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Sample records for preoperative fulcrum bending

  1. Coronal plane segmental flexibility in thoracic adolescent idiopathic scoliosis assessed by fulcrum-bending radiographs.

    Science.gov (United States)

    Hasler, Carol-Claudius; Hefti, Fritz; Büchler, Philippe

    2010-05-01

    Knowledge about segmental flexibility in adolescent idiopathic scoliosis is crucial for a better biomechanical understanding, particularly for the development of fusionless, growth-guiding techniques. Currently, there is lack of data in this field. The objective of this study was, therefore, to compute segmental flexibility indices (standing angle minus corrected angle/standing angle). We compared segmental disc angles in 76 preoperative sets of standing and fulcrum-bending radiographs of thoracic curves (paired, two-tailed t tests, p < 0.05). The mean standing Cobb angle was 59.7 degrees (range 41.3 degrees -95 degrees ) and the flexibility index of the curve was 48.6% (range 16.6-78.8%). The disc angles showed symmetric periapical distribution with significant decrease (all p values <0.0001) for every cephalad (+) and caudad (-) level change. The periapical levels +1 and -1 wedged at 8.3 degrees and 8.7 degrees (range 3.5 degrees -14.8 degrees ), respectively. All angles were significantly smaller on the-bending views (p values <0.0001). We noted mean periapical flexibility indices of 46% (+1), 49% (-1), 57% (+2) and 81% (-2), which were significantly less (p < 0.001) than for the group of remote levels 105% (+3), 149% (-3), 231% (+4) and 300% (-4). The discal and bony wedging was 60 and 40%, respectively, and mean values 35 degrees and 24 degrees (p < 0.0001). Their relationship with the Cobb angle showed a moderate correlation (r = 0.56 and 0.45). Functional, radiographic analysis of idiopathic thoracic scoliosis revealed significant, homogenous segmental tethering confined to four periapical levels. Future research will aim at in vivo segmental measurements in three planes under defined load to provide in-depth data for novel therapeutic strategies.

  2. Selection of Fusion Levels Using the Fulcrum Bending Radiograph for the Management of Adolescent Idiopathic Scoliosis Patients with Alternate Level Pedicle Screw Strategy: Clinical Decision-making and Outcomes.

    Science.gov (United States)

    Samartzis, Dino; Leung, Yee; Shigematsu, Hideki; Natarajan, Deepa; Stokes, Oliver; Mak, Kin-Cheung; Yao, Guanfeng; Luk, Keith D K; Cheung, Kenneth M C

    2015-01-01

    Selecting fusion levels based on the Luk et al criteria for operative management of thoracic adolescent idiopathic scoliosis (AIS) with hook and hybrid systems yields acceptable curve correction and balance parameters; however, it is unknown whether utilizing a purely pedicle screw strategy is effective. Utilizing the fulcrum bending radiographic (FBR) to assess curve flexibility to select fusion levels, the following study assessed the efficacy of pedicle screw fixation with alternate level screw strategy (ALSS) for thoracic AIS. A retrospective study with prospective radiographic data collection/analyses (preoperative, postoperative 1-week and minimum 2-year follow-up) of 28 operative thoracic AIS patients undergoing ALSS was performed. Standing coronal/sagittal and FBR Cobb angles, FBR flexibility, fulcrum bending correction index (FBCI), trunkal shift, radiographic shoulder height (RSH), and list were assessed on x-rays. Fusion level selection was based on the Luk et al criteria and compared to conventional techniques. In the primary curve, the mean preoperative and postoperative 1 week and last follow-up standing coronal Cobb angles were 59.9, 17.2 and 20.0 degrees, respectively. Eighteen patients (64.3%) had distal levels saved (mean: 1.6 levels) in comparison to conventional techniques. Mean immediate and last follow-up FBCIs were 122.6% and 115.0%, respectively. Sagittal alignment did not statistically differ between any assessment intervals (p>0.05). A decrease in trunkal shift was noted from preoperative to last follow-up (p = 0.003). No statistically significant difference from preoperative to last follow-up was noted in RSH and list (p>0.05). No "add-on" of other vertebra or decompensation was noted and all patients achieved fusion. This is the first report to note that using the FBR for decision-making in selecting fusion levels in thoracic AIS patients undergoing management with pedicle screw constructs (e.g. ALSS) is a cost-effective strategy that

  3. Selection of Fusion Levels Using the Fulcrum Bending Radiograph for the Management of Adolescent Idiopathic Scoliosis Patients with Alternate Level Pedicle Screw Strategy: Clinical Decision-making and Outcomes.

    Directory of Open Access Journals (Sweden)

    Dino Samartzis

    Full Text Available Selecting fusion levels based on the Luk et al criteria for operative management of thoracic adolescent idiopathic scoliosis (AIS with hook and hybrid systems yields acceptable curve correction and balance parameters; however, it is unknown whether utilizing a purely pedicle screw strategy is effective. Utilizing the fulcrum bending radiographic (FBR to assess curve flexibility to select fusion levels, the following study assessed the efficacy of pedicle screw fixation with alternate level screw strategy (ALSS for thoracic AIS.A retrospective study with prospective radiographic data collection/analyses (preoperative, postoperative 1-week and minimum 2-year follow-up of 28 operative thoracic AIS patients undergoing ALSS was performed. Standing coronal/sagittal and FBR Cobb angles, FBR flexibility, fulcrum bending correction index (FBCI, trunkal shift, radiographic shoulder height (RSH, and list were assessed on x-rays. Fusion level selection was based on the Luk et al criteria and compared to conventional techniques.In the primary curve, the mean preoperative and postoperative 1 week and last follow-up standing coronal Cobb angles were 59.9, 17.2 and 20.0 degrees, respectively. Eighteen patients (64.3% had distal levels saved (mean: 1.6 levels in comparison to conventional techniques. Mean immediate and last follow-up FBCIs were 122.6% and 115.0%, respectively. Sagittal alignment did not statistically differ between any assessment intervals (p>0.05. A decrease in trunkal shift was noted from preoperative to last follow-up (p = 0.003. No statistically significant difference from preoperative to last follow-up was noted in RSH and list (p>0.05. No "add-on" of other vertebra or decompensation was noted and all patients achieved fusion.This is the first report to note that using the FBR for decision-making in selecting fusion levels in thoracic AIS patients undergoing management with pedicle screw constructs (e.g. ALSS is a cost-effective strategy

  4. Fulcrum Network Codes

    DEFF Research Database (Denmark)

    2015-01-01

    Fulcrum network codes, which are a network coding framework, achieve three objectives: (i) to reduce the overhead per coded packet to almost 1 bit per source packet; (ii) to operate the network using only low field size operations at intermediate nodes, dramatically reducing complexity in the net...... the number of dimensions seen by the network using a linear mapping. Receivers can tradeoff computational effort with network delay, decoding in the high field size, the low field size, or a combination thereof.......Fulcrum network codes, which are a network coding framework, achieve three objectives: (i) to reduce the overhead per coded packet to almost 1 bit per source packet; (ii) to operate the network using only low field size operations at intermediate nodes, dramatically reducing complexity...... in the network; and (iii) to deliver an end-to-end performance that is close to that of a high field size network coding system for high-end receivers while simultaneously catering to low-end ones that can only decode in a lower field size. Sources may encode using a high field size expansion to increase...

  5. Fulcrum Network Codes

    DEFF Research Database (Denmark)

    2015-01-01

    Fulcrum network codes, which are a network coding framework, achieve three objectives: (i) to reduce the overhead per coded packet to almost 1 bit per source packet; (ii) to operate the network using only low field size operations at intermediate nodes, dramatically reducing complexity...... in the network; and (iii) to deliver an end-to-end performance that is close to that of a high field size network coding system for high-end receivers while simultaneously catering to low-end ones that can only decode in a lower field size. Sources may encode using a high field size expansion to increase...... the number of dimensions seen by the network using a linear mapping. Receivers can tradeoff computational effort with network delay, decoding in the high field size, the low field size, or a combination thereof....

  6. FULCRUM - A dam safety management and alert system

    Energy Technology Data Exchange (ETDEWEB)

    Butt, Cameron; Greenaway, Graham [Knight Piesold Ltd., Vancouver, (Canada)

    2010-07-01

    Efficient management of instrumentation, monitoring and inspection data are the keys to safe performance and dam structure stability. This paper presented a data management system, FULCRUM, developed for dam safety management. FULCRUM is a secure web-based data management system which simplifies the process of data collection, processing and analysis of the information. The system was designed to organize and coordinate dam safety management requirements. Geotechnical instrumentation such as piezometers or inclinometers and operating data can be added to the database. Data from routine surveillance and engineering inspection can also be incorporated into the database. The system provides users with immediate access to historical and recent data. The integration of a GIS system allows for rapid assessment of the project site. Customisable alerting protocols can be set to identify and respond quickly to significant changes in operating conditions and potential impacts on dam safety.

  7. Coping with the Upcoming Heterogeneity in 5G Communications and Storage Using Fulcrum Network Codes

    DEFF Research Database (Denmark)

    Roetter, Daniel Enrique Lucani; Pedersen, Morten Videbæk; Heide, Janus

    2014-01-01

    In this paper, Fulcrum network codes are introduced as a viable solution to cope with the heterogeneity of 5G communication and storage systems. Fulcrum network codes are an enhancement of random linear network codes (RLNC) offering high throughput performance at low overhead. This contrasts...

  8. Correction of post-traumatic kyphosis using intermediate facet joints as fulcrum in dorso-lumbar spine injuries

    Directory of Open Access Journals (Sweden)

    Agrawal Amit

    2006-01-01

    Full Text Available Background : Post traumatic kyphotic deformity are managed by different methods. Posterior stabilization of dorso-lumbar fractures with transpedicular screws and rods using intermediate facets as fulcrum can restore body height. Methods and material : In a retrospective clinical study 6 consecutive patients with complete or incomplete neurological deficits as a result of the dorso-lumbar fractures were included. Local kyphosis was measured as the angle between the upper and lower end plates of the collapsed vertebrae preoperatively, postoperatively and at the last follow-up visit. The neurological condition of the patients was recorded in the pre-op and follow up period according to Frankel grading systems. Stabilization with pedicle screw fixation and posterior fusion with autogenous bone chips were done after decompression in all 6 patients included in this study. The outcome of the study was evaluated with regard to the correction of kyphotic deformity and increase in vertebral body height after adequate neural canal decompression and fusion. Results : Of the 6 patients 4 were Frankel A and 2 Frankel C pre-operatively. Three patients sustained wedge fracture and three sustained burst fracture. The most commonly affected vertebra was L 1 with 4 cases followed by L 2 . The preoperative mean kyphotic angle was 23.3° (17°-28°, and was corrected to 15.8 (12° - 22° with a correction rate of 32.3% (21.4 - 43.5 % in the post-operative period and this correction was improved at three months follow up and the final correction was measured to be 46.3% (22.7-59.0 %. Serial postoperative radiographic follow-up assessment showed maintenance of kyphotic correction. Minimum correction of body height was .05 cm (correction rate-1.8% and maximum correction was .65 cm (correction rate-28.9% in post-operative period with a mean of 0.29 cm (correction rate-13.1%. Conclusions : Preserved the intermediate articular processes can be used as fulcrum to reduce

  9. Standardization of dynamic RX for preoperative planning in adolescent idiopathic scoliosis

    Directory of Open Access Journals (Sweden)

    Everton Quadros Fiebig

    2014-09-01

    Full Text Available OBJECTIVE: To compare X-rays usually performed in supine with lateralization with those in lateral decubitus with fulcrum at the apex of the primary curve caused by cushion, in order to monitor the achievement of improvement patterns of correction in preestablished deformities for the preoperative surgical planning. METHODS: Comparison of radiographic studies in the preoperative supine with lateralization and lateral decubitus with cushion performing fulcrum at the apex of the major curve in patients with adolescent idiopathic scoliosis. RESULTS: Curves varied in AP between 76° e 40° and were corrected in supine with lateralization to the average of 21° observing that when carried out with fulcrum with cushion in lateral decubitus the curves were corrected to 15° on average with higher discrepancy in values among the most rigid curves. CONCLUSIONS: It was verified that on flexible curves the cushions did not produce satisfactory corrections in primary curves. In more rigid curves and in collaborative patients, greater effectiveness on the correction of deformity in main curves was obtained with cushions producing local fulcrum for a better preoperative planning on correction of deformities.

  10. Defining the neural fulcrum for chronic vagus nerve stimulation: implications for integrated cardiac control.

    Science.gov (United States)

    Ardell, Jeffrey L; Nier, Heath; Hammer, Matthew; Southerland, E Marie; Ardell, Christopher L; Beaumont, Eric; KenKnight, Bruce H; Armour, J Andrew

    2017-09-01

    The evoked cardiac response to bipolar cervical vagus nerve stimulation (VNS) reflects a dynamic interaction between afferent mediated decreases in central parasympathetic drive and suppressive effects evoked by direct stimulation of parasympathetic efferent axons to the heart. The neural fulcrum is defined as the operating point, based on frequency-amplitude-pulse width, where a null heart rate response is reproducibly evoked during the on-phase of VNS. Cardiac control, based on the principal of the neural fulcrum, can be elicited from either vagus. Beta-receptor blockade does not alter the tachycardia phase to low intensity VNS, but can increase the bradycardia to higher intensity VNS. While muscarinic cholinergic blockade prevented the VNS-induced bradycardia, clinically relevant doses of ACE inhibitors, beta-blockade and the funny channel blocker ivabradine did not alter the VNS chronotropic response. While there are qualitative differences in VNS heart control between awake and anaesthetized states, the physiological expression of the neural fulcrum is maintained. Vagus nerve stimulation (VNS) is an emerging therapy for treatment of chronic heart failure and remains a standard of therapy in patients with treatment-resistant epilepsy. The objective of this work was to characterize heart rate (HR) responses (HRRs) during the active phase of chronic VNS over a wide range of stimulation parameters in order to define optimal protocols for bidirectional bioelectronic control of the heart. In normal canines, bipolar electrodes were chronically implanted on the cervical vagosympathetic trunk bilaterally with anode cephalad to cathode (n = 8, 'cardiac' configuration) or with electrode positions reversed (n = 8, 'epilepsy' configuration). In awake state, HRRs were determined for each combination of pulse frequency (2-20 Hz), intensity (0-3.5 mA) and pulse widths (130-750 μs) over 14 months. At low intensities and higher frequency VNS, HR increased during the

  11. Nuss procedure: Technical modifications to ease bending of the support bar and lateral stabilizer placement

    Directory of Open Access Journals (Sweden)

    Osman Zeki Karakus

    2016-01-01

    Conclusion: Preoperative bending of the support bar according to anthropometric measurements and fixation of the lateral stabilizers to the support bar in inverted position facilitates bar shaping and lateral stabilizer placement.

  12. Bend me, shape me

    CERN Multimedia

    2002-01-01

    A Japanese team has found a way to bend and shape silicon substrates by growing a thin layer of diamond on top. The technique has been proposed as an alternative to mechanical bending, which is currently used to make reflective lenses for X-ray systems and particle physics systems (2 paragraphs).

  13. Occipital bending in schizophrenia.

    Science.gov (United States)

    Maller, Jerome J; Anderson, Rodney J; Thomson, Richard H; Daskalakis, Zafiris J; Rosenfeld, Jeffrey V; Fitzgerald, Paul B

    2017-01-01

    To investigate the prevalence of occipital bending (an occipital lobe crossing or twisting across the midline) in subjects with schizophrenia and matched healthy controls. Occipital bending prevalence was investigated in 37 patients with schizophrenia and 44 healthy controls. Ratings showed that prevalence was nearly three times higher among schizophrenia patients (13/37 [35.1%]) than in control subjects (6/44 [13.6%]). Furthermore, those with schizophrenia had greater normalized gray matter volume but less white matter volume and had larger brain-to-cranial ratio. The results suggest that occipital bending is more prevalent among schizophrenia patients than healthy subjects and that schizophrenia patients have different gray matter-white matter proportions. Although the cause and clinical ramifications of occipital bending are unclear, the results infer that occipital bending may be a marker of psychiatric illness.

  14. LEAR bending magnet quadrant

    CERN Multimedia

    CERN PhotoLab

    1981-01-01

    During 1981, the PS South-Hall, no longer used for physics experiments, was cleared for the installation of the Low Energy Antiproton Ring, LEAR. In October 1981, 3 of the 4 bending magnet quadrants were in place, this is one of them.

  15. DNA Bending elasticity

    Science.gov (United States)

    Sivak, David Alexander

    DNA bending elasticity on length scales of tens of basepairs is of critical importance in numerous biological contexts. Even the simplest models of DNA bending admit of few simple analytic results, thus there is a need for numerical methods to calculate experimental observables, such as distance distributions, forces, FRET efficiencies, and timescales of particular large-scale motions. We have implemented and helped develop a coarse-grained representation of DNA and various other covalently-linked groups that allows simple calculation of such observables for varied experimental systems. The simple freely-jointed chain (FJC) model and extremely coarse resolution proved useful in understanding DNA threading through nanopores, identifying steric occlusion by other parts of the chain as a prime culprit for slower capture as distance to the pore decreased. Enhanced sampling techniques of a finer resolution discrete wormlike chain (WLC) model permitted calculation of cyclization rates for small chains and identified the ramifications of a thermodynamically-sound treatment of thermal melts. Adding treatment of double-stranded DNA's helical nature and single-stranded DNA provided a model system that helped demonstrate the importance of statistical fluctuations in even highly-stressed DNA mini-loops, and allowed us to verify that even these constructs show no evidence of excitation-induced softening. Additional incorporation of salt-sensitivity to the model allowed us to calculate forces and FRET efficiencies for such mini-loops and their uncircularized precursors, thereby furthering the understanding of the nature of IHF binding and bending of its recognition sequence. Adding large volume-excluding spheres linked to the ends of the dsDNA permits calculation of distance distributions and thus small-angle X-ray scattering, whereby we demonstrated the validity of the WLC in describing bending fluctuations in DNA chains as short as 42 bp. We also make important connections

  16. A multipurpose tissue bending machine.

    Science.gov (United States)

    Vesely, I; Boughner, D R

    1985-01-01

    A unique tissue bending machine was developed to test the bending properties of normal and bioprosthetic heart valve material. It can be operated in air or in a tissue bath and can measure bending torques with an accuracy in excess of 1.0 microN m. Three contrasting substances were tested to compare their stiffness and to demonstrate the machine.

  17. Preoperative preparation of children

    Directory of Open Access Journals (Sweden)

    Priya Reshma Aranha

    2017-01-01

    Full Text Available Surgery is a stressful and anxiety provoking experience for children. Millions of children undergo surgery every year. The majority of children experience significant preoperative anxiety which intern can affect their recovery. Preoperative anxiety may bring about physical and physiological changes in children, which can be particularly evident in terms of increased heart rate and blood pressure. To identify various strategies used to minimize the preoperative anxiety of children and update their clinical effectiveness among children undergoing surgery, the authors searched PubMed, MEDLINE, CINAHL, ScienceDirect, Google Scholar, Scopus, and Cochrane Library for identifying the relevant studies and retrieved available literature. It is concluded that utilization of the strategies available to reduce the preoperative anxiety of children will be a promising intervention to reduce anxiety, to promote relaxation, satisfaction, and speedy recovery. Many of these techniques are simple, cost-effective and can be easily carried out by nurses. It is essential to use the age appropriate and individualized methods in preparing children for surgery. Further research is required to strengthen the evidence.

  18. Interventions for preoperative smoking cessation

    DEFF Research Database (Denmark)

    Møller, A; Villebro, N

    2005-01-01

    Smokers have a substantially increased risk of intra- and postoperative complications. Preoperative smoking intervention may be effective in decreasing this incidence. The preoperative period may be a well chosen time to offer smoking cessation interventions due to increased patient motivation....

  19. Pre-operative anaemia.

    Science.gov (United States)

    Clevenger, B; Richards, T

    2015-01-01

    Pre-operative anaemia is a relatively common finding, affecting a third of patients undergoing elective surgery. Traditionally associated with chronic disease, management has historically focused on the use of blood transfusion as a solution for anaemia in the peri-operative period. Data from large series now suggest that anaemia is an independent risk associated with poor outcome in both cardiac and non-cardiac surgery. Furthermore, blood transfusion does not appear to ameliorate this risk, and in fact may increase the risk of postoperative complications and hospital length of stay. Consequently, there is a need to identify, diagnose and manage pre-operative anaemia to reduce surgical risk. Discoveries in the pathways of iron metabolism have found that chronic disease can cause a state of functional iron deficiency leading to anaemia. The key iron regulatory protein hepcidin, activated in response to inflammation, inhibits absorption of iron from the gastrointestinal tract and further reduces bioavailability of iron stores for red cell production. Consequently, although iron stores (predominantly ferritin) may be normal, the transport of iron either from the gastrointestinal tract or iron stores to the bone marrow is inhibited, leading to a state of 'functional' iron deficiency and subsequent anaemia. Since absorption from the gastrointestinal tract is blocked, increasing oral iron intake is ineffective, and studies are now looking at the role of intravenous iron to treat anaemia in the surgical setting. In this article, we review the incidence and impact of anaemia on the pre-operative patient. We explain how anaemia may be caused by functional iron deficiency, and how iron deficiency anaemia may be diagnosed and treated.

  20. Sheet Bending using Soft Tools

    Science.gov (United States)

    Sinke, J.

    2011-05-01

    Sheet bending is usually performed by air bending and V-die bending processes. Both processes apply rigid tools. These solid tools facilitate the generation of software for the numerical control of those processes. When the lower rigid die is replaced with a soft or rubber tool, the numerical control becomes much more difficult, since the soft tool deforms too. Compared to other bending processes the rubber backed bending process has some distinct advantages, like large radius-to-thickness ratios, applicability to materials with topcoats, well defined radii, and the feasibility of forming details (ridges, beads). These advantages may give the process exclusive benefits over conventional bending processes, not only for industries related to mechanical engineering and sheet metal forming, but also for other disciplines like Architecture and Industrial Design The largest disadvantage is that also the soft (rubber) tool deforms. Although the tool deformation is elastic and recovers after each process cycle, the applied force during bending is related to the deformation of the metal sheet and the deformation of the rubber. The deformation of the rubber interacts with the process but also with sheet parameters. This makes the numerical control of the process much more complicated. This paper presents a model for the bending of sheet materials using a rubber lower die. This model can be implemented in software in order to control the bending process numerically. The model itself is based on numerical and experimental research. In this research a number of variables related to the tooling and the material have been evaluated. The numerical part of the research was used to investigate the influence of the features of the soft lower tool, like the hardness and dimensions, and the influence of the sheet thickness, which also interacts with the soft tool deformation. The experimental research was focused on the relation between the machine control parameters and the most

  1. Preoperative anxiety in neurosurgical patients.

    Science.gov (United States)

    Perks, Anna; Chakravarti, Sucharita; Manninen, Pirjo

    2009-04-01

    Anxiety is common in surgical patients, with an incidence of 60% to 92%. There is little information on the incidence and severity of preoperative anxiety in patients scheduled for neurosurgery. The aim of this study was to measure the level of preoperative anxiety in neurosurgical patients and to assess any influencing factors. After the Institutional Review Board approval and informed written consent, 100 patients booked for neurosurgery were interviewed preoperatively. Each patient was asked to grade their preoperative anxiety level on a verbal analog scale, Amsterdam Preoperative Anxiety and Information Scale, and a set of specific anxiety-related questions. The anxiety scores and the responses to the questions were compared between the sex, age, weight, diagnosis, and history of previous surgery. The mean age (+/-SD) was 50+/-13 years. The preoperative diagnosis was tumor (n=64), aneurysm (n=14), and other (n=22). Overall verbal analog scale was 5.2+/-2.7; the score was higher for female (5.8+/-2.8) than male patients (4.6+/-2.5) (PAmsterdam Preoperative Anxiety and Information Scale anxiety and knowledge scores were greater for surgery than for anesthesia. Questionnaire results showed that the most common anxieties were waiting for surgery, physical/mental harm, and results of the operation. In conclusion, our study showed that neurosurgical patients have high levels of anxiety, with a higher incidence in females. There was a moderately high need for information, particularly in patients with a high level of preoperative anxiety.

  2. A Numerical Study of the Spring-Back Phenomenon in Bending with a Rebar Bending Machine

    OpenAIRE

    Chang Hwan Choi; Lawrence Kulinsky; Joon Soo Jun; Jin Ho Kim

    2014-01-01

    Recently, the rebar bending methodology started to change from field processing to utilizing rebar bending machines at plant sites prior to transport to the construction locations. Computerized control of rebar plant bending machines provides more accurate and faster bending of rebars than the low quality inefficient field processing alternative. The bending process involves plastic deformation of rebars, where bending stress beyond the yield point of the material is applied. When the bending...

  3. Surgical treatment for scoliosis extending to main thoracic spine by key-vertebral-screws technique (KVST)

    Institute of Scientific and Technical Information of China (English)

    LI Ming; ZHU Xiao-dong; Cheung KM; Luk KD

    2007-01-01

    Objective:To introduce a key-vertebral-screws technique(KVST) in the surgical treatment of scoliosis extending to main thoracic levels,and to find the role of fulcrum bending in predicting the result of surgical treatment for scoliosis by this technique.Methods:Seventeen consecutive patients with scoliosis extending to main thoracic spine,who underwent pure posterior fusion without anterior or posterior release by KVST between January 2004 and July 2005 were evaluated for fulcrum bending flexibility,surgical correction rate,fulcrum bending correction index (FBCI) in main thoracic curves.Universal Spine System (USS) instrumentation was used in 15 cases,Monarch in another 2 cases.The severity of the curves was measured by Cobb's method using RadWork 6.0 software.Preoperative standing AP radiographs,preoperative fulcrum bending anterioposterior (AP) radiographs,postoperative standing AP radiographs,and most recent follow-up standing AP radiographs for spine were measured and recorded.All the data were analyzed with two-sample paired t-test by Origin 7.0 software.Results:Infection and neurological complications were not noted.No major complications were found.Just one case had some axial back pain,which got a full recovery from physiotherapy for 2 weeks.In the X-ray,there was an average correction of 71.5% of the fused main thoracic curves,which had no significant lose of correction in final follow-up.For the whole fused main thoracic curves,the fulcrum bending flexibility were lower to operation correction rate (P=0.013).The average FBCI was 123%.From the data,the more rigid curves (especially fulcrum bending flexibility<50%),the more correction rate operation could get,compared with fulcrum bending flexibility.Conclusion:(1) KVST is a good method in the surgical treatment of thoracic scoliosis,which can get satisfying result with lower medical cost.(2) Fulcrum bending flexibility is lower than operative correction rate by KVST in main thoracic curves (P<0.05).In

  4. Bending fracture in carbon nanotubes.

    Science.gov (United States)

    Kuo, Wen-Shyong; Lu, Hsin-Fang

    2008-12-10

    A novel approach was adopted to incur bending fracture in carbon nanotubes (CNTs). Expanded graphite (EG) was made by intercalating and exfoliating natural graphite flakes. The EG was deposited with nickel particles, from which CNTs were grown by chemical vapor deposition. The CNTs were tip-grown, and their roots were fixed on the EG flakes. The EG flakes were compressed, and many CNTs on the surface were fragmented due to the compression-induced bending. Two major modes of the bending fracture were observed: cone-shaped and shear-cut. High-resolution scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine the crack growth within the graphene layers. The bending fracture is characterized by two-region crack growth. An opening crack first appears around the outer-tube due to the bending-induced tensile stress. The crack then branches to grow along an inclined direction toward the inner-tube due to the presence of the shear stress in between graphene layers. An inner-tube pullout with inclined side surface is formed. The onset and development of the crack in these two regions are discussed.

  5. Tube bending on the roll machine

    Science.gov (United States)

    Nepershin, Rostislav I.

    2013-10-01

    Computer simulation of the elastic-plastic tube bending by pushing on three-roll machine with work hardening effect consideration is presented. Non-steady tube bending process for specified curvature is simulated with axis of bending roll displacement, followed by transfer to the steady-state bending process. Estimation of curvature, constrained by tube section elliptical distortion modeled by plastic hinge mechanism is given. Elastic-plastic bending moment versus curvature and critical curvature estimation reasonably correlated with experiments.

  6. A New Kind of Bend Sensor

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new kind of bend sensor is introduced.It can be used to detect the bend angle of an object or inclination between two objects.It has characteristics of small size, lightweight, high reliability, fine flexibility and plasticity.When this bend sensor is used with a proper converting circuit, it can implement dynamic measuring the bend angle of an object conveniently.The application of the bend sensor in dataglove is also described.

  7. Design of an impedance matching acoustic bend

    OpenAIRE

    Yang, Yuzhen; Jia, Han; Lu, Wenjia; Sun, Zhaoyong; Yang, Jun

    2017-01-01

    We propose the design of an impedance matching acoustic bend in this article. The bending structure is composed of sub-wavelength unit cells with perforated plates and side pipes, whose mass density and bulk modulus can be tuned simultaneously. So the refraction index and the impedance of the acoustic bend can be modulated simultaneously to guarantee both the bending effect and the high transmission. The simulation results of sound pressure field distribution show that the bending effect of t...

  8. Bending characteristics of resin concretes

    Directory of Open Access Journals (Sweden)

    Ribeiro Maria Cristina Santos

    2003-01-01

    Full Text Available In this research work the influence of composition and curing conditions in bending strength of polyester and epoxy concrete is analyzed. Various mixtures of resin and aggregates were considered in view of an optimal combination. The Taguchi methodology was applied in order to reduce the number of tests, and in order to evaluate the influence of various parameters in concrete properties. This methodology is very useful for the planning of experiments. Test results, analyzed by this methodology, shown that the most significant factors affecting bending strength properties of resin concretes are the type of resin, resin content and charge content. An optimal formulation leading to a maximum bending strength was achieved in terms of material parameters.

  9. 预置支点介导下的上颌近远中阻生尖牙的矫治%Clinical application of artificial fulcrum in the treatment of horizontally impacted upper canine

    Institute of Scientific and Technical Information of China (English)

    彭友俭; 程祥荣; 东耀峻; 武广增; 敖妮娜; 马霄

    2010-01-01

    Objective To explore the treatment of horizontally impacted maxillary canines with artificial fulcrum. Methods Five patients with horizontally impacted maxillary canines were involved. The space was regained by using straight wire appliance. After surgical exposure, artificial fulcrums were placed on dental cervix of the impacted canines and traction was applied to these impacted canines. Panoramic x-ray was used to evaluate the roots resorption. Results Impacted maxillary canines of the 5 patients were corrected to normal position. The tooth pulp and periodontal tissue were healthy. There was no root resorption of adjacent teeth. Conclusions The artificial fulcrum changed the center of rotation in the treatment of horizontally impacted upper canine.%目的 探讨预置支点在矫治上颌水平阻生尖牙的作用.方法 水平埋伏阻生上颌尖牙5例,均位于邻牙根方.用直丝弓矫治器进行间隙预备,外科开窗暴露埋伏尖牙的牙冠,将预置支点置于牙颈部,进行正畸牵引,曲面断层片观察邻牙牙根吸收情况.结果 水平阻生尖牙以预置支点为转动中心而移动至正常位置,牙髓和牙周情况良好,邻牙牙根无吸收现象.结论 预置支点水平阻生上颌尖牙的转动中心,对正畸临床治疗有指导意义.

  10. Preoperative alcoholism and postoperative morbidity

    DEFF Research Database (Denmark)

    Tonnesen, H; Kehlet, H

    1999-01-01

    BACKGROUND: Preoperative risk assessment has become part of daily clinical practice, but preoperative alcohol abuse has not received much attention. METHODS: A Medline search was carried out to identify original papers published from 1967 to 1998. Relevant articles on postoperative morbidity...... in alcohol abusers were used to evaluate the evidence. RESULTS: Prospective and retrospective studies demonstrate a twofold to threefold increase in postoperative morbidity in alcohol abusers, the most frequent complications being infections, bleeding and cardiopulmonary insufficiency. Wound complications...... to postoperative morbidity. CONCLUSION: Alcohol consumption should be included in the preoperative assessment of likely postoperative outcome. Reduction of postoperative morbidity in alcohol abusers may include preoperative alcohol abstinence to improve organ function, or perioperative alcohol administration...

  11. Bending behavior of lapped plastic ehv cables

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, G H; Muller, A C

    1980-01-01

    One of the factors delaying the development of lapped polymeric cables has been their reputed poor bending characteristics. Complementary programs were begun at BNL several years ago to mathematically model the bending of synthetic tape cables and to develop novel plastic tapes designed to have moduli more favorable to bending. A series of bend tests was recently completed to evaluate the bending performance of several tapes developed for use in experimental superconducting cables. The program is discussed and the results of the bend tests are summarized.

  12. Hormonal regulation of gravitropic bending

    Science.gov (United States)

    Hu, X.; Cui, D.; Xu, X.; Hu, L.; Cai, W.

    Gravitropic bending is an important subject in the research of plant Recent data support the basics of the Cholodny-Went hypothesis indicating that differential growth in gravitropism is due to redistribution of auxin to the lower sides of gravistimulated roots but little is known regarding the molecular details of such effects So we carried a series of work surround the signals induced by auxin end center We found the endogenous signaling molecules nitric oxide NO and cGMP mediate responses to gravistimulation in primary roots of soybean Glycine max Horizontal orientation of soybean roots caused the accumulation of both NO and cGMP in the primary root tip Fluorescence confocal microcopy revealed that the accumulation of NO was asymmetric with NO concentrating in the lower side of the root Auxin induced NO accumulation in root protoplasts and asymmetric NO accumulation in root tips Gravistimulation NO and auxin also induced the accumulation of cGMP a response inhibited by removal of NO or by inhibitors of guanylyl cyclase compounds that also reduced gravitropic bending Asymmetric NO accumulation and gravitropic bending were both inhibited by an auxin transport inhibitor and the inhibition of bending was overcome by treatment with NO or 8-bromo-cGMP a cell-permeable analog of cGMP These data indicate that auxin-induced NO and cGMP mediate gravitropic curvature in soybean roots From Hu et al Plant Physiol 2005 137 663-670 The asymmetric distribution of auxin plays a fundamental role in plant gravitropic bending

  13. FFAG lattice without opposite bends

    Science.gov (United States)

    Trbojevic, Dejan; Courant, Ernest D.; Garren, Al

    2000-08-01

    A future "neutrino factory" or Muon Collider requires fast muon acceleration before the storage ring. Several alternatives for fast muon acceleration have previously been considered. One of them is the FFAG (Fixed Field Alternating Gradient) synchrotron. The FFAG concept was developed in 1952 by K. R. Symon (ref. 1). The advantages of this design are the fixed magnetic field, large range of particle energy, simple RF; power supplies are simple, and there is no transition energy. But a drawback is that reverse bending magnets are included in the configuration; this increases the size and cost of the ring. Recently some modified FFAG lattice designs have been described where the amount of opposite bending was significantly reduced (ref. 2, ref. 3).

  14. FFAG lattice without opposite bends

    CERN Document Server

    Trbojevic, D; Garren, A

    2000-01-01

    A future 'neutrino factory' or Muon Collider requires fast muon acceleration before the storage ring. Several alternatives for fast muon acceleration have previously been considered. One of them is the FFAG (Fixed Field Alternating Gradient) synchrotron. The FFAG concept was developed in 1952 by K. R. Symon (ref. 1). The advantages of this design are the fixed magnetic field, large range of particle energy, simple RF; power supplies are simple, and there is no transition energy. But a drawback is that reverse bending magnets are included in the configuration; this increases the size and cost of the ring. Recently some modified FFAG lattice designs have been described where the amount of opposite bending was significantly reduced (ref. 2, ref. 3).

  15. Interventions for preoperative smoking cessation

    DEFF Research Database (Denmark)

    Thomsen, Thordis; Villebro, Nete; Møller, Ann Merete

    2014-01-01

    : Randomized controlled trials that recruited people who smoked prior to surgery, offered a smoking cessation intervention, and measured preoperative and long-term abstinence from smoking or the incidence of postoperative complications or both outcomes. DATA COLLECTION AND ANALYSIS: The review authors......BACKGROUND: Smokers have a substantially increased risk of postoperative complications. Preoperative smoking intervention may be effective in decreasing this incidence, and surgery may constitute a unique opportunity for smoking cessation interventions. OBJECTIVES: The objectives of this review...... are to assess the effect of preoperative smoking intervention on smoking cessation at the time of surgery and 12 months postoperatively, and on the incidence of postoperative complications. SEARCH METHODS: We searched the Cochrane Tobacco Addiction Group Specialized Register in January 2014. SELECTION CRITERIA...

  16. Preoperative staging of rectal cancer.

    Science.gov (United States)

    Smith, Neil; Brown, Gina

    2008-01-01

    Detailed preoperative staging using high resolution magnetic resonance imaging (MRI) enables the selection of patients that require preoperative therapy for tumour regression. This information can be used to instigate neoadjuvant therapy in those patients with poor prognostic features prior to disturbing the tumour bed and potentially disseminating disease. The design of trials incorporating MR assessment of prognostic factors prior to therapy has been found to be of value in assessing treatment modalities and outcomes that are targeted to these preoperative prognostic subgroups and in providing a quantifiable assessment of the efficacy of particular chemoradiation treatment protocols by comparing pre-treatment MR staging with post therapy histology assessment. At present, we are focused on achieving clear surgical margins of excision (CRM) to avoid local recurrence. We recommend that all patients with rectal cancer should undergo pre-operative MRI staging. Of these, about half will have good prognosis features (T1-T3b, N0, EMVI negative, CRM clear) and may safely undergo primary total mesorectal excision. Of the remainder, those with threatened or involved margins will certainly benefit from pre-operative chemoradiotherapy with the aim of downstaging to permit safe surgical excision. In the future, our ability to recognise features predicting distant failure, such as extramural vascular invasion (EMVI) may be used to stratify patients for neo-adjuvant systemic chemotherapy in an effort to prevent distant relapse. The optimal pre-operative treatment regimes for these patients (radiotherapy alone, systemic chemotherapy alone or combination chemo-radiotherapy) is the subject of current and future trials.

  17. Anxiety in preoperative anesthetic procedures.

    Science.gov (United States)

    Valenzuela Millán, Jaquelyn; Barrera Serrano, José René; Ornelas Aguirre, José Manuel

    2010-01-01

    Preoperative anxiety is a common and poorly evaluated condition in patients who will undergo an anesthetic and surgical intervention. The objective of this study was to determine the prevalence of anxiety in a group of patients undergoing elective surgery, as assessed by the Amsterdam Anxiety Preoperative and Information (AAPI) scale. We studied 135 patients scheduled for elective surgery applying the AAPI scale 24 h before the surgical procedure to evaluate the presence of anxiety and patient characteristics. A descriptive analysis with mean +/- standard deviation for categorical variables was done. For intragroup differences, chi(2) test was used. Pearson correlation for the association between anxiety and postoperative complications was carried out. A value of p =0.05 was considered significant. One hundred six patients were surgically treated, 88% were female (average age 44 +/- 12 years). Some degree of preoperative anxiety was present in 72 patients (76%; p = 0.001) with a grade point average on the AAPI scale equal to 17 +/- 7 points, of which 95 (70%, OR = 5.08; p = 0.002) were females. Results of this study suggest the presence of high levels of preoperative anxiety in patients scheduled for elective surgery. The origin of the anxiety appears to be related to many factors that can be evaluated in pre-anesthetic consultation. Further study is needed to prevent the presence of this disorder.

  18. Bending and stretching of plates

    CERN Document Server

    Mansfield, E H; Hemp, W S

    1964-01-01

    The Bending and Stretching of Plates deals with elastic plate theory, particularly on small- and large-deflexion theory. Small-deflexion theory concerns derivation of basic equations, rectangular plates, plates of various shapes, plates whose boundaries are amenable to conformal transformation, plates with variable rigidity, and approximate methods. Large-deflexion theory includes general equations and some exact solutions, approximate methods in large-deflexion theory, asymptotic large-deflexion theories for very thin plates. Asymptotic theories covers membrane theory, tension field theory, a

  19. Particle deposition in industrial duct bends.

    Science.gov (United States)

    Peters, Thomas M; Leith, David

    2004-07-01

    A study of particle deposition in industrial duct bends is presented. Particle deposition by size was measured by comparing particle size distributions upstream and downstream of bends that had geometries and flow conditions similar to those used in industrial ventilation. As the interior surface of the duct bend was greased to prevent particle bounce, the results are applicable to liquid drops and solid particles where duct walls are sticky. Factors investigated were: (i) flow Reynolds number (Re = 203 000, 36 000); (ii) particle Reynolds number (10 vertical); and (vii) construction technique (smooth, gored, segmented). Measured deposition was compared with models developed for bends in small diameter sampling lines (Re 20 microm, deposition was slightly greater in the horizontal-to-horizontal orientation than in the horizontal-to-vertical orientation due to gravitational settling. Penetration was not a multiplicative function of bend angle as theory predicts, due to the developing nature of turbulent flow in bends. Deposition in a smooth bend was similar to that in a gored bend; however, a tight radius segmented bend (R0 = 1.7) exhibited much lower deposition. For more gradual bends (3 < R0 < 12), curvature ratio had negligible effect on deposition.

  20. Garment-Integrated Bend Sensor

    Directory of Open Access Journals (Sweden)

    Guido Gioberto

    2014-09-01

    Full Text Available Garment-integrated sensors equip clothes with a smart sensing capability, while preserving the comfort of the user. However, this benefit can be to the detriment of sensing accuracy due to the unpredictability of garment movement (which affects sensor positioning and textile folds (which can affect sensor orientation. However, sensors integrated directly into garments or fabric structures can also be used to detect the movement of the garment during wearing. Specifically, a textile bend sensor could be used to sense folds in the garment. We tested a garment-integrated stitched sensor for five types of folds, stitched on five different weights of un-stretchable denim fabric and analyzed the effects of fold complexity and fabric stiffness, under un-insulated and insulated conditions. Results show that insulation improves the linearity and repeatability of the sensor response, particularly for higher fold complexity. Stiffer fabrics show greater sensitivity, but less linearity. Sensor response amplitude is larger for more complex fold geometries. The utility of a linear bending response (insulated and a binary shorting response (un-insulated is discussed. Overall, the sensor exhibits excellent repeatability and accuracy, particularly for a fiber-based, textile-integrated sensor.

  1. FACTORS INFLUENCING BENDING RIGIDITY OF SUBMERGED VEGETATION

    Institute of Scientific and Technical Information of China (English)

    WU Long-hua; YANG Xiao-li

    2011-01-01

    The bending rigidity of submerged vegetation is closely related with vegetative drag force.This work aims at determining the effects of flow conditions and characteristics of vegetation on the bending rigidity of submerged vegetation.Based on the dimensional analysis method,the factors influencing the bending rigidity of individual submerged vegetation were analyzed.The relationship between the relative bending rigidity and its influencing factors was investigated by experimental observation,and a relative bending rigidity expression for submerged vegetation was obtained by means of multiple linear regression method.The results show that the submerged vegetation has three states under different inflow conditions,and the each critical relative bending rigidity of individual submerged vegetation was determined for the different states of submerged vegetation.

  2. Elastic bending modulus of monolayer graphene

    Energy Technology Data Exchange (ETDEWEB)

    Lu Qiang; Huang Rui [Department of Aerospace Engineering and Engineering Mechanics, University of Texas, Austin, TX 78712 (United States); Arroyo, Marino [Department of Applied Mathematics 3, LaCaN, Universitat Politecnica de Catalunya (UPC), Barcelona 08034 (Spain)

    2009-05-21

    An analytic formula is derived for the elastic bending modulus of monolayer graphene based on an empirical potential for solid-state carbon atoms. Two physical origins are identified for the non-vanishing bending stiffness of the atomically thin graphene sheet, one due to the bond-angle effect and the other resulting from the bond-order term associated with the dihedral angles. The analytical prediction compares closely with ab initio energy calculations. Pure bending of graphene monolayers into cylindrical tubes is simulated by a molecular mechanics approach, showing slight nonlinearity and anisotropy in the tangent bending modulus as the bending curvature increases. An intrinsic coupling between bending and in-plane strain is noted for graphene monolayers rolled into carbon nanotubes. (fast track communication)

  3. [Preoperative fasting guidelines: an update].

    Science.gov (United States)

    López Muñoz, A C; Busto Aguirreurreta, N; Tomás Braulio, J

    2015-03-01

    Anesthesiology societies have issued various guidelines on preoperative fasting since 1990, not only to decrease the incidence of lung aspiration and anesthetic morbidity, but also to increase patient comfort prior to anesthesia. Some of these societies have been updating their guidelines, as such that, since 2010, we now have 2 evidence-based preoperative fasting guidelines available. In this article, an attempt is made to review these updated guidelines, as well as the current instructions for more controversial patients such as infants, the obese, and a particular type of ophthalmic surgery. Copyright © 2014 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  4. Interventions for preoperative smoking cessation

    DEFF Research Database (Denmark)

    Thomsen, Thordis; Villebro, Nete; Møller, Ann Merete

    2010-01-01

    and keywords (surgery) or (operation) or (anaesthesia) or (anesthesia). MEDLINE, EMBASE and CINAHL were also searched, combining tobacco- and surgery-related terms. Most recent search April 2010. Selection criteria Randomized controlled trials that recruited people who smoked prior to surgery, offered......Background Smokers have a substantially increased risk of postoperative complications. Preoperative smoking intervention may be effective in decreasing this incidence, and surgery may constitute a unique opportunity for smoking cessation interventions. Objectives The objective of this review...... was to assess the effect of preoperative smoking intervention on smoking cessation at the time of surgery and 12 months postoperatively and on the incidence of postoperative complications. Search strategy The specialized register of the Cochrane Tobacco Addiction Group was searched using the free text...

  5. Interventions for preoperative smoking cessation

    DEFF Research Database (Denmark)

    Thomsen, Thordis; Villebro, N.; Møller, Ann Merete;

    2010-01-01

    Background Smokers have a substantially increased risk of postoperative complications. Preoperative smoking intervention may be effective in decreasing this incidence, and surgery may constitute a unique opportunity for smoking cessation interventions. Objectives The objective of this review...... was to assess the effect of preoperative smoking intervention on smoking cessation at the time of surgery and 12 months postoperatively and on the incidence of postoperative complications. Search strategy The specialized register of the Cochrane Tobacco Addiction Group was searched using the free text......; pooled RR 10.76 (95% confidence interval (CI) 4.55 to 25.46, two trials) and RR 1.41 (95% CI 1.22 to 1.63, five trials) respectively. Four trials evaluating the effect on long-term smoking cessation found a significant effect; pooled RR 1.61 (95% CI 1.12 to 2.33). However, when pooling intensive...

  6. Ovalization of Tubes Under Bending and Compression

    Science.gov (United States)

    Demer, L J; Kavanaugh, E S

    1944-01-01

    An empirical equation has been developed that gives the approximate amount of ovalization for tubes under bending loads. Tests were made on tubes in the d/t range from 6 to 14, the latter d/t ratio being in the normal landing gear range. Within the range of the series of tests conducted, the increase in ovalization due to a compression load in combination with a bending load was very small. The bending load, being the principal factor in producing the ovalization, is a rather complex function of the bending moment, d/t ratio, cantilever length, and distance between opposite bearing faces. (author)

  7. Peeling, sliding, pulling and bending

    Science.gov (United States)

    Lister, John; Peng, Gunnar

    2016-11-01

    The peeling of an elastic sheet away from thin layer of viscous fluid is a simply-stated and generic problem, that involves complex interactions between the flow and elastic deformation on a range of length scales. Consider an analogue of capillary spreading, where a blister of injected viscous fluid spreads due to tension in the overlying elastic sheet. Here the tension is coupled to the deformation of the sheet, and thus varies in time and space. A key question is whether or not viscous shear stresses ahead of the blister are sufficient to prevent the sheet sliding inwards and relieving the tension. Our asymptotic analysis reveals a dichotomy between fast and slow spreading, and between two-dimensional and axisymmetric spreading. In combination with bending stresses and gravity, which may dominate parts of the flow but not others, there is a plethora of dynamical regimes.

  8. Bending Angle Prediction Model Based on BPNN-Spline in Air Bending Springback Process

    OpenAIRE

    Zhefeng Guo; Wencheng Tang

    2017-01-01

    In order to rapidly and accurately predict the springback bending angle in V-die air bending process, a springback bending angle prediction model on the combination of error back propagation neural network and spline function (BPNN-Spline) is presented in this study. An orthogonal experimental sample set for training BPNN-Spline is obtained by finite element simulation. Through the analysis of network structure, the BPNN-Spline black box function of bending angle prediction is established, an...

  9. A Numerical Study of the Spring-Back Phenomenon in Bending with a Rebar Bending Machine

    Directory of Open Access Journals (Sweden)

    Chang Hwan Choi

    2014-10-01

    Full Text Available Recently, the rebar bending methodology started to change from field processing to utilizing rebar bending machines at plant sites prior to transport to the construction locations. Computerized control of rebar plant bending machines provides more accurate and faster bending of rebars than the low quality inefficient field processing alternative. The bending process involves plastic deformation of rebars, where bending stress beyond the yield point of the material is applied. When the bending stress is removed, spring back is caused by the elastic restoring stress. Therefore, an accurate numerical analysis of the spring-back process is required to reduce the bending process errors. The most sensitive factors affecting the spring-back process are the bending radius, the bending angle, the diameter of the rebar, the friction coefficient, and the yielding strength of material. In this paper, we suggest a numerical modeling method using these factors. The finite element modeling of the dynamic mechanical behavior of the material during bending is performed using a commercial dynamic analysis program “DAFUL.” We use the least squares approach to derive the spring-back deflection as a function of the rebar bending parameters.

  10. Do psychological interventions reduce preoperative anxiety?

    Science.gov (United States)

    Renouf, Tessa; Leary, Alison; Wiseman, Theresa

    The systematic review investigates whether, during preoperative assessments, nurse-delivered psychological interventions reduce anxiety levels preoperatively for patients undergoing elective surgery. Seventeen studies met the inclusion criteria for data extraction and in-depth critiquing. Of these, two were discarded due to lack of validity, while the remaining studies were organised thematically in a narrative synthesis, generating two principal results: patients' preoperative anxieties were lowered by nurse-delivered general preoperative psychological interventions; and patients valued individualised preoperative interventions delivered by nurses. However, the single oncology study in the review showed an elevation in preoperative anxiety, regardless of intervention, and highlights the need for more research in this under-reviewed area. In the meantime, the authors believe that service improvements should be implemented to ensure that, where possible, psychological preoperative interventions are individualised.

  11. Discontinious Galerkin formulations for thin bending problems

    NARCIS (Netherlands)

    Nguyen, T.D.

    2008-01-01

    A structural thin bending problem is essentially associated with a fourth-order partial differential equation. Within the finite element framework, the numerical solution of thin bending problems demands the use of C^1 continuous shape functions. Elements using these functions are challenging and di

  12. Restorying the Self: Bending toward Textual Justice

    Science.gov (United States)

    Thomas, Ebony Elizabeth; Stornaiuolo, Amy

    2016-01-01

    In this essay, Ebony Elizabeth Thomas and Amy Stornaiuolo explore new trends in reader response for a digital age, particularly the phenomenon of bending texts using social media. They argue that bending is one form of "restorying," a process by which people reshape narratives to represent a diversity of perspectives and experiences that…

  13. Anharmonic Bend-Stretch Coupling in Water

    NARCIS (Netherlands)

    Lindner, Jörg; Vöhringer, Peter; Pshenichnikov, Maxim S.; Cringus, Dan; Wiersma, Douwe A.; Corkum, Paul; Jonas, David M.; Miller, R.J. Dwayne.; Weiner, Andrew M.

    2006-01-01

    Following excitation of the H-O-H bending mode of water molecules in solution the stretching mode region is monitored over its entire width. The anharmonic coupling between the two modes results in a substantial change of the transient stretch absorption that decays with the bend depopulation time.

  14. Bandwidth engineering of photonic crystal waveguide bends

    DEFF Research Database (Denmark)

    Borel, Peter Ingo; Frandsen, Lars Hagedorn; Harpøth, Anders;

    2004-01-01

    An effective design principle has been applied to photonic crystal waveguide bends fabricated in silicon-on-insulator material using deep UV lithography resulting in a large increase in the low-loss bandwidth of the bends. Furthermore, it is experimentally demonstrated that the absolute bandwidth...

  15. Bends and splitters in graphene nanoribbon waveguides

    DEFF Research Database (Denmark)

    Zhu, Xiaolong; Yan, Wei; Mortensen, N. Asger

    2013-01-01

    We investigate the performance of bends and splitters in graphene nanoribbon waveguides. Although the graphene waveguides are lossy themselves, we show that bends and splitters do not induce any additional loss provided that the nanoribbon width is sub-wavelength. We use transmission line theory...

  16. Tube-bending scale/protractor

    Science.gov (United States)

    Millett, A. U.

    1977-01-01

    Combination protractor and scale for measuring tube bends has novel pivot that allows tube to remain in contact with scale arms for all bend angles. Device permits rapid and accurate scribing and measurement of mockup fluid lines to obtain production data.

  17. Plausible cloth animation using dynamic bending model

    Institute of Scientific and Technical Information of China (English)

    Chuan Zhou; Xiaogang Jin; Charlie C.L. Wang; Jieqing Feng

    2008-01-01

    Simulating the mechanical behavior of a cloth is a very challenging and important problem in computer animation. The models of bending in most existing cloth simulation approaches are taking the assumption that the cloth is little deformed from a plate shape.Therefore, based on the thin-plate theory, these bending models do not consider the condition that the current shape of the cloth under large deformations cannot be regarded as the approximation to that before deformation, which leads to an unreal static bending. [This paper introduces a dynamic bending model which is appropriate to describe large out-plane deformations such as cloth buckling and bending, and develops a compact implementation of the new model on spring-mass systems. Experimental results show that wrinkles and folds generated using this technique in cloth simulation, can appear and vanish in a more natural way than other approaches.

  18. Wire and Cable Cold Bending Test

    Science.gov (United States)

    Colozza, Anthony

    2010-01-01

    One of the factors in assessing the applicability of wire or cable on the lunar surface is its flexibility under extreme cold conditions. Existing wire specifications did not address their mechanical behavior under cold, cryogenic temperature conditions. Therefore tests were performed to provide this information. To assess this characteristic 35 different insulated wire and cable pieces were cold soaked in liquid nitrogen. The segments were then subjected to bending and the force was recorded. Any failure of the insulation or jacketing was also documented for each sample tested. The bending force tests were performed at room temperature to provide a comparison to the change in force needed to bend the samples due to the low temperature conditions. The results from the bending tests were plotted and showed how various types of insulated wire and cable responded to bending under cold conditions. These results were then used to estimate the torque needed to unroll the wire under these low temperature conditions.

  19. Preoperative localization in primary hyperparathyroidism

    Energy Technology Data Exchange (ETDEWEB)

    Han, Sanson; Kitamura, Hiroyuki; Takagita, Shin-ichi; Maetani, Toshiki; Iwahashi, Yuka; Miyazaki, Masakazu; Yamamoto, Norio [Tenri Hospital, Nara (Japan)

    1998-04-01

    Between 1992 and 1996, 31 cases (8 men and 23 women) with primary hyperparathyroidism (PHPT) were treated in our department. In this study, we compared which of the preoperative localization methods was most useful in the detection of PHPT. The sensitivity for detection of abnormal parathyroid glands was 88.6% on ultrasonography (US), 76.9% on magnetic resonance imaging (MRI), 74.3% on Tl-Tc subtraction scintigraphy and 68.8% on computed tomography. We concluded that US should be performed first, with MRI as a supplementary method, for the detection of abnormal parathyroid glands and the evaluation of invasion within the body. (author)

  20. Preoperative Evaluation for Noncardiac Surgery.

    Science.gov (United States)

    Cohn, Steven L

    2016-12-06

    This issue provides a clinical overview of preoperative evaluation for noncardiac surgery, focusing on risk factors, elements of evaluation, medication management, and practice improvement. The content of In the Clinic is drawn from the clinical information and education resources of the American College of Physicians (ACP), including MKSAP (Medical Knowledge and Self-Assessment Program). Annals of Internal Medicine editors develop In the Clinic in collaboration with the ACP's Medical Education and Publishing divisions and with the assistance of additional science writers and physician writers.

