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Sample records for wire tension measurement

  1. A Laser Based Instrument for MWPC Wire Tension Measurement

    CERN Document Server

    Baldini, W; Evangelisti, F; Germani, S; Landi, L; Savrié, M; Graziani, G; Lenti, M; Lenzi, M; Passaleva, G; Carboni, G; De Capua, S; Kachtchouk, A

    2007-01-01

    A fast and simple method for the measurement of the mechanical tension of wires of Multi Wires Proportional Chambers (MWPCs) is described. The system is based on commercial components and does not require any electrical connection to the wires or electric or magnetic field. It has been developed for the quality control of MWPCs of the Muon Detector of the LHCb experiment in construction at CERN. The system allows a measurement of the wire tension with a precision better than 0.5% within 3-4 seconds per wire

  2. Development of a portable and fast wire tension measurement system for MWPC construction

    Science.gov (United States)

    Pan, Jing-Hui; Ma, Chang-Li; Gong, Xue-Yu; Sun, Zhi-Jia; Wang, Yan-Feng; Yin, Chen-Yan; Gong, Lei

    2016-09-01

    In a multi-wire proportional chamber detector (MWPC), the anode and signal wires must maintain suitable tension, which is very important for the detector’s stable and accurate performance. As a result, wire tension control and measurement is essential in MWPC construction. A high pressure 3He MWPC detector is to be used as the thermal neutron detector of the multi-functional reflectometer at China Spallation Neutron Source, and in the construction of the detector, we have developed a wire tension measurement system. This system is accurate, portable and time-saving. With it, the wire tension on an anode wire plane has been tested. The measurement results show that the wire tension control techniques used in detector manufacture are reliable. Supported by National Natural Science Foundation of China (A050506), State Key Laboratory of Particle Detection and Electronics and Key Laboratory of China Academy of Engineering Physics (Y490KF40HD)

  3. Development of a portable and fast wire tension measurement system for MWPC's construction

    OpenAIRE

    Pan, Jing-Hui; Ma, Chang-Li; Gong, Xue-Yu; Sun, Zhi-Jia; Wang, Yan-Feng; Yin, Chen-Yan; Gong, Lei

    2016-01-01

    In a multi-wire proportional chamber detector(MWPC), the anode and signal wires must maintain suitable tensions, which is very important for the detector's stable and perfect performance. As a result, wire tension control and measurement is essential in MWPC's construction. The thermal neutron detector of multi-functional reflectometer at China Spallation Neutron Source is designed using a high pressure $^{3}$He MWPC detector, and in the construction of the detector, we developed a wire tensi...

  4. Reduction in wire tension caused by wire clamping and wire tensioner removal: an experimental Ilizarov frame study.

    Science.gov (United States)

    La Russa, Valentina; Skallerud, Bjørn; Klaksvik, Jomar; Foss, Olav A

    2011-03-01

    The stability of an external ring fixator mainly depends on wire tension. Wire fixators should maintain the tension during both wire clamping to the ring and removal of the tensioner device. In the present study the loss in wire tension related to fixator clamping and wire tensioner removal using three different wire fixator designs was studied. The fixators were based on two different cannulated bolts and a washer. Effects from two different pretension levels in combination with three different bolt torque levels upon loss in wire tension were described. Emitted wire vibration frequency was used to assess the corresponding wire tension. Wire tension was determined after each wire fixator tightening and after the removal of the wire tensioner. Increased bolt torque led to a small decrease in tension for both pretension levels. A considerable higher tension loss was measured when removing the wire tensioner. In all cases, the combination of a new cannulated bolt and a washer maintained the highest tension.

  5. A Contact-Less 2-Dimensional Laser Sensor for 3-Dimensional Wire Position and Tension Measurements

    Science.gov (United States)

    Prall, Matthias; Hannen, Volker M.; Johren, Raphael; Ortjohann, Hans-Werner; Reinhardt, Martina; Weinheimer, Christian

    2010-04-01

    We have developed a contact-less two-dimensional laser sensor which combines position and tension measurements of wires with a diameter of order 0.2 mm. The sensor consists of commercially available laser pointers, lenses, color filters and photodiodes. In our application we have used this laser sensor in conjunction with an automated three-dimensional coordinate measuring machine (CMM). The device allows for a position measurement of wires in three dimensions with an accuracy of about 10 ¿m. At the same time the wire tension can be determined with an accuracy of 0.04 N. The device is operated at a distance of 150 mm from the wire. For each position measurement, the laser sensor is moved by the automated CMM into a plane, where the coordinates at which the wires intersect with this plane are determined. The position of the plane itself (the third coordinate) is given by the third axis of the CMM which is perpendicular to this plane. The precision of the device was determined using stainless steel wires with a diameter of 0.2 mm and a tension of 5 N. We use the sensor for quality assurance of the wire electrode modules for the KATRIN neutrino mass experiment. These modules are comprised of two layers of wires, which are 70 mm apart. In general, the device presented here is well suited for the measurement of any complex wire chamber geometry.

  6. Design and implementation of wire tension measurement system for MWPCs used in the STAR iTPC upgrade

    Science.gov (United States)

    Wang, Xu; Shen, Fuwang; Wang, Shuai; Feng, Cunfeng; Li, Changyu; Lu, Peng; Thomas, Jim; Xu, Qinghua; Zhu, Chengguang

    2017-07-01

    The STAR experiment at RHIC is planning to upgrade the Time Projection Chamber which lies at the heart of the detector. We have designed an instrument to measure the tension of the wires in the multi-wire proportional chambers (MWPCs) which will be used in the TPC upgrade. The wire tension measurement system causes the wires to vibrate and then it measures the fundamental frequency of the oscillation via a laser based optical platform. The platform can scan the entire wire plane, automatically, in a single run and obtain the wire tension on each wire with high precision. In this paper, the details about the measurement method and the system setup will be described. In addition, the test results for a prototype MWPC to be used in the STAR-iTPC upgrade will be presented.

  7. Evaluation of the accuracy of a veterinary dynamometric wire tensioner.

    Science.gov (United States)

    Gauthier, C M; McGilvray, K; Myrick, S; Duerr, F; Palmer, R

    2015-01-01

    The purpose of this study was to determine the accuracy of a commonly used veterinary wire tensioner. Wire tension was measured using a load cell after each of five tensioners were used to tension each of six wires to the 66, 84, and 118 mm ring settings in an adjustable custom testing fixture. Each tensioner then experienced simulated aging and testing was repeated. Percentage error was calculated for each ring size, before and after tensioner aging. Measured tension values were compared to manufacturer reported tension values for each ring size using a one-sample two-way t-test; p tension values were significantly lower for 66 mm and 84 mm rings and significantly higher for 118 mm rings, before and after simulated aging. Mean wire tension values did not significantly differ between individual wire tensioners. The tensioners tested achieved significantly different wire tension values than those reported by the manufacturer. This discrepancy could lead to under-tensioning and allowing excessive movement at a fracture site or over-tensioning, leading to wire breakage. We recommend tensioning wires at least to the recommended line on the device for 66 mm and 84 mm rings and at most to the recommended line for 118 mm rings. Further studies are needed to evaluate other veterinary wire tensioners and to develop a calibration method for these devices in practice.

  8. Flicking-wire drag tensioner

    Science.gov (United States)

    Dassele, M. A.; Fairall, H.

    1978-01-01

    Wire-drag system improves wire profile and applies consistent drag to wire. Wire drag is continuously adjustable from zero drag to tensile strength of wire. No-sag wire drag is easier to thread than former system and requires minimal downtime for cleaning and maintenance.

  9. Percutaneous tension band wiring for patellar fractures.

    Science.gov (United States)

    Rathi, Akhilesh; Swamy, M K S; Prasantha, I; Consul, Ashu; Bansal, Abhishek; Bahl, Vibhu

    2012-08-01

    To evaluate outcome of percutaneous tension band wiring for transverse fractures of the patella. 16 men and 7 women aged 27 to 65 (mean, 40) years underwent percutaneous tension band wiring for transverse fractures of the patella with a displacement of >3 mm. Pain, operating time, mobility, functional score, and complications were evaluated. 20 patients underwent successful percutaneous tension band wiring. The remaining 3 patients in whom closed reduction failed underwent open reduction and tension band wiring. The mean operating time was 46 (range, 28-62) minutes. The mean follow-up period was 20 (range, 15-30) months. At the latest follow-up, all patients had regained full extension. The objective score was excellent in 20 patients and good in 3, whereas the subjective score was excellent in 17, good in 5, and fair in one. All patients had radiological union at week 8. One patient had patellofemoral arthritis (secondary to a postoperative articular step). Two patients developed superficial infections, which resolved after antibiotic therapy. Mean thigh muscle wasting was 0.7 (range, 0.4-1) cm. Three patients encountered hardware problems (impingement/irritation of the skin over the knee) necessitating implant removal. Percutaneous tension band wiring is a viable option for transverse fractures of the patella.

  10. Tension band wiring fi xation is associated with good functional ...

    African Journals Online (AJOL)

    Background: Tension band wiring (TBW) is a widely accepted technique for olecranon fractures. Various investigators have reported a significant rate of complications especially hardware prominence. The purpose of this study was to determine the clinical and radiological outcome after tension band wiring of olecranon ...

  11. Mechanical evaluation of pin and tension-band wire factors in an olecranon osteotomy model.

    Science.gov (United States)

    Neat, Benjamin C; Kowaleski, Michael P; Litsky, Alan S; Boudrieau, Randy J

    2006-06-01

    To evaluate the effect of altering pin and wire diameter, wire position and configuration, and osteotomy angle on applied load and absorbed strain energy in a pin and tension-band wire (PTBW) fixation model. In vitro mechanical study. Delrin models (n=96). PTBW was applied to Delrin olecranon osteotomy models. A control configuration was defined and then altered, 1 variable (wire diameter, pin diameter, wire-hole position, wire configuration, osteotomy angle) at a time, to create 11 test configurations. Tensile force was applied and displacement at the caudal aspect of the osteotomy was measured. Fixation strength, in terms of tensile load and strain energy, was compared between control and each test configuration at 4 osteotomy displacements. Models with larger wire, pins, or combined figure-of-eight/lateral wires were stronger than control, whereas those with smaller wire, pins, or a solitary lateral wire were weaker. The superior strength of the larger wire was apparent for all assessed osteotomy displacement. PTBW fixation strength increases as implant diameter is increased, with wire diameter having greatest effect. Lateral wire configuration is weaker than figure-of-eight, but can be added to figure-of-eight configuration to increase strength. Wire-hole position and osteotomy angle have little effect on PTBW strength. Wire diameter is the key determinant of PTBW strength, whereas pin diameter is somewhat less critical. Wire passage through an additional hole proximally provides equivalent strength and may avoid soft-tissue entrapment and subsequent loosening.

  12. The effects of wire diameter and an additional lateral wire on pin and tension-band fixation subjected to cyclic loads.

    Science.gov (United States)

    Neat, B; Kowaleski, M P; Litsky, A S; Boudrieau, R J

    2006-01-01

    Despite reports of frequent complications, pin and tension- band wire remains the most common repair of simple olecranon fractures and osteotomies. A recent mechanical study found wire diameter to be the key determinant of pin and tension-band construct strength; models with 1.25-mm wire were much stronger than those with standard 1.0-mm wire exposed to single loads to failure. Additionally, fixation strength was also increased when a lateral wire was used in combination with a standard figure-of-eight wire. The purpose of the present study was to assess any advantages provided by 1.25-mm wire or an additional lateral wire over 1.0-mm wire for pin and tension-band fixation subjected to cyclic loading. Pin and tension-band fixation was applied to plastic olecranon osteotomy models with three wire configurations: 1.0-mm figure-of-eight, 1.25-mm figure-of-eight, and combined 1.0-mm figure-of-eight and lateral. Cyclic load was applied while caudal osteotomy displacement was measured with an extensometer. The three groups were compared in terms of cycles to failure, mean minimum displacement, mean maximum displacement, and mean displacement per cycle. Models with an additional lateral wire survived significantly more cycles than those with a solitary 1.0-mm figure-of-eight wire, although caudal osteotomy displacements were not significantly different. Conversely, models with 1.25-mm wire allowed significantly smaller minimum and maximum displacements than those with 1.0-mm wire, but did not survive significantly more cycles. It therefore appears that clinical use of 1.25-mm wire may improve stability, while use of an additional lateral wire may improve durability.

  13. Biomechanical analysis of tension band wiring (TBW) of transverse fractures of patella.

    Science.gov (United States)

    Ali, Mohammed; Kuiper, Jan; John, Joby

    2016-10-01

    Tension band wiring is commonly used for fixation of simple transverse fractures. The popular configuration is parallel Kirschner wires (K-wires) and a stainless steel wire loop placed in a vertically oriented figure-of-8. We used a wooden model of a patella with a midway transverse fracture and compared four different types of fixation. The first construct had a vertical figure-of-8 with one twist of wire. The second contained a vertical figure-of-8 with two twists of wire. The third was a vertical figure-of-8 with two twists of wire placed at adjacent corners while the last one had a horizontal figure-of-8 with two twists of wire placed at adjacent corners. Interfragmentary compression at the point of wire breakage was measured for each construct as well as permanent displacement on cyclic loading. Placement of the figure-of-eight in a horizontal orientation with two wire twists at the corner improved interfragmentary compression by 63% (p fracture displacement after cyclic loading was 67% lower with horizontal figure- of-eight constructs (p < 0.05; t test). Placing wire twists at the corner and a horizontal placement of figure-of-8 improves stability of the construct.

  14. Command Wire Sensor Measurements

    Science.gov (United States)

    2012-09-01

    NPS anechoic chamber is located in Spanagel Hall, Room 604. Although the chamber was built for instruction purposes only, it can be used for research...thesis is to investigate the wire scattering behavior and clutter characteristics through measurements performed in the NPS anechoic chamber. The...research has successfully resolved the various multipath components within the anechoic chamber. The transmit-receive coupling between the antennas was

  15. The accuracy of fine wire tensioners: a comparison of five tensioners used in hybrid and ring external fixation.

    Science.gov (United States)

    Roberts, Craig S; Antoci, Valentin; Antoci, Valentin; Voor, Michael J

    2004-03-01

    To compare the accuracy of 5 commonly available fine wire tensioners used in hybrid and ring external fixation. A laboratory investigation. The testing of 5 commonly available tensioners was performed with a servohydraulic test frame (MTS Bionix 858, Minneapolis, MN). The real wire tension data of each tensioner provided by the MTS were compared with corresponding nominal values. The percent error for each tensioner was calculated. Clinical ease of usage of the wire tensioners was also evaluated. The EBI tensioner was the most accurate (-0.17% to 0.09% error). The Smith and Nephew tensioner had a -13.97% to -8.61% error, the How medica tensioner a -12.48% to -10.86% error, and the Synthes tensioner a -0.2% to 24.28% error. The DePuyACE tensioner was the least accurate, with errors ranging from -36.76% to -30.92%. The Howmedica tensioner was the easiest to use, followed by the Smith and Nephew tensioner, the DePuyACE tensioner, the Synthes tensioner, and the EBI tensioner. Most commonly available tensioners tend to undertension. Future efforts should focus on the development of wire tensioners that combine accuracy and ease of usage.

  16. Assessment Results of Patellar Fracture Treatment after Tension Band Wiring

    Directory of Open Access Journals (Sweden)

    S. Abdolhossein Mehdinasab

    2013-04-01

    Full Text Available Background: To assess the results of patellar fracture treatment by tension band wiring. Materials and Methods: This retrospective study was performed to evaluate clinical and radiological results of patellar fracture during past 6 years.Results: Twenty four patients were participated in follow-up. Union was occurred in the mean time of 2.67±0.61 months. Falling down and direct trauma were the most common cause of fracture. Most common complications were thigh muscle atrophy and pin irritation. Excellent and good results in 87.5% and fair results in 12.5% of the patients were seen.Conclusion: Fixation of patellar fractures with tension band wiring was associated with a high rate of union.

  17. Measuring Surface Tension of a Flowing Soap Film

    Science.gov (United States)

    Sane, Aakash; Kim, Ildoo; Mandre, Shreyas

    2016-11-01

    It is well known that surface tension is sensitive to the presence of surfactants and many conventional methods exist to measure it. These techniques measure surface tension either by intruding into the system or by changing its geometry. Use of conventional methods in the case of a flowing soap film is not feasible because intruding the soap film changes surface tension due to Marangoni effect. We present a technique in which we measure the surface tension in situ of a flowing soap film without intruding into the film. A flowing soap film is created by letting soap solution drip between two wires. The interaction of the soap film with the wires causes the wires to deflect which can be measured. Surface tension is calculated using a relation between curvature of the wires and the surface tension. Our measurements indicate that the surface tension of the flowing soap film for our setup is around 0.05 N/m. The nature of this technique makes it favorable for measuring surface tension of flowing soap films whose properties change on intrusion.

  18. Most Wired 2006: measuring value.

    Science.gov (United States)

    Solovy, Alden

    2006-07-01

    As the Most Wired hospitals incorporate information technology into their strategic plans, they combine a"balanced scorecard"approach with classic business analytics to measure how well IT delivers on their goals. To find out which organizations made this year's 100 Most Wired list, as well as those named in other survey categories, go to the foldout section.

  19. K-wire position in tension-band wiring technique affects stability of wires and long-term outcome in surgical treatment of olecranon fractures.

    NARCIS (Netherlands)

    Linden, S.C. van der; Kampen, A. van; Jaarsma, R.L.

    2012-01-01

    BACKGROUND: Tension-band wiring (TBW) has been accepted as the treatment of choice for displaced olecranon fractures. The aim of this study was to examine the effect of K-wire position on instability of the K-wires in relation to local complications and radiological and clinical long-term outcome.

  20. Delayed migration of K-wire into popliteal fossa used for tension band wiring of patellar fracture

    Directory of Open Access Journals (Sweden)

    Meena Sanjay

    2013-06-01

    Full Text Available 【Abstract】Breakage of K-wires and stainless steel wires which are used for fracture fixation is not uncommon, but migration is rare. We report a case of migration of bro-ken K-wire used for patella tension band wiring to the popliteal fossa. The broken hardware was removed surgically. We would like to suggest that K-wire and wire fixation used for treatment of patellar fractures can migrate into the posterior compartment of the knee and cause clini-cal symptoms. Close clinical and radiological follow-up af-ter internal fixation to identify the presence of hardware breakage or movement and removal of wires once fracture has united can avert such complications. Key words: Patella; Fracture fixation, internal; Bone wires

  1. Biomechanical analysis of a transverse olecranon fracture model using tension band wiring.

    Science.gov (United States)

    Hammond, James; Ruland, Robert; Hogan, Christopher; Rose, David; Belkoff, Stephen

    2012-12-01

    To determine (1) the most distal site at which a tension band construct can maintain bony alignment during dynamic loading of a transverse, length-stable olecranon osteotomy; (2) the location of displacement during cyclical loading; and (3) the ultimate load to failure of the fixation. We divided 23 non-osteoporotic, fresh-frozen upper extremities into 4 groups. We created transverse osteotomies at 25% of the olecranon surface in group 1, 50% in group II, 75% in group III, and 100% in group IV. We used standard tension band wiring technique to stabilize each osteotomy. We mounted specimens on a biomechanical testing machine at 90° elbow flexion and subjected them to a 150-N sinusoidal load through the triceps tendon at 1 Hz for 500 cycles. An optical motion tracking system synchronized with the testing machine-measured displacement of the osteotomy in any plane. On completion of cycling, we loaded specimens at 1 mm/s until 2-mm displacement occurred. We analyzed data to determine the effect of the location of the osteotomy on load to failure and location of displacement. Of the 23 specimens, 21 survived the cycling process. The 2 specimens that failed were both in group II (50%). Excluding these 2 specimens, the average displacement at the 3 virtual points was less than 1.05 mm in all 4 osteotomy groups. There were no statistical differences between groups. Load to failure was 476, 361, 511, and 610 N for groups I to IV, respectively. Differences between groups were not statistically significant. The stability achieved with tension band wire fixation did not vary with the location of the osteotomy. Based on this biomechanical study, when it is properly executed, tension band wire fixation may be used effectively for transverse, length-stable fractures of the olecranon regardless of the amount of articular surface included on the proximal fragment. Published by Elsevier Inc.

  2. Developing Light Collection Enhancements and Wire Tensioning Methods for LArTPC Neutrino Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Spagliardi, Fabio [Univ. of Manchester (United Kingdom)

    2017-01-01

    Liquid argon Time Projection Chambers (LArTPCs) are becoming widely used as neutrino detectors because of their image-like event reconstruction which enables precision neutrino measurements. They primarily use ionisation charge to reconstruct neutrino events. It has been shown, however, that the scintillation light emitted by liquid argon could be exploited to improve their performance. As the neutrino measurements planned in the near future require large-scale experiments, their construction presents challenges in terms of both charge and light collection. In this dissertation we present solutions developed to improve the performance in both aspects of these detectors. We present a new wire tensioning measurement method that allows a remote measurement of the tension of the large number wires that constitute the TPC anode. We also discuss the development and installation of WLS-compound covered foils for the SBND neutrino detector at Fermilab, which is a technique proposed t o augment light collection in LArTPCs. This included preparing a SBND-like mesh cathode and testing it in the Run III of LArIAT, a test beam detector also located at Fermilab. Finally, we present a study aimed at understanding late scintillation light emitted by recombining positive argon ions using LArIAT data, which could affect large scale surface detectors.

  3. Factors affecting the outcomes of modified tension band wiring techniques in transverse patellar fractures.

    Science.gov (United States)

    Hsu, Kai-Lan; Chang, Wei-Lun; Yang, Chyun-Yu; Yeh, Ming-Long; Chang, Chih-Wei

    2017-12-01

    Modified tension band wiring has been widely used to treat transverse patellar fractures. However, few studies have evaluated the clinical outcomes using different methods of Kirschner wire bending, location of the tension band, and depths of Kirschner wires. Thus, we tried to clarify these factors according to our clinical outcomes. This retrospective cohort study recruited consecutive patients underwent surgical fixation for patellar fractures using modified tension band technique between January 2010 and December 2015. Different factors in this procedure, including the bending manner of the Kirschner wires, their depth, and location of the tension band with respect to the superior and inferior border of the patella were recorded and analysed. The primary outcome was early loss of fixation. The secondary outcomes were minor loss of reduction, implant breakage, deep infection, and the need for implant removal. This study included 170 patients with patellar fractures. Regarding the bending method, similar results were obtained with bilaterally or proximally bent Kirschner wires. Regarding length, the tension band was placed closely (within 25% of the patella length) in 124 patients and distantly in 46 patients. The rates of loss of reduction and implant breakage were significantly higher in the distantly placed tension bands. Regarding depth, 37 patellar fractures were fixed with the Kirschner wires at the superficial one third of the patellae while the K- wires at the middle layer of patella were used in the remaining 133 patellar fractures. A significantly higher rate of minor loss of reduction was obtained using the superficial Kirschner wires. The modified tension band technique for transverse patella fractures provides favourable clinical outcomes, with low failure (5%) and infection (2%) rates. Implant irritation is the major complication, and almost half of cases require implant removal. The location of the tension band with respect to the superior and

  4. A STUDY ON THE MANAGEMENT OF DISPLACED FRACTURES OF PATELLA USING MODIFIED TENSION BAND WIRING

    Directory of Open Access Journals (Sweden)

    Hari Babu

    2015-10-01

    Full Text Available INTRODUCTION: Patella is an important component of the extensor mechanism of the knee. A patella fracture constitutes 1% of all skeletal fractures resulting from either direct or indirect trauma. Any improper and inadequate treatment would inevitably lead to a disability which would be most perceptibly felt in a country like India, where squatting is important activity in daily life. The goal of treatment is to regain the continuity of the extensor mechanism and congruity of patellofemoral a rticulation so that the normal function of the knee can be restored. Several techniques have been described for internal fixation of fractures of patella. The ideal fixation for the fracture patella is that it should be strong enough to allow early mobiliz ation, reduce posttraumatic stiffness and perhaps help the healing of the articular surface . AIMS: To analyze the functional outcome of displaced transverse fractures of the patella treated by Modified Tension Band Wiring principle (Muller using A. Dutta & S. K. Gupta Scoring System. To extend the application of Modified Tension Band wiring for minimally comminuted fractures of patella and assesses the results. CONCLUSION : The present study shows that modified tension band wiring (Muller is an effective p rocedure in the management of displaced transverse patellar fractures, with excellent to good results. Minimally comminuted patellar fractures also yielded excellent to good results with Modified tension band wiring as an extended application. The results in the present study are comparable to other modifications of Tension Band Wiring principle. The surgery of Modified Tension Band Wiring gives rigid fixation and helps in early mobilization. Regular and scheduled post- operative physiotherapy plays an impor tant role in the functional outcome.

  5. [Separate vertical wiring combined with tension band and Kirschner-wire plus cerclage wire in the treatment of displaced inferior pole fractures of the patella].

    Science.gov (United States)

    Zhang, J; Jiang, X Y; Huang, X W

    2016-06-18

    To investigate the clinical efficacy and outcomes of two separate vertical wiring combined with tension band and Kirschner-wire plus cerclage wire in the treatment of displaced inferior pole fractures of the patella. From January 2013 to January 2015, 15 consecutive patients (mean age 54.5 years) with inferior pole fractures of the patella were retrospectively included in this study. All the patients underwent open reduction and internal fixation by separate vertical wiring combined with tension band and Kirschner-wire plus cerclage wire through longitudinal incision, 4.5 d (range: 3.1-5.9 d) after initial injury. A safety check for early knee range of motion was performed before wound closure. The complications including infection, nonunion, loss of fixation and any wire breakage or irritation from implant were recorded. Anteroposterior and lateral views of the knee joint obtained during the follow-up were used to assess bony union based on the time when the fracture line disappeared. At the time of the final outpatient follow up, functional evaluation of the knee joint was conducted by Bostman system. The follow-up time was 13.1 months (range: 12-19 months) after surgery on average, immediate motion without immobilization in all the cases was allowed and there was no case of reduction loss of the fracture and wire breakage. There was no case of irritation from the implant. At the final follow-up, the average range of motion (ROM) arc was 126.7° (range: 115°-140°), the average ROM lag versus contralateral healthy leg was 10.3° (range: 0°-35°). The mean Bostman score at the last follow-up was 28.9 (range: 27-30), and graded excellent in most cases. Two separate vertical wiring is an easy and effective method to reduce the displaced inferior pole fracture of patella. Augmentation of separate vertical wiring with tension band and Kirschner-wire plus cerclage wire in these patients provides enough strength to protected the early exercise of the knee joint and

  6. Tension band wiring in olecranon fractures: the myth of technical simplicity and osteosynthetical perfection.

    Science.gov (United States)

    Schneider, Marco M; Nowak, Tobias E; Bastian, Leonard; Katthagen, Jan C; Isenberg, Jörg; Rommens, Pol M; Müller, Lars P; Burkhart, Klaus J

    2014-04-01

    The tension band wiring (TBW) technique is a common treatment for the fixation of olecranon fractures with up to three fragments. The literature and surgeons describe TBW as an uncomplicated, always available and convenient operation producing excellent results. The purpose of this study was to determine whether TBW is more ambitious than believed or the procedure provides an increased level of tolerance concerning the surgical technique. This study reviewed 239 TBW cases in patients with olecranon fractures or osteotomies. We reviewed a total of 2,252 X-rays for ten operative imperfections: (1) nonparallel K-wires, (2) long K-wires, (3) K-wires extending radially outwards, (4) insufficient fixation of the proximal ends of the K-wires, (5) intramedullary K-wires, (6) perforation of the joint surface, (7) single wire knot, (8) jutting wire knot(s), (9) loose figure-of-eight configuration, and (10) incorrect repositioning. On average, there were 4.24 imperfections per intervention in the cases reviewed. A total of 1,014 of 2,390 possible imperfections were detected. The most frequent imperfections were insufficient fixation of the proximal ends of the K-wires (91% of all cases), the use of a single wire knot (78%) and nonparallel K-wires (72%). Mayo IIa (n = 188) was the most common fracture type. Our results and the number of complications described by the literature together support the conclusion that TBW is not as easy as surgeons and the literature suggest. Although bone healing and the functional results of TBW are excellent in most cases, the challenges associated with this operation are underestimated. IV, treatment study.

  7. Migration of a Kirschner wire to the dorsolateral side of the foot following osteosynthesis of a patella fracture with tension band wiring: a case report.

    Science.gov (United States)

    Aydın, Ekrem; Dülgeroğlu, Turan Cihan; Metineren, Hasan

    2016-02-24

    Patella fractures represent 1 % of all musculoskeletal system fractures. Fixation of patellar fractures using open reduction and tension band wiring is a commonly used and successful surgical fixation method. A 28-year-old male patient from Turkey presented to our clinic with complaints of palpable foreign bodies under the skin on the dorsolateral side of his right foot. Except for the palpable and moving body of about 6 cm length under the skin in his foot, he had no functional complaints. On X-ray, a Kirschner wire was visible in front of the lateral malleolus on the dorsolateral side of his right foot. In addition, there was a cerclage wire from the tension band fixation of his patella in the ipsilateral knee. The Kirschner wire was removed surgically. Despite the use of different fixation materials for the surgical treatment of patellar fractures, tension band wiring is still a commonly used technique. We recommend that after fixation of a patellar fracture using the tension band wiring technique, the ends of the Kirschner wires be bent and the wires then removed in the early phase after patellar union to prevent Kirschner wire migration.

  8. Ratcheting of 316L stainless steel thin wire under tension-torsion loading

    Directory of Open Access Journals (Sweden)

    Sichao Fu

    2016-10-01

    Full Text Available A series of cyclic tension-torsion tests under symmetric shear strain and asymmetric axial stress control in various loading paths are conducted on 100 μm-diameter 316L steel wires applying a micro tensiontorsion fatigue testing apparatus. The ratcheting strain of the thin wire increases with increasing axial mean stress and decreases in a sequence of linear, rhombic and circular paths. The macro-scale based cyclic plastic constitutive models with kinematic hardening rules of the Ohno-Wang (OW and the Chen-Jiao-Kim (C-J-K are evaluated for the thin wire. Comparing with the O-W, the C-J-K predicts more accurately under high axial stress. While the loading path effects on ratcheting for wire specimens are basically simulated, the macro-based models tend to under-estimate the effect of phase difference between axial and torsional loadings and the ratcheting evolution in the initial 50 cycles

  9. Surface tension measurements with a smartphone

    Science.gov (United States)

    Goy, Nicolas-Alexandre; Denis, Zakari; Lavaud, Maxime; Grolleau, Adrian; Dufour, Nicolas; Deblais, Antoine; Delabre, Ulysse

    2017-11-01

    Smartphones are increasingly used in higher education and at university in mechanics, acoustics, and even thermodynamics as they offer a unique way to do simple science experiments. In this article, we show how smartphones can be used in fluid mechanics to measure surface tension of various liquids, which could help students understand the concept of surface tension through simple experiments.

  10. Horizontal versus vertical orientation of the loop for tension band wiring of transverse patella fractures.

    Science.gov (United States)

    Lee, Sang Ki; Hwang, Yoon Sub; Choy, Won Sik

    2014-03-01

    Conventional operative treatments of patella fractures are frequently associated with implant failure or displacement. Recent biomechanical studies showed that the orientation of the wire loop and the site of the wire twist can affect the fixation strength. The purpose of this study was to compare the clinical outcome of the tension band technique with loops in different orientations and different knot positions. For this retrospective study, 72 patella fractures (71 patients) were fixed with figure-of-eight configurations in combination with 2 K-wires. Patients were divided into 3 groups according to the orientation of tension band construct. A total of 40 patella fractures were placed with figure-of-eight configurations in a vertical orientation either with 1 wire twist (group 1; 16 patella fractures) or with 2 wire twists at the adjacent corners (group 2; 24 patella fractures). Thirty-two patella fractures were placed with figure-of-eight configurations in a horizontal orientation with 2 wire twists at the adjacent corners (group 3). Range of motion, complication rates, and knee scoring scales (Hospital for Special Surgery and Lysholm) were assessed during serial follow-up. Satisfactory reductions were achieved in all groups, but functional results in the early stage were different. Group 3 had better Hospital for Special Surgery and Lysholm scores at 3 months postoperatively; however, at 6 months and 1 year postoperatively, all groups had similar scores. At the 1-year follow-up, all groups achieved acceptable flexion and range of motion. The overall complication rate was lower in the horizontal group (12.5%). Placing the figure-of-eight tension band construct in a horizontal orientation can provide functional benefits in the early stage after patella fractures. Copyright 2014, SLACK Incorporated.

  11. Simplified Calculation of Maximum Wire Tension in case of Short Circuit

    Directory of Open Access Journals (Sweden)

    I. I. Sergey

    2007-01-01

    Full Text Available Modified method for a simplified calculation of a maximum wire tension in case of a short circuit. This method makes it possible to take into account a real trajectory of their movement and elements of a switch-gear. An accuracy evaluation of the simplified calculation has been done with the help of a calculative experiment using a BusEf computer software. A correction factor has been obtained to take into account an influence of insulator strings on a tension value.

  12. A CLINICAL STUDY OF SURGICAL MANAGEMENT OF FRACTURE PATELLA WITH MODIFIED TENSION BAND WIRING

    Directory of Open Access Journals (Sweden)

    Yerakula Ramana

    2017-08-01

    Full Text Available BACKGROUND Fractures of the patella are common and constitute almost 1% of all skeletal injuries. The patella is important for the extension of the knee joint. Several methods of internally fixing the fractured patella have been advocated. This study is directed towards the clinical evaluation of the modified tension band wiring technique for the fractured patella. MATERIALS AND METHODS The present study consists of 15 cases with fracture patella treated with modified tension band wiring during the period from October 2014 to October 2016 at govt. general hospital, Kurnool. RESULTS All cases were operated using a midline anterior vertical skin incision, 80% had excellent results, with normal squatting, gradeV quadriceps power and complete range of movement at knee joint.20% of cases had difficulty in squatting, grade-IV quadriceps power and limitation of flexion. Minimal quadriceps wasting seen in 20% of cases. CONCLUSION From the analysis

  13. Biomechanical comparison of a new staple technique with tension band wiring for transverse patella fractures.

    Science.gov (United States)

    Schnabel, Bernd; Scharf, Martin; Schwieger, Karsten; Windolf, Markus; Pol, Bas van der; Braunstein, Volker; Appelt, Andreas

    2009-12-01

    The tension band wiring technique is the most common method of transverse patella fracture fixation. Since post-operative instabilities have been reported for this technique, alternative osteosynthesis solutions are of interest. We investigated the biomechanical behaviour of a new staple technique for treatment of transverse patella fractures in a cadaveric model. Eight human cadaveric knees with femur and tibia including soft tissue were used. A transverse osteotomy of the patella was created. Each specimen was fixed consecutively with tension band wiring and two Nitinol compression staples. Testing was performed by pull on the quadriceps tendon between a 90 degrees flexed position and full knee extension for up to 5,000 cycles. At 1,000 cycles, fracture site displacements in flexion and extension were significantly smaller for the staple group at the ventral aspect of the patella as compared to the tension band wiring group. With a failure criterion of 2mm fracture site displacement, cycles until failure were significantly smaller for the staple group. This study provides evidence based on a cadaveric model that compression staples have a promising potential to treat transverse patella fractures.

  14. Open reduction and internal fixation of displaced patella inferior pole fractures with anterior tension band wiring through cannulated screws.

    Science.gov (United States)

    Chang, Shi-Min; Ji, Xiang-Ling

    2011-06-01

    To present the treatment outcome for patients with displaced inferior pole patella fractures treated with anterior tension band wiring through cannulated screws. Case series. Academic Level I trauma center. During a 2-year period between January 2007 and December 2008, 10 consecutive patients (mean age, 59.8 years) with distal pole fractures of the patella (Orthopaedic Trauma Association 45.A.1) were prospectively enrolled in this study. All 10 patients underwent vertical skin exposure, fracture open reduction, and internal fixation by anterior tension band wiring through 4.0-mm cannulated screws. The range of motion, loss of fracture reduction, implant migration, material failure, soft tissue irritation, and Bostman score and Short Musculoskeletal Functional Assessment dysfunction score were primary outcome measures. There were three single-fragment fractures and seven comminuted fractures. With 1-year follow-up, all fractures healed clinically in an average of 8 weeks and radiographically on average by 12 weeks. The average range of knee motion arc was 122.5° (range, 95°-140°). Five patients have an average flexion lag of 17° (range, 10°-30°). No patient had loss of fracture reduction, implant migration, material failure, or soft tissue irritation. The average Bostman score was 28.7 out of 30 (range, 27-30), and average Short Musculoskeletal Functional Assessment dysfunction score was 24.1 out of 100 (range, 15-39). All 10 patients stated they were highly satisfied. Anterior tension band wiring through cannulated screws for displaced inferior pole patella fractures is a safe, simple, and reliable alternative treatment with minimal soft tissue irritation. Good functional results and recovery can be expected.

  15. [Surgical treatment of acromioclavicular dislocation: Tension band wiring versus hook plate].

    Science.gov (United States)

    Tuček, M; Chochola, A; Vaněček, V; Bušková, K

    2015-10-01

    The aim of the prospective randomized study was to compare tension wire cerclage and hook plate in the treatment of AC dislocation, primarily from the viewpoint of functional and radiological results. The cohort comprised 80 patients with acute acromioclavicular (AC) dislocation of types 3, 4 and 5 of Rockwood classification. The diagnosis was based on the clinical (disfiguration and instability) and radiographic examination (AP and stress radiograph). Forty patients were treated with tension band wiring (TBW) and another 40 with a hook plate (HP). Evaluation was performed during one year after the surgery based on radiographs and the Constant score. The mean Constant score 3 months after the surgery was 84 points for TBW and 88 points for HP. One year after the surgery, the result was the same in both groups: 93 points. In HP group the score increased from 56 to 78 points between 2 and 4 weeks from the surgery. In 71 cases the postoperative position of the AC joint and implant was assessed as correct. Malposition of Kirschner wires was recorded in 6 cases and horizontal widening of the AC joint in 3 cases. Redislocation of up to 50100% of the width of acromion was shown by radiograph in 4 TBW patients (10%) and in 5 HP patients (13%). A visible osteolysis of the distal surface of acromion was found in 83% of patients with HP. Complications were recorded in 30% of TBW patients and in 5% of HP patients. Based on radiological and clinical results assessed 3 months and 1 year after the surger, the hook plate and tension band wiring are comparable treatment methods for AC dislocation. The hook plate is associated with a lower complication rate and allows earlier full weight bearing and mobility than tension wire cerclage. In TBW we recommend to remove the implant after 8 weeks; 6 weeks are in our view too short a period for the healing of soft tissues. In HP it is suitable to remove the hardware by 3 months due to potential subacromial irritation and pressure

  16. Fixation of Comminuted Patellar Fracture with Combined Cerclage and Tension Band Wiring Technique

    Directory of Open Access Journals (Sweden)

    T K Ong

    2008-11-01

    Full Text Available In comminuted patellar fractures, a combination of cerclage wiring and tension band fixation is said to provide good mechanical stability. This is a retrospective review of four patients treated with this method. All fractures described herein were classified as 45-C3 (based on Orthopaedic Trauma Association classification and were fixed with a 1.25mm cerclage wire and tension band wire proximally looped through the quadriceps tendon and distally through the patellar ligament in a figure-of-eight configuration. The average follow-up period was 10 months. The Activity of Daily Living Scale (ADLS of the Knee Outcome Survey was used to assess symptoms and functional capability of the knee. In all the cases, fracture union was achieved at an average of 11 weeks. The average ADLS score was good (92.5 %. Full range of knee motion was achieved by end of the third postoperative month. None of the patients had complications, such as infection and implant failure.

  17. Laser wire emittance measurement line AT CLIC

    CERN Document Server

    Garcia, H; Blair, G A; Aumeyr, T; Schulte, D; Stulle, F

    2011-01-01

    A precise measurement of the transverse beam size and beam emittances upstream of the final focus is essential for ensuring the full luminosity at future linear colliders. A scheme for the emittance measurements at the RTML line of the CLIC using laser-wire beam profile monitors is described. A lattice of the measurement line is discussed and results of simulations of statistical errors and of their impact on the accuracy of the emittance reconstruction are given. Laser wire systems suitable for CLIC and their main characteristics are discussed.

  18. Internal Fixation of Transverse Patella Fractures Using Cannulated Cancellous Screws with Anterior Tension Band Wiring

    Directory of Open Access Journals (Sweden)

    Khan I

    2016-07-01

    Full Text Available Aims: To evaluate the effectiveness and safety of anterior tension band wiring technique using two cannulated cancellous screws in patients with transverse (AO34-C1 or transverse with mildly comminuted (AO34-C2 patellar fractures. Materials and Methods: This is a prospective study of 25 patients with transverse fracture or transverse fracture with mildly comminuted patella fractures. All the patients were treated with open reduction and internal fixation using two parallel cannulated screws and 18G stainless steel wire as per the tension band principle. Results: There were eighteen males (72% and seven females (28%. The age group ranged from 24 to 58 years, with mean age of 38 years. The most common mode of injury was fall (72% followed by road traffic accident (20% and violent quadriceps contraction (8%. Transverse fracture was present in 60% and transverse fracture with mild comminution in 40% of patients. Mean time to achieve union was 10.7 weeks (range 8-12 weeks. Mean ROM at three months was 113.8 degree (90-130 and at final follow up this improved to 125.4 degrees (range 100-140. There was one case of knee stiffness and no case of implant failure was observed. Patients were evaluated using Bostman scoring, the mean score at three months being 26.04 which improved to 27.36 at the end of final follow up at one year. Conclusion: Cannulated cancellous screws with anterior tension band wiring is a safe, reliable and reproducible method in management of transverse patellar fractures, with less chances of implant failure and soft tissue irritation.

  19. [Capitolunate arthrodesis with tension band wire in wrist arthritis: twenty cases with four year follow-up].

    Science.gov (United States)

    Durand, A; Harisboure, A; Nurbel, B; Lawane, M; Grenier de Cardenal, D; Giraud, B; Kassouma, J; Dehoux, E

    2007-02-01

    Treatment of degenerative osteoarthritis of the wrist is aimed at preserving wrist motion and force while reducing pain. Limitation of the degenerative processes to certain joints raises the possibility of intracarpal arthrodesis, e.g. capitolunate arthrodesis. We present results of this procedure with a tension band wire in patients with arthritic degenerative disease of the wrist. The series included 20 patients reviewed at mean 47 months. Mean age was 53.5 years. Pain was the main complaint. Wrist force and motion were decreased in all patients. All patients presented osteoarthritic disease of the wrist with preservation of the radiolunate space. The operation consisted in total scaphoidectomy and capitolunate arthrodesis maintained with a tension band wire. Force, pain (Mayo clinic score) and force (Jamar dynamometer) were recorded. The Cooney function score was determined and six patients completed the French Dash questionnaire. Radiolunate and capitolunate angles were noted as well as the index of carpal height measured preoperatively and at last follow-up. Nineteen of the 20 arthrodeses fused. A revision graft was successful for the one nonunion. Pain was the only clinical factor which improved significantly (pwrist with a preserved radiolunate space. We prefer this procedure to four-way arthrodesis because useful motion and wrist force are preserved with constant and effective significant pain relief.

  20. Surface Tension Measurements with a Smartphone

    Science.gov (United States)

    Goy, Nicolas-Alexandre; Denis, Zakari; Lavaud, Maxime; Grolleau, Adrian; Dufour, Nicolas; Deblais, Antoine; Delabre, Ulysse

    2017-01-01

    Smartphones are increasingly used in higher education and at university in mechanics, acoustics, and even thermodynamics as they offer a unique way to do simple science experiments. In this article, we show how smartphones can be used in fluid mechanics to measure surface tension of various liquids, which could help students understand the concept…

  1. EVALUATION OF THE EFFICIENCY OF THE DEVICE FOR LIMITING TENSION OF THE WIRE IN A SHORT CIRCUIT

    Directory of Open Access Journals (Sweden)

    I. I. Sergey

    2017-01-01

    Full Text Available The intensity of the electrodynamic action of currents of a short circuit on the flexible conductors of overhead lines depends on the magnitude of currents of short-circuit. The commis sioning of new capacities is inevitably accompanied by an increase in short circuit currents in the nodes of the grid, so the need to limit peaks of tension arising in a short-circuit can acquire a special relevance at a certain stage of development of the power system. At short circuit currents over 40 kA the mechanical force and displacement of the wires can have a decisive influence on the structural performance of flexible bus as of single wires as well as of split phases. In this regard there is a need for the development and use of new structural elements enhancing electrodynamic stability of flexible busbars of outdoor switchgear. One such element is a tension damper. The damper is installed between the portal and the insulator string and limits the transmission of undesirable forces on the portals in a short circuit. The numerical method of calculation of dynamics of flexible wires of switchgear and overhead lines in a short-circuit taking into account influence of a tension damper has been developed. This method was used for modification of the computer program of calculation of electrodynamic stability. With the aid of the computer program it was demonstrated that the installation of the tension damper makes it possible to cut off peaks of the tension of wire in a short circuit at the initial stage of movement of the conductors. However, in spans of a great length after the actuation of the damper the occurrence of new bursts of tension is possible due to the sudden stop of the wire

  2. Magnetic measurement with coils and wires

    CERN Document Server

    Walckiers, L

    2010-01-01

    Accelerator magnets steer particle beams according to the field integrated along the trajectory over the magnet length. Purpose-wound coils measure these relevant parameters with high precision and complement efficiently point-like measurements performed with Hall plates or NMR probes. The rotating coil method gives a complete two-dimensional description of the magnetic field in a series of normal and skew multipoles. The more recent single stretched wire is a reference instrument to measure field integrals and to find the magnetic axis.

  3. Fixation of patella fractures with a minimally invasive tensioned wire method: compressive external fixation.

    Science.gov (United States)

    Wardak, Mohammed Ismail; Siawash, Abdul Razaqu; Hayda, Roman

    2012-05-01

    Current fixation methods of patella fractures are associated with hardware prominence, infection, and failure of fixation. These complications necessitate repeat surgical treatment, increase costs, and limit function. We investigated whether a novel device can effectively treat patella fractures with few complications. A consecutive series of patients with displaced patella fractures with transverse and select other patterns were treated with the technique of compressive external fixation (CEF), a device based on an external tensioned wire construct. Patients were allowed unrestricted motion and weight bearing postoperatively. Patient outcomes were evaluated retrospectively. Eighty-four fractures (26 open) were treated with CEF with 23 performed percutaneously. All of the fractures attained union. The device was removed in the office at 6 weeks. Sixty-one patients regained excellent motion with a mean Insall knee score of 97 points, at an average follow-up of 4 years. Minor complications presented in 11% of patients but did not affect the overall outcome. Complications included minor wire irritation in 14 patients and one case of poor knee motion in a patient presenting with fibroankylosis of the joint. Treatment using the CEF technique is a safe and effective method of treatment of patella fractures with advantages over traditional forms of fixation particularly in cases with a poor soft tissue envelope, salvage situations, and in locations with limited resources. It allows for rapid recovery with minimal complications and no secondary surgery. Its use should be considered in the treatment of these injuries. V, therapeutic study.

  4. Surface and interfacial tension measurement, theory, and applications

    CERN Document Server

    Hartland, Stanley

    2004-01-01

    This edited volume offers complete coverage of the latest theoretical, experimental, and computer-based data as summarized by leading international researchers. It promotes full understanding of the physical phenomena and mechanisms at work in surface and interfacial tensions and gradients, their direct impact on interface shape and movement, and their significance to numerous applications. Assessing methods for the accurate measurement of surface tension, interfacial tension, and contact angles, Surface and Interfacial Tension presents modern simulations of complex interfacial motions, such a

  5. 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...... in drawing of stainless steel showing the influence of varying process conditions and the performance of different lubricants....

  6. Cavity Mode Related Wire Breaking of the SPS Wire Scanners and Loss Measurements of Wire Materials

    CERN Document Server

    Caspers, Friedhelm; Jensen, E; Koopman, J; Malo, J F; Roncarolo, F

    2003-01-01

    During the SPS high intensity run 2002 with LHC type beam, the breaking of several of the carbon wires in the wire scanners has been observed in their parking position. The observation of large changes in the wire resistivity and thermionic electron emission clearly indicated strong RF heating that was depending on the bunch length. A subsequent analysis in the laboratory, simulating the beam by two probe antennas or by a powered stretched wire, showed two main problems: i) the housing of the wire scanner acts as a cavity with a mode spectrum starting around 350 MHz and high impedance values around 700 MHz; ii) the carbon wire used so far appears to be an excellent RF absorber and thus dissipates a significant part of the beam-induced power. Different wire materials are compared with the classical cavity mode technique for the determination of the complex permittivity in the range of 2-4 GHz. As a resonator a rectangular TE_01n type device is utilized.

  7. Cavity mode related wire breaking of the SPS Wire Scanners and loss measurements of wire materials

    CERN Document Server

    Roncarolo, Federico

    2003-01-01

    During the SPS high intensity run 2002 with LHC type beam, the breaking of several of the carbon wires in the wire scanners has been observed in their parking position. The observation of large changes in the wire resistivity and thermionic electron emission clearly indicated strong RF heating that was depending on the bunch length. A subsequent analysis in the laboratory, simulating the beam by two probe antennas or by a powered stretched wire, showed two main problems: i) the housing of the wire scanner acts as a cavity with a mode spectrum starting around 350MHz and high impedance values around 700 MHz; ii) the carbon wire used so far appears to be an excellent RF absorber and thus dissipates a significant part of the beam-induced power. Different wire materials are compared with the classical cavity mode technique for the determination of the complex permittivity in the range of 2-4 GHz. As a resonator a rectangular TE01n type device is utilized.

  8. Surface tension measurement from the indentation of clamped thin films.

    Science.gov (United States)

    Xu, Xuejuan; Jagota, Anand; Paretkar, Dadhichi; Hui, Chung-Yuen

    2016-06-21

    We developed an indentation technique to measure the surface tension of relatively stiff solids. In the proposed method, a suspended thin solid film is indented by a rigid sphere and its deflection is measured by optical interferometry. The film deflection is jointly resisted by surface tension, elasticity and residual stress. Using a version of nonlinear von Karman plate theory that includes surface tension, we are able to separate the contribution of elasticity to the total tension in the film. Surface tension is determined by extrapolating the sum of surface tension and residual stress to zero film thickness. We measured the surface tension of polydimethylsiloxane (PDMS) using this technique and obtained a value of 19.5 ± 3.6 mN m(-1), consistent with the surface energy of PDMS reported in the literature.

  9. Surface Tension Measurements of Chemically Modified Oleochemical

    Science.gov (United States)

    Surface tension is an important physical property of a substance, which plays a part in a variety of physical phenomenon relevant to many industrial processes. For example, the efficiency of the atomization of a fuel has been shown to be effected dramatically by surface tension and viscosity. Beca...

  10. Intramedullary Pinning with Tension-Band Wiring for Surgical Neck Fractures Of the Proximal Humerus in Elderly Patients

    Directory of Open Access Journals (Sweden)

    Cheng-Chang Lu

    2004-11-01

    Full Text Available Most proximal humeral fractures in the elderly population are related to osteoporosis. Several methods have been proposed to treat surgical neck fractures of the proximal humerus in elderly people. This study investigates a new method of intramedullary pinning with tension-band wiring. From June 1998 to March 2001, 10 female patients with a mean age of 73.0 years and displaced two- or three-part surgical neck fractures of the proximal humerus were studied. Two intramedullary pins were used with tension-band wiring via a deltopectoral approach with minimum dissection. The mean follow-up was 20.6 months. Final outcome was evaluated using the constant score, visual analog scale (VAS score, questionnaire, and an outcome assessment form. The outcome was excellent in four patients, good in five, and fair in one. The mean Constant score was 80.8 and the VAS score was 83.0. There was no nonunion, avascular necrosis, deep infection, or pin migration. No patient needed further revision open reduction with internal fixation or prosthesis replacement. We therefore concluded that intramedullary pinning with tension-band wiring is a safe, reliable method, with few complications, for treating surgical neck fractures of the proximal humerus in elderly patients.

  11. Measuring the surface tension of soap bubbles

    Science.gov (United States)

    Sorensen, Carl D.

    1992-01-01

    The objectives are for students to gain an understanding of surface tension, to see that pressure inside a small bubble is larger than that inside a large bubble. These concepts can be used to explain the behavior of liquid foams as well as precipitate coarsening and grain growth. Equipment, supplies, and procedures are explained.

  12. Biomechanical cadaver testing of a fixed-angle plate in comparison to tension wiring and screw fixation in transverse patella fractures.

    Science.gov (United States)

    Thelen, Simon; Schneppendahl, Johannes; Jopen, Eva; Eichler, Christian; Koebke, Jürgen; Schönau, Eckhard; Hakimi, Mohssen; Windolf, Joachim; Wild, Michael

    2012-08-01

    Operative treatment of patella fractures is frequently associated with implant failure and secondary dislocation which can be attributed to the employed hardware. Therefore, a 2.7 mm fixed-angle plate designed for the treatment of patella fractures was tested biomechanically against the currently preferred methods of fixation. It was hypothesized that under simulated cyclic loading fixed-angle plating would be superior to modified anterior tension wiring or cannulated lag screws with anterior tension wiring. Eighteen human cadaver knees, matched by bone mineral density and age, were divided into three groups of six. After setting a transverse patella fracture each group received one of the osteosyntheses mentioned above. Repetitive testing over 100 cycles was performed at non-destructive loads by simulating knee motion from 90° flexion to full extension. Anterior tension wiring as well as lag screws with tension wiring showed significant fracture displacement after the initial cycle already. Both constructs, lag screws plus wiring (3.7 ± 2.7 mm) as well as tension wiring alone (7.1 ± 2.2 mm) displayed fracture displacement of >2 mm which is clinically regarded as failure. Those patellae stabilized with fixed-angle plates showed no significant fracture gap widening after completion of 100 cycles (0.7 ± 0.5 mm). The differences between the fixed-angle plate group and the other two groups were statistically significant (ppatella fractures securely and sustainably. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Bending Under Tension Test with Direct Friction Measurement

    DEFF Research Database (Denmark)

    Andreasen, Jan Lasson; Olsson, David Dam; Chodnikiewicz, K.

    2004-01-01

    A special 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...

  14. Cyclic long-term loading of a bilateral fixed-angle plate in comparison with tension band wiring with K-wires or cannulated screws in transverse patella fractures.

    Science.gov (United States)

    Thelen, Simon; Schneppendahl, Johannes; Baumgärtner, Ralf; Eichler, Christian; Koebke, Jürgen; Betsch, Marcel; Hakimi, Mohssen; Windolf, Joachim; Wild, Michael

    2013-02-01

    A bilateral fixed-angle plate was biomechanically compared to the two currently preferred methods of osteosynthesis for transverse patella fractures. It was hypothesized that the new angle-stable implant would provide a secure and sustainable fracture fixation, superior to the established standard techniques. Twenty-one identical patellae made of polyurethane foam (Sawbones(®)), osteotomized to create a transverse two-part fracture, were fixed with modified anterior tension wiring, cannulated lag screws with anterior tension wiring or bilateral polyaxial 2.7-mm fixed-angle plates. The testing protocol consisted of 10,000 repetitive cycles using a non-destructive physiological load between 100 and 300 N at a simulated knee flexion of 60°. All 21 Sawbone(®)-patellae sustained repetitive loading up to 10,000 cycles without failing. The anterior tension wire group displayed significant displacement of the fracture gap (0.7 ± 0.2 mm) during cyclic loading, while both lag screws with tension wiring and bilateral fixed-angle plates showed no fracture gap widening at all (p fracture gap over 10,000 tensile cycles in contrast to modified anterior tension wiring, which exhibited significant widening of the gap after initial loading. Results of in vitro testing indicate that bilateral fixed-angle plates provide sustainable fixation stability offering a promising new option in the treatment for transverse patella fractures.

  15. A tool for measuring the bending length in thin wires.

    Science.gov (United States)

    Lorenzini, M; Cagnoli, G; Cesarini, E; Losurdo, G; Martelli, F; Piergiovanni, F; Vetrano, F; Viceré, A

    2013-03-01

    Great effort is currently being put into the development and construction of the second generation, advanced gravitational wave detectors, Advanced Virgo and Advanced LIGO. The development of new low thermal noise suspensions of mirrors, based on the experience gained in the previous experiments, is part of this task. Quasi-monolithic suspensions with fused silica wires avoid the problem of rubbing friction introduced by steel cradle arrangements by directly welding the wires to silica blocks bonded to the mirror. Moreover, the mechanical loss level introduced by silica (φfs ∼ 10(-7) in thin fused silica wires) is by far less than the one associated with steel. The low frequency dynamical behaviour of the suspension can be computed and optimized, provided that the wire bending shape under pendulum motion is known. Due to the production process, fused silica wires are thicker near the two ends (necks), so that analytical bending computations are very complicated. We developed a tool to directly measure the low frequency bending parameters of fused silica wires, and we tested it on the wires produced for the Virgo+ monolithic suspensions. The working principle and a set of test measurements are presented and explained.

  16. Yield stress and elasticity influence on surface tension measurements.

    Science.gov (United States)

    Jørgensen, Loren; Le Merrer, Marie; Delanoë-Ayari, Hélène; Barentin, Catherine

    2015-07-07

    We have performed surface tension measurements on carbopol gels of different concentrations and yield stresses. Our setup, based on the force exerted by a capillary bridge on two parallel plates, allows us to measure an apparent surface tension of the complex fluid and to investigate the influence of flow history. More precisely the apparent surface tension measured after stretching the bridge is always higher than after compressing it. The difference between the two values is due to the existence of a yield stress in the fluid. The experimental observations are successfully reproduced with a simple elasto-plastic model. The shape of successive stretching-compression cycles can be described by taking into account the yield stress and the elasticity of the gel. We show that the surface tension γLV of yield stress fluids is the mean of the apparent surface tension values only if the elastic modulus is high compared to the yield stress. This work highlights that measurements of thermodynamic quantities are challenged by the fluid out-of-equilibrium state implied by jamming, even at small scales where the shape of the bridge is driven by surface energy. Therefore setups allowing for deformation in opposite directions are relevant for surface tension measurements on yield stress fluids.

  17. Measuring oxygen tension in the anterior chamber of rabbits.

    Science.gov (United States)

    McLaren, J W; Dinslage, S; Dillon, J P; Roberts, J E; Brubaker, R F

    1998-09-01

    Measuring the concentration of oxygen in the aqueous humor without penetrating the eye would provide a new dimension in understanding aqueous humor and corneal dynamics. In this study a preinvasive method was developed for determining the cameral oxygen concentration in anesthetized rabbits by measuring the excited-state lifetime of a phosphorescent dye. A scanning ocular fluorometer was designed to excite phosphorescence with a brief flash of light and to measure the decay of luminescence for as long as 1000 microsec after excitation. The measurement window was scanned through the depth of the anterior chamber or fixed at the mid-anterior chamber. A depot of the phosphorescent dye Pd-uroporphyrin was injected into the vitreous of eight pigmented rabbits, and within a few days the dye was measurable in the anterior chamber. The excited-state lifetime of this dye is inversely correlated to oxygen concentration and was calibrated by measuring the lifetime of dye in cuvettes equilibrated with oxygen-nitrogen mixtures. Oxygen tensions were determined from lifetimes measured in the open eye, under a polymethylmethacrylate (PMMA) contact lens, under two oxygen-permeable contact lenses, and immediately after lid closure. Oxygen tension in the mid-anterior chamber before placing a PMMA contact lens was 23 +/- 3 mm Hg (mean +/- SD; n = 6). After 20 minutes of PMMA lens wear, oxygen tension decreased to 4 +/- 2 mm Hg. When the focal diamond was scanned through the anterior chamber, oxygen tension was 24 +/- 5 mm Hg near the corneal endothelium and decreased to 17 +/- 8 mm Hg near the crystalline lens. Under the PMMA contact lens this gradient reversed: Oxygen tensions near the endothelium and lens were 3 +/- 2 mm Hg and 6 +/- 2 mm Hg, respectively. Lid closure for 10 minutes or longer decreased the mid-anterior chamber oxygen tension from 21 +/- 2 mm Hg (n = 19 measurements from seven animals) to 10 +/- 3 mm Hg (n = 15 measurements from five animals). Measuring excited

  18. On the Humidity Sensitivity of Hot-Wire Measurements

    DEFF Research Database (Denmark)

    Larsen, Søren Ejling; Busch, N. E.

    1980-01-01

    The influence of humidity changes on hot-wire measurements is discussed. Indications are that the humidity sensitivity parameters obtained by the authors in an earlier paper should be changed. This means, however, that the agreement between predicted and measured sensitivities ceases to exist...

  19. Measurement of dynamic surface tension by mechanically vibrated sessile droplets.

    Science.gov (United States)

    Iwata, Shuichi; Yamauchi, Satoko; Yoshitake, Yumiko; Nagumo, Ryo; Mori, Hideki; Kajiya, Tadashi

    2016-04-01

    We developed a novel method for measuring the dynamic surface tension of liquids using mechanically vibrated sessile droplets. Under continuous mechanical vibration, the shape of the deformed droplet was fitted by numerical analysis, taking into account the force balance at the drop surface and the momentum equation. The surface tension was determined by optimizing four parameters: the surface tension, the droplet's height, the radius of the droplet-substrate contact area, and the horizontal symmetrical position of the droplet. The accuracy and repeatability of the proposed method were confirmed using drops of distilled water as well as viscous aqueous glycerol solutions. The vibration frequency had no influence on surface tension in the case of pure liquids. However, for water-soluble surfactant solutions, the dynamic surface tension gradually increased with vibration frequency, which was particularly notable for low surfactant concentrations slightly below the critical micelle concentration. This frequency dependence resulted from the competition of two mechanisms at the drop surface: local surface deformation and surfactant transport towards the newly generated surface.

  20. A Modified Jaeger's Method for Measuring Surface Tension.

    Science.gov (United States)

    Ntibi, J. Effiom-Edem

    1991-01-01

    A static method of measuring the surface tension of a liquid is presented. Jaeger's method is modified by replacing the pressure source with a variable pressure head. By using this method, stationary air bubbles are obtained thus resulting in controllable external parameters. (Author/KR)

  1. Measurement of the angle of superficial tension by images

    Science.gov (United States)

    Yanez M., Javier; Alonso R., Sergio

    2006-02-01

    When a liquid is deposited on a surface, this one form a certain angle with respect to the surface, where depending on its value, it will conclude that so hard it is his adhesion with the surface. By means of the analysis of images we looked for to measure this angle of superficial tension. In order to make this measurement, we propose a technique by means of projective transformations and one method of regression to estimation parameters to conic fitting.

