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Sample records for dynamic transpedicular stabilisation

  1. Skipping Posterior Dynamic Transpedicular Stabilization for Distant Segment Degenerative Disease

    Directory of Open Access Journals (Sweden)

    Bilgehan Solmaz

    2012-01-01

    Full Text Available Objective. To date, there is still no consensus on the treatment of spinal degenerative disease. Current surgical techniques to manage painful spinal disorders are imperfect. In this paper, we aimed to evaluate the prospective results of posterior transpedicular dynamic stabilization, a novel surgical approach that skips the segments that do not produce pain. This technique has been proven biomechanically and radiologically in spinal degenerative diseases. Methods. A prospective study of 18 patients averaging 54.94 years of age with distant spinal segment degenerative disease. Indications consisted of degenerative disc disease (57%, herniated nucleus pulposus (50%, spinal stenosis (14.28%, degenerative spondylolisthesis (14.28%, and foraminal stenosis (7.1%. The Oswestry Low-Back Pain Disability Questionnaire and visual analog scale (VAS for pain were recorded preoperatively and at the third and twelfth postoperative months. Results. Both the Oswestry and VAS scores showed significant improvement postoperatively (P<0.05. We observed complications in one patient who had spinal epidural hematoma. Conclusion. We recommend skipping posterior transpedicular dynamic stabilization for surgical treatment of distant segment spinal degenerative disease.

  2. Testing dynamic stabilisation in complex Langevin simulations

    CERN Document Server

    Attanasio, Felipe

    2016-01-01

    Complex Langevin methods have been successfully applied in theories that suffer from a sign problem such as QCD with a chemical potential. We present and illustrate a novel method (dynamic stabilisation) that ensures that Complex Langevin simulations stay close to the SU(3) manifold, which lead to correct and improved results in the framework of pure Yang-Mills simulations and QCD in the limit of heavy quarks.

  3. Posterior Transpedicular Dynamic Stabilization versus Total Disc Replacement in the Treatment of Lumbar Painful Degenerative Disc Disease: A Comparison of Clinical Results

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    Tunc Oktenoglu

    2013-01-01

    Full Text Available Study Design. Prospective clinical study. Objective. This study compares the clinical results of anterior lumbar total disc replacement and posterior transpedicular dynamic stabilization in the treatment of degenerative disc disease. Summary and Background Data. Over the last two decades, both techniques have emerged as alternative treatment options to fusion surgery. Methods. This study was conducted between 2004 and 2010 with a total of 50 patients (25 in each group. The mean age of the patients in total disc prosthesis group was 37,32 years. The mean age of the patients in posterior dynamic transpedicular stabilization was 43,08. Clinical (VAS and Oswestry and radiological evaluations (lumbar lordosis and segmental lordosis angles of the patients were carried out prior to the operation and 3, 12, and 24 months after the operation. We compared the average duration of surgery, blood loss during the surgery and the length of hospital stay of both groups. Results. Both techniques offered significant improvements in clinical parameters. There was no significant change in radiologic evaluations after the surgery for both techniques. Conclusion. Both dynamic systems provided spine stability. However, the posterior dynamic system had a slight advantage over anterior disc prosthesis because of its convenient application and fewer possible complications.

  4. A Novel Approach to the Surgical Treatment of Lumbar Disc Herniations: Indications of Simple Discectomy and Posterior Transpedicular Dynamic Stabilization Based on Carragee Classification

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    A. F. Ozer

    2013-01-01

    Full Text Available Surgery of lumbar disc herniation is still a problem since Mixter and Barr. Main trouble is dissatisfaction after the operation. Today there is a debate on surgical or conservative treatment despite spending great effort to provide patients with satisfaction. The main problem is segmental instability, and the minimally invasive approach via microscope or endoscope is not necessarily appropriate solution for all cases. Microsurgery or endoscopy would be appropriate for the treatment of Carragee type I and type III herniations. On the other hand in Carragee type II and type IV herniations that are prone to develop recurrent disc herniation and segmental instability, the minimal invasive techniques might be insufficient to achieve satisfactory results. The posterior transpedicular dynamic stabilization method might be a good solution to prevent or diminish the recurrent disc herniation and development of segmental instability. In this study we present our experience in the surgical treatment of disc herniations.

  5. Global stabilisation for a class of uncertain nonlinear time-delay systems by dynamic state and output feedback

    Science.gov (United States)

    Chai, Lin; Qian, Chunjiang

    2015-06-01

    This paper investigates the design problem of constructing the state and output feedback stabilisation controller for a class of uncertain nonlinear systems subject to time-delay. First, a dynamic linear state feedback control law with an adaptive strategy is developed to globally stabilise the uncertain nonlinear time-delay system under a lower-triangular higher-order growth condition. Then, one more challenging problem of the adaptive output feedback stabilisation is addressed, which can globally stabilise the time-delay system when the unmeasurable states linearly grow with rate functions consisting of higher-order output.

  6. Complex Langevin in Lattice QCD: dynamic stabilisation and the phase diagram

    CERN Document Server

    Aarts, Gert; Jäger, Benjamin; Sexty, Dénes

    2016-01-01

    Complex Langevin simulations provide an alternative to sample path integrals with complex weights and therefore are suited to determine the phase diagram of QCD from first principles. We use our proposed method of Dynamic Stabilisation (DS) to ensure improved convergence to the right limit and present new systematic tests of this technique. We also show results on QCD in the limit of heavy quarks and an analysis of DS compared to known results from reweighting.

  7. Adaptive robust stabilisation for a class of uncertain nonlinear time-delay dynamical systems

    Science.gov (United States)

    Wu, Hansheng

    2013-02-01

    The problem of adaptive robust stabilisation is considered for a class of uncertain nonlinear dynamical systems with multiple time-varying delays. It is assumed that the upper bounds of the nonlinear delayed state perturbations are unknown and that the time-varying delays are any non-negative continuous and bounded functions which do not require that their derivatives have to be less than one. In particular, it is only required that the nonlinear uncertainties, which can also include time-varying delays, are bounded in any non-negative nonlinear functions which are not required to be known for the system designer. For such a class of uncertain nonlinear time-delay systems, a new method is presented whereby a class of continuous memoryless adaptive robust state feedback controllers with a rather simpler structure is proposed. It is also shown that the solutions of uncertain nonlinear time-delay systems can be guaranteed to be uniformly exponentially convergent towards a ball which can be as small as desired. Finally, as an application, an uncertain nonlinear time-delay ecosystem with two competing species is given to demonstrate the validity of the results.

  8. Predator-prey dynamics stabilised by nonlinearity explain oscillations in dust-forming plasmas

    Science.gov (United States)

    Ross, A. E.; McKenzie, D. R.

    2016-04-01

    Dust-forming plasmas are ionised gases that generate particles from a precursor. In nature, dust-forming plasmas are found in flames, the interstellar medium and comet tails. In the laboratory, they are valuable in generating nanoparticles for medicine and electronics. Dust-forming plasmas exhibit a bizarre, even puzzling behaviour in which they oscillate with timescales of seconds to minutes. Here we show how the problem of understanding these oscillations may be cast as a predator-prey problem, with electrons as prey and particles as predators. The addition of a nonlinear loss term to the classic Lotka-Volterra equations used for describing the predator-prey problem in ecology not only stabilises the oscillations in the solutions for the populations of electrons and particles in the plasma but also explains the behaviour in more detail. The model explains the relative phase difference of the two populations, the way in which the frequency of the oscillations varies with the concentration of the precursor gas, and the oscillations of the light emission, determined by the populations of both species. Our results demonstrate the value of adopting an approach to a complex physical science problem that has been found successful in ecology, where complexity is always present.

  9. Thoracolumbar spinal fractures : radiological results of transpedicular fixation combined with transpedicular cancellous bone graft and posterior fusion in 183 patients

    NARCIS (Netherlands)

    Leferink, VJM; Zimmerman, KW; Veldhuis, EFM; ten Vergert, EM; ten Duis, HJ

    2001-01-01

    In internal posterior fixation of thoracolumbar fractures combined with transpedicular cancellous bone graft and posterior fusion of the intervertebral facet joints at the level of the destroyed end plate it is still uncertain as to whether significant vertebral body collapse and loss of correction

  10. Morphological character of cervical spine for anterior transpedicular screw fixation

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    Rong-Ping Zhou

    2013-01-01

    Full Text Available Background: Anterior cervical interbody grafts/cages combined with a plate were frequently used in multilevel discectomies/corpectomies. In order to avoid additional posterior stabilization in patients who undergo anterior reconstructive surgery, an anterior cervical transpedicular screw fixation, which offers higher stability is desirable. We investigated in this study the anatomical (morphologic characters for cervical anterior transpedicular screw fixation. Materials and Methods: Left pedicle parameters were measured on computed tomography (CT images based on 36 cervical spine CT scans from healthy subjects. The parameters included outer pedicle width (Distance from lateral to medial pedicle surface in the coronal plane, outer pedicle height (OPH (Distance from upper to lower pedicle surface in the sagittal plane, maximal pedicle axis length (MPAL, distance transverse insertion point (DIP, distance of the insertion point to the upper end plate (DIUP, pedicle sagittal transverse angle (PSTA and pedicle transverse angle (PTA at C3 to C7. Results: The values of outer pedicle width and MPAL in males were larger than in females from C3 to C7. The OPH in males was larger than in females at C3 to C6, but there was no difference at C7. The DIP and PTA were significantly greater in males than in females at C3, but there was no difference in the angle at C4-7. The PSTA was not statistically different between genders at C3, 4, 7, but this value in males was larger than females at C5, 6. The DIUP was significantly greater in males at C3, 4, 6, 7 but was non significant at C5. Conclusions: The placement of cervical anterior transpedicular screws should be individualized for each patient and based on a detailed preoperative planning.

  11. SURVEY SUBAXIAL CERVICAL VERTEBRAE FOR TRANSPEDICULAR SCREW FIXATION

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Objective In this study, the pedicles of subaxial vertebrae from C3 to C7 were measured to provide some morphometric data for cervical transpedicular screw fixation. Methods 20 dried bone cervical spinal columns (C3-C7), pedicle dimensions (pedicle height, width, length), and transverse and sagittal angles of the pedicles were performed with vernier in linear and angular measurements. Results The obtained data revealed that the mean values were approximately ranging from 6.7 to 7.2 mm for pedicle height, 4.4 to 4.9 mm for pedicle width, 22.2 to 27.7 mm for pedicle axis length, 42.3° to 51.5° for transverse angle, and 5.2° to 14.1° for sagittal angle. Conclusion Linear measurements of pedicle dimensions and also axial angles from horizontal and vertical planes may provide some anatomic limitations for subaxial cervical transpedicular screw fixation, and also contribute to the safety of the surgical procedure.

  12. Evaluacion de la biopsia transpedicular guiada por TAC Avaliação da biópsia transpedicular guiada por TC Evaluation of transpedicular percutaneous biopsy guided by CT

    OpenAIRE

    Luis Miguel Rosales Olivarez; Hugo Rolando Nieto Sandoval; Armando Alpízar Aguirre; Barón Zárate Kalfopulos; María Guadalupe Sánchez Bringas; Alejandro Antonio Reyes Sánchez

    2012-01-01

    OBJETIVO: Valorar la utilidad de la biopsia transpedicular percutánea guiada por Tomografía Axial Computarizada en conjunto con la sistematización de estudios como pruebas diagnósticas de la etiología de la destrucción vertebral. MÉTODOS: Estudio de serie de casos prospectivo transversal de 21 pacientes a los que se les realizó biopsia transpedicular percutánea guiada por Tomografía Axial Computarizada y estudios de laboratorio y gabinete de marzo a julio del 2011, para evaluar su utilidad en...

  13. Variation of the residual resistivity ratio of the aluminium stabiliser for the Compact Muon Solenoid (CMS) conductor under dynamic stress at 4.2 K

    CERN Document Server

    Seeber, B; Flükiger, R; Horváth, I L; Neuenschwander, J

    2000-01-01

    Superconducting detector magnets are frequently manufactured with aluminium stabilised NbTi cables. Actually there are two new detectors in fabrication, namely the CMS and the ATLAS detector at CERN in Geneva, Switzerland. For the CMS project we have studied the variation of the residual resistivity ratio (RRR) of high purity aluminium (HPA) (99.998%) under dynamic mechanical stress, applied at 4.2 K, and in a transverse magnetic field of up to 6 T. This information is required for the design of the quench protection system. Because of the mechanical weakness of HPA, a high strength aluminium (HSA) alloy reinforces the CMS-conductor. According to the specification for CMS, the conductor at maximum field is strained up to 0.15%. At this strain the HSA is still in the elastic regime, whereas the HPA is already deformed plastically. Applying a full stress cycle (e.g. loading and unloading of the magnet), the HPA is deformed first under tension and then under compression, resulting in a decrease of the RRR. For m...

  14. External transpedicular spine fixation in severe spondylodiscitis – salvage procedure

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    Spalteholz, Matthias

    2013-11-01

    Full Text Available Specific and non-specific infections of the spine are rare. Due to their potential for severe instabilities, deformities and the impairment of neurological structures, the treatment is often prolonged and needs an interdisciplinary management. The clinical presentation is uncharacteristic, therefore diagnosis is often delayed. There are no prospective randomized studies for therapy recommendation. The surgical concept includes eradication of the infection and the reliable stabilization of involved segments. This concept is successful in most cases of endogenous vertebral osteomyelitis. The therapy of the exogenous spine infections after macro and micro surgery is more difficult, due to the critical wound situation and the involvement of the posterior parts of the spine. In these cases, infection-associated instability of the anterior part is complicated by critical posterior wound conditions.We present three cases of severe exogenous vertebral infections, where temporary external transpedicular spine fixation was used for salvage procedure, till soft tissue conditions have permitted a definitive internal stabilization.

  15. Application of posterior Moss-Miami transpedicular system for the treatment of adolescent idiopathic scoliosis

    Institute of Scientific and Technical Information of China (English)

    ZHU Xiao-dong; LI Ming; ZHANG Qi; HOU Tie-sheng; HE Shi-sheng

    2007-01-01

    Objective:To determine the effectiveness of posterior Moss-Miami transpedicular system for the treatment of adolescent idiopathic scoliosis in 24 patients with a 2-year minimum follow up. Methods:24 patients who underwent operations between September 2002 and November 2003 were evaluated for curve correction, spinal balance, and complications. Age at surgery averaged 13.8 years (range from 10 to20). The spinal deformities were evaluated by Cobb method with anteroposterior and lateral bending radiographs. All patients were right thoracic curves. Posterior instrumentation (Moss-Miami transpedicular system) was used. The transpedicular screws were placed between T2 and L2. All the patients were assessed both clinically and radiographically. Follow-up averaged 2.8 years. Results: There was an average correction of 72% of the primary curve (pre-operation standing average 54 degrees (range from 40 to 67degrees), post-operation average 15.2 degrees (range from 2 to 27 degrees), at last examination average 16.1 degrees (range from 2 to 30 degrees). Infection and neurological complications were not noted. No major complications were observed. Conclusions: Frontal and sagittal thoracic curve correction of thoracic scoliosis can be satisfactorily obtained using Moss Miami transpedicular instrumentation. It seems that control of the three columns of the spine by the transpedicular screws offers sufficient apical translation and coronal realignment.

  16. Percutaneous coaxial transpedicular biopsy of vertebral body lesions during vertebroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Minart, D.; Vallee, J.N.; Cormier, E.; Chiras, J. [Service de Neuroradiologie Diagnostique et Interventionnelle Charcot, Groupe Hospitalo-Universitaire Pitie-Salpetriere, Paris (France)

    2001-05-01

    We evaluated the safety and histological results of percutaneous transpedicular biopsy in patients undergoing vertebroplasty for vertebral collapse. Over a 6 year period, we carried out biopsies in 46 patients who underwent percutaneous injection of acrylic surgical cement for 57 collapsed vertebrae, because the diagnosis was not clearly established on clinical or imaging grounds. All procedures were performed under fluoroscopic guidance via a coaxial bitranspedicular approach used for vertebroplasty. We performed a clinical examination and CT after every procedure and approximately 6 months thereafter. Biopsies contributed to in 55 (96.5 %) of the 57 vertebral lesions. Biopsy material was inadequate in one case (1.7 %) and one biopsy was a false-negative (1.7 %). The accuracy of the histological results was 98.2 %, allowing a correct diagnosis in 55 of the 56 procedures. Of the 37 lesions in 28 patients with a history of a tumour, the final diagnosis was osteoporotic collapse in 25 (67.6 %), metastasis in nine (24.3 %), and myeloma in three (8.1 %). The final diagnosis in the 19 lesions in 17 patients without a known tumour was osteoporotic collapse in 12 (63.2 %), metastasis in five (26.3 %), and amyloidosis in two (10.5 %), the latter in one patient. No complications were observed. (orig.)

  17. Improved Accuracy and Safety of Intracorporeal Transpedicular Bone Grafting - using Contrast Impregnated Bone: A Case Report

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    CK Chiu

    2014-11-01

    Full Text Available A method of transpedicular bone grafting using contrast impregnated bone to improve the visualization of bone graft on the image intensifier is reported. A - 36-year old man who had sustained traumatic burst fracture of T12 vertebra, with Load-Sharing Classification (LSC score of 8, was treated with posterior short segment fusion from T11 to L1 with transpedicular bone graft of T12 vertebra. We were able to correct the kyphotic end plate angle (EPA from 19º to 1.4º. Anterior bone graft augmentation was achieved with contrast enhaced transpedicular bone grafts. At six months follow up, CT scan showed good bony integration of the anterior column with EPA of 4.5º and two years later, radiographs showed EPA of 7.6 º.

  18. Relative Prices and Inflation Stabilisation

    OpenAIRE

    Aoki, Kosuke

    2015-01-01

    When price adjustment is sluggish, inflation is costly in terms of welfare because it distorts various kinds of relative prices. Stabilising aggregate price inflation does not necessarily minimise these costs, but stabilising a well-designed core inflation minimises the cost of relative price fluctuations and thus the cost of inflation.

  19. Stabilising springs for fixed lingual retainer.

    Science.gov (United States)

    Karthikeyan, M K; Ramachandraprabhakar; Saravanan, R; Rajvikram, N; Kuppuchamy

    2013-11-01

    Most treated malocclusion needs fixed lingual retention. To stabilise fixed lingual retainer in the exact location needs proper stabilisation. Proper stabilization requires a holding spring. This Stabilising Spring should be easy to fabricate and help the clinician to stabilise the retainer quickly and save the chair side time. More over it should not irritate the mucosa and should be easy to insert and remove.

  20. Evaluation of Outcome of Transpedicular Decompression and Instrumented Fusion in Thoracic and Thoracolumbar Tuberculosis

    Science.gov (United States)

    Jain, R.K.; Kiyawat, Vivek

    2017-01-01

    Study Design Retrospective analysis. Purpose We evaluated the functional, neurological, and radiological outcome in patients with thoracic and thoracolumbar tuberculosis operated through the transpedicular approach. Overview of Literature For surgical treatment of thoracic and thoracolumbar tuberculosis, the anterior approach has been the most popular because it allows direct access to the infected tissue, thereby providing good decompression. However, anterior fixation is not strong, and graft failure and loss of correction are frequent complications. The transpedicular approach allows circumferential decompression of neural elements along with three-column fixation attained via pedicle screws by the same approach. Methods A total of 47 patients were diagnosed with tuberculosis of the thoracic or thoracolumbar region from August 2012 to August 2013. Of these, 28 patients had progressive neurological deterioration or increasing back pain despite conservative measures and underwent transpedicular decompression and pedicle screw fixation with posterior fusion. Antituberculosis therapy was given till signs of radiological healing were evident (9–16 months). Functional outcome (visual analog scale [VAS] score for back pain), neurological recovery (Frankel grading), and radiological improvement were evaluated preoperatively, immediate postoperatively, and at 3 months, 6 months, and 1 year. Results Mean VAS score for back pain improved from 8.7 preoperatively to 1.1 at 1 year follow-up. Frankel grading preoperatively was grade B in 7, grade C in 11, and Grade D in 10 patients, which improved to grade D in 6 and grade E in 22 patients at the last follow-up. Radiological healing was evident in the form of reappearance of trabeculae formation, resolution of pus, fatty marrow replacement, and bony fusion in all patients. Mean correction of segmental kyphosis postoperatively was 10.5°. Mean loss of correction at final follow-up was 4.1°. Conclusions Transpedicular

  1. Evaluacion de la biopsia transpedicular guiada por TAC Avaliação da biópsia transpedicular guiada por TC Evaluation of transpedicular percutaneous biopsy guided by CT

    Directory of Open Access Journals (Sweden)

    Luis Miguel Rosales Olivarez

    2012-09-01

    Full Text Available OBJETIVO: Valorar la utilidad de la biopsia transpedicular percutánea guiada por Tomografía Axial Computarizada en conjunto con la sistematización de estudios como pruebas diagnósticas de la etiología de la destrucción vertebral. MÉTODOS: Estudio de serie de casos prospectivo transversal de 21 pacientes a los que se les realizó biopsia transpedicular percutánea guiada por Tomografía Axial Computarizada y estudios de laboratorio y gabinete de marzo a julio del 2011, para evaluar su utilidad en el diagnóstico de destrucción vertebral. RESULTADOS: Fueron 21 pacientes, 14 hombres y 7 mujeres, con edad media de 59,2 años, cuyos niveles más afectados estuvieron en L1, L2 y L3. El reporte de la biopsia tuvo una precisión diagnóstica del 90,4%. En 2 casos se realizó correlación clínica entre biopsia y sistematización de estudios para obtener el diagnóstico. CONCLUSIÓN: La biopsia guiada por Tomografía Axial Computarizada es una técnica sencilla, útil, de bajo costo y eficaz en el estudio de la destrucción vertebral; la sistematización de estudios permite corroborar el diagnóstico de la biopsia.OBJETIVO: Avaliar a utilidade da biópsia transpedicular percutânea guiada por tomografia axial computadorizada em conjunto com a sistematização de estudos, como exames diagnósticos da etiologia da destruição vertebral. MÉTODOS: Estudo de série de casos, prospectivo e transversal de 21 pacientes submetidos à biópsia transpedicular percutânea guiada por tomografia axial computadorizada e exames laboratoriais e radiológicos, de março a julho de 2011, para avaliar sua utilidade no diagnóstico de destruição vertebral. RESULTADOS: Foram analisados 21 pacientes, 14 homens e 7 mulheres, com média de idade de 59,2 anos, cujos níveis mais afetados foram L1, L2 e L3. O laudo da biópsia teve precisão diagnóstica de 90,4%. Em dois casos, realizou-se a correlação clínica entre biópsia e sistematização de exames para obter

  2. CLIC Drive Beam Phase Stabilisation

    CERN Document Server

    Gerbershagen, Alexander; Schulte, Daniel

    The thesis presents phase stability studies for the Compact Linear Collider (CLIC) and focuses in particular on CLIC Drive Beam longitudinal phase stabilisation. This topic constitutes one of the main feasibility challenges for CLIC construction and is an essential component of the current CLIC stabilisation campaign. The studies are divided into two large interrelated sections: the simulation studies for the CLIC Drive Beam stability, and measurements, data analysis and simulations of the CLIC Test Facility (CTF3) Drive Beam phase errors. A dedicated software tool has been developed for a step-by-step analysis of the error propagation through the CLIC Drive Beam. It uses realistic RF potential and beam loading amplitude functions for the Drive and Main Beam accelerating structures, complete models of the recombination scheme and compressor chicane as well as of further CLIC Drive Beam modules. The tool has been tested extensively and its functionality has been verified. The phase error propagation at CLIC h...

  3. Transpedicular endoscopic surgery for lumbar spinal synovial cyst-report of two cases.

    Science.gov (United States)

    Krzok, Guntram; Telfeian, Albert E; Wagner, Ralf; Iprenburg, Menno

    2016-12-01

    Lumbar facet cysts are a benign, degenerative, and fairly uncommon cause for lumbar radiculopathy. The standard surgical treatment for lumbar facet cysts often requires a laminectomy and medial facetectomy which can further destabilize a pathological motion segment. The authors present here a novel technique for transpedicular endoscopic access to the pathology that obviates the need to violate the lamina or facet. Two patient cases are described where the lumbar 4-5 facet cysts arise medial to the pedicle. Percutaneous access to the cysts was established by drilling through the adjacent pedicle creating a 7-mm corridor to establish access for the endoscopic tubular retractor and the working channel endoscope. Straight and bendable forceps were used to remove the cysts under direct visualization. Following surgery, the patients' symptoms showed immediate regression with complete relief of one patient's foot drop by 6 months. Transpedicular endoscopic access is described as novel minimally invasive surgical option in the awake patient for lumbar facet cysts adjacent to the Lumbar 4 or 5 pedicle.

  4. Posterior interbody fusion using a diagonal cage with unilateral transpedicular screw fixation for lumbar stenosis.

    Science.gov (United States)

    Zhao, Jian; Zhang, Feng; Chen, Xiaoqing; Yao, Yu

    2011-03-01

    Few reports have described the combined use of unilateral pedicle screw fixation and interbody fusion for lumbar stenosis. We retrospectively reviewed 79 patients with lumbar stenosis. The rationale and effectiveness of unilateral pedicle screw fixation were studied from biomechanical and clinical perspectives, aiming to reduce stiffness of the implant. All patients were operated with posterior interbody fusion using a diagonal cage in combination with unilateral transpedicular screw fixation and had reached the 3-year follow-up interval after operation. The mean operating time was 115 minutes (range=95-150 min) and the mean estimated blood loss was 150 mL (range=100-200 mL). The mean duration of hospital stay was 10 days (range=7-15 days). Clinical outcomes were assessed prior to surgery and reassessed at intervals using Denis' pain and work scales. Fusion status was determined from X-rays and CT scans. At the final follow-up, the clinical results were satisfactory and patients showed significantly improved scores (pdiagonal cage with unilateral transpedicular fixation is an effective treatment for decompressive surgery for lumbar stenosis.

  5. Mycorrhizal aspects in slope stabilisation

    Science.gov (United States)

    Graf, Frank

    2016-04-01

    In order to re-colonise and stabilise slopes affected by superficial soil failure with plants essential requirements have to be met: the plants must grow the plants must survive sustainably plant succession must start and continuously develop These requirements, however, are anything but easy given, particularly under the often hostile environmental conditions dominating on bare and steep slopes. Mycorrhizal fungi, the symbiotic partners of almost all plants used in eco-engineering, are said to improve the plants' ability to overcome periods governed by strongly (growth) limiting factors. Subsequently, results of investigations are presented of mycorrhizal effects on different plant and soil functions related to eco-engineering in general and soil and slope stabilisation in particular. Generally, inoculation yielded higher biomass of the host plants above as well as below ground. Furthermore, the survival rate was higher for mycorrhized compared to non-mycorrhized plants, particularly under extreme environmental conditions. However, the scale of the mycorrhizal impact may be species specific of both the plant host as well as the fungal partner(s) and often becomes evident only after a certain time lag. Depending on the plant-fungus combination the root length per soil volume was found to be between 0 and 2.5 times higher for inoculated compared to non-inoculated specimens. On an alpine graded ski slope the survival of inoculated compared to non-treated Salix herbacea cuttings was significant after one vegetation period only for one of the three added mycorrhizal fungus species. However, after three years all of the inoculated plantlets performed significantly better than the non-inoculated controls. The analysis of the potential for producing and stabilising soil aggregates of five different ectomycorrhizal fungi showed high variation and, for the species Inocybe lacera, no significant difference compared to untreated soil. Furthermore, inoculation of Salix

  6. Two additional augmenting screws with posterior short-segment instrumentation without fusion for unstable thoracolumbar burst fracture – Comparisons with transpedicular grafting techniques

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    Yu-Chih Lin

    2016-12-01

    Conclusions: Compared with transpedicular grafting techniques, additional two “augmenting screws” in the fracture vertebra with short-segment instrumentation are sufficient for one-level thoracolumbar burst fracture.

  7. Preliminary stabilisation of stormwater biofilters and loss of filter material.

    Science.gov (United States)

    Subramaniam, D N; Mather, P B

    Stabilisation affects performance of stormwater biofilters operating under intermittent wetting and drying, mainly due to wash-off of filter material. Understanding the dynamics of solids wash-off is crucial in designing stormwater biofilters. The current study analysed the dynamics of solids wash-off in stormwater biofilters and quantified the loss of solids from the filter. Four Perspex™ bioretention columns (94 mm internal diameter) were fabricated with a filter layer that contained 8% organic material and were fed with tap water with different numbers of antecedent dry days (0-40 day) at 100 mL/min. Samples were collected from the outflow and tested for particle size distribution and total solids and turbidity. Solids of particle size less than 50 microns were washed off from the filter during the stabilisation period, indicating that no sand particles were washed off. The very first event after commissioning the filter resulted in the highest wash-off of solids (approximately 75 g of fines) while a significant drop in wash-off followed from the second event. An empirical model fitted to the data showed that preliminary stabilisation of a filter occurs in the first three events, during which almost 25% of fines are lost from the filter.

  8. Mean square stabilisation of complex oscillatory regimes in nonlinear stochastic systems

    Science.gov (United States)

    Bashkirtseva, Irina; Ryashko, Lev

    2016-04-01

    A problem of stabilisation of the randomly forced periodic and quasiperiodic modes for nonlinear dynamic systems is considered. For this problem solution, we propose a new theoretical approach to consider these modes as invariant manifolds of the stochastic differential equations with control. The aim of the control is to provide the exponential mean square (EMS) stability for these manifolds. A general method of the stabilisation based on the algebraic criterion of the EMS-stability is elaborated. A constructive technique for the design of the feedback regulators stabilising various types of oscillatory regimes is proposed. A detailed parametric analysis of the problem of the stabilisation for stochastically forced periodic and quasiperiodic modes is given. An illustrative example of stochastic Hopf system is included to demonstrate the effectiveness of the proposed technique.

  9. Reset stabilisation of positive linear systems

    Science.gov (United States)

    Zhao, Xudong; Yin, Yunfei; Shen, Jun

    2016-09-01

    In this paper, the problems of reset stabilisation for positive linear systems (PLSs) are investigated. Some properties relating to reset control of PLSs are first revealed. It is shown that these properties are different from the corresponding ones of general linear systems. Second, a class of periodic reset scheme is designed to exponentially stabilise an unstable PLS with a prescribed decay rate. Then, for a given PLS with reset control, some discussions on the upper bound of its decay rate are presented. Meanwhile, the reset stabilisation for PLSs in a special case is probed as well. Finally, two numerical examples are used to demonstrate the correctness and effectiveness of the obtained theoretical results.

  10. Accuracy and complications of transpedicular C2 screw placement without the use of spinal navigation.

    Science.gov (United States)

    Mueller, Christian-Andreas; Roesseler, Lukas; Podlogar, Martin; Kovacs, Attlila; Kristof, Rudolf Andreas

    2010-05-01

    The objective of the study was to describe the technique, accuracy of placement and complications of transpedicular C2 screw fixation without spinal navigation. Patients treated by C2 pedicle screw fixations were identified from the surgical log book of the department. Clinical data were extracted retrospectively from the patients' charts. Pedicle screw placement accuracy was assessed on postoperative CT scans according to Gertzbein and Robbins (GRGr). A total of 27 patients were included in the study. The mean age of the patients was 56 +/- 22.0 years; 51.9% of them were female. As much as 17 patients suffered from trauma, 5 of degenerative disease, 3 of inflammations and 2 of metastatic disease. A total of 47 C2 transpedicular screw fixations were performed. The canulated screws were inserted under visual control following the preparation of the superior surface of the isthmus and of the medial surface of the pedicles of the C2. Intraoperative fluoroscopy was additionally used. The postoperative CT findings showed in 55.3% GRGr 1, in 27.7% GRGr 2, in 10.6% GRGr 3, and in 6.3% GRGr 4 pedicle screw insertion accuracy. Screw insertions GRGr 5 were not observed. Screw malpositioning (i.e., GRGr 3 and 4) was significantly associated with thin (C2 fractures. In the three patients with screw insertions GRGr 4, postoperative angiographies were performed to exclude vertebral artery affections. In one of these three cases, the screw caused a clinically asymptomatic vertebral artery compression. Hardware failures did not occur. In one patient, postoperative pneumonia resulted in the death of the patient. Careful patient selection and surgical technique is necessary to avoid vertebral artery injury in C2 pedicle screw fixation without spinal navigation. A slight opening of the vertebral artery canal (Gertzbein and Robbins grade C2 pedicle screw insertions.

  11. Modelo simulador para treinamento de punção transpedicular em vertebroplastia percutânea Manikin-type training simulator model for transpedicular puncture in percutaneous vertebroplasty

    Directory of Open Access Journals (Sweden)

    Nitamar Abdala

    2007-08-01

    Full Text Available OBJETIVO: Desenvolver e testar a similaridade de modelo de coluna lombar tipo manequim para treinamento de punção transpedicular em vertebroplastia percutânea. MATERIAIS E MÉTODOS: Foram confeccionadas 30 vértebras lombares à base, principalmente, de metacrilato, gesso e etil-vinil-acetato, a partir de molde de borracha baseado em vértebra humana. Os discos intervertebrais foram feitos com silicone para que houvesse similaridade anatômica e fusão de cinco vértebras. O segmento da coluna foi acondicionado no interior de um manequim coberto por tela de etil-vinil-acetato para que não fosse possível a visualização direta. Foi realizado curso teórico para seis especializandos de radiologia e neurorradiologia, que testaram o modelo para vários parâmetros de similaridade com a realidade, realizando 30 punções transpediculares, em três sessões de dez procedimentos por dia, com intervalo de uma semana entre cada sessão. RESULTADOS: Cada aluno realizou 30 punções transpediculares, porém oito punções foram desconsideradas, pois se observaram problemas de manufatura dos modelos durante estes procedimentos. Após a realização das punções, todos os participantes preencheram o formulário de similaridade, com 100% de respostas positivas em relação à similaridade do modelo. CONCLUSÃO: Foi possível o desenvolvimento de modelo para punção transpedicular com similaridade satisfatória com o ser humano, configurando um instrumento de treinamento de vertebroplastia.OBJECTIVE: To develop and test a model of the human lumbar vertebra for training transpedicular puncture in percutaneous vertebroplasty. MATERIALS AND METHODS: Thirty lumbar vertebra models were constructed from methacrylate, plaster and ethyl-vinyl-acetate, using a rubber mold of human vertebrae. The intervertebral discs were made of silicone to provide anatomical similarity and fusion of five vertebrae. This model of spinal column segment was positioned within a

  12. Launch Stabilisation System for Vertical Launch of a Missile

    Directory of Open Access Journals (Sweden)

    K. Sreekumar

    2005-07-01

    Full Text Available The launch platform stabilisation control system is a roll-pitch stabilised platform for the vertical launch of a missile from a naval ship. Stabilisation of the launch platform is achievedwith the help of embedded controllers and electro-hydraulic servo control system. The launch platform is stabilised wrt true horizontal with a 2-axis (roll and pitch stabilisation systemconsisting of a gimbal and a set of three high-pressure servo hydraulic actuators. The control system uses rate gyro and tilt sensor feedbacks for stabilising the platform. This paper outlines the details of the launch platform stabilisation control system, results of digital simulation, and the performance during sea trials.

  13. Non-overshooting stabilisation via state and output feedback

    Science.gov (United States)

    Halikias, G.; Papageorgiou, A.; Karcanias, N.

    2010-06-01

    The concept of 'strong stability' of linear time-invariant (LTI) systems has been introduced in a recent paper (Karcanias, N., Halikias, G., and Papageorgiou, A. (2010), 'Strong Stability of Internal System Descriptions', International Journal of Control, 83, 182-205). This is a stronger notion of stability compared to alternative definitions (e.g. stability in the sense of Lyapunov, asymptotic stability), which allows the analysis and design of control systems with non-overshooting response in the state-space for arbitrary initial conditions. This article reviews the notion of 'strong stability' (Karcanias et al. 2010) and introduces the problem of non-overshooting stabilisation. It is shown that non-overshooting stabilisation under dynamic and static output feedback are, in a certain sense, equivalent problems. Thus, we turn our attention to static non-overshooting stabilisation problems under state-feedback, output injection and output feedback. After developing a number of preliminary results, we give a geometric interpretation to the problem in terms of the intersection of an affine hyperplane and the interior of an open convex cone. A solution to the problem is finally obtained via linear matrix inequalities, along with the complete parameterisation of the optimal solution set.

  14. The self-stabilising dynamics of bicycles

    CERN Document Server

    Warner, Mark

    2010-01-01

    We analyse the classical problem of the stability of bicycles when moving quickly and upright. Developing a lean causes the front wheel to turn thereby setting the bicycle instantaneously into circular motion. The centripetal force associated with the lean-dependent turning circle gives a restoring torque which corrects the lean. The force also helps self-steer the front wheel, ensuring the bicycle continues in an essentially straight path. We give the frequency of lean oscillations about the vertical executed during riding. As in the literature, we discuss the neglect of gyroscopic effects, which experiment suggests are negligible.

  15. Global asymptotic stabilisation in probability of nonlinear stochastic systems via passivity

    Science.gov (United States)

    Florchinger, Patrick

    2016-07-01

    The purpose of this paper is to develop a systematic method for global asymptotic stabilisation in probability of nonlinear control stochastic systems with stable in probability unforced dynamics. The method is based on the theory of passivity for nonaffine stochastic differential systems combined with the technique of Lyapunov asymptotic stability in probability for stochastic differential equations. In particular, we prove that a nonlinear stochastic differential system whose unforced dynamics are Lyapunov stable in probability is globally asymptotically stabilisable in probability provided some rank conditions involving the affine part of the system coefficients are satisfied. In this framework, we show that a stabilising smooth state feedback law can be designed explicitly. A dynamic output feedback compensator for a class of nonaffine stochastic systems is constructed as an application of our analysis.

  16. Fixação transpedicular da coluna toraco-lombo-sagrada: análise de 124 parafusos

    Directory of Open Access Journals (Sweden)

    Eunice Carvalho

    2013-01-01

    Full Text Available OBJECTIVO: Avaliar a técnica free hand de colocação de parafusos transpediculares na coluna torácica, lombar e sagrada. MÉTODOS: Avaliação clínica e imagiológica (tomografia computorizada de 25 pacientes (13 mulheres e 12 homens submetidos a instrumentação vertebral num total de 124 parafusos transpediculares aplicados, utilizando a técnica free hand. Os parafusos foram inseridos de T11 a S1, e a maioria destes foram colocados nos níveis L4, L5 e S1. RESULTADOS: 94% dos parafusos transpediculares estavam correctamente colocados no pedículo. Verificou-se que 6% (7 parafusos estavam mal colocados e destes apenas dois violavam a cortical inferomedial, um destes apresentava uma perfuração inferior a 2 mm e o outro entre 2 e 4 mm. Nenhum dos pacientes seguidos apresentou complicações associadas ao incorrecto posicionamento dos parafusos. CONCLUSÃO: A técnica free hand é segura na instrumentação da coluna torácica e lombo-sagrada.

  17. Posterior lumbar interbody fusion using one diagonal fusion cage with transpedicular screw/rod fixation.

    Science.gov (United States)

    Zhao, Jie; Hou, Tiesheng; Wang, Xinwei; Ma, Shengzhong

    2003-04-01

    Posterior lumbar interbody fusion (PLIF) using threaded cages has gained wide popularity for lumbosacral spinal disease. Our biomechanical tests showed that PLIF using a single diagonal cage with unilateral facetectomy does add a little to spinal stability and provides equal or even higher postoperative stability than PLIF using two posterior cages with bilateral facetectomy. Studies also demonstrated that cages placed using a posterior approach did not cause the same increase in spinal stiffness seen with pedicle screw instrumentation, and we concluded that cages should not be used posteriorly without other forms of fixation. On the other hand, placement of two cages using a posterior approach does have the disadvantage of risk to the bilateral nerve roots. We therefore performed a prospective study to determine whether PLIF can be accomplished by utilizing a single diagonal fusion cage with the application of supplemental transpedicular screw/rod instrumentation. Twenty-seven patients underwent a PLIF using one single fusion cage (BAK, Sulzer Spine-Tech, Minneapolis, MN, USA) inserted posterolaterally and oriented anteromedially on the symptomatic side with unilateral facetectomy and at the same level supplemental fixation with a transpedicular screw/rod system. The internal fixation systems included 12 SOCON spinal systems (Aesculap AG, Germany) and 15 TSRH spinal systems (Medtronic Sofamor Danek, USA). The inclusion criteria were grade 1 to 2 lumbar isthmic spondylolisthesis, lumbar degenerative spondylolisthesis, and recurrent lumbar disc herniations with instability. Patients had at least 1 year of low back pain and/or unilateral sciatica and a severely restricted functional ability in individuals aged 28-55 years. Patients with more than grade 2 spondylolisthesis or adjacent-level degeneration were excluded from the study. Patients were clinically assessed prior to surgery by an independent assessor; they were then reassessed at 1, 3, 6, 12, 18, and 24

  18. Self-Stabilising Quadrupedal Running by Mechanical Design

    Directory of Open Access Journals (Sweden)

    Panagiotis Chatzakos

    2009-01-01

    Full Text Available Dynamic stability allows running animals to maintain preferred speed during locomotion over rough terrain. It appears that rapid disturbance rejection is an emergent property of the mechanical system. In running robots, simple motor control seems to be effective in the negotiation of rough terrain when used in concert with a mechanical system that stabilises passively. Spring-like legs are a means for providing self-stabilising characteristics against external perturbations. In this paper, we show that a quadruped robot could be able to perform self-stable running behaviour in significantly broader ranges of forward speed and pitch rate with a suitable mechanical design, which is not limited to choosing legs spring stiffness only. The results presented here are derived by studying the stability of the passive dynamics of a quadruped robot running in the sagittal plane in a dimensionless context and might explain the success of simple, open loop running controllers on existing experimental quadruped robots. These can be summarised in (a the self-stabilised behaviour of a quadruped robot for a particular gait is greatly related to the magnitude of its dimensionless body inertia, (b the values of hip separation, normalised to rest leg length, and leg relative stiffness of a quadruped robot affect the stability of its motion and should be in inverse proportion to its dimensionless body inertia, and (c the self-stable regime of quadruped running robots is enlarged at relatively high forward speeds. We anticipate the proposed guidelines to assist in the design of new, and modifications of existing, quadruped robots. As an example, specific design changes for the Scout II quadruped robot that might improve its performance are proposed.

  19. Partial stability and stabilisation of Boolean networks

    Science.gov (United States)

    Chen, Hong-Wei; Sun, Liang-Jie; Liu, Yang

    2016-07-01

    In this paper, we investigate the stability of Boolean networks and the stabilisation of Boolean control networks with respect to part of the system's states. First, an algebraic expression of the Boolean (control) network is derived by the semi-tensor product of matrices. Then, some necessary and sufficient conditions for partial stability of Boolean networks are given. Finally, the stabilisation of Boolean control networks by a free control sequence and a state-feedback control is investigated and the respective necessary and sufficient conditions are obtained. Examples are provided to illustrate the efficiency of the obtained results.

  20. Late vertebral body fracture after lumbar transpedicular fixation. Report of three cases.

    Science.gov (United States)

    Missori, Paolo; Ramieri, Alessandro; Costanzo, Giuseppe; Peschillo, Simone; Paolini, Sergio; Miscusi, Massimo; D'Andrea, Giancarlo; Delfini, Roberto

    2005-07-01

    Late-onset vertebral body (VB) fracture after lumbar transpedicular fixation has not been previously described in the literature. The authors present three cases in which VB fracture occurred several months after posterolateral fixation in patients with degenerative disease or traumatic injury. The authors suggest that postoperative osteopenia, modified load-sharing function, and intravertebral clefts were responsible for the fractures. Two women and one man were evaluated at a mean follow-up interval of 3 months. Two patients suffered recurrent lumbar pain. Radiography and magnetic resonance imaging revealed fracture of some of the instrumentation-treated VBs. These two patients underwent surgical superior or inferior extension of instrumentation. The third, an asymptomatic patient, received conservative management. The two patients who underwent reoperation made complete recoveries, and there was no evidence of further bone collapse in any case. The authors speculate that alterations in the VBs may occur following application of spinal instrumentation. In rare cases, the device can fracture and consequently lead to recurrent lumbar back pain. Recovery can be achieved by extending the instrumentation in the appropriate direction.

  1. Comparison of two surgeries in treatment of severe kyphotic deformity caused by ankylosing spondylitis: Transpedicular bivertebrae wedge osteotomy versus one-stage interrupted two-level transpedicular wedge osteotomy.

    Science.gov (United States)

    Zhao, Yongfei; Xu, Hui; Zhang, Yonggang; Wang, Zheng; Zhang, Xuesong; Wang, Yan

    2015-12-01

    To explore a simple and effective surgery for correcting severe kyphotic deformity caused by ankylosing spondylitis (AS). From January 2003 to December 2009, we respectively reviewed 32 patients with severe spinal kyphosis caused by AS with at least 2-year follow-up. Patients were divided into two groups, according to surgical methods: transpedicular bivertebrae wedge osteotomy (Group A) or one-stage interrupted two-level transpedicular wedge osteotomy (Group B). We recorded operating time and blood loss. Variation between pre- and post-operative sagittal imbalance, global spinal alignments (Cobb angle of T1 and L5, TLKA), lumbar lordosis, chin-brow vertical angle, thoracolumbar kyphosis angle in both groups were analyzed. The average operating time was 236 ± 39 min and the average blood loss was 2200 ± 712 ml in Group A, and 252 ± 43 min, 2202 ± 737 ml respectively in Group B. There were no significant differences in operating time and blood loss. Variation between pre- and post-operative sagittal imbalance, global spinal alignments, lumbar lordosis and chin-brow vertical angle (CBVA) were comparable between the two groups. The variation of thoracolumbar kyphosis angle was significantly greater in Group B compared with Group A. SRS-22 scores were similar in the two groups at the 2-year follow-up and significantly improved compared with preoperative. For correcting severe kyphosis in patients with AS, the one-stage interrupted two-level transpedicular wedge osteotomy is a safe and effective technique which can significantly improve the thoracolumbar kyphosis angle. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Private sector and stabilisation in Afghanistan

    DEFF Research Database (Denmark)

    Magaard, Tina

    I briefet opsummerer Tina Magaard de vigtigste konklusioner fra konferencen ”Private sector and stabilisation in Afghanistan – a neglected match?”, som blandt andet gav indsigt i udfordringerne og mulighederne for den private sektor i Afghanistan. Ved at kombinere perspektiver fra strategiske...

  3. Catheter-directed percutaneous transpedicular C2/C3 vertebroplasty in a patient with fibrous dysplasia using seldinger technique.

    Science.gov (United States)

    Christoforidis, G; Dang, D; Gabriel, J

    2006-09-01

    A 35-year-old man with polyostotic fibrous dysplasia and a massively enlarged skull presented with Lhermitte sensations due to an unstable, mulitseptated, lytic C2/3 vertebral body complex. Enlarged extracranial vasculature made open surgery a high-risk option and limited percutaneous access. A 5F catheter was directed by using a guidewire into the C2/C3 vertebral body complex via a transpedicularly placed biopsy cannula to ensure polymethylmethacrylate deposition throughout the lytic compartments of the vertebral body complex.

  4. Transpedicular screw fixation in the thoracic and lumbar spine with a novel cannulated polyaxial screw system

    Directory of Open Access Journals (Sweden)

    Lutz Weise

    2008-10-01

    Full Text Available Lutz Weise, Olaf Suess, Thomas Picht, Theodoros KombosNeurochirurgische Klinik, Charité – Universitätsmedizin Berlin, Berlin, GermanyObjective: Transpedicular screws are commonly and successfully used for posterior fixation in spinal instability, but their insertion remains challenging. Even using navigation techniques, there is a misplacement rate of up to 11%. The aim of this study was to assess the accuracy of a novel pedicle screw system.Methods: Thoracic and lumbar fusions were performed on 67 consecutive patients for tumor, trauma, degenerative disease or infection. A total of 326 pedicular screws were placed using a novel wire-guided, cannulated, polyaxial screw system (XIA Precision®, Stryker. The accuracy of placement was assessed post operatively by CT scan, and the patients were followed-up clinically for a mean of 16 months.Results: The total medio-caudal pedicle wall perforation rate was 9.2% (30/326. In 19 of these 30 cases a cortical breakthrough of less than 2 mm occurred. The misplacement rate (defined as a perforation of 2 mm or more was 3.37% (11/326. Three of these 11 screws needed surgical revision due to neurological symptoms or CSF leakage. There have been no screw breakages or dislocations over the follow up-period.Conclusion: We conclude that the use of this cannulated screw system for the placement of pedicle screws in the thoracic and lumbar spine is accurate and safe. The advantages of this technique include easy handling without a time-consuming set up. Considering the incidence of long-term screw breakage, further investigation with a longer follow-up period is necessary.Keywords: spinal instrumentation, pedicle screws, misplacement, pedicle wall perforation

  5. Comparison of the safety of three methods of lumbar transpedicular screw fixation

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective: To choose a proper method of lumbar transpedicular screw fixation at different lumbar levels among the three methods ( Roy-Camille's method, Magerl's method and Du's method) in the Chinese population.Methods: Three-dimensional ( 3-D ) images were reconstructed with image data of 42 adult lumbar segments that were scanned by Electron Beam CT. The three methods of lumbar pedicle screw fixation were simulated on the 3-D reconstructed images and the parameters of implanting pedicle screws were measured.Results: There was statistically significant difference at the distance from the entrance point to the pedicle axis between the three methods (P < 0. 001). The distances measured by Du's method were shortest from L1 to L4,and the distances measured by Magerl's method were shortest at L5 (P < 0.05). There was no significant difference from L1 to L2 (P > 0.05) but significant difference from L3 to L5 at inserting safe ranges of TSA (transverse section angle) was found between the three methods (P <0.05). From L3 to L4, the inserting safe ranges of TSA measured by Du's and Magerl's methods were significantly larger than that measured by Roy-Camille's method (P <0.05), but there was no significant difference between them (P > 0.05). At L5, the inserting safe ranges of TSA measured by Magerl's method were largest among the three methods (P < 0.05).Conclusions: Among the three methods, Du's method is the best choice from L1 to LA because its distance from the entrance point to the pedicle axis is shortest and the safe range of TSA is largest; Magerl's method can be used from L3 to L5 and is the best choice at L5; Roy-Camille's method is applicable at L1 and L2.

  6. New directions in stabilisation policies

    Directory of Open Access Journals (Sweden)

    Ralf Fendel

    2004-12-01

    Full Text Available Recently, a new class of macroeconomic business cycle models has emerged. Stochastic dynamic general equilibrium models with rational expectations originally employed by RBC researchers are combined with nominal rigidities and imperfect competition traditionally highlighted by New Keynesian economists. This class of models leads to a new paradigm in business cycle theory and stabilization policies. The paper presents the main characteristics and implications of the new class of models in a predominantly non-technical way. In order to highlight the progress connected with the new class of models, it puts them into the context of former debates on stabilization policy, such as the Phillips curve dispute.

  7. Comparative Assessment of Stabilised Polybutadiene Binder under Accelerated Ageing

    Directory of Open Access Journals (Sweden)

    Luiz Felipe Cannaval Sbegue

    2016-04-01

    Full Text Available Polybutadiene elastomers are versatile materials, being employed at several applications from rocket propellant binder to adhesives and sealants. The elastomers derived from hydroxyl-terminated polybutadiene are usually stabilised with antioxidants to prevent degradation. In this study, a comparative assessment among 2,2’-methylene-bis (4-methyl-6-tert-butylphenol (AO2246, 2,6-di-tert-butyl-4-methylphenol (BHT, p-phenylenediamine (pPDA, and triphenylphosphine (TPP regarding stabilisation of hydroxyl-terminated polybutadiene binder under accelerated ageing (six months at 65 °C was carried out. Evaluation of antioxidants effectiveness was examined through Oxidation Induction time, sol/gel extraction, swelling and mechanical testing, dynamic mechanical analysis, and mass variation measurement. AO2246 yielded the best performance, meanwhile BHT was poorly protective. TPP acted as prooxidant, causing a severe degradation of the binder, and pPDA was not manageable to be assessed due to the lower curing degree of the resulted polyurethane.

  8. A priori calculations for the rotational stabilisation

    Directory of Open Access Journals (Sweden)

    Iwata Yoritaka

    2013-12-01

    Full Text Available The synthesis of chemical elements are mostly realised by low-energy heavy-ion reactions. Synthesis of exotic and heavy nuclei as well as that of superheavy nuclei is essential not only to find out the origin and the limit of the chemical elements but also to clarify the historical/chemical evolution of our universe. Despite the life time of exotic nuclei is not so long, those indispensable roles in chemical evolution has been pointed out. Here we are interested in examining the rotational stabilisation. In this paper a priori calculation (before microscopic density functional calculations is carried out for the rotational stabilisation effect in which the balance between the nuclear force, the Coulomb force and the centrifugal force is taken into account.

  9. Stabilising the Planck mass shortly after inflation

    CERN Document Server

    van de Bruck, Carsten; Robinson, Mathew

    2015-01-01

    We consider a model of the early universe which consists of two scalar fields: the inflaton, and a second field which drives the stabilisation of the Planck mass (or gravitational constant). We show that the non-minimal coupling of this second field to the Ricci scalar sources a non-adiabatic pressure perturbation. By performing a fully numerical calculation we find, in turn, that this boosts the amplitude of the primordial power spectrum after inflation.

  10. Local string models and moduli stabilisation

    Science.gov (United States)

    Quevedo, Fernando

    2015-03-01

    A brief overview is presented of the progress made during the past few years on the general structure of local models of particle physics from string theory including: moduli stabilisation, supersymmetry breaking, global embedding in compact Calabi-Yau compactifications and potential cosmological implications. Type IIB D-brane constructions and the Large Volume Scenario (LVS) are discussed in some detail emphasising the recent achievements and the main open questions.

  11. Effects of electron beam irradiation on the property behaviour of poly(ether-block-amide) blended with various stabilisers

    Science.gov (United States)

    Murray, Kieran A.; Kennedy, James E.; Barron, Valerie; McEvoy, Brian; Vrain, Olivier; Ryan, Damien; Cowman, Richard; Higginbotham, Clement L.

    2015-05-01

    Radiosterilisation can induce modifications and/or degradation to transpire in poly(ether-block-amide) (PEBA) following irradiation. The current investigation utilises combined synergistic mixtures of stabilisers to minimise these effects, by melt blending them with the PEBA material. Hindered amine stabilisers (HAS), primary antioxidants and secondary antioxidants were the stabilisers incorporate to reduce/eliminate the effects of 50 kGy electron beam irradiation dose on the material. Results were discussed by comparing the stabilising efficiency of mixtures on the PEBA material in contrast to the control sample. Dynamic frequency sweeps demonstrated the formation of crosslinks, where the degree of crosslinking was dependent on the combination of stabilisers mixed in the base material (PEBA). The storage modulus displayed that PEBA blended with Irganox 565 had very slight changes in contrast to all other samples following irradiation. However, since this sample is a phenol containing system, severe discolouration was observed in comparison to other samples due to the oxidation of the hindered phenol. Overall, this study provides compelling evidence that a combined synergistic mixture of Irganox 565 (multifunctional phenolic antioxidant) and Tinuvin 783 (hindered amide light stabiliser) with PEBA, resulted in the best radiation stability.

  12. Pulsed laser excitation of phosphate stabilised silver nanoparticles

    Indian Academy of Sciences (India)

    Jyotirmayee Mohanty; Dipak K Palit; Laxminarayan V Shastri; Avinash V Sapre

    2000-02-01

    Laser flash photolysis studies were carried out on two types of silver nanoparticles prepared by -radiolysis of Ag+ solutions in the presence of polyphosphate as the stabiliser. Type I silver nanoparticles displayed a surface plasmon band at 390 nm. Type II silver nanoparticles showed a 390 nm surface plasmon band with a shoulder at 550 nm. On photoexcitation in the surface plasmon band region, using 35 picosecond laser pulses at 355 nm and 532 nm, the type II solutions showed transient bleaching and absorption signals in the 450-900 nm region, which did not decay appreciably up to 5 nanoseconds. These transient changes were found to get annealed in the interval where 5 ns < < 100 ns. Extended photolysis of the nanoparticle solutions with repetitive laser pulses resulted in a decrease in the values of the average particle size which were measured by employing the dynamic light scattering technique.

  13. Surgical correction of spinal deformity with the use of transpedicular screw spinal systems in children with idiopathic thoracic scoliosis

    Directory of Open Access Journals (Sweden)

    Nurbek N Nadirov

    2016-06-01

    Full Text Available Aim. To compare the results of surgical correction of spinal deformity in children with idiopathic thoracic scoliosis with the use of transpedicular screw spinal systems with different pedicle screw placement. Material and methods. Thirty-one patients (14–17 years with spinal curvature with a Cobb angle from 40° to 79° were operated on. Surgical correction of the deformity was performed using two methods, depending on the possible placement of a pedicle screw. The first group included 16 patients for whom the transpedicular support elements were placed on both sides, throughout the completely deformed spine. The second group included 15 patients for whom the pedicle screws were not placed for two or more vertebrae on the concave side of the curve, at the top of the main curve. Results. The mean percent correction of the spinal deformity for the first and second groups was 92.5% and 82.6%, respectively. The mean percentage of derotation of the apical vertebra for the first and second groups was 73.9% and 23%, respectively. Conclusion. The use of data based on the anatomical and anthropometric features of the vertebral body with scoliosis facilitates selection of the best option for correction of thoracic curve in children with idiopathic scoliosis using pedicle multi-support metal construction. The use of the spinal pedicle system for correction of spinal deformity in children with idiopathic scoliosis enabled a uniform load distribution along the support elements of the metal construction and maintained the correction in the late postoperative follow-up period.

  14. Stabilisation de la formule des traces tordue

    CERN Document Server

    Moeglin, Colette

    2016-01-01

    Ce travail en deux volumes donne la preuve de la stabilisation de la formule des trace tordue. Stabiliser la formule des traces tordue est la méthode la plus puissante connue actuellement pour comprendre l'action naturelle du groupe des points adéliques d'un groupe réductif, tordue par un automorphisme, sur les formes automorphes de carré intégrable de ce groupe. Cette compréhension se fait en réduisant le problème, suivant les idées de Langlands, à des groupes plus petits munis d'un certain nombre de données auxiliaires; c'est ce que l'on appelle les données endoscopiques. L'analogue non tordu a été résolu par J. Arthur et dans ce livre on suit la stratégie de celui-ci. Publier ce travail sous forme de livre permet de le rendre le plus complet possible. Les auteurs ont repris la théorie de l'endoscopie tordue développée par R. Kottwitz et D. Shelstad et par J.-P. Labesse. Ils donnent tous les arguments des démonstrations même si nombre d'entre eux se trouvent déjà dans les travaux d'Ar...

  15. SAPHYR: A new chemical stabilisation process

    Energy Technology Data Exchange (ETDEWEB)

    Baratto, Gilles; Fernandes, Paulo; Patria; Lucie; Cretenot, Didier

    2003-07-01

    Odour control and dewaterability are the key criteria during biosolids storage either for use on land or incineration. In the case of use on land, stabilisation/sanitisation are also part of the key criteria. Vivendi Water Systems developed the SAPHYR process to answer those three requirements. The SAPHYR process principle is based on an acidification of biosolids associated to the addition of nitrite. The main results are a noticeable odour control lasting other periods of 6 to 9 months, an improved dewaterability (2 to 4 points of dryness) and depending on chemical dosages a stabilisation or a sanitisation of biosolids. Another characteristic is that biosolids conditioned with the Saphyr process can be used both on land or for incineration. After several demonstrations on more than 5 different plants throughout France on a 10 000 p.e. unit, the first industrial reference of the process was installed on a 50 000 population equivalent wastewater treatment plant in 2002 and has been in operation since december 2002. A close monitoring of the process operation, the biosolids quality and its storage and spreading on land is planned from November 2002 to spring 2003. A comparison with lime addition will take place on the same plant. The present paper will produce a presentation of the SAPHYR process, its operation on a 50 000 pe WWTP and its different applications for biosolids storage.

  16. ON THE HIDDEN REVENUE EFFECTS OF WOOL PRICE STABILISATION IN AUSTRALIA: INITIAL RESULTS

    OpenAIRE

    1980-01-01

    A preliminary analysis of demand in eight major OECD wool-consuming countries is used to provide up-to-date estimates of price elasticities of demand for wool. Those elasticities are employed to calculate ex ante market prices, assuming no wool price stabilisation in Australia. The computed ex ante prices are used in a dynamic simulation to estimate demand and, hence, revenue from wool sales to the eight countries in the absence of reserve price operations in Australia. Based on the preferred...

  17. The stabilisation of final focus system

    Indian Academy of Sciences (India)

    P A Coe; D Urner; A Reichold

    2007-12-01

    The StaFF (stabilisation of final focus) system will use interferometers to monitor the relative positions and orientations of several key components in the beam-delivery and interaction region. Monitoring the relative positions of the ILC final focus quadrupole magnets will be the most demanding application, where mutual and beam-relative stability will have a direct impact on machine luminosity. Established, laser-based frequency scanning interferometry (FSI) and fixed-frequency interferometry (FFI) offer positional resolution at length scales of the laser wavelength (1500 nm to 1560 nm) and a thousandth of the wavelength, respectively. As part of the ATF at KEK, StaFF will use interferometers to measure lines of a geodetic network to record relative motion between two beam position monitors. Interferometers are being designed and tested in Oxford prior to deployment at the ATF.

  18. Aqueous foams stabilised solely by nanoparticles

    Science.gov (United States)

    Langevin, Dominique

    2011-03-01

    Particles are being increasingly used to stabilise foams and emulsions, the corresponding emulsions being known as ``Pickering'' emulsions. One of the peculiarities of these systems is the absence of Ostwald ripening: since the bubbles or drops do not grow (coalescence seems also suppressed) both foams and emulsions are stable over extremely long periods of time (months). These features make particles very interesting surface active agents as compared to standard surfactants or polymers/proteins. The origin of the suppression of ripening can be traced to the unusual behaviour of the interfacial layers made by these particles. The layers are solid-like and the usual characterisation methods (surface tension, surface rheology) are not straightforward to use. In this presentation, we will illustrate these difficulties with experiments made with partially hydrophobic silica nanoparticles. We will also discuss the relevance of foam characterisations methods such as multiple light scattering and X-ray tomography.

  19. Advances in cervical anterior transpedicular screw fixation technique%颈椎前路椎弓根螺钉内固定技术的研究进展

    Institute of Scientific and Technical Information of China (English)

    欧阳钧; 吴卫东

    2013-01-01

    Cervical posterior transpedicular screw technique was first introduced to clinic in 1994. Due to its good biomechanical stability and satisfactory fusion effect,it has become a major solution to some cervical spine diseases.However,most of the diseases involved in vertebral body and posterior transpedicular screw technique is complex and difficult,these factors prevent the technique be widely used in cervical spine surgery.In 2008,a new concept of cervical anterior transpedicular screw fixation technique was first proposed.This new technique inherited advantages of posterior transpedicular screw fixation,and of course,it also overcomes drawbacks of conventional anterior vertebral body screw fixa-tion.This review presents an overview of anterior transpedicular screw fixation technique on anatomical and biomechanical field.%颈椎后路椎弓根螺钉固定技术于1994年首次应用于临床,鉴于其稳定的固定融合效果,已成为多种颈椎疾病的主要治疗手段。然而,由于颈椎病灶的好发部位多位于前部,且颈椎后路椎弓根螺钉操作难度较大,在一定程度上限制了该技术的发展。2008年颈椎前路椎弓根螺钉固定技术的概念被首次提出,此技术继承了后路椎弓根螺钉生物力学性能卓越的优点,且克服传统颈椎前路椎体螺钉稳定性较差的缺点。本文主要就颈椎前路椎弓根螺钉固定技术的解剖学及生物力学研究进展进行综述。

  20. Thermo stabilisation of poly (butylene adipate-co-terephthalate

    Directory of Open Access Journals (Sweden)

    Rodrigo Paulino Chaves

    Full Text Available Abstract Poly (butylene adipate-co-terephthalate - PBAT is a synthetic biodegradable polymer commonly used for plastic film production from neat polymer or nanocomposites. The PBAT is submitted to high temperatures and shear rate during its processing. In the present study, the thermo stabilisation of PBAT by the addition of two types of stabilisers was studied using a torque rheometer at 60 rpm and two levels of temperature. The stabilisers were used as master batches with a percentage of 10% by weight of additive in the PBAT. Molecular weight, torque values after 10 minutes of mixing, and absorbance at 400 nm were used to evaluate the process of stabilisation. The primary and secondary antioxidant used here had a positive effect on both processing temperatures, 180 and 200 °C. The best results indicate that the primary antioxidant could be used alone to protect PBAT against thermodegradation reactions.

  1. CLAY SOIL STABILISATION USING POWDERED GLASS

    Directory of Open Access Journals (Sweden)

    J. OLUFOWOBI

    2014-10-01

    Full Text Available This paper assesses the stabilizing effect of powdered glass on clay soil. Broken waste glass was collected and ground into powder form suitable for addition to the clay soil in varying proportions namely 1%, 2%, 5%, 10% and 15% along with 15% cement (base by weight of the soil sample throughout. Consequently, the moisture content, specific gravity, particle size distribution and Atterberg limits tests were carried out to classify the soil using the ASSHTO classification system. Based on the results, the soil sample obtained corresponded to Group A-6 soils identified as ‘fair to poor’ soil type in terms of use as drainage and subgrade material. This justified stabilisation of the soil. Thereafter, compaction, California bearing ratio (CBR and direct shear tests were carried out on the soil with and without the addition of the powdered glass. The results showed improvement in the maximum dry density values on addition of the powdered glass and with corresponding gradual increase up to 5% glass powder content after which it started to decrease at 10% and 15% powdered glass content. The highest CBR values of 14.90% and 112.91% were obtained at 5% glass powder content and 5mm penetration for both the unsoaked and soaked treated samples respectively. The maximum cohesion and angle of internal friction values of 17.0 and 15.0 respectively were obtained at 10% glass powder content.

  2. Antipsychotics, mood stabilisers, and risk of violent crime

    OpenAIRE

    Fazel, Seena; Zetterqvist, Johan; Larsson, Henrik; Långström, Niklas; Lichtenstein, Paul

    2014-01-01

    Summary Background Antipsychotics and mood stabilisers are prescribed widely to patients with psychiatric disorders worldwide. Despite clear evidence for their efficacy in relapse prevention and symptom relief, their effect on some adverse outcomes, including the perpetration of violent crime, is unclear. We aimed to establish the effect of antipsychotics and mood stabilisers on the rate of violent crime committed by patients with psychiatric disorders in Sweden. Methods We used linked Swedis...

  3. Wind power stabilising control. Demonstration on the Nordic grid

    Energy Technology Data Exchange (ETDEWEB)

    Elkington, Katherine

    2012-07-01

    When unconventional types of generators such as doubly fed induction generators (DFIGs) are used in a power system, the system behaves differently under abnormal dynamic events. For example, DFIGs cause different modes of oscillation in the power system, and respond differently to changes in voltage. In order to damp oscillations in the system, it is necessary to understand the equipment causing these oscillations, and the methods of optimally damping the oscillations. Large power oscillations can occur in a power system as a result of disturbances. Ordinarily these oscillations are slow and, in principle, it is possible to damp them with the help of wind power. This suggests the use of a power oscillation damping (POD) controller for a DFIG, similar to a power system stabiliser (PSS) for a synchronous generator. Voltage stability is another important aspect of the safe operation of a power system. It has been shown that the voltage stability of a power system is affected by induction generators and also DFIGs, and we investigate some aspects of this here. In this study we develop control strategies for large wind farms comprising DFIGs, and study the impact of the wind farms on a system which is designed to reflect the dynamics of the Nordic power system. The design of multiple PODs in a wind farm is undertaken using linear matrix inequalities (LMIs). The impact of the wind turbines is investigated through the use of linear and dynamic simulations. It has been demonstrated that DFIG-based wind farms can be used for damping oscillations, even when they are not producing their rated power, and that they can also improve the critical clearing time of some faults. However, they may have an adverse impact on power systems after large voltage disturbances

  4. Soil Stabilisation Using Ground Granulated Blast Furnace Slag

    Directory of Open Access Journals (Sweden)

    Ashish Kumar Pathak

    2014-05-01

    Full Text Available Stabilisation is a broad sense for the various methods employed and modifying the properties of a soil to improve its engineering performance and used for a variety of engineering works. In today‟s day soil stabilisation is the major problem for civil engineers, either for construction of road and also for increasing the strength or stability of soil and reduces the construction cost. In this thesis the soil are stabilised by ground granulated blast furnace slag (GGBS and this material is obtained from the blast furnace of cement plant, which is the byproduct of iron (from ACC plant, sindri. It is generally obtained in three shaped one is air cooled, foamed shaped and another is in granulated shaped. The use of by-product materials for stabilisation has environmental and economic benefits. Ground granulated blast furnace slag (GGBS material is used in the current work to stabilise soil (clay. The main objectives of this research were to investigate the effect of GGBS on the engineering property (optimum moisture content and maximum dry density, plastic limit, liquid limit, compaction, unconfined compressive strength, triaxial and California bearing ratio test of the soil and determine the engineering properties of the stabilised.

  5. Pavement thickness and stabilised foundation layer assessment using ground-coupled GPR

    Science.gov (United States)

    Hu, Jinhui; Vennapusa, Pavana K. R.; White, David J.; Beresnev, Igor

    2016-07-01

    Experimental results from field and laboratory investigations using a ground-coupled ground penetrating radar (GPR), dielectric measurement, magnetic imaging tomography (MIT) and dynamic cone penetrometer (DCP) tests are presented. Dielectric properties of asphalt pavement and stabilised and unstabilised pavement foundation materials were evaluated in the laboratory in frozen and unfrozen conditions. Laboratory test results showed that dielectric properties of materials back-calculated from GPR in comparison to dielectric gauge measurements are strongly correlated and repeatable. For chemically stabilised materials, curing time affected the dielectric properties of the materials. Field tests were conducted on asphalt pavement test sections with different foundation materials (stabilised and unstabilised layers), drainage conditions and layer thicknesses. GPR and MIT results were used to determine asphalt layer thicknesses and were compared with measured core thicknesses, while GPR and DCP were used to assess foundation layer profiles. Asphalt thicknesses estimated from GPR showed an average error of about 11% using the dielectric gauge values as input. The average error reduced to about 4% when calibrated with cores thicknesses. MIT results showed thicknesses that are about 9% higher than estimated using GPR. Foundation layer thicknesses could not be measured using GPR due to variations in moisture conditions between the test sections, which is partly attributed to variations in gradation and drainage characteristics of the subbase layer.

  6. Computed tomography-based morphometric analysis of cervical pedicles in Indian population: A pilot study to assess feasibility of transpedicular screw fixation

    Directory of Open Access Journals (Sweden)

    A R Patwardhan

    2012-01-01

    Full Text Available Background: Cervical transpedicular screw fixation is safe and is probably going to be the gold standard for cervical spine fixation. However, cervical transpedicular screw use in the Asian population can be limited as the transverse diameter in this group of patients may not be adequate to accommodate the 3.5-mm pedicular screw thus injuring the vital structures located in the close proximity of the pedicles. Thus lateral mass fixation remains the mainstay of treatment. The present study evaluated the transverse cervical pedicle diameter of C2-C7 vertebrae in a pilot study in 27 Indian subjects using computed tomography (CT imaging and evaluated the feasibility of transpedicular screw fixation in them. Aims: To evaluate the feasibility of transpedicular screw fixation in the Indian population. Settings and Design: The cervical pedicle diameter size differs between the Asian and non-Asian population. The authors studied the transverse pedicle diameter of the C2-C7 of the cervical spine in the Indian population using CT measurements. This cross-sectional study was carried out at a tertiary care centre for a period of four months from October 2010 to December 2010. Material and Methods: Measurements of cervical pedicles in the subjects were performed on the CT workstation from the CT images taken at 2.5-mm interval. The transverse pedicle diameter was defined as the outermost diameter of the pedicle, taken perpendicular to the axis of the pedicle at the narrowest point and measured in millimeters±0.1 mm. Statistical Analysis: Descriptive statistics was used to represent percentage of transverse diameter of cervical pedicles less than 5 mm in male and female subjects at C2-C7 levels. Since there is no previous study done in India, we initiated the study with sample size of 27 as a pilot study. The statistical analysis was performed using SPSS software. Results: The mean transverse diameters of the cervical pedicles of C2, C3, C4, C5, C6 and C7 in

  7. Moduli stabilisation for chiral global models

    Energy Technology Data Exchange (ETDEWEB)

    Cicoli, Michele [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Abdus Salam International Centre for Theoretical Physics, Trieste (Italy); Mayrhofer, Christoph [Heidelberg Univ. (Germany). Inst. fuer Theoretische Physik; Valandro, Roberto [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2011-10-15

    We combine moduli stabilisation and (chiral) model building in a fully consistent global set-up in Type IIB/F-theory. We consider compactifications on Calabi-Yau orientifolds which admit an explicit description in terms of toric geometry. We build globally consistent compactifications with tadpole and Freed-Witten anomaly cancellation by choosing appropriate brane set-ups and world-volume fluxes which also give rise to SU(5)- or MSSM-like chiral models. We fix all the Kaehler moduli within the Kaehler cone and the regime of validity of the 4D effective field theory. This is achieved in a way compatible with the local presence of chirality. The hidden sector generating the non-perturbative effects is placed on a del Pezzo divisor that does not have any chiral intersections with any other brane. In general, the vanishing D-term condition implies the shrinking of the rigid divisor supporting the visible sector. However, we avoid this problem by generating r

  8. Moduli stabilisation for chiral global models

    Energy Technology Data Exchange (ETDEWEB)

    Cicoli, Michele [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Abdus Salam International Centre for Theoretical Physics, Trieste (Italy); Mayrhofer, Christoph [Heidelberg Univ. (Germany). Inst. fuer Theoretische Physik; Valandro, Roberto [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2011-10-15

    We combine moduli stabilisation and (chiral) model building in a fully consistent global set-up in Type IIB/F-theory. We consider compactifications on Calabi-Yau orientifolds which admit an explicit description in terms of toric geometry. We build globally consistent compactifications with tadpole and Freed-Witten anomaly cancellation by choosing appropriate brane set-ups and world-volume fluxes which also give rise to SU(5)- or MSSM-like chiral models. We fix all the Kaehler moduli within the Kaehler cone and the regime of validity of the 4D effective field theory. This is achieved in a way compatible with the local presence of chirality. The hidden sector generating the non-perturbative effects is placed on a del Pezzo divisor that does not have any chiral intersections with any other brane. In general, the vanishing D-term condition implies the shrinking of the rigid divisor supporting the visible sector. However, we avoid this problem by generating r

  9. Southwick Osteotomy Stabilised with External Fixator

    Science.gov (United States)

    Grubor, Predrag; Mitkovic, Milorad; Grubor, Milan

    2014-01-01

    ABSTRACT Introduction: Epiphysiolysis of the femoral head is the most common accident occurring towards the end of pre-puberty and puberty growth. Case report: The author describes the experience in the treatment of chronic epiphysiolysis in two patients treated by Southwick osteotomy. The site is accessed by way of a 15-cm long lateral skin incision and the trochanteric region is reached through the layers. The osteotomy angles prepared beforehand on a thin aluminium model are used to mark the Southwick osteotomy site on the anterior and lateral sides at the level of the lesser trochanter. Before performing the trochanteric osteotomy, two Mitković convergent pins type M20 are applied distally and proximally, above the planned osteotomy site. A tenotomy of the iliopsas muscle is performed, and then the previously marked bone triangle is redissected up to three quarters of the width of the femur. The distal part of the femur is rotated inwards, so that the patella is turned towards the ceiling. The osteotomised fragments of the femur are adapted, repositioned and fixated by installing an external fixator on the previously placed pins. Two more pins are placed, one proximally and one distally, with a view to adequately stabilising the femur. The patient was mobile from day two after the surgery. If, after the surgery, the lead surgeon realises that there is a requirement to make a correction of 5, 10 and 15 degrees of the valgus, varus, anteversion or retroversion deformity, the correction shall be performed without surgically opening the patient, using the fixator pins. Conclusion: After performing a Southwick osteotomy it is easier to adapt, reposition and fixate the osteotomised fragments of the femur using a fixator type M20. Adequate stability allows regaining mobility quickly, which in turn is the best prevention of chondrolysis of the hip. It is possible to make post-operative valgus, varus, anteversion and retroversion corrections of 5, 10 and 15 degrees

  10. Stabilisation of a class of 2-DOF underactuated mechanical systems via direct Lyapunov approach

    Science.gov (United States)

    Turker, Turker; Gorgun, Haluk; Cansever, Galip

    2013-06-01

    This paper represents an alternative stabilisation procedure for a class of two degree-of-freedom underactuated mechanical systems based on a set of transformations and a Lyapunov function. After simplifying dynamic equations of the system via partial feedback linearisation and coordinate changes, the stability of the system is provided with Lyapunov's direct method. Proposed control scheme is used on two different examples and asymptotic convergence for each system is proven by means of La Salle's invariance principle. The designed controller is successfully illustrated through numerical simulations for each example.

