 layers of 30 mm (OD) drift tubes made of double sided aluminized mylar film with thickness 0.125 mm. A single drift tube is self-supported structure withstanding 350 g tension of 50 microns sense wire located in the tube center with 10 microns precision with respect to end-plug outer surface. Such tubes allow to create drift chambers with small amount of material, construction of such chambers doesn't require hard frames. Twenty six chambers with working area from 0.8 × 1.0 to 2.5 × 2.0 m2 including 4440 tubes have been manufactured for experiments at 70-GeV proton accelerator at IHEP(Protvino).

  18. Diet of double-crested cormorants wintering in Texas

    USGS Publications Warehouse

    Campo, J.J.; Thompson, B.C.; Barron, J.C.; Telfair II, R. C.; Durocher, P.; Gutreuter, S.

    1993-01-01

    The diets of 420 Double-crested Cormorants (Phalacrocorax auritus) were studied during November 1986-March 1987 on eight public reservoirs in Texas. Prey included 29 fish species and the mean live weight of fish per bird was 122 g. Fishes a??415 mm long were ingested, but those a??125 mm accounted for 90% of cormorant food contents by number. Shad (Dorosoma spp.) and sunfishes (Lepomis spp.) accounted for 90% of the total food items by number. Consumption of fishes (percent by weight) was different for male vs. female and adult vs. juvenile cormorants. Total consumption of fish by weight was consistent throughout the period; however, fewer but much larger fish were consumed after 15 February. Cormorants ate fishes that were most abundant in reservoirs. Sport fishes made up a substantial portion of cormorant food by weight, but not by number on some reservoirs. Cormorants ate very few large sport fish, however.

  19. Circulating bovine pregnancy associated glycoproteins are associated with late embryonic/fetal survival but not ovulatory follicle size in suckled beef cows.

    PubMed

    Pohler, K G; Geary, T W; Johnson, C L; Atkins, J A; Jinks, E M; Busch, D C; Green, J A; MacNeil, M D; Smith, M F

    2013-09-01

    The objective was to examine the relationship between ovulatory follicle size and embryo and fetal survival by using circulating concentrations of bovine pregnancy associated glycoproteins (bPAG) to detect the presence of an embryo or fetus and monitor placental function. Before examining the relationship between bPAG, ovulatory follicle size, and embryo and fetal survival, the half-life of bPAG was determined in Exp. 1. The half-life of bPAG after PGF2α-induced abortion on d 32 to 36 postinsemination was 35.8 ± 21.9 h (mean ± SD; range 7.1 to 78.5 h). In Exp. 2, suckled beef cows (n = 91) were treated with the CO-Synch protocol (GnRH on d -9, PGF2α on d -2, and GnRH and AI 48 h later [d 0]) and classified into 1 of 2 ovulatory follicle size groups: 1) small follicle (<12.5 mm; n = 25) or 2) large follicle (≥ 12.5 mm; n = 66). The first increase (P < 0.0001) in serum bPAG occurred in pregnant cows on d 24 after insemination and circulating bPAG decreased before a decrease in progesterone in 3 of 4 cows that lost an embryo or fetus. Pattern of secretion of bPAG in serum from d 24 to 60 after insemination (d 0) was affected by day (P < 0.0001), but not ovulatory follicle size. In Exp. 3, suckled beef cows (n = 1164) were administered the CO-Synch protocol either with (donor cows; n = 810) or without (recipient cows; n = 354) AI on d 0. Single embryos (n = 394) or oocytes (n = 45) were recovered from the donor cows [d 7; embryo transfer (ET)] and all live embryos were transferred into recipients the same day. Cows were classified on d 0 as having a small (<12.5 mm) or large (≥ 12.5 mm) ovulatory follicle, and randomly chosen as donors or recipients to remove confounding effects of ovulatory follicle size on fertility. Serum concentration of bPAG at d 28 was not affected by ovulatory follicle size (P = 0.85), embryo stage at ET (P = 0.75), embryo quality at ET (P = 0.64), estradiol at GnRH2 (P = 0.62) or serum progesterone at ET (d7; P = 0.14). Compared with cows that maintained pregnancy (n = 176), cows that exhibited late embryonic or fetal mortality (n = 19) after d 28 had decreased (P < 0.05) concentrations of bPAG on d 28. In summary, there was no relationship between serum bPAG and ovulatory follicle size or embryo stage or quality at ET; however, cows that lost an embryo after d 28 had reduced concentrations of bPAG on d 28 compared with cows that maintained pregnancy.

  20. Easy mounting interface for compact instruments at TNG

    NASA Astrophysics Data System (ADS)

    Ghedina, Adriano; Riverol Rodriguez, A. Luis

    2016-08-01

    The Telescopio Nazionale Galileo (TNG) is able to offer an F/11 Nasmyth focal station with an easy mount for small devices or compact instruments. The slit masks at the focal plane of the LRS spectrograph can be removed in few minutes from the selector stage. A FoV of 9x9arcmin2 is available and a small instrument can be mounted instead of the slit on a mechanical interface of 240x125mm. The size of the instrument along the optical axis is limited by the support of the collimation lens of the spectrograph. This solution has already been used for small devices like a CCD camera or a SH sensor and a compact Hamamatsu photometer. Furthermore from 2016 it will host the folding optical relay for the GIARPS Instrument. This interface is an opportunity to test new instruments, prototypes or demonstrators in a not invasive or time consuming manner at a 4m class telescope.

  1. Characterization of MgB2 Conductors for Coil Development

    NASA Astrophysics Data System (ADS)

    Aslanoglu, Z.; Arda, L.; Akin, Y.; Sumption, M. D.; Tomsic, M.; Hascicek, Y. S.

    2004-06-01

    The effects of the heat treatment conditions on microstructure and the transport critical current density of MgB2 wires, which were fabricated by the Continuous Tube Forming and Filling (CTFF) process, have been investigated. Two types of MgB2 conductors, Fe/MgB2 and Cu/MgB2, were studied. It was found that the sheath materials affect the optimum annealing profile of MgB2 conductor. The annealing temperature for Cu/MgB2 conductors was lower than that for the Fe/MgB2 conductors. The critical current density, Jc was measured to be 1.1×105 A/cm2 at 20 K in-self field for Cu/MgB2 conductor of 1.25 mm in diameter. The processing, microstructure and superconducting properties are presented.

  2. Photoacoustic imaging of carotid artery atherosclerosis

    NASA Astrophysics Data System (ADS)

    Kruizinga, Pieter; van der Steen, Antonius F. W.; de Jong, Nico; Springeling, Geert; Robertus, Jan Lukas; van der Lugt, Aad; van Soest, Gijs

    2014-11-01

    We introduce a method for photoacoustic imaging of the carotid artery, tailored toward detection of lipid-rich atherosclerotic lesions. A common human carotid artery was obtained at autopsy, embedded in a neck mimicking phantom and imaged with a multimodality imaging system using interstitial illumination. Light was delivered through a 1.25-mm-diameter optical probe that can be placed in the pharynx, allowing the carotid artery to be illuminated from within the body. Ultrasound imaging and photoacoustic signal detection is achieved by an external 8-MHz linear array coupled to an ultrasound imaging system. Spectroscopic analysis of photoacoustic images obtained in the wavelength range from 1130 to 1250 nm revealed plaque-specific lipid accumulation in the collagen structure of the artery wall. These spectroscopic findings were confirmed by histology.

  3. Characterization of transparent conductive oxide films and their effect on amorphous/crystalline silicon heterojunction solar cells

    NASA Astrophysics Data System (ADS)

    Meng, Fanying; Shi, Jianhua; Shen, Leilei; Zhang, Liping; Liu, Jinning; Liu, Yucheng; Yu, Jian; Bao, Jian; Liu, Zhengxin

    2017-04-01

    Three different dopant indium oxide thin films were fabricated at low temperatures by reactive plasma deposition and sputtering. The optical and electrical characteristics of these films were analyzed as a function of the Hall electron concentration. Furthermore, these films were applied to amorphous/crystalline silicon heterojunction solar cells as transparent electrodes. Consequently, it was demonstrated that the high Hall mobility, high refractive index, and low extinction coefficient of transparent conductive oxide (TCO) films contribute to the high product of short-circuit current density and fill factor and conversion efficiency. Furthermore, it was found that the solar cell with a finger spacing of 1.9 mm on a 125 × 125 mm2 Si wafer is highly tolerant to TCO film resistivity when the electron concentration is less than 4.0 × 1020 cm‑3.

  4. Two new species of Choerophryne (Anura, Microhylidae) from the northern versant of Papua New Guinea's central cordillera.

    PubMed

    Iannella, Amy; Oliver, Paul; Richards, Stephen

    2015-12-17

    We describe two new species of small microhylid frogs in the genus Choerophryne from the northern slopes of Papua New Guinea's central cordillera. Choerophryne epirrhina sp. nov. can be distinguished from congeners by the combination of moderately small size (SUL 14.9-15.0 mm), distinctly elongated snout (OHG/SUL 0.09-0.10), first finger without expanded disk, and advertisement call consisting of 3-4 distinctly pulsed notes repeated in long sequences. Choerophryne grylloides sp. nov. can be distinguished from congeners by the combination of very small size (SUL 12.5 mm), moderately long snout (OHG/SUL 0.08), long legs (TL/SUL 0.42), first finger without expanded disk and advertisement call consisting of 4-5 distinctly pulsed notes, the last of which has many more pulses than preceding notes (9-10 vs. 3-4).

  5. Pressurized subsampling system for pressured gas-hydrate-bearing sediment: microscale imaging using X-ray computed tomography.

    PubMed

    Jin, Yusuke; Konno, Yoshihiro; Nagao, Jiro

    2014-09-01

    A pressurized subsampling system was developed for pressured gas hydrate (GH)-bearing sediments, which have been stored under pressure. The system subsamples small amounts of GH sediments from cores (approximately 50 mm in diameter and 300 mm in height) without pressure release to atmospheric conditions. The maximum size of the subsamples is 12.5 mm in diameter and 20 mm in height. Moreover, our system transfers the subsample into a pressure vessel, and seals the pressure vessel by screwing in a plug under hydraulic pressure conditions. In this study, we demonstrated pressurized subsampling from artificial xenon-hydrate sediments and nondestructive microscale imaging of the subsample, using a microfocus X-ray computed tomography (CT) system. In addition, we estimated porosity and hydrate saturation from two-dimensional X-ray CT images of the subsamples.

  6. Neurosurgical applications of ocular pneumoplethysmography.

    PubMed

    Bingham, W F

    1981-05-01

    Ocular pneumoplethysmography (OPG), a semiautomated form of suction ophthalmodynamometry, was used to evaluate and follow 15 patients who underwent carotid endarterectomy and two patients in whom gradual carotid artery occlusion was performed for inoperable intracranial aneurysm. Postoperative corrected ophthalmic arterial pressures (COAP's) on the operated side in the carotid endarterectomy patients averaged 12.5 mm Hg higher than before surgery, the standard deviation being 4.9 mm Hg for clinically stable patients. There was no significant change in COAP on the contralateral side. Several problems were encountered in closing down carotid clamps, the most potentially serious being a precipitous fall in COAP with the final adjustment. The current uses of OPG and similar techniques are reviewed, and potential neurosurgical applications are discussed.

  7. Experimental Acquisitions with ^125I on a Small Animal SPECT Device*

    NASA Astrophysics Data System (ADS)

    Knott, Kevin; Welsh, Robert E.; Bradley, Eric L.; Saha, Margaret S.; Kross, Brian; Majewski, Stan; Popov, Vladimir; Smith, Mark F.; Weisenberger, Andrew G.; Wojcik, Randolph

    2001-04-01

    We have performed single photon emission computed tomography (SPECT) studies on a small animal scanning system for which the detector employed position sensitive phototubes (125 mm dia. Hamamatsu R3292 and 18 x 18 mm Hamamatsu M-64) coupled to pixelated scintillators CsI(Tl) and CsI(Na) Phantom acquisitions were used to investigate the effects of angular sampling and scan time on reconstructed image quality and noise. Results from these studies will be described and extended to in vivo studies with small animals. *Supported in part by the Thomas F. and Kate Miller Jeffress Trust, the Department of Energy, The American Diabetes Association, The National Science Foundation, the Howard Hughes Foundation and the Virginia Commonwealth Health Research Board.

  8. PIT Tagging Anurans

    USGS Publications Warehouse

    McCreary, Brome

    2008-01-01

    The following video demonstrates a procedure to insert a passive integrated transponder (PIT) tag under the skin of an anuran (frog or toad) for research and monitoring purposes. Typically, a 12.5 mm tag (0.5 in.) is used to uniquely identify individual anurans as smal as 40 mm (1.6 in.) in length from snout to vent. Smaller tags are also available and allow smaller anurans to be tagged. The procedure does not differ for other sizes of tages or other sizes of anurans. Anyone using this procedure should ensure that the tag is small enough to fit easily behind the sacral hump of the anuran, as shown in this video.

  9. NIKEL_AMC: readout electronics for the NIKA2 experiment

    NASA Astrophysics Data System (ADS)

    Bourrion, O.; Benoit, A.; Bouly, J. L.; Bouvier, J.; Bosson, G.; Calvo, M.; Catalano, A.; Goupy, J.; Li, C.; Macías-Pérez, J. F.; Monfardini, A.; Tourres, D.; Ponchant, N.; Vescovi, C.

    2016-11-01

    The New Iram Kid Arrays-2 (NIKA2) instrument has recently been installed at the IRAM 30 m telescope. NIKA2 is a state-of-art instrument dedicated to mm-wave astronomy using microwave kinetic inductance detectors (KID) as sensors. The three arrays installed in the camera, two at 1.25 mm and one at 2.05 mm, feature a total of 3300 KIDs. To instrument these large array of detectors, a specifically designed electronics, composed of 20 readout boards and hosted in three microTCA crates, has been developed. The implemented solution and the achieved performances are presented in this paper. We find that multiplexing factors of up to 400 detectors per board can be achieved with homogeneous performance across boards in real observing conditions, and a factor of more than 3 decrease in volume with respect to previous generations.

  10. An evaluation of the shielding effectiveness of lead aprons used in clinics for protection against ionising radiation from novel radioisotopes.

    PubMed

    Deb, Pradip; Jamison, Robert; Mong, Lisa; U, Paul

    2015-07-01

    The purpose of this study is to evaluate the effectiveness of personal radiation shields currently worn in hospital and other diagnostic environments. This study was performed with four different radioisotopes; (18)F, (99m)Tc, (124)I and (131)I. (18)F results showed a decrease in dose with 0.5-mm Pb shielding but the reduction provided does not warrant its use clinically. (124)I testing demonstrated that dose enhancement can occur in greater shield thicknesses. PET isotope (124)I can be adequately shielded using 0.25-mm Pb equivalent aprons but any higher thickness increase the wearer's dose. As a result more shielding does not always equal more protection. The (131)I test showed that no dose reduction occurred, even when tested with up to 1.25-mm Pb equivalent shielding. Novel radioisotopes being used in the laboratory and clinic should be individually tested as each requires specific shielding testing.

  11. [POSSIBILITIES OF VACUUM THERAPY APPLICATION IN DISORDERS OF VENOUS OUTFLOW IN ISLET GRAFTS].

    PubMed

    Badyul, P O; Samoylenko, G E; Nor, N M; Slesarenko, K S

    2015-07-01

    The experience of "distressed" (problematic) flaps application in 33 patients with soft tissue defects over 2010-2014 years were analysed. It was proposed to use the local negative pressure for the prevention and treatment of complications associated with venous insufficiency or trombosis in using of plastics with vascularised complexes of tissues. Vacuum-therapy was conducted with the help of negative pressure apparatus "AGATE-Dnepr" (Ukraine) by attaching silver-containing polyurethane sponge on the operating zone, covering the flap with the surrounding skin netting band "Grassolind". The recommended standard of negative pressure of 75-125 mm Hg, both in impulse and in continuous mode was used. The high efficiency of vacuum-therapy for survival of grafts has been demonstrated. Thus, it might be considered as an effective element of prevention and treatment of complications associated with venous insufficiency or trombosis using of vascularised tissue complex plastics of defects.

  12. High-Speed Laser Scanner Maps a Surface in Three Dimensions

    NASA Technical Reports Server (NTRS)

    Lavelle, Joseph; Schuet, Stefan

    2006-01-01

    A scanning optoelectronic instrument generates the digital equivalent of a threedimensional (X,Y,Z) map of a surface that spans an area with resolution on the order of 0.005 in. ( 0.125mm). Originally intended for characterizing surface flaws (e.g., pits) on space-shuttle thermal-insulation tiles, the instrument could just as well be used for similar purposes in other settings in which there are requirements to inspect the surfaces of many objects. While many commercial instruments can perform this surface-inspection function, the present instrument offers a unique combination of capabilities not available in commercial instruments. This instrument utilizes a laser triangulation method that has been described previously in NASA Tech Briefs in connection with simpler related instruments used for different purposes. The instrument includes a sensor head comprising a monochrome electronic camera and two lasers. The camera is a high-resolution

  13. Rail accelerator technology and applications

    NASA Technical Reports Server (NTRS)

    Zana, L. M.; Kerslake, W. R.

    1985-01-01

    Rail accelerators offer a viable means of launching ton-size payloads from the Earth's surface to space. The results of two mission studies which indicate that an Earth-to-Space Rail Launcher (ESRL) system is not only technically feasible but also economically beneficial, particularly when large amounts of bulk cago are to be delivered to space are given. An in-house experimental program at the Lewis Research Center (LeRC) was conducted in parallel with the mission studies with the objective of examining technical feasibility issues. A 1 m long - 12.5 by 12.5 mm bore rail accelerator as designed with clear polycarbonate sidewalls to visually observe the plasma armature acceleration. The general character of plasma/projectile dynamics is described for a typical test firing.

  14. Intraluminal and intracavitary vacuum therapy for esophageal leakage: a new endoscopic minimally invasive approach.

    PubMed

    Loske, G; Schorsch, T; Müller, C

    2011-06-01

    Endoscopic treatment by placement of a vacuum sponge drainage system is a new option in the management of leakages in the digestive tract. We now distinguish between two treatment variants: the intracavitary and intraluminal techniques. A drainage system comprising an appropriately trimmed polyurethane foam sponge and a gastric-type tube is either placed through the esophageal defect into an extraluminal wound cavity (intracavitary method), or directly onto the defect with the sponge remaining within the esophageal lumen (intraluminal method). Continuous negative pressure of 125 mmHg is then applied, resulting in stabilizing of the sponge and continuous drainage and sealing of the defect. We report a case series of 14 patients, presenting the full range of possible esophageal defects that were successfully treated with either intracavitary or intraluminal vacuum therapy. Complete healing of the esophageal defect was achieved in 13 patients; one patient died due to fulminant pseudomembranous colitis while the esophageal defect was nearly healed.

  15. Experimental investigation on heat transfer analysis of conical coil heat exchanger with 90° cone angle

    NASA Astrophysics Data System (ADS)

    Purandare, Pramod S.; Lele, Mandar M.; Gupta, Raj Kumar

    2015-03-01

    In the present study, an experimental investigation on thermal performance of the conical coil heat exchanger with 90° conical coil heat exchanger is reported. Three different conical coil heat exchangers of same mean coil diameter (Dm = 200 mm) with different tube diameters ( di = 8, 10, 12.5 mm) are analyzed under steady state condition. The analysis is carried out for the tube side hot fluid flow range of 10-100 lph ( Re = 500-5,000), while the shell side flow range of 30-90 lph. The data available from experimentation leads to evaluate heat transfer coefficients for inside and outside the tube of the conical coil heat exchanger by Wilsons plot method. The calculations are further extended to estimate Nusselt Number ( Nu) and effectiveness. The empirical correlations are proposed for predicting Nu and the outlet temperatures of hot and cold fluids. The predicted empirical correlations show reasonable agreement with the experimental results within the given range of parameters.

  16. Multireflection pumping concept for miniaturized diode-pumped solid-state lasers.

    PubMed

    Meister, Jörg; Franzen, Rene; Apel, Christian; Gutknecht, Norbert

    2004-11-01

    An innovative pump concept for diode-pumped, solid-state lasers is introduced as an example for an Er:YSGG laser, permitting its miniaturization. Embedded in a multireflective pump cavity, the laser crystal is simultaneously side and end pumped. Specially calculated and shaped deflecting optics distribute the coaxially input pumping light homogeneously over the lateral surface of the crystal, therefore reducing the size of the laser head, including the optical resonator, to a length of 27.5 mm and an outside diameter of 12.5 mm. The differential efficiency achieved is between 8.7% and 24%. The laser emits energy of 15.7 mJ at an absolute efficiency of 9.1% and a repetition rate of 4 Hz.

  17. Pressurized subsampling system for pressured gas-hydrate-bearing sediment: Microscale imaging using X-ray computed tomography

    SciTech Connect

    Jin, Yusuke Konno, Yoshihiro; Nagao, Jiro

    2014-09-01

    A pressurized subsampling system was developed for pressured gas hydrate (GH)-bearing sediments, which have been stored under pressure. The system subsamples small amounts of GH sediments from cores (approximately 50 mm in diameter and 300 mm in height) without pressure release to atmospheric conditions. The maximum size of the subsamples is 12.5 mm in diameter and 20 mm in height. Moreover, our system transfers the subsample into a pressure vessel, and seals the pressure vessel by screwing in a plug under hydraulic pressure conditions. In this study, we demonstrated pressurized subsampling from artificial xenon-hydrate sediments and nondestructive microscale imaging of the subsample, using a microfocus X-ray computed tomography (CT) system. In addition, we estimated porosity and hydrate saturation from two-dimensional X-ray CT images of the subsamples.

  18. Epikeratoplasty for keratoglobus associated with blue sclera.

    PubMed

    Cameron, J A; Cotter, J B; Risco, J M; Alvarez, H

    1991-04-01

    Patients with keratoglobus and blue sclera as part of a generalized connective tissue disorder are at a high risk of developing corneal perforations either spontaneously or after mild trauma. Six patients (6 eyes) between the ages of 2 and 16 years of age (mean, 7.5 years) with keratoglobus, blue sclera, hypermobile joints, and consanguineous parents were treated by epikeratoplasty, using commercially prepared 12.5-mm lenticules. Surgery was performed for tectonic support and/or visual improvement and was successful in five of six patients with a follow-up period of 11 to 27 months (mean, 21 months). One lenticule was removed because the epithelium did not heal. Peripheral interface opacities occurred in three patients.

  19. A new type of medical micropump for an endoscopic robot.

    PubMed

    Ye, Dongdong; Yan, Guozheng; Zan, Peng; Wang, Kundong

    2010-01-01

    Researchers have developed a new type of medical micropump for an endoscopic robot, which is driven by a linear actuator based on a direct current (DC) motor. This micropump consists of two active one-way valves and a cylindrical air drum. The overall size of the pump prototype is 12.5 mm in diameter and 56 mm in length. This paper describes the structure of the micropump and linear actuator and analyzes the inflation mechanism of the micropump. The experimental results show that the driving force of the linear actuator can reach up to 2.55 N, which fulfills the need of the micropump. The rated output flow of the micropump is 16 mL/min, which can rapidly supply the gas bag with enough air with minimal noise and vibration.

  20. Distributed Non-evaporable Getter pumps for the storage ring of the APS

    SciTech Connect

    Dortwegt, R.; Benaroya, R.

    1993-07-01

    A pair of distributed Non-evaporable Getter (NeG) strip assemblies is installed in each of 236 aluminum vacuum chambers of the 1104-m storage ring of the Advanced Photon Source. Distributed pumping is provided to remove most of the gas resulting from photon-stimulated desorption occurring along the outer walls of the chambers. This is an efficient way of pumping because conductance is limited along the beam axis. The St-707 NeG strips are conditioned at 450{degree}C for 45 min. with 42 A. Base pressures obtained are also as low as 4 {times} 10{sup 11} Torr. The NeG strip assemblies are supported by a series of electrically isolated, 125-mm-long, interlocking stainless steel carriers. These unique interlocking carrier elements provide flexibility along the vacuum chamber curvature (r=38.96 m) and permit removal and installation of assemblies with as little as 150 mm external clearance between adjacent chambers.

  1. Bend-insensitive distributed sensing in singlemode-multimode-singlemode optical fiber structure by using Brillouin optical time-domain analysis

    NASA Astrophysics Data System (ADS)

    Xu, Pengbai; Zhang, Hongying; Lu, Zhiwei; Chen, Liang; Bao, Xiaoyi; Dong, Yongkang

    2015-09-01

    We propose a bend-insensitive distributed Brillouin optical fiber sensing by using a singlemode-multimode-singlemode optical fiber structure for the first time to the best of our knowledge. The sensing fiber is a graded-index multimode fiber (GI-MMF) sandwiched by two standard single-mode fibers (SMFs) with centrally alignment splicing at the interface between GI-MMF and SMF to excite the fundamental mode only in GI-MMF. The sensing system can resist a minimal bend radius of 1.25mm while maintaining the measurement performance, with which the measured coefficient of strain is 421.6MHz/%. We also demonstrate that the higher-order modes exciting in GI-MMF can be easily influenced by bending, so that the fundamental mode exciting is essential for bend-insensitive distributed sensing.

  2. Recovery Act: Novel Kerf-Free PV Wafering that provides a low-cost approach to generate wafers from 150um to 50um in thickness

    SciTech Connect

    Fong, Theodore E.

    2013-05-06

    The technical paper summarizes the project work conducted in the development of Kerf-Free silicon wafering equipment for silicon solar wafering. This new PolyMax technology uses a two step process of implantation and cleaving to exfoliate 50um to 120um wafers with thicknesses ranging from 50um to 120um from a 125mm or 156mm pseudo-squared silicon ingot. No kerf is generated using this method of wafering. This method of wafering contrasts with the current method of making silicon solar wafers using the industry standard wire saw equipment. The report summarizes the activity conducted by Silicon Genesis Corporation in working to develop this technology further and to define the roadmap specifications for the first commercial proto-type equipment for high volume solar wafer manufacturing using the PolyMax technology.

  3. Development and validation of stability-indicating HPLC method for determination of cefpirome sulfate.

    PubMed

    Zalewski, Przemysław; Skibiński, Robert; Cielecka-Piontek, Judyta; Bednarek-Rajewska, Katarzyna

    2014-01-01

    The stability-indicating LC assay method was developed and validated for quantitative determination of cefpirome sulfate (CPS) in the presence of degradation products formed during the forced degradation studies. An isocratic HPLC method was developed with Lichrospher RP-18 column, 5 μm particle size, 125 mm x 4 mm column and 12 mM ammonium acetate-acetonitrile (90 : 10 v/v) as a mobile phase. The flow rate of the mobile phase was 1.0 mL/min. Detection wavelength was 270 nm and temperature was 30 degrees C. Cefpirome sulfate as other cephalosporins was subjected to stress conditions of degradation in aqueous solutions including hydrolysis, oxidation, photolysis and thermal degradation. The developed method was validated with regard to linearity, accuracy, precision, selectivity and robustness. The method was applied successfully for identification and determination of cefpirome sulfate in pharmaceuticals and during kinetic studies.

  4. A new 3D texture feature based computer-aided diagnosis approach to differentiate pulmonary nodules

    NASA Astrophysics Data System (ADS)

    Han, Fangfang; Wang, Huafeng; Song, Bowen; Zhang, Guopeng; Lu, Hongbing; Moore, William; Zhao, Hong; Liang, Zhengrong

    2013-02-01

    To distinguish malignant pulmonary nodules from benign ones is of much importance in computer-aided diagnosis of lung diseases. Compared to many previous methods which are based on shape or growth assessing of nodules, this proposed three-dimensional (3D) texture feature based approach extracted fifty kinds of 3D textural features from gray level, gradient and curvature co-occurrence matrix, and more derivatives of the volume data of the nodules. To evaluate the presented approach, the Lung Image Database Consortium public database was downloaded. Each case of the database contains an annotation file, which indicates the diagnosis results from up to four radiologists. In order to relieve partial-volume effect, interpolation process was carried out to those volume data with image slice thickness more than 1mm, and thus we had categorized the downloaded datasets to five groups to validate the proposed approach, one group of thickness less than 1mm, two types of thickness range from 1mm to 1.25mm and greater than 1.25mm (each type contains two groups, one with interpolation and the other without). Since support vector machine is based on statistical learning theory and aims to learn for predicting future data, so it was chosen as the classifier to perform the differentiation task. The measure on the performance was based on the area under the curve (AUC) of Receiver Operating Characteristics. From 284 nodules (122 malignant and 162 benign ones), the validation experiments reported a mean of 0.9051 and standard deviation of 0.0397 for the AUC value on average over 100 randomizations.

  5. Using Mid-Upper Arm Circumference to End Treatment of Severe Acute Malnutrition Leads to Higher Weight Gains in the Most Malnourished Children

    PubMed Central

    Dale, Nancy M.; Myatt, Mark; Prudhon, Claudine; Briend, André

    2013-01-01

    Objective The World Health Organization recommends discharging children admitted to nutrition programs treating severe acute malnutrition, with a low mid-upper arm circumference (MUAC <115 mm) when weight gain is >15%. When this recommendation is followed, the most severely malnourished children receive a shorter treatment compared to children that are less severely malnourished. This study assesses whether using MUAC >125 mm as discharge criteria eliminates this effect. Methods and Findings Data from 753 children cured from a Médecins Sans Frontières outpatient nutrition program in Gedaref, North Sudan were analyzed. MUAC >125 mm was used as discharge criteria. Length of stay and percent weight gain of children were compared in relation to nutritional status on admission. Children with low MUAC on admission had a longer duration of treatment (p = 0.000) and also a higher percent weight gain (p = 0.000) than children with higher MUAC. Similar results with weight-for-height z-scores categories were shown with both duration of treatment (p = 0.000) and percent weight gain (p = 0.000). Conclusion This study shows that using MUAC as the discharge criteria eliminates the effect of shorter treatment in most severely malnourished children compared to least severely malnourished, as is observed with percent weight gain. The findings directly address the main concern that has been identified with the current WHO recommendation of using percent weight gain. MUAC could be used as discharge criteria, instead of percent weight gain, as having a longer duration of treatment and a higher percent weight gain for the most malnourished is highly desirable. PMID:23418442

  6. SU-E-T-637: Proton Aperture Quality Assurance Using Computed Tomography

    SciTech Connect

    Reyhan, M; Yue, N; Zou, J

    2015-06-15

    Purpose: To develop an automated algorithm for aperture quality assurance for double scattering proton radiotherapy. Methods: Anterior-Posterior scout images were acquired on a CT scanner for five brass apertures (2 large, 3 small) with 120 kVp and 10mA. A semi-automated algorithm was developed for the QA process. The input includes a user selecting the scout image and the associated patient plan, field and aperture size. The program automatically thresholds the scout image. Next, a connectivity algorithm is used to determine the points associated with the central shape to obtain the contour. To compare with the plan contour, the program converts the detected and plan contours into polar coordinates, interpolates the data to a 1 degree spaced grid, and determines the differences in radial distance at each grid point. Results: The mean and maximum difference and the percentage of points with distance differences less than 1.25 mm (due to the divergent cut of the aperture) between the detected and plan field aperture contours were obtained. A repeatability coefficient was derived based on repeated scanning and processing of three of the apertures. The mean difference for five apertures was 0.44 +/−0.08 mm. The maximum difference in distance was 1.2 +/−0.23 mm for all apertures. The Repeatability Coefficient was +/−0.038 mm, indicating the technique is highly repeatable. The mean percent of points with distance less than 1.25 mm was 97.41 +/−0.35%. Conclusion: Automated CT scout image based proton aperture QA is feasible, saves time, and provides a quantitative metric for proton patient specific aperture QA.

  7. SU-E-T-391: Evaluation of Image Parameters Impact On the CT Calibration Curve for Proton Therapy

    SciTech Connect

    Xiao, Z; Reyhan, M; Huang, Q; Zhang, M; Yue, N; Chen, T

    2015-06-15

    Purpose: The calibration of the Hounsfield units (HU) to relative proton stopping powers (RSP) is a crucial component in assuring the accurate delivery of proton therapy dose distributions to patients. The purpose of this work is to assess the uncertainty of CT calibration considering the impact of CT slice thickness, position of the plug within the phantom and phantom sizes. Methods: Stoichiometric calibration method was employed to develop the CT calibration curve. Gammex 467 tissue characterization phantom was scanned in Tomotherapy Cheese phantom and Gammex 451 phantom by using a GE CT scanner. Each plug was individually inserted into the same position of inner and outer ring of phantoms at each time, respectively. 1.25 mm and 2.5 mm slice thickness were used. Other parameters were same. Results: HU of selected human tissues were calculated based on fitted coefficient (Kph, Kcoh and KKN), and RSP were calculated according to the Bethe-Bloch equation. The calibration curve was obtained by fitting cheese phantom data with 1.25 mm thickness. There is no significant difference if the slice thickness, phantom size, position of plug changed in soft tissue. For boney structure, RSP increases up to 1% if the phantom size and the position of plug changed but keep the slice thickness the same. However, if the slice thickness varied from the one in the calibration curve, 0.5%–3% deviation would be expected depending on the plug position. The Inner position shows the obvious deviation (averagely about 2.5%). Conclusion: RSP shows a clinical insignificant deviation in soft tissue region. Special attention may be required when using a different slice thickness from the calibration curve for boney structure. It is clinically practical to address 3% deviation due to different thickness in the definition of clinical margins.

  8. Pixel CdTe semiconductor module to implement a sub-MeV imaging detector for astrophysics

    NASA Astrophysics Data System (ADS)

    Gálvez, J.-L.; Hernanz, M.; Álvarez, L.; Artigues, B.; Álvarez, J.-M.; Ullán, M.; Pellegrini, G.; Lozano, M.; Cabruja, E.; Martínez, R.; Chmeissani, M.; Puigdengoles, C.

    2017-03-01

    Stellar explosions are relevant and interesting astrophysical phenomena. Since long ago we have been working on the characterization of nova and supernova explosions in X and gamma rays, with the use of space missions such as INTEGRAL, XMM-Newton and Swift. We have been also involved in feasibility studies of future instruments in the energy range from several keV up to a few MeV, in collaboration with other research institutes, such as GRI, DUAL and e-ASTROGAM. High sensitivities are essential to perform detailed studies of cosmic explosions and cosmic accelerators, e.g., Supernovae, Classical Novae, Supernova Remnants (SNRs), Gamma-Ray Bursts (GRBs). In order to fulfil the combined requirement of high detection efficiency with good spatial and energy resolution, an initial module prototype based on CdTe pixel detectors is being developed. The detector dimensions are 12.5mm x 12.5mm x 2mm, with a pixel pitch of 1mm x 1mm. Each pixel is bump bonded to a fanout board made of Sapphire substrate and routed to the corresponding input channel of the readout ASIC, to measure pixel position and pulse height for each incident gamma-ray photon. An ohmic CdTe pixel detector has been characterised by means of 57Co, 133Ba and 22Na sources. Based on this, its spectroscopic performance and the influence of charge sharing is reported here. The pixel study is complemented by the simulation of the CdTe module performance using the GEANT 4 and MEGALIB tools, which will help us to optimise the pixel size selection.

  9. Landfill mining: Case study of a successful metals recovery project.

    PubMed

    Wagner, Travis P; Raymond, Tom

    2015-11-01

    Worldwide, the generation of municipal solid waste (MSW) is increasing and landfills continue to be the dominant method for managing solid waste. Because of inadequate diversion of reusable and recoverable materials, MSW landfills continue to receive significant quantities of recyclable materials, especially metals. The economic value of landfilled metals is significant, fostering interest worldwide in recovering the landfilled metals through mining. However, economically viable landfill mining for metals has been elusive due to multiple barriers including technological challenges and high costs of processing waste. The objective of this article is to present a case study of an economically successful landfill mining operation specifically to recover metals. The mining operation was at an ashfill, which serves a MSW waste-to-energy facility. Landfill mining operations began in November 2011. Between December 2011 and March 2015, 34,352 Mt of ferrous and non-ferrous metals were recovered and shipped for recycling, which consisted of metals >125 mm (5.2%), 50-125 mm (85.9%), <50mm (3.4%), zorba (4.6%), and mixed products (0.8%). The conservative estimated value of the recovered metal was $7.42 million. Mining also increased the landfill's airspace by 10,194 m(3) extending the life of the ashfill with an estimated economic value of $267,000. The estimated per-Mt cost for the extraction of metal was $158. This case study demonstrates that ashfills can be profitably mined for metals without financial support from government. Although there are comparatively few ashfills, the results and experience obtained from this case study can help foster further research into the potential recovery of metals from raw, landfilled MSW.

  10. Comparison of functional deficits in the rabbit tibialis anterior following tourniquet ischemia and tourniquet compression.

    PubMed

    Ohara, W M; Pedowitz, R A; Oyama, B K; Gershuni, D H

    1996-07-01

    The purpose of this study was to measure the contractile properties of skeletal muscle after direct compression with a tourniquet and to compare these properties with those found after a similar period of tourniquet ischemia. A rabbit model of tourniquet compression of the tibialis anterior was developed and tested for this investigation. Fifty-seven animals then were divided into four protocol groups: (a) thigh tourniquet (ischemia) at 350 mm Hg (46.7 kPa), (b) leg tourniquet (compression) at 350 mm Hg (46.7 kPa), (c) leg tourniquet at 125 mm Hg (16.7 kPa), and (d) controls. A significant decrease in maximum tetanic tension was demonstrated in all three experimental groups. Direct compression at 350 mm Hg resulted in the greatest decline in maximum tetanic tension (22.6% of control), followed by compression at 125 mm Hg (30.5%) and ischemic injury (40.2%). In addition, direct compression at 350 mm Hg resulted in a significantly greater loss of force-generating capacity when compared with the ischemic group (p < 0.01). A similar pattern was noted for the rate of rise in maximum tetanic tension. Gross histologic examination of the tibialis anterior sections was consistent with the results of functional testing, with the more severe abnormalities noted in the compressed specimens. These results clearly demonstrate that tourniquet compression injury results in a more significant loss of functional strength and contractile speed than tourniquet ischemia. Further investigations on the safe limits of tourniquet use thus should be directed toward measuring the effect of the pneumatic tourniquet on the underlying soft tissues.

  11. Participation in multilateral effort to develop high performance integrated CPC evacuated collectors

    NASA Astrophysics Data System (ADS)

    Winston, R.; Ogallagher, J. J.

    1992-05-01

    The University of Chicago Solar Energy Group has had a continuing program and commitment to develop an advanced evacuated solar collector integrating nonimaging concentration into its design. During the period from 1985-1987, some of our efforts were directed toward designing and prototyping a manufacturable version of an Integrated Compound Parabolic Concentrator (ICPC) evacuated collector tube as part of an international cooperative effort involving six organizations in four different countries. This 'multilateral' project made considerable progress towards a commercially practical collector. One of two basic designs considered employed a heat pipe and an internal metal reflector CPC. We fabricated and tested two large diameter (125 mm) borosilicate glass collector tubes to explore this concept. The other design also used a large diameter (125 mm) glass tube but with a specially configured internal shaped mirror CPC coupled to a U-tube absorber. Performance projections in a variety of systems applications using the computer design tools developed by the International Energy Agency (IEA) task on evacuated collectors were used to optimize the optical and thermal design. The long-term goal of this work continues to be the development of a high efficiency, low cost solar collector to supply solar thermal energy at temperatures up to 250 C. Some experience and perspectives based on our work are presented and reviewed. Despite substantial progress, the stability of research support and the market for commercial solar thermal collectors were such that the project could not be continued. A cooperative path involving university, government, and industrial collaboration remains the most attractive near term option for developing a commercial ICPC.

  12. ED 03-2 HOME BLOOD PRESSURE MONITORING IS BETTER THAN OFFICE BP AND AMBULATORY BP: UPDATE.

    PubMed

    Kario, Kazuomi

    2016-09-01

    Out-of-office blood pressure (BP) measured by home BP monitoring (HBPM) or ambulatory BP monitoring (ABPM) was demonstrated to be superior to office BP for the prediction of cardiovascular events. The ABPM is superior to HBPM for detecting the all the BP-related risks throughout 24-hr, and the self-measured HBPM underestimates the risk of daytime stress hypertension and nocturnal hypertension. However, ABPM cannot always be provided in clinical practice, and home BP monitoring can be superior to ABPM as part of a home BP-guided antihypertension strategy in clinical practice. In clinical practice, we should use both ABPM and HBPM considering these device properties. We have developed the new ABPM device which is alternatively used as self-measure HBPM (Kario. Prog Cardiovasc Dis 2016, in press).The importance of on-treatment HBPM for the cardiovascular prognosis of hypertensive individuals was recently revealed in the largest real-world prospective study held to date, the Home blood pressure measurement with Olmesartan Naive patients to Establish Standard Target blood pressure (HONEST) study. That study of more than 21 000 hypertensive patients used HBPM, and the results demonstrated that when morning home systolic BP was well-controlled during the 2-year follow-up at < 125 mmHg, there was no increase in cardiovascular events even among the patients whose office systolic BP was ≥150 mmHg, compared with those with office systolic BP < 130 mmHg and morning home systolic BP < 125 mmHg. On the other hand, even when the office systolic BP of the HONEST study's hypertensive patients was well controlled at < 130 mmHg, the hazard ratio of cardiovascular events was 2.5 in the masked uncontrolled hypertension patients with morning systolic BP ≥145 mmHg compared with the well-controlled patients with morning systolic BP < 125 mmHg (Kario, et al. Hypertension 2014;64:989-996). The threshold of on-treatment morning BP for a significant increase in

  13. Efficacy and safety of negative pressure wound therapy for Szilagyi grade III peripheral vascular graft infection.

    PubMed

    Cheng, Hsu-Tang; Hsu, Yung-Chang; Wu, Chao-I

    2014-12-01

    A best evidence topic in vascular surgery was written according to a structured protocol. The question addressed was whether it is safe and effective to use negative pressure wound therapy (NPWT) for Szilagyi grade III (i.e. the arterial implant proper involved in the infection) peripheral vascular graft infection. Altogether, 69 papers were found using the reported search. From the search results, reference lists of potentially eligible studies and related citations in PubMed, seven papers represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. In the only randomized, controlled trial that compared NPWT (n = 10) and alginate dressing change (n = 10), the NPWT group demonstrated shorter time to full skin epithelialization (median 57 vs 104 days; P = 0.026). In the other six case series, the recruited case number ranged from 12 to 72. The mode of NPWT varied among the included studies, with the majority using a continuous negative pressure of 125 mmHg. One study combined NPWT and sartorius myoplasty, another used sartorius myoplasty in selected cases and others did not. The mean duration of using NPWT ranged from 14.2 to 43 days. The mean duration to achieve complete wound healing ranged from 24 (the study with sartorius myoplasty) to 51 days. The NPWT treatment failure rate ranged from 0 (the study with sartorius myoplasty) to 25%. The major complication of NPWT was bleeding and the incidence rate was reported to be <10%. We conclude that the amount of evidence for recommending NPWT alone as the first-line treatment for Szilagyi grade III peripheral vascular graft infection is small with only one small-sized randomized controlled trial demonstrating that NPWT alone is superior to alginate dressing change in shortening the time to complete wound healing by 2 months. Limited evidence (case series with >1 year of

  14. Binding characteristics of 125I-labelled human FSH to granulosa cells from Booroola ewes which were homozygous, heterozygous or non-carriers of a major gene(s) influencing their ovulation rate.

    PubMed

    McNatty, K P; Lun, S; Heath, D A; Hudson, N L; O'Keeffe, L E; Henderson, K M

    1989-05-01

    At 37 degrees C 125I-labelled human (h) FSH (NIAMDD-hFSH-I-3) bound rapidly to granulosa cells from Booroola and Romney ewes with 50% maximum binding achieved after 3 min and equilibrium being reached within 45 min, irrespective of whether the cells were obtained from the FF, F+ or ++ Booroola genotypes or from Romney ewes. Binding of 125I-labelled FSH followed second order kinetics and there was no effect of follicle diameter (1-2.5 mm vs greater than or equal to 3 mm). Irrespective of breed, genotype or follicle size, the mean (+/- s.e.m.) calculated association rate constant, (ka) was 7.3 (+/- 0.8) x 10(5) litres mol-1 sec-1 (n = 12). Dissociation of receptor bound 125I-labelled hFSH was less than 5% after 30 min and low but variable (i.e. between 0 and 30%) after 2-6 h irrespective of breed, genotype or follicle size. No gene-specific differences were noted in binding specificity between F+ and ++ genotypes: studies were not performed with cells from FF ewes because of insufficient cells. The binding of 125I-labelled hFSH could be displaced with sheep FSH (NIH-FSH-S16; 10% cross-reaction) and FSH-P (2.5% cross-reaction) but other sheep pituitary hormones and hCG showed little or no cross-reaction (less than or equal to 0.1%). The calculated binding capacities (Bmax) and equilibrium dissociation constants (Kd) for 125I-labelled hFSH binding to granulosa cells did not differ between the Booroola genotypes or between Booroola or Romney follicles of different diameter (i.e. 1-2.5 mm; or greater than or equal to 3 mm). The overall mean +/- s.e.m. (n = 24) Bmax and Kd values were 16.7 +/- 0.8 fm/mg protein (i.e. approximately 800 available receptor binding sites/cell) and 1.1 +/- 0.1 nM respectively. Collectively, these findings suggest that the earlier maturation of follicles in FF or F+ ewes compared to ++ ewes is unlikely to be due to gene-specific differences in the FSH binding characteristics of the granulosa cells.

  15. Treating Fasciotomy Wounds with Negative Pressure Wound Therapy with Instillation and Dwell Time (NPWTi-d)

    PubMed Central

    2016-01-01

    Acute compartment syndrome (ACS) is a serious complication of lower-extremity trauma caused by accidents or post-procedure complications. ACS is characterized by increased pressure within the compartment, resulting in reduced blood flow, tissue hypoxia, and tissue necrosis. Fasciotomies to relieve pressure and debridement of necrotic tissue comprise primary treatment. My purpose is to present initial experience using negative pressure wound therapy with instillation and dwell time (NPWTi-d)* to treat fasciotomy wounds in two patients. NPWTi-d provides automated, volumetric control of instilled topical wound solutions with a dwell time in combination with negative pressure wound therapy (NPWT). Patient 1, a 33-year-old male injured in a motorcycle accident, developed ACS within 24 hours of hospitalization. Prior treatments included wet-to-dry dressings and NPWT†. In the latter course of treatment, NPWTi-d was applied; 40 ml of normal saline (NS) were instilled with a ten-minute dwell time, followed by four hours of NPWT at ‑125 mmHg. After five days of NPWTi‑d, granulation tissue covered the bone. Four days later, the patient was discharged home. The wound continued to improve and, at the last recorded visit, was completely closed. Patient 2, a 44-year-old male, developed right lower extremity ACS due to complications post cardiac surgery. NPWT was initiated in the hospital and continued post-discharge to a nursing home. The patient was readmitted to the hospital with a right leg wound infection that was surgically debrided. NPWTi-d was then applied; 60 ml of NS were instilled with a ten-minute dwell time, followed by 3.5 hours of NPWT at -125 mmHg. After ten days of NPWTi-d, granulation tissue covered the bone. In Patient 2, NPWTi-d improved the likelihood of healing in a malnourished patient who had been critically ill by promoting granulation tissue over exposed bone. The use of NPWTi-d with NS contributed to positive outcomes for both patients. *V

  16. Effect of Different Coarse Aggregate Sizes on the Strength Characteristics of Laterized Concrete

    NASA Astrophysics Data System (ADS)

    Salau, M. A.; Busari, A. O.

    2015-11-01

    The high cost of conventional concrete materials is a major factor affecting housing delivery in developing countries such as Nigeria. Since Nigeria is blessed with abundant locally available materials like laterite, researchers have conducted comprehensive studies on the use of laterite to replace river sand partially or fully in the concrete. However, the works did not consider the optimum use of coarse aggregate to possibly improve the strength of the laterized concrete, since it is normally lower than that of normal concrete. The results of the tests showed that workability, density and compressive strength at constant water-cement ratio increase with the increase in the coarse aggregate particle size and also with curing age. As the percentage of laterite increases, there was a reduction in all these characteristics even with the particle size of coarse aggregate reduction due to loss from the aggregate-paste interface zone. Also, when sand was replaced by 25% of laterite, the 19.5mm and 12.5mm coarse aggregate particle sizes gave satisfactory results in terms of workability and compressive strength respectively at 28 days of curing age, compared to normal concrete. However, in case of 50% up to 100% laterite contents, the workability and compressive strength values were very low.

  17. Determination of mercurial species in fish by inductively coupled plasma mass spectrometry with anion exchange chromatographic separation.

    PubMed

    Chen, Xiaopan; Han, Chao; Cheng, Heyong; Liu, Jinhua; Xu, Zigang; Yin, Xuefeng

    2013-09-24

    This work demonstrated the feasibility of mercury speciation analysis by anion exchange chromatographic separation with inductively coupled plasma mass spectrometry detection. For the first time, by complexing with the mobile phase containing 3-mercapto-1-propanesulfonate into negatively charged complexes, fast separation of inorganic mercury (Hg(2+)), monomethylmercury (MeHg), ethylmercury (EtHg) and phenylmercury (PhHg) was achieved within 5 min on a 12.5-mm strong anion exchange column. The detection limits for Hg(2+), MeHg, EtHg and PhHg were 0.008, 0.024, 0.029 and 0.034 μg L(-1), respectively. The relative standard deviations of peak height and peak area (5.0 μg L(-1) for each Hg species) were all below 3%. The determined contents of Hg(2+), MeHg and total Hg in a certified reference material of fish tissue by the proposed method were in good accordance with the certified values with satisfactory recoveries. The relative errors for determining MeHg and total mercury were -2.4% and -1.2%, respectively, with an acceptable range for spike recoveries of 94-101%. Mercury speciation in 11 fish samples were then analyzed after the pretreated procedure. The mercury contents in all fish samples analyzed were found compliant with the criteria of the National Standards of China.

  18. Single-element PV and PC infrared detectors for medical applications

    NASA Astrophysics Data System (ADS)

    Kim, Young-Ho; Han, Myung-Soo; Jeoung, Min-Suk; Yim, Nam-Su; Hahn, Suk-Ryong

    2001-11-01

    In Korea, Japan and China, the measurement of surface temperature profile shown in abnormalities in neural and vascular functions, facial lesions, changes of blood stream in peripheral tissues (breast cancer, etc.), and psychosomatic problems is widely used for the diagnosis and the progress monitor of disease and symptoms (pains). For this application, single element LWIR Hg0.78Cd0.22Te photo-conductive (PC) detectors were fabricated with the wafers having a cutoff wavelength larger than 12.5 mm. The optical characteristics such as responsivity and detectivity were tested and the operation of the detectors was proved by the thermal imaging system IRIS5000. It was found that the 1/f noise makes lines and seriously degrades the thermal images. MWIR Hg0.70Cd0.30Te photo-voltaic (PV) detectors were also fabricated and tested for the medical application. However, owing to the low signal, the results were far from satisfactory. It is supposed that the integration methods are required for the single element MWIR detector.

  19. Human motion energy harvesting: numerical analysis of electromagnetic swing-excited structures

    NASA Astrophysics Data System (ADS)

    Ylli, K.; Hoffmann, D.; Willmann, A.; Folkmer, B.; Manoli, Y.

    2016-09-01

    Energy harvesting from human motion has constantly attracted scientific interest over recent years. A location where a harvesting device can easily and unobtrusively be integrated is the shoe sole, which also protects the device from exterior influences. In this work a numerical system model is developed, which can be used to simulate different inductive harvester geometries and predict their power output. Real world acceleration data is used as a model input. The model is implemented in Matlab/Simulink and subdivided into a mechanical and an electromagnetic model. The key features including the motion model and the calculation of the electromagnetic coupling coefficient are explained in detail and the model is briefly evaluated experimentally. A total of six inductive architectures, i.e. different cylindrical and rectangular magnet-coil arrangements, are then investigated in detail. The geometrical parameters are optimized for each architecture to find the best geometry within the size of 71 mm × 37.5 mm × 12.5 mm, which can be integrated into the sole. With the best overall design an average power output of 42.7 mW is simulated across an ohmic load of 41 Ohms. In addition to the respective best designs, the (dis-)advantages of each architecture are explained.

  20. Quality control for blood pressure measurement in population studies: Shibata Children's Heart Study.

    PubMed

    Yoshiike, N; Nakayama, T; Yokoyama, T; Tanaka, H; Labarthe, D R

    1997-10-01

    To investigate the relation between observer performance for blood pressure measurement in a training process and in field conditions, measurement values were studied under training and field conditions among 21 blood pressure observers of 1434 subjects aged 6-15 years in Japan. The observers received training by a videotape, which included six audiovisual presentations of a falling mercury column in a standard sphygmomanometer with Korotkoff sounds. Observer bias was measured for each trainee as the mean difference between the observed and the standard values for each blood pressure reading, including systolic (SBP), fourth-phase diastolic (K4), and fifth-phase diastolic (K5) values. In multiple linear regression analyses, each 1 mmHg increment in observer bias was equivalent to 1.27, 0.88, and 1.25 mmHg difference in actual readings of SBP, K4, and K5, respectively, in the field. This finding indicates that observer performance in videotape training is predictive of measurement behavior in the field.

  1. A quantitative cell modeling and wound-healing analysis based on the Electric Cell-substrate Impedance Sensing (ECIS) method.

    PubMed

    Yang, Jen Ming; Chen, Szi-Wen; Yang, Jhe-Hao; Hsu, Chih-Chin; Wang, Jong-Shyan

    2016-02-01

    In this paper, a quantitative modeling and wound-healing analysis of fibroblast and human keratinocyte cells is presented. Our study was conducted using a continuous cellular impedance monitoring technique, dubbed Electric Cell-substrate Impedance Sensing (ECIS). In fact, we have constructed a mathematical model for quantitatively analyzing the cultured cell growth using the time series data directly derived by ECIS in a previous work. In this study, the applicability of our model into the keratinocyte cell growth modeling analysis was assessed first. In addition, an electrical "wound-healing" assay was used as a means to evaluate the healing process of keratinocyte cells at a variety of pressures. Two innovative and new-defined indicators, dubbed cell power and cell electroactivity, respectively, were developed for quantitatively characterizing the biophysical behavior of cells. We then employed the wavelet transform method to perform a multi-scale analysis so the cell power and cell electroactivity across multiple observational time scales may be captured. Numerical results indicated that our model can well fit the data measured from the keratinocyte cell culture for cell growth modeling analysis. Also, the results produced by our quantitative analysis showed that the wound healing process was the fastest at the negative pressure of 125mmHg, which consistently agreed with the qualitative analysis results reported in previous works.

  2. Quantifying the transport of energetic materials in unsaturated sediments from cracked unexploded ordnance.

    PubMed

    Lewis, Jeffrey; Martel, Richard; Trépanier, Luc; Ampleman, Guy; Thiboutot, Sonia

    2009-01-01

    Dissolved explosive species have been found in the groundwater under military training areas. These explosives are thought to originate from munitions although the mechanism of transport to the groundwater is poorly understood. This study was conducted to determine whether ruptured unexploded ordnance may be a viable source term for these explosives. The rupturing effect of one 81 mm-mortar exploding in close proximity to another 81-mm mortar was observed and the resulting contaminants were collected. These contaminants were then subjected to leaching experiments on repacked, jack drill compacted unsaturated sediment columns in a climate controlled laboratory. The mortars which were exposed to nearby explosions were shown to be susceptible to rupturing rather than sympathetically detonating under certain conditions. The ruptured mortars released up to 166+/-2 g of pulverized explosive residues (largely Composition B) and the results from the subsequent leaching tests showed that this explosive residue is highly mobile in unsaturated sandy soil. Up to 4.45+/-1.00 g of dissolved explosive contamination was transported through the unsaturated soil columns during the first year of infiltration. The results indicate the mass of transported explosive residue dissolved in the leachate was primarily caused by the preferential dissolution of explosive contaminants having a grain size under 0.125 mm. Surface or near-surface unexploded ordnance (UXO) on live fire ranges may therefore be significant sources of explosive environmental contamination after they have been exposed to other rounds which explode nearby.

  3. The spectrum and variability of radio emission from AE Aquarii

    NASA Technical Reports Server (NTRS)

    Abada-Simon, Meil; Lecacheux, Alain; Bastian, Tim S.; Bookbinder, Jay A.; Dulk, George A.

    1993-01-01

    The first detections of the magnetic cataclysmic variable AE Aquarii at millimeter wavelengths are reported. AE Aqr was detected at wavelengths of 3.4 and 1.25 mm. These data are used to show that the time-averaged spectrum is generally well fitted by a power law S(nu) varies as nu exp alpha, where alpha is approximately equal to 0.35-0.60, and that the power law extends to millimeter wavelengths, i.e., the spectral turnover is at a frequency higher than 240 GHz. It is suggested that the spectrum is consistent with that expected from a superposition of flarelike events where the frequency distribution of the initial flux density is a power law f (S0) varies as S0 exp -epsilon, with index epsilon approximately equal to 1.8. Within the context of this model, the high turnover frequency of the radio spectrum implies magnetic field strengths in excess of 250 G in the source.

  4. An Efficient Method for Calculating the Characteristics of the Integrated Lens Antennas on the Basis of the Geometrical and Physical Optics Approximations

    NASA Astrophysics Data System (ADS)

    Mozharovskiy, A. V.; Artemenko, A. A.; Mal'tsev, A. A.; Maslennikov, R. O.; Sevast'yanov, A. G.; Ssorin, V. N.

    2015-11-01

    We develop a combined method for calculating the characteristics of the integrated lens antennas for millimeter-wave wireless local radio-communication systems on the basis of the geometrical and physical optics approximations. The method is based on the concepts of geometrical optics for calculating the electromagnetic-field distribution on the lens surface (with allowance for multiple internal re-reflections) and physical optics for determining the antenna-radiated fields in the Fraunhofer zone. Using the developed combined method, we study various integrated lens antennas on the basis of the data on the used-lens shape and material and the primary-feed radiation model, which is specified analytically or by computer simulation. Optimal values of the cylindrical-extension length, which ensure the maximum antenna directivity equal to 19.1 and 23.8 dBi for the greater and smaller lenses, respectively, are obtained for the hemispherical quartz-glass lenses having the cylindrical extensions with radii of 7.5 and 12.5 mm. In this case, the scanning-angle range of the considered antennas is greater than ±20° for an admissible 2-dB decrease in the directivity of the deflected beam. The calculation results obtained using the developed method are confirmed by the experimental studies performed for the prototypes of the integrated quartz-glass lens antennas within the framework of this research.

  5. Modification of the glass surface property in PDMS-glass hybrid microfluidic devices.

    PubMed

    Kaneda, Shohei; Ono, Koichi; Fukuba, Tatsuhiro; Nojima, Takahiko; Yamamoto, Takatoki; Fujii, Teruo

    2012-01-01

    This paper presents a simple method to change the hydrophilic nature of the glass surface in a poly(dimethylsiloxane) (PDMS)-glass hybrid microfluidic device to hydrophobic by an extra-heating step during the fabrication process. Glass substrates bonded to a native or oxygen plasma-treated PDMS chip having microchambers (12.5 mm diameter, 110 µm height) were heated at 200°C for 3 h, and then the hydrophobicity of the glass surfaces on the substrate was evaluated by measuring the contact angle of water. By the extra-heating process, the glass surfaces became hydrophobic, and its contact angle was around 109°, which is nearly the same as native PDMS surfaces. To demonstrate the usefulness of this surface modification method, a PDMS-glass hybrid microfluidic device equipped with microcapillary vent structures for pneumatic manipulation of droplets was fabricated. The feasibility of the microcapillary vent structures on the device with the hydrophobic glass surfaces are confirmed in practical use through leakage tests of the vent structures and liquid handling for the electrophoretic separation of DNA molecules.

  6. A laboratory evaluation of tagging-related mortality and tag loss in juvenile humpback chub

    USGS Publications Warehouse

    Ward, David L.; Persons, William R.; Young, Kirk; Stone, Dennis M.; Van Haverbeke, Randy; Knight, William R.

    2015-01-01

    We quantified tag retention, survival, and growth in juvenile, captive-reared Humpback Chub Gila cypha marked with three different tag types: (1) Biomark 12.5-mm, 134.2-kHz, full duplex PIT tags injected into the body cavity with a 12-gauge needle; (2) Biomark 8.4-mm, 134.2-kHz, full duplex PIT tags injected with a 16-gauge needle; and (3) Northwest Marine Technology visible implant elastomer (VIE) tags injected under the skin with a 29-gauge needle. Estimates of tag loss, tagging-induced mortality, and growth were evaluated for 60 d with each tag type for four different size-groups of fish: 40–49 mm, 50–59 mm, 60–69 mm, and 70–79 mm TL. Total length was a significant predictor of the probability of PIT tag retention and mortality for both 8-mm and 12-mm PIT tags, and the smallest fish had the highest rates of tag loss (12.5–30.0%) and mortality (7.5–20.0%). Humpback Chub of sizes 40–49 mm TL and tagged with VIE tags had no mortality but did have a 17.5% tag loss. Growth rates of all tagged fish were similar to controls. Our data indicate Humpback Chub can be effectively tagged using either 8-mm or 12-mm PIT tags with little tag loss or mortality at sizes as low as 65 mm TL.

  7. IRAS 21391 + 5802 - A study in intermediate mass star formation

    NASA Technical Reports Server (NTRS)

    Wilking, Bruce; Mundy, Lee; Mcmullin, Joseph; Hezel, Thomas; Keene, Jocelyn

    1993-01-01

    We present infrared and millimeter wavelength observations of the cold IRAS source 21391 + 5802 and its associated molecular core. Infrared observations at lambda = 3.5 microns reveal a heavily obscured, central point source which is coincident with a compact lambda = 2.7 mm continuum and C18O emission region. The source radiates about 310 solar luminosities, primarily at FIR wavelengths, suggesting that it is a young stellar object of intermediate mass. The steeply rising spectral energy distribution and the large fraction of the system mass residing in circumstellar material imply that IRAS 21391 + 5802 is in an early stage of evolution. The inferred dust temperature indicates a temperature gradient in the core. A comprehensive model for the surrounding core of dust and gas is devised to match the observed dust continuum emission and multitransition CS emission from this and previous studies. We find a r exp -1.5 +/- 0.2 density gradient consistent with that of a gravitationally evolved core and a total core mass of 380 solar masses. The observed dust emission is most consistent with a lambda exp -1.5 - lambda exp -2 dust emissivity law; for a lambda exp -2 law, the data are best fit by a mass opacity coefficient of 3.6 x 10 exp -3 sq cm/g at lambda = 1.25 mm.

  8. Hydrogen attack - Influence of hydrogen sulfide. [on carbon steel

    NASA Technical Reports Server (NTRS)

    Eliezer, D.; Nelson, H. G.

    1978-01-01

    An experimental study is conducted on 12.5-mm-thick SAE 1020 steel (plain carbon steel) plate to assess hydrogen attack at room temperature after specimen exposure at 525 C to hydrogen and a blend of hydrogen sulfide and hydrogen at a pressure of 3.5 MN/sq m for exposure times up to 240 hr. The results are discussed in terms of tensile properties, fissure formation, and surface scales. It is shown that hydrogen attack from a high-purity hydrogen environment is severe, with the formation of numerous methane fissures and bubbles along with a significant reduction in the room-temperature tensile yield and ultimate strengths. However, no hydrogen attack is observed in the hydrogen/hydrogen sulfide blend environment, i.e. no fissure or bubble formation occurred and the room-temperature tensile properties remained unchanged. It is suggested that the observed porous discontinuous scale of FeS acts as a barrier to hydrogen entry, thus reducing its effective equilibrium solubility in the iron lattice. Therefore, hydrogen attack should not occur in pressure-vessel steels used in many coal gasification processes.

  9. Effect of Layer Thickness and Printing Orientation on Mechanical Properties and Dimensional Accuracy of 3D Printed Porous Samples for Bone Tissue Engineering

    PubMed Central

    Farzadi, Arghavan; Solati-Hashjin, Mehran; Asadi-Eydivand, Mitra; Abu Osman, Noor Azuan

    2014-01-01

    Powder-based inkjet 3D printing method is one of the most attractive solid free form techniques. It involves a sequential layering process through which 3D porous scaffolds can be directly produced from computer-generated models. 3D printed products' quality are controlled by the optimal build parameters. In this study, Calcium Sulfate based powders were used for porous scaffolds fabrication. The printed scaffolds of 0.8 mm pore size, with different layer thickness and printing orientation, were subjected to the depowdering step. The effects of four layer thicknesses and printing orientations, (parallel to X, Y and Z), on the physical and mechanical properties of printed scaffolds were investigated. It was observed that the compressive strength, toughness and Young's modulus of samples with 0.1125 and 0.125 mm layer thickness were more than others. Furthermore, the results of SEM and μCT analyses showed that samples with 0.1125 mm layer thickness printed in X direction have more dimensional accuracy and significantly close to CAD software based designs with predefined pore size, porosity and pore interconnectivity. PMID:25233468

  10. Some observations on cyclic deformation structures in the high-strength commercial aluminum alloy AA 7150

    SciTech Connect

    Hanlon, D.N.; Rainforth, W.M.

    1998-11-01

    Load-controlled fatigue testing of the aluminum alloy AA 7150 has been conducted using four-point bending with an R ratio of + 0.1 over a range of maximum stress levels from 60 to 120% of the 0.2% proof stress. The alloy, in the form of 12.5-mm rolled plate, was investigated in underaged (UA), peak-aged (PA), and overaged (OA) conditions, corresponding to a change in average precipitate sizes from 5 nm in the UA condition to 21 nm in the OA condition. Three orientations of the plate were investigated. Orientation and aging condition influenced the degree of surface topographical development but not fatigue life. Detailed transmission electron microscopy (TEM) of the fatigued surface indicated that deformation in all aging conditions occurred by planar slip. Slip was generally restricted to a single slip system within each grain, and subgrain boundaries offered little resistance to dislocation movement facilitating long slip line lengths (measured up to 310 {micro}m) between adjacent high-angle grain boundaries. Planar slip observed in the OA condition is attributed to shearing of large strengthening precipitates, which is promoted by long slip line lengths. No evidence of surface specific changes in slip character was observed.

  11. Development of a 55 μm pitch 8 inch CMOS image sensor for the high resolution NDT application

    NASA Astrophysics Data System (ADS)

    Kim, M. S.; Kim, G.; Cho, G.; Kim, D.

    2016-11-01

    A CMOS image sensor (CIS) with a large area for the high resolution X-ray imaging was designed. The sensor has an active area of 125 × 125 mm2 comprised with 2304 × 2304 pixels and a pixel size of 55 × 55 μm2. First batch samples were fabricated by using an 8 inch silicon CMOS image sensor process with a stitching method. In order to evaluate the performance of the first batch samples, the electro-optical test and the X-ray test after coupling with an image intensifier screen were performed. The primary results showed that the performance of the manufactured sensors was limited by a large stray capacitance from the long path length between the analog multiplexer on the chip and the bank ADC on the data acquisition board. The measured speed and dynamic range were limited up to 12 frame per sec and 55 dB respectively, but other parameters such as the MTF, NNPS and DQE showed a good result as designed. Based on this study, the new X-ray CIS with ~ 50 μm pitch and ~ 150 cm2 active area are going to be designed for the high resolution X-ray NDT equipment for semiconductor and PCB inspections etc.

  12. Aerogel-Based Insulation for High-Temperature Industrial Processes

    SciTech Connect

    Dr. Owen Evans

    2011-10-13

    Under this program, Aspen Aerogels has developed an industrial insulation called Pyrogel HT, which is 4-5 times more thermally efficient than current non-aerogel technology. Derived from nanoporous silica aerogels, Pyrogel HT was specifically developed to address a high temperature capability gap not currently met with Aspen Aerogels{trademark} flagship product, Pyrogel XT. Pyrogel XT, which was originally developed on a separate DOE contract (DE-FG36-06GO16056), was primarily optimized for use in industrial steam processing systems, where application temperatures typically do not exceed 400 C. At the time, further improvements in thermal performance above 400 C could not be reasonably achieved for Pyrogel XT without significantly affecting other key material properties using the current technology. Cumulative sales of Pyrogel HT into domestic power plants should reach $125MM through 2030, eventually reaching about 10% of the total insulation market share in that space. Global energy savings would be expected to scale similarly. Over the same period, these sales would reduce domestic energy consumption by more than 65 TBtu. Upon branching out into all industrial processes in the 400 C-650 C regime, Pyrogel HT would reach annual sales levels of $150MM, with two-thirds of that being exported.

  13. Two-phase flow patterns characteristics analysis based on image and conductance sensors

    NASA Astrophysics Data System (ADS)

    Wang, Zhenya; Jin, Ningde; Wang, Chun; Wang, Jinxiang

    2008-10-01

    In order to study the temporal and spatial evolution characteristics of gas-liquid two-phase flow pattern, the two-phase flow monitoring system composed of high-speed dynamic camera and Vertical Multi-Electrode Array conductance sensor (VMEA) was utilized to shoot dynamic images and acquire the conductance fluctuating signals of 5 typical vertical gas-liquid two-phase flow patterns in a 125mm i.d. upward pipe. Gray level co-occurrence matrix (GLCM) was used to extract four time-varying characteristic parameter indices which represented different flow image texture structures and also Lempel-Ziv complexity of them were calculated. Then the transition of flow structure and flow property were comprehensively analyzed, combining the result derived from image information with recurrence plots (RPs) and Lempel-Ziv complexity of conductance fluctuating signals. The study showed that the line texture structure of RPs enabled to indicate flow pattern characteristics; the flow image texture structure characteristic parameters sequence described the variance of flow structure and dynamical complexity of different flow patterns.

  14. Development of a Compact Rectenna for Wireless Powering of a Head-Mountable Deep Brain Stimulation Device.

    PubMed

    Hosain, M D Kamal; Kouzani, Abbas Z; Tye, Susannah J; Abulseoud, Osama A; Amiet, Andrew; Galehdar, Amir; Kaynak, Akif; Berk, Michael

    2014-01-01

    Design of a rectangular spiral planar inverted-F antenna (PIFA) at 915 MHz for wireless power transmission applications is proposed. The antenna and rectifying circuitry form a rectenna, which can produce dc power from a distant radio frequency energy transmitter. The generated dc power is used to operate a low-power deep brain stimulation pulse generator. The proposed antenna has the dimensions of 10 mm [Formula: see text]12.5 mm [Formula: see text]1.5 mm and resonance frequency of 915 MHz with a measured bandwidth of 15 MHz at return loss of [Formula: see text]. A dielectric substrate of FR-4 of [Formula: see text] and [Formula: see text] with thickness of 1.5 mm is used for both antenna and rectifier circuit simulation and fabrication because of its availability and low cost. An L-section impedance matching circuit is used between the PIFA and voltage doubler rectifier. The impedance matching circuit also works as a low-pass filter for elimination of higher order harmonics. Maximum dc voltage at the rectenna output is 7.5 V in free space and this rectenna can drive a deep brain stimulation pulse generator at a distance of 30 cm from a radio frequency energy transmitter, which transmits power of 26.77 dBm.

  15. GEM-type detectors using LIGA and etchable glass technologies

    SciTech Connect

    Ahn, S.K.; Kim, J.G.; Perez-Mendez, V.; Chang, S.; Jackson, K.H.; Kadyk, J.A.; Wenzel, W.A.; Cho, G.

    2001-11-02

    Gas electron multipliers (GEMS) have been made by a deep X-ray lithography technique (LIGA process) using synchrotron radiation on polymethylmethacrylate (PMMA) and by UV processes using a UV etchable glass. Gain, stability and rate capability for these detectors are described.The LIGA detectors described consist of PMMA sheets of various thicknesses, 125mm to 350mm, and have 150mm x 150mm square holes spaced with a pitch of 300mm. Thin copper electrodes are plated on the top and bottom surfaces using a Damascene method, followed by electroless plating of the copper onto a palladium-tin base layer. For various thicknesses of PMMA measurements have been made of absolute gain vs. voltage, time stability of gain, and rate capability. The operating gas mixture was usually Ar/CO2 (70/30) gas, but some tests were also done using P10 gas. We also made GEM-like detectors using the UV etchable glass called Foturan, patterned by exposure to UV light and subsequent etching. A few measurements using these detectors will be reported, including avalanche gain and time stability.

  16. The Solanum lycopersicum Zinc Finger2 Cysteine-2/Histidine-2 Repressor-Like Transcription Factor Regulates Development and Tolerance to Salinity in Tomato and Arabidopsis1[W

    PubMed Central

    Hichri, Imène; Muhovski, Yordan; Žižková, Eva; Dobrev, Petre I.; Franco-Zorrilla, Jose Manuel; Solano, Roberto; Lopez-Vidriero, Irene; Motyka, Vaclav; Lutts, Stanley

    2014-01-01

    The zinc finger superfamily includes transcription factors that regulate multiple aspects of plant development and were recently shown to regulate abiotic stress tolerance. Cultivated tomato (Solanum lycopersicum Zinc Finger2 [SIZF2]) is a cysteine-2/histidine-2-type zinc finger transcription factor bearing an ERF-associated amphiphilic repression domain and binding to the ACGTCAGTG sequence containing two AGT core motifs. SlZF2 is ubiquitously expressed during plant development, and is rapidly induced by sodium chloride, drought, and potassium chloride treatments. Its ectopic expression in Arabidopsis (Arabidopsis thaliana) and tomato impaired development and influenced leaf and flower shape, while causing a general stress visible by anthocyanin and malonyldialdehyde accumulation. SlZF2 enhanced salt sensitivity in Arabidopsis, whereas SlZF2 delayed senescence and improved tomato salt tolerance, particularly by maintaining photosynthesis and increasing polyamine biosynthesis, in salt-treated hydroponic cultures (125 mm sodium chloride, 20 d). SlZF2 may be involved in abscisic acid (ABA) biosynthesis/signaling, because SlZF2 is rapidly induced by ABA treatment and 35S::SlZF2 tomatoes accumulate more ABA than wild-type plants. Transcriptome analysis of 35S::SlZF2 revealed that SlZF2 both increased and reduced expression of a comparable number of genes involved in various physiological processes such as photosynthesis, polyamine biosynthesis, and hormone (notably ABA) biosynthesis/signaling. Involvement of these different metabolic pathways in salt stress tolerance is discussed. PMID:24567191

  17. Compact turnkey focussing neutron guide system for inelastic scattering investigations

    NASA Astrophysics Data System (ADS)

    Brandl, G.; Georgii, R.; Dunsiger, S. R.; Tsurkan, V.; Loidl, A.; Adams, T.; Pfleiderer, C.; Böni, P.