  2. Study Of Bubble-Count Measurement Of Surface Tension

    Science.gov (United States)

    Nishioka, Gary M.; Berg, James I.

    1993-01-01

    Report presents study of bubble-count method of measurement of surface or interfacial tension of liquids. In method, gas or liquid pumped at known rate along capillary tube. One end of tube open and immersed in liquid that wets tube. Pumped gas or liquid forms bubbles, detaching themselves from immersed open end of tube, and one measures average period, Pi, for formation and detachment of bubbles.

  3. Sidewall roughness measurement of photonic wires and photonic crystals

    DEFF Research Database (Denmark)

    Svalgaard, Mikael; Frandsen, Lars Hagedorn; Garnæs, Jørgen

    2007-01-01

    The performance of nanophotonic building blocks such as photonic wires and photonic crystals are rapidly improving, with very low propagation loss and very high cavity Q-factors being reported. In order to facilitate further improvements in performance the ability to quantitatively measure...... topological imperfections such as sidewall roughness on a sub-nm scale becomes essential. In this paper we use atomic force microscopy (AFM) on tilted samples to obtain the most detailed sidewall roughness measurements yet on nanophotonic structures....

  4. Measurement of surface and interfacial tension using pendant drop tensiometry.

    Science.gov (United States)

    Berry, Joseph D; Neeson, Michael J; Dagastine, Raymond R; Chan, Derek Y C; Tabor, Rico F

    2015-09-15

    Pendant drop tensiometry offers a simple and elegant solution to determining surface and interfacial tension - a central parameter in many colloidal systems including emulsions, foams and wetting phenomena. The technique involves the acquisition of a silhouette of an axisymmetric fluid droplet, and iterative fitting of the Young-Laplace equation that balances gravitational deformation of the drop with the restorative interfacial tension. Since the advent of high-quality digital cameras and desktop computers, this process has been automated with high speed and precision. However, despite its beguiling simplicity, there are complications and limitations that accompany pendant drop tensiometry connected with both Bond number (the balance between interfacial tension and gravitational forces) and drop volume. Here, we discuss the process involved with going from a captured experimental image to a fitted interfacial tension value, highlighting pertinent features and limitations along the way. We introduce a new parameter, the Worthington number, Wo, to characterise the measurement precision. A fully functional, open-source acquisition and fitting software is provided to enable the reader to test and develop the technique further. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

  5. Comparison of Tension-Band Wiring With the Cable Pin System in Patella Fractures: A Randomized Prospective Study.

    Science.gov (United States)

    Tian, Qing-xian; Hai, Yong; Du, Xin-ru; Xu, Zi-yu; Lu, Tie; Shan, Lei; Liu, Yang; Zhou, Jun-lin

    2015-12-01

    To compare the outcome of tension-band wiring (TBW) with the cable pin system (CPS) for transverse fractures of the patella. Randomized prospective study. Academic Level I trauma center. From February 2008 to December 2011, 73 consecutive patients with transverse fractures of the patella were prospectively enrolled in this study. The patients were randomly divided into 2 groups: one group was treated using the CPS, and the other group was treated using the modified TBW. The clinical outcome assessment included analyses of the radiographic images, the modified Hospital for Special Surgery scoring system, and complications. The follow-up time ranged from 12 to 29 months. All fractures healed, with a union rate of 100%. The fracture healing time was significantly shorter in the CPS group (8.51 ± 2.59 weeks, n = 34) compared with the TBW group (11.79 ± 3.04 weeks, n = 39). Postoperative complications in the CPS and TBW groups were observed in 1 and 9 patients, respectively, a difference that was statistically significant. The mean Hospital for Special Surgery score for the CPS group (90.53 ± 5.19 points) was significantly higher than that for the TBW group (81.36 ± 12.71 points). The CPS is a viable option for transverse fractures of the patella and is associated with a shorter healing time, fewer complications, and better function than TBW. Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

  6. Magnetic Field Measurements in Wire-Array Z-Pinches

    Science.gov (United States)

    Syed, Wasif; Hammer, David; Lipson, Michal

    2006-10-01

    Understanding the evolution of the magnetic field topology and magnitude in the high energy density plasmas produced by wire-array Z-pinches is of critical importance for their ultimate application to stockpile stewardship and inertial confinement fusion^1. A method to determine the magnetic field profile in megampere level wire-array Z-pinches with high spatial and temporal resolution is under development. An ideal method would be passive and non-perturbing, such as Faraday rotation of laser light. We are developing a method involving temporally-resolved Faraday rotation through a sensing waveguide placed in the vicinity of, and eventually in, a wire-array Z-pinch^2. We present measurements of the magnetic field outside of a wire-array, and progress on measurements within the array. Our ideal device is a ``thin film waveguide'' coupled to an optical fiber system. While these sensing devices may not survive for long in a dense Z-pinch, they may provide useful information for a significant fraction of the current pulse. We present preliminary theoretical and experimental results. 1. M. Keith Matzen, M. A. Sweeney, R. G. Adams et al., Phys. Plasmas 12, 055503 (2005). 2. W. Syed, D. A. Hammer, M. Lipson, R. B. van Dover, AIP Proceedings of the 6th International Conference on Dense Z-Pinches, University of Oxford, UK, July 25-28, 2005. *This research was sponsored by the National Nuclear Security Administration under the Stockpile Stewardship Academic Alliances program through DOE Cooperative Agreement DE-F03-02NA00057.

  7. Accuracy of Transcutaneous Carbon Dioxide Tension Measurements during Cardiopulmonary Exercise Testing

    National Research Council Canada - National Science Library

    Stege, Gerben; van den Elshout, Frank J.J; Heijdra, Yvonne F; van de Ven, Marjo J.T; Dekhuijzen, P.N. Richard; Vos, Petra J.E

    2009-01-01

    Background: Measurements of transcutaneous carbon dioxide tension (PtcCO ) with current devices are proven to provide clinically acceptable agreement with measurements of partial arterial carbon dioxide tension (PaCO...

  8. Pressure wire used to measure gradient in chronic mesenteric ischemia.

    Science.gov (United States)

    Hannawi, Bashar; Lam, Wilson W; Younis, George Antoine

    2012-01-01

    Chronic mesenteric ischemia is a rare disorder in the United States. Frequently, its symptoms correlate poorly with the angiographically apparent degree of mesenteric artery stenosis. Measuring the pressure gradient with a small-caliber catheter is an established means of determining whether a particular stenosis is flow-limiting, thus guiding the interventional decision when stenoses are of indeterminate angiographic significance. Using a 0.014-in guidewire, however, is potentially more accurate because it eliminates any measurement error attributable to the use of a larger, potentially obstructive catheter. We present a case of chronic mesenteric ischemia in a 70-year-old woman who had abdominal pain with multiple possible causes. We used a 0.014-in pressure wire to calculate pressure gradients and guide our decision to stent tandem lesions in the superior mesenteric artery. After revascularization, the patient's symptoms improved dramatically. To the best of our knowledge, this is the first published case in which a pressure wire was used to measure a pressure gradient in chronic mesenteric ischemia.

  9. [Measurement of oxygen tension in normal and varicose vein walls].

    Science.gov (United States)

    Taccoen, A; Lebard, C; Borie, H; Poullain, J C; Zuccarelli, F; Gerentes, I; Stern, S; Guichard, M

    1996-01-01

    Oxygen tension (PO2) was investigated in vivo in the long saphenous vein from 21 varicose patients (31 veins) during venous surgery and 7 patients with normal venous network undergoing popliteo-femoral by-pass. Measurement was achieved using computerized polarographic system Kimoc 6650 (Eppendorf, Hamburg) providing a microdriven stepwise progression of a needle probe. Oxygen tension profile was similar in both groups of patients. A slow PO2 decrease was observed from adventitia up to the union of the middle and inner thirds of the media where values were at the lowest then followed by a marked increased in the intima and the saphenous lumen. Oxygenation of the two external thirds of the venous wall was provided by vasa vasorum. The average minimum values in the media was significantly reduced in varicose veins compared to no-varicose veins (7,9 mmHg versus 13,4 mmHg; p vein nutrition and suggest a primary or secondary deficiency in oxygen supply in varicose veins.

  10. Efficacy and safety of tension band wiring versus plate fixation in olecranon fractures: a systematic review and meta-analysis.

    Science.gov (United States)

    Ren, Yi-Ming; Qiao, Hu-Yun; Wei, Zhi-Jian; Lin, Wei; Fan, Bao-You; Liu, Jun; Li, Ang; Kang, Yi; Liu, Shen; Hao, Yan; Zhou, Xian-Hu; Feng, Shi-Qing

    2016-11-14

    Olecranon fracture (OF) is a common upper limb fracture, and the most commonly used techniques are still tension band wiring (TBW) and plate fixation (PF). The aim of the current study is to discuss whether TBW or PF technique of internal fixation is better in the treatment of OFs, using the method of meta-analysis. The eligible studies were acquired from PubMed, CNKI, Embase, Cochrane Library, and other sources. The data were extracted by two of the coauthors independently and were analyzed by RevMan5.3. Standardized mean differences (SMDs), odds ratios (ORs), and 95% confidence intervals (CIs) were calculated. Cochrane Collaboration's Risk of Bias Tool and Newcastle-Ottawa Scale were used to assess risk of bias. Thirteen studies including 1 RCT and 12 observational studies were assessed. Our meta-analysis results showed that both in RCT and observational studies, there were no significant differences between the two groups in disabilities of the arm, shoulder and hand (DASH) (SMD = 0.07, 95% CI = -0.32 to 0.46, p = 0.73), improvement rate (OR = 0.76, 95% CI = 0.48-1.22, p = 0.26), range of motion (ROM), operation time (SMD = -0.51, 95% CI = -1.17 to 0.14, p = 0.12) and blood loss (SMD = -0.97, 95% CI = -2.06 to 0.11, p = 0.08). The overall estimate of complications indicated that the pooled OR was 2.61 (95% CI = 1.65-4.14, p current study reveals that there are no significant differences in DASH, improvement rate, ROM, operation time, and blood loss between TBW and PF for OFs. Due to the less complications, we recommend the PF approach as the optical choice for OFs. More high-quality studies are required to further confirm our results.

  11. Tyrolean tensiometer: a new instrument for easy intraoperative tension measurement before vascular anastomosis.

    Science.gov (United States)

    Schubert, Heinrich M; Hohlrieder, Matthias; Buchegger, Johannes W; Brodbeck, Achim F; Hager, Martina; Zimmermann, Robert F; Moser, Thomas M

    2007-01-01

    In reconstructive surgery microsurgical repair of dissected arteries sometimes has to be done under longitudinal tension. Guidelines to support an objective decision on whether tension associated with direct suture is acceptable or whether grafting is needed, do not exist. All experimental data found concerned the clinical outcome of a certain length defect treated in various animal models. The aim of this study was to show the feasibility of a new instrument for measuring the tension required to adapt arterial stumps, thereby allowing surgical outcome to be assessed before beginning anastomosis. A modified tension spring balance was used to measure the force applied to the arterial stumps before knotting. Twenty-four rat femoral arteries were dissected, segments of up to 9mm were resected, and the tension needed for approximation was measured. These ex-vivo data were combined with clinical outcome data of previous animal trials. The tension measured increased proportionally to the size of the arterial gap created. The correlation between tension and arterial gap was found to be almost linear. The average additional time required for tension measurement using the Tyrolean Tensiometer was 13 (+/-6) s. High anastomotic tension may cause critical or even poor clinical outcome. None of the tension measurement methods described so far allow intraoperative measurement at a time when changes in strategy are still possible. The Tyrolean Tensiometer for the first time allows fast and reliable measurement of the tension acting on the first suture of an anastomosis.

  12. Bubble reconstruction method for wire-mesh sensors measurements

    Science.gov (United States)

    Mukin, Roman V.

    2016-08-01

    A new algorithm is presented for post-processing of void fraction measurements with wire-mesh sensors, particularly for identifying and reconstructing bubble surfaces in a two-phase flow. This method is a combination of the bubble recognition algorithm presented in Prasser (Nuclear Eng Des 237(15):1608, 2007) and Poisson surface reconstruction algorithm developed in Kazhdan et al. (Poisson surface reconstruction. In: Proceedings of the fourth eurographics symposium on geometry processing 7, 2006). To verify the proposed technique, a comparison was done of the reconstructed individual bubble shapes with those obtained numerically in Sato and Ničeno (Int J Numer Methods Fluids 70(4):441, 2012). Using the difference between reconstructed and referenced bubble shapes, the accuracy of the proposed algorithm was estimated. At the next step, the algorithm was applied to void fraction measurements performed in Ylönen (High-resolution flow structure measurements in a rod bundle (Diss., Eidgenössische Technische Hochschule ETH Zürich, Nr. 20961, 2013) by means of wire-mesh sensors in a rod bundle geometry. The reconstructed bubble shape yields bubble surface area and volume, hence its Sauter diameter d_{32} as well. Sauter diameter is proved to be more suitable for bubbles size characterization compared to volumetric diameter d_{30}, proved capable to capture the bi-disperse bubble size distribution in the flow. The effect of a spacer grid was studied as well: For the given spacer grid and considered flow rates, bubble size frequency distribution is obtained almost at the same position for all cases, approximately at d_{32} = 3.5 mm. This finding can be related to the specific geometry of the spacer grid or the air injection device applied in the experiments, or even to more fundamental properties of the bubble breakup and coagulation processes. In addition, an application of the new algorithm for reconstruction of a large air-water interface in a tube bundle is

  13. Survismeter, 3-in-1 Instrument for Simultaneous Measurements of Surface Tension, Inter Facial Tension (IFT and Viscosity

    Directory of Open Access Journals (Sweden)

    Man Singh

    2007-12-01

    Full Text Available The article presents Inter Facial Tension (IFT (ift, N m-1 of benzene-water; surface tensions (, N m-1 and viscosities (, N s m-2 of ethanol, glycerol, ethyl acetate, n-hexane, diethyl ether, chloroform, benzene, carbon tetrachloride [CCl4], formic acid, measured with Survismeter with ± 1.1x10-5 N m-1, ± 1.3x10-5 N m-1 and ± 1.1x10-6 N s m-2 accuracies respectively. Also the surface tension and viscosities of carboxymethylcellulose (CMC, dodecylbenzenesulfonicacid (DBSA and tetramethylammoniumhydroxide (TMAH in aqueous media have been measured with survismeter at 298.15 K. IFT of water and benzene interface was determined with survismeter. The survismeter saves resources, user’s efforts and infrastructure more than 80 % as compared to usual methods and prevents 80% disposal of materials to environment. It very accurately measures surface tension and IFT of volatile and poisonous liquids at any desired temperatures as liquids are jacked (jacketed in closed glass made bulbs.

  14. Optical Thomson scattering measurements of cylindrical wire array parameters

    Energy Technology Data Exchange (ETDEWEB)

    Harvey-Thompson, A. J.; Lebedev, S. V.; Patankar, S.; Bland, S. N.; Burdiak, G.; Chittenden, J. P.; Colaitis, A.; De Grouchy, P.; Hall, G. N.; Khoory, E.; Pickworth, L.; Suzuki-Vidal, F.; Smith, R. A.; Skidmore, J.; Suttle, L.; Swadling, G. F. [Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom); Hohenberger, M. [Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627 (United States)

    2012-05-15

    A Thomson scattering diagnostic has been used to measure the parameters of cylindrical wire array Z pinch plasmas. The scattering operates in the collective regime ({alpha}>1) allowing spatially localised measurements of the ion or electron plasma temperatures and of the plasma bulk velocity. The ablation flow is found to accelerate towards the axis reaching peak velocities of 1.2-1.3 Multiplication-Sign 10{sup 7} cm/s in aluminium and {approx}1 Multiplication-Sign 10{sup 7} cm/s in tungsten arrays. Measurements of the precursor ion temperature shortly after formation are found to correspond to the kinetic energy of the converging ablation flow. Measurements during the implosion phase of tungsten arrays show the main imploding mass reaches velocities of {approx}1.4-1.7 Multiplication-Sign 10{sup 7} cm/s and is non-zero even at large radii close to the start of the x-ray pulse indicating current flow in the trailing mass.

  15. Influence of specimen type and reinforcement on measured tension-tension fatigue life of unidirectional GFRP laminates

    DEFF Research Database (Denmark)

    Korkiakoski, Samuli; Brøndsted, Povl; Sarlin, Essi

    2016-01-01

    It is well known that standardised tension-tension fatigue test specimens of unidirectional (UD) glass-fibre-reinforced plastics (GFRP) laminates tend to fail at end tabs. The true fatigue life is then underestimated. The first objective of this study was to find for UD GFRP laminates a test spec...... a significant effect on the failure mode and measured fatigue life of the laminates. A significantly higher fatigue life was measured for the laminate with the powder-bound fabric reinforcement when compared to the laminate with the stitched reinforcement.......It is well known that standardised tension-tension fatigue test specimens of unidirectional (UD) glass-fibre-reinforced plastics (GFRP) laminates tend to fail at end tabs. The true fatigue life is then underestimated. The first objective of this study was to find for UD GFRP laminates a test...... specimen that fails in the gauge section. The second objective was to compare fatigue performance of two laminates, one having a newly developed UD powder-bound fabric as a reinforcement and the other having a quasi-UD stitched non-crimp fabric as a reinforcement. In the first phase, a rectangular specimen...

  16. Measurement of the airflow velocity upstream and downstream a wire mesh using constant temperature anemometry

    Directory of Open Access Journals (Sweden)

    Lizal Frantisek

    2014-03-01

    Full Text Available Measurement of velocity upstream and downstream a special wire mesh was performed to ascertain the effect of the mesh on the flow. The mesh consisted of two components, a basic rectangular mesh with mesh width 1.22 mm and wire diameter 0.2 mm, and a top steel wool with random position of wires and wire diameter 0.05 mm. The velocity was measured by Constant Temperature Anemometry using single wire probe in a Plexiglas channel of rectangular cross-section. As a first step, measurement of one horizontal and one vertical measuring line was performed 10 mm upstream and 6 mm downstream the wire mesh. A spatial velocity profile upstream of the wire mesh was smooth, while the downstream velocity profile was highly disturbed. However, velocity fluctuations expressed in terms of turbulence intensity downstream of the wire mesh were attenuated down to 1%. Further measurements of the area downstream the wire mesh will be performed to describe the development of the flow.

  17. Local deformation method for measuring element tension in space deployable structures

    Directory of Open Access Journals (Sweden)

    Belov Sergey

    2017-01-01

    Full Text Available The article describes the local deformation method to determine the tension of cord and thin membrane elements in space deployable structure as antenna reflector. Possible measuring instrument model, analytical and numerical solutions and experimental results are presented. The boundary effects on measurement results of metallic mesh reflector surface tension are estimated. The study case depicting non-uniform reflector surface tension is considered.

  18. Plasma density measurements in tungsten wire-array Z-pinches

    Energy Technology Data Exchange (ETDEWEB)

    Douglass, J. D.; Hammer, D. A.; Pikuz, S. A.; Shelkovenko, T. A.; Blesener, K. S. [Laboratory of Plasma Studies, Cornell University, Ithaca, New York 14853 (United States)

    2012-07-15

    Measurements of the plasma density profile near the exploding wires in 1 MA tungsten (W) wire-array Z-pinches have been made using calibrated x-ray absorption. As many as 5 x-ray images per pulse were obtained between 65 and 160 ns after the start of the 100 ns rise time current pulse. Measured W ion densities range from above 10{sup 19}/cm{sup 3} close to the wire to {approx}10{sup 17}/cm{sup 3} about 1 mm away from the wire in the plasma stream. After accurate geometrical registration of the individual wires in each successive image in a pulse using the Genetic Algorithm, the temporal evolution of the axial modulation wavelength distribution of the ablation rate from the wires in each array and the global mass-ablation rate as a function of time are presented.

  19. Measurement of 3-Axis Magnetic Fields Induced by Current Wires Using a Smartphone in Magnetostatics Experiments

    Science.gov (United States)

    Setiawan, B.; Septianto, R. D.; Suhendra, D.; Iskandar, F.

    2017-01-01

    This paper describes the use of an inexpensive smartphone's magnetic sensor to measure magnetic field components (B[subscript x], B[subscript y] and B[subscript z]) induced by current wires in magnetostatic experiments. The variable parameters used to measure the magnetic sensor's capabilities were: the geometrical shapes of the wire, current…

  20. Research regarding stiffness optimization of wires used for joints actuation from an elephant's trunk robotic arm

    Science.gov (United States)

    Ciofu, C.; Stan, G.

    2016-11-01

    Elephant's trunk robotic arms driven by wires and pulley mechanisms have issues with wires stiffness because of the entailed elastic deformations that is causing errors of positioning. Static and dynamic loads from each joint of the robotic arm affect the stiffness of driving wires and precision positioning. The influence of wires elastic deformation on precision positioning decreases with the increasing of wires stiffness by using different pre-tensioning devices. In this paper, we analyze the variation of driving wires stiffness particularly to each wire driven joint. We obtain optimum wires stiffness variation by using an analytical method that highlights the efficiency of pre-tensioning mechanism. The analysis of driving wires stiffness is necessary for taking appropriate optimization measures of robotic arm dynamic behavior and, thus, for decreasing positioning errors of the elephant's trunk robotic arm with inner actuation through wires/cables.

  1. Accuracy of transcutaneous carbon dioxide tension measurements during cardiopulmonary exercise testing.

    NARCIS (Netherlands)

    Stege, G.; Elshout, F.J.J. van den; Heijdra, Y.F.; Ven, M.J.T. van de; Dekhuijzen, P.N.R.; Vos, P.J.E.

    2009-01-01

    BACKGROUND: Measurements of transcutaneous carbon dioxide tension (PtcCO(2)) with current devices are proven to provide clinically acceptable agreement with measurements of partial arterial carbon dioxide tension (PaCO(2)) in several settings but not during cardiopulmonary exercise testing (CPET).

  2. Tyrolean tensiometer: A new instrument for easy intraoperative tension measurement before nerve coaptation.

    Science.gov (United States)

    Schubert, Heinrich M; Moser, Thomas M; Buchegger, Johannes W; Brodbeck, Achim F; Schoeller, Thomas; Zimmermann, Robert F; Hohlrieder, Matthias

    2006-09-01

    In reconstructive surgery microsurgical repair of dissected nerves can be done end-to-end or by using a nerve graft. Guidelines to support an objective decision, whether tension associated with direct suture is acceptable or grafting is needed, do not exist. All experimental data found concerned the clinical outcome when a certain length defect was treated in various animal models. The aim of this study was to show the feasibility of a new instrument for measuring the tension needed to coapt nerve stumps before beginning nerve suture. A tension spring balance was modified in a way that the thread of the first suture is used to measure the force applied to the two nerve stumps by the suture before knotting. Immediately after measuring, the suture can be completed by knotting. Twenty-four rat sciatic nerves were dissected, segments of various length were resected, and tension needed for approximation was measured. These ex vivo data were combined with clinical outcome data of previous animal trials. Data obtained showed that tension measured increased almost proportionally to the size of the gap created. The average additional time needed to measure the tension using the Tyrolean Tensiometer was 11 (+/-4) seconds. None of the methods described before allow intraoperative tension measurement at a time when changes in strategy are still possible. The Tyrolean Tensiometer allows fast and reliable measurement of the tension acting on the first suture and might hereby be useful in predicting final operative outcome.

  3. First Experimental Results And Improvements On Profile Measurements With The Vibrating Wire Scanner

    CERN Document Server

    Arutunian, S G; Dobrovolski, N M; Mailian, M R; Soghoyan, H E; Vasiniuk, I E

    2003-01-01

    The paper presents the first experimental results of transverse profile scans using a wire scanner based on a vibrating wire (vibrating wire scanner - VWS). The measurements were performed at the injector electron beam (6 nA) of the Yerevan synchrotron. The beam profile information is obtained by measuring the wire natural oscillations that depend on the wire temperature. This first experiments on weak electron beam proved this new method as a very sensitive tool, even suitable for tail measurements. Additional, improvements were tested to overcome some problems connected with signal conditioning and signal transfer in the presence of electromagnetic noise. As a result the noises were neatly separated and reduced. A mathematical method for rejection of distorted data was developed. Experiments with the scanner at the PETRA accelerator at DESY are planned for measurements of beam tails.

  4. Transverse Beam Halo Measurements at High Intensity Neutrino Source (HINS) using Vibrating Wire Monitor

    Energy Technology Data Exchange (ETDEWEB)

    Chung, M.; Hanna, B.; Scarpine, V.; Shiltsev, V.; Steimel, J.; Artinian, S.; Arutunian, S.

    2015-02-26

    The measurement and control of beam halos will be critical for the applications of future high-intensity hadron linacs. In particular, beam profile monitors require a very high dynamic range when used for the transverse beam halo measurements. In this study, the Vibrating Wire Monitor (VWM) with aperture 60 mm was installed at the High Intensity Neutrino Source (HINS) front-end to measure the transverse beam halo. A vibrating wire is excited at its resonance frequency with the help of a magnetic feedback loop, and the vibrating and sensitive wires are connected through a balanced arm. The sensitive wire is moved into the beam halo region by a stepper motor controlled translational stage. We study the feasibility of the vibrating wire for the transverse beam halo measurements in the low-energy front-end of the proton linac.

  5. Humidity-dependent surface tension measurements of individual inorganic and organic submicrometre liquid particles.

    Science.gov (United States)

    Morris, Holly S; Grassian, Vicki H; Tivanski, Alexei V

    2015-05-01

    Surface tension, an important property of liquids, is easily measured for bulk samples. However, for droplets smaller than one micron in size, there are currently no reported measurements. In this study, atomic force microscopy (AFM) and force spectroscopy have been utilized to measure surface tension of individual submicron sized droplets at ambient pressure and controlled relative humidity (RH). Since the surface tension of atmospheric aerosols is a key factor in understanding aerosol climate effects, three atmospherically relevant systems (NaCl, malonic and glutaric acids) were studied. Single particle AFM measurements were successfully implemented in measuring the surface tension of deliquesced particles on the order of 200 to 500 nm in diameter. Deliquesced particles continuously uptake water at high RH, which changes the concentration and surface tension of the droplets. Therefore, surface tension as a function of RH was measured. AFM based surface tension measurements are close to predicted values based on bulk measurements and activities of these three chemical systems. Non-ideal behaviour in concentrated organic acid droplets is thought to be important and the reason for differences observed between bulk solution predictions and AFM data. Consequently, these measurements are crucial in order to improve atmospheric climate models as direct measurements hitherto have been previously inaccessible due to instrument limitations.

  6. Complications of lateral plate fixation compared with tension band wiring and pin or lag screw fixation for calcaneoquartal arthrodesis. Treatment of proximal intertarsal subluxation occurring secondary to non-traumatic plantar tarsal ligament disruption in dogs.

    Science.gov (United States)

    Barnes, D C; Knudsen, C S; Gosling, M; McKee, M; Whitelock, R G; Arthurs, G I; Ness, M G; Radke, H; Langley-Hobbs, S J

    2013-01-01

    To compare complication rates and the outcomes of these complications after lateral plate fixation with figure-of-eight tension-band-wire and pin or lag screw fixation for arthrodesis of the calcaneoquartal joint, following non-traumatic disruption of the plantar tarsal ligament in dogs. Data were collected retrospectively from five UK referral centres. Diplomate specialists and their residents performed all procedures. Referring veterinarians were contacted for long-term follow-up. Seventy-four procedures were undertaken in 61 dogs. There were 58 arthrodeses in the lateral plate group (Plate), nine in the pin and tension-band-wire group (Pin), and seven in the lag screw and tension-band wire-group (Screw). Compared to Plate (17%), further surgical intervention was required more frequently following Pin (56%, OR = 3.2) or Screw (43%, OR = 2.5) fixation. Clinical failure of arthrodesis occurred less frequently with Plate (5%) compared with Screw (43%, OR = 8.6) and Pin fixation (22%, OR = 4.4). Cases managed with external coaptation postoperatively were more likely to suffer from postoperative complications (OR = 2.2). Lateral plating was associated with fewer postoperative complications than pin and tension-band-wire fixation for arthrodesis of the calcaneoquartal joint in dogs with non-traumatic disruption of the plantar tarsal ligament.

  7. Photonic wires sidewall roughness measures using AFM capabilities

    DEFF Research Database (Denmark)

    Malureanu, Radu; Frandsen, Lars Hagedorn

    2008-01-01

    Within the last years, interest in photonic wires and photonic crystals grew due to their demonstrated ability of controlling light propagation and characteristics. One of the limitations of such devices is due to the induced roughness during the fabrication process. Generally, an increase in rou...... be quantified and thus actions in decreasing it can be taken improving the device's performance....

  8. Analysis of pulsed wire method for field integral measurements in ...

    Indian Academy of Sciences (India)

    of the acoustic wave in the wire could be significant and our analysis provides a method for the evaluation of the magnetic field profile even in such cases taking the effect due to dispersion into account in an exact way. Keywords. Undulator; free-electron laser; synchrotron radiation source; magnetic char- acterization.

  9. Analysis of pulsed wire method for field integral measurements in ...

    Indian Academy of Sciences (India)

    In this paper, we present a theoretical analysis of this technique by finding out the analytic solution of the differential equation for the forced vibration of the wire taking dispersion due to stiffness into account. Method of images is used to extend these solutions to include reflections at the ends. For long undulators, the effect of ...

  10. Comparison of cannulated screw with tension band wiring versus compressive cannulated locking bolt and nut device (CompresSURE) in patella fractures-a cadaveric biomechanical study.

    Science.gov (United States)

    Domby, Brian; Henderson, Eric; Nayak, Aniruddh; Erdoğan, Murat; Gutierrez, Sergio; Santoni, Brandon G; Sagi, H Claude

    2012-12-01

    The purpose of this study was to determine if proximity of cannulated lag screws to the articular surface of the patella combined with the tension band technique affects resistance to fracture gap opening, and if an alternative locking nut and bolt device without a tension band behaves in a biomechanically similar fashion. Thirty-three cadaveric knees were allocated to 3 transverse patella fracture fixation groups: cannulated lag screw placement close to the articular (TBA) or non-articular (TBNA) surface with tension, and placement of a compressive locking nut and bolt device without tension band (CompresSURE) close to the articular surface. Knees were cycled through flexion-extension motion for 1000 cycles during which the fracture gap opening was quantified after the first flexion-extension cycle and after the 1,000 th cycle using an optoelectronic motion analysis system. After the first range of motion cycle, there was no significant difference in fracture gap opening between the 3 groups on the articular surface (P > 0.600). Total fracture gap displacement after the 1,000 th cycle was not significantly different between groups (P > 0.408). In general and irrespective of fixation technique, fractures opened in a wedge-like fashion with larger measured gap on the ventral surface relative to the articulating surface. When combined with the tension band, the proximity of cannulated lag screws to the articular surface did not affect resistance to fracture gap opening. Additionally, the stand-alone CompreSURE cannulated locking nut and bolt device without tension band was able to resist fracture gap opening in transverse fractures as effectively as the cannulated screw with tension band technique.

  11. Application of a pull on a disk method to measure surface tension of liquids.

    Science.gov (United States)

    Carvalho, Thiago C; Horng, Michelle; McConville, Jason T

    2012-03-01

    The intrinsic property of liquids is a vital indicator of formulation performance and stability. Therefore, investigation of the interfacial phenomenon of surface tension is a routine procedure in the development of products in a wide variety of areas including foods, pharmaceuticals, cosmetics, and painting technologies. We hypothesize that studies related to the maximum pull on a rod can be extrapolated to disk geometry and applied to measure surface tension using a texture analyzer. A glass disk probe was attached to the arm of a texture analyzer and pulled from the liquid surface. The maximum force of detachment was used to calculate surface tension extrapolating from the theory of maximum pull on a rod. The surface tension of water, ethanol, and a hydroalcoholic solution was measured and compared with literature values to validate this hypothesis. The calculated values of surface tension for the liquids studied were within 5% of the reported values. Probe diameter appears to have an important role on surface tension accuracy compared with literature values. Slight discrepancies can be attributed to temperature control and leveling of liquid surface, although still in accordance with the reported values of surface tension measured using different methods. This study presents a simple, precise, and quick method to determine the surface tension of liquids from the maximum pull on a disk. Further studies are warranted to determine the optimum glass disk probe diameter for better accuracy.

  12. Dynamic surface tension measurements of ionic surfactants using maximum bubble pressure tensiometry

    Science.gov (United States)

    Ortiz, Camilla U.; Moreno, Norman; Sharma, Vivek

    Dynamic surface tension refers to the time dependent variation in surface tension, and is intimately linked with the rate of mass transfer of a surfactant from liquid sub-phase to the interface. The diffusion- or adsorption-limited kinetics of mass transfer to interfaces is said to impact the so-called foamability and the Gibbs-Marangoni elasticity of surfaces. Dynamic surface tension measurements carried out with conventional methods like pendant drop analysis, Wilhelmy plate, etc. are limited in their temporal resolution (>50 ms). In this study, we describe design and application of maximum bubble pressure tensiometry for the measurement of dynamic surface tension effects at extremely short (1-50 ms) timescales. Using experiments and theory, we discuss the overall adsorption kinetics of charged surfactants, paying special attention to the influence of added salt on dynamic surface tension.

  13. Measuring 10-20 T magnetic fields in single wire explosions using Zeeman splitting.

    Science.gov (United States)

    Banasek, J T; Engelbrecht, J T; Pikuz, S A; Shelkovenko, T A; Hammer, D A

    2016-10-01

    We have shown that the Zeeman splitting of the sodium (Na) D-lines at 5890 Å and 5896 Å can be used to measure the magnetic field produced by the current flowing in an exploding wire prior to wire explosion. After wire explosion, the lines in question are either not visible in the strong continuum from the exploding wire plasma, or too broad to measure the magnetic field by methods discussed in this paper. We have determined magnetic fields in the range 10-20 T, which lies between the small field and Paschen-Back regimes for the Na D-lines, over a period of about 70 ns on a 10 kA peak current machine. The Na source is evaporated drops of water with a 0.171 M NaCl solution deposited on the wire. The Na desorbs from the wire as it heats up, and the excited vapor atoms are seen in emission lines. The measured magnetic field, determined by the Zeeman splitting of these emission lines, estimates the average radial location of the emitting Na vapor as a function of time under the assumption the current flows only in the wire during the time of the measurement.

  14. Measuring 10-20 T magnetic fields in single wire explosions using Zeeman splitting

    Science.gov (United States)

    Banasek, J. T.; Engelbrecht, J. T.; Pikuz, S. A.; Shelkovenko, T. A.; Hammer, D. A.

    2016-10-01

    We have shown that the Zeeman splitting of the sodium (Na) D-lines at 5890 Å and 5896 Å can be used to measure the magnetic field produced by the current flowing in an exploding wire prior to wire explosion. After wire explosion, the lines in question are either not visible in the strong continuum from the exploding wire plasma, or too broad to measure the magnetic field by methods discussed in this paper. We have determined magnetic fields in the range 10-20 T, which lies between the small field and Paschen-Back regimes for the Na D-lines, over a period of about 70 ns on a 10 kA peak current machine. The Na source is evaporated drops of water with a 0.171 M NaCl solution deposited on the wire. The Na desorbs from the wire as it heats up, and the excited vapor atoms are seen in emission lines. The measured magnetic field, determined by the Zeeman splitting of these emission lines, estimates the average radial location of the emitting Na vapor as a function of time under the assumption the current flows only in the wire during the time of the measurement.

  15. Vibration Measurements of the Wire Scanner for the SwissFEL

    Science.gov (United States)

    Mohanmurthy, Prajwal; Orlandi, Gian Luca; Ischebeck, Rasmus

    2012-10-01

    The SwissFEL is an X-Ray (0.1nm-7nm) Free Electron Laser user facility which is being planned for the Paul Scherrer Institute in Switzerland. At the SwissFEL, view screens will be used to monitor the transverse profile of the electron beam. Wire scanners are also to be employed as the high beam densities of the electron beam will hamper the standard diagnostics. Wire scanners will be tested on the 250MeV SwissFEL Injector Test Facility with a 200pC electron beam whose transverse diameter is typically about 100 μm. The portion of the electron beam that is unscattered from the wire will be measured to determine the beam loss. The wire scanner is driven by a stepper motor and the wire position is obtained using a digital encoder. The wire scanner may be susceptible to vibrations which may lead to erroneous encoder positions. The variation in position of the wire, with the motor being driven at a number of different speeds, was studied using a concentrator back-light and a 1MPixel high speed camera. The camera was triggered using the 10Hz SwissFEL Injector Test Facility timing signal. A typical vibration with an amplitude of about 0.5μm was observed. Dependence of vibration of the wire on the motor driving speed and ways of optimizing the operational parameters.

  16. Turbulence measurements in a swirling confined jet flowfield using a triple hot-wire probe

    Science.gov (United States)

    Janjua, S. I.; Mclaughlin, D. K.

    1982-01-01

    An axisymmetric swirling confined jet flowfield, similar to that encountered in gas turbine combustors was investigated using a triple hot-wire probe. The raw data from the three sensors were digitized using ADC's and stored on a Tektronix 4051 computer. The data were further reduced on the computer to obtain time-series for the three instantaneous velocity components in the flowfield. The time-mean velocities and the turbulence quantities were deduced. Qualification experiments were performed and where possible results compared with independent measurements. The major qualification experiments involved measurements performed in a non-swirling flow compared with conventional X-wire measurements. In the swirling flowfield, advantages of the triple wire technique over the previously used multi-position single hot-wire method are noted. The measurements obtained provide a data base with which the predictions of turbulence models in a recirculating swirling flowfield can be evaluated.

  17. Experimental investigation of near-wall effects on hot-wire measurements

    Energy Technology Data Exchange (ETDEWEB)

    Durst, F.; Zanoun, E.S. [Institute of Fluid Mechanics, Friedrich-Alexander-University, Erlangen-Nuernberg Cauerstr. 4, 91058 Erlangen (Germany)

    2002-07-01

    Hot-wire anemometry is a well-established measuring technique in modern fluid mechanics and is widely used to study laminar and turbulent flows. However, unsolved problems still exist when measurements are carried out close to heat-conducting or heat-insulating walls. Additional heat losses occur because of the presence of the wall that are usually not accounted for in the calibration of the wire. Because of this, erroneous fluid velocity measurements result with hot wires if the presence of the wall is not taken into account. The present paper investigates the effect that the wall material has on these additional heat losses from hot wires for walls of different heat conductivities. Similarity analysis of various aspects of the problem, verified by experimental and numerical results, is presented for wall materials of different heat conductivities, and the results are compared with available data in the literature. The data confirm the expected increase in heat losses with increasing wall heat conductivity. For heat-insulating materials the authors' results show that a wall-thickness influence exists. Additional data are provided to show that the heat loss from hot wires increases with increasing wire overheating, and the influence of the wire diameter is also clarified. (orig.)

  18. Characteristics of the wire biconical antenna used for EMC measurements

    Science.gov (United States)

    Austin, Brian A.; Fourie, Andre P. C.

    1991-08-01

    The characteristics of a wire biconical antenna that determine its antenna factor were computed by using the method of moments code NEC-2. A fairly extensive validation exercise was conducted from which a suitable computer model was derived. The input impedance, gain, and radiation patterns of the antenna were computed for special cases where the biconical antenna is used above a conducting ground plane for open-field EMC (electromagnetic compatibility) testing. The effects of height above the ground plane and polarization of the antenna on these parameters were found and the antenna factor was corrected for them. The current distribution along the antenna elements was also examined, and it was found that significant pattern distortion can occur at some frequencies when a horizontal wire biconical antenna is used close to the ground. These results will allow this broadband antenna to be used with confidence in applications where previously only resonant dipoles were specified.

  19. Application of Hot-wire Method for Measuring Thermal Conductivity of Fine Ceramics

    Directory of Open Access Journals (Sweden)

    Shangxi WANG

    2016-11-01

    Full Text Available Ceramic substrate is preferred in high density packaging due to its high electrical resistivity and moderate expansion coefficient. The thermal conductivity is a key parameter for packaging substrates. There are two common methods to measure the thermal conductivity, which are the hot-wire method and the laser-flash method. Usually, the thermal conductivities of porcelain is low and meet the measurement range of hot-wire method, and the measured value by hot-wire method has little difference with that by laser-flash method. In recent years, with the requirement of high-powered LED lighting, some kinds of ceramic substrates with good thermal conductivity have been developed and their thermal conductivity always measured by the means of laser flash method, which needs expensive instrument. In this paper, in order to detect the thermal conductivity of fine ceramic with convenience and low cost, the feasibility of replacing the laser flash method with hot wire method to measure thermal conductivity of ceramic composites was studied. The experiment results showed that the thermal conductivity value of fine ceramics measured by the hot-wire method is severely lower than that by the laser-flash method. However, there is a positive relationship between them. It is possible to measure the thermal conductivity of fine ceramic workpiece instantly by hot-wire method via a correction formula.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.12543

  20. Precise, contactless measurements of the surface tension of picolitre aerosol droplets.

    Science.gov (United States)

    Bzdek, Bryan R; Power, Rory M; Simpson, Stephen H; Reid, Jonathan P; Royall, C Patrick

    2016-01-01

    The surface composition and surface tension of aqueous droplets can influence key aerosol characteristics and processes including the critical supersaturation required for activation to form cloud droplets in the atmosphere. Despite its fundamental importance, surface tension measurements on droplets represent a considerable challenge owing to their small volumes. In this work, we utilize holographic optical tweezers to study the damped surface oscillations of a suspended droplet (surface tension and viscosity of droplets containing only 1-4 pL of material. An advantage of performing the measurement in aerosol is that supersaturated solute states (common in atmospheric aerosol) may be accessed. For pairs of droplets starting at their equilibrium surface composition, surface tensions and viscosities are consistent with bulk equilibrium values, indicating that droplet surfaces respond to changes in surface area on microsecond timescales and suggesting that equilibrium values can be assumed for growing atmospheric droplets. Furthermore, droplet surfaces are shown to be rapidly modified by trace species thereby altering their surface tension. This equilibration of droplet surface tension to the local environmental conditions is illustrated for unknown contaminants in laboratory air and also for droplets exposed to gas passing through a water-ethanol solution. This approach enables precise measurements of surface tension and viscosity over long time periods, properties that currently are poorly constrained.

  1. Use of the pendant drop method to measure interfacial tension between molten polymers

    Directory of Open Access Journals (Sweden)

    Emerson Y. Arashiro

    1999-01-01

    Full Text Available In this paper the pendant drop method to measure interfacial tension between molten polymers is reviewed. A typical pendant drop apparatus is presented. The algorithms used to infer interfacial tension from the geometrical profile of the pendant drop are described in details, in particular a new routine to evaluate correctly the value of the radius at the apex of the drop, necessary to the calculation of interfacial tension is presented. The method was evaluated for the possibility of measuring the interfacial tension between polyethylene and polystyrene. It is shown that the method is unsuitable for the measurement of interfacial tension between high density polyethylene and polystyrene due possibly to a too small difference of density between the two polymers. Values of interfacial tension between low density polyethylene (LDPE and polystyrene (PS as a function of the molecular weight of PS are presented. It was shown that the interfacial tension between LDPE and PS increased as a function of molecular weight of PS up to values of molecular weight of roughly 40,000 g/mol, value for which entanglements occur.

  2. Precision Mass Property Measurements Using a Five-Wire Torsion Pendulum

    Science.gov (United States)

    Swank, Aaron J.

    2012-01-01

    A method for measuring the moment of inertia of an object using a five-wire torsion pendulum design is described here. Typical moment of inertia measurement devices are capable of 1 part in 10(exp 3) accuracy and current state of the art techniques have capabilities of about one part in 10(exp 4). The five-wire apparatus design shows the prospect of improving on current state of the art. Current measurements using a laboratory prototype indicate a moment of inertia measurement precision better than a part in 10(exp 4). In addition, the apparatus is shown to be capable of measuring the mass center offset from the geometric center. Typical mass center measurement devices exhibit a measurement precision up to approximately 1 micrometer. Although the five-wire pendulum was not originally designed for mass center measurements, preliminary results indicate an apparatus with a similar design may have the potential of achieving state of the art precision.

  3. Measurement and monitoring of electrocardiogram belt tension in premature infants for assessment of respiratory function

    Directory of Open Access Journals (Sweden)

    Hegyi Thomas

    2007-04-01

    Full Text Available Abstract Background Monitoring of the electrocardiogram (ECG in premature infants with conventional adhesive-backed electrodes can harm their sensitive skin. Use of an electrode belt prevents skin irritation, but the effect of belt pressure on respiratory function is unknown. A strain gauge sensor is described which measures applied belt tension. Method The device frame was comprised of an aluminum housing and slide to minimize the device weight. Velcro tabs connected housing and slide to opposite tabs located at the electrode belt ends. The slide was connected to a leaf spring, to which were bonded two piezoresistive transducers in a half-bridge circuit configuration. The device was tested for linearity and calibrated. The effect on infant respiratory function of constant belt tension in the normal range (30 g–90 g was determined. Results The mechanical response to a step input was second order (fn = 401 Hz, ζ = 0.08. The relationship between applied tension and output voltage was linear in the range 25–225 gm of applied tension (r2 = 0.99. Measured device sensitivity was 2.18 mV/gm tension using a 5 V bridge excitation voltage. When belt tension was increased in the normal range from 30 gm to 90 gm, there was no significant change in heart rate and most respiratory functions during monitoring. At an intermediate level of tension of 50 gm, pulmonary resistance and work of breathing significantly decreased. Conclusion The mechanical and electrical design of a device for monitoring electrocardiogram electrode belt tension is described. Within the typical range of application tension, cardiovascular and respiratory function are not substantially negatively affected by electrode belt force.

  4. Measurement of the Local Tension of Red Blood Cell Membranes by Atomic Force Spectroscopy

    Directory of Open Access Journals (Sweden)

    V. A. Sergunova

    2013-01-01

    Full Text Available Objective: to study the average local tension of a membrane upon exposure to its modifiers. Materials and methods. Blood from 3 healthy donors was sampled into ethylene diamine tetraacetate-containing microvettes (Sarstedt AG and Co., Germany during prophylactic examinations. In this series of experiments, the red blood cells were exposed to the membrane nanosurface modifier hemin (muriatic hematin. Hemin disrupts the conformation of spectrin, a band 4.1 protein, and weakens their bond [19]. Hemin was added to blood in vitro. Its blood concentration was 1.8 mM. The images of cells and their membranes were obtained on a NTEGRA Prima atomic force microscope (NT-MDT, Russia [16]. The membrane tension was estimated by atomic force spectroscopy. Results. After exposure to hemin, 68% of cases showed a 2.1-fold increase in the average tension as compared to the mean control value (p<0.05, which could reduce ID by «30 %. Subsequent exposure to perftoran returned the membrane tension to the baseline values in 85% of cases. The membrane tension of other 15% of the areas on the cells remained high — 2.3 times higher than the control values (p<0.05 even despite the action of perftoran. Conclusion. Thus, atomic force spectroscopy was used to measure the average local tension of the membrane, which depended on exposure to its modifiers, such as hemin. Key words: red blood cell, membrane tension, atomic force spectroscopy, hemin.

  5. A Steel Wire Stress Measuring Sensor Based on the Static Magnetization by Permanent Magnets

    Directory of Open Access Journals (Sweden)

    Dongge Deng

    2016-10-01

    Full Text Available A new stress measuring sensor is proposed to evaluate the axial stress in steel wires. Without using excitation and induction coils, the sensor mainly consists of a static magnetization unit made of permanent magnets and a magnetic field measurement unit containing Hall element arrays. Firstly, the principle is illustrated in detail. Under the excitation of the magnetization unit, a spatially varying magnetized region in the steel wire is utilized as the measurement region. Radial and axial magnetic flux densities at different lift-offs in this region are measured by the measurement unit to calculate the differential permeability curve and magnetization curve. Feature parameters extracted from the curves are used to evaluate the axial stress. Secondly, the special stress sensor for Φ5 and Φ7 steel wires is developed accordingly. At last, the performance of the sensor is tested experimentally. Experimental results show that the sensor can measure the magnetization curve accurately with the error in the range of ±6%. Furthermore, the obtained differential permeability at working points 1200 A/m and 10000 A/m change almost linearly with the stress in steel wires, the goodness of linear fits are all higher than 0.987. Thus, the proposed steel wire stress measuring sensor is feasible.

  6. A biomechanical comparison of the Rogers interspinous and the Lovely-Carl tension band wiring techniques for fixation of the cervical spine.

    Science.gov (United States)

    Brasil, A V; Coehlo, D G; Filho, T E; Braga, F M

    2000-07-01

    The authors conducted a biomechanical study in which they compared the uses of the Rogers interspinous and the Lovely-Carl tension band wiring techniques for internal fixation of the cervical spine. An extensive biomechanical evaluation (stiffness in positive and negative rotations around the x, y, and z axes; range of motion in flexion-extension, bilateral axial rotation, and bilateral bending; and neutral zone in flexion-extension, bilateral axial rotation, and lateral bending to the right and to the left) was performed in two groups of intact calf cervical spines. After these initial tests, all specimens were subjected to a distractive flexion Stage 3 ligamentous lesion. Group 1 specimens then underwent surgical fixation by the Rogers technique, and Group 2 specimens underwent surgery by using the Lovely-Carl technique. After fixation, specimens were again submitted to the same biomechanical evaluation. The percentage increase or decrease between the pre- and postoperative parameters was calculated. These values were considered quantitative indicators of the efficacy of the techniques, and the efficacy of the two techniques was compared. Analysis of the findings demonstrated that in the spines treated with the Lovely-Carl technique less restriction of movement was produced without affecting stiffness, compared with those treated with the Rogers technique, thus making the Lovely-Carl technique clinically less useful.

  7. Mixed and dynamic response of hot wires and cold wires and measurements of turbulence statistics

    DEFF Research Database (Denmark)

    Larsen, Søren Ejling; Højstrup, Jørgen; Fairall, C. W.

    1986-01-01

    . The influence of the transfer characteristics on measurements of turbulence statistics is discussed; it is shown that the nonideal response behavior influences, most strongly, statistics involving the correlation between velocity and temperature and, most seriously, parameters involving small-scale turbulence...

  8. Some remarks on the solid surface tension determination from contact angle measurements

    Energy Technology Data Exchange (ETDEWEB)

    Zdziennicka, Anna; Szymczyk, Katarzyna; Krawczyk, Joanna; Jańczuk, Bronisław, E-mail: bronislaw.janczuk@poczta.umcs.lublin.pl

    2017-05-31

    Graphical abstract: Surface tension of PE, nylon 6 and quartz from different approaches to the interface tension. - Highlights: • New values of water and formamide surface tension components were established. • Quartz surface tension depends on its crystal face. • Usefulness of different approaches for solid surface tension determination was tested. - Abstract: The measurements of water, formamide and diiodomethane contact angle (θ) on polytetrafluoroethylene (PTFE), polyethylene (PE), polymethyl methacrylate (PMMA), nylon 6, quartz and silica were performed. Based on the θ values of these liquids obtained on PTFE, the Lifshitz-van der Waals and acid-base and/or dispersion and polar components of their surface tension (ST) were determined. In turn, the θ values for water, formamide and diiodomethane on PMMA were applied to calculate the electron-acceptor and electron-donor parameters of the Lewis acid-base component of the formamide ST. For this calculation the same values of the electron-acceptor and electron-donor parameters for water ST were used. Taking into account the values of components and parameters of water, formamide and diiodomethane ST obtained by us, van Oss et al. and from the water(formamide)-n-alkane and water-diiodomethane interface tension, the components and parameters of studied solids ST were calculated. To this end different approaches to the interface tension were considered. The obtained values were compared with those in the literature. It was concluded that for determination of solid ST components and parameters, those of water, formamide and diiodomethane ST obtained from the θ measurements on the model solids should be used.

  9. A fast wire scanner, used to measure the transverse density distribution of beams circulating in an accelerator or storage ring.

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    Fast wire scanners are used to measure the transverse density distribution of beams circulating in an accelerator or storage ring. In order to minimize blow-up of the beam through multiple Coulomb scattering, the wires are very thin (in the version shown here it is actually a twisted strand of carbon fibres with a total diameter of about 25 microns) and are swept through the beam at high speed (a linear motor, not mounted here, accelerates the wires to up to 20 m/s). One measures either the secondary emission current from the wire, or the signal from a scintillator/photomultiplier combination downstream from the wire scanner receiving the shower from nuclear reactions of beam particles with the wire nuclei. There are four such fast wire scanners in the 26 GeV PS and eight in the 1.4 GeV Booster.

  10. Hydrophobicity, surface tension, and zeta potential measurements of glass-reinforced hydroxyapatite composites.

    Science.gov (United States)

    Lopes, M A; Monteiro, F J; Santos, J D; Serro, A P; Saramago, B

    1999-06-15

    Wettability and zeta potential studies were performed to characterize the hydrophobicity, surface tension, and surface charge of P2O5-glass-reinforced hydroxyapatite composites. Quantitative phase analysis was performed by the Rietveld method using GSAS software applied to X-ray diffractograms. Surface charge was assessed by zeta potential measurements. Protein adsorption studies were performed using vitronectin. Contact angles and surface tensions variation with time were determined by the sessile and pendent drop techniques, respectively, using ADSA-P software. The highest (-18.1 mV) and lowest (-28.7 mV) values of zeta potential were found for hydroxyapatite (HA) and beta-tricalcium phosphate (beta-TCP), respectively, with composite materials presenting values in between. All studied bioceramic materials showed similar solid surface tension. For HA and beta-TCP, solid surface tensions of 46.7 and 45.3 mJ/m2, respectively, were obtained, while composites presented intermediate surface tension values. The dispersive component of surface tension was the predominant one for all materials studied. Adhesion work values between the vitronectin solution and HA and beta-TCP were found to be 79.8 and 88.0 mJ/m2, respectively, while the 4.0 wt % glass composites showed slightly lower values than the 2.5 wt % ones. The presence of beta-TCP influenced surface charge, hydrophobicity, and protein adsorption of the glass-reinforced HA composites, and therefore indirectly affected cell-biomaterial interactions.

  11. Clinical results of treatment using a modified K-wire tension band versus a cannulated screw tension band in transverse patella fractures: A strobe-compliant retrospective observational study.

    Science.gov (United States)

    Tan, Honglue; Dai, Pengyi; Yuan, Yanhao

    2016-10-01

    It was a retrospective case-control study. The aim of this study was to explore the clinical efficacy and complication of treatment using a modified Kirschner wire tension band (MKTB) or a cannulated screw tension band (CSTB) in transverse patellar fractures.In total, 55 patients with transverse patellar fractures were retrospectively reviewed and divided into 2 groups according to the surgical technique: 29 patients were in the MKTB group and 26 patients in the CSTB group. B[Latin Small Letter o with Caron]stman's clinical grading scale, including range of movement (ROM), pain, ability to work, atrophy of quadriceps femoris, assistance in walking, effusion, giving way, and stair-climbing, was used to evaluate the clinical results. Complications including painful hardware, implant loosening or breakage, and bone nonunion were also assessed.Both groups were evaluated at the final follow-up before removing implant in the MKTB group. The B[Latin Small Letter o with Caron]stman's score of ROM, pain, atrophy of quadriceps femoris, and effusion were all higher in the CSTB group than in the MKTB group (P  0.05). Seventeen patients achieved excellent results, 9 had good results, and 3 reported fair results in the MKTB group; the CSTB group had excellent results in 22 patients and good results in 4 patients, showing a significant difference in the excellent rate between the 2 groups (P = 0.021). Total B[Latin Small Letter o with Caron]stman scores in the MKTB and CSTB groups (26.96 ± 4.47 and 29.42 ± 1.47, respectively) were significantly different (P = 0.01). Total scores in the MKTB group after removing implant were higher than those before removing implant (P = 0.001), and similar to those in the CSTB group (P = 0.224). Eleven patients in the MKTB group reported painful hardware, including 4 cases of implant loosening.CSTB achieves better clinical results than MKTB, meanwhile avoiding the problems of painful hardware and implant loosening

  12. Direct Surface Tension Measurements of Individual Sub-Micrometer Particles Using Atomic Force Microscopy.

    Science.gov (United States)

    Lee, Hansol D; Estillore, Armando D; Morris, Holly S; Ray, Kamal K; Alejandro, Aldair; Grassian, Vicki H; Tivanski, Alexei V

    2017-11-02

    Understanding the role of sea spray aerosol (SSA) on climate and the environment is of great interest due to their high number concentration throughout the Earth's atmosphere. Despite being of fundamental importance, direct surface tension measurements of SSA relevant sub-micrometer particles are rare, largely due to their extremely small volumes. Herein, atomic force microscopy (AFM) is used to directly measure the surface tension of individual sub-micrometer SSA particle mimics at ambient temperature and varying relative humidity (RH). Specifically, we probed both atmospherically relevant and fundamentally important model systems including electrolyte salts, dicarboxylic acids, and saccharides as single components and mixtures. Our results show that the single particle surface tension depends on RH or solute mole percentage and chemical composition. Moreover, for liquid droplets at and below 100 Pa s in viscosity, or at corresponding RH, we show good agreement between the AFM single particle and the bulk solution surface tension measurements at overlapping concentration ranges. Thus, direct surface tension measurements of individual particles using AFM is shown over a wide range of chemical systems as a function of RH, solute mole percentage, and viscosity than previously reported.

  13. Design of an experimental apparatus for measurement of the surface tension of metastable fluids

    Directory of Open Access Journals (Sweden)

    Blaha J.

    2013-04-01

    Full Text Available A unique experimental apparatus for measurement of the surface tension of aqueous mixtures has been designed, manufactured, and tested in our laboratory. The novelty of the setup is that it allows measurement of surface tension by two different methods: a modified capillary elevation method in a long vertical capillary tube and a method inspired by the approach of Hacker (National Advisory Committee for Aeronautics, Technical Note 2510, 1-20, 1951, i.e. in a short horizontal capillary tube. Functionality of all main components of the apparatus, e.g., glass chamber with the capillary tube, temperature control unit consisting of two thermostatic baths with special valves for rapid temperature jumps, helium distribution setup allowing pressure variation above the liquid meniscus inside the capillary tube, has been successfully tested. Preliminary results for the surface tension of the stable and metastable supercooled water measured by the capillary elevation method at atmospheric pressure are provided. The surface tension of water measured at temperatures between +26 °C and –11 °C is in good agreement with the extrapolated IAPWS correlation (IAPWS Release on Surface Tension of Ordinary Water Substance, September 1994; however it disagrees with data by Hacker.

  14. On-chip microfluidic generation of monodisperse bubbles for liquid interfacial tension measurement.

    Science.gov (United States)

    Wang, Chen; Cao, Jing; Zhou, Yue; Xia, Xing-Hua

    2018-01-01

    A novel microfluidic method for measuring liquid interfacial tension using monodisperse microbubbles generated in situ has been proposed. Instead of bulky gas supply used in traditional microfluidic devices, microbubbles are efficiently generated via water electrolysis in the devices. Since the bubble formation frequency is related to the interfacial tension of liquids used, thus, precisely measuring the interfacial tension of liquids in microfluidics can be achieved. In addition, it is found that during the microbubble formation, the electrochemical potential fluctuates regularly at controlled electrolysis current, and the fluctuating period depends on the microbubble generation rate. Therefore, the change in electrochemical potential can be directly used to monitor the bubble formation process, which avoids the use of an external optical detection system. As demonstration, the interfacial tension of isopentanol solutions with different concentrations was measured, and the results show good agreement with the ones obtained using the maximum bubble pressure method, confirming the accuracy of the present method. The proposed strategy offers a simple, low cost and accurate solution to measure the liquid interfacial tension confined in microfluidic channels. The present platform is easily constructed and facilely manipulated in common laboratories, which is expected to be widely used in microfluidic-based research and application fields. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Design of an experimental apparatus for measurement of the surface tension of metastable fluids

    Science.gov (United States)

    Vinš, V.; Hrubý, J.; Hykl, J.; Blaha, J.; Šmíd, B.

    2013-04-01

    A unique experimental apparatus for measurement of the surface tension of aqueous mixtures has been designed, manufactured, and tested in our laboratory. The novelty of the setup is that it allows measurement of surface tension by two different methods: a modified capillary elevation method in a long vertical capillary tube and a method inspired by the approach of Hacker (National Advisory Committee for Aeronautics, Technical Note 2510, 1-20, 1951), i.e. in a short horizontal capillary tube. Functionality of all main components of the apparatus, e.g., glass chamber with the capillary tube, temperature control unit consisting of two thermostatic baths with special valves for rapid temperature jumps, helium distribution setup allowing pressure variation above the liquid meniscus inside the capillary tube, has been successfully tested. Preliminary results for the surface tension of the stable and metastable supercooled water measured by the capillary elevation method at atmospheric pressure are provided. The surface tension of water measured at temperatures between +26 °C and -11 °C is in good agreement with the extrapolated IAPWS correlation (IAPWS Release on Surface Tension of Ordinary Water Substance, September 1994); however it disagrees with data by Hacker.

  16. Measurement of 3-axis magnetic fields induced by current wires using a smartphone in magnetostatics experiments

    Science.gov (United States)

    Setiawan, B.; Septianto, R. D.; Suhendra, D.; Iskandar, F.

    2017-11-01

    This paper describes the use of an inexpensive smartphone’s magnetic sensor to measure magnetic field components (B x , B y and B z ) induced by current wires in magnetostatic experiments. The variable parameters used to measure the magnetic sensor’s capabilities were: the geometrical shapes of the wire, current flow, and the distance between wire and observation point. The experimental results are in good agreement with the results obtained from calculations using an analytical and numerical approach. In addition, the 2D vectors and magnitude of the magnetic field have been successfully illustrated. This study confirmed that the inexpensive smartphone’s magnetic sensor had a good ability to accurately measure the components of a magnetic field in a magnetostatic experiment, which is especially suitable for undergraduate students.

  17. Uncertainties in hot-wire measurements of compressible turbulent flows implied by comparisons with laser-induced fluorescence

    Science.gov (United States)

    Mckenzie, R. L.; Logan, P.