  11. War, Peace and Stabilisation: Critically Reconceptualising Stability in Southern Afghanistan

    Directory of Open Access Journals (Sweden)

    William Robert Carter

    2013-06-01

    Full Text Available This article critically treats stabilisation theory and programming through a perspective of peace and conflict, and argues for stabilisation’s reconceptualisation. Through tracking the concept’s emergence, it outlines that stabilisation is theoretically rooted in an insecurity-underdevelopment problematic and relies on the Liberal Peace thesis as a solution. When this concept was operationalised in southern Afghanistan, however, it was translated into a praxis informed by state-building and counterinsurgency imperatives. This approach ultimately produced confused, sometimes counterproductive, effects: simultaneously engendering a liberal, negative, rented and victor’s peace. The article concludes by arguing that stabilisation should be reconceptualised so that it pursues a positive and hybrid peace if it is to be a more effective source of guidance for policy and practice. The first step is to denaturalise the ‘formal’ state in conflict and fragile environments as being seen as a panacea to all ills of instability.

  12. Bounded stabilisation of stochastic port-Hamiltonian systems

    Science.gov (United States)

    Satoh, Satoshi; Saeki, Masami

    2014-08-01

    This paper proposes a stochastic bounded stabilisation method for a class of stochastic port-Hamiltonian systems. Both full-actuated and underactuated mechanical systems in the presence of noise are considered in this class. The proposed method gives conditions for the controller gain and design parameters under which the state remains bounded in probability. The bounded region and achieving probability are both assignable, and a stochastic Lyapunov function is explicitly provided based on a Hamiltonian structure. Although many conventional stabilisation methods assume that the noise vanishes at the origin, the proposed method is applicable to systems under persistent disturbances.

  13. Stabilisation of atlantoaxial subluxation in the dog through ventral arthrodesis.

    Science.gov (United States)

    Jeserevics, J; Srenk, P; Beranekl, J; Jaggy, A; Touru, S; Cizinauskas, S

    2008-02-01

    Ten miniature breed dogs with atlantoaxial subluxation underwent ventral lag screw stabilisation. The procedure did not include bone graft packing into the atlantoaxial articulation. Four dogs showed continuous improvement after surgery. Three dogs developed complications due to external trauma and postoperative implant failure but improved with conservative therapy. Three patients died or were euthanized in early perioperative or postoperative period. The long-term outcome was good or favourable in all surviving patients. Suspected fibrous tissue proliferation and stabilisation without permanent bone fusion was found to be clinically satisfactory when the atlantoaxial joint has been subjected to limited stress during a long-term monitoring period.

  14. Embolization by Direct Puncture with a Transpedicular Approach Using an Isocenter Puncture (ISOP) Method in a Patient with a Type II Endoleak After Endovascular Aortic Repair (EVAR)

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, Yukihisa, E-mail: yukky.oct.22@gmail.com; Hamaguchi, Shingo [St. Marianna University, School of Medicine, Department of Radiology (Japan); Nishimaki, Hiroshi [St. Marianna University, School of Medicine, Department of Cardiovascular Surgery (Japan); Kon, Yuri [St. Marianna University, School of Medicine, Department of Radiology (Japan); Chiba, Kiyoshi; Sakurai, Yuka [St. Marianna University, School of Medicine, Department of Cardiovascular Surgery (Japan); Murakami, Kenji; Arai, Yasunori [St. Marianna University, School of Medicine, Department of Radiology (Japan); Miyairi, Takeshi [St. Marianna University, School of Medicine, Department of Cardiovascular Surgery (Japan); Nakajima, Yasuo [St. Marianna University, School of Medicine, Department of Radiology (Japan)

    2015-06-15

    BackgroundEndovascular aortic repair (EVAR) requires further intervention in 20-30 % of cases, often due to type II endoleak (T2EL). Management options for T2EL include transarterial embolization, direct puncture (DP), or transcaval embolization. We report the case of an 80-year-old man with T2EL who successfully underwent DP embolization.MethodsEmbolization by DP was performed with a transpedicular approach using an isocenter puncture (ISOP) method. An isocenter marker (ICM) was placed at a site corresponding to the aneurysm sac on fluoroscopy in two directions (frontal and lateral views). A vertebroplasty needle was inserted tangentially to the ICM under fluoroscopy and advanced to the anterior wall of the vertebral body. A 20 cm-length, 20-G-PTCD needle was inserted through the outer needle of the 13-G needle and advanced to the ICM. Sac embolization using 25 % N-buty-2-cyanoacrylate diluted with Lipiodol was performed. After complete embolization, rotational DA confirmed good filling of the sac with Lipiodol. The outer cannula and 13-G needle were removed and the procedure was completed.ResultsThe patient was discharged the next day. Contrast-enhanced computed tomography 1 and 8 months later showed no Lipiodol washout in the aneurysm sac, no endoleak recurrence, and no expansion of the excluded aneurysm.ConclusionDP with a transpedicular approach using ISOP may be useful when translumbar and transabdominal approaches prove difficult.

  15. Improving the trajectory of transpedicular transdiscal lumbar screw fixation with a computer-assisted 3D-printed custom drill guide

    Directory of Open Access Journals (Sweden)

    Zhen-Xuan Shao

    2017-07-01

    Full Text Available Transpedicular transdiscal screw fixation is an alternative technique used in lumbar spine fixation; however, it requires an accurate screw trajectory. The aim of this study is to design a novel 3D-printed custom drill guide and investigate its accuracy to guide the trajectory of transpedicular transdiscal (TPTD lumbar screw fixation. Dicom images of thirty lumbar functional segment units (FSU, two segments of L1–L4 were acquired from the PACS system in our hospital (patients who underwent a CT scan for other abdomen diseases and had normal spine anatomy and imported into reverse design software for three-dimensional reconstructions. Images were used to print the 3D lumbar models and were imported into CAD software to design an optimal TPTD screw trajectory and a matched custom drill guide. After both the 3D printed FSU models and 3D-printed custom drill guide were prepared, the TPTD screws will be guided with a 3D-printed custom drill guide and introduced into the 3D printed FSU models. No significant statistical difference in screw trajectory angles was observed between the digital model and the 3D-printed model (P > 0.05. Our present study found that, with the help of CAD software, it is feasible to design a TPTD screw custom drill guide that could guide the accurate TPTD screw trajectory on 3D-printed lumbar models.

  16. The active disturbance rejection control approach to stabilisation of coupled heat and ODE system subject to boundary control matched disturbance

    Science.gov (United States)

    Guo, Bao-Zhu; Liu, Jun-Jun; AL-Fhaid, A. S.; Younas, Arshad Mahmood M.; Asiri, Asim

    2015-08-01

    We consider stabilisation for a linear ordinary differential equation system with input dynamics governed by a heat equation, subject to boundary control matched disturbance. The active disturbance rejection control approach is applied to estimate, in real time, the disturbance with both constant high gain and time-varying high gain. The disturbance is cancelled in the feedback loop. The closed-loop systems with constant high gain and time-varying high gain are shown, respectively, to be practically stable and asymptotically stable.

  17. Lumbar Spinal Stenosis Minimally Invasive Treatment with Bilateral Transpedicular Facet Augmentation System

    Energy Technology Data Exchange (ETDEWEB)

    Masala, Salvatore, E-mail: salva.masala@tiscali.it [Interventional Radiology and Radiotherapy, University of Rome ' Tor Vergata' , Department of Diagnostic and Molecular Imaging (Italy); Tarantino, Umberto [University of Rome ' Tor Vergata' , Department of Orthopaedics and Traumatology (Italy); Nano, Giovanni, E-mail: gionano@gmail.com [Interventional Radiology and Radiotherapy, University of Rome ' Tor Vergata' , Department of Diagnostic and Molecular Imaging (Italy); Iundusi, Riccardo [University of Rome ' Tor Vergata' , Department of Orthopaedics and Traumatology (Italy); Fiori, Roberto, E-mail: fiori.r@libero.it; Da Ros, Valerio, E-mail: valeriodaros@hotmail.com; Simonetti, Giovanni [Interventional Radiology and Radiotherapy, University of Rome ' Tor Vergata' , Department of Diagnostic and Molecular Imaging (Italy)

    2013-06-15

    Purpose. The purpose of this study was to evaluate the effectiveness of a new pedicle screw-based posterior dynamic stabilization device PDS Percudyn System Trade-Mark-Sign Anchor and Stabilizer (Interventional Spine Inc., Irvine, CA) as alternative minimally invasive treatment for patients with lumbar spine stenosis. Methods. Twenty-four consecutive patients (8 women, 16 men; mean age 61.8 yr) with lumbar spinal stenosis underwent implantation of the minimally invasive pedicle screw-based device for posterior dynamic stabilization. Inclusion criteria were lumbar stenosis without signs of instability, resistant to conservative treatment, and eligible to traditional surgical posterior decompression. Results. Twenty patients (83 %) progressively improved during the 1-year follow-up. Four (17 %) patients did not show any improvement and opted for surgical posterior decompression. For both responder and nonresponder patients, no device-related complications were reported. Conclusions. Minimally invasive PDS Percudyn System Trade-Mark-Sign has effectively improved the clinical setting of 83 % of highly selected patients treated, delaying the need for traditional surgical therapy.

  18. Comparison of Stabilisation/Solidificationtreatments of hazardous waste materials

    NARCIS (Netherlands)

    Felix, F.; Fraaij, A.L.A.; Hendriks, Ch.F.

    In this paper the advantages en disadvantages of three different Stabilisation/Solidification-treatments are discussed. The first treatment, cement based SIS-treatment, is based on the hydration reaction of cement by which heavy metals chemically and or physically are bound. Cement based

  19. TOF-SIMS studies of yttria-stabilised zirconia

    DEFF Research Database (Denmark)

    Hansen, Karin Vels; Norrman, Kion; Mogensen, Mogens Bjerg

    2006-01-01

    The surface of an as-polished and an as-sintered yttria-stabilised zirconia pellet was analysed with XPS and TOF-SIMS (depth profiling and imaging) in order to study the distribution of impurities. The polished sample was slightly contaminated with Na, K, Mg and Ca. The sintered sample showed...

  20. Modelling and experiments on NTM stabilisation at ASDEX upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Urso, Laura

    2009-07-27

    In the next fusion device ITER the so-called neoclassical tearing modes (NTMs) are foreseen as being extremely detrimental to plasma confinement. This type of resistive instability is related to the presence in the plasma of magnetic islands. These are experimentally controlled with local electron cyclotron current drive (ECCD) and the island width decay during NTM stabilisation is modelled using the so-called Modified Rutherford equation. In this thesis, a modelling of the Modified Rutherford equation is carried out and simulations of the island width decay are compared with the experimentally observed ones in order to fit the two free machine-independent parameters present in the equation. A systematic study on a database of NTM stabilisation discharges from ASDEX Upgrade and JT-60U is done within the context of a multi-machine benchmark for extrapolating the ECCD power requirements for ITER. The experimental measurements in both devices are discussed by means of consistency checks and sensitivity analysis and used to evaluate the two fitting parameters present in the Modified Rutherford equation. The influence of the asymmetry of the magnetic island on stabilisation is for the first time included in the model and the effect of ECCD on the marginal island after which the mode naturally decays is quantified. The effect of radial misalignment and over-stabilisation during the experiment are found to be the key quantities affecting the NTM stabilisation. As a main result of this thesis, the extrapolation to ITER of the NTM stabilisation results from ASDEX Upgrade and JT-60U shows that 10MW of ECCD power are enough to stabilise large NTMs as long as the O-point of the island and the ECCD beam are perfectly aligned. In fact, the high ratio between the island size at saturation and the deposition width of the ECCD beam foreseen for ITER is found to imply a maximum allowable radial misalignment of 2-3 cm and little difference in terms of gained performance between

  1. Evaluation of surgical strategy of conventional vs. percutaneous robot-assisted spinal trans-pedicular instrumentation in spondylodiscitis.

    Science.gov (United States)

    Keric, Naureen; Eum, David J; Afghanyar, Feroz; Rachwal-Czyzewicz, Izabela; Renovanz, Mirjam; Conrad, Jens; Wesp, Dominik M A; Kantelhardt, Sven R; Giese, Alf

    2017-03-01

    Robot-assisted percutaneous insertion of pedicle screws is a recent technique demonstrating high accuracy. The optimal treatment for spondylodiscitis is still a matter of debate. We performed a retrospective cohort study on surgical patients treated with pedicle screw/rod placement alone without the application of intervertebral cages. In this collective, we compare conventional open to a further minimalized percutaneous robot-assisted spinal instrumentation, avoiding a direct contact of implants and infectious focus. 90 records and CT scans of patients treated by dorsal transpedicular instrumentation of the infected segments with and without decompression and antibiotic therapy were analysed for clinical and radiological outcome parameters. 24 patients were treated by free-hand fluoroscopy-guided surgery (121 screws), and 66 patients were treated by percutaneous robot-assisted spinal instrumentation (341 screws). Accurate screw placement was confirmed in 90 % of robot-assisted and 73.5 % of free-hand placed screws. Implant revision due to misplacement was necessary in 4.95 % of the free-hand group compared to 0.58 % in the robot-assisted group. The average intraoperative X-ray exposure per case was 0.94 ± 1.04 min in the free-hand group vs. 0.4 ± 0.16 min in the percutaneous group (p = 0.000). Intraoperative adverse events were observed in 12.5 % of free-hand placed pedicle screws and 6.1 % of robot robot-assisted screws. The mean postoperative hospital stay in the free-hand group was 18.1 ± 12.9 days, and in percutaneous group, 13.8 ± 5.6 days (p = 0.012). This study demonstrates that the robot-guided insertion of pedicle screws is a safe and effective procedure in lumbar and thoracic spondylodiscitis with higher accuracy of implant placement, lower radiation dose, and decreased complication rates. Percutaneous spinal dorsal instrumentation seems to be sufficient to treat lumbar and thoracic spondylodiscitis.

  2. Food-grade Pickering emulsions stabilised with solid lipid particles.

    Science.gov (United States)

    Pawlik, Aleksandra; Kurukji, Daniel; Norton, Ian; Spyropoulos, Fotis

    2016-06-15

    Aqueous dispersions of tripalmitin particles (with a minimum size of 130 nm) were produced, via a hot sonication method, with and without the addition of food-grade emulsifiers. Depending on their relative size and chemistry, the emulsifiers altered the properties of the fat particles (e.g. crystal form, dispersion state and surface properties) by two proposed mechanisms. Firstly, emulsifiers modify the rate and/or extent of polymorphic transitions, resulting in the formation of fat crystals with a range of polarities. Secondly, the adsorption of emulsifiers at the particle interface modifies crystal surface properties. Such emulsifier-modified fat particles were then used to stabilise emulsions. As the behaviour of these particles was predisposed by the kind of emulsifier employed for their manufacture, the resulting particles showed different preferences to which of the emulsion phases (oil or water) became the continuous one. The polarity of the fat particles decreased as follows: Whey Protein Isolate > Soy Lecithin > Soy Lecithin + Tween 20 > Tween 20 > Polyglycerol Polyricinoleate > no emulsifier. Consequently, particles stabilised with WPI formed oil-in-water emulsions (O/W); particles stabilised solely with lecithin produced a highly unstable W/O emulsion; and particles stabilised with a mixture of lecithin and Tween 20 gave a stable W/O emulsion with drop size up to 30 μm. Coalescence stable, oil-continuous emulsions (W/O) with drop sizes between 5 and 15 μm were produced when the tripalmitin particles were stabilised with solely with Tween 20, solely with polyglycerol polyricinoleate, or with no emulsifier at all. It is proposed that the stability of the latter three emulsions was additionally enhanced by sintering of fat particles at the oil-water interface, providing a mechanical barrier against coalescence.

  3. Active aerodynamic stabilisation of long suspension bridges

    DEFF Research Database (Denmark)

    Nissen, Henrik Ditlev; Sørensen, Paul Haase; Jannerup, Ole Erik

    2004-01-01

    The paper describes the addition of actively controlled appendages (flaps) attached along the length of the bridge deck to dampen wind-induced oscillations in long suppension bridges. A novel approach using control systems methods for the analysis of dynamic stability is presented. In order to ma...

  4. Active aerodynamic stabilisation of long suspension bridges

    DEFF Research Database (Denmark)

    Nissen, Henrik Ditlev; Sørensen, Paul Haase; Jannerup, Ole Erik

    2004-01-01

    The paper describes the addition of actively controlled appendages (flaps) attached along the length of the bridge deck to dampen wind-induced oscillations in long suppension bridges. A novel approach using control systems methods for the analysis of dynamic stability is presented. In order to ma...

  5. Treatment of acute thoracolumbar burst fractures with kyphoplasty and short pedicle screw fixation: Transpedicular intracorporeal grafting with calcium phosphate: A prospective study

    Directory of Open Access Journals (Sweden)

    Korovessis Panagiotis

    2007-01-01

    Full Text Available Background: In the surgical treatment of thoracolumbar fractures, the major problem after posterior correction and transpedicular instrumentation is failure to support the anterior spinal column, leading to loss of correction and instrumentation failure with associated complaints. We conducted this prospective study to evaluate the outcome of the treatment of acute thoracolumbar burst fractures by transpedicular balloon kyphoplasty, grafting with calcium phosphate cement and short pedicle screw fixation plus fusion. Materials and Methods : Twenty-three consecutive patients of thoracolumbar (T 9 to L 4 burst fracture with or without neurologic deficit with an average age of 43 years, were included in this prospective study. Twenty-one from the 23 patients had single burst fracture while the remaining two patients had a burst fracture and additionally an adjacent A1-type fracture. On admission six (26% out of 23 patients had neurological deficit (five incomplete, one complete. Bilateral transpedicular balloon kyphoplasty with liquid calcium phosphate to reduce segmental kyphosis and restore vertebral body height and short (three vertebrae pedicle screw instrumentation with posterolateral fusion was performed. Gardner kyphosis angle, anterior and posterior vertebral body height ratio and spinal canal encroachment were calculated pre- to postoperatively. Results : All 23 patients were operated within two days after admission and were followed for at least 12 months after index surgery. Operating time and blood loss averaged 45 min and 60 cc respectively. The five patients with incomplete neurological lesions improved by at least one ASIA grade, while no neurological deterioration was observed in any case. The VAS and SF-36 (Role physical and Bodily pain domains were significantly improved postoperatively. Overall sagittal alignment was improved from an average preoperative 16° to one degree kyphosis at final follow-up observation. The anterior

  6. Transmissibility-Based Operational Modal Analysis: Enhanced Stabilisation Diagrams

    Directory of Open Access Journals (Sweden)

    Gert De Sitter

    2012-01-01

    Full Text Available Recently it has been shown that also transmissibilities can be used to identify the modal parameters. This approach has several advantages: because of the deterministic character of the transmissibility functions, the estimated parameters are more accurate than the results obtained with the power spectra based operational modal analysis techniques. Another advantage is that the transmissibility functions do not depend on the colouring of the unknown forces. A disadvantage of the transmissibility based operational modal analysis techniques is that non-physical modes show up in the stabilisation diagrams. In this contribution it will first be shown that those non-physical modes will show up when traditional stabilisation diagrams are used. In a second step, a new approach of selecting the physical modes out of a set of estimated modes will be discussed and the new approach will be validated using data generated with an acoustical Finite Element Model. Finally, the approach will be validated using real acoustical data.

  7. Lactose fermentation at Camembert, made by classic and stabilised

    Directory of Open Access Journals (Sweden)

    Bogdan Perko

    2002-01-01

    Full Text Available In our experiments the fermentation of lactose at Camembert type cheese by classic and stabilised technology was monitored. In each of the two technologies two experiments were made. The difference between these two technologies is in pH level, which drops below 5 by classic technology and remains above 5 by stabilised technology at all times. To achieve the criteria of stabilised technology the fermentation was stopped at a desired level of pH, by dropping the cheese in brine at 14 °C. After salting and moulding cheesewas transferred from the first three experiments into a ripening chamber at 11 °C. With the last experiment (stabilised technology the cheese ripened for 3 days at 5 °C. During ripening process pH dropped below 5 in all experiments. The process of fermentation was performed by the following lactic acid bacteria: Streptococcus thermophilus, Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris. As these lactic acid bacteria ferment differently D-galactose during manufacture and ripening process, the contentof lactose and D-galactose was measured. Based on the results of our research the following conclusion can be made: the action of lactic acid bacteria can not be stropped even at 5 °C. The native microflora, which remains in the milk after thermisation, might be responsible for the fermentation of Dgalactose. It could be possible that the Streptococcus thermophilus enzymes were not inactivated, causing continuation of lactose fermentation even at low temperature. Mesophilic lactococci were inhibited and for that reason Dgalactose accumulated in cheese. Only after cheese were transferred into a ripening chamber at 11 °C and with low lactose concentration in medium left, mesophilic lactococci started to ferment D-galactose.

  8. From stringy particle physics to moduli stabilisation and cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Honecker, Gabriele [Institute for Physics (WA THEP) and Cluster of Excellence PRISMA, Johannes Gutenberg University, Mainz (Germany)

    2016-04-15

    Intersecting D6-branes provide a geometrically intuitive road to stringy particle physics models, where D6-branes stuck at orbifold singularities can lead to the stabilisation of deformation moduli, and the QCD axion can arise from the open string sector in a very constrained way compared to pure field theory. We demonstrate this interplay of different physical features here through an explicit model. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. [A difficult stabilisation. Chlorpromazine in the fifties in Belgium].

    Science.gov (United States)

    Majerus, Benoît

    2010-01-01

    Through a Belgian case study the article tries to trace the gradual stabilisation of chlorpromazine as an antipsychotic in the 1950s. By varying ranges and angles of approach it shows the heterogeneity of actors involved and the semantic bricolage that accompany the marketing of the first antipsychotic. Far from being a revolution, the presence of Largactil in psychiatric practice is rather characterised by integration into a wider range of medicines and sinuous searching to give sense to this new drug.

  10. Wavelength stabilisation during current pulsing of tapered laser

    DEFF Research Database (Denmark)

    Jensen, Ole Bjarlin

    2009-01-01

    The use of external feedback to stabilise the frequency of a tapered laser during current pulsing is reported. Using this technique more than 20 W of peak power in 60 ns pulses from the tapered laser is obtained and owing to the external feedback, the laser is tunable in the 778-808 nm range....... The spectral width of the tapered laser is significantly narrowed compared to the freely running laser....

  11. Interplay between body stabilisation and quadriceps muscle activation capacity.

    Science.gov (United States)

    Bampouras, Theodoros M; Reeves, Neil D; Baltzopoulos, Vasilios; Maganaris, Constantinos N

    2017-03-22

    The study aimed to distinguish the effect of stabilisation and muscle activation on quadriceps maximal isometric voluntary contraction (MVC) torque generation. Nine subjects performed (a) an MVC with restrained leg and pelvis (Typical MVC), (b) a Typical MVC with handgrip (Handgrip MVC), (c) an MVC focusing on contracting the knee extensors only (Isolated knee extension MVC), and (d) an MVC with unrestrained leg and pelvis (Unrestrained MVC). Torque and activation capacity between conditions were compared with repeated measures ANOVA and dependent t-tests. EMG (from eleven remote muscles) was compared using Friedman's and Wilcoxon. Typical MVC (277.2±49.6Nm) and Handgrip MVC (261.0±55.4Nm) were higher than Isolated knee extension MVC (210.2±48.3Nm, pMVC (195.2±49.7Nm, pMVC (83.1±15.9%) activation was higher than Isolated knee extension MVC (68.9±24.3%, pMVC and Handgrip MVC (81.8±17.4%) were higher than Unrestrained MVC (64.9±16.2%, pMVC consistently lower than Typical MVC or Handgrip MVC. Stabilisation of the involved segments is the prime concern allowing fuller activation of the muscle, reinforcing the need for close attention to stabilisation during dynamometry-based knee joint functional assessment.

  12. Preparing Stabilisation for 21st Century Security Challenges

    Directory of Open Access Journals (Sweden)

    Steven A. Zyck

    2015-11-01

    Full Text Available Stabilisation, as a concept and set of practices, has proliferated over the past two decades and is now implicitly integrated into a range of global frameworks. However, this enthusiasm has at times risked turning this increasingly common, albeit contested, idea into a piece of jargon that discounts its unique facets: a focus on all sorts of violence, not just conflict, that create political instability and human harm and a problem-solving approach that draws selectively on various forms of intervention (e.g., statebuilding, counterinsurgency, peacekeeping, etc. without being beholden to any one toolkit. The pragmatism inherent within the concept of stabilisation will grow increasingly important as new security challenges emerge or proliferate. These include the fragmentation and regionalisation of conflict systems, transnational organised crime, large-scale migration and new, disruptive technologies. Novel approaches rooted in big data and technology will increasingly need to be applied. Most importantly, in foreign policy, military and development communities often driven by perceptions about what causes, ends or prevents violence, stabilisation must maintain its agnostic, problem-solving roots and allegiance to evidence over ideology.

  13. Solvent mediated stabilisation of dissolution at the resorcinol-water interface

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, M.; Sahudin, S. [Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur (Malaysia)

    2010-02-15

    Experimental evidence suggests dissolution along the polar c-axis of {alpha}-resorcinol in water preferentially occurs at the {l_brace}011{r_brace} surface. In an attempt to understand the mechanism by which solvent influences this process, dissolution at the resorcinol {l_brace}011{r_brace} and {l_brace}011{r_brace} surfaces has been studied using molecular dynamics simulations. Our computations indicate dissolution at the two faces is dependent upon solvent behaviour at the crystal surface, where strong water-crystal interactions serve to stabilise the crystal surface and retard dissolution. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. Oil-in-oil emulsions stabilised solely by solid particles.

    Science.gov (United States)

    Binks, Bernard P; Tyowua, Andrew T

    2016-01-21

    A brief review of the stabilisation of emulsions of two immiscible oils is given. We then describe the use of fumed silica particles coated with either hydrocarbon or fluorocarbon groups in acting as sole stabilisers of emulsions of various vegetable oils with linear silicone oils (PDMS) of different viscosity. Transitional phase inversion of emulsions, containing equal volumes of the two oils, from silicone-in-vegetable (S/V) to vegetable-in-silicone (V/S) occurs upon increasing the hydrophobicity of the particles. Close to inversion, emulsions are stable to coalescence and gravity-induced separation for at least one year. Increasing the viscosity of the silicone oil enables stable S/V emulsions to be prepared even with relatively hydrophilic particles. Predictions of emulsion type from calculated contact angles of a silica particle at the oil-oil interface are in agreement with experiment provided a small polar contribution to the surface energy of the oils is included. We also show that stable multiple emulsions of V/S/V can be prepared in a two-step procedure using two particle types of different hydrophobicity. At fixed particle concentration, catastrophic phase inversion of emulsions from V/S to S/V can be effected by increasing the volume fraction of vegetable oil. Finally, in the case of sunflower oil + 20 cS PDMS, the study is extended to particles other than silica which differ in chemical type, particle size and particle shape. Consistent with the above findings, we find that only sufficiently hydrophobic particles (clay, zinc oxide, silicone, calcium carbonate) can act as efficient V/S emulsion stabilisers.

  15. Simple intervention to reduce mosquito breeding in waste stabilisation ponds

    DEFF Research Database (Denmark)

    Ensink, Jeroen H J; Mukhtar, Muhammad; van der Hoek, Wim

    2007-01-01

    Waste stabilisation ponds (WSP) are the preferred method for treatment of urban wastewater in low-income countries but, especially in arid regions, the pond systems can be important breeding sites for mosquitoes of medical importance. In a WSP system in Faisalabad, Pakistan, we assessed the impact...... of simple environmental interventions on mosquito occurrence and abundance. Reducing the amount of floating matter in the ponds, eliminating emergent vegetation and repairing cracks in the cement structure reduced the number of mosquito-positive samples in the intervention ponds to almost zero, whereas...

  16. Nordic regionalisation of a greenhouse-gas stabilisation scenario

    Energy Technology Data Exchange (ETDEWEB)

    Wyser, Klaus; Rummukainen, Markku; Strandberg, Gustav

    2006-10-15

    The impact of a CO{sub 2} stabilisation on the Swedish climate is investigated with the regional climate model RCA3 driven by boundary conditions obtained from a global coupled climate system model (CCSM3). The global model has been forced with observed greenhouse gas concentrations from pre-industrial conditions until today's, and with an idealised further increase until the stabilisation level is reached. After stabilisation the model integration continues for another 150+ years in order to follow the delayed response of the climate system over a period of time. Results from the global and regional climate model are compared against observations and ECMWF reanalysis for 1961-1990. For this period, the global model is found to be too cold over Europe and with a zonal flow from the North Atlantic towards Europe that is too strong. The climate of the driving global model controls the climate of the regional model and the same deviations from one are thus inherited by the other. We therefore analyse the relative climate changes differences, or ratios, of climate variables between future's and today's climate. Compared to pre-industrial conditions, the global mean temperature changes by about 1.5 deg C as a result of the stabilisation at 450 ppmv equivalent CO{sub 2}. Averaged over Europe, the temperature change is slightly larger, and it is even larger for Sweden and Northern Europe. Annual mean precipitation for Europe is unaffected, but Sweden receives more precipitation under higher CO{sub 2} levels. The inter-annual and decadal variability of annual mean temperature and precipitation does not change with any significant degree. The changes in temperature and precipitation are not evenly distributed with the season: the largest warming and increased precipitation in Northern Europe occurs during winter months while the summer climate remains more or less unchanged. The opposite is true for the Mediterranean region where the precipitation decreases

  17. Small-State Special Operations in a Comprehensive Stabilisation Context

    DEFF Research Database (Denmark)

    Johnsen, Anton Asklund

    the most important arguments, reflections and conclusion made at the conference. The conference was initiated in order to establish an academic forum, wherein relevant questions could be posed which would allow to pinpoint and guide future research on the utility of small state operations. The key...... takeaways were: Special operations as a force multiplier: Can special operations enable other stabilisation agents, locals as well as internationals, to accomplish their missions more effectively? This includes NGOs, diplomats or other officials, other military units, etc. How can the mindset required...

  18. Fast control strategy for stabilising fixed-speed induction-generator-based wind turbines in an islanded distributed system

    DEFF Research Database (Denmark)

    Wei, Mu; Chen, Zhe

    2013-01-01

    wind generator cutting off. This study investigates and analyses the dynamic characteristics of an FSWT to reveal the behaviours of an FSWT under disturbances. Then a fast control strategy for stabilising an islanded DGS is proposed. The main contributions of the control strategy are: the total amount...... of reactive power compensation and load shedding may be determined precisely; all the operation execution points may be decided accurately to improve DGS stability. Furthermore, the implementation of the fast control strategy is also discussed. A case study is presented to demonstrate the effectiveness...

  19. Design for the Control of a Rotatable Stabiliser

    CERN Document Server

    Childs, S J

    2014-01-01

    This research sets out a design for the control of a rotatable stabiliser which, it is proposed, might augment, or fully replace, the conventional control mechanisms for pitch and yaw in aircraft. The anticipated advantages of such a device are around 25% less drag, for a capability which ranges between equivalent and greater than twofold that of the conventional tail. One, anticipated handicap of such a device is the potential for it to stall, from its tips, inward, if rotated too fast. For succinctness, a mapping betweeen states of the device and the position of a two-axis controller (e.g. a joystick) is formulated. The function of the joystick traditionally assigned to the control of ailerons is replaced by that traditionally associated with the rudder pedals. Its function is otherwise conventional. From this topology it follows that small and continuous adjustments of the controls should cause the stabiliser to rotate in a direction opposite to that of the joystick (when viewed from aft) and the deflectio...

  20. Investigations on aged Ti-stabilised stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Ehrnsten, U.; Karjalainen-Roikonen, P.; Nenonen, P. [VTT Industrial Systems, Espoo (Finland); Korhonen, R. [Fortum Nuclear Services, Vantaa (Finland); Timofeev, B.T.; Bloomin, A.A. [ZNIIKM, St. Petersburg (Russian Federation)

    2003-03-01

    Mechanical and microstructural properties of cast material of type O8X8H10TL and wrought and welded stainless steel pipe material of type O8X8H10T have been determined, aged at NPP operation temperature for about 100 000 h and 200 000 h, respectively. The mechanical properties were determined using tensile testing, impact energy determination and fracture resistance testing. The microstructures were studied using optical, scanning and transmission electron microscopy. The mechanical properties of the cast Ti-stabilised stainless steel material are evaluated to be only slightly affected by long term ({approx} 100 000 hours) operation at NPP operation temperature. Also the effect of even longer ({approx} 200 000 hours) operation on wrought Ti-stabilised pipe material is very small, as the properties of the aged material are within the normal range of as-manufactured material. The mechanical properties of the Mo-alloyed stainless steel weld metal after {approx} 200 000 hours of operation are still good, although indications of changes due to thermal ageing were observed. (orig.)

  1. Stabilising emulsion-based colloidal structures with mixed food ingredients.

    Science.gov (United States)

    Dickinson, Eric

    2013-03-15

    The physical scientist views food as a complex form of soft matter. The complexity has its origin in the numerous ingredients that are typically mixed together and the subtle variations in microstructure and texture induced by thermal and mechanical processing. The colloid science approach to food product formulation is based on the assumption that the major product attributes such as appearance, rheology and physical stability are determined by the spatial distribution and interactions of a small number of generic structural entities (biopolymers, particles, droplets, bubbles, crystals) organised in various kinds of structural arrangements (layers, complexes, aggregates, networks). This review describes some recent advances in this field with reference to three discrete classes of dispersed systems: particle-stabilised emulsions, emulsion gels and aerated emulsions. Particular attention is directed towards explaining the crucial role of the macromolecular ingredients (proteins and polysaccharides) in controlling the formation and stabilisation of the colloidal structures. The ultimate objective of this research is to provide the basic physicochemical insight required for the reliable manufacture of novel structured foods with an appealing taste and texture, whilst incorporating a more healthy set of ingredients than those found in many existing traditional products.

  2. Is coracoclavicular stabilisation alone sufficient for the endoscopic treatment of severe acromioclavicular joint dislocation (Rockwood types III, IV, and V)?

    Science.gov (United States)

    Barth, J; Duparc, F; Andrieu, K; Duport, M; Toussaint, B; Bertiaux, S; Clavert, P; Gastaud, O; Brassart, N; Beaudouin, E; De Mourgues, P; Berne, D; Bahurel, J; Najihi, N; Boyer, P; Faivre, B; Meyer, A; Nourissat, G; Poulain, S; Bruchou, F; Ménard, J F

    2015-12-01

    The primary objective was to evaluate correlations linking anatomical to functional outcomes after endoscopically assisted repair of acute acromioclavicular joint dislocation (ACJD). Combined acromioclavicular and coracoclavicular stabilisation improves radiological outcomes compared to coracoclavicular stabilisation alone. A prospective multicentre study was performed. Clinical outcome measures were pain intensity on a visual analogue scale (VAS), subjective functional impairment (QuickDASH score), and Constant's score. Anatomical outcomes were assessed on standard radiographs (anteroposterior view of the acromioclavicular girdle and bilateral axillary views) obtained preoperatively and postoperatively and on postoperative dynamic radiographs taken as described by Tauber et al. Of 116 patients with acute ACJD included in the study, 48% had type III, 30% type IV, and 22% type V ACJD according to the Rockwood classification. Coracoclavicular stabilisation was achieved using a double endobutton in 93% of patients, and concomitant acromioclavicular stabilisation was performed in 50% of patients. The objective functional outcome was good, with an unweighted Constant's score ≥ 85/100 and a subjective QuickDASH functional disability score ≤ 10 in 75% of patients. The radiographic analysis showed significant improvements from the preoperative to the 1-year postoperative values in the vertical plane (decrease in the coracoclavicular ratio from 214 to 128%, p=10(-6)) and in the horizontal plane (decrease in posterior displacement from 4 to 0mm, p=5×10(-5)). The anatomical outcome correlated significantly with the functional outcome (absolute R value=0.19 and p=0.045). We found no statistically significant differences across the various types of constructs used. Intra-operative control of the acromioclavicular joint did not improve the result. Implantation of a biological graft significantly improved both the anatomical outcome in the vertical plane (p=0.04) and

  3. Determination of Stabiliser Contents in Advanced Gun Propellants by Reverse Phase High Performance Liquid Chromatography

    Science.gov (United States)

    1994-03-01

    HIGH PERFORMANCE LIQUID CHROMATOGRAPHY N"m A.R. TURNER AND A. WHITE...TO biEPROOU.; AND SELL THIS REPORT Determination of Stabiliser Contents in Advanced Gun Propellants by Reverse Phase High Performance Liquid Chromatography A.R...8217/......... .. Availability Cooes Dist Avaiardlo A-i Determination of Stabiliser Contents in Advanced Gun Propellants by Reverse Phase High Performance Liquid Chromatography

  4. Stabilisation of liquid-air surfaces by particles of low surface energy.

    Science.gov (United States)

    Binks, Bernard P; Rocher, Anaïs

    2010-08-28

    We describe the stabilisation of liquid-air surfaces by microparticles of a low surface energy solid. By varying the surface tension of the liquid, various particle-stabilised materials from oil dispersions to air-in-oil foams to dry water can be prepared.

  5. Quantifying lingual coarticulation using ultrasound imaging data collected with and without head stabilisation.

    Science.gov (United States)

    Zharkova, Natalia; Gibbon, Fiona E; Hardcastle, William J

    2015-04-01

    Previous studies reporting the use of ultrasound tongue imaging with clinical populations have generally provided qualitative information on tongue movement. Meaningful quantitative measures for use in the clinic typically require the speaker's head to be stabilised in relation to a transducer, which may be uncomfortable, and unsuitable for young children. The objective of this study was to explore the applicability of quantitative measurements of stabilisation-free tongue movement data, by comparing ultrasound data collected from 10 adolescents, with and without head stabilisation. Several measures of tongue shape were used to quantify coarticulatory influence from two contrasting vowels on four different consonants. Only one of the measures was completely unaffected by the stabilisation condition for all the consonants. The study also reported cross-consonant differences in vowel-related coarticulatory effects. The implications of the findings for the theory of coarticulation and for potential applications of stabilisation-free tongue curve measurements in clinical studies are discussed.

  6. Study of Trajectory of Spin-Stabilised Artillery Projectiles

    Directory of Open Access Journals (Sweden)

    M. Krishnamurthy

    1991-10-01

    Full Text Available Equations of motion for conventional spin-stabilised artillery projectile have been derived using a pseudo-stability axes system in addition to body-fixed and space-fixed axes systems. The aerodynamic forces and moments have been represented by their respective coefficients and the effects of Mach number and Reynolds number have been suitably accounted. The magnus terms which are significant at high rates of spin are estimated using a simple model. The set of equations have been partly linearised and solved numerically for a typical projectile using NAG system routines. Various trajectory parameters are computed and compared with the range-table data for the projectile. A parametric study had been carried out varying the aerodynamic coefficients to understand the sensitivity of the results obtained.

  7. Chinese Macroeconomic Stabilisation and Reform: A Briefing Note

    Institute of Scientific and Technical Information of China (English)

    BryaneMichael

    2004-01-01

    While reform of the Chinese public and external sectors has promoted growth, it has also led to increasing macroeconomic volatility. Such volatility has largely been due to China's de facto administrative and fiscal decentralisation and its de jure attempts at reasserting central control through fiscal and commercial regulation. Section Ⅱ will discuss some reasons for China's rapid economic growth and discuss the macro-level influences which caused output and inflation instability in the period 1979-1996. Section Ⅲ will discuss the effects of public sector reform on output and prices. Section Ⅳ will explore trade reform's effects on output and prices. The conclusion will discuss implications for stabilisation -where “stabilisation” is taken to comprise economic policies aimed at reducing inflation while promoting long-term output growth.

  8. Stabilising compensators for linear time-varying differential systems

    Science.gov (United States)

    Oberst, Ulrich

    2016-04-01

    In this paper, we describe a constructive test to decide whether a given linear time-varying (LTV) differential system admits a stabilising compensator for the control tasks of tracking, disturbance rejection or model matching and construct and parametrise all of them if at least one exists. In analogy to the linear time-invariant (LTI) case, the ring of stable rational functions, noncommutative in the LTV situation, and the Kučera-Youla parametrisation play prominent parts in the theory. We transfer Blumthaler's thesis from the LTI to the LTV case and sharpen, complete and simplify the corresponding results in the book 'Linear Time-Varying Systems' by Bourlès and Marinescu.

  9. Recycling vs. stabilisation of soil sugars - a long-term laboratory incubation experiment

    Science.gov (United States)

    Basler, A.; Dippold, M.; Helfrich, M.; Dyckmans, J.

    2015-06-01

    Independent of its chemical structure carbon (C) persists in soil for several decades, controlled by stabilisation and recycling. To disentangle the importance of the two factors on the turnover dynamics of soil sugars, an important compound of soil organic matter (SOM), a three year incubation experiment was conducted on a silty loam soil under different types of land use (arable land, grassland and forest) by adding 13C-labeled glucose. The compound specific isotope analysis of soil sugars was used to examine the dynamics of different sugars during incubation. Sugar dynamics were dominated by a pool of high mean residence times (MRT) indicating that recycling plays an important role for sugars. However, this was not substantially affected by soil C content. Six months after label addition the contribution of the label was much higher for microbial biomass than for CO2 production for all examined soils, corroborating that substrate recycling was very effective within the microbial biomass. Two different patterns of tracer dynamics could be identified for different sugars: while fucose (fuc) and mannose (man) showed highest label contribution at the beginning of the incubation with a subsequent slow decline, galactose (gal) and rhamnose (rha) were characterised by slow label incorporation with subsequently constant levels, which indicates that recycling is dominating the dynamics of these sugars. This may correspond to (a) different microbial growing strategies (r and K-strategist) or (b) location within or outside the cell membrane (lipopolysaccharides vs. exopolysaccharides) and thus be subject of different re-use within the microbial food web. Our results show how the microbial community recycles substrate very effectively and that high losses of substrate only occur during initial stages after substrate addition.

  10. Stabilisation of MSWI bottom ash with sulphide-rich anaerobic effluent.

    Science.gov (United States)

    Sivula, Leena; Väisänen, Ari; Rintala, Jukka

    2008-03-01

    Effluent of an anaerobic sulphate-reducing wastewater treatment process was used to stabilise bottom ash. The effect of stabilisation on the concentration and binding of Ca, P, S, Cu, Pb, Zn, As, Cr, and Mo were studied by comparing results of sequential extraction from fresh and stabilised bottom ash. The stabilisation treatment improved the retention of Ca, Cu, Pb, S, and Zn in bottom ash compared to a treatment with ion-exchanged water. In addition to retention, Cu, S, and Zn were accumulated from the anaerobic effluent in the bottom ash. Concentrations of As, Cr, and Mo remained on the same level, whereas leaching of P increased compared to control treatment with ion-exchanged water. Improved retention and accumulation were the result of increased binding to less soluble fractions. The highest increases were in the sulphide and organic carbon bound fraction and in the carbonate fraction. Enhanced carbonation was probably due to CO2 deriving from the degradation of organic carbon. Flushing of stabilised bottom ash with ion-exchanged water ensured that the observed changes were not easily reversed. Most of the sulphide in the anaerobic effluent was removed when it was passed through bottom ash. The objective was to study the feasibility of sulphide-rich anaerobic effluent in bottom ash stabilisation and changes in the binding of the elements during stabilisation. In addition, the ability of the process to remove sulphide from the effluent was observed.

  11. On matrix stabilisation of d- and f-transition metal ions in unstable oxidation states

    Energy Technology Data Exchange (ETDEWEB)

    Kiselev, Yurii M [Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow (Russian Federation)

    2009-01-31

    The state-of-the-art in matrix stabilisation of d- and f-transition metal ions in unstable oxidation states is analysed. Main aspects of this problem concerning the genealogy of appropriate matrix systems are classified. Relevant examples are given and the data that contradict the scheme proposed are discussed. The thermodynamics of the matrix stabilisation effect is considered using the concept of isomorphic miscibility. The influence of defects and non-equilibrium on the matrix stabilisation effect is discussed. The problem of identification of the oxidation states in matrix systems is examined and various types of matrix systems are considered.

  12. State-feedback stabilisation for stochastic non-holonomic mobile robots with uncertain visual servoing parameters

    Science.gov (United States)

    Zhang, Dongkai; Wang, Chaoli; Wei, Guoliang; Zhang, Hengjun; Chen, Hua

    2014-07-01

    The stabilising problem of stochastic non-holonomic mobile robots with uncertain parameters based on visual servoing is addressed in this paper. The model of non-holonomic mobile robots based on visual servoing is extended to the stochastic case, where their forward velocity and angular velocity are both subject to some stochastic disturbances. Based on backstepping technique, state-feedback stabilising controllers are designed for stochastic non-holonomic mobile robots. A switching control strategy for the original system is presented. The proposed controllers guarantee that the closed-loop system is asymptotically stabilised at the zero equilibrium point in probability.

  13. stabilisation of niger delta fat clay with blend of binders for subgrade ...

    African Journals Online (AJOL)

    HOD

    3, FACULTY OF ENGINEERING,RIVERS STATE UNIVERSITY OF SCIENCE AND ... Construction of roads on fine-grained soils without any form of stabilisation is a major problem all over the ...... Regional Development Master Plan Chapter 1:.

  14. On Fluxed Instantons and Moduli Stabilisation in IIB Orientifolds and F-theory

    CERN Document Server

    Grimm, Thomas W; Palti, Eran; Weigand, Timo

    2011-01-01

    We study the superpotential induced by Euclidean D3-brane instantons carrying instanton flux, with special emphasis on its significance for the stabilisation of Kahler moduli and Neveu-Schwarz axions in Type IIB orientifolds. Quite generally, once a chiral observable sector is included in the compactification, arising on intersecting D7-branes with world-volume flux, resulting charged instanton zero modes prevent a class of instantons from participating in moduli stabilisation. We show that instanton flux on Euclidean D3-branes can remove these extra zero modes and helps in reinstating full moduli stabilisation within a geometric regime. We comment also on the F-theoretic description of this effect of alleviating the general tension between moduli stabilisation and chirality. In addition we propose an alternative solution to this problem based on dressing the instantons with charged matter fields which is unique to F-theory and cannot be realised in the weak coupling limit.

  15. Stabiliser Fault Emergency Control using Reconfiguration to Preserve Power System Stability

    DEFF Research Database (Denmark)

    Pedersen, Andreas Søndergaard; Richter, Jan H.; Tabatabaeipour, Mojtaba

    2014-01-01

    Stabiliser faults in multi-machine power systems are examined in this paper where fault-masking and system reconguration of the nonlinear system is obtained using a virtual actuator approach. Phasor Measurement Units, which can be integrated in wide-area transmission grids to improve...... the performance of power system stabilisers, are utilised when reconguring remaining stabilisers after one has been inoperable by a local failure. A stabilitypreserving reconguration is designed using absolute stability results for Lure type systems: The calculation of the virtual actuator that relies...... on a solution of a linear matrix inequality (LMI) is detailed in the paper. Simulation results of a benchmark transmission system show the ability of the fault-tolerant reconguration strategy to maintain wide-area stability of a power system despite failure in a stabiliser....

  16. Preconditioning of Nonlinear Mixed Effects Models for Stabilisation of Variance-Covariance Matrix Computations

    National Research Council Canada - National Science Library

    Aoki, Yasunori; Nordgren, Rikard; Hooker, Andrew C

    2016-01-01

    ... a bottleneck in the analysis. We propose a preconditioning method for non-linear mixed effects models used in pharmacometric analyses to stabilise the computation of the variance-covariance matrix...

  17. Transformation Directions of the Financial Policy in the Process of Stabilisation of the Ukrainian Economy

    Directory of Open Access Journals (Sweden)

    Petrushevska Viktoriya V.

    2013-11-01

    Full Text Available The goal of the article is consideration of theoretical provisions with respect to the state financial policy. The article considers the role of the financial policy in ensuring stabilisation of the Ukrainian financial system. It presents conceptual provisions regarding main goals, mechanisms and instruments of the stabilisation financial policy of the state. It develops economic indicators of its efficiency. The use of indicators of economic efficiency of the stabilisation financial policy by the bodies of state authority in their practical activity would provide the society with a possibility to assess expediency of measures of this policy increasing its efficiency and decreasing criticism at the government. A necessary direction of achievement of effectiveness and efficiency of the stabilisation financial policy is taking into consideration interests of all social groups (population, entrepreneurs, financial institutes and companies, etc. by the bodies of state authority in the process of its development and realisation.

  18. Embodied energy in cement stabilised rammed earth walls

    Energy Technology Data Exchange (ETDEWEB)

    Venkatarama Reddy, B.V.; Prasanna Kumar, P. [Department of Civil Engineering, Indian Institute of Science, Bangalore 560012 (India)

    2010-03-15

    Rammed earth walls are low carbon emission and energy efficient alternatives to load bearing walls. Large numbers of rammed earth buildings have been constructed in the recent past across the globe. This paper is focused on embodied energy in cement stabilised rammed earth (CSRE) walls. Influence of soil grading, density and cement content on compaction energy input has been monitored. A comparison between energy content of cement and energy in transportation of materials, with that of the actual energy input during rammed earth compaction in the actual field conditions and the laboratory has been made. Major conclusions of the investigations are (a) compaction energy increases with increase in clay fraction of the soil mix and it is sensitive to density of the CSRE wall, (b) compaction energy varies between 0.033 MJ/m{sup 3} and 0.36 MJ/m{sup 3} for the range of densities and cement contents attempted, (c) energy expenditure in the compaction process is negligible when compared to energy content of the cement and (d) total embodied energy in CSRE walls increases linearly with the increase in cement content and is in the range of 0.4-0.5 GJ/m{sup 3} for cement content in the rage of 6-8%. (author)

  19. Moduli stabilisation with nilpotent goldstino: vacuum structure and SUSY breaking

    Science.gov (United States)

    Aparicio, Luis; Quevedo, Fernando; Valandro, Roberto

    2016-03-01

    We study the effective field theory of KKLT and LVS moduli stabilisation scenarios coupled to an anti-D3-brane at the tip of a warped throat. We describe the presence of the anti-brane in terms of a nilpotent goldstino superfield in a supersymmetric effective field theory. The introduction of this superfield produces a term that can lead to a de Sitter minimum. We fix the Kähler moduli dependence of the nilpotent field couplings by matching this term with the anti-D3-brane uplifting contribution. The main result of this paper is the computation, within this EFT, of the soft supersymmetry breaking terms in both KKLT and LVS for matter living on D3-brane (leaving the D7-brane analysis to an appendix). A handful of distinct phenomenological scenarios emerge that could have low energy implications, most of them having a split spectrum of soft masses. Some cosmological and phenomenological properties of these models are discussed. We also check that the attraction between the D3-brane and the anti-D3-brane does not affect the leading contribution to the soft masses and does not destabilise the system.

  20. Moduli stabilisation with nilpotent goldstino: vacuum structure and SUSY breaking

    Energy Technology Data Exchange (ETDEWEB)

    Aparicio, Luis [ICTP,Strada Costiera 11, 34151 Trieste (Italy); Quevedo, Fernando [ICTP,Strada Costiera 11, 34151 Trieste (Italy); DAMTP, CMS, University of Cambridge,Wilberforce Road, Cambridge, CB3 0WA (United Kingdom); Valandro, Roberto [Dipartimento di Fisica dell’Università di Trieste,Strada Costiera 11, 34151 Trieste (Italy); INFN, Sezione di Trieste,Via Valerio 2, 34127 Trieste (Italy); ICTP,Strada Costiera 11, 34151 Trieste (Italy)

    2016-03-07

    We study the effective field theory of KKLT and LVS moduli stabilisation scenarios coupled to an anti-D3-brane at the tip of a warped throat. We describe the presence of the anti-brane in terms of a nilpotent goldstino superfield in a supersymmetric effective field theory. The introduction of this superfield produces a term that can lead to a de Sitter minimum. We fix the Kähler moduli dependence of the nilpotent field couplings by matching this term with the anti-D3-brane uplifting contribution. The main result of this paper is the computation, within this EFT, of the soft supersymmetry breaking terms in both KKLT and LVS for matter living on D3-brane (leaving the D7-brane analysis to an appendix). A handful of distinct phenomenological scenarios emerge that could have low energy implications, most of them having a split spectrum of soft masses. Some cosmological and phenomenological properties of these models are discussed. We also check that the attraction between the D3-brane and the anti-D3-brane does not affect the leading contribution to the soft masses and does not destabilise the system.

  1. Moduli Stabilisation with Nilpotent Goldstino: Vacuum Structure and SUSY Breaking

    CERN Document Server

    Aparicio, Luis; Valandro, Roberto

    2015-01-01

    We study the effective field theory of KKLT and LVS moduli stabilisation scenarios coupled to an anti-D3-brane at the tip of a warped throat. We describe the presence of the anti-brane in terms of a nilpotent goldstino superfield in a supersymmetric effective field theory. The introduction of this superfield produces a term that can lead to a de Sitter minimum. We fix the Kaehler moduli dependence of the nilpotent field couplings by matching this term with the anti-D3-brane uplifting contribution. The main result of this paper is the computation, within this EFT, of the soft supersymmetry breaking terms in both KKLT and LVS for matter living on D3-brane (leaving the D7-brane analysis to an appendix). A handful of distinct phenomenological scenarios emerge that could have low energy implications, most of them having a split spectrum of soft masses. Some cosmological and phenomenological properties of these models are discussed. We also check that the attraction between the D3-brane and the anti-D3-brane does n...

  2. Simultaneously stabilising controllers for time-varying linear systems within the framework of nest algebras

    Science.gov (United States)

    Wang, Hongzhu; Yu, Tianqiu; Xiao, Jinmei

    2016-08-01

    From the perspective of strong transitivity, a controller design method is provided to simultaneously stabilise a collection of time-varying linear systems within the framework of nest algebras. In particular, all simultaneously stabilising controllers for a class of linear plants are characterised based on the doubly coprime factorisations. These results hold as well in the time-invariant case. An illustrative example is given to demonstrate the validity of the method.

  3. Feedback control and output feedback control for the stabilisation of switched Boolean networks

    Science.gov (United States)

    Li, Fangfei; Yu, Zhaoxu

    2016-02-01

    This paper presents the feedback control and output feedback control for the stabilisation of switched Boolean network. A necessary condition for the existence of a state feedback controller for the stabilisation of switched Boolean networks under arbitrary switching signal is derived first, and constructive procedures for feedback control and output feedback control design are provided. An example is introduced to show the effectiveness of this paper.

  4. Global D-brane models with stabilised moduli and light axions

    CERN Document Server

    Cicoli, Michele

    2012-01-01

    We review recent attempts to try to combine global issues of string compactifications, like moduli stabilisation, with local issues, like semi-realistic D-brane constructions. We list the main problems encountered, and outline a possible solution which allows globally consistent embeddings of chiral models. We also argue that this stabilisation mechanism leads to an axiverse. We finally illustrate our general claims in a concrete example where the Calabi-Yau manifold is explicitly described by toric geometry.

  5. Design of a wind turbine pitch angle controller for power system stabilisation

    DEFF Research Database (Denmark)

    Jauch, Clemens; Islam, S.M.; Sørensen, Poul Ejnar

    2007-01-01

    The design of a PID pitch angle controller for a fixed speed active-stall wind turbine, using the root locus method is described in this paper. The purpose of this controller is to enable an active-stall wind turbine to perform power system stabilisation. For the purpose of controller design...... can effectively contribute to power system stabilisation. (c) 2007 Elsevier Ltd. All rights reserved....

  6. Phase Composition and Thermal Expansion of CaO Stabilised ZrO2 Refactories

    Institute of Scientific and Technical Information of China (English)

    ZHAOShike; WUJingyuan; 等

    2000-01-01

    In this,phase compsition and thermal expansion behaviour of CaO Stabilised refractories were studied,Special attention was paid to the expasion behaviour of three materials with different phase composition,The research results indicated that the expansion behaviour could be improved by modifying the stabilization of ZrO2,which thus leads to the increase in the thermal shock resistance and possibly eroion resistace of as-obtained CaO stabilised ZrO material.

  7. Development of guidelines for improved hydraulic design of waste stabilisation ponds.

    Science.gov (United States)

    Shilton, A; Harrison, J

    2003-01-01

    Pond hydraulic behaviour is influenced by the inlet/outlet configuration, baffles and wind, but design information relating to these factors is still very limited. This paper reviews the development of "Guidelines for the Improved Hydraulic Design of Waste Stabilisation Ponds" and summarises some of the key findings and recommendations. This work was based on review of previous research, laboratory experimentation, field studies and mathematical modelling using computational fluid dynamics. The inlet design can have a significant influence on the flow regime in a pond. Poorly considered positioning of the inlet and the outlet can create hydraulic short-circuiting problems. As an example of the nature of the work undertaken in this project, the use of a small horizontal inlet pipe was compared against a vertical inlet design. A practical method of assessing the relative significance of wind versus inlet power input was presented. The application of this analysis may allow engineers to size inlet pipes to help control the flow patterns in ponds for efficient performance. Extensive testing has been undertaken on a wide range of baffle configurations. An example of this research showed how short stub baffles could provide similar improvements to longer "traditional" baffle designs, potentially offering significant savings in construction costs. For traditional baffle designs a minimum of two baffles is recommended. For the pond modelled in this work, it was found that any more than four baffles gave only marginal improvements.

  8. Mixing and its impact on faecal coliform removal in a stabilisation pond.

    Science.gov (United States)

    Brissaud, F; Tournoud, M G; Drakides, C; Lazarova, V

    2003-01-01

    Faecal coliform removal in stabilisation ponds is highly dependent on shortest water retention times. Tracer tests have been performed in a 3,300 m2 and 1.0 m deep pond, located in Southern France, to measure the retention times and bring light on the main influencing factors and mechanisms. Tracer concentrations were monitored at the outlet and 60 locations within the pond--at the surface, mid depth and the bottom of the water column. Pond water temperatures were measured at different depths and locations, together with pH, DO and redox potential. Wind velocity and rainfall were recorded. Water quality was monitored at the inlet, outlet and within the pond. Water retention times were shown to be strongly affected by weather conditions. Windy periods appeared to favour mixing regardless of the season. In sunny periods of spring and summer, a clear stratification was observed during daytime and vanished gradually during the night, suggesting alternation of mixed and stratified hydrodynamic patterns. This alternation was shown to influence microorganism contents within and at the outlet of the pond. Accurate prediction of shortest water retention times and disinfection performance requires 3D unsteady state fluid dynamic models that are able to take the influence of wind and water temperature distribution into account.

  9. Nonlinear hydrodynamic and thermoacoustic oscillations of a bluff-body stabilised turbulent premixed flame

    Science.gov (United States)

    Lee, Chin Yik; Li, Larry Kin Bong; Juniper, Matthew P.; Cant, Robert Stewart

    2016-01-01

    Turbulent premixed flames often experience thermoacoustic instabilities when the combustion heat release rate is in phase with acoustic pressure fluctuations. Linear methods often assume a priori that oscillations are periodic and occur at a dominant frequency with a fixed amplitude. Such assumptions are not made when using nonlinear analysis. When an oscillation is fully saturated, nonlinear analysis can serve as a useful avenue to reveal flame behaviour far more elaborate than period-one limit cycles, including quasi-periodicity and chaos in hydrodynamically or thermoacoustically self-excited system. In this paper, the behaviour of a bluff-body stabilised turbulent premixed propane/air flame in a model jet-engine afterburner configuration is investigated using computational fluid dynamics. For the frequencies of interest in this investigation, an unsteady Reynolds-averaged Navier-Stokes approach is found to be appropriate. Combustion is represented using a modified laminar flamelet approach with an algebraic closure for the flame surface density. The results are validated by comparison with existing experimental data and with large eddy simulation, and the observed self-excited oscillations in pressure and heat release are studied using methods derived from dynamical systems theory. A systematic analysis is carried out by increasing the equivalence ratio of the reactant stream supplied to the premixed flame. A strong variation in the global flame structure is observed. The flame exhibits a self-excited hydrodynamic oscillation at low equivalence ratios, becomes steady as the equivalence ratio is increased to intermediate values, and again exhibits a self-excited thermoacoustic oscillation at higher equivalence ratios. Rich nonlinear behaviour is observed and the investigation demonstrates that turbulent premixed flames can exhibit complex dynamical behaviour including quasiperiodicity, limit cycles and period-two limit cycles due to the interactions of various

  10. Robust scalable stabilisability conditions for large-scale heterogeneous multi-agent systems with uncertain nonlinear interactions: towards a distributed computing architecture

    Science.gov (United States)

    Manfredi, Sabato

    2016-06-01

    Large-scale dynamic systems are becoming highly pervasive in their occurrence with applications ranging from system biology, environment monitoring, sensor networks, and power systems. They are characterised by high dimensionality, complexity, and uncertainty in the node dynamic/interactions that require more and more computational demanding methods for their analysis and control design, as well as the network size and node system/interaction complexity increase. Therefore, it is a challenging problem to find scalable computational method for distributed control design of large-scale networks. In this paper, we investigate the robust distributed stabilisation problem of large-scale nonlinear multi-agent systems (briefly MASs) composed of non-identical (heterogeneous) linear dynamical systems coupled by uncertain nonlinear time-varying interconnections. By employing Lyapunov stability theory and linear matrix inequality (LMI) technique, new conditions are given for the distributed control design of large-scale MASs that can be easily solved by the toolbox of MATLAB. The stabilisability of each node dynamic is a sufficient assumption to design a global stabilising distributed control. The proposed approach improves some of the existing LMI-based results on MAS by both overcoming their computational limits and extending the applicative scenario to large-scale nonlinear heterogeneous MASs. Additionally, the proposed LMI conditions are further reduced in terms of computational requirement in the case of weakly heterogeneous MASs, which is a common scenario in real application where the network nodes and links are affected by parameter uncertainties. One of the main advantages of the proposed approach is to allow to move from a centralised towards a distributed computing architecture so that the expensive computation workload spent to solve LMIs may be shared among processors located at the networked nodes, thus increasing the scalability of the approach than the network

  11. Microfluidic Fabrication of Hydrocortisone Nanocrystals Coated with Polymeric Stabilisers

    Directory of Open Access Journals (Sweden)

    David F. Odetade

    2016-12-01

    Full Text Available Hydrocortisone (HC nanocrystals intended for parenteral administration of HC were produced by anti-solvent crystallisation within coaxial assemblies of pulled borosilicate glass capillaries using either co-current flow of aqueous and organic phases or counter-current flow focusing. The organic phase was composed of 7 mg/mL of HC in a 60:40 (v/v mixture of ethanol and water and the anti-solvent was milli-Q water. The microfluidic mixers were fabricated with an orifice diameter of the inner capillary ranging from 50 µm to 400 µm and operated at the aqueous to organic phase flow rate ratio ranging from 5 to 25. The size of the nanocrystals decreased with increasing aqueous to organic flow rate ratio. The counter-current flow microfluidic mixers provided smaller nanocrystals than the co-current flow devices under the same conditions and for the same geometry, due to smaller diameter of the organic phase stream in the mixing zone. The Z-average particle size of the drug nanocrystals increased from 210–280 nm to 320–400 nm after coating the nanocrystals with 0.2 wt % aqueous solution of hydroxypropyl methylcellulose (HPMC in a stirred vial. The differential scanning calorimetry (DSC and X-ray powder diffraction (XRPD analyses carried out on the dried nanocrystals stabilized with HPMC, polyvinyl pyrrolidone (PVP, and sodium lauryl sulfate (SLS were investigated and reported. The degree of crystallinity for the processed sample was lowest for the sample stabilised with HPMC and the highest for the raw HC powder.

  12. In situ clinical evaluation of a stabilised, stannous fluoride dentifrice.

    Science.gov (United States)

    Bellamy, Philip G; Harris, Robin; Date, Robert F; Mussett, Andrew J S; Manley, Andrew; Manly, Andrew; Barker, Matthew L; Hellin, Nicola; West, Nicola X

    2014-03-01

    To compare the erosion protection efficacy of a stabilised, stannous fluoride (SnF2 ) dentifrice versus a sodium fluoride (NaF) dentifrice using a modified in situ clinical model. This study, a randomised parallel group in situ design with in vivo product use and ex vivo acid challenge, compared: A, a dentifrice containing 1,450 ppm F as NaF; B, a dentifrice containing 1,450 ppm F (1,100 ppm F as SnF2 + 350 ppm F as NaF); and T, tap water. Sample size was n = 4 per group (total of 12 subjects) and within each subject appliances were placed on each side of the mouth (left and right). Enamel specimens were placed in different positions of the mouth (front, mid-front, mid-rear, rear) in each appliance (total = 8 specimens per subject). Product treatment was twice per day (lingual brushing for 30 seconds followed by swishing for 90 seconds with the resultant product/saliva slurry) in vivo for 15 days, and ex vivo acid treatment (0.02 m citric acid 5 minutes four times per day; total exposure time = 300 minutes). Data were analysed using a general linear repeated measures model with treatment, side and position as fixed effects. Within subjects, correlations were modelled assuming a different correlation and variance for treatment B relative to the other groups. Pairwise treatment differences were performed using a 5% two-sided significance level. Enamel loss (in μm) was significantly lower (P dentifrice versus a conventional NaF dentifrice, validating the ability of the model to safely and effectively demonstrate differences in the erosion protection potential of oral care products. © 2014 FDI World Dental Federation.

  13. Decentralised robust stabilisation of uncertain large-scale interconnected time-delay systems with unknown upper bounds of uncertainties

    Science.gov (United States)

    Wu, Hansheng

    2016-09-01

    The problem of decentralised robust stabilisation is considered for a class of uncertain large-scale time-delay interconnected dynamical systems. In the paper, the upper bounds of delayed state perturbations, uncertainties, interconnection terms, and external disturbances are assumed to be completely unknown, and the delays are assumed to be any non-negative constants. For such a class of uncertain large-scale time-delay interconnected systems, a new method is presented whereby a class of adaptation-free decentralised local robust state feedback controllers can be constructed. In addition, it is also shown that the solutions of uncertain large-scale time-delay interconnected systems can be guaranteed to be uniformly ultimately bounded. Finally, as an application to the practical mechanical systems, some simulations of a numerical example are provided to demonstrate the validity of the theoretical results.

  14. Construction and accuracy assessment of patient-specific biocompatible drill template for cervical anterior transpedicular screw (ATPS insertion: an in vitro study.

    Directory of Open Access Journals (Sweden)

    Maoqing Fu

    Full Text Available BACKGROUND: With the properties of three-column fixation and anterior-approach-only procedure, anterior transpedicular screw (ATPS is ideal for severe multilevel traumatic cervical instabilities. However, the accurate insertion of ATPS remains challenging. Here we constructed a patient-specific biocompatible drill template and evaluated its accuracy in assisting ATPS insertion. METHODS: After ethical approval, 24 formalin-preserved cervical vertebrae (C2-C7 were CT scanned. 3D reconstruction models of cervical vertebra were obtained with 2-mm-diameter virtual pin tracts at the central pedicles. The 3D models were used for rapid prototyping (RP printing. A 2-mm-diameter Kirschner wire was then inserted into the pin tract of the RP model before polymethylmethacrylate was used to construct the patient-specific biocompatible drill template. After removal of the anterior soft tissue, a 2-mm-diameter Kirschner wire was inserted into the cervical pedicle with the assistance of drill template. Cadaveric cervical spines with pin tracts were subsequently scanned using the same CT scanner. A 3D reconstruction was performed of the scanned spines to get 3D models of the vertebrae containing the actual pin tracts. The deviations were calculated between 3D models with virtual and actual pin tracts at the middle point of the cervical pedicle. 3D models of 3.5 mm-diameter screws were used in simulated insertion to grade the screw positions. FINDINGS: The patient-specific biocompatible drill template was constructed to assist ATPS insertion successfully. There were no significant differences between medial/lateral deviations (P = 0.797 or between superior/inferior deviations (P = 0.741. The absolute deviation values were 0.82±0.75 mm and 1.10±0.96 mm in axial and sagittal planes, respectively. In the simulated insertion, the screws in non-critical position were 44/48 (91.7%. CONCLUSIONS: The patient-specific drill template is biocompatible, easy

  15. Bony healing of unstable thoracolumbar burst fractures in the elderly using percutaneously applied titanium mesh cages and a transpedicular fixation system with expandable screws.

    Directory of Open Access Journals (Sweden)

    Anica Eschler

    Full Text Available 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.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.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.Cementless fixation of osteoporotic burst fractures revealed substantial pain relief, adequate maintenance of reduction and a low complication rate. Bony healing after unstable osteoporotic burst

  16. CT morphometric analysis to determine the anatomical basis for the use of transpedicular screws during reconstruction and fixations of anterior cervical vertebrae.

    Directory of Open Access Journals (Sweden)

    Chun Chen

    Full Text Available BACKGROUND: Accurate placement of pedicle screw during Anterior Transpedicular Screw fixation (ATPS in cervical spine depends on accurate anatomical knowledge of the vertebrae. However, little is known of the morphometric characteristics of cervical vertebrae in Chinese population. METHODS: Three-dimensional reconstructions of CT images were performed for 80 cases. The anatomic data and screw fixation parameters for ATPS fixation were measured using the Mimics software. FINDINGS: The overall mean OPW, OPH and PAL ranged from 5.81 to 7.49 mm, 7.77 to 8.69 mm, and 33.40 to 31.13 mm separately, and SPA was 93.54 to 109.36 degrees from C3 to C6, 104.99 degrees at C7, whereas, 49.00 to 32.26 degrees from C4 to C7, 46.79 degrees at C3 (TPA. Dl/rSIP had an increasing trend away from upper endplate with mean value from 1.87 to 5.83 mm. Dl/rTIP was located at the lateral portion of the anterior cortex of vertebrae for C3 to C5 and ipsilateral for C6 to C7 with mean value from -2.70 to -3.00 mm, and 0.17 to 3.18 mm. The entrance points for pedicular screw insertion for C3 to C5 and C6 to C7 were recommended -2∼-3 mm and 0-4 mm from the median sagittal plane, respectively, 1-4 mm and 5-6 mm from the upper endplate, with TPA being 46.79-49.00 degrees and 40.89-32.26 degrees, respectively, and SPA being 93.54-106.69 degrees and 109.36-104.99 degrees, respectively. The pedicle screw insertion diameter was recommended 3.5 mm (C3 and C4, 4.0 mm (C5 to C7, and the pedicle axial length was 21-24 mm for C3 to C7 for both genders. However, the ATPS insertion in C3 should be individualized given its relatively small anatomical dimensions. CONCLUSIONS: The data provided a morphometric basis for the ATPS fixation technique in lower cervical fixation. It will help in preoperative planning and execution of this surgery.

  17. Stabilisation of health as the centre point of a health psychology of ageing.

    Science.gov (United States)

    Scholz, Urte; König, Claudia; Eicher, Stefanie; Martin, Mike

    2015-01-01

    Current health psychological theories and research mainly cover improvement of health, recovery from illness or maintenance of health. With this theoretical manuscript, we argue that in ageing societies in which chronic illness and multimorbidity become the norm rather than the exception, this focus of health psychology is no longer sufficient. Instead, in line with a recent conceptualisation of health as "the ability to adapt and to self-manage", we suggest that the centre point of a health psychology of ageing needs to be the stabilisation of health. Current theories of lifespan development, such as the model of selection, optimisation and compensation, the motivational theory of life span development, the two-process model of assimilative and accommodative coping and the recently introduced functional quality of life model are described with regard to their assumptions and related research focussing on stabilisation. All of these models explicitly comprise stabilisation as an important process of successful, healthy ageing. So far, however, the empirical research examining these models does not take stabilisation into account. Implications for research methods and practise of health stabilisation are discussed.

  18. SDP-based approximation of stabilising solutions for periodic matrix Riccati differential equations

    Science.gov (United States)

    Gusev, Sergei V.; Shiriaev, Anton S.; Freidovich, Leonid B.

    2016-07-01

    Numerically finding stabilising feedback control laws for linear systems of periodic differential equations is a nontrivial task with no known reliable solutions. The most successful method requires solving matrix differential Riccati equations with periodic coefficients. All previously proposed techniques for solving such equations involve numerical integration of unstable differential equations and consequently fail whenever the period is too large or the coefficients vary too much. Here, a new method for numerical computation of stabilising solutions for matrix differential Riccati equations with periodic coefficients is proposed. Our approach does not involve numerical solution of any differential equations. The approximation for a stabilising solution is found in the form of a trigonometric polynomial, matrix coefficients of which are found solving a specially constructed finite-dimensional semidefinite programming (SDP) problem. This problem is obtained using maximality property of the stabilising solution of the Riccati equation for the associated Riccati inequality and sampling technique. Our previously published numerical comparisons with other methods shows that for a class of problems only this technique provides a working solution. Asymptotic convergence of the computed approximations to the stabilising solution is proved below under the assumption that certain combinations of the key parameters are sufficiently large. Although the rate of convergence is not analysed, it appeared to be exponential in our numerical studies.