  1. 49 CFR 195.212 - Bending of pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Bending of pipe. 195.212 Section 195.212... PIPELINE Construction § 195.212 Bending of pipe. (a) Pipe must not have a wrinkle bend. (b) Each field bend must comply with the following: (1) A bend must not impair the serviceability of the pipe. (2) Each...

  2. A derivation of the generalized model of strains during bending of metal tubes at bending machines

    OpenAIRE

    Śloderbach Z.

    2014-01-01

    According to the postulate concerning a local change of the “actual active radius” with a bending angle in the bend zone, a generalized model of strain during metal tube bending was derived. The tubes should be subjected to bending at tube bending machines by the method of wrapping at the rotating template and with the use of a lubricated steel mandrel. The model is represented by three components of strain in the analytic form, including displacement of the neutral axis. Generalization of th...

  3. Preoperative fasting time in children.

    LENUS (Irish Health Repository)

    Adeel, S

    2012-02-01

    The aim of preoperative fasting is to prevent regurgitation and pulmonary aspiration while limiting potential problems of thirst, dehydration and hypoglycaemia. The American Society of Anaesthesiologists (ASA) has suggested guidelines for preoperative fasting for children undergoing elective surgery. We did a postal survey to determine the current practice regarding these guidelines amongst all specialist registrars in anaesthesia in Ireland. A questionnaire was sent to all specialist registrars in anaesthesia (90 in total), 60 (67%) were returned and analysed. The question asked was how long children should be kept fasting before elective surgery. The results of our survey suggest that most of the respondents are following the ASA guidelines for clear fluids and solids however there were differing opinion regarding the duration of fasting for formula milk and breast milk. In conclusion, we would recommend greater awareness and collaboration between anaesthetists, nurses and surgeons to ensure that fasting instructions are consistent with the ASA guidelines and that patient and their parents understand these directives as well.

  4. Low Loss S-Bend Structure With Tapered Curved Waveguides

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A novel S-bend with tapered curved waveguides is proposed. The normalized transmitted power is greater than the conventional bend with weakly guided waveguides. Small size and low loss can be reached by the proposed S-bend.

  5. Bending stresses in Facetted Glass Shells

    DEFF Research Database (Denmark)

    Bagger, Anne; Jönsson, Jeppe; Almegaard, Henrik

    2008-01-01

    A shell structure of glass combines a highly effective structural principle with a material of optimal permeability to light. A facetted shell structure has a piecewise plane geometry, and together the facets form an approximation to a curved surface. A distributed load on a plane-based facetted...... structure will locally cause bending moments in the loaded facets. The bending stresses are dependent on the stiffness of the joints. Approximate solutions are developed to estimate the magnitude of the bending stresses. A FE-model of a facetted glass shell structure is used to validate the expressions...

  6. Bidirectional bending splitter of designer surface plasmons

    Science.gov (United States)

    Jin Zhou, Yong; Jiang, Quan; Jun Cui, Tie

    2011-09-01

    We propose and experimentally verify a bidirectional bending splitter of designer surface plasmons which is composed of two metallic gratings of trapezoid grooves. A metal wire is used to excite the designer surface plasmons propagating along the gratings. A full-wave numerical method has been used to simulate the performance of the bending splitter. The experimental verifications in the microwave frequencies have excellent agreements to the simulations. It is demonstrated that the splitter can not only split the electromagnetic waves at different frequencies, but also guide the electromagnetic waves effectively for large-angle bending.

  7. Preoperative information management system using wireless PDAs.

    Science.gov (United States)

    Sawa, Tomohiro; Okahara, Masaharu; Santo, Masayuki; Schmidt, Ulrich; Nakata, Yoshinori; Morita, Shigeho; Ohno-Machado, Lucila

    2003-01-01

    Personal Digital Assistant (PDA) and wireless communication are currently available in clinical settings. We developed wireless PDA software that assists anesthesiologists in pre-operative patient assessment. The device communicates with the hospital information system through a wireless LAN and is equipped with pre-programmed data entry templates for pre-operative assessment. As a preliminary test of the device, we randomly assigned residents in preoperative assessment to an intervention and a control arm and compared the results.

  8. Preoperative evaluation of oesophageal adenocarcinoma.

    Science.gov (United States)

    Khanna, Lauren G; Gress, Frank G

    2015-02-01

    The preoperative evaluation of oesophageal adenocarcinoma involves endoscopic ultrasound (EUS), computed tomography (CT), and positron emission tomography (PET). With routine Barrett's oesophagus surveillance, superficial cancers are often identified. EUS, CT and PET have a limited role in the staging of superficial tumours. Standard EUS has limited accuracy, but high frequency ultrasound miniprobes are valuable for assessing tumour stage in superficial tumours. However, the best method for determining depth of invasion, and thereby stage of disease, is endoscopic mucosal resection. In contrast, in advanced oesophageal cancers, a multi-modality approach is crucial. Accurate tumour staging is very important since the treatment of advanced cancers involves a combination of chemotherapy, radiation, and surgery. EUS is very useful for staging of the tumour and nodes. High frequency ultrasound miniprobes provide the ability to perform staging when the lesion is obstructing the oesophageal lumen. CT and PET provide valuable information regarding node and metastasis staging.

  9. EFFECT OF CHANNEL BENDS ON TRANSVERSE MIXING

    African Journals Online (AJOL)

    user

    1986-09-01

    Sep 1, 1986 ... The first study of transverse mixing in bends of turbulent open channel flows ... Rozovskii's transverse velocity distribution for fully developed turbulent flow ... Yotsukura et al (3) employed a simulation procedure to predict the.

  10. Bending artificial muscle from nylon filaments

    Science.gov (United States)

    Mirvakili, Seyed M.; Hunter, Ian W.

    2016-04-01

    Highly oriented nylon and polyethylene fibers shrink in length and expand in diameter when heated. Using this property, in this work, for the first time we are introducing a type of bending artificial muscle from nylon filaments such as fishing line. Reversible radius of curvature of 0.23 mm-1 was achieved with maximum reversible bending amplitude of 115 mm for the nylon bending actuator. Peak force of up to 2040 mN was measured with a catch-state force of up to 40% of the active force. A 3 dB roll-off frequency of around 0.7 Hz was observed in the frequency response of the bending actuator in water.

  11. slice of a LEP bending magnet

    CERN Multimedia

    This is a slice of a LEP dipole bending magnet, made as a concrete and iron sandwich The bending field needed in LEP is small (about 1000 Gauss), equivalent to two of the magnets people stick on fridge doors. Because it is very difficult to keep a low field steady, a high field was used in iron plates embedded in concrete. A CERN breakthrough in magnet design, LEP dipoles can be tuned easily and are cheaper than conventional magnets.

  12. Slice of a LEP bending magnet

    CERN Document Server

    This is a slice of a LEP dipole bending magnet, made as a concrete and iron sandwich. The bending field needed in LEP is small (about 1000 Gauss), equivalent to two of the magnets people stick on fridge doors. Because it is very difficult to keep a low field steady, a high field was used in iron plates embedded in concrete. A CERN breakthrough in magnet design, LEP dipoles can be tuned easily and are cheaper than conventional magnets.

  13. Pipes under internal pressure and bending

    CERN Document Server

    Catinaccio, A

    2009-01-01

    This article covers the general behaviour of a straight uniform pipe, with built-in open ends, subject to internal pressure and in plane bending or curvature. It is intended as a summary of the basic equations driving the unintuitive phenomena of bending and instability of pipes under internal pressure. The analysis covers in addition the investigation of opposite pressure stabilisation effects that can be observed in some orthotropic material pipes like composite pressure hoses.

  14. A transparent bending-insensitive pressure sensor

    Science.gov (United States)

    Lee, Sungwon; Reuveny, Amir; Reeder, Jonathan; Lee, Sunghoon; Jin, Hanbit; Liu, Qihan; Yokota, Tomoyuki; Sekitani, Tsuyoshi; Isoyama, Takashi; Abe, Yusuke; Suo, Zhigang; Someya, Takao

    2016-05-01

    Measuring small normal pressures is essential to accurately evaluate external stimuli in curvilinear and dynamic surfaces such as natural tissues. Usually, sensitive and spatially accurate pressure sensors are achieved through conformal contact with the surface; however, this also makes them sensitive to mechanical deformation (bending). Indeed, when a soft object is pressed by another soft object, the normal pressure cannot be measured independently from the mechanical stress. Here, we show a pressure sensor that measures only the normal pressure, even under extreme bending conditions. To reduce the bending sensitivity, we use composite nanofibres of carbon nanotubes and graphene. Our simulations show that these fibres change their relative alignment to accommodate bending deformation, thus reducing the strain in individual fibres. Pressure sensitivity is maintained down to a bending radius of 80 μm. To test the suitability of our sensor for soft robotics and medical applications, we fabricated an integrated sensor matrix that is only 2 μm thick. We show real-time (response time of ∼20 ms), large-area, normal pressure monitoring under different, complex bending conditions.

  15. Bending sound in graphene: Origin and manifestation

    Energy Technology Data Exchange (ETDEWEB)

    Adamyan, V.M., E-mail: vadamyan@onu.edu.ua [Department of Theoretical Physics, Odessa I.I. Mechnikov National University, 2 Dvoryanska St., Odessa 65026 (Ukraine); Bondarev, V.N., E-mail: bondvic@onu.edu.ua [Department of Theoretical Physics, Odessa I.I. Mechnikov National University, 2 Dvoryanska St., Odessa 65026 (Ukraine); Zavalniuk, V.V., E-mail: vzavalnyuk@onu.edu.ua [Department of Theoretical Physics, Odessa I.I. Mechnikov National University, 2 Dvoryanska St., Odessa 65026 (Ukraine); Department of Fundamental Sciences, Odessa Military Academy, 10 Fontanska Road, Odessa 65009 (Ukraine)

    2016-11-11

    Highlights: • The origin of sound-like dispersion of graphene bending mode is disclosed. • The speed of graphene bending sound is determined. • The renormalized graphene bending rigidity is derived. • The intrinsic corrugations of graphene are estimated. - Abstract: It is proved that the acoustic-type dispersion of bending mode in graphene is generated by the fluctuation interaction between in-plane and out-of-plane terms in the free energy arising with account of non-linear components in the graphene strain tensor. In doing so we use an original adiabatic approximation based on the alleged (confirmed a posteriori) significant difference of sound speeds for in-plane and bending modes. The explicit expression for the bending sound speed depending only on the graphene mass density, in-plane elastic constants and temperature is deduced as well as the characteristics of the microscopic corrugations of graphene. The obtained results are in good quantitative agreement with the data of real experiments and computer simulations.

  16. A transparent bending-insensitive pressure sensor.

    Science.gov (United States)

    Lee, Sungwon; Reuveny, Amir; Reeder, Jonathan; Lee, Sunghoon; Jin, Hanbit; Liu, Qihan; Yokota, Tomoyuki; Sekitani, Tsuyoshi; Isoyama, Takashi; Abe, Yusuke; Suo, Zhigang; Someya, Takao

    2016-05-01

    Measuring small normal pressures is essential to accurately evaluate external stimuli in curvilinear and dynamic surfaces such as natural tissues. Usually, sensitive and spatially accurate pressure sensors are achieved through conformal contact with the surface; however, this also makes them sensitive to mechanical deformation (bending). Indeed, when a soft object is pressed by another soft object, the normal pressure cannot be measured independently from the mechanical stress. Here, we show a pressure sensor that measures only the normal pressure, even under extreme bending conditions. To reduce the bending sensitivity, we use composite nanofibres of carbon nanotubes and graphene. Our simulations show that these fibres change their relative alignment to accommodate bending deformation, thus reducing the strain in individual fibres. Pressure sensitivity is maintained down to a bending radius of 80 μm. To test the suitability of our sensor for soft robotics and medical applications, we fabricated an integrated sensor matrix that is only 2 μm thick. We show real-time (response time of ∼20 ms), large-area, normal pressure monitoring under different, complex bending conditions.

  17. Forming characteristics of thin-walled tube bending process with small bending radius

    Institute of Scientific and Technical Information of China (English)

    LI Heng; YANG He; ZHAN Mei; GU Rui-Jie

    2006-01-01

    Currently requirements of thin-walled tube with small bending radius cause the defects such as wrinkling,overthinning and cross-section distortion more prone to occur in bending process. Based on the analysis of the forming characteristics by analytical and experimental methods,a complete 3D elastic-plastic FEM model of the process was developed using ABAQUS/Explicit code,including bending process,balls retracting and unloading process,and thus the plastic deformation characteristics with small bending radius were investigated. The main results show that: 1) The utmost deformation feature of the NC bending process is its continuous progressive deformation. 2) The occurring conditions of the defects such as wrinkling and tension instability in the process are obtained. The wrinkling is traditional on the double compressive stresses state and the tension instability is on the double tension stresses state. 3) The enhanced non-uniform deformation in thin-walled tube with small bending radius is demonstrated by comparing the stress/ strains distributions under the 1.5D and 1D bending conditions. 4) For 1D small bending process,a new method-"stepped mandrel retraction" is proposed to improve the bending quality in experiment according to the FE simulation. The simulation results are verified by experiment.

  18. New Equation for Bending Development of Arbitrary Rods and Application to Palm Fronds Bending

    CERN Document Server

    Abdullah, Mikrajuddin

    2016-01-01

    A new general equation to explain bending of arbitrary rods (from arbitrary materials, cross sections, densities, strengthnesses, bending angles, etc) was proposed. This equation can solve several problems found in classical equations, which have many limitations such as only applies for small bending angles or must be solved using very complex schemes. Experiments were also conducted to confirm the theoretical predictions. The equation might be used to explain bending of palm fronds in a very simple way. The proposed equation may be used to obtain solution of several problems which are usually obtain with iteration procedures.

  19. Preoperative Smoking Status and Postoperative Complications

    DEFF Research Database (Denmark)

    Grønkjær, Marie; Eliasen, Marie; Skov-Ettrup, Lise Skrubbeltrang;

    2014-01-01

    To systematically review and summarize the evidence of an association between preoperative smoking status and postoperative complications elaborated on complication type.......To systematically review and summarize the evidence of an association between preoperative smoking status and postoperative complications elaborated on complication type....

  20. Bend-insensitive optical fibers for FTTH applications

    Science.gov (United States)

    Li, Ming-Jun

    2009-01-01

    This paper reviews recent development in bend-insensitive fibers for fiber-to-the-home (FTTH) applications. First, requirements for bend-insensitive fibers are discussed. Then different design approaches for reducing fiber bending loss are described and compared. A new bend-insensitive fiber using the nano-engineered ring design is presented in detail.

  1. Finite Element Simulation of Magnesium Alloy AZ31 Tube Bending

    Directory of Open Access Journals (Sweden)

    Wu Wenyun

    2016-01-01

    Full Text Available A finite element method based model has been developed for magnesium alloy AZ31 tube bending process simulation, using the tensile (for bend outer radius and compressive (for bend inner radius properties of the AZ31 alloy at the bending temperature of 150°C. The results shown that very high compressive stresses are developed in the bend inner radius, limiting the minimum bend radius for the AZ31 tube. The simulation results suggest the minimum centerline bend radius to the tube outer diameter ratio is 1.5 to 2. The maximum diameter to thickness ratio is 30.

  2. Tunable thermoelectric properties in bended graphene nanoribbons

    Science.gov (United States)

    Chang-Ning, Pan; Jun, He; Mao-Fa, Fang

    2016-07-01

    The ballistic thermoelectric properties in bended graphene nanoribbons (GNRs) are systematically investigated by using atomistic simulation of electron and phonon transport. We find that the electron resonant tunneling effect occurs in the metallic-semiconducting linked ZZ-GNRs (the bended GNRs with zigzag edge leads). The electron-wave quantum interference effect occurs in the metallic-metallic linked AA-GNRs (the bended GNRs with armchair edge leads). These different physical mechanisms lead to the large Seebeck coefficient S and high electron conductance in bended ZZ-GNRs/AA-GNRs. Combined with the reduced lattice thermal conduction, the significant enhancement of the figure of merit ZT is predicted. Moreover, we find that the ZTmax (the maximum peak of ZT) is sensitive to the structural parameters. It can be conveniently tuned by changing the interbend length of bended GNRs. The magnitude of ZT ranges from the 0.15 to 0.72. Geometry-controlled ballistic thermoelectric effect offers an effective way to design thermoelectric devices such as thermocouples based on graphene. Project supported by the National Natural Science Foundation of China (Grant No. 61401153) and the Natural Science Foundation of Hunan Province, China (Grant Nos. 2015JJ2050 and 14JJ3126).

  3. Pure plate bending in couple stress theories

    CERN Document Server

    Hadjesfandiari, Ali R; Dargush, Gary F

    2016-01-01

    In this paper, we examine the pure bending of plates within the framework of modified couple stress theory (M-CST) and consistent couple stress theory (C-CST). In this development, it is demonstrated that M-CST does not describe pure bending of a plate properly. Particularly, M-CST predicts no couple-stresses and no size effect for the pure bending of the plate into a spherical shell. This contradicts our expectation that couple stress theory should predict some size effect for such a deformation pattern. Therefore, this result clearly demonstrates another inconsistency of indeterminate symmetric modified couple stress theory (M-CST), which is based on considering the symmetric torsion tensor as the curvature tensor. On the other hand, the fully determinate skew-symmetric consistent couple stress theory (C-CST) predicts results for pure plate bending that tend to agree with mechanics intuition and experimental evidence. Particularly, C-CST predicts couple-stresses and size effects for the pure bending of the ...

  4. Tunable thermoelectric properties in bended graphene nanoribbons

    Institute of Scientific and Technical Information of China (English)

    潘长宁; 何军; 方卯发

    2016-01-01

    The ballistic thermoelectric properties in bended graphene nanoribbons (GNRs) are systematically investigated by using atomistic simulation of electron and phonon transport. We find that the electron resonant tunneling effect occurs in the metallic–semiconducting linked ZZ-GNRs (the bended GNRs with zigzag edge leads). The electron-wave quan-tum interference effect occurs in the metallic–metallic linked AA-GNRs (the bended GNRs with armchair edge leads). These different physical mechanisms lead to the large Seebeck coefficient S and high electron conductance in bended ZZ-GNRs/AA-GNRs. Combined with the reduced lattice thermal conduction, the significant enhancement of the figure of merit ZT is predicted. Moreover, we find that the ZTmax (the maximum peak of ZT) is sensitive to the structural parameters. It can be conveniently tuned by changing the interbend length of bended GNRs. The magnitude of ZT ranges from the 0.15 to 0.72. Geometry-controlled ballistic thermoelectric effect offers an effective way to design thermoelectric devices such as thermocouples based on graphene.

  5. 75 FR 71666 - Bend/Ft. Rock Ranger District; Deschutes National Forest; Deschutes County, OR; West Bend...

    Science.gov (United States)

    2010-11-24

    ... Forest Service Bend/Ft. Rock Ranger District; Deschutes National Forest; Deschutes County, OR; West Bend... Jeffries, District Ranger, Bend-Fort Rock Ranger District, Red Oaks Square, 1230 NE. Third Street, Suite A...-Fort Rock Ranger District, Red Oaks Square, 1230 NE. Third Street, Suite A-262, Bend, Oregon 97701...

  6. Bending Angle Prediction Model Based on BPNN-Spline in Air Bending Springback Process

    Directory of Open Access Journals (Sweden)

    Zhefeng Guo

    2017-01-01

    Full Text Available In order to rapidly and accurately predict the springback bending angle in V-die air bending process, a springback bending angle prediction model on the combination of error back propagation neural network and spline function (BPNN-Spline is presented in this study. An orthogonal experimental sample set for training BPNN-Spline is obtained by finite element simulation. Through the analysis of network structure, the BPNN-Spline black box function of bending angle prediction is established, and the advantage of BPNN-Spline is discussed in comparison with traditional BPNN. The results show a close agreement with simulated and experimental results by application examples, which means that the BPNN-Spline model in this study has higher prediction accuracy and better applicable ability. Therefore, it could be adopted in a numerical control bending machine system.

  7. Nuss procedure: Technical modifications to ease bending of the support bar and lateral stabilizer placement

    Science.gov (United States)

    Karakuş, Osman Zeki; Ulusoy, Oktay; Hakgüder, Gülce; Ateş, Oğuz; Olguner, Çimen; Olguner, Mustafa; Akgür, Feza Mirac

    2016-01-01

    BACKGROUND: Modifications defined to ease bending of the support bar and lateral stabilizer placement during minimal invasive repair of pectus excavatum (MIRPE) have not been reported. We herein report our experience with MIRPE including several technical modifications. METHODS: A total of 87 patients who underwent MIRPE were evaluated retrospectively. Technical modifications are (1) a template drawn preoperatively according to the anthropometric measurements, (2) more laterally placed thoracal incisions, (3) single existing incision for multiple support bars, (4) to secure lateral stabilizers to support bar in inverted position. RESULTS: The mean patient age was 11.2 ± 3.8 years. The mean operating time was 63.7 ± 18.7 min. The mean Haller index was 5.4 ± 2.1. Eight patients necessitated two support bars. The support bars were removed in 69 patients after the completion of treatment. Support bars were left in place 26.8 ± 4.3 months. Final chest contours of the 56 patients were evaluated as 12 months passed after support bar removal and excellent repair results were determined in 84.2%. CONCLUSION: Preoperative bending of the support bar according to anthropometric measurements and fixation of the lateral stabilizers to the support bar in inverted position facilitates bar shaping and lateral stabilizer placement. PMID:27512512

  8. Robotic Arm Comprising Two Bending Segments

    Science.gov (United States)

    Mehling, Joshua S.; Difler, Myron A.; Ambrose, Robert O.; Chu, Mars W.; Valvo, Michael C.

    2010-01-01

    The figure shows several aspects of an experimental robotic manipulator that includes a housing from which protrudes a tendril- or tentacle-like arm 1 cm thick and 1 m long. The arm consists of two collinear segments, each of which can be bent independently of the other, and the two segments can be bent simultaneously in different planes. The arm can be retracted to a minimum length or extended by any desired amount up to its full length. The arm can also be made to rotate about its own longitudinal axis. Some prior experimental robotic manipulators include single-segment bendable arms. Those arms are thicker and shorter than the present one. The present robotic manipulator serves as a prototype of future manipulators that, by virtue of the slenderness and multiple- bending capability of their arms, are expected to have sufficient dexterity for operation within spaces that would otherwise be inaccessible. Such manipulators could be especially well suited as means of minimally invasive inspection during construction and maintenance activities. Each of the two collinear bending arm segments is further subdivided into a series of collinear extension- and compression-type helical springs joined by threaded links. The extension springs occupy the majority of the length of the arm and engage passively in bending. The compression springs are used for actively controlled bending. Bending is effected by means of pairs of antagonistic tendons in the form of spectra gel spun polymer lines that are attached at specific threaded links and run the entire length of the arm inside the spring helix from the attachment links to motor-driven pulleys inside the housing. Two pairs of tendons, mounted in orthogonal planes that intersect along the longitudinal axis, are used to effect bending of each segment. The tendons for actuating the distal bending segment are in planes offset by an angle of 45 from those of the proximal bending segment: This configuration makes it possible to

  9. A fresh look at preoperative body washing

    Science.gov (United States)

    Tanner, Judith; Gould, Dinah; Jenkins, Philip; Hilliam, Rachel; Mistry, Neetesh; Walsh, Susannah

    2012-01-01

    National guidelines do not support preoperative body washing to reduce surgical site infections, instead recommending bathing or showering with soap. Yet preoperative body washing continues to be widely used in many hospitals across Europe. This paper suggests that existing trials of preoperative body washing, upon which guidelines are based, are dated and proposes a new investigation of preoperative body washing using modern definitions of surgical site infection with standardised patient follow up, modern surgical techniques and well designed trials. This paper provides a critique of existing guidelines and describes a randomised trial with 60 participants to compare the effect of soap and two antiseptic washing products on colony forming units (CFUs) for up to six hours. Chlorhexidine gluconate and octenidine were significantly more effective than soap in reducing CFUs in the underarm, and chlorhexidine was significantly more effective than soap in reducing CFUs in the groin. PMID:22448182

  10. Preoperative steroid in abdominal wall reconstruction

    DEFF Research Database (Denmark)

    Jensen, Kristian Kiim; Brøndum, Tina Lee; Belhage, Bo

    2016-01-01

    INTRODUCTION: Preoperative administration of high-dose glucocorticoid leads to improved recovery and decreased length of stay after abdominal surgery. Even so, studies on administration of glucocorticoids for patients undergoing abdominal wall reconstruction (AWR) for giant ventral hernia repair ...

  11. Preoperative alcohol cessation prior to elective surgery

    DEFF Research Database (Denmark)

    Oppedal, Kristian; Møller, Ann Merete; Pedersen, Bolette

    2012-01-01

    Hazardous drinking has been associated with an increased postoperative complication rate after surgery. Common complications include postoperative infections, cardiopulmonary complications, and bleeding episodes. Preoperative abstinence may to some degree reverse alcohol-induced pathophysiological...

  12. Preoperative steroid in abdominal wall reconstruction

    DEFF Research Database (Denmark)

    Jensen, Kristian Kiim; Brøndum, Tina Lee; Belhage, Bo;

    2016-01-01

    INTRODUCTION: Preoperative administration of high-dose glucocorticoid leads to improved recovery and decreased length of stay after abdominal surgery. Even so, studies on administration of glucocorticoids for patients undergoing abdominal wall reconstruction (AWR) for giant ventral hernia repair ...

  13. Preoperative education for lumbar surgery for radiculopathy

    OpenAIRE

    Louw, A; Louw, Q; L. Crous

    2009-01-01

    To date no studies have been published on preoperative education forpatients who had lumbar surgery. The aim of this study was to determine if there is a demand for preoperative education for patients who had lumbar surgery for radiculopathy. A convenience sample of 47 patients who had lumbar surgery and a random sample of 141 physiotherapists involved in treating patients who had lumbar surgery completed a newly developed spinal surgery questionnaire. The data were analyzed using descriptive...

  14. Preoperative prediction of severe postoperative pain.

    Science.gov (United States)

    Kalkman, C J; Visser, K; Moen, J; Bonsel, G J; Grobbee, D E; Moons, K G M

    2003-10-01

    We developed and validated a prediction rule for the occurrence of early postoperative severe pain in surgical inpatients, using predictors that can be easily documented in a preoperative setting. A cohort of surgical inpatients (n=1416) undergoing various procedures except cardiac surgery and intracranial neurosurgery in a University Hospital were studied. Preoperatively the following predictors were collected: age, gender, type of scheduled surgery, expected incision size, blood pressure, heart rate, Quetelet index, the presence and severity of preoperative pain, health-related quality of life the (SF-36), Spielberger's State-Trait Anxiety Inventory (STAI) and the Amsterdam Preoperative Anxiety and Information Scale (APAIS). The outcome was the presence of severe postoperative pain (defined as Numeric Rating Scale > or =8) within the first hour postoperatively. Multivariate logistic regression in combination with bootstrapping techniques (as a method for internal validation) was used to derive a stable prediction model. Independent predictors of severe postoperative pain were younger age, female gender, level of preoperative pain, incision size and type of surgery. The area under the receiver operator characteristic (ROC) curve was 0.71 (95% CI: 0.68-0.74). Adding APAIS scores (measures of preoperative anxiety and need for information), but not STAI, provided a slightly better model (ROC area 0.73). The reliability of this extended model was good (Hosmer and Lemeshow test p-value 0.78). We have demonstrated that severe postoperative pain early after awakening from general anesthesia can be predicted with a scoring rule, using a small set of variables that can be easily obtained from all patients at the preoperative visit. Before this internally validated preoperative prediction rule can be applied in clinical practice to support anticipatory pain management, external validation in other clinical settings is necessary.

  15. Tubular lining material for pipelines having bends

    Energy Technology Data Exchange (ETDEWEB)

    Moringa, A.; Sakaguchi, Y.; Hyodo, M.; Yagi, I.

    1987-03-24

    A tubular lining material for pipelines having bends or curved portions comprises a tubular textile jacket made of warps and wefts woven in a tubular form overlaid with a coating of a flexible synthetic resin. It is applicable onto the inner surface of a pipeline having bends or curved portions in such manner that the tubular lining material with a binder onto the inner surface thereof is inserted into the pipeline and allowed to advance within the pipeline, with or without the aid of a leading rope-like elongated element, while turning the tubular lining material inside out under fluid pressure. In this manner the tubular lining material is applied onto the inner surface of the pipeline with the binder being interposed between the pipeline and the tubular lining material. The lining material is characterized in that a part of all of the warps are comprised of an elastic yarn around which, over the full length thereof, a synthetic fiber yarn or yarns have been left-and/or right-handedly coiled. This tubular lining material is particularly suitable for lining a pipeline having an inner diameter of 25-200 mm and a plurality of bends, such as gas service pipelines or house pipelines, without occurrence of wrinkles in the lining material in a bend.

  16. RELIABILITY ANALYSIS OF BENDING ELIABILITY ANALYSIS OF ...

    African Journals Online (AJOL)

    eobe

    performance of any structural system be eva ... by the Joint crete slabs, bending, shear, deflection, reliability, design codes. ement such as ... could be sensitive to this distribution. Table 1: ..... Ang, A. H-S and Tang, W. H. Probability Concepts in.

  17. Monitoring the Bending Stiffness of DNA

    Science.gov (United States)

    Yuan, Chongli; Lou, Xiongwen; Rhoades, Elizabeth; Chen, Huimin; Archer, Lynden

    2007-03-01

    In eukaryotic cells, the accessibility of genomic sequences provides an inherent regulation mechanism for gene expression through variations in bending stiffness encoded by the nucleic acid sequence. Cyclization of dsDNA is the prevailing method for determining DNA bending stiffness. Recent cyclization data for short dsDNA raises several fundamental questions about the soundness of the cyclization method, particularly in cases where the probability of highly bent DNA conformations is low. We herein evaluate the role of T4 DNA ligase in the cyclization reaction by inserting an environmental sensitive base analogue, 2-amino purine, to the DNA molecule. By monitoring the 2-AP fluorescence under standard cyclization conditions, it is found that in addition to trapping highly-bent cyclic DNA conformations, T4 DNA ligase enhances the apparent base pair flip out rate, thus exaggerating the measured flexibility. This result is further confirmed using fluorescence anisotropy experiments. We show that fluorescence resonance energy transfer (FRET) measurements on suitably labeled dsDNA provides an alternative approach for quantifying the bending stiffness of short fragments. DNA bending stiffness results obtained using FRET are compared with literature values.

  18. Demonstration model of LEP bending magnet

    CERN Multimedia

    CERN PhotoLab

    1981-01-01

    To save iron and raise the flux density, the LEP bending magnet laminations were separated by spacers and the space between the laminations was filled with concrete. This is a demonstration model, part of it with the spaced laminations only, the other part filled with concrete.

  19. A process model for air bending

    NARCIS (Netherlands)

    de Vin, L.J.; de Vin, L.J.; Streppel, A.H.; Singh, U.P.; Kals, H.J.J.

    1996-01-01

    A so called `three-section¿ model for air bending is presented. It is assumed that a state of plane strain exists and that Bernoulli's law is valid. The material behaviour is described with Swift's equation, and the change of Young's modulus under deformation is addressed. As compared with other

  20. Design of a hydraulic bending machine

    Science.gov (United States)

    Steven G. Hankel; Marshall Begel

    2004-01-01

    To keep pace with customer demands while phasing out old and unserviceable test equipment, the staff of the Engineering Mechanics Laboratory (EML) at the USDA Forest Service, Forest Products Laboratory, designed and assembled a hydraulic bending test machine. The EML built this machine to test dimension lumber, nominal 2 in. thick and up to 12 in. deep, at spans up to...

  1. Spring-back deformation in tube bending

    Institute of Scientific and Technical Information of China (English)

    Da-xin E; Hua-hui He; Xiao-yi Liu; Ru-xin Ning

    2009-01-01

    The spring-back of a bending metal tube was studied through extensive experiments and finite element method (FEM) analysis. An approximate equation for the spring-back angle of bending was deduced. It is noted that the mechanical properties of the material (in a tubular form) are quite different from those found in the standard tensile tests (when the materials are in bar forms). This is one of the major reasons that result in the discrepancies in the outcomes of experimental study, FEM calculations, and spring-back analysis. It is therefore of crucial importance to study the mechanical properties of the materials in their tubular forms. The experiments and FEM simulations prove that the spring-back angle is significantly affected by the mechanical properties of the materials. The angle decreases accordingly with plastic modulus, but changes inversely with the hardening index and elastic modulus. The spring-back angle is also affected by the conditions of tube deformation: it increases accordingly with the relative bending radius but changes inversely with the relative wall thickness. In addition, the spring-back angle increases nonlinearly with the bending an-gle.

  2. Inelastic Deformation Analysis of Aluminum Bending Members

    Institute of Scientific and Technical Information of China (English)

    CHENG Ming; SHI Yongjiu; WANG Yuanqing

    2006-01-01

    Aluminum alloys are typical nonlinear materials, and consequently bending members made of this material exhibit a nonlinear behavior. Most design codes do not pay much attention to such deformations and adopt a simple linear analysis for the calculation of deflections. This paper presents an investigation of the nonlinear deformation of aluminum bending members using the finite-element analysis (FEA). The plastic adaptation coefficient, which can be used to limit the residual deflection, is introduced, and the influence of residual deflection is investigated. A method for evaluating the plastic adoption coefficient is proposed. This paper also shows the load-deflection curve of aluminum bending members and the influence of several parameters. A semi-empirical formula is derived, and some numerical examples are given by FEA. The coefficients of the semi-empirical formula are modified by the FEA results using the nonlinear fitting method. Based on these results, two improved design methods for strength and deformation of aluminum bending members are proposed. Through the comparison with test data, these methods are proved to be suitable for structural design.

  3. Probing the elastic limit of DNA bending

    CERN Document Server

    Le, Tung T

    2014-01-01

    Many structures inside the cell such as nucleosomes and protein-mediated DNA loops contain sharply bent double-stranded (ds) DNA. Therefore, the energetics of strong dsDNA bending constitutes an essential part of cellular thermodynamics. Although the thermomechanical behavior of long dsDNA is well described by the worm-like chain (WLC) model, the length limit of such elastic behavior remains controversial. To investigate the energetics of strong dsDNA bending, we measured the opening rate of small dsDNA loops with contour lengths of 40-200 bp using Fluorescence Resonance Energy Transfer (FRET). From the measured relationship of loop stability to loop size, we observed a transition between two separate bending regimes at a critical loop size below 100 bp. Above this loop size, the loop lifetime decreased with decreasing loop size in a manner consistent with an elastic bending stress. Below the critical loop size, however, the loop lifetime became less sensitive to loop size, indicative of softening of the doub...

  4. Finger-jointed beams in bending

    DEFF Research Database (Denmark)

    Andreasen, Lotte; Hoffmeyer, Preben

    1997-01-01

    An investigation of the dynamic and static fatique of finger-jointed beams in bending was carried out. Results were obtained for five different frequencies from static loading to a load cycle period of two minutes. A total of seven series were long-term tested and five series were short-term tested...

  5. Fuzzy model for Laser Assisted Bending Process

    Directory of Open Access Journals (Sweden)

    Giannini Oliviero

    2016-01-01

    Full Text Available In the present study, a fuzzy model was developed to predict the residual bending in a conventional metal bending process assisted by a high power diode laser. The study was focused on AA6082T6 aluminium thin sheets. In most dynamic sheet metal forming operations, the highly nonlinear deformation processes cause large amounts of elastic strain energy stored in the formed material. The novel hybrid forming process was thus aimed at inducing the local heating of the mechanically bent workpiece in order to decrease or eliminate the related springback phenomena. In particular, the influence on the extent of springback phenomena of laser process parameters such as source power, scan speed and starting elastic deformation of mechanically bent sheets, was experimentally assessed. Consistent trends in experimental response according to operational parameters were found. Accordingly, 3D process maps of the extent of the springback phenomena according to operational parameters were constructed. The effect of the inherent uncertainties on the predicted residual bending caused by the approximation in the model parameters was evaluated. In particular, a fuzzy-logic based approach was used to describe the model uncertainties and the transformation method was applied to propagate their effect on the residual bending.

  6. Aerosol deposition in bends with turbulent flow

    Energy Technology Data Exchange (ETDEWEB)

    McFarland, A.R.; Gong, H.; Wente, W.B. [Texas A& M Univ., College Station, TX (United States)] [and others

    1997-08-01

    The losses of aerosol particles in bends were determined numerically for a broad range of design and operational conditions. Experimental data were used to check the validity of the numerical model, where the latter employs a commercially available computational fluid dynamics code for characterizing the fluid flow field and Lagrangian particle tracking technique for characterizing aerosol losses. Physical experiments have been conducted to examine the effect of curvature ratio and distortion of the cross section of bends. If it curvature ratio ({delta} = R/a) is greater than about 4, it has little effect on deposition, which is in contrast with the recommendation given in ANSI N13.1-1969 for a minimum curvature ratio of 10. Also, experimental results show that if the tube cross section is flattened by 25% or less, the flattening also has little effect on deposition. Results of numerical tests have been used to develop a correlation of aerosol penetration through a bend as a function of Stokes number (Stk), curvature ratio ({delta}) and the bend angle ({theta}). 17 refs., 10 figs., 2 tabs.

  7. Head movements while steering around bends

    NARCIS (Netherlands)

    Erp, J.B.F. van; Oving, A.B.

    2012-01-01

    In this study, the determinants of head motions (rotations) when driving around bends were investigated when drivers viewed the scene through a head-mounted display. The scene camera was either fixed or coupled to head motions along 2 or 3 axes of rotation. Eight participants drove around a

  8. Experimental Characterization of Stretch-Bending Formability of AHSS Sheets

    Science.gov (United States)

    Kitting, Daniela; Ofenheimer, Aldo; Pauli, Heinrich; Till, Edwin T.

    2011-05-01

    Deformation conditions of combined stretching and bending are known to enhance material formability compared to forming conditions without bending (e.g. in-plane stretching). These phenomena can be observed for most conventional steel grades but is even more pronounced for Advanced High Strength Steel (AHSS) sheets. Consequently, there is an urgent need in industry to quantify the phenomena of enhanced material formability due to bending effects. In this work new stretch-bend test setups are presented which can be used in addition to the conventional Angular Stretch Bend Test to systematically investigate the influence of various stretch-bending deformation conditions on the formability of AHSS sheets.

  9. Bending effects on lasing action of semiconductor nanowires.

    Science.gov (United States)

    Yang, Weisong; Ma, Yaoguang; Wang, Yipei; Meng, Chao; Wu, Xiaoqin; Ye, Yu; Dai, Lun; Tong, Limin; Liu, Xu; Yang, Qing

    2013-01-28

    High flexibility has been one of advantages for one-dimensional semiconductor nanowires (NWs) in wide application of nanoscale integrated circuits. We investigate the bending effects on lasing action of CdSe NWs. Threshold increases and differential efficiency decreases gradually when we decrease the bending radius step by step. Red shift and mode reduction in the output spectra are also observed. The bending loss of laser oscillation is considerably larger than that of photoluminescence (PL), and both show the exponential relationship with the bending radius. Diameter and mode dependent bending losses are investigated. Furthermore, the polarizations of output can be modulated linearly by bending the NWs into different angles continuously.

  10. The Dependency of Nematic and Twist-bend Mesophase Formation on Bend Angle

    Science.gov (United States)

    Mandle, Richard J.; Archbold, Craig T.; Sarju, Julia P.; Andrews, Jessica L.; Goodby, John W.

    2016-11-01

    We have prepared and studied a family of cyanobiphenyl dimers with varying linking groups with a view to exploring how molecular structure dictates the stability of the nematic and twist-bend nematic mesophases. Using molecular modelling and 1D 1H NOESY NMR spectroscopy, we determine the angle between the two aromatic core units for each dimer and find a strong dependency of the stability of both the nematic and twist-bend mesophases upon this angle, thereby satisfying earlier theoretical models.

  11. Preoperative education for lumbar surgery for radiculopathy

    Directory of Open Access Journals (Sweden)

    A. Louw

    2009-02-01

    Full Text Available To date no studies have been published on preoperative education forpatients who had lumbar surgery. The aim of this study was to determine if there is a demand for preoperative education for patients who had lumbar surgery for radiculopathy. A convenience sample of 47 patients who had lumbar surgery and a random sample of 141 physiotherapists involved in treating patients who had lumbar surgery completed a newly developed spinal surgery questionnaire. The data were analyzed using descriptiveand inferential statistical tests. Results showed that 100% of the patients and 99% of therapists view preoperative education to be an important component for lumbar surgery for radiculopathy. The most important factors identifiedfor inclusion in preoperative educational programs were reason for surgery, risks associated with surgery, limitations following surgery and more education regarding pain. The preferred method of education delivery was verbal one-on-one education. This study demonstrates that there is a demand for preoperative education for patients who had lumbar surgery.

  12. [Preoperative assessment of lung disease patients.].

    Science.gov (United States)

    Ramos, Gilson; Ramos Filho, José; Pereira, Edísio; Junqueira, Marcos; Assis, Carlos Henrique C

    2003-02-01

    Lung complications are the most frequent causes of postoperative morbidity-mortality, especially in lung disease patients. So, those patients should be preoperatively carefully evaluated and prepared, both clinically and laboratorially. This review aimed at determining surgical risk and at establishing preoperative procedures to minimize peri and postoperative morbidity-mortality in lung disease patients. Major anesthetic-surgical repercussions in lung function have already been described. Similarly, we tried to select higher-risk patients, submitted or not to lung resection. To that end, clinical and laboratorial propedeutics were used. Finally, a proposal of a preoperative algorithm was presented for procedures with lung resection. Lung disease patients, especially those with chronic evolution, need to be preoperatively thoroughly evaluated. ASA physical status and Goldmans cardiac index are important risk forecasting factors for lung disease patients not candidates for lung resection. Adding to these criteria, estimated postoperative max VO2, FEV1 and diffusion capacity are mandatory for some patients submitted to lung resection. beta2-agonists and steroids should be considered in the preoperative period of these patients.

  13. The "X-Factor" index: a new parameter for the assessment of adolescent idiopathic scoliosis correction.

    Science.gov (United States)

    Sun, Yu Qing; Samartzis, Dino; Cheung, Kenneth M C; Wong, Yat Wa; Luk, Keith D K

    2011-01-01

    The correction rate (CR) and fulcrum bending correction index (FBCI) based on the fulcrum bending radiograph (FBR) were parameters introduced to measure the curve correcting ability; however, such parameters do not account for contributions by various, potential extraneous "X-Factors" (e.g. surgical technique, type and power of the instrumentation, anesthetic technique, etc.) involved in curve correction. As such, the purpose of the following study was to propose the concept of the "X-Factor Index" (XFI) as a new parameter for the assessment of the correcting ability of adolescent idiopathic scoliosis (AIS). A historical cohort radiographic analysis of the FBR in the setting of hook systems in AIS patients (Luk et al. in Spine 23:2303-2307, 1998) was performed to illustrate the concept of XFI. Thirty-five patients with AIS of the thoracic spine undergoing surgical correction were involved in the analysis. Plain posteroanterior (PA) plain radiographs were utilized and Cobb angles were obtained for each patient. Pre- and postoperative PA angles on standing radiograph and preoperative fulcrum bending angles were obtained for each patient. The fulcrum flexibility, curve CR, and FBCI were determined for all patients. The difference between the preoperative fulcrum bending angle and postoperative PA angle was defined as Angle(XF), which accounted for the correction contributed by "X-Factors". The XFI, designed to measure the curve correcting ability, was calculated by dividing Angle(XF) by the fulcrum flexibility. The XFI was compared with the curve CR and FBCI by re-evaluating the original data in the original paper (Luk et al. in Spine 23:2303-2307, 1998). The mean standing PA and FBR alignments of the main thoracic curve were 58.3° and 24.5°, respectively. The mean fulcrum flexibility was 58.8%. The mean postoperative standing PA alignment was 24.7°. The mean curve CR was 58.0% and the mean FBCI was 101.1%. The mean XFI was noted as 1.03%. The CR was significantly

  14. Oide Effect and Radiation in Bending Magnets

    CERN Document Server

    Blanco, Oscar; Bambade, Philip

    2014-01-01

    Including radiation effects during lattice design optimization is crucial in high energy accelerators. Oide effect and radiation in bending magnets are reviewed aiming to include them in the optical design process to minimize the IP beam size. The Oide double integral is expressed in simpler terms in order to speed up calculations, concluding in how longer quadrupoles with lower gradients may help reducing the Oide effect. Radiation in bending magnets is reviewed for linear lattices, generalizing to the case when the final dispersion is different from zero and making comparisons with theoretical results and particle tracking. An agreement between the theory, the implemented approximation included in MAPCLASS2 and the six-dimensional tracking in PLACET has been found.

  15. Vortex breakdown in simple pipe bends

    Science.gov (United States)

    Ault, Jesse; Shin, Sangwoo; Stone, Howard

    2016-11-01

    Pipe bends and elbows are one of the most common fluid mechanics elements that exists. However, despite their ubiquity and the extensive amount of research related to these common, simple geometries, unexpected complexities still remain. We show that for a range of geometries and flow conditions, these simple flows experience unexpected fluid dynamical bifurcations resembling the bubble-type vortex breakdown phenomenon. Specifically, we show with simulations and experiments that recirculation zones develop within the bends under certain conditions. As a consequence, fluid and particles can remain trapped within these structures for unexpectedly-long time scales. We also present simple techniques to mitigate this recirculation effect which can potentially have impact across industries ranging from biomedical and chemical processing to food and health sciences.

  16. Rock bending creep and disturbance effects

    Institute of Scientific and Technical Information of China (English)

    付志亮; 郑颖人; 刘元雪

    2008-01-01

    The bending creep and its disturbance effects of red sandstone rock beam and oil shale rock beam were studied by adopting the self-developed gravitation level style rock creep test machine and bending creep test system,and the constitutive equations were established.It is found that fracture morphology of rock beams under no disturbance load is regular,cracking position of fractures is on part of loading concentration,the crack starts from a neutral plane.However,fracture morphology of rock beams under disturbance load is irregular,cracking position of fractures deviates from a neutral plane.Delayed instability of rock beam occurs for some time under constant disturbance load.When disturbance load is beyond a certain range,suddenly instability of occurs rock beam in a certain time.The results show that there is a guiding significance for creep stability in the geotechnical engineering fields.

  17. Ultrasonic fatigue testing device under biaxial bending

    Directory of Open Access Journals (Sweden)

    C. Brugger

    2016-07-01

    Full Text Available A new fatigue testing device has been developed to test specimens under biaxial loading at 20 kHz. A flat smooth specimen with a disc geometry is placed on a torus frame and cyclically loaded at the center of its upper face. Disc bending generates a biaxial proportional stress state at the center of the lower face. Any positive loading ratio can be applied. A cast aluminum alloy (used to produce cylinder heads has been tested under biaxial bending using this device in order to determine its fatigue strength at 109 cycles under high hydrostatic pressure. Self-heating is moderate but macroscopic fatigue cracks after testing are very long. First results in VHCF regime are consistent with literature results obtained under similar stress state but in HCF regime and at 20 Hz.

  18. Thermal Analysis of Bending Under Tension Test

    DEFF Research Database (Denmark)

    Ceron, Ermanno; Martins, Paulo A.F.; Bay, Niels

    2014-01-01

    The tribological conditions in deep drawing can be simulated in the Bending Under Tension test to evaluate the performance of new lubricants, tool materials, etc. Deep drawing production with automatic handling runs normally at high rate. This implies considerable heating of the tools, which...... sometimes can cause lubricant film breakdown and galling. In order to replicate the production conditions in bending under tension testing it is thus important to control the tool/workpiece interface temperature. This can be done by pre-heating the tool, but it is essential that the interface temperature...... during testing is similar to the one in the production tool. A universal sheet tribo-tester has been developed, which can run multiple tests automatically from coil. This allows emulating the temperature increase as in production. The present work performs finite element analysis of the evolution...

  19. Parallel monostrand stay cable bending fatigue

    DEFF Research Database (Denmark)

    Winkler, Jan Pawel

    of damage and replacement of bridge stay cables due to wind and traffic-induced fatigue. The understanding of fatigue mechanisms in most steel structures is well established. However, in the case of cables composed of steel strands, many important aspects related with bending fatigue remain to be clarified......This dissertation investigates the bending fatigue response of high-strength steel monostrands and multistrand stay cables to cyclic transverse deformations. Increasing bridge stock numbers and a push for longer cable-supported span lengths have led to an increased number of reported incidents...... associated with variable loading, and different testing procedures. As most of the contemporary stay cables are comprised of a number of individual highstrength steel monostrands, the research study started with an extensive experimental work on the fatigue response of a single monostrand to cyclic flexural...

  20. Approach to hot bending process simulation

    Energy Technology Data Exchange (ETDEWEB)

    Carmignani, B.; Daneri, A.; Toselli, G. [ENEA, Bologna (Italy). Centro Ricerche Energia `E. Clementel` - Area Energia e Innovazione

    1995-06-01

    An approach to the simulation of the thermal shaping or bending of large steel sheets, by ABAQUS/Standard code, will be presented. A thermal source representation, which can produce a temperature distribution, adequate to the processes which must be considered, has been set up. Some problems connected with the hot sheet shaping or bending process simulation have been approached and calculations have been executed in order to single out how to perform the sheet heating, so that the required sheet shape may be obtained. The results for one reference model for different source situations and one heating line, object of the first phase of the analyses performed, will be presented and discussed. The work will be presented at the 8th International Abaqus Users` Conference at Paris, 31 May - 2 June 1995.

  1. Holey fibers for low bend loss

    Science.gov (United States)

    Nakajima, Kazuhide; Saito, Kotaro; Yamada, Yusuke; Kurokawa, Kenji; Shimizu, Tomoya; Fukai, Chisato; Matsui, Takashi

    2013-12-01

    Bending-loss insensitive fiber (BIF) has proved an essential medium for constructing the current fiber to the home (FTTH) network. By contrast, the progress that has been made on holey fiber (HF) technologies provides us with novel possibilities including non-telecom applications. In this paper, we review recent progress on hole-assisted type BIF. A simple design consideration is overviewed. We then describe some of the properties of HAF including its mechanical reliability. Finally, we introduce some applications of HAF including to high power transmission. We show that HAF with a low bending loss has the potential for use in various future optical technologies as well as in the optical communication network.

  2. Cyclic stretch-bending: mechanics, stability and formability

    NARCIS (Netherlands)

    Emmens, W.C.; van den Boogaard, Antonius H.

    2011-01-01

    Cyclic stretch-bending has been studied using the so-called Continuous-Bending-under-Tension (CBT) test. This is a modified tensile test where the specimen is subjected to repetitive bending at the same time. A wide variety of materials have been tested this way. A simple mechanical model is

  3. Wooden Model of Wide AA Bending Magnet

    CERN Multimedia

    1978-01-01

    The very particular lattice of the AA required 2 types of dipoles (bending magnets: BLG, long and narrow; BST, short and wide). The wide ones had a steel length of 2.71 m, a "good field" width of 0.564 m, and a weight of about 75 t. Here we see a wooden model, built in 1978, to gain dimensional experience with such a monster.

  4. Electron cooling device without bending magnets

    Science.gov (United States)

    Sharapa, A. N.; Shemyakin, A. V.

    1993-11-01

    The scheme of an axisymmetric electron cooling device without bending magnets is proposed. Solutions for the most important elements, i.e., a gun and a recuperator, are considered. The main characteristics of the recuperator of the Faraday cup type having a reflector and a gun with a ring emitter are explored. In the gun, the beam is formed, the diameter of which is 40 mm and the dimension of a disturbance region is several millimeters.

  5. AA, assembly of wide bending magnet

    CERN Multimedia

    1980-01-01

    The very particular lattice of the AA required 2 types of dipoles (bending magnets; BST, short and wide; BLG, long and narrow). The wide ones had a steel length of 2.71 m, a "good field" width of 0.564 m, and a weight of about 75 t. Here we see the copper coils being hoisted onto the lower half of a BST. See also 7811105, 8006050. For a BLG, see 8001044.

  6. Drag Reduction, from Bending to Pruning

    CERN Document Server

    Lopez, Diego; Michelin, Sébastien; de Langre, Emmanuel

    2013-01-01

    Most plants and benthic organisms have evolved efficient reconfiguration mechanisms to resist flow-induced loads. These mechanisms can be divided into bending, in which plants reduce their sail area through elastic deformation, and pruning, in which the loads are decreased through partial breakage of the structure. In this work, we show by using idealized models that these two mechanisms or, in fact, any combination of the two, are equally efficient to reduce the drag experienced by terrestrial and aquatic vegetation.

  7. Big Bend National Park, TX, USA, Mexico

    Science.gov (United States)

    1991-01-01

    The Sierra del Carmen of Mexico, across the Rio Grande River from Big Bend National Park, TX, (28.5N, 104.0W) is centered in this photo. The Rio Grande River bisects the scene; Mexico to the east, USA to the west. The thousand ft. Boquillas limestone cliff on the Mexican side of the river changes colors from white to pink to lavender at sunset. This severely eroded sedimentary landscape was once an ancient seabed later overlaid with volcanic activity.

  8. Multiculturalism, Gender and Bend it Like Beckham

    Directory of Open Access Journals (Sweden)

    Gamal Abdel-Shehid

    2015-06-01

    Full Text Available In this article, we explore the efficacy of sport as an instrument for social inclusion through an analysis of the film Bend it Like Beckham. The film argues for the potential of sport to foster a more inclusive society in terms of multiculturalism and gender equity by showing how a hybrid culture can be forged through the microcosm of an English young women’s football club, while simultaneously challenging assumptions about traditional masculinities and femininities. Yet, despite appearances, Bend it Like Beckham does little to challenge the structure of English society. Ultimately, the version of multiculturalism offered by the film is one of assimilation to a utopian English norm. This conception appears progressive in its availability to all Britons regardless of ethnicity, but falls short of conceptions of hybrid identity that do not privilege one hegemonic culture over others. Likewise, although the film presents a feminist veneer, underneath lurks a troubling reassertion of the value of chastity, masculinity, and patriarchy. Bend it Like Beckham thus provides an instructive case study for the potential of sport as a site of social inclusion because it reveals how seductive it is to imagine that structural inequalities can be overcome through involvement in teams.

