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Sample records for ray titanium cage

  1. Harms titanium mesh cage fracture

    PubMed Central

    Klezl, Zdenek; Bookland, Markus J.; Wolinsky, Jean-Paul; Rezek, Zdenek; Gokaslan, Ziya L.

    2007-01-01

    Interbody fusion has become a mainstay of surgical management for lumbar fractures, tumors, spondylosis, spondylolisthesis and deformities. Over the years, it has undergone a number of metamorphoses, as novel instrumentation and approaches have arisen to reduce complications and enhance outcomes. Interbody fusion procedures are common and successful, complications are rare and most often do not involve the interbody device itself. We present here a patient who underwent an anterior L4 corpectomy with Harms cage placement and who later developed a fracture of the lumbar titanium mesh cage (TMC). This report details the presentation and management of this rare complication, as well as discusses the biomechanics underlying this rare instrumentation failure. PMID:17497187

  2. Percutaneous Vertebroplasty in a Broken Vertebral Titanium Implant (Titanium Mesh Cage)

    SciTech Connect

    Bierry, G.; Buy, X.; Mohan, P. Chandra; Cupelli, J.; Steib, J.P.; Gangi, A.

    2006-08-15

    We report the case of a percutaneous consolidation of a broken vertebral implant (Surgical Titanium Mesh Implants; DePuy Spine, Raynham, MA, USA) by vertebroplasty. Four years after anterior spondylectomy with cage implantation and stabilization with posterior instrumentation, the patient was admitted for excruciating back pain. Radiographs showed fracture of the cage, screw, and rod. An anterior surgical approach was deemed difficult and a percutaneous injection of polymethyl methacrylate into the cage was performed following posterior instrumentation replacement. This seems to be an interesting alternative to the classical anterior surgical approach, which is often difficult in postoperative conditions.

  3. Comparison of Clinical and Radiologic Results between Expandable Cages and Titanium Mesh Cages for Thoracolumbar Burst Fracture

    PubMed Central

    Lee, Gwang-Jun; Hur, Hyuk; Jang, Jae-Won; Kim, Tae-Sun; Kim, Soo-Han

    2014-01-01

    Objective A thoracolumbar burst fracture is usually unstable and can cause neurological deficits and angular deformity. Patients with unstable thoracolumbar burst fracture usually need surgery for decompression of the spinal canal, correction of the angular deformity, and stabilization of the spinal column. We compared two struts, titanium mesh cages (TMCs) and expandable cages. Methods 33 patients, who underwent anterior thoracolumbar reconstruction using either TMCs (n=16) or expandable cages (n=17) between June 2000 and September 2011 were included in this study. Clinical outcome was measured by visual analogue scale (VAS), American Spinal Injury Association (ASIA) scale and Low Back Outcome Score (LBOS) for functional neurological evaluation. The Cobb angle, body height of the fractured vertebra, the operation time and amount of intra-operative bleeding were measured in both groups. Results In the expandable cage group, operation time and amount of intraoperative blood loss were lower than that in the TMC group. The mean VAS scores and LBOS in both groups were improved, but no significant difference. Cobb angle was corrected higher than that in expandable cage group from postoperative to the last follow-up. The change in Cobb angles between preoperative, postoperative, and the last follow-up did not show any significant difference. There was no difference in the subsidence of anterior body height between both groups. Conclusion There was no significant difference in the change in Cobb angles with an inter-group comparison, the expandable cage group showed better results in loss of kyphosis correction, operation time, and amount of intraoperative blood loss. PMID:24851149

  4. Titanium mesh cage fracture after lumbar reconstruction surgery: a case report and literature review

    PubMed Central

    Wang, Shan-Jin; Liu, Xiao-Ming; Zhao, Wei-Dong; Wu, De-Sheng

    2015-01-01

    Titanium mesh cage (TMC) was introduced recently to provide anterior structural support and interbody fusion without the need to harvest bone from the iliac crest. Because of its good mechanical behavior and satisfactory clinical outcomes, TMC is commonly used for lumbar burst fractures. Here, we present a female patient who underwent a posterior-anterior L4 corpectomy with TMC placement and developed a cage fracture after 42 months. The patient refused the revision surgery and asked for conservative treatment. At the 3-month follow-up, she reported doing well, with no complaints of back pain or leg pain. There were three cases of TMC fracture have been previously reported in the literature. Only one patient performed a revision surgery with an expandable titanium cage, and all this three patients experienced a good outcome during the follow-up period. TMC fracture is a rare complication of spinal surgery. Close observation or surgical treatment should be considered to improve patient outcomes. Although cage placement, instability, subsidence, and both stress shielding and necrotic bone in the cage appear to play key roles in the pathogenesis of this rare complication, the exact mechanism of this condition remains undetermined. PMID:26131138

  5. Computational comparison of three posterior lumbar interbody fusion techniques by using porous titanium interbody cages with 50% porosity.

    PubMed

    Lee, Yung-Heng; Chung, Chi-Jen; Wang, Chih-Wei; Peng, Yao-Te; Chang, Chih-Han; Chen, Chih-Hsien; Chen, Yen-Nien; Li, Chun-Ting

    2016-04-01

    This study investigated the biomechanical response of porous cages and lumbar spine segments immediately after surgery and after bone fusion, in addition to the long-term effects of various posterior lumbar interbody fusion (PLIF) techniques, by using the finite element method. Lumbar L3-L4 models based on three PLIF techniques (a single cage at the center of the intervertebral space, a single cage half-anterior to the intervertebral space, and two cages bilateral to the intervertebral space) with and without bone ingrowth were used to determine the biomechanical response of porous cages and lumbar segments instrumented with porous titanium cages (cage porosity=50%, pore diameter=1mm). The results indicated that bone fusion enhanced the stability of the lumbar segments with porous cages without any posterior instrumentation and reduced the peak von Mises stress in the cortical bones and porous cages. Two cages placed bilateral to the intervertebral space achieved the highest structural stability in the lumbar segment and lowest von Mises stress in the cages under both bone fusion conditions. Under identical loading (2-Nm), the range of motion in the single cage at the center of the intervertebral space with bone fusion decreased by 11% (from 1.18° to 1.05°) during flexion and by 66.5% (from 4.46° to 1.5°) during extension in the single cage half-anterior to the intervertebral space with bone fusion compared with no-fusion models. Thus, two porous titanium cages with 50% porosity can achieve high stability of a lumbar segment with PLIF. If only one cage is available, placing the cage half-anterior to the intervertebral space is recommended for managing degenerated lumbar segments. PMID:26874064

  6. Endohedral fullerene with μ3-carbido ligand and titanium-carbon double bond stabilized inside a carbon cage.

    PubMed

    Svitova, A L; Ghiassi, K B; Schlesier, C; Junghans, K; Zhang, Y; Olmstead, M M; Balch, A L; Dunsch, L; Popov, A A

    2014-01-01

    In all metallofullerenes known before this work, metal atoms form single highly polar bonds with non-metal atoms in endohedral cluster. This is rather surprising for titanium taking into account the diversity of organotitanium compounds. Here we show that the arc-discharge synthesis of mixed titanium-lutetium metallofullerenes in the presence of ammonia, melamine or methane unexpectedly results in the formation of TiLu2C@I(h)-C80 with an icosahedral Ih(7) carbon cage. Single-crystal X-ray diffraction and spectroscopic studies of the compound reveal an unprecedented endohedral cluster with a μ3-carbido ligand and Ti-C double bond. The Ti(IV) in TiLu2C@I(h)-C80 can be reversibly reduced to the Ti(III) state. The Ti = C bonding and Ti-localized lowest unoccupied molecular orbital in TiLu2C@Ih-C80 bear a certain resemblance to titanium alkylidenes. TiLu2C@I(h)-C80 is the first metallofullerene with a multiple bond between a metal and the central, non-metal atom of the endohedral cluster. PMID:24699547

  7. The Safety and Efficacy of Cadaveric Allografts and Titanium Cage as a Fusion Substitutes in Pyogenic Osteomyelitis

    PubMed Central

    Kim, Hyun Woo; Ryu, Je-il

    2011-01-01

    Objective The safety and efficacy of various fusion substitutes in pyogenic osteomyelitis has not been investigated. We evaluated and compared the cadaveric allograft and titanium cages used to reconstruct, maintain alignment and achieve fusion in the management of pyogenic spinal infection. Methods There were 33 patients with pyogenic osteomyelitis underwent fusion in this study. Fifteen of the 33 patients were operated on by fusion with allografts (cadaveric patella bones) and 18 of those were operated with titanium mesh cages filled with autologous cancellous iliac bone. After the affected disc and vertebral body resection with pus drainage, cadaveric allograft or titanium cages were inserted into the resected space. Posterior transpedicular screw fixation and rod compression in resected space, where cadaveric allograft or titanium cages were inserted, was performed to prevent the malposition in all patients except in 1 case. Recurrent infection was identified by serial erythrocyte sedimentation rate and cross reactive protein follow-up. Osseous union and recurred infection available at a minimum of 2 years following operation was identified. The amount of kyphosis correction and the subsidence were measured radiographically. Results Spinal fusion was achieved in 29 of 33 patients. In the cadaveric allograft group, 93.3% of patient (14 of 15) showed the osseous union while 83.3% of patient (15 of 18) in the titanium cage group showed union. Subsidence was noted in 12 of the patients. Twelve patients (36.3%) showed unsettling amounts of subsidence postoperatively whereas 46.6% of patients in the cadaveric allograft group and 37.7% of patients in the titanium cage group showed similar subsidence, respectively. There were statistical difference in the fusion rate (p=0.397) and subsidence rate (p=0.276) between the two groups. There was significant statistical difference in the postoperative improvement of segmental kyphosis between the two groups (p=0.022), that is

  8. Efficacy of Titanium Mesh Cages for Anterior Column Reconstruction after Thoracolumbar Corpectomy

    PubMed Central

    2016-01-01

    Study Design This retrospective study was conducted to determine the safety and efficacy of titanium cage reconstruction and anterior plating after thoracolumbar corpectomy. Purpose To study the clinical and radiological outcome of anterior column reconstruction after thoracolumbar corpectomy. Overview of Literature Anterior column reconstruction aims to optimize neural decompression with adequate stabilization. Methods A series of 16 patients underwent reconstruction after thoracolumbar corpectomy to treat injury due to trauma (n=10), tuberculosis (n=3), and tumor (n=3). The average duration of follow-up was 18 months (range, 8–58 months). The degree of kyphosis, construct height, and the subsidence of the cage in relation to the vertebral endplates were measured. The approach was thoracoabdominal in 10 cases and retroperitoneal in 6 cases. Results Four patients were neurologically intact with Frankel grade E on admission, and all remained intact postoperatively. Of the 6 patients with Frankel grade D, all fully recovered full motor and sensory functions. Of the 6 patients with Frankel grade C, three improved one grade and the other three improved two grades. The mean height of the vertebra before surgery was 41 mm and the mean construct height immediately after surgery and at follow-up was 47 mm and 44 mm, respectively. Solid fusion was observed in all patients. The sagittal alignment of the fractured segment was restored immediately after surgery as a significant decrease in the local kyphotic angle. Conclusions Anterior instrumentation is an effective and safe treatment for thoracolumbar instability with satisfactory clinical and radiological outcomes. PMID:26949463

  9. SU-E-T-82: Comparison of Several Lumbar Intervertebral Fusion Titanium Cages with Respect to Their Backscattering Properties

    SciTech Connect

    Failing, T; Chofor, N; Poppinga, D; Schoenfeld, A; Poppe, B; Willborn, K

    2014-06-01

    Purpose: Investigating the backscatter dose factor with regards to structure and geometry of the surface material. Methods: The titanium cages used for this study representing both prototypes and well established products are made of a laser-sintered titanium alloy (AditusV GmbH, Berlin, Germany). A set of four radiochromic EBT3 films was used in a stacked geometry to measure the range and the magnitude of the expected surface dose enhancement due to the in comparison to water increased secondary electron release from the material. The measurement geometry and the small thickness of radiochromic EBT3 film allowed the dose measurement at distances of 0.1 mm, 0.9 mm, 1.7 mm and 2.5 mm from the probe surfaces. Water reference measurements were taken under equal conditions, in order to allow the calculation of the relative dose enhancement at the surface of a probe. Measurements were performed within a water phantom. An Epson Expression 10000 XL flatbed scanner was used for digitization. Results: Sintered titanium showed a dose enhancement factor of 1.22 at the surface of the material. The factor can be reduced to less than 1.10 by utilizing mesh structures. In both cases, the dose enhancement factor decreased to less than 1.03 at a distance of 1.7mm indicating the low energy of scattered electrons. Conclusion: Backscattering of titanium cages should be considered in treatment planning, especially when the cages are located close to organs at risk. While mesh structures were introduced to improve bone fusion with the implant structure, the potentially harmful surface dose enhancement is significantly reduced.

  10. Vanadium-pumped titanium x-ray laser

    DOEpatents

    Nilsen, Joseph

    1992-01-01

    A resonantly photo-pumped x-ray laser (10) is formed of a vanadium (12) and titanium (14) foil combination (16) that is driven by two beams (18, 20) of intense line focused (22, 24) optical laser radiation. Ground state neon-like titanium ions (34) are resonantly photo-pumped by line emission from fluorine-like vanadium ions (32).

  11. Vanadium-pumped titanium x-ray laser

    DOEpatents

    Nilsen, J.

    1992-05-26

    A resonantly photo-pumped x-ray laser is formed of a vanadium and titanium foil combination that is driven by two beams of intense line focused optical laser radiation. Ground state neon-like titanium ions are resonantly photo-pumped by line emission from fluorine-like vanadium ions. 4 figs.

  12. An X-ray diffraction study of titanium oxidation

    NASA Technical Reports Server (NTRS)

    Wiedemann, K. E.; Unnam, J.

    1984-01-01

    Titanium specimens of commercial purity were exposed at 1100 to 1400 F to laboratory air for times up to 100 hours. The extent of substrate contamination by interstitial oxygen was was determined by a new X-ray diffraction analysis involving transformation of X-ray diffraction intensity bands. The oxygen solid-solubility at the oxide-metal interfaces and its variation with time at temperature were also determined. Diffusion coefficients are deduced from the oxygen depth profiles.

  13. Titanium embedded cage structure formation in Al{sub n}Ti{sup +} clusters and their interaction with Ar

    SciTech Connect

    Torres, M. B.; Vega, A.; Balbás, L. C.; Aguilera-Granja, F.

    2014-05-07

    Recently, Ar physisorption was used as a structural probe for the location of the Ti dopant atom in aluminium cluster cations, Al{sub n}Ti{sup +} [Lang et al., J. Am. Soc. Mass Spectrom. 22, 1508 (2011)]. As an experiment result, the lack of Ar complexes for n > n{sub c} determines the cluster size for which the Ti atom is located inside of an Al cage. To elucidate the decisive factors for the formation of endohedrally Al{sub n}Ti{sup +}, experimentalists proposed detailed computational studies as indispensable. In this work, we investigated, using the density functional theory, the structural and electronic properties of singly titanium doped cationic clusters, Al{sub n}Ti{sup +} (n = 16–21) as well as the adsorption of an Ar atom on them. The first endohedral doped cluster, with Ti encapsulated in a fcc-like cage skeleton, appears at n{sub c} = 21, which is the critical number consistent with the exohedral-endohedral transition experimentally observed. At this critical size the non-crystalline icosahedral growth pattern, related to the pure aluminium clusters, with the Ti atom in the surface, changes into a endohedral fcc-like pattern. The map of structural isomers, relative energy differences, second energy differences, and structural parameters were determined and analyzed. Moreover, we show the critical size depends on the net charge of the cluster, being different for the cationic clusters (n{sub c} = 21) and their neutral counterparts (n{sub c} = 20). For the Al {sub n} Ti {sup +} · Ar complexes, and for n < 21, the preferred Ar adsorption site is on top of the exohedral Ti atom, with adsorption energy in very good agreement with the experimental value. Instead, for n = 21, the Ar adsorption occurs on the top an Al atom with very low absorption energy. For all sizes the geometry of the Al{sub n}Ti{sup +} clusters keeps unaltered in the Ar-cluster complexes. This fact indicates that Ar adsorption does not influence the cluster structure, providing support

  14. Anterior Decompression and Shortening Reconstruction with a Titanium Mesh Cage through a Posterior Approach Alone for the Treatment of Lumbar Burst Fractures

    PubMed Central

    Abe, Eiji; Miyakoshi, Naohisa; Murai, Hajime; Kobayashi, Takashi; Abe, Toshiki; Kikuchi, Kazuma; Shimada, Yoichi

    2012-01-01

    Study Design A retrospective study. Purpose To examine the efficacy and safety for a posterior-approach circumferential decompression and shortening reconstruction with a titanium mesh cage for lumbar burst fractures. Overview of Literature Surgical decompression and reconstruction for severely unstable lumbar burst fractures requires an anterior or combined anteroposterior approach. Furthermore, anterior instrumentation for the lower lumbar is restricted through the presence of major vessels. Methods Three patients with an L1 burst fracture, one with an L3 and three with an L4 (5 men, 2 women; mean age, 65.0 years) who underwent circumferential decompression and shortening reconstruction with a titanium mesh cage through a posterior approach alone and a 4-year follow-up were evaluated regarding the clinical and radiological course. Results Mean operative time was 277 minutes. Mean blood loss was 471 ml. In 6 patients, the Frankel score improved more than one grade after surgery, and the remaining patient was at Frankel E both before and after surgery. Mean preoperative visual analogue scale was 7.0, improving to 0.7 postoperatively. Local kyphosis improved from 15.7° before surgery to -11.0° after surgery. In 3 cases regarding the mid to lower lumbar patients, local kyphosis increased more than 10° by 3 months following surgery, due to subsidence of the cages. One patient developed severe tilting and subsidence of the cage, requiring additional surgery. Conclusions The results concerning this small series suggest the feasibility, efficacy, and safety of this treatment for unstable lumbar burst fractures. This technique from a posterior approach alone offers several advantages over traditional anterior or combined anteroposterior approaches. PMID:22708016

  15. A minimum 2-year comparative study of autologous cancellous bone grafting versus beta-tricalcium phosphate in anterior cervical discectomy and fusion using a rectangular titanium stand-alone cage.

    PubMed

    Yamagata, Toru; Naito, Kentaro; Arima, Hironori; Yoshimura, Masaki; Ohata, Kenji; Takami, Toshihiro

    2016-07-01

    Although titanium stand-alone cages are commonly used in anterior cervical discectomy and fusion (ACDF), there are several concerns such as cage subsidence after surgery. The efficacy of β-tricalcium phosphate (β-TCP) granules as a packing material in 1- or 2-level ACDF using a rectangular titanium stand-alone cage is not fully understood. The purpose of this study is to investigate the validity of rectangular titanium stand-alone cages in 1- and 2-level ACDF with β-TCP. This retrospective study included 55 consecutive patients who underwent ACDF with autologous iliac cancellous bone grafting and 45 consecutive patients with β-TCP grafting. All patients completed at least 2-year postoperative follow-up. Univariate and multivariate analyses were performed to examine the associations between study variables and nonunion after surgery. Significant neurological recovery after surgery was obtained in both groups. Cage subsidence was noted in 14 of 72 cages (19.4 %) in the autograft group and 12 of 64 cages (18.8 %) in the β-TCP group. A total of 66 cages (91.7 %) in the autograft group showed osseous or partial union, and 58 cages (90.6 %) in the β-TCP group showed osseous or partial union by 2 years after surgery. There were no significant differences in cage subsidence and the bony fusion rate between the two groups. Multivariate analysis using a logistic regression model showed that fusion level at C6/7, 2-level fusion, and cage subsidence of grades 2-3 were significantly associated with nonunion at 2 years after surgery. Although an acceptable surgical outcome with negligible complication appears to justify the use of rectangular titanium stand-alone cages in 1- and 2-level ACDF with β-TCP, cage subsidence after surgery needs to be avoided to achieve acceptable bony fusion at the fused segments. Fusion level at C6/7 or 2-level fusion may be another risk factor of nonunion. PMID:27098659

  16. Structural and mechanical evaluations of a topology optimized titanium interbody fusion cage fabricated by selective laser melting process.

    PubMed

    Lin, Chia-Ying; Wirtz, Tobias; LaMarca, Frank; Hollister, Scott J

    2007-11-01

    A topology optimized lumbar interbody fusion cage was made of Ti-Al6-V4 alloy by the rapid prototyping process of selective laser melting (SLM) to reproduce designed microstructure features. Radiographic characterizations and the mechanical properties were investigated to determine how the structural characteristics of the fabricated cage were reproduced from design characteristics using micro-computed tomography scanning. The mechanical modulus of the designed cage was also measured to compare with tantalum, a widely used porous metal. The designed microstructures can be clearly seen in the micrographs of the micro-CT and scanning electron microscopy examinations, showing the SLM process can reproduce intricate microscopic features from the original designs. No imaging artifacts from micro-CT were found. The average compressive modulus of the tested caged was 2.97+/-0.90 GPa, which is comparable with the reported porous tantalum modulus of 3 GPa and falls between that of cortical bone (15 GPa) and trabecular bone (0.1-0.5 GPa). The new porous Ti-6Al-4V optimal-structure cage fabricated by SLM process gave consistent mechanical properties without artifactual distortion in the imaging modalities and thus it can be a promising alternative as a porous implant for spine fusion. PMID:17415762

  17. Titanium

    SciTech Connect

    Fox, G.J.

    1997-01-01

    The article contains a summary of factors pertinent to titanium use. Geology and exploitation, production processes, global production, titanium dioxide and alloy applications, and the titanium market are reviewed. Potential applications outlined are for oil and gas equipment and for the automotive industry. Titanium alloys were selected for drilling risers for North Sea oil and gas drilling platforms due to a high strength-to-weight ratio and corrosion resistance. These properties also make titanium alloys attractive for auto parts, although the cost is currently prohibitive.

  18. Titanium

    USGS Publications Warehouse

    Bedinger, G.M.

    2013-01-01

    Titanium is the ninth most abundant element in the earth’s crust and can be found in nearly all rocks and sediments. It is a lithophile element with a strong affinity for oxygen and is not found as a pure metal in nature. Titanium was first isolated as a pure metal in 1910, but it was not until 1948 that metal was produced commercially using the Kroll process (named after its developer, William Kroll) to reduce titanium tetrachloride with magnesium to produce titanium metal.

  19. The determination of iron, titanium, and nickel in Apollo 14 samples by cathode ray polarography.

    NASA Technical Reports Server (NTRS)

    Maienthal, E. J.

    1972-01-01

    Methods have been developed and applied to the determination of iron, titanium, and nickel in Apollo 14 fine soil and rock by differential cathode ray polarography on the same sample. A 5 mg sample was sufficient for the determination of all 3 elements. Iron and titanium were determined either directly or after cupferron separation. Nickel was determined after dimethylglyoxime separation.

  20. X-ray fluorescence analysis of titanium alloys.

    PubMed

    Vassilaros, G L; McKaveney, J P

    1969-02-01

    An X-ray solution method is proposed for determining major amounts of Mo, Sn and Zr in Ti alloys. The method utilizes adjacent elements in the periodic table as internal standards and has been successfully applied to levels of 3-10% Sn, 11-40% Mo and 6-20% Zr. The procedure involves three steps: dissolving the sample with a suitable acid mixture; adding the suitable internal standard at the concentration levels experimentally found to give optimum accuracy and precision; analysing the resulting solution mixture by X-ray fluorescence. Antimony was found to be a suitable internal standard for its adjacent element tin at a concentration ratio of 3:1 Sb:Sn. Niobium was successfully used for both its adjacent elements, molybdenum and zirconium, at 2:1 concentration ratios, Nb:Mo and Nb:Zr. A number of elements non-adjacent to tin, molybdenum and zirconium (i.e., copper, bromine, titanium, bismuth and tantalum) were experimentally found unsuitable as internal standards. Concentration factors of the internal standard and the adjacent elements sought were found to affect significantly the precision of analysis. PMID:18960488

  1. In situ x-ray diffraction of shock-driven deformation and phase transformation in titanium

    NASA Astrophysics Data System (ADS)

    Bolme, Cynthia; Lazicki, Amy; Brown, Don; Gleason, Arianna; Cerreta, Ellen; Morrow, Ben; Ali, Suzanne; Swift, Damian; Nagler, Bob; Galtier, Eric; Granados, Eduardo; Milathianaki, Despina; Heimann, Phil

    2015-06-01

    Titanium alloys are employed in demanding engineering applications due to their high strength-to-weight ratio and their resistance to corrosion. Pure titanium and titanium with high levels of oxygen impurities were studied under laser-driven shock compression at the Matter in Extreme Conditions endstation at the Linac Coherent Light Source. In situ x-ray diffraction data were acquired during compression, showing the lattice-level response of titanium as it underwent plastic deformation and phase transformation. The kinetics of these processes and the influence of oxygen impurities on the deformation behavior will be presented.

  2. Bony Healing of Unstable Thoracolumbar Burst Fractures in the Elderly Using Percutaneously Applied Titanium Mesh Cages and a Transpedicular Fixation System with Expandable Screws

    PubMed Central

    Eschler, Anica; Ender, Stephan Albrecht; Schiml, Katharina; Mittlmeier, Thomas; Gradl, Georg

    2015-01-01

    Introduction There is a high incidence of vertebral burst fractures following low velocity trauma in the elderly. Treatment of unstable vertebral burst fractures using the same principles like in stable vertebral burst fractures may show less favourable results in terms of fracture reduction, maintenance of reduction and cement leakage. In order to address these shortcomings this study introduces cementless fixation of unstable vertebral burst fractures using internal fixators and expandable intravertebral titanium mesh cages in a one-stage procedure via minimum-invasive techniques. Material and Methods A total of 16 consecutive patients (median age 76 years, range 58–94) with unstable thoracolumbar burst fractures and concomitant osteoporosis were treated by an internal fixator inserted via minimum invasive technique one level above and below the fractured vertebra. Fracture reduction was achieved and maintained by transpedicular placement of two titanium mesh cages into the fractured vertebral body during the same procedure. Intra- and postoperative safety of the procedure as well as analysis of reduction quality was analysed by 3D C-arm imaging or CT, respectively. Clinical and radiographic follow-up averaged 10.4 months (range 4.5–24.5). Results Stabilization of the collapsed vertebral body was achieved in all 16 cases without any intraoperative complication. Surgical time averaged 102±6.6 minutes (71–194). The postoperative kyphotic angle (KA) and Cobb angle revealed significant improvements (KA 13.7° to 7.4°, p<0.001; Cobb 9.6° to 6.0°, p<0.002) with partial loss of reduction at final follow-up (KA 8.3°, Cobb 8.7°). VAS (Visual Analogue Scale) improved from 7.6 to 2.6 (p<0.001). Adjacent fractures were not observed. One minor (malposition of pedicle screw) complication was encountered. Conclusion Cementless fixation of osteoporotic burst fractures revealed substantial pain relief, adequate maintenance of reduction and a low complication rate

  3. The influence of cage positioning and cage type on cage migration and fusion rates in patients with monosegmental posterior lumbar interbody fusion and posterior fixation

    PubMed Central

    Abbushi, Alexander; Čabraja, Mario; Thomale, Ulrich-Wilhelm; Woiciechowsky, Christian

    2009-01-01

    In posterior lumbar interbody fusion, cage migrations and lower fusion rates compared to autologous bone graft used in the anterior lumbar interbody fusion procedure are documented. Anatomical and biomechanical data have shown that the cage positioning and cage type seem to play an important role. Therefore, the aim of the present study was to evaluate the impact of cage positioning and cage type on cage migration and fusion. We created a grid system for the endplates to analyze different cage positions. To analyze the influence of the cage type, we compared “closed” box titanium cages with “open” box titanium cages. This study included 40 patients with 80 implanted cages. After pedicle screw fixation, 23 patients were treated with a “closed box” cage and 17 patients with an “open box” cage. The follow-up period averaged 25 months. Twenty cages (25%) showed a migration into one vertebral endplate of <3 mm and four cages (5%) showed a migration of ≥3 mm. Cage migration was highest in the medio-medial position (84.6%), followed by the postero-lateral (42.9%), and the postero-medial (16%) cage position. Closed box cages had a significantly higher migration rate than open box cages, but fusion rates did not differ. In conclusion, cage positioning and cage type influence cage migration. The medio-medial cage position showed the highest migration rate. Regarding the cage type, open box cages seem to be associated with lower migration rates compared to closed box cages. However, the cage type did not influence bone fusion. PMID:19475436

  4. Outcome of instrumented lumbar fusion for low grade spondylolisthesis; Evaluation of interbody fusion with & without cages

    PubMed Central

    Fathy, Mostafa; Fahmy, Mohamed; Fakhri, Mazen; Aref, Khaled; Abdin, Khaled; Zidan, Ihab

    2010-01-01

    Object: The aim is to evalute the outcome of posterior lumbar interbody fusion with autologous bone graft versus titanium Cages, BAK system (Bagby – Kuslich, Spine Tech, Inc. Minneapolis, MN) for low grade spondyloisthesis (Grade1,11). Interbody cages have been developed to replace tricortical Interbody grafts in posterior lumbar interbody fusion (PLIF) procedures. The cages provide immediate post operative stability and facilitate bony union with cancellous bone packed in the cage itself. METHOD: We Evaluated 50 consecutive patients in whom surgery was performed between June 2000 to June 2003 in the Main Alexandria University Hospital at EGYPT. Twenty five patients were operated using autologous bone graft and 25 patients using the BAK cages. The neuro–radiologic al work up consisted of; plain X – ray lumbosacral spine including dynamic films preoperative and postoperative follow up; C.T lumbosacral spine and MRI lumbosacral spine. The surgery was performed at L4-5 level in 34 cases and at L5-S1 level in 16 cases. The median follow up was 15 months. RESULTS: Satisfactory fusion was obtained at all levels at a minimum one year follow – up. The fusion rate was 96% (24 patients) for the cage group and 80% (20 patients) for bone graft group however clinical improvement was 64% (16 patients) for those with bone graft group. CONCLUSION: A higher fusion rates and a better clinical outcome have been obtained by Instrumented PLIF with titanium cages that with bone graft. Inderbody fusion cages help to stabilize spainal segment primarily by distracting them as well as by allowing bone ingrowth and fusion. The procedure is safe and effective with 96% fusion rate and 76% overall Satisfactory rate. The use of cages help to distract the space between the vertebral bodies making the correction of the degree of spondylolisthesis easier. Long term follow up revealed better fusion rate and better realignment and less resorption with cages than with bone grafts. PMID

  5. TiN thin film deposition by cathodic cage discharge: effect of cage configuration and active species

    NASA Astrophysics Data System (ADS)

    de Freitas Daudt, N.; Pereira Barbosa, J. C.; Cavalcante Braz, D.; Barbalho Pereira, M.; Alves Junior, C.