  19. A STUDY ON PROXIMAL HUMERAL FRACTURES STABILISED WITH PHILOS PLATE

    Directory of Open Access Journals (Sweden)

    Praveen Sivakumar K

    2017-02-01

    Full Text Available BACKGROUND Techniques for treating complex proximal humeral fractures vary and include fixations using tension bands, percutaneous pins, bone suture, T-plates, intramedullary nails, double tubular plates, hemiarthroplasty, plant tan humerus fixator plates, Polaris nails and blade plates. Complications of these techniques include cutout or back out of the screws and plates, avascular necrosis, nonunion, malunion, nail migration, rotator cuff impairment and impingement syndromes. Insufficient anchorage from conventional implants may lead to early loosening and failure, especially in osteoporotic bones. In general, nonoperative treatment of displaced three and four-part fractures of the proximal humerus leads to poor outcome due to intraarticular nature of injury and inherent instability of the fragments. Comminuted fractures of the proximal humerus are at risk of fixation failure, screw loosening and fracture displacement. Open reduction and internal fixation with conventional plate and screws has been associated with unacceptably high incidence of screw pull out. PHILOS (the proximal humeral internal locking system plate is an internal fixation system that enables angled stabilisation with multiple interlocking screws for fractures of the proximal humerus. MATERIALS AND METHODS 30 patients with proximal humerus fractures who were admitted in the Department of Orthopaedics, Government General Hospital, Kakinada, during the period November 2014 - November 2016 were taken up for study according to inclusion criteria. All patients were treated with PHILOS plate. These proximal humerus fractures were classified according to Neer’s classification. Patients were followed up at 6 weeks, 12 weeks and 6 months’ interval. Functional outcomes for pain, range of motion and muscle power and function were assessed using the Constant-Murley scoring system. Collected data analysed with independent t-test and ANNOVA test. RESULTS The outcome of the study was 1

  20. Polarographic study on the evolution of the diphenylamine as stabiliser of the solid propellants.

    Science.gov (United States)

    de Diego Martínez, A Pérez; Tascón, M L; Vázquez, M D; Sánchez Batanero, P

    2004-01-09

    Differential pulse polarography (DPP) and square wave voltammetry (SWV) were investigated, in order to know the stability of solid propellants which contain diphenylamine. The simultaneous determination of N-nitrousdiphenylamine (NnDPA), 2-nitrodiphenylamine (2nDPA), 4-nitrodiphenylamine (4nDPA) and 2,4-dinitrodiphenylamine (2,4dnDPA) by DPP and SWV was proposed due to these nitro-derivatives appear during the stabilisation process from degradation of diphenylamine (DPA) used as stabiliser in propellant compositions. The proposed methods were successfully applied to the simple base solid propellant (with nitrocellulose as the only active component), with its stabiliser DPA. In all cases and with both the techniques, detection limits propellants accurately, faster and cheaper than LC methods.

  1. Solidification/stabilisation of liquid oil waste in metakaolin-based geopolymer

    Science.gov (United States)

    Cantarel, V.; Nouaille, F.; Rooses, A.; Lambertin, D.; Poulesquen, A.; Frizon, F.

    2015-09-01

    The solidification/stabilisation of liquid oil waste in metakaolin based geopolymer was studied in the present work. The process consists of obtaining a stabilised emulsion of oil in a water-glass solution and then adding metakaolin to engage the setting of a geopolymer block with an oil emulsion stabilised in the material. Geopolymer/oil composites have been made with various oil fraction (7, 14 and 20 vol.%). The rigidity and the good mechanical properties have been demonstrated with compressive strength tests. Leaching tests evidenced the release of oil from the composite material is very limited whereas the constitutive components of the geopolymer (Na, Si and OH-) are involved into diffusion process.

  2. Discrete-time reservoir engineering with entangled bath and stabilising squeezed states

    Science.gov (United States)

    Miao, Zibo; Sarlette, Alain

    2017-09-01

    This theoretical proposal investigates how resonant interactions occurring when a harmonic oscillator is fed with a stream of entangled qubits allow us to stabilise squeezed states of the harmonic oscillator. We show that the properties of the squeezed state stabilised by this engineered reservoir, including the squeezing strength, can be tuned at will through the parameters of the ‘input’ qubits, albeit in tradeoff with the convergence rate. We also discuss the influence of the type of entanglement in the input from a pairwise case to a more widely distributed case. This paper can be read either as a proposal to stabilise squeezed states or as a step toward treating quantum systems with time-entangled reservoir inputs.

  3. Early Spin-Stabilised Rockets - the Rockets of Bergrat Heinrich Gottlob Kuhn

    Science.gov (United States)

    Fricke, H.-D.

    19th century's war rockets were at first stabilised by sticks, but these sticks produced a very uncertain flight path and it often happened that rockets changed their direction and even flew back to their firing position. So very many early inventors in Europe, America, and British-India tried to stabilise the rocket's flight in a better way. They tried fins and even rotation but they did not succeed. It is said in history that William Hale was the first who succeeded in constructing a spin stabilised (i.e. rotating) rocket which worked. But before him, in the thirties of that century, a German amateur rocket inventor succeeded as well and secretly proved his stickless rotating rockets in trials for Prussian officers and some years later officially for Saxon artillery officers. His invention was then bought by the kingdom of Saxony, but these were never use in the field because of lack of money.

  4. Effective solidification/stabilisation of mercury-contaminated wastes using zeolites and chemically bonded phosphate ceramics.

    Science.gov (United States)

    Zhang, Shaoqing; Zhang, Xinyan; Xiong, Ya; Wang, Guoping; Zheng, Na

    2015-02-01

    In this study, two kinds of zeolites materials (natural zeolite and thiol-functionalised zeolite) were added to the chemically bonded phosphate ceramic processes to treat mercury-contaminated wastes. Strong promotion effects of zeolites (natural zeolite and thiol-functionalised zeolite) on the stability of mercury in the wastes were obtained and these technologies showed promising advantages toward the traditional Portland cement process, i.e. using Portland cement as a solidification agent and natural or thiol-functionalised zeolite as a stabilisation agent. Not only is a high stabilisation efficiency (lowered the Toxicity Characteristic Leaching Procedure Hg by above 10%) obtained, but also a lower dosage of solidification (for thiol-functionalised zeolite as stabilisation agent, 0.5 g g(-1) and 0.7 g g(-1) for chemically bonded phosphate ceramic and Portland cement, respectively) and stabilisation agents (for natural zeolite as stabilisation agent, 0.35 g g(-1) and 0.4 g g(-1) for chemically bonded phosphate ceramic and Portland cement, respectively) were used compared with the Portland cement process. Treated by thiol-functionalised zeolite and chemically bonded phosphate ceramic under optimum parameters, the waste containing 1500 mg Hg kg(-1) passed the Toxicity Characteristic Leaching Procedure test. Moreover, stabilisation/solidification technology using natural zeolite and chemically bonded phosphate ceramic also passed the Toxicity Characteristic Leaching Procedure test (the mercury waste containing 625 mg Hg kg(-1)). Moreover, the presence of chloride and phosphate did not have a negative effect on the chemically bonded phosphate ceramic/thiol-functionalised zeolite treatment process; thus, showing potential for future application in treatment of 'difficult-to-manage' mercury-contaminated wastes or landfill disposal with high phosphate and chloride content.

  5. The direct Lyapunov method for the stabilisation of the Furuta pendulum

    Science.gov (United States)

    Aguilar-Ibañez, Carlos; Suárez-Castañón, Miguel S.; Gutiérres-Frias, Oscar O.

    2010-11-01

    A nonlinear controller for the stabilisation of the Furuta pendulum is presented. The control strategy is based on a partial feedback linearisation. In a first stage only the actuated coordinate of the Furuta pendulum is linearised. Then, the stabilising feedback controller is obtained by applying the Lyapunov direct method. That is, using this method we prove local asymptotic stability and demonstrate that the closed-loop system has a large region of attraction. The stability analysis is carried out by means of LaSalle's invariance principle. To assess the controller effectiveness, the results of the corresponding numerical simulations are presented.

  6. Novel use of hand fracture fixation plates in the surgical stabilisation of flail chest.

    LENUS (Irish Health Repository)

    Dunlop, Rebecca L E

    2010-01-01

    Plastic surgeons specialize in working closely with other surgical colleagues to help solve clinical problems. In this case, we performed surgical stabilisation of a large flail chest fragment in conjunction with the cardiothoracic surgical team, using the mini-plating set more commonly used for hand fracture fixation. The use of this fixation system for flail chest has not previously been described, but offers advantages over other reported methods, primarily by dispensing with the need for an extensive thoracotomy incision and by providing robust stabilisation without the presence of prominent hardware.

  7. Stabilisation for switched linear systems with time-varying delay and input saturation

    Science.gov (United States)

    Chen, Yonggang; Fei, Shumin; Zhang, Kanjian

    2014-03-01

    This article investigates the stabilisation problems for continuous-time and discrete-time switched systems with time-varying delay and saturated control input. Based on dwell time switching signals and multiple Lyapunov functional method, stabilisation conditions are well obtained in the context of linear matrix inequalities. To estimate attractive regions as large as possible, the feasibility problems are translated into optimisation problems. In addition, the corresponding results are presented for linear time-delay systems and switched delay-free systems, which improve and supplement some existing ones in the literature. Finally, numerical examples and simulations are given to illustrate the effectiveness and values of the proposed results.

  8. Noise-cancelled, cavity-enhanced saturation laser spectroscopy for laser frequency stabilisation

    Energy Technology Data Exchange (ETDEWEB)

    Vine, Glenn de; McClelland, David E; Gray, Malcolm B [Centre for Gravitational Physics, Faculty of Science, Australian National University, Canberra, ACT 0200 (Australia)

    2006-03-02

    We employ a relatively simple experimental technique enabling mechanical-noise free, cavityenhanced spectroscopic measurements of an atomic transition and its hyperfine structure. We demonstrate this technique with the 532 nm frequency doubled output from a Nd:YAG laser and an iodine vapour cell. The resulting cavity-enhanced, noise-cancelled, iodine hyperfine error signal is used as a frequency reference with which we stabilise the frequency of the 1064nm Nd:YAG laser. Preliminary frequency stabilisation results are then presented.

  9. Environmental Controls and Eco-geomorphic Interactions of the Barchan-to-parabolic Dune Stabilisation and the Parabolic-to-barchan Dune Reactivation

    Science.gov (United States)

    Yan, Na; Baas, Andreas

    2015-04-01

    Parabolic dunes are one of a few common aeolian landforms which are highly controlled by eco-geomorphic interactions. Parabolic dunes, on the one hand, can be developed from highly mobile dune landforms, barchans for instance, in an ameliorated vegetation condition; or on the other hand, they can be reactivated and transformed back into mobile dunes due to vegetation deterioration. The fundamental mechanisms and eco-geomorphic interactions controlling both dune transformations remain poorly understood. To bridge the gap between complex processes involved in dune transformations on a relatively long temporal scale and real world monitoring records on a very limited temporal scale, this research has extended the DECAL model to incorporate 'dynamic' growth functions and the different 'growth' of perennial shrubs between growing and non-growing seasons, informed by field measurements and remote sensing analysis, to explore environmental controls and eco-geomorphic interactions of both types of dune transformation. A non-dimensional 'dune stabilising index' is proposed to capture the interactions between environmental controls (i.e. the capabilities of vegetation to withstand wind erosion and sand burial, the sandy substratum thickness, the height of the initial dune, and the sand transport potential), and establish the linkage between these controls and the geometry of a stabilising dune. An example demonstrates how to use the power-law relationship between the dune stabilising index and the normalised migration distance to assist in extrapolating the historical trajectories of transforming dunes. The modelling results also show that a slight increase in vegetation cover of an initial parabolic dune can significantly increase the reactivation threshold of climatic impact (both drought stress and wind strength) required to reactivate a stabilising parabolic dune into a barchan. Four eco-geomorphic interaction zones that govern a barchan-to-parabolic dune transformation

  10. Nitrogen Transformations and Removal Mechanisms in Algal and Duckweed Waste Stabilisation Ponds

    NARCIS (Netherlands)

    Zimmo, O.

    2003-01-01

    Effective treatment of nitrogen containing wastewater is required to prevent eutrophication and groundwater pollution. This thesis shows that effective treatment may be combined with substantial nitrogen recovery in duckweed-based waste stabilisation ponds. In these ponds nitrogen is absorbed by rap

  11. Nitrogen Transformations and Removal Mechanisms in Algal and Duckweed Waste Stabilisation Ponds

    NARCIS (Netherlands)

    Zimmo, O.

    2003-01-01

    Effective treatment of nitrogen containing wastewater is required to prevent eutrophication and groundwater pollution. This thesis shows that effective treatment may be combined with substantial nitrogen recovery in duckweed-based waste stabilisation ponds. In these ponds nitrogen is absorbed by

  12. Stabilisation of the grain market by the flexible use of grain for bioethanol

    NARCIS (Netherlands)

    Helming, J.F.M.; Pronk, A.; Woltjer, I.

    2010-01-01

    This report reviews whether the grain market and grain price can be stabilised by the variation of the use of grain in the EU-27's production of bioethanol. The time horizon of this study is 2020, whereby account is taken of the minimum 10% obligation for biofuel use in the EU-27. An economic comput

  13. Experimental stabilisation of 2D vortex patterns using time-dependent forcing

    NARCIS (Netherlands)

    Lauret, M.; Kamp, L. P. J.; van Heijst, G. J. F.; M.R. de Baar,; Nijmeijer, H.

    2013-01-01

    Experimental results of the effect of time-periodic and “chirped” (electro-magnetic) forcing on vortex patterns in shallow-water-layer flows are presented. Analogously to vibrational control, the use of a time-periodic forcing results in stabilisation of otherwise unstable vortex patterns. Chirped f

  14. Arsenic and copper stabilisation in a contaminated soil by coal fly ash and green waste compost.

    Science.gov (United States)

    Tsang, Daniel C W; Yip, Alex C K; Olds, William E; Weber, Paul A

    2014-09-01

    In situ metal stabilisation by amendments has been demonstrated as an appealing low-cost remediation strategy for contaminated soil. This study investigated the short-term leaching behaviour and long-term stability of As and Cu in soil amended with coal fly ash and/or green waste compost. Locally abundant inorganic (limestone and bentonite) and carbonaceous (lignite) resources were also studied for comparison. Column leaching experiments revealed that coal fly ash outperformed limestone and bentonite amendments for As stabilisation. It also maintained the As stability under continuous leaching of acidic solution, which was potentially attributed to high-affinity adsorption, co-precipitation, and pozzolanic reaction of coal fly ash. However, Cu leaching in the column experiments could not be mitigated by any of these inorganic amendments, suggesting the need for co-addition of carbonaceous materials that provides strong chelation with oxygen-containing functional groups for Cu stabilisation. Green waste compost suppressed the Cu leaching more effectively than lignite due to the difference in chemical composition and dissolved organic matter. After 9-month soil incubation, coal fly ash was able to minimise the concentrations of As and Cu in the soil solution without the addition of carbonaceous materials. Nevertheless, leachability tests suggested that the provision of green waste compost and lignite augmented the simultaneous reduction of As and Cu leachability in a fairly aggressive leaching environment. These results highlight the importance of assessing stability and remobilisation of sequestered metals under varying environmental conditions for ensuring a plausible and enduring soil stabilisation.

  15. Autoignition and flame stabilisation processes in turbulent non-premixed hot coflow flames

    NARCIS (Netherlands)

    Oldenhof , E.

    2012-01-01

    This dissertation examines stabilisation processes in turbulent non-premixed jet flames, created by injecting gaseous fuel into a co-flowing stream of hot, low-oxygen combustion products. Being able to predict whether and how a flame achieves stable and reliable combustion is a matter of great pract

  16. Stabilisation of the grain market by the flexible use of grain for bioethanol

    NARCIS (Netherlands)

    Helming, J.F.M.; Pronk, A.; Woltjer, I.

    2010-01-01

    This report reviews whether the grain market and grain price can be stabilised by the variation of the use of grain in the EU-27's production of bioethanol. The time horizon of this study is 2020, whereby account is taken of the minimum 10% obligation for biofuel use in the EU-27. An economic

  17. Increased muscle activity to stabilise mobile bearing knees in patients with rheumatoid arthritis

    NARCIS (Netherlands)

    Garling, E.H.; Eck, M; Wedding, T.; Veeger, H.E.J.; Valstar, E.R.; Nelissen, R.G.H.H.

    2005-01-01

    The aim of this study was to assess the differences in muscle activity (surface EMG) between a posterior stabilised (PS) total knee design and a mobile bearing (MB) posterior cruciate ligament retaining design in rheumatoid arthritis (RA) patients during a step-up task. Four patients with a PS total

  18. Measurement of wind profiles by motion-stabilised ship-borne Doppler lidar

    Directory of Open Access Journals (Sweden)

    P. Achtert

    2015-09-01

    Full Text Available Three months of Doppler lidar wind measurements were obtained during the Arctic Cloud Summer Experiment on the icebreaker Oden during the summer of 2014. Such ship-borne measurements require active stabilisation to remove the effects of ship motion. We demonstrate that the combination of a commercial Doppler lidar with a custom-made motion-stabilisation platform enables the retrieval of wind profiles in the Arctic boundary layer during both cruising and ice-breaking with statistical uncertainties comparable to land-based measurements. This holds particularly within the planetary boundary layer even though the overall aerosol load was very low. Motion stabilisation was successful for high wind speeds in open water and the resulting wave conditions. It allows for the retrieval of winds with a random error below 0.2 m s−1, comparable to the measurement error of standard radiosondes. The combination of a motion-stabilised platform with a low-maintenance autonomous Doppler lidar has the potential to enable continuous long-term high-resolution ship-based wind profile measurements over the oceans.

  19. Measurement of wind profiles by motion-stabilised ship-borne Doppler lidar

    Science.gov (United States)

    Achtert, P.; Brooks, I. M.; Brooks, B. J.; Moat, B. I.; Prytherch, J.; Persson, P. O. G.; Tjernström, M.

    2015-11-01

    Three months of Doppler lidar wind measurements were obtained during the Arctic Cloud Summer Experiment on the icebreaker Oden during the summer of 2014. Such ship-borne Doppler measurements require active stabilisation to remove the effects of ship motion. We demonstrate that the combination of a commercial Doppler lidar with a custom-made motion-stabilisation platform enables the retrieval of wind profiles in the Arctic atmospheric boundary layer during both cruising and ice-breaking with statistical uncertainties comparable to land-based measurements. This held true particularly within the atmospheric boundary layer even though the overall aerosol load was very low. Motion stabilisation was successful for high wind speeds in open water and the resulting wave conditions. It allows for the retrieval of vertical winds with a random error below 0.2 m s-1. The comparison of lidar-measured wind and radio soundings gives a mean bias of 0.3 m s-1 (2°) and a mean standard deviation of 1.1 m s-1 (12°) for wind speed (wind direction). The agreement for wind direction degrades with height. The combination of a motion-stabilised platform with a low-maintenance autonomous Doppler lidar has the potential to enable continuous long-term high-resolution ship-based wind profile measurements over the oceans.

  20. Magnetron sputtering system stabilisation for high rate desposition of AlN films

    DEFF Research Database (Denmark)

    Fomin, A; Akhmatov, Vladislav; Selishchev, S

    1998-01-01

    The stabilisation of a planar magnetron sputtering system for reactive sputtering of AlN in a gaseous mixture of Ar and highly active NH3 was examined. The helical instability in the cathode plasma sheath was observed and methods for its damping were proposed. It was found that the deposition of c...

  1. Feedback stabilisation of a two-dimensional pool-boiling system by modal control

    NARCIS (Netherlands)

    van Gils, R.W.; Speetjens, M.F.M; Zwart, Heiko J.; Nijmeijer, H.

    The present study concerns the feedback stabilisation of the unstable equilibria of a two-dimensional nonlinear pool-boiling system with essentially heterogeneous temperature distributions in the fluid-heater interface. Regulation of such equilibria has great potential for application in, for

  2. Food-grade Pickering stabilisation of foams by in situ hydrophobisation of calcium carbonate particles

    NARCIS (Netherlands)

    Binks, Bernard P.; Muijlwijk, K.; Koman, Henriëtte; Poortinga, A.T.

    2017-01-01

    The aim of this study was to investigate the possibility of stabilising foam bubbles in water by adsorption of calcium carbonate (CaCO3) particles. Because CaCO3 is hydrophilic and not surface-active, particles were hydrophobised in situ with several emulsifiers. The used emulsifiers were food-grade

  3. Oral N-acetylcysteine administration does not stabilise the process of established severe preeclampsia.

    NARCIS (Netherlands)

    Roes, E.M.; Raijmakers, M.; Boo, T.M. de; Zusterzeel, P.L.M.; Merkus, H.M.; Peters, W.H.M.; Steegers, E.A.P.

    2006-01-01

    OBJECTIVE: To stabilise the disease process in women with early onset severe preeclampsia and/or HELLP syndrome by enhancing maternal antioxidants effects of glutathione. STUDY DESIGN: In a randomised, double-blind, placebo-controlled trial, women with severe preeclampsia and/or HELLP syndrome

  4. Chemical Stablilisation of Sand : Part VIII Furan Resins as Dune and Coastal Sand Stabiliser

    Directory of Open Access Journals (Sweden)

    Ram Gopal

    1990-04-01

    Full Text Available Studies on furan resin as dune sand stabiliser are presented. Influence of acid catalysts, viz. phenol disulphonic acid, sulphuric acid, hydrochloric acid and phosphoric acid and other catalysts, viz. trichlorotoluene and benzoyl chloride along with promoters, zinc chloride and ferric chloride, on the strength of stabilised furan resin-sand specimens has been discussed. Optimisation studies on resin content, catalysts and promoters and curing conditions have revealed that maximum strength of 260 kg/cm/sup 2/ of the standard specimens made by compaction of coastal sand using furan resins (10 per cent, sulphuric acid (9N, 30 per cent and a curing time of 2 hr at 40 degree Centigrade is higher than the 170 kg/cm/sup 2/ of specimens made of Rajasthan desert sand. Sandy patches stabilised by seepage technique recorded a maximum strength of 125 kg/cm/sup 2/. Physico-chemical characteristics of this system and effect of environment on stabilised specimens have also been studied and field trials conducted successfully. This resin-catalyst system would be extremely useful in humid and saline field (coastal areas for different military applications.

  5. Measurement of wind profiles by motion-stabilised ship-borne Doppler lidar

    Directory of Open Access Journals (Sweden)

    P. Achtert

    2015-11-01

    Full Text Available Three months of Doppler lidar wind measurements were obtained during the Arctic Cloud Summer Experiment on the icebreaker Oden during the summer of 2014. Such ship-borne Doppler measurements require active stabilisation to remove the effects of ship motion. We demonstrate that the combination of a commercial Doppler lidar with a custom-made motion-stabilisation platform enables the retrieval of wind profiles in the Arctic atmospheric boundary layer during both cruising and ice-breaking with statistical uncertainties comparable to land-based measurements. This held true particularly within the atmospheric boundary layer even though the overall aerosol load was very low. Motion stabilisation was successful for high wind speeds in open water and the resulting wave conditions. It allows for the retrieval of vertical winds with a random error below 0.2 m s−1. The comparison of lidar-measured wind and radio soundings gives a mean bias of 0.3 m s−1 (2° and a mean standard deviation of 1.1 m s−1 (12° for wind speed (wind direction. The agreement for wind direction degrades with height. The combination of a motion-stabilised platform with a low-maintenance autonomous Doppler lidar has the potential to enable continuous long-term high-resolution ship-based wind profile measurements over the oceans.

  6. Stabilisation of amorphous furosemide increases the oral drug bioavailability in rats

    DEFF Research Database (Denmark)

    Nielsen, Line Hagner; Rades, Thomas; Müllertz, Anette

    2015-01-01

    A glass solution of the amorphous sodium salt of furosemide (ASSF) and polyvinylpyrrolidone (PVP) (80: 20 w/w%) was prepared by spray drying. It was investigated if PVP was able to stabilise ASSF during storage and dissolution and whether this influenced the in vivo performance of the glass solut...

  7. Towards a General Understanding of Carbonyl-Stabilised Ammonium Ylide-Mediated Epoxidation Reactions.

    Science.gov (United States)

    Novacek, Johanna; Roiser, Lukas; Zielke, Katharina; Robiette, Raphaël; Waser, Mario

    2016-08-01

    The key factors for carbonyl-stabilised ammonium ylide-mediated epoxidation reactions were systematically investigated by experimental and computational means and the hereby obtained energy profiles provide explanations for the observed experimental results. In addition, we were able to identify the first tertiary amine-based chiral auxiliary that allows for high enantioselectivities and high yields for such epoxidation reactions.

  8. A numerical procedure to compute the stabilising solution of game theoretic Riccati equations of stochastic control

    Science.gov (United States)

    Dragan, Vasile; Ivanov, Ivan

    2011-04-01

    In this article, the problem of the numerical computation of the stabilising solution of the game theoretic algebraic Riccati equation is investigated. The Riccati equation under consideration occurs in connection with the solution of the H ∞ control problem for a class of stochastic systems affected by state-dependent and control-dependent white noise and subjected to Markovian jumping. The stabilising solution of the considered game theoretic Riccati equation is obtained as a limit of a sequence of approximations constructed based on stabilising solutions of a sequence of algebraic Riccati equations of stochastic control with definite sign of the quadratic part. The proposed algorithm extends to this general framework the method proposed in Lanzon, Feng, Anderson, and Rotkowitz (Lanzon, A., Feng, Y., Anderson, B.D.O., and Rotkowitz, M. (2008), 'Computing the Positive Stabilizing Solution to Algebraic Riccati Equations with an Indefinite Quadratic Term Viaa Recursive Method,' IEEE Transactions on Automatic Control, 53, pp. 2280-2291). In the proof of the convergence of the proposed algorithm different concepts associated the generalised Lyapunov operators as stability, stabilisability and detectability are widely involved. The efficiency of the proposed algorithm is demonstrated by several numerical experiments.

  9. Structural and electrical characterisation of silica-containing yttria-stabilised zirconia

    DEFF Research Database (Denmark)

    Appel, Charlotte Clausen; Bonanos, Nikolaos

    1999-01-01

    grain boundary impedance. The present study examines the effect of SiO2 and SiO2 with Mn-oxide on the structure and resistivity of yttria stabilised zirconia electrolyte materials. During fabrication of Solid Oxide Fuel Cells, Mn readily diffuses from the manganite-based cathode into the electrolyte...

  10. Towards 12% stabilised efficiency in single junction polymorphous silicon solar cells: experimental developments and model predictions

    Directory of Open Access Journals (Sweden)

    Abolmasov Sergey

    2016-01-01

    Full Text Available We have combined recent experimental developments in our laboratory with modelling to devise ways of maximising the stabilised efficiency of hydrogenated amorphous silicon (a-Si:H PIN solar cells. The cells were fabricated using the conventional plasma enhanced chemical vapour deposition (PECVD technique at various temperatures, pressures and gas flow ratios. A detailed electrical-optical simulator was used to examine the effect of using wide band gap P-and N-doped μc-SiOx:H layers, as well as a MgF2 anti-reflection coating (ARC on cell performance. We find that with the best quality a-Si:H so far produced in our laboratory and optimised deposition parameters for the corresponding solar cell, we could not attain a 10% stabilised efficiency due to the high stabilised defect density of a-Si:H, although this landmark has been achieved in some laboratories. On the other hand, a close cousin of a-Si:H, hydrogenated polymorphous silicon (pm-Si:H, a nano-structured silicon thin film produced by PECVD under conditions close to powder formation, has been developed in our laboratory. This material has been shown to have a lower initial and stabilised defect density as well as higher hole mobility than a-Si:H. Modelling indicates that it is possible to attain stabilised efficiencies of 12% when pm-Si:H is incorporated in a solar cell, deposited in a NIP configuration to reduce the P/I interface defects and combined with P- and N-doped μc-SiOx:H layers and a MgF2 ARC.

  11. Towards 12% stabilised efficiency in single junction polymorphous silicon solar cells: experimental developments and model predictions

    Science.gov (United States)

    Abolmasov, Sergey; Cabarrocas, Pere Roca i.; Chatterjee, Parsathi

    2016-01-01

    We have combined recent experimental developments in our laboratory with modelling to devise ways of maximising the stabilised efficiency of hydrogenated amorphous silicon (a-Si:H) PIN solar cells. The cells were fabricated using the conventional plasma enhanced chemical vapour deposition (PECVD) technique at various temperatures, pressures and gas flow ratios. A detailed electrical-optical simulator was used to examine the effect of using wide band gap P-and N-doped μc-SiOx:H layers, as well as a MgF2 anti-reflection coating (ARC) on cell performance. We find that with the best quality a-Si:H so far produced in our laboratory and optimised deposition parameters for the corresponding solar cell, we could not attain a 10% stabilised efficiency due to the high stabilised defect density of a-Si:H, although this landmark has been achieved in some laboratories. On the other hand, a close cousin of a-Si:H, hydrogenated polymorphous silicon (pm-Si:H), a nano-structured silicon thin film produced by PECVD under conditions close to powder formation, has been developed in our laboratory. This material has been shown to have a lower initial and stabilised defect density as well as higher hole mobility than a-Si:H. Modelling indicates that it is possible to attain stabilised efficiencies of 12% when pm-Si:H is incorporated in a solar cell, deposited in a NIP configuration to reduce the P/I interface defects and combined with P- and N-doped μc-SiOx:H layers and a MgF2 ARC.

  12. POSTERIOR STABILISATION OF BURST FRACTURES OF DORSOLUMBAR SPINE

    Directory of Open Access Journals (Sweden)

    Mukharjee

    2016-05-01

    admission. Postoperatively, 4 patients remained in grade A, 5 patients had grade C, 6 patients had grade D and 10 had grade E. All the patients had neurogenic bladder at the time of admission, nine remained neurogenic post-operatively and 16 patients attained normal bladder status. Pain showed an average of 4.73 pre-operative value and an average post-operative value of 1.13 on VAS scale. Radiologically, the mean pre-operative Cobb’s angle was 14.26 degrees and post- operative mean was 3.63 degrees. The mean improvement in Cobb’s angle was 10.63 degrees. The mean vertebral body compression (height ratio was 60.83 and mean post-operative ratio was 81.66. Improvement was a mean 20.83 in VBHR post operatively justifying the procedure. The mean preoperative sagittal index was 20.43 degrees and mean postoperative sagittal index was 14.6 degrees. Functional outcome was assessed by Spinal Cord Independence Measure score. The mean pre and post-operative scores were 32.26 and 81.53 respectively. Mean improvement in SCIM score was 49.27. This was done at three weekly intervals up to 31 weeks from admission. Bed sores occurred in 5 patients, 8 patients developed UTI, two patients developed upper respiratory infection and two suffered fever in the post-operative period. CONCLUSION Incidence of thoracolumbar spine fractures has a single peak in young adult age group irrespective of the sex of the patient. Incidence is higher in males with almost equal distribution in rural and urban areas. Unlike western hemisphere, the major cause of thoracolumbar spine fracture is fall from height (not the road traffic accidents. Incidence of thoracolumbar spine has got significant relation to the patient’s occupation, especially people working as tree climbers, construction workers. Most common level of fracture of thoracolumbar spine is thoracolumbar junction (T12-L1. Surgical stabilisation of unstable thoracolumbar spine fractures with short segment posterior spinal instrumentation with

  13. The use of muscle dynamometer for correction of muscle imbalances in the area of deep stabilising spine system.

    Science.gov (United States)

    Malátová, Renata; Rokytová, Jitka; Stumbauer, Jan

    2013-08-01

    Dorsal pain caused by spine dysfunctions belongs to most frequent chronic illnesses. The muscles of the deep stabilising spine system work as a single functional unit where a dysfunction of only one muscle causes dysfunction of the whole system. Non-invasive, objective and statistically measurable evaluation of the condition of deep stabilising spine system has been made possible by the construction of muscular dynamometer. The aim of our work has been the assessment of deep stabilising spine system by diaphragm test and muscular dynamometer measurements. Based on an initial examination, a 6-week intervention programme was established including instructions on physiological body posture and correct basic body stabilisation for the given exercises and muscle strengthening. Consecutive measurements are then compared with the initial ones. It was presumed that a smaller number of the tested subjects would be able to correctly activate the deep stabilising spine system muscles before the intervention programme when compared to those after the intervention programme. A positive change of 87% has been found. It is clear that if a person actively approaches the programme, then positive adaptation changes on the deep stabilising spine system are seen only after 6 weeks. With the muscular dynamometer, activation of deep stabilising spine system can be objectively measured. Changes between the initial condition of a subject and the difference after some exercise or rehabilitation are especially noticeable. Also, the effect of given therapy or correct performance of the exercise can be followed and observed.

  14. EMDR versus stabilisation in traumatised asylum seekers and refugees: results of a pilot study

    Directory of Open Access Journals (Sweden)

    Rolf J. Kleber

    2011-08-01

    Full Text Available Traumatised asylum seekers and refugees are clinically considered a complex population. Discussion exists on whether with this population treatment guidelines for post-traumatic stress disorder (PTSD should be followed and Trauma-Focused Cognitive-Behavioural Therapy (TF-CBT or Eye Movement Desensitisation and Reprocessing (EMDR should be applied, or whether a phased model starting with stabilisation is preferable. Some clinicians fear that trauma-focused interventions may lead to unmanageable distress or may be ineffective. While cognitive-behavioural interventions have been found to be effective with traumatised refugees, no studies concerning the efficacy of EMDR with this population have been conducted as yet.In preparation for a randomised trial comparing EMDR and stabilisation with traumatised refugees, a pilot study with 20 participants was conducted. The objective was to examine feasibility of participation in a randomised trial for this complex population and to examine acceptability and preliminary efficacy of EMDR.Participants were randomly allocated to 11 sessions of either EMDR or stabilisation. Symptoms of PTSD (SCID-I, HTQ, depression and anxiety (HSCL-25, and quality of life (WHOQOL-BREF were assessed at pre- and post-treatment and 3-month follow-up.Participation of traumatised refugees in the study was found feasible, although issues associated with complex traumatisation led to a high pre-treatment attrition and challenges in assessments. Acceptability of EMDR was found equal to that of stabilisation with a high drop-out for both conditions. No participants dropped out of the EMDR condition because of unmanageable distress. While improvement for EMDR participants was small, EMDR was found to be no less efficacious than stabilisation. Different symptom courses between the two conditions, with EMDR showing some improvement and stabilisation showing some deterioration between pre-treatment and post-treatment, justify the conduct

  15. Transpedicular screw fixation system for treatment of unstable fractures of arias vertebra%经后路单纯寰椎椎弓根螺钉内固定治疗不稳定性寰椎骨折

    Institute of Scientific and Technical Information of China (English)

    马维虎; 许楠健; 徐荣明; 赵刘军; 蒋伟宇; 孙韶华; 胡勇; 刘观燚; 顾勇杰

    2011-01-01

    目的 探讨经后路单纯寰椎椎弓根螺钉内固定治疗不稳定性寰椎骨折的临床疗效.方法 2007年3月~2010年4月,采用经后路寰椎椎弓根螺钉内固定治疗不稳定性寰椎骨折患者23例,其中8例为后3/4 Jefferson骨折;12例患者为半环Jefferson骨折;3例患者为后1/2 Jefferson骨折.患者均有不同程度的颈枕区疼痛,活动受限;日本骨科协会(Japanese Orthopaedic Association,JOA)评分为7~12分,平均9.5分.结果 所有患者随访12~39个月,平均18.8个月.手术时间为30~60 min,出血量为50~200 mL.术后X 线片及CT 示1例一侧寰椎椎弓根螺钉部分进入椎动脉孔,1例螺钉一侧偏内致椎弓根内侧皮质破裂,但均无神经症状,其余螺钉位置良好.术后JOA评分13~17分,平均14.7分.未发生与螺钉相关的神经血管并发症,无内固定松动或断钉现象,所有患者术后随访时均已达到骨性融合,寰枢关节旋转功能良好.结论 寰椎后路椎弓根螺钉技术是治疗不稳定性寰椎骨折的有效方法.%Objective To study the clinical outcomes of transpedicular screw fixation system for treatment of unstable fractures of the atlas vertebra. Methods From March 2007 to April 2010, transpedicular fixation was employed to treat 23 patients with unstable fractures of the atlas vertebra; the patients included l5 males and 8 females. Eight patients had posterior 3/4 Jefferson fracture, 12 had 1/2 ring Jefferson fracture and 3 had posterior 1/2 Jefferson fracture. The preoperative Japanese Orthopaedic Association(JOA) score was 7-12, with an average of 9.5. All patients were treated by single transpedicular fixation via the posterior approach. Results The patients were followed up for 12-39 months, with a mean of 18.8 months. The operative time ranged 30-60 min. Intraoperative blood loss ranged from 50-200 mL. Postoperative roentgenoghaph and CT scan showed that 1 screw was inserted so medially and penetrated the spinal canal, and 1

  16. C2~3椎弓根-侧块螺钉系统治疗不稳定型Hangman骨折%Transpedicular with Pedicle Screw Fixation for the Treatment of Hangman's Fractures

    Institute of Scientific and Technical Information of China (English)

    王磊; 刘海龙; 徐卫松; 仇志学; 韩国栋

    2011-01-01

    目的 探讨C2~3椎弓根-侧块螺钉系统治疗Hangman骨折的疗效及临床效果.方法 我院2007年4月至2010年10月收治的11例Hangman骨折患者进行回顾性研究,男4例,女7例;年龄22~61岁,平均42.5岁.患者均表现为颈痛、颈部活动受限,2例单侧上肢,1例双侧上肢麻木无力.所有患者入院后均行X线、三维CT及MRI检查,并测量Cz~3椎体移位和成角,其中Levine- Edwards分型,Ⅰ型3例,Ⅰ型4例,Ⅰa型2倒,Ⅲ型2例.人院后常规行颅骨牵引,Ⅰ型患者予以halo-vest架外固定治疗,Ⅱ型、Ⅱa型、Ⅲ型患者行后路C2~3椎弓根侧块螺钉内固定术,术后用费城颈托保护6周.结果 随访2~44个月,平均20.6个月.平均6个月时骨折端愈合,颈痛、肢体麻木等症状消失,但颈部活动度较正常略有下降,无内固定失败及感染等并发症发生.结论 经后路C2~3椎弓根侧块螺钉系统是治疗Hangman骨折的良好手术方式.%Objective To determine the treatment efficacy of transpedicular with pedicle screw fixation for the treatment of Hangman's fracture. Methods A retrospective review of 11 cases,including 4 males and 7 females,with Hangman's fractures was performed. The age of the patients were 22~61 years, average 42. 5 years. All the patients complained neck pain and limitation of movement of the neck. Numbness and weakness appeard in unilateral upper limb in 2 cases, biliater upper limbs in 1 case. All patients received anterior-posterior and lateral X-rays,MRI andthree dimensional CT scans. Initial and final radiographs were measured for translation and angilation of C2~J. According to the Levine-Edwards classification,there were 3 cases for type I ,4 for type H ,2 for type JI a and 2 for type I . Skull tractions under extension position were used in all patients after admission. Halo-vest treatment option for type Ⅰ ,Then type Ⅱ ,Ⅱla, Ⅲ transpedicular with pedicle screw fixation were performed. Philadelphia collars

  17. A Scott bench with ergonomic thorax stabilisation pad improves body posture during preacher arm curl exercise.

    Science.gov (United States)

    Biscarini, Andrea; Benvenuti, Paolo; Busti, Daniele; Zanuso, Silvano

    2016-05-01

    We assessed whether the use of an ergonomic thorax stabilisation pad, during the preacher arm curl exercise, could significantly reduce the excessive shoulder protraction and thoracic kyphosis induced by the standard flat pad built into the existing preacher arm curl equipment. A 3D motion capture system and inclinometers were used to measure shoulder protraction and thoracic kyphosis in 15 subjects performing preacher arm curl with a plate-loaded machine provided with the standard flat pad. The same measures were repeated after replacing the flat pad with a new ergonomic pad, specifically designed to accommodate the thorax profile and improve body posture. Pad replacement significantly (p thorax stabilisation pad for the preacher arm curl exercise. The new ergonomic pad improves the poor posture conditions induced by the standard flat pad and may potentially allow a more effective training, prevent musculoskeletal discomfort, improve the breathing function and reduce the risk of injury.

  18. The streamline upwind Petrov-Galerkin stabilising method for the numerical solution of highly advective problems

    Directory of Open Access Journals (Sweden)

    Carlos Humberto Galeano Urueña

    2010-05-01

    Full Text Available This article describes the streamline upwind Petrov-Galerkin (SUPG method as being a stabilisation technique for resolving the diffusion-advection-reaction equation by finite elements. The first part of this article has a short analysis of the importance of this type of differential equation in modelling physical phenomena in multiple fields. A one-dimensional description of the SUPG me- thod is then given to extend this basis to two and three dimensions. The outcome of a strongly advective and a high numerical complexity experiment is presented. The results show how the version of the implemented SUPG technique allowed stabilised approaches in space, even for high Peclet numbers. Additional graphs of the numerical experiments presented here can be downloaded from www.gnum.unal.edu.co.

  19. Vibration-displacement measurements with a highly stabilised optical fiber Michelson interferometer system

    Science.gov (United States)

    Xie, Fang; Ren, Junyu; Chen, Zhimin; Feng, Qibo

    2010-02-01

    A highly stabilised vibration-displacement measurement system, which employs fiber Bragg gratings (FBGs) to interleave two fiber Michelson interferometers that share the common-interferometric-optical path, is presented. The phase change in the interferometric signals of the two fiber Michelson interferometers have been tracked, respectively, with two electronic feedback loops. One of the fiber interferometers is used to stabilise the system by the use of an electronic feedback loop to compensate the environmental disturbances. The second fiber interferometer is used to perform the measurement task and employs another electronic feedback loop to track the phase change in the interferometric signal. The measurement system is able to measure vibration-displacement and provide the sense of direction of the displacement. The frequency range of the measured vibration-displacement is from 0.1 to 200 Hz and the measurement resolution is 10 nm.

  20. Green synthesis of highly concentrated aqueous colloidal solutions of large starch-stabilised silver nanoplatelets.

    Science.gov (United States)

    Cheng, Fei; Betts, Jonathan W; Kelly, Stephen M; Hector, Andrew L

    2015-01-01

    A simple, environmentally friendly and cost-effective method has been developed to prepare a range of aqueous silver colloidal solutions, using ascorbic acid as a reducing agent, water-soluble starch as a combined crystallising, stabilising and solubilising agent, and water as the solvent. The diameter of silver nanoplatelets increases with higher concentrations of AgNO3 and starch. The silver nanoparticles are also more uniform in shape the greater the diameter of the nanoparticles. Colloidal solutions with a very high concentration of large, flat, hexagonal silver nanoplatelets (~230 nm in breadth) have been used to deposit and fix an antibacterial coating of these large starch-stabilised silver nanoplates on commercial cotton fibres, using a simple dip-coating process using water as the solvent, in order to study the dependence of the antibacterial properties of these nanoplatelets on their size.

  1. Femtosecond fibre laser stabilisation to an optical frequency standard using a KTP electro-optic crystal

    Energy Technology Data Exchange (ETDEWEB)

    Nyushkov, B N [Novosibirsk State University, Novosibirsk (Russian Federation); Pivtsov, V S; Koliada, N A [Institute of Laser Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation); Kaplun, A B; Meshalkin, A B [S.S. Kutateladze Institute of Heat Physics, Siberian Division of the Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2015-05-31

    A miniature intracavity KTP-based electro-optic phase modulator has been developed which can be used for effective stabilisation of an optical frequency comb of a femtosecond erbiumdoped fibre laser to an optical frequency standard. The use of such an electro-optic modulator (EOM) has made it possible to extend the working frequency band of a phase-locked loop system for laser stabilisation to several hundred kilohertz. We demonstrate that the KTP-based EOM is sufficiently sensitive even at a small optical length, which allows it to be readily integrated into cavities of femtosecond fibre lasers with high mode frequency spacings (over 100 MHz). (extreme light fields and their applications)

  2. P-Stereogenic Phosphines for the Stabilisation of Metal Nanoparticles. A Surface State Study

    Directory of Open Access Journals (Sweden)

    Eva Raluy

    2016-12-01

    Full Text Available Palladium and ruthenium nanoparticles have been prepared following the organometallic precursor decomposition methodology, under dihydrogen pressure and in the presence of borane protected P-stereogenic phosphines. NMR (Nuclear Magnetic Resonance monitoring of the corresponding syntheses has permitted to determine the optimal metal/ligand ratio for leading to small and well-dispersed nanoparticles. Exchange ligand reactions of the as-prepared materials have proven the strong interaction of the phosphines with the metal surface; only oxidative treatment using hydrogen peroxide could release the phosphine-based stabiliser from the metal surface. Pd and Ru nanoparticles have been evaluated in hydrogenation reactions, confirming the robustness of the stabilisers, which selectively permitted the hydrogenation of exocyclic C=C bonds, preventing the coordination of the aromatic rings and as a result, their hydrogenation.

  3. Preconditioning of Nonlinear Mixed Effects Models for Stabilisation of Variance-Covariance Matrix Computations.

    Science.gov (United States)

    Aoki, Yasunori; Nordgren, Rikard; Hooker, Andrew C

    2016-03-01

    As the importance of pharmacometric analysis increases, more and more complex mathematical models are introduced and computational error resulting from computational instability starts to become a bottleneck in the analysis. We propose a preconditioning method for non-linear mixed effects models used in pharmacometric analyses to stabilise the computation of the variance-covariance matrix. Roughly speaking, the method reparameterises the model with a linear combination of the original model parameters so that the Hessian matrix of the likelihood of the reparameterised model becomes close to an identity matrix. This approach will reduce the influence of computational error, for example rounding error, to the final computational result. We present numerical experiments demonstrating that the stabilisation of the computation using the proposed method can recover failed variance-covariance matrix computations, and reveal non-identifiability of the model parameters.

  4. The influence of preliminary aerobic treatment on the efficacy of waste stabilisation under leachate recirculation conditions

    Directory of Open Access Journals (Sweden)

    Monika Suchowska-Kisielewicz

    2014-12-01

    Full Text Available This article presents the changes in the chemical composition of leachate and the concentrations and quantity of methane production in each individual decomposition phases, determined for untreated and after aerobic treatment of waste stabilised in anaerobic reactors with and without leachate recirculation. The research results demonstrate that leachate recirculation intensifies the decomposition of both aerobically treated and untreated waste. The methane production in the reactor with untreated, stabilised waste with recirculation was 28% higher; and in the reactor with aerobically treated waste, the methane production was 24% higher than in the reactors without recirculation. An important finding of the study is that aerobic treatment of waste prior to landfilling effectively reduces the quantity of pollutant emissions in leachate and biogas from waste and increases the availability for methane micro-organisms of organic substrates from difficult-to-decompose organic substances.

  5. Process stabilisation - key assumption for implementation of Industry 4.0 concept in industrial company

    Directory of Open Access Journals (Sweden)

    Felicita Chromjakova

    2017-01-01

    Full Text Available Implementation of Industry 4.0 concept based on the real stability of horizontal (business and vertical (digitized enterprise processes. Special attention will be given in this paper to the process stabilisation model including their core pillars, next to the identification of basic metric for evaluation of process model stability. Results presented in this paper based on the research project and survey realised in more industrial companies.

  6. Nitrogen transformations and removal mechanisms in algal and duckweed stabilisation ponds

    OpenAIRE

    Zimmo, O.

    2003-01-01

    This thesis describes the results of a comparative study of the performance of algae-based ponds (ABPs) and duckweed-based ponds (DBPs) for wastewater treatment, with emphasis on nitrogen transformations and removal mechanisms.Batch experiments simulating algae and duckweed ( Lemna gibba ) stabilisation ponds for domestic wastewater treatment were conducted to quantify the importance of various nitrogen removal mechanisms under controlled conditions of pH and DO. N-removal in both systems by ...

  7. Scientific and methodical approach to identifying lags of the stabilisation financial policy

    OpenAIRE

    Savchenko Kostyantyn V.

    2013-01-01

    The article studies the problem of identifying lags when applying instruments of stabilisation financial policy of the state. The author justifies a scientific and methodical approach to this identification. It offers a selection of instruments of money-loan and budget-tax policies, which exert the biggest influence upon the general indicator of the state of economy. These instruments are as follows: average weighted rate by all instruments (average quarterly value); refinancing of banks by t...

  8. Global Stabilisation of Underactuated Mechanical Systems via PID Passivity-Based Control

    OpenAIRE

    2016-01-01

    In this note we identify a class of underactuated mechanical systems whose desired constant equilibrium position can be globally stabilised with the ubiquitous PID controller. The class is characterised via some easily verifiable conditions on the systems inertia matrix and potential energy function, which are satisfied by many benchmark examples. The design proceeds in two main steps, first, the definition of two new passive outputs whose weighted sum defines the signal around which the PID ...

  9. Phenolic stabilisers extraction constants of polypropylene geotextiles determination in alkali medium

    OpenAIRE

    Farcas, Fabienne; Fayolle, Bruno; Azzouz, Mériam; Richaud, Emmanuel

    2012-01-01

    The use of geotextiles made of polypropylene (PP) in civil engineering such as tunnel requieres adequates control over their durability, and this characteristic remains poorly known due to their inaccessibility. Considering concrete environment ageing conditions (alkali medium i.e. pH = 9 to 13), the aim of this study is to complete a non-empirical kinetic model for polypropylene ageing by the determination of the extraction parameters a frequently used phenolic process stabilisers: Irganox 1...

  10. Global exponential stabilisation of a class of nonlinear time-delay systems

    Science.gov (United States)

    Benabdallah, Amel; Echi, Nadhem

    2016-12-01

    This paper deals with the state and output feedback stabilisation problems for a family of nonlinear time-delay systems satisfying some relaxed triangular-type condition. The delay is supposed to be constant. Parameter-dependent control laws are used to compensate for the nonlinearities. Based on the Lyapunov-Krasovskii functionals, global exponential stability of the closed-loop systems is achieved. Finally, an extension to nonlinear time-varying delay systems is given.

  11. Formulation, characterisation and topical application of oil powders from whey protein stabilised emulsions / Magdalena Kotze

    OpenAIRE

    Kotze, Magdalena

    2014-01-01

    The available literature indicates that to date, few research has been performed on oil powders for topical delivery. The aim of this project was to investigate the release characteristics of oil powder formulations, as well as their dermal and transdermal delivery properties. Whey protein-stabilised emulsions were used to develop oil powders. Whey protein was used alone, or in combination with chitosan or carrageenan. Nine oil powders, with salicylic acid as the active ingredient, were fo...

  12. Decentralised stabilising controllers for a class of large-scale linear systems

    Indian Academy of Sciences (India)

    B C Jha; K Patralekh; R Singh

    2000-12-01

    A simple method for computing decentralised stabilising controllers for a class of large-scale (interconnected) linear systems has been developed. Decentralised controls are optimal controls at subsystem level and are generated from the solution of algebraic Riccati equations for decoupled subsystems resulting from a new aggregation-decomposition technique. The method has been illustrated through a numerical example of a large-scale linear system consisting of three subsystems each of the fourth order.

  13. EMDR versus stabilisation in traumatised asylum seekers and refugees: results of a pilot study

    OpenAIRE

    ter Heide, F. Jackie June; Trudy M. Mooren; Kleijn, Wim; de Jongh, Ad; Kleber, Rolf J.

    2011-01-01

    Background: Traumatised asylum seekers and refugees are clinically considered a complex population. Discussion exists on whether with this population treatment guidelines for post-traumatic stress disorder (PTSD) should be followed and Trauma-Focused Cognitive-Behavioural Therapy (TF-CBT) or Eye Movement Desensitisation and Reprocessing (EMDR) should be applied, or whether a phased model starting with stabilisation is preferable. Some clinicians fear that trauma-focused interventions may lead...

  14. Cooling and thermal stabilisation of Faraday rotators in the temperature range 300 — 200 K using Peltier elements

    Science.gov (United States)

    Palashov, O. V.; Ievlev, Ivan V.; Perevezentsev, E. A.; Katin, E. V.; Khazanov, Efim A.

    2011-09-01

    A new method for cooling and thermal stabilisation of Faraday rotators using Peltier elements is proposed and experimentally demonstrated. The scheme of thermal stabilisation of the magnetooptical elements ensures reliable operation of the device at the absorbed power ~2 W, which corresponds to the transmitted laser radiation power 1.5 kW. The results of the work make it possible to predict high efficiency of this method at the laser power of tens of kilowatts.

  15. Cooling and thermal stabilisation of Faraday rotators in the temperature range 300 - 200 K using Peltier elements

    Energy Technology Data Exchange (ETDEWEB)

    Palashov, O V; Ievlev, Ivan V; Perevezentsev, E A; Katin, E V; Khazanov, Efim A [Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod (Russian Federation)

    2011-09-30

    A new method for cooling and thermal stabilisation of Faraday rotators using Peltier elements is proposed and experimentally demonstrated. The scheme of thermal stabilisation of the magnetooptical elements ensures reliable operation of the device at the absorbed power {approx}2 W, which corresponds to the transmitted laser radiation power 1.5 kW. The results of the work make it possible to predict high efficiency of this method at the laser power of tens of kilowatts.

  16. Role of phyto-stabilised silver nanoparticles in suppressing adjuvant induced arthritis in rats.

    Science.gov (United States)

    Mani, Aparna; Vasanthi, C; Gopal, V; Chellathai, Darling

    2016-12-01

    The present study was aimed to evaluate the anti-arthritic effects of silver nanoparticles synthesised using Piper nigrum extract and to further establish its mechanism of action in a rat model of adjuvant induced arthritis (AA). Adjuvant arthritis was induced by injecting complete Freund's adjuvant (0.1mL) into the left hind paw of 36 albino Wistar rats (n=6). Silver nanoparticles stabilised with Piper nigrum extract (25 and 50mg/kg). Commercial silver nanoparticles (50mg/kg) and methotrexate (0.1mg/kg) were administered by intraperitoneal route from day 11 to day 22 on alternate days. It was found that treatment with silver nanoparticles stabilised with Piper nigrum (S-AgNPs) significantly reduced the paw edema and alleviated the histopathological changes of cell infiltration, synovial hyperplasia, bone and cartilage destruction. Furthermore, the phytostabilised silver nanoparticles (S-AgNPs) inhibited the protein expression of NF-kβ p65 and TNF-α as evidenced by immunohistochemistry analysis. Our current findings suggest that silver nanoparticles stabilised with Piper nigrum extract (S-AgNPs) have potent anti-arthritic activity which is mediated by inhibition of TNF-α and suppression of pro-inflammatory cytokines that are secreted in response to activated transcription factors of NF-kβ. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Stabilisation of Na,K-ATPase structure by the cardiotonic steroid ouabain

    Energy Technology Data Exchange (ETDEWEB)

    Miles, Andrew J. [Institute of Structural and Molecular Biology, Birkbeck College, University of London, London WC1E 7HX (United Kingdom); Fedosova, Natalya U. [Department of Biomedicine, Aarhus University, DK-8000 Aarhus (Denmark); Hoffmann, Søren V. [ISA, Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus (Denmark); Wallace, B.A. [Institute of Structural and Molecular Biology, Birkbeck College, University of London, London WC1E 7HX (United Kingdom); Esmann, Mikael, E-mail: me@biophys.au.dk [Department of Biomedicine, Aarhus University, DK-8000 Aarhus (Denmark)

    2013-05-31

    Highlights: •Ouabain binding to pig and shark Na,K-ATPase enhances thermal stability. •Ouabain stabilises both membrane-bound and solubilised Na,K-ATPase. •Synchrotron radiation circular dichroism is used for structure determination. •Secondary structure in general is not affected by ouabain binding. •Stabilisation is due to re-arrangement of tertiary structure. -- Abstract: Cardiotonic steroids such as ouabain bind with high affinity to the membrane-bound cation-transporting P-type Na,K-ATPase, leading to complete inhibition of the enzyme. Using synchrotron radiation circular dichroism spectroscopy we show that the enzyme-ouabain complex is less susceptible to thermal denaturation (unfolding) than the ouabain-free enzyme, and this protection is observed with Na,K-ATPase purified from pig kidney as well as from shark rectal glands. It is also shown that detergent-solubilised preparations of Na,K-ATPase are stabilised by ouabain, which could account for the successful crystallisation of Na,K-ATPase in the ouabain-bound form. The secondary structure is not significantly affected by the binding of ouabain. Ouabain appears however, to induce a reorganization of the tertiary structure towards a more compact protein structure which is less prone to unfolding; recent crystal structures of the two enzymes are consistent with this interpretation. These circular dichroism spectroscopic studies in solution therefore provide complementary information to that provided by crystallography.

  18. Solidification/stabilisation of liquid oil waste in metakaolin-based geopolymer

    Energy Technology Data Exchange (ETDEWEB)

    Cantarel, V.; Nouaille, F.; Rooses, A.; Lambertin, D., E-mail: david.lambertin@cea.fr; Poulesquen, A.; Frizon, F.

    2015-09-15

    Highlights: • Formulation with 20 vol.% of oil in a geopolymer have been successful tested. • Oil waste is encapsulated as oil droplets in metakaolin-based geopolymer. • Oil/geopolymer composite present good mechanical performance. • Carbon lixiviation of oil/geopolymer composite is very low. - Abstract: The solidification/stabilisation of liquid oil waste in metakaolin based geopolymer was studied in the present work. The process consists of obtaining a stabilised emulsion of oil in a water-glass solution and then adding metakaolin to engage the setting of a geopolymer block with an oil emulsion stabilised in the material. Geopolymer/oil composites have been made with various oil fraction (7, 14 and 20 vol.%). The rigidity and the good mechanical properties have been demonstrated with compressive strength tests. Leaching tests evidenced the release of oil from the composite material is very limited whereas the constitutive components of the geopolymer (Na, Si and OH{sup −}) are involved into diffusion process.

  19. Avalanches of coalescence events and local extensional flows--stabilisation or destabilisation due to surfactant.

    Science.gov (United States)

    Gunes, Deniz Z; Clain, Xavier; Breton, Olivier; Mayor, Guy; Burbidge, Adam S

    2010-03-01

    From two-drop collision experiments, it is known that local extensional flow favors coalescence. Recently, Bremond et al. used microfluidic methods to evidence this point. Similarly, we used specific microfluidic geometries to impose sudden extensional flow, following drop collision under controlled conditions, and coalescence events were recorded with a high-speed camera. In this study we focus on the effect of surfactant on the coalescence, or stabilisation against it, between drops flowing apart due to either imposed external flow or capillary forces related to drop shape relaxation. Coalescence can be induced even when drops are initially separated by an intersticial lubricating film by far thicker than the critical thickness for rupturing under the action of Van der Waals forces. This is particularly relevant to avalanches of coalescence events, in flowing or even quiescent emulsions or foams. When non-ionic surfactant was used, it was observed that small concentrations apparently enhance coalescence in extension. But at higher concentrations it provides stabilisation through a specific mechanism of thread formation and rupture; the stabilisation mechanism can be complex.

  20. Interfacial behaviour of sodium stearoyllactylate (SSL) as an oil-in-water pickering emulsion stabiliser.

    Science.gov (United States)

    Kurukji, D; Pichot, R; Spyropoulos, F; Norton, I T

    2013-11-01

    The ability of a food ingredient, sodium stearoyllactylate (SSL), to stabilise oil-in-water (O/W) emulsions against coalescence was investigated, and closely linked to its capacity to act as a Pickering stabiliser. Results showed that emulsion stability could be achieved with a relatively low SSL concentration (≥0.1 wt%), and cryogenic-scanning electron microscopy (cryo-SEM) visualisation of emulsion structure revealed the presence of colloidal SSL aggregates adsorbed at the oil-water interface. Surface properties of SSL could be modified by altering the size of these aggregates in water; a faster decrease in surface tension was observed when SSL dispersions were subjected to high pressure homogenisation (HPH). The rate of SSL adsorption at the sunflower oil-water interface also increased after HPH, and a higher interfacial tension (IFT) was observed with increasing SSL concentration. Differential scanning calorimetry (DSC) enabled a comparison of the thermal behaviour of SSL in aqueous dispersions with SSL-stabilised O/W emulsions. SSL melting enthalpy depended on emulsion interfacial area and the corresponding DSC data was used to determine the amount of SSL adsorbed at the oil-water interface. An idealised theoretical interfacial coverage calculation based on Pickering emulsion theory was in general agreement with the mass of SSL adsorbed as predicted by DSC.

  1. Geotechnical properties of peat soil stabilised with shredded waste tyre chips

    Directory of Open Access Journals (Sweden)

    M.A. Rahgozar

    2016-02-01

    Full Text Available To accommodate major civil engineering projects in or in the vicinity of peatlands, it is essential to stabilise peat deposits. On the other hand, the accumulation of waste tyres in recent decades has caused environmental problems around the world. An effective remedy for both issues is to use scrap tyre material to stabilise problematic peat soils. This article reports an experimental investigation of the effects of adding shredded tyre chips on the stability and bearing capacity of peat soil. Peat soil samples from the Chaghakhor Wetland (Chaharmahal and Bakhtiari Province, Iran were mixed with sand at a constant dosage of 400 kg m-3 and different percentages (0 %, 5 %, 10 %, 15 % and 20 % by weight of shredded tyre chips. The unconfined compressive strength, effective cohesion, angle of internal friction and coefficient of permeability were measured for all of these mixtures. The results showed that adding shredded tyre chips significantly improved the geotechnical properties of the peat soil. The mixture with 10 % shredded tyre chips showed the highest unconfined compressive strength; the one with 15 % tyre chips exhibited the highest ductility; and adding 20 % shredded tyre chips provided the highest values for angle of internal friction, effective cohesion and coefficient of permeability. Scanning Electron Micrographs (SEM showed that the pore spaces in the stabilised peat were mostly filled with sand.

  2. Modulus stabilisation in a backreacted warped geometry model via Goldberger-Wise mechanism

    CERN Document Server

    Das, Ashmita; SenGupta, Soumitra

    2016-01-01

    In the context of higher dimensional braneworld scenario, the stabilisation of extra dimensional modulus is an essential requirement for resolving the gauge hierarchy problem in the context of Standard Model of elementary particle Physics. For Randall-Sundrum (RS) warped extra dimensional model, Goldberger and Wise (GW) proposed a much useful mechanism to achieve this using a scalar field in the bulk spacetime ignoring the effects of backreaction of the scalar field on the background metric. In this article we examine the influence of the backreaction of the stabilising field on the stabilisation condition as well as that on the Physics of the extra dimensional modulus namely radion. In particular we obtain the modifications of the mass and the coupling of the radion with the Standard Model (SM) matter fields on the TeV brane due to backreaction effect. Our calculation also brings out an important equivalence between the treatments followed by Csaki et.al. in \\cite{kribs} and Goldberger-Wise in \\cite{GW1,GW_r...

  3. Integrated waste management as a climate change stabilisation wedge for the Maltese islands.

    Science.gov (United States)

    Falzon, Clyde; Fabri, Simon G; Frysinger, Steven

    2013-01-01

    The continuous increase in anthropogenic greenhouse gas emissions occurring since the Industrial Revolution is offering significant ecological challenges to Earth. These emissions are leading to climate changes which bring about extensive damage to communities, ecosystems and resources. The analysis in this article is focussed on the waste sector within the Maltese islands, which is the largest greenhouse gas emitter in the archipelago following the energy and transportation sectors. This work shows how integrated waste management, based on a life cycle assessment methodology, acts as an effective stabilisation wedge strategy for climate change. Ten different scenarios applicable to the Maltese municipal solid waste management sector are analysed. It is shown that the scenario that is most coherent with the stabilisation wedges strategy for the Maltese islands consists of 50% landfilling, 30% mechanical biological treatment and 20% recyclable waste export for recycling. It is calculated that 16.6 Mt less CO2-e gases would be emitted over 50 years by means of this integrated waste management stabilisation wedge when compared to the business-as-usual scenario. These scientific results provide evidence in support of policy development in Malta that is implemented through legislation, economic instruments and other applicable tools.

  4. The distribution and stabilisation of dissolved Fe in deep-sea hydrothermal plumes

    Science.gov (United States)

    Bennett, Sarah A.; Achterberg, Eric P.; Connelly, Douglas P.; Statham, Peter J.; Fones, Gary R.; German, Christopher R.

    2008-06-01

    We have conducted a study of hydrothermal plumes overlying the Mid-Atlantic Ridge near 5° S to investigate whether there is a significant export flux of dissolved Fe from hydrothermal venting to the oceans. Our study combined measurements of plume-height Fe concentrations from a series of 6 CTD stations together with studies of dissolved Fe speciation in a subset of those samples. At 2.5 km down plume from the nearest known vent site dissolved Fe concentrations were ˜ 20 nM. This is much higher than would be predicted from a combination of plume dilution and dissolved Fe(II) oxidation rates, but consistent with stabilisation due to the presence of organic Fe complexes and Fe colloids. Using Competitive Ligand Exchange-Cathodic Stripping Voltammetry (CLE-CSV), stabilised dissolved Fe complexes were detected within the dissolved Fe fraction on the edges of one non-buoyant hydrothermal plume with observed ligand concentrations high enough to account for stabilisation of ˜ 4% of the total Fe emitted from the 5° S vent sites. If these results were representative of all hydrothermal systems, submarine venting could provide 12-22% of the global deep-ocean dissolved Fe budget.

  5. The stabilisation and transportation of dissolved iron from high temperature hydrothermal vent systems

    Science.gov (United States)

    Hawkes, J. A.; Connelly, D. P.; Gledhill, M.; Achterberg, E. P.

    2013-08-01

    Iron (Fe) binding phases in two hydrothermal plumes in the Southern Ocean were studied using a novel voltammetric technique. This approach, reverse titration-competitive ligand exchange-adsorptive cathodic stripping voltammetry, showed that on average 30±21% of dissolved Fe in the hydrothermal plumes was stabilised by chemically labile binding to ligands. The conditional stability constant (log K‧FeL) of the observed complexes was 20.61±0.54 (mean±1 SD) for the two vent sites, intermediate between previous measurements of deep ocean ligands (21.4-23; Kondo et al., 2012) and dissolved weak estuarine ligands (<20; Gerringa et al., 2007). Our results indicate that approximately 7.5% of all hydrothermal Fe was stabilised by complexation with ligands. Furthermore, 47±26% of the dissolved Fe in the plume existed in the colloidal size range (0.02-0.2 μm). Our data suggests that a portion (∼7.5%) of hydrothermal Fe is sufficiently stabilised in the dissolved size fraction (<0.2 μm) to make an important impact on deep ocean Fe distributions. Lateral deep ocean currents transport this hydrothermal Fe as lenses of enhanced Fe concentrations away from mid ocean ridge spreading centres and back arc basins.

  6. Pemasangan Implan Endodontik sebagai Stabilisator Pasca Apikoektomi Gigi Premolar Dua Kanan Bawah

    Directory of Open Access Journals (Sweden)

    Andreas Edwin

    2016-11-01

    Full Text Available Latar Belakang: Gigi yang tidak didukung akar yang cukup panjang akan kesulitan menahan beban kunyah dan akan terjadi kegoyahan. Implan endodontik dapat digunakan sebagai alternatif stabilisator pada gigi dengan panjang akar yang tidak memadai. Tujuan: untuk memberikan informasi mengenai perawatan gigi premolar kedua bawah kanan yang mengalami perforasi eksternal dan harus menjalani perawatan apikoektomi dengan menggunakan MOl sebagai stabilisator endodontik. Kasus: seorang wanita, 23 tahun, datang dalam keadaan gigi sakit sebelah belakang kanan bawah. Beberapa tahun yang lalu pasien menjalani operasi pengambilan gigi supernumerary pada area tersebut. Beberapa bulan setelah operasi pasien mengeluhkan adanya rasa nyeri. Gambaran radiograf tampak ada area radiolusen bagian mesial gigi 46 dan di bagian distal gigi 45. Hal ini diperkirakan karena tindakan iatrogenik operasi pengambilan gigi supernumerary. Gigi 45 dirawat dengan prosedur apikoektomi dilanjutkan dengan bedah pemasangan implan endodontik sebagai stabilisator. Manajemen kasus: dilakukan bedah apikoektomi, bersamaan dengan bedah apikoektomi dilakukan pemasangan implan endodontik. Material implan yang digunakan adalah Mini Oental lmplant berukuran 1,8 mm panjang 15 mm. Bagian akar yang berbatasan dengan implan ditutup dengan MTA sebagai penutup tepi. Kesimpulan: pemasangan implan endodontik pada gigi 45 telah di evaluasi selama 45 hari sejak prosedur bedah dilakukan menunjukkan pasien tidak mengalami keluhan dan secara klinis tidak ada kelainan pada gigi 45 tersebut. Gigi siap direstorasi dengan mahkota jembatan porselen fusi metal.

  7. Stabilising cubosomes with Tween 80 as a step towards targeting lipid nanocarriers to the blood-brain barrier.

    Science.gov (United States)

    Azhari, Hanisah; Strauss, Mike; Hook, Sarah; Boyd, Ben J; Rizwan, Shakila B

    2016-07-01

    Coating nanoparticles with the surfactant Tween 80 have been previously shown to enhance drug delivery across the blood-brain barrier (BBB). The aim of this study was to investigate whether Tween 80 could be used to stabilise phytantriol-based cubosomes thereby enabling potential application in delivering macromolecular therapeutics to the brain. Cubosome particles with their large internal and external surface area by virtue of their nanostructure are ideal for delivery of macromolecules. Phase behaviour studies were conducted using a combination of optical microscopy and small-angle X-ray scattering (SAXS) and the addition of Tween 80 to mixtures of phytantriol and water resulted in a rich array of lyotropic mesophases. In particular, a large cubic phase region and a two-phase region of readily dispersed cubosomes is observed. Cubosomes with different concentrations of Tween 80 and phytantriol as the liquid crystal forming lipid were prepared using the solvent precursor method and their physical properties were investigated. A combination of dynamic light scattering, cryogenic electron tomography and SAXS shows formation of well-defined cubosomes with a narrow size distribution and the Im3m cubic structure. Collectively, the results confirm that Tween 80 can effectively stabilize phytantriol cubosomes, opening the possibility for future application in drug delivery across the BBB. Moreover, well-defined, homogenous cubosome formulations prepared using the mild solvent precursor dilution method has significant implications for large-scale production of cubosomes, which currently is a major barrier to the application of cubosomes in the clinic.

  8. $\\alpha'$ Inflation: Moduli Stabilisation and Observable Tensors from Higher Derivatives

    CERN Document Server

    Cicoli, Michele; de Alwis, Senarath; Muia, Francesco

    2016-01-01

    The leading order dynamics of the type IIB Large Volume Scenario is characterised by the interplay between $\\alpha'$ and non-perturbative effects which fix the overall volume and all local blow-up modes leaving (in general) several flat directions. In this paper we show that, in an arbitrary Calabi-Yau with at least one blow-up mode resolving a point-like singularity, any remaining flat directions can be lifted at subleading order by the inclusions of higher derivative $\\alpha'$ corrections. We then focus on simple fibred cases with one remaining flat direction which can behave as an inflaton if its potential is generated by both higher derivative $\\alpha'$ and winding loop corrections. Natural values of the underlying parameters give a spectral index in agreement with observational data and a tensor-to-scalar ratio of order $r=0.01$ which could be observed by forthcoming CMB experiments. Dangerous corrections from higher dimensional operators are suppressed due to the presence of an approximate non-compact s...

  9. Stabilising falling liquid film flows using feedback control

    CERN Document Server

    Thompson, Alice B; Pavliotis, Grigorios A; Papageorgiou, Demetrios T

    2015-01-01

    The flow of a fluid layer with one interface exposed to the air and the other an inclined planar wall becomes unstable due to inertial effects when the fluid layer is sufficiently thick or the slope sufficiently steep. This free surface flow of a single fluid layer has industrial applications including coating and heat transfer, which benefit from smooth and wavy interfaces, respectively. Here we discuss how the dynamics of the system are altered by introducing deliberately spatially-varying or time-dependent perturbations via the injection and suction of fluid through the wall. We find that injection and suction is a remarkably effective control mechanism: the controls can be used to drive the system towards arbitrary steady states and travelling waves, and the qualitative effects are independent of the details of the flow modelling. Furthermore, the system can still be successfully controlled even if the feedback must be applied via a set of localised actuators, and only a small number of system observation...

  10. α' Inflation: moduli stabilisation and observable tensors from higher derivatives

    Science.gov (United States)

    Cicoli, Michele; Ciupke, David; de Alwis, Senarath; Muia, Francesco

    2016-09-01

    The leading order dynamics of the type IIB Large Volume Scenario is characterised by the interplay between α' and non-perturbative effects which fix the overall volume and all local blow-up modes leaving (in general) several flat directions. In this paper we show that, in an arbitrary Calabi-Yau with at least one blow-up mode resolving a point-like singularity, any remaining flat directions can be lifted at subleading order by the inclusions of higher derivative α' corrections. We then focus on simple fibred cases with one remaining flat direction which can behave as an inflaton if its potential is generated by both higher derivative α' and winding loop corrections. Natural values of the underlying parameters give a spectral index in agreement with observational data and a tensor-to-scalar ratio of order r = 0 .01 which could be observed by forthcoming CMB experiments. Dangerous corrections from higher dimensional operators are suppressed due to the presence of an approximate non-compact shift symmetry.

  11. Radiographic measurement of key parameters used in the unilateral transpedicular approach on percutaneous kyphoplasty%单侧入路经皮椎体后凸成形术关键参数的影像学测量

    Institute of Scientific and Technical Information of China (English)

    翟伟峰; 贾永伟; 王建杰; 程黎明

    2015-01-01

    目的 探索基于影像学测量获得单侧入路经皮椎体后凸成形术的关键参数,为临床操作提供参考. 方法 随机选择我科住院患者的胸椎、腰椎CT片各120例,利用我院影像科PACS系统、Uniweb Server软件,通过模拟单侧入路经皮椎体后凸成形术的最佳穿刺路径,测出T4 ~L5 椎体穿刺路径的内倾角、尾倾角、皮肤入针点旁开棘突的距离. 并结合临床实践,验证数据的准确性. 结果 单侧穿刺途径:T4 ~T9 椎体,内倾角(24.6 ± 4.2)°,尾倾角(19.8 ±1.8)°,棘突旁开距离(3.5 ±0.5)cm. T10 ~L2 椎体,内倾角(25.6 ±4.8)°,尾倾角(18.5 ± 1.6)°,棘突旁开距离(3.8 ±0.6)cm. L3 ~L5 椎体,内倾角(34.2 ±7.8)°,尾倾角(17.5 ±1.9)°,棘突旁开距离(5.9 ±1.2) cm. 结论 基于影像学测量获得关键参数,是顺利进行单侧入路经皮椎体后凸成形术的重要依据,根据测量的数据指导临床实践,操作简便、安全,穿刺准确性高,对临床操作有一定的参考价值.%Objective To obtain the key parameters required for the unilateral transpedicular approach on percuta-neous kyphoplasty through imaging measurement, so as to provide evidence for clinical practice.Methods A total of 120 CT images of thoracic and lumbar vertebrae were randomly collected from patients in our department.Then, using the PACS system and Uniweb Server software, the angles of introvertion and declination, and the distance between the skin entry point and the spinous process from T4 to L5 were measured through imitation of percutaneous kyphoplasty via the u-nilateral transpedicular approach.Meanwhile, the accuracy of the measurement was verified on the basis of clinical prac-tice.Results The unilateral transpedicular puncture yielded an introvertion angle of (24.6 ±4.2) for T4 -T9 , (25.6 ±4.8) for T10 -L2 and (34.2 ±7.8) for L3 -L5 and a declination angle of (19.8 ±1.8) for T4 -T9, (18.5 ±1.6) for T10 -L2 and (17.5 ±1.9) for L3 -L5 .The distance

  12. Effectiveness of arthroscopic versus open surgical stabilisation for the management of traumatic anterior glenohumeral instability.