  9. SYMPLECTIC SOLUTION SYSTEM FOR REISSNER PLATE BENDING

    Institute of Scientific and Technical Information of China (English)

    姚伟岸; 隋永枫

    2004-01-01

    Based on the Hellinger-Reissner variatonal principle for Reissner plate bending and introducing dual variables, Hamiltonian dual equations for Reissner plate bending were presented. Therefore Hamiltonian solution system can also be applied to Reissner plate bending problem, and the transformation from Euclidian space to symplectic space and from Lagrangian system to Hamiltonian system was realized. So in the symplectic space which consists of the original variables and their dual variables, the problem can be solved via effective mathematical physics methods such as the method of separation of variables and eigenfunction-vector expansion. All the eigensolutions and Jordan canonical form eigensolutions for zero eigenvalue of the Hamiltonian operator matrix are solved in detail,and their physical meanings are showed clearly. The adjoint symplectic orthonormal relation of the eigenfunction vectors for zero eigenvalue are formed. It is showed that the all eigensolutions for zero eigenvalue are basic solutions of the Saint-Venant problem and they form a perfect symplectic subspace for zero eigenvalue. And the eigensolutions for nonzero eigenvalue are covered by the Saint-Venant theorem. The symplectic solution method is not the same as the classical semi- inverse method and breaks through the limit of the traditional semi-inverse solution. The symplectic solution method will have vast application.

  10. Pre-operative fasting guidelines: an update

    DEFF Research Database (Denmark)

    Søreide, E; Eriksson, L I; Hirlekar, G

    2005-01-01

    Liberal pre-operative fasting routines have been implemented in most countries. In general, clear fluids are allowed up to 2 h before anaesthesia, and light meals up to 6 h. The same recommendations apply for children and pregnant women not in labour. In children......Liberal pre-operative fasting routines have been implemented in most countries. In general, clear fluids are allowed up to 2 h before anaesthesia, and light meals up to 6 h. The same recommendations apply for children and pregnant women not in labour. In children...

  11. 77 FR 36012 - PPL Bell Bend, LLC; Bell Bend Nuclear Power Plant Combined License Application; Notice of Intent...

    Science.gov (United States)

    2012-06-15

    ... COMMISSION PPL Bell Bend, LLC; Bell Bend Nuclear Power Plant Combined License Application; Notice of Intent... its Bell Bend Nuclear Power Plant (BBNPP) site, located west of the existing Susquehanna Steam... by relocating the power block footprint and other plant components. For purposes of developing...

  12. 78 FR 4465 - PPL Bell Bend, LLC; Combined License Application for Bell Bend Nuclear Power Plant; Exemption

    Science.gov (United States)

    2013-01-22

    ... COMMISSION PPL Bell Bend, LLC; Combined License Application for Bell Bend Nuclear Power Plant; Exemption 1.0... Approvals for Nuclear Power Plants.'' This reactor is to be identified as Bell Bend Nuclear Power Plant... (RCOL) application for UniStar's Calvert Cliffs Nuclear Power Plant, Unit 3 (CCNPP3). The......

  13. 76 FR 81992 - PPL Bell Bend, LLC; Combined License Application for Bell Bend Nuclear Power Plant; Exemption

    Science.gov (United States)

    2011-12-29

    ... COMMISSION PPL Bell Bend, LLC; Combined License Application for Bell Bend Nuclear Power Plant; Exemption 1.0..., Certifications, and Approvals for Nuclear Power Plants.'' This reactor is to be identified as Bell Bend Nuclear Power Plant (BBNPP), in Salem County, Pennsylvania. The BBNPP COL application incorporates by...

  14. Tunable waveguide bends with graphene-based anisotropic metamaterials

    KAUST Repository

    Chen, Zhao-xian

    2016-01-15

    We design tunable waveguide bends filled with graphene-based anisotropic metamaterials to achieve a nearly perfect bending effect. The anisotropic properties of the metamaterials can be described by the effective medium theory. The nearly perfect bending effect is demonstrated by finite element simulations of various structures with different bending curvatures and shapes. This effect is attributed to zero effective permittivity along the direction of propagation and matched effective impedance at the interfaces between the bending part and the dielectric waveguides. We envisage that the design will be applicable in the far-infrared and terahertz frequency ranges owing to the tunable dielectric responses of graphene.

  15. Permanent bending and alignment of ZnO nanowires.

    Science.gov (United States)

    Borschel, Christian; Spindler, Susann; Lerose, Damiana; Bochmann, Arne; Christiansen, Silke H; Nietzsche, Sandor; Oertel, Michael; Ronning, Carsten

    2011-05-06

    Ion beams can be used to permanently bend and re-align nanowires after growth. We have irradiated ZnO nanowires with energetic ions, achieving bending and alignment in different directions. Not only the bending of single nanowires is studied in detail, but also the simultaneous alignment of large ensembles of ZnO nanowires. Computer simulations reveal how the bending is initiated by ion beam induced damage. Detailed structural characterization identifies dislocations to relax stresses and make the bending and alignment permanent, even surviving annealing procedures.

  16. Permanent bending and alignment of ZnO nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Borschel, Christian; Spindler, Susann; Oertel, Michael; Ronning, Carsten [Institut fuer Festkoerperphysik, Friedrich-Schiller-Universitaet Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Lerose, Damiana [MPI fuer Mikrostrukturphysik, Weinberg 2, 06120 Halle/Saale (Germany); Institut fuer Photonische Technologien, Albert-Einstein-Strasse 9, 07745 Jena (Germany); Bochmann, Arne [Institut fuer Photonische Technologien, Albert-Einstein-Strasse 9, 07745 Jena (Germany); Christiansen, Silke H. [Institut fuer Photonische Technologien, Albert-Einstein-Strasse 9, 07745 Jena (Germany); MPI fuer die Physik des Lichts, Guenther-Scharowsky-Str. 1, 91058 Erlangen (Germany); Nietzsche, Sandor [Zentrum fuer Elektronenmikroskopie, Friedrich-Schiller-Universitaet Jena, Ziegelmuehlenweg 1, 07743 Jena (Germany)

    2011-07-01

    Ion beams can be used to bend or re-align nanowires permanently, after they have been grown. We have irradiated ZnO nanowires with ions of different species and energy, achieving bending and alignment in various directions. We study the bending of single nanowires as well as the simultaneous alignment of large ensembles of ZnO nanowires in detail. Computer simulations show that the bending is initiated by ion beam induced damage. Dislocations are identified to relax stresses and make the bending and alignment permanent and resistant against annealing procedures.

  17. Tunable waveguide bends with graphene-based anisotropic metamaterials

    Science.gov (United States)

    Chen, Zhao-xian; Chen, Ze-guo; Ming, Yang; Wu, Ying; Lu, Yan-qing

    2016-02-01

    We design tunable waveguide bends filled with graphene-based anisotropic metamaterials to achieve a nearly perfect bending effect. The anisotropic properties of the metamaterials can be described by the effective medium theory. The nearly perfect bending effect is demonstrated by finite element simulations of various structures with different bending curvatures and shapes. This effect is attributed to zero effective permittivity along the direction of propagation and matched effective impedance at the interfaces between the bending part and the dielectric waveguides. We envisage that the design will be applicable in the far-infrared and terahertz frequency ranges owing to the tunable dielectric responses of graphene.

  18. Parameter prediction in laser bending of aluminum alloy sheet

    Institute of Scientific and Technical Information of China (English)

    Xuyue WANG; Weixing XU; Hua CHEN; Jinsong WANG

    2008-01-01

    Based on the basic platform of BP neural net-works, a BP network model is established to predict the bending angle in the laser bending process of an aluminum alloy sheet (1-2 mm in thickness) and to optimize laser bending parameters for bending control. The sample experimental data is used to train the BP network. The nonlinear regularities of sample data are fitted through the trained BP network; the predicted results include laser bending angles and parameters. Experimental results indi-cate that the prediction allowance is controlled less than 5%-8% and can provide a theoretical and experimental basis for industry purpose.

  19. Recent developments in bend-insensitive and ultra-bend-insensitive fibers

    Science.gov (United States)

    Boivin, David; de Montmorillon, Louis-Anne; Provost, Lionel; Montaigne, Nelly; Gooijer, Frans; Aldea, Eugen; Jensma, Jaap; Sillard, Pierre

    2010-02-01

    Designed to overcome the limitations in case of extreme bending conditions, Bend- and Ultra-Bend-Insensitive Fibers (BIFs and UBIFs) appear as ideal solutions for use in FTTH networks and in components, pigtails or patch-cords for ever demanding applications such as military or sensing. Recently, however, questions have been raised concerning the Multi-Path-Interference (MPI) levels in these fibers. Indeed, they are potentially subject to interferences between the fundamental mode and the higher-order mode that is also bend resistant. This MPI is generated because of discrete discontinuities such as staples, bends and splices/connections that occur on distance scales that become comparable to the laser coherent length. In this paper, we will demonstrate the high MPI tolerance of all-solid single-trench-assisted BIFs and UBIFs. We will present the first comprehensive study combining theoretical and experimental points of view to quantify the impact of fusion splices on coherent MPI. To be complete, results for mechanical splices will also be reported. Finally, we will show how the single-trench- assisted concept combined with the versatile PCVD process allows to tightly control the distributions of fibers characteristics. Such controls are needed to massively produce BIFs and to meet the more stringent specifications of the UBIFs.

  20. Standard test methods for bend testing of material for ductility

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 These test methods cover bend testing for ductility of materials. Included in the procedures are four conditions of constraint on the bent portion of the specimen; a guided-bend test using a mandrel or plunger of defined dimensions to force the mid-length of the specimen between two supports separated by a defined space; a semi-guided bend test in which the specimen is bent, while in contact with a mandrel, through a specified angle or to a specified inside radius (r) of curvature, measured while under the bending force; a free-bend test in which the ends of the specimen are brought toward each other, but in which no transverse force is applied to the bend itself and there is no contact of the concave inside surface of the bend with other material; a bend and flatten test, in which a transverse force is applied to the bend such that the legs make contact with each other over the length of the specimen. 1.2 After bending, the convex surface of the bend is examined for evidence of a crack or surface irregu...

  1. A study on springback of bending linear flow split profiles

    Science.gov (United States)

    Mahajan, P.; Taplick, C.; Özel, M.; Groche, P.

    2016-11-01

    The bending of linear flow split profiles made up of high strength materials involves high bending loads leading to high springback and geometrical defects. In addition, the linear flow split profiles are made stronger due to the high plastic deformation applied by the process itself. The bending method proposed in this paper combines the linear flow splitting process with a movable bending tool. The aim of the research was to investigate the effect of superimposed stresses exerted by the linear flow splitting process on bending load and springback of the profile by using a finite element model. The latter was validated by means of experimental results. The results show that the bending loads and the springback were reduced by increasing the superposition of stress applied by the linear flow splitting process. The reduction in the bending loads leads to a reduction in the cross-sectional distortion. Furthermore, the springback was compensated by controlling the amount of superimposed stress.

  2. PREOPERATIVE ENDOSCOPIC MARKING OF UNPALPABLE COLONIC TUMORS

    Directory of Open Access Journals (Sweden)

    A. L. Goncharov

    2013-01-01

    Full Text Available The identification of small colon lesions is one of the major problems in laparoscopic colonic resection.Research objective: to develop a technique of visualization of small tumors of a colon by preoperative endoscopic marking of a tumor.Materials and methods. In one day prior to operation to the patient after bowel preparation the colonoscopy is carried out. In the planned point near tumor on antimesentery edge the submucous infiltration of marking solution (Micky Sharpz blue tattoo pigment, UK is made. The volume of entered solution of 1–3 ml. In only 5 months of use of a technique preoperative marking to 14 patients with small (the size of 1–3 cm malignant tumors of the left colon is performed.Results. The tattoo mark was well visualized by during operation at 13 of 14 patients. In all cases we recorded no complications. Time of operation with preoperative marking averaged 108 min, that is significantly less in comparison with average time of operation with an intra-operative colonoscopy – 155 min (р < 0.001.Conclusions. The first experience of preoperative endoscopic marking of non palpable small tumors of a colon is encouraging. Performance of a technique wasn't accompanied by complications and allowed to reduce significantly time of operation and to simplify conditions of performance of operation.

  3. Preoperative exercise training to improve postoperative outcomes

    NARCIS (Netherlands)

    Valkenet, K.

    2017-01-01

    It is common knowledge that better preoperative physical fitness is associated with better postoperative outcomes. However, as a result of aging of the population and improved surgical and anaesthesia techniques, the proportion of frail patients with decreased physical fitness levels undergoing majo

  4. Preoperational test report, primary ventilation system

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-11-04

    This represents a preoperational test report for Primary Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides vapor space filtered venting of tanks AY101, AY102, AZ101, AZ102. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  5. Preoperative evaluation : risk management and implementation aspects

    NARCIS (Netherlands)

    Klei, W.A. van

    2002-01-01

    In preoperative risk management the anesthesiologist uses diagnostic information to estimate the probability of outcomes and to decide on the anesthetic strategy in a particular patient. The aim of this thesis was explore to what extent simple patient characteristics, particularly obtained from

  6. Pre-operative fasting guidelines: an update

    DEFF Research Database (Denmark)

    Søreide, E; Eriksson, L I; Hirlekar, G

    2005-01-01

    Liberal pre-operative fasting routines have been implemented in most countries. In general, clear fluids are allowed up to 2 h before anaesthesia, and light meals up to 6 h. The same recommendations apply for children and pregnant women not in labour. In children...

  7. Preoperational test report, vent building ventilation system

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-11-04

    This represents a preoperational test report for Vent Building Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides Heating, Ventilation, and Air Conditioning (HVAC) for the W-030 Ventilation Building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  8. Preoperative and intraoperative continuous use of ...

    African Journals Online (AJOL)

    2016-09-13

    Sep 13, 2016 ... in clinics to improve patient safety and effectiveness with. Introduction ... and control group according to different use of drugs. The two ... Key words: Anesthesia, dexmedetomidine, effect, intervention, preoperative, recovery, remifentanil .... will lead to postoperative pain in patients and severe agitation after ...

  9. Preoperational test, vent building ventilation system

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T., Westinghouse Hanford

    1996-08-20

    Preoperational Test Procedure for Vent Building Ventilation System, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The Vent Building ventilation system provides ventilation, heating, cooling, and zone confinement control for the W-030 Project Vent Building. The tests verify correct System operation and correct indications displayed by the central Monitor and Control system.

  10. Preoperative evaluation : risk management and implementation aspects

    NARCIS (Netherlands)

    Klei, W.A. van

    2002-01-01

    In preoperative risk management the anesthesiologist uses diagnostic information to estimate the probability of outcomes and to decide on the anesthetic strategy in a particular patient. The aim of this thesis was explore to what extent simple patient characteristics, particularly obtained from preo

  11. Cricket antennae shorten when bending (Acheta domesticus L.

    Directory of Open Access Journals (Sweden)

    Catherine eLoudon

    2014-06-01

    Full Text Available Insect antennae are important mechanosensory and chemosensory organs. Insect appendages, such as antennae, are encased in a cuticular exoskeleton and are thought to bend only between segments or subsegments where the cuticle is thinner, more flexible, or bent into a fold. There is a growing appreciation of the dominating influence of folds in the mechanical behavior of a structure, and the bending of cricket antennae was considered in this context. Antennae will bend or deflect in response to forces, and the resulting bending behavior will affect the sensory input of the antennae. In some cricket antennae, such as in those of Acheta domesticus, there are a large number (>100 of subsegments (flagellomeres that vary in their length. We evaluated whether these antennae bend only at the joints between flagellomeres, which has always been assumed but not tested. In addition we questioned whether an antenna undergoes a length change as it bends, which would result from some patterns of joint deformation. Measurements using light microscopy and SEM were conducted on both male and female adult crickets (Acheta domesticus with bending in four different directions: dorsal, ventral, medial and lateral. Bending occurred only at the joints between flagellomeres, and antennae shortened a comparable amount during bending, regardless of sex or bending direction. The cuticular folds separating antennal flagellomeres are not very deep, and therefore as an antenna bends, the convex side (in tension does not have a lot of slack cuticle to unfold and does not lengthen during bending. Simultaneously on the other side of the antenna, on the concave side in compression, there is an increasing overlap in the folded cuticle of the joints during bending. Antennal shortening during bending would prevent stretching of antennal nerves and may promote hemolymph exchange between the antenna and head.

  12. Investigation of load effect on macro-bend losses for an SMS fiber structure with a small bend radius

    Science.gov (United States)

    Rahmah, Fitri; Sekartedjo, Sekartedjo; Hatta, Agus Muhamad

    2016-11-01

    Modelling of load effect on macro-bend losses for a singlemode-multimode-singlemode (SMS) fiber structure with small bend radius is presented. Load effect on macro-bend losses for the SMS fiber structure placed between two high-density polyethylene (HDPE) boards are investigated theoretically and experimentally. A model on macro-bend losses for SMS fiber structure is constructed by using the light transmission formula in a straight SMS fiber structure and taking into account the effective number of guided modes due to the macrobending. In the experimental, a mandrel with a diameter of 0.8 mm is used to induce the bend. When the loads are applied on the system, the mandrel will affect the bend losses for the SMS fiber structure. It is shown numerically and experimentally that the bend-loss of SMS fiber structure strongly depends on the applied loads and the multimode fiber (MMF) lengths.

  13. Light bending in $f(T)$ gravity

    CERN Document Server

    Ruggiero, Matteo Luca

    2016-01-01

    In the framework of $f(T)$ gravity, we focus on a weak-field and spherically symmetric solution for the Lagrangian $f(T)=T+\\alpha T^{2}$, where $\\alpha$ is a small constant which parameterizes the departure from General Relativity. In particular, we study the propagation of light and obtain the correction to the general relativistic bending angle. Moreover, we discuss the impact of this correction on some gravitational lensing observables, and evaluate the possibility of constraining the theory parameter $\\alpha$ by means of observations.

  14. Anomalous bending effect in photonic crystal fibers.

    Science.gov (United States)

    Tu, Haohua; Jiang, Zhi; Marks, Daniel L; Boppart, Stephen A

    2008-04-14

    An unexpected transmission loss up to 50% occurs to intense femtosecond pulses propagating along an endlessly single-mode photonic crystal fiber over a length of 1 m. A specific leaky-fiber mode gains amplification along the fiber at the expense of the fundamental fiber mode through stimulated four-wave mixing and Raman scattering, leading to this transmission loss. Bending near the fiber entrance dissipates the propagating seed of this leaky mode, preventing the leaky mode amplification and therefore enhancing the transmission of these pulses.

  15. Thermoelastic bending of locally heated orthotropic shells

    Science.gov (United States)

    Shevchenko, V. P.; Gol'tsev, A. S.

    2007-03-01

    The thermoelastic bending of locally heated orthotropic shells is studied using the classical theory of thermoelasticity of thin shallow orthotropic shells and the method of fundamental solutions. Linear distribution of temperature over thickness and the Newton's law of cooling are assumed. Numerical analysis is carried out for orthotropic shells of arbitrary Gaussian curvature made of a strongly anisotropic material. The behavior of thermal forces and moments near the zone of local heating is studied for two areas of thermal effect: along a coordinate axis and along a circle of unit radius. Generalized conclusions are drawn

  16. Extension versus Bending for Continuum Robots

    Directory of Open Access Journals (Sweden)

    George Grimes

    2008-11-01

    Full Text Available In this paper, we analyze the capabilities of a novel class of continuous-backbone ("continuum" robots. These robots are inspired by biological "trunks, and tentacles". However, the capabilities of established continuum robot designs, which feature controlled bending but not extension, fall short of those of their biological counterparts. In this paper, we argue that the addition of controlled extension provides dual and complementary functionality, and correspondingly enhanced performance, in continuum robots. We present an interval-based analysis to show how the inclusion of controllable extension significantly enhances the workspace and capabilities of continuum robots.

  17. Wooden Model of Wide AA Bending Magnet

    CERN Multimedia

    1978-01-01

    The very particular lattice of the AA required 2 types of dipoles (bending magnets: BLG, long and narrow; BST, short and wide). A wide one had a steel length of 2.71 m, a "good field" width of 0.564 m, and a weight of about 75 t. A wooden model was build in 1978, to gain dimensional experience. Here, Peter Zettwoch, one of the largest men at CERN at that time, is putting a hand in the mouth of the wooden BST monster.

  18. Clinical bending of nickel titanium wires

    Directory of Open Access Journals (Sweden)

    Stephen Chain

    2015-01-01

    Full Text Available Since the evolution and the involvement of Nickel Titanium wires in the field of Orthodontics. The treatment plan has evolved with the use of low force Nickel Titanium wires. Because of their high springback, low stiffness, they are the key initial wires in leveling and alignment but have poor formability. Since poor formability limits its ability to create variable arch forms thus; limits the form of treatment. We have devised a method to bend the Nickel Titanium wires to help in our inventory but also customized the wire according to the treatment.

  19. Preoperative staging of perforated diverticulitis by computed tomography scanning

    NARCIS (Netherlands)

    M.P.M. Gielens; I.M. Mulder (Irene); E. van der Harst (Erwin); M.P. Gosselink (Martijn Pieter); K.J. Kraal; H.T. Teng; J.F. Lange (Johan); J. Vermeulen (Jefrey)

    2012-01-01

    textabstractBackground: Treatment of perforated diverticulitis depends on disease severity classified according to Hinchey's preoperative classification. This study assessed the accuracy of preoperative staging of perforated diverticulitis by computerized tomography (CT) scanning. Methods: All patie

  20. The Amsterdam Preoperative Anxiety and Information Scale (APAIS)

    National Research Council Canada - National Science Library

    Moerman, N; Dam, van, F.S.A.M; Muller, M.J; Oosting, H

    1996-01-01

    ... phase.During routine preoperative screening, 320 patients were asked to assess their anxiety and information requirement on a six-item questionnaire, the Amsterdam Preoperative Anxiety and Information Scale (APAIS...

  1. [Preoperative assessment of patients with diabetes mellitus].

    Science.gov (United States)

    Takeda, Kiyoshi

    2010-07-01

    The perioperative morbidity of diabetic patients is related to preoperative end-organ damage. Due to the microvascular pathology, autonomic neuropathy is common and cardiovascular abnormalities such as hypertension, painless myocardial ischemia, and orthostatic hypotension may predispose patients to perioperative cardiovascular instability. Autonomic dysfunction also contributes to delayed gastric emptying, and preoperative administration of a histamine antagonist and a gastric emptying agent is needed. Chronic hyperglycemia leads to glycosylation of tissue proteins and the accumulation of abnormal collagen can cause stiff joint syndrome resulting in difficult tracheal intubation. The primary goal of pre and intraoperative blood glucose control is to avoid hypoglycemia and ketosis. Moreover, the tight glycemic control has been reported to improve survival in critically ill patients who were treated in the intensive care unit.

  2. Preoperatively diagnosed mucocele of the appendix.

    Science.gov (United States)

    Rojnoveanu, Gh; Ghidirim, Gh; Mishin, I; Vozian, M; Mishina, A

    2014-01-01

    Mucocele of the appendix is an infrequent entity, characterized by distension of the lumen due to accumulation of mucoid substance and is rarely diagnosed preoperatively. If untreated, mucocele may rupture producing a potentially fatal entity known as pseudomyxoma peritonei. The type of surgical treatment is related to the dimensions and the histology of the mucocele. Appendectomy is used for simple mucocele or for cystadenoma. Right hemi-colectomy is recommended for cystadeno carcinoma. In this paper, we report a case of an asymptomatic 37-year-old woman in whom mucocele was found on a routine ultrasound examination and preoperative computed tomography scan. Surgery revealed a big appendix measuring 84 mm in length and 40 mm in diameter. The final pathologic diagnosis was simple mucocele. Celsius.

  3. Preoperative Alcohol Consumption and Postoperative Complications

    DEFF Research Database (Denmark)

    Eliasen, Marie; Grønkjær, Marie; Skov-Ettrup, Lise Skrubbeltrang

    2013-01-01

    .30-2.49), prolonged stay at the hospital (RR = 1.24; 95% CI: 1.18-1.31), and admission to intensive care unit (RR = 1.29; 95% CI: 1.03-1.61). Clearly defined high alcohol consumption was associated with increased risk of postoperative mortality (RR = 2.68; 95% CI: 1.50-4.78). Low to moderate preoperative alcohol...... complications, prolonged stay at the hospital, and admission to intensive care unit....

  4. Bending strain tolerance of MgB2 superconducting wires

    Science.gov (United States)

    Kováč, P.; Hušek, I.; Melišek, T.; Kulich, M.; Kopera, L.

    2016-04-01

    This work describes the strain tolerance of MgB2 superconductors subjected to variable bending stresses. Bending of MgB2 wire was done at room temperature in different modes: (i) direct bending of straight annealed samples to variable diameters and by (ii) indirect bending by straightening of bent and annealed samples. I c-bending strain characteristics of samples made by in situ PIT and by the internal magnesium diffusion (IMD) process were measured at 4.2 K. The results show a good agreement between the direct and indirect bending mode, which allows easier estimation of limits important for the winding process of MgB2 superconductors with brittle filaments. A comparison of MgB2 wires made by in situ PIT and IMD processes showed improved strain tolerance for IMD due to better grain connectivity the low annealing temperature, which does not appear to reduce the mechanical strength of sheath material.

  5. Flexible bending of aluminum profiles with polyurethane pad

    Institute of Scientific and Technical Information of China (English)

    HE Zhu-bin; LIU Gang; WANG Zhong-ren

    2006-01-01

    The high flexibility of profile bending with hyperelastic pad enables it to be a promising method for small lot or single part production, especially for space frame and roof-rail parts in automotive and aerospace industries. Bending of two aluminum profiles with different sections was carried out to investigate the effect of main process parameters on the bending process. Results show that the shape of the cross-section and its relative thickness and section modulus in bending are the main factors that determine the bending properties of the profiles. Roller stroke, properties of polyurethane pad and constraints on profiles are key factors that determine the bending radius and section deformation of bent profiles. Failures and quality problems met in experiments were also analyzed.

  6. Reduction Bending of Thin Crystalline Silicon Solar Cells

    Institute of Scientific and Technical Information of China (English)

    SHEN Lan-xian; LIU Zu-ming; LIAO Hua; TU Jie-lei; DENG Shu-kang

    2009-01-01

    Reported are the results of reduction the bending of thin crystalline silicon solar ceils after printing and sintering of back electrode by changing the back electrode paste and adjusting the screen printing parameters without effecting the electrical properties of the cell. Theory and experiments showed that the bending of the cell is changed with its thickness of suhstrate, the thinner cell, the more serious bending. The bending of the cell is decreased with the thickness decrease of the back contact paste. The substrate with the thickness of 190μm printing with sheet aluminum paste shows a relatively lower bend compared with that of the substrate printing with ordinary aluminum paste, and the minimum bend is 0.55 mm which is reduced by52%.

  7. Preoperative Arterial Interventional Chemotherapy on Cervical Cancer

    Institute of Scientific and Technical Information of China (English)

    WANG Hui; LING HU-Hua; TANG Liang-dan; ZHANG Xing-hua

    2008-01-01

    Objective:To discuss the therapeutic effect of preoperative interventional chemotherapy on cervical cancer.Methods:Preoperative interventional chemotherapy by femoral intubation was performed in 25 patients with bulky cervical cancer.The patients received bleomycin 45 mg and cisplatin or oxaliplatin 80 mg/m2.Results:25 cases(including 8 cases with stage Ⅰ and 17 cases with stage Ⅱ)received one or two courses of preoperative interventional chemotherapy.The size of the focal lesions was decreased greatly and radical hysterectomy and lymphadenectomy were performed successfully in all the patients.All of the specimens were sent for pathological examination.Lymphocyte infiltration was found more obvious in the cancer tissues as compared with their counterpart before treatment.As a result,relevant vaginal bleeding was stopped completely shortly after the treatment.Conclusion:Arterial interventional chemotherapy was proved to reduce the local size of cervical cancer and thus control the hemorrhage efficiently.The patients with cervical cancer can receive radical hysterectomy therapy after the interventional chemotherapy.

  8. Citrus aurantium blossom and preoperative anxiety.

    Science.gov (United States)

    Akhlaghi, Mahmood; Shabanian, Gholamreza; Rafieian-Kopaei, Mahmoud; Parvin, Neda; Saadat, Mitra; Akhlaghi, Mohsen

    2011-01-01

    Reducing anxiety is very important before operation. Preoperative visit and use of premedication are popular methods to achieve this goal, but the role of anxiolytic premedication remains unclear and postoperative side-effects may result from routine premedication. Citrus aurantium is used as an alternative medicine in some countries to treat anxiety, and recently the anxiolytic role of this medicinal plant was established in an animal model study. The aim of this study was to assess the anxiolytic effect of Citrus aurantium blossomon preoperative anxiety. We studied 60 ASA I patients undergoing minor operation. In a randomized double-blind design, two groups of 30 patients received one of the following oral premedication two hours before induction of anesthesia: 1) Citrus aurantium blossom distillate 1mL.kg(-1) (C-group); 2) Saline solution 1mL.kg(-1) as placebo (P-group). Anxiety was measured before and after premedication using the Spielberger state-trait anxiety inventory (STAI-state) and the Amsterdam preoperative anxiety and information scale (APAIS) before operation. After premedication, both the STAI-state and the APAIS scales were decreased in C-group (ppreoperative anxiety before minor operation. Copyright © 2011 Elsevier Editora Ltda. All rights reserved.

  9. Preoperative imaging diagnosis of carotid body tumors.

    Science.gov (United States)

    Pacheco-Ojeda, Luis A; Martínez-Viteri, Miguel A

    2010-01-01

    Carotid body tumors (CBTs) are relatively frequent lesions encountered at high altitudes, such in as the Andean Mountains. A correct preoperative diagnosis is essential for surgical planning and performance. For this reason, we have reviewed the evolution of our experience in the imaging diagnosis of these tumors. Between 1980 and June 2008, 160 CBTs were diagnosed. A total of 138 tumors were operated on, 4 are waiting for surgery, and 18 were not operated on because of age, medical conditions, or patient refusal. We have reviewed retrospectively the modalities of imaging diagnosis in our patients who underwent operation. Among the 138 tumors operated on, a correct preoperative diagnosis was done in 127 cases (92%). The preoperative diagnosis of the remaining 11 patients was unspecified benign tumor for 6 patients and neck lymph node for 5 patients. The imaging methods performed by different radiologists were conventional ultrasound, color Doppler ultrasound, carotid conventional angiography (CA), axial tomography, magnetic resonance and magnetic resonance angiography, and computed tomographic angiography (CTA). Most patients had more than one image study. Review of radiologist reports revealed a correct diagnosis in all carotid CA, magnetic resonance studies, and CTA. Additionally, CTA appeared to be a valuable method to predict the Shamblin group. Clinical suspicion and current image techniques permit a correct diagnosis in practically all cases of CBT.

  10. Implications of preoperative hypoalbuminemia in colorectal surgery

    Institute of Scientific and Technical Information of China (English)

    Adam Truong; Mark H Hanna; Zhobin Moghadamyeghaneh; Michael J Stamos

    2016-01-01

    Serum albumin has traditionally been used as a quantitative measure of a patient’s nutritional status because of its availability and low cost. While malnutrition has a clear definition within both the American and European Societies for Parenteral and Enteral Nutrition clinical guidelines, individual surgeons often determine nutritional status anecdotally. Preoperative albumin level has been shown to be the best predictor of mortality after colorectal cancer surgery. Specifically in colorectal surgical patients, hypoalbuminemia significantly increases the length of hospital stay, rates of surgical site infections, enterocutaneous fistula risk, and deep vein thrombosis formation. The delay of surgical procedures to allow for preoperative correction of albumin levels in hypoalbuminemic patients has been shown to improve the morbidity and mortality in patients with severe nutritional risk. The importance of preoperative albumin levels and the patient’s chronic inflammatory state on the postoperative morbidity and mortality has led to the development of a variety of surgical scoring systems to predict outcomes efficiently. This review attempts to provide a systematic overview of albumin and its role and implications in colorectal surgery.

  11. INVESTIGATION INTO THE SPRINGBACK OF PIPE BENDING USING INDUCTION HEATING

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Stresses and deformation states of pipe bending are investigated under loading or unloading with various pipe materials, size, bending radius and deformation temperature. A theorem of springback of large diameter pipe bending is presented. The experiments are carried out with pipe materials of 20, 10CrMo910 and 12Cr1MoV steel. Results of computations are in good agreement with experiments.

  12. BEND3 mediates transcriptional repression and heterochromatin organization.

    Science.gov (United States)

    Khan, Abid; Prasanth, Supriya G

    2015-01-01

    Transcription repression plays a central role in gene regulation. Transcription repressors utilize diverse strategies to mediate transcriptional repression. We have recently demonstrated that BEND3 (BANP, E5R and Nac1 domain) protein represses rDNA transcription by stabilizing a NoRC component. We discuss the role of BEND3 as a global regulator of gene expression and propose a model whereby BEND3 associates with chromatin remodeling complexes to modulate gene expression and heterochromatin organization.

  13. Multiple-cladding fibers with reduced bend loss

    Science.gov (United States)

    Tomljenovic-Hanic, Snjezana; Bulla, Douglas A. P.; Ankiewicz, Adrian; Love, John D.; Bailey, Ron

    2007-04-01

    We demonstrate that a highly bend-resistant fiber can be realized. It is shown theoretically that, by introducing both depressed and elevated rings into the cladding, bending loss can be reduced significantly. A fiber based on this design has been fabricated and characterized as a first step toward achieving this goal. The results show that a multiple-cladding fiber is highly bend resistant when compared with the standard telecom single-mode fiber.

  14. 49 CFR 192.315 - Wrinkle bends in steel pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Wrinkle bends in steel pipe. 192.315 Section 192... Transmission Lines and Mains § 192.315 Wrinkle bends in steel pipe. (a) A wrinkle bend may not be made on steel pipe to be operated at a pressure that produces a hoop stress of 30 percent, or more, of SMYS. (b) Each...

  15. Bending response of single layer MoS2.

    Science.gov (United States)

    Xiong, Si; Cao, Guoxin

    2016-03-11

    Using molecular mechanics (or dynamics) simulations, three different approaches, including the targeted molecular mechanics, four-point bending and nanotube methods, are employed to investigate the bending response of single layer MoS2 (SLMoS2), among which four-point bending is the most accurate approach to determine the bending stiffness according to the continuum theory. It is found that when the bending curvature radius is large enough (e.g. >4 nm), three approaches will give the same bending stiffness of SLMoS2 and the bending behavior is isotropic for SLMoS2, whereas the nanotube method with small tubes (e.g. bending stiffness. Compared with the reported result from the MoS2 nanotube calculated by density functional theory, the revised Stillinger-Weber (SW) and reactive empirical bond-order (REBO) potentials can give the reasonable bending stiffness of SLMoS2 (8.7-13.4 eV) as well as the effective deformed conformation. In addition, since the Mo-S bond deformation of SLMoS2 under bending is similar to that under in-plane tension/compression, the continuum bending theory can quite accurately predict the bending stiffness of SLMoS2 if a reasonable thickness of SLMoS2 is given. For SLMoS2, the reasonable thickness should be larger than the distance between its two S atomic planes and lower than the distance between two Mo atomic planes of bulk MoS2 crystal, e.g. 0.375-0.445 nm.

  16. Bending response of single layer MoS2

    Science.gov (United States)

    Xiong, Si; Cao, Guoxin

    2016-03-01

    Using molecular mechanics (or dynamics) simulations, three different approaches, including the targeted molecular mechanics, four-point bending and nanotube methods, are employed to investigate the bending response of single layer MoS2 (SLMoS2), among which four-point bending is the most accurate approach to determine the bending stiffness according to the continuum theory. It is found that when the bending curvature radius is large enough (e.g. >4 nm), three approaches will give the same bending stiffness of SLMoS2 and the bending behavior is isotropic for SLMoS2, whereas the nanotube method with small tubes (e.g. <4 nm) cannot give the correct bending stiffness. Compared with the reported result from the MoS2 nanotube calculated by density functional theory, the revised Stillinger-Weber (SW) and reactive empirical bond-order (REBO) potentials can give the reasonable bending stiffness of SLMoS2 (8.7-13.4 eV) as well as the effective deformed conformation. In addition, since the Mo-S bond deformation of SLMoS2 under bending is similar to that under in-plane tension/compression, the continuum bending theory can quite accurately predict the bending stiffness of SLMoS2 if a reasonable thickness of SLMoS2 is given. For SLMoS2, the reasonable thickness should be larger than the distance between its two S atomic planes and lower than the distance between two Mo atomic planes of bulk MoS2 crystal, e.g. 0.375-0.445 nm.

  17. Hot bending with a fiber coupled solid state laser

    Science.gov (United States)

    Bammer, F.; Schumi, T.; Schuöcker, D.

    2010-09-01

    For bending of brittle materials it is necessary to heat up the forming zone. This can be done with a fiber coupled solid state laser, whose beam is evenly distributed on the bending line with a beam splitter installed in the lower tool (die) of a bending press. With polarization optics the laser beam is divided there into partial beams that are evenly distributed on the bending line with lenses and prisms. A setup for a bending length of 200mm heated by a fiber-coupled 3kW Nd:YAG-laser shows the feasibility of the concept. Successful operation was shown for the Mg-alloy AZ31, which breaks during forming at room temperature, but can be well formed at temperatures in the range of 200-300°C. Other materials benefiting from this method are Ti-alloys, high-strength-Al-alloys, and high-strength-steels. Typical heating times are in the range of up to 5s and much of the heat input is generated during the bending operation where the laser continues to work. Laser Assisted Bending with a fiber coupled solid state laser is a straightforward way to perform the bending of brittle materials in a process as simple as cold bending.

  18. A preliminary bending fatigue spectrum for steel monostrand cables

    DEFF Research Database (Denmark)

    Winkler, Jan; Fischer, Gregor; Georgakis, Christos T.;

    2011-01-01

    This paper presents the results of the experimental study on the bending fatigue resistance of high-strength steel monostrand cables. From the conducted fatigue tests in the high-stress, low-cycle region, a preliminary bending fatigue spectrum is derived for the estimation of monostrand cable...... service life expectancy. The presented preliminary bending fatigue spectrum of high-strength monostrands is currently unavailable in the published literature. The presented results provide relevant information on the bending mechanism and fatigue characteristics of monostrand steel cables in tension...

  19. PERMEABILITY OF SALTSTONE MEASUREMENT BY BEAM BENDING

    Energy Technology Data Exchange (ETDEWEB)

    Harbour, J; Tommy Edwards, T; Vickie Williams, V

    2008-01-30

    One of the goals of the Saltstone variability study is to identify (and, quantify the impact of) the operational and compositional variables that control or influence the important processing and performance properties of Saltstone mixes. A performance property for Saltstone mixes that is important but not routinely measured is the liquid permeability or saturated hydraulic conductivity of the cured Saltstone mix. The value for the saturated hydraulic conductivity is an input into the Performance Assessment for the SRS Z-Area vaults. Therefore, it is important to have a method available that allows for an accurate and reproducible measurement of permeability quickly and inexpensively. One such method that could potentially meet these requirements for the measurement of saturated hydraulic conductivity is the technique of beam bending, developed by Professor George Scherer at Princeton University. In order to determine the feasibility of this technique for Saltstone mixes, a summer student, David Feliciano, was hired to work at Princeton under the direction of George Scherer. This report details the results of this study which demonstrated the feasibility and applicability of the beam bending method to measurement of permeability of Saltstone samples. This research effort used samples made at Princeton from a Modular Caustic side solvent extraction Unit based simulant (MCU) and premix at a water to premix ratio of 0.60. The saturated hydraulic conductivities for these mixes were measured by the beam bending technique and the values determined were of the order of 1.4 to 3.4 x 10{sup -9} cm/sec. These values of hydraulic conductivity are consistent with independently measured values of this property on similar MCU based mixes by Dixon and Phifer. These values are also consistent with the hydraulic conductivity of a generic Saltstone mix measured by Langton in 1985. The high water to premix ratio used for Saltstone along with the relatively low degree of hydration for

  20. Deriving position of inverse bending roll by experiment and analysis : High precision roll bending of titanium alloy wire for glasses frame

    OpenAIRE

    佐々木, 善教; 大津, 雅亮; 松村, 正三; 森下, 和幸; 田中, 大樹; 八木, 秀樹; 関根, 雄一郎; 浅川, 基男

    2015-01-01

    In forming of glasses frame, bending and inverse bending of rim wires with 4 rolls are usually employed. Only an inverse bending roll, the 4th roll, can change the position to control the curvature of the rim wire. A deriving method of inverse bending roll position is proposed in this study. The proposed method requires not the computational simulations but only some simple steady inverse bending experiments to obtain a relationship between inverse bending roll position and bent curvature whi...

  1. Iron therapy for pre-operative anaemia.

    Science.gov (United States)

    Ng, Oliver; Keeler, Barrie D; Mishra, Amitabh; Simpson, Alastair; Neal, Keith; Brookes, Matthew J; Acheson, Austin G

    2015-12-22

    Pre-operative anaemia is common and occurs in up to 76% of patients. It is associated with increased peri-operative allogeneic blood transfusions, longer hospital lengths of stay and increased morbidity and mortality. Iron deficiency is one of the most common causes of this anaemia. Oral iron therapy has traditionally been used to treat anaemia but newer, safer parenteral iron preparations have been shown to be more effective in other conditions such as inflammatory bowel disease, chronic heart failure and post-partum haemorrhage. A limited number of studies look at iron therapy for the treatment of pre-operative anaemia. The aim of this Cochrane review is to summarise the evidence for use of iron supplementation, both enteral and parenteral, for the management of pre-operative anaemia. The objective of this review is to evaluate the effects of pre-operative iron therapy (enteral or parenteral) in reducing the need for allogeneic blood transfusions in anaemic patients undergoing surgery. We ran the search on 25 March 2015. We searched the Cochrane Injuries Group's Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), Ovid MEDLINE(R), Ovid MEDLINE(R) In-Process & Other Non-Indexed Citations, Ovid MEDLINE(R) Daily and Ovid OLDMEDLINE(R), EMBASE Classic and EMBASE (Ovid), CINAHL Plus (EBSCO), PubMed, clinical trials registries, conference abstracts, and we screened reference lists. We included all randomised controlled trials (RCTs) which compared pre-operative iron monotherapy to placebo, no treatment, standard of care or another form of iron therapy for anaemic adults undergoing surgery. Anaemia was defined by haemoglobin values less than 13 g/dL for males and 12 g/dL for non-pregnant females. Data were collected by two authors on the proportion of patients who receive a blood transfusion, amount of blood transfused per patient (units) and haemoglobin measured as continuous variables at pre-determined time-points: pre

  2. On the gravitational seesaw and light bending

    CERN Document Server

    Accioly, Antonio; Shapiro, Ilya L

    2016-01-01

    Local gravitational theories with more than four derivatives are superrenormalizable, and also may be unitary in the Lee-Wick sense. It makes sense to study low-energy properties of these theories, e.g., identify observables which might be useful for experimental detection of higher derivatives. Using an analogy with neutrino Physics, we explore the possibility of a gravitational seesaw mechanism, in which several dimensional parameters of the same order of magnitude produce a hierarchy in the masses of propagating particles and make a relatively light degree of freedom detectable by frequency dependence in the gravitational light bending. It turns out that such a seesaw mechanism in the six- and more-derivative theories is unable to reduce the lightest mass more than in the simplest four-derivative model. Adding more derivatives can only make heavier masses even larger. This fact may be favorable for protecting the theory from instabilities, but makes experimental detection of higher derivatives more difficu...

  3. Secondary turbulent flow in an infinte bend

    DEFF Research Database (Denmark)

    Christensen, H. Bo; Gislason, Kjartan; Fredsøe, Jørgen

    1999-01-01

    The flow in an infinite circular bend is inverstigated in both the laminar and fully turbulent flow case, by use of laminar flow solver, a k-e turbulence model, and a fully Reynolds stress turbulence model. The topic of the analysis is to investigate whether a counter-rotating secondary flow cell...... is formed near the surface at the outer bank. This cell might help to stabilise the bank and hereby be an important factor for the morphology in a meandering river. In the laminar runs stability criterion related to a Dean number was estabilshed. In the simulations with the k-e model and the Reynolds stress...... model, the influence of the curvature ratio and cross section geometry on the vortex pattern is investigated. Furthermore, it is demonstrated that an-isotropy of turbulence plays an important role for the structure of flow pattern and existence of an extra flow cell....

  4. Design Study: ELENA Bending Magnet Prototype

    CERN Document Server

    Schoerling, D

    2013-01-01

    The ELENA bending magnet prototype shall prove that the proposed design meets the requirements set by the ELENA beam dynamics. The following points will be discussed in detail: (i) production process of a magnetic yoke diluted with stainless steel plates, (ii) the stability and repeatability of the field homogeneity of such a yoke over the full working range, (iii) choice of soft magnetic steel, (iv) hysteresis effects, (v) mechanical deformations, (vi) thermal insulation to intercept heat load from baking for activation of NEG coating in the vacuum chamber, (vii) end shim design. In order to verify these points the following measurements will be performed: (i) Hall probe scanning, (ii) integrated field homogeneity measurement (DC), (iii) integrated field homogeneity measurement (AC).

  5. Bend-insensitive fiber based vibration sensor

    Science.gov (United States)

    Xu, Yanping; Lu, Ping; Baset, Farhana; Bhardwaj, Vedula Ravi; Bao, Xiaoyi

    2014-05-01

    We report two novel fiber-optic vibration sensors based on standard telecom bend-insensitive fiber (BIF). A tapered BIF forming a fiber Mach-Zehnder interferometer could measure continuous and damped vibration from 1 Hz up to 500 kHz. An enclosed microcantilever is fabricated inside the BIF by chemical etching and fusion spliced with a readout singlemode fiber that exhibits a frequency range from 5 Hz to 10 kHz with high signal-to-noise ratio (SNR) up to 68 dB. The unique double cladding structure of the BIF ensures both sensors with advantages of compactness, high resistance to the external disturbance and stronger mechanical strength.

  6. Bending of pipes with inconel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Nachpitz, Leonardo; Menezes, Carlos Eduardo B.; Vieira, Carlos R. Tavares [Primus Processamento de Tubos S.A. (PROTUBO), Macae, RJ (Brazil)

    2009-07-01

    The high-frequency induction bending process, using API pipes coated with Inconel 625 reconciled to a mechanical transformation for a higher degree of resistance, was developed through a careful specification and control of the manufacturing parameters and inherent heat treatments. The effects of this technology were investigated by a qualification process consisting of a sequence of tests and acceptance criteria typically required by the offshore industry, and through the obtained results was proved the effectiveness of this entire manufacturing process, without causing interference in the properties and the quality of the inconel cladding, adding a gain of resistance to the base material, guaranteed by the requirements of the API 5L Standard. (author)

  7. A Study on Residual Stress of U-Bending Heat Transfer Tube using Rotary Draw Bending Processing

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Ok Gyu; Jang, Kye Hwan; Kim, Won Seok [BHI Co., Haman (Korea, Republic of); Ku, Tae Wan [Pusan National University, Busan (Korea, Republic of)

    2016-05-15

    The heat transfer tubes can be considered a kind of heat exchange boundary that is direct heat exchange from inside the steam generator. The heat transfer tubes of the steam generator have various bending radius. The heat transfer tubes have the U-shape and L-shape, depending on installed location and arrangement. The forming of the heat transfer tubes can be applied to process of rotary draw bending, roll bending, ram bending and etc. The rotary draw bending process is mainly used, when the bending radius is small. Recently, Alloy 600 or Alloy 690 tubes have been used as material for the heat transfer tubes of the steam generator. The purpose of this study is to evaluate the residual stress of the heat transfer row-1 tubes for deriving the remaining residual stress after U-Bending processing, as a primary study. In this study, the samples of U-Bending tube were made using Rotary Draw Bending Machine by Alloy690 straight tube. This study was measured Residual Stresses of the Row-1 Heat Transfer Tube in Steam Generator. The measurement methods are used two type of the analytical method (FEM) and experimental method (HDM). It was confirmed that the correlation of the measurement of the FEM and HDM methods. The FEM and HDM both methods showed compressive residual stresses. In numerical terms, the HDM is shown that higher value than the FEM.

  8. Coupled-Mode Flutter of Bending-Bending Type in Highly-Flexible Uniform Airfoils

    Science.gov (United States)

    Pourazarm, Pariya; Modarres-Sadeghi, Yahya

    2016-11-01

    We study the behavior of a highly flexible uniform airfoil placed in wind both numerically and experimentally. It is shown that for a non-rotating highly-flexible cantilevered airfoil, placed at very small angles of attack (less than 1 degree), the airfoil loses its stability by buckling. For slightly higher angles of attack (more than 1 degree) a coupled-mode flutter in which the first and the second flapwise modes coalesce toward a flutter mode is observed, and thus the observed flutter has a bending-bending nature. The flutter onset and frequency found experimentally matched the numerical predictions. If the same airfoil is forced to rotate about its fixed end, the static deflection decreases and the observed couple-mode flutter becomes of flapwise-torsional type, same as what has already been observed for flutter of rotating wind turbine blades. The support provided by the National Science Foundation, CBET-1437988, is greatly acknowledged.

  9. Bending the Curve: Sensitivity to Bending of Curved Paths and Application in Room-Scale VR.

    Science.gov (United States)

    Langbehn, Eike; Lubos, Paul; Bruder, Gerd; Steinicke, Frank

    2017-04-01

    Redirected walking (RDW) promises to allow near-natural walking in an infinitely large virtual environment (VE) by subtle manipulations of the virtual camera. Previous experiments analyzed the human sensitivity to RDW manipulations by focusing on the worst-case scenario, in which users walk perfectly straight ahead in the VE, whereas they are redirected on a circular path in the real world. The results showed that a physical radius of at least 22 meters is required for undetectable RDW. However, users do not always walk exactly straight in a VE. So far, it has not been investigated how much a physical path can be bent in situations in which users walk a virtual curved path instead of a straight one. Such curved walking paths can be often observed, for example, when users walk on virtual trails, through bent corridors, or when circling around obstacles. In such situations the question is not, whether or not the physical path can be bent, but how much the bending of the physical path may vary from the bending of the virtual path. In this article, we analyze this question and present redirection by means of bending gains that describe the discrepancy between the bending of curved paths in the real and virtual environment. Furthermore, we report the psychophysical experiments in which we analyzed the human sensitivity to these gains. The results reveal encouragingly wider detection thresholds than for straightforward walking. Based on our findings, we discuss the potential of curved walking and present a first approach to leverage bent paths in a way that can provide undetectable RDW manipulations even in room-scale VR.

  10. Effect of Bend Radius on Magnitude and Location of Erosion in S-Bend

    Directory of Open Access Journals (Sweden)

    Quamrul H. Mazumder

    2015-01-01

    Full Text Available Solid particle erosion is a mechanical process that removes material by the impact of solid particles entrained in the flow. Erosion is a leading cause of failure of oil and gas pipelines and fittings in fluid handling industries. Different approaches have been used to control or minimize damage caused by erosion in particulated gas-solid or liquid-solid flows. S-bend geometry is widely used in different fluid handling equipment that may be susceptible to erosion damage. The results of a computational fluid dynamic (CFD simulation of diluted gas-solid and liquid-solid flows in an S-bend are presented in this paper. In addition to particle impact velocity, the bend radius may have significant influence on the magnitude and the location of erosion. CFD analysis was performed at three different air velocities (15.24 m/s–45.72 m/s and three different water velocities (0.1 m/s–10 m/s with entrained solid particles. The particle sizes used in the analysis range between 50 and 300 microns. Maximum erosion was observed in water with 10 m/s, 250-micron particle size, and a ratio of 3.5. The location of maximum erosion was observed in water with 10 m/s, 300-micron particle size, and a ratio of 3.5. Comparison of CFD results with available literature data showed reasonable and good agreement.

  11. Preoperative urinary tract obstruction in scoliosis patients.

    Science.gov (United States)

    Suzuki, Shigeru; Kotani, Toshiaki; Mori, Kazuetsu; Kawamura, Ken; Ohtake, Akira

    2017-01-01

    While the association between scoliosis and cardiac and respiratory function impairments has been well characterized in clinical practice and research, the potential effect of scoliosis on urinary tract structure and renal function has received little attention. Therefore, the purpose of this study was to evaluate the preoperative clinical characteristics of urinary tract structure and renal function in pediatric patients with idiopathic scoliosis, using a combination of blood tests, urinalysis, and imaging. Preoperative measures of urinary tract structure and renal function were obtained for 16 patients, 13-17 years old, scheduled for corrective surgery for idiopathic scoliosis. Preoperative assessment included blood test and urinalysis, combined with structural imaging on ultrasound (US), magnetic resonance imaging (MRI), magnetic resonance urography (MRU), and radioisotope tracing (RI), using technetium-99 m mercaptoacetyltriglycine ((99m) Tc-MAG3). Differences in blood and urine tests between patients with and without urinary tract obstruction (UTO) were evaluated for significance using Mann-Whitney U test. For all 16 patients, blood tests and MRU were within normal limits. Dilatation of the renal pelvis was identified on US in eight patients (50.0%). UTO was identified on RI in six patients (37.5%). UTO was associated with elevated β2-microglobulin concentration. Urinary β2-microglobulin concentration >0.7 μg/mg Cr differentiated patients with UTO from those without UTO, with a sensitivity of 100% and specificity of 70%. β2-Microglobulin concentration may be a useful marker to screen for asymptomatic UTO in patients with idiopathic scoliosis. © 2016 Japan Pediatric Society.

  12. 36 CFR 7.41 - Big Bend National Park.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Big Bend National Park. 7.41 Section 7.41 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.41 Big Bend National Park. (a) Fishing; closed...

  13. Rule bending by morally disengaged detectives : an ethnographic study

    NARCIS (Netherlands)

    Loyens, Kim

    2014-01-01

    Rule bending is a well-known practice in policing worldwide, often linked to 'noble cause corruption'. This ethnographic study shows how police detectives sometimes consider to creatively bend rules when rule abidance would lead to other values being jeopardized. This paper illustrates that the theo

  14. On the Bending Problem for Large Scale Mapping

    NARCIS (Netherlands)

    Esteban, I.; Booij, O.; Dijk, J.; Groen, F.

    2010-01-01

    During Simultaneous Localization And Mapping, geometrical constraints are established between map features. These constraints, introduced through measurements and motion prediction, produce a bending effect in the event of closing a large loop. In this paper we present a discussion of the bending pr

  15. On the bending problem for large scale mapping

    NARCIS (Netherlands)

    I. Esteban; O. Booij; J. Dijk; F. Groen

    2009-01-01

    During Simultaneous Localization And Mapping, geometrical constraints are established between map features. These constraints, introduced through measurements and motion prediction, produce a bending effect in the event of closing a large loop. In this paper we present a discussion of the bending pr

  16. Bending Resistance of Steel Plate-Reinforced Concrete Beam

    Institute of Scientific and Technical Information of China (English)

    TIAN Zhimin; CHEN Jie

    2006-01-01

    The formulas for calculating bending-resistant capacity of a steel plate-reinforced concrete composite beam are derived.To validate the formulas,experiments of the composite beam under three-point bending are carried out.Calculated results based on the formulas are in good agreement with experimental results.

  17. On the bending problem for large scale mapping

    NARCIS (Netherlands)

    Esteban, I.; Booij, O.; Dijk, J.; Groen, F.

    2009-01-01

    During Simultaneous Localization And Mapping, geometrical constraints are established between map features. These constraints, introduced through measurements and motion prediction, produce a bending effect in the event of closing a large loop. In this paper we present a discussion of the bending

  18. APPLICABILITY OF THE BEND DEVELOPMENT THEORY IN NATURAL ALLUVIAL RIVERS

    Institute of Scientific and Technical Information of China (English)

    M.M.RAHMAN; M.A.HAQUE; M.M.HOQUE

    2002-01-01

    The theoretical conditions for the bend development or attenuation have been reviewed and tested for a study reach of the Meghna river.The field observations in the natural alluvial meander do not support the theories developed for bend development.The limitations of the theory to apply in the natural meandering river are discussed.