    1986-01-01

    A hot-wire anemometer and a new nonintrusive laser-induced fluorescence (LIF) technique are used to survey a Mach 2 turbulent boundary layer. The hot-wire anemometer's ability to accurately measure mass flux, temperature, and density fluctuations in a compressible flow is examined by comparing its results with those obtained using LIF. Several methods of hot-wire calibration are used, and the uncertainties in their measurements of various fluctuating flow parameters are determined. The results show that although a hot-wire operated at high overheat can measure mass flux fluctuations, temperature and density fluctuations are not determined accurately from such measurements. However, a hot-wire operated at multiple overheats can be used to measure static and total temperature fluctuations. The presence of pressure fluctuations and their correlation with density can prevent the use of hot-wire data to determine density fluctuations.

  18. Oscillating drop/bubble tensiometry: effect of viscous forces on the measurement of interfacial tension.

    Science.gov (United States)

    Freer, E M; Wong, H; Radke, C J

    2005-02-01

    The oscillating drop/bubble technique is increasingly popular for measuring the interfacial dilatational properties of surfactant/polymer-laden fluid/fluid interfaces. A caveat of this technique, however, is that viscous forces are important at higher oscillation frequencies or fluid viscosities; these can affect determination of the interfacial tension. Here, we experimentally quantify the effect of viscous forces on the interfacial-tension measurement by oscillating 100 and 200 cSt poly(dimethylsiloxane) (PDMS) droplets in water at small amplitudes and frequencies ranging between 0.01 and 1 Hz. Due to viscous forces, the measured interfacial tension oscillates sinusoidally with the same frequency as the oscillation of the drop volume. The tension oscillation precedes that of the drop volume, and the amplitude varies linearly with Capillary number, Ca=DeltamuomegaDeltaV/gammaa(2), where Deltamu=mu(D)-mu is the difference between the bulk Newtonian viscosities of the drop and surrounding continuous fluid, omega is the oscillation frequency of the drop, DeltaV is the amplitude of volume oscillation, gamma is the equilibrium interfacial tension between the PDMS drop and water, and a is the radius of the capillary. A simplified model of a freely suspended spherical oscillating-drop well explains these observations. Viscous forces distort the drop shape at Ca>0.002, although this criterion is apparatus dependent.

  19. Measurement and Modeling of Surface Tensions of Asymmetric Systems: Heptane, Eicosane, Docosane, Tetracosane and their Mixtures

    DEFF Research Database (Denmark)

    Queimada, Antonio; Silva, Filipa A. E.; Caco, Ana I.

    2003-01-01

    To extend the surface tension database for heavy or asymmetric n-alkane mixtures, measurements were performed using the Wilhelmy plate method. Measured systems included the binary mixtures heptane + eicosane, heptane + docosane and heptane + tetracosane and the ternary mixture heptane + eicosane...

  20. Measurement and Modeling of Surface Tensions of Asymmetric Systems: Heptane, Eicosane, Docosane, Tetracosane and their Mixtures

    DEFF Research Database (Denmark)

    Queimada, Antonio; Silva, Filipa A.E; Caco, Ana I.

    2003-01-01

    To extend the surface tension database for heavy or asymmetric n-alkane mixtures, measurements were performed using the Wilhelmy plate method. Measured systems included the binary mixtures heptane + eicosane, heptane + docosane and heptane + tetracosane and the ternary mixture heptane + eicosane ...

  1. Direct Measurement of the Electron Energy Relaxation Dynamics in Metallic Wires

    Science.gov (United States)

    Pinsolle, Edouard; Rousseau, Alexandre; Lupien, Christian; Reulet, Bertrand

    2016-06-01

    We present measurements of the dynamical response of thermal noise to an ac excitation in conductors at low temperature. From the frequency dependence of this response function—the (noise) thermal impedance—in the range 1 kHz-1 GHz we obtain direct determinations of the inelastic relaxation times relevant in metallic wires at low temperature: the electron-phonon scattering time and the diffusion time of electrons along the wires. Combining these results with that of resistivity provides a measurement of heat capacity of samples made of thin film. The simplicity and reliability of this technique makes it very promising for future applications in other systems.

  2. Inductive method to measure very small joint resistances of superconducting wires

    CERN Document Server

    Herzog, R

    1998-01-01

    In the Large Hadron Collider (LHC), which is currently being developed at CERN, about 50,000 connections of superconducting wire will be necessary to implement all circuits for powering 6000 corrector magnets with a maximum current of 600 A. To minimise the generation of ohmic heat in the cryogenic system, it is necessary to reduce the contact resistance of these connections as much as possible. This paper describes a method to measure contact resistances of splices of superconducting wires, which has been used to optimise such connections. Additionally we present results of a number of measurements on different types of connections. (2 refs).

  3. Simultaneous measurement of surface tension and viscosity using freely decaying oscillations of acoustically levitated droplets

    Science.gov (United States)

    Kremer, J.; Kilzer, A.; Petermann, M.

    2018-01-01

    Oscillations of small liquid drops around a spherical shape have been of great interest to scientists measuring physical properties such as interfacial tension and viscosity, over the last few decades. A powerful tool for contactless positioning is acoustic levitation, which has been used to simultaneously determine the surface tension and viscosity of liquids at ambient pressure. In order to extend this acoustic levitation measurement method to high pressure systems, the method is first evaluated under ambient pressure. To measure surface tension and viscosity using acoustically levitated oscillating drops, an image analysis method has to be developed and factors which may affect measurement, such as sound field or oscillation amplitude, have to be analyzed. In this paper, we describe the simultaneous measurement of surface tension and viscosity using freely decaying shape oscillations of acoustically levitated droplets of different liquids (silicone oils AK 5 and AK 10, squalane, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, and 1-octanol) in air. These liquids vary in viscosity from 2 to about 30 mPa s. An acoustic levitation system, including an optimized standing wave acoustic levitator and a high-speed camera, was used for this study. An image analysis was performed with a self-written Matlab® code. The frequency of oscillation and the damping constant, required for the determination of surface tension and viscosity, respectively, were calculated from the evolution of the equatorial and polar radii. The results and observations are compared to data from the literature in order to analyze the accuracy of surface tension and viscosity determination, as well as the effect of non-spherical drop shape or amplitude of oscillation on measurement.

  4. Simultaneous measurement of surface tension and viscosity using freely decaying oscillations of acoustically levitated droplets.

    Science.gov (United States)

    Kremer, J; Kilzer, A; Petermann, M

    2018-01-01

    Oscillations of small liquid drops around a spherical shape have been of great interest to scientists measuring physical properties such as interfacial tension and viscosity, over the last few decades. A powerful tool for contactless positioning is acoustic levitation, which has been used to simultaneously determine the surface tension and viscosity of liquids at ambient pressure. In order to extend this acoustic levitation measurement method to high pressure systems, the method is first evaluated under ambient pressure. To measure surface tension and viscosity using acoustically levitated oscillating drops, an image analysis method has to be developed and factors which may affect measurement, such as sound field or oscillation amplitude, have to be analyzed. In this paper, we describe the simultaneous measurement of surface tension and viscosity using freely decaying shape oscillations of acoustically levitated droplets of different liquids (silicone oils AK 5 and AK 10, squalane, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, and 1-octanol) in air. These liquids vary in viscosity from 2 to about 30 mPa s. An acoustic levitation system, including an optimized standing wave acoustic levitator and a high-speed camera, was used for this study. An image analysis was performed with a self-written Matlab® code. The frequency of oscillation and the damping constant, required for the determination of surface tension and viscosity, respectively, were calculated from the evolution of the equatorial and polar radii. The results and observations are compared to data from the literature in order to analyze the accuracy of surface tension and viscosity determination, as well as the effect of non-spherical drop shape or amplitude of oscillation on measurement.

  5. An electromagnetic micrometer to measure the wire centering in high- resolution aluminium drift tubes

    CERN Document Server

    Cambiaghi, M; Casani, S; Ferrari, R; Gaudio, G; Iuvino, G; Lanza, A; Prata, M J

    1999-01-01

    The muon detector of the Atlas experiment at LHC (CERN) consists of 370000 high-resolution drift tubes assembled in multi-layer chambers. To take full advantage of the single-tube resolution, the high- precision external surface of tube end-plugs is used for positioning a layer before gluing. The wire position in the tube is defined at construction time by means of a locator inserted in the end-plug. To check that the wire is in the nominal position after the tube assembly an electromagnetic micrometer (EMMI) has been developed. EMMI detects the wire position by measuring the electromotive force induced in two sensors symmetrically placed on both sides of the tube when a small sinusoidal current circulates on the wire. An accuracy of two microns on the wire centering has been obtained. The simplicity of this method and the short measuring time allow every drift tube to be checked, thus guaranteeing the precision requested for the Atlas muon detector. (4 refs).

  6. An electromagnetic micrometer to measure the wire centering in high-resolution aluminium drift tubes

    CERN Document Server

    Cambiaghi, M; Casani, S; Ferrari, R; Gaudio, G; Iuvino, G; Lanza, A; Prata, M J

    1999-01-01

    The muon detector of the Atlas experiment at LHC (CERN) consists of 370000 high-resolution drift tubes assembled in multi-layer chambers. To take full advantage of the single-tube resolution, the high- precision external surface of tube end-plugs is used for positioning a layer before gluing. The wire position in the tube is defined at construction time by means of a locator inserted in the end-plug. To check that the wire is in the nominal position after the tube assembly an electromagnetic micrometer (EMMI) has been developed. EMMI detects the wire position by measuring the electromotive force induced in two sensors symmetrically placed on both sides of the tube when a small sinusoidal current circulates on the wire. An accuracy of two microns on the wire centering has been obtained. The simplicity of this method and the short measuring time allow every drift tube to be checked, thus guaranteeing the precision requested for the Atlas muon detector. (4 refs).

  7. Societal costs in displaced transverse olecranon fractures: using decision analysis tools to find the most cost-effective strategy between tension band wiring and locked plating.

    Science.gov (United States)

    Francis, Tittu; Washington, Travis; Srivastava, Karan; Moutzouros, Vasilios; Makhni, Eric C; Hakeos, William

    2017-11-01

    Tension band wiring (TBW) and locked plating are common treatment options for Mayo IIA olecranon fractures. Clinical trials have shown excellent functional outcomes with both techniques. Although TBW implants are significantly less expensive than a locked olecranon plate, TBW often requires an additional operation for implant removal. To choose the most cost-effective treatment strategy, surgeons must understand how implant costs and return to the operating room influence the most cost-effective strategy. This cost-effective analysis study explored the optimal treatment strategies by using decision analysis tools. An expected-value decision tree was constructed to estimate costs based on the 2 implant choices. Values for critical variables, such as implant removal rate, were obtained from the literature. A Monte Carlo simulation consisting of 100,000 trials was used to incorporate variability in medical costs and implant removal rates. Sensitivity analysis and strategy tables were used to show how different variables influence the most cost-effective strategy. TBW was the most cost-effective strategy, with a cost savings of approximately $1300. TBW was also the dominant strategy by being the most cost-effective solution in 63% of the Monte Carlo trials. Sensitivity analysis identified implant costs for plate fixation and surgical costs for implant removal as the most sensitive parameters influencing the cost-effective strategy. Strategy tables showed the most cost-effective solution as 2 parameters vary simultaneously. TBW is the most cost-effective strategy in treating Mayo IIA olecranon fractures despite a higher rate of return to the operating room. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  8. Biomechanical comparison of pin and tension-band wire fixation with a prototype locking plate fixation in a transverse canine patellar fracture model.

    Science.gov (United States)

    Gibert, Sophie; Kowaleski, Michael P; Matthys, Romano; Nützi, Reto; Serck, Boris; Boudrieau, Randy J

    2016-01-01

    To compare a locking plate (LP) with pin and tension-band wire (pin/TBW) for fixation of mid-patellar transverse fractures. Cadaveric canine stifle joints from 10 adult mixed breed dogs (23-36 kg) were used. Mid-patellar transverse osteotomies were randomly stabilized (in pairs) with either pin/TBW or a prototype LP. Cyclic loads (1 Hz, 500 cycles) at 100% body weight (90°-135° stifle joint extension), were applied. Survival or failure of constructs was defined as <2 mm fracture gap distraction at 500 cycles, or ≥2 mm fracture gap distraction at the number of cycles sustained, respectively. Number of cycles at failure and distraction gap were compared with a paired Student's t-test, and a survival analysis performed with a Mantel-Cox test. All constructs that survived cyclic testing were tested in single cycle load to failure (1.0 mm/sec; 110° stifle joint extension); yield strength was compared with a Wilcoxon rank sum test. Significance was set at p <0.05. All 10/10 LP and three out of 10 pin/TBW fixations survived cyclic testing. Survival analysis, number of cycles at failure, and distraction gap all were significantly different between the two groups (p = 0.0011, p = 0.0013, and p <0.0001, respectively). Construct yield strength was not significantly different (p = 0.1273). The failure mode with pin/TBW was consistently similar to failures observed clinically. The LP demonstrated consistent, reliable and stable fixation.

  9. Accuracy of surface tension measurement from drop shapes: the role of image analysis.

    Science.gov (United States)

    Kalantarian, Ali; Saad, Sameh M I; Neumann, A Wilhelm

    2013-11-01

    Axisymmetric Drop Shape Analysis (ADSA) has been extensively used for surface tension measurement. In essence, ADSA works by matching a theoretical profile of the drop to the extracted experimental profile, taking surface tension as an adjustable parameter. Of the three main building blocks of ADSA, i.e. edge detection, the numerical integration of the Laplace equation for generating theoretical curves and the optimization procedure, only edge detection (that extracts the drop profile line from the drop image) needs extensive study. For the purpose of this article, the numerical integration of the Laplace equation for generating theoretical curves and the optimization procedure will only require a minor effort. It is the aim of this paper to investigate how far the surface tension accuracy of drop shape techniques can be pushed by fine tuning and optimizing edge detection strategies for a given drop image. Two different aspects of edge detection are pursued here: sub-pixel resolution and pixel resolution. The effect of two sub-pixel resolution strategies, i.e. spline and sigmoid, on the accuracy of surface tension measurement is investigated. It is found that the number of pixel points in the fitting procedure of the sub-pixel resolution techniques is crucial, and its value should be determined based on the contrast of the image, i.e. the gray level difference between the drop and the background. On the pixel resolution side, two suitable and reliable edge detectors, i.e. Canny and SUSAN, are explored, and the effect of user-specified parameters of the edge detector on the accuracy of surface tension measurement is scrutinized. Based on the contrast of the image, an optimum value of the user-specified parameter of the edge detector, SUSAN, is suggested. Overall, an accuracy of 0.01mJ/m(2) is achievable for the surface tension determination by careful fine tuning of edge detection algorithms. © 2013 Elsevier B.V. All rights reserved.

  10. Measuring convective heat transfer coefficients of nanofluids over a circular fine wire maintaining a constant temperature

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Shinpyo [Kyonggi Univ., Suwon (Korea, Republic of)

    2012-01-15

    This paper describes a measuring apparatus that can be used to appraise the effectiveness of nanofluids as new heat transfer enhancing fluids. A couple of apparatuses using fine hot wires as sensors have been proposed for this purpose; however, they have a technical weakness related to the uncertain working conditions of the sensor. The present method used the convective heat transfer coefficient from a hot wire as an indication of the heat transfer effectiveness of the nanofluid, where the temperature of the wire remains constant during the experiment. The operating principle and experimental procedure are explained in detail, and the validity of the system is tested with pure base fluids. The effects of particle concentration, velocity, and temperature on the heat transfer coefficients of the nanofluids are discussed comprehensively using the experimental data for graphite nanolubrication oil.

  11. Further elucidation of nanofluid thermal conductivity measurement using a transient hot-wire method apparatus

    Science.gov (United States)

    Yoo, Donghoon; Lee, Joohyun; Lee, Byeongchan; Kwon, Suyong; Koo, Junemo

    2017-08-01

    The Transient Hot-Wire Method (THWM) was developed to measure the absolute thermal conductivity of gases, liquids, melts, and solids with low uncertainty. The majority of nanofluid researchers used THWM to measure the thermal conductivity of test fluids. Several reasons have been suggested for the discrepancies in these types of measurements, including nanofluid generation, nanofluid stability, and measurement challenges. The details of the transient hot-wire method such as the test cell size, the temperature coefficient of resistance (TCR) and the sampling number are further investigated to improve the accuracy and consistency of the measurements of different researchers. It was observed that smaller test apparatuses were better because they can delay the onset of natural convection. TCR values of a coated platinum wire were measured and statistically analyzed to reduce the uncertainty in thermal conductivity measurements. For validation, ethylene glycol (EG) and water thermal conductivity were measured and analyzed in the temperature range between 280 and 310 K. Furthermore, a detailed statistical analysis was conducted for such measurements, and the results confirmed the minimum number of samples required to achieve the desired resolution and precision of the measurements. It is further proposed that researchers fully report the information related to their measurements to validate the measurements and to avoid future inconsistent nanofluid data.

  12. Further elucidation of nanofluid thermal conductivity measurement using a transient hot-wire method apparatus

    Science.gov (United States)

    Yoo, Donghoon; Lee, Joohyun; Lee, Byeongchan; Kwon, Suyong; Koo, Junemo

    2018-02-01

    The Transient Hot-Wire Method (THWM) was developed to measure the absolute thermal conductivity of gases, liquids, melts, and solids with low uncertainty. The majority of nanofluid researchers used THWM to measure the thermal conductivity of test fluids. Several reasons have been suggested for the discrepancies in these types of measurements, including nanofluid generation, nanofluid stability, and measurement challenges. The details of the transient hot-wire method such as the test cell size, the temperature coefficient of resistance (TCR) and the sampling number are further investigated to improve the accuracy and consistency of the measurements of different researchers. It was observed that smaller test apparatuses were better because they can delay the onset of natural convection. TCR values of a coated platinum wire were measured and statistically analyzed to reduce the uncertainty in thermal conductivity measurements. For validation, ethylene glycol (EG) and water thermal conductivity were measured and analyzed in the temperature range between 280 and 310 K. Furthermore, a detailed statistical analysis was conducted for such measurements, and the results confirmed the minimum number of samples required to achieve the desired resolution and precision of the measurements. It is further proposed that researchers fully report the information related to their measurements to validate the measurements and to avoid future inconsistent nanofluid data.

  13. A Hot-Wire Method Based Thermal Conductivity Measurement Apparatus for Teaching Purposes

    Science.gov (United States)

    Alvarado, S.; Marin, E.; Juarez, A. G.; Calderon, A.; Ivanov, R.

    2012-01-01

    The implementation of an automated system based on the hot-wire technique is described for the measurement of the thermal conductivity of liquids using equipment easily available in modern physics laboratories at high schools and universities (basically a precision current source and a voltage meter, a data acquisition card, a personal computer…

  14. Surface tension and viscosity of molten vanadium measured with an electrostatic levitation furnace

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Junpei T., E-mail: okada.junpei@jaxa.j [Japan Aerospace Exploration Agency, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505 (Japan); Ishikawa, Takehiko [Japan Aerospace Exploration Agency, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505 (Japan); Watanabe, Yuki [Advanced Engineering Service Co., Ltd., 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505 (Japan); Paradis, Paul-Francois [Japan Aerospace Exploration Agency, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505 (Japan)

    2010-07-15

    Surface tension and viscosity of molten vanadium were measured over a wide temperature range by the oscillating drop method in an electrostatic levitation furnace. Over the (2023 to 2517) K temperature range, the surface tension can be expressed as gamma(T)/(10{sup -3} N/m) = 1935 - 0.27 left brace(T - T{sub m})/Kright brace with T{sub m} = 2183 K. Over the same temperature span, the viscosity can be expressed as eta(T)/(10{sup -3} Pa . s) = 1.23exp[2.27 . 10{sup 4}/(RTK{sup -1})], where R is the gas constant.

  15. Measurement of the interfacial tension of demixed colloid-polymer suspensions

    NARCIS (Netherlands)

    Lekkerkerker, H.N.W.; Vliegenthart, G.A.

    1997-01-01

    The interfacial tension of a demixed colloid-polymer mixture is measured using the spinning drop technique. For a demixed system of colloidal silica (diameter 20 nm) and polydimethylsiloxane ((Mw = 97000) in cyclohexane a value of 1.5 x 10-2 mN/m is obtained.

  16. Measurements of Flow Mixing at Subchannels in a Wire-Wrapped 61-Rod Bundle for a Sodium Cooled Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Won; Kim, Hyungmo; Ko, Yung Joo; Choi, Hae Seob; Euh, Dong-Jin; Jeong, Ji-Young; Lee, Hyeong-Yeon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    For a safety analysis in a core thermal design of a sodium-cooled fast reactor (SFR), flow mixing characteristics at subchannels in a wire-wrapped rod bundle are crucial factor for the design code verification and validation. Wrapped wires make a cross flow in a circumference of the fuel rod, and this effect lets flow be mixed. Therefore the sub-channel analysis method is commonly used for thermal hydraulic analysis of a SFR, a wire wrapped sub-channel type. To measure flow mixing characteristics, a wire mesh sensing technique can be useful method. A wire mesh sensor has been traditionally used to measure the void fraction of a two-phase flow field, i.e. gas and liquid. However, the recent reports that the wire mesh sensor can be used successfully to recognize the flow field in liquid phase by injecting a tracing liquid with a different level of electric conductivity. The subchannel flow characteristics analysis method is commonly used for the thermal hydraulic analysis of a SFR, a wire wrapped subchannel type. In this study, mixing experiments were conducted successfully at a hexagonally arrayed 61-pin wire-wrapped fuel rod bundle test section. Wire mesh sensor was used to measure flow mixing characteristics. The developed post-processing method has its own merits, and flow mixing results were reasonable.

  17. Development of Maximum Bubble Pressure Method for Surface Tension Measurement of High Viscosity Molten Silicate

    Science.gov (United States)

    Takeda, Osamu; Iwamoto, Hirone; Sakashita, Ryota; Iseki, Chiaki; Zhu, Hongmin

    2017-07-01

    A surface tension measurement method based on the maximum bubble pressure (MBP) method was developed in order to precisely determine the surface tension of molten silicates in this study. Specifically, the influence of viscosity on surface tension measurements was quantified, and the criteria for accurate measurement were investigated. It was found that the MBP apparently increased with an increase in viscosity. This was because extra pressure was required for the flowing liquid inside the capillary due to viscous resistance. It was also expected that the extra pressure would decrease by decreasing the fluid velocity. For silicone oil with a viscosity of 1000 \\hbox {mPa}{\\cdot }\\hbox {s}, the error on the MBP could be decreased to +1.7 % by increasing the bubble detachment time to 300 \\hbox {s}. However, the error was still over 1 % even when the bubble detachment time was increased to 600 \\hbox {s}. Therefore, a true value of the MBP was determined by using a curve-fitting technique with a simple relaxation function, and that was succeeded for silicone oil at 1000 \\hbox {mPa}{\\cdot } \\hbox {s} of viscosity. Furthermore, for silicone oil with a viscosity as high as 10 000 \\hbox {mPa}{\\cdot }\\hbox {s}, the apparent MBP approached a true value by interrupting the gas introduction during the pressure rising period and by re-introducing the gas at a slow flow rate. Based on the fundamental investigation at room temperature, the surface tension of the \\hbox {SiO}2-40 \\hbox {mol}%\\hbox {Na}2\\hbox {O} and \\hbox {SiO}2-50 \\hbox {mol}%\\hbox {Na}2\\hbox {O} melts was determined at a high temperature. The obtained value was slightly lower than the literature values, which might be due to the influence of viscosity on surface tension measurements being removed in this study.

  18. Mobility Measurements Probe Conformational Changes in Membrane Proteins due to Tension

    Science.gov (United States)

    Morris, Richard G.; Turner, Matthew S.

    2015-11-01

    The function of membrane-embedded proteins such as ion channels depends crucially on their conformation. We demonstrate how conformational changes in asymmetric membrane proteins may be inferred from measurements of their diffusion. Such proteins cause local deformations in the membrane, which induce an extra hydrodynamic drag on the protein. Using membrane tension to control the magnitude of the deformations, and hence the drag, measurements of diffusivity can be used to infer—via an elastic model of the protein—how conformation is changed by tension. Motivated by recent experimental results [Quemeneur et al., Proc. Natl. Acad. Sci. U.S.A. 111, 5083 (2014)], we focus on KvAP, a voltage-gated potassium channel from Aeropyrum pernix. The conformation of KvAP is found to change considerably due to tension, with its "walls," where the protein meets the membrane, undergoing significant angular strains. The torsional stiffness is determined to be 26.8 kBT per radian at room temperature. This has implications for both the structure and the function of such proteins in the environment of a tension-bearing membrane.

  19. Rocket plume temperature measurement by wire welded thermocouples

    Science.gov (United States)

    Xu, Qiang

    2006-05-01

    The plume of solid rocket motor is a high velocity flow with high temperature. Temperature distribution in the plume is of great interest for analyzing the compatibility of rocket weapon system. The high temperature exhausted flow field would cause damage on certain equipment and loading vehicles. An instantaneous temperature field with sharp step is established by the exhausted flow field of rocket motor. The increasing rate of the step depends on the flow velocity at cross section of nozzle exit. To perform an accurate measurement of temperature inside the flow field, a thermocouple must be sturdy enough to endure the flow impingement. In the meantime, the thermocouple must have a short time constant to trace the temperature fluctuation in flow field and a small size to avoid disturbing the flow field severely. The dynamic performance of the thermocouples used in exhausted flow temperature measurement must be evaluated before the experiment. The thermocouple which can be used in measuring the temperature distribution in rocket plume was presented in this paper. A NAMNAC (R) self-renew-erode thermocouples with a nominal time constant of 10 microseconds was used as a reference in a dynamic calibration test for this kind of thermocouple. The thermocouple could trace the temperature increase in the exhausted flow perfectly. This kind of thermocouples was used in several real tests of rocket motors, such as the temperature in free exhausted flow field of a stationary rocket motor test, the stagnate temperature in a shock flow field during the launching of a rocket, and the temperature in a launch tube.

  20. Determination of gas-oil miscibility conditions by interfacial tension measurements.

    Science.gov (United States)

    Rao, Dandina N; Lee, Jong I

    2003-06-15

    Processes that inject gases such as carbon dioxide and natural gas have long been and still continue to be used for recovering crude oil from petroleum reservoirs. It is well known that the interfacial tension between the injected gas and the crude oil has a major influence on the efficiency of displacement of oil by gas. When the injected gas becomes miscible with the crude oil, which means that there is no interface between the injected and displaced phases or the interfacial tension between them is zero, the oil is displaced with maximum efficiency, resulting in high recoveries. This paper presents experimental measurements of interfacial tension between crude oil and natural gases (using a computerized drop shape analysis technique) as a function of pressure and gas composition at the temperature of the reservoir from which the crude oil was obtained. The point of zero interfacial tension was then identified from these measurements by extrapolation of data to determine minimum miscibility pressure (MMP) and minimum miscibility composition (MMC). The gas-oil miscibility conditions thus obtained from interfacial tension measurements have been compared with the more conventional techniques using slim-tube tests and rising-bubble apparatus as well as predictive correlations and visual observations. The miscibility pressures obtained from the new VIT technique were 3-5% higher than those from visual observations and agreed well with the slim-tube results as well as with the correlations at enrichment levels greater than 30 mol% C2+ in the injected gas stream. The rising bubble apparatus yielded significantly higher MMPs. This study demonstrates that the VIT technique is rapid, reproducible, and quantitative, in addition to providing visual evidence of gas-oil miscibility.

  1. From transmission error measurement to Pulley-Belt slip determination in serpentine belt drives : influence of tensioner and belt characteristics

    OpenAIRE

    Manin, Lionel; Michon, Guilhem; Rémond, Didier; Dufour, Regis

    2009-01-01

    Serpentine belt drives are often used in front end accessory drive of automotive engine. The accessories resistant torques are getting higher within new technological innovations as stater-alternator, and belt transmissions are always asked for higher capacity. Two kind of tensioners are used to maintain minimum tension that insure power transmission and minimize slip: dry friction or hydraulic tensioners. An experimental device and a specific transmission error measurement method have been u...

  2. Atmospheric Aqueous Aerosol Surface Tensions: Isotherm-Based Modeling and Biphasic Microfluidic Measurements.

    Science.gov (United States)

    Boyer, Hallie C; Dutcher, Cari S

    2017-06-29

    Surface properties of atmospheric aerosol particles are crucial for accurate assessments of the fates of liquid particles in the atmosphere. Surface tension directly influences predictions of particle activation to clouds, as well as indirectly acting as a proxy for chemical surface partitioning. Challenges to accounting for surface effects arise from surface tension dependence on solution concentration and the presence of complex aqueous mixtures in aerosols, including both surface-active organic solutes and inorganic electrolytes. Also, the interface itself is varied, in that it may be a liquid-vapor interface, as in the surface of an aerosol particle with ambient air, or a liquid-liquid interface between two immiscible liquids, as in the interior surfaces that exist in multiphase particles. In this Feature Article, we highlight our previous work entailing thermodynamic modeling of liquid-vapor surfaces to predict surface tension and microscopic examinations of liquid-liquid interfacial phenomena to measure interfacial tension using biphasic microscale flows. New results are presented for binary aqueous organic acids and their ternary solutions with ammonium sulfate. Ultimately, improved understanding of aerosol particle surfaces would enhance treatment of aerosol particle-to-cloud activation states and aerosol effects on climate.

  3. Surface Tension and Viscosity Measurements in Microgravity: Some Results and Fluid Flow Observations during MSL-1

    Science.gov (United States)

    Hyer, Robert W.; Trapaga, G.; Flemings, M. C.

    1999-01-01

    The viscosity of a liquid metal was successfully measured for the first time by a containerless method, the oscillating drop technique. This method also provides a means to obtain a precise, non-contact measurement of the surface tension of the droplet. This technique involves exciting the surface of the molten sample and then measuring the resulting oscillations; the natural frequency of the oscillating sample is determined by its surface tension, and the damping of the oscillations by the viscosity. These measurements were performed in TEMPUS, a microgravity electromagnetic levitator (EML), on the Space Shuttle as a part of the First Microgravity Science Laboratory (MSL-1), which flew in April and July 1997 (STS-83 and STS-94). Some results of the surface tension and viscosity measurements are presented for Pd82Si18. Some observations of the fluid dynamic characteristics (dominant flow patterns, turbulent transition, cavitation, etc.) of levitated droplets are presented and discussed together with magnetohydrodynamic calculations, which were performed to justify these findings.

  4. New devices for flow measurements: Hot film and burial wire sensors, infrared imagery, liquid crystal, and piezo-electric model

    Science.gov (United States)

    Mcree, Griffith J., Jr.; Roberts, A. Sidney, Jr.

    1991-01-01

    An experimental program aimed at identifying areas in low speed aerodynamic research where infrared imaging systems can make significant contributions is discussed. Implementing a new technique, a long electrically heated wire was placed across a laminar flow. By measuring the temperature distribution along the wire with the IR imaging camera, the flow behavior was identified.

  5. Analysis of ultra-relativistic charged particle beam and stretched wire measurement interactions with cylindrically symmetric structures

    Energy Technology Data Exchange (ETDEWEB)

    Deibele, C. E. [Univ. of Wisconsin, Madison, WI (United States)

    1996-01-01

    The beam impedance and wakefield are quantities which describe the stability of charged particles in their trajectory within an accelerator. The stretched wire measurement technique is a method which estimates the beam impedance and wakefield. Definitions for the beam impedance, the wakefield, and the stretched wire measurement are presented. A pillbox resonator with circular beampipes is studied for its relatively simple profile and mode structure. Theoretical predictions and measurement data are presented for the interaction of various charged particle beams and center conductor geometries between the cavity and beampipe. Time domain predictions for the stretched wire measurement and wakefield are presented and are shown to be a linear interaction.

  6. Influence of specimen type and reinforcement on measured tension-tension fatigue life of unidirectional GFRP laminates

    DEFF Research Database (Denmark)

    Korkiakoski, Samuli; Brøndsted, Povl; Sarlin, Essi

    2016-01-01

    in accordance with the ISO 527-5 standard and two slightly different dog-bone shaped specimens were evaluated by means of finite element modelling. Subsequent comparative fatigue tests were performed for the laminates with the three specimen types. The results showed that the test specimen type has......It is well known that standardised tension-tension fatigue test specimens of unidirectional (UD) glass-fibre-reinforced plastics (GFRP) laminates tend to fail at end tabs. The true fatigue life is then underestimated. The first objective of this study was to find for UD GFRP laminates a test...... specimen that fails in the gauge section. The second objective was to compare fatigue performance of two laminates, one having a newly developed UD powder-bound fabric as a reinforcement and the other having a quasi-UD stitched non-crimp fabric as a reinforcement. In the first phase, a rectangular specimen...

  7. A Study on Constitution of Plant Safety Inspection System for Measuring Joint Axial Force of High Tension Bolt

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. Y.; Kim, C. H.; You, S. [Chosun University, Gwangju (Korea, Republic of); Park, S. G. [Yu su Fisheries University, Yeosu (Korea, Republic of); Kim, H. S. [KIA Technique Research Institute, Hwaseong (Korea, Republic of)

    1995-09-15

    By using ultrasonic waves, we obtained conclusion from the experiment for measuring joint axial force of high tension bolt. The conclusion is followed. : From the high tension bolts used at turbine of Thermoelectric Power Plant, we obtained the equation of calculating joint axial force that is {sigma}=jx{Sigma}{delta}/{Delta}BPD. By using IBM PC, which is inputted by the equation for calculating joint axial force of high tension bolts, we got joint axial force of high tension bolts form beam path of ultrasonic waves. Further, we can identify that constitution of plant safety inspection system is possible

  8. Measurement of effective alveolar carbon dioxide tension during spontaneous breathing in normal subjects and patients with chronic airways obstruction.

    OpenAIRE

    Jordanoglou, J.; Koulouris, N; Kyroussis, D.; Rapakoulias, P.; Vassalos, P.; Madianos, J.

    1995-01-01

    BACKGROUND--The measurement of effective alveolar carbon dioxide tension (PA-CO2eff) is still a matter of debate. It has, however, become common practice to use arterial instead of alveolar CO2 tension for computing alveolar oxygen tension (PAO2) and physiological dead space, not only in normal subjects but also in patients. The purpose of this study was to estimate alveolar CO2 tension during spontaneous breathing with a new bedside technique which is simple and non-invasive, and to compare ...

  9. Estimation of cables’ tension of cable-stayed footbridge using measured natural frequencies

    Directory of Open Access Journals (Sweden)

    Jakiel Przemysław

    2017-01-01

    Full Text Available This paper presents analysis of cables’ tension of steel cable-stayed footbridge using their field-test natural frequencies. A vibration method is usually used for the measured cable tension during the construction of cable systems stiffened with inclined cables. Practical formulas for the vibration method applied herein, mainly based on cable-sag and vertical angle effects (a survey measurement, have been verified on the one-tower steel cable-stayed bridge. The bridge is situated in Sieradz (Poland and it was the structure with the longest span concerning all the cable-stayed bridges in Poland until 1999. The obtained cable axial forces for estimated natural frequencies of low- and high-order modes are verified using FEM models. The final conclusions drawn on the basis of conducted studies can be useful for technical diagnosis, monitoring programs and repair works of similar class of cable-stayed bridges.

  10. Wire measurement of impedance of an X-band accelerating structure

    CERN Document Server

    Baboi, N; Dolgashev, V A; Jones, R M; Lewandowski, J R; Tantawi, S G; Wang, J W

    2004-01-01

    Several tens of thousands of accelerator structures will be needed for the next generation of linear collders known as the GLC/NLC (Global Linear Collider/Next Linear Collider). To prevent the beam being driven into a disruptive BBU (Beam Break Up) mode or at the very least, the emittance being signifcantly diluted, it is important to damp down the wakefield left by driving bunches to a manageable level. Manufacturing errors and errors in design need to be measurable and compared with predictions. We develop a circuit model of wire-loaded X-band accelerator structures. This enables the wakefield (the inverse transform of the beam impedance) to be readily computed and compared with the wire measurement. We apply this circuit model to the latest series of accelerating for the GLC/NLC. This circuit model is based upon the single-cell model developed in [1] extended here to complete, multi-cell structures.

  11. On the magnetic and magnetoelastic uniformity measurements on magnetostrictive ribbons and wires

    Energy Technology Data Exchange (ETDEWEB)

    Petridis, C. [Laboratory of Physical Metallurgy, National Technical University of Athens, Zografou Campus, Athens 15780 (Greece); Ktena, A. [Technological Education Institute of Chalkis, Euboea 34400 (Greece); Bolshakova, I. [Magnetic Sensor Laboratory, LPNU, 12 Bandera Str., Lviv 79013 (Ukraine); Hristoforou, E. [Laboratory of Physical Metallurgy, National Technical University of Athens, Zografou Campus, Athens 15780 (Greece)]. E-mail: eh@metal.ntua.gr

    2007-09-15

    In this paper, results on magnetic and magnetoelastic uniformity measurements concerning magnetostrictive ribbons are presented. Measurements are based on the magnetostrictive delay line (MDL) technique, which is used for the determination of B(H) and {lambda}(H) loops of long magnetostrictive ribbons, wires and rods of uniform rectangular cross section. The principle of operation for the B(H) and {lambda}(H) loop determination is based on the biasing field effect at the receiving and excitation coil of the MDL, respectively. The automated device used allowed the in situ parametric control of field, frequency, temperature and mechanical stress. The magnetic and magnetoelastic softening of amorphous Fe-Si-B ribbons, after stress-current annealing, is illustrated. This technique may be used for the non-destructive quality control of magnetostrictive ribbons and wires, used as sensing cores.

  12. New sensitive micro-measurements of dynamic surface tension and diffusion coefficients

    DEFF Research Database (Denmark)

    Kinoshita, Koji; Ortiz, Elisa Parra; Needham, David

    2017-01-01

    Currently available dynamic surface tension (DST) measurement methods, such as Wilhelmy plate, droplet- or bubble-based methods, still have various experimental limitations such as the large size of the interface, convection in the solution, or a certain “dead time” at initial measurement...... for surface excess concentration. We found that the measured diffusion coefficient of 1-Octanol, 7.2 ± 0.8 × 10−6 cm2/s, showed excellent agreement with the result from an alternative method, “single microdroplet catching method”, to measure the diffusion coefficient from diffusion-controlled microdroplet...

  13. Tearing-off method based on single carbon nanocoil for liquid surface tension measurement

    Science.gov (United States)

    Wang, Peng; Pan, Lujun; Deng, Chenghao; Li, Chengwei

    2016-11-01

    A single carbon nanocoil (CNC) is used as a highly sensitive mechanical sensor to measure the surface tension coefficient of deionized water and alcohol in the tearing-off method. The error can be constrained to within 3.8%. Conversely, the elastic spring constant of a CNC can be accurately measured using a liquid, and the error is constrained to within 3.2%. Compared with traditional methods, the CNC is used as a ring and a sensor at the same time, which may simplify the measurement device and reduce error, also all measurements can be performed under a very low liquid dosage owing to the small size of the CNC.

  14. MC Sensor—A Novel Method for Measurement of Muscle Tension

    Directory of Open Access Journals (Sweden)

    Sašo Tomažič

    2011-09-01

    Full Text Available This paper presents a new muscle contraction (MC sensor. This MC sensor is based on a novel principle whereby muscle tension is measured during muscle contractions. During the measurement, the sensor is fixed on the skin surface above the muscle, while the sensor tip applies pressure and causes an indentation of the skin and intermediate layer directly above the muscle and muscle itself. The force on the sensor tip is then measured. This force is roughly proportional to the tension of the muscle. The measurement is non-invasive and selective. Selectivity of MC measurement refers to the specific muscle or part of the muscle that is being measured and is limited by the size of the sensor tip. The sensor is relatively small and light so that the measurements can be performed while the measured subject performs different activities. Test measurements with this MC sensor on the biceps brachii muscle under isometric conditions (elbow angle 90° showed a high individual linear correlation between the isometric force and MC signal amplitudes (0.97 ≤ r ≤ 1. The measurements also revealed a strong correlation between the MC and electromyogram (EMG signals as well as good dynamic behaviour by the MC sensor. We believe that this MC sensor, when fully tested, will be a useful device for muscle mechanic diagnostics and that it will be complementary to existing methods.

  15. A surface tension based method for measuring oil dispersant concentration in seawater.

    Science.gov (United States)

    Cai, Zhengqing; Gong, Yanyan; Liu, Wen; Fu, Jie; O'Reilly, S E; Hao, Xiaodi; Zhao, Dongye

    2016-08-15

    This work developed a new method to determine concentration of Corexit EC9500A, and likely other oil dispersants, in seawater. Based on the principle that oil dispersants decrease surface tension, a linear correlation was established between the dispersant concentration and surface tension. Thus, the dispersant concentration can be determined by measuring surface tension. The method can accurately analyze Corexit EC9500A in the concentration range of 0.5-23.5mg/L. Minor changes in solution salinity (<0.3%), pH (7.9-9.0), and dissolved organic matter (<2.0mg/L as TOC) had negligible effects on the measurements. Moreover, effects of extracts from marine sediments were negligible, and thus, the method may be directly applied to seawater-sediment systems. The method accuracy was confirmed by comparing with direct TOC analysis. This simple, fast, economical method offers a convenient analytical tool for quantifying complex oil dispersants in water/seawater, which has been desired by the oil spill research community and industries. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. A progressively reduced pretension method to fabricate Bradbury-Nielsen gates with uniform tension

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Kai, E-mail: ni.kai@sz.tsinghua.edu.cn; Guo, Jingran; Yu, Zhou; Cao, Like; Yu, Quan; Qian, Xiang [Division of Advanced Manufacturing, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Wang, Xiaohao [Division of Advanced Manufacturing, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); State Key Laboratory of Precision Measure Technology and Instruments, Tsinghua University, Beijing 100084 (China)

    2015-11-15

    A Bradbury-Nielsen gate (BNG) is often used to modulate ion beams. It consists of two interleaved and electrically isolated sets of wires with uniform tension, which ideally keep parallel, equidistant, and coplanar over a wide temperature range, making the BNG reliable and robust. We have previously analyzed the non-uniformity problem of wire tensions with sequentially winding method and developed a template-based transfer method to solve this problem. In this paper, we introduced a progressively reduced pretension method, which allows directly and sequentially fixing wires onto the substrate without using a template. Theoretical analysis shows that by applying proper pretension to each wire when fixing it, the final wire tensions of all wires can be uniform. The algorithm and flowchart to calculate the pretension sequence are given, and the fabrication process is introduced in detail. Pretensions are generated by weight combination with a weaving device. A BNG with stainless steel wire and a printed circuit board substrate is constructed with this method. The non-uniformity of the final wire tensions is less than 2.5% in theory. The BNG is successfully employed in our ion mobility spectrometer, and the measured resolution is 33.5 at a gate opening time of 350 μs. Compared to the template-based method, this method is simpler, faster, and more flexible with comparable production quality when manufacturing BNGs with different configurations.

  17. Interpretation of contact angle measurements on two different fluoropolymers for the determination of solid surface tension.

    Science.gov (United States)

    Tavana, H; Simon, F; Grundke, K; Kwok, D Y; Hair, M L; Neumann, A W

    2005-11-15

    Contact angle measurements with a large number of liquids on the semi-fluorinated acryl polymer EGC-1700 films are reported. The surface tension was determined to be gammasv=13.84 mJ/m2 from contact angles of octamethylcyclotetrasiloxane (OMCTS) and decamethylcyclopentasiloxane (DMCPS). Inertness of these two liquids makes them ideal for determination of surface tension of low-energy fluoropolymers. On the other hand, contact angles of many other liquids deviated somewhat from a smooth contact angle pattern that represents the EGC-1700 surface tension. It is argued that noninertness of the molecules of these liquids gives rise to specific interactions with the polymer film, causing the deviations. Furthermore, contact angles of a series of n-alkanes (n-hexane to n-hexadecane) showed systematic deviations from this curve, similar to the trend observed for n-alkanes/Teflon AF 1600 systems studied earlier. Adsorption of vapor of short-chain liquids onto the polymer film caused their contact angles to fall above the gammasv=13.84 mJ/m2 curve, and a parallel alignment of molecules of the long-chain n-alkanes in the vicinity of the solid was the explanation for the deviation of their contact angles below it. It is found that vapor adsorption effect is more significant in the case of Teflon AF 1600, while the alignment of liquid molecules close to the surface is more pronounced for EGC-1700.

  18. Measurements of Flow Mixing at Subchannels in a Wire-Wrapped 37-Rod Bundle for a Sodium Cooled Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyungmo; Bae, Hwang; Chang, Seok-Kyu; Choi, Sun Rock; Lee, Dong Won; Ko, Yung Joo; Choi, Hae Seob; Euh, Dong-Jin; Lee, Hyeong-Yeon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    For a safety analysis in a core thermal design of a sodium-cooled fast reactor (SFR), flow mixing characteristics at subchannels in a wire-wrapped rod bundle are very important. Wrapped wires make a cross flow in a around the fuel rod) of the fuel rod, and this effect lets flow be mixed. Experimental results of flow mixing can be meaningful for verification and validation of thermal mixing correlation in a reactor core thermo-hydraulic design code. A wire mesh sensing technique can be useful method for measuring of flow mixing characteristics. A wire mesh sensor has been traditionally used to measure the void fraction of a two-phase flow field, i.e. gas and liquid. However, it has been recently reported that the wire mesh sensor can be used successfully to recognize the flow field in liquid phase by injecting a tracing liquid with a different level of electric conductivity. This can be powerfully adapted to recognize flow mixing characteristics by wrapped wires in SFR core thermal design. In this work, we conducted the flow mixing experiments using a custom designed wire mesh sensor. To verify and validate computer codes for the SFR core thermal design, mixing experiments were conducted at a hexagonally arrayed 37-pin wire-wrapped fuel rod bundle test section. The well-designed wire mesh sensor was used to measure flow mixing characteristics. The developed post-processing method has its own merits, and flow mixing results were reasonable. In addition, by uncertainty analysis, the system errors and the random error were estimated in experiments. Therefore, the present results and methods can be used for design code verification and validation.

  19. A hot-wire method based thermal conductivity measurement apparatus for teaching purposes

    Science.gov (United States)

    Alvarado, S.; Marín, E.; Juárez, A. G.; Calderón, A.; Ivanov, R.

    2012-07-01

    The implementation of an automated system based on the hot-wire technique is described for the measurement of the thermal conductivity of liquids using equipment easily available in modern physics laboratories at high schools and universities (basically a precision current source and a voltage meter, a data acquisition card, a personal computer and a high purity platinum wire). The wire, which is immersed in the investigated sample, is heated by passing a constant electrical current through it, and its temperature evolution, ΔT, is measured as a function of time, t, for several values of the current. A straightforward methodology is then used for data processing in order to obtain the liquid thermal conductivity. The start point is the well known linear relationship between ΔT and ln(t) predicted for long heating times by a model based on a solution of the heat conduction equation for an infinite lineal heat source embedded in an infinite medium into which heat is conducted without convective and radiative heat losses. A criterion is used to verify that the selected linear region is the one that matches the conditions imposed by the theoretical model. As a consequence the method involves least-squares fits in linear, semi-logarithmic (semi-log) and log-log graphs, so that it becomes attractive not only to teach about heat transfer and thermal properties measurement techniques, but also as a good exercise for students of undergraduate courses of physics and engineering learning about these kinds of mathematical functional relationships between variables. The functionality of the experiment was demonstrated by measuring the thermal conductivity in samples of liquids with well known thermal properties.

  20. Measurement method of magnetic field for the wire suspended micro-pendulum accelerometer.

    Science.gov (United States)

    Lu, Yongle; Li, Leilei; Hu, Ning; Pan, Yingjun; Ren, Chunhua

    2015-04-13

    Force producer is one of the core components of a Wire Suspended Micro-Pendulum Accelerometer; and the stability of permanent magnet in the force producer determines the consistency of the acceleration sensor's scale factor. For an assembled accelerometer; direct measurement of magnetic field strength is not a feasible option; as the magnetometer probe cannot be laid inside the micro-space of the sensor. This paper proposed an indirect measurement method of the remnant magnetization of Micro-Pendulum Accelerometer. The measurement is based on the working principle of the accelerometer; using the current output at several different scenarios to resolve the remnant magnetization of the permanent magnet. Iterative Least Squares algorithm was used for the adjustment of the data due to nonlinearity of this problem. The calculated remnant magnetization was 1.035 T. Compared to the true value; the error was less than 0.001 T. The proposed method provides an effective theoretical guidance for measuring the magnetic field of the Wire Suspended Micro-Pendulum Accelerometer; correcting the scale factor and temperature influence coefficients; etc.

  1. Measurement Method of Magnetic Field for the Wire Suspended Micro-Pendulum Accelerometer

    Directory of Open Access Journals (Sweden)

    Yongle Lu

    2015-04-01

    Full Text Available Force producer is one of the core components of a Wire Suspended Micro-Pendulum Accelerometer; and the stability of permanent magnet in the force producer determines the consistency of the acceleration sensor’s scale factor. For an assembled accelerometer; direct measurement of magnetic field strength is not a feasible option; as the magnetometer probe cannot be laid inside the micro-space of the sensor. This paper proposed an indirect measurement method of the remnant magnetization of Micro-Pendulum Accelerometer. The measurement is based on the working principle of the accelerometer; using the current output at several different scenarios to resolve the remnant magnetization of the permanent magnet. Iterative Least Squares algorithm was used for the adjustment of the data due to nonlinearity of this problem. The calculated remnant magnetization was 1.035 T. Compared to the true value; the error was less than 0.001 T. The proposed method provides an effective theoretical guidance for measuring the magnetic field of the Wire Suspended Micro-Pendulum Accelerometer; correcting the scale factor and temperature influence coefficients; etc.

  2. Joint angle measurement: a comparative study of the reliability of goniometry and wire tracing for the hand.

    Science.gov (United States)

    Ellis, B; Bruton, A; Goddard, J R

    1997-11-01

    To compare the inter- and intra-rater reliability of goniometry and wire tracing in the assessment of finger joint angles: metacarpo-phalangeal (MCPJ), proximal (PIPJ) and distal interphalangeal joints (DIPJ). Twenty occupational therapists and 20 physiotherapists with a range of clinical experience were recruited from nine different centres. Using a masked goniometer and wire tracing they carried out repeated assessments of the MCPJ, PIPJ and DIPJ of a normal subject fixed in two different positions. The two assessment methods did not produce comparable angle measurements. Goniometry showed greater inter- and intra-rater reliability than wire tracing. Regardless of the assessment tool, the repeatability coefficient indicated that DIPJ measurement was less reliable than the other joints. Clinical and specialist experience did not affect reliability. Although both goniometry and wire tracing show limitations as reliable assessment tools, it is recommended that where possible goniometry should be used.

  3. Design and implementation of a hot-wire probe for simultaneous velocity and vorticity vector measurements in boundary layers

    Science.gov (United States)

    Zimmerman, S.; Morrill-Winter, C.; Klewicki, J.

    2017-10-01

    A multi-sensor hot-wire probe for simultaneously measuring all three components of velocity and vorticity in boundary layers has been designed, fabricated and implemented in experiments up to large Reynolds numbers. The probe consists of eight hot-wires, compactly arranged in two pairs of orthogonal ×-wire arrays. The ×-wire sub-arrays are symmetrically configured such that the full velocity and vorticity vectors are resolved about a single central location. During its design phase, the capacity of this sensor to accurately measure each component of velocity and vorticity was first evaluated via a synthetic experiment in a set of well-resolved DNS fields. The synthetic experiments clarified probe geometry effects, allowed assessment of various processing schemes, and predicted the effects of finite wire length and wire separation on turbulence statistics. The probe was subsequently fabricated and employed in large Reynolds number experiments in the Flow Physics Facility wind tunnel at the University of New Hampshire. Comparisons of statistics from the actual probe with those from the simulated sensor exhibit very good agreement in trend, but with some differences in magnitude. These comparisons also reveal that the use of gradient information in processing the probe data can significantly improve the accuracy of the spanwise velocity measurement near the wall. To the authors' knowledge, the present are the largest Reynolds number laboratory-based measurements of all three vorticity components in boundary layers.

  4. Rotating Molten Metallic Drops and Related Phenomena: A New Approach to the Surface Tension Measurement

    Science.gov (United States)

    Rhim, Won-Kyu; Ishikawa, Takehiko

    2000-01-01

    Molten aluminum and tin drops were levitated in a high vacuum by controlled electric fields, and they were systematically rotated by applying by a rotating magnetic field. When the evolution of the drop shape was measured as a function of rotation frequency, it agreed quantitatively well with the Brown and Scriven's theoretical prediction. The normalized rotation frequencies at the bifurcation point agreed with the predicted value 0.559, within 2%. An anomalous phenomenon which totally deviated from the prediction was observed in rotating molten tin drops when they were kept in a high rotation rate for several hours. No anomaly was observed in aluminum drops when they underwent similar condition. It was speculated that under the strong centrifugal force in the drop the tin isotopes must be separating. Since Al-27 is essentially the only naturally abundant isotope in the aluminum drops, the same anomaly is not expected. Based on the shape deformation of a rotating drop, an alternate approach to the surface tension measurement was verified. This new surface tension measurement technique was applied to a glassforming alloy, Zr(41.2)Ti(13.8)Cu(12.5)Ni(10.0)Be(22.5) in its highly viscous states. Also demonstrated in the paper was a use of a molten aluminum drop to verify the Busse's prediction of the influence of the drop rotation on the drop oscillation frequency.

  5. Wired/Classic and Wireless/Periotest "M" instruments: an in vitro assessment of repeatability of stability measurements.

    Science.gov (United States)

    Crum, Patricia M; Morris, Harold Frederick; Winkler, Sheldon; DesRosiers, Deborah; Yoshino, Douglas

    2014-02-01

    This in vitro study evaluated agreement among 10 trained evaluators when assessing implant stability with the Wired/Classic and Wireless/Periotest "M." A difference of 1 Periotest value (PTV) between the wired (-7) and wireless (-8) instruments was observed for the pretest calibration ring. No significant differences were found between the instruments and for all evaluators for all tests (analysis of variance, P < .05). Each instrument can provide meaningful and reproducible recordings of stability measurements.

  6. New low cost sensing head and taut wire method for automated straightness measurement of machine tool axes

    OpenAIRE

    Borisov, Oleg; Fletcher, Simon; Longstaff, Andrew P.; Myers, Alan

    2013-01-01

    This paper describes a novel method to measure straightness error of an axis of motion with a system utilizing taut wire, optical sensor and reference error cancellation technique. In contrast to commonly used taut wire, straightedge or laser-based methods it combines simplicity of setup and low cost with high levels of automation, accuracy and repeatability. An error cancellation technique based on two-point method is applied for the first time to a versatile reference object which can be mo...

  7. Simultaneous, Unsteady PIV and Photogrammetry Measurements of a Tension-Cone Decelerator in Subsonic Flow

    Science.gov (United States)

    Schairer, Edward T.; Heineck, James T.; Walker, Louise Ann; Kushner, Laura Kathryn; Zilliac, Gregory

    2010-01-01

    This paper describes simultaneous, synchronized, high-frequency measurements of both unsteady flow in the wake of a tension-cone decelerator in subsonic flow (by PIV) and the unsteady shape of the decelerator (by photogrammetry). The purpose of these measurements was to develop the test techniques necessary to validate numerical methods for computing fluid-structure interactions of flexible decelerators. A critical need for this effort is to map fabric surfaces that have buckled or wrinkled so that code developers can accurately represent them. This paper describes a new photogrammetric technique that performs this measurement. The work was done in support of the Entry, Descent, and Landing discipline within the Supersonics Project of NASA s Fundamental Aeronautics Program.

  8. Noncontact measurement of high-temperature surface tension and viscosity of bulk metallic glass-forming alloys using the drop oscillation technique

    OpenAIRE

    Mukherjee, S.; Johnson, W. L.; Rhim, W. K.

    2005-01-01

    High-temperature surface tension and viscosities for five bulk metallic glass-forming alloys with widely different glass-forming abilities are measured. The measurements are carried out in a high-vacuum electrostatic levitator using the drop oscillation technique. The surface tension follows proportional mathematical addition of pure components' surface tension except when some of the constituent elements have much lower surface tension. In such cases, there is surface segregation of the low ...

  9. Applying hot-wire anemometry to directly measure the water balance in a proton exchange membrane fuel cell

    DEFF Research Database (Denmark)

    Al Shakhshir, Saher; Andreasen, Søren Juhl; Berning, Torsten

    2016-01-01

    In order to better understand and more accurately measure the water balance in a proton exchange membrane fuel cell, our group has recently proposed to apply hot wire anemometry in the fuel cell's anode outlet. It was theoretically shown that the electrical signal obtained from the hot wire sensor...... can be directly converted into the fuel cell water balance. In this work an ex-situ experimental investigation is performed to examine the effect of the wire diameter and the outlet pipe diameter on the voltage signal. For a laboratory fuel cell where the mass flow rate the anode outlet is small......, it is found important to use a small output pipe diameter to obtain a sufficiently strong convection effect and hence clear voltage readings. Depending on the hot wire diameter and the inner pipe diameter, the resulting values for the exponent of the Reynolds number Re in the determination of the Nusselt...

  10. USING HOT WIRE TECHNIQUE FOR MEASURING THERMAL CONDUCTIVITY OF INFUSIONS OF ORGANIC AND CONVENTIONAL COFFEE

    Directory of Open Access Journals (Sweden)

    Fernando Gordillo-Delgado

    2016-07-01

    Full Text Available The technique of hot wire, a versatile method of low cost and high accuracy for measuring the thermal conductivity of fluids through the increasing temperature of a wire that is immersed into the liquid and between its ends a potential difference is abruptly applied. Using well-known conductivity liquids: water, ethylene glycol and glycerine, the system was tested and calibrated. In this work, this procedure was used to measure the thermal conductivity of the infusion samples of organic and conventional coffee. The same roast degree of the beans was verified with a colorimeter and the preparation was made by pressing 22g of coffee powder in 110mL of water. The obtained data were subjected to Analysis of Variance (ANOVA and this confirmed that the differences in the thermophysical parameter in the two samples are significant with a confidence level of 95\\%. On this way, it was proved that the thermal conductivity value of the coffee infusion allows differentiate between organic and conventional coffee.

  11. Measurements of thermal conductivity and thermal diffusivity of hen egg-white lysozyme crystals using a short hot wire method

    Science.gov (United States)

    Fujiwara, Seiji; Maki, Syou; Tanaka, Seiichi; Maekawa, Ryunosuke; Masuda, Tomoki; Hagiwara, Masayuki

    2017-07-01

    Thermal conductivity and thermal diffusivity of hen egg-white lysozyme (HEWL) crystals were examined by using the transient short hot wire method. This method is based on the conventional hot wire method, but improved by using a wire that is much shorter than conventional ones. The magneto-Archimedes levitation technique was utilized to attach the HEWL crystals onto the wire. Owing to the upward magnetic force, the HEWL crystals were deposited at the air-liquid interface of the protein buffer solution where the short hot wire was preliminarily fixed. In situ observation clarified that the wire was completely buried into the HEWL crystals. By means of these techniques, the measurement of thermal conductivity and thermal diffusivity of HEWL crystals was realized for the first time. Gadolinium chloride (a paramagnetic subject) was used as a precipitant agent of crystallization. Crystal growth was carried out over 20 h at 17.2 °C. The applied magnetic field was 4 T. Measurements were conducted during the crystal growth at two different times. The thermal conductivity and diffusivity of the HEWL crystals were determined to be 0.410 W/(m.K) and 3.77×10-8 m2/s at 14 h after, and 0.438 W/(m.K) and 5.18×10-8 m2/s at 20 h after, respectively. We emphasize that this method is versatile and applicable for other protein crystals.

  12. Application of vision measurements for modal analysis of wires for the purpose of overhead transmission lines monitoring

    Science.gov (United States)

    Mendrok, Krzysztof; Dworakowski, Ziemowit; Holak, Krzysztof; Kohut, Piotr

    2017-05-01

    Overhead transmission power lines are still one of the crucial elements of electro-energetic system. There are obvious advantages of using overhead transmission in the distribution of electricity. The amount of energy transported through a power line is determined by the distance between the wire and the ground or other objects placed beneath it (eg. trees). This distance is not fixed and depends on the overhang of the wire. This, in turn, is determined by many factors such as ambient temperature, humidity, precipitation, the value of current flowing through the wire. In order to optimize the wires electrical load, the monitoring of that overhang is required. One way to measure it is the non-contact measurement by vision system. It has the advantage, that using high-speed cameras respectively it also allows for vibration measurement and analysis of dynamic performance. That is very important while the wires are susceptible to the influence of wind, and the resulting vibrations interfere with the correct measurement of the overhang. The paper presents the results of vision measurements of the system vibrations and modal analysis carried out on their basis. The study was conducted on a specially made laboratory stand.

  13. Local Neutron Flux Distribution Measurements by Wire-Dosimetry in the AMMON Experimental Program in the EOLE Reactor

    Directory of Open Access Journals (Sweden)

    Gruel A.

    2016-01-01

    Full Text Available Dosimetry measurements were carried out during the AMMON experimental program, in the EOLE facility. Al-0.1 wt% Au wires were positioned along curved fuel plates of JHR-type assemblies to investigate the azimuthal and axial gold capture rate profiles, directly linked to the thermal and epithermal flux. After irradiation, wires were cut into small segments (a few mm, and the gold capture rate of each part was measured by gamma spectrometry on the MADERE platform. This paper presents results in the “hafnium” configuration, and more specifically the azimuthal flux profile characterization. The final uncertainty on each measured wire lies below 1% (at 2 standard deviations. Experimental profiles are in a good agreement against Monte Carlo calculations, and the 4% capture rate increase at the plate edge is well observed. The flux dissymmetry due to assembly position in the core is also measured, and shows a 10% discrepancy between the two edges of the plate.