    Science.gov (United States)

    Ng, Choong; Bialocerkowski, Andrea; Hinman, Rana

    2007-06-01

    Background  Anterior instability is a frequent complication following a traumatic glenohumeral dislocation. Frequently the underlying pathology associated with recurrent instability is a Bankart lesion. Surgical correction of Bankart lesions and other associated pathology is the key to successful treatment. Open surgical glenohumeral stabilisation has been advocated as the gold standard because of consistently low postoperative recurrent instability rates. However, arthroscopic glenohumeral stabilisation could challenge open surgical repair as the gold standard treatment for traumatic anterior glenohumeral instability. Objectives  Primary evidence that compared the effectiveness of arthroscopic versus open surgical glenohumeral stabilisation was systematically collated regarding best-practice management for adults with traumatic anterior glenohumeral instability. Search strategy  A systematic search was performed using 14 databases: MEDLINE, Cumulative Index of Nursing and Allied Health (CINAHL), Allied and Complementary Medicine Database (AMED), ISI Web of Science, Expanded Academic ASAP, Proquest Medical Library, Evidence Based Medicine Reviews, Physiotherapy Evidence Database, TRIP Database, PubMed, ISI Current Contents Connect, Proquest Digital Dissertations, Open Archives Initiative Search Engine, Australian Digital Thesis Program. Studies published between January 1984 and December 2004 were included in this review. No language restrictions were applied. Selection criteria  Eligible studies were those that compared the effectiveness of arthroscopic versus open surgical stabilisation for the management of traumatic anterior glenohumeral instability, which had more than 2 years of follow up and used recurrent instability and a functional shoulder questionnaire as primary outcomes. Studies that used non-anatomical open repair techniques, patient groups that were specifically 40 years or older, or had multidirectional instability or other concomitant

  13. Fly ashes as binders for the stabilisation of gravel. Laboratory tests and preparations for a field test; Flygaskor som bindemedel foer stabilisering av grusmaterial. Laboratorieundersoekningar samt foerberedelser infoer provbyggandet

    Energy Technology Data Exchange (ETDEWEB)

    Lahtinen, Pentti; Jyraevae, Harri; Maijala, Aino; Macsik, Josef

    2005-04-01

    The project is based on the results of a significant research project FACE (Fly Ash in Civil Engineering). The project aims at the development of binder recipes based on a chosen fly ash from Holmen Paper's Hallsta Pappersbruk for the renovation of a road. The development will benefit from the Finnish research and experience on this type of binders for geotechnical applications. The stabilisation should result in improving bearing capacity and better long-term durability and service life of the gravel roads. The environmentally friendly stabilisation system comprises also the possibility to reuse and recycle the material that already exists in the road to be renovated. The test materials for the development project were the gravel from a chosen test road and the fly ash of Holmen Paper AB. The fly ash was used as the binder material. The geotechnical tests included characterisation tests of the test materials, tests on the stabilised mixes and control tests for the stabilisation recipe. Also, there were tests for the assessment of the environmental impact of the stabilisation. Side by side with those tests there has been a full-scale test, a separate project in Hallstavik, to test the stabilisation process with respect to the technical, environmental and economical aspects of construction. The full-scale test will be reported separately. The project results imply that fly ash can be beneficially used as a binder for the stabilisation of gravel materials and similar materials. Fly ash can be used also with small amounts of other binder materials like cement or blast-furnace slag in order to have a frost resistant material. The project gives also basis for the development of binders for other types of applications, both for the renovation purposes and for the improvement of spoils for construction purposes.

  14. Molecular dynamics simulations in rational protein design : Stabilisation of fusarium solani pisi cutinase against anionic surfactants

    NARCIS (Netherlands)

    Creveld, Lucia Deborah

    2001-01-01

    Cutinases are enxymes with a molecular mass of 22-25 kDa that supposedly degrade ester bonds of the cutin polymer in the plant cell wall. They are serine esterases, also able to hydrolyse a wide variety of synthetic esters and triacylglycerols. As cutinase is an efficient catalyst both in solution a

  15. Molecular dynamics simulations in rational protein design : Stabilisation of fusarium solani pisi cutinase against anionic surfactants

    NARCIS (Netherlands)

    Creveld, Lucia Deborah

    2001-01-01

    Cutinases are enxymes with a molecular mass of 22-25 kDa that supposedly degrade ester bonds of the cutin polymer in the plant cell wall. They are serine esterases, also able to hydrolyse a wide variety of synthetic esters and triacylglycerols. As cutinase is an efficient catalyst both in solution

  16. An optimised small-molecule stabiliser of the 14-3-3-PMA2 protein-protein interaction.

    Science.gov (United States)

    Richter, Anja; Rose, Rolf; Hedberg, Christian; Waldmann, Herbert; Ottmann, Christian

    2012-05-21

    Modulation of protein-protein interactions (PPIs) is a highly demanding, but also a very promising approach in chemical biology and targeted drug discovery. In contrast to inhibiting PPIs with small, chemically tractable molecules, stabilisation of these interactions can only be achieved with complex natural products, like rapamycin, FK506, taxol, forskolin, brefeldin and fusicoccin. Fusicoccin stabilises the activatory complex of the plant H(+)-ATPase PMA2 and 14-3-3 proteins. Recently, we have shown that the stabilising effect of fusicoccin could be mimicked by a trisubstituted pyrrolinone (pyrrolidone1, 1). Here, we report the synthesis, functional activity and crystal structure of derivatives of 1 that stabilise the 14-3-3-PMA2 complex. With a limited compound collection three modifications that are important for activity enhancement could be determined: 1) conversion of the pyrrolinone scaffold into a pyrazole, 2) introduction of a tetrazole moiety to the phenyl ring that contacts PMA2, and 3) addition of a bromine to the phenyl ring that exclusively contacts the 14-3-3 protein. The crystal structure of a pyrazole derivative of 1 in complex with 14-3-3 and PMA2 revealed that the more rigid core of this molecule positions the stabiliser deeper into the rim of the interface, enlarging especially the contact surface to PMA2. Combination of the aforementioned features gave rise to a molecule (37) that displays a threefold increase in stabilising the 14-3-3-PMA2 complex over 1. Compound 37 and the other active derivatives show no effect on two other important 14-3-3 protein-protein interactions, that is, with CRaf and p53. This is the first study that describes the successful optimisation of a PPI stabiliser identified by screening. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Protective benefits of a stabilised stannous-containing fluoride dentifrice against erosive acid damage.

    Science.gov (United States)

    Faller, Robert V; Eversole, Sandra L; Saunders-Burkhardt, Kymberly

    2014-03-01

    To assess the potential of a stabilised stannous (Sn)-containing NaF dentifrice (Oral B/blend-a-Med(®) Pro-Expert), in addition to a number of other marketed European dentifrices formulated with various fluoride actives and two control dentifrices, to protect enamel against erosive acid damage. Cores of human enamel (four per group) were soaked in pooled human saliva, and then treated with a 1:3 slurry (dentifrice:saliva) using a standardised in vitro erosion model (5-day cycling) that includes 10-minute challenges with 1% citric acid applied 60 minutes after each dentifrice treatment. Enamel surface loss was measured using transverse microradiography (TMR). Specimens treated with the Sn-containing NaF dentifrice showed 6.5 μm of surface loss ± 1.2 (SEM), which was not significantly different (P Sensodyne(®) ProNamel(™) : (1,450 ppm F as NaF + KNO3 ) 20.5 μm (1.26); Crest Cavity Protection (1,100 ppm F as NaF, reference control) 22.00 μm (2.04); and Mentadent(®) : (1,450 ppm F as NaF + Zn citrate) 22.3 μm (0.63). These results support the potential for the stabilised, Sn-containing NaF dentifrice to provide erosion protection benefits that are not significantly different from the positive control benchmark for erosion protection (stabilised SnF2 ), and are significantly better than a broad range of dentifrice formulations available on the European market. © 2014 FDI World Dental Federation.

  18. Stabilisation of strawberry (Fragaria x ananassa Duch.) anthocyanins by different pectins.

    Science.gov (United States)

    Buchweitz, M; Speth, M; Kammerer, D R; Carle, R

    2013-12-01

    The objective of the present study was to evaluate the effects of different pectins on strawberry anthocyanins in viscous model solutions at pH 3.0. For this purpose, low esterified amidated, low and high methyl esterified citrus and apple pectins, and a sugar beet pectin (SBP), respectively, were added to strawberry extracts. The latter were predominantly composed of pelargonidin-glycosides, containing either reduced (E-1) or original amounts of non-anthocyanin phenolics (E-2). Model systems were stored for 18 weeks at 20±0.5 °C protected from light, and anthocyanins were quantitated in regular intervals by HPLC-DAD analyses. Half-life (t1/2) and destruction (D) values were calculated based on first-order kinetics. Generally, significant differences in pigment retention could be ascribed to differing pectin sources, while variation in the degree of esterification and amidation, respectively, had negligible effects. Compared to systems without added pectin, apple pectins and SPB enhanced anthocyanin stability moderately, while stabilising effects of citrus pectins were poor or even imperceptible. Generally, the amount of non-anthocyanin phenolics and the addition of citrate did not markedly affect anthocyanin stability. However, pectins had no influence on total phenolic contents (Folin-Ciocalteu assay) and antioxidant capacities (FRAP and TEAC assay) of strawberry phenolics over time. For pelargonidin-3-glucoside and -rutinoside largely consistent stabilities were found in all model systems. In contrast, pelargonidin-3-malonylglucoside was less stable in the blank, and stabilisation by pectins was always negligible. The findings of the present study are contrary to results reported previously for the stabilisation of cyanidin- and delphinidin-glycosides in similar model systems prepared with black currant extracts, indicating a high impact of the number of hydroxyl groups in the anthocyanin B-ring.

  19. Application of C2 Transpedicular Screw Fixation Combined with C3 Lateral Mass Screw Plate Fixation in Posterior Treatment of Old Hangman's Fracture%经后路C2椎弓根C3侧块短节段固定治疗陈旧性枢椎椎弓骨折

    Institute of Scientific and Technical Information of China (English)

    曹成刚; 梁益建; 何睿; 石化洋; 曾勇; 陈伶

    2012-01-01

    Objective To approach the therapeutic effect of C2 transpedicular screw fixation combined with C3 lateral mass screw plate fixation on old Hangman' s fracture. Methods Nine patients with old Hangman' s fracture were treated with C2 transpedicular screw fixation combined with C3 lateral mass screw plate fixation as well as bone gr'aft fusion in our hospital from 2002. Results A mean follow-up time was 8 months(6 to 15 months). All cases got bony union. No infection, neurological deficits, or other complications were found. Conclusion It can be an effective and simple way to treat old Hangman' s fracture with C2 transpedicular screw fixation combined with C3 lateral mass screw plate fixation, which can ultimately preserve the cervical function.%目的 探讨经后路C2椎弓根C3侧块短节段内固定治疗陈旧性枢椎椎弓骨折(Hangman骨折)的疗效.方法 2002年以来9例陈旧性Hangman骨折采用经后路C2椎弓根C3侧块短节段固定,植骨融合治疗.结果 所有患者随访6~15个月,平均8个月.所有患者均骨性愈合,未出现感染、神经损伤等并发症.结论 经后路C2椎弓根C3侧块短节段内固定治疗陈旧性Hangman骨折是一种安全有效并能最大程度保留患者颈部功能的方法.

  20. 2D Stabilised analytic signal method in DC pole-pole potential data interpretation

    Indian Academy of Sciences (India)

    Paras R Pujari; Rambhatla G Sastry

    2003-03-01

    Using analytic signal method, interpretation of pole-pole secondary electric potentials due to 2D conductive/resistive prisms is presented. The estimated parameters are the location, lateral extent or width and depth to top surface of the prism. Forward modelling is attempted by 2D-Finite Difference method. The proposed stabilised analytic signal algorithm (RES2AS) uses Tikhonov's regularization scheme and FFT routines. The algorithm is tested on three theoretical examples and field data from the campus of Roorkee University. The stability of RES2AS is also tested on synthetic error prone secondary pole-pole potential data.

  1. Treatment of post-orthodontic white spot lesions with casein phosphopeptide-stabilised amorphous calcium phosphate

    DEFF Research Database (Denmark)

    Bröchner, Ann; Christensen, Carsten; Kristensen, Bjarne;

    2010-01-01

    This study aims to investigate the effect of topical applications of 10% casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on white spot lesions (WSL) detected after treatment with fixed orthodontic appliances. Sixty healthy adolescents with >/=1 clinically visible WSL at debonding were...... findings were largely reflected by the clinical scores. No side effects were reported. Topical treatment of white spot lesions after debonding of orthodontic appliances with a casein phosphopeptide-stabilised amorphous calcium phosphate agent resulted in significantly reduced fluorescence and a reduced...

  2. Asymptotic stabilisation for a class of feedforward input-delay systems with ratios of odd integers

    Science.gov (United States)

    Wu, Jian; Chen, Weisheng; Miao, Qiguang

    2013-11-01

    This article addresses the stabilisation problem by state-feedback for a class of feedforward input-delay nonlinear systems with ratios of odd integer powers. The designed controller achieves the global asymptotic stability. Based on the appropriate state transformation of time-delay systems and the Lyapunov method, the problem of controller design can be converted into the problem of finding a parameter which can be obtained by appraising the nonlinear terms of the systems. Finally, three simulation examples are given to illustrate the effectiveness of the control algorithm proposed in this article.

  3. Analysis of designed experiments by stabilised PLS Regression and jack-knifing

    DEFF Research Database (Denmark)

    Martens, Harald; Høy, M.; Westad, F.

    2001-01-01

    Pragmatical, visually oriented methods for assessing and optimising bi-linear regression models are described, and applied to PLS Regression (PLSR) analysis of multi-response data from controlled experiments. The paper outlines some ways to stabilise the PLSR method to extend its range...... the reliability of the linear and bi-linear model parameter estimates. The paper illustrates how the obtained PLSR "significance" probabilities are similar to those from conventional factorial ANOVA, but the PLSR is shown to give important additional overview plots of the main relevant structures in the multi...

  4. Optimisation of stabilised carboxylesterase NP for enantioselective hydrolysis of naproxen methyl ester

    CSIR Research Space (South Africa)

    Steenkamp, Lucia H

    2008-12-01

    Full Text Available of 99% and E of 576, which is over double that we previously 450 attained with CLECs of Candida rugosa lipase [19]. 451 452 An extra stabilisation of the enzyme with 2000 - 2300 ppm of formaldehyde revealed 453 that the conversion of 265 g/l ester... of a secondary alcohol reacts faster in reactions catalysed by 503 cholesterol esterase, lipase from Pseudomonas cepacia, and lipase from Candida 504 rugosa. J. Org. Chem. 1991, 56: 2656-2665. 505 4. Lalonde JJ, Govardhan C, Khalaf N, Martinez AG...

  5. Modelling, characterisation and uncertainties of stabilised pseudoelastic shape memory alloy helical springs

    DEFF Research Database (Denmark)

    Enemark, Søren; Santos, Ilmar; Savi, M. A.

    2016-01-01

    The thermo-mechanical behaviour of pseudoelastic shape memory alloy helical springs is of concern discussing stabilised and cyclic responses. Constitutive description of the shape memory alloy is based on the framework developed by Lagoudas and co-workers incorporating two modifications related...... resulting in 1.3% residual standard deviation relative to the full range force. Compared to the validation data set, the errors are below 10% relative to the full range of the complex modulus. Uncertainty analysis of the model parameters using a Markov chain Monte Carlo technique shows low to high parameter...

  6. COMBINATIONS OF BUFFER-STOCKS AND BUFFER-FUNDS FOR WOOL PRICE STABILISATION IN AUSTRALIA

    OpenAIRE

    Moir, Brian; Piggott, Roley R.

    1991-01-01

    In this paper a preliminary analysis is presented of a combined buffer-fund and buffer-stock as an alternative to a pure buffer-fund or a pure buffer stock for stabilising wool prices. The alternatives analysed are designed so that each provides the same prices to producers as did the Reserve Price Scheme over the period of analysis. Least-cost combinations of policy instruments are derived. The results show that there is considerable potential for cost savings to be made by combining buffer-...

  7. Stabilisation of ballooning modes in torsatrons with an externally applied toroidal current

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, W.A. [Ecole Polytechnique Federale, Lausanne (Switzerland). Centre de Recherche en Physique des Plasma (CRPP)

    1996-09-01

    It has been found that ideal ballooning modes can impose very restrictive volume average {beta} limits in torsatrons much below the typical values close to 5% that are required to be economically realisable as reactor systems and it has been shown that externally applied toroidal currents that are peaked can destabilise the Mercier criterion in this type of configuration. We will show here that if the applied currents are hollow, they can stabilise the ballooning modes without triggering Mercier instabilities and as a result raise the limiting {beta}* from 2% to 5%. (author) 3 figs., 10 refs.

  8. Spectroscopic properties of erbium-doped yttria-stabilised zirconia crystals

    Energy Technology Data Exchange (ETDEWEB)

    Ryabochkina, P A; Sidorova, N V [N.P. Ogarev Mordovian State University, Saransk (Russian Federation); Ushakov, S N; Lomonova, E E [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2014-02-28

    Yttria-stabilised zirconia crystals ZrO{sub 2} – Y{sub 2}O{sub 3} (6 mol %) – Er{sub 2}O{sub 3} (5.85 mol %) are grown by directional crystallisation in a cold container using direct RF melting. The spectral and luminescent properties of these crystals are studied in order to use them as active media of solid state lasers emitting in the wavelength range 1.5 – 1.7 μm. (active media)

  9. Experimental Investigations of Decentralised Control Design for The Stabilisation of Rotor-Gas Bearings

    DEFF Research Database (Denmark)

    Theisen, Lukas Roy Svane; Galeazzi, Roberto; Niemann, Hans Henrik;

    2015-01-01

    directions. Hardening and softening P-lead controllers are designed based on the models experimentally identified, and salient features of both controllers are discussed. Both controllers are implemented and validated on the physical test rig. Experimental results confirm the validity of the proposed......-Box identification for the design of stabilising controllers, capable of enabling the active lubrication of the journal. The root locus analysis shows that two different control solutions are feasible for the dampening of the first two eigenfrequencies of the rotor-gas bearing in the horizontal and vertical...

  10. COMBINATIONS OF BUFFER-STOCKS AND BUFFER-FUNDS FOR WOOL PRICE STABILISATION IN AUSTRALIA

    OpenAIRE

    Moir, Brian; Piggott, Roley R.

    1991-01-01

    In this paper a preliminary analysis is presented of a combined buffer-fund and buffer-stock as an alternative to a pure buffer-fund or a pure buffer stock for stabilising wool prices. The alternatives analysed are designed so that each provides the same prices to producers as did the Reserve Price Scheme over the period of analysis. Least-cost combinations of policy instruments are derived. The results show that there is considerable potential for cost savings to be made by combining buffer-...

  11. Global adaptive exponential stabilisation for nonlinear systems with multiple unknown control directions

    Science.gov (United States)

    Sun, Xifang; Chen, Weisheng; Wu, Jian

    2016-12-01

    In this paper, we address the global generalised exponential stabilisation problem for a class of lower-triangular systems with multiple unknown directions. Instead of the well-known Nussbaum-gain adaptive rule, a Lyapunov-based adaptive logic switching rule is proposed to seek the correct control directions for such systems. The main advantage of the proposed controller is that it can guarantee the global generalised exponential stability of closed-loop systems. Simulation examples are given to verify the effectiveness of the developed control approach.

  12. Arm-length stabilisation for interferometric gravitational-wave detectors using frequency-doubled auxiliary lasers.

    Science.gov (United States)

    Mullavey, Adam J; Slagmolen, Bram J J; Miller, John; Evans, Matthew; Fritschel, Peter; Sigg, Daniel; Waldman, Sam J; Shaddock, Daniel A; McClelland, David E

    2012-01-02

    Residual motion of the arm cavity mirrors is expected to prove one of the principal impediments to systematic lock acquisition in advanced gravitational-wave interferometers. We present a technique which overcomes this problem by employing auxiliary lasers at twice the fundamental measurement frequency to pre-stabilise the arm cavities' lengths. Applying this approach, we reduce the apparent length noise of a 1.3 m long, independently suspended Fabry-Perot cavity to 30 pm rms and successfully transfer longitudinal control of the system from the auxiliary laser to the measurement laser.

  13. Arm-length stabilisation for interferometric gravitational-wave detectors using frequency-doubled auxiliary lasers

    CERN Document Server

    Mullavey, Adam J; Miller, John; Evans, Matthew; Fritschel, Peter; Sigg, Daniel; Waldman, Sam J; Shaddock, Daniel A; McClelland, David E

    2011-01-01

    Residual motion of the arm cavity mirrors is expected to prove one of the principal impediments to systematic lock acquisition in advanced gravitational-wave interferometers. We present a technique which overcomes this problem by employing auxiliary lasers at twice the fundamental measurement frequency to pre-stabilise the arm cavities' lengths. Applying this approach, we reduce the apparent length noise of a 1.3 m long, independently suspended Fabry-Perot cavity to 30 pm rms and successfully transfer longitudinal control of the system from the auxiliary laser to the measurement laser.

  14. A 10-year follow-up of transpedicular screw fixation and intervertebral autogenous posterior iliac crest bone graft or intervertebral B-Twin system in failed back surgery syndrome

    Science.gov (United States)

    Cincu, Rafael; Lorente, Francisco de Asis; Gomez, Joaquin; Eiras, Jose; Agrawal, Amit

    2015-01-01

    Background: The spine surgeons have been combining anterior and posterolateral fusion (circumferential fusion) as the final solution to treat spinal disorders and many have been using it to treat failed back surgery syndrome (FBSS). In present study, we analyzed and compared the clinical and radiological outcomes in patients with transpedicular screw fixation and intervertebral autogenous posterior iliac crest bone graft or in patients with transpedicular screw fixation and intervertebral B-Twin system for FBSS with a follow-up period of 10 years after the surgery. Materials and Methods: This study was a retrospective case study performed on 55 patients with FBSS. Clinical and radiological changes were compared between the two groups of patients on the basis of improvement of back pain, radicular pain, and work capacity. Outcome was measured in terms of Oswestry Low Back Pain Disability Index, and the changes in pain and function were documented every year from before surgery until 2012. We analyzed the evolution of 55 cases of FBSS those underwent segmental circumferential posterior fusions from June 2001 to February 2003, operated by a single surgeon and followed up during 10 years until February 2012. The patients were divided into 2 groups: In 25 patients, posterolateral fusions with Legacy™ (Medtronic, Inc. NYSE: MDT) screws and intersomatic autogenous posterior iliac crest bone graft was performed, and, in 30 patients, posterolateral fusions with the same screws and intersomatic fusion B-Twin (Biomet Spain Orthopaedics, S.L.) system was performed. In all cases, we used posterior lumbar interbody fusion (PLIF)/transforaminal lumbar interbody fusion (TLIF) approach for intervertebral graft, and the artrodesis was supplemented at intertransverse level with Autologus Growth Factor (AGF-MBA INCORPORADO, S.A.). The outcome was measured in terms of Oswestry Low Back Pain Disability Index, and the changes in pain and function were documented every year and compared

  15. A 10-year follow-up of transpedicular screw fixation and intervertebral autogenous posterior iliac crest bone graft or intervertebral B-Twin system in failed back surgery syndrome.

    Science.gov (United States)

    Cincu, Rafael; Lorente, Francisco de Asis; Gomez, Joaquin; Eiras, Jose; Agrawal, Amit

    2015-01-01

    The spine surgeons have been combining anterior and posterolateral fusion (circumferential fusion) as the final solution to treat spinal disorders and many have been using it to treat failed back surgery syndrome (FBSS). In present study, we analyzed and compared the clinical and radiological outcomes in patients with transpedicular screw fixation and intervertebral autogenous posterior iliac crest bone graft or in patients with transpedicular screw fixation and intervertebral B-Twin system for FBSS with a follow-up period of 10 years after the surgery. This study was a retrospective case study performed on 55 patients with FBSS. Clinical and radiological changes were compared between the two groups of patients on the basis of improvement of back pain, radicular pain, and work capacity. Outcome was measured in terms of Oswestry Low Back Pain Disability Index, and the changes in pain and function were documented every year from before surgery until 2012. We analyzed the evolution of 55 cases of FBSS those underwent segmental circumferential posterior fusions from June 2001 to February 2003, operated by a single surgeon and followed up during 10 years until February 2012. The patients were divided into 2 groups: In 25 patients, posterolateral fusions with Legacy™ (Medtronic, Inc. NYSE: MDT) screws and intersomatic autogenous posterior iliac crest bone graft was performed, and, in 30 patients, posterolateral fusions with the same screws and intersomatic fusion B-Twin (Biomet Spain Orthopaedics, S.L.) system was performed. In all cases, we used posterior lumbar interbody fusion (PLIF)/transforaminal lumbar interbody fusion (TLIF) approach for intervertebral graft, and the artrodesis was supplemented at intertransverse level with Autologus Growth Factor (AGF-MBA INCORPORADO, S.A.). The outcome was measured in terms of Oswestry Low Back Pain Disability Index, and the changes in pain and function were documented every year and compared from before surgery to the final

  16. Study of the electronics architecture for the mechanical stabilisation of the quadrupoles of the CLIC linear accelerator

    CERN Document Server

    Artoos, K; Fernandez Carmona, P; Guinchard, M; Hauviller, C; Janssens, S; Kuzmin, A; Slaathaug, A

    2010-01-01

    To reach a sufficient luminosity, the transverse beam sizes and emittances in future linear particle accelerators should be reduced to the nanometer level. Mechanical stabilisation of the quadrupole magnets is of the utmost importance for this. The piezo actuators used for this purpose can also be used to make fast incremental orientation adjustments with a nanometer resolution. The main requirements for the CLIC stabilisation electronics is a robust, low noise, low delay, high accuracy and resolution, low band and radiation resistant feedback control loop. Due to the high number of controllers (about 4000) a cost optimization should also be made. Different architectures are evaluated for a magnet stabilisation prototype, including the sensors type and configuration, partition between software and hardware for control algorithms, and optimization of the ADC/DAC converters. The controllers will be distributed along the 50 km long accelerator and a communication bus should allow external control. Furthermore, o...

  17. On asymptotic stabilisation of a chain of integrators with nonlinearity and an uncertain input delay by output feedback

    Science.gov (United States)

    Choi, Ho-Lim

    2014-12-01

    In this paper, we provide an output feedback solution over one given by Choi and Lim [Systems & Control Letters, 59(6), 374-379 (2010)] under more generalised system set-up. More specifically, we consider a stabilisation problem of a chain of integrators that has nonlinearity and an uncertain delay in the input by output feedback. The nonlinearity is classified into four types. Then, we propose a memoryless output feedback controller which contains a gain-scaling factor to adjust controller gains depending on the given nonlinearity type. Our stability analysis shows that the controlled system has unique stabilisation result associated with each type of nonlinearity. Our result provides a new aspect to the stabilisation problem of nonlinear time-delay systems and broadens the existing control results of time-delay systems. Two examples are given for illustration.

  18. Carbon nanoparticle stabilised liquid|liquid micro-interfaces for electrochemically driven ion-transfer processes

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, Stuart M. [Department of Chemistry, University of Bath, Bath BA2 7AY (United Kingdom); Fletcher, Paul D.I.; Cui Zhenggang [Department of Physical Sciences, Chemistry and Physics, University of Hull, Hull HU6 7RX (United Kingdom); Opallo, Marcin [Institute of Physical Chemistry, Polish Academy of Sciences, ul. Kasprzaka 44/52, 01-224 Warsaw (Poland); Chen Jingyuan [Department of Applied Physics, University of Fukui, 3-9-1, Bunkyo, Fukui-shi 910-8507 (Japan); Marken, Frank [Department of Chemistry, University of Bath, Bath BA2 7AY (United Kingdom)], E-mail: F.Marken@bath.ac.uk

    2007-12-20

    Stabilised liquid|liquid interfaces between an organic 4-(3-phenylpropyl)-pyridine (PPP) phase and an aqueous electrolyte phase are obtained in the presence of suitable nanoparticles. The use of nanoparticulate stabilisers (ca. 30 nm diameter laponite or 9-18 nm diameter carbon) in 'Pickering' emulsion systems allows stable organic microdroplets to be formed and these are readily deposited onto conventional tin-doped indium oxide (ITO) electrodes. In contrast to the electrically insulating laponite nanoparticles, conducting carbon nanoparticles are shown to effectively catalyse the simultaneous electron transfer and ion transfer process at triple phase boundary junctions. Anion transfer processes between the aqueous and organic phase are driven electrochemically at the extensive triple phase junction carbon nanoparticle|4-(3-phenylpropyl)-pyridine|aqueous electrolyte. The organic phase consists of a redox active reagent 5,10,15,20-tetraphenyl-21H,23H-porphinato manganese(III) (MnTPP{sup +}), 5,10,15,20-tetraphenyl-21H,23H-porphinato iron(III) (FeTPP{sup +}), or proto-porphyrinato-IX iron(III) (hemin) dissolved in 4-(3-phenylpropyl)-pyridine (PPP). The composition of the aqueous electrolyte phase determines the reversible potential for the Nernstian anion transfer process. The methodology is shown to be versatile and, in future, could be applied more generally in liquid|liquid electroanalysis.

  19. Quantum cascade laser frequency stabilisation at the sub-Hz level

    CERN Document Server

    Argence, Bérengère; Lopez, Olivier; Nicolodi, Daniele; Abgrall, Michel; Chardonnet, Christian; Daussy, Christophe; Darquié, Benoît; Coq, Yann Le; Amy-Klein, Anne

    2014-01-01

    Quantum Cascade Lasers (QCL) are increasingly being used to probe the mid-infrared "molecular fingerprint" region. This prompted efforts towards improving their spectral performance, in order to reach ever-higher resolution and precision. Here, we report the stabilisation of a QCL onto an optical frequency comb. We demonstrate a relative stability and accuracy of 2x10-15 and 10-14, respectively. The comb is stabilised to a remote near-infrared ultra-stable laser referenced to frequency primary standards, whose signal is transferred via an optical fibre link. The stability and frequency traceability of our QCL exceed those demonstrated so far by two orders of magnitude. As a demonstration of its capability, we then use it to perform high-resolution molecular spectroscopy. We measure absorption frequencies with an 8x10-13 relative uncertainty. This confirms the potential of this setup for ultra-high precision measurements with molecules, such as our ongoing effort towards testing the parity symmetry by probing ...

  20. Effects of agrochemicals, ultra violet stabilisers and solar radiation on the radiometric properties of greenhouse films

    Directory of Open Access Journals (Sweden)

    Giuliano Vox

    2013-10-01

    Full Text Available Agrochemicals, based on iron, sulphur and chlorine, generate by products that lead to a degradation of greenhouse films together with a decrease in their mechanical and physical properties. The degradation due to agrochemicals depends on their active principles, method and frequency of application, and greenhouse ventilation. The aim of the research was to evaluate how agrochemical contamination and solar radiation influence the radiometric properties of ethylene-vinyl acetate copolymer greenhouse films by means of laboratory and field tests. The films, manufactured on purpose with the addition of different light stabiliser systems, were exposed to natural outdoor weathering at the experimental farm of the University of Bari (Italy; 41° 05’ N in the period from 2006 to 2008. Each film was tested for two low tunnels: one low tunnel was sprayed from inside with the agrochemicals containing iron, chlorine and sulphur while the other one was not sprayed and served as control. Radiometric laboratory tests were carried out on the new films and on samples taken at the end of the trials. The experimental tests showed that both the natural weathering together with the agrochemicals did not modify significantly the radiometric properties of the films in the solar and in the photosynthetically active radiation wavelength range. Within six months of experimental field tests the variations in these radiometric characteristics were at most 10%. Significant variations, up to 70% of the initial value, were recorded for the stabilised films in the long-wave infrared radiation wavelength range.

  1. Influence of Geosta Addition on Cement-stabilised Chicoco Mud of the Niger Delta

    Directory of Open Access Journals (Sweden)

    Olujide Omotosho

    2005-01-01

    Full Text Available Chicoco is a very soft and extremely compressible organic marine mud found extensively and to considerable depths within the saline tidal flat or mangrove swamp of the Niger delta in southern Nigeria. Natural chicoco is highly undesirable, barely able to support a human of average weight but air-dried chicoco has been used successfully by the indigeneous people for shore protection, etc. especially if placed above water. Plain cement stabilization of most organic soils (including chicoco is known to be ineffective. In this study, geosta, a chemical stabiliser relatively newly developed for organic soils was combined with ordinary Portland cement to stabilise chicoco. It was observed that neutralisation of acidic "air-dried" chicoco by basic geosta inhibited the expected ion-exchange reaction and its attendant improvement on mechanical properties. As a result and as geosta content increases, maximum dry density (MDD was found to be only marginally improved but better for higher cement contents while optimum moisture content (OMC decreases but with higher values for lower cement contents. Unsoaked CBR (but with samples wax-cured for 3 days on the other hand was found to maximise at low geosta content and thereafter decreases continually - a major cost advantage in earthworks. In fact, the most effective influence was obtained at 4.0% cement plus about 1.5% geosta. This stabilization was also found to produce optimum road sub-base materials.

  2. Metastable SUSY Breaking, de Sitter Moduli Stabilisation and Kähler Moduli Inflation

    CERN Document Server

    Krippendorf, Sven

    2009-01-01

    We study the influence of anomalous U(1) symmetries and their associated D-terms on the vacuum structure of global field theories once they are coupled to N=1 supergravity and in the context of string compactifications with moduli stabilisation. In particular, we focus on a IIB string motivated construction of the ISS scenario and examine the influence of one additional U(1) symmetry on the vacuum structure. We point out that in the simplest one-Kahler modulus compactification, the original ISS vacuum gets generically destabilised by a runaway behaviour of the potential in the modulus direction. In more general compactifications with several Kahler moduli, we find a novel realisation of the LARGE volume scenario with D-term uplifting to de Sitter space and both D-term and F-term supersymmetry breaking. The structure of soft supersymmetry breaking terms is determined in the preferred scenario where the standard model cycle is not stabilised non-perturbatively and found to be flavour universal. Our scenario als...

  3. En route vers la nano stabilisation de CLIC faisceau principale et focalisation finale

    CERN Document Server

    Artoos, K; Guinchard, M; Hauviller, Claude; Lackner, F; CERN. Geneva. TS Department

    2008-01-01

    Pour atteindre la luminosité voulue de CLIC, la taille transversale du faisceau doit être de l?ordre du nanomètre. Ceci nécessite une stabilité vibratoire des quadripôles du faisceau principal de 1 nm et même 0.1 nm pour les doublets de la focalisation finale. La nano technologie et la nano stabilisation sont des activités qui évoluent rapidement dans l?industrie et centres de recherche pour des applications très variées comme l?électronique, l?optique, la chimie voire la médecine. Cette présentation décrit les avancées techniques nécessaires pour atteindre l?objectif de CLIC et les projets et collaborations R&D prévus pour démontrer la faisabilité de la nano stabilisation de CLIC en 2010.

  4. Alleviation of Soil Acidity and Aluminium Phytotoxicity in Acid Soils by Using Alkaline-Stabilised Biosolids

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A pot experiment was carried out to study alleviation of soil acidity and Al toxicity by applying an alkaline-stabilised sewage sludge product (biosolids) to an acid clay sandy loam (pH 5.7) and a strongly acid sandy loam (pH 4.5). Barley (Hordeum vulgare L. cv. Forrester) was used as a test crop and was grown in the sewage sludge-amended (33.5 t sludge DM ha-1) and unamended soils. The results showed that the alkaline biosloids increased soil pH from 5.7 to 6.9 for the clay sandy loam and from 4.5 to 6.0 for the sandy loam. The sludge product decreased KCl-extractable Al from 0.1 to 0.0 cmol kg-1 for the former soil and from 4.0 to 0.1 cmol kg-1 for the latter soil. As a result, barley plants grew much better and grain yield increased greatly in the amended treatments compared with the unamended controls. These observations indicate that alkaline-stabilised biosolids can be used as a liming material for remedying Al phytotoxicity in strongly acid soils by increasing soil pH and lowering Al bioavailability.

  5. Characterisation of Physicochemical Properties of Propionylated Corn Starch and Its Application as Stabiliser

    Directory of Open Access Journals (Sweden)

    Lee-Fen Hong

    2015-01-01

    Full Text Available A series of propionylated starches with diff erent degrees of substitution (DS was synthesised and their physicochemical properties and application as a stabiliser were investigated. Starch propionates with moderate DS were prepared by esterifi cation of native corn starch with propionic anhydride. By varying the reaction times of the esterification process, twelve starch propionates with DS of 0.47 to 0.94 were prepared. FTIR and NMR confirmed the introduction of propionyl groups to the starch. X-ray diffraction pattern showed reduced crystallinity in the starch propionates. The contact angle was found to increase proportionately with the increase in DS. Swelling power results showed that starch propionates were able to swell more than native corn starch at low temperature (40°C. Oil-in-water (O/W emulsions prepared using starch propionates (DS of 0.64 to 0.86 showed exceptional stability when challenged by centrifugation stress test. These stable O/W emulsions had viscosities in the range of 1236.7–3330.0 mPa·s. In conclusion, moderately substituted short-chain (propionylated starches could be a promising cold swelling starch, thickener and O/W emulsion stabiliser in food, pharmaceutical and cosmetic industries.

  6. Dry oil powders and oil foams stabilised by fluorinated clay platelet particles.

    Science.gov (United States)

    Binks, Bernard P; Sekine, Tomoko; Tyowua, Andrew T

    2014-01-28

    A series of platelet sericite particles coated to different extents with a fluorinating agent has been characterised and their behaviour in mixtures with air and oil studied. The material which forms by vigorous shaking depends on both the surface tension of the oil and the surface energy of the particles which control their degree of wetting. Oil dispersions are formed in liquids of relatively low tension (cyclomethicone, for all particles. Particle-stabilised air-in-oil foams form in liquids of higher tension, e.g. dodecane and phenyl silicone, where the advancing three-phase contact angle θ, measured on a planar substrate composed of the particles into the liquid, lies between ca. 65° and 120°. For oils of tension above 27 mN m(-1) like squalane and liquid paraffin with particles for which θ > 70°, we have discovered that dry oil powders in which oil drops stabilised by particles dispersed in air (oil-in-air) can be prepared by gentle mixing up to a critical oil : particle ratio (COPR) and do not leak oil. These powders, containing up to 80 wt% oil, release the encapsulated oil when sheared on a substrate. For many of the systems forming oil powders, stable liquid oil marbles can also be prepared. Above the COPR, catastrophic phase inversion occurs yielding an ultra-stable air-in-oil foam. We thus demonstrate the ability to disperse oil drops or air bubbles coated with particles within novel materials.

  7. Lipid oxidation in minced beef meat with added Krebs cycle substrates to stabilise colour.

    Science.gov (United States)

    Yi, G; Grabež, V; Bjelanovic, M; Slinde, E; Olsen, K; Langsrud, O; Phung, V T; Haug, A; Oostindjer, M; Egelandsdal, B

    2015-11-15

    Krebs cycle substrates (KCS) can stabilise the colour of packaged meat by oxygen reduction. This study tested whether this reduction releases reactive oxygen species that may lead to lipid oxidation in minced meat under two different storage conditions. KCS combinations of succinate and glutamate increased peroxide forming potential (PFP, 1.18-1.32 mmol peroxides/kg mince) and thiobarbituric acid reactive substances (TBARS, 0.30-0.38 mg malondialdehyde (MDA) equivalents/kg mince) under low oxygen storage conditions. Both succinate and glutamate were metabolised. Moreover, under high oxygen (75%) storage conditions, KCS combinations of glutamate, citrate and malate increased PFP (from 1.22 to 1.29 mmol peroxides/kg) and TBARS (from 0.37 to 0.40 mg MDA equivalents/kg mince). Only glutamate was metabolised. The KCS combinations that were added to stabilise colour were metabolised during storage, and acted as pro-oxidants that promoted lipid oxidation in both high and low oxygen conditions.

  8. Hydraulic retention time on vinasse stabilisation with limestone in the acidogenic phase of anaerobic digestion

    Directory of Open Access Journals (Sweden)

    Ismael Plácido Tomielis

    Full Text Available ABSTRACT: The main problem in anaerobic digestion of low-protein residues is the instability caused acidity. The use of limestone at the same time as a neutralizing agent and support material is innovative because stones wear allows the slow release of the calcium carbonate thereby eliminating dispersers. Free calcium content in the system was measured in two plug flow reactors filled with vinasse at initial pH of 4.50. The proportion of 1.8 tonnes of limestone per m³ of vinasse was evaluated at the Hydraulic Retention Times (HRT of 24, 48, 72, 96 and 120 hours, allowing stabilisation at 96 hours. The ratio of Volatile Acids/Total Alkalinity (VA/TA ranged from 0.2 to 0.4 and the pH reached 7.0, at the HRT of 120 hours. Increasing the HRT also increased the volatile total solids (VTS and fixed total solids (TFS in a similar profile to the measured free calcium content, but calcium remained at the appropriate level of 100 to 250mg l-1. The proportion of limestone/vinasse was adequate to ensure stabilisation, but it is not recommended to reduce the HRT below 96 hours due to the risk of compromising the stability of the anaerobic system.

  9. Chemistry of guanidinate-stabilised diboranes: transition-metal-catalysed dehydrocoupling and hydride abstraction.

    Science.gov (United States)

    Wagner, Arne; Litters, Sebastian; Elias, Jana; Kaifer, Elisabeth; Himmel, Hans-Jörg

    2014-09-22

    Herein, we analyse the catalytic boron-boron dehydrocoupling reaction that leads from the base-stabilised diborane(6) [H2 B(hpp)]2 (hpp=1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidinate) to the base-stabilised diborane(4) [H2 B(hpp)]2 . A number of potential transition-metal precatalysts was studied, including transition-metal complexes of the product diborane(4). The synthesis and structural characterisation of two further examples of such complexes is presented. The best results for the dehydrocoupling reactions were obtained with precatalysts of Group 9 metals in the oxidation state of +I. The active catalyst is formed in situ through a multistep process that involves reduction of the precatalyst by the substrate [H2 B(hpp)]2 , and mechanistic investigations indicate that both heterogeneous and (slower) homogeneous reaction pathways play a role in the dehydrocoupling reaction. In addition, hydride abstraction from [H2 B(hpp)]2 and related diboranes is analysed and the possibility for subsequent deprotonation is discussed by probing the protic character of the cationic boron-hydrogen compounds with NMR spectroscopic analysis.

  10. The effect of environmental conditions and soil physicochemistry on phosphate stabilisation of Pb in shooting range soils.

    Science.gov (United States)

    Sanderson, Peter; Naidu, Ravi; Bolan, Nanthi

    2016-04-01

    The stabilisation of Pb in the soil by phosphate is influenced by environmental conditions and physicochemical properties of the soils to which it is applied. Stabilisation of Pb by phosphate was examined in four soils under different environmental conditions. The effect of soil moisture and temperature on stabilisation of Pb by phosphate was examined by measurement of water extractable and bioaccessible Pb, sequential fractionation and X-ray absorption spectroscopy. The addition of humic acid, ammonium nitrate and chloride was also examined for inhibition or improvement of Pb stability with phosphate treatment. The effect of moisture level varied between soils. In soil MB and DA a soil moisture level of 50% water holding capacity was sufficient to maximise stabilisation of Pb, but in soil TV and PE reduction in bioaccessible Pb was inhibited at this moisture level. Providing moisture at twice the soil water holding capacity did not enhance the effect of phosphate on Pb stabilisation. The difference of Pb stability as a result of incubating phosphate treated soils at 18 °C and 37 °C was relatively small. However wet-dry cycles decreased the effectiveness of phosphate treatment. The reduction in bioaccessible Pb obtained was between 20 and 40% with the most optimal treatment conditions. The reduction in water extractable Pb by phosphate was substantial regardless of incubation conditions and the effect of different temperature and soil moisture regimes was not significant. Selective sequential extraction showed phosphate treatment converted Pb in fraction 1 (exchangeable, acid and water soluble) to fraction 2 (reducible). There were small difference in fraction 4 (residual) Pb and fraction 1 as a result of treatment conditions. X-ray absorption spectroscopy of stabilised PE soil revealed small differences in Pb speciation under varying soil moisture and temperature treatments. The addition of humic acid and chloride produced the greatest effect on Pb speciation in

  11. 腰椎椎弓根楔形截骨术治疗强直性脊柱炎后凸畸形%Transpedicular lumbar wedge resection osteotomy for correction of kyphosis in ankyiosing spondylitis

    Institute of Scientific and Technical Information of China (English)

    范建平; 王传锋; 朱晓东; 陈家瑜; 李超; 陈超; 梁楠; 白玉树; 李明

    2013-01-01

    目的 探讨腰椎椎弓根楔形截骨术治疗强直性脊柱炎后凸畸形的临床疗效.方法 2005年1月至2010年3月,第二军医大学长海医院骨科共收治32例强直性脊柱炎后凸畸形患者,均行一期后路经腰椎椎弓根楔形截骨矫形内固定术.其中27例患者行单节段椎弓根楔形截骨术,5例患者行双节段椎弓根截骨术.术前及术后随访时拍摄脊柱全长X线片,测量影像学参数,并填写中文版脊柱侧凸研究学会22项(SRS-22)量表进行患者的健康生存质量评价.结果 手术时间平均为(260±42) min,术中出血平均(1 360±282) mL,平均随访(31±8)个月(24~76个月),均未出现神经系统并发症及假关节.患者颌眉角、全脊柱后凸角、胸腰段后凸角、腰椎前凸角由术前(65.9±11.6)°、(78.2±15.9)°、(38.9±10.3)°、(14.6±17.3)°分别矫正至术后(11.7±4.7)°、(38.9±10.3)°、(1.3±7.8)°、(26.2±5.6)°;身高和矢状面失平衡距离由术前的(135.4±15.2) cm、(37.2±11.3) cm分别矫正至术后的(166.2±9.6) cm、(12.7±7.7) cm,差异均有统计学意义(P<0.01).SRS-22评分由术前平均(1.8±0.4)改善至术后(4.0±0.6),疗效满意.结论 腰椎椎弓根楔形截骨术治疗强直性脊柱炎后凸畸形安全可靠,可获得满意的临床效果.%Objective To explore the clinical efficacies of transpedicular lumbar wedge resection osteotomy for correction of kyphosis in ankylosing spondylitis. Methods From January 2005 to March 2010,32 patients with ankylosing spondylitis kyphotic deformity received one stage posterior transpedicular wedge osteotomy and internal fixation, with 27 receiving single-level ones and 5 receiving two-level ones. All patients underwent X ray examination of the total spine to obtain radiographic parameters and were asked to accomplish simplified Chinese scoliosis research society-22 (SRS-22) questionnaire to assess quality of health before and after operation. Results The mean operation time

  12. The use of biogas plant fermentation residue for the stabilisation of toxic metals in agricultural soils

    Science.gov (United States)

    Geršl, Milan; Šotnar, Martin; Mareček, Jan; Vítěz, Tomáš; Koutný, Tomáš; Kleinová, Jana

    2015-04-01

    Our department has been paying attention to different methods of soil decontamination, including the in situ stabilisation. Possible reagents to control the toxic metals mobility in soils include a fermentation residue (FR) from a biogas plant. Referred to as digestate, it is a product of anaerobic decomposition taking place in such facilities. The fermentation residue is applied to soils as a fertiliser. A new way of its use is the in situ stabilisation of toxic metals in soils. Testing the stabilisation of toxic metals made use of real soil samples sourced from five agriculturally used areas of the Czech Republic with 3 soil samples taken from sites contaminated with Cu, Pb and Zn and 2 samples collected at sites of natural occurrence of Cu, Pb and Zn ores. All the samples were analysed using the sequential extraction procedure (BCR) (determine the type of Cu, Pb and Zn bonds). Stabilisation of toxic metals was tested in five soil samples by adding reagents as follows: dolomite, slaked lime, goethite, compost and fermentation residue. A single reagent was added at three different concentrations. In the wet state with the added reagents, the samples were left for seven days, shaken twice per day. After seven days, metal extraction was carried out: samples of 10 g soil were shaken for 2 h in a solution of 0.1M NH4NO3 at a 1:2.5 (g.ml-1), centrifuged for 15 min at 5,000 rpm and then filtered through PTFE 0.45 μm mesh filters. The extracts were analysed by ICP-OES. Copper The best reduction of Cu concentration in the extract was obtained at each of the tested sites by adding dolomite (10 g soil + 0.3 g dolomite). The concentration of Cu in the leachate decreased to 2.1-18.4% compare with the leachate without addition. Similar results were also shown for the addition of fermentation residue (10 g soil + 1 g FR). The Cu concentration in the leachate decreased to 16.7-26.8% compared with the leachate without addition. Lead The best results were achieved by adding

  13. Freshwater dispersion stability of PAA-stabilised cerium oxide nanoparticles and toxicity towards Pseudokirchneriella subcapitata

    Energy Technology Data Exchange (ETDEWEB)

    Booth, Andy, E-mail: andy.booth@sintef.no [SINTEF Materials and Chemistry, Trondheim N-7465 (Norway); Størseth, Trond [SINTEF Materials and Chemistry, Trondheim N-7465 (Norway); Altin, Dag [BioTrix, Trondheim N-7022 (Norway); Fornara, Andrea; Ahniyaz, Anwar [German Federal Institute for Risk Assessment (BfR), Department of Product Safety, Berlin (Germany); Jungnickel, Harald; Laux, Peter; Luch, Andreas [SP Chemistry, Materials and Surfaces, Drottning Kristinas vag 45, SE-11686 Stockholm (Sweden); Sørensen, Lisbet [SINTEF Materials and Chemistry, Trondheim N-7465 (Norway)

    2015-02-01

    An aqueous dispersion of poly (acrylic acid)-stabilised cerium oxide (CeO{sub 2}) nanoparticles (PAA-CeO{sub 2}) was evaluated for its stability in a range of freshwater ecotoxicity media (MHRW, TG 201 and M7), with and without natural organic matter (NOM). In a 15 day dispersion stability study, PAA-CeO{sub 2} did not undergo significant aggregation in any media type. Zeta potential varied between media types and was influenced by PAA-CeO{sub 2} concentration, but remained constant over 15 days. NOM had no influence on PAA-CeO{sub 2} aggregation or zeta potential. The ecotoxicity of the PAA-CeO{sub 2} dispersion was investigated in 72 h algal growth inhibition tests using the freshwater microalgae Pseudokirchneriella subcapitata. PAA-CeO{sub 2} EC{sub 50} values for growth inhibition (GI; 0.024 mg/L) were 2–3 orders of magnitude lower than pristine CeO{sub 2} EC{sub 50} values reported in the literature. The concentration of dissolved cerium (Ce{sup 3+}/Ce{sup 4+}) in PAA-CeO{sub 2} exposure suspensions was very low, ranging between 0.5 and 5.6 μg/L. Free PAA concentration in the exposure solutions (0.0096–0.0384 mg/L) was significantly lower than the EC{sub 10} growth inhibition (47.7 mg/L) value of pure PAA, indicating that free PAA did not contribute to the observed toxicity. Elemental analysis indicated that up to 38% of the total Cerium becomes directly associated with the algal cells during the 72 h exposure. TOF-SIMS analysis of algal cell wall compounds indicated three different modes of action, including a significant oxidative stress response to PAA-CeO{sub 2} exposure. In contrast to pristine CeO{sub 2} nanoparticles, which rapidly aggregate in standard ecotoxicity media, PAA-stabilised CeO{sub 2} nanoparticles remain dispersed and available to water column species. Interaction of PAA with cell wall components, which could be responsible for the observed biomarker alterations, could not be excluded. This study indicates that the increased

  14. Novel solid – solid phase change material based on polyethylene glycol and cellulose used for temperature stabilisation

    Directory of Open Access Journals (Sweden)

    Wojda Marta

    2014-01-01

    Full Text Available Thermal management is one of crucial issues in the development of modern electronic devices. In the recent years interest in phase change materials (PCMs as alternative cooling possibility has increased significantly. Preliminary results concerning the research into possibility of the use of solid-solid phase change materials (S-S PCMs for stabilisation temperature of electronic devices has been presented in the paper. Novel solid-solid phase change material based on polyethylene glycol and cellulose has been synthesized. Attempt to improve its thermal conductivity has been taken. Material has been synthesized for the purpose of stabilisation of temperature of electronic devices.

  15. Anisotropic modulus stabilisation. Strings at LHC scales with micron-sized extra dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Cicoli, M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Burgess, C.P. [McMaster Univ., Hamilton (Canada). Dept. of Physics and Astronomy; Perimeter Institute for Theoretical Physics, Waterloo (Canada); Quevedo, F. [Cambridge Univ. (United Kingdom). DAMTP/CMS; Abdus Salam International Centre for Theoretical Physics, Trieste (Italy)

    2011-04-15

    We construct flux-stabilised Type IIB string compactifications whose extra dimensions have very different sizes, and use these to describe several types of vacua with a TeV string scale. Because we can access regimes where two dimensions are hierarchically larger than the other four, we find examples where two dimensions are micron-sized while the other four are at the weak scale in addition to more standard examples with all six extra dimensions equally large. Besides providing ultraviolet completeness, the phenomenology of these models is richer than vanilla large-dimensional models in several generic ways: (i) they are supersymmetric, with supersymmetry broken at sub-eV scales in the bulk but only nonlinearly realised in the Standard Model sector, leading to no MSSM superpartners for ordinary particles and many more bulk missing-energy channels, as in supersymmetric large extra dimensions (SLED); (ii) small cycles in the more complicated extra-dimensional geometry allow some KK states to reside at TeV scales even if all six extra dimensions are nominally much larger; (iii) a rich spectrum of string and KK states at TeV scales; and (iv) an equally rich spectrum of very light moduli exist having unusually small (but technically natural) masses, with potentially interesting implications for cosmology and astrophysics that nonetheless evade new-force constraints. The hierarchy problem is solved in these models because the extra-dimensional volume is naturally stabilised at exponentially large values: the extra dimensions are Calabi-Yau geometries with a 4D K3-fibration over a 2D base, with moduli stabilised within the well-established LARGE-Volume scenario. The new technical step is the use of poly-instanton corrections to the superpotential (which, unlike for simpler models, are present on K3-fibered Calabi-Yau compactifications) to obtain a large hierarchy between the sizes of different dimensions. For several scenarios we identify the low-energy spectrum and

  16. The mast cell stabiliser ketotifen decreases visceral hypersensitivity and improves intestinal symptoms in patients with irritable bowel syndrome

    NARCIS (Netherlands)

    Klooker, Tamira K.; Braak, Breg; Koopman, Karin E.; Welting, Olaf; Wouters, Mira M.; van der Heide, Sicco; Schemann, Michael; Bischoff, Stephan C.; van den Wijngaard, Rene M.; Boeckxstaens, Guy E.

    2010-01-01

    Background Mast cell activation is thought to be involved in visceral hypersensitivity, one of the main characteristics of the irritable bowel syndrome (IBS). A study was therefore undertaken to investigate the effect of the mast cell stabiliser ketotifen on rectal sensitivity and symptoms in patien

  17. In-situ stabilisation followed by ex-situ composting for treatment and disposal of heavy metals polluted sediments

    Institute of Scientific and Technical Information of China (English)

    YU Guangwei; LEI Hengyi; BAI Tao; LI Zhong; YU Qiang; SONG Xianqiang

    2009-01-01

    An innovative in-situ stabilisation treatment followed by ex-situ sediment composting was tested for its ability to treat and dispose of heavy-metal-polluted sediments in a river near the Chinese Pearl Delta. First, polluted sediments were treated in-situ to stabilise the heavy metals. Then the treated sediments were dredged, dewatered and sent for high temperature aerobic composting (HTAC) treatment. Finally, the compost products were used as a fertiliser for river bank plants. The stabilisation efficiency of heavy metals during the process was investigated and the results are as follows: (1) using in-situ stabilisation, the extraction concentrations of Cu, Zn and Pb were reduced by 65.0%, 82.2% and 90.0%, respectively, which are much lower than the national standard given in the Identification Standard for Hazardous Waste (GB5085.3-1996); (2) chemical fraction analysis showed that heavy metals were further stabilized during the HTAC treatment; (3) the concentrations of Cu, Zn and Pb in rainwater ieachate through the river bank met the level of class V in the Environmental Quality Standards for Surface Water in China (GB3838-2002). Therefore, using this new process, the toxicities of heavy metals in sediments were reduced markedly.

  18. Exploitation of hazelnut, maize germ and sesame seed aqueous extraction residues in the stabilisation of sesame seed paste (tahini).

    Science.gov (United States)

    Evlogimenou, Anthi; Paraskevopoulou, Adamantini; Kiosseoglou, Vassilios

    2017-01-01

    Sesame seed paste is a highly nutritious food product which, upon long-term storage, tends to exhibit undesirable phenomena of oiling-off and particle sedimentation. The ability of rich-in-fibre aqueous extraction powders originating from oleaginous raw materials to enhance the physical stability of sesame paste is investigated in this study. The extraction residues remaining after treating hazelnut, sesame seed or maize germ with aqueous media in order to extract and exploit their oil bodies, were collected, dehydrated and milled into fine powders. The powders were then incorporated at various levels into a commercially available sesame paste product to assess their potential as paste stabilisers against oil separation. The solids from maize germ exhibited the highest stabilising ability followed by the solids from hazelnut. In contrast, the solids originating from the sesame seed were less effective in stabilising the sesame paste. Shear stress-rate of shear measurements of sesame paste incorporating the extraction residue solids were conducted in an attempt to explain the different stabilising behaviour of the three powders. The intensity of interactions between the incorporated solids within the sesame paste structure may determine the rheological properties of the blend and hence its stability against oiling-off upon long-term storage. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  19. Oil bodies as a potential microencapsulation carrier for astaxanthin stabilisation and safe delivery.

    Science.gov (United States)

    Acevedo, Francisca; Rubilar, Mónica; Jofré, Ignacio; Villarroel, Mario; Navarrete, Patricia; Esparza, Magdalena; Romero, Fernando; Vilches, Elías Alberto; Acevedo, Valentina; Shene, Carolina

    2014-01-01

    Astaxanthin (AST) is a valued molecule because of its high antioxidant properties. However, AST is extremely sensitive to oxidation, causing the loss of its bioactive properties. The purposes of this study were to define conditions for microencapsulating AST in oil bodies (OB) from Brassica napus to enhance its oxidative stability, and to test the bioactivity of the microencapsulated AST (AST-M) in cells. Conditions for maximising microencapsulation efficiency (ME) were determined using the Response Surface Methodology, obtaining a high ME (>99%). OB loaded with AST showed a strong electrostatic repulsion in a wide range of pH and ionic strengths. It was found that AST-M exposed to air and light was more stable than free AST. In addition, the protective effect of AST against intracellular ROS production was positively influenced by microencapsulation in OB. These results suggest that OB offer a novel option for stabilising and delivering AST.

  20. Stabilisation of bank slopes that are prone to liquefaction in ecologically sensitive areas.

    Science.gov (United States)

    Nestler, P; Stoll, R D

    2001-01-01

    A consequence of lignite stripping in the Lusatia mining district (East Germany) is the backfilling of dumps that mainly consist of low-compacted fine and medium-grained sands. When the ground-water table, which had been lowered while stripping the coal, is rising again, these dumps might be affected by a settlement flow due to the liquefaction of soils. Common methods for stabilisation as, for instance, blasting or vibrator-jetting deep compaction, are not very useful in ecologically sensitive areas, where dumps have been afforested and embankment areas of residual lakes have developed into highly valuable biotopes. A new so-called air-impulse method in combination with directional horizontal drilling has been developed, which does not have a considerably negative impact on the vegetation during compaction. The experience gained during the first employment of this method at the lake "Katja", a residual lake of lignite stripping, is presented in this paper.

  1. Robust PID based power system stabiliser: Design and real-time implementation

    Energy Technology Data Exchange (ETDEWEB)

    Bevrani, Hassan [Department of Electrical and Computer Eng., University of Kurdistan, Sanandaj (Iran, Islamic Republic of); Hiyama, Takashi [Department of Electrical and Computer Eng., Kumamoto University, Kumamoto (Japan); Bevrani, Hossein [Department of Statistics, University of Tabriz, Tabriz (Iran, Islamic Republic of)

    2011-02-15

    This paper addresses a new robust control strategy to synthesis of robust proportional-integral-derivative (PID) based power system stabilisers (PSS). The PID based PSS design problem is reduced to find an optimal gain vector via an H{infinity} static output feedback control (H{infinity}-SOF) technique, and the solution is easily carried out using a developed iterative linear matrix inequalities algorithm. To illustrate the developed approach, a real-time experiment has been performed for a longitudinal four-machine infinite-bus system using the Analog Power System Simulator at the Research Laboratory of the Kyushu Electric Power Company. The results of the proposed control strategy are compared with full-order H{infinity} and conventional PSS designs. The robust PSS is shown to maintain the robust performance and minimise the effect of disturbances properly. (author)

  2. Stabilisation of the amorphous state of a thin layer sandwiched between two crystals

    Energy Technology Data Exchange (ETDEWEB)

    Hyot, B.; Poupinet, L.; Desre, P.J

    2003-11-01

    It has been experimentally proven that thinning an amorphous layer, sandwiched between two crystals, up to the nanometer scale, leads to a higher crystallization temperature. The present work is an attempt to explain such behaviour on the basis of thermodynamical arguments. The approach assumes that a nanometric amorphous layer is submitted to the crystal field leading to a gradient of atomic density across the glassy layer. It is shown that the stabilisation of the glassy layer is expected when approaching a thickness of few nanometers. This study is closely related to the concerns of the phase change optical storage because such a technology involves both the use of very thin films and fast structural transitions between the two states (amorphous and crystalline) of the active material.

  3. Stabilisation of a fibre frequency synthesiser using acousto-optical and electro-optical modulators

    Science.gov (United States)

    Koliada, N. A.; Nyushkov, B. N.; Pivtsov, V. S.; Dychkov, A. S.; Farnosov, S. A.; Denisov, V. I.; Bagayev, S. N.

    2016-12-01

    A fibre-optic frequency synthesiser is developed that is stabilised to the optical frequency standard based on molecular iodine ({\\text{Nd : YAG/I}}2). The possibility of transferring stability of the optical frequency standard to other optical frequencies in the IR range 1 - 2 \\unicode{956}{\\text{m}} and to the RF range by using synthesiser phase-locked loops (PLLs) with acousto-optical and electro-optical modulators is experimentally demonstrated. The additive instability introduced into the optical frequency comb of the synthesiser (which arises due to PLL residual random errors) is several orders less than the intrinsic instability of the reference optical frequency standard employed (i.e., is noticeably less than 1 × 10-13 for 1 {\\text{s}} and 5 × 10-15 for 1000 {\\text{s}}).

  4. Remediation by in-situ solidification/stabilisation of Ardeer landfill, Scotland

    Energy Technology Data Exchange (ETDEWEB)

    Wyllie, M. [ICI Explosives, Ayrshire (United Kingdom); Esnault, A. [Bachy, Rueil-Malmaison (France); Barker, P. [Bachy, Surrey (United Kingdom)

    1997-12-31

    The Ardeer Landfill site at ICI Explosives factory on the west coast of Scotland had been a repository for waste from the site for 40 years. In order to safeguard the local environment ICI Explosives, with approval of Local Authorities and the Clyde River Purification Board put into action a programme of investigation and planning which culminated in the in-situ treatment of 10,000 m3 of waste within the landfill by a deep mixing method using the {open_quotes}Colmix{close_quotes} system. The paper describes in varying degrees of detail the remediation from investigation to the execution of the in-situ stabilisation and presents the post construction monitoring results.

  5. Hygrothermal analysis of a stabilised rammed earth test building in the UK

    Energy Technology Data Exchange (ETDEWEB)

    Allinson, David [Department of Civil and Building Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom); Hall, Matthew [Nottingham Centre for Geomechanics, Division of Materials, Mechanics and Structures, Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)

    2010-06-15

    This paper describes the analysis of the hygrothermal behaviours of stabilised rammed earth (SRE) walls used in a building in the UK. The analysis was achieved by computer simulation using WUFI Plus v1.2 whole building hygrothermal analysis software. To validate the model, an unoccupied test room in an unheated SRE building was monitored for 10 months. The hygrothermal properties of the SRE material were measured in the laboratory. It is shown that the SRE walls significantly reduced the amplitude of relative humidity fluctuations in the room air and reduced the frequency of high humidity periods at the wall surface. By adapting the model to represent an occupied and conditioned space, it is demonstrated that SRE walls have the potential to reduce the energy demand for humidification/dehumidification plant. (author)

  6. Input-output finite-time stabilisation of nonlinear stochastic system with missing measurements

    Science.gov (United States)

    Song, Jun; Niu, Yugang; Jia, Tinggang

    2016-09-01

    This paper considers the problem of the input-output finite-time stabilisation for a class of nonlinear stochastic system with state-dependent noise. The phenomenon of the missing measurements may occur when state signals are transmitted via communication networks. An estimating method is proposed to compensate the lost state information. And then, a compensator-based controller is designed to ensure the input-output finite-time stochastic stability (IO-FTSS) of the closed-loop system. Some parameters-dependent sufficient conditions are derived and the corresponding solving approach is given. Finally, numerical simulations are provided to demonstrate the feasibility and effectiveness of the developed IO-FTSS scheme.

  7. On moduli stabilisation and de Sitter vacua in MSSM heterotic orbifolds

    Energy Technology Data Exchange (ETDEWEB)

    Parameswaran, Susha L. [Uppsala Univ. (Sweden). Dept. of Physics and Astronomy; Ramos-Sanchez, Saul [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Zavala, Ivonne [Bonn Univ. (Germany). Bethe Center for Theoretical Physics and Physikalisches Inst.

    2010-09-15

    We study the problem of moduli stabilisation in explicit heterotic orbifold compactifications, whose spectra contain the MSSM plus some vector-like exotics that can be decoupled. Considering all the bulk moduli, we obtain the 4D low energy effective action for the compactification, which has contributions from various, computable, perturbative and non-perturbative effects. Hidden sector gaugino condensation and string worldsheet instantons result in a combination of racetrack, KKLT and cusp-form contributions to the superpotential, which lift all the bulk moduli directions. We point out the properties observed in our concrete models, which tend to be missed when only ''generic'' features of a model are assumed. We search for interesting vacua and find several de Sitter solutions, but so far, they all turn out to be unstable. (orig.)

  8. Long-term olfactory memories are stabilised via protein synthesis in Camponotus fellah ants

    DEFF Research Database (Denmark)

    Guerrieri, Fernando Javier; D'Ettorre, Patrizia; Deveaud, J-M.;

    2011-01-01

    of molecular bases of learning and memory. An open question is whether the memories formed upon olfactory learning that are retrievable several days after training are indeed based on de novo protein synthesis. Here, we addressed this question in the ant Camponotus fellah using a conditioning protocol in which......-chain hydrocarbons, one paired with sucrose and the other with quinine solution. Differential conditioning leads to the formation of a long-term memory retrievable at least 72¿h after training. Long-term memory consolidation was impaired by the ingestion of cycloheximide, a protein synthesis blocker, prior...... synthesis, long-term memories are stabilised via protein synthesis. Our behavioural protocol opens interesting research avenues to explore the cellular and molecular bases of olfactory learning and memory in ants....

  9. On Moduli Stabilisation and de Sitter Vacua in MSSM Heterotic Orbifolds

    CERN Document Server

    Parameswaran, Susha L; Zavala, Ivonne

    2010-01-01

    We study the problem of moduli stabilisation in explicit heterotic orbifold compactifications, whose spectra contain the MSSM plus some vector-like exotics that can be decoupled. Considering all the bulk moduli, we obtain the 4D low energy effective action for the compactification, which has contributions from various, computable, perturbative and non-perturbative effects. Hidden sector gaugino condensation and string worldsheet instantons result in a combination of racetrack, KKLT and cusp-form contributions to the superpotential, which lift all the bulk moduli directions. We point out the properties observed in our concrete models, which tend to be missed when only "generic" features of a model are assumed. We search for interesting vacua and find several de Sitter solutions, but -- so far -- they all turn out to be unstable.

  10. Evaluation of biocompatible stabilised gelled soya bean oil nanoparticles as new hydrophobic reservoirs.

    Science.gov (United States)

    Boudier, Ariane; Kirilov, Plamen; Franceschi-Messant, Sophie; Belkhelfa, Haouaria; Hadioui, Laila; Roques, Christine; Perez, Emile; Rico-Lattes, Isabelle

    2010-01-01

    Based on the organogel concept, in which an oil is trapped in a network of low-molecular-mass organic gelator fibres creating a gel, a formulation of gelled soya bean oil nanoparticles was evaluated for its capacity to form biocompatible hydrophobic reservoirs. The aqueous dispersions of nanoparticles were prepared by hot emulsification (T° > Tgel) and cooling at room temperature in the presence of polyethyleneimine (PEI). The dispersions were stabilised by the electrostatic interactions between the positively charged amino groups of the PEI and the negatively charged carboxylates of the gelator fibres present at the surface of the particles. The aqueous dispersions were highly stable (several months) and the gelled particles were able to entrap a hydrophobic fluorescent model molecule (Nile red), allowing testing in cells. The gelled oil nanoparticles were found to be biocompatible with the tested cells (keratinocytes) and had the ability to become rapidly internalised. Thus, organogel-based nanoparticles are a promising hydrophobic drug delivery system.

  11. A Stabilised Nodal Spectral Element Method for Fully Nonlinear Water Waves

    CERN Document Server

    Engsig-Karup, Allan Peter; Bigoni, Daniele

    2015-01-01

    We present an arbitrary-order spectral element method for general-purpose simulation of non-overturning water waves, described by fully nonlinear potential theory. The method can be viewed as a high-order extension of the classical finite element method proposed by Cai et al (1998) \\cite{CaiEtAl1998}, although the numerical implementation differs greatly. Features of the proposed spectral element method include: nodal Lagrange basis functions, a general quadrature-free approach and gradient recovery using global $L^2$ projections. The quartic nonlinear terms present in the Zakharov form of the free surface conditions can cause severe aliasing problems and consequently numerical instability for marginally resolved or very steep waves. We show how the scheme can be stabilised through a combination of over-integration of the Galerkin projections and a mild spectral filtering on a per element basis. This effectively removes any aliasing driven instabilities while retaining the high-order accuracy of the numerical...

  12. Production of nabumetone nanoparticles: Effect of molecular weight, concentration and nature of cellulose ether stabiliser.

    Science.gov (United States)

    Goodwin, D J; Martini, L G; Lawrence, M J

    2016-12-05

    The ability of a range of hydrophilic nonionic cellulose ethers (CEs) (namely methylhydroxethylcellulose, hydroxypropylmethylcellulose, ethylhydroxyethylcellulose, hydroxyethylcellulose and hydroxypropylcellulose) to prepare stable nabumetone nanoparticles (ultrasonication for varying lengths of time to yield CEs of lower molecular weight. Of the CEs tested, only hydroxyethylcellulose was found not to stabilise the production of nabumetone nanoparticles at any of the molecular weights tested, namely viscosity average molecular weights (Mv) in the range of 236-33kg/mol. All other CEs successfully stabilised nabumetone nanoparticles, with the lower molecular weight/viscosity polymers within a series being more likely to result in nanoparticle production than their higher molecular weight counterparts. Unfortunately due to the nature of the ultrasonication process, it was not possible to compare the size of nabumetone particles produced using polymers of identical Mv. There was, however, enough similarity in the Mv of the various polymers to draw the general conclusion that there was no strong correlation between the Mv of the various polymers and their ability to produce nanoparticles. For example hydroxypropylcellulose of 112.2kg/mol or less successfully produced nanoparticles while only ethylhydroxyethylcellulose and hydroxypropylmethyl polymers of 52 and 38.8kg/mol or less produced nanoparticles. These results suggest that polymer molecular weight is not the only determinant of nanoparticle production and that structure of the polymer is at least as important as its molecular weight. In particular the hydrophobic nature of the CE was thought to be an important factor in the production of nabumetone nanoparticles: the more hydrophobic the polymer, the stronger its interaction with nabumetone and the greater its ability to produce nanoparticles. In this context HPC was the most hydrophobic polymer and HEC the least hydrophobic. Copyright © 2016 Elsevier B.V. All

  13. Wiltse入路经椎弓根植骨治疗胸腰椎骨折%Transpedicular bone graft for the treatment of thoracolumbar vertebral fractures through Wiltse approach

    Institute of Scientific and Technical Information of China (English)

    王想福; 王兴盛

    2013-01-01

    目的:探讨Wiltse入路经椎弓根植骨治疗胸腰椎骨折的方法及临床疗效.方法:2009年3月至2012年2月,采用Wiltse入路经椎弓根植骨固定手术治疗胸腰段椎体骨折患者56例,其中男36例,女20例;年龄14~55岁,平均41岁;受伤至手术时间2~15d,平均3d.致伤原因:高处坠落伤25例,平地滑跌伤7例,交通事故伤20例,重物压砸伤4例.所有患者术前行MRI检查排除病理性骨折,并测量多裂肌与最长肌肌间隙距中线的距离,制定个性化方案,经椎弓根植骨器械采用自制改装套管针(用于椎体成形术).骨折按AO分型:A1型压缩型骨折33例,A2型劈裂骨折5例,A3型爆裂型骨折18例.56例中16例伴有脊髓损伤.术前神经功能损伤按Frankel分级:B级5例,C级2例,D级9例.术前腰痛Denis分级均为P5.按Frankel分级、腰痛Denis分级对神经功能及腰痛情况进行评估;手术前后及末次随访时通过影像学资料评价矫正效果.结果:56例患者均获随访,时间均超过24个月.末次随访时,神经功能Frankel分级:B级3例,C级2例,D级4例,E级7例.腰痛Denis分级:P1(无痛)32例,P2(偶有微痛,不需治疗)18例,P3(中度痛,偶服药)6例.伤椎前缘高度由(13.38±4.72) mm增加至(22.18±1.44) mm,Cobb角由(28.39±2.64)°减少至(10.07±3.05)°,术后无断钉、断杆、内固定松动、椎体再压缩等并发症.结论:Wiltse椎旁入路结合椎弓根植骨应用于胸腰段压缩性骨折,可有效减少术中出血及术后并发症,避免复位后的“蛋壳”椎体.掌握显露途径、制定详细术前计划及早期功能锻炼是治疗成功的关键.%Objective:To explore methods and therapeutic effects of transpedicular bone graft in treating thoracolumbar fractures through Wiltse approach.Methods:From March 2009 to February 2012,56 patients with thoracolumbar fractures were treated by transpedicular bone graft through Wiltse approach.Among them,there were 36 males and 20 females,ranging in

  14. Treatment of lumbar spondylolisthesis with viaposterior transpedicular instrumentation and intervertebral fusion%椎弓根螺钉复位固定加椎体间植骨融合治疗腰椎滑脱症

    Institute of Scientific and Technical Information of China (English)

    李敬朝

    2010-01-01

    目的 评价经后路椎弓根螺钉内固定并腰椎椎体间植骨融合术治疗腰椎滑脱的临床疗效.方法 对65例腰椎滑脱症患者行后路椎板减压,应用后路椎弓根螺钉内固定系统对腰椎滑脱椎体进行复位固定,椎体间或后外侧植骨融合.结果 随访6~24个月,临床优良率90.8%,6~12个月复查X线片均显示椎体间骨性融合.结论 本组采用椎管减压,椎体复位,椎弓根螺钉内固定并椎体间植骨融合治疗腰椎滑脱症,具有复位率、融合率高,疗效确切的特点,是治疗腰椎滑脱症比较理想的手术方式.%Objective To evaluate the clinical effect of treating lumbar spondylolisthesis with viaposterior transpedicular instrumentation and intervertebral fusion. Methods The posterior decompression and surgical treatment of transpedicle screw fixation system were used in 65 patients with lumbar spondylolisthesis, to fix spondylolis lumbar vertebrae and obtain vertebra fusion and posterolateral bone grafting fusion. Results The follow-up period ranged from 6 to 24 months. The clinical excellent rate was 92%. The interspinal solid fusion was observed in all patients in X-ray between 6 to 12 month s after operation. Conclusions This unit applies vertebrallamina decompression, vertebral body reposition, posterior transpadicular instrumentation and autoiliacbone intervertebral bone grafting to treat lumbar spondylolisthesis which shows a high rate of reposition, high fusion rate, definite curative effect and reduces the complication rate after lumbar operation. It is a good way of surgery.