    2012-12-01

    Plasma cathodic cage technique was developed recently in order to eliminate phenomena such as edge effects and overheating, which occur during conventional nitriding processes. In this work, the effect of plasma active species and cage configurations during thin film deposition of TiN were studied. This compound was chosen because its properties are very sensitive to slight variations in chemical composition and film thickness, becoming a good monitoring tool in fabrication process control. In order to verify the effect of cage geometry on the discharge and characteristics of the grown film, a cage made of titanium was used with different numbers and distribution of holes. Furthermore, different amounts of hydrogen were added to the Ar + N2 plasma atmosphere. Flow rates of Ar and N2 gas were fixed at 4 and 3 sccm, respectively and flow rates of H2 gas was 0, 1 and 2 sccm. Plasma species, electrical discharge and physical characteristics of the grown film were analyzed by Optical Emission Spectroscopy (OES), Atomic Force Microscopy (AFM), X-Ray Diffraction. It was observed by OES that the luminous intensity associated to Hα species is not proportional to flow rate of H2 gas. Electrical efficiency of the system, crystal structure and topography of the TiN film are strongly influenced by this behavior. For constant flow rate of H2 gas, it was found that with more holes at the top of the cage, deposition rate, crystallinity and roughness are higher, if compared to cages with a small number of holes at the top of cage. On the other hand, the opposite behavior was observed when more holes were located at the sidewall of cage.

  6. An X-ray monitor for measurement of a titanium tritide target thickness.

    NASA Technical Reports Server (NTRS)

    Alger, D. L.; Steinberg, R.

    1972-01-01

    An X-ray device capable of measuring titanium tritide film thickness from 0.1 to 30 microns has been built and tested. The monitor was designed for use in a rotating target system which used thick targets and incorporated a sputtering electrode to remove depleted layers from the target surface. The thickness measurement can be done in the presence of an intense background of bremsstrahlung and characteristic titanium X-radiation. A measurement can be accomplished in situ in two hours with reasonable accuracy.

  7. An X-ray monitor for measurement of a titanium tritide target thickness

    NASA Technical Reports Server (NTRS)

    Alger, D. L.; Steinberg, R.

    1972-01-01

    An X-ray device capable of measuring titanium tritide film thickness from 0.1 to 30 micrometers has been built and tested. The monitor was designed for use in a rotating target system which used thick targets and incorporated a sputtering electrode to remove depleted layers from the target surface. The thickness measurement can be done in the presence of an intense background of bremsstrahlung and characteristic titanium X-radiation. A measurement can be accomplished in situ in two hours with reasonable accuracy.

  8. Synchrotron X-ray CT characterization of titanium parts fabricated by additive manufacturing. Part I. Morphology.

    PubMed

    Scarlett, Nicola Vivienne Yorke; Tyson, Peter; Fraser, Darren; Mayo, Sheridan; Maksimenko, Anton

    2016-07-01

    Synchrotron X-ray tomography has been applied to the study of titanium parts fabricated by additive manufacturing (AM). The AM method employed here was the Arcam EBM(®) (electron beam melting) process which uses powdered titanium alloy, Ti64 (Ti alloy with approximately 6%Al and 4%V), as the feed and an electron beam for the sintering/welding. The experiment was conducted on the Imaging and Medical Beamline of the Australian Synchrotron. Samples were chosen to examine the effect of build direction and complexity of design on the surface morphology and final dimensions of the piece. PMID:27359150

  9. Artifacts and thresholding in X-ray CT of a cortical bone and titanium composite

    SciTech Connect

    Sutherland, C.J.; Gayou, D.E.

    1996-05-01

    X-Ray CT has the potential to provide precise and accurate data from which the mechanical properties of bone can be calculated. Such data would be useful in understanding the response of bone tissue to implants. Various artifacts can, however, degrade accuracy of the data. The aim of this study was to measure the artifactual errors produced in CT of a simulated femoral bone-titanium composite and to propose a method to correct for them. A composite phantom that simulates cortical bone and a titanium implant was designed and constructed. The phantom was scanned and the image data were analyzed over a range of thresholds with image analysis software developed for this study. The outer (OD) and inner (ID) diameter and the CT number of the cortical bone, with and without titanium, were measured over a range of cortical thicknesses. While ID can be accurately measured by choosing the proper threshold (800 HU), OD, even at optimal threshold, will be underestimated by {approx}2%. If a proper threshold is selected, CT number can also be accurately determined. Errors of tip to 5%, however, are produced by titanium unless corrected by proper threshold selection. Intramedullary titanium is not a deterrent to obtaining accurate measurements of cortical bone dimensions and properties. Proper choice of thresholds for image analysis of CT scan data can yield accuracy and precision of 2%. 34 refs., 3 figs.

  10. Titanium dioxide nanofiber-cotton targets for efficient multi-keV x-ray generation

    SciTech Connect

    Tanabe, Minoru; Nishimura, Hiroaki; Fujioka, Shinsuke; Nagai, Keiji; Yamamoto, Norimasa; Mima, Kunioki; Gu, Zhong-Ze; Pan, Chao; Girard, Frederic; Primout, Michel; Villette, Bruno; Brebion, Didier; Fournier, Kevin B.; Fujishima, Akira

    2008-08-04

    Multi-keV x-ray generation from low-density (27{+-}7 mg/cm{sup 3}) nanofiber-cotton targets composed of titanium dioxide has been investigated. The cotton targets were heated volumetrically and supersonically to a peak electron temperature of 2.3 keV, which is optimal to yield Ti K-shell x rays. Considerable enhancement of conversion efficiency [(3.7{+-}0.5)%] from incident laser energy into Ti K-shell x rays (4-6 keV band) was attained in comparison with that [(1.4{+-}0.9)%] for a planar Ti-foil target.

  11. Time-Resolved X-ray Scattering and Raman Spectroscopic Studies of Formation of a Uranium-Vanadium-Phosphorus-Peroxide Cage Cluster.

    PubMed

    Qiu, Jie; Dembowski, Mateusz; Szymanowski, Jennifer E S; Toh, Wen Cong; Burns, Peter C

    2016-07-18

    Combining reactants in water under ambient conditions results in the assembly and crystallization of 2.6 nm diameter cage clusters designated U48V6P48 within 3 weeks. These consist of 24 uranyl hexagonal bipyramids, 24 uranyl pentagonal bipyramids, six vanadyl square pyramids, and 48 phosphate tetrahedra. Peroxide-bridged dimers of uranyl hexagonal bipyramids are linked directly to vanadyl-stabilized tetramers of uranyl pentagonal bipyramids to form the cage, with phosphate tetrahedra providing additional linkages between these two units. Time-resolved small-angle X-ray scattering and Raman spectroscopy indicate that the combination of the reactants initially resulted in simultaneous formation of smaller uranyl peroxide cages and vanadyl peroxide complexes. The disappearance of the smaller uranyl peroxide cages from solution coincides with the diminution of uncoordinated peroxide, both of which occurred before the assembly of the relatively peroxide-poor U48V6P48, which clearly occurred in solution prior to its crystallization. PMID:27355615

  12. Titanium and germanium lined hohlraums and halfraums as multi-keV x-ray radiators

    NASA Astrophysics Data System (ADS)

    Girard, F.; Primout, M.; Villette, B.; Stemmler, Ph.; Jacquet, L.; Babonneau, D.; Fournier, K. B.

    2009-05-01

    As multi-keV x-ray radiators, hohlraums and halfraums with inner walls coated with metallic materials (called liner) have been tested for the first time with laser as the energy drive. For titanium, conversion efficiencies (CEs) are up to ˜14% for emission into 4π, integrating between 4.6 and 6.5 keV when a large diameter hohlraum is used. Germanium CE is ˜0.8% into 4π between 9 and 13 keV. The highest CEs have been obtained with a 1 ns squared pulse and phase plates giving laser absorption near 99%. These high CEs are due to long-lasting, good plasma conditions for multi-keV x-ray production maintained by plasma confinement inside the plastic cylinder and plasma collision leading to a burst of x rays at a time that depends on target size. As photon emitters at 4.7 keV, titanium-lined hohlraums are the most efficient solid targets and data are close to CEs for gas targets, which are considered as the upper limit for x-ray yields since their low density allows good laser absorption and low kinetics losses. As 10.3 keV x-ray emitters, exploded germanium foils give best results one order of magnitude more efficient than thick targets; doped aerogels and lined hohlraums give similar yields, about three times lower than those from exploded foils.

  13. Titanium local structure in tektite probed by X-ray absorption fine structure spectroscopy.

    PubMed

    Wang, Ling; Yoshiasa, Akira; Okube, Maki; Takeda, Takashi

    2011-11-01

    The local structure of titanium in tektites from six strewn fields was studied by Ti K-edge X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) in order to provide quantitative data on Ti-O distance and Ti coordination number. The titanium in tektites possessed different coordination environment types. XANES spectra patterns revealed resemblance to high-temperature TiO(2)-SiO(2) glass and TiO(2) anatase. All samples showed that the valence of Ti is 4+. Based on the Ti-O distances, coordination numbers and radial distribution function determined by EXAFS analyses, the tektites were classified into three types: type I, Ti occupies a four-coordinated tetrahedral site with Ti-O distances of 1.84-1.79 Å; type II, Ti occupies a five-coordinated trigonal bipyramidal or tetragonal pyramidal site with Ti-O distances of 1.92-1.89 Å; type III, Ti occupies a six-coordinated octahedral site with Ti-O distances of 2.00-1.96 Å. Although Ti occupies the TiO(6) octahedral site in most titanium minerals under ambient conditions, some tektites have four- and five-coordinated Ti. This study indicated that the local structure of Ti might change in impact events and the following stages. PMID:21997913

  14. Synchrotron X-ray CT characterization of titanium parts fabricated by additive manufacturing. Part II. Defects.

    PubMed

    Scarlett, Nicola Vivienne Yorke; Tyson, Peter; Fraser, Darren; Mayo, Sheridan; Maksimenko, Anton

    2016-07-01

    Synchrotron X-ray tomography (SXRT) has been applied to the study of defects within three-dimensional printed titanium parts. These parts were made using the Arcam EBM(®) (electron beam melting) process which uses powdered titanium alloy, Ti64 (Ti alloy with approximately 6%Al and 4%V) as the feed and an electron beam for the sintering/welding. The experiment was conducted on the Imaging and Medical Beamline of the Australian Synchrotron. The samples represent a selection of complex shapes with a variety of internal morphologies. Inspection via SXRT has revealed a number of defects which may not otherwise have been seen. The location and nature of such defects combined with detailed knowledge of the process conditions can contribute to understanding the interplay between design and manufacturing strategy. This fundamental understanding may subsequently be incorporated into process modelling, prediction of properties and the development of robust methodologies for the production of defect-free parts. PMID:27359151

  15. Periodic cages.

    PubMed

    Diudea, Mircea V; Nagy, Csaba L; Silaghi-Dumitrescu, Ioan; Graovac, Ante; Janezic, Dusanka; Vikić-Topić, Drazen

    2005-01-01

    Various cages are constructed by using three types of caps: f-cap (derived from spherical fullerenes by deleting zones of various size), kf-cap (obtainable by cutting off the polar ring, of size k), and t-cap ("tubercule"-cap). Building ways are presented, some of them being possible isomerization routes in the real chemistry of fullerenes. Periodic cages with ((5,7)3) covering are modeled, and their constitutive typing enumeration is given. Spectral data revealed some electronic periodicity in fullerene clusters. Semiempirical and strain energy calculations complete their characterization. PMID:15807490

  16. Strain measurement of pure titanium covered with soft tissue using X-ray diffraction.

    PubMed

    Fujisaki, Kazuhiro; Tadano, Shigeru

    2010-03-01

    Measurement of the stress and strain applied to implants and bone tissue in the human body are important for fracture prediction and evaluations of implant adaptation. The strain of titanium (Ti) materials can be measuring by X-ray diffraction techniques. This study applied X-ray diffraction to the skin tissue-covered Ti. Characteristic X-rays of Mo Kalpha were used and the X-rays diffracted from the Ti were detected through the covering skin tissue. The X-ray absorption by skin tissue is large under the diffracted X-rays detected in low angles because the length of penetration depends on the angle of inclination, equal to the Bragg angle. The effects of skin tissue to detect the diffracted X-rays were investigated in the experiments. And the strain measurements were conducted under bending loads applied to the Ti specimen. The effect of skin tissue was absorption of X-rays as well as the X-rays scattered from the physiological saline contained in the tissue. The X-rays scattered by the physiological saline creates a specific background pattern near the peaks from the (002) and (011) lattice planes of Ti in the X-ray diffraction profile. Diffracted X-rays from the Ti were detected after being transmitted through 1 mm thick skin tissue by Mo Kalpha. Individual peaks such as (010), (002), (011), and (110) were clearly established by using a parallel beam arrangement. The strains of (110) lattice planes were measured with or without the tissue cover were very similar. The strain of the (110) lattice planes of Ti could be measured by Mo Kalpha when the Ti specimen was located under the skin tissue. PMID:20459192

  17. X-ray photo-emission and energy dispersive spectroscopy of HA coated titanium

    SciTech Connect

    Drummond, J.L.; Steinberg, A.D.; Krauss, A.R.

    1997-08-01

    The purpose of this study was to determine the chemical composition changes of hydroxyapatite (HA) coated titanium using surface analysis (x-ray photo-emission) and bulk analysis (energy dispersive spectroscopy). The specimens examined were controls, 30 minutes and 3 hours aged specimens in distilled water or 0.2M sodium phosphate buffer (pH 7.2) at room temperature. Each x-ray photo-emission cycle consisted of 3 scans followed by argon sputtering for 10 minutes for a total of usually 20 cycles, corresponding to a sampling depth of {approximately} 1500 {angstrom}. The energy dispersive spectroscopy analysis was on a 110 by 90 {mu}m area for 500 sec. Scanning electron microscopy examination showed crystal formation (3P{sub 2}O{sub 5}*2CAO*?H{sub 2}O by energy dispersive spectroscopy analysis) on the HA coating for the specimens aged in sodium phosphate buffer. The x-ray photo-emission results indicated the oxidation effect of water on the titanium (as TiO{sub 2}) and the effect of the buffer to increase the surface concentration of phosphorous. No differences in the chemical composition were observed by energy dispersive spectroscopy analysis. The crystal growth was only observed for the sodium phosphate buffer specimens and only on the HA surface.

  18. X-Ray photoelectron spectroscopy study of radiofrequency-sputtered titanium, carbide, molybdenum carbide, and titanium boride coatings and their friction properties

    NASA Technical Reports Server (NTRS)

    Brainard, W. A.; Wheeler, D. R.

    1977-01-01

    Radiofrequency sputtered coatings of titanium carbide, molybdenum carbide and titanium boride were tested as wear resistant coatings on stainless steel in a pin on disk apparatus. X-ray photoelectron spectroscopy (XPS) was used to analyze the sputtered films with regard to both bulk and interface composition in order to obtain maximum film performance. Significant improvements in friction behavior were obtained when properly biased films were deposited on deliberately preoxidized substrates. XPS depth profile data showed thick graded interfaces for bias deposited films even when adherence was poor. The addition of 10 percent hydrogen to the sputtering gas produced coatings with thin poorly adherent interfaces. Results suggest that some of the common practices in the field of sputtering may be detrimental to achieving maximum adherence and optimum composition for these refractory compounds.

  19. Mechanical study of rat soleus muscle using caged ATP and X-ray diffraction: high ADP affinity of slow cross-bridges.

    PubMed Central

    Horiuti, K; Yagi, N; Takemori, S

    1997-01-01

    1. The cross-bridges in slow- and fast-twitch fibres (taken, respectively, from soleus and psoas muscles of rats) were examined in mechanical experiments using caged ATP and X-ray diffraction, to compare their binding of ATP and ADP. 2. Caged ATP was photolysed in rigor fibres. When ADP was removed from pre-photolysis fibres, the initial relaxation (+/- Ca2+) in soleus was as fast as that in psoas fibres, whereas the subsequent contraction (+Ca2+) was slower in soleus than in psoas. The ATPase rate during the steady-state contraction was also slower in soleus fibres. 3. When ADP was added to pre-photolysis fibres (+/- Ca2+), tension developed even in the initial phase, the overall tension development being biphasic. Both initial and late components of the Ca(2+)-free contraction were enhanced when ADP was added before photolysis, although pre-photolysis ADP was not a prerequisite for the late component. The effect of ADP was greater in soleus than in psoas fibres. Static experiments on rigor fibres revealed a higher ADP affinity in soleus fibres. 4. The intensity of the actin layer-line from ADP rigor soleus fibres decreased rapidly on photorelease of ATP. We conclude that, despite the tight ADP binding of the soleus cross-bridge, its isometric reaction is not rate limited by the 'off' rate of ADP. PMID:9263922

  20. Titanium-Dioxide Nano-Fiber-Cotton Targets for Efficient Multi-keV X-Ray Generation

    SciTech Connect

    Tanabe, M; Nishimura, H; Fujioka, S; Nagai, K; Yamamoto, N; Gu, Z; Pan, C; Girard, F; Primout, M; Villette, B; Brebion, D; Fournier, K B; Fujishima, A; Mima, K

    2008-06-12

    Multi-keV x-ray generation from low-density (27 {+-} 7 mg/cc) nano-fiber-cotton targets composed of titanium-dioxide has been investigated. The cotton targets were heated volumetrically and supersonically to a peak electron temperature of 2.3 keV, which is optimal to yield Ti K-shell x rays. Considerable enhancement of conversion efficiency (3.7 {+-} 0.5%) from incident laser energy into Ti K-shell x rays (4-6 keV band) was attained in comparison with that (1.4 {+-} 0.9%) for a planar Ti-foil target.

  1. X-Ray Analysis of the Ultrafine-Grained VT6 Titanium Alloy Subjected to Flat Rolling

    NASA Astrophysics Data System (ADS)

    Sitdikov, V. D.; Alexandrov, I. V.; Danilenko, V. N.; Popov, V. A.

    2015-10-01

    Results are presented of experimental x-ray diffraction analysis of the microstructure of VT6 titanium alloy billets in ultrafine-grained (UFG) state subjected to flat rolling. The UFG state was formed by six cycles of isothermal multiaxial forging at 650°C. The regularities of changes of the structural parameters (the lattice parameter, coherently scattering domain size, and microdistortions of the crystal lattice) are revealed depending on the degree of flat rolling reduction.

  2. X-ray diffraction analysis of titanium tritide film during 1600 days

    NASA Astrophysics Data System (ADS)

    Xiaosong, Zhou; Xinggui, Long; Lin, Zhang; Shuming, Peng; Shunzhong, Luo

    2010-01-01

    The generation and accumulation of 3He by tritium decay modified the physical and chemical properties of tritides. Here the evolution of lattice defects in long-aged titanium tritide films is investigated by X-ray diffraction and changes in the positions, intensities and line shapes of diffraction peaks have been determined over a period of about 1600 days (>4 years). Texture effects are also observed by biased intensities in standard θ-2θ scans. The results show that the TiT1.5 film keeps an fcc structure during 1600 days and reveals an hkl-dependent unit-cell expansion and line width broadening which are interpreted in terms of isolated tetrahedral interstitial 3He atoms and isolated bubble growth models by dislocation loop-punching or dislocation dipole expansion combined with Krivoglaz theory. In the first 12 days of aging, isolated tetrahedral interstitial 3He atoms or 3He clusters are formed, then interstitial 3He atoms diffuse into (1 1 1) planes and precipitate into clusters. The spontaneous formation of Frenkel pairs, the self-interstitial atoms produced are built into dislocations resulting in formation platelet bubbles and dislocation dipoles between 12 and 27 days. Above 27 days, multiple stages of 3He bubbles growth appear: (1) between 27 and 85 days platelet helium bubbles growth by dislocation dipoles expansion, (2) between 85 and 231 days the transition from platelet bubbles to sphere bubbles by loop emission, (3) after 231 days sphere bubbles growth by dislocation loop-punching and probably formation of sub-grain boundaries by dislocation rearrangement.

  3. X-ray diffraction, optical microscopy, and microhardness studies of gas nitrided titanium alloys and titanium aluminide

    SciTech Connect

    Sha, W. Haji Mat Don, M.A.; Mohamed, A.; Wu, X.; Siliang, B.; Zhecheva, A.

    2008-03-15

    Thermochemical surface gas nitriding of {beta}21s, Timetal 205 and a Ti-Al alloy was conducted using differential scanning calorimeter equipment, in nominally pure nitrogen at 850 deg. C and 950 deg. C ({beta}21s), 730 deg. C and 830 deg. C (Timetal 205), and 950 deg. C and 1050 deg. C (Ti-Al) for 1 h, 3 h and 5 h. X-ray diffraction analyses showed new phases formed in the nitrided layer, depending on the alloy and the time and the temperature of nitriding. Microstructures were analyzed using optical microscopy. Cross-sectional microhardness profiles of cross-sectional samples after nitriding were obtained using a Knoop indenter.

  4. Swift/BAT Detection of Hard X-Rays from Tycho's Supernova Remnant: Evidence for Titanium-44

    NASA Astrophysics Data System (ADS)

    Troja, E.; Segreto, A.; La Parola, V.; Hartmann, D.; Baumgartner, W.; Markwardt, C.; Barthelmy, S.; Cusumano, G.; Gehrels, N.

    2014-12-01

    We report Swift/Burst Alert Telescope survey observations of the Tycho's supernova remnant, performed over a period of 104 months since the mission's launch. The remnant is detected with high significance (>10σ) below 50 keV. We detect significant hard X-ray emission in the 60-85 keV band, above the continuum level predicted by a simple synchrotron model. The location of the observed excess is consistent with line emission from radioactive titanium-44, so far reported only for Type II supernova explosions. We discuss the implications of these results in the context of the galactic supernova rate, and nucleosynthesis in Type Ia supernova.

  5. Local structure of Titanium in natural glasses probed by X-ray absorption fine structure

    NASA Astrophysics Data System (ADS)

    Wang, L.; Yoshiasa, A.; Okube, M.; Nakatani, T.; Hayasaka, Y.; Isobe, H.

    2013-04-01

    Synchrotron radiation has been used to collect titanium K-edge absorption spectra of a suite of natural glasses (tektites, impact glasses, fault rocks and volcanic glasses). XANES and XAFS analysis provided the qualitative and quantitative information of Ti oxidation state, Ti-O distance and site geometry. Tektites possess four-, five-, six-coordinated Ti, whereas fault rock-pseudotachylite, volcanic glasses and impact glass only presented five- and six-coordinated Ti. This study indicated that different petrogenesis of natural glasses has different local structures of titanium.

  6. Self-Assembled Pyridine-Dipyrrolate Cages.

    PubMed

    Zhang, Huacheng; Lee, Juhoon; Lammer, Aaron D; Chi, Xiaodong; Brewster, James T; Lynch, Vincent M; Li, Hao; Zhang, Zhan; Sessler, Jonathan L

    2016-04-01

    An inherently nonlinear pyridine dipyrrolate ligand, namely 2,6-bis(3,4-diethyl-5-carboxy-1H-pyrrol-2yl)pyridine (compound 1), is able to distinguish between different zinc(II) cation sources, namely Zn(acac)2 and Zn(OAc)2, respectively. This differentiation is manifest both in terms of the observed fluorescent behavior in mixed organic media and the reaction chemistry. Treatment of 1 with Zn(acac)2 gives rise to a cage dimer, cage-1, wherein two molecules of compound 1 act as double bridging units to connect two individual cage subunits. As inferred from X-ray crystallographic studies, this cage system consists of discrete zinc dimers with hydroxide bridges that, with the assistance of bound DMF solvent molecules, serve to fix the geometry and orientation of the pyridine dipyrrolate building blocks. When a different zinc source, Zn(OAc)2, is used to carry out an ostensibly similar complexation reaction with compound 1, an acetate-bridged 1D abacus-like cage polymer is obtained as inferred from X-ray diffraction analysis. This extended solid state structure, cage-2, contains individual zinc dimer cage submits and appears stabilized by solvent molecules (DMF) and the counteranion (acetate). Rod-like assemblies are also observed by DLS and SEM. This construct, in contrast to cage-1, proved fluorescent in mixed organic media. The structure of the ligand itself (i.e., in the absence of Zn(II)) was confirmed by X-ray crystallographic analysis and was found to assemble into a supramolecular polymer. Conversion to a dimer form was seen upon the addition of TBAOAc. On the basis of the metric parameters, the structures seen in the solid state are stabilized via hydrogen bonding interactions involving solvent molecules. PMID:26972781

  7. New Ventilated Isolation Cage

    PubMed Central

    Cook, Reginald O.

    1968-01-01

    A multifunction lid has been developed for a commercially available transparent animal cage which permits feeding, watering, viewing, long-term holding, and local transport of laboratory rodents on experiment while isolating the surrounding environment. The cage is airtight except for its inlet and exhaust high-efficiency particulate air filters, and it is completely steam-sterilizable. Opening of the cage's feed and water ports causes an inrush of high velocity air which prevents back-migration of aerosols and permits feeding and watering while eliminating need for chemical vapor decontamination. Ventilation system design permits the holding in adjacent cages of animals infected with different organisms without danger of cross-contamination; leaves the animal room odor-free; reduces required bedding changes to twice a month or less, and provides investigators with capability to control precisely individual cage ventilation rates. Forty-eight cages can be conveniently placed on a standard NIH “shoebox” cage rack (60 inches wide × 28 inches deep × 74 inches high) fitted with a simple manifold exhaust system. The entire system is mobile, requiring only an electrical power outlet. Principal application of the caging system is in the area of preventing exposure of animal caretakers to pathogenic substances associated with the animal host, and in reducing handling of animals and their exposure to extraneous contamination. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 9 PMID:5659368

  8. Cathodic cage plasma deposition of TiN and TiO{sub 2} thin films on silicon substrates

    SciTech Connect

    Sousa, Romulo R. M. de; Sato, Patricia S.; Nascente, Pedro A. P.; Viana, Bartolomeu C.; Alves, Clodomiro; Nishimoto, Akio

    2015-07-15

    Cathodic cage plasma deposition (CCPD) was used for growing titanium nitride (TiN) and titanium dioxide (TiO{sub 2}) thin films on silicon substrates. The main advantages of the CCPD technique are the uniformity, tridimensionality, and high rate of the film deposition that occurs at higher pressures, lower temperatures, and lower treatment times than those used in conventional nitriding treatments. In this work, the influence of the temperature and gas atmosphere upon the characteristics of the deposited films was investigated. The TiN and TiO{sub 2} thin films were characterized by x-ray diffraction, scanning electron microscopy, and Raman spectroscopy to analyze their chemical, structural, and morphological characteristics, and the combination of these results indicates that the low-cost CCPD technique can be used to produce even and highly crystalline TiN and TiO{sub 2} films.

  9. SWIFT/BAT DETECTION OF HARD X-RAYS FROM TYCHO'S SUPERNOVA REMNANT: EVIDENCE FOR TITANIUM-44

    SciTech Connect

    Troja, E.; Baumgartner, W.; Markwardt, C.; Barthelmy, S.; Gehrels, N.; Segreto, A.; La Parola, V.; Cusumano, G.; Hartmann, D.

    2014-12-10

    We report Swift/Burst Alert Telescope survey observations of the Tycho's supernova remnant, performed over a period of 104 months since the mission's launch. The remnant is detected with high significance (>10σ) below 50 keV. We detect significant hard X-ray emission in the 60-85 keV band, above the continuum level predicted by a simple synchrotron model. The location of the observed excess is consistent with line emission from radioactive titanium-44, so far reported only for Type II supernova explosions. We discuss the implications of these results in the context of the galactic supernova rate, and nucleosynthesis in Type Ia supernova.

  10. Assessment of the Quality of Newly Formed Bone around Titanium Alloy Implants by Using X-Ray Photoelectron Spectroscopy.

    PubMed

    Nakada, Hiroshi; Sakae, Toshiro; Tanimoto, Yasuhiro; Teranishi, Mari; Kato, Takao; Watanabe, Takehiro; Saeki, Hiroyuki; Kawai, Yasuhiko; Legeros, Racquel Z

    2012-01-01

    The aim of this study was to evaluate differences in bones quality between newly formed bone and cortical bone formed around titanium alloy implants by using X-ray photoelectron spectroscopy. As a result of narrow scan measurement at 4 weeks, the newly formed bone of C1s, P2p, O1s, and Ca2p were observed at a different peak range and strength compared with a cortical bone. At 8 weeks, the peak range and strength of newly formed bone were similar to those of cortical bone at C1s, P2p, and Ca2p, but not O1s. The results from this analysis indicate that the peaks and quantities of each element of newly formed bone were similar to those of cortical bone at 8 weeks, suggestive of a strong physicochemical resemblance. PMID:22778740

  11. Energy dispersive X-ray analysis of titanium dioxide nanoparticle distribution after intravenous and subcutaneous injection in mice.

    PubMed

    Patri, Anil; Umbreit, Thomas; Zheng, J; Nagashima, K; Goering, Peter; Francke-Carroll, Sabine; Gordon, Edward; Weaver, James; Miller, Terry; Sadrieh, Nakissa; McNeil, Scott; Stratmeyer, Mel

    2009-11-01

    In an effort to understand the disposition and toxicokinetics of nanoscale materials, we used EDS (energy dispersive X-ray spectroscopy) to detect and map the distribution of titanium dioxide (TiO2) in tissue sections from mice following either subcutaneous (s.c.) or intravenous (i.v.) injection. TiO2 nanoparticles were administered at a dose of 560 mg/kg (i.v.) or 5600 mg/kg (s.c.) to Balb/c female mice on two consecutive days. Tissues (liver, kidney, lung, heart, spleen, and brain) were examined by light microscopy, TEM (transmission electron microscopy), SEM (scanning electron microscopy), and EDS following necropsy one day after treatment. Particle agglomerates were detected by light microscopy in all tissues examined, EDS microanalysis was used to confirm that these tissues contained elemental titanium and oxygen. The TEM micrographs and EDS spectra of the aggregates were compared with in vitro measurements of TiO2 nanoparticle injection solution (i.e., in water). The nanoparticles were also characterized using dynamic light scattering in water, 10 mM NaCl, and phosphate buffered saline (PBS). In low ionic strength solvents (water and 10 mM NaCl), the TiO2 particles had average hydrodynamic diameters ranging from 114-122 nm. In PBS, however, the average diameter increases to 1-2 microm, likely due to aggregation analogous to that observed in tissue by TEM and EDS. This investigation demonstrates the suitability of energy dispersive X-ray spectroscopy (EDS) for detection of nanoparticle aggregates in tissues and shows that disposition of TiO2 nanoparticles depends on the route of administration (i.v. or s.c.). PMID:19626582

  12. Cage Destruction in Metal-Fullerene Clusters

    SciTech Connect

    Tast, F.; Malinowski, N.; Frank, S.; Heinebrodt, M.; Billas, I.M.; Martin, T.P.