  19. Flexible DNA bending in HU-DNA cocrystal structures.

    Science.gov (United States)

    Swinger, Kerren K; Lemberg, Kathryn M; Zhang, Ying; Rice, Phoebe A

    2003-07-15

    HU and IHF are members of a family of prokaryotic proteins that interact with the DNA minor groove in a sequence-specific (IHF) or non-specific (HU) manner to induce and/or stabilize DNA bending. HU plays architectural roles in replication initiation, transcription regulation and site-specific recombination, and is associated with bacterial nucleoids. Cocrystal structures of Anabaena HU bound to DNA (1P71, 1P78, 1P51) reveal that while underlying proline intercalation and asymmetric charge neutralization mechanisms of DNA bending are similar for IHF and HU, HU stabilizes different DNA bend angles ( approximately 105-140 degrees ). The two bend angles within a single HU complex are not coplanar, and the resulting dihedral angle is consistent with negative supercoiling. Comparison of HU-DNA and IHF-DNA structures suggests that sharper bending is correlated with longer DNA binding sites and smaller dihedral angles. An HU-induced bend may be better modeled as a hinge, not a rigid bend. The ability to induce or stabilize varying bend angles is consistent with HU's role as an architectural cofactor in many different systems that may require differing geometries.

  20. Anharmonic bend-stretch coupling in neat liquid water

    NARCIS (Netherlands)

    Lindner, Joerg; Cringus, Dan; Pshenichnikov, Maxim S.; Voehringer, Peter

    2007-01-01

    Femtosecond mid-IR spectroscopy is used to study the vibrational relaxation dynamics in neat liquid water. By exciting the bending vibration and probing the stretching mode, it is possible to reliably determine the bending and librational lifetimes of water. The anharmonic coupling between the bendi

  1. Preoperative Evaluation: Estimation of Pulmonary Risk.

    Science.gov (United States)

    Lakshminarasimhachar, Anand; Smetana, Gerald W

    2016-03-01

    Postoperative pulmonary complications (PPCs) are common after major non-thoracic surgery and associated with significant morbidity and high cost of care. A number of risk factors are strong predictors of PPCs. The overall goal of the preoperative pulmonary evaluation is to identify these potential, patient and procedure-related risks and optimize the health of the patients before surgery. A thorough clinical examination supported by appropriate laboratory tests will help guide the clinician to provide optimal perioperative care. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. A preoperative checklist in esthetic plastic surgery

    OpenAIRE

    Anger,Jaime; Letizio,Nelson; Orel,Maurício; Souza Junior,José Leão de; Santos,Márcio Martines dos

    2011-01-01

    The authors present a checklist to be used at the last stage of a preoperative visit for esthetic plastic surgery composed of 29 yes/no questions, four blank spaces for entering data, and one question for ranking the level of risk of deep vein thrombosis. The criteria are divided into three tables relating to three areas: anesthesia, psychological aspects, and clinical risk factors. The answers are framed in four colors that identify the level of risk and suggest the degree of attention warra...

  3. Preoperational test report, recirculation ventilation systems

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-11-11

    This represents a preoperational test report for Recirculation Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102 and supports the ability to exhaust air from each tank. Each system consists of a valved piping loop, a fan, condenser, and moisture separator; equipment is located inside each respective tank farm in its own hardened building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  4. Preoperational test report, raw water system

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-10-29

    This represents the preoperational test report for the Raw Water System, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system supplies makeup water to the W-030 recirculation evaporative cooling towers for tanks AY1O1, AY102, AZ1O1, AZ102. The Raw Water pipe riser and associated strainer and valving is located in the W-030 diesel generator building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  5. Preoperative irradiation and cystectomy for bladder cancer.

    Science.gov (United States)

    Smith, J A; Batata, M; Grabstald, H; Sogani, P C; Herr, H; Whitmore, W F

    1982-03-01

    Between 1971 and 1974, 101 patients at Memorial Sloan-Kettering Cancer Center underwent planned integrated treatment for bladder cancer with 2000 rads by megavoltage delivered to the whole pelvis over five consecutive days followed by radical cystectomy within a week. The overall five-year survival rate was 39%; the hospital mortality rate was 2%. In the pelvis alone tumor recurred in 9% of the patients. These results support other studies demonstrating the efficacy of this and other regimens of preoperative irradiation and cystectomy.

  6. Atmospheric Refractive Electromagnetic Wave Bending and Propagation Delay

    CERN Document Server

    Mangum, Jeffrey G

    2014-01-01

    In this tutorial we summarize the physics and mathematics behind refractive electromagnetic wave bending and delay. Refractive bending and delay through the Earth's atmosphere at both radio/millimetric and optical/IR wavelengths are discussed, but with most emphasis on the former, and with Atacama Large Millimeter Array (ALMA) applications in mind. As modern astronomical measurements often require sub-arcsecond position accuracy, care is required when selecting refractive bending and delay algorithms. For the spherically-uniform model atmospheres generally used for all refractive bending and delay algorithms, positional accuracies $\\lesssim 1^{\\prime\\prime}$ are achievable when observing at zenith angles $\\lesssim 75^\\circ$. A number of computationally economical approximate methods for atmospheric refractive bending and delay calculation are presented, appropriate for astronomical observations under these conditions. For observations under more realistic atmospheric conditions, for zenith angles $\\gtrsim 75^...

  7. Sorting of bending magnets for the SSRF booster

    Institute of Scientific and Technical Information of China (English)

    HOU Jie; LIU Gui-Min; LI Hao-Hu; ZHANG Man-Zhou

    2008-01-01

    The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.

  8. Sorting of bending magnets for the SSRF booster

    Science.gov (United States)

    Hou, Jie; Liu, Gui-Min; Li, Hao-Hu; Zhang, Man-Zhou

    2008-04-01

    The Shanghai Synchrotron Radiation Facility (SSRF)booster ring, a full energy injector for the storage ring, is deigned to accelerate the electron beam energy from 150 MeV to 3.5 GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping. Closed orbit distortion (COD) caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting. Considering the affections of random errors in measurement, both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5 is given as the final installation sequence of the booster bending magnets in this paper. Supported by SSRF Project

  9. Revisit the anomalous bending elasticity of sharply bent DNA

    CERN Document Server

    Cong, Peiwen; Chen, Hu; van der Maarel, Johan R C; Doyle, Patrick S; Yan, Jie

    2015-01-01

    Several recent experiments have suggested that sharply bent DNA has a surprisingly high bending flexibility, but the cause is poorly understood. It has been demonstrated that excitation of flexible defects can explain the results; while whether such defects can be excited under the level of DNA bending in those experiments has remained unclear and been debated. Interestingly, due to experimental design DNA contained pre-existing nicks in nearly all those experiments, while the potential effect of nicks have never been considered. Here, using full-atom molecular dynamics (MD) simulations, we show that nicks promote DNA basepair disruption at the nicked sites which drastically reduced DNA bending energy. In the absence of nicks, basepair disruption can also occur, but it requires a higher level of DNA bending. Overall, our results challenge the interpretations of previous sharp DNA bending experiments and highlight that the micromechanics of sharply bent DNA still remains an open question.

  10. Role of xyloglucan in gravitropic bending of azuki bean epicotyl.

    Science.gov (United States)

    Ikushima, Toshimitsu; Soga, Kouichi; Hoson, Takayuki; Shimmen, Teruo

    2008-04-01

    The mechanism of the gravitropic bending was studied in azuki bean epicotyls. The cell wall extensibility of the lower side became higher than that of the upper side in the epicotyl bending upward. The contents of matrix polysaccharides of the cell wall (pectin and xyloglucan in hemicellulose-II) in the lower side became smaller than those in the upper side. The molecular mass of xyloglucans in the lower side decreased. After an epicotyl was fixed to a metal rod to prevent the bending, gravistimulation was applied. Fundamentally the same results were obtained with respect to rheological and chemical characteristics of the cell wall as those of epicotyls showing gravitropic bending. The present results suggested that the initial gravitropic bending was caused by the increase in extensibility of the lower side and the decrease in extensibility of the upper side via the change of the cell wall matrix, especially xyloglucans.

  11. Simulation and prediction in laser bending of silicon sheet

    Institute of Scientific and Technical Information of China (English)

    WANG Xu-yue; XU Wei-xing; XU Wen-ji; HU Ya-feng; LIANG Yan-de; WANG Lian-ji

    2011-01-01

    The laser bending of single-crystal silicon sheet (0.2 mm in thickness) was investigated with JK701 Nd:YAG laser. The models were developed to describe the beam characteristics of pulsed laser. In order to simulate the process of laser bending, the FEM softvare ANSYS was used to predict the heat temperature and stress-strain fields. The periodic transformation of temperature field and stress-strain distribution was analyzed during pulsed laser scanning silicon sheet. The results indicate that the mechanism of pulsed laser bending silicon is a hybrid mechanism in silicon bending, rather than a simple mechanism of TGM or BM. This work also gets silicon sheet bent after scanning 6 times with pulsed laser, and its bending angle is up to 6.5°. The simulation and prediction results reach well agreement with the verifying experiments.

  12. Analysis and Simulation of Adiabatic Bend Transitions in Optical Fibers

    Institute of Scientific and Technical Information of China (English)

    YAO Lei; LOU Shu-Qin; JIAN Shui-Sheng

    2009-01-01

    A low-loss criterion for bend transitions in optical fibers is proposed. An optical fiber can be tightly bent with low loss to be adiabatic for the fundamental mode, provided that an approximate upper bound on the rate of change of bend curvature for a given bend curvature is satisfied. Two typical adiabatic bend transition paths, the optimum profile and linear profile, are analyzed and studied numerically. A realizable adiabatic transition with an Archimedean spiral profile is introduced for low bend loss in tightly bent optical fibers. Design of the transitions is based on modeling of the propagation and coupling characteristics of the core and cladding modes,which clearly illustrate the physical processes involved.

  13. Bend-Induced Distortion in Large Mode Area Holey Fibre

    Institute of Scientific and Technical Information of China (English)

    TAN Xiao-Ling; GENG You-Fu; ZHANG Tie-Li; WANG Wei-Neng; WANG Peng; YAO Jian-Quan

    2008-01-01

    A simplified scheme of bend-induced mode distortion is introduced into bent holey fibres,the distorted mode distribution and mode effective area reduction are investigated using the finite difference method.Numerical results show that the modes of bent holey fibres with small bend radius shift away from the core and are deformed greatly,and the mode areas drop significantly as the bend radius decreases,which severely affects the fibre laser performance.The propagation characteristics of bent holey fibres at given wavelength are determined by fill factor and normalized bend radius.Finally,the transition normalized bend radius that represents the location of the mode area beginning to fall off is obtained.

  14. Religiousness and preoperative anxiety: a correlational study

    Directory of Open Access Journals (Sweden)

    Karimollahi Mansoureh

    2007-06-01

    Full Text Available Abstract Background Major life changes are among factors that cause anxiety, and one of these changes is surgery. Emotional reactions to surgery have specific effects on the intensity and velocity as well as the process of physical disease. In addition, they can cause delay in patients recovery. This study is aimed at determining the relationship between religious beliefs and preoperative anxiety. Methods This survey is a correlational study to assess the relationship between religious beliefs and preoperative anxiety of patients undergoing abdominal, orthopaedic, and gynaecologic surgery in educational hospitals. We used the convenience sampling method. The data collection instruments included a questionnaire containing the Spielberger State-Trait Anxiety Inventory (STAI, and another questionnaire formulated by the researcher with queries on religious beliefs and demographic characteristics as well as disease-related information. Analysis of the data was carried out with SPSS software using descriptive and inferential statistics. Results were arranged in three tables. Results The findings showed that almost all the subjects had high level of religiosity and moderate level of anxiety. In addition, there was an inverse relationship between religiosity and intensity of anxiety, though this was not statistically significant. Conclusion The results of this study can be used as evidence for presenting religious counselling and spiritual interventions for individuals undergoing stress. Finally, based on the results of this study, the researcher suggested some recommendations for applying results and conducting further research.

  15. Preoperative chemoradiotherapy for locally advanced gastric cancer

    Directory of Open Access Journals (Sweden)

    Pepek Joseph M

    2013-01-01

    Full Text Available Abstract Background To examine toxicity and outcomes for patients treated with preoperative chemoradiotherapy (CRT for gastric cancer. Methods Patients with gastroesophageal (GE junction (Siewert type II and III or gastric adenocarcinoma who underwent neoadjuvant CRT followed by planned surgical resection at Duke University between 1987 and 2009 were reviewed. Overall survival (OS, local control (LC and disease-free survival (DFS were estimated using the Kaplan-Meier method. Toxicity was graded according to the Common Toxicity Criteria for Adverse Events version 4.0. Results Forty-eight patients were included. Most (73% had proximal (GE junction, cardia and fundus tumors. Median radiation therapy dose was 45 Gy. All patients received concurrent chemotherapy. Thirty-six patients (75% underwent surgery. Pathologic complete response and R0 resection rates were 19% and 86%, respectively. Thirty-day surgical mortality was 6%. At 42 months median follow-up, 3-year actuarial OS was 40%. For patients undergoing surgery, 3-year OS, LC and DFS were 50%, 73% and 41%, respectively. Conclusions Preoperative CRT for gastric cancer is well tolerated with acceptable rates of perioperative morbidity and mortality. In this patient cohort with primarily advanced disease, OS, LC and DFS rates in resected patients are comparable to similarly staged, adjuvantly treated patients in randomized trials. Further study comparing neoadjuvant CRT to standard treatment approaches for gastric cancer is indicated.

  16. Preoperative evaluation for lung cancer resection

    Science.gov (United States)

    Spyratos, Dionysios; Porpodis, Konstantinos; Angelis, Nikolaos; Papaiwannou, Antonios; Kioumis, Ioannis; Pitsiou, Georgia; Pataka, Athanasia; Tsakiridis, Kosmas; Mpakas, Andreas; Arikas, Stamatis; Katsikogiannis, Nikolaos; Kougioumtzi, Ioanna; Tsiouda, Theodora; Machairiotis, Nikolaos; Siminelakis, Stavros; Argyriou, Michael; Kotsakou, Maria; Kessis, George; Kolettas, Alexander; Beleveslis, Thomas; Zarogoulidis, Konstantinos

    2014-01-01

    During the last decades lung cancer is the leading cause of death worldwide for both sexes. Even though cigarette smoking has been proved to be the main causative factor, many other agents (e.g., occupational exposure to asbestos or heavy metals, indoor exposure to radon gas radiation, particulate air pollution) have been associated with its development. Recently screening programs proved to reduce mortality among heavy-smokers although establishment of such strategies in everyday clinical practice is much more difficult and unknown if it is cost effective compared to other neoplasms (e.g., breast or prostate cancer). Adding severe comorbidities (coronary heart disease, COPD) to the above reasons as cigarette smoking is a common causative factor, we could explain the low surgical resection rates (approximately 20-30%) for lung cancer patients. Three clinical guidelines reports of different associations have been published (American College of Chest Physisians, British Thoracic Society and European Respiratory Society/European Society of Thoracic Surgery) providing detailed algorithms for preoperative assessment. In the current mini review, we will comment on the preoperative evaluation of lung cancer patients. PMID:24672690

  17. The Amsterdam preoperative anxiety and information scale provides a simple and reliable measure of preoperative anxiety.

    Science.gov (United States)

    Boker, Abdulaziz; Brownell, Laurence; Donen, Neil

    2002-10-01

    To compare three anxiety scales; the anxiety visual analogue scale (VAS), the anxiety component of the Amsterdam preoperative anxiety and information scale (APAIS), and the state portion of the Spielburger state-trait anxiety inventory (STAI), for assessment of preoperative anxiety levels in same day admission patients. Patients completed the three anxiety assessment scales both before and after seeing the anesthesiologist preoperatively. The scales used were the STAI, the six-question APAIS, and the VAS. APAIS was further subdivided to assess anxiety about anesthesia (sum A), anxiety about surgery (sum S) and a combined anxiety total (i.e., sum C = sum A + sum S). These scales were compared to one another. Pearson's correlation (pair-wise deletion) was used for validity testing. Cronbach's alpha analysis was used to test internal validity of the various components of the APAIS scale. A correlation co-efficient (r) > or = 0.6 and P scale sets were completed by 197 patients. There was significant and positive correlation between VAS and STAI r = 0.64, P anxiety components of the APAIS (sum C) and desire for information were 0.84 and 0.77 respectively. In addition to VAS, the anxiety component of APAIS (sum C) is a promising new practical tool to assess preoperative patient anxiety levels.

  18. ZERODUR: bending strength data for etched surfaces

    Science.gov (United States)

    Hartmann, Peter; Leys, Antoine; Carré, Antoine; Kerz, Franca; Westerhoff, Thomas

    2014-07-01

    In a continuous effort since 2007 a considerable amount of new data and information has been gathered on the bending strength of the extremely low thermal expansion glass ceramic ZERODUR®. By fitting a three parameter Weibull distribution to the data it could be shown that for homogenously ground surfaces minimum breakage stresses exist lying much higher than the previously applied design limits. In order to achieve even higher allowable stress values diamond grain ground surfaces have been acid etched, a procedure widely accepted as strength increasing measure. If surfaces are etched taking off layers with thickness which are comparable to the maximum micro crack depth of the preceding grinding process they also show statistical distributions compatible with a three parameter Weibull distribution. SCHOTT has performed additional measurement series with etch solutions with variable composition testing the applicability of this distribution and the possibility to achieve further increase of the minimum breakage stress. For long term loading applications strength change with time and environmental media are important. The parameter needed for prediction calculations which is combining these influences is the stress corrosion constant. Results from the past differ significantly from each other. On the basis of new investigations better information will be provided for choosing the best value for the given application conditions.

  19. Bending strength of delaminated aerospace composites.

    Science.gov (United States)

    Kinawy, Moustafa; Butler, Richard; Hunt, Giles W

    2012-04-28

    Buckling-driven delamination is considered among the most critical failure modes in composite laminates. This paper examines the propagation of delaminations in a beam under pure bending. A pre-developed analytical model to predict the critical buckling moment of a thin sub-laminate is extended to account for propagation prediction, using mixed-mode fracture analysis. Fractography analysis is performed to distinguish between mode I and mode II contributions to the final failure of specimens. Comparison between experimental results and analysis shows agreement to within 5 per cent in static propagation moment for two different materials. It is concluded that static fracture is almost entirely driven by mode II effects. This result was unexpected because it arises from a buckling mode that opens the delamination. For this reason, and because of the excellent repeatability of the experiments, the method of testing may be a promising means of establishing the critical value of mode II fracture toughness, G(IIC), of the material. Fatigue testing on similar samples showed that buckled delamination resulted in a fatigue threshold that was over 80 per cent lower than the static propagation moment. Such an outcome highlights the significance of predicting snap-buckling moment and subsequent propagation for design purposes.

  20. 2014 land cover land use horseshoe bend

    Science.gov (United States)

    Hanson, Jenny L.; Hoy, Erin E.; Robinson, Larry R.

    2016-01-01

    This collection of conservation areas consists of the floodplain of the combined streams of the Iowa River and the Cedar River. The study area begins just southeast of Wapello, IA, and continues southeast until the Horseshoe Bend Division, Port Louisa NWR. The area is currently managed to maintain meadow or grassland habitat which requires intensive management due to vegetative succession. In addition, this floodplain area contains a high proportion of managed lands and private lands in the Wetland Reserve Program and is a high priority area for cooperative conservation actions. This project provides a late-summer baseline vegetation inventory to assess future management actions in an adaptive process. Changes in levees, in addition to increased water flows and flood events due to climate change and land use practices, make restoration of floodplain processes more complex. Predictive models could help determine more efficient and effective restoration and management techniques. Successful GIS tools developed for this project would be applicable to other floodplain refuges and conservation areas.

  1. Measuring preoperative anxiety in patients with intracranial tumors: the Amsterdam preoperative anxiety and information scale.

    Science.gov (United States)

    Goebel, Simone; Kaup, Lea; Mehdorn, Hubertus Maximilian

    2011-10-01

    Preoperative anxiety is a major problem in patients with brain tumors and is of high clinical relevance. However, to date no instruments have been validated for the assessment of preoperative anxiety for this patient group. The Amsterdam Preoperative Anxiety and Information Scale (APAIS) has shown promising results for the assessment of preoperative anxiety. The aim of this study was to determine its psychometric properties and the optimal cutoff score for patients with intracranial tumors to make it applicable in the neurosurgical setting. The sample totaled 180 neurosurgical patients with intracranial tumors. Patients were administered the APAIS along with the Hospital Anxiety and Depression Scale as the gold standard against which the APAIS was compared. Patients scoring 11 or above in the anxiety subscale of the Hospital Anxiety and Depression Scale were defined as clinical cases having anxiety. The psychometric properties of the APAIS were evaluated for a postulated 2-factor structure, Cronbach α, and correlations. The postulated 2-factor structure could not be replicated. Instead, we found a 3-factor solution (anxiety about the operation, anxiety about the anesthesia, information requirement). The area under the receiver operating characteristics curve ranged from ≥0.65 to ≥0.77. Optimal cutoff scores were calculated. The cutoff score for the anxiety scale was ≥10 for the whole sample and men only, and was ≥11 for women only. Analysis of the psychometric properties yielded satisfactory results (eg. Cronbach α for the anxiety scale >0.84). Despite its brevity, the APAIS is valid and recommendable for the assessment of preoperative anxiety in patients with intracranial tumors. As this is the first validation study focusing on patients with severe diseases and major surgeries, we recommend the application of our cutoff scores also for patients similar to our study population with regard to disease and surgery severity.

  2. The effect of preoperative smoking cessation or preoperative pulmonary rehabilitation on outcomes after lung cancer surgery: a systematic review.

    Science.gov (United States)

    Schmidt-Hansen, Mia; Page, Richard; Hasler, Elise

    2013-03-01

    The preferred treatment for lung cancer is surgery if the disease is considered resectable and the patient is considered surgically fit. Preoperative smoking cessation and/or preoperative pulmonary rehabilitation might improve postoperative outcomes after lung cancer surgery. The objectives of this systematic review were to determine the effectiveness of (1) preoperative smoking cessation and (2) preoperative pulmonary rehabilitation on peri- and postoperative outcomes in patients who undergo resection for lung cancer. We searched MEDLINE, PreMedline, Embase, Cochrane Library, Cinahl, BNI, Psychinfo, Amed, Web of Science (SCI and SSCI), and Biomed Central. Original studies published in English investigating the effect of preoperative smoking cessation or preoperative pulmonary rehabilitation on operative and longer-term outcomes in ≥ 50 patients who received surgery with curative intent for lung cancer were included. Of the 7 included studies that examined the effect of preoperative smoking cessation (n = 6) and preoperative pulmonary rehabilitation (n = 1) on outcomes after lung cancer surgery, none were randomized controlled trials and only 1 was prospective. The studies used different smoking classifications, the baseline characteristics differed between the study groups in some of the studies, and most had small sample sizes. No formal data synthesis was therefore possible. The included studies were marked by methodological limitations. On the basis of the reported bodies of evidence, it is not possible to make any firm conclusions about the effect of preoperative smoking cessation or of preoperative pulmonary rehabilitation on operative outcomes in patients undergoing surgery for lung cancer.

  3. Pre-operative pain and sensory function in groin hernia

    DEFF Research Database (Denmark)

    Aasvang, Eske K; Hansen, Jeanette B; Kehlet, Henrik

    2009-01-01

    mechanism. AIMS: To investigate the correlation between pre-operative pain intensity and sensory functions in the groin hernia area. METHODS: Patients with unilateral groin hernia were examined preoperatively by quantitative sensory testing (thermal, mechanical, and pressure [detection and pain thresholds...... pain is not related to findings of hyperalgesia or other changes in sensory function that may support pain-induced pre-operative neuroplasticity as a pathogenic mechanism for the development of persistent postherniotomy pain....

  4. PROGRESS IN STUDIES ON ICE ACCUMULATION IN RIVER BENDS

    Institute of Scientific and Technical Information of China (English)

    WANG Jun; CHEN Pang-pang; SUI Jue-yi

    2011-01-01

    River ice is an important hydraulic element in temperate and polar environments and would affect hydrodynamic conditions of rivers through changes both in the boundary conditions and the thermal regime.The river bend has been reported as the common location for the initiation of ice jams because the water flow along a river bend is markedly affected by the channel curvature.In this article,the experimental studies about the ice accumulation in a river bend are reviewed.Based on experiments conducted so far,the criteria for the formation of ice jams in the river bend,the mechanisms of the ice accumulation in the river bend and the thickness profile of the ice accumulation in the river bend are discussed.The k- ε two-equation turbulence model is used to simulate the ice accumulation under an ice cover along a river bend.A formula is proposed for describing the deformation of the ice jam bottom.Our results indicate that all simulated thickness of the ice accumulation agrees reasonably well with the measured thickness of the ice accumulation in the laboratory.

  5. Fixed bending current for Elekta SL25 linear accelerators.

    Science.gov (United States)

    Kok, J G

    2001-01-01

    In a medical linear accelerator a bending magnet is used to bend the electron beam produced by the accelerator tube, in the treatment direction. For each electron energy the strength of the magnetic field has to be set to a specific level. Changing the magnetic field strength is done by changing the electric current through the bending magnet. When electron energy and magnetic field strength are not matched, performance of the linac can be affected. As electron energy, magneticfield strength and electrical current through the bending magnet are related to each other, it is reasonable to assume that for each electron energy the correct bending current can be predetermined. This calculated bending current reduces the number of variable parameters used to set up a treatment beam. Predetermining a variable simplifies the tuning procedures. It also prevents a deviation of the electron beam energy being compensated by variation of the bending current. Preventing false machine settings can contribute to increase linac performance and reduce down time and cost of ownership.

  6. Behavior of sandwich panels subjected to bending fatigue, axial compression loading and in-plane bending

    Science.gov (United States)

    Mathieson, Haley Aaron

    This thesis investigates experimentally and analytically the structural performance of sandwich panels composed of glass fibre reinforced polymer (GFRP) skins and a soft polyurethane foam core, with or without thin GFRP ribs connecting skins. The study includes three main components: (a) out-of-plane bending fatigue, (b) axial compression loading, and (c) in-plane bending of sandwich beams. Fatigue studies included 28 specimens and looked into establishing service life (S-N) curves of sandwich panels without ribs, governed by soft core shear failure and also ribbed panels governed by failure at the rib-skin junction. Additionally, the study compared fatigue life curves of sandwich panels loaded under fully reversed bending conditions (R=-1) with panels cyclically loaded in one direction only (R=0) and established the stiffness degradation characteristics throughout their fatigue life. Mathematical models expressing fatigue life and stiffness degradation curves were calibrated and expanded forms for various loading ratios were developed. Approximate fatigue thresholds of 37% and 23% were determined for non-ribbed panels loaded at R=0 and -1, respectively. Digital imaging techniques showed significant shear contribution significantly (90%) to deflections if no ribs used. Axial loading work included 51 specimens and examined the behavior of panels of various lengths (slenderness ratios), skin thicknesses, and also panels of similar length with various rib configurations. Observed failure modes governing were global buckling, skin wrinkling or skin crushing. In-plane bending involved testing 18 sandwich beams of various shear span-to-depth ratios and skin thicknesses, which failed by skin wrinkling at the compression side. The analytical modeling components of axially loaded panels include; a simple design-oriented analytical failure model and a robust non-linear model capable of predicting the full load-displacement response of axially loaded slender sandwich panels

  7. Four point bending setup for characterization of semiconductor piezoresistance

    DEFF Research Database (Denmark)

    Richter, Jacob; Arnoldus, Morten Berg; Hansen, Ole

    2008-01-01

    We present a four point bending setup suitable for high precision characterization of piezoresistance in semiconductors. The compact setup has a total size of 635 cm3. Thermal stability is ensured by an aluminum housing wherein the actual four point bending fixture is located. The four point...... bending fixture is manufactured in polyetheretherketon and a dedicated silicon chip with embedded piezoresistors fits in the fixture. The fixture is actuated by a microstepper actuator and a high sensitivity force sensor measures the applied force on the fixture and chip. The setup includes heaters...

  8. Stored Energy of Plastic Deformation in Tube Bending Processes

    Science.gov (United States)

    Śloderbach, Z.; Pająk, J.

    2013-03-01

    The paper presents an aproximate analytic method for determination of the stored energy of plastic deformation during cold bending of metal tubes at bending machines. Calculations were performed for outer points of the tube layers subjected to tension and compression (the points of maximum strains). The percentage of stored energy related to the plastic strain work was determined and the results were presented in graphs. The influence and importance of the stored energy of plastic deformation on the service life of pipeline bends are discussed.

  9. Hamiltonian system for orthotropic plate bending based on analogy theory

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on analogy between plane elasticity and plate bending as well as variational principles of mixed energy, Hamiltonian system is further led to orthotropic plate bending problems in this paper. Thus many effective methods of mathematical physics such as separation of variables and eigenfunction expansion can be employed in orthotropic plate bending problems as they are used in plane elasticity. Analytical solutions of rectangular plate are presented directly, which expands the range of analytical solutions. There is an essential distinction between this method and traditional semi-inverse method. Numerical results of orthotropic plate with two lateral sides fixed are included to demonstrate the effectiveness and accuracy of this method.

  10. Bends in nanotubes allow electric spin control and coupling

    DEFF Research Database (Denmark)

    Flensberg, Karsten; Marcus, Charles Masamed

    2010-01-01

    We investigate combined effects of spin-orbit coupling and magnetic field in carbon nanotubes containing one or more bends along their length. We show how bends can be used to provide electrical control of confined spins, while spins confined in straight segments remain insensitive to electric...... fields. Device geometries that allow general rotation of single spins are presented and analyzed. In addition, capacitive coupling along bends provides coherent spin-spin interaction, including between otherwise disconnected nanotubes, completing a universal set of one- and two-qubit gates....

  11. Buffers affect the bending rigidity of model lipid membranes.

    Science.gov (United States)

    Bouvrais, Hélène; Duelund, Lars; Ipsen, John H

    2014-01-14

    In biophysical and biochemical studies of lipid bilayers the influence of the used buffer is often ignored or assumed to be negligible on membrane structure, elasticity, or physical properties. However, we here present experimental evidence, through bending rigidity measurements performed on giant vesicles, of a more complex behavior, where the buffering molecules may considerably affect the bending rigidity of phosphatidylcholine bilayers. Furthermore, a synergistic effect on the bending modulus is observed in the presence of both salt and buffer molecules, which serves as a warning to experimentalists in the data interpretation of their studies, since typical lipid bilayer studies contain buffer and ion molecules.

  12. Influence of plywood grain direction on sandwich panel bending properties

    OpenAIRE

    Jaroslav Kljak; Mladen Brezović; Alan Antonović

    2009-01-01

    This paper investigates the influence of plywood grain direction on bending properties of a sandwich panel, as well as on stress distribution in each layer. Experimental sandwich panels (tnom= 29 mm) were made of two three-ply plywood panels and a rigid PVC core between them. Grain directions of plywood panels were between 0° and 90°, continuously raised by 15°. Seven models of sandwich panels were made. Bending properties of a sandwich panel was determined by three point bending method and s...

  13. Damage Analysis of Rectangular Section Composite Beam under Pure Bending

    Science.gov (United States)

    Liu, Yiping; Xiao, Fan; Liu, Zejia; Tang, Liqun; Fang, Daining

    2013-02-01

    Laminated composite beams are commonly used in engineering applications involving macro to nano structures. Based on the assumption that plain sections remain plain after deformation, this paper analyzes stress distributions in cross-ply laminated composite beams with rectangular cross-sections, and formulates the basic damage equations through Kachanov's damage definition and Janson's failure criterion. The location of the neutral axis and the ultimate bending moment are obtained for pure bending cases. The effect of the elastic modulus of the two layers on the damage evolution is analyzed; a reasonable damage composite beam model is proposed to predict the ultimate bending moment.

  14. Preoperational test report, recirculation condenser cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-11-04

    This represents a preoperational test report for Recirculation Condenser Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The four system provide condenser cooling water for vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102. Each system consists of a valved piping loop, a pair of redundant recirculation pumps, a closed-loop evaporative cooling tower, and supporting instrumentation; equipment is located outside the farm on concrete slabs. Piping is routed to the each ventilation condenser inside the farm via below-grade concrete trenches. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  15. Pre-operative antiseptic skin preparation.

    Science.gov (United States)

    Murkin, Claire Elizabeth

    Theatre nurses use antiseptic skin preparation products every day, but little thought seems to be given as to why a surgeon has a particular preference for one antiseptic skin preparation over another - whether it is for its efficacy, safety or application properties. Woodhead et al (2004) states that nurses still work in a ritualistic environment. Rituals are 'any action performed according to custom, without understanding the reasons why it is being practised'. Nursing practice should be evidence-based; nurses should understand the rationale behind the choice of a particular antiseptic, and be knowledgable about the clinical effectiveness of antiseptic's use pre-operatively, to achieve optimum results. This article focuses on the main types of antiseptic skin preparation while highlighting each product's activity and the relevant considerations for choosing the appropriate product for each patient. Theatre staff need to emphasize the importance of skin preparation and the correct application techniques, while educating the scrub team and surgeons with respect to skin preparation.

  16. Preoperational test report, recirculation condenser cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-11-04

    This represents a preoperational test report for Recirculation Condenser Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The four system provide condenser cooling water for vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102. Each system consists of a valved piping loop, a pair of redundant recirculation pumps, a closed-loop evaporative cooling tower, and supporting instrumentation; equipment is located outside the farm on concrete slabs. Piping is routed to the each ventilation condenser inside the farm via below-grade concrete trenches. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  17. Predictors of preoperative anxiety in children.

    Science.gov (United States)

    Wollin, S R; Plummer, J L; Owen, H; Hawkins, R M F; Materazzo, F

    2003-02-01

    This study aimed to identify factors contributing to anxiety at induction of anaesthesia in children. One hundred and twenty children aged five to twelve years and scheduled for surgery requiring general anaesthesia were included. Children were interviewed and assessed prior to surgery. Parents completed anxiety measures prior to surgery and were interviewed after the induction of anaesthesia. The level of children's anxiety was determined at the time of induction of anaesthesia by the modified Yale Preoperative Anxiety Scale. Factors associated with increased levels of anxiety in the children included increased number of people in the room at induction of anaesthesia; longer waiting time between admission at the hospital and induction of anaesthesia; negative memories of previous hospital experiences; and having a mother who does not practise a religion. Suggestions for implementation of the findings and for future research are provided.

  18. Preoperative information needs of children undergoing tonsillectomy.

    LENUS (Irish Health Repository)

    Buckley, Aoife

    2012-02-01

    AIMS AND OBJECTIVES: To identify the information needs of children undergoing tonsillectomy with reference to content of information, method of delivery, information providers and timing of information provision. BACKGROUND: Tonsillectomy can be anxiety provoking for children and preoperative preparation programmes are long recognised to reduce anxiety. However, few have been designed from the perspectives of children and to date little is known about how best to prepare children in terms of what to tell them, how to convey information to them, who can best provide information and what is the best timing for information provision. DESIGN: A qualitative descriptive study. METHOD: Data were collected from nine children (aged 6-9) using interviews supported by a write and draw technique. Data were coded and categorised into themes reflecting content, method, providers and timing of information. RESULTS: Children openly communicated their information needs especially on what to tell them to expect when facing a tonsillectomy. Their principal concerns were about operation procedures, experiencing \\'soreness\\' and discomfort postoperatively and parental presence. Mothers were viewed as best situated to provide them with information. Children were uncertain about what method of information and timing would be most helpful to them. CONCLUSION: Preoperative educational interventions need to take account of children\\'s information needs so that they are prepared for surgery in ways that are meaningful and relevant to them. Future research is needed in this area. RELEVANCE TO CLINICAL PRACTICE: Practical steps towards informing children about having a tonsillectomy include asking them what they need to know and addressing their queries accordingly. Child-centred information leaflets using a question and answer format could also be helpful to children.

  19. "Bending the cost curve" in gastroenterology.

    Science.gov (United States)

    Slattery, E; Harewood, G C; Murray, F; Patchett, S

    2013-12-01

    Increasing attention is being focused on reigning in escalating costs of healthcare, i.e. trying to 'bend the cost curve'. In gastroenterology (GI), inpatient hospital care represents a major component of overall costs. This study aimed to characterize the trend in cost of care for GI-related hospitalizations in recent years and to identify the most costly diagnostic groups. All hospital inpatients admitted between January 2008 and December 2009 with a primary diagnosis of one of the six most common GI-related Diagnosis Related Groups (DRGs) in this hospital system were identified; all DRGs contained at least 40 patients during the study period. Patient Level Costing (PLC) was used to express the total cost of hospital care for each patient; PLC comprised a weighted daily bed cost plus cost of all medical services provided (e.g., radiology, pathology tests) calculated according to an activity-based costing approach; cost of medications were excluded. All costs were discounted to 2009 values. Mean length of stay (LOS) was also calculated for each DRG. Over 2 years, 470 patients were admitted with one of the six most common GI DRGs. Mean cost of care increased from 2008 to 2009 for all six DRGs with the steepest increases seen in 'GI hemorrhage (non-complex)' (31 % increase) and 'Cirrhosis/Alcoholic hepatitis (non-complex)' (45 % increase). No differences in readmission rates were observed over time. There was a strong correlation between year-to-year change in costs and change in mean LOS, r = 0.93. The cost of GI-related inpatient care appears to be increasing in recent years with the steepest increases observed in non-complex GI hemorrhage and non-complex Cirrhosis/Alcoholic hepatitis. Efforts to control the increasing costs should focus on these diagnostic categories.

  20. Advantages of customer/supplier involvement in the upgrade of River Bend`s IST program

    Energy Technology Data Exchange (ETDEWEB)

    Womack, R.L.; Addison, J.A.

    1996-12-01

    At River Bend Station, IST testing had problems. Operations could not perform the test with the required repeatability; engineering could not reliably trend test data to detect degradation; licensing was heavily burdened with regulatory concerns; and maintenance could not do preventative maintenance because of poor prediction of system health status. Using Energy`s Total Quality principles, it was determined that the causes were: lack of ownership, inadequate test equipment usage, lack of adequate procedures, and lack of program maintenance. After identifying the customers and suppliers of the IST program data, Energy management put together an upgrade team to address these concerns. These customers and suppliers made up the IST upgrade team. The team`s mission was to supply River Bend with a reliable, functional, industry correct and user friendly IST program. The IST program in place went through a verification process that identified and corrected over 400 individual program discrepancies. Over 200 components were identified for improved testing methods. An IST basis document was developed. The operations department was trained on ASME Section XI testing. All IST tests have been simplified and shortened, due to heavy involvement by operations in the procedure development process. This significantly reduced testing time, resulting in lower cost, less dose and greater system availability.

  1. Monitoring Composites under Bending Tests with Infrared Thermography

    Directory of Open Access Journals (Sweden)

    Carosena Meola

    2012-01-01

    Full Text Available The attention of the present paper is focused on the use of an infrared imaging device to monitor the thermal response of composite materials under cyclic bending. Three types of composites are considered including an epoxy matrix reinforced with either carbon fibres (CFRP or glass fibres (GFRP and a hybrid composite involving glass fibres and aluminium layers (FRML. The specimen surface, under bending, displays temperature variations pursuing the load variations with cooling down under tension and warming up under compression; such temperature variations are in agreement with the bending moment. It has been observed that the amplitude of temperature variations over the specimen surface depends on the material characteristics. In particular, the presence of a defect inside the material affects the temperature distribution with deviation from the usual bending moment trend.

  2. Turbulent flow computation in a circular U-Bend

    Directory of Open Access Journals (Sweden)

    Miloud Abdelkrim

    2014-03-01

    Full Text Available Turbulent flows through a circular 180° curved bend with a curvature ratio of 3.375, defined as the the bend mean radius to pipe diameter is investigated numerically for a Reynolds number of 4.45×104. The computation is performed for a U-Bend with full long pipes at the entrance and at the exit. The commercial ANSYS FLUENT is used to solve the steady Reynolds–Averaged Navier–Stokes (RANS equations. The performances of standard k-ε and the second moment closure RSM models are evaluated by comparing their numerical results against experimental data and testing their capabilities to capture the formation and extend this turbulence driven vortex. It is found that the secondary flows occur in the cross-stream half-plane of such configurations and primarily induced by high anisotropy of the cross-stream turbulent normal stresses near the outer bend.

  3. Fishery Manangement Plan : Holla Bend National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This plan describes fishery management for Holla Bend National Wildlife Refuge in 1990. The plan outlines goals, objectives for fishery management for the benefit of...

  4. Holla Bend National Wildlife Refuge: Comprehensive Conservation Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on Holla Bend NWR for the next 15 years. This plan outlines the Refuge vision and purpose...

  5. Novel boundary element method for resolving plate bending problems

    Institute of Scientific and Technical Information of China (English)

    陈颂英; 王乐勤; 焦磊

    2003-01-01

    This paper discusses the application of the boundary contour method for resolving plate bending problems. The exploitation of the integrand divergence free property of the plate bending boundary integral equation based on the Kirchhoff hypothesis and a very useful application of Stokes' Theorem are presented to convert surface integrals on boundary elements to the computation of bending potential functions on the discretized boundary points, even for curved surface elements of arbitrary shape. Singularity and treatment of the discontinued corner point are not needed at all. The evaluation of the physics variant at internal points is also shown in this article. Numerical results are presented for some plate bending problems and compared against analytical and previous solutions.

  6. Low Cycle Fatigue of Steel in Strain Controled Cyclic Bending

    Directory of Open Access Journals (Sweden)

    Kulesa Anna

    2016-03-01

    Full Text Available The paper presents a comparison of the fatigue life curves based on test of 15Mo3 steel under cyclic, pendulum bending and tension-compression. These studies were analyzed in terms of a large and small number of cycles where strain amplitude is dependent on the fatigue life. It has been shown that commonly used Manson-Coffin-Basquin model cannot be used for tests under cyclic bending due to the impossibility of separating elastic and plastic strains. For this purpose, some well-known models of Langer and Kandil and one new model of authors, where strain amplitude is dependent on the number of cycles, were proposed. Comparing the results of bending with tension-compression it was shown that for smaller strain amplitudes the fatigue life for both test methods were similar, for higher strain amplitudes fatigue life for bending tests was greater than for tension-compression.

  7. Gender differences in variability patterns of forward bending

    DEFF Research Database (Denmark)

    Villumsen, Morten; Madeleine, Pascal; Jørgensen, Marie Birk

    2016-01-01

    The variability pattern is highly relevant in the analysis of occupational physical exposures. It is hypothesized that gender differences exist in the variability pattern of forward bending between work and leisure....

  8. 1984 Deer Harvest Summary for Holla Bend National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This memo summarizes the 1984 deer harvest for Holla Bend National Wildlife Refuge. Tables summarize numerical findings, including bucks, does, and points.

  9. Narrative report 1968: U. L. Bend National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Ul Bend NWR outlines Refuge accomplishments during the 1968 calendar year. The report begins by summarizing the weather conditions,...

  10. Wildlife Inventory Plan : Holla Bend National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This plan describes wildlife inventory in Holla Bend National Wildlife Refuge in 1983. This plan helps achieve refuge objectives by detailing the plan, purpose, and...

  11. Magnetically Assisted Bilayer Composites for Soft Bending Actuators

    Directory of Open Access Journals (Sweden)

    Sung-Hwan Jang

    2017-06-01

    Full Text Available This article presents a soft pneumatic bending actuator using a magnetically assisted bilayer composite composed of silicone polymer and ferromagnetic particles. Bilayer composites were fabricated by mixing ferromagnetic particles to a prepolymer state of silicone in a mold and asymmetrically distributed them by applying a strong non-uniform magnetic field to one side of the mold during the curing process. The biased magnetic field induces sedimentation of the ferromagnetic particles toward one side of the structure. The nonhomogeneous distribution of the particles induces bending of the structure when inflated, as a result of asymmetric stiffness of the composite. The bilayer composites were then characterized with a scanning electron microscopy and thermogravimetric analysis. The bending performance and the axial expansion of the actuator were discussed for manipulation applications in soft robotics and bioengineering. The magnetically assisted manufacturing process for the soft bending actuator is a promising technique for various applications in soft robotics.

  12. Active vibration control of structures undergoing bending vibrations

    Science.gov (United States)

    Pla, Frederic G. (Inventor); Rajiyah, Harindra (Inventor)

    1995-01-01

    An active vibration control subassembly for a structure (such as a jet engine duct or a washing machine panel) undergoing bending vibrations caused by a source (such as the clothes agitator of the washing machine) independent of the subassembly. A piezoceramic actuator plate is vibratable by an applied electric AC signal. The plate is connected to the structure such that vibrations in the plate induced by the AC signal cause canceling bending vibrations in the structure and such that the plate is compressively pre-stressed along the structure when the structure is free of any bending vibrations. The compressive prestressing increases the amplitude of the canceling bending vibrations before the critical tensile stress level of the plate is reached. Preferably, a positive electric DC bias is also applied to the plate in its poling direction.

  13. Preliminary Project Investigation : Holla Bend National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report covers the proposed expansion of Holla Bend National Wildlife Refuge to increase the quantity and quality of wintering habitat primarily for mallards and...

  14. Energy Dissipation Analysis of Bended SMA Bar in Isothermal State

    Institute of Scientific and Technical Information of China (English)

    PENG Gang; LI Li; TAN Jia-xiang

    2004-01-01

    The theory calculation formula is deduced about stress distribution in cross section and changes in Martensite percentages with the section height of random section shape bar under the action of the bending moment according to the Brinson's Constitutive Relation.The bar's energy dissipation capability under circulation of bending moment was analyzed and the calculation theory was set up. By using MATLAB program and the numerical calculation for uniform rectangle cross section bar, the relationships among the maximal stress and strain on cross section edge with bend load, the stress and Martensite percent's with cross section height, the energy dissipation capability with cross section height, and the energy dissipation capability with maximal strain on cross section edge are gained, also those curves are discused. It is put forward that the SMA material can be used for passive structure vibration control to dissipate energy of bend load.

  15. Tidal bending of glaciers: a linear viscoelastic approach

    DEFF Research Database (Denmark)

    Reeh, Niels; Christensen, Erik Lintz; Mayer, Christoph;

    2003-01-01

    In theoretical treatments of tidal bending of floating glaciers, the glacier is usually modelled as an elastic beam with uniform thickness, resting on an elastic foundation. With a few exceptions, values of the elastic (Young's) modulus E of ice derived from tidal deflection records of floating...... glaciers are in the range 0.9-3 GPa. It has therefore been suggested that the elastic-beam model with a single value of E approximate to 1 GPa adequately describes tidal bending of glaciers.In contrast, laboratory experiments with ice give E =93 GPa, i.e. 3-10 times higher than the glacier-derived values....... This suggests that ice creep may have a significant influence on tidal bending of glaciers. Moreover, detailed tidal-deflection and tilt data from Nioghalvfjerdsfjorden glacier, northeast Greenland, cannot be explained by elastic-beam theory. We present a theory of tidal bending of glaciers based on linear...

  16. 1984 Deer Harvest Summary for Holla Bend National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This memo summarizes the 1985 deer harvest for Holla Bend National Wildlife Refuge. Tables summarize numerical findings, including bucks, does, and points.

  17. Computational Strategies for the Architectural Design of Bending Active Structures

    DEFF Research Database (Denmark)

    Tamke, Martin; Nicholas, Paul

    2013-01-01

    Active bending introduces a new level of integration into the design of architectural structures, and opens up new complexities for the architectural design process. In particular, the introduction of material variation reconfigures the design space. Through the precise specification...... of their stiffness, it is possible to control and pre-calibrate the bending behaviour of a composite element. This material capacity challenges architecture’s existing methods for design, specification and prediction. In this paper, we demonstrate how architects might connect the designed nature of composites...... with the design of bending-active structures, through computational strategies. We report three built structures that develop architecturally oriented design methods for bending-active systems using composite materials. These projects demonstrate the application and limits of the introduction of advanced...

  18. Bending elastic moduli of lipid bilayers : modulation by solutes

    OpenAIRE

    Duwe, H.P.; Kaes, J.; Sackmann, E.

    1990-01-01

    We present high precision measurements of the bending elastic moduli for bilayers of a variety of different lipids and of modifications of the flexural rigidity by solutes. The measurements are based on the Fourier analysis of thermally excited membrane undulations (vesicle shape fluctuations) using a recently developed dynamic image processing method. Measurements of the bending modulus as a function of the undulation wave vector provide information on the limitation of the excitations by th...

  19. An Analysis of Elasto-Plastic Bending of Rectangular Plate

    OpenAIRE

    Matsuda, Hiroshi; Sakiyama, Takeshi

    1988-01-01

    In this paper, a discrete method for analyzing the problem of elasto-plastic bending of a rectangular plate is proposed. The solutions for partial differential equation of rectangular plate are obtained in discrete forms by applying numerical integnltion. An incremental variable elasticity procedure has been used for the clasta-plastic analysis of the rectangular plate. As the applications of the proposed method, clasta-plastic bending of rectangular plate with four types of boundary conditio...

  20. Stress Analysis of a Secondary-Bending Specimen

    Science.gov (United States)

    1993-11-01

    Control Office Ansett Airlines of Australia, Library 0 Qantas Airways Limited Hawker de Havilland Aust Pty Ltd, Victoria, Library Hawker de Havilland...MELBOURNE, VICTORIA Technical Note 58 STRESS ANALYSIS OF A SECONDARY-BENDING SPECIMEN 0 by R.L. EVANS M. HELLER Approved for public release C) COMMONWEALTH...AND TECHNOLOGY ORGANISATION AERONAUTICAL RESEARCH LABORATORY Technical Note 58 0 STRESS ANALYSIS OF A SECONDARY-BENDING SPECIMEN by R.L. EVANS 0 M

  1. NUMERICAL SIMULATION FOR LASER BENDING OF SHEET METAL

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The new flexible forming technique of sheet metal-laser bending process is numerically simulated by using finite element method of large elastic-plastic deformation. The temperature fields and stress-strain distribution in deformation area are calculated, forming process is described and relationship between bend angle and width of sheet is discussed. It is shown that the calculated values are in good accordance with the experiments.

  2. Localized bending fatigue behavior of high-strength steel monostrands

    DEFF Research Database (Denmark)

    Winkler, Jan; Fischer, Gregor; Georgakis, Christos T.

    2012-01-01

    In this paper, the localized bending fatigue behavior of pretensioned high strength steel monostrands is investigated. Furthermore, a new methodology using an optical photogrammetry system, which can quantify surface deformations on the strand is presented. The system allows measurement of the st......In this paper, the localized bending fatigue behavior of pretensioned high strength steel monostrands is investigated. Furthermore, a new methodology using an optical photogrammetry system, which can quantify surface deformations on the strand is presented. The system allows measurement...

  3. [Preoperative information for paediatric patients. The anaesthesiologist's point of view].

    Science.gov (United States)

    Orliaguet, G

    2006-04-01

    Medical information is mandatory before any medical procedure, including pediatric anesthesia. Preoperative information covers many aspects, including medico-psychologic and judicial aspects. When the patient is a child, information must be delivered to the parents in priority. However, the French law has given a particular attention to the opinion of the child. In 70% of the cases, preoperative anxiety of the parents is more related to anesthesia than to the surgical procedure itself. We have to explain the most frequent adverse effects, as well as the more severe and well known complications to the parents, even though they are very infrequent. The only cases where preoperative information is not required are: emergency cases and refusal of the patient or the parents to be informed. While information is necessarily oral, it may be completed using a written document. The quality of the preoperative information directly influences the quality of the psychological preoperative preparation of the parents, and thereafter of the child. Preoperative preparation programs have been developed, but controversial results have been observed. The great majority of the studies on preoperative programs were performed in the USA, where the demand for preoperative information is very important. It is far from sure that the results of all these studies may be extrapolated to French parents, and French studies are needed.

  4. The role of anxiolytic premedication in reducing preoperative anxiety.

    LENUS (Irish Health Repository)

    Carroll, Jennifer K

    2012-01-01

    Prevention of preoperative anxiety with anxiolytic premedication is associated with improved preoperative outcomes in surgical patients. The objective of the authors\\' study was to evaluate the percentage of surgical patients that are prescribed premedication for preoperative anxiety before their anticipated surgical procedure. A prospective study was carried out by theatre nursing staff in the theatre reception bay of a university teaching hospital. A questionnaire was designed to record the number of patients that described symptoms consistent with preoperative anxiety. The number of patients that had been offered anxiolytic premedication for preoperative anxiety was also recorded. Consent was obtained from 115 consecutive surgical patients (male, n=52; female, n=63). Of these, 66% (n=76) reported anxiety before their surgical procedure (male: n=27, female: n=49). Premedication with a low-dose benzodiazepine was prescribed by an anaesthetist in 4% of cases (n=5). Patients that received premedication preoperatively reported effective relief of their anxiety symptoms This study demonstrates that preoperative patient anxiety is highly prevalent. The authors\\' findings suggest that premedication with anxiolytic pharmacological therapy may be an underused therapeutic resource for managing preoperative patient anxiety.

  5. Preoperative distress predicts persistent pain after breast cancer treatment

    DEFF Research Database (Denmark)

    Mejdahl, Mathias Kvist; Mertz, Birgitte Goldschmidt; Bidstrup, Pernille Envold Hansen;

    2015-01-01

    at the Department of Breast Surgery, Rigshospitalet, Denmark, were invited to participate in the study. Patients filled out a questionnaire preoperatively, and 4 and 8 months after surgery. Preoperative distress was measured with the Distress Thermometer (DT; 11-point scale, 0-10). We examined the association...

  6. Long-term effects of a preoperative smoking cessation programme

    DEFF Research Database (Denmark)

    Villebro, Nete Munk; Pedersen, Tom; Møller, Ann M;

    2008-01-01

    Preoperative smoking intervention programmes reduce post-operative complications in smokers. Little is known about the long-term effect upon smoking cessation.......Preoperative smoking intervention programmes reduce post-operative complications in smokers. Little is known about the long-term effect upon smoking cessation....

  7. A cylindrical standing wave ultrasonic motor using bending vibration transducer.

    Science.gov (United States)

    Liu, Yingxiang; Chen, Weishan; Liu, Junkao; Shi, Shengjun

    2011-07-01

    A cylindrical standing wave ultrasonic motor using bending vibration transducer was proposed in this paper. The proposed stator contains a cylinder and a bending vibration transducer. The two combining sites between the cylinder and the transducer locate at the adjacent wave loops of bending vibration of the transducer and have a distance that equal to the half wave length of bending standing wave excited in the cylinder. Thus, the bending mode of the cylinder can be excited by the bending vibration of the transducer. Two circular cone type rotors are pressed in contact to the end rims of the teeth, and the preload between the rotors and stator is accomplished by a spring and nut system. The working principle of the proposed motor was analyzed. The motion trajectories of teeth were deduced. The stator was designed and analyzed with FEM. A prototype motor was fabricated and measured. Typical output of the prototype is no-load speed of 165rpm and maximum torque of 0.45Nm at an exciting voltage of 200V(rms).