  15. The Clinical Effects and Value of Surgical Treatment by Direct Transpedicular Osteo-Synthesis with Lag Screw in II Hangman,s Fracture%枢椎椎弓根拉力螺钉治疗II型Hangman骨折的疗效评价

    Institute of Scientific and Technical Information of China (English)

    陈小明; 曹奇; 杨铁军; 陈亮元; 唐国军; 颜学亮; 唐晓军

    2013-01-01

    目的:评价枢椎椎弓根拉力螺钉治疗II型Hangman骨折的临床疗效。方法对我科12例II型Hangman骨折采用双侧枢椎椎弓根拉力螺钉治疗,其中II型8例,IIa型4例,术前、术后及随访时分别评估脊髓神经功能及影像学资料。结果所有患者均获得随访,评均随访15个月(6~24月),手术平均时间65min(50~80min),无脊髓神经损伤及其他并发症,骨折均在术后3~6个月愈合,未出现螺钉断裂、松动,未见C2/3失稳及后凸畸形形成。结论枢椎椎弓根拉力螺钉能够安全、有效的治疗II型Hangman骨折。%Objective To discuss the clinical ef ects and value of surgical treatment by direct transpedicular osteosynthesis with lag screw for II Hangman,s Fracture. Method:12 patients with with acute traumatic spondylolisthesis of axis were treated by direct transpedicular osteo -synthesis with lag screw .8 patients classified as type II,4 patients classified as type IIa. Its image data and the function of spinal cord and nerves were col ected at pre-op,post-op and fol ow-up respectively. Result:Al patients were fol owed up,mean fol ow-up time is 15 months,it cost an average time of 65 minutes (50-80min)to finish the procedure. al cases gained bony fusion 3-6 months later and didn't any postoperation complicat -ions. The range of neck rotation was stored normal with no c2/3 instability、screw loosing or broking、kyphosis found. Conclusion:Transpedicular lag screw fixation can treated II Hangman,s Fracture safely and ef ectively.

  16. SINTESIS NANOPARTIKEL PERAK MENGGUNAKAN METODE POLIOL DENGAN AGEN STABILISATOR POLIVINILALKOHOL (PVA

    Directory of Open Access Journals (Sweden)

    DOB Apriandanu

    2014-06-01

    Full Text Available Abstrak __________________________________________________________________________________________ Nanopartikel perak merupakan produk berbasis nanoteknologi yang sedang berkembang saat ini dan dapat diaplikasikan sebagai katalis dan detektor sensor optik. Faktor yang dapat mempengaruhi ukuran nanopartikel adalah konsentrasi garam dan agen pereduksi. Nanopartikel perak bersifat tidak stabil. Oleh karena itu, perlu adanya penambahan polivinil alkohol sebagai agen stabilisator dalam sintesis nanopartikel perak. Tujuan penelitian ini adalah untuk mengetahui pengaruh rasio mol reduktor EG/Ag+ dan % PVA (b/v dalam sintesis nanopartikel perak terhadap karakteristik produk yang dihasilkan. Nanopartikel perak disintesis dengan metode poliol yaitu melarutkan AgNO3 ke dalam etilen glikol sebagai reduktor dan polivinilalkohol (PVA sebagai stabilisator. Karakterisasi dilakukan menggunakan Spek-trofotometer UV-Vis dan TEM (Transmission Electron Microscope. Analisis terhadap spektra UV-Vis menunjukkan bahwa nanopartikel yang relatif stabil pada pengukuran panjang gelombang maksimum 417 hingga 418 nm adalah nanopartikel yang disintesis menggunakan PVA 3%. Karakterisasi dengan TEM menunjukkan nanopartikel perak yang disintesis berdasarkan rasio mol etilen glikol terhadap Ag+ 50:1 memiliki ukuran terkecil dengan kisaran 10,15–27,56 nm dengan struktur kristal face centered cubic (FCC. Semakin tinggi rasio mol EG /Ag+ dalam sintesis nanopartikel perak, semakin tinggi pula peningkatan absorbansinya.   Abstract __________________________________________________________________________________________ Silver nanoparticles are nanotechnology based product which can be applied as a catalyst and optic sensor detector. The factors that can effect on nanoparticle size are salt concentration and reductor agent. Silver nanoparticles are unstable material, so polyvinylalcohol needs to be added  as a stabilizer agent in their synthesis. The aims of this research are to

  17. SINTESIS NANOPARTIKEL PERAK MENGGUNAKAN METODE POLIOL DENGAN AGEN STABILISATOR POLIVINILALKOHOL (PVA

    Directory of Open Access Journals (Sweden)

    DOB Apriandanu

    2014-06-01

    Full Text Available Abstrak __________________________________________________________________________________________ Nanopartikel perak merupakan produk berbasis nanoteknologi yang sedang berkembang saat ini dan dapat diaplikasikan sebagai katalis dan detektor sensor optik. Faktor yang dapat mempengaruhi ukuran nanopartikel adalah konsentrasi garam dan agen pereduksi. Nanopartikel perak bersifat tidak stabil. Oleh karena itu, perlu adanya penambahan polivinil alkohol sebagai agen stabilisator dalam sintesis nanopartikel perak. Tujuan penelitian ini adalah untuk mengetahui pengaruh rasio mol reduktor EG/Ag+ dan % PVA (b/v dalam sintesis nanopartikel perak terhadap karakteristik produk yang dihasilkan. Nanopartikel perak disintesis dengan metode poliol yaitu melarutkan AgNO3 ke dalam etilen glikol sebagai reduktor dan polivinilalkohol (PVA sebagai stabilisator. Karakterisasi dilakukan menggunakan Spek-trofotometer UV-Vis dan TEM (Transmission Electron Microscope. Analisis terhadap spektra UV-Vis menunjukkan bahwa nanopartikel yang relatif stabil pada pengukuran panjang gelombang maksimum 417 hingga 418 nm adalah nanopartikel yang disintesis menggunakan PVA 3%. Karakterisasi dengan TEM menunjukkan nanopartikel perak yang disintesis berdasarkan rasio mol etilen glikol terhadap Ag+ 50:1 memiliki ukuran terkecil dengan kisaran 10,15–27,56 nm dengan struktur kristal face centered cubic (FCC. Semakin tinggi rasio mol EG /Ag+ dalam sintesis nanopartikel perak, semakin tinggi pula peningkatan absorbansinya.   Abstract __________________________________________________________________________________________ Silver nanoparticles are nanotechnology based product which can be applied as a catalyst and optic sensor detector. The factors that can effect on nanoparticle size are salt concentration and reductor agent. Silver nanoparticles are unstable material, so polyvinylalcohol needs to be added  as a stabilizer agent in their synthesis. The aims of this research are to

  18. Re-use of stabilised flue gas ashes from solid waste incineration in cement-treated base layers for pavements

    DEFF Research Database (Denmark)

    Cai, Zuansi; Jensen, Dorthe Lærke; Christensen, Thomas Højlund

    2003-01-01

    . Two types of FGA were treated by the Ferrox-process, which removes the majority of the easily soluble salts in the FGA and provides binding sites for heavy metals in terms of ferrihydrite. Cubes of cement treated base layer materials containing 5% stabilised FGA were cast, sealed and cured for two...... weeks. Cylinders (diameter 100 mm, length 150 mm) were drilled from these cubes for tank leaching experiments. Duplicate specimens were subject to compression strength testing and to tank leaching experiments. The compressive strength of the CTB fulfilled the Danish requirements for CTB, i.e. strength...... more than 5 MPa after 7 days. The tank leaching tests revealed that leaching of heavy metals was not significantly affected by the use of chemically stabilised flue gas ashes from waste incineration. Assuming that diffusion controls the leaching process it was calculated that less than 1% of the metals...

  19. Selection of natural treatment processes for algae removal from stabilisation ponds effluents in Brasilia, using multicriterion methods.

    Science.gov (United States)

    Neder, K D; Carneiro, G A; Queiroz, T R; de Souza, M A A

    2002-01-01

    A multicriterion methodology is used in the evaluation and selection of the most appropriate alternative(s) for removing algae from stabilisation ponds effluents in a case study in Brasilia. For this purpose, five different natural treatment processes are tested at pilot scale: rock filter, sand filter, floating aquatic plants, constructed wetlands, and overland flow. These pilot units were constructed in Brasilia and set in parallel, each one receiving a portion of the effluent that comes from an existing wastewater treatment plant composed of preliminary treatment, UASB reactors, and high-rate stabilisation ponds. Several evaluation criteria are used in order to relate the capabilities of the post-treatment processes to the multiple objectives in this case. Two multicriterion decision-aid methods--compromise programming and ELECTRE-III--are used to select the most satisfying processes. The top ranking alternatives are indicated for subsequent studies, considering the possible implementation of these technologies to existing plants.

  20. Energy stable and momentum conserving interface stabilised finite element method for the incompressible Navier-Stokes equations

    CERN Document Server

    Labeur, Robert Jan

    2010-01-01

    An interface stabilised finite element method for the incompressible Navier-Stokes equations is presented. The method inherits the attractive stabilising mechanism of upwinded discontinuous Galerkin methods when momentum advection becomes significant, equal-order interpolations can be used for the velocity and pressure fields, and mass can be conserved locally. In contrast with discontinuous Galerkin methods, the number of global degrees of freedom is the same as for a continuous method on the same mesh. Different from earlier investigations on the approach for the Navier-Stokes equations, the pressure field in this work is discontinuous across cell boundaries. It is shown that this leads to very good local mass conservation and, for the appropriate choice of finite element spaces, momentum conservation. Also, in this work a new form of the momentum transport terms for the method is constructed such that global energy stability is guaranteed, even in the absence of a point-wise solenoidal velocity field. Mass...

  1. Influence of stabilising agents and pH on the size of SnO2 nanoparticles

    Directory of Open Access Journals (Sweden)

    Olga Rac

    2014-11-01

    Full Text Available According to recent research, the use of nanoparticles as a gas-sensitive material increases the selectivity and sensitivity and shortens the response time of a sensor. However, the synthesis of SnO2 nanoparticles presents many difficulties. The following article presents a simple and inexpensive method for the synthesis of SnO2 nanoparticles. The influence of the surfactant and polymer choice on the size of the resulting nanoparticles was investigated and a mechanism describing their interaction was proposed. It was found that stable colloids of SnO2 nanoparticles are formed in the presence of both PEI and Triton X-100 surfactants as stabilising agents. However, an additional factor essential for good stabilisation of the nanoparticles was an appropriate acidity level of the solution. Under optimal conditions, nanoparticles having an average diameter of about 10 nm are reproducibly formed.

  2. Cerium reduction at the interface between ceria and yttria-stabilised zirconia and implications for interfacial oxygen non-stoichiometry

    Energy Technology Data Exchange (ETDEWEB)

    Song, Kepeng [Stuttgart Center for Electron Microscopy, Max Planck Institute for Intelligent Systems, Heisenbergstraße 3, 70569 Stuttgart (Germany); Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Wenhua Road 72, 110016 Shenyang (China); Schmid, Herbert [INM-Leibniz Institute for New Materials, Campus D2 2, D-66123 Saarbrücken (Germany); Srot, Vesna; Aken, Peter A. van, E-mail: vanaken@is.mpg.de [Stuttgart Center for Electron Microscopy, Max Planck Institute for Intelligent Systems, Heisenbergstraße 3, 70569 Stuttgart (Germany); Gilardi, Elisa; Gregori, Giuliano; Maier, Joachim [Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart (Germany); Du, Kui [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Wenhua Road 72, 110016 Shenyang (China)

    2014-03-01

    Epitaxial CeO{sub 2} films with different thickness were grown on Y{sub 2}O{sub 3} stabilised Zirconia substrates. Reduction of cerium ions at the interface between CeO{sub 2} films and yttria stabilised zirconia substrates is demonstrated using aberration-corrected scanning transmission electron microscopy combined with electron energy-loss spectroscopy. It is revealed that most of the Ce ions were reduced from Ce{sup 4+} to Ce{sup 3+} at the interface region with a decay of several nanometers. Several possibilities of charge compensations are discussed. Irrespective of the details, such local non-stoichiometries are crucial not only for understanding charge transport in such hetero-structures but also for understanding ceria catalytic properties.

  3. Synthesis of gold nanoparticles stabilised by metal-chelator and the controlled formation of close-packed aggregates by them

    Indian Academy of Sciences (India)

    Santanu Bhattacharya; Aasheesh Srivastava

    2003-10-01

    Nanoparticles have properties that can be fine-tuned by their size as well as shape. Hence, there is significant current interest in preparing nano-materials of small size dispersity and to arrange them in close-packed aggregates. This manuscript describes ways of synthesising gold nanoparticles using a metal-chelator derivative 1, as stabiliser. Controlled synthesis conditions lead to formation of nanoparticles thereby indicating the ability of 1 to act as efficient stabiliser. The nanoparticles formed were characterised by transmission electron microscopy and UV-Vis spectroscopy. TEM analysis showed the formation of dense aggregates of nanoparticles. This can be ascribed to the inter-particle hydrogen bonding possible by the carboxylic acid moiety of 1 that leads to aggregation. The aggregation can be controlled by the pH of the solution employed for dispersing the particles.

  4. Geotechnical properties of peat soil stabilised with shredded waste tyre chips in combination with gypsum, lime or cement

    Directory of Open Access Journals (Sweden)

    M. Saberian

    2016-07-01

    Full Text Available Peat has a high content of water and organic substances. These weak components can cause low bearing capacity and high consolidation settlement under load, which means that peat deposits must usually be stabilised if they are to bear constructions such as buildings or roads. In this study we investigated the performance of waste tyre chips (10 % by weight and sand (400 kg m-3 supplemented with a pozzolanic binder (gypsum, lime or cement at a range of dosages (5 %, 10 % or 15 % by weight as a stabiliser for peat soil. Peat samples were taken from a fen peatland at Chaghakhor Wetland in Chahar Mahal and Bakhtiari Province, Iran. In total, 162 test specimens were prepared and subjected to laboratory strength testing (unconfined compression test and direct shear test. Additionally, the pH of each admixture was recorded immediately after mixing, elemental compositions were determined by X-Ray Fluorescence (XRF, and structures were examined using Scanning Electron Microscopy (SEM. It was observed that: (1 the total percentage of pozzolanic compounds in the peat soil was well below the minimum of 70 % set by the standard ASTM C 618 (ASTM 2000, so an additive such as cement, lime or gypsum would certainly be required; (2 specimens stabilised with gypsum or lime showed improvements in unconfined compressive strength (UCS, but those stabilised with ordinary Portland cement exhibited the greatest improvement in UCS (up to 12,200 % as well as improvements in the direct shear parameters c and φ; (3 according to the XRF tests, additives such as cement, lime and gypsum introduced considerable amounts of Si, Al, Ca and O, which are important for pozzolanic reactions in peat soils; and (4 on the basis of the results of UCS and direct shear tests, the optimum percentage of the additives tested would be 5 %.

  5. Re-use of stabilised flue gas ashes from solid waste incineration in cement-treated base layers for pavements.

    Science.gov (United States)

    Cai, Zuansi; Jensen, Dorthe L; Christensen, Thomas H; Bager, Dirch H

    2003-02-01

    Fly ash from coal-burning power plants has been used extensively as a pozzolan and fine filler in concrete for many years. Laboratory experiments were performed investigating the effect of substituting the coal-based fly ash with chemically stabilised flue gas ashes (FGA) from waste incineration. Two types of FGA were treated by the Ferrox-process, which removes the majority of the easily soluble salts in the FGA and provides binding sites for heavy metals in terms of ferrihydrite. Cubes of cement treated base layer materials containing 5% stabilised FGA were cast, sealed and cured for two weeks. Cylinders (diameter 100 mm, length 150 mm) were drilled from these cubes for tank leaching experiments. Duplicate specimens were subject to compression strength testing and to tank leaching experiments. The compressive strength of the CTB fulfilled the Danish requirements for CTB, i.e. strength more than 5 MPa after 7 days. The tank leaching tests revealed that leaching of heavy metals was not significantly affected by the use of chemically stabilised flue gas ashes from waste incineration. Assuming that diffusion controls the leaching process it was calculated that less than 1% of the metals would leach during a 100-year period from a 0.5 m thick concrete slab exposed to water on one side. Leaching of the common ions Ca, Cl, Na and SO4 was increased 3-20 times from the specimens with chemically stabilised flue gas ashes from waste incineration. However, the quantities leached were still modest. These experiments suggest that FGA from waste incineration after Ferrox-treatment could be re-used in CTB without compromising the strength and leaching from the base layer.

  6. Global sampled-data output feedback stabilisation for a class of nonlinear systems with unknown output function

    Science.gov (United States)

    Zhai, Jun-yong; Du, Hai-bo; Fei, Shu-min

    2016-03-01

    This paper discusses the problem of global sampled-data output feedback stabilisation for a class of nonlinear systems whose output function is unknown. A systematic design scheme is developed to construct a linear output feedback control law in sampled-data form. An explicit formula for the maximum allowable sampling period is computed to guarantee global stability of the uncertain nonlinear systems under the proposed controller with appropriate gains. Two examples are given to demonstrate the effectiveness of the proposed design procedure.

  7. Nanobiotechnology as a novel paradigm for enzyme immobilisation and stabilisation with potential applications in biodiesel production.

    Science.gov (United States)

    Verma, Madan Lal; Barrow, Colin J; Puri, Munish

    2013-01-01

    Nanobiotechnology is emerging as a new frontier of biotechnology. The potential applications of nanobiotechnology in bioenergy and biosensors have encouraged researchers in recent years to investigate new novel nanoscaffolds to build robust nanobiocatalytic systems. Enzymes, mainly hydrolytic class of enzyme, have been extensively immobilised on nanoscaffold support for long-term stabilisation by enhancing thermal, operational and storage catalytic potential. In the present report, novel nanoscaffold variants employed in the recent past for enzyme immobilisation, namely nanoparticles, nanofibres, nanotubes, nanopores, nanosheets and nanocomposites, are discussed in the context of lipase-mediated nanobiocatalysis. These nanocarriers have an inherently large surface area that leads to high enzyme loading and consequently high volumetric enzyme activity. Due to their high tensile strengths, nanoscale materials are often robust and resistant to breakage through mechanical shear in the running reactor making them suitable for multiple reuses. The optimisation of various nanosupports process parameters, such as the enzyme type and selection of suitable immobilisation method may help lead to the development of an efficient enzyme reactor. This might in turn offer a potential platform for exploring other enzymes for the development of stable nanobiocatalytic systems, which could help to address global environmental issues by facilitating the production of green energy. The successful validation of the feasibility of nanobiocatalysis for biodiesel production represents the beginning of a new field of research. The economic hurdles inherent in viably scaling nanobiocatalysts from a lab-scale to industrial biodiesel production are also discussed.

  8. Deformations on Tilted Tori and Moduli Stabilisation at the Orbifold Point

    CERN Document Server

    Blaszczyk, Michael; Koltermann, Isabel

    2015-01-01

    We discuss deformations of orbifold singularities on tilted tori in the context of Type IIA orientifold model building with D6-branes on special Lagrangian cycles. Starting from $T^6/(\\mathbb{Z}_2 \\times \\mathbb{Z}_2)$, we mod out an additional $\\mathbb{Z}_3$ symmetry to describe phenomenologically appealing backgrounds and reduce to $\\mathbb{Z}_3$ and $\\Omega\\mathcal{R}$ invariant orbits of deformations. While D6-branes carrying SO(2N) or USp(2N) gauge groups do not constrain deformations, D6-branes with U(N) gauge groups develop non-vanishing D-terms if they couple to previously singular, now deformed cycles. We present examples for both types of D6-branes, and in a three-generation Pati-Salam model on $T^6/(\\mathbb{Z}_2 \\times \\mathbb{Z}_6')$ we find that ten out of 15 twisted complex structure moduli are indeed stabilised at the orbifold point by the existence of the brane stacks.

  9. Use of Coal Bottom Ash as Mechanical Stabiliser in Subgrade Soil

    Directory of Open Access Journals (Sweden)

    Abdus Salaam Cadersa

    2014-01-01

    Full Text Available This paper presents the laboratory investigation work which forms part of a full scale research road project in Mauritius where coal bottom ash is used as mechanical stabiliser in a saprolitic subgrade soil. Three mixtures of subgrade soil and CBA were investigated in the laboratory, each containing varying percentages of coal bottom ash by weight (15%, 30%, and 40%, resp.. The laboratory research indicated that the mechanical properties of the subgrade soil are improved with the addition of bottom ash. Highest values for soaked and unsoaked CBR values were obtained for the mixture containing 30% by weight of bottom ash, which were 145% and 95%, respectively, as compared to 40% and 55% for the subgrade soil alone. Upon addition of coal bottom ash, a considerable decrease in swelling potential during soaking was observed for the mixture containing 40% by weight of CBA. The swell decreased from 0.17% for the subgrade soil alone to 0.04% for the mixture containing 40% by weight of CBA. Moreover, a CBA content of 30% resulted in a mix of intermediate plasticity as compared to the subgrade soil which is highly plastic. It is concluded that coal bottom ash can be used successfully as a mechanical stabilizer in the experimental subgrade soil by addition of 30 to 40% of CBA.

  10. High dose benzodiazepine dependence: description of 29 patients treated with flumazenil infusion and stabilised with clonazepam.

    Science.gov (United States)

    Quaglio, Gianluca; Pattaro, Cristian; Gerra, Gilberto; Mathewson, Sophie; Verbanck, Paul; Des Jarlais, Don C; Lugoboni, Fabio

    2012-08-15

    The withdrawal syndrome from benzodiazepine (BZD) can be severe and in some cases may impede cessation of the use of the drug. We present here a case series of benzodiazepine detoxification by flumazenil infusion, stabilised with clonazepam. Patients were treated with flumazenil 1.35 mg/day for a median of 7 days. Self-reported physical withdrawal symptoms were recorded daily. In addition to flumazenil, antidepressants were given before treatment commenced and clonazepam was administered nightly with both being continued after discharge. Twenty-nine patients were treated. No patients dropped out from the treatment programme. Nine patients (31%) required a temporary reduction/cessation of the infusion. The linear trend in the reduction of the daily withdrawal scores in the overall study population was significant. The linear trends were also significant in the group of patients for whom a temporary reduction/suspension of the flumazenil was required. Six months after treatment, 15 patients (53%) were abstinent from clonazepam and other BZDs. For five (21%) the BZD dependence were reinstated. More than two-thirds of the subjects tolerated the procedure well and about half had a good long term response. Slow flumazenil infusion appears to merit consideration as a possible future treatment. Suggestions for future research are examined.

  11. Enhancing osteoblast functions on a magnesia partially stabilised zirconia bioceramic by means of laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Hao, L. [Rapid Manufacturing Research Group, Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Leicestershire, LE11 3TU (United Kingdom)]. E-mail: l.hao@lboro.ac.uk; Ma, D.R. [Department of Plastic Surgery, Singapore General Hospital, Outram Road, Singapore 169608 (Singapore); Lawrence, J. [Manufacturing Engineering Division, School of Mechanical and Production Engineering, Nanyang Technological University (NTU), Nanyang Avenue, Singapore 639798 (Singapore); Zhu, X. [Singapore Eye Research Institute, Singapore General Hospital, Singapore 168759 (Singapore)

    2005-06-15

    In order to promote and sustain osteointegration of surrounding bone, a CO{sub 2} laser has been used to modify a magnesia partially stabilised zirconia (MgO-PSZ) for improved osteoblast cells' functions. The surface characterisation revealed that the increase in surface roughness, surface oxygen content and surface energy brought about the higher wettability characteristics of the MgO-PSZ following CO{sub 2} laser irradiation. The alkaline phosphatase synthesis, osteocalcin production and proliferation of human fetal osteoblasts (hFOB) were investigated using in vitro cellular models. It was found that the osteoblasts performed better on the CO{sub 2} laser treated sample than on the untreated sample in terms of these functions of osteoblasts. Wettability characteristics, which could influence protein adsorption and initial cell response, could be predominant mechanism active in improvement of the cell functions. The results of the study provided evidence that laser irradiation could be a promising surface processing tool of bioceramic for improved bonding with bone.

  12. Chemical stabilisation of lead in shooting range soils with phosphate and magnesium oxide: Synchrotron investigation.

    Science.gov (United States)

    Sanderson, Peter; Naidu, Ravi; Bolan, Nanthi; Lim, Jung Eun; Ok, Yong Sik

    2015-12-15

    Three Australian shooting range soils were treated with phosphate and magnesium oxide, or a combination of both to chemically stabilize Pb. Lead speciation was determined after 1 month ageing by X-ray absorption spectroscopy combined with linear combination fitting in control and treated soils. The predominant Pb species in untreated soils were iron oxide bound Pb, humic acid bound Pb and the mineral litharge. Treatment with phosphate resulted in substantial pyromorphite formation in two of the soils (TV and PE), accounting for up to 38% of Pb species present, despite the addition of excess phosphate. In MgO treated soils only, up to 43% of Pb was associated with MgO. Litharge and Pb hydroxide also formed as a result of MgO addition in the soils. Application of MgO after P treatment increased hydroxypyromorphite/pyromorphite formation relative to soils teated with phosphate only. X-ray diffraction and Scanning electron microscopy revealed PbO precipitate on the surface of MgO. Soil pH, (5.3-9.3) was an important parameter, as was the solubility of existing Pb species. The use of direct means of determination of the stabilisation of metals such as by X-ray absorption spectroscopy is desirable, particularly in relation to understanding long term stability of the immobilised contaminants.

  13. Synthesis of dense yttrium-stabilised hafnia pellets for nuclear applications by spark plasma sintering

    Energy Technology Data Exchange (ETDEWEB)

    Tyrpekl, Vaclav, E-mail: vaclav.tyrpekl@ec.europa.eu [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, D-76125 Karlsruhe (Germany); Holzhäuser, Michael; Hein, Herwin; Vigier, Jean-Francois; Somers, Joseph [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, D-76125 Karlsruhe (Germany); Svora, Petr [Institute of Inorganic Chemistry AS CR, v.v.i, Husinec-Rez 1001, 250 68 Rez (Czech Republic)

    2014-11-15

    Graphical abstract: Densification of HfO{sub 2}–Y{sub 2}O{sub 3} micro-beads by Spark Plasma Sintering High density pellets with homogenous distribution of Hf and Y serve as neutron absorbers. - Abstract: Dense yttrium–stabilised hafnia pellets (91.35 wt.% HfO{sub 2} and 8.65 wt.% Y{sub 2}O{sub 3}) were prepared by spark plasma sintering consolidation of micro-beads synthesised by the “external gelation” sol–gel technique. This technique allows a preparation of HfO{sub 2}–Y{sub 2}O{sub 3} beads with homogenous yttria–hafnia solid solution. A sintering time of 5 min at 1600 °C was sufficient to produce high density pellets (over 90% of the theoretical density) with significant reproducibility. The pellets have been machined in a lathe to the correct dimensions for use as neutron absorbers in an experimental test irradiation in the High Flux Reactor (HFR) in Petten, Holland, in order to investigate the safety of americium based nuclear fuels.

  14. Microstructural evolution of viscoelastic emulsions stabilised by sodium caseinate and xanthan gum.

    Science.gov (United States)

    Moschakis, Thomas; Murray, Brent S; Dickinson, Eric

    2005-04-15

    The time-dependent evolution of the phase-separated microstructure of a caseinate-stabilised emulsion containing xanthan gum added before emulsification has been investigated by confocal laser scanning microscopy, image analysis and rheology. Moderately low levels of xanthan addition lead to depletion flocculation and gravity-induced phase separation. Increasing the polysaccharide concentration causes immobilisation of the microstructure due to an increase in the local viscoelasticity: that is, the emulsion structure cannot easily rearrange to expel xanthan-enriched aqueous serum phase because a weak gel-like network is generated. The effect of xanthan on the evolving microstructure of phase-separated regions, which reflects indirectly the local emulsion micro-rheology, has been estimated from image analysis of time sequences of confocal micrographs. A comparison has been made between object shape analysis using four different shape descriptors. The roundness parameter has been found to be a convenient descriptor for reliably quantifying the structural change in terms of the relaxation rate of xanthan-rich aqueous drops. The Taylor parameter has been used to link the kinetics of drop relaxation to the time-dependent small-deformation rheological behaviour. The analysis of the combined experimental data reveals the difficulty of relating the evolving microstructure to bulk rheological measurements.

  15. Luxury uptake of phosphorus by microalgae in full-scale waste stabilisation ponds.

    Science.gov (United States)

    Powell, N; Shilton, A; Pratt, S; Chisti, Y

    2011-01-01

    Biological phosphorus removal was studied in two full-scale waste stabilisation ponds (WSP). Luxury uptake by microalgae was confirmed to occur and in one pond the biomass contained almost four times the phosphorus required by microalgae for normal metabolism. However, the phosphorus content within the biomass was variable. This finding means that assumptions made in prior publications on modelling of phosphorus removal in WSP are questionable. While fluctuations in microalgal growth causes variation in many water quality parameters, this further variation in luxury uptake explains the high degree of variability in phosphorus removal commonly reported in the literature. To achieve effective biological phosphorus removal high levels of both luxury uptake and microalgal concentration are needed. The findings of this work show that while high levels of these parameters did occur at times in the WSP monitored, they did not occur simultaneously. This is explained because accumulated phosphorus is subsequently consumed during rapid growth of biomass resulting in a high biomass concentration with a low phosphorus content. Previous laboratory research has allowed a number of key considerations to be proposed to optimise both luxury uptake and biomass concentration. Now that is has been shown that high levels of biomass concentration and luxury uptake can occur in the field it may be possible to redesign WSP to optimise these parameters.

  16. Modelling waste stabilisation ponds with an extended version of ASM3.

    Science.gov (United States)

    Gehring, T; Silva, J D; Kehl, O; Castilhos, A B; Costa, R H R; Uhlenhut, F; Alex, J; Horn, H; Wichern, M

    2010-01-01

    In this paper an extended version of IWA's Activated Sludge Model No 3 (ASM3) was developed to simulate processes in waste stabilisation ponds (WSP). The model modifications included the integration of algae biomass and gas transfer processes for oxygen, carbon dioxide and ammonia depending on wind velocity and a simple ionic equilibrium. The model was applied to a pilot-scale WSP system operated in the city of Florianópolis (Brazil). The system was used to treat leachate from a municipal waste landfill. Mean influent concentrations to the facultative pond of 1,456 g(COD)/m(3) and 505 g(NH4-N)/m(3) were measured. Experimental results indicated an ammonia nitrogen removal of 89.5% with negligible rates of nitrification but intensive ammonia stripping to the atmosphere. Measured data was used in the simulations to consider the impact of wind velocity on oxygen input of 11.1 to 14.4 g(O2)/(m(2) d) and sun radiation on photosynthesis. Good results for pH and ammonia removal were achieved with mean stripping rates of 18.2 and 4.5 g(N)/(m(2) d) for the facultative and maturation pond respectively. Based on measured chlorophyll a concentrations and depending on light intensity and TSS concentration it was possible to model algae concentrations.

  17. Effect of Alkaline-Stabilised Sewage Sludge on Extractable Organic Carbon and Copper in Soils

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An incubation experiment was conducted to evaluate the potential for water contamination with sludgederived organic substances and copper following land application of alkaline-stabilised sewage sludge. Two contrasting sludge-amended soils were studied. Both soils were previously treated with urban and rural alkaline biosolids separately at sludge application rates of 0, 30 and 120 t ha-1 fresh product. The air-dried soil/sludge mixtures were wetted with distilled water, maintained at 40 % of water-holding capacity and equilibrated for three weeks at 4 ℃ before extraction. Subsamples were extracted with either distilled water or 0.5 mol L-1 K2SO4 solution. The concentrations of organic C in the aqueous and chemical extracts were determined directly with a total organic carbon (TOC) analyser. The concentrations of Cu in the two extracts were also determined by atomic absorption spectrophotometry. The relationship between the two extractable organic C fractions was examined, together with that between extractable organic C concentration and extractable Cu concentration. Application of alkaline biosolids increased the concentrations of soil mobile organic substances and Cu. The results are discussed in terms of a possible increase in the potential for leaching of sludge-derived organics and Cu in the sludge-amended soils

  18. Taking wind into account in the design of waste stabilisation ponds.

    Science.gov (United States)

    Badrot-Nico, F; Guinot, V; Brissaud, F

    2010-01-01

    Up to now, most investigations on the dependency of the fluid flow patterns and performance of waste stabilisation ponds (WSPs) on wind speed and direction and pond layout have been performed using 2D and 3D CFD steady state isothermal models. 3D non steady state models integrating thermal processes and boundary conditions taking into account the full influence of meteorological factors are likely to provide more realistic predictions of WSP performance. Such modelling was undertaken for 4 pond layouts, 2 without baffles and 2 with baffles. Wind speed and direction were kept constant throughout each simulation while other meteorological forcings were derived from field measurements. Twelve wind directions and 2, 4 and 6 m s(-1) wind speeds were considered for each WSP layout. Simulations allowed verifying that the pond performance is dependent on the wind direction and velocity, that baffles may improve WSP performance and that the addition of well-designed baffles has the advantage of reducing its sensitivity to the wind.

  19. Twenty years' monitoring of Mèze stabilisation ponds: part II--Removal of faecal indicators.

    Science.gov (United States)

    Brissaud, F; Andrianarison, T; Brouillet, J L; Picot, B

    2005-01-01

    The WSP system serving Mèze and Poussan (French Mediterranean coast) was constructed in 1980 and enlarged and upgraded from 1994 to 1998. Water quality along the waste stabilisation pond to (WSP) system has been monitored over the years, thus allowing us to assess the influence of enlargement and upgrading works. A significant enhancement of the average microbiological quality of the effluent was observed, with respective E. coli and streptococci average abatements of 4.1 and 3.4 log. units. Former seasonal variations of microbiological removal have vanished. The contribution of the different ponds to the disinfection performance of the WSP system was analysed. A microbiological quality model was proposed to evaluate the die-off kinetics related to the different ponds and as a tool for the design and management of WSP systems. Though the relationships between die-off coefficients and environmental factors appeared somewhat frail, this modelling is considered a promising approach for the prediction of WSP microbiological performance.

  20. Treatment of post-orthodontic white spot lesions with casein phosphopeptide-stabilised amorphous calcium phosphate.

    Science.gov (United States)

    Bröchner, Ann; Christensen, Carsten; Kristensen, Bjarne; Tranæus, Sofia; Karlsson, Lena; Sonnesen, Liselotte; Twetman, Svante

    2011-06-01

    This study aims to investigate the effect of topical applications of 10% casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on white spot lesions (WSL) detected after treatment with fixed orthodontic appliances. Sixty healthy adolescents with ≥1 clinically visible WSL at debonding were recruited and randomly allocated to a randomised controlled trial with two parallel groups. The intervention group was instructed to topically apply a CPP-ACP -containing agent (Tooth Mousse, GC Europe) once daily and the subjects of the control group brushed their teeth with standard fluoride toothpaste. The intervention period was 4 weeks and the endpoints were quantitative light-induced fluorescence (QLF) on buccal surfaces of the upper incisors, cuspids and first premolars and visual scoring from digital photos. The attrition rate was 15%, mostly due to technical errors, and 327 lesions were included in the final evaluation. A statistically significant (p white spot lesions after debonding of orthodontic appliances with a casein phosphopeptide-stabilised amorphous calcium phosphate agent resulted in significantly reduced fluorescence and a reduced area of the lesions after 4 weeks as assessed by QLF. The improvement was however not superior to the "natural" regression following daily use of fluoride toothpaste.

  1. Epitaxial and non-epitaxial platinum, palladium and silver films on yttrium-stabilised zirconia

    Energy Technology Data Exchange (ETDEWEB)

    Beck, Gesa, E-mail: gesa.beck@physik.uni-augsburg.de [Institute of Physics, University Augsburg, Universitaetsstrasse 1a, 86159 Augsburg (Germany); Bachmann, Christoph [Institute of Physical Chemistry, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 58, 35392 Giessen (Germany); Bretzler, Rita [Research Institute Precious Metals & Metals Chemistry, Katharinenstrasse 17, 73525 Schwaebisch Gmuend (Germany); Kmeth, Ralf [Institute of Physics, University Augsburg, Universitaetsstrasse 1a, 86159 Augsburg (Germany)

    2015-05-05

    Platinum, palladium and silver films have been prepared on differently orientated YSZ (yttrium-stabilised zirconia) substrates by PLD (pulsed laser deposition). The deposition temperatures for platinum were 200 °C and 400 °C, whereas palladium and silver were deposited only at 200 °C. The microstructure of the films depends on the particular metal, on the orientation of the substrate and on the deposition temperature. Platinum – deposited at 400 °C – forms single crystalline, epitaxial (111), (311) and (110) orientated as well as (111) orientated polycrystalline films. Platinum, palladium and silver – deposited at 200 °C – always form (111) orientated and polycrystalline films, in some cases also with a fraction of epitaxial grown grains. The formed microstructures were discussed on the basis of interface and surface energy minimization and structure zone models. - Highlights: • Pt, Pd and Ag films are prepared on differently orientated YSZ. • Substrate orientation and deposition temperature influences the microstructure. • Pt forms epitaxial and polycrystalline films. • Pd and Ag form polycrystalline films, sometimes with epitaxial grown grains. • The formed microstructures are described by energy minimization.

  2. Stabilisation and precision pointing quadrupole magnets in the Compact Linear Collider (CLIC)

    CERN Document Server

    Janssens, Stef; van den Brand, Jo; Bertolini, Alessandro; Artoos, Kurt

    This thesis describes the research done to provide stabilisation and precision positioning for the main beam quadrupole magnets of the Compact Linear Collider CLIC. The introduction describes why new particle accelerators are needed to further the knowledge of our universe and why they are linear. A proposed future accelerator is the Compact Linear Collider (CLIC) which consists of a novel two beam accelerator concept. Due to its linearity and subsequent single pass at the interaction point, this new accelerator requires a very small beam size at the interaction point, in order to increase collision effectiveness. One of the technological challenges, to obtain these small beam sizes at the interaction point, is to keep the quadrupole magnets aligned and stable to 1.5 nm integrated r.m.s. in vertical and 5 nm integrated root mean square (r.m.s.) in lateral direction. Additionally there is a proposal to create an intentional offset (max. 50 nm every 20 ms with a precision of +/- 1 nm), for several quadrupole ma...

  3. Flat-relative optimal extraction. A quick and efficient algorithm for stabilised spectrographs

    CERN Document Server

    Zechmeister, M; Reiners, A

    2013-01-01

    Optimal extraction is a key step in processing the raw images of spectra as registered by two-dimensional detector arrays to a one-dimensional format. Previously reported algorithms reconstruct models for a mean one-dimensional spatial profile to assist a properly weighted extraction. We outline a simple optimal extraction algorithm including error propagation, which is very suitable for stabilised, fibre-fed spectrographs and does not model the spatial profile shape. A high signal-to-noise, master-flat image serves as reference image and is directly used as an extraction profile mask. Each extracted spectral value is the scaling factor relative to the cross-section of the unnormalised master-flat which contains all information about the spatial profile as well as pixel-to-pixel variations, fringing, and blaze. The extracted spectrum is measured relative to the flat spectrum. Using echelle spectra of the HARPS spectrograph we demonstrate a competitive extraction performance in terms of signal-to-noise and sho...

  4. Characteristics of Oxidative Storage Stability of Canola Fatty Acid Methyl Ester Stabilised with Antioxidants

    Directory of Open Access Journals (Sweden)

    Tirto Prakoso

    2012-11-01

    Full Text Available The storage effects on the oxidation characteristics of fatty acid methyl ester of canola oil (CME were investigated in this study. CME stabilised with two antioxidants, i.e. 2,6-di-tert-bytyl-p-cresol (BHT and 6,6-di-tert-butyl-2, 2’-methylendi-p-cresol (BPH, was stored at 20, 40 and 60°C. The oxidation stability data were measured by the Rancimat test method and it was found that both BHT and BPH addition increased the oxidation resistance of the CME. The results showed that when BPH or BHT was added at a concentration of 100 ppm, the oxidation induction period of the neat CME samples increased from 5.53 h to 6.93 h and 6.14 h, respectively. Comparing both antioxidants, BPH proved to be more effective in increasing the oxidation resistance when both antioxidants were added at the same concentration. Furthermore, the oxidation induction time decreased linearly with the storage time. It was shown that the oxidation occurred rapidly in the first 8 weeks of storage. Later, a kinetic study was undertaken and first-order kinetics were applied to explain the oxidation characteristics of the CME added with antioxidants. This kinetic study focused on exploiting the activation energy values obtained from the Arrhenius equations. Also, the oxidation effects on other quality parameters, including acid value, peroxide value, kinematic viscosity, and water content, were examined.

  5. Early rehabilitation following less invasive surgical stabilisation plate fixation for distal femoral fractures.

    Science.gov (United States)

    Smith, T O; Hedges, C; MacNair, R; Schankat, K

    2009-06-01

    The less invasive surgical stabilisation (LISS) plate fixation method is an orthopaedic procedure for the fixation of distal femoral fractures. Early physiotherapy treatments of motion and mobilisation have been advocated following this procedure. This article critically appraises the evidence base assessing the early rehabilitation of patients following LISS fixation for distal femoral fractures. A review of EMBASE, Medline, CINAHL and AMED, and a hand search were undertaken. Two independent reviewers identified all eligible articles. Two reviewers extracted the data, which were verified by a third reviewer. All included articles were critically appraised by two independent reviewers using the Critical Appraisal Skills Programme tool. Seventeen case series assessing 508 patients with 535 fractures were reviewed. No clinical trials comparing physiotherapy programmes were identified. The review identified that following LISS fixation for distal femoral fractures, patients begin range-of-motion exercises immediately and are initially required to restrict weight-bearing following surgery. It remains unclear whether casts, braces or immobilisation aids are applied during the initial postoperative period. The efficacy of different physiotherapy protocols following LISS fixation for distal femoral fractures remains unclear. Further well-designed randomised controlled trials are required to compare different postoperative physiotherapy rehabilitation programmes for patients following LISS fixation of distal femoral fractures in order to determine the optimal postoperative management for this complex patient group.

  6. Stabilisation of composite LSFCO-CGO based anodes for methane oxidation in solid oxide fuel cells

    Science.gov (United States)

    Sin, A.; Kopnin, E.; Dubitsky, Y.; Zaopo, A.; Aricò, A. S.; Gullo, L. R.; Rosa, D. La; Antonucci, V.

    A La 0.6Sr 0.4Fe 0.8Co 0.2O 3-Ce 0.8Gd 0.2O 1.9 (LSFCO-CGO) composite anode material was investigated for the direct electrochemical oxidation of methane in intermediate temperature solid oxide fuel cells (IT-SOFCs). A maximum power density of 0.17 W cm -2 at 800 °C was obtained with a methane-fed ceria electrolyte-supported SOFC. A progressive increase of performance was recorded during 140 h operation with dry methane. The anode did not show any structure degradation after the electrochemical testing. Furthermore, no formation of carbon deposits was detected by electron microscopy and elemental analysis. Alternatively, this perovskite material showed significant chemical and structural modifications after high temperature treatment in a dry methane stream in a packed-bed reactor. It is derived that the continuous supply of mobile oxygen anions from the electrolyte to the LSFCO anode, promoted by the mixed conductivity of CGO electrolyte at 800 °C, stabilises the perovskite structure near the surface under SOFC operation and open circuit conditions.

  7. Three-year performance of in-situ mass stabilised contaminated site soils using MgO-bearing binders.

    Science.gov (United States)

    Wang, Fei; Jin, Fei; Shen, Zhengtao; Al-Tabbaa, Abir

    2016-11-15

    This paper provides physical and chemical performances of mass stabilised organic and inorganic contaminated site soils using a new group of MgO-bearing binders over 3 years and evaluated the time-dependent performance during the 3 years. This study took place at a contaminated site in Castleford, UK in 2011, where MgO, ground granulated blastfurnace slag (GGBS) and Portland cement (PC) were mixed with the contaminated soils in a dry form using the ALLU mass mixing equipment. Soil cores were retrieved 40-day, 1-year and 3-year after the treatment. The core quality, strength, and the leaching properties were determined via physical observation, unconfined compressive strength (UCS) and batch leaching tests. After 3-year treatment, the UCS values of ALLU mixes were in the range of 50-250kPa; the leachate concentrations of Cd, Pb, Cu and Zn (except Ni) in all mixes were lower than their drinking water standards; and the leachability of total organics was in the range of 10-105mg/L. No apparent degradation of the mass stabilised materials after 3 years' exposure to the field conditions was found. MgO-GGBS blends were found able to provide higher strength and less leachability of contaminants compared to PC and MgO-only mixes in mass stabilised soils.

  8. Performance evaluation of the bioreactor landfill in treatment and stabilisation of mechanically biologically treated municipal solid waste.

    Science.gov (United States)

    Lakshmikanthan, P; Sivakumar Babu, G L

    2017-03-01

    The potential of bioreactor landfills to treat mechanically biologically treated municipal solid waste is analysed in this study. Developing countries like India and China have begun to investigate bioreactor landfills for municipal solid waste management. This article describes the impacts of leachate recirculation on waste stabilisation, landfill gas generation, leachate characteristics and long-term waste settlement. A small-scale and large-scale anaerobic cell were filled with mechanically biologically treated municipal solid waste collected from a landfill site at the outskirts of Bangalore, India. Leachate collected from the same landfill site was recirculated at the rate of 2-5 times a month on a regular basis for 370 days. The total quantity of gas generated was around 416 L in the large-scale reactor and 21 L in the small-scale reactor, respectively. Differential settlements ranging from 20%-26% were observed at two different locations in the large reactor, whereas 30% of settlement was observed in the small reactor. The biological oxygen demand/chemical oxygen demand (COD) ratio indicated that the waste in the large reactor was stabilised at the end of 1 year. The performance of the bioreactor with respect to the reactor size, temperature, landfill gas and leachate quality was analysed and it was found that the bioreactor landfill is efficient in the treatment and stabilising of mechanically biologically treated municipal solid waste.

  9. Stabilisation dopant-dependent facilitation in ionic conductivity on millimeter-wave irradiation heating of zirconia-based ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Kishimoto, Akira, E-mail: kishim-a@cc.okayama-u.ac.jp; Hasunuma, Hideki; Teranishi, Takashi; Hayashi, Hidetaka

    2015-11-05

    Ionic conductivity was measured on scandia-, calcia-, and gadolinia-stabilised zirconia ceramics under quasi-millimeter-wave (MMW) irradiation heating and conventional heating. Conductivity enhancement was evaluated for these ceramics and compared with our previous report on yttria- and ytterbia-stabilised zirconia ceramics (YSZ and YbSZ, respectively). The ionic conduction for the various cation-substituted zirconia ceramics was enhanced under MMW irradiation heating. In the case of scandia-stabilisation, the optimal composition demonstrating maximum ionic conductivity was 12-mol% zirconia (ScSZ) under MMW irradiation heating, which was larger than under conventional heating. Such an optimal composition shift was similar to results for YSZ ceramics. These results are discussed in terms of the activation energies for vacancy–ion dissociation and ion transfer. - Highlights: • Under millimeter-wave irradiation heating ionic conductivity of zirconia ceramics was examined. • The optimal composition in scandium stabilized zirconia ceramics shifted the higher doping side. • MMW irradiation heated ScSZ showed the highest ionic conductivity value in zirconia ceramics ever reported. • The activation process was examined in relation to the non-thermal effects.

  10. Study of the electronics architecture for the mechanical stabilisation of the quadrupoles of the CLIC linear accelerator

    Science.gov (United States)

    Artoos, K.; Collette, C.; Fernandez Carmona, P.; Guinchard, M.; Hauviller, C.; Janssens, S.; Kuzmin, A.; Slaathaug, A.

    2010-11-01

    To reach a sufficient luminosity, the transverse beam sizes and emittances in future linear particle accelerators should be reduced to the nanometer level. Mechanical stabilisation of the quadrupole magnets is of the utmost importance for this. The piezo actuators used for this purpose can also be used to make fast incremental orientation adjustments with a nanometer resolution. The main requirements for the CLIC stabilisation electronics is a robust, low noise, low delay, high accuracy and resolution, low band and radiation resistant feedback control loop. Due to the high number of controllers (about 4000) a cost optimization should also be made. Different architectures are evaluated for a magnet stabilisation prototype, including the sensors type and configuration, partition between software and hardware for control algorithms, and optimization of the ADC/DAC converters. The controllers will be distributed along the 50 km long accelerator and a communication bus should allow external control. Furthermore, one might allow for an adaptive method to increase the S/N ratio of vibration measurements by combining seismometer measurements of adjacent magnets. Finally a list of open topics, the current limitations and the plans to overcome them will be presented.

  11. Dynamics

    CERN Document Server

    Goodman, Lawrence E

    2001-01-01

    Beginning text presents complete theoretical treatment of mechanical model systems and deals with technological applications. Topics include introduction to calculus of vectors, particle motion, dynamics of particle systems and plane rigid bodies, technical applications in plane motions, theory of mechanical vibrations, and more. Exercises and answers appear in each chapter.

  12. Sorption of selenate on soils and pure phases: kinetic parameters and stabilisation

    Energy Technology Data Exchange (ETDEWEB)

    Loffredo, N. [Institut de Radioprotection et Surete Nucleaire (IRSN), DEI/SECRE/Laboratoire de Radioecologie et d' Ecotoxicologie, Cadarache, Bat 186, BP3, 13115 Saint-Paul-lez-Durance Cedex (France); Mounier, S. [Laboratoire PROTEE, Universite du Sud Toulon-Var, BP 20132, La Garde 83957 (France); Thiry, Y. [Agence Nationale pour la gestion des Dechets Radioactifs (Andra), Parc de la Croix Blanche, 1/7 rue Jean Monnet, 92298 Chatenay-Malabry Cedex (France); Coppin, F., E-mail: frederic.coppin@irsn.fr [Institut de Radioprotection et Surete Nucleaire (IRSN), DEI/SECRE/Laboratoire de Radioecologie et d' Ecotoxicologie, Cadarache, Bat 186, BP3, 13115 Saint-Paul-lez-Durance Cedex (France)

    2011-09-15

    This study was conducted to identify the principle selenate carrier phases for two selected soils, by comparing their reactivity with selenate to that of pure phases of the solids. Silica, calcium carbonate, aluminium hydroxide, goethite, bentonite and humic acid were selected as the main soil carrier phases. Comparisons were made first on the parameter values obtained with the best fit of a kinetic sorption model which can discriminate instantaneous sorption from kinetically limited sorption. Then comparisons were made of the ability for each solid to stabilise selenate by measuring the ratio of the partition coefficient for sorption (Kd{sub sorption}) over that of the desorption (Kd{sub desorption}). Kinetics and stabilisation were used to help elucidate the nature of interactions with the test solid phases for a large range of selenate concentrations. The experiments were conducted over 165 h in batch reactors, the solid being isolated from the solution by dialysis tubing, at two pH (5.4 and 8) and three selenate concentrations (1 x 10{sup -3}, 1 x 10{sup -6} and 1 x 10{sup -8} mol L{sup -1}). The results obtained showed that only aluminium hydroxide can sorb selenate throughout the studied pH range (pH 5.4 to 8.0). The sorption capacity on this mineral was high (Kd{sub sorption} > 100 to 1 x 10{sup 4} L kg{sup -1}) and the selenate was mainly stabilized by the formation of inner sphere complexes. The sorption on goethite occurred at pH 5.4 (Kd{sub sorption} 52 L kg{sup -1}), mainly as outer sphere complexes, and was null at pH 8. On silica, a weak sorption was observed only at pH 5.4 and at 165 h (Kd{sub sorption} 4 L kg{sup -1}). On bentonite, calcium carbonate and humic acid no significant sorption was observed. Concerning the two soils studied, different behaviours were observed for selenate. For soil Ro (pH 5.4), Kd{sub sorption} was low (8 L kg{sup -1}) compared to soil Bu (pH 8) (70 L kg{sup -1}). The sorption behaviour of selenate on soil Ro was mainly

  13. A stabilised nodal spectral element method for fully nonlinear water waves

    Science.gov (United States)

    Engsig-Karup, A. P.; Eskilsson, C.; Bigoni, D.

    2016-08-01

    We present an arbitrary-order spectral element method for general-purpose simulation of non-overturning water waves, described by fully nonlinear potential theory. The method can be viewed as a high-order extension of the classical finite element method proposed by Cai et al. (1998) [5], although the numerical implementation differs greatly. Features of the proposed spectral element method include: nodal Lagrange basis functions, a general quadrature-free approach and gradient recovery using global L2 projections. The quartic nonlinear terms present in the Zakharov form of the free surface conditions can cause severe aliasing problems and consequently numerical instability for marginally resolved or very steep waves. We show how the scheme can be stabilised through a combination of over-integration of the Galerkin projections and a mild spectral filtering on a per element basis. This effectively removes any aliasing driven instabilities while retaining the high-order accuracy of the numerical scheme. The additional computational cost of the over-integration is found insignificant compared to the cost of solving the Laplace problem. The model is applied to several benchmark cases in two dimensions. The results confirm the high order accuracy of the model (exponential convergence), and demonstrate the potential for accuracy and speedup. The results of numerical experiments are in excellent agreement with both analytical and experimental results for strongly nonlinear and irregular dispersive wave propagation. The benefit of using a high-order - possibly adapted - spatial discretisation for accurate water wave propagation over long times and distances is particularly attractive for marine hydrodynamics applications.

  14. Solidification/stabilisation of electric arc furnace waste using low grade MgO.

    Science.gov (United States)

    Cubukcuoglu, B; Ouki, S K

    2012-02-01

    This study aims to evaluate the potential of low grade MgO (LGMgO) for the stabilisation/solidification (S/S) of heavy metals in steel electric arc furnace wastes. Relevant characteristics such as setting time, unconfined compressive strength (UCS) and leaching behaviour assessed by acid neutralisation capacity (ANC), monolithic and granular leaching tests were examined in light of the UK landfill Waste Acceptance Criteria (WAC) for disposal. The results demonstrated that all studied mix designs with Portland cement type 1 (CEM1) and LGMgO, CEM1-LGMgO 1:2 and 1:4 at 40% and 70% waste addition met the WAC requirements by means of UCS, initial and final setting times and consistence. Most of the ANC results met the WAC limits where the threshold pH values without acid additions were stable and between 11.9 and 12.2 at 28d. Granular leaching results indicate fixation of most of the metals at all mix ratios. An optimum ratio was obtained at CEM1-LGMgO 1:4 at 40% waste additions where none of the metals leaching exceeded the WAC limits and hence may be considered for landfill disposal. The monolithic leaching test results showed that LGMgO performed satisfactorily with respect to S/S of Zn, as the metal component present at the highest concentration level in the waste exhibited very little leaching and passed the leaching test requirement at all mix ratios studied. However, its performance with respect to Pb, Cd and Cr was less effective in reducing their leaching suggesting a higher cumulative rate under those leaching regimes.

  15. Soil stabilisation using AMD sludge, compost and lignite: TCLP leachability and continuous acid leaching.

    Science.gov (United States)

    Tsang, Daniel C W; Olds, William E; Weber, Paul A; Yip, Alex C K

    2013-11-01

    Utilising locally available industrial by-products for in situ metal stabilisation presents a low-cost remediation approach for contaminated soil. This study explored the potential use of inorganic (acid mine drainage (AMD) sludge and zero-valent iron) and carbonaceous materials (green waste compost, manure compost, and lignite) for minimising the environmental risks of As and Cu at a timber treatment site. After 9-month soil incubation, significant sequestration of As and Cu in soil solution was accomplished by AMD sludge, on which adsorption and co-precipitation could take place. The efficacy of AMD sludge was comparable to that of zero-valent iron. There was marginal benefit of adding carbonaceous materials. However, in a moderately aggressive environment (Toxicity Characteristic Leaching Procedure), AMD sludge only suppressed the leachability of As but not Cu. Therefore, the provision of compost and lignite augmented the simultaneous reduction of Cu leachability, probably via surface complexation with oxygen-containing functional groups. Under continuous acid leaching in column experiments, combined application of AMD sludge with compost proved more effective than AMD sludge with lignite. This was possibly attributed to the larger amount of dissolved organic matter with aromatic moieties from lignite, which may enhance Cu and As mobility. Nevertheless, care should be taken to mitigate ecological impact associated with short-term substantial Ca release and continuous release of Al at a moderate level under acid leaching. This study also articulated the engineering implications and provided recommendations for field deployment, material processing, and assessment framework to ensure an environmentally sound application of reactive materials. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Calculations of single crystal elastic constants for yttria partially stabilised zirconia from powder diffraction data

    Energy Technology Data Exchange (ETDEWEB)

    Lunt, A. J. G., E-mail: alexander.lunt@eng.ox.ac.uk; Xie, M. Y.; Baimpas, N.; Korsunsky, A. M. [Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ (United Kingdom); Zhang, S. Y.; Kabra, S.; Kelleher, J. [ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Harwell, Oxford OX11 0QX (United Kingdom); Neo, T. K. [Specialist Dental Group, Mount Elizabeth Orchard, 3 Mount Elizabeth, #08-03/08-08/08-10, Singapore 228510 (Singapore)

    2014-08-07

    Yttria Stabilised Zirconia (YSZ) is a tough, phase-transforming ceramic that finds use in a wide range of commercial applications from dental prostheses to thermal barrier coatings. Micromechanical modelling of phase transformation can deliver reliable predictions in terms of the influence of temperature and stress. However, models must rely on the accurate knowledge of single crystal elastic stiffness constants. Some techniques for elastic stiffness determination are well-established. The most popular of these involve exploiting frequency shifts and phase velocities of acoustic waves. However, the application of these techniques to YSZ can be problematic due to the micro-twinning observed in larger crystals. Here, we propose an alternative approach based on selective elastic strain sampling (e.g., by diffraction) of grain ensembles sharing certain orientation, and the prediction of the same quantities by polycrystalline modelling, for example, the Reuss or Voigt average. The inverse problem arises consisting of adjusting the single crystal stiffness matrix to match the polycrystal predictions to observations. In the present model-matching study, we sought to determine the single crystal stiffness matrix of tetragonal YSZ using the results of time-of-flight neutron diffraction obtained from an in situ compression experiment and Finite Element modelling of the deformation of polycrystalline tetragonal YSZ. The best match between the model predictions and observations was obtained for the optimized stiffness values of C11 = 451, C33 = 302, C44 = 39, C66 = 82, C12 = 240, and C13 = 50 (units: GPa). Considering the significant amount of scatter in the published literature data, our result appears reasonably consistent.

  17. Sludge accumulation and distribution impact the hydraulic performance in waste stabilisation ponds.

    Science.gov (United States)

    Coggins, Liah X; Ghisalberti, Marco; Ghadouani, Anas

    2017-03-01

    Waste stabilisation ponds (WSPs) are used worldwide for wastewater treatment, and throughout their operation require periodic sludge surveys. Sludge accumulation in WSPs can impact performance by reducing the effective volume of the pond, and altering the pond hydraulics and wastewater treatment efficiency. Traditionally, sludge heights, and thus sludge volume, have been measured using low-resolution and labour intensive methods such as 'sludge judge' and the 'white towel test'. A sonar device, a readily available technology, fitted to a remotely operated vehicle (ROV) was shown to improve the spatial resolution and accuracy of sludge height measurements, as well as reduce labour and safety requirements. Coupled with a dedicated software package, the profiling of several WSPs has shown that the ROV with autonomous sonar device is capable of providing sludge bathymetry with greatly increased spatial resolution in a greatly reduced profiling time, leading to a better understanding of the role played by sludge accumulation in hydraulic performance of WSPs. The high-resolution bathymetry collected was used to support a much more detailed hydrodynamic assessment of systems with low, medium and high accumulations of sludge. The results of the modelling show that hydraulic performance is not only influenced by the sludge accumulation, but also that the spatial distribution of sludge plays a critical role in reducing the treatment capacity of these systems. In a range of ponds modelled, the reduction in residence time ranged from 33% in a pond with a uniform sludge distribution to a reduction of up to 60% in a pond with highly channelized flow. The combination of high-resolution measurement of sludge accumulation and hydrodynamic modelling will help in the development of frameworks for wastewater sludge management, including the development of more reliable computer models, and could potentially have wider application in the monitoring of other small to medium water bodies

  18. Ecosystem function in waste stabilisation ponds: Improving water quality through a better understanding of biophysical coupling

    Science.gov (United States)

    Ghadouani, Anas; Reichwaldt, Elke S.; Coggins, Liah X.; Ivey, Gregory N.; Ghisalberti, Marco; Zhou, Wenxu; Laurion, Isabelle; Chua, Andrew

    2014-05-01

    Wastewater stabilisation ponds (WSPs) are highly productive systems designed to treat wastewater using only natural biological and chemical processes. Phytoplankton, microbial communities and hydraulics play important roles for ecosystem functionality of these pond systems. Although WSPs have been used for many decades, they are still considered as 'black box' systems as very little is known about the fundamental ecological processes which occur within them. However, a better understanding of how these highly productive ecosystems function is particularly important for hydrological processes, as treated wastewater is commonly discharged into streams, rivers, and oceans, and subject to strict water quality guidelines. WSPs are known to operate at different levels of efficiency, and treatment efficiency of WSPs is dependent on physical (flow characteristics and sludge accumulation and distribution) and biological (microbial and phytoplankton communities) characteristics. Thus, it is important to gain a better understanding of the role and influence of pond hydraulics and vital microbial communities on pond performance and WSP functional stability. The main aim of this study is to investigate the processes leading to differences in treatment performance of WSPs. This study uses a novel and innovative approach to understand these factors by combining flow cytometry and metabolomics to investigate various biochemical characteristics, including the metabolite composition and microbial community within WSPs. The results of these analyses will then be combined with results from the characterisation of pond hydrodynamics and hydraulic performance, which will be performed using advanced hydrodynamic modelling and advanced sludge profiling technology. By understanding how hydrodynamic and biological processes influence each other and ecosystem function and stability in WSPs, we will be able to propose ways to improve the quality of the treatment using natural processes, with

  19. CDC25B overexpression stabilises centrin 2 and promotes the formation of excess centriolar foci.

    Directory of Open Access Journals (Sweden)

    Rose Boutros

    Full Text Available CDK-cyclin complexes regulate centriole duplication and microtubule nucleation at specific cell cycle stages, although their exact roles in these processes remain unclear. As the activities of CDK-cyclins are themselves positively regulated by CDC25 phosphatases, we investigated the role of centrosomal CDC25B during interphase. We report that overexpression of CDC25B, as is commonly found in human cancer, results in a significant increase in centrin 2 at the centrosomes of interphase cells. Conversely, CDC25B depletion causes a loss of centrin 2 from the centrosome, which can be rescued by treatment with the proteasome inhibitor MG132. CDC25B overexpression also promotes the formation of excess centrin 2 "foci". These foci can accumulate other centrosome proteins, including γ-tubulin and PCM-1, and can function as microtubule organising centres, indicating that these represent functional centrosomes. Formation of centrin 2 foci can be blocked by specific inhibition of CDK2 but not CDK1. CDK2-mediated phosphorylation of Monopolar spindle 1 (Mps1 at the G1/S transition is essential for the initiation of centrosome duplication, and Mps1 is reported to phosphorylate centrin 2. Overexpression of wild-type or non-degradable Mps1 exacerbated the formation of excess centrin 2 foci induced by CDC25B overexpression, while kinase-dead Mps1 has a protective effect. Together, our data suggest that CDC25B, through activation of a centrosomal pool of CDK2, stabilises the local pool of Mps1 which in turn regulates the level of centrin 2 at the centrosome. Overexpression of CDC25B may therefore contribute to tumourigenesis by perturbing the natural turnover of centrosome proteins such as Mps1 and centrin 2, thus resulting in the de novo assembly of extra-numerary centrosomes and potentiating chromosome instability.

  20. Suitability of constructed wetlands and waste stabilisation ponds in wastewater treatment: nitrogen transformation and removal

    Science.gov (United States)

    Senzia, M. A.; Mashauri, D. A.; Mayo, A. W.

    It is estimated that 90% of sewage in cities in developing countries are today discharged untreated into water bodies. In Tanzania, pollution of rivers such as Karanga, Njoro and Rao in Moshi; Mirongo in Mwanza and Themi in Arusha is the cause of frequent disease outbreaks in communities downstreams. Solutions to effluent crisis can be found by its proper treatment and disposal. The principal objective of wastewater treatment is to allow effluents to be disposed without danger to human health or unacceptable damage to the ecology of receiving water bodies. Field investigations were made on pilot scale horizontal subsurface flow constructed wetlands (CW) units located downstream of waste stabilisation ponds (WSP). Six units filled with gravel of 6-25 mm diameters in equal proportion, which gave an initial hydraulic conductivity of 86 m/d were used. While four units covering surface area of 40.7 m 2 each, were located downstream of primary facultative pond, the other two units with surface area 15.9 m 2 each were located downstream of maturation pond. An attempt was made to compare the output of mathematical models for Phragmites and Typha macrophytes located downstream of primary facultative pond. Based on total inflow nitrogen of 1.457 gN/m 2 d, while Phragmites has shown a removal of 54%, Typha had a removal of 44.2%. Furthermore, while the system downstream of primary facultative pond has accretion as a major pathway, accounting for 19.1% of inflow nitrogen, the system downstream of maturation pond has denitrification as its major removal mechanism accounting for 20.5%. In this paper, a comparison of land required by CW and WSP based on the amount of water to be treated is made.

  1. Long-term olfactory memories are stabilised via protein synthesis in Camponotus fellah ants.

    Science.gov (United States)

    Guerrieri, Fernando J; d'Ettorre, Patrizia; Devaud, Jean-Marc; Giurfa, Martin

    2011-10-01

    Ants exhibit impressive olfactory learning abilities. Operant protocols in which ants freely choose between rewarded and non-rewarded odours have been used to characterise associative olfactory learning and memory. Yet, this approach precludes the use of invasive methods allowing the dissection of molecular bases of learning and memory. An open question is whether the memories formed upon olfactory learning that are retrievable several days after training are indeed based on de novo protein synthesis. Here, we addressed this question in the ant Camponotus fellah using a conditioning protocol in which individually harnessed ants learn an association between odour and reward. When the antennae of an ant are stimulated with sucrose solution, the insect extends its maxilla-labium to absorb the solution (maxilla-labium extension response). We differentially conditioned ants to discriminate between two long-chain hydrocarbons, one paired with sucrose and the other with quinine solution. Differential conditioning leads to the formation of a long-term memory retrievable at least 72 h after training. Long-term memory consolidation was impaired by the ingestion of cycloheximide, a protein synthesis blocker, prior to conditioning. Cycloheximide did not impair acquisition of either short-term memory (10 min) or early and late mid-term memories (1 or 12 h). These results show that, upon olfactory learning, ants form different memories with variable molecular bases. While short- and mid-term memories do not require protein synthesis, long-term memories are stabilised via protein synthesis. Our behavioural protocol opens interesting research avenues to explore the cellular and molecular bases of olfactory learning and memory in ants.

  2. Chemical stabilisation of lead in shooting range soils with phosphate and magnesium oxide: Synchrotron investigation

    Energy Technology Data Exchange (ETDEWEB)

    Sanderson, Peter [Centre for Environmental Risk Assessment and Remediation and CRC for Contamination Assessment and Remediation of the Environment (CRC CARE), University of South Australia, University Parade, 5095 Mawson Lakes (Australia); Naidu, Ravi, E-mail: ravi.naidu@crccare.com [Centre for Environmental Risk Assessment and Remediation and CRC for Contamination Assessment and Remediation of the Environment (CRC CARE), University of South Australia, University Parade, 5095 Mawson Lakes (Australia); Bolan, Nanthi [Centre for Environmental Risk Assessment and Remediation and CRC for Contamination Assessment and Remediation of the Environment (CRC CARE), University of South Australia, University Parade, 5095 Mawson Lakes (Australia); Lim, Jung Eun; Ok, Yong Sik [Korea Biochar Research Center & Department of Biological Environment, Kangwon National University, Chuncheon 200-701 (Korea, Republic of)

    2015-12-15

    Highlights: • Quantitative speciation of Pb by XAS as a result of Phosphate and MgO treatment revealed Pb converted to pyromorphite was limited. • Subsequent MgO addition increased pyromorphite formation. • Pb was precipitated on the surface of MgO as PbO. • Bioaccessibility of Pb decreased with P treatments, but not with MgO only. - Abstract: Three Australian shooting range soils were treated with phosphate and magnesium oxide, or a combination of both to chemically stabilize Pb. Lead speciation was determined after 1 month ageing by X-ray absorption spectroscopy combined with linear combination fitting in control and treated soils. The predominant Pb species in untreated soils were iron oxide bound Pb, humic acid bound Pb and the mineral litharge. Treatment with phosphate resulted in substantial pyromorphite formation in two of the soils (TV and PE), accounting for up to 38% of Pb species present, despite the addition of excess phosphate. In MgO treated soils only, up to 43% of Pb was associated with MgO. Litharge and Pb hydroxide also formed as a result of MgO addition in the soils. Application of MgO after P treatment increased hydroxypyromorphite/pyromorphite formation relative to soils teated with phosphate only. X-ray diffraction and Scanning electron microscopy revealed PbO precipitate on the surface of MgO. Soil pH, (5.3–9.3) was an important parameter, as was the solubility of existing Pb species. The use of direct means of determination of the stabilisation of metals such as by X-ray absorption spectroscopy is desirable, particularly in relation to understanding long term stability of the immobilised contaminants.

  3. Ecotoxicity of chemically stabilised metal(loid)s in shooting range soils.

    Science.gov (United States)

    Sanderson, Peter; Naidu, Ravi; Bolan, Nanthi

    2014-02-01

    Five chemical amendments (soft rock phosphate, lime, commercial phosphate amendment, red mud and magnesium oxide) were applied across four different shooting range soils to chemically stabilise metal(loid)s in the soils. Soils were contaminated with Pb between 2330 and 12,167 mg/kg, Sb from 7.4 to 325 mg/kg and soil pH ranged from 5.43 to 9.29. Amendments were tested for their ability to reduce the bioavailability of Pb, Sb, Zn, Ni, Cu and As in the soils to soil organisms after one year of aging, by measuring a series of ecotoxicological endpoints for earthworms and plants and soil microbial activity. Growth-based endpoints for earthworms and plants were not significantly affected by amendment addition, except in the most contaminated soil. Per cent survival and weight-loss reduction of earthworms was enhanced by amendment addition in only the most contaminated soil. Plant biomass and root elongation was not significantly affected by amendment addition (p=alkaline pH (9-12). Lead in soil organisms was relatively low despite the high concentrations of Pb in the soils, suggesting low bioavailability of Pb. Uptake of Pb by earthworms was reduced by between 40 and 96 per cent by amendments, but not across all soils. Amendments reduced Sb in earthworms in Townsville soil by up to 92 per cent. For lettuce the average uptake of Pb was reduced by 40 to 70 per cent with amendment addition in Townsville, Darwin and Perth soil. The effect of amendments on the uptake of Sb, Zn, Ni, Cu and As was variable between soils and amendments. Microbial activity was increased by greater than 50 per cent with amendments addition, with soft rock phosphate and lime being the most effective in Murray Bridge and TV soils and commercial phosphate and MgO being the most effective in Darwin and Perth soils.

  4. Acetabular Fractures in the Elderly: Midterm Outcomes of Column Stabilisation and Primary Arthroplasty

    Directory of Open Access Journals (Sweden)

    A. Ortega-Briones

    2017-01-01

    Full Text Available Background. Interest in arthroplasty techniques for periarticular or intra-articular fractures in the elderly/osteoporotic patient continues to rise, including for geriatric acetabular fractures. In line with this, many acetabular fracture surgeons are now undertaking acute total hip arthroplasty in elderly/osteoporotic patients. Little is known however of the outcomes of this procedure, beyond the first year after surgery. Questions/Purposes. We determined the clinical outcomes of a series of elderly osteoporotic patients (mean age at surgery 77.4 years treated for acetabular fractures with column fixation and simultaneous total hip arthroplasty, at a mean of 49 months after surgery. Methods. 24 patients (25 hips were reviewed at a mean of 49 months after surgery. The surgical technique employed has previously been described. Radiographs were obtained, and clinical outcomes were assessed using Harris Hip Scores and the Merle d’Aubigné score. Results. 14 hips were available for assessment (9 deceased, 2 lost to follow-up. No patient suffered any complications beyond the perioperative period, no acetabular components were loose clinically or on latest radiographs, and the mean Harris Hip Score was 92. All but one patient scored good or excellent on the Merle d’Aubigné score. Conclusions. Column fixation and simultaneous total hip arthroplasty are a viable option for complex geriatric acetabular fractures, with encouraging midterm results. We conclude that THR is a viable long-term solution in this situation provided that the acetabular columns are stabilised prior to implantation, but more research is needed to aid in overall management decision making.