    2015-12-01

    We demonstrate the performance of a compact neutron guide module which boosts the intensity in inelastic neutron scattering experiments by approximately a factor of 40. The module consists of two housings containing truly curved elliptic focussing guide elements, positioned before and after the sample. The advantage of the module lies in the ease with which it may be reproducibly mounted on a spectrometer within a few hours, on the same timescale as conventional sample environments. It is particularly well suited for samples with a volume of a few mm3, thus enabling the investigation of materials which to date would have been considered prohibitively small or samples exposed to extreme environments, where there are space constraints. We benchmark the excellent performance of the module by measurements of the structural and magnetic excitations in single crystals of model systems. In particular, we report the phonon dispersion in the simple element lead. We also determine the magnon dispersion in the spinel ZnCr2Se4 (V = 12.5 mm3), where strong magnetic diffuse scattering at low temperatures evolves into distinct helical order.

  18. Studies into Using Manure in a Biorefinery Concept

    SciTech Connect

    Chen, Shulin; Wen, Zhiyou; Liao, Wei; Liu, Chuanbin; Kincaid, R. L.; Harrison, J. H.; Elliott, Douglas C.; Brown, Michael D.; Stevens, Don J.

    2005-03-01

    Animal manure is an underutilized biomass resource containing a large amount of organic carbon that is often wasted in the existing manure disposal practices. A research project funded by the US Department of Energy explored the feasibility of using manure via the sugar platform in a biorefinery. The results showed that fiber, the major component of dry manure, constituted approximately 50%, 40%, and 36% of the dry dairy, swine, and poultry manure materials, respectively. The highest fiber contents were in dairy manure of which more than 75% of the dry matter was in the particles greater than 0.125 mm. Manure can be used for substrate to produce cellulase on site. The hemicellulose component in the manure fiber could be readily converted to sugar through acid hydrolysis. Concentrated acid treatment was most effective in manure cellulose decrystallization. The effectiveness of enzymatic hydrolysis was limited without concentrated acid pretreatment. The high protein content in manure had negative affects on acid hydrolysis. Purification and separation is necessary for further chemical conversion of the sugar to value-added chemicals through hydrogenation.

  19. Silicone-coated non-woven polyester dressing enhances reepithelialisation in a sheep model of dermal wounds.

    PubMed

    Losi, Paola; Briganti, Enrica; Costa, Manolo; Sanguinetti, Elena; Soldani, Giorgio

    2012-09-01

    Negative-pressure wound therapy (NPWT) also known as V.A.C. (Vacuum-assisted closure), is widely used to manage various type of wounds and accelerate healing. NPWT has so far been delivered mainly via open-cell polyurethane (PU) foam or medical gauze. In this study an experimental setup of sheep wound model was used to evaluate, under NPWT conditions, the performance of a silicone-coated non-woven polyester (N-WPE) compared with PU foam and cotton hydrophilic gauze, used as reference materials. Animals were anesthetized with spontaneous breathing to create three 3 × 3 cm skin defects bilaterally; each animal received three different samples on each side (n = 6 in each experimental group) and was subjected to negative and continuous 125 mmHg pressure up to 16 days. Wound conditions after 1, 8 and 16 days of treatment with the wound dressings were evaluated based on gross and histological appearances. Skin defects treated with the silicone-coated N-WPE showed a significant decrease in wound size, an increase of re-epithelialization, collagen deposition and wound neovascularisation, and a minimal stickiness to the wound tissue, in comparison with gauze and PU foam. Taken all together these findings indicate that the silicone-coated N-WPE dressing enhances wound healing since stimulates higher granulation tissue formation and causes minor tissue trauma during dressing changes.

  20. Now the Dark Electron Multiplier does Sense Direction of the Daemon Motion

    NASA Astrophysics Data System (ADS)

    Drobyshevski, E. M.; Drobyshevski, M. E.; Pikulin, V. A.

    Detection of the September maximum in the primary near-Earth daemon flux at high (~ 60°) Northern latitudes by our setup with a plane horizontal scintillator is plagued by purely geometric factors; indeed, because of the Earth's rotation axis being tilted, the daemons catching up with the Earth in outer Near-Earth, Almost Circular Heliocentric Orbits (NEACHOs) strike the Earth along close-to-horizontal paths. Nevertheless, application of only two oppositely oriented, specially designed "dark electron multipliers" of the type TEU-167d (only their ø125-mm front disc is coated on the inside by a thick, ~ 0.5 μm Al layer, which permits such multipliers to detect primarily daemons flying inside them from the base to the disc) has made it possible for us to detect in one experiment, at a confidence level of >3σ, a flux of daemons captured from NEACHOs into Geocentric Earth-Surface-Crossing Orbits, as well as to record a decrease in the velocity of these objects from ~ 10 to ~ 7 km/s in a characteristic time of ~ 1 month resulting from their being slowed down in transits through the Earth's body.

  1. A contact-lens-shaped IC chip technology

    NASA Astrophysics Data System (ADS)

    Liu, Ching-Yu; Yang, Frank; Teng, Chih-Chiao; Fan, Long-Sheng

    2014-04-01

    We report on novel contact-lens-shaped silicon integrated circuit chip technology for applications such as forming a conforming retinal prosthesis. This is achieved by means of patterning thin films of high residual stress on top of a shaped thin silicon substrate. Several strategies are employed to achieve curvatures of various amounts. Firstly, high residual stress on a thin film makes a thin chip deform into a designed three-dimensional shape. Also, a series of patterned stress films and ‘petal-shaped’ chips were fabricated and analyzed. Large curvatures can also be formed and maintained by the packaging process of bonding the chips to constraining elements such as thin-film polymer ring structures. As a demonstration, a complementary metal oxide semiconductor transistor (CMOS) image-sensing retina chip is made into a contact-lens shape conforming to a human eyeball 12.5 mm in radius. This non-planar and flexible chip technology provides a desirable device surface interface to soft tissues or non-planar bio surfaces and opens up many other possibilities for biomedical applications.

  2. Effects of enriched housing on functional recovery after spinal cord contusive injury in the adult rat.

    PubMed

    Lankhorst, A J; ter Laak, M P; van Laar, T J; van Meeteren, N L; de Groot, J C; Schrama, L H; Hamers, F P; Gispen, W H

    2001-02-01

    To date, most research performed in the area of spinal cord injury focuses on treatments designed to either prevent spreading lesion (secondary injury) or to enhance outgrowth of long descending and ascending fiber tracts around or through the lesion. In the last decade, however, several authors have shown that it is possible to enhance locomotor function after spinal cord injury in both animals and patients using specific training paradigms. As a first step towards combining such training paradigms with pharmacotherapy, we evaluated recovery of function in adult rats sustaining a spinal cord contusion injury (MASCIS device, 12.5 mm at T8), either housed in an enriched environment or in standard cages (n = 15 in both groups). The animals in the enriched environment were stimulated to increase their locomotor activity by placing water and food on opposite sides of the cage. As extra stimuli, a running wheel and several other objects were added to the cage. We show that exposure to the enriched environment improves gross and fine locomotor recovery as measured by the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale, the BBB subscale, the Gridwalk, and the Thoracolumbar height test. However, no group differences were found on our electrophysiological parameters nor on the amount of spared white matter. These data justify further studies on enriched housing and more controlled exercise training, with their use as potential additive to pharmacological intervention.

  3. Calcification classifications of small nodules identified during CT lung cancer screening

    NASA Astrophysics Data System (ADS)

    Judy, Philip F.; Riva, Roberto; Kadota, Yoshiko; Jacobson, Francine L.

    2004-05-01

    The aim of this study was to determine whether radiologists are more likely to report as calcified the small nodules detected during CT lung-cancer screening, if sharper reconstruction filters are utilized. Images were reconstructed with the 2 filters used at our institution for the lung (B50f) and for the mediastinum (B30f). The 4 lung-cancer screening cases were reconstructed with 1.25-mm section thickness at 0.6-mm section increments. Using a lax criterion, 2 radiologists identified the locations of nodular features and rated the likelihood that the features were calcified. There were 302 nodules reports. More of these (57%) were reported on images reconstructed using the smooth filter. Sixty (60) reports were definitely or possibly calcified. Seventy-three percent (73%) calcification reports were from images reconstructed using B50f. There were 27 calcification reports of one of the radiologist that were classified as non-calcified by the other radiologist. Most of calcification reports (81%) of 27 reports on which radiologists disagree regarding the likelihood of calcification were from images reconstructed using B50f. Radiologists are more likely to report small nodules detected during lung-cancer screening as calcified using the sharper reconstruction filter. Whether these nodules are actually calcified or not remains a question.

  4. Size characteristics of stones ingested by common loons

    USGS Publications Warehouse

    Franson, J. Christian; Hansen, Scott P.; Pokras, Mark; Miconi, Rose

    2001-01-01

    Common Loon (Gavia immer) carcasses recovered in New England had more stones of greater combined mass in their stomachs than loons from the southeastern United States. Stones retained in sieves with mesh sizes between 4.75 and 8.00 mm accounted for the greatest percentage (by mass) of grit in loon stomachs. The median longest dimension of the largest single stone in each stomach was 12.5 mm in loons from New England and 10.7 mm in loons from the southeast (maximum = 23.1 mm and 16.8 mm, respectively). A recent national proposal to restrict the use of certain fishing weights in the United States called for a ban on lead fishing sinkers of 25.4 mm or less in any dimension. Our findings suggest it is unlikely that Common Loons would ingest lead fishing weights greater than 25.4 mm in any dimension, if such ingestion was solely the result of their search for replacement stones for their stomachs. However, this does not preclude the possibility that loons may ingest larger fishing weights under other circumstances, such as the consumption of fish with attached sinkers.

  5. Measurement of tear production using phenol red thread and standardized endodontic absorbent paper points in European pond turtles (Emys orbicularis).

    PubMed

    Rajaei, Seyed Mehdi; Mood, Maneli Ansari; Ghaffari, Masoud Selk; Williams, David L

    2014-12-01

    The objective of this study was to determine the aqueous fraction of the tear film using the phenol red thread test (PRTT) and paper point tear test (PPTT) in healthy adult European pond turtles (Emys orbicularis). Twenty-four healthy adult European pond turtles were studied. Measurement of tear secretion was performed using the PRTT and standardized endodontic absorbent PPTT. Horizontal palpebral fissure length (HPFL) was measured using digital calipers and was correlated with the weight of the animal. The mean ± SD PRTT, PPTT, and HPFL values for the left and right eyes were 5.12 ± 1.54 mm/15 sec and 4.62 ± 1.76 mm/15 sec; 4.50 ± 1.25 mm/1 min and 4.20 ± 1.53 mm/1 min; and 8.4 ± 0.6 mm and 8.3 ± 0.6 mm, respectively. No significant differences were detected between right and left eyes of individual turtles or between males and females in all tests. This study represents reference values of tear production in European pond turtles obtained from PRTT and PPTT methods and forms an important baseline study in defining the healthy chelonian ocular surface.

  6. An intrinsic fiber-optic single loop micro-displacement sensor.

    PubMed

    Martinez-Rios, Alejandro; Monzon-Hernandez, David; Torres-Gomez, Ismael; Salceda-Delgado, Guillermo

    2012-01-01

    A micro-displacement sensor consisting of a fiber-loop made with a tapered fiber is reported. The sensor operation is based on the interaction between the fundamental cladding mode propagating through the taper waist and higher order cladding modes excited when the taper is deformed to form a loop. As a result, a transmission spectrum with several notches is observed, where the notch wavelength resonances shift as a function of the loop diameter. The loop diameter is varied by the spatial displacement of one end of the fiber-loop attached to a linear translation stage. In a displacement range of 3.125 mm the maximum wavelength shift is 360.93 nm, with 0.116 nm/μm sensitivity. By using a 1,280 nm broadband low-power LED source and a single Ge-photodetector in a power transmission sensor setup, a sensitivity in the order of 2.7 nW/μm is obtained in ≈ 1 mm range. The proposed sensor is easy to implement and has a plenty of room to improve its performance.

  7. Deep Orbital Dermoid Cyst Bulging into the Superior Orbital Fissure: Clinical Presentation and Management

    PubMed Central

    Kumar, Ravinder; Vyas, Kapil; Jaiswal, Gagan; Bhargava, Abhishek; Kundu, Jyoti

    2017-01-01

    Purpose: To present a case of deep orbital dermoid cyst with emphasis on clinical presentation, imaging spectrum, differential diagnosis and management. Case Report: A 28-year-old female was referred to our hospital with chief complaint of drooping of right eyelid and progressive headache. Ocular motility, visual acuity and fundus examination were normal. computed tomography (CT) and magnetic resonance imaging (MRI) revealed a well-defined, intraosseous deep orbital dermoid cyst (5.9 mm × 12.5 mm) located near the apex of right orbit, extending from greater wing of sphenoid into the superior orbital fissure. Due to occulomotor nerve (superior and inferior divisions) compression which passes through the superior orbital fissure, ipsilateral headache and ptosis occurred. Complete surgical excision of cyst was performed using noninvasive extracranial lateral orbitotomy approach. After removal of the cyst, curette and cutting drill were used to thoroughly remove any residual cystic content. Histopathological analysis confirmed the diagnosis. The healing was uneventful postoperatively. Conclusion: CT and MRI are easy, reliable, safe and effective imaging methods for establishing the diagnosis of orbital dermoid cyst. Size, location and manifestations are the most important determinants of the disease management. Complete surgical excision without rupture of the cyst is the treatment of choice. PMID:28299014

  8. A sub-10 nA DC-balanced adaptive stimulator IC with multi-modal sensor for compact electro-acupuncture stimulation.

    PubMed

    Song, Kiseok; Lee, Hyungwoo; Hong, Sunjoo; Cho, Hyunwoo; Ha, Unsoo; Yoo, Hoi-Jun

    2012-12-01

    A compact electro-acupuncture (EA) system is proposed for a multi-modal feedback EA treatment. It is composed of a needle, a compact EA patch, and an interconnecting conductive thread. The 3 cm diameter compact EA patch is implemented with an adaptive stimulator IC and a small coin battery on the planar-fashionable circuit board (P-FCB) technology. The adaptive stimulator IC can form a closed current loop for even a single needle, and measure the electromyography (EMG) and the skin temperature to analyze the stimulation status as well as supply programmable stimulation current (40 μA-1 mA) with 5 different modes. The large time constant (LTC) sample and hold (S/H) current matching technique achieves the high-precision charge balancing ( <;10 nA) for the patient's safety. The measured data can be wirelessly transmitted to the external EA analyzer through the body channel communication (BCC) transceiver for the low power consumption. The external EA analyzer can show the patient's status, such as the muscle fatigue and the change of the skin temperature. Based on these analyses, the practitioner can adaptively change the stimulation parameters for the optimal treatment value. A 12.5 mm(2) 0.13 μm RF CMOS stimulator chip consumes 6.8 mW at 1.2 V supporting 32 different current levels. The proposed compact EA system is fully implemented and tested on the human body.

  9. Separation of fossil resin from northeast China coal

    SciTech Connect

    Xie, H.; Cao, J.; Huang, B.; Zhang, R.Z.; Xia, Q.

    1997-12-31

    Some coalfields in China contain macroscopic fossil resins. These fossil resins have not been recovered commercially. The distribution of fossil resin in coal from northeast China was characterized before recovering it by flotation and gravity separation. The fossil resin particles whose weight accounted for more than 99% of all fossil resin in the sample were larger than 0.125mm. A concentrate product that contained almost 100% fossil resin at a recovery of more than 88% was obtained from a feed containing 1.72% fossil resin using a shaking table followed by float-sink separation with a sodium chloride solution (1.1g/ml). By conventional single stage flotation, a fossil resin concentrate containing 48% fossil resin at a recovery of 95% was obtained from a feed containing 11.4% fossil resin. Adjusting the pH of the slurry with HCl or CaO before flotation did not improve the selectivity of flotation for fossil resin appreciably. Treating the feed with H{sub 2}O{sub 2} solution before flotation increased the grade of the concentrate to a certain extent, but decreased the recovery of fossil resin greatly.

  10. The use of negative pressure in critical necrotizing fasciitis treatment: a case presentation.

    PubMed

    Ge, Kui; Xu, Bing; Wu, Jia-Jun; Wu, Minjie; Lu, Shuliang; Xie, Ting

    2014-09-01

    Surgery complemented by antibiotics forms the backbone of the successful management of necrotizing fasciitis. But it will be very difficult to clear away extensive necrotizing tissue thoroughly in critically ill patients when their vital signs are unstable. The authors report the case of a 33-year-old woman who had extensive necrotizing fasciitis of the right lower limb with septic shock. The patient was severely anemic and malnutrition and had been given conservative debridement at bedside, that is, only detached necrotizing tissues was taken away while some other necrotizing tissue still remained, so that the skin tissue within the same area could be saved as much as possible. After debridement, negative pressure was applied at 125 mm Hg. Broad-spectrum antibiotics and effective supplementation were also complemented, thus controlling the septic shock. All necrotizing tissues were detached, and the sparing vital skin on necrotizing fascia was preserved successfully after negative pressure treatment. The patient was finally saved. In conclusion, negative pressure treatment may help diminish toxin absorbance, detach gangrene tissue, and preserve sparing vital tissue. This case suggests the value of combined use of negative pressure therapy and conservative debridement in critically ill patients with extensive necrotizing fasciitis.

  11. Stability of [6]-gingerol and [6]-shogaol in simulated gastric and intestinal fluids.

    PubMed

    Bhattarai, Sushila; Tran, Van H; Duke, Colin C

    2007-11-30

    The degradation kinetics of [6]-gingerol and [6]-shogaol were investigated in simulated gastric (pH 1) and intestinal (pH 7.4) fluids at 37 degrees C. Degradation products were quantitatively determined by HPLC (Lichrospher 60 RP select B column, 5 microm, 125 mm x 4 mm; mobile phase: methanol-water-acetic acid (60:39:1 v/v); flow rate: 0.6 ml/min; detection UV: 280 nm). In simulated gastric fluid (SGF) [6]-gingerol and [6]-shogaol underwent first-order reversible dehydration and hydration reactions to form [6]-shogaol and [6]-gingerol, respectively. The degradation was catalyzed by hydrogen ions and reached equilibrium at approximately 200 h. In simulated intestinal fluid (SIF) both [6]-gingerol and [6]-shogaol showed insignificant interconversion between one another. Addition of amino acids glycine, 3-amino propionic acid (beta-alanine) and gamma-amino butyric acid (GABA), and ammonium acetate at a range of concentrations of 0.05-0.5mM had no effect on the rate of degradation of [6]-shogaol in SGF and 0.1M HCl solution. However, at exceedingly high concentration (0.5M) of ammonium acetate and glycine, significant amounts of [6]-shogaol ammonia and glycine adducts were detected. The degradation profile of [6]-gingerol and [6]-shogaol under simulated physiological conditions reported in this study will provide insight into the stability of these compounds when administered orally.

  12. A Fisheries Evaluation of the Dryden Fish Screening Facility : Annual Report 1994.

    SciTech Connect

    Mueller, Robert P.; Abernethy, C.Scott; Neitzel, Duane A.

    1995-04-01

    Effectivness was evaluated of the Dryden Fish Screening Facility in the Wenatchee Reclamation District Canal near Dryden in north central Washington State. In situ tests were conducted by releasing groups of hatchery reared salmonids of different ages and sizes. Spring chinook salmon smolts (110-165 mm) were not injured or descaled in passing through the canal forebay. Smolts were not delayed as they migrated in the canal. Most fish released at the canal headworks exited the screening facility in <4 h, with >99% of the test fish captured in the fish bypass in <24 h. Steelhead subyearlings 65-125 mm were not injured or descaled in traveling through the bypass flume and fish return pipe. Average time for steelhead subyearlings to travel through thebypass structure was 70 seconds. Small rainbow trout fry 23-27mm could pass through the 0.125-in. profile bar screen openings and were entrained in the irrigation canal; about 38% was lost to the canal within 48 h of release. Some fry stayed in the forebay and did not migrate during the tests. Wild chinook fry 36-42mm were also entrained. Estimated 34% of emergent wild chinook salmon fry passed through the profile bar screens and were entrained in the canal. Approach velocity at the Dryden screens was {ge}0.4 ft/s; low velocities through the first two screen panels indicated that vertical louvers installed behind each screen panel to balance flow were not totally effective.

  13. Investigation of MMOD Impact on STS-115 Shuttle Payload Bay Door Radiator

    NASA Technical Reports Server (NTRS)

    Hyde, J.; Christiansen, E.; Lear, D.; Kerr, J.; Lyons, F.; Yasensky, J.

    2007-01-01

    The Orbiter radiator system consists of eight individual 4.6 m x 3.2 m panels located with four on each payload bay door. Forward panels #1 and #2 are 2.3 cm thick while the aft panels #3 and #4 have a smaller overall thickness of 1.3 cm. The honeycomb radiator panels consist of 0.028 cm thick Aluminum 2024-T81 facesheets and Al5056-H39 cores. The face-sheets are topped with 0.005 in. (0.127 mm) silver-Teflon tape. The radiators are located on the inside of the shuttle payload bay doors, which are closed during ascent and reentry, limiting damage to the on-orbit portion of the mission. Post-flight inspections at the Kennedy Space Center (KSC) following the STS-115 mission revealed a large micrometeoroid/orbital debris (MMOD) impact near the hinge line on the #4 starboard payload bay door radiator panel. The features of this impact make it the largest ever recorded on an orbiter payload bay door radiator. The general location of the damage site and the adjacent radiator panels can be seen in Figure 2. Initial measurements of the defect indicated that the hole in the facesheet was 0.108 in. (2.74 mm) in diameter. Figure 3 shows an image of the front side damage. Subsequent observations revealed exit damage on the rear facesheet. Impact damage features on the rear facesheet included a 0.03 in. diameter hole (0.76 mm), a approx.0.05 in. tall bulge (approx.1.3 mm), and a larger approx.0.2 in. tall bulge (approx.5.1 mm) that exhibited a crack over 0.27 in. (6.8 mm) long. A large approx.1 in. (25 mm) diameter region of the honeycomb core was also damaged. Refer to Figure 4 for an image of the backside damage to the panel. No damage was found on thermal blankets or payload bay door structure under the radiator panel. Figure 5 shows the front facesheet with the thermal tape removed. Ultrasound examination indicated a maximum facesheet debond extent of approximately 1 in. (25 mm) from the entry hole. X-ray examinations revealed damage to an estimated 31 honeycomb cells with an extent of 0.85 in. x 1.1 in. (21.6 x 27.9 mm). Pieces of the radiator at and surrounding the impact site were recovered during the repair procedures at KSC. They included the thermal tape, front facesheet, honeycomb core, and rear facesheet. These articles were examined at JSC using a scanning electron microscope (SEM) with an energy dispersive x-ray spectrometer (EDS). Figure 6 shows SEM images of the entry hole in the facesheet. The asymmetric height of the lip may be attributed to projectile shape and impact angle. Numerous instances of a glass-fiber organic matrix composite were observed in the facesheet tape sample. The fibers were approximately 10 micrometers in diameter and variable lengths. EDS analysis indicated a composition of Mg, Ca, Al, Si, and O. Figures 7 and 8 present images of the fiber bundles, which were believed to be circuit board material based on similarity in fiber diameter, orientation, consistency, and composition. A test program was initiated in an attempt to simulate the observed damage to the radiator facesheet and honeycomb. Twelve test shots were performed using projectiles cut from a 1.6 mm thick fiberglass circuit board substrate panel. Results from test HITF07017, shown in figures 9 and 10, correlates with the observed impact features reasonably well. The test was performed at 4.14 km/sec with an impact angle of 45 degrees using a cylindrical projectile with a diameter and length of 1.25 mm. The fiberglass circuit board material had a density of 1.65 g/cu cm, giving a projectile mass of 2.53 mg. An analysis was performed using the Bumper code to estimate the probability of impact to the shuttle from a 1.25 mm diameter particle. Table 1 shows a 1.6% chance (impact odds = 1 in 62) of a 1.25 mm or larger MMOD impact on the radiators of the vehicle during a typical ISS mission. There is a 0.4% chance (impact odds = 1 in 260) that a 1.25 mm or larger MMOD particle would impact the RCC wing leading edge and nose cap during a typical miion. Figure 11 illustrates the vulnerable areas of the wing leading edge reinforced carbon-carbon (RCC), an area of the vehicle that is very sensitive to impact damage. The highlighted red, orange, yellow, and light green areas would be expected to experience critical damage if impacted by an OD particle such as the one that hit the RH4 radiator panel on STS-115.

  14. Long-term Results from Cyclocryotherapy Applied to the 3O'clock and 9O'clock Positions in Blind Refractory Glaucoma Patients

    PubMed Central

    Kim, Byoung Seon; Kim, Young Jun; Seo, Seong Wook; Yoo, Ji Myong

    2015-01-01

    Purpose To report the long-term follow-up results after cyclocryotherapy, applied to the 3-o'clock and 9-o'clock positions in blind refractory glaucoma patients. Methods We retrospectively reviewed the charts of 19 blind patients, and a total of 20 eyes with refractory glaucoma who were treated with cyclocryotherapy. Cyclocryotherapy treatments were performed using a retinal cryoprobe. The temperature of each cyclocryotherapy spot was -80℃ and each spot was maintained in place for 60 seconds. Six cyclocryotherapy spots were placed in each quadrant, including the 3-o'clock and 9-o'clock positions. Results The mean baseline pretreatment intraocular pressure (IOP) in all eyes was 50.9 ± 12.5 mmHg, which significantly decreased to a mean IOP at last follow-up of 14.1 ± 7.1 mmHg (p < 0.001). The mean number of antiglaucoma medications that patients were still taking at last follow-up was 0.3 ± 0.6. Devastating post-procedure phthisis occurred in only one eye. Conclusions Cyclocryotherapy, performed at each quadrant and at the 3-o'clock and 9-o'clock position, is an effective way to lower IOP and, thus, is a reasonable treatment option for refractory glaucoma patients who experience with ocular pain and headaches. PMID:25646060

  15. The induction of dentin bridge-like structures by constructs of subcultured dental pulp-derived cells and porous HA/TCP in porcine teeth.

    PubMed

    Ando, Yusuke; Honda, Masaki J; Ohshima, Hayato; Tonomura, Akiko; Ohara, Takayuki; Itaya, Toshimitsu; Kagami, Hideaki; Ueda, Minoru

    2009-02-01

    The purpose of this study was to investigate dentin-bridge formation in teeth following the transplantation of dental pulp-derived cells seeded on hydroxyapatite/tricalcium phosphate (HA/TCP) scaffolds. The dental pulp tissues were removed from the extracted first molar teeth of miniature pigs and single cell populations were subcultured. Second-passage cells that had alkaline phosphatase activity were combined with scaffolds. Cell-scaffold constructs were placed in contact with the exposed pulp tissue. The dimensions of the exposed pulp site were approximately 1-2.5 mm in diameter and 2-3 mm in depth from the tooth surface. After placing the constructs, the tooth was restored with composite resin. Six weeks after transplantation, hard tissue formation was observed on the pulp tissue in histology. Dentinal tubule-like structures were observed in most of the hard tissue generated, and columnar cells, which showed positive immunoreactions with dentin sialoprotein (DSP) and heat shock protein (HSP)-25, were aligned beneath the hard tissues. When only scaffolds were placed on the pulp tissues, particles of hard tissue were formed, however dentinal tubule-like structures and odontoblasts were not observed despite the formation of hard tissue. In conclusion, the implantation of dental pulp constructs into pulp exposed stimulates the formation of calcified dentin-like structures.

  16. High bacterial load in negative pressure wound therapy (NPWT) foams used in the treatment of chronic wounds.

    PubMed

    Yusuf, Erlangga; Jordan, Xavier; Clauss, Martin; Borens, Olivier; Mäder, Mark; Trampuz, Andrej

    2013-01-01

    No earlier study has investigated the microbiology of negative pressure wound therapy (NPWT) foam using a standardized manner. The purpose of this study is to investigate the bacterial load and microbiological dynamics in NPWT foam removed from chronic wounds (>3 months). To determine the bacterial load, a standardized size of the removed NPWT foam was sonicated. The resulting sonication fluid was cultured, and the colony-forming units (CFU) of each species were enumerated. Sixty-eight foams from 17 patients (mean age 63 years, 71% males) were investigated. In 65 (97%) foams, ≥ 1 and in 37 (54%) ≥ 2 bacterial types were found. The bacterial load remained high during NPWT treatment, ranging from 10(4) to 10(6) CFU/ml. In three patients (27%), additional type of bacteria was found in subsequent foam cultures. The mean bacterial count ± standard deviation was higher in polyvinyl alcohol foam (6.1 ± 0.5 CFU/ml) than in polyurethane (5.5 ± 0.8 CFU/ml) (p = 0.02). The mean of log of sum of CFU/ml in foam from 125 mmHg (5.5 ± 0.8) was lower than in foam from 100 mmHg pressure (5.9 ± 0.5) (p = 0.01). Concluding, bacterial load remains high in NPWT foam, and routine changing does not reduce the load.

  17. Comparison of objects detection capabilities in LWIR and THz ranges

    NASA Astrophysics Data System (ADS)

    Kowalski, Marcin; Kastek, Mariusz; Szustakowski, Mieczyslaw

    2015-10-01

    Multispectral systems for detection of concealed dangerous objects are becoming more popular because of their higher effectiveness compared to mono-spectral systems. So far, the problem of detecting objects hidden under clothing was considered only in the case of airports but it is becoming more important for public places like metro stations, and government buildings. Exploration of new spectral bands as well as development of technology result in introduction of new solutions - both mono and multispectral. It has been proved that objects hidden under clothing can be detected and visualized using terahertz (THz) cameras. However, passive THz cameras still offer too low image resolution for objects recognition. Limited range is another issue of passive imagers. On the other hand new infrared cameras offer sufficient parameters to detect objects covered with fabrics in some conditions, as well as high image quality and big pixel resolutions. The purpose of the studies is to investigate and compare the possibilities of using passive cameras operating in long wavelength infrared (LWIR) and THz spectral ranges for detection of concealed objects. For the purpose of investigations, commercial imagers operating in 6.5-11.7 μm and 250GHz (1.25mm) were used. In the article, we present the measurement setup and the results of measurements in various operating conditions. Theoretical studies of both spectral bands focused on detection of objects with passive imagers are also presented.

  18. The effect of CT scanner parameters and 3D volume rendering techniques on the accuracy of linear, angular, and volumetric measurements of the mandible

    PubMed Central

    Whyms, B.J.; Vorperian, H.K.; Gentry, L.R.; Schimek, E.M.; Bersu, E.T.; Chung, M.K.

    2013-01-01

    Objectives This study investigates the effect of scanning parameters on the accuracy of measurements from three-dimensional multi-detector computed tomography (3D-CT) mandible renderings. A broader range of acceptable parameters can increase the availability of CT studies for retrospective analysis. Study Design Three human mandibles and a phantom object were scanned using 18 combinations of slice thickness, field of view, and reconstruction algorithm and three different threshold-based segmentations. Measurements of 3D-CT models and specimens were compared. Results Linear and angular measurements were accurate, irrespective of scanner parameters or rendering technique. Volume measurements were accurate with a slice thickness of 1.25 mm, but not 2.5 mm. Surface area measurements were consistently inflated. Conclusions Linear, angular and volumetric measurements of mandible 3D-CT models can be confidently obtained from a range of parameters and rendering techniques. Slice thickness is the primary factor affecting volume measurements. These findings should also apply to 3D rendering using cone-beam-CT. PMID:23601224

  19. Effects of maximum aggregate size on UPV of brick aggregate concrete.

    PubMed

    Mohammed, Tarek Uddin; Mahmood, Aziz Hasan

    2016-07-01

    Investigation was carried out to study the effects of maximum aggregate size (MAS) (12.5mm, 19.0mm, 25.0mm, 37.5mm, and 50.0mm) on ultrasonic pulse velocity (UPV) of concrete. For investigation, first class bricks were collected and broken to make coarse aggregate. The aggregates were tested for specific gravity, absorption capacity, unit weight, and abrasion resistance. Cylindrical concrete specimens were made with different sand to aggregate volume ratio (s/a) (0.40 and 0.45), W/C ratio (0.45, 0.50, and 0.55), and cement content (375kg/m(3) and 400kg/m(3)). The specimens were tested for compressive strength and Young's modulus. UPV through wet specimen was measured using Portable Ultrasonic Non-destructive Digital Indicating Tester (PUNDIT). Results indicate that the pulse velocity through concrete increases with an increase in MAS. Relationships between UPV and compressive strength; and UPV and Young's modulus of concrete are proposed for different maximum sizes of brick aggregate.

  20. Pushing spatial and temporal resolution for functional and diffusion MRI in the Human Connectome Project

    PubMed Central

    Uğurbil, Kamil; Xu, Junqian; Auerbach, Edward J.; Moeller, Steen; Vu, An; Duarte-Carvajalino, Julio M.; Lenglet, Christophe; Wu, Xiaoping; Schmitter, Sebastian; Van de Moortele, Pierre Francois; Strupp, John; Sapiro, Guillermo; De Martino, Federico; Wang, Dingxin; Harel, Noam; Garwood, Michael; Chen, Liyong; Feinberg, David A.; Smith, Stephen M.; Miller, Karla L.; Sotiropoulos, Stamatios N; Jbabdi, Saad; Andersson, Jesper L; Behrens, Timothy EJ; Glasser, Matthew F.; Van Essen, David; Yacoub, Essa

    2013-01-01

    The human connectome project (HCP) relies primarily on three complementary magnetic resonance (MR) methods. These are: 1) resting state functional MR imaging (rfMRI) which uses correlations in the temporal fluctuations in an fMRI time series to deduce ‘functional connectivity’; 2) diffusion imaging (dMRI), which provides the input for tractography algorithms used for the reconstruction of the complex axonal fiber architecture; and 3) task based fMRI (tfMRI), which is employed to identify functional parcellation in the human brain in order to assist analyses of data obtained with the first two methods. We describe technical improvements and optimization of these methods as well as instrumental choices that impact speed of acquisition of fMRI and dMRI images at 3 Tesla, leading to whole brain coverage with 2 mm isotropic resolution in 0.7 second for fMRI, and 1.25 mm isotropic resolution dMRI data for tractography analysis with three-fold reduction in total data acquisition time. Ongoing technical developments and optimization for acquisition of similar data at 7 Tesla magnetic field are also presented, targeting higher resolution, specificity of functional imaging signals, mitigation of the inhomogeneous radio frequency (RF) fields and power deposition. Results demonstrate that overall, these approaches represent a significant advance in MR imaging of the human brain to investigate brain function and structure. PMID:23702417

  1. Clinical applications of CO2 lasers: clinical cases

    NASA Astrophysics Data System (ADS)

    Sinibaldi, Kenneth R.

    1994-09-01

    The most common surgery performed in our clinic with the CO2 laser is the cutting and vaporization of neoplasms associated with the head and neck, in particular, the squamous cell carcinoma in the cat. A majority of the tumors are malignant and 50% are metastatic at the time of presentation for surgery. Experience has taught us that early detection and removal with the CO2 laser affords the best prognosis. To date, roughly 100 cases have been treated with the CO2 laser. The success rate in the dog is not as rewarding as in the cat. Most cases were done with 5 - 10 watts of power continuous or pulsed wave, using a 125 mm or 50 mm handpiece. The laser beam was focused or defocused to adjust for cutting, vaporization, and coagulation. No post-op care of the wounds was recommended. Other small neoplasms in and around the ears, head, and neck can also be removed easily with the CO2 laser.

  2. Experimental investigation of the dynamic elastic modulus and vibration damping in molybdenum and alumina-coated Ti-25Al-10Nb-3V-1Mo aluminides cycled at elevated temperatures

    SciTech Connect

    Wolfenden, A.; Cantu, M.W.; Vaidya, R.U.

    1996-04-01

    Titanium aluminides such as Ti-25Al-10Nb-3V-1Mo have became the focus of high temperature materials research due to their ability to maintain their strength up to 1,000{degree}C. However, at temperatures in excess of 650{degree}C, Ti-25Al-10Nb-3V-1Mo undergoes severe oxidation which, in turn, can degrade its mechanical properties. To address this problem, plasma sprayed coatings were applied to the substrate to provide protection in the high temperature environment. In this study, 0.1-0.125 mm thick alumina and molybdenum coatings were plasma sprayed onto a Ti-25Al-10Nb-3V-1Mo substrate. Changes in dynamic elastic modulus and vibration damping due to thermal cycling at elevated temperatures were measured. The modulus and damping were measured using the piezoelectric ultrasonic composite oscillator technique (PUCOT). The behavior of the Al{sub 2}O{sub 3} and Mo coated specimens was compared to that of the uncoated samples. Thermal cycling of the coated samples at 600{degree}C led to an increase in the modulus and decrease in the damping. Most of the changes in properties occurred after the first thermal cycle. Thermal cycling of the samples at 750{degree}C and 850{degree}C led to complete failure of the coatings. A specimen with a 1.0 mm alumina coating exhibited cracks even when cycled at 600{degree}C. 7 refs., 12 figs., 3 tabs.

  3. A 4-channel 3 Tesla phased array receive coil for awake rhesus monkey fMRI and diffusion MRI experiments.

    PubMed

    Khachaturian, Mark Haig

    2010-01-01

    Awake monkey fMRI and diffusion MRI combined with conventional neuroscience techniques has the potential to study the structural and functional neural network. The majority of monkey fMRI and diffusion MRI experiments are performed with single coils which suffer from severe EPI distortions which limit resolution. By constructing phased array coils for monkey MRI studies, gains in SNR and anatomical accuracy (i.e., reduction of EPI distortions) can be achieved using parallel imaging. The major challenges associated with constructing phased array coils for monkeys are the variation in head size and space constraints. Here, we apply phased array technology to a 4-channel phased array coil capable of improving the resolution and image quality of full brain awake monkey fMRI and diffusion MRI experiments. The phased array coil is that can adapt to different rhesus monkey head sizes (ages 4-8) and fits in the limited space provided by monkey stereotactic equipment and provides SNR gains in primary visual cortex and anatomical accuracy in conjunction with parallel imaging and improves resolution in fMRI experiments by a factor of 2 (1.25 mm to 1.0 mm isotropic) and diffusion MRI experiments by a factor of 4 (1.5 mm to 0.9 mm isotropic).

  4. Performance evaluation of D-SPECT: a novel SPECT system for nuclear cardiology

    NASA Astrophysics Data System (ADS)

    Erlandsson, Kjell; Kacperski, Krzysztof; van Gramberg, Dean; Hutton, Brian F.

    2009-05-01

    D-SPECT (Spectrum Dynamics, Israel) is a novel SPECT system for cardiac perfusion studies. Based on CZT detectors, region-centric scanning, high-sensitivity collimators and resolution recovery, it offers potential advantages over conventional systems. A series of measurements were made on a β-version D-SPECT system in order to evaluate its performance in terms of energy resolution, scatter fraction, sensitivity, count rate capability and resolution. Corresponding measurements were also done on a conventional SPECT system (CS) for comparison. The energy resolution of the D-SPECT system at 140 keV was 5.5% (CS: 9.25%), the scatter fraction 30% (CS: 34%), the planar sensitivity 398 s-1 MBq-1 per head (99mTc, 10 cm) (CS: 72 s-1 MBq-1), and the tomographic sensitivity in the heart region was in the range 647-1107 s-1 MBq-1 (CS: 141 s-1 MBq-1). The count rate increased linearly with increasing activity up to 1.44 M s-1. The intrinsic resolution was equal to the pixel size, 2.46 mm (CS: 3.8 mm). The average reconstructed resolution using the standard clinical filter was 12.5 mm (CS: 13.7 mm). The D-SPECT has superior sensitivity to that of a conventional system with similar spatial resolution. It also has excellent energy resolution and count rate characteristics, which should prove useful in dynamic and dual radionuclide studies.

  5. Development of a liquid chromatographic method for the simultaneous quantification of curcumin, β-arteether, tetrahydrocurcumin and dihydroartemisinin. Application to lipid-based formulations.

    PubMed

    Memvanga, Patrick B; Mbinze, Jérémie K; Rozet, Eric; Hubert, Philippe; Préat, Véronique; Marini, Roland D

    2014-01-01

    A liquid chromatographic method was developed for the simultaneous separation of curcumin, β-arteether, tetrahydrocurcumin and dihydroartemisinin based on the design of experiments and the design space methodology. The influence of the percentage of organic modifier, flow rate of the mobile phase and column temperature on the analytes separation was investigated. The optimal chromatographic separation was achieved on a C18 column (125mm×4mm, 5μm) using an isocratic elution with a mobile phase consisting of methanol-ammonium acetate (pH 4; 10mM) (80:20, v/v) at a flow rate of 0.45ml/min and a column temperature of 32.5°C. This method was then validated for simultaneous quantification of curcumin and β-arteether contained in lipid-based formulations taking into account the β-expectation tolerance interval for the total error measurement. Finally, the suitability of the proposed liquid chromatographic method for routine analysis of curcumin and β-arteether loaded in lipid-based formulations has been proven.

  6. Gunshot injury of the foot: treatment and procedures--a role of negative pressure wound therapy.

    PubMed

    Marinović, Marin; Radović, Endi; Bakota, Bore; Mikacević, Marijan; Grzalja, Nikola; Ekl, Darko; Cepić, Ivica

    2013-04-01

    Civilian gunshot injuries of the foot are not so common in Croatia. They are related with accidents in hunting or weapon cleaning. Gunshot injuries represent a special challenge for surgeon because of specific anatomical relations and biomechanical function of the foot. We have decided to present a patient with a complex foot injury caused by hunting firearm in self-inflicted accident. A 45-year-old male presented with 12-gauge shotgun wound to his left foot. We found a complicated fracture with bone defect of 3rd, 4th and 5th metatarsals and wide soft tissue injury with skin and subcutaneous defect of the dorsal and lateral side of the foot. The wound was contaminated with numerous metal fragments, particles of rocks and ground. Surgical treatment was performed three hours after trauma and included extensive debridement of damaged soft tissue, removing of the non-viable bone and metal fragments, rocks and other foreign bodies. Negative Pressure Wound Therapy (NPWT) was applicated in the operating table. The starting therapy was continuously -125 mm Hg of vacuum. We continued with intermittent therapy of -100 mm Hg and change NPWT dressing every fourth day. After four weeks of NPWT the defect was filled with granulation tissue and split thickness skin graft was applied. Skin graft was additionally fixed with NPWT using continuous therapy at -100 mm Hg for a period of four days. Forthy days after injury there was a complete healing of all soft tissue. Control X-ray showed good bone healing process.

  7. Analysis of passivated A-286 stainless steel surfaces for mass spectrometer inlet systems by Auger electron and X-ray photoelectron spectroscopy and scanning electron microscopy

    DOE PAGES

    Ajo, Henry; Blankenship, Donnie; Clark, Elliot

    2014-07-25

    In this study, various commercially available surface treatments are being explored for use on stainless steel components in mass spectrometer inlet systems. Type A-286 stainless steel coupons, approximately 12.5 mm in diameter and 3 mm thick, were passivated with one of five different surface treatments; an untreated coupon served as a control. The surface and near-surface microstructure and chemistry of the coupons were investigated using sputter depth profiling using Auger electron spectroscopy, x-ray photoelectron spectroscopy, and scanning electron microscopy (SEM). All the surface treatments studied appeared to change the surface morphology dramatically, as evidenced by lack of tool marks onmore » the treated samples in SEM images. In terms of the passivation treatment, Vendors A-D appeared to have oxide layers that were very similar in thickness to each other (0.7–0.9 nm thick), as well as to the untreated samples (the untreated sample oxide layers appeared to be somewhat larger). Vendor E’s silicon coating appears to be on the order of 200 nm thick.« less

  8. A probabilistic atlas of the cerebellar white matter.

    PubMed

    van Baarsen, K M; Kleinnijenhuis, M; Jbabdi, S; Sotiropoulos, S N; Grotenhuis, J A; van Cappellen van Walsum, A M

    2016-01-01

    Imaging of the cerebellar cortex, deep cerebellar nuclei and their connectivity are gaining attraction, due to the important role the cerebellum plays in cognition and motor control. Atlases of the cerebellar cortex and nuclei are used to locate regions of interest in clinical and neuroscience studies. However, the white matter that connects these relay stations is of at least similar functional importance. Damage to these cerebellar white matter tracts may lead to serious language, cognitive and emotional disturbances, although the pathophysiological mechanism behind it is still debated. Differences in white matter integrity between patients and controls might shed light on structure-function correlations. A probabilistic parcellation atlas of the cerebellar white matter would help these studies by facilitating automatic segmentation of the cerebellar peduncles, the localization of lesions and the comparison of white matter integrity between patients and controls. In this work a digital three-dimensional probabilistic atlas of the cerebellar white matter is presented, based on high quality 3T, 1.25mm resolution diffusion MRI data from 90 subjects participating in the Human Connectome Project. The white matter tracts were estimated using probabilistic tractography. Results over 90 subjects were symmetrical and trajectories of superior, middle and inferior cerebellar peduncles resembled the anatomy as known from anatomical studies. This atlas will contribute to a better understanding of cerebellar white matter architecture. It may eventually aid in defining structure-function correlations in patients with cerebellar disorders.

  9. In vivo high-resolution diffusion tensor imaging of the mouse brain

    PubMed Central

    Wu, Dan; Xu, Jiadi; McMahon, Michael T.; van Zijl, Peter C.M.; Mori, Susumu; Northington, Frances, J.; Zhang, Jiangyang

    2013-01-01

    Diffusion tensor imaging (DTI) of the laboratory mouse brain provides important macroscopic information for anatomical characterization of mouse models in basic research. Currently, in vivo DTI of the mouse brain is often limited by the available resolution. In this study, we demonstrate in vivo high-resolution DTI of the mouse brain using a cryogenic probe and a modified diffusion-weighted gradient and spin echo (GRASE) imaging sequence at 11.7 Tesla. Three-dimensional (3D) DTI of the entire mouse brain at 0.125 mm isotropic resolution could be obtained in approximately two hours. The high spatial resolution, which was previously only available with ex vivo imaging, enabled non-invasive examination of small structures in the adult and neonatal mouse brains. Based on data acquired from eight adult mice, a group-averaged DTI atlas of the in vivo adult mouse brain with 60 structure segmentations was developed. Comparisons between in vivo and ex vivo mouse brain DTI data showed significant differences in brain morphology and tissue contrasts, which indicate the importance of the in vivo DTI based mouse brain atlas. PMID:23769916

  10. Role of indenter material and size in veneer failure of brittle layer structures.

    PubMed

    Bhowmick, Sanjit; Meléndez-Martínez, Juan José; Hermann, Ilja; Zhang, Yu; Lawn, Brian R

    2007-07-01

    The roles of indenter material and size in the failure of brittle veneer layers in all-ceramic crown-like structures are studied. Glass veneer layers 1 mm thick bonded to alumina layers 0.5 mm thick on polycarbonate bases (representative of porcelain/ceramic-core/dentin) are subject to cyclic contact loading with spherical indenters in water (representative of occlusal biting environment). Two indenter materials-glass and tungsten carbide-and three indenter radii-1.6, 5.0, and 12.5 mm-are investigated in the tests. A video camera is used to follow the near-contact initiation and subsequent downward propagation of cone cracks through the veneer layer to the core interface, at which point the specimen is considered to have failed. Both indenter material and indenter radius have some effect on the critical loads to initiate cracks within the local Hertzian contact field, but the influence of modulus is weaker. The critical loads to take the veneer to failure are relatively insensitive to either of these indenter variables, since the bulk of the cone crack propagation takes place in the contact far field. Clinical implications of the results are considered, including the issue of single-cycle overload versus low-load cyclic fatigue and changes in fracture mode with loading conditions.

  11. Optimization of typical diffuse herbicide pollution control by soil amendment configurations under four levels of rainfall intensities.

    PubMed

    Ouyang, Wei; Huang, Weijia; Wei, Peng; Hao, Fanghua; Yu, Yongyong

    2016-06-15

    Herbicides are a main source of agricultural diffuse pollution due to their wide application in tillage practices. The aim of this study is to optimize the control efficiency of the herbicide atrazine with the aid of modified soil amendments. The soil amendments were composed of a combination of biochar and gravel. The biochar was created from corn straw with a catalytic pyrolysis of ammonium dihydrogen phosphate. The leaching experiments under four rainfall conditions were measured for the following designs: raw soil, soil amended with gravel, biochar individually and together with gravel. The control efficiency of each design was also identified. With the designed equipment, the atrazine content in the contaminant load layer, gravel substrate layer, biochar amendment layer and soil layer was measured under four types of rainfall intensities (1.25 mm/h, 2.50 mm/h, 5.00 mm/h and 10.00 mm/h). Furthermore, the vertical distribution of atrazine in the soil sections was also monitored. The results showed that the herbicide leaching load increased under the highest rainfall intensity in all designs. The soil with the combination of gravel and biochar provided the highest control efficiency of 87.85% on atrazine when the additional proportion of biochar was 3.0%. The performance assessment under the four kinds of rainfall intensity conditions provided the guideline for the soil amendment configuration. The combination of gravel and biochar is recommended as an efficient method for controlling diffuse herbicide pollution.

  12. Wide-band, high-resolution soft x-ray spectrometer for the Electron Beam Ion Trap

    SciTech Connect

    Brown, G.V.; Beiersdorfer, P.; Widmann, K.

    1999-01-01

    We have constructed two wide-band, high-resolution vacuum flat crystal spectrometers and implemented them on the Electron Beam Ion Trap located at the Lawrence Livermore National Laboratory. Working in unison, these spectrometers can measure an x-ray bandwidth {le}9 {Angstrom} in the soft x-ray region below 21 {Angstrom}. In order to achieve this large bandwidth each spectrometer houses either two 125 mm {times} 13 mm {times} 2 mm RAP (rubidium acid phthalate, 2d=26.121 {Angstrom}), two 114 mm {times} 13 mm {times} 2 mm TlAP (thallium acid phthalate, 2d=25.75 {Angstrom}) crystals, or some combination thereof, for dispersion and two position sensitive proportional counters for detection of x rays. The spectrometers are used to measure wavelengths and relative intensities of the L-shell line emission from FethinspXVII{endash}XXIV for comparison with spectra obtained from astrophysical and laboratory plasmas. The wide wavelength coverage attainable by these spectrometers makes it possible to measure all the L-shell emission from a given iron ion species simultaneously. {copyright} {ital 1999 American Institute of Physics.}

  13. Attenuated total internal reflection infrared microspectroscopic imaging using a large-radius germanium internal reflection element and a linear array detector.

    PubMed

    Patterson, Brian M; Havrilla, George J

    2006-11-01

    The number of techniques and instruments available for Fourier transform infrared (FT-IR) microspectroscopic imaging has grown significantly over the past few years. Attenuated total internal reflectance (ATR) FT-IR microspectroscopy reduces sample preparation time and has simplified the analysis of many difficult samples. FT-IR imaging has become a powerful analytical tool using either a focal plane array or a linear array detector, especially when coupled with a chemometric analysis package. The field of view of the ATR-IR microspectroscopic imaging area can be greatly increased from 300 x 300 microm to 2500 x 2500 microm using a larger internal reflection element of 12.5 mm radius instead of the typical 1.5 mm radius. This gives an area increase of 70x before aberrant effects become too great. Parameters evaluated include the change in penetration depth as a function of beam displacement, measurements of the active area, magnification factor, and change in spatial resolution over the imaging area. Drawbacks such as large file size will also be discussed. This technique has been successfully applied to the FT-IR imaging of polydimethylsiloxane foam cross-sections, latent human fingerprints, and a model inorganic mixture, which demonstrates the usefulness of the method for pharmaceuticals.

  14. Effect of the Ti/N ratio on the hardenability and mechanical properties of a quenched-and-tempered C-Mn-B steel

    SciTech Connect

    Shen, Y.; Hansen, S.S.

    1997-10-01

    Ten experimental 0.18 pct C-1.2 pct Mn-0.002 pct B steels with various Ti/N ratios were evaluated in this study. The hardenability of these steels was first determined using Jominy tests. Slab sections were then rolled to produce 12.5-mm-thick plates, and subsequently quenched and tempered for mechanical property evaluation. The volume fraction of coarse (greater than 1 {micro}m) TiN particles was measured in all steels using quantitative metallographic techniques. Scanning transmission electron microscopy was used to investigate fine precipitates, and scanning electron microscopy was used to examine the fracture surface of Charpy specimens. The results show that a complete boron (B) hardenability effect is obtained with Ti/N ratios {ge} 2.9, a value slightly below the stoichiometric Ti/N ratio of 3.4. Any excess Ti, above that which combines with N, provides an additional increase in hardenability on quenching (effect of Ti in solution) and an increase in strength on tempering (Ti (C,N) precipitation). Steels with a higher (Ti)(N) product develop a higher volume fraction of coarse TiN particles during solidification. These coarse TiN particles result in reduced toughness levels of the heat-treated plates evaluated in the present study.

  15. Reproducibility of radiomics for deciphering tumor phenotype with imaging.

    PubMed

    Zhao, Binsheng; Tan, Yongqiang; Tsai, Wei-Yann; Qi, Jing; Xie, Chuanmiao; Lu, Lin; Schwartz, Lawrence H

    2016-03-24

    Radiomics (radiogenomics) characterizes tumor phenotypes based on quantitative image features derived from routine radiologic imaging to improve cancer diagnosis, prognosis, prediction and response to therapy. Although radiomic features must be reproducible to qualify as biomarkers for clinical care, little is known about how routine imaging acquisition techniques/parameters affect reproducibility. To begin to fill this knowledge gap, we assessed the reproducibility of a comprehensive, commonly-used set of radiomic features using a unique, same-day repeat computed tomography data set from lung cancer patients. Each scan was reconstructed at 6 imaging settings, varying slice thicknesses (1.25 mm, 2.5 mm and 5 mm) and reconstruction algorithms (sharp, smooth). Reproducibility was assessed using the repeat scans reconstructed at identical imaging setting (6 settings in total). In separate analyses, we explored differences in radiomic features due to different imaging parameters by assessing the agreement of these radiomic features extracted from the repeat scans reconstructed at the same slice thickness but different algorithms (3 settings in total). Our data suggest that radiomic features are reproducible over a wide range of imaging settings. However, smooth and sharp reconstruction algorithms should not be used interchangeably. These findings will raise awareness of the importance of properly setting imaging acquisition parameters in radiomics/radiogenomics research.

  16. Amperometric Sensor for Detection of Chloride Ions†

    PubMed Central

    Trnkova, Libuse; Adam, Vojtech; Hubalek, Jaromir; Babula, Petr; Kizek, Rene

    2008-01-01

    Chloride ion sensing is important in many fields such as clinical diagnosis, environmental monitoring and industrial applications. We have measured chloride ions at a carbon paste electrode (CPE) and at a CPE modified with solid AgNO3, a solution of AgNO3 and/or solid silver particles. Detection limits (3 S/N) for chloride ions were 100 μM, 100 μM and 10 μM for solid AgNO3, solution of AgNO3 and/or solid silver particles, respectively. The CPE modified with silver particles is the most sensitive to the presence chloride ions. After that we approached to the miniaturization of the whole electrochemical instrument. Measurements were carried out on miniaturized instrument consisting of a potentiostat with dimensions 35 × 166 × 125 mm, screen printed electrodes, a peristaltic pump and a PC with control software. Under the most suitable experimental conditions (Britton-Robinson buffer, pH 1.8 and working electrode potential 550 mV) we estimated the limit of detection (3 S/N) as 500 nM. PMID:27873832

  17. A converging route towards very high frequency, mechanically flexible, and performance stable integrated electronics

    NASA Astrophysics Data System (ADS)

    Lecavelier des Etangs-Levallois, Aurélien; Chen, Zhenkun; Lesecq, Marie; Lepilliet, Sylvie; Tagro, Yoann; Danneville, François; Robillard, Jean-François; Hoel, Virginie; Troadec, David; Gloria, Daniel; Raynaud, Christine; Ratajczak, Jacek; Dubois, Emmanuel

    2013-04-01

    The ability to realize flexible circuits integrating sensing, signal processing, and communicating capabilities is of central importance for the development of numerous nomadic applications requiring foldable, stretchable, and large area electronics. A key challenge is, however, to combine high electrical performance (i.e., millimeter wave, low noise electronics) with mechanical flexibility required for chip form adaptivity in addition to highly stable electrical performance upon deformation. Here, we describe a solution based on ultimate thinning and transfer onto a plastic foil of high frequency CMOS devices initially processed on conventional silicon-on-insulator wafers. We demonstrate a methodology relying on neutral plane engineering to provide high performance stability upon bending, by locating the active layer, i.e., the transistor channel, at the neutral fiber of the flexible system. Following this strategy, record frequency performance of flexible n-MOSFETs, featuring fT/fMAX of 120/145 GHz, is reported with relative variations limited to less than 5% even under aggressive bending on cylinders with curvature radii down to 12.5 mm.

  18. Optimizing probe design for an implantable perfusion and oxygenation sensor

    SciTech Connect

    Akl, Tony; Long, Ruiqi; McShane, Michael J.; Ericson, Milton Nance; Wilson, Mark A.; Cote, Gerard L.

    2011-01-01

    In an effort to develop an implantable optical perfusion and oxygenation sensor, based on multiwavelength reflectance pulse oximetry, we investigate the effect of source detector separation and other source-detector characteristics to optimize the sensor s signal to background ratio using Monte Carlo (MC) based simulations and in vitro phantom studies. Separations in the range 0.45 to 1.25 mm were found to be optimal in the case of a point source. The numerical aperture (NA) of the source had no effect on the collected signal while the widening of the source spatial profile caused a shift in the optimal source-detector separation. Specifically, for a 4.5 mm flat beam and a 2.4 mm 2.5 mm photodetector, the optimal performance was found to be when the source and detector are adjacent to each other. These modeling results were confirmed by data collected from in vitro experiments on a liver phantom perfused with dye solutions mimicking the absorption properties of hemoglobin for different oxygenation states.

  19. Linear Dimensional Stability of Irreversible Hydrocolloid Materials Over Time.

    PubMed

    Garrofé, Analía B; Ferrari, Beatriz A; Picca, Mariana; Kaplan, Andrea E

    2015-12-01

    The aim of this study was to evaluate the linear dimensional stability of different irreversible hydrocolloid materials over time. A metal mold was designed with custom trays made of thermoplastic sheets (Sabilex, sheets 0.125 mm thick). Perforations were made in order to improve retention of the material. Five impressions were taken with each of the following: Kromopan 100 (LASCOD) [AlKr], which has dimensional stability of 100 hours, and Phase Plus (ZHERMACK) [AlPh], which has dimensional stability of 48 hours. Standardized digital photographs were taken at different time intervals (0, 15, 30, 45, 60, 120 minutes; 12, 24 and 96 hours), using an "ad-hoc" device. The images were analyzed with software (UTHSCSA Image Tool) by measuring the distance between intersection of the lines previously made at the top of the mold. The results were analyzed by ANOVA for repeated measures. Initial and final values were (mean and standard deviation): AlKr: 16.44 (0.22) and 16.34 (0.11), AlPh: 16.40 (0.06) and 16.18 (0.06). Statistical evaluation showed significant effect of material and time factors. Under the conditions in this study, time significantly affects the linear dimensional stability of irreversible hydrocolloid materials.

  20. Mechanisms and clinical applications of the vacuum-assisted closure (VAC) Device: a review.

    PubMed

    Venturi, Mark L; Attinger, Christopher E; Mesbahi, Ali N; Hess, Christopher L; Graw, Katherine S

    2005-01-01

    The use of sub-atmospheric pressure dressings, available commercially as the vacuum-assisted closure (VAC) device, has been shown to be an effective way to accelerate healing of various wounds. The optimal sub-atmospheric pressure for wound healing appears to be approximately 125 mm Hg utilizing an alternating pressure cycle of 5 minutes of suction followed by 2 minutes off suction. Animal studies have demonstrated that this technique optimizes blood flow, decreases local tissue edema, and removes excessive fluid from the wound bed. These physiologic changes facilitate the removal of bacteria from the wound. Additionally, the cyclical application of sub-atmospheric pressure alters the cytoskeleton of the cells in the wound bed, triggering a cascade of intracellular signals that increases the rate of cell division and subsequent formation of granulation tissue. The combination of these mechanisms makes the VAC device an extremely versatile tool in the armamentarium of wound healing. This is evident in the VAC device's wide range of clinical applications, including treatment of infected surgical wounds, traumatic wounds, pressure ulcers, wounds with exposed bone and hardware, diabetic foot ulcers, and venous stasis ulcers. VAC has also proven useful in reconstruction of wounds by allowing elective planning of the definitive reconstructive surgery without jeopardizing the wound or outcome. Furthermore, VAC has significantly increased the skin graft success rate when used as a bolster over the freshly skin-grafted wound. VAC is generally well tolerated and, with few contraindications or complications, is fast becoming a mainstay of current wound care.

  1. Prediction of the mid-tracheal level using surface anatomical landmarks in adults

    PubMed Central

    Jang, Young-Eun; Kim, Eun-Hee; Song, In-Kyung; Lee, Ji-Hyun; Ryu, Ho-Geoul; Kim, Hee-Soo; Kim, Jin-Tae

    2017-01-01

    Abstract Endotracheal tube (ETT) should be placed at the optimal level to avoid single lung ventilation or accidental extubation. This study was performed to estimate the mid-tracheal level by using surface anatomical landmarks in adult patients. Neck computed tomography images of 329 adult patients between the ages of 16 and 79 years were reviewed. In the midline sagittal plane, the levels corresponding to the vocal cords, cricoid cartilage, suprasternal notch, manubriosternal junction, and carina were identified. The surface distances from the cricoid cartilage to the suprasternal notch (extCC-SSN) and that from the suprasternal notch to the manubriosternal junction (extSSN-MSJ) were measured. The relationship between mid-tracheal level and the surface distances was analyzed using Bland–Altman plot. The difference between the extCC-SSN and the mid-tracheal level was −6.6 (12.5) mm, and the difference between the extSSN-MSJ and the mid-tracheal level was −19.2 (6.1) mm. The difference between the extCC-SSN and the mid-tracheal level was smaller in females compared with males [−1.7 (11.7) mm vs −12.8 (10.7) mm; P < 0.001]. The mid-tracheal level, which is helpful in planning the insertion depth of an ETT, can be predicted by the surface distance between the cricoid cartilage and suprasternal notch in adults, especially in females. PMID:28328810

  2. Quarry blasts assessment and their environmental impacts on the nearby oil pipelines, southeast of Helwan City, Egypt

    NASA Astrophysics Data System (ADS)

    Mohamed, Adel M. E.; Mohamed, Abuo El-Ela A.

    2013-06-01

    Ground vibrations induced by blasting in the cement quarries are one of the fundamental problems in the quarrying industry and may cause severe damage to the nearby utilities and pipelines. Therefore, a vibration control study plays an important role in the minimization of environmental effects of blasting in quarries. The current paper presents the influence of the quarry blasts at the National Cement Company (NCC) on the two oil pipelines of SUMED Company southeast of Helwan City, by measuring the ground vibrations in terms of Peak Particle Velocity (PPV). The seismic refraction for compressional waves deduced from the shallow seismic survey and the shear wave velocity obtained from the Multi channel Analysis of Surface Waves (MASW) technique are used to evaluate the closest site of the two pipelines to the quarry blasts. The results demonstrate that, the closest site of the two pipelines is of class B, according to the National Earthquake Hazard Reduction Program (NEHRP) classification and the safe distance to avoid any environmental effects is 650 m, following the deduced Peak Particle Velocity (PPV) and scaled distance (SD) relationship (PPV = 700.08 × SD-1.225) in mm/s and the Air over Pressure (air blast) formula (air blast = 170.23 × SD-0.071) in dB. In the light of prediction analysis, the maximum allowable charge weight per delay was found to be 591 kg with damage criterion of 12.5 mm/s at the closest site of the SUMED pipelines.

  3. Computational micromechanical analysis of the representative volume element of bituminous composite materials

    NASA Astrophysics Data System (ADS)

    Ozer, Hasan; Ghauch, Ziad G.; Dhasmana, Heena; Al-Qadi, Imad L.

    2016-08-01

    Micromechanical computational modeling is used in this study to determine the smallest domain, or Representative Volume Element (RVE), that can be used to characterize the effective properties of composite materials such as Asphalt Concrete (AC). Computational Finite Element (FE) micromechanical modeling was coupled with digital image analysis of surface scans of AC specimens. Three mixtures with varying Nominal Maximum Aggregate Size (NMAS) of 4.75 mm, 12.5 mm, and 25 mm, were prepared for digital image analysis and computational micromechanical modeling. The effects of window size and phase modulus mismatch on the apparent viscoelastic response of the composite were numerically examined. A good agreement was observed in the RVE size predictions based on micromechanical computational modeling and image analysis. Micromechanical results indicated that a degradation in the matrix stiffness increases the corresponding RVE size. Statistical homogeneity was observed for window sizes equal to two to three times the NMAS. A model was presented for relating the degree of statistical homogeneity associated with each window size for materials with varying inclusion dimensions.

  4. Methanol Droplet Extinction in Carbon-Dioxide-Enriched Environments in Microgravity

    NASA Technical Reports Server (NTRS)

    Hicks, Michael C.; Nayagam, Vedha; Williams, Forman A.

    2010-01-01

    Diffusive extinction of methanol droplets with initial diameters between 1.25 mm and 1.72 mm, burning in a quiescent microgravity environment at one atmosphere pressure, was obtained experimentally for varying levels of ambient carbon-dioxide concentrations with a fixed oxygen concentration of 21% and a balance of nitrogen. These experiments serve as precursors to those which are beginning to be performed on the International Space Station and are motivated by the need to understand the effectiveness of carbon-dioxide as a fire suppressant in low-gravity environments. In these experiments, the flame standoff distance, droplet diameter, and flame radiation are measured as functions of time. The results show that the droplet extinction diameter depends on both the initial droplet diameter and the ambient concentration of carbon dioxide. Increasing the initial droplet diameter leads to an increased extinction diameter, while increasing the carbon-dioxide concentration leads to a slight decrease in the extinction diameter. These results are interpreted using a critical Damk hler number for extinction as predicted by an earlier theory, which is extended here to be applicable in the presence of effects of heat conduction along the droplet support fibers and of the volume occupied by the support beads

  5. Electro-Mechanical Simulation of a Large Aperture MOEMS Fabry-Perot Tunable Filter

    NASA Technical Reports Server (NTRS)

    Kuhn, Jonathan L.; Barclay, Richard B.; Greenhouse, Matthew A.; Mott, D. Brent; Satyapal, Shobita; Powers, Edward I. (Technical Monitor)

    2000-01-01

    We are developing a micro-machined electrostatically actuated Fabry-Perot tunable filter with a large clear aperture for application in high through-put wide-field imaging spectroscopy and lidar systems. In the first phase of this effort, we are developing key components based on coupled electro-mechanical simulations. In particular, the movable etalon plate design leverages high coating stresses to yield a flat surface in drum-head tension over a large diameter (12.5 mm). In this approach, the cylindrical silicon movable plate is back etched, resulting in an optically coated membrane that is suspended from a thick silicon support ring. Understanding the interaction between the support ring, suspended membrane, and coating is critical to developing surfaces that are flat to within stringent etalon requirements. In this work, we present the simulations used to develop the movable plate, spring suspension system, and electrostatic actuation mechanism. We also present results from tests of fabricated proof of concept components.

  6. Hard-X and gamma-ray imaging detector for astrophysics based on pixelated CdTe semiconductors

    NASA Astrophysics Data System (ADS)

    Gálvez, J.-L.; Hernanz, M.; Álvarez, L.; Artigues, B.; Ullán, M.; Lozano, M.; Pellegrini, G.; Cabruja, E.; Martínez, R.; Chmeissani, M.; Puigdengoles, C.

    2016-01-01

    Stellar explosions are astrophysical phenomena of great importance and interest. Instruments with high sensitivities are essential to perform detailed studies of cosmic explosions and cosmic accelerators. In order to achieve the needed performance, a hard-X and gamma-ray imaging detector with mm spatial resolution and large enough efficiency is required. We present a detector module which consists of a single CdTe crystal of 12.5 × 12.5mm 2 and 2mm thick with a planar cathode and with the anode segmented in an 11x11 pixel array with a pixel pitch of 1 mm attached to the readout chip. Two possible detector module configurations are considered: the so-called Planar Transverse Field (PTF) and the Parallel Planar Field (PPF). The combination of several modules in PTF or PPF configuration will achieve the desired performance of the imaging detector. The sum energy resolution of all pixels of the CdTe module measured at 122 keV and 356 keV is 3.8% and 2% respectively, in the following operating conditions: PPF irradiation, bias voltage -500 V and temperature -10̂ C.

  7. Strong upstream flow characteristics in the formation of rivulets

    NASA Astrophysics Data System (ADS)

    Lye, Jonathan Kok Keung; Neild, Adrian; Ng, Tuck Wah

    2011-02-01

    In a fully formed rivulet, the flow profile across the total cross section is downward, as would be intuitively expected. However, prior to this stage being reached, a strong backflow capable of carrying particles up to 125 mm up the incline back to the source is shown to occur. Two phases are described prior to a fully formed rivulet being established. First, a forming rivulet, in which a bulbous drop head slides down a slope with a flow occurring in the wetted trail behind it. In this stage, a linear increase in backflow height is observed over time. Subsequently, a transient rivulet occurs, with the transition happening once the end of the inclined solid surface is reached. The backflow decreases through this phase in a stepwise manner, coinciding with fluid dripping off the surface. The findings here strongly challenge common assumptions made regarding cleaning, whereby fluid will transport particulate matter downhill, and has significant implications on irrigation applied to remove bacterial biofilms in clinical medicine.

  8. A field study of virus removal in septic tank drainfields.

    PubMed

    Nicosia, L A; Rose, J B; Stark, L; Stewart, M T

    2001-01-01

    Two field studies were conducted at a research station in Tampa, Florida to assess the removal of bacteriophage PRD1 from wastewater in septic tank drainfields. Infiltration cells were seeded with PRD1 and bromide and the effects of effluent hydraulic loading rate and rainfall on virus removal were monitored. Septic tank effluent samples were collected after passage through 0.6 m of unsaturated fine sand and PRD1 was detected over an average of 67 d. Bacteriophage PRD1 breakthrough was detected at approximately the same time as bromide in all three cells except for the low-load cell (Study 1), where bromide was never detected. Log10 removals of PRD1 were 1.43 and 1.91 for the high-load cells (hydraulic loading rate = 0.063 m/d) and 2.21 for the low-load cell (hydraulic loading rate = 0.032 m/d). Virus attenuation is attributed to dispersion, dilution, and inactivation. Significant increases in PRD1 elution with rainfall were observed in the first 10 d of the study. Approximately 125 mm of rainfall caused a 1.2 log10 increase of PRD1 detected at the 0.6-m depth. Current Florida onsite wastewater disposal standards, which specify a 0.6-m distance from the drainfield to the water table, may not provide sufficient removal of viruses, particularly during the wet season.

  9. The Solanum lycopersicum Zinc Finger2 cysteine-2/histidine-2 repressor-like transcription factor regulates development and tolerance to salinity in tomato and Arabidopsis.

    PubMed

    Hichri, Imène; Muhovski, Yordan; Žižkova, Eva; Dobrev, Petre I; Franco-Zorrilla, Jose Manuel; Solano, Roberto; Lopez-Vidriero, Irene; Motyka, Vaclav; Lutts, Stanley

    2014-04-01

    The zinc finger superfamily includes transcription factors that regulate multiple aspects of plant development and were recently shown to regulate abiotic stress tolerance. Cultivated tomato (Solanum lycopersicum Zinc Finger2 [SIZF2]) is a cysteine-2/histidine-2-type zinc finger transcription factor bearing an ERF-associated amphiphilic repression domain and binding to the ACGTCAGTG sequence containing two AGT core motifs. SlZF2 is ubiquitously expressed during plant development, and is rapidly induced by sodium chloride, drought, and potassium chloride treatments. Its ectopic expression in Arabidopsis (Arabidopsis thaliana) and tomato impaired development and influenced leaf and flower shape, while causing a general stress visible by anthocyanin and malonyldialdehyde accumulation. SlZF2 enhanced salt sensitivity in Arabidopsis, whereas SlZF2 delayed senescence and improved tomato salt tolerance, particularly by maintaining photosynthesis and increasing polyamine biosynthesis, in salt-treated hydroponic cultures (125 mm sodium chloride, 20 d). SlZF2 may be involved in abscisic acid (ABA) biosynthesis/signaling, because SlZF2 is rapidly induced by ABA treatment and 35S::SlZF2 tomatoes accumulate more ABA than wild-type plants. Transcriptome analysis of 35S::SlZF2 revealed that SlZF2 both increased and reduced expression of a comparable number of genes involved in various physiological processes such as photosynthesis, polyamine biosynthesis, and hormone (notably ABA) biosynthesis/signaling. Involvement of these different metabolic pathways in salt stress tolerance is discussed.

  10. Low cost corrosion damage mitigation and improved fatigue performance of low plasticity burnished 7075-T6

    NASA Astrophysics Data System (ADS)

    Prevéy, Paul S.; Cammett, John

    2001-10-01

    Low plasticity burnishing (LPB) has been investigated as a surface enhancement process and corrosion mitigation method for aging aircraft structural applications. Compressive residual stresses reaching the alloy yield strength and extending to a depth of 1.25 mm (0.050 in.) deeper than typical corrosion damage is achievable. Excellent surface finish can be achieved with no detectable metallurgical damage to surface and subsurface material. Salt fog exposures of 100 and 500 h reduced the fatigue strength at 2×106 cycles by 50%. The LPB of the corroded surface, without removal of the corrosion product or pitted material, restored the 2×106 fatigue strength to greater than that of the original machined surface. The fatigue strength of the corroded material in the finite life regime (104 to 106 cycles) after LPB was 140 MPa (20 ksi) higher than the original uncorroded alloy and increased the life by an order of magnitude. Ease of adaptation to computer numerical control (CNC) machine tools allows LPB processing at costs and speeds comparable to machining operations. Low plasticity burnishing offers a promising new technology for mitigation of corrosion damage and improved fatigue life of aircraft structural components with significant cost and time savings over current practices.

  11. Haptic Perception of Edge Sharpness in Real and Virtual Environments.

    PubMed

    Park, Jaeyoung; Provancher, William; Tan, Hong Z

    2016-09-21

    We investigate the accuracy with which the haptic sharpness perception of a virtual edge is matched to that of a real edge and the effect of the virtual surface stiffness on the match. The perceived sharpness of virtual edges was estimated in terms of the point of subjective equality (PSE) when participants matched the sharpness of virtual edges to that of real edges with a radius of 0.5, 2.5 and 12.5 mm over a virtual stiffness range of 0.6 to 3.0 N/mm. The perceived sharpness of a real and a virtual edge of the same radius was significantly different under all but one of the experimental conditions and there was a significant effect of virtual surface stiffness on the accuracy of the match. The results suggest that the latter is presumably due to a constant penetration force employed by the participants that influenced the penetration depth and perceived sharpness of virtual edges at different surface stiffness levels. Our findings provide quantitative relations for appropriately offsetting the radii of virtual edges in order to achieve the desired perceived sharpness of virtual edges.