  8. Tunable characteristics of bending resonance frequency in magnetoelectric laminated composites

    Institute of Scientific and Technical Information of China (English)

    Chen Lei; Li Ping; Wen Yu-Mei; Zhu Yong

    2013-01-01

    As the magnetoelectric (ME) effect in piezoelectric/magnetostrictive laminated composites is mediated by mechanical deformation,the ME effect is significantly enhanced in the vicinity of resonance frequency.The bending resonance frequency (fr) of bilayered Terfenol-D/PZT (MP) laminated composites is studied,and our analysis predicts that (i) the bending resonance frequency of an MP laminated composite can be tuned by an applied dc magnetic bias (Hdc) due to the △E effect; (ii) the bending resonance frequency of the MP laminated composite can be controlled by incorporating FeCuNbSiB layers with different thicknesses.The experimental results show that with Hdc increasing from 0Oe (1 Oe=79.5775 A/m)to 700 Oe,the bending resonance frequency can be shifted in a range of 32.68 kHz ≤ fr ≤ 33.96 kHz.In addition,with the thickness of the FeCuNbSiB layer increasing from 0 μm to 90 μm,the bending resonance frequency of the MP laminated composite gradually increases from 33.66 kHz to 39.18 kHz.This study offers a method of adjusting the strength of dc magnetic bias or the thicknesses of the FeCuNbSiB layer to tune the bending resonance frequency for ME composite,which plays a guiding role in the ME composite design for real applications.

  9. Optimal Orthogonal Graph Drawing with Convex Bend Costs

    CERN Document Server

    Bläsius, Thomas; Wagner, Dorothea

    2012-01-01

    Traditionally, the quality of orthogonal planar drawings is quantified by either the total number of bends, or the maximum number of bends per edge. However, this neglects that in typical applications, edges have varying importance. Moreover, as bend minimization over all planar embeddings is NP-hard, most approaches focus on a fixed planar embedding. We consider the problem OptimalFlexDraw that is defined as follows. Given a planar graph G on n vertices with maximum degree 4 and for each edge e a cost function cost_e : N_0 --> R defining costs depending on the number of bends on e, compute an orthogonal drawing of G of minimum cost. Note that this optimizes over all planar embeddings of the input graphs, and the cost functions allow fine-grained control on the bends of edges. In this generality OptimalFlexDraw is NP-hard. We show that it can be solved efficiently if 1) the cost function of each edge is convex and 2) the first bend on each edge does not cause any cost (which is a condition similar to the posi...

  10. Effect of acupressure on preoperative anxiety: a clinical trial.

    Science.gov (United States)

    Valiee, Sina; Bassampour, Shiva Sadat; Nasrabadi, Alireza Nikbakht; Pouresmaeil, Zahra; Mehran, Abbas

    2012-08-01

    Preoperative anxiety, as an emotional reaction, is common among patients undergoing surgery. The purpose of this study was to examine the effect of acupressure on preoperative anxiety before abdominal surgery. The 70 subjects of this clinical trial were randomly assigned into the acupressure group (n=35), which received acupressure at the true points, or the placebo group (n=35), which received acupressure at sham (false) points. Preoperative anxiety and vital signs before and after the intervention were measured in both groups. The findings demonstrated a reduction in the level of preoperative anxiety for both groups (Pacupressure group (Pacupressure at true points (third eye and Shen men) can reduce higher preoperative anxiety of patients before abdominal surgery and that it has had a more clinically beneficial effect than sham points.

  11. Finite element simulation of laser tube bending: Effect of scanning schemes on bending angle, distortions and stress distribution

    Science.gov (United States)

    Safdar, Shakeel; Li, Lin; Sheikh, M. A.; Zhu Liu

    2007-09-01

    Laser forming has received considerable attention in recent years. Within laser forming, tube bending is an important industrial activity, with applications in critical engineering systems like micro-machines, heat exchangers, hydraulic systems, boilers, etc. Laser tube bending utilizes the thermal stresses generated during laser scanning to achieve the desired bends. The parameters to control the process are usually laser power, beam diameter, scanning velocity and number of scans. Recently axial scanning has been used for tube bending instead of commonly used circumferential scans. However the comparison between the scanning schemes has involved dissimilar laser beam geometries with circular beam used for circumferential scanning and a rectangular beam for the axial scan. Thermal stresses generated during laser scanning are strongly dependent upon laser beam geometry and scanning direction and hence it is difficult to isolate the contribution made by these two variables. It has recently been established at the Corrosion and Protection Centre, University of Manchester, that corrosion properties of material during laser forming are affected by the number of laser passes. Depending on the material, the corrosion behaviour is either adversely or favourably affected by number of passes. Thus it is of great importance to know how different scanning schemes would affect laser tube bending. Moreover, any scanning scheme which results in greater bending angle would eliminate the need for higher number of passes, making the process faster. However, it is not only the bending angle which is critical, distortions in other planes are also extremely important. Depending on the use of the final product, unwanted distortions may be the final selection criteria. This paper investigates the effect of scanning direction on laser tube bending. Finite-element modelling has been used for the study of the process with some results also validated by experiments.

  12. New strategies for preoperative skin antisepsis.

    Science.gov (United States)

    Ulmer, Miriam; Lademann, Juergen; Patzelt, Alexa; Knorr, Fanny; Kramer, Axel; Koburger, Torsten; Assadian, Ojan; Daeschlein, Georg; Lange-Asschenfeldt, Bernhard

    2014-01-01

    During the past decades, encouraging progress has been made in the prevention of surgical site infections (SSI). However, as SSI still occur today, strategic prevention measures such as standardized skin antisepsis must be implemented and rigorously promoted. Recent discoveries in skin physiology necessitate the development of novel antiseptic agents and procedures in order to ameliorate their efficacy. In particular, alternate target structures in the skin need to be taken into consideration for the development of the next generation of antiseptics. Recent investigations have shown that a high number of microorganisms are located within and in the close vicinity of the hair follicles. This suggests that these structures are an important reservoir of bacterial growth and activity in human skin. To date, it has not been fully elucidated to what extent conventional liquid antiseptics sufficiently target the hair follicle-related microbial population. Modern technologies such as tissue-tolerable plasma (TTP) have been tested for their potential antiseptic efficiency by reducing the bacterial load in the skin and in the hair follicles. First experiments using liposomes to deliver antiseptics into the hair follicles have been evaluated for their potential clinical application. The present review evaluates these two innovative methods for their efficacy and applicability in preoperative skin antiseptics.

  13. Preoperative optimization of the vascular surgery patient

    Directory of Open Access Journals (Sweden)

    Zhan HT

    2015-07-01

    Full Text Available Henry T Zhan,1 Seth T Purcell,1,2 Ruth L Bush1 1Texas A&M Health Science Center College of Medicine, Bryan, 2Baylor Scott and White, Temple, TX, USA Abstract: It is well known that patients who suffer from peripheral (noncardiac vascular disease often have coexisting atherosclerotic diseases of the heart. This may leave the patients susceptible to major adverse cardiac events, including death, myocardial infarction, unstable angina, and pulmonary edema, during the perioperative time period, in addition to the many other complications they may sustain as they undergo vascular surgery procedures, regardless of whether the procedure is performed as an open or endovascular modality. As these patients are at particularly high risk, up to 16% in published studies, for postoperative cardiac complications, many proposals and algorithms for perioperative optimization have been suggested and studied in the literature. Moreover, in patients with recent coronary stents, the risk of noncardiac surgery on adverse cardiac events is incremental in the first 6 months following stent implantation. Just as postoperative management of patients is vital to the outcome of a patient, preoperative assessment and optimization may reduce, and possibly completely alleviate, the risks of major postoperative complications, as well as assist in the decision-making process regarding the appropriate surgical and anesthetic management. This review article addresses several tools and therapies that treating physicians may employ to medically optimize a patient before they undergo noncardiac vascular surgery. Keywords: perioperative care, intraoperative care, medical management, risk evaluation/stratification, medical treatment

  14. Thoracic wall reconstruction using ultrasound images to model/bend the thoracic prosthesis for correction of pectus excavatum

    Science.gov (United States)

    Fonseca, João Gomes; Moreira, Antonio H. J.; Rodrigues, Pedro L.; Fonseca, Jaime C.; Pinho, A. C. M.; Correia-Pinto, Jorge; Rodrigues, Nuno F.; Vilaça, João L.

    2012-03-01

    Pectus excavatum is the most common congenital deformity of the anterior thoracic wall. The surgical correction of such deformity, using Nuss procedure, consists in the placement of a personalized convex prosthesis into sub-sternal position to correct the deformity. The aim of this work is the CT-scan substitution by ultrasound imaging for the pre-operative diagnosis and pre-modeling of the prosthesis, in order to avoid patient radiation exposure. To accomplish this, ultrasound images are acquired along an axial plane, followed by a rigid registration method to obtain the spatial transformation between subsequent images. These images are overlapped to reconstruct an axial plane equivalent to a CT-slice. A phantom was used to conduct preliminary experiments and the achieved results were compared with the corresponding CT-data, showing that the proposed methodology can be capable to create a valid approximation of the anterior thoracic wall, which can be used to model/bend the prosthesis.

  15. Improving bending stress in spur gears using asymmetric gears and shape optimization

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2010-01-01

    Bending stress plays a significant role in gear design wherein its magnitude is controlled by the nominal bending stress and the stress concentration due to the geometrical shape. The bending stress is indirectly related to shape changes made to the cutting tool. This work shows that the bending...

  16. Recognition and management of preoperative risk.

    Science.gov (United States)

    Nierman, E; Zakrzewski, K

    1999-08-01

    Internists are frequently asked to do preoperative consultations and to manage perioperative complications. Realistic goals are to identify patient factors that increase the risk of surgery, to quantify this risk in order to make decisions about the appropriateness of and timing of the surgery, to provide recommendations on how to minimize the risk, to identify and manage coexisting medical conditions and their associated medication requirements, to monitor the patient for perioperative problems, and to make recommendations to deal with these problems when they occur. With few exceptions, nonselective imaging and laboratory screening tests have repeatedly been shown to be of little value when the history and physical do not suggest a problem. The risk associated with the planned surgery can be estimated, with the most common serious complications being cardiac events. Updated versions of Goldman's risk indices are particularly helpful for this. Clinical variables are optimally combined with selective stress testing to discern which patients will benefit from preoperative revascularization. This has been studied best in the setting of vascular surgery. A critical guiding principle is that the value of revascularization must be judged in terms of long term gains rather than just immediate perioperative benefit. Other interventions include the selective use of beta blockers, adequate analgesia for all, control of hypertension, and appropriate volume management, especially in the settings of preexisting CHF or valvular disease. It must also be recognized that perioperative ischemia and CHF often present atypically. An approach that combines aspects of both the ACC/AHA and the ACP guidelines seems optimal. A variety of noncardiac issues must also be addressed. Postoperative pulmonary complications are common, especially with preexisting pulmonary disease, thoracic and upper abdominal surgery, and obesity. PFTs and ABGs are indicated in selected patients. Stopping

  17. Advances and Trends on Tube Bending Forming Technologies

    Institute of Scientific and Technical Information of China (English)

    YANG He; LI Heng; ZHANG Zhiyong; ZHAN Mei; LIU Jing; LI Guangjun

    2012-01-01

    As one kind of key components with enormous quantities and diversities,the bent tube parts satisfy the increasing needs for lightweight and high-strength product from both materials and structure aspects.The bent tubes have been widely used in many high-end industries such as aviation,aerospaee,shipbuilding,automobile,energy and health care.The tube bending has become one of the key manufacturing technologies for lightweight product forming.Via the analysis of bending characteristics and multiple defects,advances on exploring the common issues in tube bending are summarized regarding wrinkling instability at the intrados,wall thinning (cracking) at the extrados,springback phenomenon,cross-section deformation,forming limit and process/tooling design/optimization.Some currently developed bending techniques are reviewed in terms of their advantages and limitations.Finally,in view of the urgent requirements of high-performance complex bent tube components with difficult-to-deform and lightweight materials in aviation and aerospace fields,the development trends and corresponding challenges are presented for realizing the precise and high-efficiency tube bending deformation.

  18. Hysteresis of the resonance frequency of magnetostrictive bending cantilevers

    Science.gov (United States)

    Löffler, Michael; Kremer, Ramona; Sutor, Alexander; Lerch, Reinhard

    2015-05-01

    Magnetostrictive bending cantilevers are applicable for wirelessly measuring physical quantities such as pressure and strain. Exploiting the ΔE-effect, the resonance frequency of the cantilevers is shifted because of a change in the magnetic biasing field. The biasing field, in turn, depends on the applied pressure or strain, respectively. With a view to the application as a reliable sensor, maximum sensitivity but minimum hysteresis in the biasing field/resonance frequency dependence is preferred. In this contribution, monomorph bending cantilevers fabricated using magnetostrictive Fe49Co49V2 and Metglas 2605SA1 are investigated regarding their applicability for future sensors. For this purpose, the biasing field-dependent polarization of the magnetostrictive materials and bending of the cantilevers are determined. Furthermore, a setup to magnetically bias the cantilevers and determine the bending resonance frequency is presented. Here, the resonance frequency is identified by measuring the impulse response employing a laser Doppler vibrometer. The measurement results reveal that cantilevers made of Fe49Co49V2 possess a distinct hysteretic behaviour at low magnetic biasing field magnitudes. This is ascribed to the polarization and bending hysteresis. Cantilevers fabricated using Metglas 2605SA1 feature a lower resonance frequency shift compared to cantilevers with Fe49Co49V2, which would result in a lower sensitivity of the sensor. However, their resonance frequency hysteresis is almost negligible.

  19. Investigation of span-chordwise bending anisotropy of honeybee forewings

    Directory of Open Access Journals (Sweden)

    JianGuo Ning

    2017-05-01

    Full Text Available In this study, the spanwise and chordwise bending stiffness EI of honeybee forewings were measured by a cantilevered bending test. The test results indicate that the spanwise EI of the forewing is two orders of magnitude larger than the chordwise EI. Three structural aspects result in this span-chordwise bending anisotropy: the distribution of resilin patches, the corrugation along the span and the leading edge vein of the venation. It was found that flexion lines formed by resilin patches revealed through fluorescence microscopy promoted the chordwise bending of the forewing during flapping flight. Furthermore, the corrugation of the wing and leading edge veins of the venation, revealed by micro-computed tomography, determines the relatively greater spanwise EI of the forewing. The span-chordwise anisotropy exerts positive structural and aerodynamic influences on the wing. In summary, this study potentially assists researchers in understanding the bending characteristics of insect wings and might be an important reference for the design and manufacture of bio-inspired wings for flapping micro aerial vehicles.

  20. Bending moment of galvanized iron glass fiber sandwich panel

    Directory of Open Access Journals (Sweden)

    Gurustal Somnath Swamy

    2016-05-01

    Full Text Available The main objective of this project is to prepare a laminated with Galvanized iron thickness fractions, fiber volume fractions and orientation in the layers of GF were fabricated by hand lay-up method and evaluated for their bending moment properties of the sandwich panel using universal testing machine. This paper theoretically calculates the bending behavior of sandwich panel. The recent need to develop a new range of materials has resulted in the development of high performance lightweight composites with excellent properties. Metal– composite systems consist of alternating layers of metal and fiber-reinforced polymer composites which are bonded by an adhesive. Sandwich beams were tested under Air Bending. Stress-strain and stress-displacement were recorded by using AIMIL UTM. The beam face sheets exhibited a softening non-linearity on the bending side. Experimental results were in good agreement with predictions from simple models. On an overall basis, the sandwich panel exhibited better bending moment performance than the monolithic galvanized iron

  1. Photomechanical Energy Conversion of Photoresponsive Fibers Exhibiting Bending Behavior

    Directory of Open Access Journals (Sweden)

    Kazuya Nakata

    2012-01-01

    Full Text Available Photoresponsive fibers based on poly(acrylamide (PAA with methylene blue (MB dye were prepared. All semicircular fibers show bending towards the direction of the flat surface of the fiber when illuminated. The fibers recover their initial shape when the illumination stops. The fiber is heated upon illumination and cooled to room temperature once the illumination is stopped. The fiber also is sensitive to humidity, showing bending behavior towards the direction of the flat surface of the fiber upon changing the humidity. The mechanical energy of the PAA/MB fiber is approximately 0.6 mN for the bending direction when it is illuminated. A possible mechanism for the bending behavior is as follow: (1 the fiber is heated upon illumination because of the photothermal effect, (2 the fiber loses water molecules, (3 the fiber shrinks; bending towards the direction of the flat surface of the fiber occurs because of a difference in the shrinkage for the flat surface and the other side of the fiber. Finally, we demonstrated that a PP ball (1.5 mg can be moved by the mechanical energy produced by the changing shape of the fiber upon illumination.

  2. Curvature optical fiber sensor by using bend enhanced method

    Institute of Scientific and Technical Information of China (English)

    Jianrong ZHANG; Hairong LIU; Xinkun WU

    2009-01-01

    Deflection curvature measurement can offer a number of advantages compared with the well-established strain measurement alternative. It is able to measure thin structure; fiber has no resistance with force, which leads to a high precision. There are many kinds of curvature gauges with different operation principles. A low-cost curvature optical fiber sensor using bend enhanced method to improve its curvature measurement sensitivity was devel-oped in recent years. This sensor can distinguish between convex bending and concave bending and has a good linearity in measuring large curvature deformation. Whisper gallery ray theory and Monte Carlo simulation are new achievements by computer experiment. The operation mechanism of this curvature optical fiber sensor is presented based on light scattering theory. The attenuation is ascribed to the transmission mode changing by the curvature of the fiber, which affects the attenuation of the surface scattering. The mathematical model of relationship among light loss, bending curvature, surface roughness, and parameters of the fiber's configuration is also presented. We design different kinds of shapes of sensitive zones; each zone has different parameters. Through detecting their output optical attenuations in different curvatures and fitting the results by exponential decaying functions, the proposed model is demonstrated by experimental results. Also, we compare the experi-mental results with the theoretical analysis and discuss the sensitivity dependence on bending direction.

  3. Anterior mediastinal paraganglioma: A case for preoperative embolization

    Directory of Open Access Journals (Sweden)

    Shakir Murtaza

    2012-07-01

    Full Text Available Abstract Background Paraganglioma is a rare but highly vascular tumor of the anterior mediastinum. Surgical resection is a challenge owing to the close proximity to vital structures including the heart, trachea and great vessels. Preoperative embolization has been reported once to facilitate surgical treatment. Case presentation We report a case of anterior mediastinal paraganglioma that was embolized preoperatively, and was resected without the need for cardiopulmonary bypass and without major bleeding complications. Conclusion We make a case to further the role of preoperative embolization in the treatment of mediastinal paragangliomas.

  4. Pre-operative investigations: yield and conformity to national guidelines.

    Science.gov (United States)

    Juliana, H; Lim, T A; Inbasegaran, K

    2003-03-01

    Routine ordering of pre-operative investigations yields a low true positive rate and is not cost effective. In this study, case notes of 251 adults who underwent elective surgery were reviewed. Pre-operative investigations were classified as 'indicated' or 'not indicated', based on the national guidelines. Only 56% of all tests done were indicated. The overall rates of expected and unexpected abnormal values from pre-operative blood investigations were 51.1% and 34.4% respectively. This study found that selective testing based on guidelines was beneficial. However, the results also suggest that the local guidelines need to be reviewed.

  5. Preoperative factors influencing success in pterygium surgery

    Directory of Open Access Journals (Sweden)

    Torres-Gimeno Ana

    2012-08-01

    Full Text Available Abstract Background To identify preoperative, perioperative and postoperative risk factors that influence the success of pterygium surgery. Methods This is a prospective study of thirty-six patients with primary or recurrent pterygia. A detailed anamnesis and an ophthalmological examination were performed looking for the following factors: age, race, latitude and altitude of the main place of residence, hours of exposure to the sun, use of protective measures against UV-radiation, classification of pterygium, width of the pterygium at limbus, surgical technique (conjunctival autograft plus suturing versus tissue glue, graft alterations (misapposition, granuloma, haemorrhage, oedema, retraction or necrosis, and postoperative symptoms (foreign-body sensation, pain. The examinations were performed 2 and 7 days and 2, 6 and 12 months after surgery. In addition, recurrence was defined as any growth of conjunctiva into the cornea. Results A logistic regression and a survival analysis have been used to perform data analysis. A total number of 36 patients completed a one year follow-up. A total of 13 patients were born and lived in Spain, and 26 came from other countries, mostly Latin America. A total number of 8 males (no women presented a recurrence, mainly between 2 and 6 months. The hours of sun exposure through their life was independently related to surgical success. Pterygia of less than 5 mm of base width showed a weak positive correlation with recurrence. None of the other factors considered were significantly related to recurrence. Conclusions Male gender and high sun exposure are strongly and independently related to surgical success after the removal of pterygia.

  6. [Spectrum and susceptibility of preoperative conjunctival bacteria].

    Science.gov (United States)

    Fernández-Rubio, M E; Cuesta-Rodríguez, T; Urcelay-Segura, J L; Cortés-Valdés, C

    2013-12-01

    To describe the conjunctival bacterial spectrum of our patients undergoing intraocular surgery and their antibiotic sensitivity during the study period. A retrospective study of preoperative conjunctival culture of patients consecutively scheduled for intraocular surgery from 21 February 2011 to 1 April 2013. Specimens were directly seeded onto blood-agar and MacConkey-agar (aerobiosis incubation, 2 days), and on chocolate-agar (6% CO2 incubation, 7 days). The identified bacteria were divided into 3 groups according to their origin; the bacteria susceptibility tests were performed on those more pathogenic and on some of the less pathogenic when more than 5 colonies were isolated. The sensitivity of the exigent growing bacteria was obtained with disk diffusion technique, and for of the non-exigent bacteria by determining their minimum inhibitory concentration. The Epidat 3.1 program was used for statistical calculations. A total of 13,203 bacteria were identified in 6,051 cultures, with 88.7% being typical colonizers of conjunctiva (group 1), 8.8% typical of airways (group 2), and the remaining 2.5% of undetermined origin (group 3). 530 cultures (8.8%) were sterile. The sensitivity of group 1 was: 99% vancomycin, 95% rifampicin, 87% chloramphenicol, 76% tetracycline. Levels of co-trimoxazole, aminoglycosides, quinolones, β-lactams and macrolides decreased since 2007. The group 2 was very sensitive to chloramphenicol, cefuroxime, rifampicin, ciprofloxacin and amoxicillin/clavulanate. In group 3, to levofloxacin 93%, ciprofloxacin 89%, tobramycin 76%, but ceftazidime 53% and cefuroxime 29% decreased. None of the tested antibiotics could eradicate all possible conjunctival bacteria. Bacteria living permanently on the conjunctiva (group 1) have achieved higher resistance than the eventual colonizers. Copyright © 2013 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

  7. Effect of bend separation distance on the mass transfer in back-to-back pipe bends arranged in a 180° configuration

    Science.gov (United States)

    Chen, X.; Le, T.; Ewing, D.; Ching, C. Y.

    2016-12-01

    The mass transfer to turbulent flow through back-to-back pipe bends arranged in a 180° configuration with different lengths of pipe between the bends was measured using a dissolving gypsum test section in water. The measurements were performed for bends with a radius of curvature of 1.5 times the pipe diameter ( D) at a Reynolds numbers of 70,000 and Schmidt number of 1280. The maximum mass transfer in the bends decreased from approximately 1.8 times the mass transfer in the upstream pipe when there was no separation distance between the bends to 1.7 times when there was a 1 D or 5 D length of pipe between the bends. The location of the maximum mass transfer was on the inner sidewall downstream of the second bend when there was no separation distance between the bends. This location changed to the inner wall at the beginning of the second bend when there was a 1 D long pipe between the bends, and to the inner sidewall at the end of the first bend when there was a 5 D long pipe between the bends.

  8. Photomechanical Bending of Azobenzene-Based Photochromic Molecular Fibers

    Directory of Open Access Journals (Sweden)

    Riku Matsui

    2013-03-01

    Full Text Available Microfibers composed of azobenzene-based photochromic amorphous molecular materials, namely low molecular-mass photochromic materials with a glass-forming property, could be fabricated. These fibers were found to exhibit mechanical bending motion upon irradiation with a laser beam. In addition, the bending direction could be controlled by altering the polarization direction of the irradiated light without changing the position of the light source or the wavelength of the light. In-situ fluorescence observation of mass transport induced at the surface of the fiber doped with CdSe quantum dots suggested that the bending motions were related with the photoinduced mass transport taking place near the irradiated surface of the fiber.

  9. Flow resistance of ice slurry in bends and elbow pipes

    Science.gov (United States)

    Niezgoda-Żelasko, B.; Żelasko, J.

    2014-08-01

    The present paper covers the flow of ice slurry made of a 10.6% ethanol solution through small-radius bends and elbow pipes. The paper presents the results of experimental research on the flow resistances of Bingham-fluid ice slurry in bends and elbows. The research, performed for three pipe diameters and a relative bend radius of 1<=D/di<=2, has made it possible to take into consideration the influence of friction resistances as well the of the flow geometry on the total local resistance coefficients. The study attempts to make the local resistance coefficient dependent on the Dean number defined for a generalized Reynolds number according to Metzner-Reade

  10. Platonic scattering cancellation for bending waves in a thin plate

    KAUST Repository

    Farhat, Mohamed

    2014-04-10

    We propose an ultra-thin elastic cloak to control the scattering of bending waves in isotropic heterogeneous thin plates. The cloak design makes use of the scattering cancellation technique applied, for the first time, to the biharmonic operator describing the propagation of bending waves in thin plates. We first analyze scattering from hard and soft cylindrical objects in the quasistatic limit, then we prove that the scattering of bending waves from an object in the near and far-field regions can be suppressed significantly by covering it with a suitably designed coating. Beyond camouflaging, these findings may have potential applications in protection of buildings from earthquakes and isolating structures from vibrations in the motor vehicle industry.

  11. Segmental Bridges under Combined Torsion, Bending and Shear

    Institute of Scientific and Technical Information of China (English)

    黄真; 刘西拉

    2003-01-01

    Segmental bridges with unbonded prestressed tendons have some advantages, such as the weather independence and the corrosion protection of prestressing tendons. This paper analyzed the behavior of a prestressed segmental bridge with unbonded tendons under combined loading of torsion, bending and shear. According to the experiment research, a modified skew bending model was developed to calculate the bearing capacity of segmental bridges subjected to combined bending, shear and torsion. The finite element method was used to investigate the deflection behaviors of such structure, also to check the theoretical model. The theoretical and FEM research resuits were compared favorably with the test results from Technical University of Braunschweig, Germany. Finally, suggestion for the design and construction of segmental bridges with external prestressing was made.

  12. Longitudinal-bending mode micromotor using multilayer piezoelectric actuator.

    Science.gov (United States)

    Yao, K; Koc, B; Uchino, K

    2001-07-01

    Longitudinal-bending mode ultrasonic motors with a diameter of 3 mm were fabricated using stacked multilayer piezoelectric actuators, which were self-developed from hard lead zirconate titanate (PZT) ceramic. A bending vibration was converted from a longitudinal vibration with a longitudinal-bending coupler. The motors could be bidirectionally operated by changing driving frequency. Their starting and braking torque were analyzed based on the transient velocity response. With a load of moment of inertia 2.5 x 10(-7) kgm2, the motor showed a maximum starting torque of 127.5 microNm. The braking torque proved to be a constant independent on the motor's driving conditions and was roughly equivalent to the maximum starting torque achievable with our micromotors.

  13. Strain localization and damage development in 2060 alloy during bending

    Institute of Scientific and Technical Information of China (English)

    Xiao Jin; Bao-qin Fu; Cheng-lu Zhang; Wei Liu

    2015-01-01

    The microstructure evolution and damage development of the third-generation Al–Li alloy 2060 (T8) were studied using in situ bending tests. Specimens were loaded with a series of punches of different radii, and the microstructure evolution was studied by scanning electron microscopy, electron backscatter diffraction, and digital image correlation (DIC) methods. The evolution of the microscopic fracture strain distribution and microstructure in 2060 alloy during bending was characterized, where the dispersion distribution of precipitates was recorded by backscattered electron imaging and later inputted into a DIC system for strain calculations. The experimental results showed that strain localization in the free surface of bent specimens induced damage to the microstructure. The region of crack initiation lies on the free surface with maximum strain, and the shear crack propagates along the macro-shear band in the early stages of bending. Crack propagation in the later stages was interpreted on the basis of the conventional mechanism of ductile fracture.

  14. Bend-twist coupling potential of wind turbine blades

    DEFF Research Database (Denmark)

    Fedorov, Vladimir; Berggreen, Christian

    2014-01-01

    In the present study an evaluation of the potential for bend-twist coupling effects in wind turbine blades is addressed. A method for evaluation of the coupling magnitude based on the results of finite element modeling and full-field displacement measurements obtained by experiments is developed...... and tested on small-scale coupled composite beams. In the proposed method the coupling coefficient for a generic beam is introduced based on the Euler-Bernoulli beam formulation. By applying the developed method for analysis of a commercial wind turbine blade structure it is demonstrated that a bend......-twist coupling magnitude of up to 0.2 is feasible to achieve in the baseline blade structure made of glass-fiber reinforced plastics. Further, by substituting the glass-fibers with carbon-fibers the coupling effect can be increased to 0.4. Additionally, the effect of introduction of bend-twist coupling...

  15. Demonstration of acoustic waveguiding and tight bending in phononic crystals

    Science.gov (United States)

    Ghasemi Baboly, M.; Raza, A.; Brady, J.; Reinke, C. M.; Leseman, Z. C.; El-Kady, I.

    2016-10-01

    The systematic design, fabrication, and characterization of an isolated, single-mode, 90° bend phononic crystal (PnC) waveguide are presented. A PnC consisting of a 2D square array of circular air holes in an aluminum substrate is used, and waveguides are created by introducing a line defect in the PnC lattice. A high transmission coefficient is observed (-1 dB) for the straight sections of the waveguide, and an overall 2.3 dB transmission loss is observed (a transmission coefficient of 76%) for the 90° bend. Further optimization of the structure may yield higher transmission efficiencies. This manuscript shows the complete design process for an engineered 90° bend PnC waveguide from inception to experimental demonstration.

  16. Elastocapillary instability under partial wetting conditions: bending versus buckling

    CERN Document Server

    Andreotti, Bruno; Das, Siddhartha; Snoeijer, Jacco H

    2011-01-01

    The elastocapillary instability of a flexible plate plunged in a liquid bath is analysed theoretically. We show that the plate can bend due to two separate destabilizing mechanisms, when the liquid is partially wetting the solid. For contact angles $\\theta_e > \\pi/2$, the capillary forces acting tangential to the surface are compressing the plate and can induce a classical buckling instability. However, a second mechanism appears due to capillary forces normal to surface. These induce a destabilizing torque that tends to bend the plate for any value of the contact angle $\\theta_e > 0$. We denote these mechanisms as "buckling" and "bending" respectively and identify the two corresponding dimensionless parameters that govern the elastocapillary stability. The onset of instability is determined analytically and the different bifurcation scenarios are worked out for experimentally relevant conditions.

  17. Modulated liquid-crystal phases induced by polarity: Twist-bend, splay-bend, and blue phases

    Science.gov (United States)

    Selinger, Jonathan; Shamid, Shaikh; Allender, David

    2014-03-01

    Nematic liquid crystals exhibit flexoelectric couplings between polar order and gradients in the director field. When the couplings become strong enough, the uniform nematic phase can become unstable to the formation of a modulated polar phase. The question is then: What is the structure of the modulated polar phase? Classic work by Meyer and further studies by Dozov predicted two possible structures, known as twist-bend and splay-bend. One of these predictions, the twist-bend phase, has recently been identified in experiments on bent-core liquid crystals. Here, we investigate modulated polar phases through a combination of Landau theory and lattice simulations. We find a range of possibilities, including the twist-bend and splay-bend phases as well as polar blue phases, with 2D or 3D modulations of the director field and the polar order. We compare these polar blue phases with chiral blue phases, and discuss opportunities for observing them experimentally. Supported by NSF DMR-1106014.

  18. Ramifications of structural deformations on collapse loads of critically cracked pipe bends under in-plane bending and internal pressure

    Energy Technology Data Exchange (ETDEWEB)

    Sasidharan, Sumesh; Arunachalam, Veerappan; Subramaniam, Shanmugam [Dept. of Mechanical Engineering, National Institute of Technology, Tiruchirappalli (India)

    2017-02-15

    Finite-element analysis based on elastic-perfectly plastic material was conducted to examine the influence of structural deformations on collapse loads of circumferential through-wall critically cracked 90 .deg. pipe bends undergoing in-plane closing bending and internal pressure. The critical crack is defined for a through-wall circumferential crack at the extrados with a subtended angle below which there is no weakening effect on collapse moment of elbows subjected to in-plane closing bending. Elliptical and semioval cross sections were postulated at the bend regions and compared. Twice-elastic-slope method was utilized to obtain the collapse loads. Structural deformations, namely, ovality and thinning, were each varied from 0% to 20% in steps of 5% and the normalized internal pressure was varied from 0.2 to 0.6. Results indicate that elliptic cross sections were suitable for pipe ratios 5 and 10, whereas for pipe ratio 20, semioval cross sections gave satisfactory solutions. The effect of ovality on collapse loads is significant, although it cancelled out at a certain value of applied internal pressure. Thinning had a negligible effect on collapse loads of bends with crack geometries considered.

  19. Bending of the looping heart: differential growth revisited.

    Science.gov (United States)

    Shi, Yunfei; Yao, Jiang; Xu, Gang; Taber, Larry A

    2014-08-01

    In the early embryo, the primitive heart tube (HT) undergoes the morphogenetic process of c-looping as it bends and twists into a c-shaped tube. Despite intensive study for nearly a century, the physical forces that drive looping remain poorly understood. This is especially true for the bending component, which is the focus of this paper. For decades, experimental measurements of mitotic rates had seemingly eliminated differential growth as the cause of HT bending, as it has commonly been thought that the heart grows almost exclusively via hyperplasia before birth and hypertrophy after birth. Recently published data, however, suggests that hypertrophic growth may play a role in looping. To test this idea, we developed finite-element models that include regionally measured changes in myocardial volume over the HT. First, models based on idealized cylindrical geometry were used to simulate the bending process in isolated hearts, which bend without the complicating effects of external loads. With the number of free parameters in the model reduced to the extent possible, stress and strain distributions were compared to those measured in embryonic chick hearts that were isolated and cultured for 24 h. The results show that differential growth alone yields results that agree reasonably well with the trends in our data, but adding active changes in myocardial cell shape provides closer quantitative agreement with stress measurements. Next, the estimated parameters were extrapolated to a model based on realistic 3D geometry reconstructed from images of an actual chick heart. This model yields similar results and captures quite well the basic morphology of the looped heart. Overall, our study suggests that differential hypertrophic growth in the myocardium (MY) is the primary cause of the bending component of c-looping, with other mechanisms possibly playing lesser roles.

  20. Preoperative physical therapy for elective cardiac surgery patients

    NARCIS (Netherlands)

    Hulzebos, E.H.J.; Smit, Y.; Helders, P.P.J.M.; Meeteren, N.L.U. van

    2012-01-01

    BACKGROUND: After cardiac surgery, physical therapy is a routine procedure delivered with the aim of preventing postoperative pulmonary complications. OBJECTIVES: To determine if preoperative physical therapy with an exercise component can prevent postoperative pulmonary complications in cardiac sur

  1. An audit of documented preoperative evaluation of surgery patients ...

    African Journals Online (AJOL)

    Southern African Journal of Anaesthesia and Analgesia 2015; 21(4):23-28 ... The information obtained from the standardised PAR form in each patient's file was audited using a ... inadequate preoperative assessment and management were.

  2. Preoperative preparation of patients with pituitary gland disorders

    National Research Council Canada - National Science Library

    Malenković, Vesna; Gvozdenović, Ljiljana; Milaković, Branko; Sabljak, Vera; Ladjević, Nebojsa; Zivaljević, Vladan

    2011-01-01

    This paper presents the most common disorders of pituitary function: acromegaly, hypopituitarism, diabetes insipidus and syndrome similar to diabetes insipidus, in terms of their importance in preoperative preparation of patients...

  3. Preoperative assessment and optimization in periampullary and pancreatic cancer

    Directory of Open Access Journals (Sweden)

    S Myatra

    2011-01-01

    Full Text Available Perioperative management of pancreatic and periampullary cancer poses a considerable challenge to the pancreatic surgeon, anesthesiologist, and the intensive care team. The preoperative surgical evaluation of a pancreatic lesion aims to define the nature of the lesion (malignant or benign, stage the tumor, and to determine resectability or other non-surgical treatment options. Patients are often elderly and may have significant comorbidities and malnutrition. Obstructive jaundice may lead to coagulopathy, infection, renal dysfunction, and adverse outcomes. Routine preoperative biliary drainage can result in higher complication rates, and metal stents may be preferred over plastic stents in selected patients with resectable disease. Judicious use of antibiotics and maintaining fluid volume preoperatively can reduce the incidence of infection and renal dysfunction, respectively. Perioperative fluid therapy with hemodynamic optimization using minimally invasive monitoring may help improve outcomes. Careful patient selection, appropriate preoperative evaluation and optimization can greatly contribute to a favorable outcome after major pancreatic resections.

  4. Association of Preoperative Anemia With Postoperative Mortality in Neonates.

    Science.gov (United States)

    Goobie, Susan M; Faraoni, David; Zurakowski, David; DiNardo, James A

    2016-09-01

    Neonates undergoing noncardiac surgery are at risk for adverse outcomes. Preoperative anemia is a strong independent risk factor for postoperative mortality in adults. To our knowledge, this association has not been investigated in the neonatal population. To assess the association between preoperative anemia and postoperative mortality in neonates undergoing noncardiac surgery in a large sample of US hospitals. Using data from the 2012 and 2013 pediatric databases of the American College of Surgeons National Surgical Quality Improvement Program, we conducted a retrospective study of neonates undergoing noncardiac surgery. Analysis of the data took place between June 2015 and December 2015. All neonates (0-30 days old) with a recorded preoperative hematocrit value were included. Anemia defined as hematocrit level of less than 40%. Receiver operating characteristics analysis was used to assess the association between preoperative hematocrit and mortality, and the Youden J Index was used to determine the specific hematocrit cutoff point to define anemia in the neonatal population. Demographic and postoperative outcomes variables were compared between anemic and nonanemic neonates. Univariate and multivariable logistic regression analyses were used to determine factors associated with postoperative neonatal mortality. An external validation was performed using the 2014 American College of Surgeons National Surgical Quality Improvement Program database. Neonates accounted for 2764 children (6%) in the 2012-2013 American College of Surgeons National Surgical Quality Improvement Program databases. Neonates inlcuded in the study were predominately male (64.5%), white (66.3%), and term (69.9% greater than 36 weeks' gestation) and weighed more than 2 kg (85.0%). Postoperative in-hospital mortality was 3.4% in neonates and 0.6% in all age groups (0-18 years). A preoperative hematocrit level of less than 40% was the optimal cutoff (Youden) to predict in-hospital mortality

  5. Proteomic Analysis of Fruit Bending in Cucumber (Cucumis sativus L.)

    Institute of Scientific and Technical Information of China (English)

    WANG Li-li; ZHANG Peng; QIN Zhi-wei; ZHOU Xiu-yan

    2014-01-01

    In cucumber, fruit shape is an important quality criterion, and fruit bending is known to limit growth, yield, and taste. To investigate the post-transcriptional changes that regulate fruit bending and to better understand the underlying molecular mechanisms, we generated a proteomic proifle of the abdomen and back of cucumber bending fruit. Two-dimensional gel electrophoresis (2-DE) allowed the detection of approximately 900 distinct protein spots in each gel, 32 of which were differentially expressed in the abdomen and back of bending cucumber fruit. Ten of the differentially expressed proteins were analyzed using matrix-assisted laser ionization time of lfight mass spectrometry (MALDI-TOF/MS). A search of primary databases showed that the identiifed proteins are involved in various metabolic processes and cellular responses, including photosynthesis metabolism, energy metabolism, defense and stress response, and regulation. The identiifed proteins included large subunits of ribulose-1,5-bisphosphate carboxylase/oxygenase, which are involved in photosynthesis and photorespiratory metabolism, and isocitrate dehydrogenase, which is involved in the tricarboxylic acid cycle. It is possible that imbalances in catabolic and anabolic processes directly affect the bending of cucumber fruit. The predicted function of the cobalamin-independent methionine synthase isozyme is closely related to ethylene biosynthesis; fruit bending may be regulated by ethylene, or by ethylene signaling crosstalk during fruit development. The 14-3-3 protein is usually considered to be a regulation-related protein, which plays a role in regulating cell hyperplasia, cell differentiation during growth, and apoptosis during senescence. Involvement of guanosine triphosphate (GTP)-binding proteins in signal transmission is known to regulate the development of cells in cucumber fruits and to play a role in fruit shape variation. Patterns of protein expression showed high repeatability. We hypothesize

  6. Enhanced resolution of long-period grating bend sensor

    DEFF Research Database (Denmark)

    Glavind, Lars; Gao, S; Cook, K

    2013-01-01

    We present an optical fiber bend sensor with enhanced resolution based on the principle of a Mach-Zehnder interferometer in transmission. The sensor is based on two identical Long-Period Gratings separated by approximately 100 mm in a D-shaped single-mode optical fiber. The sensor provides a narr...... resonance bandwidth compared to a typical resonance from a Long-Period Grating. The sensor was recoated with low refractive index polyimide and embedded on a fiber-glass base plate before it was characterized as a bending sensor....

  7. Bending Mechanical Behavior of Polyester Matrix Reinforced with Fique Fiber

    Science.gov (United States)

    Altoé, Giulio Rodrigues; Netto, Pedro Amoy; Barcelos, Mariana; Gomes, André; Margem, Frederico Muylaert; Monteiro, Sergio Neves

    Environmentally correct composites, made from natural fibers, are among the most investigated and applied today. In this paper, we investigate the mechanical behavior of polyester matrix composites reinforced with continuous fique fibers, through bending tensile tests. Specimens containing 0, 10, 20 and 30% in volume of fique fiber were aligned along the entire length of a mold to create plates of these composites, those plates were cut following the ASTM standard to obtained bending tests specimens. The test was conducted in a Instron Machine and the fractured specimens were analyzed by SEM, the results showed the increase in the materials tensile properties with the increase of fiber amount.

  8. Quasimolecular Dynamic Simulation for Bending Fracture of Laminar Composite Materials

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Recently, quasimolecular dynamics has been successfully used to simulate the deformation characteristics of actual size solid materials. In quasimolecular dynamics, which is an attempt to bridge the gap between atomistic and continuum simulations, molecules are aggregated into large units, called quasimolecules, to evaluate large scale material behavior. In this paper, a 2-dimensional numerical simulation using quasimolecular dynamics was performed to investigate laminar composite material fractures and crack propagation behavior in the uniform bending of laminar composite materials. It was verified that under bending deformation laminar composite materials deform quite differently from homogeneous materials

  9. Elastostatic bending of a bimaterial plate with a circular interface

    Science.gov (United States)

    Ogbonna, Nkem

    2015-08-01

    The elastostatic bending of an arbitrarily loaded bimaterial plate with a circular interface is analysed. It is shown that the deflections in the composite solid are directly related to the deflection in the corresponding homogeneous material by integral and differential operators. It is further shown that, by a simple transformation of elastic constants, the Airy stress function induced in the composite by a stretching singularity can be deduced from the deflection induced by a bending singularity. This result is significant for reduction of mathematical labour and for systematic construction of solutions for more complex structures with circular geometry.

  10. Effects of rim thickness on spur gear bending stress

    Science.gov (United States)

    Bibel, G. D.; Reddy, S. K.; Savage, M.; Handschuh, R. F.

    1991-01-01

    Thin rim gears find application in high-power, light-weight aircraft transmissions. Bending stresses in thin rim spur gear tooth fillets and root areas differ from the stresses in solid gears due to rim deformations. Rim thickness is a significant design parameter for these gears. To study this parameter, a finite element analysis was conducted on a segment of a thin rim gear. The rim thickness was varied and the location and magnitude of the maximum bending stresses reported. Design limits are discussed and compared with the results of other researchers.

  11. Origin of bending in uncoated microcantilever - Surface topography?

    Energy Technology Data Exchange (ETDEWEB)

    Lakshmoji, K.; Prabakar, K.; Tripura Sundari, S., E-mail: sundari@igcar.gov.in; Jayapandian, J.; Tyagi, A. K.; Sundar, C. S. [Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)

    2014-01-27

    We provide direct experimental evidence to show that difference in surface topography on opposite sides of an uncoated microcantilever induces bending, upon exposure to water molecules. Examination on opposite sides of the microcantilever by atomic force microscopy reveals the presence of localized surface features on one side, which renders the induced stress non-uniform. Further, the root mean square inclination angle characterizing the surface topography shows a difference of 73° between the opposite sides. The absence of deflection in another uncoated microcantilever having similar surface topography confirms that in former microcantilever bending is indeed induced by differences in surface topography.

  12. Flagella bending affects macroscopic properties of bacterial suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Potomkin, M.; Tournus, M.; Berlyand, L. V.; Aranson, I. S.

    2017-05-01

    To survive in harsh conditions, motile bacteria swim in complex environments and respond to the surrounding flow. Here, we develop a mathematical model describing how flagella bending affects macroscopic properties of bacterial suspensions. First, we show how the flagella bending contributes to the decrease in the effective viscosity observed in dilute suspension. Our results do not impose tumbling (random reorientation) as was previously done to explain the viscosity reduction. Second, we demonstrate how a bacterium escapes from wall entrapment due to the self-induced buckling of flagella. Our results shed light on the role of flexible bacterial flagella in interactions of bacteria with shear flow and walls or obstacles.

  13. A randomized trial of preoperative oral carbohydrates in abdominal surgery

    OpenAIRE

    Sada, Fatos; Krasniqi, Avdyl; Hamza, Astrit; Gecaj-Gashi, Agreta; Bicaj, Besnik; Kavaja, Floren

    2014-01-01

    Background Carbohydrate-rich liquid drinks (CRLDs) have been recommended to attenuate insulin resistance by shortening the preoperative fasting interval. The aim of our study the effect of preoperative oral administration of CRLDs on the well-being and clinical status of patients. Methods A randomized, double blind, prospective study of patients undergoing open colorectal operations (CR) and open cholecyctectomy (CH) was conducted. Patients were divided into three groups: study, placebo, and ...

  14. Preoperative prediction model of outcome after cholecystectomy for symptomatic gallstones

    DEFF Research Database (Denmark)

    Borly, L; Anderson, I B; Bardram, Linda

    1999-01-01

    BACKGROUND: After cholecystectomy for symptomatic gallstone disease 20%-30% of the patients continue to have abdominal pain. The aim of this study was to investigate whether preoperative variables could predict the symptomatic outcome after cholecystectomy. METHODS: One hundred and two patients...... and sonography evaluated gallbladder motility, gallstones, and gallbladder volume. Preoperative variables in patients with or without postcholecystectomy pain were compared statistically, and significant variables were combined in a logistic regression model to predict the postoperative outcome. RESULTS: Eighty...

  15. Preoperative Nutritional Status of the Surgical Patients in Jeju

    OpenAIRE

    Moon, Myung-Sang; Kim, Sung-Soo; Lee, Sang-Yup; Jeon, Dal-Jae; Yoon, Min-Geun; Kim, Sung-Sim; Moon, Hanlim

    2014-01-01

    Background To assess the preoperative nutritional status of patients with various disorders and to provide data for pre- and postoperative patient management plans, particularly in the elderly. There is no published information on age-matched and disease-matched preoperative nutritional/immunologic status for orthopedic patients, especially in the elderly, in Jeju. Methods In total, 331 patients with four categories of orthopedic conditions were assessed: 92 elective surgery patients, 59 arth...

  16. [Value of preoperative planning in total hip arthroplasty].

    Science.gov (United States)

    De Thomasson, E; Mazel, C; Guingand, O; Terracher, R

    2002-05-01

    Preoperative planning enables an assessment of the size of the implants needed before total hip replacement. Eggli and Müller demonstrated the reproduciblity of preoperative planning but did not evaluate its contribution to reducing limb length discrepancy. As femur lateralization and the position of the prosthetic center of rotation affect joint mechanics, it would be useful to assess their contribution to the efficacy of preoperative planning. We reviewed the files of 57 patients who underwent total hip arthroplasty for primary joint degeneration or necrosis limited to one hip. The healthy hip served as a control. The surgical plan was elaborated from the preoperative pelvis x-rays (AP and lateral views) and anatomic measurements on films obtained three months postoperatively. In 49 cases, preoperative planning predicted a restoration of the normal anatomy of the operated hip (center of rotation, femur lateralization, length of the operated limb). This objective was achieved in only 22.5% of the cases. Femur lateralization was the most difficult objective to achieve (59.2%). Equal limb length and good position of the center of rotation was achieved in 70% of the cases. For eight patients (14%) preoperative planning was not satisfactory, the implant offset not being adapted to the patient's anatomy. There are limits to preoperative planning, particularly for restitution of adequate femur lateralization. This difficulty appears to be related to three factors: inadequate adaptation of the implant to hip anatomy (14% of the cases in our experience), stiff rotation in degenerative hips inhibiting proper assessment of the length of the femoral neck, and relative imprecision of operative evaluation of femoral anteversion affecting femur lateralization and the level of the femoral cut. Although imperfect, preoperative planning is, in our opinion, essential before total hip arthroplasty in order to avoid major positioning errors and operative difficulties.

  17. Essential elements of the preoperative breast reconstruction evaluation

    OpenAIRE

    Cheng, Angela; Losken, Albert

    2015-01-01

    A plethora of options exist for breast reconstruction and preoperative evaluation must be thorough to lead to a successful outcome. We review multiple components of the preoperative assessment including the patient’s history, goals, imaging, and key elements of the physical exam. Consideration for tumor biology, staging, need or response to chemotherapy or radiation therapy is important in deciding on immediate versus delayed reconstruction. It is also important to consider the patient’s anat...

  18. Preoperative PET/CT in early-stage breast cancer

    DEFF Research Database (Denmark)

    Bernsdorf, M; Berthelsen, A K; Wielenga, V T;

    2012-01-01

    The aim of this study was to assess the diagnostic and therapeutic impact of preoperative positron emission tomography and computed tomography (PET/CT) in the initial staging of patients with early-stage breast cancer.......The aim of this study was to assess the diagnostic and therapeutic impact of preoperative positron emission tomography and computed tomography (PET/CT) in the initial staging of patients with early-stage breast cancer....

  19. Preoperative Chemoradiotheraph for Inflammatory Breast Cancer

    Institute of Scientific and Technical Information of China (English)

    Hongbo Ren; Qi Wang; Yaoxiong Yan; Shaolin Li; Biyou Huang

    2006-01-01

    OBJECTIVE To observe the effect of preoperative chemoradiotherapy for inflammatory breast cancer.METHODS From December 1996 to December 2000, we received and treated 21 patients with inflammatory breast carcinoma with a combinedmodality treatment. The chemotherapy protocol consisted of cyclophosphamide (CTX), pirarubicin (THP-ADM) and 5-fluorouracil (5-FU) or CTX, 5-Fu and methotrexate (MTX). The same infusion scheme was repeated on day 21. After 3~4 cycles the patients were treated with radiotherapy. When the radiation dose reached 40 Gy, the patients who were unable or unwilling to under go an operation received continued radiotherapy. When the radiation dose to the supra clavicular fossa and internal mammary lymph nodes reached 60 Gy and 50 Gy respectively, the radiotherapy was stopped. Chemotherapy was then continued with the original scheme. Patients who had indications for surgery and were willing to under go an operation received no treatment for 2 weeks, after which a total mastectomy was performed. Chemotherapy and radiotherapy was resumed with the original scheme after the operations. When the radiation dose reached 50 Gy, radiotherapy was stopped.RESULTS All patients were followed-up for more than 5 years with a follow-up rate of 100%. The overall 3 and 5-year survival rates of these patients were 42.9%, and 23.8% respectively. For patients in Stage ⅢB the 3 and 5-year survival rates were 50.0% and 27.8% respectively, and for patients in Stage Ⅳ, the 3 and 5-year survival rates were both 0.0%.There was a significant difference between the 2 stage groups (P<0.05,X2=11.60). For patients who received an operation, the 3 and 5-year survival rates were 80.0% and 33.3% respectively, For patients who were not treated with an operation, the 3 and 5-year survival rates were both0.0%, There was a significant difference between the operated and nonoperated groups (P<0.05, X2=11.64).CONCLUSION The prognosis of inflammatory breast carcinoma is poor

  20. Preoperative Planning of Orthopedic Procedures using Digitalized Software Systems.

    Science.gov (United States)

    Steinberg, Ely L; Segev, Eitan; Drexler, Michael; Ben-Tov, Tomer; Nimrod, Snir

    2016-06-01

    The progression from standard celluloid films to digitalized technology led to the development of new software programs to fulfill the needs of preoperative planning. We describe here preoperative digitalized programs and the variety of conditions for which those programs can be used to facilitate preparation for surgery. A PubMed search using the keywords "digitalized software programs," "preoperative planning" and "total joint arthroplasty" was performed for all studies regarding preoperative planning of orthopedic procedures that were published from 1989 to 2014 in English. Digitalized software programs are enabled to import and export all picture archiving communication system (PACS) files (i.e., X-rays, computerized tomograms, magnetic resonance images) from either the local working station or from any remote PACS. Two-dimension (2D) and 3D CT scans were found to be reliable tools with a high preoperative predicting accuracy for implants. The short learning curve, user-friendly features, accurate prediction of implant size, decreased implant stocks and low-cost maintenance makes digitalized software programs an attractive tool in preoperative planning of total joint replacement, fracture fixation, limb deformity repair and pediatric skeletal disorders.

  1. The importance of preoperative diagnosis of blister aneurysms.

    Science.gov (United States)

    Russin, Jonathan J; Kramer, Daniel R; Thomas, Debi; Hasson, Denise; Liu, Charles Y; Amar, Arun P; Mack, William J; Giannotta, Steven L

    2015-09-01

    We describe a series of 14 surgical blister aneurysm (BA) patients and compare outcomes in those with known cerebral BA to those lacking preoperative BA diagnosis/recognition. BA are broad, fragile, pathologic dilatations of the intracranial arteries. They have a low prevalence but are associated with substantially higher surgical morbidity and mortality rates than saccular aneurysms. A confirmed, preoperative BA diagnosis can alter operative management and technique. We performed a retrospective review of prospectively collected data on aneurysm patients undergoing surgery at a major academic institution. All patients from 1990 to 2011 with a postoperative BA diagnosis were included. Chart reviews were performed to identify patients with preoperative BA diagnoses and collect descriptive data. We identified 14 patients, 12 of whom presented with subarachnoid hemorrhage. The age of the cohort (mean ± standard deviation: 41.8 ± 13.9 years) was lower than that generally reported for saccular aneurysm populations. Preoperatively diagnosed BA had an intraoperative rupture (IOR) rate of 28.6% (2/7) compared to a 57.1% (4/7) rate in the undiagnosed patients. The mortality rate in the preoperatively diagnosed cohort was 14.3% (1/7) while that of the undiagnosed group was 42.8% (3/7). BA remain a diagnostic and treatment challenge with morbidity and mortality rates exceeding those of saccular aneurysms. Preoperative BA diagnosis may decrease IOR and mortality rates and improve patient outcomes.

  2. Evaluating the effects of preoperative fasting and fluid limitation.

    Science.gov (United States)

    Tosun, Betül; Yava, Ayla; Açıkel, Cengizhan

    2015-04-01

    The aim of the study was to evaluate the effects of preoperative fasting and fluid limitation in patients undergoing laparoscopic cholecystectomy. Although traditional long-term fasting is not recommended in current preoperative guidelines, this is still a common intervention. Visual analogue scale was used to assess hunger, thirst, sleepiness, exhaustion, nausea and pain; State and Trait Anxiety Inventory was used to assess the preoperative anxiety of 99 patients undergoing elective laparoscopic cholecystectomy. Mean time of preoperative fasting and fluid limitation were, respectively, 14.70 ± 3.14 and 11.25 ± 3.74 h. Preoperatively, 58.60% of the patients experienced moderate anxiety. Patients fasting 12 h or longer had higher hunger, thirst, nausea and pain scores. The mean trait anxiety score of patients fasting 12 h or longer was statistically significantly higher. Receiving nothing by mouth after midnight preoperatively is a persisted intervention and results in discomfort of patients. Clinical protocols should be revised and nurses should be trained in current fasting protocols. © 2014 Wiley Publishing Asia Pty Ltd.