  5. Mechanisms for stabilisation and the maintenance of solubility in proteins from thermophiles

    Directory of Open Access Journals (Sweden)

    Warwicker Jim

    2007-03-01

    Full Text Available Abstract Background The database of protein structures contains representatives from organisms with a range of growth temperatures. Various properties have been studied in a search for the molecular basis of protein adaptation to higher growth temperature. Charged groups have emerged as key distinguishing factors for proteins from thermophiles and mesophiles. Results A dataset of 291 thermophile-derived protein structures is compared with mesophile proteins. Calculations of electrostatic interactions support the importance of charges, but indicate that increases in charge contribution to folded state stabilisation do not generally correlate with the numbers of charged groups. Relative propensities of charged groups vary, such as the substitution of glutamic for aspartic acid sidechains. Calculations suggest an energetic basis, with less dehydration for longer sidechains. Most other properties studied show weak or insignificant separation of proteins from moderate thermophiles or hyperthermophiles and mesophiles, including an estimate of the difference in sidechain rotameric entropy upon protein folding. An exception is increased burial of alanine and proline residues and decreased burial of phenylalanine, methionine, tyrosine and tryptophan in hyperthermophile proteins compared to those from mesophiles. Conclusion Since an increase in the number of charged groups for hyperthermophile proteins is separable from charged group contribution to folded state stability, we hypothesise that charged group propensity is important in the context of protein solubility and the prevention of aggregation. Accordingly we find some separation between mesophile and hyperthermophile proteins when looking at the largest surface patch that does not contain a charged sidechain. With regard to our observation that aromatic sidechains are less buried in hyperthermophile proteins, further analysis indicates that the placement of some of these groups may facilitate the

  6. High-performance liquid chromatographic analysis of as-synthesised N,N'-dimethylformamide-stabilised gold nanoclusters product

    Science.gov (United States)

    Xie, Shunping; Paau, Man Chin; Zhang, Yan; Shuang, Shaomin; Chan, Wan; Choi, Martin M. F.

    2012-08-01

    Reverse-phase high-performance liquid chromatographic (RP-HPLC) separation and analysis of polydisperse water-soluble gold nanoclusters (AuNCs) stabilised with N,N'-dimethylformamide (DMF) were investigated. Under optimal elution gradient conditions, the separation of DMF-AuNCs was monitored by absorption and fluorescence spectroscopy. The UV-vis spectral characteristics of the separated DMF-AuNCs have been captured and they do not possess distinct surface plasmon resonance bands, indicating that all DMF-AuNCs are small AuNCs. The photoluminescence emission spectra of the separated DMF-AuNCs are in the blue-light region. Moreover, cationic DMF-AuNCs are for the first time identified by ion chromatography. Our proposed RP-HPLC methodology has been successfully applied to separate AuNCs of various Au atoms as well as DMF-stabilised ligands. Finally, the composition of the separated DMF-AuNCs was confirmed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry and electrospray ionisation mass spectrometry, proving that the as-synthesised DMF-AuNCs product consists of Au10+, Au10, Au11, Au12, Au13, and Au14 NCs stabilised with various numbers of DMF ligands.Reverse-phase high-performance liquid chromatographic (RP-HPLC) separation and analysis of polydisperse water-soluble gold nanoclusters (AuNCs) stabilised with N,N'-dimethylformamide (DMF) were investigated. Under optimal elution gradient conditions, the separation of DMF-AuNCs was monitored by absorption and fluorescence spectroscopy. The UV-vis spectral characteristics of the separated DMF-AuNCs have been captured and they do not possess distinct surface plasmon resonance bands, indicating that all DMF-AuNCs are small AuNCs. The photoluminescence emission spectra of the separated DMF-AuNCs are in the blue-light region. Moreover, cationic DMF-AuNCs are for the first time identified by ion chromatography. Our proposed RP-HPLC methodology has been successfully applied to separate AuNCs of

  7. Production and validation of model iron-tannate dyed textiles for use as historic textile substitutes in stabilisation treatment studies

    Directory of Open Access Journals (Sweden)

    Wilson Helen

    2012-05-01

    Full Text Available Abstract Background For millennia, iron-tannate dyes have been used to colour ceremonial and domestic objects shades of black, grey, or brown. Surviving iron-tannate dyed objects are part of our cultural heritage but their existence is threatened by the dye itself which can accelerate oxidation and acid hydrolysis of the substrate. This causes many iron-tannate dyed textiles to discolour and decrease in tensile strength and flexibility at a faster rate than equivalent undyed textiles. The current lack of suitable stabilisation treatments means that many historic iron-tannate dyed objects are rapidly crumbling to dust with the knowledge and value they hold being lost forever. This paper describes the production, characterisation, and validation of model iron-tannate dyed textiles as substitutes for historic iron-tannate dyed textiles in the development of stabilisation treatments. Spectrophotometry, surface pH, tensile testing, SEM-EDX, and XRF have been used to characterise the model textiles. Results On application to textiles, the model dyes imparted mid to dark blue-grey colouration, an immediate tensile strength loss of the textiles and an increase in surface acidity. The dyes introduced significant quantities of iron into the textiles which was distributed in the exterior and interior of the cotton, abaca, and silk fibres but only in the exterior of the wool fibres. As seen with historic iron-tannate dyed objects, the dyed cotton, abaca, and silk textiles lost tensile strength faster and more significantly than undyed equivalents during accelerated thermal ageing and all of the dyed model textiles, most notably the cotton, discoloured more than the undyed equivalents on ageing. Conclusions The abaca, cotton, and silk model textiles are judged to be suitable for use as substitutes for cultural heritage materials in the testing of stabilisation treatments.

  8. Erosion protection comparison of stabilised SnF2 , mixed fluoride active and SMFP/arginine-containing dentifrices.

    Science.gov (United States)

    Eversole, Sandra L; Saunders-Burkhardt, Kymberly; Faller, Robert V

    2014-03-01

    To investigate the relative erosion protection potential of marketed dentifrices formulated with either stabilised stannous fluoride (SnF2 ), sodium fluoride (NaF) and/or sodium monofluorophosphate (SMFP) using an established laboratory erosion cycling model. Sound enamel cores from extracted, human enamel were cleaned, ground and polished, soaked in pooled saliva (pellicle formation) and treated with a 1:3 slurry of dentifrice and saliva. Specimens were subjected to daily challenges with 1% citric acid, a potentially damaging acid found in common food and drinks. Marketed dentifrices compared were: (1) a stabilised stannous fluoride product formulated with 1,100 ppm F as SnF2 ; (2) a cavity protection product containing 1,100 ppm F as NaF; (3) a cavity protection product comprising a mixed active fluoride system with 1,000 ppm F as SMFP + 450 ppm F as NaF; and (4) a sensitivity product containing 1,450 ppm F as SMFP + 8% arginine bicarbonate. Specimens from Group 1 demonstrated an average loss of 5.5 (±1.2) μm of tooth surface enamel; Groups 2, 3 and 4 lost an average of 18.3 (±0.9) μm, 16.0 (±2.0) μm and 17.1 (±1.1) μm, respectively, of tooth surface enamel. Group 1 provided a statistically significant difference in protection compared with the other products. These results suggest that the marketed dentifrice formulated with stabilised SnF2 may provide enhanced protection of exposed tooth surfaces against dietary acid attack compared with the other products tested. © 2014 FDI World Dental Federation.

  9. Phase II study of SPI-77 (sterically stabilised liposomal cisplatin) in advanced non-small-cell lung cancer

    OpenAIRE

    White, S. C.; Lorigan, P; MARGISON, G. P.; Margison, J M; Martin, F.; Thatcher, N.; Anderson, H; Ranson, M.

    2006-01-01

    To determine the efficacy and tolerability of SPI-77 (sterically stabilised liposomal cisplatin) at three dose levels in patients with advanced non-small-cell lung cancer (NSCLC). Patients had Stage IIIB or IV NSCLC and were chemo-naïve, and Eastern Oncology Cooperative Group 0–2. The first cohort received SPI-77 at 100 mg m−2, the second 200 mg m−2 and the final cohort 260 mg m−2. Patients had also pharmacokinetics and analysis of leucocyte platinum (Pt)-DNA adducts performed. Twenty-six pat...

  10. Electrically switchable polymer stabilised broadband infrared reflectors and their potential as smart windows for energy saving in buildings

    Science.gov (United States)

    Khandelwal, Hitesh; Loonen, Roel C. G. M.; Hensen, Jan L. M.; Debije, Michael G.; Schenning, Albertus P. H. J.

    2015-07-01

    Electrically switchable broadband infrared reflectors that are relatively transparent in the visible region have been fabricated using polymer stabilised cholesteric liquid crystals. The IR reflectors can change their reflection/transmission properties by applying a voltage in response to changes in environmental conditions. Simulations predict that a significant amount of energy can be saved on heating, cooling and lighting of buildings in places such as Madrid by using this switchable IR reflector. We have also fabricated a switchable IR reflector which can also generate electricity. These polymer based switchable IR reflectors are of high potential as windows of automobiles and buildings to control interior temperatures and save energy.

  11. Asymptotic stabilisation of the ball and beam system: design of energy-based control law and experimental results

    Science.gov (United States)

    Muralidharan, Vijay; Anantharaman, S.; Mahindrakar, Arun D.

    2010-06-01

    We present a new nonlinear control law to stabilise the ball and beam system at a desired operating point. The control law is based on the interconnection and damping assignment-passivity-based control (IDA-PBC) methodology developed in Ortega, Spong, Gomez-Estern, and Blankenstien (Ortega, R., Spong, M., Gomez-Estern, F., and Blankenstien, G. (2002), 'Stabilization of Underactuated Mechanical Systems via Interconnection and Damping Assignment', IEEE Transactions on Automatic Control, 47, 1218-1233) that guarantees stability in the sense of Lyapunov. We present a novel proof of the asymptotic stability of the desired operating point. The validity of the proposed control law is demonstrated through the experimental results.

  12. Embolisation of pheochromocytoma to stabilise and wean a patient in cardiogenic shock from emergency extracorporeal life support.

    Science.gov (United States)

    Vagner, Helle; Hey, Thomas Morris; Elle, Bo; Jensen, Marianne Kjær

    2015-03-03

    Pheochromocytoma is a catecholamine-secreting tumour associated with varying symptoms ranging from episodic headache, sweating, paroxysmal hypertension and tachycardia to intractable cardiogenic shock. Cardiogenic shock is rare but well-described and the timing of correct management is crucial since mortality is high. Fifty per cent of pheochromocytomas are diagnosed on autopsy. We report on a case of embolisation of the adrenal artery during ongoing extracorporeal life support (ECLS) in order to stabilise and wean the patient from ECLS as a bridge to final surgery.

  13. O/W emulsions stabilised by both low molecular weight surfactants and colloidal particles: The effect of surfactant type and concentration.

    Science.gov (United States)

    Pichot, R; Spyropoulos, F; Norton, I T

    2010-12-01

    The stability against coalescence of O/W emulsions in the presence of both surfactants and colloidal particles was investigated. In particular the effect of the surfactant type and concentration in these emulsifier mixtures on the O/W emulsions' stability was studied. Two types of surfactants were selected; those that have the ability to stabilise O/W emulsions on their own (O/W surfactants) and those that cannot (W/O surfactants). Tween 60 and Sodium Caseinate were selected as the O/W surfactants and lecithin as the W/O surfactant. Oil-in-water emulsions prepared with both particles and any of the three surfactants were stable against coalescence but, depending on the type of surfactant, the behaviour of the systems was found to depend on surfactant concentration. The droplet sizes of emulsions stabilised by mixed emulsifier systems containing low concentrations of O/W surfactants (Tween 60 or Sodium Caseinate) were smaller than those solely stabilised by either the surfactant or particles alone. At intermediate O/W surfactants concentrations, the droplet sizes of the emulsions increased. Further increases in the O/W surfactants' concentration, resulted in the complete removal of particles from the interface with the system now behaving as a surfactant-only stabilised emulsion. The behaviour of emulsions stabilised by emulsifier mixtures containing W/O surfactants was not dependent on the concentration of surfactant: no removal of particles was observed. Copyright © 2010 Elsevier Inc. All rights reserved.

  14. Effect of saliva stabilisers on detection of porcine reproductive and respiratory syndrome virus in oral fluid by quantitative reverse transcriptase real-time PCR.

    Science.gov (United States)

    Decorte, Inge; Van der Stede, Yves; Nauwynck, Hans; De Regge, Nick; Cay, Ann Brigitte

    2013-08-01

    This study evaluated the effect of extraction-amplification methods, storage temperature and saliva stabilisers on detection of porcine reproductive and respiratory syndrome virus (PRRSV) RNA by quantitative reverse transcriptase real-time PCR (qRT-PCR) in porcine oral fluid. The diagnostic performance of different extraction-amplification methods was examined using a dilution series of oral fluid spiked with PRRSV. To determine RNA stability, porcine oral fluid, with or without commercially available saliva stabilisers, was spiked with PRRSV, stored at 4°C or room temperature and tested for the presence of PRRSV RNA by qRT-PCR. PRRSV RNA could be detected in oral fluid using all extraction-amplification combinations, but the limit of detection varied amongst different combinations. Storage temperature and saliva stabilisers had an effect on the stability of PRRSV RNA, which could only be detected for 7 days when PRRSV spiked oral fluid was kept at 4°C or stabilised at room temperature with a commercial mRNA stabiliser.

  15. Anatase-stabilised AlxTi1-xO2 photoanodes containing uniform spherical particles for efficient dye-sensitized solar cells

    Science.gov (United States)

    Bakhshayesh, A. M.; Farajisafiloo, N.

    2015-03-01

    This paper reports a facile straightforward process for the deposition of uniform photoanode electrodes by a novel AlxTi1-xO2 gel for dye-sensitized solar cells (DSCs) applications. Highly crystalline anatase-TiO2 phase is stabilised by aluminium chloride at 500 °C. The electrodes are composed of uniform spherical particles with diameter around 3 μm, containing small nanoparticles with the average grain size of 40 nm, deposited by dip coating method. X-ray photoelectron spectroscopy (XPS) reveals that 0.5 at.% Al3+ was incorporated into titania crystal lattice and stabilised anatase phase by limiting the transformation from anatase to rutile phase. UV-vis spectra show that the stabilised-film has lower band gap energy than that of undoped-TiO2, extending the absorption of TiO2 into visible region. Electrochemical impedance spectroscopy (EIS) demonstrates that the anatase-stabilised DSC enjoys less recombination and internal resistances, improving the photovoltaic performance of the cell. The anatase-stabilised DSC has higher power conversion efficiency of 7.52% than that of unstabilised cell (6.40%).

  16. Numerical study of viscoelastic polymer flow in simplified pore structures using stabilised finite element model

    Energy Technology Data Exchange (ETDEWEB)

    Qi, M.; Wegner, J.; Ganzer, L. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). ITE

    2013-08-01

    Polymer flooding, as an EOR method, has become one of the most important driving forces after water flooding. The conventional believe is that polymer flooding can only improve sweep efficiency, but it has no contribution to residual oil saturation reduction. However, experimental studies indicated that polymer solution can also improve displacement efficiency and decrease residual oil saturation. To get a better understanding of the mechanism to increase the microscopic sweep efficiency and the displacement efficiency, theoretical studies are required. In this paper, we studied the viscoelasticity effect of polymer by using a numerical simulator, which is based on Finite Element Analysis. Since it is showed experimentally that the first normal stress difference of viscoelastic polymer solution is higher than the second stress difference, the Oldroyd-B model was selected as the constitutive equation in the simulation. Numerical modelling of Oldroyd-B viscoelastic fluids is notoriously difficult. Standard Galerkin finite element methods are prone to numerical oscillations, and there is no convergence as the elasticity of fluid increases. Therefore, we use a stabilised finite element model. In order to verify our model, we first built up a model with the same geometry and fluid properties as presented in literature and compared the results. Then, with the tested model we simulated the effect of viscoelastic polymer fluid on dead pores in three simplified pore structures, which are contraction structure, expansion structure and expansion-contraction structure. Correspondingly, the streamlines and velocity contours of polymer solution, with different Reynolds numbers (Re) and Weissenberg numbers (We), flowing in these three structures are showed. The simulation results indicate that the viscoelasticity of polymer solution is the main contribution to increase the micro-scale sweep efficiency. With higher elasticity, the velocity of polymer solution is getting bigger at

  17. A Decontamination Process to Remove Metals and Stabilise Montreal Sewage Sludge

    Directory of Open Access Journals (Sweden)

    G. Mercier

    2002-01-01

    Full Text Available The Montreal Urban Community (MUC treatment plant produces approximately 270 tons of dry sludge daily (tds/day during physicochemical wastewater treatment. The sludges are burned and contribute to the greenhouse effect by producing atmospheric CO2. Moreover, the sludge emanates a nauseating odour during its thermal stabilisation and retains unpleasant odours for the part (25% that is dried and granulated. To solve this particular problem, the treatment plant authorities are currently evaluating an acidic chemical leaching (sulfuric or hydrochloric acid process at a pH between 2 and 3, using an oxidizing agent such as ferric chloride or hydrogen peroxide (METIX-AC technology, patent pending; [20]. They could integrate it to a 70 tds/day granulated sludge production process. Verification of the application of METIX-AC technology was carried out in a pilot plant set up near the sludge production plant of the MUC. The tests showed that METIX-AC technology can be advantageously integrated to the process used at the MUC. The residual copper (274 ± 58 mg/kg and cadmium (5.6 ± 2.9 mg/kg concentrations in the treated sludge meet legislation standards. The results have also shown that odours have been significantly eliminated for the dewatered, decontaminated, and stabilized biosolids (> 97% compared to the non-decontaminated biosolids. A high rate of odour elimination also was obtained for the liquid leached biosolids (> 93%, compared to the untreated liquid biosolids. The fertilising value (N and P is well preserved by the METIX-AC process. Dissolved organic carbon measurements have showed that little organic matter is brought in solution during the treatment. In fact, the average concentration of dissolved organic carbon measured in the treated liquid phase is 966 ± 352 mg/l, whereas it is 1190 ± 325 mg/l in untreated sludge. The treated sludge was first conditioned with an organic polymer and a coagulant aid. It was successfully dewatered with

  18. Thermal stability of platinum, palladium and silver films on yttrium-stabilised zirconia

    Energy Technology Data Exchange (ETDEWEB)

    Beck, Gesa, E-mail: gesa.beck@physik.uni-augsburg.de [Chair of Resource Strategy, Institute of Physics, University Augsburg, Universitaetsstrasse 1a, 86159 Augsburg (Germany); Bachmann, Christoph [Institute of Physical Chemistry, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 58, 35392 Giessen (Germany); Bretzler, Rita [Research Institute Precious Metals and Metals Chemistry, Katharinenstrasse 17, 73525 Schwaebisch Gmuend (Germany); Kmeth, Ralf [Chair of Resource Strategy, Institute of Physics, University Augsburg, Universitaetsstrasse 1a, 86159 Augsburg (Germany)

    2014-12-31

    Platinum, palladium and silver films with different microstructures have been prepared on differently orientated yttrium-stabilised zirconia (YSZ) substrates by pulsed laser deposition and then annealed at temperatures between 200 °C and 850 °C. Thereby, an influence of the type of metal, of the microstructure of the as-prepared film and of the orientation of the substrate on the annealing behaviour could be determined. The following annealing effects were observed for platinum, palladium and silver films: i) sharpening of the film boundary, ii) smoothing of the film surfaces, iii) sharpening of the texture [thereby: reduction of the fraction of small angle and twin grain boundaries], iv) grain growth and accordingly reduction of the fraction of grains as well as v) grooving at grain boundaries, vi) void formation at the metal|YSZ-interface, vii) hole formation within the films and viii) reduction of the fraction of droplets. In the case of palladium films also ix) oxidation [between 300 °C ≤ T < 750 °C] and stronger de-wetting phenomena than for platinum [with x) waving of the film and xi) island formation at T ≥ 750 °C] have been found. Silver films are not oxidised, but show stronger de-wetting phenomena than platinum and palladium, with xi) island formation and xii) evaporation of the silver at T ≥ 550 °C. Interestingly, silver films on (111) orientated YSZ are thermally much more stable than silver films on the other orientated substrates up to 750 °C. The annealing effects were described by interface, grain boundary and surface energy minimization. - Highlights: • The thermal stability of Pt, Pd and Ag films has been investigated up to 850 °C. • Annealing effects are e.g. reduction of the fraction of twins and island formation. • Pd is also oxidised between 300 °C ≤ T < 750 °C. • Annealing effects depend on type of metal and on its initial microstructure. • Annealing effects depend also on the orientation of substrate.

  19. 椎弓根钉棒系统固定治疗齿状突骨折合并寰枢关节不稳%Transpedicular Screw Fixation System for the Treatment of Dens Fracture Complicated with Atlantoaxial Instability

    Institute of Scientific and Technical Information of China (English)

    张毅; 黄象望; 沈雄杰; 常磊

    2011-01-01

    [Objective]To explore the method and efficacy of transpedicular screw fixation system for the treatment of traumatic axial dentoid process fracture complicated with atlantoaxial instability.[Methods]Twenty six adult cases of acute axial dentoid process fracture complicated with atlantoaxial instability from Dec.2005 to April 2010 were reviewed.Among all the cases, 18 cases were male and 8 cases were female.According to Anderson-D' Alonzo typing method modified by Grauer, 5 cases were type Ⅱ A, and 12 cases were type Ⅱ B, and 6 cases were type Ⅱ C, and 3 cases were type Ⅲ.Three cases were accompanied by spinal injury including 2 cases with type Ⅱ B and one case with type Ⅱ C.All cases were complicated with atlantoaxial instability.At first, all the cases underwent skull traction for atlantoaxial reduction, and then were fixed with atlantoaxial pedicle screw system by cervical posterior approach under general anesthesia.Of all cases, 19 cases underwent autologous iliac bone graft and 7 cases underwent atlantoaxial pedicle screw fixation.The surgical efficacy was assessed by JOA scores before and after operation.[Results]No vertebral artery or spinal injury occurred during operation.Mean time of follow-up was 12 months(8~25 months).Cervicobrachialgia in all patients was alleviated.Three cases with spinal injury had the recovery of neurological function to some ex tent.The imaging data of all cases showed that the atlantoaxial anatomic relationship recovered well and pedicle screws were in a proper position without postoperative loosening or breaking.The bony fusion was obtained in 19 cases undergoing bone graft at 6 months of follow up.The internal fixation system was removed in 7 ca ses without bone graft after one and a half years.Atlantoaxial rotational function was restored satisfactorily.[Conclusion]Atlantoaxial pedicle screw fixation for the treatment of traumatic axial dentoid process fracture complicated with atlantoaxial instability is a solid

  20. Stabilised dG-FEM for incompressible natural convection flows with boundary and moving interior layers on non-adapted meshes

    CERN Document Server

    Schroeder, Philipp W

    2016-01-01

    This paper presents heavily grad-div and pressure jump stabilised, equal- and mixed-order discontinuous Galerkin finite element methods for non-isothermal incompressible flows based on the Oberbeck-Boussinesq approximation. In this framework, the enthalpy-porosity model for multiphase flow in melting and solidification problems can be employed. By considering the differentially heated cavity and the melting of pure gallium in a rectangular enclosure, it is shown that both boundary layers and sharp moving interior layers can be handled naturally by the proposed class of non-conforming methods. Due to the stabilising effect of the grad-div term and the robustness of discontinuous Galerkin methods, it is possible to solve the underlying problems accurately on coarse, non-adapted meshes. The interaction of heavy grad-div stabilisation and discontinuous Galerkin methods significantly improves the mass conservation properties and the overall accuracy of the numerical scheme which is observed for the first time. Hen...

  1. The clinical research of posterior transpedicular screw fixation combined with intervertebral bone grafting fusion in the treatment of Ⅱ degree and Ⅲ degree lumbar spondylolisthesis%后路椎弓根螺钉内固定联合椎间植骨融合治疗Ⅱ、Ⅲ度腰椎滑脱的临床研究

    Institute of Scientific and Technical Information of China (English)

    宁凯; 车立新; 王志刚; 李坤; 吉喆

    2012-01-01

    目的 探讨后路椎弓根螺钉内固定联合椎间植骨融合治疗Ⅱ、Ⅲ度腰椎滑脱临床疗效.方法 回顾性分析我院2009年1月~2011年1月收治入院的30例腰椎滑脱症患者临床资料,所有病例均为Ⅱ、Ⅲ度腰椎滑脱.患者均采用后路椎弓根螺钉内固定联合椎间植骨融合治疗,观察手术前后临床症状及滑脱恢复情况、术后复位、疗效评价、材料生物相容性、术后椎间隙高度及BFS评分.结果 30例患者术前均为Ⅱ、Ⅲ度腰椎滑脱,其中,19例行椎管、神经根管减压、复位固定、植骨融合治疗,11例只行复位固定、植骨融合治疗.获得随访30例,均超过12个月.30例椎间植骨全部融合,融合率为100%.BFS评分优良率达90.0%.结论 后路椎弓根螺钉内固定联合椎间植骨融合治疗Ⅱ、Ⅲ度腰椎滑脱,操作简便、固定可靠,是临床治疗中的一种值得推广的方法.%Objective To explore the curative effect of posterior transpedicular screw fixation combined with intervertebral bone grafting fusion in the treatment of Ⅱ degree and Ⅲ degree lumbar spondylolisthesis. Methods The clinical data of 30 patients with lumbar spondylolisthesis from January 2009 to January 2011 in our hospital were analyzed retrospectively. All cases were suffered with Ⅱ degree or Ⅲ degree lumbar spondylolisthesis. All patients were adopted posterior transpedicular screw fixation combined with intervertebral bone grafting fusion treatment. The clinical symptoms, slippage recovery condition before and after operation, postoperative restoration, therapeutic effect evaluation, material biocompatibility, postoperative intervertebral height and BFS score were observed. Results 30 patients all suffered with Ⅱ degree or Ⅲ degree lumbar spondylolisthesis before surgery, among whom 19 cases were treated with canalis vertebralis and nerve root canal decompression, reduction and fixation and bone graft fusion. Other 11 cases were

  2. Birch Bark Dry Extract by Supercritical Fluid Technology: Extract Characterisation and Use for Stabilisation of Semisolid Systems

    Directory of Open Access Journals (Sweden)

    Markus Armbruster

    2017-03-01

    Full Text Available Triterpene compounds like betulin, betulinic acid, erythrodiol, oleanolic acid and lupeol are known for many pharmacological effects. All these substances are found in the outer bark of birch. Apart from its pharmacological effects, birch bark extract can be used to stabilise semisolid systems. Normally, birch bark extract is produced for this purpose by extraction with organic solvents. Employing supercritical fluid technology, our aim was to develop a birch bark dry extract suitable for stabilisation of lipophilic gels with improved properties while avoiding the use of toxic solvents. With supercritical carbon dioxide, three different particle formation methods from supercritical solutions have been tested. First, particle deposition was performed from a supercritical solution in an expansion chamber. Second, the Rapid Expansion of Supercritical Solutions (RESS method was used for particle generation. Third, a modified RESS-procedure, forming the particles directly into the thereby gelated liquid, was developed. All three methods gave yields from 1% to 5.8%, depending on the techniques employed. The triterpene composition of the three extracts was comparable: all three gave more stable oleogels compared to the use of an extract obtained by organic solvent extraction. Characterizing the rheological behaviour of these gels, a faster gelling effect was seen together with a lower concentration of the extract required for the gel formation with the supercritical fluid (SCF-extracts. This confirms the superiority of the supercritical fluid produced extracts with regard to the oleogel forming properties.

  3. Neutron and X-ray diffraction and empirical potential structure refinement modelling of magnesium stabilised amorphous calcium carbonate

    DEFF Research Database (Denmark)

    Cobourne, G.; Mountjoy, G.; Rodriguez Blanco, Juan Diego

    2014-01-01

    from CO3 molecules and 0.6 oxygen atoms from H2O molecules. The average CaO bond length is 2.40 Å. The distribution of Ca in the model is homogeneous with a uniformly distributed Ca-rich network and no evidence of the Ca-poor channels as previously reported for a reverse Monte Carlo model of ACC......Amorphous calcium carbonate (ACC) plays a key role in biomineralisation processes in sea organisms. Neutron and X-ray diffraction have been performed for a sample of magnesium-stabilised ACC, which was prepared with a Mg:Ca ratio of 0.05:1 and 0.25 H2O molecules per molecule of CO3. The empirical...... potential structure refinement method has been used to make a model of magnesium-stabilised ACC and the results revealed a fair agreement with the experimental diffraction data. The model has well-defined CO3 and H2O molecules. The average coordination number of Ca is 7.4 and is composed of 6.8 oxygen atoms...

  4. Alkali activated solidification/stabilisation of air pollution control residues and co-fired pulverised fuel ash.

    Science.gov (United States)

    Shirley, Robin; Black, Leon

    2011-10-30

    This paper examines the potential treatment by solidification/stabilisation (S/S) of air pollution control (APC) residues using only waste materials otherwise bound for disposal, namely a pulverised fuel ash (PFA) from a co-fired power station and a waste caustic solution. The use of waste materials to stabilise hazardous wastes in order to meet waste acceptance criteria (WAC) would offer an economical and efficient method for reducing the environmental impact of the hazardous waste. The potential is examined against leach limits for chlorides, sulphates and total dissolved solids, and compressive strength performance described in the WAC for stable non-reactive (SNR) hazardous waste landfill cells in England and Wales. The work demonstrates some potential for the treatment, including suitable compressive strengths to meet regulatory limits. Monolithic leach results showed good encapsulation compared to previous work using a more traditional cement binder. However, consistent with previous work, SNR WAC for chlorides was not met, suggesting the need for a washing stage. The potential problems of using a non-EN450 PFA for S/S applications were also highlighted, as well as experimental results which demonstrate the effect of ionic interactions on the mobility of phases during regulatory leach testing.

  5. [Interactions between cyclodextrins and triglycerides: from emulsion stabilisation to the emergence of a new drug delivery system called "beads"].

    Science.gov (United States)

    Hamoudi, M; Trichard, L; Grossiord, J-L; Chaminade, P; Duchêne, D; Le Bas, G; Fattal, E; Bochot, A

    2009-11-01

    Natural cyclodextrins are cyclic oligosaccharides which can be modified to obtain more water soluble or insoluble derivatives. The main interest of cyclodextrins results from their ability to form an inclusion complex with hydrophobic molecules. Inclusion constitutes a true molecular encapsulation. This property is employed in pharmaceutical industry to facilitate the formulation of poorly water soluble and/or fragile drugs. A more recent application of cyclodextrins consists in their use in the preparation of dispersed systems such as micro- and nanoparticles or even liposomes. When incorporated in dispersed systems, cyclodextrin can enhance drug solubility, drug stability and drug loading. Interestingly, cyclodextrins themselves can also be employed to form or stabilise dispersed systems (material or emulsifying agent). For example, the interactions between cyclodextrins with components of the vegetable oils (more especially with triglycerides) allow to stabilise simple or multiple emulsions but also to form particles called "beads". Very rich in oil, this novel lipid carrier presents an important potential for the encapsulation of highly lipophilic compounds and their delivery by topical and oral routes. These two applications are more particularly developed in the present paper.

  6. Comparative antibacterial activity of silver nanoparticles synthesised by biological and chemical routes with pluronic F68 as a stabilising agent.

    Science.gov (United States)

    Santos, Carolina Alves Dos; Seckler, Marcelo Martins; Ingle, Avinash P; Rai, Mahendra

    2016-08-01

    The authors report the comparative antibacterial activity of silver nanoparticles synthesised by biological (using Fusarium oxysporum) and chemical routes in the presence and absence of pluronic F68 as a stabilising agent. The production of silver nanoparticles was evidenced by UV-visible spectra, with absorbance at about 420 nm in the case of both biological and chemical synthesis. X-ray diffraction pattern confirmed the presence of face-centred cubic structure (FCC plane). The nanoparticles characterised by transmission and scanning electron microscopy showed spherical silver nanoparticles with size range of 5-40 and 10-70 nm in the case of biologically and chemically synthesised nanoparticles, respectively. Addition of pluronic F68 showed the stabilisation of silver nanoparticles. Antibacterial efficacy of silver nanoparticles demonstrated different inhibitory activity against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. Overall, biologically synthesised silver nanoparticles showed higher activity as compared with chemically synthesised nanoparticles. Silver nanoparticles synthesised in the presence of pluronic F68 by the chemical route exhibited synergism in antibacterial activity as compared with those synthesised without pluronic F68. On the contrary, biogenic silver nanoparticles without pluronic F68 showed higher antibacterial potential.

  7. Laser frequency stabilisation via quasi-monolithic, unequal arm-length Mach-Zehnder interferometer with balanced DC readout

    CERN Document Server

    Gerberding, Oliver; Mehmet, Moritz; Danzmann, Karsten; Heinzel, Gerhard

    2016-01-01

    Low frequency high precision laser interferometry is subject to excess laser frequency noise coupling via arm-length differences which is commonly mitigated by locking the frequency to a stable reference system. This is crucial to achieve picometer level sensitivities in the 0.1 mHz to 1 Hz regime, where laser frequency noise is usually high and couples into the measurement phase via arm-length mismatches in the interferometers. Here we describe the results achieved by frequency stabilising an external cavity diode laser to a quasi-monolithic unequal arm-length Mach-Zehnder interferometer read out at mid-fringe via balanced detection. This stabilisation scheme has been found to be an elegant solution combining a minimal number of optical components, no additional laser modulations and relatively low frequency noise levels. The Mach-Zehnder interferometer has been designed and constructed to minimise the influence of thermal couplings and to reduce undesired stray light using the optical simulation tool IfoCAD...

  8. Bioavailability of stabilised ferrous gluconate with glycine in fresh cheese matrix: a novel iron compound for food fortification.

    Science.gov (United States)

    Pizarro, Fernando; Boccio, José; Salgueiro, María; Olivares, Manuel; Carmuega, Esteban; Weill, Ricardo; Marque, Sebastien; Frereux, Marine; Noirt, Florence

    2013-03-01

    Iron fortification of foods continues to be one of the preferred ways of improving the iron status of the population. Dairy product is a common product in the diet; therefore, it is a plausible vehicle for iron fortification. This study aims to investigate the bioavailability of ferrous gluconate stabilised with glycine (FGSG) in a fresh cheese fortified with zinc. The iron bioavailability of fresh cheese fortified with either FGSG and with or without zinc and FGSG in aqueous solution and a water solution of ferrous ascorbate (reference dose) was studied using double radio iron ((55)Fe and (59)Fe) erythrocyte incorporation in 15 male subjects. All subjects presented with normal values for iron status parameters. The geometric mean of iron bioavailability for the water solution of FGSG was 38.2 %, adjusted to 40 % from reference doses (N.S.). Iron bioavailability in fresh cheese fortified with Ca and Zn was 15.4 % and was 23.1 % without Zn, adjusted to 40 % from reference doses (N.S.). The results of the present study show that the novel iron compound ferrous gluconate stabilised with glycine in a fresh cheese matrix is a good source of iron and can be used in iron fortification programmes.

  9. Treatment effect on signs and symptoms of temporomandibular disorders--comparison between stabilisation splint and a new type of splint (NTI). A pilot study.

    Science.gov (United States)

    Magnusson, Tomas; Adiels, Anne-Marie; Nilsson, Håkan L; Helkimo, Martti

    2004-01-01

    The aim of the investigation was to compare the effect on signs and symptoms of temporomandibular disorders (TMD) of two different interocclusal appliances. Thirty patients with signs and symptoms of TMD received either a stabilisation splint or a new kind of splint based on the concept of nociceptive trigeminal inhibition (NTI). A clinical examination was performed and subjective symptoms were registered before start of treatment and after 3 and 6 months. All participants were offered to change to the other type of splint at the 3-month follow-up in case of no improvement or impairment of their symptoms. One subject in each group was lost early during the investigation. The mean time for taking impressions, to make inter-occlusal recording and to adjust the stabilisation splints was 17 minutes. The mean time to fit and adjust the NTI splints was 27 minutes. At the 3-month follow-up, 4 patients that had received NTI splints accepted the offer to change to stabilisation splints due to no improvement or impairment of their symptoms. These treatments were judged as failures. No one in the stabilisation splint group utilised the offer to change treatment. At the 6-month follow-up, 7 of the remaining 10 subjects with NTI splints reported some (n = 1) or significant (n = 6) improvement, 2 reported no change and one reported impairment. All 14 who had been treated with a stabilisation splint reported some (n = 2) or significant (n = 12) improvement. For all variables registered, the results were in favour for the stabilisation splint. One subject treated with a NTI splint exhibited an impaired occlusion at the 6-month follow-up.

  10. Voltage-stabilised elastomers with increased relative permittivity and high electrical breakdown strength by means of phase separating binary copolymer blends of silicone elastomers

    DEFF Research Database (Denmark)

    A Razak, Aliff Hisyam; Yu, Liyun; Skov, Anne Ladegaard

    2017-01-01

    Increased electrical breakdown strength and increased dielectric permittivity of silicone-based dielectric elastomers are achieved by means of the addition of so-called voltage-stabilisers prepared from PDMS–PPMS copolymers as well as PDMS–PEG copolymers in order to compensate for the negative...... effect of softness on electrical stability of silicone elastomers. The voltage-stabilised elastomer, incorporating a high-permittivity PDMS–PEG copolymer, possesses increased relative permittivity, high electrical breakdown strength, excellent network integrity and low dielectric loss and paves the way...... towards specialised silicone elastomers for dielectric elastomer transducer products with inherent softness and electrical stability, and thus increased actuation at a given voltage....

  11. Clinical efficacies of transpedicular bivertebral osteotomy for correction of severe kyphosis in ankylosing spondylilis patients%经椎弓根双椎体截骨术治疗重度强直性脊柱炎后凸畸形的临床疗效

    Institute of Scientific and Technical Information of China (English)

    伍佳剑; 马华松; 王蒙; 周雪峰; 彭军

    2014-01-01

    背景:经椎弓跟双椎体截骨治疗重度强直性脊柱炎后凸畸形能够很好地恢复矢状位平衡,术后效果明显,但缺乏临床随访观察研究。  目的:探讨重度强直性脊柱炎后凸畸形经椎弓根双椎体截骨术治疗的临床疗效。  方法:回顾性分析2009年1月至2011年12月行经椎弓根双椎体截骨术治疗的34例强直性脊柱炎重度后凸畸形患者的临床资料。男22例,女12例;年龄23~62岁,平均(38.3±9.6)岁。统计测量患者术前、术后身高,X线片的矢状面平衡参数,如颌眉角、胸椎后凸角、腰椎前凸、脊柱整体后凸角等。  结果:本组患者身高术前为(125.3±7.8)cm,术后为(165.4±10.3)cm;颌眉角术前为92.4°±8.3°,术后为13.2°±11.9°;胸椎后凸角术前为72.3°±14°,术后为63.4°±11.5°;腰椎前凸角术前为-30°±20.3°,术后为29.0°±13.1°;脊柱整体后凸角术前为100.4°±19.3°,术后为26.4°±12.4°;C7铅垂线与骶骨后上角之间的垂直距离术前为(50.3±13.4)cm,术后为(15.4±7.2)cm。上述指标术前与术后比较差异均有统计学意义(P<0.05),末次随访与术后比较差异无统计学意义(P>0.05)。SRS-22评分术前为(4.0±0.4)分,术后为(1.6±0.2)分,术前与术后比较差异有统计学意义(P<0.05)。末次随访时所有患者均无内固定断裂、脱出,均达骨性融合。  结论:对于重度强直性脊柱炎后凸畸形,经椎弓根双椎体截骨术是一种安全、有效的术式,具有良好的临床效果。%Background:Transpedicular bivertebral osteotomy for correction of severe kyphosis in ankylosing spondylilis patients can achieve a good sagittal balance, but clinical follow-up study is insufficient. Objective:To explore efficacies of transpedicular bivertebral osteotomy in correction of severe kyphotic deformity in anky-losing spondylitis patients

  12. Thermal decomposition of phase-stabilised ammonium nitrate (PSAM), HTPB based propellants. The effect of iron(III)oxide burning-rate catalyst

    NARCIS (Netherlands)

    Carvalheira, P.; Gadiot, G.M.H.J.L.; Klerk, W.P.C. de

    1995-01-01

    Phase-stabilised ammonium nitrate (PSAN) and hydroxyl-terminated polybutadiene (HTPB) are the main ingredients of propellants used with success in some pyrotechnic igniter components of the VULCAIN liquid rocket engine for the ARIANE 5. Small amounts of selected additives play an important role in s

  13. The Use of the String of Pearls Locking Plate System in the Stabilisation of a Comminuted Calcaneal Fracture in a Giant Breed Dog

    Directory of Open Access Journals (Sweden)

    A. B. Scrimgeour

    2011-01-01

    Full Text Available An eight-year-old male Pyrenean mountain dog was presented with a comminuted fracture of the right calcaneus following motor vehicle trauma. The fracture was stabilised with a plate-rod construct, using the String of Pearls locking plate system and an intramedullary pin. Healing was uncomplicated.

  14. Decentralised adaptive output feedback stabilisation for stochastic time-delay systems via LaSalle-Yoshizawa-type theorem

    Science.gov (United States)

    Jiao, Ticao; Xu, Shengyuan; Lu, Junwei; Wei, Yunliang; Zou, Yun

    2016-01-01

    This paper deals with the decentralised output feedback stabilisation problem for a class of large-scale stochastic time-delay nonlinear systems. A general theorem is firstly given to guarantee the global existence and uniqueness of the solution for stochastic time-delay systems. In addition, a stochastic version of the well-known LaSalle-Yoshizawa theorem with time-varying delay is initially proposed for the controller design and stability analysis. Then, for a class of large-scale stochastic systems with time-varying delays, totally decentralised adaptive delay-dependent controllers are designed by using K-filter and backstepping approach. Via LaSalle-Yoshizawa-type theorem and constructing a general Lyapunov function, it is shown that all signals in the closed-loop system are bounded almost surely and the solution is almost surely asymptotically stable. Finally, a simulation example is given to illustrate the effectiveness of the results of this paper.

  15. Chemical torrefaction as an alternative to established thermal technology for stabilisation of sugar cane bagasse as fuel.

    Science.gov (United States)

    Valix, M; Katyal, S; Cheung, W H

    2016-10-11

    Dry and chemical torrefaction of sugar cane bagasse was examined in this study with the aim of stabilising and upgrading the fuel properties of bagasse. Dry torrefaction was conducted at temperatures from 160°C to 300°C under inert conditions, whilst chemical torrefaction incorporated a H2SO4 pre-treatment of bagasse. Chemical torrefaction imparted superior chemical and physical properties inducing morphological transformation and textural development with the potential to address issues in handling, feeding and processing bagasse. It increased the energy density of the chars with maximum HHVmass 21.5 MJ/kg and maximum HHVvolume of 7.4 GJ/m(3). Chemically torrefied bagasse demonstrated resistance against microbiological attack for 18 months. These features demonstrate the practical value of chemical torrefaction in advancing the utilisation of bagasse as fuel.

  16. Twenty years' monitoring of Mèze stabilisation ponds: part I--Removal of organic matter and nutrients.

    Science.gov (United States)

    Picot, B; Andrianarison, T; Gosselin, J P; Brissaud, F

    2005-01-01

    The Mèze stabilisation pond system has been monitored over more than 20 years. Despite the enlargement of the plant, the organic load doubled between the early 1980s and recent years, the removal of organic matter and nutrients has been maintained at the same level for COD and increased for BOD5, N and P. Combining anaerobic, step-fed aerated and maturation ponds and multiplying the number of cells resulted in a significant improvement in the performances of the plant. Respectively 34, 24 and 23% of the applied COD was eliminated in the anaerobic, the step-fed and the first three maturation ponds, while the figures for BOD5 were 47, 26, and 19% respectively. 38% of the applied nitrogen was eliminated in the first three maturation ponds. Nitrification and denitrification seem to be a major process of nitrogen removal in warm periods. Most of the phosphorus removal was observed to take place in the two polishing ponds.

  17. Contrasting the beam interaction characteristics of selected lasers with a partially stabilised zirconia (PSZ) bio-ceramic

    OpenAIRE

    Lawrence, Jonathan

    2002-01-01

    Differences in the beam interaction characteristics of a CO2 laser, a Nd:YAG laser, a high power diode laser (HPDL) and an excimer laser with a partially stabilised zirconia (PSZ) bio-ceramic have been studied. A derivative of Beer-Lambert’s law was applied and the laser beam absorption lengths of the four lasers were calculated as 33.55 x 10-3 cm for the CO2 laser, 18.22 x 10-3 cm for the Nd:YAG laser, 17.17 x 10-3 cm for the HPDL and 8.41 x 10-6 cm for the excimer laser. It was determined g...

  18. Three-year performance of in-situ solidified/stabilised soil using novel MgO-bearing binders.

    Science.gov (United States)

    Jin, Fei; Wang, Fei; Al-Tabbaa, Abir

    2016-02-01

    A new group of MgO-bearing binders has been developed recently which showed improved sustainability and technical performance compared to Portland cement (PC). However, the application of these MgO-bearing binders in the Solidification/Stabilisation (S/S) techniques is very limited. This study investigates the three-year performance of a highly contaminated soil treated by in-situ S/S using MgO-bearing binders and PC. The core quality, strength, permeability and the leaching properties of the S/S materials were evaluated. The effects of binder composition, addition of inorgano-organo-clay (IOC) and the grout content on the properties of the 3-y S/S materials are discussed. It is found that although MgO alone provided negligible strength to the soil, it is superior in immobilising both inorganic and organic contaminants. Replacing MgO by ground granulated blast-furnace slag (GGBS) significantly enhanced the strength while also performed well in immobilising the contaminants. The improved pH buffering capacity was attributed to the low solubilities of brucite and hydrotalcite-like phases formed in the MgO-bearing binders, and was also the reason for the improved performance in stabilising contaminants. The addition of IOC slightly decreased the strength and the permeability of the S/S materials but inconsistent effect on the contaminant immobilisation was found depending on the binder composition. This study showed no degradation of the S/S materials after 3 y exposure to field conditions and has proved the applicability and the advantages of MgO-bearing binders over PC in S/S.

  19. Practitioner Review: The effects of atypical antipsychotics and mood stabilisers in the treatment of depressive symptoms in paediatric bipolar disorder.

    Science.gov (United States)

    Atkin, Tobias; Nuñez, Nicolas; Gobbi, Gabriella

    2017-08-01

    The management of depressive and mixed symptoms in children and adolescents with bipolar disorder (BD) remains a matter of debate. The goal of this review is, thus, to systematically examine the impact of atypical antipsychotics (AAPs) and mood stabilisers in the treatment of bipolar depression and/or mixed states. A literature search was conducted for studies assessing the efficacy of pharmacological treatments for bipolar disorder type I, type II and not otherwise specified with a recent depressive, mixed or manic episode (with depressive symptoms) following DSM-IV criteria in children and adolescents as either acute or maintenance treatment. The databases searched were PubMed/Medline, Google Scholar and Tripdatabase, as well as ClinicalTrials.gov. The search was limited to clinical trials, systematic reviews, meta-analyses and open-label trials published in the English language between the years 2000 and 2015. Sixty clinical studies were found assessing the efficacy of mood stabilisers and AAPs in paediatric BD. Fifteen studies were not included in the primary analysis because they did not assess depressive symptomology/include scores on rating scales of depressive symptoms (Online Supplementary Material). There is sufficient evidence for a Grade A recommendation of the use of olanzapine plus fluoxetine at reducing depressive symptoms in bipolar depression and of quetiapine at high doses for depressive symptoms occurring during mixed episodes. Importantly, even though monotherapy with aripiprazole, risperidone, valproate and lithium was effective at controlling mania, these drugs were not effective at reducing depressive symptoms (level A evidence for nonrecommendation). These results mostly overlap with the approved treatments for bipolar depression in adults. © 2017 Association for Child and Adolescent Mental Health.

  20. Optimal Operation and Stabilising Control of the Concentric Heat-Integrated Distillation Column

    DEFF Research Database (Denmark)

    Bisgaard, Thomas; Skogestad, Sigurd; Huusom, Jakob Kjøbsted

    2016-01-01

    A systematic control structure design method is applied on the concentric heat integrated distillation column (HIDiC) separating benzene and toluene. A degrees of freedom analysis is provided for identifying potential manipulated and controlled variables. Optimal operation is mapped and active...... structure is finally evaluated by dynamic simulation for proving an acceptable performance. (C) 2016, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights...

  1. Red queen dynamics in specific predator-prey systems.

    Science.gov (United States)

    Harris, Terence; Cai, Anna Q

    2015-10-01

    The dynamics of a predator-prey system are studied, with a comparison of discrete and continuous strategy spaces. For a [Formula: see text] system, the average strategies used in the discrete and continuous case are shown to be the same. It is further shown that the inclusion of constant prey switching in the discrete case can have a stabilising effect and reduce the number of available predator types through extinction.

  2. Optimal stabilisation of platforms suspended by ropes using the frequency converter control method

    Directory of Open Access Journals (Sweden)

    Stefan CHWASTEK

    2011-01-01

    Full Text Available The ability to relocate the load from point A to B in the working space and within the specified time cannot be treated as an exhaustive definition of functional quality of modern cranes. Further requirements include the minimization of dynamic loading during the start-up and backing phase and vibration reduction through the control of drives. Besides, when 3D loads are to be handled, their position has to be stabilized. The objective function in this case becomes the minimal time of operation. This study provides a synthesis of an automatic control system for positioning and stabilization of the platform whilst in service.

  3. Geochemical and mineralogical characteristics of percolates and its evaporates from Technosols before and after limestone filler stabilisation.

    Science.gov (United States)

    Pérez-Sirvent, Carmen; Martinez-Sanchez, Maria Jose; Garcia-Lorenzo, Maria Luz; Hernandez-Cordoba, Manuel

    2017-04-01

    The chemistry of waters is recognized as a relevant monitoring tool when assessing the adverse effects of acid mine drainage. The weathering of sulphide minerals produces a great variety of efflorescences of soluble sulphate salts. These minerals play an important role for environmental pollution, since they can be either a sink or a source for acidity and trace elements. This communication deals with the leachability of potentially toxic elements (PTE) eluting from technosols formed from soils affected by mining activities and limestone filler. A total of three contaminated soils affected by opencast mining were selected and mixed with limestone filler at three percentages: 10 %, 20 % and 30 %, providing nine stabilised samples. These samples were stored in containers and moistened simulating rainfall. The percolates obtained were collected, and the PTEs content (As, Cd, Cu, Fe, Pb and Zn) was determined. Evaporation-precipitation experiments were carried out in these waters, and the mineralogical composition of efflorescences was evaluated. The study area is heavily polluted as a result of historical mining and processing activities, producing large amount of wastes, characterised by high trace elements content and acidic pH. The results obtained for the percolates after the rain episode showed that, before the stabilization approach, waters had an acidic pH, high electrical conductivity and high PTEs content. When these soils were mixed with 10, 20 and 30 % of limestone filler, the pH was neutral and the soluble trace element content strongly decreased, being under the detection limit when limestone percentage was 20 % and 30 %. The mineralogical composition of efflorescences before the stabilisation approach showed that predominant minerals were copiapite, followed by gypsum and bilinite. Other soluble sulphates were determined in lower percentage, such as hexahydrite, halotriquite or pickeringite. After the mixing with 10 % of limestone filler, the evaporates

  4. Design and stabilisation of a high area iron molybdate surface for the selective oxidation of methanol to formaldehyde.

    Science.gov (United States)

    Chapman, Stephanie; Brookes, Catherine; Bowker, Michael; Gibson, Emma K; Wells, Peter P

    2016-07-04

    The performance of Mo-enriched, bulk ferric molybdate, employed commercially for the industrially important reaction of the selective oxidation of methanol to formaldehyde, is limited by a low surface area, typically 5-8 m(2) g(-1). Recent advances in the understanding of the iron molybdate catalyst have focused on the study of MoOx@Fe2O3 (MoOx shell, Fe2O3 core) systems, where only a few overlayers of Mo are present on the surface. This method of preparing MoOx@Fe2O3 catalysts was shown to support an iron molybdate surface of higher surface area than the industrially-favoured bulk phase. In this research, a MoOx@Fe2O3 catalyst of even higher surface area was stabilised by modifying a haematite support containing 5 wt% Al dopant. The addition of Al was an important factor for stabilising the haematite surface area and resulted in an iron molybdate surface area of ∼35 m(2) g(-1), around a 5 fold increase on the bulk catalyst. XPS confirmed Mo surface-enrichment, whilst Mo XANES resolved an amorphous MoOx surface monolayer supported on a sublayer of Fe2(MoO4)3 that became increasingly extensive with initial Mo surface loading. The high surface area MoOx@Fe2O3 catalyst proved amenable to bulk characterisation techniques; contributions from Fe2(MoO4)3 were detectable by Raman, XAFS, ATR-IR and XRD spectroscopies. The temperature-programmed pulsed flow reaction of methanol showed that this novel, high surface area catalyst (3ML-HSA) outperformed the undoped analogue (3ML-ISA), and a peak yield of 94% formaldehyde was obtained at ∼40 °C below that for the bulk Fe2(MoO4)3 phase. This work demonstrates how core-shell, multi-component oxides offer new routes for improving catalytic performance and understanding catalytic activity.

  5. Treatment of thoracolumbar fractures with vertebral body bone graft through pedicle and transpedicular fixation via fractured vertebra%伤椎置钉并椎体内植骨内固定术在胸腰椎骨折治疗中的应用

    Institute of Scientific and Technical Information of China (English)

    秦入结; 宋波; 李垠; 盛路新; 刘建; 孙晓

    2012-01-01

    目的 观察伤椎置钉并椎体内植骨内固定术在胸腰椎骨折治疗中的应用效果.方法 至少一侧椎弓根完整的胸腰椎骨折26例,予伤椎撬拨复位置钉、椎体内植骨、椎弓根内固定,据胸腰段正侧位片比较术前、术后即刻、术后6个月的椎体高度及Cobb's角,并评估脊髓神经功能和融合情况.结果 术后随访7~28个月.患者术后即刻伤椎椎体前缘高度占正常高度百分比及Cobb's角优于术前(P均<0.05);伤椎外形恢复满意;按ASIA脊髓神经功能分级,伴神经损伤者15例中,A级1例无恢复,余均改善1~3级(P均<0.05),内固定无失效,植骨皆融合.结论 伤椎置钉并椎体内植骨内固定术治疗胸腰椎骨折可重建椎体结构,增强脊柱稳定,近期疗效较好.%Objective To observe the outcome of vertebral body bone grafting throughpedicle combined with transpedicular fixation via fractured vertebra in the treatment of thoracolumbar fractures, and explore the operation methods. Methods 26 cases of thoracolumbar fractures, which had at least one side pedicle complete , were treated with posterior pedicle fixation by leverage, bone graft through pedicle and transpedicular fixation via fractured vertebra. According to the data of thoracolumbar radiograph, the anterior vertebral height and Cobb's angle of preoperation, postoperation instantly and after 6 monthswere compared. Their fusion results and neurological functions were observed. Results The follow-up period was 7 to 28 months . There were significant differences in the percentage of anterior vertebral height to the normal and Gobb's angle between preoperation and postoperation instantly (all P <0. 05). The shape of injured vertebra were restored satisfactorily . The spinal cord function was classified by ASIA's scale, it was improved 1 to 3 degree in all cases( 15 cases) of pre-operative neurological injury except of one case of grade A (all P < 0. 05). There was no case of fixation

  6. THE EVOLUTION OF THE MACROECONOMIC STABILISATION PENTAGON IN ROMANIA, CZECH REPUBLIC AND HUNGARY

    Directory of Open Access Journals (Sweden)

    Ionita Rodica Oana

    2015-07-01

    Full Text Available This paper aims to achieve the pentagon analysis of macroeconomic stabilization in Romania, Czech Republic and Hungary in the period 2000 to 2013. It is a comparative analysis of the countries above mentioned in terms of the five key targets of economic policy, aiming the increasing, dynamic balance of each economy: economic growth rate, unemployment rate, inflation rate, the budget deficit as a percentage of Gross Domestic Product, the current account deficit of the balance of payments as a percentage of Gross Domestic Product. The main objective of each economy which passes from planned to market economy should be to cease the economic decline, followed by the elimination of internal and external imbalances and only after that it should be followed by a continuous growth process. All the above mentioned indicators shall be represented on an ad hoc graduated scale. The period of research was chosen so as to obtain a view of the macroeconomic policies in transition from one period to another, in order to highlight the common as well as the main differences in the approach used for economy stabilization. Therefore I have computed the graphical analysis of macroeconomic stabilization pentagon for the three countries in the period 2000- 2013 to captures the dynamics of the economic policy mix. This benchmark tool shows the interdependence which exists between inflation and other important economic indicators. The events occurred in the period starting with 2007/2008 have raised the interest of economics researchers, highlighting the need for significant improvements in the surveillance of the economic and financial system. The global fragility generated concerns regarding the vulnerabilities and causes which led to the occurrence of such events, thus generating different measurement techniques. Despite all its advantages, this approach has a significant limitation consisting in the fact that it can only reveal a picture without surprising other

  7. Méthodes numériques pour le contrôle et la stabilisation rapide de grandes structures flexibles

    OpenAIRE

    Briffaut, Jean-Séverin

    1999-01-01

    L'objectif de cette thèse est d'étudier numériquement la contrôlabilité exacte et la stabilisation rapide de multistructures flexibles composées de poutres d'Euler-Navier-Bernoulli. On utilise la méthode HUM de J.-L. Lions (resp. une variante proposée par V. Komornik) qui s'exprime directement au niveau continu et qui fournit un algorithme constructif de lois de contrôle frontière en boucle ouverte (resp. fermée) permettant de contrôler exactement (resp. de stabiliser de façon arbitrairement ...

  8. Diode-pumped Q-switched Nd{sup 3+} : YAG laser operating in a wide temperature range without thermal stabilisation of pump diodes

    Energy Technology Data Exchange (ETDEWEB)

    Vainshenker, A E; Vilenskiy, A V; Kazakov, A A; Lysoy, B G; Mikhailov, L K; Pashkov, V A [Open Joint-Stock Company ' M.F. Stel' makh Polyus Research and Development Institute' , Moscow (Russian Federation)

    2013-02-28

    A model sample of a compact low-power-consumption Nd{sup 3+} : YAG laser emitting 20-mJ pulses with a pulse repetition rate up to 20 Hz (in cyclic duty) at a wavelength of 1064 nm is developed and studied. The laser is designed for operating at external temperatures from -40 to +50 deg C. This was achieved by using quasi-end diode pumping without thermal stabilisation of pump diodes. (laser optics 2012)

  9. p-Phosphonic acid calix[8]arene assisted dispersion and stabilisation of pea-pod C60@multi-walled carbon nanotubes in water.

    Science.gov (United States)

    Chen, Xianjue; Gibson, Christopher T; Britton, Joshua; Eggers, Paul K; Wahid, M Haniff; Raston, Colin L

    2015-02-11

    A facile approach has been developed for non-covalently stabilising pristine C60 and multi-walled carbon nanotubes (MWCNTs) in water in the presence of p-phosphonic acid calix[8]arene, along with the formation of a 'pea-pod' encapsulation of the fullerene inside the MWCNTs. Aqueous dispersions of the different carbon nano-materials are readily decorated with palladium nanoparticles.

  10. Friction behaviour of solid oxide lubricants as second phase in alpha-Al2O3 and stabilised ZrO2 composites

    NARCIS (Netherlands)

    Kerkwijk, B.; de la Luz Garcia-Curiel, M.M.; van Zyl, W.E.; Winnubst, Aloysius J.A.; Mulder, E.J.; Schipper, Dirk J.; Verweij, H.

    2004-01-01

    The influence of metal oxide additives within alumina (¿-Al2O3) and yttria-stabilised tetragonal zirconia (Y-TZP) matrices was studied with respect to the tribological behaviour of the composites. The solid lubricants CuO, ZnO, MgO, MnO2 and B2O3 were added in sufficiently small quantities (1 or 5

  11. Clinical effect observation of transpedicular vertebral osteotomy spine shortening in treating spinal kyphosis complicated with spinal cord nerve dysfunction%经椎弓根椎体截骨术治疗脊柱后凸畸形的临床疗效观察

    Institute of Scientific and Technical Information of China (English)

    余贵华; 陈军; 向福胜; 王冶; 石卫星

    2015-01-01

    Objective To study the clinical effect of transpedicular vertebral osteotomy spine shortening in treating spinal kyphosis com-plicated with spinal cord nerve dysfunction. Methods A total of 80 patients with spinal kyphosis complicated with spinal cord nerve dys-function in our hospital from May 2013 to June 2014 were enrolled and randomly divided into observation group(n=40) and control group (n=40). The observation group received transpedicular vertebral osteotomy,and the control group received lamina and facet osteotomy. The situation of surgery,vertebral healing and spinal cord function condition,treatment effect between two groups were compared. Results The operation time and postoperative ambulation time of observation group were shorter than those of control group [(76. 52 ± 9. 1) vs (113. 46 ± 13. 44) min,(3. 28 ± 0. 43) vs (5. 67 ± 0. 68) d]. The postoperative bleeding volume,postoperative drainage volume of observation group were less than those of control group [(36. 14 ± 4. 28) vs (55. 23 ± 7. 15) mL,(17. 92 ± 2. 12) vs (29. 64 ± 4. 28) mL]. The Cobb angle and residual urine volume,initial and strong urinary bladder capacity,maximum urinary output of observation group were significantly less than those of control group [(6. 12 ± 0. 68) vs(9. 78 ± 1. 21) mL,(241. 45 ± 28. 56) vs(335. 54 ± 36. 86) mL,(456. 56 ± 51. 78) vs (586. 35 ± 63. 12) mL,(63. 78 ± 7. 24) vs (96. 32 ± 10. 22) mL]. The intervertebral height of observation group was higher than that of control group [(12. 62 ± 2. 81) vs (8. 41 ± 1. 32) mm]. The excellent rate of observation group was significantly higher than that of control group(97. 50%vs 82. 50%). Conclusion Transpedicular vertebral osteotomy spine shortening is helpful to reduce operation wound, pro-mote postoperative recovery,correct kyphotic deformity and improve neurological functionin,improve therapeutic effect.%目的:探讨经椎弓根椎体截骨脊柱缩短术治疗并发脊髓神经功能障碍的脊柱

  12. 跳跃式经椎弓根椎体截骨术矫治强直性脊柱炎重度后凸畸形的疗效%Clinical efficacies of skipping two-level transpedicular wedge osteotomy for correction of severe kyphosis in ankylosing spondylitis

    Institute of Scientific and Technical Information of China (English)

    宋若先; 张永刚; 张雪松; 毛克亚; 郑国权; 王岩

    2012-01-01

    目的 探讨跳跃式经椎弓根双脊椎截骨术矫治强直性脊柱炎重度后凸畸形的临床效果.方法 2003年1月至2009年12月对解放军总医院骨科收治的38例颌眉角或脊柱整体后凸角>70°的强直性脊柱炎重度后凸畸形患者,行后路跳跃式经椎弓根双脊椎截骨矫形内固定术.术前测量脊柱整体后凸角、胸腰段后凸角、腰椎前凸角及颌眉角与躯干矢状位失平衡距离,根据后凸畸形的特点,参考正常脊柱生理曲度与力线特点,分配截骨部位与角度,并在计算机上模拟截骨确认.观察术后各指标改善情况,并评价治疗满意度.结果 手术时间平均309 min,出血量平均2050 ml.脊柱整体后凸角、胸腰段后凸角、腰椎前凸角分别由术前(101.0±21.3)°、(45.2±13.6)°、(-28.2±23.3)°改善至术后(26.0±12.1)°、(2.8±11.6)°、(28.9±13.3)°;颌眉角由术前(79.4±15.9)°矫正到术后(13.6±10.9)°;矢状面失平衡距离由术前(49±13)cm,矫正到术后的(15±7)cm,差异均有统计学意义(均P<0.01).术后患者均能平视、直立行走及仰卧睡眠.平均随访32个月(24 ~78个月),截骨部位愈合良好,全部病例无矫正度丢失及内置物失败,SRS-22评分由术前平均1.8分改善到术后4.2分,疗效满意.结论 跳跃式经椎弓根双脊椎截骨矫形内固定术可有效矫正强直性脊柱炎重度后凸畸形,临床效果满意.%Objective To explore the clinical efficacies of skipping two-level transpedicular wedge osteotomy in the correction of severe kyphotic deformity in ankylosing spondylitis (AS).Methods From January 2003 to December 2009,a total of 38 consecutive patients with AS and severe kyphosis ( chin-brow vertical angle (CBVA) or global thoraco-lumbar kyphosis angle (TLKA) over 70°) undergoing skipping two-level transpedicular wedge osteotomy at the Department of Orthopedics of Chinese PLA General Hospital were reviewed retrospectively.There were 32 males and 6

  13. 肌间隙入路、椎弓根椎体内植骨结合骨折椎螺钉治疗胸腰椎骨折%The treatment of chest lumbar vertebra bone fracture by muscle gap approach with vertebral transpedicular grafting the bone union bone vertebral fractures screws

    Institute of Scientific and Technical Information of China (English)

    王桥贵

    2016-01-01

    目的:探讨胸腰段脊柱肌间隙后入路(muscle gap approach,MGA)经椎弓根植骨(transpedicular grafting,TPG)和结合骨折椎螺钉(vertebral fractures screws,VFS )治疗胸腰段脊柱骨折的方法和疗效。方法对30例胸腰椎骨折患者经MGA, TPG,VFS,后路短节段椎弓根内固定手术,记录手术时间、失血量、住院时间。在术前,术后及末次随访时测量伤椎前缘高度与正常高度的比值、后凸Cobb角,末次随访的过伸过屈位X线片上测量手术节段运动范围,了解神经功能改变及腰背疼痛变化,功能评定采用Greenough腰痛评分。结果随访15-38个月(平均22.3个月),平均手术时间:130min,平均失血量362ml,平均住院时间15d。术前平均Cobb角360,椎体平均相对高度降低48.8%,术后平均Cobb角2.30,术后椎体相对高度降低≤6.2%。末次随访平均Cobb角矫正丢失2.50,椎体相对高度矫正丢失2.3%。无断钉及内固定物松动,无供骨区并发症。结论肌间隙入路椎弓根椎体内植骨结合骨折椎螺钉治疗胸腰椎骨折,疗效满意。具有失血量少,保留手术节段运动范围,无供骨区并发症。最大可能保留后柱完整性,增强胸腰椎骨折后路短节段内固定的牢固性,利于矫正后凸畸形和维持矫正效果。%Objective This discussion aims at the methods and treatment of the chest waist section spinal column bone fracture through chest waist section spinal column muscle gap approach with the bone transpedicular grafting(TPG)and the union bone vertebral fractures screws(VFS).Methods 30 cases were conducted an operation on the chest waist section spinal column bone fracture by MGA, TPG,VFS and the fixed surgery in the rear guard short stage vertebral arch root. The surgery time,the amount of blood loss,the time of treatment in hospital were recorded. It should be learned that the ratio of the injury front height and

  14. 后路经椎弓根环形减压三柱重建治疗胸腰椎骨折%Circular decompression and three column reconstruction of spine in the treatment of thoracolumbar vertebral fracture through a posterior transpedicular approach

    Institute of Scientific and Technical Information of China (English)

    任亮; 孙先泽; 于金河; 赵正琦; 刘艳兵

    2012-01-01

    O b jective To evaluate tie effect of circular decanpiession and three-column reconstruction of spine in the treatnentof fhoracolznbar vertebral fracture through a posterior transpedicular approach M ethods Twenty patients with thoracolumbar vertebral fractures were treated with broken-bone excision, circular decompression and three- column reconstruction of spine through a posterior transpedicular approach Twenty patients were followed up Neurological status was evaluated by ASIA, scoring systan X ray and CT results were exanined pre-operatively, atl week postoperatively and atl2 month postoperatively, which was used to compare the canal occupation and the Cobb angle, and to evaluate the decompression and reconstruction status Results All operations were finished successfully The average operation tine was2. 8 h, and the average hanorrhage was900ml There was no nerve and blood vessel injury and no infection and deep vein thrombosis All patients were perfomed recovery training atl week postoperatively The average follow-up was 18 months( ranging 12-24 months). Bone graft fusion was observed in all patients except one No looseness and rupture of internal fixation, no obvious bss of vertebral heigh| spinal radian and vertebral canal volume were observed Nervous function resulted in different degree of recovery in all patients except those who had the nervous function of grade A Conclusion The treatnentof thoraco-lumbar vertebral fractures by broken-bone excision, circular decompression and three-column reconstruction of spine through a posterior transpedicular approach is safe and useful in reconstructing vertebral heighf spinal canal volume and Cobb-angle This operation has the advantages of little trauma and quick recovery%目的 探讨后路经椎弓根环形减压三柱重建治疗胸腰段椎体骨折临床疗效.方法 对20例胸腰段椎体骨折采用后路经椎弓根椎管前方骨块切除、环形减压、三柱重建技术进行手术治疗,采用美

  15. The transpedicular corpectomy through simple posterior approach combined with internal fixation and prosthetic vertebral replacement for thoracic and lumbar spine metastatic tumor%单纯后路经椎弓根椎体次全切除内固定联合人工椎体置换治疗胸腰椎转移瘤

    Institute of Scientific and Technical Information of China (English)

    燕太强; 郭卫; 杨荣利; 董森; 李晓

    2011-01-01

    Objective To evaluate the clinical outcome of the transpedicular corpectomy through simple posterior approach combined with intemal fixation and prosthetic vertebral replacement for thoracic and lumbar spine metastatic tumor.Methods From January 2007 to March 2010, 21 patients with thoracic and lumbar spine metastatic tumors (9 males, 12 females; 16 in thoracic spine, 5 in lumbar spine) underwent the transpedicular corpectomy through simple posterior approach combined with internal fixation and prosthetic vertebral replacement.The mean age was 58 years (range, 39-77 years).The average pre-operative VAS score was 7.4 (range, 5-10).According to the pre-operative Frankel grades for spinal cord, 3 cases obtained grade C, 6 grade D and 12 grade E.Pre-operative ECOG grades showed 1 case with grade 2, 18 with grade 3 and 2 with grade 4.Results The mean operative time was 3.5 hours (range, 2-5 hours), with no intra-operative death.The mean intra-operative blood loss was 2150 ml (range, 800-5000ml).1 patient died of multiple organ failure two weeks postoperatively.A11 patients with pain reported lower VAS scores postoperatively (with average being 3.1; range, 1-4.5).Of the Frankel grades, 1 patient with grade C reported no change after surgery, while 1 patient with grade C was improved to grade D and 6 patients with grade D to grade E.3 cases (14.3%)were re-operated half year to 1 year after surgery due to recurrence.In the last follow-up, 20 patients had already been followed up for an average of 13 months (range, 3-24months).Among them, 13 cases died of the primary disease with an average survival of 10 months.The remaining surviving patients reported ECOG grades from grade 1 to grade 3.Conclusions The transpedicular corpectomy through simple posterior approach combined with internal fixation and prosthetic vertebral replacement for thoracic and lumbar spine metastatic tumor can provide plentiful decompression and achieve favorable surgical results.It can effectively

  16. Phase II study of SPI-77 (sterically stabilised liposomal cisplatin) in advanced non-small-cell lung cancer.

    Science.gov (United States)

    White, S C; Lorigan, P; Margison, G P; Margison, J M; Martin, F; Thatcher, N; Anderson, H; Ranson, M

    2006-10-09

    To determine the efficacy and tolerability of SPI-77 (sterically stabilised liposomal cisplatin) at three dose levels in patients with advanced non-small-cell lung cancer (NSCLC). Patients had Stage IIIB or IV NSCLC and were chemo-naïve, and Eastern Oncology Cooperative Group 0-2. The first cohort received SPI-77 at 100 mg m-2, the second 200 mg m-2 and the final cohort 260 mg m-2. Patients had also pharmacokinetics and analysis of leucocyte platinum (Pt)-DNA adducts performed. Twenty-six patients were treated, with 22 patients being evaluable for response. Only one response occurred at the 200 mg m-2 dose level for an overall response rate of 4.5% (7.1% at >or=200 mg m-2). No significant toxicity was noted including nephrotoxicity or ototoxicity aside from two patients with Grade 3 nausea. No routine antiemetics or hydration was used. The pharmacokinetic profile of SPI-77 was typical for a liposomally formulated drug, and the AUC appeared to be proportional to the dose of SPI-77. Plasma Pt levels and leucocyte DNA adduct levels did not appear to rise with successive doses. SPI-77 demonstrates only modest activity in patients with NSCLC.

  17. Application of X-ray microtomography for the characterisation of hollow polymer-stabilised spray dried amorphous dispersion particles.

    Science.gov (United States)

    Gamble, John F; Terada, Masako; Holzner, Christian; Lavery, Leah; Nicholson, Sarah J; Timmins, Peter; Tobyn, Mike

    2016-08-20

    The aim of this study was to investigate the capability of X-ray microtomography to obtain information relating to powder characteristics such as wall thickness and solid volume fraction for hollow, polymer-stabilised spray dried dispersion (SDD) particles. SDDs of varying particle properties, with respect to shell wall thickness and degree of particle collapse, were utilised to assess the capability of the approach. The results demonstrate that the approach can provide insight into the morphological characteristics of these hollow particles, and thereby a means to understand/predict the processability and performance characteristics of the bulk material. Quantitative assessments of particle wall thickness, particle/void volume and thereby solid volume fraction were also demonstrated to be achievable. The analysis was also shown to be able to qualitatively assess the impact of the drying rate on the morphological nature of the particle surfaces, thus providing further insight into the final particle shape. The approach demonstrated a practical means to access potentially important particle characteristics for SDD materials which, in addition to the standard bulk powder measurements such as particle size and bulk density, may enable a better understanding of such materials, and their impact on downstream processability and dosage form performance.

  18. Reduced glutathione and procaine hydrochloride protect the nucleoprotein structure of boar spermatozoa during freeze-thawing by stabilising disulfide bonds.

    Science.gov (United States)

    Yeste, Marc; Flores, Eva; Estrada, Efrén; Bonet, Sergi; Rigau, Teresa; Rodríguez-Gil, Joan E

    2013-01-01

    One important change the head of boar spermatozoa during freeze-thawing is the destabilisation of its nucleoprotein structure due to a disruption of disulfide bonds. With the aim of better understanding these changes in frozen-thawed spermatozoa, two agents, namely reduced glutathione (GSH) and procaine hydrochloride (ProHCl), were added at different concentrations to the freezing media at different concentrations and combinations over the range 1-2mM. Then, 30 and 240 min after thawing, cysteine-free residue levels of boar sperm nucleoproteins, DNA fragmentation and other sperm functional parameters were evaluated. Both GSH and ProHCl, at final concentrations of 2mM, induced a significant (Psperm head disulfide bonds 30 and 240 min after thawing compared with the frozen-thawed control. This effect was accompanied by a significant (Psperm peroxide levels, motility patterns and plasma membrane integrity. In conclusion, the results show that both GSH and ProHCl have a stabilising effect on the nucleoprotein structure of frozen-thawed spermatozoa, although only GSH exerts an appreciable effect on sperm viability.