  12. A new rigid biodegradable anchor for meniscus refixation: biomechanical evaluation.

    PubMed

    Zantop, Thore; Eggers, Anne Kathleen; Musahl, Volker; Weimann, Andre; Hassenpflug, Joachim; Petersen, Wolf

    2004-07-01

    All-inside repair devices have been developed to overcome the disadvantages of conventional suture techniques (such as vein and nerve damage and increased OR time). The Contour Meniscus Arrow is a second generation of the first biodegradable all-inside implant, the Meniscus Arrow. The aim of this study was to compare the biomechanical properties of the Contour Meniscus Arrow to the first-generation Meniscus Arrow and vertical or horizontal suture techniques. In fresh frozen bovine menisci, initial fixation strength, stiffness and failure mode of four different meniscus refixation techniques (Meniscus Arrow, Contour Meniscus Arrow, vertical and horizontal 2-0 Ethibond suture techniques) were evaluated in a computer-based material-testing machine at a rate of 12.5 mm/s. Vertical meniscus sutures showed the highest initial fixation strength, followed by the horizontal suture technique and the Contour Arrow. The Meniscus Arrow showed inferior pull-out strength. Subjecting the different refixation techniques to cyclic testing decreased the fixation strength in all groups. The modified Meniscus Anchor (Contour Arrow) provides biomechanical properties that are superior (pull-out strength) or similar (stiffness) compared to the first biodegradable all-inside implant, the Meniscus Arrow. The pull-out strength of the Contour Arrow was comparable to the pull-out strength reported for horizontal meniscus sutures in the literature. These biomechanical characteristics of this new implant justify clinical use.

  13. Debris cloud characterization at impact velocities of 5 to 11 km/s

    SciTech Connect

    Chhabildas, L.C.; Boslough, M.B.; Reinhart, W.D.; Hall, C.A.

    1993-08-01

    A series of experiments has been performed on the Sandia HyperVelocity Launcher to impact a 1.25-mm thick aluminum bumper by an aluminum flier plate 17-mm diameter by 0.92-mm thick over the velocity range of 5 km/s to 11 km/s. Radiographic techniques were employed to record the debris cloud generated upon impact. The shape of the debris cloud is found to depend on the flier plate tilt. Generally -- the data indicate a central core of higher density surrounded by a diffused layer. These experiments allow measurements of debris cloud expansion velocities as the material undergoes a phase change from solid fragments at impact velocities of 5 km/s to a mixture of liquid and vapor phase at higher impact velocities. The expansion velocity of the debris cloud increases with increasing impact velocity, with the high-density leading edge traveling faster than the impact velocity. There is a difference between the X-ray and photographic measurements of expansion velocities at higher impact velocities. This is believed to be due to the presence of very low-density vapor in the photographic records that are not detecting using X-ray techniques.

  14. The evaluation of smaller plasterboards on productivity, work demands and workload in construction workers.

    PubMed

    van der Molen, Henk F; Mol, Eric; Kuijer, P Paul F M; Frings-Dresen, Monique H W

    2007-09-01

    Manual handling of plasterboards in order to construct interior building walls is a risk factor for musculoskeletal complaints. Unfortunately, mechanical lifting aids to reduce the physical workload are impractical for this task. Therefore, the effect of smaller plasterboards on productivity, work demands and workload was evaluated in an exploratory study among experienced construction workers (n=4-8) at the worksite. The dimensions and weight of the conventional and smaller plasterboards (PB) were: PB120 (2440 x 1200 x 15 mm; 33 kg) and PB90 (2440 x 900 x 12.5 mm; 20 kg), respectively. Productivity was defined as meters of plasterboard mounted. Work demands were assessed by means of real time observations of tasks and activities. Workload was determined using continuous heart rate monitoring and subjective judgments of perceived workload. Productivity and total work time per working day did not differ between PB120 and PB90. Duration of mounting (29% increase) and anchoring (26% increase) were longer for PB90 than PB120. Duration of lifting, carrying and turning over plasterboards, and percentage of heart rate reserve showed no difference between PB120 and PB90. A majority of the workers preferred PB90. For the last two reasons and because PB90 weighs approximately 40% less than PB120, PB90 seems preferable. The workload in both conditions, however, was considered high.

  15. [Arterial vascularization of the triceps sural muscle].

    PubMed

    Mairesse, J L; Mestdagh, H; Procyk, S; Depreux, R

    1984-01-01

    The triceps surae muscle, the dorsal and medial leg skin constitute a very important reserve of muscular and myocutaneous flaps. The material on which the study was carried out consisted of 20 legs from standard cadavers. The superficialis femoral artery was injected with terebenthene and minimum mixture. The medial head of gastrocnemius is 23.3 em long, 6.9 cm wide, 1.25 mm thick at distal third. Its dominant blood supply is carried by the medialis gastrocnemius artery. It rises from popliteal artery 1.2 cm above the femoral tibial articulation with 1.9 mm diameter. It runs 3 cm down before entering muscle where it provides 2 or 3 mean branches. These branches give musculocutaneous arteries to the skin of the dorsal leg. The same study was performed for the lateral head of gastrocnemius and soleus. We studied also arteries of dorsomedial leg skin. The characteristics of long saphenous and short saphenous arteries were described. These muscles and dorsomedial leg skin can be used as muscular or myocutaneous flap for covering defects between the lower leg and the lower thigh.

  16. Liberation characteristic and physical separation of printed circuit board (PCB).

    PubMed

    Guo, Chao; Wang, Hui; Liang, Wei; Fu, Jiangang; Yi, Xin

    2011-01-01

    Recycling of printed circuit board (PCB) is an important subject and to which increasing attention is paid, both in treatment of waste as well as recovery of valuable material terms. Precede physical and mechanical method, a good liberation is the premise to further separation. In this study, two-step crushing process is employed, and standard sieve is applied to screen crushed material to different size fractions, moreover, the liberation situation and particles shape in different size are observed. Then metal of the PCB is separated by physical methods, including pneumatic separation, electrostatic separation and magnetic separation, and major metal contents are characterized by inductively coupled plasma emission spectrometry (ICP-AES). Results show that the metal and nonmetal particles of PCB are dissociated completely under the crush size 0.6mm; metal is mainly enriched in the four size fractions between 0.15 and 1.25 mm; relatively, pneumatic separation is suitable for 0.6-0.9 mm size fraction, while the electrostatic separation is suitable for three size fractions that are 0.15-0.3mm, 0.3-0.6mm and 0.9-1.25 mm. The whole process that involves crushing, electrostatic and magnetic separation has formed a closed cycle that can return material and provide salable product.

  17. A Mathematical Model of Oxygen Transport in Skeletal Muscle During Hindlimb Unloading

    NASA Technical Reports Server (NTRS)

    Causey, Laura; Lewandowski, Beth E.; Weinbaum, Sheldon

    2014-01-01

    During hindlimb unloading (HU) dramatic fluid shifts occur within minutes of the suspension, leading to a less precise matching of blood flow to O2 demands of skeletal muscle. Vascular resistance directs blood away from certain muscles, such as the soleus (SOL). The muscle volume gradually reduces in these muscles so that eventually the relative blood flow returns to normal. It is generally believed that muscle volume change is not due to O2 depletion, but a consequence of disuse. However, the volume of the unloaded rat muscle declines over the course of weeks, whereas the redistribution of blood flow occurs immediately. Using a Krogh Cylinder Model, the distribution of O2 was predicted in two skeletal muscles: SOL and gastrocnemius (GAS). Effects of the muscle blood flow, volume, capillary density, and O2 uptake, are included to calculate the pO2 at rest and after 10 min and 15 days of unloading. The model predicts that 32 percent of the SOL muscle tissue has a pO2 1.25 mm Hg within 10 min, whereas the GAS maintains normal O2 levels, and that equilibrium is reached only as the SOL muscle cells degenerate. The results provide evidence that there is an inadequate O2 supply to the mitochondria in the SOL muscle after 10 min HU.

  18. Simplified stereo-optical ultrasound plane calibration

    NASA Astrophysics Data System (ADS)

    Hoßbach, Martin; Noll, Matthias; Wesarg, Stefan

    2013-03-01

    Image guided therapy is a natural concept and commonly used in medicine. In anesthesia, a common task is the injection of an anesthetic close to a nerve under freehand ultrasound guidance. Several guidance systems exist using electromagnetic tracking of the ultrasound probe as well as the needle, providing the physician with a precise projection of the needle into the ultrasound image. This, however, requires additional expensive devices. We suggest using optical tracking with miniature cameras attached to a 2D ultrasound probe to achieve a higher acceptance among physicians. The purpose of this paper is to present an intuitive method to calibrate freehand ultrasound needle guidance systems employing a rigid stereo camera system. State of the art methods are based on a complex series of error prone coordinate system transformations which makes them susceptible to error accumulation. By reducing the amount of calibration steps to a single calibration procedure we provide a calibration method that is equivalent, yet not prone to error accumulation. It requires a linear calibration object and is validated on three datasets utilizing di erent calibration objects: a 6mm metal bar and a 1:25mm biopsy needle were used for experiments. Compared to existing calibration methods for freehand ultrasound needle guidance systems, we are able to achieve higher accuracy results while additionally reducing the overall calibration complexity. Ke

  19. A micromachined angular-acceleration sensor for geophysical applications

    NASA Astrophysics Data System (ADS)

    Liu, Huafeng; Pike, W. T.

    2016-10-01

    This paper presents an angular-acceleration sensor that works as either an angular accelerometer or a gravity gradiometer and is based on the micro electromechanical system (MEMS) technology. The changes in the angle of the sensor mass are sensed by a rotational capacitive array transducer that is formed by electrodes on both the stator and rotor dies of the flip-chip-bonded MEMS chip (21 mm × 12.5 mm × 1 mm). The prototype was characterized, demonstrating a fundamental frequency of 27 Hz, a quality factor of 230 in air, and a sensitivity of 6 mV/(rad/s2). The demonstrated noise floor was less than 0.003 rad/s2/ √{ Hz } within a bandwidth of 0.1 Hz to 10 Hz, which is comparable with the conventional angular accelerometer and is better than the other reported MEMS sensors in low-frequency ranges. The features of small size and low cost suggest that this MEMS angular-acceleration sensor could be mounted on a drone, a satellite or even a Mars rover, and it is promising to be used for monitoring angular accelerations, aiding seismic recording, mapping gravity anomalies, and other geophysical applications for large-scale terrestrial and space deployments.

  20. Treatment of gingival recession using enamel matrix proteins: a case report with 4-year follow-up.

    PubMed

    Kuru, Bahar; Yilmaz, Selçuk; Noyan, Ulkü

    2007-05-01

    Obtaining predictable and optimal coverage of exposed root surfaces and correction of corresponding gingival recessions have become important goals of periodontal plastic surgery. Various surgical techniques have been proposed for coverage of root surfaces. A therapeutic advantage may be gained if periodontal regeneration is obtained in addition to coverage of root with gingiva. In this case report, surgical recession coverage was performed as the bilaterally pedicled lateral sliding flap technique with the adjunctive use of enamel matrix derivative bioactive material (Emdogain). A female patient with gingival recession on maxillary central incisors is presented with 4-year follow-up observation. The surgical procedure used in this clinical pilot case study produced a marked reduction in gingival recession that was maintained for 4 years. Initial gingival recession averaged 4.25 mm with a probing depth of 1.25 mm. The 4-year follow-up demonstrated no significant changes in the degree of postoperative results obtained after 1 year. At the 4-year follow-up, a mean of 3.75 mm of root coverage was observed (93.8% root coverage). Probing depth averaged 0.75 mm, indicating a total of 4.25 mm gain of clinical attachment. Within the limits of this case, the results demonstrated the possibility of treating human buccal recessions by means of enamel matrix protein derivative together with the laterally repositioned flap technique, with a predictable reduction in recession and clinical gain in attachment.

  1. Amorphous Ti-Zr; Base Metglas brazing filler metals

    SciTech Connect

    Rabinkin, A.; Liebermann, H.; Pounds, S.; Taylor, T. )

    1991-01-01

    This paper is the first report on processing, properties and potential application of amorphous titanium/zirconium-base alloys produced in the form of a good quality continuous and ductile ribbon having up to 12.5 mm width. To date, the majority of titanium brazing is accomplished using cooper and aluminum-base brazing filler metals. The brazements produced with these filler metals have rather low ({approximately}300{degrees} C) service temperature, thus impeding progress in aircraft and other technologies and industries. The attempt to develop a generation of high temperature brazing filler metals was made in the late sixties-early seventies studies in detail were a large number of Ti-, Zr-Ti-Zr, Ti-V and Zr-V-Ti based alloys. The majority of these alloys has copper and nickel as melting temperature depressants. The presence of nickel and copper converts them into eutectic alloys having (Ti(Zr)) (Cu(Ni)), intermetallic phases as major structural constituents. This, in turn, results in high alloy brittleness and poor, if any, processability by means of conventional, i.e. melting-ingot casting-deformation technology. In spite of good wettability and high joint strength achieved in dozens of promising alloys, only Ti-15Cu-15Ni is now widely used as a brazing filler metal for high service temperature. Up until now this material could not be produced as a homogeneous foil and is instead applied as a clad strip consisting of three separate metallic layers.

  2. The distance between the posterior communicating arteries and their relation to the endoscopic third ventriculostomy in adults: An anatomic study

    PubMed Central

    Romero, Alicia Del Carmen Becerra; da Silva, Carlos Eduardo; de Aguiar, Paulo Henrique Pires

    2011-01-01

    Background: The diencephalic leaf of the Liliequist's membrane is a continuous structure that should be perforated in the endoscopic third ventriculostomy. Its lateral borders are penetrated by the third cranial nerve and the posterior communicating arteries. The most important complication of endoscopic third ventriculostomy is the vascular injury, such as the posterior communicating artery. The purpose of this study is to measure the distance between posterior communicating arteries located below the third ventricle floor and anterior of the mammillary bodies. Methods: In this observational prospective study 20 fresh brains from cadavers were utilized to measure the distance between the posterior communicating arteries in April 2008 at the Death Check Unit of our Institution. A digital photograph of the posterior communicating arteries was taken and the distance between the arteries was measured. The measurement was analyzed using descriptive statistics. Results: In the descriptive analysis of the 20 specimens, the posterior communicating arteries distance was 9 to 18.9 mm, a mean of 12.5 mm, median of 12.2 mm, standard deviation of 2.3 mm. Conclusion: The detailed knowledge of vascular structures involved in the endoscopic third ventriculostomy as to the posterior communicating arteries distance provides a safe lateral vascular border when performing such procedure. PMID:21748043

  3. Anomalous laser deflection phenomena based on the interaction of electro-optic and graded refractivity effect in Cu:KTN crystal

    NASA Astrophysics Data System (ADS)

    Wang, Xuping; Liu, Bing; Yang, Yuguo; Zhang, Yuanyuan; Lv, Xianshun; Hong, Guanglie; Shu, Rong; Yu, Haohai; Wang, Jiyang

    2014-12-01

    In this paper, we report an abnormal laser deflection phenomena based on quadratic electro-optic effect in copper doped KTN crystal. Cu:KTa0.62Nb0.38O3 block with size a×b×c = 2.8mm×2.6mm×12.5mm was used as beam deflection element. 75mrad beam deflection angle were observed under 1KV voltage when the laser beam across the c direction of the sample at room temperature. The special features of our experiment are that the direction of laser beam deflect perpendicular to the electric field direction, and the angular size and direction of the deflection beam remain unchanged when the electric field direction reverse. We believe that the interaction of graded refractivity and electro-optic effect leads to these special features. Besides of the special deflection mode, the deflection efficiency of our experiment also reached the world advanced level.

  4. Confocal Endomicroscopy: Instrumentation and Medical Applications

    PubMed Central

    Jabbour, Joey M.; Saldua, Meagan A.; Bixler, Joel N.; Maitland, Kristen C.

    2013-01-01

    Advances in fiber optic technology and miniaturized optics and mechanics have propelled confocal endomicroscopy into the clinical realm. This high resolution, non-invasive imaging technology provides the ability to microscopically evaluate cellular and sub-cellular features in tissue in vivo by optical sectioning. Because many cancers originate in epithelial tissues accessible by endoscopes, confocal endomicroscopy has been explored to detect regions of possible neoplasia at an earlier stage by imaging morphological features in vivo that are significant in histopathologic evaluation. This technique allows real-time assessment of tissue which may improve diagnostic yield by guiding biopsy. Research and development continues to reduce the overall size of the imaging probe, increase the image acquisition speed, and improve resolution and field of view of confocal endomicroscopes. Technical advances will continue to enable application to less accessible organs and more complex systems in the body. Lateral and axial resolutions down to 0.5 μm and 3 μm, respectively, field of view as large as 800×450 μm, and objective lens and total probe outer diameters down to 350 μm and 1.25 mm, respectively, have been achieved. We provide a review of the historical developments of confocal imaging in vivo, the evolution of endomicroscope instrumentation, and the medical applications of confocal endomicroscopy. PMID:21994069

  5. Large filters for wide-field survey telescope LSST

    NASA Astrophysics Data System (ADS)

    Morgado, Nazario; Pinard, Laurent; Sassolas, Benoit; Flaminio, Raffaele; Forest, Daniéle; Lagrange, Bernard; Michel, Christophe; Antilogus, Pierre

    2012-09-01

    The LSST design foresees the use of six wide-band large optical filters that can alternatively be moved in front of the CCD camera. Each of the six filters has a different band-pass covering all the wavelengths from 300 nm to 1200 nm. The way to achieve this is to coat an optimized optical thin films stack on a filter substrate. Each filter requires a specific design using specific appropriate materials. The main characteristics of these filters, that constitute a real technological challenge, are: their relatively large size - their radii of curvature (about 5.6 m) that represent a sagitta of 12,5 mm that increases the uniformity complexity, the large rejection band requirements with transmission lower than 0.01 % out of the band and a transmission of 95 % over the band-pass. This paper proposes to show the problematic and the results obtained at LMA (Laboratoire des Matériaux Avancés-FRANCE) to the purpose of realizing these filters using the IBS (Ion Beam Sputtering) deposition technique. The results obtained with High-Pass/Low-Pass structures will be presented. Experimental results will be shown concerning the R-band filter (552-691 nm). An overview of the work to be done to realize transmittance map over large filters will be given.

  6. Experimental investigation on chill-down process of cryogenic flow line

    NASA Astrophysics Data System (ADS)

    Jin, Lingxue; Park, Changgi; Cho, Hyokjin; Lee, Cheonkyu; Jeong, Sangkwon

    2016-10-01

    This paper describes the cryogenic chill-down experiments that are conducted on a 12.7 mm outer diameter, 1.25 mm wall thickness and 7 m long stainless steel horizontal pipe with liquid nitrogen (LN2). The pipe is vacuum insulated during the experiment to minimize the heat leak from room temperature and to enable one to numerically simulate the process easily. The temperature and the pressure profiles of the chill-down line are obtained at the location which is 5.5 m in a distance from the pipe inlet. The mass flux range is approximately from 19 kg/m2 s to 49 kg/m2 s, which corresponds to the Reynolds numbers range from 1469 to 5240. The transient histories of temperature, pressure and mass flow rate during the line chill-down process are monitored, and the heat transfer coefficient and the heat flux are computed by an inverse problem solving method. The amplitude of the pressure oscillation and the oscillating period become larger and longer at higher pressure conditions. In the low mass flux conditions, the critical heat flux in horizontal pipes is not sensitive to mass flux, and is higher than that in vertical pipes. Kutateladze's correlation with the constant coefficient, B = 0.029 , well matches the experimental data in the current work. In nucleate flow boiling regime, heat transfer coefficient, h , is proportional to (q″)n , and n is equal to 0.7.

  7. The possibility of E-glass woven roving as reinforcement of GFRP composite sheet roof

    NASA Astrophysics Data System (ADS)

    Setyanto, Djoko

    2016-03-01

    The 1.25 mm thickness of opaque glass fiber reinforced polymer (GFRP) composite sheet roof that is produced by an Indonesia company at Tangerang, consists of two layers of 300 g/m2 E-glass chopped strand mat as reinforcement and unsaturated polyester resin as matrix. A layer of 300 g/m2 E-glass chopped strand mat is replaced by a layer of 400 g/m2 E-glass woven roving as reinforcement to study the possibility use as sheet roof material. The properties of the two samples of GFRP composite materials were compared. Barcol hardness and flexure strength of the two samples relatively not significance change. Tensile strength and elastic modulus of the new sample which contains a layer of woven roving reinforcement is greater than the other one. On the other hand the waviness of the new sample is greater, but cheaper. In general, a layer of E-glass woven roving and a layer of E-glass chopped strand mat can be considered as an alternative reinforcement of two layers reinforcement of GFRP composite material of sheet roof.

  8. Anisotropic Conductivity Tensor Imaging of In Vivo Canine Brain Using DT-MREIT.

    PubMed

    Jeong, Woo Chul; Sajib, Saurav Z K; Katoch, Nitish; Kim, Hyung Joong; Kwon, Oh In; Woo, Eung Je

    2017-01-01

    We present in vivo images of anisotropic electrical conductivity tensor distributions inside canine brains using diffusion tensor magnetic resonance electrical impedance tomography (DT-MREIT). The conductivity tensor is represented as a product of an ion mobility tensor and a scale factor of ion concentrations. Incorporating directional mobility information from water diffusion tensors, we developed a stable process to reconstruct anisotropic conductivity tensor images from measured magnetic flux density data using an MRI scanner. Devising a new image reconstruction algorithm, we reconstructed anisotropic conductivity tensor images of two canine brains with a pixel size of 1.25 mm. Though the reconstructed conductivity values matched well in general with those measured by using invasive probing methods, there were some discrepancies as well. The degree of white matter anisotropy was 2 to 4.5, which is smaller than previous findings of 5 to 10. The reconstructed conductivity value of the cerebrospinal fluid was about 1.3 S/m, which is smaller than previous measurements of about 1.8 S/m. Future studies of in vivo imaging experiments with disease models should follow this initial trial to validate clinical significance of DT-MREIT as a new diagnostic imaging modality. Applications in modeling and simulation studies of bioelectromagnetic phenomena including source imaging and electrical stimulation are also promising.

  9. Optimal egg size in a suboptimal environment: reproductive ecology of female Sonora mud turtles (Kinosternon sonoriense) in central Arizona, USA

    USGS Publications Warehouse

    Lovich, Jeffrey E.; Madrak, Sheila V.; Drost, Charles A.; Monatesti, Anthony J.; Casper, Dennis; Znari, Mohammed

    2012-01-01

    We studied the reproductive ecology of female Sonora mud turtles (Kinosternon sonoriense) at Montezuma Well, a chemically-challenging natural wetland in central Arizona, USA. Females matured between 115.5 and 125 mm carapace length (CL) and 36-54% produced eggs each year. Eggs were detected in X-radiographs from 23 April-28 September (2007-2008) and the highest proportion (56%) of adult females with eggs occurred in June and July. Clutch frequency was rarely more than once per year. Clutch size was weakly correlated with body size, ranged from 1-8 (mean = 4.96) and did not differ significantly between years. X-ray egg width ranged from 17.8-21.7 mm (mean 19.4 mm) and varied more among clutches than within. Mean X-ray egg width of a clutch did not vary significantly with CL of females, although X-ray pelvic aperture width increased with CL. We observed no evidence of a morphological constraint on egg width. In addition, greater variation in clutch size, relative to egg width, suggests that egg size is optimized in this hydrologically stable but chemically-challenging habitat. We suggest that the diversity of architectures exhibited by the turtle pelvis, and their associated lack of correspondence to taxonomic or behavioral groupings, explains some of the variation observed in egg size of turtles.

  10. Propagation of Axially Symmetric Detonation Waves

    SciTech Connect

    Druce, R L; Roeske, F; Souers, P C; Tarver, C M; Chow, C T S; Lee, R S; McGuire, E M; Overturf, G E; Vitello, P A

    2002-06-26

    We have studied the non-ideal propagation of detonation waves in LX-10 and in the insensitive explosive TATB. Explosively-driven, 5.8-mm-diameter, 0.125-mm-thick aluminum flyer plates were used to initiate 38-mm-diameter, hemispherical samples of LX-10 pressed to a density of 1.86 g/cm{sup 3} and of TATB at a density of 1.80 g/cm{sup 3}. The TATB powder was a grade called ultrafine (UFTATB), having an arithmetic mean particle diameter of about 8-10 {micro}m and a specific surface area of about 4.5 m{sup 2}/g. Using PMMA as a transducer, output pressure was measured at 5 discrete points on the booster using a Fabry-Perot velocimeter. Breakout time was measured on a line across the booster with a streak camera. Each of the experimental geometries was calculated using the Ignition and Growth Reactive Flow Model, the JWL++ Model and the Programmed Burn Model. Boosters at both ambient and cold (-20 C and -54 C) temperatures have been experimentally and computationally studied. A comparison of experimental and modeling results is presented.

  11. Method of visualisation influences accuracy of measurements in cone-beam computed tomography.

    PubMed

    Patcas, Raphael; Angst, Christine; Kellenberger, Christian J; Schätzle, Marc A; Ullrich, Oliver; Markic, Goran

    2015-09-01

    This study evaluated the potential impact of different visualisation methods of cone-beam computed tomography (CBCT) on the accuracy of linear measurements of calcified structures, and assessed their interchangeability. High resolution (0.125 mm voxel) CBCT scans were obtained from eight cadaveric heads. The distance between the alveolar bone ridge and the incisal edge was determined for all mandibular incisors and canines, both anatomically and with measurements based on the following five CBCT visualisation methods: isosurface, direct volume rendering, multiplanar reformatting (MPR), maximum intensity projection of the volume of interest (VOIMIP), and average intensity projection of the volume of interest (VOIAvIP). All radiological methods were tested for repeatability and compared with anatomical results for accuracy, and limits of agreement were established. Interchangeability was evaluated by reviewing disparities between the methods and disclosing deterministic differences. Fine intra- and inter-observer repeatability was asserted for all visualisation methods (intraclass correlation coefficient ≤0.81). Measurements were most accurate when performed on MPR images and performed most disappointingly on isosurface-based images. Direct volume rendering, VOIMIP and VOIAvIP achieved acceptable results. It can be concluded that visualisation methods influence the accuracy of CBCT measurements. The isosurface viewing method is not recommended, and multiplanar reformatted images should be favoured for linear measurements of calcified structures.

  12. Femtosecond laser induced nanostructuring for surface enhanced Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Messaoudi, H.; Das, S. K.; Lange, J.; Heinrich, F.; Schrader, S.; Frohme, M.; Grunwald, R.

    2014-03-01

    The formation of periodical nanostructures with femtosecond laser pulses was used to create highly efficient substrates for surface-enhanced Raman spectroscopy (SERS). We report about the structuring of silver and copper substrates and their application to the SERS of DNA (herring sperm) and protein molecules (egg albumen). The maximum enhancement factors were found on Ag substrates processed with the second harmonic generation (SHG) of a 1-kHz Ti:sapphire laser and structure periods near the SHG wavelength. In the case of copper, however, the highest enhancement was obtained with long-period ripples induced with at fundamental wavelength. This is explained by an additional significant influence of nanoparticles on the surface. Nanostructured areas in the range of 1.25 mm2 were obtained in 10 s. The surfaces were characterized by scanning electron microscopy, Fast Fourier Transform and Raman spectroscopy. Moreover, the role of the chemical modification of the metal structures is addressed. Thin oxide layers resulting from working in atmosphere which improve the biocompatibility were indicated by vibration spectra. It is expected that the detailed study of the mechanisms of laser-induced nanostructure formation will stimulate further applications of functionalized surfaces like photocatalysis, selective chemistry and nano-biology.

  13. Design and Construction of a Gamma Reaction History Diagnostic for the National Ignition Facility

    SciTech Connect

    Malone, R M; Evans, S C; Frogget, B C; Herrmann, H W; Kaufman, M I; Kim, Y H; Mack, J M; McGillivray, K D; Palagi, M; Stoeffl, W; Tibbitts, A; Tunnell, T W; Young, C S

    2009-10-22

    Gas Cherenkov detectors have been used to convert fusion gammas into photons to record gamma reaction history measurements. These gas detectors include a converter, pressurized gas volume, relay collection optics, and a photon detector. A novel design for the National Ignition Facility (NIF) using 90° off-axis parabolic mirrors efficiently collects signal from fusion gammas with 8-ps time dispersion. Fusion gammas are converted to Compton electrons, which generate broadband Cherenkov light (response is from 250 to 700 nm) in a pressurized gas cell. This light is relayed into a high-speed detector using three parabolic mirrors. The relay optics collect light from a 125-mm-diameter by 600-mm-long interchangeable gas (CO2 or SF6) volume. The parabolic mirrors were electroformed instead of diamond turned to reduce scattering of the UV light. All mirrors are bare aluminum coated for maximum reflectivity. This design incorporates a 4.2-ns time delay that allows the detector to recover from prompt radiation before it records the gamma signal. At NIF, a cluster of four channels will allow for increased dynamic range, as well as different gamma energy thresholds.

  14. Development of the Gliding Hole of the Dynamics Compression Plate

    NASA Astrophysics Data System (ADS)

    Salim, U. A.; Suyitno; Magetsari, R.; Mahardika, M.

    2017-02-01

    The gliding hole of the dynamics compression plate is designed to facilitate relative movement of pedicle screw during surgery application. The gliding hole shape is then geometrically complex. The gliding hole manufactured using machining processes used to employ ball-nose cutting tool. Then, production cost is expensive due to long production time. This study proposed to increase productivity of DCP products by introducing forming process (cold forming). The forming process used to involve any press tool devices. In the closed die forming press tool is designed with little allowance, then work-pieces is trapped in the mould after forming. Therefore, it is very important to determine hole geometry and dimensions of raw material in order to success on forming process. This study optimized the hole sizes with both geometry analytics and experiments. The success of the forming process was performed by increasing the holes size on the raw materials. The holes size need to be prepared is diameter of 5.5 mm with a length of 11.4 mm for the plate thickness 3 mm and diameter of 6 mm with a length of 12.5 mm for the plate thickness 4 mm.

  15. Aerodynamic performance of a vibrating piezoelectric fan under varied operational conditions

    NASA Astrophysics Data System (ADS)

    Stafford, J.; Jeffers, N.

    2014-07-01

    This paper experimentally examines the bulk aerodynamic performance of a vibrating fan operating in the first mode of vibration. The influence of operating condition on the local velocity field has also been investigated to understand the flow distribution at the exit region and determine the stalling condition for vibrating fans. Fan motion has been generated and controlled using a piezoelectric ceramic attached to a stainless steel cantilever. The frequency and amplitude at resonance were 109.4 Hz and 12.5 mm, respectively. A test facility has been developed to measure the pressure-flow characteristics of the vibrating fan and simultaneously conduct local velocity field measurements using particle image velocimetry. The results demonstrate the impact of system characteristics on the local velocity field. High momentum regions generated due to the oscillating motion exist with a component direction that is tangent to the blade at maximum displacement. These high velocity zones are significantly affected by increasing impedance while flow reversal is a dominant feature at maximum pressure rise. The findings outlined provide useful information for design of thermal management solutions that may incorporate this air cooling approach.

  16. Temporary hair loss using the long-pulsed alexandrite laser at 20 milliseconds.

    PubMed

    Raulin, C; Greve, B

    2000-03-01

    Facial hypertrichosis presents an enormous psychological burden for women. Temporary hair removal (waxing, plucking, etc.) and electrolysis are prolonged and unsatisfactory methods of treatment. For a few years several laser systems with varying wavelengths, pulse durations and energy fluences have been used successfully in laser epilation. In the retrospective study on hand, we report on results of 30 female patients with hypertrichosis in the facial area treated with the long pulse alexandrite laser at 20 msec (Cynosure PhotoGenica LPIR/Apogee; 755 nm; 20 msec; up to 30 J/cm2; 10 or 12.5 mm beam diameter) over an 18 month treatment period. After an average of 8 treatments, an average clearance rate of 75% could be achieved. Fair hair (white/blond/red) only showed a clearance rate of 10%. Hypo- and hyperpigmentation did not appear. The most frequent adverse effects were the occasional appearance of scattered crusting (17%), which healed without consequences, and folliculitis (13%). The average post-treatment observation time lasted 3.25 months. The long-pulsed alexandrite laser at a pulse duration of 20 msec is an effective and safe method of treatment of hypertrichosis in the facial region of women. Black hair responds considerably better to the laser treatment than fair hair. A longer post-treatment observation time is necessary, though, in order to provide evidence for the permanence of the success of the method.

  17. Ion-pair supercritical fluid chromatography of metoprolol and related amino alcohols on diol silica.

    PubMed

    Gyllenhaal, Olle; Edström, Lena; Persson, Bengt-Arne

    2006-11-17

    In this paper, a chromatographic system based on carbon dioxide with methanol as mobile phase, and diol silica as stationary phase has been investigated for metoprolol and related amino alcohols by addition of strong acids to systems with triethylamine base as primary additive. Standard conditions used were 10% of methanol, containing 24 mM of acid and 18 mM of triethylamine, in carbon dioxide with a flow rate of 1.5 ml min(-1). The column dimensions were 125 mm x 4 mm I.D. and kept at 40 degrees C with a back pressure of 150 bar. Effects on selectivity were stronger with trifluoroacetic acid than with ethanesulfonic acid. From a large set of related analytes, it was shown that selectivity changes were significant when the structure close to the nitrogen of the amino alcohol analyte differed. The stability of the column in the short time perspective was examined and it showed negligible changes. For a diastereoisomeric pair, not resolved in a basic system with triethylamine nor by addition of ethanesulfonic acid, resolution improved to about 2.1 with trifluoroacetic acid. The described approach offers a way to tune the selectivity of SFC systems when amines are analyzed without the need to change stationary phase for the chromatographic separation.

  18. Alternative method to treat oroantral communication and fistula with autogenous bone graft and platelet rich firbin

    PubMed Central

    Niedzielska, Iwona; Borgiel-Marek, Halina; Różanowski, Bartosz

    2016-01-01

    Background Removing a tooth from the jaw results in the occurrence of oroantral communication in beneficial anatomic conditions or in the case of a iatrogenic effect. Popularized treatments of the oroantral communication have numerous faults. Large bone defect eliminates the chance to introduce an implant. Purpose of this work was assessment of the usefulness of autogenous bone graft and PRF in normal bone regeneration in the site of oroantral communication. Material and Methods Bone regeneration in the site of oroantral communication was assessed in 20 patients. Bone defects were supplemented autogenous bone graft from mental protuberance in 14 cases and from oblique line in 6 cases. The graft was covered with a PRF membrane. Results In the study group in all cases closure of the oroantral communication was observed. The average width of the alveolar was 13 mm and the average height was 12.5 mm. In 3 patients an average increase of alveolar height of 1.5 mm was observed. Conclusions This method may be the best option to prepare alveolar for new implant and prosthetic solutions. Key words:Oroantral communication, oroantral fistula, autogenous bone graft, bone regeneration, platelet rich fibrin. PMID:27475687

  19. Measurement of enhanced heat transfer coefficient with perforated twisted tape inserts during condensation of R-245fa

    NASA Astrophysics Data System (ADS)

    Khatua, A. K.; Kumar, P.; Singh, H. N.; Kumar, R.

    2016-04-01

    The experimental conductive heat transfer results for flow through inserted perforated twisted tapes in a horizontal tube during condensation of pure R-245fa vapor. The test section consisting of two separate coaxial double pipes assembled in series, acted like a counter flow heat exchanger, where the refrigerant condensed inside the inner tube by rejecting heat to the cooling water flowing inside the outer tube in reversed direction. Data for three perforated twisted tapes having constant twist ratio of 7.1 mm and pitch of perforation as 12.5, 25.0 and 37.5 mm, inserted one by one in full length of test condenser by varying refrigerant mass flux from 100 to 200 kg/m2 s in steps of 50 kg/m2 s for the range of vapor quality from 0.1 to 0.9, were collected together with flow and without insert (plain tube). It has been found that the perforated twisted tape insert having pitch of perforation equal to in order of 12.5 mm gives the highest value of average heat transfer coefficient and is of the order of 37.5 % more than that of the plain one and the correlation predicts the experimental data within an error band of ±15 %.

  20. Effect of layer thickness and printing orientation on mechanical properties and dimensional accuracy of 3D printed porous samples for bone tissue engineering.

    PubMed

    Farzadi, Arghavan; Solati-Hashjin, Mehran; Asadi-Eydivand, Mitra; Abu Osman, Noor Azuan

    2014-01-01

    Powder-based inkjet 3D printing method is one of the most attractive solid free form techniques. It involves a sequential layering process through which 3D porous scaffolds can be directly produced from computer-generated models. 3D printed products' quality are controlled by the optimal build parameters. In this study, Calcium Sulfate based powders were used for porous scaffolds fabrication. The printed scaffolds of 0.8 mm pore size, with different layer thickness and printing orientation, were subjected to the depowdering step. The effects of four layer thicknesses and printing orientations, (parallel to X, Y and Z), on the physical and mechanical properties of printed scaffolds were investigated. It was observed that the compressive strength, toughness and Young's modulus of samples with 0.1125 and 0.125 mm layer thickness were more than others. Furthermore, the results of SEM and μCT analyses showed that samples with 0.1125 mm layer thickness printed in X direction have more dimensional accuracy and significantly close to CAD software based designs with predefined pore size, porosity and pore interconnectivity.

  1. Cryogenic Testing of Different Seam Concepts for Multilayer Insulation Systems

    NASA Technical Reports Server (NTRS)

    Johnson, Wesley L.; Fesmire, J. E.

    2009-01-01

    Recent testing in a cylindrical, comparative cryostat at the Cryogenics Test Laboratory has focused on various seam concepts for multilayer insulation systems. Three main types of seams were investigated: straight overlap, fold-over, and roll wrapped. Each blanket was comprised of 40 layer pairs of reflector and spacer materials. The total thickness was approximately 12.5-mm, giving an average layer density of 32 layers per centimeter. The blankets were tested at high vacuum, soft vacuum, and no vacuum using liquid nitrogen to maintain the cold boundary temperature at 77 K. Test results show that all three seam concepts are all close in thermal performance; however the fold-over method provides the lowest heat flux. For the first series of tests, seams were located 120 degrees around the circumference of the cryostat from the previous seam. This technique appears to have lessened the degradation of the blanket due to the seams. In a follow-on test, a 20 layer blanket was tested in a roll wrapped configuration and then cut down the side of the cylinder, taped together, and re-tested. This test result shows the thermal performance impact of having the seams all in one location versus having the seams clocked around the vessel. This experimental investigation indicates that the method of joining the seams in multilayer insulation systems is not as critical as the quality of the installation process.

  2. Flexible laser welding of tailored blanks in small batch series

    NASA Astrophysics Data System (ADS)

    Bagger, Claus B.; Olsen, Flemming O.

    2003-03-01

    In a EU Craft project including eight partners in five countries, the most important aspects regarding efficient and low cost manufacture by small and medium sized enterprises (SME) of tailored blanks has been systematically investigated. In this paper, small batch series laser welding of tailored blanks in SME will be described. This includes the design, development and systematic use of a flexible and low cost clamping device as well as the practical experience obtained on the job shop through systematic optimization of welding of tailored blanks with even and uneven thickness (0.75 and 1.25 mm). A clamping device that is able to hold finished parts up to 1 x 1 m is successfully manufactured and tested. A special arrangement with alignment needles along the weld line is used to precisely position the sheets. These needles are turned into the clamping device during welding, where root shielding is employed. Hydraulic presses hold down the sheets, so they move less than 0.01 mm during welding. High quality tailored blank welds are successfully manufactured in ten different combinations, including mild steel and medium strength steel with even and uneven thickness with and without zinc coating.

  3. A 3D High Frequency Array Based 16 Channel Photoacoustic Microscopy System for In Vivo Micro-vascular Imaging

    PubMed Central

    Zemp, Roger; Yen, Jesse; Wang, L.V.; Shung, K. Kirk

    2009-01-01

    This paper discusses the design of a novel photoacoustic microscopy imaging system with promise for studying the structure of tissue microvasculature for applications in visualizing angiogenesis. A new sixteen channel analog and digital high frequency array based photoacoustic microscopy system (PAM) was developed using an Nd:YLF pumped tunable dye laser, a 30MHz piezo composite linear array transducer and a custom multi-channel receiver electronics system. Using offline delay and sum beamforming and beamsteering, phantom images were obtained from a 6µm carbon fiber in water at a depth of 8mm. The measured -6dB lateral and axial spatial resolution of the system was 100±5µm and 45±5µm, respectively. The dynamic focusing capability of the system was demonstrated by imaging a composite carbon fiber matrix through a 12.5mm imaging depth. Next, 2-D in vivo images were formed of vessels around 100µm in diameter in the human hand. 3-D in vivo images were also formed of micro-vessels 3mm below the surface of the skin in two Sprague Dawley rats. PMID:19131292

  4. Preliminary data on growth and reproduction of Cobitis simplicispina from Turkey.

    PubMed

    Ekmekçi, Fitnat Güler; Erk'akan, Füsun

    2003-01-01

    Preliminary data on growth and reproduction parameters of Cobitis simplicispina from Darýözü Creek in the Kizilimak basin in Kirşehir-Turkey were presented. The age of the specimens collected during a period between March and June 2002, ranged from 1+ to 4+. The observed maximum total length of males is 91.8 mm, and 97 mm for females. The von Bertalanffy equation for male and female specimens was found to be Lt=93.01(1-exp(-0.408(t+0.821))) and Lt=94.42(1-exp(-0.488(t+0.458))), respectively. The length-weight relationship was expressed as log W= 3.009x SL -5.171 when all specimens were taken into account. The range of absolute fecundity extended from 320 to 2141 eggs and the diameter of ripe eggs varied between 1.00 and 1.25 mm. The gonadosomatic index suggested that spawning took place in April.

  5. Spectrally resolved bioluminescence tomography using the reciprocity approach

    PubMed Central

    Dehghani, Hamid; Davis, Scott C.; Pogue, Brian W.

    2008-01-01

    Spectrally resolved bioluminescence optical tomography is an approach to recover images of, for example, Luciferase activity within a volume using multiwavelength emission data from internal bioluminescence sources. The underlying problem of uniqueness associated with nonspectrally resolved intensity-based bioluminescence tomography is demonstrated and it is shown that using a non-negative constraint inverse algorithm, an accurate solution for the source distribution can be calculated from the measured data. Reconstructed images of bioluminescence are presented using both simulated complex and heterogeneous small animal models as well as real multiwavelength data from a tissue-simulating phantom. The location of the internal bioluminescence source using experimental data is obtained with 0.5 mm accuracy and it is shown that small (2.5 mm diameter) sources of up to 12.5 mm deep, within a complex mouse model, can be resolved accurately using a single view data collection strategy. Finally, using the reciprocity approach for image reconstruction, a dramatic improvement in computational time is shown without loss to image accuracy with both experimental and simulated data, potentially reducing computing time from 402 to 3.75 h. PMID:19070220

  6. Behavior of turbulent gas jets in an axisymmetric confinement

    NASA Technical Reports Server (NTRS)

    So, R. M. C.; Ahmed, S. A.

    1985-01-01

    The understanding of the mixing of confined turbulent jets of different densities with air is of great importance to many industrial applications, such as gas turbine and Ramjet combustors. Although there have been numerous studies on the characteristics of free gas jets, little is known of the behavior of gas jets in a confinement. The jet, with a diameter of 8.73 mm, is aligned concentrically in a tube of 125 mm diameter, thus giving a confinement ratio of approximately 205. The arrangement forms part of the test section of an open-jet wind tunnel. Experiments are carried out with carbon dioxide, air and helium/air jets at different jet velocities. Mean velocity and turbulence measurements are made with a one-color, one-component laser Doppler velocimeter operating in the forward scatter mode. Measurements show that the jets are highly dissipative. Consequently, equilibrium jet characteristics similar to those found in free air jets are observed in the first two diameters downstream of the jet. These results are independent of the fluid densities and velocities. Decay of the jet, on the other hand, is a function of both the jet fluid density and momentum. In all the cases studied, the jet is found to be completely dissipated in approximately 30 jet diameters, thus giving rise to a uniform flow with a very high but constant turbulence field across the confinement.

  7. Simultaneous micellar LC determination of lidocaine and tolperisone.

    PubMed

    Youngvises, Napaporn; Liawruangrath, Boonsom; Liawruangrath, Saisunee

    2003-03-26

    A micellar liquid chromatography (MLC) procedure was developed for the simultaneous separation and determination of lidocaine hydrochloride (LD HCl) and tolperisone hydrochloride (TP HCl) using a short-column C18 (12.5 mm x 4.6 mm, 5 microm), sodium dodecyl sulfate (SDS) with a small amount of isopropanol, and diode array detector. The optimum conditions for the simultaneous determination of both drugs were 0.075 mol l(-1) SDS-7.5% (v/v) isopropanol with a flow rate of 0.7 ml min(-1) and detection at 210 nm. The LOD (2S/N) of LD HCl was 0.73 ng 20 microl(-1), whereas that of TP HCl was 1.43 ng 20 microl(-1). The calibration curves for LD HCl and TP HCl were linear over the ranges 0.125-500 microg ml(-1) (r(2)=0.9999) and 1.00-500 microg ml(-1) (r(2)=0.9997), respectively. The %recoveries of both drugs were in the range 98-103% and the %RSD values were less than 2. The proposed method has been successfully applied to the simultaneous determination of TP HCl and LD HCl in various pharmaceutical preparations.

  8. Critical bandwidth and consonance: their operational definitions in relation to cochlear nonlinearity and combination tones.

    PubMed

    Greenwood, D D

    1991-08-01

    A recent paper (Greenwood, 1990) reviewed cochlear coordinates in several species in relation to empirical frequency-position functions (Greenwood, 1961b, 1974b), one of which well fits the Békésy-Skarstein human cochlear map (Békésy, 1960; Kringlebotn et al, 1979). This increased the independence of the human function from the psychoacoustic data originally used to construct it and encouraged a second assessment of the relations of similar psychoacoustically significant bandwidths to distance and position on the cochlear map. The companion paper (Greenwood, 1991, this issue), found that, among such bandwidths, 'classical' critical bandwidth, and also 'constant interval', estimates in man correspond to equal distances to a closer extent than generally recognized, and over large parts of the frequency range they conform also to an exponential function of distance, as do most of the ERB estimates. This correspondence to almost constant and similar distances facilitates, and forms a part of, an explanation of the operational definitions of critical bandwidth in different experiments. The present account recapitulates the basic explanation of critical bandwidth and consonance offered in Greenwood (1971, 1972b, 1973b, 1974b) and Greenwood et al. (1976): by adding schematic details to the earlier account of critical bandwidth measurements in pure tone masking (the masker-notch interval), two-tone masking, narrow-band masking, and two-tone dissonance-consonance judgements and by outlining its applicability to AM and Quasi-FM detection and to two-band (nominally notched-noise) masking experiments. The measured bandwidths derive from approximately uniform dimensions of traveling wave envelopes in the peak region and from the effects of the resulting spatial pattern of nonlinear interference among primary components. In this account, critical bandwidth in man corresponds to a distance of about 1 or 1.25 mm, depending upon the direction the interval projects from the stimulus frequency to which it is referenced. It is identified with the apical segment of the traveling wave displacement envelope, which in guinea pig and squirrel monkey appears to be about 2/3rds and 3/4ths of a millimeter, respectively and would be about 1.25 mm in man if these distances were scaled (Greenwood, 1962) among these three species (Greenwood, 1974b, 1977a). When reflected also in the basal direction, the upper end of the frequency interval, at a 1.065 mm distance, makes a total two-critical-band distance, which corresponds with the region of nonlinear input-output functions that extends in both directions from the envelope peak and hence also with the frequency-dispersive region of accelerated phase accumulation (Greenwood, 1974b, 1977a).(ABSTRACT TRUNCATED AT 400 WORDS)

  9. TH-E-17A-04: Geometric Validation of K-Space Self-Gated 4D-MRI Vs. 4D-CT Using A Respiratory Motion Phantom

    SciTech Connect

    Yue, Y; Fan, Z; Yang, W; Pang, J; McKenzie, E; Deng, Z; Tuli, R; Sandler, H; Li, D; Fraass, B

    2014-06-15

    Purpose: 4D-CT is often limited by motion artifacts, low temporal resolution, and poor phase-based target definition. We recently developed a novel k-space self-gated 4D-MRI technique with high spatial and temporal resolution. The goal here is to geometrically validate 4D-MRI using a MRI-CT compatible respiratory motion phantom and comparison to 4D-CT. Methods: 4D-MRI was acquired using 3T spoiled gradient echo-based 3D projection sequences. Respiratory phases were resolved using self-gated k-space lines as the motion surrogate. Images were reconstructed into 10 temporal bins with 1.56×1.56×1.56mm3. A MRI-CT compatible phantom was designed with a 23mm diameter ball target filled with highconcentration gadolinium(Gd) gel embedded in a 35×40×63mm3 plastic box stabilized with low-concentration Gd gel. The whole phantom was driven by an air pump. Human respiratory motion was mimicked using the controller from a commercial dynamic phantom (RSD). Four breathing settings (rates/depths: 10s/20mm, 6s/15mm, 4s/10mm, 3s/7mm) were scanned with 4D-MRI and 4D-CT (slice thickness 1.25mm). Motion ground-truth was obtained from input signals and real-time video recordings. Reconstructed images were imported into Eclipse(Varian) for target contouring. Volumes and target positions were compared with ground-truth. Initial human study was investigated on a liver patient. Results: 4D-MRI and 4D-CT scans for the different breathing cycles were reconstructed with 10 phases. Target volume in each phase was measured for both 4D-CT and 4D-MRI. Volume percentage difference for the 6.37ml target ranged from 6.67±5.33 to 11.63±5.57 for 4D-CT and from 1.47±0.52 to 2.12±1.60 for 4D-MRI. The Mann-Whitney U-test shows the 4D-MRI is significantly superior to 4D-CT (p=0.021) for phase-based target definition. Centroid motion error ranges were 1.35–1.25mm (4D-CT), and 0.31–0.12mm (4D-MRI). Conclusion: The k-space self-gated 4D-MRI we recently developed can accurately determine phase-based target volume while avoiding typical motion artifacts found in 4D-CT, and is being further studied for use in GI targeting and motion management. This work supported in part by grant 1R03CA173273-01.

  10. Weight Estimation Tool for Children Aged 6 to 59 Months in Limited-Resource Settings

    PubMed Central

    2016-01-01

    .33%); proportion of estimates accurate to within ± 25% of true weight was 97.36% (95% CI 97.40%, 97.46%); and Bland-Altman bias and 95% limits of agreement were 0.05 kg and (-2.15 kg; 2.24 kg). The height model fitted for MUAC classes was accurate and precise. For MUAC < 115 mm, the proportion of estimates accurate to within ± 25% of true weight was 97.15% (95% CI 96.90%, 97.42%) and the Bland-Altman bias and 95% limits of agreement were 0.08 kg and (-1.21 kg; 1.37 kg). For MUAC between 115 and 125 mm, the proportion of estimates accurate to within ± 25% of true weight was 98.93% (95% CI 98.82%, 99.03%) and Bland-Altman bias and 95% limits of agreement were 0.05 kg and (-1.15 kg; 1.24 kg). For MUAC > 125 mm, the proportion of estimates accurate to within ± 25% of true weight was 98.33% (95% CI 98.29%, 98.37%) and Bland-Altman bias and 95% limits of agreement were 0.05 kg and (-2.08 kg; 2.19 kg). Conclusions and Relevance Models estimating weight from height alone and height with MUAC class in children aged 6–59 months in a database from low-to-middle income countries were more accurate and precise than previous weight estimation tools. A height-based weight estimation tape stratified according to MUAC classes is proposed for children aged 6–59 months in limited-resource settings. PMID:27529816

  11. Transition of carbon nanostructures in heptane diffusion flames

    NASA Astrophysics Data System (ADS)

    Hu, Wei-Chieh; Hou, Shuhn-Shyurng; Lin, Ta-Hui

    2017-02-01

    The flame synthesis has high potential in industrial production of carbon nanostructure (CNS). Unfortunately, the complexity of combustion chemistry leads to less controlling of synthesized products. In order to improve the understanding of the relation between flames and CNSs synthesized within, experiments were conducted through heptane flames in a stagnation-point liquid-pool system. The operating parameters for the synthesis include oxygen supply, sampling position, and sampling time. Two kinds of nanostructures were observed, carbon nanotube (CNT) and carbon nano-onion (CNO). CNTs were synthesized in a weaker flame near extinction. CNOs were synthesized in a more sooty flame. The average diameter of CNTs formed at oxygen concentration of 15% was in the range of 20-30 nm. For oxygen concentration of 17%, the average diameter of CNTs ranged from 24 to 27 nm, while that of CNOs was around 28 nm. For oxygen concentration of 19%, the average diameter of CNOs produced at the sampling position 0.5 mm below the flame front was about 57 nm, while the average diameters of CNOs formed at the sampling positions 1-2.5 mm below the flame front were in the range of 20-25 nm. A transition from CNT to CNO was observed by variation of sampling position in a flame. We found that the morphology of CNS is directly affected by the presence of soot layer due to the carbonaceous environment and the growth mechanisms of CNT and CNO. The sampling time can alter the yield of CNSs depending on the temperature of sampling position, but the morphology of products is not affected.

  12. A numerical study of transcranial focused ultrasound beam propagation at low frequency

    NASA Astrophysics Data System (ADS)

    Yin, Xiangtao; Hynynen, Kullervo

    2005-04-01

    The feasibility of transcranial ultrasound focusing with a non-moving phased array and without skull-specific aberration correction was investigated using computer simulations. Three cadaver skull CT image data sets were incorporated into an acoustic wave transmission model to simulate transskull ultrasound wave propagation. Using a 0.25 MHz hemispherical array (125 mm radius of curvature, 250 mm diameter, 24 255 elements), the simulated beams could be focused and steered with transducer element driving phases and amplitude adjusted for focal beam steering in water (water-path). A total of 82 foci, spanning wide ranges of distance in the three orthogonal dimensions, were simulated to test the focal beam steering capability inside the three skulls. The acoustic pressure distribution in a volume of 20 × 20 × 20 mm3 centred at each focus was calculated with a 0.5 mm spacing in each axis. Clearly defined foci were retained through the skulls (skull-path) in most cases. The skull-path foci were on average 1.6 ± 0.8 mm shifted from their intended locations. The -3 dB skull-path beam width and length were on average 4.3 ± 1.0 mm and 7.7 ± 1.8 mm, respectively. The skull-path sidelobe levels ranged from 25% to 55% of the peak pressure values. The skull-path peak pressure levels were about 10%-40% of their water-path counterparts. Focusing low-frequency beam through skull without skull-specific aberration correction is possible. This method may be useful for applying ultrasound to disrupt the blood-brain barrier for targeted delivery of therapeutic or diagnostic agents, or to induce microbubbles, or for other uses of ultrasound in brain where the required power levels are low and the sharp focusing is not needed.

  13. A numerical study of transcranial focused ultrasound beam propagation at low frequency.

    PubMed

    Yin, Xiangtao; Hynynen, Kullervo

    2005-04-21

    The feasibility of transcranial ultrasound focusing with a non-moving phased array and without skull-specific aberration correction was investigated using computer simulations. Three cadaver skull CT image data sets were incorporated into an acoustic wave transmission model to simulate transskull ultrasound wave propagation. Using a 0.25 MHz hemispherical array (125 mm radius of curvature, 250 mm diameter, 24 255 elements), the simulated beams could be focused and steered with transducer element driving phases and amplitude adjusted for focal beam steering in water (water-path). A total of 82 foci, spanning wide ranges of distance in the three orthogonal dimensions, were simulated to test the focal beam steering capability inside the three skulls. The acoustic pressure distribution in a volume of 20 x 20 x 20 mm(3) centred at each focus was calculated with a 0.5 mm spacing in each axis. Clearly defined foci were retained through the skulls (skull-path) in most cases. The skull-path foci were on average 1.6 +/- 0.8 mm shifted from their intended locations. The -3 dB skull-path beam width and length were on average 4.3 +/- 1.0 mm and 7.7 +/- 1.8 mm, respectively. The skull-path sidelobe levels ranged from 25% to 55% of the peak pressure values. The skull-path peak pressure levels were about 10%-40% of their water-path counterparts. Focusing low-frequency beam through skull without skull-specific aberration correction is possible. This method may be useful for applying ultrasound to disrupt the blood-brain barrier for targeted delivery of therapeutic or diagnostic agents, or to induce microbubbles, or for other uses of ultrasound in brain where the required power levels are low and the sharp focusing is not needed.

  14. Distinct development of the cerebral cortex in platypus and echidna.

    PubMed

    Ashwell, Ken W S; Hardman, Craig D

    2012-01-01

    Both lineages of the modern monotremes have distinctive features in the cerebral cortex, but the developmental mechanisms that produce such different adult cortical architecture remain unknown. Similarly, nothing is known about the differences and/or similarities between monotreme and therian cortical development. We have used material from the Hill embryological collection to try to answer key questions concerning cortical development in monotremes. Our findings indicate that gyrencephaly begins to emerge in the echidna brain shortly before birth (crown-rump length 12.5 mm), whereas the cortex of the platypus remains lissencephalic throughout development. The cortices of both monotremes are very immature at the time of hatching, much like that seen in marsupials, and both have a subventricular zone (SubV) within both the striatum and pallium during post-hatching development. It is particularly striking that in the platypus, this region has an extension from the palliostriatal angle beneath the developing trigeminoreceptive part of the somatosensory cortex of the lateral cortex. The putative SubV beneath the trigeminal part of S1 appears to accommodate at least two distinct types of cell and many mitotic figures and (particularly in the platypus) appears to be traversed by large numbers of thalamocortical axons as these grow in. The association with putative thalamocortical fibres suggests that this region may also serve functions similar to the subplate zone of Eutheria. These findings suggest that cortical development in each monotreme follows distinct paths from at least the time of birth, consistent with a long period of independent and divergent cortical evolution.

  15. A digital volumetric tomography (DVT) study in the mandibular molar region for miniscrew placement during mixed dentition

    PubMed Central

    Bhattad, Mayur S.; Baliga, Sudhindra; Vibhute, Pavan

    2015-01-01

    OBJECTIVE: To assess bone thickness for miniscrew placement in the mandible during mixed dentition by using digital volumetric tomograph (DVT). MATERIAL AND METHODS: A total of 15 healthy patients aged 8-10 years old, with early exfoliated mandibular second deciduous molar, were included. DVT images of one quadrant of the mandible were obtained using Kodak extraoral imaging systems and analyzed by Kodak dental imaging software. The error of the method (EM) was calculated using Dahlberg's formula. Mean and standard deviation were calculated at 6 and 8 mm from the cementoenamel junction (CEJ).Paired t-test was used to analyze the measurements. RESULTS: Buccal cortical bone thickness, mesiodistal width and buccolingual bone depth at 6 mm were found to be 1.73 + 0.41, 2.15 + 0.49 and 13.18 + 1.22 mm, respectively; while at 8 mm measurements were 2.42 + 0.34, 2.48 + 0.33 and 13.65 + 1.25 mm, respectively. EM for buccal cortical bone thickness, mesiodistal width and buccolingual bone depth was 0.58, 0.40 and 0.48, respectively. The difference in measurement at 6 and 8 mm for buccal cortical plate thickness (P < 0.05) and buccolingual bone thickness (P < 0.05) was found to be significant, whereas for mesiodistal width it was insignificant (P > 0.05). CONCLUSION: Bone thickness measurement has shown promising evidence for safe placement of miniscrews in the mandible during mixed dentition. The use of miniscrew is the best alternative, even in younger patients. PMID:25992988

  16. Thermal control modeling approach for GRAPE (GRAntecan PolarimEter)

    NASA Astrophysics Data System (ADS)

    Di Varano, I.; Woche, M.; Strassmeier, K. G.

    2016-08-01

    GRAPE is the polarimeter planned to be installed on the main Cassegrain focus of GTC (Gran Telescopio Canarias), having an equivalent entrance pupil of 10.4 m, located at the Observatorio del Roque de los Muchachos (ORM) , in La Palma, Canary Islands. It's meant to deliver full Stokes (IQUV) polarimetry covering the spectral range 0.420-1.6 μ, in order to feed the HORS instrument (High Optical Resolution Spectrograph), mounted on the Nasmyth platform, which has a FWHM resolving power of about 25,000 (5 pixel) designed for the wavelength range of 380-800 nm. Two calcite blocks and a BK-7 prism arranged in a Foster configuration are splitting the Ø12.5mm collimated beam into the ordinary and extraordinary components. The entire subunit from the Foster prisms down to the input fibers is rotated by steps of 45 degrees in order to retrieve Q, U components. By inserting a quarter wave retarder plate before the entrance to the Foster unit circular polarization is measured too. The current paper consist of two main parts: at first CFD simulations are introduced, which have been run compliant to the specifications derived by the environmental conditions and the transient thermal gradients taking into account the presence of the electronic cabinets installed, which are triggering the boundary conditions for the outer structure of the instrument; then a thermal control model is proposed based on heat exchangers to stabilize the inner temperature when compensation via passive insulation is not enough. The tools that have been adopted to reach for such goal are Ansys Multiphysics, in particular CFX package and Python scripts.

  17. Bench-scale experimental determination of the thermal diffusivity of crushed tuff

    SciTech Connect

    Ryder, E.E.; Finley, R.E.; George, J.T.; Ho, C.K.; Longenbaugh, R.S.; Connolly, J.R.

    1996-06-01

    A bench-scale experiment was designed and constructed to determine the effective thermal diffusivity of crushed tuff. Crushed tuff particles ranging from 12.5 mm to 37.5 mm (0.5 in. to 1.5 in.) were used to fill a cylindrical volume of 1.58 m{sup 3} at an effective porosity of 0.48. Two iterations of the experiment were completed; the first spanning approximately 502 hours and the second 237 hours. Temperatures near the axial heater reached 700 degrees C, with a significant volume of the test bed exceeding 100 degrees C. Three post-test analysis techniques were used to estimate the thermal diffusivity of the crushed tuff. The first approach used nonlinear parameter estimation linked to a one dimensional radial conduction model to estimate thermal diffusivity from the first 6 hours of test data. The second method used the multiphase TOUGH2 code in conjunction with the first 20 hours of test data not only to estimate the crushed tuffs thermal diffusivity, but also to explore convective behavior within the test bed. Finally, the nonlinear conduction code COYOTE-II was used to determine thermal properties based on 111 hours of cool-down data. The post-test thermal diffusivity estimates of 5.0 x 10-7 m{sup 2}/s to 6.6 x 10-7 m{sup 2}/s were converted to effective thermal conductivities and compared to estimates obtained from published porosity-based relationships. No obvious match between the experimental data and published relationships was found to exist; however, additional data for other particle sizes and porosities are needed.

  18. Fluorinated methacrylamide chitosan hydrogel systems as adaptable oxygen carriers for wound healing.

    PubMed

    Wijekoon, Asanka; Fountas-Davis, Natalie; Leipzig, Nic D

    2013-03-01

    In this study a series of novel, biocompatible hydrogels able to repeatedly takeup and deliver oxygen at beneficial levels have been developed by conjugating various perfluorocarbon (PFC) chains to methacrylamide chitosan via Schiff base nucleophilic substitution, followed by photopolymerization to form hydrogels. The synthesized fluorinated methacrylamide chitosan (MACF) hydrogels were confirmed by high resolution (19)F NMR. Synthesized MACF hydrogels were tested for their ability to takeup and then release oxygen for future use in dermal wound healing. Depending on the PFC substitution type maximum O(2) uptake was observed within 2-6h, followed by complete release to the surrounding environment (5% CO(2)) within 12-120h at oxygen partial pressures of 1-25mm Hg h(-1), providing outstanding system tuning for wound healing and regenerative medicine. MACFs with the most fluorines per substitution showed the greatest uptake and release of oxygen. Interestingly, adding PFC chains with a fluorinated aromatic group considerably enhanced oxygen uptake and extended release compared with a linear PFC chain with the same number of fluorine molecules. MACF hydrogels proved to be readily reloaded with oxygen once release was complete, and regeneration could be performed as long as the hydrogel was intact. Fibroblasts were cultured on MACFs and assays confirmed that materials containing more fluorines per substitution supported the most cells with the greatest metabolic activity. This result was true, even without oxygenation, suggesting PFC-facilitated oxygen diffusion from the culture medium. Finally, MACF gradient hydrogels were created, demonstrating that these materials can control oxygen levels on a spatial scale of millimeters and greatly enhance cellular proliferative and metabolic responses.

  19. Feasibility of CT-based 3D anatomic mapping with a scanning-beam digital x-ray (SBDX) system

    NASA Astrophysics Data System (ADS)

    Slagowski, Jordan M.; Tomkowiak, Michael T.; Dunkerley, David A. P.; Speidel, Michael A.

    2015-03-01

    This study investigates the feasibility of obtaining CT-derived 3D surfaces from data provided by the scanning-beam digital x-ray (SBDX) system. Simulated SBDX short-scan acquisitions of a Shepp-Logan and a thorax phantom containing a high contrast spherical volume were generated. 3D reconstructions were performed using a penalized weighted least squares method with total variation regularization (PWLS-TV), as well as a more efficient variant employing gridding of projection data to parallel rays (gPWLS-TV). Voxel noise, edge blurring, and surface accuracy were compared to gridded filtered back projection (gFBP). PWLS reconstruction of a noise-free reduced-size Shepp-Logan phantom had 1.4% rRMSE. In noisy gPWLS-TV reconstructions of a reduced-size thorax phantom, 99% of points on the segmented sphere perimeter were within 0.33, 0.47, and 0.70 mm of the ground truth, respectively, for fluences comparable to imaging through 18.0, 27.2, and 34.6 cm acrylic. Surface accuracies of gFBP and gPWLS-TV were similar at high fluences, while gPWLS-TV offered improvement at the lowest fluence. The gPWLS-TV voxel noise was reduced by 60% relative to gFBP, on average. High-contrast linespread functions measured 1.25 mm and 0.96 mm (FWHM) for gPWLS-TV and gFBP. In a simulation of gated and truncated projection data from a full-sized thorax, gPWLS-TV reconstruction yielded segmented surface points which were within 1.41 mm of ground truth. Results support the feasibility of 3D surface segmentation with SBDX. Further investigation of artifacts caused by data truncation and patient motion is warranted.

  20. Global estimation of effective plant rooting depth: Implications for hydrological modeling

    NASA Astrophysics Data System (ADS)

    Yang, Yuting; Donohue, Randall J.; McVicar, Tim R.

    2016-10-01

    Plant rooting depth (Zr) is a key parameter in hydrological and biogeochemical models, yet the global spatial distribution of Zr is largely unknown due to the difficulties in its direct measurement. Additionally, Zr observations are usually only representative of a single plant or several plants, which can differ greatly from the effective Zr over a modeling unit (e.g., catchment or grid-box). Here, we provide a global parameterization of an analytical Zr model that balances the marginal carbon cost and benefit of deeper roots, and produce a climatological (i.e., 1982-2010 average) global Zr map. To test the Zr estimates, we apply the estimated Zr in a highly transparent hydrological model (i.e., the Budyko-Choudhury-Porporato (BCP) model) to estimate mean annual actual evapotranspiration (E) across the globe. We then compare the estimated E with both water balance-based E observations at 32 major catchments and satellite grid-box retrievals across the globe. Our results show that the BCP model, when implemented with Zr estimated herein, optimally reproduced the spatial pattern of E at both scales (i.e., R2 = 0.94, RMSD = 74 mm yr-1 for catchments, and R2 = 0.90, RMSD = 125 mm yr-1 for grid-boxes) and provides improved model outputs when compared to BCP model results from two already existing global Zr data sets. These results suggest that our Zr estimates can be effectively used in state-of-the-art hydrological models, and potentially biogeochemical models, where the determination of Zr currently largely relies on biome type-based look-up tables.

  1. Effects of estrogen on functional and neurological recovery after spinal cord injury: An experimental study with rats

    PubMed Central

    Letaif, Olavo Biraghi; Cristante, Alexandre Fogaça; de Barros Filho, Tarcísio Eloy Pessoa; Ferreira, Ricardo; dos Santos, Gustavo Bispo; da Rocha, Ivan Dias; Marcon, Raphael Martus

    2015-01-01

    OBJECTIVES: To evaluate the functional and histological effects of estrogen as a neuroprotective agent after a standard experimentally induced spinal cord lesion. METHODS: In this experimental study, 20 male Wistar rats were divided into two groups: one group with rats undergoing spinal cord injury (SCI) at T10 and receiving estrogen therapy with 17-beta estradiol (4mg/kg) immediately following the injury and after the placement of skin sutures and a control group with rats only subjected to SCI. A moderate standard experimentally induced SCI was produced using a computerized device that dropped a weight on the rat's spine from a height of 12.5 mm. Functional recovery was verified with the Basso, Beattie and Bresnahan scale on the 2nd, 7th, 14th, 21st, 28th, 35th and 42nd days after injury and by quantifying the motor-evoked potential on the 42nd day after injury. Histopathological evaluation of the SCI area was performed after euthanasia on the 42nd day. RESULTS: The experimental group showed a significantly greater functional improvement from the 28th to the 42nd day of observation compared to the control group. The experimental group showed statistically significant improvements in the motor-evoked potential compared with the control group. The results of pathological histomorphometry evaluations showed a better neurological recovery in the experimental group, with respect to the proportion and diameter of the quantified nerve fibers. CONCLUSIONS: Estrogen administration provided benefits in neurological and functional motor recovery in rats with SCI beginning at the 28th day after injury. PMID:26598084

  2. Utilizing the VeraFlo™ Instillation Negative Pressure Wound Therapy System with Advanced Care for a Case Study

    PubMed Central

    2016-01-01

    Background: Mankind has always suffered wounds throughout time due to trauma, disease, and lifestyles. Many wounds are non-healing and have continued to be challenging. However, utilizing advanced wound care treatments, such as negative pressure wound treatment with instillation and dwell time (NPWTi-d), has proven beneficial. NPWTi-d is indicated in a variety of wounds, such as trauma, surgical, acute, pressure injuries, diabetic foot ulcers, and venous leg ulcers. Bacteria and bioburden interrupts wound healing by increasing the metabolic needs, ingesting, and robbing the necessary nutrients and oxygen. Instillation therapy is the technique of intermittently washing out a wound with a liquid solution. The mechanism of action is instilling fluid into the wound bed, soaking for a determined time, loosening and cleaning of exudate, contaminants, and/or infection, removing fluid via negative pressure, thus promoting tissue growth. Case study: The patient was diagnosed with a large lymphedema mass on the right upper thigh. Surgical removal of the lymphedema mass was indicated due to interference with quality of life. After a failed flap and surgical debridement, NPWTi-d with normal saline was implemented. Results: The patient had excellent results, with obvious forming of red, beefy granulation, epithelization tissue development, and a cleaner, healthier wound bed. Settings for the NPWTi-d was 18 minutes dwell time, every 2.5 hours with a constant pressure of 125 mm/hg pressure. Conclusion: The NPWTi-d demonstrated to be an instrumental treatment in supporting and stimulating healing. Early application of the treatment with normal saline as the instillation fluid prepared the previously failed wound for quicker healing. PMID:28070472

  3. Negative Pressure Wound Therapy of Chronically Infected Wounds Using 1% Acetic Acid Irrigation

    PubMed Central

    Lee, Byeong Ho; Lee, Hye Kyung; Kim, Hyoung Suk; Moon, Min Seon; Suh, In Suck

    2015-01-01

    Background Negative-pressure wound therapy (NPWT) induces angiogenesis and collagen synthesis to promote tissue healing. Although acetic acid soaks normalize alkali wound conditions to raise tissue oxygen saturation and deconstruct the biofilms of chronic wounds, frequent dressing changes are required. Methods Combined use of NPWT and acetic acid irrigation was assessed in the treatment of chronic wounds, instilling acetic acid solution (1%) beneath polyurethane membranes twice daily for three weeks under continuous pressure (125 mm Hg). Clinical photographs, pH levels, cultures, and debrided fragments of wounds were obtained pre- and posttreatment. Tissue immunostaining (CD31, Ki-67, and CD45) and reverse transcription-polymerase chain reaction (vascular endothelial growth factor [VEGF], vascular endothelial growth factor receptor [VEGFR]; procollagen; hypoxia-inducible factor 1 alpha [HIF-1-alpha]; matrix metalloproteinase [MMP]-1,-3,-9; and tissue inhibitor of metalloproteinase [TIMP]) were also performed. Results Wound sizes tended to diminish with the combined therapy, accompanied by drops in wound pH (weakly acidic or neutral) and less evidence of infection. CD31 and Ki-67 immunostaining increased (P<0.05) post-treatment, as did the levels of VEGFR, procollagen, and MMP-1 (P<0.05), whereas the VEGF, HIF-1-alpha, and MMP-9/TIMP levels declined (P<0.05). Conclusions By combining acetic acid irrigation with negative-pressure dressings, both the pH and the size of chronic wounds can be reduced and infections be controlled. This approach may enhance angiogenesis and collagen synthesis in wounds, restoring the extracellular matrix. PMID:25606491

  4. Optoacoustic tomography of breast cancer with arc-array transducer

    NASA Astrophysics Data System (ADS)

    Andreev, Valeri G.; Karabutov, Alexander A.; Solomatin, Sergey V.; Savateeva, Elena V.; Aleinikov, Vadim; Zhulina, Yulia V.; Fleming, R. Declan; Oraevsky, Alexander A.

    2000-05-01

    The second generation of the laser optoacoustic imaging system for breast cancer detection, localization and characterization using a 32-element arc-shaped transducer array was developed and tested. Each acoustic transducer was made of 110-micrometers thick SOLEF PVDF film with dimensions of 1mm X 12.5mm. The frequency band of transducer array provided 0.4-mm axial in-depth resolution. Cylindrical shape of this 10-cm long transducer array provided an improved lateral resolution of 1.0 mm. Original and compact design of low noise preamplifiers and wide band amplifiers was employed. The system sensitivity was optimized by choosing limited bandwidth of ultrasonic detection 20-kHz to 2-MHz. Signal processing was significantly improved and optimized resulting in reduced data collection time of 13 sec. The computer code for digital signal processing employed auto- gain control, high-pass filtering and denoising. An automatic recognition of the opto-acoustic signal detected from the irradiated surface was implemented in order to visualize the breast surface and improve the accuracy of tumor locations. Radial back-projection algorithm was used for image reconstruction. Optimal filtering of image was employed to reduce low and high frequency noise. The advantages and limitations of various contrast-enhancing filters applied to the entire image matrix were studied and discussed. Time necessary for image reconstruction was reduced to 32 sec. The system performance was evaluated initially via acquisition of 2D opto-acoustic images of small absorbing spheres in breast-tissue-like phantoms. Clinical ex-vivo studies of mastectomy specimen were also performed and compared with x-ray radiography and ultrasound.