    1996-10-01

    Mass spectrometric studies on free clusters composed of single fullerene molecules and transition metal atoms (C{sub 60}{ital M}{sub {ital x}} and C{sub 70}{ital M}{sub {ital x}}; {ital x}=0.150, {ital M}{element_of}{l_brace}Ti,V,Nb,Ta{r_brace}) reveal that they undergo a laser induced transformation from metal-fullerene clusters to metal carbide and metallo-carbohedrene clusters. Two types of fragmentation behavior are observed. Fullerenes doped with titanium or vanadium seem to be stable at low laser intensities, whereas tantalum and niobium severely destabilize the fullerene cage. Photofragmentation spectra of preselected C{sub 60}Ta{sub {ital x}} indicate that the C{sub 60} cage is destroyed for {ital x}{ge}3. {copyright} {ital 1996 The American Physical Society.}

  13. High energy X-ray diffraction study of a dental ceramics–titanium functional gradient material prepared by field assisted sintering technique

    SciTech Connect

    Witte, K.; Bodnar, W.; Schell, N.; Lang, H.; Burkel, E.

    2014-09-15

    A functional gradient material with eleven layers composed of a dental ceramics and titanium was successfully consolidated using field assisted sintering technique in a two-step sintering process. High energy X-ray diffraction studies on the gradient were performed at High Energy Material Science beamline at Desy in Hamburg. Phase composition, crystal unit edges and lattice mismatch along the gradient were determined applying Rietveld refinement procedure. Phase analysis revealed that the main crystalline phase present in the gradient is α-Ti. Crystallinity increases stepwisely along the gradient with a decreasing increment between every next layer, following rather the weight fraction of titanium. The crystal unit edge a of titanium remains approximately constant with a value of 2.9686(1) Å, while c is reduced with increasing amount of titanium. In the layer with pure titanium the crystal unit edge c is constant with a value of 4.7174(2) Å. The lattice mismatch leading to an internal stress was calculated over the whole gradient. It was found that the maximal internal stress in titanium embedded in the studied gradient is significantly smaller than its yield strength, which implies that the structure of titanium along the whole gradient is mechanically stable. - Highlights: • High energy XRD studies of dental ceramics–Ti gradient material consolidated by FAST. • Phase composition, crystallinity and lattice parameters are determined. • Crystallinity increases stepwisely along the gradient following weight fraction of Ti. • Lattice mismatch leading to internal stress is calculated over the whole gradient. • Internal stress in α-Ti embedded in the gradient is smaller than its yield strength.

  14. Surface change in titanium subhydride between 25 and 700/sup 0/C studied by Auger electron spectroscopy and x-ray photoelectron spectroscopy

    SciTech Connect

    Wang, P.S.; Carlson, R.S.; Wittberg, T.N.

    1982-07-09

    The surface sensitive spectroscopic techniques of Auger electron spectroscopy (AES) and x-ray photoelectron spectroscopy (XPS) have been applied to the study of the oxide dissolution of titanium and titanium subhydride. In an earlier study using AES, it was shown that the rate of oxygen dissolution into titanium increased sharply at approx. 350/sup 0/C. These data correlated well with physical property measurements that indicated an exothermic reaction was occurring at these temperatures which corresponded to the reaction of free Ti with atmospheric oxygen. In the present study the work has been expanded to include studies of TiH/sub x/ (x = 1.15, 1.62). It has been found that dissolution of the native oxide on titanium subhydride occurs at a temperature substantially higher (approx. 500/sup 0/C) than that required for titanium. It appears that the outward diffusion of hydrogen is inhibiting the inward diffusion of oxygen on the sub-hydride samples at temperatures below 500/sup 0/C.

  15. High-Resolution Soft X-Ray Spectral Analysis in the CK Region of Titanium Carbide (TiC) using the DV-X alpha Molecular Orbital Method

    SciTech Connect

    Shimomura, Kenta; Muramatsu, Yasuji; Denlinger, Jonathan D.; Gullikson, Eric M.

    2008-10-31

    We used the DV-X alpha method to analyze the high-resolution soft X-ray emission and absorption spectra in the CK region of titanium carbide (TiC). The spectral profiles of the X-ray emission and absorption can be ssuscfucelly reproduced by the occupied and unoccupied density of states (DOS ), respectively, in the C2p orbitals of the center carbon atoms in a Ti62C63 cluster model, suggesting that the center carbon atom in a large cluster model expanded to the cubic-structured 53 (= 125) atoms provides sufficient DOS for the X-ray spectral analysis of rock-salt structured metal carbides.

  16. X-ray photoemission spectromicroscopy of titanium silicide formation in patterned microstructures

    SciTech Connect

    Singh, S.; Solak, H.; Cerrina, F.

    1997-04-01

    Titanium silicide has the lowest resistivity of all the refractory metal silicides and has good thermal stability as well as excellent compatibility with Al metallization. It is used as an intermediate buffer layer between W vias and the Si substrate to provide good electrical contact in ULSI technology, whose submicron patterned features form the basis of the integrated circuits of today and tomorrow, in the self aligned silicide (salicide) formation process. TiSi{sub 2} exists in two phases: a metastable C49 base-centered orthorhombic phase with specific resistivity of 60-90 {mu}{Omega}-cm that is formed at a lower temperature (formation anneal) and the stable 12-15 {mu}{Omega}-cm resistivity face-centered orthorhombic C54 phase into which C49 is transformed with a higher temperature (conversion anneal) step. C54 is clearly the target for low resistivity VLSI interconnects. However, it has been observed that when dimensions shrink below 1/mic (or when the Ti thickness drops below several hundred angstroms), the transformation of C49 into C54 is inhibited and agglomeration often occurs in fine lines at high temperatures. This results in a rise in resistivity due to incomplete transformation to C54 and because of discontinuities in the interconnect line resulting from agglomeration. Spectromicroscopy is an appropriate tool to study the evolution of the TiSi2 formation process because of its high resolution chemical imaging ability which can detect bonding changes even in the absence of changes in the relative amounts of species and because of the capability of studying thick {open_quotes}as is{close_quotes} industrial samples.

  17. John Cage Discusses Fluxus.

    ERIC Educational Resources Information Center

    Snyder, Ellsworth

    1992-01-01

    Presents an informal discussion with composer John Cage which includes his response to George Maciunas' work, his recollections of Marcel Duchamp, the complex relationship between inelegant material and revealing works of art, neo-Dada and neo-Fluxus, Wittgenstein and the artist's ultimate responsibility to initiate a change in the viewer or…

  18. Mandrel replication for hard x-ray optics using titanium nitride

    NASA Astrophysics Data System (ADS)

    Romaine, S.; Boike, J.; Bruni, R.; Engelhaupt, D.; Gorenstein, P.; Gubarev, M.; Ramsey, B.

    2009-08-01

    X-ray astronomy grazing incidence telescopes use the principle of nested shells to maximize the collecting area. Some of the more recent missions, such as XMM-Newton, have used an electroformed nickel replication process to fabricate the mirror shells. We have been developing coatings to simplify and improve this electroforming process. This paper discusses our most recent results from studies using TiN as a mandrel hardcoat in the electroforming process of fabricating nickel shell optics. The results indicate that nickel replicas separate easily from the TiN coated mandrel, and little (if any) degradation of the mandrel occurs after more than 20 replications. AFM characterization of the mandrel and replica surfaces is shown. Preliminary results are also included from studies which use this same process to replicate multilayer coatings; these results indicate no change in the multilayer stack after separation from the mandrel.

  19. Endohedral dynamics of push-pull rotor-functionalized cages.

    PubMed

    Krick, Marcel; Holstein, Julian; Würtele, Christian; Clever, Guido H

    2016-08-16

    A series of [Pd2L4] coordination cages featuring endohedral functionalities in central backbone positions was synthesized. Although attached via C[double bond, length as m-dash]C double bonds, the substituents behave as molecular rotors. This is explained by their pronounced donor-acceptor character which lowers rotational barriers and allows for electronic control over the spinning rates inside the cage. The dynamic behaviour of the free ligands, assembled cages and host-guest complexes is compared with the aid of NMR experiments, X-ray structure analysis and molecular modelling. PMID:27484435

  20. Role of Cages in Revision Arthroplasty of the Acetabulum.

    PubMed

    Mäkinen, Tatu J; Kuzyk, Paul; Safir, Oleg A; Backstein, David; Gross, Allan E

    2016-02-01

    ➤ The outcome of acetabular revision is heavily influenced by the degree of associated bone loss.➤ Uncemented hemispherical acetabular components can be used in the majority of acetabular revisions, although occasionally the degree of bone loss precludes the stability of the hemispherical component at the correct anatomic level or there is minimal bleeding host bone left for biologic fixation.➤ Massive acetabular bone loss resulting in the need for bone grafts or highly porous augments involving more than half of the acetabulum is one of the main indications for the use of cages.➤ The cup-cage reconstruction is based on bone-grafting the deficient acetabulum and securing a hemispherical, highly porous metal component with multiple screws to bridge the discontinuity and off-loading the hemispherical component with a titanium cage spanning from ischium to ilium.➤ In addition to managing pelvic discontinuities, the cup-cage construct can also be used in hips without discontinuity as the hemispherical, highly porous metal component is used to restore bone stock.➤ In situations in which there is not enough bleeding host bone to secure a hemispherical component, a highly porous metal augment can be used to address the osseous deficiency. The augment is also protected with a cage to assist bone ingrowth. PMID:26842414

  1. Porous Organic Cages for Sulfur Hexafluoride Separation.

    PubMed

    Hasell, Tom; Miklitz, Marcin; Stephenson, Andrew; Little, Marc A; Chong, Samantha Y; Clowes, Rob; Chen, Linjiang; Holden, Daniel; Tribello, Gareth A; Jelfs, Kim E; Cooper, Andrew I

    2016-02-10

    A series of porous organic cages is examined for the selective adsorption of sulfur hexafluoride (SF6) over nitrogen. Despite lacking any metal sites, a porous cage, CC3, shows the highest SF6/N2 selectivity reported for any material at ambient temperature and pressure, which translates to real separations in a gas breakthrough column. The SF6 uptake of these materials is considerably higher than would be expected from the static pore structures. The location of SF6 within these materials is elucidated by X-ray crystallography, and it is shown that cooperative diffusion and structural rearrangements in these molecular crystals can rationalize their superior SF6/N2 selectivity. PMID:26757885

  2. Chemical effects on the K{beta}{sup ''} and K{beta}{sub 2,5} x-ray lines of titanium and its compounds

    SciTech Connect

    Mandic, Luka; Fazinic, Stjepko; Jaksic, Milko

    2009-10-15

    High-resolution K{beta} x-ray spectra induced by 2 MeV protons in thick Ti, TiO, Ti{sub 2}O{sub 3}, TiO{sub 2}, MgTiO{sub 3}, FeTiO{sub 3}, TiC, TiN, and TiB{sub 2} targets were measured using a wavelength dispersive spectrometer combined with a position-sensitive detector. The intensities and energies of the K{beta}{sub 2,5} and K{beta}{sup ''} lines relative to the K{beta}{sub 1,3} line were extracted. The influence of self-absorption in thick targets was investigated using related x-ray-absorption near-edge-structure spectra that are available in the literature to extract mass absorption coefficients close to the K absorption edge. The correlation of the relative position of the K{beta}{sub 2,5} line with a titanium formal oxidation state in oxide compounds confirmed that the oxidation state of Ti in FeTiO{sub 3} is probably a mixture of Ti III and Ti IV states, which has been recently reported by other authors using different methods. The strengths of the K{beta}{sub 2,5} and K{beta}{sup ''} transition probabilities per titanium-ligand pair were found to decrease exponentially as the average titanium-ligand bond distance increased, which is similar to results obtained for various compounds with vanadium or manganese as the central 3d metal atoms.

  3. The Cage-Busting Teacher

    ERIC Educational Resources Information Center

    Hess, Frederick M.

    2015-01-01

    "The Cage-Busting Teacher" adopts the logic of "Cage-Busting Leadership" and applies it to the unique challenges and opportunities of classroom teachers. Detailed, accessible, and thoroughly engaging, it uncovers the many ways in which teachers can break out of familiar constraints in order to influence school and classroom…

  4. Building a better Faraday cage

    NASA Astrophysics Data System (ADS)

    MartinAlfven; Wright, David; skocpol; Rounce, Graham; Richfield, Jon; W, Nick; wheelsonfire

    2015-11-01

    In reply to the physicsworld.com news article “Are Faraday cages less effective than previously thought?” (15 September, http://ow.ly/SfklO), about a study that indicated, based on mathematical modelling, that conducting wire-mesh cages may not be as good at excluding electromagnetic radiation as is commonly assumed.

  5. Characterization of a hybrid target multi-keV x-ray source by a multi-parameter statistical analysis of titanium K-shell emission

    DOE PAGESBeta

    Primout, M.; Babonneau, D.; Jacquet, L.; Gilleron, F.; Peyrusse, O.; Fournier, K. B.; Marrs, R.; May, M. J.; Heeter, R. F.; Wallace, R. J.

    2015-11-10

    We studied the titanium K-shell emission spectra from multi-keV x-ray source experiments with hybrid targets on the OMEGA laser facility. Using the collisional-radiative TRANSPEC code, dedicated to K-shell spectroscopy, we reproduced the main features of the detailed spectra measured with the time-resolved MSPEC spectrometer. We developed a general method to infer the Ne, Te and Ti characteristics of the target plasma from the spectral analysis (ratio of integrated Lyman-α to Helium-α in-band emission and the peak amplitude of individual line ratios) of the multi-keV x-ray emission. Finally, these thermodynamic conditions are compared to those calculated independently by the radiation-hydrodynamics transportmore » code FCI2.« less

  6. Characterization of a hybrid target multi-keV x-ray source by a multi-parameter statistical analysis of titanium K-shell emission

    SciTech Connect

    Primout, M.; Babonneau, D.; Jacquet, L.; Gilleron, F.; Peyrusse, O.; Fournier, K. B.; Marrs, R.; May, M. J.; Heeter, R. F.; Wallace, R. J.

    2015-11-10

    We studied the titanium K-shell emission spectra from multi-keV x-ray source experiments with hybrid targets on the OMEGA laser facility. Using the collisional-radiative TRANSPEC code, dedicated to K-shell spectroscopy, we reproduced the main features of the detailed spectra measured with the time-resolved MSPEC spectrometer. We developed a general method to infer the Ne, Te and Ti characteristics of the target plasma from the spectral analysis (ratio of integrated Lyman-α to Helium-α in-band emission and the peak amplitude of individual line ratios) of the multi-keV x-ray emission. Finally, these thermodynamic conditions are compared to those calculated independently by the radiation-hydrodynamics transport code FCI2.

  7. Characterization of a hybrid target multi-keV x-ray source by a multi-parameter statistical analysis of titanium K-shell emission

    NASA Astrophysics Data System (ADS)

    Primout, M.; Babonneau, D.; Jacquet, L.; Gilleron, F.; Peyrusse, O.; Fournier, K. B.; Marrs, R.; May, M. J.; Heeter, R. F.; Wallace, R. J.

    2016-03-01

    We have studied the titanium K-shell emission spectra from multi-keV x-ray source experiments with hybrid targets on the OMEGA laser facility. Using the collisional-radiative TRANSPEC code, dedicated to K-shell spectroscopy, we reproduced the main features of the detailed spectra measured with the time-resolved MSPEC spectrometer. We have developed a general method to infer the Ne, Te and Ti characteristics of the target plasma from the spectral analysis (ratio of integrated Lyman-α to Helium-α in-band emission and the peak amplitude of individual line ratios) of the multi-keV x-ray emission. These thermodynamic conditions are compared to those calculated independently by the radiation-hydrodynamics transport code FCI2.

  8. Caged Protein Prenyltransferase Substrates: Tools for Understanding Protein Prenylation

    SciTech Connect

    DeGraw, Amanda J.; Hast, Michael A.; Xu, Juhua; Mullen, Daniel; Beese, Lorena S.; Barany, George; Distefano, Mark D.

    2010-11-15

    Originally designed to block the prenylation of oncogenic Ras, inhibitors of protein farnesyltransferase currently in preclinical and clinical trials are showing efficacy in cancers with normal Ras. Blocking protein prenylation has also shown promise in the treatment of malaria, Chagas disease and progeria syndrome. A better understanding of the mechanism, targets and in vivo consequences of protein prenylation are needed to elucidate the mode of action of current PFTase (Protein Farnesyltransferase) inhibitors and to create more potent and selective compounds. Caged enzyme substrates are useful tools for understanding enzyme mechanism and biological function. Reported here is the synthesis and characterization of caged substrates of PFTase. The caged isoprenoid diphosphates are poor substrates prior to photolysis. The caged CAAX peptide is a true catalytically caged substrate of PFTase in that it is to not a substrate, yet is able to bind to the enzyme as established by inhibition studies and X-ray crystallography. Irradiation of the caged molecules with 350 nm light readily releases their cognate substrate and their photolysis products are benign. These properties highlight the utility of those analogs towards a variety of in vitro and in vivo applications.

  9. Immobilization of two organometallic complexes into a single cage to construct protein-based microcompartments.

    PubMed

    Maity, Basudev; Fukumori, Kazuki; Abe, Satoshi; Ueno, Takafumi

    2016-04-01

    Natural protein-based microcompartments containing multiple enzymes promote cascade reactions within cells. We use the apo-ferritin protein cage to mimic such biocompartments by immobilizing two organometallic Ir and Pd complexes into the single protein cage. Precise locations of the metals and their accumulation mechanism were studied by X-ray crystallography. PMID:27021005

  10. Titanium 2013

    USGS Publications Warehouse

    2014-01-01

    Titanium is the ninth most abundant element in the earth's crust and can be found in nearly all rocks and sediments. It is a lithophile element with a strong affinity for oxygen and is not found as a pure metal in nature. Titanium was first isolated as a pure metal in 1910, but it was not until 1948 that the metal was produced commercially using the Kroll process (named after its developer, William Kroll) to reduce titanium tetrachloride with magnesium to produce titanium metal.

  11. Position and flux stabilization of X-ray beams produced by double-crystal monochromators for EXAFS scans at the titanium K-edge.

    PubMed

    van Silfhout, Roelof; Kachatkou, Anton; Groppo, Elena; Lamberti, Carlo; Bras, Wim

    2014-03-01

    The simultaneous and active feedback stabilization of X-ray beam position and monochromatic beam flux during EXAFS scans at the titanium K-edge as produced by a double-crystal monochromator beamline is reported. The feedback is generated using two independent feedback loops using separate beam flux and position measurements. The flux is stabilized using a fast extremum-searching algorithm that is insensitive to changes in the synchrotron ring current and energy-dependent monochromator output. Corrections of beam height are made using an innovative transmissive beam position monitor instrument. The efficacy of the feedback stabilization method is demonstrated by comparing the measurements of EXAFS spectra on inhomogeneous diluted Ti-containing samples with and without feedback applied. PMID:24562562

  12. Process for synthesizing titanium carbide, titanium nitride and titanium carbonitride

    DOEpatents

    Koc, R.; Glatzmaier, G.C.

    1995-05-23

    A process is disclosed for synthesizing titanium carbide, titanium nitride or titanium carbonitride. The process comprises placing particles of titanium, a titanium salt or titanium dioxide within a vessel and providing a carbon-containing atmosphere within the vessel. The vessel is heated to a pyrolysis temperature sufficient to pyrolyze the carbon to thereby coat the particles with a carbon coating. Thereafter, the carbon-coated particles are heated in an inert atmosphere to produce titanium carbide, or in a nitrogen atmosphere to produce titanium nitride or titanium carbonitride, with the heating being of a temperature and time sufficient to produce a substantially complete solid solution.

  13. Process for synthesizing titanium carbide, titanium nitride and titanium carbonitride

    DOEpatents

    Koc, Rasit; Glatzmaier, Gregory C.

    1995-01-01

    A process for synthesizing titanium carbide, titanium nitride or titanium carbonitride. The process comprises placing particles of titanium, a titanium salt or titanium dioxide within a vessel and providing a carbon-containing atmosphere within the vessel. The vessel is heated to a pyrolysis temperature sufficient to pyrolyze the carbon to thereby coat the particles with a carbon coating. Thereafter, the carbon-coated particles are heated in an inert atmosphere to produce titanium carbide, or in a nitrogen atmosphere to produce titanium nitride or titanium carbonitride, with the heating being of a temperature and time sufficient to produce a substantially complete solid solution.

  14. Furnished Cage System and Hen Well-Being: Comparative Effects of Furnished Cages and Battery Cages on Behavioral Exhibitions in White Leghorn Chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The battery cage system is being banned in the European Union before or by 2012; and the furnished cage system will be the only cage system allowed after 2012. This study was conducted to examine the different effects of caging systems, furnished cages vs. battery cages, on bird behaviors. One hundr...

  15. An evaluation of intra-cage ventilation in three animal caging systems.

    PubMed

    Keller, L S; White, W J; Snider, M T; Lang, C M

    1989-05-01

    Although temperature and relative humidity have been quantitated and their effects on research data studied, few studies have measured the air turnover rates at cage level. We evaluated the air distribution and air turnover rates in unoccupied shoe-box mouse cages, filter-top covered cages and shoe-box mouse cages housed in a flexible film isolator by using discontinuous gas chromatography/mass spectrometry and smoke. Results showed that air turnover was most rapid in the unoccupied shoe-box mouse cage and slowest in the filter-top covered cage. Placing mice in the filter-top covered cage did not significantly improve the air turnover rate. Although filter-top covered cages reduce cage-to-cage transmission of disease, the poor airflow observed within these cages could lead to a buildup of gaseous pollutants that may adversely affect the animal's health. PMID:2724925

  16. Spectral moments of fullerene cages

    NASA Astrophysics Data System (ADS)

    Zhang, Hongxing; Balasubramanian, K.

    Based on the symmetric method, analytical expression or recursive relations for the spectral moments of the C20, C24, C26, C28, C30, C32, C36, C38, C40, C42, C44, C50 and C60 fullerene cage clusters are obtained by factoring the original graphs and the corresponding characteristic polynomials into their smaller subgraphs and subpolynomials. We also give numerical results for the spectral moments. It is demonstrated that the symmetric method is feasible in enumerating the moments as well as factoring the characteristic polynomials for fullerene cages.

  17. Microclimate in two types of rat cages.

    PubMed

    Hirsjärvi, P A; Väliaho, T U

    1987-04-01

    The microclimate in two types of rat cages (a Makrolon type IV with a solid floor and a stainless steel cage with a wire mesh floor (five rats per cage)) placed in the same macro-environment was compared. The temperature, relative humidity and ammonia concentration in the cages were measured twice a day for 8 days. The cages were cleaned every 4 days. The greatest difference between the cage types was in the ammonia build-up. In Makrolon cages the ammonia concentration never reached 5 ppm, whereas in steel cages it showed a constant increase and already exceeded the threshold limit for man (25 ppm for 8 h per day) on the third day after cleaning. PMID:3599880

  18. Hybrid uranyl-carboxyphosphonate cage clusters.

    PubMed

    Adelani, Pius O; Ozga, Michael; Wallace, Christine M; Qiu, Jie; Szymanowski, Jennifer E S; Sigmon, Ginger E; Burns, Peter C

    2013-07-01

    Two new hybrid uranyl-carboxyphosphonate cage clusters built from uranyl peroxide units were crystallized from aqueous solution under ambient conditions in approximately two months. The clusters are built from uranyl hexagonal bipyramids and are connected by employing a secondary metal linker, the 2-carboxyphenylphosphonate ligand. The structure of cluster A is composed of a ten-membered uranyl polyhedral belt that is capped on either end of an elongated cage by five-membered rings of uranyl polyhedra. The structure of cluster B consists of 24 uranyl cations that are arranged into 6 four-membered rings of uranyl polyhedra. Four of the corresponding topological squares are fused together to form a sixteen-membered double uranyl pseudobelt that is capped on either end by 2 topological squares. Cluster A crystallizes over a wide pH range of 4.6-6.8, while cluster B was isolated under narrower pH range of 6.9-7.8. Studies of their fate in aqueous solution upon dissolution of crystals by electrospray ionization mass spectrometry (ESI-MS) and small-angle X-ray scattering (SAXS) provide evidence for their persistence in solution. The well-established characteristic fingerprint from the absorption spectra of the uranium(VI) cations disappears and becomes a nearly featureless peak; nonetheless, the two compounds fluoresce at room temperature. PMID:23763595

  19. DNA Cages with Icosahedral Symmetry in Bionanotechnology

    NASA Astrophysics Data System (ADS)

    Jonoska, Nataša; Taormina, Anne; Twarock, Reidun

    Blueprints for polyhedral cages with icosahedral symmetry made of circular DNA molecules are provided. The basic rule is that every edge of the cage is met twice in opposite directions by the DNA strand(s), and vertex junctions are realized by a set of admissible junction types. As nanocontainers for cargo storage and delivery, the icosidodecahedral cages are of special interest because they have the largest volume per surface ratio of all cages discussed here.

  20. Be a Cage-Buster

    ERIC Educational Resources Information Center

    Hess, Frederick M.

    2013-01-01

    "A cage-buster can't settle for ambiguity, banalities, or imprecision," writes well-known educator and author Rick Hess. "These things provide dark corners where all manners of ineptitude and excuse-making can hide." Hess suggests that leaders need to clearly define the problems they're trying to solve and open…

  1. A Mobile Phone Faraday Cage

    ERIC Educational Resources Information Center

    French, M. M. J.

    2011-01-01

    A Faraday cage is an interesting physical phenomenon where an electromagnetic wave can be excluded from a volume of space by enclosure with an electrically conducting material. The practical application of this in the classroom is to block the signal to a mobile phone by enclosing it in a metal can. The background of the physics behind this is…

  2. Mandibular reconstruction using autologous iliac bone and titanium mesh reinforced by laser welding for implant placement.

    PubMed

    Yamashita, Yoshio; Yamaguchi, Yoshimasa; Tsuji, Mitsuhiro; Shigematsu, Masahito; Goto, Masaaki

    2008-01-01

    Segmental mandibulectomy is a treatment option for benign and malignant neoplasms of the mandible. Although reconstructing the mandible of a patient with a missing segment is difficult, it is essential to improve the postoperative course of the patient. Mandibular reconstruction using titanium mesh is a useful technique for dental implant placement because the morphology of the mandible can be easily reproduced. However, fitting titanium mesh to the remaining mandible is not an easy task during surgery. The present report introduces a method in which a 3-dimensional skull model fabricated by means of stereolithography is prepared, based on computerized tomography (CT) scans, to construct a titanium mesh cage matching the shape of the mandible, preoperatively. Furthermore, the load-bearing area of the titanium mesh cage is reinforced by laser welding another layer of titanium mesh to reduce the incidence of metal fatigue during jaw movement. PMID:19216287

  3. Synthesis and reactivity of nitrogen nucleophiles-induced cage-rearrangement silsesquioxanes.

    PubMed

    Jaroentomeechai, Thapakorn; Yingsukkamol, Pa-Kwan; Phurat, Chuttree; Somsook, Ekasith; Osotchan, Tanakorn; Ervithayasuporn, Vuthichai

    2012-11-19

    Novel phthalimide and o-sulfobenzimide-functionalized silsesquioxanes were successfully synthesized via nucleophilic substitution reactions from octakis(3-chloropropyl)octasilsesquioxane. Surprisingly, the formation of deca- and dodecasilsesquioxanes cages was discovered during substitution with phthalimide, but only octasilsesquioxane maintained a cage in the o-sulfobenzimide substitution reaction. Moreover, we report the electronic effect of nitrogen nucleophiles to promote cage-rearrangement of inorganic silsesquioxane core for the first time. Structures of products were confirmed by (1)H, (13)C, and (29)Si NMR spectroscopy, ESI-MS analysis, and single-crystal X-ray diffraction. PMID:23134535

  4. Electronic cages for living cells.

    PubMed

    Al Saeed, Sarah; Bakewell, David J

    2015-08-01

    Design and construction of an electronic cage is described which enables real-time manipulation of live and dead eukaryotic cells. Non-uniform, radio frequency (RF) AC electric fields are used to enable translational and rotational movement of cells, known as dielectrophoresis (DEP) and electro-rotation (EROT), and distinguish their state as viable and non-viable. A concentric multilayered mathematical model, applicable for eukaryotic cells, is also developed, coded and implemented. The simulations predict three dielectric dispersions in the DEP and EROT spectra, though in practice the third is very small so that two are observed. The cage is part of a multi-staged project incorporating controller and DEP/EROT digital signal generator and image processing. PMID:26736401

  5. Inherent helicity in an extended tris-bipyridyl molecular cage

    SciTech Connect

    Perkins, D.; Lindoy, L.; Meehan, G.; Turner, P.

    2010-11-16

    A new molecular cage incorporating three bipyridyl units has been synthesised by a conventional multi-step procedure as well as, much more efficiently, by a Ni(II) template procedure; an X-ray structure of the nickel complex shows that it adopts an exo configuration of each of the bridgehead nitrogen lone pairs, the central metal ion acts to promote a triple helical twist that extends {approx}22 {angstrom} along the axial length of the molecule.

  6. Polymers containing borane or carborane cage compounds and related applications

    DOEpatents

    Bowen, III, Daniel E; Eastwood, Eric A

    2013-04-23

    Polymers comprising residues of cage compound monomers having at least one polyalkoxy silyl substituent are provided. The cage compound monomers are selected from borane cage compound monomers comprising at least 7 cage atoms and/or carborane cage compound monomers comprising 7 to 11 cage compound monomers. Such polymers can further comprise one or more reactive matrices and/or co-monomers covalently bound with the cage compound monomer residues. Articles of manufacture comprising such polymers are also disclosed.