  14. A Comparative Study of Fast Wire Scanners, Beamscope and SEM-Grids for Emittance Measurements in the PS Booster

    CERN Document Server

    Arruat, M; Jansson, A; Lindroos, M; Martini, M; Olsfors, J; Raich, U; Schönauer, Horst Otto

    1997-01-01

    The tight emittance budget, imposed on the production of the high-brilliance beams in the LHC preinjectors, demands the elimination of all possible sources of beam blow-up. A prerequisite for this is reliable instrumentation and evaluation methods for comparison of their data. We have made a study of three methods for emittance measurement in the PS Booster: fast wire-scanners, BeamScope, and SEM-grids in a measurement line. For the fast wire-scanners, a full Monte-Carlo simulation was made of the beam-wire interaction, for an energy range from 100 MeV to 1 GeV, and compared to measured values. Data from a scraping method (BeamScope) are compared to profile measurements, using Abel-type integral transformations. Results will be presented.

  15. Measurement of a small vertical emittance with a laser wire beam profile monitor

    Directory of Open Access Journals (Sweden)

    Hiroshi Sakai

    2002-12-01

    Full Text Available We describe in this paper a measurement of vertical emittance in the Accelerator Test Facility (ATF damping ring at KEK with a laser wire beam profile monitor. This monitor is based on the Compton scattering process of electrons with a laser light target which is produced by injecting a cw laser beam into a Fabry-Perot optical cavity. We installed the monitor at a straight section of the damping ring and measured the vertical emittance with three different ring conditions. In all cases, the ATF ring was operated at 1.28 GeV in a single bunch mode. When the ring was tuned for ultralow emittance, the vertical emittance of ε_{y}=(1.18±0.08×10^{-11}   mrad was achieved. This shows that the ATF damping ring has realized its target value also vertically.

  16. Determination of the inductance of imploding wire array Z-pinches using measurements of load voltage

    Energy Technology Data Exchange (ETDEWEB)

    Burdiak, G. C.; Lebedev, S. V.; Hall, G. N.; Harvey-Thompson, A. J.; Suzuki-Vidal, F.; Swadling, G. F.; Khoory, E.; Pickworth, L.; Bland, S. N.; Grouchy, P. de; Skidmore, J. [Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom)

    2013-03-15

    The inductance of imploding cylindrical wire array z-pinches has been determined from measurements of load voltage and current. A thorough analysis method is presented that explains how the load voltage of interest is found from raw signals obtained using a resistive voltage divider. This method is applied to voltage data obtained during z-pinch experiments carried out on the MAGPIE facility (1.4 MA, 240 ns rise-time) in order to calculate the load inductance and thereafter the radial trajectory of the effective current sheath during the snowplough implosion. Voltage and current are monitored very close to the load, allowing these calculations to be carried out without the need for circuit modelling. Measurements give a convergence ratio for the current of between 3.1 and 5.7 at stagnation of the pinch.

  17. Landing Gear Components Noise Study - PIV and Hot-Wire Measurements

    Science.gov (United States)

    Hutcheson, Florence V.; Burley, Casey L.; Stead, Daniel J.; Becker, Lawrence E.; Price, Jennifer L.

    2010-01-01

    PIV and hot-wire measurements of the wake flow from rods and bars are presented. The test models include rods of different diameters and cross sections and a rod juxtaposed to a plate. The latter is representative of the latch door that is attached to an aircraft landing gear when the gear is deployed, while the single and multiple rod configurations tested are representative of some of the various struts and cables configuration present on an aircraft landing gear. The test set up is described and the flow measurements are presented. The effect of model surface treatment and freestream turbulence on the spanwise coherence of the vortex shedding is studied for several rod and bar configurations.

  18. Dynamic surface tension measurement for the screening of biosurfactants produced by Lactobacillus plantarum subsp. plantarum PTCC 1896.

    Science.gov (United States)

    Bakhshi, Nafiseh; Soleimanian-Zad, Sabihe; Sheikh-Zeinoddin, Mahmoud

    2017-06-01

    Currently, screening of microbial biosurfactants (BSs) is based on their equilibrium surface tension values obtained using static surface tension measurement. However, a good surfactant should not only have a low equilibrium surface tension, but its dynamic surface tension (DST) should also decrease rapidly with time. In this study, screening of BSs produced by Lactobacillus plantarum subsp. plantarum PTCC 1896 (probiotic) was performed based on their DST values measured by Wilhelmy plate tensiometry. The relationship between DST and structural and functional properties (anti-adhesive activity) of the BSs was investigated. The results showed that the changes in the yield, productivity and structure of the BSs were growth medium and incubation time dependent (psurface tension values. However, differences among the structure/yield of the BSs were observed through the measurement of their DST. The considerable dependence of DST on the concentration and composition of the BS proteins was observed (p<0.05). Moreover, the anti-adhesive activity of the BS was found to be positively correlated with its DST. The results suggest that the DST measurement could serve as an efficient method for the clever screening of BSs producer/production condition, and consequently, for the investigation of probiotic features of bacteria, since the anti-adhesive activity is an important criterion of probiotics. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Magnetic field measurements of the CEBAF (NIST) wiggler using the pulsed wire method

    Science.gov (United States)

    Wallace, Stephen M.

    1992-09-01

    The Free Electron Laser (FEL) has proven to be a versatile photon source for many applications in science, industry, and defense. It is capable of providing wide tunability and high efficiency, but has yet to yield high average power required as a weapon system. The proposed infrared and ultraviolet FELs at the Continuous Electron Beam Accelerator Facility (CEBAF) have been projected to provide high average power. The first section of this thesis will study the necessity of a FEL for shipboard defense, and state the advantages over other defense systems. The remainder will focus on use of the pulsed wire method for measuring the magnetic field errors of the CEBAF/National Institute of Science and Technology (NIST) wiggler. Data analysis indicates the wiggler will have a net electron beam deflection of x = 5.2 mm, which is much greater than the electron beam radius of re = 0.4 mm and the optical mode waist of wo = 1 mm.

  20. Quantitative absorption spectra of quantum wires measured by analysis of attenuated internal emissions

    Science.gov (United States)

    Yoshita, Masahiro; Okada, Takayuki; Akiyama, Hidefumi; Okano, Makoto; Ihara, Toshiyuki; Pfeiffer, Loren N.; West, Ken W.

    2012-03-01

    An absorption-spectroscopy method that utilizes internal emissions as the source of the probe light was used to measure the absorption spectra of quasi-one-dimensional (q-1D) excitons in T-shaped quantum wires embedded in an optical waveguide. The modal absorption area of the 1D ground-state excitons was estimated to be 0.39 eV cm-1 and was almost independent of temperature in the range 4-150 K. Quantitative evaluation using the absorption spectra revealed that the absorption cross-section per unit length at resonance peak and the spectrally integrated absorption cross-section area per unit length of the 1D ground-state excitons were 1.0 nm and 2.5 × 10-3 eV nm, respectively.

  1. Creation of subsonic macro-and microjets facilities and automated measuring system (AMS-2) for the spatial - temporal hot - wire anemometric visualization of jet flow field

    Science.gov (United States)

    Sorokin, A. M.; Grek, G. R.; Gilev, V. M.; Zverkov, I. D.

    2017-10-01

    Macro-and microjets facilities for generation of the round and plane subsonic jets are designed and fabricated. Automated measuring system (AMS - 2) for the spatial - temporal hot - wire anemometric visualization of jet flow field is designed and fabricated. Coordinate device and unit of the measurement, collecting, storage and processing of hot - wire anemometric information were integrated in the AMS. Coordinate device is intended for precision movement of the hot - wire probe in jet flow field according to the computer program. At the same time accuracy of the hot - wire probe movement is 5 microns on all three coordinates (x, y, z). Unit of measurement, collecting, storage and processing of hot - wire anemometric information is intended for the hot - wire anemometric measurement of the jet flow field parameters (registration of the mean - U and fluctuation - u' characteristics of jet flow velocity), their accumulation and preservation in the computer memory, and also carries out their processing according to certain programms.

  2. Synchronous Measuring Techniques in Parallel to MRE: Study of Pressure, Pre-Tension, and Surface Dynamics

    Science.gov (United States)

    Brinker, Spencer Thomas

    The contents of this dissertation include investigations in Magnetic Resonance Elastography (MRE) using a preclinical 9.4 Tesla small animal Magnetic Resonance Imaging (MRI) system along with synthetic materials that mimic the mechanical properties of soft human tissue. MRE is used for studying the mechanical behavior of soft tissue particularly applicable to medical applications. Wave motion induced by a mechanical driver is measured with MRI to acquire internal displacement fields over time and space within a material media. Complex shear modulus of the media is calculated from the response of mechanical wave transmission through the material. Changes in soft tissue stiffness is associated with disease progression and thus, is why assessing tissue mechanical properties with MRE has powerful diagnostic potential due to the noninvasive procedure of MRI. The experiments performed in this dissertation used elastic phantoms and specimens to observe the influence of pre-stress on MRE derived mechanical properties while additional mechanical measurements from other related material testing methods were synchronously collected alongside MRI scanning. An organ simulating phantom was used to explore changes in MRE stiffness in response to gas and liquid cyclic pressure loading. MRE stiffness increased with pressure and hysteresis was observed in cyclic pressure loading. The results suggest MRE is applicable to pressure related disease assessment. In addition, an interconnected porosity pressure phantom was constructed for future porous media investigations. A custom system was also built to demonstrate concurrent tensile testing during MRE for investigating homogeneous soft material media undergoing pre-tension. Stiffness increased with uniaxial tensile stress and strain. The tension and stiffness relationship explored can be related to the stress analysis of voluntary muscle. The results also offer prospective experimental strategies for community wide standards on MRE

  3. Studies on the interaction between nanodiamond and human hemoglobin by surface tension measurement and spectroscopy methods.

    Science.gov (United States)

    Pishkar, Leila; Taheri, Saba; Makarem, Somayeh; Alizadeh Zeinabad, Hojjat; Rahimi, Arash; Saboury, Ali Akbar; Falahati, Mojtaba

    2017-02-01

    In this study, a novel method to probe molecular interactions and binding of human hemoglobin (Hb) with nanodiamond (ND) was introduced based on the surface tension measurement. This method complements conventional techniques, which are basically done by zeta potential and dynamic light scattering (DLS) measurements, near and far circular dichroism (CD) spectroscopy, intrinsic and extrinsic fluorescence spectroscopy. Addition of ND to Hb solution increased the surface tension value of Hb-ND complex relative to those of Hb and ND molecules. The zeta potential values reveled that Hb and ND provide identical charge distribution at pH 7.5. DLS measurements demonstrated that Hb, ND, and ND-Hb complex have hydrodynamic radiuses of 98.37 ± 4.57, 122.07 ± 7.88 nm and 62.27 ± 3.70 at pH of 7.5 respectively. Far and near UV-CD results indicated the loss of α-helix structure and conformational changes of Hb, respectively. Intrinsic fluorescence data demonstrated that the fluorescence quenching of Hb by ND was the result of the static quenching. The hydrophobic interaction plays a pivotal role in the interaction of ND with Hb. Fluorescence intensity changes over time revealed conformational change of Hb continues after the mixing of the components (Hb-ND) till 15 min, which is indicative of the denaturation of the Hb relative to the protein control. Extrinsic fluorescence data showed a considerable enhancement of the ANS fluorescence intensity of Hb-ND system relative to the Hb till 60 nM of ND, likely persuaded by greater exposure of nonpolar residues of Hb hydrophobic pocket. The remarkable decrease in T m value of Hb in Hb-ND complex exhibits interaction of Hb with ND conducts to conformational changes of Hb. This study offers consequential discrimination into the interaction of ND with proteins, which may be of significance for further appeal of these nanoparticles in biotechnology prosecution.

  4. The efficacy of a “double-D-shaped” wire marker for radiographic measurement of acetabular cup orientation and wear

    OpenAIRE

    Derbyshire, Brian; Raut, Videshnandan V.

    2013-01-01

    Historically, wire markers were attached to cemented all-plastic acetabular cups to demarcate the periphery and to measure socket wear. The wire shape was either a semi-circle passing over the pole of the cup, or a circle around the cup equator. More recently, “double-D” shaped markers were introduced with a part-circular aspect passing over the pole and a semi-circular aspect parallel to the equatorial plane. This configuration enabled cup retroversion to be distinguished from anteversion. I...

  5. Hot wire anemometer measurements in the unheated air flow tests of the SRB nozzle-to-case joint

    Science.gov (United States)

    Ramachandran, N.

    1988-01-01

    Hot-Wire Anemometer measurements made in the Solid Rocket Booster (SRB) nozzle-to-case joint are discussed. The study was undertaken to glean additional information on the circumferential flow induced in the SRB nozzle joint and the effect of this flow on the insulation bonding flaws. The tests were conducted on a full-scale, 2-D representation of a 65-in long segment of the SRB nozzle joint, with unheated air as the working fluid. Both the flight Mach number and Reynolds number were matched simultaneously and different pressure gradients imposed along the joint face were investigated. Hot-wire anemometers were used to obtain velocity data for different joint gaps and debond configurations. The procedure adopted for hot-wire calibration and use is outlined and the results from the tests summarized.

  6. Rapid pre-tension loss in the Ilizarov external fixator: an in vitro study.

    NARCIS (Netherlands)

    Aquarius, R.J.M.; Kampen, A. van; Verdonschot, N.J.J.

    2007-01-01

    BACKGROUND AND PURPOSE: Wire pre-tension in the Ilizarov frame is considered to be important in order to reduce movements that can impair fracture healing. Wires will eventually lose part of their pre-tension, however. In order to gain more insight into the need for wire pre-tension, we

  7. Measurement of effective alveolar carbon dioxide tension during spontaneous breathing in normal subjects and patients with chronic airways obstruction.

    Science.gov (United States)

    Jordanoglou, J; Koulouris, N; Kyroussis, D; Rapakoulias, P; Vassalos, P; Madianos, J

    1995-03-01

    The measurement of effective alveolar carbon dioxide tension (PA-CO2eff) is still a matter of debate. It has, however, become common practice to use arterial instead of alveolar CO2 tension for computing alveolar oxygen tension (PAO2) and physiological dead space, not only in normal subjects but also in patients. The purpose of this study was to estimate alveolar CO2 tension during spontaneous breathing with a new bedside technique which is simple and non-invasive, and to compare these values with arterial CO2 tension measured in normal subjects and patients with chronic airways obstruction. The subjects breathed quietly through the equipment assembly (mouthpiece, monitoring ring, Fleisch transducer head) connected to a pneumotachograph and a fast response infrared CO2 analyser. The method is a computerised calculation of the volume weighted effective alveolar CO2 tension obtained from the simultaneously recorded expiratory flow and CO2 concentration versus time curves. An arterial blood sample was taken to measure PaCO2 for comparison during the study. The results showed a mean difference (PACO2eff-PaCO2) of -0.205 kPa in 20 normal subjects and -0.460 kPa in 46 patients. The 95% confidence interval of the bias was -0.029 to -0.379 kPa in normal subjects and -0.213 to -0.707 kPa in patients. The limits of agreement between PACO2eff and PaCO2 were 0.526 to -0.935 in normal subjects and 1.170 to -2.088 in patients. The volume weighted effective alveolar PCO2 in normal subjects and patients with chronic airways obstruction is lower than the arterial PCO2 and is recommended as a better estimate in the classical equations for estimating dead space and intrapulmonary shunt.

  8. Effect of surfactant headgroups on the oil/water interface: An interfacial tension measurement and simulation study

    Science.gov (United States)

    Xu, Jiafang; Zhang, Yang; Chen, Haixiang; Wang, Pan; Xie, Zhenhua; Yao, Yongji; Yan, Youguo; Zhang, Jun

    2013-11-01

    In the article, four anionic surfactants with different headgroups and same alkyl tail, sodium dodecyl sulfonate (SDSn), sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (SDBS), and sodium dodecyl-di(oxyethylene) ether sulfate (AES), are adopted to investigate the influence of headgroup structure on oil-water interfacial tensions. The measured experimental results present that the capability of the four surfactants reducing interfacial tension follows the order of AES > SDBS > SDS > SDSn. Furthermore, molecular dynamic simulation (MD) is conducted to investigate the interfacial property of the four surfactants, and three parameters, interface formation energy, interfacial thickness, interaction between surfactant and water, are proposed to reveal the effecting mechanism of molecular structure on interfacial tension. And then, the polarity is studied by quantum mechanics calculation (QM) to investigate the interaction between headgroup and water molecule. The researched results indicate the addition of oxygen, benzene ring and oxyethyl group would enhance the polarity of surfactant, which induce the increase of interaction between headgroup and water molecule. The inferred interfacial tensions from MD and QM follow the order of AES > SDBS > SDS > SDSn, which is according with the experimental results. The researches explore the correlation between interfacial tensions and different headgroup structures, and these results maybe have some references for designing of high-efficient surfactant.

  9. Determination of Surface Tension of Surfactant Solutions through Capillary Rise Measurements: An Image-Processing Undergraduate Laboratory Experiment

    Science.gov (United States)

    Huck-Iriart, Cristia´n; De-Candia, Ariel; Rodriguez, Javier; Rinaldi, Carlos

    2016-01-01

    In this work, we described an image processing procedure for the measurement of surface tension of the air-liquid interface using isothermal capillary action. The experiment, designed for an undergraduate course, is based on the analysis of a series of solutions with diverse surfactant concentrations at different ionic strengths. The objective of…

  10. Wire position system to consistently measure and record the location change of girders following ground changes

    Science.gov (United States)

    Choi, H. J.; Lee, S. B.; Lee, H. G.; Y Back, S.; Kim, S. H.; Kang, H. S.

    2017-07-01

    Several parts that comprise the large scientific device should be installed and operated at the accurate three-dimensional location coordinates (X, Y, and Z) where they should be subjected to survey and alignment. The location of the aligned parts should not be changed in order to ensure that the electron beam parameters (Energy 10 GeV, Charge 200 pC, and Bunch Length 60 fs, Emittance X/Y 0.481 μm/0.256 μm) of PAL-XFEL (X-ray Free Electron Laser of the Pohang Accelerator Laboratory) remain stable and can be operated without any problems. As time goes by, however, the ground goes through uplift and subsidence, which consequently deforms building floors. The deformation of the ground and buildings changes the location of several devices including magnets and RF accelerator tubes, which eventually leads to alignment errors (∆X, ∆Y, and ∆Z). Once alignment errors occur with regard to these parts, the electron beam deviates from its course and beam parameters change accordingly. PAL-XFEL has installed the Hydrostatic Leveling System (HLS) to measure and record the vertical change of buildings and ground consistently and systematically and the Wire Position System (WPS) to measure the two dimensional changes of girders. This paper is designed to introduce the operating principle and design concept of WPS and discuss the current situation regarding installation and operation.

  11. Design of a surface deformation measuring instrument for the Surface Tension Driven Convection Experiment (STDCE-2)

    Science.gov (United States)

    Stahl, H. Philip

    1993-01-01

    This final technical report covers the work accomplished (under NAG3-1300) from 1 October 1991 to 1 October 1993. The grant is a direct result of Dr. H. Philip Stahl's (of Rose-Hulman Institute of Technology) participation in the NASA/ASEE Summer Faculty Fellowship Program at NASA Lewis Research Center sponsored by Case Western Reserve University and the Ohio Aerospace Institute. The Surface Tension Driven Convection Experiment (STDCE) is a fundamental fluid physics experiment designed to provide quantitative data on the thermocapillary flow of fluid under the influence of an increased localized surface temperature. STDCE flew on the Space Shuttle Columbia in the First United States Microgravity Laboratory (USML-1) in June 1992. The second flight of this experiment (STDCE-2) is scheduled for 1995. The specific science objectives of STDCE-2 are to determine the extent and nature of thermocapillary flows, the effect of heating mode and level, the effect of the liquid free-surface shape, and the onset conditions for and nature of oscillatory flows. In order to satisfy one of these objectives, an instrument for measuring the shape of an air/oil free surface must be developed.

  12. A Wire Scanner Design for Electron Beam Profile Measurement in the Linac Coherent Light Source Undulator

    CERN Document Server

    Bailey, James L; Yang Bing Xin

    2005-01-01

    The Linac Coherent Light Source (LCLS), currently under design, requires beam diagnostic instruments between the magnets in the beam undulator section. Ten wire scanners are planned as one of the primary instruments to characterize electron beam properties. The development of these wire scanners presents several design challenges due to the need for high accuracy and resolution of the wire motion (3 microns tolerance, typical) and the high intensity of the beam (3400 A over an area of 30 micron rms radius). In this paper, we present the technical specification and design criteria for the scanners. We will also present the mechanical design of the UHV-compatible drive and its engineering analysis. Lastly, we present the wire card design and discuss associated thermal and mechanical issues originating from the highly intense x-ray and electron beams.

  13. Airflow Measurement of the Car HVAC Unit Using Hot-wire Anemometry

    Directory of Open Access Journals (Sweden)

    Fojtlín Miloš

    2016-01-01

    Full Text Available Thermal environment in a vehicular cabin significantly influence drivers’ fatigue and passengers’ thermal comfort. This environment is traditionally managed by HVAC cabin system that distributes air and modifies its properties. In order to simulate cabin thermal behaviour, amount of the air led through car vents must be determined. The aim of this study was to develop methodology to measure airflow from the vents, and consequently calculate corresponding air distribution coefficients. Three climatic cases were selected to match European winter, summer, and spring / fall conditions. Experiments were conducted on a test vehicle in a climatic chamber. The car HVAC system was set to automatic control mode, and the measurements were executed after the system stabilisation—each case was independently measured three times. To be able to evaluate precision of the method, the airflow was determined at the system inlet (HVAC suction and outlet (each vent, and the total airflow values were compared. The airflow was calculated by determining a mean value of the air velocity multiplied by an area of inlet / outlet cross-section. Hot-wire anemometry was involved to measure the air velocity. Regarding the summer case, total airflow entering the cabin was around 57 l s-1 with 60 % of the air entering the cabin through dashboard vents; no air was supplied to the feet compartment. The remaining cases had the same total airflow of around 42 l s-1, and the air distribution was focused mainly on feet and windows. The inlet and outlet airflow values show a good match with a maximum mass differential of 8.3 %.

  14. Airflow Measurement of the Car HVAC Unit Using Hot-wire Anemometry

    Science.gov (United States)

    Fojtlín, Miloš; Planka, Michal; Fišer, Jan; Pokorný, Jan; Jícha, Miroslav

    2016-03-01

    Thermal environment in a vehicular cabin significantly influence drivers' fatigue and passengers' thermal comfort. This environment is traditionally managed by HVAC cabin system that distributes air and modifies its properties. In order to simulate cabin thermal behaviour, amount of the air led through car vents must be determined. The aim of this study was to develop methodology to measure airflow from the vents, and consequently calculate corresponding air distribution coefficients. Three climatic cases were selected to match European winter, summer, and spring / fall conditions. Experiments were conducted on a test vehicle in a climatic chamber. The car HVAC system was set to automatic control mode, and the measurements were executed after the system stabilisation—each case was independently measured three times. To be able to evaluate precision of the method, the airflow was determined at the system inlet (HVAC suction) and outlet (each vent), and the total airflow values were compared. The airflow was calculated by determining a mean value of the air velocity multiplied by an area of inlet / outlet cross-section. Hot-wire anemometry was involved to measure the air velocity. Regarding the summer case, total airflow entering the cabin was around 57 l s-1 with 60 % of the air entering the cabin through dashboard vents; no air was supplied to the feet compartment. The remaining cases had the same total airflow of around 42 l s-1, and the air distribution was focused mainly on feet and windows. The inlet and outlet airflow values show a good match with a maximum mass differential of 8.3 %.

  15. Effect of wall-mounted cylinders on a turbulent boundary layer: hot wire measurements

    Science.gov (United States)

    Ortiz-Dueñas, Cecilia; Ryan, Mitchell; Longmire, Ellen

    2010-11-01

    Wall-mounted cylinders with height-to-diameter ratio H/D = 2 and large enough to protrude into the logarithmic region, H^+= 200, are used to alter a turbulent boundary layer with Reτ=1150 in an attempt to affect the organization of the coherent vortical structures. Hot-wire measurements, including velocity profiles and frequency spectra, were acquired downstream of a single cylinder and spanwise arrays of cylinders. The single cylinder yielded a momentum deficit that extended from z^+=20 to 200, and a redistribution of the streamwise rms velocity towards the half cylinder height with a corresponding increase in the power spectral density over a broad frequency range. Cylinder arrays with 3D spanwise spacing yielded significant wake interactions. The largest mean streamwise velocity deficits and rms values occurred in the log region at mid-span between cylinders. More detail on the effect of cylinder spacing will be provided in the talk. The results suggest that turbulence within the boundary layer leads to broader spanwise interactions than those occurring in wakes of cylinder arrays in uniform cross flow.

  16. Isolated olecranon fractures in children affected by osteogenesis imperfecta type I treated with single screw or tension band wiring system: Outcomes and pitfalls in relation to bone mineral density.

    Science.gov (United States)

    Persiani, Pietro; Ranaldi, Filippo M; Graci, Jole; De Cristo, Claudia; Zambrano, Anna; D'Eufemia, Patrizia; Martini, Lorena; Villani, Ciro

    2017-05-01

    The purpose of this study is to compare the results of 2 techniques, tension band wiring (TBW) and fixation with screws, in olecranon fractures in children affected with osteogenesis imperfecta (OI) type I. Between 2010 and 2014, 21 olecranon fractures in 18 children with OI (average age: 12 years old) were treated surgically. Ten patients were treated with the screw fixation and 11 with TBW. A total of 65% of olecranon fractures occurred as a result of a spontaneous avulsion of the olecranon during the contraction of the triceps muscle. The average follow-up was 36 months. Among the children treated with 1 screw, 5 patients needed a surgical revision with TBW due to a mobilization of the screw. In this group, the satisfactory results were 50%. In patients treated with TBW, the satisfactory results were 100% of the cases. The average Z-score, the last one recorded in the patients before the trauma, was -2.53 in patients treated with screw fixation and -2.04 in those treated with TBW. TBW represents the safest surgical treatment for patients suffering from OI type I, as it helps to prevent the rigidity of the elbow through an earlier recovery of the range of motion, and there was no loosening of the implant. In analyzing the average Z-score before any fracture, the fixation with screws has an increased risk of failure in combination with low bone mineral density.

  17. ROBUST hot wire probe efficiency for total water content measurements in glaciated conditions

    Science.gov (United States)

    Leroy, Delphine; Lilie, Lyle; Weber, Marc; Schwarzenboeck, Alfons; Strapp, J. Walter

    2017-04-01

    During the two High Altitude Ice Crystals (HAIC, Dezitter et al. 2013)/High Ice Water Content (HIWC, Strapp et al., 2016a) international flight campaigns that investigated deep convection in the tropics, the French Falcon 20 research aircraft was equipped with two different devices measuring the Total Water Content (TWC): - the IKP-2 (Isokinetic Probe, Davison et al. 2008, 2016), - and the hot wire ROBUST probe (Strapp et al. 2008; Grandin et al. 2014). The IKP-2 probe is an evaporator that has been specifically designed to measure high ice water content (Strapp et al. 2016b) with a collection efficiency near unity. It has undergone extensive performance assessment in liquid and glaciated conditions in several wind tunnels. The Robust probe was initially developed by Science Engineering Associates to estimate high ice water content in a high speed wind tunnel, in harsh conditions where other hot-wires had been observed to suffer failures. It was known at the outset that, like other hot-wire TWC probes, it would measure only a quasi-constant fraction of the true ice water content. Early wind tunnel and flight experience with the ROBUST probe revealed that this fraction was the order of 40% for ice crystals. During the HAIC/HIWC campaigns (Leroy et al. 2016, 2017), supercooled liquid water conditions were documented according to a detailed analysis of a Rosemount Ice detector (RICE) and a Cloud Droplet Probe (CDP) measurements, and were found to be rare. Thus, the HAIC/HIWC dataset represents a unique opportunity to study in more detail the ROBUST efficiency in glaciated conditions, using the IKP-2 values as a comparative reference. Comparison of IKP-2 and ROBUST measurements will show that the ROBUST behavior differs between low (below 1.5 g/m3) and high (above 2 g/m3) ice content conditions and is also sensitive to temperature. The sensitivity of the ROBUST collection efficiency to ice particles size could also be explored as optical imaging probes were part of the

  18. Investigation of Axial Electric Field Measurements with Grounded-Wire TEM Surveys

    Science.gov (United States)

    Zhou, Nan-nan; Xue, Guo-qiang; Li, Hai; Hou, Dong-yang

    2017-09-01

    The grounded-wire transient electromagnetic (TEM) surveying is often performed along the equatorial direction with its observation lines paralleling to the transmitting wire with a certain transmitter-receiver distance. However, such method takes into account only the equatorial component of the electromagnetic field, and a little effort has been made on incorporating the other major component along the transmitting wire, here denoted as axial field. To obtain a comprehensive understanding of its fundamental characteristics and guide the designing of the corresponding observation system for reliable anomaly detection, this study for the first time investigates the axial electric field from three crucial aspects, including its decay curve, plane distribution, and anomaly sensitivity, through both synthetic modeling and real application to one major coal field in China. The results demonstrate a higher sensitivity to both high- and low-resistivity anomalies by the electric field in axial direction and confirm its great potentials for robust anomaly detection in the subsurface.

  19. A hot-wire probe for thermal measurements of nanowires and nanotubes inside a transmission electron microscope.

    Science.gov (United States)

    Dames, C; Chen, S; Harris, C T; Huang, J Y; Ren, Z F; Dresselhaus, M S; Chen, G

    2007-10-01

    A hot wire probe has been developed for use inside a transmission electron microscope to measure the thermal resistance of individual nanowires, nanotubes, and their contacts. No microfabrication is involved. The probe is made from a platinum Wollaston wire and is pretensioned to minimize the effects of thermal expansion, intrinsic thermal vibrations, and Lorentz forces. An in situ nanomanipulator is used to select a particular nanowire or nanotube for measurement, and contacts are made with liquid metal droplets or by electron-beam induced deposition. Detailed thermal analysis shows that for best sensitivity, the thermal resistance of the hot-wire probe should be four times that of the sample, but a mismatch of more than two orders of magnitude may be acceptable. Data analysis using the ratio of two ac signals reduces the experimental uncertainty. The range of detectable sample thermal resistances spans from approximately 10(3) to 10(9) KW. The probe can also be adapted for measurements of the electrical conductance and Seebeck coefficient of the same sample. The probe was used to study a multiwalled carbon nanotube with liquid Ga contacts. The measured thermal resistance of 3.3 x 10(7) KW had a noise level of approximately +/-3% and was repeatable to within +/-10% upon breaking and re-making the contact.

  20. In-Vivo Measurement of Muscle Tension: Dynamic Properties of the MC Sensor during Isometric Muscle Contraction

    Directory of Open Access Journals (Sweden)

    Srđan Đorđević

    2014-09-01

    Full Text Available Skeletal muscle is the largest tissue structure in our body and plays an essential role for producing motion through integrated action with bones, tendons, ligaments and joints, for stabilizing body position, for generation of heat through cell respiration and for blood glucose disposal. A key function of skeletal muscle is force generation. Non-invasive and selective measurement of muscle contraction force in the field and in clinical settings has always been challenging. The aim of our work has been to develop a sensor that can overcome these difficulties and therefore enable measurement of muscle force during different contraction conditions. In this study, we tested the mechanical properties of a “Muscle Contraction” (MC sensor during isometric muscle contraction in different length/tension conditions. The MC sensor is attached so that it indents the skin overlying a muscle group and detects varying degrees of tension during muscular contraction. We compared MC sensor readings over the biceps brachii (BB muscle to dynamometric measurements of force of elbow flexion, together with recordings of surface EMG signal of BB during isometric contractions at 15° and 90° of elbow flexion. Statistical correlation between MC signal and force was very high at 15° (r = 0.976 and 90° (r = 0.966 across the complete time domain. Normalized SD or σN = σ/max(FMC was used as a measure of linearity of MC signal and elbow flexion force in dynamic conditions. The average was 8.24% for an elbow angle of 90° and 10.01% for an elbow of angle 15°, which indicates high linearity and good dynamic properties of MC sensor signal when compared to elbow flexion force. The next step of testing MC sensor potential will be to measure tension of muscle-tendon complex in conditions when length and tension change simultaneously during human motion.

  1. Applying hot wire anemometry to directly measure the water balance in a proton exchange membrane fuel cell - Part 1

    DEFF Research Database (Denmark)

    Berning, Torsten; Al Shakhshir, Saher

    2015-01-01

    In order to accurately determine the water balance of a proton exchange membrane fuel cell it has recently been suggested to employ constant temperature anemometry (CTA), a frequently used method to measure the velocity of a fluid stream. CTA relies on convective heat transfer around a heated wire...... the equations required to calculate the heat transfer coefficient and the resulting voltage signal as function of the fuel cell water balance. The most critical and least understood part is the determination of the Nusselt number to calculate the heat transfer between the wire and the gas stream. Different...... for all current densities. Therefore, only one curve-fit equation will be required. The voltage curve E0 is an arbitrary calibration curve, and this can be conveniently chosen to be the voltage signal for a dry hydrogen stream at a given temperature and various flow rates which can be easily measured....

  2. Use of electrowetting to measure dynamic interfacial tensions of a microdrop

    NARCIS (Netherlands)

    de Ruiter, Riëlle; Wennink, P.; Banpurkar, A.G.; Duits, Michael H.G.; Mugele, Friedrich Gunther

    2012-01-01

    The adsorption of surface active species to liquid–liquid and to solid–liquid interfaces can have dramatic effects in microfluidics. In this paper we show how electrowetting on dielectric can be used to monitor a dynamic liquid–liquid interfacial tension (IFT) with a time resolution of O(1 s) using

  3. Dynamic surface tension measured with an integrated sensor-actuator using electrolytically generated gas bubbles

    NARCIS (Netherlands)

    Olthuis, Wouter; Volanschi, Alex; Volanschi, A.; Bergveld, Piet

    1998-01-01

    In this paper, a new, simple method to determine dynamic surface tension in aqueous solutions is reported, explained and experimentally verified. By function integration, a small device is obtained. Apart from control and interface electronics no external components or systems are necessary. Instead

  4. New low cost sensing head and taut wire method for automated straightness measurement of machine tool axes

    Science.gov (United States)

    Borisov, Oleg; Fletcher, Simon; Longstaff, Andrew; Myers, Alan

    2013-08-01

    This paper describes a novel method to measure straightness error of an axis of motion with a system utilising taut wire, optical sensor and reference error cancellation technique. In contrast to commonly used taut wire, straightedge or laser-based methods it combines simplicity of setup and low cost with high levels of automation, accuracy and repeatability. An error cancellation technique based on two-point method is applied for the first time to a versatile reference object which can be mounted at any place of machine's working volume allowing direct measurement of motion straightness of a tool point. Experimental results on a typical machine tool validate performance of the proposed taut wire system with a commercial laser interferometer operating in the same conditions is used as a reference. The proposed method shows highly repeatable results of better than ±0.25 μm over the range of 0.48 m and measurement accuracy comparable to the interferometer of ±0.5 μm.

  5. Laplacian drop shapes and effect of random perturbations on accuracy of surface tension measurement for different drop constellations.

    Science.gov (United States)

    Saad, Sameh M I; Neumann, A Wilhelm

    2015-08-01

    Theoretical drop shapes are calculated for three drop constellations: pendant drops, constrained sessile drops, and unconstrained sessile drops. Based on total Gaussian curvature, shape parameter and critical shape parameter are discussed as a function of different drop sizes and surface tensions. The shape parameter is linked to physical parameters for every drop constellation. The as yet unavailable detailed dimensional analysis for the unconstrained sessile drop is presented. Results show that the unconstrained sessile drop shape depends on a dimensionless volume term and the contact angle. Random perturbations are introduced and the accuracy of surface tension measurement is assessed for precise and perturbed profiles of the three drop constellations. It is concluded that pendant drops are the best method for accurate surface tension measurement, followed by constrained sessile drops. The unconstrained sessile drops come last because they tend to be more spherical at low and moderate contact angles. Of course, unconstrained sessile drops are the only option if contact angles are to be measured. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Preventive measures to stop contact wires from icing up; Praeventive Bekaempfung der Fahrdrahtvereisung

    Energy Technology Data Exchange (ETDEWEB)

    Vollrath, Uwe [Kummler und Matter AG (Switzerland). Abt. Engineering Bahn

    2011-07-15

    A combination of low temperatures and air humidity can lead to the accumulation of ice on contact wires in winter. The consequences are arcing, wear on contact elements and costly disruptions to operations. This report provides information on the possibility of taking preventive action to stop ice from forming. (orig.)

  7. Surface Tension

    Science.gov (United States)

    Theissen, David B.; Man, Kin F.

    1996-01-01

    The effect of surface tension is observed inmany everyday situations. For example, a slowly leaking faucet drips because the force surface tension allows the water to cling to it until a sufficient mass of water is accumulated to break free.

  8. Tension Headache

    Science.gov (United States)

    ... your head Tenderness on your scalp, neck and shoulder muscles Tension headaches are divided into two main categories — ... that monitor and give you feedback on body functions such as muscle tension, heart rate and blood pressure. You then ...

  9. Employing Hot Wire Anemometry to Directly Measure the Water Balance in a Proton Exchange membrane Fuel Cell

    DEFF Research Database (Denmark)

    Shakhshir, Saher Al; Hussain, Nabeel; Berning, Torsten

    2015-01-01

    Water management in proton exchange membrane fuel cells (PEMFC’s) remains a critical problem for their durability, cost, and performance. Because the anode side of this fuel cell has the tendency to become dehydrated, measuring the water balance can be an important diagnosis tool during fuel cell...... operation. The water balance indicates how much of the product water leaves at the anode side versus the cathode side. Previous methods of determining the fuel cell water balance often relied on condensing the water in the exhaust gas streams and weighing the accumulated mass which is a time consuming...... process that has limited accuracy. Currently, our group is developing a novel method to accurately determine the water balance in a PEMFC in real time by employing hot-wire anemometry. The amount of heat transferred from the wire to the anode exhaust stream can be translated into a voltage signal which...

  10. Skin tension related to tension reduction sutures.

    Science.gov (United States)

    Hwang, Kun; Kim, Han Joon; Kim, Kyung Yong; Han, Seung Ho; Hwang, Se Jin

    2015-01-01

    The aim of this study was to compare the skin tension of several fascial/subcutaneous tensile reduction sutures. Six upper limbs and 8 lower limbs of 4 fresh cadavers were used. At the deltoid area (10 cm below the palpable acromion) and lateral thigh (midpoint from the palpable greater trochanter to the lateral border of the patella), and within a 3 × 6-cm fusiform area of skin, subcutaneous tissue defects were created. At the midpoint of the defect, a no. 5 silk suture was passed through the dermis at a 5-mm margin of the defect, and the defect was approximated. The initial tension to approximate the margins was measured using a tensiometer.The tension needed to approximate skin without any tension reduction suture (S) was 6.5 ± 4.6 N (Newton). The tensions needed to approximate superficial fascia (SF) and deep fascia (DF) were 7.8 ± 3.4 N and 10.3 ± 5.1 N, respectively. The tension needed to approximate the skin after approximating the SF was 4.1 ± 3.4 N. The tension needed to approximate the skin after approximating the DF was 4.9 ± 4.0 N. The tension reduction effect of approximating the SF was 38.8 ± 16.4% (2.4 ± 1.5 N, P = 0.000 [ANOVA, Scheffé]). The tension reduction effect of approximating the DF was 25.2% ± 21.9% (1.5 ± 1.4 N, P = 0.001 [ANOVA, Scheffé]). The reason for this is thought to be that the SF is located closely to the skin unlike the DF. The results of this study might be a basis for tension reduction sutures.

  11. The effect of a soap film on a catenary: measurement of surface tension from the triangular configuration

    Energy Technology Data Exchange (ETDEWEB)

    Behroozi, F [Department of Physics, University of Northern Iowa, Cedar Falls, IA 50614 (United States); Behroozi, P S, E-mail: behroozi@uni.edu [Department of Physics, Stanford University, Stanford, CA 94305 (United States)

    2011-09-15

    A chain assumes the well-known shape known as a catenary when it hangs loosely from two points in a gravitational field. The correct solution of the catenary was one of the early triumphs of the newly invented calculus of variations at the end of the 17th century. Here we revisit the catenary and show that, for a chain hanging from a horizontal rod, three new and distinct configurations are possible if a soap film covers the area bounded by the chain and the rod. We first review the general problem and discuss the conditions under which the chain assumes a concave, triangular or convex configuration. The deciding factor is the strength of surface tension relative to the gravitational force per unit length of the chain. The conditions under which the chain assumes the shape of a perfect triangle are discussed in greater detail and analysed to obtain the tension along the chain. The triangular configuration is especially intriguing to undergraduates and may be used as a simple experiment to obtain the surface tension of the soap solution by measuring just one angle of the triangle.

  12. Wettability of supercritical carbon dioxide/water/quartz systems: simultaneous measurement of contact angle and interfacial tension at reservoir conditions.

    Science.gov (United States)

    Saraji, Soheil; Goual, Lamia; Piri, Mohammad; Plancher, Henry

    2013-06-11

    Injection of carbon dioxide in deep saline aquifers is considered as a method of carbon sequestration. The efficiency of this process is dependent on the fluid-fluid and rock-fluid interactions inside the porous media. For instance, the final storage capacity and total amount of capillary-trapped CO2 inside an aquifer are affected by the interfacial tension between the fluids and the contact angle between the fluids and the rock mineral surface. A thorough study of these parameters and their variations with temperature and pressure will provide a better understanding of the carbon sequestration process and thus improve predictions of the sequestration efficiency. In this study, the controversial concept of wettability alteration of quartz surfaces in the presence of supercritical carbon dioxide (sc-CO2) was investigated. A novel apparatus for measuring interfacial tension and contact angle at high temperatures and pressures based on Axisymmetric Drop Shape Analysis with no-Apex (ADSA-NA) method was developed and validated with a simple system. Densities, interfacial tensions, and dynamic contact angles of CO2/water/quartz systems were determined for a wide range of pressures and temperatures relevant to geological sequestration of CO2 in the subcritical and supercritical states. Image analysis was performed with ADSA-NA method that allows the determination of both interfacial tensions and contact angles with high accuracy. The results show that supercritical CO2 alters the wettability of quartz surface toward less water-wet conditions compared to subcritical CO2. Also we observed an increase in the water advancing contact angles with increasing temperature indicating less water-wet quartz surfaces at higher temperatures.

  13. Wire chamber

    CERN Multimedia

    1967-01-01

    Magnetoscriptive readout wire chamber.Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  14. Wire Chamber

    CERN Multimedia

    Magnetoscriptive readout wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  15. wire chamber

    CERN Multimedia

    Proportional multi-wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle. Proportional wire chambers allow a much quicker reading than the optical or magnetoscriptive readout wire chambers.

  16. 75 FR 4104 - Prestressed Concrete Steel Wire Strand From China

    Science.gov (United States)

    2010-01-26

    ... suitable for use in prestressed concrete (both pre-tensioned and post- tensioned) applications. The product... COMMISSION Prestressed Concrete Steel Wire Strand From China AGENCY: United States International Trade... concrete steel wire strand, provided for in subheading 7312.10.30 of the Harmonized Tariff Schedule of the...

  17. Experimental setup to detect superconducting wire motion

    OpenAIRE

    K. Ruwali; A. Yamanaka; Y. Teramoto; K. Nakanishi; K. Hosoyama

    2009-01-01

    An experimental setup was designed and fabricated to study superconducting wire motion under the influence of electromagnetic force. Experiments were conducted at 4.2 K by varying the experimental conditions such as the tension to the superconducting wire and different insulating materials at the interface of the superconducting wire and head part. The insulating materials used in the experiments were polyimide film and a high strength polyethylene fiber cloth, Dyneema. Details of the experim...

  18. Surgical Dynamometer to Simultaneously Measure the Tension Forces and the Distance between Wound Edges during the Closure of a Laparotomy.

    Science.gov (United States)

    Roca, Joan; Nogués, Miquel; Villalobos, Rafael; Mías, María Carmen; Comellas, Martí; Gas, Cristina; Olsina, Jorge Juan

    2018-01-11

    The closure of the abdominal wall after making a laparotomy is a major challenge for surgeons, since a significant percentage of closures fail and incisional hernias rise. The suture has to withstand the forces required to close the incision, while not hindering the adequate wound healing progression. Currently, there is no surgical measuring device that could be used to determine the required closing forces, which can be very different depending on the patient. This paper presents a dynamometer to measure the tension forces to be applied while closing a surgical incision, and it simultaneously measures the distance between wound edges. It is a compass-like instrument. A mechanism between the two legs incorporates a load cell, whose signal is read by an electronic device that computes the values of the tension forces between wound edges. An angular position sensor at the pin joint between legs provides the distance between both sides of the incision. Measuring capabilities of the instrument prototype were verified at the laboratory. Thereafter, its functionality was demonstrated in experimental surgery tests. Therefore, the instrument could be very useful in clinical applications, assisting personalized surgical techniques.

  19. Simplified Transient Hot-Wire Method for Effective Thermal Conductivity Measurement in Geo Materials: Microstructure and Saturation Effect

    Directory of Open Access Journals (Sweden)

    B. Merckx

    2012-01-01

    Full Text Available The thermal conductivity measurement by a simplified transient hot-wire technique is applied to geomaterials in order to show the relationships which can exist between effective thermal conductivity, texture, and moisture of the materials. After a validation of the used “one hot-wire” technique in water, toluene, and glass-bead assemblages, the investigations were performed (1 in glass-bead assemblages of different diameters in dried, water, and acetone-saturated states in order to observe the role of grain sizes and saturation on the effective thermal conductivity, (2 in a compacted earth brick at different moisture states, and (3 in a lime-hemp concrete during 110 days following its manufacture. The lime-hemp concrete allows the measurements during the setting, desiccation and carbonation steps. The recorded Δ/ln( diagrams allow the calculation of one effective thermal conductivity in the continuous and homogeneous fluids and two effective thermal conductivities in the heterogeneous solids. The first one measured in the short time acquisitions (<1 s mainly depends on the contact between the wire and grains and thus microtexture and hydrated state of the material. The second one, measured for longer time acquisitions, characterizes the mean effective thermal conductivity of the material.

  20. Modeling, simulation and parametric optimization of wire EDM ...

    African Journals Online (AJOL)

    In the present work, quadratic mathematical models have been derived to represent the process behavior of wire electrical discharge machining (WEDM) operation. Experiments have been conducted with six process parameters: discharge current, pulse duration, pulse frequency, wire speed, wire tension and dielectric flow ...

  1. wire chamber

    CERN Multimedia

    Was used in ISR (Intersecting Storage Ring) split field magnet experiment. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  2. wire chamber

    CERN Multimedia

    1985-01-01

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  3. wire chamber

    CERN Multimedia

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  4. Wire chamber

    CERN Multimedia

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  5. Mortality of sarus cranes (Grus antigone) due to electricity wires in Uttar Pradesh, India

    Energy Technology Data Exchange (ETDEWEB)

    Sundar, K.S.G. [Wildlife Inst. of India, Uttaranchal (India); International Crane Foundation, Baraboo, WI (United States); Choudhury, B.C. [Wildlife Inst. of India, Uttaranchal (India)

    2005-09-15

    Although overhead electrical wires are known to have caused severe declines of bird populations, there are no studies in India that address this danger, even for endangered species. Rates of mortality, factors affecting mortality and population effects of electrical wires on the globally endangered sarus crane (Grus antigone) were assessed for breeding and non-breeding cranes in Etawah and Mainpuri districts, Uttar Pradesh, India. Non-breeding cranes were most susceptible to wires and, within territories, mortalities were higher for pre-dispersed young. Similar proportions of non-breeding and breeding cranes were killed, together accounting for nearly 1% of the total sarus crane population annually. Supply wires accounted for the majority of sarus crane deaths, and only non-breeding cranes were killed by both supply and high-tension power lines. Non-breeding crane deaths at roost sites were correlated with numbers of roosting birds and numbers of wires at each site. Over 40% of 251 known sarus crane territories had at least one overhead wire posing a risk to breeding adults and pre-dispersed young. A risk index for wires over territories of cranes was computed; mortality was not affected by increasing the number and therefore risk posed by wires. Most crane deaths in territories occurred as a result of wires at edges of territories. Wires around roosting sites, territoriality and age of sarus cranes appear to be the most important factors affecting their mortality due to wires. Mitigation measures will be most effective around roost sites and for wires that border territories of breeding pairs. (author)

  6. Intraoperative maximal urethral closing pressure measurement: a new technique of tape tension adjustment in transobturator sling surgery?

    Directory of Open Access Journals (Sweden)

    Myung Beum Kang

    2011-12-01

    Full Text Available PURPOSE: Tape tension adjustment is an essential procedure in mid-urethral sling surgery. The goal of this study was to determine if intraoperative maximal urethral closing pressure (MUCP elevation could be used as a reference value for adequate tape tension adjustment and predict transobturator (TOT sling surgery outcome. MATERIALS AND METHODS: A prospective study was performed using MUCP measurements just before tape insertion and just after tension adjustment during surgery. Clinical data including preoperative urodynamic results were collected. The cure rate was determined by questionnaire. Patients were divided into two groups. The MUCP elevation group included patients with a MUCP elevation of more than 10 cmH2O before tape insertion; the others were regarded as the non-elevation group. The cure rate and pre- and postoperative clinical variables were compared between the two groups. RESULTS: A total of 48 patients had TOT surgery. The MUCP elevation group (n=19 and the non-elevation group (n=29 were similar with regard to patient characteristics and the preoperative parameters including age, mixed incontinence prevalence, Q-tip angle, peak flow rate, MUCP and the valsalva leak point pressure (VLPP. The mean follow-up period was nine months. The cure rate was significantly higher in the group with MUCP elevation than in the non-elevation group (84% vs. 52%, p=0.02. There was no significant difference in the mean postoperative peak flow rate between the two groups and there was no retention episode. CONCLUSIONS: MUCP elevation of more than 10 cmH2O just after tape insertion was a prognostic factor.

  7. Numerical and experimental determination of the minimum and maximum measuring times for the hot wire parallel technique

    Directory of Open Access Journals (Sweden)

    Santos W. N. dos

    2003-01-01

    Full Text Available The hot wire technique is considered to be an effective and accurate means of determining the thermal conductivity of ceramic materials. However, specifically for materials of high thermal diffusivity, the appropriate time interval to be considered in calculations is a decisive factor for getting accurate and consistent results. In this work, a numerical simulation model is proposed with the aim of determining the minimum and maximum measuring time for the hot wire parallel technique. The temperature profile generated by this model is in excellent agreement with that one experimentally obtained by this technique, where thermal conductivity, thermal diffusivity and specific heat are simultaneously determined from the same experimental temperature transient. Eighteen different specimens of refractory materials and polymers, with thermal diffusivities ranging from 1x10-7 to 70x10-7 m²/s, in shape of rectangular parallelepipeds, and with different dimensions were employed in the experimental programme. An empirical equation relating minimum and maximum measuring times and the thermal diffusivity of the sample is also obtained.

  8. Using of fiber-array diagnostic to measure the propagation of fast axial ionization wave during breakdown of electrically exploding tungsten wire in vacuum

    Science.gov (United States)

    Shi, Huantong; Zou, Xiaobing; Wang, Xinxin

    2017-12-01

    The physical process of electrical explosion of wires in vacuum is featured with the surface discharge along the wire, which generates the corona plasma layer and terminates the Joule heating of the wire core. In this paper, a fiber-array probe was designed to directly measure the radiation of surface arc with spatial and temporal resolution. The radiation of the exploding wire was casted to the section of an optical-fiber-array by a lens and transmitted to PIN diodes and finally collected with an oscilloscope. This probe enables direct diagnostics of the evolution of surface discharge with high temporal resolution and certain spatial resolution. The radiation of a tungsten wire driven by a positive current pulse was measured, and results showed that surface discharge initiates near the cathode and propagates toward the anode with a speed of 7.7 ± 1.6 mm/ns; further estimations showed that this process is responsible for the "conical" structure of the exploding wire.

  9. Measurement of the Arithmetic Mean Velocity of a Pulsating Flow of High Velocity by the Hot-Wire Method

    Science.gov (United States)

    1946-04-01

    8217 . . those resulting from the heat $ ransfer chara?-- a" teristics .of the hot..wire ar,eedesired andltiakes it possible, in combination.trith the basid...Wires at Constant-Resistance Operation If constant resistance of the hot- wire, or zero rate of increase of heat energy -in the wire,- dH/dt = 0, is...assumed, the balance of energies supplied to, and dissipated by, the hot wire may be expressed by King’s equation (references 1 and 2). NACA TX

  10. Test Measurements of a 20 ms-1 Carbon Wire Beam Scanner

    CERN Document Server

    De Freitas, J; Emery, J; Herranz Alvarez, J F; Koujili, M; Ramos, D; Sapinski, M; Ait-Amira, Y; Djerdir, A

    2011-01-01

    This paper pre­sents the de­sign of the ac­tu­a­tor for the fast and high ac­cu­ra­cy Wire Scan­ner sys­tem. The ac­tu­a­tor con­sists of a ro­tary brushless syn­chronous motor with the per­ma­nent mag­net rotor in­stalled in­side the vac­u­um cham­ber and the sta­tor in­stalled out­side. The fork, per­ma­nent mag­net rotor and two an­gu­lar po­si­tion sen­sors are mount­ed on the same axis and lo­cat­ed in­side the beam vac­u­um cham­ber. The system has to re­sist a bake-out tem­per­a­ture of 200 C and ion­iz­ing radi­a­tion up to tenths of kGy/year. Max­i­mum wire trav­el­ling speed of 20 m/s and a po­si­tion mea­sure­ment ac­cu­ra­cy of 4 um is re­quired. Therefore, the sys­tem must avoid gen­er­at­ing vi­bra­tion and electromagnet­ic in­ter­fer­ence. A dig­i­tal feed­back con­troller will allow max­i­mum flex­i­bil­i­ty for the loop pa­ram­e­ters and feeds the 3-phase lin­ear power driv­er. The per­for­mance of the pr...

  11. Non-invasive measurement of the mean alveolar O(2) tension from the oxygen uptake versus tidal volume curve.

    Science.gov (United States)

    Jordanoglou, J; Latsi, P; Chroneou, A; Koulouris, N G

    2007-10-01

    The classical equations for measuring the mean and the ideal alveolar O(2) tension are based on assumptions, which are shown to be invalid. So we thought to develop a new, non-invasive method for measuring the mean alveolar P,O(2) within the volume domain (PA,O(2(Bohr))). This method is based on the oxygen uptake vs. tidal volume curve (VO(2) vs. VT) obtained during tidal breathing of room air and/or air enriched with oxygen. PA,O(2(Bohr)) and the ideal alveolar PO(2) (PA,O(2(ideal))) were simultaneously measured in 10 healthy subjects and 34 patients suffering from chronic obstructive pulmonary disease (COPD) breathing tidally room air at rest. Additionally, 10 subjects (three healthy subjects and seven COPD patients) were studied while breathing initially room air and subsequently air enriched with oxygen. According to the results, PA,O(2(Bohr)) considerably differed from PA,O(2(ideal)) (P = 0.004). The cause of the difference, at the individual's R, is: (1) the difference between the arterial and Bohr's alveolar CO(2) tension, mainly in COPD patients, and (2) the inequality between Bohr's alveolar part of the tidal volume for CO(2) and O(2). Furthermore, end-tidal gas tension (PET,CO(2) and PET,O(2)) differed from Pa,CO(2) and PA,O(2(Bohr)) respectively. The deviation of PA,O(2(Bohr)) from PA,O(2(ideal)) has a definite impact on Bohr's dead space ratio for O(2) and CO(2), and on the alveolar-arterial O(2) difference. The difference (PA,O(2(Bohr)) - PA,O(2(ideal))) is not related to the pathology of the disease. So, gas exchange within the lungs should be assessed at the subject's R from PA,O(2(Bohr)) and PA,CO(2(Bohr)) but not from PA,O(2(ideal)) nor Pa,CO(2).

  12. [Comparison of dynamic contour tonometry, Goldmann applanation Tonometry and tonopen for measuring intraocular pressure in normal tension glaucoma].

    Science.gov (United States)

    Kurtz, Shimon; Soiberman, Uri; Shemesh, Gabi

    2013-11-01

    Normal tension glaucoma (NTG) is a chronic progressive optic neuropathy, characterized by relatively normal intraocular pressure (IOP) measurements. This study utilized three modalities in the measurement of lOP: dynamic contour tonometry (Pascal-DCT), Goldmann applanation tonometry (GAT) and Tonopen XL. To compare the lOP measurements of the three devices in eyes with NTG. This retrospective study of thirty-three NTG patients (66 eyes) who underwent lOP measurements using the three devices was approved by a local ethics committee. The lOP measurements were stratified according to central corneal thickness (CCT) and corneal curvature (CC). The mean DCT IOP was higher (16.22 +/- 3.04 mmHg) than the mean GAT IOP (13.14 +/- 2.83 mmHg, P IOP (12.76 +/- 3.11 mmHg, P measurements were significantly infLuenced by corneal curvature (P = 0.004 and P measured by GAT or Tonopen XL were consistently lower than by DCT. CC significantly influenced GAT and DCT results.

  13. AC loss measurement of transposed / twister Ag-sheathed Bi round wires; Fuiramentosoku ni yori{center_dot}ten'i wo hodokoshita bisumasu kei marugata gin shisu chodendo senzai no koryu sonshitsu sokutei

    Energy Technology Data Exchange (ETDEWEB)

    Amemiya, N.; Torii, M. [Yokohama National Univ., Kanagawa (Japan). Faculty of Engineering; Sasaoka, T. [Hitachi Cable, Ltd., Tokyo (Japan)

    2000-05-29

    In superconductive wire of bismuth system, tape wire is main usage, but in the case of conductor for large current, round wire with assembles of twisted wire is advantageous. Transport loss and magnetization loss of pure Ag-sheathed Bi-2212 superconductive round wire was measured. This structure is one where three first filaments with fan type consisting of 54 filaments were bundled with second twisted structure. Transport loss of filament bundle was near Norris theoretical value regardless of transposition. It was confirmed from magnetization loss that loss by transverse field decreased by breaking of association of filaments and filament bundles. (NEDO)

  14. Measurement of AC losses in superconducting wires under external transverse magnetic field; Chodendo senzai no gaibu yoko jikai ka ni okeru koryu sonshitsu sokutei

    Energy Technology Data Exchange (ETDEWEB)

    Kakiuchi, T.; Arakawa, K.; Kawabata, S.; Sumiyoshi, F. [Kagoshima Univ., Kagoshima (Japan)

    2000-05-29

    The quantitative evaluation of ac loss characteristics of the superconducting wire material is very important, when little-loss design of the superconducting wire rod and application to the superconductive equipment are considered. Though in the case of this loss measurement in the pick-up coil method, the solenoidal coil state does the winding of the material wire rod, the loss characteristic measured by the interaction between winding changes, when coil shape such as roll pitch and number of layers of the sample coil change. Then, the purpose of this study is to clarify the effect of the shape of the sample coil to the loss characteristic in loss measurement under the outside transverse field by the pick-up coil method. (NEDO)

  15. Measurement of Flow Distribution at Subchannels in a Wire-Wrapped 37-Rod Bundle for a Sodium Cooled Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, HYungmo; Chang, Seokkyu; Lee, Dong Won; Choi, Hae Seob; Euh, Dongjin; Lee, Hyeongyeon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    In this SFR type of fuel rod, core subchannels are classified with interior, edge, and corner subchannels. Flow distribution of each subchannel is a crucial factor for the core thermal design, and experimental tests for the design code verification and validation in a temperature limitation analysis were conducted. To verify and validate computer codes for the SFR core thermal design, a hexagonally arrayed 37-pin wire-wrapped fuel rod bundle test section was fabricated. The measurement experiments were conducted using a well- designed test loop and iso-kinetic sampling probe. The developed iso-kinetic sampling method in the present study has its own merits, and flow rate results by sampling showed in good agreement with the preliminary CFD analysis results. In addition, the estimated mass balance error was only about 3% in the experiments. Therefore, the present methodology and results can be used in future experiments for design code verification and validation.

  16. STRENGTHENING OF A REINFORCED CONCRETE BRIDGE WITH PRESTRESSED STEEL WIRE ROPES

    Directory of Open Access Journals (Sweden)

    Kexin Zhang

    2017-10-01

    Full Text Available This paper describes prestressed steel wire ropes as a way to strengthen a 20-year-old RC T-beam bridge. High strength, low relaxation steel wire ropes with minor radius, high tensile strain and good corrosion resistance were used in this reinforcement. The construction process for strengthening with prestressed steel wire ropes—including wire rope measuring, extruding anchor heads making, anchorage installing, tensioning steel wire ropes and pouring mortar was described. Ultimate bearing capacity of the bridge after strengthening was discussed based on the concrete structure theory. The flexural strength of RC T-beam bridges strengthened with prestressed steel wire ropes was governed by the failure of concrete crushing. To investigate effectiveness of the strengthening method, fielding-load tests were carried out before and after strengthening. The results of concrete strain and deflection show that the flexural strength and stiffness of the strengthened beam are improved. The crack width measurement also indicates that this technique could increase the durability of the bridge. Thus, this strengthened way with prestressed steel wire rope is feasible and effective.

  17. Humidity-dependent surface tension measurements of individual inorganic and organic submicrometre liquid particles† †Electronic supplementary information (ESI) available: SEM image of AFM nanoneedles, force plot data from bulk AFM surface tension, data used for surface tension vs. RH predictions, comparison of AIM and bulk predictions for NaCl. See DOI: 10.1039/c4sc03716b Click here for additional data file.

    Science.gov (United States)

    Morris, Holly S.