  5. Microwave pretreatment can enhance tolerance of wheat seedlings to CdCl2 stress.

    PubMed

    Qiu, ZongBo; Li, JinTing; Zhang, YaJie; Bi, ZhenZhen; Wei, HuiFang

    2011-05-01

    In order to determine the role of microwave in cadmium stress tolerance of wheat (Triticum aestivum L.), seeds were exposed to microwave radiation for 0, 5, 10 and 15 s (wavelength 125 mm, power density 126 mW cm(-2), 2450 MHz), and when the seedlings were 7 d old (with one fully expanded leaves), they were treated with 150 μM CdCl(2) solution for 10 d. Changes in a number of physiological and biochemical characteristics were measured and used as indicators of the protective capacity of microwave radiation in this experiment. Our results showed that 150 μM CdCl(2) treatment reduced plant height, root length, dry weight, AsA and GSH concentration and the activities of SOD, POD, CAT and APX, enhanced the concentration of MDA, H(2)O(2) and the production rate of O(2)- when compared with the control. However, seeds with microwave pretreatment 5 or 10 s conferred tolerance to cadmium stress in wheat seedlings by decreasing the concentration of MDA and H(2)O(2), the production rate of O(2)- and increasing the activities of SOD, POD, CAT, APX and AsA and GSH concentration. Therefore, antioxidative enzymes and antioxidative compounds may participate in tolerance of wheat seedlings to cadmium stress. The results also showed that the microwave radiation had a positive physiological effect on the growth and development of cadmium stressed seedlings. This is the first investigation reporting the use of microwave pretreatment to enhance cadmium stress tolerance of wheat.

  6. Microwave treatment of eight seconds protects cells of Isatis indigotica from enhanced UV-B radiation lesions.

    PubMed

    Chen, Yi-Ping

    2006-01-01

    To determine the role of microwaves in the stress resistance of plants to enhanced ultraviolet-B (UV-B) radiation, Isatis indigotica Fort. seeds were subjected to microwave radiation for 8 s (wavelength 125 mm, power density 1.26 mW mm(-2), 2450 MHz). Afterwards they were cultivated in plastic pots in an artificial-glass greenhouse maintained at 25 degrees C, 70% relative humidity, and 400 micromol mol(-1) CO2, under visible-light conditions of 1500 micromol m(-2) s(-1) for 8 h day(-1). When the seedlings were 10 days old, they were subjected to 10.08 kJ m(-2) UV-B (PAR: 220 micromol m(-2) s(-1)) radiation for 8 days. Changes in a number of physiological and biochemical characteristics and in the thermal decomposition enthalpy of biomass were measured and used as indicators of the protective capacity of microwave radiation in this experiment. Our results revealed that microwave pretreatment of seeds enhanced UV-B stress resistance in the seedlings by decreasing the concentration of malondialdehyde (MDA) and increasing the concentration of ascorbic acid (AsA) and UV-B-absorbing compounds, increasing the activities of catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD), and increasing the energy accumulation of photosynthesis. All these results suggest that microwave radiation enhances plant metabolism and results in increased UV-B stress resistance. This is the first investigation reporting the use of microwave pretreatment to protect the cells of Isatis indigotica from UV-B-induced lesions.

  7. Position-resolved Positron Annihilation Lifetime Spectroscopy

    NASA Astrophysics Data System (ADS)

    Wagner, A.; Butterling, M.; Fiedler, F.; Fritz, F.; Kempe, M.; Cowan, T. E.

    2013-06-01

    A new method which allows for position-resolved positron lifetime spectroscopy studies in extended volume samples is presented. In addition to the existing technique of in-situ production of positrons inside large (cm3) bulk samples using high-energy photons up to 16 MeV from bremsstrahlung production, granular position-sensitive photon detectors have been employed. A beam of intense bremsstrahlung is provided by the superconducting electron linear accelerator ELBE (Electron Linear Accelerator with high Brilliance and low Emittance) which delivers electron bunches of less than 10 ps temporal width and an adjustable bunch separation of multiples of 38 ns, average beam currents of 1 mA, and energies up to 40 MeV. Since the generation of bremsstrahlung and the transport to the sample preserves the sharp timing of the electron beam, positrons generated inside the entire sample volume by pair production feature a sharp start time stamp for positron annihilation lifetime studies with high timing resolutions and high signal to background ratios due to the coincident detection of two annihilation photons. Two commercially available detectors from a high-resolution medial positron-emission tomography system are being employed with 169 individual Lu2SiO5:Ce scintillation crystals, each. In first experiments, a positron-lifetime gated image of a planar Si/SiO2 (pieces of 12.5 mm × 25 mm size) sample and a 3-D structured metal in Teflon target could be obtained proving the feasibility of a three dimensional lifetime-gated tomographic system.

  8. Effects of Heat Treatment on the Ballistic Impact Properties of Inconel 718 for Jet Engine Fan Containment Applications

    NASA Technical Reports Server (NTRS)

    Pereira, J. Michael; Lerch, Bradley A.

    2000-01-01

    The effects of heat treating Inconel 718 on the ballistic impact response and failure mechanisms were studied. Two different annealing conditions and an aged condition were considered. Large differences in the static properties were found between the annealed and the aged material, with the annealed condition having lower strength and hardness and greater elongation than the aged. Correspondingly large differences were found in the velocity required to penetrate material in the two conditions in impact tests involving 12.5 mm diameter, 25.4 mm long cylindrical Ti-6-4 projectiles impacting flat plates at velocities in the range of 150 to 300 m/sec. The annealed material was able to absorb over 25 percent more energy than the aged. This is contrary to results observed for ballistic impact response for higher velocity impacts typically encountered in military applications where it has been shown that there exists a correlation between target hardness and ballistic impact strength. Metallographic examination of impacted plates showed strong indication of failure due to adiabatic shear. In both materials localized bands of large shear deformation were apparent, and microhardness measurements indicated an increase in hardness in these bands compared to the surrounding material. These bands were more localized in the aged material than in the annealed material. In addition the annealed material underwent significantly greater overall deformation before failure. The results indicate that high elongation and better strain hardening capabilities reduce the tendency for shear to localize and result in an unstable adiabatic shear failure. This supports empirical containment design methods that relate containment thickness to the static toughness.

  9. Effects of Heat Treatment on the Ballistic Impact Properties of Inconel 718 for Jet Engine Fan Containment Applications

    NASA Technical Reports Server (NTRS)

    Pereira, J. Michael; Lerch, Bradley A.

    1999-01-01

    The effects of heat treating Inconel 718 on the ballistic impact response and failure mechanisms were studied. Two different annealing conditions and an aged condition were considered. Large differences in the static properties were found between the annealed and the aged material, with the annealed condition having lower strength and hardness and greater elongation than the aged. High strain rate tests show similar results. Correspondingly large differences were found in the velocity required to penetrate material in the two conditions in impact tests involving 12.5 mm diameter, 25.4 mm long cylindrical Ti-6-4 projectiles impacting flat plates at velocities in the range of 150 to 300 m/sec. The annealed material was able to absorb over 25 percent more energy than the aged. This is contrary to results observed for ballistic impact response for higher velocity impacts typically encountered in military applications where it has been shown that there exists a correlation between target hardness and ballistic impact strength. Metallographic examination of impacted plates showed strong indication of failure due to adiabatic shear. In both materials localized bands of large shear deformation were apparent, and microhardness measurements indicated an increase in hardness in these bands compared to the surrounding material. These bands were more localized in the aged material than in the annealed material. In addition the annealed material underwent significantly greater overall deformation before failure. The results indicate that lower elongation and reduced strain hardening behavior lead to a transition from shear to adiabatic shear failure, while high elongation and better strain hardening capabilities reduce the tendency for shear to localize and result in an unstable adiabatic shear failure. This supports empirical containment design methods that relate containment thickness to the static toughness.

  10. [Auriculo temporal nerve. Neuroanatomic bases of the Frey's syndrome].

    PubMed

    Decuadro-Sáenz, G; Castro, G; Sorrenti, N; Doassans, I; Deleon, S; Salle, F; Saibene, A; Santamaría, A; Pérez-Brignani, A; Soria-Vargas, V R

    2008-06-01

    The aim of this study was to precise the relationships of the auriculotemporal nerve in the infratemporal and parotid regions. We realized micro-dissections of thirty-two infratemporal and parotid regions of human cadaver's formol-fixed. The pattern of origin was: one root: 15.4%, two roots: 73.1%, three roots: 11.5%. In all cases, the lateral root present the major diameter (2-2.5 mm). In those cases with two roots, these formed a neural loop round the middle meningeal artery in the 89.4% of the cases. The origin of the medial root was the posterior border of the inferior alveolar nerve. The median distance between the lateral root and the temporomandibular joint capsule was 1.5 mm, with asymmetric pattern: right: 2 mm (rank: 0-7 mm; ED: 1.90 mm); left: 1.25 mm (rank: 0-3 mm; ED: 0.88 mm). In 10 cases (31.3%) the lateral root was in direct contact with the articular capsule, with asymmetric pattern: left: 46.1%; right: 21%. The median distance between the superior aspect of the articular disk and the trunk of the auriculotemporal nerve in the posterior aspect of the temporomandibular joint was 10,5 mm (ED: 4.06 mm), with asymmetric pattern: right: 9 mm (rank: 5-18.0 mm; ED: 3.70 mm); left: 11.0 mm (rank: 3.0-20 mm; ED: 4.41 mm). We discussed the rol of this findings in the etiology of the Frey's syndrome.

  11. Adenosine 3',5-cyclic monophosphate phosphodiesterase activity in granulosa cells from Booroola x Romney ewes with and without the F gene.

    PubMed

    McNatty, K P; Heath, D A; Lun, S; Hudson, N L

    1989-02-01

    Granulosa cells from ovarian follicles (greater than or equal to 1 mm diameter) in Booroola ewes which are homozygous (FF) or heterozygous (F+) for the F gene have previously been shown to produce significantly more cAMP in response to FSH or LH than those from similar sized follicles in ewes without the F gene (++). The aim of these studies was to test whether these F gene-specific differences arose because of differences in cAMP-phosphodiesterase (cAMP-PDE) activity. In the first study using 1 mumol cAMP/l as substrate, no F gene-specific effects were noted in cAMP-PDE activity in granulosa cells from small (1-2.5 mm diameter, n = 4 per genotype) or large (greater than or equal to 3 mm diameter, n = 4 per genotype) follicles from FF, F+ or ++ ewes, despite F gene-specific effects in FSH (1 microgram/ml)- and LH (0.1 microgram/ml)-induced cAMP accumulation in these same cell preparations. The overall mean levels of cAMP-PDE across all genotypes in cells from small and large follicles were 0.47 +/- 0.04 (S.E.M., n = 12) and 0.28 +/- 0.03 pmol cAMP/10(6) cells per min respectively; the mean PDE activity in cells from small follicles was significantly (P less than 0.05) higher compared with that in cells from large follicles. In a second study, granulosa cells from each genotype were pooled over all follicle sizes (greater than or equal to 1 mm diameter, one pool per genotype) and the rates of cAMP hydrolysis tested over a range of substrate concentrations (0-16 mumol/l) but no gene-specific differences with respect to the Michaelis constant and maximum velocity were noted.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Design and implementation of non-linear image processing functions for CMOS image sensor

    NASA Astrophysics Data System (ADS)

    Musa, Purnawarman; Sudiro, Sunny A.; Wibowo, Eri P.; Harmanto, Suryadi; Paindavoine, Michel

    2012-11-01

    Today, solid state image sensors are used in many applications like in mobile phones, video surveillance systems, embedded medical imaging and industrial vision systems. These image sensors require the integration in the focal plane (or near the focal plane) of complex image processing algorithms. Such devices must meet the constraints related to the quality of acquired images, speed and performance of embedded processing, as well as low power consumption. To achieve these objectives, low-level analog processing allows extracting the useful information in the scene directly. For example, edge detection step followed by a local maxima extraction will facilitate the high-level processing like objects pattern recognition in a visual scene. Our goal was to design an intelligent image sensor prototype achieving high-speed image acquisition and non-linear image processing (like local minima and maxima calculations). For this purpose, we present in this article the design and test of a 64×64 pixels image sensor built in a standard CMOS Technology 0.35 μm including non-linear image processing. The architecture of our sensor, named nLiRIC (non-Linear Rapid Image Capture), is based on the implementation of an analog Minima/Maxima Unit. This MMU calculates the minimum and maximum values (non-linear functions), in real time, in a 2×2 pixels neighbourhood. Each MMU needs 52 transistors and the pitch of one pixel is 40×40 mu m. The total area of the 64×64 pixels is 12.5mm2. Our tests have shown the validity of the main functions of our new image sensor like fast image acquisition (10K frames per second), minima/maxima calculations in less then one ms.

  13. Endovascular Stenting for Unsuccessful Angioplasty of the Aorta in Aortoarteritis

    SciTech Connect

    Tyagi, Sanjay; Kaul, Upkar A.; Arora, Ramesh

    1999-11-15

    Purpose: The efficacy and safety of endovascular stent implantation to correct dissection or a suboptimal result after percutaneous transluminal angioplasty (PTA) was evaluated in patients suffering from aortic stenosis due to aortoarteritis. Methods: Twelve children and young adults [aged (mean {+-} SD) 18.2 {+-} 8.7 years] underwent stent implantation after PTA of the aorta, seven for obstructive dissection, four for ineffective balloon dilatation, and one for recurrent restenosis. Nine patients underwent implantation of self-expandable stents and three received balloon-expandable Palmaz stents. Results: Stent implantation could be successfully performed in all 12 patients. After stent implantation, the peak systolic pressure gradient decreased from 91 {+-} 33.5 mmHg to 12.4 {+-} 12.5 mmHg (p < 0.001). The diameter of the stenosed segment increased from 4.6 {+-} 0.8 mm to 11.1 {+-} 1.9 mm (p < 0.001). The dissection was completely covered in all seven patients with dissection. Except for epigastric pain with vomiting in one patient, there was no complication. On follow-up, over 12-57 months (mean 26.8 {+-} 10.8 months), 11 patients (91.6%) had marked improvement in their blood pressure. Patients with congestive heart failure and claudication also showed improvement. Repeat catheterization in five patients, between 6-30 months (mean 16.8 {+-} 9.1 months) after stent implantation, showed sustained improvement in four and a fusiform, long segment, intrastent restenosis after 30 months in one child. The stenosis was safely redilated. Conclusion: Endovascular aortic stent implantation is safe and provides good immediate relief in patients with unsatisfactory results after balloon angioplasty. Improvement is sustained in most patients on intermediate-term follow-up.

  14. Estimation of Ground Water Recharge Using SWAT Model

    NASA Astrophysics Data System (ADS)

    Lee, D.; Chung, I.

    2006-12-01

    In this study the SWAT model was applied to estimate a shallow groundwater recharge at the watershed scale. The SWAT model is a semi-distributed comprehensive surface and subsurface flow model with the capability of simulating sediment and agricultural chemicals. The study site is Bocheongcheon watershed which is one of IHP experimental watersheds in Korea and the rainfall and stream flow have been monitored since 1984. The dominant land use types of the watershed are the mixed forest and agricultural land. The input data for SWAT model were prepared using the digital land use and soil maps with daily rainfall measured at ten rain gauge stations and the meteorological variables such as daily wind speed, relative humidity, solar radiation, and temperature collected within the watershed. The SWAT model was calibrated based on four years of daily stream flow data using the shuffled complex evolution global optimization method. Since there was no information for soil hydraulic properties, the various published pedotransfer functions were used for the specification of soil hydraulic conductivity. The annual recharge calculated from SWAT model ranged from 125 mm to 191 mm depending on the selected pedotransfer functions. Although the estimates of the regional groundwater recharge vary with the selection of pedotransfer functions, the performance measures between the simulated and measured daily stream flow are appeared to be similar. The result indicates that it is very difficult to identify a unique parameter set and the proper identification of spatially consistent soil hydraulic conductivity has an important implication for modeling groundwater recharge at the watershed scale using the spatially distributed watershed model such as SWAT.

  15. Treatment of denture-related stomatitis improves endothelial function assessed by flow-mediated vascular dilation

    PubMed Central

    Osmenda, Grzegorz; Maciąg, Joanna; Wilk, Grzegorz; Maciąg, Anna; Nowakowski, Daniel; Loster, Jolanta; Dembowska, Elżbieta; Robertson, Douglas; Guzik, Tomasz

    2016-01-01

    Introduction The presence of oral inflammation has recently been linked with the pathogenesis of cardiovascular diseases. While numerous studies have described links between periodontitis and endothelial dysfunction, little is known about the influence of denture-related stomatitis (DRS) on cardiovascular risk. Therefore, the aim of this study was to determine whether the treatment of DRS can lead to improvement of the clinical measures of vascular dysfunction. Material and methods The DRS patients were treated with a local oral antifungal agent for 3 weeks. Blood pressure, flow-mediated dilatation (FMD) and nitroglycerine-mediated vascular dilatation (NMD) were measured during three study visits: before treatment, one day and two months after conclusion of antifungal therapy. Results Flow-mediated dilatation measurements showed significant improvement of endothelial function 2 months after treatment (FMD median 5%, 95 CI: 3–8.3 vs. 11%, 95% CI: 8.8–14.4; p < 0.01), while there was no difference in control, endothelium-independent vasorelaxations (NMD; median = 15.3%, 95% CI: 10.8–19.3 vs. 12.7%, 95% CI: 10.6–15; p = 0.3). Other cardiovascular parameters such as systolic (median = 125 mm Hg; 95% CI: 116–129 vs. 120 mm Hg, 95% CI: 116–126; p = 0.1) as well as diastolic blood pressure and heart rate (median = 65.5 bpm, 95% CI: 56.7–77.7 vs. 71 bpm, 95% CI: 66.7–75; p = 0.5) did not change during or after the treatment. Conclusions Treatment of DRS is associated with improvement of endothelial function. Since endothelial dysfunction is known to precede the development of severe cardiovascular disorders such as atherosclerosis and hypertension, patients should be more carefully screened for DRS in general dental practice, and immediate DRS treatment should be advised. PMID:28144257

  16. [Preparation and release mechanism of gestodene reservoir-type intravaginal rings].

    PubMed

    Li, Chun-Xiao; Wang, Yan-Kun; Ning, Mei-Ying

    2014-03-01

    This study taking gestodene (GEST) as a model, investigated the factors affecting reservoir-type intravaginal ring (IVR)'s drug release. This paper reported a gestodene intravaginal ring of reservoir design, comprising a gestodene silicone elastomer core encased in a non-medicated silicone sheath, separately manufactured by reaction injection moulding at 80 degrees C and heating vulcanization at 130 degrees C is reported. The test investigated the factors affecting drug release through a single variable method, taking the drug release rates of 21 days as standards. When changing the thickness of the controlling sheath outside, the ratio of the first day of drug release and mean daily release (MDR), named the relatively burst effect, is closing to 1 with the thickness of controlling sheath increasing, while the 1.25 mm sheath corresponding to 1.04 controlled the burst release effectively; a positive correlation (r = 0.992 2) existed between the average drug release (Q/t) and drug loading (A) within a certain range. The C6-165 controlling sheath with high solubility of GEST is easier to achieve controlled release of the drug; GEST crystalline power is more effective to implement controlled release of drugs among difficent states of the drug. A 1/4 fractional segment core gives a relatively burst effect of 1.76, while the 1/1 and 1/2 are 1.93 and 1.87 separately, at the same drug loading, concluding that use of a fractional segment core would allow development of a suitable GEST reservoir IVR. In summary, GEST reservoir-type IVR could be adjusted by the thickness of controlling sheath, the loading of drug, the material properties of controlling sheath, the dispersion state of drug, the additive composition and structure of intravaginal ring, to control the drug release behavior and achieve the desired drug release rate.

  17. Summer habitat use by Columbia River redband trout in the Kootenai River drainage, Montana

    USGS Publications Warehouse

    Muhlfeld, Clint C.; Bennett, David H.

    2001-01-01

    The reported decline in the abundance, distribution, and genetic diversity of Columbia River redband trout Oncorhynchus mykiss gairdneri (a rainbow trout subspecies) has prompted fisheries managers to investigate their habitat requirements, identify critical habitat, and develop effective conservation and recovery programs. We analyzed the microhabitat, mesohabitat, and macrohabitat use and distribution of Columbia River redband trout by means of snorkel surveys in two watersheds in the Kootenai River drainage, Montana and Idaho, during the summers of 1997 and 1998. Juvenile (36–125 mm total length, TL) and adult (>=126 mm TL) fish preferred deep microhabitats (>=0.4 m) with low to moderate velocities (<=0.5 m/s) adjacent to the thalweg. Conversely, age-0 (<=35 mm) fish selected slow water (<=0.1 m/s) and shallow depths (<=0.2 m) located in lateral areas of the channel. Age-0, juvenile, and adult fish strongly selected pool mesohabitats and avoided riffles; juveniles and adults generally used runs in proportion to their availability. At the macrohabitat scale, density of Columbia River redband trout (35 mm) was positively related to the abundance of pools and negatively related to stream gradient. The pool: riffle ratio, gradient, and stream size combined accounted for 80% of the variation in density among 23 stream reaches in five streams. Our results demonstrate that low-gradient, medium-elevation reaches with an abundance of complex pools are critical areas for the production of Columbia River redband trout. These data will be useful in assessing the impacts of land-use practices on the remaining populations and may assist with habitat restoration or enhancement efforts.

  18. Challenges in Modeling Debris-Flow Initiation during the Exceptional September 2013 Northern Colorado Front Range Rainstorm

    NASA Astrophysics Data System (ADS)

    Baum, R. L.; Coe, J. A.; Godt, J.; Kean, J. W.

    2014-12-01

    Heavy rainfall during 9 - 13 September 2013 induced about 1100 debris flows in the foothills and mountains of the northern Colorado Front Range. Eye-witness accounts and fire-department records put the times of greatest landslide activity during the times of heaviest rainfall on September 12 - 13. Antecedent soil moisture was relatively low, particularly at elevations below 2250 m where many of the debris flows occurred, based on 45 - 125 mm of summer precipitation and absence of rainfall for about 2 weeks before the storm. Mapping from post-event imagery and field observations indicated that most debris flows initiated as small, shallow landslides. These landslides typically formed in colluvium that consisted of angular clasts in a sandy or silty matrix, depending on the nature of the parent bedrock. Weathered bedrock was partially exposed in the basal surfaces of many of the shallow source areas at depths ranging from 0.2 to 5 m, and source areas commonly occupied less than 500 m2. Although 49% of the source areas occurred in swales and 3 % in channels, where convergent flow might have contributed to pore-pressure build up during the rainfall, 48% of the source areas occurred on open slopes. Upslope contributing areas of most landslides (58%) were small (< 1000 m2) and 78% of the slides occurred on south-facing slopes (90°≤ aspect ≤270°). These observations pose challenges for modeling initiation of the debris flows. Effects of variable soil depth and properties, vegetation, and rainfall must be examined to explain the dominance of debris flows on south-facing slopes. Accounting for the small sizes and mixed swale and open-slope settings of source areas demands new approaches for resolving soil-depth and physical-properties variability. The low-moisture initial conditions require consideration of unsaturated zone effects. Ongoing fieldwork and computational modeling are aimed at addressing these challenges related to initiation of the September 2013 debris

  19. Novel combination strategies to repair the injured mammalian spinal cord.

    PubMed

    Bunge, Mary Bartlett

    2008-01-01

    Due to the varied and numerous changes in spinal cord tissue following injury, successful treatment for repair may involve strategies combining neuroprotection (pharmacological prevention of some of the damaging intracellular cascades that lead to secondary tissue loss), axonal regeneration promotion (cell transplantation, genetic engineering to increase growth factors, neutralization of inhibitory factors, reduction in scar formation), and rehabilitation. Our goal has been to find effective combination strategies to improve outcome after injury to the adult rat thoracic spinal cord. Combination interventions tested have been implantation of Schwann cells (SCs) plus neuroprotective agents and growth factors administered in various ways, olfactory ensheathing cell (OEC) implantation, chondroitinase addition, or elevation of cyclic AMP. The most efficacious strategy in our hands for the acute complete transection/SC bridge model, including improvement in locomotion [Basso, Beattie, Bresnahan Scale (BBB)], is the combination of SCs, OECs, and chondroitinase administration (BBB 2.1 vs 6.6, 3 times more myelinated axons in the SC bridge, increased serotonergic axons in the bridge and beyond, and significant correlation between the number of bridge myelinated axons and functional improvement). We found the most successful combination strategy for a subacute spinal cord contusion injury (12.5-mm, 10-g weight, MASCIS impactor) to be SCs and elevation of cyclic AMP (BBB 10.4 vs 15, significant increases in white matter sparing, in myelinated axons in the implant, and in responding reticular formation and red and raphe nuclei, and a significant correlation between the number of serotonergic fibers and improvement in locomotion). Thus, in two injury paradigms, these combination strategies as well as others studied in our laboratory have been found to be more effective than SCs alone and suggest ways in which clinical application may be developed.

  20. Estimating movement and survival rates of a small saltwater fish using autonomous antenna receiver arrays and passive integrated transponder tags

    USGS Publications Warehouse

    Rudershausen, Paul J.; Buckel, Jeffery A.; Dubreuil, Todd; O'Donnell, Matthew J.; Hightower, Joseph E.; Poland, Steven J.; Letcher, Benjamin H.

    2014-01-01

    We evaluated the performance of small (12.5 mm long) passive integrated transponder (PIT) tags and custom detection antennas for obtaining fine-scale movement and demographic data of mummichog Fundulus heteroclitus in a salt marsh creek. Apparent survival and detection probability were estimated using a Cormack Jolly Seber (CJS) model fitted to detection data collected by an array of 3 vertical antennas from November 2010 to March 2011 and by a single horizontal antenna from April to August 2011. Movement of mummichogs was monitored during the period when the array of vertical antennas was used. Antenna performance was examined in situ using tags placed in wooden dowels (drones) and in live mummichogs. Of the 44 tagged fish, 42 were resighted over the 9 mo monitoring period. The in situ detection probabilities of the drone and live mummichogs were high (~80-100%) when the ambient water depth was less than ~0.8 m. Upstream and downstream movement of mummichogs was related to hourly water depth and direction of tidal current in a way that maximized time periods over which mummichogs utilized the intertidal vegetated marsh. Apparent survival was lower during periods of colder water temperatures in December 2010 and early January 2011 (median estimate of daily apparent survival = 0.979) than during other periods of the study (median estimate of daily apparent survival = 0.992). During late fall and winter, temperature had a positive effect on the CJS detection probability of a tagged mummichog, likely due to greater fish activity over warmer periods. During the spring and summer, this pattern reversed possibly due to mummichogs having reduced activity during the hottest periods. This study demonstrates the utility of PIT tags and continuously operating autonomous detection systems for tracking fish at fine temporal scales, and improving estimates of demographic parameters in salt marsh creeks that are difficult or impractical to sample with active fishing gear.

  1. Hyoid Bone Development: An Assessment Of Optimal CT Scanner Parameters and Three-Dimensional Volume Rendering Techniques.

    PubMed

    Cotter, Meghan M; Whyms, Brian J; Kelly, Michael P; Doherty, Benjamin M; Gentry, Lindell R; Bersu, Edward T; Vorperian, Houri K

    2015-08-01

    The hyoid bone anchors and supports the vocal tract. Its complex shape is best studied in three dimensions, but it is difficult to capture on computed tomography (CT) images and three-dimensional volume renderings. The goal of this study was to determine the optimal CT scanning and rendering parameters to accurately measure the growth and developmental anatomy of the hyoid and to determine whether it is feasible and necessary to use these parameters in the measurement of hyoids from in vivo CT scans. Direct linear and volumetric measurements of skeletonized hyoid bone specimens were compared with corresponding CT images to determine the most accurate scanning parameters and three-dimensional rendering techniques. A pilot study was undertaken using in vivo scans from a retrospective CT database to determine feasibility of quantifying hyoid growth. Scanning parameters and rendering technique affected accuracy of measurements. Most linear CT measurements were within 10% of direct measurements; however, volume was overestimated when CT scans were acquired with a slice thickness greater than 1.25 mm. Slice-by-slice thresholding of hyoid images decreased volume overestimation. The pilot study revealed that the linear measurements tested correlate with age. A fine-tuned rendering approach applied to small slice thickness CT scans produces the most accurate measurements of hyoid bones. However, linear measurements can be accurately assessed from in vivo CT scans at a larger slice thickness. Such findings imply that investigation into the growth and development of the hyoid bone, and the vocal tract as a whole, can now be performed using these techniques.

  2. Herbicide incorporation by irrigation and tillage impact on runoff loss.

    PubMed

    Potter, Thomas L; Truman, Clint C; Strickland, Timothy C; Bosch, David D; Webster, Theodore M

    2008-01-01

    Runoff from farm fields is a common source of herbicide residues in surface waters. Incorporation by irrigation has the potential to reduce herbicide runoff risks. To assess impacts, rainfall was simulated on plots located in a peanut (Arachis hypogaea L.) field in Georgia's Atlantic Coastal Plain region after pre-emergence application of metolachlor (2-chloro-N-(2-ethyl-6-methylphenyl)-N-[(1S)-2-methoxy-1-methylethyl]-acetamide) and pendimethalin (N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitro-benzenamine). Runoff, sediment, and herbicide loss as function of strip tillage (ST) versus conventional tillage (CT) were compared with and without irrigation (12.5 mm) after application of an herbicide tank mixture. For the CT system, metolachlor runoff was reduced 2x and pendimethalin 1.2x when compared with the non-irrigated treatment. The difference in irrigated and non-irrigated metolachlor means was significant (P = 0.05). Irrigation reduced metolachlor runoff by 1.3x in the ST system, but there was a 1.4x increase for pendimethalin. Overall results indicated that irrigation incorporation reduces herbicide runoff with the greatest impact when CT is practiced and products like metolachlor, which have relatively low K(oc) and high water solubility, are used. The lower ST system response was likely due to a combination of spray interception and retention by the ST system cover crop mulch and higher ST soil organic carbon content and less total runoff. During the study, the measured K(oc) of both herbicides on runoff sediment was found to vary with tillage and irrigation after herbicide application. Generally, K(oc) was higher for ST sediment and when irrigation incorporation was used with the CT system. These results have significant implications for simulation model parametization.

  3. SU-E-J-72: Geant4 Simulations of Spot-Scanned Proton Beam Treatment Plans

    SciTech Connect

    Kanehira, T; Sutherland, K; Matsuura, T; Umegaki, K; Shirato, H

    2014-06-01

    Purpose: To evaluate density inhomogeneities which can effect dose distributions for real-time image gated spot-scanning proton therapy (RGPT), a dose calculation system, using treatment planning system VQA (Hitachi Ltd., Tokyo) spot position data, was developed based on Geant4. Methods: A Geant4 application was developed to simulate spot-scanned proton beams at Hokkaido University Hospital. A CT scan (0.98 × 0.98 × 1.25 mm) was performed for prostate cancer treatment with three or four inserted gold markers (diameter 1.5 mm, volume 1.77 mm3) in or near the target tumor. The CT data was read into VQA. A spot scanning plan was generated and exported to text files, specifying the beam energy and position of each spot. The text files were converted and read into our Geant4-based software. The spot position was converted into steering magnet field strength (in Tesla) for our beam nozzle. Individual protons were tracked from the vacuum chamber, through the helium chamber, steering magnets, dose monitors, etc., in a straight, horizontal line. The patient CT data was converted into materials with variable density and placed in a parametrized volume at the isocenter. Gold fiducial markers were represented in the CT data by two adjacent voxels (volume 2.38 mm3). 600,000 proton histories were tracked for each target spot. As one beam contained about 1,000 spots, approximately 600 million histories were recorded for each beam on a blade server. Two plans were considered: two beam horizontal opposed (90 and 270 degree) and three beam (0, 90 and 270 degree). Results: We are able to convert spot scanning plans from VQA and simulate them with our Geant4-based code. Our system can be used to evaluate the effect of dose reduction caused by gold markers used for RGPT. Conclusion: Our Geant4 application is able to calculate dose distributions for spot scanned proton therapy.

  4. Histological observation of RGCs and optic nerve injury in acute ocular hypertension rats

    PubMed Central

    Li, Shuang; Fang, Jia-Hua; Jiang, Fa-Gang

    2010-01-01

    AIM To explore the injury of retinal ganglion cells (RGCs) and optic nerves in acute ocular hypertension (OHT) rats. METHODS We retrogradely labeled RGCs and optic nerves of Sprague-Dawley rats by injecting 20g/L fluorogold (FG) into bilateral superior colliculi. Twenty-four hours after the injection, the right eyes were performed physiological saline anterior chamber perfusion with intraocular pressure maintained at 100mmHg for 60 minutes, while the contralateral eyes were performed sham procedure as control group without elevation of the saline bottle. Retinal hematoxylin and eosin (HE) sections, retinal whole mounts and frozen sections were made 14 days later to observe the morphology and survival of RGCs. Frozen sections and transmission electron microscopy were utilized to investigate the histological manifestations of optic nerves at the same time. RESULTS A larger number of RGCs presented in control group. It had an average density of 1995±125/mm2 and distributed uniformly, while RGCs in OHT eyes reduced significantly to 1505±43/mm2 compared with control group (P<0.05). The optic nerves in control group showed stronger and more uniform fluorescence on the frozen sections, and the auxiliary fibers as well as myelin sheaths were in even and intact organization by transmission electron microscopy. However, exiguous fluorescence signals, vesicular dissociation and disintegration of myelin sheaths were found in OHT group. CONCLUSION The present study suggested that fluorogold retrograde tracing is a feasible, convenient method for quantitative and qualitative study of neuronal populations and axonal injury in acute ocular hypertension rats. PMID:22553581

  5. Improved Electromagnetic Shielding Performance of Lightweight Compression Molded Polypyrrole/Ferrite Composite Sheets

    NASA Astrophysics Data System (ADS)

    Varshney, Swati; Dhawan, S. K.

    2017-01-01

    An attempt has been made to design lightweight polypyrrole/carbon fibers and polypyrrole/carbon fibers/ferrofluid (Fe3O4 particles) composite sheets using novolac resin via compression molding for electromagnetic shielding applications. The optimized formulation has been achieved to get an excellent combination of thermal, mechanical, and electrical properties of the composite sheet. Structural and morphological studies were carried out by x-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. Polypyrrole/carbon fibers composite sheets shows maximum flexural strength and a flexural modulus of 62.4 ± 1 MPa and 0.60 ± 0.02 GPa, respectively, with total shielding effectiveness of 22.8 dB in the Ku-band (12.4-18 GHz) but when ferrofluid is added to the polypyrrole/carbon fibers composite system, flexural strength increases to 92.3 ± 1 MPa and the same trend has been observed for flexural modulus with a value of 0.65 ± 0.04 GPa. This multiphase lightweight polypyrrole composite sheet having 34 vol.% of carbon fibers and 4 vol.% of Fe3O4 nanoparticles offers total shielding effectiveness of 31.9 dB (>99.99% attenuation) in the Ku-band (12.4-18 GHz) frequency range with a thickness of ˜1.25 mm. This is accredited to high dielectric losses and magnetic losses in conducting composite sheets. The observed results suggest that lightweight compression molded polypyrrole composite sheets could be a potential commercial alternative for electromagnetic shielding applications.

  6. Feasibility of CT-based 3D anatomic mapping with a scanning-beam digital x-ray (SBDX) system.

    PubMed

    Slagowski, Jordan M; Tomkowiak, Michael T; Dunkerley, David A P; Speidel, Michael A

    This study investigates the feasibility of obtaining CT-derived 3D surfaces from data provided by the scanning-beam digital x-ray (SBDX) system. Simulated SBDX short-scan acquisitions of a Shepp-Logan and a thorax phantom containing a high contrast spherical volume were generated. 3D reconstructions were performed using a penalized weighted least squares method with total variation regularization (PWLS-TV), as well as a more efficient variant employing gridding of projection data to parallel rays (gPWLS-TV). Voxel noise, edge blurring, and surface accuracy were compared to gridded filtered back projection (gFBP). PWLS reconstruction of a noise-free reduced-size Shepp-Logan phantom had 1.4% rRMSE. In noisy gPWLS-TV reconstructions of a reduced-size thorax phantom, 99% of points on the segmented sphere perimeter were within 0.33, 0.47, and 0.70 mm of the ground truth, respectively, for fluences comparable to imaging through 18.0, 27.2, and 34.6 cm acrylic. Surface accuracies of gFBP and gPWLS-TV were similar at high fluences, while gPWLS-TV offered improvement at the lowest fluence. The gPWLS-TV voxel noise was reduced by 60% relative to gFBP, on average. High-contrast linespread functions measured 1.25 mm and 0.96 mm (FWHM) for gPWLS-TV and gFBP. In a simulation of gated and truncated projection data from a full-sized thorax, gPWLS-TV reconstruction yielded segmented surface points which were within 1.41 mm of ground truth. Results support the feasibility of 3D surface segmentation with SBDX. Further investigation of artifacts caused by data truncation and patient motion is warranted.

  7. Can Blood Pressure Be Lowered Safely in Older Adults with Lacunar Stroke? The Secondary Prevention of Small Subcortical Strokes Study Experience

    PubMed Central

    White, Carole L.; Szychowski, Jeff M.; Pergola, Pablo E.; Field, Thalia S.; Talbert, Robert; Lau, Helena; Peri, Kalyani; Benavente, Oscar R.

    2015-01-01

    OBJECTIVES To determine safety and tolerability of lowering blood pressure in older adults with lacunar stroke. DESIGN Cohort study. SETTING The Secondary Prevention of Small Subcortical Strokes (SPS3) Trial, which compared the efficacy of two systolic blood pressure (SBP) targets (<130 mmHg and 130–149 mmHg) for secondary stroke prevention. PARTICIPANTS Of 3,020 SPS3 participants, 494 aged 75 and older at baseline were used in these analyses. MEASUREMENTS Rates of side effects related to lowering SBP and clinical outcomes, including stroke recurrence and vascular death, were examined. RESULTS Older participants achieved SBP levels similar to those of younger participants (mean SBP of 125 mmHg and 137 mmHg in lower and higher SBP target groups, respectively). At least once during the approximately 3.5 years of follow-up, 21% reported dizziness, and 15% reported lightheadedness when standing; the only significant difference between the younger and older groups was unsteadiness when standing (23% vs 32% respectively, P < .001). There was no difference according to treatment group. In younger adults, recurrent stroke was less likely in the lower than the higher SBP group (hazard ratio (HR) = 0.77, 95% confidence interval (CI) = 0.59–1.01) but not in older participants (HR = 1.01, 95% CI = 0.59– 1.73), although the interaction was not significant (P = .39). The lower SBP target was associated with a significant reduction in vascular death in older participants (HR = 0.42, 95% CI = 0.18–0.98), with a significant interaction between age and SBP group (P = .049). CONCLUSION Except for unsteadiness when standing, there was no difference according to age in individuals with lacunar stroke with respect to side effects potentially related to lowering blood pressure. Although the lower SBP target was not associated with lower likelihood of recurrent stroke, these exploratory analyses suggested a possible benefit related to vascular death. PMID:25850462

  8. Matrix cracking in brittle-matrix composites with tailored interfaces

    SciTech Connect

    Danchaivijit, S.; Chao, L.Y.; Shetty, D.K.

    1995-10-01

    Matrix cracking from controlled through cracks with bridging filaments was studied in a model unidirectional composite of SiC filaments in an epoxy-bonded alumina matrix. An unbonded, frictional interface was produced by moderating the curing shrinkage of the epoxy with the alumina filler and coating the filaments with a releasing agent. Uniaxial tension test specimens (2.5 x 25 x 125 mm) with filament-bridged through cracks were fabricated by a novel two-step casting technique involving casting, precracking and joining of cracked and uncracked sections. Distinct matrix-cracking stresses, corresponding to the extension of the filament-bridged cracks, were measured in uniaxial tension tests using a high-sensitivity extensometer. The crack-length dependence of the matrix-cracking stress was found to be in good agreement with the prediction of a fracture-mechanics analysis that employed a new crack-closure force-crack-opening displacement relation in the calculation of the stress intensity for fiber-bridged cracks. The prediction was based on independent experimental measurements of the matrix fracture toughness (K{sub cm}), the interfacial sliding friction stress ({tau}) and the residual stress in the matrix ({sigma}{sub m}{sup I}). The matrix-cracking stress for crack lengths (2a) greater than 3 mm was independent of the crack length and agreed with the prediction of the steady-state theory of Budiansky, Hutchinson and Evans. Tests on specimens without the deliberately introduced cracks indicated a matrix-cracking stress significantly higher than the steady-state stress.

  9. Morphological evaluation of eccentric sets guide-plates of dcp-l 4.5 mm

    PubMed Central

    Borges, José Humberto de Souza; da Silva Filho, Antonio Lisboa; Pereira Neto, Francisco; Daher, Walter Rodrigo; de Mesquita, Alessandro Queiroz; Freitas, Anderson

    2012-01-01

    Objective To carry out isolated and comparative evaluations of the measurements of the set eccentric guide plates used in 4.5mm surgical implants, and to determine the effect of these measurements on compression strength. Methods Four eccentric guides, four large dynamic compression plates (L-DCP) from four local manufacturers, and a Vonder® 200 mm caliper brand were used. Five standard parameter measurements were created for the set eccentric guide-plate, which were identified as A to E. Four sets were made, using materials of the same factory, and identified as groups I to IV. The analyses were performed by measuring all the parameters from a ventral view of the plate, with the eccentric guide placed in the plate hole. Results Groups I and II showed the same values for all the parameters. All the groups showed the same measurements for E = 8.15 e B = 3.60. Group III: A = 8.10mm, C = 3.25mm, D = 1.25mm. Group IV: A = 7.00mm, C = 3.10mm, D = 0.30mm. Maximum compression force was (F Max.): Group I 80.58 N, Group. II: F Max. 81.63 N, Group. III: F Max. 36.32N, Group. IV: F Max. 37.52N Conclusion The measurements evaluated show a lack of standardization in the manufacture of orthopedic instruments and its effects on the values for compression strength. Level of Evidence: Level III, analytical study. PMID:24453573

  10. Water Dynamics in Fogera and the Upper Blue Nile - Farmers perspectives and remote sensing

    NASA Astrophysics Data System (ADS)

    Chemin, Yann; Desalegn, Mengistu; Curnow, Jayne; Johnston, Robyn

    2015-04-01

    This research work is about finding the connection between farmers perspectives on changes of water conditions in their socio-agricultural environment and satellite remote sensing analysis. Key informant surveys were conducted to investigate localised views on water scarcity as a counterpoint to the physical measurement of water availability. Does a numerical or mapped image identifying water scarcity always equate to a dearth of water for agriculture? To push the limits of the relationship between human and physical data we sought to ground-truth GIS results with the practical experience and knowledge of people living in the area. We data-mined public domain satellite data with FOSS (GDAL, GRASS GIS) and produced water-related spatio-temporal domains for our study area and the larger Upper Nile Basin. Accumulated remote sensing information was then cross-referenced with informant's accounts of water availability for the same space and time. During the survey fieldwork the team also took photographs electronically stamped with GPS coordinates to compare and contrast the views of informants and the remote sensing information with high resolution images of the landscape. We found that farmers perspective on the Spring maize crop sensibility to variability of rainfall can be quantified in space and time by remote sensing cumulative transpiration. A crop transpiration gap of 1-2.5 mm/day for about 20 days is to be overcome, a full amount of 20 to 50 mm, depending on the type of year deficit. Such gap can be overcome, even by temporary supplemental irrigation practices, however, the economical and cultural set up is already developed in another way, as per sesonal renting of higher soil profile water retention capacity fields.

  11. Accuracy Assessment of Immediate and Delayed Implant Placements Using CAD/CAM Surgical Guides.

    PubMed

    Alzoubi, Fawaz; Massoomi, Nima; Nattestad, Anders

    2016-10-01

    The aim of this study is to assess the accuracy of immediately placed implants using Anatomage Invivo5 computer-assisted design/computer-assisted manufacturing (CAD/CAM) surgical guides and compare the accuracy to delayed implant placement protocol. Patients who had implants placed using Anatomage Invivo5 CAD/CAM surgical guides during the period of 2012-2015 were evaluated retrospectively. Patients who received immediate implant placements and/or delayed implant placements replacing 1-2 teeth were included in this study. Pre- and postsurgical images were superimposed to evaluate deviations at the crest, apex, and angle. A total of 40 implants placed in 29 patients were included in this study. The overall mean deviations measured at the crest, apex, and angle were 0.86 mm, 1.25 mm, and 3.79°, respectively. The means for the immediate group deviations were: crest = 0.85 mm, apex = 1.10, and angle = 3.49°. The means for the delayed group deviations were: crest = 0.88 mm, apex = 1.59, and angle = 4.29°. No statistically significant difference was found at the crest and angle; however, there was a statistically significant difference between the immediate and delayed group at the apex, with the immediate group presenting more accurate placements at the apical point than the delayed group. CAD/CAM surgical guides can be reliable tools to accurately place implants immediately and/or in a delayed fashion. No statistically significant differences were found between the delayed and the immediate group at the crest and angle, however apical position was more accurate in the immediate group.

  12. A three-dimensional culture system using alginate hydrogel prolongs hatched cattle embryo development in vitro.

    PubMed

    Zhao, Shuan; Liu, Zhen-Xing; Gao, Hui; Wu, Yi; Fang, Yuan; Wu, Shuai-Shuai; Li, Ming-Jie; Bai, Jia-Hua; Liu, Yan; Evans, Alexander; Zeng, Shen-Ming

    2015-07-15

    No successful method exists to maintain the three-dimensional architecture of hatched embryos in vitro. Alginate, a linear polysaccharide derived from brown algae, has characteristics that make it an ideal material as a three-dimensional (3D) extracellular matrix for in vitro cell, tissue, or embryo culture. In this study, alginate hydrogel was used for IVC of posthatched bovine embryos to observe their development under the 3D system. In vitro-fertilized and parthenogenetically activated posthatched bovine blastocysts were cultured in an alginate encapsulation culture system (AECS), an alginate overlay culture system (AOCS), or control culture system. After 18 days of culture, the survival rate of embryos cultured in AECS was higher than that in the control group (P < 0.05), and the embryos were expanded and elongated in AECS with the maximal length of 1.125 mm. When the AECS shrinking embryos were taken out of the alginate beads on Day 18 and cultured in the normal culture system, 9.09% of them attached to the bottoms of the plastic wells and grew rapidly, with the largest area of an attached embryo being 66.00 mm(2) on Day 32. The embryos cultured in AOCS developed monovesicular or multivesicular morphologies. Total cell number of the embryos cultured in AECS on Day 19 was significantly higher than that of embryos on Day 8. Additionally, AECS and AOCS supported differentiation of the embryonic cells. Binuclear cells were visible in Day-26 adherent embryos, and the messenger RNA expression patterns of Cdx2 and Oct4 in AOCS-cultured embryos were similar to those in vivo embryos, whereas IFNT and ISG15 messenger RNA were still expressed in Day-26 and Day-32 prolong-cultured embryos. In conclusion, AECS and AOCS did support cell proliferation, elongation, and differentiation of hatched bovine embryos during prolonged IVC. The culture system will be useful to further investigate the molecular mechanisms controlling ruminant embryo elongation and implantation.

  13. Simultaneous online SPE-HPLC-MS/MS analysis of docetaxel, temsirolimus and sirolimus in whole blood and human plasma.

    PubMed

    Navarrete, Alicia; Martínez-Alcázar, M Paz; Durán, Ignacio; Calvo, Emiliano; Valenzuela, Belén; Barbas, Coral; García, Antonia

    2013-03-15

    Docetaxel and temsirolimus are some of the most used drugs in a wide range of solid tumors. In preclinical studies, mTOR inhibitors such as temsirolimus have demonstrated synergistic cytotoxic effects with taxanes providing the rationale for combination studies. These anticancer agents exhibit a narrow therapeutic concentration range and due to their high inter- and intra-individual pharmacokinetic variability, therapeutic dose monitoring by highly sensitive methods as LC-MS/MS are important for clinical research. Therefore, the aim of this study was to develop and validate a sensitive, fast and convenient method for the simultaneous identification and quantification of docetaxel, temsirolimus and its main metabolite, sirolimus, using paclitaxel, another anticancer drug, as the internal standard. These analytes were quantified by an integrated online solid phase extraction-high performance liquid chromatography-tandem mass spectrometry (SPE-HPLC-MS/MS) system. Separation was performed on a Zorbax eclipse XDB-C8 (150mm×4.6mm, 5μm) column. The mass spectrometer tandem quadruple detector was equipped with jet stream electrospray ionization, monitored in multiple reactions monitoring (MRM) and operated in positive mode. A combination of protein precipitation with methanol/zinc sulphate (70:30) (v/v) and online SPE using a Zorbax eclipse plus C8 (12.5mm×4.6mm, 5μm) cartridge was used to extract the compounds. This method allows the use of the same reagents, sample treatment and analytical technique independently of whether the samples are whole blood or plasma. The method has been successfully validated and applied to real samples. It is a suitable method for dose adjustment and for evaluating potential drug interactions during combined treatments.

  14. Reconstruction filters and contrast detail curves in CT

    NASA Astrophysics Data System (ADS)

    Huda, W.; Ogden, K. M.; Samei, E.; Scalzetti, E. M.; Lavallee, R. L.; Roskopf, M. L.; Groat, G. E.

    2008-03-01

    In this study, we investigated the effect of CT reconstruction filters in abdominal CT images of a male anthropomorphic phantom. A GE Light Speed CT 4-slice scanner was used to scan the abdomen of an adult Rando phantom. Cross sectional images of the phantom were reconstructed using four reconstruction filters: (1) soft tissue with the lowest noise; (2) detail (relative noise 1.7); (3) bone (relative noise 4.5); and (4) edge (relative noise 7.7). A two Alternate Forced Choice (AFC) experimental paradigm was used to estimate the intensity needed to achieve 92% correct (i.e., I 92%). Four observers measured detection performance for five lesions with size ranging from 2.5 to 12.5 mm for each of these four reconstruction filters. Contrast detail curves obtained in images of an anthropomorphic phantom were not straight lines, but best fitted to a second order polynomial. Results from four readers show similar trends with modest inter-observer differences with the measured coefficient of variation of the absolute performance levels of ~22%. All reconstruction filters had similar shaped contrast detail curves except for smallest details where the frequency response of filters differed most significantly. Increasing the noise level always reduced detection performance, and a doubling of image noise resulted in an average drop in detection performance of ~20%. The key findings of this study are that (a) the Rose model can provide reasonable predictions as to how changes in lesion size affect observer detection; (b) the shape of CT contrast detail curves is affected only very slightly with reconstruction filter; (c) changes in reconstruction filter noise can predict qualitative changes in observer detection performance, but are poor direct predictors of the quantitative changes of imaging performance.

  15. Conversion Equation between the Drop Height in the New York University Impactor and the Impact Force in the Infinite Horizon Impactor in the Contusion Spinal Cord Injury Model.

    PubMed

    Khuyagbaatar, Batbayar; Kim, Kyungsoo; Kim, Yoon Hyuk

    2015-12-15

    There are several widely used devices for controlled contusion of the spinal cord, including the Ohio State University device, the University of British Columbia multi-mechanisms injury device, the New York University (NYU) impactor, and the Infinite Horizon (IH) impactor. Although various devices and protocols have been used to generate consistent injury severities, further investigation of the relationship between the key parameters of different spinal cord injury (SCI) contusion devices (e.g., drop height in the NYU impactor and impact force in the IH impactor) will improve our understanding of SCI mechanisms. A three-dimensional finite element model of the rat spinal cord from T9 to T10 that included the white and gray matters, dura mater, and cerebrospinal fluid was developed to investigate the von-Mises stress, maximum principal strain, and maximum displacement of the spinal cord for the drop height in the NYU impactor and the impact force in the IH impactor. A quantitative relationship was established as a conversion equation between two key parameters--i.e., the drop height and the impact force--in the NYU and IH impactors from regression equations for peak von-Mises stress, peak maximum principal strain, and maximum displacement in the spinal cord with respect to drop height and impact force with very high coefficients of determination. The consistent correlation was represented as a simple equation (Force = (28.2 ± 3.2) · Height((0.83 ± 0.07))) under the experimental conditions of a 10-g rod in the NYU impactor and an impact velocity of 125 mm/sec in the IH impactor. Thus, the key biomechanical parameter for a contusion device can be converted or translated to that of another device to analyze experimental results from multiple contusion devices.

  16. Clinical accuracy of ExacTrac intracranial frameless stereotactic system

    SciTech Connect

    Ackerly, T.; Lancaster, C. M.; Geso, M.; Roxby, K. J.

    2011-09-15

    Purpose: In this paper, the authors assess the accuracy of the Brainlab ExacTrac system for frameless intracranial stereotactic treatments in clinical practice. Methods: They recorded couch angle and image fusion results (comprising lateral, longitudinal, and vertical shifts, and rotation corrections about these axes) for 109 stereotactic radiosurgery and 166 stereotactic radiotherapy patient treatments. Frameless stereotactic treatments involve iterative 6D image fusion corrections applied until the results conform to customizable pass criteria, theirs being 0.7 mm and 0.5 deg. for each axis. The planning CT slice thickness was 1.25 mm. It has been reported in the literature that the CT slices' thickness impacts the accuracy of localization to bony anatomy. The principle of invariance with respect to patient orientation was used to determine spatial accuracy. Results: The data for radiosurgery comprised 927 image pairs, of which 532 passed (pass ratio of 57.4%). The data for radiotherapy comprised 15983 image pairs, of which 10 050 passed (pass ratio of 62.9%). For stereotactic radiotherapy, the combined uncertainty of ExacTrac calibration, image fusion, and intrafraction motion was (95% confidence interval) 0.290-0.302 and 0.306-0.319 mm in the longitudinal and lateral axes, respectively. The combined uncertainty of image fusion and intrafraction motion in the anterior-posterior coordinates was 0.174-0.182 mm. For stereotactic radiosurgery, the equivalent ranges are 0.323-0.393, 0.337-0.409, and 0.231-0.281 mm. The overall spatial accuracy was 1.24 mm for stereotactic radiotherapy (SRT) and 1.35 mm for stereotactic radiosurgery (SRS). Conclusions: The ExacTrac intracranial frameless stereotactic system spatial accuracy is adequate for clinical practice, and with the same pass criteria, SRT is more accurate than SRS. They now use frameless stereotaxy exclusively at their center.

  17. ALMA OBSERVATIONS OF THE DEBRIS DISK AROUND THE YOUNG SOLAR ANALOG HD 107146

    SciTech Connect

    Ricci, L.; Carpenter, J. M.; Fu, B.; Hughes, A. M.; Corder, S.; Isella, A.

    2015-01-10

    We present the Atacama Large Millimeter/submillimeter Array (ALMA) continuum observations at a wavelength of 1.25 mm of the debris disk surrounding the ∼100 Myr old solar analog HD 107146. The continuum emission extends from about 30 to 150 AU from the central star with a decrease in the surface brightness at intermediate radii. We analyze the ALMA interferometric visibilities using debris disk models with radial profiles for the dust surface density parameterized as (1) a single power law, (2) a single power law with a gap, and (3) a double power law. We find that models with a gap of radial width ∼8 AU at a distance of ∼80 AU from the central star, as well as double power-law models with a dip in the dust surface density at ∼70 AU provide significantly better fits to the ALMA data than single power-law models. We discuss possible scenarios for the origin of the HD 107146 debris disk using models of planetesimal belts in which the formation of Pluto-sized objects trigger disruptive collisions of large bodies, as well as models that consider the interaction of a planetary system with a planetesimal belt and spatial variation of the dust opacity across the disk. If future observations with higher angular resolution and sensitivity confirm the fully depleted gap structure discussed here, a planet with a mass of approximately a few Earth masses in a nearly circular orbit at ∼80 AU from the central star would be a possible explanation for the presence of the gap.

  18. Different systolic blood pressure targets for people with history of stroke or transient ischaemic attack: PAST-BP (Prevention After Stroke—Blood Pressure) randomised controlled trial

    PubMed Central

    McManus, Richard J; Roalfe, Andrea; Fletcher, Kate; Taylor, Clare J; Martin, Una; Virdee, Satnam; Greenfield, Sheila; Hobbs, F D Richard

    2016-01-01

    Objective To assess whether using intensive blood pressure targets leads to lower blood pressure in a community population of people with prevalent cerebrovascular disease. Design Open label randomised controlled trial. Setting 99 general practices in England, with participants recruited in 2009-11. Participants People with a history of stroke or transient ischaemic attack whose systolic blood pressure was 125 mm Hg or above. Interventions Intensive systolic blood pressure target (<130 mm Hg or 10 mm Hg reduction from baseline if this was <140 mm Hg) or standard target (<140 mm Hg). Apart from the different target, patients in both arms were actively managed in the same way with regular reviews by the primary care team. Main outcome measure Change in systolic blood pressure between baseline and 12 months. Results 529 patients (mean age 72) were enrolled, 266 to the intensive target arm and 263 to the standard target arm, of whom 379 were included in the primary analysis (182 (68%) intensive arm; 197 (75%) standard arm). 84 patients withdrew from the study during the follow-up period (52 intensive arm; 32 standard arm). Mean systolic blood pressure dropped by 16.1 mm Hg to 127.4 mm Hg in the intensive target arm and by 12.8 mm Hg to 129.4 mm Hg in the standard arm (difference between groups 2.9 (95% confidence interval 0.2 to 5.7) mm Hg; P=0.03). Conclusions Aiming for target below 130 mm Hg rather than 140 mm Hg for systolic blood pressure in people with cerebrovascular disease in primary care led to a small additional reduction in blood pressure. Active management of systolic blood pressure in this population using a <140 mm Hg target led to a clinically important reduction in blood pressure. Trial registration Current Controlled Trials ISRCTN29062286. PMID:26919870

  19. SU-E-I-18: CT Scanner QA Using Normalized CTDI Ratio

    SciTech Connect

    Randazzo, M; Tambasco, M; Russell, B

    2014-06-01

    Purpose: To create a ratio of weighted computed tomography dose index (CTDIw) data normalized to in-air measurements (CTDIair) as a function of beam quality to create a look-up table for frequent, rapid quality assurance (QA) checks of CTDI. Methods: The CTDIw values were measured according to TG-63 protocol using a pencil ionization chamber (Unfors Xi CT detector) and head and body Polymethyl methacrylate (PMMA) phantoms (16 and 32 cm diameter, respectively). Single scan dose profiles were measured at each clinically available energy (80,100,120,140 kVp) on three different CT scanners (two Siemens SOMATOM Definition Flash and one GE Optima), using a tube current of 400 mA, a one second rotation time, and the widest available beam width (32 × 0.6 mm and 16 × 1.25 mm, respectively). These values were normalized to CTDIair measurements using the same conditions as CTDIw. The ratios (expressed in cGy/R) were assessed for each scanner as a function of each energy's half value layer (HVL) paired with the phantom's appropriate bow tie filter measured in mmAl. Results: Normalized CTDI values vary linearly with HVL for both the head and body phantoms. The ratios for the two Siemens machines are very similar at each energy. Compared to the GE scanner, these values vary between 10–20% for each kVp setting. Differences in CTDIair contribute most to the deviation of the ratios across machines. Ratios are independent of both mAs and collimation. Conclusion: Look-up tables constructed of normalized CTDI values as a function of HVL can be used to derive CTDIw data from only three in-air measurements (one for CTDIair and two with added filtration for HVL) to allow for simple, frequent QA checks without CT phantom setup. Future investigations will involve comparing results with Monte Carlo simulations for validation.

  20. Effects of Heat Treatment on the Ballistic Impact Properties of Inconel 718 for Jet Engine Fan Containment Applications

    NASA Technical Reports Server (NTRS)

    Pereira, J. Michael; Lerch, Bradley A.

    2001-01-01

    The effects of heat treating Inconel 718 on the ballistic impact response and failure mechanisms were studied. Two different annealing conditions and an aged condition were considered. Large differences in the static properties were found between the annealed and the aged material, with the annealed condition having lower strength and hardness and greater elongation than the aged. High strain rate tests show similar results. Correspondingly large differences were found in the velocity required to penetrate material in the two conditions in impact tests involving 12.5 mm diameter, 25.4 mm long cylindrical Ti-6-4 projectiles impacting flat plates at velocities in the range of 150 to 300 m/sec. The annealed material was able to absorb over 25 percent more energy than the aged. This is contrary to results observed for ballistic impact response for higher velocity impacts typically encountered in military applications where it has been shown that there exists a correlation between target hardness and ballistic impact strength. Metallographic examination of impacted plates showed strong indication of failure due to adiabatic shear. In both materials localized bands of large shear deformation were apparent, and microhardness measurements indicated an increase in hardness in these bands compared to the surrounding material. These bands were more localized in the aged material than in the annealed material. In addition the annealed material underwent significantly greater overall deformation before failure. The results indicate that lower elongation and reduced strain hardening behavior lead to a transition from shear to adiabatic shear failure, while high elongation and better strain hardening capabilities reduce the tendency for shear to localize and result in an unstable adiabatic shear failure. This supports empirical containment design methods that relate containment thickness to the static toughness.

  1. Tamoxifen and Src kinase inhibitors as neuroprotective/neuroregenerative drugs after spinal cord injury

    PubMed Central

    Salgado, Iris K.; Torrado, Aranza I.; Santiago, Jose M.; Miranda, Jorge D.

    2015-01-01

    Spinal cord injury (SCI) is a devastating condition that produces significant changes in the lifestyle of patients. Many molecular and cellular events are triggered after the initial physical impact to the cord. Two major phases have been described in the field of SCI: an acute phase and late phase. Most of the therapeutic strategies are focused on the late phase because this provides an opportunity to target cellular events like apoptosis, demyelination, scar formation and axonal outgrowth. In this mini-review, we will focus on two agents (tamoxifen and a Src kinase family inhibitor known as PP2) that have been shown in our laboratory to produce neuroprotective (increase cell survival) and/or regenerative (axonal outgrowth) actions. The animal model used in our laboratory is adult female rat (~250 g) with a moderate contusion (12.5 mm) to the spinal cord at the T10 level, using the MASCIS impactor device. Tamoxifen or PP2 was administered by implantation of a 15 mg pellet (Innovative Research of America, Sarasota, FL, USA) or by intraperitoneal injections (1.5 mg/kg, every 3 days), respectively, to produce a long-term effect (28 days). Tamoxifen and the Src kinase inhibitor, PP2, are drugs that in rats with a moderate spinal cord injury promote functional locomotor recovery, increase spared white matter tissue, and stimulate axonal outgrowth. Moreover, tamoxifen reduces the formation of reactive oxygen species. Therefore, these drugs are possible therapeutic agents that have a neuroprotective/regenerative activity in vertebrates with SCI. PMID:25878585

  2. Manual discrimination of force

    NASA Technical Reports Server (NTRS)

    Pang, Xiao-Dong; Tan, HONG-Z.; Durlach, Nathaniel I.

    1991-01-01

    Optimal design of human-machine interfaces for teleoperators and virtual-environment systems which involve the tactual and kinesthetic modalities requires knowledge of the human's resolving power in these modalities. The resolution of the interface should be appropriately matched to that of the human operator. We report some preliminary results on the ability of the human hand to distinguish small differences in force under a variety of conditions. Experiments were conducted on force discrimination with the thumb pushing an interface that exerts a constant force over the pushing distance and the index finger pressing against a fixed support. The dependence of the sensitivity index d' on force increment can be fit by a straight line through the origin and the just-noticeable difference (JND) in force can thus be described by the inverse of the slope of this line. The receiver operating characteristic (ROC) was measured by varying the a priori probabilities of the two alternatives, reference force and reference force plus an increment, in one-interval, two-alternative, forced-choice experiments. When plotted on normal deviate coordinates, the ROC's were roughly straight lines of unit slope, thus supporting the assumption of equal-variance normal distributions and the use of the conventional d' measure. The JND was roughly 6-8 percent for reference force ranging from 2.5 to 10 newtons, pushing distance from 5 to 30 mm, and initial finger-span from 45 to 125 mm. Also, the JND remained the same when the subjects were instructed to change the average speed of pushing from 23 to 153 mm/sec. The pushing was terminated by reaching either a wall or a well, and the JND's were essentially the same in both cases.

  3. A reassessment of P2X7 receptor inhibition as a neuroprotective strategy in rat models of contusion injury.

    PubMed

    Marcillo, Alexander; Frydel, Beata; Bramlett, Helen M; Dietrich, W Dalton

    2012-02-01

    These experiments were completed as part of an NIH "Facilities of Research Excellence in Spinal Cord Injury" contract to support independent replication of published studies that could be considered for eventual clinical testing. Recent studies have reported that selective inhibition of the P2X7 receptor improves both the functional and histopathological consequences of a contusive spinal cord injury (SCI) in rats. We repeated two published studies reporting the beneficial effects of pyridoxal-5'-phosphate-6-azophenyl-2'-4'-disulphonic acid (PPADS) or Brilliant blue G (BBG) treatment after SCI (Wang et al., 2004 and Peng et al., 2009). Mild thoracic SCI was first produced in Experiment 1 by means of the MASCIS impactor at T10 (height 6.25 mm, weight 10 g) followed by intraspinal administration of a P2X7 antagonist (2 μl/10 mM) after injury. Treatment with PPADS or another highly selective P2X7R antagonist Brilliant Blue G (BBG) (2 μl/02 mM) did not improve locomotive (BBB rating scale) over a 7 week period compared to vehicle treated rats. Also, secondary histopathological changes in terms of overall lesion and cavity volume were not significantly different between the PPADS, BBG, and vehicle treated animals. In the second experiment, the systemic administration of BBG (10 or 50 mg/kg, iv) 15 min, 24 and 72 h after moderate (12.5 mm) SCI failed to significantly improve motor recovery or histopathological outcome over the 6 week observational period. Although we cannot conclude that there will be no long-term beneficial effects in other spinal cord injury models using selective P2X7 receptor antagonists at different doses or treatment durations, we caution researchers that this potentially exciting therapy requires further preclinical investigations before the implementation of clinical trials targeting severe SCI patients.

  4. Gender Differences of Airway Dimensions in Anatomically Matched Sites on CT in Smokers

    PubMed Central

    Kim, Yu-Il; Schroeder, Joyce; Lynch, David; Newell, John; Make, Barry; Friedlander, Adam; Estépar, Raúl San José; Hanania, Nicola A.; Washko, George; Murphy, James R.; Wilson, Carla; Hokanson, John E.; Zach, Jordan; Butterfield, Kiel; Bowler, Russell P.

    2013-01-01

    Rationale and Objectives There are limited data on, and controversies regarding gender differences in the airway dimensions of smokers. Multi-detector CT (MDCT) images were analyzed to examine whether gender could explain differences in airway dimensions of anatomically matched airways in smokers. Materials and Methods We used VIDA imaging software to analyze MDCT scans from 2047 smokers (M:F, 1021:1026) from the COPDGene® cohort. The airway dimensions were analyzed from segmental to subsubsegmental bronchi. We compared the differences of luminal area, inner diameter, wall thickness, wall area percentage (WA%) for each airway between men and women, and multiple linear regression including covariates (age, gender, body sizes, and other relevant confounding factors) was used to determine the predictors of each airway dimensions. Results Lumen area, internal diameter and wall thickness were smaller for women than men in all measured airway (18.4 vs 22.5 mm2 for segmental bronchial lumen area, 10.4 vs 12.5 mm2 for subsegmental bronchi, 6.5 vs 7.7 mm2 for subsubsegmental bronchi, respectively p < 0.001). However, women had greater WA% in subsegmental and subsubsegmental bronchi. In multivariate regression, gender remained one of the most significant predictors of WA%, lumen area, inner diameter and wall thickness. Conclusion Women smokers have higher WA%, but lower luminal area, internal diameter and airway thickness in anatomically matched airways as measured by CT scan than do male smokers. This difference may explain, in part, gender differences in the prevalence of COPD and airflow limitation. PMID:21756032

  5. Airborne sound insulation evaluation and flanking path prediction of coupled room

    NASA Astrophysics Data System (ADS)

    Tassia, R. D.; Asmoro, W. A.; Arifianto, D.

    2016-11-01

    One of the parameters to review the acoustic comfort is based on the value of the insulation partition in the classroom. The insulation value can be expressed by the sound transmission loss which converted into a single value as weighted sound reduction index (Rw, DnTw) and also have an additional sound correction factor in low frequency (C, Ctr) .In this study, the measurements were performed in two positions at each point using BSWA microphone and dodecahedron speaker as the sound source. The results of field measurements indicate the acoustic insulation values (DnT w + C) is 19.6 dB. It is noted that the partition wall not according to the standard which the DnTw + C> 51 dB. Hence the partition wall need to be redesign to improve acoustic insulation in the classroom. The design used gypsum board, plasterboard, cement board, and PVC as the replacement material. Based on the results, all the material is simulated in accordance with established standards. Best insulation is cement board with the insulation value is 69dB, the thickness of 12.5 mm on each side and the absorber material is 50 mm. Many factors lead to increase the value of acoustic insulation, such as the thickness of the panel, the addition of absorber material, density, and Poisson's ratio of a material. The prediction of flanking path can be estimated from noise reduction values at each measurement point in the class room. Based on data obtained, there is no significant change in noise reduction from each point so that the pathway of flanking is not affect the sound transmission in the classroom.

  6. Reducing the Use of Pesticides with Site-Specific Application: The Chemical Control of Rhizoctonia solani as a Case of Study for the Management of Soil-Borne Diseases

    PubMed Central

    Le Cointe, Ronan; Simon, Thomas E.; Delarue, Patrick; Hervé, Maxime; Leclerc, Melen; Poggi, Sylvain

    2016-01-01

    Reducing our reliance on pesticides is an essential step towards the sustainability of agricultural production. One approach involves the rational use of pesticides combined with innovative crop management. Most control strategies currently focus on the temporal aspect of epidemics, e.g. determining the optimal date for spraying, regardless of the spatial mechanics and ecology of disease spread. Designing innovative pest management strategies incorporating the spatial aspect of epidemics involves thorough knowledge on how disease control affects the life-history traits of the pathogen. In this study, using Rhizoctonia solani/Raphanus sativus as an example of a soil-borne pathosystem, we investigated the effects of a chemical control currently used by growers, Monceren® L, on key epidemiological components (saprotrophic spread and infectivity). We tested the potential “shield effect” of Monceren® L on pathogenic spread in a site-specific application context, i.e. the efficiency of this chemical to contain the spread of the fungus from an infected host when application is spatially localized, in our case, a strip placed between the infected host and a recipient bait. Our results showed that Monceren® L mainly inhibits the saprotrophic spread of the fungus in soil and may prevent the fungus from reaching its host plant. However, perhaps surprisingly we did not detect any significant effect of the fungicide on the pathogen infectivity. Finally, highly localized application of the fungicide—a narrow strip of soil (12.5 mm wide) sprayed with Monceren® L—significantly decreased local transmission of the pathogen, suggesting lowered risk of occurrence of invasive epidemics. Our results highlight that detailed knowledge on epidemiological processes could contribute to the design of innovative management strategies based on precision agriculture tools to improve the efficacy of disease control and reduce pesticide use. PMID:27668731

  7. Final test results for the Schott HCE on a LS-2 collector.

    SciTech Connect

    Moss, Timothy A.; Brosseau, Douglas A.

    2005-07-01

    Sandia National Laboratories has completed thermal performance testing on the Schott parabolic trough receiver using the LS-2 collector on the Sandia rotating platform at the National Solar Thermal Test Facility in Albuquerque, NM. This testing was funded as part of the US DOE Sun-Lab USA-Trough program. The receiver tested was a new Schott receiver, known as Heat Collector Elements (HCEs). Schott is a new manufacturer of trough HCEs. The Schott HCEs are 4m long; therefore, two were joined and mounted on the LS-2 collector module for the test. The Schott HCE design consists of a 70mm diameter high solar absorptance coated stainless steel (SS) tube encapsulated within a 125mm diameter Pyrex{reg_sign} glass tube with vacuum in the annulus formed between the SS and glass tube to minimize convection heat losses. The Schott HCE design is unique in two regards. First, the bellows used to compensate for the difference in thermal expansion between the metal and glass tube are inside the glass envelope rather than outside. Second, the composition of materials at the glass-to-metal seal has very similar thermal expansion coefficients making the joint less prone to breakage from thermal shock. Sandia National Laboratories provided both the azimuth and elevation collector module tracking systems used during the tests. The test results showed the efficiency of the Schott HCE to be very similar to current HCEs being manufactured by Solel. This testing provided performance verification for the use of Schott tubes with Solargenix trough collector assemblies at currently planned trough power plant projects in Arizona and Nevada.

  8. Late Quaternary slip history of the Mill Creek strand of the San Andreas fault in San Gorgonio Pass, southern California: The role of a subsidiary left-lateral fault in strand switching

    USGS Publications Warehouse

    Kendrick, Katherine J.; Matti, Jonathan; Mahan, Shannon

    2015-01-01

    The fault history of the Mill Creek strand of the San Andreas fault (SAF) in the San Gorgonio Pass region, along with the reconstructed geomorphology surrounding this fault strand, reveals the important role of the left-lateral Pinto Mountain fault in the regional fault strand switching. The Mill Creek strand has 7.1–8.7 km total slip. Following this displacement, the Pinto Mountain fault offset the Mill Creek strand 1–1.25 km, as SAF slip transferred to the San Bernardino, Banning, and Garnet Hill strands. An alluvial complex within the Mission Creek watershed can be linked to palinspastic reconstruction of drainage segments to constrain slip history of the Mill Creek strand. We investigated surface remnants through detailed geologic mapping, morphometric and stratigraphic analysis, geochronology, and pedogenic analysis. The degree of soil development constrains the duration of surface stability when correlated to other regional, independently dated pedons. This correlation indicates that the oldest surfaces are significantly older than 500 ka. Luminescence dates of 106 ka and 95 ka from (respectively) 5 and 4 m beneath a younger fan surface are consistent with age estimates based on soil-profile development. Offset of the Mill Creek strand by the Pinto Mountain fault suggests a short-term slip rate of ∼10–12.5 mm/yr for the Pinto Mountain fault, and a lower long-term slip rate. Uplift of the Yucaipa Ridge block during the period of Mill Creek strand activity is consistent with thermochronologic modeled uplift estimates.