  19. Posturographic stabilisation of healthy subjects exposed to full-length mirror image is inversely related to body-image preoccupations.

    Science.gov (United States)

    Galeazzi, Gian Maria; Monzani, Daniele; Gherpelli, Chiara; Covezzi, Roberta; Guaraldi, Gian Paolo

    2006-12-13

    Affective states, anxiety in particular, have been shown to negatively influence human postural control efficiency as measured by posturographic means, while exposure to a full-length mirror image of one's body exerts a stabilizing effect. We tested the hypothesis that body image concerns and preoccupations would relate negatively to this stabilising effect. Sixty-six healthy students, who screened negative for psychiatric disorders, completed rating scales for anxiety, depression and body image concerns. Posturography recordings of body sway were taken under three conditions: with eyes closed, looking at a vertical bar and looking at a full-length mirror. The Eyes Open/Mirror Stabilometric Quotient [EOMQ=(sway path with eyes closed/sway path looking at the mirror)x100], an index of how much postural control is stabilized by mirror feedback in comparison to the visual vertical bar condition, was significantly inversely related to body image concerns and preoccupations, and to trait anxiety. This finding confirms the impact of emotional factors on human postural control, which warrant further studies. If confirmed in clinical populations characterized by high levels of body image disturbances, e.g. eating disorders, it could lead to developments in the assessment and monitoring of these patients.

  20. Structural evidence for solvent-stabilisation by aspartic acid as a mechanism for halophilic protein stability in high salt concentrations.

    Science.gov (United States)

    Lenton, Samuel; Walsh, Danielle L; Rhys, Natasha H; Soper, Alan K; Dougan, Lorna

    2016-07-21

    Halophilic organisms have adapted to survive in high salt environments, where mesophilic organisms would perish. One of the biggest challenges faced by halophilic proteins is the ability to maintain both the structure and function at molar concentrations of salt. A distinct adaptation of halophilic proteins, compared to mesophilic homologues, is the abundance of aspartic acid on the protein surface. Mutagenesis and crystallographic studies of halophilic proteins suggest an important role for solvent interactions with the surface aspartic acid residues. This interaction, between the regions of the acidic protein surface and the solvent, is thought to maintain a hydration layer around the protein at molar salt concentrations thereby allowing halophilic proteins to retain their functional state. Here we present neutron diffraction data of the monomeric zwitterionic form of aspartic acid solutions at physiological pH in 0.25 M and 2.5 M concentration of potassium chloride, to mimic mesophilic and halophilic-like environmental conditions. We have used isotopic substitution in combination with empirical potential structure refinement to extract atomic-scale information from the data. Our study provides structural insights that support the hypothesis that carboxyl groups on acidic residues bind water more tightly under high salt conditions, in support of the residue-ion interaction model of halophilic protein stabilisation. Furthermore our data show that in the presence of high salt the self-association between the zwitterionic form of aspartic acid molecules is reduced, suggesting a possible mechanism through which protein aggregation is prevented.

  1. Chemical Stabilisation of Sand Part IX: Orthophthalate type Unsaturated Polyester Resin for Inducing Fast setting Behaviour and High Strength

    Directory of Open Access Journals (Sweden)

    B. P. Gupta

    1994-01-01

    Full Text Available Polymer concrete composites have been made from orthophthalate-type unsaturated polyester resin, methyl ethyl ketone peroxide as initiator, cobalt naphthenate as accelerator and desert sand as filler. Composites preferred using resin (10-25 per cent, initiator (4 per cent and accelerator (2 per cent with representative desert sand samples of different particle sizes (0.2-0.02 mm, 2-0.2 mm and 4-2 mm as filler recorded unconfined compression strength ranging from 4 to 442 kg/cm/sup 2/ after curing at 50 degree centigrade in an oven for 0.5-24 h. Using coarse and fine sand samples with 10 and 15 per cent resin systems the maximum strength of 391 and 326 kg/cm/sup 2/ respectively was attained after 2 h of curing at 50 degree centigrade. The fast setting resin system with strength in this range is quite adequate for the construction of chemically stabilised surfaces, which withstand trafficability of vehicles, operation of helicopters and aircraft's requiring a maximum strength up to 275 kg/cm/sup 2/. These composites may prove useful for rapid repair of roads, helipads and runways damaged during operational activities. A mathematical model has been developed for predicting resin percentage needed for obtaining composite material of requisite strength. The observed and model predicted values have been found to show close agreement.

  2. Who's afraid of atmospheric stabilisation? Making the link between energy resources and climate change

    Energy Technology Data Exchange (ETDEWEB)

    Grubb, M. [Imperial College, London (United Kingdom). J.H. Huxley School of Environmental and Earth Science, Royal School of Mines

    2001-09-01

    The distribution of fossil fuel reserves and resources between different regions and deposits has strong implications for climate change economics and policy. The task of stabilising the atmosphere is intimately linked to the question of long-term energy supplies as conventional petroleum reserves deplete, notwithstanding debates about the scope for expanding reserves through continued exploration and development. It suggests a supply-side component to complement the consumption orientation of existing climate policies: the task is to ensure that investment and innovation moves towards the 'low carbon frontier' instead of the 'high carbon frontier'. This also implies that the OPEC countries have little to fear about the long-run impact of climate change policy. The priority is to deter development of more carbon-intensive unconventional petroleum deposits and technologies, and to ensure that the existing trends to diversify power generation sources continue and extend more widely over time. Although supply-side constraints will not solve the climate problem they make the task a lot easier, if the opportunities are taken. 14 refs., 3 figs.

  3. A group-based approach to stabilisation and symptom management in a phased treatment model for refugees and asylum seekers

    Directory of Open Access Journals (Sweden)

    Mary E. A. Robertson

    2013-12-01

    Full Text Available Background: Traumatised asylum seekers and refugees may present with significant and complex mental health problems as a result of prolonged, extreme, and multiple traumatic events. This is further complicated by ongoing complex social circumstances. Concepts: In our work at the Traumatic Stress Clinic (TSC, the understanding afforded by the concept of complex posttraumatic stress disorder (PTSD together with the related notion of a phased treatment model, provides a useful framework for organising our work with this population. Clinical Applications: An explication of complex PTSD as it applies to our client group is presented, followed by a description of our phased treatment model and an outline of the core principles, which guide our clinical approach. Our symptom management and stabilisation groups have been developed and refined over time and draw on techniques from a variety of cognitive behavioural therapies. These are described in some detail with illustrative clinical case vignettes. Conclusion: This paper concludes with some reflections on the challenges inherent to working with this complex client group.

  4. The adsorption of human serum albumin (HSA) on CO2 laser modified magnesia partially stabilised zirconia (MgO-PSZ).

    Science.gov (United States)

    Hao, L; Lawrence, J

    2004-03-15

    Magnesia partially stabilised zirconia (MgO-PSZ), a bioinert ceramic, exhibits high mechanical strength, excellent corrosion resistance and good biocompatibility, but it does not naturally form a direct bond with bone resulting in a lack of osteointegration. The surface properties and structure of a biomaterial play an essential role in protein adsorption. As such, changes in the surface properties and structure of biomaterials may in turn alter their bioactivity. So, the fundamental reactions at the interface of biomaterials and tissue should influence their integration and bone-bonding properties. To this end, CO2 laser radiation was used to modify the surface roughness, crystal size, phase and surface energy of the MgO-PSZ. The basic mechanisms active in improving the surface energy were analysed and found to be the phase change and augmented surface area. The adsorption of human serum albumin (HSA), which is a non-cell adhesive protein, was compared on the untreated and CO2 laser modified MgO-PSZ. It was observed that the thickness of the adsorbed HSA decreased as the polar surface energy of the MgO-PSZ increased, indicating that HSA adsorbed more effectively on the hydrophobic MgO-PSZ surface than the hydrophilic surface. The current study provided important information regarding protein-biomaterial interactions and possible mechanisms behind the cell interaction and in vivo behaviour.

  5. Evaluation of a lime-mediated sewage sludge stabilisation process. Product characterisation and technological validation for its use in the cement industry.

    Science.gov (United States)

    Rodríguez, N Husillos; Granados, R J; Blanco-Varela, M T; Cortina, J L; Martínez-Ramírez, S; Marsal, M; Guillem, M; Puig, J; Fos, C; Larrotcha, E; Flores, J

    2012-03-01

    This paper describes an industrial process for stabilising sewage sludge (SS) with lime and evaluates the viability of the stabilised product, denominated Neutral, as a raw material for the cement industry. Lime not only stabilised the sludge, raised the temperature of the mix to 80-100°C, furthering water evaporation, portlandite formation and the partial oxidation of the organic matter present in the sludge. Process mass and energy balances were determined. Neutral, a white powder consisting of portlandite (49.8%), calcite (16.6%), inorganic oxides (13.4%) and organic matter and moisture (20.2%), proved to be technologically apt for inclusion as a component in cement raw mixes. In this study, it was used instead of limestone in raw mixes clinkerised at 1400, 1450 and 1500°C. These raw meals exhibited greater reactivity at high temperatures than the limestone product and their calcination at 1500°C yielded clinker containing over 75% calcium silicates, the key phases in Portland clinker. Finally, the two types of raw meal (Neutral and limestone) were observed to exhibit similar mineralogy and crystal size and distribution.

  6. α{sup '} inflation. Moduli stabilisation and observable tensors from higher derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Cicoli, Michele [Bologna Univ. (Italy). Dipt. di Fisica ed Astronomia; INFN, Sezione di Bologna (Italy); Abdus Salam International Centre for Theoretical Physics, Trieste (Italy); Ciupke, David [DESY, Hamburg (Germany). Theory Group; De Alwis, Senarath [Colorado Univ., Boulder, CO (United States). Dept. of Physics; Muia, Francesco [INFN, Sezione di Bologna (Italy)

    2016-07-15

    The leading order dynamics of the type IIB Large Volume Scenario is characterised by the interplay between α{sup '} and non-perturbative effects which fix the overall volume and all local blow-up modes leaving (in general) several flat directions. In this paper we show that, in an arbitrary Calabi-Yau with at least one blow-up mode resolving a point-like singularity, any remaining flat directions can be lifted at subleading order by the inclusions of higher derivative α{sup '} corrections. We then focus on simple fibred cases with one remaining flat direction which can behave as an inflaton if its potential is generated by both higher derivative α{sup '} and winding loop corrections. Natural values of the underlying parameters give a spectral index in agreement with observational data and a tensor-to-scalar ratio of order r=0.01 which could be observed by forthcoming CMB experiments. Dangerous corrections from higher dimensional operators are suppressed due to the presence of an approximate non-compact shift symmetry.

  7. Development of Tools and Techniques to Survey, Assess, Stabilise, Monitor and Preserve Underwater Archaeological Sites: SASMAP

    Science.gov (United States)

    Gregory, D. J.

    2015-08-01

    SASMAP's purpose is to develop new technologies and best practices in order to locate, assess and manage Europe's underwater cultural heritage in a more effective way than is possible today. SASMAP has taken an holistic- and process- based approach to investigating underwater environments and the archaeological sites contained therein. End user of the results of SASMAP are severalfold; i) to benefiet the SMEs involved in the project and development of their products for the offshore industry (not just for archaeological purposes) ii) a better understanding of the marine environment and its effect on archaeological materials iii) the collation of the results from the project into guidelines that can be used by cultural resource managers to better administer and optimise developer lead underwater archaeological project within Europe in accordance with European legislation (Treaty of Valetta (1992). Summarily the project has utilised a down scaling approach to localise archaeological sites at a large scale regional level. This has involved using innovative satellite imagery to obtain seamless topography maps over coastal areas and the seabed (accurate to a depth of 6m) as well as the development of a 3D sub bottom profiler to look within the seabed. Results obtained from the downscaling approach at the study areas in the project (Greece and Denmark) have enabled geological models to be developed inorder to work towards predictive modelling of where submerged prehistoric sites may be encountered. Once sites have been located an upscaling approach has been taken to assessing an individual site and the materials on and within it in order to better understand the state of preservation and dynamic conditions of a site and how it can best be preserved through in situ preservation or excavation. This has involved the development of equipment to monitor the seabed environment (open water and in sediments), equipment for sampling sediments and assessing the state of

  8. On the nature and origin of garnet in highly-refractory Archean lithosphere: implications for continent stabilisation

    Science.gov (United States)

    Gibson, Sally

    2014-05-01

    The nature and timescales of garnet formation in the Earth's subcontinental lithospheric mantle (SCLM) are important to our understanding of how this rigid outer shell has evolved and stabilised since the Archean. Nevertheless, the widespread occurrence of pyrope garnet in the sub-cratonic mantle remains one of the 'holy grails' of mantle petrology. The paradox is that garnet often occurs in mantle lithologies (dunites and harzburgites) which represent residues of major melting events (up to 40 %) whereas experimental studies on fertile peridotite suggest this phase should be exhausted by <20 % melting. Furthermore, garnets commonly found in mantle peridotite suites have diverse compositions that are typically in equilibrium with high-pressure, small-fraction, mantle melts suggesting they formed as a result of enrichment of the lithospheric mantle following cratonisation. This refertilisation -- which typically involves addition of Fe, incompatible trace elements and volatiles -- affects the lower 30 km of the lithosphere and potentially leads to negative buoyancy and destabilisation. Pyrope garnets found in mantle xenoliths from the eastern margin of the Tanzanian Craton (Lashaine) have diverse compositions and provide major constraints on how the underlying deep (120 to 160 km) mantle stabilised and evolved during the last 3 billion years. The garnets display systematic trends from ultra-depleted to enriched compositions that have not been recognised in peridotite suites from elsewhere (Gibson et al., 2013). Certain harzburgite members of the xenolith suite contain the first reported occurrence of pyrope garnets with rare-earth element (REE) patterns similar to hypothetical garnets proposed by Stachel et al. (2004) to have formed in the Earth's SCLM during the Archean, prior to metasomatism. These rare ultra-depleted low-Cr garnets occur in low temperature (~1050 oC) xenoliths derived from depths of ~120 km and coexist in chemical and textural equilibrium with

  9. Do iron and aluminium oxides stabilise organic matter in soil? A multi-scale statistical analysis, from field to horizon

    Science.gov (United States)

    Moni, C.; Chabbi, A.; Nunan, N.; Rumpel, C.; Chenu, C.

    2007-12-01

    Although many "in vitro" experiments demonstrated that Fe and Al oxides stabilise organic carbon (OC) in soil, very few field studies validated that result, and none of them took into account the influence of scale and that of depth on the relationships linking OC to metal oxides in soil. In the present study, we characterised the latter as a function of depth and horizon at two different sampling scales: the field scale and the pedological pit scale. Twenty seven pits, 2 m deep, were opened over a 22 ha area. At large scale, samples were collected per horizons, whereas at fine scale, 150 positioned samples were collected over the surface of a selected profile. All samples were analysed for their content in OC, in Fe and Al oxides (amorphous Feo, Alo and crystalline Fed-o, Ald-o), and in both forms of Si associated either with amorphous or crystalline forms of metal oxides (Sio, Sid-o). For both sampling scales, relationships between OC and Feo, Alo, Sio, Fed-o, Ald-o, Sid-o were statistically investigated per whole profiles and per horizons. For whole profile at large and fine scale, results showed that all variables were correlated to OC. However, all variables, except Sio at fine scale, were also correlated with depth, suggesting that most of these correlations might only be due to a simultaneous depth dependency of correlated variables. On the contrary, within single horizons much less correlations were observed suggesting that this mode of investigation limits the confounding effects of depth. At fine scale per horizons, seven correlations independent from depth were observed in deep horizons only. Four of them were positive and implied amorphous form of Fe and Al suggesting that these oxides physically interact with OM in the subsoil, whereas the three last were negative and implied both forms of Si, suggesting that Si compete with OC for the fixation on sorption sites. In the three deepest horizons, slope coefficients of linear correlations between OC and

  10. Bronchodilatory and mast cell stabilising activity ofCressa cretica L.:Evaluation throughin vivo andin vitro experimental models

    Institute of Scientific and Technical Information of China (English)

    Priyashree Sunita; S Jha; Shakti Prasad Pattanayak

    2012-01-01

    Objective:To evaluate the effect of ethylacetate fraction (Fr-Et) and methanolic fraction (Fr-Me) obtained fromCressa cretica L.(C. cretica) L. on experimental models for bronchodilatory activity and mast cell stabilising activity.Methods: The effect of Fr-Et and Fr-Me were studied on acetylcholine and histamine aerosol-induced broncospasm using guinea pigs as experimental animals. Also, the effects of these fractions were evaluated on the isolated guinea pig tracheal preparations. Besides this mast cell degranulation effect was assessed using egg albumin and compound48/80 on rat peritoneal mast cells.Results:Significant increase in preconvulsion time was observed due to pretreatment with the fractions when guinea pigs were exposed to histamine and acetylcholine aerosol. Fr-Et and Fr-Me significantly increased the preconvulsion in a dose depended manner that suggestive of bronchodilating activity. Fr-Et and Fr-Me exhibited a significant concentration dependant relaxant effect on guinea pig trachea pre-contracted with CCh,K+ and histamine. The results revealed that Fr-Et to be more potent than Fr-Me in relaxing histamine and K+ and calcium induced contraction than CCh induced contractions. Studies on the fractions in protecting mast cell degranulation, which were elicited by the egg albumin as well as synthetic compound 48/80 revealed both the fractions significantly protect the mast cell degranulation, which release mediators such as histamine and proinflammatory cytokines through various stimuli in a dose depended manner.Conclusions:Thus our study established the bronchodilator activity, and mast cell stabilizing activity which are important mediators that provoke or sustain in asthma.

  11. Stabilising metal(loid)s in soil with iron and aluminium-based products: microbial, biochemical and plant growth impact.

    Science.gov (United States)

    Garau, Giovanni; Silvetti, Margherita; Castaldi, Paola; Mele, Elena; Deiana, Pietrino; Deiana, Salvatore

    2014-06-15

    Four iron and aluminium-based products, including red mud (RM), hematite (Fe2O3), an iron-rich water treatment residual (Fe-WTR) and amorphous Al hydroxide (Al-OH), were evaluated for their effectiveness at stabilising As and heavy metals (i.e. Cd, Cu, Pb, Zn) in a circumneutral contaminated soil [As (2105 mg kg(-1)), Cd (18 mg kg(-1)), Cu (264 mg kg(-1)), Pb (710 mg kg(-1)), Zn (522 mg kg(-1))]. Treatment impacts on soil microbial and biochemical features (i.e. microbial biomass-C, microbial counts, 16S rRNA PCR-TTGE of culturable bacteria, dehydrogenase, urease and β-glucosidase activity, Biolog derived parameters-AWCD and richness) as well as bean (Phaseolus vulgaris) and wheat (Triticum vulgare) growth were also assessed. After 6 months equilibration, all the amendments (application rate 3% w/w) but RM reduced labile As while only Al-OH reduced the concentration of water-soluble heavy metals. Despite the highest bioavailability of contaminants, most of the soil microbial and biochemical features monitored (i.e. microbial biomass-C, total bacterial counts, dehydrogenase activity and AWCD) were significantly higher in the RM-soil. Bean germination was completely inhibited in RM-soil while wheat growth was similar to that of the control. The Al-OH treatment was best overall, promoting microbial abundance, diversity and activity while increasing bean and wheat growth and reducing As accumulated in plant shoots. Results suggest that Al-OH is a suitable candidate for field evaluations while the use of RM in the remediation of circumneutral or subalkaline contaminated soils should be reconsidered.

  12. Use of mycorrhizal fungi for the phyto stabilisation of radio contaminated environment (European project myrrh): overview on the scientific achievements

    Energy Technology Data Exchange (ETDEWEB)

    Dupre De Boulois, H.; Leyval, C.; Joner, E.J.; Jakobsen, I.; Chen, B.; Roos, P.; Thiry, I.; Rufyikiri, G.; Delvaux, B.; Declerck, S. [Universite catholique de Louvain, Mycotheque de l' Universite catholique de Louvain (MUCL), Unite de Microbiologie, Louvain-la-Neuve (Belgium)

    2004-07-01

    Because plants significantly affect radionuclides (RN) cycling and further dispersion into the biosphere, it is important to understand the biological factors influencing RN plant uptake, accumulation and redistribution. In this respect, mycorrhizal fungi which are intimately associated with plant roots and constitute an active continuum at the soil-plant interface are of particular interest. The European project MYRRH (Use of Mycorrhizal fungi for the phyto-stabilisation of radio-contaminated environment) was aimed to highlight the role of these soil micro-organisms. Both ectomycorrhizal (ECM) and arbuscular mycorrhizal (AM) fungi were considered and experiments were performed using naturally or artificially contaminated substrates with radiocaesium (Cs) or uranium (U) under pot culture or in vitro conditions. Results obtained under in vitro conditions demonstrated that AM fungal hyphae could take up and trans-locate Cs and U towards roots. However, this translocation was low for both elements. In particular, for Cs, uptake and translocation were not even perceptible using a classical pot culture system, but these contrasting results should be related to the growth conditions (e.g. concentration of potassium) used. The efficiency of translocation (rate of translocation per unit area) of both elements under in vitro conditions was higher than the one of roots. The in vitro studies also showed that the intra-radical AM fungal structures might contribute to Cs and U accumulation within mycorrhizal roots. Under pot culture conditions, AM fungi appeared to significantly reduce root to shoot translocation of U. Under the same conditions, ECM transport of Cs was demonstrated, and appeared to be dependent on the fungal species. As we established that mycorrhizal fungi could influence RN plant acquisition, accumulation and redistribution, a better estimation of the potential use of mycorrhizal fungi for the phyto-remediation of RN-contaminated areas is now available and

  13. Spinal segmental stabilisation exercises for chronic low back pain: programme adherence and its influence on clinical outcome.

    Science.gov (United States)

    Mannion, Anne F; Helbling, Daniel; Pulkovski, Natascha; Sprott, Haiko

    2009-12-01

    Exercise rehabilitation is one of the few evidence-based treatments for chronic non-specific low back pain (cLBP), but individual success is notoriously variable and may depend on the patient's adherence to the prescribed exercise regime. This prospective study examined factors associated with adherence and the relationship between adherence and outcome after a programme of physiotherapeutic spine stabilisation exercises. A total of 32/37 patients with cLBP completed the study (mean age, 44.0 (SD = 12.3) years; 11/32 (34%) male). Adherence to the 9-week programme was documented as: percent attendance at therapy, percent adherence to daily home exercises (patient diary) and percent commitment to rehabilitation (Sports Injury Rehabilitation Adherence Scale (SIRAS)). The average of these three measures formed a multidimensional adherence index (MAI). Psychological disturbance, fear-avoidance beliefs, catastrophising, exercise self-efficacy and health locus of control were measured by questionnaire; disability in everyday activities was scored with the Roland-Morris disability scale and back pain intensity with a 0-10 graphic rating scale. Overall, adherence to therapy was very good (average MAI score, 85%; median (IQR), 89 (15)%). The only psychological/beliefs variable showing a unique significant association with MAI was exercise self-efficacy (Rho = 0.36, P = 0.045). Pain intensity and self-rated disability decreased significantly after therapy (each P success of their own therapy, perhaps by increasing exercise self-efficacy. Whether the "adherence-outcome" interaction was mediated by improvements in function related to the specific exercises, or by a more "global" effect of the programme, remains to be examined.

  14. Mechanical and leaching behaviour of slag-cement and lime-activated slag stabilised/solidified contaminated soil.

    Science.gov (United States)

    Kogbara, Reginald B; Al-Tabbaa, Abir

    2011-05-01

    Stabilisation/solidification (S/S) is an effective technique for reducing the leachability of contaminants in soils. Very few studies have investigated the use of ground granulated blast furnace slag (GGBS) for S/S treatment of contaminated soils, although it has been shown to be effective in ground improvement. This study sought to investigate the potential of GGBS activated by cement and lime for S/S treatment of a mixed contaminated soil. A sandy soil spiked with 3000mg/kg each of a cocktail of heavy metals (Cd, Ni, Zn, Cu and Pb) and 10,000mg/kg of diesel was treated with binder blends of one part hydrated lime to four parts GGBS (lime-slag), and one part cement to nine parts GGBS (slag-cement). Three binder dosages, 5, 10 and 20% (m/m) were used and contaminated soil-cement samples were compacted to their optimum water contents. The effectiveness of the treatment was assessed using unconfined compressive strength (UCS), permeability and acid neutralisation capacity (ANC) tests with determination of contaminant leachability at the different acid additions. UCS values of up to 800kPa were recorded at 28days. The lowest coefficient of permeability recorded was 5×10(-9)m/s. With up to 20% binder dosage, the leachability of the contaminants was reduced to meet relevant environmental quality standards and landfill waste acceptance criteria. The pH-dependent leachability of the metals decreased over time. The results show that GGBS activated by cement and lime would be effective in reducing the leachability of contaminants in contaminated soils. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. The influence of patella height on soft tissue balance in cruciate-retaining and posterior-stabilised total knee arthroplasty.

    Science.gov (United States)

    Nishizawa, Yuichiro; Matsumoto, Tomoyuki; Kubo, Seiji; Muratsu, Hirotsugu; Matsushita, Takehiko; Oka, Shinya; Ishida, Kazunari; Matsuzaki, Tokio; Nishida, Kotaro; Akisue, Toshihiro; Kuroda, Ryosuke; Kurosaka, Masahiro

    2013-03-01

    Although the patella reduced or everted position has recently been recognised as an important factor influencing soft tissue balance during assessment in total knee arthroplasty (TKA), the influence of patella height on soft tissue balance has not been well addressed. Therefore, the relationship between soft tissue balance and patella height was investigated and differences between cruciate-retaining (CR) and posterior-stabilised (PS) TKA were compared. Forty consecutive patients blinded to the type of implant received, were randomised prospectively. Using lateral radiographs, pre-operative patella height was measured. Using an offset-type tensor designed to measure the soft tissue balance with a reduced patellofemoral (PF) joint and femoral component in place, soft tissue balance was intra-operatively assessed in CR TKA (n = 20) and PS TKA (n = 20) in osteoarthritic patients. The joint component gap and varus ligament balance at zero, ten, 45, 90 and 135° of knee flexion with the patella reduced were measured. In PS TKA, the joint component gap positively correlated with patella height at 90 and 135° of knee flexion. However, there was no correlation between joint component gap and patella height at other flexion angles in PS TKA and any flexion angle in CR TKA. Varus ligament balance showed no significant correlation with patella height in either CR or PS TKA. Analysis of soft tissue balance and patella height only showed a positive correlation in joint component gap at a high flexion angle (90 and 135°) in PS TKA but not in other parameters examined. Pre-operative measurement of patella height may be an important factor for predicting an intra-operative flexion gap in PS TKA.

  16. Chromatographic finger print analysis and lysosomal membrane stabilisation activity of active fraction of Alstonia scholaris leaf extract in arthritic rats

    Directory of Open Access Journals (Sweden)

    Swapnil Goyal

    2014-01-01

    Full Text Available Object: The present study was aimed to assess the anti-arthritic activity of chloroform fraction of Alstonia scholaris leaf extract against Freund′s complete adjuvant (FCA-induced arthritis in rats. Materials and Methods: The anti-inflammatory activity of various fractions of ethanolic extract of Alstonia scholaris at concentration of 100 mg/kg was studied using the carrageenan-induced inflammatory models. The chloroform fraction shows significant anti-inflammatory activity. The chloroform fraction was further studied for anti-arthritic activity and HPTLC fingerprint analysis. For anti-arthritic activity, the active chloroform fraction was administered at the concentrations of 50 and 100 mg/kg body weight. The effect of chloroform fraction on liver ALP, ACP and LDH levels of lysosomal enzymes of FCA arthritic animals were studied. Indomethacin and prednisolone (10 mg/kg was used as standard. HPTLC studies were carried out using CAMAG HPTLC system equipped with linomat IV applicator, TLC scanner; Reprostar 3 and WIN CATS-4 software were used. Results: The chloroform fraction at 100 mg/kg, showed maximum inhibition (34.16% of inflammation induced by carrageenan. In FCA-induced arthritis, the chloroform fraction showed a highly significant reduction in paw volume (50 mg/kg-72.71%; 100 mg/kg-74.35%. The levels of lysosomal enzymes were significantly decreased in the chloroform fraction-treated groups. Conclusion: The possible mechanism of action of the chloroform fraction of Alstonia scholaris leaf extract may be through its stabilising action on lysosomal membranes. Future studies will provide new insights into the anti-arthritic activity of Alstonia scholaris and isolation of compound from it may eventually lead to development of a new class of anti-arthritic agent.

  17. Changes in Soil Solution Cu and Zn Follogwing Application of Alkaline Stabilised Sewage Sludge and Gamma-Irradiation

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    A glasshouse pot experiment was conducted to study study changes in the solubility of copper and zinc in the soil-plant system follwing heavy application of sewage sludge and partial sterilisation of the sludge/soil mixture,A silghtly acid sandy loam was mixed with alkaline stabilised and composted urban sewage sludge solids ('Agri-Soil',180 t hm-2),and the soil/sludge mixture was γ-irradiated( 10 kGy).The contrasts without the application of sewage sludge and γ-irradiation were also included in the experiment.Perennial ryegrass(Lolium perenne,cv.Magella) was grown on irradiated and unirradiated soils for 50 days. Soil solution samples were obtained using soil suction samplers immediately before plant transplantation and every ten days thereafter.The soil solution smmples were used directly for determination of Cu and Zn,together with pH,electrical conductivity(EC) and absorbance at wavelength 360 nm(A360).Application of Agri-Soil led to a substantial increase in dissolved Cu and a significant derease in dissolved Zn in the soil solution and thess effect were accompanied by increased soil solution pH ,EC and A360 ,The alkaline sludge product(Agri-Soil) in combination with γ-irradiation also led to pronounced elevtion of Cu and A360 but a marked decline in EC, indicatig an increase in dissolvedorganic compounds and a decrease in the ionic strength of the soil solution ,The dissolved Cu and Zn,EC and A360 usually decreased while the ph increased fter plant growth for 50 days.

  18. Anatase-stabilised Al{sub x}Ti{sub 1−x}O{sub 2} photoanodes containing uniform spherical particles for efficient dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Bakhshayesh, A.M., E-mail: abakhsh4@uwo.ca; Farajisafiloo, N.

    2015-03-15

    Graphical abstract: - Highlights: • A novel gel was prepared for the deposition of uniform films. • The films are straightforwardly prepared by dip coating method. • The gel is composed of uniform spherical particles made of small nanoparticles. • Anatase-TiO{sub 2} phase was stabilised by Al introduction. • Cell efficiency was dramatically improved in the cell based on the stabilised gel. - Abstract: This paper reports a facile straightforward process for the deposition of uniform photoanode electrodes by a novel Al{sub x}Ti{sub 1−x}O{sub 2} gel for dye-sensitized solar cells (DSCs) applications. Highly crystalline anatase-TiO{sub 2} phase is stabilised by aluminium chloride at 500 °C. The electrodes are composed of uniform spherical particles with diameter around 3 μm, containing small nanoparticles with the average grain size of 40 nm, deposited by dip coating method. X-ray photoelectron spectroscopy (XPS) reveals that 0.5 at.% Al{sup 3+} was incorporated into titania crystal lattice and stabilised anatase phase by limiting the transformation from anatase to rutile phase. UV–vis spectra show that the stabilised-film has lower band gap energy than that of undoped-TiO{sub 2}, extending the absorption of TiO{sub 2} into visible region. Electrochemical impedance spectroscopy (EIS) demonstrates that the anatase-stabilised DSC enjoys less recombination and internal resistances, improving the photovoltaic performance of the cell. The anatase-stabilised DSC has higher power conversion efficiency of 7.52% than that of unstabilised cell (6.40%)

  19. Role of vegetation change in future climate under the A1B scenario and a climate stabilisation scenario, using the HadCM3C earth system model

    Directory of Open Access Journals (Sweden)

    P. D. Falloon

    2012-06-01

    Full Text Available The aim of our study was to use the coupled climate-carbon cycle model HadCM3C to quantify climate impact of ecosystem changes over recent decades and under future scenarios, due to changes in both atmospheric CO2 and surface albedo. We use two future scenarios – the IPCC SRES A1B scenario, and a climate stabilisation scenario (2C20, allowing us to assess the impact of climate mitigation on results. We performed a pair of simulations under each scenario – one in which vegetation was fixed at the initial state and one in which vegetation changes dynamically in response to climate change, as determined by the interactive vegetation model within HadCM3C.

    In our simulations with interactive vegetation, relatively small changes in global vegetation coverage were found, mainly dominated by increases in scrub and needleleaf trees at high latitudes and losses of broadleaf trees and grasses across the Amazon. Globally this led to a loss of terrestrial carbon, mainly from the soil. Global changes in carbon storage were related to the regional losses from the Amazon and gains at high latitude. Regional differences in carbon storage between the two scenarios were largely driven by the balance between warming-enhanced decomposition and altered vegetation growth. Globally, interactive vegetation reduced albedo acting to enhance albedo changes due to climate change. This was mainly related to the darker land surface over high latitudes (due to vegetation expansion, particularly during winter and spring; small increases in albedo occurred over the Amazon. As a result, there was a relatively small impact of vegetation change on most global annual mean climate variables, which was generally greater under A1B than 2C20, with markedly stronger local-to-regional and seasonal impacts. Globally, vegetation change amplified future annual temperature increases by 0.24 and 0.15 K (under A1B and 2C20, respectively and increased global precipitation

  20. Modificaciones del plano sagital cervical luego del tratamiento quirúrgico posterior en la escoliosis idiopática del adolescente Lenke 1. [Changes­ in­ the ­cervical ­alignment­ after­ posterior ­transpedicular­ instrumentation­ in ­Lenke ­type ­1.

    Directory of Open Access Journals (Sweden)

    Sebastian Solsona

    2014-08-01

    Full Text Available In­tro­duc­ción: Como la cifosis torácica y la lordosis cervical son directamente proporcionales, las modificaciones del plano sagital torácico impactarían sobre la columna cervical. Nuestro objetivo fue detectar cambios en el plano sagital cervical, a corto y mediano plazo, durante el tratamiento quirúrgico según una técnica posterior. Materiales ­y ­Métodos:­ Estudio retrospectivo radiográfico de tipo serie de casos, entre enero de 2005 y abril de 2009. Criterios de inclusión: escoliosis idiopática del adolescente Lenke 1, tratamiento por vía posterior con tornillos transpediculares. Seguimiento mínimo 2 años. Parámetros analizados: nivel Cobb, nivel de instrumentación proximal, densidad de implantes, lordosis cervical, cifosis torácica proximal, cifosis torácica principal, inclinación sagital T1, balance sagital global, balance sagital cervical. Análisis estadístico mediante ANOVA de muestras repetitivas y Tukey, con el programa Graph-Pad-Prism. Resultados: 25 pacientes. Seguimiento promedio 4,3 años. Cifosis torácica: media preoperatoria 26,8º, posoperatoria 20,6º. Efecto lordotizante después del tratamiento quirúrgico (p ≤0,001. La inclinación sagital T1 y la cifosis proximal T2-T5 (p ≤0,038 mostraron un incremento hacia el último control. El 72% presentaba rectificación o cifosis cervical antes de la cirugía. El 44% experimentó una mejoría hacia el último control. Los niveles de artrodesis más altos se correlacionaron con los casos que empeoraron su contorno sagital posoperatorio. Conclusiones:­ Nuestra técnica de corrección generó un efecto lordotizante torácico. Esto se tradujo, a mediano plazo, en un incremento de la retropulsión del tronco y rectificación o pérdida de la lordosis a nivel cervical.

  1. Treatment of the thoracolumbar spine fracture with posterior monosegment pedicle fixation and transpedicular impacted bone graft at injured level%单节段椎弓根固定椎体内打压植骨治疗胸腰椎压缩骨折

    Institute of Scientific and Technical Information of China (English)

    邢飞; 樊道斌; 陈宏赋; 张林胜; 朱敏

    2012-01-01

    Objective To explore the clinical effects of posterior monosegmental pedicle screw fixation in selective treatment of thoracolumbar vertebral fractures. Methods 15 patients with thoracolumbar fractures were treated with posterior monosegmental pedicle screw fixation and transpedicle impacted bone graft. The Cobb's angle and reduction of injured vertebral body height were observed. Results All cases were followed up for 6 ~ 18months. Clinical evaluation revealed that 11 cases had no pain, 4 cases with occasional pain but required no medication and all patients had a high level of satisfaction with the final results. Radiographic evaluation revealed reduction rate of the injured vertebral height was 95%. The Cobb's angle was restored from 14° ~25° to 3° ~8°. There was no implant breakage, and no signs of pseudoarthrosis were observed. Conclusions Posterior monosegmental fixation might be an adequate and effective procedure to be used in specific types of thoracolumbar spine fractures. Transpedicular impacted grafting after bone loss calculation combined with pedicle fixation has better biomechanical properties.%目的 探讨单节段椎弓根固定结合伤椎打压植骨治疗胸腰椎屈曲压缩骨折的疗效.方法 对15例胸腰椎压缩性骨折(Denis B型)患者行后路单节段经伤椎复位固定、经椎弓根伤椎打压植骨手术.测量术前术后Cobb角,计算伤椎高度恢复率,进行ODI评分,分析疗效.结果 15例患者均获随访,时间6~18个月.伤椎高度矫正率约95%,Cobb角由术前的14°~25°改善为术后的3°~8°.未出现内固定断裂、神经损伤等并发症.结论 单节段椎弓根固定椎体内植骨治疗胸腰椎压缩性骨折手术创伤小,仅固定1个运动节段;椎体内打压植骨有效解决椎体复位后产生的椎体内骨缺损.

  2. Nucleic acid binding properties of a helix stabilising nucleoid protein from the thermoacidophilic archaeon Sulfolobus acidocaldarius that condenses DNA into compact structures.

    Science.gov (United States)

    Celestina, F; Suryanarayana, T

    1995-12-01

    Helix stabilising nucleoid protein (HSNP-C') from an acidothermophilic archaeon Sulfolobus acidocaldarius has been characterised with respect to interaction with nucleic acids by gel retardation assay, binding to nucleic acid columns, fluorescence titrations and electron microscopy. The protein exists in solution as very large multimeric aggregates as indicated by cross-linking studies. The protein binds strongly and co-operatively to double stranded DNA. Electron microscopy of the complexes of the protein with DNA shows compact structures suggesting that the protein condenses DNA.

  3. Gamma irradiation of food contact plastics: identification of tin-containing intermediates in the degradation of organotin-stabilised PVC by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Allen, D.W.; Brooks, J.S.; Unwin, J.; McGuiness, J.D.

    1985-08-05

    A brief account is given of the use of radiation as a process for food preservation. In particular, the effect of radiation on food packaging plastic materials is considered. Results are presented for the effect of various doses of gamma radiation on PVC containing organotin stabilisers, showing the presence of varying amounts of intermediates and a steady increase in the amount of tin (IV) chloride. Thermal degradation produced only a trace of tin (IV) chloride, in contrast. The significance of the results is discussed.

  4. Spinal segmental stabilisation exercises for chronic low back pain: programme adherence and its influence on clinical outcome

    Science.gov (United States)

    Helbling, Daniel; Pulkovski, Natascha; Sprott, Haiko

    2009-01-01

    Exercise rehabilitation is one of the few evidence-based treatments for chronic non-specific low back pain (cLBP), but individual success is notoriously variable and may depend on the patient’s adherence to the prescribed exercise regime. This prospective study examined factors associated with adherence and the relationship between adherence and outcome after a programme of physiotherapeutic spine stabilisation exercises. A total of 32/37 patients with cLBP completed the study (mean age, 44.0 (SD = 12.3) years; 11/32 (34%) male). Adherence to the 9-week programme was documented as: percent attendance at therapy, percent adherence to daily home exercises (patient diary) and percent commitment to rehabilitation (Sports Injury Rehabilitation Adherence Scale (SIRAS)). The average of these three measures formed a multidimensional adherence index (MAI). Psychological disturbance, fear-avoidance beliefs, catastrophising, exercise self-efficacy and health locus of control were measured by questionnaire; disability in everyday activities was scored with the Roland–Morris disability scale and back pain intensity with a 0–10 graphic rating scale. Overall, adherence to therapy was very good (average MAI score, 85%; median (IQR), 89 (15)%). The only psychological/beliefs variable showing a unique significant association with MAI was exercise self-efficacy (Rho = 0.36, P = 0.045). Pain intensity and self-rated disability decreased significantly after therapy (each P exercises showed a moderate, positive correlation with the reduction in average pain (Rho = 0.54, P = 0.003) and disability (Rho = 0.38, P = 0.036); higher MAI scores were associated with greater reductions in average pain (Rho = 0.48, P = 0.008) and a (n.s.) tendency for greater reductions in disability (Rho = 0.32, P = 0.07) Neither attendance at therapy nor SIRAS were significantly related to any of the outcomes. The benefits of rehabilitation depended to a large extent on the patient

  5. European 'Stabilisation through Association'

    DEFF Research Database (Denmark)

    Rodt, Annemarie Peen

    ’s success in repeatedly reconciling a divided continent and complemented its efforts to build peace beyond its borders. But does the EU (continue to) deserve such praise? This contribution examines European peacebuilding from the early inte-gration of post-World War Two economies, through the uniting......In 2012 the Nobel Committee awarded the European Union (EU) its Peace Prize. It commemorated the building and sustaining of peace between Europeans, a process in which the Nobel Committee proposed that the EU and its predecessors had played an important part. It explicitly commen-ded the Union...

  6. Stabilising Fragile States

    Science.gov (United States)

    2011-01-01

    benefits of government—and to douse attempts by spoilers to fan grievances into a blaze of dissatisfaction .   The upshot is that there is a...there is less awareness of the steps needed to boost employment. Large-scale, labour -intensive, public-sector work programmes are the most...benefits. The tasks undertaken in public works schemes will normally be fairly straightforward labour -intensive roles (e.g., collecting garbage

  7. Stabilisation of Fe2O3-rich Perovskite Nanophase in Epitaxial Rare-earth Doped BiFeO3 Films.

    Science.gov (United States)

    Zhang, Huairuo; Reaney, Ian M; Marincel, Daniel M; Trolier-McKinstry, Susan; Ramasse, Quentin M; MacLaren, Ian; Findlay, Scott D; Fraleigh, Robert D; Ross, Ian M; Hu, Shunbo; Ren, Wei; Rainforth, W Mark

    2015-08-14

    Researchers have demonstrated that BiFeO3 exhibits ferroelectric hysteresis but none have shown a strong ferromagnetic response in either bulk or thin film without significant structural or compositional modification. When remanent magnetisations are observed in BiFeO3 based thin films, iron oxide second phases are often detected. Using aberration-corrected scanning transmission electron microscopy, atomic resolution electron energy loss spectrum-mapping and quantitative energy dispersive X-ray spectroscopy analysis, we reveal the existence of a new Fe2O3-rich perovskite nanophase, with an approximate formula (Fe0.6Bi0.25Nd0.15)(3+) Fe(3+)O3, formed within epitaxial Ti and Nd doped BiFeO3 perovskite films grown by pulsed laser deposition. The incorporation of Nd and Bi ions on the A-site and coherent growth with the matrix stabilise the Fe2O3-rich perovskite phase and preliminary density functional theory calculations suggest that it should have a ferrimagnetic response. Perovskite-structured Fe2O3 has been reported previously but never conclusively proven when fabricated at high-pressure high-temperature. This work suggests the incorporation of large A-site species may help stabilise perovskite-structured Fe2O3. This finding is therefore significant not only to the thin film but also to the high-pressure community.

  8. Evaluation of morphology, aggregation pattern and size-dependent drug-loading efficiency of gold nanoparticles stabilised with poly (2-vinyl pyridine)

    Science.gov (United States)

    Rahim, Sana; Ali, Syed Abid; Ahmed, Farid; Imran, Muhammad; Shah, Muhammad Raza; Malik, Muhammad Imran

    2017-07-01

    Presence of basic nitrogen throughout the chain of poly(2-vinylpyridine) make them alluring candidate for applications requiring chelation of heavy metals. In this study, we report the use of poly (2-vinylpyridine) (P2VP) homopolymers of varying molar masses for the stabilization of gold nanoparticles for the first time. A study based on AFM, DLS and UV-visible spectroscopy was conducted to establish a correlation of the molar mass of P2VP with the size and distribution of the gold nanoparticles. Systematic and gradual change in the absorbance intensity and shift in SPR band of gold nanoparticles were also observed upon variations in treatment temperature, concentration of polymer, residence time, pH, and electrolyte concentration. The results obtained by UV-visible spectroscopy, AFM and DLS are complementary. The size of the P2VP-stabilised AuNPs was found to be in the range of 20-130 nms. At last, the effect of the size of P2VP-stabilised AuNPs (directly related to the molar mass of P2VP) on the drug-loading efficiency is evaluated. [Figure not available: see fulltext.

  9. Bioaccumulation of metals in ryegrass (Lolium perenne L.) following the application of lime stabilised, thermally dried and anaerobically digested sewage sludge.

    Science.gov (United States)

    Healy, M G; Ryan, P C; Fenton, O; Peyton, D P; Wall, D P; Morrison, L

    2016-08-01

    The uptake and accumulation of metals in plants is a potential pathway for the transfer of environmental contaminants in the food chain, and poses potential health and environmental risks. In light of increased population growth and urbanisation, the safe disposal of sewage sludge, which can contain significant levels of toxic contaminants, remains an environmental challenge globally. The aims of this experiment were to apply municipal sludge, having undergone treatment by thermal drying, anaerobic digestion, and lime stabilisation, to permanent grassland in order to assess the bioaccumulation of metals (B, Al, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, As, Nb, Mo, Sb, Ba, W, Pb, Fe, Cd) by perennial ryegrass over a period of up to 18 weeks after application. The legislation currently prohibits use of grassland for fodder or grazing for at least three weeks after application of treated sewage sludge (biosolids). Five treatments were used: thermally dried (TD), anaerobically digested (AD) and lime stabilised (LS) sludge all from one wastewater treatment plant (WWTP), AD sludge from another WWTP, and a study control (grassland only, without application of biosolids). In general, there was no significant difference in metal content of the ryegrass between micro-plots that received treated municipal sludge and the control over the study duration. The metal content of the ryegrass was below the levels at which phytotoxicity occurs and below the maximum levels specified for animal feeds.

  10. Arthroscopic stabilisation of an acute acromioclavicular dislocation grade III in a patient with ectopic insertion of the pectoralis minor: technical considerations.

    Science.gov (United States)

    Minuesa-Asensio, Alvaro; Barrio-Asensio, Carmen; González-Gómez, Ignacio; Murillo-González, Jorge

    2016-07-01

    The different approaches used in arthroscopic stabilisation of the acromioclavicular joint are well known. However, and despite a great incidence of ectopic pectoralis minor insertion, an alternative choice for the use of arthroscopic portal has not being sufficiently described. Here, we describe a case of acute acromioclavicular dislocation grade III. The arthroscopic stabilisation was achieved using the TightRope (Arthrex, Naples, USA) implant. Through this technique, the approach to the articular portion of the coracoid process can be made intra-articularly or from the subacromial space. We accessed intra-articularly, by opening the rotator interval to reach the coracoid process from the joint cavity. After opening the rotator interval, an ectopic insertion of the pectoralis minor was observed. The choice of approach of the coracoid process from the subacromial space would have complicated the intervention, making it necessary to sever the ectopic tendon to complete the technique, lengthening the surgical time and increasing the chance of complications. For this reason, the use of a standard posterior portal providing intra-articular arthroscopic access through the rotator interval is recommended since the aforementioned anatomical variation is not infrequent. Level of evidence Therapeutic studies-investigating the results of treatment, Level V.

  11. Lithium choreography: intramolecular arylations of carbamate-stabilised carbanions and their mechanisms probed by in situ IR spectroscopy and DFT calculations.

    Science.gov (United States)

    Fournier, Anne M; Nichols, Christopher J; Vincent, Mark A; Hillier, Ian H; Clayden, Jonathan

    2012-12-14

    Deprotonation of O-allyl, O-propargyl or O-benzyl carbamates in the presence of a lithium counterion leads to carbamate-stabilised organolithium compounds that may be quenched with electrophiles. We now report that when the allylic, propargylic or benzylic carbamate bears an N-aryl substituent, an aryl migration takes place, leading to stereochemical inversion and C-arylation of the carbamate α to oxygen. The aryl migration is an intramolecular S(N) Ar reaction, despite the lack of anion-stabilising aryl substituents. Our in situ IR studies reveal a number of intermediates along the rearrangement pathway, including a "pre-lithiation complex," the deprotonated carbamate, the rearranged anion, and the final arylated carbamate. No evidence was obtained for a dearomatised intermediate during the aryl migration. DFT calculations predict that during the reaction the solvated Li cation moves from the carbanion centre, thus freeing its lone pair for nucleophilic attack on the remote phenyl ring. This charge separation leads to several alternative conformations. The one having Li(+) bound to the carbamate oxygen gives rise to the lowest-energy transition structure, and also leads to inversion of the configuration. In agreement with the IR studies, the DFT calculations fail to locate a dearomatised intermediate. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Declining and stabilising trends in prevalence of overweight and obesity in Dutch Turkish, Moroccanand South Asian children 3-16 years of age between 1999 and 2011 in the Netherlands

    NARCIS (Netherlands)

    Wilde, J.A. de; Verkerk, P.H.; Middelkoop, B.J.C.

    2014-01-01

    Objective: In many developed countries, overweight and obesity prevalence seems to stabilise. The aim of this study was to determine trends between 1999 and 2011 in overweight and obesity prevalence, and mean Body Mass Index (BMI) z-score in Dutch, Turkish, Moroccan and Surinamese South Asian

  13. Declining and stabilising trends in prevalence of overweight and obesity in Dutch Turkish, Moroccanand South Asian children 3-16 years of age between 1999 and 2011 in the Netherlands

    NARCIS (Netherlands)

    Wilde, J.A. de; Verkerk, P.H.; Middelkoop, B.J.C.

    2014-01-01

    Objective: In many developed countries, overweight and obesity prevalence seems to stabilise. The aim of this study was to determine trends between 1999 and 2011 in overweight and obesity prevalence, and mean Body Mass Index (BMI) z-score in Dutch, Turkish, Moroccan and Surinamese South Asian childr

  14. Une nouvelle technique de stabilisation en fréquence d'un laser sur une cavité de Fabry-Perot

    OpenAIRE

    1987-01-01

    Nous présentons une nouvelle méthode pour stabiliser la fréquence d'un laser sur le pic de transmission d'un résonateur de Fabry-Perot (F.P.). Au moyen d'un modulateur acousto-optique, on décale en fréquence une fraction du faisceau laser d'une quantité voisine de l'écart entre modes du F.P. Les faisceaux direct et décalé sont polarisés orthogonalement et appliqués à l'entrée du F.P. Les faisceaux transmis sont séparés par un prisme de Glan. En effectuant la différence entre ces deux pics de ...

  15. Défis à relever pour la politique budgétaire en Amérique latine en matière de stabilisation et de redistribution

    Directory of Open Access Journals (Sweden)

    Matthieu Llorca

    2016-01-01

    Full Text Available Cet article se propose d'étudier les réponses offertes par la politique fiscale en Amérique latine dans la situation actuelle " d'atterrissage en douceur ". En fait, il apparaît que la région est exposée à un risque de choc externe de pays développés et la Chine à un risque politique. Dans ces conditions, la politique fiscale a un rôle important à jouer pour gérer ces risques en se centrant sur ses fonctions de stabilisation et de distribution. En outre, nous proposons un système de plusieurs mesures pour chaque fonction. Enfin, nous démontrons que les pays latino-américains ne souffrent pas de contrainte du financement pour appliquer nos recommandations.

  16. Effects of xanthan-locust bean gum mixtures on the physicochemical properties and oxidative stability of whey protein stabilised oil-in-water emulsions.

    Science.gov (United States)

    Khouryieh, Hanna; Puli, Goutham; Williams, Kevin; Aramouni, Fadi

    2015-01-15

    The effects of xanthan gum (XG)-locust bean gum (LBG) mixtures (0.05, 0.1, 0.15, 0.2 and 0.5 wt%) on the physicochemical properties of whey protein isolate (WPI) stabilised oil-in-water (O/W) emulsions containing 20% v/v menhaden oil was investigated. At higher concentrations, the apparent viscosity of the emulsions containing XG/LBG mixtures was significantly higher (pbean gum showed the greatest phase separation, followed by XG. Microstructure images showed depletion flocculation at lower biopolymer concentrations, and thus led to an increase in creaming instability and apparent viscosity of the emulsions. Addition of 0.15, 0.2 and 0.5 wt% XG/LBG mixtures greatly decreased the creaming of the emulsions. The rate of lipid oxidation for 8-week storage was significantly lower (p<0.05) in emulsions containing XG/LBG mixtures than in emulsions containing either of the biopolymer alone.

  17. Stabilisation of tetravalent cerium in perchloric acid medium and measurement of the stability constants of its fluoride complexes using ion selective potentiometry.

    Science.gov (United States)

    Sawant, R M; Rastogi, R K; Mahajan, M A; Chaudhuri, N K

    1996-01-01

    The stability constants of the fluoride complexes of cerium(IV) in 1 M (HClO(4), NaClO(4)) medium have been measured potentiometrically using a fluoride ion-selective electrode. Quantitative oxidation of cerium to its tetravalent state and its stabilisation in the perchlorate medium were accomplished by oxidation with AgO followed by quick addition of a known amount of fluoride ion. This procedure ensures stability of the oxidation state and prevents hydrolysis and polymerisation of Ce(IV). Logarithms of the average values of beta(1), beta(2), beta(3) and beta(4) were estimated to be 7.57+/-0.04, 14.50+/-0.03, 20.13+/-0.37 and 24.14+/-0.10 respectively.

  18. On the use of the stabilised Q1P0 element for geodynamical simulations and why this is a bad choice for buyoancy-driven flows.

    Science.gov (United States)

    Thieulot, Cedric

    2016-04-01

    Many Finite Element geodynamical codes (Fullsack,1995; Zhong et al., 2000; Thieulot, 2011) are based on bi/tri­-linear velocity constant pressure element (commonly called Q1P0), because of its ease of programming and rather low memory footprint, despite the presence of (pressure) checker­board modes. However, it is long known that the Q1P0 is not inf­-sup stable and does not lend itself to the use of iterative solvers, which makes it a less­ than­ ideal candidate for high resolution 3D models. Other attempts were made more recently (Burstedde et al., 2013; Le Pourhiet et al., 2012) with the use of the stabilised Q1Q1 element (bi/tri­-linear velocity and pressure). This element, while also attractive from an implementation and memory standpoint, suffers a major drawback due to the artificial compressibility introduced by the polynomial projection stabilization. These observations have shifted part of the community towards the Finite Difference Method while the remaining part is now embracing inf­sup stable second­ order elements [May et al., 2015; Kronbichler,2012). Rather surprinsingly, a third option exists when it comes to first ­order elements in the form of the stabilised Q1P0 element, but virtually no literature exists concerning its use for geodynamical applications. I will then recall the specificity of the stabilisation and will carry out a series of benchmark experiments and geodynamical tests to assess its performance. While being shown to work as expected in benchmark experiments, the stabilised Q1P0 element turns out to introduce first-order numerical artefacts in the velocity and pressure solutions in the case of buoyancy-driven flows. Burstedde, C., Stadler, G., Alisic, L., Wilcox, L. C., Tan, E., Gurnis, M., & Ghattas, O. (2013). Large­scale adaptive mantle convection simulation. Geophysical Journal International, 192(3), 889­906. Fullsack, P. (1995). An arbitrary Lagrangian­Eulerian formulation for creeping flows and its application in

  19. Non-resonant wavelength modulation saturation spectroscopy in acetylene-filled hollow-core photonic bandgap fibres applied to modulation-free laser diode stabilisation.

    Science.gov (United States)

    Pineda-Vadillo, Pablo; Lynch, Michael; Charlton, Christy; Donegan, John F; Weldon, Vincent

    2009-12-07

    In this paper the application of Wavelength Modulation (WM) techniques to non-resonant saturation spectroscopy in acetylene-filled Hollow-Core Photonic Bandgap Fibres (HC-PBFs) and modulation-free Laser Diode (LD) frequency stabilisation is investigated. In the first part WM techniques are applied to non-resonant pump-probe saturation of acetylene overtone rotational transitions in a HC-PBF. A high-power DFB chip-on-carrier mounted LD is used in conjunction with a tuneable External Cavity Laser (ECL) and the main saturation parameters are characterized. In the second part a novel feedback system to stabilize the DFB emission wavelength based on the WM saturation results is implemented. Modulation-free locking of the DFB laser frequency to the narrow linewidth saturation feature is achieved for both constant and variable LD temperatures.

  20. Treatment of temporomandibular disorders with a combination of hard acrylic stabilisation appliance and a soft appliance in the opposing jaw. A retro- and prospective study.

    Science.gov (United States)

    Lindfors, Erik; Nilsson, Håkan; Helkimo, Martti; Magnusson, Tomas

    2008-01-01

    The aim of this study was to evaluate the treatment effect of a combined treatment with a stabilisation appliance and a soft appliance in the opposing jaw in patients refractory to previous TMD treatment. During a 5-year-period, 2001-2005, a total of 98 patients received the combined treatment at the Department of Stomatognathic Physiology, the Institute for Postgraduate Dental Education, Jönköping, Sweden. Before the patients received the combined treatment, they had already been given several different TMD treatments during a long period of time, either before referral or at the specialist clinic, with only minor or no effect on their TMD symptoms. The patients were followed prospectively (n=10), or analysed retrospectively (n=88). The data registered were gender, age, main indication for TMD treatment, number of visits to the clinic before and after the introduction of the combined treatment, as well as according to a clinical (Di) and anamnestic (Ai) dysfunction index. The most common causes for treatment in the retrospective material were problems of muscular origin and problems of both muscular and TMJ origin. In the prospective material, most of the patients had mainly muscular symptoms. Both the clinical and anamnestic dysfunction index decreased statistically significantly in the retrospective material after the introduction of the combined treatment. There was a numerical improvement of both indices also in the prospective material. In conclusion, the present investigation showed that a combined treatment with a hard acrylic stabilisation appliance and a soft appliance in the opposing jaw seems to give a remarkable improvement of TMD signs and symptoms in apparently therapy resistant TMD patients. General conclusions should, however, be made with caution due to the fact that the study did not include any control group. There is an obvious need for randomized controlled studies concerning the efficacy and effectiveness of the combined treatment presented

  1. Decreased prevalence of hypercholesterolaemia and stabilisation of obesity trends in 5-year-old children: possible effects of changed public health policies.

    Science.gov (United States)

    Sedej, Katarina; Kotnik, Primož; Avbelj Stefanija, Magdalena; Grošelj, Urh; Širca Čampa, Andreja; Lusa, Lara; Battelino, Tadej; Bratina, Nataša

    2014-02-01

    Overweight/obesity in children is a worldwide public health problem. Together with hypercholesterolaemia they are associated with early atherosclerotic complications. In this study, we aimed to investigate the anthropometric characteristics and total cholesterol (TC) levels in a population of 5-year-old children, to determine trends in the prevalence of overweight/obesity and hypercholesterolaemia in 5-year-old children over a period of 8 years (2001-2009) and to assess the impact of modified national nutritional guidelines for kindergartens implemented in 2005. Cross-sectional studies of overweight/obesity prevalence in the years 2001, 2003-2005 and 2009, and hypercholesterolaemia in years 2001 and 2009, in 5-year-old children. Altogether, 12 832 (6308 girls/6524 boys) children were included. Overweight/obesity was defined by IOTF criteria. Hypercholesterolaemia was defined by TC level >5 mmol/l. Multivariable logistic regression models were used. NO CORRELATION BETWEEN BMI VALUES AND TC LEVELS WAS FOUND. OVERWEIGHT AND OBESITY PREVALENCE WERE STABILISED FROM 2001 TO 2009 (ODDS RATIO (OR) (95% CI): 1.13 (0.99-1.3) and 1.13 (0.89-1.42) respectively). Girls were more frequently overweight/obese than boys (OR (95% CI): 0.71 (0.65-0.79) and 0.75 (0.64-0.89) respectively). Prevalence of hypercholesterolaemia significantly decreased from 2001 to 2009 (OR (95% CI): 0.47 (0.41-0.55)). It was less frequent in boys than in girls (OR (95% CI): O.7 (0.61-0.8)). This is the first study to describe a negative trend in the prevalence of hypercholesterolaemia in pre-pubertal children. In addition, the prevalence of overweight/obesity in these children has been stabilised. Nationwide changes in public health policies could have influenced these observations.

  2. Kangaroo mother method: randomised controlled trial of an alternative method of care for stabilised low-birthweight infants. Maternidad Isidro Ayora Study Team.

    Science.gov (United States)

    Sloan, N L; Camacho, L W; Rojas, E P; Stern, C

    1994-09-17

    Because resources for care of low-birthweight (LBW) infants in developing countries are scarce, the Kangaroo mother method (KMM) was developed. The infant is kept upright in skin-to-skin contact with the mother's breast. Previous studies reported several benefits with the KMM but interpretation of their findings is limited by small size and design weaknesses. We have done a longitudinal, randomised, controlled trial at the Isidro Ayora Maternity Hospital in Quito, Ecuador. Infants with LBW (< 2000 g) who satisfied out-of-risk criteria of tolerance of food and weight stabilisation were randomly assigned to KMM and control (standard incubator care) groups (n = 128 and 147, respectively). During 6 months of follow-up the KMM group had a significantly lower rate than the control group of serious illness (lower-respiratory-tract disorders, apnoea, aspiration, pneumonia, septicaemia, general infections; 7 [5%] vs 27 [18%], p < 0.002), although differences between the groups in less severe morbidity were not significant. There was no significant difference in growth or in the proportion of women breastfeeding, perhaps because the proportion breastfeeding was high in both groups owing to strong promotion. Mortality was the same in both groups; most deaths occurred during the stabilisation period before randomisation. KMM mothers made more unscheduled clinic visits than control mothers but their infants had fewer re-admissions and so the cost of care was lower with the KMM. Since the eligibility criteria excluded nearly 50% of LBW infants from the study, the KMM is not universally applicable to these infants. The benefits might be greater in populations where breastfeeding is not so common.

  3. Potential assessment of using fly ash as a binding agent for stabilization and solidification of dredged material; Potentialbedoemning av flygaskor som bindemedelskomponent foer stabilisering och solidifiering (s/s) av muddermassor

    Energy Technology Data Exchange (ETDEWEB)

    Wilhelmsson, Anna; Holm, Goeran; Lagerlund, Johan; Maijala, Aino; Macsik, Josef

    2010-04-15

    Over the next few years, about 200 000-800 000 m3 of contaminated sediments, with a muddy, slimy texture, high water ratio and low strength, shall be dredged annually in the development of ports and maintenance dredging of navigable waterways. Dumping at sea is limited since the dredged materials are contaminated. Land disposal requires transports and land area and is thus high in costs. In the construction of new port areas, large volumes of crushed rock, etc. are normally used as construction filling materials. These materials can be replaced by stabilised and solidified dredged materials, with modified geotechnical properties. The method of stabilising/solidifying (s/s) contaminated dredged materials has been used internationally for a long period of time, and, in more recent years, also in the Nordic countries. In Sweden, for instance, the Port of Gaevle and the Port of Oxeloesund have received permissions to reuse s/s-treated contaminated dredged materials in the port structures. Reuse of the stabilised/solidified masses in a geotechnical structure is supported by the new Framework Directive (2008/98/EC) on waste where great emphasis is placed on recycling. Within the project, fly ashes were inventoried with respect to suitability and availability. Five fly ashes, both individual fly ashes and mixtures of different fly ashes, were investigated in the laboratory as a binder component in a binder mix consisting of 50% cement, 20% Merit 5000 and 30% fly ash. Sediment from the Port of Gaevle were stabilised with a binder mixture amount of 150 kg/m3. Produced samples were examined in terms of strength, permeability and leaching. An assessment of the fly ashes' potential was performed based on technological, environmental and economical aspects, as well as market demand and the acceptance of stabilised and solidified dredged materials as construction material. The results show that fly ash, together in a binder mixture with construction cement and slag cement

  4. Posterior Debridement with Trans-Pedicular Screw Fixation For ...

    African Journals Online (AJOL)

    ... osteomyelitis includes antibiotics with or without surgical intervention. Debridement is warranted for the treatment of idiopathic spondylo-discitis in ... Objective: Was to evaluate the surgical outcome of idiopathic lumbar spondylodiscitis treated ... relieved of pain and fully active with improvement neurological deficits, while ...

  5. The effect of an external hip joint stabiliser on gait function after surgery for tumours located around the circumference of the pelvis: analysis of seven cases of internal hemipelvectomy or proximal femur resection.

    Science.gov (United States)

    Akiyama, Toru; Saita, Kazuo; Ogura, Koichi; Kawai, Akira; Imanishi, Jungo; Yazawa, Yasuo; Kawashima, Noritaka; Ogata, Toru

    2016-03-01

    Limb-sparing resection of malignant pelvic tumours provides the opportunity for patients to obtain better post-operative mobility. However, because few studies have examined in detail the gait function of patients following pelvic tumour resection, the factors affecting gait performance remain to be clarified. Here, with the laboratory-based computer-assisted gait analysis, we evaluated these patients' gait objectively and the impact of a hip-stabilising supporter on gait improvement was simultaneously examined. Three-dimensional gait analysis was performed to obtain cross-sectional data for seven post-operative patients (mean age, 42.7 years; range, 20-61 years) who underwent various types of resection, including P1/4 internal hemipelvectomy (IH), P1/2/3 IH, and proximal femur resection with prosthetic reconstruction. To assess the immediate effects of a hip joint stabiliser, we instructed subjects to walk at their self-selected preferred speed and compared gait parameters with and without use of the hip stabiliser. At baseline, the average walking speed was 0.75 m/s (95% CI 0.53-0.97). As shown by the intra-subject comparison, the hip stabiliser increased walking speed in all but one subject, increasing both temporal and spatial parameters. Ground reaction force of operated limbs increased for some subjects, while step length increased on at least one side in all subjects. Improvement in the gait parameters is indicative of better control provided by the external hip stabiliser over the affected limb. Moreover, our findings show the potential of a biomechanical approach to improve gait function following pelvic tumour resection.

  6. Microbial carbon recycling: an underestimated process controlling soil carbon dynamics

    Science.gov (United States)

    Basler, A.; Dippold, M.; Helfrich, M.; Dyckmans, J.

    2015-07-01

    The mean residence times (MRT) of different compound classes of soil organic matter (SOM) do not match their inherent recalcitrance to decomposition. One reason for this is the stabilisation within the soil matrix, but recycling, i.e. the reuse of "old" organic material to form new biomass may also play a role as it uncouples the residence times of organic matter from the lifetime of discrete molecules in soil. We analysed soil sugar dynamics in a natural 30 years old labelling experiment after a~wheat-maize vegetation change to determine the extent of recycling and stabilisation in plant and microbial derived sugars: while plant derived sugars are only affected by stabilisation processes, microbial sugars may be subject to both, stabilisation and recycling. To disentangle the dynamics of soil sugars, we separated different density fractions (free particulate organic matter (fPOM), light occluded particulate organic matter (≤1.6 g cm-3; oPOM1.6), dense occluded particulate organic matter (≤2 g cm-3; oPOM2) and mineral-associated organic matter (>2 g cm-3; Mineral)) of a~silty loam under long term wheat and maize cultivation. The isotopic signature of sugars was measured by high pressure liquid chromatography coupled to isotope ratio mass spectrometry (HPLC/IRMS), after hydrolysis with 4 M Trifluoroacetic acid (TFA). While apparent mean residence times (MRT) of sugars were comparable to total organic carbon in the bulk soil and mineral fraction, the apparent MRT of sugars in the oPOM fractions were considerably lower than those of the total carbon of these fractions. This indicates that oPOM formation was fuelled by microbial activity feeding on new plant input. In the bulk soil, mean residence times of the mainly plant derived xylose (xyl) were significantly lower than those of mainly microbial derived sugars like galactose (gal), rhamnose (rha), fucose (fuc), indicating that recycling of organic matter is an important factor regulating organic matter dynamics

  7. Problems raised by radioactive ion acceleration in the SPIRAL project. Accelerator tuning and stabilisation; Problemes poses par l`acceleration d`ions radioactifs dans le project SPIRAL. Reglage et stabilisation de l`accelerateur

    Energy Technology Data Exchange (ETDEWEB)

    Boy, L. [Paris-6 Univ., 75 (France)

    1997-12-31

    This study is related to the SPIRAL project. This facility uses a cyclotron to accelerate radioactive ion beams produced in a thick target by the Grant Accelerateur National d`Ions Lourds primary beam. The low intensity of radioactive beams and the mixing of several species imply special tuning methods and associated diagnostics. Also, a cyclotron and the beam line will be used to switch from this tuning beam to the radioactive one. We present a theoretical study and a numerical simulation of the tuning of five radioactive beams using three different methods. the beam dynamic is performed through the injection beam line and the cyclotron up to the electrostatic deflector. Within the frame of these methods we have described all the SPIRAL beam diagnostics. Construction and test of a new low intensity diagnosis based on a plastic scintillator for phase measurement inside the cyclotron is described in details. (author). 63 refs.

  8. A comparative transmission electron microscopy, energy dispersive x-ray spectroscopy and spatially resolved micropillar compression study of the yttria partially stabilised zirconia - porcelain interface in dental prosthesis

    Energy Technology Data Exchange (ETDEWEB)

    Lunt, Alexander J.G., E-mail: alexander.lunt@chch.ox.ac.uk [Department of Engineering Science, University of Oxford, Parks Road, Oxford, Oxfordshire OX1 3PJ (United Kingdom); Mohanty, Gaurav, E-mail: gaurav.mohanty@empa.ch [EMPA Materials Science & Technology, Feuerwerkerstrasse 39, CH-3602 Thun (Switzerland); Ying, Siqi, E-mail: siqi.ying@eng.ox.ac.uk [Department of Engineering Science, University of Oxford, Parks Road, Oxford, Oxfordshire OX1 3PJ (United Kingdom); Dluhoš, Jiří, E-mail: jiri.dluhos@tescan.cz [TESCAN Brno, s.r.o., Libušina tř. 1, 623 00 Brno-Kohoutovice (Czech Republic); Sui, Tan, E-mail: tan.sui@eng.ox.ac.uk [Department of Engineering Science, University of Oxford, Parks Road, Oxford, Oxfordshire OX1 3PJ (United Kingdom); Neo, Tee K., E-mail: neophyte@singnet.com.sg [Specialist Dental Group, Mount Elizabeth Orchard, 3 Mount Elizabeth, #08-03/08-08/08-10, 228510 (Singapore); Michler, Johann, E-mail: johann.michler@empa.ch [EMPA Materials Science & Technology, Feuerwerkerstrasse 39, CH-3602 Thun (Switzerland); Korsunsky, Alexander M., E-mail: alexander.korsunsky@eng.ox.ac.uk [Department of Engineering Science, University of Oxford, Parks Road, Oxford, Oxfordshire OX1 3PJ (United Kingdom)

    2015-12-01

    Recent studies into the origins of failure of yttria partially stabilised zirconia–porcelain veneered prosthesis have revealed the importance of micro-to-nano scale characterisation of this interface zone. Current understanding suggests that the heat treatment, residual stresses and varying microstructure at this location may contribute to near-interface porcelain chipping. In this study the chemical, microstructural and mechanical property variation across the interfacial zone has been characterised at two differing length scales and using three independent techniques; energy dispersive X-ray spectroscopy, transmission electron microscopy and micropillar compression. Energy dispersive X-ray spectroscopy mapping of the near-interface region revealed, for the first time, that the diffusional lengths of twelve principal elements are limited to within 2–6 μm of the interface. This study also revealed that 0.2–2 μm diameter zirconia grains had become detached from the bulk and were embedded in the near-interface porcelain. Transmission electron microscopy analysis demonstrated the presence of nanoscale spherical features, indicative of tensile creep induced voiding, within the first 0.4–1.5 μm from the interface. Within zirconia, variations in grain size and atomistic structure were also observed within the 3 μm closest to the interface. Micropillar compression was performed over a 100 μm range on either side of the interface at the spatial resolution of 5 μm. This revealed an increase in zirconia and porcelain loading modulus at close proximities (< 5 μm) to the interface and a decrease in zirconia modulus at distances between 6 and 41 μm from this location. The combination of the three experimental techniques has revealed intricate details of the microstructural, chemical and consequently mechanical heterogeneities in the YPSZ–porcelain interface, and demonstrated that the length scales typically associated with this behaviour are approximately ± 5

  9. Slow conduction in the border zones of patchy fibrosis stabilises the drivers for atrial fibrillation: Insights from multi-scale human atrial modelling

    Directory of Open Access Journals (Sweden)

    Ross Morgan

    2016-10-01

    stabilised in fibrotic regions. The rotors propagated slowly around the border zones of patchy fibrosis (levels 3-4, failing to spread into inner areas of dense fibrosis.Conclusion. Rotors stabilise in the border zones of patchy fibrosis in 3D atria, where slow conduction enable the development of circuits within relatively small regions. Our results can provide a mechanistic explanation for the clinical efficacy of ablation around fibrotic regions.

  10. Aluminium hydroxide stabilised MnFe2O4 and Fe3O4 nanoparticles as dual-modality contrasts agent for MRI and PET imaging.

    Science.gov (United States)

    Cui, Xianjin; Belo, Salome; Krüger, Dirk; Yan, Yong; de Rosales, Rafael T M; Jauregui-Osoro, Maite; Ye, Haitao; Su, Shi; Mathe, Domokos; Kovács, Noémi; Horváth, Ildikó; Semjeni, Mariann; Sunassee, Kavitha; Szigeti, Krisztian; Green, Mark A; Blower, Philip J

    2014-07-01

    Magnetic nanoparticles (NPs) MnFe2O4 and Fe3O4 were stabilised by depositing an Al(OH)3 layer via a hydrolysis process. The particles displayed excellent colloidal stability in water and a high affinity to [(18)F]-fluoride and bisphosphonate groups. A high radiolabeling efficiency, 97% for (18)F-fluoride and 100% for (64)Cu-bisphosphonate conjugate, was achieved by simply incubating NPs with radioactivity solution at room temperature for 5 min. The properties of particles were strongly dependant on the thickness and hardness of the Al(OH)3 layer which could in turn be controlled by the hydrolysis method. The application of these Al(OH)3 coated magnetic NPs in molecular imaging has been further explored. The results demonstrated that these NPs are potential candidates as dual modal probes for MR and PET. In vivo PET imaging showed a slow release of (18)F from NPs, but no sign of efflux of (64)Cu.