    2015-01-01

    Surface tension, an important property of liquids, is easily measured for bulk samples. However, for droplets smaller than one micron in size, there are currently no reported measurements. In this study, atomic force microscopy (AFM) and force spectroscopy have been utilized to measure surface tension of individual submicron sized droplets at ambient pressure and controlled relative humidity (RH). Since the surface tension of atmospheric aerosols is a key factor in understanding aerosol climate effects, three atmospherically relevant systems (NaCl, malonic and glutaric acids) were studied. Single particle AFM measurements were successfully implemented in measuring the surface tension of deliquesced particles on the order of 200 to 500 nm in diameter. Deliquesced particles continuously uptake water at high RH, which changes the concentration and surface tension of the droplets. Therefore, surface tension as a function of RH was measured. AFM based surface tension measurements are close to predicted values based on bulk measurements and activities of these three chemical systems. Non-ideal behaviour in concentrated organic acid droplets is thought to be important and the reason for differences observed between bulk solution predictions and AFM data. Consequently, these measurements are crucial in order to improve atmospheric climate models as direct measurements hitherto have been previously inaccessible due to instrument limitations. PMID:28706693

  18. Measurement of Prestressing Force in Pretensioned UHPC Deck Using a Fiber Optic FBG Sensor Embedded in a 7-Wire Strand

    Directory of Open Access Journals (Sweden)

    Jae-min Kim

    2016-01-01

    Full Text Available This paper presents the results of the performance test and long-term monitoring of the prestressing force inside concrete performed on a pretensioned Ultra-High Performance Concrete (UHPC deck. The force is measured by applying a 7-wire strand embedded with an FBG (Fiber Bragg Grating sensor. The performance test was conducted on a 3.7 m × 1.8 m pretensioned deck specimen through wheel loading tests to verify the applicability of the measurement method. In addition, a 12.3 m long and 4.8 m wide bridge with a pretensioned UHPC deck was erected and long-term monitoring was conducted over three years to verify the applicability of the method to real bridges. The effectiveness of the measurement method of the prestressing force inside concrete is verified, and the long-term monitoring data are used to investigate various temperature compensation methods. The results show that the proposed method enables effective measurement of small changes in the prestressing force inside the concrete. These changes are caused by the external forces acting on the bridge in service and provide sufficient durability for long-term sensing. The analysis of the prestressing force obtained through long-term monitoring reveals the necessity of conducting temperature compensation for the consistency of the data acquired using the FBG sensor. Moreover, the selection of the thermal expansion coefficient appears also to be of critical importance for temperature compensation.

  19. Measurement of local strain and heat propagation during high-temperature testing in a split-Hopkinson tension bar system

    Directory of Open Access Journals (Sweden)

    Børvik T.

    2012-08-01

    Full Text Available Aluminium alloys are commonly used by the industry due to their good mechanical properties and their relatively low density. An accurate prediction of the behaviour of aluminium alloys under a wide range of temperatures and strain rates is important in numerical simulations of forming processes or applications involving adiabatic heating like penetration and crash situations. Several tests are needed at low, medium and high strain rates to study this behaviour. This paper will focus on the high strain rate test rig, which is a split- Hopkinson tension bar system (SHTB, the acquisition system for strain measurements, and a thermal analysis of the bars due to heating of the sample. A new way of doing local measurements with a high-speed camera will be presented. The thermal boundary conditions of the tests have been measured and simulated, and the results indicate that the stress wave propagation in the bars is not significantly affected by a local heating of the part of the bars which is closest to the sample.

  20. Functional in vitro tension measurements of fascial tissue ? a novel modified superfusion approach

    OpenAIRE

    Schleip, R.; Klingler, W.; Wearing, S; Naylor, I.; Zuegel, M.; Hoppe, K. (Kai)

    2016-01-01

    Introduction: While two laboratory techniques are commonly used to assess the tensile properties of muscle tissue, emerging evidence suggests that the fascial components of these tissues also serve an active role in force generation. Hence, we investigated whether these techniques are sensitive for assessment of fascial micromechanics. Methods: Force measurements on dissected fascial tissue were performed either using the classical immersion organ bath or using an improved superfusion approac...

  1. Design and Development of Embedded System for the Measurement of Thermal Conductivity of Liquids by Transient Hot Wire Method

    Directory of Open Access Journals (Sweden)

    Nagamani GOSALA

    2011-06-01

    Full Text Available Thermal conductivity of polymers is an important property for both polymer applications and processing industry. The successful application of thermal insulating fluids in the last several years has demonstrated that such fluids can effectively control the heat loss. Understanding and controlling the thermal environment for oilfield operations has been a concern and research topic. As a consequence of this trend, there is huge demand for new methods of instrumentation to evaluate the performance of material properties and characterization. The main aim of the present study is the development of hardware and software for measuring the thermal conductivity of liquids using transient hot wire method. Because of the relatively short experimental times and large amounts of parametric data involved in the measurement process, embedded control of the measurement is essential. The experimental implementation requires a suitable temperature sensing, automatic control, data acquisition, and data analysis systems accomplished using an embedded system that has been built around the ARM LPC 2103 mixed signal controller.

  2. Measurement of Density, Sound Velocity, Surface Tension, and Viscosity of Freely Suspended Supercooled Liquids

    Science.gov (United States)

    Trinh, E. H.

    1995-01-01

    Non-contact methods have been implemented in conjunction with levitation techniques to carry out the measurement of the macroscopic properties of liquids significantly cooled below their nominal melting point. Free suspension of the sample and remote methods allow the deep excursion into the metastable liquid state and the determination of its thermophysical properties. We used this approach to investigate common substances such as water, o-terphenyl, succinonitrile, as well as higher temperature melts such as molten indium, aluminum and other metals. Although these techniques have thus far involved ultrasonic, electromagnetic, and more recently electrostatic levitation, we restrict our attention to ultrasonic methods in this paper. The resulting magnitude of maximum thermal supercooling achieved have ranged between 10 and 15% of the absolute temperature of the melting point for the materials mentioned above. The physical properties measurement methods have been mostly novel approaches, and the typical accuracy achieved have not yet matched their standard equivalent techniques involving contained samples and invasive probing. They are currently being refined, however, as the levitation techniques become more widespread, and as we gain a better understanding of the physics of levitated liquid samples.

  3. Finite element analysis on the wire breaking rule of 1×7IWS steel wire rope

    Directory of Open Access Journals (Sweden)

    Wenzheng Du

    2017-01-01

    Full Text Available Taking the wire rope of 1×7+IWS structure as the research object, the influences of the number of broken wires on the stress distribution under the same axial load were simulated and analysed, and it also explored the rule of wire breaking of steel wire ropes. Based on the SolidWorks software, the three-dimensional model of the wire rope was established. Importing the model into the ABAQUS, the finite element model of the steel wire rope was established. Firstly 5000 N axial tension was placed on the rope, the stress distribution was simulated and analysed, and the steel wire with the largest stress distribution was found out. Then one steel wire was truncated with the load unchanged, and the finite element simulation was carried out again, and repeated the steps several times. The results show that, with the increase of the number of broken wires, the Von-Mises stress of the wire rope increases sharply, and the stress distribution is concentrated on the rest of the unbroken wires, which brings great challenges to the safety of the wire rope.

  4. Enhanced Strain Measurement Range of an FBG Sensor Embedded in Seven-Wire Steel Strands

    Directory of Open Access Journals (Sweden)

    Jae-Min Kim

    2017-07-01

    Full Text Available FBG sensors offer many advantages, such as a lack of sensitivity to electromagnetic waves, small size, high durability, and high sensitivity. However, their maximum strain measurement range is lower than the yield strain range (about 1.0% of steel strands when embedded in steel strands. This study proposes a new FBG sensing technique in which an FBG sensor is recoated with polyimide and protected by a polyimide tube in an effort to enhance the maximum strain measurement range of FBG sensors embedded in strands. The validation test results showed that the proposed FBG sensing technique has a maximum strain measurement range of 1.73% on average, which is 1.73 times higher than the yield strain of the strands. It was confirmed that recoating the FBG sensor with polyimide and protecting the FBG sensor using a polyimide tube could effectively enhance the maximum strain measurement range of FBG sensors embedded in strands.

  5. Functional in vitro tension measurements of fascial tissue – a novel modified superfusion approach

    Science.gov (United States)

    Schleip, R.; Klingler, W.; Wearing, S.; Naylor, I.; Zuegel, M.; Hoppe, K.

    2016-01-01

    Introduction: While two laboratory techniques are commonly used to assess the tensile properties of muscle tissue, emerging evidence suggests that the fascial components of these tissues also serve an active role in force generation. Hence, we investigated whether these techniques are sensitive for assessment of fascial micromechanics. Methods: Force measurements on dissected fascial tissue were performed either using the classical immersion organ bath or using an improved superfusion approach simulating pulsed pharmacological triggers. Rat deep dorsal fascial strips as well as rat testicular capsule were pharmacologically challenged either with mepyramine or oxytocin. Results: The classical immersion technique yielded a lower force response to mepyramine than the superfusion method (median: 367.4 vs. 555.4µN/mm2). Pause in irrigation before application reduced irregularities during bolus application. The superfusion approach was improved further by the following points: The high sensitivity of the superfusion method to bolus addition was voided by deviation of fluid supply during bolus addition. Conclusion: Although both methods demonstrated pharmacologically induced contractile responses in lumbar fascia samples, the modified superfusion method may improve force registrations of slow contracting fascial tissue and minimize artefacts of fluid application. PMID:27609040

  6. Functional in vitro tension measurements of fascial tissue - a novel modified superfusion approach.

    Science.gov (United States)

    Schleip, R; Klingler, W; Wearing, S; Naylor, I; Zuegel, M; Hoppe, K

    2016-09-07

    While two laboratory techniques are commonly used to assess the tensile properties of muscle tissue, emerging evidence suggests that the fascial components of these tissues also serve an active role in force generation. Hence, we investigated whether these techniques are sensitive for assessment of fascial micromechanics. Force measurements on dissected fascial tissue were performed either using the classical immersion organ bath or using an improved superfusion approach simulating pulsed pharmacological triggers. Rat deep dorsal fascial strips as well as rat testicular capsule were pharmacologically challenged either with mepyramine or oxytocin. The classical immersion technique yielded a lower force response to mepyramine than the superfusion method (median: 367.4 vs. 555.4µN/mm(2)). Pause in irrigation before application reduced irregularities during bolus application. The superfusion approach was improved further by the following points: The high sensitivity of the superfusion method to bolus addition was voided by deviation of fluid supply during bolus addition. Although both methods demonstrated pharmacologically induced contractile responses in lumbar fascia samples, the modified superfusion method may improve force registrations of slow contracting fascial tissue and minimize artefacts of fluid application.

  7. The interfacial tension of the mercury —1 M HClO4− solution interface at high potentials; comparison with double-layer capacitance measurements

    NARCIS (Netherlands)

    Sluyters-Rehbach, M.; Woittiez, W.J.A.; Sluyters, J.H.

    Interfacial tension values have been measured in order to calculate the electrical charge density as a function of potential. The results are in accordance with those obtained from double-layer capacitance data reported earlier2,3, also at highly positive potentials.

  8. Measurements of high-current electron beams from X pinches and wire array Z pinches.

    Science.gov (United States)

    Shelkovenko, T A; Pikuz, S A; Blesener, I C; McBride, R D; Bell, K S; Hammer, D A; Agafonov, A V; Romanova, V M; Mingaleev, A R

    2008-10-01

    Some issues concerning high-current electron beam transport from the X pinch cross point to the diagnostic system and measurements of the beam current by Faraday cups are discussed. Results of computer simulation of electron beam propagation from the pinch to the Faraday cup give limits for the measured current for beams having different energy spreads. The beam is partially neutralized as it propagates from the X pinch to a diagnostic system, but within a Faraday cup diagnostic, space charge effects can be very important. Experimental results show evidence of such effects.

  9. Hot Wire Anemometer Turbulence Measurements in the wind Tunnel of LM Wind Power

    DEFF Research Database (Denmark)

    Fischer, Andreas

    Flow measurements were carried out in the wind tunnel of LM Wind Power A/S with a Dantec Streamline CTA system to characterize the flow turbulence. Besides the free tunnel flow with empty test section we also investigated the tunnel flow when two grids with different mesh size were introduced...... measured with the triple sensor probe. The turbulence intensity as well as the mean flow velocity downstream of the grids were not homogeneous in space. The grid with the finer mesh size created higher turbulence intensity. For both grids we found a functional form of the power spectral density...

  10. Social and environmental tensions

    DEFF Research Database (Denmark)

    Saito, Moeko; Rutt, Rebecca Leigh; Chhetri, Bir Bahadur Khanal

    2014-01-01

    to forests. Our case highlights the risk that the mere application of affirmative measures may give rise to difficult social and environmental tensions. Thus, this paper calls for such measures to effectively incorporate local perspectives in their designs and to be reflective, by allowing for regular...

  11. The Influence of Surface Tension Gradients on Surfactant Tracer Measurement of Air-Water Interfacial Area in Porous Media

    Science.gov (United States)

    Costanza-Robinson, M. S.; Estabrook, B. D.; Henry, E. J.

    2009-12-01

    Air-water interfacial area (AI) in porous media is an important factor governing equilibrium contaminant retention, as well as the kinetics of interphase mass transfer, such as delivery of oxygen to roots and volatilization of methane from landfills. Despite this importance, significant method-dependence is observed among techniques used to determine AI in porous media. In this work, possible low bias in conventional aqueous interfacial-partitioning tracer methodology (IPT) was examined by comparison of IPT-AI estimates with more direct estimates obtained using synchrotron X-ray microtomographic (µCT) imaging. Sodium dodecyl benzene sulfonate and pentafluorobenzoate were used as interfacial and nonreactive tracers, respectively, to measure AI at three water saturations (Sw) in a natural fine sand. IPT-AI exhibited expected trends, with higher areas associated with drier conditions, but the magnitude of AI was as much as 50% lower than those measured by µCT. IPT-AI values for the driest system agreed most closely with microtomography data. Real-time system mass measurements revealed that upon introduction of the surfactant tracer, system Sw decreased by 15-30%; the driest system exhibited the least drainage. This drainage is consistent with a reduction in capillarity caused by the lower surface tension of the surfactant solution as compared to the surfactant-free resident fluid. Drainage in the direction of flow would lead to earlier breakthrough of the surfactant tracer and a lower AI-estimate. In fact, the magnitude of drainage and magnitude of AI-underestimation relative to µCT were qualitatively correlated. Although this effect was expected, its magnitude and potential influence on AI was previously unknown and was larger than anticipated.

  12. Insulation-resistance measurements of coated and uncoated printed wiring boards

    Science.gov (United States)

    Jennings, C. W.

    1983-06-01

    Insulation resistance (IR) was measured between narrow spaced conductors on different types of printed circuit boards with and without polymer coatings. Measurement environments consisted of thermal cycling in a humid environment per MIL-STD-202/106, and room temperature with 5 to 100 percent relative humidity (R.H.). The variability of the IR of test patterns both within a board and between boards with the same coating, and the lack of consistent resistivity values, suggest that the measured IR in these environments is not inherent to the materials, but is related to the contaminates present on and in the materials. There was little difference in IR for different conformal coatings or laminate types or sources. Although the IR was found to increase significantly when a board was conformally coated, there was no coating type tested which could ensure a high IR. Porcelain enamel and multiwire boards had lowers IR than conventional circuit boards. An association was observed between low IR and the tendency for dendritic filament formation between conductors in a 100 percent R.H. environment.

  13. Comparison between Neutron Diffraction measurements and numerical simulation of residual stresses of a Wire-Drawing process

    Directory of Open Access Journals (Sweden)

    Tomaz Fantin de Souza

    2013-04-01

    Full Text Available In this work, a drawing processed was simulated to calculate forces and the resulting residual stresses in the material. The calculated residual stresses were compared with experimentally measured residual stresses by the Neutron Diffraction Method. The modeled process was the Wire Drawing. The necessary parameters to model the process were taken from an industrial currently used process. Rods of an AISI 1045 steel with nominal diameters of 21.46 mm were reduced to 20.25 mm by drawing with an drawing angle of 15°. Compression tests were used to determinate flow curves of the real material an used in the simulation models. The possibility to estimate drawing forces by numerical simulation was evaluated by comparing simulated results with values from empirical equations given by the literature. The results have shown a sufficient accuracy for the calculation of forces, but the comparison of residual stresses has shown differences to the experimentally determined ones that can be minimized by the consideration of high strain rates in the compression tests, anisotropy of the material and kinematic hardening.

  14. Hot-wire measurements of a single lateral jet injected into swirling crossflow

    Science.gov (United States)

    Lilley, D. G.; Ong, L. H.; Mcmurry, C. B.

    1986-01-01

    In the present experiments documenting the time-mean and turbulent flowfield of a deflected turbulent jet in a combined, swirling crossflow, attention is given to a jet-to-crossflow velocity ratio of 4 at swirler vane angles of 45 and 70 deg. The results obtained are presented in the form of r-x plots in order to aid in three-dimensional flowfield visualization. The time-mean velocity measurements were found to closely correspond to pitot-probe data obtained in identical flow conditions. The lateral jet was found to deflect the axis of the precessing vortex core.

  15. Experimental setup to detect superconducting wire motion

    Science.gov (United States)

    Ruwali, K.; Yamanaka, A.; Teramoto, Y.; Nakanishi, K.; Hosoyama, K.

    2009-04-01

    An experimental setup was designed and fabricated to study superconducting wire motion under the influence of electromagnetic force. Experiments were conducted at 4.2 K by varying the experimental conditions such as the tension to the superconducting wire and different insulating materials at the interface of the superconducting wire and head part. The insulating materials used in the experiments were polyimide film and a high strength polyethylene fiber cloth, Dyneema. Details of the experimental setup and the test results are reported in this paper.

  16. Experimental setup to detect superconducting wire motion

    Directory of Open Access Journals (Sweden)

    K. Ruwali

    2009-04-01

    Full Text Available An experimental setup was designed and fabricated to study superconducting wire motion under the influence of electromagnetic force. Experiments were conducted at 4.2 K by varying the experimental conditions such as the tension to the superconducting wire and different insulating materials at the interface of the superconducting wire and head part. The insulating materials used in the experiments were polyimide film and a high strength polyethylene fiber cloth, Dyneema. Details of the experimental setup and the test results are reported in this paper.

  17. The Fluctuation of Intraocular Pressure Measured by a Contact Lens Sensor in Normal-Tension Glaucoma Patients and Nonglaucoma Subjects.

    Science.gov (United States)

    Tojo, Naoki; Abe, Shinya; Ishida, Masaaki; Yagou, Takaaki; Hayashi, Atsushi

    2017-03-01

    We compared the fluctuation of intraocular pressure (IOP) in normal-tension glaucoma (NTG) patients and individuals with nonglaucoma eyes. We obtained continuous IOP values using a SENSIMED Triggerfish contact lens sensor. The eyes of 12 nonglaucoma subjects and 14 NTG patients were examined. In all 26 subjects, the IOP fluctuation was measured continuously for 24 hours with a contact lens sensor. We evaluated the range of IOP fluctuations over the 24-hour period separately for diurnal IOP and nocturnal IOP and identified each subject's maximum value. The range of IOP fluctuation were analyzed, cutoff level of IOP fluctuation was calculated using receiver operating characteristic curve analyses. The mean IOP in the NTG eyes was 11.5±2.4 mm Hg and that in the nonglaucoma eyes was 12.7±2.0 mm Hg, a nonsignificantly difference (P=0.175). The 24-hour range of IOP fluctuations in the NTG group was significantly larger than that of the nonglaucoma group (P=0.007). The percentage of NTG patients who had the peak time of IOP fluctuation during nocturnal sleep was 57.1%, whereas the corresponding rate for the nonglaucoma eyes was 91.7%. The cutoff level of IOP fluctuation for glaucoma was 442 mVeq (sensitivity=1.00; specificity=0.571). The range of IOP fluctuation was larger in the eyes with NTG than in the nonglaucoma eyes. This larger fluctuation might be one of the reasons underlying the aggravation of the visual field by NTG. Measurements of 24-hour continuous IOP might be one of the useful methods to distinguish NTG from nonglaucoma eyes.

  18. Tension band fixation of medial malleolus fractures.

    Science.gov (United States)

    Ostrum, R F; Litsky, A S

    1992-01-01

    A prospective study on tension band fixation of medial malleolus fractures was performed on 30 consecutive patients with 31 fractures from October 1987 until December 1990. All patients had at least a displaced medial malleolus fracture unreduced by closed methods. The fractures were classified into small, medium and large using a modified Lauge-Hansen classification. There were no nonunions or movements of wires postoperatively and only two patients had subjective complaints with reference to the wires that required hardware removal. There was one 2-mm malreduction and one patient with a wound slough and subsequent osteomyelitis. One fragment had 2 mm of displacement after fixation but went on to union. A biomechanical study was undertaken to compare fixation of the medial malleolus with K wires alone, K wires plus a tension band, and two cancellous screws. The tension band fixation provided the greatest resistance to pronation forces: for times stiffer than the two screws and 62% of the intact specimen. Tension band fixation of the medial malleolus is a biomechanically strong and clinically acceptable method of treatment for displaced medial malleolus fractures. This method of fixation may be especially useful for small fragments and in osteoporotic bone.

  19. Surface tensions of multi-component mixed inorganic/organic aqueous systems of atmospheric significance: measurements, model predictions and importance for cloud activation predictions

    Directory of Open Access Journals (Sweden)

    D. O. Topping

    2007-01-01

    Full Text Available In order to predict the physical properties of aerosol particles, it is necessary to adequately capture the behaviour of the ubiquitous complex organic components. One of the key properties which may affect this behaviour is the contribution of the organic components to the surface tension of aqueous particles in the moist atmosphere. Whilst the qualitative effect of organic compounds on solution surface tensions has been widely reported, our quantitative understanding on mixed organic and mixed inorganic/organic systems is limited. Furthermore, it is unclear whether models that exist in the literature can reproduce the surface tension variability for binary and higher order multi-component organic and mixed inorganic/organic systems of atmospheric significance. The current study aims to resolve both issues to some extent. Surface tensions of single and multiple solute aqueous solutions were measured and compared with predictions from a number of model treatments. On comparison with binary organic systems, two predictive models found in the literature provided a range of values resulting from sensitivity to calculations of pure component surface tensions. Results indicate that a fitted model can capture the variability of the measured data very well, producing the lowest average percentage deviation for all compounds studied. The performance of the other models varies with compound and choice of model parameters. The behaviour of ternary mixed inorganic/organic systems was unreliably captured by using a predictive scheme and this was dependent on the composition of the solutes present. For more atmospherically representative higher order systems, entirely predictive schemes performed poorly. It was found that use of the binary data in a relatively simple mixing rule, or modification of an existing thermodynamic model with parameters derived from binary data, was able to accurately capture the surface tension variation with concentration. Thus

  20. Emittance growth due to Tevatron flying wires

    Energy Technology Data Exchange (ETDEWEB)

    Syphers, M; Eddy, Nathan

    2004-06-01

    During Tevatron injection, Flying Wires have been used to measure the transverse beam size after each transfer from the Main Injector in order to deduce the transverse emittances of the proton and antiproton beams. This amounts to 36 + 9 = 45 flies of each of 3 wire systems, with an individual wire passing through each beam bunch twice during a single ''fly''. below they estimate the emittance growth induced by the interaction of the wires with the particles during these measurements. Changes of emittance from Flying Wire measurements conducted during three recent stores are compared with the estimations.

  1. Light Scattering by Surface Tension Waves.

    Science.gov (United States)

    Weisbuch, G.; Garbay, F.

    1979-01-01

    This simple and inexpensive experiment is an illustration of the physical concepts of interaction between light and surface tension waves, and provides a new method of measuring surface tension. (Author/GA)

  2. Ion distributions at the water/1,2-dichloroethane interface: potential of mean force approach to analyzing X-ray reflectivity and interfacial tension measurements.

    Science.gov (United States)

    Hou, Binyang; Laanait, Nouamane; Yu, Hao; Bu, Wei; Yoon, Jaesung; Lin, Binhua; Meron, Mati; Luo, Guangming; Vanysek, Petr; Schlossman, Mark L

    2013-05-02

    We present X-ray reflectivity and interfacial tension measurements of the electrified liquid/liquid interface between two immiscible electrolyte solutions for the purpose of understanding the dependence of interfacial ion distributions on the applied electric potential difference across the interface. The aqueous phase contains alkali-metal chlorides, including LiCl, NaCl, RbCl, or CsCl, and the organic phase is a 1,2-dichloroethane solution of bis(triphenylphosphor anylidene) ammonium tetrakis(pentafluorophenyl)borate (BTPPATPFB). Selected data for a subset of electric potential differences are analyzed to determine the potentials of mean force for Li(+), Rb(+), Cs(+), BTPPA(+), and TPFB(-). These potentials of mean force are then used to analyze both X-ray reflectivity and interfacial tension data measured over a wide range of electric potential differences. Comparison of X-ray reflectivity data for strongly hydrated alkali-metal ions (Li(+) and Na(+)), for which ion pairing to TPFB(-) ions across the interface is not expected, to data for weakly hydrated alkali-metal ions (Rb(+) and Cs(+)) indicates that the Gibbs energy of adsorption due to ion pairing at the interface must be small (X-ray reflectivity measurements that probe the nanoscale ion distribution and the consequences of these underlying distributions for thermodynamic studies, such as interfacial tension measurements, that yield quantities related to the integrated ion distribution.

  3. Time and space resolved measurement of the electron temperature, mass density and ionization state in the ablation plasma between two exploding Al wires

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, P. F.; Pikuz, S. A.; Shelkovenko, T. A.; Hammer, D. A. [Laboratory of Plasma Studies, Cornell University, 439 Rhodes Hall, Ithaca, New York 14853 (United States); Hansen, S. B. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

    2012-05-15

    We have determined the properties of plasma around and between two exploding wires using high-resolution x-ray absorption spectroscopy. Plasma densities and temperatures ranging from Greater-Than-Or-Equivalent-To 0.1g/cm{sup 3} and a few eV to less than 0.01 g/cm{sup 3} and 30 eV have been measured in experiments at Cornell University with two 40 {mu}m aluminum (Al) wires spaced 1 mm apart driven by {approx}150 kA peak current pulses with 100 ns rise time. The wire plasma was backlit by the 1.4-1.6 keV continuum radiation produced by a Mo wire X-pinch. The spectrometer employed two spherically bent quartz crystals to record the absorption and backlighter spectra simultaneously. The transition between the dense Al wire core and the coronal plasma is seen as a transition from cold K-edge absorption to Mg-, Na-, and finally Ne-like absorption at the boundary. In the plasma that accumulates between the wires, ionization states up to C-Like Al are observed. The spectrometer geometry and {approx}2{mu}m X-pinch source size provide 0.3 eV spectral resolution and 20 {mu}m spatial resolution enabling us to see 1s{yields} 2p satellite transitions as separate lines as well as O-, F-, and Ne-like 1s{yields} 3p transitions that have not been seen before. A step wedge was used to calibrate the transmission, enabling density to be measured within a factor of two and temperature to be measured within {+-}25%. A genetic algorithm was developed to fit synthetic spectra calculated using the collisional-radiative code SCRAM to the experimental spectra. In order to obtain agreement it was necessary to assume multiple plasma regions with variable thicknesses, thereby allowing the inferred plasma conditions to vary along the absorption path.

  4. Signal shapes in a TPC wire chamber

    Science.gov (United States)

    Rossegger, S.; Riegler, W.

    2010-11-01

    We study signal shapes in Multi Wire Proportional Chambers (MWPCs) and the influence of the electron distribution around the wire on the ion tail characteristics. Simulations of the ion tail for two different geometries, different voltages and therefore gas gains were performed. These simulations are compared to measurements carried out with the ALICE TPC wire chambers for a Ne/CO 2/N 2 gas mixture, which allows to extract the avalanche spread around the anode wires of the MWPC.

  5. Surface tension of aqueous humor.

    Science.gov (United States)

    Ross, Andrew; Blake, Robert C; Ayyala, Ramesh S

    2010-09-01

    To measure and compare the surface tension of aqueous humor in patients with and without glaucoma. The surface tension of aqueous humor was measured using a commercially available instrument and software that were validated by using a known fluid (deionized water and methanol). Analysis of aqueous and vitreous samples obtained from 20 rabbit eyes showed that the system could be used successfully for small amounts of ocular fluid. The effect of glaucoma drugs on the surface tension of aqueous humor was then studied in a rabbit model. Comparison of aqueous humor from 66 patients with glaucoma and 53 patients with cataracts but no glaucoma was carried out. The surface tension of rabbit aqueous humor was 65.9 ± 1.2; vitreous, 60.6 ± 2.6; and balanced salt solution, 70.7 ± 0.9. Timolol and latanoprost did not alter the surface tension of the aqueous humor in the rabbit model. The average surface tension of human aqueous humor was 63.33 ± 4.0 (glaucomatous eyes) and 66.19 ± 2.64 (nonglaucomatous eyes with cataracts) (P=0.0001). A technique of measuring the surface tension from small quantities of aqueous humor is validated. Surface tension of the aqueous humor in glaucoma patients was less than that of cataract patients.

  6. Endoscopic Ultrasound-Guided Direct Portal Pressure Measurement Using a Digital Pressure Wire with Real-Time Remote Display: A Survival Study.

    Science.gov (United States)

    Schulman, Allison R; Thompson, Christopher C; Ryou, Marvin

    2017-10-01

    Portal hypertension is necessary for the development of most clinical complications of cirrhosis. We recently reported a novel, endoscopic ultrasound (EUS)-guided technique for direct portal pressure measurements using a digital pressure wire. The aims of this study were to (1) evaluate safety in an animal survival model and (2) compare direct portal vein (PV) versus transhepatic access of a first-order venule. Yorkshire pigs, weighing 40-55 kg. Procedures were performed under general anesthesia. PV was identified using a linear array echoendoscope and accessed with a 22-G fine needle aspiration needle preloaded with a digital pressure wire. Access was confirmed by portal venography. Mean digital pressure measurements were recorded over 30 seconds, and again after accessing a first-order portal venule in a transhepatic manner. Procedure times and video logs were maintained throughout. Animals were survived for 2 weeks. Repeat portal pressure measurements were performed before euthanasia and necropsy. EUS-guided portal pressure measurements ranged from 3 to 11 mm Hg (mean 6.1) and were performed in a mean time of 214 seconds. There was no difference in measurement between the PV and first-order venule, or between baseline and 2-week follow-up. Five of 5 animals survived without incident. On necropsy, there was no evidence of thrombus or hemorrhage. This study represents the first survival study after EUS-guided direct portal pressure measurements using a digital pressure wire. This method appears safe, straightforward, and precise. Measurements of the PV and a first-order portal venule appear equivalent, and serial measurement seems feasible.

  7. Minimisation of the wire position uncertainties of the new CERN vacuum wire scanner

    CERN Document Server

    AUTHOR|(CDS)2069346; Barjau Condomines, A

    In the next years the luminosity of the LHC will be significantly increased. This will require a much higher accuracy of beam profile measurement than actually achievable by the current wire scanner. The new fast wire scanner is foreseen to measure small emittance beams throughout the LHC injector chain, which demands a wire travelling speed up to 20 ms-1 and position measurement accuracy of the order of a few microns. The vibrations of the mechanical parts of the system, and particularly the vibrations of the thin carbon wire, were identified as the major error sources of wire position uncertainty. Therefore the understanding of the wire vibrations is a high priority for the design and operation of the new device. This document presents the work performed to understand the main causes of the wire vibrations observed in one of the existing wire scanner and the new proposed design.

  8. Employing Hot Wire Anemometry to Directly Measure the Water Balance of a Commercial Proton Exchange Membrane Fuel Cell Stack

    DEFF Research Database (Denmark)

    Shakhshir, Saher Al; Berning, Torsten

    2016-01-01

    and increased degradation rates. Clearly, a fundamental understanding of all aspects of water management in PEMFC is imperative. This includes the fuel cell water balance, i.e. which fraction of the product water leaves the fuel cell via the anode channels versus the cathode channel. Our research group...... is currently developing a novel technique to obtain an ad-hoc and real time electrical signal of the fuel cell water balance by employing hot wire anemometry. In this work, the hot wire sensor is placed in the anode outlet of a commercial air-cooled fuel cell stack by Ballard Power Systems, and the voltage......Proton exchange membrane fuel cells (PEMFC’s) are currently being commercialized for various applications ranging from automotive (e.g. the Toyota Mirai) to stationary such as powering telecom backup units. In PEMFC’s, oxygen from air is internally combined with hydrogen to form water and produce...

  9. Development, implementation, and characterization of a standalone embedded viscosity measurement system based on the impedance spectroscopy of a vibrating wire sensor

    Science.gov (United States)

    Santos, José; Janeiro, Fernando M.; Ramos, Pedro M.

    2015-10-01

    This paper presents an embedded liquid viscosity measurement system based on a vibrating wire sensor. Although multiple viscometers based on different working principles are commercially available, there is still a market demand for a dedicated measurement system capable of performing accurate, fast measurements and requiring little or no operator training for simple systems and solution monitoring. The developed embedded system is based on a vibrating wire sensor that works by measuring the impedance response of the sensor, which depends on the viscosity and density of the liquid in which the sensor is immersed. The core of the embedded system is a digital signal processor (DSP) which controls the waveform generation and acquisitions for the measurement of the impedance frequency response. The DSP also processes the acquired waveforms and estimates the liquid viscosity. The user can interact with the measurement system through a keypad and an LCD or through a computer with a USB connection for data logging and processing. The presented system is tested on a set of viscosity standards and the estimated values are compared with the standard manufacturer specified viscosity values. A stability study of the measurement system is also performed.

  10. Breakage and Migration of Metal Wires in Operated Patella Fractures: Does it Correlate with Time?

    Directory of Open Access Journals (Sweden)

    Nin-Tai Sammy Mak

    2013-06-01

    Conclusions: The risk of patellar tension-band wire breakage was associated with increase time lapse from fracture fixation, but not the patients' age upon fracture fixation. The risk of wire breakage significantly increases after 12 months from the fracture fixation. Wire breakage can lead to further morbidities or complications. Routine removal of wire loops may be indicated. Future prospective longitudinal long-term studies may be required.

  11. Employing Hot Wire Anemometry to Directly Measure the Water Balance of a Proton Exchange Membrane Fuel Cell

    DEFF Research Database (Denmark)

    Shakhshir, Saher Al; Berning, Torsten

    Proton exchange membrane fuel cells (PEMFC’s) are currently being commercialized for various applications ranging from automotive to stationary such as powering telecom back-up units. In PEMFC’s, oxygen from air is internally combined with hydrogen to form water and produce electricity and waste...... in hot wire anemometry is the description of the Nusselt number as function of the Reynolds number and the Prandtl number, and in the current application it can be shown it is essential to employ a power-law equation instead of the commonly employed Churchill Bernstein equation. It will be shown...

  12. In vivo measurement of intracellular pH in human brain during different tensions of carbon dioxide in arterial blood. A 31P-NMR study

    DEFF Research Database (Denmark)

    Jensen, K E; Thomsen, C; Henriksen, O

    1988-01-01

    The effect of changes in carbon dioxide tension in arterial blood upon intracellular pH in brain tissue was studied in seven healthy volunteers, aged 22-45 years. The pH changes were monitored by use of 31P nuclear magnetic resonance spectroscopy, performed on a whole-body 1.5 Tesla Siemens imaging...... system. The measurements were carried out during hyperventilation and with the subject breathing atmospheric air containing 5 vol. % and 7 vol. % carbon dioxide. Intracellular pH increased significantly during 15 min of hyper-ventilation and decreased significantly during 18 min respiration of air...

  13. Sliding bubbles on a hot horizontal wire in a subcooled bath

    Science.gov (United States)

    Duchesne, Alexis; Dubois, Charles; Caps, Hervé

    2015-11-01

    When a wire is heated up to the boiling point in a liquid bath some bubbles will nucleate on the wire surface. Traditional nucleate boiling theory predicts that bubbles generate from active nucleate site, grow up and depart from the heating surface due to buoyancy and inertia. However, an alternative scenario is presented in the literature for a subcooled bath: bubbles slide along the horizontal wire before departing. New experiments were performed by using a constantan wire and different liquids, varying the injected power. Silicone oil, water and even liquid nitrogen were tested in order to vary wetting conditions, liquid viscosities and surface tensions. We explored the influence of the wire diameter and of the subcooled bath temperature. We observed, of course, sliding motion, but also a wide range of behaviors from bubbles clustering to film boiling. We noticed that bubbles could change moving sense, especially when encountering with another bubble. The bubble speed is carefully measured and can reach more than 100 mm/s for a millimetric bubble. We investigated the dependence of the speed on the different parameters and found that this speed is, for a given configuration, quite independent of the injected power. We understand these phenomena in terms of Marangoni effects. This project has been financially supported by ARC SuperCool contract of the University of Liège.

  14. Automatic wire twister.

    Science.gov (United States)

    Smith, J F; Rodeheaver, G T; Thacker, J G; Morgan, R F; Chang, D E; Fariss, B L; Edlich, R F

    1988-06-01

    This automatic wire twister used in surgery consists of a 6-inch needle holder attached to a twisting mechanism. The major advantage of this device is that it twists wires significantly more rapidly than the conventional manual techniques. Testing has found that the ultimate force required to disrupt the wires twisted by either the automatic wire twister or manual techniques did not differ significantly and was directly related to the number of twists. The automatic wire twister reduces the time needed for wire twisting without altering the security of the twisted wire.

  15. Stretched Wire Mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Bowden, Gordon; /SLAC

    2005-09-06

    Stretched wires are beginning to play an important role in the alignment of accelerators and synchrotron light sources. Stretched wires are proposed for the alignment of the 130 meter long LCLS undulator. Wire position technology has reached sub-micron resolution yet analyses of perturbations to wire straightness are hard to find. This paper considers possible deviations of stretched wire from the simple 2-dimensional catenary form.

  16. Prediction of material removal rate and surface roughness for wire electrical discharge machining of nickel using response surface methodology

    Directory of Open Access Journals (Sweden)

    Thangam Chinnadurai

    2016-12-01

    Full Text Available This study focuses on investigating the effects of process parameters, namely, Peak current (Ip, Pulse on time (Ton, Pulse off time (Toff, Water pressure (Wp, Wire feed rate (Wf, Wire tension (Wt, Servo voltage (Sv and Servo feed setting (Sfs, on the Material Removal Rate (MRR and Surface Roughness (SR for Wire electrical discharge machining (Wire-EDM of nickel using Taguchi method. Response Surface Methodology (RSM is adopted to evolve mathematical relationships between the wire cutting process parameters and the output variables of the weld joint to determine the welding input parameters that lead to the desired optimal wire cutting quality. Besides, using response surface plots, the interaction effects of process parameters on the responses are analyzed and discussed. The statistical software Mini-tab is used to establish the design and to obtain the regression equations. The developed mathematical models are tested by analysis-of-variance (ANOVA method to check their appropriateness and suitability. Finally, a comparison is made between measured and calculated results, which are in good agreement. This indicates that the developed models can predict the responses accurately and precisely within the limits of cutting parameter being used.

  17. The fracture toughness of small animal cortical bone measured using arc-shaped tension specimens: Effects of bisphosphonate and deproteinization treatments.

    Science.gov (United States)

    Hunckler, Michael D; Chu, Ethan D; Baumann, Andrew P; Curtis, Tyler E; Ravosa, Matthew J; Allen, Matthew R; Roeder, Ryan K

    2017-12-01

    Small animal models, and especially transgenic models, have become widespread in the study of bone mechanobiology and metabolic bone disease, but test methods for measuring fracture toughness on multiple replicates or at multiple locations within a single small animal bone are lacking. Therefore, the objective of this study was to develop a method to measure cortical bone fracture toughness in multiple specimens and locations along the diaphysis of small animal bones. Arc-shaped tension specimens were prepared from the mid-diaphysis of rabbit ulnae and loaded to failure to measure the radial fracture toughness in multiple replicates per bone. The test specimen dimensions, crack length, and maximum load met requirements for measuring the plane strain fracture toughness. Experimental groups included a control group, bisphosphonate treatment group, and an ex vivo deproteinization treatment following bisphosphonate treatment (5 rabbits/group and 15 specimens/group). The fracture toughness of ulnar cortical bone from rabbits treated with zoledronic acid for six months exhibited no difference compared with the control group. Partially deproteinized specimens exhibited significantly lower fracture toughness compared with both the control and bisphosphonate treatment groups. The deproteinization treatment increased tissue mineral density (TMD) and resulted in a negative linear correlation between the measured fracture toughness and TMD. Fracture toughness measurements were repeatable with a coefficient of variation of 12-16% within experimental groups. Retrospective power analysis of the control and deproteinization treatment groups indicated a minimum detectable difference of 0.1MPa·m1/2. Therefore, the overall results of this study suggest that arc-shaped tension specimens offer an advantageous new method for measuring the fracture toughness in small animal bones. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. A Vibrating Wire System For Quadrupole Fiducialization

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Zachary

    2010-12-13

    A vibrating wire system is being developed to fiducialize the quadrupoles between undulator segments in the LCLS. This note provides a detailed analysis of the system. The LCLS will have quadrupoles between the undulator segments to keep the electron beam focused. If the quadrupoles are not centered on the beam axis, the beam will receive transverse kicks, causing it to deviate from the undulator axis. Beam based alignment will be used to move the quadrupoles onto a straight line, but an initial, conventional alignment must place the quadrupole centers on a straight line to 100 {micro}m. In the fiducialization step of the initial alignment, the position of the center of the quadrupole is measured relative to tooling balls on the outside of the quadrupole. The alignment crews then use the tooling balls to place the magnet in the tunnel. The required error on the location of the quadrupole center relative to the tooling balls must be less than 25 {micro}m. In this note, we analyze a system under construction for the quadrupole fiducialization. The system uses the vibrating wire technique to position a wire onto the quadrupole magnetic axis. The wire position is then related to tooling balls using wire position detectors. The tooling balls on the wire position detectors are finally related to tooling balls on the quadrupole to perform the fiducialization. The total 25 {micro}m fiducialization error must be divided between these three steps. The wire must be positioned onto the quadrupole magnetic axis to within 10 {micro}m, the wire position must be measured relative to tooling balls on the wire position detectors to within 15 {micro}m, and tooling balls on the wire position detectors must be related to tooling balls on the quadrupole to within 10 {micro}m. The techniques used in these three steps will be discussed. The note begins by discussing various quadrupole fiducialization techniques used in the past and discusses why the vibrating wire technique is our method

  19. submitter Dynamical Models of a Wire Scanner

    CERN Document Server

    Barjau, Ana; Dehning, Bernd

    2016-01-01

    The accuracy of the beam profile measurements achievable by the current wire scanners at CERN is limited by the vibrations of their mechanical parts. In particular, the vibrations of the carbon wire represent the major source of wire position uncertainty which limits the beam profile measurement accuracy. In the coming years, due to the Large Hadron Collider (LHC) luminosity upgrade, a wire traveling speed up to 20 $m s^{−1}$ and a position measurement accuracy of the order of 1 μm will be required. A new wire scanner design based on the understanding of the wire vibration origin is therefore needed. We present the models developed to understand the main causes of the wire vibrations observed in an existing wire scanner. The development and tuning of those models are based on measurements and tests performed on that CERN proton synchrotron (PS) scanner. The final model for the (wire + fork) system has six degrees-of-freedom (DOF). The wire equations contain three different excitation terms: inertia...

  20. Wire grid and wire scanner design for the CERN Linac4

    CERN Document Server

    Roncarolo, F; Cheymol, B; Dutriat, C; Duraffourg, M; Focker, G J; Raich, U; Vuitton, C

    2010-01-01

    As part of the CERN LHC injector chain upgrade, LINAC4 [1] will accelerate H- ions from 45 KeV to 160 MeV. A number of wire grids and wire scanners will be used to characterize the beam transverse profile. This paper covers all monitor design aspects intended to cope with the required specifications. In particular, the overall measurement robustness, accuracy and sensitivity must be satisfied for different commissioning and operational scenarios. The physics mechanisms generating the wire signals and the wire resistance to beam induced thermal loads have been considered in order to determine the most appropriate monitor design in terms of wire material and dimensions.

  1. The Cloud Condensation Nuclei (CCN properties of 2-methyltetrols and C3-C6 polyols from osmolality and surface tension measurements

    Directory of Open Access Journals (Sweden)

    S. Ekström

    2009-02-01

    Full Text Available A significant fraction of the organic material in aerosols is made of highly soluble compounds such as sugars (mono- and polysaccharides and polyols such as the 2-methyltetrols, methylerythritol and methyltreitol. Because of their high solubility these compounds are considered as potentially efficient CCN material. For the 2-methyltetrols, this would have important implications for cloud formation at global scale because they are thought to be produced by the atmospheric oxidation of isoprene. To investigate this question, the complete Köhler curves for C3-C6 polyols and the 2-methyltetrols have been determined experimentally from osmolality and surface tension measurements. Contrary to what was expected, none of these compounds displayed a higher CCN efficiency than organic acids. Their Raoult terms show that this limited CCN efficiency is due to their absence of dissociation in water, this in spite of slight surface-tension effects for the 2-methyltetrols. Thus, compounds such as saccharides and polyols would not contribute more to cloud formation than other organic compounds studied so far. In particular, the presence of 2-methyltetrols in aerosols would not particularly enhance cloud formation in the atmosphere, in contrary to recently suggested.

  2. Determination of plasma pinch time and effective current radius of double planar wire array implosions from current measurements on a 1-MA linear transformer driver

    Science.gov (United States)

    Steiner, Adam M.; Yager-Elorriaga, David A.; Patel, Sonal G.; Jordan, Nicholas M.; Gilgenbach, Ronald M.; Safronova, Alla S.; Kantsyrev, Victor L.; Shlyaptseva, Veronica V.; Shrestha, Ishor; Schmidt-Petersen, Maximillian T.

    2016-10-01

    Implosions of planar wire arrays were performed on the Michigan Accelerator for Inductive Z-pinch Experiments, a linear transformer driver (LTD) at the University of Michigan. These experiments were characterized by lower than expected peak currents and significantly longer risetimes compared to studies performed on higher impedance machines. A circuit analysis showed that the load inductance has a significant impact on the current output due to the comparatively low impedance of the driver; the long risetimes were also attributed to high variability in LTD switch closing times. A circuit model accounting for these effects was employed to measure changes in load inductance as a function of time to determine plasma pinch timing and calculate a minimum effective current-carrying radius. These calculations showed good agreement with available shadowgraphy and x-ray diode measurements.

  3. Demonstration of Surface Tension.

    Science.gov (United States)

    Rosenthal, Andrew J.

    2001-01-01

    Surface tension is a fundamental obstacle in the spontaneous formation of bubbles, droplets, and crystal nuclei in liquids. Describes a simple overhead projector demonstration that illustrates the power of surface tension that can prevent so many industrial processes. (ASK)

  4. Wire bonding in microelectronics

    CERN Document Server

    Harman, George G

    2010-01-01

    Wire Bonding in Microelectronics, Third Edition, has been thoroughly revised to help you meet the challenges of today's small-scale and fine-pitch microelectronics. This authoritative guide covers every aspect of designing, manufacturing, and evaluating wire bonds engineered with cutting-edge techniques. In addition to gaining a full grasp of bonding technology, you'll learn how to create reliable bonds at exceedingly high yields, test wire bonds, solve common bonding problems, implement molecular cleaning methods, and much more. Coverage includes: Ultrasonic bonding systems and technologies, including high-frequency systems Bonding wire metallurgy and characteristics, including copper wire Wire bond testing Gold-aluminum intermetallic compounds and other interface reactions Gold and nickel-based bond pad plating materials and problems Cleaning to improve bondability and reliability Mechanical problems in wire bonding High-yield, fine-pitch, specialized-looping, soft-substrate, and extreme-temperature wire bo...

  5. Observation of ultrasonic guided wave propagation behaviours in pre-stressed multi-wire structures.

    Science.gov (United States)

    Liu, Xiucheng; Wu, Bin; Qin, Fei; He, Cunfu; Han, Qiang

    2017-01-01

    Ultrasonic guided wave (UGW) is a promising technique for nondestructive testing of pre-stressed multi-wire structures, such as steel strand and wire rope. The understanding of the propagation behaviours of UGW in these structures is a priority to applications. In the present study, first the properties of the UGW missing frequency band in the pre-stressed seven-wire steel strand is experimentally examined. The high correlation between the observed results and the previously published findings proves the feasibility of the magnetostrictive sensor (MsS) based testing method. The evolution of missing frequency band of UGW in slightly tensioned steel strand is discussed. Two calibration equations representing the relationship between the missing band parameters and the tensile force are given to derive a new tensile force measurement method, which is capable of measuring an incremental of stress of approximately 3MPa. Second, the effects of tensile force on the UGW propagation behaviours in three types of complicated steel wire ropes are alternatively investigated based on the short time Fourier transform (STFT) results of the received direct transmission wave (DTW) signals. The observed inherent missing frequency band of the longitudinal mode UGW in the pre-stressed steel wire rope and its shifting to a higher frequency range as the increases of the applied tensile force are reported for the first time. The influence of applied tensile force on the amplitude of the DTW signal and the unique UGW energy jump behaviour observed in a wire rope of 16.0mm, 6×Fi(29)+IWRC are also investigated, despite the fact that they cannot yet be explained. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Effect of Gravity on Surface Tension

    Science.gov (United States)

    Weislogel, M. M.; Azzam, M. O. J.; Mann, J. A.

    1998-01-01

    Spectroscopic measurements of liquid-vapor interfaces are made in +/- 1-g environments to note the effect of gravity on surface tension. A slight increase is detected at -1-g0, but is arguably within the uncertainty of the measurement technique. An increased dependence of surface tension on the orientation and magnitude of the gravitational vector is anticipated as the critical point is approached.

  7. Laser Wire Stripper

    Science.gov (United States)

    1983-01-01

    NASA-developed space shuttle technology is used in a laser wire stripper designed by Raytheon Company. Laser beams cut through insulation on a wire without damaging conductive metal, because laser radiation that melts plastic insulation is reflected by the metal. The laser process is fast, clean, precise and repeatable. It eliminates quality control problems and the expense of rejected wiring.

  8. "Cut wires grating – single longitudinal wire" planar metastructure to achieve microwave magnetic resonance in a single wire

    Directory of Open Access Journals (Sweden)

    G. Kraftmakher

    2012-09-01

    Full Text Available Here we present metastructures containing cut-wire grating and a single longitudinal cut-wire orthogonal to grating’s wires. Experimental investigations at microwaves show these structures can provide strong magnetic resonant response of a single nonmagnetic cut-wire in dependence on configuration and sizes in the case when metastructures are oriented along the direction of wave propagation and cut-wires of grating are parallel to the electric field of a plane electromagnetic wave. It is suggested a concept of magnetic response based on antiparallel resonant currents excited by magnetic field of surface polaritons in many spatial LC-circuits created from cut-wire pairs of a grating and section of longitudinal cut-wire. Three separately observed resonant effects connected with grating, LC-circuits and with longitudinal cut-wire have been identified applying measurements in waveguides, cutoff waveguides and free space. To tune and mark resonance split cut-wires are loaded with varactor diodes.

  9. Modeling and experimentation of a positioning system of SMA wires

    Science.gov (United States)

    Lei, KinFong; Yam, Yeung

    2000-06-01

    This work reports two modeling and control attempts performed on a positioning system comprising of linking SMA wires and an overlooking video system for on-line measurements. The first attempt takes the model by Ikuta and identifies experimentally the parameters of the SMA wire. The identified single wire model is then extended to a system of two SMA wires joining together at their tips, based upon which open loop position control of the linkage is then conducted. The approach, however, becomes too complicated when more SMA wires are involved. The second attempt utilizes a neuro-fuzzy based approach for positioning control of a linkage point joining together four SMA wires. The second approach involves four ANFIS neuro-networks with hybrid learning algorithm trained to model the currents to the SMA wires as functions of present and target positions of the linkage point. Experimentation for both the two-wires and four-wires system yield quite satisfactory performance.

  10. Measurements of Thermal Conductivity and Thermal Diffusivity of Hen Egg-White Lysozyme Crystals and Its Solution Using the Transient Short Hot Wire Method

    Science.gov (United States)

    Fujiwara, Seiji; Maki, Syou; Maekawa, Ryunosuke; Tanaka, Seiichi; Hagiwara, Masayuki

    2017-08-01

    Protein crystals are an essentially important biological sample to advance the analysis of X-ray structure, but their thermophysical properties, especially thermal conductivity and thermal diffusivity, have not been studied sufficiently. This current situation can be attributed to various kinds of technical problems; e.g., the fragility of protein crystals and the difficulty of nucleation control. Ideally speaking, protein crystallization should be carried out under a " containerless condition" to eliminate any mechanical distortion of the crystals from the walls. To realize the condition, we have developed an original crystallization method by means of the magneto-Archimedes effect. In this paper, a transient short hot wire method was combined with the technique of magneto-Archimedes effect to realize simultaneous measurement of thermal conductivity and thermal diffusivity of hen egg-white lysozyme (HEWL) crystals. As the results, thermal conductivity and thermal diffusivity of HEWL crystals were found to be 0.410-0.438 \\hbox {W}\\cdot \\hbox {m}^{-1}\\cdot \\hbox {K}^{-1} and 3.77-5.18× 10^{-8} \\hbox {m}2\\cdot \\hbox {s}^{-1}, respectively. We clarified by the crystallizing process of HEWL that the crystals were magnetically levitated at the air-liquid interface and the short hot wire was completely buried into them as the crystals grew. We also measured the HEWL solution by the same methods. The thermal conductivity of the solution had almost the same value as that of water and had little dependency on the concentration of HEWL, but the thermal diffusivity was unclear.

  11. Construction and assembly of the wire planes for the MicroBooNE Time Projection Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Acciarri, R.; Adams, C.; Asaadi, J.; Danaher, J.; Fleming, B. T.; Gardner, R.; Gollapinni, S.; Grosso, R.; Guenette, R.; Littlejohn, B. R.; Lockwitz, S.; Raaf, J. L.; Soderberg, M.; John, J. St.; Strauss, T.; Szelc, A. M.; Yu, B.

    2017-03-01

    In this paper we describe how the readout planes for the MicroBooNE Time Projection Chamber were constructed, assembled and installed. We present the individual wire preparation using semi-automatic winding machines and the assembly of wire carrier boards. The details of the wire installation on the detector frame and the tensioning of the wires are given. A strict quality assurance plan ensured the integrity of the readout planes. The different tests performed at all stages of construction and installation provided crucial information to achieve the successful realization of the MicroBooNE wire planes.

  12. Wire in the Cable-Driven System of Surgical Robot

    Science.gov (United States)

    Wang, X. F.; Lv, N.; Mu, H. Z.; Xue, L. J.

    2017-07-01

    During the evolution of the surgical robot, cable plays an important role. It translates motion and force precisely from surgeon’s hand to the tool’s tips. In the paper, the vertical wires, the composition of cable, are mathematically modeled from a geometric point of view. The cable structure and tension are analyzed according to the characteristics of wire screw twist. The structural equations of the wires in different positions are derived for both non-bent cable and bent cable, respectively. The bending moment formula of bent cable is also obtained. This will help researchers find suitable cable and design more matched pulley.

  13. The Eulerian buckling test for orthodontic wires.

    Science.gov (United States)

    De Santis, R; Dolci, F; Laino, A; Martina, R; Ambrosio, L; Nicolais, L

    2008-04-01

    Orthodontic treatment is mainly dependent on the loads developed by metal wires. The load developed by a buckled orthodontic wire is of great concern for molar distalization and cannot be simply derived from mechanical properties measured through classical tests (i.e. tensile, torsion, and bending). A novel testing method, based on the Eulerian approach of a simple supported beam, has been developed in order to measure the load due to buckling of orthodontic wires. Elastic titanium molybdenum alloy (TMA; SDS Ormco) and superelastic Nitinol (3M Unitek) and copper nickel-titanium (NiTi; SDS Ormco) wires, each having a rectangular cross section of 0.016 x 0.022 square inches (0.41 x 0.56 mm(2)), were used. The wires were activated and deactivated by loading and unloading. In order to analyse thermo-mechanical properties in buckling, mechanical tests were assisted by calorimetric measurements through differential scanning calorimetry (DSC). Statistical analysis to determine differences between the samples was undertaken using two-way analysis of variance (ANOVA) and Tukey's post hoc test, and one-way ANOVA to assess differences between the tested wires under similar conditions and different materials. The results suggest that the load due to buckling depends on material composition, wire length, the amount of activation, temperature, and deformation rate. The results can be considered as the lower bound for the loads experienced by teeth as far as a buckled wire is concerned. At a temperature higher than the austenite finish transition temperature, superelastic wires were strongly dependent on temperature and deformation rate. The effect due to an increase of deformation rate was similar to that of a decrease of temperature. Load variations due to temperature of a superelastic wire with a length of 20 mm were estimated to be approximately 4 g/degrees C. The high performance of an applied superelastic wire may be related to the high dynamics of the load in relation to

  14. Health monitoring of prestressing tendons in post-tensioned concrete structures

    Science.gov (United States)

    Salamone, Salvatore; Bartoli, Ivan; Nucera, Claudio; Phillips, Robert; Lanza di Scalea, Francesco

    2011-04-01

    Currently 90% of bridges built in California are post-tensioned box-girder. In such structures the steel tendons are the main load-carrying components. The loss of prestress, as well as the presence of defects or the tendon breakage, can be catastrophic for the entire structure. Unfortunately, today there is no well-established method for the monitoring of prestressing (PS) tendons that can provide simultaneous information related to the presence of defects and the level of prestress in a continuous, real time manner. If such a monitoring system were available, considerable savings would be achieved in bridge maintenance since repairs would be implemented in a timely manner without traffic disruptions. This paper presents a health monitoring system for PS tendons in post-tensioned structures of interest to Caltrans. Such a system uses ultrasonic guided waves and embedded sensors to provide simultaneously and in real time, (a) measurements of the level of applied prestress, and (b) defect detection at early grow stages. The proposed PS measurement technique exploits the sensitivity of ultrasonic waves to the inter-wire contact developing in a multi-wire strand as a function of prestress level. In particular the nonlinear ultrasonic behavior of the tendon under changing levels of prestress is monitored by tracking higher-order harmonics at (nω) arising under a fundamental guided-wave excitation at (ω). Moreover this paper also present real-time damage detection and location in post-tensioned bridge joints using Acoustic Emission techniques. Experimental tests on large-scale single-tendon PT joint specimens, subjected to multiple load cycles, will be presented to validate the monitoring of PS loads (through nonlinear ultrasonic probing) and the monitoring of damage progression and location (through acoustic emission techniques). Issues and potential for the use of such techniques to monitor post-tensioned bridges in the field will be discussed.

  15. PS wire chamber

    CERN Multimedia

    1970-01-01

    A wire chamber used at CERN's Proton Synchrotron accelerator in the 1970s. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  16. Effect of wire shape on wire array discharge

    Energy Technology Data Exchange (ETDEWEB)

    Shimomura, N.; Tanaka, Y.; Yushita, Y.; Nagata, M. [University of Tokushima, Department of Electrical and Electronic Engineering, Tokushima (Japan); Teramoto, Y.; Katsuki, S.; Akiyama, H. [Kumamoto University, Department of Electrical and Computer Engineering, Kumamoto (Japan)

    2001-09-01

    Although considerable investigations have been reported on z-pinches to achieve nuclear fusion, little attention has been given from the point of view of how a wire array consisting of many parallel wires explodes. Instability existing in the wire array discharge has been shown. In this paper, the effect of wire shape in the wire array on unstable behavior of the wire array discharge is represented by numerical analysis. The claws on the wire formed in installation of wire may cause uniform current distribution on wire array. The effect of error of wire diameter in production is computed by Monte Carlo Method. (author)

  17. Influence of Wire Electrical Discharge Machining (WEDM) process parameters on surface roughness

    Science.gov (United States)

    Yeakub Ali, Mohammad; Banu, Asfana; Abu Bakar, Mazilah

    2018-01-01

    In obtaining the best quality of engineering components, the quality of machined parts surface plays an important role. It improves the fatigue strength, wear resistance, and corrosion of workpiece. This paper investigates the effects of wire electrical discharge machining (WEDM) process parameters on surface roughness of stainless steel using distilled water as dielectric fluid and brass wire as tool electrode. The parameters selected are voltage open, wire speed, wire tension, voltage gap, and off time. Empirical model was developed for the estimation of surface roughness. The analysis revealed that off time has a major influence on surface roughness. The optimum machining parameters for minimum surface roughness were found to be at a 10 V open voltage, 2.84 μs off time, 12 m/min wire speed, 6.3 N wire tension, and 54.91 V voltage gap.

  18. Development of a high precision tabletop versatile CNC wire-EDM for making intricate micro parts

    Science.gov (United States)

    Liao, Yunn-Shiuan; Chen, Shun-Tong; Lin, Chang-Sheng

    2005-02-01

    The micro-electrical discharge machining (micro-EDM) process has been proved to be appropriate for making 3D micro parts that are difficult and even impossible to manufacture by other processes. In this paper a high precision tabletop CNC wire electrical discharge machine (wire EDM) designed specifically for machining complex shape micro parts or structures is developed. In the machine developed, a novel micro-wire-cutting mechanism is designed, an approach to control wire tension by magnetic force is proposed and a servo feed control strategy, in accordance with the measured gap voltage, is designed and implemented. To verify the functions and capabilities of the machine developed, several thick micro outer and internal spur gears and rack are machined. It shows that the taper angle along the wall or cavity of a part that appears when other micro-EDM processes are applied can be avoided. A very good dimensional accuracy of 1 µm and a surface finish of Rmax equal to 0.64 µm are achieved. The satisfactory cutting of a miniature 3D pagoda with a micro-hooked structure also reveals that the machine developed is versatile, and can be used as a new tool for making intricate micro parts.

  19. 75 FR 37382 - Notice of Antidumping Duty Order: Prestressed Concrete Steel Wire Strand from the People's...

    Science.gov (United States)

    2010-06-29

    ... steel, which is suitable for use in prestressed concrete (both pretensioned and post-tensioned... International Trade Administration Notice of Antidumping Duty Order: Prestressed Concrete Steel Wire Strand from... duty order on prestressed concrete steel wire strand (``PC strand'') from the People's Republic of...

  20. Easy to use and reliable technique for online dissolved oxygen tension measurement in shake flasks using infrared fluorescent oxygen-sensitive nanoparticles.