  9. Controlled pitch-adjustment of impeller blades for an intravascular blood pump.

    PubMed

    Throckmorton, Amy L; Sciolino, Michael G; Downs, Emily A; Saxman, Robert S; López-Isaza, Sergio; Moskowitz, William B

    2012-01-01

    Thousands of mechanical blood pumps are currently providing circulatory support, and the incidence of their use continues to increase each year. As the use of blood pumps becomes more pervasive in the treatment of those patients with congestive heart failure, critical advances in design features to address known limitations and the integration of novel technologies become more imperative. To advance the current state-of-the-art in blood pump design, this study investigates the inclusion of pitch-adjusting blade features in intravascular blood pumps as a means to increase energy transfer; an approach not explored to date. A flexible impeller prototype was constructed with a configuration to allow for a variable range of twisted blade geometries of 60-250°. Hydraulic experiments using a blood analog fluid were conducted to characterize the pressure-flow performance for each of these twisted positions. The flexible, twisted impeller was able to produce 1-25 mmHg for 0.5-4 L/min at rotational speeds of 5,000-8,000 RPM. For a given twisted position, the pressure rise was found to decrease as a function of increasing flow rate, as expected. Generally, a steady increase in the pressure rise was observed as a function of higher twisted degrees for a constant rotational speed. Higher rotational speeds for a specific twisted impeller configuration resulted in a more substantial pressure generation. The findings of this study support the continued exploration of this unique design approach in the development of intravascular blood pumps.

  10. Accuracy in the diagnosis of vertical root fractures, external root resorptions, and root perforations using cone-beam computed tomography with different voxel sizes of acquisition

    PubMed Central

    Bragatto, Fernanda Paula; Iwaki Filho, Liogi; Kasuya, Amanda Vessoni Barbosa; Chicarelli, Mariliani; Queiroz, Alfredo Franco; Takeshita, Wilton Mitsunari; Iwaki, Lilian Cristina Vessoni

    2016-01-01

    Aim: The aim of this study is to assess the accuracy of images acquired with cone-beam computed tomography (CBCT) in the identification of three different root alterations. Materials and Methods: Forty human premolars were allocated to four experimental groups (n = 10): sound teeth (control), vertical root fracture (VRF), external root resorption (ERR), and root perforation (RP). After the root alterations had been produced, four teeth were randomly assembled into 10 macerated mandibles and submitted to CBCT. Images were acquired with five voxel sizes (0.125, 0.200, 0.250, 0.300, and 0.400 mm) and assessed by three experienced dental radiologists. Sensitivity, specificity, positive and negative predictive values, and the areas under the receiver operating characteristic curve (accuracy) were calculated. The accuracy of imaging in different voxel sizes was compared with Tukey exact binomial test (α=5%). Results: Accuracy with voxel sizes 0.125, 0.200, and 0.250 mm was significantly higher in the detection of ERRs and VRFs than voxel sizes 0.300 and 0.400 mm. No statistical difference was found in terms of accuracy among any of the studied voxel sizes in the identification of RPs. Conclusions: Voxel size 0.125 mm produced images with the best resolution without increasing radiation levels to the patient when compared to voxel sizes 0.200 and 0.250 mm. Voxel sizes 0.300 and 0.400 mm should be avoided in the identification of root alterations. PMID:27994322

  11. Characterization of shape and terminal velocity of tephra particles erupted during the 2002 eruption of Etna volcano, Italy

    NASA Astrophysics Data System (ADS)

    Coltelli, M.; Miraglia, L.; Scollo, S.

    2008-09-01

    In this paper, we present a complete morphological characterization of the ash particles erupted on 18 December 2002 from Etna volcano, Italy. The work is based on the acquisition and processing of bidimensional digital images carried out by scanning electron microscopy (SEM) to obtain shape parameters by image analysis. We measure aspect ratio (AR), form factor (FF), compactness (CC), and rectangularity (RT) of 2065 ash particles with size between 0.026 and 1.122 mm. We evaluate the variation of these parameters as a function of the grain-size. Ash particles with a diameter of <0.125 mm vary from mostly equant to very equant, ash particles between 0.125 and 0.250 mm have an intermediate shape, and particles with diameters >0.250 mm are subelongate. We find that, on average, particles with a diameter of <0.250 mm are subrounded, particles between 0.250 and 0.50 mm are subangular, and particles >0.50 mm are angular. Using this morphological analysis and an empirical relation between the drag coefficient ( C D) and Reynolds number ( R e) of Wilson and Huang (Earth Planet Sci Lett 44:311-324, 1979), we calculate the terminal settling velocities ( V WH). The comparisons between these velocities and those calculated with the formula of Kunii and Levenspiel ( Fluidization engineering. Wiley, New York, pp 97, 1969) ( V KL), which considers ash particles as spheres, show that V KL are in average 1.28 greater than V WH. Hence, we quantify the systematic error on the spatial distribution of the mass computed around the volcano carried out by tephra dispersal models when the particles are assumed to be spherical.

  12. Potential renovascular hypertension, space missions, and the role of magnesium

    PubMed Central

    Rowe, William J

    2009-01-01

    Space flight (SF) and dust inhalation in habitats cause hypertension whereas in SF (alone) there is no consistent hypertension but reduced diurnal blood pressure (BP) variation instead. Current pharmaceutical subcutaneous delivery systems are inadequate and there is impairment in the absorption, metabolism, excretion, and deterioration of some pharmaceuticals. Data obtained from the National Aeronautics and Space Administration through the Freedom of Information Act shows that Irwin returned from his 12-day Apollo 15 mission in 1971 and was administered a bicycle stress test. With just three minutes of exercise, his BP was >275/125 mm Hg (heart rate of only 130 beats per minute). There was no acute renal insult. Irwin’s apparent spontaneous remission is suggested to be related to the increase of a protective vasodilator, and his atrial natriuretic peptide (ANP) reduced with SF because of reduced plasma volume. With invariable malabsorption and loss of bone/muscle storage sites, there are significant (P < 0.0001) reductions of magnesium (Mg) required for ANP synthesis and release. Reductions of Mg and ANP can trigger pronounced angiotensin (200%), endothelin, and catecholamine elevations (clearly shown in recent years) and vicious cycles between the latter and Mg deficits. There is proteinuria, elevated creatinine, and reduced renal concentrating ability with the potential for progressive inflammatory and oxidative stress-induced renal disease and hypertension with vicious cycles. After SF, animals show myocardial endothelial injuries and increased vascular resistance of extremities in humans. Even without dust, hypertension might eventually develop from renovascular hypertension during very long missions. Without sufficient endothelial protection from pharmaceuticals, a comprehensive gene research program should begin now. PMID:21694921

  13. Does length of prostate biopsy cores have an impact on diagnosis of prostate cancer?

    PubMed Central

    Ergün, Müslüm; İslamoğlu, Ekrem; Yalçınkaya, Soner; Tokgöz, Hüsnü; Savaş, Murat

    2016-01-01

    Objective To investigate whether core length is a significant biopsy parameter in the detection of prostate cancer. Material and methods We retrospectively analyzed pathology reports of the specimens of 188 patients diagnosed with prostate cancer who had undergone initial transrectal ultrasound (TRUS) guided prostate biopsy, and compared biopsy core lengths of the patients with, and without prostate cancer. The biopsy specimens of prostate cancer patients were divided into 3 groups according to core length, and the data obtained were compared (Group 1; total core length <10 mm, Group 2; total core length 10 mm–19 mm, and Group 3; total core length >20 mm). Biopsy core lengths of the patients diagnosed as prostate cancer, and benign prostatic hyperplasia were compared, and a certain cut-off value for core length with optimal diagnostic sensitivity and specificity for prostate cancer was calculated. Results Mean age, PSA and total length of cores were 65.08±7.41 years, 9.82±6.34 ng/mL and 11.2±0.2 mm, respectively. Assessment of biopsy core lengths showed that cores with cancer (n=993, median length 12.5 mm) were significantly longer than benign cores (n=1185, median length=11.3 mm) (p<0.001). Core length analysis yielded 12 mm cores have an optimal sensitivity (41.9%) and specificity (62%) for detection of cancer (odds ratio: 1.08). Conclusion Biopsy core length is one of the most important parameter that determines the quality of biopsy and detection of prostate cancer. A median sample length of 12 mm is ideal lower limit for cancer detection, and biopsy procedures which yield shorter biopsy cores should be repeated. PMID:27635285

  14. Pulmonary airways tree segmentation from CT examinations using adaptive volume of interest

    NASA Astrophysics Data System (ADS)

    Park, Sang Cheol; Kim, Won Pil; Zheng, Bin; Leader, Joseph K.; Pu, Jiantao; Tan, Jun; Gur, David

    2009-02-01

    Airways tree segmentation is an important step in quantitatively assessing the severity of and changes in several lung diseases such as chronic obstructive pulmonary disease (COPD), asthma, and cystic fibrosis. It can also be used in guiding bronchoscopy. The purpose of this study is to develop an automated scheme for segmenting the airways tree structure depicted on chest CT examinations. After lung volume segmentation, the scheme defines the first cylinder-like volume of interest (VOI) using a series of images depicting the trachea. The scheme then iteratively defines and adds subsequent VOIs using a region growing algorithm combined with adaptively determined thresholds in order to trace possible sections of airways located inside the combined VOI in question. The airway tree segmentation process is automatically terminated after the scheme assesses all defined VOIs in the iteratively assembled VOI list. In this preliminary study, ten CT examinations with 1.25mm section thickness and two different CT image reconstruction kernels ("bone" and "standard") were selected and used to test the proposed airways tree segmentation scheme. The experiment results showed that (1) adopting this approach affectively prevented the scheme from infiltrating into the parenchyma, (2) the proposed method reasonably accurately segmented the airways trees with lower false positive identification rate as compared with other previously reported schemes that are based on 2-D image segmentation and data analyses, and (3) the proposed adaptive, iterative threshold selection method for the region growing step in each identified VOI enables the scheme to segment the airways trees reliably to the 4th generation in this limited dataset with successful segmentation up to the 5th generation in a fraction of the airways tree branches.

  15. Caffeine improves performance in double poling during acute exposure to 2,000-m altitude.

    PubMed

    Stadheim, H K; Nossum, E M; Olsen, R; Spencer, M; Jensen, J

    2015-12-15

    There is limited research on the physiological effects of caffeine (CAF) ingestion on exercise performance during acute hypoxia. The aim of the present study was therefore to test the effect of placebo (PLA) and CAF (4.5 mg/kg) on double poling (DP) performance during acute hypoxia. Thirteen male subelite cross-country skiers (V̇o2max 72.6 ± 5.68 ml·kg(-1)·min(-1)) were included. Performance was assessed as 1) an 8-km cross-country DP time-trial (C-PT), and 2) time until task failure at a set workload equal to ∼90% of DP V̇o2max. Testing was carried out in a hypobaric chamber, at 800 mbar (Pio2: ∼125 mmHg) corresponding to ∼2,000 m above sea level in a randomized double-blinded, placebo-controlled, cross-over design. CAF improved time to task failure from 6.10 ± 1.40 to 7.22 ± 1.30 min (P < 0.05) and velocity the first 4 km (P < 0.05) but not overall time usage for the 8-km C-PT. During submaximal exercise subjects reported lower pain in arms and rate of perceived exertion (RPE) following CAF ingestion. Throughout C-PTs similar RPE and pain was shown between treatments. However, higher heart rate was observed during the CAF 8 km (187 ± 7 vs. 185 ± 7; P < 0.05) and 90% C-PT (185 ± 7 vs. 181 ± 9) associated with increased ventilation, blood lactate, glucose, adrenaline, decreased pH, and bicarbonate. The present study demonstrates for the first time that CAF ingestion improves DP time to task failure although not consistently time trial performance during acute exposure to altitude. Mechanisms underpinning improvements seem related to reduced pain RPE and increased heart rate during CAF C-PTs.

  16. A Point-of-Care Immunosensor for Human Chorionic Gonadotropin in Clinical Urine Samples Using a Cuneated Polysilicon Nanogap Lab-on-Chip

    PubMed Central

    Balakrishnan, S. R.; Hashim, U.; Gopinath, Subash C. B.; Poopalan, P.; Ramayya, H. R.; Iqbal Omar, M.; Haarindraprasad, R.; Veeradasan, P.

    2015-01-01

    Human chorionic gonadotropin (hCG), a glycoprotein hormone secreted from the placenta, is a key molecule that indicates pregnancy. Here, we have designed a cost-effective, label-free, in situ point-of-care (POC) immunosensor to estimate hCG using a cuneated 25 nm polysilicon nanogap electrode. A tiny chip with the dimensions of 20.5 × 12.5 mm was fabricated using conventional lithography and size expansion techniques. Furthermore, the sensing surface was functionalized by (3-aminopropyl)triethoxysilane and quantitatively measured the variations in hCG levels from clinically obtained human urine samples. The dielectric properties of the present sensor are shown with a capacitance above 40 nF for samples from pregnant women; it was lower with samples from non-pregnant women. Furthermore, it has been proven that our sensor has a wide linear range of detection, as a sensitivity of 835.88 μA mIU-1 ml-2 cm-2 was attained, and the detection limit was 0.28 mIU/ml (27.78 pg/ml). The dissociation constant Kd of the specific antigen binding to the anti-hCG was calculated as 2.23 ± 0.66 mIU, and the maximum number of binding sites per antigen was Bmax = 22.54 ± 1.46 mIU. The sensing system shown here, with a narrow nanogap, is suitable for high-throughput POC diagnosis, and a single injection can obtain triplicate data or parallel analyses of different targets. PMID:26368287

  17. SU-E-T-574: Fessiblity of Using the Calypso System for HDR Interstitial Catheter Reconstruction

    SciTech Connect

    Li, J S; Ma, C

    2014-06-01

    Purpose: It is always a challenge to reconstruct the interstitial catheter for high dose rate (HDR) brachytherapy on patient CT or MR images. This work aims to investigate the feasibility of using the Calypso system (Varian Medical, CA) for HDR catheter reconstruction utilizing its accuracy on tracking the electromagnetic transponder location. Methods: Experiment was done with a phantom that has a HDR interstitial catheter embedded inside. CT scan with a slice thickness of 1.25 mm was taken for this phantom with two Calypso beacon transponders in the catheter. The two transponders were connected with a wire. The Calypso system was used to record the beacon transponders’ location in real time when they were gently pulled out with the wire. The initial locations of the beacon transponders were used for registration with the CT image and the detected transponder locations were used for the catheter path reconstruction. The reconstructed catheter path was validated on the CT image. Results: The HDR interstitial catheter was successfully reconstructed based on the transponders’ coordinates recorded by the Calypso system in real time when the transponders were pulled in the catheter. After registration with the CT image, the shape and location of the reconstructed catheter are evaluated against the CT image and the result shows an accuracy of 2 mm anywhere in the Calypso detectable region which is within a 10 cm X 10 cm X 10 cm cubic box for the current system. Conclusion: It is feasible to use the Calypso system for HDR interstitial catheter reconstruction. The obstacle for its clinical usage is the size of the beacon transponder whose diameter is bigger than most of the interstitial catheters used in clinic. Developing smaller transponders and supporting software and hardware for this application is necessary before it can be adopted for clinical use.

  18. Strain rate effects on the mechanical behavior of two Dual Phase steels in tension

    NASA Astrophysics Data System (ADS)

    Cadoni, E.; Singh, N. K.; Forni, D.; Singha, M. K.; Gupta, N. K.

    2016-05-01

    This paper presents an experimental investigation on the strain rate sensitivity of Dual Phase steel 1200 (DP1200) and Dual Phase steel 1400 (DP1400) under uni-axial tensile loads in the strain rate range from 0.001 s-1 to 600 s-1. These materials are advanced high strength steels (AHSS) having high strength, high capacity to dissipate crash energy and high formability. Flat sheet specimens of the materials having gauge length 10 mm, width 4 mm and thickness 2 mm (DP1200) and 1.25 mm (DP1400), are tested at room temperature (20∘C) on electromechanical universal testing machine to obtain their stress-strain relation under quasi-static condition (0.001 s-1), and on Hydro-Pneumatic machine and modified Hopkinson bar to study their mechanical behavior at medium (3 s-1, and 18 s-1) and high strain rates (200 s-1, 400 s-1, and 600 s-1) respectively. Tests under quasi-static condition are performed at high temperature (200∘C) also, and found that tensile flow stress is a increasing function of temperature. The stress-strain data has been analysed to determine the material parameters of the Cowper-Symonds and the Johnson-Cook models. A simple modification of the Johnson-Cook model has been proposed in order to obtain a better fit of tests at high temperatures. Finally, the fractographs of the broken specimens are taken by scanning electron microscope (SEM) to understand the fracture mechanism of these advanced high strength steels at different strain rates.

  19. Automated quantification of pulmonary emphysema from computed tomography scans: comparison of variation and correlation of common measures in a large cohort

    NASA Astrophysics Data System (ADS)

    Keller, Brad M.; Reeves, Anthony P.; Yankelevitz, David F.; Henschke, Claudia I.

    2010-03-01

    The purpose of this work was to retrospectively investigate the variation of standard indices of pulmonary emphysema from helical computed tomographic (CT) scans as related to inspiration differences over a 1 year interval and determine the strength of the relationship between these measures in a large cohort. 626 patients that had 2 scans taken at an interval of 9 months to 15 months (μ: 381 days, σ: 31 days) were selected for this work. All scans were acquired at a 1.25mm slice thickness using a low dose protocol. For each scan, the emphysema index (EI), fractal dimension (FD), mean lung density (MLD), and 15th percentile of the histogram (HIST) were computed. The absolute and relative changes for each measure were computed and the empirical 95% confidence interval was reported both in non-normalized and normalized scales. Spearman correlation coefficients are computed between the relative change in each measure and relative change in inspiration between each scan-pair, as well as between each pair-wise combination of the four measures. EI varied on a range of -10.5 to 10.5 on a non-normalized scale and -15 to 15 on a normalized scale, with FD and MLD showing slightly larger but comparable spreads, and HIST having a much larger variation. MLD was found to show the strongest correlation to inspiration change (r=0.85, p<0.001), and EI, FD, and HIST to have moderately strong correlation (r = 0.61-0.74, p<0.001). Finally, HIST showed very strong correlation to EI (r = 0.92, p<0.001), while FD showed the least strong relationship to EI (r = 0.82, p<0.001). This work shows that emphysema index and fractal dimension have the least variability overall of the commonly used measures of emphysema and that they offer the most unique quantification of emphysema relative to each other.

  20. Design and Construction of a Gamma Reaction History Diagnostic for the National Ignition Facility

    SciTech Connect

    R.M. Malone, B.C. Cox, B.C. Frogget, M.I. Kaufman, T.W. Tunnell; H.W. Herrmann, S.C. Evans, J.M. Mack, C.S. Young; W. Stoeffl

    2009-06-05

    Gas Cherenkov detectors have been used to convert fusion gammas into photons to achieve gamma reaction history (GRH) measurements. These gas detectors include a converter, pressurized gas volume, relay optics, and a photon detector. A novel design for the National Ignition Facility (NIF) using 90º Off-Axis Parabolic mirrors efficiently collects signal from fusion gammas with 8-ps time dispersion.1 Fusion gammas are converted to Compton electrons, which generate broadband Cherenkov light (our response is from 250 to 700 nm) in a pressurized gas cell. This light is relayed into a high-speed detector using three parabolic mirrors. The detector optics collect light from a 125-mm-diameter by 600-mm-long interchangeable gas (CO2 or SF6) volume. Because light is collected from source locations throughout the gas volume, the detector is positioned at the stop position rather than at an image position. The stop diameter and its position are independent of the light-generation locations along the gas cell. This design incorporates a fixed time delay that allows the detector to recover from prompt radiation. Optical ray tracings demonstrate how light can be collected from different angled trajectories of the Compton electrons as they traverse the gas volume. A Monte Carlo model of the conversion process from gammas to Cherenkov photons is used to generate photon trajectories. The collection efficiencies for different gamma energies are evaluated. At NIF, a cluster of four channels will allow for increased dynamic range, as well as different gamma energy thresholds. This GRH design is compared to a gas Cherenkov detector that utilizes a Cassegrain reflector now used at the OMEGA laser facility. 1. R. M. Malone, H. W. Herrmann, W. Stoeffl, J. M. Mack, C. S. Young, “Gamma bang time/reaction history diagnostics for the National Ignition Facility using 90º off-axis parabolic mirrors,” Rev. Sci. Instrum. 79, 10E532 (2008).

  1. Nigerian Population Research on Environment, Gene and Health (NIPREGH) – objectives and protocol

    PubMed Central

    Odili, Augustine N.; Ogedengbe, John O.; Nwegbu, Maxwell; Anumah, Felicia O.; Asala, Samuel; Staessen, Jan A

    2014-01-01

    Abstract Sub-Saharan Africa is currently undergoing an epidemiological transition from a disease burden largely attributable to communicable diseases to that resulting from a combination of both communicable and chronic non-communicable diseases. Data on chronic disease incidence, lifestyle, environmental and genetic risk factors are sparse in this region. This report aimed at providing relevant information in respect to risk factors that increase blood pressure and lead to development of intermediate cardiovascular phenotypes. We presented the rationale, objectives and key methodological features of the Nigerian Population Research on Environment, Gene and Health (NIPREGH) study. The challenges encountered in carrying out population study in this part of the world and the approaches at surmounting them were also presented. The preliminary data as at 20 November 2013 showed that out of the 205 individuals invited starting from early April 2013, 160 (72 women) consented and were enrolled; giving a response rate of 78%. Participants' age ranged from 18 to 80 years, with a mean (SD) of 39.8 (12.4) years and they were of 34 different ethnic groups spread over 24 states out of the 36 states that constitute Nigeria. The mean (SD) of office and home blood pressures were 113.0 (15.2) mm Hg systolic, 73.5 (12.5) mm Hg diastolic and 117.3 (15.0) mm Hg systolic, and 76.0 (9.6) mm Hg diastolic, respectively. Forty-three (26.8%) participants were hypertensive and 8 (5.0%) were diabetic. In addition to having the unique potential of recruiting a cohort that is a true representative of the entire Nigerian population, NIPREGH is feasible and the objectives realisable. PMID:25332707

  2. Antioxidant activity via DPPH, gram-positive and gram-negative antimicrobial potential in edible mushrooms.

    PubMed

    Ahmad, Nisar; Mahmood, Fazal; Khalil, Shahid Akbar; Zamir, Roshan; Fazal, Hina; Abbasi, Bilal Haider

    2014-10-01

    Edible mushrooms (EMs) are nutritionally rich source of proteins and essential amino acids. In the present study, the antioxidant activity via 1,1-diphenyl-2-picrylhydrazyl (DPPH) and antimicrobial potential in EMs (Pleurotus ostreatus, Morchella esculenta, P. ostreatus (Black), P. ostreatus (Yellow) and Pleurotus sajor-caju) were investigated. The DPPH radical scavenging activity revealed that the significantly higher activity (66.47%) was observed in Morchella esculenta at a maximum concentration. Similarly, the dose-dependent concentrations (200, 400, 600, 800 and 1000 µg) were also used for other four EMs. Pleurotus ostreatus exhibited 36.13% activity, P. ostreatus (Black (B)) exhibited 30.64%, P. ostreatus (Yellow (Y)) exhibited 40.75% and Pleurotus sajor-caju exhibited 47.39% activity at higher concentrations. Furthermore, the antimicrobial potential were investigated for its toxicity against gram-negative bacterial strains (Escherichia coli, Pseudomonas aeroginosa, Salmonella typhi, Klebsiella pneumonia, Erwinia carotovora and Agrobacterium tumifaciens), gram-positive bacterial strains (Bacillus subtilis, Bacillus atrophaeus and Staphylococcus aureus) and a fungal strain (Candida albicans) in comparison with standard antibiotics. Antimicrobial screening revealed that the ethanol extract of P. ostreatus was active against all microorganism tested except E. coli. Maximum zone of inhibition (13 mm) was observed against fungus and A. tumifaciens. P. sajor-caju showed best activities (12.5 mm) against B. subtilis, B. atrophaeus and K. pneumonia. P. ostreatus (Y) showed best activities against P. aeroginosa (21.83 mm), B. atrophaeus (20 mm) and C. albicans (21 mm). P. ostreatus (B) exhibited best activities against C. albicans (16 mm) and slightly lower activities against all other microbes except S. typhi. M. esculenta possess maximum activities in terms of inhibition zone against all microorganisms tested except S. typhi.

  3. SHERLOC: Scanning Habitable Environments With Raman & Luminescence for Organics & Chemicals, an Investigation for 2020

    NASA Astrophysics Data System (ADS)

    Beegle, L. W.; Bhartia, R.; DeFlores, L. P.; Asher, S. A.; Burton, A. S.; Clegg, S. M.; Conrad, P. G.; Edgett, K. S.; Ehlmann, B. L.; Langenhorst, F.; Fries, M.; Nealson, K. H.; Popp, J.; Sobron, P.; Steele, A.; Wiens, R. C.; Williford, K. H.

    2014-12-01

    The Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals SHERLOC investigation was recently selected for the Mars 2020 integrated payload. SHERLOC enables non-contact, spatially resolved, and highly sensitivity detection and characterization of organics and minerals in the Martian surface and near subsurface. SHERLOC is an arm-mounted, Deep UV (DUV) resonance Raman and fluorescence spectrometer utilizing a 248.6-nm DUV laser and 50 micron spot size. The laser is integrated to an autofocusing/scanning optical system, and co-boresighted to a context imager with a spatial resolution of 30 μm. SHERLOC operates over a 7 × 7 mm area through use of an internal scanning mirror. The 500 micron depth of view in conjunction with the MAHLI heritage autofocus mechanisms enables arm placements from 48 ±12.5 mm above natural or abraded surfaces without the need for rover arm repositioning/movement. Additionally, borehole interiors to a depth of ~25 mm, at angles from normal incidence to ±20 degrees, can be analyzed. Deep UV induced native fluorescence is very sensitive to condensed carbon and aromatic organics, enabling detection at or below 10-6 w/w (1 ppm) at <100 µm spatial scales. SHERLOC's deep UV resonance Raman enables detection and classification of aromatic and aliphatic organics with sensitivities of 10-2 to below 10-4 w/w at <50 µm spatial scales. In addition to organics, the deep UV Raman enables detection and classification of minerals relevant to aqueous chemistry with grain sizes below 20 µm grains. The instrument goals are to assess past aqueous history, detect the presence and preservation of potential biosignatures, and to support selection of return samples. To do this, SHERLOC will measure CHNOPS-containing mineralogy, measure the distribution and type of organics preserved at the surface, and correlate them to textural features.

  4. Thermal Stir Welding Development at Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    Ding, Robert J.

    2008-01-01

    Solid state welding processes have become the focus of welding process development at NASA's Marshall Space Flight Center. Unlike fusion weld processes such as tungsten inert gas (TIG), variable polarity plasma arc (VPPA), electron beam (EB), etc., solid state welding processes do not melt the material during welding. The resultant microstructure can be characterized as a dynamically recrystallized morphology much different than the casted, dentritic structure typical of fusion weld processes. The primary benefits of solid state processes over fusion weld processes include superior mechanic properties and the elimination of thermal distortion and residual stresses. These solid state processes attributes have profoundly influenced the direction of advanced welding research and development within the NASA agency. Thermal Stir Welding (TSW) is a new solid state welding process being developed at the Marshall Space Flight Center. Unlike friction stir welding, the heating, stirring and forging elements of the weld process can be decoupled for independent control. An induction coil induces energy into a workpiece to attain a desired plastic temperature. An independently controlled stir rod, captured within non-rotating containment plates, then stirs the plasticized material followed by forging plates/rollers that work the stirred weld joint. The independent control (decoupling) of heating, stirring and forging allows, theoretically, for the precision control of microstructure morphology. The TSW process is being used to evaluate the solid state joining of Haynes 230 for ARES J-2X applications. It is also being developed for 500-in (12.5 mm) thick commercially pure grade 2 titanium for navy applications. Other interests include Inconel 718 and stainless steel. This presentation will provide metallurgical and mechanical property data for these high melting temperature alloys.

  5. Ignition and flame characteristics of cryogenic hydrogen releases

    SciTech Connect

    Panda, Pratikash P.; Hecht, Ethan S.

    2017-01-01

    In this work, under-expanded cryogenic hydrogen jets were investigated experimentally for their ignition and flame characteristics. The test facility described herein, was designed and constructed to release hydrogen at a constant temperature and pressure, to study the dispersion and thermo-physical properties of cryogenic hydrogen releases and flames. In this study, a non-intrusive laser spark focused on the jet axis was used to measure the maximum ignition distance. The radiative power emitted by the corresponding jet flames was also measured for a range of release scenarios from 37 K to 295 K, 2–6 barabs through nozzles with diameters from 0.75 to 1.25 mm. The maximum ignition distance scales linearly with the effective jet diameter (which scales as the square root of the stagnant fluid density). A 1-dimensional (stream-wise) cryogenic hydrogen release model developed previously at Sandia National Laboratories (although this model is not yet validated for cryogenic hydrogen) was exercised to predict that the mean mole fraction at the maximum ignition distance is approximately 0.14, and is not dependent on the release conditions. The flame length and width were extracted from visible and infra-red flame images for several test cases. The flame length and width both scale as the square root of jet exit Reynolds number, as reported in the literature for flames from atmospheric temperature hydrogen. As shown in previous studies for ignited atmospheric temperature hydrogen, the radiative power from the jet flames of cold hydrogen scales as a logarithmic function of the global flame residence time. The radiative heat flux from jet flames of cold hydrogen is higher than the jet flames of atmospheric temperature hydrogen, for a given mass flow rate, due to the lower choked flow velocity of low-temperature hydrogen. Lastly, this study provides critical information with regard to the development of models to inform the safety codes and standards of hydrogen infrastructure.

  6. Ignition and flame characteristics of cryogenic hydrogen releases

    DOE PAGES

    Panda, Pratikash P.; Hecht, Ethan S.

    2017-01-01

    In this work, under-expanded cryogenic hydrogen jets were investigated experimentally for their ignition and flame characteristics. The test facility described herein, was designed and constructed to release hydrogen at a constant temperature and pressure, to study the dispersion and thermo-physical properties of cryogenic hydrogen releases and flames. In this study, a non-intrusive laser spark focused on the jet axis was used to measure the maximum ignition distance. The radiative power emitted by the corresponding jet flames was also measured for a range of release scenarios from 37 K to 295 K, 2–6 barabs through nozzles with diameters from 0.75 tomore » 1.25 mm. The maximum ignition distance scales linearly with the effective jet diameter (which scales as the square root of the stagnant fluid density). A 1-dimensional (stream-wise) cryogenic hydrogen release model developed previously at Sandia National Laboratories (although this model is not yet validated for cryogenic hydrogen) was exercised to predict that the mean mole fraction at the maximum ignition distance is approximately 0.14, and is not dependent on the release conditions. The flame length and width were extracted from visible and infra-red flame images for several test cases. The flame length and width both scale as the square root of jet exit Reynolds number, as reported in the literature for flames from atmospheric temperature hydrogen. As shown in previous studies for ignited atmospheric temperature hydrogen, the radiative power from the jet flames of cold hydrogen scales as a logarithmic function of the global flame residence time. The radiative heat flux from jet flames of cold hydrogen is higher than the jet flames of atmospheric temperature hydrogen, for a given mass flow rate, due to the lower choked flow velocity of low-temperature hydrogen. Lastly, this study provides critical information with regard to the development of models to inform the safety codes and standards of hydrogen infrastructure.« less

  7. Flooding after fire: Impacts of the 2013 Colorado Front Range floods on the High Park Fire burn scar

    NASA Astrophysics Data System (ADS)

    Kampf, S. K.; Schmeer, S.; MacDonald, L. H.; Brogan, D. J.; Nelson, P. A.

    2014-12-01

    In June 2012, the High Park Fire west of Fort Collins, CO burned 350 km2 of steep forested terrain, leading to elevated runoff and erosion in watersheds draining the burned area. Under the auspices of a NSF RAPID grant we began monitoring precipitation, hillslope-scale sediment production, stream stage, and channel geomorphic change in Skin Gulch and Hill Gulch, two 15 km2 watersheds within the High Park Fire. Short-duration summer thunderstorms are typically the dominant cause of post-fire runoff and erosion in the central and southern Rocky Mountains, but in September 2013 an extreme, long duration storm dropped more than 200 mm of rain in 48 hours. This storm provided a unique opportunity to compare the hydrologic and geomorphic effects of smaller summer thunderstorms to those of the long duration, high magnitude September event. Mean June-August 2013 precipitation in these watersheds was 125 mm, less than half the total for the September 2013 event, but this summer precipitation led to a mean sediment yield of 8 Mg ha-1, about double the mean sediment yield of the much larger September storm. Hillslope sediment production was highest during summer storms that were shorter duration but had higher 5-15 minute precipitation intensities than the September storm. These localized summer 2013 storms led to flashy pulses of flow in the channel network that caused relatively small amounts of channel aggradation or incision. In contrast, the September 2013 event produced sustained high flows that led to substantial geomorphic change throughout the channel network, with more than 2 m of aggradation at the outlet of Skin Gulch. These results indicate that the high intensity summer thunderstorms were most effective at mobilizing sediment from hillslopes, but the more spatially uniform rainfall during the September event produced much more dramatic downstream channel geomorphic change.

  8. Osteomalacia: The Missing Link in the Pathogenesis of Bisphosphonate-Related Osteonecrosis of the Jaws?

    PubMed Central

    Saia, Giorgia; Bettini, Giordana; Tronchet, Anita; Totola, Andrea; Bedogni, Giorgio; Tregnago, Paolo; Valenti, Maria Teresa; Bertoldo, Francesco; Ferronato, Giuseppe; Nocini, Pier Francesco; Blandamura, Stella; Dalle Carbonare, Luca

    2012-01-01

    Background. Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a well-documented adverse event from treatment with nitrogen-containing bisphosphonates (NBPs). During a preliminary histomorphometric study aimed at assessing the rate of bone remodeling in the jaws of patients with surgically resected BRONJ, we found a defect of bone mineralization (unpublished data). We hypothesized that osteomalacia could be a risk factor for BRONJ in patients taking NBPs. Therefore, we looked for static and dynamic histomorphometric evidence of osteomalacia in biopsies from subjects with and without BRONJ. Methods. This case-control study used histomorphometric analysis of bone specimens of patients using NBPs (22 patients with BRONJ and 21 patients without BRONJ) who required oral surgical interventions for the treatment/prevention of osteonecrosis. Patients were given tetracycline hydrochloride according to a standardized protocol before taking bone biopsies from their jaws. Biopsies with evidence of osteomyelitis or necrosis at histology were excluded from the study. Osteomalacia was defined as a mineralization lag time >100 days, a corrected mean osteoid thickness >12.5 mm, and an osteoid volume >10%. Results. In all, 77% of patients with BRONJ were osteomalacic compared with 5% of patients without BRONJ, according to histomorphometry. Because osteomalacia was found almost exclusively in NBP users with BRONJ, this is likely to be a generalized process in which the use of NBPs further deteriorates mechanisms of bone repair. Conclusions. Osteomalacia represents a new and previously unreported risk factor for disease development. This finding may contribute to a better understanding of the pathogenesis of this disease and help with the development of strategies to increase the safety of NBP administration. PMID:22723507

  9. Effects of short-term heated water-based exercise training on systemic blood pressure in patients with resistant hypertension: a pilot study.

    PubMed

    Guimarães, Guilherme V; Cruz, Lais G B; Tavares, Aline C; Dorea, Egidio L; Fernandes-Silva, Miguel M; Bocchi, Edimar A

    2013-12-01

    High blood pressure (BP) increases the risk of cardiovascular diseases, and its control is a clinical challenge. Regular exercise lowers BP in patients with mild-to-moderate hypertension. No data are available on the effects of heated water-based exercise in hypertensive patients. Our objective was to evaluate the effects of heated water-based exercise on BP in patients with resistant hypertension. We tested the effects of 60-min heated water-based exercise training three times per week in 16 patients with resistant hypertension (age 55±6 years). The protocol included walking and callisthenic exercises. All patients underwent 24-h ambulatory blood pressure monitoring (ABPM) before and after a 2-week exercise program in a heated pool. Systolic office BP was reduced from 162 to 144 mmHg (P<0.004) after heated-water training. After the heated-water exercise training during 24-h ABPM, systolic BP decreased from 135 to 123 mmHg (P=0.02), diastolic BP decreased from 83 to 74 mmHg (P=0.001), daytime systolic BP decreased from 141 to 125 mmHg (P=0.02), diastolic BP decreased from 87 to 77 mmHg (P=0.009), night-time systolic BP decreased from 128 to 118 mmHg (P=0.06), and diastolic BP decreased from 77 to 69 mmHg (P=0.01). In addition, BP cardiovascular load was reduced significantly during the 24-h daytime and night-time period after the heated water-based exercise. Heated water-based exercise reduced office BP and 24-h daytime and night-time ABPM levels. These effects suggest that heated water-based exercise may have a potential as a new therapeutic approach to resistant hypertensive patients.

  10. Two-dimensional optoacoustic tomography: transducer array and image reconstruction algorithm

    NASA Astrophysics Data System (ADS)

    Oraevsky, Alexander A.; Andreev, Valeri A.; Karabutov, Alexander A.; Esenaliev, Rinat O.

    1999-06-01

    Opto-acoustic tomography (OAT) utilizes laser pulses to create acoustic sources in tissue and wide-band detection of pressure profiles for the image reconstruction. A new laser optoacoustic imaging system (LOIS) for breast cancer detection and two-dimensional visualization is described. A Q-switched Nd:YAG laser was used for generation of opto-acoustic profiles in phantoms and tissues in vitro. Acoustic pulses were detected by a 12 element linear array of piezoelectric transducers. Each transducer was made of 0.5-mm thick PVDF slabs with dimensions of 4.3 mm X 12.5 mm. Signal-to-noise ratio was calculated and the sensitivity of optoacoustic system was evaluated. The axial (in-depth) resolution and the lateral resolution of the system were determined. The axial resolution of the receiving array was limited by its frequency band and was estimated to be approximately 1 mm. The lateral resolution was about 2.5 times the lateral dimension of the 'tumor' and defined by the finite aperture of the array and relatively large size of the single transducer. The time of full data acquisition was limited by the time allowed in clinical procedure of about 5 - 10 minutes. The procedure of signal processing is described. It includes high-pass signal filtering, compensation for acoustic diffraction, detection of the irradiated surface position and rejection of the reverberating signal. Radial back-projection algorithm for image reconstruction was developed and included in the computer code. Two-dimensional opto-acoustic images of simulated spheres and objects inside tissue phantoms are presented. The contrast of these images and limits of detection and localization of deeply embedded tumors are discussed.

  11. The Effect of Regular Intake of Dry-Cured Ham Rich in Bioactive Peptides on Inflammation, Platelet and Monocyte Activation Markers in Humans.

    PubMed

    Martínez-Sánchez, Sara María; Minguela, Alfredo; Prieto-Merino, David; Zafrilla-Rentero, María Pilar; Abellán-Alemán, José; Montoro-García, Silvia

    2017-03-23

    Background and aims: Dietary studies have shown that active biopeptides provide protective health benefits, although the mediating pathways are somewhat uncertain. To throw light on this situation, we studied the effects of consuming Spanish dry-cured ham on platelet function, monocyte activation markers and the inflammatory status of healthy humans with pre-hypertension. Methods: Thirty-eight healthy volunteers with systolic blood pressure of >125 mmHg were enrolled in a two-arm crossover randomized controlled trial. Participants received 80 g/day dry-cured pork ham of >11 months proteolysis or 100 g/day cooked ham (control product) for 4 weeks followed by a 2-week washout before "crossing over" to the other treatment for 4 more weeks. Soluble markers and cytokines were analyzed by ELISA. Platelet function was assessed by measuring P-selectin expression and PAC-1 binding after ADP (adenosine diphosphate) stimulation using whole blood flow cytometry. Monocyte markers of the pathological status (adhesion, inflammatory and scavenging receptors) were also measured by flow cytometry in the three monocyte subsets after the interventional period. Results: The mean differences between dry-cured ham and cooked ham followed by a time period adjustment for plasmatic P-selectin and interleukin 6 proteins slightly failed (p = 0.062 and p = 0.049, respectively), notably increased for MCP-1 levels (p = 0.023) while VCAM-1 was not affected. Platelet function also decreased after ADP stimulation. The expression of adhesion and scavenging markers (ICAM1R, CXCR4 and TLR4) in the three subsets of monocytes was significantly higher (all p < 0.05). Conclusions: The regular consumption of biopeptides contained in the dry-cured ham but absent in cooked ham impaired platelet and monocyte activation and the levels of plasmatic P-selectin, MCP-1 and interleukin 6 in healthy subjects. This study strongly suggests the existence of a mechanism that links dietary biopeptides and beneficial

  12. Variations of sediment size and size distribution along a river

    NASA Astrophysics Data System (ADS)

    Jan, C. D.; Tsai, Y. C.; Yang, S. Y.

    2015-12-01

    Sediment material of a river bed is an important factor for river morphodynamics. Typically, alluvial rivers construct their own geometries based on the sediment size and its distribution that affect the sediment transport capacity in river channel networks, involving the issues of watershed sediment yield, flood controls and the evolution of flood plain, habitats, deltas and adjacent coastline. Hence, investigating grain size and size distribution of sediment materials on riverbeds is important for practical river management and assessment of landscape evolution. In this study, we collected total 43 sediment samplings along the Koaping River in southern Taiwan to analyze the grain size and its distribution along the river. Spatial distributions of different representative grain sizes, such as D50 and D90, and the size corresponding Manning's n values are analyzed and discussed in this paper. An exponential grain size distribution (GSD) formula is used to explore the relation between the frequency and size of riverbed sediment. Results show that the grain size has a wide range distribution in the river upstream but displays a narrow-range variation in the river downstream. For example, the sediment medium size D50 ranges from 1.25 mm to 391.27 mm with an average of 49.36 mm in the upstream while it ranges from 0.135 mm to 0.625 mm with an average of 0.338 mm in the downstream. The best fitting curves of GSD with exponential scaling are analyzed with an empirical parameter Dc that is used to normalize the sediment grain size. This study finds that the empirical parameter Dc could be replaced by the sediment resentative size D65 (65% of sediment smaller than it). The results obtained herein could be useful not only in analyzing sediment transport of a river but also in river management.

  13. Accuracy of virtual models in the assessment of maxillary defects

    PubMed Central

    Kurşun, Şebnem; Kılıç, Cenk; Özen, Tuncer

    2015-01-01

    Purpose This study aimed to assess the reliability of measurements performed on three-dimensional (3D) virtual models of maxillary defects obtained using cone-beam computed tomography (CBCT) and 3D optical scanning. Materials and Methods Mechanical cavities simulating maxillary defects were prepared on the hard palate of nine cadavers. Images were obtained using a CBCT unit at three different fields-of-views (FOVs) and voxel sizes: 1) 60×60 mm FOV, 0.125 mm3 (FOV60); 2) 80×80 mm FOV, 0.160 mm3 (FOV80); and 3) 100×100 mm FOV, 0.250 mm3 (FOV100). Superimposition of the images was performed using software called VRMesh Design. Automated volume measurements were conducted, and differences between surfaces were demonstrated. Silicon impressions obtained from the defects were also scanned with a 3D optical scanner. Virtual models obtained using VRMesh Design were compared with impressions obtained by scanning silicon models. Gold standard volumes of the impression models were then compared with CBCT and 3D scanner measurements. Further, the general linear model was used, and the significance was set to p=0.05. Results A comparison of the results obtained by the observers and methods revealed the p values to be smaller than 0.05, suggesting that the measurement variations were caused by both methods and observers along with the different cadaver specimens used. Further, the 3D scanner measurements were closer to the gold standard measurements when compared to the CBCT measurements. Conclusion In the assessment of artificially created maxillary defects, the 3D scanner measurements were more accurate than the CBCT measurements. PMID:25793180

  14. Computer-assisted, Le Fort-based, face–jaw–teeth transplantation: a pilot study on system feasiblity and translational assessment

    PubMed Central

    Murphy, Ryan J.; Gordon, Chad R.; Basafa, Ehsan; Liacouras, Peter; Grant, Gerald T.

    2015-01-01

    Purpose Le Fort-based face–jaw–teeth transplantation (FJTT) attempts to marry bone and teeth geometry of size-mismatched face–jaw–teeth segments to restore function and form due to severe mid-facial trauma. Recent development of a computer-assisted planning and execution (CAPE) system for Le Fort-based FJTT in a pre-clinical swine model offers preoperative planning, and intraoperative navigation. This paper addresses the translation of the CAPE system to human anatomy and presents accuracy results. Methods Single-jaw, Le Fort-based FJTTs were performed on plastic models, one swine and one human, and on a human cadaver. Preoperative planning defined the goal placement of the donor’s Le Fort-based FJTT segment on the recipient. Patient-specific navigated cutting guides helped achieve planned osteotomies. Intraoperative cutting guide and donor fragment placement were compared with postoperative computed tomography (CT) data and the preoperative plan. Results Intraoperative measurement error with respect to postoperative CT was less than 1.25 mm for both mock transplants and 3.59 mm for the human cadaver scenario. Donor fragment placement (as compared to the planned position) was less accurate for the human model test case (2.91 mm) compared with the swine test (2.25 mm) and human cadaver (2.26 mm). Conclusion The results indicate the viability of the CAPE system for assisting with Le Fort-based FJTT and demonstrate the potential in human surgery. This system offers a new path forward to achieving improved outcomes in Le Fort-based FJTT and can be modified to assist with a variety of other surgeries involving the head, neck, face, jaws and teeth. PMID:25230895

  15. High-resolution 3-D T1*-mapping and quantitative image analysis of GRAY ZONE in chronic fibrosis.

    PubMed

    Pop, Mihaela; Ramanan, Venkat; Yang, Franklin; Zhang, Li; Newbigging, Susan; Ghugre, Nilesh R; Wright, Graham A

    2014-12-01

    The substrate of potentially lethal cardiac arrhythmias often resides in the gray zone (GZ), a mixture of viable myocytes and collagen strands found between healthy myocardium and infarct core (IC). The specific aims of this paper are to demonstrate correspondence between regions delineated in T1* (apparent T1) maps and tissue characteristics seen in histopathology and to determine the MR imaging resolution needed to adequately identify GZ-associated substrate in chronic infarct. For this, a novel 3-D multicontrast late enhancement (MCLE) MR method was used to image ex vivo swine hearts with chronic infarction, at high resolution ( 0.6×0.6×1.25 mm). Pixel-wise classified tissue maps were calculated using steady-state and T1* images as input to a fuzzy-clustering algorithm. Quantitative histology based on collagen stains was performed in n = 10 selected slabs and showed very good correlations between histologically-determined areas of heterogeneous and dense fibrosis, and the corresponding GZ ( R2 = 0.96) and IC ( R2 = 0.97 ) in tissue classified maps. Furthermore, in n = 24 slabs, we performed volumetric measurements of GZ and IC, at the original and decreased image resolutions. Our results demonstrated that the IC volume remained relatively unchanged across all resolutions, whereas the GZ volume progressively increased with diminished image resolution, with changes reaching significance at 1×1×5 mm resolution (p < 0.05 ) but not at 1×1×2.5 mm, suggesting that this resolution may be sufficient to adequately identify the GZ from MCLE images, enabling an effective MR probing of remodeled myocardium in late infarct. Future work will focus on translating these findings to optimizing the current in vivo MCLE imaging of the GZ.

  16. Effects of neighborhood socioeconomic status on blood pressure in older adults

    PubMed Central

    Wagner, Katia Jakovljevic Pudla; Boing, Antonio Fernando; Subramanian, SV; Höfelmann, Doroteia Aparecida; D’Orsi, Eleonora

    2016-01-01

    ABSTRACT OBJECTIVE To test if the neighborhood socioeconomic status is associated with systolic blood pressure and hypertension in older adults. METHODS A cross-sectional population-based study with a sample of 1,705 older adults from Florianópolis, SC, Southern Brazil. The contextual variable used was the average years of schooling of the head of the household in census tracts. Participants were considered hypertensive when the systolic blood pressure was ≥ 140 mmHg, diastolic ≥ 90 mmHg, or both. Additionally, the use of antihypertensive medication was also considered. Data were analyzed by using multilevel models of logistic and linear regression. RESULTS The average age of the sample was 70.7 years and the average of systolic and diastolic blood pressure was 133.5 mmHg (SD = 20.5 mmHg) and 81.9 mmHg (SD = 12.5 mmHg), respectively. The systolic blood pressure was 4.46 mmHg (95%CI 1.00–7.92) higher and the chance of hypertension was 1.80 (95%CI 1.26–2.57) among those who lived in census tracts with lower level of schooling. When the use of antihypertensive medication was combined with blood pressure levels, none association was found between the outcome and the level of schooling of the census tract. CONCLUSIONS Analytical models more robust (such as multilevel analysis) in Brazil are still little used, with a small number of articles published. Neighborhood socioeconomic status is associated with systolic blood pressure and the chance of hypertension, regardless of individual characteristics. PMID:28099662

  17. Prospective Trial of High-Dose Reirradiation Using Daily Image Guidance With Intensity-Modulated Radiotherapy for Recurrent and Second Primary Head-and-Neck Cancer

    SciTech Connect

    Chen, Allen M.; Farwell, D. Gregory; Luu, Quang; Cheng, Suzan; Donald, Paul J.; Purdy, James A.

    2011-07-01

    Purpose: To report a single-institutional experience using intensity-modulated radiotherapy with daily image-guided radiotherapy for the reirradiation of recurrent and second cancers of the head and neck. Methods and Materials: Twenty-one consecutive patients were prospectively treated with intensity-modulated radiotherapy from February 2006 to March 2009 to a median dose of 66 Gy (range, 60-70 Gy). None of these patients received concurrent chemotherapy. Daily helical megavoltage CT scans were obtained before each fraction as part of an image-guided radiotherapy registration protocol for patient alignment. Results: The 1- and 2-year estimates of in-field control were 72% and 65%, respectively. A total of 651 daily megavoltage CT scans were obtained. The mean systematic shift to account for interfraction motion was 1.38 {+-} 1.25 mm, 1.79 {+-} 1.45 mm, and 1.98 {+-} 1.75 mm for the medial-lateral, superior-inferior, and anterior-posterior directions, respectively. Pretreatment shifts of >3 mm occurred in 19% of setups in the medial-lateral, 27% in the superior-inferior, and 33% in the anterior-posterior directions, respectively. There were no treatment-related fatalities or hospitalizations. Complications included skin desquamation, odynophagia, otitis externa, keratitis, naso-lacrimal duct stenosis, and brachial plexopathy. Conclusions: Intensity-modulated radiotherapy with daily image guidance results in effective disease control with relatively low morbidity and should be considered for selected patients with recurrent and second primary cancers of the head and neck.

  18. Clinical Assessment of Standard and Generalized Autocalibrating Partially Parallel Acquisition Diffusion Imaging: Effects of Reduction Factor and Spatial Resolution

    PubMed Central

    Andre, J.B.; Zaharchuk, G.; Fischbein, N.J.; Augustin, M.; Skare, S.; Straka, M.; Rosenberg, J.; Lansberg, M.G.; Kemp, S.; Wijman, C.A.C.; Albers, G.W.; Schwartz, N.E.; Bammer, R.

    2012-01-01

    BACKGROUND AND PURPOSE PI improves routine EPI-based DWI by enabling higher spatial resolution and reducing geometric distortion, though it remains unclear which of these is most important. We evaluated the relative contribution of these factors and assessed their ability to increase lesion conspicuity and diagnostic confidence by using a GRAPPA technique. MATERIALS AND METHODS Four separate DWI scans were obtained at 1.5T in 48 patients with independent variation of in-plane spatial resolution (1.88 mm2 versus 1.25 mm2) and/or reduction factor (R = 1 versus R = 3). A neuroradiologist with access to clinical history and additional imaging sequences provided a reference standard diagnosis for each case. Three blinded neuroradiologists assessed scans for abnormalities and also evaluated multiple imaging-quality metrics by using a 5-point ordinal scale. Logistic regression was used to determine the impact of each factor on subjective image quality and confidence. RESULTS Reference standard diagnoses in the patient cohort were acute ischemic stroke (n = 30), ischemic stroke with hemorrhagic conversion (n = 4), intraparenchymal hemorrhage (n = 9), or no acute lesion (n = 5). While readers preferred both a higher reduction factor and a higher spatial resolution, the largest effect was due to an increased reduction factor (odds ratio, 47 ± 16). Small lesions were more confidently discriminated from artifacts on R = 3 images. The diagnosis changed in 5 of 48 scans, always toward the reference standard reading and exclusively for posterior fossa lesions. CONCLUSIONS PI improves DWI primarily by reducing geometric distortion rather than by increasing spatial resolution. This outcome leads to a more accurate and confident diagnosis of small lesions. PMID:22403781

  19. Compressive Strength and Water Absorption of Pervious Concrete that Using the Fragments of Ceramics and Roof Tiles

    NASA Astrophysics Data System (ADS)

    Prahara, E.; Meilani

    2014-03-01

    Pervious concrete was introduced in America in 2003, popularized by Dan Brown and used as a rigid pavement in the open parking lot. Rigid pavement using pervious concrete can absorb water in the surface to go straight through the concrete to the ground below.This water flow is one of the benefit of using the pervious concrete. Using of wastes such as broken roof and ceramics tiles are not commonly used in Indonesia. Utilization these kind of wastes is predicted lower the compressive strength of pervious concrete as they are used as a substitute for coarse aggregate.In this research, pervious concrete is made using a mixture of the fragment of ceramics and roof tiles.This research using broken ceramics and roof tiles with a grain size that loose from 38 mm sieve, retained on 19 mm sieve and the coarse aggregate from crushed stone that loose 12.5 mm sieve, retained on 9.5 mm sieve. The water cement ratio is 0.3 and to assist the mixing process, the addition of addictive in pervious concrete is used.The size of coarse aggregate used in the mixture affects the strength of pervious concrete. The larger the size of aggregate, the obtained compressive strength becomes smaller. It also affects the density of pervious concrete. The using of mixture of ceramics and roof tiles only reduce 2 MPa of pervious concrete compressive strength so this mixture can be used as a substitute for coarse aggregate with a maximum portion of 30 %. The high porosity of the specimens causes the reduction of pervious concrete density that affect the compressive strength. This high level of porosity can be seen from the high level of water absorption that exceed the required limit of water infiltration.

  20. A wind-driving disc model for the mm-wavelength polarization structure of HL Tau

    NASA Astrophysics Data System (ADS)

    Matsakos, Titos; Tzeferacos, Petros; Königl, Arieh

    2016-12-01

    The recent advent of spatially resolved mm- and cm-wavelength polarimetry in protostellar accretion discs could help clarify the role of magnetic fields in the angular momentum transport in these systems. The best case to date is that of HL Tau, where the inability to produce a good fit to the 1.25-mm data with a combination of vertical and azimuthal magnetic field components was interpreted as implying that centrifugally driven winds (CDWs) are probably not a significant transport mechanism on the ˜102 au scale probed by the observations. Using synthetic polarization maps of heuristic single-field-component discs and of a post-processed simulation of a wind-driving disc, we demonstrate that a much better fit to the data can be obtained if the radial field component, a hallmark of the CDW mechanism, dominates in the polarized emission region. A similar inference was previously made in modelling the far-infrared polarization map of the pc-scale dust ring in the Galactic Centre. To reconcile this interpretation with theoretical models of protostellar discs, which indicate that the wind is launched from a comparatively high elevation above the mid-plane, we propose that most of the polarized emission originates - with a high ( ≳ 10 per cent) intrinsic degree of polarization - in small ( ≲ 0.1 mm) grains that remain suspended above the mid-plane, and that the bulk of the mm-wavelength emission is produced - with low intrinsic polarization - by larger grains that have settled to the mid-plane.

  1. Comparison of advanced plasma sources for etching applications. V. Polysilicon etching rate, uniformity, profile control, and bulk plasma properties in a helical resonator plasma source

    SciTech Connect

    Lee, J.T.; Layadi, N.; Guinn, K.V.; Maynard, H.L.; Klemens, F.P.; Ibbotson, D.E.; Tepermeister, I.; Egan, P.O.; Richardson, R.A.

    1996-07-01

    Etching of polysilicon features using a helical resonator plasma source is evaluated. Performance metrics consist of etching rate, etching rate uniformity, and profile control using HBr/O{sub 2}{endash}He gas-phase chemistry. The effect of source power, rf-bias power, and reactor pressure on etching rate and uniformity is examined using a response surface experiment. Feature profile control is determined by examining nested and isolated lines and trenches using oxide mask/polysilicon/oxide structures. Good uniformity and vertical profiles are obtained at low reactor pressures, high source power, and rf-bias between 50 and 60 W. The operating point for best uniformity is at 3.5 mTorr, 3000 W source power, and 53 W rf-bias power. At this point, the etching rate is 3700 A/min and the nonuniformity is less than 1.0{percent}, over 125-mm-diam wafers. Radial profiles of electron temperature and ion density near the wafer surface are presented as a function of source power, rf-bias power, and reactor pressure. The ion density was found to be in the mid-10{sup 11} cm{sup {minus}3} range and electron temperatures were 5{endash}7 eV. An increase in source power and reactor pressure results in an increase in ion density; however, the electron temperature shows a weaker dependence. Finally, these results are compared to those using helicon and multipole electron cyclotron resonance plasma sources evaluated in previous studies. We found that all three plasma sources provide high ion density at low pressures to meet performance demands for polysilicon etching; however, the helical resonator source offers somewhat higher etching rate and better bulk plasma uniformity. {copyright} {ital 1996 American Vacuum Society}

  2. The VetMousetrap: a device for computed tomographic imaging of the thorax of awake cats.

    PubMed

    Oliveira, Cintia R; Ranallo, Frank N; Pijanowski, Gerald J; Mitchell, Mark A; O'Brien, Mauria A; McMichael, Maureen; Hartman, Susan K; Matheson, Jodi S; O'Brien, Robert T

    2011-01-01

    The VetMousetrap, a novel device that allows computed tomography (CT) of awake cats and provides a clinically supportive environment, is described. Ten normal cats were used to test the device for ambient internal oxygen, carbon dioxide levels, and temperature. Twenty-two awake normal cats were imaged using a 16-multislice helical CT unit to evaluate dose-equivalent protocols. Two different X-ray tube potentials (kV), 80 and 120, and two different helical pitches, 0.562 and 1.75, were evaluated. The signal intensity of the pulmonary parenchyma (SIlung), signal intensity of background (SIbackgr), contrast, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were calculated. Three evaluators ranked the images for sharpness of liver margins, motion, helical, and windmill artifacts. CT was successfully completed in 20 of 22 cats. No artifacts directly related to the device were detected. Overall, 75 of 80 (94%) examinations were judged to have absent or minimal motion artifact. A statistically significant difference was found for SNR (P = 0.001) and CNR (P = 0.001) between all protocols. The higher pitch protocols had significantly lower noise and higher SNR and CNR, lower motion artifact but greater helical artifacts. A protocol using 80 kV, 130 mA, 0.5s, and 0.562 pitch with 1.25mm slice thickness, and 0.625 mm slice reconstruction interval is recommended. The VetMousetrap appears to provide the opportunity for diagnostic CT imaging of the thorax of awake cats.

  3. Improved Electromagnetic Shielding Performance of Lightweight Compression Molded Polypyrrole/Ferrite Composite Sheets

    NASA Astrophysics Data System (ADS)

    Varshney, Swati; Dhawan, S. K.

    2017-03-01

    An attempt has been made to design lightweight polypyrrole/carbon fibers and polypyrrole/carbon fibers/ferrofluid (Fe3O4 particles) composite sheets using novolac resin via compression molding for electromagnetic shielding applications. The optimized formulation has been achieved to get an excellent combination of thermal, mechanical, and electrical properties of the composite sheet. Structural and morphological studies were carried out by x-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. Polypyrrole/carbon fibers composite sheets shows maximum flexural strength and a flexural modulus of 62.4 ± 1 MPa and 0.60 ± 0.02 GPa, respectively, with total shielding effectiveness of 22.8 dB in the Ku-band (12.4-18 GHz) but when ferrofluid is added to the polypyrrole/carbon fibers composite system, flexural strength increases to 92.3 ± 1 MPa and the same trend has been observed for flexural modulus with a value of 0.65 ± 0.04 GPa. This multiphase lightweight polypyrrole composite sheet having 34 vol.% of carbon fibers and 4 vol.% of Fe3O4 nanoparticles offers total shielding effectiveness of 31.9 dB (>99.99% attenuation) in the Ku-band (12.4-18 GHz) frequency range with a thickness of ˜1.25 mm. This is accredited to high dielectric losses and magnetic losses in conducting composite sheets. The observed results suggest that lightweight compression molded polypyrrole composite sheets could be a potential commercial alternative for electromagnetic shielding applications.

  4. Effects of Prostate-Rectum Separation on Rectal Dose From External Beam Radiotherapy

    SciTech Connect

    Susil, Robert C.; McNutt, Todd R.; DeWeese, Theodore L.; Song, Danny

    2010-03-15

    Purpose: In radiotherapy for prostate cancer, the rectum is the major dose-limiting structure. Physically separating the rectum from the prostate (e.g., by injecting a spacer) can reduce the rectal radiation dose. Despite pilot clinical studies, no careful analysis has been done of the risks, benefits, and dosimetric effects of this practice. Methods and Materials: Using cadaveric specimens, 20 mL of a hydrogel was injected between the prostate and rectum using a transperineal approach. Imaging was performed before and after spacer placement, and the cadavers were subsequently dissected. Ten intensity-modulated radiotherapy plans were generated (five before and five after separation), allowing for characterization of the rectal dose reduction. To quantify the amount of prostate-rectum separation needed for effective rectal dose reduction, simulations were performed using nine clinically generated intensity-modulated radiotherapy plans. Results: In the cadaveric studies, an average of 12.5 mm of prostate-rectum separation was generated with the 20-mL hydrogel injections (the seminal vesicles were also separated from the rectum). The average rectal volume receiving 70 Gy decreased from 19.9% to 4.5% (p < .05). In the simulation studies, a prostate-rectum separation of 10 mm was sufficient to reduce the mean rectal volume receiving 70 Gy by 83.1% (p <.05). No additional reduction in the average rectal volume receiving 70 Gy was noted after 15 mm of separation. In addition, spacer placement allowed for increased planning target volume margins without exceeding the rectal dose tolerance. Conclusion: Prostate-rectum spacers can allow for reduced rectal toxicity rates, treatment intensification, and/or reduced dependence on complex planning and treatment delivery techniques.

  5. Ignition and flame characteristics of [under-expanded] cryogenic hydrogen releases

    DOE PAGES

    Panda, Pratikash P.; Hecht, Ethan S.

    2016-09-04

    In this work, under-expanded cryogenic hydrogen jets were investigated experimentally for their ignition and flame characteristics. The test facility described herein, was designed and constructed to release hydrogen at a constant temperature and pressure, to study the dispersion and thermo-physical properties of cryogenic hydrogen releases and flames. In this study, a non-intrusive laser spark focused on the jet axis was used to measure the maximum ignition distance. The radiative power emitted by the corresponding jet flames was also measured for a range of release scenarios from 37 K to 295 K, 2–6 barabs through nozzles with diameters from 0.75 tomore » 1.25 mm. The maximum ignition distance scales linearly with the effective jet diameter (which scales as the square root of the stagnant fluid density). A 1-dimensional (stream-wise) cryogenic hydrogen release model developed previously at Sandia National Laboratories (although this model is not yet validated for cryogenic hydrogen) was exercised to predict that the mean mole fraction at the maximum ignition distance is approximately 0.14, and is not dependent on the release conditions. The flame length and width were extracted from visible and infra-red flame images for several test cases. The flame length and width both scale as the square root of jet exit Reynolds number, as reported in the literature for flames from atmospheric temperature hydrogen. As shown in previous studies for ignited atmospheric temperature hydrogen, the radiative power from the jet flames of cold hydrogen scales as a logarithmic function of the global flame residence time. The radiative heat flux from jet flames of cold hydrogen is higher than the jet flames of atmospheric temperature hydrogen, for a given mass flow rate, due to the lower choked flow velocity of low-temperature hydrogen. Lastly, this study provides critical information with regard to the development of models to inform the safety codes and standards of hydrogen infrastructure.« less

  6. Imaging of ancient Egyptian mummies' temporal bones with digital volume tomography.

    PubMed

    Dalchow, C V; Schmidt, C; Harbort, J; Knecht, R; Grzyska, U; Muenscher, A

    2012-10-01

    The radiographic imaging of ancient Egyptian mummies has always been of great interest. Computed tomography is the method of choice to demonstrate bony pathologies with high quality. As digital volume tomography (DVT) is an extension of panoramic tomography with a very high resolution, its qualities were evaluated by examination of temporal bones of Egyptian mummy skulls. Ten Egyptian mummy skulls from the Zoological Collection Marburg, estimated 1,700-5,000 years of age, from Abydos, Philae, Theben-West and Sakkarah, were examined by DVT (3D Accuitomo, Morita, Japan). Through a rotation 360° of the X-ray source around the region of interest, a cylinder of 3 × 4 cm was captured as a three-dimensional volume. The gained data were analyzed with the help of special software on a PC. The angles of the axial, coronal and sagittal sections were arbitrarily changed to represent single structures with high resolution of 0.125 mm to analyze specific anatomical structures. In all skulls, conditions of the temporal bone and its anatomical structures were evaluated and normal as well as pathological findings evaluated in detail. The analysis of special landmarks such as the ossicular chain, cochlea, external, and internal auditory canal, facial nerve canal, and semicircular canals showed an intact ossicular chain in six temporal bones, while only isolated and dislocated ossicles were found in eight temporal bones. Besides one dehiscence of the superior semicircular canal in one temporal bone which might have led to vertigo and deafness at lifetime, all other findings were normal. Fragments of foreign bodies additionally found in the labyrinth, external ear canal and intracranially were attributed to postmortem damage. Digital volume tomography extends the imaging possibilities of CT for paleoradiological evaluation of temporal bones. With its high resolution, geometric accuracy, reconstruction capabilities, rapidness, and comparably low costs, even small bony pathologies are

  7. RAINBOWS and CERAMBOWS: The Technologies of Pre-Stressed Piezo Actuators

    NASA Technical Reports Server (NTRS)

    Haertling, Gene H.

    1996-01-01

    Amplified mechanical displacement effects, similar to those observed in the recently reported Rainbow actuators, have also been found to exist in prestressed ceramic/metal composite structures coined as CERAMBOW's - an acronym for CERamic And Metal Biased Oxide Wafer. Mimicking the Rainbows in many ways, the intentionally created internal compressive and tensile stresses within the Cerambows are used to amplify their displacement properties via the combined effects of piezoelectric d31 strain and domain reorientation. They are fabricated from ferroelectric, piezoelectric or electrostrictive materials and metal substrates of significantly different thermal expansions which are largely responsible for the creation of the stress. Typical ceramics used in Cerambows are PZT, PLZT, PBZT, PSZT and PMN and some typical metal substrates are Al, Ag, Ni, brass, steel and Be/Cu foil. Shapes can vary from round disks to square plates and rectangular bars. Formed at an elevated temperature of approximately 250 C, the stresses on cooling to room temperature are generally sufficient to produce displacements as large as 0.125mm (5 mils) when activated unipolar and 0.25mm (10 mils) when operated bipolar at 450 volts in a dome mode. Comparing equal structures of a Cerambow with a Rainbow, the Cerambow was found to achieve approximately 70% of the displacement that would normally be obtained with a Rainbow. Although this difference in displacement is sufficient to prefer a Rainbow for many applications, there are some advantages for the Cerambow. Among these are (1) the processing temperatures are lower, (2) high lead-containing ceramics are not required and (3) in some instances the metal substrate is more convenient to interface with other elements of a device. However, the disadvantages include (1) lower displacement in the dome mode of operation, (2) the higher displacement saddle mode has not yet been demonstrated with a Cerambow and (3) the ceramic/metal bond interface is a

  8. Thermophysical properties of BKC 44306 and BKC 44307 PMDI urethane solid and foams

    SciTech Connect

    Bauer, Stephen J.; Flint, Gregory Mark; Urquhart, Alexander; Mondy, Lisa Ann

    2014-02-01

    Accurate knowledge of thermophysical properties of urethane foam is considered extremely important for meaningful models and analyses to be developed of scenarios wherein the foam is heated. Its performance at temperature requires a solid understanding of the foam material properties at temperature. Also, foam properties vary with density/porosity. An experimental program to determine the thermal properties of the two foams and their parent solid urethane was developed in order to support development of a predictive model relating density and thermal properties from first principles. Thermal properties (thermal conductivity, diffusivity, and specific heat) of the foam were found to vary with temperatures from 26°C to 90°C. Thermal conductivity generally increases with increasing temperature for a given initial density and ranges from .0433 W/mK at 26°C to .0811 W/mK at 90°C; thermal diffusivity generally decreases with increasing temperature for a given initial density and ranges from .4101 mm2/s at 26°C to .1263 mm2/s at 90°C; and specific heat generally increases with increasing temperature for a given initial density and ranges from .1078 MJ/m3K at 26°C to .6323 MJ/m3K at 90°C. Thermal properties of the solid urethane were also found to vary with temperatures from 26°C to 90°C. Average thermal conductivity generally increases with increasing temperature for a given initial density and ranges from 0.126 to 0.131 W/mK at 26°C to 0.153 to 0.157 W/mK at 90°C; average thermal diffusivity generally decreases with increasing temperature for a given initial density and ranges from 0.142 to 0.147 mm2/s at 26°C to 0.124 to 0.125 mm2/s at 90°C; and average specific heat generally increases with increasing temperature for a given initial density and ranges from 0.889 to 0.899 MJ/m3K to 1.229 to 1.274 MJ/m3K at 90°C. The density of both foam and solid urethane decreased

  9. SU-C-BRF-01: Correlation of DIBH Breath Hold Amplitude with Dosimetric Sparing of Heart and Left Anterior Descending Artery in Left Breast Radiotherapy

    SciTech Connect

    Kim, Taeho; Reardon, Kelli; Sukovich, Kaitlyn; Crandley, Edwin; Read, Paul; Krishni, Wijesooriya

    2014-06-15

    Purpose: A 7.4% increase in major coronary events per 1 Gy increase in mean heart dose has been reported from the population-based analysis of radiation-induced cardiac toxicity following treatment of left sided breast cancer. Deep inhalation breath-hold (DIBH) is clinically utilized to reduce radiation dose to heart and left anterior descending artery (LAD). We investigated the correlation of dose sparing in heart and LAD with internal DIBH amplitude to develop a quantitative predictive model for expected dose to heart and LAD based on internal breath hold amplitude. Methods: A treatment planning study (Prescription Dose = 50 Gy) was performed on 50 left breast cancer patients underwent DIBH whole breast radiotherapy. Two CT datasets, free breathing (FB) and DIBH, were utilized for treatment planning and for determination of the internal anatomy DIBH amplitude (difference between sternum position at FB and DIBH). The heart and LAD dose between FB and DIBH plans was compared and dose to the heart and LAD as a function of breath hold amplitude was determined. Results: Average DIBH amplitude using internal anatomy was 13.9±4.2 mm. The DIBH amplitude-mean dose reduction correlation is 20%/5mm (0.3 Gy/5mm) for the heart and 18%/5mm (1.1 Gy/5mm) for LAD. The correlation with max dose reduction is 12%/5mm (3.8 Gy/5mm) for the heart and 16%/5mm (3.2 Gy/5mm) for LAD. We found that average dose reductions to LAD from 6.0±6.5 Gy to 2.0±1.6 Gy with DIBH (4.0 Gy reduction: -67%, p < 0.001) and average dose reduction to the heart from 1.3±0.7 Gy to 0.7±0.2 Gy with DIBH (0.6 Gy reduction: -46%, p < 0.001). That suggests using DIBH may reduce the risk of the major coronary event for left sided breast cancer patients. Conclusion: The correlation between breath hold amplitude and dosimetric sparing suggests that dose sparing linearly increases with internal DIBH amplitude.

  10. Determination of degradation rates of organic substances in the unsaturated soil zone depending on the grain size fractions of various soil types

    NASA Astrophysics Data System (ADS)

    Fichtner, Thomas; Stefan, Catalin; Goersmeyer, Nora

    2015-04-01

    Rate and extent of the biological degradation of organic substances during transport through the unsaturated soil zone is decisively influenced by the chemical and physical properties of the pollutants such as water solubility, toxicity and molecular structure. Furthermore microbial degradation processes are also influenced by soil-specific properties. An important parameter is the soil grain size distribution on which the pore volume and the pore size depends. Changes lead to changes in air and water circulation as well as preferred flow paths. Transport capacity of water inclusive nutrients is lower in existing bad-drainable fine pores in soils with small grain size fractions than in well-drainable coarse pores in a soil with bigger grain size fractions. Because fine pores are saturated with water for a longer time than the coarse pores and oxygen diffusion in water is ten thousand times slower than in air, oxygen is replenished much slower in soils with small grain size fractions. As a result life and growth conditions of the microorganisms are negatively affected. This leads to less biological activity, restricted degradation/mineralization of pollutants or altered microbial processes. The aim of conducted laboratory column experiments was to study the correlation between the grain size fractions respectively pore sizes, the oxygen content and the biodegradation rate of infiltrated organic substances. Therefore two columns (active + sterile control) were filled with different grain size fractions (0,063-0,125 mm, 0,2-0,63 mm and 1-2 mm) of soils. The sterile soil was inoculated with a defined amount of a special bacteria culture (sphingobium yanoikuae). A solution with organic substances glucose, oxalic acid, sinaphylic alcohol and nutrients was infiltrated from the top in intervals. The degradation of organic substances was controlled by the measurement of dissolved organic carbon in the in- and outflow of the column. The control of different pore volumes

  11. Use of bovine follicular fluid to increase ovulation rate or prevent ovulation in sheep.

    PubMed

    Henderson, K M; Prisk, M D; Hudson, N; Ball, K; McNatty, K P; Lun, S; Heath, D; Kieboom, L E; McDiarmid, J

    1986-03-01

    Romney ewes were injected intramuscularly once or twice daily for 3 days with 0, 0.1, 0.5, 1 or 5 ml of bovine follicular fluid (bFF) treated with dextran-coated charcoal, starting immediately after injection of cloprostenol to initiate luteolysis on Day 10 of the oestrous cycle. There was a dose-related suppression of plasma concentrations of FSH, but not LH, during the treatment period. On stopping the bFF treatment, plasma FSH concentrations 'rebounded' to levels up to 3-fold higher than pretreatment values. The mean time to the onset of oestrus was also increased in a dose-related manner by up to 11 days. The mean ovulation rates of ewes receiving 1.0 ml bFF twice daily (1.9 +/- 0.2 ovulations/ewe, mean +/- s.e.m. for N = 34) or 5.0 ml once daily (2.0 +/- 0.2 ovulations/ewe, N = 25) were significantly higher than that of control ewes (1.4 +/- 0.1 ovulations/ewe, N = 35). Comparison of the ovaries of ewes treated with bFF for 24 or 48 h with the ovaries of control ewes revealed no differences in the number or size distribution of antral follicles. However, the large follicles (greater than or equal to 5 mm diam.) of bFF-treated ewes had lower concentrations of oestradiol-17 beta in follicular fluid, contained fewer granulosa cells and the granulosa cells had a reduced capacity to aromatize testosterone to oestradiol-17 beta and produce cyclic AMP when challenged with FSH or LH. No significant effects of bFF treatment were observed in small (1-2.5 mm diam.) or medium (3-4.5 mm diam.) sized follicles. Ewes receiving 5 ml bFF once daily for 27 days, from the onset of luteolysis, were rendered infertile during this treatment period. Oestrus was not observed and ovulation did not occur. Median concentrations of plasma FSH fell to 20% of pretreatment values within 2 days. Thereafter they gradually rose over the next 8 days to reach 60% of pretreatment values where they remained for the rest of the 27-day treatment period. Median concentrations of plasma LH increased during the treatment period to levels up to 6-fold higher than pretreatment values. When bFF treatment was stopped, plasma concentrations of FSH and LH quickly returned to control levels, and oestrus was observed within 2 weeks. The ewes were mated at this first oestrus and each subsequently delivered a single lamb.