  7. Inferior vena cava injury caused by an anteriorly migrated cage resulting in ligation: case report.

    PubMed

    Ariyoshi, Dai; Sano, Shigeo; Kawamura, Naohiro

    2016-03-01

    Anterior dislodgement of the transforaminal lumbar interbody fusion (TLIF) cage is one of the severe complications seen in this procedure, which may cause an intraoperative major vessel injury. The objective of this report is to present a rare case of inferior vena cava (IVC) injury during revision surgery for removal of the anteriorly migrated cage. The authors describe a case of 74-year-old woman with lumbar spinal canal stenosis and degenerative scoliosis. During the TLIF surgery, an inserted titanium cage at the L4-5 level dislodged anteriorly to the retroperitoneal space without massive bleeding from the disc space. In the second surgery, which was performed via an anterior retroperitoneal approach to remove the migrated cage, massive torrential bleeding occurred because of IVC injury. The laceration in the posterior wall of the IVC necessitated ligation of this vessel and both common iliac veins by a vascular surgeon. Postoperative edema of the lower extremities after ligation of the vessels was well tolerated, and the patient showed almost full recovery. For removal surgery of an anteriorly migrated cage, the surgeon should be well prepared for the risk of IVC injury, including requesting the attendance of a vascular surgeon. Ligation of the infrarenal IVC is an acceptable solution in irreparable IVC injury. PMID:26637062

  8. Lactobacillusassisted synthesis of titanium nanoparticles

    PubMed Central

    2007-01-01

    An eco-friendlylactobacillussp. (microbe) assisted synthesis of titanium nanoparticles is reported. The synthesis is performed at room temperature. X-ray and transmission electron microscopy analyses are performed to ascertain the formation of Ti nanoparticles. Individual nanoparticles as well as a number of aggregates almost spherical in shape having a size of 40–60 nm are found.

  9. Atomic scale X-ray studies of the electrical double layer structure at the rutile titanium dioxide (110)-aqueous interface

    NASA Astrophysics Data System (ADS)

    Zhang, Zhan

    When a metal oxide surface comes in contact with an aqueous solution, an electrical double layer (EDL) is formed at the interface. The EDL region greatly affects many natural and industrial processes. Efforts for more than a century have been put forward to understand the features of the EDL. However, with little atomic scale structural knowledge, the ability is very limited to test current competing models and further understand or predict EDL properties. In this work, the surface and the adsorbate structure at the rutile TiO 2 (110)-aqueous interface is probed with synchrotron based X-rays. Combining X-ray standing wave (XSW) imaging, which is direct and model independent, with tradition XSW triangulation, precise atom positions and absolute coverages are achieved. Crystal truncation rod (CTR) measurements yield the interfacial structure. It has been revealed the rutile (110) surface termination and structure and the specifically adsorbed ion locations while contacting with the bulk water. In the aqueous solution, both the bridging (BO) and the terminal oxygen (TO) rows are present and the surface undergoes minimal relaxations. An additional layer of water molecules with well-defined vertical and lateral positions are formed on top of surface oxygen groups. No more water structure is found farther away from the interface. The metal ions, including mono-, di-, and tri-valent ions, are all found to be 'inner sphere' adsorbates at the rutile (110)-aqueous interface. The adsorption location is primarily determined by the ion sizes. The larger ions, like Rb+, Sr 2+, and Y3+, take the tetradentate positions, which are of equal distances to the two TO and BO atoms. Small ions, like Zn 2+, are at the extended bulk Ti positions. With monovalent ions as the only background electrolytes at concentrations <1 mol/kg, we found that, the adsorbed divalent ions are independent of the type of the background electrolyte and the solution ionic strength; both Zn2+ and Sr2+ ions

  10. Cleaning Animals' Cages With Little Water

    NASA Technical Reports Server (NTRS)

    Harman, Benjamin J.

    1989-01-01

    Proposed freeze/thaw method for cleaning animals' cages requires little extra weight and consumes little power and water. Cleaning concept developed for maintaining experimental rat cages on extended space missions. Adaptable as well to similar use on Earth. Reduces cleaning time. Makes use of already available facilities such as refrigerator, glove box, and autoclave. Rat waste adheres to steel-wire-mesh floor of cage. Feces removed by loosening action of freezing-and-thawing process, followed by blast of air.

  11. Trp-Cage Folding on Organic Surfaces.

    PubMed

    Levine, Zachary A; Fischer, Sean A; Shea, Joan-Emma; Pfaendtner, Jim

    2015-08-20

    Trp-cage is an artificial miniprotein that is small, stable, and fast folding due to concerted hydrophobic shielding of a Trp residue by polyproline helices. Simulations have extensively characterized Trp-cage; however, the interactions of Trp-cage with organic surfaces (e.g., membranes) and their effect on protein conformation are largely unknown. To better understand these interactions we utilized a combination of replica-exchange molecular dynamics (REMD) and metadynamics (MetaD), to investigate Trp-cage folding on self-assembled monolayers (SAMs). We found that, with REMD and MetaD, Trp-cage strongly binds to neutral CH3 surfaces (-25kT) and moderately adsorbs to anionic COOH interfaces (-7.6kT), with hydrophobic interactions driving CH3 adhesion and electrostatic attractions driving COOH adhesion. Similar to solid-state surfaces, SAMs facilitate a number of intermediate Trp-cage conformations between folded and unfolded states. Regarding Trp-cage's aromatic groups in neutral CH3 systems, Tyr becomes oriented parallel to the surface in order to maximize hydrophobic interactions while Trp remains caged perpendicular to the surface; however, Trp can reorient itself parallel to the interface as the miniprotein more closely binds to the surface. In contrast, Tyr and Trp are both repelled from COOH surfaces, though the Trp-cage still adheres to the anionic interface via Lys and its N-terminated Asn residue. PMID:26207727

  12. Humidity and Cage and Bedding Temperatures in Unoccupied Static Mouse Caging after Steam Sterilization

    PubMed Central

    Ward, Gina M; Cole, Kelly; Faerber, Jennifer; Hankenson, F Claire

    2009-01-01

    Contemporary rodent caging and equipment often are sterilized by steam autoclaves prior to use in facilities. This work assessed the microenvironment of unoccupied static mouse cages after steam sterilization to determine when internal temperatures had cooled to levels appropriate for rodent housing. Polycarbonate static cages containing food and corncob bedding were stacked (10 rows × 7 columns) in duplicate (front and back; n = 140 cages) on a storage truck and autoclaved to 249 °F (121 °C). Cages (n = 6) were assessed to represent top, middle, and bottom rows and edges of columns. After cage sterilization, hygrothermometers were placed in cages to measure internal cage temperature (IT), bedding temperature (BT), and cage humidity (CH) every 10 min for 150 min. At time 0, there were no significant differences in averaged temperatures or humidity across cage locations: IT, 95.9 °F; BT, 109.8 °F; and CH, 84.1%. Over time, significant positional effects occurred. Whereas IT and BT for cages in the center row cooled more slowly than those on the bottom row, CH in top row cages decreased more quickly compared with other cages. After 150 min, the average measures overall were IT, 75.8 °F; BT, 77.9 °F; and CH, 82.4%. Comparison of the overall measures at 150 min with those of cages cooled overnight (IT, 72.4 °F; BT, 71.0 °F; and CH, 49%) and cages housing mice (IT, 72.2 °F; BT, 70.7 °F; and CH, 82%) indicated that a poststerilization cooling period of greater than 2.5 h was necessary to achieve permissible rodent housing conditions at our institution, particularly with corncob bedding autoclaved within the cage. PMID:19930826

  13. Preparation of titanium diboride powder

    DOEpatents

    Brynestad, Jorulf; Bamberger, Carlos E.

    1985-01-01

    Finely-divided titanium diboride or zirconium diboride powders are formed by reacting gaseous boron trichloride with a material selected from the group consisting of titanium powder, zirconium powder, titanium dichloride powder, titanium trichloride powder, and gaseous titanium trichloride.

  14. A polycaprolactone-tricalcium phosphate composite scaffold as an autograft-free spinal fusion cage in a sheep model.

    PubMed

    Li, Yi; Wu, Zhi-gang; Li, Xiao-kang; Guo, Zheng; Wu, Su-hua; Zhang, Yong-quan; Shi, Lei; Teoh, Swee-hin; Liu, Yu-chun; Zhang, Zhi-yong

    2014-07-01

    Titanium (Ti) based spinal fusion cages are frequently used in the clinics for the treatment of spinal degeneration and related diseases, however, their further clinical application is generally harassed by several drawbacks such as stress shielding, non-biodegradability and additional bone grafting procedure. Our earlier work has demonstrated the efficacy of a biodegradable macro-porous polycaprolactone-tricalcium phosphate (PCL-TCP) composite scaffold in promoting bony tissue ingrowth as well as its ability to sustain mechanical loads upon implantation into an orthotopic defect site. In this study, we investigated the use of PCL-TCP scaffold as an autograft-free spinal fusion cage in a preclinical sheep model over 12 months, and compared the fusion efficacy against Ti cages incorporated with autografts. Results showed that despite PCL-TCP scaffold as an autograft-free cage attaining a slower fusion rate at early stage (6 month), it achieved similar degree of spinal fusion efficacy as Ti cages aided with autograft at 12 month post-operation as evidenced by the radiographic and histological evaluation. PCL-TCP cages alone demonstrated better bone ingrowth with 2.6 fold higher bone/interspace ratio (B/I) and more homogeneous bone tissue distribution compared with that of the Ti cages (88.10  ±  3.63% vs. 33.74  ±  2.78%, p < 0.05) as seen from the histological and micro-CT analysis. Moreover, besides the bone tissue ingrowth, a quantitative approach was illustrated to accurately evaluate the osteointegration of fusion cage with surrounding bone tissue, and showed a 1.36 fold higher degree of osteointegration occurred in PCL-TCP cage group than Ti cage group (CS/PC: 79.31  ±  3.15% vs 58.44  ±  2.43%, p < 0.05). Furthermore, biomechanical analysis showed comparable mechanical strength of fused segments in both groups in terms of the range of motion and stiffness at 12 month (p > 0.05). The degradation profile of the PCL-TCP cages was noted

  15. Omega phase formation in titanium and titanium alloys

    SciTech Connect

    Gray, G.T. III; Morris, C.E.; Lawson, A.C.

    1992-05-01

    Although the response of titanium alloys to dynamic loading is receiving increased attention in the literature (particularly in the area of shear-band formation), a more limited experimental database exists concerning the detailed structure/property relationships of titanium alloys subjected to shock loading. In this study, preliminary results concerning the influence of alloy chemistry on the property of omega-phase formation and its structure in three titanium alloys are presented. The influence of shock-wave deformation on the phase stability and substructure evolution of high-purity (low-interstitial) titanium, A-70 (3700 ppm oxygen) titanium, and Ti-6Al-4V were probed utilizing real-time velocity interferometry (VISAR) and ``soft`` shock-recovery techniques. VISAR wave profiles of shock-loaded high-purity titanium revealed the omega-phase pressure-induced transition to occur at approximately 10.4 GPa. Wave profile measurements on A-70 Ti shocked to pressures up to 35 GPa and Ti-6Al-4V shocked to pressures up to 25 GPa exhibited no evidence of a three-wave structure indicative of a pressure-induced phase transition. Neutron and X-ray diffractometry and TEM analysis confirmed the presence of retained {omega}-phase in the electrolytic-Ti and the absence of {omega}-phase in the shock-recovered A-70 Ti and Ti-6Al-4V. Suppression of the {alpha}-{omega} phase transition in A-70 Ti, containing a high interstitial oxygen content, is seen to simultaneously correlate with suppression of deformation twinning. Neutron diffraction was used to measure the in-situ bulk lattice constants and volume fraction of the {alpha} and {omega} phases in the recovered high-purity titanium samples that were shock loaded. The influence of alloy content on the kinetics of formation/retention of {omega}-phase and substructure evolution is discussed and contrasted in light of previous literature studies.

  16. Characterisation of titanium-titanium boride composites processed by powder metallurgy techniques

    SciTech Connect

    Selva Kumar, M.; Chandrasekar, P.; Chandramohan, P.; Mohanraj, M.

    2012-11-15

    In this work, a detailed characterisation of titanium-titanium boride composites processed by three powder metallurgy techniques, namely, hot isostatic pressing, spark plasma sintering and vacuum sintering, was conducted. Two composites with different volume percents of titanium boride reinforcement were used for the investigation. One was titanium with 20% titanium boride, and the other was titanium with 40% titanium boride (by volume). Characterisation was performed using X-ray diffraction, electron probe micro analysis - energy dispersive spectroscopy and wavelength dispersive spectroscopy, image analysis and scanning electron microscopy. The characterisation results confirm the completion of the titanium boride reaction. The results reveal the presence of titanium boride reinforcement in different morphologies such as needle-shaped whiskers, short agglomerated whiskers and fine plates. The paper also discusses how mechanical properties such as microhardness, elastic modulus and Poisson's ratio are influenced by the processing techniques as well as the volume fraction of the titanium boride reinforcement. - Highlights: Black-Right-Pointing-Pointer Ti-TiB composites were processed by HIP, SPS and vacuum sintering. Black-Right-Pointing-Pointer The completion of Ti-TiB{sub 2} reaction was confirmed by XRD, SEM and EPMA studies. Black-Right-Pointing-Pointer Hardness and elastic properties of Ti-TiB composites were discussed. Black-Right-Pointing-Pointer Processing techniques were compared with respect to their microstructure.

  17. COATING ALTERNATIVES GUIDE (CAGE) USER'S GUIDE

    EPA Science Inventory

    The guide provides instructions for using the Coating Alternatives GuidE (CAGE) software program, version 1.0. It assumes that the user is familiar with the fundamentals of operating an IBM-compatible personal computer (PC) under the Microsoft disk operating system (MS-DOS). CAGE...

  18. High-temperature bearing-cage materials

    NASA Technical Reports Server (NTRS)

    Anderson, W. J.; Zaretsky, E. V.

    1968-01-01

    Evaluation tests conducted at temperatures of 500 and 700 degrees F reveal that S-Monel and AISI M-1 steel are suitable as high temperature cage materials for precision bearings. The area of the wear scar in the cage pocket that developed during the test was used as the measure of wear.

  19. 50 CFR 648.75 - Cage identification.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... are issued, or if rendered null and void in accordance with 15 CFR part 904. (d) Return. Tags that... Clam and Ocean Quahog Fisheries § 648.75 Cage identification. Except as provided in § 648.76, the... clams and ocean quahogs: (a) Tagging. Before offloading, all cages that contain surfclams or...

  20. Geomechanics of fracture caging in wellbores

    NASA Astrophysics Data System (ADS)

    Weijermars, Ruud; Zhang, Xi; Schultz-Ela, Dan

    2013-06-01

    This study highlights the occurrence of so-called `fracture cages' around underbalanced wellbores, where fractures cannot propagate outwards due to unfavourable principal stress orientations. The existence of such cages is demonstrated here by independent analytical and numerical methods. We explain the fracture caging mechanism and pinpoint the physical parameters and conditions for its control. This new insight has great practical relevance for the effectiveness and safety of drilling operations in general, and hydraulic fracturing in particular. Fracture caging runaway poses a hazard for drilling operations in overpressured formations. Recognition of the fracture caging mechanism also opens up new opportunities for controlled engineering of its effects by the manipulation of the Frac number in wells in order to bring more precision in the fracking process of tight formations.

  1. Lumbar interbody expanding cage. A preliminary study on an animal model.

    PubMed

    Manunta, M L; Careddu, G M; Masala, G; Columbano, N; Doria, C; Crissantu, L; Sanna Passino, E

    2008-01-01

    Interbody fusion devices are used in human medicine for treating degenerative diseases of the spine. Currently, there is not a universally accepted assessment tool for determining fusion, and the definitive criteria for diagnosing a successful interbody fusion remain controversial. The aim of this study was to describe microscopic and helical computed tomography (CT) imaging in the assessment of lumbar interbody fusion using cylindrical threaded titanium expanding cage in sheep. One cylindrical threaded expanding titanium cage (Proconcept--SA, Orange, France) was inserted through a transperitoneal approach after radical discectomy and packed with cancellous bone autograft in five adult sheep. The subjects were euthanatized after three, six, 12, 18 and 24 months. CT images revealed lumbar fusion at 12 months post operation, whereas microscopic evaluations indicated the presence of lumbar fusion at 18 months. CT and histological grades were the same in 65% of the cases observed. There were not a significant difference between CT, histological and micro radiographic grades. Helical CT scanning can be considered to be a suitable method for the monitoring of lumbar fusion as it enables observation of the deposition of bony bridging within the cage. PMID:18704248

  2. Holographic photolysis of caged neurotransmitters

    PubMed Central

    Lutz, Christoph; Otis, Thomas S.; DeSars, Vincent; Charpak, Serge; DiGregorio, David A.; Emiliani, Valentina

    2009-01-01

    Stimulation of light-sensitive chemical probes has become a powerful tool for the study of dynamic signaling processes in living tissue. Classically, this approach has been constrained by limitations of lens–based and point-scanning illumination systems. Here we describe a novel microscope configuration that incorporates a nematic liquid crystal spatial light modulator (LC-SLM) to generate holographic patterns of illumination. This microscope can produce illumination spots of variable size and number and patterns shaped to precisely match user-defined elements in a specimen. Using holographic illumination to photolyse caged glutamate in brain slices, we demonstrate that shaped excitation on segments of neuronal dendrites and simultaneous, multi-spot excitation of different dendrites enables precise spatial and rapid temporal control of glutamate receptor activation. By allowing the excitation volume shape to be tailored precisely, the holographic microscope provides an extremely flexible method for activation of various photosensitive proteins and small molecules. PMID:19160517

  3. Biomechanical effects of polyaxial pedicle screw fixation on the lumbosacral segments with an anterior interbody cage support

    PubMed Central

    Chen, Shih-Hao; Mo Lin, Ruey; Chen, Hsiang-Ho; Tsai, Kai-Jow

    2007-01-01

    Background Lumbosacral fusion is a relatively common procedure that is used in the management of an unstable spine. The anterior interbody cage has been involved to enhance the stability of a pedicle screw construct used at the lumbosacral junction. Biomechanical differences between polyaxial and monoaxial pedicle screws linked with various rod contours were investigated to analyze the respective effects on overall construct stiffness, cage strain, rod strain, and contact ratios at the vertebra-cage junction. Methods A synthetic model composed of two ultrahigh molecular weight polyethylene blocks was used with four titanium pedicle screws (two in each block) and two rods fixation to build the spinal construct along with an anterior interbody cage support. For each pair of the construct fixed with polyaxial or monoaxial screws, the linked rods were set at four configurations to simulate 0°, 7°, 14°, and 21° lordosis on the sagittal plane, and a compressive load of 300 N was applied. Strain gauges were attached to the posterior surface of the cage and to the central area of the left connecting rod. Also, the contact area between the block and the cage was measured using prescale Fuji super low pressure film for compression, flexion, lateral bending and torsion tests. Results Our main findings in the experiments with an anterior interbody cage support are as follows: 1) large segmental lordosis can decrease the stiffness of monoaxial pedicle screws constructs; 2) polyaxial screws rather than monoaxial screws combined with the cage fixation provide higher compression and flexion stiffness in 21° segmental lordosis; 3) polyaxial screws enhance the contact surface of the cage in 21° segmental lordosis. Conclusion Polyaxial screws system used in conjunction with anterior cage support yields higher contact ratio, compression and flexion stiffness of spinal constructs than monoaxial screws system does in the same model when the spinal segment is set at large lordotic

  4. Ultraviolet laser treatment of titanium surface

    NASA Astrophysics Data System (ADS)

    Balchev, Ivaylo; Minkovski, Nikolai; Dimitrov, Krasimir; Shipochka, Maria; Barbucha, Robert

    2016-02-01

    Interaction of a third harmonic of DPSS laser, wavelength 355 nm and pulse duration of 30 ns with titanium wafers was studied. It was investigated the structure of laser ablated titanium surface, depending on the laser beam scanning speed, and laser pulse frequency. The titanium surface modification was studied by scanning electron microscopy (SEM) and XPS (X- ray Photoelectron Spectroscopy). Nanosecond irradiation with ultraviolet light of Ti plate led to the formation of high porous granular structures consisting of agglomerated micro- and submicro- particles.

  5. Interfacial reactions between titanium and borate glass

    SciTech Connect

    Brow, R.K.; Saha, S.K.; Goldstein, J.I.

    1992-12-31

    Interfacial reactions between melts of several borate glasses and titanium have been investigated by analytical scanning electron microscopy (SEM) and x-ray photoelectron spectroscopy (XPS). A thin titanium boride interfacial layer is detected by XPS after short (30 minutes) thermal treatments. ASEM analyses after longer thermal treatments (8--120 hours) reveal boron-rich interfacial layers and boride precipitates in the Ti side of the interface.

  6. Protein Folding Simulation of Mutant Go Models of the Wild-Type Trp-cage Protein

    NASA Astrophysics Data System (ADS)

    Linhananta, Apichart; Liu, Junmin

    2008-03-01

    For the past three decades, Go models of protein folding have played important roles in the understanding of how proteins fold from random conformations to their unique native structures. Unfortunately Go models reliance on known NMR or x-ray structures to construct Go interaction potentials severely limit their predictive powers. In this work, we introduce a novel method for constructing Go interaction potentials of mutant proteins based on Go interaction potentials of wild type proteins. As a template we employ the all-atom Go model of the 20-residue Trp-cage protein (A. Linhananta, J. Boer and I. MacKay, J. Chem. Phys., 2005, 122, 114901) as the wild type Go model. Trp-cage mutants are constructed by replacing a Trp-cage residue with a different residue. In particular the Pro-12 residue of the Trp-cage is substituted by Trp-12 to produce the Trp2-cage mutant, whose native structure is not yet known. Monte Carlo simulations, using CHARMM force fields, are performed to determine the ground-state structure mutant. The resulting mutant structures are used to construct the Go interaction potential of the Trp2-cage mutant Go model.

  7. Active cage model of glassy dynamics.

    PubMed

    Fodor, Étienne; Hayakawa, Hisao; Visco, Paolo; van Wijland, Frédéric

    2016-07-01

    We build up a phenomenological picture in terms of the effective dynamics of a tracer confined in a cage experiencing random hops to capture some characteristics of glassy systems. This minimal description exhibits scale invariance properties for the small-displacement distribution that echo experimental observations. We predict the existence of exponential tails as a crossover between two Gaussian regimes. Moreover, we demonstrate that the onset of glassy behavior is controlled only by two dimensionless numbers: the number of hops occurring during the relaxation of the particle within a local cage and the ratio of the hopping length to the cage size. PMID:27575182

  8. Enhanced kinetic stability of [Pd2L4](4+) cages through ligand substitution.

    PubMed

    Preston, Dan; McNeill, Samantha M; Lewis, James E M; Giles, Gregory I; Crowley, James D

    2016-05-10

    There is considerable interest in exploiting metallosupramolecular cages as drug delivery vectors. Recently, we developed a [Pd2L4](4+) cage capable of binding two molecules of cisplatin. Unfortunately, this first generation cage was rapidly decomposed by common biologically relevant nucleophiles. In an effort to improve the kinetic stability of these cage architectures here we report the synthesis of two amino substituted tripyridyl 2,6-bis(pyridin-3-ylethynyl)pyridine () ligands (with amino groups either in the 2-() or 3-() positions of the terminal pyridines) and their respective [Pd2()4](4+) cages. These systems have been characterised by (1)H, (13)C and DOSY NMR spectroscopies, high resolution electrospray mass spectrometry, elemental analysis and, in one case, by X-ray crystallography. It was established, using model palladium(ii) N-heterocyclic carbene (NHC) probe complexes, that the amino substituted compounds were stronger donor ligands than the parent system ( > > ). Competition experiments with a range of nucleophiles showed that these substitutions lead to more kinetically robust cage architectures, with [Pd2()4](4+) proving the most stable. Biological testing on the three ligands and cages against A549 and MDA-MB-231 cell lines showed that only [Pd2()4](4+) exhibited any appreciable cytotoxicity, with a modest IC50 of 36.4 ± 1.9 μM against the MDA-MB-231 cell line. Unfortunately, the increase in kinetic stability of the [Pd2()4](4+) cages was accompanied by loss of cisplatin-binding ability. PMID:27074828

  9. Opportunities in the electrowinning of molten titanium from titanium dioxide

    NASA Astrophysics Data System (ADS)

    van Vuuren, D. S.; Engelbrecht, A. D.; Hadley, T. D.

    2005-10-01

    The value chain of titanium products shows that the difference between the cost of titanium ingot and titanium dioxide is about 9/kg titanium. In contrast, the price of aluminum, which is produced in a similar way, is only about 1.7/kg. Electrowinning of molten titanium from titanium dioxide is therefore believed to have significant potential to reduce the cost of titanium products. The process is hampered by the high operating temperatures and sophisticated materials of construction required; the high affinity of titanium for carbon, oxygen, and nitrogen; and physical and chemical properties of the different titanium oxide species when reducing titanium from Ti4+ to metallic titanium.

  10. Atomically flat Ge buffer layers and alternating shutter growth of CaGe2 for large area germanane

    NASA Astrophysics Data System (ADS)

    Xu, Jinsong; Katoch, Jyoti; Ahmed, Adam; Pinchuk, Igor; Williams, Robert; McComb, David; Kawakami, Roland

    Germanane (GeH), which is converted from CaGe2 by soaking in HCl acid, has recently attracted interest because of its novel properties, such as large band gap (1.56eV), spin orbit coupling and predictions of high mobility (18000 cm2/Vs). Previously CaGe2 was successfully grown on Ge(111) substrates by molecular beam epitaxy (MBE) growth. But there were cracks between µm-sized islands, which is not desirable for scientific study and application, and limits the material quality. By growing atomically flat Ge buffer layers and using alternating shutter MBE growth, we are able to grow crack-free, large area films of CaGe2 films. Reflection high energy electron diffraction (RHEED) patterns of Ge buffer layer and CaGe2 indicates high quality two dimensional surfaces, which is further confirmed by atomic force microscopy (AFM), showing atomically flat and uniform Ge buffer layer and CaGe2. The appearance of Laue oscillation in X-ray diffraction (XRD) and Kiessig fringes in X-ray reflectivity (XRR) proves the uniformity of CaGe2 film and the smoothness of the interface. The high quality of CaGe2 film makes it promising to explore novel properties of GeH. Funded by NSF MRSEC DMR-1420451.

  11. Encapsulation of Semiconducting Polymers in Vault Protein Cages

    SciTech Connect

    Ng, B.C.; Yu, M.; Gopal, A.; Rome, L.H.; Monbouquette, H.G.; Tolbert, S.H.

    2009-05-22

    We demonstrate that a semiconducting polymer [poly(2-methoxy-5-propyloxy sulfonate phenylene vinylene), MPS-PPV] can be encapsulated inside recombinant, self-assembling protein nanocapsules called 'vaults'. Polymer incorporation into these nanosized protein cages, found naturally at {approx}10,000 copies per human cell, was confirmed by fluorescence spectroscopy and small-angle X-ray scattering. Although vault cellular functions and gating mechanisms remain unknown, their large internal volume and natural prevalence within the human body suggests they could be used as carriers for therapeutics and medical imaging reagents. This study provides the groundwork for the use of vaults in encapsulation and delivery applications.

  12. Titanium Coating of the Boston Keratoprosthesis

    PubMed Central

    Salvador-Culla, Borja; Jeong, Kyung Jae; Kolovou, Paraskevi Evi; Chiang, Homer H.; Chodosh, James; Dohlman, Claes H.; Kohane, Daniel S.

    2016-01-01

    Purpose We tested the feasibility of using titanium to enhance adhesion of the Boston Keratoprosthesis (B-KPro), ultimately to decrease the risk of implant-associated complications. Methods Cylindrical rods were made of poly(methyl methacrylate) (PMMA), PMMA coated with titanium dioxide (TiO2) over a layer of polydopamine (PMMATiO2), smooth (Ti) and sandblasted (TiSB) titanium, and titanium treated with oxygen plasma (Tiox and TiSBox). Topography and surface chemistry were analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). Adhesion force between rods and porcine corneas was measured ex vivo. Titanium sleeves, smooth and sandblasted, were inserted around the stem of the B-KPro and implanted in rabbits. Tissue adhesion to the stem was assessed and compared to an unmodified B-Kpro after 1 month. Results X-ray photoelectron spectroscopy demonstrated successful deposition of TiO2 on polydopamine-coated PMMA. Oxygen plasma treatment did not change the XPS spectra of titanium rods (Ti and TiSB), although it increased their hydrophilicity. The materials did not show cell toxicity. After 14 days of incubation, PMMATiO2, smooth titanium treated with oxygen plasma (Tiox), and sandblasted titanium rods (TiSB, TiSBox) showed significantly higher adhesion forces than PMMA ex vivo. In vivo, the use of a TiSB sleeve around the stem of the B-KPro induced a significant increase in tissue adhesion compared to a Ti sleeve or bare PMMA. Conclusions Sandblasted titanium sleeves greatly enhanced adherence of the B-KPro to the rabbit cornea. This approach may improve adhesion with the donor cornea in humans as well. Translational Relevance This approach may improve adhesion with donor corneas in humans. PMID:27152247

  13. 30 CFR 56.19070 - Closing cage doors or gates.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Closing cage doors or gates. 56.19070 Section... Hoisting Hoisting Procedures § 56.19070 Closing cage doors or gates. Cage doors or gates shall be closed while persons are being hoisted; they shall not be opened until the cage has come to a stop....

  14. 30 CFR 56.19070 - Closing cage doors or gates.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Closing cage doors or gates. 56.19070 Section... Hoisting Hoisting Procedures § 56.19070 Closing cage doors or gates. Cage doors or gates shall be closed while persons are being hoisted; they shall not be opened until the cage has come to a stop....

  15. 30 CFR 57.19070 - Closing cage doors or gates.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Closing cage doors or gates. 57.19070 Section... Hoisting Hoisting Procedures § 57.19070 Closing cage doors or gates. Cage doors or gates shall be closed while persons are being hoisted; they shall not be opened until the cage has come to a stop....

  16. 30 CFR 57.19070 - Closing cage doors or gates.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Closing cage doors or gates. 57.19070 Section... Hoisting Hoisting Procedures § 57.19070 Closing cage doors or gates. Cage doors or gates shall be closed while persons are being hoisted; they shall not be opened until the cage has come to a stop....

  17. 30 CFR 56.19070 - Closing cage doors or gates.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Closing cage doors or gates. 56.19070 Section... Hoisting Hoisting Procedures § 56.19070 Closing cage doors or gates. Cage doors or gates shall be closed while persons are being hoisted; they shall not be opened until the cage has come to a stop....

  18. 30 CFR 57.19070 - Closing cage doors or gates.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Closing cage doors or gates. 57.19070 Section... Hoisting Hoisting Procedures § 57.19070 Closing cage doors or gates. Cage doors or gates shall be closed while persons are being hoisted; they shall not be opened until the cage has come to a stop....