  11. Hume-Rothery stabilisation mechanism and d-states-mediated Fermi surface-Brillouin zone interactions in structurally complex metallic alloys

    Science.gov (United States)

    Mizutani, U.; Inukai, M.; Sato, H.

    2011-07-01

    The stability of Co2Zn11 and Al8V5 gamma-brasses, both of which are composed of a transition metal element and polyvalent elements Zn or Al, can be discussed in terms of d-states-mediated Fermi surface-Brillouin zone (FsBz) interactions in the context of first-principles full-potential linearised augmented plane wave (FLAPW) band calculations. A FsBz-induced pseudogap is revealed in the FLAPW-Fourier spectrum, though it is hidden behind a much larger d-band in the total density of states. The stability range of three families of complex metallic alloys (CMAs) that include gamma-brasses, RT-, MI- and Tsai-type 1/1-1/1-1/1 approximants and 2/1-2/1-2/1 approximant, each of which is characterised by ? = 18, 50 and 125, respectively, can be well scaled in terms of the number of electrons per unit cell (e/uc) given by the product of the number of atoms per unit cell and the e/a value determined by the Hume-Rothery plot on the basis of the FLAPW-Fourier method. This is taken as the evidence for the justification of the Hume-Rothery stabilisation mechanism for all these CMAs having a pseudogap at the Fermi level.

  12. Stabilisation of the fractured fibula plays an important role in the treatment of pilon fractures: a retrospective comparison of fibular fixation methods.

    Science.gov (United States)

    Lee, Yih-Shiunn; Chen, Shu-Wen; Chen, Shih-Hao; Chen, Wen-Chiao; Lau, Ming-Jye; Hsu, Tzu-Liang

    2009-06-01

    Ninety-eight pilon fractures associated with ipsilateral distal fibular fracture were included in this study. The pilon fractures were treated by open reduction and plating. The 98 fractures were divided into three groups based on the treatment method of fractured fibula. Group A was composed of 50 fibular fractures treated by open reduction and plate fixation. Group B was composed of 23 fibular fractures treated by open reduction and pin fixation. Group C was composed of 25 fibular fractures treated conservatively by closed reduction. The radiographs were reviewed for adequacy of fracture reduction and posttraumatic arthrosis. At the end of follow-up, the clinical outcomes were evaluated using a rating scale. The three groups were similar in respect to Ruedi type, open fracture grade, and demographics (all p values >0.25). Group A showed a decreasing trend of malunion and ankle arthrosis compared to group C (p = 0.091 and p = 0.099, respectively). Group A had a better clinical outcome than group C (p = 0.008). In addition, group A showed an increasing trend of satisfactory outcome compared to group B (p = 0.096). In conclusion, for pilon fractures associated with ipsilateral fibular fractures, stabilisation of the fractured fibula plays an important role in the decrease of distal tibial malunion and post-traumatic ankle arthrosis as well as improvement of clinical outcomes.

  13. Solidification/stabilisation of metals contaminated industrial soil from former Zn smelter in Celje, Slovenia, using cement as a hydraulic binder.

    Science.gov (United States)

    Voglar, Grega E; Lestan, Domen

    2010-06-15

    In a laboratory study, Portland cement (15%, w/w) was used for solidification/stabilisation (S/S) of Cd, Pb, Zn, Cu, Ni and As contaminated soils from the former industrial site. Soils formed solid monoliths with cement. S/S effectiveness was assessed by measuring the mechanical strength of the monoliths, concentrations of metals in deionised water and TCLP (toxicity characteristic leaching procedure) soil extracts, and mass transfer of metals. Concentrations of Cd, Pb, Zn and Ni in water extracts from S/S soils generally decreased, concentrations of As remained unchanged, while concentrations of Cu increased. Concentrations of Cd, Pb, Zn and Ni in the TCLP extracts from S/S soils were lower than from original soils. Cu extractability was lower in most soil samples, while the extractability of As from S/S soils increased. Overall, the concentration of metals in deionised water and TCLP solution, obtained after extraction of the S/S soils, was below the regulatory limits. S/S greatly reduced the mass transfer of Cd (up to 83-times), Pb (up to 13.7-times) and Zn (up to 294-times). Mass transfer of Ni and As was generally also reduced, while that of Cu increased in some S/S soils. Based on the findings of mass-transfer mechanism analysis the predominant mechanism of release was surface wash-off of metals otherwise physically encapsulated within the cementous soil matrix. Copyright 2010 Elsevier B.V. All rights reserved.

  14. Thermal melt circular dichroism spectroscopic studies for identifying stabilising amphipathic molecules for the voltage-gated sodium channel NavMs.

    Science.gov (United States)

    Ireland, Sam M; Sula, Altin; Wallace, B A

    2017-09-19

    Purified integral membrane proteins require amphipathic molecules to maintain their solubility in aqueous solutions. These complexes, in turn, are used in studies to characterise the protein structures by a variety of biophysical and structural techniques, including spectroscopy, crystallography, and cryo-electron microscopy. Typically the amphilphiles used have been detergent molecules, but more recently they have included amphipols, which are polymers of different sizes and compositions designed to create smaller, more well-defined solubilised forms of the membrane proteins. In this study we used circular dichroism spectroscopy to compare the secondary structures and thermal stabilities of the NavMs voltage-gated sodium channel in different amphipols and detergents as a means of identifying amphipathic environments that maximally maintain the protein structure whilst providing a stabilising environment. These types of characterisations also have potential as means of screening for sample types that may be more suitable for crystallisation and/or cryo-electron microscopy structure determinations. © 2017 The Authors Biopolymers Published by Wiley Periodicals, Inc.

  15. Performance study and influence of radiation emission energy and soil contamination level on γ-radiation shielding of stabilised/solidified radionuclide-polluted soils.

    Science.gov (United States)

    Falciglia, Pietro P; Puccio, Valentina; Romano, Stefano; Vagliasindi, Federico G A

    2015-05-01

    This work focuses on the stabilisation/solidification (S/S) of radionuclide-polluted soils at different (232)Th levels using Portland cement alone and with barite aggregates. The potential of S/S was assessed applying a full testing protocol and calculating γ-radiation shielding (γRS) index, that included the measurement of soil radioactivity before and after the S/S as a function of the emission energy and soil contamination level. The results indicate that setting processes are strongly dependent on the contaminant concentration, and for contamination level higher than 5%, setting time values longer than 72 h. The addition of barite aggregates to the cement gout leads to a slight improvement of the S/S performance in terms of durability and contaminant leaching but reduces the mechanical resistance of the treated soils samples. Barite addition also causes an increase in the γ-rays shielding properties of the S/S treatment up to about 20%. Gamma-ray measurements show that γRS strongly depends on the energy, and that the radioactivity with the contamination level was governed by a linear trend, while, γRS index does not depend on the radionuclide concentration. Results allow the calculated γRS values and those available from other experiments to be applied to hazard radioactive soil contaminations.

  16. Problems of Instruments of Development of Local Self-Governance under Conditions of Ensuring Stabilisation of Economy

    Directory of Open Access Journals (Sweden)

    Golovnya Olena M.

    2013-11-01

    Full Text Available The article considers sustainable social development of local society as a universal technology. Such a technology covers all levels of management, creates conditions for the market and allows consolidation of various social groups. Technology is developed and realised under specific conditions and specific features of economic, organisational and socio-political levels and structure of development of a municipal society. Today, unfortunately, insufficient attentions is paid to the issues of constructing a complex of technologies capable of ensuring dynamic economic development of an integrated system of municipal management. Moreover, one of the directions of the municipal policy should be creation of a system of employment of population and re-training of employees and formation of new working places. Associations of local self-governance bodies could play a significant importance in protection of interests of territorial societies. In order to solve the issue of attraction of the population to participation in local self-governance, it is necessary to establish a feedback between the society and its self-governance bodies – both elected by citizens and its executive structures.

  17. Eco-evolutionary dynamics in a coevolving host-virus system.

    Science.gov (United States)

    Frickel, Jens; Sieber, Michael; Becks, Lutz

    2016-04-01

    Eco-evolutionary dynamics have been shown to be important for understanding population and community stability and their adaptive potential. However, coevolution in the framework of eco-evolutionary theory has not been addressed directly. Combining experiments with an algal host and its viral parasite, and mathematical model analyses we show eco-evolutionary dynamics in antagonistic coevolving populations. The interaction between antagonists initially resulted in arms race dynamics (ARD) with selective sweeps, causing oscillating host-virus population dynamics. However, ARD ended and populations stabilised after the evolution of a general resistant host, whereas a trade-off between host resistance and growth then maintained host diversity over time (trade-off driven dynamics). Most importantly, our study shows that the interaction between ecology and evolution had important consequences for the predictability of the mode and tempo of adaptive change and for the stability and adaptive potential of populations.

  18. Stabilisation of SWNTs by alkyl-sulfate chitosan derivatives of different molecular weight: towards the preparation of hybrids with anticoagulant properties

    Science.gov (United States)

    Fatouros, Dimitrios G.; Power, Kieron; Kadir, Omar; Dékány, Imre; Yannopoulos, Spyros N.; Bouropoulos, Nikolaos; Bakandritsos, Aristides; Antonijevic, Milan D.; Zouganelis, George D.; Roldo, Marta

    2011-03-01

    We have previously demonstrated that chitosan derivative N-octyl-O-sulfate chitosan (NOSC), which presents important pharmacological properties, can suspend single walled carbon nanotubes (SWNTs) up to 20 times more effectively than other chitosan derivatives in an aqueous environment. In an attempt to further investigate the impact of different molecular weights of chitosan to the solubilization and anticoagulant properties of these hybrids an array of NOSC derivatives varying their molecular weight (low, medium and high respectively) was synthesised and characterised by means of FT-IR spectroscopy, NMR spectroscopy and thermal gravimetric analysis (TGA). Microwave and nitric acid purified SWNTs, characterised by FT-IR spectroscopy, transmission electron microscopy (TEM) and Raman spectroscopy, were colloidally stabilised by these polymers and their anticoagulant activity was assessed. The results revealed that the low molecular weight NOSC coated SWNTs exhibit the highest activity when 0.5 mg mL-1 NOSC solutions are used, activity which is similar to that of the free polymer. Preliminary studies by exposure of these hybrids to Brine Shrimp (Artemia) cysts revealed no effect on the viability of sub-adult Artemia. Our findings suggest the possibility of tailoring these nanomaterials to bear the required properties for application as biocompatible building blocks for nanodevices including biosensors and biomaterials.We have previously demonstrated that chitosan derivative N-octyl-O-sulfate chitosan (NOSC), which presents important pharmacological properties, can suspend single walled carbon nanotubes (SWNTs) up to 20 times more effectively than other chitosan derivatives in an aqueous environment. In an attempt to further investigate the impact of different molecular weights of chitosan to the solubilization and anticoagulant properties of these hybrids an array of NOSC derivatives varying their molecular weight (low, medium and high respectively) was synthesised

  19. Acid test of joint technical and biological measures in slope stabilisation - Impact analysis of the heavy rainstorm event in August 2005

    Science.gov (United States)

    Graf, F.; Böll, A.

    2009-04-01

    The persisting and heavy rainstorms from 20th to 22nd August in 2005 resulted in loss of human lives and tremendous damage on infrastructure all over Switzerland. Many of the measures taken hitherto to protect against such natural hazards were stressed to their limits or even beyond due to water saturation of the soils and extreme discharges of the torrents. This particular configuration offered the possibility to investigate the reliability of technical and biological measures taken within the scope of slope stabilisation, torrent and gully control. In the context of a joint project the ancient sliding area "Schwandrübi" in Dallenwil (Switzerland) providing joint technical and biological measures was chosen to address aspects concerning the reliability of technical supporting structures, the development of biological measures in the course of time and their performance under the extreme impact as well as the effects of biological measures on the stability of slopes. During 1981 and 1982 joint technical and biological measures had been taken on a large scale with minor follow-ups shortly after to stabilise the "Schwandrübi". The underlying strategy was based on several pilot surveys as thorough soil analysis, e.g. grain size distribution and determination of the angle of internal friction (Φ') related to the porosity (n) and the dry unit weight (γ), respectively. Basically, the spatial arrangement of the gabions was in accordance with the theoretical guidelines. However, based on the angle of internal friction (Φ') determined on the loose moraine soil material, it was not possible to meet the soil mechanical criterion of inclination between the constructions in all cases. Regardless of the extreme impact during the rainstorm (~100-year event), no serious damage occurred neither on the roughly 25-year old gabions nor on the torrent control structures. The recalculated peak discharge in the outlet channel was ~60 m3s-1 superimposed by high bed load

  20. Transverse and Quantum Effects in Light Control by Light; (A) Parallel Beams: Pump Dynamics for Three Level Superfluorescence; and (B) Counterflow Beams: An Algorithm for Transverse, Full Transient Effects in Optical Bi-Stability in a Fabryperot Cavity.

    Science.gov (United States)

    1983-01-01

    Collaborations: (i) Physics A. Dr. Charles M. Bowden (MICOM) - Two-level amplifier output stabilisation and three-ievel pump dynamics B. Professor Michael ...like a Foucault pendulum. (See Fig. 6b). The SF process is a unique macroscopic manifestation of quantum fluctuations, even though they are proportional...otherwise. (b) No level degeneracy, T2 = T2 =, KL = 0. (c) T2 = m. (d) T2 = . Ce) KL = 0. (f) KL 5. (g) No level degeneracy. Fig. 6b. Foucault pendulum co

  1. Electronic and vibrational properties of yttria-stabilised zirconia from first-principles for 10-40 mol% Y2O3

    Science.gov (United States)

    Cousland, G. P.; Cui, X. Y.; Ringer, S.; Smith, A. E.; Stampfl, A. P. J.; Stampfl, C. M.

    2014-11-01

    Density-functional theory calculations are performed to investigate the electronic and vibrational density-of-states (DOS) for a series of recently predicted stable and metastable structures of yttria-stabilised zirconia (YSZ) with yttria (Y2O3) concentrations of 14, 17 and 20 mol%. Analogous quantities are also studied for the so-called δ-phase, which forms for 40 mol% yttria, as well as for model structures with ≈10.3 mol% yttria. These calculated results, together with those for the cubic, tetragonal and monoclinic phases of ZrO2, afford a comparison of structural, electronic and vibrational properties as a function of yttria concentration. With increasing yttria content, the electronic DOS exhibit a decrease in the valence band-width (of about 2.0 eV relative to the cubic phase) and a corresponding increase of the band-gap of 0.73 eV (from cubic to 40 mol% yttria containing ZrO2). Regarding the vibrational DOS (vDOS), the addition of yttria causes the peaks in the vDOS of ZrO2 to become less distinct, reflecting the more dense occupation of states due to the larger number of atoms in each primitive cell, and to the lower symmetry. The vDOS of the various YSZ structures appear qualitatively similar with contributions from O atoms spanning the whole frequency range and cation related contributions present for frequencies < 40 - 45 meV. With increasing yttria content, more Zr atoms become seven-fold coordinated as in monoclinic ZrO2, concominantly the vDOS increasingly resembles that of m-ZrO2, but with notable contributions from Y atoms, which has a main peak at about 17 meV, similar to that of Zr atoms.

  2. Heat-stabilised rice bran consumption by colorectal cancer survivors modulates stool metabolite profiles and metabolic networks: a randomised controlled trial.

    Science.gov (United States)

    Brown, Dustin G; Borresen, Erica C; Brown, Regina J; Ryan, Elizabeth P

    2017-05-01

    Rice bran (RB) consumption has been shown to reduce colorectal cancer (CRC) growth in mice and modify the human stool microbiome. Changes in host and microbial metabolism induced by RB consumption was hypothesised to modulate the stool metabolite profile in favour of promoting gut health and inhibiting CRC growth. The objective was to integrate gut microbial metabolite profiles and identify metabolic pathway networks for CRC chemoprevention using non-targeted metabolomics. In all, nineteen CRC survivors participated in a parallel randomised controlled dietary intervention trial that included daily consumption of study-provided foods with heat-stabilised RB (30 g/d) or no additional ingredient (control). Stool samples were collected at baseline and 4 weeks and analysed using GC-MS and ultra-performance liquid chromatography-MS. Stool metabolomics revealed 93 significantly different metabolites in individuals consuming RB. A 264-fold increase in β-hydroxyisovaleroylcarnitine and 18-fold increase in β-hydroxyisovalerate exemplified changes in leucine, isoleucine and valine metabolism in the RB group. A total of thirty-nine stool metabolites were significantly different between RB and control groups, including increased hesperidin (28-fold) and narirutin (14-fold). Metabolic pathways impacted in the RB group over time included advanced glycation end products, steroids and bile acids. Fatty acid, leucine/valine and vitamin B6 metabolic pathways were increased in RB compared with control. There were 453 metabolites identified in the RB food metabolome, thirty-nine of which were identified in stool from RB consumers. RB consumption favourably modulated the stool metabolome of CRC survivors and these findings suggest the need for continued dietary CRC chemoprevention efforts.

  3. Study of stress relief cracking in titanium stabilized austenitic stainless steel; Etude de la fissuration differee par relaxation d'un acier inoxydable austenitique stabilise au titane

    Energy Technology Data Exchange (ETDEWEB)

    Chabaud-Reytier, M

    1999-07-01

    The heat affected zone (HAZ) of titanium stabilised austenitic stainless steel welds (AISI 321) may exhibit a serious form of intercrystalline cracking during service at high temperature. This type of cracking, called 'stress relief cracking', is known to be due to work hardening but also to ageing: a fine and abundant intragranular Ti(C,N) precipitation appears near the fusion line and modifies the mechanical behaviour of the HAZ. This study aims to better know the accused mechanism and to succeed in estimating the risk of such cracking in welded junctions of 321 stainless steel. To analyse this embrittlement mechanism, and to assess the lifetime of real components, different HAZ are simulated by heat treatments applied to the base material which is submitted to various cold rolling and ageing conditions in order to reproduce the HAZ microstructure. Then, we study the effects of work hardening and ageing on the titanium carbide precipitation, on the mechanical (tensile and creep) behaviour of the resulting material and on its stress relief cracking sensitivity. It is shown that work hardening is the main parameter of the mechanism and that ageing do not favour crack initiation although it leads to titanium carbide precipitation. The role of this precipitation is also discussed. Moreover, a creep damage model is identified by a local approach to fracture. Materials sensitive to stress relief cracking are selected. Then, creep tests are carried out on notched bars in order to quantify the intergranular damage of these different materials; afterwards, these measurements are combined with calculated mechanical fields. Finally, it is shown that the model gives good results to assess crack initiation for a compact tension (CT) specimen during relaxation tests, as well as for a notched tubular specimen tested at 600 deg. C under a steady torque. (author)

  4. Platelet Adhesion to Podoplanin Under Flow is Mediated by the Receptor CLEC-2 and Stabilised by Src/Syk-Dependent Platelet Signalling

    Science.gov (United States)

    Pollitt, Alice Y.; Lowe, Kate; Latif, Arusa; Nash, Gerard B.

    2015-01-01

    Summary Platelet-specific deletion of CLEC-2, which signals through Src and Syk kinases, or global deletion of its ligand podoplanin results in blood-filled lymphatics during mouse development. Platelet-specific Syk deficiency phenocopies this defect, indicating that platelet activation is required for lymphatic development. In the present study, we investigated whether CLEC-2-podoplanin interactions could support platelet arrest from blood flow and whether platelet signalling is required for stable platelet adhesion to lymphatic endothelial cells (LECs) and recombinant podoplanin under flow. Perfusion of human or mouse blood over human LEC monolayers led to platelet adhesion and aggregation. Following αIIbβ3 blockade, individual platelets still adhered. Platelet binding occurred at venous but not arterial shear rates. There was no adhesion using CLEC-2-deficient blood or to vascular endothelial cells (which lack podoplanin). Perfusion of human blood over human Fc-podoplanin (hFcPDPN) in the presence of monoclonal antibody IV.3 to block FcγRIIA receptors led to platelet arrest at similar shear rates to those used on LECs. Src and Syk inhibitors significantly reduced global adhesion of human or mouse platelets to LECs and hFcPDPN. A similar result was seen using Syk-deficient mouse platelets. Reduced platelet adhesion was due to a decrease in the stability of binding. In conclusion, our data reveal that CLEC-2 is an adhesive receptor that supports platelet arrest to podoplanin under venous shear. Src/Syk-dependent signalling stabilises platelet adhesion to podoplanin, providing a possible molecular mechanism contributing to the lymphatic defects of Syk-deficient mice. PMID:25694214

  5. Occurrence and removal of butyltin compounds in a waste stabilisation pond of a domestic waste water treatment plant of a rural French town.

    Science.gov (United States)

    Sabah, A; Bancon-Montigny, C; Rodier, C; Marchand, P; Delpoux, S; Ijjaali, M; Tournoud, M-G

    2016-02-01

    The aim of this study was to investigate the fate and behaviour of butyltin pollutants, including monobutyltin (MBT), dibutylin (DBT), and tributyltin (TBT), in waste stabilisation ponds (WSP). The study was conducted as part of a baseline survey and included five sampling campaigns comprising bottom sludge and the water column from each pond from a typical WSP in France. Butyltins were detected in all raw wastewater and effluents, reflecting their widespread use. Our results revealed high affinity between butyltins and particulate matter and high accumulation of butyltins in the sludge taken from anaerobic ponds. The dissolved butyltins in the influent ranged from 21.5 to 28.1 ng(Sn).L(-1) and in the effluent, from 8.8 to 29.3 ng(Sn).L(-1). The butyltin concentrations in the sludge ranged from 45.1 to 164 and 3.6-8.1 ng(Sn).g(-1) respectively in the first and last ponds. Our results showed an average treatment efficiency of 71% for MBT, 47% for DBT, 55% for TBT. Laboratory sorption experiments enabled the calculation of a distribution coefficient (Kd = 75,000 L.kg-1) between TBT and particulate matter from the WSPs. The Kd explained the accumulation and persistence of the TBT in the sludge after settling of particulate matter. The continuous supply of contaminated raw wastewater and the sorption-desorption processes in the ponds led to incomplete bio- and photolytic degradation and to the persistence of butyltins in dissolved and particulate matrices throughout the survey period. It is thus recommended to use shallow ponds and to pay particular attention when sludge is used for soil amendment.

  6. The 2.1 A resolution structure of cyanopindolol-bound β1-adrenoceptor identifies an intramembrane Na+ ion that stabilises the ligand-free receptor.

    Directory of Open Access Journals (Sweden)

    Jennifer L Miller-Gallacher

    Full Text Available The β1-adrenoceptor (β1AR is a G protein-coupled receptor (GPCR that is activated by the endogenous agonists adrenaline and noradrenaline. We have determined the structure of an ultra-thermostable β1AR mutant bound to the weak partial agonist cyanopindolol to 2.1 Å resolution. High-quality crystals (100 μm plates were grown in lipidic cubic phase without the assistance of a T4 lysozyme or BRIL fusion in cytoplasmic loop 3, which is commonly employed for GPCR crystallisation. An intramembrane Na+ ion was identified co-ordinated to Asp872.50, Ser1283.39 and 3 water molecules, which is part of a more extensive network of water molecules in a cavity formed between transmembrane helices 1, 2, 3, 6 and 7. Remarkably, this water network and Na+ ion is highly conserved between β1AR and the adenosine A2A receptor (rmsd of 0.3 Å, despite an overall rmsd of 2.4 Å for all Cα atoms and only 23% amino acid identity in the transmembrane regions. The affinity of agonist binding and nanobody Nb80 binding to β1AR is unaffected by Na+ ions, but the stability of the receptor is decreased by 7.5°C in the absence of Na+. Mutation of amino acid side chains that are involved in the co-ordination of either Na+ or water molecules in the network decreases the stability of β1AR by 5-10°C. The data suggest that the intramembrane Na+ and associated water network stabilise the ligand-free state of β1AR, but still permits the receptor to form the activated state which involves the collapse of the Na+ binding pocket on agonist binding.

  7. Stabilisation of a thin crystalline Si wafer solar cell using glass substrate; Duenne kristalline Silizium Wafer-Solarzelle mit Glastraeger stabilisiert

    Energy Technology Data Exchange (ETDEWEB)

    Muehlbauer, Maria

    2009-07-01

    An attempt was made to stabilise ultrathin crystalline silicon wafers (< 100 {mu}m) by a support material (BOROFLOAT33 by Schott Glas). It was found that the total serial resistance results mainly from the specific resistance of the back contact, and that especially the ultrathin solar cells have high recombination in the back. The ultrathin Si wafers also are slightly corrugated, which results in uneven joining of the Si wafer with the glass support. For optimisation, the solar cells of this specific types, with different thicknesses, were modelled in the one-dimensional simulation code PC1D, including all material-specific and electric properties. It was found that a slight reduction of the serial resistance will be enough for a significant improvement of the efficiency of the stabilized solar cell. With this knowledge, selective optimisation of the stabilised solar cells was possible, with the following results: 1. The improved temperature-time profile of the RTP step will improve the solar cell parameters for all Si thicknesses, which is assumed to be the result of better quality of the Al/Si back contact. 2. Thicker aluminium layers improved passivation on the back of solar cells with a thickness of 300 {mu}m and 120 {mu}m. In thinner stabilised solar cells, this measure resulted in enhanced formation of shunts and did not reduce the recombination rate on the back of the solar cell. 3. An additional optimisation step was the introduction of the so-called 'combined method' in which part of the aluminium layer is replaced by silkscreen paste. This combination, with adequate preparation, ensures uniform joining of the ultrathin silicon to the glass carrier. The resulting intermediate layers are highly homogeneous and have good fill factors and current densities for thin solar cells with a si thickness of 60 {mu}m. A decisive argument for the combined method is its near-100% reproducibility. [German] Ziel dieser Arbeit ist es sehr duenne kristalline

  8. Delay driven spatiotemporal chaos in single species population dynamics models.

    Science.gov (United States)

    Jankovic, Masha; Petrovskii, Sergei; Banerjee, Malay

    2016-08-01

    Questions surrounding the prevalence of complex population dynamics form one of the central themes in ecology. Limit cycles and spatiotemporal chaos are examples that have been widely recognised theoretically, although their importance and applicability to natural populations remains debatable. The ecological processes underlying such dynamics are thought to be numerous, though there seems to be consent as to delayed density dependence being one of the main driving forces. Indeed, time delay is a common feature of many ecological systems and can significantly influence population dynamics. In general, time delays may arise from inter- and intra-specific trophic interactions or population structure, however in the context of single species populations they are linked to more intrinsic biological phenomena such as gestation or resource regeneration. In this paper, we consider theoretically the spatiotemporal dynamics of a single species population using two different mathematical formulations. Firstly, we revisit the diffusive logistic equation in which the per capita growth is a function of some specified delayed argument. We then modify the model by incorporating a spatial convolution which results in a biologically more viable integro-differential model. Using the combination of analytical and numerical techniques, we investigate the effect of time delay on pattern formation. In particular, we show that for sufficiently large values of time delay the system's dynamics are indicative to spatiotemporal chaos. The chaotic dynamics arising in the wake of a travelling population front can be preceded by either a plateau corresponding to dynamical stabilisation of the unstable equilibrium or by periodic oscillations.

  9. Watching Nanoparticles Form: An In Situ (Small-/Wide-Angle X-ray Scattering/Total Scattering) Study of the Growth of Yttria-Stabilised Zirconia in Supercritical Fluids

    DEFF Research Database (Denmark)

    Tyrsted, Christoffer; Pauw, Brian; Jensen, Kirsten Marie Ørnsbjerg

    2012-01-01

    Understanding nanoparticle formation reactions requires multitechnique in situ characterisation, since no single characterisation technique provides adequate information. Here, the first combined small-angle X-ray scattering (SAXS)/wide-angle X-ray scattering (WAXS)/total-scattering study of nano...... of nanoparticle formation is presented. We report on the formation and growth of yttria-stabilised zirconia (YSZ) under the extreme conditions of supercritical methanol for particles with Y2O3 equivalent molar fractions of 0, 4, 8, 12 and 25%....

  10. Comparaison de méthodes de stabilisation pour alliages cuivreux exposés en extérieur au moyen d'un oxymètre

    OpenAIRE

    Uldry, Stéphanie

    2016-01-01

    Les objets d’art constitués d’alliages cuivreux se retrouvent dans une grande variété de collections patrimoniales, tel que les collections d’Antiquité, les collections d’objets techniques et scientifiques ou encore l’art moderne. Dans ce travail de Bachelor, nous allons nous intéresser plus particulièrement aux objets en bronze exposés en extérieur, tel que les statues, les sculptures ou encore les fontaines. L’étude présentée ici consiste à comparer un traitement de stabilisation pour les a...

  11. Vegetation Control in the Long-term Self-stabilisation of the Liangzhou Oasis of the Upper Shiyang River Watershed of West-central Gansu, NW China

    Science.gov (United States)

    Bourque, Charles; Hassan, Quazi

    2010-05-01

    in this presentation are most likely the same mechanisms that promote self-support and long-term stabilisation of the chain of oases along the base of the Qilian Mountains.

  12. Stabilisation problem in biaxial platform

    Directory of Open Access Journals (Sweden)

    Lindner Tymoteusz

    2016-12-01

    Full Text Available The article describes investigation of rolling ball stabilization problem on a biaxial platform. The aim of the control system proposed here is to stabilize ball moving on a plane in equilibrium point. The authors proposed a control algorithm based on cascade PID and they compared it with another control method. The article shows the results of the accuracy of ball stabilization and influence of applied filter on the signal waveform. The application used to detect the ball position measured by digital camera has been written using a cross platform .Net wrapper to the OpenCV image processing library - EmguCV. The authors used the bipolar stepper motor with dedicated electronic controller. The data between the computer and the designed controller are sent with use of the RS232 standard. The control stand is based on ATmega series microcontroller.

  13. Fiscal stabilisation in the EMU

    NARCIS (Netherlands)

    Aarle, B. van; Garretsen, J.H.

    1997-01-01

    This paper analyses the effects of macroeconomic shocks in a monetary union with the aid of a two-country model of the EMU. Our analysis serves two purposes. First, we show how asymmetries between countries might matter in terms of the resulting business cycle fluctuations. More specifically, we do

  14. Stabilisation problem in biaxial platform

    Science.gov (United States)

    Lindner, Tymoteusz; Rybarczyk, Dominik; Wyrwał, Daniel

    2016-12-01

    The article describes investigation of rolling ball stabilization problem on a biaxial platform. The aim of the control system proposed here is to stabilize ball moving on a plane in equilibrium point. The authors proposed a control algorithm based on cascade PID and they compared it with another control method. The article shows the results of the accuracy of ball stabilization and influence of applied filter on the signal waveform. The application used to detect the ball position measured by digital camera has been written using a cross platform .Net wrapper to the OpenCV image processing library - EmguCV. The authors used the bipolar stepper motor with dedicated electronic controller. The data between the computer and the designed controller are sent with use of the RS232 standard. The control stand is based on ATmega series microcontroller.

  15. Impact of biotic and abiotic processes on sediment dynamics and the consequences to the structure and functioning of the intertidal zone

    Science.gov (United States)

    Widdows, John; Brinsley, Mary

    2002-10-01

    This paper reviews field and laboratory studies using flumes to quantify the erodability of undisturbed intertidal sediments as a function of changes in (1) the natural benthic community structure and sediment properties, and (2) the abundance of key intertidal species. Sediment erodability, which varies spatially and temporally, is dependent on the interactions between physical processes, sediment properties and biological processes, particularly the balance between two functional groups of biota, the stabilisers and the destabilisers. Bio-stabilisers can influence the hydrodynamics and provide some physical protection to the bed (e.g. mussel beds, macroalgae, salt marsh macrophytes), or can enhance cohesiveness and alter the critical erosion threshold (e.g. microphytobenthos). In contrast, bio-destabilisers (e.g. bioturbators such as Macoma balthica, Hydrobia ulvae) increase surface roughness, reduce the critical erosion threshold and enhance the erosion rate. Field studies in the Humber (England) and Westerschelde (Netherlands) have shown that interannual changes in sediment erodability were a result of a shift from a stabilised sediment dominated by microphytobenthos to a destabilised sediment dominated by M. balthica. Interannual changes in key biota, their influence on sediment erosion, and the consequences for intertidal ecology and morphology, appear to be driven in part by climatic factors (primarily a shift from mild to cold winters). Quantification and understanding of these benthic processes has been used to parameterise mathematical models of intertidal sediment dynamics, and this has provided insight into the relative importance of biological and physical factors in determining sediment erosion/accretion in the intertidal zone.

  16. Conditional and unconditional Gaussian quantum dynamics

    Science.gov (United States)

    Genoni, Marco G.; Lami, Ludovico; Serafini, Alessio

    2016-07-01

    This article focuses on the general theory of open quantum systems in the Gaussian regime and explores a number of diverse ramifications and consequences of the theory. We shall first introduce the Gaussian framework in its full generality, including a classification of Gaussian (also known as 'general-dyne') quantum measurements. In doing so, we will give a compact proof for the parametrisation of the most general Gaussian completely positive map, which we believe to be missing in the existing literature. We will then move on to consider the linear coupling with a white noise bath, and derive the diffusion equations that describe the evolution of Gaussian states under such circumstances. Starting from these equations, we outline a constructive method to derive general master equations that apply outside the Gaussian regime. Next, we include the general-dyne monitoring of the environmental degrees of freedom and recover the Riccati equation for the conditional evolution of Gaussian states. Our derivation relies exclusively on the standard quantum mechanical update of the system state, through the evaluation of Gaussian overlaps. The parametrisation of the conditional dynamics we obtain is novel and, at variance with existing alternatives, directly ties in to physical detection schemes. We conclude our study with two examples of conditional dynamics that can be dealt with conveniently through our formalism, demonstrating how monitoring can suppress the noise in optical parametric processes as well as stabilise systems subject to diffusive scattering.

  17. Stabilisation goals for concentrations of climate-relevant gaseous emissions: Effects and emission pathways. Final report; Stabilisierungsziele fuer Treibhausgaskonzentrationen: Eine Abschaetzung der Auswirkungen und der Emissionspfade. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Onigkeit, J.; Alcamo, J.; Kaspar, F.; Roesch, T.

    2000-04-01

    Two different stabilisation goals were assumed, i.e. 550 ppm and 450 ppm of carbon dioxide. First, the global anthropogenic carbon dioxide emissions were calculated that are permissible to reach these goals. Secondly, the global and regional environmental effects of these concentration goals were assessed. In this, carbon dioxide, nitric oxides and methane emissions from power generation, industry and agriculture were considered. Apart from an investigation of the global reduction strategies required, a key was developed for sharing the global reduction loads between Annex B countries and non-Annex B countries. To reach a stable concentration of 550 ppm carbon dioxide in the atmosphere, the global anthropogenic carbon dioxide emissions per annum may increase slightly until 2030 but must be lowered to the 1990 level by 2100. In the case of 450 ppm, the 1990 level must even be halved by 2100. The consequences of climate change for agriculture, natural vegetation, availability of water, and sea levels were investigated in consideration of regional variations in carbon dioxide emissions and emission reduction measures. In spite of extensive emission control, the area of reduced agricultural productivity will grow rapidly in both cases, and natural vegetation will be endangered, although with strong regional variations. [German] Ausgehend von zwei langfristigen Klimaschutzzielen (Stabilisierung der atmosphaerischen CO{sub 2}-Konzentration bei 550 ppm und bei 450 ppm) wurde mit Hilfe des IMAGE 2.1 Modells: (1) Eine Berechnung der globalen anthropogenen Treibhausgasemissionen durchgefuehrt, die zwischen 1990 und 2100 erlaubt sind, um diese Konzentrationsziele zu erreichen. (2) Wurde eine Abschaetzung der globalen und regionalen Umweltauswirkungen durch den Klimawandel durchgefuehrt, der mit diesen Konzentrationszielen einhergeht. Bei der Analyse wurden CO{sub 2}-, N{sub 2}O- und CH{sub 4} Emissionen aus dem Energie/Industrie- und dem landwirtschaftlichen Sektor

  18. Dynamic Logics of Dynamical Systems

    CERN Document Server

    Platzer, André

    2012-01-01

    We survey dynamic logics for specifying and verifying properties of dynamical systems, including hybrid systems, distributed hybrid systems, and stochastic hybrid systems. A dynamic logic is a first-order modal logic with a pair of parametrized modal operators for each dynamical system to express necessary or possible properties of their transition behavior. Due to their full basis of first-order modal logic operators, dynamic logics can express a rich variety of system properties, including safety, controllability, reactivity, liveness, and quantified parametrized properties, even about relations between multiple dynamical systems. In this survey, we focus on some of the representatives of the family of differential dynamic logics, which share the ability to express properties of dynamical systems having continuous dynamics described by various forms of differential equations. We explain the dynamical system models, dynamic logics of dynamical systems, their semantics, their axiomatizations, and proof calcul...

  19. Influence of easily ionised elements on the delayed responses of the emission intensities of an analyte in a power modulated U-shaped argon stabilised DC arc plasma with an aerosol supply

    Directory of Open Access Journals (Sweden)

    MIROSLAV KUZMANOVIC

    2005-09-01

    Full Text Available The current of a U-shaped argon stabilised DC arc was square modulated with a 40 Hz repetition frequency between 6 and 3 A. The delayed line intensity responses to the modulation of the arc current were investigated using calcium as a representative analyte. The intensities of both the atomic and ionic lines were monitored at different distances from the arc axis in the presence of various concentrations of the easily ionised element. Temporal evolutions were monitored on a millisecond time scale. It was found that the responses of the line intesity to the arc current change strongly depended on the observed radial position, especially in the vicinity of the arc axis. The obtained results showed a significant influence of even small amounts of the easily ionised element on the excitation and transport of the analyte and indicated a way of possibly improving the analytical capabilities of the excitation source.

  20. A new pseudo-binary Mg{sub 6}Ni{sub 0.5}Pd{sub 0.5} intermetallic compound stabilised by Pd for hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, J.F., E-mail: josefrancisco.fernandez@uam.e [Dpto. Fisica de Materiales, Facultad de Ciencias, Universidad Autonoma de Madrid, 28049 Madrid (Spain); Cuevas, F. [CMTR/ICMPE/CNRS, 2-8 rue Henri Dunant, 94320 THIAIS Cedex (France); Leardini, F.; Bodega, J.; Ares, J.R. [Dpto. Fisica de Materiales, Facultad de Ciencias, Universidad Autonoma de Madrid, 28049 Madrid (Spain); Garces, G.; Perez, P. [Centro Nacional de Investigaciones Metalurgicas, CSIC, Av. Gregorio del Amo 8, 28040 Madrid (Spain); Sanchez, C. [Dpto. Fisica de Materiales, Facultad de Ciencias, Universidad Autonoma de Madrid, 28049 Madrid (Spain)

    2010-04-16

    The structural properties and chemical composition of a new pseudo-binary intermetallic compound Mg{sub 6.01}Ni{sub 0.43}Pd{sub 0.53} stabilised by Pd have been studied by X-ray Powder Diffraction and Scanning Electron Microscope coupled to Energy Dispersive X-ray analysis. The intermetallic compound is isomorphous to Mg{sub 6}Pd (Cubic system, F-43m space group) with a lattice parameter of 20.1373 A. The Mg atoms occupy the same atomic position than in Mg{sub 6}Pd while the Ni and Pd atoms share the 16e sites. The solubility limit of Ni in Mg{sub 6}Pd extents, at least, up to 11 wt%. The compound is stable up to melting which takes place at 800 K.

  1. Declining and stabilising trends in prevalence of overweight and obesity in Dutch, Turkish, Moroccan and South Asian children 3-16 years of age between 1999 and 2011 in the Netherlands.

    Science.gov (United States)

    de Wilde, J A; Verkerk, P H; Middelkoop, B J C

    2014-01-01

    In many developed countries, overweight and obesity prevalence seems to stabilise. The aim of this study was to determine trends between 1999 and 2011 in overweight and obesity prevalence, and mean Body Mass Index (BMI) z-score in Dutch, Turkish, Moroccan and Surinamese South Asian children in the Netherlands. A cross-sectional population-based study with 136 080 measurements of height and weight of 73 290 children aged 3-16 years. BMI class and BMI z-score were determined with the latest International Obesity Taskforce (IOTF) criteria, with overweight defined as an adult BMI equivalent ≥ 25 and obesity ≥ 30. Time trends per year were analysed using logistic and linear regression analyses. The prevalence of overweight in Dutch children declined from 13% to 11% (OR 0.960; 95% CI 0.954 to 0.965), but increased in Turkish children from 25% to 32% (OR 1.028; 95% CI 1.020 to 1.036). In Moroccan and Surinamese South Asian children, overweight rates were stable, but obesity prevalence decreased (OR 0.973; 95% CI 0.957 to 0.989, OR 0.964; 95% CI 0.943 to 0.985, respectively) as well as the mean BMI z-score (B=-0.010; 95% CI -0.014 to -0.006, B=-0.010; 95% CI -0.016 to -0.004). In Turkish children, trends limited to the period 2007-2011 showed no statistically significant relationship for all outcome measures. The decrease in obesity prevalence in Dutch, Moroccan and Surinamese South Asian children suggests that overweight children became less adipose. The stabilising trend in overweight and obesity prevalence in Turkish children since 2007 may signify a levelling off for this ethnic group.

  2. Generation and precise control of dynamic biochemical gradients for cellular assays

    CERN Document Server

    Saka, Yasushi; Giuraniuc, Claudiu V

    2016-01-01

    Spatial gradients of diffusible signalling molecules play crucial roles in controlling diverse cellular behaviour such as cell differentiation, tissue patterning and chemotaxis. Here we present a microfluidic platform for cellular assays that can generate and control diffusion-based gradients dynamically. A unique design of the device eliminates cross-flow between the source and sink channels, thereby stabilising gradients by passive diffusion. The platform also enables quick and flexible control of chemical concentration that makes highly dynamic gradients in diffusion chambers. Budding yeast cells cultured in a gradient of a chemical inducer expressed a reporter fluorescence protein in a concentration-dependent manner. This microfluidic platform serves as a versatile prototype applicable to a broad range of biomedical investigations.

  3. Intermediate fragmentation per se provides stable predator-prey metapopulation dynamics.

    Science.gov (United States)

    Cooper, Jennifer K; Li, Jiqiu; Montagnes, David J S

    2012-08-01

    The extent to which a landscape is fragmented affects persistence of predator-prey dynamics. Increasing fragmentation concomitantly imposes conditions that stabilise and destabilise metapopulations. For the first time, we explicitly assessed the hypothesis that intermediate levels provide optimal conditions for stability. We examine four structural changes arising from increased fragmentation: increased fragment number; decreased fragment size; increased connectedness (corridors scaled to fragment); increased fragment heterogeneity (based on connectedness). Using the model predator-prey system (Didinium-Paramecium) we support our hypothesis, by examining replicated metapopulations dynamics at five fragmentation levels. Although both species became extinct without fragmentation, prey survived at low and high levels, and both survived at intermediate levels. By examining time to extinction, maximum abundances, and population asynchrony we conclude that fragmentation produces structural heterogeneity (independent of environmental heterogeneity), which influences stability. Our analysis suggests why some theoretical, field and microcosm studies present conflicting views of fragmentation effects on population persistence.

  4. Dynamic Effects of Anchor Positional Tolerance on Tension Moored Floating Wind Turbine

    Science.gov (United States)

    Wright, Christopher; Pakrashi, Vikram; Murphy, Jimmy

    2016-09-01

    For water depths greater than 60m floating wind turbines will become the most economical option for generating offshore wind energy. Tension mooring stabilised units are one type of platform being considered by the offshore wind energy industry. The complex mooring arrangement used by this type of platform means that the dynamics are greatly effected by offsets in the positioning of the anchors. This paper examines the issue of tendon anchor position tolerances. The dynamic effects of three positional tolerances are analysed in survival state using the time domain FASTLink. The severe impact of worst case anchor positional offsets on platform and turbine survivability is shown. The worst anchor misposition combinations are highlighted and should be strongly avoided. Novel methods to mitigate this issue are presented.

  5. Avaliação clínica da vertebroplastia percutânea transpedicular Evaluación clinica de la vertebroplastia transpedicular percutánea Clinic evaluation of transpedicular percutaneous vertebroplasty

    Directory of Open Access Journals (Sweden)

    André Rafael Hubner

    2011-01-01

    Full Text Available OBJETIVO: Avaliar a eficácia do efeito analgésico da vertebroplastia com polimetilmetacrilato (PMMA e da estabilização vertebral obtida nos pacientes com fraturas vertebrais patológicas e realizar uma revisão detalhada da técnica da vertebroplastia percutânea, analisando suas indicações. MÉTODOS: Análise retrospectiva de 64 procedimentos de vertebroplastia percutânea em 46 pacientes. Foram realizadas avaliações dos prontuários e das radiografias pré e pós-operatórias e em nova consulta de rotina, na qual foi aplicado o questionário de dor (escala analógica visual da dor. RESULTADOS: Entre os 46 pacientes analisados, 37 (80,4% eram do sexo feminino e 9 (19,6% do sexo masculino, com média de idade de 71 anos (desvio-padrão +/- 9,2, variando de 50 a 90 anos. Foram operados 64 níveis, com predomínio do segmento toracolombar, sendo realizadas 17 (26,6% vertebroplastias a maioria em pedículos de T12. Trinta e um pacientes (67,4% apresentaram apenas um nível fraturado, 12 (26,1% apresentaram 02 níveis operados e três pacientes (6,5% apresentaram 03 ou mais níveis operados. O diagnóstico de osteoporose foi o mais comum (33 casos, 71,7%. Quanto ao alívio da dor no pós-operatório, houve um alto índice de satisfação de 90 a 100% em 37 (80% pacientes. CONCLUSÃO: A vertebroplastia demonstra ser um procedimento eficaz no tratamento da dor por fratura patológica de coluna, sendo tamb��m utilizada em investigação diagnóstica (biópsia óssea. É um procedimento seguro com baixas taxas de complicações.OBJETIVO: Evaluar la eficacia del efecto analgésico y estabilización vertebral de la vertebroplastia con polimetilmetacrilato (PMMA en pacientes con fracturas patológicas de la columna vertebral, y realizar una revisión detallada de la técnica de vertebroplastia percutánea, analizando sus indicaciones. MÉTODOS: Evaluación retrospectiva de 64 fracturas tratadas en 46 pacientes sometidos a vertebroplastia percutánea en el período de enero de 2000 a diciembre de 2008. Los pacientes fueron evaluados por las historias clínicas, por las radiografías pre y postoperatorias y consultas de rutina en las cuales se realizaron encuestas de dolor (escala universal visual del dolor. RESULTADOS: 37 (80,4% eran mujeres y 9 (19,6% eran varones, con edad promedio de 71 años (desvío estándar de + / - 9,2, que oscila entre 50 y 90 años. 64 niveles fueron operados, con predominio de lo segmento torácico-lumbar, se realizaron 17 (26,6% la mayoría en pedículos vertebroplastia de T12. Treinta y un pacientes (67,4% tenían sólo un nivel de fractura, 12 pacientes (26,1% tenían 02 niveles y 03 (6,5% pacientes tenían 03 o más niveles de fractura. El diagnóstico de osteoporosis fue el más común (33 casos, el 71,7%. Cuanto al alivio del dolor postoperatorio, hubo un alto índice de satisfacción de 90 a 100% en 37 (80% pacientes. CONCLUSIÓN: La vertebroplastia es un procedimiento que probó ser eficaz en el tratamiento del dolor por fractura patológica de la columna, y también se utiliza con fines de diagnóstico (biopsia de hueso. Es un procedimiento seguro y tiene bajas tasas de complicaciones.OBJECTIVE: This paper evaluates the analgesic effect and obtained vertebral stability of percutaneous vertebroplasty with polymethylmethacrylate (PMMA in patients with vertebral pathological fractures, and performs a detailed revision of this technique. METHODS: A retrospective analysis of 64 percutaneous vertebroplasty procedures in 46 patients was performed. Patients were evaluated by medical records, pre and post-operative radiographs, and by pain status (visual analog pain scale. RESULTS: 37 (80.4% patients were female and 9 (19.6% male, with mean age of 71 years (standard deviation + / - 9.2, ranging from 50 to 90 years. Sixty-four levels were treated, with a predominance of thoracic-lumbar segment, the majority 17 (26.6% of vertebroplaties at T12 pedicle. Thirty-one patients (67.4% presented only one fractured level, 12 patients (26.1% presented 02 levels and three (6.5% presented 03 or more treated levels. Osteoporosis was the most common diagnosis (33 cases, 71.7%. A high satisfaction rate of 90 to 100% was observed to the majority of patients when considering relief of pain postoperatively. CONCLUSIONS: Vertebroplasty has proven to be an effective procedure to treat pain caused by pathological fracture, and it is also used for diagnostic investigation (bone biopsy. The technique is secure and has provided low complications rates.

  6. Dynamical instabilities in disc-planet interactions

    CERN Document Server

    Lin, Min-Kai

    2012-01-01

    Protoplanetary discs may become dynamically unstable due to structure induced by an embedded giant planet. In this thesis, I discuss the stability of such systems and explore the consequence of instability on planetary migration. I begin with non-self-gravitating, low viscosity discs and show that giant planets induce shocks inside its co-orbital region, leading to a profile unstable to vortex formation around a potential vorticity minimum. This instability is commonly known as the vortex or Rossby wave instability. Vortex-planet interaction lead to episodic phases of migration, which can be understood in the framework of type III migration. I then examine the effect of disc self-gravity on gap stability. The linear theory of the Rossby wave instability is extended to include disc gravity, which shows that self-gravity is effective at stabilising the vortex instability at small azimuthal wavenumber. This is consistent with the observation that more vortices develop with increasing disc mass in hydrodynamic si...

  7. Dynamical Languages

    Science.gov (United States)

    Xie, Huimin

    The following sections are included: * Definition of Dynamical Languages * Distinct Excluded Blocks * Definition and Properties * L and L″ in Chomsky Hierarchy * A Natural Equivalence Relation * Symbolic Flows * Symbolic Flows and Dynamical Languages * Subshifts of Finite Type * Sofic Systems * Graphs and Dynamical Languages * Graphs and Shannon-Graphs * Transitive Languages * Topological Entropy

  8. The population dynamical consequences of density-dependent prophylaxis.

    Science.gov (United States)

    Reynolds, Jennifer J H; White, Andrew; Sherratt, Jonathan A; Boots, Mike

    2011-11-07

    When infectious disease transmission is density-dependent, the risk of infection will tend to increase with host population density. Since host defence mechanisms can be costly, individual hosts may benefit from increasing their investment in immunity in response to increasing population density. Such "density-dependent prophylaxis" (DDP) has now indeed been demonstrated experimentally in several species. However, it remains unclear how DDP will affect the population dynamics of the host-pathogen interaction, with previous theoretical work making conflicting predictions. We develop a general host-pathogen model and assess the role of DDP on the population dynamics. The ability of DDP to drive population cycles is critically dependent on the time delay between the change in density and the subsequent phenotypic change in the level of resistance. When the delay is absent or short, DDP destabilises the system. As the delay increases, its destabilising effect first diminishes and then DDP becomes increasingly stabilising. Our work highlights the significance of the time delay and suggests that it must be estimated experimentally or varied in theoretical investigations in order to understand the implications of DDP for the population dynamics of particular systems.

  9. New amphiphilic glycopolymers by click functionalization of random copolymers – application to the colloidal stabilisation of polymer nanoparticles and their interaction with concanavalin A lectin

    Directory of Open Access Journals (Sweden)

    Otman Otman

    2010-06-01

    Full Text Available Glycopolymers with mannose units were readily prepared by click chemistry of an azido mannopyranoside derivative and a poly(propargyl acrylate-co-N-vinyl pyrrolidone. These glycopolymers were used as polymer surfactants, in order to obtain glycosylated polycaprolactone nanoparticles. Optimum stabilization for long time storage was achieved by using a mixture of glycopolymers and the non-ionic triblock copolymer Pluronic® F-68. The mannose moieties are accessible at the surface of nanoparticles and available for molecular recognition by concanavalin A lectin. Interaction of mannose units with the lectin were evaluated by measuring the changes in nanoparticles size by dynamic light scattering in dilute media.

  10. First principles static and dynamic calculations for the transition metal hydride series MH4L3 (M = Fe, Ru and Os; L = NH3, PH3 and PF3).

    Science.gov (United States)

    Sieffert, Nicolas; Kendrick, Thomas; Tiana, Davide; Morrison, Carole A

    2015-03-07

    We present a first principles static and dynamical study of the transition metal hydride series MH4L3 (M = Fe, Ru and Os; L = NH3, PH3 and PF3), with a view to arriving at an understanding of how the variation in the electronic properties of the metal sites and ligands can influence the dynamics of the resulting complexes. A broad range of behaviour was observed, encompassing stable classical minima (M = Os, L = NH3 and M = Ru, L = PH3) to stable η(2)-H2 non-classical minima (M = Fe, L = PF3 and M = Ru, L = PH3 or PF3), with the other structures exhibiting dynamical behaviour that spontaneously converted between the classical and non-classical states during the molecular dynamics simulations. The importance of a small L(axial)-M-L(axial) angle in stabilising the non-classical state is highlighted, as is a short η(2)-H2···H(cis) distance in non-classical complexes that spontaneously convert to the classical form. We also investigated the changes in the electronic structure of the complex FeH4(PH3)3 during a η(2)-H2 bond breaking/bond making reaction and observed direct evidence of the 'cis effect', whereby a neighbouring hydride ligand acts to stabilise the intermediate classical state.

  11. Molecular dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Ladd, A.J.C.

    1988-08-01

    The basic methodology of equilibrium molecular dynamics is described. Examples from the literature are used to illustrate how molecular dynamics has been used to resolve theoretical controversies, provide data to test theories, and occasionally to discover new phenomena. The emphasis is on the application of molecular dynamics to an understanding of the microscopic physics underlying the transport properties of simple fluids. 98 refs., 4 figs.

  12. Application of a system dynamics approach for assessment and mitigation of CO{sub 2} emissions from the cement industry

    Energy Technology Data Exchange (ETDEWEB)

    Shalini Anand; Prem Vrat; R.P. Dahiya [Indian Institute of Technology Delhi, New Delhi (India). Centre for Energy Studies

    2006-06-15

    A system dynamics model based on the dynamic interactions among a number of system components is developed to estimate CO{sub 2} emissions from the cement industry in India. The CO{sub 2} emissions are projected to reach 396.89 million tonnes by the year 2020 if the existing cement making technological options are followed. Policy options of population growth stabilisation, energy conservation and structural management in cement manufacturing processes are incorporated for developing the CO{sub 2} mitigation scenarios. A 42% reduction in the CO{sub 2} emissions can be achieved in the year 2020 based on an integrated mitigation scenario. Indirect CO{sub 2} emissions from the transport of raw materials to the cement plants and finished product to market are also estimated.

  13. Dynamics Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Dynamics Lab replicates vibration environments for every Navy platform. Testing performed includes: Flight Clearance, Component Improvement, Qualification, Life...

  14. Dynamical systems

    CERN Document Server

    Sternberg, Shlomo

    2010-01-01

    Celebrated mathematician Shlomo Sternberg, a pioneer in the field of dynamical systems, created this modern one-semester introduction to the subject for his classes at Harvard University. Its wide-ranging treatment covers one-dimensional dynamics, differential equations, random walks, iterated function systems, symbolic dynamics, and Markov chains. Supplementary materials offer a variety of online components, including PowerPoint lecture slides for professors and MATLAB exercises.""Even though there are many dynamical systems books on the market, this book is bound to become a classic. The the

  15. Results and Conclusions of the Joint R.A.E./W.R.E. Research Programme on the Flight Dynamics and Ballistic Consistency of Freely Falling Missiles. Part 1. Bombs Stabilised by Fixed Cruciform Fins

    Science.gov (United States)

    1965-11-01

    range a little and the Reynolds numbers of the tesi the half scale 1823 shape were equal to those for full scale experimf between 30000 and 40000 ft...2670, 8 = 70 0.375 4210 S 79 L 94 Unsteady large incidence behaviour up to 25sc subsequent lock-in as above 0 - ’.7° 0 = )4 0. 0.50 445 S 150 L 10 Pasoed

  16. The effects of nutrient limitation (nitrogen and phosphorus) on BOD removal from post-coagulated Pinus radiata sulfite pulp and paper mill wastewater in a baffled aerated stabilisation basin-laboratory pilot scale study.

    Science.gov (United States)

    Dewi, R; Van Leeuwen, J A; Everson, A; Nothrop, S C; Chow, C W K

    2011-01-01

    The use of coagulation and flocculation for tertiary treatment of pulp and paper mill effluent was investigated, where the evaluation was based on the removal of nitrogen (N), phosphorus (P) and BOD from post-coagulated wastewater. The study was undertaken on laboratory scale aerobic stabilisation basins (ASB). Two post coagulated (alum) wastewaters were studied, where the BOD:N:P ratios were 100:1.3:0.06 and 100:1.3:0.3. These wastewaters were treated in two identical concurrent simulations (A & B). The influent ratio for 'A' was selected representing the composition of actual coagulated Pinus radiata sulfite pulp effluent mixed with paper mill effluent. The input composition for 'B' represented a typical P concentration found in existing pulp and paper mill effluents. Unmodified sludge collected from a mill-pond was added at 4% v/v to each simulation replicating the treatment conditions at full-scale. Similar high percentage removals of BOD and COD occurred after 28 days (two HRTs) which were 94 and 67% respectively for 'A', and 98 and 70% respectively for 'B', where both remained at steady state during the third HRT. A statistical analysis of the data revealed that there was no significant difference in the sample variance of the BOD and COD results.

  17. No statistically significant kinematic difference found between a cruciate-retaining and posterior-stabilised Triathlon knee arthroplasty: a laboratory study involving eight cadavers examining soft-tissue laxity.

    Science.gov (United States)

    Hunt, N C; Ghosh, K M; Blain, A P; Rushton, S P; Longstaff, L M; Deehan, D J

    2015-05-01

    The aim of this study was to compare the maximum laxity conferred by the cruciate-retaining (CR) and posterior-stabilised (PS) Triathlon single-radius total knee arthroplasty (TKA) for anterior drawer, varus-valgus opening and rotation in eight cadaver knees through a defined arc of flexion (0º to 110º). The null hypothesis was that the limits of laxity of CR- and PS-TKAs are not significantly different. The investigation was undertaken in eight loaded cadaver knees undergoing subjective stress testing using a measurement rig. Firstly the native knee was tested prior to preparation for CR-TKA and subsequently for PS-TKA implantation. Surgical navigation was used to track maximal displacements/rotations at 0º, 30º, 60º, 90º and 110° of flexion. Mixed-effects modelling was used to define the behaviour of the TKAs. The laxity measured for the CR- and PS-TKAs revealed no statistically significant differences over the studied flexion arc for the two versions of TKA. Compared with the native knee both TKAs exhibited slightly increased anterior drawer and decreased varus-valgus and internal-external roational laxities. We believe further study is required to define the clinical states for which the additional constraint offered by a PS-TKA implant may be beneficial.

  18. Nafion-stabilised bimetallic Pt–Cr nanoparticles as electrocatalysts for proton exchange membrane fuel cells (PEMFCs)† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c6ra16025e Click here for additional data file.

    Science.gov (United States)

    Gupta, G.; Sharma, S.

    2016-01-01

    The current study investigated the unique combination of alloying (Pt with Cr) and Nafion stabilisation to reap the benefits of catalyst systems with enhanced catalytic activity and improved durability in PEMFCs. Pt–Cr alloy nanoparticles stabilised with Nafion were chosen in the current study owing to their higher stability in acidic and oxidising media at high temperatures compared to other Pt-transition metal alloys (e.g. Pt–Ni, Pt–Co). Two different precursor : reducing agent (1 : 10 and 1 : 20) ratios were used in order to prepare two different alloys, denoted as Pt–Cr 10 and Pt–Cr 20. The Pt–Cr 20 alloy system (with composition Pt80Cr20) demonstrated higher electrocatalytic activity for the oxygen reduction reaction compared to commercial Pt/C (TKK) catalysts. Accelerated stress tests and single cell tests revealed that Nafion stabilised alloy catalyst systems displayed significantly enhanced durability (only ∼20% loss of ECSA) compared with Pt/C (50% loss of ECSA) due to improved catalyst–ionomer interaction. Furthermore, the Pt–Cr 20 alloy system demonstrated a current density comparable to that of Pt/C making them promising potential electrocatalysts for proton exchange membrane fuel cells.

  19. Molecular dynamics

    NARCIS (Netherlands)

    Bergstra, J.A.; Bethke, I.

    2002-01-01

    Molecular dynamics is a model for the structure and meaning of object based programming systems. In molecular dynamics the memory state of a system is modeled as a fluid consisting of a collection of molecules. Each molecule is a collection of atoms with bindings between them. A computation is model

  20. Dynamic Squares

    NARCIS (Netherlands)

    Blackburn, P.; Venema, Y.

    2008-01-01

    This paper examines various propositional logics in which the dynamic implication connective (discussed in Groenendijk and Stokhof's (1992) Dynamic Predicate Logic and Kamp's (1981) Discourse Representation Theory) plays the central role. Our approach is modal: the basic idea is to view as a binary

  1. Record dynamics

    DEFF Research Database (Denmark)

    Robe, Dominic M.; Boettcher, Stefan; Sibani, Paolo

    2016-01-01

    When quenched rapidly beyond their glass transition, colloidal suspensions fall out of equilibrium. The pace of their dynamics then slows down with the system age, i.e., with the time elapsed after the quench. This breaking of time translational invariance is associated with dynamical observables...

  2. Fluid Dynamics

    DEFF Research Database (Denmark)

    Brorsen, Michael

    These lecture notes are intended mainly for the 7th semester course "Fluid Dynamics" offered by the Study Committee on Civil Engineering, Aalborg University.......These lecture notes are intended mainly for the 7th semester course "Fluid Dynamics" offered by the Study Committee on Civil Engineering, Aalborg University....

  3. Persuasion dynamics

    Science.gov (United States)

    Weisbuch, Gérard; Deffuant, Guillaume; Amblard, Frédéric

    2005-08-01

    We here discuss a model of continuous opinion dynamics in which agents adjust continuous opinions as a result of random binary encounters whenever their difference in opinion is below a given threshold. We concentrate on the version of the model in the presence of few extremists which might drive the dynamics to generalized extremism. A network version of the dynamics is presented here, and its results are compared to those previously obtained for the full-mixing case. The same dynamical regimes are observed, but in rather different parameter regions. We here show that the combination of meso-scale features resulting from the first interaction steps determines the asymptotic state of the dynamics.

  4. Dynamic Optimization

    Science.gov (United States)

    Laird, Philip

    1992-01-01

    We distinguish static and dynamic optimization of programs: whereas static optimization modifies a program before runtime and is based only on its syntactical structure, dynamic optimization is based on the statistical properties of the input source and examples of program execution. Explanation-based generalization is a commonly used dynamic optimization method, but its effectiveness as a speedup-learning method is limited, in part because it fails to separate the learning process from the program transformation process. This paper describes a dynamic optimization technique called a learn-optimize cycle that first uses a learning element to uncover predictable patterns in the program execution and then uses an optimization algorithm to map these patterns into beneficial transformations. The technique has been used successfully for dynamic optimization of pure Prolog.

  5. Dynamic triggering

    Science.gov (United States)

    Hill, David P.; Prejean, Stephanie; Schubert, Gerald

    2015-01-01

    Dynamic stresses propagating as seismic waves from large earthquakes trigger a spectrum of responses at global distances. In addition to locally triggered earthquakes in a variety of tectonic environments, dynamic stresses trigger tectonic (nonvolcanic) tremor in the brittle–plastic transition zone along major plate-boundary faults, activity changes in hydrothermal and volcanic systems, and, in hydrologic domains, changes in spring discharge, water well levels, soil liquefaction, and the eruption of mud volcanoes. Surface waves with periods of 15–200 s are the most effective triggering agents; body-wave trigger is less frequent. Triggering dynamic stresses can be < 1 kPa.

  6. Galactic dynamics

    CERN Document Server

    Binney, James

    2008-01-01

    Since it was first published in 1987, Galactic Dynamics has become the most widely used advanced textbook on the structure and dynamics of galaxies and one of the most cited references in astrophysics. Now, in this extensively revised and updated edition, James Binney and Scott Tremaine describe the dramatic recent advances in this subject, making Galactic Dynamics the most authoritative introduction to galactic astrophysics available to advanced undergraduate students, graduate students, and researchers. Every part of the book has been thoroughly overhauled, and many section

  7. Dynamic capabilities

    DEFF Research Database (Denmark)

    Grünbaum, Niels Nolsøe; Stenger, Marianne

    2013-01-01

    it was dominated by a lack of systematism, assessment, monitoring, marketing speculations and feasibility calculation. Furthermore, the sphere was dictated by asymmetric supplier-customer relationships and negotiation power leading, among other possible factors, to meager profitability.......The consequences of dynamic capabilities (i.e. innovation performance and profitability) is an under researched area in the growing body of literature on dynamic capabilities and innovation management. This study aims to examine the relationship between dynamic capabilities, innovation performance...... and profitability of small and medium sized manufacturing enterprises operating in volatile environments. A multi-case study design was adopted as research strategy. The findings reveal a positive relationship between dynamic capabilities and innovation performance in the case companies, as we would expect. It was...

  8. The influence of vegetation dynamics on anthropogenic climate change

    Directory of Open Access Journals (Sweden)

    U. Port

    2012-11-01

    Full Text Available In this study, vegetation–climate and vegetation–carbon cycle interactions during anthropogenic climate change are assessed by using the Earth System Model of the Max Planck Institute for Meteorology (MPI ESM that includes vegetation dynamics and an interactive carbon cycle. We assume anthropogenic CO2 emissions according to the RCP 8.5 scenario in the time period from 1850 to 2120. For the time after 2120, we assume zero emissions to evaluate the response of the stabilising Earth System by 2300.

    Our results suggest that vegetation dynamics have a considerable influence on the changing global and regional climate. In the simulations, global mean tree cover extends by 2300 due to increased atmospheric CO2 concentration and global warming. Thus, land carbon uptake is higher and atmospheric CO2 concentration is lower by about 40 ppm when considering dynamic vegetation compared to the static pre-industrial vegetation cover. The reduced atmospheric CO2 concentration is equivalent to a lower global mean temperature. Moreover, biogeophysical effects of vegetation cover shifts influence the climate on a regional scale. Expanded tree cover in the northern high latitudes results in a reduced albedo and additional warming. In the Amazon region, declined tree cover causes a regional warming due to reduced evapotranspiration. As a net effect, vegetation dynamics have a slight attenuating effect on global climate change as the global climate cools by 0.22 K due to natural vegetation cover shifts in 2300.

  9. LEVEL OF EVIDENCE IN THE PLACEMENT OF TRANSPEDICULAR SCREWS IN SUBAXIAL CERVICAL SPINE

    Directory of Open Access Journals (Sweden)

    Cristóbal Herrera Palacios

    Full Text Available ABSTRACT The high-energy trauma mainly involves vertebral lesions and 6% occur in the cervical region. This poses a challenge to spine surgeons in surgical decision-making, both in terms of approach as the instrumentation. International recommendations establish that the procedures performed are reproducible, safe, and effective. The techniques for placement of pedicle screws are complicated and have been based on intraoperative navigation (limited by cost and fluoroscopy (greater exposure of health care professionals and patients to radiation. Therefore, the freehand technique is an option. The goal was to identify the level of evidence and grade of recommendation in the medical literature regarding the safety and efficacy of pedicle screw instrumentation with freehand technique in subaxial cervical spine. To this end, we carried out a systematic review with the following MeSH terms: safety, efficacy, vertebral artery. Articles were evaluated twice in a standardized and blind way by two observers skilled in systematic analysis, after CLEIS 3401 authorization in November 2014. Due to the nature of the study and the variables, articles with a high level of evidence and grade of recommendation were not found. Level of Evidence obtained on safety and efficacy in the placement of pedicle screws in subaxial column with freehand technique: 2b. Degree of Recommendation obtained on safety and efficacy in the placement of pedicle screws in subaxial column with freehand technique: B, favorable recommendation.

  10. Jumping Dynamics

    DEFF Research Database (Denmark)

    Sannino, Francesco

    2013-01-01

    We propose an alternative paradigm to the conjectured Miransky scaling potentially underlying the physics describing the transition from the conformally broken to the conformally restored phase when tuning certain parameters such as the number of flavors in gauge theories. According to the new...... paradigm the physical scale and henceforth also the massive spectrum of the theory jump at the lower boundary of the conformal window. In particular we propose that a theory can suddenly jump from a Quantum Chromodynamics type spectrum, at the lower boundary of the conformal window, to a conformal one...... without particle interpretation. The jumping scenario, therefore, does not support a near-conformal dynamics of walking type. We will also discuss the impact of jumping dynamics on the construction of models of dynamical electroweak symmetry breaking....

  11. Dynamic Bifurcations

    CERN Document Server

    1991-01-01

    Dynamical Bifurcation Theory is concerned with the phenomena that occur in one parameter families of dynamical systems (usually ordinary differential equations), when the parameter is a slowly varying function of time. During the last decade these phenomena were observed and studied by many mathematicians, both pure and applied, from eastern and western countries, using classical and nonstandard analysis. It is the purpose of this book to give an account of these developments. The first paper, by C. Lobry, is an introduction: the reader will find here an explanation of the problems and some easy examples; this paper also explains the role of each of the other paper within the volume and their relationship to one another. CONTENTS: C. Lobry: Dynamic Bifurcations.- T. Erneux, E.L. Reiss, L.J. Holden, M. Georgiou: Slow Passage through Bifurcation and Limit Points. Asymptotic Theory and Applications.- M. Canalis-Durand: Formal Expansion of van der Pol Equation Canard Solutions are Gevrey.- V. Gautheron, E. Isambe...

  12. Dynamical systems

    CERN Document Server

    Birkhoff, George D

    1927-01-01

    His research in dynamics constitutes the middle period of Birkhoff's scientific career, that of maturity and greatest power. -Yearbook of the American Philosophical Society The author's great book€¦is well known to all, and the diverse active modern developments in mathematics which have been inspired by this volume bear the most eloquent testimony to its quality and influence. -Zentralblatt MATH In 1927, G. D. Birkhoff wrote a remarkable treatise on the theory of dynamical systems that would inspire many later mathematicians to do great work. To a large extent, Birkhoff was writing about his o

  13. Forest dynamics.

    Science.gov (United States)

    Frelich, Lee

    2016-01-01

    Forest dynamics encompass changes in stand structure, species composition, and species interactions with disturbance and environment over a range of spatial and temporal scales. For convenience, spatial scale is defined as individual tree, neighborhood, stand, and landscape. Whether a given canopy-leveling disturbance will initiate a sequence of development in structure with little change in composition or initiate an episode of succession depends on a match or mismatch, respectively, with traits of the dominant tree species that allow the species to survive disturbance. When these match, certain species-disturbance type combinations lock in a pattern of stand and landscape dynamics that can persist for several generations of trees; thus, dominant tree species regulate, as well as respond to, disturbance. A complex interaction among tree species, neighborhood effects, disturbance type and severity, landform, and soils determines how stands of differing composition form and the mosaic of stands that compose the landscape. Neighborhood effects (e.g., serotinous seed rain, sprouting, shading, leaf-litter chemistry, and leaf-litter physical properties) operate at small spatial extents of the individual tree and its neighbors but play a central role in forest dynamics by contributing to patch formation at stand scales and dynamics of the entire landscape. Dominance by tree species with neutral to negative neighborhood effects leads to unstable landscape dynamics in disturbance-prone regions, wherein most stands are undergoing succession; stability can only occur under very low-severity disturbance regimes. Dominance by species with positive effects leads to stable landscape dynamics wherein only a small proportion of stands undergo succession at any one time. Positive neighborhood effects are common in temperate and boreal zones, whereas negative effects are more common in tropical climates. Landscapes with positive dynamics have alternate categories of dynamics

  14. Internetwork dynamics

    NARCIS (Netherlands)

    Rutten, R.J.

    1995-01-01

    This review places current research in quiet-Sun chromospheric dynamics in the context of past and future work, concentrating on observational aspects of three-minute oscillations and Ca II K2V grains. The subject is of interest at present because observations and simulations come together to permit

  15. Structural dynamics

    CERN Document Server

    Strømmen, Einar N

    2014-01-01

    This book introduces to the theory of structural dynamics, with focus on civil engineering structures that may be described by line-like beam or beam-column type of systems, or by a system of rectangular plates. Throughout this book the mathematical presentation contains a classical analytical description as well as a description in a discrete finite element format, covering the mathematical development from basic assumptions to the final equations ready for practical dynamic response predictions. Solutions are presented in time domain as well as in frequency domain. Structural Dynamics starts off at a basic level and step by step brings the reader up to a level where the necessary safety considerations to wind or horizontal ground motion induced dynamic design problems can be performed. The special theory of the tuned mass damper has been given a comprehensive treatment, as this is a theory not fully covered elsewhere. For the same reason a chapter on the problem of moving loads on beams has been included.

  16. Coastal Dynamics

    NARCIS (Netherlands)

    Bakker, W.T.

    1998-01-01

    This book deals on "Coastal Dynamics", which will be defined in a narrow sense as a mathematical theory, which starts from given equations of motion for the sediment, which leads with the continuity equation and given boundary conditions to a calculated (eventually schematized) coastal topography,

  17. Membrane dynamics

    DEFF Research Database (Denmark)

    Bendix, Pól Martin

    2015-01-01

    Current topics include membrane-protein interactions with regard to membrane deformation or curvature sensing by BAR domains. Also, we study the dynamics of membrane tubes of both cells and simple model membrane tubes. Finally, we study membrane phase behavior which has important implications...... for the lateral organization of membranes as wells as for physical properties like bending, permeability and elasticity...

  18. Glassy Dynamics

    DEFF Research Database (Denmark)

    Jensen, Henrik J.; Sibani, Paolo

    2007-01-01

    The term glassy dynamics is often used to refer to the extremely slow relaxation observed in several types of many component systems. The time span needed to reach a steady, time independent, state will typically be far beyond experimentally accessible time scales. When melted alloys are cooled d...

  19. Dynamic LIMIDS

    NARCIS (Netherlands)

    Díez, F.J.; Gerven, M.A.J. van

    2011-01-01

    One of the objectives of artificial intelligence is to build decision-support models for systems that evolve over time and include several types of uncertainty. Dynamic limited-memory influence diagrams (DLIMIDs) are a new type of model proposed recently for this kind of problems. DLIMIDs are simila

  20. Dynamic LIMIDS

    NARCIS (Netherlands)

    Díez, F.J.; Gerven, M.A.J. van

    2011-01-01

    One of the objectives of artificial intelligence is to build decision-support models for systems that evolve over time and include several types of uncertainty. Dynamic limited-memory influence diagrams (DLIMIDs) are a new type of model proposed recently for this kind of problems. DLIMIDs are simila