  12. Development of a Compact Rectenna for Wireless Powering of a Head-Mountable Deep Brain Stimulation Device

    PubMed Central

    Kouzani, Abbas Z.; Tye, Susannah J.; Abulseoud, Osama A.; Amiet, Andrew; Galehdar, Amir; Kaynak, Akif; Berk, Michael

    2014-01-01

    Design of a rectangular spiral planar inverted-F antenna (PIFA) at 915 MHz for wireless power transmission applications is proposed. The antenna and rectifying circuitry form a rectenna, which can produce dc power from a distant radio frequency energy transmitter. The generated dc power is used to operate a low-power deep brain stimulation pulse generator. The proposed antenna has the dimensions of 10 mm \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$\\times\\,$ \\end{document}12.5 mm \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$\\times\\,$ \\end{document}1.5 mm and resonance frequency of 915 MHz with a measured bandwidth of 15 MHz at return loss of \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}${-}{\\rm 10}~{\\rm dB}$ \\end{document}. A dielectric substrate of FR-4 of \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$\\varepsilon _{r}=4.8$ \\end{document} and \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$\\delta=0.015$ \\end{document} with thickness of 1.5 mm is used for both antenna and rectifier circuit simulation and fabrication because of its availability and low cost. An L-section impedance matching circuit is used between the PIFA and voltage doubler rectifier. The impedance matching circuit also works as a low-pass filter for elimination of higher order harmonics. Maximum dc voltage at the rectenna output is 7.5 V in free space and this rectenna can drive a deep brain stimulation pulse generator at a distance of 30 cm from a radio frequency energy transmitter, which transmits power of 26.77 dBm. PMID:27170863

  13. Lutetium oxyorthosilicate block detector readout by avalanche photodiode arrays for high resolution animal PET.

    PubMed

    Pichler, B J; Swann, B K; Rochelle, J; Nutt, R E; Cherry, S R; Siegel, S B

    2004-09-21

    Avalanche photodiodes (APDs) have proven to be useful as light detectors for high resolution positron emission tomography (PET). Their compactness makes these devices excellent candidates for replacing bulky photomultiplier tubes (PMTs) in PET systems where space limitations are an issue. The readout of densely packed, 10 x 10 lutetium oxyorthosilicate (LSO) block detectors (crystal size 2.0 x 2.0 x 12 mm3) with custom-built monolithic 3 x 3 APD arrays was investigated. The APDs had a 5 x 5 mm2 active surface and were arranged on a 6.25 mm pitch. The dead space on the edges of the array was 1.25 mm. The APDs were operated at a bias voltage of approximately 380 V for a gain of 100 and a dark current of 10 nA per APD. The standard deviation in gain between the APDs in the array ranged from 1.8 to 6.5% as the gain was varied from 50 to 108. A fast, low-noise, multi-channel charge sensitive preamplifier application-specific integrated circuit (ASIC) was developed for the APD readout. The amplifier had a rise time of 8 ns, a noise floor of 515 e- rms and a 9 e- pF(-1) noise slope. An acquired flood image showed that all 100 crystals from the block detector could be resolved. Timing measurements with single-channel LSO-APD detectors, as well as with the array, against a plastic scintillator and PMT assembly showed a time resolution of 1.2 ns and 2.5 ns, respectively. The energy resolution measured with a single 4.0 x 4.0 x 10 mm3 LSO crystal, wrapped in four-layer polytetrafluoroethylene (PTFE) tape and coupled with optical grease on a single APD of the array, yielded 15% (full width at half maximum, FWHM) at 511 keV. Stability tests over 9 months of operation showed that the APD arrays do not degrade appreciably. These results demonstrate the ability to decode densely packed LSO scintillation blocks with compact APD arrays. The good timing and energy resolution makes these detectors suitable for high resolution PET.

  14. Visual Field Map Clusters in High-Order Visual Processing: Organization of V3A/V3B and a New Cloverleaf Cluster in the Posterior Superior Temporal Sulcus.

    PubMed

    Barton, Brian; Brewer, Alyssa A

    2017-01-01

    The cortical hierarchy of the human visual system has been shown to be organized around retinal spatial coordinates throughout much of low- and mid-level visual processing. These regions contain visual field maps (VFMs) that each follows the organization of the retina, with neighboring aspects of the visual field processed in neighboring cortical locations. On a larger, macrostructural scale, groups of such sensory cortical field maps (CFMs) in both the visual and auditory systems are organized into roughly circular cloverleaf clusters. CFMs within clusters tend to share properties such as receptive field distribution, cortical magnification, and processing specialization. Here we use fMRI and population receptive field (pRF) modeling to investigate the extent of VFM and cluster organization with an examination of higher-level visual processing in temporal cortex and compare these measurements to mid-level visual processing in dorsal occipital cortex. In human temporal cortex, the posterior superior temporal sulcus (pSTS) has been implicated in various neuroimaging studies as subserving higher-order vision, including face processing, biological motion perception, and multimodal audiovisual integration. In human dorsal occipital cortex, the transverse occipital sulcus (TOS) contains the V3A/B cluster, which comprises two VFMs subserving mid-level motion perception and visuospatial attention. For the first time, we present the organization of VFMs in pSTS in a cloverleaf cluster. This pSTS cluster contains four VFMs bilaterally: pSTS-1:4. We characterize these pSTS VFMs as relatively small at ∼125 mm(2) with relatively large pRF sizes of ∼2-8° of visual angle across the central 10° of the visual field. V3A and V3B are ∼230 mm(2) in surface area, with pRF sizes here similarly ∼1-8° of visual angle across the same region. In addition, cortical magnification measurements show that a larger extent of the pSTS VFM surface areas are devoted to the peripheral

  15. Factors Influencing Watershed Average Erosion Rates Calculated from Reservoir Sedimentation in Eastern USA

    NASA Astrophysics Data System (ADS)

    Ahamed, A.; Snyder, N. P.; David, G. C.

    2014-12-01

    The Reservoir Sedimentation Database (ResSed), a catalogue of reservoirs and depositional data that has recently become publically available, allows for rapid calculation of sedimentation rates and rates of capacity loss over short (annual to decadal) timescales. This study is a statistical investigation of factors controlling watershed average erosion rates (E) in eastern United States watersheds. We develop an ArcGIS-based model that delineates watersheds upstream of ResSed dams and calculate drainage areas to determine E for 191 eastern US watersheds. Geomorphic, geologic, regional, climatic, and land use variables are quantified within study watersheds using GIS. Erosion rates exhibit a large amount of scatter, ranging from 0.001 to 1.25 mm/yr. A weak inverse power law relationship between drainage area (A) and E (R2 = 0.09) is evident, similar to other studies (e.g. Milliman and Syvitski, 1992; Koppes and Montgomery, 2009). Linear regressions reveal no relationship between mean watershed slope (S) and E, possibly due to the relatively low relief of the region (mean S for all watersheds is 6°). Analysis of Variance shows that watersheds in formerly glaciated regions exhibit a statistically significant lower mean E (0.06 mm/year) than watersheds in unglaciated regions (0.12 mm/year), but that watersheds with different dam purposes show no significant differences in mean E. Linear regressions reveal no relationships between E and land use parameters like percent agricultural land and percent impervious surfaces (I), but classification and regression trees indicate that watersheds in highly developed regions (I > 34%) exhibit mean E (0.36 mm/year) that is four times higher than watersheds in less developed (I < 34%) regions (0.09 mm/year). Further, interactions between land use variables emerge in formerly glaciated regions, where increased agricultural land results in higher rates of annual capacity loss in reservoirs (R2 = 0.56). Plots of E versus timescale of measurement (e.g., Sadler and Jerolmack, 2014) show that nearly the full range of observed E, including the highest values, are seen over short survey intervals (< 20 years), suggesting that whether or not large sedimentation events (such as floods) occur between two surveys may explain the high degree of variability in measured rates.

  16. Mechanical properties of all-suture anchors for rotator cuff repair

    PubMed Central

    Zargar, N.; Smith, R. D. J.; Carr, A. J.

    2017-01-01

    Objectives All-suture anchors are increasingly used in rotator cuff repair procedures. Potential benefits include decreased bone damage. However, there is limited published evidence for the relative strength of fixation for all-suture anchors compared with traditional anchors. Materials and Methods A total of four commercially available all-suture anchors, the ‘Y-Knot’ (ConMed), Q-FIX (Smith & Nephew), ICONIX (Stryker) and JuggerKnot (Zimmer Biomet) and a traditional anchor control TWINFIX Ultra PK Suture Anchor (Smith & Nephew) were tested in cadaveric human humeral head rotator cuff repair models (n = 24). This construct underwent cyclic loading applied by a mechanical testing rig (Zwick/Roell). Ultimate load to failure, gap formation at 50, 100, 150 and 200 cycles, and failure mechanism were recorded. Significance was set at p < 0.05. Results Overall, mean maximum tensile strength values were significantly higher for the traditional anchor (181.0 N, standard error (se) 17.6) compared with the all-suture anchors (mean 133.1 N se 16.7) (p = 0.04). The JuggerKnot anchor had greatest displacement at 50, 100 and 150 cycles, and at failure, reaching statistical significance over the control at 100 and 150 cycles (22.6 mm se 2.5 versus 12.5 mm se 0.3; and 29.6 mm se 4.8 versus 17.0 mm se 0.7). Every all-suture anchor tested showed substantial (> 5 mm) displacement between 50 and 100 cycles (6.2 to 14.3). All-suture anchors predominantly failed due to anchor pull-out (95% versus 25% of traditional anchors), whereas a higher proportion of traditional anchors failed secondary to suture breakage. Conclusion We demonstrate decreased failure load, increased total displacement, and variable failure mechanisms in all-suture anchors, compared with traditional anchors designed for rotator cuff repair. These findings will aid the surgeon’s choice of implant, in the context of the clinical scenario. Cite this article: N. S. Nagra, N. Zargar, R. D. J. Smith, A. J. Carr. Mechanical properties of all-suture anchors for rotator cuff repair. Bone Joint Res 2017;6:82–89. DOI: 10.1302/2046-3758.62.BJR-2016-0225.R1 PMID:28167489

  17. SU-E-J-172: A Quantitative Assessment of Lung Tumor Motion Using 4DCT Imaging Under Conditions of Controlled Breathing in the Management of Non-Small Cell Lung Cancer (NSCLC) Using Stereotactic Body Radiation Therapy (SBRT)

    SciTech Connect

    Mohatt, D; Gomez, J; Singh, A; Malhotra, H

    2014-06-01

    Purpose: To study breathing related tumor motion amplitudes by lung lobe location under controlled breathing conditions used in Stereotactic Body Radiation Therapy (SBRT) for NSCLC. Methods: Sixty-five NSCLC SBRT patients since 2009 were investigated. Patients were categorized based on tumor anatomic location (RUL-17, RML-7, RLL-18, LUL-14, LLL-9). A 16-slice CT scanner [GE RT16 Pro] along with Varian Realtime Position Management (RPM) software was used to acquire the 4DCT data set using 1.25 mm slice width. Images were binned in 10 phases, T00 being at maximum inspiration ' T50 at maximum expiration phase. Tumor volume was segmented in T50 using the CT-lung window and its displacement were measured from phase to phase in all three axes; superiorinferior, anterior-posterior ' medial-lateral at the centroid level of the tumor. Results: The median tumor movement in each lobe was as follows: RUL= 3.8±2.0 mm (mean ITV: 9.5 cm{sup 3}), RML= 4.7±2.8 mm (mean ITV: 9.2 cm{sup 3}), RLL=6.6±2.6 mm (mean ITV: 12.3 cm{sup 3}), LUL=3.8±2.4 mm (mean ITV: 18.5 cm{sup 3}), ' LLL=4.7±2.5 mm (mean ITV: 11.9 cm{sup 3}). The median respiratory cycle for all patients was found to be 3.81 ± 1.08 seconds [minimum 2.50 seconds, maximum 7.07 seconds]. The tumor mobility incorporating breathing cycle was RUL = 0.95±0.49 mm/s, RML = 1.35±0.62 mm/s, RLL = 1.83±0.71 mm/s, LUL = 0.98 ±0.50 mm/s, and LLL = 1.15 ±0.53 mm/s. Conclusion: Our results show that tumor displacement is location dependent. The range of motion and mobility increases as the location of the tumor nears the diaphragm. Under abdominal compression, the magnitude of tumor motion is reduced by as much as a factor of 2 in comparison to reported tumor magnitudes under conventional free breathing conditions. This study demonstrates the utility of abdominal compression in reducing the tumor motion leading to reduced ITV and planning tumor volumes (PTV)

  18. Design and performance evaluation of a 20-aperture multipinhole collimator for myocardial perfusion imaging applications

    NASA Astrophysics Data System (ADS)

    Bowen, Jason D.; Huang, Qiu; Ellin, Justin R.; Lee, Tzu-Cheng; Shrestha, Uttam; Gullberg, Grant T.; Seo, Youngho

    2013-10-01

    Single photon emission computed tomography (SPECT) myocardial perfusion imaging remains a critical tool in the diagnosis of coronary artery disease. However, after more than three decades of use, photon detection efficiency remains poor and unchanged. This is due to the continued reliance on parallel-hole collimators first introduced in 1964. These collimators possess poor geometric efficiency. Here we present the performance evaluation results of a newly designed multipinhole collimator with 20 pinhole apertures (PH20) for commercial SPECT systems. Computer simulations and numerical observer studies were used to assess the noise, bias and diagnostic imaging performance of a PH20 collimator in comparison with those of a low energy high resolution (LEHR) parallel-hole collimator. Ray-driven projector/backprojector pairs were used to model SPECT imaging acquisitions, including simulation of noiseless projection data and performing MLEM/OSEM image reconstructions. Poisson noise was added to noiseless projections for realistic projection data. Noise and bias performance were investigated for five mathematical cardiac and torso (MCAT) phantom anatomies imaged at two gantry orbit positions (19.5 and 25.0 cm). PH20 and LEHR images were reconstructed with 300 MLEM iterations and 30 OSEM iterations (ten subsets), respectively. Diagnostic imaging performance was assessed by a receiver operating characteristic (ROC) analysis performed on a single MCAT phantom; however, in this case PH20 images were reconstructed with 75 pixel-based OSEM iterations (four subsets). Four PH20 projection views from two positions of a dual-head camera acquisition and 60 LEHR projections were simulated for all studies. At uniformly-imposed resolution of 12.5 mm, significant improvements in SNR and diagnostic sensitivity (represented by the area under the ROC curve, or AUC) were realized when PH20 collimators are substituted for LEHR parallel-hole collimators. SNR improves by factors of 1.94-2.34 for the five patient anatomies and two orbital positions studied. For the ROC analysis the PH20 AUC is larger than the LEHR AUC with a p-value of 0.0067. Bias performance, however, decreases with the use of PH20 collimators. Systematic analyses showed PH20 collimators present improved diagnostic imaging performance over LEHR collimators, requiring only collimator exchange on existing SPECT cameras for their use.

  19. SU-E-T-150: End to End Tests On the First Clinical EDGETM

    SciTech Connect

    Scheib, S; Schmelzer, P; Vieira, S; Greco, C

    2014-06-01

    Purpose: To quantify the sub millimeter overall accuracy of EDGETM, the dedicated linac based SRS/SABR treatment platform from Varian, using a novel End-to-End (E2E) test phantom. Methods: The new E2E test phantom developed by Varian consists of a cube with an outer dimension of 15x15x15 cm3. The phantom is equipped with an exchangable inner cube (7×7×7 cm3) to hold radiochromic films or a tungsten ball (diameter = 5 mm) for Winston-Lutz tests. 16 ceramic balls (diameter = 5 mm) are embedded in the outer cube. Three embedded Calypso transponders allow for Calypso based monitoring. The outer surface of the phantom is tracked using the Optical Surface Monitoring System (OSMS). The phantom is positioned using kV, MV and CBCT images. A simCT of the phantom was acquired and SRS/SABR plans were treated using the new phantom on the first clinical installed EDGETM. As a first step a series of EPID based Winston-Lutz tests have been performed. As a second step the calculated dose distribution applied to the phantom was verified with radiochromic films in orthogonal planes. The measured dose distribution is compared with the calculated (Eclipse) one based on the known isocenter on both dose distributions. The geometrical shift needed to match both dose distributions is the overall accuracy and is determined using dose profiles, isodose lines or gamma pass rates (3%, 1 mm). Results: Winston-Lutz tests using the central tungsten BB demonstrated a targeting accuracy of 0.44±0.18mm for jaw (2cm × 2cm) defined 0.39±0.19mm for MLC (2cm × 2cm) defined and 0.37±0.15mm for cone (12.5 mm) defined fields. A treated patient plan (spinal metastases lesion with integrated boost) showed a dosimetric dose localization accuracy of 0.6mm. Conclusion: Geometric and dosimetric E2E tests on EDGETM, show sub-millimeter E2E targeting and dose localisation accuracy.

  20. Risk assessment of physiological effects of atmospheric composition and pressure in Constellation vehicles

    NASA Astrophysics Data System (ADS)

    Scheuring, Richard; Conkin, Johnny; Jones, Jeffrey A.; Gernhardt, Michael L.

    Introduction: To limit the risk of fire and reduce denitrogenation time to prevent decompression sickness to support frequent extravehicular activities on the Moon, a hypobaric (PB=414mmHg) and mildly hypoxic ( ppO2=132mmHg, 32% O2-68%N2) living environment is considered for the Crew Exploration Vehicle (CEV) and Lunar Surface Access Module (LSAM). With acute change in ppO2 from 145-178mmHg at standard vehicular operating pressure to less than 125mmHg at desired lunar surface vehicular operating pressures, there is the possibility that some crewmembers may develop symptoms of Acute Mountain Sickness (AMS). The signs and symptoms of AMS (headache plus nausea, dizziness, fatigue, or sleeplessness) could impact crew health and performance on lunar surface missions. Methods: We performed a literature review on the topic of the physiological effects of reduced ppO2 and absolute pressure. The results of nine studies were evaluated. Results: There is evidence for an absolute pressure effect per se on AMS, so the higher the altitude for a given hypoxic alveolar oxygen (O2) partial pressure (PAO2), the greater the AMS response is. Between 7% and 25% of adults may experience mild AMS near 2000 m altitude following a rapid ascent from sea level while breathing air (6500 ft, acute PAO2=75mmHg). The operational experience with the Shuttle staged denitrogenation protocol at 528mmHg (3048 m) while breathing 26.5% O2 (acute PAO2=85mmHg) in astronauts adapting to microgravity suggests a similar likely experience in the proposed CEV environment. Conclusions: We believe the risk of mild AMS is greater given a PAO2 of 77mmHg at 4876 m altitude while breathing 32% O2 than at 1828 m altitude while breathing 21% O2. Only susceptible astronauts would develop mild and transient AMS with prolonged exposure to 414 mmHg (4876 m) while breathing 32% O2 (acute PAO2=77mmHg). So the following may be employed for operational risk reduction: (1) develop procedures to increase PB as needed in the

  1. Potential effect of CAD systems on the detection of actionable nodules in chest CT scans during routine reporting

    NASA Astrophysics Data System (ADS)

    Wormanns, Dag; Beyer, Florian; Butzbach, Arnauld; Zierott, Livia; Heindel, Walter

    2006-03-01

    The purpose of the presented study was to determine the impact of two different CAD systems used as concur-rent reader for detection of actionable nodules (>4 mm) on the interpretation of chest CT scans during routine reporting. Fifty consecutive MDCT scans (1 mm or 1.25 mm slice thickness, 0.8 mm reconstruction increment) were se-lected from clinical routine. All cases were read by a resident and a staff radiologist, and a written report was available in the radiology information system (RIS). The RIS report mentioned at least one actionable pulmonary nodule in 18 cases (50%) and did not report any pulmonary nodule in the remaining 32 cases. Two different recent CAD systems were independently applied to the 50 CT scans as concurrent reader with two radiologists: Siemens LungCare NEV and MEDIAN CAD-Lung. Two radiologists independently reviewed the CAD results and determined if a CAD result was a true positive or a false positive finding. Patients were classified into two groups: in group A if at least one actionable nodule was detected and in group B if no actionable nodules were found. The effect of CAD on routine reporting was simulated as set union of the findings of routine reporting and CAD thus applying CAD as concurrent reader. According to the RIS report group A (patients with at least one actionable nodule) contained 18 cases (36% of all 50 cases), and group B contained 32 cases. Application of a CAD system as concurrent reader resulted in detec-tion of additional CT scans with actionable nodules and reclassification into group A in 16 resp. 18 cases (radi-ologist 1 resp. radiologist 2) with Siemens NEV and in 19 resp. 18 cases with MEDIAN CAD-Lung. In seven cases MEDIAN CAD-Lung and in four cases Siemens NEV reclassified a case into group A while the other CAD system missed the relevant finding. Sensitivity on a nodule (>4 mm) base was .45 for Siemens NEV and .55 for MEDIAN CAD-Lung; the difference was not yet significant (p=.077). In our study use of CAD as second reader in routine reporting doubled the percentage of patients with actionable nodules larger than 4 mm.

  2. TU-CD-207-12: Impact of Anatomical Noise On Detection Performance of Microcalcifications in Multi-Contrast Breast Imaging

    SciTech Connect

    Garrett, J; Ge, Y; Li, K; Chen, G

    2015-06-15

    Purpose: The anatomical noise power spectra (NPS) for differential phase contrast (DPC) and dark field (DF) imaging have recently been characterized using a power-law model with two parameters, alpha and beta, an innovative extension to the methodology used in x-ray attenuation based breast imaging such as mammography, DBT, or cone-beam CT. Beta values of 3.6, 2.6, and 1.3 have been measured for absorption, DPC, and DF respectively for cadaver breasts imaged in the coronal plane; these dramatic differences should be reflected in their detection performance. The purpose of this study was to determine the impact of anatomical noise on breast calcification detection and compare the detection performance of the three contrast mechanisms of a multi-contrast x-ray imaging system. Methods: In our studies, a calcification image object was segmented out of the multi-contrast images of a cadaver breast specimen. 50 measured total NPS were measured from breast cadavers directly. The ideal model observer detectability was calculated for a range of doses (5–100%) and a range of calcification sizes (diameter = 0.25–2.5 mm). Results: Overall we found the highest average detectability corresponded to DPC imaging (7.4 for 1 mm calc.), with DF the next highest (3.8 for 1 mm calc.), and absorption the lowest (3.2 for 1 mm calc.). However, absorption imaging also showed the slowest dependence on dose of the three modalities due to the significant anatomical noise. DPC showed a peak detectability for calcifications ∼1.25 mm in diameter, DF showed a peak for calcifications around 0.75 mm in diameter, and absorption imaging had no such peak in the range explored. Conclusion: Understanding imaging performance for DPC and DF is critical to transition these modalities to the clinic. The results presented here offer new insight into how these modalities complement absorption imaging to maximize the likelihood of detecting early breast cancers. J. Garrett, Y. Ge, K. Li: Nothing to disclose. G.-H. Chen: Research funded, GE Healthcare; Research funded, Siemens AX.

  3. Destruction of a Holothuria scabra population by overfishing at Abu Rhamada Island in the Red Sea.

    PubMed

    Hasan, Mohamed Hamza

    2005-10-01

    males) to 155 mm for females and 125 mm for males in January 2003. There was a positive relationship between fecundity and size. And oocyte/female was highest in 1999 (0.73-1.7 million) and 2000 (0.75-1.72 million), decreased during 2001 (0.2-0.85 million) to reach its minimum at 2002 (0.28-0.29 million).

  4. Battery-operated, argon-hydrogen microplasma on hybrid, postage stamp-sized plastic-quartz chips for elemental analysis of liquid microsamples using a portable optical emission spectrometer.

    PubMed

    Weagant, Scott; Chen, Vivian; Karanassios, Vassili

    2011-11-01

    A battery-operated, atmospheric pressure, self-igniting, planar geometry Ar-H(2) microplasma for elemental analysis of liquid microsamples is described. The inexpensive microplasma device (MPD) fabricated for this work was a hybrid plastic-quartz structure that was formed on chips with an area (roughly) equal to that of a small-sized postage stamp (MPD footprint, 12.5-mm width by 38-mm length). Plastic substrates were chosen due to their low cost, for rapid prototyping purposes, and for a speedy microplasma device evaluation. To enhance portability, the microplasma was operated from an 18-V rechargeable battery. To facilitate portability even further, it was demonstrated that the battery can be recharged by a portable solar panel. The battery-supplied dc voltage was converted to a high-voltage ac. The ~750-μm (diameter) and 12-mm (long) Ar-H(2) (3% H(2)) microplasma was formed by applying the high-voltage ac between two needle electrodes. Spectral interference from the electrode materials or from the plastic substrate was not observed. Operating conditions were found to be key to igniting and sustaining a microplasma that was simply "warm" to the touch (thus alleviating the need for cooling or other thermal management) and that had a stable background emission. A small-sized (900 μL internal volume) electrothermal vaporization system (40-W max power) was used for microsample introduction. Microplasma background emission in the spectral region between 200 and 850 nm obtained using a portable fiber-optic spectrometer is reported and the effect of the operating conditions is described. Analyte emission from microliter volumes of dilute single-element standard solutions of Cd, Cu, K, Li, Mg, Mn, Na, Pb, and Zn is documented. The majority of spectral lines observed for the elements tested were from neutral atoms. The relative lack of emission from ion lines simplified the spectra, thus facilitating the use of a portable spectrometer. Despite the relative spectral simplicity, some spectral interference effects were noted when running a multi-element solution. An example of how interference in the spectral domain can be resolved in the time domain using selective thermal vaporization is provided. Analytical utility and performance characteristics are reported; for example, K concentrations in diluted (~30 times) bottled water were determined to be 4.1 ± 1.0 μg/mL (4 μg/mL was the stated concentration), precision was about 25%, and the estimated detection limits were in the picogram range (or in nanograms per milliliter in relative units).

  5. GPS Velocity Field at the Western Tip of the Aden Ridge ; Implications for Rifting and the Arabia-Somalia-Nubia Triple Junction Dynamics

    NASA Astrophysics Data System (ADS)

    Doubre, C.; Socquet, A.; Masson, F.; Cressot, C.; Mohamed, K.; Vigny, C.; Ruegg, J.

    2010-12-01

    Due to the presence of magma and a complex thermal structure, the dynamics of divergent plate boundaries are complicated, with microseismicity (ML<4) contributing very little to the total moment release. For the last 35 years several geodetic campaigns have been conducted at the western tip of the Aden Ridge propagating on land into Afar (Republic of Djibouti). The first segment above water, the Asal Rift, experienced a seismo-volcanic event in 1978, which was the first rifting episode, along with the 1978-1985 Icelandic Krafla event, to be monitored by terrestrial geodetic measurements. These measurements revealed the opening of two 1-2 m-wide dykes in the rift inner floor. Since then, terrestrial and spatial geodetic monitoring shows that the rift kept opening, during the post-rifting period, at a rate largely exceeding the plates’ motions. This significant opening rate is decreasing with time to tend, three decades after the rifting event, to the far-field opening rate. We present here the results of the GPS measurements of a 45 site network covering the Tadjoura-Asal Rift System, previously made every two years from 1995 to 2003, and repeated in 2010. The calculated 1999-2010 horizontal velocity field is very homogeneous with a quasi-constant N045° direction with respect to Somalia and a regular increase from the southern to the northern margin of the Asal Rift clearly controlled by a few normal faults, and reaching a maximum of 12.5 mm/yr. A non-negligible part of the Arabia-Somalia divergent movement (1 to 2 mm/yr) is observed south of this rift, which sheds light on the role of the active normal faults bounding the asymmetrical Gaggadé Basin and therefore brings important constraints on the location of the Red Sea Ridge-Aden Ridge-East African Rift triple junction. Since the last 2003 campaign, the lack of micro-seismicity within the Asal Rift seems to be associated with a ˜2 mm/yr decrease of the opening rate deduced from the GPS time series analysis. These results confirm the importance of non-steady state behavior of the Asal volcano-tectonic rift segment, and the role of geothermal/volcanic activity on the occurrence of transients, as suggested by InSAR results.

  6. Visual Field Map Clusters in High-Order Visual Processing: Organization of V3A/V3B and a New Cloverleaf Cluster in the Posterior Superior Temporal Sulcus

    PubMed Central

    Barton, Brian; Brewer, Alyssa A.

    2017-01-01

    The cortical hierarchy of the human visual system has been shown to be organized around retinal spatial coordinates throughout much of low- and mid-level visual processing. These regions contain visual field maps (VFMs) that each follows the organization of the retina, with neighboring aspects of the visual field processed in neighboring cortical locations. On a larger, macrostructural scale, groups of such sensory cortical field maps (CFMs) in both the visual and auditory systems are organized into roughly circular cloverleaf clusters. CFMs within clusters tend to share properties such as receptive field distribution, cortical magnification, and processing specialization. Here we use fMRI and population receptive field (pRF) modeling to investigate the extent of VFM and cluster organization with an examination of higher-level visual processing in temporal cortex and compare these measurements to mid-level visual processing in dorsal occipital cortex. In human temporal cortex, the posterior superior temporal sulcus (pSTS) has been implicated in various neuroimaging studies as subserving higher-order vision, including face processing, biological motion perception, and multimodal audiovisual integration. In human dorsal occipital cortex, the transverse occipital sulcus (TOS) contains the V3A/B cluster, which comprises two VFMs subserving mid-level motion perception and visuospatial attention. For the first time, we present the organization of VFMs in pSTS in a cloverleaf cluster. This pSTS cluster contains four VFMs bilaterally: pSTS-1:4. We characterize these pSTS VFMs as relatively small at ∼125 mm2 with relatively large pRF sizes of ∼2–8° of visual angle across the central 10° of the visual field. V3A and V3B are ∼230 mm2 in surface area, with pRF sizes here similarly ∼1–8° of visual angle across the same region. In addition, cortical magnification measurements show that a larger extent of the pSTS VFM surface areas are devoted to the peripheral

  7. Determination of and compensation for wafer bow and warp in a scanning electron microscope requiring precise feature locating and variable tilt

    NASA Astrophysics Data System (ADS)

    Holmes, Duane C.

    1990-06-01

    Precise and accurate feature positioning in SEMs is becoming more critical. Moving the stage to a predetermined location must be done with accuracy and precision that put the feature ofinterest in the field ofview at a magnification high enough to detect orrecognize the same feature. Ifthis is notdone, some sort ofsearch, either automatic ormanual must be performed. This may not only be bothersome, but detrimental to inspection or measurement throughput performance. Ultra precise stages - for example, those using laser interferometers or linear encoders - are capable of positioning precisions, if not accuracies, to 0. 1 micron. In both optical and SEM systems where inspection is normal to the plane ofthe waler(cailed zero tilt), precise locating of features is possible without serious attention being paid to the bow or warp of a wafer. From the SEMI Standards Manuals, it is seen that a 200 mm wafer may have up to 65 microns of bow. In optical lithography tools and optical inspection or measurement systems, a vacuum chuck may alter or reduce the bow. However, in the vacuum chamber of the SEM this technique does not work. The bow or warp remains. The problem occurs in going to a particular numerical address whenthe waferis tilted, ifthat numerical address was determined at some different tilt -themost probable, of course, being zero iilt. Tilting of the wafer will cause the initially observed feature to move through an arc of "unknown" extent (unknown because it is a function of the bow and the bow is not known at that point). A 60 degree tilt of awafer with 40 microns of bow can cause about 35 microns oflaten.l displacement of a feature from where it would be expected for a wafer with no bow. The effect of this displacement on detectability is discussed. Actual displacement measurements on a 125 mm wafer ait plotted. These plots are compared with those derived from measurements made by optical and SEM systems specially set up to measure bow magnitudes. Bow

  8. Dose variations caused by setup errors in intracranial stereotactic radiotherapy: A PRESAGE study

    SciTech Connect

    Teng, Kieyin; Gagliardi, Frank; Alqathami, Mamdooh; Ackerly, Trevor; Geso, Moshi

    2014-01-01

    Stereotactic radiotherapy (SRT) requires tight margins around the tumor, thus producing a steep dose gradient between the tumor and the surrounding healthy tissue. Any setup errors might become clinically significant. To date, no study has been performed to evaluate the dosimetric variations caused by setup errors with a 3-dimensional dosimeter, the PRESAGE. This research aimed to evaluate the potential effect that setup errors have on the dose distribution of intracranial SRT. Computed tomography (CT) simulation of a CIRS radiosurgery head phantom was performed with 1.25-mm slice thickness. An ideal treatment plan was generated using Brainlab iPlan. A PRESAGE was made for every treatment with and without errors. A prescan using the optical CT scanner was carried out. Before treatment, the phantom was imaged using Brainlab ExacTrac. Actual radiotherapy treatments with and without errors were carried out with the Novalis treatment machine. Postscan was performed with an optical CT scanner to analyze the dose irradiation. The dose variation between treatments with and without errors was determined using a 3-dimensional gamma analysis. Errors are clinically insignificant when the passing ratio of the gamma analysis is 95% and above. Errors were clinically significant when the setup errors exceeded a 0.7-mm translation and a 0.5° rotation. The results showed that a 3-mm translation shift in the superior-inferior (SI), right-left (RL), and anterior-posterior (AP) directions and 2° couch rotation produced a passing ratio of 53.1%. Translational and rotational errors of 1.5 mm and 1°, respectively, generated a passing ratio of 62.2%. Translation shift of 0.7 mm in the directions of SI, RL, and AP and a 0.5° couch rotation produced a passing ratio of 96.2%. Preventing the occurrences of setup errors in intracranial SRT treatment is extremely important as errors greater than 0.7 mm and 0.5° alter the dose distribution. The geometrical displacements affect dose delivery to the tumor and the surrounding normal tissues.

  9. Dose variations caused by setup errors in intracranial stereotactic radiotherapy: a PRESAGE study.

    PubMed

    Teng, Kieyin; Gagliardi, Frank; Alqathami, Mamdooh; Ackerly, Trevor; Geso, Moshi

    2014-01-01

    Stereotactic radiotherapy (SRT) requires tight margins around the tumor, thus producing a steep dose gradient between the tumor and the surrounding healthy tissue. Any setup errors might become clinically significant. To date, no study has been performed to evaluate the dosimetric variations caused by setup errors with a 3-dimensional dosimeter, the PRESAGE. This research aimed to evaluate the potential effect that setup errors have on the dose distribution of intracranial SRT. Computed tomography (CT) simulation of a CIRS radiosurgery head phantom was performed with 1.25-mm slice thickness. An ideal treatment plan was generated using Brainlab iPlan. A PRESAGE was made for every treatment with and without errors. A prescan using the optical CT scanner was carried out. Before treatment, the phantom was imaged using Brainlab ExacTrac. Actual radiotherapy treatments with and without errors were carried out with the Novalis treatment machine. Postscan was performed with an optical CT scanner to analyze the dose irradiation. The dose variation between treatments with and without errors was determined using a 3-dimensional gamma analysis. Errors are clinically insignificant when the passing ratio of the gamma analysis is 95% and above. Errors were clinically significant when the setup errors exceeded a 0.7-mm translation and a 0.5° rotation. The results showed that a 3-mm translation shift in the superior-inferior (SI), right-left (RL), and anterior-posterior (AP) directions and 2° couch rotation produced a passing ratio of 53.1%. Translational and rotational errors of 1.5mm and 1°, respectively, generated a passing ratio of 62.2%. Translation shift of 0.7mm in the directions of SI, RL, and AP and a 0.5° couch rotation produced a passing ratio of 96.2%. Preventing the occurrences of setup errors in intracranial SRT treatment is extremely important as errors greater than 0.7mm and 0.5° alter the dose distribution. The geometrical displacements affect dose delivery to the tumor and the surrounding normal tissues.

  10. The 3D distribution of cordierite and biotite in hornfels from the Bugaboo contact aureole (British Columbia, Canada)

    NASA Astrophysics Data System (ADS)

    Gaidies, Fred; Petley-Ragan, Arianne; Pattison, David

    2016-04-01

    The size, abundance, shape and spatial distribution of metamorphic minerals bears important information on the rates and mechanisms of fundamental processes that take place during metamorphic crystallization. X-ray computed tomography (XR-CT) has become the method of choice to study the three-dimensional (3D) disposition of minerals in rocks as it allows investigation of relatively large sample volumes at sufficiently high resolution required for statistically meaningful analyses, and as its non-destructive fashion permits further studies such as mineral chemical, isotopic or crystallographic analyses of select grains identified through XR-CT. We present results obtained through the quantification of the 3D disposition of cordierite and biotite crystals in a hornfels from the contact aureole of the Bugaboo Batholith (British Columbia, Canada) using XR-CT and global as well as scale-dependent pattern statistics (Petley-Ragan et al., 2016). The results demonstrate a random distribution of cordierite and biotite crystal sizes for all scales across the entire rock volume studied indicative of interface-controlled prograde metamorphic reaction kinetics. We show that the common approach to approximate the shape of crystals as spherical underestimates the influence of the Strauss hard-core process on rock texture which may be misinterpreted to reflect ordering of crystal sizes by inhibition of nucleation and growth commonly associated with diffusion-controlled reaction kinetics. According to our findings, Strauss hard-core ordering develops at length scales equal to and less than the average major axis of the crystal population. This is significantly larger than what is obtained if a spherical crystal geometry would be assumed, and increases with deviation from sphericity. For the cordierite and biotite populations investigated in this research, Strauss hard-core ordering developed at length scales of up to ˜2.2 and 1.25 mm, respectively, which is almost 1 mm longer than the scales that would be obtained if a spherical geometry would have been assumed. Our results highlight the importance of a critical assessment of the geometrical model assumptions commonly applied in the 3D analysis of crystal size distributions, and underline the need for a quantitative understanding of interface processes in order to appreciate their role in the kinetics of contact metamorphic reactions and rock texture formation. References: Petley-Ragan A, Gaidies F, Pattison DRM (2016) A statistical analysis of the distribution of cordierite and biotite in hornfels from the Bugaboo contact aureole: implications for the kinetics of porphyroblast crystallization. Journal of Metamorphic Geology 34:85-101

  11. Flow pattern, pressure drop and void fraction of two-phase gas-liquid flow in an inclined narrow annular channel

    SciTech Connect

    Wongwises, Somchai; Pipathattakul, Manop

    2006-03-01

    Two-phase flow pattern, pressure drop and void fraction in horizontal and inclined upward air-water two-phase flow in a mini-gap annular channel are experimentally studied. A concentric annular test section at the length of 880mm with an outer diameter of 12.5mm and inner diameter of 8mm is used in the experiments. The flow phenomena, which are plug flow, slug flow, annular flow, annular/slug flow, bubbly/plug flow, bubbly/slug-plug flow, churn flow, dispersed bubbly flow and slug/bubbly flow, are observed and recorded by high-speed camera. A slug flow pattern is found only in the horizontal channel while slug/bubbly flow patterns are observed only in inclined channels. When the inclination angle is increased, the onset of transition from the plug flow region to the slug flow region (for the horizontal channel) and from the plug flow region to slug/bubbly flow region (for inclined channels) shift to a lower value of superficial air velocity. Small shifts are found for the transition line between the dispersed bubbly flow and the bubbly/plug flow, the bubbly/plug flow and the bubbly/slug-plug flow, and the bubbly/plug flow and the plug flow. The rest of the transition lines shift to a higher value of superficial air velocity. Considering the effect of flow pattern on the pressure drop in the horizontal tube at low liquid velocity, the occurrence of slug flow stops the rise of pressure drop for a short while, before rising again after the air velocity has increased. However, the pressure does not rise abruptly in the tubes with {theta}=30{sup o} and 60{sup o} when the slug/bubbly flow occurs. At low gas and liquid velocity, the pressure drop increases, when the inclination angles changes from horizontal to 30{sup o} and 60{sup o}. Void fraction increases with increasing gas velocity and decreases with increasing liquid velocity. After increasing the inclination angle from horizontal to {theta}=30{sup o} and 60{sup o}, the void fraction appears to be similar, with a decreasing trend when the inclination angle increases. (author)

  12. A prospective pilot study to evaluate wound outcomes and levels of serum C-reactive protein and interleukin-6 in the wound fluid of patients with trauma-related chronic wounds.

    PubMed

    Liu, Tao; Yang, Fan; Li, Zhanfei; Yi, Chengla; Bai, Xiangjun

    2014-06-01

    If surgical closure of chronic wounds is an option, choosing an appropriate time to definitely close these wounds remains a challenge. Although the underlying mechanisms of nonhealing are not completely understood, serum C-reactive protein (CRP) and interleukin-6 (IL-6) in wound fluid have been found to be markers of the systemic and local inflammation state of chronic wounds. The purpose of this prospective, descriptive pilot study was to evaluate the effect of debridement, systemic antibiotics, and negative pressure wound therapy (NPWT) on the outcomes of trauma-related chronic wounds and changes in local inflammation responses, measured using CRP and IL-6 levels as indicators of cytokine regulation. Between June 2012 and May 2013, 20 consecutive patients (14 men, six women, mean age 40 [range 17-56] years) with various trauma-related, nonhealing chronic wounds were enrolled in the study after failing to heal for an average of 8.5 (range 6-16) weeks using a protocol of regular debridement and gauze dressings. Before the start of the study, wounds were cultured, and laboratory values for white blood cell count (WBC), neutrophils, and levels of serum CRP and IL-6 in the wound fluid obtained. Wounds were surgically debrided and NPWT (continuous at 125 mm Hg) applied. All patients were prescribed systemic antibiotics, and mean time interval between NPWT dressing changes was 5 (range 3-7) days. During an average mean NPWT treatment time of 13 (range 5-20) days, CRP and IL-6 concentrations decreased from 66.4 mg/L to 10.4 mg/L and 44.1 pg/mL to 8.6 pg/mL, respectively (P <0.001). The presence/absence of bacteria, WBC, and neutrophil counts did not change. No complications were noted, and all wounds were successfully closed using various surgical procedures. In this study, clinical wound improvement and a significant decrease in wound fluid CRP and IL-6 levels were observed. Studies with a larger sample size and a more robust study design may help elucidate the

  13. Assessing Agreement between Radiomic Features Computed for Multiple CT Imaging Settings

    PubMed Central

    Lu, Lin; Ehmke, Ross C.; Schwartz, Lawrence H.; Zhao, Binsheng

    2016-01-01

    Objectives Radiomics utilizes quantitative image features (QIFs) to characterize tumor phenotype. In practice, radiological images are obtained from different vendors’ equipment using various imaging acquisition settings. Our objective was to assess the inter-setting agreement of QIFs computed from CT images by varying two parameters, slice thickness and reconstruction algorithm. Materials and Methods CT images from an IRB-approved/HIPAA-compliant study assessing thirty-two lung cancer patients were included for the analysis. Each scan’s raw data were reconstructed into six imaging series using combinations of two reconstruction algorithms (Lung[L] and Standard[S]) and three slice thicknesses (1.25mm, 2.5mm and 5mm), i.e., 1.25L, 1.25S, 2.5L, 2.5S, 5L and 5S. For each imaging-setting, 89 well-defined QIFs were computed for each of the 32 tumors (one tumor per patient). The six settings led to 15 inter-setting comparisons (combinatorial pairs). To reduce QIF redundancy, hierarchical clustering was done. Concordance correlation coefficients (CCCs) were used to assess inter-setting agreement of the non-redundant feature groups. The CCC of each group was assessed by averaging CCCs of QIFs in the group. Results Twenty-three non-redundant feature groups were created. Across all feature groups, the best inter-setting agreements (CCCs>0.8) were 1.25S vs 2.5S, 1.25L vs 2.5L, and 2.5S vs 5S; the worst (CCCs<0.51) belonged to 1.25L vs 5S and 2.5L vs 5S. Eight of the feature groups related to size, shape, and coarse texture had an average CCC>0.8 across all imaging settings. Conclusions Varying degrees of inter-setting disagreements of QIFs exist when features are computed from CT images reconstructed using different algorithms and slice thicknesses. Our findings highlight the importance of harmonizing imaging acquisition for obtaining consistent QIFs to study tumor imaging phonotype. PMID:28033372

  14. Evaluation of bond strength of silorane and methacrylate based restorative systems to dentin using different cavity models

    PubMed Central

    ISAAC, Stephano Zerlottini; BERGAMIN, Ana Claudia Pietrobom; TURSSI, Cecília Pedroso; do AMARAL, Flávia Lucisano Botelho; BASTING, Roberta Tarkany; FRANÇA, Fabiana Mantovani Gomes

    2013-01-01

    Objective The aim of this in vitro study was to evaluate the microtensile bond strength (µTBS) to dentin of two different restorative systems: silorane-based (P90), and methacrylate-based (P60), using two cavity models. Material and Methods Occlusal enamel of 40 human third molars was removed to expose flat dentin surface. Class I cavities with 4 mm mesial-distal width, 3 mm buccal-lingual width and 3 mm depth (C-factor=4.5) were prepared in 20 teeth, which were divided into two groups (n=10) restored with P60 and P90, bulk-filled after dentin treatment according to manufacturer's instructions. Flat buccal dentin surfaces were prepared in the 20 remaining teeth (C-factor=0.2) and restored with resin blocks measuring 4x3x3 mm using the two restorative systems (n=10). The teeth were sectioned into samples with area between 0.85 and 1.25 mm2 that were submitted to µTBS testing, using a universal testing machine (EMIC) at speed of 0.5 mm/min. Fractured specimens were analyzed under stereomicroscope and categorized according to fracture pattern. Data were analyzed using ANOVA and Tukey Kramer tests. Results For flat surfaces, P60 obtained higher bond strength values compared with P90. However, for Class I cavities, P60 showed significant reduction in bond strength (p<0.05). No statistical difference between restorative systems was shown for Class I cavity model (p>0.05), or between Class I Cavity and Flat Surface group, considering P90 restorative system (p>0.05). Regarding fracture pattern, there was no statistical difference among groups (p=0.0713) and 56.3% of the fractures were adhesive. Conclusion It was concluded that methacrylate-based composite µTBS was influenced by cavity models, and the use of silorane-based composite led to similar bond strength values compared to the methacrylate-based composite in cavities with high C-factor. PMID:24212992

  15. Convergence of visceral and somatic inputs onto subnucleus reticularis dorsalis neurones in the rat medulla.

    PubMed Central

    Roy, J C; Bing, Z; Villanueva, L; Le Bars, D

    1992-01-01

    1. In anaesthetized rats, recordings were made within the medullary subnucleus reticularis dorsalis (SRD) from neurones that exhibited convergence of nociceptive inputs from the entire surface of the body. Neurones with total nociceptive convergence responded to supramaximal percutaneous electrical stimuli (2 ms duration) with early and late peaks due to the activation of A delta and C fibres, respectively, no matter which part of the body was stimulated. Neurones with partial nociceptive convergence responded to identical stimuli with an A delta peak of activation regardless of which part of the body was stimulated and with a C peak of activation from some, mainly contralateral, parts of the body. The characteristics of the responses of these neurones to graded colo-rectal distension (< or = 100 mmHg) were analysed. 2. The majority of neurones with total nociceptive convergence (n = 13 out of 16) responded to colo-rectal distension by increasing their firing rates. Although these neurones were virtually unresponsive to the lowest pressure employed (12.5 mmHg), they increased their discharges monotonically for distensions in the 26-100 mmHg range and these responses were sometimes followed by after-discharges. One of these neurones, which exhibited a high level of spontaneous activity, was inhibited during colo-rectal distension. None of the neurones with partial nociceptive convergence recorded (n = 10) ever changed its firing rate during increases of intracolonic pressure up to 100 mmHg. 3. It is concluded that neurones with total nociceptive convergence give monotonic stimulus-response relationships for colo-rectal distensions. Thus, neurones with total nociceptive convergence can encode the strength of visceral stimuli, probably within the noxious range, just as they have previously been shown to do for thermal and mechanical cutaneous stimuli. Together with previous electrophysiological and neuroanatomical findings, this study provides further evidence for the convergence of noxious inputs onto single SRD neurones. 4. It is suggested that neurones with total nociceptive convergence could be a link in spino-bulbospinal loops involved in autonomic reactions to strong visceral stimulation. In addition, SRD neurones could be an important supraspinal relay in the mechanisms of visceral pain. PMID:1302266

  16. Experimental demonstration of passive acoustic imaging in the human skull cavity using CT-based aberration corrections

    SciTech Connect

    Jones, Ryan M.; O’Reilly, Meaghan A.; Hynynen, Kullervo

    2015-07-15

    Purpose: Experimentally verify a previously described technique for performing passive acoustic imaging through an intact human skull using noninvasive, computed tomography (CT)-based aberration corrections Jones et al. [Phys. Med. Biol. 58, 4981–5005 (2013)]. Methods: A sparse hemispherical receiver array (30 cm diameter) consisting of 128 piezoceramic discs (2.5 mm diameter, 612 kHz center frequency) was used to passively listen through ex vivo human skullcaps (n = 4) to acoustic emissions from a narrow-band fixed source (1 mm diameter, 516 kHz center frequency) and from ultrasound-stimulated (5 cycle bursts, 1 Hz pulse repetition frequency, estimated in situ peak negative pressure 0.11–0.33 MPa, 306 kHz driving frequency) Definity™ microbubbles flowing through a thin-walled tube phantom. Initial in vivo feasibility testing of the method was performed. The performance of the method was assessed through comparisons to images generated without skull corrections, with invasive source-based corrections, and with water-path control images. Results: For source locations at least 25 mm from the inner skull surface, the modified reconstruction algorithm successfully restored a single focus within the skull cavity at a location within 1.25 mm from the true position of the narrow-band source. The results obtained from imaging single bubbles are in good agreement with numerical simulations of point source emitters and the authors’ previous experimental measurements using source-based skull corrections O’Reilly et al. [IEEE Trans. Biomed. Eng. 61, 1285–1294 (2014)]. In a rat model, microbubble activity was mapped through an intact human skull at pressure levels below and above the threshold for focused ultrasound-induced blood–brain barrier opening. During bursts that led to coherent bubble activity, the location of maximum intensity in images generated with CT-based skull corrections was found to deviate by less than 1 mm, on average, from the position obtained using source-based corrections. Conclusions: Taken together, these results demonstrate the feasibility of using the method to guide bubble-mediated ultrasound therapies in the brain. The technique may also have application in ultrasound-based cerebral angiography.

  17. Clinical Evaluation of a Robotic 6-Degree of Freedom Treatment Couch for Frameless Radiosurgery

    SciTech Connect

    Gevaert, Thierry; Verellen, Dirk; Engels, Benedikt; Depuydt, Tom; Heuninckx, Karina; Tournel, Koen; Duchateau, Michael; Reynders, Truus; De Ridder, Mark

    2012-05-01

    Purpose: To evaluate the added value of 6-degree of freedom (DOF) patient positioning with a robotic couch compared with 4DOF positioning for intracranial lesions and to estimate the immobilization characteristics of the BrainLAB frameless mask (BrainLAB AG, Feldkirchen, Germany), more specifically, the setup errors and intrafraction motion. Methods and Materials: We enrolled 40 patients with 66 brain metastases treated with frameless stereotactic radiosurgery and a 6DOF robotic couch. Patient positioning was performed with the BrainLAB ExacTrac stereoscopic X-ray system. Positioning results were collected before and after treatment to assess patient setup error and intrafraction motion. Existing treatment planning data were loaded and simulated for 4DOF positioning and compared with the 6DOF positioning. The clinical relevance was analyzed by means of the Paddick conformity index and the ratio of prescribed isodose volume covered with 4DOF to that obtained with the 6DOF positioning. Results: The mean three-dimensional setup error before 6DOF correction was 1.91 mm (SD, 1.25 mm). The rotational errors were larger in the longitudinal (mean, 0.23 Degree-Sign ; SD, 0.82 Degree-Sign ) direction compared with the lateral (mean, -0.09 Degree-Sign ; SD, 0.72 Degree-Sign ) and vertical (mean, -0.10 Degree-Sign ; SD, 1.03 Degree-Sign ) directions (p < 0.05). The mean three-dimensional intrafraction shift was 0.58 mm (SD, 0.42 mm). The mean intrafractional rotational errors were comparable for the vertical, longitudinal, and lateral directions: 0.01 Degree-Sign (SD, 0.35 Degree-Sign ), 0.03 Degree-Sign (SD, 0.31 Degree-Sign ), and -0.03 Degree-Sign (SD, 0.33 Degree-Sign ), respectively. The mean conformity index decreased from 0.68 (SD, 0.08) (6DOF) to 0.59 (SD, 0.12) (4DOF) (p < 0.05). A loss of prescribed isodose coverage of 5% (SD, 0.08) was found with the 4DOF positioning (p < 0.05). Half a degree for longitudinal and lateral rotations can be identified as a threshold for coverage loss. Conclusions: With a mask immobilization, patient setup error and intrafraction motions need to be evaluated and corrected for. The 6DOF patient positioning with a 6DOF robotic couch to correct translational and rotational setup errors improves target positioning with respect to treatment isocenter, which is in direct relation with the clinical outcome, compared with the 4DOF positioning.

  18. High-Speed Transport of Fluid Drops and Solid Particles via Surface Acoustic Waves

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph; Bao, Xiaoqi; Sherrit, Stewart; Badescu, Mircea; Lih, Shyh-shiuh

    2012-01-01

    A compact sampling tool mechanism that can operate at various temperatures, and transport and sieve particle sizes of powdered cuttings and soil grains with no moving parts, has been created using traveling surface acoustic waves (SAWs) that are emitted by an inter-digital transducer (IDT). The generated waves are driven at about 10 MHz, and it causes powder to move towards the IDT at high speed with different speeds for different sizes of particles, which enables these particles to be sieved. This design is based on the use of SAWs and their propelling effect on powder particles and fluids along the path of the waves. Generally, SAWs are elastic waves propagating in a shallow layer of about one wavelength beneath the surface of a solid substrate. To generate SAWs, a piezoelectric plate is used that is made of LiNbO3 crystal cut along the x-axis with rotation of 127.8 along the y-axis. On this plate are printed pairs of fingerlike electrodes in the form of a grating that are activated by subjecting the gap between the electrodes to electric field. This configuration of a surface wave transmitter is called IDT. The IDT that was used consists of 20 pairs of fingers with 0.4-mm spacing, a total length of 12.5 mm. The surface wave is produced by the nature of piezoelectric material to contract or expand when subjected to an electric field. Driving the IDT to generate wave at high amplitudes provides an actuation mechanism where the surface particles move elliptically, pulling powder particles on the surface toward the wavesource and pushing liquids in the opposite direction. This behavior allows the innovation to separate large particles and fluids that are mixed. Fluids are removed at speed (7.5 to 15 cm/s), enabling this innovation of acting as a bladeless wiper for raindrops. For the windshield design, the electrodes could be made transparent so that they do not disturb the driver or pilot. Multiple IDTs can be synchronized to transport water or powder over larger distances. To demonstrate the transporting action, a video camera was used to record the movement. The speed of particles was measured from the video images.

  19. Amplitude modulated chirp excitation to reduce grating lobes and maintain ultrasound intensity at the focus of an array.

    PubMed

    Karunakaran, Chandra P; Oelze, Michael L

    2013-09-01

    During application of high intensity focused ultrasound (HIFU) with therapy arrays, the existence of grating lobes can cause heating at unintended tissue regions. Therefore, the reduction of grating lobes in therapeutic arrays is an important goal. One way to reduce the grating lobes in therapy arrays is to excite the arrays with broadband signals (defined here as >10% fractional bandwidth). To achieve a reduction in grating lobe levels in an ultrasonic array, coded waveforms can be utilized that reduce the grating lobe levels while maintaining the spatial peak temporal average intensity. In this study, a 5-MHz, 9-element, 1.25 mm inter-elemental spacing linear array was excited by a sinusoidal waveform, a conventional linear chirp, and a modified linear chirp. Both chirps spanned the -3-dB bandwidth of the transducer. The conventional chirp was a broadband signal with a linear sweep of frequencies between 2.5 and 7.5 MHz, with all frequency components excited with equal amplitude. The modified chirp signal also swept the frequencies between 2.5 and 7.5 MHz, but the amplitude was weighted such that the edges (low and high frequencies of the band) were excited with more energy than the center of the band. In simulations, the field patterns for the sinusoidal, conventional chirp and modified chirp excitations were produced from the array using Field II and compared. For experiments, the beam pattern from a 5-MHz single-element transducer was mapped using a hydrophone for the sinusoidal, conventional chirp and modified chirp excitation. Each field from the transducer was repeated and summed to produce a field from an array of 9 elements. The difference in the time averaged intensity (in dB) in the main lobe and grating lobes were estimated for each excitation and compared. The results demonstrated that the chirp signals resulted in decreases in grating lobe levels compared to the main lobe, i.e. 10 dB down for focusing and 6 dB down for focusing and steering. A further 1 dB decrease in grating lobe levels was observed for the modified chirp excitation compared to the conventional chirp excitation, which corresponds to ~21% reduction in energy deposition at the grating lobe location.

  20. Frequency-shifted interferometry for fiber-optic sensing

    NASA Astrophysics Data System (ADS)

    Ye, Fei

    This thesis studies frequency-shifted interferometry (FSI), a useful and versatile technique for fiber-optic sensing. I first present FSI theory by describing practical FSI configurations and discussing the parameters that affect system performance. Then, I demonstrate the capabilities of FSI in fiber-optic sensor multiplexing and high sensitivity chemical analysis. We implemented a cryogenic liquid level sensing system in which an array of 3 fiber Bragg grating (FBG) based sensors was interrogated by FSI. Despite sensors' spectral overlap, FSI is able to separate sensor signals according to their spatial locations and to measure their spectra, from which whether a sensor is in liquid or air can be unambiguously determined. I showed that a broadband source paired with a fast tunable filter can be used in FSI systems as the light source. An array of 9 spectrally overlapping FBGs was successfully measured by such a system, indicating the potential of system cost reduction as well as measurement speed improvement. I invented the the FSI-CRD technique, a highly sensitive FSI-based fiber cavity ring-down (CRD) method capable of deducing minuscule loss change in a fiber cavity from the intensity decay rate of continuous-wave light circulating in the cavity. As a proof-of-principle experiment, I successfully measured the fiber bend loss introduced in the fiber cavity with FSI-CRD, which was found to be 0.172 dB/m at a bend radius of 12.5 mm. We then applied FSI-CRD to evanescent-field sensing. We incorporated fiber tapers as the sensor head in the system and measured the concentration of 1-octyne solutions. A minimum detectable 1-octyne concentration of 0.29% was achieved with measurement sensitivity of 0.0094 dB/% 1-octyne. The same system also accurately detected the concentration change of sodium chloride (NaCl) and glucose solutions. Refractive index sensitivity of 1 dB/RIU with a measurement error of 1x10-4 dB was attined for NaCl solutions. Finally, I proposed a theoretical model to study the polarization effects in FSI systems. Preliminary results show that the model can already explain the experimental observations. It not only provides insight into how to improve system performance but also suggests potential new applications of the technique.

  1. Intensive versus Guideline Blood Pressure and Lipid Lowering in Patients with Previous Stroke: Main Results from the Pilot ‘Prevention of Decline in Cognition after Stroke Trial’ (PODCAST) Randomised Controlled Trial

    PubMed Central

    Scutt, Polly; Blackburn, Daniel J.; Ankolekar, Sandeep; Krishnan, Kailash; Ballard, Clive; Burns, Alistair; Mant, Jonathan; Passmore, Peter; Pocock, Stuart; Reckless, John; Sprigg, Nikola; Stewart, Rob; Wardlaw, Joanna M.; Ford, Gary A.

    2017-01-01

    Background Stroke is associated with the development of cognitive impairment and dementia. We assessed the effect of intensive blood pressure (BP) and/or lipid lowering on cognitive outcomes in patients with recent stroke in a pilot trial. Methods In a multicentre, partial-factorial trial, patients with recent stroke, absence of dementia, and systolic BP (SBP) 125–170 mmHg were assigned randomly to at least 6 months of intensive (target SBP <125 mmHg) or guideline (target SBP <140 mmHg) BP lowering. The subset of patients with ischaemic stroke and total cholesterol 3.0–8.0 mmol/l were also assigned randomly to intensive (target LDL-cholesterol <1.3 mmol/l) or guideline (target LDL-c <3.0 mmol/l) lipid lowering. The primary outcome was the Addenbrooke’s Cognitive Examination-Revised (ACE-R). Results We enrolled 83 patients, mean age 74.0 (6.8) years, and median 4.5 months after stroke. The median follow-up was 24 months (range 1–48). Mean BP was significantly reduced with intensive compared to guideline treatment (difference –10·6/–5·5 mmHg; p<0·01), as was total/LDL-cholesterol with intensive lipid lowering compared to guideline (difference –0·54/–0·44 mmol/l; p<0·01). The ACE-R score during treatment did not differ for either treatment comparison; mean difference for BP lowering -3.6 (95% CI -9.7 to 2.4), and lipid lowering 4.4 (95% CI -2.1 to 10.9). However, intensive lipid lowering therapy was significantly associated with improved scores for ACE-R at 6 months, trail making A, modified Rankin Scale and Euro-Qol Visual Analogue Scale. There was no difference in rates of dementia or serious adverse events for either comparison. Conclusion In patients with recent stroke and normal cognition, intensive BP and lipid lowering were feasible and safe, but did not alter cognition over two years. The association between intensive lipid lowering and improved scores for some secondary outcomes suggests further trials are warranted. Trial Registration

  2. [Optical Design of Miniature Infrared Gratings Spectrometer Based on Planar Waveguide].

    PubMed

    Li, Yang-yu; Fang, Yong-hua; Li, Da-cheng; Liu, Yang

    2015-03-01

    infrared planar waveguide spectrometer is designed using this method. The operation wavelength range is 8 - 12 μm, the numerical aperture is 0.22, and the linear array detector contains 64 elements. By using Zemax software, the design is optimized and analyzed. The results indicate that the size of the optical system is 130 mm x 125 mm x 20 mm and the spectral resolution of spectrometer is 80 nm, which satisfy the requirements of design index. Thus it is this method that can be used for designing a miniature spectrometer without movable parts and sizes in the range of several cubic centimeters.

  3. Introduction of a new laser-scalpel for partial kidney resection based on 1.94 micrometer fiber laser system: initial in vivo-data

    NASA Astrophysics Data System (ADS)

    Tedsen, Sönke; Theisen-Kunde, Dirk; Doehn, Christian; Kausch, Ingo; Jocham, Dieter

    2009-02-01

    The technique of nephron sparing surgery has matured significantly over the past decade and is emerging as an oncologically sound procedure for the management of renal tumors. Methods of tumor excision as well as parenchymal reconstruction in a hemostaticallly controlled field have evolved to make this procedure safer. In an attempt to find an improoved hemostatic cutting instrument we developed a 1.94 micrometer Laser-Scalpel system in a porcine model. We evaluated data for partial porcine kidney resection performed by a 1.94 micrometer Laser-Scalpel and compared the data to those of a standard HF- (High- Frequency) dissection device. In 12 pigs general anesthesia and a median laparotomy was performed to expose both kidneys. In each pig one kidney was partially resected with the Laser-Scalpel and the other side with the HF-dissection device. The first 6 pigs were euthanized immediately after the procedure. The following 6 pigs were allowed to recover and underwent 2-3 weeks later euthanasia. The final evaluation data included total resection time, blood loss, mass of dissected tissue, total ischemic time and histological examination. Mean resected kidney tissue mass was 4.75 g with the laser system and 5.57 g for the HF-dissector, respectively. Mean estimated blood loss was 22 ml for the Laser- Scalpel and 78.2 ml for the HF-dissection device. Resection time was 9.45 min for the Laser-scalpel compared to 10.16 min. No complications, specifically no postoperative bleeding, occured in any of the animals. Histological evaluation with H&E staining showed a carbonized zone of about 0.57 mm directly at the dissected edge followed by a thermal damaged zone of about 1.25 mm in width. Thereafter healthy tissue was found in all histological samples. Partial kidney resection was easily and fast performed by the use of a 1.94 micrometer Laser-Scalpel system. Hemostasis was highly sufficient, so blood loss was minimal compared to conventional HF-dissection device. Therefore the 1.94 micrometer Laser-Scalpel system is a very promising dissection device for urological surgery.

  4. Dynamics of deposited fly-ash and fine grained magnetite in sandy material of different porosity (column experiments)

    NASA Astrophysics Data System (ADS)

    Kapicka, Ales; Kodesova, Radka; Petrovsky, Eduard; Grison, Hana

    2010-05-01

    Several studies confirm that soil magnetometry can serve as proxy of industrial immisions as well as heavy-metal contamination. The important assumption for magnetic mapping of contaminated soils is that atmospherically deposited particulate matter, including the ferrimagnetic phase, accumulates in the top soil horizons and remains there over long period. Only if this is true, large areas can be reliably mapped using soil magnetometry, and, moreover, this method can be used also for long-term monitoring. However, in soil types such as sandy soils with different porosity or soils with substantial variability of water regime, translocation of the deposited anthropogenic particles may result in biased (underestimated) values of the measured topsoil magnetic susceptibility. From the physical point of view, this process may be considered as colloid transport through porous medium. In our column experiments in laboratory we used three technical sands with different particle sizes (0,63 - 1.25mm, 0,315-0,80mm, 0,10-0,63mm). Sands in cylinders were contaminated on the surface by fly-ashes from coal-burning power plant (mean grain size 10μm) and fine grained Fe3O4 (grain size < 20 μm). Soil moisture sensors were used to monitor water regime within the sand columns after controlled rain simulation and temperature distribution in sand column was measured as well. Vertical migration of ferrimagnetic particles-tracers presented in the fly-ash was measured by SM 400 Kappameter. By means of magnetic susceptibility distribution we studied two parameters: gradual shift of peak concentration of contaminants (relative to surface layer) and maximum penetration depth. Results indicated that after rain simulation (pulls infiltration of defined water volume) the positions of peak values moved downwards compared to the initial state and gradual decrease of susceptibility peak values were detected in all studied sand formations. Fly-ash migrated more or less freely in coarse sand material. In medium and fine sand the contaminants moved only to the depths of several cm due to the pore-space blocking and water flow decrease. Fine-grained magnetite shows different behavior. Position of peaks value is more or less stable and maximum depth of penetration is only a few cm in all cases. Higher grain size value is probably reason for higher stability of magnetite. Moreover, magnetic interaction between grains increase "effective" grain size value and restricts transport in material with given porosity. This research is supported by the Grant Agency ASCR under grant IAA300120701

  5. Surgical Treatment of Double Outlet Right Ventricle Complicated by Pulmonary Hypertension

    PubMed Central

    Wu, Qing-Yu; Li, Dong-Hai; Li, Hong-Yin; Zhang, Ming-Kui; Xu, Zhong-Hua; Xue, Hui

    2017-01-01

    Background: Double outlet right ventricle (DORV) is a group of complex congenital heart abnormalities. Preoperative pulmonary hypertension (PH) is considered an important risk factor for early death during the surgical treatment of DORV. The aim of this study was to report our experience on surgical treatment of DORV complicated by PH. Methods: From June 2004 to November 2016, 61 patients (36 males and 25 females) aged 2 weeks to 26 years (median: 0.67 years and interquartile range: 0.42–1.67 years) with DORV (two great arteries overriding at least 50%) complicated by PH underwent surgical treatment in our center. All patients were categorized according to surgical age and lesion type, respectively. Pulmonary artery systolic pressure (PASP), pulmonary artery diastolic pressure (PADP), and mean pulmonary artery pressure (mPAP) were measured directly before cardiopulmonary bypass (CPB) was established and after CPB was removed. An intracardiac channel procedure was performed in 37 patients, arterial switch procedure in 19 patients, Rastelli procedure in three patient, Senning procedure in one patients, and Mustard procedure in one patient. The Student's t-test and Chi-squared test were performed to evaluate clinical outcomes of the surgical timing and operation choice. Results: Fifty-five patients had uneventful recovery. PASP fell from 55.3 ± 11.2 mmHg to 34.7 ± 11.6 mmHg (t = 14.05, P < 0.001), PADP fell from 29.7 ± 12.5 mmHg to 18.6 ± 7.9 mmHg (t = 7.39, P < 0.001), and mPAP fell from 40.3 ± 10.6 mmHg to 25.7 ± 8.3 mmHg (t = 11.85, P < 0.001). Six (9.8%) patients died owing to complications including low cardiac output syndrome in two patients, respiratory failure in two, pulmonary hemorrhage in one, and sudden death in one patient. Pulmonary artery pressure (PAP) dropped significantly in infant and child patients. Mortality of both infants (13.9%) and adults (33.3%) was high. Conclusions: PAP of patients with DORV complicated by PH can be expected to fall significantly after surgery. An arterial switch procedure can achieve excellent results in patients with transposition of the great arteries type. Higher incidence of complications may occur in patients with ventricular septal defect (VSD) type before 1 year of age. For those with remote VSD type, VSD enlargement and right ventricle outflow tract reconstruction are usually required with acceptable results. The degree of aortic overriding does not influence surgical outcome. PMID:28218213

  6. Petrographic and anatomical characteristics of plant material from two peat deposits of Holocene and Miocene age, Kalimantan, Indonesia

    USGS Publications Warehouse

    Moore, T.A.; Hilbert, R.E.

    1992-01-01

    Samples from two peat-forming environments of Holocene and Miocene age in Kalimantan (Borneo), Indonesia, were studied petrographically using nearly identical sample preparation and microscopic methodologies. Both deposits consist of two basic types of organic material: plant organs/tissues and fine-grained matrix. There are seven predominant types of plant organs and tissues: roots possessing only primary growth, stems possessing only primary growth, leaves, stems/roots with secondary growth, secondary xylem fragments, fragments of cork cells, and macerated tissue of undetermined origin. The fine-grained matrix consists of fragments of cell walls and cell fillings, fungal remains, spores and pollen grains, and resin. Some of the matrix material does not have distinct grain boundaries (at ??500) and this material is designated amorphous matrix. The major difference between the Holocene peat and Miocene lignite in reflected light, oil immersion is a loss of red coloration in the cell walls of tissue in the lignite, presumably due to loss of cellulosic compounds. In addition, cortex and phloem tissue (hence primary roots and stems) are difficult to recognize in the lignite, probably because these large, thin-walled tissues are more susceptible to microbial degradation and compaction. Particle size in both peat and lignite samples display a bimodal distribution when measurements are transformed to a - log2 or phi (??), scale. Most plant parts have modes of 2-3?? (0.25 - 0.125 mm), whereas the finer-grained particulate matrix has modes of 7-9?? (0.008-0.002 mm). This similarity suggest certain degradative processes. The 2-3?? range may be a "stable" size for plant parts (regardless of origin) because this is a characteristics of a substrate which is most suitable for plant growth in peat. The finer-grained matrix material (7-9??) probably results from fungal decay which causes plant material to weaken and with slight physical pressure to shatter into its component

  7. Impact of Node Negative Target Volume Delineation on Contralateral Parotid Gland Dose Sparing Using IMRT in Head and Neck Cancer.

    PubMed

    Magnuson, William J; Urban, Erich; Bayliss, R Adam; Harari, Paul M

    2015-06-01

    There is considerable practice variation in treatment of the node negative (N0) contralateral neck in patients with head and neck cancer. In this study, we examined the impact of N0 neck target delineation volume on radiation dose to the contralateral parotid gland. Following institutional review board approval, 12 patients with head and neck cancer were studied. All had indications for treatment of the N0 neck, such as midline base of tongue or soft palate extension or advanced ipsilateral nodal disease. The N0 neck volumes were created using the Radiation Therapy Oncology Group head and neck contouring atlas. The physician-drawn N0 neck clinical target volume (CTV) was expanded by 25% to 200% to generate volume variation, followed by a 3-mm planning target volume (PTV) expansion. Surrounding organs at risk were contoured and complete intensity-modulated radiation therapy plans were generated for each N0 volume expansion. The median N0 target volume drawn by the radiation oncologist measured 93 cm(3) (range 71-145). Volumetric expansion of the N0 CTV by 25% to 200% increased the resultant mean dose to the contralateral parotid gland by 1.4 to 8.5 Gray (Gy). For example, a 4.1-mm increase in the N0 neck CTV translated to a 2.0-Gy dose increase to the parotid, 7.4 mm to a 4.5 Gy dose increase, and 12.5 mm to an 8.5 Gy dose increase, respectively. The treatment volume designated for the N0 neck has profound impact on resultant dose to the contralateral parotid gland. Variations of up to 15 mm are routine across physicians in target contouring, reflecting individual preference and training expertise. Depending on the availability of immobilization and image guidance techniques, experts commonly recommend 3 to 10 mm margin expansions to generate the PTV. Careful attention to the original volume of the N0 neck CTV, as well as expansion margins, is important in achieving effective contralateral gland sparing to reduce the resultant xerostomia and dysguesia that may ensue after radiotherapy.

  8. Metal content in street dust as a reflection of atmospheric dust emissions from coal power plants, metal smelters, and traffic.