  19. 30 CFR 57.19070 - Closing cage doors or gates.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Closing cage doors or gates. 57.19070 Section... Hoisting Hoisting Procedures § 57.19070 Closing cage doors or gates. Cage doors or gates shall be closed while persons are being hoisted; they shall not be opened until the cage has come to a stop....

  20. 30 CFR 57.19070 - Closing cage doors or gates.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Closing cage doors or gates. 57.19070 Section... Hoisting Hoisting Procedures § 57.19070 Closing cage doors or gates. Cage doors or gates shall be closed while persons are being hoisted; they shall not be opened until the cage has come to a stop....

  1. 30 CFR 56.19070 - Closing cage doors or gates.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Closing cage doors or gates. 56.19070 Section... Hoisting Hoisting Procedures § 56.19070 Closing cage doors or gates. Cage doors or gates shall be closed while persons are being hoisted; they shall not be opened until the cage has come to a stop....

  2. 30 CFR 56.19070 - Closing cage doors or gates.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Closing cage doors or gates. 56.19070 Section... Hoisting Hoisting Procedures § 56.19070 Closing cage doors or gates. Cage doors or gates shall be closed while persons are being hoisted; they shall not be opened until the cage has come to a stop....

  3. Compositions containing borane or carborane cage compounds and related applications

    SciTech Connect

    Bowen, III, Daniel E; Eastwood, Eric A

    2014-11-11

    Compositions comprising a polymer-containing matrix and a filler comprising a cage compound selected from borane cage compounds, carborane cage compounds, metal complexes thereof, residues thereof, mixtures thereof, and/or agglomerations thereof, where the cage compound is not covalently bound to the matrix polymer. Methods of making and applications for using such compositions are also disclosed.

  4. Compositions containing borane or carborane cage compounds and related applications

    SciTech Connect

    Bowen, III, Daniel E.; Eastwood, Eric A.

    2015-09-15

    Compositions comprising a polymer-containing matrix and a filler comprising a cage compound selected from borane cage compounds, carborane cage compounds, metal complexes thereof, residues thereof, mixtures thereof, and/or agglomerations thereof, where the cage compound is not covalently bound to the matrix polymer. Methods of making and applications for using such compositions are also disclosed.

  5. 48 CFR 204.7204 - Maintenance of the CAGE file.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Maintenance of the CAGE... Maintenance of the CAGE file. (a) DLIS will accept written requests for changes to CAGE files, other than name...) Submit requests for changes to CAGE files on DD Form 2051, or electronic equivalent, to—Defense...

  6. Compositions containing borane or carborane cage compounds and related applications

    DOEpatents

    Bowen, III, Daniel E; Eastwood, Eric A

    2013-05-28

    Compositions comprising a polymer-containing matrix and a filler comprising a cage compound selected from borane cage compounds, carborane cage compounds, metal complexes thereof, residues thereof, mixtures thereof, and/or agglomerations thereof, where the cage compound is not covalently bound to the matrix polymer. Methods of making and applications for using such compositions are also disclosed.

  7. Maintenance of a Drosophila melanogaster Population Cage

    PubMed Central

    Caravaca, Juan Manuel; Lei, Elissa P.

    2016-01-01

    Large quantities of DNA, RNA, proteins and other cellular components are often required for biochemistry and molecular biology experiments. The short life cycle of Drosophila enables collection of large quantities of material from embryos, larvae, pupae and adult flies, in a synchronized way, at a low economic cost. A major strategy for propagating large numbers of flies is the use of a fly population cage. This useful and common tool in the Drososphila community is an efficient way to regularly produce milligrams to tens of grams of embryos, depending on uniformity of developmental stage desired. While a population cage can be time consuming to set up, maintaining a cage over months takes much less time and enables rapid collection of biological material in a short period. This paper describes a detailed and flexible protocol for the maintenance of a Drosophila melanogaster population cage, starting with 1.5 g of harvested material from the previous cycle. PMID:27023790

  8. 50 CFR 648.77 - Cage identification.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... fishing year for which they are issued, or if rendered null and void in accordance with 15 CFR part 904... Atlantic Surf Clam and Ocean Quahog Fisheries § 648.77 Cage identification. Except as provided in §...

  9. 50 CFR 648.77 - Cage identification.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... fishing year for which they are issued, or if rendered null and void in accordance with 15 CFR part 904... Atlantic Surf Clam and Ocean Quahog Fisheries § 648.77 Cage identification. Except as provided in §...

  10. 50 CFR 648.77 - Cage identification.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... fishing year for which they are issued, or if rendered null and void in accordance with 15 CFR part 904... Atlantic Surf Clam and Ocean Quahog Fisheries § 648.77 Cage identification. Except as provided in §...

  11. Dual-purpose laboratory cage/antenna

    NASA Technical Reports Server (NTRS)

    Lalande, B. H.

    1977-01-01

    Part of steel cage enclosing laboratory animals is used as an antenna to transmit biotelemetry over short distances. Receiving and signal processing equipment are located above ground potential to avoid transmission-path difficulties.

  12. Biocompatibility of Titanium

    NASA Astrophysics Data System (ADS)

    Namavar, Fereydoon; Sabirianov, Renat; Marton, Denes; Rubinstein, Alexander; Garvin, Kevin

    2012-02-01

    Titanium is the material of choice for orthopaedic applications because of its known biocompatibility. In order to enhance osteogenic properties of the Ti implants, it is necessary to understand the origin of its biocompatibility. We addresses the origin of Ti biocompatibility through (1) theoretical modeling, (2) the precise determination of Ti surface chemistry by X-ray photoelectron spectroscopy (XPS), (3) and the study of fibronectin adsorption as a function of Ti (near) surface chemistry by Enzyme-linked immunosorbent assay (ELISA). We compare the protein adsorption on Ti with the native oxide layer and the one coated by TiO2 in anatase phase using ion beam assisted deposition (IBAD). We show that the thin native sub-stoichiometric titanium oxide layer is crucial for biocompatibility of Ti surface. This is due to the enhancement of the non-specific adsorption of proteins which mediate cell adhesion. Improving the surface oxide quality, i.e. fabricating stoichiometric TiO2 (using IBAD) as well as nanoengineering the surface topology that matches its dimensions to that of adhesive proteins, is crucial for increased protein adsorption and, as a result, further increases biocompatibility of Ti implant materials.

  13. Cage Change Intervals for Opossums (Monodelphis domestica) in Individually Ventilated Cages

    PubMed Central

    Allison, Sarah O; Criley, Jennifer M; Kim, Ji Young; Goodly, Lyndon J

    2011-01-01

    The opossum Monodelphis domestica is the most commonly used marsupial in biomedical research. At our institution, these opossums are housed in polycarbonate (35.6 cm × 25.4 cm × 17.8 cm) individually ventilated cages. Previous studies of the cage microenvironment of rodents housed in individually ventilated cages have demonstrated that the cage-change frequency could be extended from 7 to 14 d, without detriment to the animals’ wellbeing. We sought to determine whether the cage change frequency for opossums housed in individually ventilated cages could be extended to 14 d. Opossums were placed into 3 experimental groups: singly housed males, singly housed females, and females housed with litters. The 14-d testing period was repeated twice, with temperature, relative humidity, and ammonia levels tested on days 0, 7, and 14. Acceptable ranges for the cage microenvironment were based on standards followed by our institution for housing rodents: temperature between 22 to 26 °C, relative humidity between 30% to 70%, and ammonia less than 25 ppm. Throughout both 14-d testing periods, temperature, relative humidity, and ammonia levels for singly housed male and singly housed female opossums were within acceptable ranges. However, ammonia levels exceeded the recommended 25 ppm on day 7 of both testing periods for female opossums housed with litters. In summary, the cage-change frequency for a singly housed opossum in an individually ventilated cage can be extended to 14 d. PMID:22330710

  14. Kinetically Trapped Tetrahedral Cages via Alkyne Metathesis.

    PubMed

    Lee, Semin; Yang, Anna; Moneypenny, Timothy P; Moore, Jeffrey S

    2016-02-24

    In dynamic covalent synthesis, kinetic traps are perceived as disadvantageous, hindering the system from reaching its thermodynamic equilibrium. Here we present the near-quantitative preparation of tetrahedral cages from simple tritopic precursors using alkyne metathesis. While the cages are the presumed thermodynamic sink, we experimentally demonstrate that the products no longer exchange their vertices once they have formed. The example reported here illustrates that kinetically trapped products may facilitate high yields of complex products from dynamic covalent synthesis. PMID:26854552

  15. Effect of alloying on the phase composition of titanium carbonitride-titanium nickelide alloys

    NASA Astrophysics Data System (ADS)

    Askarova, L. Kh.; Grigorov, I. G.; Ermakov, A. N.; Zainulin, Yu. G.; Nikitina, E. V.

    2015-08-01

    X-ray diffraction, electron microprobe analysis, electron microscopy, and chemical analysis are used to study the effect of alloying with zirconium, niobium, vanadium, and molybdenum on the phase composition of titanium carbonitride-titanium nickel cermets. It is shown that two-phase alloys containing alloyed titanium carbonitride and titanium nickelide can only be produced by alloying with zirconium. The addition of niobium, molybdenum, and vanadium leads to the formation of a third phase, namely, Nb z Ni, Mo(Ti,C), or V4Ni, in the alloy. A correlation between the phase composition of the alloys and the ratio of the energies of formation of titanium carbides and the carbides of alloying elements is found.

  16. Stand-alone LLIF Lateral Cage Migration: A Case Report.

    PubMed

    Towers, Wendy S; Kurtom, Khalid H

    2015-01-01

    Lateral approaches to the lumbar disc space have become popular in recent years with very few reported complications. We report on a rare case of a stand-alone cage migration. A 77-year-old female presented with a right L2-3 radiculopathy that was refractory to maximum medical management. This was secondary to foraminal compression at L2-3 and L3-4 due to degenerative disc disease and levoscoliosis, as well as Grade 1 spondylolisthesis at both levels. A left-sided approach lateral lumbar interbody fusion was performed at L2-3 and L3-4 using a lordotic polyetheretherketone (PEEK) graft (50 mm length x 18 mm width x 9 mm height) packed with demineralized bone matrix (DBM). A contralateral release of the annulus fibrosis was performed during the decompression prior to graft insertion. Postoperative anteroposterior and lateral x-ray imaging confirmed good position of interbody grafts, correction of scoliosis as well as spondylolisthesis, and restoration of disc height achieving foraminal indirect decompression. A routine postoperative x-ray at three months demonstrated asymptomatic ipsilateral cage migration at the L2-3 level with evidence of arthrodesis in the disc space. This was managed conservatively without further surgical intervention. Placement of a lateral plate or interbody intradiscal plating system in patients with scoliosis and significant coronal deformity is an option that can be considered to prevent this rare LLIF complication. Moreover, asymptomatic cage migration may be conservatively managed without reoperation. PMID:26623202

  17. Titanium hermetic seals

    DOEpatents

    Brow, Richard K.; Watkins, Randall D.

    1995-07-04

    Titanium is prenitrided by being heated in a nitrogen environment under conditions which give rise to the formation of a titanium-nitride surface layer on the titanium. Titanium thus prenitrided may be used in electrical components which are hermetically sealed using silicate glasses and standard glass sealing techniques. According to the method of the invention, alkali volatilization and formation of deleterious interfacial silicide are inhibited.

  18. Titanium hermetic seals

    DOEpatents

    Brow, Richard K.; Watkins, Randall D.

    1995-01-01

    Titanium is prenitrided by being heated in a nitrogen environment under conditions which give rise to the formation of a titanium-nitride surface layer on the titanium. Titanium thus prenitrided may be used in electrical components which are hermetically sealed using silicate glasses and standard glass sealing techniques. According to the method of the invention, alkali volatilization and formation of deleterious interfacial silicide are inhibited.

  19. Sealing glasses for titanium and titanium alloys

    DOEpatents

    Brow, R.K.; Watkins, R.D.

    1988-01-21

    Glass compositions containing CaO, Al/sub 2/O/sub 3/, B/sub 2/O/sub 3/, SrO and BaO of various combinations of mole % are provided. These compositions are capable of forming stable glass-to-metal seals with titanium and titanium alloys, for use in components such as seals for battery headers.

  20. Sealing glasses for titanium and titanium alloys

    DOEpatents

    Brow, Richard K.; Watkins, Randall D.

    1992-01-01

    Glass compositions containing CaO, Al.sub.2 O.sub.3, B.sub.2 O.sub.3, SrO and BaO of various combinations of mole % are provided. These compositions are capable of forming stable glass-to-metal seals with titanium and titanium alloys, for use in components such as seals for battery headers.

  1. Solid state and aqueous behavior of uranyl peroxide cage clusters

    NASA Astrophysics Data System (ADS)

    Pellegrini, Kristi Lynn

    Uranyl peroxide cage clusters include a large family of more than 50 published clusters of a variety of sizes, which can incorporate various ligands including pyrophosphate and oxalate. Previous studies have reported that uranyl clusters can be used as a method to separate uranium from a solid matrix, with potential applications in reprocessing of irradiated nuclear fuel. Because of the potential applications of these novel structures in an advanced nuclear fuel cycle and their likely presence in areas of contamination, it is important to understand their behavior in both solid state and aqueous systems, including complex environments where other ions are present. In this thesis, I examine the aqueous behavior of U24Pp 12, as well as aqueous cluster systems with added mono-, di-, and trivalent cations. The resulting solutions were analyzed using dynamic light scattering and ultra-small angle X-ray scattering to evaluate the species in solution. Precipitates of these systems were analyzed using powder X-ray diffraction, X-ray fluorescence spectrometry, and Raman spectroscopy. The results of these analyses demonstrate the importance of cation size, charge, and concentration of added cations on the aqueous behavior of uranium macroions. Specifically, aggregates of various sizes and shapes form rapidly upon addition of cations, and in some cases these aggregates appear to precipitate into an X-ray amorphous material that still contains U24Pp12 clusters. In addition, I probe aggregation of U24Pp12 and U60, another uranyl peroxide cage cluster, in mixed solvent water-alcohol systems. The aggregation of uranyl clusters in water-alcohol systems is a result of hydrogen bonding with polar organic molecules and the reduction of the dielectric constant of the system. Studies of aggregation of uranyl clusters also allow for comparison between the newer uranyl polyoxometalate family and century-old transition metal polyoxometalates. To complement the solution studies of uranyl

  2. UV photofunctionalization promotes nano-biomimetic apatite deposition on titanium

    PubMed Central

    Saita, Makiko; Ikeda, Takayuki; Yamada, Masahiro; Kimoto, Katsuhiko; Lee, Masaichi Chang-Il; Ogawa, Takahiro

    2016-01-01

    Background Although biomimetic apatite coating is a promising way to provide titanium with osteoconductivity, the efficiency and quality of deposition is often poor. Most titanium implants have microscale surface morphology, and an addition of nanoscale features while preserving the micromorphology may provide further biological benefit. Here, we examined the effect of ultraviolet (UV) light treatment of titanium, or photofunctionalization, on the efficacy of biomimetic apatite deposition on titanium and its biological capability. Methods and results Micro-roughed titanium disks were prepared by acid-etching with sulfuric acid. Micro-roughened disks with or without photofunctionalization (20-minute exposure to UV light) were immersed in simulated body fluid (SBF) for 1 or 5 days. Photofunctionalized titanium disks were superhydrophilic and did not form surface air bubbles when immersed in SBF, whereas non-photofunctionalized disks were hydrophobic and largely covered with air bubbles during immersion. An apatite-related signal was observed by X-ray diffraction on photofunctionalized titanium after 1 day of SBF immersion, which was equivalent to the one observed after 5 days of immersion of control titanium. Scanning electron microscopy revealed nodular apatite deposition in the valleys and at the inclines of micro-roughened structures without affecting the existing micro-configuration. Micro-roughened titanium and apatite-deposited titanium surfaces had similar roughness values. The attachment, spreading, settling, proliferation, and alkaline phosphate activity of bone marrow-derived osteoblasts were promoted on apatite-coated titanium with photofunctionalization. Conclusion UV-photofunctionalization of titanium enabled faster deposition of nanoscale biomimetic apatite, resulting in the improved biological capability compared to the similarly prepared apatite-deposited titanium without photofunctionalization. Photofunctionalization-assisted biomimetic apatite

  3. Phase composition and some properties of titanium carbonitride-titanium nickelide alloys with Al2O3 nanoparticles

    NASA Astrophysics Data System (ADS)

    Ermakov, A. N.; Misharina, I. V.; Grigorov, I. G.; Pushin, V. G.; Zainulin, Yu. G.

    2009-02-01

    The phase formation in and the microstructure of titanium carbonitride-titanium nickelide alloys with aluminum oxide Al2O3 nanopowder additions are studied by X-ray diffraction, electron-microscopic, and electron-probe microanalyses. The phase interaction is characterized by the redistribution of nonmetallic elements and aluminum between refractory and binding phases with the formation of a nonstoichiometric titanium-aluminum (Ti,Al)(C,N) carbonitride and a titanium-aluminum nickelide. The number of forming phases and their compositions are controlled by the kinetic parameters of the process.

  4. Temperature dependence of polyhedral cage volumes in clathrate hydrates

    USGS Publications Warehouse

    Chakoumakos, B.C.; Rawn, C.J.; Rondinone, A.J.; Stern, L.A.; Circone, S.; Kirby, S.H.; Ishii, Y.; Jones, C.Y.; Toby, B.H.

    2003-01-01

    The polyhedral cage volumes of structure I (sI) (carbon dioxide, methane, trimethylene oxide) and structure II (sII) (methane-ethane, propane, tetrahydrofuran, trimethylene oxide) hydrates are computed from atomic positions determined from neutron powder-diffraction data. The ideal structural formulas for sI and sII are, respectively, S2L6 ?? 46H2O and S16L???8 ?? 136H2O, where S denotes a polyhedral cage with 20 vertices, L a 24-cage, and L??? a 28-cage. The space-filling polyhedral cages are defined by the oxygen atoms of the hydrogen-bonded network of water molecules. Collectively, the mean cage volume ratio is 1.91 : 1.43 : 1 for the 28-cage : 24-cage : 20-cage, which correspond to equivalent sphere radii of 4.18, 3.79, and 3.37 A??, respectively. At 100 K, mean polyhedral volumes are 303.8, 227.8, and 158.8 A??3 for the 28-cage, 24-cage, and 20-cage, respectively. In general, the 20-cage volume for a sII is larger than that of a sI, although trimethylene oxide is an exception. The temperature dependence of the cage volumes reveals differences between apparently similar cages with similar occupants. In the case of trimethylene oxide hydrate, which forms both sI and sII, the 20-cages common to both structures contract quite differently. From 220 K, the sII 20-cage exhibits a smooth monotonic reduction in size, whereas the sI 20-cage initially expands upon cooling to 160 K, then contracts more rapidly to 10 K, and overall the sI 20-cage is larger than the sII 20-cage. The volumes of the large cages in both structures contract monotonically with decreasing temperature. These differences reflect reoriented motion of the trimethyelene oxide molecule in the 24-cage of sI, consistent with previous spectroscopic and calorimetric studies. For the 20-cages in methane hydrate (sI) and a mixed methane-ethane hydrate (sII), both containing methane as the guest molecule, the temperature dependence of the 20-cage volume in sII is much less than that in sI, but sII is overall

  5. Uranium pyrophosphate / methylenediphosphonate polyoxometalate cage clusters

    SciTech Connect

    Ling, Jie; Qiu, Jie; Sigmon, Ginger E.; Ward, Matt; Szymanowski, Jennifer E.S.; Burns, Peter C

    2010-09-29

    Despite potential applications in advanced nuclear energy systems, nanoscale control of uranium materials is in its infancy. In its hexavalent state, U occurs as (UO{sub 2}){sup 2+} uranyl ions that are coordinated by various ligands to give square, pentagonal, or hexagonal bipyramids. Creation and design of nanostructured uranyl materials requires interruption of the tendency of uranyl bipyramids to share equatorial edges to form infinite sheets that occur in extended structures. Where a bidentate peroxide group bridges uranyl bipyramids, the configuration is inherently bent, fostering formation of cage clusters. Here the bent configurations of four- and five-membered rings of uranyl peroxide hexagonal bipyramids are bridged by pyrophosphate or methylenediphosphonate, creating eight chemically complex cage clusters with specific topologies. Chemical complexity in such clusters provides opportunities for the tuning of cage sizes, pore sizes, and properties such as aqueous solubility. Several of these are topological derivatives of simpler clusters that contain only uranyl bipyramids, whereas others exhibit new topologies.

  6. Bicontinuous Nanoporous Frameworks: Caged Longevity for Enzymes.

    PubMed

    Bae, Jae-Sung; Jeon, Eunkyung; Moon, Su-Young; Oh, Wangsuk; Han, Sun-Young; Lee, Jeong Hun; Yang, Sung Yun; Kim, Dong-Myung; Park, Ji-Woong

    2016-09-12

    The preparation of bicontinuous nanoporous covalent frameworks, which are promising for caging active enzymes, is demonstrated. The frameworks have three- dimensionally continuous, hydrophilic pores with widths varying between 5 and 30 nm. Enzymes were infiltrated into the bicontinuous pore by applying a pressured enzyme solution. The new materials and methods allowed the amount of caged proteins to be controlled precisely. The resulting enzyme-loaded framework films could be recycled many times with nearly no loss of catalytic activity. Entropic trapping of proteins by a bicontinuous pore with the right size distribution is an unprecedented strategy toward facile in vitro utilization of biocatalysts. PMID:27513827

  7. Phosphonate Based High Nuclearity Magnetic Cages.

    PubMed

    Sheikh, Javeed Ahmad; Jena, Himanshu Sekhar; Clearfield, Abraham; Konar, Sanjit

    2016-06-21

    Transition metal based high nuclearity molecular magnetic cages are a very important class of compounds owing to their potential applications in fabricating new generation molecular magnets such as single molecular magnets, magnetic refrigerants, etc. Most of the reported polynuclear cages contain carboxylates or alkoxides as ligands. However, the binding ability of phosphonates with transition metal ions is stronger than the carboxylates or alkoxides. The presence of three oxygen donor sites enables phosphonates to bridge up to nine metal centers simultaneously. But very few phosphonate based transition metal cages were reported in the literature until recently, mainly because of synthetic difficulties, propensity to result in layered compounds, and also their poor crystalline properties. Accordingly, various synthetic strategies have been followed by several groups in order to overcome such synthetic difficulties. These strategies mainly include use of small preformed metal precursors, proper choice of coligands along with the phosphonate ligands, and use of sterically hindered bulky phosphonate ligands. Currently, the phosphonate system offers a library of high nuclearity transition metal and mixed metal (3d-4f) cages with aesthetically pleasing structures and interesting magnetic properties. This Account is in the form of a research landscape on our efforts to synthesize and characterize new types of phosphonate based high nuclearity paramagnetic transition metal cages. We quite often experienced synthetic difficulties with such versatile systems in assembling high nuclearity metal cages. Few methods have been emphasized for the self-assembly of phosphonate systems with suitable transition metal ions in achieving high nuclearity. We highlighted our journey from 2005 until today for phosphonate based high nuclearity transition metal cages with V(IV/V), Mn(II/III), Fe(III), Co(II), Ni(II), and Cu(II) metal ions and their magnetic properties. We observed that

  8. Hybrid Lanthanide-Actinide Peroxide Cage Clusters.

    PubMed

    Sigmon, Ginger E; Szymanowski, Jennifer E S; Carter, Korey P; Cahill, Christopher L; Burns, Peter C

    2016-03-21

    A cage cluster consisting of 31 uranyl and 9 Sm(3+) polyhedra self-assembles in an alkaline aqueous peroxide solution and crystallizes (U31Sm9). Trimers of Sm(3+) polyhedra are templated by μ3-η(2):η(2):η(2)-peroxide groups and link to oxo atoms of uranyl ions. Three such trimers link into a ring through uranyl hexagonal bipyramids, and these are attached through six polyhedra to a unit consisting of 21 uranyl hexagonal bipyramids to complete the cage. Luminescence spectra collected with an excitation wavelength of 420 nm reveal fine structure, which is not observed for a cluster containing only uranyl polyhedra. PMID:26923457

  9. Operative treatment of isthmic spondylolisthesis with posterior stabilization and ALIF. Cages versus autogenous bone grafts.

    PubMed

    Pankowski, Rafal; Smoczynski, Andrzej; Roclawski, Marek; Ceynowa, Marcin; Kloc, Wojciech; Wasilewski, Wojciech; Jende, Piotr; Liczbik, Wieslaw; Beldzinski, Piotr; Libionka, Witold; Pierzak, Olaf; Adamski, Stanislaw; Niedbala, Miroslaw

    2012-01-01

    In the following study the use of cages and autogenous bone grafts were compared in the operative treatment of isthmic spondylolisthesis with the posterior stabilization and Anterior Lumbosacral Interbody Fusion (ALIF). 55 patients were divided into two groups. Autogenous bone grafts were used in the first group (34 patients) and titanium interbody implants (cages) in the second group (21 patients). The mean follow up period in the first group was 8.6 years and 3.4 years in the second group. The radiological outcome was based upon the evaluation of the degree of spondylolisthesis, the angle of the lumbar lordosis, the height of the interbody space and intervertebral foramen and the evaluation of the spinal fusion. The objective clinical outcome assessment was based on Oswestry Disability Index. Subjective clinical evaluation was performed with the use of Visual Analog Pain Score (VAS) and the two questions concerning the evaluation of success of the operative treatment and a possible agreement to the following operation if necessary. The use of autogenous bone grafts alone in ALIF was related to the significant loss of achieved segmental spine anatomy restoration. The implantation of the cages prevented the loss of slippage correction, permanently reconstructed the anatomical conditions in the area of the operated spinal segment. PMID:22744517

  10. Stress enhanced diffusion of krypton ions in polycrystalline titanium

    SciTech Connect

    Nsengiyumva, S.; Raji, A. T.; Rivière, J. P.; Britton, D. T.; Härting, M.

    2014-07-14

    An experimental investigation on the mutual influence of pre-existing residual stress and point defect following ion implantation is presented. The study has been carried out using polycrystalline titanium samples energetically implanted with krypton ions at different fluences. Ion beam analysis was used to determine the concentration profile of the injected krypton ions, while synchrotron X-ray diffraction has been used for stress determination. Ion beam analysis and synchrotron X-ray diffraction stress profile measurements of the implanted titanium samples show a clear evidence of stress-enhanced diffusion of krypton ions in titanium. It is further observed that for the titanium samples implanted at low fluence, ion implantation modifies the pre-existing residual stress through the introduction of point and open volume defects. The stress fields resulting from the ion implantation act to drift the krypton inclusions towards the surface of titanium.

  11. Design and modeling of Faraday cages for substrate noise isolation

    NASA Astrophysics Data System (ADS)

    Wu, Joyce H.; del Alamo, Jesús A.

    2013-07-01

    A Faraday cage structure using through-substrate vias is an effective strategy to suppress substrate crosstalk, particularly at high frequencies. Faraday cages can reduce substrate noise by 32 dB at 10 GHz, and 26 dB at 50 GHz. We have developed lumped-element, equivalent circuit models of the Faraday cages and test structures to better understand the performance of the Faraday cages. These models compare well to measured results and show that the vias of the Faraday cage act as an RLC shunt to ground that draws substrate current. Designing a Faraday cage to achieve optimum isolation requires low via impedance and mitigation of via sidewall capacitance. The Faraday cage inductance is correlated to the number of vias and via spacing of the cage and can be optimized for the frequency of operation.

  12. Cage RACK ventilation options for laboratory animal facilities.

    PubMed

    Stakutis, Richard E

    2003-09-01

    Individually ventilated cage systems have become the method of choice for housing rodents. The author describes the various options for cage ventilation, from using supply and exhaust fans to directly connecting the racks to the building ventilation system. PMID:12966448

  13. CO chemisorption on the surfaces of the golden cages

    SciTech Connect

    Huang, Wei; Bulusu, Satya; Pal, R; Zeng, Xiao Cheng; Wang, Lai S

    2009-12-18

    We report a joint experimental and theoretical study of CO chemisorption on the golden cages. We find that the Au17- cage is highly robust and retains its cage structure in Au17-CO-. On the other hand, the Au16 - cage is transformed to a structure similar to Au17- upon the adsorption of CO. Au18 - is known to consist of two nearly degenerate structures, i.e., a cage and a pyramidal isomer, which coexist in the cluster beam. However, upon CO chemisorption only the cage isomer is observed while the pyramidal isomer no longer exists due to its less favorable interaction with CO, compared to the cage isomer. We find that inclusion of the spin-orbit effects is critical in yielding simulated spectra in quantitative agreement with the experimental data and providing unequivocal structural information and molecular insights into the chemical interactions between CO and the golden cages.

  14. Delineating the First Few Seconds of Supramolecular Self-Assembly of Mesostructured Titanium Oxide Thin Films through Time-Resolved Small Angle X-ray Scattering

    SciTech Connect

    Luca, Vittorio; Bertram, Willem K.; Sizgek, G. Devlet; Yang, Bin; Cookson, David

    2009-01-15

    The early stages of evaporation induced self-assembly of titanium oxide mesophases from a precursor solution containing TiCl{sub 4} and the Pluronic triblock copolymer F-127 in HCl-water-ethanol solution have been studied using time-resolved SAXS techniques. Two experimental protocols were used to conduct these experiments. In one of these, the precursor solution was pumped around a closed loop as solvent was allowed to evaporate at a constant humidity-controlled rate. In the second protocol, a film of precursor solution was measured periodically as it dried completely to a residue under a stream of dry air. This permitted the detailed monitoring of changes in solution chemistry as a function of the elimination of volatile components followed by the actual drying process itself. The SAXS data were modeled in terms of two Guinier radii for soft nanoparticles while a broad Gaussian feature in the scatter profiles was accounted for by particle-article scattering interference due to close packing. For the initial precursor solution, one Guinier radius was found to be about 17 {angstrom} while the other ranged from 4 to 11 {angstrom}. Changing the rate of evaporation affected the two radii differently with a more pronounced effect on the smaller particle size range. Analysis gave an interparticle distance in the range 55--80 {angstrom} for the initial precursor solution which decreased steadily at both of the humidities investigated as evaporation proceeded and the particle packing increased. These results represent the first attempts to monitor in a precise fashion the growth of nano building blocks during the initial stages of the self-assembly process of a titanium oxide mesophase.

  15. Chemical contamination of animal feeding systems: evaluation of two caging systems and standard cage-washing equipment.