    Science.gov (United States)

    Flitsch, David; Ladner, Tobias; Lukacs, Mihaly; Büchs, Jochen

    2016-02-24

    Despite the progressive miniaturization of bioreactors for screening purposes, shake flasks are still widespread in biotechnological laboratories and industry as cultivation vessels. Shake flasks are often applied as the first or second step in applications such as strain screening or media optimization. Thus, there are ongoing efforts to develop online measurement techniques for shake flasks, to gain as much information as possible about the cultured microbial system. Since dissolved oxygen tension (DOT) is a key experimental parameter, its accurate determination during the course of experiment is critical. Some of the available DOT measurement techniques can lead to erroneous measurements or are very difficult to handle. A reliable and easy to use DOT measurement system, based on suspended oxygen-sensitive nanoparticles, is presented in this work. In a cultivation of Kluyveromyces lactis, a new DOT measurement technique via suspended oxygen-sensitive nanoparticles was compared with the conventional DOT measurement via fixed sensor spots. These experiments revealed the main disadvantage of applying sensor spots. With further cultivations of Escherichia coli and Hansenula polymorpha, the new measurement technique was successfully validated. In combination with a RAMOS device, kLa values were determined during the presented cultivations. The determined kLa values are in good agreement with a correlation recently found in the literature. The presented DOT measurement technique via suspended oxygen-sensitive nanoparticles in shake flasks turned out to be easy to use, robust and reliable under all applied combinations of shaking frequencies and filling volumes. Its applicability as an online monitoring system for cultivations was shown by means of four examples. Additionally, in combination with a RAMOS device, the possibility of experimental kLa determination was successfully demonstrated.

  1. Emotion versus Tension in Haydn's Symphony No. 104 as Measured by the Two-Dimensional Continuous Response Digital Interface.

    Science.gov (United States)

    Madsen, Clifford K.

    1998-01-01

    Compares musicians' responses while listening to the first movement of Haydn's Symphony No. 104 using a two-dimensional continuous response digital interface that measured arousal (relaxing-exciting) and affect (ugly-beautiful). Indicates that there is an inverse relationship between the two dimensions. Makes comparisons to research that has…

  2. Basic Wiring. Third Edition. Teacher Edition [and] Student Edition.

    Science.gov (United States)

    Kaltwasser, Stan; Flowers, Gary; Blasingame, Don; Batson, Larry; Ipock, Dan; Carroll, Charles; Friesen, Wade; Fleming, Glenn

    This publication contains both a teacher edition and a student edition of materials for a foundation course in an electrical wiring program. The course introduces basic concepts and skills that are prerequisites to residential wiring and commercial and industrial wiring courses. The contents of the materials are tied to measurable and observable…

  3. Precise, contactless measurements of the surface tension of picolitre aerosol droplets† †Electronic supplementary information (ESI) available: Parametrizations used to infer concentration, density, viscosity, and surface tension from refractive index for sodium chloride and glutaric acid; description of the semi-analytical T-matrix calculations; Fig. S1 and S2. See DOI: 10.1039/c5sc03184b Click here for additional data file.

    Science.gov (United States)

    Bzdek, Bryan R.; Power, Rory M.; Simpson, Stephen H.; Royall, C. Patrick

    2016-01-01

    The surface composition and surface tension of aqueous droplets can influence key aerosol characteristics and processes including the critical supersaturation required for activation to form cloud droplets in the atmosphere. Despite its fundamental importance, surface tension measurements on droplets represent a considerable challenge owing to their small volumes. In this work, we utilize holographic optical tweezers to study the damped surface oscillations of a suspended droplet (surface tension and viscosity of droplets containing only 1–4 pL of material. An advantage of performing the measurement in aerosol is that supersaturated solute states (common in atmospheric aerosol) may be accessed. For pairs of droplets starting at their equilibrium surface composition, surface tensions and viscosities are consistent with bulk equilibrium values, indicating that droplet surfaces respond to changes in surface area on microsecond timescales and suggesting that equilibrium values can be assumed for growing atmospheric droplets. Furthermore, droplet surfaces are shown to be rapidly modified by trace species thereby altering their surface tension. This equilibration of droplet surface tension to the local environmental conditions is illustrated for unknown contaminants in laboratory air and also for droplets exposed to gas passing through a water–ethanol solution. This approach enables precise measurements of surface tension and viscosity over long time periods, properties that currently are poorly constrained. PMID:28758004

  4. Diamagnetism in wire medium metamaterials: Theory and experiment

    Science.gov (United States)

    Yagupov, I.; Filonov, D.; Ageyskiy, A.; Kosulnikov, S.; Hasan, M.; Iorsh, I. V.; Belov, P. A.

    2015-07-01

    A strong diamagnetic response of a wire medium with a finite wire radius is reported. Contrary to the previous works where it was assumed that the wire medium exhibits only an electric response, we show that the nonzero magnetic susceptibility has to be taken into account for a proper effective medium description of the wire medium. Analytical and numerical results are supported by experimental measurements.

  5. The biomechanical evaluation of polyester as a tension band for the internal fixation of patellar fractures.

    LENUS (Irish Health Repository)

    McGreal, G

    2012-02-03

    We use a braided polyester suture in place of cerclage wire in tension band fixations. The objective of this study was to test the biomechanical properties of this technique. Sixteen cadaveric patellae were fractured and repaired by modified tension band fixation. Eight were fixed using eighteen gauge stainless steel wire as a tension band and eight using braided polyester. All specimens were subjected to tensile testing. Polyester was 75.0% as strong as wire. For dynamic testing, the patellae of seven cadaveric knees were fractured and then fixed with polyester tension bands. These were mounted in a device capable of extending the knees from 90 degrees to neutral against an applied force. None of the fixations failed. Three of the specimens fixed using 18 gauge stainless steel wire were compared with three fixed using polyester over 2000 cycles of knee flexion and extension. Polyester performed as well as wire. We conclude that polyester is an acceptable alternative to wire in tension band fixation.

  6. Permanent tensions in organization.

    Science.gov (United States)

    Jansson, Noora

    2015-01-01

    The purpose of this paper is to investigate the relationship between permanent tensions and organizational change. This study used paradox theory and a case study. The case organization is a public university hospital in Finland involving several stakeholders. The analysis suggests that the relationship between permanent tensions and organizational change is a paradox that is part of organizational reality. As an organization learns to live with its permanent tensions, the renewal paradox settles into equilibrium. When tensions are provoked, the paradox is disturbed until it finds a new balance. This flexible nature of the paradox is the force that keeps the different stakeholders simultaneously empowered to maintain their unique missions and cohesive in order to benefit from the larger synergy. This research suggests that identification and evaluation of each permanent tension within an organization is important when executing organizational change. The fact that certain tensions are permanent and cannot be solved may have an influence on how planned change initiatives are executed. The results show that permanent tensions may be harnessed for the benefit of an organizational change. This research demonstrates originality by offering an alternative view of tensions, a view which emphasizes not only their permanent and plural nature but their importance for enabling the organization to change at its own, non-disruptive pace. The research also proposes a new concept, the "renewal paradox", to enhance understanding of the relationship between permanent tensions and organizational change.

  7. Wire + Arc Additive Manufacturing

    OpenAIRE

    Williams, Stewart W.; Martina, Filomeno; Addison, Adrian C.; Ding, Jialuo; Pardal, Goncalo; Colegrove, Paul A.

    2016-01-01

    Depositing large components (>10 kg) in titanium, aluminium, steel and other metals is possible using Wire + Arc Additive Manufacturing. This technology adopts arc welding tools and wire as feedstock for additive manufacturing purposes. High deposition rates, low material and equipment costs, and good structural integrity make Wire+Arc Additive Manufacturing a suitable candidate for replacing the current method of manufacturing from solid billets or large forgings, especially with regards to ...

  8. Radiation of relativistic electrons in a periodic wire structure

    Energy Technology Data Exchange (ETDEWEB)

    Soboleva, V.V., E-mail: sobolevaveronica@mail.ru; Naumenko, G.A.; Bleko, V.V.

    2015-07-15

    We present in this work the experimental investigation of the interaction of relativistic electron field with periodic wire structures. We used two types of the targets in experiments: flat wire target and sandwich wire target that represent the right triangular prism. The measurements were done in millimeter wavelength region (10–40 mm) on the relativistic electron beam with energy of 6.2 MeV in far-field zone. We showed that bunched electron beam passing near wire metamaterial prism generates coherent Cherenkov radiation. The experiments with flat wire target were carried out in two geometries. In the first geometry the electron beam passed close to the flat wire target surface. In the second case the electron beam passed through the flat wire structure with generation of a coherent backward transition radiation (CBTR). The comparison of the Cherenkov radiation intensity and BTR intensity from the flat wire target and from the flat conductive target (conventional BTR) was made.

  9. Tension permeameter for deep borehole characterization

    Energy Technology Data Exchange (ETDEWEB)

    Sisson, J.B.; Honeycutt, T.K. [EG and G Idaho, Inc., Idaho Falls, ID (United States)

    1994-12-31

    The permeability of geologic materials is an important variable for estimating the rate of transport of contaminants from waste sites. To date, permeability has been estimated in the laboratory from measurements made on small cores, under hydrologic conditions far removed from those of the field. Available field instruments cannot estimate permeabilities at depth under ambient conditions. The authors have constructed a borehole tension permeameter that is capable of operating at near field conditions and at depths of more than 30 m. The tension permeameter consists of a syringe pump, lightweight packer, semipermeable membrane, and pressure transducer, all controlled by a programmable logic controller. Water is metered at a fixed rate through the membrane while monitoring tension. The permeability is estimated from the steady pumping rate for the membrane geometry used at the measured water tension. The permeameter was used to estimate the permeability of Pancheri sandy loam at tensions of 0 to 150 cm.

  10. Charpak hemispherical wire chamber

    CERN Multimedia

    1970-01-01

    pieces. Mesures are of the largest one. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  11. Photovoltaic Wire Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project will investigate a new architecture for photovoltaic devices based on nanotechnology: photovoltaic wire. The...

  12. 1998 wire development workshop proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    This report consists of vugraphs of the presentations at the conference. The conference was divided into the following sessions: (1) First Generation Wire Development: Status and Issues; (2) First Generation Wire in Pre-Commercial Prototypes; (3) Second Generation Wire Development: Private Sector Progress and Issues; (4) Second Generation Wire Development: Federal Laboratories; and (5) Fundamental Research Issues for HTS Wire Development.

  13. Improvement of the free-surface tension model in shallow water basin by using in-situ bottom-friction measurements

    Science.gov (United States)

    Alekseenko, Elena; Kuznetsov, Konstantin; Roux, Bernard

    2016-04-01

    Wind stress on the free surface is the main driving force behind the circulation of the upper part of the ocean, which in hydrodynamic models are usually defined in terms of the coefficient of surface tension (Zhang et al., 2009, Davies et al., 2003). Moreover, wave motion impacts local currents and changes sea level, impacts the transport and the stratification of the entire water column. Influence of surface waves at the bottom currents is particularly pronounced in the shallow coastal systems. However, existing methods of parameterization of the surface tension have significant limits, especially in strong wind waves (Young et al., 2001, Jones et al., 2004) due to the difficulties of measuring the characteristics of surface waves in stormy conditions. Thus, the formula for calculating the coefficient of surface tension in our day is the actual problem in modeling fluid dynamics, particularly in the context of strong surface waves. In the hydrodynamic models usually a coefficient of surface tension is calculated once at the beginning of computation as a constant that depends on the averaged wind waves characteristic. Usually cases of strongly nonlinear wind waves are not taken into account, what significantly reduces the accuracy of the calculation of the flow structures and further calculation of the other processes in water basins, such as the spread of suspended matter and pollutants. Thus, wave motion influencing the pressure on the free surface and at the bottom must be considered in hydrodynamic models particularly in shallow coastal systems. A method of reconstruction of a free-surface drag coefficient based on the measured in-situ bottom pressure fluctuations is developed and applied in a three-dimensional hydrodynamic model MARS3D, developed by the French laboratory of IFREMER (IFREMER - French Research Institute for Marine Dynamics). MARS3D solves the Navier-Stokes equations for incompressible fluid in the Boussinesq approximation and with the

  14. Tensions in Distributed Leadership

    Science.gov (United States)

    Ho, Jeanne; Ng, David

    2017-01-01

    Purpose: This article proposes the utility of using activity theory as an analytical lens to examine the theoretical construct of distributed leadership, specifically to illuminate tensions encountered by leaders and how they resolved these tensions. Research Method: The study adopted the naturalistic inquiry approach of a case study of an…

  15. Testing of a hot- and cold-wire probe to measure simultaneously the speed and temperature in supercritical CO{sub 2} flow

    Energy Technology Data Exchange (ETDEWEB)

    Vukoslavcevic, Petar V.; Radulovic, Ivana M. [University of Montenegro, Podgorica (Czechoslovakia); Wallace, James M. [University of Maryland, MD (United States)

    2005-10-01

    The use of hot-wire anemometry in carbon dioxide flow under supercritical conditions has been analyzed and implemented for the first time. A two-sensor probe to simultaneously measure streamwise velocity and temperature in this flow has been designed and constructed. A calibration and test flow loop that can provide supercritical state conditions above the critical point has been also designed, fabricated and tested. The temperature and velocity flow fields of the flow loop can be varied at constant pressure. It has been found that, above the pseudo-critical temperature, the velocity sensor response fits King's cooling law with a high correlation coefficient. The dependence of the King's law parameters on temperature can be accurately presented with second or higher order polynomial or exponential fits, depending on the extent of the temperature range. Below the pseudocritical temperature the data is scattered, and the variation with temperature of the King's law parameters, determined from calibration, is irregular. The influence on this data scatter of the strong variation of the fluid properties near the critical point is analyzed, and a possibility to reduce it is proposed. The temperature sensor response both above and below the pseudocritical temperature is similar to the response under normal conditions. It is linear with a very high correlation coefficient between the calibration data and the fitted curve. It is also shown that the temperature response is not affected by variation of the flow's speed. (orig.)

  16. Development of a windowless multi-wire proportional chamber (MWPC) counting system for measuring extended-area beta source.

    Science.gov (United States)

    Hwang, S H; Lee, J M; Lee, K B; Park, T S

    2017-08-01

    A windowless MWPC counting system has been developed to measure surface emission rate of extended-area sources. A new anode and guard plane design gives better electric-field uniformity in the (250×200)mm(2) sensitive volume relative to a previous-generation MWPC at KRISS, which has been used as a national standard with uncertainty MWPC system were studied, and the uncertainty was estimated with an extended-area (36)Cl source. The relative combined standard uncertainty was evaluated to be 0.23%, a 50% improvement over the previous-generation MWPC counting system. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Titanium mesh as a low-profile alternative for tension-band augmentation in patella fracture fixation: A biomechanical study.

    Science.gov (United States)

    Dickens, Aaron J; Salas, Christina; Rise, LeRoy; Murray-Krezan, Cristina; Taha, Mahmoud Reda; DeCoster, Thomas A; Gehlert, Rick J

    2015-01-01

    We performed a simple biomechanical study to compare the fixation strength of titanium mesh with traditional tension-band augmentation, which is a standard treatment for transverse patella fractures. We hypothesised that titanium mesh augmentation is not inferior in fixation strength to the standard treatment. Twenty-four synthetic patellae were tested. Twelve were fixed with stainless steel wire and parallel cannulated screws. Twelve were fixed with parallel cannulated screws, augmented with anterior titanium mesh and four screws. A custom test fixture was developed to simulate a knee flexed to 90°. A uniaxial force was applied to the simulated extensor mechanism at this angle. A non-inferiority study design was used to evaluate ultimate force required for failure of each construct as a measure of fixation strength. Stiffness of the bone/implant construct, fracture gap immediately prior to failure, and modes of failure are also reported. The mean difference in force at failure was -23.0 N (95% CI: -123.6 to 77.6N) between mesh and wire constructs, well within the pre-defined non-inferiority margin of -260 N. Mean stiffness of the mesh and wire constructs were 19.42 N/mm (95% CI: 18.57-20.27 N/mm) and 19.49 N/mm (95% CI: 18.64-20.35 N/mm), respectively. Mean gap distance for the mesh constructs immediately prior to failure was 2.11 mm (95% CI: 1.35-2.88 mm) and 3.87 mm (95% CI: 2.60-5.13 mm) for wire constructs. Titanium mesh augmentation is not inferior to tension-band wire augmentation when comparing ultimate force required for failure in this simplified biomechanical model. Results also indicate that stiffness of the two constructs is similar but that the mesh maintains a smaller fracture gap prior to failure. The results of this study indicate that the use of titanium mesh plating augmentation as a low-profile alternative to tension-band wiring for fixation of transverse patella fractures warrants further investigation. Copyright © 2015 Elsevier Ltd. All

  18. Transport in quantum wires

    Indian Academy of Sciences (India)

    This motivated us to study the LL model of a quantum wire, with Fermi liquid leads and the unusual feature of ... of quantized conductance even in clean quantum wires and a novel odd–even effect in the presence of a .... But in one dimension, it is well-known that the FL theory breaks down, and the ground state is a ...

  19. Commercial and Industrial Wiring.

    Science.gov (United States)

    Kaltwasser, Stan; Flowers, Gary

    This module is the third in a series of three wiring publications, includes additional technical knowledge and applications required for job entry in the commercial and industrial wiring trade. The module contains 15 instructional units that cover the following topics: blueprint reading and load calculations; tools and equipment; service;…

  20. Initial tension loss in cerclage cables.

    Science.gov (United States)

    Ménard, Jérémie; Émard, Maxime; Canet, Fanny; Brailovski, Vladimir; Petit, Yvan; Laflamme, George Y

    2013-10-01

    Cerclage cables, frequently used in the management of fractures and osteotomies, are associated with a high failure rate and significant loosening during surgery. This study compared the capacity to maintain tension of different types of orthopaedic cable systems. Multifilament Cobalt-Chrome (CoCr) cables with four different crimp/clamp devices (DePuy, Stryker, Zimmer and Smith&Nephew) and one non-metallic Nylon (Ny) cable from Kinamed were instrumented with a load cell to measure tension during insertion. Significant tension loss was observed with crimping for all cables (Ptensioner led to an additional unexpected tension loss (CoCr-DePuy: 18%, CoCr-Stryker: 29%, CoCr-Smith&Nephew: 33%, Ny: 46%, and CoCr-Zimmer: 52%). The simple CoCr (DePuy) cable system outperformed the more sophisticated locking devices due to its significantly better ability to prevent tension loss. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Surface tension profiles in vertical soap films

    Science.gov (United States)

    Adami, N.; Caps, H.

    2015-01-01

    Surface tension profiles in vertical soap films are experimentally investigated. Measurements are performed by introducing deformable elastic objets in the films. The shape adopted by those objects once set in the film is related to the surface tension value at a given vertical position by numerically solving the adapted elasticity equations. We show that the observed dependency of the surface tension versus the vertical position is predicted by simple modeling that takes into account the mechanical equilibrium of the films coupled to previous thickness measurements.

  2. Repair of olecranon fractures using fiberWire without metallic implants: report of two cases

    Directory of Open Access Journals (Sweden)

    Okawa Atsushi

    2010-10-01

    Full Text Available Abstract Olecranon fractures are a common injury in fractures. The tension band technique for olecranon fractures yields good clinical outcomes; however, it is associated with significant complications. In many patients, implants irritate overlying soft tissues and cause pain. This is mostly due to protrusion of the proximal ends of the K-wires or by the twisted knots of the metal wire tension band. Below we described 2 cases of olecranon fractures treated with a unique technique using FiberWire without any metallic implants. Technically, the fragment was reduced, and two K-wires were inserted from the dorsal cortex of the distal segment to the tip of the olecranon. K-wire was exchanged for a suture retriever, and 2 strands of FiberWire were retrieved twice. Each of the two FiberWires was manually tensioned and knotted on the posterior surface of the olecranon. Bony unions could be achieved, and patients had no complaint of pain and skin irritation. There was only a small loss of flexion and extension in comparison with that of the contralateral side, and the patient did not feel inconvenienced in his daily life. Using the method described, difficulty due to K-wire or other metallic implants was avoided.

  3. Flow dynamics of cerebrospinal fluid between the intracranial cavity and the subarachnoid space of the optic nerve measured with a diffusion magnetic resonance imaging sequence in patients with normal tension glaucoma.

    Science.gov (United States)

    Boye, Dirk; Montali, Margherita; Miller, Neil R; Pircher, Achmed; Gruber, Philipp; Killer, Hanspeter E; Remonda, Luca; Berberat, Jatta

    2017-11-25

    This study offers a new approach for the quantification of CSF dynamics. Non-invasive method to quantify the CSF dynamics in the subarachnoid space of the optic nerve is highly desirable. The aim of the study was to measure slow-flow CSF velocities in healthy controls and normal tension glaucoma patients between the intracranial cavity and the subarachnoid space of the optic nerve. Prospective observational study. Eleven age-matched healthy volunteers and 15 normal tension glaucoma patients. Using phase contrast images, the phase shift in MRI diffusion images can be used to determine the flow velocity. Flow-range ratio between the intracranial cavity and the subarachnoid space of the optic nerve was calculated. Flow-range ratio between the intracranial cavity and the subarachnoid space of the optic nerve was calculated. First, phantom measurements were provided to validate the slow-flow velocity calculations. Second, flow-range ratio was validated for the healthy controls (0.63 ± 0.05), with the range being similar for the right and left optic nerve (P = 0.1). Statistically significant results were obtained (P flow-range ratio in the optic nerve of healthy controls (n = 22 eyes, 0.63 ± 0.05) with the flow-range ratio in pathological optic nerves (n = 23, 0.55 ± 0.08) of normal tension glaucoma patients. MANOVA revealed no dependency between flow-range ratio and patient dependent variables. Diffusion-weighted imaging provides a method to evaluate CSF flow within the subarachnoid space of the optic nerve in a non-invasive manner. Compared to healthy controls, patients with normal tension glaucoma measure a significantly lower flow-range ratio. This finding suggests a possible role of impaired CSF dynamics in the pathophysiology in normal tension glaucoma. © 2017 Royal Australian and New Zealand College of Ophthalmologists.

  4. Thermal Recovery from Cold-Working in Type K Bare-Wire Thermocouples

    Science.gov (United States)

    Greenen, A. D.; Webster, E. S.

    2017-12-01

    Cold-working of most thermocouples has a significant, direct impact on the Seebeck coefficient which can lead to regions of thermoelectric inhomogeneity and accelerated drift. Cold-working can occur during the wire swaging process, when winding the wire onto a bobbin, or during handling by the end user—either accidentally or deliberately. Swaging-induced cold-work in thermocouples, if uniformly applied, may result in a high level of homogeneity. However, on exposure to elevated temperatures, the subsequent recovery process from the cold-working can then result in significant drift, and this can in turn lead to erroneous temperature measurements, often in excess of the specified manufacturer tolerances. Several studies have investigated the effects of cold-work in Type K thermocouples usually by bending, or swaging. However, the amount of cold-work applied to the thermocouple is often difficult to quantify, as the mechanisms for applying the strains are typically nonlinear when applied in this fashion. A repeatable level of cold-working is applied to the different wires using a tensional loading apparatus to apply a known yield displacement to the thermoelements. The effects of thermal recovery from cold-working can then be accurately quantified as a function of temperature, using a linear gradient furnace and a high-resolution homogeneity scanner. Variation in these effects due to differing alloy compositions in Type K wire is also explored, which is obtained by sourcing wire from a selection of manufacturers. The information gathered in this way will inform users of Type K thermocouples about the potential consequences of varying levels of cold-working and its impact on the Seebeck coefficient at a range of temperatures between ˜ 70°C and 600° C. This study will also guide users on the temperatures required to rapidly alleviate the effects of cold-working using thermal annealing treatments.

  5. Adsorção e propriedades de volume de misturas binárias água álcool: um experimento didático com base em medidas de tensão superficial An undergraduate experiment in physical chemistry: adsorption and bulk properties of alcohol-water mixtures based on surface tension measurements

    Directory of Open Access Journals (Sweden)

    Michelly C. dos Santos

    2010-01-01

    Full Text Available An undergraduate physical chemistry experiment based on the drop counting method for surface tension measurements is proposed to demonstrate adsorption isotherms of binary aqueous solutions of ethanol, n-propanol, and n-butanol. Excess surface is obtained by the derivative of surface tension taken with respect to alcohol activity, after this activity calculation using van Laar equation. Laboratory class contents are surface tension, excess surface, percolation of hydrogen bonds, micelle, activity, and ideal solution.

  6. Adsorção e propriedades de volume de misturas binárias água álcool: um experimento didático com base em medidas de tensão superficial An undergraduate experiment in physical chemistry: adsorption and bulk properties of alcohol-water mixtures based on surface tension measurements

    OpenAIRE

    Michelly C. dos Santos; Moraes,Aline P.; Lemes,Maykon A.; Lima, Emília C. D.; Oliveira, Anselmo E.

    2010-01-01

    An undergraduate physical chemistry experiment based on the drop counting method for surface tension measurements is proposed to demonstrate adsorption isotherms of binary aqueous solutions of ethanol, n-propanol, and n-butanol. Excess surface is obtained by the derivative of surface tension taken with respect to alcohol activity, after this activity calculation using van Laar equation. Laboratory class contents are surface tension, excess surface, percolation of hydrogen bonds, micelle, acti...

  7. Assessment and reduction of diaphragmatic tension during hiatal hernia repair.

    Science.gov (United States)

    Bradley, Daniel Davila; Louie, Brian E; Farivar, Alexander S; Wilshire, Candice L; Baik, Peter U; Aye, Ralph W

    2015-04-01

    During hiatal hernia repair there are two vectors of tension: axial and radial. An optimal repair minimizes the tension along these vectors. Radial tension is not easily recognized. There are no simple maneuvers like measuring length that facilitate assessment of radial tension. The aims of this project were to: (1) establish a simple intraoperative method to evaluate baseline tension of the diaphragmatic hiatal muscle closure; and, (2) assess if tension is reduced by relaxing maneuvers and if so, to what degree. Diaphragmatic characteristics and tension were assessed during hiatal hernia repair with a tension gage. We compared tension measured after hiatal dissection and after relaxing maneuvers were performed. Sixty-four patients (29 M:35F) underwent laparoscopic hiatal hernia repair. Baseline hiatal width was 2.84 cm and tension 13.6 dag. There was a positive correlation between hiatal width and tension (r = 0.55) but the strength of association was low (r (2) = 0.31). Four different hiatal shapes (slit, teardrop, "D", and oval) were identified and appear to influence tension and the need for relaxing incision. Tension was reduced by 35.8 % after a left pleurotomy (12 patients); by 46.2 % after a right crural relaxing incision (15 patients); and by 56.1 % if both maneuvers were performed (6 patients). Tension on the diaphragmatic hiatus can be measured with a novel device. There was a limited correlation with width of the hiatal opening. Relaxing maneuvers such as a left pleurotomy or a right crural relaxing incision reduced tension. Longer term follow-up will determine whether outcomes are improved by quantifying and reducing radial tension.

  8. Optic nerve oxygen tension

    DEFF Research Database (Denmark)

    la Cour, M; Kiilgaard, Jens Folke; Eysteinsson, T

    2000-01-01

    To investigate the influence of acute changes in intraocular pressure on the oxygen tension in the vicinity of the optic nerve head under control conditions and after intravenous administration of 500 mg of the carbonic anhydrase inhibitor dorzolamide....

  9. Tension-filled Governance?

    DEFF Research Database (Denmark)

    Celik, Tim Holst

    on the statesituated tension-filled functional relationship between legitimation and accumulation, the study both historically and theoretically reworks this approach and reapplies it for the post-1970s/1990s governance period. It asks whether and to what extent governance has served as a distinctive post- 1970s/1990s...... state-facilitated way of bridging/altering the tension-filled relationship between legitimation and fiscal accumulation in Western European liberal-capitalist democratic polities....

  10. Optic nerve oxygen tension

    DEFF Research Database (Denmark)

    la Cour, M; Kiilgaard, Jens Folke; Eysteinsson, T

    2000-01-01

    To investigate the influence of acute changes in intraocular pressure on the oxygen tension in the vicinity of the optic nerve head under control conditions and after intravenous administration of 500 mg of the carbonic anhydrase inhibitor dorzolamide.......To investigate the influence of acute changes in intraocular pressure on the oxygen tension in the vicinity of the optic nerve head under control conditions and after intravenous administration of 500 mg of the carbonic anhydrase inhibitor dorzolamide....

  11. Ultrathin Nanocrystalline Magnetic Wires

    Directory of Open Access Journals (Sweden)

    Horia Chiriac

    2017-02-01

    Full Text Available The magnetic characteristics of FINEMET type glass-coated nanowires and submicron wires are investigated by taking into account the structural evolution induced by specific annealing all the way from a fully amorphous state to a nanocrystalline structure. The differences between the magnetic properties of these ultrathin wires and those of the thicker glass-coated microwires and “conventional” wires with similar structures have been emphasized and explained phenomenologically. The domain wall propagation in these novel nanowires and submicron wires, featuring a combination between an amorphous and a crystalline structure, has also been studied, given the recent interest in the preparation and investigation of new materials suitable for the development of domain wall logic applications.

  12. Dual wire weld feed proportioner

    Science.gov (United States)

    Nugent, R. E.

    1968-01-01

    Dual feed mechanism enables proportioning of two different weld feed wires during automated TIG welding to produce a weld alloy deposit of the desired composition. The wires are fed into the weld simultaneously. The relative feed rates of the wires and the wire diameters determine the weld deposit composition.

  13. The effect of vesicle shape, line tension, and lateral tension on membrane-binding proteins

    Science.gov (United States)

    Hutchison, Jaime B.

    Model membranes allow for the exploration of complex biological phenomena with simple, controllable components. In this thesis we employ model membranes to determine the effect of vesicle properties such as line tension, lateral tension, and shape on membrane-binding proteins. We find that line tension at the boundary between domains in a phase separated vesicle can accumulate model membrane-binding proteins (green fluorescent protein with a histidine tag), and that those proteins can, in turn, alter vesicle shape. These results suggest that domains in biological membranes may enhance the local concentration of membrane-bound proteins and thus alter protein function. We also explore how membrane mechanical and chemical properties alter the function of the N-BAR domain of amphiphysin, a membrane-binding protein implicated in endocytosis. We find that negatively charged lipids are necessary for N-BAR binding to membranes at detectable levels, and that, at least for some lipid species, binding may be cooperative. Measurements of N-BAR binding as a function of vesicle tension reveal that modest membrane tension of around 2 mN/m, corresponding to a strain of around 1%, strongly increases N-BAR binding. We attribute this increase in binding with tension to the insertion of N-BAR's N-terminal amphipathic helix into the membrane which increases the membrane area. We propose that N-BAR, which was previously described as being able to sense membrane curvature, may be sensing strain instead. Measurements of membrane deformation by N-BAR as a function of membrane tension reveal that tension can hinder membrane deformation. Thus, tension may favor N-BAR binding yet suppress membrane deformation/tubulation, which requires work against tension. These results suggest that membrane tension, a parameter that is often not controlled in model membranes but is tightly controlled in biological cells, may be important in regulating protein binding and assembly and, hence, protein

  14. Social Reproduction and Political Change in The Wire

    DEFF Research Database (Denmark)

    Jensen, Mikkel Bo Brendstrup

    2017-01-01

    This paper examines a core tension in the political television serial The Wire (2002-2008). While several critics have argued that this show is both “bleak” and “systemic” in its portrayal of contemporary society, this paper argues that it is useful to understand these textual elements as building...... blocks in The Wire’s attempt to create a coherent and consistent political argument. The paper argues that had The Wire been structured as a more uplifting and redeeming story, the systemic nature of its societal criticism would be undercut and the show would not embrace the logical consequence...... of the politics it espouses....

  15. Copper wire bonding

    CERN Document Server

    Chauhan, Preeti S; Zhong, ZhaoWei; Pecht, Michael G

    2014-01-01

    This critical volume provides an in-depth presentation of copper wire bonding technologies, processes and equipment, along with the economic benefits and risks.  Due to the increasing cost of materials used to make electronic components, the electronics industry has been rapidly moving from high cost gold to significantly lower cost copper as a wire bonding material.  However, copper wire bonding has several process and reliability concerns due to its material properties.  Copper Wire Bonding book lays out the challenges involved in replacing gold with copper as a wire bond material, and includes the bonding process changes—bond force, electric flame off, current and ultrasonic energy optimization, and bonding tools and equipment changes for first and second bond formation.  In addition, the bond–pad metallurgies and the use of bare and palladium-coated copper wires on aluminum are presented, and gold, nickel and palladium surface finishes are discussed.  The book also discusses best practices and re...

  16. Prediction of multi performance characteristics of wire EDM process using grey ANFIS

    Science.gov (United States)

    Kumanan, Somasundaram; Nair, Anish

    2017-09-01

    Super alloys are used to fabricate components in ultra-supercritical power plants. These hard to machine materials are processed using non-traditional machining methods like Wire cut electrical discharge machining and needs attention. This paper details about multi performance optimization of wire EDM process using Grey ANFIS. Experiments are designed to establish the performance characteristics of wire EDM such as surface roughness, material removal rate, wire wear rate and geometric tolerances. The control parameters are pulse on time, pulse off time, current, voltage, flushing pressure, wire tension, table feed and wire speed. Grey relational analysis is employed to optimise the multi objectives. Analysis of variance of the grey grades is used to identify the critical parameters. A regression model is developed and used to generate datasets for the training of proposed adaptive neuro fuzzy inference system. The developed prediction model is tested for its prediction ability.

  17. Accurate measurements of vadose zone fluxes using automated equilibrium tension plate lysimeters: A synopsis of results from the Spydia research facility, New Zealand.

    Science.gov (United States)

    Wöhling, Thomas; Barkle, Greg; Stenger, Roland; Moorhead, Brian; Wall, Aaron; Clague, Juliet

    2014-05-01

    Automated equilibrium tension plate lysimeters (AETLs) are arguably the most accurate method to measure unsaturated water and contaminant fluxes below the root zone at the scale of up to 1 m². The AETL technique utilizes a porous sintered stainless-steel plate to provide a comparatively large sampling area with a continuously controlled vacuum that is in "equilibrium" with the surrounding vadose zone matric pressure to ensure measured fluxes represent those under undisturbed conditions. This novel lysimeter technique was used at an intensive research site for investigations of contaminant pathways from the land surface to the groundwater on a sheep and beef farm under pastoral land use in the Tutaeuaua subcatchment, New Zealand. The Spydia research facility was constructed in 2005 and was fully operational between 2006 and 2011. Extending from a central access caisson, 15 separately controlled AETLs with 0.2 m² surface area were installed at five depths between 0.4 m and 5.1 m into the undisturbed volcanic vadose zone materials. The unique setup of the facility ensured minimum interference of the experimental equipment and external factors with the measurements. Over the period of more than five years, a comprehensive data set was collected at each of the 15 AETL locations which comprises of time series of soil water flux, pressure head, volumetric water contents, and soil temperature. The soil water was regularly analysed for EC, pH, dissolved carbon, various nitrogen compounds (including nitrate, ammonia, and organic N), phosphorus, bromide, chloride, sulphate, silica, and a range of other major ions, as well as for various metals. Climate data was measured directly at the site (rainfall) and a climate station at 500m distance. The shallow groundwater was sampled at three different depths directly from the Spydia caisson and at various observation wells surrounding the facility. Two tracer experiments were conducted at the site in 2009 and 2010. In the 2009

  18. Membrane tension and membrane fusion

    OpenAIRE

    Kozlov, Michael M.; Chernomordik, Leonid V.

    2015-01-01

    Diverse cell biological processes that involve shaping and remodeling of cell membranes are regulated by membrane lateral tension. Here we focus on the role of tension in driving membrane fusion. We discuss the physics of membrane tension, forces that can generate the tension in plasma membrane of a cell, and the hypothesis that tension powers expansion of membrane fusion pores in late stages of cell-to-cell and exocytotic fusion. We propose that fusion pore expansion can require unusually la...

  19. The PS Booster Fast Wire Scanner

    CERN Document Server

    Burger, S; Priestnall, K; Raich, U

    2003-01-01

    The very tight emittance budget for LHC type beams makes precise emittance measurements in the injector complex a necessity. The PS machine uses 2 fast wire scanners per transverse plane for emittance measurement of the circulating beams. In order to ease comparison the same type of wire scanners have been newly installed in the upstream machine, the PS Booster, where each of the 4 rings is equipped with 2 wire scanners measuring the horizontal and vertical profiles. Those wire scanners use new and more modern control and readout electronics featuring dedicated intelligent motor movement controllers, which relieves the very stringent real time constraints due to the very high speed of 20m/s. In order to be able to measure primary beams at the very low injection energy of the Booster (50MeV) secondary emission currents from the wire can be measured as well as secondary particle flows at higher primary particle energies during and after acceleration. The solution adopted for the control of the devices is descri...

  20. MEASUREMENT OF BLOOD FLOW IN ARTERIA MENINGEA MEDIA OF PATIENTS WITH FREQUENT EPISODIC TENSION-TYPE HEADACHE NOT ASSOCIATED WITH PERICRANIAL TENDERNESS

    OpenAIRE

    A.A. Skoromets; L.G. Zaslavsky; E.P. Evdoshenko

    2008-01-01

    Twenty seven patients with frequent episodic tension-type headache not associated with pericrania! tenderness (TTH) aged from 18 to 69 years old were examined. Arteria meningea media (AMM) and brachiocephalic arteries (BCA) were examined by supersonic power Doppler scanning during the paroxysm of headache and without the paroxysm of headache. Results: Blood flow in AMM of patients with TTH was significantly different during the paroxysm of headache and without the paroxysm of headache (p<0...

  1. Surface Tension of Spacetime

    Science.gov (United States)

    Perko, Howard

    2017-01-01

    Concepts from physical chemistry and more specifically surface tension are introduced to spacetime. Lagrangian equations of motion for membranes of curved spacetime manifold are derived. The equations of motion in spatial directions are dispersion equations and can be rearranged to Schrodinger's equation where Plank's constant is related to membrane elastic modulus. The equation of motion in the time-direction has two immediately recognizable solutions: electromagnetic waves and corpuscles. The corpuscular membrane solution can assume different genus depending on quantized amounts of surface energy. A metric tensor that relates empty flat spacetime to energetic curved spacetime is found that satisfies general relativity. Application of the surface tension to quantum electrodynamics and implications for quantum chromodynamics are discussed. Although much work remains, it is suggested that spacetime surface tension may provide a classical explanation that combines general relativity with field theories in quantum mechanics and atomic particle physics.

  2. Induced Voltage in an Open Wire

    Science.gov (United States)

    Morawetz, K.; Gilbert, M.; Trupp, A.

    2017-07-01

    A puzzle arising from Faraday's law has been considered and solved concerning the question which voltage will be induced in an open wire with a time-varying homogeneous magnetic field. In contrast to closed wires where the voltage is determined by the time variance of the magnetic field and the enclosed area, in an open wire we have to integrate the electric field along the wire. It is found that the longitudinal electric field with respect to the wave vector contributes with 1/3 and the transverse field with 2/3 to the induced voltage. In order to find the electric fields the sources of the magnetic fields are necessary to know. The representation of a spatially homogeneous and time-varying magnetic field implies unavoidably a certain symmetry point or symmetry line which depend on the geometry of the source. As a consequence the induced voltage of an open wire is found to be the area covered with respect to this symmetry line or point perpendicular to the magnetic field. This in turn allows to find the symmetry points of a magnetic field source by measuring the voltage of an open wire placed with different angles in the magnetic field. We present exactly solvable models of the Maxwell equations for a symmetry point and for a symmetry line, respectively. The results are applicable to open circuit problems like corrosion and for astrophysical applications.

  3. Applying hot-wire anemometry to directly measure the water balance in a proton exchange membrane fuel cell for a pre-humidified hydrogen stream

    DEFF Research Database (Denmark)

    Berning, Torsten; Shakhshir, Saher Al

    2016-01-01

    In a recent publication it has been shown how the water balance in a proton exchange membrane fuel cell can be determined employing hot wire anemometry. The hot wire sensor has to be placed into the anode outlet pipe of the operating fuel cell, and the voltage signal E that is read from the sensor....... Finally, it will be shown how previously developed dew point diagrams for the anode side in a fuel cell can be corrected for a humidified hydrogen inlet stream....... has to be divided by a pre-determined voltage signal E0 that has been obtained for a stream of dry hydrogen where the molar flow rate corresponds to a total current I of the fuel cell stack and a stoichiometric flow ratio, ξ. Because the last two properties are usually continuously known in fuel cell...

  4. Medidas de tensão superficial pelo método de contagem de gotas: descrição do método e experimentos com tensoativos não-iônicos etoxilados Surface tension measurement by drop counting method: method description and experiments with etoxilated non-ionic surfactants

    Directory of Open Access Journals (Sweden)

    Érico Teixeira Neto

    2009-01-01

    Full Text Available Surface tension knowledge of surfactants aqueous solutions is important during amphiphilic molecule manufacturing and new product development, as feedback information to handle synthesis parameters to target performance. Drop counting method is an interesting simplification of drop weight method for surface tension measurements. A simple laboratory measurement device, with capability for temperature control, was assembled to allow investigation of ethoxylated surfactants. The implementation of the method was preceded by a detailed investigation of two factors that may affect the measured surface tension: drop formation velocity and surfactant ethoxylation degree. The limitations of the method are discussed on this basis.

  5. Plasma modes in superconducting wires: Optimized experimental configuration

    Energy Technology Data Exchange (ETDEWEB)

    Camarota, B.; Parage, F.; Wooldridge, I.; Delsing, P.; Buisson, O.

    2000-03-01

    An experimental configuration is analyzed in order to study plasma modes in a superconducting wire deposited onto SrTiO{sub 3}. A dispersion relation has been derived by evaluating the effect of environment surrounding the wire. It corresponds to the one-dimensional dispersion law predicted for an isolated superconducting wire. Preliminary measurements are presented. They show 1D plasma modes in the optimized experimental configuration here studied.

  6. Wire core reactor for NTP

    Science.gov (United States)

    Harty, R. B.

    1991-01-01

    The development of the wire core system for Nuclear Thermal Propulsion (NTP) that took place from 1963 to 1965 is discussed. A wire core consists of a fuel wire with spacer wires. It's an annular flow core having a central control rod. There are actually four of these, with beryllium solid reflectors on both ends and all the way around. Much of the information on the concept is given in viewgraph form. Viewgraphs are presented on design details of the wire core, the engine design, engine weight vs. thrust, a technique used to fabricate the wire fuel element, and axial temperature distribution.

  7. Tensions generated in a lateral fabellotibial suture model. Comparison of methods of application of tension, fixation of tension and suture material.

    Science.gov (United States)

    Burton, A F; Horstman, C; Mason, D R

    2015-01-01

    To compare suture tension on a simulated lateral fabellotibial suture model using various methods of application of tension, fixation, and suture materials. Veterinarians constructed simulated lateral fabellotibial suture constructs on a tying stand with a force sensor. Participants used combinations of 45 kg test monofilament nylon, metric 7 braided polyethylene, crimps, crimper, or knots, with their choice of instruments to secure the constructs. The tension in completed constructs was measured and comparisons were made between nylon and polyethylene, the use of crimps compared to knots, and the use of a mechanical distractor compared to hand tightening techniques. A value of p tensions generated ranged from 1.4-171.0N. The median tension of nylon sutures (43.9N ± 44.7N) was significantly greater than polyethylene sutures (9.5 N ± 19.6N). The median tension of constructs secured with crimps (62.8N ± 42.4N) was significantly greater than constructs secured with knots (11.8 N ± 14.8N). The mechanical distractor generated significantly higher median tension (78N ± 50.4N), compared to methods without the device (18.6 N ± 25.1N). There was a large variability in the tension generated in simulated lateral fabellotibial constructs. Veterinarians who used nylon, crimps, and the mechanical tensioner generated constructs with greater tensions.

  8. Tension-type headache

    DEFF Research Database (Denmark)

    Bendtsen, Lars; Jensen, Rigmor

    2009-01-01

    The substantial societal and individual burdens associated with tension-type headache (TTH) constitute a previously overlooked major public health issue. TTH is prevalent, affecting up to 78% of the general population, and 3% suffer from chronic TTH. Pericranial myofascial nociception probably...

  9. Optic nerve oxygen tension

    DEFF Research Database (Denmark)

    Kiilgaard, Jens Folke; Pedersen, D B; Eysteinsson, T

    2004-01-01

    The authors have previously reported that carbonic anhydrase inhibitors such as acetazolamide and dorzolamide raise optic nerve oxygen tension (ONPO(2)) in pigs. The purpose of the present study was to investigate whether timolol, which belongs to another group of glaucoma drugs called beta...

  10. Rein tension during canter

    NARCIS (Netherlands)

    Egenvall, Agneta; Eisersiö, Marie; Rhodin, Marie; van Weeren, P.R.|info:eu-repo/dai/nl/074628550; Roepstorff, Lars

    2015-01-01

    Riders generally use reins as a means for communication with the horse. At present, the signalling pattern is poorly understood. The aim of this study was to illustrate and analyse the rein tension patterns in a number of rider/horse combinations across a variety of exercises in the canter gait. Our

  11. Modern wiring practice

    CERN Document Server

    Steward, W E

    2012-01-01

    Continuously in print since 1952, Modern Wiring Practice has now been fully revised to provide an up-to-date source of reference to building services design and installation in the 21st century. This compact and practical guide addresses wiring systems design and electrical installation together in one volume, creating a comprehensive overview of the whole process for contractors and architects, as well as electricians and other installation engineers. Best practice is incorporated throughout, combining theory and practice with clear and accessible explanation, all

  12. Wiring and lighting

    CERN Document Server

    Kitcher, Chris

    2013-01-01

    Wiring and Lighting provides a comprehensive guide to DIY wiring around the home. It sets out the regulations and legal requirements surrounding electrical installation work, giving clear guidelines that will enable the reader to understand what electrical work they are able to carry out, and what the testing and certification requirements are once the work is completed. Topics covered include: Different types of circuits; Types of cables and cable installation under floors and through joists; Isolating, earthing and bonding; Accessory boxes and fixings; Voltage bands; Detailed advice on safe

  13. Electric wiring domestic

    CERN Document Server

    Coker, A J

    1992-01-01

    Electric Wiring: Domestic, Tenth Edition, is a clear and reliable guide to the practical aspects of domestic electric wiring. Intended for electrical contractors, installation engineers, wiremen and students, its aim is to provide essential up to date information on modern methods and materials in a simple, clear, and concise manner. The main changes in this edition are those necessary to bring the work into line with the 16th Edition of the Regulations for Electrical Installations issued by the Institution of Electrical Engineers. The book begins by introducing the basic features of domestic

  14. Surface tension of spherical drops from surface of tension

    Energy Technology Data Exchange (ETDEWEB)

    Homman, A.-A.; Bourasseau, E. [CEA/DAM DIF, F-91297 Arpajon Cedex (France); Stoltz, G. [Université Paris-Est, CERMICS (ENPC), INRIA, F-77455 Marne-la-Vallée (France); Malfreyt, P. [Institut de Chimie de Clermont-Ferrand, Université Blaise Pascal, UMR CNRS 6296, ICCF, BP 10448, F-63000 Clermont-Ferrand (France); Strafella, L.; Ghoufi, A., E-mail: aziz.ghoufi@univ-rennes1.fr [Institut de Physique de Rennes, Université de Rennes 1 UMR 6251 CNRS, 263 avenue Général Leclerc, 35042 Rennes (France)

    2014-01-21

    The determination of surface tension of curved interfaces is a topic that raised many controversies during the last century. Explicit liquid-vapor interface modelling (ELVI) was unable up to now to reproduce interfacial behaviors in drops due to ambiguities in the mechanical definition of the surface tension. In this work, we propose a thermodynamic approach based on the location of surface of tension and its use in the Laplace equation to extract the surface tension of spherical interfaces from ELVI modelling.

  15. Percutaneous Kirschner wire (K-wire) fixation for humerus shaft ...

    African Journals Online (AJOL)

    In the present study, Kirschner wires (K-wire) were used to achieve a closed intramedullary fixation of humeral shaft fractures. The objective of this study was to evaluate the efficacy of intramedullary K-wires for the treatment of humeral shaft fracture in children. Patients and Methods: This prospective study was conducted in ...

  16. Interchip link system using an optical wiring method.

    Science.gov (United States)

    Cho, In-Kui; Ryu, Jin-Hwa; Jeong, Myung-Yung

    2008-08-15

    A chip-scale optical link system is presented with a transmitter/receiver and optical wire link. The interchip link system consists of a metal optical bench, a printed circuit board module, a driver/receiver integrated circuit, a vertical cavity surface-emitting laser/photodiode array, and an optical wire link composed of plastic optical fibers (POFs). We have developed a downsized POF and an optical wiring method that allows on-site installation with a simple annealing as optical wiring technologies for achieving high-density optical interchip interconnection within such devices. Successful data transfer measurements are presented.

  17. Wiring for space applications program

    Science.gov (United States)

    Hammoud, Ahmad

    1994-01-01

    The insulation testing and analysis consists of: identifying and prioritizing NASA wiring requirements; selecting candidate wiring constructions; developing test matrix and formulating test program; managing, coordinating, and conducting tests; and analyzing and documenting data, establishing guidelines and recommendations.

  18. Debate: Wired versus Wireless.

    Science.gov (United States)

    Meeks, Glenn; Nair, Prakash

    2000-01-01

    Debates the issue of investing in wiring schools for desktop computer networks versus using laptops and wireless networks. Included are cost considerations and the value of technology for learning. Suggestions include using wireless networks for existing schools, hardwiring computers for new construction, and not using computers for elementary…

  19. Wired vs. Wireless.

    Science.gov (United States)

    Fielding, Randall

    2000-01-01

    Presents a debate on which technology will be in tomorrow's classrooms and the pros and cons of wiring classrooms and using a wireless network. Concluding comments address the likelihood, and desirability, of placing computers throughout the entire educational process and what types of computers and capabilities are needed. (GR)

  20. Wired to freedom

    DEFF Research Database (Denmark)

    Jepsen, Kim Sune Karrasch; Bertilsson, Margareta

    2017-01-01

    dimension of life science through a notion of public politics adopted from the political theory of John Dewey. We show how cochlear implantation engages different social imaginaries on the collective and individual levels and we suggest that users share an imaginary of being “wired to freedom” that involves...

  1. Gaseous wire detectors

    Energy Technology Data Exchange (ETDEWEB)

    Va' vra, J.

    1997-08-01

    This article represents a series of three lectures describing topics needed to understand the design of typical gaseous wire detectors used in large high energy physics experiments; including the electrostatic design, drift of electrons in the electric and magnetic field, the avalanche, signal creation, limits on the position accuracy as well as some problems one encounters in practical operations.

  2. 3D Wire 2015

    DEFF Research Database (Denmark)

    Jordi, Moréton; F, Escribano; J. L., Farias

    This document is a general report on the implementation of gamification in 3D Wire 2015 event. As the second gamification experience in this event, we have delved deeply in the previous objectives (attracting public areas less frequented exhibition in previous years and enhance networking) and have...

  3. Surface Tension and Capillary Rise

    Science.gov (United States)

    Walton, Alan J.

    1972-01-01

    Discussion of the shortcomings of textbook explanations of surface tension, distinguishing between concepts of tension and capillary rise. The arguments require only a clear understanding of Newtonian mechanics, notably potential energy. (DF)

  4. Practical wiring in SI units

    CERN Document Server

    Miller, Henry A

    2013-01-01

    Practical Wiring, Volume 1 is a 13-chapter book that first describes some of the common hand tools used in connection with sheathed wiring. Subsequent chapters discuss the safety in wiring, cables, conductor terminations, insulating sheathed wiring, conductor sizes, and consumer's control equipments. Other chapters center on socket outlets, plugs, lighting subcircuits, lighting accessories, bells, and primary and secondary cells. This book will be very valuable to students involved in this field of interest.

  5. Wire EDM for Refractory Materials

    Science.gov (United States)

    Zellars, G. R.; Harris, F. E.; Lowell, C. E.; Pollman, W. M.; Rys, V. J.; Wills, R. J.

    1982-01-01

    In an attempt to reduce fabrication time and costs, Wire Electrical Discharge Machine (Wire EDM) method was investigated as tool for fabricating matched blade roots and disk slots. Eight high-strength nickel-base superalloys were used. Computer-controlled Wire EDM technique provided high quality surfaces with excellent dimensional tolerances. Wire EDM method offers potential for substantial reductions in fabrication costs for "hard to machine" alloys and electrically conductive materials in specific high-precision applications.

  6. Measure of thermal neutron flux in the IPEN/MB-01 reactor using {sup 197} Au wire activation detectors; Medida do fluxo de neutrons termicos do reator IPEN/MB-01 com detectores de ativacao de fios de {sup 197} Au

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Andre Luis Ferreira

    1995-12-31

    This dissertation has aimed at developing a neutron flux measurement technique by means of detectors activation analysis. The main task of this work was the implementation of this thermal neutron flux measurement technique, using gold wires as activation detectors in the IPEN/MB-01 reactor core. The neutron thermal flux spatial distribution was obtained by gold wire activation technique, with wire diameters of 0.125 mm and 0.250 mm in seven selected reactor experimental channels. The values of thermal flux were about 10{sup 9} neutrons/cm{sup 2}.s. This experiment has been the first one conducted with gold wires in the IPEN/MB-01 reactor, being this technique implemented for use by experiments in flux mapping of the core 73 refs., 60 figs., 31 tabs.

  7. The Cartesian Diver, Surface Tension and the Cheerios Effect

    Science.gov (United States)

    Chen, Chi-Tung; Lee, Wen-Tang; Kao, Sung-Kai

    2014-01-01

    A Cartesian diver can be used to measure the surface tension of a liquid to a certain extent. The surface tension measurement is related to the two critical pressures at which the diver is about to sink and about to emerge. After sinking because of increasing pressure, the diver is repulsed to the centre of the vessel. After the pressure is…

  8. Surface Tension Screen Failure Detection Method and Apparatus.

    Science.gov (United States)

    Apparatus for detecting failure of a surface tension screen disposed between a holding chamber and a main chamber of a tank includes a fixture for...Comparison of the measurements provides an assessment of the integrity of the surface tension screen. If the measurements are significantly different

  9. Hysteretic behavior of a belt tensioner: modeling and experimental investigation

    OpenAIRE

    Michon, Guilhem; Manin, Lionel; Dufour, Regis

    2005-01-01

    In this paper we describe the modeling of the hysteretic behavior of belt tensioners. An initial experimental device is composed only of the tensioner by using forcing frequencies, preloads and deflection amplitudes. It permits the identification of the parameters of the restoring force model used. Comparison of the measured and predicted force deflection loops of the tensioner subjected to large deflections permits preliminary validation of the model.The second experimental device consists o...

  10. Mechanical optimisation of a high-precision fast wire scanner at CERN

    CERN Document Server

    Samuelsson, Sebastian; Veness, Raymond

    Wire scanners are instruments used to measure the transverse beam prole in particle accelerators by passing a thin wire through the particle beam. To avoid the issues of vacuum leakage through the bellows and wire failure related to current designs of wire scanners, a new concept for a wire scanner has been developed at CERN. This design has all moving parts inside the beam vacuum and has a nominal wire scanning speed of 20 m/s. The demands on the design associated with this together with the high precision requirements create a need for\

  11. Carbon speciation and surface tension of fog

    Science.gov (United States)

    Capel, P.D.; Gunde, R.; Zurcher, F.; Giger, W.

    1990-01-01

    The speciation of carbon (dissolved/particulate, organic/inorganic) and surface tension of a number of radiation fogs from the urban area of Zurich, Switzerland, were measured. The carbon species were dominated by "dissolved" organic carbon (DOC; i.e., the fraction that passes through a filter), which was typically present at levels of 40-200 mg/L. Less than 10% of the DOC was identified as specific individual organic compounds. Particulate organic carbon (POC) accounted for 26-41% of the mass of the particles, but usually less than 10% of the total organic carbon mass. Inorganic carbon species were relatively minor. The surface tensions of all the measured samples were less than pure water and were correlated with their DOC concentrations. The combination of high DOC and POC and low surface tension suggests a mechanism for the concentration of hydrophobic organic contaminants in the fog droplet, which have been observed by numerous investigators. ?? 1990 American Chemical Society.

  12. MEASUREMENT OF BLOOD FLOW IN ARTERIA MENINGEA MEDIA OF PATIENTS WITH FREQUENT EPISODIC TENSION-TYPE HEADACHE NOT ASSOCIATED WITH PERICRANIAL TENDERNESS

    Directory of Open Access Journals (Sweden)

    A.A. Skoromets

    2008-06-01

    Full Text Available Twenty seven patients with frequent episodic tension-type headache not associated with pericrania! tenderness (TTH aged from 18 to 69 years old were examined. Arteria meningea media (AMM and brachiocephalic arteries (BCA were examined by supersonic power Doppler scanning during the paroxysm of headache and without the paroxysm of headache. Results: Blood flow in AMM of patients with TTH was significantly different during the paroxysm of headache and without the paroxysm of headache (p<0.01. Blood flow in arteria carotid external did not change (p>0.05. The pattern of hypoperfusion in AMM was displayed in two groups during the paroxysm of headache. The increase of average blood velocity (TAmx in groups of patients with TTH in comparison with the control group.

  13. Wire scanner software and firmware issues

    Energy Technology Data Exchange (ETDEWEB)

    Gilpatrick, John Doug [Los Alamos National Laboratory

    2008-01-01

    The Los Alamos Neutron Science Center facility presently has 110 slow wire scanning profile measurement instruments located along its various beam lines. These wire scanners were developed and have been operating for at least 30 years. While the wire scanners solved many problems to operate and have served the facility well they have increasingly suffered from several problems or limitations, such as maintenance and reliability problems, antiquated components, slow data acquisition, and etc. In order to refurbish these devices, these wire scanners will be replaced with newer versions. The replacement will consist of a completely new beam line actuator, new cables, new electronics and brand new software and firmware. This note describes the functions and modes of operation that LabVIEW VI software on the real time controller and FPGA LabVIEW firmware will be required. It will be especially interesting to understand the overall architecture of these LabVIEW VIs. While this note will endeavor to describe all of the requirements and issues for the wire scanners, undoubtedly, there will be missing details that will be added as time progresses.

  14. Well-defined critical association concentration and rapid adsorption at the air/water interface of a short amphiphilic polymer, amphipol A8-35: a study by Förster resonance energy transfer and dynamic surface tension measurements.

    Science.gov (United States)

    Giusti, Fabrice; Popot, Jean-Luc; Tribet, Christophe

    2012-07-17

    Amphipols (APols) are short amphiphilic polymers designed to handle membrane proteins (MPs) in aqueous solutions as an alternative to small surfactants (detergents). APols adsorb onto the transmembrane, hydrophobic surface of MPs, forming small, water-soluble complexes, in which the protein is biochemically stabilized. At variance with MP/detergent complexes, MP/APol ones remain stable even at extreme dilutions. Pure APol solutions self-associate into well-defined micelle-like globules comprising a few APol molecules, a rather unusual behavior for amphiphilic polymers, which typically form ill-defined assemblies. The best characterized APol to date, A8-35, is a random copolymer of acrylic acid, isopropylacrylamide, and octylacrylamide. In the present work, the concentration threshold for self-association of A8-35 in salty buffer (NaCl 100 mM, Tris/HCl 20 mM, pH 8.0) has been studied by Förster resonance energy transfer (FRET) measurements and tensiometry. In a 1:1 mol/mol mixture of APols grafted with either rhodamine or 7-nitro-1,2,3-benzoxadiazole, the FRET signal as a function of A8-35 concentration is essentially zero below a threshold concentration of 0.002 g·L(-1) and increases linearly with concentration above this threshold. This indicates that assembly takes place in a narrow concentration interval around 0.002 g·L(-1). Surface tension measurements decreases regularly with concentration until a threshold of ca. 0.004 g·L(-1), beyond which it reaches a plateau at ca. 30 mN·m(-1). Within experimental uncertainties, the two techniques thus yield a comparable estimate of the critical self-assembly concentration. The kinetics of variation of the surface tension was analyzed by dynamic surface tension measurements in the time window 10 ms-100 s. The rate of surface tension decrease was similar in solutions of A8-35 and of the anionic surfactant sodium dodecylsulfate when both compounds were at a similar molar concentration of n-alkyl moieties. Overall, the

  15. Tension optimization of the conductor-and-support cable elements during stranding process

    Directory of Open Access Journals (Sweden)

    I.M. Chayun

    2016-12-01

    Full Text Available Steel lifting ropes, cables and other similar products are rod statically undeterminable prestressed structures. Preliminary deformations of their elements (wires are caused by their manufacturing technology. Wires suffer stretching, bending with torsion in a stage of elastoplastic deformation. In this work the mechanic-mathematical model of residual forces determination in the wires of polymetallic conductor-and-support cable is offered. Aim: The aim of the work is studying of the mechanical and mathematical model defining residual forces in the wires of conductor-and-support cable and also the optimization of parameters of a twist by the criterion of residual forces lack after production process finishing. Materials and methods: The method developed by the authors earlier to the study the strain-stressed state of twisted wire products off-loading from technological internal forces has been applied to assess the impact of the approximate value of the longitudinal stiffness of the product. In this paper, each wire is considered as an element of the product individually. This is necessary to investigate the impact of uneven wire tensions on defects of conductor-and-support cable (out-of-straight in a free state and stripping-down. Results: On the basis of the conducted deformation studies of conductor-and-support cable during off-loading process from twist tension of its elements the dependencies of residual forces on the level and interrelation of elements tension has been determined. The condition of ensuring of zero residual forces in the wires of conductor-and-support cable after production is formulated. It was found that calculated values of residual forces are almost identical when using of the approximate and exact values of longitudinal stiffness of conductor-and-support cable.

  16. Wire chambers revisited.

    Science.gov (United States)

    Ott, R J

    1993-04-01

    Detectors used for radioisotope imaging have, historically, been based on scintillating crystal/photomultiplier combinations in various forms. From the rectilinear scanner through to modern gamma cameras and positron cameras, the basic technology has remained much the same. Efforts to overcome the limitations of this form of technology have foundered on the inability to reproduce the required sensitivity, spatial resolution and sensitive area at acceptable cost. Multiwire proportional chambers (MWPCs) have long been used as position-sensitive charged particle detectors in nuclear and high-energy physics. MWPCs are large-area gas-filled ionisation chambers in which large arrays of fine wires are used to measure the position of ionisation produced in the gas by the passage of charged particles. The important properties of MWPCs are high-spatial-resolution, large-area, high-count-rate performance at low cost. For research applications, detectors several metres square have been built and small-area detectors have a charged particle resolution of 0.4 mm at a count rate of several million per second. Modification is required to MWPCs for nuclear medicine imaging. As gamma rays or X-rays cannot be detected directly, they must be converted into photo- or Compton scatter electrons. Photon-electron conversion requires the use of high atomic number materials in the body of the chamber. Pressurised xenon is the most useful form of "gas only" photon-electron convertor and has been used successfully in a gamma camera for the detection of gamma rays at energies below 100 keV. This camera has been developed specifically for high-count-rate first-pass cardiac imaging. This high-pressure xenon gas MWPC is the key to a highly competitive system which can outperform scintillator-based systems. The count rate performance is close to a million counts per second and the intrinsic spatial resolution is better than the best scintillator-based camera. The MWPC camera produces quantitative

  17. Obelix Wire Chamber

    CERN Multimedia

    1986-01-01

    Two wire chambers made originally for the R807 Experiment at CERN's Intersecting Storage Rings. In 1986 they were used for the PS 201 experiment (Obelix Experiment) at LEAR, the Low Energy Antiproton Ring. The group of researchers from Turin, using the chambers at that time, changed the acquisition system using for the first time 8 bit (10 bit non linear) analog to digital conversion for incoming signals from the chambers. The acquisition system was controlled by 54 CPU and 80 digital signal processors. The power required for all the electronics was 40 kW. For the period, this system was one of the most powerful on-line apparatus in the world. The Obelix Experiment was closed in 1996. To find more about how a wire chamber works, see the description for object CERN-OBJ-DE-038.