    PubMed

    Žibret, Gorazd; Van Tonder, Danel; Žibret, Lea

    2013-07-01

    Resuspended street dust is a source of inhalable particles in urban environments. Despite contaminated street dust being a possible health risk factor for local population, little is known about the contribution of atmospheric dust emissions and other factors to the content of toxic metals in street dust. The impact of smelting, traffic, and power plants on metal contaminates in street dust is the focus of street dust sampling at 46 locations in the Witbank area (Republic of South Africa). This area is characterized by numerous open-pit coal mines in the Karoo coal basin, which provides a cheap source of energy to numerous metallurgical smelters and ironworks and supplies coal to the coal-fired power plants located nearby. Street dust was collected on asphalt or concrete surfaces with hard plastic brushes, avoiding collecting of possible sand, soil, or plant particles. Chemical analysis was done on the <0.125 mm fraction using inductively coupled plasma mass spectrometry subsequent to total digestion. Exceptionally high concentrations of metals were detected with concentrations of Fe reaching 17.7%, Cr 4.3%, Mn 2%, Ni 366 mg/kg, and V 4,410 mg/kg. Factor analysis indicates three sources for the pollution. Road traffic which contributes to the high concentrations of Cu, Pb, Sb, and Sn, with the highest impacts detected in the town of Witbank. The second source is associated with the metal smelting industry, contributing to Fe, Co, Mn, and V emissions. The highest factor scores were observed around four metallurgical smelter operations, located in the Ferrobank, Highveld, and Clewer industrial areas. Impact of vanadium smelter to street dust composition could still be detected some 20 km away from the sources. Exceptionally high concentrations of Cr were observed in four samples collected next to the Ferrobank industrial area, despite Cr not being loaded in factor 2. The last source of the pollution is most probably fly ash associated with the coal-fired power plants

  9. Solvent removal during synthetic and Nephila fiber spinning.

    PubMed

    Kojic, Nikola; Kojic, Milos; Gudlavalleti, Sauri; McKinley, Gareth

    2004-01-01

    The process by which spiders make their mechanically superior fiber involves removal of solvent (water) from a concentrated protein solution while the solution flows through a progressively narrowing spinning canal. Our aim was to determine a possible mechanism of spider water removal by using a computational model. To develop appropriate computational techniques for modeling of solvent removal during fiber spinning, a study was first performed using a synthetic solution. In particular, the effect of solvent removal during elongational flow (also exhibited in the spinning canal of the spider) on fiber mechanical properties was examined. The study establishes a model for solvent removal during dry spinning of synthetic fibers, assuming that internal diffusion governs solvent removal and that convective resistance is small. A variable internal solvent diffusion coefficient, dependent on solvent concentration, is also taken into account in the model. An experimental setup for dry (air) spinning was used to make fibers whose diameter was on the order of those made by spiders (approximately 1 microm). Two fibers of different thickness, corresponding to different spinning conditions, were numerically modeled for solvent removal and then mechanically tested. These tests showed that the thinner fiber, which lost more solvent under elongational flow, had 5-fold better mechanical properties (elastic modulus of 100 MPa and toughness of 15 MJ/m3) than the thicker fiber. Even though the mechanical properties were far from those of dragline spider silk (modulus of 10 GPa and toughness of 150 MJ/m3), the experimental methodology and numerical principles developed for the synthetic case proved to be valuable when establishing a model for the Nephila spinning process. In this model, an assumption of rapid convective water removal at the spinning canal wall was made, with internal diffusion of water through the fiber as the governing process. Then the diffusion coefficient of water through the initial spinning solution, obtained ex vivo from the Nephila clavipes major ampullate gland, was determined and incorporated into the numerical procedure, along with the wall boundary conditions and canal geometry. Also, a typical fiber reeling speed during web making, as well as the assumption of a dry exiting fiber, were included in the model. The results show that a cross-section of spinning solution (dope), which is initially 70% water, spends 19 s in the spinning canal in order to emerge dry. While the dope cross-section traverses the canal, its velocity increases from 0.37 mm/s at the entrance to 12.5 mm/s at the canal exit. The obtained results thus indicate that simple diffusion, along with the dry wall boundary condition, is a viable mechanism for water removal during typical Nephila fiber spinning.

  10. Volumetric quantification of lung nodules in CT with iterative reconstruction (ASiR and MBIR)

    SciTech Connect

    Chen, Baiyu; Barnhart, Huiman; Richard, Samuel; Robins, Marthony; Colsher, James; Samei, Ehsan

    2013-11-15

    Purpose: Volume quantifications of lung nodules with multidetector computed tomography (CT) images provide useful information for monitoring nodule developments. The accuracy and precision of the volume quantification, however, can be impacted by imaging and reconstruction parameters. This study aimed to investigate the impact of iterative reconstruction algorithms on the accuracy and precision of volume quantification with dose and slice thickness as additional variables.Methods: Repeated CT images were acquired from an anthropomorphic chest phantom with synthetic nodules (9.5 and 4.8 mm) at six dose levels, and reconstructed with three reconstruction algorithms [filtered backprojection (FBP), adaptive statistical iterative reconstruction (ASiR), and model based iterative reconstruction (MBIR)] into three slice thicknesses. The nodule volumes were measured with two clinical software (A: Lung VCAR, B: iNtuition), and analyzed for accuracy and precision.Results: Precision was found to be generally comparable between FBP and iterative reconstruction with no statistically significant difference noted for different dose levels, slice thickness, and segmentation software. Accuracy was found to be more variable. For large nodules, the accuracy was significantly different between ASiR and FBP for all slice thicknesses with both software, and significantly different between MBIR and FBP for 0.625 mm slice thickness with Software A and for all slice thicknesses with Software B. For small nodules, the accuracy was more similar between FBP and iterative reconstruction, with the exception of ASIR vs FBP at 1.25 mm with Software A and MBIR vs FBP at 0.625 mm with Software A.Conclusions: The systematic difference between the accuracy of FBP and iterative reconstructions highlights the importance of extending current segmentation software to accommodate the image characteristics of iterative reconstructions. In addition, a calibration process may help reduce the dependency of accuracy on reconstruction algorithms, such that volumes quantified from scans of different reconstruction algorithms can be compared. The little difference found between the precision of FBP and iterative reconstructions could be a result of both iterative reconstruction's diminished noise reduction at the edge of the nodules as well as the loss of resolution at high noise levels with iterative reconstruction. The findings do not rule out potential advantage of IR that might be evident in a study that uses a larger number of nodules or repeated scans.

  11. HIGH-RESOLUTION L(Y)SO DETECTORS USING PMT-QUADRANT-SHARING FOR HUMAN & ANIMAL PET CAMERAS.

    PubMed

    Ramirez, Rocio A; Liu, Shitao; Liu, Jiguo; Zhang, Yuxuan; Kim, Soonseok; Baghaei, Hossain; Li, Hongdi; Wang, Yu; Wong, Wai-Hoi

    2008-06-01

    We developed high resolution L(Y)SO detectors for human and animal PET applications using Photomultiplier-quadrant-sharing (PQS) technology. The crystal sizes were 1.27 × 1.27 × 10 mm(3) for the animal PQS-blocks and 3.25 × 3.25 × 20 mm(3) for human ones. Polymer mirror film patterns (PMR) were placed between crystals as reflector. The blocks were assembled together using optical grease and wrapped by Teflon tape. The blocks were coupled to regular round PMT's of 19/51 mm in PQS configuration. List-mode data of Ga-68 source (511 KeV) were acquired with our high yield pileup-event recovery (HYPER) electronics and data acquisition software. The high voltage bias was 1100V. Crystal decoding maps and individual crystal energy resolutions were extracted from the data. To investigate the potential imaging resolution of the PET cameras with these blocks, we used GATE (Geant4 Application for Tomographic Emission) simulation package. GATE is a GEANT4 based software toolkit for realistic simulation of PET and SPECT systems. The packing fractions of these blocks were found to be 95.6% and 98.2%. From the decoding maps, all 196 and 225 crystals were clearly identified. The average energy resolutions were 14.0% and 15.6%. For small animal PET systems, the detector ring diameter was 16.5 cm with an axial field of view (AFOV) of 11.8 cm. The simulation data suggests that a reconstructed radial (tangential) spatial resolution of 1.24 (1.25) mm near the center is potentially achievable. For the wholebody human PET systems, the detector ring diameter was 86 cm. The simulation data suggests that a reconstructed radial (tangential) spatial resolution of 3.09(3.38) mm near the center is potentially achievable. From this study we can conclude that PQS design could achieve high spatial resolutions and excellent energy resolutions on human and animal PET systems with substantially lower production costs and inexpensive readout devices.

  12. Optical design of the NASA-NSF extreme precision Doppler spectrograph concept "WISDOM"

    NASA Astrophysics Data System (ADS)

    Barnes, Stuart I.; Fżrész, Gábor; Simcoe, Robert A.; Shectman, Stephen A.; Woods, Deborah F.

    2016-08-01

    The WISDOM instrument concept was developed at MIT as part of a NASA-NSF funded study to equip the 3.5m WIYN telescope with an extremely precise radial velocity spectrometer. The spectrograph employs an asymmetric white pupil optical design, where the instrument is split into two nearly identical "Short" (380 to 750 nm) and "Long"" (750 to 1300 nm) wavelength channels. The echelle grating and beam sizes are R3.75/125mm and R6/80mm in the short and long channels respectively. Together with the pupil slicer, and octagonal to rectangular fibre coupling, this permits resolving powers over R = 120k with a 1.2" diameter fibre on the sky. A factor of two reduction in the focal length between the main collimator OAP and the transfer collimator ensures a very compact instrument, with a small white pupil footprint, thereby enabling small cross-dispersing and camera elements. A dichroic is used near the white pupil to split each of the long and short channels into two, so that the final spectrograph has 4 channels; namely "Blue," "Green," "Red" and "NIR." Each of these channels has an anamorphic VPH grism for cross-dispersion, and a fully dioptric all-spherical camera objective. The spectral footprints cover 4k×4k and 6k×6k CCDs with 15 µm pixels in the short "Blue" and "Green" wavelength channels, respectively. A 4k×4k CCD with 15 μm pixels is used in the long "Red" channel, with a HgCdTe 1.7 μm cutoff 4k×4k detector with 10um pixels is to be used in the long "NIR" channel. The white pupil relay includes a Mangin mirror very close to the intermediate focus to correct the white pupil relay Petzval curvature before it is swept into a cylinder by the cross-dispersers. This design decision allows each of the dioptric cameras to be fully optimised and tested independently of the rest of the spectrograph. The baseline design for the cameras also ensures that the highest possible (diffraction limited) image quality is achieved across all wavelengths, while also ensuring

  13. Role of Matrix Metalloproteinases 2 in Spinal Cord Injury-Induced Neuropathic Pain

    PubMed Central

    Miranpuri, Gurwattan S.; Schomberg, Dominic T.; Alrfaei, Bahauddeen; King, Kevin C.; Rynearson, Bryan; Wesley, Vishwas S.; Khan, Nayab; Obiakor, Kristen; Wesley, Umadevi V.; Resnick, Daniel K.

    2016-01-01

    Neuropathic pain (NP) affects approximately 4 million people in the United States with spinal cord injury (SCI) being a common cause. Matrix metalloproteinases (MMPs) play an integral role in mediating inflammatory responses, cellular signaling, cell migration, extracellular matrix degradation and tissue remodeling and repair. As such, they are major components in the pathogenesis of secondary injury within the central nervous system. Other gene regulatory pathways, specifically MAPK/extracellular signaling-regulated kinase (ERK) and Wnt/β-catenin, are also believed to participate in secondary injury likely intersect. The study aims to examine the MMP-2 signaling pathway associated with ERK and Wnt/β-catenin activity during contusion SCI (cSCI)-induced NP in a rat model. This is an experimental study investigating the implication of MMP-2 in SCI-induced NP and its association with the cellular and molecular changes in the interactions between extracellular signaling kinase and β-catenin. Adult Sprague-Dawley rats received cSCI injury by NYU impactor by dropping 10 g weight from a height of 12.5 mm. Locomotor functional recovery of injured rats was measured on post cSCI day 1, and weekly thereafter for 6 weeks using Basso, Beattie and Bresnahan scores. Thermal hyperalgesia (TH) testing was performed on days 21, 28, 35 and 42 post cSCI. The expression and/or activity of MMP-2, β-catenin and ERK were studied following harvest of spinal cord tissues between 3 and 6 weeks post cSCI. All experiments were funded by the department of Neurological Surgery at the University of Wisconsin, School of Medicine and Public Health having no conflict of interest. MMP-2 and β-catenin expression were elevated and gradually increased from days 21 to 42 compared to sham-operated rats and injured rats that did not exhibit TH. The expression of phosphorylated ERK (phospho-ERK) increased on day 21 but returned to baseline levels on day 42 whereas total ERK levels remained relatively unchanged and constant. Chronic NP is associated with changes in the expression of MMP-2, β-catenin and ERK. Our data suggest that the transient upregulation of phospho-ERK is involved in the initial upregulation of both β-catenin and MMP-2 following cSCI-induced NP states. PMID:27536019

  14. Jaw expansive lesions: population incidence and CT dentalscan role

    PubMed Central

    FIASCHETTI, V.; FANUCCI, E.; RASCIONI, M.; OTTRIA, L.; BARLATTANI, A.; SIMONETTI, G.

    2011-01-01

    SUMMARY Aim The aim of the study is to evaluate the incidence of different expansive lesions and the advantages of the clinical employment of Dentalscan to study bones lesions and to establish a common diagnostic path. Materials and methods Since January 2005 to November 2009, 3200 patients, not selected for sex or age, have undergone a CT “Dentalscan” in the department of Diagnostic Imaging, Tor Vergata University Hospital (PTV), a suspect bone pathology was found in 704 of them through the XR-orthopantomograpy (OPT). CT images were obtained with General Electric CT Light Speed multislice. Images were saved in the Advantage Workstation (GE) supported by the “Dentascan” dedicated software and by the 3D software (3D SSD). The protocol was : Slice thickness 1,25 mm, gap 0, matrix 512 × 512, 140 KV and 70 mA. All the lesions were also studied with the dedicated three-dimensional reconstructor 3D SSD. Biopsy for diagnosis was performed on all the lesions, except one (false positive with digital OPT). The technique sensitivity was assessed for two important classes: benign and malignant lesions. Results Through CT Dentascan a detailed evaluation of the jaws lesions and their extension was obtained. 656 patients (93.1 %) out of 704 examined for a suspicious lesion on the orthopantomography had a benign lesion: (127 follicular cysts (18.2 %), 181 radicular cysts (25.1%), 93 non odontogenic cysts (13.2%), 29 fibroma (4.2%), 198 odontomes (28.2%), 24 ameloblastoma (3.6%), 4 brown tumors (0.7%), 47 (6.9%) had malignant lesions: (12 carcinoma (1.7%), 29 metastasis (4.3%), 6 sarcoma (0.8%), 1 Dentascan CT resulted to be negative (1 false positive of digital OPT). The sensitivity of the technique for both groups was 99% for benign lesions and 98% for malign lesions. Conclusions CT Dentascan characteristics suggest to consider these techniques as the gold standard for the evaluation of jaw expansive lesions and the support of surgical planning. PMID:23285385

  15. Pre-construction progress of giant steerable science mirror for TMT

    NASA Astrophysics Data System (ADS)

    Yang, Fei; Zhao, Hongchao; An, Qichang; Guo, Peng; Jiang, Haibo; Han, Linchu; Ford, Virginia; Cole, Glen; Smith, Byron; Campbell, Marvin

    2016-07-01

    The Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP) team is developing the Giant Steerable Science Mirror (GSSM) for Thirty Meter Telescope (TMT) which will enter the preliminary design phase in 2016. The GSSM is the tertiary mirror of TMT and consists of the world's largest flat telescope mirror (approximately 3.4m X 2.4 m X 100mm thick) having an elliptical perimeter positioned with an extremely smooth tracking and pointing mechanism in a gravity-varying environment. In order to prepare for developing this unique mirror system, CIOMP has been developing a 1/4 scale, functionally accurate version of the GSSM prototype during the pre-construction phase of GSSM. The prototype will incorporate the same optomechanical system and servo control system as the GSSM. The size of the prototype mirror is 898.5mm×634mm×12.5mm with an elliptical perimeter. The mirror will be supported axially by an 18 point whiffletree and laterally with a 12 point whiffletree. The main objective of the preconstruction phase includes requirement validation and risk reduction for GSSM and to increase confidence that the challenge of developing the GSSM can be met. The precision mechanism system and the optical mirror polishing and testing have made good progress. CIOMP has completed polishing the mirror, the prototype mechanism is nearly assembled, some testing has been performed, and additional testing is being planned and prepared. A dummy mirror is being integrated into the cell assembly prototype to verify the design, analysis and interface and will be used when testing the prototype positioner tilt and rotation motions. The prototype positioner tilt and rotator structures have been assembled and tested to measure each subsystem's jitter and dynamic motion. The mirror prototype has been polished and tested to verify the polishing specification requirement and the mirror manufacturing process. The complete assembly, integration and verification of the prototype will be soon finished. Final testing will verify the prototype requirements including mounted mirror surface figure accuracy in 5 different orientations; rotation and tilt motion calibration and pointing precision; motion jitter; and internally generated vibrations. CIOMP has scheduled to complete the prototype by the end of July 2016. CIOMP will get the sufficient test results during the pre-construction phase to prepare to enter the preliminary design for GSSM.

  16. Retention and Treatment Outcomes of an Undernutrition Program for HIV patients involving Ready-to-Use Therapeutic Food at Gondar University Hospital, Ethiopia: A Cross-Sectional Study

    PubMed Central

    Bhagavathula, Akshaya Srikanth; Dawson, Angela; Elnour, Asim Ahmed; Shehab, Abdulla

    2016-01-01

    Introduction Despite global efforts to eradicate poverty and hunger, under-nutrition is still a major health problem, especially in Sub-Saharan Africa, where HIV/AIDS prevalence is also a serious burden. Aim To assess the retention and outcomes of under-nutrition treatment program in Gondar University Hospital, Ethiopia. Settings and Design: A cross-sectional study was conducted in HIV positive children and adults participating in the Ready-to-use Therapeutic Food (RUTF) treatment program at Gondar University Hospital ART clinic for one year from November 2012 to November 2013. Materials and Methods Six hundred and thirty six patient records were followed-up for one year. Outcome variables were Mid-Upper Arm Circumference (MUAC) values measured as severe, moderate acute malnutrition, normal after treatment, non-respondent, relapsed and lost to follow-up using the hospital records of HIV positive children and adults eligible for the program. Statistical Analysis: Univariate and multivariate analysis were performed to compute Crude Odds Ratio (COR) and Adjusted Odds Ratio (AOR). Statistical significance was set at p-value<0.05. Results Among 636 clients, 44.2% achieved MUAC measures ≥ 125 mm for children and ≥ 21 cm for adults at 4 and 6 months. 70.1% of those were children while 29.9% of the 281 were adults. Moreover, a more positive initial response to ready-to-use therapeutic food was found among children as there was significant increase (p<0.05) in MUAC value after the second month of initiating treatment while adults achieved a significant (p<0.05, p<0.01) in MUAC at the 4th and 6th month respectively. There was a significant association between age, nutrition status and treatment outcome, while sex, HIV status, education and residency were not associated with treatment outcome. Conclusion Recovery and weight gain rates were below 50%. Defaulter rates were higher than the Sphere standards and recovery was better in children than adults. Integrated RUTF and

  17. Exploration of chromatic aberration for multiplanar imaging: proof of concept with implications for fast, efficient autofocus.

    PubMed

    Weinigel, Martin; Kellner, Albert L; Price, Jeffrey H

    2009-12-01

    Image-based autofocus determines focus directly from the specimen (as opposed to reflective surface positioning with an offset), but sequential acquisition of a stack of images to measure resolution/sharpness and find best focus is slower than reflective positioning. Simultaneous imaging of multiple focal planes, which is also useful for 3D imaging of live cells, is faster but requires complicated optics. With color CCD cameras and white light sources commonly available, we asked if axial chromatic aberration can be utilized to acquire multiple focal planes simultaneously, and if it can be controlled through a range sufficient for practical use. For proof of concept, we theoretically and experimentally explored the focal differences between three narrow wavelength bands on a 3-chip color CCD camera with and without glass inserts of various thicknesses and dispersions. Ray tracing yielded changes in foci of 0.65-0.9 microm upon insertion of 12.5-mm thick glass samples for green (G, 522 nm) vs. blue (B, 462 nm) and green vs. red (G-R, 604 nm). On a microscope: (1) With no glass inserts, the differences in foci were 2.15 microm (G-B) and 0.43 microm (G-R); (2) With glass inserts, the maximum change in foci for G vs. B was 0.44 microm and for G vs. R was 0.26 microm; and (3) An 11.3 mm thick N-BK7 glass insert shifted the foci 0.9 microm (R), 0.6 microm (G), and 0.35 microm (B), such that the B and R foci were farther apart (2.1 microm vs. 1.7 microm) and the R and G foci were closer together (0.25 microm vs. 0.45 microm). The slopes of the differences in foci were dependent on thickness, index of refraction, and dispersion. The measured differences in foci are comparable to the axial steps of 0.1-0.24 microm commonly used for autofocus, and focal plane separation can be altered by inserting optical elements of various dispersions and thicknesses. By enabling acquisition of multiple, axially offset images simultaneously, chromatic aberration, normally an imaging pariah, creates a possible mechanism for efficient multiplanar imaging of multiple spectral bands from white light illumination.

  18. Orthographic projection capillary array fluorescent sensor for mHealth.

    PubMed

    Balsam, Joshua; Bruck, Hugh Alan; Rasooly, Avraham

    2013-10-01

    To overcome the limited sensitivity of phone cameras for mobile health (mHealth) fluorescent detection, we have previously developed a capillary array which enables a ∼100 × increase in detection sensitivity. However, for an effective detection platform, the optical configuration must allow for uniform measurement sensitivity between channels when using such a capillary array sensor. This is a challenge due to the parallax inherent in imaging long parallel capillary tubes with typical lens configurations. To enable effective detection, we have developed an orthographic projection system in this work which forms parallel light projection images from the capillaries using an object-space telecentric lens configuration. This optical configuration results in a significantly higher degree of uniformity in measurement between channels, as well as a significantly reduced focal distance, which enables a more compact sensor. A plano-convex lens (f=150 mm) was shown to produce a uniform orthographic projection when properly combined with the phone camera's built in lens (f=4mm), enabling measurements of long capillaries (125 mm) to be made from a distance of 160 mm. The number of parallel measurements which can be made is determined by the size of the secondary lens. Based on these results, a more compact configuration with shorter 32 mm capillaries and a plano-convex lens with a shorter focal length (f=10mm) was constructed. This optical system was used to measure serial dilutions of fluorescein with a limit of detection (LOD) of 10nM, similar to the LOD of a commercial plate reader. However, many plate readers based on standard 96 well plate requires sample volumes of 100 μl for measurement, while the capillary array requires a sample volume of less than 10 μl. This optical configuration allows for a device to make use of the ∼100 × increase in fluorescent detection sensitivity produced by capillary amplification while maintaining a compact size and capability to

  19. Hepatic steatosis in overweight/obese females: New screening method for those at risk

    PubMed Central

    Tarantino, Giovanni; Pizza, Genoveffa; Colao, Annamaria; Pasanisi, Fabrizio; Conca, Paolo; Colicchio, Patrizia; Finelli, Carmine; Contaldo, Franco; Di Somma, Carolina; Savastano, Silvia

    2009-01-01

    for systolic blood pressure 0.66, cut-off 125 mm of Hg, sensibility 64%, specificity 75%; AUROC for diastolic blood pressure 0.70, cut-off 85 mm of Hg, sensibility 54.5%, specificity 75%). CONCLUSION: As health care costs are skyrocketing, reliable and mainly inexpensive tools are advisable to better define subjects who really need to lose weight. PMID:19960566

  20. SU-E-T-225: Correction Matrix for PinPoint Ionization Chamber for Dosimetric Measurements in the Newly Released Incise™ Multileaf Collimator Shaped Small Field for CyberKnife M6™ Machine

    SciTech Connect

    Zhang, Y; Li, T; Heron, D; Huq, M

    2015-06-15

    Purpose: For small field dosimetry, such as measurements of output factors for cones or MLC-shaped irregular small fields, ion chambers often Result in an underestimation of the dose, due to both the volume averaging effect and the lack of lateral charged particle equilibrium. This work presents a mathematical model for correction matrix for a PTW PinPoint ionization chamber for dosimetric measurements made in the newly released Incise™ Multileaf collimator fields of the CyberKnife M6™ machine. Methods: A correction matrix for a PTW 0.015cc PinPoint ionization chamber was developed by modeling its 3D dose response in twelve cone-shaped circular fields created using the 5mm, 7.5mm, 10mm, 12.5mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 50mm, 60mm cones in a CyberKnife M6™ machine. For each field size, hundreds of readings were recorded for every 2mm chamber shift in the horizontal plane. The contribution of each dose pixel to a measurement point depended on the radial distance and the angle to the chamber axis. These readings were then compared with the theoretical dose as obtained with Monte Carlo calculation. A penalized least-square optimization algorithm was developed to generate the correction matrix. After the parameter fitting, the mathematical model was validated for MLC-shaped irregular fields. Results: The optimization algorithm used for parameter fitting was stable and the resulted response factors were smooth in spatial domain. After correction with the mathematical model, the chamber reading matched with the calculation for all the tested fields to within 2%. Conclusion: A novel mathematical model has been developed for PinPoint chamber for dosimetric measurements in small MLC-shaped irregular fields. The correction matrix is dependent on detector, treatment unit and the geometry of setup. The model can be applied to non-standard composite fields and provides an access to IMRT point dose validation.

  1. Key biogeochemical factors affecting soil carbon storage in Posidonia meadows

    NASA Astrophysics Data System (ADS)

    Serrano, Oscar; Ricart, Aurora M.; Lavery, Paul S.; Mateo, Miguel Angel; Arias-Ortiz, Ariane; Masque, Pere; Rozaimi, Mohammad; Steven, Andy; Duarte, Carlos M.

    2016-08-01

    Biotic and abiotic factors influence the accumulation of organic carbon (Corg) in seagrass ecosystems. We surveyed Posidonia sinuosa meadows growing in different water depths to assess the variability in the sources, stocks and accumulation rates of Corg. We show that over the last 500 years, P. sinuosa meadows closer to the upper limit of distribution (at 2-4 m depth) accumulated 3- to 4-fold higher Corg stocks (averaging 6.3 kg Corg m-2) at 3- to 4-fold higher rates (12.8 g Corg m-2 yr-1) compared to meadows closer to the deep limits of distribution (at 6-8 m depth; 1.8 kg Corg m-2 and 3.6 g Corg m-2 yr-1). In shallower meadows, Corg stocks were mostly derived from seagrass detritus (88 % in average) compared to meadows closer to the deep limit of distribution (45 % on average). In addition, soil accumulation rates and fine-grained sediment content (< 0.125 mm) in shallower meadows (2.0 mm yr-1 and 9 %, respectively) were approximately 2-fold higher than in deeper meadows (1.2 mm yr-1 and 5 %, respectively). The Corg stocks and accumulation rates accumulated over the last 500 years in bare sediments (0.6 kg Corg m-2 and 1.2 g Corg m-2 yr-1) were 3- to 11-fold lower than in P. sinuosa meadows, while fine-grained sediment content (1 %) and seagrass detritus contribution to the Corg pool (20 %) were 8- and 3-fold lower than in Posidonia meadows, respectively. The patterns found support the hypothesis that Corg storage in seagrass soils is influenced by interactions of biological (e.g., meadow productivity, cover and density), chemical (e.g., recalcitrance of Corg stocks) and physical (e.g., hydrodynamic energy and soil accumulation rates) factors within the meadow. We conclude that there is a need to improve global estimates of seagrass carbon storage accounting for biogeochemical factors driving variability within habitats.

  2. Nature and significance of small volume fall deposits at composite volcanoes: Insights from the October 14, 1974 Fuego eruption, Guatemala

    NASA Astrophysics Data System (ADS)

    Rose, W. I.; Self, S.; Murrow, P. J.; Bonadonna, C.; Durant, A. J.; Ernst, G. G. J.

    2008-09-01

    The first of four successive pulses of the 1974 explosive eruption of Fuego volcano, Guatemala, produced a small volume (˜0.02 km3 DRE) basaltic sub-plinian tephra fall and flow deposit. Samples collected within 48 h after deposition over much of the dispersal area (7-80 km from the volcano) have been size analyzed down to 8 φ (4 µm). Tephra along the dispersal axis were all well-sorted ( σ φ = 0.25-1.00), and sorting increased whereas thickness and median grain size decreased systematically downwind. Skewness varied from slightly positive near the vent to slightly negative in distal regions and is consistent with decoupling between coarse ejecta falling off the rising eruption column and fine ash falling off the windblown volcanic cloud advecting at the final level of rise. Less dense, vesicular coarse particles form a log normal sub-population when separated from the smaller (Mdφ < 3φ or < 0.125 mm), denser shard and crystal sub-population. A unimodal, relatively coarse (Mdφ = 0.58φ or 0.7 mm σ φ = 1.2) initial grain size population is estimated for the whole (fall and flow) deposit. Only a small part of the fine-grained, thin 1974 Fuego tephra deposit has survived erosion to the present day. The initial October 14 pulse, with an estimated column height of 15 km above sea level, was a primary cause of a detectable perturbation in the northern hemisphere stratospheric aerosol layer in late 1974 to early 1975. Such small, sulfur-rich, explosive eruptions may substantially contribute to the overall stratospheric sulfur budget, yet leave only transient deposits, which have little chance of survival even in the recent geologic record. The fraction of finest particles (Mdφ = 4-8φ or 4-63 µm) in the Fuego tephra makes up a separate but minor size mode in the size distribution of samples around the margin of the deposit. A previously undocumented bimodal-unimodal-bimodal change in grain size distribution across the dispersal axis at 20 km downwind from the

  3. Experimental demonstration of passive acoustic imaging in the human skull cavity using CT-based aberration corrections

    PubMed Central

    Jones, Ryan M.; O’Reilly, Meaghan A.; Hynynen, Kullervo

    2015-01-01

    Purpose: Experimentally verify a previously described technique for performing passive acoustic imaging through an intact human skull using noninvasive, computed tomography (CT)-based aberration corrections Jones et al. [Phys. Med. Biol. 58, 4981–5005 (2013)]. Methods: A sparse hemispherical receiver array (30 cm diameter) consisting of 128 piezoceramic discs (2.5 mm diameter, 612 kHz center frequency) was used to passively listen through ex vivo human skullcaps (n = 4) to acoustic emissions from a narrow-band fixed source (1 mm diameter, 516 kHz center frequency) and from ultrasound-stimulated (5 cycle bursts, 1 Hz pulse repetition frequency, estimated in situ peak negative pressure 0.11–0.33 MPa, 306 kHz driving frequency) Definity™ microbubbles flowing through a thin-walled tube phantom. Initial in vivo feasibility testing of the method was performed. The performance of the method was assessed through comparisons to images generated without skull corrections, with invasive source-based corrections, and with water-path control images. Results: For source locations at least 25 mm from the inner skull surface, the modified reconstruction algorithm successfully restored a single focus within the skull cavity at a location within 1.25 mm from the true position of the narrow-band source. The results obtained from imaging single bubbles are in good agreement with numerical simulations of point source emitters and the authors’ previous experimental measurements using source-based skull corrections O’Reilly et al. [IEEE Trans. Biomed. Eng. 61, 1285–1294 (2014)]. In a rat model, microbubble activity was mapped through an intact human skull at pressure levels below and above the threshold for focused ultrasound-induced blood–brain barrier opening. During bursts that led to coherent bubble activity, the location of maximum intensity in images generated with CT-based skull corrections was found to deviate by less than 1 mm, on average, from the position obtained using source-based corrections. Conclusions: Taken together, these results demonstrate the feasibility of using the method to guide bubble-mediated ultrasound therapies in the brain. The technique may also have application in ultrasound-based cerebral angiography. PMID:26133635

  4. Pliocene-Quaternary syn-collision volcanism of the Javakheti Ridge, NW Armenia: impact on models of magma generation in the Arabia-Eurasia collision zone

    NASA Astrophysics Data System (ADS)

    Meliksetian, Kh.; Neill, I.; Allen, M. B.; Navarsardyan, G.; Karapetyan, S.

    2012-04-01

    The Armenian Highlands and Southern Caucasus formed during convergence and collision between the Arabian and Eurasian margins from the Late Mesozoic to the present. These events culminate in the growth of the present-day Turkish-Iranian high plateau. Pliocene-Quaternary magmatism followed plateau building, and is a key feature of the entire region. However, petrogenetic models are sparse, particularly for outcrops in the Armenia sector. Mantle-derived magmatism in Turkey has been linked to Tethyan slab break-off and/or lithospheric delamination following the Arabia-Eurasia collision. In this study we consider preliminary petrographic and geochemical results from the Javakheti ridge and surrounding areas, in NW Armenia, and their relationship to the orogenic plateau as a whole. The N-S trending Javakheti ridge is the southerly extension of the Samsari ridge in Georgia, and is one of several Pliocene-Quaternary volcanic uplands in Armenia and the Lesser Caucasus (e.g. Gegham, Vardenis and Syunik). The basement consists of the Sevan-Akera suture between the South Armenian Block, of Gondwanaland origin, and the Eurasian active margin and associated Mesozoic island arc of the Lesser Caucasus. Arc-continent collision and obduction occurred in the Late Cretaceous or Paleocene-Eocene. The first Pliocene-Quaternary magmatism in the area is represented by valley-filling fissure-fed basaltic flows, examples of which have been dated to ~2.7-2.0 Ma in Georgia and Armenia. The ridge itself consists of eroded intermediate to felsic flows forming a central volcanic complex. Recently published Ar-Ar dating of ash layers related to the complex reveal ages of ~1.8-1.9 Ma. The flows are cut by numerous Quaternary cinder cones. Volcanism on the ridge complex appears to young towards the north, and the ridge remains tectonically active, undergoing extension at 1.25 mm/yr, according to GPS data. Preliminary geochemical results indicate the valley-filling flows, the ridge, and cinder cones, are petrogenetically related, and form a continuum from silica under-saturated to over-saturated, indicating crustal assimilation during differentiation of mantle-derived magmas. The more primitive compositions strongly resemble those of the well-known centre Mt. Ararat, suggesting that similar petrogenetic circumstances and degrees of partial melting apply at both localities, despite their differing distance to the Arabia-Eurasia suture zone.

  5. Preliminary Results from a Late Pleistocene to Holocene Paleoclimate Study of the Lake Sediment Cores, Northern New Mexico

    NASA Astrophysics Data System (ADS)

    Cedillo, D. N.; Brister, A. R.; LoPresti, C. A.; Maldonado, M.; Pitrucha, R. M.; West, C.; Martinez, E.; Lineline, J.; Petronis, M. S.

    2011-12-01

    We present the preliminary results from an integrated, paleoclimatic study of sediment cores collected from the Las Vegas National Wildlife Refuge (LVNWR) and surrounding region that bear on the late Pleistocene to Holocene paleoclimatic variations in northeastern NM. We collected sedimentologic, midge fossil, and rock magnetic data from sediment cores to characterize the materials, identify stratigraphic changes, document shifting lake levels, assess temperature changes, and infer paleoclimate conditions. Data from McAllister and Wallace Lake are encouraging and reveal depth dependent changes in fossil assemblages, grain size, and rock magnetic properties that we interpret to reflect climatic driven variations impacting the depositional system. We recognize three different types of chironomid subfamilies (Chironomini, Tanypodinae, and Orthocladiinae). Based on the fossil results, the water has been warm in the most recent years. Grain size distribution from the lower to upper core levels reveal that the amount of fine sand-sized sediment (0.125 mm diameter) increases while the amount of medium (0.25) to coarse (0.50) sand-sized sediment decreases implying that there may have been a reduction in stream energy and hence precipitation over the time period represented by the core. Bulk low-field magnetic susceptibility decreases by an order of magnitude from the surface to the base of the measured core suggesting a change in detrital magnetic influx into the lacustrian system. Curie point estimates indicate that the dominant magnetic mineral in all samples is cubic, low-Ti titanomagnetite phase. We postulate that concurrent with alpine glacial activity during the Pleistocene, the LVNWR and the transitional Great Plains region to the northeast was an expansive single lake or interconnected lake system, analogous to the Pleistocene lakes of the Estancia Basin (Lake Estancia) and the Tularosa Basin (Lake Otero) of central and southern NM. Following the end of glacial

  6. Small Specimen Data from a High Temperature HFIR Irradiation Experiment

    SciTech Connect

    Burchell, Timothy D; McDuffee, Joel Lee; Thoms, Kenneth R

    2014-01-01

    The HTV capsule is a High Flux Isotope Reactor (HFIR) target-rod capsule designed to operate at very high temperatures. The graphite containing section of the capsule (in core) is approximately 18 inches (457.2 mm) long and is separated into eight temperature zones. The specimen diameters within each zone are set to achieve the desired gas gap and hence design temperature (900 C, 1200 C or 1500 C). The capsule has five zones containing 0.400 inch (10.16 mm) diameter specimens, two zones containing 0.350 inch (8.89 mm) diameter specimens and one zone containing 0.300 inch (7.62 mm) diameter specimens. The zones have been distributed within the experiment to optimize the gamma heating from the HFIR core as well as minimize the axial heat flow in the capsule. Consequently, there are two 900 C zones, three 1200 C zones, and three 1500 C zones within the HTV capsule. Each zone contains nine specimens 0.210 0.002 inches (5.334 mm) in length. The capsule will be irradiated to a peak dose of 3.17 displacements per atom. The HTV specimens include samples of the following graphite grades: SGL Carbon s NBG-17 and NBG-18, GrafTech s PCEA, Toyo Tanso s IG-110, Mersen s 2114 and the reference grade H-451 (SGL Carbon). As part of the pre-irradiation program the specimens were characterized using ASTM Standards C559 for bulk density, and ASTM C769 for approximate Young s modulus from the sonic velocity. The probe frequency used for the determination of time of flight of the ultrasonic signal was 2.25 MHz. Marked volume (specimen diameter) effects were noted for both bulk density (increased with increasing specimen volume or diameter) and Dynamic Young s modulus (decreased with increasing specimen volume or diameter). These trends are extended by adding the property vs. diameter data for unirradiated AGC-1 creep specimens (nominally 12.5 mm-diameter x 25.4 mm-length). The relatively large reduction in Dynamic Young s Modulus was surprising given the trend for increasing density with increasing volume. The graphite-filler particle size was noted to be influential in the volume dependency data, with finer grained graphites showing the least specimen volume/diameter effect. Here the volume dependency trends are discussed in terms of the graphite s filler-particle size and texture.

  7. Delivery of sry1, but not sry2, to the kidney increases blood pressure and sns indices in normotensive wky rats

    PubMed Central

    Ely, Daniel; Milsted, Amy; Dunphy, Gail; Boehme, Shannon; Dunmire, Jeff; Hart, Mike; Toot, Jonathon; Martins, Almir; Turner, Monte

    2009-01-01

    Background Our laboratory has shown that a locus on the SHR Y chromosome increases blood pressure (BP) in the SHR rat and in WKY rats with the SHR Y chromosome (SHR/y rat). A candidate for this Y chromosome hypertension locus is Sry, a gene that encodes a transcription factor responsible for testes determination. The SHR Y chromosome has six divergent Sry loci. The following study examined if exogenous Sry1 or Sry2 delivered to the kidney would elevate renal tyrosine hydroxylase, renal catecholamines, plasma catecholamines and telemetered BP over a 28 day period. We delivered 50 μg of either the expression construct Sry1/pcDNA 3.1, Sry2/pcDNA 3.1, or control vector into the medulla of the left kidney of normotensive WKY rats by electroporation. Weekly air stress was performed to determine BP responsiveness. Separate groups of animals were tested for renal function and plasma hormone patterns and pharmacological intervention using alpha adrenergic receptor blockade. Pre-surgery baseline and weekly blood samples were taken from Sry1 electroporated and control vector males for plasma renin, aldosterone, and corticosterone. BP was measured by telemetry and tyrosine hydroxylase and catecholamines by HPLC with electrochemical detection. Results In the animals receiving the Sry1 plasmid there were significant increases after 21 days in resting plasma norepinephrine (NE, 27%) and renal tyrosine hydroxylase content (41%, p < .05) compared to controls. BP was higher in animals electroporated with Sry1 (143 mmHg, p < .05) compared to controls (125 mmHg) between 2–4 weeks. Also the pressor response to air stress was significantly elevated in males electroporated with Sry1 (41 mmHg) compared to controls (28 mmHg, p < .001). Sry2 did not elevate BP or SNS indices and further tests were not done. The hormone profiles for plasma renin, aldosterone, and corticosterone between electroporated Sry1 and control vector males showed no significant differences over the 28 day period

  8. Revision of Minimally Invasive Sacroiliac Joint Fixation: Technical Considerations and Case Studies Using Decortication and Threaded Implant Fixation

    PubMed Central

    Fielding, Louis C

    2017-01-01

    Background Sacroiliac joint (SIJ) disease is increasingly recognized as a common source of low back pain. Arthrodesis of the SIJ has been shown to be clinically effective for this condition. In the last decade, minimally invasive (MI) SIJ fusion procedures have been developed to achieve the clinical effectiveness of open fusion procedures, with lower operative morbidity and faster recovery. However, SIJ fusion patients occasionally present with symptomatic nonunions necessitating revision. Methods Four patients who previously underwent MI SIJ arthrodesis returned with complaints of SIJ related pain confirmed by examination. Radiographic assessment showed lucency after fixation with triangular titanium interference implants. Loose implants were removed, and the patients were revised with a different MI SIJ fusion system that utilizes decortication, placement of autograft and graft extender, and fixation with cannulated threaded implants. The trajectory of the revision implants was in a more ventral-to-dorsal and caudal-to-cranial trajectory to place the implants perpendicularly through the articular portion of the SIJ. Results The triangular implants typically exhibited haloing lucency on radiographs and CT scans, and most were easily removed using the manufacturer’s instrumentation; only one implant was left in place as it was well-fixed. The removed implants exhibited little or no bony ongrowth. Decortication of the SIJ was performed, followed by placement of local autograft and fixation with 12.5 mm or 14.5mm diameter implants, as required. A more ventral-todorsal and caudal-to-cranial trajectory was established for the revision implants through the center of the articular region of the joint in order to maximize implant purchase in residual bone stock and achieve bony fusion through the articular portion of the SIJ. By six to twelve months post-revision, the presenting symptoms were successfully resolved in all patients. Conclusions Patients demonstrating symptomatic pseudoarthrosis after SIJ fixation surgery can be successfully revised with decortication, grafting and fixation with threaded implants utilizing MI surgical techniques. Implant trajectory is an important consideration for primary or revision MIS SIJ fusion. Studies with longer-term follow-up of both primary and revision procedures are needed to further understand fusion rates for both primary and revision procedures utilizing both triangular and threaded implant systems. PMID:28377866

  9. Geometric validation of self-gating k-space-sorted 4D-MRI vs 4D-CT using a respiratory motion phantom

    PubMed Central

    Yue, Yong; Fan, Zhaoyang; Yang, Wensha; Pang, Jianing; Deng, Zixin; McKenzie, Elizabeth; Tuli, Richard; Wallace, Robert; Li, Debiao; Fraass, Benedick

    2015-01-01

    Purpose: MRI is increasingly being used for radiotherapy planning, simulation, and in-treatment-room motion monitoring. To provide more detailed temporal and spatial MR data for these tasks, we have recently developed a novel self-gated (SG) MRI technique with advantage of k-space phase sorting, high isotropic spatial resolution, and high temporal resolution. The current work describes the validation of this 4D-MRI technique using a MRI- and CT-compatible respiratory motion phantom and comparison to 4D-CT. Methods: The 4D-MRI sequence is based on a spoiled gradient echo-based 3D projection reconstruction sequence with self-gating for 4D-MRI at 3 T. Respiratory phase is resolved by using SG k-space lines as the motion surrogate. 4D-MRI images are reconstructed into ten temporal bins with spatial resolution 1.56 × 1.56 × 1.56 mm3. A MRI-CT compatible phantom was designed to validate the performance of the 4D-MRI sequence and 4D-CT imaging. A spherical target (diameter 23 mm, volume 6.37 ml) filled with high-concentration gadolinium (Gd) gel is embedded into a plastic box (35 × 40 × 63 mm3) and stabilized with low-concentration Gd gel. The phantom, driven by an air pump, is able to produce human-type breathing patterns between 4 and 30 respiratory cycles/min. 4D-CT of the phantom has been acquired in cine mode, and reconstructed into ten phases with slice thickness 1.25 mm. The 4D images sets were imported into a treatment planning software for target contouring. The geometrical accuracy of the 4D MRI and CT images has been quantified using target volume, flattening, and eccentricity. The target motion was measured by tracking the centroids of the spheres in each individual phase. Motion ground-truth was obtained from input signals and real-time video recordings. Results: The dynamic phantom has been operated in four respiratory rate (RR) settings, 6, 10, 15, and 20/min, and was scanned with 4D-MRI and 4D-CT. 4D-CT images have target-stretching, partial-missing, and other motion artifacts in various phases, whereas the 4D-MRI images are visually free of those artifacts. Volume percentage difference for the 6.37 ml target ranged from 5.3% ± 4.3% to 10.3% ± 5.9% for 4D-CT, and 1.47 ± 0.52 to 2.12 ± 1.60 for 4D-MRI. With an increase of respiratory rate, the target volumetric and geometric deviations increase for 4D-CT images while remaining stable for the 4D-MRI images. Target motion amplitude errors at different RRs were measured with a range of 0.66–1.25 mm for 4D-CT and 0.2–0.42 mm for 4D-MRI. The results of Mann–Whitney tests indicated that 4D-MRI significantly outperforms 4D-CT in phase-based target volumetric (p = 0.027) and geometric (p < 0.001) measures. Both modalities achieve equivalent accuracy in measuring motion amplitude (p = 0.828). Conclusions: The k-space self-gated 4D-MRI technique provides a robust method for accurately imaging phase-based target motion and geometry. Compared to 4D-CT, the current 4D-MRI technique demonstrates superior spatiotemporal resolution, and robust resistance to motion artifacts caused by fast target motion and irregular breathing patterns. The technique can be used extensively in abdominal targeting, motion gating, and toward implementing MRI-based adaptive radiotherapy. PMID:26429253

  10. Geometric validation of self-gating k-space-sorted 4D-MRI vs 4D-CT using a respiratory motion phantom

    SciTech Connect

    Yue, Yong Yang, Wensha; McKenzie, Elizabeth; Tuli, Richard; Wallace, Robert; Fraass, Benedick; Fan, Zhaoyang; Pang, Jianing; Deng, Zixin; Li, Debiao

    2015-10-15

    Purpose: MRI is increasingly being used for radiotherapy planning, simulation, and in-treatment-room motion monitoring. To provide more detailed temporal and spatial MR data for these tasks, we have recently developed a novel self-gated (SG) MRI technique with advantage of k-space phase sorting, high isotropic spatial resolution, and high temporal resolution. The current work describes the validation of this 4D-MRI technique using a MRI- and CT-compatible respiratory motion phantom and comparison to 4D-CT. Methods: The 4D-MRI sequence is based on a spoiled gradient echo-based 3D projection reconstruction sequence with self-gating for 4D-MRI at 3 T. Respiratory phase is resolved by using SG k-space lines as the motion surrogate. 4D-MRI images are reconstructed into ten temporal bins with spatial resolution 1.56 × 1.56 × 1.56 mm{sup 3}. A MRI-CT compatible phantom was designed to validate the performance of the 4D-MRI sequence and 4D-CT imaging. A spherical target (diameter 23 mm, volume 6.37 ml) filled with high-concentration gadolinium (Gd) gel is embedded into a plastic box (35 × 40 × 63 mm{sup 3}) and stabilized with low-concentration Gd gel. The phantom, driven by an air pump, is able to produce human-type breathing patterns between 4 and 30 respiratory cycles/min. 4D-CT of the phantom has been acquired in cine mode, and reconstructed into ten phases with slice thickness 1.25 mm. The 4D images sets were imported into a treatment planning software for target contouring. The geometrical accuracy of the 4D MRI and CT images has been quantified using target volume, flattening, and eccentricity. The target motion was measured by tracking the centroids of the spheres in each individual phase. Motion ground-truth was obtained from input signals and real-time video recordings. Results: The dynamic phantom has been operated in four respiratory rate (RR) settings, 6, 10, 15, and 20/min, and was scanned with 4D-MRI and 4D-CT. 4D-CT images have target-stretching, partial-missing, and other motion artifacts in various phases, whereas the 4D-MRI images are visually free of those artifacts. Volume percentage difference for the 6.37 ml target ranged from 5.3% ± 4.3% to 10.3% ± 5.9% for 4D-CT, and 1.47 ± 0.52 to 2.12 ± 1.60 for 4D-MRI. With an increase of respiratory rate, the target volumetric and geometric deviations increase for 4D-CT images while remaining stable for the 4D-MRI images. Target motion amplitude errors at different RRs were measured with a range of 0.66–1.25 mm for 4D-CT and 0.2–0.42 mm for 4D-MRI. The results of Mann–Whitney tests indicated that 4D-MRI significantly outperforms 4D-CT in phase-based target volumetric (p = 0.027) and geometric (p < 0.001) measures. Both modalities achieve equivalent accuracy in measuring motion amplitude (p = 0.828). Conclusions: The k-space self-gated 4D-MRI technique provides a robust method for accurately imaging phase-based target motion and geometry. Compared to 4D-CT, the current 4D-MRI technique demonstrates superior spatiotemporal resolution, and robust resistance to motion artifacts caused by fast target motion and irregular breathing patterns. The technique can be used extensively in abdominal targeting, motion gating, and toward implementing MRI-based adaptive radiotherapy.

  11. Polwarth and Texel ewe parturition duration and its association with lamb birth asphyxia.

    PubMed

    Dutra, F; Banchero, G

    2011-10-01

    The objective of the present study was to test the hypothesis that parturition duration is related to birth asphyxia in lambs and that asphyxia affects newborn lamb viability and vigor. Two sire and dam genotypes (Texel: TX; Polwarth: PW) and their crosses were represented in the study. Eighty lambs (25 PW sire × PW dam, 13 TX × TX, 25 TX × PW, and 17 PW × TX) born to 69 grazing ewes were used. At birth, the log₁₀ length of the second stage of parturition, birth weight, placental weight, and several body measurements were recorded on all lambs, and jugular blood samples were analyzed with the i-Stat Portable Clinical Analyzer (Abbott, Montevideo, Uruguay). A modified Apgar viability score at birth and lamb behavior during their first hour of life were recorded. Brain weight, muscle:bone ratio, and bone density were recorded in 20 male lambs (5 from each breed group) that were euthanized and dissected 24 h after birth. Data were analyzed by linear regression, least squares ANOVA, and ordinal and binary logistic regressions. Mean blood gas and acid-base variables were 7.21 ± 0.09 for pH, 18.4 ± 9.8 mmHg for partial pressure of oxygen, 53 ± 12.5 mmHg for partial pressure of carbon dioxide, and -4 ± 5.1 mmol/L for extracellular fluid base excess. Parturition duration increased with birth weight (P < 0.001) and was shorter in TX ewes (P < 0.001), female lambs (P < 0.05), twins (P < 0.09), and twin females (sex × litter size interaction, P < 0.02). Twenty-six (32.9%) lambs were born asphyxiated (pO₂ < 10 mmHg or pH <7.1). Parturition duration increased the risk of asphyxia (P < 0.001), decreased the viability score (P < 0.001), and increased the latency to suckle the udder (P < 0.05). Twin-born lambs presented at birth a 16-fold greater risk of asphyxia (P < 0.01) and reduced placental efficiency (P < 0.05). Texel-sired lambs appeared immature at birth, with less bone density (P < 0.05), smaller brain (P < 0.05), shorter forelimbs (P < 0.05), greater anterior (P < 0.001) and posterior (P < 0.05) neck circumference, and greater muscle:bone ratio (P < 0.05). Immaturity may explain greater TX biotype survival. Together these results demonstrate that a relationship exists between parturition duration, neonatal viability and behavior, and acid-base balance values in single- and twin-born lambs, suggesting that birth asphyxia is an important risk factor in perinatal lamb mortality.

  12. FGDC Digital Cartographic Standard for Geologic Map Symbolization (PostScript Implementation)

    USGS Publications Warehouse

    ,

    2006-01-01

    standard, provided that it is clearly explained on the map and in the database. In addition, modifying the size, color, and (or) lineweight of an existing symbol to suit the needs of a particular map or output device also is permitted, provided that the modified symbol's appearance is not too similar to another symbol on the map. Be aware, however, that reducing lineweights below .125 mm (.005 inch) may cause symbols to plot incorrectly if output at higher resolutions (1800 dpi or higher). For guidelines on symbol usage, as well as on color design and map labeling, please refer to the standard's introductory text. Also found there are informational sections covering concepts of geologic mapping and some definitions of geologic map features, as well as sections on the newly defined concepts and terminology for the scientific confidence and locational accuracy of geologic map features. More information on both the past development and the future maintenance of the FGDC Digital Cartographic Standard for Geologic Map Symbolization can be found at the FGDC Geologic Data Subcommittee website (http://ngmdb.usgs.gov/fgdc_gds/). Earlier Versions of the Standard

  13. Baseline plasma fibrinolysis and its correlation with clinical manifestations in patients with Raynaud's phenomenon.

    PubMed Central

    Lau, C S; McLaren, M; Mackay, I; Belch, J J

    1993-01-01

    OBJECTIVES--(1) To assess if patients with various forms of Raynaud's phenomenon (RP) have abnormal plasma fibrinolysis that may contribute to diminished digital blood flow; (2) to assess whether patients with RP with evidence of endothelial damage have abnormal plasma fibrinolysis; (3) to determine the clinical relevance of abnormalities, if any, in plasma fibrinolysis in patients with RP. METHODS--One hundred and sixty eight patients with significant RP were studied--46 had primary Raynaud's disease (RD), 32 had suspected Raynaud's syndrome secondary to an undifferentiated connective tissue disorder (undifferentiated CTD), 25 had Raynaud's syndrome associated with atherosclerosis (athero RS), and 65 had an underlying connective tissue disease (CTD RS). All attended in the morning after a low fat light breakfast. After a clinical history was obtained, venous blood samples were collected without stasis for assays of plasma fibrinolysis and factor VIII von Willebrand factor antigen (fVIII vWF Ag). Results were compared with those obtained from normal subjects matched for sex and age. As patients with athero RS were significantly older than the other patients with Raynaud's phenomenon, two groups of control subjects were recruited--namely, 'old' and 'young' control subjects. RESULTS--Patients with CTD RS and athero RS had higher concentrations of fVIII vWF Ag (CTD RS median 174.5 range (45-370)% v 100 (38-202)%, p < 0.001; athero RS 182-5 (100-240)% v 100 (50-158)%, p < 0.001). Both had raised fibrinogen (CTD RS 3.25 (1.9-6.8) g/l v 2.4 (1.2-4.2) g/l, p < 0.001; athero RS 3.4 (2.2-6.2) g/l v 2.5 (1.8-3.9) g/l, p < 0.001) and both had diminished fibrinolysis with reduced plasminogen activator activity (CTD RS 79.5 (31-72) mm2 v 92 (37-197) mm2, p < 0.04; athero RS 73 (45-125) mm2 v 98 (41-197) mm2, p < 0.03). Patients with CTD RS also had raised plasminogen activity (3.3 (2.3-5.8) cU/ml v 2.9 (1.5-5.4) cU/ml, p < 0.001). On the contrary, patients with primary RD and

  14. Optimizing strength and fracture toughness of a cast titanium alloy through heat treatment and microstructure control

    NASA Astrophysics Data System (ADS)

    Robinson, Amy C.

    The relationship between the microstructure and tensile ductility and fracture toughness for cast Ti-5111 was determined and compared to that of hot-rolled and annealed Ti-5111. Graphite mold cast Ti-5111 plate material was examined in the as-received condition and after six different heat treatments involving elevated temperature anneals followed by an air or furnace cool. Three investment cast Ti-5111 plates were also examined after annealing followed by either a fan cool, air cool, or furnace cool. All castings developed a lamellar colony microstructure consisting of aligned lamellae of alpha and beta phases. Altering the cooling rate from the annealing temperature had the most influence on the microstructure such that plates with a slower cooling rate typically developed coarser grain boundary alpha, larger alpha colonies, thicker alpha laths, and greater volume fractions of alpha phase. The average prior beta grain size for the graphite mold cast specimens ranged from 920 mum to 1360 mum, while that for the investment cast specimens was approximately 1750 mum. The tensile behavior of the castings was characterized by a crack initiation and propagation process where the ductility was often limited by the strain required to initiate a large crack. The cracks formed along planar slip bands that crossed alpha colonies or in some cases, entire prior beta grains. Thus, reducing the alpha colony size and prior beta grain size should improve the casting ductility by limiting the length of slip-induced cracks. Due to the large grain and colony sizes present in the castings, the strength and ductility was observed to be sensitive to specimen size such that a smaller tensile diameter (i.e. 3.2 mm as compared to 12.5 mm) decreased the tensile and yield strengths due to the high fraction of large grains located on the specimen surface that can yield by predominantly single slip. The scatter in ductility values in the smaller specimens was significantly greater as a result of fracture controlled by a crack initiation and propagation process within a single grain that comprises a large fraction of the specimen cross-section. Thus, once a large crack initiated, minimal additional strain was required to propagate the crack. Both intrinsic and extrinsic toughening mechanisms were apparent in the fracture toughness study of the castings. The fracture initiation toughness was enhanced by secondary cracking and significant blunting at the crack tip as evidenced by the presence of strain-induced void formation within a large process zone. Large alpha colonies located at the transition between the fatigue pre-crack and tensile crack growth regions limited the fracture initiation toughness by promoting easy crack growth along a significant fraction of the crack front. Thus, limiting the alpha colony size should enhance the fracture initiation toughness. The best crack propagation resistance (tearing modulus) was observed from specimens with large alpha colonies and large prior beta grains. Enhancing the size of these features increased the surface roughness, and consequently the tearing modulus, due to greater crack deflection, crack bifurcation, and shear ligament toughening from the larger alpha colonies and prior beta grains. Crack bridging by the ductile beta phase was also observed and should enhance the tearing modulus. When compared to the hot-rolled and annealed plate, the graphite mold castings exhibited better fracture initiation toughness and crack propagation resistance. However, the wrought plate maintained relatively good fracture initiation toughness and crack propagation resistance as a result of the continuous ductile beta matrix present in the microstructure.

  15. Some controversies in endovenous laser ablation of varicose veins addressed by optical-thermal mathematical modeling.

    PubMed

    Poluektova, Anna A; Malskat, Wendy S J; van Gemert, Martin J C; Vuylsteke, Marc E; Bruijninckx, Cornelis M A; Neumann, H A Martino; van der Geld, Cees W M

    2014-03-01

    Minimally invasive treatment of varicose veins by endovenous laser ablation (EVLA) becomes more and more popular. However, despite significant research efforts performed during the last years, there is still a lack of agreement regarding EVLA mechanisms and therapeutic strategies. The aim of this article is to address some of these controversies by utilizing optical-thermal mathematical modeling. Our model combines Mordon's light absorption-based optical-thermal model with the thermal consequences of the thin carbonized blood layer on the laser fiber tip that is heated up to temperatures of around 1,000 °C due to the absorption of about 45% of the laser light. Computations were made in MATLAB. Laser wavelengths included were 810, 840, 940, 980, 1,064, 1,320, 1,470, and 1,950 nm. We addressed (a) the effect of direct light absorption by the vein wall on temperature behavior, comparing computations by using normal and zero wall absorption; (b) the prediction of the influence of wavelength on the temperature behavior; (c) the effect of the hot carbonized blood layer surrounding the fiber tip on temperature behavior, comparing wall temperatures from using a hot fiber tip and one kept at room temperature; (d) the effect of blood emptying the vein, simulated by reducing the inside vein diameter from 3 down to 0.8 mm; (e) the contribution of absorbed light energy to the increase in total energy at the inner vein wall in the time period where the highest inner wall temperature was reached; (f) the effect of laser power and pullback velocity on wall temperature of a 2-mm inner diameter vein, at a power/velocity ratio of 30 J/cm at 1,470 nm; (g) a comparison of model outcomes and clinical findings of EVLA procedures at 810 nm, 11 W, and 1.25 mm/s, and 1,470 nm, 6 W, and 1 mm/s, respectively. Interestingly, our model predicts that the dominating mechanism for heating up the vein wall is not direct absorption of the laser light by the vein wall but, rather, heat flow to the vein wall and its subsequent temperature increase from two independent heat sources. The first is the exceedingly hot carbonized layer covering the fiber tip; the second is the hot blood surrounding the fiber tip, heated up by direct absorption of the laser light. Both mechanisms are about equally effective for all laser wavelengths. Therefore, our model concurs the finding of Vuylsteke and Mordon (Ann Vasc Surg 26:424-433, 2012) of more circumferential vein wall injury in veins (nearly) devoid of blood, but it does not support their proposed explanation of direct light absorption by the vein wall. Furthermore, EVLA appears to be a more efficient therapy by the combination of higher laser power and faster pullback velocity than by the inverse combination. Our findings suggest that 1,470 nm achieves the highest EVLA efficacy compared to the shorter wavelengths at all vein diameters considered. However, 1,950 nm of EVLA is more efficacious than 1,470 nm albeit only at very small inner vein diameters (smaller than about 1 mm, i.e., veins quite devoid of blood). Our model confirms the efficacy of both clinical procedures at 810 and 1,470 nm. In conclusion, our model simulations suggest that direct light absorption by the vein wall is relatively unimportant, despite being the supposed mechanism of action of EVLA that drove the introduction of new lasers with different wavelengths. Consequently, the presumed advantage of wavelengths targeting water rather than hemoglobin is flawed. Finally, the model predicts that EVLA therapy may be optimized by using 1,470 nm of laser light, emptying of the vein before treatment, and combining a higher laser power with a greater fiber tip pullback velocity.

  16. Active deformation in the Northern Walker Lane: a detailed geodetic study of the Mohawk Valley and Honey Lake/Warm Springs fault systems

    NASA Astrophysics Data System (ADS)

    Bormann, J. M.; Hammond, W. C.; Kreemer, C. W.; Blewitt, G.

    2012-12-01

    The Mohawk Valley and Honey Lake/Warm Springs faults are parallel, northwest striking, dextral fault systems separated by ~50 km in the westernmost part of the Northern Walker Lane. These two faults work as a cooperative pair to accommodate 3-5 mm/yr of the total 8 mm/yr of right-lateral deformation geodetically observed across the Northern Walker Lane, however it is unclear with fault is dominant. Geologic studies of the faults result in right-lateral slip rates of 1-2.5 mm/yr on the Honey Lake fault and a minimum of 0.3 mm/yr on the Mohawk Valley fault. In contrast, previous geodetic studies estimate slip rates of ~1 mm/yr on the Honey Lake fault and ~3 mm/yr on the Mohawk Valley fault. To reconcile the discrepancy between the distribution of slip on the faults and the differences between sums of the geologically and geodetically estimated slip rates, we use new GPS data to constrain an elastic block model developed specifically to study the Mohawk Valley and Honey Lake/Warm Springs fault systems. We present a dense GPS velocity solution (~10 km average station spacing) that incorporates new data from the semi-continuous Mobile Array of GPS for Nevada Transtension network (MAGNET, http://geodesy.unr.edu/networks) operated by the University of Nevada, Reno with continuous data from the EarthScope Plate Boundary Observatory and other networks. Data collected during the summer of 2012 bring many MAGNET GPS time series in the Northern Walker Lane to near 5 years in duration. The density of our velocity field and recent advances in data processing give us unprecedented precision in the measurement of contemporary deformation in the Northern Walker Lane. We use the velocity solution to solve for slip rates on the companion fault systems and explore the effects of block model geometry assumptions and tradeoffs. Our model predicts slip rates of 2.2±0.3 mm/yr for the Mohawk Valley fault and 1.1±0.2 mm/yr for the Honey Lake fault. Block model slip rate estimates are sensitive to slip rate estimates on neighboring faults. We use a grid-search approach with dextral slip rates on the Mohawk Valley and Honey Lake faults set a priori to test the effect of different slip rate combinations on model misfit. Model misfit is most sensitive to variations in the Mohawk Valley slip rate, with right-lateral slip rates of 1.5-3.5 mm/yr being preferred. Model misfit is less affected by variations in the Honey Lake slip rate, with right-lateral slip rates between 0-3.5 mm/yr resulting in the lowest misfit. Both the misfit test and our slip rate results support the conclusion of previous geodetic studies that the Mohawk Valley fault is currently the dominant fault accommodating right-lateral deformation in the Northern Walker Lane.

  17. Sediment budget for a polluted Hawaiian reef using hillslope monitoring and process mapping (Invited)

    NASA Astrophysics Data System (ADS)

    Stock, J. D.; Rosener, M.; Schmidt, K. M.; Hanshaw, M. N.; Brooks, B. A.; Tribble, G.; Jacobi, J.

    2010-12-01

    Pollution from coastal watersheds threatens the ecology of the nearshore, including tropical reefs. Suspended sediment concentrations off the reefs of Molokai, Hawaii, chronically exceed a toxic 10 mg/L, threatening reef ecosystems. We hypothesize that historic conversion of hillslope processes from soil creep to overland flow increased both magnitude and frequency of erosion. To create a process sediment budget, we used surficial and ecological mapping, hillslope and stream gages, and novel sensors to locate, quantify and model the generation of fine sediments polluting the reef. Ecological and geomorphic mapping from LiDAR and multi-spectral imagery located overland flow areas with vegetation cover below a threshold preventing erosion. Here, feral goat grazing exposed volcanic soils whose low matrix hydraulic conductivities (1-25 mm/hour) promote Horton overland flow. We instrumented steep, barren hillslopes with soil moisture sensors, overland flow meters, Parshal flumes, ISCO sediment samplers, and a rain gage and conducted repeat Tripod LiDAR and infiltration tests. To characterize soil resistance to overland flow erosion, we used a Cohesive Strength Meter (CSM) to simulate water stress. At the 13.5 km 2 watershed mouth we used a USGS stream gage with an ISCO sediment sampler to estimate total load. Over 3 years, storms triggered overland flow during rainfall intensities above 10-15 mm/hr. Overland flow meters indicate such flows can be up to 3 cm deep, with a tendency to deepen downslope. CSM tests indicate that these depths are insufficient to erode soils where vegetation is dense, but far above threshold values of 2-3 mm for bare soils. Sediment ratings curves for both hillslope and downstream catchment gages show clock-wise hysteresis during the first intense storms in the fall, becoming linear later in the season. During fall storms, sediment concentration is often 10X higher at a given stage. Revised annual lowering rates from experimental hillslopes are 1.5 cm/a (erosion pins), 1.4 cm/a (suspended sediment) and 1.6 cm/a (repeat Tripod LiDAR). These rates are at least 100-fold greater than the long-term river lowering rate of 0.13 mm/a. A sediment budget constructed by extrapolating hillslope lowering rates to the portions of the catchments mapped as unvegetated overland flow predicts a total yearly flux of ~ 6500 t, in agreement with the measured total of ~6200 t. Decadal records illustrate that rainfall intensities sufficient to generate overland flow occur for at least 8-10 hours every year, coincident with 1-3 large storm events. We hypothesize that high lowering rates reflect a combination of long-duration overland flow events, and availability of weathered soils that can be entrained by thin flow. It appears that generation of loose, seasonally weathered silt is a 1st order control on the amount of sediment exported to the reef. If climate change increases storm frequency or duration, or decreases vegetation cover, sediment loading to reefs could increase dramatically.

  18. Role of GABAergic neurones in the nucleus tractus solitarii in modulation of cardiovascular activity.

    PubMed

    Zubcevic, Jasenka; Potts, Jeffrey T

    2010-09-01

    GABAergic neurones are interspersed throughout the nucleus tractus solitarii (NTS), and their tonic activity is crucial to the maintenance of cardiorespiratory homeostasis. However, the mechanisms that regulate the magnitude of GABAergic inhibition in the NTS remain unknown. We hypothesized that the level of GABAergic inhibition is proportionally regulated by the level of excitatory synaptic input to the NTS from baroreceptors. Using the in situ working heart-brainstem preparation in normotensive and spontaneously hypertensive rats, we blocked GABA(A) receptor-mediated neurotransmission in the NTS with gabazine (a specific GABA(A) receptor antagonist) at two levels of perfusion pressure (low PP, 60-70 mmHg; and high PP, 105-125 mmHg) while monitoring the immediate changes in cardiorespiratory variables. In normotensive rats, gabazine produced an immediate bradycardia consistent with disinhibition of NTS circuit neurones that regulate heart rate (HR) which was proportional to the level of arterial pressure (HR at low PP, 57 +/- 9 beats min(1); at high PP, 177 +/- 9 beats min(1); P < 0.001), suggesting that GABAergic circuitry in the NTS modulating heart rate was arterial pressure dependent. In contrast, there was no significant difference in the magnitude of gabazine-induced bradycardia in spontaneously hypertensive rats at low or high PP (HR at low PP, 45 +/- 10 beats min(1); at high PP, 58 +/- 7 beats min(1)). With regard to thoracic sympathetic nerve activity (tSNA), at high PP there was a significant reduction in tSNA during the inspiratory (I) phase of the respiratory cycle, but only in the normotensive rat (tSNA = 18.7 +/- 10%). At low PP, gabazine caused an elevation of the postinspiration phase of tSNA in both normotensive (tSNA = 23.7 +/- 2.9%) and hypertensive rats (tSNA = 44.2 +/- 14%). At low PP, gabazine produced no change in tSNA during the mid-expiration phase in either rat strain, but at high PP we observed a significant reduction in the mid

  19. WABASH RIVER IMPPCCT, INTEGRATED METHANOL AND POWER PRODUCTION FROM CLEAN COAL TECHNOLOGIES

    SciTech Connect

    Doug Strickland

    2001-09-28

    In a joint effort with the U.S. Department of Energy, working under a Cooperative Agreement Award from the ''Early Entrance Coproduction Plant'' (EECP) initiative, the Gasification Engineering Corporation and an Industrial Consortium are investigating the application of synthesis gas from the E-GAS{trademark} technology to a coproduction environment to enhance the efficiency and productivity of solid fuel gasification combined cycle power plants. The objectives of this effort are to determine the feasibility of an Early Entrance Coproduction Plant located at a specific site which produces some combination of electric power (or heat), fuels, and/or chemicals from synthesis gas derived from coal, or, coal in combination with some other carbonaceous feedstock. The project's intended result is to provide the necessary technical, financial, and environmental information that will be needed to move the EECP forward to detailed design, construction, and operation by industry. The Wabash River Integrated Methanol and Power Production from Clean Coal Technologies (IMPPCCT) project is evaluating integrated electrical power generation and methanol production through clean coal technologies. The project is conducted by a multi-industry team lead by Gasification Engineering Corporation (GEC), and supported by Air Products and Chemicals Inc., The Dow Chemical Company, Dow Corning Corporation, Methanex Corporation, and Siemens Westinghouse Power Corporation. Three project phases are planned for execution, including: (1) Feasibility Study and conceptual design for an integrated demonstration facility and for fence-line commercial plants operated at The Dow Chemical Company or Dow Corning Corporation chemical plant locations (i.e. the Commercial Embodiment Plant or CEP) (2) Research, development, and testing to address any technology gaps or critical design and integration issues (3) Engineering design and financing plan to install an integrated commercial demonstration facility at the existing Wabash River Energy Ltd., plant in West Terre Haute, Indiana. During the reporting period work was furthered to support the development of capital and operating cost estimates associated with the installation of liquid or gas phase methanol synthesis technology in a Commercial Embodiment Plant (CEP) utilizing the six cases previously defined. In addition, continued development of the plant economic model was accomplished by providing combined cycle performance data. Performance and emission estimates for gas turbine combined cycles was based on revised methanol purge gas information. The economic model was used to evaluate project returns with various market conditions and plant configurations and was refined to correct earlier flaws. Updated power price projections were obtained and incorporated in the model. Sensitivity studies show that break-even methanol prices which provide a 12% return are 47-54 cents/gallon for plant scenarios using $1.25/MM Btu coal, and about 40 cents/gallon for most of the scenarios with $0.50/MM Btu petroleum coke as the fuel source. One exception is a high power price and production case which could be economically attractive at 30 cents/gallon methanol. This case was explored in more detail, but includes power costs predicated on natural gas prices at the 95th percentile of expected price distributions. In this case, the breakeven methanol price is highly sensitive to the required project return rate, payback period, and plant on-line time. These sensitivities result mainly from the high capital investment required for the CEP facility ({approx}$500MM for a single train IGCC-methanol synthesis plant). Finally, during the reporting period the Defense Contractor Audit Agency successfully executed an accounting audit of Global Energy Inc. for data accumulated over the first year of the IMPPCCT project under the Cooperative Agreement.

  20. Automatic tracking of arbitrarily shaped implanted markers in kilovoltage projection images: A feasibility study

    SciTech Connect

    Regmi, Rajesh; Lovelock, D. Michael; Hunt, Margie; Zhang, Pengpeng; Pham, Hai; Xiong, Jianping; Yorke, Ellen D.; Mageras, Gig S.; Goodman, Karyn A.; Rimner, Andreas; Mostafavi, Hassan

    2014-07-15

    Purpose: Certain types of commonly used fiducial markers take on irregular shapes upon implantation in soft tissue. This poses a challenge for methods that assume a predefined shape of markers when automatically tracking such markers in kilovoltage (kV) radiographs. The authors have developed a method of automatically tracking regularly and irregularly shaped markers using kV projection images and assessed its potential for detecting intrafractional target motion during rotational treatment. Methods: Template-based matching used a normalized cross-correlation with simplex minimization. Templates were created from computed tomography (CT) images for phantom studies and from end-expiration breath-hold planning CT for patient studies. The kV images were processed using a Sobel filter to enhance marker visibility. To correct for changes in intermarker relative positions between simulation and treatment that can introduce errors in automatic matching, marker offsets in three dimensions were manually determined from an approximately orthogonal pair of kV images. Two studies in anthropomorphic phantom were carried out, one using a gold cylindrical marker representing regular shape, another using a Visicoil marker representing irregular shape. Automatic matching of templates to cone beam CT (CBCT) projection images was performed to known marker positions in phantom. In patient data, automatic matching was compared to manual matching as an approximate ground truth. Positional discrepancy between automatic and manual matching of less than 2 mm was assumed as the criterion for successful tracking. Tracking success rates were examined in kV projection images from 22 CBCT scans of four pancreas, six gastroesophageal junction, and one lung cancer patients. Each patient had at least one irregularly shaped radiopaque marker implanted in or near the tumor. In addition, automatic tracking was tested in intrafraction kV images of three lung cancer patients with irregularly shaped markers during 11 volumetric modulated arc treatments. Purpose-built software developed at our institution was used to create marker templates and track the markers embedded in kV images. Results: Phantom studies showed mean ± standard deviation measurement uncertainty of automatic registration to be 0.14 ± 0.07 mm and 0.17 ± 0.08 mm for Visicoil and gold cylindrical markers, respectively. The mean success rate of automatic tracking with CBCT projections (11 frames per second, fps) of pancreas, gastroesophageal junction, and lung cancer patients was 100%, 99.1% (range 98%–100%), and 100%, respectively. With intrafraction images (approx. 0.2 fps) of lung cancer patients, the success rate was 98.2% (range 97%–100%), and 94.3% (range 93%–97%) using templates from 1.25 mm and 2.5 mm slice spacing CT scans, respectively. Correction of intermarker relative position was found to improve the success rate in two out of eight patients analyzed. Conclusions: The proposed method can track arbitrary marker shapes in kV images using templates generated from a breath-hold CT acquired at simulation. The studies indicate its feasibility for tracking tumor motion during rotational treatment. Investigation of the causes of misregistration suggests that its rate of incidence can be reduced with higher frequency of image acquisition, templates made from smaller CT slice spacing, and correction of changes in intermarker relative positions when they occur.

  1. Risk Assessment of Physiological Effects of Atmospheric Composition and Pressure in Constellation Vehicles

    NASA Technical Reports Server (NTRS)

    Scheuring, Richard A.; Conkin, Johnny; Jones, J. A.; Gernhardt, M.