  3. Bending-induced mode non-degeneracy and coupling in chalcogenide negative curvature fibers.

    Science.gov (United States)

    Wei, Chengli; Menyuk, Curtis R; Hu, Jonathan

    2016-05-30

    We study bend loss in chalcogenide negative curvature fibers with different polarizations, different tube wall thicknesses, and different bend directions relative to the mode polarization. The coupling between the core mode and tube modes induces bend loss peaks in the two non-degenerate modes at the same bend radius. There is as much as a factor of 28 difference between the losses of the two polarization modes. The fiber with a larger tube wall thickness, corresponding to a smaller inner tube diameter, can sustain a smaller bend radius. The bend loss is sensitive to the bend direction when coupling occurs between the core mode and tube modes. A bend loss of 0.2 dB/m at a bend radius of 16 cm, corresponding to 0.2 dB/turn, can be achieved in a chalcogenide negative curvature fiber.

  4. Thin-walled aluminum alloy tube NC precision bending based on finite element simulation

    Institute of Scientific and Technical Information of China (English)

    GU Rui-jie; YANG He; ZHAN Mei; LI Heng

    2006-01-01

    Elongation and springback are the bottleneck problems of thin-walled aluminum alloy tube NC precision bending. So thin-walled aluminum alloy tube NC precision bending based on finite element simulation is put forward. The finite element model of thin-walled aluminum alloy tube NC bending is established based on the DYNAFORM platform. The process of thin-walled aluminum alloy tube NC precision bending is simulated with the model and the elongation and springback of tube bending can be is put forward and the computing equations of bending angle, bending radius, blanking length and initial bending section based on elongation and springback angle are derived. The bending angle, bending radius, blanking length and initial bending section of tube bending can be gained with these equations based on the elongation and springback angle from the simulation. The study can be used to control the quality of thin-walled aluminum alloy tube NC bending so that precision bending without redundance can be realized.

  5. METHOD TO CALCULATE BENDING CENTER AND STRESS INTENSITY FACTORS OF CRACKED CYLINDER UNDER SAINT-VENANT BENDING

    Institute of Scientific and Technical Information of China (English)

    汤任基; 汤昕燕

    2001-01-01

    Using the single crack solution and the regular solution of plane harmonic function, the problem of Saint-Venant bending of a cracked cylinder by a transverse force was reduced to solving two sets of integral equations and its general solution was then obtained. Based on the obtained solution, a method to calculate the bending center and the stress intensity factors of the cracked cylinger whose cross-section is not thin-walled, but of small torsion rigidity is proposed. Some numerical examples are given.

  6. An anaesthetic pre-operative assessment clinic reduces pre-operative inpatient stay in patients requiring major vascular surgery.

    LENUS (Irish Health Repository)

    O'Connor, D B

    2012-02-01

    BACKGROUND: Patients undergoing major vascular surgery (MVS) require extensive anaesthetic assessment. This can require extended pre-operative stays. AIMS: We investigated whether a newly established anaesthetic pre-operative assessment clinic (PAC) would reduce the pre-operative inpatient stay, avoid unnecessary investigations and facilitate day before surgery (DBS) admissions for patients undergoing MVS. PATIENT AND METHODS: One year following and preceding the establishment of the PAC the records of patients undergoing open or endovascular aortic aneurysm repair, carotid endarterectomy and infra-inguinal bypass were reviewed to measure pre-operative length of stay (LoS). RESULTS: Pre-operative LoS was significantly reduced in the study period (1.85 vs. 4.2 days, respectively, P < 0.0001). Only 12 out of 61 patients in 2007 were admitted on the DBS and this increased to 33 out of 63 patients (P = 0.0002). No procedure was cancelled for medical reasons. CONCLUSION: The PAC has facilitated accurate outpatient anaesthetic assessment for patients requiring MVS. The pre-operative in-patient stay has been significantly reduced.

  7. Electrical Emissions from Concrete under Three-point Bending Tests

    Institute of Scientific and Technical Information of China (English)

    LIU Qingping; SUN Mingqing; LI Zhuoqiu; LI Guoqiang

    2005-01-01

    Electrical emission(EM) signals, which are generated from the concrete specimens under three-point bending tests, were conducted. It is shown that electrical emission phenomena are related to cracking of the specimens, cohesive failure, contact-separation etc. The simultaneous appearance of electric emission signals and visible cracks during the flexure loading of beams was also observed.

  8. Secondary flow in sharp open-channel bends

    NARCIS (Netherlands)

    Blanckaert, K.; De Vriend, H.J.

    2004-01-01

    Secondary currents are a characteristic feature of flow in open-channel bends. Besides the classical helical motion (centre-region cell), a weaker and smaller counter-rotating circulation cell (outer-bank cell) is often observed near the outer bank, which is believed to play an important role in ban

  9. Photoacoustic elastic bending in thin film—Substrate system

    Energy Technology Data Exchange (ETDEWEB)

    Todorović, D. M., E-mail: dmtodor@imsi.bg.ac.rs [Institute for Multidisciplinary Research, University of Belgrade, P.O. Box 33, 11030 Belgrade (Serbia); Rabasović, M. D.; Markushev, D. D. [Institute of Physics, University of Belgrade, Pregrevica 118, 11080 Belgrade-Zemun (Serbia)

    2013-12-07

    Theoretical model for optically excited two-layer elastic plate, which includes plasmaelastic, thermoelastic, and thermodiffusion mechanisms, is given in order to study the dependence of the photoacoustic (PA) elastic bending signal on the optical, thermal, and elastic properties of thin film—substrate system. Thin film-semiconductor sample (in our case Silicon) is modeled by simultaneous analysis of the plasma, thermal, and elastic wave equations. Multireflection effects in thin film are included in theoretical model and analyzed. Relations for the amplitude and phase of electronic and thermal elastic bending in the optically excited two-layer mechanically-supported circular plate are derived. Theoretical analysis of the thermodiffusion, plasmaelastic, and thermoelastic effects in a sample-gas-microphone photoacoustic detection configuration is given. Two normalization procedures of the photoacoustic elastic bending signal in function of the modulation frequency of the optical excitation are established. Given theoretical model can be used for various photoacoustic detection configurations, for example, in the study of optical, thermal, and elastic properties of the dielectric-semiconductor or metal-semiconductor structure, etc., Theoretical analysis shows that it is possible to develop new noncontact and nondestructive experimental method—PA elastic bending method for thin film study, with possibility to obtain the optical, thermal, and elastic parameters of the film thinner than 1 μm.

  10. A Novel Rotary Piezoelectric Motor Using First Bending Hybrid Transducers

    Directory of Open Access Journals (Sweden)

    Yingxiang Liu

    2015-08-01

    Full Text Available We report a novel rotary piezoelectric motor using bending transducers in this work. Three transducers are used to drive a disk-shaped rotor together by the elliptical movements of their driving tips; these motions are produced by the hybrid of two first bending vibration modes. The proposed piezoelectric transducer has a simple structure as it only contains an aluminum alloy beam and four pieces of PZT plates. Symmetrical structure is the only necessary condition in the design process as it will ensure the resonance frequencies of the two orthogonal first bending modes are equal. Transducers with first bending resonance frequency of about 53 kHz were fabricated and assembled into a rotary motor. The proposed motor exhibits good performance on speed and torque control. Under a working frequency of 53.2 kHz, the maximum no-load speed and the maximum torque of the prototype are tested to be 53.3 rpm and of 27 mN·m.

  11. Optimization of bandwidth in 60^o photonic crystal waveguide bends

    DEFF Research Database (Denmark)

    Xing, P. F.; Borel, Peter Ingo; Frandsen, Lars Hagedorn;

    2005-01-01

    A systematic scheme utilizing 2D and 3D finite-difference time-domain calculations to design 60^o photonic crystal waveguide bends is presented. The method results in an improved transmission bandwidth from 70 to 160 nm in 2D simulations, and from 50 to 100 nm in 3D simulations. The design...

  12. Tidal bending of glaciers: a linear viscoelastic approach

    DEFF Research Database (Denmark)

    Reeh, Niels; Christensen, Erik Lintz; Mayer, Christoph

    2003-01-01

    glaciers are in the range 0.9-3 GPa. It has therefore been suggested that the elastic-beam model with a single value of E approximate to 1 GPa adequately describes tidal bending of glaciers.In contrast, laboratory experiments with ice give E =93 GPa, i.e. 3-10 times higher than the glacier-derived values...

  13. Varmebesparelser ved løbende bygningsrenovering frem til 2050

    DEFF Research Database (Denmark)

    Wittchen, Kim Bjarne; Kragh, Jesper

    Som noget relativt nyt er der i bygningsreglementet indført krav til efterisolering af bygningsdele i forbindelse med den løbende renovering, som fx udskiftning af en tagbelægning. Hvor meget påvirker det netto-varmeforbruget frem til 2050, hvis der fortsættes med de gældende regler, og hvilken e...

  14. Water-rich bending faults at the Middle America Trench

    Science.gov (United States)

    Naif, Samer; Key, Kerry; Constable, Steven; Evans, Rob L.

    2015-09-01

    The portion of the Central American margin that encompasses Nicaragua is considered to represent an end-member system where multiple lines of evidence point to a substantial flux of subducted fluids. The seafloor spreading fabric of the incoming Cocos plate is oriented parallel to the trench such that flexural bending at the outer rise optimally reactivates a dense network of normal faults that extend several kilometers into the upper mantle. Bending faults are thought to provide fluid pathways that lead to serpentinization of the upper mantle. While geophysical anomalies detected beneath the outer rise have been interpreted as broad crustal and upper mantle hydration, no observational evidence exists to confirm that bending faults behave as fluid pathways. Here we use seafloor electromagnetic data collected across the Middle America Trench (MAT) offshore of Nicaragua to create a comprehensive electrical resistivity image that illuminates the infiltration of seawater along bending faults. We quantify porosity from the resistivity with Archie's law and find that our estimates for the abyssal plain oceanic crust are in good agreement with independent observations. As the Cocos crust traverses the outer rise, the porosity of the dikes and gabbros progressively increase from 2.7% and 0.7% to 4.8% and 1.7%, peaking within 20 km of the trench axis. We conclude that the intrusive crust subducts twice as much pore water as previously thought, significantly raising the flux of fluid to the seismogenic zone and the mantle wedge.

  15. Finite element analysis of damage in pipeline bends

    NARCIS (Netherlands)

    Swart, A.E.; Karamanos, S.A.; Scarpas, A.; Blaauwendraad, J.

    2010-01-01

    The present paper describes a numerical formulation for the analysis of damage in steel pipeline bends. In particular, the numerical implementation of Gurson plasticity model is described in the framework of a special element, referred to as “tube element”. This is a three-node element, which simula

  16. Effect of train carbody's parameters on vertical bending stiffness performance

    Science.gov (United States)

    Yang, Guangwu; Wang, Changke; Xiang, Futeng; Xiao, Shoune

    2016-10-01

    Finite element analysis(FEA) and modal test are main methods to give the first-order vertical bending vibration frequency of train carbody at present, but they are inefficiency and waste plenty of time. Based on Timoshenko beam theory, the bending deformation, moment of inertia and shear deformation are considered. Carbody is divided into some parts with the same length, and it's stiffness is calculated with series principle, it's cross section area, moment of inertia and shear shape coefficient is equivalent by segment length, and the fimal corrected first-order vertical bending vibration frequency analytical formula is deduced. There are 6 simple carbodies and 1 real carbody as examples to test the formula, all analysis frequencies are very close to their FEA frequencies, and especially for the real carbody, the error between analysis and experiment frequency is 0.75%. Based on the analytic formula, sensitivity analysis of the real carbody's design parameters is done, and some main parameters are found. The series principle of carbody stiffness is introduced into Timoshenko beam theory to deduce a formula, which can estimate the first-order vertical bending vibration frequency of carbody quickly without traditional FEA method and provide a reference to design engineers.

  17. Predicting bending stiffness of randomly oriented hybrid panels

    Science.gov (United States)

    Laura Moya; William T.Y. Tze; Jerrold E. Winandy

    2010-01-01

    This study was conducted to develop a simple model to predict the bending modulus of elasticity (MOE) of randomly oriented hybrid panels. The modeling process involved three modules: the behavior of a single layer was computed by applying micromechanics equations, layer properties were adjusted for densification effects, and the entire panel was modeled as a three-...

  18. Electrical Reliability of a Film-Type Connection during Bending

    Directory of Open Access Journals (Sweden)

    Ryosuke Mitsui

    2015-10-01

    Full Text Available With the escalating demands for downsizing and functionalizing mobile electronics, flexible electronics have become an important aspect of future technologies. To address limitations concerning junction deformation, we developed a new connection method using a film-type connector that is less than 0.1 mm thick. The film-type connector is composed of an organic film substrate, a UV-curable adhesive that deforms elastically under pressure, and electrodes that are arranged on the adhesive. The film-type connection relies on a plate-to-plate contact, which ensures a sufficient contact area. The electrical reliability of the film-type connection was investigated based on changes in the resistance during bending at curvature radii of 70, 50, 25, 10, 5, and 2.5 mm. The connection was bent 1000 times to investigate the reproducibility of the connector’s bending properties. The tests showed that no disconnections occurred due to bending in the vertical direction of the electrode, but disconnections were observed due to bending in the parallel direction at curvature radii of 10, 5, and 2.5 mm. In addition, the maximum average change in resistance was less than 70 milliohms unless a disconnection was generated. These results support the application of the new film-type connection in future flexible devices.

  19. A Second Look at Brian Simon's "Bending the Rules"

    Science.gov (United States)

    Cox, Sue

    2016-01-01

    In this article the author revisits an important book: Brian Simon's "Bending the Rules: the Baker reform of education." Written by a key figure in the history of the journal FORUM as well as in the history of education, Simon's book documented the features of the Education Reform Bill of 1987 (the precursor to the Education Reform Act…

  20. Band bending and electrical transport at chemically modified silicon surfaces

    Science.gov (United States)

    Lopinski, Greg; Ward, Tim; Hul'Ko, Oleksa; Boukherroub, Rabah

    2002-03-01

    High resolution electron energy loss spectroscopy (HREELS) and electrical transport measurements have been used to investigate how various chemical modifications give rise to band bending and alter the conductivity of Si(111) surfaces. HREELS is a sensitive probe of band bending through observations of the low frequency free carrier plasmon mode. For hydrogen terminated surfaces, prepared by the standard etch in ammonium flouride, HREELS measurements on both n and n+ substrates are consistent with nearly flat bands. Chlorination of these surfaces results in substantial upward band bending due to the strong electron withdrawing nature of the chlorine, driving the surface into inversion. The presence of this inversion layer on high resistivity n-type samples is observed through a substantial enhancement of the surface conductivity (relative to the H-terminated surface), as well as through broadening of the quasi-elastic peak in the HREELS measurements. We have also begun to examine organically modified silicon surfaces, prepared by various wet chemical reactions with the H-terminated surface. Decyl modified Si(111) surfaces are seen to exhibit a small degree of band bending, attributed to extrinsic defect states cause by a small degree of oxidation accompanying the modification reaction. The prospects of using conductivity as an in-situ monitor of the rate of these reactions will be discussed.

  1. The Clinch Bend Regional Industrial Site and economic development opportunities

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    This effort focuses initially on the Clinch Bend site. Other sites and developable tracts of land are identified with the assistance of communities in proximity to Oak Ridge, the State of Tennessee, and others, and compared with the projected site requirements for large industrial facilities.

  2. A COMBINED HYBRID FINITE ELEMENT METHOD FOR PLATE BENDING PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    Tian-xiao Zhou; Xiao-ping Xie

    2003-01-01

    In this paper, a combined hybrid method is applied to finite element discretization ofplate bending problems. It is shown that the resultant schemes are stabilized, i.e., theconvergence of the schemes is independent of inf-sup conditions and any other patch test.Based on this, two new series of plate elements are proposed.

  3. Multiphase fluid structure interaction in bends and T-joints

    NARCIS (Netherlands)

    Cargnelutti, M.F.; Belfroid, S.P.C.; Schiferli, W.; Osch, M.M.E. van

    2010-01-01

    Air-water experiments were carried out in a horizontal 1" pipe system to measure the magnitude of the forces induced by the multiphase flow. Forces and accelerations were measured on a number of bends and T-joint configurations for a wide range of operating conditions. Five different configurations

  4. Multiphase fluid structure interaction in bends and T-joints

    NARCIS (Netherlands)

    Cargnelutti, M.F.; Belfroid, S.P.C.; Schiferli, W.; Osch, M.M.E. van

    2010-01-01

    Air-water experiments were carried out in a horizontal 1" pipe system to measure the magnitude of the forces induced by the multiphase flow. Forces and accelerations were measured on a number of bends and T-joint configurations for a wide range of operating conditions. Five different configurations

  5. Elastocapillary instability under partial wetting conditions: Bending versus buckling

    NARCIS (Netherlands)

    Andreotti, Bruno; Marchand, Antonin; Das, Siddhartha; Snoeijer, Jacco H.

    2011-01-01

    The elastocapillary instability of a flexible plate plunged in a liquid bath is analyzed theoretically. We show that the plate can bend due to two separate destabilizing mechanisms, when the liquid is partially wetting the solid. For contact angles θe>π/2, the capillary forces acting tangential to t

  6. High precision optical fiber alignment using tube laser bending

    NARCIS (Netherlands)

    Folkersma, Ger; Römer, Gerardus Richardus, Bernardus, Engelina; Brouwer, Dannis Michel; Herder, Justus Laurens

    2016-01-01

    In this paper, we present a method to align optical fibers within 0.2 μm of the optimal position, using tube laser bending and in situ measuring of the coupling efficiency. For near-UV wavelengths, passive alignment of the fibers with respect to the waveguides on photonic integrated circuit chips

  7. Springback prediction of three-dimensional variable curvature tube bending

    Directory of Open Access Journals (Sweden)

    Shen Zhang

    2016-03-01

    Full Text Available The springback phenomenon of tube bending occurs consequentially after unloading, which will affect the manufacturing accuracy and processing efficiency of the tubular products. In this article, the bending and springback processes of minor-diameter thick-walled tube are simulated by ABAQUS to reveal the springback laws. The springback prediction of three-dimensional variable curvature bent tube is projected on each discrete osculating and rectifying plane, and then the three-dimensional problem can be transformed into two dimensions. The mathematic relationship of the radius before and after springback in the plane is built by approximate pure bending springback experiments. The springback on such planes is transformed into three dimensions. The tube axes are merged by first-order geometric (G1 continuity and then compensated with the modified function according to the axis complexity, so as to establish mathematic analytic model for springback prediction of three-dimensional variable curvature tube bending. Finally, the feasibility, reliability, and accuracy of the model are verified by finite element method and experiments.

  8. Hydraulically controlled flexible arm can bend in any direction

    Science.gov (United States)

    Griffin, F. D.

    1966-01-01

    Arm assembly consisting of four flexible tubes controlled by a four-way hydraulic or pneumatic valve can bend in any direction. The flexible arm could be used for probing areas that cannot be reached by ordinary tools, handling hazardous materials, and for graph recording.

  9. Bend-twist coupling potential of wind turbine blades

    Science.gov (United States)

    Fedorov, V.; Berggreen, C.

    2014-06-01

    In the present study an evaluation of the potential for bend-twist coupling effects in wind turbine blades is addressed. A method for evaluation of the coupling magnitude based on the results of finite element modeling and full-field displacement measurements obtained by experiments is developed and tested on small-scale coupled composite beams. In the proposed method the coupling coefficient for a generic beam is introduced based on the Euler-Bernoulli beam formulation. By applying the developed method for analysis of a commercial wind turbine blade structure it is demonstrated that a bend-twist coupling magnitude of up to 0.2 is feasible to achieve in the baseline blade structure made of glass-fiber reinforced plastics. Further, by substituting the glass-fibers with carbon-fibers the coupling effect can be increased to 0.4. Additionally, the effect of introduction of bend-twist coupling into a blade on such important blade structural properties as bending and torsional stiffness is demonstrated.

  10. Teaching Cultural Geography with "Bend It like Beckham"

    Science.gov (United States)

    Algeo, Katie

    2007-01-01

    The British film "Bend It Like Beckham" (2002) is pedagogically useful in the cultural geography classroom for engaging students with core concepts, such as ethnicity, migration, acculturation, and assimilation, and with more advanced modes of analysis, such as the social construction of identity. Although the film depicts a particular…

  11. Ultrathin 90-degree sharp bends for spoof surface plasmon polaritons

    DEFF Research Database (Denmark)

    Yang, Yihao; Chen, Hongsheng; Xiao, Sanshui;

    2015-01-01

    surface plasmons around 90-degree sharp bends on ultrathin metallic films in the microwave regime. We demonstrate that by judiciously engineering the structure, the dispersion relation can be designed to reduce the scattering. Furthermore, the reflection can be suppressed by proper structural decoration...

  12. Photoelastic stress analysis in mitred bend under internal pressure

    Energy Technology Data Exchange (ETDEWEB)

    Sawa, Yoshiaki

    1987-12-01

    The stress analysis and stress relaxation in mitred bend subjected to internal pressure have been studied by means of the photoelastic stress freezing method. The experimental results show that stress concentration occurs in the wedge tip of the intersectional plane and it is considerably influenced by the bent angle. Then, the stress relaxation was obtained by planing the wedge tip.

  13. Prognostic significance of preoperative fibrinogen in patients with colon cancer.

    Science.gov (United States)

    Sun, Zhen-Qiang; Han, Xiao-Na; Wang, Hai-Jiang; Tang, Yong; Zhao, Ze-Liang; Qu, Yan-Li; Xu, Rui-Wei; Liu, Yan-Yan; Yu, Xian-Bo

    2014-07-14

    To investigate the prognostic significance of preoperative fibrinogen levels in colon cancer patients. A total of 255 colon cancer patients treated at the Affiliated Tumor Hospital of Xinjiang Medical University from June 1(st) 2005 to June 1(st) 2008 were enrolled in the study. All patients received radical surgery as their primary treatment method. Preoperative fibrinogen was detected by the Clauss method, and all patients were followed up after surgery. Preoperative fibrinogen measurements were correlated with a number of clinicopathological parameters using the Student t test and analysis of variance. Survival analyses were performed by the Kaplan-Meier method and Cox regression modeling to measure 5-year disease-free survival (DFS) and overall survival (OS). The mean preoperative fibrinogen concentration of all colon cancer patients was 3.17 ± 0.88 g/L. Statistically significant differences were found between preoperative fibrinogen levels and the clinicopathological parameters of age, smoking status, tumor size, tumor location, tumor-node-metastasis (TNM) stage, modified Glasgow prognostic scores (mGPS), white blood cell (WBC) count, neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and carcinoembryonic antigen (CEA) levels. Univariate survival analysis showed that TNM stage, tumor cell differentiation grade, vascular invasion, mGPS score, preoperative fibrinogen, WBC, NLR, PLR and CEA all correlated with both OS and DFS. Alpha-fetoprotein (AFP) and body mass index correlated only with OS. Kaplan-Meier analysis revealed that both OS and DFS of the total cohort, as well as of the stage II and III patients, were higher in the hypofibrinogen group compared to the hyperfibrinogen group (all P TNM stage, mGPS score, CEA, and AFP levels correlated with both OS and DFS. Preoperative fibrinogen levels can serve as an independent prognostic marker to evaluate patient response to colon cancer treatment.

  14. Preoperative psychological testing--another form of prejudice.

    Science.gov (United States)

    Ashton, David; Favretti, Franco; Segato, Gianni

    2008-10-01

    Preoperative psychological screening of bariatric surgery candidates has become routine, and a significant proportion of patients have their surgery deferred as a consequence. If psychological testing is being used as a form of preoperative triage, both patients and surgeons are entitled to know whether there is sufficient evidence to justify its use in this way. We define the argument for psychological screening as consisting of four premises (p1-p4) and a conclusion (C) as follows: (p1) A significant minority of obese patients will not be successful in losing weight following bariatric surgery-the "failure" group; (p2) A significant minority of patients will exhibit abnormal psychological profiles during preoperative testing; (p3) The majority of individuals referred to in (p2) will be found in group (p1) i.e., abnormal psychological profiles identified preoperatively predict less favorable weight loss outcomes postoperatively; (p4) Identifying patients with adverse psychological profiles preoperatively would allow either exclusion of those at high risk of failure or provide a more secure rationale for targeted pre- and postoperative support; (C) Psychological screening should be part of the routine preoperative assessment for patients undergoing obesity surgery. We reviewed the literature to find evidence to support the premises and show that (p1) can be justified but that (p2) is problematic and can only be accepted in a heavily qualified version. We find no evidence for (p3) and since (p4) and (C) are predicated on (p3), the argument clearly fails. There is no evidence to suggest that preoperative psychological screening can predict postoperative outcomes and no justification for using such testing as a means of discriminating between candidates presenting themselves for bariatric surgery.

  15. Nitric oxide mediates gravitropic bending in soybean roots.

    Science.gov (United States)

    Hu, Xiangyang; Neill, Steven J; Tang, Zhangcheng; Cai, Weiming

    2005-02-01

    Plant roots are gravitropic, detecting and responding to changes in orientation via differential growth that results in bending and reestablishment of downward growth. Recent data support the basics of the Cholodny-Went hypothesis, indicating that differential growth is due to redistribution of auxin to the lower sides of gravistimulated roots, but little is known regarding the molecular details of such effects. Here, we investigate auxin and gravity signal transduction by demonstrating that the endogenous signaling molecules nitric oxide (NO) and cGMP mediate responses to gravistimulation in primary roots of soybean (Glycine max). Horizontal orientation of soybean roots caused the accumulation of both NO and cGMP in the primary root tip. Fluorescence confocal microcopy revealed that the accumulation of NO was asymmetric, with NO concentrating in the lower side of the root. Removal of NO with an NO scavenger or inhibition of NO synthesis via NO synthase inhibitors or an inhibitor of nitrate reductase reduced both NO accumulation and gravitropic bending, indicating that NO synthesis was required for the gravitropic responses and that both NO synthase and nitrate reductase may contribute to the synthesis of the NO required. Auxin induced NO accumulation in root protoplasts and asymmetric NO accumulation in root tips. Gravistimulation, NO, and auxin also induced the accumulation of cGMP, a response inhibited by removal of NO or by inhibitors of guanylyl cyclase, compounds that also reduced gravitropic bending. Asymmetric NO accumulation and gravitropic bending were both inhibited by an auxin transport inhibitor, and the inhibition of bending was overcome by treatment with NO or 8-bromo-cGMP, a cell-permeable analog of cGMP. These data indicate that auxin-induced NO and cGMP mediate gravitropic curvature in soybean roots.

  16. Theory and algorithms to compute Helfrich bending forces: a review

    Science.gov (United States)

    Guckenberger, Achim; Gekle, Stephan

    2017-05-01

    Cell membranes are vital to shield a cell’s interior from the environment. At the same time they determine to a large extent the cell’s mechanical resistance to external forces. In recent years there has been considerable interest in the accurate computational modeling of such membranes, driven mainly by the amazing variety of shapes that red blood cells and model systems such as vesicles can assume in external flows. Given that the typical height of a membrane is only a few nanometers while the surface of the cell extends over many micrometers, physical modeling approaches mostly consider the interface as a two-dimensional elastic continuum. Here we review recent modeling efforts focusing on one of the computationally most intricate components, namely the membrane’s bending resistance. We start with a short background on the most widely used bending model due to Helfrich. While the Helfrich bending energy by itself is an extremely simple model equation, the computation of the resulting forces is far from trivial. At the heart of these difficulties lies the fact that the forces involve second order derivatives of the local surface curvature which by itself is the second derivative of the membrane geometry. We systematically derive and compare the different routes to obtain bending forces from the Helfrich energy, namely the variational approach and the thin-shell theory. While both routes lead to mathematically identical expressions, so-called linear bending models are shown to reproduce only the leading order term while higher orders differ. The main part of the review contains a description of various computational strategies which we classify into three categories: the force, the strong and the weak formulation. We finally give some examples for the application of these strategies in actual simulations.

  17. Statistical analysis of the V-tool bending process parameters in the bending of HC260Y steel

    Directory of Open Access Journals (Sweden)

    J. Cumin

    2016-04-01

    Full Text Available This paper presents statistical analysis of the parameters in the V-tool bending process of the HC260Y steel. Assessment of the mathematical model and analysis of variance (ANOVA were performed within the design of experiments. The hydraulic testing machine Amsler and the developed V-tool were used in the experiments.

  18. Ligament rupture and unstable burst behaviors of axial flaws in steam generator U-bends

    Energy Technology Data Exchange (ETDEWEB)

    Bahn, Chi Bum, E-mail: bahn@pusan.ac.kr [Pusan National University, 2 Busandaehak-ro 63 beon-gil, Geumjeong-gu, Busan 609-735 (Korea, Republic of); Oh, Young-Jin [KEPCO Engineering & Construction Co. Inc., Seongnam 463-870 (Korea, Republic of); Majumdar, Saurin [Argonne National Laboratory, Lemont, IL 60439 (United States)

    2015-11-15

    Highlights: • Ligament rupture and unstable burst pressure tests were conducted with U-bends. • In general, U-bends showed higher ligament rupture and burst pressures than straight tubes. • U-bend test data was bounded by 90% lower limit of the probabilistic models for straight tubes. • Prediction models for straight tubes could be conservatively applied to U-bends. - Abstract: Incidents of U-bend cracking in steam generator (SG) tubes have been reported, some of which have led to tube rupture. Experimental and analytical modeling efforts to determine the failure criteria of flawed SG U-bends are limited. To evaluate structural integrity of flawed U-bends, ligament rupture and unstable burst pressure tests were conducted on 57 and 152 mm bend radius U-bends with axial electrical discharge machining notches. In general, the ligament rupture and burst pressures of the U-bends were higher than those of straight tubes with similar notches. To quantitatively address the test data scatter issue, probabilistic models were introduced. All ligament rupture and burst pressures of U-bends were bounded by 90% lower limits of the probabilistic models for straight tubes. It was concluded that the prediction models for straight tubes could be applied to U-bends to conservatively evaluate the ligament rupture and burst pressures of U-bends with axial flaws.

  19. Preoperative cryotherapy use in anterior cruciate ligament reconstruction.

    Science.gov (United States)

    Koyonos, Loukas; Owsley, Kevin; Vollmer, Emily; Limpisvasti, Orr; Gambardella, Ralph

    2014-12-01

    Unrelieved postoperative pain may impair rehabilitation, compromise functional outcomes, and lead to patient dissatisfaction. Preemptive multimodal analgesic techniques may improve outcomes after surgery. We hypothesized that patients using preoperative cryotherapy plus a standardized postoperative treatment plan will have lower pain scores and require less pain medication compared with patients receiving a standardized postoperative treatment plan alone after arthroscopically assisted anterior cruciate ligament reconstruction (ACLR). A total of 53 consecutive patients undergoing arthroscopically assisted ACLR performed by one of seven surgeons were randomly assigned to one of two groups. Group 1 received no preoperative cryotherapy and group 2 received 30 to 90 minutes of preoperative cryotherapy to the operative leg using a commercial noncompressive cryotherapy unit. Visual analog scale pain scores and narcotic use were recorded for the first 4 days postoperatively. Total hours of cold therapy and continuous passive motion (CPM) use and highest degree of flexion achieved were recorded as well. Group 1 consisted of 26 patients (15 allograft Achilles tendon and 11 autograft bone patellar tendon bone [BPTB]), and group 2 consisted of 27 patients (16 allograft Achilles tendon and 11 autograft BPTB). Group 2 patients reported less pain (average 1.3 units, p cryotherapy, hours of CPM use, or maximum knee flexion achieved. Complications did not occur in either group. This is the first report we are aware of showing the postoperative effects of preoperative cryotherapy. Our results support the safety and efficacy of preoperative cryotherapy in a multimodal pain regimen for patients undergoing ACL reconstruction.

  20. Preoperative thrombocytosis predicts poor survival in patients with glioblastoma

    Science.gov (United States)

    Brockmann, Marc A.; Giese, Alf; Mueller, Kathrin; Kaba, Finjap Janvier; Lohr, Frank; Weiss, Christel; Gottschalk, Stefan; Nolte, Ingo; Leppert, Jan; Tuettenberg, Jochen; Groden, Christoph

    2007-01-01

    Thrombocytosis, which is defined as a platelet count greater than 400 platelets/nl, has been found to be an independent predictor of shorter survival in various tumors. Release of growth factors from tumors has been proposed to increase platelet counts. Preoperative platelet counts and other clinical and hematological parameters were reviewed from the records of 153 patients diagnosed between 1999 and 2004 with histologically confirmed glioblastoma in order to evaluate the prognostic significance of preoperative thrombocytosis in these patients. The relationship between thrombocytosis and survival was initially analyzed in all patients regardless of further therapy. Univariate log-rank tests showed that the median survival time of 29 patients with preoperative thrombocytosis (19%) was significantly shorter (4 months; 95% confidence interval [95% CI], 3–6 months) compared to 124 patients with normal platelet counts (11 months; 95% CI, 8–13 months; p = 0.0006). Multivariate analysis (Cox proportional hazards model) confirmed preoperative platelet count, age, prothrombin time, and activated partial thromboplastin time to be prognostic factors of survival (all p thrombocytosis was diagnosed (6 months; 95% CI, 4–12 months) compared to patients with normal platelet count (13 months; 95% CI, 11–15 months; p = 0.0359). In multivariate analysis, age, platelet count, preoperative prothrombin time, and degree of tumor resection retained significance as prognostic factors of survival (all p thrombocytosis to be a prognostic factor associated with shorter survival time in patients with glioblastoma. PMID:17504931

  1. Significance of preoperative thrombocytosis in epithelial ovarian cancer

    Directory of Open Access Journals (Sweden)

    Crasta Julian

    2010-01-01

    Full Text Available Background: Reactive thrombocytosis is reported in a variety of solid tumors. A few studies have documented preoperative thrombocytosis in ovarian cancer and identified it as a marker of aggressive tumor biology. Aim: To study the incidence of preoperative thrombocytosis (platelets greater than 400x10 in epithelial ovarian cancer and its association with other clinicopathologic factors. Materials and Methods: Sixty-five patients with invasive ovarian epithelial cancer were retrospectively reviewed and analyzed for the association preoperative thrombocytosis with other clinical and histopathological prognostic factors. Means were analyzed by Student′s t test; proportions were determined by Chi-square analysis. Results: Twenty of 65 (37.5% patients had thrombocytosis at primary diagnosis. Patients with preoperative thrombocytosis were found to have lower hemoglobin (P < 0.0002, more advanced stage disease (P < 0.05 and higher grade tumors (P < 0.02. Patients with thrombocytosis had greater likelihood of subpotimal cytoreduction. Conclusions: Preoperative thrombocytosis is a frequent finding in ovarian carcinomas and their association with advanced stage disease and higher grade denotes that platelets play a role in the tumor growth and progression.

  2. EPA Regional Administrator Highlights the Benefits of Reducing Food Waste in South Bend

    Science.gov (United States)

    (SOUTH BEND, IND. - November 5, 2015) U.S. Environmental Protection Agency Regional Administrator Susan Hedman joined South Bend Mayor Pete Buttigieg today at Ivy Tech Community College's culinary school to highlight the benefits of diverting food waste fr

  3. Novel low-loss 60° bends in photonic crystal waveguides

    DEFF Research Database (Denmark)

    Thorhauge, Morten; Frandsen, Lars Hagedorn; Borel, Peter Ingo;

    2004-01-01

    A novel type of 60 degree photonic crystal waveguide bend has been designed, simulated and fabricated in silicon-on-insulator material utilizing deep ultraviolet lithography. Loss-free bending has been observed in certain wavelength regions....

  4. Effect of preoperative biliary drainage on outcome of classical pancreaticoduodenectomy

    Institute of Scientific and Technical Information of China (English)

    Chandra Shekhar Bhati; Chandrashekhar Kubal; Pankaj Kumar Sihag; Ankur Atal Gupta; Raj Kamal Jenav; Nicholas G Inston; Jagdish M Mehta

    2007-01-01

    AIM: To investigate the role of preoperative biliary drainage (PBD) in the outcome of classical pancreaticodu odenectomy.METHODS: A 10-year retrospective data analysis was performed on patients (n = 48) undergoing pancreaticoduodenectomy from March 1994 to March 2004 in department of surgery at SMS medical college, Jaipur, India. Demographic variables, details of preoperative stenting, operative procedure and post operative complications were noted.RESULTS: Preoperative biliary drainage was performed in 21 patients (43.5%). The incidence of septic complications was significantly higher in patients with biliary stent placement (P < 0.05, 0 vs 4). This group of patients also had a significantly higher minor biliary leak rate. Mortality and hospital stay in each group was comparable.CONCLUSION: Within this study population the use of PBD by endoscopic stenting was associated with a high incidence of infective complications. These findings do not support the routine use of biliary stenting in patients prior to pancreatico-duodenectomy.

  5. Upper airway imaging and its role in preoperative airway evaluation

    Directory of Open Access Journals (Sweden)

    Jagadish G Sutagatti

    2016-01-01

    Full Text Available Ultrasonography (USG is well-known as a fast, safe, and noninvasive technique. Its application for imaging of the airway is now gaining momentum. The upper airway has a complex anatomy, and its assessment forms a vital part of every preanesthetic evaluation. Ultrasound (US imaging can help in upper airway assessment in the preoperative period. There are various approaches to upper airway USG. The technique has its own advantages, disadvantages, and limitations. This simple yet challenging imaging technique is all set to become an important part of routine preoperative airway evaluation. This article reviews the various approaches to upper airway US imaging, interpretation of the images, limitations, and disadvantages of the technique and its varied clinical applications in the preoperative period. The scientific material presented here was hand searched from textbooks and journals, electronically from PubMed, and Google scholar using text words.

  6. Pancreatic Somatostatinoma Diagnosed Preoperatively: Report of a Case

    Directory of Open Access Journals (Sweden)

    Yasuhisa Mori

    2014-01-01

    Full Text Available Context Somatostatinoma is a rare neoplasm of the pancreas. Preoperative diagnosis is often difficult. Case report We report a 72-year-old woman with a pancreatic head tumor measuring 37 mm in diameter, and enlargement of the lymphnodes on the anterior surface of the pancreatic head and the posterior surface of the horizontal part of the duodenum.Laboratory data showed an elevated plasma somatostatin concentration. Examination of a biopsy specimen of thepancreatic head mass obtained by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA showedhistopathological features of a neuroendocrine tumor. Immunohistochemical staining showed that the tumor cells werepositive for somatostatin, leading to a preoperative diagnosis of pancreatic somatostatinoma. The patient underwentpylorus-preserving pancreaticoduodenectomy. The plasma somatostatin concentration decreased progressively aftersurgery. Conclusions A rare case of pancreatic somatostatinoma with lymph node metastases was presented.Immunohistochemical analysis of a biopsy specimen obtained by EUS-FNA was useful for preoperative diagnosis.

  7. CLINICAL AND BIOLOGICAL BEHAVIOR OF NEUROGENIC TUMOR AFTER PREOPERATIVE CHEMOTHERAPY

    Institute of Scientific and Technical Information of China (English)

    Gao Jiechun; Dong Kuiran; Jing Baixiang

    1998-01-01

    Objective: To study the significance of preoperative chemotherapy for the treatment of neurogenic tumor in children. Methods: VMA, MYCN gene and DNA content of 21 cases of neuroblastoma treated with preoperative chemotherapy were studied with a control group. Results: Resection rate was 95.5%. Mean survival time was 28.1±10.2 months, which was significantly higher than the control group (8.8±6.8 months, P<0.01).Post chemotherapeutic VMA was lower. DNA index was also reduced and the percentage of cells in G0+G1 phases was elevated. The MYCN expression was suppressed.Conclusion: Preoperative chemotherapy can induce the apoptosis of neurogenic tumor cells and inhibit its proliferative activity.

  8. Indications of laparoscopic cholecystectomy based on preoperative imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Wakizaka, Yoshitaka; Sano, Syuichi; Nakanishi, Yoshimi; Koike, Yoshinobu; Ozaki, Susumu; Iwanaga, Rikizo (Sapporo City General Hospital (Japan)); Uchino, Junichi

    1994-03-01

    We studied the indications for laparoscopic cholecystectomy (LC) and values of preoperative imaging findings in 82 patients who underwent preoperative imaging diagnostic tests (abdominal echogram, abdominal CAT scan, ERCP). We analyzed mainly patients who were considered to be indicated for LC but whose gallbladders could be removed by open laparotomy, or whose gallbladders were removed by open laparotomy but were considered indicated for LC from retrospective study. We found the following results. LC could be easily performed in patients with a history of severe acute cholecystitis if they had no findings of a thickened wall or negative gallbladder signs. Abdominal echogram and CAT scan were the best preoperative imaging tests for determining the gallbladder's state, especially for obstruction of the cystic duct. These results are important today when the operative indications of LC are extremely indefinite because of the accumulation of operative experience and technological improvements. (author).

  9. Analysis of flagellar bending in hamster spermatozoa: characterization of an effective stroke.

    Science.gov (United States)

    Kinukawa, Masashi; Ohmuro, Junko; Baba, Shoji A; Murashige, Sunao; Okuno, Makoto; Nagata, Masao; Aoki, Fugaku

    2005-12-01

    The mechanism by which flagella generate the propulsive force for movement of hamster spermatozoa was analyzed quantitatively. Tracing points positioned 30, 60, 90, and 120 microm from the head-midpiece junction on the flagellum revealed that they all had zigzag trajectories. These points departed from and returned to the line that crossed the direction of progression. They moved along the concave side (but not the convex side) of the flagellar envelope that was drawn by tracing the trajectory of the entire flagellum. To clarify this asymmetry, the bending rate was analyzed by measuring the curvatures of points 30, 60, 90, and 120 microm from the head-midpiece junction. The bending rate was not constant through the cycle of flagellar bending. The rate was higher when bending was in the direction described by the curve of the hook-shaped head (defined as a principal bend [P-bend]) to the opposite side (R-bend). We measured a lower bending rate in the principal direction (R-bend to P-bend). To identify the point at which the propulsive force is generated efficiently within the cycle of flagellar bending, we calculated the propulsive force generated at each point on the flagellum. The value of the propulsive force was positive whenever the flagellum bent from an R-bend to a P-bend (when the bending rate was lowest). By contrast, the propulsive force value was zero or negative when the flagellum bent in the other direction (when the bending rate was higher). These results indicate that flagellar bending in hamster spermatozoa produces alternate effective and ineffective strokes during propulsion.

  10. The Strength of PIN-PMN-PT Single Crystals under Bending with a Longitudinal Electric Field

    Science.gov (United States)

    2011-04-06

    The strength of PIN– PMN – PT single crystals under bending with a longitudinal electric field This article has been downloaded from IOPscience. Please...COVERED 00-00-2011 to 00-00-2011 4. TITLE AND SUBTITLE The Strength Of PIN- PMN - PT Single Crystals Under Bending With A Longitudinal Electric Field... PMN ? PT ) single crystals was measured using a four point bending apparatus with a longitudinal electric field applied to the bar during bending. The

  11. Optimization of Bending Process Parameters for Seamless Tubes Using Taguchi Method and Finite Element Method

    OpenAIRE

    Jui-Chang Lin; Kingsun Lee

    2015-01-01

    The three-dimensional tube (or pipe) is manufactured by CNC tube bending machine. The key techniques are determined by tube diameter, wall thickness, material, and bending radius. The obtained technique through experience and the trial and error method is unreliable. Finite element method (FEM) simulation for the tube bending process before production can avoid wasting manpower and raw materials. The computer-aided engineering (CAE) software ABAQUS 6.12 is applied to simulate bending characte...

  12. Preoperative predictors of weight loss following bariatric surgery: systematic review.

    Science.gov (United States)

    Livhits, Masha; Mercado, Cheryl; Yermilov, Irina; Parikh, Janak A; Dutson, Erik; Mehran, Amir; Ko, Clifford Y; Gibbons, Melinda Maggard

    2012-01-01

    Obesity affects 32% of adults in the USA. Surgery generates substantial weight loss, but 20-30% fails to achieve successful weight loss. Our objective was to identify preoperative psychosocial factors associated with weight loss following bariatric surgery. We performed a literature search of PubMed® and the Cochrane Database of Reviews of Effectiveness between 1988 and April 2010. Articles were screened for bariatric surgery and weight loss if they included a preoperative predictor of weight loss: body mass index (BMI), preoperative weight loss, eating disorders, or psychiatric disorder/substance abuse. One thousand seven titles were reviewed, 534 articles screened, and 115 included in the review. Factors that may be positively associated with weight loss after surgery include mandatory preoperative weight loss (7 of 14 studies with positive association). Factors that may be negatively associated with weight loss include preoperative BMI (37 out of 62 studies with negative association), super-obesity (24 out of 33 studies), and personality disorders (7 out of 14 studies). Meta-analysis revealed a decrease of 10.1% excess weight loss (EWL) for super-obese patients (95% confidence interval (CI) [3.7-16.5%]), though there was significant heterogeneity in the meta-analysis, and an increase of 5.9% EWL for patients with binge eating at 12 months after surgery (95% CI [1.9-9.8%]). Further studies are necessary to investigate whether preoperative factors can predict a clinically meaningful difference in weight loss after bariatric surgery. The identification of predictive factors may improve patient selection and help develop interventions targeting specific needs of patients.

  13. Preoperative antibiotics for septic arthritis in children: delay in diagnosis.

    Science.gov (United States)

    MacLean, Simon B M; Timmis, Christopher; Evans, Scott; Lawniczak, Dominik; Nijran, Amit; Bache, Edward

    2015-04-01

    To review the records of 50 children who underwent open joint washout for septic arthritis with (n=25) or without (n=25) preoperative antibiotics. Records of 50 children who underwent open joint washout for presumed septic arthritis with (n=25) or without (n=25) preoperative antibiotics were reviewed. 17 boys and 8 girls aged 3 weeks to 16 years (median, 1.5 years) who were prescribed preoperative antibiotics before joint washout were compared with 12 boys and 13 girls aged one month to 14 years (median, 2 years) who were not. Following arthrotomy and washout, all patients were commenced on high-dose intravenous antibiotics. Patients were followed up for 6 to 18 months until asymptomatic. Patients who were referred from places other than our emergency department were twice as likely to have been prescribed preoperative antibiotics (p=0.0032). Patients prescribed preoperative antibiotics had a longer median (range) time from symptom onset to joint washout (8 [2-23] vs. 4 [1-29] days, p=0.05) and a higher mean erythrocyte sedimentation rate (93.1 vs. 54.3 mm/h, p=0.023) at presentation. Nonetheless, the 2 groups were comparable for weight bearing status, fever, and positive culture, as well as the mean (range) duration of antibiotic treatment (4.9 [4-7] vs. 4.7 [1-8] weeks, p=0.586). Preoperative antibiotics should be avoided in the management of septic arthritis in children. Their prescription delays diagnosis and definitive surgery, and leads to additional washouts and complications. A high index of suspicion and expedite referral to a specialist paediatric orthopaedic unit is needed if septic arthritis is suspected.

  14. Assessment of patient satisfaction with the preoperative anesthetic evaluation

    Directory of Open Access Journals (Sweden)

    Gebremedhn EG

    2014-09-01

    Full Text Available Endale Gebreegziabher Gebremedhn, Vidhya Nagaratnam Department of Anesthesia, School of Medicine, Gondar College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia Background: The evaluation of patient satisfaction is a core aspect of the continuous quality improvement in anesthesia service that can be affected by the preoperative anesthetist visit. This visit enables the anesthetist to know about the patient's general health status and the nature of surgery, to choose the type of anesthesia, and to discuss perioperative complications and their management with the patient. Patients have sometimes complained about the information given during the preoperative anesthetic evaluation in the University of Gondar teaching and referral hospital. The aim of this study was to determine the level of patient satisfaction with the preoperative anesthetist visit. Methods: A cross-sectional study was conducted from February 15 to April 15, 2013. All consecutive elective patients who were operated upon under anesthesia during the study period were interviewed 24 hours after operation. A pretested questionnaire and checklists, which were developed based on the hospital's anesthetic evaluation sheet, were used for data collection. Results: A total of 116 elective patients were operated upon under anesthesia during the study period. Of these, 102 patients were included in our study, with a response rate of 87.9%. Anesthetists introduced themselves to ~24% patients; provided information about anesthesia to ~32%, postoperative complications to ~21%, postoperative analgesia to ~18, and postoperative nausea and vomiting to ~21%; and spent adequate time with ~74%. Patients' questions were answered by the anesthetist in ~65% of cases, and ~65% of patients had reduced anxiety after the anesthetist visit. The patients' overall satisfaction with the preoperative anesthetist visit was ~65%. Conclusion and recommendation: Patient satisfaction with the

  15. Preoperative evaluation of synchronous colorectal cancer using MR colonography

    DEFF Research Database (Denmark)

    Achiam, Michael P; Andersen, Lars Peter Holst; Klein, Mads

    2009-01-01

    it is noninvasive, and most of the colon can be evaluated. Furthermore, it has higher patient acceptance, and no sedation or radiation is used. The purpose of this study was to determine the feasibility of performing MRC preoperatively in an everyday clinical situation in a group of patients who were not offered......RATIONALE AND OBJECTIVES: It is well known that synchronous cancers (incidence, 2%-11%) and polyps (incidence, 12%-58%) occur in patients with colorectal cancer. Magnetic resonance colonography (MRC) seems like the obvious choice as a diagnostic tool in preoperative evaluation, because...

  16. [Importance of preoperative and intraoperative imaging for operative strategies].

    Science.gov (United States)

    Nitschke, P; Bork, U; Plodeck, V; Podlesek, D; Sobottka, S B; Schackert, G; Weitz, J; Kirsch, M

    2016-03-01

    Recent advances in preoperative and postoperative imaging have an increasing influence on surgical decision-making and make more complex surgical interventions possible. This improves the possibilities for frequently occurring challenges and promoting improved functional and oncological outcome. This manuscript reviews the role of preoperative and intraoperative imaging in surgery. Various techniques are explained based on examples from hepatobiliary surgery and neurosurgery, in particular real-time procedures, such as the online use of augmented reality and in vivo fluorescence, as well as new and promising optical techniques including imaging of intrinsic signals and vibrational spectroscopy.

  17. A new strain based brick element for plate bending

    Directory of Open Access Journals (Sweden)

    L. Belounar

    2014-03-01

    Full Text Available This paper presents the development of a new three-dimensional brick finite element by the use of the strain based approach for the linear analysis of plate bending. The developed element has the three essential external degrees of freedom (U, V and W at each of the eight corner nodes as well as at the centroidal node. The displacement field of the developed element is based on assumed functions for the various strains satisfying the compatibility equations and the static condensation technique is used for the internal node. The performance of this element is evaluated on several problems related to thick and thin plate bending in linear analysis. The obtained results show the good performances and accuracy of the present element.

  18. Flow resistance in a compound gravel-bed bend

    Indian Academy of Sciences (India)

    Hossein Afzalimehr; Manouchehr Heidarpour; Alireza Salimi

    2006-12-01

    In this paper, the effect of a gravel-bed in a compound bend (similar to sinusoidal top view) of a natural river (Zayandehrud River flowing through Isfahan, Iran) has been investigated for flow resistance analysis, measuring the velocity with a micro current meter. The data were analysed and the following observations were made. In a compound bend, the law of the wall can be valid for up to 66% of the flow depth from the bed. The parabolic law is the most effective method for the determination of shear velocity. Based on the existing criteria for verifying the equilibrium boundary layer, the flow cannot be in equilibrium. The shear stress distribution and the sediment transport parameters have considerable influence on resistance to flow. Froude number and the flow depth relative to the representative gravel size have little effect on the flow resistance estimation.

  19. An analytic solution to asymmetrical bending problem of diaphragm coupling

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Because rigidity of either hub or rim of diaphragm coupling is much greater than that of the disk, and asymmetrical bending is under the condition of high speed revolution, an assumption is made that each circle in the middle plane before deforma-tion keeps its radius unchanged after deformation, but the plane on which the circle lies has a varying deflecting angle. Based on this assumption, and according to the principle of energy variation, the corresponding Euler's equation can be obtained, which has the primary integral. By neglecting some subsidiary factors, an analytic solution is obtained. Applying these formulas to a hyperbolic model of diaphragm, the results show that the octahedral shear stress varies less along either radial or thickness direction, but fluctu-ates greatly and periodically along circumferential direction. Thus asymmetrical bending significantly affects the material's fatigue.

  20. Transfer matrices of dipoles with bending radius variation

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    With the increasing demand of high brightness in light source, the uniform dipole can not meet the needs of low emittance, and thus the dipole with bending radius variation is introduced in this paper. The transfer matrix of a non-uniform dipole whose bending radius is linearly changed is chosen as an example and a very simple calculation formula of non-uniform dipole transfer matrices is given. The transfer matrices of some common profile non-uniform dipoles are also listed. The comparison of these transfer matrices and the matrices calculated with slices method verifies the numerical accuracy of this formula. This method can make the non-uniform beam dynamic problem simpler, very helpful for emittance research and lattice design with non-uniform dipoles.

  1. A Low Frequency FBG Accelerometer with Symmetrical Bended Spring Plates

    Directory of Open Access Journals (Sweden)

    Fufei Liu

    2017-01-01

    Full Text Available To meet the requirements for low-frequency vibration monitoring, a new type of FBG (fiber Bragg grating accelerometer with a bended spring plate is proposed. Two symmetrical bended spring plates are used as elastic elements, which drive the FBG to produce axial strains equal in magnitude but opposite in direction when exciting vibrations exist, leading to doubling the wavelength shift of the FBG. The mechanics model and a numerical method are presented in this paper, with which the influence of the structural parameters on the sensitivity and the eigenfrequency are discussed. The test results show that the sensitivity of the accelerometer is more than 1000 pm/g when the frequency is within the 0.7–20 Hz range.

  2. Elasticity solutions for functionally graded plates in cylindrical bending

    Institute of Scientific and Technical Information of China (English)

    YANG Bo; DING Hao-jiang; CHEN Wei-qiu

    2008-01-01

    The plate theory of functionally graded materials suggested by Mian and Spencer is extended to analyze the cylindrical bending problem of a functionally graded rectangular plate subject to uniform load. The expansion formula for displacements is adopted. While keeping the assumption that the material parameters can vary along the thickness direction in an arbitrary fashion, this paper considers orthotropic materials rather than isotropic materials. In addition, the traction-free condition on the top surface is replaced with the condition of uniform load applied on the top surface. The plate theory for the particular case of cylindrical bending is presented by considering an infinite extent in the y-direction. Effects of boundary conditions and material inhomogeneity on the static response of functionally graded plates are investigated through a numerical example.