    PubMed

    Fox, J G; Helfrich-Smith, M E

    1980-12-01

    Sodium fluorescein was added as a tracer to an ager gel diet which was fed for 5 day to 90 of 180 rats housed in two different polycarbonate caging systems, shoe-box cages and suspension solid-bottom cages. Cage racks, supplementary equipment, and case washer surfaces were analysed for fluorescein both before and after a complete wash and rinse cycle. Efficacy of washing was greater than 99% for both the inside and outside of the suspended cages and greater than 99% for the inside, but only 93% for the outside, of the shoe-box cages. The shoe-box cages, which were larger than the suspended cages, were spaced closer together on the washer rack, which may account for this variation in cleaning effectiveness. The cage washer surfaces and the water, which was recirculated during each cycle, also became contaminated with fluorescein. Strict adherence to proper cage-washing procedures and careful selection of cage design are important factors in controlling the potential for residual contamination of caging and cage-washing equipment. PMID:7464031

  16. Lactobacillus assisted synthesis of titanium nanoparticles

    NASA Astrophysics Data System (ADS)

    Prasad, K.; Jha, Anal K.; Kulkarni, A. R.

    2007-05-01

    An eco-friendly lactobacillus sp. (microbe) assisted synthesis of titanium nanoparticles is reported. The synthesis is performed at room temperature. X-ray and transmission electron microscopy analyses are performed to ascertain the formation of Ti nanoparticles. Individual nanoparticles as well as a number of aggregates almost spherical in shape having a size of 40 60 nm are found.

  17. Silicon nitride coating on titanium to enable titanium-ceramic bonding.

    PubMed

    Wang, R R; Welsch, G E; Monteiro, O

    1999-08-01

    Failures that occur in titanium-ceramic restorations are of concern to clinicians. The formation of poorly adhering oxide on titanium at dental porcelain sintering temperatures causes adherence problems between titanium and porcelain, which is the main limiting factor in the fabrication of titanium-ceramic restorations. To overcome this problem a 1-microm thick Si3N4 coating was applied to a titanium surface using a plasma-immersion implantation and deposition method. Such a coating serves as an oxygen diffusion barrier on titanium during the porcelain firings. The protective coating was characterized in the as-deposited condition and after thermal cycling. Cross sections of Ti/Si3N4-porcelain interface regions were examined by various electron microscopy methods and by energy dispersive analysis of X-rays to study the Si3N4 film's effectiveness in preventing titanium oxidation and in forming a bond with porcelain. The experiments have shown that this Si3N4 coating enables significant improvement in Ti-ceramic bonding. PMID:10380005

  18. Porous Organic Cage Thin Films and Molecular-Sieving Membranes.

    PubMed

    Song, Qilei; Jiang, Shan; Hasell, Tom; Liu, Ming; Sun, Shijing; Cheetham, Anthony K; Sivaniah, Easan; Cooper, Andrew I

    2016-04-01

    Porous organic cage molecules are fabricated into thin films and molecular-sieving membranes. Cage molecules are solution cast on various substrates to form amorphous thin films, with the structures tuned by tailoring the cage chemistry and processing conditions. For the first time, uniform and pinhole-free microporous cage thin films are formed and demonstrated as molecular-sieving membranes for selective gas separation. PMID:26800019

  19. Caged oligonucleotides for studying biological systems

    PubMed Central

    Ruble, Brittani K.; Yeldell, Sean B.; Dmochowski, Ivan J.

    2015-01-01

    Light-activated (“caged”) compounds have been widely employed for studying biological processes with high spatial and temporal control. In the past decade, several new approaches for caging the structure and function of DNA and RNA oligonucleotides have been developed. This review focuses on caged oligonucleotides that incorporate site-specifically one or two photocleavable linkers, whose photolysis yields oligonucleotides with dramatic structural and functional changes. This technique has been employed by our laboratory and others to photoregulate gene expression in cells and living organisms, typically using near UV-activated organic chromophores. To improve capabilities for in vivo studies, we harnessed the rich inorganic photochemistry of ruthenium bipyridyl complexes to synthesize Ru-caged morpholino antisense oligonucleotides that remain inactive in zebrafish embryos until uncaged with visible light. Expanding into new caged oligonucleotide applications, our lab has developed Transcriptome In Vivo Analysis (TIVA) technology, which provides the first noninvasive, unbiased method for isolating mRNA from single neurons in brain tissues. TIVA-isolated mRNA can be amplified and then analyzed using next-generation sequencing (RNA-seq). PMID:25865001

  20. Busting out of the Teacher Cage

    ERIC Educational Resources Information Center

    Hess, Frederick M.

    2015-01-01

    The author lays out guidelines and suggestions for how teachers can actually become policy leaders, taken from his book, "The Cage-Busting Teacher" (Harvard Education Press, 2015). Teachers serious about leadership can get the ear of policy makers by leveraging their positional and moral authority--though they may need to be persistent…

  1. An Easy Synthesis of Two Cage Hydrocarbons.

    ERIC Educational Resources Information Center

    Dong, Dao Cong

    1982-01-01

    Describes a simple, three-step synthesis of two cage molecules, birdcage hydrocarbon (VIII) and its homologue, the homobirdcage hydrocarbon IX. Indicates that all products are easily purified and formed in high yields in this activity suitable for advanced undergraduate laboratory courses. (Author/JN)

  2. Stabilizing a 22 karat nanogolden cage

    NASA Astrophysics Data System (ADS)

    Wang, Q.; Sun, Q.; Jena, P.

    2009-11-01

    Since the discovery of C60 fullerene, considerable efforts have been devoted to find other elements with similar hollow cage structures. However, search for hollow metallic cages with a diameter similar to that of C60 fullerene has been elusive. We describe a procedure for the rational design of metallic cages by suitably choosing their size, composition, and charge state. A 22 karat nanogolden cage with a diameter of about 8.5 Å and consisting of 12 Al and 20 Au atoms is found to be metastable, which can be stabilized by embedding a Mn4 cluster. In contrast to bulk Mn, which is antiferromagnetic, and isolated Mn4 cluster, which is ferromagnetic with a giant magnetic moment of 20μB, the Mn4@Al12Au20 endohedral complex exhibits magnetic bistability with 0μB and 14μB configurations being energetically nearly degenerate. These results, based on density functional theory, open the door to design a novel class of endohedral complexes with possible applications.

  3. Stabilizing a 22 karat nanogolden cage.

    PubMed

    Wang, Q; Sun, Q; Jena, P

    2009-11-28

    Since the discovery of C(60) fullerene, considerable efforts have been devoted to find other elements with similar hollow cage structures. However, search for hollow metallic cages with a diameter similar to that of C(60) fullerene has been elusive. We describe a procedure for the rational design of metallic cages by suitably choosing their size, composition, and charge state. A 22 karat nanogolden cage with a diameter of about 8.5 A and consisting of 12 Al and 20 Au atoms is found to be metastable, which can be stabilized by embedding a Mn(4) cluster. In contrast to bulk Mn, which is antiferromagnetic, and isolated Mn(4) cluster, which is ferromagnetic with a giant magnetic moment of 20mu(B), the Mn(4)@Al(12)Au(20) endohedral complex exhibits magnetic bistability with 0mu(B) and 14mu(B) configurations being energetically nearly degenerate. These results, based on density functional theory, open the door to design a novel class of endohedral complexes with possible applications. PMID:19947688

  4. 50 CFR 648.75 - Cage identification.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... in accordance with 15 CFR part 904. (d) Return. Tags that have been rendered null and void must be... Atlantic Surf Clam and Ocean Quahog Fisheries § 648.75 Cage identification. Link to an amendment published... requirements apply to all vessels issued a Federal fishing permit for surf clams and ocean quahogs: (a)...

  5. High-temperature in situ crystallographic observation of reversible gas sorption in impermeable organic cages.

    PubMed

    Baek, Seung Bin; Moon, Dohyun; Graf, Robert; Cho, Woo Jong; Park, Sung Woo; Yoon, Tae-Ung; Cho, Seung Joo; Hwang, In-Chul; Bae, Youn-Sang; Spiess, Hans W; Lee, Hee Cheon; Kim, Kwang S

    2015-11-17

    Crystallographic observation of adsorbed gas molecules is a highly difficult task due to their rapid motion. Here, we report the in situ single-crystal and synchrotron powder X-ray observations of reversible CO2 sorption processes in an apparently nonporous organic crystal under varying pressures at high temperatures. The host material is formed by hydrogen bond network between 1,3,5-tris-(4-carboxyphenyl)benzene (H3BTB) and N,N-dimethylformamide (DMF) and by π-π stacking between the H3BTB moieties. The material can be viewed as a well-ordered array of cages, which are tight packed with each other so that the cages are inaccessible from outside. Thus, the host is practically nonporous. Despite the absence of permanent pathways connecting the empty cages, they are permeable to CO2 at high temperatures due to thermally activated molecular gating, and the weakly confined CO2 molecules in the cages allow direct detection by in situ single-crystal X-ray diffraction at 323 K. Variable-temperature in situ synchrotron powder X-ray diffraction studies also show that the CO2 sorption is reversible and driven by temperature increase. Solid-state magic angle spinning NMR defines the interactions of CO2 with the organic framework and dynamic motion of CO2 in cages. The reversible sorption is attributed to the dynamic motion of the DMF molecules combined with the axial motions/angular fluctuations of CO2 (a series of transient opening/closing of compartments enabling CO2 molecule passage), as revealed from NMR and simulations. This temperature-driven transient molecular gating can store gaseous molecules in ordered arrays toward unique collective properties and release them for ready use. PMID:26578758

  6. High-temperature in situ crystallographic observation of reversible gas sorption in impermeable organic cages

    PubMed Central

    Baek, Seung Bin; Moon, Dohyun; Graf, Robert; Cho, Woo Jong; Park, Sung Woo; Yoon, Tae-Ung; Cho, Seung Joo; Hwang, In-Chul; Bae, Youn-Sang; Spiess, Hans W.; Lee, Hee Cheon; Kim, Kwang S.

    2015-01-01

    Crystallographic observation of adsorbed gas molecules is a highly difficult task due to their rapid motion. Here, we report the in situ single-crystal and synchrotron powder X-ray observations of reversible CO2 sorption processes in an apparently nonporous organic crystal under varying pressures at high temperatures. The host material is formed by hydrogen bond network between 1,3,5-tris-(4-carboxyphenyl)benzene (H3BTB) and N,N-dimethylformamide (DMF) and by π–π stacking between the H3BTB moieties. The material can be viewed as a well-ordered array of cages, which are tight packed with each other so that the cages are inaccessible from outside. Thus, the host is practically nonporous. Despite the absence of permanent pathways connecting the empty cages, they are permeable to CO2 at high temperatures due to thermally activated molecular gating, and the weakly confined CO2 molecules in the cages allow direct detection by in situ single-crystal X-ray diffraction at 323 K. Variable-temperature in situ synchrotron powder X-ray diffraction studies also show that the CO2 sorption is reversible and driven by temperature increase. Solid-state magic angle spinning NMR defines the interactions of CO2 with the organic framework and dynamic motion of CO2 in cages. The reversible sorption is attributed to the dynamic motion of the DMF molecules combined with the axial motions/angular fluctuations of CO2 (a series of transient opening/closing of compartments enabling CO2 molecule passage), as revealed from NMR and simulations. This temperature-driven transient molecular gating can store gaseous molecules in ordered arrays toward unique collective properties and release them for ready use. PMID:26578758

  7. 48 CFR 204.7202-1 - CAGE codes.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...-free 1-888-352-9333); (B) The on-line access to the CAGE file through the Defense Logistics Information System; (C) The on-line access to the Defense Logistics Agency (DLA) CAGE file through the DLA Network or....39-M, Federal Logistics Information System (FLIS) Procedures Manual, prescribe use of CAGE codes....

  8. 48 CFR 204.7204 - Maintenance of the CAGE file.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Maintenance of the CAGE... Maintenance of the CAGE file. (a) DLA Logistics Information Service will accept written requests for changes to CAGE files, other than name changes, from the following entities: (1) The entity identified by...

  9. Filtration effects due to bioassay cage design and screen type

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of bioassay cages in the efficacy assessment of specific compounds, application techniques and technologies is a common practice. There are a number of cage designs being used that range across a variety of cage shapes and sizes and mesh types. The objective of this work was to examine a r...

  10. 48 CFR 204.7204 - Maintenance of the CAGE file.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Maintenance of the CAGE... Maintenance of the CAGE file. (a) DLA Logistics Information Service will accept written requests for changes to CAGE files, other than name changes, from the following entities: (1) The entity identified by...

  11. 48 CFR 204.7204 - Maintenance of the CAGE file.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Maintenance of the CAGE... Maintenance of the CAGE file. (a) DLA Logistics Information Service will accept written requests for changes to CAGE files, other than name changes, from the following entities: (1) The entity identified by...

  12. 48 CFR 204.7204 - Maintenance of the CAGE file.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Maintenance of the CAGE... Maintenance of the CAGE file. (a) DLA Logistics Information Service will accept written requests for changes to CAGE files, other than name changes, from the following entities: (1) The entity identified by...

  13. Laser Gas Nitriding of Titanium and Titanium Alloys

    NASA Astrophysics Data System (ADS)

    Dai, J. J.; Hou, S. Q.

    Titanium and titanium alloys are widely used in many fields due to some of their characteristics such as light density, high strength, and excellent corrosion resistance. However, poor mechanical performances limit their practical applications. Laser gas nitriding is a promising method used to improve the surface properties of components. Recent developments on laser gas nitriding of titanium and titanium alloys are reviewed. The processing parameters have important effects on the resulting characteristics of titanium and titanium alloys. The resulting microstructure and properties of laser gas nitrided specimens are presented. The problems to be solved and the prospects in the field of laser gas nitriding of titanium and titanium alloys are discussed.

  14. Dichloromethane photodegradation using titanium catalysts

    SciTech Connect

    Tanguay, J.F.; Suib, S.L.; Coughlin, R.W. )

    1989-06-01

    The use of titanium dioxide and titanium aluminosilicates in the photocatalytic destruction of chlorinated hydrocarbons is investigated. Titanium-exchanged clays, titanium-pillared clays, and titanium dioxide in the amorphous, anatase, and rutile forms are used to photocatalytically degrade dichloromethane to hydrochloric acid and carbon dioxide. Bentonite clays pillared by titanium dioxide are observed to be more catalytically active than titanium-exchanged clays. Clays pillared by titanium aluminum polymeric cations display about the same catalytic activity as that of titanium-exchanged clays. The rutile form of titanium dioxide is the most active catalyst studied for the dichloromethane degradation reaction. The anatase form of titanium dioxide supported on carbon felt was also used as a catalyst. This material is about five times more active than titanium dioxide-pillared clays. Degradation of dichloromethane using any of these catalysts can be enhanced by oxygen enrichment of the reaction solution or by preirradiating the catalyst with light.

  15. CAGEd-oPOSSUM: motif enrichment analysis from CAGE-derived TSSs

    PubMed Central

    Arenillas, David J.; Forrest, Alistair R. R.; Kawaji, Hideya; Lassmann, Timo; Wasserman, Wyeth W.; Mathelier, Anthony

    2016-01-01

    With the emergence of large-scale Cap Analysis of Gene Expression (CAGE) datasets from individual labs and the FANTOM consortium, one can now analyze the cis-regulatory regions associated with gene transcription at an unprecedented level of refinement. By coupling transcription factor binding site (TFBS) enrichment analysis with CAGE-derived genomic regions, CAGEd-oPOSSUM can identify TFs that act as key regulators of genes involved in specific mammalian cell and tissue types. The webtool allows for the analysis of CAGE-derived transcription start sites (TSSs) either provided by the user or selected from ∼1300 mammalian samples from the FANTOM5 project with pre-computed TFBS predicted with JASPAR TF binding profiles. The tool helps power insights into the regulation of genes through the study of the specific usage of TSSs within specific cell types and/or under specific conditions. Availability and Implementation: The CAGEd-oPOSUM web tool is implemented in Perl, MySQL and Apache and is available at http://cagedop.cmmt.ubc.ca/CAGEd_oPOSSUM. Contacts: anthony.mathelier@ncmm.uio.no or wyeth@cmmt.ubc.ca Supplementary information: Supplementary data are available at Bioinformatics online. PMID:27334471

  16. Comparative Analysis of Interbody Cages Versus Tricortical Graft with Anterior Plate Fixation for Anterior Cervical Discectomy and Fusion in Degenerative Cervical Disc Disease

    PubMed Central

    Singh, Pritish; Shekhawat, Vishal

    2016-01-01

    Introduction Multiple techniques and modalities of fixation are used in Anterior Cervical Discectomy and interbody Fusion (ACDF), each with some merit and demerit against others. Such pool of techniques reflects lack of a consensus method conducive to uniformly good results. Aim A prospective study was done to analyse safety and efficacy of tricortical autograft and anterior cervical plate (Group A) with cylindrical titanium cage filled with cancellous bone (Group B) in procedure of ACDF for single level degenerative cervical disc disease. Materials and Methods Twenty patients with degenerative cervical disc disease were included in study for ACDF. After a computer generated randomisation, ten patients (10 segments) were operated with anterior locking plating and tricortical iliac crest graft (Group A, Tricortical graft group), while ten patients(10 segments) were operated with standalone cylindrical titanium cages filled with cancellous bone harvested using minimally invasive methods (Group B, Cage group) from April 2012 to May 2015. Odoms’s criteria, visual pain analogue score and sequential plain radiographs were obtained to assess for clinic-radiological outcome. Results According to Odom’s system of functional assessment, 9 patients from each group (90%) experienced good to excellent functional recovery and 9 of 10 (90%) patients of each groups were satisfied with outcome. In both groups, relief in neck pain or arm pain was similar without any statistical difference as assessed by visual analogue score. Fusion was present in 10 of 10 (100%) patients in tricortical graft group and 10 of 10 (100%) in cage group at the end of 6 months. There was no implant related complications in cage group. Transient postoperative dysphagia was recorded in 3 patients (2 in Group A and 1 in group B), which resolved within 3 days. In tricortical graft group, graft collapse and partial extrusion was detected in one patient, which did not correspond with good results obtained

  17. Adherence of sputtered titanium carbides

    NASA Technical Reports Server (NTRS)

    Brainard, W. A.; Wheeler, D. R.

    1979-01-01

    Sputtered coatings of the refractory metal carbides are of great interest for applications where hard wear-resistant materials are desired. The usefulness of sputtered refractory carbides is often limited, in practice, by spalling or interfacial separation. In this work improvements in the adherence of refractory carbides on iron, nickel and titanium based alloys were obtained by using oxidation, reactive sputtering or sputtered interlayers to alter the coating-substrate interfacial region. X-ray photoelectron spectroscopy and argon ion etching were used to characterize the interfacial regions, and an attempt was made to correlate adherence as measured in wear tests with the chemical nature of the interface.

  18. [The posterior lumbar interbody fusion with cages (PLIF) and transpedicular stabilization].

    PubMed

    Diedrich, O; Kraft, C N; Perlick, L; Schmitt, O

    2001-01-01

    The development of intervertebral cages has significantly innovated the original technique of posterior lumbar interbody fusion (PLIF). In this study we present the results of patients treated for degenerative or postoperative segmental spinal instabilities by PLIF with cages and pedicular stabilisation (360 degrees-instrumentation). Between 1992 and 1999 we implanted either CFRP-, PEEK- or Titanium-cages in 86 patients. 78 patients were adequately followed up over a period of at least 12 months (average 2,6 years). 5 patients were stabilised over 2 segments, so that ultimately 83 fused segments were evaluated.15% of all patients had an excellent, 51% a good, 28% a moderate and 5% an insufficient clinical result. Degenerative instabilities had a better outcome with 73% good or excellent clinical results, compared to postoperative instabilities (56%). Based on stringent radiographic fusion criteria we found true bony fusion in 52% of all segments after 12 months, 63% after 24 months, 72% after 36 months, and 78% after 48 months. In 21 segments cage packing was performed with autologous spongiosa, while in 62 segments a combination of cortical bone and spongiosa obtained from osseous structures at the operation-site were used as packing material. At the 24 month radiographic control we found a slightly higher fusion rate for those segments treated with autologous spongiosa obtained from the iliac crest. Neither for cages nor for pedicular screws was implant failure or material fatigue found. Serious entero-, pulmo-, cardio- or urological complications were not observed. Nonetheless the necessity for operative revision was 9%. A postoperative semiquantitative evaluation of segments neighbouring the fused vertebra revealed in 28% an increase in degenerative changes. Particularly after 360 degrees-instrumentation, interpretation of the fusion-status should be based on structural and not on functional criteria. The modification of PLIF with cages compared to the use of

  19. Osteogenic activity and antibacterial effect of zinc ion implanted titanium.

    PubMed

    Jin, Guodong; Cao, Huiliang; Qiao, Yuqin; Meng, Fanhao; Zhu, Hongqin; Liu, Xuanyong

    2014-05-01

    Titanium (Ti) and its alloys are widely used as orthopedic and dental implants. In this work, zinc (Zn) was implanted into oxalic acid etched titanium using plasma immersion ion implantation technology. Scanning electron microscopy and X-ray photoelectron spectroscopy were used to investigate the surface morphology and composition of Zn-implanted titanium. The results indicate that the depth profile of zinc in Zn-implanted titanium resembles a Gaussian distribution, and zinc exists in the form of ZnO at the surface whereas in the form of metallic Zn in the interior. The Zn-implanted titanium can significantly stimulate proliferation of osteoblastic MC3T3-E1 cells as well as initial adhesion, spreading activity, ALP activity, collagen secretion and extracellular matrix mineralization of the rat mesenchymal stem cells. The Zn-implanted titanium presents partly antibacterial effect on both Escherichia coli and Staphylococcus aureus. The ability of the Zn-implanted titanium to stimulate cell adhesion, proliferation and differentiation as well as the antibacterial effect on E. coli can be improved by increasing implantation time even to 2 h in this work, indicating that the content of zinc implanted in titanium can easily be controlled within the safe concentration using plasma immersion ion implantation technology. The Zn-implanted titanium with excellent osteogenic activity and partly antibacterial effect can serve as useful candidates for orthopedic and dental implants. PMID:24632388

  20. Repassivation of titanium and surface oxide film regenerated in simulated bioliquid.

    PubMed

    Hanawa, T; Asami, K; Asaoka, K

    1998-06-15

    The change in potential during repassivation of titanium in artificial bioliquids was examined, and the regenerated surface oxide film on titanium was characterized using X-ray photoelectron spectroscopy and Auger electron spectroscopy to elucidate the repassivation reaction of titanium in a biological system. The repassivation rate in Hanks' solution was slower than that in saline and was not influenced by the pH of the solution. This indicates that more titanium ions dissolve in a biological system than hitherto was predicted when the surface film is destroyed. Phosphate ions are taken up preferentially in the surface film during regeneration, and the film consists of titanium oxide and titanium oxyhydroxide containing titanium phosphate. Calcium ions and phosphate ions are adsorbed by the film after regeneration, and calcium phosphate or calcium titanium phosphate is formed at the outermost surface. Ions constituting Hanks' solution other than calcium and phosphate were absent from the surface oxide. PMID:9599028

  1. Sm@C2v(19138)-C76: A Non-IPR Cage Stabilized by a Divalent Metal Ion.

    PubMed

    Hao, Yajuan; Feng, Lai; Xu, Wei; Gu, Zhenggen; Hu, Ziqi; Shi, Zujin; Slanina, Zdeněk; Uhlík, Filip

    2015-05-01

    Although a non-IPR fullerene cage is common for endohedral cluster fullerenes, it is very rare for conventional endofullerenes M@C2n, probably because of the minimum geometry fit effect of the endohedral single metal ion. In this work, we report on a new non-IPR endofullerene Sm@C2v(19138)-C76, including its structural and electrochemical features. A combined study of single-crystal X-ray diffraction and DFT calculations not only elucidates the non-IPR cage structure of C2v(19138)-C76 but also suggests that the endohedral Sm(2+) ion prefers to reside along the C2 cage axis and close to the fused pentagon unit in the cage framework, indicative of a significant metal-cage interaction, which alone can stabilize the non-IPR cage. Furthermore, electrochemical studies reveal the fully reversible redox behaviors and small electrochemical gap of Sm@C2v(19138)-C76, which are comparable to those of IPR species Sm@D3h-C74. PMID:25782103

  2. Spatially resolved X-ray diffraction phase mapping and {alpha} {r_arrow} {beta} {r_arrow} {alpha} transformation kinetics in the heat-affected zone of commercially pure titanium arc welds

    SciTech Connect

    Elmer, J.W.; Wong, J.; Ressler, T.

    1998-11-01

    Spatially resolved X-ray diffraction (SRXRD) is used to map the {alpha} {r_arrow} {beta} {r_arrow} {alpha} phase transformation in the heat-affected zone (HAZ) of commercially pure titanium gas tungsten arc welds. In situ SRXRD experiments were conducted using a 180-{micro}m-diameter X-ray beam at the Stanford Synchrotron Radiation Laboratory (SSRL) (Stanford, CA) to probe the phases present in the HAZ of a 1.9 kW weld moving at 1.1 mm/s. Results of sequential linear X-ray diffraction scans made perpendicular to the weld direction were combined to construct a phase transformation map around the liquid weld pool. This map identifies six HAZ microstructural regions between the liquid weld pool and the base metal: (1) {alpha}-Ti that is undergoing annealing and recrystallization; (2) completely recrystallized {alpha}-Ti; (3) partially transformed {alpha}-Ti, where {alpha}-Ti and {beta}-Ti coexist; (4) single-phase {beta}-Ti; (5) back-transformed {alpha}Ti; and (6) recrystallized {alpha}-Ti plus back-transformed {alpha}-Ti. Although the microstructure consisted predominantly of {alpha}-Ti, both prior to and after the weld, the crystallographically textured starting material was altered during welding to produce different {alpha}-Ti textures within the resulting HAZ. Based on the travel speed of the weld, the {alpha} {r_arrow} {beta} transformation was measured to take 1.83 seconds during heat, while the {beta} {r_arrow} {alpha} transformation was measured to take 0.91 seconds during cooling. The {alpha} {r_arrow} {beta} transformation was characterized to be dominated by long-range diffusion growth on the leading (heating) side of the weld, while the {beta} {r_arrow} {alpha} transformation was characterized to be predominantly massive on the trailing (cooling) side of the weld, with a massive growth rate on the order of 100 {micro}m/s.

  3. Sealing glasses for titanium and titanium alloys

    DOEpatents

    Brow, R.K.; McCollister, H.L.; Phifer, C.C.; Day, D.E.

    1997-07-15

    Barium lanthanoborate sealing-glass compositions are provided comprising various combinations (in terms of mole-%) of boron oxide (B{sub 2}O{sub 3}), barium oxide (BaO), lanthanum oxide (La{sub 2}O{sub 3}), and at least one other oxide selected from the group consisting of aluminum oxide (Al{sub 2}O{sub 3}), calcium oxide (CaO), lithium oxide (Li{sub 2}O), sodium oxide (Na{sub 2}O), silicon dioxide (SiO{sub 2}), or titanium dioxide (TiO{sub 2}). These sealing-glass compositions are useful for forming hermetic glass-to-metal seals with titanium and titanium alloys having an improved aqueous durability and favorable sealing characteristics. Examples of the sealing-glass compositions are provided having coefficients of thermal expansion about that of titanium or titanium alloys, and with sealing temperatures less than about 900 C, and generally about 700--800 C. The barium lanthanoborate sealing-glass compositions are useful for components and devices requiring prolonged exposure to moisture or water, and for implanted biomedical devices (e.g. batteries, pacemakers, defibrillators, pumps). 1 fig.

  4. Sealing glasses for titanium and titanium alloys

    DOEpatents

    Brow, Richard K.; McCollister, Howard L.; Phifer, Carol C.; Day, Delbert E.

    1997-01-01

    Barium lanthanoborate sealing-glass compositions are provided comprising various combinations (in terms of mole-%) of boron oxide (B.sub.2 O.sub.3), barium oxide (BaO), lanthanum oxide (La.sub.2 O.sub.3), and at least one other oxide selected from the group consisting of aluminum oxide (Al.sub.2 O.sub.3), calcium oxide (CaO), lithium oxide (Li.sub.2 O), sodium oxide (Na.sub.2 O), silicon dioxide (SiO.sub.2), or titanium dioxide (TiO.sub.2). These sealing-glass compositions are useful for forming hermetic glass-to-metal seals with titanium and titanium alloys having an improved aqueous durability and favorable sealing characteristics. Examples of the sealing-glass compositions are provided having coefficients of thermal expansion about that of titanium or titanium alloys, and with sealing temperatures less than about 900.degree. C., and generally about 700.degree.-800.degree. C. The barium lanthanoborate sealing-glass compositions are useful for components and devices requiring prolonged exposure to moisture or water, and for implanted biomedical devices (e.g. batteries, pacemakers, defibrillators, pumps).

  5. Biomechanical study of a hat type cervical intervertebral fusion cage

    PubMed Central

    Jia, Lian-Shun; Chen, Tong-Yi

    2006-01-01

    The purpose of this study was to evaluate the biomechanical effect of a hat type cervical intervertebral fusion cage (HCIFC). In this in vitro biomechanical study, 48 goat cervical spines (C2-5) were tested in flexion, extension, axial rotation, and lateral bending with a nondestructive stiffness method using a nonconstrained testing apparatus, and three-dimensional displacement was measured. Autologous iliac bone and cervical spine intervertebral fusion cage were implanted according to manufacturers’ information after complete discectomy (C3-4). Eight spines in each of the following groups were tested: intact, autologous iliac bone graft, Harms cage, SynCage C, carbon cage, and HCIFC. The mean apparent stiffness values were calculated from the corresponding load-displacement curves. Additionally, cage volume and volume-related stiffness were determined. The stiffness of the SynCage C was statistically greatest in all directions. After implantation of the HCIFC, flexion stiffness increased compared with that of the intact motion segment. There was no significant difference in stiffness between the HCIFC and carbon cage. The stiffness of the HCIFC was statistically higher than that of the Harms cage in axial rotation and significantly lower in flexion, extension, and lateral bending. Volume-related stiffness of all cages was higher than that of iliac bone graft. The Harms cage was highest in volume-related stiffness in all directions. The HCIFC can provide enough primary stability for cervical intervertebral fusion. PMID:16763843

  6. X-ray crystallographic characterization of new soluble endohedral fullerenes utilizing the popular C82 bucky cage. Isolation and structural characterization of Sm@C3v(7)-C82, Sm@C(s)(6)-C82, and Sm@C2(5)-C82.