    2007-01-01

    To limit the risk of fire and reduce denitrogenation time to prevent decompression sickness to support frequent extravehicular activities on the Moon, a hypobaric (PB = 414 mmHg) and mildly hypoxic (ppO2 = 132 mmHg, 32% O2 - 68% N2) living environment is considered for the Crew Exploration Vehicle (CEV) and Lunar Surface Access Module (LSAM). With acute change in ppO2 from 145-178 mmHg at standard vehicular operating pressure to less than 125 mmHg at desired lunar surface vehicular operating pressures, there is the possibility that some crewmembers may develop symptoms of Acute Mountain Sickness (AMS). The signs and symptoms of AMS (headache plus nausea, dizziness, fatigue, or sleeplessness), could impact crew health and performance on lunar surface missions. An exhaustive literature review on the topic of the physiological effects of reduced ppO2 and absolute pressure as may contribute to the development of altitude symptoms or AMS was performed. The results of the nine most rigorous studies were collated, analyzed and contents on AMS and hypoxia symptoms summarized. There is evidence for an absolute pressure effect per se on AMS, so the higher the altitude for a given hypoxic alveolar O2 partial pressure (PAO2), the greater the AMS response. About 25% of adults are likely to experience mild AMS near 2,000 m altitude following a rapid ascent from sea level while breathing air (6,500 feet, acute PAO2 = 75 mmHg). The operational experience with the Shuttle staged denitrogenation protocol at 528 mmHg (3,048 m) while breathing 26.5% O2 (acute PAO2 = 85 mmHg) in astronauts adapting to microgravity suggests a similar likely experience in the proposed CEV environment. We believe the risk of mild AMS is greater given a PAO2 of 77 mmHg at 4,876 m altitude while breathing 32% O2 than at 1,828 m altitude while breathing 21% O2. Only susceptible astronauts would develop mild and transient AMS with prolonged exposure to 414 mmHg (4,876 m) while breathing 32% O2 (acute PAO2

  2. Risk Assessment of Physiological Effects of Atmospheric Composition and Pressure in Constellation Vehicles

    NASA Technical Reports Server (NTRS)

    Scheuring, Richard A.; Conkin, Johnny; Jones, Jeffrey A.; Gernhardt, Michael L.

    2007-01-01

    To reduce denitrogenation time to prevent decompression sickness to support frequent extravehicular activities on the Moon, and to limit the risk of fire, a hypobaric (P(sub B) = 414 mmHg) and mildly hypoxic (ppO2 = 132 mmHg, 32% O2 - 68% N2) living environment is being considered during lunar missions for the Crew Exploration Vehicle (CEV) and Lunar Surface Access Module (LSAM). If the vehicular ppO2 is acutely changed from 145-178 mmHg at standard vehicular operating pressure to less than 125 mmHg at desired lunar surface outpost operating pressures, there is the possibility that some crewmembers may develop symptoms of Acute Mountain Sickness (AMS). The signs and symptoms of AMS (headache plus nausea, dizziness, fatigue, or sleeplessness), could impact crew health and performance on lunar surface missions. Methods: An exhaustive literature review on the topic of the physiological effects of reduced ppO2 and absolute pressure as may contribute to the development of hypoxia and altitude symptoms or AMS. The results of the nine most rigorous studies were collated, analyzed and contents on the physiological concerns associated with hypobaric operations, AMS and hypoxia symptoms summarized. Results: Although space vehicles have operated in hypobaric conditions previously, they have not operated in a mildly hypoxic ppO2. There is evidence for an absolute pressure effect per se on AMS, such that the higher the altitude for a given hypoxic alveolar O2 partial pressure (P(sub A)O2), the greater the likelihood of an AMS response. About 25% of adults are likely to experience mild AMS near 2,000 m (xxx mmHg) altitude following a rapid ascent from sea level while breathing air (6,500 feet, acute (P(sub A)O2) = 75 mmHg). The operational experience with the Shuttle staged denitrogenation protocol at 528 mmHg (3,048 m) while breathing 26.5% O2 (acute (P(sub A)O2) = 85 mmHg) in astronauts adapting to microgravity suggests a similar likely experience in the proposed CEV

  3. Recurring features of extreme rainfall events close to Veneto coast during autumn

    NASA Astrophysics Data System (ADS)

    Monai, M.; Barbi, A.; Racca, R.

    2010-09-01

    warm air coming from Adriatic sea, that is still warm (sea surface temperature above 20°C) in September; - previous weather conditions (7-10 days) with anticyclonic situation (frequently a ridge from north-Africa) with temperatures higher than usual. During most intense phases, recurring features were evidenced: - convective rains with significant thunderstorm activity; such systems are often associated to regeneration of cells, in the same coastal area; - convergence lines at low levels associated with winds coming from SE (from the sea) on the coast, and from NE (from the plane) immediately inland. It is particularly important to underline that rainfall values on short periods were extremely high if compared with mean annual amount: during last four episodes , rainfall amounts between 130 and 320 mm were recorded in 12 hours, i.e. during half a day something like 1/8 and 1/3 of total mean annual amount has fallen. Remarkable also intensity of rainfall : values like 90 mm in half an hour, or 125 mm in 1 hour were recorded. The final goal of this study was to better understand meteorological conditions associated with such events to improve forecasting and nowcasting skill. This is a crucial benefit for a Regional Met Service that must alert and support civil defence system properly, as is the case for Meteorological Centre of ARPAV in Veneto. Furthermore it is important to underline the fact that coastal area of Veneto is densely populated and it is one of the most important areas of Italian tourism, including the city of Venice and several seaside resorts with more than twenty millions of presences per year.

  4. Assessment of individual organ doses in a realistic human phantom from neutron and gamma stimulated spectroscopy of the breast and liver

    SciTech Connect

    Belley, Matthew D.; Segars, William Paul; Kapadia, Anuj J.

    2014-06-15

    Purpose: Understanding the radiation dose to a patient is essential when considering the use of an ionizing diagnostic imaging test for clinical diagnosis and screening. Using Monte Carlo simulations, the authors estimated the three-dimensional organ-dose distribution from neutron and gamma irradiation of the male liver, female liver, and female breasts for neutron- and gamma-stimulated spectroscopic imaging. Methods: Monte Carlo simulations were developed using the Geant4 GATE application and a voxelized XCAT human phantom. A male and a female whole body XCAT phantom was voxelized into 256 × 256 × 600 voxels (3.125 × 3.125 × 3.125 mm{sup 3}). A monoenergetic rectangular beam of 5.0 MeV neutrons or 7.0 MeV photons was made incident on a 2 cm thick slice of the phantom. The beam was rotated at eight different angles around the phantom ranging from 0° to 180°. Absorbed dose was calculated for each individual organ in the body and dose volume histograms were computed to analyze the absolute and relative doses in each organ. Results: The neutron irradiations of the liver showed the highest organ dose absorption in the liver, with appreciably lower doses in other proximal organs. The dose distribution within the irradiated slice exhibited substantial attenuation with increasing depth along the beam path, attenuating to ∼15% of the maximum value at the beam exit side. The gamma irradiation of the liver imparted the highest organ dose to the stomach wall. The dose distribution from the gammas showed a region of dose buildup at the beam entrance, followed by a relatively uniform dose distribution to all of the deep tissue structures, attenuating to ∼75% of the maximum value at the beam exit side. For the breast scans, both the neutron and gamma irradiation registered maximum organ doses in the breasts, with all other organs receiving less than 1% of the breast dose. Effective doses ranged from 0.22 to 0.37 mSv for the neutron scans and 41 to 66 mSv for the gamma

  5. Establishing a process of irradiating small animal brain using a CyberKnife and a microCT scanner

    SciTech Connect

    Kim, Haksoo; Welford, Scott; Fabien, Jeffrey; Zheng, Yiran; Yuan, Jake; Brindle, James; Yao, Min; Lo, Simon; Wessels, Barry; Machtay, Mitchell; Sohn, Jason W.; Sloan, Andrew

    2014-02-15

    Purpose: Establish and validate a process of accurately irradiating small animals using the CyberKnife G4 System (version 8.5) with treatment plans designed to irradiate a hemisphere of a mouse brain based on microCT scanner images. Methods: These experiments consisted of four parts: (1) building a mouse phantom for intensity modulated radiotherapy (IMRT) quality assurance (QA), (2) proving usability of a microCT for treatment planning, (3) fabricating a small animal positioning system for use with the CyberKnife's image guided radiotherapy (IGRT) system, and (4)in vivo verification of targeting accuracy. A set of solid water mouse phantoms was designed and fabricated, with radiochromic films (RCF) positioned in selected planes to measure delivered doses. After down-sampling for treatment planning compatibility, a CT image set of a phantom was imported into the CyberKnife treatment planning system—MultiPlan (ver. 3.5.2). A 0.5 cm diameter sphere was contoured within the phantom to represent a hemispherical section of a mouse brain. A nude mouse was scanned in an alpha cradle using a microCT scanner (cone-beam, 157 × 149 pixels slices, 0.2 mm longitudinal slice thickness). Based on the results of our positional accuracy study, a planning treatment volume (PTV) was created. A stereotactic body mold of the mouse was “printed” using a 3D printer laying UV curable acrylic plastic. Printer instructions were based on exported contours of the mouse's skin. Positional reproducibility in the mold was checked by measuring ten CT scans. To verify accurate dose delivery in vivo, six mice were irradiated in the mold with a 4 mm target contour and a 2 mm PTV margin to 3 Gy and sacrificed within 20 min to avoid DNA repair. The brain was sliced and stained for analysis. Results: For the IMRT QA using a set of phantoms, the planned dose (6 Gy to the calculation point) was compared to the delivered dose measured via film and analyzed using Gamma analysis (3% and 3 mm). A passing rate of 99% was measured in areas of above 40% of the prescription dose. The final inverse treatment plan was comprised of 43 beams ranging from 5 to 12.5 mm in diameter (2.5 mm size increments are available up to 15 mm in diameter collimation). Using the Xsight Spine Tracking module, the CyberKnife system could not reliably identify and track the tiny mouse spine; however, the CyberKnife system could identify and track the fiducial markers on the 3D mold.In vivo positional accuracy analysis using the 3D mold generated a mean error of 1.41 mm ± 0.73 mm when fiducial markers were used for position tracking. Analysis of the dissected brain confirmed the ability to target the correct brain volume. Conclusions: With the use of a stereotactic body mold with fiducial markers, microCT imaging, and resolution down-sampling, the CyberKnife system can successfully perform small-animal radiotherapy studies.

  6. Multi-Segment Radius Measurement Using an Absolute Distance Meter Through a Null Assembly

    NASA Technical Reports Server (NTRS)

    Merle, Cormic; Wick, Eric; Hayden, Joseph

    2011-01-01

    This system was one of the test methods considered for measuring the radius of curvature of one or more of the 18 segmented mirrors that form the 6.5 m diameter primary mirror (PM) of the James Webb Space Telescope (JWST). The assembled telescope will be tested at cryogenic temperatures in a 17-m diameter by 27-m high vacuum chamber at the Johnson Space Center. This system uses a Leica Absolute Distance Meter (ADM), at a wavelength of 780 nm, combined with beam-steering and beam-shaping optics to make a differential distance measurement between a ring mirror on the reflective null assembly and individual PM segments. The ADM is located inside the same Pressure-Tight Enclosure (PTE) that houses the test interferometer. The PTE maintains the ADM and interferometer at ambient temperature and pressure so that they are not directly exposed to the telescope s harsh cryogenic and vacuum environment. This system takes advantage of the existing achromatic objective and reflective null assembly used by the test interferometer to direct four ADM beamlets to four PM segments through an optical path that is coincident with the interferometer beam. A mask, positioned on a linear slide, contains an array of 1.25 mm diameter circular subapertures that map to each of the 18 PM segments as well as six positions around the ring mirror. A down-collimated 4 mm ADM beam simultaneously covers 4 adjacent PM segment beamlets and one ring mirror beamlet. The radius, or spacing, of all 18 segments can be measured with the addition of two orthogonally-oriented scanning pentaprisms used to steer the ADM beam to any one of six different sub-aperture configurations at the plane of the ring mirror. The interferometer beam, at a wavelength of 687 nm, and the ADM beamlets, at a wavelength of 780 nm, pass through the objective and null so that the rays are normally incident on the parabolic PM surface. After reflecting off the PM, both the ADM and interferometer beams return to their respective instruments on nearly the same path. A fifth beamlet, acting as a differential reference, reflects off a ring mirror attached to the objective and null and returns to the ADM. The spacings between the ring mirror, objective, and null are known through manufacturing tolerances as well as through an in situ null wavefront alignment of the interferometer test beam with a reflective hologram located near the caustic of the null. Since total path length between the ring mirror and PM segments is highly deterministic, any ADM-measured departures from the predicted path length can be attributed to either spacing error or radius error in the PM. It is estimated that the path length measurement between the ring mirror and a PM segment is accurate to better than 100 m. The unique features of this invention include the differential distance measuring capability and its integration into an existing cryogenic and vacuum compatible interferometric optical test.

  7. SAAO's new robotic telescope and WiNCam (Wide-field Nasmyth Camera)

    NASA Astrophysics Data System (ADS)

    Worters, Hannah L.; O'Connor, James E.; Carter, David B.; Loubser, Egan; Fourie, Pieter A.; Sickafoose, Amanda; Swanevelder, Pieter

    2016-08-01

    The South African Astronomical Observatory (SAAO) is designing and manufacturing a wide-field camera for use on two of its telescopes. The initial concept was of a Prime focus camera for the 74" telescope, an equatorial design made by Grubb Parsons, where it would employ a 61mmx61mm detector to cover a 23 arcmin diameter field of view. However, while in the design phase, SAAO embarked on the process of acquiring a bespoke 1-metre robotic alt-az telescope with a 43 arcmin field of view, which needs a homegrown instrument suite. The Prime focus camera design was thus adapted for use on either telescope, increasing the detector size to 92mmx92mm. Since the camera will be mounted on the Nasmyth port of the new telescope, it was dubbed WiNCam (Wide-field Nasmyth Camera). This paper describes both WiNCam and the new telescope. Producing an instrument that can be swapped between two very different telescopes poses some unique challenges. At the Nasmyth port of the alt-az telescope there is ample circumferential space, while on the 74 inch the available envelope is constrained by the optical footprint of the secondary, if further obscuration is to be avoided. This forces the design into a cylindrical volume of 600mm diameter x 250mm height. The back focal distance is tightly constrained on the new telescope, shoehorning the shutter, filter unit, guider mechanism, a 10mm thick window and a tip/tilt mechanism for the detector into 100mm depth. The iris shutter and filter wheel planned for prime focus could no longer be accommodated. Instead, a compact shutter with a thickness of less than 20mm has been designed in-house, using a sliding curtain mechanism to cover an aperture of 125mmx125mm, while the filter wheel has been replaced with 2 peripheral filter cartridges (6 filters each) and a gripper to move a filter into the beam. We intend using through-vacuum wall PCB technology across the cryostat vacuum interface, instead of traditional hermetic connector-based wiring. This

  8. Plastic particles in coastal pelagic ecosystems of the Northeast Pacific ocean.

    PubMed

    Doyle, Miriam J; Watson, William; Bowlin, Noelle M; Sheavly, Seba B

    2011-02-01

    The purpose of this study was to examine the distribution, abundance and characteristics of plastic particles in plankton samples collected routinely in Northeast Pacific ecosystems, and to contribute to the development of ideas for future research into the occurrence and impact of small plastic debris in marine pelagic ecosystems. Plastic debris particles were assessed from zooplankton samples collected as part of the National Oceanic and Atmospheric Administration's (NOAA) ongoing ecosystem surveys during two research cruises in the Southeast Bering Sea in the spring and fall of 2006 and four research cruises off the U.S. west coast (primarily off southern California) in spring, summer and fall of 2006, and in January of 2007. Nets with 0.505 mm mesh were used to collect surface samples during all cruises, and sub-surface samples during the four cruises off the west coast. The 595 plankton samples processed indicate that plastic particles are widely distributed in surface waters. The proportion of surface samples from each cruise that contained particles of plastic ranged from 8.75 to 84.0%, whereas particles were recorded in sub-surface samples from only one cruise (in 28.2% of the January 2007 samples). Spatial and temporal variability was apparent in the abundance and distribution of the plastic particles and mean standardized quantities varied among cruises with ranges of 0.004-0.19 particles/m³, and 0.014-0.209 mg dry mass/m³. Off southern California, quantities for the winter cruise were significantly higher, and for the spring cruise significantly lower than for the summer and fall surveys (surface data). Differences between surface particle concentrations and mass for the Bering Sea and California coast surveys were significant for pair-wise comparisons of the spring but not the fall cruises. The particles were assigned to three plastic product types: product fragments, fishing net and line fibers, and industrial pellets; and five size categories: <1 mm, 1-2.5 mm, >2.5-5 mm, >5-10 mm, and >10 mm. Product fragments accounted for the majority of the particles, and most were less than 2.5 mm in size. The ubiquity of such particles in the survey areas and predominance of sizes <2.5 mm implies persistence in these pelagic ecosystems as a result of continuous breakdown from larger plastic debris fragments, and widespread distribution by ocean currents. Detailed investigations of the trophic ecology of individual zooplankton species, and their encounter rates with various size ranges of plastic particles in the marine pelagic environment, are required in order to understand the potential for ingestion of such debris particles by these organisms. Ongoing plankton sampling programs by marine research institutes in large marine ecosystems are good potential sources of data for continued assessment of the abundance, distribution and potential impact of small plastic debris in productive coastal pelagic zones.

  9. A deformable phantom for 4D radiotherapy verification: Design and image registration evaluation

    SciTech Connect

    Serban, Monica; Heath, Emily; Stroian, Gabriela; Collins, D. Louis; Seuntjens, Jan

    2008-03-15

    Motion of thoracic tumors with respiration presents a challenge for three-dimensional (3D) conformal radiation therapy treatment. Validation of techniques aimed at measuring and minimizing the effects of respiratory motion requires a realistic deformable phantom for use as a gold standard. The purpose of this study was to develop and study the characteristics of a reproducible, tissue equivalent, deformable lung phantom. The phantom consists of a Lucite cylinder filled with water containing a latex balloon stuffed with dampened natural sponges. The balloon is attached to a piston that mimics the human diaphragm. Nylon wires and Lucite beads, emulating vascular and bronchial bifurcations, were uniformly glued at various locations throughout the sponges. The phantom is capable of simulating programmed irregular breathing patterns with varying periods and amplitudes. A tissue equivalent tumor, suitable for holding radiochromic film for dose measurements was embedded in the sponge. To assess phantom motion, eight 3D computed tomography data sets of the static phantom were acquired for eight equally spaced positions of the piston. The 3D trajectories of 12 manually chosen point landmarks and the tumor center-of-mass were studied. Motion reproducibility tests of the deformed phantom were established on seven repeat scans of three different states of compression. Deformable image registration (DIR) of the extreme breathing phases was performed. The accuracy of the DIR was evaluated by visual inspection of image overlays and quantified by the distance-to-agreement (DTA) of manually chosen point landmarks and triangulated surfaces obtained from 3D contoured structures. In initial tests of the phantom, a 20-mm excursion of the piston resulted in deformations of the balloon of 20 mm superior-inferior, 4 mm anterior-posterior, and 5 mm left-right. The change in the phantom mean lung density ranged from 0.24 (0.12 SD) g/cm{sup 3} at peak exhale to 0.19 (0.12 SD) g/cm{sup 3} at peak inhale. The SI displacement of the landmarks varied between 94% and 3% of the piston excursion for positions closer and farther away from the piston, respectively. The reproducibility of the phantom deformation was within the image resolution (0.7x0.7x1.25 mm{sup 3}). Vector average registration accuracy based on point landmarks was found to be 0.5 (0.4 SD) mm. The tumor and lung mean 3D DTA obtained from triangulated surfaces were 0.4 (0.1 SD) mm and 1.0 (0.8 SD) mm, respectively. This phantom is capable of reproducibly emulating the physically realistic lung features and deformations and has a wide range of potential applications, including four-dimensional (4D) imaging, evaluation of deformable registration accuracy, 4D planning and dose delivery.

  10. Growth of Megaspherulites In a Rhyolitic Vitrophyre

    NASA Technical Reports Server (NTRS)

    Smith, Robert K.; Tremallo, Robin L.; Lofgren, Gary E.

    2000-01-01

    Megaspherulites occur in the middle zone of a thick sequence of rhyolitic vitrophyre that occupies a small, late Eocene to early Oligocene volcanic-tectonic basin near Silver Cliff, Custer County, Colorado. Diameters of the megaspherulites range from 0.3 m to over 3.66 m, including a clay envelope. The megaspherulites are compound spherulites. consisting of an extremely large number (3.8 x 10(exp 9) to 9.9 x 10(exp 9)) of individual growth cones averaging 3 mm long by 1.25 mm wide at their termination. They are holocrystalline, very fine- to fine-grained, composed of disordered to ordered sanidine (orthoclase) and quartz, and surrounded by a thin K-feldspar, quartz rich rind, an inner clay layer with mordenite, and an outer clay layer composed wholly of 15 A montmorillonite. Whole rock analyses of the megaspherulites show a restricted composition from their core to their outer edge, with an average analyses of 76.3% SiO2, 0.34% CaO, 2.17% Na2O, 6.92% K2O, 0.83% H2O+ compared to the rhyolitic vitrophyre from which they crystallize with 71.07% SiO2, 0.57% CaO, 4.06% Na2O,4.l0% K2O, and 6.40% H2O+. The remaining oxides of Fe2O3 (total Fe), A12O3, MnO,MgO, TiO2, P2O5, Cr2O3, and trace elements show uniform distribution between the megaspherulites and the rhyolitic vitrophyre. Megaspherulite crystallization began soon after the rhyolitic lava ceased to flow as the result of sparse heterogeneous nucleation, under nonequilibrium conditions, due to a high degree of undercooling, delta T. The crystals grow with a fibrous habit which is favored by a large delta T ranging between 245 C and 295 C, despite lowered viscosity, and enhanced diffusion due to the high H2O content, ranging between 5% and 7%. Therefore, megaspherulite growth proceeded in a diffusion controlled manner, where the diffusion, rate lags behind the crystal growth rate at the crystal-liquid interface, restricting fibril lengths and diameters to the 10 micron to 15 micron and 3 micron and 8 micron ranges respectively. Once diffusion reestablishes itself at the crystallization front, a new nucleation event occurs at the terminated tips of the fibril cones and a new cone begins to develop with a similar orientation (small angle branching) to the earlier cones. During crystallization, these fibril cones impinge upon each other, resulting in fibril cone-free areas. These cone-free areas consist of coarser, fine-grained phases, dominated by quartz, which crystallized from the melt as it accumulated between the crystallizing K-feldspar fibrils of the cones. The anhydrous nature of the disordered to ordered sanidine (orthoclase) and quartz, suggests that water in the vitrophyre moved ahead of the crystallization front, resulting in a water rich fluid being enriched in Si, K, Na, Mg, Ca, Sr, Ba, and Y. The clay layers associated with the megaspherulites are therefore, the result of the deuteric alteration between the fractionated water and the vitrophyre, as indicated by the presence of the minerals mordenite and montmorillonite. This silica rich fluid also resulted in the total silicification of the megaspherulites within the upper 3 m of the vitrophyre.

  11. The aggregation efficiency of very fine volcanic ash

    NASA Astrophysics Data System (ADS)

    Del Bello, E.; Taddeucci, J.; Scarlato, P.

    2013-12-01

    Explosive volcanic eruptions can discharge large amounts of very small sized pyroclasts (under 0.090 mm) into the atmosphere that may cause problems to people, infrastructures and environment. The transport and deposition of fine ash are ruled by aggregation that causes premature settling of fine ash and, as consequence, significantly reduces the concentration of airborne material over long distances. Parameterizing the aggregation potential of fine ash is then needed to provide accurate modelling of ash transport and deposition from volcanic plumes. Here we present the first results of laboratory experiments investigating the aggregation efficiency of very fine volcanic particles. Previous laboratory experiments have shown that collision kinetic and relative humidity provide the strongest effect on aggregation behaviour but were only limited to particles with size > 0.125 mm. In our work, we focus on natural volcanic ash at ambient humidity with particles size < 0.090 mm, by taking into account the effect of grain size distribution on aggregation potential. Two types of ash were used in our experiments: fresh ash, collected during fall-out from a recent plume-forming eruption at Sakurajima (Japan -July 2013) and old ash, collected from fall-out tephra deposits at Campi Flegrei (Italy, ca. 10 ka), to account for the different chemical composition and morphoscopic effects of altered ash on aggregation efficiency. Total samples were hand sieved to obtain three classes with unimodal grain size distributions (<0.090 mm, <0.063 mm, <0.032 mm). Bimodal grain size distributions were also obtained by mixing the three classes in different proportions. During each experiments, particles were sieved from the top of a transparent tank where a fan, placed at the bottom, allows turbulent dispersion of particles. Collision and sticking of particles on a vertical glass slide were filmed with a high speed cameras at 6000 fps. Our lenses arrangement provide high image resolution

  12. The LITA Drill and Sample Delivery System

    NASA Astrophysics Data System (ADS)

    Paulsen, G.; Yoon, S.; Zacny, K.; Wettergreeng, D.; Cabrol, N. A.

    2013-12-01

    The Life in the Atacama (LITA) project has a goal of demonstrating autonomous roving, sample acquisition, delivery and analysis operations in Atacama, Chile. To enable the sample handling requirement, Honeybee Robotics developed a rover-deployed, rotary-percussive, autonomous drill, called the LITA Drill, capable of penetrating to ~80 cm in various formations, capturing and delivering subsurface samples to a 20 cup carousel. The carousel has a built-in capability to press the samples within each cup, and position target cups underneath instruments for analysis. The drill and sample delivery system had to have mass and power requirements consistent with a flight system. The drill weighs 12 kg and uses less than 100 watt of power to penetrate ~80 cm. The LITA Drill auger has been designed with two distinct stages. The lower part has deep and gently sloping flutes for retaining powdered sample, while the upper section has shallow and steep flutes for preventing borehole collapse and for efficient movement of cuttings and fall back material out of the hole. The drill uses the so called 'bite-sampling' approach that is samples are taken in short, 5-10 cm bites. To take the first bite, the drill is lowered onto the ground and upon drilling of the first bite it is then retracted into an auger tube. The auger with the auger tube are then lifted off the ground and positioned next to the carousel. To deposit the sample, the auger is rotated and retracted above the auger tube. The cuttings retained on the flutes are either gravity fed or are brushed off by a passive side brush into the cup. After the sample from the first bite has been deposited, the drill is lowered back into the same hole to take the next bite. This process is repeated until a target depth is reached. The bite sampling is analogous to peck drilling in the machining process where a bit is periodically retracted to clear chips. If there is some fall back into the hole once the auger has cleared the hole, this fall back material will be augered out during auger re-insertion. The next bite will be taken only once the auger has reached the true bottom. In the bite sampling approach the stratigraphy is somewhat preserved since every time the sample is taken, it more or less represents the depth interval in the hole. There is going to be some level of cross contamination due to smearing of cuttings on the flutes against the borehole as the auger is being pulled out, or when formation is very porous and unstable. The goal of the first drill campaign in Atacama in May of 2012 was to demonstrate successful operation of the bite sampling method and to learn about diversity of soils and rocks in the Atacama. In 2013, the sampling system has been integrated onto the CMU Zoe rover and autonomously deployed in Atacama. The drill penetrated various formations and delivered samples to a carousel. When soil was very porous, poor sample recovery was observed. When the soil was dense and cohesive, sample recovery was 100% with little cross contamination. To enable greater sample recovery in loose and unstable formations, the auger diameter will be increased from the current 12.5 mm to 19 mm. Acknowledgements: The project has been funded by the NASA ASTEP program.

  13. A deformable phantom for 4D radiotherapy verification: design and image registration evaluation.

    PubMed

    Serban, Monica; Heath, Emily; Stroian, Gabriela; Collins, D Louis; Seuntjens, Jan

    2008-03-01

    Motion of thoracic tumors with respiration presents a challenge for three-dimensional (3D) conformal radiation therapy treatment. Validation of techniques aimed at measuring and minimizing the effects of respiratory motion requires a realistic deformable phantom for use as a gold standard. The purpose of this study was to develop and study the characteristics of a reproducible, tissue equivalent, deformable lung phantom. The phantom consists of a Lucite cylinder filled with water containing a latex balloon stuffed with dampened natural sponges. The balloon is attached to a piston that mimics the human diaphragm. Nylon wires and Lucite beads, emulating vascular and bronchial bifurcations, were uniformly glued at various locations throughout the sponges. The phantom is capable of simulating programmed irregular breathing patterns with varying periods and amplitudes. A tissue equivalent tumor, suitable for holding radiochromic film for dose measurements was embedded in the sponge. To assess phantom motion, eight 3D computed tomography data sets of the static phantom were acquired for eight equally spaced positions of the piston. The 3D trajectories of 12 manually chosen point landmarks and the tumor center-of-mass were studied. Motion reproducibility tests of the deformed phantom were established on seven repeat scans of three different states of compression. Deformable image registration (DIR) of the extreme breathing phases was performed. The accuracy of the DIR was evaluated by visual inspection of image overlays and quantified by the distance-to-agreement (DTA) of manually chosen point landmarks and triangulated surfaces obtained from 3D contoured structures. In initial tests of the phantom, a 20-mm excursion of the piston resulted in deformations of the balloon of 20 mm superior-inferior, 4 mm anterior-posterior, and 5 mm left-right. The change in the phantom mean lung density ranged from 0.24 (0.12 SD) g/cm3 at peak exhale to 0.19 (0.12 SD) g/cm3 at peak inhale. The SI displacement of the landmarks varied between 94% and 3% of the piston excursion for positions closer and farther away from the piston, respectively. The reproducibility of the phantom deformation was within the image resolution (0.7 x 0.7 x 1.25 mm3). Vector average registration accuracy based on point landmarks was found to be 0.5 (0.4 SD) mm. The tumor and lung mean 3D DTA obtained from triangulated surfaces were 0.4 (0.1 SD) mm and 1.0 (0.8 SD) mm, respectively. This phantom is capable of reproducibly emulating the physically realistic lung features and deformations and has a wide range of potential applications, including four-dimensional (4D) imaging, evaluation of deformable registration accuracy, 4D planning and dose delivery.

  14. Optic neuropathy and increased retinal glial fibrillary acidic protein due to microbead-induced ocular hypertension in the rabbit

    PubMed Central

    Zhao, Jun; Zhu, Tian-Hui; Chen, Wen-Chieh; Peng, Shi-Ming; Huang, Xiao-Sheng; Cho, Kin-Sang; Chen, Dong Feng; Liu, Guei-Sheung

    2016-01-01

    AIM To characterize whether a glaucoma model with chronic elevation of the intraocular pressure (IOP) was able to be induced by anterior chamber injection of microbeads in rabbits. METHODS In order to screen the optimal dose of microbead injection, IOP was measured every 3d for 4wk using handheld applanation tonometer after a single intracameral injection of 10 µL, 25 µL, 50 µL or 100 µL microbeads (5×106 beads/mL; n=6/group) in New Zealand White rabbits. To prolong IOP elevation, two intracameral injections of 50 µL microbeads or phosphate buffer saline (PBS) were made respectively at days 0 and 21 (n=24/group). The fellow eye was not treated. At 5wk after the second injection of microbeads or PBS, bright-field microscopy and transmission electron microscopy (TEM) were used to assess the changes in the retina. The expression of glial fibrillary acidic protein (GFAP) in the retina was evaluated by immunofluorescence, quantitative real-time polymerase chain reaction and Western blot at 5wk after the second injection of microbeads. RESULTS Following a single intracameral injection of 10 µL, 25 µL, 50 µL or 100 µL microbead, IOP levels showed a gradual increase and a later decrease over a 4wk period after a single injection of microbead into the anterior chamber of rabbits. A peak IOP was observed at day 15 after injection. No significant difference in peak value of IOP was found between 10 µL and 25 µL groups (17.13±1.25 mm Hg vs 17.63±0.74 mm Hg; P=0.346). The peak value of IOP from 50 µL group (23.25±1.16 mm Hg) was significantly higher than 10 µL and 25 µL groups (all P<0.05). Administration of 100 µL microbead solution (23.00±0.93 mm Hg) did not lead to a significant increase in IOP compared to the 50 µL group (P=0.64). A prolonged elevated IOP duration up to 8wk was achieved by administering two injections of 50 µL microbeads (20.48±1.21 mm Hg vs 13.60±0.90 mm Hg in PBS-injected group; P<0.05). The bright-field and TEM were used to assess the changes of retinal ganglion cells (RGCs). Compared with PBS-injected group, the extended IOP elevation was associated with the degeneration of optic nerve, the reduction of RGC axons (47.16%, P<0.05) and the increased GFAP expression in the retina (4.74±1.10 vs 1.00±0.46, P<0.05). CONCLUSION Two injections of microbeads into the ocular anterior chamber of rabbits lead to a prolonged IOP elevation which results in structural abnormality as well as loss in RGCs and their axons without observable ocular structural damage or inflammatory response. We have therefore established a novel and practical model of experimental glaucoma in rabbits. PMID:28003971

  15. WISDOM: the WIYN spectrograph for Doppler monitoring: a NASA-NSF concept for an extreme precision radial velocity instrument in support of TESS

    NASA Astrophysics Data System (ADS)

    Fżrész, Gábor; Simcoe, Robert; Barnes, Stuart I.; Buchhave, Lars A.; Egan, Mark; Foster, Rick; Hellickson, Tim; Malonis, Andrew; Phillips, David; Shectman, Stephen; Walsworth, Ronald; Winn, Josh; Woods, Deborah

    2016-08-01

    The Kepler mission highlighted that precision radial velocity (PRV) follow-up is a real bottleneck in supporting transiting exoplanet surveys. The limited availability of PRV instruments, and the desire to break the "1 m/s" precision barrier, prompted the formation of a NASA-NSF collaboration `NN-EXPLORE' to call for proposals designing a new Extreme Precision Doppler Spectrograph (EPDS). By securing a significant fraction of telescope time on the 3.5m WIYN at Kitt Peak, and aiming for unprecedented long-term precision, the EPDS instrument will provide a unique tool for U.S. astronomers in characterizing exoplanet candidates identified by TESS. One of the two funded instrument concept studies is led by the Massachusetts Institute of Technology, in consortium with Lincoln Laboratories, Harvard-Smithsonian Center for Astrophysics and the Carnegie Observatories. This paper describes the instrument concept WISDOM (WIYN Spectrograph for DOppler Monitoring) prepared by this team. WISDOM is a fiber fed, environmentally controlled, high resolution (R=110k), asymmetric white-pupil echelle spectrograph, covering a wide 380-1300nm wavelength region. Its R4 and R6 echelle gratings provide the main dispersion, symmetrically mounted on either side of a vertically aligned, vacuum-enclosed carbon fiber optical bench. Each grating feeds two cameras and thus the resulting wavelength range per camera is narrow enough that the VPHG cross-dispersers and employed anti-reflection coatings are highly efficient. The instrument operates near room temperature, and so thermal background for the near-infrared arm is mitigated by thermal blocking filters and a short (1.7μm) cutoff HgCdTe detector. To achieve high resolution while maintaining small overall instrument size (100/125mm beam diameter), imposed by the limited available space within the observatory building, we chose to slice the telescope pupil 6 ways before coupling light into fibers. An atmospheric dispersion corrector and fast

  16. Understanding catchment scale sediment sources using geochemical tracers

    NASA Astrophysics Data System (ADS)

    Ferreira, Carla S. S.; Walsh, Rory P. D.; Shakesby, Richard A.; Steenhuis, Tammo S.; Ferreira, António J. D.; Coelho, Celeste O. A.

    2013-04-01

    It is well-established that urbanization leads to increased erosion (at least locally) as well as enhanced overland flow and streamflow peaks. Less is known about how the spatial distribution of erosion sources and scale of increases in erosion vary with the nature of urbanization in different climatic and socio-economic settings. This is important in order to prevent or reduce adverse impacts of erosion on downstream sedimentation, channel siltation and shifting, and river pollution. This paper adopts a sediment fingerprinting approach to assess the impact of partial urbanization and associated land-use change on sediment sources within a peri-urban catchment (6 km2), Ribeira dos Covões on the outskirts of the city of Coimbra in central Portugal. Urban land-use has increased from just 6% in 1958 to 30% in 2009. The urban pattern includes some well-defined urban residential centres, but also areas of discontinuous urban sprawl, including educational, health and small industrial facilities, numerous new roads and an enterprise park is under construction on the upper part of the catchment. The catchment has a wet Mediterranean climate and the lithology comprises sandstone in the west and limestone in the east. Soil depth is generally >40cm. The average slope angle is 8° (maximum 47°). Altitude ranges from 30m to 205m. A sediment fingerprinting approach was adopted to help establish the relative importance of sediment inputs from different urban areas. During September 2012 current bed-sediment samples (0-3 cm depth) were collected from 11 channel sites along the main stream and in different tributaries. At sites where bed-sediment was deeper, additional samples were taken at 3cm intervals to a maximum depth of around 42cm. In addition, overbank sediment samples (0-3cm depth) were collected at 11 locations around the catchment. All samples were oven-dried (at 38°C) and different particle size fractions (0.125-2mm, 0.063-0.125mm and <0.063mm) obtained, where the <0

  17. Automatic tracking of arbitrarily shaped implanted markers in kilovoltage projection images: A feasibility study

    PubMed Central

    Regmi, Rajesh; Lovelock, D. Michael; Hunt, Margie; Zhang, Pengpeng; Pham, Hai; Xiong, Jianping; Yorke, Ellen D.; Goodman, Karyn A.; Rimner, Andreas; Mostafavi, Hassan; Mageras, Gig S.

    2014-01-01

    Purpose: Certain types of commonly used fiducial markers take on irregular shapes upon implantation in soft tissue. This poses a challenge for methods that assume a predefined shape of markers when automatically tracking such markers in kilovoltage (kV) radiographs. The authors have developed a method of automatically tracking regularly and irregularly shaped markers using kV projection images and assessed its potential for detecting intrafractional target motion during rotational treatment. Methods: Template-based matching used a normalized cross-correlation with simplex minimization. Templates were created from computed tomography (CT) images for phantom studies and from end-expiration breath-hold planning CT for patient studies. The kV images were processed using a Sobel filter to enhance marker visibility. To correct for changes in intermarker relative positions between simulation and treatment that can introduce errors in automatic matching, marker offsets in three dimensions were manually determined from an approximately orthogonal pair of kV images. Two studies in anthropomorphic phantom were carried out, one using a gold cylindrical marker representing regular shape, another using a Visicoil marker representing irregular shape. Automatic matching of templates to cone beam CT (CBCT) projection images was performed to known marker positions in phantom. In patient data, automatic matching was compared to manual matching as an approximate ground truth. Positional discrepancy between automatic and manual matching of less than 2 mm was assumed as the criterion for successful tracking. Tracking success rates were examined in kV projection images from 22 CBCT scans of four pancreas, six gastroesophageal junction, and one lung cancer patients. Each patient had at least one irregularly shaped radiopaque marker implanted in or near the tumor. In addition, automatic tracking was tested in intrafraction kV images of three lung cancer patients with irregularly shaped markers during 11 volumetric modulated arc treatments. Purpose-built software developed at our institution was used to create marker templates and track the markers embedded in kV images. Results: Phantom studies showed mean ± standard deviation measurement uncertainty of automatic registration to be 0.14 ± 0.07 mm and 0.17 ± 0.08 mm for Visicoil and gold cylindrical markers, respectively. The mean success rate of automatic tracking with CBCT projections (11 frames per second, fps) of pancreas, gastroesophageal junction, and lung cancer patients was 100%, 99.1% (range 98%–100%), and 100%, respectively. With intrafraction images (approx. 0.2 fps) of lung cancer patients, the success rate was 98.2% (range 97%–100%), and 94.3% (range 93%–97%) using templates from 1.25 mm and 2.5 mm slice spacing CT scans, respectively. Correction of intermarker relative position was found to improve the success rate in two out of eight patients analyzed. Conclusions: The proposed method can track arbitrary marker shapes in kV images using templates generated from a breath-hold CT acquired at simulation. The studies indicate its feasibility for tracking tumor motion during rotational treatment. Investigation of the causes of misregistration suggests that its rate of incidence can be reduced with higher frequency of image acquisition, templates made from smaller CT slice spacing, and correction of changes in intermarker relative positions when they occur. PMID:24989384

  18. Quantifying moisture transport in cementitious materials using neutron radiography

    NASA Astrophysics Data System (ADS)

    Lucero, Catherine L.

    A portion of the concrete pavements in the US have recently been observed to have premature joint deterioration. This damage is caused in part by the ingress of fluids, like water, salt water, or deicing salts. The ingress of these fluids can damage concrete when they freeze and expand or can react with the cementitious matrix causing damage. To determine the quality of concrete for assessing potential service life it is often necessary to measure the rate of fluid ingress, or sorptivity. Neutron imaging is a powerful method for quantifying fluid penetration since it can describe where water has penetrated, how quickly it has penetrated and the volume of water in the concrete or mortar. Neutrons are sensitive to light atoms such as hydrogen and thus clearly detect water at high spatial and temporal resolution. It can be used to detect small changes in moisture content and is ideal for monitoring wetting and drying in mortar exposed to various fluids. This study aimed at developing a method to accurately estimate moisture content in mortar. The common practice is to image the material dry as a reference before exposing to fluid and normalizing subsequent images to the reference. The volume of water can then be computed using the Beer-Lambert law. This method can be limiting because it requires exact image alignment between the reference image and all subsequent images. A model of neutron attenuation in a multi-phase cementitious composite was developed to be used in cases where a reference image is not available. The attenuation coefficients for water, un-hydrated cement, and sand were directly calculated from the neutron images. The attenuation coefficient for the hydration products was then back-calculated. The model can estimate the degree of saturation in a mortar with known mixture proportions without using a reference image for calculation. Absorption in mortars exposed to various fluids (i.e., deionized water and calcium chloride solutions) were investigated. It has been found through this study that small pores, namely voids created by chemical shrinkage, gel pores, and capillary pores, ranging from 0.5 nm to 50 microm, fill quickly through capillary action. However, large entrapped and entrained air voids ranging from 0.05 to 1.25 mm remain empty during the initial filling process. In mortar exposed to calcium chloride solution, a decrease in sorptivity was observed due to an increase in viscosity and surface tension of the solution as proposed by Spragg et al 2011. This work however also noted a decrease in the rate of absorption due to a reaction between the salt and matrix which results in the filling of the pores in the concrete. The results from neutron imaging can help in the interpretation of standard absorption tests. ASTM C1585 test results can be further analyzed in several ways that could give an accurate indication of the durability of the concrete. Results can be reported in depth of penetration versus the square root of time rather than mm3 of fluid per mm2 of exposed surface area. Since a known fraction of pores are initially filling before reaching the edge of the sample, the actual depth of penetration can be calculated. This work is compared with an 'intrinsic sorptivity' that can be used to interpret mass measurements. Furthermore, the influence of shrinkage reducing admixtures (SRAs) on drying was studied. Neutron radiographs showed that systems saturated in water remain "wetter" than systems saturated in 5% SRA solution. The SRA in the system reduces the moisture diffusion coefficient due an increase in viscosity and decrease in surface tension. Neutron radiography provided spatial information of the drying front that cannot be achieved using other methods.

  19. Understanding sediment sources in a peri-urban Mediterranean catchment using geochemical tracers

    NASA Astrophysics Data System (ADS)

    Ferreira, Carla; Walsh, Rory; Kikuchi, Ryunosuke; Blake, Will

    2016-04-01

    different particle size fractions (0.125-2.000mm, 0.063-0.125mm and <0.063mm). Seventeen stream sites were sampled plus a sample of sediment from a road surface immediately it entered the stream network. The elemental composition (40 elements) of each size fraction was assessed using a Niton X-ray fluorescence elemental analyser. Results show that rock type has a profound influence on the geochemical properties of bed-sediments. Catchment outlet sediment collected after the summer and a storm of high rainfall intensity following dry weather displayed geochemical properties closer to those of sediment from sandstone sub-catchments, and in particularly sediment from the enterprise park under construction. After the storm that followed very wet weather, however, limestone areas became of much greater significance as sediment sources, probably because of the high soil saturation. At limestone stream sites receiving runoff from the newly constructed road, fine bed-sediment geochemistry was found to be similar to that of road sediment, indicating a high contribution of this source. These results are supported by spatio-temporal differences in streamflow and suspended sediment concentrations at instrumented monitoring stations. It is concluded that this methodology represents a potentially useful tool to enable river managers to detect and assess sediment sources in urbanized and partly urbanized catchments, and to supporting them in designing and implementing effective land-use mosaics and site-specific measures to mitigate erosion.

  20. Geo-PET: A novel generic organ-pet for small animal organs and tissues

    NASA Astrophysics Data System (ADS)

    Sensoy, Levent

    Reconstructed tomographic image resolution of small animal PET imaging systems is improving with advances in radiation detector development. However the trend towards higher resolution systems has come with an increase in price and system complexity. Recent developments in the area of solid-state photomultiplication devices like silicon photomultiplier arrays (SPMA) are creating opportunities for new high performance tools for PET scanner design. Imaging of excised small animal organs and tissues has been used as part of post-mortem studies in order to gain detailed, high-resolution anatomical information on sacrificed animals. However, this kind of ex-vivo specimen imaging has largely been limited to ultra-high resolution muCT. The inherent limitations to PET resolution have, to date, excluded PET imaging from these ex-vivo imaging studies. In this work, we leverage the diminishing physical size of current generation SPMA designs to create a very small, simple, and high-resolution prototype detector system targeting ex-vivo tomographic imaging of small animal organs and tissues. We investigate sensitivity, spatial resolution, and the reconstructed image quality of a prototype small animal PET scanner designed specifically for imaging of excised murine tissue and organs. We aim to demonstrate that a cost-effective silicon photomultiplier (SiPM) array based design with thin crystals (2 mm) to minimize depth of interaction errors might be able to achieve sub-millimeter resolution. We hypothesize that the substantial decrease in sensitivity associated with the thin crystals can be compensated for with increased solid angle detection, longer acquisitions, higher activity and wider acceptance energy windows (due to minimal scatter from excised organs). The constructed system has a functional field of view (FoV) of 40 mm diameter, which is adequate for most small animal specimen studies. We perform both analytical (3D-FBP) and iterative (ML-EM) methods in order to reconstruct tomographic images. Results demonstrate good agreement between the simulation and the prototype. Our detector system with pixelated crystals is able to separate small objects as close as 1.25 mm apart, whereas spatial resolution converges to the theoretical limit of 1.6 mm (half the size of the smallest detecting element), which is to comparable to the spatial resolution of the existing commercial small animal PET systems. Better system spatial resolution is achievable with new generation SiPM detector boards with 1 mm x 1 mm cell dimensions. We demonstrate through Monte Carlo simulations that it is possible to achieve sub-millimeter spatial image resolution (0.7 mm for our scanner) in complex objects using monolithic crystals and exploiting the light-sharing mechanism among the neighboring detector cells. Results also suggest that scanner (or object) rotation minimizes artifacts arising from poor angular sampling, which is even more significant in smaller PET designs as the gaps between the sensitive regions of the detector have a more exaggerated effect on the overall reconstructed image quality when the design is more compact. Sensitivity of the system, on the other hand, can be doubled by adding two additional detector heads resulting in a, fully closed, 4? geometry.

  1. Sex-structure, depth distribution, intermoult period and reproductive pattern of the deep-sea red crab Chaceon affinis (Brachyura, Geryonidae) in two populations in the north-eastern Atlantic

    NASA Astrophysics Data System (ADS)

    Biscoito, Manuel; Freitas, Mafalda; Pajuelo, José G.; Triay-Portella, Raül; Santana, José I.; Costa, Ana L.; Delgado, João; González, José A.

    2015-01-01

    This work investigated the biology of Chaceon affinis in two isolated populations of the Atlantic Ocean, including depth distribution, sexual structure, reproductive patterns and intermoult period. Males were larger and heavier than females. Mean size decreased with depth for both males and females. The highest abundance was found at 600-799 m of depth for males and at 800-999 m depth stratum for females. The highest abundance of ovigerous females was found at the 800-999 m depth stratum. Of the different ovaries' colour or colour shades recorded, only six categories were histologically characterized. The presence of spermatophores in the spermatheca of females in carapace stages II and III suggests that spermatophores are viable and used during the intermoult period. The size at sexual maturity in females was estimated at 104.4-104.7 mm carapace width (CW) in Madeira, and 109.3-110.5 mm CW in the Canary Islands. Only three categories of testes were identified. Mature testes consisted in a large mass, with highly coiled vasa deferentia visible to the naked eye. The size at sexual maturity in males was estimated at 113.8 mm CW in Madeira and 118.9 mm CW in the Canaries. The relative growth of males showed significant changes along the ontogeny and size at which allometric growth changes, as an indicator of morphometric maturity, occurred between 103.2 and 103.6 mm CW in Madeira and between 111.4 and 113.1 mm CW in the Canaries. In females, size at which allometric growth changes was found for maximum width of fifth abdominal somite (AS5W) at 98.2 mm CW in Madeira and 103.0 mm CW in the Canaries. The size at maturity obtained for C. affinis indicates that the minimum landing size (MLS) should not be set smaller than 125 mm CW in Madeira and 130 mm CW in the Canaries. This conservative MLS, higher than length at functional maturity, would safeguard immature individuals until they reach the size at which they can contribute to the reproductive capacity of the

  2. Modeling a Hypothetical {sup 170}Tm Source for Brachytherapy Applications

    SciTech Connect

    Enger, Shirin A.; D'Amours, Michel; Beaulieu, Luc

    2011-10-15

    Purpose: To perform absorbed dose calculations based on Monte Carlo simulations for a hypothetical {sup 170}Tm source and to investigate the influence of encapsulating material on the energy spectrum of the emitted electrons and photons. Methods: GEANT4 Monte Carlo code version 9.2 patch 2 was used to simulate the decay process of {sup 170}Tm and to calculate the absorbed dose distribution using the GEANT4 Penelope physics models. A hypothetical {sup 170}Tm source based on the Flexisource brachytherapy design with the active core set as a pure thulium cylinder (length 3.5 mm and diameter 0.6 mm) and different cylindrical source encapsulations (length 5 mm and thickness 0.125 mm) constructed of titanium, stainless-steel, gold, or platinum were simulated. The radial dose function for the line source approximation was calculated following the TG-43U1 formalism for the stainless-steel encapsulation. Results: For the titanium and stainless-steel encapsulation, 94% of the total bremsstrahlung is produced inside the core, 4.8 and 5.5% in titanium and stainless-steel capsules, respectively, and less than 1% in water. For the gold capsule, 85% is produced inside the core, 14.2% inside the gold capsule, and a negligible amount (<1%) in water. Platinum encapsulation resulted in bremsstrahlung effects similar to those with the gold encapsulation. The range of the beta particles decreases by 1.1 mm with the stainless-steel encapsulation compared to the bare source but the tissue will still receive dose from the beta particles several millimeters from the source capsule. The gold and platinum capsules not only absorb most of the electrons but also attenuate low energy photons. The mean energy of the photons escaping the core and the stainless-steel capsule is 113 keV while for the gold and platinum the mean energy is 160 keV and 165 keV, respectively. Conclusions: A {sup 170}Tm source is primarily a bremsstrahlung source, with the majority of bremsstrahlung photons being

  3. SU-E-T-450: Dosimetric Impact of Rotational Error On Multiple-Target Intensity-Modulated Radiosurgery (IMRS) with Single-Isocenter

    SciTech Connect

    Jang, S; Huq, M

    2014-06-01

    Purpose: Evaluating the dosimetric-impact on multiple-targets placed away from the isocenter-target with varying rotational-error introduced by initial setup uncertainty and/or intrafractional-movement Methods: CyberKnife-Phantom was scanned with the Intracranial SRS-protocol of 1.25mm slice-thickness and the multiple-targets(GTV) of 1mm and 10mm in diameter were contoured on the Eclipse. PTV for distal-target only was drawn with 1mm expansion around the GTV to find out how much margin is needed to compensate for the rotational-error. The separation between the isocenter-target and distal-target was varied from 3cm to 7cm. RapidArc-based IMRS plans of 16Gy single-fraction were generated with five non-coplanar arcs by using Varian TrueBeam-STx equipped with high resolution MLC leaves of 2.5mm at center and with dose-rate of 1400MU/min at 6MV for flatteringfilter- free(FFF). An identical CT image with intentionally introduced 1° rotational-error was registered with the planning CT image, and the isodose distribution and Dose-Volume-Histogram(DVH) were compared with the original plans. Additionally, the dosimetric-impact of rotational error was evaluated with that of 6X photon energy which was generated with the same target-coverage. Results: For the 1mm-target with 6X-FFF, PTV-coverage(D100) of the distal-target with 1° rotational-error decreased from 1.00 to 0.35 as the separation between isocenter-target and distal-target increased from 3cm to 7cm. However, GTV-coverage(D100) was 1.0 except that of 7cm-separation(0.55), which resulted from the 1mm-margin around the distal-target. For 6X photon, GTV-coverage remained at 1.0 regardless of the separation of targets, showing that the dosimetric-impact of rotational error depends on the degree of rotational-error, separation of targets, and dose distribution around targets. For 10mm-target, PTV-coverage of distaltarget located 3cm-away was better than that of 1mm-target(0.93 versus 0.7) and GTV-coverage was 1.0 regardless of 6X-FFF/6X photon beams. Conclusion: RapidArc-based Multiple-target IMRS may Resultin a compromised outcome due to the setup-error for distal-targets. With 1mm-margin, GTV-coverage of distal-target was 1.0 although the separation of targets was up to 5cm.

  4. Assessment of individual organ doses in a realistic human phantom from neutron and gamma stimulated spectroscopy of the breast and liver

    PubMed Central

    Belley, Matthew D.; Segars, William Paul; Kapadia, Anuj J.

    2014-01-01

    Purpose: Understanding the radiation dose to a patient is essential when considering the use of an ionizing diagnostic imaging test for clinical diagnosis and screening. Using Monte Carlo simulations, the authors estimated the three-dimensional organ-dose distribution from neutron and gamma irradiation of the male liver, female liver, and female breasts for neutron- and gamma-stimulated spectroscopic imaging. Methods: Monte Carlo simulations were developed using the Geant4 GATE application and a voxelized XCAT human phantom. A male and a female whole body XCAT phantom was voxelized into 256 × 256 × 600 voxels (3.125 × 3.125 × 3.125 mm3). A monoenergetic rectangular beam of 5.0 MeV neutrons or 7.0 MeV photons was made incident on a 2 cm thick slice of the phantom. The beam was rotated at eight different angles around the phantom ranging from 0° to 180°. Absorbed dose was calculated for each individual organ in the body and dose volume histograms were computed to analyze the absolute and relative doses in each organ. Results: The neutron irradiations of the liver showed the highest organ dose absorption in the liver, with appreciably lower doses in other proximal organs. The dose distribution within the irradiated slice exhibited substantial attenuation with increasing depth along the beam path, attenuating to ∼15% of the maximum value at the beam exit side. The gamma irradiation of the liver imparted the highest organ dose to the stomach wall. The dose distribution from the gammas showed a region of dose buildup at the beam entrance, followed by a relatively uniform dose distribution to all of the deep tissue structures, attenuating to ∼75% of the maximum value at the beam exit side. For the breast scans, both the neutron and gamma irradiation registered maximum organ doses in the breasts, with all other organs receiving less than 1% of the breast dose. Effective doses ranged from 0.22 to 0.37 mSv for the neutron scans and 41 to 66 mSv for the gamma scans

  5. Nucleation and growth of rolling contact failure of 440C bearing steel

    NASA Technical Reports Server (NTRS)

    Gupta, V.; Bastias, P. C.; Hahn, G. T.; Rubin, C. A.

    1992-01-01

    A 'two-body' elasto-plastic finite element model of 2-dimensional rolling and rolling-plus-sliding was developed to treat the effect of surface irregularities. The model consists of a smooth cylinder in contact with a semi-infinite half-space that is either smooth or fitted with one of 0.4 microns deep or 7 microns deep groove, or a 0.4 microns high ridge-like asperity. The model incorporates elastic-linear-kinematic hardening-plastic (ELKP) and non-linear-kinematic hardening-plastic (NLKP) material constitutive relations appropriate for hardened bearing steel and the 440C grade. The calculated contact pressure distribution is Hertzian for smooth body contact, and it displays intense, stationary, pressure spikes superposed on the Hertzian pressure for contact with the grooved and ridged surface. The results obtained for the 0.4 microns deep groove compare well with those reported by Elsharkawy and Hamrock for an EHD lubricated contact. The effect of translating the counterface on the half space as opposed to indenting the half space with the counter face with no translation is studied. The stress and strain values near the surface are found to be similar for the two cases, whereas they are significantly different in the subsurface. It is seen that when tiny shoulders are introduced at the edge of the groove in the finite element model, the incremental plasticity and residual stresses are significantly higher in the vicinity of the right shoulder (rolling direction is from left to right) than at the left shoulder. This may explain the experimental observation that the spall nucleation occurs at the exit end of the artificially planted indents. Pure rolling calculations are compared with rolling + sliding calculations. For a coefficient of friction, mu = 0.1, the effect of friction is found to be small. Efforts were made to identify the material constitutive relations which best describe the deformation characteristics of the bearing steels in the initial few cycles. Elastic-linear-kinematic hardening-plastic (ELKP) material constitutive relations produce less net plastic deformation in the initial stages for a given stress, than seen in experiments. A new set of constitutive relations: non-linear-kinematic hardening-plastic (NLKP) was used. This material model produces more plasticity than the ELKP model and shows promise for treating the net distortions in the early stages. Techniques for performing experimental measurements that can be compared with the finite element calculations were devised. The measurements are being performed on 9mm-diameter, 440C steel cylindrical rolling elements in contact with 12.5 mm-diameter, 52100 steel balls in a 3-ball-rod fatigue test machine operating at 3600 RPM. Artificial, 7 microns deep, indents were inserted on the running track of the cylindrical rolling elements and profilometer measurements of these indents made, before and after the rolling. These preliminary measurements show that the indents are substantially deformed plastically in the process of rolling. The deformations of the groove calculated with the finite element model are comparable to those measured experimentally.

  6. Energy balance and canopy conductance of a boreal aspen forest: Partitioning overstory and understory components

    NASA Astrophysics Data System (ADS)

    Blanken, P. D.; Black, T. A.; Yang, P. C.; Neumann, H. H.; Nesic, Z.; Staebler, R.; den Hartog, G.; Novak, M. D.; Lee, X.

    1997-12-01

    The energy balance components were measured throughout most of 1994 in and above a southern boreal aspen (Populus tremuloides Michx.) forest (53.629°N 106.200°W) with a hazelnut (Corylus cornuta Marsh.) understory as part of the Boreal Ecosystem-Atmosphere Study. The turbulent fluxes were measured at both levels using the eddy-covariance technique. After rejection of suspect data due to instationarity or inhomogeneity, occasional erratic behavior in turbulent fluxes and lack of energy balance closure led to a recalculation of the fluxes of sensible and latent heat using their ratio and the available energy. The seasonal development in leaf area was reflected in a strong seasonal pattern of the energy balance. Leaf growth began during the third week of May with a maximum forest leaf area index of 5.6 m2 m-2 reached by mid-July. During the full-leaf period, aspen and hazelnut accounted for approximately 40 and 60% of the forest leaf area, respectively. Sensible heat was the dominant consumer of forest net radiation during the preleaf period, while latent heat accounted for the majority of forest net radiation during the leafed period. Hazelnut transpiration accounted for 25% of the forest transpiration during the summer months. During the full-leaf period (June 1 to September 7) daytime dry-canopy mean aspen and hazelnut canopy conductances were 330 mmol m-2 s-1 (8.4 mm s-1) (70% of the total forest conductance) and 113 mmol m-2 s-1 (2.9 mm s-1) (24% of the total forest conductance), respectively. Maximum aspen and hazelnut canopy conductances were 1200 mmol m-2 s-1 (30 mm s-1) and 910 mmol m-2 s-1 (23 mm s-1 ), respectively, and maximum stomatal conductances were 490 mmol m-2 s-1 (12.5 mm s-1) and 280 mmol m-2 s-1 (7 m s-1), aspen and hazelnut, respectively. Both species showed a decrease in canopy conductance as the saturation deficit increased and both showed an increase in canopy conductance as the photosynthetic active radiation increased. There was a linear relationship between forest leaf area index and forest canopy conductance. The timing, duration, and maximum leaf area of this deciduous boreal forest was found to be an important control on transpiration at both levels of the canopy. The full-leaf hazelnut daytime mean Priestley and Taylor [1972] α coefficient of 1.22 indicated transpiration was largely energy controlled and the quantity of energy received at the hazelnut surface was a function of aspen leaf area. The full-leaf aspen daytime mean α of 0.91 indicated some stomatal control on transpiration, with a directly proportional relationship between forest leaf area and forest canopy conductance, varying α during much of the season through a range very sensitive to regional scale transpiration and surface-convective boundary layer feedbacks.

  7. DB 01-3 TREATMENT TARGET OF SYSTOLIC BLOOD PRESSURE IN DIABETES MAY DIFFER ACCORDING TO ETHNICITY (PRO).

    PubMed

    Kario, Kazuomi

    2016-09-01

    patients with diabetes or albuminuria. For these guidelines, we collected evidence from both Asian and Western studies, taking Asian characteristics into special consideration. In addition, the JSH2014 guidelines recommend that hypertensive patients with diabetes achieve home systolic BP values <125 mmHg. In our recent analysis of HONEST study, morning home systolic BP until 110 mmHg did not exhibit J-curve with both stroke and coronary artery disease in Japanese hypertensive patients including diabetic patients (Kario, et al. Hypertension 2014;64:989-996; J Am Coll Cardiol 2016;67:1519-1527).In this debate, I would like to stress the importance of ethnic differences, and the needs of Asian specific guidelines with the lower threshold of target systolic BP in Asian countries (Kario. Ann Glob Health 2016;82:254-273).

  8. Liquid Metal Droplet and Micro Corrugated Diaphragm RF-MEMS for reconfigurable RF filters

    NASA Astrophysics Data System (ADS)

    Irshad, Wasim

    Widely Tunable RF Filters that are small, cost-effective and offer ultra low power consumption are extremely desirable. Indeed, such filters would allow drastic simplification of RF front-ends in countless applications from cell phones to satellites in space by replacing switched-array of static acoustic filters and YIG filters respectively. Switched array of acoustic filters are de facto means of channel selection in mobile applications such as cell phones. SAW and BAW filters satisfy most criteria needed by mobile applications such as low cost, size and power consumption. However, the trade-off is a significant loss of 3-4 dB in modern cell phone RF front-end. This leads to need for power-hungry amplifiers and short battery life. It is a necessary trade-off since there are no better alternatives. These devices are in mm scale and consume mW. YIG filters dominate applications where size or power is not a constraint but demand excellent RF performance like low loss and high tuning ratio. These devices are measured in inches and require several watts to operate. Clearly, a tunable RF filter technology that would combine the cost, size and power consumption benefits of acoustic filters with excellent RF performance of YIG filters would be extremely desirable and imminently useful. The objective of this dissertation is to develop such a technology based upon RF-MEMS Evanescent-mode cavity filter. Two highly novel RF-MEMS devices have been developed over the course of this PhD to address the unique MEMS needs of this technology. The first part of the dissertation is dedicated to introducing the fundamental concepts of tunable cavity resonators and filters. This includes the physics behind it, key performance metrics and what they depend on and requirements of the MEMS tuners. Initial gap control and MEMS attachment method are identified as potential hurdles towards achieving very high RF performance. Simple and elegant solutions to both these issues are discussed in detail and have proved pivotal to this work. The second part of the dissertation focuses on the Liquid Metal Droplet RF-MEMS. A novel tunable RF MEMS resonator that is based upon electrostatic control over the morphology of a liquid metal droplet (LMD) is conceived. We demonstrate an LMD evanescent-mode cavity resonator that simultaneously achieves wide analog tuning from 12 to 18 GHz with a measured quality factor of 1400-1840. A droplet of 250-mum diameter is utilized and the applied bias is limited to 100 V. This device operates on a principle called Electro-Wetting On Dielectric (EWOD). The liquid metal employed is a non-toxic eutectic alloy of Gallium, Indium and Tin known as Galinstan. This device also exploits interfacial surface energy and viscous body forces that dominate at nanoliter scale. We then apply our Liquid Metal Droplet (LMD) RF-MEMS architecture to demonstrate a continuously tunable electrostatic Ku-Band Filter. A 2-pole bandpass filter with measured insertion loss of less than 0.4dB and 3dB FBW of 3.4% is achieved using a Galinstan droplet of 250mum diameter and bias limited to 100V. We demonstrate that the LMD is insensitive to gravity by performing inversion and tilt experiments. In addition, we study its thermal tolerance by subjecting the LMD up to 150° C. The third part of the dissertation is dedicated to the Micro-Corrugated Diaphragm (MCD) RF-MEMS. We present an evanescent-mode cavity bandpass filter with state-of-the-art RF performance metrics like 4:1 tuning ratio from 5 to 20 GHz with less than 2dB insertion loss and 2-6% 3dB bandwidth. Micro-Corrugated Diaphragm (MCD) is a novel electrostatic MEMS design specifically engineered to provide large-scale analog deflections necessary for such continuous and wide tunable filtering with very high quality factor. We demonstrate a 1.25mm radius and 2mum thick Gold MCD which provides 30mum total deflection with nearly 60% analog range. We also present a detailed and systematic MCD design methodology for relevant applications. To further demonstrate MCD versatility, we implement a bandstop MCD filter that cascades nine separate resonators to achieve a 6-24 GHz continuous tuning. The disseration concludes with a Galinstan Magnetohydrodynamic (MHD) micropump and summary of my doctoral work. Although presented at the very end of this dissertation, the MHD micropump was indeed the very starting point for all my doctoral research efforts. The invaluable lessons learned here paved the way for development of both LMD and MCD RF-MEMS.

  9. Level II scour analysis for Bridge 42 (HARDELMSTR0042) on Elm Street, crossing Cooper Brook, Hardwick, Vermont

    USGS Publications Warehouse

    Olson, Scott A.

    1996-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure HARDELMSTR0042 on Elm Street crossing Cooper Brook, Hardwick, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the New England Upland section of the New England physiographic province in north-central Vermont. The 16.6-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the overbanks are primarily grass covered with some brush along the immediate channel banks except the upstream right bank and overbank which is forested and the downstream left overbank which has a lumberyard. In the study area, Cooper Brook has a sinuous channel with a slope of approximately 0.005 ft/ft, an average channel top width of 50 ft and an average channel depth of 6 ft. The predominant channel bed materials are sand and gravel with a median grain size (D50) of 1.25 mm (0.00409 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 24, 1995, indicated that the reach was stable. The Elm Street crossing of Cooper Brook is a 39-ft-long, two-lane bridge consisting of one 37-foot concrete span (Vermont Agency of Transportation, written communication, March 17, 1995). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 40 degrees to the opening while the opening-skew-to-roadway is 45 degrees. On August 17, 1995 the site was revisited to investigate the effect of the August 4-5, 1995 flood on the structure. Channel features such as scour holes and point bars were shifted by the high flow event. Details of these changes can be found in the Level I data form in Appendix E. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and G. Scour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1993). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows. Contraction scour for all modelled flows ranged from 0.0 to 3.4 ft. The worst-case contraction scour occurred at the incipient-overtopping discharge which was less than the 100-year discharge. Abutment scour ranged from 7.1 to 10.4 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1993, p. 48). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

  10. On the output factor measurements of the CyberKnife iris collimator small fields: Experimental determination of the k{sub Q{sub c{sub l{sub i{sub n,Q{sub m{sub s{sub r}{sup f{sub c}{sub l}{sub i}{sub n},f{sub m}{sub s}{sub r}}}}}}}}} correction factors for microchamber and diode detectors

    SciTech Connect

    Pantelis, E.; Moutsatsos, A.; Zourari, K.; Petrokokkinos, L.; Sakelliou, L.; Kilby, W.; Antypas, C.; Papagiannis, P.; Karaiskos, P.; Georgiou, E.; Seimenis, I.

    2012-08-15

    Purpose: To measure the output factors (OFs) of the small fields formed by the variable aperture collimator system (iris) of a CyberKnife (CK) robotic radiosurgery system, and determine the k{sub Q{sub c{sub l{sub i{sub n,Q{sub m{sub s{sub r}{sup f{sub c}{sub l}{sub i}{sub n},f{sub m}{sub s}{sub r}}}}}}}}} correction factors for a microchamber and four diode detectors. Methods: OF measurements were performed using a PTW PinPoint 31014 microchamber, four diode detectors (PTW-60017, -60012, -60008, and the SunNuclear EDGE detector), TLD-100 microcubes, alanine dosimeters, EBT films, and polymer gels for the 5 mm, 7.5 mm, 10 mm, 12.5 mm, and 15 mm iris collimators at 650 mm, 800 mm, and 1000 mm source to detector distance (SDD). The alanine OF measurements were corrected for volume averaging effects using the 3D dose distributions registered in polymer gel dosimeters. k{sub Q{sub c{sub l{sub i{sub n,Q{sub m{sub s{sub r}{sup f{sub c}{sub l}{sub i}{sub n},f{sub m}{sub s}{sub r}}}}}}}}} correction factors for the PinPoint microchamber and the diode dosimeters were calculated through comparison against corresponding polymer gel, EBT, alanine, and TLD results. Results: Experimental OF results are presented for the array of dosimetric systems used. The PinPoint microchamber was found to underestimate small field OFs, and a k{sub Q{sub c{sub l{sub i{sub n,Q{sub m{sub s{sub r}{sup f{sub c}{sub l}{sub i}{sub n},f{sub m}{sub s}{sub r}}}}}}}}} correction factor ranging from 1.127 {+-} 0.022 (for the 5 mm iris collimator) to 1.004 {+-} 0.010 (for the 15 mm iris collimator) was determined at the reference SDD of 800 mm. The PinPoint k{sub Q{sub c{sub l{sub i{sub n,Q{sub m{sub s{sub r}{sup f{sub c}{sub l}{sub i}{sub n},f{sub m}{sub s}{sub r}}}}}}}}} correction factor was also found to increase with decreasing SDD; k{sub Q{sub c{sub l{sub i{sub n,Q{sub m{sub s{sub r}{sup f{sub c}{sub l}{sub i}{sub n},f{sub m}{sub s}{sub r}}}}}}}}} values equal to 1.220 {+-} 0.028 and 1.077 {+-} 0.016 were obtained for the 5 mm iris collimator at 650 mm and 1000 mm SDD, respectively. On the contrary, diode detectors were found to overestimate small field OFs and a correction factor equal to 0.973 {+-} 0.006, 0.954 {+-} 0.006, 0.937 {+-} 0.007, and 0.964 {+-} 0.006 was measured for the PTW-60017, -60012, -60008 and the EDGE diode detectors, respectively, for the 5 mm iris collimator at 800 mm SDD. The corresponding correction factors for the 15 mm iris collimator were found equal to 0.997 {+-} 0.010, 0.994 {+-} 0.009, 0.988 {+-} 0.010, and 0.986 {+-} 0.010, respectively. No correlation of the diode k{sub Q{sub c{sub l{sub i{sub n,Q{sub m{sub s{sub r}{sup f{sub c}{sub l}{sub i}{sub n},f{sub m}{sub s}{sub r}}}}}}}}} correction factors with SDD was observed. Conclusions: This work demonstrates an experimental procedure for the determination of the k{sub Q{sub c{sub l{sub i{sub n,Q{sub m{sub s{sub r}{sup f{sub c}{sub l}{sub i}{sub n},f{sub m}{sub s}{sub r}}}}}}}}} correction factors required to obtain small field OF results of increased accuracy.

  11. Chief Joseph Kokanee Enhancement Project; Strobe Light Deterrent Efficacy Test and Fish Behavior Determination at Grand Coulee Dam Third Powerplant Forebay, 2005-2006 Annual Report.

    SciTech Connect

    Simmons, M.; Johnson, Robert; McKinstry, C.

    2006-03-01

    four transducers generally were swimming north, parallel to the face of the dam. However, the distribution of swimming directions for fish detected by the transducer immediately to the north of the lights was bimodal, with some fish swimming south toward the lighted region. This behavior was similar to that seen at night when the lights were on. Fourth, kokanee, rainbow trout, and walleye were detected near the strobe lights. Data were obtained from three sources: fish size from the hydroacoustic sensors and fish species from gill netting and video recording. Fish ranging in length from 30 to 600 mm (averaging 125 mm) were detected by the splitbeam transducers. There was little difference in target strength for fish detected above 25 m depth with respect to time of day or light treatment. Below 25 m and closer to the strobe lights, larger fish were present when the lights were on during the night, and smaller fish were present during the day.

  12. ME 01-2 ASSESSMENT AND TREATMENT OF MORNING HYPERTENSION: UPDATE.

    PubMed

    Kario, Kazuomi

    2016-09-01

    hypertension" was defined as the average of morning BPs >135 mmHg for systolic BP, or >85mmHg for diastolic BP, regardless of office BPs with the definition of morning BP >135/85 mmHg regardless office BP in Clinician's Manual on Early Morning Risk Management in Hypertension in 2004 (Science Press, London, UK, 2004). "Masked morning hypertension" may be used for morning hypertension with office BP <140/90 mmHg. Morning BP could be measured by both ABPM (2 hour-average of ambulatory BPs after arsing) and home BP monitoring (the average of 2 measurements in the morning during 3 or more days). Morning hypertension could be diagnosed not only by home BP monitoring, but also by ABPM (ambulatory morning hypertension). When information on the time of arising is not available, the highest 1 hour moving average of consecutive systolic BPs between 6am and 10am could be calculate as the "Moving peak morning systolic BP" (Kario. Essential manual of 24 hour blood pressure management. Wiley, UK, pp.1-158.2015). The risk of morning BP surge may be underestimated by BP monitoring device with intermittent measurements. The innovation of wearable "surge" BP monitoring which could measure BP continuously will clarify the risk of morning BP surge (Kario. Prog Cardiovasc Dis 2016, in press).We are now proposing a three-step strategy for the morning BP-guided management of hypertension using home BP monitoring as follows. Step 1: Morning systolic BP <145 mmHg should be achieved by treatment; Step 2: The guideline level of 135 mmHg morning systolic BP should then be reached, and Step 3: Approx. 125 mmHg or less, which presents the lowest risk of cardiovascular events, should be achieved and maintained (Kario. Essential manual of 24 hour blood pressure management. Wiley, UK, pp.1-158.,2015). Non-specific medication for controlling morning hypertension includes long-acting drugs. Once-daily dosing antihypertensive agents, now widely used as conventional antihypertensive medication, has decreased the