  3. Bending and buckling behavior analysis of foamed metal circular plate.

    Science.gov (United States)

    Fan, Jian Ling; Ma, Lian Sheng; Zhang, Lu; De Su, Hou

    2016-07-04

    This paper establishes a density gradient model along the thickness direction of a circular plate made of foamed material. Based on the first shear deformation plate theory, the result is deduced that the foamed metal circular plate with graded density along thickness direction yields axisymmetric bending problem under the action of uniformly distributed load, and the analytical solution is obtained by solving the governing equation directly. The analyses on two constraint conditions of edge radial clamping and simply supported show that the density gradient index and external load may affect the axisymmetric bending behavior of the plate. Then, based on the classical plate theory, the paper analyzes the behavior of axisymmetric buckling under radial pressure applied on the circular plate. Shooting method is used to obtain the critical load, and the effects of gradient nature of material properties and boundary conditions on the critical load of the plate are analyzed.

  4. The bending of cell sheets - from folding to rolling

    Directory of Open Access Journals (Sweden)

    Keller Ray

    2011-12-01

    Full Text Available Abstract The bending of cell sheets plays a major role in multicellular embryonic morphogenesis. Recent advances are leading to a deeper understanding of how the biophysical properties and the force-producing behaviors of cells are regulated, and how these forces are integrated across cell sheets during bending. We review work that shows that the dynamic balance of apical versus basolateral cortical tension controls specific aspects of invagination of epithelial sheets, and recent evidence that tissue expansion by growth contributes to neural retinal invagination in a stem cell-derived, self-organizing system. Of special interest is the detailed analysis of the type B inversion in Volvox reported in BMC Biology by Höhn and Hallmann, as this is a system that promises to be particularly instructive in understanding morphogenesis of any monolayered spheroid system. See research article: http://www.biomedcentral.com/1741-7007/9/89

  5. Bending characteristic of a cantilevered magnetostrictive film-substrate system

    Institute of Scientific and Technical Information of China (English)

    B.; Narsu

    2007-01-01

    The bending problem of a film-substrate cantilever with arbitrary film-to-substrate thickness ratio is solved exactly by employing the force equilibrium equation, and then the optimization and application of the bending characteristic of the magne-tostrictive cantilever is discussed. Furthermore, the influence of geometrical and physical parameters of the two cantilever components on the maximum free-end deflection of the cantilever is addressed. The results indicate that as the substrate thickness is kept constant, the greater film-to-substrate stiffness ratio will induce a larger deflection, while for the case of fixed total cantilever thickness, the optimal cantilever deflection is independent of the physical parameters of the materials such as Young’s modulus and Poisson’s ratio.

  6. Bending characteristic of a cantilevered magnetostrictive film-substrate system

    Institute of Scientific and Technical Information of China (English)

    B. Narsu; YUN GuoHong

    2007-01-01

    The bending problem of a film-substrate cantilever with arbitrary film-to-substrate thickness ratio is solved exactly by employing the force equilibrium equation, and then the optimization and application of the bending characteristic of the magnetostrictive cantilever is discussed. Furthermore, the influence of geometrical and physical parameters of the two cantilever components on the maximum free-end deflection of the cantilever is addressed. The results indicate that as the substrate thickness is kept constant, the greater film-to-substrate stiffness ratio will induce a larger deflection, while for the case of fixed total cantilever thickness, the optimal cantilever deflection is independent of the physical parameters of the materials such as Young's modulus and Poisson's ratio.

  7. Elastoswellability: Will it bend or will it buckle?

    Science.gov (United States)

    Holmes, Douglas; Pandey, Anupam

    2013-03-01

    Soft mechanical structures such as biological tissues and gels exhibit motion, instabilities, and large morphological changes when subjected to external stimuli. Swelling is a robust approach for inducing structural change as it occurs naturally in humid environments and can be easily adapted for industrial design. Small volumes of fluid that interact favorably with a material can cause large, dramatic, and geometrically nonlinear deformations including beam bending, plate buckling, and surface wrinkling. In this talk we address an overarching question regarding swelling-induced deformations: will the structural change occur globally, or will it be confined to the material's surface? We introduce a materials and geometry defined transition point that describes a fluid-structure's characteristic ``elastoswellability'' lengthscale. By locally swelling unconstrained slender beams and plates with solvents of varying solubility, we identify a transition between local surface wrinkling and global structural bending.

  8. Bending and rotational behaviour of semi-continuous composite beams

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Stresses and deflections were measured in various semi-continuous composite beams.The bending and rotational capacities of the composite connections were measured in terms of beam curvatures and deflections by using two full-scale semi-rigid composite frames with monotonic loadings.The effect of semi-rigid connections on the performance of composite beams with various loadings was compared with predictions and codes.The tests show that the semi-continuous composite beams are more economic and effective than the simple or continuous composite beams.The semi-rigid connections affect the bending capacities and beam deflections,so the connection behavior should be considered in the design of composite beams.Yielding analysis of the steel beam bottom flange has some influence on the deflection calculation of composite beams.

  9. A Topological Approach to Bend-Twist Maps with Applications

    Directory of Open Access Journals (Sweden)

    Anna Pascoletti

    2011-01-01

    Full Text Available In this paper we reconsider, in a purely topological framework, the concept of bend-twist map previously studied in the analytic setting by Tongren Ding in (2007. We obtain some results about the existence and multiplicity of fixed points which are related to the classical Poincaré-Birkhoff twist theorem for area-preserving maps of the annulus; however, in our approach, like in Ding (2007, we do not require measure-preserving conditions. This makes our theorems in principle applicable to nonconservative planar systems. Some of our results are also stable for small perturbations. Possible applications of the fixed point theorems for topological bend-twist maps are outlined in the last section.

  10. Influence of bending test configuration on cracking behavior of FRC

    DEFF Research Database (Denmark)

    Finazzi, Silvia; Paegle, Ieva; Fischer, Gregor;

    2014-01-01

    This paper describes an investigation of the influence of the testing configuration for Fiber Reinforced Concrete in bending and aims at evaluating the influence of the test configuration details on the characterization of the material. Two different types of FRC, Steel Fiber Reinforced Concrete...... (SFRC) and Engineered Cementitious Composites (ECC), were tested and are described in this study. The materials were chosen so that one of them would be strain hardening (ECC) and the other tension softening (SFRC). Notched and un-notched three- and four-point bending tests were carried out to determine...... the flexural load-deformation response of FRC. This research focuses particularly on the influence of the appearance and depth of the notch on the cracking behavior of FRC. For this purpose, several specimens, both un-notched and notched with different depths of the notch (25 mm and 45 mm), were tested...

  11. Negative bending mode curvature via Robin boundary conditions

    Science.gov (United States)

    Adams, Samuel D. M.; Craster, Richard V.; Guenneau, Sébastien

    2009-06-01

    We examine the band spectrum, and associated Floquet-Bloch eigensolutions, arising in straight walled acoustic waveguides that have periodic structure along the guide. Homogeneous impedance (Robin) conditions are imposed along the guide walls and we find that in certain circumstances, negative curvature of the lowest (bending) mode can be achieved. This is unexpected, and has not been observed in a variety of physical situations examined by other authors. Further unexpected properties include the existence of the bending mode only on a subset of the Brillouin zone, as well as permitting otherwise unobtainable velocities of energy transmission. We conclude with a discussion of how such boundary conditions might be physically reproduced using effective conditions and homogenization theory, although the methodology to achieve these effective conditions is an open problem. To cite this article: S.D.M. Adams et al., C. R. Physique 10 (2009).

  12. A Low Frequency FBG Accelerometer with Symmetrical Bended Spring Plates

    Science.gov (United States)

    Liu, Fufei; Dai, Yutang; Karanja, Joseph Muna; Yang, Minghong

    2017-01-01

    To meet the requirements for low-frequency vibration monitoring, a new type of FBG (fiber Bragg grating) accelerometer with a bended spring plate is proposed. Two symmetrical bended spring plates are used as elastic elements, which drive the FBG to produce axial strains equal in magnitude but opposite in direction when exciting vibrations exist, leading to doubling the wavelength shift of the FBG. The mechanics model and a numerical method are presented in this paper, with which the influence of the structural parameters on the sensitivity and the eigenfrequency are discussed. The test results show that the sensitivity of the accelerometer is more than 1000 pm/g when the frequency is within the 0.7–20 Hz range. PMID:28117740

  13. Bending properties of different REBCO coated conductor tapes and Roebel cables at T = 77 K

    Science.gov (United States)

    Otten, Simon; Kario, Anna; Kling, Andrea; Goldacker, Wilfried

    2016-12-01

    Application of REBCO coated conductors in coils or cables involves deformation of the conductor in different modes, such as in-plane bending, out-of-plane bending and torsion. For example, the dipole magnet designs in the EuCARD-2 project require bending radii as low as 7.5 mm, inducing significant bending strain in the REBCO layer. In this paper, we investigate the effect of out-of-plane bending on the current-carrying properties of coated conductors from different manufacturers. The samples are manipulated by means of a Goldacker-type bending rig, which allows continuous bending at T = 77 K. By reversal to R=∞ after each bending step, the reversible strain effect is separated from irreversible degradation. All tested conductors are found to tolerate compressive bending to a radius of 6 mm with less than 5% irreversible degradation of the critical current. The magnitude of the reversible strain effect shows a large variation among the samples. The effect of out-of-plane bending on Roebel cables is investigated as well, and the results are compared to the bending characteristic of single conductors. The results show no detrimental effect of the cable assembly on the bending properties within the constraints of the test.

  14. Advanced System Identification for High-rise Building Using Shear-Bending Model

    Directory of Open Access Journals (Sweden)

    Kohei Fujita

    2016-11-01

    Full Text Available In order to identify physical model parameters of a high-rise building, a new story stiffness identification method is presented based on a shear-bending model and the identification function. Although a shear building model may be the simplest conventional model for representing tall buildings, the system identification (SI method using that model is not necessarily appropriate. This is because the influence of bending deformation is predominant in such high-rise buildings. For this reason, a shear-bending model is used where the shear and bending stiffnesses are unknown. In the previous researches using the shear-bending model, it was difficult to identify the bending stiffnesses stably and reliably. In this paper, to overcome such instability of bending stiffness identification of the shear-bending model, a new SI algorithm using both the shear model and the shear-bending model is presented. The proposed SI algorithm is based on the observation that the fundamental-mode shape of the identified shear model is similar to that of the shear-bending model identified in the previous SI method. In order to verify the advanced SI method, two different 20-story building models are investigated in the numerical simulations. From the results of the simulations, both the shear and bending stiffnesses of the shear-bending model are identified reliably and stably in the proposed SI method.

  15. Rotating Square-Ended U-Bend Using Low-Reynolds-Number Models

    Directory of Open Access Journals (Sweden)

    Konstantinos-Stephen P. Nikas

    2005-01-01

    bend is better reproduced by the low-Re models. Turbulence levels within the rotating U-bend are underpredicted, but DSM models produce a more realistic distribution. Along the leading side, all models overpredict heat transfer levels just after the bend. Along the trailing side, the heat transfer predictions of the low-Re DSM with the NYap, are close to the measurements.

  16. Requirements for Bend Insensitive Fiber in Millimeter-Wave Fronthaul Systems

    DEFF Research Database (Denmark)

    Rommel, Simon; Cavalcante, Lucas Costa Pereira; Vegas Olmos, Juan José;

    2015-01-01

    The impact of fiber bending on mm-wave radioover-fiber transmission is investigated and the need for bend insensitive fiber for front-haul installation confirmed. A 70m Wband hybrid photonic-wireless link including bend insensitive fiber is demonstrated with BER

  17. A new set of bending Td symmetry coordinates for MX4 molecules.

    Science.gov (United States)

    Schmidling, David

    2013-12-15

    The conventional set of Td symmetry coordinates for the bending modes of MX4 molecules can lead to ambiguous geometries when displacements from equilibrium are large. It is proposed here to use internal coordinates that are haversines of the bending angles divided by their sum. The A1 representation becomes a constant, enabling recovery of the bending angles unambiguously, analytically, and without approximation.

  18. Topology design and fabrication of an efficient double 90° photonic crystal waveguide bend

    DEFF Research Database (Denmark)

    Jensen, Jakob Søndergaard; Sigmund, Ole; Frandsen, Lars Hagedorn

    2005-01-01

    We have designed and fabricated a novel 90 bend in a photonic crystal waveguide. The design was obtained using topology optimization and the fabricated waveguide displays a bend loss for transverse-electric-polarized light of less than 1 dB per bend in a 200-nm wavelength range....

  19. Wooden models of an AA quadrupole between bending magnets

    CERN Multimedia

    1978-01-01

    At two points in the AA lattice, a quadrupole (QDN, defocusing, narrow) was tightly wedged between two bending magnets (BST, short, wide). This picture of wooden models lets one imagine the strong interaction between their magnetic fields. There was no way one could calculate with the necessary accuracy the magnetic effects and their consequences for the machine optics. The necessary corrections were made after measurements with a circulating beam, in a tedious iterative procedure, with corrrection coils and shims.

  20. Designing CNC Knit for Hybrid Membrane And Bending Active Structures

    DEFF Research Database (Denmark)

    Tamke, Martin; Holden Deleuran, Anders; Gengnagel, Christoph

    2015-01-01

    Recent advances in computation allow for the integration of design and simulation of highly interrelated systems, such as hybrids of structural membranes and bending active elements. The engaged complexities of forces and logistics can be mediated through the development of materials with project...... means to design, specify, make and test CNC knit as material for hybrid structures in architectural scale. This paper shares the developed process, identifies challenges, potentials and future work...

  1. Influence of Whipping on Long term Vertical Bending Moment

    DEFF Research Database (Denmark)

    Baarholm, G. S.; Jensen, Jørgen Juncher

    2004-01-01

    This paper is concerned with estimating the response value corresponding to a long return period, say a twenty years. Time domain simulation is required to obtain the nonlinear response, and long time series are required to limit the statistical uncertainty in the simulations. It is crucial to in......). Results are presented for the S-175 container ship, (15th & 16th ITTC Seakeeping Committee 1983). The analysis shoes that whipping increases the vertical bending moment and that the correlation is significant...

  2. Bending rigid molecular rods: formation of oligoproline macrocycles.

    Science.gov (United States)

    Scully, Conor C G; Rai, Vishal; Poda, Gennadiy; Zaretsky, Serge; Burns, Darcy C; Houliston, R Scott; Lou, Tiantong; Yudin, Andrei K

    2012-12-01

    Bent but not broken: cyclic oligoprolines are accessed in a reaction that effectively bends rigid oligoproline peptides (see scheme; TBDMS=tert-butyldimethylsilyl). The stitching is accomplished during macrocyclization enabled by aziridine aldehydes and isocyanides. Molecular modeling studies suggest that electrostatic attraction between the termini of the linear peptide is pivotal for macrocyclization. The macrocycles were studied by circular dichroism with a polyproline II structure being observed in larger macrocycles.

  3. New triangular and quadrilateral plate-bending finite elements

    Science.gov (United States)

    Narayanaswami, R.

    1974-01-01

    A nonconforming plate-bending finite element of triangular shape and associated quadrilateral elements are developed. The transverse displacement is approximated within the element by a quintic polynomial. The formulation takes into account the effects of transverse shear deformation. Results of the static and dynamic analysis of a square plate, with edges simply supported or clamped, are compared with exact solutions. Good accuracy is obtained in all calculations.

  4. Springback of thick sheet AHSS subject to bending under tension

    OpenAIRE

    Chalal, Hocine; RACZ, Sever-Gabriel; BALAN, Tudor

    2012-01-01

    http://www.sciencedirect.com/science/article/pii/S0020740312000677; International audience; The springback behavior of four advanced high-strength sheet steels (Dual-Phase, TRIP, ferrite-bainite) with thicknesses ranging from 1.2 to 4 mm was investigated by means of the bending-under-tension (BUT) test. The applicability of several guidelines from the literature was investigated experimentally and numerically. The monotonic decrease of springback as back force increased was confirmed for this...

  5. Bending and Focusing with Plasmas and Crystals - Potential and Challenges

    CERN Document Server

    Zimmermann, F

    2013-01-01

    This talk review the potential of plasmas and crystals for focusing and bending high-energy charged particle beams. It covers topics like plasma lenses, plasma wigglers, plasma dipoles, crystal channeling & reflection, radiation in crystals, crystal accelerators, crystalline beams and ultimate limitations. Past, ongoing or required R&D efforts are highlighted. Invited presentation at EuCARD'13 "Visions for the Future of Particle Accelerators," CERN, 11 June 2013.

  6. Bending light on demand by holographic sculpturing its wavefront

    CERN Document Server

    Latychevskaia, Tatiana

    2015-01-01

    A classical light beam propagates along a straight line and does not bend unless in a medium of variable refractive index. It is well known that by modifying the wavefront in a certain manner, the light intensity can be turned into a certain shape. Examples are optical lenses or Fresnel Zone Plates for focusing an incident wave to a point at the focal plane. Another example are Airy beams created by modifying the phase distribution of the wavefront into an Airy function resulting in a bending of the light intensity while propagating. A further example is holography, where the phase of the wavefront passing through a hologram is changed to mimic the object wavefront, thus providing the illusion that the original object is present in space. However, all these known techniques allow for limited light modifications: either focusing within a limited region in space2 or shaping a certain class of parametric curves along the optical axis or creating a bend in a quadratic-dependent declination as in the case of Airy ...

  7. Bending rigidity of type I collagen homotrimer fibrils

    Science.gov (United States)

    Han, Sejin; Leikin, Sergey; Losert, Wolfgang

    2009-03-01

    Normal type I collagen is an α1(I)2α2(I) heterotrimeric triple helix, but α1(I)3 homotrimers are also found in fetal tissues and various pathological conditions, e.g., causing bone fragility and reducing tendon tensile strength. It remains unclear whether homotrimers alter mechanical properties of individual fibrils or affect tissues by altering their organization at a higher level. To address this question, we investigated how homotrimers affect fibril bending rigidity. Homotrimer fibrils have been shown to be more loosely packed so that we expected them to be more susceptible to bending. However, homotrimer fibrils were more rigid despite being thinner and more hydrated. To quantify fibril rigidity, we analyzed their shape by Fourier decomposition, determined the correlation function for the direction along each fibril, and calculated the distribution of local fibril curvature. The estimated persistence length of homotrimer fibrils was 3 ˜ 10 times longer than for heterotrimer fibrils, indicating much higher bending rigidity of homotrimer fibrils.

  8. Brightness of synchrotron radiation from undulators and bending magnets

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2014-07-15

    We consider the maximum of the Wigner distribution (WD) of synchrotron radiation (SR) fields as a possible definition of SR source brightness. Such figure of merit was originally introduced in the SR community by Kim. The brightness defined in this way is always positive and, in the geometrical optics limit, can be interpreted as maximum density of photon flux in phase space. For undulator and bending magnet radiation from a single electron, the WD function can be explicitly calculated. In the case of an electron beam with a finite emittance the brightness is given by the maximum of the convolution of a single electron WD function and the probability distribution of the electrons in phase space. In the particular case when both electron beam size and electron beam divergence dominate over the diffraction size and the diffraction angle, one can use a geometrical optics approach. However, there are intermediate regimes when only the electron beam size or the electron beam divergence dominate. In this asymptotic cases the geometrical optics approach is still applicable, and the brightness definition used here yields back once more the maximum photon flux density in phase space. In these intermediate regimes we find a significant numerical disagreement between exact calculations and the approximation for undulator brightness currently used in literature. We extend the WD formalism to a satisfactory theory for the brightness of a bending magnet. We find that in the intermediate regimes the usually accepted approximation for bending magnet brightness turns out to be inconsistent even parametrically.

  9. Electro-active material (EAM) based bend sensors

    Science.gov (United States)

    LaComb, Ronald; LaComb, Julie

    2010-04-01

    The capability to accurately estimate strain and orientation of cables in an undersea environment is important for a multitude of applications. One way to estimate the positional location of a submersed cable is to utilize a network of distributed bend sensors providing inputs to a curve fitting algorithm. In this work commercially available bend sensors are characterized for small deflections. In addition proto-type devices are presented which can potentially improve device sensitivity. Commercially available bend sensors are based upon electro-active materials and variable resistance materials. Electro-active materials (EAM) are known for their actuator functionality but certain EAMs are capable of sensing as well. New advances in materials such as Ionic Polymer Metal Composites (IPMC) are proving suitable for quasi-static sensor applications. These sensors are low power, conformal and produce directionally dependent output voltages which are linearly proportional to deflection, with voltage polarity representative of the deflection direction. IPMCs are capable of being morphed for increased sensitivity. Variable resistivity sensors are based on smart epoxy polymer and carbon loaded inks. These sensors are inexpensive and conformal and unlike EAMs provide static measurements.

  10. On-line fuzzy logic control of tube bending

    Science.gov (United States)

    Lieh, Junghsen; Li, Wei Jie

    2005-11-01

    This paper describes the simulation and on-line fuzzy logic control of tube bending. By combining elasticity and plasticity theories, a conventional model was developed. The results from simulation were compared with those obtained from testing. The experimental data reveal that there exists certain level of uncertainty and nonlinearity in tube bending, and its variation could be significant. To overcome this, a on-line fuzzy logic controller with self-tuning capabilities was designed. The advantages of this on-line system are (1) its computational requirement is simple in comparison with more algorithmic-based controllers, and (2) the system does not need prior knowledge of material characteristics. The device includes an AC motor, a servo controller, a forming mechanism, a 3D optical sensor, and a microprocessor. This automated bending machine adopts primary and secondary errors between the actual response and desired output to conduct on-line rule reasoning. Results from testing show that the spring back angle can be effectively compensated by the self- tuning fuzzy system in a real-time fashion.

  11. Bending strength and holding power of tibial locking screws.

    Science.gov (United States)

    Lin, J; Lin, S J; Chiang, H; Hou, S M

    2001-04-01

    The bending strength and holding power of two types of specially designed tibial locking devices, a both-ends-threaded screw and an unthreaded bolt, were studied and compared with four types of commercially available tibial interlocking screws: Synthes, Howmedica, Richards, and Osteo AG. To test bending strength, the devices were inserted into a high molecular weight polyethylene tube and loaded at their midpoint by a materials testing machine to simulate a three point bending test. Single loading yielding strength and cyclic loading fatigue life were measured. To test holding power, the devices were inserted into tubes made of polyurethane foam, and their tips were loaded axially to measure pushout strength. The devices were tested with two different densities of foam materials and two different sizes of pilot holes. Insertion torque and stripping torque of the screws were measured first. Pushout tests were performed with each screw inserted with a tightness equal to 60% of its stripping torque. Test results showed that the yielding strength and the fatigue life were related closely to the inner diameter of the screws. The stripping torque predicted the pushout strength more reliably than did the insertion torque. All tested devices showed greater holding power in the foam with the higher density and with the smaller pilot holes. The both-ends-threaded screw had the highest pushout strength and a satisfactory fatigue strength. The unthreaded bolt had the highest fatigue strength but only fair holding power. Clinical studies of the use of these two types of locking devices are worthwhile.

  12. Ethnic Differences in Bending Stiffness of the Ulna and Tibia

    Science.gov (United States)

    Arnaud, S. B.; Liang, M. T. C.; Bassin, S.; Braun, W.; Dutto, D.; Plesums, K.; Huvnh, H. T.; Cooper, D.; Wong, N.

    2004-01-01

    There is considerable information about the variations in bone mass associated with different opportunity to compare a mechanical property of bone in young college women of Caucasian, Hispanic and Asian descent who gave informed consent to participate in an exercise study. The subjects were sedentary, in good health, eumenorrheic, non-smokers and had body mass indices (BMI) less than 30. Measurements acquired were body weight, kg, and height, cm, calcaneal and wrist bone density, g/square cm (PIXI, Lunar GE) and bending stiffness (EI, Nm(exp 2)) in the ulna and tibia. E1 was determined non-invasively with an instrument called the Mechanical Response Tissue Analyzer (MRTA) that delivers a vibratory stimulus to the center of the ulna or tibia and analyzes the response curve based on the equation E1 = k(sub b) L(exp 3)/48 where k, is lateral bending stiffness, L is the length of the bone, E is Young's modulus of elasticity and I, the bending moment of inertia. The error of the test (CV) based on measurements of an aluminum rod with a known E1 was 4.8%, of calcaneal BMD, 0.54%, and of wrist bone density, 3.45%.

  13. Bending instability in galactic discs. Advocacy of the linear theory

    CERN Document Server

    Rodionov, S A

    2013-01-01

    We demonstrate that in N-body simulations of isolated disc galaxies there is numerical vertical heating which slowly increases the vertical velocity dispersion and the disc thickness. Even for models with over a million particles in a disc, this heating can be significant. Such an effect is just the same as in numerical experiments by Sellwood (2013). We also show that in a stellar disc, outside a boxy/peanut bulge, if it presents, the saturation level of the bending instability is rather close to the value predicted by the linear theory. We pay attention to the fact that the bending instability develops and decays very fast, so it couldn't play any role in secular vertical heating. However the bending instability defines the minimal value of the ratio between the vertical and radial velocity dispersions $\\sigma_z / \\sigma_R \\approx 0.3$ (so indirectly the minimal thickness) which could have stellar discs in real galaxies. We demonstrate that observations confirm last statement.

  14. Performance of a novel VUV bending magnet beamline

    CERN Document Server

    Song, Y F; Hsieh, T F; Huang, L R; Chung, S C; Cheng, N F; Hsiung, G Y; Wang, D J; Chen, C T; Tsang, K L

    2001-01-01

    A novel high resolution, high flux bending magnet beamline with an energy range from 5 to 40 eV has been constructed at SRRC. This Dragon-like beamline, which horizontally collects 50 mrad of synchrotron radiation from a bending magnet source, uses four cylindrical gratings with an included angle of 140 deg. and a movable curved exit slit. The average photon flux with an energy resolving power of 1000 is about 2x10 sup 1 sup 2 photons/s, which is among the highest of all existing VUV bending magnet beamlines. An energy resolving power of 24,000 at 6.8 eV has been obtained from the Schumann-Runge bands (B sup 3 limit construction operator in a limit construction/sum L: summation operator operator End lower limit of a limit construction u lower limit End limit End sup - /leftarrow/gets A: =leftward arrow X sup 3 limit construction operator in a limit construction/sum L: summation operator operator End lower limit of a limit construction g lower limit End limit End sup -) absorption spectra of O sub 2 gas. A pho...

  15. Obstructive parotitis secondary to an acute masseteric bend.

    Science.gov (United States)

    Reddy, Ryan; White, David R; Gillespie, M Boyd

    2012-01-01

    To investigate 3 cases of chronic parotitis secondary to an acute bend in Stensen's duct caused by an enlargement of the masseteric space. Three female patients presented with symptoms consistent with obstructive parotitis including glandular swelling and tenderness during meals. A 10-year-old patient had unilateral facial swelling with enlargement of the masseter muscle and mandible later diagnosed as fibrous dysplasia. Salivary endoscopy showed an acute bend in Stensen's duct secondary to a mass effect. The patient's parotid swelling resolved following debulking of the mandibular mass and sialendoscopy with irrigation. Two adult patients with bilateral parotid involvement presented with bilateral masseteric hypertrophy and dental wear facets consistent with bruxism. Salivary endoscopy revealed bilateral kinking of Stensen's duct with jaw closure. Both patients improved symptomatically following nightly bite guard use and ultrasound-guided Botox injections of the masseter muscle and parotid. Obstructive parotitis is rarely caused by an acute masseteric bend. Diagnosis of a kinking Stensen's duct is aided with salivary endoscopy and imaging to determine the precipitating pathology. In the case of masseteric hypertrophy, symptomatic improvement can be achieved with Botox-induced atrophy of masseteric hypertrophy or with surgical reduction for associated fibrous dysplasia. Copyright © 2011 S. Karger AG, Basel.

  16. Cylindrical Bending of Deformable Textile Rectangular Patch Antennas

    Directory of Open Access Journals (Sweden)

    Freek Boeykens

    2012-01-01

    Full Text Available Textile patch antennas are well known as basic components for wearable systems that allow communication between a human body and the external world. Due to their flexibility, textile antennas are subjected to bending when worn, causing a variation in resonance frequency and radiation pattern with respect to the flat state in which their nominal design is performed. Hence, it is important for textile antenna engineers to be able to predict these performance parameters as a function of the bending radius. Therefore, we propose a comprehensive analytical model that extends the cylindrical cavity model for conformal rigid patch antennas by incorporating the effects of patch stretching and substrate compression. It allows to predict the resonance frequency and the radiation pattern as a function of the bending radius. Its validity has been verified experimentally. Unlike previous contributions, which concerned only qualitative studies by means of measurements and numerical full-wave simulations, the proposed model offers advantages in terms of physical insight, accuracy, speed, and cost.

  17. How two-dimensional bending can extraordinarily stiffen thin sheets

    Science.gov (United States)

    Pini, V.; Ruz, J. J.; Kosaka, P. M.; Malvar, O.; Calleja, M.; Tamayo, J.

    2016-07-01

    Curved thin sheets are ubiquitously found in nature and manmade structures from macro- to nanoscale. Within the framework of classical thin plate theory, the stiffness of thin sheets is independent of its bending state for small deflections. This assumption, however, goes against intuition. Simple experiments with a cantilever sheet made of paper show that the cantilever stiffness largely increases with small amounts of transversal curvature. We here demonstrate by using simple geometric arguments that thin sheets subject to two-dimensional bending necessarily develop internal stresses. The coupling between the internal stresses and the bending moments can increase the stiffness of the plate by several times. We develop a theory that describes the stiffness of curved thin sheets with simple equations in terms of the longitudinal and transversal curvatures. The theory predicts experimental results with a macroscopic cantilever sheet as well as numerical simulations by the finite element method. The results shed new light on plant and insect wing biomechanics and provide an easy route to engineer micro- and nanomechanical structures based on thin materials with extraordinary stiffness tunability.

  18. Bending elasticity of charged surfactant layers: the effect of mixing.

    Science.gov (United States)

    Bergström, L Magnus

    2006-08-01

    Expressions have been derived from which the spontaneous curvature (H(0)), bending rigidity (k(c)), and saddle-splay constant (k(c)) of mixed monolayers and bilayers may be calculated from molecular and solution properties as well as experimentally available quantities such as the macroscopic hydrophobic-hydrophilic interfacial tension. Three different cases of binary surfactant mixtures have been treated in detail: (i) mixtures of an ionic and a nonionic surfactant, (ii) mixtures of two oppositely charged surfactants, and (iii) mixtures of two ionic surfactants with identical headgroups but different tail volumes. It is demonstrated that k(c)H(0), k(c), and k(c) for mixtures of surfactants with flexible tails may be subdivided into one contribution that is due to bending properties of an infinitely thin surface as calculated from the Poisson-Boltzmann mean field theory and one contribution appearing as a result of the surfactant film having a finite thickness with the surface of charge located somewhat outside the hydrophobic-hydrophilic interface. As a matter of fact, the picture becomes completely different as finite layer thickness effects are taken into account, and as a result, the spontaneous curvature is extensively lowered whereas the bending rigidity is raised. Furthermore, an additional contribution to k(c) is present for surfactant mixtures but is absent for k(c)H(0) and k(c). This contribution appears as a consequence of the minimization of the free energy with respect to the composition of a surfactant layer that is open in the thermodynamic sense and must always be negative (i.e., k(c) is generally found to be brought down by the process of mixing two or more surfactants). The magnitude of the reduction of k(c) increases with increasing asymmetry between two surfactants with respect to headgroup charge number and tail volume. As a consequence, the bending rigidity assumes the lowest values for layers formed in mixtures of two oppositely charged

  19. Preoperative prediction model of outcome after cholecystectomy for symptomatic gallstones

    DEFF Research Database (Denmark)

    Borly, L; Anderson, I B; Bardram, L

    1999-01-01

    patients completed all questionnaires. Twenty-one patients continued to have abdominal pain after the operation. Patients with pain 1 year after cholecystectomy were characterized by the preoperative presence of a high dyspepsia score, 'irritating' abdominal pain, and an introverted personality...

  20. [The 'paper-based' preoperative evaluation: sometimes, a suitable alternative].

    NARCIS (Netherlands)

    Bucx, M.J.L.; Wolff, A.P.; Scheffer, G.J.

    2012-01-01

    In the Netherlands, the majority of elective-surgery patients are evaluated by the anaesthesiologist at the preoperative assessment clinic. We believe that this visit can be omitted in selected patients as it has only minimal benefit, whereas its disadvantages can be substantial. Alternatively, the

  1. Accuracy of diagnostic imaging in nephroblastoma before preoperative chemotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Rieden, K. [Radiologische Klinik, Abt. Klinische Radiologie, Heidelberg (Germany); Weirich, A. [Kinderklinik, Univ. of Heidelberg (Germany); Troeger, J. [Radiologische Klinik, Abt. Paediatrische Radiologie, Univ. of Heidelberg (Germany); Gamroth, A.H. [Deutsches Krebsforschungszentrum, Heidelberg (Germany); Raschke, K. [Radiologische Klinik, Abt. Paediatrische Radiologie, Univ. of Heidelberg (Germany); Ludwig, R. [Kinderklinik, Univ. of Heidelberg (Germany)

    1993-04-01

    From July 1988 to February 1991, 130 children with the tentative diagnosis of nephroblastoma were treated preoperatively. The initial diagnostic images (excretory urography, ultrasound, CT, MRI) have been analysed both prospectively and retrospectively and the findings correlated with the intraoperative and histological results. Of the preoperatively treated patients 93.8% had a Wilms` tumour or one of its variants. Five patients had a different malignant tumour and 3 patients, i.e. 2.3% of those preoperatively treated or 1.6% of all registered patients, had benign tumours of the kidney. Wilms` tumour generally presented as a well-defined mass with an inhomogeneous morphology on CT. On ultrasound only 24% of the tumours were homogeneous. Intratumoral haemorrhage and cystic areas occurred frequently; calcifications were rare (8%). With regard to caval involvement only ultrasound and MRI enabled the correct diagnosis, while CT could not differentiate compressions from invasion. The pretherapeutic diagnostic imaging was of sufficient accuracy to start preoperative chemotherapy without diagnostic biopsy. (orig.)

  2. Ranitidine improves postoperative suppression of antibody response to preoperative vaccination

    DEFF Research Database (Denmark)

    Nielsen, Hans Jørgen; Hammer, J H; Moesgaard, F;

    1992-01-01

    The effect of the histamine-2 receptor antagonist ranitidine (100 mg intravenously every 12 hours for 72 hours) on postoperative serum antibody responses to preoperative immunization with six limit of flocculation tetanus toxoid and six limit of flocculation diphtheria toxoid was assessed...

  3. Preoperative subtyping of meningiomas by perfusion MR imaging

    NARCIS (Netherlands)

    Zhang, Hao; Roediger, Lars A.; Shen, Tianzhen; Miao, Jingtao; Oudkerk, Matthijs

    2008-01-01

    Introduction This paper aims to evaluate the value of perfusion magnetic resonance (MR) imaging in the preoperative subtyping of meningiomas by analyzing the relative cerebral blood volume (rCBV) of three benign subtypes and anaplastic meningiomas separately. Materials and methods Thirty-seven menin

  4. Pheochromocytoma : a review on preoperative treatment with phenoxybenzamine or doxazosin

    NARCIS (Netherlands)

    van der Zee, P A; de Boer, A|info:eu-repo/dai/nl/075097346

    2014-01-01

    BACKGROUND: During surgical treatment of pheochromocytoma,`haemodynamic instability may occur. To prevent this, patients receive preoperative treatment with an alpha-blocker. Nowadays, some centres use phenoxybenzamine, while others use doxazosin. The purpose of this review is to analyse the current

  5. Preoperative prediction model of outcome after cholecystectomy for symptomatic gallstones

    DEFF Research Database (Denmark)

    Borly, L; Anderson, I B; Bardram, Linda

    1999-01-01

    BACKGROUND: After cholecystectomy for symptomatic gallstone disease 20%-30% of the patients continue to have abdominal pain. The aim of this study was to investigate whether preoperative variables could predict the symptomatic outcome after cholecystectomy. METHODS: One hundred and two patients w...

  6. Preoperative statin therapy and infectious complications in cardiac surgery

    NARCIS (Netherlands)

    Hartholt, N L; Rettig, T C D; Schijffelen, M; Morshuis, W J; van de Garde, E M W; Noordzij, P G

    AIM: To assess whether preoperative statin therapy is associated with the risk of postoperative infection in patients undergoing cardiac surgery. METHODS: 520 patients undergoing cardiac surgery in 2010 were retrospectively examined. Data regarding statin and antibiotic use prior to and after

  7. Preoperative anxiety and emergence delirium and postoperative maladaptive behaviors.

    Science.gov (United States)

    Kain, Zeev N; Caldwell-Andrews, Alison A; Maranets, Inna; McClain, Brenda; Gaal, Dorothy; Mayes, Linda C; Feng, Rui; Zhang, Heping

    2004-12-01

    Based on previous studies, we hypothesized that the clinical phenomena of preoperative anxiety, emergence delirium, and postoperative maladaptive behavioral changes were closely related. We examined this issue using data obtained by our laboratory over the past 6 years. Only children who underwent surgery and general anesthesia using sevoflurane/O(2)/N(2)O and who did not receive midazolam were recruited. Children's anxiety was assessed preoperatively with the modified Yale Preoperative Anxiety Scale (mYPAS), emergence delirium was assessed in the postanesthesia care unit, and behavioral changes were assessed with the Post Hospital Behavior Questionnaire (PHBQ) on postoperative days 1, 2, 3, 7, and 14. Regression analysis showed that the odds of having marked symptoms of emergence delirium increased by 10% for each increment of 10 points in the child's state anxiety score (mYPAS). The odds ratio of having new-onset postoperative maladaptive behavior changes was 1.43 for children with marked emergence status as compared with children with no symptoms of emergence delirium. A 10-point increase in state anxiety scores led to a 12.5% increase in the odds that the child would have a new-onset maladaptive behavioral change after the surgery. This finding is highly significant to practicing clinicians, who can now predict the development of adverse postoperative phenomena, such as emergence delirium and postoperative behavioral changes, based on levels of preoperative anxiety.

  8. Comparison of preoperative anxiety in reconstructive and cosmetic surgery patients.

    Science.gov (United States)

    Sönmez, Ahmet; Bişkin, Nurdan; Bayramiçli, Mehmet; Numanoğlu, Ayhan

    2005-02-01

    Surgery is a serious stressor and a cause of anxiety for the patients. Reconstructive surgery patients are mostly operated on because of certain functional impairment or disability; on the contrary, cosmetic surgery patients do not have any physical impairment and they are operated on because of mostly psychologic reasons. The aim of this study was to compare the anxiety levels in the reconstructive surgery patients and cosmetic surgery patients preoperatively. Thirty-two patients in the reconstructive surgery group and 30 patients in the cosmetic surgery group were included in the study. State Trait Anxiety Inventory was used to measure the anxiety levels in these 2 groups preoperatively. The 2 groups were similar in characteristics such as age, gender distribution, number of previous operations, and trait anxiety scores. Mean state anxiety scores obtained for the reconstructive surgery group was 38.0 +/- 8.7, while it was 44.2 +/- 10.79 for the cosmetic surgery group (t test, degrees of freedom = 60, P = 0.015). This study reveals that preoperative anxiety levels in the cosmetic surgery patients are higher than those of the reconstructive surgery patients. Therefore, adequate preoperative preparation for cosmetic surgery should include attempts to cope with anxiety. Anxiolytics may be used more liberally and professional psychologic assistance may be required.

  9. Preoperative diagnosis of colonic angiolipoma: A case report

    Institute of Scientific and Technical Information of China (English)

    Yang-Yuan Chen; Maw-Soan Soon

    2005-01-01

    Angiolipoma, a common benign tumor mostly seen in the subcutaneous tissue, is a rare pathological condition in the gastrointestinal tract that is usually diagnosed postoperatively. Tn this case report, an angiolipoma was diagnosed preoperatively by imaging (including CT scans,abdominal echo, barium enema, and colonoscopy). This pathology was confirmed postoperatively. Computed tomography scan, abdominal echo, and barium enema images were presented.

  10. Evaluating the effect of preoperative oral gabapentin on ...

    African Journals Online (AJOL)

    2010-05-02

    May 2, 2010 ... 0riginal Research: Preoperative oral gabapentin in patients ... having pain scores ≥ 5 received rescue analgesia in the form of intravenous tramadol 0.5 mg.kg-1. If the ... decreases postoperative pain scores at zero hour and the rescue ... decreased physical and social function, as well as ... 2% lignocaine.

  11. The Amsterdam Preoperative Anxiety and Information Scale (APAIS)

    Science.gov (United States)

    Moerman, N; van Dam, F S; Muller, M J; Oosting, H

    1996-03-01

    The purpose of the present study was to assess patients' anxiety level and information requirement in the preoperative phase. During routine preoperative screening, 320 patients were asked to assess their anxiety and information requirement on a six-item questionnaire, the Amsterdam Preoperative Anxiety and Information Scale (APAIS). Two hundred patients also completed Spielberger's State-Trait Anxiety Inventory (STAI-State). Patients were able to complete the questionnaire in less than 2 min. On factor analysis, two factors emerged clearly: anxiety and the need for information. The anxiety scale correlated highly (0.74) with the STAI-State. It emerged that 32% of the patients could be considered as "anxiety cases" and over 80% of patients have a positive attitude toward receiving information. Moreover, results demonstrated that 1) women were more anxious that men; 2) patients with a high information requirement also had a high level of anxiety; 3) patients who had never undergone an operation had a higher information requirement than those who had. The APAIS can provide anesthesiologists with a valid, reliable, and easily applicable instrument for assessing the level of patients' preoperative anxiety and the need for information.

  12. A psychological preoperative program: effects on anxiety and cooperative behaviors.

    Science.gov (United States)

    Cuzzocrea, Francesca; Gugliandolo, Maria C; Larcan, Rosalba; Romeo, Carmelo; Turiaco, Nunzio; Dominici, Tiziana

    2013-02-01

    To evaluate the effectiveness of a psychological preoperative program in reducing preoperative anxiety and in promoting compliance of pediatric participants with surgical procedures. Fifty children and their mothers were subjected to two conditions of treatment to investigate whether psychological preparation activities and psychologist's support during all phases of the operatory iter (group 1) were as efficient in reducing mothers' and child's anxiety and in increasing the child's compliance as distraction activities (group 2). The observed child anxiety was assessed using mYPAS; compliant behaviors with Induction Compliance Checklist; and mothers' anxiety with Amsterdam Pre-operative Anxiety and Information Scale. Children of the first group were less anxious and more cooperative in the preoperative period and during anesthesia induction than in the other condition. The psychological program was also more efficient in reducing mothers' anxiety. Finally, the mothers of group 1 showed a significantly higher satisfaction and judged as significantly more effective the program proposed to prepare their children than the mothers of group 2. Preparing children through playful dramatization of the operative procedure, manipulation of medical instruments and psychologist's support may be useful in pediatric surgery structures. © 2013 Blackwell Publishing Ltd.

  13. Effect of routine preoperative fasting on residual gastric volume and ...

    African Journals Online (AJOL)

    2016-02-10

    Feb 10, 2016 ... Nigerian Journal of Clinical Practice • Nov‑Dec 2016 • Vol 19 • Issue 6 induction of ... disorder, receiving antacids, or H2 receptor blockers, or those who ... The patients' preoperative anxiety states were graded using the ...

  14. Usefulness of preoperative MRI in recurrent anorectal fistula

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hwa Jin; Cho, Jae Ho; Kim, Jae Woon; Park, Bok Hwan; Hwang, Mi Soo; Sim, Min Chul; Byun, Woo Mok [Yeungnam Univ. School of Medicine, Daegu (Korea, Republic of)

    1997-04-01

    To evaluate the usefulness of preoperative MRI in the patient with recurrent anorectal fistula. Fourteen patients with recurrent anorectal fistula underwent non-contrast MRI. In eight patients, T1-, T2- and proton-weighted images were taken in the axial, coronal and sagittal planes, and T1- and T2-weighted images taken in the axial and coronal planes were obtained from the other six. Fourteen cases of anorectal fistula and eight cases in which there was a combined abscess were detected. Preoperative MRI clearly showed the exact anatomical relationship with the anal sphincter, levator ani and surrounding soft tissue. In two cases in which there was fibrous scarring of the fistula tract, low signal intensities were seen on all MRI sequences. Preoperative information in the group in which only axial and coronal T1- and T2-weighted images were obtained was sufficient. Preoperative MRI in patients with recurrent anorectal fistula or suspected multiple fistulous tracts provide objective information concerning the anatomical location and extension of a fistula and combined abscess and could thus reduce the reoperation rate. An understanding of pathologic state through MRI signal intensity can help decide the most appropriate course of treatment.

  15. Improving formability of tube bending for a copper material using finite element simulation

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Duc Toan; Nnuyen, Dinh Thanh [Hungyen University of Technology and Education, Hungyen (Viet Nam); Kim, Young Suk [Kyungpook National University, Daegu (Korea, Republic of)

    2015-10-15

    Bending tubes are key products in many industries. The geometric parameters of the bending process are considered according to Taguchi's orthogonal array and then coupled with finite element simulation to predict and improve the formability of the tube bending process for copper JIS25A material. Three parameters, namely, mandrel diameter, distance between mandrel rings, and distance from the tip of the mandrel bar to the center of the base die, are selected to study their effects on the quality of the bending process. The variance analysis shows that the effect distribution of each parameter to bending quality is determined, and optimal conditions are adopted to conduct experiments.

  16. Control of Prestressing Force in Rod for Reducing Bending in Beams

    Science.gov (United States)

    Wong, M. B.

    2010-05-01

    This paper presents a method to determine the prestressing force required in a rod for reducing the bending effects in a beam. The rod is positioned underneath the beam such that the prestressing force is counteracting the effects of beam bending. It has been found that the prestressing force may also increase the bending as a result of P-δ effect. Therefore, the choice of both the prestressing force and the rod eccentricity from the beam axis is important in determining the appropriate actions to resist the bending of the beam. Over-prestressing the rod may even induce bending or buckling failure in the beam in the reverse direction.

  17. EXPERIMENTAL STUDY ON BED SCOUR IN A 90°CHANNEL BEND

    Institute of Scientific and Technical Information of China (English)

    Masoud GHODSIAN; S. Kamal MOUSAVI

    2006-01-01

    The special feature of bend flow leads to scouring of the bed and bank. Various parameters like flow depth, flow velocity or discharge, geometry of bend and characteristics of bed material may affect the scour process. Experiments were carried out to study the effect of some important parameters on bend scour under clear water condition. Experiments were conducted in a 0.6m wide and 0.7m high flume with 90 degree bend. The lateral variations of bed slope were studied. The maximum depth of scour was correlated to densimetric Froude number, relative bend radius and relative depth of flow.

  18. In situ transmission electron microscopy of individual carbon nanotetrahedron/ribbon structures in bending

    Energy Technology Data Exchange (ETDEWEB)

    Kohno, Hideo, E-mail: kohno.hideo@kochi-tech.ac.jp [School of Environmental Science and Engineering, Kochi University of Technology, Kami, Kochi 782-8502 (Japan); Masuda, Yusuke [Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

    2015-05-11

    When the direction of flattening of a carbon nanotube changes during growth mediated by a metal nanoparticle, a carbon nanotetrahedron is formed in the middle of the carbon nanoribbon. We report the bending properties of the carbon nanotetrahedron/nanoribbon structure using a micro-manipulator system in a transmission electron microscope. In many cases, bending occurs at an edge of the carbon nanotetrahedron. No significant change is observed in the tetrahedron's shape during bending, and the bending is reversible and repeatable. Our results show that the carbon nanotetrahedron/nanoribbon structure has good durability against mechanical bending.

  19. Probabilistic Assessment of Degree of Bending in Tubular X-Joints of Offshore Structures Subjected to Bending Loads

    Directory of Open Access Journals (Sweden)

    Hamid Ahmadi

    2015-01-01

    Full Text Available Fatigue life of tubular joints in offshore structures is significantly influenced by the degree of bending (DoB. The DoB exhibits considerable scatter calling for greater emphasis in accurate determination of its governing probability distribution which is a key input for the fatigue reliability analysis of a tubular joint. Although the tubular X-joints are commonly found in offshore jacket structures, as far as the authors are aware, no comprehensive research has been carried out on the probability distribution of the DoB in tubular X-joints. In the present paper, results of parametric equations available for the calculation of the DoB have been used to develop probability distribution models for the DoB in the chord member of tubular X-joints subjected to four types of bending loads. Based on a parametric study, a set of samples was prepared and density histograms were generated for these samples using Freedman-Diaconis method. Twelve different probability density functions (PDFs were fitted to these histograms. In each case, Kolmogorov-Smirnov test was used to evaluate the goodness of fit. Finally, after substituting the values of estimated parameters for each distribution, a set of fully defined PDFs have been proposed for the DoB in tubular X-joints subjected to bending loads.

  20. [Evaluation of preoperative anxiety in patients requiring glaucoma filtration surgery].

    Science.gov (United States)

    Lemaitre, S; Blumen-Ohana, E; Akesbi, J; Laplace, O; Nordmann, J-P

    2014-01-01

    Preoperative anxiety is often expressed by patients requiring filtration surgery for their glaucoma. So far, there has been no scale for screening this group of patients for preoperative anxiety. The Amsterdam Preoperative Anxiety and Information Scale (APAIS) is a self-evaluation questionnaire which has been used in specialties other than ophthalmology and which makes it possible to identify the adult patients with a high level of preoperative anxiety over an upcoming surgical procedure. The purpose of this study is to estimate the preoperative anxiety in glaucoma patients requiring filtration surgery. We performed a prospective study of 36 adult patients with chronic glaucoma not responding to medical treatment and who were about to undergo filtration surgery (trabeculectomy or deep sclerectomy). The APAIS questionnaire was given to the patients after discussing the indication for surgery. A global anxiety score (ranging from 4 to 20) above 10 defined patients with a high level of preoperative anxiety. We attempted to identify among these patients the factors related to filtration surgery which caused them anxiety (lack of control of intraocular pressure, risk of blindness, presence of the filtering bleb). In our sample of patients, we found that glaucoma was a source of anxiety. That was also true for the surgical procedure, though most patients believe that once the decision had been made, their psychological status was not modified by the upcoming procedure. The patient-clinician relationship is important in any chronic disease, all the more so in glaucoma, since this disease remains asymptomatic for a long time. When filtration surgery is necessary, the patients are going to express less preoperative anxiety if they trust their physician and if individualized information has been given to them The French version of the APAIS is a quick scale, easily completed, that can be recommended for evaluating anxiety and patients' need for information prior to filtering

  1. Preoperative anemia in colon cancer: assessment of risk factors.

    Science.gov (United States)

    Dunne, James R; Gannon, Christopher J; Osborn, Tiffany M; Taylor, Michelle D; Malone, Debra L; Napolitano, Lena M

    2002-06-01

    Anemia is common in cancer patients and is associated with reduced survival. Recent studies document that treatment of anemia with blood transfusion in cancer patients is associated with increased infection risk, tumor recurrence, and mortality. We therefore investigated the incidence of preoperative anemia in colorectal cancer and assessed risk factors for anemia. Prospective data were collected on 311 patients diagnosed with colorectal cancer over a 6-year period from 1994 through 1999. Patients were stratified by age, gender, presenting complaint, preoperative hematocrit, American Joint Committee on Cancer (AJCC) stage, and TNM classification. Discrete variables were compared using Pearson's Chi-square analysis. Continuous variables were compared using Student's t test. Differences were considered significant when P colon cancer with an incidence of 57.6 per cent followed by left colon cancer (42.2%) and rectal cancer (29.8%). Patients with right colon cancer had significantly lower preoperative hematocrits compared with left colon cancer (33 +/- 8.5 vs 36 +/- 7.4; P rectal cancer (33 +/- 8.5 vs 38 +/- 6.0; P colon cancer also had significantly increased stage at presentation compared with left colon cancer (2.3 +/- 1.3 vs 2.1 +/- 1.2; P cancer. We conclude that there is a high incidence of anemia in patients with colon cancer. Patients with right colon cancer had significantly lower preoperative hematocrits and higher stage of cancer at diagnosis. Complete colon evaluation with colonoscopy is warranted in patients with anemia to improve earlier diagnosis of right colon cancer. A clinical trial of preoperative treatment of anemic colorectal cancer patients with recombinant human erythropoietin is warranted.

  2. Preoperative anxiety in surgical patients - experience of a single unit.

    Science.gov (United States)

    Matthias, Anne Thushara; Samarasekera, Dharmanbandhu Nandadeva

    2012-03-01

    Preoperative anxiety has a significant effect on the outcome of anesthesia and surgery. At present, there is no published data on the preoperative anxiety levels in Sri Lankan patients. In the West, several validated questionnaires such as The Amsterdam Preoperative Anxiety and Information Scale (APAIS) and State Trait Anxiety Inventory (STAI) are used. To measure the preoperative anxiety levels in patients using APAIS and to analyze the factors affecting anxiety and the role played by the anesthetist in allaying anxiety. One hundred patients scheduled for elective surgery were prospectively studied using the APAIS. The internal consistency was checked using Cronbach's alpha. The ages varied 25 to 72 years (mean=48.7 years, SD=13.6). Reliability of the APAIS was high; Cronbach's alpha=0.864 in the overall component and 0.84, 0.73 and 0.97 in the anxiety related to surgery, anesthesia and in the information desire components, respectively. Females were more anxious than males (p=0.02) and those who had never sustained surgery were more anxious than those who previously had surgery (p=0.05). An anesthetist's visit and premedication reduced total anxiety scores (Z=-3.07, p=0.002) and anesthesia related anxiety scores (Z=-3.45, p=0.001). The prevalence of anxiety is high among Sri Lankan patients. Females are more anxious than males and those who have never had surgery are more anxious than those who have had surgery. The anesthetist's visit could reduce anxiety. Sinhala version of the APAIS is highly reliable in assessing the preoperative anxiety levels. Copyright © 2012. Published by Elsevier B.V.

  3. Optimal r/b ratio of bend channel in centrifugal compressor

    Institute of Scientific and Technical Information of China (English)

    Suping WEN; Xiaowen HU; Yong ZHANG; Jun WANG; Tingbin LI

    2008-01-01

    A numerical investigation on the flow in a bend channel by coupling the impeller with the vaneless diffuser in a centrifugal compressor with different r/b ratios (bend radius r to bend channel width b) is presented. The jet-wake effect of the impeller outlet is considered and flow pattern in the bend channel and the performance of the centrifugal compressor stage are investigated. The results indicate that there is an optimal r/b ratio for increasing the stage efficiency to the highest for a specific compressor stage. The change in r/b ratio significantly affects the flow angle of the bend chan-nel outlet. The prime reason for the total pressure loss in the bend channel is the wall friction in the bend channel.

  4. Influence of Characteristics on Bending Strength of Layered Steel Fiber Reinforced Concrete

    Institute of Scientific and Technical Information of China (English)

    DAI Shao-bin; SONG Ming-hai; HUANG Jun

    2005-01-01

    The influence of two main characteristics of steel fiber, the aspect ratio (Df) and volume fraction (pf), on the bending strength of Layered Steel Fiber Reinforced Concrete (LSFRC) is investigated by using orthogonal test. Via the variance analysis on the experimental results and trend analysis on the two characteristics, Df is found significantly related to the bending strength of LSFRC. The influence ratio is 63.3%. The bending strength of LSFRC increases if Df increases, makes better when Df reaches 100. ρf has ordinary influence on the bending strength of LSFRC. The influence ratio is 29.2%. Other characteristics, such as the shape of steel fiber and the mix proportion, have less influence. The best ρf contributing to the bending strength of LSFRC is 1.5 %. If pf is greater than 1.5 %, it has negative influence on the bending strength of LSFRC. So, pf makes a limited contribution to the bending strength of LSFRC.