    PubMed

    Yang, Hua; Jin, Hongxiao; Wang, Xinqing; Liu, Ziyang; Yu, Meilan; Zhao, Fukun; Mercado, Brandon Q; Olmstead, Marilyn M; Balch, Alan L

    2012-08-29

    Three isomers of Sm@C(82) that are soluble in organic solvents were obtained from the carbon soot produced by vaporization of hollow carbon rods doped with Sm(2)O(3)/graphite powder in an electric arc. These isomers were numbered as Sm@C(82)(I), Sm@C(82)(II), and Sm@C(82)(III) in order of their elution times from HPLC chromatography on a Buckyprep column with toluene as the eluent. The identities of isomers, Sm@C(82)(I) as Sm@C(s)(6)-C(82), Sm@C(82)(II) as Sm@C(3v)(7)-C(82), and Sm@C(82)(III) as Sm@C(2)(5)-C(82), were determined by single-crystal X-ray diffraction on cocrystals formed with Ni(octaethylporphyrin). For endohedral fullerenes like La@C(82), which have three electrons transferred to the cage to produce the M(3+)@(C(82))(3-) electronic distribution, generally only two soluble isomers (e.g., La@C(2v)(9)-C(82) (major) and La@C(s)(6)-C(82) (minor)) are observed. In contrast, with samarium, which generates the M(2+)@(C(82))(2-) electronic distribution, five soluble isomers of Sm@C(82) have been detected, three in this study, the other two in two related prior studies. The structures of the four Sm@C(82) isomers that are currently established are Sm@C(2)(5)-C(82), Sm@C(s)(6)-C(82), Sm@C(3v)(7)-C(82), and Sm@C(2v)(9)-C(82). All of these isomers obey the isolated pentagon rule (IPR) and are sequentially interconvertable through Stone-Wales transformations. PMID:22860880

  7. Sprayable titanium composition

    DOEpatents

    Tracy, Chester E.; Kern, Werner; Vibronek, Robert D.

    1980-01-01

    The addition of 2-ethyl-1-hexanol to an organometallic titanium compound dissolved in a diluent and optionally containing a lower aliphatic alcohol spreading modifier, produces a solution that can be sprayed onto a substrate and cured to form an antireflection titanium oxide coating having a refractive index of from about 2.0 to 2.2.

  8. Comparison between Two Different Cervical Interbody Fusion Cages in One Level Stand-alone ACDF: Carbon Fiber Composite Frame Cage Versus Polyetheretherketone Cage

    PubMed Central

    Yoo, Minwook; Kim, Wook-Ha; Hyun, Seung-Jae; Jahng, Tae-Ahn; Kim, Hyun-Jib

    2014-01-01

    Objective The authors conducted a retrospective study to compare the implantation of carbon fiber composite frame cages (CFCFCs) to the implantation of polyetheretherketone (PEEK) cages after anterior cervical discectomy for cervical degenerative disc disease. In addition, the predictive factors that influenced fusion or subsidence were investigated. Methods A total of 58 patients with single-level degenerative disc disease were treated with anterior cervical discectomy and implantation of stand-alone cages; CFCFCs were used in 35 patients, and PEEK cages were used in 23 patients. Preoperative and postoperative radiological and clinical assessments were performed. Results During the mean follow-up period of 41 months, fusion occurred in 43 patients (74.1%), and subsidence developed in 18 patients (31.0%). Pain decreased in all patients, and the patients' satisfaction rate was 75.9%. Neither fusion nor subsidence was related to the clinical outcome. There were no significant differences in the clinical and radiological outcomes between the CFCFC and the PEEK cage groups. Smoking history (p=0.023) was significantly associated with pseudarthrosis, and cage height (≥7mm) (p=0.037) were significantly associated with subsidence. Conclusion The clinical and radiological results were similar between the CFCFC and the PEEK cage groups. Fusion or subsidence did not affect the clinical outcomes. Smoking history and cage height (≥7mm) were predictive factors for pseudarthrosis or subsidence in anterior cervical discectomy and fusion with stand-alone cages. PMID:25346758

  9. Stainless Steel to Titanium Bimetallic Transitions

    SciTech Connect

    Kaluzny, J. A.; Grimm, C.; Passarelli, D.

    2015-01-01

    In order to use stainless steel piping in an LCLS-II (Linac Coherent Light Source Upgrade) cryomodule, stainless steel to titanium bimetallic transitions are needed to connect the stainless steel piping to the titanium cavity helium vessel. Explosion bonded stainless steel to titanium transition pieces and bimetallic transition material samples have been tested. A sample transition tube was subjected to tests and x-ray examinations between tests. Samples of the bonded joint material were impact and tensile tested at room temperature as well as liquid helium temperature. The joint has been used successfully in horizontal tests of LCLS-II cavity helium vessels and is planned to be used in LCLS-II cryomodules. Results of material sample and transition tube tests will be presented.

  10. Stainless steel to titanium bimetallic transitions

    NASA Astrophysics Data System (ADS)

    Kaluzny, J. A.; Grimm, C.; Passarelli, D.

    2015-12-01

    In order to use stainless steel piping in an LCLS-II (Linac Coherent Light Source Upgrade) cryomodule, stainless steel to titanium bimetallic transitions are needed to connect the stainless steel piping to the titanium cavity helium vessel. Explosion bonded stainless steel to titanium transition pieces and bimetallic transition material samples have been tested. A sample transition tube was subjected to tests and x-ray examinations between tests. Samples of the bonded joint material were impact and tensile tested at room temperature as well as liquid helium temperature. The joint has been used successfully in horizontal tests of LCLS-II cavity helium vessels and is planned to be used in LCLS-II cryomodules. Results of material sample and transition tube tests will be presented. Operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the United States Department of Energy.

  11. Biology's built-in Faraday cages

    NASA Astrophysics Data System (ADS)

    Klee, Maurice M.

    2014-05-01

    Biological fluids are water-based, ionic conductors. As such, they have both high relative dielectric constants and substantial conductivities, meaning they are lossy dielectrics. These fluids contain charged molecules (free charges), whose movements play roles in essentially all cellular processes from metabolism to communication with other cells. Using the problem of a point source in air above a biological fluid of semi-infinite extent, the bound charges in the fluid are shown to perform the function of a fast-acting Faraday cage, which protects the interior of the fluid from external electric fields. Free charges replace bound charges in accordance with the fluid's relaxation time, thereby providing a smooth transition between the initial protection provided by the bound charges and the steady state protection provided by the free charges. The electric fields within the biological fluid are thus small for all times just as they would be inside a classical Faraday cage.

  12. Screening Surface Contamination with BetaCage

    SciTech Connect

    Schnee, R. W.; Grant, D. R.; Poinar, K.; Ahmed, Z.; Golwala, S. R.

    2007-03-28

    Existing screening facilities are insufficiently sensitive to meet the needs of rare-event experiments for low-energy electron emitters and alpha-decaying isotopes. To provide such screening, the BetaCage will be a low-background, atmospheric-pressure neon drift chamber with unprecedented sensitivity to emitters of low-energy electrons and alpha particles. Minimization of the detector mass and use of radiopure materials reduce background events. The chamber design accepts nearly all alphas and low-energy electrons from the sample surface while allowing excellent rejection of residual backgrounds. A non-radiopure prototype is under construction to test the design. The BetaCage will provide new infrastructure for rare-event science as well as for a wider community that uses radioactive screening for areas including archaeology, biology, climatology, environmental science, geology, planetary science, and integrated-circuit quality control.

  13. Rotational and constitutional dynamics of caged supramolecules

    PubMed Central

    Kühne, Dirk; Klappenberger, Florian; Krenner, Wolfgang; Klyatskaya, Svetlana; Ruben, Mario; Barth, Johannes V.

    2010-01-01

    The confinement of molecular species in nanoscale environments leads to intriguing dynamic phenomena. Notably, the organization and rotational motions of individual molecules were controlled by carefully designed, fully supramolecular host architectures. Here we use an open 2D coordination network on a smooth metal surface to steer the self-assembly of discrete trimeric guest units, identified as noncovalently bound dynamers. Each caged chiral supramolecule performs concerted, chirality-preserving rotary motions within the template honeycomb pore, which are visualized and quantitatively analyzed using temperature-controlled scanning tunneling microscopy. Furthermore, with higher thermal energies, a constitutional system dynamics appears, which is revealed by monitoring repetitive switching events of the confined supramolecules’ chirality signature, reflecting decay and reassembly of the caged units. PMID:21098303

  14. The biomimetic apatite-cefalotin coatings on modified titanium.

    PubMed

    Kang, Min-Kyung; Lee, Sang-Bae; Moon, Seung-Kyun; Kim, Kwang-Mahn; Kim, Kyoung-Nam

    2012-02-01

    Dental implant failure often occurs due to oral bacterial infection. The aim of this study was to demonstrate that antibiotic efficacy could be enhanced with modified titanium. First, the titanium was modified by anodization and heat-treatment. Then, a biomimetic coating process was completed in two steps. Surface characterization was performed with scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. Release of antibiotic was evaluated by UV/VIS spectrometry, and the antibacterial effect was evaluated on Streptococcus mutans. After the second coating step, we observed a thick homogeneous apatite layer that contained the antibiotic, cefalotin. The titanium formed a rutile phase after the heat treatment, and a carbonated apatite phase appeared after biomimetic coating. We found that the modified titanium increased the loading of cefalotin onto the hydroxyapatite coated surface. The results suggested that modified titanium coated with a cefalotin using biomimetic coating method might be useful for preventing local post-surgical implant infections. PMID:22277612

  15. Synthesis and Structural Characterization of a Cyclen-Derived Molecular Cage.

    PubMed

    Ganss, Alexander; Belda, Raquel; Pitarch, Javier; Goddard, Richard; García-España, Enrique; Kubik, Stefan

    2015-12-01

    Reaction of a tetrafunctionalized cyclen derivative containing four aldehyde groups with an appropriate diamine followed by reduction and demetalation highly efficiently affords a bis(cyclen)-derived molecular cage. Potentiometric investigations show that this compound forms dimetallic complexes with copper(II), with the two metal ions selectively coordinated to the cyclen units. X-ray crystallography indicates that these complexes could give rise to new cascade complexes after incorporation of anions between the metal centers. PMID:26575498

  16. Capturing the antiaromatic (#6094) C68 carbon cage in the radio-frequency furnace.

    PubMed

    Amsharov, Konstantin Yu; Ziegler, Karolin; Mueller, Andreas; Jansen, Martin

    2012-07-23

    Although all fullerenes do not satisfy the classical aromaticity condition, as a result of their nonplanar nature, they experience effective stabilization due to extensive cyclic π-electron delocalization and exhibit pronounced "spherical aromaticity". This feature has raised the question of the opposite phenomenon, that is, the existence of antiaromatic carbon cages. Here the first experimental evidence of the existence of antiaromatic fullerenes is reported. The elusive (#6094)C(68) was effectively captured as C(68)Cl(8) by in situ chlorination in the gas phase during radio-frequency synthesis. The chlorinated cage was separated by means of multistage HPLC, and its connectivity unambiguously determined by single-crystal X-ray analysis. Halogen-stripped pristine (#6094)C(68) was monitored by mass spectrometry of the chlorinated C(68)Cl(8) cage. Quantum chemical calculations reveal the highly antiaromatic character of (#6094)C(68), in accordance with all geometric, energetic, and magnetic criteria of aromaticity. Chlorine addition leads to substantial stabilization of the cage owing to aromatization in the resulting C(68)Cl(8), which explains its high abundance in the primary fullerene soot. This work provides new insights into the process of fullerene formation and better understanding of aromaticity phenomena in general. PMID:22736420

  17. Molecular structures of two tetrodotoxin analogs containing a monooxa-hydrocarbon cage: A computational study

    NASA Astrophysics Data System (ADS)

    Pichierri, Fabio

    2016-02-01

    Using quantum chemical calculations we investigate the molecular structures of two tetrodotoxin (TTX) analogs recently isolated from the Japanese toxic newt Cynops ensicauda popei. These novel analogs are characterized by a monooxa-hydrocarbon cage with a direct C5-C10 bond that replaces one of the ether bridges in the canonical dioxa-adamantane cage of TTX. The computed change in the 13C NMR chemical shifts is in good agreement with the change in the corresponding experimental values that results from the above chemical modification. This confirms the chemical structure assigned to the TTX analogs. A topological analysis of the theoretical electronic charge density indicates that the removal of the oxygen bridge in TTX increases the magnitude of the charge density at the cage critical point. A database search indicates that the monooxa-hydrocarbon cage is also present in other natural products such as cinnzeylanine and platensimycin whose molecular structures have been characterized by single-crystal X-ray diffraction analyses.

  18. Luminescent Cages: Pendant Emissive Units on [Pd2L4](4+) "Click" Cages.

    PubMed

    Elliott, Anastasia B S; Lewis, James E M; van der Salm, Holly; McAdam, C John; Crowley, James D; Gordon, Keith C

    2016-04-01

    The photophysics of a family of exo-functionalized [Pd2L4](4+) metallo-supramolecular cage architectures constructed from a tripyridyl 1,2,3-triazole backbone are reported. Several spectroscopic techniques are employed including both electronic (steady-state and transient absorption and emission) and vibrational (resonant and nonresonant Raman) methods. These experimental results are interpreted alongside simulated results from density functional theory calculations of the system's vibrational and electronic properties. The ligands and cages are shown to be essentially insulated from the exo-functionalization. They exhibit electronic transitions in the UV region and excited-state properties that are little affected by formation of the cage. Upon functionalization, characteristic Raman bands, electronic transitions, and emission bands associated with, and confined to, the substituent are observed. PMID:26991000

  19. Thermo-Electromotive Force and Electrical Resistivity of Hydrogenated VT1-0 Titanium Alloy

    NASA Astrophysics Data System (ADS)

    Lider, A.; Larionov, V.; Kroening, M.; Kudiiarov, V.

    2016-06-01

    The method for measuring the structure transition of hydrogenated titanium from one state to another is suggested. The method is based on the comparison of thermo-electromotive force (thermo-emf), DC electrical resistance and the results of X-ray diffraction analysis. X-ray diffraction analysis is applied for identifying the quantity of defects in titanium structure. The authors have also identified the identical dependence of thermo-electromotive force and electrical resistivity on hydrogen concentration in titanium. The effect can be used for hydrogenated titanium structure control.

  20. Non-Gaussian nature of glassy dynamics by cage to cage motion

    SciTech Connect

    Vorselaars, Bart; Lyulin, Alexey V.; Michels, M. A. J.; Karatasos, K.

    2007-01-15

    A model based on a single Brownian particle moving in a periodic effective field is used to understand the non-Gaussian dynamics in glassy systems of cage escape and subsequent recaging, often thought to be caused by a heterogeneous glass structure. The results are compared to molecular-dynamics simulations of systems with varying complexity: quasi-two-dimensional colloidlike particles, atactic polystyrene, and a dendritic glass. The model nicely describes generic features of all three topologically different systems, in particular around the maximum of the non-Gaussian parameter. This maximum is a measure for the average distance between cages.

  1. The impact of reduced frequency of cage changes on the health of mice housed in ventilated cages.

    PubMed

    Reeb-Whitaker, C K; Paigen, B; Beamer, W G; Bronson, R T; Churchill, G A; Schweitzer, I B; Myers, D D

    2001-01-01

    Our purpose in this investigation was to determine if we could reduce cage changing frequency without adversely affecting the health of mice. We housed mice at three different cage changing frequencies: 7, 14, and 21 days, each at three different cage ventilation rates: 30, 60 and 100 air changes per hour (ACH), for a total of nine experimental conditions. For each condition, we evaluated the health of 12 breeding pairs and 12 breeding trios of C57BL/6J mice for 7 months. Health was assessed by breeding performance, weanling weight and growth, plasma corticosterone levels, immune function, and histological examination of selected organs. Over a period of 4 months, we monitored the cage microenvironment for ammonia and carbon dioxide concentrations, relative humidity, and temperature one day prior to changing the cage. The relative humidity, carbon dioxide concentrations, and temperature of the cages at all conditions were within acceptable levels. Ammonia concentrations remained below 25 ppm (parts per million) in most cages, but, even at higher concentrations, did not adversely affect the health of mice. Frequency of cage changing had only one significant effect; pup mortality with pair matings was greater at the cage changing frequency of 7 days compared with 14 or 21 days. In addition, pup mortality with pair matings was higher at 30 ACH compared with other ventilation rates. In conclusion, under the conditions of this study, cage changes once every 14 days and ventilation rates of 60 ACH provide optimum conditions for animal health and practical husbandry. PMID:11201289

  2. Influence of 5 Different Caging Types and the Use of Cage-Changing Stations on Mouse Allergen Exposure

    PubMed Central

    Feistenauer, Susan; Sander, Ingrid; Schmidt, Jörg; Zahradnik, Eva; Raulf, Monika; Brielmeier, Markus

    2014-01-01

    Animal allergens constitute a serious health risk in laboratory animal facilities. To assess possibilities for allergen reduction by technical and organizational measures, we studied personnel exposure to mouse urinary aeroallergens in an animal facility with a holding capacity of 30,000 cages. Short-term (2 h) and intermediate-term (12 h) stationary samples (n = 107) and short-term (2 h) personnel samples (n = 119) were collected on polytetrafluorethylene filters by using air pumps. Long-term (14 d) stationary dust samples containing airborne allergens (n = 165) were collected with electrostatic dust fall collectors (EDC). Mouse allergens were quantified by ELISA. Personnel samples were collected during bedding disposal and refilling of clean cages as well as during cage changing with and without use of cage-changing station. Animal rooms were equipped with either open cages, cages with a soft filter top, cages with a rigid filter top (static microisolation caging), or with individually ventilated cages (IVC) with either a sealed or nonsealed lid, each in positive- or negative-pressure mode. Highest personnel allergen exposure was detected during cage change and emptying of soiled cages. Allergen concentrations were lowest in rooms with sealed IVC under positive or negative pressure, with unsealed IVC under negative pressure, and with static microisolation caging. The use of cage-changing stations and a vacuum bedding-disposal system reduced median personnel exposures 14- to 25-fold, respectively. Using sealed IVC and changing stations minimized allergen exposure, indicating that state-of-the-art equipment reduces exposure to mouse allergens and decreases health risks among animal facility personnel. PMID:25199090

  3. Mitochondria mediate septin cage assembly to promote autophagy of Shigella.

    PubMed

    Sirianni, Andrea; Krokowski, Sina; Lobato-Márquez, Damián; Buranyi, Stephen; Pfanzelter, Julia; Galea, Dieter; Willis, Alexandra; Culley, Siân; Henriques, Ricardo; Larrouy-Maumus, Gerald; Hollinshead, Michael; Sancho-Shimizu, Vanessa; Way, Michael; Mostowy, Serge

    2016-07-01

    Septins, cytoskeletal proteins with well-characterised roles in cytokinesis, form cage-like structures around cytosolic Shigella flexneri and promote their targeting to autophagosomes. However, the processes underlying septin cage assembly, and whether they influence S. flexneri proliferation, remain to be established. Using single-cell analysis, we show that the septin cages inhibit S. flexneri proliferation. To study mechanisms of septin cage assembly, we used proteomics and found mitochondrial proteins associate with septins in S. flexneri-infected cells. Strikingly, mitochondria associated with S. flexneri promote septin assembly into cages that entrap bacteria for autophagy. We demonstrate that the cytosolic GTPase dynamin-related protein 1 (Drp1) interacts with septins to enhance mitochondrial fission. To avoid autophagy, actin-polymerising Shigella fragment mitochondria to escape from septin caging. Our results demonstrate a role for mitochondria in anti-Shigella autophagy and uncover a fundamental link between septin assembly and mitochondria. PMID:27259462

  4. The effect of pesticide residue on caged mosquito bioassays.

    PubMed

    Barber, J A S; Greer, Mike; Coughlin, Jamie

    2006-09-01

    Wind tunnel experiments showed that secondary pickup of insecticide residue by mosquitoes in cage bioassays had a significant effect on mortality. Cage bioassays using adult Ochlerotatus taeniorhynchus (Wiedemann) investigated the effect of exposure time to a contaminated surface. Cages were dosed in a wind tunnel using the LC50 for naled (0.124 mg a.i./ml) and an LC25 (0.0772 mg a.i./ml) for naled. Half of the bioassay mosquitoes were moved directly into clean cages with the other half remaining in the sprayed, hence contaminated, cage. Treatment mortality was assessed at 8, 15, 30, 60, 120, 240, and 1,440 min postapplication. Cage contamination had a significant effect on mosquito mortality for both the LC25 and LC50 between 15 and 30 min postapplication. PMID:17067048

  5. Dissolution of surface oxide layers on titanium and titanium subhydride between 25/sup 0/ and 700/sup 0/C

    SciTech Connect

    Wittberg, T.N.; Wang, P.S.

    1981-01-01

    The surface-sensitive, spectroscopic techniques of Auger electron spectroscopy (AES) and x-ray photoelectron spectroscopy (XPS) have been applied to the study of oxide dissolution on titanium and titanium subhydride. In an earlier study it was shown, using AES, that the rate of oxygen dissolution into titanium increased sharply at about 350/sup 0/C. These data correlated well with physical property measurements that indicated that at these temperatures an exothermic reaction, corresponding to the reaction of free titanium with atmospheric oxygen, was occurring. In the present study the work has been expanded to include studies of TiH/sub x/ (x = 1.15, 1.62). It has been found that dissolution of the native oxide on titanium subhydride occurs at a substantially higher temperature (about 500/sup 0/C) than for titanium. It appears that the outward diffusion of hydrogen is inhibiting the inward diffusion of oxygen on the subhydride samples at temperatures below 500/sup 0/C. Further studies of the dissolution of oxides on titanium at fixed temperatures in the range of 300 to 350/sup 0/C have shown that there is a semi-logarithmic relationship between the surface oxygen level and the time at temperature. This is in agreement with earlier gravimetric studies on titanium oxidation in this temperature range.

  6. Enhanced compatibility of chemically modified titanium surface with periodontal ligament cells

    NASA Astrophysics Data System (ADS)

    Kado, T.; Hidaka, T.; Aita, H.; Endo, K.; Furuichi, Y.

    2012-12-01

    A simple chemical modification method was developed to immobilize cell-adhesive molecules on a titanium surface to improve its compatibility with human periodontal ligament cells (HPDLCs).The polished titanium disk was immersed in 1% (v/v) p-vinylbenzoic acid solution for 2 h to introduce carboxyl groups onto the surface. After rinsing with distilled deionized water, the titanium disk was dipped into 1.47% 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide solution containing 0.1 mg/ml Gly-Arg-Gly-Asp-Ser (GRGDS), human plasma fibronectin (pFN), or type I collagen from calf skin (Col) to covalently immobilize the cell-adhesive molecules on the titanium surface via formation of peptide bonds. X-ray photoelectron spectroscopy analyses revealed that cell-adhesive molecules were successfully immobilized on the titanium surfaces. The Col-immobilized titanium surface revealed higher values regarding nano rough characteristics than the as-polished titanium surface under scanning probe microscopy. The number of HPDLCs attached to both the pFN- and Col-immobilized titanium surfaces was twice that attached to the as-polished titanium surfaces. The cells were larger with the cellular processes that stretched to a greater extent on the pFN- and Col-immobilized titanium surfaces than on the as-polished titanium surface (p < 0.05). HPDLCs on the Col-immobilized titanium surfaces showed more extensive expression of vinculin at the tips of cell projections and more contiguously along the cell outline than on the as-polished, GRGDS-immobilized and pFN-immobilized titanium surfaces. It was concluded that cell-adhesive molecules successfully immobilized on the titanium surface and improved the compatibility of the surface with HPDLCs. The Col-immobilized titanium surface could be used for forming ligament-like tissues around titanium dental implants.

  7. Molecular Cage Impregnated Palladium Nanoparticles: Efficient, Additive-Free Heterogeneous Catalysts for Cyanation of Aryl Halides.

    PubMed

    Mondal, Bijnaneswar; Acharyya, Koushik; Howlader, Prodip; Mukherjee, Partha Sarathi

    2016-02-10

    Two shape-persistent covalent cages (CC1(r) and CC2(r)) have been devised from triphenyl amine-based trialdehydes and cyclohexane diamine building blocks utilizing the dynamic imine chemistry followed by imine bond reduction. The cage compounds have been characterized by several spectroscopic techniques which suggest that CC1(r) and CC2(r) are [2+3] and [8+12] self-assembled architectures, respectively. These state-of-the-art molecules have a porous interior and stable aromatic backbone with multiple palladium binding sites to engineer the controlled synthesis and stabilization of ultrafine palladium nanoparticles (PdNPs). As-synthesized cage-embedded PdNPs have been characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and powder X-ray diffraction (PXRD). Inductively coupled plasma optical emission spectrometry reveals that Pd@CC1(r) and Pd@CC2(r) have 40 and 25 wt% palladium loading, respectively. On the basis of TEM analysis, it has been estimated that as small as ∼1.8 nm PdNPs could be stabilized inside the CC1(r), while larger CC2(r) could stabilize ∼3.7 nm NPs. In contrast, reduction of palladium salts in the absence of the cages form structure less agglomerates. The well-dispersed cage-embedded NPs exhibit efficient catalytic performance in the cyanation of aryl halides under heterogeneous, additive-free condition. Moreover, these materials have excellent stability and recyclability without any agglomeration of PdNPs after several cycles. PMID:26771385

  8. Gold Sulfide Nanoclusters: A Unique Core-in-cage Structure

    SciTech Connect

    Jiang, Deen; Walter, Michael; Dai, Sheng

    2010-01-01

    By using a DFT-based basin-hopping method, we found putative global minima for three gold sulfide nanoclusters, observed in mass spectrometry, that all show a symmetric core-in-cage structure: a metallic Au core inside a cage with S as vertices and Au at the edges. This core-in-cage structure is distinct from bulk gold sulfide. This work fills the knowledge gap regarding the structure of gold sulfide nanoclusters of {approx}1 nm.

  9. Extended cage adjustable speed electric motors and drive packages

    DOEpatents

    Hsu, John S.

    1999-01-01

    The rotor cage of a motor is extended, a second stator is coupled to this extended rotor cage, and the windings have the same number of poles. The motor torque and speed can be controlled by either injecting energy into or extracting energy out from the rotor cage. The motor produces less harmonics than existing doubly-fed motors. Consequently, a new type of low cost, high efficiency drive is produced.

  10. Extended cage adjustable speed electric motors and drive packages

    DOEpatents

    Hsu, J.S.

    1999-03-23

    The rotor cage of a motor is extended, a second stator is coupled to this extended rotor cage, and the windings have the same number of poles. The motor torque and speed can be controlled by either injecting energy into or extracting energy out from the rotor cage. The motor produces less harmonics than existing doubly-fed motors. Consequently, a new type of low cost, high efficiency drive is produced. 12 figs.

  11. Electroplating on titanium alloy

    NASA Technical Reports Server (NTRS)

    Lowery, J. R.

    1971-01-01

    Activation process forms adherent electrodeposits of copper, nickel, and chromium on titanium alloy. Good adhesion of electroplated deposits is obtained by using acetic-hydrofluoric acid anodic activation process.

  12. Effect of titanium dioxide nanoparticles on gamma-ray treatment of phenol in different matrices: implications in toxicity toward Daphnia magna.

    PubMed

    Kang, Sung-Wook; Shim, Seung-Bo; Yoo, Jisu; Jung, Jinho

    2012-10-01

    Gamma-ray treatment of phenol was studied in terms of both chemical degradation and toxicological change. About 90% of phenol (5.0 × 10(-4) M) in ultrapure water (UW) was eliminated by gamma-irradiation at a dose of 10 kGy, but acute toxicity was dramatically increased, particularly for dose of 1 kGy, due to the formation of more toxic by-products such as hydroquinone, benzoquinone, resorcinol and catechol. The addition of TiO(2) nanoparticles had little effect on the removal of phenol in UW, but substantially enhanced the mineralization of phenol compared with gamma-irradiation alone. Additionally, degradation of phenol by gamma-irradiation was inhibited in a wastewater effluent (WE) matrix, likely due to the presence of dissolved organic carbon (22.06 mg L(-1)). Furthermore, lower concentrations of toxic by-products were generated both in WE and in the presence of TiO(2) nanoparticles, resulting in reduction of toxicity increase by gamma-irradiation. Meanwhile, the toxicity of gamma-ray treated phenol in WE was well estimated with simple summation of individual toxicity of phenol and by-products (R (2) = 0.9678). PMID:22875283

  13. Urea-Functionalized M4L6 Cage Receptors: Self-Assembly, Dynamics, and Anion Recognition in Aqueous Solutions

    SciTech Connect

    Custelcean, Radu; Bonnesen, Peter V; Duncan, Nathan C; Van Berkel, Gary J; Hay, Benjamin

    2012-01-01

    We present an extensive study of a novel class of de novo designed tetrahedral M{sub 4}L{sub 6} (M = Ni, Zn) cage receptors, wherein internal decoration of the cage cavities with urea anion-binding groups, via functionalization of the organic components L, led to selective encapsulation of tetrahedral oxoanions EO{sub 4}{sup -} (E = S, Se, Cr, Mo, W, n = 2; E = P, n = 3) from aqueous solutions, based on shape, size, and charge recognition. External functionalization with tBu groups led to enhanced solubility of the cages in aqueous methanol solutions, thereby allowing for their thorough characterization by multinuclear ({sup 1}H, {sup 13}C, {sup 77}Se) and diffusion NMR spectroscopies. Additional experimental characterization by electrospray ionization mass spectrometry, UV-vis spectroscopy, and single-crystal X-ray diffraction, as well as theoretical calculations, led to a detailed understanding of the cage structures, self-assembly, and anion encapsulation. We found that the cage self-assembly is templated by EO{sub 4}{sup -} oxoanions (n {ge} 2), and upon removal of the templating anion the tetrahedral M{sub 4}L{sub 6} cages rearrange into different coordination assemblies. The exchange selectivity among EO{sub 4}{sup -} oxoanions has been investigated with {sup 77}Se NMR spectroscopy using {sup 77}SeO{sub 4}{sup 2-} as an anionic probe, which found the following selectivity trend: PO{sub 4}{sup 3-} CrO{sub 4}{sup 2-} > SO{sub 4}{sup 2-} > SeO{sub 4}{sup 2-} > MoO{sub 4}{sup 2-} > WO{sub 4}{sup 2-}. In addition to the complementarity and flexibility of the cage receptor, a combination of factors have been found to contribute to the observed anion selectivity, including the anions charge, size, hydration, basicity, and hydrogen-bond acceptor abilities.

  14. Application of bicyclic and cage compounds

    NASA Technical Reports Server (NTRS)

    Clark, R. D.; Archuleta, B. S.