  18. Effect of respiratory physiotherapy on arterial oxygen tension.

    Science.gov (United States)

    Hedstrand, U; Liw, M; Rooth, G; Ogren, C H

    1978-01-01

    The effect of deep breathing on arterial oxygen tension was investigated in 45 postoperative patients. Arterial oxygen tension was estimated by the transcutaneous oxygen tension method, which allows continuous non-invasive measurement of the arterial oxygen tension changes. Three deep breaths in 1 min, assisted by three respiratory therapy devices, were compared to a standard physiotherapy programme. A peak increase in arterial oxygen tension of 3--4.5 mmHg occurred after 1 min, and significantly increased values were seen for 2--4 min following deep breathing with the three respiratory devices. From the various physiotherapeutic procedures, verbally and manually assisted deep breathing gave a 7 mmHg PO2 peak and significantly increased values for 6 min. The sign mechanism is discussed in the light of the present knowledge of airway closure, which gives a satisfactory explanation of the short-lasting increase in oxygen tension.

  19. Cable tensioned membrane solar collector module with variable tension control

    Science.gov (United States)

    Murphy, Lawrence M.

    1985-01-01

    Disclosed is a solar collector comprising a membrane for concentrating sunlight, a plurality of elongated structural members for suspending the membrane member thereon, and a plurality of control members for adjustably tensioning the membrane member, as well as for controlling a focus produced by the membrane members. Each control member is disposed at a different corresponding one of the plurality of structural members. The collector also comprises an elongated flexible tensioning member, which serves to stretch the membrane member and to thereafter hold it in tension, and a plurality of sleeve members, which serve to provide the membrane member with a desired surface contour during tensioning of the membrane member. The tensioning member is coupled to the structural members such that the tensioning member is adjustably tensioned through the structural members. The tensioning member is also coupled to the membrane member through the sleeve members such that the sleeve members uniformly and symmetrically stretch the membrane member upon applying tension to the tensioning member with the control members.

  20. Capacitance Control on the Wire Production Line

    Directory of Open Access Journals (Sweden)

    Goldshtein Alexander

    2016-01-01

    Full Text Available The paper presents technical implementation of the electricalcapacitive method to perform in-process measurement of the capacitance per unit length of a single-core electric wire. The design of the electrocapacitive measuring transducer is proposed. The block diagram of the device CAP-10 developed to implement the proposed method is presented. The appearance of the device CAP-10 is showed, and its operating principle is described. It is shown that the change in water conductivity has a significant impact of the measurement result of the wire capacitance per unit length. The techniques to offset from the impact of water conductivity variation on measurement results are proposed. The technique of the device CAP-10 initial adjustment is proposed. It provides the desired function of the output signal transformation. The technique of the ‘operating’ adjustment to correct measurement results through systematic measurement error elimination is offered.

  1. Carbon nanotube wires with continuous current rating exceeding 20 Amperes

    Science.gov (United States)

    Cress, Cory D.; Ganter, Matthew J.; Schauerman, Christopher M.; Soule, Karen; Rossi, Jamie E.; Lawlor, Colleen C.; Puchades, Ivan; Ubnoske, Stephen M.; Bucossi, Andrew R.; Landi, Brian J.

    2017-07-01

    A process to fabricate carbon nanotube (CNT) wires with diameters greater than 1 cm and continuous current carrying capability exceeding 20 A is demonstrated. Wires larger than 5 mm are formed using a multi-step radial densification process that begins with a densified CNT wire core followed by successive wrapping of additional CNT material to increase the wire size. This process allows for a wide range of wire diameters to be fabricated, with and without potassium tetrabromoaurate (KAuBr4) chemical doping, and the resulting electrical and thermal properties to be characterized. Electrical measurements are performed with on/off current steps to obtain the maximum current before reaching a peak CNT wire temperature of 100 °C and before failure, yielding values of instantaneous currents in excess of 45 A for KAuBr4 doped CNT wires with a diameter of 6 mm achieved prior to failure. The peak temperature of the wires at failure (˜530 °C) is correlated with the primary decomposition peak observed in thermal gravimetric analysis of a wire sample confirming that oxidation is the primary failure mode of CNT wires operated in air. The in operando stability of doped CNT wires is confirmed by monitoring the resistance and temperature, which remain largely unaltered over 40 days and 1 day for wires with 1.5 mm and 11.2 mm diameters, respectively. The 100 °C continuous current rating, or ampacity, is measured for a range of doped CNT wire diameters and corresponding linear mass densities ρL. To describe the results, a new form of the fuse-law, where the critical current is defined as I ∝ρL3 /4, is developed and shows good agreement with the experimental data. Ultimately, CNT wires are shown to be stable electrical conductors, with failure current densities in excess of 50 A in the case of a convectively cooled 11.2 mm doped CNT wire, and amenable for use in applications that have long-term, high-current demands.

  2. Wire grid polarizers for visible wavelengths

    Science.gov (United States)

    Johnson, Joshua Hans

    Detailed analysis of wire-grid (WG) polarizers for visible wavelengths is presented. Rigorous coupled-wave analysis (RCWA) is used to model their performance. The optimum choice of metal for the wires is identified, and the effects of different substrate indices of refraction are considered. The polarization properties are considered with changes in the physical parameters, including period, duty cycle, and wire thickness. It is shown that the performance of WG polarizers improves with increasing angle of incidence. The effect of non-square wire profiles is considered, as is the effect of adding additional dielectric layers between the wires and the substrate. The effect of metal oxide layers forming on the wires is also modeled. While most of this work concerns WG polarizers used in transmission, the performance in reflection is also discussed. Several visible-wavelength WG polarizers were fabricated at the Cornell Nanofabrication Facility (CNF) in Ithaca, NY. Electron-beam lithography was used to write the patterns for these devices, and two different methods of pattern transfer were compared. These were the lift-off method and reactive-ion etching (RIE). We found that lift-off could not produce wires thick enough for good polarization properties. RIE could produce much thicker wires with good profiles and was used for all of the experimental work presented here. Two different methods for metal film deposition, evaporation and sputtering were also compared. Films deposited by sputtering were found to have much lower indices of refraction and to not respond to etching as well. Thermally evaporated films performed much better in WG polarizers. Alternative methods for the mass-production of visible-wavelength WG polarizers are also discussed. The performance of the fabricated WG polarizers is compared to theory. When the measured physical parameters are used in RCWA to predict the performance, the measured extinction ratio is found to be much lower than the

  3. Surface tension-driven convection phenomena

    Science.gov (United States)

    Mann, J. A., Jr.

    1980-01-01

    The techniques for measuring surface tension-driven flow are reported. In addition to the fairly standard crossed beam LDV method, methods using ripplon scattering which do not require seeding of the fluid were developed. These methods can be used to determine thermophysical properties of the surface, such as surface tension, viscosity, and local temperature. This technique was utilized to observe the change in surface tension associated with the nematic to isotropic phase transition of para-azoxydianisole at 134 C. The ripplon scattering methods become difficult for surface velocities below 1 mm/sec because of the overlapping spectra. Careful analysis procedures could extend this to smaller flows, but the more conventional LDV techniques with seeded flows are the method of choice for slow flows.

  4. A study of the regional load deflection rate of multiloop edgewise arch wire.

    Science.gov (United States)

    Yang, W S; Kim, B H; Kim, Y H

    2001-04-01

    To quantify the unique mechanical properties of multiloop edgewise arch wire (MEAW), its load deflection rate (LDR) and the LDR of various arch wires in the individual interbracket span were measured and compared. The MEAW arch wires were made out of .016 x .022-inch Permachrome stainless steel wire with L-loops of 4 different sizes. Five samples of each size were prepared for the comparison against wires of plain stainless steel, TMA, and nickel-titanium (NiTi) wires, all of the same dimensions. Five specimens for each of the various wires were used to eliminate the possibility of change in the physical properties of wires caused by the stress from repeated measurement. The LDR was measured by using the Instron model 4466 at a crosshead speed of 1 mm/min and maximum deflection of 1.0 mm. The regional wire stiffness of MEAW was calculated from the LDR in the interbracket spans that were measured by the Instron. The findings were as follows: (1) The LDR of the L-loop of MEAW at an individual interbracket span rate was 1:7.54 of the plain stainless steel wire, 1:1.76 of the NiTi, and 1:2.72 of TMA. (2) The L-loop at an individual interbracket span showed much lower wire stiffness than the entire arch wire, and the value of the stiffness differed according to the region.

  5. Tensile Properties of the Individual Phases in Unreacted Multifilament Nb3Sn Wires

    CERN Document Server

    Scheuerlein, C; Fedelich, B; Finn, M; Griepentrog, M; El-Kallassi, P; Lecouturier, F; Oberli, L; Rehmer, B; Sgobba, Stefano; Thilly, L; Vidal, V

    2007-01-01

    The room temperature elastic and plastic properties under uniaxial tensile loading of the different phases of an un-reacted, internal-tin process, Nb3Sn wire have been determined by tensile tests of whole wires and of extracted Ta, Nb and Nb alloy filaments, as well as by indentation hardness measurements in metallographic wire cross sections.

  6. Revisiting Tension Band Fixation for Difficult Patellar Fractures.

    Science.gov (United States)

    Hambright, Dustin S; Walley, Kempland C; Hall, Amber; Appleton, Paul T; Rodriguez, Edward K

    2017-02-01

    Patella fractures with comminution, osteoporotic bone, and/or previously failed fixation are exceedingly difficult to reduce and fix. Moreover, the risk of symptomatic constructs and patients who are poorly compliant with postoperative activity restrictions can make these complex fracture patterns an even more challenging scenario. Although there is an array of techniques described for comminuted patella fractures, there lacks an accepted surgical technique for these difficult cases. In this clinical series, we describe an enhancement to the traditional tension band construct that uses additional wires and multiple tension bands to gather and fix comminuted fracture patterns in nontransverse planes, bolster osteoporotic bone, and secure fractures in patients undergoing a revision and/or have potential to be poorly compliant with postoperative activity restrictions. The clinical outcomes of 27 patients demonstrate high rates of bony union, functional range of motion, and low rates of both infection and failure. In conclusion, using the basic principles of tension band wiring remains highly versatile, useful, and economical in approaching difficult patella fractures.

  7. Dual wire welding torch and method

    Science.gov (United States)

    Diez, Fernando Martinez; Stump, Kevin S.; Ludewig, Howard W.; Kilty, Alan L.; Robinson, Matthew M.; Egland, Keith M.

    2009-04-28

    A welding torch includes a nozzle with a first welding wire guide configured to orient a first welding wire in a first welding wire orientation, and a second welding wire guide configured to orient a second welding wire in a second welding wire orientation that is non-coplanar and divergent with respect to the first welding wire orientation. A method of welding includes moving a welding torch with respect to a workpiece joint to be welded. During moving the welding torch, a first welding wire is fed through a first welding wire guide defining a first welding wire orientation and a second welding wire is fed through a second welding wire guide defining a second welding wire orientation that is divergent and non-coplanar with respect to the first welding wire orientation.

  8. Social Reproduction and Political Change in The Wire

    DEFF Research Database (Denmark)

    Jensen, Mikkel Bo Brendstrup

    2017-01-01

    This paper examines a core tension in the political television serial The Wire (2002-2008). While several critics have argued that this show is both “bleak” and “systemic” in its portrayal of contemporary society, this paper argues that it is useful to understand these textual elements as buildin...

  9. Metering Wheel-Wire Track Wire Boom Deployment Mechanism

    Science.gov (United States)

    Granoff, Mark S.

    2014-01-01

    The NASA MMS Spin Plane Double Probe (SDP) Deployer utilizes a helical path, rotating Metering Wheel and a spring loaded Wire "Holding" Track to pay out a "fixed end" 57 meter x 1.5 mm diameter Wire Boom stored between concentric storage cylinders. Unlike rotating spool type storage devices, the storage cylinders remain stationary, and the boom wire is uncoiled along the length of the cylinder via the rotation of the Metering Wheel. This uncoiling action avoids the need for slip-ring contacts since the ends of the wire can remain stationary. Conventional fixed electrical connectors (Micro-D type) are used to terminate to operational electronics.

  10. Review of wire chamber aging

    Energy Technology Data Exchange (ETDEWEB)

    Va' Vra, J.

    1986-02-01

    This paper makes an overview of the wire chamber aging problems as a function of various chamber design parameters. It emphasizes the chemistry point of view and many examples are drawn from the plasma chemistry field as a guidance for a possible effort in the wire chamber field. The paper emphasizes the necessity of variable tuning, the importance of purity of the wire chamber environment, as well as it provides a practical list of presently known recommendations. In addition, several models of the wire chamber aging are qualitatively discussed. The paper is based on a summary talk given at the Wire Chamber Aging Workshop held at LBL, Berkeley on January 16-17, 1986. Presented also at Wire Chamber Conference, Vienna, February 25-28, 1986. 74 refs., 18 figs., 11 tabs.

  11. In-situ tensile testing of notched poly- and oligocrystalline 316L wires

    Energy Technology Data Exchange (ETDEWEB)

    Mitevski, Bojan [Materials Science and Engineering (ITM), Duisburg (Germany); Weiss, Sabine [Brandenburg Technical Univ., Cottbus-Senftenberg (Germany). Chair of Physical Metallurgy and Materials Science.; Fischer, Alfons [Duisburg-Essen Univ. (Germany). Materials Science and Engineering; Rush Univ. Medical Center, Chicago, IL (United States). Dept. of Orthopedics

    2017-03-01

    In-situ testing inside a scanning electron microscope is a helpful tool for detailed analyses of small sized specimens with respect to their mechanical properties and the correlated microstructural alterations. Thus, this test method is used to analyze the tensional properties of thin 316L (1.4441) wires used for microscale components, e.g., like coronary artery stents. Tensile tests were conducted on unnotched and circularly notched 316L wires (oe 0.95 mm) with a special focus on the number of grains within the cross section as well as the notch geometry. Four combinations of notch width (2 and 4 mm) and notch depth (diameter at notch root: 0.5 and 0.75 mm) were chosen. Notch depth and notch shape were adjusted by means of electrochemical polishing. Previous investigations showed, that oligocrystalline structures exhibit a different mechanical behavior compared to polycrystalline ones or single crystals. There are only a few data available on mechanical testing of oligocrystalline structures with respect to varying notch geometries. Depending on the notch geometry, grain size and, therefore, the number of grains within the notch cross section widely scattering yield- and tensile strength as well as failure elongation values were measured. However, the transition criterion between poly- and oligocrystalline behavior could be quantified to be 6 to 7 grains within the cross section.

  12. Torque resistance of different stainless steel wires commonly used for fixed retainers in orthodontics

    DEFF Research Database (Denmark)

    Arnold, Dario; Dalstra, Michel; Verna, Carlalberta

    2016-01-01

    retainers in orthodontics. Materials and Methods: Torquing moments acting on a retainer wire were measured in a mechanical force testing system by applying buccal crown torque to an upper lateral incisor in both a 3-teeth and in a 2-teeth setup. Seven stainless steel wires with different shape, type (plain......Objective: Movements of teeth splinted by fixed retention wires after orthodontic treatment have been observed. The aetiological factors for these movements are unknown. The aim of this in vitro study was to compare the resistance to torque of different stainless steel wires commonly used for fixed...... or a braided 0.016 × 0.022-inch stainless steel wire. A tooth attached by a retainer wire to only one neighbouring tooth is less resistant to torque than a tooth connected to two neighbouring teeth. Annealing a retainer wire with a flame reduces the stiffness of the wire markedly and can lead to a non...

  13. Comparison of frictional forces between aesthetic orthodontic coated wires and self-ligation brackets.

    Science.gov (United States)

    Kim, Yunmi; Cha, Jung-Yul; Hwang, Chung-Ju; Yu, Hyung Seog; Tahk, Seon Gun

    2014-07-01

    The purpose of this study was to evaluate the clinical efficacy of polymer- and rhodium-coated wires compared to uncoated wires by measuring the frictional forces using self-ligation brackets. 0.016-inch nickel titanium (NiTi) wires and 0.017 × 0.025-inch stainless steel (SS) wires were used, and the angulations between the brackets and wires were set to 0°, 5°, and 10°. Upper maxillary premolar brackets (Clippy-C®) with a 0.022-inch slot were selected for the study and a tensile test was performed with a crosshead speed of 5 mm/min. The maximum static frictional forces and kinetic frictional forces were recorded and compared. The maximum static frictional forces and the kinetic frictional forces of coated wires were equal to or higher than those of the uncoated wires (p forces of rhodium-coated wires were significantly higher than those of polymer-coated wires when the angulations between the brackets and wires were set to (i) 5° in the 0.016-inch NiTi wires and (ii) all angulations in the 0.017 × 0.025-inch SS wires (p forces of rhodium-coated wires were higher than those of polymer-coated wires, except when the angulations were set to 0° in the 0.016-inch NiTi wires (p forces of the coated wires with regards to aesthetics were equal to or greater than those of the uncoated wires, a study under similar conditions regarding the oral cavity is needed in order to establish the clinical implications.

  14. Wiring regulations in brief

    CERN Document Server

    Tricker, Ray

    2012-01-01

    Tired of trawling through the Wiring Regs?Perplexed by Part P?Confused by cables, conductors and circuits?Then look no further! This handy guide provides an on-the-job reference source for Electricians, Designers, Service Engineers, Inspectors, Builders, Students, DIY enthusiastsTopic-based chapters link areas of working practice - such as cables, installations, testing and inspection, special locations - with the specifics of the Regulations themselves. This allows quick and easy identification of the official requirements relating to the situati

  15. Planck and the local Universe: quantifying the tension

    CERN Document Server

    Verde, Licia; Protopapas, Pavlos

    2013-01-01

    We use the latest Planck constraints, and in particular constraints on the derived parameters (Hubble constant and age of the Universe) for the local universe and compare them with local measurements of the same quantities. We propose a way to quantify whether cosmological parameters constraints from two different experiments are in tension or not. Our statistic, T, is an evidence ratio and therefore can be interpreted with the widely used Jeffrey's scale. We find that in the framework of the LCDM model, the Planck inferred two dimensional, joint, posterior distribution for the Hubble constant and age of the Universe is in "strong" tension with the local measurements; the odds being ~ 1:50. We explore several possibilities for explaining this tension and examine the consequences both in terms of unknown errors and deviations from the LCDM model. In some one-parameter LCDM model extensions, tension is reduced whereas in other extensions, tension is instead increased. In particular, small total neutrino masses ...

  16. Holding the Tension.

    Science.gov (United States)

    Feudtner, Chris

    2016-05-01

    My colleagues and I had been asked by a member of a clinical team to help sort through the ethics of stopping a life-sustaining intervention for a very ill child. We had already talked with the parents, the physicians, and the folks from nursing, social work, and chaplaincy. Terms like "suffering," "cruel," "compassion," and "moral distress" had been uttered, as had terms like "inappropriate," "unethical," "neglectful," and "risk-management." The group had now stuffed all of these polarizing thoughts and feelings into this cramped room with only one door. And everyone was looking at me. What skill, competency, or inner capacity must one possess to hold and manage such tension? © 2016 The Hastings Center.

  17. Corrosion of Wires on Wooden Wire-Bound Packaging Crates

    Science.gov (United States)

    Samuel L. Zelinka; Stan Lebow

    2015-01-01

    Wire-bound packaging crates are used by the US Army to transport materials. Because these crates may be exposed to harsh environments, they are dip-treated with a wood preservative (biocide treatment). For many years, zinc-naphthenate was the most commonly used preservative for these packaging crates and few corrosion problems with the wires were observed. Recently,...

  18. A microprocessor based portable bolt tension monitor

    Science.gov (United States)

    Perey, D. F.

    1991-01-01

    A bolt tension monitor (BTM) which uses ultrasonics and a pulsed phase locked loop circuit to measure load-induced acoustic phase shifts which are independent of friction is described. The BTM makes it possible to measure the load in a bolt that was tightened at some time in the past. This capability to recertify a load after-the-fact will help to insure the integrity of a bolted joint.

  19. Measurement of Thermal Conductivities of Two Cryoprotective Agent Solutions for Vitreous Cryopreservation of Organs at the Temperature Range of 77 K-300 K Using a Thermal Sensor Made of Microscale Enamel Copper Wire.

    Science.gov (United States)

    Li, Yufang; Zhao, Gang; Hossain, S M Chapal; Panhwar, Fazil; Sun, Wenyu; Kong, Fei; Zang, Chuanbao; Jiang, Zhendong

    2017-06-01

    Biobanking of organs by cryopreservation is an enabling technology for organ transplantation. Compared with the conventional slow freezing method, vitreous cryopreservation has been regarded to be a more promising approach for long-term storage of organs. The major challenges to vitrification are devitrification and recrystallization during the warming process, and high concentrations of cryoprotective agents (CPAs) induced metabolic and osmotic injuries. For a theoretical model based optimization of vitrification, thermal properties of CPA solutions are indispensable. In this study, the thermal conductivities of M22 and vitrification solution containing ethylene glycol and dimethyl sulfoxide (two commonly used vitrification solutions) were measured using a self-made microscaled hot probe with enameled copper wire at the temperature range of 77 K-300 K. The data obtained by this study will further enrich knowledge of the thermal properties for CPA solutions at low temperatures, as is of primary importance for optimization of vitrification.

  20. Quasi-continuous parallel online scattered light, fluorescence and dissolved oxygen tension measurement combined with monitoring of the oxygen transfer rate in each well of a shaken microtiter plate.

    Science.gov (United States)

    Ladner, Tobias; Held, Markus; Flitsch, David; Beckers, Mario; Büchs, Jochen

    2016-12-03

    Microtiter plates (MTP) are often applied as culture vessels in high-throughput screening programs. If online measuring techniques are available, MTPs can also be applied in the first steps of process development. For such small-scale bioreactors dipping probes are usually too large; therefore, optical measurements are often used. For example, the BioLector technology allows for the online monitoring of scattered light and fluorescence in each well of a continuously orbitally shaken MTP. Although this system provides valuable data, these measurements are mainly of a semi-quantitative nature. Therefore, signal calibration is required to obtain absolute values. With the µRAMOS technology it became possible for the first time to quantify the oxygen transfer rate (OTR) separately in each well of an MTP. In this work, a device is presented that combines both techniques, to provide a hitherto unparalleled high amount of information from each single well. Because both systems (BioLector and µRAMOS) are based on optical measurements, the measurements need to be synchronized to avoid interferences with the optical signals. The new experimental setup was applied for online monitoring in cultures of Escherichia coli and Hansenula polymorpha. It has been demonstrated that the well-to-well reproducibility is very high, and that the monitored signals provide reliable and valuable information about the process. With varying filling volumes, different maximum oxygen transfer capacities (OTR max ) were adjusted in oxygen-limited cultures. The different degrees of stress during the culture due to oxygen limitation affected microbial growth and also impacted reproducibility from culture to culture. Furthermore, it was demonstrated that this new device significantly simplifies the experimental efforts: instead of parallel cultures in a shake flask and MTP, just one single experiment in MTP needs to be conducted to measure the OTR, dissolved oxygen tension (DOT), scattered light and

  1. Ablation dynamics in coiled wire-array Z-pinches

    Energy Technology Data Exchange (ETDEWEB)

    Hall, G. N.; Lebedev, S. V.; Suzuki-Vidal, F.; Swadling, G.; Chittenden, J. P.; Bland, S. N.; Harvey-Thompson, A. [Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom); Knapp, P. F.; Blesener, I. C.; McBride, R. D.; Chalenski, D. A.; Blesener, K. S.; Greenly, J. B.; Pikuz, S. A.; Shelkovenko, T. A.; Hammer, D. A.; Kusse, B. R. [Laboratory of Plasma Studies, Cornell University, 439 Rhodes Hall, Ithaca, New York 14853 (United States)

    2013-02-15

    Experiments to study the ablation dynamics of coiled wire arrays were performed on the MAGPIE generator (1 MA, 240 ns) at Imperial College, and on the COBRA generator at Cornell University's Laboratory of Plasma Studies (1 MA, 100 ns). The MAGPIE generator was used to drive coiled wires in an inverse array configuration to study the distribution of ablated plasma. Using interferometry to study the plasma distribution during the ablation phase, absolute quantitative measurements of electron line density demonstrated very high density contrasts between coiled ablation streams and inter-stream regions many millimetres from the wire. The measured density contrasts for a coiled array were many times greater than that observed for a conventional array with straight wires, indicating that a much greater axial modulation of the ablated plasma may be responsible for the unique implosion dynamics of coiled arrays. Experiments on the COBRA generator were used to study the complex redirection of plasma around a coiled wire that gives rise to the ablation structure exhibited by coiled arrays. Observations of this complex 3D plasma structure were used to validate the current model of coiled array ablation dynamics [Hall et al., Phys. Rev. Lett. 100, 065003 (2008)], demonstrating irrefutably that plasma flow from the wires behaves as predicted. Coiled wires were observed to ablate and implode in the same manner on both machines, indicating that current rise time should not be an issue for the scaling of coiled arrays to larger machines with fast current rise times.

  2. i>The Wire and the Disenchantment of the Outsider

    DEFF Research Database (Denmark)

    Jensen, Mikkel Bo Brendstrup

    2019-01-01

    of the outsider in an effort to gain legitimacy for themselves but in the analysis of selected characters from the show – Omar Little, Jimmy McNulty, and Stringer Bell – it is shown that these characters all are outsiders in different ways and that the show tries to debunk the charisma of the outsider......This article presents a contextualist reading of the television serial The Wire (2002-2008). Drawing on Grace Hale’s A Nation of Outsiders (2011), the article argues that there is a tension between this show and its paratexts in the way that the creators of the show embrace an outsider rhetoric...... while the show tries to deromanticize the trope of the outsider. Drawing on Hale, the article accounts for the cultural context that The Wire engages with and then proceeds to examine the paratexts around the show. The article argues that the producers of the show wholeheartedly embrace the romance...

  3. New sensitive micro-measurements of dynamic surface tension and diffusion coefficients: Validated and tested for the adsorption of 1-Octanol at a microscopic air-water interface and its dissolution into water.

    Science.gov (United States)

    Kinoshita, Koji; Parra, Elisa; Needham, David

    2017-02-15

    Currently available dynamic surface tension (DST) measurement methods, such as Wilhelmy plate, droplet- or bubble-based methods, still have various experimental limitations such as the large size of the interface, convection in the solution, or a certain "dead time" at initial measurement. These limitations create inconsistencies for the kinetic analysis of surfactant adsorption/desorption, especially significant for ionic surfactants. Here, the "micropipette interfacial area-expansion method" was introduced and validated as a new DST measurement having a high enough sensitivity to detect diffusion controlled molecular adsorption at the air-water interfaces. To validate the new technique, the diffusion coefficient of 1-Octanol in water was investigated with existing models: the Ward Tordai model for the long time adsorption regime (1-100s), and the Langmuir and Frumkin adsorption isotherm models for surface excess concentration. We found that the measured diffusion coefficient of 1-Octanol, 7.2±0.8×10 -6 cm 2 /s, showed excellent agreement with the result from an alternative method, "single microdroplet catching method", to measure the diffusion coefficient from diffusion-controlled microdroplet dissolution, 7.3±0.1×10 -6 cm 2 /s. These new techniques for determining adsorption and diffusion coefficients can apply for a range of surface active molecules, especially the less-characterized ionic surfactants, and biological compounds such as lipids, peptides, and proteins. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Measurement of Thermal Conductivity of Porcine Liver in the Temperature Range of Cryotherapy and Hyperthermia (250~315k) by A Thermal Sensor Made of A Micron-Scale Enameled Copper Wire.

    Science.gov (United States)

    Jiang, Z D; Zhao, G; Lu, G R

      BACKGROUND: Cryotherapy and hyperthermia are effective treatments for several diseases, especially for liver cancers. Thermal conductivity is a significant thermal property for the prediction and guidance of surgical procedure. However, the thermal conductivities of organs and tissues, especially over the temperature range of both cryotherapy and hyperthermia are scarce. To provide comprehensive thermal conductivity of liver for both cryotherapy and hyperthermia. A hot probe made of stain steel needle and micron-sized copper wire is used for measurement. To verify data processing, both the least square method and the Monte Carlo inversion method are used to determine the hot probe constants, respectively, with reference materials of water and 29.9 % Ca2Cl aqueous solution. Then the thermal conductivities of Hanks solution and pork liver bathed in Hanks solution are measured. The effective length for two methods is nearly the same, but the heat capacity of probe calibrated by the Monte Carlo inversion is temperature dependent. Fairly comprehensive thermal conductivity of porcine liver measured with these two methods in the target temperature range is verified to be similar. We provide an integrated thermal conductivity of liver for cryotherapy and hyperthermia in two methods, and make more accurate predictions possible for surgery. The least square method and the Monte Carlo inversion method have their advantages and disadvantages. The least square method is available for measurement of liquids that not prone to convection or solids in a wide temperature range, while the Monte Carlo inversion method is available for accurate and rapid measurement.

  5. Wire chambers with their magnetostrictive readout

    CERN Multimedia

    1974-01-01

    This set of wire chamber planes shaped as a cylinder sector was installed inside the magnet of a polarized spin target modified to allow as well momentum analysis of the produced particles. The experiment (S126) was set up by the CERN-Trieste Collaboration in the PS beam m9 to measure spin effects in the associated production of of a positive kaon and a positive Sigma by interaction of a positive pion with polarized protons.

  6. Cannulated screw and cable are superior to modified tension band in the treatment of transverse patella fractures.

    Science.gov (United States)

    Tian, Yun; Zhou, Fang; Ji, Hongquan; Zhang, Zhishan; Guo, Yan

    2011-12-01

    Although the modified tension band technique (eg, tension band supplemented by longitudinal Kirschner wires) has long been the mainstay for fixation of transverse fractures of the patella, it has shortcomings, such as bad reduction, loosening of implants, and skin irritation. We conducted a retrospective comparison of the modified tension band technique and the titanium cable-cannulated screw tension band technique. We retrospectively reviewed 101 patients aged 22 to 85 years (mean, 56.6 years) with AO/OTA 34-C1 fractures (n = 68) and 34-C2 fractures (n = 33). Fifty-two patients were in the modified tension band group and 49 were in the titanium cable-cannulated screw tension band group. Followup was at least 1 year (range, 1-3 years). Comparison criteria were fracture reduction, fracture healing time, and the Iowa score for knee function. The titanium cable-cannulated screw tension band group showed improved fracture reduction, reduced healing time, and better Iowa score, compared with the modified tension band group. In the modified tension band group, eight patients experienced wire migration, three of these requiring a second operation. There were no complications in the titanium cable-cannulated screw tension band group. The titanium cable-cannulated screw tension band technique showed superior results and should be considered as an alternative method for treatment of transverse patellar fractures. Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

  7. Cognitive function in tension-type headache.

    Science.gov (United States)

    Waldie, Karen E; Welch, David

    2007-12-01

    The association between tension-type headache and cognitive ability was assessed among 971 members of a longitudinal birth cohort study. Primary headache status was determined at age 32 years according to 2004 International Headache Society criteria, frequent childhood headaches were identified from parent report from ages 7 to 13 years, and data relating to cognitive and academic performance from ages 3 to 32 years were analyzed. Adult study members with tension-type headache did not score worse on any of the cognitive measures relative to headache-free controls or headache-free tinnitus sufferers. Instead, a consistent relation was found between childhood headache (regardless of headache diagnosis in adulthood) and lower scores on most cognitive measures from age 3 years through adolescence (verbal and performance IQ, receptive language, and reading scores). The data indicate that cognitive performance deficits in childhood headache sufferers can probably be attributed to factors stemming from utero or early childhood.

  8. Plasma chemistry in wire chambers

    Energy Technology Data Exchange (ETDEWEB)

    Wise, J.

    1990-05-01

    The phenomenology of wire chamber aging is discussed and fundamentals of proportional counters are presented. Free-radical polymerization and plasma polymerization are discussed. The chemistry of wire aging is reviewed. Similarities between wire chamber plasma (>1 atm dc-discharge) and low-pressure rf-discharge plasmas, which have been more widely studied, are suggested. Construction and use of a system to allow study of the plasma reactions occurring in wire chambers is reported. A proportional tube irradiated by an {sup 55}Fe source is used as a model wire chamber. Condensable species in the proportional tube effluent are concentrated in a cryotrap and analyzed by gas chromatography/mass spectrometry. Several different wire chamber gases (methane, argon/methane, ethane, argon/ethane, propane, argon/isobutane) are tested and their reaction products qualitatively identified. For all gases tested except those containing methane, use of hygroscopic filters to remove trace water and oxygen contaminants from the gas resulted in an increase in the average molecular weight of the products, consistent with results from low-pressure rf-discharge plasmas. It is suggested that because water and oxygen inhibit polymer growth in the gas phase that they may also reduce polymer deposition in proportional tubes and therefore retard wire aging processes. Mechanistic implications of the plasma reactions of hydrocarbons with oxygen are suggested. Unresolved issues in this work and proposals for further study are discussed.

  9. Indicator dilutions for hemodynamic purposes. Oxymetry. Percutaneous measurement of O/sub 2/ tension. Radiodiagnosis in intensive care units. Stand-by laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Horvath, M.; Boeszoermenyi, E.; Nemeth, L.; Illes, Zs. (Allami Szivkorhaz, Balatonfuered (Hungary))

    1983-07-01

    The hemodynamic, oxymetric and isotope diagnostic instrumentation of the intensive therapeutic care units and stand-by units of several hospitals in Hungary is critically surveyed. They include nuclear equipment applied in radiocardiography, cardio-respiratic screening, scanning radiocardiography and radiofibrinogen measurements. Instrumentation is discussed in correlation with the clinical importance of the individual diagnostic techniques.

  10. Cerclage wiring technique after proximal femoral fracture in total hip arthroplasty.

    Science.gov (United States)

    Fishkin, Z; Han, S M; Ziv, I

    1999-01-01

    Cerclage wires have been used to stabilize proximal femoral cracks after stem insertion in cementless total hip arthroplasty. The objective of this study was to determine the optimal number and orientation of cerclage wires necessary to prevent stem subsidence and crack propagation. The crack was stabilized by 1, 2, or 3 wires placed either normal to the femoral neck axis or normal to the crack. The femora were compressed to 2,670 N while measuring crack opening and stem subsidence. Wires placed normal to the crack allowed less stem subsidence by 3.17 mm and less crack opening by 1.55 mm compared with wires placed normal to the neck. The addition of multiple wires reduced subsidence by 50% and reduced crack opening to <1 mm. Medial and anterior calcar cracks are best stabilized by at least 2 cerclage wires that are placed normal to the crack.

  11. Microstructures and Mechanical Properties of as-Drawn and Laboratory Annealed Pearlitic Steel Wires

    Science.gov (United States)

    Durgaprasad, A.; Giri, S.; Lenka, S.; Kundu, S.; Mishra, S.; Chandra, S.; Doherty, R. D.; Samajdar, I.

    2017-10-01

    Near eutectoid fully pearlitic wire rod (5.5 mm diameter) was taken through six stages of wire drawing (drawing strains of 0 to 2.47). The as-drawn (AD) wires were further laboratory annealed (LA) to re-austenitize and reform the pearlite. AD and LA grades, for respective wire diameters, had similar pearlite microstructure: interlamellar spacing ( λ) and pearlite alignment with the wire axis. However, LA grade had lower hardness (for both phases) and slightly lower fiber texture and residual stresses in ferrite. Surprisingly, essentially identical tensile yield strengths in AD and LA wires, measured at equivalent spacing, were found. The work hardened AD had, as expected, higher torsional yield strengths and lower tensile and torsional ductilities than LA. In both wires, stronger pearlite alignment gave significantly increased torsional ductility.

  12. Managing tension headaches at home

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000421.htm Managing tension headaches at home To use the sharing ... have glasses, use them. Learn and practice stress management. Some people find relaxation exercises or meditation helpful. ...

  13. Tension pneumocephalus: Mount Fuji sign

    Directory of Open Access Journals (Sweden)

    Pulastya Sanyal

    2015-01-01

    Full Text Available A 13-year-old male was operated for a space occupying lesion in the brain. A noncontrast computed tomography scan done in the late postoperative period showed massive subdural air collection causing compression of bilateral frontal lobes with widening of interhemispheric fissure and the frontal lobes acquiring a peak like configuration - causing tension pneumocephalus-"Mount Fuji sign." Tension pneumocephalus occurs when air enters the extradural or intradural spaces in sufficient volume to exert a mass or pressure effect on the brain, leading to brain herniation. Tension pneumocephalus is a surgical emergency, which needs immediate intervention in the form of decompression of the cranial cavity by a burr hole or needle aspiration. The Mount Fuji sign differentiates tension pneumocephalus from pneumocephalus.

  14. Tension pile study : final report.

    Science.gov (United States)

    1970-07-01

    This report contains the results of a short term study of a pile in tension loads. The piles tested were driven on Louisiana Department of Highway's property in response to preceding research work entitled "Stability of Slender Prestressed Concrete P...

  15. [Effect of bile acids on surface tension of bronchoalveolar lavage fluid in rabbits].

    Science.gov (United States)

    Wang, Fei; Zhao, Cong; Tian, Yinghong; Yin, Yanru

    2014-10-01

    To observe changes in surface tension of bronchoalveolar lavage fluids (BALF) in rabbits with hyperbilirubinemia and the influence of bile diluents and 5 different bile acids on BALF surface tension to provide better insight into the regulatory role of bile acids on respiratory function. Bronchoalveolar lavage with 0.9% normal saline was carried out in 30 male New Zealand rabbits and the surface tensions of BALF were measured. The changes in BALF surface tension was measured in rabbits with hyperbilirubinemia. Different concentrations of bile diluents, normal saline, or water solutions of 5 bile acids were added into the collected BALF to test their influence on the surface tension of BALF. The BALF from rabbits with hyperbilirubinemia showed a significantly increased surface tension (Psurface tension of the BALF by 21.15%, 26.09%, and 19.64%, respectively. Among the water solutions of the 5 bile acids, UDCA produced no significant influence on the surface tension of BALF while CDCA, CA, LCA, and DCA increased the surface tension by 16.10%, 21.66%, 14.21%, and 13.05%, respectively. The surface tension of BALF increases significantly during hyperbilirubinemia. Bile diluents as well as the free bile acids CDCA, CA, LCA and DCA, but not UDCA, can increase the surface tension of BALF, suggesting that these bile acids may emulsify pulmonary alveolar surfactants to increase the alveolar surface tension.

  16. Design and experimental tests of free electron laser wire scanners

    Directory of Open Access Journals (Sweden)

    G. L. Orlandi

    2016-09-01

    Full Text Available SwissFEL is a x-rays free electron laser (FEL driven by a 5.8 GeV linac under construction at Paul Scherrer Institut. In SwissFEL, wire scanners (WSCs will be complementary to view-screens for emittance measurements and routinely used to monitor the transverse profile of the electron beam during FEL operations. The SwissFEL WSC is composed of an in-vacuum beam-probe—motorized by a stepper motor—and an out-vacuum pick-up of the wire signal. The mechanical stability of the WSC in-vacuum hardware has been characterized on a test bench. In particular, the motor induced vibrations of the wire have been measured and mapped for different motor speeds. Electron-beam tests of the entire WSC setup together with different wire materials have been carried out at the 250 MeV SwissFEL Injector Test Facility (SITF, Paul Scherrer Institut, CH and at FERMI (Elettra-Sincrotrone Trieste, Italy. In particular, a comparative study of the relative measurement accuracy and the radiation-dose release of Al(99∶Si(1 and tungsten (W wires has been carried out. On the basis of the outcome of the bench and electron-beam tests, the SwissFEL WSC can be qualified as a high resolution and machine-saving diagnostic tool in consideration of the mechanical stability of the scanning wire at the micrometer level and the choice of the wire material ensuring a drastic reduction of the radiation-dose release with respect to conventional metallic wires. The main aspects of the design, laboratory characterization and electron beam tests of the SwissFEL WSCs are presented.

  17. Design and experimental tests of free electron laser wire scanners

    Science.gov (United States)

    Orlandi, G. L.; Heimgartner, P.; Ischebeck, R.; Loch, C. Ozkan; Trovati, S.; Valitutti, P.; Schlott, V.; Ferianis, M.; Penco, G.

    2016-09-01

    SwissFEL is a x-rays free electron laser (FEL) driven by a 5.8 GeV linac under construction at Paul Scherrer Institut. In SwissFEL, wire scanners (WSCs) will be complementary to view-screens for emittance measurements and routinely used to monitor the transverse profile of the electron beam during FEL operations. The SwissFEL WSC is composed of an in-vacuum beam-probe—motorized by a stepper motor—and an out-vacuum pick-up of the wire signal. The mechanical stability of the WSC in-vacuum hardware has been characterized on a test bench. In particular, the motor induced vibrations of the wire have been measured and mapped for different motor speeds. Electron-beam tests of the entire WSC setup together with different wire materials have been carried out at the 250 MeV SwissFEL Injector Test Facility (SITF, Paul Scherrer Institut, CH) and at FERMI (Elettra-Sincrotrone Trieste, Italy). In particular, a comparative study of the relative measurement accuracy and the radiation-dose release of Al (99 )∶Si (1 ) and tungsten (W) wires has been carried out. On the basis of the outcome of the bench and electron-beam tests, the SwissFEL WSC can be qualified as a high resolution and machine-saving diagnostic tool in consideration of the mechanical stability of the scanning wire at the micrometer level and the choice of the wire material ensuring a drastic reduction of the radiation-dose release with respect to conventional metallic wires. The main aspects of the design, laboratory characterization and electron beam tests of the SwissFEL WSCs are presented.

  18. Conjunctival oxygen tension at high altitude.

    Science.gov (United States)

    Mader, T H; Friedl, K E; Mohr, L C; Bernhard, W N

    1987-01-01

    Transconjunctival oxygen tension (PcjO2) was studied using a hypobaric chamber and during mountaineering excursions. Measurements obtained during acute chamber exposures (15-20 min) at sea level, 1829 m (6,000 ft), 3048 m (10,000 ft), 4267 m (14,000 ft) and return to sea level were (means +/- SEM): 60.1 +/- 2.7, 49.1 +/- 1.8, 38.3 +/- 2.4, 27.4 +/- 1.5, and 61.1 +/- 2.8 mm Hg, respectively (n = 13). The ratio of PcjO2 to arterial blood oxygen tension (PaO2) did not change in a consistent manner between sea level and 4267 m; PcjO2 was 74 +/- 6.9% of PaO2. The 16 subjects participating in the mountaineering phase of the study revealed similar means at sea level and 1829 m (57.4 +/- 2.4 and 46.3 +/- 1.9 mm Hg respectively), but a smaller decrement was observed at 3048 m (43.0 +/- 1.6 mm Hg). The difference between mountain and chamber values may be accounted for by a partial acclimatization to altitude brought about by longer exposure on the mountain excursions. A comparison between PcjO2 and transcutaneous oxygen tension during the chamber study suggests that a greater precision and sensitivity is obtained with measurement of oxygen tension at the conjunctival site. PcjO2 measurement is a non-invasive reflection of PaO2 which is suitable for continuous monitoring during hypoxia studies.

  19. Modeling birds on wires.

    Science.gov (United States)

    Aydoğdu, A; Frasca, P; D'Apice, C; Manzo, R; Thornton, J M; Gachomo, B; Wilson, T; Cheung, B; Tariq, U; Saidel, W; Piccoli, B

    2017-02-21

    In this paper we introduce a mathematical model to study the group dynamics of birds resting on wires. The model is agent-based and postulates attraction-repulsion forces between the interacting birds: the interactions are "topological", in the sense that they involve a given number of neighbors irrespective of their distance. The model is first mathematically analyzed and then simulated to study its main properties: we observe that the model predicts birds to be more widely spaced near the borders of each group. We compare the results from the model with experimental data, derived from the analysis of pictures of pigeons and starlings taken in New Jersey: two different image elaboration protocols allow us to establish a good agreement with the model and to quantify its main parameters. We also discuss the potential handedness of the birds, by analyzing the group organization features and the group dynamics at the arrival of new birds. Finally, we propose a more refined mathematical model that describes landing and departing birds by suitable stochastic processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Keratoconus and normal-tension glaucoma: a study of the possible association with abnormal biomechanical properties as measured by corneal hysteresis (An AOS Thesis).

    Science.gov (United States)

    Cohen, Elisabeth J

    2009-12-01

    To test the hypothesis that keratoconus and pellucid patients who have glaucoma or are suspected of having glaucoma have lower corneal hysteresis (CH) and/or corneal resistance factor (CRF) measurements compared to controls. A prospective study at a tertiary eye center of keratoconus and pellucid patients with glaucoma or suspected of having glaucoma, and age-matched keratoconus and pellucid controls, was performed. After informed consent was obtained, corneal topography, ocular response analyzer measurements, pachymetry, intraocular pressure, A-scan measurements, Humphrey visual fields (VFs), and disc photos were done. Analyses compared cases to controls on primary (CH and CRF) and secondary variables. Disc photos and VFs were rated in a masked fashion. The mean CH (8.2, SD=1.6, vs 8.3, SD=1.5) and CRF (7.3, SD=2.0, vs 6.9, SD=2.1) were low and did not differ significantly between 20 study patients (29 eyes) and 40 control patients (61 eyes), respectively. CH had a negative, significant correlation with maximum corneal curvature by topography (P corneal thickness (P < .003). The mean cup-disc ratio was larger among cases than controls (0.54, SD=0.20, vs 0.38, SD=0.20; P = .003). VFs were suggestive of glaucoma more often among the study eyes than controls (11 of 29, 37.9%, vs 8 of 60, 13.3%; P =.019). CH was low in study and control patients and was correlated with severity of keratoconus/pellucid, but not with glaucoma/suspected glaucoma or control status. Evidence of glaucoma was more common in study eyes than controls, but was present in both.

  1. [Our experience with the measurement of transcutaneous oxygen tension for evaluation of blood circulation in peripheral arteries in patients with critical ischemic disease of lower limbs].

    Science.gov (United States)

    Žižlavský, V; Kubíček, L; Staffa, R

    2015-11-01

    The measurement of transcutaneous oxygen pressure (TcpO2) is a non-invasive method to quantify skin oxygenation at capillary level and their nutritive ability needed to heal the ischemic defect. TcpO2 pressure values below 30 mm Hg are specific for critical limb ischemia and predict complicated healing. The purpose of this study was to verify the cut-off pressure in patient unable to undergo vascular reconstruction, and to verify the possibility of using this method to evaluate the effectiveness of vascular reconstructive surgery. The group included 52 patients (35 men and 17 women). The mean age of patients in the group was 66.5 years (max. 85, min. 44). In our group of patients we confirmed that the TcpO2 values of successfully healed ischemic wounds were equal or greater than 30 mm Hg (mean TcpO2 value at the dorsum of the foot was 37.0 mm Hg ± 9.5 mm Hg), compared to the group of unsuccessfully healed patients whose values were lower (mean TcpO2 value at the dorsum of the foot was 9.0 mm Hg ± 5.3 mm Hg). TcpO2 is a suitable method in predicting the healing of ischemic defects and any possible need for surgical or endovascular revascularization. Thanks to its non-invasive nature and undemanding measurement, it surely helps to make better decisions in choosing the therapeutic procedure needed to heal the defect.

  2. Topology Optimized Photonic Wire Splitters

    DEFF Research Database (Denmark)

    Frandsen, Lars Hagedorn; Borel, Peter Ingo; Jensen, Jakob Søndergaard

    2006-01-01

    Photonic wire splitters have been designed using topology optimization. The splitters have been fabricated in silicon-on-insulator material and display broadband low-loss 3dB splitting in a bandwidth larger than 100 nm.......Photonic wire splitters have been designed using topology optimization. The splitters have been fabricated in silicon-on-insulator material and display broadband low-loss 3dB splitting in a bandwidth larger than 100 nm....

  3. Decompression of tension pneumothoraces in Asian trauma patients: greater success with lateral approach and longer catheter lengths based on computed tomography chest wall measurements.

    Science.gov (United States)

    Goh, S; Xu, W R; Teo, L T

    2017-10-03

    Our study aims to compare the anterior and lateral approaches for needle thoracostomy (NT) and determine the adequacy of catheter lengths used for NT in Asian trauma patients based on computed tomography chest wall measurements. A retrospective review of chest computed tomography scans of 583 Singaporean trauma patients during period of 2011-2015 was conducted. Four measurements of chest wall thickness (CWT) were taken at the second intercostal space, midclavicular line and fifth intercostal space, midaxillary line bilaterally. Measurements were from the superficial skin layer of the chest wall to the pleural space. Successful NT was defined radiologically as CWT ≤ 5 cm. There were 593 eligible subjects. Mean age was 49.1 years (49.1 ± 21.0). Majority were males (77.0%) and Chinese (70.2%). Mean CWT for the anterior approach was 4.04 cm (CI 3.19-4.68) on the left and 3.92 cm (CI 3.17-4.63) on the right. Mean CWT for the lateral approach was 3.52 cm (CI 2.52-4.36) on the left, and 3.62 cm (CI 3.65-4.48) on the right. Mean CWT was shorter in the lateral approach by 0.52 cm on the left and 0.30 cm on the right (p = 0.001). With a 5.0 cm catheter in the anterior approach, 925 out of 1186 sites (78.8%) will have adequate NT as compared to 98.2% with a 7.0 cm catheter. Similarly, in the lateral approach 1046 out of 1186 (88.2%) will have adequate NT as compared to 98.5% with a 7.0 cm catheter. Obese subjects had significantly higher mean CWT in both approaches (p = 0.001). There was moderate correlation between BMI and CWT in the anterior approach, r 2 = 0.529 as compared to the lateral approach, r 2 = 0.244. Needle decompression using the lateral approach or a longer catheter is more likely to succeed in Asian trauma patients. A high BMI is an independent predictor of failure of NT, especially for the anterior as compared to lateral approach.

  4. Wire Array Solar Cells: Fabrication and Photoelectrochemical Studies

    Science.gov (United States)

    Spurgeon, Joshua Michael

    Despite demand for clean energy to reduce our addiction to fossil fuels, the price of these technologies relative to oil and coal has prevented their widespread implementation. Solar energy has enormous potential as a carbon-free resource but is several times the cost of coal-produced electricity, largely because photovoltaics of practical efficiency require high-quality, pure semiconductor materials. To produce current in a planar junction solar cell, an electron or hole generated deep within the material must travel all the way to the junction without recombining. Radial junction, wire array solar cells, however, have the potential to decouple the directions of light absorption and charge-carrier collection so that a semiconductor with a minority-carrier diffusion length shorter than its absorption depth (i.e., a lower quality, potentially cheaper material) can effectively produce current. The axial dimension of the wires is long enough for sufficient optical absorption while the charge-carriers are collected along the shorter radial dimension in a massively parallel array. This thesis explores the wire array solar cell design by developing potentially low-cost fabrication methods and investigating the energy-conversion properties of the arrays in photoelectrochemical cells. The concept was initially investigated with Cd(Se, Te) rod arrays; however, Si was the primary focus of wire array research because its semiconductor properties make low-quality Si an ideal candidate for improvement in a radial geometry. Fabrication routes for Si wire arrays were explored, including the vapor-liquid-solid growth of wires using SiCl4. Uniform, vertically aligned Si wires were demonstrated in a process that permits control of the wire radius, length, and spacing. A technique was developed to transfer these wire arrays into a low-cost, flexible polymer film, and grow multiple subsequent arrays using a single Si(111) substrate. Photoelectrochemical measurements on Si wire array

  5. ONLINE TECHNOLOGICAL MONITORING OF INSULATION DEFECTS IN ENAMELED WIRES

    Directory of Open Access Journals (Sweden)

    V. M. Zolotaryov

    2017-08-01

    Full Text Available In this paper the authors used non-destructive technological monitoring of defects insulation enameled wire with poliimid polymer. The paper is devoted to the statistical method for processing, comparison and analysis of results of measurements of parameters of insulation of enameled wire because of mathematical model of trend for application in active technological monitoring is developed; the recommendations for parameters of such monitoring are used. It is theoretically justified and the possibility of determination of dependence of the error on the velocity of movement of a wire for want of quantifying of defects in enameled insulation by non-destructive tests by high voltage. The dependence of average value of amount of defects for enameled wire with two-sheeted poliimid insulation in a range of nominal diameter 0.56 mm is experimentally determined. The technological monitoring purpose is to reduce the quantifying defects of enameled insulation.

  6. Researching on Control Device of Prestressing Wire Reinforcement

    Science.gov (United States)

    Si, Jianhui; Guo, Yangbo; Liu, Maoshe

    2017-06-01

    This paper mainly introduces a device for controlling prestress and its related research methods, the advantage of this method is that the reinforcement process is easy to operate and control the prestress of wire rope accurately. The relationship between the stress and strain of the steel wire rope is monitored during the experiment, and the one - to - one relationship between the controllable position and the pretightening force of the steel wire rope is confirmed by the 5mm steel wire rope, and the results are analyzed theoretically by the measured elastic modulus. The results show that the method can effectively control the prestressing force, and the result provides a reference method for strengthening the concrete column with prestressed steel strand.

  7. Keratoconus and normal-tension glaucoma: a study of the possible association with abnormal biomechanical properties as measured by corneal hysteresis.

    Science.gov (United States)

    Cohen, Elisabeth J; Myers, Jonathan S

    2010-09-01

    To test the hypothesis that patients with keratoconus and pellucid who have glaucoma or are glaucoma suspects have lower corneal hysteresis (CH) and/or corneal resistance factor (CRF) measurements compared with controls. A prospective study at a tertiary eye center of patients with keratoconus and pellucid, with glaucoma or suspect glaucoma and age-matched keratoconus and pellucid controls, was performed. After informed consent was obtained, corneal topography, ocular response analyzer (ORA; Reicher, Buffalo, NY), pachymetry, intraocular pressure, A scan measurements, Humphrey visual fields (VFs), and disk photographs were done. Analyses compared cases with controls on primary (CH and CRF) and secondary variables. Disk photographs and VFs were rated in a masked fashion. The mean CH [8.2 (SD = 1.6) and 8.3 (SD = 1.5)] and CRF [7.3 (SD = 2.0) and 6.9 (SD = 2.1)] were low and did not differ significantly between 20 study (29 eyes) and 40 control patients (61 eyes), respectively. CH had a negative significant correlation with maximum corneal curvature by topography (P corneal thickness (P < 0.003). The mean cup to disk ratio was larger (0.54, SD = 0.20) among cases than in controls (0.38, SD = 0.20), P = 0.003. VFs were suspicious for glaucoma more often among the study eyes (11 of 29, 33.9%) than controls (8 of 60, 13.3%), P = 0.019. CH was low in study and control patients and was correlated with severity of keratoconus/pellucid but not with glaucoma/glaucoma suspect or control status. Evidence of glaucoma was more common in study eyes than in controls but was present in both.

  8. HTS Wire Development Workshop: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1994-07-01

    The 1994 High-Temperature Superconducting Wire Development Workshop was held on February 16--17 at the St. Petersburg Hilton and Towers in St. Petersburg, Florida. The meeting was hosted by Florida Power Corporation and sponsored by the US Department of Energy`s Superconductivity Program for Electric Power Systems. The meeting focused on recent high-temperature superconducting wire development activities in the Department of Energy`s Superconductivity Systems program. The meeting opened with a general discussion on the needs and benefits of superconductivity from a utility perspective, the US global competitiveness position, and an outlook on the overall prospects of wire development. The meeting then focused on four important technology areas: Wire characterization: issues and needs; technology for overcoming barriers: weak links and flux pinning; manufacturing issues for long wire lengths; and physical properties of HTS coils. Following in-depth presentations, working groups were formed in each technology area to discuss the most important current research and development issues. The working groups identified research areas that have the potential for greatly enhancing the wire development effort. These areas are discussed in the summary reports from each of the working groups. This document is a compilation of the workshop proceedings including all general session presentations and summary reports from the working groups.

  9. Quantifying the BICEP2-Planck tension over gravitational waves.

    Science.gov (United States)

    Smith, Kendrick M; Dvorkin, Cora; Boyle, Latham; Turok, Neil; Halpern, Mark; Hinshaw, Gary; Gold, Ben

    2014-07-18

    The recent BICEP2 measurement of B-mode polarization in the cosmic microwave background (r = 0.2(-0.05)(+0.07)), a possible indication of primordial gravity waves, appears to be in tension with the upper limit from WMAP (r < 0.13 at 95% C.L.) and Planck (r < 0.11 at 95% C.L.). We carefully quantify the level of tension and show that it is very significant (around 0.1% unlikely) when the observed deficit of large-scale temperature power is taken into account. We show that measurements of TE and EE power spectra in the near future will discriminate between the hypotheses that this tension is either a statistical fluke or a sign of new physics. We also discuss extensions of the standard cosmological model that relieve the tension and some novel ways to constrain them.

  10. Surface Tension and Fingering of Miscible Interfaces

    Science.gov (United States)

    Abib, Mohammed; Liu, Jian-Bang; Ronney, Paul D.

    1999-01-01

    Experiments on miscible, buoyantly unstable reaction-diffusion fronts and non-reacting displacement fronts in Hele-Shaw cells show a fingering-type instability whose wavelengths (lambda*) are consistent with an interfacial tension (sigma) at the front caused by the change in chemical composition, even though the solutions are miscible in all proportions. In conjunction with the Saffman-Taylor model, the relation sigma = K/tau, where tau is the interface thickness and K approximately equal 4 +/- 2 x 10(exp -6) dyne, enables prediction of our measured values of lambda* as well as results from prior experiments on miscible interfaces. These results indicate that even for miscible fluids, surface tension is generally a more significant factor than diffusion in interfacial stability and flow characteristics.

  11. 30 CFR 75.701-4 - Grounding wires; capacity of wires.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Grounding wires; capacity of wires. 75.701-4... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Grounding § 75.701-4 Grounding wires; capacity of wires. Where grounding wires are used to ground metallic sheaths, armors, conduits, frames...

  12. 1 mil gold bond wire study.

    Energy Technology Data Exchange (ETDEWEB)

    Huff, Johnathon; McLean, Michael B.; Jenkins, Mark W.; Rutherford, Brian Milne

    2013-05-01

    In microcircuit fabrication, the diameter and length of a bond wire have been shown to both affect the current versus fusing time ratio of a bond wire as well as the gap length of the fused wire. This study investigated the impact of current level on the time-to-open and gap length of 1 mil by 60 mil gold bond wires. During the experiments, constant current was provided for a control set of bond wires for 250ms, 410ms and until the wire fused; non-destructively pull-tested wires for 250ms; and notched wires. The key findings were that as the current increases, the gap length increases and 73% of the bond wires will fuse at 1.8A, and 100% of the wires fuse at 1.9A within 60ms. Due to the limited scope of experiments and limited data analyzed, further investigation is encouraged to confirm these observations.

  13. Assisted extraction of the energy level spacings and lever arms in direct current bias measurements of one-dimensional quantum wires, using an image recognition routine

    Energy Technology Data Exchange (ETDEWEB)

    Lesage, A. A. J., E-mail: arthur.lesage@cern.ch; Smith, L. W., E-mail: lsmith34@wisc.edu; Griffiths, J. P.; Farrer, I.; Jones, G. A. C.; Ritchie, D. A.; Smith, C. G. [Cavendish Laboratory, Department of Physics, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Al-Taie, H.; Kelly, M. J. [Cavendish Laboratory, Department of Physics, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Centre for Advanced Photonics and Electronics, Electrical Engineering Division, Department of Engineering, 9 J. J. Thomson Avenue, University of Cambridge, Cambridge CB3 0FA (United Kingdom); See, P. [National Physical Laboratory, Hampton Road, Teddington, Middlesex TW11 0LW (United Kingdom)

    2015-01-07

    A multiplexer technique is used to individually measure an array of 256 split gates on a single GaAs/AlGaAs heterostructure. This results in the generation of large volumes of data, which requires the development of automated data analysis routines. An algorithm is developed to find the spacing between discrete energy levels, which form due to transverse confinement from the split gate. The lever arm, which relates split gate voltage to energy, is also found from the measured data. This reduces the time spent on the analysis. Comparison with estimates obtained visually shows that the algorithm returns reliable results for subband spacing of split gates measured at 1.4 K. The routine is also used to assess direct current bias spectroscopy measurements at lower temperatures (50 mK). This technique is versatile and can be extended to other types of measurements. For example, it is used to extract the magnetic field at which Zeeman-split 1D subbands cross one another.

  14. Surface tension of Nanofluid-type fuels containing suspended nanomaterials.

    Science.gov (United States)

    Tanvir, Saad; Qiao, Li

    2012-04-18

    The surface tension of ethanol and n-decane based nanofluid fuels containing suspended aluminum (Al), aluminum oxide (Al2O3), and boron (B) nanoparticles as well as dispersible multi-wall carbon nanotubes (MWCNTs) were measured using the pendant drop method by solving the Young-Laplace equation. The effects of nanoparticle concentration, size and the presence of a dispersing agent (surfactant) on surface tension were determined. The results show that surface tension increases both with particle concentration (above a critical concentration) and particle size for all cases. This is because the Van der Waals force between particles at the liquid/gas interface increases surface free energy and thus increases surface tension. At low particle concentrations, however, addition of particles has little influence on surface tension because of the large distance between particles. An exception is when a surfactant was used or when (MWCNTs) was involved. For such cases, the surface tension decreases compared to the pure base fluid. The hypothesis is the polymer groups attached to (MWCNTs) and the surfactant layer between a particle and the surround fluid increases the electrostatic force between particles and thus reduce surface energy and surface tension.