  5. Brightness of synchrotron radiation from undulators and bending magnets.

    Science.gov (United States)

    Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

    2015-03-01

    The maximum of the Wigner distribution (WD) of synchrotron radiation (SR) fields is considered as a possible definition of SR source brightness. Such a figure of merit was originally introduced in the SR community by Kim [(1986), Nucl. Instrum. Methods Phys. Res. A, 246, 71-76]. The brightness defined in this way is always positive and, in the geometrical optics limit, can be interpreted as the maximum density of photon flux in phase space. For undulator and bending magnet radiation from a single electron, the WD function can be explicitly calculated. In the case of an electron beam with a finite emittance the brightness is given by the maximum of the convolution of a single electron WD function and the probability distribution of the electrons in phase space. In the particular case when both electron beam size and electron beam divergence dominate over the diffraction size and the diffraction angle, one can use a geometrical optics approach. However, there are intermediate regimes when only the electron beam size or the electron beam divergence dominate. In these asymptotic cases the geometrical optics approach is still applicable, and the brightness definition used here yields back once more to the maximum photon flux density in phase space. In these intermediate regimes a significant numerical disagreement is found between exact calculations and the approximation for undulator brightness currently used in the literature. The WD formalism is extended to a satisfactory theory for the brightness of a bending magnet. It is found that in the intermediate regimes the usually accepted approximation for bending magnet brightness turns out to be inconsistent even parametrically.

  6. On the bending algorithms for soft objects in flows

    Science.gov (United States)

    Guckenberger, Achim; Schraml, Marcel P.; Chen, Paul G.; Leonetti, Marc; Gekle, Stephan

    2016-10-01

    One of the most challenging aspects in the accurate simulation of three-dimensional soft objects such as vesicles or biological cells is the computation of membrane bending forces. The origin of this difficulty stems from the need to numerically evaluate a fourth order derivative on the discretized surface geometry. Here we investigate six different algorithms to compute membrane bending forces, including regularly used methods as well as novel ones. All are based on the same physical model (due to Canham and Helfrich) and start from a surface discretization with flat triangles. At the same time, they differ substantially in their numerical approach. We start by comparing the numerically obtained mean curvature, the Laplace-Beltrami operator of the mean curvature and finally the surface force density to analytical results for the discocyte resting shape of a red blood cell. We find that none of the considered algorithms converges to zero error at all nodes and that for some algorithms the error even diverges. There is furthermore a pronounced influence of the mesh structure: Discretizations with more irregular triangles and node connectivity present serious difficulties for most investigated methods. To assess the behavior of the algorithms in a realistic physical application, we investigate the deformation of an initially spherical capsule in a linear shear flow at small Reynolds numbers. To exclude any influence of the flow solver, two conceptually very different solvers are employed: the Lattice-Boltzmann and the Boundary Integral Method. Despite the largely different quality of the bending algorithms when applied to the static red blood cell, we find that in the actual flow situation most algorithms give consistent results for both hydrodynamic solvers. Even so, a short review of earlier works reveals a wide scattering of reported results for, e.g., the Taylor deformation parameter. Besides the presented application to biofluidic systems, the investigated

  7. Geologic map of Big Bend National Park, Texas

    Science.gov (United States)

    Turner, Kenzie J.; Berry, Margaret E.; Page, William R.; Lehman, Thomas M.; Bohannon, Robert G.; Scott, Robert B.; Miggins, Daniel P.; Budahn, James R.; Cooper, Roger W.; Drenth, Benjamin J.; Anderson, Eric D.; Williams, Van S.

    2011-01-01

    The purpose of this map is to provide the National Park Service and the public with an updated digital geologic map of Big Bend National Park (BBNP). The geologic map report of Maxwell and others (1967) provides a fully comprehensive account of the important volcanic, structural, geomorphological, and paleontological features that define BBNP. However, the map is on a geographically distorted planimetric base and lacks topography, which has caused difficulty in conducting GIS-based data analyses and georeferencing the many geologic features investigated and depicted on the map. In addition, the map is outdated, excluding significant data from numerous studies that have been carried out since its publication more than 40 years ago. This report includes a modern digital geologic map that can be utilized with standard GIS applications to aid BBNP researchers in geologic data analysis, natural resource and ecosystem management, monitoring, assessment, inventory activities, and educational and recreational uses. The digital map incorporates new data, many revisions, and greater detail than the original map. Although some geologic issues remain unresolved for BBNP, the updated map serves as a foundation for addressing those issues. Funding for the Big Bend National Park geologic map was provided by the United States Geological Survey (USGS) National Cooperative Geologic Mapping Program and the National Park Service. The Big Bend mapping project was administered by staff in the USGS Geology and Environmental Change Science Center, Denver, Colo. Members of the USGS Mineral and Environmental Resources Science Center completed investigations in parallel with the geologic mapping project. Results of these investigations addressed some significant current issues in BBNP and the U.S.-Mexico border region, including contaminants and human health, ecosystems, and water resources. Funding for the high-resolution aeromagnetic survey in BBNP, and associated data analyses and

  8. The range of interaction between DNA-bending proteins is controlled by the second-longest correlation length for bending fluctuations

    Science.gov (United States)

    2013-01-01

    When a DNA molecule is stretched, the zero-force correlation length for its bending fluctuations – the persistence length A – bifurcates into two different correlation lengths - the shorter “longitudinal” correlation length ξ‖(f) and the longer “transverse” correlation length ξ⊥(f). In the high-force limit, ξ‖(f)=ξ⊥(f)/2=kBTA/f/2. When DNA-bending proteins bind to the DNA molecule, there is an effective interaction between the protein-generated bends mediated by DNA elasticity and bending fluctuations. Surprisingly, the range of this interaction is not the longest correlation length associated with transverse fluctuations of the tangent vector along the polymer, but instead is the second longest longitudinal correlation length ξ‖ (f, μ). The effect arises from the protein-bend contribution to the Hamiltonian having an axial rotational symmetry which eliminates its coupling to the transverse fluctuations. PMID:23368394

  9. Comparison of Radiographic Postoperative Outcomes Between Males and Females With AIS.

    Science.gov (United States)

    Xu, Ximing; Wang, Fei; Zhou, Xiaoyi; Cheng, Yajun; Wei, Xianzhao; Bai, Yushu; Li, Ming

    2015-10-01

    The primary aim was to compare postoperative radiographic outcomes between sexes among adolescent idiopathic scoliosis (AIS) patients. A total of 162 AIS patients (42 males and 120 females) undergoing pedicle screw instrumentation and posterior fusion were included. Coronal and sagittal curves and flexibilities were measured and calculated. The postoperative correction rate (CR), fulcrum bending correction index (FBCI), and Cincinnati correction index were evaluated to compare the surgical benefits between sexes.Males were older (16.79 vs 14.79 years, respectively; P traction flexibility percentage: 35.48 vs 36.98, respectively, P = 0.98; fulcrum bending flexibility percentage: 56.13 vs 66.57, respectively, P lumbar lordosis was noted in males than in females (40.05° vs 45.72°, respectively; P = 0.03), yet no statistically significant differences in the preoperative and postoperative sagittal curves were observed between the sexes. In conclusion, considering the preoperative flexibilities, the 2 sexes achieved comparable surgical benefits without sacrificing the sagittal balance.

  10. Bending dynamics of semi-flexible macromolecules in isotropic turbulence

    CERN Document Server

    Ali, Aamir; Vincenzi, Dario

    2014-01-01

    We study the Lagrangian dynamics of semi-flexible macromolecules in laminar as well as in homogeneous and isotropic turbulent flows by means of analytically solvable stochastic models and direct numerical simulations. The statistics of the bending angle is qualitatively different in laminar and turbulent flows and exhibits a strong dependence on the topology of the velocity field. In particular, in two-dimensional turbulence, particles are either found in a fully extended or in a fully folded configuration; in three dimensions, the predominant configuration is the fully extended one.

  11. Design Analysis of the Mixed Mode Bending Sandwich Specimen

    DEFF Research Database (Denmark)

    Quispitupa, Amilcar; Berggreen, Christian; Carlsson, Leif A.

    2010-01-01

    A design analysis of the mixed mode bending (MMB) sandwich specimen for face–core interface fracture characterization is presented. An analysis of the competing failure modes in the foam cored sandwich specimens is performed in order to achieve face–core debond fracture prior to other failure modes....... The analysis facilitates selection of the appropriate geometry for the MMB sandwich specimen to promote debond failure. An experimental study is performed using MMB sandwich specimens with a H100 PVC foam core and E-glass–polyester faces. The results reveal that debond propagation is successfully achieved...... for the chosen geometries and mixed mode loading conditions....

  12. Wake-induced bending of two-dimensional plasma crystals

    Energy Technology Data Exchange (ETDEWEB)

    Röcker, T. B., E-mail: tbr@mpe.mpg.de; Ivlev, A. V., E-mail: ivlev@mpe.mpg.de; Zhdanov, S. K.; Morfill, G. E. [Max Planck Institute for Extraterrestrial Physics, 85741 Garching (Germany); Couëdel, L. [CNRS, Aix-Marseille-Université, Laboratoire de Physique des Interactions Ioniques et Moléculaires, UMR 7345, 13397 Marseille Cedex 20 (France)

    2014-07-15

    It is shown that the wake-mediated interactions between microparticles in a two-dimensional plasma crystal affect the shape of the monolayer, making it non-flat. The equilibrium shape is calculated for various distributions of the particle number density in the monolayer. For typical experimental conditions, the levitation height of particles in the center of the crystal can be noticeably smaller than at the periphery. It is suggested that the effect of wake-induced bending can be utilized in experiments, to deduce important characteristics of the interparticle interaction.

  13. Wake-induced bending of two-dimensional plasma crystals

    CERN Document Server

    Röcker, T B; Zhdanov, S K; Couëdel, L; Morfill, G E

    2014-01-01

    It is shown that the wake-mediated interactions between microparticles in a two-dimensional plasma crystal affect the shape of the monolayer, making it non-flat. The equilibrium shape is calculated for various distributions of the particle number density in the monolayer. For typical experimental conditions, the levitation height of particles in the center of the crystal can be noticeably smaller than at the periphery. It is suggested that the effect of wake-induced bending can be utilized in experiments, to deduce important characteristics of the interparticle interaction.

  14. NONLINEAR BENDING THEORY OF DIAGONAL SQUARE PYRAMID RETICULATED SHALLOW SHELLS

    Institute of Scientific and Technical Information of China (English)

    肖潭; 刘人怀

    2001-01-01

    Double-deck reticulated shells are a main form of large space structures. One of the shells is the diagonal square pyramid reticulated shallow shell, whose its upper and lower faces bear most of the load but its core is comparatively flexible. According to its geometrical and mechanical characteristics, the diagonal square pyramid reticulated shallow shell is treated as a shallow sandwich shell on the basis of three basic assumptions. Its constitutive relations are analyzed from the point of view of energy and internal force equivalence. Basic equations of the geometrically nonlinear bending theory of the diagonal square pyramid reticulated shallow shell are established by means of the virtual work principle .

  15. Tensile and bending fatigue of the adhesive interface to dentin.

    Science.gov (United States)

    Belli, Renan; Baratieri, Luiz Narciso; Braem, Marc; Petschelt, Anselm; Lohbauer, Ulrich

    2010-12-01

    The aim of this study was to evaluate the fatigue limits of the dentin-composite interfaces established either with an etch-and-rinse or an one-step self-etch adhesive systems under tensile and bending configurations. Flat specimens (1.2 mm×5 mm×35 mm) were prepared using a plexiglass mold where dentin sections from human third molars were bonded to a resin composite, exhibiting the interface centrally located. Syntac Classic and G-Bond were used as adhesives and applied according to the manufacturer's instructions. The fluorochrome Rhodamine B was added to the adhesives to allow for fractographic evaluation. Tensile strength was measured in an universal testing machine and the bending strength (n=15) in a Flex machine (Flex, University of Antwerp, Belgium), respectively. Tensile (TFL) and bending fatigue limits (BFL) (n=25) were determined under wet conditions for 10(4) cycles following a staircase approach. Interface morphology and fracture mechanisms were observed using light, confocal laser scanning and scanning electron microscopy. Statistical analysis was performed using three-way ANOVA (mod LSD test, pbending characteristic strengths at 63.2% failure probability for Syntac were 23.8 MPa and 71.5 MPa, and 24.7 MPa and 72.3 MPa for G-Bond, respectively. Regarding the applied methods, no significant differences were detected between adhesives. However, fatigue limits for G-Bond (TFL=5.9 MPa; BFL=36.2 MPa) were significantly reduced when compared to Syntac (TFL=12.6 MPa; BFL=49.7 MPa). Fracture modes of Syntac were generally of adhesive nature, between the adhesive resin and dentin, while G-Bond showed fracture planes involving the adhesive-dentin interface and the adhesive resin. Cyclic loading under tensile and bending configurations led to a significant strength degradation, with a more pronounced fatigue limit decrease for G-Bond. The greater decrease in fracture strength was observed in the tensile configuration. Copyright © 2010 Academy of Dental

  16. Experimental Study Regarding of Bending Behaviour of Stabilizator Link

    Science.gov (United States)

    Cofaru, Nicolae; Roman, Lucian; Pascu, Adrian; Oleksik, Valentin

    2016-12-01

    This paper presents an experimental study of the behavior of anti-roll power link subjected to bending, power link coming from an Opel Astra G. The power link is made of PA66 GF30 polyamide. For this study, there were used a universal testing machine (Instron 5587) and a real-time strain measurement optical system (Aramis). The results showed are those obtained in the case of a compression force of 1,000 [N] namely: major Strain ɛ1, minor strain ɛ2, equivalent von Mises strain, displacement on X axis, displacement on Y axis (compression force direction), displacement on Z axis.

  17. Analyzing refractive index changes and differential bending in microcantilever arrays

    Science.gov (United States)

    Huber, François; Lang, Hans Peter; Hegner, Martin; Despont, Michel; Drechsler, Ute; Gerber, Christoph

    2008-08-01

    A new microcantilever array design is investigated comprising eight flexible microcantilevers introducing two solid bars, enabling to subtract contributions from differences in refractive index in an optical laser read out system. Changes in the refractive index do not contribute undesirably to bending signals at picomolar to micromolar DNA or protein concentrations. However, measurements of samples with high salt concentrations or serum are affected, requiring corrections for refractive index artifacts. Moreover, to obtain a deeper understanding of molecular stress formation, the differential curvature of cantilevers is analyzed by positioning the laser spots along the surface of the levers during pH experiments.

  18. Transverse bending waves and the breaking broomstick demonstration

    Science.gov (United States)

    Vandegrift, Guy

    1997-06-01

    When a broomstick is supported at both ends by two wine glasses, a strong downward blow to the center will break the stick, leaving the wine glasses undisturbed, provided care is taken to cushion the wine glasses against an initial and brief downward motion of the ends of the broomstick. This downward motion is analyzed and estimated to be about 1 mm in magnitude. Qualitative experimental evidence of this motion is easily obtained using a force probe to monitor a light and nondestructive tap to a 2-m measuring stick. The method of analysis developed here leads to a simple derivation of the dispersion relation for transverse bending waves on a long rod.

  19. Reflection of bending Waves from Border of the Plate

    Directory of Open Access Journals (Sweden)

    Belubekyan M.V.

    2010-03-01

    Full Text Available To problems of the reflection of the bending waves from flat border of the ambience dedicated to the multiple studies. Relatively little works are connected with questions of the reflection curved waves from flat edge of the thin plate. In this work happen to the decisions of the problem of the plate under different border condition. For partial case of the free edge, as limiting case of the absence of the reflected wave, is got decision of the problem localized curved variations.

  20. TRAPEZOIDAL PLATE BENDING ELEMENT WITH DOUBLE SET PARAMETERS

    Institute of Scientific and Technical Information of China (English)

    Shao-chun Chen; Dong-yang Shi; I chiro Hagiwara

    2003-01-01

    Using double set parameter method, a 12-parameter trapezoidal plate bending element is presented. The first set of degrees of freedom, which make the element convergent, are the values at the four vertices and the middle points of the four sides together with the mean values of the outer normal derivatives along four sides. The second set of degree of freedom, which make the number of unknowns in the resulting discrete system small and computation convenient are values and the first derivatives at the four vertices of the element. The convergence of the element is proved.

  1. Bending Under Tension Test with Direct Friction Measurement

    DEFF Research Database (Denmark)

    Andreasen, Jan Lasson; Olsson, David Dam; Chodnikiewicz, K.

    2006-01-01

    A special Bending-Under-Tension (BUT) transducer has been developed in which friction around the tool radius can be directly measured when drawing a plane sheet strip around a cylindrical tool-pin under constant back tension. The front tension, back tension and torque on the tool-pin are all...... measured directly, thus enabling accurate measurement of friction and direct determination of lubricant film breakdown for varying normal pressure, sliding speed, tool radius and tool preheat temperature. The transducer is applied in an experimental investigation focusing on limits of lubrication...... in drawing of stainless steel showing the influence of varying process conditions and the performance of different lubricants....

  2. Mechano sorptive behaviour of notched beams in bending

    DEFF Research Database (Denmark)

    Jensen, Signe Kamp; Hoffmeyer, Preben

    1996-01-01

    Short term bending tests with end-notched beams at constant or varying moisture content have shown an apparent contradictory dependency between moisture content and strength. The higher the moisture content the higher the strength. Varying moisture results in particularly significant differences...... and by neglecting deformation due to shear. Compression stresses perpendicular to grain in excess of 6 MPa were found in the vicinity of the notch following a period of adsorption. Similarly, small tension stresses of the order 1 MPa were registered in this area when the specimens were at their most dry condition...

  3. Tilted bending magnet for SPS target area TCC2

    CERN Multimedia

    1976-01-01

    A slow-extracted proton beam from the SPS goes to the underground target zone TCC2. The part of the primary beam which traverses target T4 is recuperated and transported over some 800 m, for further use in the North Area High Intensity facility (NAHIF). The curved and sloped trajectory required 4 of the bending magnets to be tilted. Here we see one of them being attended by Gilbert Françon in hall 867, ready for installation in TCC2.

  4. The effect of preoperative Lugol's iodine on intraoperative bleeding in patients with hyperthyroidism

    Directory of Open Access Journals (Sweden)

    Yeliz Yilmaz

    2016-08-01

    Conclusion: Preoperative Lugol solution treatment was found to be a significant independent determinant of intraoperative blood loss. Moreover, preoperative Lugol solution treatment decreased the rate of blood flow, and intraoperative blood loss during thyroidectomy.

  5. Effect of preoperative neuromuscular training (NEMEX-TJR) on functional outcome after total knee replacement

    DEFF Research Database (Denmark)

    Huber, Erika O; Roos, Ewa M.; Meichtry, André

    2015-01-01

    BACKGROUND: Improving functional status preoperatively through exercise may improve postoperative outcome. Previous knowledge on preoperative exercise in knee osteoarthritis is insufficient. The aim of the study was to compare the difference in change between groups in lower extremity function fr...

  6. Effect of preoperative education on recovery time of laparoscopic cholecystectomy: a randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Leila Sadati

    2014-07-01

    Conclusion: Preoperative education of patients can significantly decrease the recovery time after laparoscopic cholecystectomy surgery. Therefore, it is strongly recommended to include the preoperative education in routine care of laparoscopic cholecystectomy patients for better surgical outcomes.

  7. 77 FR 70484 - Preoperational Testing of Onsite Electric Power Systems To Verify Proper Load Group Assignments...

    Science.gov (United States)

    2012-11-26

    ... COMMISSION Preoperational Testing of Onsite Electric Power Systems To Verify Proper Load Group Assignments... Power Systems to Verify Proper Load Group Assignments, Electrical Separation, and Redundancy.'' DG-1294... encompass preoperational testing of electrical power systems used to meet current Station...

  8. Validation of the French version of the Amsterdam preoperative anxiety and information scale (APAIS)

    National Research Council Canada - National Science Library

    Maurice-Szamburski, Axel; Loundou, Anderson; Capdevila, Xavier; Bruder, Nicolas; Auquier, Pascal

    2013-01-01

    .... The Amsterdam Preoperative Anxiety and Information Scale (APAIS) is a self-report questionnaire comprising six questions that have been developed and validated to evaluate the preoperative anxiety of patients...

  9. Methodology for definition of bending radius and pullback force in HDD (Horizontal Directional Drilling) operations

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Danilo Machado L. da; Rodrigues, Marcos V. [Det Norske Veritas (DNV), Rio de Janeiro, RJ (Brazil); Venaas, Asle [Det Norske Veritas (DNV), Oslo (Norway); Medeiros, Antonio Roberto de [Subsea 7 (Brazil)

    2009-12-19

    Bending is a primary loading experienced by pipelines during installation and operation. Significant bending in the presence of tension is experienced during installation by the S-lay method, as the pipe conforms to the curvature of the stinger and beyond in the over bend region. Bending in the presence of external pressure is experienced in the sag bend of all major installation methods (e.g., reeling, J-lay, S-lay) as well as in free-spans on the sea floor. Bending is also experienced by pipelines during installation by horizontal directional drilling. HDD procedures are increasingly being utilized around the world not only for crossings of rivers and other obstacles but also for shore approach of offshore pipelines. During installation the pipeline experience a combination of tensile, bending, and compressive stresses. The magnitude of these stresses is a function of the approach angle, bending radius, pipe diameter, length of the borehole, and the soil properties at the site. The objective of this paper is to present an overview of some aspects related to bending of the product pipe during HDD operations, which is closely related to the borehole path as the pipeline conforms to the curvature of the hole. An overview of the aspects related to tensile forces is also presented. The combined effect of bending and tensile forces during the pullback operation is discussed. (author)

  10. A Novel Low-Cost, Large Curvature Bend Sensor Based on a Bowden-Cable.

    Science.gov (United States)

    Jeong, Useok; Cho, Kyu-Jin

    2016-06-24

    Bend sensors have been developed based on conductive ink, optical fiber, and electronic textiles. Each type has advantages and disadvantages in terms of performance, ease of use, and cost. This study proposes a new and low-cost bend sensor that can measure a wide range of accumulated bend angles with large curvatures. This bend sensor utilizes a Bowden-cable, which consists of a coil sheath and an inner wire. Displacement changes of the Bowden-cable's inner wire, when the shape of the sheath changes, have been considered to be a position error in previous studies. However, this study takes advantage of this position error to detect the bend angle of the sheath. The bend angle of the sensor can be calculated from the displacement measurement of the sensing wire using a Hall-effect sensor or a potentiometer. Simulations and experiments have shown that the accumulated bend angle of the sensor is linearly related to the sensor signal, with an R-square value up to 0.9969 and a root mean square error of 2% of the full sensing range. The proposed sensor is not affected by a bend curvature of up to 80.0 m(-1), unlike previous bend sensors. The proposed sensor is expected to be useful for various applications, including motion capture devices, wearable robots, surgical devices, or generally any device that requires an affordable and low-cost bend sensor.

  11. Numberical Investigation of a New Method for Reducing Bends Erosion from Particles Impacts

    Institute of Scientific and Technical Information of China (English)

    YAOJun; FANJianren; 等

    2002-01-01

    The present paper intends to introduce a new method for reducing bends erosion from particles impacts: the ribbed bend erosion protection method. Ribs are evenly fixed in the range of 20°-80° on the inner-wall of inside 90° bend and the bend (including ribs) is made of medium carbon steel. Three-dimensional numerical work is performed and the result shows satisfactory agreement with the experimental measurement. Numerical simulation studies the characteristics of axial gas flow along the bend and secondary flow at cross section. Detailed analyses involving the impact velocity and incidence angle of particle-metal (either particle-rib or particle-duct) impact unveil the mechanism of the anti-erosion effect. As a result, predications achieve that the average erosion rate of the ribbed bends is only a third of the bare bend under test conditions and rectangle ribs possess higher anti-erosion effect than square ribs, while the wear distribution pattern remains unchanged after adding ribs onto the bend. All results confirm that the ribbed bend erosion protection method is a simple and effective method for reducing bends erosion from particles impacts.

  12. Ranitidine improves postoperative suppression of antibody response to preoperative vaccination

    DEFF Research Database (Denmark)

    Nielsen, Hans Jørgen; Hammer, J H; Moesgaard, F;

    1992-01-01

    The effect of the histamine-2 receptor antagonist ranitidine (100 mg intravenously every 12 hours for 72 hours) on postoperative serum antibody responses to preoperative immunization with six limit of flocculation tetanus toxoid and six limit of flocculation diphtheria toxoid was assessed...... in a double-blind, placebo-controlled randomized study in 26 patients undergoing major abdominal surgery. The preoperative antitetanus antibody level was less than 0.1 IU/ml in all patients, and they were inoculated with both antigens 48 hours before surgery. Serum samples for analysis of antitetanus toxoid...... and antidiphtheria toxoid were drawn before skin incision and on postoperative days 1, 3, 5, 7, 10, 14, 21, and 28. Ranitidine significantly increased the postoperative antibody response to tetanus toxoid, (p less than 0.01) and insignificantly increased that to diphtheria toxoid vaccination (p less than 0...

  13. Preoperative Diagnosis of Adult Intussusception Caused by Small Bowel Lipoma

    Directory of Open Access Journals (Sweden)

    Hiroaki Shiba

    2009-11-01

    Full Text Available Adult intussusception is rare, accounting for only 5% of all intussusceptions, for which preoperative diagnosis is difficult. We herein report a preoperatively diagnosed case of adult intussusception caused by a small bowel lipoma. A 33-year-old man was admitted to our hospital with three weeks history of colicky epigastric pain. Computed tomography revealed thickening of the ileal wall suggestive of intussusception. Colonoscopy revealed an ileocolic intussusception. Barium enema for reduction of ileocolic intussusception demonstrated a small bowel tumor in the ileum 15 cm proximal to the ileocecal valve. The intussusception was reduced, and the patient underwent partial resection of the ileum encompassing the small bowel tumor. Histological findings confirmed the diagnosis of lipoma of the small bowel. The patient made a satisfactory recovery and remains well.

  14. Pre-operative pain and sensory function in groin hernia

    DEFF Research Database (Denmark)

    Aasvang, Eske K; Hansen, Jeanette B; Kehlet, Henrik

    2009-01-01

    mechanism. AIMS: To investigate the correlation between pre-operative pain intensity and sensory functions in the groin hernia area. METHODS: Patients with unilateral groin hernia were examined preoperatively by quantitative sensory testing (thermal, mechanical, and pressure [detection and pain thresholds...... (rho=-0.413, p=0.049), indicating a paradoxical association between level of mechanical pain threshold and magnitude of spontaneous pain. No other sensory modality was significantly correlated to pain intensity. New/increased pain during repetitive pinprick stimulation (wind-up) was seen in 3 patients......]) and assessments were correlated to patients' reports of intensity and frequency of spontaneous pain in the groin area. RESULTS: Forty-two patients were examined, whereof one was excluded since no hernia was found intraoperatively. Mechanical pain threshold was inversely correlated with spontaneous pain intensity...

  15. PREOPERATIVE SEGMENTAL LOCALIZATION OF FOCAL HEPATIC LESION ON MRI

    Institute of Scientific and Technical Information of China (English)

    陈正光; 苏学曾; 欧阳汉; 孟涛; 袁兴华; 邵永孚

    1995-01-01

    In order to evaluate the accuracy of preoperative segmental localization of hepatic mass lesinns,68 cases were prospectively studied and evaluated by the correlation of magnetic resonance imaging(MRI) and surgical findings. Right, middle and left hepatic veins were seen in 100%, 97% and 94% of the subjects respectively on MRI, The right and left portal veins were seen in 100% and 95. 6% respectively. The accuracy in determining the segmental location of hepatic lesions was 89. 7%. The accuracy could be increased to 91.3% if the lesion was located at single segment whereas it was only 86. 4% when the lesion extended across several segments. It is possible to say that MRI is an important modality in the preoperative segmental localization of masses.

  16. Preoperative diagnosis of carcinoma within fibroadenoma on screening mammograms.

    Science.gov (United States)

    Borecky, N; Rickard, M

    2008-02-01

    Three cases of fibroadenoma associated with carcinoma are reported. These cases were diagnosed within a screening programme as a result of suspicious mammographic findings, and the diagnosis of malignancy was confirmed preoperatively by core biopsy in all cases. The mammographic findings suggestive of carcinoma within fibroadenoma were irregularity of margins in one case and associated new suspicious pleomorphic and linear calcifications in the two other cases. The preoperative diagnosis of carcinoma within fibroadenoma was provided by ultrasound-guided core biopsy in two cases and core biopsy under stereotactic guidance in one case. Whereas asymptomatic fibroadenoma with benign imaging appearances usually does not require further investigation, fibroadenoma with atypical imaging features requires a triple test investigation.

  17. Asian Rhinoplasty: Preoperative Simulation and Planning Using Adobe Photoshop.

    Science.gov (United States)

    Kiranantawat, Kidakorn; Nguyen, Anh H

    2015-11-01

    A rhinoplasty in Asians differs from a rhinoplasty performed in patients of other ethnicities. Surgeons should understand the concept of Asian beauty, the nasal anatomy of Asians, and common problems encountered while operating on the Asian nose. With this understanding, surgeons can set appropriate goals, choose proper operative procedures, and provide an outcome that satisfies patients. In this article the authors define the concept of an Asian rhinoplasty-a paradigm shift from the traditional on-top augmentation rhinoplasty to a structurally integrated augmentation rhinoplasty-and provide a step-by-step procedure for the use of Adobe Photoshop as a preoperative program to simulate the expected surgical outcome for patients and to develop a preoperative plan for surgeons.

  18. Combined modality preoperative therapy for unresectable rectal cancer.

    Science.gov (United States)

    Percarpio, B; Bitterman, J; Sabbath, K; Alfano, F; Ruszkowski, R; Bowen, J

    1992-01-01

    Locally advanced rectal cancer has been a surgical challenge because of fixation of the primary tumor to the boney pelvis or to other pelvic soft tissues. During a 12-month period seven patients with locally advanced adenocarcinoma of the rectum were treated preoperatively with simultaneous pelvic irradiation (4500-5040 cGy) and infusion chemotherapy (5-fluorouracil 1000 mg per m2 per day over 96 hours and mitomycin 10 mg per m2. Tolerance was reasonable and all patients underwent successful resection of the primary lesion. Two patients had a complete response to preoperative combined modality therapy with no cancer found in the surgical specimen. With a short follow-up period, all patients have experienced satisfactory healing and none have suffered local or distant recurrence. The results of this limited series are encouraging for future clinical trials.

  19. Assessment of spiral CT pneumocolon in preoperative colorectal carcinoma

    Institute of Scientific and Technical Information of China (English)

    Can-Hui Sun; Zi-Ping Li; Quan-Fei Meng; Shen-Ping Yu; Da-Sheng Xu

    2005-01-01

    AIM: To investigate the value of spiral CT pneumocolon in preoperative colorectal carcinoma.METHODS: Spiral CT pneumocolon was performed prior to surgery in 64 patients with colorectal carcinoma. Spiral CT images were compared to specimens from the resected tumor.RESULTS: Spiral CT depicted the tumor in all patients.Comparison of spiral CT and histologic results showed that the sensitivity and specificity were 95.2%, 40.9% in detection of local invasion, and 75.0%, 90.9% in detection of lymph node metastasis. Compared to the Dukes classification,the disease was correctly staged as A in 6 of 18 patients,as B in 18 of 23, as C in 10 of 15, and as D in 7 of 8. Overall,spiral CT correctly staged 64.1% of patients.CONCLUSION: Spiral CT pneumocolon may be useful in the preoperative assessment of patients with colorectal carcinoma as a means for assisting surgical planning.

  20. Identifying and assessing anxiety in pre-operative patients.

    Science.gov (United States)

    Pritchard, Michael John

    Increasing demands for hospitals to be more efficient mean that patients attending for an operation are generally admitted on the day of surgery. As a result, healthcare professionals have little time to talk to the patient to ascertain his or her wellbeing, to check for any signs of anxiety and ask whether the patient requires further information about the forthcoming procedure. Healthcare professionals should be encouraged to use appropriate interventions to identify and assess anxious patients. There are several instruments available to measure the patient's level of pre-operative anxiety. This article reviews the Amsterdam Preoperative Anxiety and Information Scale, which is easy for patients to complete and may help to identify which individuals need extra support.

  1. Necrotizing fasciitis: unreliable MRI findings in the preoperative diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Arslan, Arzu E-mail: arzuarslan@netscape.net; Pierre-Jerome, Claude; Borthne, Arne

    2000-12-01

    The authors present two cases of necrotizing fasciitis (NF), one case of dermatomyositis and one case of posttraumatic muscle injury, which have similar magnetic resonance imaging findings in terms of skin, subcutaneous fat, superficial and deep fasciae and muscle involvement. These cases highlight the need for cautious interpretation of magnetic resonance imaging (MRI) findings, for they are nonspecific and the preoperative decision should be based mostly on the evolution of the clinical status.

  2. Outpatient Preoperative Education Needs Identified by Nurses and Patients.

    Science.gov (United States)

    2007-11-02

    PREOPERATIVE EDUCATION NEEDS IDENTIFIED BY NURSES AND PATIENTS Cheryl Anne Reilly APPROVED: Supervising Prdessor Date APPROVED: / "Sanfor• Miller , P... anesthesiologist will visit them before 5 4 3 2 1 surgery to discuss what anesthesia would be used. 27. Their incision may pull, bum, or itch while it is 5 4...such as, giving me an injection & asking me to empty my bladder. 26. An anesthesiologist would visit me before Yes No 5 4 3 2 1 surgery to discuss

  3. Preoperative Patient Education for Hip and Knee Arthroplasty: Financial Benefit?

    Science.gov (United States)

    Tait, Mark A; Dredge, Carter; Barnes, C Lowry

    2015-01-01

    Of 904 patients who underwent primary total knee arthroplasty (TKA) and total hip arthroplasty (THA) at the same hospital, 802 participated in a preoperative education day called "Joint Academy" (JA). The length of stay of JA participants was 2.12 days (49.5%) less than patients who did not attend a JA (p education program may significantly reduce overall costs for primary TKA and THA procedures.

  4. The pelvic support osteotomy: indications and preoperative planning

    OpenAIRE

    Pafilas, Dimitrios; Nayagam, Selvadurai

    2008-01-01

    The pelvic support osteotomy is a double level femoral osteotomy with the objective of eliminating a Trendelenburg and short limb gait in young patients with severe hip joint destruction as a consequence of neonatal septic arthritis. The osteotomy has seen several changes and a brief historical overview is provided to set the evolution of the modifications of the procedure in context. We present an analysis of the preoperative assessment that will assist the surgeon to plan out the procedure....

  5. Preoperative easily misdiagnosed telangiectatic osteosarcoma: clinical–radiologic–pathologic correlations

    Science.gov (United States)

    Gao, Zhen-Hua; Yin, Jun-Qiang; Liu, Da-Wei; Meng, Quan-Fei

    2013-01-01

    Abstract Purpose: To describe the clinical, imaging, and pathologic characteristics and diagnostic methods of telangiectatic osteosarcoma (TOS) for improving the diagnostic level. Materials and methods: The authors retrospectively reviewed patient demographics, serum alkaline phosphatase (AKP) levels, preoperative biopsy pathologic reports, pathologic materials, imaging findings, and treatment outcomes from 26 patients with TOS. Patient images from radiography (26 cases) and magnetic resonance (MR) imaging (22 cases) were evaluated by 3 authors in consensus for intrinsic characteristics. There were 15 male and 11 female patients in the study, with an age of 9–32 years (mean age 15.9 years). Results: Eighteen of 26 patients died of lung metastases within 5 years of follow-up. The distal femur was affected more commonly (14 cases, 53.8%). Regarding serum AKP, normal (8 cases) or mildly elevated (18 cases) levels were found before preoperative chemotherapy. Radiographs showed geographic bone lysis without sclerotic margin (26 cases), cortical destruction (26 cases), periosteal new bone formation (24 cases), soft-tissue mass (23 cases), and matrix mineralization (4 cases). The aggressive radiographic features of TOS simulated the appearance of conventional high-grade intramedullary osteosarcoma, though different from aneurysmal bone cyst. MR images demonstrated multiple big (16 cases) or small (6 cases) cystic spaces, fluid-fluid levels (14 cases), soft-tissue mass (22 cases), and thick peripheral and septal enhancement (22 cases). Nine of 26 cases were misdiagnosed as aneurysmal bone cysts by preoperative core-needle biopsy, owing to the absence of viable high-grade sarcomatous cells in the small tissue samples. Conclusion: The aggressive growth pattern with occasional matrix mineralization, and multiple big or small fluid-filled cavities with thick peripheral, septal, and nodular tissue surrounding the fluid-filled cavities are characteristic imaging features of

  6. Preoperative administration of cephalosporins for elective caesarean delivery

    Directory of Open Access Journals (Sweden)

    Bogavac Mirjana

    2010-01-01

    Full Text Available Introduction. Antibiotic prophylaxis means administration of antibiotics in prevention of infections. Objective. To investigate the efficacy of a single dose preoperative administration of ceftriaxone and cefazolin in the prevention of intra- and postoperative infections in the parturients without high risk of inflammation. Methods. The first group of 45 pregnant and 4 non-pregnant women were preoperatively administered ceftriaxone in a dose of 2 g, i.v., 10 minutes before the planned surgery. The second group of 45 pregnant and 4 non-pregnant women were preoperatively administered cefazolin in a dose of 2 g i.v., 10 minutes before the planned surgery. The concentrations of antibiotics were estimated immediately and 6 hours following the operation, as well as in the amniotic fluid and umbilical cord in the group of pregnant women. The estimation of antibiotic concentration was done by the method of liquid chromatography. Results. The mean concentrations of antibiotics in the patients following the elective caesarean section were as follows: ceftriaxone - 22.7 μg/l. vs cefazolin - 44.8 μg/l. Six hours later, the concentration of antibiotic decreased, but the concentration of cefazolin was still over the MIC for sensitive bacteria. The mean concentrations of antibiotics following gynaecological surgery in the non-pregnant patients were as follows: ceftriaxone - 12.0 μg/l vs cefazolin - 30.1 μg/l. Six hours later, the concentration of antibiotic decreased. Conclusion. It is most optimal to administer a single-dose of the first generation cephalosporins-cefazolin-immediately following the clamping of the umbilical cord as well as in preoperative prophylaxis in gynaecological operations.

  7. Preoperative embolization of primary bone tumors: A case control study

    Science.gov (United States)

    Jha, Roushan; Sharma, Raju; Rastogi, Shishir; Khan, Shah Alam; Jayaswal, Arvind; Gamanagatti, Shivanand

    2016-01-01

    AIM: To study the safety and effectiveness of preoperative embolization of primary bone tumors in relation to intraoperative blood loss, intraoperative blood transfusion volume and surgical time. METHODS: Thirty-three patients underwent preoperative embolization of primary tumors of extremities, hip or vertebrae before resection and stabilization. The primary osseous tumors included giant cell tumors, aneurysmal bone cyst, osteoblastoma, chondroblastoma and chondrosarcoma. Twenty-six patients were included for the statistical analysis (embolization group) as they were operated within 0-48 h within preoperative embolization. A control group (non-embolization group, n = 28) with bone tumor having similar histological diagnosis and operated without embolization was retrieved from hospital record for statistical comparison. RESULTS: The mean intraoperative blood loss was 1300 mL (250-2900 mL), the mean intraoperative blood transfusion was 700 mL (0-1400 mL) and the mean surgical time was 221 ± 76.7 min for embolization group (group I, n = 26). Non-embolization group (group II, n = 28), the mean intraoperative blood loss was 1800 mL (800-6000 mL), the mean intraoperative blood transfusion was 1400 mL (700-8400 mL) and the mean surgical time was 250 ± 69.7 min. On comparison, statistically significant (P < 0.001) difference was found between embolisation group and non-embolisation group for the amount of blood loss and requirement of blood transfusion. There was no statistical difference between the two groups for the surgical time. No patients developed any angiography or embolization related complications. CONCLUSION: Preoperative embolization of bone tumors is a safe and effective adjunct to the surgical management of primary bone tumors that leads to reduction in intraoperative blood loss and blood transfusion volume. PMID:27158424

  8. Preoperative thrombocytosis and poor prognostic factors in endometrial cancer.

    Science.gov (United States)

    Heng, Suttichai; Benjapibal, Mongkol

    2014-01-01

    This study aimed to evaluate the prevalence of preoperative thrombocytosis and its prognostic significance in Thai patients with endometrial cancer. We retrospectively reviewed the medical records of 238 cases who had undergone surgical staging procedures between January 2005 and December 2008. Associations between clinicopathological variables and preoperative platelet counts were analyzed using Pearson's chi square or two- tailed Fisher's exact tests. Survival analysis was performed with Kaplan-Meier estimates. Univariate and Cox- regression models were used to evaluate the prognostic impact of various factors including platelet count in terms of disease-free survival and overall survival. The mean preoperative platelet count was 315,437/μL (SD 100,167/ μL). Patients who had advanced stage, adnexal involvement, lymph node metastasis, and positive peritoneal cytology had significantly higher mean preoperative platelet counts when compared with those who had not. We found thrombocytosis (platelet count greater than 400,000/μL) in 18.1% of our patients with endometrial cancer. These had significant higher rates of advanced stage, cervical involvement, adnexal involvement, positive peritoneal cytology, and lymph node involvement than patients with a normal pretreatment platelet count. The 5-year disease-free survival and overall survival were significantly lower in patients who had thrombocytosis compared with those who had not (67.4% vs. 85.1%, p=0.001 and 86.0% vs. 94.9%, p=0.034, respectively). Thrombocytosis was shown to be a prognostic factor in the univariate but not the multivariate analysis. In conclusion, presence of thrombocytosis is not uncommon in endometrial cancer and may reflect unfavorable prognostic factors but its prognostic impact on survival needs to be clarified in further studies.

  9. Bending continuous structures with SMAs: a novel robotic fish design.

    Science.gov (United States)

    Rossi, C; Colorado, J; Coral, W; Barrientos, A

    2011-12-01

    In this paper, we describe our research on bio-inspired locomotion systems using deformable structures and smart materials, concretely shape memory alloys (SMAs). These types of materials allow us to explore the possibility of building motor-less and gear-less robots. A swimming underwater fish-like robot has been developed whose movements are generated using SMAs. These actuators are suitable for bending the continuous backbone of the fish, which in turn causes a change in the curvature of the body. This type of structural arrangement is inspired by fish red muscles, which are mainly recruited during steady swimming for the bending of a flexible but nearly incompressible structure such as the fishbone. This paper reviews the design process of these bio-inspired structures, from the motivations and physiological inspiration to the mechatronics design, control and simulations, leading to actual experimental trials and results. The focus of this work is to present the mechanisms by which standard swimming patterns can be reproduced with the proposed design. Moreover, the performance of the SMA-based actuators' control in terms of actuation speed and position accuracy is also addressed.

  10. Pressure and bending tests on fibreglass augmented steel technology pipes

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Qishi; Ozkan, Istemi F. [C-FER Technologies, Edmonton, Alberta, (Canada); Salama, Mamdouh M. [ConocoPhillips Company, Houston, Texas, (United States)

    2010-07-01

    The economic manufacture of large diameter high pressure pipelines is a challenge. The FAST-PipeTM concept is fabricated from a steel liner hoop-wound with non-impregnated fibreglass stands. This report presents the qualification results of the FAST-PipeTM concept. The qualification testing program studied the effects of external environment (frozen/thawed cycle), load duration and the wrap thickness on the burst and bending capacity of the FAST-PipeTM concept. Burst and pressure-bend tests were performed under different conditions and for different thickness of fibreglass. The values obtained were compared to those from unwrapped pipes. It also established FAST-PipeTM behaviour in several loading scenarios using the FEA model. The burst tests results showed that freezing temperatures do not have an impact on the pressure capacity of FAST-PipeTM. The results of the tests showed the effectiveness of dry fibreglass wrap in increasing the internal pressure capacity of the pipe.

  11. How Does The Bone Shaft Geometry Affect its Bending Properties?

    Directory of Open Access Journals (Sweden)

    Kaveh P. Saffar

    2009-01-01

    Full Text Available In this research, ten fresh specimens of sheep tibiae were provided from slaughtered animals. Whole bone specimens were loaded in three-point bending according to standard wet bone test protocols. Mechanical properties were determined and compared with the results which were obtained from two dry bone tests. The results showed that fracture bending moment and bone extrinsic stiffness had significant relations with fracture cross-section dependent parameters (i.e., cross-section area and area moment of inertia. Where, fracture energy and ultimate strength did not have such a relation with these parameters. Finite element modeling of bone shaft was made with simplified geometry (neglecting cross-section variations along bone shaft in two steps: First, by elliptical cross-section and second, by circular cross-section, assuming linear elastic and isotropic properties for the specimens. Elastic (Young’s modulus and fracture load, evaluated from curves obtained from tests, were applied to the finite element model and close results of maximum stress in both test specimen and first (elliptical cross-section model showed up. There was an average difference of about 2% between ultimate strength of wet bone specimens and maximum (tensile stress occurred in the elliptical models. However, this value for circular models was about 16%.

  12. Relativity for everyone how space-time bends

    CERN Document Server

    Fischer, Kurt

    2015-01-01

    This book, now in a revised and updated second edition, explains the theory of special and general relativity in detail without approaching Einstein's life or the historical background. The text is formulated in such a way that the reader will be able to understand the essence intuitively, and new sections have been added on time machines, the twin paradoxes, and tensors. The first part of the book focuses on the essentials of special relativity. It explains the famous equivalence between mass and energy and tells why Einstein was able to use the theory of electrodynamics as a template for his "electrodynamics of moving bodies". General relativity is then addressed, mainly with the help of thought experiments. Reference is made to the previously introduced special relativity and the equivalence principle and, using many figures, it is explained how space-time is bending under gravity. The climax of the book is the Einstein equation of gravity, which describes the way in which matter bends space-time. The read...

  13. Optical guiding and beam bending in free-electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Scharlemann, E.T.

    1987-01-01

    The electron beam in a free-electron laser (FEL) can act as an optical fiber, guiding or bending the optical beam. The refractive and gain effects of the bunched electron beam can compensate for diffraction, making possible wigglers that are many Rayleigh ranges (i.e., characteristic diffraction lengths) long. The origin of optical guiding can be understood by examining gain and refractive guiding in a fiber with a complex index of refraction, providing a mathematical description applicable also to the FEL, with some extensions. In the exponential gain regime of the FEL, the electron equations of motion must be included, but a self-consistent description of exponential gain with diffraction fully included becomes possible. The origin of the effective index of refraction of an FEL is illustrated with a simple example of bunched, radiating dipoles. Some of the properties of the index of refraction are described. The limited experimental evidence for optical beam bending is summarized. The evidence does not yet provide conclusive proof of the existence of optical guiding, but supports the idea. Finally, the importance of refractive guiding for the performance of a high-gain tapered-wiggler FEL amplifier is illustrated with numerical simulations.

  14. Composite failure prediction of π-joint structures under bending

    Institute of Scientific and Technical Information of China (English)

    HUANG Hong-me; YUAN Shen-fang

    2012-01-01

    In this article,the composite π-joint is investigated under bending loads.The "L" preform is the critical component regarding composite π-joint failure.The study is presented in the failure detection of a carbon fiber composite π-joint structure under bending loads using fiber Bragg grating (FBG) sensor.Firstly,based on the general finite element method (FEM)software,the 3-D finite element (FE) model of composite π-joint is established,and the failure process and every lamina failure load of composite π-joint are investigated by maximum stress criteria.Then,strain distributions along the length of FBG are extracted,and the reflection spectra of FBG are calculated according to the strain distribution.Finally,to verify the numerical results,a test scheme is performed and the experimental spectra of FBG are recorded.The experimental results indicate that the failure sequence and the corresponding critical loads of failure are consistent with the numerical predictions,and the computational error of failure load is less than 6.4%.Furthermore,it also verifies the feasibility of the damage detection system.

  15. Radio occultation bending angle anomalies during tropical cyclones

    Directory of Open Access Journals (Sweden)

    R. Biondi

    2011-02-01

    Full Text Available The tropical deep convection affects the radiation balance of the atmosphere changing the water vapor mixing ratio and the temperature of the upper troposphere lower stratosphere. The aim of this work is to better understand these processes and to investigate if severe storms leave a significant signature in radio occultation profiles in the tropical tropopause layer. Using tropical cyclone best track database and data from different GPS radio occultation missions (COSMIC, GRACE, CHAMP, SACC and GPSMET, we selected 1194 profiles in a time window of 3 h and a space window of 300 km from the eye of the cyclone. We show that the bending angle anomaly of a GPS radio occultation signal is typically larger than the climatology in the upper troposphere and lower stratosphere and that a double tropopause during deep convection can easily be detected using this technique. Comparisons with co-located radiosondes, climatology of tropopause altitudes and GOES analyses are also shown to support the hypothesis that the bending angle anomaly can be used as an indicator of convective towers. The results are discussed in connection to the GPS radio occultation receiver which will be part of the Atomic Clock Ensemble in Space (ACES payload on the International Space Station.

  16. Xyloglucan for Generating Tensile Stress to Bend Tree Stem

    Institute of Scientific and Technical Information of China (English)

    Kei'ichi Baba; Yong Woo Park; Tomomi Kaku; Rumi Kaida; Miyuki Takeuchi; Masato Yoshida; Yoshihiro Hosoo; Yasuhisa Ojio; Takashi Okuyama; Toru Taniguchi; Yasunori Ohmiya; Teiji Kondo; Ziv Shani; Oded Shoseyov; Tatsuya Awano; Satoshi Serada; Naoko Norioka; Shigemi Norioka; Takahisa Hayashi

    2009-01-01

    In response to environmental variation, angiosperm trees bend their stems by forming tension wood, which consists of a cellulose-rich G (gelatinous)-Iayer in the walls of fiber cells and generates abnormal tensile stress in the sec-ondary xylem. We produced transgenic poplar plants overexpressing several endoglycanases to reduce each specific poly-saccharide in the cell wall, as the secondary xylem consists of primary and secondary wall layers. When placed horizontally, the basal regions of stems of transgenic poplars overexpressing xyloglucanase alone could not bend upward due to low strain in the tension side of the xylem. In the wild-type plants, xyloglucan was found in the inner surface of G-layers during multiple layering. In situ xyloglucan endotransglucosylase (XET) activity showed that the incorporation of whole xylo-glucan, potentially for wall tightening, began at the inner surface layers S1 and S2 and was retained throughout G-layer development, while the incorporation of xyloglucan heptasaccharide (XXXG) for wall loosening occurred in the primary wall of the expanding zone. We propose that the xyloglucan network is reinforced by XET to form a further connection between wall-bound and secreted xyloglucans in order to withstand the tensile stress created within the cellulose G-layer microfibrils.

  17. The first ANDES elements: 9-DOF plate bending triangles

    Science.gov (United States)

    Militello, Carmelo; Felippa, Carlos A.

    1991-01-01

    New elements are derived to validate and assess the assumed natural deviatoric strain (ANDES) formulation. This is a brand new variant of the assumed natural strain (ANS) formulation of finite elements, which has recently attracted attention as an effective method for constructing high-performance elements for linear and nonlinear analysis. The ANDES formulation is based on an extended parametrized variational principle developed in recent publications. The key concept is that only the deviatoric part of the strains is assumed over the element whereas the mean strain part is discarded in favor of a constant stress assumption. Unlike conventional ANS elements, ANDES elements satisfy the individual element test (a stringent form of the patch test) a priori while retaining the favorable distortion-insensitivity properties of ANS elements. The first application of this formulation is the development of several Kirchhoff plate bending triangular elements with the standard nine degrees of freedom. Linear curvature variations are sampled along the three sides with the corners as gage reading points. These sample values are interpolated over the triangle using three schemes. Two schemes merge back to conventional ANS elements, one being identical to the Discrete Kirchhoff Triangle (DKT), whereas the third one produces two new ANDES elements. Numerical experiments indicate that one of the ANDES element is relatively insensitive to distortion compared to previously derived high-performance plate-bending elements, while retaining accuracy for nondistorted elements.

  18. Electrical Bending and Mechanical Buckling Instabilities in Electrospinning Jets

    Science.gov (United States)

    Han, Tao; Reneker, Darrell H.

    2007-03-01

    The electrospinning jet was a continuous fluid flow ejected from the surface of a fluid when the applied electrical force overcomes the surface tension. The jet moved straight away from the tip and then became unstable and bent into coils. This phenomenon is the electrical bending instability [1]. When the distance between the tip and collector was reduced to less than the maximal straight segment length, the electrical bending instability did not occur. The periodic buckling of a fluid jet incident onto a surface is a striking fluid mechanical instability [2]. When axial compressive stress along the jet reached a sufficient value, it produced the fluid mechanics analogue to the buckling of a slender solid column. In the electrospinning, the buckling instability occurred just above the collector where the jet was compressed as it encountered the collector. The buckling frequencies of these jets are in the range of 10^4 to 10^5 Hz. The buckling lengths of these jets are in the range of 10 to 100μm. *Reneker,D.H.; Yarin, A. L.; Fong, H.; Koombhongse, S., Journal of Applied Physics, 87, 4531, 2000 *Tchavdarov B.; Yarin, A. L.; Radev S., Journal of Fluid Mechanics; 253, 593,1993

  19. Finite element simulations of the bending of the IPMC sheet

    Science.gov (United States)

    Pugal, D.; Kasemägi, H.; Kim, K. J.; Kruusmaa, M.; Aabloo, A.

    2007-04-01

    This paper presents a electro-mechanical model of an IPMC sheet. The model is developed using Finite Element method. The physical bending of an IPMC sheet due to the drift of counter-ions (e.g Na+) and water in applied electric field are simulated. Our model establishes a cause-effect relationship between the charge imbalance of the counter-ions and the mechanical bending of the IPMC sheet. The model takes into account the mechanical properties of the Nafion polymer as well as the platinum coating. As the simulations are time dependent, a transient model is used and some additional parameters, such as damping coefficients, are included. In addition to electro-mechanical model, electrochemical reactions are introduced. Equations describing periodic adsorption and desorption of CO and OH on a platinum electrode of an IPMC muscle immersed into formaldehyde solution are coupled to mechanical properties of the proposed model. This permits us to simulate self-oscillatory behavious of an IPMC sheet. The simulation results are compared to experimental data.

  20. Torsional and Bending Vibration Measurement on Rotors Using Laser Technology

    Science.gov (United States)

    MILES, T. J.; LUCAS, M.; HALLIWELL, N. A.; ROTHBERG, S. J.

    1999-09-01

    Based on the principles of laser Doppler velocimetry, the laser torsional vibrometer (LTV) was developed for non-contact measurement of torsional oscillation of rotating shafts, offering significant advantages over conventional techniques. This paper describes comprehensive theory to account for the sensitivity of the LTV's measurements to shaft motion in all degrees of freedom. The optical geometry of the LTV offers inherent immunity to translational motion of the target shaft, either axial or radial. However, its measurements are sensitive to angular lateral vibration of the shaft. The significance of this sensitivity is compared with the instrument noise floor and typical torsional and lateral vibration levels. Optimum alignments of the instrument are then specified to ensure effective immunity to all lateral motion in typical applications. To overcome this problem more reliably, a new technique is proposed permitting unambiguous measurement of pure torsional vibration in situations where use of a single LTV demonstrates unacceptable sensitivity to angular lateral vibrations. Practical application of this technology is demonstrated with torsional vibration measurements from a diesel engine crankshaft. Simultaneously, previously unattained measurements of shaft bending vibration measurements are made. The first bending mode of the crankshaft was identified and its vibration amplitude and damping estimated. This application of laser vibrometry for non-contact measurements of shaft vibration represents a further step forward in the use of this technology for machinery diagnostics.