    1976-01-01

    The results of a literature survey of the field of bicyclic and cage compounds were presented, with the objective of identifying those types of compounds with unusual physical and chemical stability, and determining what practical applications have been found for these compounds. Major applications have been as polymers, polymer additives, medicinals, and pesticides. Lesser applications have included fuels, fuel additives, lubricants, lubricant additives, and perfumes. Several areas where further work might be useful were also outlined; these are primarily in the areas of polymers, polymer additives, medicinals, and synthetic lubricants.

  15. Titanium Allergy: A Literature Review

    PubMed Central

    Goutam, Manish; Giriyapura, Chandu; Mishra, Sunil Kumar; Gupta, Siddharth

    2014-01-01

    Titanium has gained immense popularity and has successfully established itself as the material of choice for dental implants. In both medical and dental fields, titanium and its alloys have demonstrated success as biomedical devices. Owing to its high resistance to corrosion in a physiological environment and the excellent biocompatibility that gives it a passive, stable oxide film, titanium is considered the material of choice for intraosseous use. There are certain studies which show titanium as an allergen but the resources to diagnose titanium sensivity are very limited. Attention is needed towards the development of new and precise method for early diagnosis of titanium allergy and also to find out the alternative biomaterial which can be used in place of titanium. A review of available articles from the Medline and PubMed database was done to find literature available regarding titanium allergy, its diagnosis and new alternative material for titanium. PMID:25484409

  16. Titanium nanostructural surface processing for improved biocompatibility

    SciTech Connect

    Cheng, H.-C.; Lee, S.-Y.; Chen, C.-C.; Shyng, Y.-C.; Ou, K.-L.

    2006-10-23

    X-ray photoelectron spectroscopy, grazing incident x-ray diffraction, transmission electron microscopy, and scanning electron microscopy were conducted to evaluate the effect of titanium hydride on the formation of nanoporous TiO{sub 2} on Ti during anodization. Nano-titanium-hydride was formed cathodically before anodizing and served as a sacrificial nanoprecipitate during anodization. Surface oxidation occurred and a multinanoporous structure formed after cathodic pretreatments followed by anodization treatment. The sacrificial nanoprecipitate is directly dissolved and the Ti transformed to nanoporous TiO{sub 2} by anodization. The formation of sacrificial nanoprecipitates by cathodic pretreatment and of the multinanostructure by anodization is believed to improve biocompatibility, thereby promoting osseointegration.

  17. Horizontal transmission of Salmonella and Campylobacter among caged and cage-free laying hens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In each of five trials, laying hens (56-72 wk-of-age) were challenged orally, intracolonally, and intravaginally with Salmonella and Campylobacter. One wk post inoculation, challenged hens (n=3) were commingled with non-challenged hens (n=12) in conventional wire cages, on all wire slats, or on all...

  18. Potential for horizontal transmission of Salmonella and Campylobacter among caged and cage free laying hens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nine hens were inoculated orally and intravaginally with a marker strain of Salmonella and Campylobacter at 56 wk-of-age and housed in individual cages in isolation. Challenged hens were comingled with non-challenged hens 2 wk post-inoculation, at a ratio of 1 challenged hen per 4 non-challenged he...

  19. Laser-Modified Black Titanium Oxide Nanospheres and Their Photocatalytic Activities under Visible Light.

    PubMed

    Chen, Xing; Zhao, Dongxu; Liu, Kewei; Wang, Chunrui; Liu, Lei; Li, Binghui; Zhang, Zhenzhong; Shen, Dezhen

    2015-07-29

    A facile pulse laser ablation approach for preparing black titanium oxide nanospheres, which could be used as photocatalysts under visible light, is proposed. The black titanium oxide nanospheres are prepared by pulsed-laser irradiation of pure titanium oxide in suspended aqueous solution. The crystalline phases, morphology, and optical properties of the obtained nanospheres are characterized by means of X-ray diffraction (XRD), field-emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS), and UV-vis-NIR diffuse reflectance spectroscopy. It is shown that high-energy laser ablation of titanium oxide suspended solution benefited the formation of Ti(3+) species and surface disorder on the surface of the titanium oxide nanospheres. The laser-modified black titanium oxide nanospheres could absorb the full spectrum of visible light, thus exhibiting good photocatalytic performance under visible light. PMID:26132217

  20. Synthesis of C60(O)3: an open-cage fullerene with a ketolactone moiety on the orifice.

    PubMed

    Xin, Nana; Yang, Xiaobing; Zhou, Zishuo; Zhang, Jianxin; Zhang, Showxin; Gan, Liangbing

    2013-02-01

    Four isomers are currently known for the trioxygenated fullerene derivative C(60)(O)(3), three regioisomers with all of the oxygen addends as epoxy groups and the unstable ozonide isomer with a 1,2,3-trioxlane ring. Here we report the synthesis of an open-cage isomer for C(60)(O)(3) with a ketolactone moiety embedded into the fullerene skeleton through a three-step procedure mediated by fullerene peroxide chemistry. Two fullerene skeleton carbon-carbon bonds are cleaved in the process. The open-cage derivative C(60)(O)(3) can be converted back to C(60) through deoxygenation with PPh(3). Single crystal X-ray structure confirmed the open-cage structure. PMID:23311689

  1. Horizontal transmission of Salmonella and Campylobacter among caged and cage-free laying hens.

    PubMed

    Hannah, J F; Wilson, J L; Cox, N A; Richardson, L J; Cason, J A; Bourassa, D V; Buhr, R J

    2011-12-01

    In each of five sequential trials, laying hens (56-72 wk of age) were challenged with Salmonella and Campylobacter, and 1 wk postinoculation, the challenged hens (n = 3) were commingled with nonchallenged hens (n = 12) in conventional wire cages, on all-wire slats, or on all-shavings floor housing systems. After 12 days, challenged and nonchallenged hens were euthanatized for sample collection. Ceca were aseptically collected from all hens, and the spleen, liver/gallbladder (LGB), lower (LRT) and upper (URT) reproductive tracts, and ovarian follicles (mature and immature) were collected from only the challenged hens after commingling. Samples were divided equally and cultured separately for Salmonella and Campylobacter. Differences in the horizontal transmission of the challenge Salmonella to nonchallenged hens housed in cages (12%), on slats (15%), and on shavings (14%) were not significantly different (P > 0.05) from the challenged pen-mate hens over the five trials. However, with the inclusion of residual environmental Salmonella, the recovery of Salmonella from nonchallenged hens housed in cages was lowest at 15%, intermediate for hens on slats at 20%, and highest for hens on shavings at 38%. Among challenged hens housed in cages, Salmonella was recovered from only 27% of the cecum and LRT samples. From challenged hens housed on slats, Salmonella was recovered from 38% of the cecum, 12% of the spleen, 19% of the LGB, 44% of the LRT, and 19% of the URT samples. From challenged hens housed on shavings, Salmonella was recovered from 31% of the cecum; 15% of the spleen, LGB, and URT; and 31% of the LRT samples. Horizontal transmission of Campylobacter among nonchallenged pen-mate hens was significantly lower for hens housed in cages at 28% than for hens on shavings at 47%, with hens on slats being intermediate at 36%. For challenged hens housed in cages, Campylobacter was recovered from 27% of the cecum, 13% of the LRT, 7% of the URT, and 17% of the follicle

  2. Titanium by design: TRIP titanium alloy

    NASA Astrophysics Data System (ADS)

    Tran, Jamie

    Motivated by the prospect of lower cost Ti production processes, new directions in Ti alloy design were explored for naval and automotive applications. Building on the experience of the Steel Research Group at Northwestern University, an analogous design process was taken with titanium. As a new project, essential kinetic databases and models were developed for the design process and used to create a prototype design. Diffusion kinetic models were developed to predict the change in phase compositions and microstructure during heat treatment. Combining a mobility database created in this research with a licensed thermodynamic database, ThermoCalc and DICTRA software was used to model kinetic compositional changes in titanium alloys. Experimental diffusion couples were created and compared to DICTRA simulations to refine mobility parameters in the titanium mobility database. The software and database were able to predict homogenization times and the beta→alpha plate thickening kinetics during cooling in the near-alpha Ti5111 alloy. The results of these models were compared to LEAP microanalysis and found to be in reasonable agreement. Powder metallurgy was explored using SPS at GM R&D to reduce the cost of titanium alloys. Fully dense Ti5111 alloys were produced and achieved similar microstructures to wrought Ti5111. High levels of oxygen in these alloys increased the strength while reducing the ductility. Preliminary Ti5111+Y alloys were created, where yttrium additions successfully gettered excess oxygen to create oxides. However, undesirable large oxides formed, indicating more research is needed into the homogeneous distribution of the yttrium powder to create finer oxides. Principles established in steels were used to optimize the beta phase transformation stability for martensite transformation toughening in titanium alloys. The Olson-Cohen kinetic model is calibrated to shear strains in titanium. A frictional work database is established for common alloying

  3. Abrasion resistance of titanium nitride coatings formed on titanium by ion-beam-assisted deposition.

    PubMed

    Sawase, T; Yoshida, K; Taira, Y; Kamada, K; Atsuta, M; Baba, K

    2005-02-01

    To improve the physical properties of the pure titanium surface, thin titanium nitride (TiN) films were deposited by means of ion-beam-assisted deposition. Film structure was confirmed as TiN by X-ray diffraction analysis. Surface hardness and abrasion resistance were significantly improved on TiN-coated specimens. Five combinations of oral hygiene instruments and materials were applied to the specimens as simulations of the oral environment. Treatment with the metal scaler and ultrasonic scaler severely changed the surface features and significantly increased the surface roughness parameters on pure titanium controls, whereas only small scratches and dull undulations were seen on the TiN-coated specimens. Profilometric tracings and scanning electron micrographs demonstrated the improved abrasion resistance of the TiN-coated specimens. PMID:15641983

  4. Laser reactive ablation deposition of titanium nitride and titanium carbide films

    NASA Astrophysics Data System (ADS)

    D'Anna, Emilia; Leggieri, Gilberto; Luches, Armando; Martino, Maurizio; Perrone, Alessio; Majni, Guiseppe; Mengucci, Paolo; Mihailescu, Ion N.

    1994-11-01

    Titanium nitride and titanium carbide films were deposited on silicon substrates by XeCl excimer laser reactive ablation of titanium in nitrogen and methane atmospheres, respectively. A series of 10,000 pulses at the fluence of approximately 5 J/cm2 and repetition rate of 10 Hz were directed to the target. The pressure in the chamber was fixed, during every irradiation series, at a given value within the range 6 X 10-4 - 10 mbar of N2 or CH4. Very flat films with thickness exceeding 1 micrometers were deposited. The structural characteristics of the deposited films were investigated by Rutherford backscattering spectrometry, scanning electron microscopy, and by x-ray diffraction. Under specific experimental conditions very pure nitride films were deposited.

  5. 1/f Noise Inside a Faraday Cage

    SciTech Connect

    Handel, Peter H.; George, Thomas F.

    2009-04-23

    We show that quantum 1/f noise does not have a lower frequency limit given by the lowest free electromagnetic field mode in a Faraday cage, even in an ideal cage. Indeed, quantum 1/f noise comes from the infrared-divergent coupling of the field with the charges, in their joint nonlinear system, where the charges cause the field that reacts back on the charges, and so on. This low-frequency limitation is thus not applicable for the nonlinear system of matter and field in interaction. Indeed, this nonlinear system is governed by Newton's laws, Maxwell's equations, in general also by the diffusion equations for particles and heat, or reaction kinetics given by quantum matrix elements. Nevertheless, all the other quantities can be eliminated in principle, resulting in highly nonlinear integro-differential equations for the electromagnetic field only, which no longer yield a fundamental frequency. Alternatively, we may describe this through the presence of an infinite system of subharmonics. We show how this was proven early in the classical and quantum domains, adding new insight.

  6. Regenerating Titanium Ventricular Assist Device Surfaces after Gold/ Palladium Coating for Scanning Electron Microscopy

    PubMed Central

    Achneck, Hardean E.; Serpe, Michael J; Jamiolkowski, Ryan; Eibest, Leslie M.; Craig, Stephen L.; Lawson, Jeffrey H.

    2014-01-01

    Titanium is one of the most commonly used materials for implantable devices in human s. Scanning electron microscopy (SEM) serves as an important tool for imaging titanium surfaces and analyzing cells and other organic matter adhering to titanium implants. However, high-vacuum SEM imaging of a non-conductive sample requires a conductive coating on the surface. A gold/ palladium coating is commonly used and to date no method has been described to ‘clean’ such gold/ palladium covered surfaces for repeated experiments without etching the titanium itself. This constitutes a major problem with titanium based implantable devices which are very expensive and thus in short supply. Our objective was to devise a protocol to regenerate titanium surfaces after SEM analysis. In a series of experiments, titanium samples from implantable cardiac assist devices were coated with fibronectin, seeded with cells and then coated with gold/palladium for SEM analysis. X-ray photoelectron spectroscopy spectra were obtained before and after five different cleaning protocols. Treatment with aqua regia (a 1:3 solution of concentrated nitric and hydrochloric acid), with or without ozonolysis, followed by sonication in soap solution and sonication in deionized water, allowed regenerating titanium surfaces to their original state. Atomic force microscopy confirmed that the established protocol did not alter the titanium microstructure. The protocol described herein is applicable to almost all titanium surfaces used in biomedical sciences and because of its short exposure time to aqua regia, will likely work for many titanium alloys as well. PMID:19642216

  7. The Growth Behavior of Titanium Boride Layers in α and β Phase Fields of Titanium

    NASA Astrophysics Data System (ADS)

    Lv, Xiaojun; Hu, Lingyun; Shuang, Yajing; Liu, Jianhua; Lai, Yanqing; Jiang, Liangxing; Li, Jie

    2016-07-01

    In this study, the commercially pure titanium was successfully electrochemical borided in a borax-based electrolyte. The process was carried out at a constant cathodic current density of 300 mA cm-2 and at temperatures of 1123 K and 1223 K (850 °C and 950 °C) for 0.5, 1, 2, 3, and 5 hours. The growth behavior of titanium boride layers in the α phase field of titanium was compared with that in the β phase field. After boriding, the presence of both the TiB2 top layer and TiB whisker sub-layer was confirmed by the X-ray diffraction (XRD) and scanning electron microscope. The relationship between the thickness of boride layers and boriding time was found to have a parabolic character in both α and β phase fields of titanium. The TiB whiskers showed ultra-fast growth rate in the β phase field. Its growth rate constant was found to be as high as 3.2002 × 10-13 m2 s-1. Besides, the chemical resistance of the TiB2 layer on the surface of titanium substrate was characterized by immersion tests in molten aluminum.

  8. The Growth Behavior of Titanium Boride Layers in α and β Phase Fields of Titanium

    NASA Astrophysics Data System (ADS)

    Lv, Xiaojun; Hu, Lingyun; Shuang, Yajing; Liu, Jianhua; Lai, Yanqing; Jiang, Liangxing; Li, Jie

    2016-04-01

    In this study, the commercially pure titanium was successfully electrochemical borided in a borax-based electrolyte. The process was carried out at a constant cathodic current density of 300 mA cm-2 and at temperatures of 1123 K and 1223 K (850 °C and 950 °C) for 0.5, 1, 2, 3, and 5 hours. The growth behavior of titanium boride layers in the α phase field of titanium was compared with that in the β phase field. After boriding, the presence of both the TiB2 top layer and TiB whisker sub-layer was confirmed by the X-ray diffraction (XRD) and scanning electron microscope. The relationship between the thickness of boride layers and boriding time was found to have a parabolic character in both α and β phase fields of titanium. The TiB whiskers showed ultra-fast growth rate in the β phase field. Its growth rate constant was found to be as high as 3.2002 × 10-13 m2 s-1. Besides, the chemical resistance of the TiB2 layer on the surface of titanium substrate was characterized by immersion tests in molten aluminum.

  9. Adherence of sputtered titanium carbides

    NASA Technical Reports Server (NTRS)

    Brainard, W. A.; Wheeler, D. R.

    1979-01-01

    The study searches for interface treatment that would increase the adhesion of TiC coating to nickel- and titanium-base alloys. Rene 41 (19 wt percent Cr, 11 wt percent Mo, 3 wt percent Ti, balance Ni) and Ti-6Al-4V (6 wt percent Al, 4 wt percent V, balance Ti) are considered. Adhesion of the coatings is evaluated in pin-and disk friction tests. The coatings and interface regions are examined by X-ray photoelectron spectroscopy. Results suggest that sputtered refractory compound coatings adhere best when a mixed compound of coating and substrate metals is formed in the interfacial region. The most effective type of refractory compound interface appears to depend on both substrate and coating material. A combination of metallic interlayer deposition and mixed compound interface formation may be more effective for some substrate coating combinations than either alone.

  10. 48 CFR 204.7202-1 - CAGE codes.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... access to the Defense Logistics Agency (DLA) CAGE file through the DLA Network or dial-up capability; or... Logistics Information Service assigns or records and maintains CAGE codes to identify commercial and... Volume 7 of DoD 4100.39-M, Federal Logistics Information System (FLIS) Procedures Manual, prescribe...

  11. 48 CFR 204.7202-1 - CAGE codes.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... access to the Defense Logistics Agency (DLA) CAGE file through the DLA Network or dial-up capability; or... Logistics Information Service assigns or records and maintains CAGE codes to identify commercial and... Volume 7 of DoD 4100.39-M, Federal Logistics Information System (FLIS) Procedures Manual, prescribe...

  12. 48 CFR 204.7202-1 - CAGE codes.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... access to the Defense Logistics Agency (DLA) CAGE file through the DLA Network or dial-up capability; or... Logistics Information Service assigns or records and maintains CAGE codes to identify commercial and... Volume 7 of DoD 4100.39-M, Federal Logistics Information System (FLIS) Procedures Manual, prescribe...

  13. 48 CFR 204.7202-1 - CAGE codes.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... System for Award Management (SAM) database (see FAR subpart 4.11) and does not have a CAGE code, DLA... for registration in the SAM database. Foreign registrants must obtain a North Atlantic Treaty Organization CAGE (NCAGE) code in order to register in the SAM database. NCAGE codes may be obtained from...

  14. Self-assembly of highly luminescent heteronuclear coordination cages.

    PubMed

    Schmidt, Andrea; Hollering, Manuela; Han, Jiaying; Casini, Angela; Kühn, Fritz E

    2016-08-01

    Exo-functionalized Pd2L4 cage compounds with attached Ru(ii) pyridine complexes were prepared via coordination-driven self-assembly. Unlike most of the previously reported palladium(ii) cages, one of these metallocages exhibits an exceptionally high quantum yield of 66%. The presented approach is promising to obtain luminescent coordination complexes for various applications. PMID:27436541

  15. Problem Drinking Screening in College Students Using the CAGE.

    ERIC Educational Resources Information Center

    Heck, Edward J.; And Others

    The CAGE instrument is a 4-item questionnaire used for routine and rapid screening of alcohol problems. The term "CAGE" is an acronym with each letter representing one of the four items that comprise the instrument. A positive endorsement of two or more items is considered to be the threshold score, indicating the possibility of a drinking…

  16. Teaching in the Institutional Cage: Metaphor and Collateral Oppression

    ERIC Educational Resources Information Center

    Noël Smith, Becky L.

    2014-01-01

    This analysis is a philosophical exploration of Marilyn Frye's metaphor of the cage and Patricia Hill Collins' theory of intersecting oppressions. It argues that social structures and forms of oppressive knowledge make up the individual wires on each person's cage and that these work to confine individuals, particularly those in the…

  17. Polymers containing borane or carborane cage compounds and related applications

    DOEpatents

    Bowen, III, Daniel E.; Eastwood, Eric A.

    2012-06-05

    Polymers comprising residues of borane and/or carborane cage compound monomers having at least one polyalkoxy silyl substituent. Such polymers can further comprise one or more reactive matrices and/or co-monomers covalently bound with the cage compound monomer residues. Methods of making and applications for using such polymers are also disclosed.

  18. Abnormal Behavior in Relation to Cage Size in Rhesus Monkeys

    ERIC Educational Resources Information Center

    Paulk, H. H.; And Others

    1977-01-01

    Examines the effects of cage size on stereotyped and normal locomotion and on other abnormal behaviors in singly caged animals, whether observed abnormal behaviors tend to co-occur, and if the development of an abnormal behavior repertoire leads to reduction in the number of normal behavior categories. (Author/RK)

  19. Bearings use dry self-lubricating cage materials

    NASA Technical Reports Server (NTRS)

    Anderson, W. J.; Glenn, D. C.; Scribbe, H. W.

    1968-01-01

    Rolling element bearings in spacecraft mechanical systems use solid lubricant composites of polytetrafluoroethylene in the bearing cage which functions as the lubricant reservoir. The cage spaces the rolling elements equally and provides the lubricant at the bearing load-carrying surface.

  20. Morphosynthesis of cubic silver cages on monolithic activated carbon.

    PubMed

    Wang, Fei; Zhao, Hong; Lai, Yijian; Liu, Siyu; Zhao, Binyuan; Ning, Yuesheng; Hu, Xiaobin

    2013-11-14

    Cubic silver cages were prepared on monolithic activated carbon (MAC) pre-absorbed with Cl(-), SO4(2-), or PO4(3-) anions. Silver insoluble salts served as templates for the morphosynthesis of silver cages. The silver ions were reduced by reductive functional groups on MAC micropores through a galvanic cell reaction mechanism. PMID:24080952

  1. A Locust Cage and Hatchery from Plastic Aquarium Tanks

    ERIC Educational Resources Information Center

    Stoneman, C. F.; And Others

    1973-01-01

    Describes how to construct a locust cage from two plastic aquaria and four coffee jars with plastic lids. Its advantages over a conventional locust cage include the inexpensive cost, lack of breakable glass, ease of cleaning, and visibility from all angles. (JR)

  2. Caging Mechanism for a drag-free satellite position sensor

    NASA Technical Reports Server (NTRS)

    Hacker, R.; Mathiesen, J.; Debra, D. B.

    1976-01-01

    A disturbance compensation system for satellites based on the drag-free concept was mechanized and flown, using a spherical proof mass and a cam-guided caging mechanism. The caging mechanism controls the location of the proof mass for testing and constrains it during launch. Design requirements, design details, and hardware are described.

  3. Ammonia Levels and Urine-Spot Characteristics as Cage-Change Indicators for High-Density Individually Ventilated Mouse Cages.

    PubMed

    Washington, Ida M; Payton, Mark E

    2016-01-01

    Mouse cage and bedding changes are potentially stressful to mice and are also labor- and resource-intensive. These changes are often performed on a calendar-based schedule to maintain a clean microenvironment and limit the concentrations of ammonia to which mice and workers are exposed. The current study sought to establish a performance-based approach to mouse cage-changing that uses urine spot characteristics as visual indicators of intracage ammonia levels. Colorimetric ammonia indicators were used to measure ammonia levels in individually-ventilated cages (IVC) housing male or female mice (n =5 per cage) of various strains at 1 to 16 d after cage change. Urine spot characteristics were correlated with ammonia levels to create a visual indicator of the cage-change criterion of 25 ppm ammonia. Results demonstrated a consistent increase in ammonia levels with days since cage change, with cages reaching the cage-change criterion at approximately 10 d for IVC containing male mice and 16 d for those with female mice. Ammonia levels were higher for male than female mice but were not correlated with mouse age. However, urine spot diameter, color, and edge characteristics were strongly correlated with ammonia levels. Husbandry practices based on using urine spot characteristics as indicators of ammonia levels led to fewer weekly cage changes and concomitant savings in labor and resources. Therefore, urine spot characteristics can be used as visual indicators of intracage ammonia levels for use of a performance (urine spot)-based approach to cage-changing frequency that maintains animal health and wellbeing. PMID:27177558

  4. High-temperature oxidation of titanium silicide coatings on titanium

    SciTech Connect

    Abba, A.; Caillet, M.; Galerie, A.

    1982-02-01

    Coatings of Ti/sub 5/Si/sub 3/ on titanium have been prepared by means of decomposition of silane SiH/sub 4/ on heated titanium ribbons. Oxidation of the coated titanium specimens was much slower than that of the noncoated ones. Gravimetric and morphological experiments allowed to propose a mechanism describing the oxidation process.

  5. Titanium Cold Spray Coatings

    NASA Astrophysics Data System (ADS)

    Ajaja, Jihane; Goldbaum, Dina; Chromik, Richard; Yue, Stephen; Rezaeian, Ahmad; Wong, Wilson; Irissou, Eric; Legoux, Jean-Gabriel

    Titanium Cold Spray Coatings Cold Spray is an emerging technology used for the deposition of coatings for many industries including aerospace. This technique allows the deposition of metallic materials at low temper-atures below their melting point. The aim of this research was to develop a test technique that can measure the degree to which a cold spray coating achieves mechanical properties similar to a traditional bulk material. Vickers hardness testing and nanoindentation were used as micro-and nano-scale measurement techniques to characterize the mechanical properties of titanium coatings, deposited at different deposition conditions, and bulk Ti. The mechanical properties of bulk titanium and titanium coatings were measured over a range of length scales, with the indentation size effect examined with Meyer's law. Hardness measurements are shown to be affected by material porosity, microstructure and coating particle bonding mechanism. Hard-ness measurements showed that Ti coatings deposited at higher gas pressures and temperatures demonstrate an indentation load response similar to bulk Ti. Key words: titanium, cold spray, Vickers hardness, nanoindentation, indentation size effect, microstructure, mechanical properties

  6. Performance and welfare of rabbit does in various caging systems.

    PubMed

    Mikó, A; Matics, Zs; Gerencsér, Zs; Odermatt, M; Radnai, I; Nagy, I; Szendrő, K; Szendrő, Zs

    2014-07-01

    The objective of the study was to compare production and welfare of rabbit does and their kits housed in various types of cages. Female rabbits were randomly allocated to four groups with the following cage types: CN: common wire-mesh flat-deck cage, without footrest; CF: cage similar to the CN but with plastic footrest; ECWP: enlarged cage with wire-mesh platform; and ECPP: extra enlarged cage with plastic-mesh platform. All does were inseminated on the same day, 11 days after kindlings. Reproductive performance was evaluated during the first five consecutive kindlings. Severity of sore hocks was scored at each insemination. Location preference of the does and the platform usage of their kits were evaluated. Kindling rate, litter size (total born, born alive, alive at 21 and 35 days) and kit mortality were not significantly influenced by the cage types. The litter weight at 21 days was higher in ECWP and ECPP cages than in the CF group (3516, 3576 and 3291 g, respectively; P2.5 cm) and 3 to 4 (3=callus opened, cracks present; 4=wounds) were 58%, 60%, 78% and 48%, and 0%, 5%, 0% and 48% in groups ECPP, ECWP, CF and CN, respectively. Higher number of daily nest visits was observed for CF does than for ECWP does (12.5 v. 5.9; P2/day) was higher in the CF group than in the ECWP group (12.1 v. 3.2%; P<0.01). Within large cages, the does were observed on the platform more frequently in the ECPP cages compared with the ECWP cages (56.9% v. 31.7%; P<0.001). Similarly, 2.7% and 0.2% of kits at 21 days of age, and 33.2% and 5.2% of kits at 28 days of age, were found on the platforms of ECPP and ECWP cages, respectively. In conclusion, cages larger than the conventional ones improved kits' weaning weight, plastic footrests and plastic-mesh platforms in conventional and/or large cages reduced sore hocks' problems, plastic-mesh platforms were more used by both does and kits compared with the wire-mesh platforms. PMID:26263030

  7. Entropic cages for trapping DNA near a nanopore

    NASA Astrophysics Data System (ADS)

    Liu, Xu; Skanata, Mirna Mihovilovic; Stein, Derek

    2015-02-01

    Nanopores can probe the structure of biopolymers in solution; however, diffusion makes it difficult to study the same molecule for extended periods. Here we report devices that entropically trap single DNA molecules in a 6.2-femtolitre cage near a solid-state nanopore. We electrophoretically inject DNA molecules into the cage through the nanopore, pause for preset times and then drive the DNA back out through the nanopore. The saturating recapture time and high recapture probability after long pauses, their agreement with a convection-diffusion model and the observation of trapped DNA under fluorescence microscopy all confirm that the cage stably traps DNA. Meanwhile, the cages have 200 nm openings that make them permeable to small molecules, like the restriction endonuclease we use to sequence-specifically cut trapped DNA into fragments whose number and sizes are analysed upon exiting through the nanopore. Entropic cages thus serve as reactors for chemically modifying single DNA molecules.

  8. A Triphasic Sorting System: Coordination Cages in Ionic Liquids.

    PubMed

    Grommet, Angela B; Bolliger, Jeanne L; Browne, Colm; Nitschke, Jonathan R

    2015-12-01

    Host-guest chemistry is usually carried out in either water or organic solvents. To investigate the utility of alternative solvents, three different coordination cages were dissolved in neat ionic liquids. By using (19) F NMR spectroscopy to monitor the presence of free and bound guest molecules, all three cages were demonstrated to be stable and capable of encapsulating guests in ionic solution. Different cages were found to preferentially dissolve in different phases, allowing for the design of a triphasic sorting system. Within this system, three coordination cages, namely Fe4 L6 2, Fe8 L12 3, and Fe4 L4 4, each segregated into a distinct layer. Upon the addition of a mixture of three different guests, each cage (in each separate layer) selectively bound its preferred guest. PMID:26494225

  9. Caracterisation of Titanium Nitride Layers Deposited by Reactive Plasma Spraying

    NASA Astrophysics Data System (ADS)

    Roşu, Radu Alexandru; Şerban, Viorel-Aurel; Bucur, Alexandra Ioana; Popescu, Mihaela; Uţu, Dragoş

    2011-01-01

    Forming and cutting tools are subjected to the intense wear solicitations. Usually, they are either subject to superficial heat treatments or are covered with various materials with high mechanical properties. In recent years, thermal spraying is used increasingly in engineering area because of the large range of materials that can be used for the coatings. Titanium nitride is a ceramic material with high hardness which is used to cover the cutting tools increasing their lifetime. The paper presents the results obtained after deposition of titanium nitride layers by reactive plasma spraying (RPS). As deposition material was used titanium powder and as substratum was used titanium alloy (Ti6Al4V). Macroscopic and microscopic (scanning electron microscopy) images of the deposited layers and the X ray diffraction of the coatings are presented. Demonstration program with layers deposited with thickness between 68,5 and 81,4 μm has been achieved and presented.

  10. Eggshell bacterial levels of non-washed and washed eggs from caged and cage-free hens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The bacteria levels of non-washed and washed eggs obtained from caged and cage-free laying hens housed on either all shavings or all wire slat floors were determined. On eight sample days (from 22 to 52 weeks at 4 week intervals), 20 eggs were collected from each pen (n=120/sample day). Ten eggs p...