  15. Surface tension of Nanofluid-type fuels containing suspended nanomaterials

    Science.gov (United States)

    2012-01-01

    The surface tension of ethanol and n-decane based nanofluid fuels containing suspended aluminum (Al), aluminum oxide (Al2O3), and boron (B) nanoparticles as well as dispersible multi-wall carbon nanotubes (MWCNTs) were measured using the pendant drop method by solving the Young-Laplace equation. The effects of nanoparticle concentration, size and the presence of a dispersing agent (surfactant) on surface tension were determined. The results show that surface tension increases both with particle concentration (above a critical concentration) and particle size for all cases. This is because the Van der Waals force between particles at the liquid/gas interface increases surface free energy and thus increases surface tension. At low particle concentrations, however, addition of particles has little influence on surface tension because of the large distance between particles. An exception is when a surfactant was used or when (MWCNTs) was involved. For such cases, the surface tension decreases compared to the pure base fluid. The hypothesis is the polymer groups attached to (MWCNTs) and the surfactant layer between a particle and the surround fluid increases the electrostatic force between particles and thus reduce surface energy and surface tension. PMID:22513039

  16. Method of Obtaining High Resolution Intrinsic Wire Boom Damping Parameters for Multi-Body Dynamics Simulations

    Science.gov (United States)

    Yew, Alvin G.; Chai, Dean J.; Olney, David J.

    2010-01-01

    The goal of NASA's Magnetospheric MultiScale (MMS) mission is to understand magnetic reconnection with sensor measurements from four spinning satellites flown in a tight tetrahedron formation. Four of the six electric field sensors on each satellite are located at the end of 60- meter wire booms to increase measurement sensitivity in the spin plane and to minimize motion coupling from perturbations on the main body. A propulsion burn however, might induce boom oscillations that could impact science measurements if oscillations do not damp to values on the order of 0.1 degree in a timely fashion. Large damping time constants could also adversely affect flight dynamics and attitude control performance. In this paper, we will discuss the implementation of a high resolution method for calculating the boom's intrinsic damping, which was used in multi-body dynamics simulations. In summary, experimental data was obtained with a scaled-down boom, which was suspended as a pendulum in vacuum. Optical techniques were designed to accurately measure the natural decay of angular position and subsequently, data processing algorithms resulted in excellent spatial and temporal resolutions. This method was repeated in a parametric study for various lengths, root tensions and vacuum levels. For all data sets, regression models for damping were applied, including: nonlinear viscous, frequency-independent hysteretic, coulomb and some combination of them. Our data analysis and dynamics models have shown that the intrinsic damping for the baseline boom is insufficient, thereby forcing project management to explore mitigation strategies.

  17. The effects of ambient impurities on the surface tension

    OpenAIRE

    Ponce-Torres A.; Vega E. J.

    2016-01-01

    A liquid bridge is a liquid column held captive between two coaxial and parallel solid disks. It is an excellent test bench where measuring the surface tension. In this paper, we used this fluid configuration to examine experimentally the effects of ambient impurities on the surface tension over time. For this purpose, the liquid bridge equilibrium shape was analyzed when the liquid bridge was surrounded by three environments: the uncontrolled ambient, and both air and argon encapsulated in a...

  18. Molecular wires, switches and memories

    Science.gov (United States)

    Chen, Jia

    Molecular electronics, an emerging field, makes it possible to build individual molecules capable of performing functions identical or analogous to present- day conductors, switches, or memories. These individual molecules, with a nano-meter scale characteristic length, can be designed and chemically synthesized with specific atoms, geometries and charge distribution. This thesis focuses on the design, and measurements of molecular wires, and related strategically engineered structures-molecular switches and memories. The experimental system relies on a thermodynamically driven self-assembling process to attach molecules onto substrate surfaces without intervention from outside. The following topics will be discussed: directed nanoscale manipulation of self-assembled molecules using scanning tunneling microscope; investigation on through-bond transport of nanoscale symmetric metal/conjugated self- assembled monolayers (SAM)/metal junctions, where non- Ohmic thermionic emission was observed to be the dominant process, with isocyanide-Pd contacts showing the lowest thermionic barrier of 0.22 eV; the first realization of robust and large reversible switching behavior in an electronic device that utilizes molecules containing redox centers as the active component, exhibiting negative differential resistance (NDR) and large on-off peak-to-valley ratio (PVR); observation of erasable storage of higher conductivity states in these redox- center containing molecular devices, and demonstration of a two-terminal electronically programmable and erasable molecular memory cell with long bit retention time.

  19. Mapping surface tension induced menisci with application to tensiometry and refractometry.

    Science.gov (United States)

    Mishra, Avanish; Kulkarni, Varun; Khor, Jian-Wei; Wereley, Steve

    2015-07-28

    In this work, we discuss an optical method for measuring surface tension induced menisci. The principle of measurement is based upon the change in the background pattern produced by the curvature of the meniscus acting as a lens. We measure the meniscus profile over an inclined glass plate and utilize the measured meniscus for estimation of surface tension and refractive index.

  20. Length Tension Function of Puborectalis Muscle: Implications for the Treatment of Fecal Incontinence and Pelvic Floor Disorders

    Science.gov (United States)

    Mittal, Ravinder K; Sheean, Geoff; Padda, Bikram S; Rajasekaran, Mahadevan R

    2014-01-01

    Background/Aims External anal sphincter (EAS) and puborectalis muscle (PRM) play important role in anal continence function. Based on length-tension measurement, we recently reported that the human EAS muscle operates at short sarcomere length under physiological conditions. Goal of our study was to determine if PRM also operates at the short sarcomere length. Methods Length-tension relationship of the PRM muscle was studied in vivo in 10 healthy nullipara women. Length was altered by vaginal distension using custom-designed probes of 5, 10, 15, 20, 25 and 30 mm diameters as well as by distending a polyethylene bag with different volumes of water. Probes were equipped with a reverse perfuse sleeve sensor to measure vaginal pressure (surrogate of PRM tension). PRM electromyogram (EMG) was recorded using wire electrodes. Three-dimensional ultra-sound images were obtained to determine effect of vaginal distension on PRM length. Results Ultrasound images demonstrate distension volume dependent increase in PRM length. Rest and squeeze pressures of vaginal bag increased with the increase in bag volume. Similarly, the change in vaginal pressure, which represents the PRM contraction increased with the increase in the probe size. Increase in probe size was not associated with an increase in EMG activity (a marker of neural drive) of the PRM. Conclusions Probe size dependent increase in PRM contraction pressure, in the presence of constant EMG (neural input) proves that the human PRM operates at short sarcomere length. Surgically adjusting the PRM length may represent a novel strategy to improve treat anal continence and possibly other pelvic floor disorders. PMID:25273124

  1. Correlated atomic wires on substrates. II. Application to Hubbard wires

    Science.gov (United States)

    Abdelwahab, Anas; Jeckelmann, Eric; Hohenadler, Martin

    2017-07-01

    In the first part of our theoretical study of correlated atomic wires on substrates, we introduced lattice models for a one-dimensional quantum wire on a three-dimensional substrate and their approximation by quasi-one-dimensional effective ladder models [Abdelwahab et al., preceding paper, Phys. Rev. B 96, 035445 (2017), 10.1103/PhysRevB.96.035445]. In this second part, we apply this approach to the case of a correlated wire with a Hubbard-type electron-electron repulsion deposited on an insulating substrate. The ground-state and spectral properties are investigated numerically using the density-matrix renormalization group method and quantum Monte Carlo simulations. As a function of the model parameters, we observe various phases with quasi-one-dimensional low-energy excitations localized in the wire, namely, paramagnetic Mott insulators, Luttinger liquids, and spin-1 /2 Heisenberg chains. The validity of the effective ladder models is assessed for selected parameters by studying the dependence of results on the number of legs and comparing to the full three-dimensional model. We find that narrow ladder models accurately reproduce the quasi-one-dimensional excitations of the full three-dimensional model but predict only qualitatively whether excitations are localized around the wire or delocalized in the three-dimensional substrate.

  2. Study of high-pressure hydrogen-operated wire chambers designed for a precision measurement of the singlet mu p capture rate

    CERN Document Server

    Maev, E M; Case, T A; Crowe, K M; Dick, P U; Dijksman, A; Egger, J; Fetisov, A A; Ganzha, V A; Herold, W D; Hartmann, F J; Kammel, P; Krivchitch, A G; Maev, O E; Petitjean, C; Petrov, G E; Prieels, R; Sadetsky, S M; Schapkin, G N; Schmidt, R; Semenchuk, G G; Soroka, M; Vorobyov, A A; Voropaev, N I

    2002-01-01

    This work was carried out as part of a project aiming at a greatly improved measurement of the muon capture rate from the singlet state of the mu p atom. The experiment will be performed at the intense muon beam of PSI using a new experimental method allowing high precision measurements of the lifetime of muons stopped in ultra-pure deuterium-depleted hydrogen (protium). The basic element of the detector is a time projection chamber operating in hydrogen gas at 10 bar pressure. The arrival times and trajectories of the incoming muons and the outgoing decay electrons are measured with this device providing effective suppression of background. The system of chambers and electronics is designed for the large muon stop rates required for attaining high statistical accuracy. During four beam periods at PSI, data were taken. Also, various studies of the MWPC performance in hydrogen were made including ageing studies of the chambers under irradiation with stopped muons and with alpha and beta sources. It was demonst...

  3. "Train surfers": analysis of 23 cases of electrical burns caused by high tension railway overhead cables.

    Science.gov (United States)

    Sternick, I; Gomes, R D; Serra, M C; Radwanski, H N; Pitanguy, I

    2000-08-01

    The term "train surfers" describes a group of adolescents from the outskirts of the city of Rio de Janeiro, who are compelled by the overcrowded railway trains to travel on the roofs of the wagons. Collision with electrical high-tension wires is a relatively frequent occurrence, causing extensive and complex injuries. This study analyzes this clinical and surgical phenomenon which has caused over 100 fatalities in more than 200 registered accidents over the past 10 years.

  4. The anchors of steel wire ropes, testing methods and their results

    Directory of Open Access Journals (Sweden)

    J. Krešák

    2012-10-01

    Full Text Available The present paper introduces an application of the acoustic and thermographic method in the defectoscopic testing of immobile steel wire ropes at the most critical point, the anchor. First measurements and their results by these new defectoscopic methods are shown. In defectoscopic tests at the anchor, the widely used magnetic method gives unreliable results, and therefore presents a problem for steel wire defectoscopy. Application of the two new methods in the steel wire defectoscopy at the anchor point will enable increased safety measures at the anchor of steel wire ropes in bridge, roof, tower and aerial cable lift constructions.

  5. Aging analyses of aircraft wire insulation

    Energy Technology Data Exchange (ETDEWEB)

    GILLEN,KENNETH T.; CLOUGH,ROGER LEE; CELINA,MATHIAS C.; AUBERT,JAMES H.; MALONE,G. MICHAEL

    2000-05-08

    investigation of aircraft wiring is to evaluate the applicability of their various techniques to aircraft cables, after which they expect to identify a limited subset of techniques which are appropriate for each of the major aircraft wiring types. The techniques of initial interest in the studies of aging aircraft wire are as follows: optical microscopy; mandrel bend test; tensile test/elongation at break; density measurements; modulus profiling/(spatially-resolved micro-hardness); oxygen induction time/oxygen induction temperature (by differential scanning calorimetry); solvent-swelling/gel fraction; infrared spectroscopy (with chemical derivatization as warranted); chemiluminescence; thermo-oxidative wear-out assessment; The first two techniques are the simplest and quickest to apply; those further down the list tend to be more information rich and in some cases more sensitive, but also generally more specialized and more time consuming to run. Accordingly, the procedure will be to apply the simplest tests for purposes of preliminary screening of large numbers of samples. For any given material type, it can be expected that only a limited number of the other techniques will prove to be useful, and therefore, the more specialized techniques will be used on a limited number of selected samples. Samples of aircraft wiring have begun to be released to the authors in late April; they include in this report some limited and preliminary data on these materials.

  6. Laser Indirect Shock Welding of Fine Wire to Metal Sheet

    Science.gov (United States)

    Wang, Xiao; Huang, Tao; Luo, Yapeng; Liu, Huixia

    2017-01-01

    The purpose of this paper is to present an advanced method for welding fine wire to metal sheet, namely laser indirect shock welding (LISW). This process uses silica gel as driver sheet to accelerate the metal sheet toward the wire to obtain metallurgical bonding. A series of experiments were implemented to validate the welding ability of Al sheet/Cu wire and Al sheet/Ag wire. It was found that the use of a driver sheet can maintain high surface quality of the metal sheet. With the increase of laser pulse energy, the bonding area of the sheet/wire increased and the welding interfaces were nearly flat. Energy dispersive spectroscopy (EDS) results show that the intermetallic phases were absent and a short element diffusion layer which would limit the formation of the intermetallic phases emerging at the welding interface. A tensile shear test was used to measure the mechanical strength of the welding joints. The influence of laser pulse energy on the tensile failure modes was investigated, and two failure modes, including interfacial failure and failure through the wire, were observed. The nanoindentation test results indicate that as the distance to the welding interface decreased, the microhardness increased due to the plastic deformation becoming more violent. PMID:28895900

  7. Forces generated in guide-wires when drilling human bone.

    Science.gov (United States)

    Shuaib, I; Hillery, M

    1995-01-01

    In orthopaedic surgery guide-wires are extensively used for the drilling of pilot holes in human bones to allow further drilling, reaming and screw-tapping to take place in the repair and reconstruction of fractures. The guide-wires are generally 1.5 to 2.5 mm in diameter and have a three-faceted point with or without a screw thread. This paper describes drilling tests carried out using both types of guide-wire and these are compared with results obtained from a two-faceted geometry developed during this research. Tests were performed on the heads of femurs which had been removed during hip arthroplasty. A variable speed drilling machine together with a very sensitive drilling dynamometer were used for measuring the torque and thrust during the experimental stage of the research. This equipment was developed as part of an overall research programme into the mechanics of drilling of human bone. The indications are, firstly, that little advantage is gained by using a threaded-point guide-wire. In fact using a thread on the guide-wire can be a disadvantage. Secondly, the thrust cutting force is dependent on the spindle speed and feed. An optimum set of speeds of between 800 and 1400 r/min is recommended for 2.5 mm diameter guide-wires.

  8. Historical Tensions in Engineering Education

    DEFF Research Database (Denmark)

    Jamison, Andrew; Heymann, Matthias

    2012-01-01

    Ever since institutions for educating engineers first began to be ­established in Europe, there have been a number of fundamental tensions as to how that ­educating should best be conducted, what it should consist of, and who should do the educating. These tensions are based on different styles...... or approaches to ­engineering education that have developed historically in different parts of Europe and which have led to what we characterize as “theory-driven,” “practice-driven,” and “technology-driven” approaches. This chapter explores some of the historical roots of these tensions in medieval Europe...... and briefly traces their developmental trajectories through the subsequent formation of institutions of engineering ­education. It has been written as part of PROCEED (Program of Research on Opportunities and Challenges in Engineering Education in Denmark)....

  9. The effects of ambient impurities on the surface tension

    Directory of Open Access Journals (Sweden)

    Ponce-Torres A.

    2016-01-01

    Full Text Available A liquid bridge is a liquid column held captive between two coaxial and parallel solid disks. It is an excellent test bench where measuring the surface tension. In this paper, we used this fluid configuration to examine experimentally the effects of ambient impurities on the surface tension over time. For this purpose, the liquid bridge equilibrium shape was analyzed when the liquid bridge was surrounded by three environments: the uncontrolled ambient, and both air and argon encapsulated in a small glass cover. Ambient contamination produced a sharp decrease of the surface tension of ultra-pure water. The presence of an anionic surfactant in the free surface of an aqueous solution did not inhibit the action of impurities coming from the ambient. Impurities can influence the dynamical behavior of the free surface in flows dominated by the surface tension. Therefore, a careful control of that influence can be crucial in many applications of fluid mechanics.

  10. Plasma arc torch with coaxial wire feed

    Science.gov (United States)

    Hooper, Frederick M

    2002-01-01

    A plasma arc welding apparatus having a coaxial wire feed. The apparatus includes a plasma arc welding torch, a wire guide disposed coaxially inside of the plasma arc welding torch, and a hollow non-consumable electrode. The coaxial wire guide feeds non-electrified filler wire through the tip of the hollow non-consumable electrode during plasma arc welding. Non-electrified filler wires as small as 0.010 inches can be used. This invention allows precision control of the positioning and feeding of the filler wire during plasma arc welding. Since the non-electrified filler wire is fed coaxially through the center of the plasma arc torch's electrode and nozzle, the wire is automatically aimed at the optimum point in the weld zone. Therefore, there is no need for additional equipment to position and feed the filler wire from the side before or during welding.

  11. Ocular dangers of fencing wire.

    Science.gov (United States)

    McAllum, P; Barnes, R; Dickson, J

    2001-07-27

    To invesitgate the incidence and severity of penetrating eye injuries caused by fencing wire in the Waikato region. We reviewed the case notes for all penetrating eye injuries treated at Waikato Hospital during the past six years. Parameters recorded were patient age and sex, mechanism of injury, initial visual acuity, characteristics of injury, surgery performed and final visual outcome. The incidence of penetrating eye injuries in the Waikato region was 3.8 per 100,000 per year, based on an estimated catchment population of 350,000. We found fencing wire to be the third most common cause of penetrating eye injury, accounting for 8.8% of injuries, behind motor vehicle accidents and hammering which accounted for 26.3% and 20.0% of injuries, respectively. The fencing wire injuries involved men exclusively, with an average age of 41.7 years. Fencing wire injuries had worse presenting visual acuity than other injuries, involved the posterior segment of the eye more frequently and were more likely to develop bacterial endophthalmitis. They also underwent more surgical procedures and were more commonly associated with a poor visual outcome. Fencing wire is an important cause of visual loss in the Waikato region. We hope to raise awareness of its potential ocular dangers and to promote the use of appropriate eye protection.

  12. Effect of a dielectric coating on terahertz surface plasmon polaritons on metal wires

    NARCIS (Netherlands)

    Van der Valk, N.C.J.; Planken, P.C.M.

    2005-01-01

    The authors present measurements and calculations on the effect of thin dielectric coatings on the propagation of terahertz pulses along the surface of metal wires. Our measurements show that propagation over only a few centimeters of wire having a thin dielectric coating, strongly distorts the

  13. Hot-wire calibration in subsonic/transonic flow regimes

    Science.gov (United States)

    Nagabushana, K. A.; Ash, Robert L.

    1995-01-01

    A different approach for calibrating hot-wires, which simplifies the calibration procedure and reduces the tunnel run-time by an order of magnitude was sought. In general, it is accepted that the directly measurable quantities in any flow are velocity, density, and total temperature. Very few facilities have the capability of varying the total temperature over an adequate range. However, if the overheat temperature parameter, a(sub w), is used to calibrate the hot-wire then the directly measurable quantity, voltage, will be a function of the flow variables and the overheat parameter i.e., E = f(u,p,a(sub w), T(sub w)) where a(sub w) will contain the needed total temperature information. In this report, various methods of evaluating sensitivities with different dependent and independent variables to calibrate a 3-Wire hot-wire probe using a constant temperature anemometer (CTA) in subsonic/transonic flow regimes is presented. The advantage of using a(sub w) as the independent variable instead of total temperature, t(sub o), or overheat temperature parameter, tau, is that while running a calibration test it is not necessary to know the recovery factor, the coefficients in a wire resistance to temperature relationship for a given probe. It was deduced that the method employing the relationship E = f (u,p,a(sub w)) should result in the most accurate calibration of hot wire probes. Any other method would require additional measurements. Also this method will allow calibration and determination of accurate temperature fluctuation information even in atmospheric wind tunnels where there is no ability to obtain any temperature sensitivity information at present. This technique greatly simplifies the calibration process for hot-wires, provides the required calibration information needed in obtaining temperature fluctuations, and reduces both the tunnel run-time and the test matrix required to calibrate hotwires. Some of the results using the above techniques are presented

  14. Experimental techniques for characterizing the thermo-electro-mechanical shakedown response of SMA wires and tubes

    Science.gov (United States)

    Churchill, Christopher B.

    Shape Memory Alloys (SMAs) are a unique and valuable group of active materials. NiTi, the most popular SMA, has a power density orders of magnitude greater than any other known material, making it valuable in the medical and transportation industries where weight and space are at a premium. In the nearly half-century since its discovery, the adoption of NiTi has been slowed primarily by the engineering difficulties associated with its use: strong thermal coupling, material level instabilities, and rapid shakedown of material properties during cycling. Material properties change drastically with minute changes in alloy composition, so it is common to require a variety of experiments to fully characterize a new SMA material, all of which must be performed and interpreted with specialized techniques. This thesis collects many of these techniques into a series of characterization experiments, documenting several new phenomena in the process. First, three different alloys of NiTi wire are characterized through differential scanning calorimetry, isothermal tension, and constant load thermal cycling experiments. New techniques are presented for ER measurement and temperature control of SMA wires and temperature measurement of SMA tubes. It is shown that the shakedown of material properties with thermal cycling is not only dependent on the applied load and number of cycles, but has a large association with the direction of phase transformation. Several of these techniques are then applied to a systematic characterization of NiTi tubes in tension, compression, and bending. Particular attention is given to the nucleation and propagation of transformation fronts in tensile specimens. Compression experiments show dramatic asymmetry in the uniaxial response, with compression characterized by a lower transformation strain, higher transformation stress, and uniform transformations (no fronts). A very simple SMA actuator model is introduced. After identifying the relevant non

  15. Surface Tension of Ab Initio Liquid Water at the Water-Air Interface

    CERN Document Server

    Nagata, Yuki; Bonn, Mischa; Kühne, Thomas D

    2016-01-01

    We report calculations of the surface tension of the water-air interface using ab initio molecular dynamics (AIMD) simulations. We investigate the simulation cell size dependence of the surface tension of water from force field molecular dynamics (MD) simulations, which show that the calculated surface tension increases with increasing simulation cell size, thereby illustrating that a correction for finite size effects is required for the small system used in the AIMD simulation. The AIMD simulations reveal that the double-{\\xi} basis set overestimates the experimentally measured surface tension due to the Pulay stress, while the triple and quadruple-{\\xi} basis sets give similar results. We further demonstrate that the van der Waals corrections critically affect the surface tension. AIMD simulations without the van der Waals correction substantially underestimate the surface tension, while van der Waals correction with the Grimme's D2 technique results in the value for the surface tension that is too high. T...

  16. Weyl fermions in cylindrical wires

    Science.gov (United States)

    Erementchouk, Mikhail; Mazumder, Pinaki

    2018-01-01

    The key feature of Weyl semimetals (WSMs) is the presence of topologically protected Dirac cones in a three-dimensional material. We consider the effect of restricting geometry on the spectrum of excitations in WSMs using as a model a cylindrical WSM wire. For the full manifold of hard boundary conditions, we derive the general form of the dispersion equation relating the energy of the excitations and their momentum along the wire. We show that only the special class of boundary conditions, corresponding to decoupled helicities or, equivalently, to pinned directions of the electron spin on the surface, support massless excitations. For a general boundary condition, these excitations acquire mass inversely proportional to the radius of the wire. This demonstrates that boundary phenomena may play a crucial role in formation of excitations in WSM based structures.

  17. Surface Tension Directed Fluidic Self-Assembly of Semiconductor Chips across Length Scales and Material Boundaries

    Directory of Open Access Journals (Sweden)

    Shantonu Biswas

    2016-03-01

    Full Text Available This publication provides an overview and discusses some challenges of surface tension directed fluidic self-assembly of semiconductor chips which are transported in a liquid medium. The discussion is limited to surface tension directed self-assembly where the capture, alignment, and electrical connection process is driven by the surface free energy of molten solder bumps where the authors have made a contribution. The general context is to develop a massively parallel and scalable assembly process to overcome some of the limitations of current robotic pick and place and serial wire bonding concepts. The following parts will be discussed: (2 Single-step assembly of LED arrays containing a repetition of a single component type; (3 Multi-step assembly of more than one component type adding a sequence and geometrical shape confinement to the basic concept to build more complex structures; demonstrators contain (3.1 self-packaging surface mount devices, and (3.2 multi-chip assemblies with unique angular orientation. Subsequently, measures are discussed (4 to enable the assembly of microscopic chips (10 μm–1 mm; a different transport method is introduced; demonstrators include the assembly of photovoltaic modules containing microscopic silicon tiles. Finally, (5 the extension to enable large area assembly is presented; a first reel-to-reel assembly machine is realized; the machine is applied to the field of solid state lighting and the emerging field of stretchable electronics which requires the assembly and electrical connection of semiconductor devices over exceedingly large area substrates.

  18. Surface tension of ab initio liquid water at the water-air interface.

    Science.gov (United States)

    Nagata, Yuki; Ohto, Tatsuhiko; Bonn, Mischa; Kühne, Thomas D

    2016-05-28

    We report calculations on the surface tension of the water-air interface using ab initio molecular dynamics (AIMD) simulations. We investigate the influence of the cell size on surface tension of water from force field molecular dynamics simulations. We find that the calculated surface tension increases with increasing simulation cell size, thereby illustrating that a correction for finite size effects is essential for small systems that are customary in AIMD simulations. Moreover, AIMD simulations reveal that the use of a double-ζ basis set overestimates the experimentally measured surface tension due to the Pulay stress while more accurate triple and quadruple-ζ basis sets give converged results. We further demonstrate that van der Waals corrections critically affect the surface tension. AIMD simulations without the van der Waals correction substantially underestimate the surface tension while the van der Waals correction with the Grimme's D2 technique results in a value for the surface tension that is too high. The Grimme's D3 van der Waals correction provides a surface tension close to the experimental value. Whereas the specific choices for the van der Waals correction and basis sets critically affect the calculated surface tension, the surface tension is remarkably insensitive to the details of the exchange and correlation functionals, which highlights the impact of long-range interactions on the surface tension. Our simulated values provide important benchmarks, both for improving van der Waals corrections and AIMD simulations of aqueous interfaces.

  19. Tension type headaches: a review

    African Journals Online (AJOL)

    Acetaminophen (paracetamol) 500-1 000 mg and aspirin 500-. 1 000 mg, have been demonstrated to be an effective first-line treatment for episodic tension-type headaches in most placebo- controlled trials. 23,24 Fast absorptive formulations of the latter are preferred for rapidity of action.25 It is worth noting that these.

  20. Abolishing the maximum tension principle

    Directory of Open Access Journals (Sweden)

    Mariusz P. Da̧browski

    2015-09-01

    Full Text Available We find the series of example theories for which the relativistic limit of maximum tension Fmax=c4/4G represented by the entropic force can be abolished. Among them the varying constants theories, some generalized entropy models applied both for cosmological and black hole horizons as well as some generalized uncertainty principle models.

  1. Headache (chronic tension-type).

    Science.gov (United States)

    Krishnan, Anita; Silver, Nicholas

    2009-07-22

    Chronic tension-type headache (CTTH) is a disorder that evolves from episodic tension-type headache, with daily or very frequent episodes of headache lasting minutes to days. It affects 4.1% of the general population in the USA, and is more prevalent in women (up to 65% of cases). We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of drug treatments for chronic tension-type headache? What are the effects of non-drug treatments for chronic tension-type headache? We searched: Medline, Embase, The Cochrane Library, and other important databases up to March 2007 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). We found 50 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. In this systematic review, we present information relating to the effectiveness and safety of the following interventions: acupuncture; amitriptyline; analgesics; anticonvulsant drugs; benzodiazepines; botulinum toxin; chiropractic and osteopathic manipulations; cognitive behavioural therapy (CBT); Indian head massage; mirtazapine; relaxation and electromyographic biofeedback; selective serotonin reuptake inhibitor antidepressants (SSRIs); and tricyclic antidepressants (other than amitriptyline).

  2. CALCULATION OF TENSION FORCE OF BELT CONVEYOR

    OpenAIRE

    Ismet Ibishi; Ahmet Latifi; Gzim Ibishi; Kadri Sejdiu; Melihate Shala-Galica; Bekim Latifi

    2012-01-01

    In this paper is done the explanation on tension fashion of the belt conveyor which is employed in Kosovo Energy Corporation – KEK, for coal transportation to provide electric power plant. The aim of the paper enables to recognize tension forces not to pass with deformation of belt so that this problem will damage the workingprocess. Work principle is based on initial tension and tension during working process. The fact is known that the tension starts from the carriage on the way to tension ...

  3. AC loss properties of MgB{sub 2} multifilament wires

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Kazuhide; Funaki, Kazuo; Sueyoshi, Takahiro; Sasashige, Yushi; Kajikawa, Kazuhiro; Iwakuma, Masataka [Kyushu University Graduate School of Information Science and Electrical Engineering, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395 (Japan); Okada, Michiya [HRL Hitachi, Ltd, 7-1-1 Oomika, Hitachi 319-1292 (Japan); Kumakura, Hiroaki [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047 (Japan); Hayashi, Hidemi [Kyushu Electric Power Co., Incorporated, 2-1-47 Shiobaru, Minami-ku, Fukuoka 815-8520 (Japan)], E-mail: kazuhide.tanaka.je@hitachi.com

    2008-09-15

    We designed and fabricated two types of composite wires with 6 MgB{sub 2} filaments. One is a Cu-sheathed Nb-barrier wire and the other is a CuNi-sheathed Ta-barrier wire. The transverse-field losses of the trial wires were measured with a standardized pickup coil system in liquid helium. We evaluated the observed AC losses using two structural models, a multifilament conductor model and a hollow-cylindrical one. For the CuNi-sheathed Ta-barrier wire, the AC loss property can be explained by the usual model of multifilament conductors. Further reductions in AC loss can be expected by making the filaments thinner. For the Cu-sheathed Nb-barrier wire, theoretical considerations suggest the multifilament structure behaves as a hollow-cylindrical superconductor in the AC loss property. Thus, we need to pay particular attention to designing the barrier material for reduction in the AC loss.

  4. The contact conductance on a molecular wire

    Science.gov (United States)

    Stojkovic, S.; Joachim, C.; Grill, L.; Moresco, F.

    2005-06-01

    On a metal-molecule-metal nanojunction, the scanning tunneling microscope (STM) scans at the precise location of the electronic metal-molecule interaction permit a measurement of the contact conductance G0. The conversion curve between the change in the STM contrast Δ h due to this interaction and G0 is presented for a series of conjugated molecular wires. At chemisorption distances, the two-valued character of the G0(Δ h) function is discussed, indicating experimental ways to evaluate G0 as a function of Δ h for different metal-molecule interaction ranges.

  5. Interaction and Dephasing of Excitons in ZnSe Quantum Wires

    DEFF Research Database (Denmark)

    Wagner, Hans Peter; Langbein, Wolfgang; Hvam, Jørn Märcher

    1999-01-01

    We study the coherent formation of biexcitons in wet-etched ZnSe quantum wires of lateral sizes down to 23 nm by transient degenerate four-wave mixing. We observe an increase of the biexciton binding energy with decreasing wire width reaching 30% energy enhancement in the smallest wire structure...... compared to the mesa structure which is attributed to a quenching of the exciton-exciton scattering efficiency by density dependent measurements. The exciton dephasing is found to increase with decreasing wire width which is assigned to an enhanced repulsive exchange interaction between excitons of equal...

  6. Small-Bolt Torque-Tension Tester

    Science.gov (United States)

    Posey, Alan J.

    2009-01-01

    The device described here measures the torque-tension relationship for fasteners as small as #0. The small-bolt tester consists of a plate of high-strength steel into which three miniature load cells are recessed. The depth of the recess is sized so that the three load cells can be shimmed, the optimum height depending upon the test hardware. The three miniature load cells are arranged in an equilateral triangular configuration with the test bolt aligned with the centroid of the three. This is a kinematic arrangement.

  7. Subchannel Analysis of Wire Wrapped SCWR Assembly

    National Research Council Canada - National Science Library

    Shan, Jianqiang; Wang, Henan; Liu, Wei; Song, Linxing; Chen, Xuanxiang; Jiang, Yang

    2014-01-01

    .... The HPLWR wire wrapped assembly was analyzed. The results show that: (1) the assembly with wire wrap can obtain a more uniform coolant temperature profile than the grid spaced assembly, which will result in a lower peak cladding temperature; (2...

  8. Comparison of transverse wires and half pins in Taylor Spatial Frame: a biomechanical study.

    Science.gov (United States)

    Khurana, Ashish; Byrne, Carlton; Evans, Sam; Tanaka, Hiro; Haraharan, Kartik

    2010-03-27

    The aim of this study was to compare the stiffness characteristics of Taylor Spatial Frame (TSF) fixed with transverse wires and half pins. Experiments were carried out at the biomechanics laboratory at Cardiff University. All mechanical testing was performed with a servo hydraulic test frame (MTS 858 Mini Bionix II(R), MTS Corp., Mineapolis, USA). Custom built mounts were used to attach the bone rigidly to the one end of machine and the TSF ring to the other. Rings were fixed with 1.8 mm transverse wires or hydroxy-apatite coated 6.5 mm half pins in 45 degrees, 60 degrees, 75 degrees and 90 degrees divergence angles. Bone was loaded with axial load to 400 N and torque to 20 Nm in an indestructible manner. Load/displacement curve data were analyzed for slope and axial and angular displacements. For larger diameter rings (180 mm), for axial stiffness there was no statistically significant difference between the transverse wires (4 wires with 2 rings) and the half pins (2 pins with 1 ring) (p > 0.05). For 155 mm internal diameter rings, half pins provided statistically higher axial stiffness than transverse wires (p = 0.036). The half pins show significantly more torsion stiffness in both ring diameters (p < 0.05) in comparison to transverse wires. As in axial stiffness, small diameter rings show increased stiffness in torsion. There is increase in axial and torsion stiffness with the increase in the divergence angle between the wires or pins (p < 0.05). Half pins provide greater stiffness to TSF frames and allow for axial micro motion as well. This work provides a rationale for clinical decision making about the use of tensioned transverse wires in comparison to half pins in construction of a TSF frame.

  9. Core vs. Bulk Samples in Soil-Moisture Tension Analyses

    Science.gov (United States)

    Walter M. Broadfoot

    1954-01-01

    The usual laboratory procedure in determining soil-moisture tension values is to use "undisturbed" soil cores for tensions up to 60 cm. of water and bulk soil samples for higher tensions. Low tensions are usually obtained with a tension table and the higher tensions by use of pressure plate apparatus. In tension analysis at the Vicksburg Infiltration Project...

  10. Shape of a clamped stiff harpsichord wire driven at a resonant frequency

    Science.gov (United States)

    Hanson, Roger J.; Macomber, Hilliard Kent; Boucher, Mathew A.

    2002-05-01

    A wire transversely driven by a sinusoidal force at the resonant frequency of a vibrational mode vibrates at the driving frequency and at harmonics generated by nonlinear processes in the wire. If the amplitude of a harmonic is measured as a function of position along the wire, its shape is revealed. It differs significantly from a sinusoid in the vicinity of either end of the wire because the ends are clamped and the wire has significant stiffness. The shapes of various harmonics have been determined for a brass harpsichord wire, 70 cm long, from optical detector measurements made at different distances from a clamped end. Knowledge of shape facilitates the determination of antinode amplitudes of harmonics when the gross motion of the wire is so large that the detectors must be positioned near an end of the wire because of their very limited dynamic range. Some observations of harmonics and related phenomena were reported previously [Hanson et al., J. Acoust Soc. Am. 108, 2592 (2000); 106, 2141 (1999)]. The shape information is also needed to help separate nonlinear effects possibly occurring in the detectors from those of interest, occurring in the wire itself.

  11. Z-Pinch Wire-Electrode Contact Resistance Studies Using Weighted and Soft Metal Gasket Contacts*

    Science.gov (United States)

    Gomez, M. R.; Zier, J. C.; Thurtell, A. F.; French, D. M.; Gilgenbach, R. M.; Tang, W.; Lau, Y. Y.

    2008-11-01

    The contact made between z-pinch wires and electrodes has a significant effect on both the energy deposited in the wires and the uniformity of the expansion profile of the wires. We have shown that using soft metal gaskets can improve wire-electrode contact significantly over typical weighted contacts. Images of wire expansion profile and wire plasma emission will be presented for single and double wire shots on a 16 kA, 100 kV 4-stage Marx bank with 150 ns risetime. Bench resistance measurements for aluminum, stainless steel, and tungsten wires with diameters ranging from 7.5 um to 30 um will be presented. These measurements utilized both soft metal gasket contacts (gaskets include: indium, silver, aluminum, tin, and lead) and double-ended wire weight contacts (weights ranged from 0.4 g to 1.9 g). *This research was supported by U. S. DoE through Sandia National Laboratories award document numbers 240985, 768225, 790791 and 805234 to the University of Michigan. MRG supported by NNSA Fellowship and JCZ supported by NPSC Fellowship sponsored by Sandia National Labs.

  12. Introduction of CORC® wires: highly flexible, round high-temperature superconducting wires for magnet and power transmission applications

    Science.gov (United States)

    Weiss, Jeremy D.; Mulder, Tim; ten Kate, Herman J.; van der Laan, Danko C.

    2017-01-01

    Conductor on Round Core (CORC®) technology has achieved a long sought-after benchmark by enabling the production of round, multifilament, (RE)Ba2Ca3O7-x coated conductors with practical current densities for use in magnets and power applications. Recent progress, including the demonstration of engineering current density beyond 300 Amm-2 at 4.2 K and 20 T, indicates that CORC® cables are a viable conductor for next generation high field magnets. Tapes with 30 μm substrate thickness and tape widths down to 2 mm have improved the capabilities of CORC® technology by allowing the production of CORC® wires as thin as 3 mm in diameter with the potential to enhance the engineering current density further. An important benefit of the thin CORC® wires is their improved flexibility compared to thicker (7-8 mm diameter) CORC® cables. Critical current measurements were carried out on tapes extracted from CORC® wires made using 2 and 3 mm wide tape after bending the wires to various diameters from 10 to 3.5 cm. These thin wires are highly flexible and retain close to 90% of their original critical current even after bending to a diameter of 3.5 cm. A small 5-turn solenoid was constructed and measured as a function of applied magnetic field, exhibiting an engineering current density of 233 Amm-2 at 4.2 K and 10 T. CORC® wires thus form an attractive solution for applications between 4.2 and 77 K, including high-field magnets that require high current densities with small bending diameters, benefiting from a ready-to-use form (similar to NbTi and contrary to Nb3Sn wires) that does not require additional processing following coil construction.

  13. Joining characteristics of orthodontic wires with laser welding.

    Science.gov (United States)

    Iijima, Masahiro; Brantley, William A; Yuasa, Toshihiro; Muguruma, Takeshi; Kawashima, Isao; Mizoguchi, Itaru

    2008-01-01

    Laser welding 0.016 x 0.022 in. beta-Ti, Ni-Ti, and Co-Cr-Ni orthodontic wires was investigated by measuring joint tensile strength, measuring laser penetration depth, determining metallurgical phases using micro X-ray diffraction (micro-XRD), and examining microstructures with an scanning electron microscope (SEM). Welding was performed from 150 to 230 V. Mean tensile strength for Ni-Ti groups was significantly lower (p Ni was significantly lower than for control specimens joined by silver soldering, it was sufficient for clinical use. The beta-Ti orthodontic wire showed deeper penetration depth from laser welding than the Ni-Ti and Co-Cr-Ni orthodontic wires. Micro-XRD patterns of laser-welded beta-Ti and Ni-Ti obtained 2 mm from the boundary were similar to as-received specimens, indicating that original microstructures were maintained. When output voltages of 190 V and higher were used, most peaks from joint areas disappeared or were much weaker, perhaps because of a directional solidification effect, evidenced by SEM observation of fine striations in welded beta-Ti. Laser welding beta-Ti and Co-Cr-Ni wires may be acceptable clinically, since joints had sufficient strength and metallurgical phases in the original wires were not greatly altered.

  14. Optical probing of exploding wires using schlieren and interferometric imaging.

    Science.gov (United States)

    Romanova, V. M.; Pikuz, S. A.; Shelkovenko, T. A.; Hu, Min; Sinars, D. B.; Kusse, B. R.; Dimant, Ya. S.; Greenly, J. B.; Hummer, D. A.

    1999-11-01

    Optical diagnostics using an Nd:YAG laser (l=532 nm) were used to probe exploding fine wires (7.5-20 mm initial diameter) driven by a sinusoidal 4.5/,kA current pulse (350 ns risetime). Phase transitions from vapor to plasma have been directly observed during the explosion process of various wire materials (Al, Au, etc.). Three simultaneous schlieren channels and 1--3 interferometry channels were used. For some experiments, the schlieren channels were made up of a bright-field iris, a dark-field knife edge, and a dark-field strip block. For other experiments, three bright-field images were made at 10 ns intervals. Interferometry was performed using a new astigmatism-free shearing interferometer based on a double-prism air wedge. The images were made with a 4 ns exposure time at 50--2000 ns after the start of the wire current. Simultaneous X-ray backlighting [1] of the wires enabled reliable interpretation of the optical images, and with a step wedge [2] was used to measure the ion density. Combining the ion density and electron density measurements allowed us to estimate the ionization state of the exploded wire. 1. T.A.Shelkovenko, S.A.Pikuz, A.R.Mingaleev, D.A.Hammer, Rev. Sci. Instrum., 70, 667 (1999). 2. S.A.Pikuz, T.A.Shelkovenko, A.R.Mingaleev, H.Neves, D.A.Hammer, Phys. Plasmas (in press).

  15. Scalable Nernst thermoelectric power using a coiled galfenol wire

    Directory of Open Access Journals (Sweden)

    Zihao Yang

    2017-09-01

    Full Text Available The Nernst thermopower usually is considered far too weak in most metals for waste heat recovery. However, its transverse orientation gives it an advantage over the Seebeck effect on non-flat surfaces. Here, we experimentally demonstrate the scalable generation of a Nernst voltage in an air-cooled metal wire coiled around a hot cylinder. In this geometry, a radial temperature gradient generates an azimuthal electric field in the coil. A Galfenol (Fe0.85Ga0.15 wire is wrapped around a cartridge heater, and the voltage drop across the wire is measured as a function of axial magnetic field. As expected, the Nernst voltage scales linearly with the length of the wire. Based on heat conduction and fluid dynamic equations, finite-element method is used to calculate the temperature gradient across the Galfenol wire and determine the Nernst coefficient. A giant Nernst coefficient of -2.6 μV/KT at room temperature is estimated, in agreement with measurements on bulk Galfenol. We expect that the giant Nernst effect in Galfenol arises from its magnetostriction, presumably through enhanced magnon-phonon coupling. Our results demonstrate the feasibility of a transverse thermoelectric generator capable of scalable output power from non-flat heat sources.

  16. Scalable Nernst thermoelectric power using a coiled galfenol wire

    Science.gov (United States)

    Yang, Zihao; Codecido, Emilio A.; Marquez, Jason; Zheng, Yuanhua; Heremans, Joseph P.; Myers, Roberto C.

    2017-09-01

    The Nernst thermopower usually is considered far too weak in most metals for waste heat recovery. However, its transverse orientation gives it an advantage over the Seebeck effect on non-flat surfaces. Here, we experimentally demonstrate the scalable generation of a Nernst voltage in an air-cooled metal wire coiled around a hot cylinder. In this geometry, a radial temperature gradient generates an azimuthal electric field in the coil. A Galfenol (Fe0.85Ga0.15) wire is wrapped around a cartridge heater, and the voltage drop across the wire is measured as a function of axial magnetic field. As expected, the Nernst voltage scales linearly with the length of the wire. Based on heat conduction and fluid dynamic equations, finite-element method is used to calculate the temperature gradient across the Galfenol wire and determine the Nernst coefficient. A giant Nernst coefficient of -2.6 μV/KT at room temperature is estimated, in agreement with measurements on bulk Galfenol. We expect that the giant Nernst effect in Galfenol arises from its magnetostriction, presumably through enhanced magnon-phonon coupling. Our results demonstrate the feasibility of a transverse thermoelectric generator capable of scalable output power from non-flat heat sources.

  17. Transparency in nanophotonic quantum wires

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Mahi R [Department of Physics and Astronomy, University of Western Ontario, London N6A 3K7 (Canada)

    2009-03-28

    We have studied the quantum optics of a photonic quantum nanowire doped with an ensemble of three-level nanoparticles. The wire is made from two photonic crystals A and B. Crystal A is embedded within crystal B and acts as a photonic nanowire. It is considered that the conduction band of crystal A lies below that of crystal B. As a result, photons are confined in crystal A and are reflected from crystal B. The bound states of the confined photons are calculated using the transfer matrix method. It is found that the number of bound states in the wire depends on the size of the wire and the energy difference between the conduction band extrema of crystals A and B. The absorption coefficient of the system has also been calculated using the Schroedinger equation method. It is considered that the nanoparticles interact with the photonic bound states. Numerical simulations show that when one of the resonance energies lies near the bound state, the system becomes transparent. However, when the resonance energy lies away from the bound state the crystal reverts to an absorbing state. Similarly, when the radius of the dielectric spheres is changed the location of the transparency peak is shifted. This means that the present system can be switched between two states by changing the size of the wire and the transition energy. These findings can be used to make new types of optical devices.

  18. Towards Unconventional Applications of Wire Bonding

    OpenAIRE

    Schröder, Stephan

    2018-01-01

    This thesis presents novel heterogeneous integration approaches of wire materials to fabricated and package MEMS devices by exploring unconventional applications of wire bonding technology. Wire bonding, traditionally endemic in the realm of device packaging to establish electrical die-to-package interconnections, is an attractive back-end technology, offering promising features, such as high throughput, flexibility and placement accuracy. Exploiting the advantages of state-of-the-art wire bo...

  19. Novel Wiring Technologies for Aerospace Applications

    Science.gov (United States)

    Gibson, Tracy L.; Parrish, Lewis M.

    2014-01-01

    Because wire failure in aerospace vehicles could be catastrophic, smart wiring capabilities have been critical for NASA. Through the years, researchers at Kennedy Space Center (KSC) have developed technologies, expertise, and research facilities to meet this need. In addition to aerospace applications, NASA has applied its knowledge of smart wiring, including self-healing materials, to serve the aviation industry. This webinar will discuss the development efforts of several wiring technologies at KSC and provide insight into both current and future research objectives.

  20. Electron transport in stretched monoatomic gold wires.

    Science.gov (United States)

    Grigoriev, A; Skorodumova, N V; Simak, S I; Wendin, G; Johansson, B; Ahuja, R

    2006-12-08

    The conductance of monoatomic gold wires containing 3-7 gold atoms has been obtained from ab initio calculations. The transmission is found to vary significantly depending on the wire stretching and the number of incorporated atoms. Such oscillations are determined by the electronic structure of the one-dimensional (1D) part of the wire between the contacts. Our results indicate that the conductivity of 1D wires can be suppressed without breaking the contact.

  1. Tissue-Viability Monitoring Using an Oxygen-Tension Sensor

    Science.gov (United States)

    Tanase, Dafina; Komen, Niels; Draaijer, Arie; Kleinrensink, Gert-Jan; Jeekel, Johannes; Lange, Johan F.; French, Paddy J.

    Many patients still die every year as a result of anastomotic leakage after surgery. An objective aid to monitor the anastomotic site pre- and postoperatively and detect leakage at an early stage is needed. We propose a miniature measurement system to detect adequate tissue oxygenation pre- and postoperatively (continuously for 7 days) on the colon. The complete sensor chip should include an oxygen-tension sensor (pO2), a carbon dioxide tension sensor (pCO2) and a temperature sensor. The work presented here focuses on the measurements done with the oxygen-tension and temperature sensors. In-vitro measurements have been initially performed to test the sensor system and in-vivo tests were carried out on the kidney and the intestines of male wistar rats. The results obtained so far have shown the suitability of this technique for clinical application, therefore sensor-system miniaturisation is presently underway.

  2. Measured and predicted root-mean-square errors in square and triangular antenna mesh facets

    Science.gov (United States)

    Fichter, W. B.

    1989-01-01

    Deflection shapes of square and equilateral triangular facets of two tricot-knit, gold plated molybdenum wire mesh antenna materials were measured and compared, on the basis of root mean square (rms) differences, with deflection shapes predicted by linear membrane theory, for several cases of biaxial mesh tension. The two mesh materials contained approximately 10 and 16 holes per linear inch, measured diagonally with respect to the course and wale directions. The deflection measurement system employed a non-contact eddy current proximity probe and an electromagnetic distance sensing probe in conjunction with a precision optical level. Despite experimental uncertainties, rms differences between measured and predicted deflection shapes suggest the following conclusions: that replacing flat antenna facets with facets conforming to parabolically curved structural members yields smaller rms surface error; that potential accuracy gains are greater for equilateral triangular facets than for square facets; and that linear membrane theory can be a useful tool in the design of tricot knit wire mesh antennas.

  3. Detection of a buried wire with two resistively loaded wire antennas

    NARCIS (Netherlands)

    Vossen, S.H.J.A.; Tijhuis, A.G.; Lepelaars, E.S.A.M.; Zwamborn, A.P.M.

    2002-01-01

    The use of two identical straight thin-wire antennas for the detection of a buried wire is analyzed with the aid of numerical calculations. The buried wire is located below an interface between two homogeneous half-spaces. The detection setup, which is formed by a transmitting and a receiving wire,

  4. One century of Kirschner wires and Kirschner wire insertion techniques : A historical review

    NARCIS (Netherlands)

    Franssen, Bas B. G. M.; Schuurman, Arnold H.; Van der Molen, Aebele Mink; Kon, Moshe

    A century ago, in 1909, Martin Kirschner (1879-942) introduced a smooth pin, presently known as the Kirschner wire (K-wire). The K-wire was initiallly used for skeletal traction and is now currently used for many different goals. The development of the K-wire and its insertion devices were mainly

  5. Actin cortex architecture regulates cell surface tension.

    Science.gov (United States)

    Chugh, Priyamvada; Clark, Andrew G; Smith, Matthew B; Cassani, Davide A D; Dierkes, Kai; Ragab, Anan; Roux, Philippe P; Charras, Guillaume; Salbreux, Guillaume; Paluch, Ewa K

    2017-06-01

    Animal cell shape is largely determined by the cortex, a thin actin network underlying the plasma membrane in which myosin-driven stresses generate contractile tension. Tension gradients result in local contractions and drive cell deformations. Previous cortical tension regulation studies have focused on myosin motors. Here, we show that cortical actin network architecture is equally important. First, we observe that actin cortex thickness and tension are inversely correlated during cell-cycle progression. We then show that the actin filament length regulators CFL1, CAPZB and DIAPH1 regulate mitotic cortex thickness and find that both increasing and decreasing thickness decreases tension in mitosis. This suggests that the mitotic cortex is poised close to a tension maximum. Finally, using a computational model, we identify a physical mechanism by which maximum tension is achieved at intermediate actin filament lengths. Our results indicate that actin network architecture, alongside myosin activity, is key to cell surface tension regulation.

  6. SURFACE TENSION TECHNIQUES FOR MOLTEN SALTS

    Science.gov (United States)

    Some 200 surface tension determinations were made on 107 single-salt melts using eight experimental techniques. From a consideration of the... surface tension range of applicability and temperature limitation for these techniques are briefly considered.

  7. A TOGgle for Tension at Kinetochores

    OpenAIRE

    Cheerambathur, Dhanya K.; Prevo, Bram; Desai, Arshad

    2016-01-01

    Differential stability of kinetochore-microtubule attachments at low versus high tension is critical for accurate chromosome segregation. Miller et al. find that a TOG domain microtubule-binding protein imparts intrinsic tension selectivity to kinetochore-microtubule attachments.

  8. Home and School Technology: Wired versus Wireless.

    Science.gov (United States)

    Van Horn, Royal

    2001-01-01

    Presents results of informal research on smart homes and appliances, structured home wiring, whole-house audio/video distribution, hybrid cable, and wireless networks. Computer network wiring is tricky to install unless all-in-one jacketed cable is used. Wireless phones help installers avoid pre-wiring problems in homes and schools. (MLH)

  9. Electrochemistry of surface wired cytochrome c and ...

    Indian Academy of Sciences (India)

    Pyrazine unit in the mixed self-assembly promotes the electron transfer in the redox reaction of surface wired Cyt-c. Cyt-c wired on the mixed self-assembly has been used for the amperometric sensing of superoxide. The enzymatically generated superoxide has been successfully detected using the Cyt-c wired electrode.

  10. 49 CFR 393.28 - Wiring systems.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Wiring systems. 393.28 Section 393.28 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY... NECESSARY FOR SAFE OPERATION Lamps, Reflective Devices, and Electrical Wiring § 393.28 Wiring systems...

  11. Customised 2G HTS wire for applications

    Science.gov (United States)

    Samoilenkov, S.; Molodyk, A.; Lee, S.; Petrykin, V.; Kalitka, V.; Martynova, I.; Makarevich, A.; Markelov, A.; Moyzykh, M.; Blednov, A.

    2016-02-01

    Reproducibility of superconducting properties and suitability for specific applications by means of customised finish are two important attributes required from commercial 2G HTS wire. This paper reviews the consistent performance of SuperOx production 2G HTS wire and describes two novel customisation options: surround polyimide varnish insulation and composite bulk materials assembled with 2G HTS wires soldered together.

  12. Line tension and reduction of apparent contact angle associated with electric double layers

    CERN Document Server

    Dörr, Aaron

    2014-01-01

    The line tension of an electrolyte wetting a non-polar substrate is computed analytically and numerically. The results show that, depending on the value of the apparent contact angle, positive or negative line tension values may be obtained. Furthermore, a significant difference between Young's contact angle and the apparent contact angle measured several Debye lengths remote from the three-phase contact line occurs. When applying the results to water wetting highly charged surfaces, line tension values of the same order of magnitude as found in recent experiments can be achieved. Therefore, the theory presented may contribute to the understanding of line tension measurements and points to the importance of the electrostatic line tension. Being strongly dependent on the interfacial charge density, electrostatic line tension is found to be tunable via the pH value of the involved electrolyte. As a practical consequence, the stability of nanoparticles adsorbed at fluid-fluid interfaces is predicted to be depend...

  13. An in-situ calibration technique for four-wire hot-wire probe in conjunction for atmospheric studies

    Science.gov (United States)

    Sadr, Reza; Singha, Arindam

    2011-11-01

    There is an increasing need to resolve the small-scales of atmospheric turbulence in order to estimate the higher order statistics of the turbulent flow. Sonic anemometers are commonly used in atmospheric research; however their application can only provide data with low special and temporal resolution. Hot-wire (HW) probes are still the best tool to obtain turbulent statistics with high temporal and spatial resolution. But HW probes are rarely used for atmospheric measurement due to the intricacy and logistical difficulties associated with the calibration and applications of the required probes for this flow field. In the present study, an in-situ method of calibration of a four-wire hot-wire anemometer is proposed, which bypasses the need for prior calibration. A proper data reduction algorithm has been developed to be used in conjunction with the four-wire probe. The proposed methodology enables one to use the hot-wire anemometer for atmospheric measurement to obtain three dimensional velocity information, at high spatial and temporal resolution, without the necessity of going through extensive calibration procedure. The feasibility of this method has been tested in laboratory and Monte Carlo simulation has been used to establish the stability and sensitivity of the data reduction algorithm.

  14. Patella fracture fixation with suture and wire: you reap what you sew.

    Science.gov (United States)

    Egol, Kenneth; Howard, Daniel; Monroy, Alexa; Crespo, Alexander; Tejwani, Nirmal; Davidovitch, Roy

    2014-01-01

    Operative fixation of displaced inferior pole patella fractures has now become the standard of care. This study aims to quantify clinical, radiographic and functional outcomes, as well as identify complications in a cohort of patients treated with non-absorbable braided suture fixation for inferior pole patellar fractures. These patients were then compared to a control group of patients treated for mid-pole fractures with K-wires or cannulated screws with tension band wiring. In this IRB approved study, we identified a cohort of patients who were diagnosed and treated surgically for a displaced patella fracture. Demographic, injury, and surgical information were recorded. All patients were treated with a standard surgical technique utilizing non-absorbable braided suture woven through the patellar tendon and placed through drill holes to achieve reduction and fracture fixation. All patients were treated with a similar post-operative protocol and followed up at standard intervals. Data were collected concurrently at follow up visits. For purpose of comparison, we identified a control cohort with middle third patella fractures treated with either k-wires or cannulated screws and tension band technique. Patients were followed by the treating surgeon at regular follow-up intervals. Outcomes included self-reported function and knee range of motion compared to the uninjured side. Forty-nine patients with 49 patella fractures identified retrospectively were treated over 9 years. This cohort consisted of 31 females (63.3%) and 18 males (36.7%) with an average age of 57.1 years (range 26-88 years). Patients had an average BMI of 26.48 (range 19-44.08). Thirteen patients with inferior pole fractures underwent suture fixation and 36 patients with mid-pole fractures underwent tension band fixation (K-wire or cannulated screws with tension band). In the suture cohort, one fracture failed open repair (7.6%), which was revised again with sutures and progressed to union. Of the 36

  15. Direct correlation between strengthening mechanisms and electrical noise in strained copper wires

    OpenAIRE

    Bellido, Natalia; Pautrat, Alain; Keller, Clement; Hug, Eric

    2011-01-01

    We have measured the resistance noise of copper metallic wires during a tensile stress. The time variation of the main resistance is continuous up to the wire breakdown, but its fluctuations reveal the intermittent and heterogeneous character of plastic flow. We show in particular direct correlations between strengthening mechanisms and noise spectra characteristics.

  16. X-ray power increase from symmetrized wire-array z-pinch implosions

    Energy Technology Data Exchange (ETDEWEB)

    Sanford, T.W.L.; Allshouse, G.O.; Marder, B.M. [and others

    1996-08-01

    A systematic experimental study of annular aluminum-wire z-pinches on the Saturn accelerator shows that, for the first time, the measured spatial characteristics and x-ray powers can approach those of two-dimensional, radiation-magneto-hydrodynamic simulations when large numbers of wires are used. Calculations show that the implosion begins to transition from that of individual plasma wires to that of a continuous plasma shell, when the circumferential gap between wires in the array is reduced below 1.4+1.3/-0.7 mm. This calculated gap coincides with the measured transition of 1.4 {+-}0.4 mm between the observed regimes of slow and rapid improvement in power output with decreasing gap. In the plasma shell regime, x-ray powers in excess of a factor of three over that generated in the plasma-wire region are measured.

  17. Effect of tendon tensioning: an in vitro study in porcine extensor tendons.

    Science.gov (United States)

    Figueroa, David; Calvo, Rafael; Vaisman, Alex; Meleán, Patricio; Figueroa, Francisco

    2010-06-01

    Graft tensioning is a controversial issue in anterior cruciate ligament reconstruction (ACLR) that has not achieved consensus between peers. The purpose of this study is to determine if after tensioning tendon length and resistance to maximal load changes. We performed an in vitro study with 50 porcine extensors tendons. The first group (P=25) was tensioned with 80 N (19.97 lb) for 10 min, using an ACL graft preparation board. The second group (C=25) was used as control and was not tensioned. The average initial (groups P and C) and post tensioning tendon length (group C) were measured; the average initial and post tensioning tendon diameter were measured as well. All samples were fixated in a tube-clamp system connected to a tension sensor. The samples were stressed with continuous and progressive tension until ultimate failure at maximum load (UFML) occurs. The initial mean length was: P before tensioning=13.4 mm+/-1.4 mm (range 10.5-16.5); P after tensioning=13.8 mm+/-1.4 mm (range 11.5-16.5); C=13 mm+/-1.35 mm (p=0.005). The mean diameter was: P=5.6 mm (4.5-6); C=5.5 mm (range 4.5-6) (p>0.05). The UFML was: P=189.7 N (114-336); C=229.9 N (143-365) (p=0.029). Tendon tensioning with 80 N for 10 min produced 3% average elongation. These could be beneficial in ACLR since tendon tensioning decreases elongation of the graft after fixation. Regardless, tendon tensioning is not innocuous since it diminishes their resistance when continuously stressed until complete failure occurs.

  18. Intraoperative Development of Tension Pneumocephalus in a ...

    African Journals Online (AJOL)

    Included is a literature review of studies discussing the role of N2O in the development of tension pneumocephalus. N2O is associated with tension pneumocephalus especially in the setting of preexisting pneumocephalus. Tension pneumocephalus can manifest as Cushing response and immediate decompression is ...

  19. AC losses in Bi2212 ROSAT wires exposed to an AC magnetic field (1); Bi2212 ROSAT senzai no koryu sonshitsu (1)

    Energy Technology Data Exchange (ETDEWEB)

    Matsumura, K.; Fukuda, Y.; Kajikawa, K.; Iwakuma, M.; Funaki, K. [Kyushu Univ., Fukuoka (Japan); Okada, M. [Hitachi Ltd., Tokyo (Japan)

    1999-11-10

    Bismuth system superconducting wire rod developed until now has been limited tapeline physical property the. However, the ROSAT wire rod in which tape wire rod had rotational symmetry of 3 times in the cross section of the round line recently was developed. The critical current density which is almost equivalent to tape wire rod in 4.2K and 28T by the homogenization of cross-sectional shape has been realized this ROSAT wire rod. This time, the ac loss in outside fluctuation magnetic field of superscription ROSAT wire rod was measured, and it was compared with the theoretical value, which deduced the ideal polycore line by assuming. (NEDO)

  20. The Plastic Tension Field Method

    DEFF Research Database (Denmark)

    Hansen, Thomas

    2005-01-01

    . The emphasis is attached to the presentation of a design method based on the diagonal tension field theory. Also, how to determine the load-carrying capacity of a given steel plate girder with transverse web stiffeners, is briefly presented. The load-carrying capacity may be predicted by applying both......This paper describes a calculation method for steel plate girders with transverse web stiffeners subjected to shear. It may be used for predicting the failure load or, as a design method, to determine the optimal amount of internal web stiffeners. The new method is called the plastic tension field...... method. The method is based on the theory of plasticity and is analogous to the so-called diagonal compression field method developed for reinforced concrete beams with transverse stirrups, which is adopted in the common European concrete code (Eurocode 2). Many other theories have been developed...